阅读说明：本技术 一种基于三角测量法的彩色三角位移传感器及其测量方法 (Color triangular displacement sensor based on triangulation method and measuring method thereof ) 是由 王前程 王国安 郑泽鹏 黄碧华 周飞 吴伟锋 孙久春 于 2019-12-23 设计创作，主要内容包括：本发明提供了一种基于三角测量法的彩色三角位移传感器及其测量方法,采用复色点光源为入射光线,实现了用像面能量最高点的位置来表征被测物体高度信息的方法,由于采用复色点光源代替现有技术中的激光点光源,因此彩色三角位移传感器可以具有更高的分辨率,同时利用圆孔对被测物体表面非聚焦波长的反射光线进行过滤,使得仅仅聚焦在被测物体表面上的特定波长的反射光线可以传输到线型探测器,从而使得彩色三角位移传感器具有更高的信噪比,因此本实施例所提供的彩色三角位移传感器及其测量方法,有效的提高了信噪比,可获取到更为准确的物体表面高度信息。(The invention provides a color triangle displacement sensor based on a triangulation method and a measuring method thereof, which adopt a polychromatic point light source as an incident light to realize a method for representing the height information of a measured object by using the position of the highest point of image surface energy, because the laser point light source in the prior art is replaced by the multicolor point light source, the color triangular displacement sensor can have higher resolution, meanwhile, the round hole is used for filtering the reflected light with non-focusing wavelength on the surface of the measured object, so that only the reflected light with specific wavelength focused on the surface of the measured object can be transmitted to the linear detector, therefore, the color triangle displacement sensor and the measuring method thereof provided by the embodiment effectively improve the signal-to-noise ratio and can acquire more accurate object surface height information.)

1. A color triangulation displacement sensor based on triangulation, comprising: the system comprises a multi-color point light source, a first dispersive lens group, a second dispersive lens group, a filter, a focusing lens group, a linear array detector and a processor;

the polychromatic point light source is used for emitting polychromatic light;

the first dispersive lens group is used for carrying out axial dispersion on the polychromatic light and focusing the dispersed light with different wavelengths on the surface of a measured object;

the second dispersive lens group is used for receiving the reflected light beam reflected by the surface of the measured object and projecting the reflected light beam to the optical filter;

the optical filter is positioned on the focal plane of the second dispersive lens group and used for receiving the reflected light beam transmitted by the second dispersive lens group and filtering out the reflected light beam with a specific wavelength range; wherein the specific wavelength range is the wavelength range of light focused on the surface of the object to be measured;

the focusing lens group is used for receiving the reflected light beam filtered by the optical filter and focusing the reflected light beam on the linear array detector;

the linear array detector is used for receiving a reflected light beam, acquiring position information of an image point of the reflected light beam and transmitting the acquired position information to the processor;

and the processor is used for obtaining the height information of the surface of the measured object according to the position information.

2. The triangulation-based color triangulation displacement sensor of claim 1 wherein the polychromatic point light source comprises: the white LED and the shaping lens group are used for shaping the white light emitted by the white LED.

3. The triangulation-based chromatic trigonometric displacement sensor of claim 1, wherein the first dispersive lens group and the second dispersive lens group are structurally symmetrical.

4. The triangulation-based color triangulation displacement sensor of claim 3 wherein the first or second dispersive lens group comprises at least one spherical lens.

5. The triangulation-based chromatic triangulation displacement sensor of any of the claims 1 to 4, characterized by the fact that the filter is a circular hole, which is placed in the focal plane of the second dispersive lens group, for filtering out the light of the non-focused wavelength reflected from the surface of the object to be measured.

6. The triangulation based color triangulation displacement sensor according to any of the claims 1 to 4, characterized in that the line detector is a line CCD or CMOS.

7. A measuring method of the color triangular displacement sensor according to claim 1, comprising:

the first dispersion lens group is used for carrying out dispersion on the polychromatic light, and the dispersed light rays with different wavelengths are focused on the surface of a measured object;

acquiring position information of a reflected light beam image point reflected by the surface of the measured object by using a linear array detector, and sending the position information to a processor;

and the processor obtains the height information of the measured object according to the position information.

8. The method of measurement according to claim 7, wherein the step of dispersing the polychromatic light is preceded by:

the white light LED is used for emitting white light, the white light is incident to the shaping lens group, and the white light is shaped by the shaping lens group and then emitted.

9. The measuring method according to claim 8, wherein before the step of obtaining the position information of the image point of the reflected light beam reflected by the surface of the measured object by using the linear array detector, the method further comprises:

receiving a reflected light beam reflected on the surface of a measured object by using a second dispersive lens group, emitting the reflected light beam to a filter, filtering the reflected light beam by using the filter, and filtering the reflected light beam with a specific wavelength range;

and focusing the filtered reflected light beam on a linear array detector.

10. The measurement method according to claim 9, wherein the filter is a circular hole, and the circular hole is provided on a focal plane of the second dispersive lens group.

Technical Field

The invention relates to the technical field of high-precision measurement, in particular to a color triangular displacement sensor based on a triangulation method and a measurement method thereof.

Background

With the development of industrial technology, the requirement of technicians on measurement accuracy is higher and higher, and the laser triangulation displacement method is widely applied to the measurement of physical quantities such as thickness and shape of an object as a high-accuracy nondestructive testing mode.

