CN110666592B - Receiving-transmitting split five-degree-of-freedom measuring device and method with optical path drift compensation - Google Patents

Abstract

The invention discloses a transceiver split type five-degree-of-freedom measuring device and method with optical path drift compensation. The measuring device comprises a laser emitting end composed of a laser, a first prism reflector, a first beam splitter, a second beam splitter, a second prism reflector, a fourth beam splitter, a second convex lens, a second two-dimensional position sensitive detector, a third convex lens and a third two-dimensional position sensitive detector; and a laser receiving end composed of a third beam splitter, a first four-quadrant detector, a first convex lens, a first two-dimensional position sensitive detector and a second four-quadrant detector. When the measuring device is used, the laser emitting end is installed at a fixed position of a CNC machine tool axis to be measured, and the laser receiving end is installed on a slide table of the CNC machine tool axis to be measured. The invention can realize simultaneous measurement of pitch angle, yaw angle, roll angle, horizontal straightness and vertical straightness, and realize long-distance measurement. It can eliminate the influence of laser angle drift on five-degree-of-freedom measurement, and improve measurement accuracy.

Description

Transmitter-receiver split five-degree-of-freedom measurement device and method with optical path drift compensation

Technical Field

The present invention belongs to the field of precision measurement technology and optical engineering, and in particular to a transceiver split-type five-degree-of-freedom measurement device and method with optical path drift compensation.

Background Art

The machining accuracy of CNC machine tools is one of the main indicators to measure the performance of machine tools, which directly affects the quality of parts. With the continuous improvement of the requirements for part accuracy in the machinery manufacturing industry, "how to improve the machining accuracy of CNC machine tools" has received widespread attention from experts and scholars from various countries. The error measurement and compensation method is an economical and effective method to reduce machine tool errors by measuring the original errors of the machine tools and using the spatial error model to solve the error compensation value. Common three-axis CNC machine tools have 21 geometric errors, namely the six-degree-of-freedom errors corresponding to each axis and the orthogonal error between every two axes. The six-degree-of-freedom errors include positioning errors, two-dimensional straightness errors, pitch angles, yaw angles, and roll angles. The rapid and effective measurement of machine tool errors is the key to improving the machining accuracy of CNC machine tools.

The static calibration system of machine tool errors is relatively mature, but the dynamic measurement and traceability of machine tool errors are still industrial problems that need to be solved urgently in the world today. At present, there are some mature static measurement instruments for machine tool errors on the market. For example, laser interferometer is a common instrument for measuring geometric errors of CNC machine tools. It is based on the principle of laser interference, but it can only measure one degree of freedom each time. The installation and adjustment process is complicated, the measurement cycle is long, and it cannot be integrated into CNC machine tools due to high cost and large size. It can only be used for offline measurement and calibration of machine tool errors; the XM-60 multi-beam laser interferometer produced by Renishaw in the UK can measure six degrees of freedom errors along the linear axis at the same time, but it is difficult to integrate into CNC machine tools due to its high cost; the laser Doppler displacement measuring instrument of Photodynamic Company in the United States measures four diagonals through the step-by-step body diagonal measurement method, and identifies the three positioning errors, six straightness errors and three verticality errors of the three axes of the machine tool. It is also difficult to integrate into CNC machine tools due to its high cost and complicated measurement and installation process. Many domestic universities have studied multi-DOF measurement as an important topic in the field of measurement, but most of them are still in the laboratory stage. The literature "Research on the simultaneous measurement method and system of six-DOF geometric motion error of linear guide laser" (Cui Cunxing, doctoral dissertation, Beijing Jiaotong University, 2016) realizes six-DOF measurement based on the combination of laser interference and laser collimation, and uses the common path light drift measurement and compensation principle to improve the measurement accuracy; the literature "Lowcost, compact 4-DOF measurement system with active compensation of beamangular drift error" (Y. Huang, K. C. Fan, W. Sun, S. Liu. Opt. Express vol. 26, pp. 17185, 2018.) realizes four-DOF measurement based on the principle of laser collimation and self-collimation, and measures the laser angle drift for compensation. The measurement device that can realize multi-DOF measurement and can be integrated into CNC machine tools is crucial for the dynamic measurement of machine tool errors, and further research is needed.

