Anti-interference DTOF ranging method and device and electronic equipment

Abstract

The invention provides an anti-interference DTOF distance measurement method and device and electronic equipment, and the method comprises the steps: setting a gray-scale map mode and a distance measurement mode, and enabling the resolution in the gray-scale map mode to be higher than the resolution in the distance measurement mode; in the gray-scale map mode, starting a pixel array to perform first exposure on all objects in the field of view to obtain a corresponding gray-scale map; determining interference SPAD pixels in the pixel array according to the grey-scale map, wherein the interference SPAD pixels correspond to non-target objects in the detection view field; in the distance measurement mode, closing the interference SPAD pixels, and performing second exposure on the target object in the field of view through the remaining opened SPAD pixels to obtain corresponding original histogram data; and calculating distance information of the target object according to the original histogram data. The non-target object in the field of view is distinguished through the high-resolution grey-scale map, and the corresponding interference SPAD pixel is closed, so that the interference caused by the signal peak of the non-target object can be avoided in the distance measurement mode, and the distance measurement accuracy is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of distance detection, and in particular to an anti-interference DTOF ranging method, device and electronic device. Background Art

[0002] A d-ToF (direct time-of-flight) ranging system uses a laser to emit pulsed laser light. The pulsed laser light is reflected by the surface of the target object and received by the receiving end SPAD (Single-photon avalanche diode). The TDC (time-to-digital converter) records the time interval from light emission to light reception, and then converts it into the flight distance. Since the d-ToF ranging system directly measures the flight time and different echo signals are naturally at different time scales, the accurate echo distance can be obtained. Therefore, compared with the i-ToF (indirect time-of-flight) ranging system, the d-ToF can more effectively avoid interference in a multipath scenario.

[0003] However, for dToF, there is still a problem that multiple valid signals interfere with each other, resulting in inaccurate measurement. Since the original histogram needs to go through matched filtering during depth calculation, the signal features are amplified and the noise is suppressed through convolution operation, and then the region information of the valid echo is obtained through peak searching to finally calculate the depth result. Therefore, when there are two or more objects that are relatively close to each other in the field of view of the corresponding pixel, as Figure 1 shown, the close signal distances may cause different signal peaks to merge with each other, so that the convolution histogram obtained after matched filtering will merge into a single signal peak and include multiple distance information, and finally an incorrect depth value is calculated, resulting in inaccurate distance detection. Summary of the Invention

[0004] In view of the above deficiencies of the prior art, the purpose of the present invention is to provide an anti-interference DTOF ranging method, device and electronic device, aiming to avoid the mutual interference between valid signal peaks and improve the ranging accuracy.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] The first aspect of the present invention provides an anti-interference DTOF ranging method, including the following steps:

[0007] Set the grayscale mode and the ranging mode, wherein the resolution in the grayscale mode is higher than that in the ranging mode;

[0008] In the grayscale image mode, turn on the pixel array to perform a first exposure on all objects in the field of view, obtaining a corresponding grayscale image;

[0009] Identify the interfering SPAD pixels in the pixel array according to the grayscale image, where the interfering SPAD pixels correspond to non-target objects in the detection field of view;

[0010] In the ranging mode, turn off the interfering SPAD pixels, and perform a second exposure on the target object in the field of view through the remaining turned-on SPAD pixels, obtaining corresponding original histogram data;

[0011] Calculate the distance information of the target object according to the original histogram data.

[0012] In one embodiment, in the grayscale image mode, output grayscale image data with a single SPAD pixel as the minimum detection unit;

[0013] In the ranging mode, output original histogram data with a pixel composed of multiple SPAD pixels as the minimum detection unit.

[0014] In one embodiment, the step of, in the grayscale image mode, turning on the pixel array to perform a first exposure on all objects in the field of view, obtaining a corresponding grayscale image, includes:

[0015] In the grayscale image mode, turn on the pixel array to receive the optical signals reflected by all objects in the field of view;

[0016] Perform photon counting on the received optical signals through each SPAD pixel in the pixel array to obtain the photon count value output by each SPAD pixel;

[0017] Use the photon count value of each SPAD pixel as the grayscale value of the corresponding SPAD to generate the grayscale image.

