37,905 results on '"robust control"'
Search Results
2. Long-Horizon Robust Direct Model Predictive Control for Medium-Voltage Induction Motor Drives With Reduced Computational Complexity
- Author
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Ludovico Ortombina, Petros Karamanakos, Andrei Tregubov, Tampere University, and Electrical Engineering
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direct control ,model predictive control (MPC) ,213 Electronic, automation and communications engineering, electronics ,Stators ,Computational modeling ,Industrial and Manufacturing Engineering ,Computational complexity ,Predictive models ,Control and Systems Engineering ,medium-voltage (MV) drives ,Rotors ,AC drives ,hardware-in-the-loop (HIL) simulations ,Electrical and Electronic Engineering ,Estimation ,Real-time systems ,robust control - Abstract
This paper proposes a long-horizon direct model predictive control (MPC) with reference tracking for medium-voltage (MV) drives that achieves favorable steady-state and transient behavior. However, as MPC is a model-based method, it is susceptible to parameter mismatches and variations of the machine. Moreover, even though a long prediction horizon significantly improves the steady-state behavior of the drive, it significantly increases the computational complexity of the direct MPC problem, rendering its real-time implementation a challenging—if not impossible—task. Motivated by these shortcomings of long-horizon direct MPC, this paper also aims to address them by enhancing the robustness of the developed control strategy, while keeping its computational complexity modest. To achieve the former, a prediction model suitable for MV drive systems is adopted that facilitates the effective estimation of the total leakage inductance of the machine. For the latter, the objective function of the MPC problem is formulated such that, even though the drive behavior is computed over a long prediction interval, only a few changes in the candidate switch positions are considered. The effectiveness of the proposed modeling, control, and estimation approaches is validated with hardware-in-the-loop (HIL) tests for an MV drive consisting of a three-level neutral point clamped (NPC) inverter and an induction machine (IM). acceptedVersion
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- 2023
3. Fault Estimation and Control for Unknown Discrete-Time Systems Based on Data-Driven Parameterization Approach
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Chao Deng, He Liu, Xiao-Jian Li, and Choon Ki Ahn
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Computer science ,Parameterized complexity ,Fault (power engineering) ,Computer Science Applications ,Slack variable ,Data-driven ,Human-Computer Interaction ,Discrete time and continuous time ,Control and Systems Engineering ,Control theory ,State (computer science) ,Electrical and Electronic Engineering ,Robust control ,Software ,Information Systems - Abstract
This study investigates the problem of fault estimation and control for unknown discrete-time systems. Such a problem was first formulated as an multiobjective optimization problem. Then, a data-driven parameterization controller design method was proposed to optimize both fault estimation and robust control performances. In terms of the single-objection control problem, necessary and sufficient conditions for designing the suboptimal controller were presented, and the performance index optimized by the developed data-driven method was shown to be consistent with that of the model-based method. In addition, by introducing additional slack variables into the controller design conditions, the conservatism of solving the multiobjective optimization problem was reduced. Furthermore, contrary to the existing data-driven controller design methods, the initial stable controller was not required, and the controller gain was directly parameterized by the collected state and input data in this work. Finally, the effectiveness and advantages of the proposed method are shown in the simulation results.
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- 2023
4. Reconfiguration of flow-based networks with back-up components using robust economic MPC
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Carlos Trapiello, Vicenç Puig, Gabriela Cembrano, Universitat Politècnica de Catalunya. Departament d'Enginyeria de Sistemes, Automàtica i Informàtica Industrial, Institut de Robòtica i Informàtica Industrial, and Universitat Politècnica de Catalunya. SAC - Sistemes Avançats de Control
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System reconfiguration ,Informàtica::Automàtica i control [Àrees temàtiques de la UPC] ,Control and Systems Engineering ,Modeling and Simulation ,Robust control ,Control de robustesa ,Back-up components ,Flow-based networks ,Industrial and Manufacturing Engineering ,Computer Science Applications - Abstract
This paper addresses the post-fault selection of an actuators configuration for flow-based networks with back-up components. The proposed reconfiguration methodology consists of an offline and an online phase. On the one hand, an offline analysis looks for the minimal configurations for which the economic cost of the (best) steady-state trajectory that can be achieved using a robust model predictive control (MPC) policy is admissible. On the other hand, at fault detection time, an online search for the best actuators configuration to cope with the transient induced by the fault is conducted in the superset of each minimal configuration calculated offline. With this strategy, the final new configuration is computed by sequentially solving a set of mixed-integer programs whose constraints are derived from single-layer robust MPC schemes coupled with local controllers designed for the a priori minimal configurations identified offline. A portion of a water transport network is used to show the performance the proposed solution.
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- 2023
5. Resilient Control Algorithm for Wind-Hydro Based Distributed Generation System with Grid Synchronization Capability
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Rohini Sharma and Bhim Singh
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business.industry ,Computer science ,AC power ,Industrial and Manufacturing Engineering ,Synchronization (alternating current) ,Frequency-locked loop ,Control theory ,Control and Systems Engineering ,Distributed generation ,Voltage source ,Voltage regulation ,Microgrid ,Robust control ,Electrical and Electronic Engineering ,business - Abstract
Microgrid is a key to an efficient and resilient power grid operation. Thus in this paper, a robust control scheme is implemented namely modified frequency locked loop (MFLL), proficient in eliminating the voltage and current fluctuations because of phase/frequency variation. Therefore, enhancing the consistency of the supply across nonlinear load through a smooth transition from utility-interactive to islanded mode. It also achieves accelerated convergence and reduced steady-state error. MFLL is an easy control technique, with only one interfacing voltage source converter, which delivers a stable supply to critical loads during different operating modes. The implemented system has the main advantage of the capability of power-sharing between distributed generations (DGs) systems while regulating the voltage at the DC link. It also provides power quality improvement through harmonics suppression; voltage regulation during contingencies like unbalance in load and compensation in reactive power at the common coupling point following the prerequisite of the system. The performance through the implemented control algorithm is brought about in MATLAB 15b/Simulink platform. The performances of results are compared with already reported control strategies. Thus, simulated results comparison with existing work presents the competence of the implemented control strategy under dynamic conditions.
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- 2023
6. Linear Fractional Transformation Modeling of Multibody Dynamics Around Parameter-Dependent Equilibrium
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Ervan Kassarian, Francesco Sanfedino, Daniel Alazard, Charles-Antoine Chevrier, Johan Montel, Centre National d'Études Spatiales - CNES (FRANCE), and Institut Supérieur de l'Aéronautique et de l'Espace - ISAE-SUPAERO (FRANCE)
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Autre ,Linear fractional transformation~(LFT) modeling ,Control and Systems Engineering ,Linear parameter-varying (LPV) system ,FOS: Electrical engineering, electronic engineering, information engineering ,Robust control ,Multibody dynamics ,Systems and Control (eess.SY) ,Electrical and Electronic Engineering ,Electrical Engineering and Systems Science - Systems and Control - Abstract
This brief proposes a new linear fractional transformation (LFT) modeling approach for uncertain linear parameter-varying (LPV) multibody systems with parameter-dependent equilibrium. Traditional multibody approaches, which consist of building the nonlinear model of the whole structure and linearizing it around equilibrium after a numerical trimming, do not allow to isolate parametric variations with the LFT form. Although additional techniques, such as polynomial fitting or symbolic linearization, can provide an LFT model, they may be time-consuming or miss worst case configurations. The proposed approach relies on the trimming and linearization of the equations at the substructure level, before assembly of the multibody structure, which allows to only perform operations that preserve the LFT form throughout the linearization process. Since the physical origin of the parameters is retained, the linearized LFT-LPV model of the structure exactly covers all the plants, in a single parametric model, without introducing conservatism or fitting errors. An application to the LFT-LPV modeling of a robotic arm is proposed; in its nominal configuration, the model obtained with the proposed approach matches the model provided by the software Simscape Multibody, but it is enhanced with parametric variations with the LFT form; a robust LPV synthesis is performed using MATLAB robust control toolbox to illustrate the capacity of the proposed approach for control design.
