An Adaptive Line-of-Sight Guidance Law for Path Following of AUV

Line-of-Sight (LOS) guidance law is widely used for path following of autonomous underwater vehicle (AUV) due to its simplicity and effectiveness. However, LOS guidance law has a contradiction between rapidity and overshoot, as well as a steady-state error caused by waves, wind and ocean currents. This paper proposes an adaptive LOS (ALOS) guidance law that can balance rapidity and overshoot while compensating for sideslip angle. The proposed algorithm uses adaptive parameter based on the cross-track error to real-time adjust the look-ahead distance and adaptively calculate a reasonable desired heading angle. An adaptive integral state is designed based on the adaptive parameter to compensate the impact of sideslip angle and then calculate the desired heading angle. Through stability analysis, it is proven that ALOS has uniform semiglobal exponential stability (USGES) at the balancing point. Finally, lake trials results shows that ALOS effectively suppressed overshoot and compensated for disturbance of waves, wind and ocean currents while reducing lateral cross-track error by 52.3% in similar converge speed with LOS. ALOS can effectively improve robustness of control and enhance path following performance of AUV.