TWI398622B - The Device and Method of Detecting Angle Error by Laser Interferometer - Google Patents

Description

Device and method for detecting angular error by laser interferometer

The invention relates to a device and a method for detecting an angular error of a laser interferometer, in particular to a laser interferometer receiving a reflected reflected beam through the receiver, and respectively obtaining two sets of displacement amounts, and the two sets of displacements are reused by the triangle. The function and method of obtaining the error signal by the distance of the corners.

One of the contributions of Taiwan's economic development relies on the high quality and high stability of its products. To maintain such a high standard, everyone has long been concentrating on using the latest and best equipment, or setting a stricter control system, but ignoring it. To maintain a high level, you must first have accurate measurements. Industrial angle measuring instruments have been positioned in the "preliminary setting before the machine or operation", but with the advancement of operating technology and the introduction of various types of machines, the products are more and more diversified, and the accuracy of the instruments is also It is getting higher and higher, and its use is becoming more and more extensive, and its importance relative to its industrial value is also becoming more and more important.

At present, in the industry, when processing or measuring products, the products need to be placed on the platform, but when the platform moves, the angle error will be generated, but when the product accuracy is not large, the angle error of the platform can be ignored. However, the current products are getting smaller and smaller, and the accuracy of the product size is getting higher and higher. The error of the platform can not be ignored. Especially the technology of precision machining and precision measurement is gradually emerging, and the precision requirement is nanometer. Level, it is now necessary to take into account the error of the platform, in order to effectively improve the overall quality and yield of the product.

Precision instruments for measuring angular errors include HP Laser Interferometer, Renishaw Laser Interferometer, SIOS Laser Interferometer and Automatic Sight.

HP laser interferometer and Renishaw laser interferometer are more common, mainly using angle mirror and angle beam splitter for measurement; the principle of measurement is to shoot the laser into the angle beam splitter, the angle beam splitter will split the light into two The road light is then injected into the angle mirror consisting of two corners. When the laser light enters the angle mirror, it will generate reflected light parallel to the incident light and enter the angle beam splitter. The interference beam is received by the sensor. When there is an angular error, the difference between the two corners can be measured, and then the trigonometric function is used to calculate the angle. The disadvantage is that it is expensive.

The SIOS laser interferometer angle measurement principle is that the SIOS laser interferometer is vertically injected into the plane mirror, and is injected into the sensor of the SIOS laser interferometer according to the original optical path, and is calculated and calculated when there is an angular error; For short-stroke measurements only, if the measured distance is too long, it will not be measured due to the angle problem.

The principle of measuring the automatic collimator is that the parallel collimator directly shoots the mirror directly into the mirror, and shoots the auto collimator according to the original optical path to measure the angle value. Although the automatic collimator has a high resolution for the angle of rotation, it is not suitable for on-line measurement on the implement.

In view of the shortcomings derived from the above-mentioned measuring angle error instrument, the inventor of the present invention has improved and innovated, and after years of painstaking research, he finally succeeded in researching and developing the device and method for detecting the angular error of the laser interferometer.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical non-contact detection mode for achieving a high accuracy requirement for a laser interferometer to detect angular errors.

A second object of the present invention is to provide an apparatus for detecting an angular error of an optical instrument with high resolution without being disturbed by a magnetic field.

Another object of the present invention is to provide a device that can be utilized in various workplaces and has a low-cost, high-accuracy, small-volume, easy-to-carry, easy to set up, and fast detection characteristics.

The apparatus and method for detecting an angular error of a laser interferometer capable of achieving the above object includes: a laser interferometer for receiving and outputting a first beam and a second beam, wherein the signal receiver can be a built-in type and An additional type; a corner 隅稜鏡 is disposed on the moving end of the mobile platform for receiving and transmitting the light beam to the mirror, and receiving the reflected light beam returned from the mirror, and then transmitting to the Laser interferometer; a mirror used to reflect the beam of a laser interferometer.

Referring to FIG. 1 , the apparatus and method for detecting an angular error of a laser interferometer provided by the present invention mainly include: a laser interferometer, at least two corners 21, 22, and at least two mirrors 31, 32. The laser interferometer 1 is configured to receive and output a first light beam 11 and a second light beam 12; the present invention utilizes light waves of two or more light sources having the same characteristics inside the laser interferometer 1 A measurement function is achieved; in the embodiment, a dual beam readhead inside the laser interferometer 1 is used to receive and output a first beam 11 and a second beam 12; the corners 21, 22 are arranged in The first beam 11 and the second beam 12 are on the transmission path of the moving platform 41 for receiving and transmitting the beam to the mirrors 31, 32, and the reflected beam received from the mirrors 31, 32. A is further reflected by the corners 21, 22 into a reflected beam B to the laser interferometer 1; the corners 21, 22 are characterized by a beam incident from the corners 21, 22 and a slave angle The beams reflected by 隅稜鏡21,22 are parallel, and the same is true when there are angle problems, so the angle can be overcome. The problem of degree change.

