CN116009472A

CN116009472A - Calculation method, device and control method for rotation center of 3+2 axis CNC equipment

Info

Publication number: CN116009472A
Application number: CN202210343475.5A
Authority: CN
Inventors: 梁月德; 陈纲; 钟日新; 廖长银; 朱凯锋
Original assignee: Dongguan Everwin Precision Technology Co Ltd
Current assignee: Dongguan Everwin Precision Technology Co Ltd
Priority date: 2022-03-31
Filing date: 2022-03-31
Publication date: 2023-04-25

Abstract

The invention discloses a calculation method, a device and a control method of a rotation center of a 3+2-axis CNC device, comprising the steps of determining a reference point on a CNC device processing platform, and obtaining an initial coordinate of the reference point and a target coordinate rotated by a preset angle; respectively calculating a first distance of the initial coordinate and the target coordinate moving along a first direction and a second distance of the initial coordinate and the target coordinate moving along a second direction; and calculating the rotation center coordinate of the CNC equipment according to the first distance and the second distance and combining the initial coordinate or the target coordinate so as to calculate the rotation center coordinate of the rotation shaft with the least rotation times, thereby reducing detection errors caused by fit gaps of parts in rotation and further improving the calculation accuracy of the rotation center coordinate.

Description

Calculation method, device and control method for rotation center of 3+2 axis CNC equipment

Technical Field

The invention relates to the technical field of CNC equipment rotation center calculation, in particular to a calculation method, a device and a control method of a 3+2 axis CNC equipment rotation center.

Background

After the fixture is corrected, the rotation centers of the B axis and the C axis of the 3+2 axis CNC equipment are changed, so that before the workpiece is machined after each correction, the rotation centers of the B axis and the C axis of the rotation axis are determined, the feeding amount of the machining platform and the fixture is set based on the rotation centers when the workpiece is machined, and the machining precision is improved. When the B shaft and the C shaft of the traditional 3+2-shaft CNC equipment rotate in the forward direction and the reverse direction, parts such as gears and the like in the B shaft and the C shaft rotate in a matched mode, but due to the fact that fit gaps exist between the parts, the B shaft or the C shaft can exhibit reaction hysteresis during rotation, rotation precision of a rotating shaft is affected, reverse gap difference is generated, and therefore the rotation precision of the rotating shaft can be effectively improved by keeping the rotation of the B shaft and the C shaft in the same direction as much as possible during rotation.

Currently, when determining the rotation centers of the B axis and the C axis, for determining the rotation center of the B axis, three coordinates are usually detected, namely, coordinates of corresponding points when the B axis rotates by 0 °, +90° and-90 ° respectively, and for determining the rotation center of the C axis, four coordinates are usually detected, namely, two coordinates are detected when the C axis rotates by 0 ° and 180 ° respectively, so that the rotation times of the B axis and the C axis are more, reverse gap difference generated by the rotation of the B axis or the C axis is easily caused, the error of the coordinate detection value is larger, and when the erection height of the fixture is too high or too wide and too long, the travel of the B axis and the C axis is insufficient when the B axis rotates and cannot detect the coordinates when the corresponding angles rotate, and the operation is complex and the working efficiency is lower.

Disclosure of Invention

Accordingly, the present invention is directed to a method, an apparatus and a control method for calculating a rotation center of a 3+2 axis CNC device, so as to solve the problem in the prior art that the detection accuracy is not high and the stroke is not enough due to the large number of rotations.

To achieve the above object, a first aspect of the present invention provides a method for calculating a rotation center of a 3+2 axis CNC device, including the steps of:

determining a reference point on a CNC equipment processing platform, and acquiring an initial coordinate of the reference point and a target coordinate rotated by a preset angle;

respectively calculating a first distance of the initial coordinate and the target coordinate moving along a first direction and a second distance of the initial coordinate and the target coordinate moving along a second direction;

and calculating the rotation center coordinate of the CNC equipment according to the first distance and the second distance and combining the initial coordinate or the target coordinate.

Further, the motion axes of the CNC equipment machining platform comprise translation axes X, Y and C and rotation axes B and C, and the rotation center of the CNC equipment comprises a C axis rotation center vertical to an XY plane and a B axis rotation center vertical to a YZ plane;

in the step of determining a reference point on a CNC equipment processing platform and obtaining an initial coordinate and a target coordinate of the reference point after rotating by a preset angle, an optical probe for detecting the initial coordinate or the target coordinate and a control system connected with the optical probe and used for controlling the optical probe to move and outputting the initial coordinate or the target coordinate are adopted, wherein the initial coordinate and the target coordinate respectively comprise a first initial coordinate and a first target coordinate which are positioned in an XY plane and a second initial coordinate and a second target coordinate which are positioned in a YZ plane;

the method for acquiring the initial coordinates or the target coordinates of the reference points comprises the following steps:

controlling the optical probe to move to a first initial position of a reference point and contact with the reference point, and outputting a first initial coordinate of the reference point in an XY plane by a control system; rotating the processing platform along the C axis by a preset angle, controlling the optical probe to move to a first target position of the reference point and contact with the reference point, and outputting a first target coordinate of the reference point in an XY plane by the control system;

and/or

Controlling the optical probe to move to a second initial position of the reference point and contact with the reference point, and outputting a second initial coordinate of the reference point in the YZ plane by a control system; and rotating the processing platform along the B axis by a preset angle, controlling the optical probe to move to a second target position of the reference point and contact with the reference point, and outputting a second target coordinate of the reference point in the YZ plane by the control system.

