A ranging method, device and depth sensor with error compensation

Abstract

The application provides a ranging method, device and depth sensor with error compensation, the method comprising: rough ranging a target in a rough measurement mode, outputting histogram data of the rough ranging, confirming a time bin corresponding to a rough distance of the target, and obtaining the rough distance of the target; in the rough measurement mode, counting the number of received photons from the start of reception, and when the number of counted received photons reaches a preset threshold, recording the time at this moment as a full-counting detection duration; fine ranging the target in a fine measurement mode, starting fine ranging from the time bin corresponding to the rough distance, and obtaining a fine distance of the target; calculating a corresponding error value according to the full-counting detection duration; and calculating the distance of the target according to the rough distance, the fine distance and the error value. The full-counting detection duration is recorded to represent the error value during ranging, error compensation can be achieved without transmitting complete histogram data, and the ranging accuracy is improved without losing the ranging efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of distance detection technology, and in particular to a ranging method and device with error compensation and a depth sensor. BACKGROUND

[0002] At present, the commonly used dTOF (direct time of flight) technology in the field of ranging is to measure the flight time required for the returned light by emitting pulsed light in a histogram manner, and then to realize depth detection, i.e. distance measurement, which is widely used in the fields of three-dimensional modeling, portable electronic devices, AR / VR, unmanned aerial vehicles, self-driving cars, etc.

[0003] However, the ranging method using the histogram will cause the number of received photons to rapidly increase when measuring high-reflectivity objects or close-range objects, resulting in the entire measurement waveform being closer to the front end, and thus causing the ranging to be closer, which causes the walk error problem.

[0004] To solve the walk error problem, the traditional solution is to analyze the complete histogram to realize error compensation. However, this way of transmitting the complete histogram has a large amount of data transmission and a long data processing time, which will result in low ranging efficiency. SUMMARY

[0005] In view of the above deficiencies of the prior art, the present application aims to provide a ranging method and device with error compensation and a depth sensor to compensate for ranging errors without sacrificing ranging efficiency and to improve ranging accuracy.

[0006] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] The present application provides a ranging method with error compensation in a first aspect, comprising the following steps:

[0008] Coarse ranging of the target is performed in a coarse measurement mode, histogram data of the coarse ranging is output, the time bin corresponding to the coarse distance of the target is confirmed, and thus the coarse distance of the target is obtained;

[0009] In the coarse measurement mode, the number of received photons is accumulated from the start of reception, and when the accumulated number of received photons reaches a preset threshold, the time at this moment is recorded as the full-count detection time;

[0010] Fine ranging of the target is performed in a fine measurement mode, and the fine ranging is started from the time bin corresponding to the coarse distance, and thus the fine distance of the target is obtained;

[0011] According to the full-count detection time, an error value corresponding thereto is calculated;

[0012] The target distance is calculated according to the coarse distance of the target, the fine distance of the target and the error value.

[0013] In an embodiment, the error value is calculated according to the full-count detection duration, and the calculation method comprises:

[0014] An error compensation function is acquired, and the error compensation function is used to describe the relationship between the full-count detection duration and the error value.

[0015] The error value corresponding to the current output full-count detection duration is calculated according to the error compensation function.

[0016] In an embodiment, the generation method of the error compensation function comprises:

[0017] Sample data in different ranging environments is collected, and the sample data comprises full-count detection duration samples and error samples.

[0018] The relationship between the full-count detection duration and the error value is polynomially fitted according to the sample data, and the error compensation function is generated.

[0019] In an embodiment, the different ranging environments comprise different reflectivity of measured objects and different measurement distances.

[0020] In an embodiment, the greater the full-count detection duration, the smaller the error value; the smaller the full-count detection duration, the greater the error value; the error value is a distance value, and the full-count detection duration is a time value.

