Laser triangulation method, device, equipment and storage medium

Abstract

Embodiments of the present disclosure disclose a laser triangulation method, device, equipment and storage medium, wherein the method comprises: in the case of emitting a light pulse, in response to detecting a first photon, determining the number of first photons detected by each detection unit in a detection unit array; wherein the first photons comprise photons of ambient light and photons of the light pulse reflected by a target to be measured; in the case of not emitting the light pulse, in response to detecting a second photon, counting down based on the number of first photons detected by a corresponding detection unit to obtain a photon counting result of the detection unit array; wherein the second photons comprise photons of ambient light; and determining the position of the target to be measured based on the photon counting result, so as to reduce the influence of ambient light on the ranging result in an optimal manner.

Description

Technical Field

[0001] This disclosure relates to, but is not limited to, the field of ranging, and particularly to a laser triangulation ranging method, apparatus, device, and storage medium. Background Technology

[0002] Distance measurement is typically achieved using photon time-of-flight (TOF) ranging. This method involves emitting light pulses from a light pulse emitter (such as a laser emitter). These pulses illuminate the target and are diffusely reflected back to a photon detector. A timer records the start time of the emitted light pulse and the end time when the photon detector detects the reflected photon, thus determining the photon flight time. The distance to the target is then calculated based on the relationship between the speed of light, time, and distance. In practical applications, multiple light pulses are emitted to generate a large number of photon flight events. The number of events corresponding to the photon flight time is then statistically analyzed to determine the photon flight time reflecting the target's distance, and finally, the target's position is determined based on the photon flight time.

[0003] However, because photon detectors also detect ambient light photons during the photon detection process, the method of determining the target position based on photon time-of-flight statistical counting has a relatively large error. Therefore, finding a better way to reduce ambient light interference during ranging is an urgent problem to be solved. Summary of the Invention

[0004] In view of this, the present disclosure aims to provide a laser triangulation method, apparatus, device, and storage medium.

[0005] In a first aspect, embodiments of this disclosure provide a laser triangulation ranging method, the method comprising:

[0006] When a light pulse is emitted, in response to the detection of a first photon, the number of first photons detected by each detection unit in the detection unit array is determined; wherein, the first photon includes photons of the light pulse reflected by the target and photons of ambient light;

[0007] Without emitting the light pulse, in response to the detection of a second photon, a count is performed by decreasing the number of first photons detected by the corresponding detection unit to obtain the photon count result of the detection unit array; wherein, the second photon includes photons of ambient light;

[0008] Based on the photon counting results, the position of the target to be measured is determined.

[0009] In some embodiments, the step of obtaining the photon count result of the detection unit array by decrementing the count based on the number of first photons detected by the corresponding detection unit in response to the detection of a second photon when the light pulse is not emitted includes:

[0010] If no light pulse is emitted for a second preset time period, in response to the detection of the second photon, the photon count of the detection unit array is obtained by counting down based on the number of first photons detected by the corresponding detection unit;

[0011] Wherein, the corresponding detection unit is the detection unit that detects the second photon; the number of the first photons detected by the corresponding detection unit is recorded based on multiple light pulses continuously emitted within a first preset time period, taking the photons detected by the corresponding detection unit or its neighboring detection unit as the first photons, and counting them incrementally; the positional interval between the corresponding detection unit and any of the neighboring detection units is less than a preset distance threshold; the first preset time period and the second preset time period are time intervals of the same duration.

[0012] In some embodiments, the step of obtaining the photon count result of the detection unit array by decrementing the count based on the number of first photons detected by the corresponding detection unit in response to the detection of a second photon when the light pulse is not emitted includes:

[0013] Obtain time information of light pulse emission within a third preset time period; wherein, the time information includes the pulse period during which the light pulse is emitted and the gap period during which the light pulse is not emitted, and at least one pulse period and at least one gap period alternate;

[0014] If no light pulse is emitted during any of the aforementioned gap periods, in response to the detection of the second photon, a count is performed by decreasing the number of the first photons detected by the corresponding detection unit to obtain the photon count result of the detection unit array.

[0015] Wherein, the corresponding detection unit is the detection unit that detects the second photon. The number of first photons detected by the corresponding detection unit is obtained by taking the photons detected by the corresponding detection unit or the neighboring detection unit of the corresponding detection unit during the pulse period as the first photons and counting them incrementally. The positional interval between the corresponding detection unit and any of the neighboring detection units is less than a preset distance threshold.

[0016] In some embodiments, when no light pulse is emitted during each of the gap periods, in response to the detection of the second photon, a count is performed decrementally based on the number of first photons detected by the corresponding detection unit to obtain the photon count result of the detection unit array, including:

[0017] Based on the number of pulse periods and the number of gap periods in the time information, the first photon reduction of the ambient light is determined; wherein, the first photon reduction is positively correlated with the ratio between the number of pulse periods and the number of gap periods;

[0018] If no light pulse is emitted during each of the aforementioned gap periods, in response to the detection of the second photon, the photon count of the detection unit array is obtained by decreasing the count based on the number of first photons detected by the corresponding detection unit according to the amount of decrease in the first photon count.

[0019] In some embodiments, the step of decreasing the count based on the number of first photons detected by the corresponding detection unit to obtain the photon count result of the detection unit array according to the first photon reduction amount includes:

[0020] The first photon reduction is distributed to the corresponding detection unit and / or neighboring detection units in an equal or non-equal manner to obtain the second photon reduction of the corresponding detection unit and / or neighboring detection units respectively.

[0021] For each of the corresponding detection units and / or neighboring detection units, based on the number of first photons detected by the corresponding detection unit, the decrease in the number of second photons corresponding to the detection unit is counted by subtracting the count to obtain the photon count result of the detection unit array.

[0022] In some embodiments, distributing the first photon reduction amount non-uniformly to the corresponding detection unit and / or neighboring detection units to obtain the second photon reduction amount for each of the corresponding detection unit and / or neighboring detection units includes:

[0023] The first photon reduction amount is allocated to the corresponding detection unit and / or neighboring detection units according to different preset weights, so as to obtain the second photon reduction amount of the corresponding detection unit and / or neighboring detection units respectively.

[0024] In some embodiments, determining the position of the target based on the photon counting result includes:

[0025] Based on the photon counting results, a histogram is generated;

[0026] Determine the target detection unit corresponding to the highest peak in the histogram;

[0027] The location of the target to be detected is determined based on the target detection unit.

[0028] In some embodiments, determining the position of the target to be detected based on the target detection unit includes:

[0029] Based on the position of the target detection unit in the detection unit array, and combined with the principle of laser triangulation, the position of the target to be measured is determined.

[0030] Secondly, embodiments of this disclosure provide a laser triangulation ranging device, the device comprising:

[0031] A response module is configured to respond to the detection of a first photon when a light pulse is emitted, and to respond to the detection of a second photon when the light pulse is not emitted; wherein the first photon includes photons of the light pulse reflected by the target and photons of ambient light, and the second photon includes photons of ambient light;

[0032] A counting module is used to determine the number of first photons detected by each detection unit in the detection unit array in response to the detection of a first photon when a light pulse is emitted; and to perform a count by decrementing based on the number of first photons detected by the corresponding detection unit in response to the detection of a second photon when no light pulse is emitted, so as to obtain the photon count result of the detection unit array.

[0033] The data processing module is used to determine the position of the target to be measured based on the photon counting results.

[0034] In some embodiments, the counting module is configured to, in response to the detection of the second photon, perform a count based on the number of first photons detected by the corresponding detection unit when no light pulse is emitted continuously for a second preset time period, thereby obtaining the photon count result of the detection unit array.

