Fault-Tolerant Control of a Dynamic Positioning Vessel with Thruster Faults Based on Improved Adaptive Control Allocation

This paper proposes an improved adaptive control allocation-based fault-tolerant control (IACA-FTC) scheme to address partial or complete thruster faults for a dynamic positioning (DP) vessel. First, an adaptive control allocation algorithm is developed to perform online adaptive reconstruction of the configuration matrix for the faulty propulsion system, aiming to minimize deviations in control allocation given the current propulsion capacity. Second, a differential term is incorporated into the adaptive updating law to mitigate thrust jitter during the adaptive process. The analysis, based on Lyapunov stability theory, demonstrates that all error signals in the control allocation closed-loop system are uniformly ultimately bounded. Finally, simulated comparison experiments based on the DP vessel thruster faults scenario indicate that the designed IACA-FTC method can effectively handle partial and complete thruster failures and improve the fault tolerance capabilities of the vessel during operation. This advancement is significant for improving the safety and reliability of dynamic positioning vessels.