[0021] In an embodiment, the coarse ranging of the target in the coarse measurement mode outputs histogram data of the coarse ranging, and the coarse distance of the target is obtained by confirming the time bin corresponding to the coarse distance of the target, and the coarse ranging of the target in the coarse measurement mode comprises:

[0022] The detection light is emitted to the target.

[0023] The coarse histogram of a single pixel is acquired with a first accuracy.

[0024] The coarse histogram is peak-searched, and the coarse time bin corresponding to the peak value is output, so that the coarse distance of the target is obtained.

[0025] In an embodiment, the fine ranging of the target in the fine measurement mode starts from the time bin corresponding to the coarse distance of the target to perform the fine ranging, and the fine distance of the target is obtained, and the fine ranging of the target in the fine measurement mode comprises:

[0026] The detection light is emitted to the target.

[0027] Start from the rough time bin corresponding to the rough distance, start fine ranging with the second precision, and obtain a fine histogram of a single pixel, the second precision being smaller than the first precision;

[0028] Peak searching is performed on the fine histogram, and a fine time bin corresponding to a peak value is output;

[0029] According to the fine time bin, a fine distance of the target is obtained.

[0030] The second aspect of the present application provides a ranging device with error compensation, comprising:

[0031] The ranging module is configured to perform rough ranging on the target in a rough ranging mode, output histogram data of rough ranging, confirm a time bin corresponding to a rough distance of the target, and thus obtain the rough distance of the target; and perform fine ranging on the target in a fine ranging mode, start fine ranging from the time bin corresponding to the rough distance, and obtain a fine distance of the target;

[0032] The counting module is configured to, in the rough ranging mode, count the number of received photons from the start of reception, and when the number of accumulated received photons reaches a preset threshold, record the time at this moment as a total counting detection time length;

[0033] The error calculation module is configured to calculate a corresponding error value according to the total counting detection time length;

[0034] The distance calculation module is configured to calculate a target distance according to the rough distance of the target, the fine distance of the target, and the error value.

[0035] The third aspect of the present application provides a depth sensor comprising the ranging device with error compensation as described above.

[0036] The present application has the following beneficial effects: the present application provides a ranging method, device and depth sensor with error compensation, which records a total counting detection time length to represent an error value in a ranging mode with small data transmission amount combining rough ranging and fine ranging, and thus error compensation can be achieved without transmitting complete histogram data, so that the ranging accuracy is improved without losing the ranging efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0037] The present application will be further described below with reference to the accompanying drawings and embodiments, in which:

[0038] Figure 1 The present application has the following beneficial effects: the present application provides a ranging method, device and depth sensor with error compensation, which records a total counting detection time length to represent an error value in a ranging mode with small data transmission amount combining rough ranging and fine ranging, and thus error compensation can be achieved without transmitting complete histogram data, so that the ranging accuracy is improved without losing the ranging efficiency.

[0039] Figure 2 The present application has the following beneficial effects: the present application provides a ranging method, device and depth sensor with error compensation, which records a total counting detection time length to represent an error value in a ranging mode with small data transmission amount combining rough ranging and fine ranging, and thus error compensation can be achieved without transmitting complete histogram data, so that the ranging accuracy is improved without losing the ranging efficiency.

[0040] Figure 3 FIG. 8 is a schematic diagram of a full counting detection time length in an embodiment of the present application;

[0041] Figure 4 FIG. 9 is a fitting schematic diagram of an error compensation function in an embodiment of the present application;

[0042] Figure 5 FIG. 10 is a structural diagram of a ranging device with error compensation in an embodiment of the present application. DETAILED DESCRIPTION

[0043] In order to make the technical problems to be solved by the embodiments of the present application, technical solutions and beneficial effects more clearly, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0044] It should be noted that when an element is referred to as being "fixed" 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 fixing or for circuit communication.

