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In this study, a robust adaptive controller is designed to be used in an active tuned mass damper system that can be used to damp undesired vibrations that occurred on the multistory buildings during the earthquake. To realize the controller design, all of the system parameters are assumed to be unknown, and the adaptive structure of the designed controller is obtained by designing adaptive compensation rules for system parameters. A backstepping control design approach is utilized for the control design by considering the appropriateness of the system’s structure of multistory buildings having an active tuned mass damper system at the top of the structure. The proposed control design is supported with a Lyapunov-based stability analysis where it is proven that the designed controller is able to protect the overall system’s stability while reaching the main control purpose. In addition to these, in the simulation studies realized for a nine-story building under the effect of a major earthquake, it is shown that the designed controller can be used to reach the main control purpose efficiently.

The design of a novel backstepping controller for using with active tuned mass damper (ATMD) system is investigated in this study. The main aim of this study is to design the controller for the ATMD system to reduce earthquake-induced vibrations in multistory buildings. Obtaining a generalizable control design for such systems is another important aim of this study. To reach this aim, the designed controller is based on the assumption that the system parameters are completely uncertain. The parametric uncertainty is coped with via adaptive compensation rules proposed in accordance with available system states. Effects of the control force on the displacement of the controller mass and the last floor of a multistory building are considered together. Owing to this approach, a control operation is provided in which zero convergence of the displacement of the mass of ATMD and all floors of the building can be guaranteed. Using Lyapunov-based arguments, theoretically, it has been proven that the designed controller can maintain its stability of the structure and controller mass while achieving this main control objective. The efficiency of the designed controller in terms of reaching the mentioned control objective is observed via numerical simulations. In these simulations, the designed controller is used in conjunction with an ATMD system placed on a multistory building model, and it has been shown that the controller designed in such structures can be used effectively for damping the earthquake-induced vibrations of these types of structures.

Active tuned mass damper (ATMD) devices are recommended in various structures to reduce vibrations. The performance of the ATMD system is closely tied to the control design utilized, according to research in the literature. The designed control input will take into account as much system dynamics as possible, making it possible to use it as a generalized controller in all similar systems. Nonlinear behavior is the natural behavior of engineering structures, and in order to obtain a more realistic and high-performance ATMD system, it can be considered as an appropriate approach to design the controller by considering the structural nonlinearities. In addition, unexpected external influences and parameter uncertainties must be taken into account during control design to ensure that control systems perform successfully in similar systems in all conditions. Therefore, in this study, the nonlinear model of the multi-story building was reconstructed by adding nonlinear disturbance to represent unknown external effects. Band-limited white noise is used as a disturbance function and Gaussian white noise is added to measured states in this study. To obtain a robust controller, unknown structural parameters are compensated for by using adaptive compensation terms. With the controller design supported by the Lyapunov-based stability analysis, the stability of the vibrating structure featuring an ATMD is theoretically guaranteed while achieving the main control goal. Performance analyses of the designed controllers are carried out with simulation studies. The efficiency of the developed Lyapunov-based controller in dampening the unwanted vibrations that occurred on the building is seen in simulation results.

This work concentrates on output feedback trajectory tracking control of marine vehicles with dynamical uncertainties. The system under consideration, due to the natural response of oceanic waves, is also subject to periodic external disturbances. The output feedback structure of the proposed controller algorithm is established via a novel nonlinear model-free observer in conjunction with a Fourier series expansion-based periodic disturbance estimator. Lyapunov-based arguments have been utilized to prove the stability of the closed loop system and the convergence of tracking and unmeasured state observation errors under the closed loop operation. Performance demonstration and viability of the proposed method are realized via comparative numerical simulations.

In this study, a self-tuning robust integral of signum of error (RISE) based controller is designed and used to control a magnetic levitation (maglev) system. In the control design, unlike the classical RISE controller, ‘tanh’ function is used instead of ‘signum’ function to obtain a more smooth control signal. The gains of the controller are updated according to a time-varying update rule. Convergence of the error under the closed-loop operation is proven via Lyapunov-based stability analysis. The controller is tested on an experimental maglev system and successful results are obtained.

