CN112147626A

CN112147626A - Electronic device, control method of electronic device, and computer-readable storage medium

Info

Publication number: CN112147626A
Application number: CN202010962535.2A
Authority: CN
Inventors: 张学勇
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2020-09-14
Filing date: 2020-09-14
Publication date: 2020-12-29
Also published as: WO2022052606A1

Abstract

An electronic device, a control method of the electronic device, and a computer-readable storage medium are disclosed. The control method comprises the following steps: emitting light pulses towards the target object; receiving photons; recording the time of arrival of said photon at said receiver; recording the number of times the receiver receives photons in each time unit; and when the emission times of the optical pulses are smaller than a preset first threshold value and the times of receiving photon signals by the receiver in the time unit are larger than a preset second threshold value, controlling the emitter to stop emitting the optical pulses. The control method of the embodiment of the application can reduce the power consumption of the ranging system when the ranging distance is short.

Description

Electronic device, control method of electronic device, and computer-readable storage medium

Technical Field

The present application relates to the field of ranging, and more particularly, to an electronic device, a control method of the electronic device, and a non-volatile computer-readable storage medium.

Background

With the development of technologies, electronic devices such as mobile phones and tablet computers have more and more functions, such as face unlocking, mobile payment, and the like. To achieve these functions, a ranging system, such as a direct Time of Flight (dTOF) ranging system, is configured on the electronic devices for ranging. To obtain better imaging effect, (Directed Time of Flight, dTOF) technology is introduced into the imaging system of the electronic device. While a good imaging effect is obtained by dTOF, how to reduce the power consumption of dTOF becomes a problem to be solved.

Disclosure of Invention

The embodiment of the application provides an electronic device, a control method of the electronic device and a nonvolatile computer readable storage medium.

The electronic device of the embodiment of the application comprises: the device comprises a transmitter, a receiver, a time-to-digital converter, a comparator and a controller, wherein the transmitter is used for transmitting light pulses to a target object. The receiver is for receiving photons. The time-to-digital converter is used to record the time at which the photon arrives at the receiver. The comparator records the number of times the receiver receives a photon in each time cell. The controller is used for controlling the emitter to stop emitting the light pulses when the emitting times of the light pulses are smaller than a preset first threshold and the receiving times of the receiver in any time unit are larger than a preset second threshold.

The control method of the electronic device of the embodiment of the application comprises the following steps: emitting light pulses towards the target object; receiving photons; recording the time of arrival of said photon at said receiver; recording the number of times the receiver receives photons in each time unit; and when the emission times of the optical pulses are smaller than a preset first threshold value and the times of receiving photon signals by the receiver in the time unit are larger than a preset second threshold value, controlling the emitter to stop emitting the optical pulses.

The electronic device of the embodiment of the application comprises: an emitter, a receiver, a time-dependent photon counting system, and a controller. The emitter is used for emitting light pulses. The receiver is used for detecting photons in the light pulses reflected back by the object in a preset detection period and forming photon signals, and the detection period comprises a plurality of time units. The time-dependent photon counting system is used for counting on a time unit corresponding to the detection period when the photon signal is formed; counting the count of the photon signals in each detection period once, thereby counting the counts of the photon signals in a plurality of detection periods a plurality of times to output a histogram of count values with respect to time and the counts of the photon signals; and processing the histogram to obtain distance information. The controller is used for stopping transmitting the light pulse when the counting times are less than a preset first threshold value and the counting value on any time unit is greater than a preset second threshold value

The control method of the electronic device of the embodiment of the application comprises the following steps: emitting a light pulse; detecting photons in the optical pulses reflected back by an object within a preset detection period and forming photon signals, wherein the detection period comprises a plurality of time units; counting over time units corresponding to the detection periods when the photon signals are formed; counting the count of the photon signals in each of the detection periods once, thereby counting the count of the photon signals in a plurality of the detection periods a plurality of times to output a histogram of count values with respect to time and the count of the photon signals; when the counting times are smaller than a preset first threshold value and the counting value on any one time unit is larger than a preset second threshold value, stopping transmitting the light pulse; and processing the histogram to obtain the distance information.

The non-transitory computer-readable storage medium of the embodiments of the present application contains a computer program that, when executed by one or more processors, causes the processors to implement a control method of: emitting a light pulse; detecting photons in the optical pulses reflected back by an object within a preset detection period and forming photon signals, wherein the detection period comprises a plurality of time units; counting over time units corresponding to the detection periods when the photon signals are formed; counting the count of the photon signals in each of the detection periods once, thereby counting the count of the photon signals in a plurality of the detection periods a plurality of times to output a histogram of count values with respect to time and the count of the photon signals; when the counting times are smaller than a preset first threshold value and the counting value on any one time unit is larger than a preset second threshold value, stopping transmitting the light pulse; and processing the histogram to obtain the distance information. The processor can also realize the following control method: detecting photons in the optical pulses reflected back by an object within a preset detection period and forming photon signals, wherein the detection period comprises a plurality of time units; counting over time units corresponding to the detection periods when the photon signals are formed; counting the count of the photon signal in each detection period once, thereby counting the count of the photon signal in a plurality of detection periods a plurality of times to output a histogram of count values with respect to time and the count of the photon signal, and comparing whether the count value in each time unit in the previous detection period is greater than the preset second threshold before each emission of a light pulse; when the counting times are smaller than a preset first threshold value and the counting value on any one time unit is larger than a preset second threshold value, stopping transmitting the light pulse; and processing the histogram to obtain the distance information.

The electronic device, the control method of the electronic device, and the computer-readable storage medium according to the embodiments of the present application can reduce the actual number of times of statistics or the number of times of transmitting light pulses on the basis of obtaining more accurate distance information when the distance measurement distance is short, so as to save laser energy, reduce power consumption of a distance measurement system, and shorten the time for distance measurement.

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 embodiments 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 method for controlling an electronic device according to some embodiments of the present disclosure;

fig. 2 to 3 are schematic structural diagrams of a distance measuring system in an electronic device according to some embodiments of the present disclosure;

fig. 4 to 5 are schematic views illustrating a ranging scenario performed by a ranging system in an electronic device according to some embodiments of the present disclosure;

FIG. 6 is a schematic structural diagram of an electronic device according to some embodiments of the present application;

FIG. 7 is a schematic flow chart diagram illustrating a method for controlling an electronic device according to some embodiments of the present disclosure;

FIG. 8 is a statistical graph of count values with respect to time and counting of photon signals according to certain embodiments of the present application;

fig. 9 is a schematic flow chart illustrating a control method of an electronic device according to some embodiments of the present disclosure;

FIG. 10 is a statistical graph of count values with respect to time and counting of photon signals according to certain embodiments of the present application;

11-12 are histograms of count values with respect to time and count of photon signals for certain embodiments of the present application;

FIG. 13 is a graphical illustration of the number of times a light pulse is emitted versus distance for certain embodiments of the present application;

fig. 14 is a schematic flow chart illustrating a control method of an electronic device according to some embodiments of the present disclosure;

fig. 15 to 16 are schematic flow charts illustrating a control method of an electronic device according to some embodiments of the present disclosure;

fig. 17 to 19 are schematic flow charts illustrating a control method of an electronic device according to some embodiments of the present disclosure;

FIG. 20 is a statistical graph of count values with respect to time and counting of photon signals according to certain embodiments of the present application;

fig. 21 is a schematic flow chart illustrating a control method of an electronic device according to some embodiments of the present disclosure;

FIG. 22 is a graphical illustration of statistics versus distance for certain embodiments of the present application;

fig. 23 to 24 are schematic flow charts illustrating a control method of an electronic device according to some embodiments of the present disclosure;

FIG. 25 is a schematic diagram of a connection state of 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.

