JP2010198380A - Processing apparatus, processing method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To more reliably prevent stop between blocks without increasing processing time. <P>SOLUTION: A processing apparatus for processing a numerical control program including a plurality of continuous blocks to regulate a moving locus of a tool includes: an operation means for calculating the moving quantity of the tool when each block is executed; and a conversion means which, when the moving quantity calculated by the operation means is less than a prescribed moving quantity, converts a plurality of blocks which are the plurality of continuous blocks including the block concerned and having the total quantity of the moving quantities equal to or larger than the prescribed moving quantity, into one new block for prescribing a moving locus approximated to the moving locus of the tool which is regulated by the blocks. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a numerical control technique for a machine tool.

  A numerical control device is used to control the operation of the machine tool. In the control by the numerical control device, a numerical control program in which operation commands called blocks are sequentially described is created. The numerical control device that has read this numerical control program controls the machine tool to perform a desired operation. When complex and various machining shapes are performed, the machining shape may be expressed by a series of minute linear interpolations of several hundred microns or less. In such a case, a plurality of blocks that define a minute movement amount of the tool are continuous. Then, the control command to the machine tool defined by the previous block ends before the next block arrives, and a so-called inter-block stop may occur in which the machining operation that should be performed continuously stops.

  In order to avoid a stop between blocks, Patent Document 1 discloses that a block defining a minute movement amount is connected to a block immediately before or immediately after and is a new block. In Patent Document 2, the allowable feed speed of the tool is calculated from the average block length of a plurality of consecutive blocks, and when the feed speed of the tool in each block is larger than the allowable feed speed, the feed speed is set to the allowable speed. In order to avoid block-to-block stops.

JP-A-6-309025 JP 2000-267718 A

  However, as described in Patent Document 1, even when a block that defines a minute movement amount is connected to a block immediately before or immediately after, a movement amount defined by a new block may still be minute. There may be an outage. Further, as described in Patent Document 2, there is a problem that if the feed rate of the tool is reduced, the machining time becomes longer.

  An object of the present invention is to more reliably avoid a stop between blocks without prolonging the processing time.

  According to the present invention, there is provided a processing device, a processing method, and a program for more reliably avoiding a stop between blocks without prolonging the processing time. For example, the processing apparatus of the present invention is a processing apparatus that processes a numerical control program including a plurality of consecutive blocks that defines a movement trajectory of the tool, and the amount of movement of the tool when each of the blocks is executed. A calculation means for calculating, and when the movement amount calculated by the calculation means is less than a prescribed movement amount, a plurality of blocks including the block that are continuous, the total amount of the movement amounts being the prescribed amount Conversion means for converting the plurality of blocks that are equal to or greater than the movement amount into a new block that defines a movement locus that approximates the movement locus of the tool defined by these blocks.

  According to the present invention, stoppage between blocks can be avoided more reliably without prolonging the processing time.

1 is a block diagram of a system using a numerical control device A according to an embodiment of the present invention. (A) is explanatory drawing of a numerical control program, (b) is explanatory drawing of conversion of a block. It is a flowchart which shows the example of the process which the process part 11 performs. (A) is explanatory drawing of the error of the movement locus | trajectory of the tool accompanying conversion of a block, (b) is explanatory drawing of block conversion which considered the error of the movement locus | trajectory. It is a flowchart which shows the example of the process which the process part 11 performs. It is a flowchart which shows the example of the process which the process part 11 performs. It is a flowchart which shows the example of the process which the process part 21 performs. It is a block diagram of the system using the numerical control apparatus B which concerns on other embodiment of this invention. It is a flowchart which shows the example of the process which the process part 41 performs.

<First Embodiment>
FIG. 1 is a block diagram of a system using a numerical controller A according to an embodiment of the present invention. The numerical controller A receives the numerical control program transmitted from the CAD / CAM device 1 and outputs a control command to the machine tool 2 based on the received numerical control program. The CAD / CAM device 1 is, for example, a computer that executes CAD / CAM software, and generates a numerical control program. The machine tool 2 is a milling machine or a lathe.

