Adaptive Control of Space Truss Structures by Piezoelectric Actuator

Abstract

Control/structure interaction problems are much concerned with the atti tude stability of space structures and the accuracies of on-board instruments as the sizes and flexibilities of structures increase. In this paper, an attempt to integrate collocated actuators and sensors into truss structures and to suppress the vibration or to adjust the truss geometry is investigated. For both functions of vibration suppression and shape adjustment, piezoelectric actuator Type-I was manufactured. And, for the purpose of increasing the abilities of vibration suppression, another type of actuator (Type-II) was designed. Some experimental results and analyses show the capabilities of vibration sup pression and precise adjustment of truss geometry by these piezoelectric actuators.

Adaptive Structures in Japan

“…Recently, in place of the variable geometry truss, there is a trend of using the helical mast truss Murotsu and Shao, 1991;Shibuta et al, 1992;Kuwao et al, 1992;Tanaka and Hanahara, 1992;Yokoi et al, 1992). A helical mast truss is composed of tetrahedral truss elements [see Figure 2(a)]; it is therefore a simple truss.…”

“…Sekine, Shibayama, Iwasawa and Tagawa of NEC Corporation and Sunahara, Yoshida and Arikabe of Sumitomo Heavy Industries (1991) describe investigations related to the manufacture of the type-I actuators mentioned in Shibuta et al (1992), and results of numerical simulations in vibration control with a centrally placed single collocated actuator/ sensor (type-I) pair, of a seven-bay, free-free planar simple truss subjected to a unit pulse at one of the end nodes. They use linear quadratic Gaussian control, where the state of the truss is represented with all of its 32 dof, and only the first five modes are controlled using their state observer estimates, assuming a white noise-type system and sensor noises, and using Kalman filters.…”

A Synthetic Analysis on Design of Optimum Control for an Optimized Intelligent Structure

“…Generally speaking, the structural weight will increase obviously along with the increase of the required control force. For example, a piezoelectric actuator made in Japan, which can be used to control the vehicle structural vibration, weighs up to 2 kg and its actuating force is about 1000 N [3]. Because piezoelectric elements consume less power and can be operated easily by electric "eld, they nowadays act as actuators in the vibration control of intelligent space vehicle structures.…”