Dynamic Event-triggered Robust Adaptive Practical Fixed-Time Trajectory Tracking Control for Underactuated AUVs

This paper develops an event-triggered robust adaptive fixed-time trajectory tracking control scheme for underactuated autonomous underwater vehicles (AUVs) in the presence of uncertain dynamics and unknown time-varying disturbances. Here, a dynamic event-triggered mechanism (DETM) is created to reduce the transmission frequency of control commands drastically. The compound uncertain term caused by uncertain model parameters and disturbances is transformed into linearly parametric form with only one unknown parameter. By incorporating the above and a smooth function into the backstepping design tool, the fixed-time trajectory tracking control of AUVs is achieved. The theoretical analysis indicates that the tracking errors can converge to a small set around the origin in a fix time under proposed control scheme, while all signals in the AUV trajectory tracking close-loop control system are bounded. Simulation results on an AUV validate the effectiveness and superiority of the proposed control scheme.