A Single Parameter-Based Adaptive Approach to Robotic Manipulators With Finite Time Convergence and Actuator Fault

Shuang Zhang,Guang Li,Wei He,Linghuan Kong,Pengxin Yang

doi:10.1109/access.2020.2966639

Abstract

In this paper, a novel single-parameter adaptive finite time fault tolerant control (FTC) scheme is developed for an n-link robotic system with actuator fault, disturbances, system parameter uncertainties and saturation constraints. First, a finite time passive FTC (PFTC) is designed. Then, an improved control strategy called active FTC (AFTC) based on single-parameter adaptive method is studied. In this control scheme, a nonsingular fast terminal sliding mode (NFTSM) control is employed for the purpose of enhancing the robustness of the robotic system. The single-parameter adaptive method is employed to avoid obtaining the values of actuator fault, disturbances and system parameter uncertainties which reduces the complexity of the control design and the time required for online calculations. Finally, the effectiveness of the proposed single-parameter adaptive finite time AFTC scheme is verified by the simulation results.

Highlights

With the arrival of the artificial intelligence era, robots are having an increasingly profound impact on the lifestyle and the production patterns of the human society
Depending on whether a fault diagnosis has been made or not, fault tolerant control (FTC) technology is divided into passive FTC (PFTC) technology and active FTC (AFTC) technology
AFTC the controller (29) can make the robotic system converge in finite time under the condition of actuator fault, input saturation, and all uncertainties, it is difficult to get the upper bound value

Summary

INTRODUCTION

With the arrival of the artificial intelligence era, robots are having an increasingly profound impact on the lifestyle and the production patterns of the human society. For robotic systems with input saturation, actuator fault, external disturbances and uncertainties in system parameters, this paper combines adaptive methods with NFTSMC. (1) Parameter uncertainties in the system, disturbances, actuator fault, and input saturation are integrated into a framework and the upper bound for the design of the controller is estimated using a single-parameter adaptive method. B. AFTC the controller (29) can make the robotic system converge in finite time under the condition of actuator fault, input saturation, and all uncertainties, it is difficult to get the upper bound value. AFTC the controller (29) can make the robotic system converge in finite time under the condition of actuator fault, input saturation, and all uncertainties, it is difficult to get the upper bound value To solve this problem, we employ the adaptive scheme to estimate the value. The total convergence time t is expressed as t ≤ t1 + t2

SIMULATION

Findings

CONCLUSION