The Research On Coaxial Double Rotor Aircraft Control System Based On Brushless Motor

The coaxial double rotor aircraft has been widely used in military and civilian because of its compact structure,high hover efficiency and good maneuverability.In order to make the coaxial double rotor aircraft has a good effect of flight and maneuvering performance in a relatively narrow space,the higher requirements about its control performance have been put forward.Therefore,this paper studies on the flight attitude control of the coaxial double rotor aircraft based on the control of brushless dc motor.Based on the performance requirement of the coaxial double rotor aircraft,this paper selects brushless dc motor with hall sensor as the actuating device of the coaxial double rotor aircraft.After a detailed discussion on the basic structure and working principle of brushless dc motor,the mathematical model of brushless dc motor has been established.Adapting the control strategy of speed-current double closed-loop and using Matlab7.10.0/Simulink to build the classic speed-current double closed-loop speed control model of brushless dc motor,the simulation results show that the proposed control strategy has good static and dynamic performance.Based on the speed-current double closed-loop speed control model of brushless dc motor,this paper designs the hardware part and software part of brushless dc motor.Firstly,IAP15F58S4 microcontroller is choosed as the control chip of the drive motor and Altium Designer software is used to design the hardware circuit of brushless dc motor in the hardware part,including power drive circuit,speed detection circuit,current detection and protection circuit,system working power supply voltage circuit,main control chip and peripheral circuit,etc.Secondly,the software part is developed by an approach of modular structure,including the main program,interrupt program and PWM wave program,etc.Finally,the test of brushless dc motor speed control system on the experimental platform has fully verified the feasibility and reliability of the proposed control strategy.Based on the flight control requirement of the coaxial double rotor aircraft,and the sufficient grasp of the basic structure,the working principle and the law of motion about the coaxial double rotor aircraft,this paper introduces the method of simplified model to establish nonlinear dynamic model of the coaxial double rotor aircraft according to the theory of mechanics and kinematics of rigid body mechanics of rigid body and kinematics,which provides the related basis for the design of flight control system.Based on the nonlinear dynamic model of the coaxial double rotor aircraft,in order to improve the attitude control's accuracy and stability of the coaxial double rotor aircraft,a flight attitude control method of the coaxial double rotor aircraft based on Fuzzy-PID control algorithm with an automatic correction factor is presented,which refers to the three channel of the coaxial double rotor aircraft including pitching,yawing,rolling.The experimental results show that the proposed method can reduce the attitude angle deviation rapidly,improve the dynamic response of the system,and enhance the control precision and stability performance of the vehicle effectively.Theoretical research and experimental results show that based on the actuating device of the coaxial double rotor aircraft,the proposed control strategy of brushless dc motor speed control system has good static and dynamic performance,at the same time,the proposed Fuzzy-PID control algorithm with a automatic correction factor on the basis of the nonlinear dynamic system model can control flight attitude of the coaxial double rotor aircraft effectively.