CN113075672A - Ranging method and system, and computer readable storage medium - Google Patents
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- 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
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- 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
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- 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
- G01S7/491—Details of non-pulse systems
- G01S7/4912—Receivers
- G01S7/4915—Time delay measurement, e.g. operational details for pixel components; Phase measurement
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- 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
- G01S7/497—Means for monitoring or calibrating
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Abstract
The invention relates to a distance measuring method and system and a computer readable storage medium, wherein the method comprises the following steps: acquiring first light intensity positive correlation data of each sensing unit of a sensing module in a state that a light emitter emits detection light; acquiring second light intensity positive correlation data of each sensing unit of the sensing module in a non-luminous state of the light emitter; determining the position of the detection light spot irradiated on the sensing module according to the compensation data obtained by subtracting the second light intensity positive correlation data from the first light intensity positive correlation data of each sensing unit; controlling the light emitter to emit detection light; and opening the sensing unit corresponding to the position to receive the detection light reflected by the target object, and obtaining the distance of the target object according to the sensing signal received by the sensing unit. According to the invention, ambient light is offset by subtracting light intensity data of two exposures of the sensing module to obtain information close to scattered light intensity distribution, the chip logic is simpler to realize, and the determined position of the light spot of the detection light is accurate, so that an accurate distance measurement result is obtained.
Description
Technical Field
The present invention relates to electromagnetic ranging, and more particularly, to a method and system for ranging and a computer-readable storage medium.
Background
The Time of Flight (ToF) technique is a 3D imaging technique that emits probe light from a transmitter and reflects the probe light back to a receiver through a target object, thereby obtaining a spatial distance from the object to a sensor based on a propagation Time of the probe light in the propagation path.
In the ToF scheme based on the separate arrangement of the transmitting end and the receiving end, there is disparity between the transmitting end and the receiving end. Therefore, the reflected signals of the laser beam emitted by the emitting end at different distances can be irradiated on different pixels of the image sensor. In the ToF scheme, when the laser light at the emitting end is distributed in scattered spots, the effective laser light is mixed in a large amount of ambient light. The position of the reflected light spot on the sensor array is judged according to the information obtained by the SPAD pixel of the receiving end, then the corresponding sensor is opened, and the triggered histogram is counted, otherwise, a very low signal-to-noise ratio is obtained, or the signal cannot be detected, so that the distance estimation error is caused.
Disclosure of Invention
Based on this, it is necessary to provide a ranging method capable of accurately obtaining the scattered point position.
A method of ranging, comprising:
acquiring first light intensity positive correlation data of each sensing unit of a sensing module in a state that a light emitter emits detection light;
acquiring second light intensity positive correlation data of each sensing unit of the sensing module in a non-luminous state of the light emitter;
determining the position of the detection light spot irradiated on the sensing module according to the light intensity positive correlation compensation data obtained by subtracting the second light intensity positive correlation data from the first light intensity positive correlation data of each sensing unit;
controlling the light emitter to emit detection light;
opening the sensing unit corresponding to the position to receive the detection light reflected by the target object, and obtaining the distance of the target object according to the sensing signal received by the sensing unit;
wherein the first light intensity positive correlation data and the second light intensity positive correlation data are positively correlated with the light intensity sensed by each sensing unit.
According to the distance measurement method, ambient light (light except the detection light) is offset by subtracting the light intensity data of the two exposures of the sensing module, so that information close to scattered light intensity distribution is obtained, the chip logic is relatively simple to realize, the position of the light spot of the detection light is relatively accurate, and accordingly, an accurate distance measurement result is obtained subsequently.
In one embodiment, the step of determining the position of the probe light spot irradiated on the sensing module according to the light intensity positive correlation compensation data obtained by subtracting the second light intensity positive correlation data from the first light intensity positive correlation data of each sensing unit comprises:
and determining a plurality of adjacent sensing units with relatively highest light intensity positive correlation compensation data as the positions.