Further, in the step of calculating a first distance by which the initial coordinate and the target coordinate move in a first direction and a second distance by which the initial coordinate and the target coordinate move in a second direction, respectively, the first direction includes an X-axis direction on an XY plane and a first Y-axis direction on a YZ plane, the first distance includes an X-axis distance on the XY plane and a first Y-axis distance on the YZ plane, the second direction includes a second Y-axis direction on the XY plane and a Z-axis direction on the YZ plane, and the second distance includes a second Y-axis distance on the XY plane and a Z-axis distance on the YZ plane;

when calculating the C-axis rotation center, the X-axis distance and the second Y-axis distance in the XY plane are calculated by the following formulas:

L _C1 ＝|X _C1 -X _C2 |；

L _C2 ＝|Y _C1 -Y _C2 |；

wherein: l (L) _C1 ,L _C2 X-axis distance and second Y-axis distance in XY plane, respectively, (X) _C1 ,Y _C1 ) Is the first initial coordinate in the XY plane, (X _C2 ,Y _C2 ) A first destination coordinate in the XY plane;

when calculating the rotation center of the B axis, the first Y axis distance and the Z axis distance in the YZ plane are respectively calculated by the following formulas:

L _B1 ＝|Y _B1 -Y _B2 |；

L _B2 ＝|Z _B1 -Z _B2 |；

wherein: l (L) _B1 ,L _B2 First Y-axis distance and Z-axis distance in YZ plane, respectively, (Y) _B1 ,Z _B1 ) Is the second initial coordinate in the XY plane, (Y _B2 ,Z _B2 ) Is the second destination coordinate in the YZ plane.

Further, in the step of calculating the rotation center coordinates of the CNC device according to the first distance and the second distance in combination with the initial coordinates or the destination coordinates, the method includes the following sub-steps:

calculating an included angle between a connecting line of the initial coordinate and the target coordinate and a first direction and a distance from the initial coordinate or the target coordinate to a rotation center of CNC equipment according to the first distance and the second distance;

and calculating to obtain the rotation center coordinate of the CNC equipment according to the included angle between the connecting line of the initial coordinate and the target coordinate and the first direction and the distance between the initial coordinate or the target coordinate and the rotation center of the CNC equipment and combining the initial coordinate or the target coordinate.

Further, in the step of calculating the included angle between the connection line of the initial coordinate and the target coordinate and the first direction according to the first distance and the second distance, and the distance between the initial coordinate or the target coordinate and the rotation center of the CNC device, when calculating the C-axis rotation center, the included angle between the connection line of the initial coordinate and the target coordinate and the first direction is calculated by the following formula:

∠a ₁ ＝ATAN(L _C2 /L _C1 )；

wherein: angle a ₁ Is the included angle between the connecting line of the first initial coordinate and the first target coordinate in the XY plane and the second Y-axis direction, L _C1 ,L _C2 X-axis distance and second Y-axis distance in XY plane;

when the rotation center of the B axis is calculated, the included angle between the connecting line of the initial coordinate and the target coordinate and the first direction is calculated by the following formula:

∠a ₂ ＝ATAN(L _B2 /L _B1 )；

wherein: angle a ₂ Is the included angle between the connecting line of the second initial coordinate and the second target coordinate in the XY plane and the first Y-axis direction, L _B1 ,L _B2 The first Y-axis distance and the Z-axis distance in the YZ plane respectively.

Further, in the step of calculating the included angle between the line of the initial coordinate and the target coordinate and the first direction according to the first distance and the second distance, and the distance from the initial coordinate or the target coordinate to the rotation center of the CNC device, when calculating the rotation center of the C-axis, the distance from the initial coordinate or the target coordinate to the rotation center of the CNC device is calculated by the following formula:

wherein: r is R _C L is the distance from the first initial coordinate or the first target coordinate to the rotation center of the C axis _C1 ,L _C2 X-axis distance and second Y-axis distance in XY plane;

when calculating the rotation center of the B axis, the distance from the initial coordinate or the target coordinate to the rotation center of the CNC equipment is calculated by the following formula:

wherein: r is R _B L is the distance from the second initial coordinate or the second target coordinate to the rotation center of the B axis _B1 ,L _B2 The first Y-axis distance and the Z-axis distance in the YZ plane respectively.

Further, in the step of calculating the rotation center coordinate of the CNC device according to the included angle between the connection line of the initial coordinate and the target coordinate and the first direction and the distance from the initial coordinate or the target coordinate to the rotation center of the CNC device, by combining the initial coordinate or the target coordinate, the C-axis rotation center coordinate of the CNC device is calculated by the following formula:

or (b)

Wherein: (X) _CO ,Y _CO ),(X _CO ',Y _CO ') are respectively adopted by the first initial coordinates (X _C1 ,Y _C1 ) And a first destination coordinate (X _C2 ,Y _C2 ) The calculated C-axis rotation center coordinate, R _C For the first initial coordinate or the first target coordinate to the C-axis rotation centerDistance of < a- ₁ The included angle between the connecting line of the first initial coordinate and the first target coordinate in the XY plane and the second Y-axis direction;

the B-axis rotation center coordinate of the CNC equipment is calculated by the following formula:

or (b)

Wherein: (Y) _BO ,Z _BO ),(Y _BO ',Z _BO ') are respectively adopted by the second initial coordinates (Y) _B1 ,Z _B1 ) And a second destination coordinate (Y _B2 ,Z _B2 ) The calculated rotation center coordinates of the B axis, R _B For the distance from the second initial coordinate or the second target coordinate to the rotation center of the B axis, the angle a ₂ Is the included angle between the connecting line of the second initial coordinate and the second target coordinate in the XY plane and the first Y-axis direction.

A second aspect of the present invention provides a computing device for computing a center of rotation of a 3+2 axis CNC device, for computing a center of rotation of a B axis and/or a C axis of the CNC device, comprising:

the optical probe is in timely contact with the corresponding position of the processing platform on the CNC equipment and is used for detecting the position coordinate of the corresponding position of the processing platform;

the control system is connected with the optical probe and the CNC equipment and is used for controlling the optical probe to move, outputting the position coordinates detected by the optical probe and controlling the CNC equipment to act; and

and the computing system is connected with the control system and is used for computing the rotation center coordinates of the B axis and/or the C axis of the CNC equipment according to the position coordinates.

