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This paper describes a methodology for validating a ground-based, hardware-in-theloop, space-robot simulation facility. This facility, called ''SPDM task verification facility,'' is being developed by the Canadian Space Agency for the purpose of verifying the contact dynamics performance of the special purpose dexterous manipulator (SPDM) performing various maintenance tasks on the International Space Station because the real SPDM cannot be physically tested for 3D operations on the ground due to the gravity. The facility uses a high-fidelity SPDM mathematical model, known as the ''truth model'' of the space robot, to drive a hydraulic robot to mimic the space robot performing contact operations. In this research different techniques were studied for practically verifying that the complex simulation facility preserves the dynamics of the truth model of the space robot for space-representative contact robotic tasks. Based upon the study and many years of experience in developing and verifying space robotic systems, a practical validation strategy including detailed test cases was developed along with a set of quantitative criteria for judging the validation test results.

This article addresses the kinematic modeling and the determination of the singularity loci of spatial five‐degree‐of‐freedom parallel mechanisms with prismatic or revolute actuators. The architecture of the spatial five‐degree‐of‐freedom parallel mechanisms is first introduced. Then, algorithms are derived for the solution of the inverse kinematic problem for the two types of mechanisms considered here. Two different methods are presented for the derivation of the velocity equations and the corresponding Jacobian matrices are derived. The numerical determination of the workspace boundaries is then briefly discussed. Finally, the determination of the singularity loci is performed, using the velocity equations, and examples are given to illustrate the results. It is shown that the vector formulation of the velocity equations leads to more efficient algorithms for the determination of the singularity loci. Spatial five‐degree‐of‐freedom parallel mechanisms can be used in several robotic applications as well as in flight simulators. The kinematic analysis and the determination of the singularity loci are very important design issues. © 1997 John Wiley & Sons, Inc.