Heading Control of Unmanned Surface Vehicle With Variable Output Constraint Model-Free Adaptive Control Algorithm

Based on model-free adaptive control (MFAC) theory, this paper presents a variable output constraint MFAC (VOC-MFAC) algorithm to enhance the robustness of an unmanned surface vehicle's (USV's) heading subsystem. The contributions of this paper are as follows. First, a controller output constraint function is proposed to solve the system's control performance sensitivity to the redefined output gain when the redefined compact format model free adaptive control (RO-CFDL-MFAC) method is used to control an unmanned surface vehicle's heading. Second, the compact format dynamic linearization data models for a USV's angular velocity subsystem and heading subsystem are established, and the convergence of the closed-loop system under environmental disturbances is proven through rigorous theoretical analysis. Finally, the control algorithm proposed in this paper is simulated and tested in the field using the “Dolphin IB” unmanned surface vehicle platform developed by our research group, and the effectiveness of the VOC-MFAC algorithm is verified by the experimental results.