CN112255635A - Distance measuring method, system and equipment - Google Patents
Distance measuring method, system and equipment Download PDFInfo
- Publication number
- CN112255635A CN112255635A CN202010914316.7A CN202010914316A CN112255635A CN 112255635 A CN112255635 A CN 112255635A CN 202010914316 A CN202010914316 A CN 202010914316A CN 112255635 A CN112255635 A CN 112255635A
- Authority
- CN
- China
- Prior art keywords
- target
- photon
- histogram
- acquiring
- rising edge
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- 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
- G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
- G01S17/06—Systems determining position data of a target
- G01S17/08—Systems determining position data of a target for measuring distance only
- G01S17/10—Systems determining position data of a target for measuring distance only using transmission of interrupted, pulse-modulated waves
-
- G—PHYSICS
- 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
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/483—Details of pulse systems
- G01S7/486—Receivers
- G01S7/4865—Time delay measurement, e.g. time-of-flight measurement, time of arrival measurement or determining the exact position of a peak
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Computer Networks & Wireless Communication (AREA)
- General Physics & Mathematics (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Electromagnetism (AREA)
- Optical Radar Systems And Details Thereof (AREA)
Abstract
The application is suitable for the technical field of distance measurement, and provides a distance measuring method, which comprises the following steps: acquiring a photon emission signal and a photon reflection signal; generating a target histogram from the photon emission signal and the photon reflection signal; acquiring a rising edge position in the target histogram; and acquiring time information corresponding to the rising edge position, and calculating distance information of the target to be measured according to the time information. According to the scheme, the edge detection processing method for determining the rising edge is adopted, the distance information of the target to be measured is calculated according to the time information corresponding to the position of the rising edge, the accuracy rate of distance calculation can be improved, particularly, when the received waveform is distorted due to photon accumulation, the position of the pulse rising edge cannot be influenced, and therefore the accuracy of distance calculation is further improved.
Description
Technical Field
The present application belongs to the field of ranging technologies, and in particular, to a distance measuring method, system and device.
Background
A distance measurement may be performed on a target using a Time of Flight (TOF) principle to obtain a depth image including a depth value of the target, and a distance measurement system based on the Time of Flight principle has been widely used in the fields of consumer electronics, unmanned driving, and the like. When the distance of the target to be detected is calculated, the emitter is used for emitting a pulse light beam to irradiate a target view field, the collector is used for collecting a reflected light beam, the flight time from the emitting to the reflecting receiving of the light beam is calculated, the flight time is used as an address for accessing a corresponding memory, the flight time is measured and input into the memory for multiple times to construct a histogram, the peak position in the histogram is further determined, and the distance of the target to be detected is calculated according to the time corresponding to the peak position.
However, when the target to be detected is close in distance and the reflectivity is high, the pulse waveform drawn in the histogram is distorted, and the flight time of photons from emission to reception cannot be accurately determined, so that it is difficult to determine the distance to the target to be detected.
Disclosure of Invention
The embodiment of the application provides a distance measuring method, a distance measuring system and distance measuring equipment, and the problem that when a target to be detected is short in distance and high in reflectivity, a pulse waveform drawn in a histogram is distorted, the flight time of photons from emission to reception cannot be accurately determined, and therefore the distance of the target to be detected is difficult to determine is solved.
In a first aspect, an embodiment of the present application provides a distance measurement method, including:
acquiring a photon emission signal and a photon reflection signal;
acquiring the flight time of the photons from emission to reception according to the photon emission signal and the photon reflection signal, and generating a target histogram according to the flight time; the abscissa of the target histogram is the flight time, and the ordinate of the target histogram represents a photon count value;
and acquiring time information corresponding to the rising edge position, and calculating distance information of the target to be measured according to the time information.
Further, the acquiring a rising edge position in the target histogram includes:
determining a received waveform according to the target histogram, and constructing a fitting function curve according to the received waveform;
and acquiring a target point which meets the condition of a preset slope value in the fitting function curve, and determining the position of the rising edge according to the target point.
Further, the acquiring a rising edge position in the target histogram includes:
acquiring a difference value of photon count values in two adjacent time intervals in the target histogram;
and determining the position of the rising edge according to the difference value.
Further, the acquiring a rising edge position in the target histogram includes:
constructing an accumulation sum function corresponding to the target histogram;
acquiring a jump point in the accumulation sum function;
and determining the position of the rising edge according to the position of the jumping point.
Further, the obtaining a flight time of the photon from emission to reception according to the photon emission signal and the photon reflection signal, and generating a target histogram according to the flight time includes:
acquiring the flight time of the photons from emission to reception according to the photon emission signal and the photon reflection signal, and generating an initial histogram according to the flight time;
and correcting the initial histogram to obtain a target histogram.
Further, the correcting the initial histogram to obtain a target histogram includes:
generating a correction function according to the initial histogram;
and correcting the initial histogram according to the inverse function of the correction function to obtain a target histogram.
Further, the generating a target histogram from the photon emission signal and the photon reflection signal comprises:
determining the flight time information of the photons from emission to collection according to the photon emission signal and the reflection signal;
a time code is determined from the time of flight information, and a target histogram is generated from the time code.
