MODELING AND CONTROL OF BACKLASH IN THE DRIVE MECHANISM OF A RADIALLYROTATING COMPLIANT BEAM

The exclusion of the dynamic characteristics of indirect drives, from the controller design, has often led to a degraded performance in prec ision servomechanisms. lit this study, the adverse effects of backlash , in the drive mechanism of a radially rotating flexible beam, are exa mined. The topological variations of the structure are handled by late nt constraint equations which can be rendered active through the monit oring of the contact torque as well as kinematic indicators. A ''backl ash controller'' is introduced to replace the original controller of t he beam only during the period of gear disengagement. The experimental and numerical results provide a qualitative validation of the backlas h model. The relationships with which the backlash in gearing would in teract with both the servo-loop controller and the structural flexibil ity of the system are investigated In addition, the digital simulation s have proven that the ''backlash controller'' provides a viable appro ach in reducing the adverse effects of backlash on the overall system response.