Referring to fig. 1, fig. 2 and fig. 6, an embodiment of the present disclosure provides an electronic device 1000 and a control method applied to the electronic device 1000. The control method of the electronic device 1000 includes:

01: emitting a light pulse toward the target object 50;

02: receiving photons;

03: recording the time of arrival of the photon at the receiver 20;

04: recording the number of times the receiver 20 receives photons in each time unit; and

05: and when the emission times of the optical pulses are smaller than a preset first threshold and the times of receiving the photon signals by the receiver in the time unit are larger than a preset second threshold, controlling the emitter to stop emitting the optical pulses.

Referring to fig. 2, an electronic device 1000 according to an embodiment of the present disclosure includes a distance measuring system 100. The ranging system 100 includes a transmitter 10, a receiver 20, a controller 30, a time-to-digital converter (TDC) 41, a comparator 42, and a processor 43. The control method of the electronic device 1000 may be applied to the ranging system 100, and specifically, the transmitter 10 may be used to perform the method in 01. The receiver 20 may be used to perform the method in 02. The time-to-digital converter 41 may be used to perform the method in 03. Comparator 42 may be used to perform the method in 04. The controller 30 may be used to execute the method of 05. That is, the transmitter 10 may be used to transmit light pulses to the target object 50. The receiver 20 may be used to receive photons. A time-to-digital converter 41 may be used to record the time at which the photon arrived at the receiver 20. The comparator 42 may be used to record the number of times the receiver 20 receives a photon in each time cell. The controller 30 may be configured to control the transmitter to stop transmitting the optical pulses when the number of times of transmitting the optical pulses is smaller than a preset first threshold and the number of times of receiving the photon signals by the receiver in the time unit is larger than a preset second threshold.

The electronic device 1000 may be, but is not limited to, a mobile phone, a tablet computer, a notebook computer, a smart watch, a game machine, a head display device, a laser ruler, etc., and among these electronic devices, the distance measuring system 100 is often provided to achieve the distance measuring function. Specifically, the ranging system 100 may be a dTOF ranging system, which may establish a distribution function of photons over time through a time-dependent photon counting technique, i.e., establish a histogram with respect to time and the number of times the receiver 20 receives photons (count value of count of photon signals), and acquire distance information of an object by performing data processing on the histogram.

Referring to fig. 4, when it is required to measure the distance between the electronic device 1000 and the object 50, light pulses are emitted from the emitter 10 to the target object 50 at a predetermined period. The receiver 20 detects photons in the light pulses reflected back by the object 50. A preset period includes a plurality of time units, the time-to-digital converter 41 records in which time unit the time when the photon reaches the receiver 20 is, the comparator 42 records the number of times that the receiver 20 receives the photon in each time unit, and when the number of times that the optical pulse is emitted is smaller than a preset first threshold and the number of times that the receiver 20 receives the photon in any one of the time units is larger than a preset second threshold, the controller 30 controls the emitter 10 to stop emitting the optical pulse to save energy. When the number of times of receiving photons is greater than the preset second threshold, it indicates that the photon signal strength is sufficient in the current ranging environment, and the photons are relatively easy to detect, and this ranging environment is often a ranging environment closer to the object 50 to be measured. Therefore, when the distance measurement is short, the actual emission times of the emitter 10 for emitting the light pulse can be reduced on the basis of obtaining the accurate distance information, so that the laser energy is saved, the power consumption of the distance measurement system 100 is reduced, and the length of time for measuring the distance is shortened.

Referring to fig. 2 and 4, in one embodiment, the comparator 42 may be disposed in the time-to-digital converter 41, so that the integration degree of the two is relatively high, and the two are conveniently purchased from the same manufacturer.

Referring to fig. 3 and 5, in another embodiment, the comparator 42 may be disposed independently from the time-to-digital converter 41, and the two are disposed separately, so that when one of the comparators 42 or the time-to-digital converter 41 is damaged, for example, the damaged comparator 42 or the time-to-digital converter 41 is damaged, a new replacement may be performed for the damaged comparator 42 or the time-to-digital converter 41, and the whole comparator or the time-to-digital converter is not required to be replaced, thereby saving the cost.

Referring to fig. 2, in some embodiments, the emitter 10 includes a Vertical-Cavity Surface-Emitting Laser (VCSEL), an edge-Emitting semiconductor Laser (EEL), a Light Emitting Diode (LED), and other Light sources. These light sources may be point light sources consisting of a single laser or diode, or may be array light sources consisting of a plurality of lasers or diodes. The transmitter 10 can transmit pulses of light at a frequency to the object 50 under the control of the pulse driver 33 for use in the measurement of dTOF ranging.

In some embodiments, the receiver 20 includes a Single Photon Avalanche Diode (SPAD), or an array of multiple SPADs, for detecting photons in the pulse reflected back by the object 50 and forming a Photon signal. The SPAD is capable of responding to a single photon in the reflected pulse, and the single photon incident on the SPAD generates a very distinct avalanche signal, i.e. a photon signal. Each time the SPAD outputs a photon signal to the comparator 42, the number of received photons recorded by the comparator 42 is increased by 1.

Referring to fig. 7, in some embodiments, 04: recording the number of times that the receiver receives photons in each time unit, comprising:

041: the number of times that the receiver 20 receives photons in each time unit is recorded every time a light pulse is transmitted, wherein when the receiver 20 does not receive photons, the number of times that the receiver 20 receives photons in each time unit is recorded as zero, and when the receiver 20 receives photons in a certain time unit, the number of times that the receiver 20 receives photons in the time unit is increased by one, so as to obtain the number of times that the receiver 20 receives photons in each time unit after multiple light pulses are transmitted.

Referring again to fig. 3 and 4, in some embodiments, the time-to-digital converter 41 is also used for executing the method 041. That is, the time-to-digital converter 41 is further configured to record the number of times that the receiver 20 receives the photon in each time unit every time the light pulse is transmitted, where the number of times that the receiver 20 receives the photon in each time unit is recorded as zero when the receiver 20 does not receive the photon, and the number of times that the receiver 20 receives the photon in a time unit is increased by one when the receiver 20 receives the photon in a certain time unit, so as to obtain the number of times that the receiver 20 receives the photon in each time unit after the light pulse is transmitted for multiple times.

Referring to fig. 4 and 8, in particular, the distance measuring system 100 starts timing when the light pulse is emitted toward the object 50, and records the time when the photon in the light pulse reflected by the object 50 is detected, so as to obtain the flight time τ that the single photon travels from the emitter 10 to the object 50 and then reflected by the object 50 to the receiver 20. Since the speed of light C is known, it can be passed

The distance S between the ranging system 100 and the object 50 is calculated. The time of flight τ can be specifically obtained by TCSPC techniques. A histogram can be built of time and the number of times the receiver 20 receives a photon (count of counts of photon signals) according to TCSPC techniques. The histogram is an integration of distribution functions of photons with time in a plurality of preset periods, and can reflect a distribution relation of the number of times of receiving photons by the receiver 20 with time after one or more times of transmitting light beams.

