CN-121977455-A - Displacement sensor and displacement measurement method

Abstract

The application provides a displacement sensor and a displacement measurement method, wherein the displacement sensor comprises a circuit unit, a focusing imaging unit, at least one wavelength beam combining unit, at least one light splitting unit, a plurality of signal receiving units and a plurality of light sources with different wavelengths, each light source is arranged on an incident light path of the corresponding wavelength beam combining unit, different light sources irradiate a measured object through the wavelength beam combining unit, the focusing imaging unit is positioned on a reflection light path of the light source irradiating the measured object, the light splitting unit is positioned on an emergent light path of the focusing imaging unit, and each signal receiving unit is positioned on an emergent light path of the corresponding light splitting unit, so that the light sources with different wavelengths are respectively received by the corresponding signal receiving units. The application integrates a plurality of light sources with different wavelengths and a plurality of signal receiving units, is equivalent to a single probe displacement sensor integrating a plurality of displacement sensors into a whole, and can meet the measurement requirements of different measuring ranges, different precision and different workpiece colors.

Inventors

• XIE BENCHAO
• YAO WENZHENG

Assignees

• 光子(深圳)精密科技有限公司

Dates

Publication Date

20260505

Application Date

20260409

Claims (10)

1. 1. The displacement sensor is characterized by comprising a circuit unit, a focusing imaging unit, at least one wavelength beam combining unit, at least one light splitting unit, a plurality of signal receiving units and a plurality of light sources with different wavelengths, wherein each light source is arranged on an incident light path of the corresponding wavelength beam combining unit, so that different light sources irradiate on a measured object through a fixed emergent light path of the wavelength beam combining unit, the focusing imaging unit is arranged on a reflected light path of the light source irradiating on the measured object, the light splitting unit is arranged on an emergent light path of the focusing imaging unit, each signal receiving unit is positioned on an emergent light path of the corresponding light splitting unit, the light sources with different wavelengths are respectively received by the corresponding signal receiving units, and the light sources and the signal receiving units are electrically connected with the circuit unit.
2. 2. The displacement sensor of claim 1, wherein the number of the wavelength beam combining units is plural, and all the wavelength beam combining units are arranged in a straight line at intervals, so that the outgoing light of one wavelength beam combining unit can enter the adjacent other wavelength beam combining unit until the outgoing light irradiates on the object to be measured.
3. 3. The displacement sensor of claim 2, wherein the number of the light splitting units is one, and the light splitting units are light splitting elements which can transmit one wavelength light source and can reflect a plurality of different wavelength light sources; Or the number of the light splitting units is one, and the light splitting units are light splitting elements which can transmit a plurality of light sources with different wavelengths and can reflect one wavelength light source; Or the number of the light splitting units is one, and the light splitting units are light splitting elements which can transmit a plurality of light sources with different wavelengths and can reflect the light sources with different wavelengths.
4. 4. A displacement sensor according to claim 3, wherein the light splitting unit is a dichroic mirror, and the number of the signal receiving units is two, wherein one of the signal receiving units is located on a reflected light path of the light splitting unit, and the other signal receiving unit is located on a transmitted light path of the light splitting unit.
5. 5. The displacement sensor of claim 2, wherein the number of the light-splitting units is plural, and all the light-splitting units are arranged in a straight line at intervals, so that the light source with a specific wavelength can sequentially transmit all the light-splitting units, and the light sources with other wavelengths are reflected by a corresponding one of the light-splitting units.
6. 6. The displacement sensor according to claim 5, wherein the light-splitting unit is a dichroic mirror, the plurality of signal receiving units are provided, one signal receiving unit is provided on a reflection light path of each light-splitting unit, and one signal receiving unit is provided on a transmission light path of one light-splitting unit farthest from the focusing imaging unit.
7. 7. The displacement sensor of claim 1, wherein the number of wavelength combining units is one, the number of beam splitting units is a dichroic mirror and the number is one, the number of signal receiving units is a CMOS detector and the number is two, one of the signal receiving units is located on a reflected light path of the beam splitting unit, and the other of the signal receiving units is located on a transmitted light path of the beam splitting unit.
8. 8. The displacement sensor of claim 1, further comprising a collimating unit disposed on an outgoing light path of the wavelength beam combining unit for collimating and focusing outgoing light of the wavelength beam combining unit; Or a collimation unit is arranged between each light source and the corresponding wavelength beam combination unit and is used for collimating and focusing the incident light of the wavelength beam combination unit.
9. 9. The displacement sensor according to any one of claims 1 to 8, wherein the focused imaging unit is a fixed focal length lens or a lens group of adjustable focal length; And/or the circuit unit comprises a range precision switching module, wherein the range precision switching module is used for automatically switching the light source with the corresponding wavelength and the corresponding signal receiving unit according to one or more of a user instruction, a measured distance, a measured object color, a measured object surface characteristic, a range requirement and a precision requirement; And/or the light source is one of a laser diode, a light-emitting diode and a super-radiation light-emitting diode; And/or the wavelength beam combining unit is a multilayer dielectric film wavelength beam combining lens; And/or the light splitting unit is a dichroic mirror; And/or the signal receiving unit is one of a CMOS detector, a PSD position sensitive detector and a CCD detector.
10. 10. A displacement measurement method employing the displacement sensor according to any one of claims 1 to 9, characterized in that the displacement measurement method comprises: Selecting and emitting a light source from a plurality of light sources with different wavelengths according to requirements, so that the light source irradiates on a measured object through a fixed emergent light path after being reflected and/or transmitted by at least one wavelength beam combining unit; the light source forms a focusing light beam through the focusing imaging unit after being reflected by the measured object; the focused light beam is received by one of the signal receiving units after being reflected and/or transmitted by at least one of the beam splitting units, and the displacement of the measured object is determined according to the received signal.

