WO2023000756A1 - Ranging method and apparatus, terminal, and non-volatile computer-readable storage medium - Google Patents

Abstract

Disclosed are a ranging method, a ranging apparatus (10), a terminal (100), and a non-volatile computer-readable storage medium (300). The ranging method comprises: acquiring a time of flight histogram; according to the time of flight histogram, determining a peak unit and multiple neighboring units from among time units; determining a time of flight according to a parameter value of the peak unit and parameter values of the multiple neighboring units; and, according to the time of flight and the speed of light, calculating a distance between a sensor and an object.

Description

Distance measuring method and device, terminal and non-volatile computer-readable storage medium

priority information

This application claims the priority and benefit of the patent application No. 202110817226.0 filed with the State Intellectual Property Office of China on July 20, 2021, which is hereby incorporated by reference in its entirety.

technical field

The present application relates to the technical field of distance measurement, and in particular to a distance measurement method, a distance measurement device, a terminal and a non-volatile computer-readable storage medium.

Background technique

Direct Time of Flight (dToF) is a ranging technology that calculates the distance between the object and the sensor by measuring the time difference between the transmitted signal and the signal reflected by the object. The moment at which the sensor receives the signal reflected back by the object is usually determined by means of a histogram.

Contents of the invention

Embodiments of the present application provide a ranging method, a ranging device, a terminal, and a non-volatile computer-readable storage medium.

The ranging method in the embodiment of the present application includes: obtaining a time-of-flight histogram; determining a peak unit and a plurality of neighboring units from the time unit according to the time-of-flight histogram; determining the time of flight; and calculating the distance between the sensor and the object based on the time of flight and the speed of light.

The ranging device in the embodiment of the present application includes an acquisition module, a retrieval module, a determination module, and a calculation module. The acquisition module can be used to acquire time-of-flight histograms. The retrieval module can be used to determine the peak unit and multiple neighboring units from the time unit according to the time-of-flight histogram. The determination module can be used to determine the flight time according to the parameter value of the peak unit and the parameter values of multiple neighboring units. The calculation module can be used to calculate the distance between the sensor and the object according to the time of flight and the speed of light.

The terminal in the embodiments of the present application includes one or more processors, memories, and one or more programs. Wherein, the one or more programs are stored in the memory and executed by the one or more processors, and the programs include instructions for executing the ranging method described in the embodiments of the present application. The ranging method includes: obtaining a time-of-flight histogram; determining a peak unit and a plurality of neighboring units from the time unit according to the time-of-flight histogram; determining the flight time according to the parameter value of the peak unit and the parameter values of the plurality of neighboring units; and Calculate the distance between the sensor and the object based on the time of flight and the speed of light.

A non-volatile computer-readable storage medium containing a computer program according to an embodiment of the present application. When the computer program is executed by one or more processors, the processors can implement the test described in the embodiment of the present application. distance method. The ranging method includes: obtaining a time-of-flight histogram; determining a peak unit and a plurality of neighboring units from the time unit according to the time-of-flight histogram; determining the flight time according to the parameter value of the peak unit and the parameter values of the plurality of neighboring units; and Calculate the distance between the sensor and the object based on the time of flight and the speed of light.

The ranging method, ranging device, terminal, and non-volatile computer-readable storage medium in the embodiments of the present application can determine the flight time according to the parameter value of the peak unit and the parameter values of multiple neighboring units, so as to obtain more accurate flight time time, thereby improving the ranging accuracy.

Additional aspects and advantages of embodiments of the application will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application.

Description of drawings

The above and/or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, wherein:

FIG. 1 is a schematic flowchart of a ranging method in some embodiments of the present application;

FIG. 2 is a schematic structural diagram of a terminal in some embodiments of the present application;

Fig. 3 is a schematic structural diagram of a ranging device in some embodiments of the present application;

4 is a schematic diagram of a time-of-flight histogram of some embodiments of the present application;

5 is a schematic diagram of a time-of-flight histogram of some embodiments of the present application;

6 is a schematic diagram of a time-of-flight histogram of some embodiments of the present application;

Figure 7 is a schematic diagram of a time-of-flight histogram of some embodiments of the present application;

FIG. 8 is a schematic flowchart of a ranging method in some embodiments of the present application;

FIG. 9 is a schematic diagram of a time-of-flight histogram of some embodiments of the present application;

FIG. 10 is a schematic flowchart of a ranging method in some embodiments of the present application;

FIG. 11 is a schematic flowchart of a ranging method in some embodiments of the present application;

FIG. 12 is a schematic flowchart of a ranging method in some embodiments of the present application;

FIG. 13 is a schematic flowchart of a ranging method in some embodiments of the present application;

FIG. 14 is a schematic flowchart of a ranging method in some embodiments of the present application;

FIG. 15 is a schematic flowchart of a ranging method in some embodiments of the present application;

Fig. 16 is a schematic diagram of a connection relationship between a computer-readable storage medium and a processor in some embodiments of the present application.

detailed description

Embodiments of the present application are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary, are only for explaining the embodiments of the present application, and should not be construed as limiting the embodiments of the present application.

Embodiments of the present application provide a ranging method, a ranging device 10 , a terminal 100 and a non-volatile computer-readable storage medium 300 .

The distance measuring method in the embodiment of the present application includes: obtaining a time-of-flight histogram, which represents the number of photons received by the sensor in each time unit; domain unit; determine the time of flight according to the parameter value of the peak unit and the parameter values of multiple neighboring units; and calculate the distance between the sensor and the object according to the time of flight and the speed of light.

In some embodiments, obtaining the time-of-flight histogram includes: obtaining a preset time period and a preset time resolution; determining a plurality of time units according to the time period and time resolution, and the time units are arranged sequentially on the time axis; The arrival time of each photon arriving at the sensor is obtained; the time unit corresponding to each photon is determined according to the arrival time; and the number of photons corresponding to each time unit is counted to establish a time-of-flight histogram.

In some embodiments, the resolution of each time unit in the time-of-flight histogram is the same.

In some embodiments, the time-of-flight histogram includes a region of interest and a region of non-interest, and the resolution of the time units of the region of interest is smaller than the resolution of the time units of the region of non-interest.

In some embodiments, determining the peak value unit and a plurality of neighboring units from the time unit according to the time-of-flight histogram includes: obtaining the photon count value corresponding to each time unit; determining the time unit corresponding to the maximum photon count value as a peak unit; and determining at least one time unit adjacent to the left side of the peak unit and at least one time unit adjacent to the right side of the peak unit in the time-of-flight histogram as neighborhood units.

In some embodiments, the neighborhood unit includes a left neighborhood unit located on the left side of the peak unit and a right neighborhood unit located on the right side of the peak unit, and the parameter value includes the resolution of the time unit, the photon count value corresponding to the time unit, and the sequence number in which the time unit appears in chronological order.

In some implementations, determining the flight time according to the peak unit and a plurality of neighboring units includes: obtaining the peak count value corresponding to the peak unit, the left count value corresponding to the left neighboring unit, and the right counting value corresponding to the right neighboring unit ; Determine the correction value according to the peak count value, left count value, right count value and preset correction parameters; and determine the flight time according to the resolution of the peak unit, the serial number of the peak unit and the correction value.

