On Finite-Time Path Tracking Control of Underactuated UUV Based on Integral Terminal Sliding Mode

A double closed-loop integral terminal sliding mode controller is put forward in this paper so as to settle the finite-time path tracing matter of under-actuated underwater unmanned vehicles (UUV) in an external unknown interference environment. First, extended state observer is designed to measure lumped disturbances and add compensation terms to the controller. Besides, the designed double closed-loop control system has a well-matched inner loop and outer loop. After outer loop controller obtains a related reference virtual speed instruction through the error between output and the desired position, the inner loop controller will then design corresponding control inputs of the system to track the routes. The controller used in the subsystem can not only solve the singularity problem but also can converge the system errors within a limited time. Finally, the simulation results indicate the robustness and strength of this method.