Patent ID: 7774087

Claim:
A crane deformation compensating method for a wire electrical discharge machine is provided, comprising the steps of: a providing a wire electrical discharge machine configured with a movable crane; a measure unit, mounted on the crane for measuring the deformation of the same; and a control unit, electrically connected to the measure unit and used for controlling the crane to move; b using the measure unit to measure a deformation of the operating crane and thus generating a deformation signal accordingly; c enabling the control unit to receive the deformation signal and thereafter obtain a position error of the crane by referencing the deformation signal to a lookup table describing the relation between the crane's deformation and position error, wherein the lookup table is formed by the steps of: (a1) exerting a plurality of force of different magnitudes upon the crane for causing the same to generate a plurality of deformation accordingly and thereafter registering a plurality of position errors of the crane in correspondence to the plural deformations; (a2) enabling the measure unit to generate a plurality of deformation signals in correspondence to the plural deformations; and (a3) enabling the control unit to form a lookup table describing the relation between the crane's deformations and the position errors; and d enabling the control unit to perform a feedback displacement control according to the obtained position error.