Time domain estimation of excitation forces for mechanical structures by Kalman filter

(Application to model of 5 degrees of freedom system)

Abstract

This paper is concerned with estimation of non-stationary excitation forces by the augmented Kalman filter. To reduce vibration and noise, it is important to grasp excitation forces for machines in operation. When excitation forces can not directly acquired, an indirect procedure is necessary to estimate inputs from vibration responses. The indirect estimation procedures are generally classified the estimation in frequency domain and in time domain. Especially, the time domain procedures are suitable to estimate non-stationary excitation forces. In this paper, we deal with the impulse forces of the 5 degree of freedom system as the non-stationary input. The augmented state system is considered with the state vector which consists of displacements velocities and excitation forces. Then the impulse forces are estimated by the augmented Kalman filter with acceleration responses. The estimation experiments for various sampling times are carried out to consider estimation performance.