In one embodiment, if the plurality of adjacent sensing units with the highest light intensity positive correlation compensation data do not reach the light intensity threshold, the preset sensing unit is used as the position.
In one embodiment, the number and the arrangement combination mode of the sensing units of the plurality of adjacent sensing units with the highest light intensity positive correlation compensation data are preset;
the method further comprises the following steps: if more than two regions reaching the light intensity threshold exist in the light intensity positive correlation compensation data, and the number of sensing units and the shape arrangement combination mode of the regions are the same as those of the preset regions, it is determined that scattered points appear, the regions are used as the positions, and the distance of the multi-target object is obtained in the step of obtaining the distance of the target object.
In one embodiment, the light intensity threshold is a preset value that depends on the measurement accuracy and/or the ambient light intensity.
In one embodiment, the locations are stripe-shaped partitions.
In one embodiment, the step of determining the position of the probe light spot irradiated on the sensing module according to the light intensity positive correlation compensation data obtained by subtracting the second light intensity positive correlation data from the first light intensity positive correlation data of each sensing unit comprises:
counting the sum of the light intensity positive correlation compensation data of each induction partition of the sensing module according to the light intensity positive correlation compensation data; each sensing partition includes at least one sensing element.
In one embodiment, the step of opening the sensing unit corresponding to the position to receive the probe light reflected by the target object includes: and opening the induction subarea of which the sum of the light intensity positive correlation compensation data reaches the light intensity threshold value, and receiving the detection light reflected by the target object.
In one embodiment, the step of obtaining the target object distance according to the sensing signal received by the sensing unit includes: and multiplying the amplitude of the sensing signal of each sensing subarea by the sum of the light intensity positive correlation compensation data to obtain the flight time, and obtaining the target object distance according to the flight time.
In one embodiment, the step of multiplying the amplitude of the sensing signal of each sensing partition by the sum of the light intensity positive correlation compensation data to obtain the flight time comprises:
acquiring a first histogram corresponding to the sensing signal;
obtaining data combination to form a second histogram after multiplying the sum of the amplitude and the light intensity positive correlation compensation data;
and obtaining the flight time according to the second histogram.
In one embodiment, the sensing module comprises an array of single photon avalanche diodes, each single photon avalanche diode being a sensing unit.
In one embodiment, the method further comprises the steps of writing the first light-intensity positive correlation data into a register and writing the light-intensity positive correlation compensation data into a register; the second light-intensity positive correlation data is not written to the register.
In one embodiment, in the step of subtracting the second light intensity positive correlation data from the first light intensity positive correlation data of each sensing unit, the light intensity value of the sensing unit with the subtraction value smaller than 0 is recorded as 0 or a corresponding negative value.
In one embodiment, the step of obtaining the distance of the target object according to the sensing signal received by the sensing unit includes: and obtaining the flight time by constructing a histogram corresponding to the sensing signal, and obtaining the target object distance according to the flight time.
In one embodiment, the exposure time of the step of acquiring the first light-intensity positive correlation data of each sensing unit of the sensing module in the state that the light emitter emits the detection light is equal to the exposure time of acquiring the second light-intensity positive correlation data of each sensing unit of the sensing module in the state that the light emitter does not emit light.
It is also necessary to provide a computer device comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the ranging method according to any of the foregoing embodiments when executing the computer program.
It is also necessary to provide a computer readable storage medium, on which a computer program is stored, which when executed by a processor implements the steps in the ranging method according to any of the previous embodiments.
It is also necessary to provide a ranging system.
