Patent ID: 6701212
Filing Date: 2004-03-02
Classification: G05B

Abstract:
A lost motion correction method for a numerical control machine tool for correcting a lost motion error of a mechanical transmission system including a first mechanical element to be operated in accordance with a control command from a control program and a second mechanical element for positioning a control object to target positions, the lost motion correction method comprising:detecting an operated amount of the first mechanical element; detecting an operated position of the second mechanical element; recognizing from the control program that the control object stops at a first target position; calculating a stationary lost motion error as a lost motion error along a motion stop of the mechanical transmission system upon a positioning of the control object to the first target position, based on the operated amount of the first mechanical element and the operated position of the second mechanical element; setting a first lost motion correction value for canceling the stationary lost motion error; correcting, by the first lost motion correction value, a first control command for positioning the control object to the first target position; recognizing from the control program that the control object changes a moving direction at a second target position; calculating a dynamic lost motion error as a lost motion error along a continuous motion of the mechanical transmission system upon a positioning of the control object to the second target position, based on the operated amount of the first mechanical element and the operated position of the second mechanical position; setting a second lost motion correction value for canceling the dynamic lost motion error; and correcting, by the second lost motion correction value, a second control command for positioning the control object to the second target position.