[0035] Wherein, the corresponding detection unit is the detection unit that detects the second photon; the number of the first photons detected by the corresponding detection unit is recorded based on multiple light pulses continuously emitted within a first preset time period, taking the photons detected by the corresponding detection unit or its neighboring detection unit as the first photons, and counting them incrementally; the positional interval between the corresponding detection unit and any of the neighboring detection units is less than a preset distance threshold; the first preset time period and the second preset time period are time intervals of the same duration.

[0036] In some embodiments, the counting module is used to acquire time information of light pulse emission within a third preset duration; wherein, the time information includes a pulse period during which the light pulse is emitted and a gap period during which the light pulse is not emitted, and at least one pulse period and at least one gap period alternate; in the case that no light pulse is emitted during each of the gap periods, in response to the detection of the second photon, the counting is performed by decrementing based on the number of first photons detected by the corresponding detection unit to obtain the photon counting result of the detection unit array;

[0037] Wherein, the corresponding detection unit is the detection unit that detects the second photon; the number of the first photons detected by the corresponding detection unit is obtained by taking the photons detected by the corresponding detection unit or the neighboring detection unit of the corresponding detection unit during the pulse period as the first photons and counting them incrementally; the positional interval between the corresponding detection unit and any of the neighboring detection units is less than a preset distance threshold.

[0038] In some embodiments, the counting module is configured to determine a first photon reduction amount of the ambient light based on the number of pulse periods and the number of gap periods in the time information; wherein the first photon reduction amount is positively correlated with the ratio between the number of pulse periods and the number of gap periods; in the case that no light pulse is emitted during each of the gap periods, in response to the detection of the second photon, the counting is performed by decreasing the count based on the number of first photons detected by the corresponding detection unit according to the first photon reduction amount, to obtain the photon counting result of the detection unit array.

[0039] In some embodiments, the counting module is configured to distribute the first photon reduction amount to the corresponding detection unit and / or neighboring detection units in an equal or non-equal manner, respectively, to obtain the second photon reduction amount of the corresponding detection unit and / or neighboring detection units; for each detection unit in the corresponding detection unit and / or neighboring detection units, based on the number of first photons detected by the corresponding detection unit, the second photon reduction amount corresponding to the detection unit is counted by decreasing the count to obtain the photon counting result of the detection unit array.

[0040] In some embodiments, the counting module is used to allocate the first photon reduction amount to the corresponding detection unit and / or neighboring detection units according to different preset weights, so as to obtain the second photon reduction amount of the corresponding detection unit and / or neighboring detection units respectively.

[0041] In some embodiments, the data processing module is configured to generate a histogram based on the photon counting results; determine the target detection unit corresponding to the highest peak in the histogram; and determine the position of the target to be measured based on the target detection unit.

[0042] In some embodiments, the data processing module is used to determine the position of the target to be measured based on the position of the target detection unit in the detection unit array and in combination with the principle of laser triangulation.

[0043] Thirdly, embodiments of this disclosure provide a laser triangulation ranging device, comprising:

[0044] A single-photon avalanche diode array includes multiple single-photon avalanche diodes, wherein the single-photon avalanche diodes are used to detect a first photon in response to the emission of a light pulse, and to detect a second photon in response to the absence of the light pulse; wherein the first photon includes photons of the light pulse reflected by the target and photons of ambient light, and the second photon includes photons of ambient light;

[0045] The counter array includes multiple counters, each corresponding to one of the single-photon avalanche diodes; the counters are used to determine the number of first photons detected by each single-photon avalanche diode in the single-photon avalanche diode array when a light pulse is emitted and the single-photon avalanche diode array responds to detecting a first photon; and to count the photons of the single-photon avalanche diode array by decrementing the count based on the number of first photons detected by the corresponding single-photon avalanche diode when no light pulse is emitted and the single-photon avalanche diode array responds to detecting a second photon, thereby obtaining the photon count result of the single-photon avalanche diode array;

[0046] A central processing unit is used to determine the position of the target under test based on the photon counting results.

[0047] Fourthly, embodiments of this disclosure provide a storage medium having a computer program stored thereon, which, when executed by a processor, implements the method described in the first aspect.

[0048] The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects:

[0049] On the one hand, this application eliminates the influence of ambient light by subtracting the photon count of ambient light during the photon counting stage, reducing the interference of ambient light on the ranging results and improving the signal-to-noise ratio. On the other hand, related technologies separately count and store the mixed photon count of ambient light and target reflected light, as well as the photon count of ambient light. The data from these two photon counts needs to be stored twice, requiring a large amount of storage space. However, the embodiments of this disclosure count and store the mixed photon count of ambient light and target reflected light detected by each detection unit when a light pulse is emitted. Based on this, when no light pulse is emitted, the photons of ambient light are detected in real time, and the count is decremented in real time based on the mixed photon count of ambient light and target reflected light corresponding to the detection unit. This eliminates the influence of the photon count of ambient light and eliminates the need to store the photon count data of ambient light, greatly reducing memory usage and improving the real-time performance of ranging. Furthermore, in related technologies, the mixed photon count of ambient light and target reflected light is subtracted from the photon count of ambient light using a subtractor, which requires a large amount of computation on the binary digital encoding of the two photon counts. However, the embodiments of this disclosure are based on the photons detected by ambient light and the mixed photon count of ambient light and target reflected light is used for decrementing the count, which can avoid computation on the binary digital encoding, thereby reducing the computational load and reducing the requirements for hardware resources.

[0050] Furthermore, under strong ambient light conditions, the light spot reflecting the distance to the target detected by laser triangulation is affected by the ambient light photon count, making the light spot appearing in the detector array weak, indistinct, and scattered. This makes it difficult to determine the center position of the light spot, and consequently, difficult to calculate the true distance to the target based on the center position and the principle of laser triangulation. This application is based on the principle of laser triangulation. By reducing the ambient light photon count as described above, the intensity and dispersion of the light spot formed by the ambient light photon count on the detector array can be reduced. This makes the light spot formed by the light pulse reflected from the target on the detector array more obvious and concentrated, facilitating accurate positioning of the center position and improving measurement accuracy and efficiency. It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this disclosure. Attached Figure Description

[0051] Figure 1 A flowchart of a laser triangulation ranging method provided in this embodiment of the present disclosure;

[0052] Figure 2 An example diagram of a modulated optical pulse provided in an embodiment of this disclosure;

[0053] Figure 3 A histogram showing the distribution of the number of first photons in a detection unit, provided for embodiments of this disclosure;

[0054] Figure 4 A histogram showing the distribution of photon counting results in a detection unit, provided as an embodiment of this disclosure;

[0055] Figure 5 An example diagram of triangulation provided in this disclosure embodiment;

[0056] Figure 6 An example diagram of a laser triangulation ranging device provided in an embodiment of this disclosure;

[0057] Figure 7 A laser triangulation ranging device is provided as an embodiment of this disclosure. Detailed Implementation

[0058] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0059] To reduce interference from ambient light during ranging, the relevant technology achieves this through the following method: During the measurement period when the light pulse emitter does not send light pulses, the photon detector only detects and counts the photons of ambient light, stores the counting result A in memory A, and generates a histogram A; where histogram A represents the distribution of the counting result A in each time bin. During another measurement period, the light pulse emitter emits laser light towards the target, and the photon detector simultaneously detects and counts the photons of ambient light and the photons of laser light reflected back from the target, stores the counting result B in memory B, and generates a histogram B; where histogram B represents the distribution of the counting result B in each time bin. The counting result B in memory B is subtracted from the counting result A in memory A by a subtractor to obtain the laser photon counting result C after removing ambient light. At the same time, histogram B is subtracted from histogram A to obtain histogram C. The time bin with the highest peak value in histogram C is selected, and the distance S between the light pulse emitter and the target is calculated using the following formula (1):

[0060] S = v*(t / 2); (1)

[0061] Where v represents the speed of light; t represents the time of photon travel, corresponding to the time bin at the highest peak in histogram C.