  The numerical control device A includes a preprocessing unit 10, a numerical control unit 20, an input device 31, a display device 32, and a drive circuit 33. The preprocessing unit 10 and the numerical control unit 20 include processing units 11 and 21, storage units 12 and 22, and interface units 13 and 23, respectively. The numerical control unit 20 further includes a buffer unit 24.

  The processing units 11 and 21 are CPUs or the like that execute programs stored in the storage units 12 and 22. The storage units 12 and 24 are storage devices such as RAM, ROM, and HDD, and store programs and data executed by the processing units 11 and 21. The interface units 13 and 23 are interposed between the processing units 11 and 21 and other devices, and relay data exchange between them. The buffer unit 24 is a storage device that sequentially accumulates blocks transmitted from the preprocessing unit 10. The buffer unit 24 may be configured using a part of the storage area of the storage unit 22.

  The input device 31 is a device that receives an instruction to the numerical control device A by an operator who uses the numerical control device A, and is, for example, a keyboard or a mouse. The display device 32 is a device that displays information to an operator, and is an LCD or the like. The input device 31 and the display device 32 are connected to the preprocessing unit 10, and the preprocessing unit 10 performs user interface processing for the worker by the input device 31 and the display device 32. The drive circuit 33 supplies power to an actuator such as a motor provided in the machine tool 2 based on a control command from the numerical control unit 20.

  Next, an example of a numerical control program will be described. The numerical control program is composed of a plurality of blocks, and these blocks are arranged in the order of execution. The numerical control program may include a plurality of continuous blocks that define the movement trajectory of the tool of the machine tool 2 in order to continuously process the workpiece. FIG. 2A is an explanatory diagram of the numerical control program, and shows an example of a plurality of continuous blocks (N) to (N + 4) that define the movement trajectory of the tool. These blocks show examples in which a tool (not shown) is moved from position P1 to position P6 while cutting or the like on a workpiece. Block (N) specifies that the tool is moved linearly from position P1 to position P2, and block (N + 1) specifies that the tool is moved linearly from position P2 to position P3. The same applies to blocks (N + 2) to (N + 4).

  Here, in this embodiment, the numerical control unit 20 sequentially stores the blocks transmitted from the preprocessing unit 10 in the buffer unit 24, and the numerical control unit 20 sequentially starts with the old blocks stored in the buffer unit 24. Processing such as generation of a control command to 2 is performed. In the case of such a configuration, for example, when blocks with a short tool movement amount continue, such as the blocks (N + 1) to (N + 4), the processing of each block by the numerical control unit 20 is finished early, and the buffer unit There is no block stock at 24, and a block-to-block stop can occur.

  Therefore, in the present embodiment, a plurality of consecutive blocks are converted into one new block so that the numerical control unit 20 needs a certain amount of time to process one block. By connecting the original blocks, stopping between blocks can be avoided more reliably without prolonging the processing time. The trajectory defined by the new block approximates the movement trajectory defined by the original blocks. FIG. 2B is an explanatory diagram of block conversion, and the example of FIG. 2A is the original block. In the example shown in the figure, the original blocks (N + 1) to (N + 4) are converted into one new block. In the case of this embodiment, the movement trajectory defined by the new block is set with the start point at the position P2 that is the start point of the original block (N + 1) and the end point at the position P6 that is the end point of the original block (N + 4). Thus, the starting point and the ending point of the original movement trajectory are linearly interpolated.

  The number of original blocks to be converted is determined in a range in which the total movement amount of the tools defined by them exceeds the prescribed movement amount. By using the total movement amount and the prescribed movement amount as a reference, the movement amount defined by the converted block is still very small, and it is possible to prevent the processing from being completed in a short time. The prescribed movement amount is set so as not to cause a stop between blocks. For example, the prescribed movement amount = movement speed × block from the movement speed of the tool and the transmission / reception time of the block from the preprocessing unit 10 to the numerical control unit 20. Transmission / reception time.

