JP3692990B2 - Numerical controller - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a numerical controller that sequentially analyzes and executes an NC program composed of a plurality of blocks for each block.
[Prior art]
In a numerical control apparatus that sequentially analyzes and executes an NC program composed of a plurality of blocks for each block, in a system that controls a plurality of axes, the axes must be moved in synchronization between the plurality of axes. There is a case. Even if only one axis is controlled, it may be necessary to wait for the signal input from the outside to turn on or off and to start the axis movement. In such a case, as illustrated below, the execution of the NC program is continued in an infinite loop until the execution condition (SB277 = 1 in this example) is satisfied, and the execution condition is satisfied. If the condition is satisfied, the processing can be moved to the next and subsequent blocks.
[WHILE (SB277 = 1) DO] (* Waiting for fixed-size rising edge ON *)
[ENDWHILE;]
[0002]
However, when such an NC program is executed, the following problems occur. That is, since the WHILE command block and the ENDWHILE command are separate blocks, the data of each block must be read, analyzed, and executed each time. This increases the load on the NC program processing of the microprocessor of the numerical controller. When NC program processing occupies most of the processing capacity of the microprocessor, communication processing with a programmable controller or monitor device that is performed in parallel with NC program processing, display processing for displaying the state of numerical control status, etc. The time for executing the peripheral processing is limited. As a result, the display content of the monitor device that monitors and displays the operation status of the numerical control device or the display content by the LED of the numerical control device is lost in real time, or the time required for data exchange with other control devices is normal. Failures such as taking longer than that occur.
[0003]
In order to explain this phenomenon, a time chart when the NC program is executed is shown in FIG. In FIG. 8, (1) represents the processing of the WHILE command block, and (2) represents the processing of the ENDWHILE command block. The analysis and execution processing of the NC program is activated by a trigger generated at a constant period, and executes one block of processing. The cycle in which the trigger is generated is a time with a certain margin in the time required for the analysis processing and execution processing of one block such as the WHILE command block and the ENDWHILE command block. If the trigger generation cycle is longer than necessary, the execution of the NC program is delayed. If the trigger generation cycle is short, one block of processing cannot be completed within one cycle. The trigger generation period is set to an appropriate value according to the hardware processing capability of the apparatus. In general, a timer interrupt signal generated at regular intervals is used as a trigger.
[0004]
Peripheral processing is executed when these NC programs are not being processed. As shown in FIG. 8, since time is required for the analysis and execution processing of the NC program, the time for performing the peripheral processing is reduced during the processing of the WHILE command block and the ENDWHILE command block. For this reason, the display content of the monitor device that monitors and displays the operation status of the numerical control device is lost in real time, and troubles such as longer time than usual for data exchange with other control devices occur. It is.
[0005]
In order to prevent the occurrence of this failure, conventionally, a dwell command (a command that idles execution of the NC program for a specified time) is inserted after the WHILE command, and peripheral processing is executed during this dwell time. It was. This dwell time is typically a few hundred ms. The NC program after adding a dwell command is as follows.
[WHILE (SB277 = 1) DO] (* Waiting for fixed-size rising edge ON *)
G04P0.2 (* 200ms duel *)
[ENDWHILE;]
[0006]
A time chart for executing this NC program is shown in FIG. In FIG. 9, (1) represents the processing of the WHILE command block, (2) represents the processing of the ENDWHILE command block, and (circle) represents the processing of the dwell command block. In the dwell command block processing, analysis (decoding) processing is first performed once, and thereafter, it is only confirmed whether or not the dwell time has elapsed when an interrupt signal is generated. If the specified time elapses, the next block (ENDWHILE command block) is processed. As a result, analysis processing is not performed each time an interrupt signal is generated, so that time for performing peripheral processing can be secured.
[0007]
[Problems to be solved by the invention]
Therefore, according to such an NC program, peripheral processing can be executed during the dwell time, and the failure described above does not occur, but on the other hand, the execution condition is satisfied during the time specified by the dwell command. Since it is not determined whether the execution condition is satisfied, there is a problem that the timing for detecting the execution condition is delayed.
