A Kane S Dynamics Model For The Active Rack Isolation System

A "Kane's Dynamics" Model for the Active Rack Isolation System

A Kane's Dynamics Model for the Active Rack Isolation System

Many microgravity space-science experiments require vibratory acceleration levels that are unachievable without active isolation. The Boeing Corporation's active rack isolation system (ARIS) employs a novel combination of magnetic actuation and mechanical linkages to address these isolation requirements on the International Space Station. Effective model-based vibration isolation requires: (1) An isolation device, (2) an adequate dynamic; i.e., mathematical, model of that isolator, and (3) a suitable, corresponding controller. This Technical Memorandum documents the validation of that high-fidelity dynamic model of ARIS. The verification of this dynamics model was achieved by utilizing two commercial off-the-shelf (COTS) software tools: Deneb's ENVISION(registered trademark), and Online Dynamics Autolev(trademark). ENVISION is a robotics software package developed for the automotive industry that employs three-dimensional computer-aided design models to facilitate both forward and inverse kinematics analyses. Autolev is a DOS-based interpreter designed, in general, to solve vector-based mathematical problems and specifically to solve dynamics problems using Kane's method. The simplification of this model was achieved using the small-angle theorem for the joint angle of the ARIS actuators. This simplification has a profound effect on the overall complexity of the closed-form solution while yielding a closed-form solution easily employed using COTS control hardware.Beech, G. S. and Hampton, R. D. and Rupert, J. K.Marshall Space Flight CenterDYNAMIC MODELS; INVERSE KINEMATICS; VIBRATION ISOLATORS; COMPUTER PROGRAMS; CONTROLLERS; ROBOTICS; COMMERCIAL OFF-THE-SHELF PRODUCTS; COMPUTER AIDED DESIGN; SPACECRAFT EQUIPMENT; RACKS (FRAMES)...

Validation of a 'Kane's Dynamics' Model for the Active Rack Isolation System