[0045] It should be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the embodiments of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0046] In addition, the terms "first", "second" are only used for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0047] The ranging method with error compensation provided by the embodiment of the application is applied to a depth sensor based on a dTOF (direct time of flight) technology, and the depth sensor at least includes a controller, a transmitter and a receiver. The controller is connected with the transmitter and the receiver respectively. The transmitter is configured to emit a detection light beam to a target object, and at least part of the detection light beam is reflected by the target object to form reflected light. The receiver is configured to receive the reflected light reflected by the target object. The controller is configured to synchronously control the emission and reception of light, and perform histogram statistics on the photons received by the receiver in time bins. The histogram is used to calculate the time of flight of the photons, and then the depth value of the corresponding pixel is obtained, so that the distance measurement between the target object and the sensor is realized.

[0048] Specifically, the transmitter can include a driver and a light source, and 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), a picosecond laser, etc. The light source emits a detection light beam outward under the driving control of the driver. The detection light beam can be visible light, infrared light, ultraviolet light, etc. At least part of the detection light beam is emitted to the target object, and the reflected light generated by the reflection of at least part of the detection light beam on the target object is received by the receiver.

[0049] The receiver can include a pixel array and a receiving optical element, and the receiving optical element can be in the form of one or more combinations of a lens, a microlens array, a mirror, etc. The reflected light is received by the receiving optical element and guided to the pixel array. The pixel array includes a plurality of pixels for collecting photons. In an embodiment, the pixel array is composed of a plurality of single-photon avalanche photodiodes (SPADs). The SPAD can respond to an incident single photon and output a photon signal indicating the corresponding arrival time of the received photon at each SPAD. Of course, in other embodiments, photoelectric conversion devices such as avalanche photodiodes, photomultiplier tubes, silicon photomultiplier tubes, etc. can also be used.

[0050] At present, the depth sensor always faces the problem of walk error in distance measurement. The walk error problem refers to that when the dToF ranging method measures an object with high reflectivity or close distance, the histogram distribution will be more forward after a large number of photons are received at the receiving end, thereby causing the problem of measuring a distance that is too close.

[0051] In the traditional method, in order to solve the walk error problem, the depth sensor needs to output a complete statistical histogram, i.e. Figure 1In the statistical histogram shown in (a), without considering the walk error, the conventional method first finds the peak value full_peak from the complete statistical histogram, and the corresponding distance formula is distance = full_peak * bin_width * C / 2, where C is the speed of light, and bin_width is the time represented by each time bin in the statistical histogram. For example, if the obtained statistical histogram has 512 time bins, and each time bin has a time interval of 125 ps, and the peak value is located at the 250th time bin, then the distance calculation formula is: 250 * 125 x 10^-12 * 3 x 10^8 / 2 = 4.6875 m. Then, the walk error is compensated by performing signal analysis on the complete statistical histogram. In this way, the data transmission amount is quite large, for example, in the above example, 512 bytes of data are required, which increases the data transmission time and reduces the ranging efficiency.

[0052] Therefore, the present application describes how to solve this problem by applying the ranging method with error compensation to the dToF depth sensor, so that error compensation can be achieved without transmitting complete histogram data, while improving the ranging accuracy without losing the ranging efficiency.

[0053] As shown in Figure 2 , the present application is a ranging method with error compensation, and the flowchart of the method is shown in Figure 2 . The method specifically includes the following steps:

[0054] S201, rough ranging is performed on the target in a coarse measurement mode, histogram data of the rough ranging is output, the time bin corresponding to the rough distance of the target is confirmed, and thus the rough distance of the target is obtained.

[0055] In this embodiment, the distance value is obtained by combining the coarse measurement mode and the fine measurement mode. When ranging, the depth sensor first runs in the coarse measurement mode, and roughly locates the target in a larger range. The histogram data of the rough ranging is used to obtain the rough distance of the target and the corresponding time bin, which is specifically used as the starting position of data acquisition in the subsequent fine measurement mode.