[0062] In the aforementioned technical solutions, it is assumed that a measurement time period is represented in a histogram as consisting of N time boxes, where each time box represents a time interval of a certain length. If the number of laser emissions within a measurement time period is 255, then the maximum value that the storage space corresponding to each time box in the histogram of two measurements can store is at least 255. For example, in binary encoding storage, the bit width of the storage space corresponding to each time box is at least 8 bits (the maximum output value is 2^8 - 1 = 255), meaning each time box requires at least 8 bits of storage space to store the photon counting results within that time box. Therefore, memory A and memory B each require at least 8 * N bits of storage space, totaling at least 16 * N bits of storage space to store counting results A and B. Furthermore, when the subtractor performs subtraction on counting results B and A, it needs to perform operations on the data in the storage space corresponding to each time box. Since each time box corresponds to 8 bits of data, each time box requires 8 bit operations, placing high demands on hardware resources.

[0063] As can be seen from the above, the solutions in the aforementioned related technologies have the following drawbacks:

[0064] 1. The storage of the ambient light detection count result A (corresponding to memory A) consumes a large amount of memory resources;

[0065] 2. The subtractor performs a subtraction operation between the counting result B and the counting result A to obtain the counting result C. This requires a large number of calculations, places high demands on hardware resources, and the subtractor's calculation time affects the ranging time, resulting in poor efficiency.

[0066] In this regard, the present disclosure provides a laser triangulation ranging method, the execution subject of which can be a laser triangulation ranging device (hereinafter referred to as a ranging device). For example, the laser triangulation ranging method can be executed by a terminal device or a server, or by a ranging device including the aforementioned optical pulse emitter, photon detector, timer, etc. In some possible implementations, the laser triangulation ranging method can be implemented by a processor calling computer-readable instructions stored in memory. The following description uses the ranging device as the execution subject of the laser triangulation ranging method as an example.

[0067] Figure 1 This diagram illustrates a flowchart of a laser triangulation ranging method provided in an embodiment of this disclosure, consisting of... Figure 1 It can be seen that the method includes:

[0068] S11. When emitting a light pulse, in response to detecting a first photon, determine the number of first photons detected by each detection unit in the detection unit array; wherein, the first photon includes photons reflected by the light pulse after passing through the target and photons of ambient light;

[0069] S12. In the absence of emitting the light pulse, in response to the detection of the second photon, a count is performed by decreasing the count based on the number of the first photons detected by the corresponding detection unit to obtain the photon count result of the detection unit array; wherein, the second photon includes photons of ambient light;

[0070] S13. Based on the photon counting results, determine the position of the target to be measured.

[0071] In this embodiment of the disclosure, light pulses can be emitted by a light pulse emitter, which includes a driver and a light source, etc. The light source can be a light-emitting diode (LED), a laser diode (LD), an edge-emitting laser (EEL), a vertical-cavity surface-emitting laser (VCSEL), etc. The light source emits light pulses outward under the driving control of the driver; the light pulses can be laser light, infrared light, ultraviolet light, etc., and this embodiment of the disclosure does not limit them.

[0072] This disclosure embodiment can detect photons using a photon detector, which includes a detection end and optical elements for guiding light propagation. These optical elements can be one or more combinations of lenses, microlens arrays, and mirrors, guiding the light signal to the detection end. The detection end can include a SPAD array composed of multiple single-photon avalanche photodiodes (SPADs). The SPAD pixels in the SPAD array can respond to an incident single photon and output a pulse signal, while a counter outputs a corresponding digital signal. For example, an output signal of "0" indicates that no photon was detected, and an output signal of "1" indicates that a photon was detected.

[0073] Compared to photodiodes used as detection units, such as contact image sensors (CIS) and charge-coupled device (CCD) image sensors, the SPAD used as the detection unit in this disclosure has higher photon detection sensitivity, thereby improving ranging accuracy.

[0074] Among them, the signals that cause photon detectors such as SPADs to output signals that detect photons may be: dark current, ambient light, and light reflected back from the target by light pulses emitted by active light sources; it is understandable that ambient light has a greater impact on photon detection.

[0075] In step S11, the ranging device can determine the scene in which the light pulse is emitted based on the instruction to detect the emitted light pulse; or it can determine the scene in which the light pulse is emitted based on the start time of the emitted light pulse.

[0076] In this embodiment of the present disclosure, when a light pulse is emitted, in response to the photon detector detecting a first photon as described above, the ranging device determines the number of first photons detected by each detection unit in the detection unit array. Specifically, each time a detection unit in the detection unit array detects a first photon, the ranging device increments the count of the first photons corresponding to the detection unit that detected the first photon by 1. It is understood that there is a correspondence between the number of detection units and the number of first photons in this embodiment of the present disclosure.

[0077] In this embodiment of the disclosure, when a first photon is detected, the ranging device can acquire the number of first photons detected by each detection unit in real time; or, after a preset detection period, determine the final number of first photons detected by each detection unit. Since ambient light is detected simultaneously when a light pulse is emitted, the first photon detected in this embodiment of the disclosure includes the photon reflected by the light pulse from the target and the photon of the ambient light.

[0078] In step S12, when no light pulse is emitted, the photon detector, in response to detecting a second photon, performs a decremental count based on the number of first photons detected by the corresponding detection unit to obtain the photon count result of the detection unit array. The corresponding detection unit can be the detection unit that detected the second photon, and the number of first photons detected by the corresponding detection unit can be obtained by incrementing the count using photons detected by the corresponding detection unit or its neighboring detection units as the first photons. The positional distance between the detection unit that detected the second photon (i.e., the corresponding detection unit) and any neighboring detection unit is less than a preset distance threshold.

[0079] It should be noted that if the corresponding detection unit has not detected the first photon before detecting the second photon, then the actual number of first photons detected by the corresponding detection unit is zero. In this case, the number of first photons detected by the neighboring detection units can be used as the number of first photons detected by the corresponding detection unit, and used for the corresponding detection unit to perform a decrementing count when responding to the second photon. If there are multiple neighboring detection units, one of the following can be used as the number of first photons detected by the neighboring detection units: the mean, the maximum, the minimum, or the median. This serves as the basis for the decrementing count.

[0080] Specifically, the number of first photons is stored. The number of first photons detected by the registered detection unit is obtained. Each time the detection unit detects a second photon, it performs a subtraction operation on the number of first photons and updates the result of the subtraction operation in the storage space used to store the number of first photons, thus obtaining the photon count result corresponding to the detection unit. Based on this decrementing counting method, the photon count result of the detection unit array can be obtained, which is the "decrementing count" defined in the embodiments of this disclosure. The decrementing count based on the number of first photons detected by the corresponding detection unit can be a decrementing count of 1 or other preset values, which are not limited in this disclosure.

[0081] Since only ambient light exists in the absence of emitted light pulses, the second photons detected in this embodiment of the present disclosure include photons of ambient light.

[0082] It is understood that, based on the aforementioned decrementing counting operation method, the embodiments of this disclosure can greatly save storage space and eliminate interference from ambient light. Moreover, since the decrementing counting of the embodiments of this disclosure is a one-to-one subtraction operation, rather than a multi-digit subtraction operation, the effect of reducing the amount of computation can be achieved.