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- 2023
7. Data‐driven mixed‐sensitivity control with automated weighting functions selection
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Nicholas Valceschini, Mirko Mazzoleni, Simone Formentin, and Fabio Previdi
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kernel-based system identification ,Settore ING-INF/04 - Automatica ,Control and Systems Engineering ,Mechanical Engineering ,General Chemical Engineering ,Biomedical Engineering ,Aerospace Engineering ,Electrical and Electronic Engineering ,mixed sensitivity loop-shaping ,data-driven robust control ,robust control ,Industrial and Manufacturing Engineering - Published
- 2023
8. Stochastic Model Predictive Control With a Safety Guarantee for Automated Driving
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Tim Brüdigam, Marion Leibold, Dirk Wollherr, and Michael Olbrich
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Control and Optimization ,Computer science ,Probabilistic logic ,Stochastic model predictive control ,Finite horizon ,Motion (physics) ,ddc ,Artificial Intelligence ,Control theory ,Backup ,Automotive Engineering ,Trajectory ,Motion planning ,Robust control - Abstract
Automated vehicles require efficient and safe planning to maneuver in uncertain environments. Largely this uncertainty is caused by other traffic participants, e.g., surrounding vehicles. Future motion of surrounding vehicles is often difficult to predict. Whereas robust control approaches achieve safe, yet conservative motion planning for automated vehicles, Stochastic Model Predictive Control (SMPC) provides efficient planning in the presence of uncertainty. Probabilistic constraints are applied to ensure that the maximal risk remains below a predefined level. However, safety cannot be ensured as probabilistic constraints may be violated, which is not acceptable for automated vehicles. Here, we propose an efficient trajectory planning framework with safety guarantees for automated vehicles. SMPC is applied to obtain efficient vehicle trajectories for a finite horizon. Based on the first optimized SMPC input, a guaranteed safe backup trajectory is planned using reachable sets. This backup is used to overwrite the SMPC input if necessary for safety. Recursive feasibility of the safe SMPC algorithm is proved. Highway simulations show the effectiveness of the proposed method regarding performance and safety.
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- 2023
9. Robust and Optimal Control Designed for Autonomous Surface Vessel Prototypes
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Murillo Ferreira Dos Santos, Accacio Ferreira Dos Santos Neto, Leonardo De Mello Honorio, Mathaus Ferreira Da Silva, and Paolo Mercorelli
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Control systems ,General Computer Science ,Optimal Control ,Robust control ,Uncertainty ,General Engineering ,Vehicle dynamics ,Tuning ,Topology ,Autonomous Surface Vehicles ,Successive Loop Closure ,Engineering ,Robust Control Design ,pid Controller ,General Materials Science ,Electrical and Electronic Engineering - Abstract
It is well known that activities in running water or wind and waves expose the Autonomous Surface Vessels (ASVs) to considerable challenges. Under these conditions, it is essential to develop a robust control system that can meet the requirements and ensure the safe and accurate execution of missions. In this context, this paper presents a new topology for controller design based on a combination of the Successive Loop Closure (SLC) method and optimal control. This topology enables the design of robust autopilots based on the Proportional-Integral-Derivative (PID) controller. The controllers are tuned from the solution of the optimal control problem, which aims to minimize the effects of model uncertainties. To verify the effectiveness of the proposed controller, a numerical case study of a natural ASV with 3 Degree of Freedom (DoF) is investigated. The results show that the methodology enabled the tuning of a PID controller capable of dealing with different parametric uncertainties, demonstrating robustness and applicability for different prototype scenarios.
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- 2023
10. Set-based fast gradient projection algorithm for model predictive control of grid-tied power converters
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Renato Babojelić, Bruno Vilić Belina, Šandor Ileš, and Jadranko Matuško
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Power converters ,model predictive control ,robust control ,fast gradient projection method ,field programmable gate array ,General Computer Science ,Control and Systems Engineering - Abstract
Model Predictive Control (MPC) has attracted much attention and is widely used in power electronics. However, implementing the MPC algorithm is still a difficult task due to the fast dynamics of power converters and strict time constraints. In this paper, a computationally efficient MPC algorithm for grid-tied power converters based on the fast gradient projection method and invariant set theory is proposed. The algorithm is implemented and tested through hardware-in-the-loop simulations using Texas Instruments digital signal processors and Xilinx Field Programmable Gate Arrays platforms.
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- 2022
11. A Robust Control for Solar and SyRG Based Hydro Generation Microgrid With Grid Synchronization
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Rohini Sharma and Bhim Singh
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0209 industrial biotechnology ,Computer science ,020208 electrical & electronic engineering ,Photovoltaic system ,02 engineering and technology ,Maximum power point tracking ,Industrial and Manufacturing Engineering ,Synchronization (alternating current) ,020901 industrial engineering & automation ,Frequency-locked loop ,Control theory ,Control and Systems Engineering ,Control system ,0202 electrical engineering, electronic engineering, information engineering ,Microgrid ,Robust control ,Electrical and Electronic Engineering ,Inner loop - Abstract
The control of a microgrid is quite challenging thus this work implements a robust and fast control technique based on circular limited cycle oscillator frequency locked loop with inner loop filter (CLO-FLL-WIF) for switching operation between an islanded and the grid-connected modes. This microgrid combing solar PV (Photovoltaic) generation, SyRG (Synchronous Reluctance Generator) for pico-hydro generation, and the battery, which works in both standalone and grid-connected modes while feeding local loads uninterruptedly. The output power conversion of a PV array is influenced by irradiation of solar PV array and has low efficiency, therefore, a MPPT (Maximum Power Point Tracking) namely an INC (Incremental Conductance) method is used. In the implemented system, the interfaced power converter is gated in the grid-connected mode and islanded mode using same enhanced second order generalized integrator with a modified frequency locked loop (ESOGI-MFLL) control method. The comparative results validate that the response of ESOGI-MFLL in comparison to the existing control algorithm, is faster under load and generation perturbations. The implemented control techniques are used for fundamental extraction of load component of voltage and current for assessment of reference currents with their respective phases of synchronization while maintaining the required IEEE power quality standard-519. Simulated results of a microgrid for grid-tied PV-BES-SyRG are obtained in MATLAB/Simulink platform to demonstrate its performance.
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- 2022
12. Centralized/decentralized indirect robust adaptive control for spacecraft attitude and robotics
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Aureliano Rivolta and Paolo Lunghi
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Control and Systems Engineering ,Mechanical Engineering ,General Chemical Engineering ,adaptive control ,on orbit servicing ,robotics ,robust control ,Biomedical Engineering ,Aerospace Engineering ,Electrical and Electronic Engineering ,Industrial and Manufacturing Engineering - Published
- 2022
13. Modeling and control of an invasive mechanical ventilation system using the active disturbances rejection control structure
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David I. Rosas Almeida, Armando Cantú Cárdenas, Iván Olaf Hernández Fuentes, Rosa Citlalli Anguiano Cota, Laura Ocotlán Orea León, David Rafael Cañez Martínez, and Angélica María Martínez Contreras
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Ventilators, Mechanical ,Critical Care ,Applied Mathematics ,Robust control ,COVID-19 ,Mechanical ventilator ,Models, Theoretical ,Identification of disturbances ,Respiration, Artificial ,Computer Science Applications ,Control and Systems Engineering ,Humans ,Electrical and Electronic Engineering ,Instrumentation ,Research Article - Abstract
We propose a mandatory invasive mechanical ventilator prototype for severe COVID-19 patients with volume and pressure control operation modes. This system comprises basic pneumatic elements and sensors. Its performance is similar to commercial equipment, and it presents robustness to external disturbances and parametric uncertainties. To develop a control strategy, we propose a mathematical model with a variable structure that incorporates the dead zone phenomenon of the proportional valve, and considers external disturbances and parametric uncertainties. Based on this model, we propose a global control strategy that is based on pressure and flow regulation controllers, which use the active disturbances rejection control structure (ADRC). In this strategy, we propose robust state observers to estimate disturbances and the signals necessary for implementing the controllers. We illustrate the performance of the prototype and the control strategy through numerical simulations and experiments. We also compare its performance with PID controllers. These results corroborate its effectiveness and the possibility of its application in invasive mechanical ventilators with a simple structure, which can significantly help critical care of COVID-19 inpatients.
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- 2022
14. H∞ Codesign for Uncertain Nonlinear Control Systems Based on Policy Iteration Method
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Bin Xu, Quan-Yong Fan, and Dongsheng Wang
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0209 industrial biotechnology ,Mathematical optimization ,Optimization problem ,Iterative method ,Computer science ,Explained sum of squares ,02 engineering and technology ,Nonlinear control ,Computer Science Applications ,Human-Computer Interaction ,020901 industrial engineering & automation ,Control and Systems Engineering ,Control theory ,Convergence (routing) ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Electrical and Electronic Engineering ,Robust control ,Performance improvement ,Software ,Information Systems - Abstract
In this article, the problem of H∞ codesign for nonlinear control systems with unmatched uncertainties and adjustable parameters is investigated. The main purpose is to solve the adjustable parameters and H∞ controller simultaneously so that better robust control performance can be achieved. By introducing a bounded function and defining a special cost function, the problem of solving the Hamilton-Jacobi-Isaacs equation is transformed into an optimization problem with nonlinear inequality constraints. Based on the sum of squares technique, a novel policy iteration algorithm is proposed to solve the problem of the H∞ codesign. Moreover, one modified algorithm for optimizing the robust performance index is given. The convergence and the performance improvement of new iteration policy algorithms are proved. Simulation results are presented to demonstrate the effectiveness of the proposed algorithms.
