CN108872952A - A kind of reflective optical fiber displacement sensor situ calibration system and method - Google Patents

Abstract

The invention discloses an on-site calibration system and method for a reflective optical fiber displacement sensor. The system includes: a workbench, a reflective optical fiber displacement sensor, a laser displacement sensor, a target base and a central processing unit, a reflective optical fiber displacement sensor, and a laser displacement sensor , Target bases are all arranged above the workbench and connected to the central processing unit; the present invention uses a laser displacement sensor as a reference, and stores the displacement value and the voltage value after accurate timing, so as to correspond to the measurement point of the generated calibration curve Many, effectively increasing the accuracy of the calibration curve generated by the subsequent fitting process; the reflective fiber optic displacement sensor includes a fiber optic probe, and the fiber optic probe is equipped with a coaxially arranged launch fiber, reference fiber and receive fiber, and the launch fiber and receive fiber are at the same time The axis is arranged in multiple layers, and the reference optical fiber is set, which increases the sensitivity and resolution of the reflective optical fiber displacement sensor and improves its working performance.

Description

A system and method for on-site calibration of reflective optical fiber displacement sensor

technical field

The invention relates to the technical field of reflective optical fiber displacement sensing, in particular to an on-site calibration system and method for a reflective optical fiber displacement sensor.

Background technique

Reflective optical fiber displacement sensing technology is a continuous light source as the measurement carrier, the light intensity as the measurement signal, and the optical fiber as the propagation medium. By sensing the measured signal and distinguishing the relationship between the received signal and the transmitted signal, the displacement of the measured object can be obtained. Technology (references: Cong Hong, reflective optical fiber micro-displacement sensor. 2003). Compared with other displacement sensors, optical fiber displacement sensors have the characteristics of high frequency response (high sensitivity), non-contact measurement, small size, simple structure, resistance to electrical interference, and suitable for soft objects, etc., so they have been widely used.

However, due to the influence of the shape of the reflective surface and the material of the measured surface, even when the same sensor measures different objects, the output voltage-displacement curves are usually very different. Therefore, fiber optic sensor manufacturers usually only provide a schematic diagram of a modeled voltage-displacement curve when selling their products. When applying, users need to calibrate according to the specific use environment, especially the nature of the reflective surface. When the measured object or measurement environment changes frequently, this kind of calibration needs to be repeated.

Therefore, providing an on-site calibration system and method for reflective optical fiber displacement sensors to solve the above-mentioned shortcomings in the prior art has become a technical problem to be solved urgently.

Contents of the invention

The purpose of the present invention is to provide a reflective optical fiber displacement sensor on-site calibration system and method, to solve the above-mentioned problems in the prior art, to establish a high-precision on-site calibration system and method suitable for different reflection conditions, and Improve the sensitivity and measurement accuracy of the reflective optical fiber displacement sensor.

In order to achieve the above object, the present invention provides the following scheme: the present invention provides a reflective optical fiber displacement sensor on-site calibration system, including: a workbench, a reflective optical fiber displacement sensor, a laser displacement sensor, a target base and a central processing unit; The reflective optical fiber displacement sensor, the laser displacement sensor, and the target base are all arranged above the workbench and connected to the central processing unit; the reflective optical fiber displacement sensor and the laser displacement sensor are arranged side by side, and the The reflective optical fiber displacement sensor includes an optical fiber probe arranged in front of it, and coaxially arranged emitting optical fiber, reference optical fiber and receiving optical fiber are arranged in the optical fiber probe; the target base is used to install the object to be measured, and is located in the On the side of the table opposite to the optical fiber probe, the target base is slidably connected to the worktable.

Preferably, the reflective optical fiber displacement sensor further includes a light source and a photodetector, the emitting optical fiber is connected to the light source, and both the reference optical fiber and the receiving optical fiber are connected to the photodetector.

Preferably, the upper middle part of the target base is provided with a mounting seat, and the mounting seat includes a limit plate for limiting the surface to be measured of the object to be measured and a fixing clip for fixing the object to be measured, and the fixing clip is located at The limiting plate is away from the side of the fiber optic probe.

Preferably, a guide rail is provided above the workbench, and the bottom of the target base is slidably connected with the workbench through the guide rail; a stepping motor is provided on the side of the target base away from the fiber optic probe, so that The stepper motor drives the target base to move through a lead screw.

