ORIGIN RETURN DEVICE FOR VIBRATION-ISOLATED STRUCTURE BUILDING

摘要

PROBLEM TO BE SOLVED: To provide an origin return device accurately correcting the displacement of the place of a building at a low cost when the place of the building supported through a vibration isolation layer having hysteretic characteristics is displaced by an earthquake or the like. SOLUTION: The origin return device is composed of a displacement detector 4 detecting the place to the origin of the building, hydraulic cylinders 11 displacing the building to a ground, an on-off valve 13 changing over the supply or discharge of oil pressure to or from the hydraulic cylinders 11, a controller 5 setting a place at a nearer distance from the origin than the current place of the building at the aimed place of the building and setting a command value corresponding to the aimed place and a servo amplifier 3 outputting a time proportional to the magnitude of a deflection between the command value and the current place of the building and signals driving the hydraulic cylinders 11 in the direction that the deflection is reduced.