scholarly journals Sliding Mode Observer-based Control of Teleoperation System With Uncertain Dynamics and Kinematics

2021 ◽  
Author(s):  
Jianing Zhang ◽  
Fujie Wang ◽  
Guilin Wen
Keyword(s):  
Sliding Mode ◽  
Time Estimation ◽  
Joint Space ◽  
Estimation Errors ◽  
Uncertain Dynamics ◽  
Control Framework ◽  
End Effectors ◽  
Sliding Mode Observers ◽  
The Stability ◽  
Velocity Tracking

Abstract This paper concentrates on the control issue of nonlinear teleoperators in the presence of uncertain dynamics and kinematics. An observer-based control framework is introduced to compensate for the unfavorable effects arising from the uncertainties. The employment of the proposed sliding mode observers provide control system with the ability of finite-time estimation errors convergence, upon which, it is demonstrated that the bilateral teleoperators are stable and both of position and velocity tracking can be achieved with uncertain dynamics in joint space. Due to the practical requirement of driving the end-effectors to perform specific tasks, the control law which can ensure position coordination with uncertain dynamics and kinematics in task space is subsequently developed. The Lyapunov method is applied to demonstrate the stability of the closed-loop system. Simulation results are provided to testify the performance of the suggested algorithm.

scholarly journals Design and Comparative Study of Advanced Adaptive Control Schemes for Position Control of Electronic Throttle Valve

Information ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 65 ◽  
Author(s):  
Amjad Humaidi ◽  
Akram Hameed
Keyword(s):  
Adaptive Control ◽  
Position Control ◽  
Sliding Mode ◽  
Angular Position ◽  
Estimation Errors ◽  
Electronic Throttle ◽  
Control Schemes ◽  
Backstepping Controller ◽  
Matlab Package ◽  
The Stability

This paper investigates the performance of two different adaptive control schemes for controlling the angular position of an electronic throttle (ET) plate. The adaptive backstepping controller and adaptive sliding mode backstepping controller are the controllers under consideration. The control design based on these adaptive controllers is firstly addressed and the stability analysis of each controller has been presented and the convergence of both position and estimation errors for both controllers have been proved. A comparison study of the performance of both controllers has been conducted in terms of system transient characteristics and the behavior of their associated adaptive gain. The simulation has been implemented within the environment of the MATLAB package.

scholarly journals Synchronization Full-Order Terminal Sliding Mode Control for an Uncertain 3-DOF Planar Parallel Robotic Manipulator

2019 ◽  
Vol 9 (9) ◽  
pp. 1756 ◽  
Author(s):  
Doan ◽  
Le ◽  
Vo
Keyword(s):  
Sliding Mode Control ◽  
High Performance ◽  
Sliding Mode ◽  
Robotic Manipulator ◽  
Continuous Control ◽  
Terminal Sliding Mode Control ◽  
Terminal Sliding Mode ◽  
Mode Control ◽  
Uncertain Dynamics ◽  
The Stability

The control of a parallel robotic manipulator with uncertain dynamics is a noteworthy challenge due to the complicated dynamic model; multi-closed-loop chains; and singularities. This study develops a Synchronization Full-Order Terminal Sliding Mode Control (S-FOTSMC) for a 3-DOF planar parallel robotic manipulator with uncertain dynamics. First, to achieve faster convergence of position error and synchronization error variables with minimum values at the same time, a Synchronization Full-Order Terminal Sliding Mode Surface (S-FOTSMS) is constructed in the cross-coupling error’s state space. Next; an integral of the switching control term is applied; that means, a continuous control term is extended for rejecting the effects of chattering. Finally, an SFOTSMC is designed to guarantee that sliding mode motion will occur. Consequently, the stability and the robustness of the proposed method are secured with high-performance irrespective of the influences of uncertain terms in the robot system. The simulation performances show the effectiveness of our proposed system for position tracking control of a 3-DOF planar parallel robotic manipulator.