Preferably, the central processing unit includes a preprocessing unit, a driving unit, a measuring unit, a drawing unit and a display, the driving unit is respectively coupled to the preprocessing unit and the measuring unit, and the measuring unit is also connected to the The display unit is coupled to the drawing unit, and the display is connected to the drawing unit in a signal manner.

Preferably, there are multiple reference optical fibers and multiple receiving optical fibers, multiple reference optical fibers are disposed around the outside of the transmitting optical fiber, and multiple receiving optical fibers are disposed around the reference optical fiber.

Preferably, there are multiple emitting optical fibers and receiving optical fibers, the multiple emitting optical fibers are arranged around the outside of the reference optical fiber, and the multiple receiving optical fibers are arranged around the emitting optical fiber.

Preferably, the light source is a semiconductor laser with a wavelength of 600-650nm; the driving circuit of the light source adopts DC drive or pulse drive.

The present invention also provides a method for on-site calibration of a reflective optical fiber displacement sensor, comprising the steps of:

1) Install the object to be tested on the mounting seat above the target base, limit the surface of the object to be tested with a limit plate, fix the object to be tested with a fixing clip, and turn on the system power;

2), the preprocessing unit monitors whether the target base is within the effective range of the laser displacement sensor and the reflective optical fiber displacement sensor; if it is not within the effective range, adjust the target base to the effective range of the laser displacement sensor and the reflective optical fiber displacement sensor;

3) When the target base is adjusted to the effective range of the laser displacement sensor and the reflective optical fiber displacement sensor, the preprocessing unit presets the predetermined moving speed, predetermined moving distance and predetermined moving direction of the target seat;

4) The drive unit controls the stepper motor to drive the target base to move according to the predetermined moving speed, predetermined moving distance and predetermined moving direction;

5), the measurement unit calculates the actual moving speed of the target base, and judges whether the actual moving speed is consistent with the predetermined moving speed, if not, adjust the actual moving speed of the target base;

6) When the actual moving speed of the target base is consistent with the predetermined moving speed, the measurement unit reads the displacement value collected by the laser displacement sensor and the voltage value collected by the photodetector of the reflective optical fiber displacement sensor;

7) The drawing unit stores the displacement value and the voltage value accurately, and performs fitting processing to generate a calibration curve, and then outputs the calibration curve to the display.

Compared with the prior art, the present invention has achieved the following technical effects:

1. Using the laser displacement sensor as a reference, the displacement value and voltage value are accurately timed and then stored, so that there are many measurement points for the corresponding calibration curve, which effectively increases the accuracy of the calibration curve generated by the subsequent fitting process;

2. The transmitting fiber and receiving fiber are coaxially arranged in multiple layers, and the reference fiber is set, which increases the sensitivity and resolution of the reflective fiber optic displacement sensor and improves its working performance;

3. The limit plate is set on the target base, which can limit the surface of the object to be tested, avoiding the adjustment of the position of the target base due to the different thickness of the object to be measured, and the operation is simple.

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 accompanying drawings required in the embodiments. Obviously, the accompanying drawings in the following description are only some of the present invention. Embodiments, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without any creative effort.

Fig. 1 is the structural representation of the on-site calibration system of the reflective optical fiber displacement sensor of the present invention;

Fig. 2 is the structural representation of embodiment one optical fiber probe;

Fig. 3 is the structural representation of embodiment two optical fiber probes;

Among them, 1 is the workbench, 2 is the laser displacement sensor, 3 is the reflective optical fiber displacement sensor, 4 is the optical fiber probe, 41 is the transmitting optical fiber, 42 is the reference optical fiber, 43 is the receiving optical fiber, 5 is the target seat, 51 is the mounting seat , 52 is a limiting plate, 6 is a stepper motor, and 61 is a leading screw.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The purpose of the present invention is to provide a reflective optical fiber displacement sensor on-site calibration system and method, to solve the above-mentioned problems in the prior art, to establish a high-precision on-site calibration system and method suitable for different reflection conditions, and Improve the sensitivity and measurement accuracy of the reflective optical fiber displacement sensor.

In order to make the above objects, features and advantages of the present invention more comprehensible, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Embodiment one,

This embodiment provides a reflective optical fiber displacement sensor on-site calibration system, as shown in Figure 1 and Figure 2, including: a workbench 1, a reflective optical fiber displacement sensor 3, a laser displacement sensor 2, a target holder 5 and a central processing unit The reflective optical fiber displacement sensor 3, the laser displacement sensor 2, and the target base 5 are all arranged on the top of the workbench 1, and are connected with the central processing unit, measure and record the information of each part by the central processing unit, and check each part Take control.

