Patent ID: 6205863
Filing Date: 2001-03-27
Classification: G01N,G05B,G05D

Abstract:
A material testing machine for measuring a mechanical property of a test piece based on a load given to the test piece and a mechanical change generated in the test piece, while feedback-controlling an operation of a servo system including a hydraulic actuator which gives the load to the test piece by means of a controller such that an actual load applied to the test piece coincides with a target load, comprising:gain setting means for setting the control gain for the feedback control performed during material testing;estimating means for estimating the mechanical property of the test piece based on the actual load and the mechanical change in the test piece which are periodically detected during the material testing performed while carrying out the feedback control;gain correcting means for correcting the control gain set by said gain setting means in accordance with the estimated mechanical property; andwherein said gain correcting means corrects the control gain set by said gain setting means to coincide with the control gain which corresponds to the estimated mechanical property determined by said estimating means, by searching a table in which the control gain for every type of test piece is set in advance as a function of the mechanical property of the test piece.