Analysis and control of kinematic error in harmonic gear drive mechanisms
Ghorbel, Fathi H.
Master of Science
Harmonic gear drives have found increasing application in high performance and precision servomechanisms due to their attractive physical and dynamic properties. However all harmonic gear drives exhibit undesireable nonlinear kinematic error and the ability to control and compensate this error is limited to obtaining an appropriately accurate and controllable representative mathematical model. A comprehensive literature search revealed a wide effort towards characterization with little or no effort to modeling and control. This work adopts existing models of kinematic error characterized in the literature and presents modeling techiques such that for any model of kinematic error used, the PD-control law will effectively regulate the control variable to the desired position. Additionally, asymptotic stability result reveals that in case of PD control, sensors should be placed to measure at the load end.