CN101839697A - Optical system for use in shaft hole diameter measurement - Google Patents

Abstract

The invention discloses an optical system applied to shaft hole diameter measurement, which relates to the technical field of advanced optical design and precision measurement. The optical system includes: a photoelectric detection device, a reference device, a fixed adjustment device, an imaging device, and an illumination device; The photoelectric detection device, the fixed adjustment device, the imaging device, and the lighting device are placed symmetrically with respect to the reference device; the variation of the shaft hole diameter to be measured is not perpendicular to the optical axis of the imaging device; the The photoelectric detection device is fixed on the fixed adjustment device; the imaging device is fixed on the fixed adjustment device along the slope direction of the fixed adjustment device; the lighting device is fixed on the fixed adjustment device along the horizontal plane direction ; The fixed adjustment device is fixed on the reference device. The embodiment of the present invention realizes accurate imaging measurement of the geometric quantity to be measured that cannot be observed or imaged in the forward direction, and meets the requirements for measuring the diameter of the shaft hole.

Description

An Optical System Applied to Shaft Hole Diameter Measurement

technical field

The invention relates to the technical field of advanced optical design and precision measurement, in particular to an optical system applied to shaft hole diameter measurement.

Background technique

With the development of measurement technology, a variety of optical systems for inner diameter measurement have been proposed in the prior art, and the measurement can be realized through these optical systems, which initially meet the needs of practical applications.

In the process of realizing the present invention, the inventors found that the above-mentioned prior art has at least the following disadvantages and deficiencies: the measurement method in the prior art cannot perform accurate imaging measurement of the geometric quantity to be measured that cannot be observed or imaged in the forward direction.

Contents of the invention

In order to achieve accurate imaging measurement of geometric quantities to be measured that cannot be observed or imaged in the forward direction, and to meet the needs of inner diameter measurement in practical applications, the embodiment of the present invention applies the off-axis imaging technology to the field of measurement technology, providing a An optical system applied to shaft hole diameter measurement, the technical solution is as follows:

An embodiment of the present invention provides an optical system applied to shaft hole diameter measurement. The optical system includes: a geometric quantity to be measured (shaft hole diameter change or other geometric quantities that cannot be observed from the front), a photoelectric detection device, and a reference device , fixed adjustment device, imaging device, lighting device;

The geometric quantity to be measured, the photoelectric detection device, the fixed adjustment device, the imaging device, and the lighting device are placed symmetrically with respect to the reference device; the geometric quantity to be measured and the light of the imaging device The axis is not vertical; the photoelectric detection device is fixed on the fixed adjustment device; the imaging device is fixed on the fixed adjustment device along the slope direction of the fixed adjustment device; the lighting device is fixed on the fixed adjustment device along the horizontal direction on the fixed adjustment device; the fixed adjustment device is fixed on the reference device.

The plane of the geometric quantity to be measured is conjugate to the plane of the photoelectric detection device.

The imaging device and/or the illuminating device are placed with the optical surface facing downward.

The objective lens in the imaging device adopts 3 groups of 4 lenses.

The beneficial effects of the technical solution provided by the embodiments of the present invention are:

By making the optical axis of the imaging device not perpendicular to the geometric quantity to be measured, the off-axis imaging technology is applied to the shaft hole measurement, and the accurate imaging measurement of the geometric quantity to be measured that cannot be observed or imaged in the forward direction is realized. In practical applications, there is a need for shaft hole diameter measurement; and by adopting off-axis optical design, the problems of clear imaging of a certain part of the geometric quantity to be measured, unclear imaging of a certain part and low measurement accuracy are solved.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained according to these drawings without any creative effort.

Fig. 1 is a schematic structural diagram of an optical system provided by an embodiment of the present invention;

FIG. 2 is a schematic diagram of ray tracing of an optical system provided by an embodiment of the present invention.

In the accompanying drawings, the list of parts represented by each label is as follows:

1-1: geometric quantity to be measured; 1-2: photoelectric detection device; 1-3: reference device; 1-4 fixed adjustment device; 1-5: imaging device; 1-6: lighting device.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the implementation manner of the present invention will be further described in detail below in conjunction with the accompanying drawings.

