JPS61136106A - Information method of cubic arc - Google Patents

Abstract

PURPOSE:To specify the arc command data in a single block and to shorten the tape length by performing a pulse distribution operation of the simultaneous three axes with use of the data obtained from a conversion process and then shifting a tool along an arc of a 3-dimensional plane. CONSTITUTION:For instance, the position data specifying the next position on an arc where a tool reaches from its present position after DELTAT seconds is obtained from an arc interpolation operation. Then the coordinate conversion processing is applied to the position data obtained from an arc interpolation operation based on the rotary angle data and the rotary axis data. For instance, the position data obtained from the arc interpolation (increment amount of each axis) are defined as DELTAX, DELTAY and DELTAZ (DELTAY=0) together with a plane ZX, a rotary angle (a), a rotary axis set in parallel to an axis Z and positions of the rotary axis defined as xp and yp on a plane XY respectively. Thus DELTAX', DELTAY' and DELTAZ' are obtained from the conversion of coordinates as shwn in an equation 1. Then the simultaneous 3-axis pulse distribution operation is carried out by means of data DELTAX', DELTAY' and DELTAZ' obtained from the conversion processing. Hereafter the above-mentioned processing is carried out up to the terminal point of an arc.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a three-dimensional circular arc interpolation method, and in particular, the present invention relates to a three-dimensional circular arc interpolation method, and in particular, a method for interpolating a circular arc specified by circular arc data created in a predetermined program coordinate system around a predetermined rotation axis. The present invention relates to a three-dimensional arc interpolation method in which a tool is moved along an arc formed by rotating an angle.

<Prior Art> When the workpiece surface is inclined at a predetermined angle with respect to the horizontal plane, it is not possible to obtain an arcuate shape on the workpiece surface simply by performing normal two-dimensional circular interpolation processing.

Furthermore, even if the workpiece surface is inclined, it is not possible to obtain an arcuate shape on the workpiece surface by simply applying ordinary two-dimensional circular interpolation processing.

For this reason, conventionally, an automatic programming device was used to divide the arc on the workpiece surface into a large number of tiny three-dimensional straight lines.
Three-dimensional path data is created for each straight line, and simultaneous three-axis linear interpolation calculations are performed using the three-dimensional path data to form an arc shape on the workpiece surface.

(The problem that the invention is trying to solve) However, this conventional method has the drawbacks that programming is difficult and the data length (tape length) is long.

Therefore, the purpose of the present invention is to simplify programming,
Moreover, it is an object of the present invention to provide a three-dimensional arc interpolation method that can specify an arc on an inclined surface with one block of commands, and furthermore, can form an arc shape on the inclined surface based on the command.

Means for Solving Problems> The three-dimensional circular interpolation method of the present invention includes a plane selection command for specifying a plane on which circular interpolation is to be performed, a circular interpolation command, and a rotation command for rotating the circular arc around a predetermined rotation axis. inputting angle data and data specifying the position of the rotation axis; executing a circular interpolation operation on the plane based on a circular interpolation command; and performing the circular interpolation operation on the plane based on the rotation angle data and rotation axis data. The method includes a step of performing a coordinate transformation process on the data obtained by the above, and a step of performing a simultaneous three-axis pulse distribution calculation using the data obtained by the conversion process.

Function> Plane selection commands (017 to G19) that specify the plane (XY, ZX, YZ plane) on which circular interpolation is to be performed, and circular interpolation commands (
G02 or GO3 (data specifying the circular arc), rotation angle data for rotating the circular arc around a predetermined rotation axis, and data specifying the position of the rotation axis, and the plane is adjusted based on the circular interpolation command. Executes circular interpolation calculation in . For example, position data specifying the next position on the circular arc that the tool will reach after ΔT seconds from the current position is obtained by circular interpolation calculation. Then, coordinate transformation processing is performed on the position data obtained by the circular interpolation calculation based on the rotation angle data and rotation axis data. For example, the plane is the ZX plane, the rotation angle is α, the rotation axis is parallel to the Z axis, and the position on the XY plane is x.

yp, and position data that is not disturbed by the circular interpolation.
If (incremental amount of each axis) is ΔX, ΔY1ΔZ (however, Δy=o), then the coordinates are transformed using the following formula and Δx
′, ΔY′, Δ2′. Thereafter, a simultaneous three-axis pulse distribution calculation is performed using the data ΔX', Δy/, and ΔZ' obtained by the conversion process. Thereafter, the above process is executed until the end point of the arc is reached.

