A beam-type laser displacement sensor

Abstract

The present invention discloses a through-beam laser displacement sensor, which adopts a dual-band optical path design. When the sensor is installed for axis alignment, the axis alignment accuracy can be quantitatively displayed. During long-term operation, the axis alignment accuracy can be monitored in real time, and the alarm threshold can be customized according to user needs. When the axis alignment accuracy exceeds the threshold, a warning can be issued to the user, thereby avoiding system errors to a large extent and improving the usability and long-term reliability of the sensor. The present invention adopts a dual-band optical path design. When the sensor is installed for axis alignment, the axis alignment accuracy can be quantitatively displayed. During long-term operation, the axis alignment accuracy can be monitored in real time, and the alarm threshold can be customized according to user needs. When the axis alignment accuracy exceeds the threshold, a warning can be issued to the user, thereby avoiding system errors to a large extent and improving the usability and long-term reliability of the sensor.

Description

Technical Field

[0001] The invention relates to a displacement sensor, in particular to a through-beam laser displacement sensor. Background Art

[0002] In the field of industrial automation, through-beam laser displacement sensors can detect the displacement, outer diameter, position and other information of objects in real time, and play an important role in the stable and reliable operation of industrial production lines. At present, traditional through-beam laser displacement sensors generally use two parts: transmitting and receiving. The transmitting part emits a beam of parallel light, and the receiving part receives and converges the parallel light and irradiates it on the detector. When there is an obstruction in the parallel light, a shadow will be cast on the receiving part. By measuring the position of the shadow, the displacement state of the obstruction can be determined.

[0003] Before being put into use, the through-beam laser displacement sensor needs to be installed by professionals. During installation, it is necessary to ensure that the transmitting and receiving parts are aligned with the optical axis. The more accurate the optical axis is, the smaller the system error will be. However, the actual installation mainly relies on the subjective experience of the installer and the rough judgment of the sensor's own indicator light, and the installation accuracy cannot be quantified. Even if the indicator light shows normal, there is a large margin in the position of the sensor. When the sensor is moved within this margin, all the indicator lights are judged as qualified. Therefore, whether the axis accuracy is not enough during installation or the sensor moves slightly during long-term use, obvious system errors will be introduced. After the sensor has been put into use for a period of time, due to the vibration of industrial equipment, the fixing screws are not firm enough, etc., the position of the sensor is likely to move slightly, causing the optical axis to deviate from the optimal position. At this time, the measurement error of the sensor will increase, but because the sensor itself has a large allowable range for axis accuracy, it will not issue a warning, and the user will continue to use the measurement value with increased error without knowing it. Summary of the invention

[0004] In order to solve the deficiencies of the above-mentioned technology, the present invention provides a through-beam laser displacement sensor.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is a through-beam laser displacement sensor, comprising:

[0006] The sensor head comprises a first sensor head and a second sensor head which are opposite to each other;

[0007] in,

[0008] The first sensor head includes a first laser that emits laser light, a first lens group, a first image sensor that receives laser light from the second sensor head, a first dichroic mirror, a first window lens, and a first circuit module;

[0009] The second sensor head includes a second laser emitting laser, a second lens group, a second image sensor receiving the laser from the first sensor head, a second dichroic mirror, a second window lens, and a second circuit module;

[0010] Controller, used to process data, display values, set parameters and issue alarm signals.

[0011] Furthermore, the first laser and the second laser emit different wavelengths, and the first laser and the second laser are placed parallel to each other and both emit light vertically upward.

[0012] Furthermore, both the first image sensor and the second image sensor are CMOS.

[0013] Further, the first dichroic mirror is implemented in a manner to reflect light emitted by the first laser and transmit light emitted by the second laser;

[0014] The second dichroic mirror is implemented in a manner of reflecting the light emitted by the second laser and transmitting the light emitted by the first laser.

[0015] Further, the first dichroic mirror and the second dichroic mirror are each placed at 45° to the horizontal position.

[0016] Furthermore, the light emitted by the first laser is transformed into parallel light through the first window lens and then emitted;

[0017] The light emitted by the second laser is converted into parallel light through the second window lens and then emitted.

[0018] Furthermore, the first circuit module is used to analyze the measurement value obtained by the first image sensor and transmit it to the controller;

[0019] The second circuit module is used to analyze the measurement value obtained by the second image sensor and transmit it to the controller.

[0020] Furthermore, when there is an object to be measured between the first sensor head and the second sensor head, the object to be measured will block the light from the second image sensor and the first image sensor and obtain a first measurement value and a second measurement value under analysis by the second circuit module and the first circuit module respectively.

