The complexity of robotic systems usually necessitates the use of digital computers in their control. When a sensory- feedback control loop is closed around a robot and its com puter system, the real-time flow of data through the computer strongly influences the fidelity of the resultant motion. The purpose of this paper is to identify characteristics of the com puter controller that have the greatest impact on the perform ance of the system and to show, by means of an example, how the performance may be enhanced through the use of digital control techniques.
The Stanford Robotic Aid is a computer-assisted telemanip ulator equipped with optical proximity sensors and a multi processor control system. Digital control techniques are used in the study of its application to a surface-following task. Thè dynamic behavior of the manipulator and the computer network is modeled by a set of difference equations. Propor tional sensory feedback is analyzed through use of a root- locus method, and a pole-placement method is used to design a state-feedback controller. The actual behavior of the system in a step-response test is compared to the prediction of the model.
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