Modal computing method of output feedback control gain matrix in pole assignment of vibration system

Modal computing method of output feedback control gain matrix in pole assignment problem is addressed by using modal coordinates. It is of obvious advantage to save computing time and protect some methods from invalidity for high order structure. The numerical example of a cantilever beam is presented. The output feedback gains are computed by using original structural state space equation and four-order state space equation of modal coordinates for first two eigenvalue assignment of original structure, respectively, and then apply those gains obtained under modal coordinates to original structural state space equation. Comparing the control effect of Modal gains with one of original gain, it is verified that modal computing method is available.