CN111736168A - Three-dimensional imaging laser radar and method based on unit single photon detector - Google Patents
Three-dimensional imaging laser radar and method based on unit single photon detector Download PDFInfo
- Publication number
- CN111736168A CN111736168A CN202010573801.2A CN202010573801A CN111736168A CN 111736168 A CN111736168 A CN 111736168A CN 202010573801 A CN202010573801 A CN 202010573801A CN 111736168 A CN111736168 A CN 111736168A
- Authority
- CN
- China
- Prior art keywords
- photon detector
- optical fiber
- time
- pulse laser
- fiber array
- 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.)
- Withdrawn
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
- G01S17/88—Lidar systems specially adapted for specific applications
- G01S17/89—Lidar systems specially adapted for specific applications for mapping or imaging
-
- 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 invention discloses a three-dimensional imaging laser radar and a method based on a unit single photon detector, and relates to the field of three-dimensional imaging. The laser radar includes: the laser emits pulse laser, the main wave detector records the emission time of the pulse laser according to the detected pulse laser, the optical emission system irradiates the other part of the pulse laser to a target object, the optical receiving system receives the pulse laser reflected by the target object and transmits the pulse laser to the optical fiber array single-photon detector, the optical fiber array single-photon detector detects the pulse laser reflected by the target object in a time-sharing mode to obtain the pixel coordinate of the target object and the receiving time of pixel echo, and the processor determines a distance matrix according to the emission time, the pixel coordinate and the receiving time, so that the non-scanning three-dimensional imaging of the target can be realized only by using the unit single-photon detector, the mutual interference between the adjacent unit detectors does not exist, the realization is easy, and the cost is low.
Description
Technical Field
The invention relates to the field of three-dimensional imaging, in particular to a three-dimensional imaging laser radar and a three-dimensional imaging laser radar method based on a unit single-photon detector.
Background
The three-dimensional imaging laser radar realizes three-dimensional imaging by acquiring the distance information of a target. The basic principle is to calculate the distance by measuring the time that a laser pulse travels to and from the radar to the target. In order to obtain the distance between different target points, a scanning mode or a non-scanning mode can be adopted. The array single-photon detector of the general laser radar is formed by arranging a plurality of unit single-photon detectors, and the detector has the defects that the response efficiency of each single-photon detector in the detector array is inconsistent, and the overall detection effect of the array is influenced. And the adjacent single-photon detectors have crosstalk, which affects the overall effect of array detection, and has high arrangement requirement, difficult realization and high cost.
Disclosure of Invention
The invention aims to solve the technical problem of the prior art and provides a three-dimensional imaging laser radar and a three-dimensional imaging laser radar method based on a unit single-photon detector.
The technical scheme for solving the technical problems is as follows:
a three-dimensional imaging laser radar based on a unit single photon detector comprises: the device comprises a laser, a main wave detector, an optical transmitting system, an optical receiving system, an optical fiber array single photon detector and a processor;
the laser is used for emitting pulse laser;
the main wave detector is used for recording the emission time of the pulse laser according to a part of the detected pulse laser;
the optical emission system is used for irradiating another part of the pulse laser to a target object;
the optical receiving system is used for receiving the pulse laser reflected by the target object and transmitting the pulse laser to the optical fiber array single-photon detector;
the optical fiber array single-photon detector is used for detecting the pulse laser reflected by the target object in a time-sharing manner to obtain a pixel coordinate and a pixel echo receiving time;
and the processor is used for determining a distance matrix according to the transmitting time, the pixel coordinates and the receiving time so as to obtain a three-dimensional image of the target object.
The invention has the beneficial effects that: the method comprises the steps that a laser emits pulse laser, a main wave detector records the emitting time of the pulse laser according to the detected laser, an optical emitting system irradiates the other part of the pulse laser to a target object, an optical receiving system receives the pulse laser reflected by the target object and transmits the pulse laser to an optical fiber array single-photon detector, the optical fiber array single-photon detector detects the reflected pulse laser in a time-sharing mode to obtain pixel coordinates of the target object and the receiving time of pixel echoes, and a processor determines a distance matrix according to the emitting time, the pixel coordinates and the receiving time to obtain a three-dimensional image of the target object; the laser radar comprises a laser, a main wave detector, an optical transmitting system, an optical receiving system, an optical fiber array single-photon detector and a processor, has compact structure, high imaging frame frequency and low requirement on laser pulse frequency, realizes non-scanning three-dimensional imaging of a target by only using the unit single-photon detector, has no mutual interference between the adjacent unit single-photon detectors, is easy to realize and has low cost.
