Mathematical Problems in Engineering 
Volume 2007 (2007), Article ID 12361, 19 pages
doi:10.1155/2007/12361
Research Article

Joint Dynamics Modeling and Parameter Identification for Space Robot Applications

Adenilson R. da Silva,1 Luiz C. Gadelha de Souza,2 and Bernd Schäfer3

 1Space System Division, National Institute for Space Research (INPE), Avenida dos Astronautas 1758, São José dos Campos 12201-970, SP, Brazil
2Space Mechanics and Control Division, National Institute for Space Research (INPE), Avenida dos Astronautas 1758, São José dos Campos 12201-970, SP, Brazil
3Deutsches Zentrum für Luft- und Raumfahrt, Oberpfaffenhofen, Wessling 82234, Germany
Received 31 August 2006; Accepted 5 March 2007

Recommended by José Manoel Balthazar

Abstract

Long-term mission identification and model validation for in-flight manipulator control system in almost zero gravity with hostile space environment are extremely important for robotic applications. In this paper, a robot joint mathematical model is developed where several nonlinearities have been taken into account. In order to identify all the required system parameters, an integrated identification strategy is derived. This strategy makes use of a robust version of least-squares procedure (LS) for getting the initial conditions and a general nonlinear optimization method (MCS—multilevel coordinate search—algorithm) to estimate the nonlinear parameters. The approach is applied to the intelligent robot joint (IRJ) experiment that was developed at DLR for utilization opportunity on the International Space Station (ISS). The results using real and simulated measurements have shown that the developed algorithm and strategy have remarkable features in identifying all the parameters with good accuracy.