The mirrors 31, 32 are disposed between the laser interferometer 1 and the corners 21, 22, and the mirrors 31, 32 are configured to reflect the reflected beam A vertically back to the corners 21, 22 The corners 21, 22 are each reflected to generate a light beam to the mirrors 31, 32, and the reflected beams A are reflected to the corners 21, 22 via the mirrors 31, 32.稜鏡21,22 is used to return the reflected beam B to the laser interferometer 1 when the mobile terminal 41 generates an error, so that the laser interferometer 1 measures the error signal.

Where the mobile terminal 41 moves a small distance, the corner 隅稜鏡 The reflected beam A between the 21, 22 and the mirrors 31, 32 changes, and is synchronized such that the dimples 21, 22 each produce a reflected beam B, which is transmitted via the laser interferometer 1 After the receiver receives, and obtains two sets of displacements respectively, the two sets of displacements are subtracted, and the relative displacement can be obtained. Then, the angles of the angles 21 and 22 are calculated by the trigonometric function, and the angular error can be obtained. signal.

The measurement of the skewness error architecture is shown in Fig. 1 and Fig. 2. The read head of the laser interferometer 1 injects the dual light sources into the two corners 21, 22, respectively, by the two corners 21, 22 The reflected two beams are incident on the mirrors 31, 32. Since the incident light is perpendicular to the mirror surface of the mirrors 31, 32, the reflected beam B is reflected back to the receiver of the laser interferometer 1, so that the laser interferometer 1 The reading head can obtain two sets of displacements respectively, and the displacement amount can be subtracted to obtain the relative displacement amount, and then the distance between the angles , 21, 22 and the trigonometric function can be calculated to obtain the yaw degree error (Yaw Error).

The measurement of the pitch error structure is shown in Figure 3 and Figure 4. The read head of the laser interferometer 1 injects the dual light sources into the two corners 21, 22, which are reflected by the two corners 21, 22. Two beams of light are incident on the mirrors 31, 32. Since the incident light is perpendicular to the mirror surface of the mirrors 31, 32, the reflected beam B is reflected back to the receiver of the laser, so that the read head of the laser interferometer 1 can The two sets of displacements are obtained separately, and the displacement is subtracted to obtain the relative displacement. Then, the distance between the angles 21 and 22 and the trigonometric function are calculated to obtain the pitch error.

As shown in Fig. 5 and Fig. 6, the solid line is the original angle, and the broken line is the beam after rotating an angle. It can be known that the first beam 11 incident on the corners 21, 22 when there is an angular change And a second beam 12 is parallel to the beams reflected from the corners 21, 22; when the corners 21, 22 are rotated by θ, the light is rotated by 2 θ.

The calculation of the angle measurement principle is as shown in Figure 7 and Figure 8. The angle α of the corners 21, 22 and the first laser read head can read the beam length of L1, and the second laser read head can When the beam length of L2 is read, x can be obtained by the equation (1-1), and the displacement amount of the angle can be obtained by a trigonometric function: x = (L1 - L2) / 2 (1-1)

α =tan ^-1 [ x / d ] (1-2)

d is the distance between the center points of the two corners 21, 22.

A method for detecting an angular error of a laser interferometer 1 according to the present invention, wherein a first beam 11 and a second beam 12 emitted by the laser interferometer 1 are transmitted through the mirror 31, 32 to the corner 21 22, causing the corners 21, 22 to reflect a respective beam to the mirrors 31, 32, and then reflecting the reflected beams A to the corners 21, 22 via the mirrors 31, 32, and returning The reflected beam A is reflected by the corners 21, 22 into two reflected beams B to the laser interferometer 1, and the laser interferometer 1 respectively obtains two sets of displacements, and the two sets of displacements are subtracted, The relative displacement can be obtained, and then the distance between the corners 21, 22 and the trigonometric function can be used to obtain the error signal.

The above detailed description is specific to one of the possible embodiments of the present invention. It is to be understood that the scope of the invention is not limited to the scope of the invention, and the equivalents of the invention are intended to be included in the scope of the invention.

In summary, this case is not only innovative in terms of space type, but also can enhance the above-mentioned multiple functions compared with the customary items. It should fully comply with the statutory invention patent requirements of novelty and progressiveness, and apply for it according to law. This invention patent application, in order to invent invention, to the sense of virtue.