  For example, when the set moving speed is 500 kpulse / sec and the transmission / reception time of the block is 0.003 sec, the specified moving amount is calculated as 1500 pulses. The transmission / reception time of the block is unique to the apparatus and is input in advance. The moving speed of the tool is basically defined in the numerical control program, but there are cases where a change instruction is received from the operator during actual machining. For example, there is a case in which an instruction to change to X% speed increase or decrease is given to the numerical control device A via the input device 31. In such a case, the numerical controller A controls the machine tool 2 by changing the moving speed in accordance with the operator's instruction. In this case, the specified moving amount is also changed. For example, the processing unit 11 of the pre-processing unit 10 may change the specified movement amount when an instruction to change the moving speed is received from the operator. By doing so, it is possible to dynamically respond to a moving speed change instruction.

  FIG. 3 is a flowchart illustrating an example of processing executed by the processing unit 11. The preprocessing unit 10 converts a plurality of blocks into one new block as necessary and transmits the block to the numerical control unit 20. A processing example is shown. This process is executed when a plurality of blocks that define the movement trajectory of the tool are continuous as shown in FIG. In the numerical control program, each block may be sequentially transmitted from the CAD / CAM device 1 to the preprocessing unit 10 when the machining of the workpiece is performed, or all the numerical control programs from the CAD / CAM device 1 are previously stored. It may be transmitted to the processing unit 10, stored in the preprocessing unit 10, and read and processed when processing the processing target object.

  In FIG. 3, the setting is initialized in S1. Here, at least variables I and L are set to zero. A variable I indicates the number of times of connecting blocks, and a variable L indicates a total value of movement amounts calculated for each block. In S2, a block is read. The blocks are read one by one in the order on the numerical control program.

  In S3, for the sake of processing, the block read in S2 is set to a block in the order indicated by the variable I in order to identify the block. For example, when I = 0, it is the 0th block, and when I = 2, it is the second block. In S4, the movement amount of the tool movement locus defined by the block read in S2 is calculated. For example, in the case of the block (N) in FIG. 2A, the movement amount of the tool movement trajectory defined by this is the distance between the position P1 and the position P2. In S4, the movement amount calculated in S4 is added to the current variable L, and the variable L is updated to the value after the addition (L = L + 1).

  In S6, it is determined whether or not the variable I is 0. If the variable I is 0 (the stage in which the first block is processed), the process proceeds to S7, and if it is not 0, the process proceeds to S8. In S7, a new block after conversion is set temporarily. Here, the start point and end point of the movement locus are set as the start point and end point of the 0th block. That is, in S7, the contents of the original block are set as a new block. Even in S8, a new block after conversion is temporarily set. Here, the start point and end point of the movement locus are set as the start point of the 0th block and the end point of the Ith block. That is, in S8, the blocks are connected.

  In S9, it is determined whether or not the variable L is less than the specified movement amount. If applicable, the process proceeds to S10 to connect blocks, and if not, the process proceeds to S11. In S10, the variable I is incremented by 1, and the process returns to S2. In S11, a new block is transmitted to the numerical controller 20 with the contents set at that time. Thus, one unit of processing is completed.

  As described above, in this embodiment, the blocks are sequentially read in the process of S2 and the movement of the blocks read in S3 until it is determined in the process of S9 that the total movement amount of the blocks has reached the specified movement amount. The quantities are calculated sequentially. Each time the amount of movement is calculated in S4, the new converted block converted in S8 last time and the current block are connected and converted into a new block, and finally A series of a plurality of blocks is converted into a new block. A block in which the movement amount of the tool exceeds the specified movement amount without conversion is substantially transmitted as it is to the numerical control unit 20 via the processes of S7, S9, and S11.

