A Repetitive Learning Method Based on Sliding Mode for Robot Control With Actuator Saturation

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Huihui Tian ◽  
Yuxin Su
Keyword(s):  
Control Method ◽  
Actuator Saturation ◽  
Sliding Mode ◽  
Direct Method ◽  
Actuator Failure ◽  
Asymptotic Tracking ◽  
Repetitive Learning ◽  
Precision Tracking ◽  
Improved Performance ◽  
Three Degree Of Freedom

This paper proposes a sliding mode based repetitive learning control method for high-precision tracking of robot manipulators with actuator saturation. Advantages of the proposed control include the absence of model parameter in the control law formulation and the ability to remove the possibility of actuator failure due to excessive torque input levels. Lyapunov's direct method is employed to prove semiglobal asymptotic tracking. Simulation results on a three degree-of-freedom (3DOF) robot illustrate the effectiveness and improved performance of the proposed scheme.

scholarly journals A non-integer sliding mode controller to stabilize fractional-order nonlinear systems

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Ahmadreza Haghighi ◽  
Roveida Ziaratban
Keyword(s):  
Fractional Order ◽  
Chaotic Systems ◽  
Control Method ◽  
Controller Design ◽  
Nonlinear Dynamical Systems ◽  
Sliding Mode ◽  
Slip Surface ◽  
Direct Method ◽  
Distributed Model ◽  
Sliding Mode Controller

Abstract In this study, we examine the stabilization of fractional-order chaotic nonlinear dynamical systems with model uncertainties and external disturbances. We used the sliding mode controller by a new approach for controlling and stabilization of these systems. In this research, we replaced a continuous function with the sign function in the controller design and the sliding surface to suppress chattering and undesirable vibration effects. The advantages of the proposed control method are rapid convergence to the equilibrium point, the absence of chattering and unwanted oscillations, high resistance to uncertainties, and the possibility of applying this method to most fractional order chaotic systems. We applied the direct method of Lyapunov stability theory and the frequency distributed model to prove the stability of the slip surface and closed loop system. Finally, we simulated this method on two commonly used and practical chaotic systems and presented the results.

Study on the control method about improving piezoelectric actuated photoelectric precision tracking system

2020 ◽  
pp. 1-12
Author(s):  
Zongkai Liu ◽  
Yuming Liu ◽  
Yuheng Zhang
Keyword(s):  
Control Method ◽  
Sliding Mode ◽  
Rbf Neural Network ◽  
Tracking System ◽  
Large Angle ◽  
Response Speed ◽  
Field Of View ◽  
Small Range ◽  
Adaptive Backstepping ◽  
Precision Tracking

Fast steering mirrors (FSM) driven by Piezoelectric transducer (PZT) are widely used in various precision stable tracking systems. Aiming to counteract the hysteresis and non-linear interference in PZT, this work applies a radial basis function (RBF) neural network to approximate its nonlinearity. Adaptive backstepping sliding mode (ABSM) controller combinewith a sliding mode control method and backstepping control is designed. Combining the characteristics of PZT and voice coil motors (VCM), the FSM driven by VCM is designed as the power sub-system to ensure that the large-angle deflection of the FSM can match a wider field of view. The FSM driven by PZT is designed as a correction sub-system, which can adjust the system error within a small range. Finally, the power sub-system and the correction sub-system are combined into a two-level precision tracking system. The simulation results show that the maximum steady-state error of the system is about 15 μrad, and the root mean square error is about 10 μrad. Compared with the traditional PI controller, the error is reduced by about 75%, the response speed is up to 10 ms, and the output is smooth without some serious viberation.

A Repetitive Learning Method Based on Sliding Mode for Robot Control

1999 ◽  
Vol 122 (1) ◽  
pp. 40-48 ◽  
Author(s):  
T. S. Liu ◽  
W. S. Lee
Keyword(s):  
Sliding Mode Control ◽  
Control Method ◽  
Sliding Mode ◽  
Learning Algorithm ◽  
Learning Control ◽  
Integral Transforms ◽  
Robot Dynamics ◽  
Joint Torques ◽  
Mode Control ◽  
Repetitive Learning