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- 2022
15. Robust Navigation Control of a Microrobot With Hysteresis Compensation
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Dingran Dong, Dong Sun, Liushuai Zheng, Yuanjun Jia, and Yong Wang
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Computer Science::Robotics ,Nonlinear system ,Control and Systems Engineering ,Control theory ,Computer science ,Electromagnetic coil ,Genetic algorithm ,Trajectory ,Electrical and Electronic Engineering ,Robust control ,Sliding mode control ,Compensation (engineering) - Abstract
Navigation control of microrobots in vivo has great potential in precision medicine and has attracted considerable attention in recent years. The control performance of the existing methods is considerably affected by hysteresis nonlinearity. This article presents a robust control method that can overcome hysteresis influence in navigating a microrobot actuated by an electromagnetic coil system. A motion planner that combines the breadth-first search (BFS) method and genetic algorithm (GA) is used to plan a reliable and flexible trajectory for the microrobot navigation. To compensate for hysteresis nonlinearity existing in the system, the Prandtl-Ishlinskii (PI) model is introduced. A robust controller that integrates adaptive sliding mode control (ASMC) and nonlinear disturbance observer is designed to guarantee the stability and accuracy of the microrobot in motion. Experiments have been performed to demonstrate the effectiveness of the proposed approach. The success of this research will advance the microrobot navigation for in vivo applications.
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- 2022
16. Input Constraint Sets for Robust Regulation of Linear Systems
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Mario Zanon, Sampath Kumar Mulagaleti, and Alberto Bemporad
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Constraint (information theory) ,Set (abstract data type) ,Mathematical optimization ,Model predictive control ,Control and Systems Engineering ,Computer science ,Control theory ,Linear system ,State (functional analysis) ,Electrical and Electronic Engineering ,Robust control ,Focus (optics) ,Computer Science Applications - Abstract
In robust control under state constraints the set of admissible inputs is usually considered as given, under the assumption that the actuators have been already designed. However, if the input set is too small any controller will fail in stabilizing the closed-loop system while satisfying all prescribed constraints for some initial states of interest, or vice versa the chosen actuators may be over-sized. To handle this issue, in this paper we address the problem of computing the smallest input constraint set such that the closed-loop system is stabilizable from a prescribed set of initial states while respecting all constraints. We focus our attention on linear systems with additive disturbances, and develop the algorithm based on recursive feasibility of robust model predictive control. We demonstrate the results using numerical examples, in which we consider different metrics for the input constraint set selection.
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- 2022
17. Parameter-Variation-Tolerant Robust Current Sensorless Control of a Single-Phase Boost PFC
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Ayan Mallik, Ashwin Chandwani, and Saikat Dey
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Reduction (complexity) ,Control theory ,Computer science ,Robustness (computer science) ,Reliability (computer networking) ,Response time ,Current sensor ,General Medicine ,Sensitivity (control systems) ,Robust control - Abstract
With the objective to eliminate the input current sensor in a totem-pole boost power factor corrector (TPFC) for its low-cost design, a novel discretized sampling-based robust control scheme is proposed in this work. The proposed control methodology proves to be beneficial due to its ease of implementation and its ability to support high frequency operation, while being able to eliminate one sensor, and thus enhancing reliability and cost-effectiveness. In addition to that, detailed closed loop stability analysis is carried out for the controller in discrete domain to ascertain brisk dynamic operation when subjected to sudden load fluctuations. To establish the robustness of the proposed control scheme, a detailed sensitivity analysis of the closed loop performance metrics with respect to undesired changes and inherent uncertainty in system parameters is presented in this paper. A comparison with the state-of-the-art (SOA) methods is provided, and conclusive results in terms of better dynamic performance are also established. To verify and elaborate on the specifics of the proposed scheme, a detailed simulation study is conducted, and the results show 25% reduction in response time as compared to SOA approaches. A 500W boost PFC prototype is developed and tested with the proposed control scheme to evaluate the steady state and dynamic performance.
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- 2022
18. Clutch Mechanical Leg Neural Network Adaptive Robust Control of Shift Process for Driving Robot With Clutch Transmission Torque Compensation
- Author
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Jiang Junhao, Liangmo Wang, Weigong Zhang, and Gang Chen
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Artificial neural network ,Transmission (telecommunications) ,Control and Systems Engineering ,Control theory ,Computer science ,Process (computing) ,Robot ,Torque ,Clutch ,Electrical and Electronic Engineering ,Robust control ,Compensation (engineering) - Published
- 2022
19. Adaptive Robust Control for Pointing Tracking of Marching Turret-Barrel Systems: Coupling, Nonlinearity and Uncertainty
- Author
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Qinqin Sun, Xiuye Wang, Guolai Yang, Ye-Hwa Chen, and Fai Ma
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Control systems ,pointing tracking ,Artificial Intelligence and Image Processing ,Intelligent ground combat platform ,Mechanical Engineering ,Logistics & Transportation ,Uncertainty ,Robust control ,Adaptive systems ,Civil Engineering ,Computer Science Applications ,turret-barrel system ,Torque ,Transportation and Freight Services ,Automotive Engineering ,Couplings ,adaptive robust control ,Nonlinear dynamical systems ,intelligent control - Abstract
Pointing tracking control of marching turret-barrel system is one of the important topics in exploration of intelligent ground combat platform. This paper focuses on an adaptive robust control scheme for pointing tracking of marching turret-barrel system driven by a motor and an electric cylinder. Three types of possibly fast time-varying but bounded uncertainty are considered: system modeling error, external disturbance and road excitation. The uncertainty bounds are not necessary to be known. First, the pointing tracking system is constructed as a coupled, nonlinear and uncertain dynamical system with two interconnected (horizontal and vertical) subsystems. Second, a tracking error e is defined as a gauge of control objective, and then the dynamical equation of the pointing tracking system is built in state-space form. Third, for uncertainty control, a comprehensive uncertainty bound α is derived to measure the most conservative influence of the uncertainty, and then an adaptive law is proposed to evaluate it in real time. Finally, for pointing tracking control, an adaptive robust control is proposed to render the pointing tracking system to be practically stable; thereout, the objective of pointing tracking is achieved. This work should be among the first ever endeavours to cast all the coupling, nonlinearity and bound-unknown uncertainty into the pointing tracking framework of marching turret-barrel system.
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- 2022
20. Automated Ground Vehicle Path-Following: A Robust Energy-to-Peak Control Approach
- Author
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Xingyu Zhou, Zejiang Wang, and Junmin Wang
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Robustification ,Control theory ,Computer science ,Robustness (computer science) ,Mechanical Engineering ,Attenuation ,Automotive Engineering ,Robust control ,Tracking (particle physics) ,Upper and lower bounds ,Energy (signal processing) ,Computer Science Applications - Abstract
Due to the simultaneous existence of model uncertainties and external disturbances, designing automated ground vehicle path-following controllers is recognized as a challenging task. The $H_{∞}$ robust control methodology, as one of the accomplished strategies for controller robustification, has been commonly adopted by researchers to address the vehicle path-tracking problems. Nevertheless, despite its advantages, the $H_{∞}$ controller is only capable of limiting the total ``energy'' of the tracking errors. On the other hand, from a safety standpoint, constraining the ``peak'' of the tracking errors may carry an equal or more importance. To establish a guaranteed upper bound on the path-tracking errors, this paper proposes a novel methodology to synthesis the ground vehicle path-following controller in light of the energy-to-peak robust control theory. Additionally, to address the time-varying uncertainties presented in the tire dynamics, robust stabilization constraints based upon the small-gain theorem are also formulated into the overall controller design problem. Comparative study regarding the disturbance rejection performance between the proposed controller and the conventional $H_{∞}$ approach is conducted via CarSim-Simulink joint simulations. Furthermore, the robustness and disturbance attenuation ability of the energy-to-peak path-tracking controller is experimentally verified on a scaled car.
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- 2022
21. Stackelberg-Game-Oriented Optimal Control for Bounded Constrained Mechanical Systems: A Fuzzy Evidence-Theoretic Approach
- Author
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Zhijun Li, Yunjun Zheng, Han Zhao, Chunsheng He, and Jinchuan Zheng
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Mathematical optimization ,Optimization problem ,Computer science ,Applied Mathematics ,Optimal control ,Fuzzy logic ,Constraint (information theory) ,Computational Theory and Mathematics ,Artificial Intelligence ,Control and Systems Engineering ,Bounded function ,Stackelberg competition ,Uniform boundedness ,Robust control - Abstract
This paper proposes a novel Stackelberg game-oriented optimal control approach to address the bounded constraint-following control problem for uncertain mechanical systems. First, the uncertainties (possibly fast time-varying) in the system are assumed to be bounded with an unknown boundary which lies in a specified fuzzy evidence number. In practical engineering, bounded system performance is always demanded, such as the inequality constraint. A diffeomorphism transformation approach is proposed to transform the constrained system into a restructured one satisfying the bounded constraint. Second, we propose an adaptive robust control oriented by the constraint-following control to render the restructured system to follow the specified constraints accurately with deterministic performance (guaranteeing uniform boundedness and uniform ultimate boundedness). The self-adjusting adaptive law (leakage-type) can compensate for the uncertainties and avoid overcompensation. Third, a Stackelberg game-oriented optimization approach is proposed to obtain the optimal control parameters based on the fuzzy evidence theory. In the optimization approach, the two control parameters, are considered as two players with respective cost functions related to system performance and control cost. Furthermore, the optimization problem is solved by obtaining the Stackelberg strategy, which is proved to exist in analytic form. Ultimately, the permanent magnet synchronous linear motor system simulation is presented to show the design process and the excellent performance of the proposed optimal control scheme.