Furthermore, the optical fiber array single-photon detector consists of an optical fiber array and a unit single-photon detector;
and the reference optical fiber and the time delay optical fiber of each pixel of the optical fiber array are combined into one optical fiber to be connected with the single photon detector.
The beneficial effect of adopting the further scheme is that: the optical fiber array single photon detector comprises an optical fiber array and a unit single photon detector, wherein a reference optical fiber and a time delay optical fiber of each pixel of the optical fiber array are combined into one optical fiber to be connected with the single photon detector.
Further, the distance matrix includes:
L(i，j)＝[T(2)(i，j)-T1]×c/2，
wherein, T1 represents the emitting time of the pulse laser, T (2) (i, j) represents the receiving time of the pixel echo, L (i, j) represents the distance corresponding to the pixel (i, j), i, j is the coordinate value of the pixel, c is the speed of light.
The beneficial effect of adopting the further scheme is that: according to the scheme, a distance matrix is determined according to the transmitting time, the pixel coordinates and the receiving time, and the distance values of all pixels are calculated according to the distance matrix to obtain a three-dimensional image of a target object.
Further, the optical fiber array is also used for separating two pulses by the optical fiber time delay for a time longer than a dead time when the two continuous pulses enter different optical fibers of the single photon detector of the optical fiber array.
The beneficial effect of adopting the further scheme is that: according to the scheme, when two continuous pulses enter different optical fibers of the optical fiber array single photon detector, the separation time of the two pulses is longer than the dead time through optical fiber time delay, so that the first pulse can be detected, and the second pulse can be normally detected.
Further, the optical fiber array is: an N x N type arrangement of optical fibers, a ring type arrangement of optical fibers, or a linear arrangement of optical fibers.
Another technical solution of the present invention for solving the above technical problems is as follows:
a three-dimensional imaging method based on a unit single photon detector comprises the following steps:
the laser emits pulse laser;
the main wave detector records the emission time of the pulse laser according to a part of the detected pulse laser;
the optical emission system irradiates another part of the pulse laser to a target object;
the optical receiving system receives the pulse laser reflected by the target object and transmits the pulse laser to the optical fiber array single-photon detector;
the optical fiber array single-photon detector detects the pulse laser reflected by the target object in a time-sharing manner to obtain a pixel coordinate of the target object and a receiving time of a pixel echo;
and the processor determines a distance matrix according to the transmitting time, the pixel coordinate and the receiving time so as to obtain a three-dimensional image of the target object.
The invention has the beneficial effects that: the laser emits pulse laser, the main wave detector records the emission time of the pulse laser according to a detected part of the pulse laser, the optical emission system irradiates another part of the pulse laser to a target object, the optical receiving system receives the pulse laser reflected by the target object and transmits the pulse laser to the optical fiber array single-photon detector, the optical fiber array single-photon detector detects the pulse laser reflected by the target object in a time-sharing manner to obtain pixel coordinates of the target object and the receiving time of pixel echoes, and the processor determines a distance matrix according to the emission time, the pixel coordinates and the receiving time so as to obtain a three-dimensional image of the target object; the laser radar comprises a laser, a main wave detector, an optical transmitting system, an optical receiving system, an optical fiber array single-photon detector and a processor, has compact structure, high imaging frame frequency and low requirement on laser pulse frequency, realizes non-scanning three-dimensional imaging of a target by only using the unit single-photon detector, has no mutual interference between the adjacent unit single-photon detectors, is easy to realize and has low cost.
Furthermore, the optical fiber array single-photon detector consists of an optical fiber array and a unit single-photon detector;
and the reference optical fiber and the time delay optical fiber of each pixel of the optical fiber array are combined into one optical fiber to be connected with the single photon detector.
The beneficial effect of adopting the further scheme is that: the optical fiber array single photon detector comprises an optical fiber array and a unit single photon detector, wherein a reference optical fiber and a time delay optical fiber of each pixel of the optical fiber array are combined into one optical fiber to be connected with the single photon detector.
