Control of a multimodule deployable manipulator using RTX

A multimodule deployable manipulator system (MDMS), which has attractive features of kinematics and kinetics, has been developed in our laboratory. The present paper concerns implementation and evaluation of a low-level real-time controller for the MDMS, using VenturCom's real-time extension (RTX) for Windows NT in the host computer. A software module is developed using C/C++ with RTX for implementation of various control methods. As a preliminary study of the effectiveness of the control system, a conventional proportional-integral-derivative (PID) control scheme is implemented for simultaneous multilink independent joint motion of the MDMS. Several experiments of circle-trajectory following are carried out using two degrees of freedom of the outer module of the robot The performance is found to be quite accurate, providing greater accuracies at lower speeds. Further improvements in performance are realized by tuning the parameters of the PID controllers.