Modeling and Identification of Hysteresis in Robot Joints with Cycloidal Drives

摘要

Cycloidal drives (CDs) are precision transmissions that are often installed in the joints of industrial robots (IRs) with high payloads. It is well known that the hysteresis behavior of the CDs has a significant influence on the dynamic path accuracy of IRs. In contrast to harmonic drives (HDs), which are commonly used in lightweight robots, less literature has been published on the dynamic behavior of robot joints with CDs. Thus, this paper investigates the hysteresis behavior of robot joints with CDs. For the representation of the hysteresis behavior, a nonlinear auto-regressive with exogenous inputs (NARX) model is proposed and compared to a Bouc-Wen model. Both, the data-driven NARX and the Bouc-Wen model are investigated experimentally in terms of their capability for representing the hysteresis behavior of CDs. The quality of the models is validated using a laboratory setup that mimics the drivetrain of a robot joint of the high payload class.