scholarly journals Visual Based Control Scheme for a Robotic Manipulator with Duality of Task-space Information and Friction Compensation

2014 ◽  
Vol 42 ◽  
pp. 279-286
Author(s):  
Zool H. Ismail ◽  
Ahmad A’.M. Faudzi ◽  
Matthew W. Dunnigan
Keyword(s):  
Robotic Manipulator ◽  
Friction Compensation ◽  
Task Space ◽  
Control Scheme

Adaptive path-constrained control of a robotic manipulator in a task space

Robotica ◽  
2006 ◽  
Vol 25 (1) ◽  
pp. 103-112 ◽  
Author(s):  
Mirosław Galicki
Keyword(s):  
Degrees Of Freedom ◽  
Path Following ◽  
Lyapunov Stability Theory ◽  
Robotic Manipulator ◽  
Task Space ◽  
End Effector ◽  
State Dependent ◽  
Control Scheme ◽  
Robot Task ◽  
Three Degrees Of Freedom

This study addresses the problem of adaptive controlling of both a nonredundant and a redundant robotic manipulator with state-dependent constraints. The task of the robot is to follow a prescribed geometric path given in the task space, by the end-effector. The aforementioned robot task has been solved on the basis of the Lyapunov stability theory, which is used to derive the control scheme. A new adaptive Jacobian controller is proposed in the paper for the path following of the robot, with both uncertain kinematics and dynamics. The numerical simulation results carried out for a planar redundant three-DOF (three degrees of freedom) manipulator whose end-effector follows a prescribed geometric path given in a two-dimensional (2D) task space, illustrate the trajectory performance of the proposed control scheme.

Task-Space Control Design and Performance Evaluation for a 6DOF Stewart Nanoscale Platform

2008 ◽  
Author(s):  
Chun-Chung Li ◽  
Yung Ting ◽  
Yi-Hung Liu ◽  
Yi-Da Lee ◽  
Chun-Wei Chiu
Keyword(s):  
Feedback Control ◽  
Hybrid Control ◽  
Feedforward Control ◽  
Feedback Controller ◽  
Test Method ◽  
Computation Method ◽  
Task Space ◽  
Force Output ◽  
End Effector ◽  
Control Scheme

A 6DOF Stewart platform using piezoelectric actuators for nanoscale positioning objective is designed. A measurement method that can directly measure the pose (position and orientation) of the end-effector is developed so that task-space on-line control is practicable. The design of a sensor holder for sensor employment, a cuboid with referenced measure points, and the computation method for obtaining the end-effector parameters is introduced. A control scheme combining feedforward and feedback is proposed. The inverse model of a hysteresis model derived by using a dynamic Preisach method is used for the feedforward control. Hybrid control to maintain both the positioning and force output for nano-cutting and nano-assembly applications is designed for the feedback controller. The optimal gain of the feedback controller is searched by using relay feedback test method and genetic algorithm. In experiment, conditions with/without external load employed with feedforward, feedback, and feedforward with feedback control schemes respectively are carried out. Performance of each control scheme verifies the capability of achieving nanoscale precision. The combined feedforward and feedback control scheme is superior to the others for gaining better precision.

Fuzzy Sliding Mode Control of Robotic Manipulators With Kinematic and Dynamic Uncertainties

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Haitao Liu ◽  
Tie Zhang
Keyword(s):  
Fuzzy Logic ◽  
Sliding Mode Control ◽  
Degrees Of Freedom ◽  
Sliding Mode ◽  
Robotic Manipulator ◽  
Mode Control ◽  
Control Scheme ◽  
Adaptive Fuzzy Logic ◽  
Fuzzy Sliding Mode ◽  
Dynamic Uncertainties

Sliding mode control is a very attractive control scheme with strong robustness to structured and unstructured uncertainties as well as to external disturbances. In this paper, a robust fuzzy sliding mode controller, which is combined with an adaptive fuzzy logic system, is proposed to improve the control performance of the robotic manipulator with kinematic and dynamic uncertainties. In this controller, the sliding mode control is employed to improve the control accuracy and the robustness of the robotic manipulator, and the fuzzy logic control is adopted to approximate various uncertainties and to eliminate the chattering without the help of any prior knowledge of system uncertainties. The effectiveness of the proposed controller is then verified by the simulations on a 2-DOF (degrees of freedom) robotic manipulator and the experiments on an SCARA robot with four degrees of freedom. Simulated and experimental results indicate that the proposed controller is effective in the robust tracking of the robotic manipulator with kinematic and dynamic uncertainties.

