Virtual Fixtures for Bilateral Telemanipulation

This dissertation addresses three related topics in the application of virtual fixtures to bilateral telemanipulation systems. Bilateral telemanipulation is the direct human control of a remote robot, with force and/or tactile feedback, and virtual fixtures are guidance modes, implemented in software, that assist the user in accomplishing a telemanipulated task. The first topic addressed in this dissertation is the design of functional and stable forbidden-region virtual fixtures, which prevent robot motion into forbidden-regions of the workspace. Metrics are defined to evaluate the effectiveness of forbidden-region virtual fixtures, and a human-factors experiment uses these metrics to quantify how users interact with various combinations of forbidden-region virtual fixtures and telemanipulation control system. A method to predict system stability that incorporates an explicit model of the telemanipulator and bounding models of human users is created and experimentally verified. Next, a new condition is presented for the passivity of a virtual wall with sampling, sensor quantization, and friction effects, for an impedance-type robot. This condition is experimentally verified to correspond to recognizable physical behaviors. It is then shown that virtual fixtures and bilateral telemanipulators can be designed indepen-