Fault-tolerant control based on adaptive super-twisting nonsingular integral-type terminal sliding mode for a delta parallel robot

Abstract

External disturbances, internal uncertainties and actuator faults with an unknown range have detrimental effects on controller performance of industrial robots. In this paper, to deal with such challenges, a new fault-tolerant control (FTC) strategy using a combination of nonsingular integral-type terminal sliding mode (NITSM) and adaptive high-order super-twisting (AST) control is proposed for a delta-type parallel robot. To eliminate the chattering of sliding mode controller as a key ingredient of excessive energy consumption and convergence rate reduction, high-order algorithm is applied. Stability analysis of the closed-loop system is performed using Lyapunov theory. Moreover, to achieve optimal performance, controller parameters are obtained using harmony search algorithm (HSA) by minimizing an objective function consisting of integral time absolute error (ITAE) and control signal rate. The proposed controller performance is compared with conventional sliding mode and feedback linearization control methods. The obtained results reveal the superiority of the proposed AST-NITSM.

A Novel Trajectory Tracking Control with Modified Supertwisting Sliding Mode for Human-Robot Cooperation Manipulator in Assembly Line

“…In the operation process, especially when calculating the derivative, the amount of operation is large, and the occupation of operation resources is more obvious when calculating the high-dimensional model. Therefore, considering the above reasons, equation (19) in system ( 17) is rewritten as…”

“…Reference [18] uses neural network technology and sliding mode control method to design controller. In reference [19], the combination of sliding mode control method and fault-tolerant control is adopted. In the design of the manipulator controller, the supertwisting method is used to eliminate the control chattering and realize the finite-time tracking control.…”

Active fault-tolerant control of a Schon̈flies parallel manipulator based on time delay estimation

“…The dynamic model of the four-degrees of freedom parallel robot in the presence of uncertainties and actuator fault is written as [25] M¨…”

“…In robotic literatures, various approaches have been adopted to promote the performance of SMCbased FTC [25]. Meng et al [4] designed ASMFTC for an uncertain Stewart platform which does not require fault diagnosis process.…”

Fault tolerant control based on backstepping nonsingular terminal integral sliding mode and impedance control for a lower limb exoskeleton

“…34 Some researchers showed the effectiveness of SMC-based methods for fault detection and estimation. 35,36 The high order super-twisting observer used for fault detection and isolation offers two main advantages. I) Speed estimation without using filters, II) Identifying unknown inputs.…”