Control of Vibration in Mechanical Systems Using Shaped Reference Inputs

Item

Title: en_US Control of Vibration in Mechanical Systems Using Shaped Reference Inputs
Creator: en_US Meckl, Peter Heinrich
Date: 2004-10-20T20:01:14Z
Date Available: 2004-10-20T20:01:14Z
Date Issued: en_US 1988-01-01
Identifier: en_US AITR-1018
uri: http://hdl.handle.net/1721.1/6843
Abstract: en_US Dynamic systems which undergo rapid motion can excite natural frequencies that lead to residual vibration at the end of motion. This work presents a method to shape force profiles that reduce excitation energy at the natural frequencies in order to reduce residual vibration for fast moves. Such profiles are developed using a ramped sinusoid function and its harmonics, choosing coefficients to reduce spectral energy at the natural frequencies of the system. To improve robustness with respect to parameter uncertainty, spectral energy is reduced for a range of frequencies surrounding the nominal natural frequency. An additional set of versine profiles are also constructed to permit motion at constant speed for velocity-limited systems. These shaped force profiles are incorporated into a simple closed-loop system with position and velocity feedback. The force input is doubly integrated to generate a shaped position reference for the controller to follow. This control scheme is evaluated on the MIT Cartesian Robot. The shaped inputs generate motions with minimum residual vibration when actuator saturation is avoided. Feedback control compensates for the effect of friction Using only a knowledge of the natural frequencies of the system to shape the force inputs, vibration can also be attenuated in modes which vibrate in directions other than the motion direction. When moving several axes, the use of shaped inputs allows minimum residual vibration even when the natural frequencies are dynamically changing by a limited amount.
Extent: en_US 216 p.; 17722871 bytes; 6742398 bytes
Format: application/postscript; application/pdf
Language: en_US
Relation: en_US AITR-1018
Subject: en_US control; en_US vibration; en_US robotics

Item sets: AI Technical Reports (1964 - 2004)