The time taken by the histogram statistics for one predetermined period, i.e. one cycle as shown in b of fig. 8, depends on the range of the range to be measured, e.g. the distance between the range system 100 and the object 50 to be measured is 10m, and considering the speed of light, the time taken by one photon to go back and forth from the emission to the reflection back to the receiver 20 is the time required for the light to go 20m, which is about 67ns, so if the range of the range system 100 is 10m, the time of one predetermined period of the histogram statistics must be greater than 67 ns. Considering the current demand of consumer electronics, a predetermined period of time of the histogram statistic is at least 40 ns. In an embodiment of the present application, the preset period is in a range of [40ns, 100ns ]. If the predetermined period is less than 40ns, the photons may not be counted, and the ranging accuracy is reduced. If the preset period is greater than 100ns, the time for one-time statistics may be longer, which results in lower statistical efficiency, increased ranging duration, and lower ranging sensitivity. Therefore, the value range of the preset period is [40ns, 100ns ], photons can be counted, the ranging precision is guaranteed, and the ranging duration can be shortened.

In order to determine the time of flight τ of the detected photons, the predetermined period is divided into a separate series of time units. Referring to fig. 8, the time interval between the two dotted lines shown in the diagrams b and c in fig. 8 is a time unit. In each preset period (each cycle), typically no more than one photon is detected. The time-to-digital converter 41 counts the number of photon counts per preset period (each cycle), i.e. counts the number of photons received by the receiver 20. In a preset period, if a photon is detected, the count value of the photon in the corresponding time unit is increased by 1 in the preset period, which is equivalent to the increase of the number of recording photons by 1. If no photon is detected in a preset period, the count value of the photon in the corresponding time unit is increased by 0, which is equivalent to the increase of the number of the recording photon by 0. Through accumulation of the number of times of light pulse emission and accumulation of the number of times of photon reception for a plurality of preset periods, the time-to-digital converter 41 can finally establish waveform information shown in a c diagram in fig. 10 in the form of a histogram to acquire the time of flight τ. In the embodiment of the present application, the time unit has a value range of [50ps, 400ps ]. If the time unit is less than 50ps, it is difficult to implement in circuit design. If the time unit is greater than 400ps, the accuracy and precision of the time-of-flight τ for subsequent processing of the histogram acquisition may be reduced. Therefore, the value range of the time unit is [50ps, 400ps ], the realization of circuit design can be met, and the accuracy and precision of the flight time tau acquired by subsequent processing of the histogram can be improved.

Referring to fig. 9, in some embodiments, the method for controlling the electronic device 1000 further includes:

06: outputting a histogram according to the number of times of receiving photons by the receiver 20 in each time unit;

07: post-processing the histogram to obtain a peak time corresponding to the highest peak of the histogram;

08: acquiring the flight time of the optical pulse according to the peak time and the initial time of transmitting the optical pulse; and

09: and acquiring distance information according to the flight time and the light speed.

Referring again to fig. 2, in some embodiments, the processor 43 is further configured to perform the methods of 06, 07, 08, and 09. That is, the processor 43 is further configured to output a histogram according to the number of times the receiver 20 receives photons in each time unit; post-processing the histogram to obtain a peak time corresponding to the highest peak of the histogram; acquiring the flight time of the optical pulse according to the peak time and the initial time of transmitting the optical pulse; and obtaining distance information according to the flight time and the light speed.

Referring to fig. 10, fig. 10 shows a histogram over time and the number of times a photon is received by receiver 20. Specifically, assuming that each time unit is 1ns, the second threshold value may be preset to be 15. Referring to fig. 10 (a), after the 1 st light pulse is emitted from the emitter 10, the receiver 20 does not detect a photon, and therefore, the count value is not incremented for any time unit, or the count values are considered to be +0 for all time units. Referring to fig. 10 (b), after the 2 nd light pulse is emitted from the emitter 10, the receiver 20 still does not detect a photon, and therefore, the count value is not incremented for any time unit, or the count values are still considered to be +0 for all time units. Referring to fig. 10 (c), after the 3 rd to 5 th light pulses are emitted from the emitter 10, the receiver 20 does not detect a photon, and after the 6 th light pulse is emitted from the emitter 10, the receiver 20 detects a photon in the time unit at the 6ns, so that the time unit count value at the 6ns is +1, and only one time unit on the whole histogram has a count value. Referring to fig. 10 (d), after the 7 th to 10 th light pulses are emitted from the emitter 10, the receiver 20 does not detect a photon, until after the 11 th light pulse is emitted from the emitter 10, the receiver 20 detects a photon in the time unit at 8ns, so that the time unit count value at 8ns is +1, and two time units have count values in the whole histogram. Referring to fig. 10 (e), after the 30 th time of light pulse transmission by the transmitter 10, the receiver 20 detects photons in more time units, and counts a value of +1 at the corresponding time unit each time a photon is detected. Referring to fig. 10 (f), after the transmitter 10 transmits the light pulse for the 100 th time, the receiver 20 detects the photon in more time units, and counts a value +1 at the corresponding time unit each time the receiver 20 detects the photon. At this time, it can be seen that a plurality of count values are accumulated at several time unit positions. Referring to fig. 10 (g), after the transmitter 10 transmits the light pulse for the 300 th time, the receiver 20 detects the photon in more time units, and counts a value of +1 at the corresponding time unit each time the receiver 20 detects the photon. At this time, it can be seen that the count value accumulated in the time unit with the largest count value has reached 15, i.e. the number of times the recording receiver 20 receives photons reaches the second threshold value, so that the controller 30 controls the transmitter 10 to stop transmitting light pulses and sends a signal to the time-dependent photon counting system 40 to stop the loop counting by the time-dependent photon counting system 40. Referring to fig. 10 (h), after stopping the statistics, the obtained histogram may be post-processed to calculate the distance S from the ranging system 100 to the object 50.

Referring to fig. 11 and 12, there may be one or more time cells in the histogram having a count value greater than 0. Processor 43 may perform smooth filtering on the count values of the respective time units in the histogram to obtain waveform information about the time-varying count values. The time unit in which the highest peak value is located can be reflected in a plurality of preset periods, and the number of times of detecting photons in the time unit is the largest. Therefore, the peak time corresponding to the highest peak of the histogram can more accurately reflect the time when the receiver 20 receives the photon. The processor 43 is able to obtain the time of flight τ of the light pulse according to the peak time and the start time of the detection period, and then pass the light pulse according to the time of flight τ and the speed of light C

The distance S between the ranging system 100 and the object 50 is calculated.

Referring to fig. 9 again, in some embodiments, the method for controlling the electronic device 1000 may further include:

010: and when the number of times of emission of the optical pulses reaches a first threshold and the number of times of receiving the photon signal by the receiver 20 in the time unit is less than a second threshold, controlling the emitter 10 to stop emitting the optical pulses.

Referring again to fig. 2, in some embodiments, the controller 30 is further configured to control the transmitter 10 to stop transmitting the light pulse when the number of times of light pulse transmission reaches the first threshold and the number of times of receiving the photon signal by the receiver 20 in the time unit is less than the second threshold.

Referring to fig. 13, in order to make the distance measurement accurate, it is often necessary to transmit light pulses multiple times to perform the distance measurement to accumulate information of multiple preset periods to build a histogram. The more the number of times the light pulse is emitted, the closer the ranging result is to the actual distance. However, in view of ranging efficiency, too many measurements may result in an increase in the time for the user to wait for ranging. Therefore, a preset first threshold value may be calibrated according to a plurality of tests, the emission of the light pulse may be stopped when the number of times that the emitter 10 emits the light pulse reaches the preset first threshold value, and the histogram may be processed to obtain the distance information of the object, and the distance information obtained at this time may be considered to have higher accuracy and precision. If the emitter 10 continues to emit light beams after the number of times of emitting light pulses reaches the preset first threshold and counts photons, although the accuracy and precision of the ranging result can be improved to some extent, the degree of improvement is very low, and the ranging efficiency is low, and the power consumption of the ranging system 100 is increased.

