CN113484870A - Ranging method and apparatus, terminal, and non-volatile computer-readable storage medium - Google Patents
Ranging method and apparatus, terminal, and non-volatile computer-readable storage medium Download PDFInfo
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- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
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- G01S17/46—Indirect determination of position data
- G01S17/48—Active triangulation systems, i.e. using the transmission and reflection of electromagnetic waves other than radio waves
Abstract
The application discloses a distance measuring method, a distance measuring device, a terminal and a non-volatile computer readable storage medium. The distance measurement method comprises the following steps: acquiring a flight time histogram; determining a peak unit and a plurality of neighborhood units from the time units according to the flight time histogram; determining flight time according to the parameter values of the peak unit and the parameter values of the plurality of neighborhood units; and calculating the distance between the sensor and the object according to the flight time and the light speed. The distance measuring method, the distance measuring device, the terminal and the nonvolatile computer readable storage medium can determine the flight time according to the parameter value of the peak unit and the parameter values of the plurality of neighborhood units so as to obtain more accurate flight time, and therefore the distance measuring precision can be improved.
Description
Technology neighborhood
The present disclosure relates to the field of ranging technologies, and in particular, to a ranging method, a ranging apparatus, a terminal, and a non-volatile computer-readable storage medium.
Background
Direct Time of flight (dtofs) is a ranging technique that calculates the distance between an object and a sensor by measuring the Time difference between the transmitted signal and the signal reflected back by the object. The time at which the sensor receives a signal reflected back by an object is typically determined by means of a histogram. Due to the limitation of hardware circuit design, the time resolution of the histogram, i.e., the unit time counted by each histogram column corresponding to the abscissa has the minimum unit, which limits the size of the minimum counted time unit, and it is difficult to further accurately determine the time when the sensor receives the signal reflected back by the object, resulting in a limited resolution of the final measured output distance.
Disclosure of Invention
The embodiment of the application provides a distance measuring method, a distance measuring device, a terminal and a non-volatile computer readable storage medium.
The distance measurement method in the embodiment of the application comprises the following steps: acquiring a flight time histogram; determining a peak unit and a plurality of neighborhood units from the time units according to the flight time histogram; determining flight time according to the parameter values of the peak unit and the parameter values of the plurality of neighborhood units; and calculating the distance between the sensor and the object according to the flight time and the light speed.
The distance measuring device comprises an acquisition module, a retrieval module, a determination module and a calculation module. The acquisition module may be configured to acquire a time-of-flight histogram. The retrieval module may be configured to determine a peak cell and a plurality of neighborhood cells from the time cell based on the time-of-flight histogram. The determination module may be configured to determine a time of flight based on the parameter value for the peak cell and the parameter values for the plurality of neighbor cells. The calculation module can be used for calculating the distance between the sensor and the object according to the flight time and the light speed.
The terminal of embodiments of the present application 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 including instructions for performing the ranging method of embodiments of the present application. The distance measurement method comprises the following steps: acquiring a flight time histogram; determining a peak unit and a plurality of neighborhood units from the time units according to the flight time histogram; determining flight time according to the parameter values of the peak unit and the parameter values of the plurality of neighborhood units; and calculating the distance between the sensor and the object according to the flight time and the light speed.
A non-transitory computer-readable storage medium containing a computer program of embodiments of the present application, which, when executed by one or more processors, causes the processors to implement a ranging method of embodiments of the present application. The distance measurement method comprises the following steps: acquiring a flight time histogram; determining a peak unit and a plurality of neighborhood units from the time units according to the flight time histogram; determining flight time according to the parameter values of the peak unit and the parameter values of the plurality of neighborhood units; and calculating the distance between the sensor and the object according to the flight time and the light speed.
The distance measuring method, the distance measuring device, the terminal and the nonvolatile computer readable storage medium can determine the flight time according to the parameter value of the peak unit and the parameter values of the plurality of neighborhood units so as to obtain more accurate flight time, and therefore the distance measuring precision can be improved.
Additional aspects and advantages of embodiments of the present application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present application.
Drawings
The above and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is a schematic flow chart of a ranging method according to some embodiments of the present disclosure;
FIG. 2 is a schematic block diagram of a terminal according to some embodiments of the present application;
FIG. 3 is a schematic diagram of a range finder apparatus according to certain embodiments of the present application;
FIG. 4 is a schematic illustration of a time-of-flight histogram of certain embodiments of the present application;
FIG. 5 is a schematic illustration of a time-of-flight histogram of certain embodiments of the present application;
FIG. 6 is a schematic illustration of a time-of-flight histogram of certain embodiments of the present application;
FIG. 7 is a schematic illustration of a time-of-flight histogram of certain embodiments of the present application;
FIG. 8 is a schematic flow chart diagram of a ranging method according to some embodiments of the present application;
FIG. 9 is a schematic illustration of a time-of-flight histogram of certain embodiments of the present application;
FIG. 10 is a schematic flow chart diagram of a ranging method according to some embodiments of the present application;
FIG. 11 is a schematic flow chart diagram illustrating a ranging method according to some embodiments of the present application;
FIG. 12 is a schematic flow chart diagram of a ranging method according to some embodiments of the present application;
FIG. 13 is a schematic flow chart diagram of a ranging method according to some embodiments of the present application;
FIG. 14 is a schematic flow chart diagram illustrating a ranging method according to some embodiments of the present application;
FIG. 15 is a schematic flow chart diagram of a ranging method according to some embodiments of the present application;
FIG. 16 is a schematic diagram of a connection between a computer-readable storage medium and a processor according to some embodiments of the present application.
Detailed Description
Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below by referring to the drawings are exemplary only for the purpose of explaining the embodiments of the present application, and are not to be construed as limiting the embodiments of the present application.
The embodiment of the application provides a distance measuring method. Referring to fig. 1, a ranging method according to an embodiment of the present disclosure includes:
01: acquiring a flight time histogram, wherein the flight time histogram represents the number of photons received by the sensor in each time unit;
02: determining a peak unit and a plurality of neighborhood units from the time units according to the flight time histogram;
03: determining flight time according to the parameter values of the peak unit and the parameter values of the plurality of neighborhood units; and
04: and calculating the distance between the sensor and the object according to the flight time and the light speed.