In some embodiments, the correction parameters include a first parameter, a second parameter and a third parameter, and determining the correction value according to the peak count value, the left count value, the right count value and preset correction parameters includes: according to the peak count value and the first parameter to obtain the weighted peak count value; obtain the weighted right count value according to the right count value and the second parameter; obtain the weighted left count value according to the left count value and the third parameter; obtain the first value between the right count value and the left count value A difference value; obtain a second difference value obtained after the weighted peak count value is sequentially differenced from the weighted right count value and the weighted left count value; and obtain a ratio between the first difference value and the second difference value, and determine the ratio as a correction value.

In some embodiments, determining the flight time according to the resolution of the peak unit, the serial number of the peak unit and the correction value includes: determining the corrected serial number of the peak unit according to the serial number of the peak unit and the corrected value, and determining the corrected serial number of the peak unit according to the corrected serial number and the corrected value of the peak unit. Determine the flight time by resolution; or determine the peak time according to the serial number and resolution of the peak unit, determine the correction time according to the correction value and resolution, and determine the flight time according to the peak time and correction time; or determine the peak value according to the serial number and correction value of the peak unit The corrected serial number of the unit, and the moment corresponding to the corrected serial number on the time-of-flight histogram is taken as the flight time.

The distance measuring device 10 of the embodiment of the present application includes: an acquisition module 11, the acquisition module 11 is used to acquire a time-of-flight histogram, and the time-of-flight histogram represents the number of photons received by the sensor in each time unit; a retrieval module 12, a retrieval module 12 is used for determining the peak unit and a plurality of neighborhood units from the time unit according to the time-of-flight histogram; Determination module 13, the determination module 13 is used for determining the flight time according to the parameter value of the peak unit and the parameter value of a plurality of neighborhood units; And a calculation module 14, the calculation module 14 is used to calculate the distance between the sensor and the object according to the time of flight and the speed of light.

The terminal 100 of the embodiment of the present application includes: one or more processors 30, a memory 20; and one or more programs, wherein one or more programs are stored in the memory 20 and executed by the one or more processors 30 , the program includes instructions for executing the ranging method in any one of the above-mentioned embodiments.

In some embodiments, the processor 30 is configured to: obtain a preset time period and a preset time resolution; determine multiple time units according to the time period and time resolution, and the time units are arranged in sequence on the time axis; obtain each The arrival time of photons arriving at the sensor; determining the time unit corresponding to each photon according to the arrival time; and counting the number of photons corresponding to each time unit to establish a time-of-flight histogram.

In some embodiments, the processor 30 is configured to: obtain the photon count value corresponding to each time unit; determine the time unit corresponding to the maximum photon count value as the peak unit; At least one adjacent time unit and at least one adjacent time unit on the right side of the peak unit are determined as neighborhood units.

In some embodiments, the processor 30 is configured to: obtain the peak count value corresponding to the peak value unit, the left count value corresponding to the left neighbor unit, and the right count value corresponding to the right neighbor unit; , the right count value and the preset correction parameters to determine the correction value; and determine the flight time according to the resolution of the peak unit, the serial number of the peak unit and the correction value.

In some embodiments, the processor 30 is configured to: obtain the weighted peak count value according to the peak count value and the first parameter; obtain the weighted right count value according to the right count value and the second parameter; obtain the weighted right count value according to the left count value and the third parameter Weighting the left count value; obtaining the first difference between the right count value and the left count value; obtaining the second difference between the weighted peak count value and the weighted right count value and the weighted left count value; and obtaining the first A ratio of the difference to the second difference is determined as the correction value.

In some embodiments, the processor 30 is used to: determine the correction serial number of the peak unit according to the serial number of the peak unit and the correction value, and determine the flight time according to the correction serial number and the resolution of the peak unit; or determine the time of flight according to the serial number and resolution of the peak unit determine the peak time according to the correction value and resolution, determine the flight time according to the peak time and correction time; or determine the correction number of the peak unit according to the number of the peak unit and the correction value, and put the correction number on the time-of-flight histogram The corresponding moment is taken as the flight time.

The non-volatile computer-readable storage medium 300 of the computer program 301 in the embodiment of the present application, when the computer program 301 is executed by one or more processors 30, makes the processor 30 implement the distance measuring method in any one of the above-mentioned embodiments .

An embodiment of the present application provides a ranging method. Please refer to Fig. 1, the ranging method of the embodiment of the present application includes:

01: Obtain the time-of-flight histogram, which represents the number of photons received by the sensor in each time unit;

02: Determine the peak unit and multiple neighboring units from the time unit according to the time-of-flight histogram;

03: Determine the flight time according to the parameter value of the peak unit and the parameter values of multiple neighboring units; and

04: Calculate the distance between the sensor and the object based on the flight time and the speed of light.

Referring to FIG. 2 , the embodiment of the present application further provides a terminal 100 , and the ranging method in the embodiment of the present application can be applied to the terminal 100 . Terminal 100 includes one or more processors 30, memory 20, and one or more programs. One or more programs are stored in the memory 20 and executed by one or more processors 30, and the programs include instructions for executing the ranging method of the embodiment of the present application. That is, when the processor 30 executes the program, the processor 30 can implement the methods in steps 01, 02, 03, and 04. That is, the processor 30 can be used to: obtain the time-of-flight histogram; determine the peak unit and multiple neighborhood units from the time unit according to the time-of-flight histogram; time of flight; and calculating the distance between the sensor and the object based on the time of flight and the speed of light.

In some implementations, the terminal 100 further includes a transmitting end 40 and a sensor 50 . The emitting end 40 is used to emit light beams, and the light beams contain multiple photons. The sensor 50 is used to receive photons reflected back from the object. Thus, the time-of-flight can be determined from the moment the light beam is emitted and the moment the sensor 50 receives the photon reflected back from the object.

Please refer to FIG. 2 and FIG. 3 , the embodiment of the present application further provides a distance measuring device 10 , and the distance measuring device 10 may be applied to a terminal 100 . The distance measuring device 10 includes an acquisition module 11 , a retrieval module 12 , a determination module 13 , and a calculation module 14 . The acquisition module 11 can be used to implement the method in 01, the retrieval module 12 can be used to implement the method in 02, the determination module 13 can be used to implement the method in 03, and the calculation module 14 can be used to implement the method in 04. That is, the acquiring module 11 can be used to acquire the time-of-flight histogram. The retrieval module 12 can be used to determine the peak unit and multiple neighboring units from the time unit according to the time-of-flight histogram. The determination module 13 can be used to determine the flight time according to the parameter value of the peak unit and the parameter values of multiple neighboring units. The calculation module 14 can be used to calculate the distance between the sensor 50 and the object according to the time of flight and the speed of light.

See Figures 1 through 3. Wherein, the time-of-flight is the time experienced by the photon from being emitted, reflected by the object, and received by the sensor 50. According to the time-of-flight, the distance between the sensor 50 and the object can be calculated by using the time-of-flight ranging method, namely

Where, d is the distance between the sensor 50 and the object, c is the speed of light, and t is the time of flight. Based on the principle of time-of-flight ranging, the distance between the emitting end 40 of the photon and the sensor 50 is as close as possible to ensure the round-trip distance of the photon, that is, the distance from the emitting end 40 of the photon to the object and the reflection of the photon from the object back to the sensor 50 as close as possible to ensure accurate ranging results.