Furthermore, the optical probe is also used for detecting the initial coordinate of any reference point of the processing platform on CNC equipment and the target coordinate after rotating by a preset angle;

the computing system is further used for respectively computing a first distance between the initial coordinate and the target coordinate along a first direction and a second distance between the initial coordinate and the target coordinate along a second direction, computing an included angle between a connecting line of the initial coordinate and the target coordinate and the first direction and a distance between the initial coordinate or the target coordinate and a rotation center of the CNC equipment according to the first distance and the second distance, and further computing and obtaining the B-axis and/or C-axis rotation center coordinates of the CNC equipment.

A third aspect of the present invention provides a control method of a 3+2 axis CNC device, including the steps of:

calculating the rotation center coordinates of the rotation shaft of the CNC equipment by adopting the calculation method of the rotation center of the 3+2-axis CNC equipment;

and setting the feed amount of a machining platform and a clamp of the CNC equipment based on the rotation center coordinates.

According to the invention, the initial coordinates of the reference point on the processing platform at the initial position and the target coordinates corresponding to the reference point after the B axis and the C axis rotate by a preset angle are detected, and the rotation centers of the B axis and the C axis are calculated according to the initial coordinates, the target coordinates and the preset angle of rotation respectively, and the B axis and the C axis only need to rotate once in the whole process, so that the reverse clearance error caused by multiple rotations is reduced, and the detection precision and the working efficiency are improved; and the rotation amplitude of the B shaft and the C shaft is smaller, so that the problem that the detection cannot be performed due to the size of the clamp can be effectively solved.

Drawings

Fig. 1 is a flowchart of a method for calculating a rotation center of a 3+2 axis CNC device according to embodiment 1 of the present invention.

FIG. 2 is a flowchart of a method for calculating a rotation center of a 3+2 axis CNC device according to embodiment 2 of the present invention.

Fig. 3 is a schematic diagram of the first initial coordinate and the first destination coordinate in the XY coordinate system in embodiment 2 of the present invention.

FIG. 4 is a flowchart of a method for calculating the rotation center of a 3+2 axis CNC device according to embodiment 3 of the present invention.

Fig. 5 is a schematic diagram of the second initial coordinate and the second destination coordinate in the YZ coordinate system in embodiment 3 of the present invention.

FIG. 6 is a control block diagram of a calculation device for the rotation center of a 3+2 axis CNC apparatus according to embodiment 4 of the present invention.

FIG. 7 is a schematic diagram of the CNC apparatus of FIG. 6.

FIG. 8 is a flow chart of a control method of a 3+2 axis CNC device according to embodiment 5 of the present invention.

Detailed Description

The following is a further detailed description of the embodiments:

example 1

Fig. 1 is a flowchart of a method for calculating a rotation center of a 3+2 axis CNC device according to the present embodiment. The embodiment comprises the following steps:

s101: the initial and destination coordinates of any reference point on the process platform 12 are obtained.

Firstly, arbitrarily determining a point on a processing platform 12 of CNC equipment 1 as a reference point, and marking the reference point; in this embodiment, the reference point may be marked manually, so as to effectively improve the calculation efficiency of the rotation center coordinate. Of course, in other embodiments, to further increase the accuracy of the calculation, the reference point may also be marked by programming based on the coordinate system of the machining platform 12 of the CNC apparatus 1.

Then, the position coordinates of the reference point are detected as initial coordinates (M ₁ ,N ₁ ) And the rotation axis of the processing platform 12 is rotated clockwise or counterclockwise by a predetermined angle, and the position coordinates of the reference point are detected again as the target coordinates (M ₂ ,N ₂ ). In this embodiment, the preset angle is 90 ° for ease of calculation, and of course, in other embodiments, the preset angle is not limited to 90 °, but may be 30 ° or 180 °, and so on.

In the present embodiment, the initial coordinates (M ₁ ,N ₁ ) And destination coordinates (M) ₂ ,N ₂ ) Probing with a probing device connected to the CNC apparatus 1, said probing device comprising an optical probe 2 and a control system 3 connected to the optical probe 2, said probing device comprisingThe optical probe 2 can be timely close to or far away from the processing platform 12 of the CNC equipment 1 under the control of the control system 3, and generates a detection signal to be sent to the control system 3 when the optical probe 2 is close to or contacted with the processing platform 12, and the control system 3 can also receive the detection signal sent by the optical probe 2 to convert the detection signal into corresponding position coordinates for output.

S102: and calculating the distance between the initial coordinate and the target coordinate along the corresponding direction.

Respectively calculate the initial coordinates (M ₁ ,N ₁ ) To the rotated destination coordinates (M ₂ ,N ₂ ) A distance between the two in the corresponding direction; specifically, the corresponding direction includes a first direction and a second direction, and the moving distance includes a first distance and a second distance, wherein the first direction is an initial coordinate (M ₁ ,N ₁ ) Coordinate with destination (M) ₂ ,N ₂ ) Along the direction of movement of the abscissa M, i.e. M ₁ →M ₂ The first distance is the initial coordinate (M ₁ ,N ₁ ) Coordinate with destination (M) ₂ ,N ₂ ) A distance along the direction of the abscissa M, the second direction being the initial coordinate (M ₁ ,N ₁ ) Coordinate with destination (M) ₂ ,N ₂ ) Along the direction of movement of the ordinate N, i.e. N ₁ →N ₂ The second distance is the initial coordinate (M ₁ ,N ₁ ) Coordinate with destination (M) ₂ ,N ₂ ) Distance moved in the direction of the abscissa N. Correspondingly, the first distance L ₁ And a second distance L ₂ The method is calculated by the following formulas:

L ₁ ＝|M ₁ -M ₂ | (1)

L ₂ ＝|N ₁ -N ₂ | (2)

s103: and calculating the rotation center coordinate according to the first distance, the second distance, the initial coordinate and the target coordinate.