Referring to fig. 2, the present embodiment also provides a terminal 100, and the ranging method of the present embodiment can be applied to the terminal 100. The terminal 100 includes one or more processors 30, memory 20, and one or more programs. Where one or more programs are stored in memory 20 and executed by one or more processors 30, the programs including instructions for performing the ranging methods of embodiments of the present application. That is, when the processor 30 executes the program, the processor 30 may implement the methods in steps 01, 02, 03, and 04. That is, the processor 30 may be configured to: acquiring a flight time histogram; determining a peak unit and a plurality of neighborhood units from the time units according to the flight time histogram; determining flight time according to the parameter values of the peak unit and the parameter values of the plurality of neighborhood units; and calculating the distance between the sensor and the object according to the flight time and the light speed.
In some embodiments, terminal 100 further includes a transmitting end 40 and a sensor 50. The emission end 40 is configured to emit a light beam, which includes a plurality of photons. The sensor 50 is used to receive photons reflected back from the object. Thus, the time of flight can be determined from the time the light beam is emitted and the time the sensor 50 receives photons reflected back from the object.
Referring to fig. 2 and 3, the present invention further provides a ranging apparatus 10, and the ranging apparatus 10 can be applied to a terminal 100. The ranging apparatus 10 includes an acquisition module 11, a retrieval module 12, a determination module 13, and a calculation module 14. The obtaining module 11 may be used to implement the method in 01, the retrieving module 12 may be used to implement the method in 02, the determining module 13 may be used to implement the method in 03, and the calculating module 14 may be used to implement the method in 04. That is, the acquisition module 11 may be used to acquire a time-of-flight histogram. The retrieval module 12 may be configured to determine a peak cell and a plurality of neighborhood cells from the time cell based on the time-of-flight histogram. The determination module 13 may be configured to determine the time of flight based on the parameter value of the peak cell and the parameter values of the plurality of neighbor cells. The calculation module 14 may be used to calculate the distance between the sensor 50 and the object according to the time of flight and the speed of light.
Please refer to fig. 1 to 3. Wherein, the time of flight is the time that the photon passes from the exit, the reflection by the object to the reception by the sensor 50, and the distance between the sensor 50 and the object, i.e. the distance between the sensor 50 and the object, can be calculated by the time of flight ranging method according to the time of flight
Wherein d is between the sensor 50 and the objectC 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 photon emitting end 40 and the sensor 50 is as close as possible to ensure the round-trip distance of the photons, that is, the distance between the photons emitted from the emitting end 40 to the object and the distance between the photons reflected from the object and the sensor 50 are as close as possible, thereby ensuring the accuracy of the ranging result.
Referring to fig. 4 and 5, the time-of-flight histogram characterizes the number of photons received by sensor 50 in each time cell. Specifically, the time-of-flight histogram characterizes the number of photons received by sensor 50 (shown in FIG. 2) in each time unit after m statistics. For example, the number of photons is counted once every time a preset measurement period passes, and in one counting, if the sensor 50 receives a photon, the photon count value of the time unit in which the time (which can be determined by the timestamp) when the sensor 50 receives the photon is increased by 1; if no photons are received by sensor 50 during a single statistic, the photon count value is not incremented. In this manner, the number of photons received by sensor 50 in each time cell can be characterized based on the photon count value corresponding to each time cell.
In the time-of-flight histogram, the starting point of the time axis is the starting point of one measurement cycle and is also the time at which a photon is emitted. According to the time-of-flight ranging principle, the time-of-flight can be determined according to the time at which the photon is emitted and the time at which the photon is received by the sensor 50. However, the photons received by the sensor 50 need not be photons reflected back from an object, but may also be noise signals, such as photons present in the environment (ambient light). Therefore, counting the number of primary photons alone cannot determine whether the photons received by the sensor 50 are photons reflected back from an object. 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 a plurality of measurement periods, and the photon count value corresponding to each time unit can reflect the energy value, i.e., the light intensity, of the photons received by the time unit at the same time. Referring to fig. 2, the light beam emitted from the emitting end 40 has a higher 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), and in the time-of-flight histogram, the larger the photon count value corresponding to a time unit is, the higher the light intensity corresponding to the time unit is, and the higher the probability that the photon counted by the time unit is the photon in the light beam reflected back from the object is.
Referring to fig. 4 and 5, in particular, in one embodiment, the time-of-flight histogram illustrated in fig. 4 is a time-of-flight histogram obtained through 10 statistics, and the time-of-flight histogram illustrated in fig. 5 is a time-of-flight histogram obtained through 100 statistics. The abscissa of the time-of-flight histogram represents time and the ordinate represents the number of photons received by sensor 50. Time units are time scales on the abscissa time axis, each time unit representing 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 1 st time unit on the time axis are 0ns and 0.5ns, respectively, then the 1 st time unit represents a period of time between the 0ns th to 0.5ns on the time axis. The two endpoints of the 2 nd time unit on the time axis are 0.5ns and 1.0ns, respectively, then the 2 nd time unit represents a period of time between 0.5ns to 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, and the height of each time unit, i.e., the ordinate corresponding to the time unit, represents the number of photons received by the sensor 50 in the time unit after m times of statistics. For example, as shown in fig. 4, after 10 times of statistics, the ordinate corresponding to the 3 rd time unit is 5, which represents that 5 photons are received by the sensor 50 within the time period from 1.0ns to 1.5ns after 10 times of statistics, and the photon count value corresponding to the 3 rd time unit is 5 at this time. For example, as shown in fig. 5, after 100 times of statistics, the ordinate corresponding to the 5 th time unit is 52, which represents that 52 photons are received by the sensor 50 in the time period from 1.0ns to 1.5ns after 100 times of statistics, and the photon count value corresponding to the 3 rd time unit is 52 at this time.
