CN104776907A - Vibration detection method based on multi-point laser speckle extreme value tracking - Google Patents

Abstract

The invention relates to a vibration detection method based on multi-point laser speckle extremum tracking. It is currently impossible to achieve non-destructive telemetry of vibration information. The present invention is based on the principle of multi-point laser speckle and extreme value tracking technology. The laser beam with multiple light intensity peaks is irradiated to the detected area, and the multi-point laser scattering effect occurs in the detected area, and the multi-point laser speckle is imaged through the defocused optical imaging system. , an optical microchannel plate is set in the image space of the out-of-focus optical imaging system, and the speckle out-of-focus image will be transmitted, based on the circuit to perform signal amplification, denoising, information difference and comparison, and obtain the evolution track of the extreme value position of the optical information, The analysis module obtains vibration frequency characteristics and amplitude information. The invention has non-contact detection, non-destructive detection, remote measurement, high sensitivity, high reliability, strong anti-interference ability, wide frequency response characteristics, high information content, easy system construction, convenient use, wide application range, easy function expansion, Easy to integrate and so on.

Description

A vibration detection method based on multi-point laser speckle extremum tracking

technical field

The invention belongs to the field of optical technology, and relates to a vibration detection method, in particular to a vibration detection method based on multi-point laser speckle extremum tracking, which is mainly used in vibration monitoring, noise analysis, voice collection, engineering testing, and risk assessment , environmental perception, quality inspection, environmental monitoring, resource exploration, biological life, medical treatment, process control, national defense security, Internet of Things, process control, advanced manufacturing and other fields of vibration monitoring.

Background technique

Vibration refers to all or part of an object vibrating back and forth along a straight line or a curve, with a certain time law or period. In a broad sense, vibration also includes research engineering content in the fields of acoustics and audio. Vibration detection widely exists in vibration monitoring, noise analysis, voice acquisition, engineering testing, risk assessment, environmental perception, quality testing, environmental monitoring, resource exploration, biological life, medical treatment, process control, national defense security, Internet of things, process control, Advanced manufacturing and other fields, and the requirements for vibration detection are getting higher and higher. There is a vibration information detection method in the prior art, a piezoelectric vibration sensor, (see US patent, patent name: Piezoelectric vibration sensor, inventor: Orten Birger, patent number: US7656524B2, patent authorization time: May 06, 2008 ), although there are certain characteristics, but there are still essential deficiencies. 1) The piezoelectric principle is used for vibration detection, and the vibration sensor is made based on the piezoelectric material, and then the vibration sensor is in contact with the detected object to sense the vibration information, so it is essentially impossible Realize long-distance vibration telemetry; 2) Due to the close interaction between the piezoelectric vibration sensor and the detected object, the detected object and its environment will affect the piezoelectric vibration sensing process, affecting the accuracy and sensitivity of the detection results, and then Affect the reliability of the vibration detection process; 3) Due to the inherent mechanical frequency characteristics of piezoelectric materials and vibration sensors made based on piezoelectric materials, the natural frequency characteristics limit the frequency response behavior of vibration information detection, which not only affects the amount of vibration detection information 〉, which also limits the application range of frequency detection; 4) The previous vibration detection system is complex to construct, inconvenient to use, and difficult to expand functions.

Contents of the invention

The purpose of the present invention is to address the deficiencies of the above-mentioned technologies, and provide a vibration detection method based on multi-point laser speckle extremum tracking, which has non-contact detection, non-destructive detection, remote measurement, high sensitivity, high reliability, strong anti-interference ability, Wide frequency response characteristics, high information content, easy system construction, convenient use, wide application, easy expansion of functions, easy integration and so on.

The basic concept of the present invention is: based on the principle of multi-point laser speckle and extreme value tracking technology, the laser beam with multiple light intensity peaks is irradiated to the detected area, and the multi-point laser scattering effect occurs in the detected area, and the multi-point laser speckle passes through the defocus The optical imaging system performs imaging. An optical microchannel plate is set in the image space of the out-of-focus optical imaging system, and the speckle out-of-focus image will be transmitted. Each optical channel is connected to an optical waveguide, and the other end of the optical waveguide is connected to the photoelectric The sensors are connected to realize the photoelectric conversion of each optical channel. Based on the circuit, signal amplification, denoising, information difference and comparison are performed to obtain the evolution track of the extreme value position of the optical information. The analysis module obtains the vibration frequency characteristics and amplitude information, and outputs through information return The module outputs vibration information.