[0021] Furthermore, the controller displays the difference between the first measurement value and the second measurement value as the axis accuracy.

[0022] The present invention discloses a through-beam laser displacement sensor, which adopts a dual-band optical path design and can quantitatively display the axis alignment accuracy when the sensor is installed. During long-term operation, the axis alignment accuracy can be monitored in real time, and the alarm threshold can be customized according to user needs. When the axis alignment accuracy exceeds the threshold, a warning can be issued to the user, thereby avoiding system errors to a large extent and improving the usability and long-term reliability of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural diagram of the through-beam laser displacement sensor of the present invention.

[0024] In the figure:

[0025] 10. First sensor head; 11. First laser; 12. First lens group; 13. First image sensor; 14. First dichroic mirror; 15. First window lens; 16. First circuit module;

[0026] 20. Second sensor head; 21. Second laser; 22. Second lens group; 23. Second image sensor; 24. Second dichroic mirror; 25. Second window lens; 26. Second circuit module;

[0027] 30. Controller. DETAILED DESCRIPTION

[0028] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0029] like Figure 1 As shown, this embodiment is about a through-beam laser displacement sensor, specifically a dual-band optical path design, which can display the axis accuracy during installation to ensure the accuracy of installation.

[0030] This embodiment includes a sensor head, including a first sensor head 10 and a second sensor head 20 that are opposite to each other; wherein the first sensor head 10 includes a first laser 11 that emits laser, a first lens group 12, a first image sensor 13 that receives laser from the second sensor head 20, and also includes a first dichroic mirror 14, a first window lens 15, and a first circuit module 16; the second sensor head 20 includes a second laser 21 that emits laser, a second lens group 22, a second image sensor 23 that receives laser from the first sensor head 10, and also includes a second dichroic mirror 24, a second window lens 25, and a second circuit module 26; a controller 30 is used to process data, display values, set parameters and send out alarm signals.

[0031] Preferably, the first laser 11 and the second laser 21 emit different wavelengths, and the first laser 11 and the second laser 21 are placed parallel to each other and both emit light vertically upward.

[0032] In actual use, the first laser 11 can be specifically configured to emit red light, and the wavelength can be 650nm; the second laser 21 can be specifically configured to emit green light, and the wavelength can be 520nm. It should be noted that the first laser 11 and the second laser 21 can achieve the full implementation effect by emitting light of different wavelengths.

[0033] The first image sensor 13 and the second image sensor 23 are both CMOS.

[0034] The first dichroic mirror 14 is implemented in a manner of reflecting the light emitted by the first laser 11 and transmitting the light emitted by the second laser 21. It can be understood that the first dichroic mirror 14 can reflect red light and transmit green light. The second dichroic mirror 24 is implemented in a manner of reflecting the light emitted by the second laser 21 and transmitting the light emitted by the first laser 11. It can be understood that the second dichroic mirror 24 can reflect green light and transmit red light.

[0035] Preferably, the first dichroic mirror 14 and the second dichroic mirror 24 are each placed at 45° to the horizontal position.

[0036] In this embodiment, the red light emitted by the first laser 11 is converted into parallel light and emitted through the first window lens 15 ; the green light emitted by the second laser 21 is converted into parallel light and emitted through the second window lens 25 .

[0037] The first circuit module 16 of this embodiment is used to analyze the measurement value obtained by the first image sensor 13 and transmit it to the controller 30 ; the second circuit module 26 is used to analyze the measurement value obtained by the second image sensor 23 and transmit it to the controller 30 .

[0038] On this basis, when the sensor head of this embodiment is assembled, the first laser 11 emits red light, which is reflected by the first dichroic mirror 14 after passing through the first lens group 12, and becomes parallel light after passing through the first window lens 15. The parallel light converges after passing through the second window lens 25, and irradiates the second image sensor 23 through the second dichroic mirror 24. When there is an object to be measured between the first sensor head 10 and the second sensor head 20, the object to be measured will block part of the light and cast a shadow in the second image sensor 23. The second circuit module 26 analyzes the data of the second image sensor 23 to obtain a measurement value No. 1, and transmits it to the controller 30.