[0018] In one embodiment, the step of identifying the interfering SPAD pixels in the pixel array according to the grayscale image includes:

[0019] Distinguish different objects in the field of view according to the grayscale values at different positions in the grayscale image, and determine non-target objects among all objects;

[0020] Determine the pixel positions in the pixel array corresponding to the non-target objects, and mark them as interfering SPAD pixels.

[0021] In one embodiment, the step of distinguishing different objects in the field of view according to the grayscale values at different positions in the grayscale image specifically refers to:

[0022] In the grayscale image, the SPAD with a larger grayscale value corresponds to an object closer to the distance sensor in the field of view;

[0023] In the grayscale image, the SPAD with a smaller grayscale value corresponds to an object farther from the distance sensor in the field of view.

[0024] In one embodiment, determining the non-target object among all objects specifically includes:

[0025] Obtain the pre-configured positional relationship between the non-target object and the target object, and determine the non-target object among all objects according to the positional relationship.

[0026] In one embodiment, in the ranging mode, turning off the interfering SPAD pixels, and performing a second exposure on the target object in the field of view through the remaining turned-on SPAD pixels to obtain corresponding original histogram data, including:

[0027] In the ranging mode, turning off the interfering SPAD pixels, and receiving the optical signal reflected back by the target object in the field of view through the remaining turned-on SPAD pixels;

[0028] Combining every m*n turned-on SPAD pixels into one pixel, performing time-of-flight statistics on the received optical signal to obtain the original histogram data output by each pixel, where m≥2 and / or n≥2.

[0029] In one embodiment, the target object is specifically: the object closest to the distance sensor in the field of view.

[0030] A second aspect of the present invention provides an anti-interference DTOF ranging device, including:

[0031] A pixel array including a plurality of SPAD pixels;

[0032] A mode setting module for setting the grayscale image mode and the ranging mode, where the resolution in the grayscale image mode is higher than that in the ranging mode;

[0033] An exposure control module for, in the grayscale image mode, turning on the pixel array to perform a first exposure on all objects in the field of view to obtain a corresponding grayscale image; and confirming the interfering SPAD pixels in the pixel array according to the grayscale image, where the interfering SPAD pixels correspond to non-target objects in the detection field of view; and in the ranging mode, turning off the interfering SPAD pixels, and performing a second exposure on the target object in the field of view through the remaining turned-on SPAD pixels to obtain corresponding original histogram data;

[0034] A data processing module for calculating the distance information of the target object according to the original histogram data.

[0035] The third aspect of the present invention provides an electronic device, including the anti-interference DTOF ranging device as described above.

[0036] The beneficial effects of the present invention are as follows: providing an anti-interference DTOF ranging method, device and electronic device, differentiating non-target objects in the field of view through a high-resolution grayscale image and turning off the corresponding interfering SPAD pixels, so that interference caused by signal peaks of non-target objects can be avoided in the ranging mode, and the ranging accuracy can be effectively improved. Description of the Drawings

[0037] The present invention will be further described below in conjunction with the drawings and embodiments. In the drawings:

[0038] Figure 1 are histograms of two effectively fused signal peaks in the prior art before and after matched filtering;

[0039] Figure 2 is a flowchart of the anti-interference DTOF ranging method in an embodiment of the present invention;

[0040] Figure 3 is a ranging schematic diagram of a multi-target scenario in an embodiment of the present invention;

[0041] Figure 4 is a schematic diagram of differentiating SPAD pixels corresponding to different objects in the grayscale image mode in an embodiment of the present invention;

[0042] Figure 5 is a ranging principle diagram of a target object in the ranging mode in an embodiment of the present invention;

[0043] Figure 6 is a structural diagram of the anti-interference DTOF ranging device in an embodiment of the present invention. Detailed Embodiments

[0044] In order to make the technical problems, technical solutions and beneficial effects to be solved by the embodiments of the present invention clearer, the present invention will be further described in detail below in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0045] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, the connection can be for a fixing function or for a circuit connection function.

[0046] It should be understood that the orientation or positional relationship indicated by terms such as "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0047] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present invention, "a plurality of" means two or more unless otherwise specifically defined.