According to the first distance L ₁ And a second distance L ₂ And combined with the initial coordinates (M ₁ ,N ₁ ) Or destination coordinates (M) ₂ ,N ₂ ) Meter with a meter bodyCalculating the rotation center coordinates of the CNC equipment 1.

Specifically, the initial coordinates (M ₁ ,N ₁ ) And destination coordinates (M) ₂ ,N ₂ ) The method is characterized in that the method is represented in a plane coordinate system, wherein the transverse axis of the coordinate system is a first direction, the longitudinal axis of the coordinate system is a second direction, and the origin of coordinates is a rotation center; connecting initial coordinates (M ₁ ,N ₁ ) And destination coordinates (M) ₂ ,N ₂ ) And combine with the first distance L ₁ And a second distance L ₂ Calculating the initial coordinates (M using trigonometric function theory ₁ ,N ₁ ) Coordinate with destination (M) ₂ ,N ₂ ) An included angle θ between the connection line of (a) and the first direction:

when the reference point rotates around the rotation axis, the motion track is a circle with the rotation center (namely the origin of coordinates) as the center, the included angle between the connection line from the initial coordinate to the rotation center and the connection line from the target coordinate to the rotation center is the preset angle (namely 90 °), and the connection line from the initial coordinate and the target coordinate to the rotation center is equal in length (the connection line is the radius of the circle with the rotation center as the center), so that the initial coordinate, the target coordinate and the rotation center are connected to form an isosceles right triangle (when the preset angle is other angles, the isosceles right triangle is formed), and according to the property of the isosceles right triangle, the initial coordinate (M) can be calculated ₁ ,N ₁ ) Or destination coordinates (M) ₂ ,N ₂ ) Distance R to rotation center:

finally, according to the initial coordinates (M ₁ ,N ₁ ) Coordinate with destination (M) ₂ ,N ₂ ) Included angle θ between the line of (c) and the first direction and initial coordinate (M ₁ ,N ₁ ) Or destination coordinates (M) ₂ ,N ₂ ) The distance R to the center of rotation of the CNC device 1 is calculated using trigonometric theoryObtaining a rotation center coordinate of the CNC apparatus 1 according to the selected initial coordinate (M ₁ ,N ₁ ) Coordinate with destination (M) ₂ ,N ₂ ) The quadrants falling in the plane coordinate system have slight differences in calculation formulas, and the detailed description refers to the subsequent embodiments, which are not repeated in this embodiment.

The calculation method of the rotation center of the 3+2 axis CNC equipment of the embodiment is realized based on trigonometric function theory, by rotating the processing platform 12 of the CNC equipment 1 around a rotation axis once, respectively detecting initial coordinates and target coordinates before and after rotation, and calculating to obtain rotation center coordinates according to the initial coordinates, the target coordinates and the rotation angles, so as to set the feed amount of the processing platform 12 and the clamp 14 of the CNC equipment 1 according to the calculated rotation center coordinates, thereby improving the processing precision; the whole process of the processing platform 12 rotates once in one direction, so that reverse gap errors caused by rotation can be effectively reduced, and the detection precision is improved; and the rotation amplitude of the rotation shaft is smaller, so that the problem that no detection can not be performed due to the size of the clamp 14 can be effectively solved.

The motion axes of the machining platform 12 of the 3+2 axis CNC equipment 1 comprise a translation axis X axis, a Y axis and a Z axis, and a rotation axis B axis and a rotation axis C axis, wherein the translation axis X axis, the Y axis and the Z axis are that a clamp 14 on the machining platform 12 can translate along the X axis, the Y axis and the Z axis so as to machine a workpiece, and the rotation axis B axis and the rotation axis C axis are that the clamp 14 on the machining platform 12 (or the machining platform 12) can rotate around the B axis and the C axis so as to machine the workpiece; the X axis, the Y axis and the Z axis form a three-dimensional coordinate system, and the three-dimensional coordinate system is provided with an XY plane, an XZ plane and a YZ plane, wherein the B axis is perpendicular to the YZ plane, and the C axis is perpendicular to the XY plane.

For the 3+2 axis CNC device 1 according to the present invention, in a specific implementation, the rotation center coordinates of the B axis and the C axis need to be calculated respectively, and for the rotation axes on which the rotation center coordinates are calculated to be different, the initial coordinates and the destination coordinates respectively include a first initial coordinate and a first destination coordinate on the XY plane when the rotation center of the C axis is calculated, and a second initial coordinate and a second destination coordinate on the YZ plane when the rotation center of the B axis is calculated, and similarly, the first direction includes an X axis direction on the XY plane and a first Y axis direction on the YZ plane, the first distance includes an X axis distance on the XY plane and a first Y axis distance on the YZ plane, and the second direction includes a second Y axis direction on the XY plane and a Z axis direction on the YZ plane, and the second distance includes a second Y axis distance on the XY plane and a Z axis distance on the YZ plane.

The following is a further detailed description of the method for calculating the rotation center coordinates of the specific rotation axis, which is specifically as follows:

example 2

Fig. 2 is a flowchart of a method for calculating the rotation center of the 3+2 axis CNC device according to the present embodiment. The present embodiment includes the same or similar method as the steps and functions of embodiment 1 for calculating the C-axis rotation center coordinates of the CNC apparatus 1, and specifically includes the steps of:

s201: first initial coordinates and first destination coordinates in the XY plane are detected.

As shown in fig. 3, a first reference point is determined on the machining stage 12 of the CNC device 1, the optical probe 2 is controlled to move to and contact a first initial position a of the first reference point, and a first initial coordinate (X _C1 ,Y _C1 ). Then, the processing stage 12 is rotated counterclockwise by 90 ° along the C-axis, and the optical probe 2 is controlled to move to and contact with the first destination position B of the rotated first reference point, and a first destination coordinate (X _C2 ,Y _C2 )。

S202: an X-axis distance and a second Y-axis distance are calculated.