The multi-degree-of-freedom measurement based on the principle of laser collimation and autocollimation is a method with simple structure, easy integration and low cost. The laser of this method is installed at the fixed end to emit laser, and the position of the laser does not change during measurement. According to the installation position of the position detector, the multi-degree-of-freedom measurement structure can be divided into two types. One structure is to install reflective elements such as corner cube prisms and plane mirrors on the object to be measured, and use the reflection characteristics of elements such as corner cube prisms and plane mirrors to reflect the laser emitted by the laser back to the fixed end, and install a position detector at the fixed end to receive the laser. This structure is called an integrated transmitter and receiver; the other structure is to install the position detector directly on the object to be measured to directly receive the emitted laser. This structure is called a split transmitter and receiver. The optical path of the integrated transmitter and receiver measurement structure is half of the optical path of the integrated transmitter and receiver, which is conducive to long-distance measurement. Most machine tools come with grating rulers with an accuracy of about 1 to 2μm, so measuring the five-degree-of-freedom error of a single axis of a machine tool except for the positioning error can meet the dynamic measurement requirements of machine tool errors. When using the laser collimation characteristics for measurement, the angle drift of the laser seriously interferes with the measurement accuracy. Measuring and compensating the laser angle drift can effectively improve the error measurement accuracy. For large machine tools with long strokes, a five-degree-of-freedom measurement device that can compensate for laser angle drift, is suitable for long-distance measurement, is easy to integrate in CNC machine tools, and is low-cost is needed to achieve high-precision, long-distance, and online multi-degree-of-freedom measurement.

Summary of the invention

The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a five-degree-of-freedom measurement device and method with a separate transmitter and receiver with optical path drift compensation.

The objective of the present invention is achieved through the following technical solutions:

A transceiver split five-degree-of-freedom measuring device with optical path drift compensation, comprising a laser, a first prism reflector, a first beam splitter, a second beam splitter, a third beam splitter, a first four-quadrant detector, a first convex lens, a first two-dimensional position sensitive detector, a second prism reflector, a fourth beam splitter, a second four-quadrant detector, a second convex lens, a second two-dimensional position sensitive detector, a third convex lens and a third two-dimensional position sensitive detector;

The laser, the first prism reflector, the first beam splitter, the second beam splitter, the second prism reflector, the fourth beam splitter, the second convex lens, the second two-dimensional position sensitive detector, the third convex lens and the third two-dimensional position sensitive detector constitute a laser emitting end;

The third beam splitter, the first four-quadrant detector, the first convex lens, the first two-dimensional position sensitive detector and the second four-quadrant detector constitute a laser receiving end; when the measuring device is used, the laser emitting end is installed at a fixed position of the axis to be measured of the CNC machine tool, and the laser receiving end is installed on the slide table of the axis to be measured of the CNC machine tool;

The laser emits a laser, which is reflected by the first prism reflector and then split into two laser beams after passing through the first beam splitter. The laser beam passing through the first beam splitter is split into two laser beams after passing through the second beam splitter. The laser beam passing through the second beam splitter is split into two laser beams after passing through the third beam splitter. The laser beam passing through the third beam splitter is irradiated onto the first four-quadrant detector to achieve the measurement of horizontal straightness and vertical straightness, and is used as the two-dimensional straightness measurement result of the measuring device. The laser beam reflected by the third beam splitter is focused on the first two-dimensional position sensitive detector through the first convex lens to achieve the measurement of the pitch angle and the yaw angle. The laser beam reflected by the second beam splitter is focused on the second two-dimensional position sensitive detector through the second convex lens. The laser beam reflected by the first beam splitter is reflected by the second prism reflector, and the laser beam reflected by the second prism reflector is divided into two laser beams after passing through the fourth beam splitter. The laser beam after passing through the fourth beam splitter is irradiated onto the second four-quadrant detector to realize the measurement of horizontal straightness and vertical straightness. The measuring device only uses the vertical straightness of the second four-quadrant detector, and combines the vertical straightness of the first four-quadrant detector to realize the roll angle measurement; the laser beam reflected by the fourth beam splitter is focused on the third two-dimensional position sensitive detector through the third convex lens to realize the measurement of laser angle drift through the fourth beam splitter.