<Example> FIG. 1 is a schematic explanatory diagram of the present invention. When the Zx plane (the Z axis is an axis perpendicular to the plane of the paper passing through the origin R) is rotated by a0 around the Z axis, the point P on the ZX plane moves to the point P, / on the ZX' plane, and its coordinates Value (ΔX /, ΔY
j, Δz') is the coordinate value of point P (ΔX, ΔY,
ΔZ) (where ΔY=0), it is calculated by the following formula. And generally point the axis of rotation Q
(Ray!/P#ZP) (However, if zp=O), assuming that it is a straight line parallel to the Z axis, the coordinate value of a point on the Zx' plane is calculated by the following equation. From the above, if the program path is a circular arc on the Zx plane, the position coordinate values of points on the plane are sequentially determined by circular interpolation on the Zx plane, and then the position coordinate values are used to calculate the position coordinates of each axis on the Zx plane. Find the incremental values ΔX, ΔY, ΔZ,
After that, the incremental values ΔX, ΔY, ΔZ are set to (1
b) Perform the coordinate transformation process of formula to obtain ΔX J, Δy /, Δ
If Z' is found, these Δx', ΔY L.

ΔZ′ points to ZX plane (xp# Ypl ”p)
The incremental values of each axis on the plane ZX' are obtained by rotating α0 around the axis that passes through . Then, using these incremental WΔX', ΔY', and AZ', simultaneous three-axis pulse distribution calculation is performed, and if each axis motor is moved by each axis distribution pulse, the movable part, for example, a tool, can be moved by Zx'
It will move along an arc on the plane. The above is a case where the ZX plane is rotated around the Z axis, but when rotating around the Y axis, the conversion formula is as follows, and when rotating around the X axis, it becomes .

FIG. 2 is a block diagram of a numerical control device that can realize the present invention, and FIG. 3 is a flowchart of processing. In Figure 2, 10
1 is a processor; 102 is R for storing a control program;
OM, 103 is RAM.

104 is an operation panel, 105 is a working memory, 106 is a pulse distributor, 107X, 107Y.

107Z1! Each axis servo circuit, 108X, 108Y.

]08Z is a servo motor for each axis, 109 is a machine tool, 11
0 is an interface circuit in charge of data exchange between the numerical control side and the machine tool side. The uninvented three-dimensional arc interpolation method will be explained below according to the flowchart shown in FIG.

It is assumed that the RAM 103 stores NC program data in advance.

(1) Set the mode selector switch on the operation panel 104 to memory operation mode, and press the cycle start button to start the cycle.

(2) When the processor 101 starts up, the RAM1
The NC data is sequentially read out one block at a time from 03 and the following processing is executed.

(31 That is, the processor 101 checks whether the NC data is 'MO2' indicating the end of the program,
If it is "MO2", the numerical control process ends.

(4) However, if the NC data is not “M02°°,”
The processor 101 checks whether the N'C data is circular interpolation command data.

(If it is not instruction data between 51 circular arcs, the processor 101
executes a predetermined numerical control process based on the NC data, reads out the NC data from the RAM 103 after completing the process, and executes the process from step (3) onwards.

(6) On the other hand, if it is circular interpolation instruction data, processor 1
Is 01 the following arc? Perform all processing during lt1. Note that the circular interpolation command data has the following configuration.

(al X For an arc on the Y plane (bl Z For an arc on the X plane G18 GO2(GO3)X Z I K
□F a xPypzpi...='lB) [cl
For an arc on the YZ plane, tatashi, G 17. G18. G 19 Hasoreso t
tG function commands that specify arcs in the XY plane, Zx plane, and YZ plane; GO2 and GO3 are G function commands that specify clockwise and counterclockwise circular interpolation, respectively; alphabet x
, y, and z are word addresses indicating the arc end point, and when creating NC data with absolute commands, the position coordinates of the end point, and when creating NC data with incremental commands, the position coordinates of the arc end point as seen from the arc start point. Indicates coordinate values. Also, the alphabets r, J, Kl are word address words that indicate vector components when looking at the center of the arc from the starting point of the arc, F is the word address word that indicates the moving speed, x2゜Yp
v "p' is a coordinate value indicating the position of the rotation axis for rotating the circular arc, and a is the rotation angle.

Now, if the radius of the circular arc is R1, the moving speed is F, and the rotation angle to be moved during ΔT seconds (for example, 8 rns) is Δθ, then the following formula % (4) holds true. Therefore, Δθ=F・ΔT/R (4bl) However, according to the NC data shown in (B) above, Z
Assuming that a circular arc on the x plane is commanded, the radius R
is calculated by the following formula % formula % ().

By the way, as shown in Fig. 4, the circular arc ARC on the Zx plane
is commanded, and if the position coordinate values of point P on the first arc are (x,, z,), then the point after ΔT seconds is
In other words, the position coordinate value (x, or l'j+1) of point P1 on the (i+1)th circular arc rotated by Δθ is calculated by the following formula (6).