Referring to FIG. 4 and FIG. 5 , the time-of-flight histogram represents the number of photons received by the sensor 50 in each time unit. Specifically, the time-of-flight histogram represents the number of photons received by the sensor 50 (as shown in FIG. 2 ) in each time unit after m times of statistics. For example, the number of photons is counted every time a preset measurement cycle is passed. In one count, if the sensor 50 receives a photon, the photon of the time unit at which the sensor 50 receives the photon (can be determined by a time stamp) is made The count value is increased by 1; if the sensor 50 does not receive photons in one count, the photon count value is not increased. In this way, the number of photons received by the sensor 50 in each time unit can be characterized according to the photon count value corresponding to each time unit.

In a time-of-flight histogram, the starting point of the time axis is the starting point of a measurement period, which is also the time at which photons are emitted. According to the principle of time-of-flight ranging, the time-of-flight can be determined according to the moment when the photon is emitted and the moment when the photon is received by the sensor 50 . However, the photons received by the sensor 50 are not necessarily photons reflected from objects, but may also be noise signals, such as photons existing in the environment (ambient light). Therefore, only counting the number of photons once cannot determine whether the photons received by the sensor 50 are photons reflected from objects. In the time-of-flight histogram, the number of photons received by the sensor 50 in each time unit can be obtained by counting the number of photons received by the sensor 50 in multiple measurement periods, and the photon count value corresponding to each time unit can reflect this at the same time. The energy value of the photon received by the time unit, that is, the light intensity. Please refer to FIG. 2 , the light beam emitted by the transmitting end 40 has relatively high energy (light intensity), and the energy of the light beam is much higher than that of the noise signal. Therefore, the light beam reflected back from the object also has higher energy (light intensity). In the time-of-flight histogram, the larger the photon count value corresponding to the time unit, the higher the light intensity corresponding to the time unit. There is also a higher probability that the statistical photon is a photon in the beam reflected back from the object.

Please refer to Fig. 4 and Fig. 5, specifically, in one embodiment, the time-of-flight histogram shown in Fig. 4 is a time-of-flight histogram obtained through 10 statistics, and the time-of-flight histogram shown in Fig. 5 is obtained through 100 times of statistics Obtained time-of-flight histogram. The horizontal axis of the time-of-flight histogram represents time, and the vertical axis represents the number of photons received by the sensor 50 . A time unit is a time scale on the abscissa time axis, and each time unit represents a period of time on the time axis. For example, the time-of-flight histogram includes 5 time units, and the two endpoints of the first time unit on the time axis are 0ns and 0.5ns respectively, then the first time unit represents the period between 0ns and 0.5ns on the time axis for a while. The two endpoints of the second time unit on the time axis are 0.5ns and 1.0ns respectively, then the second time unit represents a period of time between 0.5ns and 1.0ns on the time axis. By analogy, other time units are not listed here. In the time-of-flight histogram, each time unit is a statistical unit, the height of each time unit, that is, the ordinate corresponding to the time unit represents the number of photons received by the sensor 50 in this time unit after m times of statistics . For example, as shown in Figure 4, after 10 statistics, the ordinate corresponding to the third time unit is 5, which means that after 10 statistics, the sensor 50 received 5 photons, the photon count value corresponding to the third time unit is 5. For example, as shown in Figure 5, after 100 statistics, the ordinate corresponding to the fifth time unit is 52, which means that after 100 statistics, the sensor 50 received 52 photons, the photon count corresponding to the third time unit is 52.

In combination with the foregoing, the larger the photon count value corresponding to a time unit, the higher the light intensity corresponding to the time unit, and the higher the probability that the sensor 50 receives photons reflected back from the object in this time unit, based on the time unit The probability that the distance calculated by the determined flight time is the actual measured distance is also greater. Therefore, in order to obtain accurate flight time, it is necessary to determine the peak unit from multiple time units to determine the flight time based on the peak unit. Wherein, the peak unit is the time unit with the largest photon count value, that is, the time unit with the highest energy (light intensity).

However, the peak unit represents a time period when the sensor 50 receives the photons reflected back from the object, and it is impossible to determine which moment in the time period is the time when the sensor 50 receives the photons reflected back from the object. In some embodiments, the median moment of the time period represented by the peak unit may be determined as the moment when the sensor 50 receives a photon reflected back from the object. For example, in the histogram shown in Figure 5, the peak unit is the third time unit, which represents a period of time between the 1.0ns and the 1.5ns on the time axis, then the moment of 1.25ns is determined as the sensor 50 receiving the The moment a photon is reflected back by an object to calculate the time-of-flight. Based on the above-mentioned principle, when the moment when the sensor 50 receives photons is determined according to the peak unit, the smaller the range of the time period represented by the peak unit is, that is, the thinner the corresponding column of the peak unit (the narrower the width of the horizontal axis), then according to the The peak unit determines the more precisely the moment when the sensor 50 receives the photon reflected back from the object. Theoretically, in the limit case, when a peak unit represents a certain moment, this moment is the moment when the sensor 50 receives photons reflected back from the object. Due to the limitation of hardware circuit design, the time period represented by the time unit, that is, the time resolution of the time unit has a minimum value, thus resulting in the accuracy of the moment when the sensor 50 can receive the photons reflected back from the object according to the peak value unit. The degree is limited by the minimum time resolution of the time unit. When the time resolution of the time unit reaches the minimum, the accuracy of the time determined according to the time unit reaches the highest and cannot be further improved. In addition, if the time resolution of the time unit is too small, in order to ensure accurate ranging, the required photon counting statistics will be greatly increased, which may lead to a decrease in ranging efficiency.

The ranging method in the embodiment of the present application can determine the peak unit and multiple neighboring units from the time unit according to the time-of-flight histogram, and determine the flight time according to the parameter value of the peak unit and the parameter values of the multiple neighboring units. Wherein, the neighborhood unit is at least one time unit adjacent to the peak unit, and the parameter value may include the resolution of the time unit, the photon count value corresponding to the time unit, the serial number of the time unit in chronological order, and the like. For example, please refer to Fig. 5, the peak unit is the third time unit, then the second time unit and the fourth time unit can be used as the neighbor units corresponding to the peak unit. The peak unit is the time unit with the highest energy (light intensity), and the neighbor unit corresponding to the peak unit is often the time unit with higher energy (light intensity). On the basis of determining that the moment when the sensor 50 receives the photon reflected back from the object is within the peak unit, combined with the parameter value of the neighborhood unit, it can be further determined that the moment when the sensor 50 receives the photon reflected back from the object is closer to the neighbor on the left side. The domain unit is also the neighbor unit closer to the right.