Further, the distance matrix includes:
L(i，j)＝[T(2)(i，j)-T1]×c/2，
wherein, T1 represents the emitting time of the pulse laser, T (2) (i, j) represents the receiving time of the pixel echo, L (i, j) represents the distance corresponding to the pixel (i, j), i.e. the distance matrix, i, j are the coordinate values of the pixel, c is the speed of light.
The beneficial effect of adopting the further scheme is that: according to the scheme, a distance matrix is determined according to the transmitting time, the pixel coordinates and the receiving time, and the distance values of all pixels are calculated according to the distance matrix to obtain a three-dimensional image of a target object.
Further, still include: and when two continuous pulses enter different optical fibers of the optical fiber array single photon detector, the separation time of the two pulses is longer than the dead time through optical fiber time delay.
The beneficial effect of adopting the further scheme is that: according to the scheme, when two continuous pulses enter different optical fibers of the optical fiber array single photon detector, the separation time of the two pulses is longer than the dead time through optical fiber time delay, so that the first pulse can be detected, and the second pulse can be normally detected.
Further, the optical fiber array is: an N x N type arrangement of optical fibers, a ring type arrangement of optical fibers, or a linear arrangement of optical fibers.
Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
Fig. 1 is a structural block diagram of a three-dimensional imaging laser radar based on a unit single-photon detector according to an embodiment of the present invention;
FIG. 2 is a schematic flow chart of a three-dimensional imaging method based on a single-photon detector unit according to another embodiment of the present invention;
fig. 3 is an overall structural diagram of a laser radar according to another embodiment of the present invention;
FIG. 4 is a connection diagram of a fiber array and a single photon detector unit according to another embodiment of the present invention;
FIG. 5 is a graph of fiber array single photon detector lidar simulation data for other embodiments of the present invention;
fig. 6 is a schematic diagram of an optical fiber array in a ring arrangement according to an embodiment of the present invention.
Detailed Description
The principles and features of this invention are described below in conjunction with the following drawings, which are set forth to illustrate, but are not to be construed to limit the scope of the invention.
As shown in fig. 1, a three-dimensional imaging lidar based on a single-photon unit detector provided in an embodiment of the present invention includes: a three-dimensional imaging laser radar based on a unit single photon detector comprises: the system comprises a laser 110, a main wave detector 130, an optical emission system 120, an optical receiving system 140, a fiber array single photon detector 150 and a processor 160; the main wave detector 130 is used for detecting laser pulses, and may employ a photoelectric detector; and a processor 160 for performing image processing according to the acquired data points of the target object to obtain a model of the target object, wherein the calculation process can be performed in a computer according to the existing image processing method.
The laser 110 is used to emit pulsed laser light;
the main wave detector 130 is configured to record an emission time of the pulse laser according to a detected portion of the pulse laser;
the optical emission system 120 is used to irradiate another part of the pulsed laser onto the target object;
the optical receiving system 140 is used for receiving the pulse laser reflected by the target object and transmitting the pulse laser to the fiber array single photon detector 150;
the optical fiber array single-photon detector 150 is used for detecting pulse laser reflected by a target object in a time-sharing manner to obtain a pixel coordinate and a pixel echo receiving time;
it should be noted that the fiber array single photon detector 150 is composed of a fiber array and a unit single photon detector; the single-photon detector is a detector capable of realizing single-photon detection, and is generally APD and SNSPD. Single photon detectors can be divided into: single-photon detectors of the cell (or single) type and arrays.
The general array single photon detector is formed by arranging a plurality of unit single photon detectors, and has the following defects: the response efficiency of each single photon detector in the array is inconsistent, so that the overall detection effect of the array is influenced; crosstalk exists between adjacent single-photon detectors, and the overall detection effect of the array is influenced; the arrangement requirement is high, the realization is difficult, and the cost is high, and the scheme can well solve the defects through the optical fiber array single-photon detector 150 consisting of the optical fiber array and a unit single-photon detector.
Processor 160 is configured to determine a distance matrix based on the transmit time, pixel coordinates, and receive time to obtain a three-dimensional image of the target object. In one embodiment, the present invention is a non-scanning lidar, and the processor 160 is configured to calculate an expression of L (i, j) ═ T (2) (i, j) -T1] × c/2 and obtain a three-dimensional image, which can be implemented by a computer. Where T1 is given by the main detector 130 and T (2) (i, j) is given by the fiber array single photon detector 150.
