JPH09288509A - Numerical control device block data processing method - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To use the same program for roughing, semi-finishing, and finishing, and to speed up program analysis processing in semi-finishing even without incorporating a high-performance processor. Block data of a numerical control device such as a machine tool or robot that has two or more drive axes and moves while linearly interpolating a program consisting of a plurality of given moving blocks with line segments per distribution cycle In the processing method,
The maximum amount of tolerance between the moving amount of the block after the starting point and the vector of the combined moving amount and the trajectory of the block before combining or the block before combining with the vector of the combined moving amount A block data processing method for a numerical control device, wherein the combined block is redefined as one block if the angle formed with the vector of is less than or equal to a preset value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of processing program block data of a numerical control device for machine tools and robots having two or more drive axes.

[0002]

2. Description of the Related Art In die processing, a curved surface is processed using a program composed of minute linear blocks. Conventionally,
Figure 1 shows a numerical control system for controlling machine tools and robots.
As shown in 0, the program is read, the program is analyzed, interpolation of straight lines and circular arcs is performed, and the movement amount of the program block is distributed as a movement pulse to each axis in every distribution cycle, and then the servo is performed on each feed axis. You are in control. Here, in order to reduce the error between the actual curved surface and the shape of the machining program, it is necessary to shorten the block length.

When precision is required, the moving block has a very small length, as seen in the finishing process of die machining of a machine tool, but when the moving block becomes short, the moving block is processed per unit time. Since the number of blocks was large, the load on the program analysis processing unit was large. For this reason, in the case of a machining program with a short movement amount per block, the program analysis process may not be in time depending on the feed rate, and the feed rate may be reduced to reduce the number of blocks processed per unit time, or It was necessary to apply a high-performance processor to the block analysis processing section to speed up program analysis processing.

[0004]

However, in the prior art, the machining accuracy may be lower than that of finishing, as in the case of intermediate finishing just before finishing in die working.
Instead, if you want to shorten the machining time, if you use a program for finishing machining, it is not possible to increase the feed rate because the program block division is fine and the program block division is rough. Was needed. For this reason, there is a problem that two programs, that is, a rough division program of the movement command block for the intermediate finishing and a fine division program of the movement instruction block for the finishing machining are required.

Further, when processing a three-dimensional free curved surface,
Rough machining, semi-finishing, and finishing machining were required. Creating three types of machining programs with the same shape requires a heavy load and time on the program creation device. It is possible to perform roughing and semi-finishing with a finishing machining program, but since the finishing machining program attaches great importance to machining accuracy, one block is composed of a minute movement distance. For this reason, the processing time becomes long when the block processing capability of the numerical control device cannot keep up. Generally, in roughing and semi-finishing, the processing time is more important than the processing accuracy, so it cannot be said to be optimum. Therefore, the present invention uses the same program for rough machining (if applicable), semi-finishing, and finishing, and speeds up the program analysis processing for semi-finishing even without incorporating a high-performance processor. With the goal.

[0006]

In order to solve the above problems, the present invention provides a tolerance between a vector obtained by combining movement amounts of program blocks over several blocks and a trajectory before combining, or the combined movement thereof. If the angle formed by the vector of the quantity and the vector of the block before combining is within the set allowable range, the moving amounts of those blocks are combined and a new moving block is replaced. is there. Further, this block synthesizing process is simultaneously performed during the program operation of the numerical control device, or the program operation is performed by a program which has been subjected to the block synthesizing process in advance. Furthermore, when performing this block composition processing during program operation, the program trajectory shape,
If the set tolerance tolerance is large, the process of synthesizing blocks may continue for a long time, which may interrupt the program analysis. Therefore, an upper limit is set for the number of blocks to be synthesized.

According to the present invention, according to the present invention, even if the finishing machining program is used in the intermediate finishing machining, the program blocks are combined into one movement command block within the allowable tolerance range, and then the ordinary program is executed. Since the block analysis processing is performed, the program block analysis processing unit reduces the number of blocks to be analyzed per unit time, so that the machining command speed can be increased.
In addition, the program block composition processing can be executed before the program operation of the numerical controller, as well as during the program operation of the numerical control device. Therefore, use only a commercially available personal computer to perform the block composition processing. It is also possible to perform the program operation by the block-synthesized program in the numerical controller which does not have the block synthesizing process. Further, since the upper limit value of the blocks to be combined is set, it is possible to prevent the block combining process from continuing indefinitely.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a finishing machining program created by a program creating device is machined while being converted into rough machining and intermediate finishing machining in a numerical controller. In roughing and semi-finishing, the allowable accuracy is looser than that in finishing, because shortening the processing time is more important than accuracy. 3
The dimensional free-form surface and the tolerance being loose means that the movement distance of one block of the machining program is long,
Since the feed rate can be increased in the block processing capacity of the numerical control device, the processing time can be shortened. According to the present invention, the data of the allowable accuracy is input to the numerical control device before processing, so that the blocks of the processing program are combined within the allowable accuracy range and the block analysis processing is performed.

