NUMERICAL CONTROLLER

• US 20180150050A1
• Filed: 11/29/2017
• Published: 05/31/2018
• Est. Priority Date: 11/29/2016
• Status: Active Grant

• Current Assignee: Fanuc Corporation
• Original Assignee: Fanuc Corporation
• Inventors: Kuroki, Hideki
• Granted Patent: US 10,642,246 B2
• Time in Patent Office: Days
• CPC Class Codes: G05B 19/402 characterised by control arrangements for positioning, e.g. centring a tool relative to a hole in the workpiece, additional detection means to correct position G05B19/19 takes precedence
• CPC Class Codes: G05B 19/404 characterised by control arrangements for compensation, e.g. for backlash, overshoot, tool offset, tool wear, temperature, machine construction errors, load, inertia G05B19/19, G05B19/41 take precedence
• CPC Class Codes: G05B 19/414 Structure of the control system, e.g. common controller or multiprocessor systems, interface to servo, programmable interface controller
• CPC Class Codes: G05B 19/4166 Controlling feed or in-feed G05B19/4163 takes precedence
• CPC Class Codes: G05B 2219/41428 Feedforward of position and speed
• CPC Class Codes: G05B 2219/41435 Adapt coefficients, parameters of feedforward

Abstract

A numerical controller is provided with a speed feedforward gain correction unit configured to obtain an associated axis, which is subject to a varying load applied to a particular axis according to a coordinate value, and a correction coefficient of the particular axis corresponding to the current coordinate value of the associated axis, based on a correction coefficient storage unit, and correct a speed feedforward gain for speed feedforward control of the particular axis, and a motor control unit configured to control the particular axis based on the corrected speed feedforward gain.

Claims

1. A numerical controller which controls a machine having a plurality of axes, the numerical controller comprising:

a correction coefficient storage unit stored with an associated axis, which is one of the plurality of axes for a predetermined or particular axis among the plurality of axes and is subject to a varying load applied to the particular axis according to the coordinate value of the axis concerned, and a correction coefficient corresponding to the coordinate value of the associated axis for correcting a speed feedforward gain for speed feedforward control of the particular axis, in association with each other;

a speed feedforward gain correction unit configured to obtain the correction coefficient of the particular axis corresponding to the current coordinate value of the associated axis, based on the correction coefficient storage unit, and correct the speed feedforward gain for the speed feedforward control of the particular axis by the obtained correction coefficient; and

a motor control unit configured to control the particular axis based on the corrected speed feedforward gain.

2. The numerical controller according to claim 1, further comprising an associated-axis registration unit configured to register the associated axis for the particular axis into the correction coefficient storage unit.

3. The numerical controller according to claim 1, further comprising a correction coefficient setting unit configured to set the correction coefficient corresponding to the coordinate value of the associated axis in the correction coefficient storage unit.

4. The numerical controller according to claim 3, wherein the correction coefficient setting unit commands the motor control unit to move the particular axis registered in the correction coefficient storage unit with the associated axis for the particular axis moved to a predetermined coordinate and obtains the correction coefficient in the predetermined coordinate for the associated axis by adjusting the speed feedforward gain of the particular axis while monitoring a feedback of the particular axis from the motor control unit.

5. The numerical controller according to claim 1, wherein the correction coefficient storage unit is registered with a plurality of associated axes for each single axis, and the speed feedforward gain correction unit obtains the correction coefficient based on the respective coordinate values of the plurality of associated axes registered for the particular axis and corrects the speed feedforward gain for the speed feedforward control of the particular axis by the obtained correction coefficient.