Experimental Verification of Elastic Space Manipulator Adaptive Control.

Abstract

Structural dynamics behaviour of elastic space manipulators is specifically influenced by the amount of payload mass and by the configuration angle between upper and lower limb. For effective manipulator control, the controller gains need to be adapted to the momentary arm behaviour and configuration. Adaptive control schemes therefore have been designed and tested in real-time for a typical space manipulator of long range, such as the ESA European Robotic Arm (ERA). The experimental verification has been performed using a gravity-compatible 1:5 scaled replica of ERA, that is part of the telerobotic servicing operations testbed at DLR in Ober- pfaffenhofen. This manipulator system allows for testing of the new adaptive control schemes that have been developed for efficient reduction of settling time in space operations. The design criterion is maximal distance between the imaginary axis of the system's root locus and the closest pole to it. The pole are not strictly allocated, but their relative positions to each other are determined.