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- 2022
22. Geometric-based prescribed performance control for unmanned aerial manipulator system under model uncertainties and external disturbances
- Author
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Weiwei Zhan, Zhiqiang Miao, Yaonan Wang, Chen Yanjie, He Bingwei, and Hui Zhang
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Lyapunov stability ,Adaptive control ,Computer science ,Underactuation ,Applied Mathematics ,Thrust ,Computer Science Applications ,Control and Systems Engineering ,Control theory ,Drag ,Trajectory ,Transient (oscillation) ,Electrical and Electronic Engineering ,Robust control ,Instrumentation - Abstract
In this paper, a robust control strategy with a cascade structure is designed for the underactuated unmanned aerial manipulator (UAM) to perform favorable trajectory tracking, in the presence of model uncertainties and time-varying external disturbances (e.g. wind drag). In the position loop, a geometric distance is adopted as the criterion for the thrust design. Besides, both the model uncertainties and external disturbances are compensated by employing a robust term. In the attitude loop, the prescribed performance guarantees are enforced in the controller design to standardize transient performance on attitude errors. In particular, just relying on the necessary feedback states, an auxiliary system, the adaptive control technique, and the disturbance observer are respectively designed to estimate the model uncertainties and external disturbances. Through the Lyapunov stability theory analysis, the proposed approach based on a geometric distance can effectively track the desired trajectory. The results of the comparative simulations study demonstrate the effectiveness and advantages of the proposed approach.
- Published
- 2022
23. Singularity-Free Continuous Adaptive Control of Uncertain Underactuated Surface Vessels With Prescribed Performance
- Author
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Jin-Xi Zhang and Tianyou Chai
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Adaptive control ,Computer science ,Underactuation ,Action (physics) ,Computer Science Applications ,Human-Computer Interaction ,Azimuth ,Tracking error ,Singularity ,Control and Systems Engineering ,Control theory ,Trajectory ,Electrical and Electronic Engineering ,Robust control ,Software - Abstract
This article is dealt with the problem of trajectory tracking with prescribed performance for a family of underactuated surface vessels (USVs) under model uncertainties and disturbances. The prescribed performance means that the USV tracks a given trajectory with the arbitrarily predefined speed of response and accuracy. The existing prescribed performance control (PPC) solutions and the traditional robust control approaches for USVs may have the singularity issue or cause a discontinuous control signal. Thereby, a new-type adaptive PPC strategy is put forward in this article. The adaptive technique is devoted to tackling model imperfections as usual, whereas the constraint-handling technique is adopted in a novel way. Herein, we first construct an auxiliary variable instead of using the approach angle or azimuth angle. Then, we impose constraints on the position error, not the tracking error, and the auxiliary variable, simultaneously. In this way, the predefined performance is achieved by moreover a singularity-free continuous control action. These theoretical findings are illustrated via a comparative simulation study.
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- 2022
24. Controller Design for Affine Nonlinear System Based on Constructing Optimization T–S Fuzzy Model and Disturbance Reconstruction
- Author
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Yuhang Fu and Fanglai Zhu
- Subjects
Affine nonlinear system ,Disturbance (geology) ,Computational Theory and Mathematics ,Observer (quantum physics) ,Artificial Intelligence ,Control and Systems Engineering ,Control theory ,Computer science ,Applied Mathematics ,Fuzzy model ,Interval (mathematics) ,Robust control ,Compensation (engineering) - Abstract
Affine nonlinear systems are special kinds of non-linear systems, and they can represent many practical systems. Dealing with affine nonlinear system based on T-S fuzzy model has drawn much attention in literature recently. In this paper, a robust control method is proposed for affine nonlinear system with disturbance based on T-S fuzzy model. First, an optimization T-S fuzzy model is constructed focusing on optimizing the parameters of the weight functions by using differential evolution algorithm (DEA). Second, in order to reconstruct the disturbance, an interval observer is designed for the affine nonlinear system, and then a novelty disturbance reconstruction method based on the interval observer is developed. The disturbance reconstruction value can asymptotically approach the actual disturbance value, and furthermore, it decouples the control input. Third, by taking the optimization T-S fuzzy model as design model and by introducing the reconstruction of disturbance into controller, a feedback robust controller with disturbance compensation is designed to stabilize the affine nonlinear system. Finally, a simulation example of the crane model is given and some comparisons are provided to verify the effectiveness and show the advantages of the proposed method.
- Published
- 2022
25. Automated nested co-design framework for structural/control dynamics in flexible space systems
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Paolo Gasbarri, Federica Angeletti, and Paolo Iannelli
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space structures ,attitude control ,co-design ,robust control ,Aerospace Engineering - Published
- 2022
26. Modelling and indirect field‐oriented control for pole phase modulation induction motor drives
- Author
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Atif Iqbal, B. Prathap Reddy, Syed Rahman, and Mohammad Meraj
- Subjects
TK ,Vector control (Electric machinery) ,Induction motor drive ,Robust control ,Electric drives ,Steady-state operation ,Modulation techniques ,Dynamic models ,Indirect field oriented control ,Induction motors ,Phase modulation ,Phase combinations ,Dynamics models ,Linear transformations ,Voltage control ,Modeling equations ,Matrix converters ,Multiphase machines ,Vehicle applications ,Multiphase induction motors ,Poles ,Electrical and Electronic Engineering ,Electric traction - Abstract
In the recent days, for the traction and electric vehicle (EV) applications, multiphase machines with pole phase modulation (PPM) technique have been proposed. The smoother operation during pole changeovers as well as steady-state operations is a significant constraint while adopting the PPM-based multiphase induction motor (PPMIM) drives for EV and traction applications. So, in this paper, the PPMIM dynamic model and associated vector control are proposed for attaining a smoother operation of the machine. The machine modelling equations and transformation matrices are implemented in an arbitrary reference frame by considering the different pole phase combinations. Based on the modelling equations, the indirect field-oriented control (IFOC) is proposed for PPMIM drives by reflecting the associated changes in parameters for different pole phase modes. In the IFOC, for regulating the d-axis and q-axis current components, single PI control loops have been implemented for all pole-phase combinations. The proposed IFOC scheme is robust and applicable for adopting any type of pulse width modulation. The experimental, as well as simulation results, are given to illustrate the potentiality of the proposed dynamic model and IFOC. The PPMIM machine performance during the steady state as well as pole changeovers in different pole phase modes are analyzed and associated. Simulation and experimental results are presented. 2022 The Authors. IET Power Electronics published by John Wiley & Sons Ltd on behalf of The Institution of Engineering and Technology. This publication was made possible by QU High Impact Grant # [QUHI-CENG-19/20-2] from Qatar University. The statements made herein are solely the responsibility of the authors. Furthermore, this is to acknowledge that the publication charges of this article was funded by the Qatar National Library, Doha, Qatar. Scopus
- Published
- 2022
27. Equivalent-input-disturbance-based robust control of drilling trajectory with weight-on-bit uncertainty in directional drilling
- Author
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Luefeng Chen, Xuzhi Lai, Chengda Lu, Min Wu, and Zhen Cai
- Subjects
Observer (quantum physics) ,Computer science ,Applied Mathematics ,Directional drilling ,Drilling ,Computer Science Applications ,Azimuth ,Control and Systems Engineering ,Control theory ,Weight on bit ,Trajectory ,Electrical and Electronic Engineering ,Bottom hole assembly ,Robust control ,Instrumentation - Abstract
Weight-on-Bit is of vital importance to the drilling trajectory orientation in directional drilling. This paper concerns robust control of drilling trajectory with weight-on-bit uncertainty for the directional drilling process. The objective is to develop an equivalent-input-disturbance-based trajectory control scheme such that the drilling trajectory is precisely controlled by suppressing the fluctuations of weight-on-bit. The motion orientation of both the drill bit and a series of stabilizers is used to describe the evolution process of the drilling trajectory. A state-space model with weight-on-bit uncertainty is derived from the evolution equation through a variable transformation. An equivalent-input-disturbance-based trajectory control system is designed, and two control loops are to track and control the trajectory inclination and azimuth, respectively. Two internal models track the trajectory inclination and azimuth respectively to elevate the control accuracy in the trajectory system. Two observer models combined with two low-pass filters estimate the trajectory inclination and azimuth by measuring the bottom hole assembly’s inclination and azimuth. Some sufficient conditions are derived using linear-matrix-inequalities to obtain the control parameters by considering a reasonable fluctuation range of weight-on-bit. Finally, the control effects in the build-up and horizontal section of the drilling trajectory illustrate the proposed approach’s validity.
