JPH03167603A - Pre-read controller for nc program - Google Patents

Abstract

PURPOSE:To suppress the increase of the memory using frequency and to reduce the processing time of the numerical data by compressing, saving and restoring the changing extent of the pre-read numerical data during a correction mode. CONSTITUTION:A conversion means 2 reads a block 11a of a working program 1. When the block 11a is not equal to the end of an NC program, a program written into the block 11a is analyzed and converted into the numerical data. This data is stored in a numerical data buffer 31a of a buffer 3. A CPU 4 decides whether the stored block 11a is kept in a correction mode or not. If a correcting calculation is not finished yet and the stored data requires no compressing/saving process, a pre-read operation is required for execution of the correcting calculation. In such a case, the reading position of the program 1 is advanced to the next block 11b. Then the data is stored in a buffer 31b and compared with the data stored in the buffer 31a, and a changing extent produced between both data is stored in a changing extent store buffer 6. This operation is repeated for execution of the correcting calculations with use of those data stored in the buffers 31a - 31c.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a read-ahead control device that reads in advance multiple blocks of an NC program read into a numerical control device and stores them in memory, and particularly relates to a reduction in memory usage. It is.

[Prior Art] In order to improve the processing speed of a numerical control device, an NC program is created in which a fetch cycle for reading a machining program overlaps an execution cycle so that the time required for the fetch cycle can be effectively ignored. Look-ahead control has traditionally been performed.

FIG. 4 is a schematic diagram showing prefetch control of a conventional NC program. In the figure, <l> represents a plurality of blocks (ll
a) NC program with ~(lLn), (2) is N
Each block (lla) to (fin) of C program (1)
) into numerical data;
(3) is seven columns of pre-read numerical data buffers provided in the storage means, and the pre-read numerical data buffer column (3) contains each block (ll
It has pre-read numerical data buffers (31a) to (31n) that store numerical data of a) to (fin), respectively.

Next, the prefetch control of the NC program configured as described above will be explained with reference to the flowchart of FIG.

First, the numerical data conversion means (2) is used to convert the NC program (1
) is read (step S5l).
, it is determined whether the block (lla) is the NC program end (step S52). If the read block (lla) is not at the end of the NC program, the program written in the read block (lla) is analyzed and converted into numerical data, and the converted numerical data is sent to the pre-read numerical data buffer 7 columns (3> (Step S53)
.

Next, from the contents of the pre-read numerical data stored in the pre-read numerical data buffer (31a), it is determined whether or not further pre-reading of the NC program (1) is necessary (step S54).
). , NC program (1) when pre-reading is required.
The reading position is advanced to the next block (Llb) (step S55), and the next block (llb) is read (step S51). Thereafter, each block (lie) to (lln) that requires pre-reading is sequentially read in the same manner, and pre-read numerical data corresponding to each block is created and stored in the pre-read numerical data buffers (3lb) to (31n), respectively.

When the pre-reading of the NC program (1) becomes unnecessary, tool movement data is created by a machine control means (not shown) using the pre-read numerical data stored in the pre-read numerical data buffer 7 column 3) (step 35B), The tool movement data is output and the tool is moved to perform machining (step S57).

The above processing is repeated until the program end of the NC program <1) is reached, and the process ends when the NC program end is reached.

[Problems to be Solved by the Invention] Since the look-ahead control of the conventional NC program is configured as described above, when trying to increase the number of look-ahead blocks of the NC program (1), the number of look-ahead numerical data buffers (7 columns (3)) Prefetch numerical data buffer (31.a) to (3
1n), the amount of memory used by the storage means increases, and the cost of the numerical control device increases.

This invention was made in order to solve such problems, and it is possible to suppress the increase in memory usage as much as possible even if the number of read-ahead blocks of the NC program is increased, and the numerical value of each block of the NC program can be kept as small as possible. The object of the present invention is to provide a prefetch control device for an NC program that can reduce processing time for storing and retrieving data from a storage means.