[0056] In one embodiment, step S201 includes:

[0057] emitting probe light to the target;

[0058] acquiring a coarse histogram of a single pixel with a first precision;

[0059] performing peak searching on the coarse histogram, outputting the coarse time bin corresponding to the peak value, and thus obtaining the rough distance of the target.

[0060] In this embodiment, the depth sensor emits a probe light toward the target in coarse measurement mode to obtain a coarse histogram of a single pixel with a lower initial precision. The peak position is determined by finding the peak in the coarse histogram, and the coarse time bin (coarse_bin) corresponding to the peak is the corresponding coarse flight time. The coarse distance of the target is then calculated, which can be expressed as coarse_bin * bin_width * C / 2. Therefore, in coarse measurement mode, only one byte of coarse time bin data needs to be output, and the histogram data of the remaining time bins does not need to be output, which effectively saves the amount of data transmission.

[0061] S202. In coarse measurement mode, the number of received photons is counted from the start of reception. When the number of received photons reaches a preset threshold, the time at this moment is recorded as the full count detection duration.

[0062] Specifically, the total count detection time refers to the measurement time required to reach a certain photon count value, such as... Figure 3 As shown, the photon count value changes over time under different degrees of walk error. The shaded area indicates that the photon count value has reached a certain size, and the corresponding t1 and t2 are the full count detection time.

[0063] Because walk error becomes more severe when measuring objects with higher reflectivity or closer proximity, and objects with higher reflectivity or closer proximity cause the cumulative number of received photons to reach the preset threshold more quickly, i.e., the total count detection time is shorter. Figure 3 The drift error in (a) is less than Figure 3 The drift error in (b) is addressed here. Based on this, this embodiment further introduces a full-count detection time in the combined coarse and fine ranging method. Timing begins when the first photon is received in coarse measurement mode, and the cumulative number of received photons is counted. When the cumulative number of received photons reaches a preset threshold, the full-count detection time is obtained based on the timing time and used as a reference for error compensation. The preset threshold can be flexibly set according to actual measurement needs, for example, 255, 511, etc., and this embodiment does not limit this setting.

[0064] The specific threshold setting standard is as follows: the threshold setting needs to be moderate and reflect the changing pattern before the peak. If the threshold is set too high, the full count detection time may be after the peak timebox, thus failing to reflect the waveform changing pattern before the peak; if the threshold is set too low, the full count detection times will be relatively short, failing to reflect different ranging errors. For example, if a bin's full value is 255 (peak maximum 255), the threshold setting can be 255. In this case, the full count detection time will almost never be after the peak, and the difference in full count detection times between different histograms will be large enough to compensate for ranging errors.

[0065] S203, fine ranging on the target in a fine ranging mode, starting from a time bin corresponding to the coarse distance to obtain a fine distance of the target.

[0066] After the coarse ranging is completed and the time bin corresponding to the coarse distance is output, the depth sensor further switches to the fine ranging mode to perform fine ranging on the target, starting from the coarse bin to perform fine ranging in a certain measurement range to obtain the corresponding fine distance. For example, after coarse ranging, the coarse distance is obtained as 10 m, at this time, 10-12 m is amplified, and the fine distance is obtained as 0.3 m through fine ranging. The sum of the two is the target distance 10.3 m without considering the error. This coarse-fine combined ranging method has small data volume and fast processing speed.

[0067] In one embodiment, step S203 comprises:

[0068] emitting probe light to the target;

[0069] starting from a coarse time bin corresponding to the coarse distance, starting fine ranging with a second precision, obtaining a fine histogram of a single pixel, and the second precision is smaller than the first precision;

[0070] peak searching on the fine histogram to output a fine time bin corresponding to the peak;

[0071] obtaining a fine distance of the target according to the fine time bin.

