Dynamics, Control and Simulation of Elastic Space Manipulators.

Abstract

Thre most important subjects of this paper are:the analysis of the dynamics of vibration of space manipulators; the design of new con- trol laws for the actuators and the simulation of flight behaviour for ground-based teleoperation. From the control point of view it is very important to know the lowest free vibration eigenfrequencies depending on various parameters like link and end-body masses, centre of gravity position, moment of inertia, decentred joint masses(motors inside links) and relative angle between upper and lower arms (links). Simplified models with exact solutions and more complexmodels with approximated solutions are discussed and compared.The analytical frequency estimations can be computed very quickly and areimplemented in adaptive control algorithms for compensating changes in the free vibration frequencies during the movement or with payloadchange. The emphasis is given for analytical tuning methods of P, PI and PID controllers, with the design criterion of maximal distance between the less distant pole and the imaginary axis of the root locus of the local system. Modern control approach is not neglected, but also used for dynamic compensation and analysed for confirming results. Numerical simulations have validated results and experimentsare in march.