In order to achieve accurate imaging measurement of geometric quantities to be measured that cannot be observed or imaged in the forward direction, and to meet the needs of measuring the diameter of the shaft hole in practical applications, the off-axis imaging technology is applied to the embodiment of the present invention, and the implementation of the present invention The example provides an optical system applied to shaft hole diameter measurement, see Fig. 1, the system mainly includes: geometric quantity to be measured 1-1, photoelectric detection device 1-2, reference device 1-3, fixed adjustment device 1- 4. Imaging devices 1-5, lighting devices 1-6;

The geometric quantity to be measured 1-1, the photoelectric detection device 1-2, the fixed adjustment device 1-4, the imaging device 1-5, and the lighting device 1-6 are symmetrically placed relative to the reference device 1-3; the geometric quantity to be measured 1-1 It is not perpendicular to the optical axis of the imaging device 1-5; the photoelectric detection device 1-2 is fixed on the fixed adjustment device 1-4; the imaging device 1-5 is fixed on the fixed adjustment device 1-4 along the slope direction of the fixed adjustment device 1-4 4; the lighting device 1-6 is fixed on the fixed adjustment device 1-4 along the horizontal plane direction, and keeps the beam level of the lighting device 1-6; the fixed adjustment device 1-4 is fixed on the reference device 1-3.

Among them, the geometric quantity to be measured mainly refers to the diameter change of the shaft hole or other geometric quantities that cannot be observed positively.

During specific implementation, the optical axis of the imaging device 1-5 is not perpendicular to the geometric quantity to be measured 1-1, so that there is a certain angle between the optical axis of the imaging device 1-5 and the geometric quantity to be measured 1-1, realizing For the application of the off-axis imaging technology, the degree of the included angle is related to the actual size of the geometric quantity to be measured, which is not limited in the embodiments of the present invention during specific implementation. The imaging device 1-5 is fixed on the fixed adjustment device 1-4 along the slope direction of the fixing device 1-4, and the slope direction is determined by the design parameters of the off-axis imaging objective lens, and the embodiment of the present invention does not limit it when it is implemented. .

The above-mentioned fixing and adjusting device 1-4 is used to fix the geometric quantity to be measured 1-1, the photoelectric detection device 1-2, the imaging device 1-5 and the lighting device 1-6, and the fixing method can be card slot fixing, bolt fixing or other The fixing method is not limited in this embodiment of the present invention during specific implementation.

To sum up, the application of off-axis imaging technology to shaft hole diameter measurement solves the problem that in practical applications, it is impossible to perform accurate imaging measurement on geometric quantities to be measured that cannot be observed or imaged in the forward direction.

Since the geometric quantity 1-1 to be measured is not perpendicular to the optical axis of the imaging device 1-5, the object distances of different parts of the geometric quantity 1-1 to be measured are relatively different from the imaging device 1-5. On the one hand, due to the depth of field The influence will make the imaging of a certain part of the geometric quantity 1-1 to be measured clear, and the imaging of a certain part is not clear; Perspective deformation, thereby affecting the measurement accuracy of the geometric quantity 1-1 to be measured.

In order to further solve the problem that the imaging of a certain part of the geometric quantity 1-1 to be measured is clear, the imaging of a certain part is not clear, and the problem of affecting the measurement accuracy, the embodiment of the present invention further adopts an off-axis optical design, as described below for details:

Through the design of the objective lens of the imaging device 1-5, the problem of clear imaging of a certain part of the geometric quantity 1-1 to be measured and unclear imaging of a certain part can be solved. In the embodiment of the present invention, the imaging device 1-5 is preferably The objective lens adopts 3 groups of 4 lenses, through which the magnification of the object image is obtained by 1 to 3 times, and the quality of imaging is improved. After the calibration method, the measurement accuracy of the geometric quantity to be measured can be further improved by 1-1. Specifically During implementation, lenses of other groups may also be used, which is not limited in this embodiment of the present invention. Referring to Fig. 2, Fig. 2 shows a schematic diagram of ray tracing obtained after the objective lens in the imaging device 1-5 adopts 3 groups of 4 lenses. From this figure, it can be known that the geometric quantity 1-1 to be measured is enlarged by 1 ~3 times, the imaging quality is improved, and it can be further known that the measurement accuracy of the geometric quantity to be measured is improved by the device.

