CN108169757B - High-precision identification light measurement system and method for central pixel - Google Patents
High-precision identification light measurement system and method for central pixel Download PDFInfo
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
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- G01S17/06—Systems determining position data of a target
- G01S17/08—Systems determining position data of a target for measuring distance only
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
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Abstract
The invention provides a high-precision identification light measurement system and method for a central pixel, wherein the system comprises a light emitting device, a diaphragm, a band-pass filter, a measured object, a narrow-band filter, a focusing device, an image sensor and a signal processing device; the light emitting device, the diaphragm, the band-pass filter and the measured object are sequentially arranged along a first light path; the object to be measured, the band-pass filter, the focusing device and the image sensor are sequentially arranged along a second light path; the light emitting device comprises a light emitter, and a light driving circuit and a light power control circuit which are connected with the light emitter; the image sensor is connected with the signal processing device. The system and the method for high-precision identification of the light measurement by the central pixel solve the problem of light triangulation precision from the system angle by controlling the measurement key parameters, and have the advantages of low cost and high measurement precision.
Description
Technical Field
The invention relates to the field of optical measurement, in particular to a central pixel high-precision identification optical measurement system and method.
Background
The principle of laser triangulation is that a beam of laser is focused on the surface of an object to be measured at a certain angle, then laser spots on the surface of the object are imaged from another angle, the heights of laser irradiation points on the surface of the object are different, the angles of scattered or reflected light rays are also different, the positions of spot images are measured by a CCD photoelectric detector, and the angles of principal rays can be calculated, so that the positions of the laser irradiation points on the surface of the object are calculated. When the object moves along the laser line, the measurement result will change, thereby realizing the measurement of the displacement or distance of the object by the laser.
In the traditional laser triangulation ranging or displacement method, very high requirements are put forth on the design of a laser light source and an optical system, the measurement precision of the whole system is often improved by adding complex optical system auxiliary design, the cost is high, the consistency is difficult to maintain in the production and manufacturing process, and the proposed concept and method are difficult to realize batch production; and the components forming the optical system structure are too many, the design precision requirement is harsh, the design is complex, the debugging process of the whole system is complex, and the method is only suitable for a laboratory stage.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a central pixel high-precision identification light measurement system and a method, which solve the problem of light triangulation precision from the system angle by controlling the measurement key parameters, and have the advantages of low cost and high measurement precision.
In order to achieve the above objective, the present invention provides a central pixel high-precision identification light measurement system, which comprises a light emitting device, a diaphragm, a bandpass filter, a measured object, a narrowband filter, a focusing device, an image sensor and a signal processing device; the light emitting device emits light to the object to be detected to form a first light path, and the image sensor receives reflected light passing through the object to be detected along a second light path direction; the light emitting device, the diaphragm, the band-pass filter and the object to be measured are sequentially arranged along the first light path; the object to be measured, the band-pass filter, the narrowband filter, the focusing device and the image sensor are sequentially arranged along the second light path; the light emitting device comprises a light emitter, a light driving circuit and a light power control circuit, wherein the light driving circuit and the light power control circuit are connected with the light emitter; the image sensor is connected with the signal processing device.
Preferably, the light emitter comprises a light emitting diode, and the positive electrode of the light emitting diode is connected with a power input end; the light emitting diode adopts a laser diode or an LED diode.
The optical drive circuit includes:
the collector electrode of the first triode is connected with the cathode of the light emitting diode;
the first resistor is connected between the emitter of the first triode and a grounding end;
the first end of the second resistor is connected with the power input end, and the second end of the second resistor is connected with the base electrode of the first triode;
the collector electrode of the second triode is connected with the second end of the second resistor, and the emitter electrode of the second triode is connected with the grounding end;
the cathode of the light-operated diode is connected with the power input end, and the anode of the light-operated diode is connected with the base electrode of the second triode; and
and the first end of the third resistor is connected with the anode of the light-operated diode and the base electrode of the second triode, and the second end of the third resistor is connected with the grounding end.
Preferably, the optical power control circuit includes:
the collector electrode of the third triode is connected with the negative electrode of the light emitting diode, and the emitter electrode of the third triode is connected with the grounding end; and
and the first end of the fourth resistor is connected with a signal input end, and the second end of the fourth resistor is connected with the base electrode of the third triode.
Preferably, the optical power control circuit further includes a filter circuit, the filter circuit includes two filter capacitors connected in parallel, and the filter circuit is connected between the power input terminal and the ground terminal.
