Research On Flight Control Technology Of The Unmanned Helicopter During Hover/low-speed Flight

Unmanned Helicopter (UMH) has the unique ability of flying both with the advantages of unmanned aerial vehicles and helicopters, it is valuable in military and civilian. Hover/ low-speed flight is most useful for UMH. It can increase the flight ability and safety by making an effective solution to the flight control problem of the UMH during hover/low-speed flight. It is to solve the flight control problem of UMH during hover/low-speed flight that this thesis researches on the flight control technology of UMH during hover/low-speed flight.According to the flight characteristics of UMH, the thesis has defined the basic flight modes of UMH during hover/low-speed flight. According to the characteristics of the flight modes, it has put forward the position control as the core of the flight control scheme for the UMH. It has made a comparative study of three kinds of stability augmentation control and four kinds of position control and given the characteristics of different control schemes and the application situation. It has provided a reference to the selection of flight control scheme of the augmentation and position control for the UMH during hover/low-speed. After a detailed study of the role of proportional, integral, differential and feed forward compensation control in altitude and heading control, it has designed the altitude and heading control law based on the PID feedback and feed forward compensation control. The thesis has achieved the flight function of the UMH by designing the scheme of the basic flight modes.According to the idea of "equivalent flight control", the thesis has achieved the equivalent development of flight control software and the rapid verification environment based on the RTOS32 being compatible with the WIN32 multithreading functions. The thesis also has realized the simulation environment for flight control function by integrating FlightGear with the simulation environment. The simulation results has shown that the realization of the flight mode was reasonable and the scheme of the simulation environment based on the model of FlightGear was feasible.Finally, the thesis has compared the position control scheme based on attitude command in-loop with the position control scheme based on attitude damping in-loop by simulation and flight tests. The result was consistent and showd that the position control scheme based on attitude damping in-loop was more suitable for the position control of the UMH during hover/low-speed flight.