High Performance Servo Control Of Space Manipulator And Accurate Calibration Of Kinematic Parameters

At present,a lot of work in the space operation task needs to be completed by astronauts,astronauts under great physical and psychological pressure on the space station,and many extra-mission missions are difficult for astronauts to accomplish.The use of space manipulators to assist astronauts and even replace astronauts to accomplish their space missions will be of great research value and significance.However,in some high-precision space missions,it is required that the space manipulator can achieve stable and highperformance servo control and require high precision of the absolute positioning of its end.Under the premise of high-performance servo control of space manipulator,whether the kinematic parameters are accurate or not is the main reason that determines the absolute positioning accuracy of space manipulator.With the support of the National Natural Science Foundation of China(robotics astronautics humanoid theory and method),based on the laboratory robot astronaut seven-degree-of-freedom robot as a platform,this paper studies the high-performance servo control of space robot and its Kinematic parameters for accurate calibration to improve the accuracy of space robot end positioning.The main contents and achievements of this paper are as follows:First,aiming at the requirement of high performance control for servo drive of space manipulator,a servo driver controller based on DSP28335 is designed and developed,which provides hardware basis for high performance drive control of space manipulator joint.Second,the high-performance servo control of space manipulator joint is realized.Because of the nonlinear factors such as joint friction and the large load and inertia variation,the traditional PID control method parameters design is very difficult.In view of the lack of dynamic tracking accuracy of the traditional PID control method,parameters’ adjustment is complex and so on.In this paper,an adaptive control method based on feature model is used to perform feature identification adaptive control of the system,so that high performance servo control of space manipulator joints is achieved.Third,the poor positioning accuracy of the end effector of the space manipulator is mainly due to its inaccurate kinematic parameters.This paper focuses on the analysis of the reasons for the positioning error of the end effector of the space manipulator due to the error of kinematic parameters,establishes the kinematics model of the space manipulator,and a kinematic error model is established.Fourth,this paper is to solve the problem of kinematic parameters error of space manipulator,based on the kinematics error model of space manipulator,to solve the problem of highly non-linear and non-Gaussian noise in the system,a new method based on the combination of extended Kalman filter and particle filter kinematic parameter calibration algorithm is proposed,which can accurately calibrate the kinematic parameters of the space manipulator,so as to improve the precision of the space manipulator end effector positioning.Finally,the high-performance servo control experiment of space manipulator joint and the accurate calibration experiment of space manipulator kinematics parameters are carried out to improve the positioning accuracy of the space manipulator’ end effector.The experimental results prove the effectiveness and practicality of the control method and the kinematic calibration algorithm.