Improved Eigenstructure Assignment Controller Design Using a Substructure-Based Coordinate System

A new control coordinate system based on the Craig–Bampton substructure representation is examined for reduced-order-model-based controller design. Eigenstructure assignment controller design using the proposed modeling approach is shown to exhibit improved accuracy over conventional normal mode modeling in both closed-loop eigenvalue and eigenvector attainment. The improvement is due to the coordinate system’s ability to accurately predict actuator boundary conditions and, thus, actuator command forces, when extensive model reduction has been employed. Two multi-input/multi-outputdesign examples are used to illustrate the practicality of the method and the resulting improved closed-loop behavior.