<Second Embodiment>
In the first embodiment, the block is converted to a new block until the total movement amount of the block reaches the prescribed movement amount. However, since the movement locus is approximated, the movement defined by the original block is converted. An error occurs between the locus and the movement locus defined by the new block. FIG. 4A is an explanatory diagram of the error of the tool movement locus accompanying the block conversion. A solid line indicates a movement locus defined by the original block, and is composed of six straight lines connecting positions P11 to P17. A broken line indicates a movement locus defined by the new block after conversion, and is a single straight line connecting the position P11 and the position 17. An error of distance D occurs at the maximum. If the error increases, the required machining accuracy cannot be obtained.

  Therefore, in the present embodiment, if the error between the original movement trajectory and the converted movement trajectory approximating the original movement trajectory violates a predetermined error standard, the conversion is aborted. FIG. 4B is an explanatory diagram of block conversion in consideration of an error in the movement locus, and assumes the same original movement locus as that in FIG. In the example of FIG. 4B, there are two new blocks after conversion. One defines a straight line connecting the position P11 and the position P14, and the other defines a straight line connecting the position P14 and the position P17. It prescribes. By doing so, errors can be reduced. The error standard can be set as appropriate according to the machining accuracy required for the workpiece.

  FIG. 5 is a flowchart showing an example of processing executed by the processing unit 11, and shows an example of processing instead of FIG. In FIG. 5, the same processes as those in FIG. In the present embodiment, after the process of S8, an error (maximum value) between the movement path defined by the original block in S21 and the movement path defined by the new block set in S8 is calculated. In S22, it is determined whether or not the error calculated in S21 is less than the error standard. If yes, go to S9, otherwise go to S23. In S23, since the error standard is violated, the contents set in S8 this time are invalidated, and a new block having the contents set in S8 last time is transmitted to the numerical controller 20.

  For example, if the variable I = 3 is currently being processed for the third time, a new block having the content set in the second S8 is transmitted to the numerical controller 20. By doing so, it is possible to prevent the conversion that violates the error standard from being performed, and it is possible to realize processing that prioritizes the error standard. In addition, about the new block transmitted to the numerical control part 20 by S23, although the total amount of the movement amount of the original block has not reached the regulation movement amount, such a new block is a buffer part. As long as it is dotted with 24, it is considered that the possibility of the stoppage between blocks is low.

<Third Embodiment>
In the first embodiment, the block conversion is performed by the preprocessing unit 10. However, the preprocessing unit 10 specifies the original block to be converted, and the numerical control unit 20 performs conversion of a new block. You may do it. When the load on the preprocessing unit 10 is high, the load on the preprocessing unit 10 can be reduced. FIG. 6 is a flowchart illustrating an example of processing executed by the processing unit 11 in the present embodiment. The processing from S31 to S35 is the same as the processing from S1 to S5 in FIG.

  In S36, it is determined whether or not the variable L is less than the specified movement amount. If applicable, the process proceeds to S37, and if not, the process proceeds to S38. In S37, the variable I is incremented by 1, and the process returns to S32. In S38, it is determined whether or not the variable I is zero. If the variable I is 0 (the stage in which the first block is processed), the process proceeds to S39, and if it is not 0, the process proceeds to S40. In S39, the 0th block is transmitted to the numerical control unit 20. That is, the block first read in S32 is transmitted to the numerical control unit 20 as it is.

  In S <b> 40, the 0th to Ith blocks are transmitted to the numerical control unit 20 at once. That is, these block groups are block groups in which the movement amount of the tool defined by each block is insufficient for the predetermined movement amount. When transmitting a plurality of blocks at the same time in S40, an identifier is added for distinguishing from normal individual block transmission. For example, an identifier indicating that the block is for batch transmission is inserted at the end of each block.

