Design Flight Control System for UAV Full Envelope Flight

For the problem of attitude control during UAV envelope flight, the parameter uncertainty in full envelope flight was treated as a model uncertainty robustness problem. This paper select the UAV pitch angle as the control object. In order to guarantee the robust performance of the control system, height from 500m to 1000m and speed from 80m/s to 220m/s, we chose 18 trim points, so we have 18 transfer functions of the pitch channel. Next we design a flight controller for all transfer functions. To make the closed loop transfer function meet all the desired performance requirements, the composite bounds on the Nichols chart were generated with the frequency domain specifications converted from desired time domain specifications of flight control system and the design of the pre-filter and the controller was performed by loop shaping. Simulation shows that the controller has a good robust performance.