In a second aspect, an embodiment of the present application provides a distance measuring apparatus, including:
the first acquisition unit is used for acquiring a photon emission signal and a photon reflection signal;
the generating unit is used for acquiring the flight time from emission to reception of the photons according to the photon emission signal and the photon reflection signal and generating a target histogram according to the flight time; the abscissa of the target histogram is the flight time, and the ordinate of the target histogram represents a photon count value;
the second acquisition unit is used for acquiring the rising edge position in the target histogram;
and the processing unit is used for acquiring time information corresponding to the rising edge position and calculating the distance information of the target to be measured according to the time information.
Further, the second obtaining unit is specifically configured to:
determining a received waveform according to the target histogram, and constructing a fitting function curve according to the received waveform;
and acquiring a target point which meets the condition of a preset slope value in the fitting function curve, and determining the position of the rising edge according to the target point.
Further, the second obtaining unit is specifically configured to:
acquiring a difference value of photon count values in two adjacent time intervals in the target histogram;
and determining the position of the rising edge according to the difference value.
Further, the second obtaining unit is specifically configured to:
constructing an accumulation sum function corresponding to the target histogram;
acquiring a jump point in the accumulation sum function;
and determining the position of the rising edge according to the position of the jumping point.
Further, the generation unit includes:
an initial generation unit for generating an initial histogram from the photon emission signal and the photon reflection signal;
and the correcting unit is used for correcting the initial histogram to obtain a target histogram.
Further, the correction unit is specifically configured to:
generating a correction function according to the initial histogram;
and correcting the initial histogram according to the inverse function of the correction function to obtain a target histogram.
Further, the generating unit is specifically configured to:
determining the flight time information of the photons from emission to collection according to the photon emission signal and the reflection signal;
a time code is determined from the time of flight information, and a target histogram is generated from the time code.
In a third aspect, an embodiment of the present application provides a distance measurement system, including: the system comprises a transmitter, a collector and processing equipment;
the emitter is used for generating photon emission signals and emitting pulse beams to the target to be measured after receiving the emission instructions sent by the processing equipment;
the collector is used for collecting photons in the pulsed light beam reflected by the target to be measured and generating a photon reflection signal; the collector comprises a pixel array;
the processing equipment is used for acquiring the photon emission signal and the photon reflection signal corresponding to the target to be detected; acquiring the flight time of the photons from emission to reception according to the photon emission signal and the photon reflection signal, and generating a target histogram according to the flight time; the abscissa of the target histogram is the flight time, and the ordinate of the target histogram represents a photon count value; and acquiring time information corresponding to the rising edge position, and calculating the distance information of the target to be measured according to the time information.
In a fourth aspect, an embodiment of the present application provides a distance measuring apparatus, including a memory, a processor, and a computer program stored in the memory and executable on the processor, where the processor implements the distance measuring method according to the first aspect when executing the computer program.
In a fifth aspect, the present application provides a computer-readable storage medium, which stores a computer program, and when the computer program is executed by a processor, the computer program implements the distance measurement method according to the first aspect.
In the embodiment of the application, a photon emission signal and a photon reflection signal are obtained; generating a target histogram from the photon emission signal and the photon reflection signal; acquiring a rising edge position in the target histogram; and acquiring time information corresponding to the rising edge position, and calculating distance information of the target to be measured according to the time information. According to the scheme, the edge detection processing method for determining the rising edge is adopted, the distance information of the target to be measured is calculated according to the time information corresponding to the position of the rising edge, the accuracy rate of distance calculation can be improved, particularly, when the received waveform is distorted due to photon accumulation, the position of the pulse rising edge cannot be influenced, and therefore the accuracy of distance calculation is further improved.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.
FIG. 1 is a schematic view of a distance measuring system provided in a first embodiment of the present application;
FIG. 2 is a schematic flow chart diagram of a distance measuring method according to a second embodiment of the present application;
FIG. 3 is a schematic diagram of a target histogram in a distance measurement method according to a second embodiment of the present application;
fig. 4 is a schematic flowchart of a refinement of S102 in a distance measurement method according to a second embodiment of the present application;
fig. 5 is a schematic flowchart of a refinement at S1022 in a distance measurement method provided in a second embodiment of the present application;
fig. 6 is a schematic flowchart of a refinement of S103 in a distance measurement method according to a second embodiment of the present application;
fig. 7 is a schematic flowchart of a refinement of S103 in a distance measurement method according to a second embodiment of the present application;
fig. 8 is a schematic flowchart of a refinement of S103 in a distance measurement method according to a second embodiment of the present application;
FIG. 9 is a schematic view of a distance measuring device according to a third embodiment of the present application;
fig. 10 is a schematic view of a distance measuring apparatus according to a fourth embodiment of the present application.
Detailed Description
In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.
It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
It should also be understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.
As used in this specification and the appended claims, the term "if" may be interpreted contextually as "when", "upon" or "in response to" determining "or" in response to detecting ". Similarly, the phrase "if it is determined" or "if a [ described condition or event ] is detected" may be interpreted contextually to mean "upon determining" or "in response to determining" or "upon detecting [ described condition or event ]" or "in response to detecting [ described condition or event ]".