[0008]
For example, as shown in Japanese Patent Application No. 2001-210323, in the case of two grinders that operate independently in the X-axis direction and the Z-axis direction, respectively, in order to prevent the grinders from interfering with each other, In order to coordinately perform the movement in the X-axis direction and the movement in the Z-axis direction on the table, the axes must be operated by synchronizing the axes many times during one cycle. Further, it is necessary to perform processing such as interlocking the workpiece general input / output signal and the like to start the axis movement. In these cases, even if the execution condition is satisfied, since the execution condition cannot be detected for the time specified by the dwell command at the maximum, the cycle time of the entire machining cycle is extended by several seconds. appear.
[0009]
In addition to this problem, if the execution condition is not satisfied for a long time due to some trouble, the NC program processing does not proceed first, and the operator is not notified of the abnormality until the alarm is output due to the cycle time over. There was a problem that it took a long time to start the recovery work after the occurrence.
[0010]
As a countermeasure to this problem, if an I / O signal for each execution condition is output to the programmable controller and the wait time for each execution condition is monitored by the programmable controller, an alarm is immediately output when the time limit is exceeded. To be able to. However, in order to implement this measure, a sequence program must be set up for each execution condition to be monitored, so that the burden on the designer is great, and the scan time of the sequence program also increases. Furthermore, since most of the I / O signals are occupied, there is a new problem that the number of I / O signals between the numerical controller and the programmable controller is insufficient.
[0011]
In view of these problems, the present invention detects the establishment of an execution condition early and specifies the waiting time until the execution condition is established without outputting an I / O signal for each execution condition to the programmable controller. It is an object of the present invention to provide a numerical control device capable of performing necessary abnormality processing such as notifying an operator of an abnormality immediately when the time-out time exceeded.
[0012]
[Means for Solving the Problems]
According to the first aspect of the present invention, in relation to a condition waiting block that is one block in an NC program consisting of a series of blocks, an execution condition for enabling processing execution of blocks after the condition waiting block and the block The execution condition satisfaction waiting time-out time is stored. When processing a condition waiting block, the processing contents of the condition waiting block are analyzed from the execution condition and the timeout time, and the analysis result is stored. When executing the execution process of the condition waiting block due to occurrence of a predetermined trigger, the execution process is performed based on the stored analysis result without performing the analysis process every time. This ensures a processing time for performing the peripheral processing.
This execution process is performed according to the following procedures (a) to (d).
(A) It is determined whether or not the execution condition is satisfied.
(B) When the result of the determination is affirmative, processing of blocks after the condition waiting block can be executed.
(C) If the result of the determination is negative, peripheral processing is performed until the next trigger occurrence.
(D) If the waiting time for establishing the execution condition exceeds the timeout time, a timeout error is determined.
[0013]
As a result, while the processing time for performing the peripheral processing is secured, when the execution condition is not satisfied, the determination whether the execution condition is satisfied is performed every time the trigger is generated, and the waiting time for the satisfaction of the condition is timed out. If the time is exceeded, it is immediately judged as abnormal.
[0014]
According to the second aspect of the present invention, when the time for waiting for the execution condition to be satisfied exceeds the time-out time, information indicating that the time-out time has been exceeded is stored in an area that can be referred to in the block following the condition-waiting block, and NC Program processing proceeds to the block following the condition wait block. In a block following the condition waiting block, necessary abnormality processing is performed based on information indicating that the stored timeout time has been exceeded. Thereby, the recovery operation by the operator can be performed quickly.
[0015]
In the invention according to claim 3, the execution condition and the timeout time are described in the condition waiting block. Thereby, the relationship between the contents of the block executed when the execution condition is satisfied, the execution condition, and the timeout time can be clearly grasped on the NC program.
[0016]
In the invention according to claim 4, at least one of the execution condition and the timeout time is stored as a parameter. Thereby, the execution condition and the timeout time can be easily set and changed.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of an equipment control system including a numerical control device 1 according to the present invention and devices connected thereto.
[0018]
The numerical control device 1 sends a command to the servo amplifier 4 to control the equipment 5 according to the NC program created by the user while communicating with the monitor device 2 and the programmable controller 3. The monitor device 2 reads the state of the numerical control device 1 by communication and displays it on the display. The programmable controller 3 is a controller that supervises the entire equipment control while exchanging data with the numerical controller 1 and the limit switch 51 and proximity switch 52 that are assembled in the equipment 5 to be controlled. The servo amplifier 4 drives a servo motor 53 assembled in the equipment 5 based on a command from the numerical controller 1. There may be only one servo amplifier connected to one numerical control apparatus 1, or there may be a plurality of servo amplifiers.
