Research On Optimization And Experiment Of Quad-rotor PID Flight Control System Based On Conjugate Gradient Algorithm

Quad-rotor aircraft is an important part of research in the field of intelligent robot,the quad-rotor aircraft has been widely used in civilian,industrial and military fields as a result of its simple structure,easy to operation,light weight and small size,high flexibility and other characteristics.Scientific personnel have paid great attention to the research since quad-rotor aircraft processes below characteristics: involving a wide range of fields,high technical requirements,multi-variable nonlinear and under coupling and so on.The real-time,stability,maneuverability and load capacity of four-rotorcraft have become the focus and difficulty of research at home and abroad.Based on the hardware platform of four-rotorcraft,this thesis establishes an incomplete mathematical model,and studies the efficiency of the conventional aircraft control algorithm,then finishes the related program through the graphical software LabVIEW.Finally,trying to reduce the disturbance,under the premise of human-computer interaction,the theoretical emulation and actual test of the four rotor-craft are realized.This thesis analyzes the contribution of scientific researchers on four-rotor aircraft at domestic and overseas.On the basis of Newton's law,Euler conversion equation and LPV criterion,the four-rotor non-complete model is established by analyzing the structure characteristics,control principle and flight attitude under the premise of neglecting the deformation of the body and minimizing the disturbance.The power driver module and the wireless communication unit are selected to build the four-rotor aircraft hardware platform with the NI myRIO as the main control unit,MPU-6050 as the association of acceleration and the gyroscope integrated six-axis sensor.Based on the dynamic model of four-rotor aircraft,the control parameters of digital PID are optimized by conjugate gradient algorithm.Combining the control rate of the four-rotor aircraft with the minimum variance of the control performance index,the conjugate gradient algorithm is used to iterate to calculate the optimized characteristic parameters which are constantly changing with the four-rotor aircraft attitude.The output signal of the PID controller is converted to the electrical signal to regulate the motor speed,so as to realize the adjustment of the propeller speed and changes of the aircraft attitude.The robustness of the system is improved effectively.Finally,under the condition that reducing the body jitter as much as possible,and meanwhile ensuring the accuracy and stability of the data which is acquired by inertial measurement unit MPU 6050 through the IIC bus,the communication between PC and flight control platform is implemented by Wi Fi unit,the four-rotor aircraft actual test environment is set up,using the LabVIEW programming software for simulation,and the correctness and effectiveness of the conjugate gradient algorithm for flight control PID optimization of the four-rotor aircraft are verified,which ensures the smooth operation of the whole flight control system.