A ranging system, comprising:
a light emitter;
the sensing module comprises a plurality of sensing units and a sensing unit, wherein the sensing units are used for receiving the detection light reflected by the target object;
the control module is used for controlling the emission and the closing of the light emitter so as to acquire first light intensity positive correlation data of each sensing unit of the sensing module in a state that the light emitter emits detection light and second light intensity positive correlation data of each sensing unit of the sensing module in a state that the light emitter does not emit light, and determining the position of a detection light spot irradiated on the sensing module according to light intensity positive correlation compensation data obtained by subtracting the second light intensity positive correlation data from the first light intensity positive correlation data of each sensing unit; the sensing units corresponding to the positions are opened to receive the detection light reflected by the target object, and the distance of the target object is obtained according to the sensing signals received by the sensing units;
wherein the first light intensity positive correlation data and the second light intensity positive correlation data are positively correlated with the light intensity sensed by each sensing unit.
In one embodiment, the control module includes a register, and the control module is configured to add one to a corresponding register value when each sensing unit is triggered once or receives one photon in a state where the light emitter emits the detection light, and further configured to subtract one from the corresponding register value when each sensing unit is triggered once or receives one photon in a state where the light emitter does not emit light, so as to obtain the light intensity positive correlation compensation data.
In one embodiment, the control module comprises a weighting unit, wherein the weighting unit is used for counting the sum of the light intensity positive correlation compensation data of each induction partition of the sensing module according to the light intensity positive correlation compensation data; the control module opens the position, including opening the sensing subarea where the sum of the light intensity positive correlation compensation data reaches a light intensity threshold; the control module obtains the distance of the target object according to the sensing signals received by the sensing units, and comprises the steps of multiplying the amplitude of the sensing signals of each sensing subarea by the sum of the light intensity positive correlation compensation data to obtain the flight time, and obtaining the distance according to the flight time;
wherein each sensing partition comprises at least one sensing unit.
In one embodiment, the control module comprises a plurality of time-to-digital converters, and the control module multiplies the sum of the amplitude of the sensing signal of each sensing partition and the light intensity positive correlation compensation data to obtain the flight time, and comprises: and obtaining a first histogram corresponding to each induction zone through the time-to-digital converter, obtaining data combination to form a second histogram after multiplying the sum of the amplitude and the light intensity positive correlation compensation data, and obtaining the flight time according to the second histogram.
In one embodiment, the sensing module comprises an array of single photon avalanche diodes, each single photon avalanche diode being a sensing unit.
Drawings
For a better understanding of the description and/or illustration of embodiments and/or examples of those inventions disclosed herein, reference may be made to one or more of the drawings. The additional details or examples used to describe the figures should not be considered as limiting the scope of any of the disclosed inventions, the presently described embodiments and/or examples, and the presently understood best modes of these inventions.
FIG. 1 is a flow diagram of a ranging method in one embodiment;
FIG. 2 is a diagram illustrating an exemplary light intensity distribution obtained from a first light intensity data obtained from a first exposure and a second light intensity data obtained from a second exposure in one embodiment;
FIG. 3 is a diagram illustrating an embodiment of distance measurement using light intensity distribution by weighting;
FIG. 4 is a diagram illustrating a ranging system according to an embodiment.
Detailed Description
To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
It will be understood that when an element or layer is referred to as being "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it can be directly on, adjacent to, connected or coupled to the other elements or layers or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly adjacent to," "directly connected to" or "directly coupled to" other elements or layers, there are no intervening elements or layers present. It will be understood that, although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.
Spatial relational terms such as "under," "below," "under," "above," "over," and the like may be used herein for convenience in describing the relationship of one element or feature to another element or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, then elements or features described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary terms "under" and "under" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatial descriptors used herein interpreted accordingly.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, 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. As used herein, the term "and/or" includes any and all combinations of the associated listed items.
The application provides a distance measurement method, which comprises the steps of firstly determining the position of a probe light spot irradiated on a sensing module (the sensing module comprises a plurality of sensing units), and then opening each sensing unit at the position to receive probe light for distance measurement. FIG. 1 is a flow chart of a ranging method in an embodiment, comprising the steps of:
s110, acquiring first light intensity positive correlation data of each sensing unit of the sensing module in a state that the light emitter emits the detection light.