Furthermore, in the description of the present application and the appended claims, the terms "first," "second," "third," and the like are used for distinguishing between descriptions and not necessarily for describing or implying relative importance.
Reference throughout this specification to "one embodiment" or "some embodiments," or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the present application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," or the like, in various places throughout this specification are not necessarily all referring to the same embodiment, but rather "one or more but not all embodiments" unless specifically stated otherwise. The terms "comprising," "including," "having," and variations thereof mean "including, but not limited to," unless expressly specified otherwise.
Referring to fig. 1, fig. 1 is a schematic diagram of a distance measuring system according to a first embodiment of the present disclosure. The distance measuring system as shown in fig. 1 may include: the system comprises a transmitter, a collector and processing equipment;
the emitter is used for generating photon emission signals and emitting pulse beams to the target to be measured after receiving the emission instructions sent by the processing equipment;
the collector is used for collecting photons in the pulsed light beam reflected by the target to be measured and generating a photon reflection signal; the collector comprises a pixel array;
the processing equipment is used for acquiring the photon emission signal and the photon reflection signal corresponding to the target to be detected; acquiring the flight time of the photons from emission to reception according to the photon emission signal and the photon reflection signal, and generating a target histogram according to the flight time; the abscissa of the target histogram is the flight time, and the ordinate of the target histogram represents a photon count value; and acquiring time information corresponding to the rising edge position, and calculating the distance information of the target to be measured according to the time information.
Specifically, the distance measuring system 10 may include: transmitter 11, harvester 12, and processing device 13. The transmitter 11 comprises a light source 111 consisting of one or more lasers for emitting a pulsed light beam 30 towards the target 20 to be measured, at least part of which is reflected by the target to form a reflected light beam 40 back to the collector 12. Collector 12 includes a pixel array 121 composed of a plurality of pixels for collecting photons in reflected light beam 40 and generating photon reflection signals, and processing device 13 synchronizes photon emission signals and photon reflection signals of emitter 11 and collector 12 to calculate the time of flight required for photons in the light beam from emission to reception.
The transmitter 11 includes a light source 111, a transmitting optical element 112, a driver 113, and the like. In one embodiment, light source 111 is a VCSEL array light source chip that generates multiple VCSEL light sources on a monolithic semiconductor substrate to form. The light source 111 can emit a pulse light beam outwards under the control of the processing device 13 at a certain frequency (pulse period), and the pulse light beam is projected onto the target to be measured through the emission optical element 112 to form an illumination spot, wherein the frequency is set according to the measurement distance.
In the actual distance measurement process, the photons collected by the pixel array comprise environment photons and signal photons, wherein the environment photons exist continuously in the time interval of the histogram, and the signal photons only appear in the time interval corresponding to the target position to form a pulse peak. However, because the SPAD array enters the dead time after receiving the photons and does not detect the photons any more, when the object to be detected is closer to the SPAD array or has high reflectivity, the photons in the front of the reflected pulsed light beam are more quickly incident into the SPAD array to cause the SPAD to enter the dead time after avalanche, the subsequent incident signal photons are not received by the SPAD any more, and the pulse peak position in the finally formed histogram moves forward. Or a large number of ambient photons are incident into the SPAD array under strong ambient light conditions to enable SPADs to enter dead time after avalanche occurs, at the moment, a plurality of incident signal photons cannot be collected and received by the SPADs, and the peak position in a finally formed histogram moves forward. Determining that there is a measurement error in time-of-flight from the peak locations in the distorted histogram compared to the actual time-of-flight. The above cases causing distortion of the histogram are collectively referred to as photon accumulation phenomenon. In order to solve the problem, a distance measurement method is proposed in this embodiment and applied to a processing device.
The processing device 13 is configured to obtain the photon emission signal and the photon reflection signal corresponding to the target to be detected; acquiring the flight time of the photons from emission to reception according to the photon emission signal and the photon reflection signal, and generating a target histogram according to the flight time; acquiring a rising edge position in the target histogram; and acquiring time information corresponding to the rising edge position, and calculating the distance information of the target to be measured according to the time information. Details of the distance measurement method in the specific processing apparatus can be referred to the description of the second embodiment.
Referring to fig. 2, fig. 2 is a schematic flow chart of a distance measuring method according to a second embodiment of the present application. An execution subject of the distance measurement method in this embodiment is a processing device. The distance measuring method may include:
s101: photon emission signals and photon reflection signals are acquired.
The processing device acquires photon emission signals sent by the emitter and photon reflection signals collected by the collector. The photon emission signal and the photon reflection signal are used to calculate the time of flight of the photons.
S102: acquiring the flight time of the photons from emission to reception according to the photon emission signal and the photon reflection signal, and generating a target histogram according to the flight time; the abscissa of the target histogram is the flight time, and the ordinate of the target histogram represents the photon count value.