Another technical solution provided by the present invention is as follows: a five-degree-of-freedom measurement method with a split transmitter and receiver, which is used to achieve five-degree-of-freedom measurement of pitch angle, yaw angle, roll angle, horizontal straightness and vertical straightness, specifically comprising the following steps:

a. To achieve the pitch angle and yaw angle measurement, when there is a pitch angle ε _x at the laser receiving end, the light spot on the first two-dimensional position sensitive detector moves Δy ₈ along the y-axis direction. The focal length of the first convex lens is f ₇ , and the pitch angle ε _x is expressed by formula (1):

When there is a deflection angle _εy at the laser receiving end, the light spot on the first two-dimensional position sensitive detector moves Δz ₈ along the z-axis direction. The focal length of the first convex lens is f ₇ , and the deflection angle _εy is expressed by formula (2):

b. To achieve horizontal straightness and vertical straightness measurement, when there is horizontal straightness δ _x at the laser receiving end, the light spot on the first four-quadrant detector moves Δx ₆ along the x-axis direction. The horizontal straightness δ _x is expressed by formula (3):

δ _x = -Δx ₆ (3)

When there is a vertical straightness _δy at the first four-quadrant detector at the laser receiving end, the light spot on the first four-quadrant detector moves Δy ₆ along the y-axis direction, and the horizontal straightness _δy is expressed by formula (4):

δ _y = -Δy ₆ (4)

c. To measure the roll angle, when the vertical straightness _δy and the roll angle _εz exist at the first four-quadrant detector at the laser receiving end, the light spot on the second four-quadrant detector moves Δy ₁₁ along the y-axis direction. The roll angle _εz is expressed by formula (5):

Another technical solution provided by the present invention is as follows: a method for measuring and compensating for optical path angle drift, when the laser passing through the second beam splitter drifts, it affects the pitch angle, yaw angle, horizontal straightness, vertical straightness, and roll angle measurement; when the laser passing through the second beam splitter drifts, it affects the vertical straightness measurement at the second four-quadrant detector, thereby affecting the roll angle measurement; specifically, it is divided into the following steps:

a. When the laser passing through the second beam splitter has an angle drift of θ _y4 on the y-axis, the light spot on the second two-dimensional position sensitive detector moves Δz ₁₃ along the z-axis. The focal length of the second convex lens is f ₁₂ . The laser angle drift θ _y4 is expressed by equation (6):

The compensated yaw angle ε _y ′ is expressed by equation (7):

When considering the effect of laser angle drift θ _y4 on horizontal straightness, it is assumed that the laser rotates around the center of the second beam splitter, and the effect of laser angle drift θ _y4 before the center of the second beam splitter on horizontal straightness is negligible. The distance from the center of the second beam splitter to the first four-quadrant detector is l, and the compensated horizontal straightness δ _x ′ is expressed by (8):

b. When the laser x-axis passing through the second beam splitter has an angle drift of θ _x4 , the light spot on the second two-dimensional position sensitive detector moves Δy ₁₃ along the y-axis. The focal length of the second convex lens is f ₁₂ . The laser angle drift θ _x4 is expressed by equation (9):

The compensated pitch angle ε _x ′ is expressed by equation (10):

When considering the influence of laser angle drift θ _x4 on vertical straightness, it is assumed that the laser rotates around the center of the second beam splitter, and the influence of laser angle drift θ _x4 before the center of the second beam splitter on vertical straightness is negligible. The distance from the center of the second beam splitter to the first four-quadrant detector is l, and the vertical straightness δ _y ′ after compensation is expressed by (11):

c. When the laser x-axis passing through the fourth beam splitter has an angle drift of θ _x10 , the light spot on the third two-dimensional position sensitive detector moves Δy ₁₅ along the y-axis. The focal length of the third convex lens is f ₁₄ . The laser angle drift θ _x10 is expressed by equation (12):

When the laser angle drift θ _x10 affects the vertical straightness at the second four-quadrant detector and then affects the roll angle, it is assumed that the laser rotates around the center of the fourth beam splitter, and the influence of the laser angle drift θ _x10 before the center of the fourth beam splitter on the vertical straightness is negligible. The distance from the center of the fourth beam splitter to the second four-quadrant detector is l, and the compensated roll angle ε _z ′ is expressed by formula (13):

Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

1. The present invention provides a five-degree-of-freedom measurement device with a separate transmitter and receiver with optical path drift compensation, which makes full use of mechanical space, has a compact structure, and a small size, and can be integrated into a CNC machine tool to achieve online measurement;

2. The present invention provides a five-degree-of-freedom measurement method with a transmitter and receiver, which can realize the simultaneous measurement of pitch angle, yaw angle, roll angle, horizontal straightness and vertical straightness. The split measurement structure is adopted to overcome the shortcomings of the integrated measurement structure, such as long optical path and susceptibility to air disturbance, and realize long-distance measurement.

