CN115685369A - Method and device for detecting solid or liquid attachments on surface of transparent plate - Google Patents
Method and device for detecting solid or liquid attachments on surface of transparent plate Download PDFInfo
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- CN115685369A CN115685369A CN202211207134.1A CN202211207134A CN115685369A CN 115685369 A CN115685369 A CN 115685369A CN 202211207134 A CN202211207134 A CN 202211207134A CN 115685369 A CN115685369 A CN 115685369A
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Abstract
The invention provides a method and a device for detecting solid or liquid attachments on the surface of a transparent plate, wherein the method comprises the following steps: the LED array light source is subjected to on-off control, and output in different coding modes is realized; light rays emitted by the LED array light source are received by the photoelectric detector after being totally reflected by the transparent plate; carrying out single-pixel imaging processing on a signal received by the photoelectric detector so as to realize the detection of solid or liquid attachments; the single-pixel imaging processing method comprises the following steps: recording the image of the attachment as an O matrix, wherein the coding mode is a P matrix, the signal detected and recorded by the photoelectric detector is an S matrix, and the PO = S is obtained by solving the coding matrix P and the signal matrix S to obtain the image O matrix of the attachment; imaging by using an image O matrix of the attachment, and judging the size and the position of the attachment according to the distribution condition of bright and dark points in the imaged image; and refreshing the imaged image by taking the t time interval as a period, and acquiring the dynamic distribution condition of the attachments.
Description
Technical Field
The invention belongs to the field of sensors, and particularly relates to a method and a device for detecting solid or liquid attachments on the surface of a transparent plate.
Background
Solid-liquid detection device takes light rainfall sensor as an example, and rainfall sensor is through detecting the water yield on the windshield before the vehicle, and automatic control windshield wiper keeps glass dry and clean, strengthens the visibility, guarantees that the driver is attentive to drive, reduces accident potential, increases the comfort level of driving. The rainfall compound sensor can be divided into four types of flow type, piezoelectric vibrator type, capacitance type and scattering type in technical principle. The scattering type rainfall detection is a method adopting optical non-contact detection, has the characteristics of obvious light intensity change effect caused by rainfall, mature photoelectric conversion technology, difficulty in electromagnetic interference, installation in a vehicle, no influence of working environment and the like, and is a mainstream technology adopted by the existing rainfall sensor.
The structure of the current scattering type rainfall sensor generally uses light emitted by a light emitting diode to be adjusted by a lens system and then to be irradiated on a windshield in a parallel light state; when the glass is dry, the light rays are totally reflected and pass through the lens system to be in a parallel light state to be received by the receiving device, and the maximum value is output to be 100%; when rain water and raindrops exist on the glass, the light cannot be totally reflected due to the change of the refractive index, but is partially reflected according to the area of the raindrops, at the moment, the receiving tube only receives partial signals, and the rainfall can be calculated according to the percentage ratio. The mode has the characteristics of obvious light intensity change effect caused by rainfall, mature photoelectric conversion technology and difficult electromagnetic interference, but also has the defects of low signal-to-noise ratio caused by easy interference of background light and complicated structure caused by the fact that multiple pairs of optical structures are needed for multi-point detection.
There is an automobile-used blue light rainfall sensor (CN 201410471991.1) that integrated fog detected and rainfall detected, in order to solve the problem that infrared scattering formula rainfall sensor exists, set up two optical channel, adopt two reflection solutions, the response area of every passageway increases, has improved the performance and the reliability of sensor, still can't solve easily receive the background light to disturb and lead to the SNR low, multiple spot detection needs many optical structure and lead to the problem that the structure is complicated.
Disclosure of Invention
The present invention is directed to a method and apparatus for detecting solid or liquid deposits on a surface of a transparent plate.
In order to achieve the purpose, the invention adopts the technical scheme that:
the present invention provides in a first aspect a method for detecting solid or liquid deposits on the surface of a transparent plate, comprising:
the LED array light source is subjected to on-off control, and output in different coding modes is realized;
light rays emitted by the LED array light source are received by the photoelectric detector after being totally reflected by the transparent plate;
carrying out single-pixel imaging processing on signals received by the photoelectric detector to realize detection of solid or liquid attachments;
the single-pixel imaging processing method comprises the following steps:
if the image of the attached matter is recorded as an O matrix, the coding mode is a P matrix, and the signal detected and recorded by the photoelectric detector is an S matrix, the following steps are performed:
wherein, an image with N pixel resolution is obtained through M times of encoding measurement calculation reconstruction, and any row [ P ] of P matrix of encoding mode m1 … P mN ]Is the m-th coding pattern P m In the one-dimensional form of (1), the corresponding measurement signal value of the photodetector is S m ；
Solving through the coding matrix P and the signal matrix S to obtain an image O matrix of the attachment;
imaging by using an image O matrix of the attachment, and judging the size and the position of the attachment according to the distribution condition of bright and dark spots in the imaged image, wherein the bright spots represent a transparent plate, and the dark spots represent the attachment;
and refreshing the imaged image by taking the t time interval as a period, and acquiring the dynamic distribution condition of the attachments.