[0083] It should be noted that, in some embodiments, step S11 represents the first detection process, such as continuously emitting light pulses within a first preset duration, and determining the number of first photons detected by each detection unit in the detection unit array in response to the detection of a first photon; step S12 represents the second detection process, such as not emitting light pulses within a second preset duration, and counting decreasing based on the number of first photons detected by the corresponding detection unit for each second photon detected, to obtain the photon count result of the detection unit array. Here, the first preset duration and the second preset duration are time intervals of the same length.

[0084] In some embodiments, steps S11 and S12 constitute a detection process, which can be performed within a third preset duration. The third preset duration can be the same time interval as the aforementioned first preset duration, or it can be a time interval of different duration; this disclosure does not limit it in this regard.

[0085] In step S13, the position of the target is determined based on the photon counting results of the detection unit array using the laser triangulation principle. If the number of first photons corresponding to all detection units has been counted in descending order, the position of the target can be determined based on the photon counting results of all detection units. If the number of first photons corresponding to some detection units has not been counted in descending order, the position of the target can be determined based on the photon counting results of the detection units after the count has been decremented, and the number of first photons corresponding to the detection units that have not been counted in descending order. The following explanation uses the case where the number of first photons corresponding to each detection unit has been counted in descending order, and the determination of the target's position based on the photon counting results of each detection unit in the detection unit array is an example. The method for determining the target's position using the laser triangulation principle when the number of first photons has not been counted in descending order is similar and will not be repeated here.

[0086] In some embodiments, the detection unit corresponding to the maximum photon count result in the photon count results of the detection unit array can be used as the target detection unit; or the detection unit corresponding to the center position / centroid position of multiple detection units corresponding to photon count results greater than the quantity threshold can be determined as the target detection unit, and then the position of the target to be measured can be determined based on the position of the target detection unit in the detection unit array and the laser triangulation principle.

[0087] In some embodiments, after obtaining the distance result based on the aforementioned method, the ranging device may also correct it by a preset error amount and determine the corrected result as the position of the target to be measured; wherein, the preset error amount may be obtained through multiple tests.

[0088] Understandably, on the one hand, this application can eliminate the influence of ambient light by subtracting the photon count of ambient light during the photon counting stage, thereby reducing the interference of ambient light on the ranging results and improving the signal-to-noise ratio. On the other hand, in related technologies, the mixed photon count of ambient light and target reflected light and the photon count of ambient light are counted and stored separately. The data from the two photon counts need to be stored twice, requiring a large amount of storage space. However, the embodiments of this disclosure count and store the mixed photon count of ambient light and target reflected light detected by each detection unit when a light pulse is emitted. Based on this, when no light pulse is emitted, the photons of ambient light are detected in real time, and the count is decremented in real time based on the mixed photon count of ambient light and target reflected light corresponding to the detection unit. This eliminates the influence of the photon count of ambient light and eliminates the need to store the photon count data of ambient light, greatly reducing memory usage and improving the real-time performance of ranging. Furthermore, in related technologies, the mixed photon count of ambient light and target reflected light is subtracted from the photon count of ambient light using a subtractor, which requires a large amount of computation on the binary digital encoding of the two photon counts. However, the embodiments of this disclosure are based on the photons detected by ambient light and the mixed photon count of ambient light and target reflected light is used for decrementing the count, which can avoid computation on the binary digital encoding, thereby reducing the computational load and reducing the requirements for hardware resources.

[0089] Furthermore, under strong ambient light conditions, the laser triangulation method's detected light spot, reflecting the distance to the target, is affected by the ambient light photon count, making the light spot appear weak, indistinct, and scattered in the detector array. This makes it difficult to determine the center position of the light spot, and consequently, difficult to calculate the true distance to the target based on the center position and the principle of laser triangulation. This application is based on the principle of laser triangulation. By reducing the ambient light photon count as described above, the intensity and dispersion of the light spot formed by the ambient light photon count on the detector array can be reduced. This makes the light spot formed by the light pulse reflected from the target on the detector array more obvious and concentrated, facilitating accurate positioning of the light spot center and improving measurement accuracy and efficiency.

[0090] In some embodiments, the step of obtaining the photon count result of the detection unit array by decrementing the count based on the number of first photons detected by the corresponding detection unit in response to the detection of a second photon when the light pulse is not emitted includes:

[0091] If no light pulse is emitted for a second preset time period, in response to the detection of the second photon, the photon count of the detection unit array is obtained by counting down based on the number of first photons detected by the corresponding detection unit;

[0092] Wherein, the corresponding detection unit is the detection unit that detects the second photon; the number of the first photons detected by the corresponding detection unit is recorded based on multiple light pulses continuously emitted within a first preset time period, taking the photons detected by the corresponding detection unit or its neighboring detection unit as the first photons, and counting them incrementally; the positional interval between the corresponding detection unit and any of the neighboring detection units is less than a preset distance threshold; the first preset time period and the second preset time period are time intervals of the same duration.

[0093] In this embodiment of the disclosure, the laser triangulation ranging method includes two detection processes, corresponding to the aforementioned first and second detection processes. In the first detection process, the detection duration is a first preset duration. Within this first preset duration, multiple light pulses are continuously emitted. In response to detecting a photon, the detection unit in the detection unit array increments the count of the photon as the first photon to obtain the number of first photons corresponding to the detection unit. Specifically, each time a detection unit detects a first photon, it adds the number of first photons associated with that detection unit (initially 0) to the stored number of first photons, and updates the result of the addition operation in the storage space used to store the number of first photons. This is the "incremental counting" defined in this embodiment of the disclosure.

[0094] During the second detection process, the detection duration is the same as the first preset duration. If no light pulse is emitted within the second preset duration, the detection unit in the detection unit array responds to the detection of the second photon by counting the number of the first photons corresponding to the detection unit (i.e., the corresponding detection unit) that detected the second photon, and obtains the photon count result corresponding to the detection unit. The photon count result of the detection unit array can be obtained through this counting method.

[0095] It should be noted that if the corresponding detection unit does not detect the first photon within the first preset time period, then the actual number of first photons detected by the corresponding detection unit is zero. In this case, the number of first photons detected by the neighboring detection units of the corresponding detection unit can be used as the number of first photons detected by the corresponding detection unit, and used by the corresponding detection unit to count down in response to the detection of the second photon within the second preset time period.

[0096] It is understood that, based on a first preset duration and a second preset duration, the embodiments of this disclosure distinguish the photons detected in the first detection process as first photons and the photons detected in the second detection process as second photons. In the event that no light pulses are emitted continuously within the second preset duration, in response to the detection of second photons, the number of photons detected by the corresponding detection unit is counted in descending order based on the number of first photons detected by the corresponding detection unit to obtain the photon count result of the detection unit array. No additional storage space is required to store the photon statistics of the ambient light detected in the second detection, and the amount of logic processing is small, which has the advantages of being simple and easy to implement.

[0097] In some embodiments, the step of obtaining the photon count result of the detection unit array by decrementing the count based on the number of first photons detected by the corresponding detection unit in response to the detection of a second photon when the light pulse is not emitted includes:

[0098] Obtain time information of light pulse emission within a third preset time period; wherein, the time information includes the pulse period during which the light pulse is emitted and the gap period during which the light pulse is not emitted, and at least one pulse period and at least one gap period alternate;

[0099] If no light pulse is emitted during any of the aforementioned gap periods, in response to the detection of the second photon, a count is performed by decreasing the number of the first photons detected by the corresponding detection unit to obtain the photon count result of the detection unit array.

