Impact Control of Flexible Robots Using Sliding Mode Technique

1993 ◽  
Author(s):  
Eming Chen
Keyword(s):  
Motion Control ◽  
Dynamic Models ◽  
Sliding Mode ◽  
Contact Process ◽  
Control Technique ◽  
Work Piece ◽  
System Control ◽  
State Variables ◽  
Flexible Robot ◽  
Nonlinear System Control

Abstract In the flexible robot force control situations, if there exists a discontinuity between the robot tip sensor and the work-piece, the robot contact process becomes a nonlinear system control problem. The control tasks require the robot hand to switch from free motion control to contact motion control. The inevitable high impact force tends to let the system become unstable. The purpose of this paper is to investigate the control of the manipulator during this process. In this paper, dynamic models of the flexible link manipulator in both non-contacted and contacted modes are first derived. Due to the fact that the arm vibration shape functions are changed between the two modes, a transform matrix will be used to transform the controlled state variables, such as generalized position and velocity. A nonlinear sliding mode control technique has been implemented in an attempt to extinguish the chatter phenomenon and settle quickly to the desired setpoint.

Gain Scheduling Fuzzy Sliding Mode Strategy for Robotic Motion Control

2010 ◽  
Author(s):  
Shiuh-Jer Huang ◽  
Shian-Shin Wu ◽  
You-Min Huang
Keyword(s):  
Motion Control ◽  
Pulse Width Modulation ◽  
Fuzzy Controller ◽  
Sliding Mode ◽  
Gain Scheduling ◽  
Industrial Applications ◽  
System Control ◽  
Model Free ◽  
Robotic Motion ◽  
Fuzzy Sliding Mode

A Mitsubishi Movemaster RV-M2 robotic system control system is retrofitted into system-on-programmable-chip (SOPC) control structure. The software embedded in Altera Nios II field programmable gate array (FPGA) micro processor has the functions of using UART to communicate with PC, robotic inverse kinematics calculation, and robotic motion control. The digital hardware circuits with encoder decoding, limit switch detecting, pulse width modulation (PWM) generating functions are designed by using Verilog language. Since the robotic dynamics has complicate nonlinear behavior, it is impossible to design a MIMO model-based controller on micro-processor. Here a novel model-free fuzzy sliding mode control with gain scheduling strategy is developed to design the robotic joint controller. This fuzzy controller is easy to implement with 1D fuzzy control rule and less trial-and-error parameters searching work. The experimental results show that this intelligent controller can achieve quick transient response and precise steady state accuracy for industrial applications.

scholarly journals Dynamic Analysis and Motion Control of an Underactuated Unmanned Surface Vehicle (WL-II)

2017 ◽  
Vol 51 (6) ◽  
pp. 10-20 ◽  
Author(s):  
Ying Wu ◽  
Shengqiang Yang ◽  
Wenhui Li ◽  
Daliang Liu ◽  
Kang Hou
Keyword(s):  
Motion Control ◽  
Dynamic Models ◽  
Sliding Mode ◽  
State Equation ◽  
Superior Performance ◽  
Adaptive Sliding Mode Control ◽  
Sea Waves ◽  
Motion Platform ◽  
Unmanned Surface Vehicle ◽  
Heading Control

AbstractAn unmanned surface vehicle (USV) is a promising maritime motion platform used to accomplish hundreds of different tasks. This paper presents a design, improved dynamic modeling, and motion control of an underactuated USV, called WL-II. The detailed structure and component of WL-II are studied first. Then based on WL-II's structure, kinematic and dynamic models are built considering wind as well as sea waves; thus, a nonlinear dynamics model is deduced in the form of a state equation. The hardware and software systems of WL-II are introduced for its control mechanism. Then, the adaptive sliding mode control (SMC) algorithm for WL-II's motion is examined. The simulation and experimental results validate the superior performance of the proposed algorithm for WL-II's heading control to the regular SMC method. In this paper, improved dynamics, which consider more parameters (wind and sea waves), are proposed and reasonably simplified for computation. The adaptive SMC is used to control WL-II's motion to improve control precision and reduce response time.