[0048] The fusion ranging method provided by the embodiments of the present invention is applied to a ranging system based on the time of flight (TOF) technology, in which an anti-interference DTOF ranging device is carried. The anti-interference DTOF ranging device at least includes a pixel array including a plurality of SPAD pixels; a mode setting module for setting a grayscale mode and a ranging mode, wherein the resolution in the grayscale mode is higher than that in the ranging mode; an exposure control module for, in the grayscale mode, turning on the pixel array to perform a first exposure on all objects in the field of view to obtain a corresponding grayscale image; and identifying the interfering SPAD pixels in the pixel array according to the grayscale image, the interfering SPAD pixels corresponding to non-target objects in the detection field of view; and in the ranging mode, turning off the interfering SPAD pixels and performing a second exposure on the target object in the field of view through the remaining turned-on SPAD pixels to obtain corresponding original histogram data; and a data processing module for calculating the distance information of the target object according to the original histogram data.

[0049] In the existing DTOF ranging system, there is still a problem that multiple valid signals interfere with each other, resulting in inaccurate measurement. Since the original histogram needs to go through matched filtering during depth calculation, the signal features are amplified through convolution operation to suppress noise, and then the region information of the effective echo is obtained through peak searching to finally calculate the depth result. Therefore, when there are two or more objects that are relatively close to each other in the field of view of the corresponding pixel, such as Figure 1As shown, signals that are relatively close to each other may cause different signal peaks to merge with each other, resulting in the convolution histogram obtained after matched filtering being merged into a single signal peak and including multiple distance information. Eventually, an incorrect depth value is calculated, leading to inaccurate distance detection. Therefore, the following describes how to solve this problem through an anti-interference DTOF ranging method applied to the above anti-interference DTOF ranging device to avoid mutual interference between effective signal peaks and improve ranging accuracy.

[0050] As Figure 2 shown, Figure 2 is a flowchart of an anti-interference DTOF ranging method in an embodiment of the present invention. The method specifically includes the following steps:

[0051] S201. Set the grayscale image mode and the ranging mode, where the resolution in the grayscale image mode is higher than the resolution in the ranging mode.

[0052] In this embodiment, the sensor is provided with a grayscale image mode and a ranging mode with different resolutions, where the resolution in the grayscale image mode is higher than the resolution in the ranging mode. Specifically, the pixel array includes several SPAD pixels, and the switches of each SPAD pixel can be independently controlled. In the grayscale image mode, detection data is output with a smaller number of SPAD pixels as the minimum detection unit, so as to obtain a grayscale image with a higher resolution to better distinguish different objects in the field of view.

[0053] In one embodiment, in the grayscale image mode, grayscale image data is output with a single SPAD pixel as the minimum detection unit;

[0054] In the ranging mode, raw histogram data is output with a pixel composed of multiple SPAD pixels as the minimum detection unit.

[0055] In this embodiment, in the grayscale image mode, grayscale image data is output with a single SPAD pixel as the minimum detection unit, so as to achieve the output of grayscale image data with the highest resolution; while in the ranging mode, multiple SPAD pixels are combined into a single pixel as the minimum detection unit to output raw histogram data. For example, combination methods such as 2x2 or 3x3 are used, which improves the photosensitivity efficiency of the sensor while achieving accurate ranging.

[0056] As Figure 3In the multi-target ranging scenario shown, that is, there are at least two objects in the field of view, and the distances between different objects and the sensor are different. Assuming that in the ranging mode, 3x3 is merged into one pixel, if the sensor depth resolution is 192x256 pixels, then the entire pixel array has 576x768 SPAD pixels. And if the angular resolution of one pixel is 0.5°x0.5°, then the angular resolution of the corresponding SPAD pixel is approximately 0.17°x0.17°. That is, in the grayscale mode, it has a higher photon count resolution, and outputs grayscale image data with smaller angular resolution SPAD pixels to more accurately distinguish different objects in the field of view, thereby avoiding interference between signals of different objects.

[0057] S202. In the grayscale mode, turn on the pixel array to perform the first exposure on all objects in the field of view to obtain the corresponding grayscale image.