In order to make a robot precisely track desired periodic trajectories, this work proposes a sliding mode based repetitive learning control method, which incorporates characteristics of sliding mode control into repetitive learning control. The learning algorithm not only utilizes shape functions to approximate influence functions in integral transforms, but also estimates inverse dynamics functions based on integral transforms. It learns at each sampling instant the desired input joint torques without prior knowledge of the robot dynamics. To carry out sliding mode control, a reaching law method is employed, which is robust against model uncertainties and external disturbances. Experiments are performed to validate the proposed method. [S0022-0434(00)02001-3]

scholarly journals Fault-Tolerant Aircraft Control Based on Self-Constructing Fuzzy Neural Network for Quadcopter

2021 ◽  
Vol 15 (1) ◽  
pp. 109-122
Author(s):  
Dejie Li ◽  
◽  
Pu Yang ◽  
Zhangxi Liu ◽  
Zixin Wang ◽  
...  
Keyword(s):  
Neural Network ◽  
Fuzzy Neural Network ◽  
Control Method ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Failure Model ◽  
Aircraft Control ◽  
Actuator Failure ◽  
Fuzzy Neural ◽  
The Stability

This paper proposes a fault-tolerant aircraft control method based on a self-constructed fuzzy neural network for quadcopters with multiple actuator faults. We first introduce the actuator failure model and the model uncertainty. Subsequently, we establish a framework for a self-constructed fuzzy neural network observer with an adaptive rate to obtain the estimated value of the nonlinear term of the module uncertainty. We also design a multivariable sliding mode fault-tolerant controller to ensure the stability of the aircraft under this fault condition. Finally, we conduct experiments using the Pixhawk 4 flight controller installed on the QBall-X4 UAV experimental platform, such that the use of the flight controller’s fault coprocessor and redundant sensor design reduces the crash that occurs during the debugging of the control algorithm. Compared to the existing intelligent fault-tolerant control technology, our proposed method employs fewer fuzzy rules, and the number of these rules can be adaptively adjusted when the system model changes. In the experimental test, the aircraft was still able to fly stably under multi-actuator failure and interference conditions, thereby proving the stability of the proposed controller.

scholarly journals Stabilization of a Class of Nonlinear Underactuated Robotic Systems through Nonsingular Fast Terminal Sliding Mode Control

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Yaobin Song ◽  
Hui Li ◽  
Xiaoling Shi
Keyword(s):  
Sliding Mode Control ◽  
Control Method ◽  
Sliding Mode ◽  
Direct Method ◽  
Robotic Systems ◽  
Control Technique ◽  
Terminal Sliding Mode Control ◽  
Terminal Sliding Mode ◽  
Mode Control ◽  
Fast Terminal Sliding Mode

To facilitate the stabilization of nonlinear underactuated robotic systems under perturbation, a novel nonsingular fast terminal sliding mode control method is proposed. Based on the system transformation into an integrator chain, the combination of twisting-like algorithm and a nonsingular fast terminal sliding mode control technique is employed to achieve the stabilization of the studied systems, which can drive the robot states (joint positions and velocities) to the desired region and then maintain the system at the equilibrium point in finite time. The robustness of the proposed method is validated by the Lyapunov direct method. Finally, numerical simulation results further demonstrate that the proposed method has better performance on the convergent speed of the system state (robot joint positions and velocities) than state-of-the-art methods, especially for the underactuated joints.

Faster Positioning of One Degree-of-Freedom Mechanical Systems With Friction and Actuator Saturation

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Chunhong Zheng ◽  
Yuxin Su ◽  
Paolo Mercorelli
Keyword(s):  
Actuator Saturation ◽  
Direct Method ◽  
Mechanical Systems ◽  
Nonlinear Function ◽  
Degree Of Freedom ◽  
Friction Compensation ◽  
Control Law ◽  
Pd Control ◽  
Improved Performance ◽  
Bounded Input

This paper concerns with faster positioning of one degree-of-freedom (1DOF) mechanical systems with friction and actuator saturation. A very simple but quite effective saturated relay proportional-derivative (PD) control is proposed. The proposed control is conceived within the framework of nonlinear PD methodology. It is accomplished by adding a relay position error for friction compensation to the saturated PD control law. For faster transient with bounded input, a saturated nonlinear function is introduced. Lyapunov's direct method is employed to prove global asymptotic positioning. The appealing advantages of the proposed control are that it is fairly easy to construct without involvement of any modeling parameter and has the ability to avoid the actuator saturation. Numerical example and experiments demonstrate the effectiveness and improved performance of the proposed approach.