[0019]
FIG. 2 is a block diagram showing functions of the numerical control apparatus 1 of the present invention. In this figure, the software process is represented by one block.
[0020]
A numerical control apparatus 1 according to the present invention includes a program memory 10, an analysis processing unit 11 connected to the program memory 10, an interrupt signal generation unit 12 that outputs an interrupt signal generated at a constant period to the analysis processing unit 11, an analysis processing unit 11, and the like. The execution processing unit 13 is connected, the drive processing unit 14 and the data memory 15 are connected to the execution processing unit 13, and the communication processing unit 16 is connected to the data memory 15.
[0021]
When the numerical controller 1 is in operation, the NC program stored in the program memory 10 is read to the analysis processing unit 11 for each block. The analysis processing unit 11 analyzes the read block data, and the execution processing unit 13 performs execution processing based on the analysis result. If the block is a block with an axis movement instruction, a drive instruction with designation of positioning coordinates, speed, movement time, etc. is given to the drive processing unit 14. The drive processing unit 14 sends a command to the servo amplifier 4 in accordance with this drive instruction to control the operation of the servo motor 53. Communication with the monitor device 2 and the programmable controller 3 is performed by the communication processing unit 16. This communication process is executed when none of the analysis process in the analysis processing unit 11, the execution process in the execution processing unit 13, or the drive process in the drive processing unit 14 is executed. Data such as variables used in processing performed by the analysis processing unit 11, the execution processing unit 13, the drive processing unit 14, and the communication processing unit 16 is stored in the data memory 15.
[0022]
In the NC program, a condition waiting block is described before a block for starting axis movement in synchronization with another axis or a block for performing some processing after waiting for a change in an input signal from the outside. In the condition waiting block, an execution condition that is a condition for causing the NC program to proceed to a block subsequent to the condition waiting block and a timeout time that is a limit value of the time for waiting for the execution condition to be satisfied are described. The format of the condition waiting block is as follows.
G31G04P_K_
[0023]
Here, “G04” indicates that this block is a condition waiting block. “K” is an identifier indicating that an execution condition is specified, and specifies a bit address of data following “K”. “P” is an identifier indicating that a timeout time is specified, and “P” is followed by a time in seconds. “G31” indicates that the execution condition is considered to be satisfied when the data of the bit address designated by “K” is “1”. When “G32” is designated instead of “G31”, it is considered that the execution condition is satisfied when the data of the bit address is 0.
[0024]
For example, when the signal “SB227” is 0, the NC program after the command block is executed, and when the “SB227” signal is not 0, the “SB227” signal is monitored for up to 1 second. The command is
G31G04P1K [SB227]
It becomes.
[0025]
If the execution condition is not satisfied even after the timeout time (1 second in the above example) specified by “P” has elapsed since the start of monitoring whether or not the execution condition is satisfied, it is determined that there is an abnormality.
[0026]
The processing by the analysis processing unit 11 of each block of the NC program is started by using the interrupt signal output at a constant cycle by the interrupt signal generation unit 12 and is executed by the execution processing unit 13 based on the analysis result. . In the case of a block that takes a long time to process, the processing at the time of the second and subsequent interrupt signal generation is executed based on the analysis result at the time of the first interrupt signal generation. Which block in the NC program is to be processed is managed by a register called a program counter according to a sequence number attached to the head of each block.
[0027]
The outline of the processing procedure of one block of the NC program will be described with reference to the flowchart shown in FIG. When the interrupt signal is generated by the interrupt signal generation unit 12, it is determined by the processing of the analysis processing unit 11 whether the block having the sequence number designated by the program counter is to perform the first processing (step 10). If the result of the determination in step 10 is Yes, the command data of the block is read from the program memory 10 (step 11), and the process to be executed by the execution processing unit 13 from the execution condition and timeout time included in the command data The contents are stored (step 12). Next, the analyzed result is stored (step 13). The execution processing unit 13 performs an execution process based on the analysis result stored in Step 13 (Step 14). If the result of the determination in step 10 is No, the processing of the block in which the analysis result has already been stored at the time of the start of the analysis processing by the previous interrupt signal is continued, so the processing of steps 11 to 13 is performed again. Instead, the execution processing unit 13 performs processing based on the analysis result stored in step 13 (step 14).
