Recent Results in Identification and Control of a Flexible Truss Structure

Results are presented from an ongoing laboratory experiment in identification and feedback control of TRW´s flexible truss structure. H¿ and ¿-synthesis design methods were used to design high-performance MIMO digital control laws for the six-input four-output system. Non-collocated feedback has reduced RMS structural vibration (as measured by the four sensors) by a factor of 48:1 open-loop versus closed-loop (60:1 on specific outputs). Frequency domain system identification, using FFT transfer function measurements and a Chebyshev polynomial curve fitting method, was the crucial factor in achieving these high performance levels.