3. The present invention provides a method for measuring and compensating for optical path angle drift. By measuring the optical path angle drift and deriving the measurement formula of the five degrees of freedom after compensation, the influence of laser angle drift on the five-degree-of-freedom measurement is eliminated, thereby improving the measurement accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is an overall structural diagram of a five-DOF measurement device with separate transmitter and receiver with optical path drift compensation.

FIG. 2 is a front view of the change in the position of the light spot on the first two-dimensional position sensitive detector when there is a pitch angle at the laser receiving end.

FIG3 is a side view of the change in the position of the light spot on the first two-dimensional position sensitive detector when there is a pitch angle at the laser receiving end.

FIG4 is a front view of the change in the position of the light spot on the first two-dimensional position sensitive detector when there is a deflection angle at the laser receiving end.

FIG5 is a side view of the change in the position of the light spot on the first two-dimensional position sensitive detector when there is a deflection angle at the laser receiving end.

FIG. 6 is a diagram showing the change in the position of the light spot on the first four-quadrant detector when there is horizontal straightness at the laser receiving end.

FIG. 7 is a diagram showing the change in the position of the light spot on the first four-quadrant detector when there is vertical straightness at the laser receiving end.

FIG8 is a diagram showing the change in the position of the light spots on the first four-quadrant detector and the second four-quadrant detector when there is a roll angle at the laser receiving end.

FIG. 9 is a diagram showing the optical path change when the laser y-axis of the laser emitting end passes through the second beam splitter and undergoes an angle drift.

FIG. 10 is a diagram showing the change in the position of the light spot on the second two-dimensional position sensitive detector when the laser x-axis of the laser emitting end passing through the second beam splitter undergoes an angular drift.

FIG. 11 is a diagram showing the change of the optical path of the laser beam passing through the second beam splitter 4 when the laser beam from the laser emission end passes through the second beam splitter and the angle drift occurs on the x-axis.

FIG12 is a diagram showing the change in the position of the light spot on the third two-dimensional position sensitive detector when the laser x-axis of the laser emitting end passing through the fourth beam splitter undergoes an angular drift.

FIG. 13 is a diagram showing the change in the optical path of the laser beam passing through the fourth beam splitter when the laser x-axis of the laser beam emitted from the laser emission end passes through the fourth beam splitter and an angle drift occurs.

In the figure: 1 is a laser, 2 is a first prism reflector, 3 is a first beam splitter, 4 is a second beam splitter, 5 is a third beam splitter, 6 is a first four-quadrant detector, 7 is a first convex lens, 8 is a first two-dimensional position-sensitive detector, 9 is a second prism reflector, 10 is a fourth beam splitter, 11 is a second four-quadrant detector, 12 is a second convex lens, 13 is a second two-dimensional position-sensitive detector, 14 is a third convex lens, 15 is a third two-dimensional position-sensitive detector, 16 is a laser emitting end, 17 is a laser receiving end, _f7 is a focal length of the first convex lens 7, _f12 is a focal length of the second convex lens 12, _f14 is a focal length of the first convex lens 14, _Δy8 is the movement amount of the light spot on the first two-dimensional position-sensitive detector 8 along the y-axis, _Δz8 is the movement amount of the light spot on the first two-dimensional position-sensitive detector 8 along the z-axis, _Δx6 is the movement amount of the light spot on the first four-quadrant detector 6 along the x-axis, Δy ₆ is the movement amount of the light spot on the first four-quadrant detector 6 along the y-axis, Δy ₁₁ is the movement amount of the light spot on the second four-quadrant detector 11 along the y-axis, Δz ₁₃ is the movement amount of the light spot on the second two-dimensional position-sensitive detector 13 along the z-axis, Δy ₁₃ is the movement amount of the light spot on the second two-dimensional position-sensitive detector 13 along the y-axis, Δy ₁₅ is the movement amount of the light spot on the third two-dimensional position-sensitive detector 15 along the y-axis, ε _x is the pitch angle, ε _y is the yaw angle, ε _z is the roll angle, δ _x is the horizontal straightness, δ _y is the vertical straightness, θ _y4 is the drift angle of the laser passing through the second beam splitter 4 along the y-axis, θ _x4 is the drift angle of the laser passing through the second beam splitter 4 along the x-axis, and θ _x10 is the drift angle of the laser passing through the fourth beam splitter 10 along the x-axis, d is the distance between the first four-quadrant detector 6 and the second four-quadrant detector 11, l is the distance from the center of the second beam splitter 4 to the first four-quadrant detector 6 and the distance from the center of the fourth beam splitter 10 to the second four-quadrant detector 11.