  FIG. 7 is a flowchart illustrating a processing example of the processing unit 21 of the numerical control unit 20 according to the present embodiment. When a block group transmitted in batch from the preprocessing unit 10 is received, the block is converted into one new block. Indicates processing. In S51, settings are initialized. Here, at least the variable I is set to 0. The meaning of the variable I is the same as that in the first embodiment, and indicates the number of times of connecting blocks. In S52, one received block is read. In S53, a new block after conversion is temporarily set. Here, the start point and end point of the movement locus are set as the start point of the 0th block and the end point of the Ith block. That is, the process is the same as S8. In S54, it is determined whether or not all of the block groups collectively transmitted from the pre-processing unit 10 have been processed. If all of the blocks have been processed, one unit of processing is terminated. If not, the processing returns to S52 and similar processing is performed. repeat.

  By doing so, the conversion target can be selected by the pre-processing unit 10 and the conversion can be performed by the numerical control unit 20, and the processing load of the pre-processing unit 10 can be reduced when the processing capacity of the numerical control unit 20 is high. Note that this embodiment can also be combined with the second embodiment, and in this case, processing related to errors (S21, S22, S23 (points where the previous setting is adopted)) is performed by the numerical controller 20. Can be done.

<Fourth embodiment>
The process of the third embodiment shown in FIGS. 6 and 7 (hereinafter referred to as a first pattern process) and the process of the first embodiment shown in FIG. 3 (hereinafter referred to as a second pattern process). ) Can be selected and switched according to the load status of the preprocessing unit 10 and the load status of the numerical control unit 20. FIG. 8 is a block diagram of a system using a numerical controller B according to another embodiment of the present invention. In FIG. 8, the same components as those of the numerical controller A shown in FIG.

  The numerical controller B includes a load monitoring / pattern selection unit 40. The load monitoring / pattern selection unit 40 is interposed between a processing unit 41 such as a CPU, a storage unit 42 that is a storage device such as a RAM, a ROM, and an HDD, and between the other devices and the processing unit 41. An interface unit 43 that relays data transfer is provided.

  FIG. 9 is a flowchart illustrating a processing example executed by the processing unit 41. The processing unit 41 periodically executes the process shown in FIG. In S61, information indicating the load status of the preprocessing unit 10 and the numerical control unit 20 is acquired. Examples of the information indicating the load status include a CPU usage rate output by the CPU, and can be acquired from the processing units 11 and 21, respectively.

  In S62, based on the information acquired in S61, it is determined whether or not the load of the processing unit 11 of the preprocessing unit 10 exceeds the load of the processing unit 21 of the numerical control unit 20. If applicable, the process proceeds to S63, and if not, the process proceeds to S64. In S63, the first pattern processing is selected, and the processing unit 11 of the preprocessing unit 10 is instructed to execute the first pattern processing. In S63, the process of the second pattern is selected, and the execution of the process of the second pattern is instructed to the processing unit 11 of the preprocessing unit 10. Thus, one unit of processing is completed.

  By doing in this way, when the load of the pre-processing part 10 is high, it becomes the process of the said 3rd Embodiment, and when it is low, it becomes the process of the said 1st Embodiment, Therefore The pre-processing part 10 and the numerical control part 20 The situation where the load is concentrated on one side can be solved.

  The pattern selection result is instructed only to the preprocessing unit 10, but may be instructed to the numerical control unit 20. However, the numerical control unit 20 only needs to recognize whether or not the block transmission is a batch transmission and convert the block. Therefore, if the function of executing the processing of the third embodiment is provided, the pattern selection result There is no need to recognize.

  In the present embodiment, in S62, the load of the processing unit 11 of the preprocessing unit 10 and the load of the processing unit 21 of the numerical control unit 20 are directly compared, but the processing capability of the processing unit 11 and the processing unit are included. If there is a large difference in the processing capability of the processing unit 21, the pattern is determined by whether or not the difference between the load of the processing unit 11 of the preprocessing unit 10 and the load of the processing unit 21 of the numerical control unit 20 is less than a specified value. You may make it select.

