A high-fidelity harmonic drive model: Experiment, simulation, and application

Harmonic drive transmissions are used in many applications including revolute joint robots. The complex dynamics of the harmonic drive can cause vibrations of the robot and trajectory errors. A high-fidelity model of the harmonic drive may be used to better understand the effect of the harmonic drive behavior on the robot performance.;In this dissertation, a thorough investigation of the harmonic drive was carried out and a comprehensive model was constructed. Empirical observations were made of the important aspects of the harmonic behavior, including hysteresis, nonlinear stiffness, nonlinear viscous damping, and kinematic error. Each of these characteristics was investigated and modeled. Subsequently, a novel model of the harmonic drive was created incorporating all of the submodels. Initial steps were taken to incorporate the complete harmonic drive model into a multibody model of a revolute joint robot. Measurements were made of a revolute joint robot for comparison to the multibody model.;The comparison of the harmonic drive behavior to the harmonic drive simulation output reveal a robust model that captures the transmission characteristics. The highly nonlinear output from the harmonic drive was well represented by the model, both statically and dynamically. In addition, the steps to incorporate the transmission model into the robot model have been detailed and all of the system parameters have been identified.