PURPOSE: To enable well-perspective modeling to be carried out by detecting the vibration of the 6-degree-of-freedom rigid body vibration system in or nearby the center of rotation and fixing dynamic elements in respective translational modes of three directions on the basis of the detection result.

CONSTITUTION: In a case wherein vibration sensors 23 for measurement are arranged at several positions shifted at right angles to their detection directions, the 6-degree-of- freedom rigid body vibration system 50 is excited by an actuator 11 which operates in the same directions as the respective detection directions and frequency characteristics of the 6-degree-of-freedom rigid body vibration system 50 are derived; and the point where it is most difficult to find the mode of the resonance angular vibration frequency of rotation vibration around the axis crossing the detection direction of a sensor 33 and a direction obtained by shifting the arrangement position of the sensor 23 is found, and the position O of the center of rotation of the 6-degree- of-freedom rigid body vibration system 50 is estimated. Then characteristics of a support mechanism 2 such as spring constants, damper attenuation coefficients, etc., of the translational modes of the respective (x), (y), and (z) directions are fixed on the basis of the estimation result of the position O of the center of rotation of the 6-degree-of-freedom rigid body vibration system 50.