Research On Motion Mapping And Hierarchical Singularity Avoidance Of Robonaut Teleoperation System

Recently,the traditional sense of the space manipulator is difficult to deal with complex and varied aerospace operations,so more intelligent smart robot astronaut came into being.However,due to the complex structure of robot astronauts and the unstructured space environment,the key technologies of artificial intelligence and control are not enough to support the task of autonomous robot.A practical approach is to add the operator to the control closed loop,using the ground to operate the robot astronauts to complete the space operations.In this paper,the ground teleoperation platform is established,and the key technologies such as motion mapping and singularity are studied.First,a remote control system for robotic astronauts based on Haptic Workstation is built.The kinematics model of the robot DOF 7 DOF redundant arm is established,and the closed-loop inverse kinematics of the manipulator is analyzed emphatically.The teleoperation platform integrates power support devices such as CyberForce and CyberGrasp to enable real-time remote control of robotic astronauts.The calibration of the Haptic Workstation platform was completed,and an improved data glove calibration method was proposed to solve the problem that the original reading side of the glove was coupled with the bending joint.Secondly,a motion mapping strategy based on CyberForce operator robot astronaut arm is proposed.The mapping strategy mainly includes fixed scaling factor mapping,variable scaling factor mapping and attitude adjustment mapping strategy.Among them,the fixed-scale factor mapping strategy is mainly based on the convex hull simplification representation of the manipulator working space and the workspace inclusion relation detection algorithm,which can ensure that the manipulator has as much practical space as possible.The variable scaling factor mapping strategy enables the operator to avoid obstacles and close to the target object by adjusting the mapping parameters online.The attitude adjustment mapping based on the robot arm and CyberForce's end coordinate system for incremental mapping,the operation process intuitive,the operation method in line with the operator's habit.Thirdly,a hierarchical avoidance method is proposed for the teleoperation system.This method can ensure that the manipulator does not cause the kinematic computation process to be morbid due to singularity.In this method,the hierarchical singular regions of the manipulator are divided according to the joint configuration in the singular state and the corresponding singularity evaluation index.When the robot arm is in the state of the singular state,the virtual force feedback is used to guide the movement of the main end operator.Once the robotic arm enters the pathogenic singular region,the modified trajectory reconstruction method is used to reconstruct the trajectory of the end of the manipulator.Finally,the motion mapping algorithm and the singular algorithm are simulated on the platform of robot astronauts.The experimental results prove the correctness of the above algorithm.Through the remote operation to capture the drill experiment,to prove the effectiveness of the platform.