A vibration detection method based on multi-point laser speckle extremum tracking of the present invention, its specific technical scheme is as follows:

Step (1) The output beam of the laser light source with multiple light intensity peaks is a laser beam with multiple light intensity peaks, and the optical path of the laser beam with multiple light intensity peaks is provided with a beam adjustment component, which adjusts the beam parameters or propagation characteristics to achieve the measurement. Laser beam and direction of propagation;

Step (2) The laser beam is irradiated to the detected area. There is an optical interface in the detected area, and the laser beam is scattered at the optical interface. Through the multi-point laser scattering effect, a laser scattering transmission light field is formed to propagate outward;

Step (3) The multi-point laser speckle that propagates outward in the laser scattering transmission light field is imaged through the defocused optical imaging system. An optical microchannel plate is set in the image space of the defocused optical imaging system, and the defocused image of the speckle will be used to Each optical channel of the optical microchannel plate is connected to an optical waveguide, and the other end of the optical waveguide is connected to a photoelectric sensor to realize the photoelectric conversion of each optical channel;

Step (4) The photoelectric conversion information obtained by photoelectric conversion is amplified and denoised by the signal amplification and denoising module of the photoelectric information of each optical channel, and then the difference, comparison and position of the photoelectric information of all optical channels are performed by the circuit differential comparison module Record;

Step (5) The difference, comparison and position recording results of all optical channel photoelectric information output by the circuit differential comparison module are analyzed by the optical information extreme position evolution track module to obtain the time domain information of the optical information extreme position, and the analysis module obtains the vibration frequency characteristics and amplitude information, the vibration information is output through the information return output module.

The laser light source is one of the lasers that adjust the output of the high-order laser light field in the resonant cavity, and the lasers that modulate the output of the extrinsic mode multi-intensity peak light field outside the cavity.

The laser emitted by the extracavity modulation extrinsic mode multi-intensity peak light field is composed of one of laser diode, diode laser, gas laser, solid-state laser, dye laser or semiconductor laser combined with an extracavity laser adjustment module.

The beam adjustment component is one of a lens-type beam adjustment component, a reflective beam adjustment component, an acousto-optic modulator, an electro-optic modulator, a liquid crystal beam adjustment component, and a micro-nano structured beam adjustment component.

The defocused optical imaging system is one of a refractive optical imaging system, a reflective optical imaging system, and a hybrid optical imaging system.

The photoelectric sensor is one of photodiodes, phototransistors, avalanche tubes and photomultiplier tubes.

The speckle principle, image processing technology, optical microchannel plate and multi-information fusion technology in the present invention are all mature technologies. The invention of the present invention is based on the principle of multi-point laser speckle and extreme value tracking technology, to provide a non-contact detection, non-destructive detection, telemetry, high sensitivity, high reliability, strong anti-interference ability, wide frequency response characteristics A vibration detection method based on multi-point laser speckle extremum tracking, with high information content, easy system construction, convenient use, wide application, easy function expansion, and easy integration.

Compared with prior art, the advantages of the present invention:

1) The prior technology uses the piezoelectric principle for vibration detection, and the vibration sensor is made based on the piezoelectric material, and then the vibration sensor is in contact with the detected object to sense the vibration information, so it is essentially impossible to realize long-distance vibration telemetry. The present invention is based on the principle of multi-point laser speckle and extreme value tracking technology. The laser beam with multiple light intensity peaks is irradiated to the detected area, and the multi-point laser scattering effect occurs in the detected area, and the multi-point laser speckle is imaged through the defocused optical imaging system. , an optical microchannel plate is set in the image space of the out-of-focus optical imaging system, and the out-of-focus image of the speckle will be transmitted, and then detected by the photodetector, and the vibration information is obtained through analysis. The present invention fully utilizes the multi-point laser speckle The principle and long-distance working characteristics of imaging, so it has the characteristics of non-contact detection, non-destructive testing, telemetry, high sensitivity, etc.;