The sensing module comprises a plurality of sensing units. The light emitter may employ a laser light source, such as a pulsed laser (the term "light" is used in this application to refer to any kind of optical radiation, including radiation in the visible, infrared and ultraviolet ranges, etc.). The light emitter may further include an optical unit including at least one of a lens, a galvanometer, a scan mirror, and a mirror, the optical unit being used to reduce a divergence angle of the light beam, adjust a deflection angle of the light beam, and the like.
In an embodiment of the present application, step S110 controls the light emitter to emit the probe light, and turns on all sensing units of the sensing module to perform the first exposure. In one embodiment of the present application, the sensing module comprises an array of SPADs, each sensing cell being a single photon avalanche diode. Each SPAD may also include associated bias and/or control circuit elements, such as Quench (Quench) circuits connected to the SPAD. SPADs, also known as geiger-mode avalanche photodiodes (GAPDs), are detectors capable of capturing single photons with very high arrival time resolution, on the order of tens of picoseconds, and can be fabricated with either dedicated semiconductor processes or standard CMOS processes. A single SPAD can be regarded as a 1-bit ultra-high-speed ADC (analog-to-digital converter), and a simple inverter is connected to directly generate digital signals, such as 0 output when no signal exists and 1 output when a signal exists. In other embodiments, the sensing unit may also be a photomultiplier tube, a charge coupled device, or other device that converts an optical signal into an electrical signal.
The first light intensity positive correlation data of each sensing unit is positively correlated with the light intensity of the received light signal. In one embodiment of the present application, the first light intensity positive correlation data is the number of triggering of the SPAD; in another embodiment of the present application, the first light intensity positive correlation data is the number of photons received by the SPAD. The first light intensity positive correlation data is recorded, for example, may be written into a register.
And S120, acquiring second light intensity positive correlation data of each sensing unit of the sensing module in a non-luminous state of the light emitter.
And controlling the light emitter to be closed (not to emit light), and opening all the sensing units of the sensing module to carry out second exposure. It will be appreciated that the time interval between exposures is very short. In one embodiment of the present application, the exposure time of the two exposures is the same. In an embodiment of the present application, step S120 may be performed first, and then step S110 may be performed.
Similarly, the second light intensity positive correlation data of each sensing unit is positively correlated with the light intensity of the received light signal.
And S130, determining the position of the detection light spot according to the light intensity positive correlation compensation data obtained by subtracting the second light intensity positive correlation data from the first light intensity positive correlation data.
In an embodiment of the application, the second light-intensity positive correlation data obtained in step S120 is not written into the register, but each sensing unit subtracts the second light-intensity positive correlation data from the first light-intensity positive correlation data to obtain the light-intensity positive correlation compensation data of each sensing unit of the whole sensing module. In one embodiment of the present application, the light intensity positive correlation compensation data may be written in a register. Because the interval between two exposures is short, the ambient light basically keeps unchanged, and the sensing module light intensity positive correlation compensation data obtained by subtracting the second light intensity positive correlation data from the first light intensity positive correlation data can reflect the position of the detection light spot irradiated on the sensing module.
Referring to fig. 2 (data of the sensing units in the lower 5 rows in fig. 2 are omitted, and circles indicate probe light spots), in an embodiment of the present application, the light intensity value of the sensing unit that is subtracted by step S130 and is less than 0 is recorded as 0. Specifically, step S110 is to add one to the register value of the corresponding sensing unit when each sensing unit triggers once/receives one photon; step S120, when each sensing unit is triggered once/receives a photon, the register value of the corresponding sensing unit is reduced by one; in an embodiment of the present application, if the register value is decreased to 0 in step S120, the step S stops, and the decreasing is not continued, so as to finally obtain the light intensity positive correlation compensation data.
