Modeling of tendon-pulley transmission systems with application to surgical robots: A preliminary experimental validation

摘要

Tendon-pulley based motion/force transmission has been widely used in surgical robots. Such mechanisms, however, exhibit substantially nonlinear behavior due to tendon compliance and tendon-pulley friction. Although the power loss due to tendon-pulley friction has been broadly studied in belt-drive systems in automation and automotive industry, the concept seems to be largely unknown outside these disciplines. A tendon-pulley transmission modeling scheme was recently developed by the authors based on concepts from tendon elastic creep theory. This paper focuses on the experimental validation of the model in tendon-driven robots. Motion transmission of the first three joints of the RAVEN II <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">®</sup> surgical robot is analyzed, and backlash-like hysteresis within the transmission systems is modeled using the proposed scheme. The modeling accuracy is experimentally evaluated, showing more than 50% improvement in comparison with the conventional friction/compliance-free models.