Piezo-electric crystals as vibration control devices for flexible spacecraft structures

摘要

The objective of this research was to explore the use of piezo-electric crystals to control vibratory motion of flexible spacecraft structures such as a space station, deployable solar arrays and antennas. This experimental and analytical investigation had a focus on the proof-of-concept demonstration of piezo-electric crystals as vibration actuators on scale models of real world space structures. Piezo-electric crystals worked well as actuators in controlling vibrations of a steel cantilever beam in the frequency range of 25 to 2000 Hz. Although their actuation was small at low frequencies, they performed very well at higher frequencies. The crystal actuators adaptation became a problem in the case of large flexible space structures such as a deployable solar boom. Its size required the use of stacked crystals to generate high control force. The low frequency and excitation force of the procured crystals were limited and the vibration control experiments on large, flexible ASTROMAST using piezo-crystals were not successful. These experiments however, suggested ways of designing and embedding large size crystal actuators to control selected modes of space structures.