Optimization Of Fuzzy PID Algorithm And Its Application In UAV

Due to its simple structure,convenient operation,strong maneuverability and vertical take-off and landing,the four-rotor Unmanned Aerial Vehicle(UAV)has become a hot research topic in industry and academia.Because of the fact that four-rotor UAV is extremely sensitive to environmental change,it is not easy to make precise control of aircraft attitude.The design of UAV flight control system is a serious challenge for researchers,which makes the flight control algorithms become one of the key technologies for four-rotor UAV control.So far,the core control method of four-rotor UAV is still PID control.Under this flight control method,It is unnecessary to accurately model the system.According to the system error,the parameters of the controller are adjusted by the fuzzy rules to realize the four-rotor drone.Based on the existing research results,the design of UAV PID controller is optimized and tested.The main research content in this dissertation is reflected in three aspects.The first one is the attitude angle noise research with kalman filtering algorithm.Kalman filter algorithm is used to reduce the interference of the sense output noise to the attitude angle sensor,which improves the accuracy of the attitude calculation.Finally,MATLAB simulation and practical test are carried out to verify the effectiveness of the kalman filtering algorithm.The results show that the actual value of the attitude angle of the UAV is highly similar to the simulation curve of the Kalman filter algorithm's estimated value,which confirms that the attitude angle correction method can significantly improve the reliability of the input value of UAV flight control system.The second one is the study of UAV flight control algorithm.The design of flight control method combines the advantages of the classical PID and fuzzy control.The fuzzy PID controller with parameter self-tuning is established by selecting the appropriate fuzzy rules and the PID parameters are self-corrected.which has enhanced the adaptability of the UAV on the surrounding environment.The dual closed-loop cascade PID controller is applied in the four-rotor UAV position control system to realize the control of UAV attitude Angle.The theoretical analysis results show that the fuzzy PID controller's control accuracy and anti-interference ability are improved,but the steady-state error is larger than that of the traditional PID controller.By analyzing the dynamic characteristics and the source of noise of the UAV flight control system,the PID controller is optimized under the specific application environment.Finally,the software simulation platform of flight control system is built by using MATLAB and the effectiveness of the optimized controller is validated.The third one is the research and experimental analysis of the setup of the UAV experimental platform.To verify the effectiveness of the PID controller designed and optimized for the actual control of the UAV,the construction of the UAV software and hardware platform and actual flight test are described in the fourth chapter.This chapter describes the hardware functions and driving circuits of the experimental platform.The software design part gives the algorithm flow chart of the drone control and the flow chart of the sensor acquisition data and data processing algorithm.During the actual test flight,the UAV's attitude information is transmitted back wirelessly to the remote control,and the remote control can forward the attitude information to the PC through the serial port.Real-time data is observed and recorded on the PC side with MATLAB and the fluctuation of the data is divided to obtain the control effect of the PID controller.Test flight experiments show that the algorithm has a good effect on attitude control.In-depth research on the control technology of the four-rotor UAV has profound significance in promoting the development of related industries,creating economic benefits and strengthening national defense construction.This dissertation makes an in-depth study on UAV attitude Angle correction,control method and experimental platform construction,which has certain theoretical value and practical significance.