Adaptive non-singular integral terminal sliding mode-based fault tolerant control for autonomous underwater vehicles

Abstract

This article proposes an adaptive non-singular integral terminal sliding mode-based fault tolerant control (ANITSM-FTC) method for autonomous underwater vehicles (AUVs) exposed to uncertainty of dynamics and potential unknown thruster failures. The developed control scheme shows unique superiority in convergence rate over the existing adaptive proportional–integral sliding mode-based fault tolerant control (APISM-FTC), and overcomes the singularity problem effectively compared to traditional sliding mode-based scheme. During the design of the ANITSM-FTC controller, radial basis function neural network (RBFNN) and adaptive technique are adopted to estimate the dynamics uncertainty. Rigorous theoretical analysis and rigorous mathematical proof based on the trajectory tracking problems of AUVs are implemented, to ensure all tracking errors asymptotically converge to zero. To more fully demonstrate the viability of the proposed ANITSM-FTC method, the simulation experiments are carried out with three different thruster failure conditions by a fair comparison of APISM-FTC. The proposed scheme inherits the advantages of dealing with the problem of possible thruster failures as well as overcoming the drawbacks of other methods.