Modeling and Control of Backlash in the Drive Mechanism of a Radially Rotating Compliant Beam

Abstract

The exclusion of the dynamic characteristics of indirect drives, from the controller design, has often led to a degraded performance in precision servomechanisms. In this study, the adverse effects of backlash, in the drive mechanism of a radially rotating flexible beam, are examined. The topological variations of the structure are handled by latent constraint equations which can be rendered active through the monitoring of the contact torque as well as kinematic indicators. A “backlash controller” is introduced to replace the original controller of the beam only during the period of gear disengagement. The experimental and numerical results provide a qualitative validation of the backlash model. The relationships with which the backlash in gearing would interact with both the servo-loop controller and the structural flexibility of the system are investigated. In addition, the digital simulations have proven that the “backlash controller” provides a viable approach in reducing the adverse effects of backlash on the overall system response.