- Published
- 2022
28. Tube-Based Output Feedback Robust MPC for LPV Systems With Scaled Terminal Constraint Sets
- Author
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Junying Yao, Baocang Ding, Zhiwu Li, and Xubin Ping
- Subjects
Optimization problem ,Computer science ,Scheduling (production processes) ,Stability (learning theory) ,Computer Science Applications ,Human-Computer Interaction ,Constraint (information theory) ,Model predictive control ,Online optimization ,Control and Systems Engineering ,Control theory ,Bounded function ,Electrical and Electronic Engineering ,Invariant (mathematics) ,Robust control ,Software ,Information Systems - Abstract
This article provides a solution to tube-based output feedback robust model predictive control (RMPC) for discrete-time linear parameter varying (LPV) systems with bounded disturbances and noises. The proposed approach synthesizes an offline optimization problem to design a look-up table and an online tube-based output feedback RMPC with tightened constraints and scaled terminal constraint sets. In the offline optimization problem, a sequence of nested robust positively invariant (RPI) sets and robust control invariant (RCI) sets, respectively, for estimation errors and control errors is optimized and stored in the look-up table. In the online optimization problem, real-time control parameters are searched based on the bounds of time-varying estimation error sets. Considering the characteristics of the uncertain scheduling parameter in LPV systems, the online tube-based output feedback RMPC scheme adopts one-step nominal system prediction with scaled terminal constraint sets. The formulated simple and efficient online optimization problem with fewer decision variables and constraints has a lower online computational burden. Recursive feasibility of the optimization problem and robust stability of the controlled LPV system are guaranteed by ensuring that the nominal system converges to the terminal constraint set, and uncertain state trajectories are constrained within robust tubes with the center of the nominal system. A numerical example is given to verify the approach.
- Published
- 2022
29. Adaptive robust control for triple avoidance - striking - arrival performance of uncertain tank mechanical systems
- Author
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Yu-ze Ma, Qinqin Sun, Zong-fan Wang, Guolai Yang, and Xiuye Wang
- Subjects
0209 industrial biotechnology ,Computer science ,Mechanical Engineering ,Control (management) ,Metals and Alloys ,Computational Mechanics ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,02 engineering and technology ,Tracking (particle physics) ,01 natural sciences ,010305 fluids & plasmas ,Mechanical system ,Constraint (information theory) ,020901 industrial engineering & automation ,Control theory ,Bounded function ,0103 physical sciences ,Ceramics and Composites ,Control signal ,Robust control - Abstract
This paper puts forward an unprecedented avoidance-striking-arrival problem aiming to address the need for tank's uncertain mechanical systems on the intelligent battlefield. The associated system uncertainties (possibly rapid) are time-varying but bounded (possibly unknown). The goal is to design a controller that enables the tank to aim at and attack the enemy tank while keeping itself (out of the enemy fire zone). The tank maintains this condition until reaching the predefined region. In this paper, an approximate constraint following control method is adopted to solve this problem, and the original constraints are creatively divided into two categories: the avoidance - tracking constraint and the striking - arrival constraint. An adaptive robust control method is proposed and consequently verified through simulation experiments. It is proved that the system fully obeys the avoidance - tracking - constraint and strictly obeys the striking - arrival constraint under the control input τ . Besides, the control of the tank vehicle running system and tank gun bidirectional stabilization system are unified to deal with the control signal delay caused by complex uncertainties on the battlefield. Overall, this paper reduced the delay of signal transmission in the system while solved the avoidance - striking - arrival problem.
- Published
- 2022
30. Path Tracking Control for Underactuated Vehicles With Matched-Mismatched Uncertainties: An Uncertainty Decomposition Based Constraint-Following Approach
- Author
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Diange Yang, Zeyu Yang, Hui Yin, Jin Huang, and Zhihua Zhong
- Subjects
Lyapunov function ,Underactuation ,Computer science ,Mechanical Engineering ,Servo control ,Kinematics ,Minimax ,Computer Science Applications ,Constraint (information theory) ,symbols.namesake ,Control theory ,Automotive Engineering ,Path (graph theory) ,symbols ,Robust control - Abstract
This paper presents a robust path tracking control method by utilizing the ideology of constraint-following approach for uncertain underactuated autonomous vehicles. The uncertainties are bounded with an unknown boundary. They do not all fall within the range space of the input matrix. Based on kinematic relations between the desired path and vehicle, the path tracking task is transformed into an equality constraint of the vehicle lateral dynamics states. The control goal is to make the underactuated vehicle follow the constraint, thus realizing the desired tracking performance. The constraint-following robust control (CFRC) is designed in two steps. First, a servo control design for the nominal system is devised without considering uncertainty and initial constraint deviation. Second, the uncertainty is meticulously decomposed into matched and mismatched portions based on the geometric structural characteristics of the constraint dynamics system. As a result, since the mismatched uncertainty is orthogonal to the constraint-following geometric space, it ``disappears'' in the stability analysis. The matched uncertainty is estimated by a self-adjusting leakage type adaptive law. On this basis, a robust control is designed based on the estimated matched uncertainty. Through Lyapunov minimax analysis, the proposed control method guarantees the approximate constraint-following performance. Finally, the TruckSim-Simulink co-simulations and real vehicle experiments are presented. The results show that the proposed control can robustly realize excellent tracking performance in the presence of time-vary uncertainties.
- Published
- 2022
31. High Precision Robust Control for Periodic Tasks of Linear Motor via B-Spline Wavelet Neural Network Observer
- Author
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Weichao Sun, Yanbin Liu, and Huijun Gao
- Subjects
Observer (quantum physics) ,Artificial neural network ,Control and Systems Engineering ,Aperiodic graph ,Control theory ,Computer science ,Trajectory ,Stability (learning theory) ,Electrical and Electronic Engineering ,Linear motor ,Robust control ,Compensation (engineering) - Abstract
As one of the core components of high-end manufacturing equipment, linear motor (LM) plays an important role in high efficiency and high quality production of the equipment. In this paper, a high-precision robust control method with periodic dynamic compensation is proposed for the most common repetitive trajectory tracking task in the manufacturing industry. To overcome the influence of unknown periodic dynamics on the control accuracy, a B-spline wavelet neural network (BSWNN) observer is designed to estimate the uncertainties. Moreover, the control framework in the form of robust control is employed to ensure the stability of the closed-loop system under other unknown aperiodic disturbance. Finally, the high-precision control for LM-driven stage in high-speed environment is realized, and the comparative experiments show that the control accuracy of the proposed method is significantly improved at least 28.9% compared with the other three existing control methods.
- Published
- 2022
32. Finite-Time Output Feedback Robust Controller Based on Tangent Barrier Lyapunov Function for Restricted State Space for Biped Robot
- Author
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Isaac Chairez, Wen Yu, and Karla Rincon
- Subjects
Computer science ,Computer Science Applications ,Human-Computer Interaction ,Tracking error ,Differentiator ,Rate of convergence ,Control and Systems Engineering ,Control theory ,Convex optimization ,State space ,Electrical and Electronic Engineering ,Robust control ,Realization (systems) ,Software - Abstract
This study has the aim of introducing a new type of trajectory tracking robust controllers for a class of rehabilitation robotic system considering the articulations restrictions. The robotic device consists of a suspended biped configuration. The suggested robust control considers the application of state depending gains which provide finite-time convergence for the tracking deviation. The state restrictions are fulfilled by the implementation of controller gains estimated by a class of the controlled tangent barrier Lyapunov function. Stability analysis for the tracking error yields the explicit design of the state dependent gains. The rate of convergence for the controller design is enhanced using a matrix inequality convex optimization method. Based on the forward complete characteristic of the suggested rehabilitation device, it is allowed using a finite-time convergent super-twisting-based differentiator to concrete an output feedback realization of the proposed controller. A computerized model of the tendered rehabilitation robot provides a reliable testing platform to the suggested roust controller. Numerical evaluations appear to serve as an indirect confirmation for the tracking error convergence, satisfying the articulation restrictions, and the effect of the gain optimization design. For comparison purposes, the regular state feedback control design is considered as benchmark. The faster convergence of the mean square estimation of the tracking error justifies the design of the proposed control design as well as the state feedback structure justifies the origin is a fixed-time stable equilibrium point for the space of tracking error at the same time that state space restrictions remain satisfied. The experimental evaluations of the proposed controller justifies the barrier controller which, in spite of the modeling uncertainties and the implementation issues, tracked the reference trajectories.
