Unmanned Tiltrotor Aircraft Flight Control And Test Based On The Embedded Control System

Tilt-rotor aircrafts have features of both helicopters and fixed-wing aircrafts.The ability of vertical-take-off-and-landing,long range and high cruise speed make them owning a good prospect in both civil and military field.The embedded flight control system for the small scaled unmanned tiltrotor aircraft is established including inertial sensors,navigation modules,a high-precision differential GPS and a flight control computer.The flight control system is designed providing high reliability and control accuracy.According to task's priority,program scheduling mothed is provided.The on-board sensor data fusion is performed by the Kalman filter based on quaternion to obtain the optimal attitude.A dual-redundant strap-down INS system is designed with commercial precision system being the primary navigation system and the on-board sensors being the redundant system.The control strategy of the tilt-rotor aircraft is analyzed in the full flight envelope.The fullenvelope flight control law is designed using the inner/outer loop structure.A control strategy for the automatic take-off and landing flight mode is presented.The stability of the closed-loop system and the rationality of the control strategy are verified by using the computer simulation.The flight test is performed to evaluated the performance of the rotational rate,attitude controller,altitude-hold controller and the position-hold controller.The test results have shown a good tracking capability of the controller.Flight tests for emergency situations,such as the differential GPS altitude data lost and the strap-down INS sensor faults,are performed to evaluate the performance of the emergency procedures.The automatic take-off and landing flight test are conducted to verify that the flight control system.