Finite Time Fault Tolerant Control for Robot Manipulators Using Time Delay Estimation and Continuous Nonsingular Fast Terminal Sliding Mode Control

Abstract

In this paper, a novel finite time fault tolerant control (FTC) is proposed for uncertain robot manipulators with actuator faults. First, a finite time passive FTC (PFTC) based on a robust nonsingular fast terminal sliding mode control (NFTSMC) is investigated. Be analyzed for addressing the disadvantages of the PFTC, an AFTC are then investigated by combining NFTSMC with a simple fault diagnosis scheme. In this scheme, an online fault estimation algorithm based on time delay estimation (TDE) is proposed to approximate actuator faults. The estimated fault information is used to detect, isolate, and accommodate the effect of the faults in the system. Then, a robust AFTC law is established by combining the obtained fault information and a robust NFTSMC. Finally, a high-order sliding mode (HOSM) control based on super-twisting algorithm is employed to eliminate the chattering. In comparison to the PFTC and other state-of-the-art approaches, the proposed AFTC scheme possess several advantages such as high precision, strong robustness, no singularity, less chattering, and fast finite-time convergence due to the combined NFTSMC and HOSM control, and requires no prior knowledge of the fault due to TDE-based fault estimation. Finally, simulation results are obtained to verify the effectiveness of the proposed strategy.

Robust Composite High-Order Super-Twisting Sliding Mode Control of Robot Manipulators

“…The stability of higher-order super-twisting sliding mode controller for any match uncertainties has been proved by Kamal and Bandyopadhyay in [45]. The authors in [32,40,41] have demonstrated the robustness of super-twisting higher-order sliding mode observer to uncertainties. Therefore, the proposed method can be used for the control of an uncertain robot manipulator without stability problems.…”

“…Based on [31,32,41] the super-twisting higher order sliding mode observer has a finite time convergence. Thus, the stability of higher-order super-twisting sliding mode controller and super-twisting higher-order sliding mode observer has been guaranteed separately.…”

“…Based on (4), if we defined a constant, (Θ) and Ω(X 1 , X 2 ,X 2 , t) < Θ, then according to [32,40,41] the convergence and stability can be guaranteed by defining the sliding gains (α 0 , α 1 , α 2 ) as follows:…”

Fault Tolerant Control Using Fractional-order Terminal Sliding Mode Control for Robotic Manipulators

“…To acquire benefits of TSM and FO control, and avoid the singularity problem, sliding surface has been designed in [15,19]. Motivated by the aforementioned techniques, accurate and rapid control performance for an n-degree of freedom (n-DOF) manipulators in finite-time, the following referred FONFTSM surface can be selected as…”

“…For robotic applications, there are few FTC methods that have been proposed, concern with the finite-time convergence. In [19], Non-Singular Fast Terminal Sliding Mode Control (NFTSMC) has been used to obtain rapid convergence and improvement in chattering and singularity problem, while time delay estimation (TDE) based FTC has been utilized for estimation of uncertainties and actuator faults. Since, the TDE is developed by inserting the delay in control method, which may deteriorate the performance of the system.…”