Autonomous Landing Control of Highly Flexible Aircraft Based on Lidar Preview in the Presence of Wind Turbulence

This paper investigates preview-based autonomous landing control of a highly flexible flying wing model using short-range light detection and ranging (Lidar) wind measurements in the presence of wind turbulence. The preview control system is developed based on a reduced-order linear aeroelastic model and employs a two-loop control scheme. The outer loop employs the linear active disturbance rejection control and PI algorithms to track the reference landing trajectory and vertical speed, respectively, and to generate the attitude angle command. This is then used by the inner loop using H$_{\infty }$ preview control to compute the control inputs to the actuators (control flaps and thrust). A landing trajectory navigation system is designed to generate real-time reference commands for the landing control system. A Lidar simulator is developed to measure the wind disturbances at a distance in front of the aircraft, which is provided to the inner-loop H$_{\infty }$ preview controller as prior knowledge to improve control performance. Simulation results based on the full-order nonlinear flexible aircraft dynamic model show that the preview-based landing control system is able to land the flying wing effectively and safely, showing better control performance than the baseline landing control system (without preview) with respect to landing effectiveness and disturbance rejection. The control system's robustness to measurement error in the Lidar system is also demonstrated.