[0058] In this embodiment, when performing the first exposure, the sensor is switched to the grayscale mode, and all SPADs in the pixel array are turned on to expose all objects in the field of view. Specifically, all SPAD pixels in the pixel array are controlled to be turned on, and preferably each SPAD pixel outputs the corresponding grayscale image data separately, so as to obtain a grayscale image with the highest resolution, such as 576x768 exemplified in the above embodiment. Obtaining a high-resolution grayscale image through the grayscale mode before ranging enables, when there are two objects with relatively close distances in the field of view, to identify and distinguish different objects based on the higher-resolution grayscale image, providing a reliable identification basis for filtering out the signals of interfering objects.

[0059] S203. Confirm the interfering SPAD pixels in the pixel array according to the grayscale image, and the interfering SPAD pixels correspond to non-target objects in the detection field of view.

[0060] In this embodiment, based on the high resolution of the grayscale mode, the regional positions of different objects in the grayscale image can be distinguished more accurately. Through the position mapping relationship between each SPAD pixel in the pixel array and the grayscale image, combined with the regional positions of different objects in the grayscale image, the SPAD pixels used to detect different objects in the field of view in the pixel array can be accurately distinguished. For example, when the grayscale image data is output with a single SPAD pixel as the minimum detection unit in the grayscale mode, each SPAD pixel in the pixel array corresponds one-to-one with each pixel in the grayscale image, that is, each pixel position in the grayscale image corresponds to a SPAD pixel. Therefore, based on the position of the non-target object in the high-resolution grayscale image, the interfering SPAD pixels corresponding to detecting non-target objects in the pixel array can be accurately determined, thereby avoiding the interference brought by the detection results of interfering SPAD pixels in the subsequent detection process.

[0061] Such as Figure 3 andFigure 4 As shown, when there are two objects, target 1 and target 2, in the field of view, the SPAD pixels corresponding to the two targets can be distinguished based on the positions of the two targets in the grayscale image. That is, the SPAD pixels labeled 1 correspond to detecting target 1, and the SPAD pixels labeled 2 correspond to detecting target 2. Based on different requirements of the ranging application, such as detecting the distance of the farthest object or the nearest object, etc., the SPAD pixels corresponding to target 1 or target 2 can be determined as interfering SPAD pixels.

[0062] S204. In the ranging mode, turn off the interfering SPAD pixels, and perform a second exposure on the target object in the field of view through the remaining turned-on SPAD pixels to obtain corresponding original histogram data.

[0063] S205. Calculate the distance information of the target object according to the original histogram data.

[0064] In this embodiment, after determining the interfering SPAD pixels used to detect non-target objects in the pixel array, the interfering SPAD pixels are turned off in the ranging mode, so as to avoid the interference caused by the interfering SPAD pixels detecting signals of non-target objects. Specifically, the corresponding interfering SPAD pixels can be turned off before, after, or simultaneously when switching to the ranging mode. This embodiment does not limit this. In the ranging mode, a second exposure is performed on the target object in the field of view based on the remaining turned-on SPAD pixels.

[0065] Specifically, the target object is the object closest to the distance sensor in the field of view. For example, Figure 3 As shown, when the ranging application pays more attention to the object at a close distance, at this time, the object closest to the distance sensor, that is, target 1, is used as the target object, and the object farther from the distance sensor, that is, target 2, is a non-target object. After confirming the interfering SPAD pixels corresponding to detecting target 2 ( Figure 4 the SPAD pixels labeled 2 in Figure 5 ) in the grayscale image, the interfering SPAD pixels are turned off in the ranging mode. As shown in (a) of Figure 5 , a second exposure is performed on target 1 based on the remaining SPAD pixels labeled 1 to obtain corresponding original histogram data. As shown in (b) of Figure 5 , since the interfering SPAD pixels for detecting non-target objects are turned off, compared with the histogram in Figure 1 , the signal peak of the non-target object, that is, target 2, will not appear in the detected original histogram data at this time. The fusion phenomenon between the signal peaks of different objects is eliminated, and the original histogram data without interference is obtained. The non-interfering original histogram data is subjected to matched filtering and peak searching processing, and the distance information of the target object can be calculated based on the peak time bin. By eliminating the signal interference of non-target objects, the inaccurate measurement caused by the mutual interference of signals between different objects is effectively avoided, and the ranging accuracy is improved.

