GB2187308A

GB2187308A - An operation program checking method for a numerical control device

Info

Publication number: GB2187308A
Application number: GB08704516A
Authority: GB
Inventors: Yukari Tsubaki
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 1986-02-27
Filing date: 1987-02-26
Publication date: 1987-09-03
Anticipated expiration: 2007-02-26
Also published as: GB8704516D0; GB2187308B; DE3706291A1; JPS62198906A

Abstract

The method includes reading and storing an operation program and acted objective program, e.g. information about a workpiece by a program read storage element, reading the two programs stored in the element by a read-arithmetic element; and analyzing the two programs and simultaneously and comparatively displaying the locus of the controlled system and information indicating the position and shape of the acted object on the display screen. Thus, the operation program for controlling the controlled system is checked visually on the display screen. The controlled system may be a tool set on a machine tool e.g. drilling, grinding, thread cutting, the arm of an industrial robot or an automatic assembling machine. <IMAGE>

Description

SPECIFICATION Operation program checking method for a numerical control device BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an operation program checking method for a numerical control device and, more specifically, to an operation program checking method of checking an operation program for controlling a tool, such as a drill, set on a controlled machine tool, by displaying the machining route or locus of the cutting edge of the tool on a display means.

Description of the Prior Art Generally, the numerical control device is applied to various fields of manufacturing technology, such as those of industrial robots, automatic assembling machines and automatic drafting machines, including the field of machine tools for cutting-off, cutting, drilling, thread cutting and grinding. The numerical control device is applied mainly to the automatic control of the machine tool or the like. The numerical control device controls the operation of the machine by giving numerical information corresponding to the quantity of motion of the machine, such as the angle of rotation and the distance of travel. Recently, the development of computer technology and digital technology has brought about remarkable progress in the composition of machining programs, the execution of control programs and the control of driving systems.

A machining program for controlling a controlled system by predetermined numerical information is composed for the numerical control device, and the machining program is checked in the following procedure.

Fig. 1 is a front elevation of the display screen of a visual display device for checking the machining program for a conventional numerical control device. In Fig. 1, indicated at 1 is display screen, at 2 is the route of a cutting edge displayed on the display screen 1 by analyzing the following machining program I.

Machining program I:

The checking procedure of a machining program checking means will be described hereinafter.

The machining program checking means for checking the machining program I comprises, as the principal components, a read unit, an arithmetic unit, and a display unit. The machining program I is read by the read unit and is stored in a memory, and then the machining program is analyzed by the arithmetic unit. When the movement with respect to the axes is controlled by commands of the incremental system, the movement commands of the absolute system are converted into those of the incremental system. That is, the commands of the machining program I are analyzed sequentially to determine the direction and distance of movement from the current position to the next position. The results of the analysis are displayed as the route 2 of the cutting edge on the display screen 1.

The conventional machining program checking method for a numerical control device dispiays only the route 2 of the cutting edge on the display screen 1. Accordingly, it is impossible to recognize the position of the cutting edge relative to the workpiece visually, and hence it is possible, in the actual machining operation, that faulty machining attributable to a wrong machine ing program, such as the movement of the cutting edge to a position where no workpiece is placed or the excessive feed of the cutting tool, occurs.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an operation program checking method which enables the visual confirmation of the positional relation between a shape in which a workpiece is to be machined and a route along which the cutting edge of a tool is to be moved, to check an operation program defining the route of movement of a controlled system, such as a tool, so that the route of movement of the controlled system coincides accurately with the shape in which the workpiece is to be machined.

To achieve the object of the invention, according to the present invention, an operation program is checked by an operation program checking method for a numerical control device by storing an operation program and a workpiece shape program indicating the shape of a controlled object, i.e., a workpiece, in the storage device of a numerical control unit, reading both the programs by the arithmetic unit of the numerical control unit, analyzing both the programs by the arithmetic unit, and simultaneously and comparatively displaying the locus of the tool and the shape of the controlled object, i.e., the workpiece, on a display screen.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a front elevation of assistance in explaining a conventional machining program checking method for a numerical control unit, showing a display screen displaying the locus of a tool; Figure 2 is a front elevation of assistance in explaining a machining program checking method for a numerical control unit, according to the present invention, showing a display screen displaying both the locus of a tool and the shape of a workpiece; and Figure 3 is a block diagram showing the algorithm of an operation program checking method for a numerical control unit, according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An operation program checking method for a numerical control unit, in a preferred embodiment, according to the present invention, as applied to the numerical control unit of a machine tool for cutting, will be described hereinafter with reference to the accompanying drawings.

Fig. 2 is a front elevation of a display screen displaying the results of check of an operation program, i.e., a machining program, by a checking method according to the present invention. In Fig. 2, there are shown the display screen 1 of a display unit, the route, i.e., the locus, 2 of the cutting edge of a tool obtained through the analysis of a machining program I, and a workpiece shape 3 obtained through the analysis of a workpiece shape displaying program II.

Machining program I:

Workpiece shape displaying program II:

The algorithm of the checking method will be described hereinafter with reference to Fig. 3.

