Numerical controller

• US 11,281,187 B2
• Filed: 10/22/2019
• Issued: 03/22/2022
• Est. Priority Date: 10/31/2018
• Status: Active Grant

• Current Assignee: Fanuc Corporation
• Original Assignee: Fanuc Corporation
• Inventors: Uenishi, Daisuke, Tango, Chikara
• Primary Examiner(s): Jarrett, Ryan A
• Application Number:
  US16/660,710
• Publication Number:
  US 20200133240A1
• Time in Patent Office: 882 Days
• Field of Search: None
• CPC Class Codes: N/A

Abstract

To provide a numerical controller that can detect a position in a machining program at which a speed control abnormality is likely to occur due to an insufficient look-ahead blocks that are used to determine an acceleration/deceleration operation, and supplement the look-ahead blocks at that position in order to stabilize feed rate, cutting speed and other factors. A numerical controller includes a required look-ahead blocks setting unit that sets a required look-ahead blocks, which is a look-ahead blocks required to execute a machining program, and an operation limitation unit that compares a look-ahead blocks calculated by a look-ahead blocks calculation unit to the required look-ahead blocks and, if the look-ahead blocks is less than the required look-ahead blocks, limits execution of the machining program until the look-ahead blocks reach the required look-ahead blocks.

Claims

1. A numerical controller for controlling a machine tool that has axes by executing a machining program that is made up of a plurality of blocks and controls acceleration/deceleration of the axes, the numerical controller comprising:

a program execution unit that executes the machining program;

a program look-ahead unit that looks ahead at the machining program in parallel with execution of the machining program;

a look-ahead blocks calculation unit that calculates a look-ahead blocks, which is the difference between a first sequence number that is the number of a block being executed by the program execution unit and a second sequence number that is the number of a block that is looked ahead by the program look-ahead unit while the machining program is being executed;

a required look-ahead blocks setting unit that sets a required look-ahead blocks, which is the look-ahead blocks required to execute the machining program; and

an operation limitation unit that compares the look-ahead blocks calculated by the look-ahead blocks calculation unit and the required look-ahead blocks and, if the look-ahead blocks is less than the required look-ahead blocks, limits execution of the machining program by the program execution unit until the look-ahead blocks reaches the required look-ahead blocks.

2. The numerical controller according to claim 1, further comprising a storage unit that stores blocks that are looked ahead by the program look-ahead unit, where the stored blocks are consumed by the program execution unit,

wherein the required look-ahead blocks setting unit sets the required look-ahead blocks on the basis of maximum capacity of the storage unit.

3. The numerical controller according to claim 1, further comprising a storage unit that stores the required look-ahead blocks,

wherein the required look-ahead blocks setting unit sets the required look-ahead blocks using the required look-ahead blocks stored the storage unit.

4. The numerical controller according to claim 1, wherein the required look-ahead blocks setting unit sets the required look-ahead blocks on the basis of a variable that is written in the machining program together with a predetermined first code.

5. The numerical controller according to claim 1,

wherein, the machining program contains an iteration of a second code that corresponds to identical machining,

the numerical controller further comprising a storage unit that stores a number of consumed blocks that is the look-ahead blocks consumed when the second code was previously executed by the program execution unit, and

the required look-ahead blocks setting unit setting, as the required look-ahead blocks, a value in which the number of consumed blocks is added to the look-ahead blocks before the code is executed when the code is executed next or for subsequent times by the program execution unit.

6. The numerical controller according to claim 1, wherein the operation limitation unit instructs the program execution unit to stop executing the machining program.

7. The numerical controller according to claim 1, wherein the operation limitation unit reduces operation speed of the machine tool specified in the machining program.

8. The numerical controller according to claim 1, further comprising a supplement code addition unit that detects a block in the machining program at which the look-ahead blocks calculated by the look-ahead blocks calculation unit falls below a prescribed value when a simulation of the machining program is executed, and inserts a predetermined third code in the block,

wherein, when the third code is detected, the operation limitation unit compares the look-ahead blocks and the required look-ahead blocks.