AAS 95-397

Slewing Dynamics and Vibration Control of Flexible Space Shuttle Remote Manipulator

C. L. Kirk, A. Oria, Cranfield University, Bedford, UK, and F. Hammer, University of Stuttgart, Germany

Abstract

This paper gives an analytical solution for in-plane slewing of a flexible two-arm remote manipulator system (RMS) with a rigid payload. Flexibility is represented by means of aone mode shape for each arm. The pinned-free configuraion of the arms is synthesised from a rigid rotational degree of freedom and a cantilever beam deflection function. The resultin four-degree-of freedom sysem is reduced to two-degres-of freedom by eliminating the rigid body degrees of freedom from the equations of motion. Torque motors at the shoulder and elbow joints provide constant acceleration--deceleration, using the computed torque method for a rigid system. Both structural damping and closed-loop active damping control are investigated for elimination of vibration during the slew motion. Eigenvalues are evalutated at different positions of the slowly varying configuration and are found to remain almost constant. The minimum reduced order dynamic model enables a clear understanding of the dynamics of the system to be obtained and can be used as a check for comprehensive flexible multi-body programmes.