A Robotics-based Testbed for Verifying a Method of Identifying Contact-Dynamics Model Parameters

摘要

This paper describes a general method of identifying the key parameters of multiple-point contact-dynamics models and a robotics-based testbed for experimentally verifying the new method. Some of the current and future flight systems are required to make physical contact on orbit for on-orbit servicing such as docking, refueling, repairing, etc. Because of the high risks associated with contact operations, the design and operation of such a flight system must be thoroughly analyzed and verified in advance by hardware testing and/or high-fidelity computer simulation. Computer simulations are increasingly playing a major role in system verification because it is extreme difficult to test 6-DOF microgravity contact dynamics on the ground. However, the accuracy of computer simulation depends not only on the mathematical model (i.e., formulation, algorithms, and computer code) but also on the values of model parameters. It is, therefore, desirable to have a systematic method which can identify multiple model parameters directly from routine physical tests of the contact components. The robotics-based experiment testbed introduced in this paper is specially designed to test and verify such a method of identifying contact parameters. The method is capable of identifying the key stiffness, damping, and friction parameters of a contact dynamics model all together from hardware test of contacting components having complicated geometries and multiple contacts. It can also be used to extract contact-dynamics model parameters of a dynamic system from its routine test of complex contact hardware. The paper discusses the major design requirements of this experimental testbed and how they are met by the specific design of the system.