2) Due to the close interaction between the piezoelectric vibration sensor and the detected object in the prior art, the detected object and its environment will affect the piezoelectric vibration sensing process, affect the accuracy and sensitivity of the detection result, and then affect the vibration The reliability of the detection process. The invention is essentially based on the principle of laser speckle telemetry, which essentially avoids direct contact with the detected object, and the optical detection principle is less affected by the external environment. At the same time, it performs signal amplification, denoising, information difference and comparison based on the circuit, so It has the characteristics of high reliability, strong anti-interference ability, various forms and substances of detected objects, and high information content;

3) Due to the inherent mechanical frequency characteristics of piezoelectric materials and vibration sensors made based on piezoelectric materials, the inherent frequency characteristics limit the frequency response behavior of vibration information detection, which not only affects the amount of vibration detection information, but also limits the application range of frequency detection . In the present invention, based on the circuit analysis of the evolution trajectory of the extreme value position of the optical information, the analysis module obtains the vibration frequency characteristics and amplitude information, and the vibration information is output through the information return output module. The frequency characteristics of the present invention are not limited by the mechanical properties of the device, and The photoelectric signal processing speed is fast and the frequency range is wide, which further increases the amount of information;

4) The previous vibration detection system was complex to construct, inconvenient to use, and difficult to expand functions. The present invention adopts the principle of multi-point speckle photoelectric telemetry and optical waveguide technology, and the signal analysis is processed based on hardware circuits, so that the vibration information detection method based on laser speckle behavior of the present invention has simple structure, flexible construction, convenient use, and wide application range. Wide, easy to expand functions, easy to integrate and so on.

Description of drawings

Fig. 1 is a schematic structural diagram of an embodiment of the present invention.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the present invention will be further described.

As shown in Figure 1, an embodiment of a vibration detection method based on multi-point laser speckle extremum tracking, based on the principle of multi-point laser speckle and extremum tracking technology, multi-intensity peak laser beams irradiate the detected area, The multi-point laser scattering effect occurs in the detected area, and the multi-point laser speckle is imaged through the defocused optical imaging system. An optical microchannel plate is set in the image space of the defocused optical imaging system, and the defocused image of the speckle will be transmitted. Based on the circuit, signal amplification, denoising, information difference and comparison are performed to obtain the evolution track of the extreme position of optical information. The analysis module analyzes the vibration frequency characteristics and amplitude information, and the vibration information is output through the information return output module.

The specific implementation steps of this embodiment are:

Step (1) The output beam of the multi-intensity peak laser source 1 is a laser beam with multi-intensity peaks, and the optical path of the laser beam with multi-intensity peaks is provided with a beam adjustment component 2, and the beam adjustment component 2 adjusts beam parameters or propagation characteristics, Reach the laser beam and propagation direction for measurement; in the present embodiment, the laser light source 1 is a laser that adjusts the high-order laser light field to exit in the resonant cavity, and the output wavelength is a helium-neon gas laser with a wavelength of 632.8 nanometers, and the output beam is an advanced Ince beam. The beam adjusting part 2 adopts a lens beam shaping part;

Step (2) The laser beam is irradiated to the detected area, there is an optical interface 3 in the detected area, the laser beam is scattered at the optical interface 3, and the multi-point laser scattering effect forms a laser scattering transmission light field to propagate outward; in this embodiment , there is paper at a distance of 8 meters from the optical interface 3 in the detected area;

Step (3) An optical microchannel plate 5 is set in the image space of the defocused optical imaging system 4, and the speckle defocused image will be transmitted, and each optical channel is connected with an optical waveguide, and the optical microchannel plate 5 is connected with the optical waveguide. The waveguide bundles 6 are connected, and the other end of each optical waveguide of the optical waveguide bundle 6 is connected with a photoelectric sensor to realize the photoelectric conversion of each optical channel, and all the photosensors at the other end of the optical waveguide bundle 6 form a photosensor array 7; In this embodiment, the out-of-focus optical imaging system 4 is a refractive optical imaging, the optical microchannel plate 5 is a glass optical microchannel plate, the optical waveguide bundle 6 is an optical fiber bundle, and the photoelectric sensor array 7 is a photodiode array;

Step (4) The photoelectric conversion information passes through the signal amplification and denoising module 8, and performs signal amplification and denoising of the photoelectric information of each optical channel based on the circuit hardware system, and then uses the circuit differential comparison module 9 to perform differential and denoising of the photoelectric information of all optical channels. comparison and location history;

Step (5) The optical information extremum position evolution track module 10 analyzes the difference, comparison and position recording results of all optical channel photoelectric information output by the circuit differential comparison module 9 to analyze and obtain the time domain information of the optical information extremum position, and the analysis module 11 The vibration frequency characteristics and amplitude information are obtained, and the vibration information is output through the information return output module 12 .