The reflective optical fiber displacement sensor 3 and the laser displacement sensor 2 are arranged side by side on the workbench 1 through a fixed bracket, and the laser displacement sensor 2 is used as a reference to accurately compare the displacement value of the laser displacement sensor 2 and the voltage value of the reflective optical fiber displacement sensor 3 After a period of time, it is stored, so that there are many measurement points corresponding to the generated calibration curve, which effectively increases the accuracy of the calibration curve generated by the subsequent fitting process.

Wherein, the reflective optical fiber displacement sensor 3 includes an optical fiber probe 4 arranged in front of it, and a coaxially arranged transmitting optical fiber 41, a reference optical fiber 42 and a receiving optical fiber 43 are arranged in the optical fiber probe 4, and the reflective optical fiber displacement sensor 3 also includes a light source and Photodetectors, two photodetectors are provided, the emitting optical fiber 41 is connected to the light source, and is used to emit light to irradiate the object to be measured, and the reference optical fiber 42 and receiving optical fiber 43 are respectively connected to a photodetector for receiving light; Compared with the prior art, a reference optical fiber 42 is added to connect with the photodetector to form a reference optical path, which compensates the voltage value measured by the photodetector and effectively eliminates the influence of light source fluctuation on measurement accuracy.

A plurality of reference optical fibers 42 and receiving optical fibers 43 are provided, a plurality of reference optical fibers 42 are arranged around the outer side of the emitting optical fiber 41, and a plurality of receiving optical fibers 43 are arranged around the reference optical fiber 42; The multi-layer arrangement of axes has good symmetry, which can make it easier for the light emitted by the light source to be coupled into the fiber optic probe 4, ensuring the transmission of a large illumination light power, thereby improving the measurement accuracy and reducing the fiber optic probe 4. The influence of the installation angle of the object under test on the calibration curve; moreover, the combination of the optical fiber coaxial multi-layer arrangement and the reference optical path and the receiving optical path double optical path increases the sensitivity and resolution of the reflective optical fiber displacement sensor 3 and improves its work performance. The light source connected to the emitting fiber 41 is a semiconductor laser with a wavelength of 600-650nm; the driving circuit of the light source adopts DC drive or pulse drive, thereby improving the stability of the light source and further improving the measurement accuracy.

The upper part of the target base 5 is used for installing the object to be measured, and is located on the side of the workbench 1 opposite to the fiber optic probe 4 , and the target base 5 is slidably connected with the workbench 1 . The upper middle part of the target base 5 is provided with a mounting base 51, the mounting base 51 includes a limit plate 52 and a fixing clip, the object to be measured is installed in the mounting base 51, and the surface to be measured of the object to be measured is perpendicular to the fiber optic probe 4, which is convenient for measurement. And it is close to the inner side of the limit plate 52, so that the surface to be measured is limited by the limit plate 52, so that the distance between the surface to be measured and the optical fiber probe 4 and the laser displacement sensor 2 is fixed, so as to prevent changes in the thickness of the object to be measured due to different thicknesses of the object to be measured. The distance between the measuring surface and the optical fiber probe 4 and the laser displacement sensor 2 results in that the object to be measured is not within the effective range of the laser displacement sensor 2 and the reflective optical fiber displacement sensor 3, thereby avoiding repeated adjustment of the position of the target seat 5, and the operation is simple. save time and energy. The fixing clip is located on the side of the limiting plate 52 away from the fiber optic probe 4, and can effectively fix the object to be tested.

There is a guide rail above the workbench 1, and the bottom of the target base 5 is slidingly connected with the workbench 1 through the guide rail; the side of the target base 5 away from the fiber optic probe 4 is provided with a stepping motor 6, and the stepping motor 6 is driven by a precision screw 61 The movement of the target base 5 improves the accuracy of the movement of the target base 5 and reduces errors caused by manual movement. And the stepper motor 6 drives the target base 5 to move through the precision screw rod 61, and the rotation of the screw 61 drives the target base 5 to move horizontally along the guide rail, avoiding the direct straight line when the target base 5 moves, due to the inertia of the target base 5 The motion error brought about improves the accuracy.