[0100] Wherein, the corresponding detection unit is the detection unit that detects the second photon; the number of the first photons detected by the corresponding detection unit is obtained by taking the photons detected by the corresponding detection unit or the neighboring detection unit of the corresponding detection unit during the pulse period as the first photons and counting them incrementally; the positional interval between the corresponding detection unit and any of the neighboring detection units is less than a preset distance threshold.

[0101] In this embodiment of the disclosure, the laser triangulation ranging method includes a photon detection process within a third preset time period. This is achieved by modulating a sequence of optical pulses, such as selecting several optical pulses from a periodically continuously emitted sequence within the preset time period and modulating them into non-emitting pulses. The modulated optical pulses thus include pulse periods of emitted pulses and gap periods of non-emitting pulses; wherein at least one pulse period and at least one gap period alternate. Figure 2 As shown, Figure 2 The diagram shown is an example of a modulated optical pulse provided in an embodiment of this disclosure, wherein the time marked by L1 corresponds to the pulse period and the time marked by L2 corresponds to the gap period.

[0102] This embodiment of the present disclosure, based on the modulated light pulse, obtains the time information of the light pulse emission within a third preset time period, including the pulse period and the gap period. During the pulse period of the emitted light pulse, the ranging device uses the photons detected by the detection unit as the first photons and increments the count (e.g., by 1) to obtain the number of first photons corresponding to the detection unit. For each gap period without emitted light pulses, the ranging device uses the photons detected by the detection unit as the second photons. Based on the number of first photons detected by the detection unit (corresponding detection unit) or its neighboring detection unit, it decrements the count (e.g., by 1) to obtain the photon count result corresponding to the corresponding detection unit. The positional distance between the corresponding detection unit and any neighboring detection unit is less than a preset distance threshold. The incrementing or decrementing count can be controlled by logic gates in the counter.

[0103] It is understood that the embodiments of this disclosure, based on modulated light pulses, distinguish between emitted and unemitted light pulses by pulse duration and gap duration, thereby achieving photon counting results through a single detection process based on modulated light pulses, thus improving the efficiency of determining the location of the target. Furthermore, the ranging device can adjust the ratio of the pulse duration to the gap duration of the light pulse as needed. For example, by increasing the ratio of the pulse duration to the gap duration, the flexibility of increasing the light pulse intensity and signal-to-noise ratio can be achieved.

[0104] Moreover, in this embodiment of the present disclosure, since the reduction of ambient light photons is carried out during the gap period, and the gap period is more evenly distributed in the measurement frames within the entire third preset duration, the ambient light photons within the third preset duration measurement frames can be reduced more evenly. This can overcome the problem that the ambient light reduction is biased due to the change in ambient light caused by the long time span between the two measurement frames.

[0105] In some embodiments, when no light pulse is emitted during each of the gap periods, in response to the detection of the second photon, a count is performed decrementally based on the number of first photons detected by the corresponding detection unit to obtain the photon count result of the detection unit array, including:

[0106] Based on the number of pulse periods and the number of gap periods in the time information, the first photon reduction of the ambient light is determined; wherein, the first photon reduction is positively correlated with the ratio between the number of pulse periods and the number of gap periods;

[0107] If no light pulse is emitted during each of the aforementioned gap periods, in response to the detection of the second photon, the photon count of the detection unit array is obtained by decreasing the count based on the number of first photons detected by the corresponding detection unit according to the amount of decrease in the first photon count.

[0108] In this embodiment of the disclosure, the ratio between the number of pulse periods and the number of gap periods in the time information of the light pulse, or the weighted value of the ratio, can be determined as the first photon reduction of the ambient light, so that the first photon reduction is positively correlated with the ratio between the number of pulse periods and the number of gap periods.

[0109] In each gap period, when no light pulse is emitted, the ranging device of this disclosure, in response to the detection of a second photon, counts the photons of the corresponding detection unit array by decreasing the number of first photons based on the decrease in the number of first photons. For example, the photon count of the corresponding detection unit is obtained by subtracting the decrease in the number of first photons from the number of first photons of that detection unit.

[0110] It is understandable that a larger ratio between the number of pulse periods and the number of idle periods indicates more effective emission of the light pulses and fewer non-emissions. Consequently, fewer idle periods result in fewer detectable second photons, meaning the photon count of ambient light during shorter idle periods may not accurately reflect the photon count of ambient light during more pulse periods. If the decrementing count during idle periods is still based on "1," the reduction in ambient light photon count will not match the actual ambient light photon count, meaning the ambient light in a single photon detection process cannot be accurately reduced. Therefore, this embodiment of the present disclosure sets a first photon reduction amount based on the ratio of the number of pulse periods to the number of idle periods. This allows the reduction in ambient light photon count to match the actual ambient light photon count, thereby more accurately reducing the influence of ambient light in a single photon detection process and improving the signal-to-noise ratio.

[0111] In addition, embodiments of this disclosure can increase the effective number of optical pulses by setting a larger ratio between the number of pulse periods and the number of gap periods, thereby increasing the signal strength of the optical pulse signal and further improving the signal-to-noise ratio.

[0112] In some embodiments, the step of decreasing the count based on the number of first photons detected by the corresponding detection unit to obtain the photon count result of the detection unit array according to the first photon reduction amount includes:

[0113] The first photon reduction is distributed to the corresponding detection unit and / or neighboring detection units in an equal or non-equal manner to obtain the second photon reduction of the corresponding detection unit and / or neighboring detection units respectively.

[0114] For each of the corresponding detection units and / or neighboring detection units, based on the number of first photons detected by the detection unit, the decrease in the count of the second photons corresponding to the detection unit is decremented to obtain the photon count result of the detection unit array.

[0115] The phrase "based on the number of first photons detected by the detection unit, the decrease in the number of second photons corresponding to the detection unit is counted in descending order" can be understood as using the decrease in the number of second photons as the subtrahend and the number of first photons detected by the detection unit as the minuend for the count. If a detection unit detects a second photon, the decrease in the number of first photons detected by that unit is subtracted from the number of second photons detected.

[0116] In the embodiments of this disclosure, when a second photon is detected, the ratio of the reduction in the first photon to the total number of detection units in the corresponding detection unit and the neighboring detection units can be used as the reduction in the second photon evenly distributed to each detection unit in the corresponding detection unit and the neighboring detection units; or, it can be distributed non-uniformly to the corresponding detection unit and the neighboring detection units to obtain the reduction in the second photon for each detection unit in the corresponding detection unit and the neighboring detection units respectively.

[0117] It should be noted that when the first photon reduction is evenly distributed among the corresponding detection unit and the neighboring detection units, if the ratio of the first photon reduction to the total number of corresponding and neighboring detection units is an integer, then this integer is used as the second photon reduction amount distributed among the corresponding and neighboring detection units respectively. If the ratio is not an integer, then the non-integer is rounded down and used as the second photon reduction amount distributed among the corresponding and neighboring detection units respectively. Rounding down a non-integer can include taking the smallest integer greater than the non-integer and the largest integer less than the non-integer. As long as the difference between the second photon reduction amounts of the corresponding detection unit and the neighboring detection unit does not exceed 1, the second photon reduction amounts of the corresponding detection unit and the neighboring detection unit can be considered approximately equal.

[0118] After determining the second photon reduction amount for the corresponding detection unit and the neighboring detection unit respectively, this embodiment of the present disclosure performs a count by subtracting the number of the first photon corresponding to the detection unit as the minuend and the second photon reduction amount as the subtrahend for each detection unit among the corresponding detection unit and the neighboring detection unit, and determines the difference between the number of the first photon and the second photon reduction amount as the photon count result corresponding to the detection unit.