For example, please refer to Figures 6 and 7. In the time-of-flight histograms shown in Figures 6 and 7, the 41st time unit is the peak unit, and the adjacent units corresponding to the peak unit include the left side of the 41st time unit. The 40th time unit and the 42nd time unit on the right side of the 41st time unit, t0 is the time corresponding to the midpoint of the peak unit along the horizontal axis. Assuming that the time resolution of the time unit is 0.5ns, combined with the speed of light, a photon can move 0.075m at 0.5ns, which is equivalent to a distance resolution of 0.075m when the time resolution is 0.5ns. From this, it can be calculated that the distance corresponding to the left end point of the peak unit is 3.000m, and the distance corresponding to the right end point of the peak unit is 3.075m. Since the peak unit represents a period of time on the time axis, the midpoint of the period, that is, the median moment of the peak unit, is usually taken to determine the flight time. The distance measurement result d1=3.0375m is calculated according to the flight time t1 determined at the median time of the peak unit. If the flight time t1 is determined only based on the peak unit, then when the value range of the real distance is [3.000m, 3.075m], no matter the real distance is any value within the range of [3.000m, 3.075m], according to the flight time t1 and The distance measurement results d1 calculated by the speed of light are all 3.0375m, and it is difficult to further calculate a more accurate distance when the time resolution of the time unit cannot be reduced.

The ranging method in the embodiment of the present application can determine the flight time according to the parameter value of the peak unit and the parameter values of multiple neighboring units, so as to determine a more accurate flight time, thereby improving the ranging accuracy.

Specifically, please refer to Figure 6. In the time-of-flight histogram shown in Figure 6, if the photon count value corresponding to the 40th time unit is greater than the photon count value corresponding to the 42nd time unit, the actual time-of-flight is likely to be at the peak On the left side of the median moment of the unit, after determining the flight time t2 according to the parameter value of the peak unit and the parameter values of multiple neighboring units, the distance d2 calculated according to the flight time t2 and the speed of light is within the range [3.0000m, 3.0375m) Within , that is, when the real distance is within the range [3.0000m, 3.0375m), d2 will be output as the distance measurement result. That is, the distance resolution corresponding to the ranging result d2 is at most 0.0375m, which is smaller than the distance resolution corresponding to the ranging result d1 at 0.075m; the corresponding time resolution is at most 0.25ns, which is smaller than the time resolution of the peak unit at 0.5ns.

Similarly, please refer to Figure 7, in the time-of-flight histogram shown in Figure 7, the photon count value corresponding to the 40th time unit is smaller than the photon count value corresponding to the 42nd time unit, then the highest peak of the peak unit has a high probability On the right side of the midpoint of the peak unit along the horizontal axis, after determining the flight time t3 according to the parameter value of the peak unit and the parameter values of multiple neighboring units, the distance d3 calculated according to the flight time t3 and the speed of light is within the range ( 3.0375m, 3.0750m], that is, when the real distance is within the range (3.0375m, 3.0750m], output d3 as the ranging result. That is, the distance resolution corresponding to the ranging result d3 is at most 0.0375m, It is smaller than the distance resolution corresponding to the ranging result d1, which is 0.075m; the corresponding time resolution is at most 0.25ns, which is smaller than the time resolution of the peak unit, which is 0.5ns.

According to the above, the distance resolution corresponding to the distance measurement result d2 and the distance measurement result d3 is smaller than the distance resolution corresponding to the distance measurement result d1, that is, the distance measurement result d2 and the distance measurement result d3 have Higher ranging accuracy. Therefore, the ranging accuracy is improved without reducing the actual time resolution of the time unit. The above-mentioned embodiments are only used to illustrate that the ranging method in the embodiments of the present application has the effect of improving the ranging accuracy, and the degree of improvement in the ranging accuracy of the ranging methods in the embodiments of the present application is not limited to the degree of improvement illustrated in the above-mentioned examples . That is, in the above embodiment, in the time-of-flight histograms shown in FIG. 6 and FIG. 7 , compared with the distance measurement result d1 , the distance measurement accuracy of the distance measurement result d2 and the distance measurement result d3 is at least doubled. The distance measurement method in the embodiment of the present application improves the distance measurement accuracy not limited to 2 times, but may also be 3 times, 4 times, or higher.

Further description will be made below in conjunction with the accompanying drawings.

Please refer to FIG. 8. In some embodiments, 01: Obtain a time-of-flight histogram, including:

011: Obtain a preset time period and a preset time resolution;

012: Determine multiple time units according to the time period and time resolution, and the time units are arranged in sequence on the time axis;

013: Obtain the arrival time of each photon arriving at the sensor 50;

014: Determine the time unit corresponding to each photon according to the arrival time; and

015: Count the number of photons corresponding to each time unit to create a time-of-flight histogram.

Please refer to FIG. 2 , in some implementation manners, the processor 30 may also be used to implement the methods in 011 , 012 , 013 , 014 and 015 . That is, the processor 30 can also be used to: obtain a preset time period and a preset time resolution; determine a plurality of time units according to the time period and time resolution, and the time units are arranged in sequence on the time axis; The arrival time of 50; determine the time unit corresponding to each photon according to the arrival time; and count the number of photons corresponding to each time unit to establish a time-of-flight histogram.

Please refer to FIG. 3 , in some implementation manners, the acquisition module 11 can also be used to implement the methods in 011 , 012 , 013 , 014 and 015 . That is, the acquisition module 11 can also be used to: acquire a preset time period and a preset time resolution; determine a plurality of time units according to the time period and time resolution, and the time units are arranged sequentially on the time axis; The arrival time of 50; determine the time unit corresponding to each photon according to the arrival time; and count the number of photons corresponding to each time unit to establish a time-of-flight histogram.

Wherein, the longer the preset time period is, the greater the maximum value of the flight time determined according to the time-of-flight histogram is, and the greater the ranging range is; the shorter the preset time period is, the higher the ranging efficiency is. When the preset time period is the same, the larger the preset time resolution (the wider the width per unit time), the photon count can be clearly seen in the time-of-flight histogram with only a small number of photon counts The peak value of the value, thereby improving the ranging efficiency; the smaller the preset time resolution (the narrower the width per unit time), the more accurate the flight time can be determined through the time-of-flight histogram, and the more accurate the ranging result.

In some embodiments, when sensor 50 receives a photon, sensor 50 generates a response signal. The processor 30 records a response time stamp when receiving the response signal, and uses the response time stamp as the arrival time of the photon. After obtaining the arrival time of a photon, the time unit corresponding to the arrival time can be found in the time-of-flight histogram, and the photon count value corresponding to the time unit is increased by 1. For example, please refer to Figure 4, assuming that a certain arrival time is 0.2ns, then according to the 0.2ns is within the time period from 0ns to 0.5ns, that is, the time period of the first time unit, so the The photon count value corresponding to 1 time unit is increased by 1. After several times of photon counting statistics, count the corresponding number of photons in each time unit, that is, count the corresponding photon count value in each time unit, and use the photon count value as the height of the rectangular column of each time unit to establish the final flight time histogram.

Referring to FIG. 5 , in some implementations, the resolution of each time unit in the time-of-flight histogram is the same. In this way, the difficulty of accumulating photon count values in each time unit is the same, and any distance within the ranging range can be measured with the same ranging accuracy.