In this embodiment, the telemetry of paper vibration information at a distance of 8 meters is successfully realized. The invention has non-contact detection, non-destructive detection, remote measurement, high sensitivity, high reliability, strong anti-interference ability, wide frequency response characteristics, high information content, easy system construction, convenient use, wide application, easy function expansion, convenient Integration and other features.

The above-mentioned specific embodiments have described the technical solutions and beneficial effects of the present invention in detail. It should be understood that the above-mentioned are only the most preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, supplements and equivalent replacements made within the scope shall be included in the protection scope of the present invention.

Claims (6)

1. A vibration detection method based on multi-point laser speckle extremum tracking, characterized in that it comprises the following steps: Step (1) The output beam of the laser light source with multiple light intensity peaks is a laser beam with multiple light intensity peaks, and the optical path of the laser beam with multiple light intensity peaks is provided with a beam adjustment component, which adjusts the beam parameters or propagation characteristics to achieve the measurement. Laser beam and direction of propagation; Step (2) The laser beam is irradiated to the detected area. There is an optical interface in the detected area, and the laser beam is scattered at the optical interface. Through the multi-point laser scattering effect, a laser scattering transmission light field is formed to propagate outward; Step (3) The multi-point laser speckle that propagates outward in the laser scattering transmission light field is imaged through the defocused optical imaging system. An optical microchannel plate is set in the image space of the defocused optical imaging system, and the defocused image of the speckle will be used to Each optical channel of the optical microchannel plate is connected to an optical waveguide, and the other end of the optical waveguide is connected to a photoelectric sensor to realize the photoelectric conversion of each optical channel; Step (4) The photoelectric conversion information obtained by photoelectric conversion is amplified and denoised by the signal amplification and denoising module of the photoelectric information of each optical channel, and then the difference, comparison and position of the photoelectric information of all optical channels are performed by the circuit differential comparison module Record; Step (5) The difference, comparison and position recording results of all optical channel photoelectric information output by the circuit differential comparison module are analyzed by the optical information extreme position evolution track module to obtain the time domain information of the optical information extreme position, and the analysis module obtains the vibration frequency characteristics and amplitude information, the vibration information is output through the information return output module. 2. A vibration detection method based on multi-point laser speckle extremum tracking as claimed in claim 1, characterized in that: the laser light source is a laser that adjusts the high-order laser light field output in a resonant cavity or an external cavity A laser that emits from a modulated extrinsic mode multi-intensity peak light field. 3. The laser device of extracavity modulation extrinsic mode multi-intensity peak light field exit as claimed in claim 2, characterized in that: the laser device of described extracavity modulation extrinsic mode multi-intensity peak light field exit is composed of One of laser diodes, diode lasers, gas lasers, solid-state lasers, dye lasers or semiconductor lasers is combined with an extracavity laser adjustment module. 4. A vibration detection method based on multi-point laser speckle extremum tracking as claimed in claim 1, characterized in that: said beam adjustment component is a lens-type beam adjustment component, a reflective beam adjustment component, an acousto-optic One of modulators, electro-optic modulators, liquid crystal beam adjustment components, and micro-nano structured beam adjustment components. 5. A kind of vibration detection method based on multi-point laser speckle extremum tracking as claimed in claim 1, characterized in that: the defocused optical imaging system is a refractive optical imaging system, a reflective optical imaging system, One of the hybrid optical imaging systems. 6. A vibration detection method based on multi-point laser speckle extremum tracking as claimed in claim 1, wherein said photoelectric sensor is one of a photodiode, a phototransistor, an avalanche tube, and a photomultiplier tube kind.