Preferably, the focusing device adopts a convex lens or a CCD lens.
Preferably, the image sensor employs a linear CMOS photosensitive device.
Preferably, the diaphragm includes a substrate and a diaphragm aperture formed in the substrate, and a center position of the diaphragm aperture corresponds to an optical axis position of the first optical path.
The invention relates to a center pixel high-precision identification light measurement method based on a center pixel high-precision identification light measurement system, which comprises the following steps:
s1: causing the light emitters to operate in a linear region by adjustment of the optical power control circuit;
s2: controlling the light emitter to emit the light to the object to be measured;
s3: the image sensor collects an optical signal formed by the reflected light and transmits the optical signal to the signal processing device;
s4: the signal processing device processes the electric signal through a pixel center algorithm to obtain the position of a pixel center of the current optical signal in the image sensor;
s5: calculating and obtaining a distance L between the measured object and the focusing device according to a triangulation formula, wherein the triangulation formula is as follows:
wherein f represents the distance from the focusing device to the image sensor; d represents the distance between the center of the light emitter and the center of the focusing device; alpha represents an included angle between the first optical path and the second optical path; x represents the position of the pixel center of the current light signal in the image sensor; m represents the center position of the image sensor; n represents the size of a single pixel; b represents the angle between the end face of the image sensor and the end face of the focusing device.
Preferably, the pixel center algorithm is selected from one of a general gray center algorithm, a square gray center algorithm, and a return difference gray center algorithm;
the general gray center algorithm obtains the position of the pixel center of the current light signal in the image sensor by a formula (2):
wherein X is i An x-axis coordinate value representing an i-th pixel; y is Y i A level value corresponding to the i-th pixel; s represents the dot taking start position of the pixel, and F represents the dot taking end position of the pixel;
the square gray matter center algorithm obtains the position of the pixel center of the current light signal in the image sensor by a formula (3):
the return difference gray matter center algorithm comprises the following steps:
s41: setting a desired threshold range;
s42: setting a return difference value to expand the expected threshold range to obtain a return difference threshold range, wherein the minimum value of the return difference threshold range is the minimum value of the expected threshold range minus the return difference value, and the maximum value of the return difference threshold range is the maximum value of the expected threshold range plus the return difference value;
s43: selecting a point taking start position of the pixel and a point taking end position of the pixel;
s44: judging whether the point taking start position of the pixel and the point taking end position of the pixel are within the return difference threshold range or not; calculating a position of a pixel center in the image sensor, where a current light signal is obtained, using the formula (3); if not, the process returns to step S43.
Preferably, in the step S1: and the voltage and the current of the light emitter are respectively in linear relation with the light intensity through adjusting the resistance value of the third resistor in the light driving circuit.
The invention adopts the technical proposal, which has the following beneficial effects:
the matching of the band-pass filter and the narrow-band filter effectively prevents the ambient light and the light of other wavelength bands from entering the image sensor, and improves the sensitivity of the image sensor. The light driving circuit is used for driving the light emitter to work. The optical power control circuit is used for controlling the power of the light emitters. The light emitters may be operated in the linear region by adjustment of the optical power control circuit. The signal processing device is used for processing and calculating the acquired signals of the image sensor. The adoption of the pixel center algorithm enables the center pixel high-precision identification light measurement method to calculate the displacement or distance of the measured object more accurately. The cooperation of the optical drive circuit, the optical power control circuit and the pixel center algorithm realizes that a more accurate measurement result can be obtained on the basis of a simpler system structure, and has the advantages of low cost, high measurement precision, convenience in operation and easiness in popularization.
Drawings
FIG. 1 is a schematic diagram of a central pixel high-precision identification light measurement system according to an embodiment of the present invention;
FIG. 2 is a schematic circuit diagram of an optical driving circuit according to an embodiment of the present invention;
FIG. 3 is a schematic circuit diagram of an optical power control circuit according to an embodiment of the present invention;
FIG. 4 is an image view of an image sensor according to an embodiment of the present invention;
FIG. 5 is a schematic diagram of a pixel-center algorithm according to an embodiment of the present invention;
FIG. 6 is a schematic diagram of a triangulation formula according to an embodiment of the present invention;
fig. 7 is a flowchart of a method for measuring a center pixel high-precision recognition light according to an embodiment of the present invention.
Detailed Description
The following description of the preferred embodiments of the present invention will be given with reference to fig. 1 to 7, so that the functions and features of the present invention can be better understood.