The processing equipment acquires the flight time of the photons from emission to reception according to the photon emission signals and the photon reflection signals, and generates a target histogram according to the flight time. Wherein the abscissa of the target histogram represents the time of flight of the photons and the ordinate of the target histogram represents the photon count value. As shown in fig. 3, fig. 3 is a schematic diagram of the target histogram, and the abscissa x in the coordinate system of fig. 3 represents the time of flight from emission to collection of each photon, and the ordinate y represents the photon count value.
The method of generating the target histogram is not limited herein. In one embodiment, the processing device determines a time of flight of the photon from the photon emission signal and the photon reflection signal, and generates the target histogram using the time of flight of the photon as an abscissa and the photon count value as an ordinate. In another embodiment, the device determines time-of-flight information from emission to collection of photons from the photon emission signal and the reflection signal, then determines a time code from the time-of-flight information, and generates a target histogram from the time code. Wherein the time code is a code identifying time of flight. In this embodiment, the processing device includes a histogram memory, and the processing device may determine a location in the histogram memory where the histogram data is stored according to the time code, add "1" to a value stored at the corresponding location, and construct the target histogram according to the location of the histogram memory as a time interval. Wherein the target histogram includes measurement errors due to photon pile-up effects.
It will be appreciated that the histogram generated from the photon emission signal and the photon reflection signal may be corrected in order to obtain an accurate target histogram, i.e. the peak of the waveform shifted forward is corrected back to its correct position, since the photon pile-up effect may cause the peak position of the received waveform reflected from the target to shift forward, for example, to be located at the 7 th time interval, and the photon pile-up effect may cause the peak position to shift forward to the 5 th time interval, and the time of flight obtained from the peak position is smaller than the actual time of flight. S102 may include S1021 to S1022, as shown in fig. 4, where S1021 to S1022 are specifically as follows:
s1021: and acquiring the flight time of the photon from emission to reception according to the photon emission signal and the photon reflection signal, and generating an initial histogram according to the flight time.
The detailed manner of generating the initial histogram by the processing device may refer to the description in S102 that the processing device obtains the flight time of the photon from emission to reception according to the photon emission signal and the photon reflection signal, and generates the target histogram according to the flight time, which is not described herein again.
S1022: and correcting the initial histogram to obtain a target histogram.
And the processing equipment corrects the initial histogram to obtain a target histogram, and the specific correction mode is not limited. The processing device may pre-store a preset policy, and correct the initial histogram according to the correction policy to obtain the target histogram.
In one embodiment, S1022 may include S10221 to S10222, as shown in fig. 5, S10221 to S10222 are specifically as follows:
s10221: and generating a correction function according to the initial histogram.
The processing device generates a correction function from the initial histogram, the correction function being used to correct information of distortions in the initial histogram, i.e. measurement errors arising in the initial histogram due to photon pile-up effects. The correction function may be a time domain function or a frequency domain function.
The processing device may construct the time domain function using a relationship between different detection efficiencies of the pixel array and a peak offset caused by the photon accumulation effect, or construct the time domain function using a relationship between different distances of the target and a peak offset caused by the photon accumulation effect, and use the time domain function as the correction function.
The processing device may also generate a frequency domain function corresponding to the initial histogram according to the initial histogram, and use the frequency domain function as the correction function.
S10222: and correcting the initial histogram according to the inverse function of the correction function to obtain a target histogram.
And the processing equipment corrects the initial histogram according to the inverse function of the correction function, and corrects the initial histogram to obtain a target histogram by taking the inverse function of the correction function as a preprocessing parameter.
S103: and acquiring the position of a rising edge in the target histogram.
The processing device obtains a rising edge position in the target histogram, wherein the rising edge position is a position in the histogram that changes from low to high, and a schematic diagram of the rising edge position is shown as 302 in fig. 3. The manner in which the processing device obtains the position of the rising edge is not limited herein, and several specific ways of obtaining the position of the rising edge are described in detail below.
In one embodiment, the processing device may acquire the rising edge position in the following manner, and S103 may include S1031 to S1032, as shown in fig. 6, where S1031 to S1032 are specifically as follows:
s1031: and determining a received waveform according to the target histogram, and constructing a fitting function curve according to the received waveform.
The processing device determines a received waveform from the target histogram, wherein the received waveform is a received waveform characterizing the reflected light beam, and a schematic diagram of the received waveform can be referred to as 303 in fig. 3. After the received waveform is obtained, the processing equipment processes the received waveform and constructs a fitting function curve. Wherein the abscissa of the fitted function curve represents the time of flight and the ordinate represents the photon count value.
S1032: and acquiring a target point which meets the condition of a preset slope value in the fitting function curve, and determining the position of the rising edge according to the target point.
The processing equipment acquires a target point which meets the preset slope value condition in the fitting function curve, the target point which meets the preset slope value condition is a point with the maximum slope value in the fitting function curve, and the time interval corresponding to the x value at the target point is the rising edge position of the target histogram.
In one embodiment, the processing device may obtain the rising edge position in the following manner, and S103 may include S1033 to S1034, as shown in fig. 7, where S1033 to S1034 are specifically as follows:
s1033: and acquiring the difference value of the photon counting values in two adjacent time intervals in the target histogram.