- Published
- 2022
33. Output-Based Event-Triggered Cooperative Robust Regulation for Constrained Heterogeneous Multiagent Systems
- Author
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Di Yu, Xiaobing Zhang, Peng Wang, and Shuzhi Sam Ge
- Subjects
Human-Computer Interaction ,Observer (quantum physics) ,Control and Systems Engineering ,Control theory ,Computer science ,Multi-agent system ,State (computer science) ,Interval (mathematics) ,Electrical and Electronic Engineering ,Robust control ,Software ,Computer Science Applications ,Information Systems - Abstract
The output-based event-triggered cooperative output regulation problem is addressed for constrained linear heterogeneous multiagent system in this article. In light of the robust control theory, H∞ leader-following consensus with respect to exogenous signals, including both disturbance to be rejected and reference state of leader to be tracked, is guaranteed. Meanwhile, the system performance alleviates degradation through a model recovery anti-windup technique while encountering input saturation. Furthermore, the follower's self-state observer, the leader-state observer, and the anti-windup auxiliary system are integrated into a comprehensive system, and a unified event-triggering mechanism of full states is addressed. A fixed lower bound of sampled interval is adopted such that the frequency of data transmission gets reduced and no Zeno-behavior happens. Both the input and output of the follower's controller and anti-windup compensator hold constant, respectively, during the event-triggered intervals such that the resulting output-based event-triggered controller can be directly implemented in a digital platform. Finally, a simulation example is provided to illustrate the effectiveness.
- Published
- 2022
34. Cooperative Game Approach to Robust Control Design for Fuzzy Dynamical Systems
- Author
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Baokun Han, Rongrong Yu, and Ye-Hwa Chen
- Subjects
Lyapunov function ,Dynamical systems theory ,Computer science ,Fuzzy set ,Pendulum ,Boundary (topology) ,Minimax ,Computer Science Applications ,Human-Computer Interaction ,symbols.namesake ,Control and Systems Engineering ,Control theory ,Bounded function ,symbols ,Uniform boundedness ,Electrical and Electronic Engineering ,Robust control ,Software ,Information Systems - Abstract
There is uncertainty in the system, and we consider that uncertainty is (possibly fast) time varying, but with definite bound. Fuzzy set theory is used to describe the inexact boundary and then the problem of robust control of uncertain dynamical systems is studied. Based on two adjustable design parameters, a robust control method for general mechanical systems is proposed. The control is deterministic, not the conventional IF-THEN rule based. By using the Lyapunov minimax approach, it is proved that the proposed control can guarantee system performance to be uniformly bounded and uniformly ultimately bounded. In order to find the optimal solution in the prescribed range, a two-player cooperative game is used. To reduce costs while ensuring control performance, two performance indices are developed, each of which is controlled by an adjustable parameter (i.e., player). Both necessary and sufficient conditions for Pareto-optimality are established. Using these conditions, the Pareto-optimal solution can be obtained. The effectiveness of the control design is demonstrated by the simulation of the two-body pendulum.
- Published
- 2022
35. A Robust Traffic Control Model Considering Uncertainties in Turning Ratios
- Author
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Kenneth A. Perrine, Randy B Machemehl, Hao Liu, and Christian Claudel
- Subjects
050210 logistics & transportation ,Mathematical optimization ,Computer science ,Mechanical Engineering ,05 social sciences ,Control (management) ,Diagram ,Optimal control ,Computer Science Applications ,Model parameter ,Optimization and Control (math.OC) ,0502 economics and business ,Automotive Engineering ,FOS: Mathematics ,Robust control ,Mathematics - Optimization and Control ,Throughput (business) - Abstract
The effects of model parameter uncertainty on traffic flow control problems have recently drawn research attention. While the uncertainty in fundamental diagram related parameters has been investigated in the past, few articles have focused on network parameters uncertainty, including turning ratio uncertainty. To fill this gap, this article proposes a robust control model to deal with the uncertainties in the turning ratio by using distributionally robust chance constraints. The model allows one to compute the optimal control action that maximizes some objective, under all possible distributions of network parameters. We then apply this robust control framework to both a freeway network and an urban network, and evaluate the impact of uncertainty on optimal control inputs, over the test networks. The case studies show that compared to non-robust control, the proposed robust model can reduce congestion brought by the uncertainties and improve the overall throughput., Accepted for publication on IEEE Transactions on Intelligent Transportation Systems
- Published
- 2022
36. Precision Motion Control of an Independent Metering Hydraulic System With Nonlinear Flow Modeling and Compensation
- Author
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Litong Lyu, Bobo Helian, Zheng Chen, Chen Li, and Bin Yao
- Subjects
Nonlinear system ,Flow (mathematics) ,Control and Systems Engineering ,Computer science ,Control theory ,Control system ,ComputingMethodologies_MISCELLANEOUS ,Deadband ,Metering mode ,Electrical and Electronic Engineering ,Hydraulic machinery ,Robust control ,Motion control - Abstract
The independent metering system decouples the meter-in and meter-out flows of the chamber, giving extra control flexibility and can reducing energy consumption while keeping motion control accuracy. The control performance of the independent metering system is significantly determined by the valve characteristics. Valve nonlinearities, such as deadband, nonlinear flow gain, and leakage, may restrict the control accuracy. To address the issue and improve system control precision, the nonlinearities of the valve need to be further modeled. In this study, a nonlinear valve flow model is proposed to accurately depict the relationships between the flow rate, pressure drop, and input voltage. The valve deadband is compensated by the static inverse function, while a certain polynomial projection function is used to mimic the nonlinear flow curve outside the deadband. To deal with uncertainties and nonlinearities in the independent metering system, an adaptive robust control approach is synthesized. The least squares estimation law is adopted to online adapt the valve parameter and other system parameters. Comparative experiments were carried out to illustrate the effectiveness of the proposed approach. The results show that the valve flow nonlinearities are further captured by the proposed model, and the independent metering system performed a higher-level control precision.
- Published
- 2022
37. Variable-Parameter-Dependent Saturated Robust Control for Vehicle Lateral Stability
- Author
-
Panshuo Li, James Lam, Hongyi Li, and Renquan Lu
- Subjects
Lyapunov function ,Distribution (number theory) ,Computer science ,Stiffness ,Matrix (mathematics) ,symbols.namesake ,Control and Systems Engineering ,Control theory ,medicine ,symbols ,Torque ,Electrical and Electronic Engineering ,Robust control ,medicine.symptom ,Variable (mathematics) - Abstract
This article proposes a novel gain-scheduling control method to improve vehicle lateral stability based on a variable-parameter-dependent approach. A time-varying velocity-dependent model to describe the vehicle lateral dynamic characteristics is constructed under cornering stiffness uncertainties and controller saturation. A novel Lyapunov function with variable-parameter-dependent Lyapunov matrix is established to develop the conditions. Using the proposed Lyapunov function, a general condition of the variable-parameter-dependent saturated robust yaw moment controller is provided in terms of time-varying parameter-dependent matrix inequalities. In order to obtain a tractable solution, a condition is further developed with finite linear matrix inequalities. Moreover, an optimal distribution method is adopted to generate the desired yaw moment based on torque allocation. These torques are computed by optimizing the distribution errors and tire workloads. Simulations results under both J-turn and double-lane changing scenarios are used to illustrate the merits of the proposed method. The control synthesis approach is also applicable to other applications involving time-varying parameters.
- Published
- 2022
38. Novel Compliant Control of a Pneumatic Artificial Muscle Driven by Hydrogen Pressure Under a Varying Environment
- Author
-
Thananchai Leephakpreeda and Thanana Nuchkrua
- Subjects
Adaptive control ,Control and Systems Engineering ,Computer science ,Artificial muscle ,Control engineering ,Electrical and Electronic Engineering ,Robust control ,Bayesian inference ,Adaptation (computer science) ,Actuator ,Human–robot interaction ,Parametric statistics - Abstract
A pneumatic artificial muscle (PAM) based on a metal hydride (MH) is considered for a compact compliant actuator. It is suitable for board applications of human robot interaction (HRI). To address the problem of HRI representing by varying environment, a compliant control is introduced. In fact, the bottlenecks of improving the performance in the compliant control of the PAM actuator are: a) an inherent non-linear dynamics of a PAM, b) the parametric and non-linear uncertainties, influenced by varying environment, and c) an additional high dimension introduced by an MH employed as a driving force for the PAM. We propose a learning-based adaptive robust control (LARC) framework to tackle these challenges. A Bayesian learning technique deals with the parameter adaptation for the adaptive control. The effectiveness of the LARC has been examined in extensive experiments of tracking control.