In conjunction with the foregoing, the greater the photon count value for a time cell, the higher the light intensity for that time cell, the higher the probability that sensor 50 will receive a photon reflected back from an object in that time cell, and the greater the probability that the distance calculated based on the time of flight determined for that time cell will be the actual measured distance. Therefore, to obtain accurate time-of-flight, it is necessary to determine a peak unit from a plurality of time units to determine the time-of-flight based on the peak unit. Wherein, the peak value unit is the time unit with the largest photon counting value, namely the time unit with the highest energy (light intensity).
However, the peak unit characterizes a time period during which the sensor 50 receives photons reflected from the object, and it is not possible to determine which time instant within the time period is the time instant at which the sensor 50 receives photons reflected from the object. In some embodiments, the median time of the time period characterized by the peak cells may be determined as the time at which the sensor 50 receives photons reflected back from the object. For example, in the histogram illustrated in fig. 5, the peak cell is the 3 rd time cell, which represents a period of time between 1.0ns and 1.5ns on the time axis, and this time of 1.25ns is determined as the time when the sensor 50 receives the photons reflected from the object, so as to calculate the time of flight. Based on the above principle, when determining the time when the sensor 50 receives the photon according to the peak unit, the smaller the range of the time period represented by the peak unit, i.e., the thinner the histogram corresponding to the peak unit (the narrower the width of the horizontal axis), the more accurate the time when the sensor 50 receives the photon reflected from the object according to the peak unit. In theory, in the limiting case, when one peak cell represents a certain time instant, that is, the time instant at which the sensor 50 receives a photon reflected back from an object. Due to the limitations of the hardware circuit design, there is a minimum in the time period characterized by the time cell, i.e. the time resolution of the time cell, resulting in that the accuracy of the time instants at which the sensor 50 receives photons reflected back from the object, which can be determined from the peak cells, is limited by the minimum time resolution of the time cell. When the time resolution of a time unit reaches a minimum, the accuracy of the time determined according to the time unit reaches a maximum, and cannot be further improved. In addition, if the time resolution of the time cell is too small, the required photon count statistics may be greatly increased to ensure accurate ranging, possibly resulting in reduced ranging efficiency.
The distance measurement method can determine a peak value unit and a plurality of neighborhood units from a time unit according to a flight time histogram, and determine the flight time according to the parameter values of the peak value unit and the parameter values of the neighborhood units. The neighborhood unit is at least one time unit adjacent to the peak unit, and the parameter values may include resolution of the time unit, photon count values corresponding to the time unit, sequence numbers of the time units appearing in time sequence, and the like. For example, referring to fig. 5, the peak cell is the 3 rd time cell, and the 2 nd time cell and the 4 th time cell can be used as the neighbor cells corresponding to the peak cell. The peak cell is the time cell with the highest energy (intensity), and the neighboring cell corresponding to the peak cell is often the time cell with higher energy (intensity). Based on determining that the time at which the sensor 50 receives a photon reflected back from an object is within a peak cell, the values of the parameters of the neighborhood cells can be combined to further determine whether the time at which the sensor 50 receives a photon reflected back from an object is closer to the neighborhood cell on the left or closer to the neighborhood cell on the right.
For example, referring to fig. 6 and 7, in the time-of-flight histograms shown in fig. 6 and 7, the 41 th time cell is the peak cell, the neighborhood cell corresponding to the peak cell includes the 40 th time cell on the left side of the 41 th time cell and the 42 th time cell on the right side of the 41 th time cell, and t0 is the time corresponding to the midpoint of the peak cell along the horizontal axis. Let the time resolution of a time unit be 0.5ns, and in combination with the speed of light, a photon can move 0.075m in 0.5ns, which corresponds to a distance resolution of 0.075m with a time resolution of 0.5 ns. Thus, 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 3.075 m. Since the peak unit represents a period of time on the time axis, the middle point of the period of time, i.e. the median time of the peak unit, is usually taken to determine the time of flight. The distance measurement result d1 calculated from the time of flight t1 determined from the median time of the peak unit is 3.0375 m. If the time of flight t1 is determined based on only the peak cell, when the true distance takes a value in the range of [3.000m, 3.075m ], the distance measurement result d1 calculated from the time of flight t1 and the speed of light is 3.0375m regardless of whether the true distance takes any value in the range of [3.000m, 3.075m ], and it is difficult to further calculate a more accurate distance in the case where the time resolution of the time cell cannot be reduced.
The distance measurement method can determine the flight time according to the parameter value of the peak unit and the parameter values of the plurality of neighborhood units so as to determine the more accurate flight time, and therefore the distance measurement precision is improved.
Specifically, referring to fig. 6, in the time-of-flight histogram shown in fig. 6, if the photon count value corresponding to the 40 th time unit is greater than the photon count value corresponding to the 42 th time unit, the actual time-of-flight is most likely to be on the left of the median time of the peak unit, and after the time-of-flight t2 is determined according to the parameter values of the peak unit and the parameter values of the neighboring units, the distance d2 calculated according to the time-of-flight t2 and the speed of light is within the range [3.0000m, 3.0375m), that is, when the true distance is within the range [3.0000m, 3.0375m), the output d2 is used as the ranging result. That is, the distance resolution corresponding to the distance measurement result d2 is 0.0375m at most, which is smaller than the distance resolution corresponding to the distance measurement result d1 of 0.075 m; the corresponding temporal resolution is 0.25ns maximum and less than the peak cell temporal resolution of 0.5 ns.
Similarly, referring to fig. 7, in the time-of-flight histogram shown in fig. 7, the photon count value corresponding to the 40 th time unit is smaller than the photon count value corresponding to the 42 th time unit, then the maximum peak probability of the peak unit is on the right side of the midpoint of the peak unit along the horizontal axis, after the time-of-flight t3 is determined according to the parameter value of the peak unit and the parameter values of the plurality of neighborhood units, the distance d3 calculated according to the time-of-flight t3 and the speed of light is within the range (3.0375m, 3.0750 m), i.e., when the true distance is within the range (3.0375m, 3.0750 m), the output d3 is taken as the ranging result, i.e., the distance resolution corresponding to the ranging result d3 is 0.0375m at the maximum, and is smaller than the distance resolution 0.075m corresponding to the ranging result d1, the corresponding time resolution is 0.25ns at the maximum, and is smaller than the time resolution of the peak unit is 0.5 ns.