The processing device obtains a difference value of photon count values in two adjacent time intervals in the target histogram. In this embodiment, the rising edge position is determined by directly calculating the difference between the photon count values in at least two time intervals in the histogram. Wherein the photon count value in the time interval at the position of the rising edge is much larger than the photon count value in the time interval before it. Thus, the processing device may set a difference threshold value, continuously calculate the difference of the photon count values in two adjacent time intervals, or may also calculate the difference of the photon count values in two non-consecutive time intervals, where non-consecutive indicates time intervals having equal or unequal amounts of separation. When the difference between the two time intervals satisfies the threshold, the time interval with the large photon count value is determined as the rising edge position.
S1034: and determining the position of the rising edge according to the difference value.
The processing device may set a difference threshold and determine a time interval in which the photon count value is large as the rising edge position when the difference satisfies the threshold.
In one embodiment, the processing device may obtain the rising edge position in the following manner, and S103 may include S1035 to S1037, as shown in fig. 8, where S1035 to S1037 are specifically as follows:
s1035: and constructing an accumulation sum function corresponding to the target histogram.
The processing device constructs a corresponding accumulated sum function of the target histogram, wherein the abscissa x of the accumulated sum function represents the flight time, and the ordinate y is configured to be the sum of photon count values in all time bins before a certain time point, namely, y equals sum (i), i equals 1,2 … … n, wherein n is the photon count value at the nth time interval.
S1036: and acquiring a jump point in the accumulation sum function.
The constructed accumulation sum function has a jump point, and the processing equipment acquires the jump point in the accumulation function.
S1037: and determining the position of the rising edge according to the position of the jumping point.
The processing device determines the position of the trip point as the rising edge position of the target histogram.
S104: and acquiring time information corresponding to the rising edge position, and calculating distance information of the target to be measured according to the time information.
The processing equipment acquires time information corresponding to the rising edge position, the time information corresponding to the rising edge position is flight time, and the processing equipment can calculate distance information of the target to be measured according to the time information and the light speed.
It is understood that, in the prior art, the peak position is determined, and the corresponding time at the peak position is taken as the flight time to obtain the distance information of the target. However, in the ranging process, the trigger signal of the optical pulse is triggered synchronously with the timing signal, and the actually calculated flight time is the time difference of half the pulse width in the calculated flight time, with the time of the emission (rising edge) of the optical pulse as the start time and the time at the peak (middle position) of the reflected pulse as the end time. Therefore, in practical designs, it is usually necessary to adjust the rising edge of the transmitted light pulse at the transmitting end to be steeper, so that the rising edge of the transmitted light pulse approximates to the pulse peak position, which can reduce the influence of the time difference on the final distance measurement result. In the embodiment of the application, a photon emission signal and a photon reflection signal are obtained; generating a target histogram from the photon emission signal and the photon reflection signal; acquiring a rising edge position in the target histogram; and acquiring time information corresponding to the rising edge position, and calculating distance information of the target to be measured according to the time information. In the scheme of the application, an edge detection processing method for determining the rising edge is adopted, the distance information of the target to be measured is calculated according to the time information corresponding to the position of the rising edge, the accuracy rate of the calculated distance can be improved, and especially when the received waveform is distorted due to photon accumulation, such as narrowing and forward movement of a waveform, the rising edge position of a pulse cannot be influenced, so that the accuracy of the calculated distance is further improved, and the regulation and control program of the pulse transmitted by a transmitter can be reduced.
It should be understood that, the sequence numbers of the steps in the foregoing embodiments do not imply an execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.
Referring to fig. 9, fig. 9 is a schematic view of a distance measuring device according to a third embodiment of the present application. The units included are used for executing the steps in the embodiments corresponding to fig. 2, 4 to 8. Please refer to fig. 2, 4-8 for the corresponding embodiments. For convenience of explanation, only the portions related to the present embodiment are shown. Referring to fig. 9, the distance measuring device 9 includes:
a first obtaining unit 910, configured to obtain a photon emission signal and a photon reflection signal;
a generating unit 920, configured to obtain a flight time from emission to reception of a photon according to the photon emission signal and the photon reflection signal, and generate a target histogram according to the flight time; the abscissa of the target histogram is the flight time, and the ordinate of the target histogram represents a photon count value;
a second obtaining unit 930, configured to obtain a rising edge position in the target histogram;
and the processing unit 940 is configured to acquire time information corresponding to the rising edge position, and calculate distance information of the target to be measured according to the time information.
Further, the second obtaining unit 930 is specifically configured to:
determining a received waveform according to the target histogram, and constructing a fitting function curve according to the received waveform;
and acquiring a target point which meets the condition of a preset slope value in the fitting function curve, and determining the position of the rising edge according to the target point.
Further, the second obtaining unit 930 is specifically configured to:
acquiring a difference value of photon count values in two adjacent time intervals in the target histogram;
and determining the position of the rising edge according to the difference value.
Further, the second obtaining unit 930 is specifically configured to:
constructing an accumulation sum function corresponding to the target histogram;
acquiring a jump point in the accumulation sum function;
and determining the position of the rising edge according to the position of the jumping point.