The laser triangular displacement method realizes the direct correspondence of the position of a signal wave crest on the linear array or area array photosensitive element and the height information of the surface of a measured object, the height information of the measured object is represented by extracting the position of the signal wave crest acquired on the linear array or area array photosensitive element, but for an area with a more complex surface shape of the measured object, the problem that the position of the wave crest deviates or a plurality of wave crests appear in a signal received by the laser triangular displacement sensor often occurs, and therefore the height information of the surface of the measured object is inaccurate.

Therefore, the prior art is subject to further improvement.

Disclosure of Invention

In view of the defects in the prior art, the invention provides a color triangular displacement sensor based on a triangulation method and a measuring method thereof, and overcomes the defect of low accuracy when a laser triangular displacement sensor in the prior art is used for measuring the height of the surface of an object in a region with a relatively complex surface shape.

In a first aspect, the present embodiment discloses a color triangle displacement sensor based on triangulation, which includes: the system comprises a multi-color point light source, a first dispersive lens group, a second dispersive lens group, a filter, a focusing lens group, a linear array detector and a processor;

the polychromatic point light source is used for emitting polychromatic light;

the first dispersive lens group is used for carrying out axial dispersion on the polychromatic light and focusing the dispersed light with different wavelengths on the surface of a measured object;

the second dispersive lens group is used for receiving the reflected light beam reflected by the surface of the measured object and projecting the reflected light beam to the optical filter;

the optical filter is positioned on the focal plane of the second dispersive lens group and used for receiving the reflected light beam transmitted by the second dispersive lens group and filtering out the reflected light beam with a specific wavelength range; wherein the specific wavelength range is the wavelength range of light focused on the surface of the object to be measured;

the focusing lens group is used for receiving the reflected light beam filtered by the optical filter and focusing the reflected light beam on the linear array detector;

the linear array detector is used for receiving a reflected light beam, acquiring position information of an image point of the reflected light beam and transmitting the acquired position information to the processor;

and the processor is used for obtaining the height information of the surface of the measured object according to the position information.

Optionally, the multi-color point light source includes: the white LED and the shaping lens group are used for shaping the white light emitted by the white LED.

Optionally, the first dispersive lens group and the second dispersive lens group are symmetrical in structure.

Optionally, the first dispersive lens group or the second dispersive lens group includes at least one spherical lens.

Optionally, the optical filter is a circular hole, and the circular hole is disposed on the focal plane of the second dispersive lens group and used for filtering out the light with non-focusing wavelength reflected by the surface of the object to be measured.

Optionally, the linear array detector is a linear array CCD or CMOS.

In a second aspect, a measuring method of a color triangle displacement sensor includes:

the first dispersion lens group is used for carrying out dispersion on the polychromatic light, and the dispersed light rays with different wavelengths are focused on the surface of a measured object;

acquiring position information of a reflected light beam image point reflected by the surface of the measured object by using a linear array detector, and sending the position information to a processor;

and the processor obtains the height information of the measured object according to the position information.

Optionally, before the step of dispersing the polychromatic light, the method includes:

the white light LED is used for emitting white light, the white light is incident to the shaping lens group, and the white light is shaped by the shaping lens group and then emitted.

Optionally, before the step of obtaining the position information of the reflected light beam image point reflected by the surface of the measured object by using the linear array detector, the method further includes:

receiving a reflected light beam reflected on the surface of a measured object by using a second dispersive lens group, emitting the reflected light beam to a filter, filtering the reflected light beam by using the filter, and filtering the reflected light beam with a specific wavelength range;

focusing the filtered reflected light beam on a linear array detector;

optionally, the filter is a circular hole, and the circular hole is disposed on the focal plane of the second dispersive lens group.

Compared with the prior art, the embodiment of the invention has the following advantages:

according to the method provided by the embodiment of the invention, the polychromatic point light source is used as an incident light source, and the method for representing the height information of the measured object by using the position of the highest point of the image surface energy is realized.

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 described in 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 color triangulation displacement sensor based on triangulation in an embodiment of the present invention;

FIG. 2 is a schematic diagram of shaping a point light source according to an embodiment of the present invention;

FIG. 3 is a schematic diagram illustrating the dispersion of light rays in the first dispersive lens group according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of light rays in the second dispersive lens group in an embodiment of the present invention;

fig. 5 is a flowchart of the steps of the measuring method of the color triangular displacement sensor based on the triangulation method in the embodiment of the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer and clearer, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The inventor finds that when a laser triangulation displacement sensor in the prior art measures a surface with a complex shape, the problem that acquired signals are prone to waveform deformation or multiple peaks and accurate measurement results cannot be obtained, and the invention provides a color triangulation displacement sensor based on a triangulation method and a measurement method thereof in order to overcome the defect that the accuracy of data measurement of the laser triangulation displacement sensor in the prior art is low.

The working principle of the color triangular displacement sensor provided by the embodiment is as follows: the point light source is used for emitting polychromatic light, the polychromatic light emitted by the point light source can be subjected to chromatic dispersion through the first chromatic dispersion lens group, the chromatic dispersion enables light rays with different wavelengths in the polychromatic light to have focuses with different heights, and the light rays with different wavelengths are focused to different heights of the surface of an object to be measured; the surface of the measured object reflects the received incident light to form reflected light, the reflected light sequentially passes through the second dispersive lens group, the optical filter and the focusing lens group and finally focuses on the linear array detector, the linear array detector obtains position information of image points of the reflected light and transmits the position information to the processor, and the processor obtains height information on the surface of the measured object according to the received position information.

The sensor and the measuring method thereof disclosed in this embodiment will be further described with reference to specific embodiments.