DETAILED DESCRIPTION

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

The embodiment of the present invention consists of the following parts:

Part 1: A five-DOF measurement device with separate transmitter and receiver with optical path drift compensation;

As shown in FIG1 , the transceiver split five-DOF measuring device with optical path drift compensation comprises a laser 1, a first prism reflector 2, a first beam splitter 3, a second beam splitter 4, a third beam splitter 5, a first four-quadrant detector 6, a first convex lens 7, a first two-dimensional position-sensitive detector 8, a second prism reflector 9, a fourth beam splitter 10, a second four-quadrant detector 11, a second convex lens 12, a second two-dimensional position-sensitive detector 13, a third convex lens 14, and a third two-dimensional position-sensitive detector 15; the laser 1, the first prism reflector 2, the first beam splitter 3, The second beam splitter 4, the second prism reflector 9, the fourth beam splitter 10, the second convex lens 12, the second two-dimensional position sensitive detector 13, the third convex lens 14, and the third two-dimensional position sensitive detector 15 constitute a laser emitting end 16; the third beam splitter 5, the first four-quadrant detector 6, the first convex lens 7, the first two-dimensional position sensitive detector 8, and the second four-quadrant detector 11 constitute a laser receiving end 17; when the measuring device is in use, the laser emitting end 16 is installed at a fixed position of the axis to be measured of the CNC machine tool, and the laser receiving end 17 is installed on the slide of the axis to be measured of the CNC machine tool.

The laser 1 emits a laser, which is reflected by the first prism reflector 2 and then split into two laser beams after passing through the first beam splitter 3. The laser beam passing through the first beam splitter 3 is split into two laser beams after passing through the second beam splitter 4. The laser beam passing through the second beam splitter 4 is split into two laser beams after passing through the third beam splitter 5. The laser beam passing through the third beam splitter 5 is irradiated onto the first four-quadrant detector 6 to achieve the measurement of horizontal straightness and vertical straightness, and is used as the two-dimensional straightness measurement result of the device; the laser beam reflected by the third beam splitter 5 is focused on the first two-dimensional position sensitive detector 8 through the first convex lens 7 to achieve the measurement of the pitch angle and the yaw angle; the laser beam reflected by the second beam splitter 4 is focused on the second two-dimensional position sensitive detector 8 through the second convex lens 12 13, to realize the laser angle drift measurement through the second beam splitter 4; the laser reflected by the first beam splitter 3 is reflected by the second prism reflector 9, and the laser reflected by the second prism reflector 9 is divided into two laser beams after passing through the fourth beam splitter 10, and the laser after passing through the fourth beam splitter 10 is irradiated onto the second four-quadrant detector 11 to realize the measurement of horizontal straightness and vertical straightness. The device only uses the vertical straightness of the second four-quadrant detector 11, and combines the vertical straightness of the first four-quadrant detector 6 to realize the roll angle measurement; the laser reflected by the fourth beam splitter 10 is focused on the third two-dimensional position sensitive detector 15 through the third convex lens 14, to realize the laser angle drift measurement through the fourth beam splitter 10;

The second part provides a five-degree-of-freedom measurement method with a separate transmitter and receiver for the measurement device structure of the first part;

