Design Of Active Disturbance Rejection Control Algorithm For Small 2-DOF Pan Tilt

This paper takes the infantry mobile robot in robomaster as the research carrier,designs the mechanical structure and control system of the whole machine,and focuses on the two degree of pan tilt of the robot.Aiming at the problems of low control accuracy and poor anti-interference ability in the case of a large number of random disturbances,an improved active disturbance rejection control algorithm based on LuGre friction model compensation is designed the control performance of pan tilt is improved effectively.The main contents are as follows.According to the competition rules,the reasonable scheme of infantry mobile robot is planned,and the main technical indexes are drawn up.On this basis,the mechanical structure design of the mobile chassis and two degree of pan tilt of the robot,as well as the hardware and software design of electronic control such as chassis movement,pan tilt rotation and attitude detection are completed,which meet the expected technical requirements.In order to improve the anti-interference performance of pan tilt closed-loop control algorithm,the mathematical model of pan tilt yaw rotation axis is established.Through analysis,it is concluded that the change of friction torque is the main source of interference.Therefore,a compensation method based on LuGre friction model is proposed.On the basis of physical test experiment,the dynamic and static parameters of LuGre friction model are identified by genetic algorithm,The reasonable mathematical model of friction torque of pan tilt is obtained.Due to the non-linear characteristics of pan tilt rotation,the second-order active disturbance rejection control algorithm is adopted in this paper.Through frequency domain analysis and simulation experiment,the values of each parameter in the algorithm and the setting method are obtained.At the same time,in order to improve the accuracy of the state observer,the friction torque model of pan tilt is used as the compensation term of the control algorithm.The simulation results show that the performance of ADRC algorithm after compensation is better than PID and conventional ADRC algorithm.Through the step response and sinusoidal tracking experiments,the results show that the response speed and anti-interference ability of the system are improved,which can meet the performance requirements of pan tilt control set in this paper.