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This article presents the robust lateral control of an autonomous vehicle in the presence of unknown lateral tire forces, road curvature angle, and parametric uncertainties. The sliding mode control (SMC) with barrier Lyapunov function is implemented to guarantee the system robustness while maintaining the outputs of the system in realistic bounds. Following the model reduction approach, the slow and fast dynamics of the system are separately controlled using the proposed control technique. The efficacy of the proposed control technique is examined by comparing the simulation results with conventional sliding mode control in two-time scales.

Purpose This paper aims to devise a robust controller for the non-linear aircraft model using output feedback control topology in the presence of uncertain aerodynamic parameters. Design/methodology/approach Feedback linearization-based state feedback (SFB) controller is considered along with a robust outer loop control which is designed using Lyapunov’s second method. A high-gain observer (HGO) in accordance with the separation principle is used to implement the output feedback (OFB) control scheme. The robustness of the controller and observer is assessed by introducing uncertain aerodynamics coefficients in the dynamic model. The proposed scheme is validated using MATLAB/SIMULINK. Findings The efficacy of the proposed scheme is authenticated with the simulation results which show that HGO-based OFB control achieves the SFB control performance for a small value of the high-gain parameter in the presence of uncertain aerodynamic parameters. Originality/value A HGO for the non-linear model of aircraft with uncertain parameters is a novel contribution which could be further used for the unmanned aerial vehicles autopilot, flight trajectory tracking and path following.

In this article, a finite-time robust tracking control of output constrained multirotor unmanned aerial vehicle (UAV) is proposed. A finite-time sliding mode control (SMC) technique with barrier Lyapunov function (BLF) is used to assure robustness of the derived control laws while maintaining the output in specified constraints. A comparison of the proposed controller is carried out with conventional SMC to manifest the effectiveness of the output-constrained tracking control. Numerical simulations of quadrotor UAV with exogenous disturbances and time-invariant output constraints demonstrate the efficacy of the proposed controller regarding robustness, finite-time convergence, and chattering reduction.

This article focuses on the output feedback control of single-link flexible-joint robot manipulators (SFJRMs) with matched disturbances and parametric uncertainties. Formally, four sensing elements are required to design the controller for single-link manipulators. We have designed a robust control technique for the semiglobal stabilization problem of the angular position of the link in the SFJRM system, with the availability of only a position sensing device. The sliding mode control (SMC) based output feedback controller is devised for SFJRM dynamics. The nonlinear model of SFJRM is considered to estimate the unknown states utilizing the high-gain observer (HGO). It is shown that the output under SMC using HGO-based estimated states coincides with that using original states when the gains of HGO are sufficiently high. Finally, the results are presented showing that the designed control technique works well when the SFJRM model is uncertain and matched perturbations are expected.

The robust decentralized formation control for the multiagent quadrotor is investigated in this article. The leaderless formation protocol is proposed for a class of square multi-input multi-output nonlinear multiagent systems with an undirected communication graph. The six degree of freedom underactuated nonlinear model of multiagent quadrotor is considered and altered to a four-input four-output model by stabilizing two states internally using sliding mode control (SMC). Later, the sliding mode-based finite-time position, altitude and heading formation is established based on Lyapunov stability theory. The numerical simulations are performed using MATLAB/ Simulink which validate the proposed formation protocol.

In this modern era research in mechanical ventilator model designing has increased a lot. Mathematical model of lungs is used to distinguish the pulmonary diseases. In this work bond graph model of breathing mechanism i.e. inspiration and expiration of lungs is developed. Hydraulic analogies are allocated to lungs using cylinders and accumulators. From nostrils to trachea single cylinder is considered having resistance and compliance effect associated with it. Trachea to lower lung section comprised of 23 generations of airways. In this study, 2 generations are considered with resistance, compliance and inertial effect, whereas resistance and compliance effect, of 3rd to 17th generations are lumped. These generations are modelled with cylinders with decreasing sizes. 17 to 23 are modelled as accumulators with resistance and compliance. Model parameters were estimated using grey box estimation.20 sim is used to make the bond graph model and determine the relationship of pressure and volume curves. Model can be used for screening of lungs diseases. Model can be used for clinical trials with any existing mechanical ventilator.

