Research On Control Method Of Multi-Rotor UAV Three-Axis Stabilized Platform

UAV have been widely used in the field of high-precision aerial photography such as aviation remote sensing,but because the attitude of the drone is susceptible to a variety of external factors,the quality of aerial photography will decline.In response to this problem,it is proposed to use a three-axis stabilized platform to improve the aerial photography quality of the UAV.This paper studies the stabilization control method of the multi-rotor UAV three-axis stabilized platform.This paper analyzes the attitude description and mathematical model of the three-axis platform in detail,and proposes a control algorithm that can effectively improve the stability control accuracy of the three-axis platform.The main content of the paper: first of all,this article describes the attitude description,kinematics and dynamics models of the three-axis stabilized platform,and the motor model in detail.Based on the structure of the three-axis stabilized platform,the attitude relationship between the frames is analyzed.The dynamic characteristics of the pan-tilt motor were studied,which laid the foundation for the research of the three-axis stabilized platform control method.Then,the PTZ control system structure is designed based on the PTZ mathematical model,and it is controlled using classic PID control and LQR control methods,and the simulation is realized.Based on comparing the advantages and disadvantages of the two traditional PTZ control methods,this paper proposes an ESO?LQR composite control method and conducts in-depth research.It is proposed to use the extended state observer(ESO)to observe and compensate the coupling interference on the axis of the gimbal frame and the external interference,and use the double-error LQR controller to track the target while isolating the interference of the UAV fuselage.So as to achieve the purpose of strengthening the stability of the three-axis stabilized platform.The simulation results of the pan-tilt control under the two flying conditions of drone hovering and maneuvering show that the control method proposed in this paper has high control accuracy and the highest control accuracy can reach 0.0177°;The system also has a small amount of overshoot,suitable for control occasions where the target switches suddenly and has strong ability to track command signals.;In the control of three attitude angles,the error of the ESO?LQR composite control method is greatly reduced compared to the traditional pan-tilt control method.It is proved that this control method greatly improves the stability of the three-axis stabilized platform under the premise of improving the control accuracy.It shows the effectiveness of the compound control method studied in the three-axis stabilized platform control.Simulation verification results show that the control method studied in this paper has a good effect on the three-axis stabilized platform under different working environments,and will provide strong theoretical support for UAV remote sensing and other work.