[0028]
Next, FIG. 4 shows a processing procedure in the case where the execution processing unit 13 processes the condition waiting block in step 14. An execution condition is extracted from the analysis result of the command data, and it is determined whether or not the execution condition is satisfied (step 20). If the determination result is affirmative, the sequence number of the block next to the condition waiting block is written to the program counter (step 21), and the processing of step 14 is terminated. On the other hand, if the determination result in step 20 is negative, it is determined whether the currently executed process is the first process (step 22). If it is the first process, time measurement is started (step 23), and the process of step 14 is ended. If it is the second and subsequent processing, the elapsed time from the time measurement is started in step 23 is compared with the timeout time extracted from the analysis result of the command data (step 24). As a result of the comparison, if the elapsed time does not exceed the timeout time, the processing of step 14 is terminated as it is, and if it exceeds, error information indicating that a timeout error has occurred is stored in the data memory 13 (step 25). This error information can be referred to by an NC program command. Thereafter, the sequence number of the block next to the condition waiting block is written to the program counter (step 26), and the processing of step 14 is terminated. After the processing in step 14, the peripheral processing is executed until the next interrupt signal is generated.
[0029]
When the value of the program counter is rewritten in step 21 or step 26, the next block of the condition waiting block is processed when the next interrupt signal is generated. If the value of the program counter is not rewritten, the block of the condition waiting block is processed again when the next interrupt signal is generated.
[0030]
The equipment control process in the blocks after the condition waiting block is illustrated in the flowchart of FIG. In step 30, the error information stored in the data memory 13 is referred to, and it is determined in step 20 whether the processing of the condition waiting block has been completed because the execution condition has been established, or whether the processing has been terminated due to the occurrence of a timeout error in step 24. To branch processing. If the execution condition is satisfied, the facility control is continued (step 31). If a time-out error has occurred, an abnormality process such as returning the axis to the original position is performed (step 32), and an alarm is output to notify the operator of the occurrence of the abnormality (step 33).
[0031]
As described above, when the condition waiting block is executed by the procedure described above, if the execution condition specified by the command block is satisfied, the execution process is immediately shifted to the next block. If the execution condition is not satisfied, it is repeatedly checked whether the execution condition is satisfied until the timeout time elapses, and if the timeout time elapses, it is determined that there is an abnormality.
[0032]
As a result, the execution condition is checked each time an interrupt signal is generated, so that the execution condition can be detected at an early stage, and the waiting time until the execution condition is satisfied exceeds the timeout time. Can immediately perform necessary abnormality processing such as notifying the operator of the abnormality.
[0033]
In addition, since the analysis process of the condition waiting block is performed only at the time of starting the first analysis / execution process by the interrupt signal, the analysis / execution process of the command block is started repeatedly when the execution condition is not satisfied. Only execution processing is performed. For this reason, the time for performing peripheral processing such as communication processing with the monitor device 2 and the programmable controller 3 in the communication processing unit 14 is secured, and troubles such as slow update of display contents and slow communication speed occur. There is nothing.
[0034]
FIG. 6 shows a time chart in the processing of the condition waiting block of the present invention. In this figure, ● represents processing related to a condition waiting block, and * represents processing related to a block next to the condition waiting block. As is clear from this figure, since the analysis process is not performed every time, the time required for the program analysis / execution process when an interrupt signal is generated is short, and the time for performing the peripheral process is sufficiently secured.
[0035]
If a time-out error is detected in step 24, the NC program may be stopped without proceeding to subsequent blocks after notifying the abnormality. Or you may make it distinguish whether execution of an NC program is stopped or continued by the description content of a condition waiting block.
[0036]
Also, the execution condition and the timeout time may be specified not by NC program commands but by parameter settings. In the case of parameter setting, as illustrated in FIG. 7, the execution condition and timeout time are set together with an identification code for identifying which of a plurality of condition waiting blocks exist in the NC program. In this case, the format of the command block described in the NC program is as shown below.
