Hydraulic servo control method and hydraulic servo control device

摘要

PROBLEM TO BE SOLVED: To provide a method and a device for controlling a hydraulic servo which can model a hydraulic cylinder, hardly generating an error, and can control the hydraulic force to a target value.SOLUTION: A hydraulic cylinder 10 is modeled by defining the mass of an upper piston 11 positioning on a side to be controlled in two pistons as m, the mass of a lower piston 12 to be used for a servo as m, a spring constant of an oil column of the upper piston 11 on a lower piston 12 side thereof as k, a spring constant of an oil column of the upper piston 11 on a side to be controlled as k. In the case wherein both of the upper piston 11 and the lower piston 12 displace in the same direction, when the displaced amount of the upper piston 11 is equal to the displaced amount of the lower piston 12 or more, a load to be applied to the upper piston 11 is estimated based on a spring model using the only spring constant k, and when the displaced amount of the upper piston 11 is less than the displaced amount of the lower piston 12, a load to be applied to the upper piston 11 is estimated based on a spring model using the only spring constant k.