Double-boundary interval fault-tolerant control for a multi-vector propulsion ROV with thruster failure

Purpose A novel fault-tolerant control (FTC) method is proposed to assure the stability of the remote-operated vehicle (ROV) by considering the thruster failure-induced model perturbations. The stability of the ROV with failures is guaranteed and optimized with the determined model perturbation set. The effectiveness of the double-boundary interval fault-tolerant control (DBIFTC) is verified through the experiments and proves that the stability is well maintained, which demonstrates a decent performance. Design/methodology/approach This paper studies a control problem for a multi-vector propulsion ROV by using the DBIFTC method in the presence of thruster failure and external disturbances. The ROV kinematics and dynamical models with multi-vector-arranged thruster failure are investigated and formulated for control system design. Findings In this paper, the authors address the FTC problem of ROV with multi-vector thrusters and propose a DBIFTC scheme. The advantage is that as the kinematic system model of ROV is preanalyzed and identified, the DBIFTC becomes more effective. The mathematical stability of the system under the proposed control scheme can be guaranteed. Research limitations/implications The ROV model used in this paper is based on the system identification of experimental data. Although this model has real experimental value and physical significance, the accuracy can be further improved. Practical implications Cable-controlled underwater ROVs are widely used in military missions and scientific research because of their flexibility, sufficient load capacity and real-time information transmission characteristics. The DBIFTC method proposed in this paper can effectively reduce the problem of underwater vehicle under propeller failure or external disturbance and save unnecessary cost. Social implications The DBIFTC method proposed in this paper can ensure the attitude stability of ROV or other underwater equipment operating in the event of propeller failure or external disturbance. In this way, the robot can better perform undersea work and tasks. Originality/value The kinematics and failure mechanisms of the ROV with multi-vector propulsion system are investigated and established. An optimized DBIFTC scheme is investigated to stabilize ROV yaw attitude under the thruster failure condition. The feasibility and effectiveness of the DBIFTC is experimentally validated.