The five-degree-of-freedom measurement includes the measurement of pitch angle, yaw angle, roll angle, horizontal straightness and vertical straightness, which is achieved in the following steps:

a. To achieve pitch angle and yaw angle measurement, when the laser receiving end 17 has a pitch angle ε _x , as shown in FIG2 and FIG3, the light spot on the first two-dimensional position sensitive detector 8 moves Δy ₈ along the y-axis direction, the focal length of the first convex lens 7 is f ₇ , and the pitch angle ε _x is expressed by formula (1):

When the laser receiving end 17 has a deflection angle _εy , as shown in FIG4 and FIG5, the light spot on the first two-dimensional position sensitive detector 8 moves Δz ₈ along the z-axis direction, the focal length of the first convex lens 7 is f ₇ , and the deflection angle _εy is expressed by formula (2):

b. To achieve horizontal straightness and vertical straightness measurement, when the laser receiving end 17 has horizontal straightness δ _x , as shown in FIG6 , the light spot on the first four-quadrant detector 6 moves Δx ₆ along the x-axis direction, and the horizontal straightness δ _x is expressed by formula (3):

δ _x = -Δx ₆ (3)

When there is a vertical straightness _δy at the first four-quadrant detector 6 of the laser receiving end 17, as shown in FIG7, the light spot on the first four-quadrant detector 6 moves Δy ₆ along the y-axis direction, and the horizontal straightness _δy is expressed by formula (4):

δ _y = -Δy ₆ (4)

c. To measure the roll angle, when the first quadrant detector 6 of the laser receiving end 17 has a vertical straightness _δy and a roll angle _εz , as shown in FIG8 , the light spot on the second quadrant detector 11 moves _Δy11 along the y-axis direction, and the roll angle _εz is expressed by formula (5):

The third part provides a method for measuring and compensating the optical path angle drift according to the measuring device structure of the first part;

When the laser passing through the second beam splitter 4 drifts, the pitch angle, yaw angle, horizontal straightness, vertical straightness, and roll angle measurements are affected; when the laser passing through the second beam splitter 10 drifts, the vertical straightness measurement at the second four-quadrant detector 11 is affected, and thus the roll angle measurement is affected; measuring the optical path angle drift and compensating for it is implemented in the following steps:

a. When the laser passing through the second beam splitter 4 has an angle drift of θ _y4 on the y-axis, as shown in FIG9 , the light spot on the second two-dimensional position sensitive detector 13 moves along the z-axis by Δz ₁₃ , the focal length of the second convex lens 12 is f ₁₂ , and the laser angle drift θ _y4 is expressed by equation (6):

The compensated yaw angle ε _y ′ is expressed by equation (7):

When considering the influence of laser angle drift θ _y4 on horizontal straightness, it is assumed that the laser rotates around the center of the second beam splitter 4, and the influence of laser angle drift θ _y4 before the center of the second beam splitter 4 on horizontal straightness is negligible. The distance from the center of the second beam splitter 4 to the first four-quadrant detector 6 is l, and the compensated horizontal straightness δ _x ′ is expressed by (8):

b. When the laser light passing through the second beam splitter 4 has an angle drift of θ _x4 along the x-axis, as shown in FIGS. 10 and 11 , the light spot on the second two-dimensional position sensitive detector 13 moves Δy ₁₃ along the y-axis. The focal length of the second convex lens 12 is f ₁₂ . The laser angle drift θ _x4 is expressed by equation (9):

The compensated pitch angle ε _x ′ is expressed by equation (10):

When considering the influence of the laser angle drift θ _x4 on the vertical straightness, it is assumed that the laser rotates around the center of the second beam splitter 4, and the influence of the laser angle drift θ _x4 before the center of the second beam splitter 4 on the vertical straightness is negligible. The distance from the center of the second beam splitter 4 to the first four-quadrant detector 6 is l, and the vertical straightness δ _y ′ after compensation is expressed by (11):

c. When the laser light passing through the fourth beam splitter 10 has an angle drift of θ _x10 along the x-axis, as shown in FIGS. 12 and 13 , the light spot on the third two-dimensional position sensitive detector 15 moves Δy ₁₅ along the y-axis. The focal length of the third convex lens 14 is f ₁₄ . The laser angle drift θ _x10 is expressed by equation (12):