[0072] In this embodiment, the depth sensor emits probe light to the target in the fine ranging mode, and then starts from a coarse time bin (coarse bin) corresponding to the coarse distance with a smaller second precision (smaller than the first precision) to obtain a fine histogram of a single pixel. The data output in the fine ranging mode is the histogram data near the true peak starting from the coarse time bin. Specifically, a preset amount of histogram data can be output, such as Figure 1 As shown in (b) of FIG. 10, the fine ranging obtains 128 histogram data of time bins starting from the coarse bin to construct a corresponding fine histogram, so that fine positioning is further performed in a certain measurement range interval on the basis of coarse positioning. Based on a fine time bin fine_peak corresponding to the peak in the fine histogram, a fine distance of the target is obtained, and the fine distance can be expressed as fine_peak*bin_width*C / 2.

[0073] Without considering the error, the measured distance of the target can be expressed as distance = (coarse_bin + fine_peak) * bin_width * C / 2. For example, the coarse bin is 200 when coarse ranging is performed, and then 128 time bins of fine histogram data are obtained when fine ranging is performed, where the peak value is located at the 50th time bin, and the time interval of each time bin is 125 ps. The calculation formula of the distance is (200 + 50) * 125 x 10^-12 * 3 x 10^8 / 2 = 4.6875 m, which is consistent with the actual distance of 4.6875 m. Figure 1 Compared with the complete histogram data (512 bytes) in (a), the combination of coarse and fine ranging significantly reduces the data transmission amount and improves the processing speed.

[0074] S204, calculating a corresponding error value according to the full counting detection time.

[0075] According to the characteristics of the full counting detection time, the full counting detection time and the error value are related to each other, so that the influence of the drift error on the ranging is accurately characterized by the correlation between the full counting detection time and the error value, and a corresponding error value is calculated, so that the purpose of outputting only part of the fine histogram data and the full counting detection time can also express the influence of the drift error is achieved, the amount of data required to be transmitted is greatly reduced, for example Figure 1 In (b), only 130 bytes of data transmission amount is required to achieve accurate distance calculation, avoiding the large amount of data and large load caused by directly transmitting the complete statistical histogram.

[0076] S205, calculating the target distance according to the coarse distance of the target, the fine distance of the target, and the error value.

[0077] In this embodiment, the target distance after error compensation can be expressed as distance = (coarse_bin + fine_peak) * bin_width * C / 2 - walk_error, where walk_error is the error value, which is a negative number, to reflect that the direction of the drift error is opposite to the direction of the depth detection, that is, the ranging result without correction error is closer to the direction of the depth sensor. Through the coarse and fine combined ranging method and error compensation, the large amount of data is avoided, and the measurement accuracy is improved.

[0078] In one embodiment, step S204 comprises:

[0079] obtaining a pre-generated error compensation function, the error compensation function being used to describe the relationship between the full counting detection time and the error value;

[0080] According to the error compensation function, an error value corresponding to the full-counting detection time length of the current output is calculated.

[0081] In this embodiment, when the error value corresponding to the full-counting detection time length is calculated, it is achieved by directly calling the pre-generated error compensation function, which describes the relationship between the full-counting detection time length and the error value. When calculating, the error compensation function is called, and the full-counting detection time length recorded during the current measurement is substituted into the function, so that the accurate error value corresponding to the current full-counting detection time length can be obtained efficiently and quickly, and the error value acquisition under the transmission of only part of the histogram data is realized.

[0082] In one embodiment, the generation method of the error compensation function includes:

[0083] Sample data under different ranging environments is collected, and the sample data includes full-counting detection time length samples and error samples.

[0084] According to the sample data, the relationship between the full-counting detection time length and the error value is polynomially fitted, and the error compensation function is generated.

