Research On 6-DOF Captive Trajectory Simulation Mechanism Kinematics Calibration And Compensation

The Captive Trajectory Simulation(CTS)is a wind tunnel special test technique used to simulate the actual motion trajectory after the separation of the separation body from the aircraft.The accuracy of the trajectory predicted by the test mostly dependent on the motion accuracy of the Captive Trajectory Simulation mechanism.In this article,the theoretical and experimental research on error calibration and compensation technology for a wind tunnel in China Captive Trajectory Simulation test organization is carried out.The main work of this paper is as follows:(1)In this article,the specific geometric structure of the Captive Trajectory Simulation mechanism is analyzed.The positive and inverse solutions algorithm of the mechanism are established by using the DH method.At the same time,the local positive and inverse solution equations are derived for the specific linear to arc mechanism of the yaw and pitch mechanisms in the mechanism..(2)The general error source of the robot is analyzed,and then the error source that affects the positioning accuracy of the mechanism is analyzed in combination with the actual situation of the Captive Trajectory Simulation mechanism.Since the geometric error of kinematic parameters is the main error source of the mechanism,the error parameter model of Captive Trajectory Simulation mechanism is derived based on differential method and perturbation method respectively.(3)In this paper,the singular value decomposition is used to find the generalized inverse matrix method to solve the parameter error of the local linear arc-changing mechanism.A principle of discriminating D-H parameters by axis based on differential method is proposed,and then the D-H parameter error of the mechanism is solved by the Newton iteration method.The compensation algorithm of the robot is studied.The direct compensation method is introduced.The compensation equations of the forward kinematics compensation method and the inverse kinematics compensation method are derived.The Matlab is used to simulate the positive kinematics compensation method and the inverse kinematics compensation method.And compare the compensation effects of the two compensation algorithms.(4)In order to verify the correctness of the Captive Trajectory Simulation mechanism error parameter model and the DH parameter principle of the differential method for axisby-axis identification,this paper studies the calibration experiment of Captive Trajectory Simulation mechanism,and uses the laser tracker as the measuring instrument to set the DH error parameter calibration of the Captive Trajectory Simulation mechanism.The error parameter of the mechanism,the actual value of the kinematic parameter is obtained according to the error parameter,and the error compensation is performed in the forward and reverse solution program of the control system of the Captive Trajectory Simulation mechanism,and the end positioning accuracy of the Captive Trajectory Simulation mechanism before and after the compensation is compared,and the end of the compensation is completed.The compensated end positioning accuracy is significantly improved,which proves the effectiveness of the calibration algorithm and the compensation algorithm.