Research Of Telerobot Based On Virtual Envirment Modeling

Space robot can accomplish important tasks in place of human being,and becomes the main means to carry out deep space exploration.Due to the spatial separation between the operator and robot,there is large delay in signal transmission,greatly affecting the operation quality.The interactive teleoperation robot system based on the virtual environment modeling technology can reduce the influence of delay,improve the stability and safety of the operation,and has a wide application prospect.The virtual environment modeling technology is closely related to the accuracy of the environment model.In this paper,a novel method is proposed to precisely restore real environment.Firstly,the virtual environment is divided into two parts: the known robotic arm model and the complex unknown operation scene.The model import method and the camera information extraction are adopted respectively.The environmental point cloud information is superimposed on the robot arm model through the coordinate system transformation to complete geometric modeling.At the same time,the force signal produced by the contact between the manipulator and the object is used to correct the model of the virtual environment.Then,D-H parameter analysis is carried out based on the mechanical characteristics of the robot to complete the forward and inverse kinematics analysis.In the view of the dynamic modeling of the manipulator,the mass-damping-spring dynamic model is introduced in detail.According to the feedback information of the force and position,the sliding average least square method based on the forgetting operator is used to identify the dynamic parameters of the environment and calculate the virtual contact force.Besides the theoretic analysis,a series of experiments including position tracking,interactive force tracking and environmental dynamic parameter identification are designed and completed.The results show that the proposed virtual environment modeling method based on point cloud can effectively reduce the effect of time delay.It has good force and position tracking effect in time delay of 0~10 seconds.It is expected that the space telerobot based on virtual environment modeling technology will be applied to more and more complex space activities,such as scientific experiments in space special environment,satellite maintenance and recovery,maintenance and development of space stations.