Research of regional stability with robust for the depth tracking of AUV based on error space

As to the requirements of tracking time variation signals for the Autonomous Underwater Vehicle (AUV) under unstructured uncertainties, the error space method is introduced to describe the depth control system for AUV. The nonlinear model of vertical movement was linearized at a specific operating point to get a concise error space model which is useful in simulation. In order to eliminate the unstructured uncertainties, a robust controller is designed based on Linear Matrix Inequality(LMI) region stability, which satisfies the requirements of H co performance and the regional stability constrains. Finally, the depth tracking of the AUV in time domain is carried out. The simulation results show that this controller has a strong ability to inhibit the interference of modeling error and measuring noise, meanwhile ensuring the system to track the time variation signals with characteristics of rapidity and robustness.