1‧‧‧Laser Interferometer

11‧‧‧First beam

12‧‧‧second beam

21,22‧‧‧Corner

31,32‧‧‧Mirror

4‧‧‧Mobile platform

41‧‧‧Mobile

A‧‧·reflected beam

B‧‧·reflected beam

1 is a perspective view of the deflection angle architecture of the laser interferometer according to the present invention; FIG. 2 is a top view of the deflection interferometer of the laser interferometer; FIG. 3 is a top view of the laser interferometer measuring the pitch angle Figure 4 is a top view of the laser interferometer measuring the pitch angle; Figure 5 is the angle of the counterclockwise rotation, the solid line is the original angle, and the dotted line is the schematic diagram of the optical path after rotating an angle; Sixth, the corner is rotated clockwise, the solid line is the original angle, the broken line is the schematic diagram of the optical path after rotating an angle; FIG. 7 is a schematic diagram of the optical path of the present invention; FIG. 8 is the angle measurement of the laser interferometer Schematic diagram of the principle.

1. . . Laser interferometer

11. . . First beam

12. . . Second beam

21,22. . . Horn

31,32. . . Reflector

Claims (11)

A device for detecting an angular error by a laser interferometer includes: a laser interferometer for receiving and outputting a first beam and a second beam, wherein the signal receiver can be a built-in type and an external type; Is disposed on the transmission path of the light beam, the angle 隅稜鏡 is used to receive and transmit the reflected light beam to the mirror; and the mirror is disposed between the laser interferometer and the corner , for reflection a reflected beam of the corner; whereby the corner is used to transmit the reflected beam to the mirror, and the reflected beam is incident on the corner and the laser interferometer via the mirror, and the The laser interferometer is adapted to convert the reflected beam into two sets of displacements, and subtract the displacement amount thereof to obtain a relative displacement amount, and then calculate the angle by the distance of the corner 与 and the trigonometric function to obtain the angle. Error signal. The apparatus for detecting an angular error of a laser interferometer according to claim 1 , wherein the error signal is a Yaw error. The apparatus for detecting an angular error of a laser interferometer according to claim 1 , wherein the error signal is a pitch error. The apparatus for detecting an angular error of a laser interferometer according to claim 1 , wherein the laser interferometer receives the reflected beam reflected by the corner horn through the receiver, and obtains two sets of displacement amounts respectively. By subtracting the displacement, the relative displacement can be obtained, and then the angle error signal can be obtained by calculating the distance between the corner and the trigonometric function. The apparatus for detecting an angular error of a laser interferometer according to claim 4 , wherein the error signal is a skewness error. The apparatus for detecting an angular error of a laser interferometer according to claim 4 , wherein the error signal is a pitch error. A method for detecting an angular error by a laser interferometer, wherein the beam emitted by the laser interferometer is transmitted through the mirror to reach the corner, so that the corner reflections respectively generate a beam to the reflection a mirror, and then reflecting each reflected beam to the corner via the mirror, and the returned reflected beam is converted into a reflected beam by the corner reflection to the laser interferometer, and the laser interferometer obtains two respectively The group displacement, the two groups of displacements are subtracted, the relative displacement can be obtained, and then the distance of the angle 与 and the trigonometric function are calculated to obtain the error signal. A device for detecting an angular error by a laser interferometer includes: a laser interferometer for receiving and outputting a first beam and a second beam, wherein the signal receiver can be a built-in type and an external type; Disposed on the mobile end of the mobile platform for receiving and transmitting the light beam to the mirror, and receiving the reflected light beam returned from the mirror and converting the reflected light beam into the reflected light beam to the laser interferometer through the corner reflection; a mirror disposed between the laser interferometer and the corner, for reflecting a reflected beam of the angle ;; Thereby, the mirror is configured to reflect the reflected beam back to the corner 隅稜鏡, and the reflected beam is incident on the laser interferometer by the corner ,, so that the laser interferometer measures the error signal. The apparatus for detecting an angular error of a laser interferometer according to claim 8 , wherein the moving end moves a small distance, so that a reflected beam between the corner and the mirror changes, and Synchronization causes the dichroic to generate a reflected beam, and the reflected beam is received by the receiver of the laser interferometer, and then the first displacement amount and the second displacement amount and the two sets of displacements are respectively subtracted An error signal. The apparatus for detecting an angular error of a laser interferometer according to claim 9 , wherein the laser interferometer receives the reflected beam reflected by the corner horn through the receiver, and obtains two sets of displacement amounts respectively. By subtracting the two sets of displacements, the relative displacement can be obtained, and then the distance between the corners and the trigonometric function can be calculated to obtain the error signal. The apparatus for detecting an angular error of a laser interferometer according to claim 8 , wherein the first beam and the second beam emitted by the laser interferometer reach the corner, so that the corner reflection Each generating a reflected beam to the mirror, and then reflecting each reflected beam to the corner via the mirror, and the returned reflected beam is reflected to the laser interferometer through the corner, and the laser interferes with The instrument obtains two sets of displacements respectively, and subtracts the two sets of displacements to obtain the relative displacement. Then, the distance between the angles and the trigonometric function is calculated to obtain the error signal.