Structural Dynamics Model of a Cartesian Robot

Item

Title
en_US Structural Dynamics Model of a Cartesian Robot
Creator
en_US Reynoso, Alfonso Garcia
Date
2004-10-20T20:11:13Z
Date Available
2004-10-20T20:11:13Z
Date Issued
en_US 1985-10-01
Identifier
en_US AITR-1009
uri
http://hdl.handle.net/1721.1/6965
Abstract
en_US Methods are developed for predicting vibration response characteristics of systems which change configuration during operation. A cartesian robot, an example of such a position-dependent system, served as a test case for these methods and was studied in detail. The chosen system model was formulated using the technique of Component Mode Synthesis (CMS). The model assumes that he system is slowly varying, and connects the carriages to each other and to the robot structure at the slowly varying connection points. The modal data required for each component is obtained experimentally in order to get a realistic model. The analysis results in prediction of vibrations that are produced by the inertia forces as well as gravity and friction forces which arise when the robot carriages move with some prescribed motion. Computer simulations and experimental determinations are conducted in order to calculate the vibrations at the robot end-effector. Comparisons are shown to validate the model in two ways: for fixed configuration the mode shapes and natural frequencies are examined, and then for changing configuration the residual vibration at the end of the mode is evaluated. A preliminary study was done on a geometrically nonlinear system which also has position-dependency. The system consisted of a flexible four-bar linkage with elastic input and output shafts. The behavior of the rocker-beam is analyzed for different boundary conditions to show how some limiting cases are obtained. A dimensional analysis leads to an evaluation of the consequences of dynamic similarity on the resulting vibration.
Extent
15359629 bytes
5890632 bytes
Format
application/postscript
application/pdf
Language
en_US
Relation
en_US AITR-1009
Item sets
AI Technical Reports (1964 - 2004)