A Novel Fault-Tolerant Control Method for Robot Manipulators Based on Non-Singular Fast Terminal Sliding Mode Control and Disturbance Observer

Abstract

In this study, a novel Fault-Tolerant Control Methodology (FTCM) is developed for robot manipulators. First, to overcome singularity glitch and to enhance convergence time of conventional Terminal Sliding Mode Control (TSMC), a new Fast Terminal Sliding Mode Surface (FTSMS) is constructed. Next, to reduce the computation complexity and to provide requirements about undefined nonlinear functions for the control system, a Disturbance Observer (DO) to estimate uncertain dynamics, external disturbances, or faults. Besides, a Super-Twisting Reaching Control Law (STRCL) is designed to compensate for the estimated error of disturbance observer with chattering rejection. Final, a novel, robust, FTCM was developed for robot manipulators to obtain the stability goal of the system, to reach the prescribed performance, and to overcome the effects of disturbances, nonlinearities, or faults. Accordingly, the proposed FTCM has remarkable features, such as fast convergence speeds, robust precision, high tracking performance, significant alleviation of chattering behavior, and finite-time convergence. The position tracking computer simulations were implemented to exhibit the effectiveness and feasibility of the suggested FTCM compared with other control algorithms.

Sliding Mode Control with Application to Fault-Tolerant Control: Assessment and Open Problems

“…The finite-time synchronization technique makes both the joint position error and the synchronization error converge to zero, in finite time, while considering the robot singularity avoidance problem. Fault tolerance against robot manipulator faults with singularity avoidance is considered in [96] using a combination of STA, disturbance estimation, and non-singular fast TSM controller. According to the authors, the proposed solution has the advantages of reducing the transient performance, convergence in short time, and rejection of the chattering phenomenon.…”

Robust Fault-Tolerant Control of an Electro-Hydraulic Actuator With a Novel Nonlinear Unknown Input Observer

“…Therefore, the FDI and FTC developments are important to ensure the safety and reliability of the hydraulic control system, especially, in the presence of concerned faults and mismatched disturbances. This approach combines the FTC technique-assisted the fault information of FDI, called active FTC [46], [47]. Hence, to overcome these aforementioned drawbacks, in this work, an active FTC is proposed for an electro-hydraulic rotary actuator (EHRA) based on a novel NUIO and adaptive control laws.…”

A New Active Fault Tolerant Control System: Predictive Online Fault Estimation

“…In recent decades, many efforts has been made to design FTC systems to guarantee the desirable performance for the process in the presence of components malfunction and dynamic perturbations. A FTC system is designed to automatically compensate the system faults and, to ensure the stability and satisfactory level of overall performance in both fault free and faulty condition [1]- [3]. The design techniques of FTC systems can be classified in two cases: passive approach (PFTC) and active approach (AFTC).…”