This block synthesizing procedure will be described with reference to FIGS. FIG. 7 shows a part of the finishing machining program, which is composed of continuous linear blocks starting from the N1 block. FIG. 6A shows a part of the program locus corresponding to the machining program of FIG. 7, and the starting point and the ending point of each block are represented by AF. FIG. 8 is a block synthesis flow, and the flow of block synthesis processing will be described below. The current position is set to point A in FIG. The block N1 to be moved next from the point A is read, the next block N2 is further read, a composite vector AC from the point A to the end point C of the block N2 is created, and the distance between the point B and the vector AC between ACs is created. Seeking some tolerance. If the tolerance is equal to or less than the allowable value, the next block N3 is further read, a vector AD is created, and the tolerances of the points B and C between AD are obtained. Here too, if the tolerance is the allowable value, the next block is further read, and the tolerance is compared with the allowable value while performing the same processing as the previous block. If the obtained tolerance exceeds the allowable value, the blocks from the point A to the end point of the block before this time reading are combined to make one block. For example, as shown in FIG. 6B, the vector AD
When the tolerance Tr between the point C and the point C exceeds the allowable value, the vector AC is defined as one block. After that, the end point of the block synthesized this time (point C in FIG. 6B) is set as point A, blocks after point A are set as N1, N2, N3, ... And the above block synthesizing process is repeated. By performing the above block synthesizing process, the moving distance of one block becomes long, and processing can be performed within the block processing capacity of the numerical control device. Whether to perform block composition or not is determined based on the distance tolerance, and whether the angle between the vector of the combined movement amount and the vector of the block before composition is less than the allowable value. You can also

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The flow of the present invention is shown in FIG. FIG. 1 shows a flow of a program operation process of a numerical controller using the present invention. 2 shows a first embodiment of the present invention. FIG.
Then, when performing the program operation, after the program is read and the block composition processing of the present invention is performed, the program analysis is performed as usual, interpolation of straight lines and circular arcs is performed, and the movement amount of the program block is determined for each distribution cycle. Servo control is performed on each feed axis after the movement pulses are distributed to the axes. The feature of this method is that the block synthesis processing is executed while performing a program operation. FIG.
Then, once the block composition processing is performed, the program is stored in the memory, and then the program operation by the composed program is performed. This method is characterized in that the block synthesizing process is executed in advance before performing the program operation.

Next, the block synthesizing process of the present invention will be described with reference to FIGS. In the figure, n represents the number of blocks that are combined. When the program operation is started, first, one block of the program is read (S1), and it is determined whether the block is a linear interpolation movement command block (S2). If it is not a linear interpolation transfer command block in S2, and if n> 0 (S3), there are blocks in the middle of composition, so these composition vectors are transferred as composition blocks to the program analysis processing unit (S4) (S5). , The current block is transferred to the program analysis processing section (S6), n = 0 is set (S7), and the next block is read (S1). If n = 0 in S3, block composition has not been performed, so the current block is transferred to the program analysis processing unit (S6), n = 0 is set, and (S7) the next block is read (S1).

In the case of a linear interpolation block in S2, if n = 0 (S8), the current block is set as the starting point and the current block is set as the first combined vector (S9), and n = 1.
(S10), the next block is read (S1). S
If n> 0 in 8, increase n by 1 (S11),
The direction vector of this block is added to the current direction vector (S12). At this time, if n is equal to the set maximum value (S13), the combined vector up to the present is set as a combined block (S14) and transferred to the program analysis processing unit (S5). After the transfer, n = 0 is set (S7), and the next block is read (S1). If n is less than the set maximum value in S13, the tolerance between the combined vector from the starting point and the trajectory of the block before combining is obtained (S1).
5). If the tolerance is equal to or less than the allowable value (S16), the next block is read (S1). If the tolerance is greater than the allowable value in S16, the previous (n-1) combined vector is set as a combined block (S17) and transferred to the program analysis processing unit (S5). Further, the end point of the combined block is set as a new starting point (S18), the direction vector of this block is set as the first combined vector (S19), and n = 1.
(S10), the next block is read (S1).
In this way, the block synthesizing process is executed.

Finally, a method of obtaining tolerance will be described with reference to FIG. FIG. 5 shows a case where points P0 to P5 are divided into 5 blocks by the machining program. Here, a method of obtaining the tolerance Tr will be described by taking as an example the case where the blocks from the points P0 to P4 are combined. In this case, the values of the respective tolerances Tr1, Tr2, Tr3 at the points P1, P2, P3 are obtained, and the largest tolerance among them can be used as the tolerance Tr in the block combination in this case.

Here, the tolerance Tr at the point P2
The method for obtaining 2 will be described.

[Equation 1] Since it is the distance between the points P0 and P2, it can be easily obtained from the coordinate values of the machining program.

Further, when the inner product is used, the relation of the following expression 4 is obtained.

