STATIC SHAPE CONTROL OF SPACE-TRUSSES WITH PARTIAL MEASUREMENTS

The paper addresses the problem of predicting the statistics of shape distortion of space truss structures when measurements are limited to the distortions in a subset of the members of the truss. Expressions f or the average values of a quadratic measure of the distortion in term s of mean values and covariances of member length errors are developed . An example of a 150-member antenna truss is used to assess the perfo rmance of static shape control Kith active members used as collocated sensors and actuators. Actuator locations are selected based on geneti c algorithm optimization, It is found that performance is poor even wh en large numbers of sensor-actuator pairs are used. This indicates tha t it may not be practical to rely on incomplete measurements of member distortions to achieve reasonable levels of shape control.