Specifically, the first initial coordinates (X _C1 ,Y _C1 ) With the first destination coordinate (X _C2 ,Y _C2 ) An X-axis distance moving in the X-axis direction (i.e., the X-axis distance from point a to point B in fig. 3) and a second Y-axis distance moving in the second Y-axis direction (i.e., the second Y-axis distance from point a to point B in fig. 3); wherein the X-axis distance is the length of BC, the second Y-axis distance is the length of AC, and the X-axis distance and the second Y-axis distance pass through respectivelyThe following formula is calculated:

L _C1 ＝|X _C1 -X _C2 | (5)

L _C2 ＝|Y _C1 -Y _C2 | (6)

wherein: l (L) _C1 ,L _C2 The X-axis distance and the second Y-axis distance in the XY plane, respectively.

S203: and calculating an included angle between the first initial coordinate and the first target coordinate and between the first target coordinate and the second Y-axis direction.

According to the X-axis distance L in the XY plane _C1 And a second Y-axis distance L _C2 Using an arctangent function, the first initial coordinates (X _C1 ,Y _C1 ) With the first destination coordinate (X _C2 ,Y _C2 ) The included angle between the connection line AB of the (B) and the second Y-axis direction is less than a ₁ (i.e., the angle between AB and AC in fig. 3 +.bac):

∠a ₁ ＝ATAN(L _C2 /L _C1 ) (7)

s204: and calculating the distance from the first initial coordinate or the first target coordinate to the rotation center of the C axis.

When the processing table 12 rotates about the C-axis, the first reference point has a rotation locus of +.O with a radius of the first initial coordinate (X _C1 ,Y _C1 ) Or first destination coordinates (X _C2 ,Y _C2 ) The distance to the center O (i.e. the distance AO or BO from the origin O of the point a or point B coordinates) is isosceles right triangle, Δaob being an isosceles right triangle, depending on the nature of the right triangle, since the C-axis is rotated 90 ° counterclockwise (i.e. < aob=90°).

AO ² +BO ² ＝BC ² +AB ² (8)

Since ao=bo, and bc=l _C1 ，AB＝L _C2 Substituting the above formula (8), and obtaining a first initial coordinate (X _C1 ,Y _C1 ) Or first destination coordinates (X _C2 ,Y _C2 ) Distance to C-axis rotation center O of CNC device 1:

wherein: r is R _C For the first initial coordinate (X _C1 ,Y _C1 ) Or first destination coordinates (X _C2 ,Y _C2 ) Distance to C-axis rotation center O, R _C ＝AO＝BO。

S205: the C-axis rotation center coordinates of the CNC device 1 are calculated.

According to the first initial coordinates (X _C1 ,Y _C1 ) With the first destination coordinate (X _C2 ,Y _C2 ) The included angle between the connection line AB of the (B) and the second Y-axis direction is less than a ₁ And a first initial coordinate (X _C1 ,Y _C1 ) Or first destination coordinates (X _C2 ,Y _C2 ) Distance R to center of rotation O of CNC device 1 _C And combined with the first initial coordinates (X _C1 ,Y _C1 ) Or first destination coordinates (X _C2 ,Y _C2 ) A C-axis rotation center coordinate (X _CO ,Y _CO )。

Specifically, if the first initial coordinate (X _C1 ,Y _C1 ) The C-axis rotation center coordinates are calculated, and the C-axis rotation center coordinates (X _CO ,Y _CO ) Can be expressed as:

in ΔAOD, +.b ₁ 45 °, ao=r _C ，∠OAD＝45°+∠a ₁ From this, the length of OD and AD can be calculated as:

OD＝SIN(45°+∠a ₁ )×R _C (11)

AD＝COS(45°+∠a ₁ )×R _C (12)

substituting the formula (11) and the formula (12) into the formula (10) and combining the first initial coordinates (X) _C1 ,Y _C1 ) The quadrant to which the first initial coordinate (X in this embodiment _C1 ,Y _C1 ) Belonging to quadrant II), the C-axis rotation center coordinate (X) _CO ,Y _CO ) Can representThe method comprises the following steps:

similarly, when the first initial coordinate (X _C1 ,Y _C1 ) Belongs to the I-th quadrant, the C-axis rotation center coordinate (X _CO ,Y _CO ) Can be expressed as:

when the first initial coordinate (X _C1 ,Y _C1 ) Belongs to the third quadrant, the C-axis rotation center coordinate (X _CO ,Y _CO ) Can be expressed as:

when the first initial coordinate (X _C1 ,Y _C1 ) In the IV-th quadrant, the C-axis rotation center coordinate (X _CO ,Y _CO ) Can be expressed as:

if the first destination coordinate (X _C2 ,Y _C2 ) Calculating the C-axis rotation center coordinates, the C-axis rotation center coordinates (X _CO ',Y _CO ' s) can be expressed as:

since Δboe and Δaod are equal triangles, be=ad, eo=od, integrate equation (11), equation (12) and equation (17), and combine the first destination coordinates (X _C2 ,Y _C2 ) The quadrant to which the first destination coordinate (X in this embodiment _C2 ,Y _C2 ) Belonging to quadrant I), the C-axis rotation center coordinate (X) _CO ',Y _CO ' s) are:

similarly, when the first destination coordinate (X _C2 ,Y _C2 ) In the case of the second quadrant, the C-axis rotation center coordinate (X _CO ,Y _CO ) Can be expressed as:

when the first destination coordinate (X _C2 ,Y _C2 ) Belongs to the third quadrant, the C-axis rotation center coordinate (X _CO ,Y _CO ) Can be expressed as:

when the first destination coordinate (X _C2 ,Y _C2 ) In the IV-th quadrant, the C-axis rotation center coordinate (X _CO ,Y _CO ) Can be expressed as:

according to the calculation method of the rotation center of the 3+2-axis CNC equipment, the rotation center coordinate of the C axis can be obtained through calculation according to the first initial coordinate and the first target coordinate by detecting the first initial coordinate and the first target coordinate of the XY plane, so that the rotation amount of the turntable 13 of the CNC equipment 1 is set.