Fault Tolerance of a Reconfigurable Tilt-Rotor Quadcopter Using Sliding Mode Control

2018 ◽  
Author(s):  
Siddharth Sridhar ◽  
Rumit Kumar ◽  
Kelly Cohen ◽  
Manish Kumar
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Control Technique ◽  
State Variables ◽  
Servo Motor ◽  
Tracking Errors ◽  
Tilt Rotor ◽  
Sliding Surfaces ◽  
Mode Control ◽  
Non Linear

Tilt-rotor quadcopters are a novel class of quadcopters with a servo motor attached on each arm that assist the quadcopter’s rotors to tilt to a desired angle thereby enabling thrust vectoring. Using these additional tilt angles, this type of a quadcopter can be used to achieve desired trajectories with faster maneuvering and can handle external disturbances better than a conventional quadcopter. In this paper, a non-linear controller has been designed using sliding mode technique for the pitch, roll, yaw motions and the servo motor tilt angles of the quadcopter. The dynamic model of the tilt-rotor quadcopter is presented, based on which sliding surfaces were designed to minimize the tracking errors. Using the control inputs derived from these sliding surfaces, the state variables converge to their desired values in finite-time. Further, the non-linear sliding surface coefficients are obtained by stability analysis. The robustness of this proposed sliding mode control technique is shown when a faulty motor scenario is introduced. The quadcopter transforms into a T-copter design upon motor failure thereby abetting the UAV to cope up with the instabilities experienced in yaw, pitch and roll axes and still completing the flight mission. The dynamics of the T-copter design and the derivation of the switching surface coefficients for this reconfigurable system are also presented.

scholarly journals Parameter Identification and The Multi-Switching Sliding Mode Combination Synchronization of Fractional Order Non-Identical Chaotic System Under Stochastic Disturbances

2021 ◽  
Author(s):  
Weiqiu Pan ◽  
Tianzeng Li ◽  
Yu Wang
Keyword(s):  
Fractional Order ◽  
Sliding Mode ◽  
Lyapunov Stability Theory ◽  
Control Technique ◽  
State Variables ◽  
Stochastic Disturbances ◽  
Unknown Parameters ◽  
Combination Synchronization ◽  
Special Cases ◽  
Drive Systems

Abstract This paper deals with the issue of the multi-switching sliding mode combination synchronization (MSSMCS) of fractional order (FO) chaotic systems with different structures and unknown parameters under double stochastic disturbances (SD) utilizing the multi-switching synchronization method. The stochastic disturbances are considered as nonlinear uncertainties and external disturbances. Our theoretical part is divided into two cases, namely, the dimension of the drive-response system are different (or same). Firstly, a FO sliding surface was established in term of fractional calculus. Secondly, depended on the FO Lyapunov stability theory, the adaptive control technology and sliding mode control technique, the multi-switching adaptive controllers (MSAC) and some suitable multi-switching adaptive updating laws (MSAUL) are designed, so that the state variables of the drive systems are synchronized with the different state variables of the response systems. Simultaneously, the unknown parameters are assessed and the upper bound of stochastic disturbances are examined. Selecting the suitable scale matrices, the multi-switching projection synchronization, multi-switching complete synchronization, and multi-switching anti-synchronization will become special cases of MSSMCS. Finally, examples are displayed to certify the usefulness and validity of the demonstrated scheme via MATLAB.

Non-Linear Sliding Mode Control of a Tilting-Rotor Quadcopter

2017 ◽  
Author(s):  
Siddharth Sridhar ◽  
Rumit Kumar ◽  
Mohammadreza Radmanesh ◽  
Manish Kumar
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Control Technique ◽  
State Variables ◽  
Tracking Errors ◽  
External Disturbances ◽  
Tilt Rotor ◽  
Sliding Surfaces ◽  
Mode Control ◽  
Non Linear

A non-linear control of a tilt-rotor quadcopter using sliding mode technique is presented in this paper. The tilt-rotor quadcopters are a novel class of quadcopters with a servo motor installed on each arm that enables the quadcopter’s rotors to tilt to a particular angle. Using these additional tilt angles, this type of a quadcopter can be used to achieve desired trajectories with faster maneuvering and can handle external disturbances better than a conventional quadcopter. In this paper, sliding mode control technique is utilized for the pitch, roll and yaw motions for the quadcopter while an independent PD controller provides the tilt angles to the servo motors. The dynamic model of the tilt-rotor quadcopter is presented, based on which sliding surfaces were designed to minimize the tracking errors. Using the control inputs derived from these sliding surfaces, the state variables converge to their desired values in finite-time. Further, the non-linear sliding surface coefficients are obtained by stability analysis. Numerical simulation results demonstrate the performance and robustness against disturbances of this proposed sliding mode control technique.