From the above, if the NC data is circular interpolation command data on the Zx plane, the processor 101 executes the circular interpolation calculations of formulas (4b) to (6b) every ΔT seconds until reaching the circular arc end point As, and sequentially performs circular interpolation calculations on the circular arc. The coordinate values of point P, etc. are calculated. Incidentally, even when an arc on the XY plane or an arc on the YZ plane is commanded, the coordinate values of points on the arc are sequentially calculated by the same process. The following description will be made assuming that a circular arc on the Zx plane is commanded.

(7) Once the coordinates of point P1° are determined, process ν
The step 101 calculates incremental values ΔX, ΔY, and ΔZ using the following formula (7).

(8) Once the incremental values ΔX, ΔY, and ΔZ are determined, the processor 101 identifies which of the x, y, and z axes the rotation axis is parallel to. Now, the rotation axis is parallel to any of the X, Y, and Z axes, and its position is between the rotation axis and a plane perpendicular to the rotation axis (XY, YZ.

Since the axis of rotation is expressed as the coordinates of the intersection with the
If parallel to the axis, XP=0, if parallel to the Y axis, y0=0, and if parallel to the Z axis, 22=0.

Therefore, by determining the axis whose coordinate value is 0, it is possible to easily identify which axis the rotation axis is parallel to. For example, as shown in Figure 1, if an arc on the ZX plane is rotated a around an axis parallel to the Z axis passing through point Q on the XY plane, the position coordinate value of the rotation axis is ("pp !pm O]
becomes.

(9) If the rotation axis is parallel to the Z-axis according to the identification process in step (8), the processor 101 executes the coordinate transformation process of equation (1b) to obtain the three-dimensional incremental value ΔX
Calculate J, ΔY', and ΔZ'.

In addition, if it is parallel to the Y axis and X axis respectively, +21,131
Execute the coordinate transformation process of the expression.

(II Once ΔX/, ΔY', and ΔZ' are calculated, the processor 101 inputs them to the pulse distribution N106. The pulse distribution type 106 executes simultaneous three-axis pulse distribution calculation based on the input data, and calculates the distribution pulse Xp, Yp, Z
p is applied to each axis servo circuit 107X to 1072 to rotate each axis servo motor 108X to 108Z. As a result, the tool moves toward point P, which is point P1*1.

Further, the processor 101 updates the current positions X, Y, Z, and remaining movements X, Y, Z, stored in the working memory 105, using the following equation (8). However, in equations (8&) to (8c), the sign depends on the moving direction, and in equations (9a) to (9C), the initial values of x, y, and z are the values from the arc start point As to the arc end point Ae. Each axis is an incremental value.

(Ill Also, at every time ΔT, the processor 101
=Y =Z =O(101) Then, if the formula +11 is established, the processor 101 assumes that the circular interpolation calculation process has been completed, reads the next NC data from the RAM 103, and performs the processing from step (3) onward. Repeat the process. However, (
If Equation 11 does not hold, the processing from step (6) onwards is repeated.

<Effects of the Invention> As explained above, according to the present invention, a plane selection command for specifying a plane on which circular interpolation is to be performed, a circular interpolation command, rotation angle data for rotating the circular arc around a predetermined rotation axis, Inputting data specifying the position of the rotation axis, performing a circular interpolation operation on the plane based on a circular interpolation command, and performing the circular interpolation operation on the plane based on the rotation angle data and rotation axis data. This is because the data is subjected to coordinate conversion processing, and the converted data is used to perform simultaneous three-axis pulse distribution calculations to move the tool along an arc on a three-dimensional plane. , arc command data can be specified in one block, the tape length can be shortened, and even if the work surface is inclined,
Alternatively, even if the workpiece surface is mounted on a machine tool with an incline, an arcuate shape can be formed correctly on the workpiece surface.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram of the present invention, Fig. 2 is a block diagram of a numerical control device that can realize the method of the present invention, Fig. 3 is a flowchart of the processing of the present invention, and Fig. 4 is an explanatory diagram of circular interpolation calculation. be. 101... Processor, 103... RAM106.
...Pulse distributor patent applicant Fanuc Co., Ltd. agent Patent attorney Chiki Tofuji Figure 1 Figure 4 Figure 3

Claims (1)

[Claims] Input a plane selection command that specifies a plane on which circular interpolation is to be performed, a circular interpolation command, rotation angle data that rotates the arc around a predetermined rotation axis, and data that specifies the position of the rotation axis, and execute the circular interpolation command. perform a circular interpolation calculation on the plane based on the rotation angle data and the rotation axis data, perform a coordinate transformation process on the data obtained by the circular interpolation calculation based on the rotation angle data and the rotation axis data, and use the data obtained by the conversion process. A three-dimensional circular interpolation method characterized by performing pulse distribution calculation using