As described above, the distance resolution of the ranging result d2 and the ranging result d3 is smaller than that of the ranging result d1, that is, the ranging result d2 and the ranging result d3 have higher ranging accuracy than the ranging result d 1. Thereby increasing the ranging accuracy without a reduction in the actual time resolution of the time cell. The foregoing examples are only used to illustrate that the distance measurement method according to the embodiment of the present application has the effect of improving the distance measurement accuracy, and the degree of improvement of the distance measurement accuracy by the distance measurement method according to the embodiment of the present application is not limited to the degree of improvement illustrated in the foregoing examples. That is, in the above embodiments, in the time-of-flight histograms shown in fig. 6 and 7, the ranging accuracy of the ranging result d2 and the ranging result d3 is improved by at least 2 times compared with the ranging result d 1. The distance measurement method of the embodiment of the application is not limited to 2 times, but may be 3 times, 4 times or higher for improving the distance measurement accuracy.
The following is further described with reference to the accompanying drawings.
Referring to fig. 8, in some embodiments, 01: obtaining a time-of-flight histogram comprising:
011: acquiring a preset time period and a preset time resolution;
012: determining a plurality of time units according to the time period and the time resolution, wherein the time units are sequentially arranged on a time axis;
013: acquiring the arrival time of each photon at sensor 50;
014: determining a time unit corresponding to each photon according to the arrival time; and
015: and counting the number of photons corresponding to each time unit to establish a flight time histogram.
Referring to fig. 2, in some embodiments, the processor 30 may be further configured to implement the methods of 011, 012, 013, 014, and 015. That is, the processor 30 may also be configured to: acquiring a preset time period and a preset time resolution; determining a plurality of time units according to the time period and the time resolution, wherein the time units are sequentially arranged on a time axis; acquiring the arrival time of each photon at sensor 50; determining a 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.
Referring to fig. 3, in some embodiments, the obtaining module 11 may also be used to implement the methods of 011, 012, 013, 014, and 015. That is, the obtaining module 11 may also be configured to: acquiring a preset time period and a preset time resolution; determining a plurality of time units according to the time period and the time resolution, wherein the time units are sequentially arranged on a time axis; acquiring the arrival time of each photon at sensor 50; determining a 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.
The longer the preset time period is, the larger the maximum value of the flight time which can be determined according to the flight time histogram is, and the larger the ranging range is; the shorter the preset time period, the higher the ranging efficiency. When the preset time periods are the same, the larger the preset time resolution (the wider the width of the unit time), the peak value of the photon counting value can obviously appear in the flight time histogram by counting the number of photons for a few times, so that the ranging efficiency is improved; the smaller the preset time resolution (the narrower the width per unit time), the more accurate the time of flight that can be determined by means of the time of flight histogram and the more accurate the ranging result.
In certain embodiments, sensor 50 generates a response signal when sensor 50 receives a photon. The processor 30 records a response time stamp as the arrival time of the photon when receiving the response signal. After the arrival time of a photon is obtained, the time unit corresponding to the arrival time can be found in the flight time histogram, and the photon counting value corresponding to the time unit is increased by 1. For example, referring to fig. 4, if a certain arrival time is 0.2ns, the photon count value corresponding to the 1 st time unit is increased by 1 according to the time interval from 0ns to 0.5ns in the 0.2ns, i.e. the time interval of the 1 st time unit. And after multiple times of photon counting statistics, counting the number of corresponding photons in each time unit, namely counting the corresponding photon counting value in each time unit, taking the photon counting value as the height of the histogram of each time unit, and establishing a final flight time histogram.
Referring to FIG. 5, in some embodiments, the resolution of each time cell in the time-of-flight histogram is the same. Therefore, the difficulty of accumulating photon counting values in each time unit is the same, and the distance measurement can be carried out on any distance in the distance measurement range with the same distance measurement precision.
Referring to fig. 9, in some embodiments, the time-of-flight histogram includes a region of interest and a region of non-interest, the resolution of the time unit of the region of interest being less than the resolution of the time unit of the region of non-interest. The interesting region is a time interval determined according to the interesting distance (the tested subject is in the interesting distance range), and the non-interesting region is a time interval outside the interesting region in the flight time histogram, namely a time interval determined according to the non-interesting distance (the tested subject is outside the non-interesting distance range). The smaller the resolution of a time cell, the more accurate the time of flight determined from that time cell, enabling ranging at a distance of interest with greater detection accuracy. For example, in the time-of-flight histogram illustrated in fig. 9, the time interval from 1ns to 2ns is the region of interest, the 2 nd and 3 rd time cells are the time cells of the region of interest, and the corresponding time resolution is 0.5 ns. Time intervals outside the time intervals from 1ns to 2ns are regions of non-interest, and the time resolution corresponding to the time unit of the regions of non-interest is 1 ns. Compared with the non-interested area, the time unit of the interested area has smaller resolution, more time units are divided in the same time interval, and the flight time determined according to the time unit of the interested area is more accurate. And the time resolution corresponding to the time unit of the non-interested region is set to be larger, so that the ranging efficiency can be improved.
Referring to fig. 10, in some embodiments, 02: determining a peak cell and a plurality of neighborhood cells from the time cells based on the time-of-flight histogram, comprising:
021: acquiring a photon count value corresponding to each time unit;
022: determining a time unit corresponding to the maximum photon counting value as a peak value unit; and
023: at least one time cell adjacent to the left side of the peak cell and at least one time cell adjacent to the right side of the peak cell in the time-of-flight histogram are determined as neighborhood cells.
Referring to fig. 2, in some embodiments, the processor 30 can also be used to implement the methods of 021, 022 and 023. That is, the processor 30 may also be configured to: acquiring a photon count value corresponding to each time unit; determining a time unit corresponding to the maximum photon counting value as a peak value unit; and determining at least one time cell adjacent to the left side of the peak cell and at least one time cell adjacent to the right side of the peak cell in the time-of-flight histogram as neighborhood cells.