Referring to fig. 13, fig. 13 shows the results obtained by processing after the distance measuring system 100 emits light pulses with the same intensity and the number of times of emitting light pulses of the emitter 10 reaches 3000 times and 300 times when the distance measuring system is 1m and 9m away from the measured object 50, respectively, wherein the preset first threshold is 3000 times. When the distance from the measured object 50 is 1m, the count value of the highest peak value (the number of times that the receiver 20 receives photons) after the number of times that the emitter 10 emits the light pulse reaches 3000 times is 120, the obtained distance is 1.0187m, the relative error of 100 repeated measurements is 0.24163%, and the relative error is less than 0.5%, which meets the practical index. The count value of the highest peak value (the number of times that the receiver 20 receives photons) after the number of times that the transmitter 10 transmits the light pulse reaches 300 times is 12, the obtained distance is 1.0204m, the relative error of 100 repeated measurements is 0.038661%, and the relative error is less than 0.5%, which meets the practical index. Therefore, when the distance to the measured object 50 is 1m, the transmitter 10 can transmit the light pulse 3000 times and 300 times to obtain more accurate distance measurement, that is, more accurate distance measurement can be obtained when the count value is 120 and the count value is 12. This is because, when the distance between the light pulses with the same emission intensity is measured, the closer the light pulse is to the object 50 to be measured, the stronger the reflected signal is, and the higher the probability that the receiver 20 receives the photon is, so that the reflected signal can be measured according to the count value of the photon, and the larger the count value of the photon is, that is, the larger the number of recorded photons is, the stronger the reflected signal is, so as to ensure that the distance measurement is accurate and reduce the emission times of the light pulses emitted by the emitter 10 when the reflected signal is stronger.

Referring to fig. 14, in some embodiments, the method for controlling the electronic device 1000 further includes:

042: before each time the emitter 10 emits a light pulse, it is compared whether the number of times each time unit receives a photon in the previous emission period is greater than a preset second threshold value, and whether the number of times the light pulse is emitted is less than a first threshold value.

Referring again to fig. 2, in some embodiments, the comparator 42 is further configured to compare whether the number of times that each time unit receives a photon in the previous emission period is greater than a second predetermined threshold before each emitter emits a light pulse, and whether the number of times that the light pulse is emitted is less than the first predetermined threshold.

In the embodiment of the present application, a preset second threshold may be calibrated according to multiple tests, and when the number of times of light pulse emission is smaller than the preset first threshold and the number of times of receiving photons by the recording detector 20 in any time unit is greater than the preset second threshold, the light pulse emission is stopped, and the histogram is processed to obtain the distance information of the object, and it can be considered that the distance information of the object obtained at this time has higher accuracy and precision. Therefore, the frequency of emitting light pulses can be reduced, the power consumption of the ranging system 100 is saved, the time for a user to wait for ranging is reduced, the ranging time is shortened, and the ranging sensitivity is improved. The value range of the second threshold is related to the photoelectric conversion efficiency of the SPAD, the preset period length of the histogram and the size of each time unit. The higher the photoelectric conversion efficiency of the SPAD, the higher the sensitivity of the receiver 20, and the easier it is to detect photons, so a smaller second threshold value can be set. The longer the preset period length of the histogram is, the more easily photons are detected the farther the distance measuring system 100 is from the measured object 50, so that a larger second threshold value can be set. The finer the division of each time unit, the easier it is to count the count value of photons, so a smaller second threshold value can be set.

Referring to fig. 13 again, when the distance from the object to be measured 50 is 9m, the count value of the peak value after the number of times of light pulse transmission by the transmitter 10 reaches 3000 times is 1.6, the obtained distance is 8.6939m, and the relative error is 0.30139% after 100 times of repeated measurement, and the relative error is less than 0.5%, which meets the practical index. The count value of the highest peak value after the number of times of transmitting the light pulse by the transmitter 10 reaches 300 times is 0.4, the obtained distance is 3.7948m, the relative error of 100 times of repeated measurement is 2.8316%, the relative error is more than 0.5%, and the practical index is not met. In this regard, the range accuracy obtained when the number of times the transmitter 10 transmits the light pulse reaches 300 times is poor at a distance of 9m from the measured object 50. This is because, in the optical pulse ranging with the same emission intensity, the farther the distance from the object 50 to be measured is, the worse the reflected signal is, the smaller the probability of counting photons is, and therefore, the higher accuracy ranging result can be obtained only by satisfying a certain number of times of optical pulse emission. In the embodiment of the present application, the count value in any time unit may be smaller than a preset second threshold, that is, the number of photons is smaller than the second threshold, and the number of times that the emitter 10 emits the optical pulse reaches a preset first threshold, the emission of the optical pulse is stopped, and the histogram is processed to obtain the distance information. And if the count value of any time unit is smaller than the preset second threshold, the reflected signal is poor. Thus, the measurement can be continued for a plurality of times in an environment with a poor reflected signal, the emission of the light pulse can be stopped until the number of times of emitting the light pulse by the emitter 10 reaches a preset first threshold, and the histogram is processed to obtain the distance information of the object, and the distance information of the object obtained at this time can be considered to have higher accuracy and precision.

Fig. 13 illustrates only the ranging situation after the transmitter 10 transmits the light pulse 3000 times and 300 times when the ranging system is respectively 1m and 9m away from the measured object, the distance to be measured of the control method in the embodiment of the present invention is not limited to 1m and 9m, and the control method in the embodiment of the present invention can achieve a good ranging effect in the range of the ranging distance [0.2m, 10m ] in consideration of the power of the transmitter 10 and the ranging range of the conventional electronic device 1000, for example, the ranging distance may be 0.2m, 0.5m, 1.5m, 2.2m, 3.7m, 4.8m, 5.0m, 6.3m, 7.1m, 8.2m, 9.6m, 10.0m, and the like, and is not limited herein. The control method of the electronic device is further suitable for ranging of the laser radar, and when the control method is applied to ranging of the laser radar, the distance to be measured can be extended to 200m or even farther. For example, when the laser radar performs ranging, the preset first threshold can ensure that the laser radar can still obtain a relatively accurate calculation result when the distance from the laser radar to the measured object 50 is 1000m, and then when the laser radar performs ranging at a distance of 200m from the measured object 50, a situation that a count value on any time unit is greater than a preset second threshold, that is, the number of photons is greater than the second threshold, and the number of times of light pulse emission is less than the preset first threshold may occur.

Referring to fig. 15, in some embodiments, after ranging begins, a pulse of light is transmitted toward the object 50 to be measured, and a count of one transmission cycle begins. When a photon signal is detected, the count value is increased by 1 at the corresponding time unit. The following determinations were then made:

when the number of times of transmitting the light pulse by the transmitter 10 is smaller than the first threshold value and the count value of any time unit of the histogram is smaller than the second threshold value, the light pulse is continuously transmitted, and the histogram statistics of the next period is performed.

When the number of times the transmitter 10 transmits the light pulse is less than the first threshold value and the count value of any time unit of the histogram is equal to or greater than the second threshold value, the transmission of the light pulse is stopped, and the histogram is processed to acquire the distance information of the object.