[Means for Solving the Problems] The NC program lookahead control device according to the present invention includes a plurality of lookahead numerical data buffers for storing lookahead numerical data of each block of the NC program and a change storage buffer 7 in a storage means. The data is stored in multiple consecutive prefetch numerical data buffers by the storage processing means. Compare each look-ahead numerical data that has been read, and compare the previous block's numeric data. The change in the pre-read numerical data of the subsequent block with respect to the pre-read numerical data is extracted, compressed, and stored in a change storage buffer. The pre-read numerical data in the pre-read numerical data buffer from which this change has been extracted is invalidated by the invalidation processing means, and the pre-read numerical data buffer is made an empty buffer.

When retrieving the look-ahead numerical data that has been invalidated by the invalidation processing means, the restoration processing means uses the look-ahead numerical data of the previous block stored in the look-ahead numerical data buffer and the changed value stored in the change storage buffer to retrieve the invalidated numerical data. Restore and retrieve the look-ahead numerical data.

Further, it is preferable that the compression/save processing for the change in the pre-read numerical data of the subsequent block in the storage processing means is performed during a correction mode in which the NC program command of the previous block is corrected by the command correction amount.

[Operation] In this invention, each of the pre-read numerical data stored in the pre-read numerical data buffer of a plurality of consecutive blocks of the NC program is compared, and the change in the pre-read numerical data of the subsequent block with respect to the pre-read numerical data of the previous block is calculated. is extracted, compressed, and stored in a change storage buffer, and after the change is stored in the change storage buffer, the pre-read numerical data of the block is invalidated in the pre-read numerical data buffer.

Then, the next block's pre-read numerical data is stored in this pre-read numerical data buffer. By repeating this process, the amount of use of the prefetch numerical data buffer is suppressed.

Furthermore, the pre-read numerical data of the subsequent block that has been invalidated in the pre-read numerical data buffer is sequentially restored and retrieved using the pre-read numerical data of the previous block and the change stored in the change storage buffer.

By executing the compression, saving, and restoration processing for changes in this look-ahead numerical data during the correction mode where look-ahead may occur frequently, compression processing etc. can be performed during the non-correction mode where look-ahead does not occur frequently. To prevent required overhead processing time from being added to processing time.

[Example Figure 1 is here. 4 is a block diagram showing an embodiment of the invention, and in the figure, 1) to 3) indicate exactly the same thing as the schematic diagram of the conventional example shown in FIG. 4. FIG. (4) is a central processing unit that explains and executes instructions, (5) is a storage means, and as shown in the schematic diagram of Fig. 2, each block of the NC program (1) is stored in the storage means (5). numeric data conversion means (2
), a read-ahead numerical data buffer array (3) consisting of a plurality of read-ahead numerical data buffers (hereinafter referred to as numerical data buffers) (31a) to (31c) that sequentially store numerical data pre-read converted, and a change storage buffer (6). ).

(A) is a storage processing means, and the storage processing means (7>) is a plurality of consecutive numerical data buffers (31a) to (31.
Compare the look-ahead numerical data (hereinafter referred to as numerical data) sequentially stored in c), extract and compress the change in the numerical data of the subsequent block with respect to the numerical data of the previous block, and use the data of the compressed change as the change. Save buffer (6)
Store in. Numeral (8) is an invalidation processing means, and the invalidation processing means (8) invalidates the numerical data in the numerical data buffer from which the change has been taken out, and makes this numerical data buffer an empty buffer.

(9) is a restoration processing means, and the restoration processing means (9) stores the numerical data of the invalidated block into the numerical data stored in the look-ahead numerical data buffer column (3) and the change storage buffer (6). Restore and output from the stored change data.

(10) is a mechanism control means, and a mechanism control means ({0)
creates tool movement data and machine sequence data from the pre-read numerical data sent from the pre-read numerical data buffer 7 column (3) or the restoration processing means (9).