Referring to fig. 3, in some embodiments, the retrieving module 12 can also be used to implement the methods of 021, 022 and 023. That is, the retrieval module 12 may also be configured to: acquiring a photon count value corresponding to each time unit; determining a time unit corresponding to the maximum photon counting value as a peak value unit; and determining at least one time cell adjacent to the left side of the peak cell and at least one time cell adjacent to the right side of the peak cell in the time-of-flight histogram as neighborhood cells.
Referring to fig. 5, the ordinate of the square bar of each time unit is the photon count value corresponding to the time unit. The vertical coordinate of the square column with the highest height along the vertical axis direction is the maximum photon count value, and the time unit corresponding to the square column is the peak value unit. The neighborhood cells are time cells adjacent to the peak cell, and include at least one left neighborhood cell to the left of the peak cell and at least one right neighborhood cell to the right of the peak cell. The number of left-neighbor cells may be 1, 2, 3, or more, which are not enumerated here. When the number of the left neighborhood units is 1, the left neighborhood unit is the nearest time unit on the left side of the peak value unit; when the number of the left adjacent domain units is n (n is more than 1), the left adjacent domain units are n time units which are distributed along the left side of the horizontal axis in sequence from the nearest time unit on the left side of the peak value unit. The number of right neighborhood cells may be 1, 2, 3, or more, and is not enumerated here. In one embodiment, the neighborhood of cells includes 1 left neighborhood of cells and 1 right neighborhood of cells, such as in the time-of-flight histogram illustrated in FIG. 5, the 3 rd time cell is the peak cell and the 2 nd and 4 th time cells are the neighborhood of cells. At the moment, the time unit number of the neighborhood units is the least, and the data processing amount is less when the flight time is determined according to the parameter value of the peak unit and the parameter values of the plurality of neighborhood units, so that the ranging efficiency is higher.
Referring to FIG. 11, in some embodiments, the parameter values include a resolution of the time cell, a photon count value corresponding to the time cell, and a chronological order of occurrence of the time cell. 03: determining a time of flight according to the parameter values of the peak cell and the parameter values of the plurality of neighborhood cells, comprising:
031: acquiring a peak value count value corresponding to a peak value unit, a left count value corresponding to a left adjacent domain unit and a right count value corresponding to a right adjacent domain unit;
032: determining a correction value according to the peak value count value, the left count value, the right count value and a preset correction parameter; and
033: and determining the flight time according to the resolution of the peak unit, the serial number of the peak unit and the correction value.
Referring to fig. 2, in some embodiments, the processor 30 may also be used to implement the methods 031, 032 and 033. That is, the processor 30 may also be configured to: acquiring a peak value count value corresponding to a peak value unit, a left count value corresponding to a left adjacent domain unit and a right count value corresponding to a right adjacent domain unit; determining a correction value according to the peak value count value, the left count value, the right count value and a preset correction parameter; and determining the flight time according to the resolution of the peak unit, the serial number of the peak unit and the correction value.
Referring to fig. 3, in some embodiments, the determining module 13 can also be used to implement the methods in 031, 032 and 033. That is, the determining module 13 may be further configured to: acquiring a peak value count value corresponding to a peak value unit, a left count value corresponding to a left adjacent domain unit and a right count value corresponding to a right adjacent domain unit; determining a correction value according to the peak value count value, the left count value, the right count value and a preset correction parameter; and determining the flight time according to the resolution of the peak unit, the serial number of the peak unit and the correction value.
Referring to FIGS. 6 and 7, and in conjunction with the above, the time of flight can be based on the time t at which the photon is emittedLaunchingAnd the time t at which the sensor 50 receives photons reflected back from the objectReceivingDetermining, i.e. time of flight t ═ tReceiving-tLaunching. In some embodiments, the median time t0 of the peak unit is taken as tReceivingTo determine the time of flight t1 based on the peak cells. Since the median time t0 of the peak cells depends on the time resolution corresponding to the peak cells, the smaller the time resolution corresponding to the peak cells, the more accurate the median time t0 can be determined. Therefore, in the case where the resolution of the peak cell is limited and cannot be reduced, the peak cell has a fixed median time t0, and the accuracy of the time of flight t1 determined from the median time t0 is limited.
The ranging method can determine the correction value according to the peak value numerical value, the left counting value, the right counting value and the preset correction parameter, and determine the flight time according to the resolution of the peak unit, the serial number of the peak unit and the correction value, so that the precise higher flight time is determined. When the peak value unit is the nth time unit on the horizontal axis of the flight time histogram, the serial number of the peak value unit is n. The correction parameter is a preset constant value and represents the influence of the peak count value, the left count value and the right count value on the correction value. The correction value can characterize the time t at which the sensor 50 receives a photon reflected back from the objectReceivingOffset from the peak unit. The correction value may take the form of a positive value, a negative value, or 0. When the correction value is positive, the time t at which the sensor 50 receives a photon reflected back from the object is characterizedReceivingTo the right of the median time t0 of the peak unit, i.e. tReceiving> t 0; when the correction value is negative, the time t is characterizedReceivingTo the left at time t0, i.e. tReceiving< t 0; when the correction value is 0, the characterization may take the median time t0 of the peak unit as tReceivingI.e. tReceiving＝t0。
For example, if the peak unit has a serial number of 41 and the correction value is-0.45, then the corrected serial number is 40.55, and the time t when the sensor 50 receives the photon reflected from the object can be determinedReceivingTo the left of the peak cell's median time t 0. In the flight time histogram, the sequence numbers n of all time units are positive integers, and the time unit with the sequence number of 40.55 does not actually exist in the flight time histogram, but does not influence the time t determined based on the time unit with the sequence number of 40.55ReceivingTo determine the time of flight. In one embodiment, the time resolution of each time unit is the same, and the median time tn ' of the time unit with the sequence number of 40.55 may be determined in combination with the time resolution, for example, the time resolution is 0.5ns, and then tn ' is 0.5ns × 40.55- (0.5ns/2) ═ 20.025ns, and tn ' is taken as the time t when the sensor 50 receives the photon reflected from the objectReceivingTo determine the time of flight.