[0119] It is understood that, since ambient light is continuous over time, in the embodiments of this disclosure, when a second photon (a photon of ambient light) is detected, a corresponding detection unit or / and at least one neighboring detection unit is determined, and the reduction amount of the first photon is distributed to the detection units in an equal or non-equal manner. This is equivalent to performing a smoothing filter on the number of the first photons corresponding to the detection units, thereby making the influence of the photons of ambient light on the photon counting results of the detection unit array more uniform and improving the accuracy of determining the photon counting results of the detection unit array.

[0120] In some embodiments, distributing the first photon reduction amount non-uniformly to the corresponding detection unit and / or neighboring detection units to obtain the second photon reduction amount for each of the corresponding detection unit and / or neighboring detection units includes:

[0121] The first photon reduction amount is allocated to the corresponding detection unit and / or neighboring detection units according to different preset weights, so as to obtain the second photon reduction amount of the corresponding detection unit and / or neighboring detection units respectively.

[0122] In this embodiment of the disclosure, after detecting a second photon and determining the corresponding detection unit and / or at least one neighboring detection unit, the reduction amount of the first photon is allocated to the aforementioned detection units according to different preset weights, thereby obtaining the reduction amount of the second photon for each detection unit. The preset weights can be randomly generated or determined based on the temporal distance between the neighboring detection unit and the corresponding detection unit that detected the second photon. For example, the closer the neighboring detection unit is to the corresponding detection unit, the larger the preset weight corresponding to that neighboring detection unit.

[0123] It is understood that, based on different preset weights, the second photon reduction amount determined based on the first photon reduction amount can be dynamically adjusted as needed, so that the photon count allocation of ambient light is more in line with the actual situation, improves the restoration of the photon count of ambient light in the actual measurement scenario, and achieves a more realistic effect of reducing the influence of ambient light.

[0124] In some embodiments, determining the position of the target based on the photon counting result includes:

[0125] Based on the photon counting results, a histogram is generated;

[0126] Determine the target detection unit corresponding to the highest peak in the histogram;

[0127] The location of the target to be detected is determined based on the target detection unit.

[0128] In this embodiment of the disclosure, when a light pulse is emitted, in response to the detection of a first photon, the number of first photons detected by each detection unit is determined, and a histogram is generated, such as... Figure 3 The histogram showing the distribution of the number of the first photons in the detector unit is shown.

[0129] In this embodiment of the present disclosure, without emitting a light pulse, in response to the detection of a second photon, a count is performed decrementally based on the number of first photons corresponding to the detection unit to obtain the photon count result corresponding to the detection unit, and a histogram is generated, as shown below. Figure 4 The histogram showing the photon counting results distributed across the detector cells is presented, where detector cell L3 corresponds to the highest peak. It can be seen that... Figure 4 The height of the middle bar chart is less than Figure 3 The height of the middle bar chart, Figure 4 The histogram shown is a histogram of the distribution of photon count results in the detection unit after removing ambient light interference.

[0130] The embodiments disclosed herein are based on, as follows Figure 4 The histogram shown is used to identify the target detection unit corresponding to the peak representing the maximum number of photons in the histogram, which corresponds to the detection unit marked L3. Based on the target detection unit and the triangulation principle, the position of the target to be measured is determined.

[0131] In some embodiments, after obtaining the highest peak of the histogram, the counting results of the detection unit where the highest peak of the photon counting result is located and multiple nearby detection units can be processed by centroid algorithm, etc., to determine the target detection unit that accurately reflects the distance to the target to be measured, and calculate the position of the target to be measured based on the laser triangulation principle.

[0132] It is understood that the embodiments of this disclosure are based on histogram statistics, which can conveniently and quickly determine the target detection unit, thereby improving the efficiency of determining the position of the target to be measured based on the target detection unit.

[0133] In some embodiments, determining the position of the target to be detected based on the target detection unit includes:

[0134] Based on the position of the target detection unit in the detection unit array, and combined with the principle of laser triangulation, the position of the target to be measured is determined.

[0135] In this embodiment of the disclosure, after the target detection unit is determined, the position of the target detection unit in the detection unit array is the position of the image of the target under test on the detection unit array after being acted upon by the light pulse (i.e., the light spot formed on the detection unit array after the light pulse is reflected by the target under test).

[0136] This disclosure determines the position of the target based on the position of the target detection unit in the detection unit array and the principle of laser triangulation. Figure 5 For example, Figure 5 This is an example diagram of triangulation provided in an embodiment of the present disclosure. Figure 5 In this diagram, SPAD corresponds to the target detection unit, the reference plane is a preset virtual plane, the measurement plane represents the plane where the target to be measured is located, M is the reference target at the position where the laser-emitted light pulse passes through the reference plane, N is the target to be measured at the position where the laser-emitted light pulse arrives at the measurement plane, M' corresponds to the "imaging point" of the reference target on the SPAD array, and N' corresponds to the "imaging point" of the target to be measured on the SPAD array. Figure 5 It can be seen that, based on the laws of optical reflection and the similarity between triangle OPN and triangle OP'N', the following formula (2) can be derived:

[0137]

[0138] Figure 5 In this process, the distance from the laser to the reference plane is a known parameter. Therefore, by determining the distance m from the measurement plane where the target is located to the reference plane, the distance from the target to the laser can be determined, which is the distance of the target to be measured. Figure 5 In the equation (2), l is the distance from the receiving lens (point O) to point M, l' is the distance from the receiving lens to M', β is the angle between point O, point M, and the laser's location, and γ is the angle between OM and the reference plane. Based on formula (2), m can be calculated. Since the distance between the laser and the reference plane is known, the distance between the laser and the target is the sum of m and the distance between the laser and the reference plane.

[0139] It should be noted that, Figure 5 The laser triangulation method provided in this embodiment can be implemented in practice by setting multiple receiving lenses as needed, and the position of the reference plane can also be set as needed, such as setting it to have a preset angle with the measurement plane. The laser triangulation method of this embodiment can still be realized based on the principle of triangle similarity and the law of optical reflection, which will not be elaborated here.

[0140] Understandably, compared to time-of-flight ranging, which requires determining the time of photon detection, the time of photon detection is highly random and easily affected by factors such as the generation delay of the control signal controlling the laser to emit light pulses and the transmission delay of the control signal to the laser emitter. In this regard, the embodiments of this disclosure determine the position of the target to be measured based on the position of the target detection unit in the detection unit array and the principle of laser triangulation, thereby reducing the influence of ambient light on the ranging and further improving the accuracy of the ranging results.

[0141] Figure 6 This diagram illustrates an example of a laser triangulation ranging device provided in an embodiment of this disclosure. Figure 6 It can be seen that this includes:

[0142] The response module 601 is configured to respond to the detection of a first photon when a light pulse is emitted, and to respond to the detection of a second photon when the light pulse is not emitted; wherein the first photon includes photons of the light pulse reflected by the target and photons of ambient light, and the second photon includes photons of ambient light;

[0143] The counting module 602 is used to determine the number of first photons detected by each detection unit in the detection unit array in response to the detection of a first photon when a light pulse is emitted; and to perform a count by decrementing based on the number of first photons detected by the corresponding detection unit in response to the detection of a second photon when no light pulse is emitted, so as to obtain the photon count result of the detection unit array.

[0144] The data processing module 603 is used to determine the position of the target to be measured based on the photon counting results.

[0145] In some embodiments, the counting module 602 is configured to, in response to the detection of the second photon, perform a count based on the number of first photons detected by the corresponding detection unit when no light pulse is emitted continuously for a second preset time period, to obtain the photon count result of the detection unit array.