Referring to FIG. 9 , in some implementations, the time-of-flight histogram includes a region of interest and a region of non-interest, and the resolution of time units in the region of interest is smaller than the resolution of time units in the region of non-interest. Among them, the region of interest is the time interval determined according to the distance of interest (the measured subject is within the distance of interest), and the region of non-interest is the time interval outside the region of interest in the time-of-flight histogram, that is, according to the non-interest region The time interval determined by the distance of interest (the measured subject is outside the non-interest distance range). The smaller the resolution of the time unit, the more accurate the time-of-flight determined according to the time unit, so that ranging can be performed with higher detection accuracy at the distance of interest. For example, in the time-of-flight histogram shown in FIG. 9 , the time interval from 1 ns to 2 ns is the region of interest, the second and third time units are the time units of the region of interest, and the corresponding time resolution is 0.5 ns. Time intervals other than the time interval from 1 ns to 2 ns are non-interest regions, and the time resolution corresponding to the time unit of the non-interest region is 1 ns. Compared with the non-interest region, the resolution of the time unit in the region of interest is smaller, and there are more time units divided in the same time interval, and the flight time determined according to the time unit of the region of interest is more accurate. However, setting the time resolution corresponding to the time unit of the non-interest region to be larger can improve the efficiency of ranging.

Please refer to FIG. 10. In some embodiments, 02: determine the peak unit and multiple neighboring units from the time unit according to the time-of-flight histogram, including:

021: Obtain the photon count value corresponding to each time unit;

022: Determine the time unit corresponding to the maximum photon count value as the peak unit; and

023: Determine at least one time unit adjacent to the left of the peak unit and at least one time unit adjacent to the right of the peak unit in the time-of-flight histogram as neighborhood units.

Please refer to FIG. 2 , in some implementation manners, the processor 30 may also be used to implement the methods in 021 , 022 and 023 . That is, the processor 30 can also be used to: acquire the photon count value corresponding to each time unit; determine the time unit corresponding to the maximum photon count value as the peak unit; At least one time unit and at least one time unit adjacent to the right side of the peak unit are determined as neighboring units.

Please refer to FIG. 3 , in some embodiments, the retrieval module 12 can also be used to implement the methods in 021 , 022 and 023 . That is, the retrieval module 12 can also be used to: obtain the photon count value corresponding to each time unit; determine the time unit corresponding to the maximum photon count value as the peak unit; At least one time unit and at least one time unit adjacent to the right side of the peak unit are determined as neighboring units.

Please refer to FIG. 5 , the ordinate of the histogram of each time unit is the photon count value corresponding to the time unit. The ordinate of the highest-height bar along the vertical axis is the maximum photon count value, and the time unit corresponding to the bar is the peak unit. The neighborhood unit is a time unit adjacent to the peak unit, and the neighborhood unit includes at least one left neighbor unit located on the left side of the peak unit and at least one right neighbor unit located on the right side of the peak unit. The number of left neighbor units may be 1, 2, 3 or more, which will not be listed here. When the number of left neighbor units is 1, the left neighbor unit is the nearest time unit to the left of the peak unit; when the number of left neighbor units is n (n>1), the left neighbor unit is the self-peak unit The nearest time unit on the left is n time units distributed sequentially along the left side of the horizontal axis. The number of right neighbor units may be 1, 2, 3 or more, which will not be listed here. In one embodiment, the neighborhood unit includes 1 left neighborhood unit and 1 right neighborhood unit, for example, in the time-of-flight histogram shown in Figure 5, the 3rd time unit is a peak unit, the 2nd and 4th A time unit is a neighborhood unit. At this time, the number of time units included in the neighborhood unit is the least, and the amount of data processing is less when determining the flight time according to the parameter value of the peak unit and the parameter values of multiple neighbor units, thus having a higher ranging efficiency.

Referring to FIG. 11 , in some embodiments, the parameter value includes the resolution of the time unit, the photon count value corresponding to the time unit, and the serial number of the time unit in chronological order. 03: Determine the flight time according to the parameter value of the peak unit and the parameter values of multiple neighboring units, including:

031: Obtain the peak count value corresponding to the peak unit, the left count value corresponding to the left neighbor unit, and the right count value corresponding to the right neighbor unit;

032: Determine the correction value according to the peak count value, left count value, right count value and preset correction parameters; and

033: Determine the flight time according to the resolution of the peak unit, the serial number of the peak unit and the correction value.

Please refer to FIG. 2 , in some implementation manners, the processor 30 may also be used to implement the methods in 031 , 032 and 033 . That is, the processor 30 can also be used to: obtain the peak count value corresponding to the peak value unit, the left count value corresponding to the left neighbor unit, and the right count value corresponding to the right neighbor unit; value and preset calibration parameters to determine the calibration value; and determine the flight time according to the resolution of the peak unit, the serial number of the peak unit and the calibration value.

Please refer to FIG. 3 , in some implementation manners, the determining module 13 can also be used to implement the methods in 031 , 032 and 033 . That is, the determination module 13 can also be used to: obtain the peak count value corresponding to the peak value unit, the left count value corresponding to the left neighbor unit, and the right count value corresponding to the right neighbor unit; value and preset calibration parameters to determine the calibration value; and determine the flight time according to the resolution of the peak unit, the serial number of the peak unit and the calibration value.

Please refer to Fig. 6 and Fig. 7, in combination with the foregoing, the flight time can be determined according to the moment t emission when the photon is _emitted and the moment t _reception when the sensor 50 receives the photon reflected back from the object, that is, the flight time t=t _receive -t _emission . In some embodiments, the median instant t0 of the peak cell is _received as t to determine the time-of-flight t1 based on the peak cell. Since the median time t0 of the peak unit depends on the time resolution corresponding to the peak unit, the smaller the time resolution corresponding to the peak unit, the more accurate the median time t0 can be determined. Therefore, in the case that the resolution of the peak cell is limited and cannot be reduced, the peak cell has a fixed median instant t0, and the accuracy of the time-of-flight t1 determined from the median instant t0 is limited.

The ranging method of the embodiment of the present application can determine the correction value according to the peak count value, left count value, right count value and preset correction parameters, so as to determine the flight time according to the resolution of the peak unit, the serial number of the peak unit and the correction value, A precisely higher flight time is thereby determined. Wherein, when the peak unit is the nth time unit on the horizontal axis of the time-of-flight histogram, the serial number of the peak unit is n. The correction parameter is a preset constant value, which represents the influence of the peak count value, left count value, and right count value on the correction value. The correction value can represent the offset of the sensor 50 _receiving the photon reflected back from the object at time t relative to the peak unit. The value of the correction value can be a positive value, a negative value, or 0. When the correction value is positive, it means that the time t when the sensor 50 _receives the photons reflected back from the object is on the right side of the median time t0 of the peak unit, that is, t is _received >t0; when the correction value is negative, the time t _treceived is on the left side of time t0, that is, _treceived <t0; when the correction value is 0, the representation can take the median time t0 of the peak unit as _treceived , that is, _treceived =t0.

For example, if the serial number of the peak unit is 41 and the correction value is -0.45, then the corrected serial number is 40.55, and it can be determined that the time t when the sensor 50 receives the photon reflected from the object is _received on the left side of the median time t0 of the peak unit. In the time-of-flight histogram, the serial numbers n of all time units are positive integers, and there is actually no time unit with the serial number 40.55 in the time-of-flight histogram, but it does not affect the time t _received based on the time unit with the serial number 40.55 to determine flight duration. In one embodiment, the time resolution of each time unit is the same, and the median moment tn' of the time unit with the sequence number 40.55 can be determined in combination with the time resolution. For example, if the time resolution is 0.5ns, then tn'=0.5ns × 40.55 - (0.5 ns/2) = 20.025 ns, taking tn' as the instant t when the photon reflected back from the object is _received by the sensor 50 to determine the time-of-flight.