Referring to fig. 12, in some embodiments, the calibration parameters include a first parameter, a second parameter and a third parameter. 032: determining a correction value according to the peak count value, the left count value, the right count value and a preset correction parameter, wherein the method comprises the following steps:
0321: obtaining a weighted peak value count value according to the peak value count value and the first parameter;
0322: acquiring a weighted right count value according to the right count value and a second parameter;
0323: obtaining a weighted left count value according to the left count value and a third parameter;
0324: acquiring a first difference value between a right count value and a left count value;
0325: acquiring a second difference value obtained by sequentially subtracting the weighted peak value from the weighted right count value and the weighted left count value; and
0326: and acquiring the ratio of the first difference to the second difference, and determining the ratio as a correction value.
Referring to fig. 2, in some embodiments, processor 30 may also be used to implement the methods in 0321, 0322, 0323, 0324, 0325 and 0326. That is, the processor 30 may also be configured to: obtaining a weighted peak value count value according to the peak value count value and the first parameter; acquiring a weighted right count value according to the right count value and a second parameter; obtaining a weighted left count value according to the left count value and a third parameter; acquiring a first difference value between a right count value and a left count value; acquiring a second difference value obtained by sequentially subtracting the weighted peak value from the weighted right count value and the weighted left count value; and acquiring the ratio of the first difference to the second difference, and determining the ratio as a correction value.
Referring to fig. 3, in some embodiments, determination module 13 can also be used to implement the methods in 0321, 0322, 0323, 0324, 0325 and 0326. That is, the determining module 13 may be further configured to: obtaining a weighted peak value count value according to the peak value count value and the first parameter; acquiring a weighted right count value according to the right count value and a second parameter; obtaining a weighted left count value according to the left count value and a third parameter; acquiring a first difference value between a right count value and a left count value; acquiring a second difference value obtained by sequentially subtracting the weighted peak value from the weighted right count value and the weighted left count value; and acquiring the ratio of the first difference to the second difference, and determining the ratio as a 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. From this, it can be calculated: the weighted peak count value Pq1 ═ a × P1, the weighted right count value Pq2 ═ b × P2, the weighted left count value Pq3 ═ c × P3, the first difference value F1 ═ P2-P3, the second difference value F2 ═ Pq1-Pq2-Pq3 ═ a × P1-b × P2-c × P3. If the correction value is Δ n, then
The first parameter a, the second parameter b and the third parameter c are all preset constants and can be obtained according to calibration before delivery.
Referring to fig. 13, in some embodiments, 033: determining the flight time according to the resolution of the peak unit, the serial number of the peak unit and the correction value, comprising:
0331: and determining a correction number of the peak unit according to the number of the peak unit and the correction value, and determining the flight time according to the correction number and the resolution of the peak unit.
Referring to fig. 2, in some embodiments, the processor 30 may also be used to implement the method 0331. That is, the processor 30 may also be configured to: and determining a correction number of the peak unit according to the number of the peak unit and the correction value, and determining the flight time according to the correction number and the resolution of the peak unit.
Referring to fig. 3, in some embodiments, the determination module 13 may also be used to implement the method 0331. That is, the determining module 13 may be further configured to: and determining a correction number of the peak unit according to the number of the peak unit and the correction value, and determining the flight time according to the correction number and the resolution of the peak unit.
Specifically, if the number of the peak unit is n and the correction value is Δ n, the correction number n' ═ n +/Δ n. As described above, Δ n may be positive, negative, or 0.
Referring to fig. 6, in one embodiment, the actual distance between the sensor 50 and the object is 3m, and the time-of-flight histogram is obtained after statistics: the number n of the peak unit is 41, the correction value Δ n is-0.45, and the time resolution K of the peak unit is 0.5 ns. From this, it can be calculated: the correction index n' ═ n +. DELTA.n ═ 41+ (-0.45) ═ 40.55. Let the time of flight be t, t ═ tReceiving-tLaunchingWherein, tLaunchingIs the time of emission of a photon, tReceivingIs the time at which the sensor 50 receives photons reflected back from the object. In the time-of-flight histogram of the present embodiment, the photon count value is counted from the time when the photon is emitted, and therefore tLaunching0ns, tReceiving. And t isReceivingCan be determined according to the following formula: t is tReceivingN' × K- (K/2). Wherein, n ' × K represents the time corresponding to the right end point coordinate of the corrected peak unit on the time axis, and K/2 is half of the time resolution, namely n ' × K- (K/2) represents the median time of the nth ' time unit. Substituting n' into 40.55, K into 0.5ns into tReceivingN' x K- (K/2), the time of flight t may be calculatedReceivingN' × K- (K/2) ═ 40.55 × 0.5ns- (0.5ns/2) ═ 20.025 ns. Thus, in combination with 04: calculating the distance between the sensor 50 and the object according to the flight time and the speed of light, and changing t to 20.025ns20.025×10-9s，c＝3×108Substitution of m/s
The distance d can be calculated as (20.025 × 10)-9s×3×108m/s)/2＝3.00375m。
In contrast, the time of flight t1, which is determined based only on the parameter values of the peak unit, is 41 × 0.5ns- (0.5ns/2) 20.25 ns. The distance d1 obtained from the time of flight t1 is (20.25 × 10)-9s×3×108m/s)/2 is 3.0375 m. It can be seen that d calculated from the time of flight t is closer to the actual distance between the sensor 50 and the object than d1 calculated from the time of flight t1, so that the time of flight is determined from the resolution of the peak cells, the number of the peak cells and the correction value, enabling a more accurate time of flight to be determined.
