Research On Stable Tracking Control Method Of Airborne Photoelectric Platform Based On MPC

As an important part of unmanned aerial vehicle,the stable tracking performance of airborne photoelectric platform plays an important role in the application of unmanned aerial vehicle in many fields.In the practical application process,the airborne photoelectric platform is inevitably affected by mechanical vibration,flight attitude change and other disturbances,which makes the stable tracking performance of the airborne photoelectric platform decline,and seriously restricts the application and development of unmanned aerial vehicle.How to improve the stable tracking performance of airborne photoelectric platform has become one of the hot issues in the field of unmanned aerial vehicle research.In this paper,a three-axis airborne optoelectronic platform mounted on a multi-rotor unmanned aerial vehicle is taken as the research object.It is of great practical significance to study the stable tracking control method of the airborne optoelectronic platform.In view of the above problems,the main research work of this paper is as follows:(1)In this paper,the research status and stability control technology of airborne optoelectronic platforms at home and abroad are reviewed and analyzed.According to the actual demand of airborne photoelectric platform for multi-rotor unmanned aerial vehicle,a three-dimensional solid model of three-axis airborne photoelectric platform with semi-open frame structure is established.The structure and working principle of the triaxial airborne optoelectronic platform are analyzed,and the attitude position of the triaxial airborne optoelectronic platform is calculated in detail.The kinematic coupling relationship among the three frames of the airborne optoelectronic platform,yaw,roll and pitch,is deeply analyzed.(2)According to Euler-Lagrange equation,the dynamics model of the three-axis airborne optoelectronic platform is derived and established in detail,and the interference factors affecting the stable tracking performance of the three-axis airborne optoelectronic platform are analyzed in depth.This paper provides a theoretical basis for the study of a stable tracking Control method for airborne optoelectronic platforms based on Model Predictive Control(MPC)technology.(3)Aiming at the problem that the estimation error of system state parameters is too large when Kalman Kilter(KF)is adopted in the rolling time domain stage in the process of realizing stable tracking control of airborne photoelectric platform based on MPC,Linear Quadratic Regulator(LQR)gain is introduced to revise the system state parameters estimated by KF.A stable tracking control algorithm based on Linear Quadratic Enhance Kalman Filter(LQEKF)is proposed and quadratic Enhance Kalman filter(LQEKF)is proposed.The simulation results show that the proposed LQEKF based model predictive control stable tracking method for airborne photoelectric platform can effectively reduce the estimation error,and the tracking time is shorter and the tracking error is smaller.(4)In view of the drift interference existing in MPC based stable tracking control,the traditional Real time optimization(RTO)combined with model predictive control has the problems of too long waiting time and model inconsistency.A stable tracking algorithm based on Single layer Real time optimization(SRTO)for model predictive control of a three-axis airborne opto-electronic platform is proposed.The Unscented Kalman Filter(UKF)is used to estimate the states,which serves as the connection of real-time optimization and model predictive control and reduces the waiting time.A model predictive control scheme based on SRTO is designed,and real-time optimization is carried out at each sampling time to solve the problem of model inconsistency.The simulation results show that the model predictive control based on SRTO for the three-axis airborne photoelectric platform has smaller tracking error and shorter response time.