Identification of a Flexible Truss Structure using Lattice Filters

The size and complexity of new generation space structures present a formidable challenge for on-line (adaptive) identification methods. The methods must accommodate a variety of structural changes resulting from on-orbit assembly, spacecraft docking, time-varying disturbances, etc., which significantly affect the order of the structural system´s model. TRW´s flexible truss structure was used to demonstrate the feasibility of the least squares lattice filter for the identification of both a time-invariant and a time-varying system. The results, including natural frequency estimates, frequency responses, and one-step-ahead predictions, show that the lattice filters provide accurate and timely estimates for the different configurations considered, in particular for a two-input two-output plant and a time-varying system.