Referring to fig. 1, a high-precision identification light measurement system for a center pixel according to an embodiment of the present invention includes a light emitting device 1, a diaphragm 2, a bandpass filter 3, a measured object 4, a narrowband filter 5, a focusing device 6, an image sensor 7, and a signal processing device 8; the light emitting device 1 emits light to the object 4 to be measured to form a first light path, and the image sensor 7 receives the reflected light passing through the object 4 along a second light path direction; the light emitting device 1, the diaphragm 2, the band-pass filter 3 and the measured object 4 are sequentially arranged along a first light path; the object 4 to be measured, the band-pass filter 3, the narrow-band filter 5, the focusing device 6 and the image sensor 7 are sequentially arranged along a second light path; the light emitting device 1 includes a light emitter and a light driving circuit 11 and a light power control circuit 12 connected to the light emitter; the image sensor 7 is connected to a signal processing means 8.
In this embodiment, the focusing device 6 is a convex lens or a CCD lens. The image sensor 7 employs a linear CMOS photosensitive device. The diaphragm 2 includes a substrate and a diaphragm aperture formed in the substrate, the center position of the diaphragm aperture corresponding to the optical axis position of the first optical path.
Referring to fig. 2, the light emitter includes a light emitting diode DL, the light emitting diode DL is a laser diode or an LED diode, and the light driving circuit 11 includes: a first triode Q1, a first resistor R1, a second resistor R2, a second triode Q2, a light control diode D1 and a third resistor R3. Wherein, the positive electrode of the light emitting diode DL is connected with a power input end V; the collector electrode of the first triode Q1 is connected with the cathode of the light-emitting diode DL; the first resistor R1 is connected between the emitter of the first triode Q1 and a ground GND; the first end of the second resistor R2 is connected with the power input end V, and the second end of the second resistor R2 is connected with the base electrode of the light emitting diode DL; the collector of the second triode Q2 is connected with the second end of the second resistor R2, and the emitter of the second triode Q2 is connected with the ground end GND; the cathode of the light-operated diode D1 is connected with the power input end V, and the anode of the light-operated diode D1 is connected with the base electrode of the second triode Q2; the first end of the third resistor R3 is connected with the anode of the light-operated diode D1 and the base electrode of the second triode Q2, and the second end of the third resistor R3 is connected with the grounding end GND.
Referring to fig. 3, the optical power control circuit 12 includes: a third triode Q3, a fourth resistor R4 and a filter circuit. The collector of the third triode Q3 is connected with the anode of the light emitting diode DL, and the emitter of the third triode Q3 is connected with the ground end GND; the first end of the fourth resistor R4 is connected to a signal input terminal IN, and the second end of the fourth resistor R4 is connected to the base of the third transistor Q3. The filter circuit comprises two filter capacitors C which are connected in parallel, and the filter circuit is connected between the power input end V and the ground end GND.
Referring to fig. 1, the working principle of the center pixel high-precision identification light measurement system of the present embodiment is as follows:
after light is generated from the light emitting device 1, the light spot is obviously reduced through the limiting action of the diaphragm 2, diffuse reflection is generated after the light meets the object 4, the light reflected by diffuse reflection reaches the focusing device 6 through the band-pass filter 3 and the narrow-band filter 5, the light spot falls on a certain area of the image sensor 7 through the focusing action of the focusing device 6, a photoelectric effect is generated on the image sensor 7, a specific electric signal is output by the image sensor 7, and the position information of the object 4 is calculated after the signal processing and calculation of the signal processing device 8.
The band-pass filter 3 is made of a colored transparent material and is limited to only allow light rays larger than the wavelength of the light to pass through; the narrow-band filter 5 limits the wavelength of the incident light to a specific area, and only allows the light rays within the area to pass through; the combined use of the two filters effectively prevents the ambient light and the light of other wavelength bands from entering the image sensor 7, and improves the sensitivity of the image sensor 7.
In the present embodiment, the setting of the diaphragm 2 includes the following three elements: 1. the direction of the aperture of the diaphragm 2 is perpendicular to the direction of the image sensor 7, so that the light spot number of the image sensor 7 is effectively reduced; 2. the aperture area of the diaphragm 2 is arranged at the center of the light spot as much as possible so as to keep the light coming out of the diaphragm 2 uniformly distributed as much as possible; 3. the minimum width of the aperture of the narrow slit of the diaphragm 2 is required to meet the minimum slit which does not generate diffraction phenomenon after light can be transmitted, and the energy of the light spot after projection is required to meet the requirement of receiving sensitivity of the receiving tube. The light is parallel light, and the size of the spot on the object 4 is equal to the width of the aperture of the diaphragm 2, so that when the distance is long, the light intensity is required to be large, and the aperture width of the corresponding diaphragm 2 becomes large.