DOI: 10.26650/electrica.2018.79181 In this study, an artificial neural network (ANN) model-based self-tuning PID control method is proposed for the control of multi-input-multi-output (MIMO) nonlinear systems. A single layer, feed-forward ANN structure is trained via input and output data randomly collected from the system and classified as learning, test, and validation data to obtain the system model. The obtained model is utilized in an adaptive PID control scheme in conjunction with two different optimization methods for PID tuning and control. Using this scheme, PID parameters can be tuned to their optimum values and the system can be controlled simultaneously. The performance of the proposed method is demonstrated via experimental studies.

Flexibility of links and joints affects dynamic behavior of manipulators. In this work, the vibration characteristics of a one-link carbon-fiber box manipulator with a rectangular cross-section and a [0/90/0/90] lay-up are studied to examine the effects of the link and joint flexibility. The theoretical results supported with experimental studies are presented to realize the mentioned examinations. An experimental system, which consists of a composite box manipulator driven by a geared servo motor and a wireless measurement system, is introduced. Some parameters of the driver are manually set in the experiments. Vibration tests of the composite manipulator are realized for the stationary and nonstationary cases. Experimental vibration responses are both evaluated for auto and manual tune modes of the servo driver. Theoretical results obtained via the finite element vibration analysis compared with the experimental results. The changes of the natural frequencies and damping properties are presented for the stationary and nonstationary cases. The experimental vibration responses of the composite box manipulator with various payloads match well with the theoretical ones by tuning servo motor parameters manually. (C) 2017 Elsevier Ltd. All rights reserved.

In this work, we provide a tracking controller formulation for dynamically positioned surface vessels with an asymmetric added mass terms that affects the overall system dynamics at the acceleration level. Specifically a novel continuous robust controller is proposed for surface vessels that in addition to unstructured uncertainties in its dynamics, contains added mass effects in its inertia matrix. The proposed controller compensates the overall system uncertainties while ensuring asymptotic tracking by utilizing the knowledge of the leading principal minors of the input gain matrix. Stability of the closed–loop system and asymptotic convergence are proven via Lyapunov based approaches. Simulation studies are also presented to illustrate the viability of the proposed method.

Tracking control of marine vessels in the presence of parametric uncertainty and additive periodic disturbances is considered. For optimal estimation of environmental forces, periodic disturbance estimation method inspired from Fourier series expansion have been applied. Stability of the closed–loop system and the convergence of the tracking error under the closed–loop operation are established via Lyapunov based arguments. Simulation studies are provided to support the theoretical results and the effectiveness of the proposed method. © 2020 Elsevier Ltd

An adaptive control design for dynamic positioning (DP) of unmanned surface vessels is addressed in this study. The control design is realized by taking actuator dynamics into account for obtaining a DP system where distribution of generalized forces to the actuators is considered. Owing to this approach DP system is made suitable for unmanned surface vessels having actuators equal to or more than number of generalized forces. All parameters of the surface vessel's body and actuator dynamics except thrust configuration matrix are assumed to be uncertain for the proposed control design. The parametric uncertainties are coped with adaptive compensation rules while the designed controller is equipped with a term that provides the robustness of the designed controller against disturbances including internal and external unmodeled effects. Backstepping control design approach is preferred for the control design process by considering the appropriateness of this approach for the system model of unmanned surface vessels include actuator dynamics. Theoretical proof of the designed controller is realized via Lyapunov–based arguments. Simulation studies where the efficiency of the designed controller is observed for both of aforementioned cases are conducted for the performance demonstration of the designed controller.

This work focuses on the robust attitude tracking control problem for a small– scaled unmanned helicopter where the actual system inputs, namely the elevator servo input, the aileron servo input and the rudder servo input, are used in the controller formulation. The design process is divided into two parts. Initially the problem is transformed into a second order system with an uncertain non–symmetric input gain matrix by utilizing some reasonable simplifications for the rotor model under the hovering flight conditions. Then a novel robust control methodology is utilized via a matrix decomposition method. The stability of the overall system is ensured by Lyapunov type analysis where asymptotic position tracking is ensured. Numerical simulation results are presented to demonstrate the efficiency of the proposed method.