- Published
- 2022
39. Fuzzy-Set Theoretic Control Design for Aircraft Engine Hardware-in-the-Loop Testing: Mismatched Uncertainty and Optimality
- Author
-
Muxuan Pan, Ye-Hwa Chen, Yun Xun, Binbin Gu, and Jinquan Huang
- Subjects
Optimal design ,Fuzzy rule ,Flight envelope ,Control and Systems Engineering ,Computer science ,Control theory ,Fuzzy set ,Hardware-in-the-loop simulation ,State vector ,Electrical and Electronic Engineering ,Robust control ,Fuzzy logic - Abstract
A multivariable robust control design for aircraft engines is proposed. The engine is modeled as a fuzzy dynamic system (FDS), which is not the same as Takagi-Sugeno inference system, based on a series of state vector models in the flight envelope. The possible value of uncertainty is prescribed to be within fuzzy sets. The uncertainty is divided into the matched and the mismatched portions. While the matched uncertainty lies within the range space of the input matrix, the mismatched uncertainty falls outside, which poses a significant challenge for control design. A robust control, which is deterministic and is not IF-THEN fuzzy rule based, is designed. The control design parameter needs to be feasible, i.e., within a prescribed range. Some prescribed deterministic performances of the system are guaranteed under the control, regardless of the uncertainty. By taking the control cost and the performance threshold into consideration, which is under the influence of both matched and mismatched uncertainty, the optimal choice of the control parameter is explored. As a result, this control design delicately blends optimality with mismatched uncertainty. This design is applied to a turbofan engine. HIL (hardware-in-the-loop) laboratory testing in the flight envelope demonstrates the superiority of the control design.
- Published
- 2022
40. High dynamic output feedback robust control of hydraulic flight motion simulator using a novel cascaded extended state observer
- Author
-
Jianyong Yao, Xiaochao Liu, Zongxia Jiao, and Wenxiang Deng
- Subjects
Noise ,Computer science ,Control theory ,Mechanical Engineering ,Backstepping ,Feed forward ,Aerospace Engineering ,Motion simulator ,State observer ,Performance improvement ,Robust control - Abstract
High dynamic tracking performance is a key technical index of hydraulic flight motion simulator (HFMS). However, the strong nonlinearities, various model uncertainties and measurement noise in hydraulic actuation systems limit the high dynamic performance improvement. In this paper, the outer axis frame of a HFMS is taken as a case study and its nonlinear dynamic model with consideration of strong nonlinearities, matched and mismatched uncertainties is established. A novel cascaded extended state observer (ESO) is proposed to estimate the unavailable system states to avoid the adverse effect of measurement noise on control performance. Meanwhile, the designed cascaded ESO also produces estimates of matched and mismatched uncertainties. Then, an output feedback robust controller (OFRC) is proposed by integrating the cascaded ESO with a robust integral of the sign of the error (RISE) feedback based on the backstepping framework. The proposed controller achieves compensation of both matched and mismatched model uncertainties in an output feedback form. Theoretical analysis indicates that the proposed OFRC ensures the boundedness of all closed-loop system signals in the presence of matched and mismatched time-varying model uncertainties. Excellent asymptotic tracking performance can also be obtained when the model uncertainties are time-invariant. Comparative experimental results show that the proposed OFRC achieves significant performance improvement compared with the extensively employed PI control with velocity feedforward (VFPI).
- Published
- 2022
41. Interval-Arithmetic-Based Robust Control of Fully Actuated Mechanical Systems
- Author
-
Stefan B. Liu, Andrea Giusti, Matthias Althoff, and Publica
- Subjects
Mechanical system ,Control and Systems Engineering ,Computer science ,Control theory ,Electrical and Electronic Engineering ,Robust control ,ddc ,Interval arithmetic - Abstract
We propose a control approach for fully actuated mechanical systems using interval arithmetic, which guarantees global uniform ultimate boundedness of the tracking error and robust performance despite model uncertainties and input disturbances. Existing robust control methods often require computationally expensive or empirical estimations of bounds of state-dependent, nonlinear perturbations, arising from model mismatches. Our robust feedback control approach is different and removes these difficulties by using interval arithmetic to determine online the worst case perturbation acting on the error dynamics. We present two interval-arithmetic-based robust controllers by robustifying inverse-dynamics and passivity-based nominal control schemes. The effectiveness of our approach is demonstrated on a real robot manipulator with uncertain dynamics.
- Published
- 2022
42. Robust Output Regulation: Optimization-Based Synthesis and Event-Triggered Implementation
- Author
-
Peyman Mohajerinesfahani, Mohammad Saleh Tavazoei, Anton V. Proskurnikov, and Mohammad Saeed Sarafraz
- Subjects
Optimization ,element-wise uncertainty ,Computer science ,Measurement uncertainty ,Robust control ,Systems and Control (eess.SY) ,System dynamics ,Electrical Engineering and Systems Science - Systems and Control ,event-triggered control ,Symmetric matrices ,Control theory ,FOS: Mathematics ,FOS: Electrical engineering, electronic engineering, information engineering ,Electrical and Electronic Engineering ,Mathematics - Optimization and Control ,optimization-based synthesis ,Emulation ,Uncertainty ,Computer Science Applications ,Nonlinear system ,Regulation ,Optimization and Control (math.OC) ,Control and Systems Engineering ,Bounded function ,Parametric family - Abstract
In this article, we investigate the problem of practical output regulation, i.e., to design a controller that brings the system output in the vicinity of a desired target value while keeping the other variables bounded. We consider uncertain systems that are possibly nonlinear and the uncertainty of their linear parts is modeled element wise through a parametric family of matrix boxes. An optimization-based design procedure is proposed that delivers a continuous-time control and estimates the maximal regulation error. We also analyze an event-triggered emulation of this controller, which can be implemented on a digital platform, along with an explicit estimate of the regulation error.
- Published
- 2022
43. Event-Triggered Robust Control for Output Consensus of Unknown Discrete-Time Multiagent Systems With Unmodeled Dynamics
- Author
-
Gang Feng, Lu Liu, and Ruohan Yang
- Subjects
0209 industrial biotechnology ,Adaptive control ,Computer science ,Multi-agent system ,Distributed element model ,02 engineering and technology ,Computer Science Applications ,Human-Computer Interaction ,020901 industrial engineering & automation ,Discrete time and continuous time ,Consensus ,Control and Systems Engineering ,Control theory ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Electrical and Electronic Engineering ,Robust control ,Software ,Information Systems - Abstract
This article investigates the event-triggered output consensus problem for a class of unknown heterogeneous discrete-time linear multiagent systems in the presence of unmodeled dynamics. The agents have individual nominal dynamics with unknown parameters, and the unmodeled dynamics are in the form of multiplicative perturbations. A novel design framework is developed based on an event-triggered internal reference model and a distributed model reference adaptive controller. To deal with the heterogeneity of the multiagent system, the event-triggered internal reference model is designed to generate a virtual reference signal for each agent with a dynamic event-triggering mechanism being adopted to reduce the communication burden between neighboring agents. To handle the unknown parameters and unmodeled dynamics, the robust model reference adaptive controller is then designed to follow the generated virtual reference signal. It is shown that if the unmodeled dynamics satisfy certain conditions, then the boundedness of all the signals and variables in the closed-loop system and convergence of consensus errors to a residual set are guaranteed. Moreover, the consensus errors will converge to zero asymptotically in the absence of unmodeled dynamics. Compared with existing related works, the proposed framework is able to deal with the agents with individual unknown nominal dynamics and unmodeled dynamics. Moreover, the proposed framework is fully distributed in the sense that no knowledge of any global information is needed. Finally, the performance of the proposed method is validated by examples.
- Published
- 2022
44. A model-free continuous integral sliding mode controller for robust control of robotic manipulators
- Author
-
Gunyaz Ablay
- Subjects
robotic manipulators ,sliding mode control ,Building and Construction ,Electrical and Electronic Engineering ,model-free control ,robust control ,robot control - Abstract
This paper proposes a model-free continuous integral sliding mode controller for robust control of robotic manipulators. The highly nonlinear dynamics of robots and load disturbances cause control challenges. To achieve tracking control under load disturbances and nonlinear parameter variations, the controller is constructed with three continuous terms including an integral term that acts as an adaptive controller. The proposed controller is able to accomplish a non-overshoot transient response, a short settling time, and strong disturbance rejection performance for robotic manipulators. The developed model-free control method is implemented on the PUMA 560 robotic manipulator, and its performance is compared with the proportional-derivative (PD) plus gravity controller. Numerical results under measurement noise and load disturbances are provided in order to show the efficacy, validity, and feasibility of the method.
