Frequency-Domain System Identification of a Large Segmented Space Reflector

The NASA sponsored Structures Pointing and Controls Engineering (SPACE) testbed at CSULA is an experimental apparatus that is capable of performing experiments that simulate the complex dynamics of a large segmented optical system (James Webb Space Telescope). It is intended to serve as a generic experimental facility that can address in an integrated way the problems associated with control and structure interaction, distributed control of multi-input multi-output systems, optics, electronics, actuator and sensor design, and digital implementation. System identification experiments, aimed at achieving an accurate system model, would aid in the design of precision control techniques to satisfy the strict control requirements for this complex flexible structure. This paper describes an iterative, offline, frequency-domain, data fit approach for estimation of a mathematical model of this complex MIMO flexible structure. Black-box parameterization of the MIMO system is achieved by modeling the input-output relationships within the system as LTI ordinary nth-order difference equations. In a multi-band approach, non-linear least-squares optimization would provide the solution to the system parameters