Next, the operation of the NC program prefetch control device configured as described above will be explained with reference to the schematic diagram shown in FIG. 2 and the flowchart shown in FIG. 3. In the schematic diagram of FIG. 2, (301) indicates the restored pre-read numerical data string.

In the look-ahead control device configured as described above, first block 1 of the machining program (1), lock (lla), is read by the numerical data conversion means (2) (step S31),
It is determined whether the block (11.a) is the end of the NC program (step S32).

If the read block (lla) is not at the end of the NC program, the program written in this block (lla) is analyzed and converted into numerical data, and the converted numerical data is stored in the pre-read numerical data buffer column (3). It is stored in the numerical data buffer (31a) (step S33).

Next, the central processing unit (4) determines whether or not the block (lI.a) stored in the numerical data buffer (31a) is in the correction mode (step S34), and determines whether the block (lI.a) is in the correction mode or not and performs correction calculation. is not completed (step S3).
5, 836), it is determined whether the numerical data stored in the numerical data buffer (31a) is of a type that requires compression and saving (step S37), and if it does not require compression and saving, correction calculation is performed. In order to perform this, it is determined whether or not further pre-reading of the NC program (1) is necessary (step 838), and if pre-reading is necessary, the reading position of the NC program (1) is advanced to the next block (flb) (step S39). ).

After that, the numerical data converting means (2) again reads the next block (llb> (step S31), and if that block (llb) is not the end of the NC program, converts the program into numerical data, and converts the program into the numerical data buffer (step S31).
3lb) (step 833).

When the block (llb) stored in this numerical data buffer (8lb) is in the correction mode and the correction calculation is not completed (steps 334 to S36), the numerical data stored in the numerical data buffer (3lb) is compressed. It is determined whether the object is of a type that requires evacuation, such as a non-moving block during tool radius correction calculation (step S).
37) If the data requires compression and saving, compare the numerical data in the numerical data buffer (3lb) with the numerical data stored in the previous numerical data buffer (31a), extract the changes, and compress. and save the change buffer (
6), invalidates the contents of the numerical data buffer (3lb), and makes space available for pre-reading of the next block (lie) (step S40).

Here, the comparison between the numerical data of the numerical data buffer (3lb) and the numerical data of the previous numerical data buffer (31a) is performed for each numerical data buffer (3lb), (31a).
) regardless of the contents of the two numeric data buffers <3
lb). Compare the contents of (31 a) in fixed length units from the beginning, and store the changes in fixed length units in the change storage buffer (6>). Conversely, when extracting the changes from the change storage buffer (8) is also extracted in fixed length units.

The change storage buffer (6) has a ring buffer structure, and changes are stored and retrieved in multiplexed format by comparing ring numbers.

Next, it is determined whether or not pre-reading of the NC program (1.) is necessary to perform correction calculations, and if pre-reading is necessary, N
The next block (1 1c) of the C program (1) is read (Step 1 S33. S39. S31).

The numerical data of the read block (lie) is stored in the previously vacated numerical data buffer (3lb) (step S
33). Thereafter, create numerical data corresponding to the look-ahead block of the NC program (1) in the same way, and save only the numerical data that will not be compressed and saved to the numerical data buffer 7 (31a).
~(31c).

In the schematic diagram of FIG. 2, blocks (lla), (lie) . (llf) indicates a block that is not compressed and saved, and block (llb)
．． A case is shown in which the changes in numerical data of (lid) and (JIe) are compressed and saved in the change storage buffer (6>).

When performing a correction calculation to correct the NC program command by the command correction amount, the correction calculation is performed using the numerical data stored in the numerical data buffers (31a) to (31c) to be corrected (step S35). ).

This correction calculation is completed (step S36), or N
When pre-reading of the C program (1) is no longer necessary (step 838), the restoration processing means (9) sequentially reads numerical data (3) from the first numerical data buffer (31a).
2a) to (331') are taken out and the mechanical control means (lO
), the machine control means (10) creates tool movement data (step S41), and outputs the tool movement data to perform machining (step S42).