When the laser angle drift θ _x10 affects the vertical straightness at the second four-quadrant detector 11 and further affects the roll angle, it is assumed that the laser rotates about the center of the fourth beam splitter 10, and the influence of the laser angle drift θ _x10 before the center of the fourth beam splitter 10 on the vertical straightness is negligible. The distance from the center of the fourth beam splitter 10 to the second four-quadrant detector 11 is l, and the compensated roll angle ε _z ′ is expressed by (13):

The present invention is not limited to the embodiments described above. The above description of the specific embodiments is intended to describe and illustrate the technical solution of the present invention. The above specific embodiments are merely illustrative and not restrictive. Without departing from the scope of the present invention and the scope of protection of the claims, a person of ordinary skill in the art can also make many forms of specific changes under the guidance of the present invention, which all fall within the scope of protection of the present invention.

Claims (3)

1. A transceiver split type five-degree-of-freedom measuring device with optical path drift compensation, characterized in that it comprises a laser (1), a first prism reflector (2), a first beam splitter (3), a second beam splitter (4), a third beam splitter (5), a first four-quadrant detector (6), a first convex lens (7), a first two-dimensional position sensitive detector (8), a second prism reflector (9), a fourth beam splitter (10), a second four-quadrant detector (11), a second convex lens (12), a second two-dimensional position sensitive detector (13), a third convex lens (14) and a third two-dimensional position sensitive detector (15); The laser (1), the first prism reflector (2), the first beam splitter (3), the second beam splitter (4), the second prism reflector (9), the fourth beam splitter (10), the second convex lens (12), the second two-dimensional position sensitive detector (13), the third convex lens (14) and the third two-dimensional position sensitive detector (15) constitute a laser emission end (16); The third beam splitter (5), the first four-quadrant detector (6), the first convex lens (7), the first two-dimensional position sensitive detector (8) and the second four-quadrant detector (11) constitute a laser receiving end (17); when the measuring device is used, the laser emitting end (16) is installed at a fixed position of the axis to be measured of the numerical control machine tool, and the laser receiving end (17) is installed on the slide table of the axis to be measured of the numerical control machine tool; The laser (1) emits a laser beam, which is reflected by a first prism reflector (2) and then split into two laser beams after passing through a first beam splitter (3). The laser beam that passes through the first beam splitter (3) is split into two laser beams after passing through a second beam splitter (4). The laser beam that passes through the second beam splitter (4) is split into two laser beams after passing through a third beam splitter (5). The laser beam that passes through the third beam splitter (5) is irradiated onto a first four-quadrant detector (6), thereby realizing the measurement of horizontal straightness and vertical straightness, and serving as a two-dimensional straightness measurement result of the measuring device. The laser light reflected by the third beam splitter (5) is focused on a first two-dimensional position sensitive detector (8) through a first convex lens (7), thereby achieving pitch angle and yaw angle measurement; The laser light reflected by the second beam splitter (4) is focused on a second two-dimensional position sensitive detector (13) through a second convex lens (12), thereby realizing the measurement of the laser light angle drift through the second beam splitter (4); The laser reflected by the first beam splitter (3) is reflected by the second prism reflector (9), and the laser reflected by the second prism reflector (9) is split into two laser beams after passing through the fourth beam splitter (10). The laser beam after passing through the fourth beam splitter (10) is irradiated onto the second four-quadrant detector (11) to achieve the measurement of horizontal straightness and vertical straightness. The measuring device only uses the vertical straightness of the second four-quadrant detector (11) and combines it with the vertical straightness of the first four-quadrant detector (6) to achieve the measurement of the roll angle. The laser light reflected by the fourth beam splitter (10) is focused on a third two-dimensional position sensitive detector (15) via a third convex lens (14), thereby realizing the measurement of the laser light angle drift through the fourth beam splitter (10). 