First, the machining program I is composed in the conventional manner, and the workpiece shape displaying program II also is composed. The two programs I and II are read by a readstorage unit 5 and are stored in the storage device, not shown, of the read-storage unit 5.

The process executed by the arithmetic unit 8 includes an additional selection process 6 for selecting either the machining program I or the workpiece shape displaying program II. An input 7 for selecting the display of either the workpiece shape 3 or the route 2 of the cutting edge needs to be given by means of an input device, not shown.

For example, when both the route 2 of the cutting edge and the workpiece shape 3 are required to be displayed as illustrated in Fig. 2, first, an input 7 requesting the display of the workpiece shape 3 is given, and then the arithmetic unit 8 selects the workpiece shape display ing program II and analyzes the same to obtain moving command data. Then, the display unit 9 displays the workpiece shape 3 on the display screen 1 on the basis of the moving command data. The moving command data must be effective only for display and must be irrelevant to actual machining operation.

Then, an input 7 requesting the display of the route 2 of the cutting edge is given. Then, the arithmetic unit 8 selects the machining program 1, and then obtains moving command data for the machining program I to display the route 2 of the cutting edge.

Thus, the workpiece shape 3 and the route 2 of the cutting edge simultaneously displayed on the display screen 1 are compared to check whether or not the machining program I is correct.

According to the present invention, since the information of the objective of action, namely, the workpiece shape, is displayed together with the locus of the controlled system, namely, the route of the cutting edge, the positional relation between the workpiece and the route of the cutting edge can visually be recognized, and thereby fault in the machining program, such as moving the cutting edge to a position where no workpiece is placed, can be found on the display screen.

The read unit for reading the two programs and the arithmetic unit for reading and analyzing the stored programs of this embodiment may be substituted by a central processing unit (hereinafter abbreviated to "CPU") including a microcomputer or the like, and the abovementioned predetermined operation may be executed by operating an input device for operating the CPU.

Furthermore, although the present invention has been described as applied to the numerical control unit for controlling a NC machine tool for cutting, the present invention is not limited to such an application, but may be applied, for example, to NC machine for other machining, such as cutting-off, thread cutting or grinding. Still further, the application of the present invention is not limited only to NC machine tools; the present invention is applicable also to other various manufacturing machines and equipments which are controlled numerically, such as industrial robots, automatic assembling machines and automatic drafting machines.

As apparent from what has been described hereinbefore, according to the present invention, since the workpiece shape is displayed on a display together with the route of the cutting edge, the visual check of the machining program is possible. Accordingly, errors in the machining program which cause faulty machining operation are found at the stage of operation program checking. Thus, the present invention eliminates loss time in the machining process and prevents wasting material due to faulty machining.

Claims

1. An operation program checking method for a numerical control device, for checking an operation program by displaying the locus of a controlled system the movement of which is controlled according to the operation program on the display screen of a display means, which comprises; a first step of writing the operation program and an acted objective program including various information of the controlled system, namley, an acted objective, by a write-storage means of the numerical control device; a second step of reading both the programs processed by the write-storage means at the first step, by an arithmetic means of the numerical control device; and a third step of analyzing both the programs read by the arithmetic means, and simultaneously and comparatively displaying the locus of the controlled system and information indicating the position and shape of the acted objective on the display screen.

2. An operation program checking method as recited in claim 1, wherein a read-write unit included in the storage unit of said write-storage means executes said first step of writing the operation program and the acted objective program by reading both the programs from said numerical control device and writing the same in said storage unit, and both the programs are stored in said storage unit.

3. An operation program checking method as recited in claim 1, wherein said arithmetic unit for reading and analyzing said two programs is a central processing unit (CPU) including a microcomputer, said write-read unit of said write-storage means is included in the CPU, and said steps of a pedetermined program checking procedure are executed by giving commands by means of the input device of the CPU.

4. An operation program checking method as recited in claim 1, wherein said numerical control device which executes the program checking procedure is incorporated into a numerical control (NC) machine tool capable of various machining operations, such as a machining center, and checks various machining programs by comparatively displaying the various machining programs and a program defining the position and shape of the workpiece to be machined, on the display screen.

5. An operation program checking method as recited in claim 1, wherein said numerical control device which executes the program checking procedure is incorporated into an industrial robot, and a robot work program, namely, the operation program, is checked by comparatively displaying the robot work program and a program defining the position and shape of the objected of the robot work on the display screen.

6. An operation program checking method as recited in claim 1, wherein said numerical control device which executes the program checking procedure is incorporated into an automatic assembling machine, and an assembling program, namely the operation program, of the automatic assembling machine is checked by comparatively displaying the assembling program and a program defining the position and shape of a machine to be assembled, namely, the objective of the assembling operation of the automatic assembling machine, on the display screen.

7. An operation program checking method as recited in claim 1, wherein said numerical control device which executes the program checking procedure is incorporated into an automatic drafting machine, and a drafting program of the automatic drafting machine, namely, the operation program, is checked by comparatively displaying the drafting program and a program defining the shape and size of a drafting paper on which the automatic drafting machine draws a diagram, on the display screen.