Analysis of Sliding Mode Observers Using a Novel Time-Averaged Lyapunov Function

2017 ◽  
Author(s):  
Sagar Mehta ◽  
Krishna Vijayaraghavan
Keyword(s):  
Lyapunov Function ◽  
Gaussian Noise ◽  
Sliding Mode ◽  
Sliding Mode Observer ◽  
Sensor Noise ◽  
Model Uncertainties ◽  
Quadratic Lyapunov Function ◽  
Simulation Results ◽  
Sliding Mode Observers ◽  
The Stability

Sliding mode observers are known to be robust to model uncertainties. However, sliding mode observers have not been well analyzed in the presence of Gaussian disturbances and no previous results exist for a pure sliding mode observer in the presence of sensor noise. A traditional quadratic Lyapunov function that is used to determine the stability of sliding mode observers, fails for noisy systems. Hence this paper introduces a novel Lyapunov candidate function termed the time averaged Lyapunov (TAL) function to analyze the stability of noisy systems. The TAL specifically examines the effect of the Gaussian noise on a sliding mode observer. Using this TAL function, the paper demonstrates that Gaussian sensor noise does not affect the stability or chatter of the observer. Further, the covariance of the noise only affects the convergence rate of the observer. Simulation results are reported to demonstrate the effectiveness of the proposed approach on a Linear system.

scholarly journals Delay compensation based controller for rotary electrohydraulic servo system

2021 ◽  
Author(s):  
Zakarya Omar ◽  
Xingsong Wang ◽  
Khalid Hussain ◽  
Mingxing Yang
Keyword(s):  
High Frequency ◽  
Dead Time ◽  
Sliding Mode ◽  
Servo System ◽  
Smith Predictor ◽  
Delay Compensation ◽  
Mechanical Parts ◽  
System Output ◽  
Electrohydraulic Servo System ◽  
The Stability

AbstractThe typical power-assisted hip exoskeleton utilizes rotary electrohydraulic actuator to carry out strength augmentation required by many tasks such as running, lifting loads and climbing up. Nevertheless, it is difficult to precisely control it due to the inherent nonlinearity and the large dead time occurring in the output. The presence of large dead time fires undesired fluctuation in the system output. Furthermore, the risk of damaging the mechanical parts of the actuator increases as these high-frequency underdamped oscillations surpass the natural frequency of the system. In addition, system closed-loop performance is degraded and the stability of the system is unenviably affected. In this work, a Sliding Mode Controller enhanced by a Smith predictor (SMC-SP) scheme that counts for the output delay and the inherent parameter nonlinearities is presented. SMC is utilized for its robustness against the uncertainty and nonlinearity of the servo system parameters whereas the Smith predictor alleviates the dead time of the system’s states. Experimental results show smoother response of the proposed scheme regardless of the amount of the existing dead time. The response trajectories of the proposed SMC-SP versus other control methods were compared for a different predefined dead time.

scholarly journals Observer-based adaptive neural network backstepping sliding mode control for switched fractional order uncertain nonlinear systems with unmeasured states

2021 ◽  
pp. 002029402110211
Author(s):  
Tao Chen ◽  
Damin Cao ◽  
Jiaxin Yuan ◽  
Hui Yang
Keyword(s):  
Neural Network ◽  
Nonlinear Systems ◽  
Sliding Mode Control ◽  
Fractional Order ◽  
Sliding Mode ◽  
Tracking Error ◽  
Adaptive Neural Network ◽  
Dynamic Surface ◽  
Mode Control ◽  
The Stability

This paper proposes an observer-based adaptive neural network backstepping sliding mode controller to ensure the stability of switched fractional order strict-feedback nonlinear systems in the presence of arbitrary switchings and unmeasured states. To avoid “explosion of complexity” and obtain fractional derivatives for virtual control functions continuously, the fractional order dynamic surface control (DSC) technology is introduced into the controller. An observer is used for states estimation of the fractional order systems. The sliding mode control technology is introduced to enhance robustness. The unknown nonlinear functions and uncertain disturbances are approximated by the radial basis function neural networks (RBFNNs). The stability of system is ensured by the constructed Lyapunov functions. The fractional adaptive laws are proposed to update uncertain parameters. The proposed controller can ensure convergence of the tracking error and all the states remain bounded in the closed-loop systems. Lastly, the feasibility of the proposed control method is proved by giving two examples.

scholarly journals Sliding Mode Control and Geometrization Conjecture in Seismic Response

Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 353
Author(s):  
Ligia Munteanu ◽  
Dan Dumitriu ◽  
Cornel Brisan ◽  
Mircea Bara ◽  
Veturia Chiroiu ◽  
...  
Keyword(s):  
Sliding Mode Control ◽  
Ricci Flow ◽  
Lyapunov Functions ◽  
Seismic Waves ◽  
Sliding Mode ◽  
Flow Process ◽  
Mode Control ◽  
Finite Period ◽  
The Stability ◽  
Story Building

The purpose of this paper is to study the sliding mode control as a Ricci flow process in the context of a three-story building structure subjected to seismic waves. The stability conditions result from two Lyapunov functions, the first associated with slipping in a finite period of time and the second with convergence of trajectories to the desired state. Simulation results show that the Ricci flow control leads to minimization of the displacements of the floors.

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