Design Of Eight Rotor Aircraft Based On Hybrid Control System

In recent years,with the continuous development of space technology and automatic control technology,multi rotor aircraft is widely used in various fields with unique performance advantages.Therefore,the control capability of multi rotor aircraft is also higher.In this paper,taking flight control algorithm as the research topic,the eight rotor aircraft as the research object,around the eight rotor aircraft model establishment,attitude calculation,data fusion,flight control,hardware selection and software design and other aspects of research.The main contents of this paper are as follows:(1)The research background and research significance of the eight rotor aircraft are introduced.The research status of the hybrid control system and the control technology of the rotor aerocraft is summarized,and the technical difficulties of the eight rotor aircraft are also analyzed.(2)The motion mode of the eight rotor aircraft is analyzed.Given the body coordinate system and the ground coordinate system,the transformation relation of the Euler angle in the two coordinate system is discussed.On the basis of model condition hypothesis and rigid body dynamics,the dynamic model of eight rotor aerocraft is derived in detail based on Newton Euler equation and rigid body rotation theorem,and the mathematical model of DC motor is established by theory analysis method.(3)In order to solve the problem of low accuracy and poor reliability caused by an attitude sensor,a method of information fusion attitude calculation based on Calman filter algorithm is designed.The measurement model of attitude sensor,such as gyroscope,accelerometer and magnetometer,is described,and the expression method of four element number pose is given.The attitude information data fusion method based on Calman filtering algorithm is proposed,and the optimal estimation value of attitude angle and position information is obtained.The real-time and reliable acquisition of attitude and position information of the aircraft is realized,and the necessary data base for the next controller design is provided.(4)In order to better realize the autonomous decision and autonomous control of the position and attitude of the eight rotor aircraft in different environments,the switching between the Backstepping controllers of the PID controller in different flight states is designed by the hybrid control theory,and the problem of the system switching stability is studied.The simulation model of hybrid control system is built by MATLAB/Simulink.The attitude angle of the aircraft and the switching process of the attitude angle and height controller are studied in the conditionof takeoff,interference,obstacle avoidance and landing.In order to improve the response speed and stability of the system,a set of appropriate controllers are matched when the aircraft is flying in different states.State error,thus achieving the goal of increasing stability.The simulation results show that the eight rotor aircraft designed by the hybrid control system can effectively suppress the drift influence caused by the disturbance,enhance the dynamic performance and stability of the system,and meet the flight position and attitude control requirements.According to the design requirements of this paper and the design requirements of the hybrid control system,the hardware structure of the aircraft is introduced,and the hardware development platform of the eight rotor aircraft is selected.Based on the platform,we realized the design and debugging of the software function of the aircraft.Finally,the flight test of the aircraft is carried out,and the correctness and effectiveness of the proposed algorithm is verified.