The focusing device 6 focuses the light reflected back to the imaging area of the image sensor 7, and when a lens is used for the focusing device 6, the lens type is not limited to a biconvex lens or a plano-convex lens. Further improvement, the single convex lens can be replaced by an adjustable CCD lens, so that a better light focusing effect is realized, and the influence of the light spot size on a measurement result is reduced.
The image sensor 7 is a linear CMOS photosensitive device, converts a received optical signal into an electrical signal, and the center of the photosensitive area of the image sensor 7 and the center of the position of light emission are kept in the same plane when the structure is designed; the received signal processing is the core of the system.
In addition, the size of the gap of the diaphragm 2 is controlled, so that the image sensor 7 can image images with different shapes, the smaller the gap of the diaphragm 2 is, the smaller the top shape of the imaging area of the image sensor 7 is, and the calculation and judgment result of the pixel center is more accurate; the size of the aperture 2 gap is preferably the smallest gap that does not produce diffraction of light waves.
When the focusing means 6 employs a lens, the shape of the lens is not limited to a biconvex lens or a plano-convex lens, or a combination lens is used to produce a better spot imaging effect.
This may be applicable when the image sensor 7 is a single linear or multi-linear CMOS device.
The wavelength of light emission is not limited to 650nm, and is also applicable to processing results of other wavelength bands.
The signal processing device 8 may employ, but is not limited to, a stand-alone ADC module or a single-chip integrated ADC module.
The center pixel high-precision identification light measurement system of the embodiment is not limited to distance measurement products, and is also applicable to displacement measurement products.
Referring to fig. 4, after the optical signal received by the image sensor 7 is converted, a level signal varying with the coordinate position of the pixel is presented, and according to the resolution of the CMOS photosensitive area of the image sensor 7, the converted level signal is distributed in a shape of a "several", and the larger the light spot is, the more pixels fall into the "several" shape; in general, there are tens of light spot points in the shape of a Chinese character 'ji', and the geometric center position of the light spot needs to be found according to the level signal of the pattern, and the geometric center position of the light spot has a direct relation with the calculation result of the last measurement.
Referring to fig. 6 and 7, a method for measuring a center pixel of a center pixel high-precision recognition light measurement system according to the present embodiment includes the steps of:
s1: the light emitters are operated in the linear region by adjustment of the optical power control circuit 12.
In this embodiment, the voltage and current of the light emitter are respectively linearly related to the light intensity by adjusting the resistance value of the third resistor R3 in the optical power control circuit 12.
S2: the light emitter is controlled to emit light to the object 4 to be measured.
The intensity design of the light not only meets the safety performance, but also has a certain proper intensity, so that the reflected light is not saturated by overvoltage after being received by the image sensor 7, and the received signal of the image sensor 7 is not too weak because the light intensity is too weak.
S3: the image sensor 7 collects an optical signal formed by the reflected light and transmits the optical signal to the signal processing device 8.
S4: the signal processing means 8 processes the electrical signal by a pixel center algorithm to obtain the position of a pixel center of the current optical signal in the image sensor 7.
In this embodiment, the pixel center algorithm is selected from one of a general gray center algorithm, a square gray center algorithm, and a return difference gray center algorithm. A schematic diagram of the pixel-center algorithm can be seen in fig. 5, where x represents the coordinate position of the pixel and y represents the level value of the corresponding coordinate of the pixel.
Wherein, the general gray matter center algorithm obtains the position of the pixel center of the current light signal in the image sensor 7 by a formula (2):
wherein X is i An x-axis coordinate value representing an i-th pixel; y is Y i A level value corresponding to the i-th pixel; s denotes the fetch start position of the pixel, and F denotes the fetch end position of the pixel.
The result fluctuation obtained by the general gray matter center algorithm on the waveform with the sharp fluctuation of the image is larger, and the influence on the measurement repetition precision is larger.
The square gray matter center algorithm obtains the position of the pixel center of the current light signal in the image sensor 7 by a formula (3):
the square gray matter center algorithm can effectively reduce the influence of up-and-down fluctuation of the image on the measurement repetition precision.