In this work, we present a novel continuous robust controller for a class of multi-input/multi-output nonlinear systems that contains unstructured uncertainties in their drift vectors and input matrices. The proposed controller compensates uncertainties in the system dynamics and achieves asymptotic tracking while requiring only the knowledge of the sign of the leading principal minors of the input gain matrix. A Lyapunov-based argument backed up with an integral inequality is applied to prove the asymptotic stability of the closed-loop system. Simulation results are presented to illustrate the viability of the proposed method., Scientific and Technological Research Council of Turkey (113E147)

In this paper, the problem of accurate positioning of an unactuated surface vessel by using multiple uni-directional tugboats is investigated. Specifically a robust controller that ensures asymptotic position tracking is designed. The control design procedure is implemented in two steps: Initially by locating opposing tugboats to specific configurations, the overall problem is transformed into a second order system with an uncertain non-symmetric input gain matrix. Then via a matrix decomposition, a novel robust controller methodology is proposed. The stability of the overall system is ensured via rigorous stability analysis where asymptotic position tracking is ensured. Numerical simulation results are presented to demonstrate the efficiency of the proposed controller., Scientific and Technological Research Council of Turkey (113E147)

IEEE/RSJ International Conference on Intelligent Robots and Systems, IROS 2015; Congress Center Hamburg (CCH) Messeplatz Hamburg; Germany; 28 September 2015 through 2 October 2015, In this paper, a robust controller is designed to achieve accurate positioning of an unactuated surface vessel by using multiple unidirectional tugboats. After initially locating opposing tugboats to specific configurations, the control problem is transformed into a second order system with an uncertain non-symmetric input gain matrix. Upon applying a matrix decomposition, a robust controller is proposed. Detailed stability analysis ensured asymptotic tracking. Numerical simulation results demonstrate the efficiency of the proposed controller © 2015 IEEE.

Remotely operated vehicles equipped with a robotic manipulator are utilized in several underwater/deep sea applications. Control of these type of systems are mostly provided by obtaining the proper position for the end effector of robotic manipulator which constitutes the desired motion for remotely operated vehicle. This situation makes the control of robotic manipulators is really important subject for underwater applications. In this work, we study tracking control of a one degree-of-freedom rigid link in a cross flow. Systems operating at underwater (including this one) are hard to model accurately, and as a result their models include several uncertainties. To reject these modeling uncertainties and external ones, two robust controllers are proposed. Stability of the closed-loop system and the asymptotic convergence of the tracking error are proven mathematically. Numerical simulations are performed to demonstrate the viability of the proposed controller.

In this study, the input output relation of the twin rotor system which was constructed in our laboratory is obtained by using ANNs. When compared with the existing literature, main advantage of this modelling approach is that multi input multi output ANN structure is used preferred. As a result of this approach, the cross coupling effects, between the rotors and also between the outputs, are taken into consideration. Thus, we sincerely believe that the obtained input output model demonstrates a close behavior to the real system.

53rd IEEE Annual Conference on Decision and Control, CDC 2014; JW Marriott Hotel Los Angeles L.A.; United States; 15 December 2014 through 17 December 2014, This work concentrates on tracking control of dynamically positioned surface vessels with asymmetric added mass terms affecting the system model at the acceleration level. Specifically, we propose a novel continuous robust controller for surface vessels that, in addition to asymmetric added mass in its inertia matrix, contains unstructured uncertainties in all its system matrices. The proposed controller compensates the overall system uncertainties and ensures asymptotic tracking, while requiring only the knowledge of the sign of the leading principle minors of the input gain matrix. Lyapunov based approaches are applied in order to prove the stability of the closed-loop system and asymptotic convergence of the tracking error signal. © 2014 IEEE.

9th Asian Control Conference, ASCC 2013; Istanbul; Turkey; 23 June 2013 through 26 June 2013, In this work, we propose a new robust adaptive controller for a class of multi-input multi-output nonlinear systems subject to uncertain state delay. The proposed method is proven to yield semi-global asymptotic tracking despite the presence of additive input and output disturbances and parametric uncertainty in the system dynamics. An adaptive desired system compensation in conjunction with a continuous nonlinear integral feedback component is utilized in the design of the controller and Lyapunov-based techniques, are used to prove that the tracking error is asymptotically driven to zero. Numerical simulation results are presented to demonstrate the effectiveness of the proposed method. © 2013 IEEE.