The central processing unit includes a preprocessing unit, a driving unit, a measuring unit, a drawing unit and a display. The preprocessing unit monitors the position of the target base 5, and monitors whether it is within the range of the laser displacement sensor 2 and the reflective optical fiber displacement sensor 3. The preprocessing unit is coupled with the drive unit, and the target base 5 is adjusted to the laser displacement sensor through the drive unit. 2 and the effective range of the reflective optical fiber displacement sensor 3, then the preprocessing unit presets the predetermined moving speed, predetermined moving distance and predetermined moving direction of the target holder 5. The drive unit is connected with the stepper motor 6 by signal, and the stepper motor 6 is controlled to drive the target holder 5 to move according to a predetermined moving speed, a predetermined moving distance and a predetermined moving direction. The measuring unit is coupled with the driving unit, and the measuring unit calculates the actual moving speed of the target base 5, and judges whether the actual moving speed is consistent with the predetermined moving speed; if not, adjust the actual moving speed of the target base 5 through the driving unit; then the measuring unit reads Take the displacement value collected by the laser displacement sensor 2 and the voltage value collected by the photodetector of the reflective optical fiber displacement sensor 3 . The drawing unit is coupled with the measuring unit, and the displacement value and the voltage value measured by the measuring unit are accurately timed, stored, and fitted to generate a calibration curve; then the calibration curve is output to a display connected to the drawing unit signal, Easy to view.

This embodiment also discloses a method for on-site calibration of a reflective optical fiber displacement sensor based on the above-mentioned on-site calibration system for a reflective optical fiber displacement sensor, including the following steps:

1), install the object to be measured on the mounting seat 51 above the target base 5, limit the surface to be measured of the object to be measured with the limit plate 52, fix the object to be measured with the fixing clip, and turn on the system power supply;

2), the preprocessing unit monitors whether the target base 5 is within the effective range of the laser displacement sensor 2 and the reflective optical fiber displacement sensor 3; if not within the effective range, adjust the target base 5 to the laser displacement sensor 2 and the reflective optical fiber displacement sensor 3 within the effective range;

3), when the target holder 5 is adjusted to the effective range of the laser displacement sensor 2 and the reflective optical fiber displacement sensor 3, the preprocessing unit presets the predetermined moving speed, predetermined moving distance and predetermined moving direction of the target holder 5;

4), the drive unit controls the stepper motor 6 to drive the target holder 5 to move according to the predetermined moving speed, predetermined moving distance and predetermined moving direction;

5), the measurement unit calculates the actual moving speed of the target holder 5, and judges whether the actual moving speed is consistent with the predetermined moving speed, if not, adjust the actual moving speed of the target holder 5;

6), when the actual moving speed of the target base 5 is consistent with the predetermined moving speed, the measuring unit reads the displacement value collected by the laser displacement sensor 2 and the voltage value collected by the photodetector of the reflective optical fiber displacement sensor 3;

7) The drawing unit stores the displacement value and the voltage value accurately, and performs fitting processing to generate a calibration curve, and then outputs the calibration curve to the display.

This embodiment improves the sensitivity and measurement accuracy of the reflective optical fiber displacement sensor, and establishes a high-precision on-site calibration system and method suitable for different reflection conditions.

Embodiment two,

This embodiment is an improvement made on the basis of Embodiment 1. The only improvement is the difference in the structure of the fiber optic probe 4. As shown in FIG. 42 and receiving optical fiber 43, multiple emitting optical fibers 41 and receiving optical fibers 43 are provided, multiple emitting optical fibers 41 are arranged around the outside of the reference optical fiber 42, and multiple receiving optical fibers 43 are arranged around the emitting optical fiber 41.

This embodiment adopts the coaxial multi-layer arrangement of the transmitting optical fiber 41, the reference optical fiber 42 and the receiving optical fiber 43, which has good symmetry and can make it easier for the light emitted by the light source to be coupled into the optical fiber probe 4, ensuring the transmission of larger Illumination light power, so as to improve the measurement accuracy, and reduce the impact of the installation angle of the optical fiber probe 4 and the object to be measured on the calibration curve; moreover, the combination of the coaxial multi-layer arrangement of the optical fiber and the reference optical path and the combination of the double optical path of the receiving optical path, The sensitivity and resolution of the reflective optical fiber displacement sensor 3 are increased to improve its working performance.

