Research On Design And Realization Of Control System For Quadrotor Unmanned Aerial Vehicle

Quad-rotor is used widely in the field of military and civilian because of advantages of vertical take-off and landing, fixed-point hover, flexible movement, excellent load capacity. The design of quad-rotor control system is the research hotspot of the field. In this paper, research started around the attitude estimation and flight control system. The quad-rotor was designed by taking the actual application requirements of fire rescue into account.At first, quad-rotor movement was divided into line movement and angular movement by analyzing flight principle. The dynamic equation of quad-rotor system was established based on the movement analysis. And the characteristics of nonlinearity, the under actuated, strong coupling were detailed analyzed.The quad-rotor system includes Attitude and Heading Reference System(AHRS), flight control systems and motor drive system. The AHRS uses real-time sensor data to accurately estimate attitude. The flight control system sent the control data to the motor drive system by calculating the deviation of the actual values and expectations. After receiving control data, the motor drive system drove the rotor rotation to fly.Then, hardware system of quad-rotor was set up according to the overall design scheme of system. After a large number of experiments, attitude acquisition model, flight control model, wireless communication model, motor driving model and obstacle avoidance model can work stably and reliably, which provides the basis for attitude computation, data fusion and control algorithm.Kalman filter was introduced in attitude estimation system to get optimal attitude estimation by fusing multi-sensor data. PID and backstepping controller were designed based on the dynamic model. After testing and validating through MATLAB simulation, control algorithm was programmed into the hardware system. Finally, the real environment experiments showed the quad-rotor can work well in fire rescue environment by flying stably and avoiding obstacles automatically.