Further, the generating unit 920 includes:
the initial generation unit is used for acquiring the flight time from emission to reception of the photons according to the photon emission signals and the photon reflection signals and generating an initial histogram according to the flight time;
and the correcting unit is used for correcting the initial histogram to obtain a target histogram.
Further, the correction unit is specifically configured to:
generating a correction function according to the initial histogram;
and correcting the initial histogram according to the inverse function of the correction function to obtain a target histogram.
Further, the generating unit 920 is specifically configured to:
determining the flight time information of the photons from emission to collection according to the photon emission signal and the reflection signal;
a time code is determined from the time of flight information, and a target histogram is generated from the time code.
Fig. 10 is a schematic view of a distance measuring apparatus according to a fourth embodiment of the present application. As shown in fig. 10, the distance measuring apparatus 10 of this embodiment includes: a processor 100, a memory 101 and a computer program 102, such as a distance measurement program, stored in said memory 101 and executable on said processor 100. The processor 100, when executing the computer program 102, implements the steps in the various distance measurement method embodiments described above, such as the steps 101 to 104 shown in fig. 1. Alternatively, the processor 100, when executing the computer program 102, implements the functions of the modules/units in the above-mentioned device embodiments, such as the functions of the modules 910 to 940 shown in fig. 9.
Illustratively, the computer program 102 may be partitioned into one or more modules/units that are stored in the memory 101 and executed by the processor 100 to accomplish the present application. The one or more modules/units may be a series of computer program instruction segments capable of performing specific functions, which are used to describe the execution process of the computer program 102 in the network connection establishing device 10. For example, the computer program 102 may be divided into a first acquiring unit, a generating unit, a second acquiring unit, and a processing unit, and each unit has the following specific functions:
the first acquisition unit is used for acquiring a photon emission signal and a photon reflection signal;
a generating unit for generating a target histogram from the photon emission signal and the photon reflection signal; the abscissa of the target histogram represents the flight time of photons corresponding to the photon signal, and the ordinate of the target histogram represents a photon count value;
the second acquisition unit is used for acquiring the rising edge position in the target histogram;
and the processing unit is used for acquiring time information corresponding to the rising edge position and calculating the distance information of the target to be measured according to the time information.
The distance measuring device may include, but is not limited to, a processor 100, a memory 101. Those skilled in the art will appreciate that fig. 10 is merely an example of a distance measuring device 10 and is not intended to be limiting of the distance measuring device 10 and may include more or fewer components than shown, or some components may be combined, or different components, for example, the distance measuring device may also include input output devices, network access devices, buses, etc.
The Processor 100 may be a Central Processing Unit (CPU), other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic, discrete hardware components, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
The memory 101 may be an internal storage unit of the distance measuring device 10, such as a hard disk or a memory of the distance measuring device 10. The memory 101 may also be an external storage device of the distance measuring device 10, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), or the like provided on the distance measuring device 10. Further, the distance measuring device 10 may also include both an internal storage unit and an external storage device of the distance measuring device 10. The memory 101 is used for storing the computer program and other programs and data required by the distance measuring device. The memory 101 may also be used to temporarily store data that has been output or is to be output.
It should be noted that, for the information interaction, execution process, and other contents between the above-mentioned devices/units, the specific functions and technical effects thereof are based on the same concept as those of the embodiment of the method of the present application, and specific reference may be made to the part of the embodiment of the method, which is not described herein again.
It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-mentioned division of the functional units and modules is illustrated, and in practical applications, the above-mentioned function distribution may be performed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-mentioned functions. Each functional unit and module in the embodiments may be integrated in one processing unit, or each unit may exist alone physically, or two or more units are integrated in one unit, and the integrated unit may be implemented in a form of hardware, or in a form of software functional unit. In addition, specific names of the functional units and modules are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working processes of the units and modules in the system may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
An embodiment of the present application further provides a network device, where the network device includes: at least one processor, a memory, and a computer program stored in the memory and executable on the at least one processor, the processor implementing the steps of any of the various method embodiments described above when executing the computer program.
The embodiments of the present application further provide a computer-readable storage medium, where a computer program is stored, and when the computer program is executed by a processor, the computer program implements the steps in the above-mentioned method embodiments.
The embodiments of the present application provide a computer program product, which when running on a mobile terminal, enables the mobile terminal to implement the steps in the above method embodiments when executed.
The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, all or part of the processes in the methods of the embodiments described above can be implemented by a computer program, which can be stored in a computer-readable storage medium and can implement the steps of the embodiments of the methods described above when the computer program is executed by a processor. Wherein the computer program comprises computer program code, which may be in the form of source code, object code, an executable file or some intermediate form, etc. The computer readable medium may include at least: any entity or device capable of carrying computer program code to a photographing apparatus/terminal apparatus, a recording medium, computer Memory, Read-Only Memory (ROM), Random Access Memory (RAM), an electrical carrier signal, a telecommunications signal, and a software distribution medium. Such as a usb-disk, a removable hard disk, a magnetic or optical disk, etc. In certain jurisdictions, computer-readable media may not be an electrical carrier signal or a telecommunications signal in accordance with legislative and patent practice.