[0066] In one embodiment, step S202 includes:

[0067] In the grayscale mode, turn on the pixel array to receive the optical signals reflected back by all objects within the field of view;

[0068] Perform photon counting on the received optical signals through each SPAD pixel in the pixel array to obtain the photon count value output by each SPAD pixel;

[0069] Use the photon count value of each SPAD pixel as the grayscale value of the corresponding SPAD to generate the grayscale image.

[0070] In this embodiment, when the first exposure is performed, the sensor operates in the grayscale mode. The pixel array is used to receive the optical signals reflected back by all objects within the field of view during the exposure time. As Figure 3 shown, all SPAD pixels in the pixel array are turned on to receive the optical signals reflected back by target 1 and target 2. At this time, in the grayscale mode, there is no need to obtain the distance information of the objects. Therefore, each SPAD pixel does not need to output histogram data with time information. Instead, photon counting is directly performed based on the received optical signals to obtain the photon count value output by each SPAD pixel. This photon count value can reflect the strength of the optical signals reflected back by different objects. For example, the echo intensity of the distant target 2 is weaker than that of the near target 1. Therefore, the photon count value of each SPAD pixel is used as the grayscale value of the corresponding SPAD to generate the corresponding grayscale image. This enables different objects and their corresponding SPAD pixels to be directly distinguished by the signal intensity in the high-resolution grayscale image, and without collecting time information, it also saves computing and storage resources and improves the ranging efficiency.

[0071] In one embodiment, step S203 includes:

[0072] Distinguish different objects in the field of view according to the grayscale values at different positions in the grayscale image, and determine the non-target objects among all objects;

[0073] Determine the pixel positions in the pixel array corresponding to the non-target objects and mark them as interfering SPAD pixels.

[0074] In this embodiment, since the gray values at different positions in the grayscale image are the photon count values output by the corresponding SPAD pixels, which can reflect the echo intensities of different objects, different objects in the field of view can be accurately distinguished based on the gray values at different positions in the high-resolution grayscale image. Specifically, the larger the gray value of the SPAD in the grayscale image, the closer the object is to the distance sensor in the field of view; the smaller the gray value of the SPAD in the grayscale image, the farther the object is from the distance sensor in the field of view, so that different objects in the field of view can be quickly and accurately distinguished after the first exposure.

[0075] Then, non-target objects are further determined among all the objects. Specifically, the positional relationship between the non-target object and the target object is set in advance according to the requirements of the ranging application. For example, when the ranging application pays more attention to the close-range objects, the positional relationship between the non-target object and the target object can be set such that the target object is closer; conversely, the target object can be set to be farther away, etc. When determining the non-target object, the pre-configured positional relationship is obtained, which can be the default configuration or the configuration temporarily changed by the user. The non-target object is determined among all the objects according to the positional relationship. For example, if the pre-configured positional relationship is that the target object is closer, the object that is farther from the distance sensor and has a weaker signal is determined as the non-target object. Through the position mapping relationship between each SPAD pixel in the pixel array and the grayscale image, the pixel positions corresponding to the non-target object can be determined in the pixel array and marked as interfering SPAD pixels.

[0076] As Figure 4 shown, there are two objects in the field of view. The distance d1 between target 1 and the sensor is less than the distance d2 between target 2 and the sensor. After the first exposure, the signal intensity output by the SPAD pixel labeled 2 in the grayscale image is less than the signal intensity output by the SPAD pixel labeled 1. Then, it can be distinguished that the SPAD pixel labeled 2 corresponds to detecting the distant target 2, while the SPAD pixel labeled 1 corresponds to detecting the close-range target 1. Based on the pre-configured positional relationship, the SPAD pixel labeled 2 can be determined as an interfering SPAD pixel. Thus, through a higher-resolution grayscale image, SPAD pixels corresponding to different objects can be distinguished with a smaller angular resolution, and then the interfering SPAD pixels can be turned off during ranging to eliminate the signal interference caused by them.

[0077] In one embodiment, step S204 includes:

[0078] In the ranging mode, turn off the interfering SPAD pixels, and receive the optical signals reflected back by the target objects in the field of view through the remaining turned-on SPAD pixels;

[0079] Merge every m*n active SPAD pixels into one pixel, and perform time-of-flight statistics on the received optical signal to obtain the original histogram data output by each pixel, where m≥2 and / or n≥2.