Please refer to FIG. 12 , in some embodiments, the calibration parameters include a first parameter, a second parameter and a third parameter. 032: Determine the correction value according to the peak count value, left count value, right count value and preset correction parameters, including:

0321: Obtain a weighted peak count value according to the peak count value and the first parameter;

0322: Obtain the weighted right count value according to the right count value and the second parameter;

0323: Obtain the weighted left count value according to the left count value and the third parameter;

0324: Obtain the first difference between the right count value and the left count value;

0325: Obtain the second difference between the weighted peak count value, the weighted right count value and the weighted left count value; and

0326: Obtain the ratio of the first difference to the second difference, and determine the ratio as the correction value.

Please refer to FIG. 2 , in some implementation manners, the processor 30 may also be used to implement the methods in 0321 , 0322 , 0323 , 0324 , 0325 and 0326 . That is, the processor 30 can also be used to: obtain the weighted peak count value according to the peak count value and the first parameter; obtain the weighted right count value according to the right count value and the second parameter; obtain the weighted left count value according to the left count value and the third parameter value; obtain the first difference between the right count value and the left count value; obtain the second difference between the weighted peak count value and the weighted right count value and the weighted left count value; and obtain the first difference and A ratio of the second difference is determined as the correction value.

Please refer to FIG. 3 , in some implementation manners, the determining module 13 may also be used to implement the methods in 0321 , 0322 , 0323 , 0324 , 0325 and 0326 . That is, the determination module 13 can also be used to: obtain the weighted peak count value according to the peak count value and the first parameter; obtain the weighted right count value according to the right count value and the second parameter; obtain the weighted left count value according to the left count value and the third parameter value; obtain the first difference between the right count value and the left count value; obtain the second difference between the weighted peak count value and the weighted right count value and the weighted left count value; and obtain the first difference and A ratio of the second difference is determined as the correction value.

For example, the first parameter is a, the second parameter is b, the third parameter is c, the peak count value is P1, the right count value is P2, and the left count value is P3. Thus, it can be calculated: weighted peak count value Pq1=a×P1, weighted right count value Pq2=b×P2, weighted left count value Pq3=c×P3, first difference F1=P2-P3, second difference The value F2=Pq1-Pq2-Pq3=a×P1-b×P2-c×P3. If the correction value is △n, then

Wherein, the first parameter a, the second parameter b, and the third parameter c are all preset constants, which can be obtained according to calibration before leaving the factory.

Please refer to FIG. 13. In some embodiments, 033: determine the flight time according to the resolution of the peak unit, the serial number of the peak unit and the correction value, including:

0331: Determine the correction serial number of the peak unit according to the serial number and correction value of the peak unit, and determine the flight time according to the correction serial number and the resolution of the peak unit.

Please refer to FIG. 2 , in some implementation manners, the processor 30 may also be used to implement the method in 0331 . That is, the processor 30 can also be used to: determine the correction serial number of the peak unit according to the serial number of the peak unit and the correction value, and determine the flight time according to the correction serial number and the resolution of the peak unit.

Please refer to FIG. 3 , in some implementation manners, the determination module 13 may also be used to implement the method in 0331 . That is, the determination module 13 can also be used to: determine the corrected serial number of the peak unit according to the serial number of the peak unit and the correction value, and determine the flight time according to the corrected serial number and the resolution of the peak unit.

Specifically, assuming that the sequence number of the peak unit is n, and the correction value is Δn, then the correction sequence number n'=n+Δn. In combination with the foregoing, the value of Δn can be positive, negative, or 0.

Please refer to Fig. 6, in one embodiment, the actual distance between the sensor 50 and the object is 3m, in the time-of-flight histogram obtained after repeated statistics: the serial number n=41 of the peak unit, the correction value Δn=- 0.45, the time resolution of the peak unit K=0.5ns. From this, it can be calculated that the correction number n'=n+Δn=41+(-0.45)=40.55. Let the time-of-flight be t, time-of-flight t= _{treceive -ttransmission} , wherein ttransmission is the moment when photons are _emitted , and treception is the moment when the sensor 50 _receives photons reflected back from the object. In the time-of-flight histogram of this embodiment, the counting of photon counts starts from the moment when photons are _emitted , so ttransmission=Ons, and time-of-flight t= _treception . And t _reception can be determined according to the following formula: t _reception =n'×K-(K/2). Among them, n'×K represents the moment corresponding to the right endpoint coordinates of the corrected peak unit on the time axis, and K/2 is half of the time resolution, that is, n'×K-(K/2) represents the n'th time The median moment of the cell. Substituting n'=40.55, K=0.5ns into t _receiving =n'×K-(K/2), the flight time can be calculated t=t _receiving =n'×K-(K/2)=40.55×0.5ns -(0.5ns/2)=20.025ns. In this way, combined with 04: Calculate the distance between the sensor 50 and the object according to the time of flight and the speed of light, and substitute t=20.025ns=20.025×10 ^-9 s, c=3×10 ⁸ m/s into

It can be calculated that the distance d=(20.025×10 ^-9 s×3×10 ⁸ m/s)/2=3.00375m.

As a comparison, the flight time t1=n×K−(K/2)=41×0.5ns−(0.5ns/2)=20.25ns determined only according to the parameter value of the peak value unit. The distance d1=(20.25×10 ⁻⁹ s×3×10 ⁸ m/s)/2=3.0375m acquired according to the flight time t1. It can be seen that the d calculated according to the flight time t is closer to the actual distance between the sensor 50 and the object than the d1 calculated according to the flight time t1, so the flight time is determined according to the resolution of the peak unit, the serial number of the peak unit and the correction value, A more precise flight time can be determined.

Further, in this embodiment (the embodiment illustrated in FIG. 6 ), when the time resolution K of the peak unit has been determined to be 0.5 ns, the distance resolution of the peak unit H=0.5 ns×3×10 ⁸ m/s = 0.075m, if the flight time t1 is determined only according to the parameter value of the peak unit, then the actual distance between the sensor 50 and the object is any value within the range of [3.000m, 3.075m], determined according to the parameter value of the peak unit The flight time t1 is both 20.25ns, the measurement distance d1 determined according to the flight time t is 3.0375m, and the maximum error is 0.0375m. According to the resolution of the peak unit, the serial number of the peak unit, and the correction value, the time-of-flight t determined is related to the correction value Δn, and the correction value is related to the parameter value of the peak unit, the parameter value of the left neighbor unit, and the value of the right field unit. The parameter values are related, and can represent the degree of offset from the peak unit to the left or right neighbor unit at the time t when the sensor 50 _receives the photon reflected back from the object. In this embodiment, when Δn<0, the value range of flight time t is [20.00ns, 20.25ns), and the range of distance d that can be determined according to the value of flight time t is [3.0000m, 3.0375m ), the maximum error is less than 0.0375m; when △n>0, the value range of flight time t is (20.25ns, 20.50ns], and the range of distance d that can be determined according to the value of flight time t is (3.0375m, 3.0750m], the maximum error is less than 0.0375m. That is, when Δn is not 0, the accuracy of flight time t is improved compared with flight time t1, and the measurement distance d determined by flight time t is compared with that determined by flight time t1 The accuracy of measuring the distance d1 is improved.