A second aspect of the present invention provides a solid-liquid detecting apparatus, including: a detection light path part and a data processing part;
the detection light path part comprises:
the LED array is used as a light source and is arranged in a mathematical array mode;
a first lens disposed between the LED array and the transparent plate to map light of the LED array to a surface of the transparent plate;
the second lens is arranged between the transparent plate and the photoelectric detector and used for converging the light totally reflected by the transparent plate to the photoelectric detector;
the photoelectric detector is arranged behind the second lens and used for collecting the light energy converged by the second lens;
the data processing section includes:
the signal acquisition and processing circuit board is used for processing signals of the photoelectric detector;
the main controller is used for completing the method for detecting the solid or liquid attachments on the surface of the transparent plate; the signal acquisition and processing circuit board is electrically connected to receive the signal of the photoelectric detector after signal processing; the control is connected with the LED array to control different switch modes of the LED array through a coding algorithm.
Compared with the prior art, the invention has prominent substantive characteristics and remarkable progress, in particular to the following steps:
1. the invention is based on the principle of total reflection of light, and combines a single-pixel imaging algorithm to realize the detection of the solid-liquid medium;
2. the LED array adopted by the invention has two functions of light source illumination and mode encoding, and the single photoelectric receiver receives the light intensity of multiple light sources and has the characteristic of high signal-to-noise ratio;
3. the optical structure designed by the invention only needs two lenses, and has the characteristics of simple optical structure, small volume, easy miniaturization and high integration level;
4. the imaging adopted by the design of the invention is a Hadamard imaging algorithm, the interference of common-mode noise is eliminated, and the invention has the characteristic of environmental light interference resistance.
Drawings
FIG. 1 is a diagram of raindrop size experiments and imaging results in the method of the present invention.
FIG. 2 is a schematic structural diagram of a detection optical path portion of the solid-liquid detection apparatus according to the present invention.
Detailed Description
The technical solution of the present invention is further described in detail by the following embodiments.
Example 1
The embodiment provides a method for detecting solid or liquid attachments on the surface of a transparent plate, which comprises the following steps:
the LED array light source is subjected to on-off control, and output in different coding modes is realized; specifically, a Hadamard matrix can be used as a coding matrix to perform on-off control on the LED array, so that output in different coding modes is realized;
light rays emitted by the LED array light source are received by the photoelectric detector after being totally reflected by the transparent plate;
carrying out single-pixel imaging processing on a signal received by the photoelectric detector so as to realize the detection of solid or liquid attachments;
the single-pixel imaging processing method comprises the following steps:
when the image of the attached matter is recorded as an O matrix, the coding mode is a P matrix, and the signal detected and recorded by the photoelectric detector is an S matrix, the method comprises the following steps:
wherein, an image with N pixel resolution is obtained through M times of encoding measurement calculation reconstruction, and any row [ P ] of P matrix of encoding mode m1 … P mN ]Is the m-th coding pattern P m In the one-dimensional form of (1), the corresponding measurement signal value of the photodetector is S m ；
Solving through the coding matrix P and the signal matrix S to obtain an image O matrix of the attachment;
imaging by using an image O matrix of the attachment, and judging the size and the position of the attachment according to the distribution condition of bright and dark spots in the imaged image, wherein the bright spots represent a transparent plate, and the dark spots represent the attachment;
and refreshing the imaged image by taking the t time interval as a period, and acquiring the dynamic distribution condition of the attachments.
In this embodiment, the transparent plate is a transparent plate, such as transparent glass or PMMA plate.
The attachment is solid or liquid attachment with refractive index different from that of the transparent plate, such as dust, raindrops, water mist, etc.
The LED array light source is a red LED array light source or a blue LED array light source.
The implementation principle of the invention is illustrated by taking the detection of raindrops on the windshield of an automobile as an example:
as shown in fig. 1, after the LED array light source is encoded, the image point of each point light source of the LED array light source is projected to a different position on the windshield through lens coupling. Under the condition of no rain, light rays can be collected on the photoelectric detector by the lens according to the total reflection characteristic, and the distribution of the image of the LED array on the windshield can be realized through algorithm reduction. Under the condition of rainwater, the total reflection condition is destroyed, light is transmitted out, and after the image of the LED array is restored, the corresponding position of the image is black, so that raindrops at the corresponding position can be judged. The size of the area of the raindrops falling on the surface of the windshield covers the image point of the LED lamp, and the corresponding point is transmitted out and cannot reach the photoelectric detector, so that the size of the raindrops and the quantity of the raindrops at different positions are detected. Meanwhile, with the imaging refreshing, the distribution situation of raindrops in different time periods can be detected, and then the three-dimensional information (x, y, t) of the raindrops is obtained, so that the dynamic distribution situation of the raindrops is detected in real time, and the rainfall situation in different time periods is evaluated.
