Towards Reducing Thruster-Flexibility Interactions in Space Robots
Space manipulators mounted on an on-off thruster-controlled base are envisioned to assist in the assembly and maintenance of space structures. When handling large payloads, manipulator joint and link flexibility become important, for they can result in payload-attitude controller fuel-replenishing dynamic interactions. In this paper, the dynamic behavior of a flexible-joint manipulator on a free-flying base is approximated by a single-mode mechanical system, while its parameters are matched with space-manipulator data. Describing functions are used to predict the dynamic performance of three alternative controller-estimator schemes, and to conduct a parametric study on the influence of key system parameters. Design guidelines and a state-estimator are suggested that can minimize such undesirable dynamic interactions as well as thruster fuel consumption.
KeywordsFuel Consumption Attitude Controller Link Flexibility Space Robot Switching Line
Unable to display preview. Download preview PDF.
- Sackett, L. L., and Kirchwey, C. B., “Dynamic Interaction of the Shuttle On-Orbit Flight Control System with Deployed Flexible Payload,” Proc. of the AIAA Guid. and Cont. Conf., San Diego, CA, 1982, pp. 232–245.Google Scholar
- Martin, E., Papadopoulos, E., and Angeles, J., “On the Interaction of Flexible Modes and On-off Thrusters in Space Robotic Systems,” Proc. of the 1995 Int. Conf. on Intelligent Robots and Systems, IROS’95, Vol. 2, Pittsburgh, PA, 1995, pp. 65–70.Google Scholar
- Martin, E., “Interaction of Payload and Attitude Controller in Space Robotic Systems,” Master Thesis, Dept. of Mech. Eng., McGill University, Montreal, Canada, 1994.Google Scholar
- Singer, N. C., “Residual Vibration Reduction in Computer Controlled Machines,” Technical Report 1030, MIT Artificial Intelligence Laboratory, Cambridge, MA, 1989.Google Scholar
- Atherton, D. P., Nonlinear Control Engineering, Van Nostrand, New York, 1975.Google Scholar