Description

Displacement sensor and displacement measurement method Technical Field The application belongs to the technical field of sensors, and particularly relates to a displacement sensor compatible with various wavelengths, various ranges and various accuracies, and a displacement measurement method. Background Along with the rapid development of intelligent manufacturing, precise detection, industrial Internet of things and high-end equipment, the requirements of non-contact, high-precision, high-dynamic and strong-adaptation displacement measurement are continuously upgraded, and a laser displacement sensor has become a mainstream technical scheme in the field of precise measurement and is widely applied to scenes such as semiconductors, 3C electronics, automobile manufacturing, photovoltaics, robots, rail transit, scientific research detection and the like. The current laser displacement sensor has completed technical iteration from analog signal, digital processing to intellectualization, networking, microminiaturization and multi-scene adaptation, forms a mature technical system taking optical imaging, photoelectric detection, high-speed signal processing and intelligent algorithm as cores, and integrally develops towards the directions of higher precision, higher speed, stronger environmental adaptability, smaller volume and easier integration. Because the application scenes of the displacement sensor are more and more diversified, different requirements are also met on the measuring range and the precision of the sensor, the displacement sensors with different wavelengths, different precision and different measuring ranges are required to be selected correspondingly, so that a plurality of displacement sensors are required to be configured, or the displacement sensors with multiple probes are adopted to meet the diversified requirements under different scenes, the cost is high, and the sensors with different measuring ranges and precision are required to be switched when in use, so that inconvenience is brought to operation and maintenance. Disclosure of Invention The embodiment of the application aims to provide a displacement sensor so as to solve the technical problems of high cost and inconvenient operation in the prior art that a plurality of sensors are required to be configured or a plurality of probes are adopted to meet the requirements of diversified application scenes. In order to achieve the above purpose, the application adopts the technical scheme that the displacement sensor comprises a circuit unit, a focusing imaging unit, at least one wavelength beam combining unit, at least one light splitting unit, a plurality of signal receiving units and a plurality of light sources with different wavelengths, wherein each light source is arranged on an incident light path of the corresponding wavelength beam combining unit, so that different light sources can irradiate a tested object through a fixed emergent light path of the wavelength beam combining unit, the focusing imaging unit is arranged on a reflected light path of the light source irradiated on the tested object, the light splitting unit is arranged on an emergent light path of the focusing imaging unit, each signal receiving unit is positioned on an emergent light path of the corresponding light splitting unit, the light sources with different wavelengths are respectively received by the corresponding signal receiving units, and the light sources and the signal receiving units are electrically connected with the circuit unit. In an embodiment, the number of the wavelength beam combining units is a plurality, and all the wavelength beam combining units are arranged in a straight line at intervals, so that the emergent light of one wavelength beam combining unit can enter another adjacent wavelength beam combining unit until the emergent light irradiates on the object to be measured. In one embodiment, the number of the light splitting units is one, and the light splitting units are light splitting elements which can transmit one wavelength light source and can reflect a plurality of different wavelength light sources; Or the number of the light splitting units is one, and the light splitting units are light splitting elements which can transmit a plurality of light sources with different wavelengths and can reflect one wavelength light source; Or the number of the light splitting units is one, and the light splitting units are light splitting elements which can transmit a plurality of light sources with different wavelengths and can reflect the light sources with different wavelengths. In an embodiment, the light splitting unit is a dichroic mirror, and the number of the signal receiving units is two, wherein one signal receiving unit is located on a reflection light path of the light splitting unit, and the other signal receiving unit is located on a transmission light path of the light splitting unit. In an embodiment, the number of the l