Micro gyroscopes are among the rapidly aggrandizing field of the micro electro mechanical systems (MEMS), which is procured with its extensive range of applications around the globe. This paper depicts an innovated approach of designing and modeling of a novel brawny multi-mass gyroscope to acquire dynamic motion amplification and spacious bandwidth. The proposed resonator block is accompanied by a series of proof masses coupled to each other where the primary mass defines the driving unit, secondary mass passes on the dynamic energy, tertiary mass is oscillating mass. The main crux of this design is that increasing the number of masses ameliorates the model with respect to amplification by manifolds and enhances the bandwidth. To analyze this structural model, assistance of finite element method (FEM) based analysis is pursued and simulations are carried out for the examination of distinct frequency modes and frequency response of this robust system. The wide bandwidth of over 3 kHz is achieved by this proposed dynamic model.

This paper presents the design and analysis of a multi degree of freedom (DOF) electro-thermally actuated non-resonant MEMS gyroscope with a 3-DOF drive mode and 1-DOF sense mode system. The 3-DOF drive mode system consists of three masses coupled together using suspension beams. The 1-DOF system consists of a single mass whose motion is decoupled from the drive mode using a decoupling frame. The gyroscope is designed to be operated in the flat region between the first two resonant peaks in drive mode, thus minimizing the effect of environmental and fabrication process variations on device performance. The high gain in the flat operational region is achieved by tuning the suspension beams stiffness. A detailed analytical model, considering the dynamics of both the electro-thermal actuator and multi-mass system, is developed. A parametric optimization is carried out, considering the microfabrication process constraints of the Metal Multi-User MEMS Processes (MetalMUMPs), to achieve high gain. The stiffness of suspension beams is optimized such that the sense mode resonant frequency lies in the flat region between the first two resonant peaks in the drive mode. The results acquired through the developed analytical model are verified with the help of 3D finite element method (FEM)-based simulations. The first three resonant frequencies in the drive mode are designed to be 2.51 kHz, 3.68 kHz, and 5.77 kHz, respectively. The sense mode resonant frequency is designed to be 3.13 kHz. At an actuation voltage of 0.2 V, the dynamically amplified drive mode gain in the sense mass is obtained to be 18.6 &micro, m. With this gain, a capacitive change of 28.11 &nbsp, f F and 862.13 &nbsp, f F is achieved corresponding to the sense mode amplitude of 0.15 &nbsp, &mu, m and 4.5 &nbsp, m at atmospheric air pressure and in a vacuum, respectively.

In modern technological era research in Mechanical Ventilators (MV) has drastically increased in designing model based MV treatment. In model based MV treatment mathematical model of lung is used to detect lungs diseases. In proposed work, inspiration and expiration mechanism of lungs has been modelled using Bond Graphs. Lung segments are assigned Hydraulic analogies using cylinders and accumulators. Upper airway from nostrils to trachea is modelled as single cylinder having resistance and associated compliance effect. Trachea to lower lung segment consists of 23 generations of airways. In this study, 4 generations are considered with their respective resistance and compliance, whereas resistance and compliance effect, of 5th to 17th generations are lumped. These are modelled with cylinders of decreasing size. Generation 17 to 23 are considered as respiratory zone that are modelled as accumulator having compliance and resistance associated. Grey-Box model estimation is used to estimate model parameters of 4 generations and controller is designed. 20 sim software is used to determine the relationship between Pressure (P) and Volume (V) and evaluate the model performance. Model is capable of predicting the true PV curves and thus leading to screening of lungs diseases. Model can be used for clinical trials with any existing MV.