Further, in the present embodiment (the embodiment illustrated in fig. 6), when the time resolution K of the peak unit has been determined to be 0.5ns, the distance resolution H of the peak unit is 0.5ns × 3 × 108If the time of flight t1 is determined solely from the parameter values of the peak cells, the actual distance between the sensor 50 and the object is [3.000m, 3.075m ═ 0.075m]At any value in the range, the flight time t1 determined according to the parameter value of the peak unit is 20.25ns, the measurement distance d1 determined according to the flight time t is 3.0375m, and the maximum error is 0.0375 m. The magnitude of the time-of-flight t determined from the resolution of the peak cells, the number of the peak cells and the correction value is related to the correction value Δ n, which is related to the parameter value of the peak cells, the parameter value of the left-adjacent-domain cell, and the parameter value of the right-domain cell, and can characterize the time t at which the sensor 50 receives the photons reflected from the objectReceivingThe degree of shift in the peak cell to the left neighbor cell or the right neighbor cell. In this embodiment, when Δ n is less than 0, the range of the time of flight t is [20.00ns, 20.25ns ], the range of the distance d that can be determined according to the value of the time of flight t is [3.0000m, 3.0375m), and the maximum error is less than 0.0375 m; when Deltan is more than 0, the value range of the flight time t is (20.25ns, 20.50 ns)]The range of the distance d that can be determined from the value of the time of flight t is (3.0)375m，3.0750m]The maximum error is less than 0.0375 m. That is, when Δ n is not 0, the accuracy of time-of-flight t is improved compared to time-of-flight t1, and the accuracy of measured distance d determined by time-of-flight t is improved compared to measured distance d1 determined by time-of-flight t 1.
Referring to fig. 14, in some embodiments, 033: determining the flight time according to the resolution of the peak unit, the serial number of the peak unit and the correction value, comprising:
0332: determining peak time according to the serial number and resolution of the peak unit, determining correction time according to the correction value and resolution, and determining flight time according to the peak time and the correction time.
Referring to fig. 2, in some embodiments, the processor 30 may also be used to implement the method 0332. That is, the processor 30 may also be configured to: determining peak time according to the serial number and resolution of the peak unit, determining correction time according to the correction value and resolution, and determining flight time according to the peak time and the correction time.
Referring to fig. 3, in some embodiments, the determination module 13 may also be used to implement the method 0332. That is, the determining module 13 may be further configured to: determining peak time according to the serial number and resolution of the peak unit, determining correction time according to the correction value and resolution, and determining flight time according to the peak time and the correction time.
Referring to fig. 6, specifically, let the number of the peak unit be n, the time resolution of each time unit be K, and the correction value be Δ n. When the median time t0 of the peak cell is taken as the peak time tn corresponding to the peak cell, the peak time tn can be calculated to be n × K- (K/2). In some embodiments, any time tr in the peak unit may be taken as the peak time tn corresponding to the peak unit, and then the peak time tn may be calculated as n × K- (K × u), where u is a ratio of a time period from the time tr to a right end time of the peak unit to the time resolution K, for example, when the time tr is a median time of the peak unit, u is 1/2. The correction time Δ t is Δ n × K, and the flight time t is tn + Δ t. In some embodiments, the correspondence between the sequence number of each time cell and the time instance to which the time cell corresponds has been determined at the time of creation of the time-of-flight histogram and stored in memory 20. When a certain time unit is determined as a peak value unit, the peak value time tn can be determined according to the serial number of the peak value unit and the corresponding relation, so that the calculation is simplified, and the ranging efficiency is improved.
Referring to fig. 15, in some embodiments, 033: determining the flight time according to the resolution of the peak unit, the serial number of the peak unit and the correction value, comprising:
0333: and determining the correction number of the peak unit according to the number of the peak unit and the correction value, and taking the time corresponding to the correction number on the flight time histogram as the flight time.
Referring to fig. 2, in some embodiments, the processor 30 may also be used to implement the method 0333. That is, the processor 30 may also be configured to: and determining the correction number of the peak unit according to the number of the peak unit and the correction value, and taking the time corresponding to the correction number on the flight time histogram as the flight time.
Referring to fig. 3, in some embodiments, the determination module 13 may also be used to implement the method of 0333. That is, the determining module 13 may be further configured to: and determining the correction number of the peak unit according to the number of the peak unit and the correction value, and taking the time corresponding to the correction number on the flight time histogram as the flight time.
Referring to fig. 6, specifically, let the number of the peak unit be n, and the correction value be Δ n. The correction number n' ═ n +. DELTA.n can be calculated. In connection with the foregoing, the photon count values are counted in the time-of-flight histogram starting from the moment the photon is emitted, hence tLaunching0ns, tReceiving. In some embodiments, the modified peak time tn 'of the peak unit (i.e., time unit numbered n') is taken as tReceiving. In the time-of-flight histogram, the peak time tn ' of the time cell with the number n ' is expressed as a time corresponding to the time axis of the time-of-flight histogram for the time cell with the number n '. The sequence number of each time unit and the time corresponding to the time unit on the time axis are determined when the flight time histogram is establishedAnd stores the correspondence in the memory 20. After the number n 'of the corrected peak value unit is determined, the peak value time tn' can be determined according to the number n 'and the corresponding relation, and the flight time t is tn', so that the calculation is simplified, and the ranging efficiency is improved.
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 disclosure, when the computer program 301 is executed by one or more processors 30, causes the processors 30 to perform the ranging method according to any of the above embodiments, for example, one or more of steps 01, 02, 03, 04, 011, 012, 013, 014, 015, 021, 022, 023, 031, 032, 033, 0321, 0322, 0323, 0324, 0325, 0326, 0331, 0332, and 0333 are implemented.
For example, the computer program 301, when executed by the one or more processors 30, causes the processors 30 to perform the steps of:
01: acquiring a flight time histogram, wherein the flight time histogram represents the number of photons received by the sensor in each time unit;
02: determining a peak unit and a plurality of neighborhood units from the time units according to the flight time histogram;
03: determining flight time according to the parameter values of the peak unit and the parameter values of the plurality of neighborhood units; and
04: and calculating the distance between the sensor and the object according to the flight time and the light speed.