In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.
Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.
In the embodiments provided in the present application, it should be understood that the disclosed apparatus/network device and method may be implemented in other ways. For example, the above-described apparatus/network device embodiments are merely illustrative, and for example, the division of the modules or units is only one logical division, and there may be other divisions when actually implementing, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not implemented. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.
Claims (10)
1. A distance measurement method applied to a processing apparatus, the method comprising:
acquiring a photon emission signal and a photon reflection signal;
acquiring the flight time of the photons from emission to reception according to the photon emission signal and the photon reflection signal, and generating a target histogram according to the flight time; the abscissa of the target histogram is the flight time, and the ordinate of the target histogram represents a photon count value;
acquiring a rising edge position in the target histogram;
and acquiring time information corresponding to the rising edge position, and calculating distance information of the target to be measured according to the time information.
2. The distance measurement method of claim 1, wherein said obtaining a rising edge position in said target histogram comprises:
determining a received waveform according to the target histogram, and constructing a fitting function curve according to the received waveform;
and acquiring a target point which meets the condition of a preset slope value in the fitting function curve, and determining the position of the rising edge according to the target point.
3. The distance measurement method of claim 1, wherein said obtaining a rising edge position in said target histogram comprises:
acquiring a difference value of photon count values in two adjacent time intervals in the target histogram;
and determining the position of the rising edge according to the difference value.
4. The distance measurement method of claim 1, wherein said obtaining a rising edge position in said target histogram comprises:
constructing an accumulation sum function corresponding to the target histogram;
acquiring a jump point in the accumulation sum function;
and determining the position of the rising edge according to the position of the jumping point.
5. The distance measurement method of claim 1, wherein said obtaining a time of flight from emission to reception of a photon from said photon emission signal and said photon reflection signal and generating a target histogram from said time of flight comprises:
acquiring the flight time of the photons from emission to reception according to the photon emission signal and the photon reflection signal, and generating an initial histogram according to the flight time;
and correcting the initial histogram to obtain a target histogram.
6. The distance measuring method according to claim 5, wherein said rectifying the initial histogram to obtain a target histogram, comprises:
generating a correction function according to the initial histogram;
and correcting the initial histogram according to the inverse function of the correction function to obtain a target histogram.
7. The distance measurement method of claim 1, wherein said generating a target histogram from said photon emission signal and said photon reflection signal comprises:
determining the flight time information of the photons from emission to collection according to the photon emission signal and the reflection signal;
a time code is determined from the time of flight information, and a target histogram is generated from the time code.
8. A distance measuring system, comprising: the system comprises a transmitter, a collector and processing equipment;
the emitter is used for generating photon emission signals and emitting pulse beams to the target to be measured after receiving the emission instructions sent by the processing equipment;
the collector is used for collecting photons in the pulsed light beam reflected by the target to be measured and generating a photon reflection signal; the collector comprises a pixel array;
the processing equipment is used for acquiring the photon emission signal and the photon reflection signal corresponding to the target to be detected; acquiring the flight time of the photons from emission to reception according to the photon emission signal and the photon reflection signal, and generating a target histogram according to the flight time; the abscissa of the target histogram is the flight time, and the ordinate of the target histogram represents a photon count value; acquiring a rising edge position in the target histogram; and acquiring time information corresponding to the rising edge position, and calculating the distance information of the target to be measured according to the time information.
9. A distance measuring device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that the processor implements the method according to any of claims 1 to 7 when executing the computer program.
10. A computer-readable storage medium, in which a computer program is stored which, when being executed by a processor, carries out the method according to any one of claims 1 to 7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010914316.7A CN112255635A (en) | 2020-09-03 | 2020-09-03 | Distance measuring method, system and equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010914316.7A CN112255635A (en) | 2020-09-03 | 2020-09-03 | Distance measuring method, system and equipment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112255635A true CN112255635A (en) | 2021-01-22 |
Family
ID=74224339