2. A five-degree-of-freedom measurement method with a transmitter and receiver separated, based on the five-degree-of-freedom measurement device with a transmitter and receiver separated according to claim 1, characterized in that it is used to achieve five-degree-of-freedom measurement of pitch angle, yaw angle, roll angle, horizontal straightness and vertical straightness, and specifically comprises the following steps: a. To achieve pitch angle and yaw angle measurement, when the laser receiving end (17) has a pitch angle _εx , the light spot on the first two-dimensional position sensitive detector (8) moves Δy ₈ along the y-axis direction, the focal length of the first convex lens (7) is f ₇ , and the pitch angle _εx is expressed by formula (1): When the laser receiving end (17) has a deflection angle _εy , the light spot on the first two-dimensional position sensitive detector (8) moves _Δz8 along the z-axis direction. The focal length of the first convex lens (7) is _f7 , and the deflection angle _εy is expressed by formula (2): b. To achieve horizontal straightness and vertical straightness measurement, when the laser receiving end (17) has horizontal straightness δ _x , the light spot on the first four-quadrant detector (6) moves Δx ₆ along the x-axis direction. The horizontal straightness δ _x is expressed by formula (3): δ _x = -Δx ₆ (3) When the vertical straightness _δy exists at the first four-quadrant detector (6) of the laser receiving end (17), the light spot on the first four-quadrant detector (6) moves Δy ₆ along the y-axis direction, and the horizontal straightness _δy is expressed by formula (4): δ _y = -Δy ₆ (4) c. To achieve roll angle measurement, when the first four-quadrant detector (6) of the laser receiving end (17) has a vertical straightness _δy and a roll angle _εz , the light spot on the second four-quadrant detector (11) moves _Δy11 along the y-axis direction, and the roll angle _εz is expressed by formula (5): 3. A method for measuring and compensating for optical path angle drift, based on the transceiver split five-degree-of-freedom measuring device according to claim 1, characterized in that when the laser passing through the second beam splitter (4) drifts, it affects the pitch angle, yaw angle, horizontal straightness, vertical straightness, and roll angle measurement; when the laser passing through the fourth beam splitter (10) drifts, it affects the vertical straightness measurement at the second four-quadrant detector (11), thereby affecting the roll angle measurement; specifically, it is divided into the following steps: a. When the laser passing through the second beam splitter (4) has an angle drift of θ _y4 on the y-axis, the light spot on the second two-dimensional position sensitive detector (13) moves Δz ₁₃ along the z-axis. The focal length of the second convex lens (12) is f ₁₂ . The laser angle drift θ _y4 is expressed by equation (6): The compensated yaw angle ε _y ′ is expressed by equation (7): When considering the influence of the laser angle drift θ _y4 on the horizontal straightness, it is assumed that the laser rotates around the center of the second beam splitter (4), and the influence of the laser angle drift θ _y4 before the center of the second beam splitter (4) on the horizontal straightness is negligible. The distance from the center of the second beam splitter (4) to the first four-quadrant detector (6) is l, and the compensated horizontal straightness δ _x ′ is expressed by (8): b. When the laser light passing through the second beam splitter (4) has an angle drift of θ _x4 along the x-axis, the light spot on the second two-dimensional position sensitive detector (13) moves Δy ₁₃ along the y-axis. The focal length of the second convex lens (12) is f ₁₂ . The laser angle drift θ _x4 is expressed by equation (9): The compensated pitch angle ε _x ′ is expressed by equation (10): When considering the influence of the laser angle drift θ _x4 on the vertical straightness, it is assumed that the laser rotates around the center of the second beam splitter (4), and the influence of the laser angle drift θ _x4 before the center of the second beam splitter (4) on the vertical straightness is negligible. The distance from the center of the second beam splitter (4) to the first four-quadrant detector (6) is l, and the vertical straightness δ _y ′ after compensation is expressed by (11): c. When the laser light passing through the fourth beam splitter (10) has an angle drift of θ _x10 along the x-axis, the light spot on the third two-dimensional position sensitive detector (15) moves Δy ₁₅ along the y-axis. The focal length of the third convex lens (14) is f ₁₄ . The laser angle drift θ _x10 is expressed by equation (12): When the laser angle drift θ _x10 affects the vertical straightness at the second four-quadrant detector (11), and further affects the roll angle, it is assumed that the laser rotates around the center of the fourth beam splitter (10), and the influence of the laser angle drift θ _x10 before the center of the fourth beam splitter (10) on the vertical straightness is negligible. The distance from the center of the fourth beam splitter (10) to the second four-quadrant detector (11) is l, and the compensated roll angle ε _z ′ is expressed by formula (13):