| This dissertation addresses the problem of remote manipulation in the presence of communication delays. Delays occur with earth-based control of a robotic system in space or when an untethered submersible system is controlled from the surface via an acoustic communication channel. The resulting delay in obtaining position and force feedback from the remote slave arm(s) makes direct teleoperation infeasible.; We propose a new control methodology, called teleprogramming, which allows for efficient control of a robotic system in the presence of significant feedback delays without substantial degradation in the overall system performance. A teleprogramming system allows the operator to kinesthetically, as well as visually, interact with a graphical simulation of the remote environment and to interactively, on-line teleprogram the remote manipulator through a sequence of elementary symbolic instructions. These instructions are generated automatically by the operator's station software in real time as the task progresses. The slave robot executes these symbolic commands delayed in time and, should an error occur, allows the operator to specify the necessary corrective actions and continue with the task.; Teleprogramming offers a practical compromise between the ultimate and the feasible, and provides an effective and time-efficient approach to remote manipulation. Advantages of teleprogramming over existing control methodologies include a relatively modest required level of remote site autonomy, and the absence of the need for complex automatic task planners and preprogrammed error recovery modules.; This document describes the overall conceptual architecture of teleprogramming and presents a detailed treatment of all major components of a teleprogramming system. An operational prototype system is described and preliminary experimental results are reported. Experimental results have confirmed the validity and feasibility of the teleprogramming control methodology. Sustained and efficient remote control of a robot manipulator in the presence of a five second feedback delay was successfully accomplished for simple contact tasks. |