Example 3

Fig. 4 is a flowchart of a method for calculating the rotation center of the 3+2 axis CNC device according to the present embodiment. The present embodiment includes the same or similar method as the steps and functions of embodiment 1 for calculating the B-axis rotation center coordinates of the CNC apparatus 1, and specifically includes the steps of:

s301: a second initial coordinate and a second destination coordinate in the YZ plane are detected.

As shown in fig. 5, a second reference point is determined on the machining stage 12 of the CNC device 1, the optical probe 2 is controlled to move to and contact a second initial position a' of the second reference point, and a second initial coordinate (Y _B1 ,Z _B1 ). The processing platform 12 is then rotated 90 ° counter-clockwise along the B-axis and the optical probe 2 is controlled to move to and in contact with a second destination position B' of the rotated second reference point, and a second destination coordinate (Y _B2 ,Z _B2 )。

S302: a first Y-axis distance and a Z-axis distance are calculated.

Specifically, the second initial coordinates (Y _B1 ,Z _B1 ) With the second destination coordinate (Y _B2 ,Z _B2 ) A first Y-axis distance along a first Y-axis direction (i.e., a first Y-axis distance from point A 'to point B' in FIG. 3) and a Z-axis distance along a Z-axis direction (i.e., a Z-axis distance from point A 'to point B' in FIG. 3); the first Y-axis distance is the length of B 'C', the Z-axis distance is the length of A 'C', and the first Y-axis distance and the Z-axis distance are respectively calculated by the following formulas:

L _B1 ＝|Y _B1 -Y _B2 | (22)

L _B2 ＝|Z _B1 -Z _B2 | (23)

wherein: l (L) _B1 ,L _B2 The first Y-axis distance and the Z-axis distance in the YZ plane respectively.

S303: and calculating an included angle between the second initial coordinate and the second target coordinate and between the second target coordinate and the first Y-axis direction.

According to the first Y-axis distance L in the YZ plane _B1 And Z-axis distance L _B2 Using an arctangent function, the second initial coordinates (Y _B1 ,Z _B1 ) With the second destination coordinate (Y _B2 ,Z _B2 ) The included angle between the connecting line A 'B' and the first Y-axis direction is +.a ₂ (i.e. in FIG. 5Angle a ' B ' C ' from B ' C '):

∠a ₂ ＝ATAN(L _B2 /L _B1 ) (24)

s304: and calculating the distance from the second initial coordinate or the second target coordinate to the rotation center of the B axis.

When the processing table 12 rotates around the B axis, the rotation locus of the second reference point is as follows +.O', the radius thereof is as the second initial coordinate (Y _B1 ,Z _B1 ) Or the second destination coordinate (Y _B2 ,Z _B2 ) The distance to the center O '(i.e. the distance a' O 'or B' O 'of the point a' or the point B 'origin of coordinates O'), Δa 'O' B 'is an isosceles right triangle, depending on the nature of the right triangle, since the B axis is rotated 90 ° counterclockwise (i.e. < a' O 'B' =90°):

A'O' ² +B'O' ² ＝B'C' ² +A'C' ² (25)

since a 'O' =b 'O', and B 'C' =l _B1 ，A’C’＝L _B2 Substituting the above formula (25) to obtain a second initial coordinate (Y _B1 ,Z _B1 ) Or the second destination coordinate (Y _B2 ,Z _B2 ) Distance to the B-axis rotation center O' of the CNC device 1:

wherein: r is R _B For the second initial coordinate (Y _B1 ,Z _B1 ) Or the second destination coordinate (Y _B2 ,Z _B2 ) Distance to rotation center O' of B axis, R _B ＝A'O'＝B'O'。

S305: the B-axis rotation center coordinates of the CNC device 1 are calculated.

According to the second initial coordinates (Y _B1 ,Z _B1 ) With the second destination coordinate (Y _B2 ,Z _B2 ) The included angle between the connecting line A 'B' and the first Y-axis direction is +.a ₂ And a second initial coordinate (Y _B1 ,Z _B1 ) Or coordinates of the first person (Y) _B2 ,Z _B2 ) Distance R to center of rotation O' of CNC device 1 _B And combined with the second initial coordinates (Y _B1 ,Z _B1 ) Or the second destination coordinate (Y _B2 ,Z _B2 ) The B-axis rotation center coordinates (Y _BO ,Z _BO )。

Specifically, if the second initial coordinate (Y _B1 ,Z _B1 ) The B-axis rotation center coordinates are calculated, and the B-axis rotation center coordinates (Y _BO ,Z _BO ) Can be expressed as:

in ΔA ' O ' D ', angle c ₂ ＝∠b ₂ ＝45°-∠a ₂ ，A'O'＝R _B From this, the lengths of O 'D' and A 'D' can be calculated as:

O'D'＝SIN(45°-∠a ₂ )×R _B (28)

A'D'＝COS(45°-∠a ₂ )×R _B (29)

substituting the formula (28) and the formula (29) into the formula (27) and combining the second initial coordinates (Y) _B1 ,Z _B1 ) The quadrant to which the second initial coordinate (Y in this embodiment _B1 ,Z _B1 ) Belonging to the IVI quadrant), the rotation center coordinate (Y) of the B axis can be obtained _BO ,Z _BO ) Can be expressed as:

similarly, when the second initial coordinate (Y _B1 ,Z _B1 ) Belonging to other image points, the rotation center coordinate of the B-axis (Y _BO ,Z _BO ) The determination rules are described in the related descriptions of embodiment 2, and the description of this embodiment is omitted.

If the second destination coordinate (Y _B2 ,Z _B2 ) Calculating the B-axis rotation center coordinates, the B-axis rotation center coordinates (Y _BO ',Z _BO ' s) can be expressed as:

since Δb 'O' E 'and Δa' O 'D' are equal triangles, B 'E' =a 'D', E 'O' =o 'D', integrate equation (28), equation (29) and equation (31), and combine the second destination coordinate (Y _B2 ,Z _B2 ) The quadrant to which the second destination coordinate (Y in this embodiment _B2 ,Z _B2 ) Belonging to quadrant I), the B-axis rotation center coordinate (Y) _BO ',Z _BO ' s) are:

similarly, when the second destination coordinate (Y _B2 ,Z _B2 ) Belonging to other image points, the rotation center coordinate of the B-axis (Y _BO ',Z _BO ') is described in the related description of embodiment 2, and the description of this embodiment is omitted.

According to the calculation method of the rotation center of the 3+2-axis CNC equipment, the rotation center coordinate of the B axis can be obtained through calculation according to the second initial coordinate and the second target coordinate by detecting the second initial coordinate and the second target coordinate of the YZ plane, so that the rotation amount of the machining platform 12 of the CNC equipment 1 is set.

In the embodiment of the present invention, the B-axis rotation center coordinates were calculated as in example 2 or the C-axis rotation center coordinates were calculated as in example 3, and the positions of the intersections (i.e., points C and C ') projected on the coordinate axes corresponding to the initial coordinates and the target coordinates in the examples were determined as in the embodiment, when the intersection was located outside the rotation locus O (i.e., point C shown in FIG. 3), the calculation was performed as in example 2, and when the intersection was located inside the rotation locus O ' (i.e., point C ' shown in FIG. 5), the calculation was performed as in example 3.

Example 4

Fig. 6 is a block diagram showing a 3+2 axis CNC device rotation center calculation apparatus according to the present embodiment. The calculating device of the rotation center of the 3+2 axis CNC device of the present embodiment is configured to execute the calculating method of the rotation center of the 3+2 axis CNC device of any one of embodiments 1 to 3, so as to calculate the rotation center coordinates of the B axis and/or the C axis of the CNC device.

As shown in fig. 7, the CNC device 1 according to this embodiment includes a base 11, a processing platform 12 rotatably disposed on the base 11, a turntable 13 rotatably disposed on the processing platform 12, and a clamp 14 slidably disposed on the turntable 13, where the CNC device 1 has a translation axis X-axis, a Y-axis and a Z-axis, and a rotation axis B-axis and a C-axis, in this embodiment, the X-axis is an axis parallel to the length direction of the CNC device 1, the Y-axis is an axis parallel to the width direction of the CNC device 1, the Z-axis is an axis parallel to the height direction of the CNC device 1, the X-axis, the Y-axis and the Z-axis are mutually perpendicular and can form an XY plane, an XZ plane and an YZ plane, the B-axis is perpendicular to the YZ plane, and the C-axis is perpendicular to the XY plane. The clamp 14 can move on the turntable 13 along the X-axis, Y-axis and Z-axis directions of the translation axis, the processing platform 12 can rotate around the B-axis, and the turntable 13 can rotate around the C-axis so as to realize multi-axis processing on a workpiece clamped on the clamp 14.

Specifically, the present embodiment includes an optical probe 2, a control system 3, and a computing system 4, in which:

the optical probe 2 is electrically connected to the control system 3 and can be moved towards and away from the machining platform 12 of the CNC device 1 under the control of the control system 3, the optical probe 2 has a photosensitive element (not shown in the figure) which detects the contact action and generates a detection signal to the control system 3 when the optical probe 2 is in contact with the corresponding position of the machining platform 12. Specifically, the optical probe 2 detects an initial coordinate of any reference point on the processing platform 12 of the CNC device 1 and a target coordinate after rotating by a preset angle, and sends the initial coordinate and the target coordinate to the control system 3.

The control system 3 is configured to control movement of the optical probe 2, receive a detection signal sent by the optical probe 2, generate a corresponding position coordinate from the detection signal, and output the position coordinate to the computing system 4.

The control system 3 is also electrically connected to the CNC device 1 for controlling the movement or rotation of the machining platform 12 and the clamp 14 of the CNC device 1 in corresponding directions.

And the computing system 4 performs comprehensive computation according to the received initial coordinates and the target coordinates to obtain the B-axis and/or C-axis rotation center coordinates of the CNC equipment 1. Specifically, the computing system 4 calculates a first distance and a second distance that the initial coordinate and the target coordinate move along the first direction and the second direction, calculates an included angle between a connecting line of the initial coordinate and the target coordinate and the first direction and a distance between the initial coordinate or the target coordinate and a rotation center of the CNC device 1 according to the first distance and the second distance, and further calculates a B-axis and/or C-axis rotation center coordinate of the CNC device 1. For more detailed calculation, please refer to the corresponding descriptions of embodiment 1, embodiment 2 or embodiment 3, and the description of this embodiment is omitted.

According to the calculation device of the rotation center of the 3+2-axis CNC equipment, the optical probe 2 is adopted to detect the coordinates of two positions of the same reference point on the CNC equipment 1, namely the initial coordinate and the target coordinate, the initial coordinate and the target coordinate are located in the same coordinate system, the rotation center coordinate of the corresponding rotation axis can be calculated based on the relative distance of the initial coordinate and the target coordinate and combined with the trigonometric function theory, the coordinate origin of the coordinate system to which the initial coordinate and the target coordinate belong is not required to be determined, and the calculation process is simplified; and the whole process processing platform 12 only rotates once towards one direction, multiple rotations are not needed, reverse gap errors caused by rotation are reduced, the detection precision is improved, the whole calculation process is further simplified, and the work efficiency is improved.

Example 5

Fig. 8 is a flowchart of a control method of the 3+2 axis CNC device according to the present embodiment. The control method of the CNC device of the present embodiment is implemented based on the computing device of the 3+2 axis CNC device rotation center of embodiment 4, and includes the same or similar computing method as the steps and functions of embodiment 1, and optionally includes the same or similar computing method as the steps and functions of embodiment 2 and/or embodiment 3. Specifically, the embodiment includes the following steps:

s501: the rotation center coordinates of the CNC device 1 are calculated.

Specifically, the rotation center coordinates of the rotation axis (including the B axis and the C axis) of the CNC device 1 are calculated by adopting the calculation method of the rotation center of the 3+2 axis CNC device according to any one of embodiments 1 to 3; the specific calculation process refers to the method described in any one of embodiments 1 to 3, and this embodiment is not described in detail.

S502: the feed amount of the CNC equipment is set according to the rotation center coordinates of the CNC equipment 1.

The rotation center coordinates of the B axis and/or the C axis are input into the control system 4, and the control system 4 determines the feed amount of the processing platform 12, the turntable 13 and the clamp 14 according to the rotation center coordinates of the B axis and/or the C axis and the three-dimensional coordinates (i.e., coordinates corresponding to the X axis, the Y axis and the Z axis) of the CNC device 1, so as to improve the processing precision of the workpiece.

According to the CNC equipment control method, the rotation center coordinates of the rotation axis B and the rotation center coordinates of the rotation axis C of the corrected CNC equipment 1 are recalculated and determined, so that the feed amounts of the processing platform 12, the turntable 13 and the clamp 14 are set based on the rotation center coordinates, and the processing precision of a workpiece can be effectively improved.

Although the invention is preferably used for calculating the rotation center of the 3+2-axis CNC equipment or controlling the 3+2-axis CNC equipment, it is understood that the calculation method, the device or the control method of the invention can be used for determining or controlling the rotation center coordinates of other processing centers with rotation shafts, such as calculating the rotation center coordinates of the processing centers with 5-axis, 3+1-axis and 3+N-axis and controlling a machine tool, and has simple operation and wide application range.

Claims

1. The calculation method of the rotation center of the 3+2-axis CNC equipment is characterized by comprising the following steps of:

2. The method of claim 1, wherein the axes of motion of the CNC device machining platform include translational axes X, Y, and C and rotational axes B and C, the center of rotation of the CNC device including a C axis center of rotation perpendicular to the XY plane and a B axis center of rotation perpendicular to the YZ plane;

and/or

3. The method according to claim 2, wherein in the step of calculating a first distance in which the initial coordinate and the target coordinate move in a first direction and a second distance in which the initial coordinate and the target coordinate move in a second direction, respectively, the first direction includes an X-axis direction in an XY plane and a first Y-axis direction in a YZ plane, the first distance includes an X-axis distance in the XY plane and a first Y-axis distance in the YZ plane, the second direction includes a second Y-axis direction in the XY plane and a Z-axis direction in the YZ plane, and the second distance includes a second Y-axis distance in the XY plane and a Z-axis distance in the YZ plane;

L _C1 ＝|X _C1 -X _C2 |；

L _C2 ＝|Y _C1 -Y _C2 |；

L _B1 ＝|Y _B1 -Y _B2 |；

L _B2 ＝|Z _B1 -Z _B2 |；

4. A method of calculating a center of rotation of a 3+2 axis CNC device according to claim 3, wherein in the step of calculating the center of rotation coordinates of the CNC device based on the first distance and the second distance in combination with an initial coordinate or a destination coordinate, the method comprises the sub-steps of:

5. The method according to claim 4, wherein in the step of calculating the angle between the line of the initial coordinate and the destination coordinate and the first direction and the distance between the initial coordinate or the destination coordinate and the rotation center of the CNC device according to the first distance and the second distance, when calculating the C-axis rotation center, the angle between the line of the initial coordinate and the destination coordinate and the first direction is calculated by the following formula:

∠a ₁ ＝ATAN(L _C2 /L _C1 )；

∠a ₂ ＝ATAN(L _B2 /L _B1 )；

6. The method according to claim 5, wherein in the step of calculating the angle between the line of the initial coordinate and the destination coordinate and the first direction and the distance from the initial coordinate or the destination coordinate to the rotation center of the CNC device according to the first distance and the second distance, when calculating the C-axis rotation center, the distance from the initial coordinate or the destination coordinate to the rotation center of the CNC device is calculated by the following formula:

7. The method for calculating the rotation center of the 3+2 axis CNC device according to claim 6, wherein in the step of calculating the rotation center coordinate of the CNC device according to the angle between the line between the initial coordinate and the destination coordinate and the first direction and the distance between the initial coordinate or the destination coordinate and the rotation center of the CNC device in combination with the initial coordinate or the destination coordinate, the C-axis rotation center coordinate of the CNC device is calculated by the following formula:

or (b)

Wherein: (X) _CO ,Y _CO ),(X _CO ',Y _CO ') are respectively adopted by the first initial coordinates (X _C1 ,Y _C1 ) And a first destination coordinate (X _C2 ,Y _C2 ) The calculated C-axis rotation center coordinate, R _C For the distance from the first initial coordinate or the first target coordinate to the rotation center of the C axis, the angle a ₁ The included angle between the connecting line of the first initial coordinate and the first target coordinate in the XY plane and the second Y-axis direction;

or (b)

8. A computing device for computing a center of rotation of a 3+2 axis CNC device for computing a center of rotation of a B axis and/or a C axis of the CNC device, comprising:

9. The computing device of the rotational center of the CNC device according to claim 8, wherein the optical probe is further configured to detect an initial coordinate of any reference point of the machining platform on the CNC device and a target coordinate after rotating by a preset angle;

10. A control method of a 3+2 axis CNC device, comprising the steps of:

calculating the rotation center coordinates of the rotation axis of the CNC device by the calculation method of the rotation center of the 3+2 axis CNC device according to any one of claims 1 to 7;