[0146] Wherein, the corresponding detection unit is the detection unit that detects the second photon; the number of the first photons detected by the corresponding detection unit is recorded based on multiple light pulses continuously emitted within a first preset time period, taking the photons detected by the corresponding detection unit or its neighboring detection unit as the first photons, and counting them incrementally; the positional interval between the corresponding detection unit and any of the neighboring detection units is less than a preset distance threshold; the first preset time period and the second preset time period are time intervals of the same duration.

[0147] In some embodiments, the counting module 602 is used to acquire time information of light pulse emission within a third preset duration; wherein, the time information includes the pulse period during which the light pulse is emitted and the gap period during which the light pulse is not emitted, and at least one pulse period and at least one gap period alternate; in the case that no light pulse is emitted during each of the gap periods, in response to the detection of the second photon, the counting is performed by decrementing based on the number of first photons detected by the corresponding detection unit to obtain the photon counting result of the detection unit array;

[0148] Wherein, the corresponding detection unit is the detection unit that detects the second photon; the number of the first photons detected by the corresponding detection unit is obtained by taking the photons detected by the corresponding detection unit or the neighboring detection unit of the corresponding detection unit during the pulse period as the first photons and counting them incrementally; the positional interval between the corresponding detection unit and any of the neighboring detection units is less than a preset distance threshold.

[0149] In some embodiments, the counting module 602 is configured to determine a first photon reduction amount of the ambient light based on the number of pulse periods and the number of gap periods in the time information; wherein the first photon reduction amount is positively correlated with the ratio between the number of pulse periods and the number of gap periods; in the case that no light pulse is emitted during each of the gap periods, in response to the detection of the second photon, the counting is performed by decreasing the count based on the number of first photons detected by the corresponding detection unit according to the first photon reduction amount, to obtain the photon counting result of the detection unit array.

[0150] In some embodiments, the counting module 602 is used to distribute the first photon reduction amount to the corresponding detection unit and / or neighboring detection units in an equal or non-equal manner, so as to obtain the second photon reduction amount of the corresponding detection unit and / or neighboring detection units respectively; for each detection unit in the corresponding detection unit and / or neighboring detection units, based on the number of first photons detected by the corresponding detection unit, the second photon reduction amount corresponding to the detection unit is counted by decreasing the count to obtain the photon counting result of the detection unit array.

[0151] In some embodiments, the counting module 602 is used to allocate the first photon reduction amount to the corresponding detection unit and / or neighboring detection units according to different preset weights, so as to obtain the second photon reduction amount of the corresponding detection unit and / or neighboring detection units respectively.

[0152] In some embodiments, the data processing module 603 is configured to generate a histogram based on the photon counting results; determine the target detection unit corresponding to the highest peak in the histogram; and determine the position of the target to be measured based on the target detection unit.

[0153] In some embodiments, the data processing module 603 is used to determine the position of the target to be measured based on the position of the target detection unit in the detection unit array and in combination with the principle of laser triangulation.

[0154] Figure 7 This embodiment of the present disclosure illustrates a laser triangulation ranging device, consisting of... Figure 7 It can be seen that this includes:

[0155] A single-photon avalanche diode array 701 includes multiple single-photon avalanche diodes, wherein the single-photon avalanche diodes are used to detect a first photon when a light pulse is emitted, and to detect a second photon when the light pulse is not emitted; wherein the first photon includes photons of the light pulse reflected by the target and photons of ambient light, and the second photon includes photons of ambient light;

[0156] The counter array 702 includes multiple counters, each corresponding to one of the single-photon avalanche diodes; the counters are used to determine the number of first photons detected by each single-photon avalanche diode in the single-photon avalanche diode array when a light pulse is emitted and the single-photon avalanche diode array responds to detecting a first photon; and to count the photons of the single-photon avalanche diode array by decrementing the count based on the number of first photons detected by the corresponding single-photon avalanche diode when no light pulse is emitted and the single-photon avalanche diode array responds to detecting a second photon, thereby obtaining the photon count result of the single-photon avalanche diode array;

[0157] The central processing unit 703 is used to determine the position of the target under test based on the photon counting results. The central processing unit 703 may include circuitry containing devices such as a central processing unit (CPU) and a microcontroller unit (MCU).

[0158] In some embodiments, the counter array 702 is configured to, in response to the detection of the second photon, count the photons of the single-photon avalanche diode array by decreasing the count based on the number of the first photons detected by the corresponding single-photon avalanche diode when no light pulses are emitted continuously for a second preset time period.

[0159] Wherein, the corresponding single-photon avalanche diode is the single-photon avalanche diode that detects the second photon; the number of first photons detected by the corresponding single-photon avalanche diode is recorded by incrementing the count of multiple light pulses continuously emitted within a first preset time period, taking the photons detected by the corresponding single-photon avalanche diode or its neighboring single-photon avalanche diodes as the first photons; the positional interval between the corresponding single-photon avalanche diode and any of the neighboring single-photon avalanche diodes is less than a preset distance threshold; the first preset time period and the second preset time period are time intervals of the same duration.

[0160] In some embodiments, the counter array 702 is used to acquire time information of light pulse emission within a third preset duration; wherein, the time information includes the pulse period during which the light pulse is emitted and the gap period during which the light pulse is not emitted, and at least one pulse period and at least one gap period alternate; in the case that no light pulse is emitted during each of the gap periods, in response to the detection of the second photon, the count is decremented based on the number of first photons detected by the corresponding single-photon avalanche diode to obtain the photon count result of the single-photon avalanche diode array;

[0161] Wherein, the corresponding single-photon avalanche diode is a single-photon avalanche diode that detects the second photon; the number of first photons detected by the corresponding single-photon avalanche diode is obtained by taking the photons detected by the corresponding single-photon avalanche diode or its neighboring single-photon avalanche diode during the pulse period as the first photons and counting them incrementally; the positional interval between the corresponding single-photon avalanche diode and any of the neighboring single-photon avalanche diodes is less than a preset distance threshold.

[0162] In some embodiments, the counter array 702 is used to determine a first photon reduction amount of the ambient light based on the number of pulse periods and the number of gap periods in the time information; wherein the first photon reduction amount is positively correlated with the ratio between the number of pulse periods and the number of gap periods; in the case that no light pulse is emitted during each of the gap periods, in response to the detection of the second photon, the photon count of the single-photon avalanche diode array is obtained by decreasing the count based on the number of first photons detected by the corresponding single-photon avalanche diode, according to the first photon reduction amount.

[0163] In some embodiments, the counter array 702 is used to distribute the first photon reduction amount equally or unevenly to the corresponding single-photon avalanche diode or / and neighboring single-photon avalanche diodes, respectively obtaining the second photon reduction amount of the corresponding single-photon avalanche diode or / and neighboring single-photon avalanche diodes; for each single-photon avalanche diode in the corresponding single-photon avalanche diode or / and neighboring single-photon avalanche diodes, based on the number of first photons detected by the corresponding single-photon avalanche diode, the second photon reduction amount corresponding to the single-photon avalanche diode is counted in descending order to obtain the photon counting result of the single-photon avalanche diode array.

[0164] In some embodiments, the counter array 702 is used to allocate the first photon reduction amount to the corresponding single-photon avalanche diode or / and the adjacent single-photon avalanche diode according to different preset weights, so as to obtain the second photon reduction amount of the corresponding single-photon avalanche diode or / and the adjacent single-photon avalanche diode respectively.

[0165] In some embodiments, the central processing unit 703 is configured to generate a histogram based on the photon counting results; determine the target single-photon avalanche diode corresponding to the highest peak in the histogram; and determine the position of the target under test based on the target single-photon avalanche diode.

[0166] In some embodiments, the central processing unit 703 is used to determine the position of the target to be measured based on the position of the target single-photon avalanche diode in the single-photon avalanche diode array, combined with the principle of laser triangulation.