To illustrate, in one embodiment, as shown in FIG. 3, laser 110 emits a pulsed laser, a small portion of which is detected to record the emission time T1, and a large portion of which is directed through the emission system to the target. A portion of the laser light reflected by the target is received by the receive optical system and delivered to the fiber array at the imaging plane. The optical fiber array is connected with the single photon detector, and the coordinates of the pixel are (i, j) and the pixel echo receiving time T2(i, j) can be obtained through time-sharing detection, so that a distance matrix L (i, j) [ T (2) (i, j) -T1] × c/2 can be determined, wherein i, j are the coordinates of the pixel, and c is the speed of light.
According to the scheme, a laser 110 emits pulse laser, a main wave detector 130 records the emission time of the pulse laser according to a detected part of the pulse laser, an optical emission system 120 irradiates another part of the pulse laser to a target object, an optical receiving system 140 receives the pulse laser reflected by the target object and transmits the pulse laser to an optical fiber array single-photon detector 150, the optical fiber array single-photon detector 150 detects the pulse laser reflected by the target object in a time-sharing manner to obtain a pixel coordinate of the target object and a receiving time of a pixel echo, and a processor 160 determines a distance matrix according to the emission time, the pixel coordinate and the receiving time, so that a three-dimensional image of the target object is obtained; the laser radar comprising the laser 110, the main wave detector 130, the optical emission system 120, the optical receiving system 140, the fiber array single-photon detector 150 and the processor 160 has the advantages of compact structure, high imaging frame frequency and low requirement on laser pulse frequency, realizes non-scanning three-dimensional imaging of a target by only using the unit single-photon detector, does not have mutual interference between the adjacent unit single-photon detectors, and is easy to realize and low in cost.
Preferably, in any of the above embodiments, the fiber array single photon detector 150 is composed of a fiber array and a single unit single photon detector;
the reference optical fiber and the time delay optical fiber of each pixel of the optical fiber array are combined into one optical fiber to be connected with the single photon detector.
It should be noted that, in an embodiment, a connection manner between the optical fiber array and the single photon detector is, as shown in fig. 4, taking a 4 × 4 optical fiber array as an example, where each pixel corresponds to an end face of an optical fiber. Each pixel element is split into a reference optical fiber and a time delay optical fiber, and the reference optical fibers have the same length and are lb. The time delay optical fiber of the first pixel is longer than the reference optical fiber by delta l, the time delay optical fibers of the other pixels are increased by delta l one by one according to the position number, namely the time delay optical fiber of the nth pixel is lb + n multiplied by delta l. And finally, combining all the reference optical fibers and the time delay optical fibers into one optical fiber to be connected with the single photon detector. The connection modes of the No. 4, No. 8, No. 12 and No. 16 optical fibers and echo signals are illustrated in FIG. 2. It can be seen that the echo signals are also in the form of pulses, the time offset of the pulses indicates that the target distances corresponding to the image elements are different, and the height difference indicates that the echo intensities of the image elements are different. After the signals are converged to the same optical fiber through optical fibers with different lengths, an obvious pulse sequence is formed and sequentially enters the unit single-photon detector. The first single photon detection in the unit is the echo transmitted through a reference optical fiber. With the detector accurately detecting this pulse sequence and giving the detection instant T2(i, j) of each pulse, the distance matrix can be rewritten as:
L(i，j)＝[T(2)(i，j)-T1-DF(i，j)]×c/2，
wherein, T1 represents the laser emission time, (i, j) represents the coordinates of the pixel corresponding to the pulse, DF (i, j) is the delay of the corresponding delay fiber, and c is the speed of light.
For the reference fiber, lb should be reduced to minimize loss under the conditions that will be satisfied for the installation. Δ l should be long enough to ensure that the optical line time is greater than the detector dead time, which can be accurately measured experimentally.
It should be noted that the operation modes of the single photon detector may include: 1. waiting for photons, 2 photon excitation, 3 recovery (without single photon detection capability), 4 waiting for photons, and the processes are circulated. Where the dead time is the time required from waiting for a photon to recover.