Example 2
As shown in fig. 2, the present embodiment provides a solid-liquid detecting apparatus, including: a detection light path part and a data processing part;
the detection light path part comprises:
the LED array is used as a light source 1 and is arranged in a mathematical array mode;
a first lens 2 disposed between the LED array and the transparent plate 3 to map light of the LED array to a surface of the transparent plate;
the second lens 4 is arranged between the transparent plate 3 and the photoelectric detector 5 and is used for converging the light totally reflected by the transparent plate 3 to the photoelectric detector;
a photoelectric detector 5 arranged behind the second lens 4 and used for collecting the light energy converged by the second lens;
the data processing section includes:
the signal acquisition and processing circuit board is used for processing the signal of the photoelectric detector;
a main controller for performing the method for detecting solid or liquid attached matter on the surface of the transparent plate described in embodiment 1; the signal acquisition and processing circuit board is electrically connected to receive the signal of the photoelectric detector after signal processing; the control is connected with the LED array to control different switch modes of the LED array through a coding algorithm.
In this embodiment, the photodetector is a barrel-shaped detector having a single detection surface.
In specific implementation, the detection light path part and the data processing part can be accommodated in a shell, and a fixing component, such as a magnetic device and the like, for fixing the solid-liquid detection device on the transparent plate is designed outside the shell.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention and not to limit it; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art will understand that: modifications to the specific embodiments of the invention or equivalent substitutions for parts of the technical features may be made; without departing from the spirit of the present invention, it is intended to cover all aspects of the invention as defined by the appended claims.
Claims (7)
1. A method for detecting solid or liquid deposits on the surface of a transparent plate, comprising:
the LED array light source is subjected to on-off control, and output in different coding modes is realized;
light rays emitted by the LED array light source are received by the photoelectric detector after being totally reflected by the transparent plate;
carrying out single-pixel imaging processing on a signal received by the photoelectric detector so as to realize the detection of solid or liquid attachments;
the single-pixel imaging processing method comprises the following steps:
when the image of the attached matter is recorded as an O matrix, the coding mode is a P matrix, and the signal detected and recorded by the photoelectric detector is an S matrix, the method comprises the following steps:
wherein, an image with N pixel resolution is obtained through M times of encoding measurement calculation reconstruction, and any row [ P ] of P matrix of encoding mode m1 … P mN ]Is the m-th coding pattern P m In the one-dimensional form of (1), the corresponding measurement signal value of the photodetector is S m ；
Solving through the coding matrix P and the signal matrix S to obtain an image O matrix of the attachment;
imaging by using an image O matrix of the attachment, and judging the size and the position of the attachment according to the distribution condition of bright and dark spots in the imaged image, wherein the bright spots represent a transparent plate, and the dark spots represent the attachment;
and refreshing the imaged image by taking the t time interval as a period, and acquiring the dynamic distribution condition of the attachments.
2. The method of claim 1, wherein the Hadamard matrix is used as a coding matrix to switch the LED array, so as to output different coding modes.
3. The method for detecting solid or liquid attachments on the surface of a transparent plate according to claim 1, characterized in that: the transparent plate is a transparent material plate.
4. The method for detecting solid or liquid attachments on the surface of a transparent plate according to claim 1, characterized in that: the adhesive substance is a solid or liquid adhesive substance having a refractive index different from that of the transparent plate.
5. The method for detecting solid or liquid attachments on the surface of a transparent plate according to claim 1, characterized in that: the LED array light source is a red LED array light source or a blue LED array light source.
6. A solid-liquid detecting apparatus, characterized by comprising: a detection light path part and a data processing part;
the detection light path part comprises:
the LED array is used as a light source and is arranged in a mathematical array mode;
a first lens disposed between the LED array and the transparent plate to map light of the LED array to a surface of the transparent plate;
the second lens is arranged between the transparent plate and the photoelectric detector and used for converging the light totally reflected by the transparent plate to the photoelectric detector;
the photoelectric detector is arranged behind the second lens and used for collecting the light energy converged by the second lens;
the data processing section includes:
the signal acquisition and processing circuit board is used for processing the signal of the photoelectric detector;
a main controller for performing the method for detecting solid or liquid attached matter on the surface of the transparent plate according to any one of claims 1 to 5; the signal acquisition and processing circuit board is electrically connected to receive the signal of the photoelectric detector after signal processing; the control is connected with the LED array to control different switch modes of the LED array through a coding algorithm.
7. The solid-liquid detecting apparatus according to claim 6, characterized in that: the photoelectric detector is a barrel-shaped detector with a single detection surface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211207134.1A CN115685369A (en) | 2022-09-30 | 2022-09-30 | Method and device for detecting solid or liquid attachments on surface of transparent plate |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202211207134.1A CN115685369A (en) | 2022-09-30 | 2022-09-30 | Method and device for detecting solid or liquid attachments on surface of transparent plate |
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| CN115685369A true CN115685369A (en) | 2023-02-03 |
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| CN202211207134.1A Pending CN115685369A (en) | 2022-09-30 | 2022-09-30 | Method and device for detecting solid or liquid attachments on surface of transparent plate |
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| CN (1) | CN115685369A (en) |
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