[0080] In this embodiment, switch to the ranging mode for the second exposure. At this time, the interfering SPAD pixels corresponding to detecting non-target objects are turned off, and the remaining active SPAD pixels correspond to detecting target objects in the field of view. Therefore, the remaining active SPAD pixels receive the optical signal reflected by the target object during the exposure time. When outputting the original histogram data, to improve the photosensitive efficiency of ranging, merge every m*n active SPAD pixels into one pixel, where m≥2 and / or n≥2. For example, merge multiple SPAD pixels into one pixel in merging ways such as 2*2, 3*3, 3*1, 1*4, etc. to perform time-of-flight statistics, that is, the timing circuit (TDC) counts on the corresponding time bins based on the time-of-flight of the optical signal received by each pixel each time, so as to obtain the original histogram data of each pixel. At this time, the obtained original histogram data does not have the detection results of interfering SPAD pixels, avoiding the mutual interference of effective signals between different objects and effectively improving the ranging accuracy.

[0081] It should be noted that there is not necessarily a certain sequence among the above steps. Those of ordinary skill in the art can understand from the description of the embodiments of the present invention that in different embodiments, the above steps can have different execution sequences, that is, they can be executed in parallel or exchanged, etc.

[0082] The present invention also correspondingly provides an anti-interference DTOF ranging device, as Figure 6 shown Figure 6For the structural diagram of an anti-interference DTOF ranging device in an embodiment of the invention, it includes a pixel array 601, a mode setting module 602, an exposure control module 603, and a data processing module 604. The pixel array 601, the mode setting module 602, and the data processing module 604 are all connected to the exposure control module 603. The pixel array 601 includes a plurality of SPAD pixels; the mode setting module 602 is used to set a grayscale mode and a ranging mode, where the resolution in the grayscale mode is higher than that in the ranging mode; the exposure control module 603 is used to, in the grayscale mode, turn on the pixel array to perform a first exposure on all objects in the field of view to obtain a corresponding grayscale image; and confirm the interfering SPAD pixels in the pixel array according to the grayscale image, where the interfering SPAD pixels correspond to non-target objects in the detection field of view; and in the ranging mode, turn off the interfering SPAD pixels, and perform a second exposure on the target object in the field of view through the remaining turned-on SPAD pixels to obtain corresponding original histogram data; the data processing module 604 is used to calculate the distance information of the target object according to the original histogram data. Since the above method embodiment has introduced the anti-interference DTOF ranging process in detail, for details, reference can be made to the corresponding method embodiment above, and details are not described here.

[0083] The invention also correspondingly provides an electronic device, which includes the above-mentioned anti-interference DTOF ranging device. Since the above method embodiment has introduced the anti-interference DTOF ranging process in detail, for details, reference can be made to the corresponding method embodiment above, and details are not described here.

[0084] In summary, the invention provides an anti-interference DTOF ranging method, device, and electronic device. The method includes: setting a grayscale mode and a ranging mode, where the resolution in the grayscale mode is higher than that in the ranging mode; in the grayscale mode, turn on the pixel array to perform a first exposure on all objects in the field of view to obtain a corresponding grayscale image; confirm the interfering SPAD pixels in the pixel array according to the grayscale image, where the interfering SPAD pixels correspond to non-target objects in the detection field of view; in the ranging mode, turn off the interfering SPAD pixels, and perform a second exposure on the target object in the field of view through the remaining turned-on SPAD pixels to obtain corresponding original histogram data; calculate the distance information of the target object according to the original histogram data. By distinguishing non-target objects in the field of view with a high-resolution grayscale image and turning off the corresponding interfering SPAD pixels, interference caused by signal peaks of non-target objects can be avoided in the ranging mode, effectively improving the ranging accuracy.

[0085] The above content is a further detailed description of the present invention in combination with specific preferred embodiments. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several equivalent substitutions or obvious variations can be made, and if the performance or use is the same, they should all be regarded as belonging to the protection scope of the present invention.