To sum up, by adopting the above-mentioned off-axis optical design, the problem of clear imaging of a certain part of the geometric quantity to be measured and unclear imaging of a certain part is solved, and the measurement accuracy is further improved.

Furthermore, in order to solve the problem of measurement error caused by perspective deformation, the embodiment of the present invention preferably conjugates the plane of the tilted photodetection device 1-2 to the plane of the tilted geometric quantity to be measured 1-1, thereby correcting perspective distortion.

Further, in order to prevent the imaging device 1-5 and the lighting device 1-6 from being polluted by impurities in the external environment during use, such as debris, dust and other impurities, the embodiment of the present invention preferably combines the imaging device 1-5 and /or the lighting devices 1-6 are placed with the optical surface facing down.

Further, the photodetection device 1-2 can be devices such as CCD (Charge-coupled Device, charge-coupled device), PSD (Position Sensitive Device, position-sensitive device), and can also be other devices during specific implementation, and the present invention implements Examples are not limited to this.

Further, in order to meet various needs during actual measurement, in actual implementation, one or more groups of combinations may be used to simultaneously measure the geometric quantities 1-1 to be measured in multiple radial directions.

Further, in order to obtain a better measurement effect, the embodiment of the present invention preferably adopts a laser with pigtails, and places the laser externally. In actual implementation, it can also be other lasers, and this embodiment of the present invention does not do this limit.

During specific implementation, the photoelectric detection device 1-2 can be a photodetector; the reference device 1-3 can be a central reference column; the fixed adjustment device 1-4 can be an adjustment block; the imaging device 1-5 can be an optical detection lens; Devices 1-6 may be fiber collimators. During specific implementation, the foregoing apparatus may also be other corresponding devices, which is not limited in this embodiment of the present invention.

In the embodiment of the present invention, the main working mode of the optical system is described by taking the photodetector, the central reference column, the adjustment block, the optical detection lens, and the optical fiber collimator as examples, and the detailed description is as follows:

First, the photodetector, central reference column, adjustment block, optical detection lens, and fiber collimator are fixed according to the fixing method described above; secondly, the laser light emitted by the laser with pigtails is transmitted through the fiber and then collimated by the fiber collimator. After the output, the collimated laser light is irradiated on the geometric quantity to be measured, and reflection occurs, and the reflected light is imaged by the optical detection lens, and then imaged on the photodetector, which receives and outputs the photodetector; again, connect the output result to the actual In the applied circuit, the calculation is performed, and the actual measurement result is finally obtained, that is, the precise measurement of the geometric quantity to be measured can be realized through the above-mentioned method.

To sum up, the embodiment of the present invention provides an optical system applied to shaft hole diameter measurement. By applying the off-axis imaging technology to the shaft hole diameter measurement, the system solves the problem that the frontal observation or The problem of accurate imaging measurement of the geometric quantity to be measured by forward imaging; by adopting off-axis optical design, the problem of clear imaging of a certain part of the geometric quantity to be measured, unclear imaging of a certain part and low measurement accuracy are solved.

Those skilled in the art can understand that the accompanying drawing is only a schematic diagram of a preferred embodiment, and the serial numbers of the above-mentioned embodiments of the present invention are for description only, and do not represent the advantages and disadvantages of the embodiments.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within range.

Claims (4)

1. An optical system applied to shaft hole diameter measurement, characterized in that the optical system comprises: The geometric quantity to be measured, the photoelectric detection device, the reference device, the fixed adjustment device, the imaging device, and the lighting device; the geometric quantity to be measured, the photoelectric detection device, the fixed adjustment device, the imaging device, and the lighting device Placed symmetrically with respect to the reference device; the geometric quantity to be measured is not perpendicular to the optical axis of the imaging device; the photoelectric detection device is fixed on the fixed adjustment device; the imaging device is positioned along the fixed adjustment device The slope direction is fixed on the fixed adjustment device; the lighting device is fixed on the fixed adjustment device along the horizontal plane direction; the fixed adjustment device is fixed on the reference device. 2. The optical system according to claim 1, wherein the plane of the geometric quantity to be measured is conjugate to the plane of the photodetection device. 3 . The optical system according to claim 1 , wherein the imaging device and/or the illuminating device are placed with the optical surface facing downward. 4 . 4. The optical system according to claim 1 or 3, characterized in that, the objective lens in the imaging device adopts 3 groups of 4 lenses.

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