Configuration Optimization and Adaptive Controller Design of a Land-Air Amphibious Vehicle for Improved Yaw Capability

Land-air amphibious vehicles (LAVs) have been increasingly used in complex scenes and tasks in recent years due to their multi-domain mobility. In this context, the attitude stability control of flight system in disturbance environment has become a common problem to be solved and improved, especially the relatively weak yaw channel. This paper focuses on the improvement of yaw capability under external wind disturbance from two aspects of configuration optimization and adaptive stability augmentation control. Firstly, the mechanism of yaw torque increasement is revealed for the four-rotor LAV and the general optimization method for such configuration is proposed. The yaw channel control bandwidth is greatly increased with minimal structural optimization cost. Secondly, on this basis, an adaptive stability augmentation controller with real-time predictor-compensator is designed for yaw channel, which provides further guarantee for yaw wind resistance and anti-saturation ability. Finally, the simulation of proposed comprehensive scheme and the real prototype tests under turbulent wind field provided by high-power fan are carried out. Results show that the yaw tracking error is greatly reduced by 74.17% under wind disturbance and the yaw control quantity and risk of control output saturation are significantly decreased.