Claims (8)

A processing device for processing a numerical control program including a plurality of continuous blocks that defines a movement trajectory of a tool,
A calculation means for calculating a movement amount of the tool when each of the blocks is executed;
A plurality of blocks including the block when the movement amount calculated by the calculation means is less than a prescribed movement amount, and a total amount of the movement amounts is equal to or greater than the prescribed movement amount; Converting means for converting the block into a new block that defines a movement trajectory approximating the movement trajectory of the tool defined by these blocks;
A processing apparatus comprising:   It is determined whether or not an error between a movement trajectory of the tool defined by the plurality of blocks to be converted by the conversion means and a movement trajectory approximating the movement trajectory violates a predetermined error standard. The processing apparatus according to claim 1, further comprising an error determination unit. The calculation means sequentially calculates the movement amount for each of the blocks,
Each time the calculation means calculates the movement amount, the conversion means calculates the movement amount by the new one converted block and the calculation means until the total amount becomes equal to or greater than the specified movement amount. Converted to the new one block,
The error determination means performs the error determination each time the conversion means converts a new block,
The processing apparatus according to claim 2, wherein the conversion of the conversion unit at the stage where the error determination unit determines that the violation is invalid is invalidated.   The processing apparatus according to claim 1, further comprising a changing unit that changes the prescribed movement amount in response to an instruction to change a moving speed of the tool. A pre-processing unit and a numerical control unit that outputs a control command to the machine tool,
The pre-processing unit is
The computing means;
Transmission means for transmitting the block to the numerical control unit,
The numerical control unit
Receiving means for receiving the block from the pre-processing unit;
The conversion means,
The transmission means includes
A plurality of blocks including the block when the movement amount calculated by the calculation means is less than a prescribed movement amount, and a total amount of the movement amounts is equal to or greater than the prescribed movement amount; The block of is sent to the numerical control unit at once,
The converting means includes
When the receiving unit receives the plurality of blocks collectively transmitted from the transmitting unit, a new block defining a movement locus approximating the movement locus of the tool defined by the received plurality of blocks is obtained. The processing apparatus according to claim 1, wherein the processing apparatus performs conversion. A preprocessing unit including a transmission unit that transmits the block to the arithmetic unit and the numerical control unit;
A numerical control unit comprising receiving means for receiving the block from the preprocessing unit, and outputting a control command to a machine tool;
Selecting means for selecting the first processing pattern or the second processing pattern based on the load status of the pre-processing unit and the load status of the numerical control unit;
The conversion means includes a first conversion means provided in the preprocessing unit, and a second conversion means provided in the numerical control unit,
When the selection means selects the first processing pattern,
The first conversion means does not perform the conversion,
The transmission means includes
A plurality of blocks including the block when the movement amount calculated by the calculation means is less than a prescribed movement amount, and a total amount of the movement amounts is equal to or greater than the prescribed movement amount; The block of is sent to the numerical control unit at once,
The second conversion means includes
When the receiving unit receives the plurality of blocks collectively transmitted from the transmitting unit, a new block defining a movement locus approximating the movement locus of the tool defined by the received plurality of blocks is obtained. Converted,
When the selection means selects the second processing pattern,
The first conversion means performs the conversion,
The processing apparatus according to claim 1, wherein the second conversion unit does not perform the conversion. A processing method for processing a numerical control program including a plurality of continuous blocks that defines a movement trajectory of a tool,
A calculation step of calculating the amount of movement of the tool when each of the blocks is executed;
When the movement amount calculated in the calculation step is less than a prescribed movement amount, a plurality of the blocks including the block are continuous, and the total amount of the movement amounts is not less than the prescribed movement amount Converting the block into a new block that defines a movement locus that approximates the movement locus of the tools defined by these blocks;
A processing method characterized by comprising: In order to process a numerical control program including a plurality of consecutive blocks that define the movement trajectory of the tool,
Calculation means for calculating the amount of movement of the tool when each of the blocks is executed,
A plurality of blocks including the block when the movement amount calculated by the calculation means is less than a prescribed movement amount, and a total amount of the movement amounts is equal to or greater than the prescribed movement amount; Converting means for converting the block into a new block that defines a movement trajectory approximating the movement trajectory of the tool defined by these blocks;
Program to function as.

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