Design of a Sliding Mode Roll Angle Controller for AUV Based on High-Order Disturbance Observer

Autonomous underwater vehicles (AUVs) play a crucial role in underwater detection and inspection, therefore precise depth control and reliable sensor data are essential for them. However, roll angle deviation caused by environmental interference or system asymmetry often affects depth control effectiveness and sonar imaging quality. To address these challenges, this paper proposes a control strategy that combines a higher order disturbance observer (HODO) and a sliding mode controller (SMC). In this paper, an AUV mathematical model is developed to analyze the coupling between roll angle, pitch angle and depth, which is the basis of the HODO-SMC framework. Finally, the effectiveness and anti-interference ability of the controller is verified by comparing the results of simulation experiments.