Development of a Virtual D.o.f. Motion Platform for Simulation and Rapid Synthesis

This paper describes the design, development, and utility of a fully operational computer simulation of a 6 degree-of-freedom motion platform. Such devices are commonly used for a wide variety of flight simulation, driving simulation, location-based entertainment, and training applications worldwide. Such a “virtual motion platform” will provide a fast, easy, and safe mechanism by which new candidate motion excursions can be tested and refined. As such, the integrity of the expensive and delicate physical hardware need not be compromised by motion patterns that might be detrimental to the limits of the hardware. The development of the NYSCEDII Virtual Motion Platform (NVMP) began with the design of a highly detailed CAD model of our existing Moog 2000E motion platform. Its development will be outlined in brief. With the static CAD model developed, the authors were then able to convert the model into a dynamic entity by using an inverse kinematical approach. The utility of these previously published algorithms will be presented, and their practical performance discussed. The NVMP has been designed to be highly user-interactive so as to allow for human “in the loop” intervention and control, and numerous of these features will be outlined and their utility demonstrated. Quantitative and qualitative comparisons between the NVMP and the physical motion platform will be discussed. Finally, the current state of the NVMP, as well as future planned features for the simulator (such as the incorporation of sophisticated washout algorithms and I/O plotting utilities) will be presented and discussed at the closure of this document. ____________________ * Member AIAA, Research Scientist † Student member AIAA, Research Assistant Copyright © 2004 by K.F. Hulme and A. Pancotti. Published by the American Institute of Aeronautics and Astronautics, Inc. with permission. Background A motion platform, parallel manipulator, motion base, or Stewart Platform is a powered, mechanical, self-contained motion system. Such systems are commonly used for motion simulation and training activities, and common applications include: flight simulation, driving simulation, industrial equipment training, and location-based entertainment (i.e. amusement rides and simulation), to name a few. Figure 1: Moog 2000E motion platform Moog, Inc. of East Aurora, New York donated a 6 degree-of-freedom (D.O.F) 2000E model motion platform to the NYSCEDII research facility for which the proposed research will be performed. Refer to Figure 1. The 6 D.O.F’s present on the Moog motion system are commonly referred to with the following nomenclature. Translation is defined as “heave” (up and down – Z axis), “surge” (forwards and backwards – X axis), and “sway” (side to side – Y axis). Rotation is defined as “roll” (tilt about the X-axis), “pitch” (incline about the Y-axis), and “yaw” (twist about the Z-axis). Refer to Figure 2 for a detailed illustration of the 2000E model reference system. 24,26