Numerical controller

Patent metadata

Field	Value
Publication number	US-11126163-B2
Application number	US-202016902926-A
Country	US
Kind code	B2
Filing date	Jun 16, 2020
Priority date	Jun 19, 2019
Publication date	Sep 21, 2021
Grant date	Sep 21, 2021

Abstract

A numerical controller suppresses change of a axis speed to be slow even when a lookahead distance varies with small steps. The numerical controller includes: a lookahead unit that looks ahead a plurality of instruction blocks from an NC program; an analysis unit that analyzes the looked ahead instruction blocks and creates motion instruction data; a target speed calculation unit that calculates a target speed of the axis based on a lookahead distance; an interpolation unit that generates interpolation data based on the motion instruction data and the target speed; and a servo control unit that controls a motor based on the interpolation data. The target speed calculation unit refrains from recalculation of the target speed when a change of the lookahead distance is within a margin.

First claim

The invention claimed is:

1. A numerical controller that controls a machine tool based on an NC program, wherein the machine tool is adapted to drive an axis thereof to displace a tool relative to a workpiece and configured to machine the workpiece, the numerical controller comprising:
a lookahead unit that looks ahead a plurality of instruction blocks from the NC program;
an analysis unit that analyzes the plurality of instruction blocks looked ahead by the lookahead unit and creates motion instruction data for driving the axis;
a target speed calculation unit that calculates a target speed of the axis based on a lookahead distance through which the axis is to be moved in accordance with an instruction provided by the plurality of instruction blocks looked ahead by the lookahead unit;
an interpolation unit that generates interpolation data based on the motion instruction data and the target speed; and
a servo control unit that, based on the interpolation data, controls a motor configured to drive the machine tool,
wherein the target speed calculation unit refrains from recalculation of the target speed when the lookahead distance changes and the change of the distance is within a predetermined margin defined in advance.

Assignees

• Fanuc Corp

Inventors

• Koide Naoya
• Fujiyama Jirou

Classifications

• G05B2219/36521

  Select by combination of detected force, acceleration, speed, work rate · CPC title

• G05B19/416 Primary

  characterised by control of velocity, acceleration or deceleration (G05B19/19 takes precedence) · CPC title

• G05B19/4163 Primary

  Adaptive control of feed or cutting velocity (without NC B23Q15/12) · CPC title

• G05B19/41 Primary

  characterised by interpolation, e.g. the computation of intermediate points between programmed end points to define the path to be followed and the rate of travel along that path (G05B19/25, G05B19/31, G05B19/37, G05B19/39, G05B19/40 take precedence) · CPC title

• G05B2219/34095

  Look ahead segment calculation · CPC title