Research On Control System And Experimental Platform Of Manipulator Joint Based On RTX

In recent years, with successful development and application of space roboticsand space station, space manipulator technology has attracted more and moreattention. Meanwhile, the increasingly sophisticated demand for robotic spacemissions needs a better performance of the manipulator. In this one, a modularrobotic joints, as the most important component, can be said directly determinewhether the tasks can be successfully completed. Therefore, based on a large-scalemanipulator joint, this paper will develop a joint performance experimentalplatform and a real-time control system based on RTX.The primary task of test platform is designed to detect whether the joint canwork properly. Therefore, the test platform includes cosine encoders, torque sensorsand magnetic brakes, to complete the joint position detection, joint output torquedetection and other tasks. In addition, the test platform needs to provide convenientand efficient environment for the identification of the joint kinetic parameters andoptimization of joint controller. Therefore, the joint test platform adds the inertiaload unit and stepper motor unit.Upon completion of the joint test platform body design, this paper hasdeveloped a joint control system software based on RTX to complete the acquisitionof sensor data as well as control of flexible joint. In this paper, the software hasbeen divided into two subsystems, a non-real-time Win32subsystem and a RTSSreal-time subsystem. Non-real-time subsystem is designed to interact with user aswell as monitoring of joint states. Using RTX real-time microsecond timer,real-time control of flexible joints and the communication with joint drive havebeen completed. The two subsysterms use the shared memory to communicate. Inaddition, to satisfy the real-time requirements, this paper developed a data storagemodule and a1553B-PCI card drive in the RTX driver environment.In order to verify the stabilty of the control system and its joint test platform,this paper carried flexible joint parameter identification experiments and completeda joint state feedback controller design. Parameter identification experiments aredesigned to get joints stiffness, joint damping, motor torque and motor side frictioncoefficient and other related parameters. Also, this paper adds torque feedbackinformation into state feedback controller, introduces the concept of nominalrigidity, and explains how to calculate the controller feedback gains.Finally, this paper describes the application of joint control systems and its testplatform, including thermal vacuum test and vibration test.