Wherein, the return difference gray matter center algorithm comprises the following steps:
s41: setting a desired threshold range;
s42: setting a return difference value to expand the expected threshold range to obtain a return difference threshold range, wherein the minimum value of the return difference threshold range is the minimum value of the expected threshold range minus the return difference value, and the maximum value of the return difference threshold range is the maximum value of the expected threshold range plus the return difference value;
s43: selecting a point taking start position of a pixel and a point taking end position of the pixel;
s43: judging whether the point taking start position of the pixel and the point taking end position of the pixel are within a return difference threshold range or not; as in the case, the position of the pixel center in the image sensor 7 of the current optical signal is obtained by calculation using the formula (3); if not, the process returns to step S43.
For example: the initial point of the return difference gray matter center algorithm can be started from the point 0, the end point is ended to the last pixel point, and after the background noise is removed, the initial point is started from the point S, and the point F is ended; the algorithm return difference gray matter center algorithm process of the return difference method is similar to that of the square gray matter center algorithm, when a starting point is taken, a threshold value is preset, for example, 1000 is adopted, the corresponding starting point is S1 and F1, a return difference value is set before calculation, the assumption is 20, the return difference threshold value range is 980-1020, whether the value point is in the return difference threshold value range or not is judged firstly, and if the corresponding pixel is in the return difference threshold value range, the judgment of the pixel center is carried out by utilizing a formula (3); if the value of the pixel exceeds this return difference threshold range, the determination of the starting point will be resumed.
The setting of the return difference value is not limited to 20 in the above example, and the actual return difference value is related to the whole system requirement. The return difference gray matter center algorithm can greatly reduce the number of the sampling points of the whole system and improve the calculation efficiency of the system.
S5: the distance L between the measured object 4 and the focusing device 6 is calculated according to a triangulation formula, wherein the triangulation formula is as follows:
where f represents the distance of the focusing means 6 to the image sensor 7; d represents the distance between the center of the light emitter and the center of the focusing means 6; alpha represents an included angle between the first light path and the second light path; x represents the position of the pixel center of the current light signal in the image sensor 7; m represents the center position of the image sensor 7; n represents the size of a single pixel; b denotes the angle between the end face of the image sensor 7 and the end face of the focusing means 6.
The present invention has been described in detail with reference to the embodiments of the drawings, and those skilled in the art can make various modifications to the invention based on the above description. Accordingly, certain details of the illustrated embodiments are not to be taken as limiting the invention, which is defined by the appended claims.
Claims (9)
1. The high-precision identification light measurement system for the center pixel is characterized by comprising a light emitting device, a diaphragm, a band-pass filter, a measured object, a narrow-band filter, a focusing device, an image sensor and a signal processing device; the light emitting device emits light to the object to be detected to form a first light path, and the image sensor receives reflected light passing through the object to be detected along a second light path direction; the light emitting device, the diaphragm, the band-pass filter and the object to be measured are sequentially arranged along the first light path; the object to be measured, the band-pass filter, the narrowband filter, the focusing device and the image sensor are sequentially arranged along the second light path; the light emitting device comprises a light emitter, a light driving circuit and a light power control circuit, wherein the light driving circuit and the light power control circuit are connected with the light emitter; the image sensor is connected with the signal processing device;
the light emitter comprises a light emitting diode, and the positive electrode of the light emitting diode is connected with a power input end;
the optical drive circuit includes:
the collector electrode of the first triode is connected with the cathode of the light emitting diode;
the first resistor is connected between the emitter of the first triode and a grounding end;
the first end of the second resistor is connected with the power input end, and the second end of the second resistor is connected with the base electrode of the first triode;
the collector electrode of the second triode is connected with the second end of the second resistor, and the emitter electrode of the second triode is connected with the grounding end;
the cathode of the light-operated diode is connected with the power input end, and the anode of the light-operated diode is connected with the base electrode of the second triode; and
the first end of the third resistor is connected with the anode of the light-operated diode and the base electrode of the second triode, and the second end of the third resistor is connected with the grounding end;
the optical power control circuit includes:
the collector electrode of the third triode is connected with the negative electrode of the light emitting diode, and the emitter electrode of the third triode is connected with the grounding end; and
and the first end of the fourth resistor is connected with a signal input end, and the second end of the fourth resistor is connected with the base electrode of the third triode.
2. The center-pixel high-precision identification light measurement system according to claim 1, wherein the light emitting diode is a laser diode or an LED diode.
3. The high-precision identification light measurement system according to claim 1, wherein the light power control circuit further comprises a filter circuit, the filter circuit comprises two filter capacitors connected in parallel, and the filter circuit is connected between the power input terminal and the ground terminal.
