A Novel Terminal Sliding Mode Control for the Navigation of An Under-actuated UUV

In this paper$we present a self-developed under-actuated Unmanned Underwater Vehicle (Hereinafter abbreviated as UUV). After analyzing the motion and actuating characteristics of the UUV, the maneuvering motion models are established in the horizontal plane and vertical plane separately. Considering the model parameter uncertainties and unknown environmental disturbances, the course and depth automatic operating controllers of UUV are designed respectively on the basis of the sliding mode variable structure control algorithm to overcome these problems. The stability of the presented control laws is proved in the sense of the Lyapunov stability theory. Simulations performed on the under-actuated UUV demonstrate the effectiveness of the proposed method.