Abstract: During marine missions, AUVs are susceptible to external disturbances, such as obstacles, ocean currents, etc., which can easily cause mission failure or disconnection. In this paper, considering the strong nonlinearities, external disturbances and obstacles, the kinematic and dynamic model of bioinspired Spherical Underwater Robot (SUR) was described. Subsequently, the waypoints-based trajectory tracking with obstacles and uncertainties was proposed for SUR to guarantee its safety and stability. Next, the Lyapunov theory was adopted to verify the stability and the Slide Mode Control (SMC) method is used to verify the robustness of the control system. In addition, a series of simulations were conducted to evaluate the effectiveness of proposed control strategy. Some tests, including path-following, static and moving obstacle avoidance were performed which verified the feasibility, robustness and effectiveness of the designed control scheme. Finally, a series of experiments in real environment were performed to verify the performance of the control strategy. The simulation and experimental results of the study supplied clues to the improvement of the path following capability and multi-obstacle avoidance of AUVs.

Key words: Path following , · Obstacle avoidance , · Bioinspired , · Spherical underwater robot (SUR) , · Lyapunov theory