A nonlinear robust optimal controller for an active transfemoral prosthesis: An estimator-based state-dependent Riccati equation approach

2020 ◽  
pp. 095965182095988
Author(s):  
Anna Bavarsad ◽  
Ahmad Fakharian ◽  
Mohammad Bagher Menhaj
Keyword(s):  
Energy Consumption ◽  
Riccati Equation ◽  
Sliding Mode ◽  
Parametric Uncertainty ◽  
Tracking Performance ◽  
Control Technique ◽  
Optimal Controller ◽  
State Variables ◽  
State Dependent ◽  
Nonlinear Robust

This article presents an estimator-based nonlinear robust optimal controller for an active prosthetic leg for transfemoral amputees. The proposed controller is derived from a combination of the state-dependent Riccati equation technique to optimize the energy consumption of the robot/prosthesis system and the sliding mode control to reduce the effects of the model parametric uncertainties and ground reaction forces as nonparametric uncertainties. In addition, the integral state control technique is employed to improve tracking; also, to have a compromise between tracking performance and control signal chattering, the boundary layer is then used. In this study, the performance of both the controller and estimator in the presence of noise and disturbance is assessed for nominal system while ±40% parametric uncertainty with respect to saturation bounds of control signals is considered. The results of the simulation in this research with ±40% parametric uncertainty compared to a robust adaptive impedance control approach with the only variation of ±30% on the system parameters, show high performance of the proposed controllers in reducing energy consumption, good robustness, improved position tracking performance, and good performance in estimating state variables, even in the presence of large initial errors compared to the extended Kalman filter.

scholarly journals Robust Position Control of an Over-actuated Underwater Vehicle under Model Uncertainties and Ocean Current Effects Using Dynamic Sliding Mode Surface and Optimal Allocation Control

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 747
Author(s):  
Mai The Vu ◽  
Tat-Hien Le ◽  
Ha Le Nhu Ngoc Thanh ◽  
Tuan-Tu Huynh ◽  
Mien Van ◽  
...  
Keyword(s):  
Control System ◽  
Motion Control ◽  
Optimal Allocation ◽  
Position Control ◽  
Sliding Mode ◽  
Underwater Vehicle ◽  
Ocean Current ◽  
Model Uncertainties ◽  
Control Module ◽  
Dynamic Sliding Mode

Underwater vehicles (UVs) are subjected to various environmental disturbances due to ocean currents, propulsion systems, and un-modeled disturbances. In practice, it is very challenging to design a control system to maintain UVs stayed at the desired static position permanently under these conditions. Therefore, in this study, a nonlinear dynamics and robust positioning control of the over-actuated autonomous underwater vehicle (AUV) under the effects of ocean current and model uncertainties are presented. First, a motion equation of the over-actuated AUV under the effects of ocean current disturbances is established, and a trajectory generation of the over-actuated AUV heading angle is constructed based on the line of sight (LOS) algorithm. Second, a dynamic positioning (DP) control system based on motion control and an allocation control is proposed. For this, motion control of the over-actuated AUV based on the dynamic sliding mode control (DSMC) theory is adopted to improve the system robustness under the effects of the ocean current and model uncertainties. In addition, the stability of the system is proved based on Lyapunov criteria. Then, using the generalized forces generated from the motion control module, two different methods for optimal allocation control module: the least square (LS) method and quadratic programming (QP) method are developed to distribute a proper thrust to each thruster of the over-actuated AUV. Simulation studies are conducted to examine the effectiveness and robustness of the proposed DP controller. The results show that the proposed DP controller using the QP algorithm provides higher stability with smaller steady-state error and stronger robustness.

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