When the number of times of emission of the light pulse by the emitter 10 is equal to or greater than the first threshold value and the count value of any time unit of the histogram is smaller than the second threshold value, the emission of the light pulse is stopped, and the histogram is processed to acquire the distance information of the object.

In fact, according to the flow shown in fig. 15, when the number of times the transmitter 10 transmits the light pulse is equal to the first threshold, the transmission of the light pulse is stopped regardless of whether the count value of any time unit of the histogram is smaller than the second threshold, and the histogram is processed to acquire the distance information. The flow shown in fig. 15 may be modified to the flow shown in fig. 16 as needed. The flow shown in fig. 16 differs from the flow shown in fig. 15 in that, in the flow shown in fig. 16, when the count value of any time unit of the histogram is equal to or greater than the second threshold, whether or not the number of times the transmitter 10 transmits the light pulse reaches the first threshold, the transmission of the light pulse is stopped, and the histogram is processed to acquire the distance information. Thus, the embodiment of the application can obtain the distance information of the object with higher accuracy and precision by counting the preset histogram with the number of times equal to the first threshold, and when the count value of any time unit meeting the histogram is equal to or greater than the second threshold, that is, when the reflected signal is better and photon number is easy to count, the emission of the optical pulse is stopped in advance, so as to reduce the number of times of optical pulse emission required by ranging, reduce the power consumption of the ranging system 100, reduce the time for a user to wait for ranging, shorten the ranging time, and improve the ranging sensitivity.

Referring to fig. 17 in combination with fig. 2 and 6, an embodiment of the present disclosure further provides an electronic device 1000 and another control method applied to the electronic device 1000. The control method of the electronic device 1000 includes:

011: emitting a light pulse;

012: detecting photons in the optical pulse reflected back by the object in a preset detection period and forming a photon signal, wherein the detection period comprises a plurality of time units;

013: counting at time units corresponding to the detection period when the photon signal is formed;

014: counting the count of the photon signals in each detection period once, thereby counting the counts of the photon signals in a plurality of detection periods a plurality of times to output a histogram of count values with respect to time and the counts of the photon signals;

015: when the counting times are smaller than a preset first threshold value and the counting value on any time unit is larger than a preset second threshold value, stopping transmitting the light pulse; and

016: the histogram is processed to obtain distance information.

Referring to fig. 2, an electronic device 1000 according to an embodiment of the present disclosure includes a distance measuring system 100. Ranging system 100 includes a transmitter 10, a receiver 20, a controller 30, and a time-dependent photon counting system 40. The time-dependent photon counting system 40 includes a time-to-digital converter 41, a comparator 42, and a processor 43. The transmitter 10 may be used to perform the method in 011. The receiver 20 may be used to perform the method in 012. The time-dependent photon counting system 40 can be used to perform the methods of 013, 014, and 016. The controller 30 may be used to perform the method of 015. I.e. the transmitter 10 is used to transmit light pulses. The receiver 20 is operable to detect photons in the light pulses reflected back by the object and form a photon signal during a predetermined detection period, the detection period comprising a plurality of time cells. The time-dependent photon counting system 40 is operable to count over a time unit corresponding to the detection period when the photon signal is formed; counting the count of the photon signals in each detection period once, thereby counting the counts of the photon signals in a plurality of detection periods a plurality of times to output a histogram of count values with respect to time and the counts of the photon signals; and processing the histogram to obtain distance information. The controller 30 may be configured to stop transmitting the light pulse when the counted number is smaller than a preset first threshold and the count value in any time unit is larger than a preset second threshold.

The electronic device 1000 may be, but is not limited to, a mobile phone, a tablet computer, a notebook computer, a smart watch, a game machine, a head display device, a laser ruler, etc., and among these electronic devices, the distance measuring system 100 is often provided to achieve the distance measuring function. Specifically, the distance measuring system may be a dTOF distance measuring system, and the dTOF distance measuring system may establish a distribution function of photons over time by a time-dependent photon counting technique, that is, establish a histogram of count values with respect to time and counts of photon signals, and then obtain distance information of the object by performing data processing on the histogram.

Referring to fig. 3, when it is required to measure the distance between the electronic device 1000 and the object 50, a light pulse is emitted from the emitter 10 to the object 50. The receiver 20 detects photons in the light pulse reflected by the object 50 in a preset detection period and forms a photon signal, and the controller 30 performs a count of the photon signal in each detection period, thereby performing a plurality of counts of the photon signals in a plurality of detection periods to output a histogram of count values with respect to time and the count of the photon signals, and processes the histogram to acquire distance information. In this process, the distance measuring system 100 needs to perform statistics several times after emitting the light pulse. In the ranging process, a first threshold is often set according to the distance between the electronic device 1000 and the object 50, and when the number of times of light pulse emission or the number of times of statistics exceeds the first threshold, it can be considered that the statistical result has sufficient accuracy, that is, the controller 30 can obtain more accurate distance information through the histogram output after statistics of the number of times of statistics equal to the first threshold.

The embodiment of the present application provides the comparator 42 in the ranging system 100, and the comparator 42 can be used with the time-to-digital converter 41 to implement the following functions: counting at time units corresponding to the detection period when the photon signal is formed; and counting the photon signals in each detection period for one time, so as to stop transmitting the light pulses when the emission times or the counted times of the light pulses are smaller than a preset first threshold value and the count value of the receiver 20 in any time unit of the times of receiving the photon signals in any time unit is larger than a preset second threshold value, thereby saving energy. When the count value of the photon signal is greater than the preset second threshold, it indicates that the photon signal intensity is sufficient in the current ranging environment, and the photon signal intensity is relatively easy to detect, and this ranging environment is often a ranging environment closer to the object 50 to be measured. Thus, when the distance measurement is short, the actual counting times can be reduced on the basis of obtaining more accurate distance information, that is, the times of emitting light pulses are reduced to save laser energy, the power consumption of the distance measurement system 100 is reduced, and the time for measuring the distance is shortened.

Referring to FIG. 2, in some embodiments, the emitter 10 includes a vertical cavity surface emitting laser, an edge emitting semiconductor laser, and a light emitting diode. These light sources may be point light sources consisting of a single laser or diode, or may be array light sources consisting of a plurality of lasers or diodes. The transmitter 10 can transmit pulses of light at a frequency to the object 50 under the control of the pulse driver 33 for use in the measurement of dTOF ranging.

In some embodiments, the receiver 20 includes a photon avalanche diode, or an array of a plurality of SPADs, for detecting photons in the pulse reflected back by the object 50 and forming a photon signal. The SPAD is capable of responding to a single photon in the reflected pulse, and the single photon incident on the SPAD generates a very distinct avalanche signal, i.e. a photon signal. Every time the SPAD outputs a photon signal to the time-to-digital converter 41, the count value of the photon signal counted by the time-to-digital converter 41 is increased by 1.

Referring to fig. 18, in some embodiments, 014: counting the count of the photon signals in each detection period once, thereby counting the count of the photon signals in a plurality of detection periods a plurality of times to output a histogram of count values with respect to time and the count of the photon signals, comprising:

0141: in each detection period, if a photon signal is formed, adding one to the count value of the corresponding time unit;

0143: accumulating the respective count value of each time unit in each detection period; and

0145: and acquiring a histogram according to the total duration of each detection period and the respective count value of each time unit in each detection period.

Referring again to fig. 2, in some embodiments, the time-dependent photon counting system 40 is further configured to perform the methods of 0141, 0143, and 0145. That is, the time-dependent photon counting system 40 is further configured to, in each detection period, increment the count value of the corresponding time unit by one if a photon signal is formed; accumulating the respective count value of each time unit in each detection period; and acquiring a histogram according to the total duration of each detection period and the respective count value of each time unit in each detection period.

The distance S between the ranging system 100 and the object 50 is calculated. The time of flight τ can be specifically obtained by TCSPC techniques. A histogram of the count values with respect to time and count of photon signals may be established according to TCSPC techniques. The histogram is the integration of the distribution function of photons over time in a plurality of measurement periods, and can reflect the distribution relation of the counting value of the counting of photon signals over time after one or more measurement statistics.

The time taken by the histogram statistics for one detection period, i.e. one cycle as shown in b of fig. 8, depends on the range of the range to be measured, e.g. the distance between the range system 100 and the object 50 to be measured is 10m, and considering the speed of light, the time taken by one photon to go back and forth from the emission to the reflection back to the receiver 20 is the time taken by the light to go 20m, which is about 67ns, so if the range of the range system 100 is 10m, the time of one detection period of the histogram statistics must be greater than 67 ns. Considering the current requirements of consumer electronics, one detection cycle time of the histogram statistics is at least 40 ns. In the embodiment of the present application, the detection period has a value range of [40ns, 100ns ]. If the detection period is less than 40ns, the photons may not be counted, and the ranging accuracy is reduced. If the detection period is greater than 100ns, the time for one-time statistics may be longer, which results in lower statistical efficiency, increased ranging duration, and lower ranging sensitivity. Therefore, the value range of the detection period is [40ns, 100ns ], photons can be counted, the ranging precision is guaranteed, the ranging duration can be shortened, and the ranging sensitivity is improved.

In order to determine the time of flight τ of the detected photons, the detection period is also divided into a separate series of time units. Referring to fig. 8, the time interval between the two dotted lines shown in the diagrams b and c in fig. 8 is a time unit. In each measurement period (each cycle), typically no more than one photon is detected. The time-to-digital converter 41 performs count value statistics of one photon count for each measurement period (each cycle). If a photon is detected during a measurement period, the count of photons in the corresponding time unit is incremented by 1 in the statistics. If no photon is detected in a period, the count value of the photon in the corresponding time unit is increased by 0 in the statistics. After the accumulation of the statistical number of measurement cycles and the accumulation of the count value, the time-to-digital converter 41 can finally create waveform information shown in a c diagram in fig. 10 in the form of a histogram to acquire the time of flight τ. In the embodiment of the present application, the time unit has a value range of [50ps, 400ps ]. If the time unit is less than 50ps, it is difficult to implement in circuit design. If the time unit is greater than 400ps, the accuracy and precision of the time-of-flight τ for subsequent processing of the histogram acquisition may be reduced. Therefore, the value range of the time unit is [50ps, 400ps ], the realization of circuit design can be met, and the accuracy and precision of the flight time tau acquired by subsequent processing of the histogram can be improved.

Referring to fig. 19, in some embodiments, 016: processing the histogram to obtain distance information of the object, comprising:

0161: post-processing the histogram to obtain a peak time corresponding to the highest peak of the histogram;

0163: acquiring the flight time of the optical pulse according to the peak time and the initial time of the detection period; and

0165: and obtaining the distance information of the object according to the flight time and the light speed corresponding to the peak value of the histogram.

Referring again to FIG. 2, in some embodiments, processor 43 is also configured to perform the methods of 0161, 0163, and 0165. That is, the processor 43 is further configured to perform post-processing on the histogram, and obtain a peak time corresponding to a highest peak of the histogram; acquiring the flight time of the optical pulse according to the peak time and the initial time of the detection period; and acquiring the distance information of the object according to the flight time and the light speed corresponding to the peak value of the histogram.

Referring to fig. 20, fig. 20 illustrates a process of counting in time units, obtaining a histogram according to the results of counting and counting, and post-processing the histogram to calculate a distance. As shown in fig. 20, each time unit is 1ns, and the second threshold value may be preset to be 15. Referring to fig. 20 (a), no photon is detected in the first statistic, so that no time unit is counted up, or all time units are considered to have a count value of + 0. Referring to fig. 10 (b), no photon is detected in the second statistic, and therefore no time unit is incremented. Referring to fig. 20 (c), in the 3 rd to 5 th statistics, no photon is detected until the 6 th statistics, and therefore, the time unit count value at the 6ns is +1, and only one time unit has a count value in the entire histogram. Referring to fig. 20 (d), in the 7 th to 10 th statistics, no photon is detected, until the 11 th statistics, a photon is detected in the time unit at 8ns, so that the time unit count value at 8ns is +1, and there are two time units count values on the whole histogram. Referring to fig. 20 (e), after 30 times of statistics, photons are detected in more time units, and each time a photon is detected, the value is counted at the corresponding time unit as + 1. Referring to fig. 20 (f), after performing statistics 100 times, photons are detected in more time units, and each time a photon is detected, the value is counted at the corresponding time unit as + 1. At this time, it can be seen that a plurality of count values are accumulated at several time unit positions. Referring to fig. 20 (g), after 300 times of statistics, photons are detected in more time units, and each time a photon is detected, the value is counted at the corresponding time unit as + 1. At this point it can be seen that the count value accumulated over the time unit with the largest count value has reached 15, i.e. the second threshold value is reached, whereupon the controller 30 controls the emitter 10 to stop emitting light pulses and sends a signal to the time-dependent photon counting system 40 to stop the cycle counting by the time-dependent photon counting system 40. Referring to fig. 20 (h), after stopping the statistics, the obtained histogram may be post-processed to calculate the distance S between the ranging system 100 and the object 50.

Referring to fig. 11 and 12, there may be one or more time cells in the histogram having a count value greater than 0. Processor 43 may perform smooth filtering on the count values of the respective time units in the histogram to obtain waveform information about the time-varying count values. The time unit in which the highest peak is located can be reflected in a plurality of measurement periods, and the number of times of detecting the photon in the time unit is the largest. Therefore, the peak time corresponding to the highest peak of the histogram can more accurately reflect the time when the receiver 20 receives the photon. The processor 43 is able to obtain the time of flight τ of the light pulse according to the peak time and the start time of the detection period, and then pass the light pulse according to the time of flight τ and the speed of light C

The distance S between the ranging system 100 and the object 50 is calculated.

Referring to fig. 21, in some embodiments, the method for controlling the electronic device 1000 further includes:

017: and when the counting value on any time unit is smaller than a preset second threshold and the counting times reach a preset first threshold, stopping transmitting the light pulse, and processing the histogram to acquire the distance information of the object.

Referring again to FIG. 2, in some embodiments, the time-to-digital converter 41 and the comparator 42 are also used to perform the method of 017. That is, the time-to-digital converter 41 and the comparator 42 are further configured to stop transmitting the light pulse when the counted number of times in any time unit is smaller than the preset second threshold and reaches the preset first threshold, and process the histogram to obtain the distance information of the object.

Referring to fig. 22, in order to make the ranging accurate, it is often necessary to transmit light pulses multiple times for ranging to accumulate information of multiple measurement periods to build a histogram. The higher the number of statistics of the histogram, the closer the ranging result is to the actual distance. However, in view of ranging efficiency, too many measurements may result in an increase in the time for the user to wait for ranging. Therefore, a preset first threshold value can be calibrated according to a plurality of tests, the emission of the light pulse can be stopped when the statistical times of the histogram reach the preset first threshold value, the histogram is processed to obtain the distance information of the object, and the distance information obtained at the moment can be considered to have higher accuracy and precision. If the light beam is continuously emitted after the number of times of statistics of the histogram reaches the preset first threshold and the statistics of photon counting is performed, although the accuracy and precision of the ranging result can be improved to a certain extent, the improved extent is very low, the ranging efficiency is low, and the power consumption of the ranging system 100 is increased.

Referring to fig. 22, fig. 22 shows the result of processing after 3000 times and 300 times of histogram statistics when the distance measuring system 100 emits light pulses with the same intensity at 1m and 9m from the measured object 50, respectively, wherein the preset first threshold is 3000 times. When the distance from the measured object 50 is 1m, the counting value of the highest peak value after 3000 times of histogram statistics is 120, the obtained distance is 1.0187m, the relative error of 100 times of repeated measurement is 0.24163%, the relative error is less than 0.5%, and the practical index is met. The counting value of the highest peak value after the histogram statistics for 300 times is 12, the obtained distance is 1.0204m, the relative error of 100 repeated measurements is 0.038661%, the relative error is less than 0.5%, and the practical index is met. Therefore, when the distance from the measured object 50 is 1m, more accurate ranging distances can be obtained by performing histogram statistics 3000 times and 300 times, that is, more accurate ranging distances can be obtained both when the count value is 102 and when the count value is 12. This is because, when the optical pulse with the same emission intensity is used for ranging, the closer the optical pulse is to the measured object 50, the stronger the reflected signal is, the higher the probability of counting photons is, so that the reflected signal can be measured according to the count value of the photons, and the larger the count value of the photons is, the stronger the reflected signal is, so as to reduce the number of times of counting while ensuring accurate ranging when the reflected signal is stronger. In the embodiment of the application, a preset second threshold value can be calibrated according to a plurality of tests, when the number of times of statistics is smaller than the preset first threshold value and the count value in any time unit is larger than the preset second threshold value, the emission of the light pulse is stopped, the histogram is processed to obtain the distance information of the object, and the distance information of the object obtained at the time can be considered to have higher accuracy and precision. Therefore, the frequency of emitting light pulses can be reduced, the power consumption of the ranging system 100 is saved, the time for a user to wait for ranging is reduced, the ranging time is shortened, and the ranging sensitivity is improved. The value range of the second threshold is related to the photoelectric conversion efficiency of the SPAD, the measurement period length of the histogram and the size of each time unit. The higher the photoelectric conversion efficiency of the SPAD, the higher the sensitivity of the receiver 20, and the easier it is to detect photons, so a smaller second threshold value can be set. The longer the measurement period length of the histogram is, the less easily photons are detected the further the distance measurement system is from the object 50 to be measured, and therefore, a larger second threshold value can be set. The finer the division of each time unit, the easier it is to count the count value of photons, so a smaller second threshold value can be set.

Referring to fig. 22, when the distance to the measured object 50 is 9m, the counted value of the highest peak value after 3000 times of histogram statistics is 1.6, the obtained distance is 8.6939m, and the relative error after 100 times of repeated measurements is 0.30139%, and the relative error is less than 0.5%, which meets the practical index. The counting value of the highest peak value after the histogram statistics for 300 times is 0.4, the obtained distance is 3.7948m, the relative error of 100 repeated measurements is 2.8316%, the relative error is more than 0.5%, and the practical index is not met. From this, when the distance from the measured object 50 is 9m, the distance obtained by performing the histogram statistics 300 times is poor in accuracy. This is because the farther the light pulse with the same emission intensity is from the measured object 50, the worse the reflected signal is, the smaller the probability of counting photons is, and therefore, the higher accuracy of the ranging result can be obtained only by satisfying a certain number of times of counting. In the embodiment of the application, the counting value in any time unit may be smaller than the preset second threshold, and the counting number reaches the preset first threshold, the emission of the light pulse is stopped, and the histogram is processed to obtain the distance information. Wherein, the count value of any time unit being less than the preset second threshold value indicates that the reflected signal is poor. Therefore, multiple measurements can be continuously performed in an environment with poor reflected signals, the emission of the light pulse can be stopped until the statistical times of the histogram reach a preset first threshold, the histogram is processed to obtain the distance information of the object, and the distance information of the object obtained at the time can be considered to have higher accuracy and precision.

Fig. 22 illustrates only the ranging situations after 3000 times and 300 times of histogram statistics when the ranging system is respectively measured to 1m and 9m, the distance to be measured of the control method in the embodiment of the present invention is not limited to 1m and 9m, and the control method in the embodiment of the present invention can achieve a good ranging effect in the range of the ranging distance [0.2m, 10m ] in consideration of the power of the transmitter 10 and the ranging range of the conventional electronic device 1000, for example, the ranging distance may be 0.2m, 0.5m, 1.5m, 2.2m, 3.7m, 4.8m, 5.0m, 6.3m, 7.1m, 8.2m, 9.6m, 10.0m, and the like, which is not limited herein. The control method of the embodiment of the application is also suitable for ranging of the laser radar, and when the control method of the embodiment of the application is applied to ranging of the laser radar, the distance to be measured can be expanded to 200m or even be farther. For example, when the laser radar measures the distance, the preset first threshold value can ensure that the laser radar can still obtain a relatively accurate calculation result when the distance from the laser radar to the measured object 50 is 1000m, then when the laser radar measures the distance from the measured object 50 to the measured object by 200m, the situation that the count value on any time unit is greater than the preset second threshold value and the counting frequency is less than the preset first threshold value may occur, at this time, the laser pulse transmission can be stopped in advance according to the control method of the embodiment of the present application, and the histogram is processed to obtain the distance information of the object, so as to reduce the pulse transmission frequency required by distance measurement, reduce the power consumption of the distance measurement system, reduce the time for the user to wait for distance measurement, shorten the distance measurement time length, and improve the distance.

Referring to fig. 23, in some embodiments, after ranging begins, a pulse of light is emitted toward the object under test 50, while statistics for one measurement cycle begin to be timed. When a photon signal is detected, the count value is increased by 1 at the corresponding time unit. The following determinations were then made:

and when the histogram statistic times are smaller than a first threshold value and the count value of any time unit of the histogram is smaller than a second threshold value, continuing to emit the light pulse, and carrying out the histogram statistic of the next period.

And when the statistical times of the histogram are less than a first threshold value and the count value of any time unit of the histogram is equal to or greater than a second threshold value, stopping transmitting the light pulse, and processing the histogram to acquire the distance information of the object.

And when the statistical times of the histogram are equal to or larger than a first threshold value and the count value of any time unit of the histogram is smaller than a second threshold value, stopping transmitting the light pulse, and processing the histogram to acquire the distance information of the object.

In fact, according to the flow shown in fig. 23, when the histogram statistic count is equal to the first threshold, the emission of the light pulse is stopped regardless of whether the count value of any time unit of the histogram is smaller than the second threshold, and the histogram is processed to acquire the distance information. The flow shown in fig. 23 may be adjusted to the flow shown in fig. 24 as needed. The flow shown in fig. 24 differs from the flow shown in fig. 23 in that, in the flow shown in fig. 24, when the count value of any time unit of the histogram is equal to or greater than the second threshold, the emission of the light pulse is stopped regardless of whether the histogram statistics number reaches the first threshold, and the histogram is processed to acquire the distance information. Therefore, the embodiment of the application can acquire the distance information of the object with higher accuracy and precision by counting the preset histogram with the number of times equal to the first threshold, and when the count value of any time unit of the histogram is equal to or greater than the second threshold, namely when the reflected signal is better and photon count value is easy to count, the emission of the light pulse is stopped in advance, so that the number of times of light pulse emission required by ranging is reduced, the power consumption of the ranging system 100 is reduced, the time for a user to wait for ranging is reduced, the ranging time is shortened, and the ranging sensitivity is improved.

Referring to fig. 25, the present application further provides a non-volatile computer-readable storage medium 400 containing a computer program 401. The computer program 401, when executed by the one or more processors 43, causes the processors 43 to perform the control method of any of the embodiments described above.

Referring to fig. 1, for example, the computer program 401, when executed by the one or more processors 43, causes the processor 80 to perform the following control method:

01: emitting a light pulse toward the target object 50;

02: receiving photons;

03: recording the time of arrival of the photon at the receiver 20;

04: recording the photon receiving times of the receiver 20 in each time unit, and comparing whether the photon receiving times of each time unit in the previous emission period are greater than a preset second threshold before each emission of the light pulse; and

As another example, the computer program 401, when executed by the one or more processors 43, causes the processors 43 to perform the following control method:

011: emitting a light pulse;

014: counting the count of the photon signals in each detection period once, thereby counting the counts of the photon signals in a plurality of detection periods a plurality of times to output a histogram of count values with respect to time and the count of the photon signals, and comparing whether the count value in each time unit in the previous detection period is greater than a preset second threshold before each emission of the light pulse;

016: the histogram is processed to obtain distance information.

In the description herein, references to the description of the terms "certain embodiments," "one example," "exemplary," etc., mean 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. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one 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 changes, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present application.

Claims

1. An electronic device, comprising:

a transmitter for transmitting light pulses to a target object;

a receiver for receiving photons;

a time-to-digital converter for recording the time of arrival of the photon at the receiver;

a comparator for recording the number of times the receiver receives photons in each time unit; and

and the controller is used for controlling the emitter to stop emitting the light pulses when the emission times of the light pulses are smaller than a preset first threshold and the number of times of receiving photons by the receiver in any time unit is larger than a preset second threshold.

2. The electronic device of claim 1, wherein the time-to-digital converter is further configured to:

and recording the times of receiving the photons by the receiver in each time unit once every time the optical pulse is transmitted, wherein when the receiver does not receive the photons, the times of receiving the photons by the receiver in each time unit are recorded as zero, and when the receiver receives the photons in a certain time unit, the times of receiving the photons by the receiver in the time unit are increased by one, so that the times of receiving the photons by the receiver in each time unit after the optical pulse is transmitted for multiple times are obtained.

3. The electronic device of claim 1, further comprising one or more processors configured to:

outputting a histogram according to the times of receiving photons by the receiver in each time unit;

post-processing the histogram to obtain a peak time corresponding to the highest peak of the histogram;

acquiring the flight time of the optical pulse according to the peak time and the starting time of transmitting the optical pulse; and

and acquiring the distance information according to the flight time and the light speed.

4. The electronic device of claim 1, wherein the controller is further configured to:

and when the number of times of emission of the light pulses reaches the first threshold and the number of times of receiving photon signals by the receiver in the time unit is smaller than the second threshold, controlling the emitter to stop emitting the light pulses.

5. The electronic device of claim 1, wherein the transmitter transmits the light pulses to the target object at a predetermined period, wherein the predetermined period is in a range of [40ns, 100ns ], and wherein the time unit is in a range of [50ps, 400ps ].

6. The electronic device of claim 1, wherein the comparator is further configured to:

comparing whether the number of times each time unit receives the photon in the previous emission period is greater than the preset second threshold value before each time the emitter emits the light pulse, and comparing whether the number of times the light pulse is emitted is less than the first threshold value.

7. The electronic device of claim 6, wherein the comparator is disposed within the time-to-digital converter; or the comparator is provided independently of the time-to-digital converter.

8. An electronic device comprising an emitter, a receiver, a time-dependent photon counting system, and a controller, the emitter configured to: emitting a light pulse;

the receiver is configured to:

detecting photons in the optical pulses reflected back by an object within a preset detection period and forming photon signals, wherein the detection period comprises a plurality of time units;

the time-dependent photon counting system is configured to:

counting over time units corresponding to the detection periods when the photon signals are formed;

counting the count of the photon signals in each of the detection periods once, thereby counting the count of the photon signals in a plurality of the detection periods a plurality of times to output a histogram of count values with respect to time and the count of the photon signals; and

processing the histogram to obtain distance information;

the controller is configured to:

and when the counting times are less than a preset first threshold value and the counting value on any one time unit is greater than a preset second threshold value, stopping transmitting the light pulse.

9. The electronic device of claim 8, wherein the controller is further configured to:

and when the count value on any one time unit is smaller than a preset second threshold value and the counting times reach a preset first threshold value, stopping transmitting the light pulse.

10. The electronic device of claim 8, wherein the time-dependent photon counting system is further configured to:

in each detection period, if the photon signal is formed, adding one to the count value of the corresponding time unit;

accumulating the respective count value of each time unit in each detection period; and

and acquiring the histogram according to the total duration of each detection period and the respective count value of each time unit in each detection period.

11. The electronic device of claim 8, wherein the time-dependent photon counting system is further configured to:

acquiring the flight time of the optical pulse according to the peak time and the initial time of the detection period; and

12. The electronic device of claim 8, wherein the detection period is in a range of [40ns, 100ns ], and the time unit is in a range of [50ps, 400ps ].

13. A method of controlling an electronic device, comprising:

emitting light pulses towards the target object;

receiving photons;

recording the time of arrival of said photon at said receiver;

recording the number of times the receiver receives photons in each time unit; and

and when the emission times of the optical pulses are smaller than a preset first threshold and the times of receiving photon signals by the receiver in the time unit are larger than a preset second threshold, controlling the emitter to stop emitting the optical pulses.

14. The method of claim 13, wherein said recording the number of times photons are received by said receiver in each time unit comprises:

15. The control method according to claim 14, characterized by further comprising:

16. The control method according to claim 13, characterized by further comprising:

17. The control method of claim 13, wherein said transmitting the light pulse to the target object comprises transmitting the light pulse to the target object at a preset period, the preset period having a value in a range of [40ns, 100ns ], and the time unit having a value in a range of [50ps, 400ps ].

18. The control method according to claim 13, characterized by further comprising:

19. A method of controlling an electronic device, comprising:

emitting a light pulse;

counting the count of the photon signals in each of the detection periods once, thereby counting the count of the photon signals in a plurality of the detection periods a plurality of times to output a histogram of count values with respect to time and the count of the photon signals;

when the counting times are smaller than a preset first threshold value and the counting value on any one time unit is larger than a preset second threshold value, stopping transmitting the light pulse; and

processing the histogram to obtain the distance information.

20. The control method according to claim 19, characterized by further comprising:

and when the count value of any one time unit is smaller than the second threshold value and the statistical times reach the first threshold value, stopping transmitting the light pulse.

21. The control method according to claim 18, wherein said counting the counts of the photon signals in each of the detection periods once, thereby counting the counts of the photon signals in a plurality of the detection periods a plurality of times to output a histogram with respect to time and a count value, comprises:

22. The control method according to claim 19 or 20, wherein the processing the histogram to obtain distance information comprises:

23. The control method of claim 19, wherein the detection period has a value in a range of [40ns, 100ns ], and the time unit has a value in a range of [50ps, 400ps ].

24. One or more non-transitory computer-readable storage media storing a computer program that, when executed by one or more processors, implements the control method of any one of claims 13 to 23.