Please refer to FIG. 14. In some implementations, 033: Determine the flight time according to the resolution of the peak unit, the serial number of the peak unit and the correction value, including:

0332: Determine the peak time according to the serial number and resolution of the peak unit, determine the correction time according to the correction value and resolution, and determine the flight time according to the peak time and correction time.

Please refer to FIG. 2 , in some implementation manners, the processor 30 may also be used to implement the method in 0332 . That is, the processor 30 can also be used to: determine the peak time according to the serial number and resolution of the peak unit, determine the correction time according to the correction value and resolution, and determine the flight time according to the peak time and correction time.

Please refer to FIG. 3 , in some implementation manners, the determination module 13 may also be used to implement the method in 0332 . That is, the determination module 13 can also be used to: determine the peak time according to the serial number and resolution of the peak unit, determine the correction time according to the correction value and resolution, and determine the flight time according to the peak time and correction time.

Please refer to Fig. 6, specifically, set the serial number of the peak unit as n, the time resolution of each time unit as K, and the correction value as Δn. If the median time t0 of the peak unit is used as the peak time tn corresponding to the peak unit, then the peak time tn=n×K-(K/2) can be calculated. In some embodiments, any time tr in the peak unit can be used as the peak time tn corresponding to the peak unit, then the peak time tn=n×K-(K×u) can be calculated, where u is the self-time The ratio of the time period from tr to the right end point of the peak unit and the time resolution K, for example, when the time tr is the median time of the peak unit, u=1/2. Correction time Δt=Δn×K, flight time t=tn+Δt. In some implementations, when the time-of-flight histogram is established, the corresponding relationship between the sequence number of each time unit and the time corresponding to the time unit has been determined, and the corresponding relationship is stored in the memory 20 . When a certain time unit is determined as the peak unit, the peak time tn can be determined according to the serial number of the peak unit and the corresponding relationship, thereby simplifying the calculation and improving the ranging efficiency.

Please refer to FIG. 15. In some implementations, 033: Determine the flight time according to the resolution of the peak unit, the serial number of the peak unit and the correction value, including:

0333: Determine the correction serial number of the peak unit according to the serial number and correction value of the peak unit, and use the time corresponding to the correction serial number on the time-of-flight histogram as the flight time.

Please refer to FIG. 2 , in some implementation manners, the processor 30 may also be used to implement the method in 0333 . That is, the processor 30 may also be configured to: determine the correction number of the peak unit according to the number of the peak unit and the correction value, and use the moment corresponding to the correction number on the time-of-flight histogram as the flight time.

Please refer to FIG. 3 , in some implementation manners, the determining module 13 may also be used to implement the method in 0333 . That is, the determining module 13 may also be configured to: determine the corrected serial number of the peak unit according to the serial number of the peak unit and the correction value, and use the moment corresponding to the corrected serial number on the time-of-flight histogram as the flight time.

Please refer to FIG. 6, specifically, set the serial number of the peak unit as n, and the correction value as Δn. Then the correction number n'=n+Δn can be calculated. In combination with the foregoing description, the counting of photon counts starts from the moment when photons are emitted in the time-of-flight histogram, so t _emission =Ons, time-of-flight t=t _reception . In some implementations, the peak time tn' of the corrected peak unit (ie, the time unit numbered n') is _received as t. In the time-of-flight histogram, the peak time tn' of the time unit with the serial number n' is represented as the time corresponding to the time unit with the serial number n' on the time axis of the time-of-flight histogram. When the time-of-flight histogram is established, the corresponding relationship between the serial number of each time unit and the time corresponding to the time unit on the time axis has been determined, and the corresponding relationship is stored in the memory 20 . After the serial number n' of the corrected peak unit is determined, the peak time tn' can be determined according to the serial number n' and the corresponding relationship, and the flight time t=tn', thereby simplifying the calculation and improving the ranging efficiency.

Referring to FIG. 16 , one or more non-transitory computer-readable storage media 300 containing a computer program 301 according to an embodiment of the present application, when the computer program 301 is executed by one or more processors 30, the processors 30 can Execute the ranging method in any of the above embodiments, for example, implement steps 01, 02, 03, 04, 011, 012, 013, 014, 015, 021, 022, 023, 031, 032, 033, 0321, 0322, 0323, One or more steps in 0324, 0325, 0326, 0331, 0332 and 0333.

For example, when the computer program 301 is executed by one or more processors 30, the processors 30 are made to perform the following steps:

01: Obtain the time-of-flight histogram, which represents the number of photons received by the sensor in each time unit;

02: Determine the peak unit and multiple neighboring units from the time unit according to the time-of-flight histogram;

03: Determine the flight time according to the parameter value of the peak unit and the parameter values of multiple neighboring units; and

04: Calculate the distance between the sensor and the object based on the flight time and the speed of light.

For another example, when the computer program 301 is executed by one or more processors 30, the processors 30 are made to perform the following steps:

011: Obtain a preset time period and a preset time resolution;

012: Determine multiple time units according to the time period and time resolution, and the time units are arranged in sequence on the time axis;

013: Obtain the arrival time of each photon arriving at the sensor;

014: Determine the time unit corresponding to each photon according to the arrival time;

015: Count the number of photons corresponding to each time unit to establish a time-of-flight histogram;

021: Obtain the photon count value corresponding to each time unit;

022: Determine the time unit corresponding to the maximum photon count value as the peak unit;

023: Determine at least one time unit adjacent to the left side of the peak unit and at least one time unit adjacent to the right side of the peak unit in the time-of-flight histogram as neighborhood units;

031: Obtain the peak count value corresponding to the peak unit, the left count value corresponding to the left neighbor unit, and the right count value corresponding to the right neighbor unit;

032: Determine the correction value according to the peak count value, left count value, right count value and preset correction parameters; and

033: Determine the flight time according to the resolution of the peak unit, the serial number of the peak unit and the correction value;

04: Calculate the distance between the sensor 50 and the object according to the flight time and the speed of light.

In the description of this specification, reference to the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific examples" or "some examples" etc. The specific features, structures, materials or features described in the manner or example are included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the described specific features, structures, materials or characteristics may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and combine different embodiments or examples and features of different embodiments or examples described in this specification without conflicting with each other.

Any process or method descriptions in flowcharts or otherwise described herein may be understood to represent modules, segments or portions of code comprising one or more executable instructions for implementing specific logical functions or steps of the process , and the scope of preferred embodiments of the present application includes additional implementations in which functions may be performed out of the order shown or discussed, including in substantially simultaneous fashion or in reverse order depending on the functions involved, which shall It is understood by those skilled in the art neighborhood to which the embodiments of the present application belong.

Although the implementation of the present application has been shown and described above, it can be understood that the above-mentioned implementation is exemplary and should not be construed as a limitation of the application, and those skilled in the art within the scope of the application can Variations, modifications, substitutions and variations of the above described embodiments.

