Development Of Space Load Teleoperation System Based On Force Sense Guidance

Space payload refers to the instruments and equipment in the space system that can directly realize a specific mission.More and more countries explore outer space through on orbit operation of space payload.Despite the rapid development of artificial intelligence related technologies,the degree of robot intelligence still needs to be improved to achieve full autonomous control.Moreover,due to the complexity of the harsh space environment,telerobot technology is still used to complete on orbit services such as scientific experiments.When completing the on orbit operation task,only relying on visual telepresence technology can not fully understand the operating environment,but also need force telepresence technology to make operators get real feelings.In this paper,the force guided related teleoperation technology of space teleoperation system is studied.At the same time,the stability and operation performance of the teleoperation system under random large time delay are solved,as well as how to complete the delicate and complex teleoperation tasks and improve the efficiency of the teleoperation tasks.Firstly,a space teleoperation system with force guidance is proposed.The master-slave heterogeneous teleoperation system is constructed by force feedback equipment and manipulator.The system is mainly composed of master-slave teleoperation system,slave manipulator subsystem and network communication.In this paper,the client/server model is used to develop the system,in which the master terminal system and the slave terminal system are equivalent to the client and communicate with the central control server through TCP/IP protocol.In order to solve the problem of master-slave workspace mismatch,rate mapping method is used.Secondly,due to the instability and performance degradation of the teleoperation system caused by communication delay,this paper adopts the bilateral control method based on passive theory to study the traditional wave variable teleoperation control method,and puts forward the improved wave transformation control structure and carries out the Simulink simulation verification.Since the wave variable teleoperation control method can not guarantee the stability under random time delay,this paper proposes a time-domain passive bilateral teleoperation control method based on wave variable.The improved wave transformation control structure is adopted,and the series passive controller is used in the main terminal,and the parallel passive controller is used in the slave end,so that the whole system remains passive and stable.The bubble contact experiments were carried out under 2s-3s random large delay.The position and force of the master-slave end were stable and tracked.Thirdly,when there is no contact with the environment,it is difficult to realize the precise positioning of the manipulator only by using the bilateral control method.Therefore,the virtual fixture technology is studied,and a combined virtual fixture based on artificial potential field method and cone construction is proposed to realize the precise positioning of the manipulator.The main reasons for the robot arm to be unable to accurately locate are:in the face of some obstacles in the narrow space,the manipulator will touch the obstacles in the process of human operation,as well as the inaccuracy of manual operation and muscle tremor and other factors will make the manipulator unable to accurately locate.Therefore,forbidden virtual fixture is constructed by artificial repulsion field to avoid obstacles,and virtual fixture and cone virtual fixture constructed by artificial gravitational field are used to realize precise positioning.In the end,the performance of the teleoperation system is evaluated and verified based on the experimental results.The experimental results show that the passive two-sided teleoperation control method based on wave variables and the combined fixture constructed by artificial potential field method and cone are effective.