At this time, for example, in order to restore the numerical data of the compressed and saved block (llb) of the NC program (1) (step S43), it is necessary to restore the numerical data compressed and saved in the change storage buffer (6). , the numerical data (32b) before being compressed and saved is restored and extracted from the numerical data in the numerical data buffer (31a) compared earlier (step S44).

This process is performed sequentially to obtain numerical data (32a) for each block (lla) to (llf) of the NC program <1).
~(32r) is extracted as shown in the numerical data string (301).

Note that in the above embodiment, the numerical data buffer string (
3) into three numerical data buffers (31a) to (31c).
), the number of numerical data buffers can be selected to any desired number depending on the amount of memory used.

[Effects of the Invention] As described above, the present invention compares each piece of pre-read numerical data stored in the pre-read numerical data buffer of a plurality of consecutive blocks of an NC program, and compares the pre-read numerical data of the subsequent block with the pre-read numerical data of the previous block. The changes in the numerical data are extracted, compressed, and stored in the change storage buffer, and after the changes are compressed and saved in the change storage buffer, the pre-read numerical data of the block is stored in the pre-read numerical data buffer. Since the next block's read-ahead numerical data is stored in this read-ahead numerical data buffer, the amount of use of the read-ahead numerical data buffer can be kept small, so even if the number of read-ahead blocks in the NC program increases, it will not be stored. There is no need to increase the usage of the device, and the cost of the storage device can be reduced.

In addition, by compressing and saving the changes in the look-ahead numerical data to the change storage buffer and taking them out during the NC program's look-ahead or frequently occurring correction mode, the look-ahead value can be saved during the non-correction mode where look-ahead does not occur often. Since the overhead processing time required for compressing, saving and restoring data changes is not added to the actual processing time, it is possible to prevent an increase in the processing time of the entire numerical control device.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a schematic diagram explaining the operation of the above embodiment, Fig. 3 is a flowchart showing the operation procedure of the above embodiment, and Fig. 4 is a conventional example. The schematic diagram shown in FIG. 5 is a flowchart showing the operating procedure of the conventional example. (1)...Machining program, (2>...Numeric data conversion means, (3)...Ahead-read numerical data buffer string,
(4)...Central processing means, (5)...Storage means, (
6) Change storage buffer, (a) Storage processing means, (8) Invalidation processing means, H9) Restoration processing means, (10> Machine control means, (1.1a) ~
(lln>...NC program block, (31a
)~(3tn)...Pre-read numerical data buffer. f; The same reference numerals in the figures indicate the same or corresponding parts.

Claims (2)

[Claims] (1) A numerical data conversion means reads in advance a plurality of blocks of the NC program, converts it into numerical data for each block, and stores the converted read-ahead numerical data of each block in a plurality of read-ahead numerical data buffers provided in a storage means. N.C.
In a program read-ahead control device, a change storage buffer provided in a storage means is compared with each read-ahead numerical data stored in a plurality of consecutive read-ahead numerical data buffers, and the read-ahead numerical data of a subsequent block is compared with the read-ahead numerical data of a previous block. storage processing means for extracting and compressing changes in numerical data and storing the compressed data in the change storage buffer; and invalidation of the look-ahead numerical data buffer from which changes have been taken out by the storage processing means to invalidate the read-ahead numerical data and make the buffer empty. An NC program comprising: a processing means; and a restoration processing means for restoring the look-ahead numerical data invalidated by the invalidation processing means from the look-ahead numerical data of the previous block and changes stored in a change storage buffer. Look-ahead control device. (2) The storage processing means is operated during a correction mode in which the NC program command is corrected by the command correction amount, and when multiple read-ahead is performed, changes in the read-ahead numerical data of each block that is not subject to correction are compressed and changed. 2. The NC program prefetch control device according to claim 1, wherein the NC program is stored in a minute storage buffer.