Observer-based robust platoon formation control of electrically driven car-like mobile robots under collision avoidance and connectivity maintenance with a prescribed performance

2021 ◽  
pp. 107754632110191
Author(s):  
Omid Elhaki ◽  
Khoshnam Shojaei
Keyword(s):  
Mobile Robots ◽  
Collision Avoidance ◽  
Formation Control ◽  
Control Method ◽  
Actuator Saturation ◽  
Direct Method ◽  
Tracking System ◽  
Performance Bound ◽  
Dynamic Surface ◽  
Prescribed Performance

This study intends to address the platoon formation control problem of a team of N electrically driven underactuated autonomous car-like mobile robots. A platoon controller is proposed by using the relative distance and angle between each two successive robots in the platoon. A high-gain observer is also used to leave out velocity sensors to reduce the cost of the implementation/maintenance and the weight of the robots. Then, the dynamic surface control method is used to prevent complexity of the controller design. Next, by utilizing the prescribed performance bound method, predetermined desired transient and steady-state behavior of the tracking formation errors, robots connectivity preservation, and their collision avoidance are guaranteed as well as singularity avoidance. Adaptive neural networks and adaptive robust controllers are used to improve the tracking performance in the presence of parametric and nonparametric uncertainties, unmodeled dynamics, actuator saturation nonlinearity, and unwanted external disturbances including exogenous forces and torques, friction, and vibration. The Lyapunov direct method proves that all signals of the closed-loop control system are uniformly ultimately bounded. Finally, simulation results are demonstrated to show the superiority of the proposed convoy tracking system.

Robust time-varying output tracking control in the presence of actuator saturation

2016 ◽  
Vol 40 (1) ◽  
pp. 61-70 ◽  
Author(s):  
Tahereh Binazadeh ◽  
Majid Bahmani
Keyword(s):  
Control Method ◽  
Actuator Saturation ◽  
Sliding Mode ◽  
Reference Signal ◽  
Time Varying ◽  
Nonlinear Feedback ◽  
Composite Nonlinear Feedback ◽  
Output Tracking ◽  
Output Tracking Control ◽  
Feedback Control Method

This paper considers the problem of output tracking of a time-varying reference signal for a class of uncertain systems in the presence of actuator saturation. To achieve this capability, a new controller is proposed by robustifying the generalized composite nonlinear feedback control method with the integral sliding mode controller. Since the proposed controller may be saturated, a precise analysis is done to show its robust performance despite the presence of actuator saturation and model uncertainties. For this purpose, a theorem is given and proved that guarantees the robust output tracking via the proposed control law for three different cases of the saturation function and it is shown that even if the control signal is saturated, the proposed controller achieves output tracking of the time-varying reference signal. Also, in order to show the applicability of the proposed controller, it is applied on two practical systems, the XY-table and inertia wheel inverted pendulum. Computer simulations verify the theoretical results and also display the effective performance of the proposed controller.

scholarly journals Adaptive Fixed-Time Nonsingular Terminal Sliding Mode Attitude Tracking Control for Spacecraft with Actuator Saturations and Faults

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Zhiguo Han ◽  
Minghao Wang ◽  
Xunliang Yan ◽  
Hang Qian
Keyword(s):  
Control Method ◽  
Actuator Saturation ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Fixed Time ◽  
External Disturbances ◽  
Terminal Sliding Mode ◽  
Nonsingular Terminal Sliding Mode ◽  
Attitude Tracking ◽  
Attitude Tracking Control

This paper focuses on the potential actuator failures of spacecraft in practical engineering applications. Aiming at the shortcomings and deficiencies in the existing attitude fault-tolerant control system design, combined with the current research status of attitude fault-tolerant control technology, we carry out high-precision, fast-convergent attitude tracking algorithms. Based on the adaptive nonsingular terminal sliding mode control theory, we design a kind of fixed-time convergence control method. This method solves the problems of actuator faults, actuator saturation, external disturbances, and inertia uncertainties. The control method includes control law design and controller design. The designed fixed-time adaptive nonsingular terminal sliding mode control law is applicable to the development of fixed-time fault-tolerant attitude tracking controller with multiple constraints. The designed controller considers the saturation of the actuator output torque so that the spacecraft can operate within the saturation magnitude without on-line fault estimation. Lyapunov stability analysis shows that under multiple constraints such as actuator saturation, external disturbances, and inertia uncertainties, the controller has fast convergence and has good fault tolerance to actuator fault. The numerical simulation shows that the controller has good performance and low-energy consumption in attitude tracking control.

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