Research On Control Method Of Teleoperation System Based On Seven Degree Of Freedom Manipulator

With the development of space manipulator teleoperation technology,the ever-complex space as well as precise work task demand the space teleoperation robot control technology to be natural and efficient.Due to the seven degree of freedom manipulator has a very flexible operation ability and high precision operation ability,come ture teleoperation control method of seven degree of freedom mechanical arm,and a lot of complex and unknown environments can be done,it has broad application prospects.In order to meet the needs of the development of space technology in our country,the key technologies of space teleoperation was studied,a set of control system based on Virtual Prediction environment was developed.The system is mainly divided into seven parts:the man-machine interaction device(the force feedback manipulator with six degrees of freedom),the virtual prediction environment,the socket network communication,the control platform of the slave manipulator,the Schunk robot arm of seven-freedom-degree,and so on.The operator uses the hand-operate manipulator to perform a series of typical spatial tasks,such as moving,grasping,latch,etc.By using the sensors such as vision,force and distance measurement to feedback the environment information,the working efficiency was improved.The mechanical arm control unit at the end of the system,was mainly to built based on R OS(robot operating system)mechanical arm control platform.Firstly,D-H parameter analysis is carried out for the mechanical characteristics of the real manipulator.The robot arm parame ter model is established in ROS and PCAN bus communication is designed.Then,the mecha nical arm motion of forward and inverse kinematics was analyzed using the KDL Library that ROS provided(The Kinematics and Dynamics Library)it is mainly based on numerical calcul ation method and iterative methods which gives a unique solution and has good stability and f ast calculation etc.In order to improve the safety and efficiency of space operations,the design of multi modal control scheme based on safe operation of manipulator is carried out.Using sensors to collect environmental information in real time,offer the operator has a more realistic sense of presence,continuous feedback of environmental information to assist the work,and improve the safety of the operation.And discussed separately autonomous mode operation of manipulator based on teleoperation and control of local autonomous mode based on teleoperation and force assisted teleoperation control system,and the corresponding simulation is carried out.Finally,a series of experiments were designed to study the whole system.Under different delay conditions,calculation of the main virtual environment and the position tracking error and force feedback error,Then the three modes of teleoperation experiments are studied,Verify the feasibility,reliability and effectiveness of the system.