Research On Anti-disturbance For Rotorcraft In Outdoor Environment

The purpose of this paper is to improve the anti-wind disturbance performance of rotorcraft in outdoor wind environment.This paper analyzes the outdoor wind field model and the influence of outdoor wind disturbance on the aircraft response characteristics,state estimation,position and attitude control.The main research contents are as follows:1?IC-PID(Inverse Calculation-PID)control algorithm is proposed.In order to improve the wind resistance of the aircraft,according to the established rotorcraft system model in the wind field,the position and attitude controller is designed by PID algorithm,and combined with design of Inverse Calculation Unit,designed a IC-PID control algorithm,this algorithm can according to the measured wind disturbance to adjust the state of the vehicle amount,and realize the effective compensation of wind disturbances.2?The aircraft attitude data and wind disturbance information are real-time estimated.Aiming at the problem that the aircraft does not carry the wind speed sensor but needs to know the wind disturbance force,the corresponding state estimator is designed by EKF algorithm,and the winddisturbance caused by the flight process of the aircraft is designed.The force is expanded into the state variables such that the state estimator completes the real-time estimation of the wind disturbance information while estimating the aircraft attitude data.3? AEKF(Adaptive EKF)estimation algorithm is proposed.In order to obtain more accurate real-time attitude information and wind disturbance information of the aircraft in a complex wind field environment,it is beneficial for the control system to effectively adjust the aircraft,and at the same time,in order to improve the robustness of the estimation algorithm,a AEKFestimation algorithm is designed based on the original EKF algorithm,which can adjust the system noise covariance and the measured noise covariance in real time,to avoid estimation divergence in complex and variable wind field environment.Simulation experiments shows that compared with the traditional EKF estimation algorithm,the improved AEKF has higher estimation accuracy and stronger robustness.In addition,the AEKF estimation algorithm can effectively estimate the wind disturbance information when the wind speed sensor is not used.In the wind field environment,by comparing with the single PID algorithm and the robust sliding mode algorithm,the AEKF-IC-PID algorithm proposed in this paper can improve the wind resistance of the aircraft.A multi-rotor experimental platform is built,and a Pixhawk program is designed and transplanted to the AEKF-IC-PID algorithm.In the wind field environment,the fixed height and trajectory tracking experiments are carried outrespectively.By analyzing the actual flight data,the AEKF-IC-PID control method improves the track accuracy by 29.3% compared with the EKF-IC-PID control method without using the wind speed sensor;Compared with the actual wind speed,the wind speed information estimated by the AEKF algorithm is28.4% higher than the traditional EKF wind speed estimation accuracy.The effectiveness of the proposed algorithm is verified by experiments.