[0167] Correspondingly, embodiments of this disclosure provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements some or all of the steps in the above method.

[0168] It should be noted that the descriptions of the storage medium and device embodiments above are similar to those of the method embodiments above, and have similar beneficial effects. For technical details not disclosed in the storage medium and device embodiments of this disclosure, please refer to the descriptions of the method embodiments of this disclosure for understanding.

[0169] It should be understood that the phrase "an embodiment" or "one embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of this disclosure. Therefore, "in one embodiment" or "one embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of this disclosure, the sequence numbers of the above-described processes do not imply a sequential order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this disclosure. The sequence numbers of the above-described embodiments are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0170] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0171] In the several embodiments provided in this disclosure, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components may be combined, or integrated into another system, or some features may be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed may be through some interfaces, and the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0172] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units. They may be located in one place or distributed across multiple network units. Some or all of the units may be selected to achieve the purpose of this embodiment according to actual needs.

[0173] In addition, each functional unit in the various embodiments of this disclosure can be integrated into one processing unit, or each unit can be a separate unit, or two or more units can be integrated into one unit; the integrated unit can be implemented in hardware or in the form of hardware plus software functional units.

[0174] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media that can store program code, such as mobile storage devices, read-only memory (ROM), magnetic disks, or optical disks.

[0175] Alternatively, if the integrated units described above are implemented as software functional modules and sold or used as independent products, they can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this disclosure, or the part that contributes to related technologies, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the methods described in the various embodiments of this disclosure. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, ROM, magnetic disks, or optical disks.

[0176] The above description is merely an embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A laser triangulation ranging method, characterized in that, The method includes: When a light pulse is emitted, in response to the detection of a first photon, the number of first photons detected by each detection unit in the detection unit array is determined; wherein, the first photon includes photons of the light pulse reflected by the target and photons of ambient light; Obtain time information of light pulse emission within a third preset time period; wherein, the time information includes multiple pulse periods during which the light pulse is emitted and multiple gap periods during which the light pulse is not emitted, and the pulse periods and the gap periods alternate; Based on the number of pulse periods and the number of gap periods in the time information, the first photon reduction of the ambient light is determined; wherein, the first photon reduction is positively correlated with the ratio between the number of pulse periods and the number of gap periods; If no light pulse is emitted during each of the aforementioned gap periods, in response to the detection of a second photon, the photon count of the detection unit array is obtained by counting down based on the number of first photons detected by the corresponding detection unit, according to the amount of reduction of the first photon; Wherein, the second photon includes photons of ambient light; the corresponding detection unit is a detection unit that detects the second photon; the number of first photons detected by the corresponding detection unit is obtained by taking the photons detected by the corresponding detection unit or its neighboring detection unit during the pulse period as the first photons and counting them incrementally; the positional interval between the corresponding detection unit and any of the neighboring detection units is less than a preset distance threshold. Based on the photon counting results, the position of the target to be measured is determined.

2. The method according to claim 1, characterized in that, The step of counting the photons of the detection unit array by decreasing the number of first photons detected by the corresponding detection unit based on the decrease in the first photon count includes: The first photon reduction is distributed to the corresponding detection unit and / or neighboring detection units in an equal or non-equal manner to obtain the second photon reduction of the corresponding detection unit and / or neighboring detection units respectively. For each of the corresponding detection units and / or neighboring detection units, based on the number of first photons detected by the detection unit, the decrease in the number of second photons corresponding to the detection unit is counted incrementally to obtain the photon count result of the detection unit array.

3. The method according to claim 2, characterized in that, The step of distributing the first photon reduction amount non-uniformly to the corresponding detection unit and / or neighboring detection units to obtain the second photon reduction amount for the corresponding detection unit and / or neighboring detection units respectively includes: The first photon reduction amount is allocated to the corresponding detection unit and / or neighboring detection units according to different preset weights, so as to obtain the second photon reduction amount of the corresponding detection unit and / or neighboring detection units respectively.

4. The method according to claim 1, characterized in that, Determining the position of the target based on the photon counting results includes: Based on the photon counting results, a histogram is generated; Determine the target detection unit corresponding to the highest peak in the histogram; The location of the target to be detected is determined based on the target detection unit.

5. The method according to claim 4, characterized in that, Determining the position of the target to be detected based on the target detection unit includes: Based on the position of the target detection unit in the detection unit array, and combined with the principle of laser triangulation, the position of the target to be measured is determined.

6. A laser triangulation ranging device, characterized in that, The device includes: A response module is configured to respond to the detection of a first photon when a light pulse is emitted, and to respond to the detection of a second photon when the light pulse is not emitted; wherein the first photon includes photons of the light pulse reflected by the target and photons of ambient light, and the second photon includes photons of ambient light; A counting module is used to acquire time information of light pulse emission within a third preset time period; wherein, the time information includes multiple pulse periods during which the light pulse is emitted and multiple gap periods during which the light pulse is not emitted, the pulse periods and the gap periods alternating; based on the number of pulse periods and the number of gap periods in the time information, a first photon reduction amount of the ambient light is determined; wherein, the first photon reduction amount is positively correlated with the ratio between the number of pulse periods and the number of gap periods; in the case that no light pulse is emitted during each of the gap periods, in response to the detection of a second photon, based on the first photon reduction amount, a count is performed decreasingly based on the number of first photons detected by the corresponding detection unit to obtain the photon counting result of the detection unit array; Wherein, the second photon includes photons of ambient light; the corresponding detection unit is a detection unit that detects the second photon; the number of first photons detected by the corresponding detection unit is obtained by taking the photons detected by the corresponding detection unit or its neighboring detection unit during the pulse period as the first photons and counting them incrementally; the positional interval between the corresponding detection unit and any of the neighboring detection units is less than a preset distance threshold. The data processing module is used to determine the position of the target to be measured based on the photon counting results.

7. A laser triangulation ranging device, characterized in that, The device includes: A single-photon avalanche diode array includes multiple single-photon avalanche diodes, wherein the single-photon avalanche diodes are used to detect a first photon in response to the emission of a light pulse, and to detect a second photon in response to the absence of the light pulse; wherein the first photon includes photons of the light pulse reflected by the target and photons of ambient light, and the second photon includes photons of ambient light; A counter array, comprising multiple counters, each corresponding to one of the single-photon avalanche diodes; the counters are used for The time information of light pulse emission within a third preset duration is obtained; wherein, the time information includes multiple pulse periods during which the light pulse is emitted and multiple gap periods during which the light pulse is not emitted, the pulse periods and the gap periods alternating; based on the number of pulse periods and the number of gap periods in the time information, the first photon reduction amount of the ambient light is determined; wherein, the first photon reduction amount is positively correlated with the ratio between the number of pulse periods and the number of gap periods; in the case that no light pulse is emitted during each of the gap periods, in response to the detection of the second photon, based on the first photon reduction amount, a count is performed decreasingly based on the number of first photons detected by the corresponding single-photon avalanche diode to obtain the photon count result of the single-photon avalanche diode array; Wherein, the second photon includes photons of ambient light; the corresponding single-photon avalanche diode is a single-photon avalanche diode that detects the second photon; the number of first photons detected by the corresponding single-photon avalanche diode is obtained by taking the photons detected by the corresponding single-photon avalanche diode or its neighboring single-photon avalanche diode during the pulse period as the first photons and counting them incrementally; the positional distance between the corresponding single-photon avalanche diode and any of the neighboring single-photon avalanche diodes is less than a preset distance threshold; A central processing unit is used to determine the position of the target under test based on the photon counting results.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method of any one of claims 1 to 5.

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