In the present invention, specific examples have been used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only used to help understand the method and core idea of the present invention; meanwhile, for those of ordinary skill in the art, according to the present invention The idea of the invention will have changes in the specific implementation and scope of application. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims (9)

1. A reflective optical fiber displacement sensor on-site calibration system is characterized in that: comprising: workbench, reflective optical fiber displacement sensor, laser displacement sensor, target holder and central processing unit; Described reflective optical fiber displacement sensor, laser displacement sensor The sensor and the target base are all arranged above the workbench and connected to the central processing unit; the reflective optical fiber displacement sensor and the laser displacement sensor are arranged side by side, and the reflective optical fiber displacement sensor includes a The fiber optic probe at the front, the fiber optic probe is provided with a coaxial launch fiber, reference fiber and receiving fiber; On one side, the target base is slidingly connected with the workbench. 2. The reflective optical fiber displacement sensor field calibration system according to claim 1, characterized in that: the reflective optical fiber displacement sensor also includes a light source and a photodetector, the emitting optical fiber is connected with the light source, and the Both the reference fiber and the receiving fiber are connected to the photodetector. 3. The on-site calibration system for reflective optical fiber displacement sensor according to claim 2, characterized in that: the upper middle part of the target seat is provided with a mounting seat, and the mounting seat includes a surface to be measured for limiting the object to be measured A limiting plate and a fixing clip for fixing the object to be measured, the fixing clip is located on the side of the limiting plate away from the fiber optic probe. 4. The on-site calibration system for reflective optical fiber displacement sensor according to claim 3, characterized in that: a guide rail is arranged above the workbench, and the bottom of the target base is slidably connected with the workbench through the guide rail ; The side of the target base away from the fiber optic probe is provided with a stepping motor, and the stepping motor drives the movement of the target base through a lead screw. 5. reflective optical fiber displacement sensor field calibration system according to claim 4, is characterized in that: described central processing unit comprises preprocessing unit, driving unit, measurement unit, drawing unit and display, and described driving unit is respectively connected with The preprocessing unit is coupled to the measurement unit, the measurement unit is also coupled to the rendering unit, and the display is connected to the rendering unit with signals. 6. The on-site calibration system for reflective optical fiber displacement sensors according to claim 2, characterized in that: multiple reference fibers and receiving fibers are provided, and a plurality of reference fibers are arranged around the outside of the transmitting fiber , a plurality of receiving optical fibers are arranged around the reference optical fiber. 7. The on-site calibration system for reflective optical fiber displacement sensors according to claim 2, characterized in that: the transmitting optical fiber and the receiving optical fiber are provided with a plurality, and a plurality of the transmitting optical fibers are arranged around the outer side of the reference optical fiber , a plurality of receiving optical fibers are arranged around the emitting optical fiber. 8. The on-site calibration system for reflective optical fiber displacement sensors according to claim 2, characterized in that: the light source is a semiconductor laser with a wavelength of 600-650 nm; the driving circuit of the light source adopts DC drive or pulse drive. 9. a reflective optical fiber displacement sensor field calibration method, is characterized in that: comprise the steps: 1) Install the object to be tested on the mounting seat above the target base, limit the surface of the object to be tested with a limit plate, fix the object to be tested with a fixing clip, and turn on the system power; 2), the preprocessing unit monitors whether the target base is within the effective range of the laser displacement sensor and the reflective optical fiber displacement sensor; if it is not within the effective range, adjust the target base to the effective range of the laser displacement sensor and the reflective optical fiber displacement sensor; 3) When the target base is adjusted to the effective range of the laser displacement sensor and the reflective optical fiber displacement sensor, the preprocessing unit presets the predetermined moving speed, predetermined moving distance and predetermined moving direction of the target base; 4) The drive unit controls the stepper motor to drive the target base to move according to the predetermined moving speed, predetermined moving distance and predetermined moving direction; 5), the measurement unit calculates the actual moving speed of the target base, and judges whether the actual moving speed is consistent with the predetermined moving speed, if not, adjust the actual moving speed of the target base; 6) When the actual moving speed of the target base is consistent with the predetermined moving speed, the measurement unit reads the displacement value collected by the laser displacement sensor and the voltage value collected by the photodetector of the reflective optical fiber displacement sensor; 7) The drawing unit stores the displacement value and the voltage value accurately, and performs fitting processing to generate a calibration curve, and then outputs the calibration curve to the display.