[Equation 2] By substituting the result of Expression 4 into Expression 3, the tolerance value at the point P2 can be obtained.

In this way, the tolerance Tr of the point P2
Similar to 2, the tolerances Tr1 and T at the points P1 and P3
r3 is found, and the largest tolerance among Tr1 to Tr3 is the combined vector

(Equation 3) Used as a tolerance against. Even when the number of blocks to be combined is larger, it can be obtained in the same manner as in the case of FIG.

Next, a second embodiment of the present invention will be described. In the first embodiment, after the moving amount of the block after the starting point is combined, the maximum value of the tolerance between the vector of the combined moving amount and the trajectory of the block before the combining is less than or equal to a preset value. Whether or not to combine is determined based on the above, but in the second embodiment, the vector connecting the starting point and the next point is used as a reference, and the starting point for the vector and the points after the next point are set. The angle of the vector connecting the two is determined, and whether the combination is performed or not is determined if the angle is less than or equal to a preset angle. FIG. 9 shows an example of this, and the reference vector

(Equation 4) The synthesized vector for

(Equation 5) If the angle θ1 formed by is smaller than the preset angle,
Subsequent vector

(Equation 6) The same comparison is performed with respect to, and processing is performed to combine up to the block immediately before the angle becomes larger than a preset angle. The angle is calculated by the coordinates of the starting point (x
₀ , y ₀ ) and the coordinates (x _n , y _n ) of the reference point, the arc tangent (θ _n = tan ⁻¹ ((y ₀ −y _n ) / (x ₀ −x _n )) In addition, the arctangent can be obtained from the coordinates of the combined vector, and the difference can be used as the angle to be determined.

[0018]

As described above, according to the present invention, the program blocks are combined within the allowable tolerance range to form one block of the movement command block. Therefore, in the program analysis processing section of the numerical controller, The number of program blocks to be analyzed per unit time can be reduced, and the efficiency of program analysis processing can be improved. High-speed processing can be performed within. Further, since this block composition processing can be executed in advance by an external personal computer or the like in addition to being executed in the memory operation processing of the numerical control apparatus, a numerical control apparatus not equipped with this block composition processing Also in this case, if the operation is performed using the program in which the main block composition is performed, it is possible to obtain the same effect as that of the numerical controller equipped with the main block composition processing. In this block synthesis processing, the upper limit is set for the number of blocks to be synthesized, so
It is possible to prevent the processing of the numerical control device from being interrupted as a result of continuing the block synthesis endlessly when the set value of the allowable tolerance is large. Furthermore, when creating a three-dimensional free-form surface program, it is possible to shorten the program creation time by creating only the finishing machining program. In addition, it is executed by automatic analysis and automatic program synthesis using the finishing program. Since the moving distance of the block becomes long, the processing can be performed within the range of the block processing capacity of the numerical control device, and the feed rate can be increased to perform the processing.

[Brief description of drawings]

FIG. 1 is a numerical control processing flow of the present invention.

FIG. 2 is a numerical control processing flow of the first embodiment of the present invention.

FIG. 3 is a block synthesis processing flow of the first embodiment of the present invention.

FIG. 4 is a block synthesis processing flow of the first embodiment of the present invention.

FIG. 5 is a diagram showing the tolerance of the first embodiment of the present invention.

FIG. 6 is a diagram showing the tolerance of the first embodiment of the present invention.

FIG. 7 is a diagram showing the tolerance of the first embodiment of the present invention.

FIG. 8 is a diagram showing the tolerance of the first embodiment of the present invention.

FIG. 9 is a diagram showing the tolerance of the second embodiment of the present invention.

FIG. 10 is a conventional numerical control processing flow.

Claims (5)

[Claims] 1. A block of a numerical control device such as a machine tool or a robot having two or more drive axes and moving while linearly interpolating a program consisting of a plurality of given moving blocks with line segments per distribution cycle. In the data processing method, the moving amount of the block after the starting point is combined, and the maximum value of the tolerance between the vector of the combined moving amount and the trajectory of the block before combining is less than or equal to a preset value. For example, the block data processing method of a numerical controller characterized in that the synthesized block is defined once again as one block. 2. A block of a numerical control device such as a machine tool or a robot which has two or more drive axes and moves while linearly interpolating a program consisting of a plurality of given moving blocks with line segments per distribution cycle. In the data processing method, the moving amount of the block after the starting point is combined, and if the angle formed by the vector of the combined moving amount and the vector of the block before combining is less than or equal to a preset value, The block data processing method of a numerical controller characterized in that the synthesized block is defined once again as one block. 3. The block data processing method for a numerical control device according to claim 1, wherein the block data processing is performed before the numerical control device performs a program analysis during a program operation. 4. The block data processing is performed before the numerical control device executes a program operation, and when the program operation is performed, the operation is performed by the program of the combined block. 3. A block data processing method for a numerical controller according to 1 or 2. 5. The block data processing method for a numerical controller according to claim 1, wherein the number of blocks to be combined has an upper limit of a preset value.