JPS6450925A - Vibration tester - Google Patents

Abstract

PURPOSE:To make the motion of a vibration table smooth and to enable the highly precise reproduction of an acceleration wave form, by controlling a plurality of actuators collectively for acceleration and also by making each actuator move the vibration table with substantially the same force. CONSTITUTION:A vibration table 11 is vibrated vertically by actuators 12A-12D, and differential pressure sensors 14A-14D detect a pressure difference between the upper and lower chambers of a piston of the actuator respectively. From the respective outputs of the differential pressure sensors 14A-14D, an arithmetic control circuit calculates such static correction amounts SA-SD as making the each mean differential pressure SP of the actuators 12A-12D equal and such dynamic correction amounts GA-GD as making the each dynamic differential pressure GP thereof equal. Then, the static correction amounts SA-SD are given to the inputs of a displacement gain setting circuit respectively, while the dynamic correction amounts GA-GD are given to the inputs of an acceleration gain setting circuit respectively, so as to obtain gain control signals. By this method, the nonuniformity in the characteristics of the actuators is corrected, and the vibration table 11 is driven by the equal forces of the actuators 12A-12D.