PIEZOELECTRIC ACTUATOR FOR CONTROLLING OSCILLATION OF SPACE STRUCTURE

摘要

PURPOSE: To provide such a piezoelectric actuator as generates a large braking force with a light weight, being simple in structure, as well as high performance in turning by providing a plurality of piezoelectric elements arranged in series while held between an inner and outer cylinders. ;CONSTITUTION: Piezoelectric elements 1 are held by spacers 2 and subjected to initial compression by a preload spring 6. The kind of piezoelectric elements (sectional area, piezoelectric coefficient, length and number) is determined arbitrality, and thus the performance of an actuator can be tuned arbitrality. An outer cylinder 3 and an inner cylinder 4 slide and restrains generation of influence at the time when shearing force and bending moment are applied to the actuator. A displacement sensor 9 detects the extension/contraction of the actuator, caused by oscillations of a space structure, and the elongation/ contraction speed, and a controller outputs a proper control voltage restraining the oscillations according to the sensor value. Consequently, the piezoelectric elements 1 of the actuator elongate/contract to attenuate or control the oscillations of the space structure speedily through a rod (1) 7, a rod (2) 8.;COPYRIGHT: (C)1994,JPO&Japio