[0039] At the same time, the second laser 21 emits green light, which is reflected by the second dichroic mirror 24 after passing through the second lens group 22, and becomes parallel light after passing through the second window lens 25. The parallel light converges after passing through the first window lens 15, and irradiates the first image sensor 13 through the first dichroic mirror 14. When there is an object to be measured between the first sensor head 10 and the second sensor head 20, the object to be measured will block part of the light and cast a shadow in the first image sensor 13. The first circuit module 16 analyzes the data of the first image sensor 13 to obtain the second measurement value and transmits it to the controller 30.

[0040] For the same object to be tested, the controller 30 displays the average of the measurement value No. 1 and the measurement value No. 2 as the final measurement value, and also calculates the difference between the measurement value No. 1 and the measurement value No. 2, and sets the threshold range of the difference for real-time monitoring. When the difference is within the threshold, the controller 30 displays that the axis is normal, and when the difference is outside the threshold, the controller 30 will issue a warning.

[0041] It should be noted that for the same object to be measured, theoretically, measurement value 1 and measurement value 2 should be equal; during the process of sensor head alignment, the difference represents the alignment accuracy. The closer the difference is to zero, the more accurate the alignment is; the larger the absolute value of the difference is, the less accurate the alignment is.

[0042] In actual use, the threshold range of the axis accuracy can also be set manually according to user requirements. When the sensor is used for a long time and there is a slight movement due to external factors, if the axis accuracy deviates from the threshold range, the controller 30 will issue a warning to the user to facilitate the user to make timely adjustments to avoid introducing additional measurement errors.

[0043] In this way, the through-beam laser displacement sensor disclosed in the present invention adopts a dual-band optical path design, which can quantitatively display the axis alignment accuracy when the sensor is installed. During long-term operation, it can monitor the axis alignment accuracy in real time and can customize the alarm threshold according to user needs. When the axis alignment accuracy exceeds the threshold, a warning can be issued to the user, thereby avoiding system errors to a large extent and improving the usability and long-term reliability of the sensor.

[0044] The above implementation modes are not limitations of the present invention, and the present invention is not limited to the above examples. Any changes, modifications, additions or substitutions made by technicians in this technical field within the scope of the technical solution of the present invention also belong to the protection scope of the present invention.

Claims

1. A through-beam laser displacement sensor, characterized in that: include A sensor head, comprising a first sensor head (10) and a second sensor head (20) which are mutually irradiated; in, The first sensor head (10) comprises a first laser (11) for emitting laser light, a first lens group (12), a first image sensor (13) for receiving laser light from a second sensor head (20), a first dichroic mirror (14), a first window lens (15), and a first circuit module (16); The second sensor head (20) comprises a second laser (21) for emitting laser light, a second lens group (22), a second image sensor (23) for receiving laser light from the first sensor head (10), a second dichroic mirror (24), a second window lens (25), and a second circuit module (26); When there is an object to be measured between the first sensor head (10) and the second sensor head (20), the object to be measured blocks light from the second image sensor (23) and the first image sensor (13), and a first measurement value and a second measurement value are obtained under analysis by the second circuit module (26) and the first circuit module (16), respectively; The controller (30) is used for processing data, displaying numerical values, setting parameters and issuing alarm signals; the controller (30) uses the difference between the first measurement value and the second measurement value as the axis alignment accuracy display.

2. The through-beam laser displacement sensor according to claim 1, characterized in that: The first laser (11) and the second laser (21) emit light of different wavelengths. The first laser (11) and the second laser (21) are placed parallel to each other and emit light vertically upward.

3. The through-beam laser displacement sensor according to claim 1, characterized in that: The first image sensor (13) and the second image sensor (23) are both CMOS.

4. The through-beam laser displacement sensor according to claim 1, characterized in that: The first dichroic mirror (14) is implemented in a manner of reflecting light emitted by the first laser (11) and transmitting light emitted by the second laser (21); The second dichroic mirror (24) is implemented in a manner of reflecting the light emitted by the second laser (21) and transmitting the light emitted by the first laser (11).

5. The through-beam laser displacement sensor according to claim 4, characterized in that: The first dichroic mirror (14) and the second dichroic mirror (24) are each placed at 45° to the horizontal position.

6. The through-beam laser displacement sensor according to claim 1, characterized in that: The light emitted by the first laser (11) is transformed into parallel light and emitted through a first window lens (15); The light emitted by the second laser (21) is converted into parallel light through the second window lens (25) and then emitted.

7. The through-beam laser displacement sensor according to claim 1, characterized in that: The first circuit module (16) is used to analyze the measurement value obtained by the first image sensor (13) and transmit it to the controller (30); The second circuit module (26) is used to analyze the measurement value obtained by the second image sensor (23) and transmit it to the controller (30).

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