The optical fiber array single photon detector 150 comprises an optical fiber array and a unit single photon detector, wherein a reference optical fiber and a time delay optical fiber of each pixel of the optical fiber array are combined into one optical fiber to be connected with the single photon detector.
Preferably, in any of the above embodiments, the distance matrix comprises:
L(i，j)＝[T(2)(i，j)-T1]×c/2，
wherein, T1 represents the emitting time of the pulse laser, T (2) (i, j) represents the receiving time of the pixel echo, L (i, j) represents the distance corresponding to the pixel (i, j), i.e. the distance matrix, i, j are the coordinate values of the pixel, c is the speed of light.
According to the scheme, a distance matrix is determined according to the transmitting time, the pixel coordinates and the receiving time, and the distance values of all pixels are calculated according to the distance matrix to obtain a three-dimensional image of a target object.
Preferably, in any of the above embodiments, the fiber array is further configured to separate the two pulses by a time delay of the fiber when the two consecutive pulses enter different fibers of the fiber array single photon detector 150, so that the fiber array single photon detector 150 detects the second pulse of the two consecutive pulses.
It should be noted that, for a single photon detector (e.g. APD, SNSPD), when the detector is triggered, it needs at least one dead time to recover the detection capability, if two consecutive pulses enter the detector, the second pulse cannot be detected because the first pulse excites the detector, and when the two pulses are separated by the fiber delay time longer than the dead time, the detector can normally detect the second pulse.
When two continuous pulses enter the fiber array single-photon detector 150, the separation time of the two pulses is longer than the dead time through the fiber delay, so that the first pulse can be detected, and the second pulse can be normally detected.
Preferably, in any of the above embodiments, the optical fiber array is: an N x N array, a circular array, or a linear array, etc. Wherein, the arrangement mode of the array in the ring-shaped arrangement is shown in fig. 6; the end faces of the optical fibers are uniformly distributed on the circumference of a concentric circle to form an array in annular arrangement.
Wherein, the optical fiber array specifically includes: the system comprises a plurality of pixel points, a plurality of optical fiber units and a plurality of optical fiber units, wherein each pixel point comprises a reference optical fiber and a time delay optical fiber; the lengths of the reference optical fibers of all the pixel points are consistent, and the time delay optical fibers are distributed according to the length equal difference.
In one embodiment, the radar data of the fiber array single photon detector 150 lidar is simulated, as shown in fig. 5, where a is the raw data and b is the data after noise filtering. One point in the data, representing the response of a detector, the abscissa of the point represents the moment of laser emission, and the ordinate of the point represents the difference between the moment of response and the moment of laser emission: T2-T1. The earlier it is fired for the same pulse, the lower the data points in the plot. The detector responds more intensively, indicating more incident light, and can be judged as a signal. It can also be seen that the non-signal areas also respond, which is either non-signal light excitation or detector heat source dark counts. Since the delay of the reference fiber is the shortest, the lowermost signal line is the echo signal transmitted through the reference fiber. And the light line corresponding to the delta l is delayed by delta T, and then the reference lines corresponding to the pixels can be found by sequentially moving the delta T upwards on the basis of the reference echo signal line. The echo signal near the reference line is the echo of the corresponding pixel. The detection time T2(i, j) of the echo signal is substituted into the formula distance matrix formula, and the distance array, i.e. the 3D target image, can be obtained. The data presented in fig. 5 is the result of a 4 x 4 array lidar measurement for a moving cone, looking down. In the whole measuring process, when a cone moves to a corresponding pixel, an obvious echo signal appears near a reference line of the pixel, if the pixel corresponds to the top of the cone, the signal line is arranged below, if the pixel corresponds to the edge of the cone, the signal line is arranged above, and if the pixel does not correspond to the cone, no effective signal exists near the reference line. It can also be seen that the lowermost reference signal line is very visible throughout the movement of the cone. This is because the length of the reference line of each pixel is the same, and as long as the target appears in the field of view of the detector and any one pixel has an echo signal, the reference line will have a response. This feature ensures that the earliest appearing signal in the data, i.e., the lowest data line in the figure, must be the reference signal. This provides the possibility to locate the echo of each picture element in a plurality of data lines.
