93-117
Optimal Path Planning For Satellite Mounted Robot Manipulators
V. H. Schulz* And H. G. Bock** And R. W. Longman***
Abstract
In the future, robots will be used for satellite construction in space, for automated maintenance operations, manipulation of satellites, and eventually for manufacturing operations. This will often require the manipulation of loads that have a mass that is not insignificant compared to the mass of the satellite on which the robot is mounted. here we develope robot path planning algorithms for space based robots. These algorithms apply when the attitude control system is turned off, so that attitude disturbances form robot motion do not cause attitude fuel consumption. the robot paths are planned in such a way that at the end of the maneuver, the satellite attitude is returned to its original value, so that no attitude control system action is required. The typical ground based path planning technique of linear interpolation is generalized here to develop the closest possible trajectory that is executable in space while preserving the desired final satellite attitude. Other path planning methods that generate minimum energy, minimum time , and minimum acceleration disturbance to the spacecraft are developed. The algorithms make use of a sequential quadratic programming based multiple shooting method, used earlier by the authors to produce time optimal paths in ground based robots . Numerical examples are given to illistrate the effectiveness of the methods, and to give some understanding of the nature of the space based robot tajectories.
*Academic Assistant, IWR Interdisciplinary Center for Scientific Computing, University of Heidelberg, Im Neuenheimer Feld 368, WD-6900 Heidelberg, Federal Republic of Germany.
**Professor of Scientific Computing, IWR Interdisciplinary Center for Scientific Computing, University of Heidelberg, Im Neuenheimer Feld 368, WD-6900 Heidelberg, Federal Republic of Germany.
***Professor of Mechanical Engineering, Columbia University, Seeley W. Mudd Building, New York, New York 10027-6699.