[0085] In this embodiment, before the depth sensor formally measures the distance of the target, the relationship fitting is performed by collecting sample data under diversified ranging environments. Specifically, rich and diversified sample data is obtained under different reflectivity of the measured object and different measurement distances. The sample data refers to the full-counting detection time length sample and the error sample. The relationship between the full-counting detection time length and the error value is polynomially fitted, that is, a large number of real sample data collected under different conditions is fitted. As shown in FIG. 8, a fitting curve (curve of the error compensation function) close to the original curve formed by the real sample positions is obtained. Figure 4

[0086] ​Specifically, since the full counter detection time is smaller in the ranging scene with serious drift error problem and is larger in the ranging scene with less obvious drift error problem, the error value and the full counter detection time conform to a monotonous change relationship obtained by polynomial fitting, the larger the full counter detection time, the smaller the error value, and the smaller the full counter detection time, the larger the error value; the error value is a distance value, and the full counter detection time is a time value, in an embodiment, the error compensation function can be specifically represented as walk_error=k1*full_counter^3+k2*full_counter^2+k3*full_counter+k4, where walk_error is the error value, full_counter is the full counter detection time, and k1, k2, k3, and k4 are polynomial coefficients. Through the error compensation function generated and saved in advance, the depth sensor can accurately and efficiently express the corresponding error influence through the full counter detection time during actual ranging, so that distance measurement with small data quantity and high precision is realized.

[0087] It should be noted that the above steps do not necessarily have a certain sequence, and those skilled in the art can understand from the description of the embodiments of the present application that the above steps can have different execution sequences in different embodiments, that is, they can be executed in parallel, or they can be executed in exchange, and the like.

[0088] The present application also provides a ranging device with error compensation, as shown in Figure 5 Figure 5 is a structural diagram of the ranging device with error compensation in an embodiment of the present application, which comprises a ranging module 501, a counting module 502, an error calculation module 503, and a distance calculation module 504, and the ranging module 501, the counting module 502, the error calculation module 503, and the distance calculation module 504 are electrically connected in sequence. The ranging module 501 is used to perform rough ranging on a target in a rough measurement mode, output histogram data of rough ranging, confirm a time bin corresponding to a rough distance of the target, so as to obtain the rough distance of the target; and perform fine ranging on the target in a fine measurement mode, and start fine ranging from the time bin corresponding to the rough distance, so as to obtain a fine distance of the target; the counting module 502 is used to count the number of received photons from the start of receiving in the rough measurement mode, and record the time when the number of accumulated received photons reaches a preset threshold as a full counter detection time; the error calculation module 503 is used to calculate a corresponding error value according to the full counter detection time; and the distance calculation module 504 is used to calculate a target distance according to the rough distance of the target, the fine distance of the target, and the error value. Since the ranging process with error compensation has been described in detail in the above method embodiment, reference can be made to the corresponding method embodiment described above, and details are not described herein. ​

[0089] The application also provides a depth sensor comprising the error-compensated ranging device as described above. Since the above-mentioned method embodiments have described in detail the ranging process with error compensation applied to the depth sensor, reference can be made to the above-mentioned corresponding method embodiments, which will not be repeated here.

[0090] In summary, the application provides a ranging method, device and depth sensor with error compensation. The method comprises: performing coarse ranging on a target in a coarse ranging mode, outputting histogram data of the coarse ranging, and confirming a time bin corresponding to a coarse distance of the target, thereby obtaining the coarse distance of the target; in the coarse ranging mode, counting the number of received photons from the start of reception, and recording the time when the number of accumulated received photons reaches a preset threshold, as a full-counting detection time length; performing fine ranging on the target in a fine ranging mode, starting the fine ranging from the time bin corresponding to the coarse distance, and obtaining a fine distance of the target; calculating a corresponding error value according to the full-counting detection time length; and calculating the distance of the target according to the coarse distance of the target, the fine distance of the target and the error value. In the ranging mode with small data transmission amount combining coarse ranging and fine ranging, the full-counting detection time length is recorded to represent the error value during ranging, and error compensation can be achieved without transmitting complete histogram data, thereby improving the ranging accuracy without sacrificing the ranging efficiency.