- Published
- 2023
45. Adaptive Robust Impedance Control for an Ear Surgical Device With Soft Interaction
- Author
-
Jie Ling, Wenyu Liang, Kok Kiong Tan, Tong Heng Lee, Xiaohui Xiao, and Zhao Feng
- Subjects
Lyapunov function ,Computer science ,Impedance parameters ,Computer Science Applications ,symbols.namesake ,Impedance control ,Control and Systems Engineering ,Control theory ,Robustness (computer science) ,Control system ,symbols ,Electrical and Electronic Engineering ,Robust control ,Electrical impedance - Abstract
The required suitably soft-contact interaction in certain surgical device applications brings great challenges on the force and position control because the soft-contact environment is nonlinear, viscoelastic, and inhomogeneous. In this paper, a novel adaptive robust control approach, namely adaptive integral terminal sliding-mode-based impedance control (AITSMIC), is formulated to simultaneously regulate and control the position and force for a piezo-actuated ear surgical device with soft interaction. Firstly, the target impedance's steady-state performance is discussed by utilizing the nonlinear Hunt-Crossley model. To achieve the desired impedance, an integral terminal sliding manifold based on the auxiliary variable containing the impedance error is proposed to improve tracking performance and obtain the required finite-time convergence. Furthermore, an adaptive law is designed to get rid of system nonlinearities, uncertainties and disturbances, and to retain high robustness. The stability of the proposed control system is proven via the Lyapunov theory. Significantly, implementing the AITSMIC is straightforward, where only essentially one uniform controller is applied. Finally, several experiments are conducted to evaluate the effects of associated impedance parameters, verify the force tracking performance and validate the suitably practical application of AITSMIC on the procedure of ear surgery with soft interaction. The results show that excellent tracking performance and successful operation are achieved by the proposed controller.
- Published
- 2022
46. Series Active Variable Geometry Suspension: Full-Car Prototyping and Road Testing
- Author
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Cheng Cheng, Daniele Dini, Min Yu, Simos A. Evangelou, and Engineering & Physical Science Research Council (EPSRC)
- Subjects
Technology ,Materials science ,full-car prototype ,Vehicle dynamics ,Automation & Control Systems ,Engineering ,DESIGN ,Prototypes ,road testing ,Electrical and Electronic Engineering ,Suspension (vehicle) ,Active suspension ,Science & Technology ,Series (mathematics) ,business.industry ,Suspensions (mechanical systems) ,IEEE transactions ,Engineering, Electrical & Electronic ,Structural engineering ,Mechatronics ,0910 Manufacturing Engineering ,Roads ,Computer Science Applications ,Engineering, Manufacturing ,Engineering, Mechanical ,0906 Electrical and Electronic Engineering ,Industrial Engineering & Automation ,Control and Systems Engineering ,Variable geometry ,business ,Automobiles ,robust control ,0913 Mechanical Engineering - Abstract
In this paper, afull-car prototype of the recently proposed mechatronic suspension, Series Active Variable Geometry Suspension (SAVGS), is developed for on-road driving experimental proof of concept, aiming to be adopted by suspension OEMs (original equipment manufacturers) as an alternative solution to fully active suspensions. Particularly, mechanical modifications are performed to both corners of the front double-wishbone suspensionof a production car, with active single-links attached to the upper-ends of the spring-damper units, while both corners of the rear suspension remain inthe original (passive) configurations.The mechanical modifications involve innovatively designed parts to enable the desired suspension performance improvements, while maintaining ride harshness at conventional levels.Areal-time embedded system is further developed to primarily implement:1) power supply, data acquisition and measurementsof the vehicle dynamics related variables, and 2) robust control application for the ride comfort and road holding enhancement, which is based on a derived linearized model of the full-car dynamics and a newly synthesizedH-infinity control scheme. Results obtained from on-road driving experiments are inessential agreement with numerical simulation results also produced. Overall, the full-car prototypeof SAVGS demonstrates promising suspension performance,with anaverage 3 dB attenuation (or equivalently 30% reduction) of the chassis vertical acceleration at aroundthe human-sensitive frequencies (2-5Hz),as compared to the original vehicle with the passive suspension system. More importantly, the prototype also indicatesthe practicality of the solution, as the SAVGS retrofit to a real car is achieved by simple mechanical modifications, compact actuator packaging, smallmass increment(21.5kg increase with respect to the original vehicle), limited power usage (an average value of 134W in DC batteries with a Class D random road) and acceptable economic cost.
- Published
- 2022
47. Robust Control of Connected Cruise Vehicle Platoon With Uncertain Human Driving Reaction Time
- Author
-
Zhanrui Xu and Xiaohong Jiao
- Subjects
Control and Optimization ,Artificial Intelligence ,Computer science ,Control theory ,Automotive Engineering ,Cruise ,Platoon ,Robust control - Published
- 2022
48. Robust Output Feedback MPC for LPV Systems Using Interval Observers
- Author
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Alex dos Reis de Souza, Tarek Raïssi, Denis Efimov, Finite-time control and estimation for distributed systems (VALSE), Inria Lille - Nord Europe, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre de Recherche en Informatique, Signal et Automatique de Lille - UMR 9189 (CRIStAL), Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Centre d'études et de recherche en informatique et communications (CEDRIC), Ecole Nationale Supérieure d'Informatique pour l'Industrie et l'Entreprise (ENSIIE)-Conservatoire National des Arts et Métiers [CNAM] (CNAM), HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM), and This work was partially supported by the IPL COSY, and by the Ministry of Science and Higher Education of Russian Federation, passport of goszadanie n° 2019-0898.
- Subjects
0209 industrial biotechnology ,output feedback ,Observer (quantum physics) ,Computer science ,Stability (learning theory) ,02 engineering and technology ,Interval (mathematics) ,Constraint satisfaction ,[SPI.AUTO]Engineering Sciences [physics]/Automatic ,Computer Science Applications ,Model predictive control ,020901 industrial engineering & automation ,Control and Systems Engineering ,Control theory ,Bounded function ,Predictive control ,Electrical and Electronic Engineering ,Robust control ,robust control - Abstract
International audience; This work addresses the problem of robust output feedback model predictive control for discrete-time, constrained, linear parameter-varying systems subject to (bounded) state and measurement disturbances. The vector of scheduling parameters is assumed to be an unmeasurable signal taking values in a given compact set. The proposed controller incorporates an interval observer, that uses the available measurement to update the setmembership estimation of the states, and an interval predictor, used in the prediction step of the MPC algorithm. The resulting MPC scheme offers guarantees on recursive feasibility, constraint satisfaction, and input-to-state stability in the terminal set. Furthermore, this novel algorithm shows low computation complexity and ease of implementation (similar to conventional MPC schemes).
- Published
- 2022
49. PMSM Current Harmonics Control Technique Based on Speed Adaptive Robust Control
- Author
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Zechang Sun, Daolian Chen, Xinjian Wang, and Peng Yi
- Subjects
Inductance ,Test bench ,Control theory ,Computer science ,Harmonics ,Automotive Engineering ,Harmonic ,Energy Engineering and Power Technology ,Transportation ,Torque ripple ,Transient (oscillation) ,Electrical and Electronic Engineering ,Robust control - Abstract
Permanent magnet synchronous motor (PMSM) is widely used in electric vehicles due to its high power density. New requirements are constantly proposed with the development of PMSM, one of which is torque ripple. Current harmonic injection is a common method to minimize torque ripple. Designing effective controller to realize current harmonic injection is the key technology. In this paper, the transient voltage-current coupling equation considering magnetic saturation is derived by introducing incremental inductance. After appropriately simplifying, it is shown in form of the harmonic state space (HSS) equation. Considering that PMSM parameters varies with current due to magnetic saturation, robust controller is adopted to ensure stability. In order to eliminate the influence of motor speed change on control stability, the HSS is transformed into a spatial form. Then the speed adaptive robust (SAR) controller is designed. At last, the SAR controller is used in simulation and test bench experiment to verify dynamic response and stability. Compared with traditional PI and PR controller, the SAR controller can ensure good dynamic response, steady-state error and robust stability when speed and PMSM parameters vary. Moreover, SAR controller can well resist the harmonic coupling effect and system lag.
- Published
- 2022
50. Design and Optimization of Robust Path Tracking Control for Autonomous Vehicles With Fuzzy Uncertainty
- Author
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Jin Huang, Zeyu Yang, Yang Diange, and Zhihua Zhong
- Subjects
Scheme (programming language) ,Computer science ,Applied Mathematics ,Control (management) ,Fuzzy set ,Fuzzy control system ,Kinematics ,Fuzzy logic ,Computational Theory and Mathematics ,Artificial Intelligence ,Control and Systems Engineering ,Control theory ,Uniform boundedness ,Robust control ,computer ,computer.programming_language - Abstract
Uncertainty is a major concern in vehicle path tracking control design. The coefficients of the uncertainty bound are unknown. They are assumed to lie within prescribed fuzzy sets. First, based on the path tracking kinematic model, this paper innovatively formulates the vehicle path tracking task as a constraint-following problem. Second, we put forward a deterministic adaptive robust control law with a tunable parameter to ensure the uniform boundedness and ultimate uniform boundedness of the closed-loop system. Third, an optimal scheme for the tunable parameter is proposed based on the fuzzy uncertainty. The resulting optimal robust control (ORC) minimizes a comprehensive fuzzy performance index that involves the fuzzy system performance and the control cost. The results of the CarSim-Simulink co-simulation and the Hardware-in-loop (HIL) experiment together show that the proposed optimal robust control exhibits a superior path tracking performance.
- Published
- 2022
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