G31G04I_
Here, “I” is an identifier for designating an identification code to be referred to in the matrix in FIG. For example, when the identification code is 20, it is “G31G04I20”. In this case, unlike the NC program command described above, it is not necessary to specify an execution condition and a timeout time for each block. That is, the setting can be made collectively as in the matrix of FIG.
[0037]
In this embodiment, an interrupt signal generated at a constant period is used as a trigger for starting analysis / execution processing. However, a trigger for starting analysis / execution processing may be generated by software processing.
[0038]
【The invention's effect】
As described above, in the present invention, the determination of whether or not the execution condition is satisfied, the process of repeatedly performing the re-determination when the execution condition is not satisfied, and the detection of the execution condition establishment wait timeout error are performed once. It was decided to do this during the waiting block execution process. As a result, first, the result of analyzing the processing contents of the condition waiting block is stored, and based on this, execution processing can be performed every time a predetermined trigger occurs, so it is determined whether or not the execution condition is satisfied at high frequency. While performing, peripheral processing time can be secured rather than NC program processing. Further, when the waiting time until the execution condition is satisfied exceeds the timeout time, necessary abnormality processing such as immediately informing the operator of the abnormality can be performed. Here, it is not necessary to send an I / O signal to the programmable controller in order to monitor the time when the execution condition is satisfied, and to detect a timeout error by sequence program processing in the programmable controller. Therefore, problems such as an increase in the scan time of the sequence program and occupation of a large number of I / O points do not occur.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of an equipment control system according to an embodiment of the present invention.
FIG. 2 is a block diagram showing functions of the numerical control device according to the embodiment of the present invention.
FIG. 3 is a flowchart showing an outline of a processing procedure of one block of the NC program.
FIG. 4 is a flowchart illustrating a processing procedure of a condition waiting block.
FIG. 5 is a flowchart showing a processing procedure after a condition waiting block.
FIG. 6 is a time chart in processing of a condition waiting block according to the present invention.
FIG. 7 is a diagram illustrating a setting example when parameters are set for an execution condition and a timeout time.
FIG. 8 is a time chart of a condition waiting process in the prior art.
FIG. 9 is a time chart of a condition waiting process in the prior art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Numerical control apparatus 2 Monitoring apparatus 3 Programmable controller 4 Servo amplifier 5 Control object equipment 10 Program memory 11 Analysis process part 12 Interrupt signal generation part 13 Execution process part 14 Drive process part 15 Data memory 16 Communication process part

Claims (4)

An NC program composed of a series of blocks is sequentially read and analyzed in units of blocks, and the execution processing of the block is performed due to the occurrence of a predetermined trigger based on the result of the analysis processing, and the analysis processing and the execution processing In the numerical control device that performs peripheral processing in parallel with
Program storage means for storing a condition waiting block that is a single block existing between the series of blocks and controls the processing execution timing of the subsequent blocks;
Condition storage means for storing an execution condition for enabling processing execution of blocks subsequent to the condition waiting block and a timeout period of establishment waiting time of the execution condition in association with the condition waiting block;
Analyzing the processing content of the condition waiting block from the execution condition and the timeout time, and storing an analysis result;
Execution processing based on the stored analysis results every time the trigger occurs, and execution processing means for ensuring processing time for performing the peripheral processing,
The execution processing means includes
Determining means for determining whether or not the execution condition is satisfied;
Means for enabling processing execution of blocks after the condition waiting block when the result of determination by the determination means is affirmative;
Means for performing the peripheral processing until the next trigger occurrence when the result of the determination by the determination means is a negative determination;
Means for determining a timeout error when a waiting time for establishing the execution condition exceeds the timeout time;
A numerical control device comprising: Means for storing information indicating that a timeout error has occurred when the execution processing means determines that a timeout error has occurred, and enabling processing execution of blocks after the condition waiting block;
In the block after the condition waiting block, referring to information indicating that the timeout error has occurred, abnormal processing means for performing an abnormal processing based on this,
The numerical control apparatus according to claim 1, comprising: The numerical control apparatus according to claim 1, wherein the execution condition and the timeout time are described and stored as commands of an NC program. The numerical control apparatus according to claim 1, wherein at least one of the execution condition and the timeout time is stored as a parameter.

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