Robust fault tolerant control of robot manipulators with global fixed-time convergence

In this paper, a robust fault tolerant control, which provides a global fixed-time stability, is proposed for robot manipulators. This approach is constructed based on an integration between a fixed-time second-order sliding mode observer (FxTSOSMO) and a fixed-time sliding mode control (FxTSMC) design strategy. First, the FxTSOSMO is developed to estimate the lumped disturbance with a fixed-time convergence. Then, based on the obtained disturbance estimation, the FxTSMC is developed based on a fixed-time sliding surface and a fixed-time reaching strategy to form a global fixed-time convergence of the system. The proposed approach is then applied for fault tolerant control of a PUMA560 robot and compared with other state-of-the-art controllers. The simulation results verify the outstanding fault estimation and fault accommodation capability of the proposed fault diagnosis observer and fault tolerant strategy, respectively. (C) 2020 The Franklin Institute. Published by Elsevier Ltd. All rights reserved.

Automated summary

This paper proposes a robust fault tolerant control for robot manipulators that provides global fixed-time stability. The simulation results confirm the outstanding fault diagnosis and fault-tolerant capabilities of the proposed approach.