[0091] The above is a further detailed description of the application in combination with specific preferred embodiments, and the specific implementation of the application should not be limited to these descriptions. For those skilled in the art to which the application belongs, without departing from the concept of the application, a number of equivalent alternatives or obvious variations can be made, and the performance or use is the same, which should be regarded as falling within the protection scope of the application.

Claims

1. A ranging method with error compensation, characterized by, The method comprises the following steps: coarse ranging of the target in a coarse ranging mode, outputting histogram data of the coarse ranging, confirming a time bin corresponding to a coarse distance of the target, and obtaining the coarse distance of the target; in the coarse ranging mode, timing is started from the time when the first photon is received, and the number of accumulated received photons is counted, and when the number of the accumulated received photons reaches a preset threshold, the timing time at this moment is recorded as a total count detection time length; fine ranging of the target in a fine ranging mode, starting the fine ranging from the time bin corresponding to the coarse distance as a starting point, and obtaining a fine distance of the target; calculating a corresponding error value according to the total count detection time length; calculating the distance of the target according to the coarse distance of the target, the fine distance of the target, and the error value.

2. The method of ranging with error compensation of claim 1, wherein, The method of calculating the corresponding error value according to the total count detection time length comprises: obtaining a pre-generated error compensation function, the error compensation function being used to describe the relationship between the total count detection time length and the error value; calculating the error value corresponding to the current output total count detection time length according to the error compensation function.

3. The method of ranging with error compensation of claim 2, wherein, The method of generating the error compensation function comprises: collecting sample data in different ranging environments, the sample data comprising total count detection time length samples and error samples; performing polynomial fitting on the relationship between the total count detection time length and the error value according to the sample data, and generating the error compensation function.

4. The method of ranging with error compensation of claim 3, wherein, The different ranging environments comprise different reflectivity of measured objects and different measurement distances.

5. The method of ranging with error compensation of claim 3, wherein, The greater the total count detection time length, the smaller the error value; the smaller the total count detection time length, the greater the error value; the error value is a distance value, and the total count detection time length is a time value.

6. The method of ranging with error compensation of claim 1, wherein, The method of coarse ranging of the target in the coarse ranging mode, outputting the histogram data of the coarse ranging, confirming the time bin corresponding to the coarse distance of the target, and obtaining the coarse distance of the target comprises: emitting detection light to the target; obtaining a coarse histogram of a single pixel with a first precision; performing peak searching on the coarse histogram, outputting a coarse time bin corresponding to a peak value, and obtaining the coarse distance of the target.

7. The method of ranging with error compensation of claim 6, wherein, The method of fine ranging of the target in the fine ranging mode, starting the fine ranging from the coarse time bin corresponding to the coarse distance as a starting point, and obtaining the fine distance of the target comprises: emitting detection light to the target; starting fine ranging with a second precision from the coarse time bin corresponding to the coarse distance as a starting point, obtaining a fine histogram of a single pixel, and the second precision is smaller than the first precision; performing peak searching on the fine histogram, outputting a fine time bin corresponding to a peak value; obtaining the fine distance of the target according to the fine time bin.

8. A ranging device with error compensation, characterized by, The method comprises: a ranging module, configured to perform coarse ranging of a target in a coarse ranging mode, output histogram data of the coarse ranging, confirm a time bin corresponding to a coarse distance of the target, and obtain the coarse distance of the target; and perform fine ranging of the target in a fine ranging mode, start the fine ranging from the time bin corresponding to the coarse distance as a starting point, and obtain a fine distance of the target. A counting module is configured to, in the coarse measurement mode, start timing from the time when the first photon is received, and count the number of accumulated received photons, and record the timing time at the moment when the number of accumulated received photons reaches a preset threshold value as a full-counting detection time length; An error calculating module is configured to calculate a corresponding error value according to the full-counting detection time length; A distance calculating module is configured to calculate the distance of the target according to the coarse distance of the target, the fine distance of the target and the error value.

9. A depth sensor, characterized by The ranging device with error compensation as claimed in claim 8 is provided.

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