As another example, the computer program 301, when executed by the one or more processors 30, causes the processors 30 to perform the steps of:
011: acquiring a preset time period and a preset time resolution;
012: determining a plurality of time units according to the time period and the time resolution, wherein the time units are sequentially arranged on a time axis;
013: acquiring the arrival time of each photon at the sensor;
014: determining a time unit corresponding to each photon according to the arrival time;
015: counting the number of photons corresponding to each time unit to establish a flight time histogram;
021: acquiring a photon count value corresponding to each time unit;
022: determining a time unit corresponding to the maximum photon counting value as a peak value unit;
023: determining at least one time cell adjacent to the left side of the peak cell and at least one time cell adjacent to the right side of the peak cell in the time-of-flight histogram as neighborhood cells;
031: acquiring a peak value count value corresponding to a peak value unit, a left count value corresponding to a left adjacent domain unit and a right count value corresponding to a right adjacent domain unit;
032: determining a correction value according to the peak value count value, the left count value, the right count value and a preset correction parameter; and
033: determining the flight time according to the resolution of the peak unit, the serial number of the peak unit and the correction value;
04: the distance between the sensor 50 and the object is calculated from the time of flight and the speed of light.
In the description herein, reference to the description of the terms "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example" or "some examples" or the like means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Moreover, various embodiments or examples and features of various embodiments or examples described in this specification can be combined and brought together by those skilled in the art without contradiction.
Any process or method descriptions in flow charts or otherwise described herein may be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps of the process, and the scope of the preferred embodiments of the present application includes other implementations in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the present application.
Although embodiments of the present application have been shown and described above, it is to be understood that the above embodiments are exemplary and not to be construed as limiting the present application, and that variations, modifications, substitutions and alterations may be made to the above embodiments by those of ordinary skill in the art within the scope of the present application.
Claims (10)
1. A method of ranging, comprising:
acquiring a flight time histogram, wherein the flight time histogram represents the number of photons received by a sensor in each time unit;
determining a peak cell and a plurality of neighborhood cells from the time cells according to the time-of-flight histogram;
determining flight time according to the parameter values of the peak unit and the parameter values of the plurality of neighborhood units; and
and calculating the distance between the sensor and the object according to the flight time and the light speed.
2. The ranging method of claim 1, wherein the obtaining a time-of-flight histogram comprises:
acquiring a preset time period and a preset time resolution;
determining a plurality of time units according to the time periods and the time resolution, wherein the time units are sequentially arranged on a time axis;
acquiring the arrival time of each photon at the sensor;
determining a time unit corresponding to each photon according to the arrival time; and
and counting the number of photons corresponding to each time unit to establish the flight time histogram.
3. The ranging method of claim 1,
the resolution of each time cell in the time-of-flight histogram is the same; or
The time-of-flight histogram includes a region of interest and a region of non-interest, the resolution of the time unit of the region of interest being less than the resolution of the time unit of the region of non-interest.
4. The method of claim 1, wherein determining a peak cell and a plurality of neighborhood cells from the time cell based on the time-of-flight histogram comprises:
acquiring a photon count value corresponding to each time unit;
determining a time unit corresponding to the maximum photon count value as the peak value unit; and
determining at least one time cell in the time-of-flight histogram that is adjacent to the left of the peak cell and at least one time cell that is adjacent to the right of the peak cell as the neighborhood cell.
5. The method of claim 1, wherein the neighborhood cells comprise a left neighborhood cell located to the left of the peak cell and a right neighborhood cell located to the right of the peak cell, and the parameter values comprise a resolution of the time cell, a photon count value corresponding to the time cell, and a sequence number of the time cell occurring in time order; said determining time of flight from said peak cell and a plurality of said neighbor cells comprises:
acquiring a peak value count value corresponding to the peak value unit, a left count value corresponding to the left neighborhood unit and a right count value corresponding to the right neighborhood 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
and determining the flight time according to the resolution of the peak unit, the serial number of the peak unit and the correction value.
6. The ranging method according to claim 5, wherein the correction parameters comprise a first parameter, a second parameter and a third parameter, and the determining a correction value according to the peak count value, the left count value, the right count value and a preset correction parameter comprises:
obtaining a weighted peak value count value according to the peak value count value and the first parameter;
acquiring 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;
acquiring a first difference value between the right count value and the left count value;
acquiring a second difference value obtained by sequentially subtracting the weighted peak value from the weighted right count value and the weighted left count value; and
and acquiring the ratio of the first difference to the second difference, and determining the ratio as the correction value.
7. The method of claim 5, wherein the determining the time of flight according to the resolution of the peak unit, the sequence number of the peak unit, and the correction value comprises:
determining a correction serial number of the peak unit according to the serial number of the peak unit and the correction value, and determining the flight time according to the correction serial number and the resolution of the peak unit; or
Determining a peak value moment according to the serial number of the peak value unit and the resolution, determining correction time according to the correction value and the resolution, and determining the flight time according to the peak value moment and the correction time; or
And determining a correction serial number of the peak unit according to the serial number of the peak unit and the correction value, and taking the time corresponding to the correction serial number on the flight time histogram as the flight time.
8. A ranging apparatus, comprising:
the acquisition module is used for acquiring a flight time histogram which represents the number of photons received by the sensor in each time unit;
a retrieval module to determine a peak cell and a plurality of neighborhood cells from the time cells according to the time-of-flight histogram;
a determining module for determining a time of flight according to the parameter value of the peak cell and the parameter values of the plurality of neighbor cells; and
and the calculation module is used for calculating the distance between the sensor and the object according to the flight time and the light speed.
9. A terminal, characterized in that the terminal comprises:
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 comprising instructions for performing the ranging method of any of claims 1 to 7.
10. A non-transitory computer readable storage medium containing a computer program which, when executed by one or more processors, causes the processors to implement the ranging method of any one of claims 1 to 7.
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| CN115546079A (en) * | 2022-11-25 | 2022-12-30 | 杭州宇称电子技术有限公司 | TOF histogram dynamic range expanding method and application thereof |
| WO2023000756A1 (en) * | 2021-07-20 | 2023-01-26 | Oppo广东移动通信有限公司 | Ranging method and apparatus, terminal, and non-volatile computer-readable storage medium |
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