scholarly journals Fault-tolerant scheme for robotic manipulator—Nonlinear robust back-stepping control with friction compensation

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256491
Author(s):  
Khurram Ali ◽  
Adeel Mehmood ◽  
Jamshed Iqbal
Keyword(s):  
Hybrid Control ◽  
Autonomous Robots ◽  
Fault Tolerant ◽  
Robot Manipulator ◽  
Robotic Manipulator ◽  
Friction Model ◽  
Fault Estimation ◽  
Friction Compensation ◽  
Control Law ◽  
Control Approach

Emerging applications of autonomous robots requiring stability and reliability cannot afford component failure to achieve operational objectives. Hence, identification and countermeasure of a fault is of utmost importance in mechatronics community. This research proposes a Fault-tolerant control (FTC) for a robot manipulator, which is based on a hybrid control scheme that uses an observer as well as a hardware redundancy strategy to improve the performance and efficiency in the presence of actuator and sensor faults. Considering a five Degree of Freedom (DoF) robotic manipulator, a dynamic LuGre friction model is derived which forms the basis for design of control law. For actuator’s and sensor’s FTC, an adaptive back-stepping methodology is used for fault estimation and the nominal control law is used for the controller reconfiguration and observer is designed. Fault detection is accomplished by comparing the actual and observed states, pursued by fault tolerant method using redundant sensors. The results affirm the effectiveness of the proposed FTC strategy with model-based friction compensation. Improved tracking performance as well robustness in the presence of friction and fault demonstrate the efficiency of the proposed control approach.

scholarly journals Terminal Sliding-Mode Control of Uncertain Robotic Manipulator System with Predefined Convergence Time

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Yang Wang ◽  
Mingshu Chen ◽  
Yu Song
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Design Method ◽  
Robotic Manipulator ◽  
Convergence Time ◽  
Terminal Sliding Mode Control ◽  
Tracking Errors ◽  
Terminal Sliding Mode ◽  
Mode Control ◽  
Control Scheme

This paper concentrates on the predefined-time trajectory tracking for an uncertain robotic manipulator system. First, a modified predefined-time control (PTC) algorithm is proposed. Subsequently, with the help of proposed modified PTC algorithm and the nonsingular design method of terminal sliding mode, a novel nonsingular terminal sliding-mode control (NTSMC) scheme is proposed for ensuring the predefined-time convergence of tracking errors. The advantages of the newly proposed control scheme are as follows. (i) Unlike the conventional predefined-time sliding-mode control (SMC) which only guarantees the predefined-time convergence of sliding-mode surface, the proposed scheme can guarantee the predefined-time convergence of tracking errors. (ii) Compared with the conventional PTC algorithm, the proposed modified PTC algorithm can reduce the initial control peaking and enhance the precision of convergence time. The performance and effectiveness of the proposed control scheme are illustrated by comparing with the existing methods.

A New Probabilistic Method for the Performance Evaluation of Manipulators: Part II — Application to Task Placement

1989 ◽  
Author(s):  
J. Rastegar ◽  
J. R. Singh
Keyword(s):  
Performance Evaluation ◽  
Probabilistic Method ◽  
Robotic Manipulator ◽  
Optimality Criteria ◽  
Optimal Placement ◽  
Arbitrary Form ◽  
Complex Task ◽  
Task Space ◽  
Force Transmission ◽  
Task Placement

Abstract A probabilistic method for optimal placement of a prescribed task space in the workspace of a robotic manipulator is presented. Velocity and force transmission (alone and in combination) are used as optimality criteria. Complex task space and manipulator workspace geometries are readily handled. The distribution of the tasks within the task space, and the velocity and force transmission requirements may assume any arbitrary form. The method is extremely simple, does not require inverse calculations, is numerical in nature, and is readily implemented on computers. In many cases, the best location of the task space within the manipulator workspace can be visually ascertained. Minimal analytical formulations are required. Several examples are presented.

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