In one embodiment of the present application, the spot position is obtained by filtering the light intensity positive correlation compensation data. If the two-dimensional coordinates of the light spot on the sensing module need to be determined, two-dimensional filtering can be performed, and a plurality of adjacent sensing units with relatively highest light intensity can be determined as the position of the light spot. Specifically, the maximum value can be obtained by a method of summing rectangular frames, and each sensing unit where the maximum value is located corresponds to the location of the scatter point. In one embodiment of the present application, the sum of the light intensity values of each set of 2 × 2 sensing units is calculated according to the light intensity positive correlation compensation data, and the sensing unit with the largest sum of the light intensity values is determined as the light spot position.
In an embodiment of the present application, if the plurality of adjacent sensing units with relatively highest light intensity do not reach the light intensity threshold, the predetermined sensing unit is used as the position. For the case where the minimum value does not reach the light intensity threshold, then no scatter is deemed to be present and a default position may be employed. In an embodiment of the application, the light intensity threshold is a preset value depending on the measurement accuracy and/or the ambient light intensity.
In an embodiment of the present application, the number and the arrangement combination manner of the sensing units of the plurality of adjacent sensing units with relatively highest light intensity are preset (as described in the foregoing embodiment, in an embodiment, the number and the arrangement combination manner of the sensing units are 2 × 2 rectangular frames). If more than two areas reaching the light intensity threshold exist in the light intensity positive correlation compensation data, and the number and the arrangement combination mode of the sensing units in the areas are the same as those of the preset areas, it is judged that multiple scattered points appear, the areas are used as the positions of light spots, and the distance of multiple targets is calculated according to the multiple scattered points in the subsequent distance measurement step.
In an embodiment of the present application, step S130 only determines the position of the row or column where the light spot is located, which is a simpler and more mature chip implementation method in the industry, for example, using sigma-delta method, which can simplify the chip design.
And S210, controlling the light emitter to emit detection light.
And after the light spot position is determined, controlling the light emitter to emit the detection light, and opening the sensing unit of the light spot position.
S220, opening the sensing unit corresponding to the light spot position to receive the detection light reflected by the target object, and ranging according to the sensing signal.
And the sensing unit corresponding to the position of the opening light spot receives the detection light reflected by the target object, and the distance between the target object and the light emitter is obtained according to the sensing signal received by the sensing unit. Specifically, a corresponding histogram can be obtained according to the sensing signal, then the flight time can be obtained according to the histogram, and then the distance between the target object and the light emitter can be calculated according to the flight time.
According to the distance measurement method, ambient light (light except probe light) is offset by subtracting the light intensity positive correlation data of the two exposures of the sensing module, so that information close to scattered light intensity positive correlation compensation data is obtained, the chip logic is relatively simple to realize, the spot position of the probe light determined according to the information is relatively accurate, and therefore an accurate distance measurement result is obtained subsequently.
In one embodiment of the present application, the spot position is determined and the distance is measured by using the difference between the first light-intensity positive correlation data and the second light-intensity positive correlation data in a weighted manner.
Specifically, step S130 counts the sum of the light intensity positive correlation compensation data of each sensing partition of the sensing module according to the light intensity positive correlation compensation data. Each sensing partition of the sensing module comprises at least one sensing unit. In one embodiment of the present application, the sensing modules may be striped to form the sensing partitions. In the embodiment shown in FIG. 3, each sensing sector is a full row of sensing elements, and FIG. 3 has a total of 8 sensing sectors.
Accordingly, step S220 includes:
s222, opening the induction subarea of which the sum of the light intensity positive correlation compensation data reaches the light intensity threshold value, and receiving the detection light reflected by the target object. The light intensity threshold is a preset value, may depend on the measurement accuracy and/or the ambient light intensity, and may be a different value than the light intensity threshold referred to in step S130.
And S224, multiplying the amplitude of the sensing signal of each sensing subarea by the sum of the light intensity to obtain the flight time.
And S226, obtaining the distance of the target object according to the flight time.
Referring to fig. 3, in one embodiment of the present application, step S224 includes: and acquiring a first histogram corresponding to the sensing signals of each sensing partition, combining data obtained by multiplying the amplitude of the sensing signals by the sum of the light intensity to form a second histogram, and obtaining the flight time according to the second histogram. In the embodiment shown in fig. 3, the ranging system includes weighting units W1 to W8 corresponding to the sensing partitions one to one, and Time-to-Digital converters TDC1 to TDC8, and a first histogram is obtained by each Time-to-Digital Converter (TDC). The TDC is a device that realizes time-to-digital signal conversion, and is a circuit structure that can accurately measure the time interval between a start pulse signal and a stop pulse signal.
It should be understood that, although the steps in the flowchart of fig. 1 are shown in order as indicated by the arrows, the steps are not necessarily performed in order as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least a portion of the steps in fig. 1 may include multiple steps or multiple stages, which are not necessarily performed at the same time, but may be performed at different times, which are not necessarily performed in sequence, but may be performed in turn or alternately with other steps or at least a portion of the other steps or stages.
It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by hardware instructions of a computer program, which can be stored in a non-volatile computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. Any reference to memory, storage, database or other medium used in the embodiments provided herein can include at least one of non-volatile and volatile memory. Non-volatile Memory may include Read-Only Memory (ROM), magnetic tape, floppy disk, flash Memory, optical storage, or the like. Volatile Memory can include Random Access Memory (RAM) or external cache Memory. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM), among others.
The present application also provides a computer program product comprising a computer program which, when executed by a processor, performs the steps of the ranging method according to any of the previous embodiments.
The present application further provides a computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, implements the steps of the ranging method according to any of the previous embodiments.
The present application further provides a computer device, which includes a memory and a processor, where the memory stores a computer program, and the processor implements the steps in the ranging method according to any of the foregoing embodiments when executing the computer program.
As shown in fig. 4, the ranging system includes a light emitter 110, a sensing module 210 and a control module 230, wherein the control module 230 is electrically connected to the sensing module 210.
The control module 230 is used to implement the steps in the ranging method according to any of the foregoing embodiments. In an embodiment of the present application, the control module 230 is configured to control the emission and the shutdown of the light emitter, so as to obtain a first light-intensity positive correlation data of each sensing unit of the sensing module 210 in a state that the light emitter 110 emits the detection light, and obtain a second light-intensity positive correlation data of each sensing unit of the sensing module 210 in a state that the light emitter 110 does not emit light, and determine a position on the sensing module 210 where the detection light spot irradiates according to the light-intensity positive correlation compensation data obtained by subtracting the second light-intensity positive correlation data from the first light-intensity positive correlation data of each sensing unit. In an embodiment of the present application, under the control of the control module 230, the exposure time corresponding to the first light intensity positive correlation data obtained by the sensing module 210 is the same as the exposure time corresponding to the second light intensity positive correlation data obtained.
After the light spot position is determined, the control module 230 is further configured to turn on the sensing unit corresponding to the light spot position, receive the probe light reflected by the target object, and obtain the distance to the target object according to the sensing signal received by the sensing unit.
In one embodiment of the present application, the control module 230 includes a register. In the exposure state of the sensing module in which the light emitter 110 emits the detection light, the control module 230 increments the corresponding register value by one when each sensing unit is triggered once or receives one photon. In the exposure state of the sensing module in which the light emitter 110 does not emit light, the control module 230 decreases the corresponding register value by one but not below 0 when each sensing unit triggers once/receives one photon, thereby obtaining the light intensity positive correlation compensation data. In another embodiment, the register value may be further decremented to a negative number after being decremented below 0.
In one embodiment of the present application, the control module 230 includes a weighting unit for counting the sum of the light intensity positive correlation compensation data of each sensing partition of the sensing module 210 according to the light intensity positive correlation compensation data. After the light spot position is determined, the control module 230 opens the sensing sub-area where the sum of the light intensity positive correlation compensation data reaches the light intensity threshold, multiplies the amplitude of the sensing signal of each sensing sub-area by the sum of the light intensity positive correlation compensation data to obtain the flight time, and obtains the distance between the target object and the target object according to the flight time. The light intensity threshold value is a preset value.
In one embodiment of the present application, the control module 230 includes a plurality of time-to-digital converters. The control module 230 obtains the first histogram corresponding to each sensing partition through the time-to-digital converter, combines the data obtained by multiplying the amplitude value of the sensing signal by the sum of the light intensity to form a second histogram, and obtains the flight time according to the second histogram.
In the description herein, references to the description of "some embodiments," "other embodiments," "desired embodiments," 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 invention. In this specification, a schematic description of the above terminology may not necessarily refer to the same embodiment or example.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (20)
1. A method of ranging, comprising:
acquiring first light intensity positive correlation data of each sensing unit of a sensing module in a state that a light emitter emits detection light;
acquiring second light intensity positive correlation data of each sensing unit of the sensing module in a non-luminous state of the light emitter;
determining the position of the detection light spot irradiated on the sensing module according to the light intensity positive correlation compensation data obtained by subtracting the second light intensity positive correlation data from the first light intensity positive correlation data of each sensing unit;
controlling the light emitter to emit detection light;
opening the sensing unit corresponding to the position to receive the detection light reflected by the target object, and obtaining the distance of the target object according to the sensing signal received by the sensing unit;
wherein the first light intensity positive correlation data and the second light intensity positive correlation data are positively correlated with the light intensity sensed by each sensing unit.
2. The distance measuring method according to claim 1, wherein the step of determining the position of the sensing module irradiated by the probe light spot according to the light intensity positive correlation compensation data obtained by subtracting the second light intensity positive correlation data from the first light intensity positive correlation data of each sensing unit comprises:
and determining a plurality of adjacent sensing units with relatively highest light intensity positive correlation compensation data as the positions.
3. The distance measuring method according to claim 2, wherein if the plurality of adjacent sensing units with the relatively highest light intensity positive correlation compensation data do not reach the light intensity threshold, a preset sensing unit is taken as the position.
4. The distance measuring method according to claim 2 or 3, wherein the number and arrangement combination of the sensing units of the plurality of adjacent sensing units having the highest light intensity positive correlation compensation data are preset;
the method further comprises the following steps: if more than two regions reaching the light intensity threshold exist in the light intensity positive correlation compensation data, and the number of sensing units and the shape arrangement combination mode of the regions are the same as those of the preset regions, it is determined that scattered points appear, the regions are used as the positions, and the distance of the multi-target object is obtained in the step of obtaining the distance of the target object.
5. A ranging method as claimed in claim 3, characterized in that said light intensity threshold is a preset value depending on the measurement accuracy and/or the ambient light intensity.
6. The method of claim 1, wherein the locations are stripe-shaped segments.
7. The distance measuring method according to claim 1, wherein the step of determining the position of the sensing module irradiated by the probe light spot according to the light intensity positive correlation compensation data obtained by subtracting the second light intensity positive correlation data from the first light intensity positive correlation data of each sensing unit comprises:
counting the sum of the light intensity positive correlation compensation data of each induction partition of the sensing module according to the light intensity positive correlation compensation data; each sensing partition includes at least one sensing element.
8. The distance measuring method according to claim 7, wherein the step of turning on the sensing unit corresponding to the position to receive the probe light reflected by the target object comprises: and opening the induction subarea of which the sum of the light intensity positive correlation compensation data reaches the light intensity threshold value, and receiving the detection light reflected by the target object.
9. The method of claim 7, wherein the step of obtaining the target object distance according to the sensing signal received by the sensing unit comprises: and multiplying the amplitude of the sensing signal of each sensing subarea by the sum of the light intensity positive correlation compensation data to obtain the flight time, and obtaining the target object distance according to the flight time.
10. The distance measuring method according to claim 9, wherein the step of multiplying the sum of the amplitude of the sensing signal of each sensing segment and the light intensity positive correlation compensation data to obtain the flight time comprises:
acquiring a first histogram corresponding to the sensing signal;
obtaining data combination to form a second histogram after multiplying the sum of the amplitude and the light intensity positive correlation compensation data;
and obtaining the flight time according to the second histogram.
11. The method of claim 1, wherein the sensing module comprises an array of single photon avalanche diodes, each single photon avalanche diode being an inductive unit.
12. The distance measuring method according to claim 1, further comprising a step of writing the first light-intensity positive correlation data into a register and a step of writing the light-intensity positive correlation compensation data into a register; the second light-intensity positive correlation data is not written to the register.
13. The distance measuring method according to claim 1, wherein in the step of subtracting the second light intensity positive correlation data from the first light intensity positive correlation data of each sensing unit, the light intensity value of the sensing unit less than 0 after subtraction is recorded as 0 or a corresponding negative number.
14. The ranging method according to claim 1, wherein the step of obtaining the distance of the target object according to the sensing signal received by the sensing unit comprises: and obtaining the flight time by constructing a histogram corresponding to the sensing signal, and obtaining the target object distance according to the flight time.
15. The distance measuring method according to claim 1, wherein the exposure time of the step of acquiring the first light intensity positive correlation data of each sensing unit of the sensing module in a state where the light emitter emits the detection light is equal to the exposure time of the step of acquiring the second light intensity positive correlation data of each sensing unit of the sensing module in a state where the light emitter does not emit light.
16. A computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method of any one of claims 1-15.
17. A ranging system, comprising:
a light emitter;
the sensing module comprises a plurality of sensing units and a sensing unit, wherein the sensing units are used for receiving the detection light reflected by the target object;
the control module is used for controlling the emission and the closing of the light emitter so as to acquire first light intensity positive correlation data of each sensing unit of the sensing module in a state that the light emitter emits detection light and second light intensity positive correlation data of each sensing unit of the sensing module in a state that the light emitter does not emit light, and determining the position of a detection light spot irradiated on the sensing module according to light intensity positive correlation compensation data obtained by subtracting the second light intensity positive correlation data from the first light intensity positive correlation data of each sensing unit; the sensing units corresponding to the positions are opened to receive the detection light reflected by the target object, and the distance of the target object is obtained according to the sensing signals received by the sensing units;
wherein the first light intensity positive correlation data and the second light intensity positive correlation data are positively correlated with the light intensity sensed by each sensing unit.
18. The distance measuring system of claim 17, wherein the control module comprises a register, and the control module is configured to add one to a corresponding register value when each sensing unit is triggered once or receives one photon in a state where the light emitter emits the detection light, and further configured to subtract one from the corresponding register value when each sensing unit is triggered once or receives one photon in a state where the light emitter does not emit light, so as to obtain the light intensity positive correlation compensation data.
19. The distance measuring system of claim 17, wherein the control module comprises a weighting unit for counting the sum of the light intensity positive correlation compensation data of each sensing partition of the sensing module according to the light intensity positive correlation compensation data; the control module opens the position, including opening the sensing subarea where the sum of the light intensity positive correlation compensation data reaches a light intensity threshold; the control module obtains the distance of the target object according to the sensing signals received by the sensing units, and comprises the steps of multiplying the amplitude of the sensing signals of each sensing subarea by the sum of the light intensity positive correlation compensation data to obtain the flight time, and obtaining the distance according to the flight time;
wherein each sensing partition comprises at least one sensing unit.
20. The range finding system of claim 19, wherein the control module comprises a plurality of time-to-digital converters, and the control module multiplies the sum of the amplitude of the sensing signal and the light intensity positive correlation compensation data for each sensing segment to obtain the flight time, and comprises: and obtaining a first histogram corresponding to each induction zone through the time-to-digital converter, obtaining data combination to form a second histogram after multiplying the sum of the amplitude and the light intensity positive correlation compensation data, and obtaining the flight time according to the second histogram.
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