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010914316.7A Pending CN112255635A (en) | 2020-09-03 | 2020-09-03 | Distance measuring method, system and equipment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112255635A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113514842A (en) * | 2021-03-08 | 2021-10-19 | 奥诚信息科技(上海)有限公司 | Distance measuring method, system and device |
| WO2022113438A1 (en) * | 2020-11-30 | 2022-06-02 | 北陽電機株式会社 | Optical distance measurement device and optical distance measurement method |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6137584A (en) * | 1996-11-27 | 2000-10-24 | Max-Planck-Gesellschaft Zur | Method and device for determining predetermined properties of target particles of a sample medium |
| CN105911536A (en) * | 2016-06-12 | 2016-08-31 | 中国科学院上海技术物理研究所 | Multichannel photon counting laser radar receiver possessing real-time door control function |
| CN106611951A (en) * | 2015-10-21 | 2017-05-03 | 中国电力科学研究院 | Power distribution network multi-objective reactive power optimization method based on two-stage particle swarm optimization |
| WO2018081166A1 (en) * | 2016-10-24 | 2018-05-03 | Xia Llc | Ratio-reference measurement of the arrival time and/or amplitude of a digitized electronic pulse |
| CN109844563A (en) * | 2016-08-12 | 2019-06-04 | 法斯特里3D公司 | The method and apparatus for measuring range-to-go in a multi-user environment by least one detector |
| CN110596724A (en) * | 2019-09-19 | 2019-12-20 | 深圳奥锐达科技有限公司 | Method and system for measuring flight time distance during dynamic histogram drawing |
| CN110632578A (en) * | 2019-08-30 | 2019-12-31 | 深圳奥锐达科技有限公司 | System and method for time-coded time-of-flight distance measurement |
| CN110632576A (en) * | 2019-08-30 | 2019-12-31 | 深圳奥锐达科技有限公司 | Time coding demodulation processing circuit and method |
-
2020
- 2020-09-03 CN CN202010914316.7A patent/CN112255635A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6137584A (en) * | 1996-11-27 | 2000-10-24 | Max-Planck-Gesellschaft Zur | Method and device for determining predetermined properties of target particles of a sample medium |
| CN106611951A (en) * | 2015-10-21 | 2017-05-03 | 中国电力科学研究院 | Power distribution network multi-objective reactive power optimization method based on two-stage particle swarm optimization |
| CN105911536A (en) * | 2016-06-12 | 2016-08-31 | 中国科学院上海技术物理研究所 | Multichannel photon counting laser radar receiver possessing real-time door control function |
| CN109844563A (en) * | 2016-08-12 | 2019-06-04 | 法斯特里3D公司 | The method and apparatus for measuring range-to-go in a multi-user environment by least one detector |
| WO2018081166A1 (en) * | 2016-10-24 | 2018-05-03 | Xia Llc | Ratio-reference measurement of the arrival time and/or amplitude of a digitized electronic pulse |
| CN110632578A (en) * | 2019-08-30 | 2019-12-31 | 深圳奥锐达科技有限公司 | System and method for time-coded time-of-flight distance measurement |
| CN110632576A (en) * | 2019-08-30 | 2019-12-31 | 深圳奥锐达科技有限公司 | Time coding demodulation processing circuit and method |
| CN110596724A (en) * | 2019-09-19 | 2019-12-20 | 深圳奥锐达科技有限公司 | Method and system for measuring flight time distance during dynamic histogram drawing |
Non-Patent Citations (2)
| Title |
|---|
| 田颖;王爽;任科;: "用于超快光计时的时间数字转换器", 半导体光电, no. 03 * |
| 赵帅;郭劲;刘洪波;冯强;: "多像素光子计数器在单光子探测中的应用", 光学精密工程, no. 05 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022113438A1 (en) * | 2020-11-30 | 2022-06-02 | 北陽電機株式会社 | Optical distance measurement device and optical distance measurement method |
| CN113514842A (en) * | 2021-03-08 | 2021-10-19 | 奥诚信息科技(上海)有限公司 | Distance measuring method, system and device |
| WO2022188884A1 (en) * | 2021-03-08 | 2022-09-15 | 奥诚信息科技(上海)有限公司 | Distance measurement method, system and device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112255636A (en) | Distance measuring method, system and equipment | |
| US20210382964A1 (en) | Method and apparatus for processing a histogram output from a detector sensor | |
| WO2022160611A1 (en) | Time fusion-based distance measurement method, system, and device | |
| CN110622038B (en) | Optical sensor, electronic device, computing device, and method for measuring distance between optical sensor and detection object | |
| CN112114324B (en) | Distance measurement method, device, terminal equipment and storage medium | |
| TWI723413B (en) | System and method for measuring a distance between an imaging sensor and an object | |
| US20230341529A1 (en) | Target detection method, lidar and storage medium | |
| CN112255635A (en) | Distance measuring method, system and equipment | |
| EP3721261B1 (en) | Distance time-of-flight modules | |
| WO2022188884A1 (en) | Distance measurement method, system and device | |
| US20230236298A1 (en) | Systems and methods for detecting an electromagnetic signal in a constant interference environment | |
| CN115755078A (en) | Laser radar ranging method, laser radar and storage medium | |
| CN112255637B (en) | Distance measuring system and method | |
| WO2022160622A1 (en) | Distance measurement method, device, and system | |
| US20230204723A1 (en) | Lidar control method, terminal apparatus, and computer-readable storage medium | |
| CN116256767A (en) | Laser radar flight time measurement method and system | |
| CN115792938A (en) | Distance measuring method and device with error compensation function and depth sensor | |
| CN115267744A (en) | Flight time distance measuring method and device | |
| CN114814881A (en) | Laser ranging method and laser ranging chip | |
| CN113848558A (en) | Flight time distance measuring system and method | |
| WO2024130608A1 (en) | Time-of-flight measurement method and apparatus, and laser ranging apparatus and storage medium | |
| WO2023279618A1 (en) | Distance measurement system, and method for shielding fuzzy distance value | |
| US20220308173A1 (en) | Anti flicker filter for dtof sensor | |
| CN118041444B (en) | Method for calculating transmission time delay of optical pulse signal | |
| CN115047435A (en) | Optical sensing assembly, optical sensing device, electronic device and sensing method of optical sensing device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |