阅读说明：本技术 一种五轴激光加工设备rtcp误差标定补偿方法 (RTCP error calibration compensation method for five-axis laser processing equipment ) 是由 朱文宇 石涛 王三龙 李方辉 林明明 于 2020-06-04 设计创作，主要内容包括：本发明公开了一种五轴激光加工设备RTCP误差标定补偿方法,记录各旋转轴不同位置下进行标定的坐标值,并测量或计算出和旋转轴的偏移矢量及矢量数据,最后将偏移矢量和矢量数据对应的写入RTCP,通过所述RTCP内的控制系统将机床的XYZBC五轴建立关联关系。本发明可方便快捷的测量出RTCP所需矢量数值,确保激光设备使用RTCP功能,提高激光加工设备五轴联动的加工精度。(The invention discloses a RTCP error calibration compensation method for five-axis laser processing equipment, which comprises the steps of recording coordinate values for calibration under different positions of each rotating shaft, measuring or calculating an offset vector and vector data of the rotating shaft, finally writing the offset vector and the vector data into RTCP correspondingly, and establishing an incidence relation of an XYZBC five axis of a machine tool through a control system in the RTCP. The invention can conveniently and rapidly measure the vector value required by the RTCP, ensure that the laser equipment uses the RTCP function and improve the processing precision of the five-axis linkage of the laser processing equipment.)

1. A RTCP error calibration compensation method for five-axis laser processing equipment is characterized by comprising the following specific steps:

s1: correcting the B axis by taking the working table surface of the C axis as a reference, and determining the zero coordinates of the B axis by dotting test on a concentric circle by laser;

s2: installing a check rod to enable the axis of the check rod to coincide with the axis of the C-axis rotation, adjusting the check rod through a dial indicator on the Z axis to enable the check rod to be concentric with the C axis, acquiring three points of the excircle of the check rod and calculating the rotation center (X) of the C-axis turntable_C，Y_C)；

S3: measuring X-axis coordinate value X of B-axis center in YOZ plane_BAnd, moving the C-axis table to Y_CRespectively moving the workbench to the left and right sides of the equipment to acquire data X₁And X₂Then, the Z-axis coordinate value Z is calculated_B；

S4: x coordinate X of revolution center based on C axis_CAnd B-axis rotation center at X-axis coordinate X_BCalculating the difference value delta X between the rotation center of the B axis and the optical axis;

s5: measuring the diameter D of the check rod while based on the data X₁And X₂Calculating the distance R from the rotation center of the B shaft to the end face of the air tap;

s6: the data measured and calculated in steps S1 to S5 are written in RTCP, and the XYZBC five axes of the machine tool are associated.

2. The RTCP error calibration compensation method for a five-axis laser processing apparatus according to claim 1, wherein said step S1 comprises the steps of:

s11: taking the working table surface of the C axis as a reference, placing the test piece on the working table surface, and calibrating the zero point position of the B axis;

s12: if the test point deviates in the X direction, rotating the B axis for adjustment; if the test point deviates in the Y direction, adjusting by increasing or decreasing the gasket at the connection screw of the cutting head;

s13: performing concentric circle test by laser dotting after each adjustment in the step S12, and if the concentricity deviation value of the concentric circles is less than 0.01mm, determining the zero point of the B axis;

wherein, the working table surface is in a horizontal state.

3. The RTCP error calibration compensation method for five-axis laser processing equipment according to claim 2, wherein the test method in step S13 is:

s131: burning a circular burning surface on the test piece at the height of 5cm away from the test piece and with the laser power of 500W;

s132: burning a circular burning point on the test piece at the position 1-5 mm away from the test piece and with the laser power of 100W;

s133: the concentricity of the circular burned surface and the circular burned point was compared.

4. The RTCP error calibration compensation method for five-axis laser processing equipment according to claim 1, wherein said step S2 includes:

s21: mounting a test check rod in a preset reference hole for calibrating the center of the C shaft, and enabling the axis of the check rod to coincide with the axis of the C shaft rotation;

s22: placing a dial indicator on a Z axis, placing a head of the dial indicator on a side bus of the inspection rod, and striking the dial indicator along the Z axis to ensure that the indication number change in the Z axis movement process is less than 0.01mm, and indicating that the bus of the inspection rod is parallel to the Z axis movement straight line; placing the gauge outfit on a side bus of the inspection rod, rotating the C shaft for one circle, observing the numerical value change of the gauge outfit, adjusting the position of the inspection rod until the numerical value change of the gauge is less than 0.01mm when the C shaft rotates for one circle, and considering that the inspection rod is concentric with the C shaft;

s23: move the check rod under the cutting head, go to catch three points on the excircle of check rod with the camera in proper order: (X)_cn、Y_cn)，(X₂、Y₂)，(X₃、Y₃) Calculating the center of the excircle, and taking the obtained excircle center coordinate as the coordinate of the C-axis rotation center in the machine tool coordinate system (X)_C、Y_C)。

5. The RTCP error calibration compensation method for a five-axis laser processing apparatus according to claim 1, wherein said step S3 comprises the steps of:

s31: adjusting the cutting head to zero coordinate, then slowly moving the Z axis, and recording the Z axis coordinate value Z of the center of the B axis when the cutting head touches the C axis worktable surface_B；

S32: moving the C-axis table to Y_CThen moving the workbench to the left side of the equipment, returning the B axis to the zero position coordinate, rotating the B axis by 90 degrees, and then slowly moving the X axis to enable the air nozzle of the cutting head to touch a side bus of the inspection rod to obtain data X₁(ii) a Then moving the workbench to the right side of the equipment, returning the B axis to zero position coordinates, rotating the B axis to minus 90 degrees, and then slowly moving the X axis to enable the air nozzle of the cutting head to touch a side bus of the inspection rod to obtain data X₂；

Based on data X₁And X₂Calculating the coordinate of the B-axis rotation center on the X-axis: x_B＝(X₁+X₂)/2。

6. The RTCP error calibration compensation method for five-axis laser processing equipment as claimed in claim 5, wherein in the step S4, the X coordinate of the revolution center based on the C axis is X coordinate_CAnd B-axis rotation center at X-axis coordinate X_BAnd calculating the difference value between the rotation center of the B axis and the optical axis: Δ X ═ X_B-X_C。

7. The RTCP error calibration compensation method for five-axis laser processing equipment as claimed in claim 5, wherein in the step S5, the diameter D of the check rod is obtained and is based on the data X₁And X₂The following can be obtained: r ═ X₁-X₂-D)/2。

Technical Field

The invention relates to the field of five-axis laser processing equipment, in particular to an RTCP error calibration compensation method for five-axis laser processing equipment.

Background

The laser processing technology is an advanced manufacturing technology, and has high energy density, good collimation, and focusing light spots capable of reaching micron-scale precision. Therefore, a special laser processing head is used for replacing a cutter in the traditional mechanical processing, and the characteristic of high energy of focused laser is utilized.

The five-axis laser processing equipment is a typical representative of combining a laser processing system with a traditional five-axis linkage machine tool, has the technical advantages of laser processing and five-axis interpolation, and can be regarded as replacing a traditional cutter by a laser beam. Has been widely applied in the high-end processing field at present.

Five-axis machining equipment consists of three linear shafts and two rotating shafts, and can be divided into the following three types based on the structural form of the rotating shafts of the equipment: a. the double-swing head structure is characterized in that two rotating shafts are integrated with a cutter to drive the cutter to rotate for processing; b. the tool is integrated on a swing shaft, one swing shaft drives the tool to rotate, and the other rotating shaft drives a workpiece to rotate; c. the double-turntable type is a type in which a workpiece is mounted on two rotary shafts and the workpiece is rotated during machining.

In a high-grade five-axis numerical control system, RTCP is an abbreviation of Rotated Tool Center Point, and is also commonly called as a Tool nose Point following function. In five-axis machining, when a tool tip point track and a posture between a tool and a workpiece are obtained, the workpiece generates rotary motion, so that additional motion of a tool tip point is generated at the same time. The RTCP function is mainly used on a double-pendulum head structure, compensation is carried out by utilizing a rotating central point of the pendulum head, and the central point of a cutter and the actual contact position of the cutter and the surface of a workpiece are kept unchanged. The RTCP function is a good technology which can bring benefits and create values for customers, the machine tool with the RTCP technology does not need to align a workpiece with the axis of a rotary table accurately by an operator, the workpiece is clamped conveniently, the machine tool automatically compensates offset, the auxiliary time is greatly reduced, and meanwhile, the machining precision is improved. Meanwhile, the post-processing is simple to manufacture, and only the coordinates and the vectors of the tool point need to be output.

In the field of machining, tools such as a contact type 'standard measuring rod + dial indicator' are generally adopted for RTCP error compensation measurement of five-axis linkage machining equipment to detect, the standard measuring rod is adopted to simulate a cutter to be installed on a main shaft, and the dial indicator is used for measuring errors to compensate when the cutter rotates at different angles. However, the five-axis laser processing equipment has a structural form which is greatly different from that of the traditional five-axis processing equipment, firstly, a main shaft does not exist, and secondly, a focused light beam is usually invisible (such as infrared light and ultraviolet light), so that a standard measuring rod similar to the external dimension of the focused light beam does not exist. In summary, the RTCP error compensation method of the conventional five-axis machining apparatus is not suitable for a five-axis laser machining apparatus, and cannot measure a corresponding vector value.

Disclosure of Invention

The invention provides a RTCP error calibration compensation method for five-axis laser processing equipment, which can conveniently and quickly measure the vector value required by RTCP, ensure that the laser equipment uses the RTCP function and improve the processing precision of five-axis linkage of the laser processing equipment.

In order to achieve these objects and other advantages and in accordance with the purpose of the invention, a RTCP error calibration compensation method for five-axis laser processing equipment is provided, which records coordinate values for calibration at different positions of each rotation axis, measures or calculates offset vectors and vector data of the rotation axis, writes the offset vectors and vector data into the RTCP, and associates the xyz axes of the machine tool with each other through a control system in the RTCP.

Further, the method comprises the following specific steps:

s1: correcting the B axis by taking the working table surface of the C axis as a reference, and determining the zero coordinates of the B axis by dotting test on a concentric circle by laser;

s2: installing a check rod to enable the axis of the check rod to coincide with the axis of the C-axis rotation, adjusting the check rod through a dial indicator on the Z axis to enable the check rod to be concentric with the C axis, acquiring three points of the excircle of the check rod and calculating the rotation center (X) of the C-axis turntable_C，Y_C)；

S3: measuring X-axis coordinate value X of B-axis center in YOZ plane_BAnd, moving the C-axis table to Y_CRespectively acquiring data X from the left and right sides of the equipment moving on the worktable₁And X₂Then, the Z-axis coordinate value Z is calculated_B；

S4: x coordinate X of revolution center based on C axis_CAnd B-axis rotation center at X-axis coordinate X_BCalculating the difference value delta X between the rotation center of the B axis and the optical axis;

s5: measuring the diameter D of the check rod while based on the data X₁And X₂Calculating the distance R from the rotation center of the B shaft to the end face of the air tap;

s6: the data measured and calculated in steps S1 to S5 are written in RTCP, and the XYZBC five axes of the machine tool are associated.

Further, the step S1 includes:

s11: taking the working table surface of the C axis as a reference, placing the test piece on the working table surface, and calibrating the zero point position of the B axis;

s12: if the test point deviates in the X direction, rotating the B axis for adjustment; if the test point deviates in the Y direction, adjusting by increasing or decreasing the gasket at the connection screw of the cutting head;

s13: performing concentric circle test by laser dotting after each adjustment in the step S12, and if the concentricity deviation value of the concentric circles is less than 0.01mm, determining the zero point of the B axis;

wherein, the working table surface is in a horizontal state.

Further, the test method in step S13 is as follows:

s131: burning a circular burning surface on the test piece at the height of 5cm away from the test piece and with the laser power of 500W;

s132: burning a circular burning point on the test piece at the position 1-5 mm away from the test piece and with the laser power of 100W;

s133: the concentricity of the circular burned surface and the circular burned point was compared.

Further, the step S2 includes:

s21: installing a test check rod into a preset reference hole for calibrating the center of the C shaft, so that the axis of the check rod is superposed with the axis of the C shaft rotation;

s22: placing a dial indicator on a Z axis, placing a head of the dial indicator on a side bus of the inspection rod, and striking the dial indicator along the Z axis to ensure that the indication number change in the Z axis movement process is less than 0.01mm, and indicating that the bus of the inspection rod is parallel to the Z axis movement straight line; placing the gauge outfit on a side bus of the inspection rod, rotating the C shaft for one circle, observing the numerical value change of the gauge outfit, and adjusting the position of the inspection rod until the numerical value change of the gauge is less than 0.01mm when the C shaft rotates for one circle, the inspection rod is concentric with the C shaft;

s23: move the check rod under the cutting head, go to catch three points on the excircle of check rod with the camera in proper order: (X)_cn、Y_cn)， (X₂、Y₂)，(X₃、Y₃) Calculating the center of the excircle, and taking the obtained excircle center coordinate as the coordinate of the C-axis rotation center in a machine tool coordinate system: (X)_C、Y_C)；

Further, the step S3 includes:

s31: adjusting the cutting head to zero coordinate, then slowly moving the Z axis, and recording the Z axis coordinate value Z of the center of the B axis when the cutting head touches the C axis worktable surface_B；

S32: moving the C-axis table to Y_CThen moving the workbench to the left side of the equipment, returning the B axis to the zero position coordinate, rotating the B axis by 90 degrees, and then slowly moving the X axis to enable the air nozzle of the cutting head to touch a side bus of the inspection rod to obtain data X₁(ii) a Then moving the workbench to the right side of the equipment, returning the B axis to zero position coordinates, rotating the B axis to minus 90 degrees, and then slowly moving the X axis to enable the air nozzle of the cutting head to touch a side bus of the inspection rod to obtain data X₂；

Based on data X₁And X₂Calculating the coordinate of the B-axis rotation center on the X-axis: x_B＝(X₁+X₂)/2。

Further, in step S4, the X coordinate X based on the center of rotation of the C axis_CAnd B-axis rotation center at X-axis coordinate X_BAnd calculating the difference value between the rotation center of the B axis and the optical axis: Δ X ═ X_B-X_C。

Further, in the step S5, the diameter D of the check rod is acquired while being based on the numberAccording to X₁And X₂The following can be obtained: r ═ X₁-X₂-D)/2。

Compared with the prior art, the method has the advantages that the offset vector and the vector data are measured and written into the RTCP, the association relation of the five shafts of the machine tool is established, the RTCP function of the laser equipment is ensured to be used, the machining precision of the five-shaft linkage of the laser machining equipment is improved, and the method has certain universality and can be used for reference of other laser machining equipment in various forms, such as laser etching, laser drilling, laser cleaning and the like.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a machine tool according to one embodiment of the present invention.

Fig. 2 is a machine tool vector diagram according to one embodiment of the present invention.

Fig. 3 is a vector exploded view of one embodiment I2 of the present invention.

Fig. 4 is a vector exploded view of one embodiment I3 of the present invention.

FIG. 5 is a test strip mounting diagram according to one embodiment of the present invention.

FIG. 6 is a concentricity testing chart according to one embodiment of the invention.

FIG. 7 is a view of a check rod installation in accordance with one embodiment of the present invention.

FIG. 8 is a graph showing the measurement of X and Y values in the YOZ plane at the center of the B-axis according to one embodiment of the present invention.

FIG. 9 is a first graph of measured data according to one embodiment of the present invention.

FIG. 10 is a second graph of measured data according to one embodiment of the present invention.

Detailed Description

The present invention is further described in detail below with reference to the attached drawings so that those skilled in the art can implement the invention by referring to the description text.

It will be understood that terms such as "having," "including," and "comprising," as used herein, do not preclude the presence or addition of one or more other elements or groups thereof.

The invention provides a RTCP error calibration compensation method for five-axis laser processing equipment, which is characterized in that machine tool equipment adopts a simple pendulum shaft and simple pendulum platform structure, as shown in figure 1, the RTCP error calibration compensation method comprises three linear shafts XYZ, a rotating shaft B and a rotating shaft C, wherein the rotating shaft B and the rotating shaft C respectively rotate around the axes of a Y shaft and a Z shaft.

At an initial position, a laser cutting head is equivalent to a machine tool cutter, the optical axis of laser is equivalent to the rotation center of a machine tool spindle, and a cutter bracket is equivalent to an air nozzle of the cutting head. It can be seen that if the B axis is used as the first rotation center, when the cutting head is vertically downward, the optical axis caused by machining error, assembly error, etc. and the rotation center of the B axis are not in the same YOZ plane, which results in a plurality of offset vectors generated when the B axis and the C axis in five axes generate a mixed motion, including:

the distance offset vectors I2 from the tool carrier to the center/intersection of rotation of the 1 st pivot axis, the reverse vector I1 of I2, the distance offset vectors I3 from the machine reference point to the center/intersection of rotation of the 2 nd pivot axis, the reverse vector I4 of I3, specifically, I2 and I3 are shown in fig. 2. It should be emphasized here that in the present invention, since the turret is an irreplaceable structure, resulting in the vector chain being closed, I1-I2 and I4-I3.

As shown in fig. 3, vector decomposition of I2 is performed, and with the optical axis as a reference point, a component Δ X of the I2 vector in the X direction, a component 0 in the Y direction, and a component R of I2 in the Z direction are obtained. It can be seen that I2 can be obtained by calculating Δ X and R.

Further, the C axis is moved to a position coincident with the optical axis, and the C axis is associated with the cutting head B axis.

Then, vector decomposition is performed on I3, wherein I₃The X-direction component of the vector is the coordinate X of the C-axis revolution center_C，I₃The Y-direction component of the vector is the coordinate Y of the C-axis rotation center_CThe component in the Z direction being Z_C. It can be seen that by calculating Y_CAnd Z_CI3 may be obtained.

And finally, inputting the related parameters into an RTCP system, thereby completing RTCP deviation compensation of the laser five-axis equipment.

Therefore, the offset vector and the vector data of the rotating shaft are calculated by recording the coordinate values of the rotating shaft calibrated at different positions in the five-shaft laser processing equipment, finally the offset vector and the vector data are correspondingly written into an RTCP system, and the control system in the RTCP establishes the association relation of the XYZBC five shafts of the machine tool, so that the RTCP function is realized.

The compensation method comprises the following specific steps:

s1: correcting the B axis by taking the working table surface of the C axis as a reference, and determining the zero coordinates of the B axis by dotting test on a concentric circle by laser, as shown in FIG. 5;

s11: taking the working table surface of the C axis as a reference, placing the test piece on the working table surface, and calibrating the zero point position of the B axis;

s12: if the test point deviates in the X direction, rotating the B axis for adjustment; if the test point deviates in the Y direction, adjusting by increasing or decreasing the gasket at the connection screw of the cutting head;

s13: performing concentric circle test by laser dotting after each adjustment in the step S12, and if the concentricity deviation value of the concentric circles is less than 0.01mm, determining the zero point of the B axis;

wherein, the working table surface is in a horizontal state.

Specifically, the test method in step S13 includes: as shown in fig. 6:

s131: burning a circular burning surface on the test piece at the height of 5cm away from the test piece and with the laser power of 500W;

s132: burning a circular burning point on the test piece at the position 1-5 mm away from the test piece and with the laser power of 100W;

s133: the concentricity of the circular burned surface and the circular burned point was compared.

S2: installing a check rod to enable the axis of the check rod to coincide with the axis of the C-axis rotation, adjusting the check rod through a dial indicator on the Z axis to enable the check rod to be concentric with the C axis, acquiring three points of the excircle of the check rod and calculating the rotation center (X) of the C-axis turntable_C，Y_C) As shown in fig. 7;

specifically, S21: installing a test check rod into a preset reference hole for calibrating the center of the C shaft, so that the axis of the check rod is superposed with the axis of the C shaft rotation;

s22: placing a dial indicator on a Z axis, placing a head of the dial indicator on a side bus of the inspection rod, and striking the dial indicator along the Z axis to ensure that the indication number change in the Z axis movement process is less than 0.01mm, and indicating that the bus of the inspection rod is parallel to the Z axis movement straight line; placing the gauge outfit on a side bus of the inspection rod, rotating the C shaft for one circle, observing the numerical value change of the gauge outfit, and adjusting the position of the inspection rod until the numerical value change of the gauge is less than 0.01mm when the C shaft rotates for one circle, the inspection rod is concentric with the C shaft;

s23: move the check rod under the cutting head, go to catch three points on the excircle of check rod with the camera in proper order: (X)_cn、Y_cn)， (X₂、Y₂)，(X₃、Y₃) Calculating the center of the excircle, and taking the obtained excircle center coordinate as the coordinate of the C-axis rotation center in a machine tool coordinate system: (X)_C、Y_C)。

S3: measuring X-axis coordinate value X of B-axis center in YOZ plane_BAnd, moving the C-axis table to Y_CRespectively acquiring data X from the left and right sides of the equipment moving on the worktable₁And X₂Then, the Z-axis coordinate value Z is calculated_BAs shown in fig. 8;

specifically, S31: measuring Z value, adjusting the cutting head to zero position coordinate, slowly moving Z axis, and recording Z axis coordinate value Z of B axis center when the cutting head touches C axis worktable surface_B；

S32: measurement of X value, working of C axisTable movement to Y_CThen moving the workbench to the left side of the equipment, returning the B axis to the zero position coordinate, rotating the B axis by 90 degrees, and then slowly moving the X axis to enable the air nozzle of the cutting head to touch a side bus of the inspection rod to obtain data X₁(ii) a Then moving the workbench to the right side of the equipment, returning the B axis to zero position coordinates, rotating the B axis to minus 90 degrees, and then slowly moving the X axis to enable the air nozzle of the cutting head to touch a side bus of the inspection rod to obtain data X₂；

Based on data X₁And X₂Calculating the coordinate of the B-axis rotation center on the X-axis: x_B＝(X₁+X₂)/2。

S4: x coordinate X of revolution center based on C axis_CAnd B-axis rotation center at X-axis coordinate X_BCalculating the difference value delta X between the rotation center of the B axis and the optical axis;

specifically, an X coordinate X based on the center of rotation of the C-axis_CAnd B-axis rotation center at X-axis coordinate X_BAnd calculating the difference value between the rotation center of the B axis and the optical axis: Δ X ═ X_B-X_C。

S5: measuring the diameter D of the check rod while based on the data X₁And X₂Calculating the distance R from the rotation center of the B shaft to the end face of the air tap;

specifically, by obtaining the diameter D of the check rod and simultaneously based on the data X₁And X₂The following can be obtained: r ═ X₁-X₂-D)/2。

S6: the data measured and calculated in steps S1 to S5 are written in RTCP, and the xyz axes of the machine tool are associated as shown in fig. 9 and 10.

While embodiments of the invention have been disclosed above, it is not limited to the applications listed in the description and the embodiments. It can be applied to all kinds of fields suitable for the present invention. Additional modifications will readily occur to those skilled in the art. It is therefore intended that the invention not be limited to the exact details and illustrations described and illustrated herein, but fall within the scope of the appended claims and equivalents thereof.