Claims

1. An anti-interference DTOF ranging method, characterized in that: The steps include: Setting a grayscale image mode and a distance measurement mode, wherein the resolution in the grayscale image mode is higher than the resolution in the distance measurement mode; In the grayscale image mode, the pixel array is turned on to perform a first exposure on all objects in the field of view to obtain a corresponding grayscale image; Confirming an interfering SPAD pixel in the pixel array according to the grayscale image, wherein the interfering SPAD pixel corresponds to a non-target object in the detection field of view; In the ranging mode, the interfering SPAD pixels are turned off, and the target object in the field of view is exposed for a second time through the remaining turned-on SPAD pixels to obtain corresponding original histogram data; The distance information of the target object is calculated based on the original histogram data.

2. The anti-interference DTOF ranging method according to claim 1, characterized in that: In the grayscale image mode, grayscale image data is outputted with a single SPAD pixel as the minimum detection unit; In the distance measurement mode, the original histogram data is outputted with a pixel composed of a plurality of SPAD pixels as the minimum detection unit.

3. The anti-interference DTOF ranging method according to claim 1, characterized in that: In the grayscale image mode, the pixel array is turned on to perform a first exposure on all objects in the field of view to obtain a corresponding grayscale image, including: In the grayscale mode, the pixel array is turned on to receive light signals reflected by all objects in the field of view; Performing photon counting on the received light signal by each SPAD pixel in the pixel array to obtain a photon counting value output by each SPAD pixel; The photon count value of each SPAD pixel is used as the grayscale value of the corresponding SPAD to generate the grayscale image.

4. The anti-interference DTOF ranging method according to claim 1, characterized in that: The step of confirming the interfering SPAD pixel in the pixel array according to the grayscale image comprises: Differentiate different objects in the field of view according to the grayscale values ​​at different positions in the grayscale image, and determine non-target objects among all the objects; The pixel positions corresponding to the non-target objects in the pixel array are determined and marked as interfering SPAD pixels.

5. The anti-interference DTOF ranging method according to claim 4, characterized in that: The distinguishing different objects in the field of view according to the grayscale values ​​at different positions in the grayscale image specifically refers to: A SPAD with a larger grayscale value in the grayscale image corresponds to an object that is closer to the sensor in the field of view; The smaller the grayscale value of the SPAD in the grayscale image, the corresponding object is farther away from the sensor in the field of view.

6. The anti-interference DTOF ranging method according to claim 5, characterized in that: The determining of non-target objects among all objects specifically includes: A pre-configured positional relationship between the non-target object and the target object is acquired, and the non-target object is determined among all objects according to the positional relationship.

7. The anti-interference DTOF ranging method according to claim 1, characterized in that: In the ranging mode, the interfering SPAD pixel is turned off, and the target object in the field of view is exposed for a second time through the remaining turned-on SPAD pixel to obtain corresponding original histogram data, including: In the ranging mode, the interfering SPAD pixel is turned off, and the light signal reflected by the target object in the field of view is received by the remaining turned-on SPAD pixel; Every m*n turned-on SPAD pixels are combined into one pixel, and the flight time statistics of the received light signal are performed to obtain the original histogram data output by each pixel, where m≥2 and / or n≥2.

8. The anti-interference DTOF ranging method according to any one of claims 1 to 7, characterized in that: The target object is specifically: an object closest to the sensor in the field of view.

9. An anti-interference DTOF ranging device, characterized in that: include: A pixel array including a plurality of SPAD pixels; A mode setting module, used to set a grayscale image mode and a distance measurement mode, wherein the resolution in the grayscale image mode is higher than the resolution in the distance measurement mode; An exposure control module, used for, in the grayscale image mode, turning on the pixel array to perform a first exposure on all objects in the field of view to obtain a corresponding grayscale image; and confirming an interfering SPAD pixel in the pixel array according to the grayscale image, wherein the interfering SPAD pixel corresponds to a non-target object in the detection field of view; And in the ranging mode, turning off the interfering SPAD pixels, and performing a second exposure on the target object in the field of view through the remaining turned-on SPAD pixels to obtain corresponding original histogram data; The data processing module is used to calculate the distance information of the target object according to the original histogram data.

10. An electronic device, characterized in that: It includes the anti-interference DTOF ranging device as described in claim 9.

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