Claims (20)

1. A ranging method, including:

   Obtaining a time-of-flight histogram, the time-of-flight histogram representing the number of photons received by the sensor in each time unit;

   determining a peak unit and a plurality of neighboring units from the time unit according to the time-of-flight histogram;

   determining a time-of-flight based on the parameter value of the peak cell and the parameter values of a plurality of the neighboring cells; and

   The distance between the sensor and the object is calculated according to the time-of-flight and the speed of light.
2. The ranging method according to claim 1, wherein said obtaining the time-of-flight histogram comprises:

   Obtain a preset time period and a preset time resolution;

   A plurality of time units are determined according to the time period and the time resolution, and the time units are arranged sequentially on the time axis;

   Obtain the arrival time of each photon arriving at the sensor;

   determining a time unit corresponding to each of the photons according to the arrival time; and

   The number of photons corresponding to each time unit is counted to establish the time-of-flight histogram.
3. The ranging method according to claim 1, wherein the resolution of each time unit in the time-of-flight histogram is the same.
4. The ranging method according to claim 1, wherein the time-of-flight histogram includes an area of interest and an area of non-interest, and the resolution of the time unit of the area of interest is smaller than the time unit of the area of non-interest resolution.
5. The ranging method according to claim 1, wherein said determining a peak unit and a plurality of neighboring units from said time unit according to said time-of-flight histogram comprises:

   Acquiring the photon count value corresponding to each time unit;

   determining the time unit corresponding to the maximum photon count value as the peak unit; and

   Determining at least one time unit adjacent to the left of the peak unit and at least one time unit adjacent to the right of the peak unit in the time-of-flight histogram as the neighborhood units.
6. The ranging method according to claim 1, wherein the neighborhood unit includes a left neighborhood unit located on the left side of the peak unit and a right neighborhood unit located on the right side of the peak unit, and the parameter value includes The resolution of the time unit, the photon count value corresponding to the time unit, and the sequence number of the time unit appearing in time order.
7. The ranging method according to claim 6, wherein said determining time-of-flight according to said peak unit and a plurality of said neighborhood units comprises:

   Obtain the peak count value corresponding to the peak value unit, the left count value corresponding to the left neighbor unit, and the right count value corresponding to the right neighbor unit;

   determining a correction value according to the peak count value, the left count value, the right count value and a preset correction parameter; and

   The time of flight is determined according to the resolution of the peak unit, the serial number of the peak unit and the correction value.
8. The distance measuring method according to claim 7, wherein the correction parameters include a first parameter, a second parameter and a third parameter, and the said peak count value, the left count value, and the right count value and preset calibration parameters to determine the calibration value, including:

   Obtaining a weighted peak count value according to the peak count value and the first parameter;

   Obtaining a weighted right count value according to the right count value and the second parameter;

   Obtaining a weighted left count value according to the left count value and the third parameter;

   obtaining a first difference between the right count value and the left count value;

   Obtaining a second difference between the weighted peak count value and the weighted right count value and the weighted left count value in turn; and

   A ratio of the first difference to the second difference is obtained, and the ratio is determined as the correction value.
9. The ranging method according to claim 7, wherein said determining the flight time according to the resolution of the peak unit, the serial number of the peak unit and the correction value comprises:

   determining the corrected serial number of the peak unit according to the serial number of the peak unit and the correction value, and determining the time-of-flight according to the corrected serial number and the resolution of the peak unit; or

   determining the peak moment according to the serial number of the peak unit and the resolution, determining the correction time according to the correction value and the resolution, and determining the flight time according to the peak moment and the correction time; or

   The corrected serial number of the peak unit is determined according to the serial number of the peak unit and the correction value, and the time corresponding to the corrected serial number on the time-of-flight histogram is taken as the time of flight.
10. A distance measuring device, including:

    An acquisition module, the acquisition module is used to acquire a time-of-flight histogram, the time-of-flight histogram characterizes the quantity of photons received by the sensor in each time unit;

    A retrieval module, configured to determine a peak unit and a plurality of neighboring units from the time unit according to the time-of-flight histogram;

    A determining module, the determining module is used to determine the flight time according to the parameter value of the peak unit and the parameter values of a plurality of the neighboring units; and

    A calculation module, the calculation module is used to calculate the distance between the sensor and the object according to the time-of-flight and the speed of light.
11. A terminal, wherein the terminal includes:

    one or more processors, memory; and

    One or more programs, wherein the one or more programs are stored in the memory and executed by the one or more processors, the programs include a method for performing the ranging method according to claim 1 instructions.
12. The terminal according to claim 11, wherein the processor is further configured to:

    Obtain a preset time period and a preset time resolution;

    A plurality of time units are determined according to the time period and the time resolution, and the time units are arranged sequentially on the time axis;

    Obtain the arrival time of each photon arriving at the sensor;

    determining a time unit corresponding to each of the photons according to the arrival time; and

    The number of photons corresponding to each time unit is counted to establish the time-of-flight histogram.
13. The terminal according to claim 12, wherein the resolution of each of the time units in the time-of-flight histogram is the same.
14. The terminal according to claim 12, wherein the time-of-flight histogram includes a region of interest and a region of non-interest, and the resolution of the time unit of the region of interest is smaller than the resolution of the time unit of the region of non-interest Rate.
15. The terminal according to claim 12, wherein the processor is further configured to:

    Acquiring the photon count value corresponding to each time unit;

    determining the time unit corresponding to the maximum photon count value as the peak unit; and

    Determining at least one time unit adjacent to the left of the peak unit and at least one time unit adjacent to the right of the peak unit in the time-of-flight histogram as the neighborhood units.
16. The terminal according to claim 12, wherein the neighborhood unit includes a left neighborhood unit located on the left side of the peak unit and a right neighborhood unit located on the right side of the peak unit, and the parameter value includes the The resolution of the time unit, the photon count value corresponding to the time unit, and the serial number of the time unit appearing in time order.
17. The terminal according to claim 16, wherein the processor is further configured to:

    Obtain the peak count value corresponding to the peak value unit, the left count value corresponding to the left neighbor unit, and the right count value corresponding to the right neighbor unit;

    determining a correction value according to the peak count value, the left count value, the right count value and a preset correction parameter; and

    The time of flight is determined according to the resolution of the peak unit, the serial number of the peak unit and the correction value.
18. The terminal according to claim 17, wherein the processor is further configured to:

    Obtaining a weighted peak count value according to the peak count value and the first parameter;

    Obtaining a weighted right count value according to the right count value and the second parameter;

    Obtaining a weighted left count value according to the left count value and the third parameter;

    obtaining a first difference between the right count value and the left count value;

    Obtaining a second difference between the weighted peak count value and the weighted right count value and the weighted left count value in turn; and

    A ratio of the first difference to the second difference is obtained, and the ratio is determined as the correction value.
19. The terminal according to claim 17, wherein the processor is further configured to:

    determining the corrected serial number of the peak unit according to the serial number of the peak unit and the correction value, and determining the time-of-flight according to the corrected serial number and the resolution of the peak unit; or

    determining the peak moment according to the serial number of the peak unit and the resolution, determining the correction time according to the correction value and the resolution, and determining the flight time according to the peak moment and the correction time; or

    The corrected serial number of the peak unit is determined according to the serial number of the peak unit and the correction value, and the time corresponding to the corrected serial number on the time-of-flight histogram is taken as the time of flight.
20. A non-transitory computer-readable storage medium containing a computer program that, when executed by one or more processors, causes the processors to implement the measurement method described in any one of claims 1 to 9 distance method.

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