Large Space Manipulators Study
Abstract
This report documents the research performed for the Large Space Manipulator Study contract. The derivation of nonlinear dynamic models for a simple 3-D articulated, elastic structure is discussed. Kane's dynamics equations are used to obtain equations of motion is closed form; the bending deformations of the elastic links, modelled as slender elastic beams, are described with the assumed-modes method. A 2-D planar version of the dynamic model is used to predict the dynamic behavior of an experimental, articulated two-link elastic structure. Both links consist of thin elastic beams with rectangular cross section. The outer link has a tip payload of variable mass and moment of inertia. The structure is instrumented with position/rate/ acceleration/ sensors mounted at the articulations and at the end-point; strain- gauges are mounted along the links at several locations. Close agreement between the analytical predictions and the experimental measurements is documented for modal tests and for slew maneuvers of the structure. The design and implementation of several digital compensators to actively control the single elastic beam as well as the 2-DOF elastic structure are presented. The compensators are obtained using classical design techniques and the Linear Quadratic Gaussian/Loop Transfer Recovery (LQG/LTR) method.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1990
- Accession Number
- ADA227276
Entities
People
- Eric Schmitz
- Madison Ramey
Organizations
- Martin Marietta