4. A central pixel high precision identification light measurement system according to any one of claims 1-3, wherein the focusing means employs a convex lens or a CCD lens.
5. The center-pixel high-precision identification light measurement system according to claim 4, wherein the image sensor employs a linear CMOS photosensitive device.
6. The high-precision identification light measurement system according to claim 4, wherein the diaphragm comprises a substrate and a diaphragm aperture formed in the substrate, the central position of the diaphragm aperture corresponding to the optical axis position of the first optical path.
7. A center pixel high-precision recognition light measurement method based on the center pixel high-precision recognition light measurement system of claim 3, comprising the steps of:
s1: causing the light emitters to operate in a linear region by adjustment of the optical power control circuit;
s2: controlling the light emitter to emit the light to the object to be measured;
s3: the image sensor collects optical signals formed by the reflected light, converts the optical signals into electric signals and then transmits the electric signals to the signal processing device;
s4: the signal processing device processes the electric signal through a pixel center algorithm to obtain the position of a pixel center of the current optical signal in the image sensor;
s5: calculating and obtaining a distance L between the measured object and the focusing device according to a triangulation formula, wherein the triangulation formula is as follows:
wherein f represents the distance from the focusing device to the image sensor; d represents the distance between the center of the light emitter and the center of the focusing device; alpha represents an included angle between the first optical path and the second optical path; x represents the position of the pixel center of the current light signal in the image sensor; m represents the center position of the image sensor; n represents the size of a single pixel; b represents the angle between the end face of the image sensor and the end face of the focusing device.
8. The method of claim 7, wherein the pixel-centric algorithm is selected from one of a general gray-matter-centric algorithm, a square gray-matter-centric algorithm, and a return difference gray-matter-centric algorithm;
the general gray center algorithm obtains the position of the pixel center of the current light signal in the image sensor by a formula (2):
wherein X is i An x-axis coordinate value representing an i-th pixel; y is Y i A level value corresponding to the i-th pixel; s represents the dot taking start position of the pixel, and F represents the dot taking end position of the pixel;
the square gray matter center algorithm obtains the position of the pixel center of the current light signal in the image sensor by a formula (3):
the return difference gray matter center algorithm comprises the following steps:
s41: setting a desired threshold range;
s42: setting a return difference value to expand the expected threshold range to obtain a return difference threshold range, wherein the minimum value of the return difference threshold range is the minimum value of the expected threshold range minus the return difference value, and the maximum value of the return difference threshold range is the maximum value of the expected threshold range plus the return difference value;
s43: selecting a point taking start position of the pixel and a point taking end position of the pixel;
s43: judging whether the point taking start position of the pixel and the point taking end position of the pixel are within the return difference threshold range or not; calculating a position of a pixel center in the image sensor, where a current light signal is obtained, using the formula (3); if not, the process returns to step S43.
9. The method for measuring the high-precision identification light of the center pixel according to claim 8, wherein in the step S1: and the voltage and the current of the light emitter are respectively in linear relation with the light intensity by adjusting the resistance value of the third resistor in the light driving circuit.
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| CN201810027282.2A CN108169757B (en) | 2018-01-11 | 2018-01-11 | High-precision identification light measurement system and method for central pixel |
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| CN108922398B (en) * | 2018-07-26 | 2021-06-22 | 维沃移动通信有限公司 | Mobile terminal |
| CN111722243B (en) * | 2020-06-28 | 2024-05-28 | 上海兰宝传感科技股份有限公司 | Temperature compensation ranging method based on low-temperature drift output of laser triangulation system |
| CN112198521A (en) * | 2020-09-29 | 2021-01-08 | 上海兰宝传感科技股份有限公司 | Method for improving triangular distance measurement precision |
| CN114460594B (en) * | 2022-04-14 | 2022-06-14 | 宜科(天津)电子有限公司 | Image denoising method based on triangular distance measurement |
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| CN108169757A (en) * | 2018-01-11 | 2018-06-15 | 上海兰宝传感科技股份有限公司 | Center pixel high-precision identification light measurement system and method |
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| CN105136672A (en) * | 2015-04-23 | 2015-12-09 | 天津大学 | Area array emission light position triangle wave frequency coding imaging light measuring system |
| CN106441110A (en) * | 2016-09-23 | 2017-02-22 | 西安电子科技大学 | High precision laser displacement sensor system based on CMOS |
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