In one embodiment, as shown in fig. 2, a three-dimensional imaging method based on a single-photon detector includes: the laser 110 emits pulsed laser light;
the main wave detector 130 records the emission time of the pulse laser according to a part of the detected pulse laser;
the optical emission system 120 irradiates another portion of the pulsed laser onto the target object;
the optical receiving system 140 receives the pulse laser reflected by the target object and transmits the pulse laser to the fiber array single-photon detector 150;
the fiber array single-photon detector 150 detects pulse laser reflected by the target object in a time-sharing manner to obtain pixel coordinates of the target object and the receiving time of a pixel echo;
processor 160 determines the distance matrix based on the transmit time, pixel coordinates, and receive time to obtain a three-dimensional image of the target object.
According to the scheme, a laser 110 emits pulse laser, a main wave detector 130 records the emission time of the pulse laser according to a detected part of the pulse laser, an optical emission system 120 irradiates another part of the pulse laser to a target object, an optical receiving system 140 receives the pulse laser reflected by the target object and transmits the pulse laser to an optical fiber array single-photon detector 150, the optical fiber array single-photon detector 150 detects the pulse laser reflected by the target object in a time-sharing manner to obtain a pixel coordinate of the target object and a receiving time of a pixel echo, and a processor 160 determines a distance matrix according to the emission time, the pixel coordinate and the receiving time, so that a three-dimensional image of the target object is obtained; the laser radar comprising the laser 110, the main wave detector 130, the optical emission system 120, the optical receiving system 140, the fiber array single-photon detector 150 and the processor 160 has the advantages of compact structure, high imaging frame frequency and low requirement on laser pulse frequency, realizes non-scanning three-dimensional imaging of a target by only using the unit single-photon detector, does not have mutual interference between the adjacent unit single-photon detectors, and is easy to realize and low in cost.
Preferably, in any of the above embodiments, the fiber array single photon detector 150 is composed of a fiber array and a single unit single photon detector;
the reference optical fiber and the time delay optical fiber of each pixel of the optical fiber array are combined into one optical fiber to be connected with the single photon detector.
The optical fiber array single photon detector 150 comprises an optical fiber array and a unit single photon detector, wherein a reference optical fiber and a time delay optical fiber of each pixel of the optical fiber array are combined into one optical fiber to be connected with the single photon detector.
Preferably, in any of the above embodiments, the distance matrix comprises:
L(i，j)＝[T(2)(i，j)-T1]×c/2，
wherein, T1 represents the emitting time of the pulse laser, T (2) (i, j) represents the receiving time of the pixel echo, L (i, j) represents the distance corresponding to the pixel (i, j), i.e. the distance matrix, i, j are the coordinate values of the pixel, c is the speed of light.
According to the scheme, a distance matrix is determined according to the transmitting time, the pixel coordinates and the receiving time, and the distance values of all pixels are calculated according to the distance matrix to obtain a three-dimensional image of a target object.
Preferably, in any of the above embodiments, when two consecutive pulses enter different fibers of the fiber array single photon detector 150, the two pulses are separated by a fiber delay time longer than a dead time, so that the fiber array single photon detector 150 detects the second pulse of the two consecutive pulses.
When two continuous pulses enter different optical fibers of the optical fiber array single-photon detector 150, the separation time of the two pulses is longer than the dead time through optical fiber time delay, so that the first pulse can be detected, and the second pulse can also be normally detected.
Preferably, in any of the above embodiments, the optical fiber array is: an N x N type arrangement of optical fibers, a ring type arrangement of optical fibers, or a linear arrangement of optical fibers.
It is understood that some or all of the alternative embodiments described above may be included in some embodiments.
It should be noted that the above embodiments are product embodiments corresponding to the previous method embodiments, and for the description of each optional implementation in the product embodiments, reference may be made to corresponding descriptions in the above method embodiments, and details are not described here again.
The reader should understand that in the description of this specification, reference to the description of the terms "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
In the several embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the above-described method embodiments are merely illustrative, and for example, the division of steps into only one logical functional division may be implemented in practice in another way, for example, multiple steps may be combined or integrated into another step, or some features may be omitted, or not implemented.
The above method, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention essentially or partially contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-only memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.
While the invention has been described with reference to specific embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (10)
1. A three-dimensional imaging laser radar based on a unit single photon detector is characterized by comprising: the device comprises a laser, a main wave detector, an optical transmitting system, an optical receiving system, an optical fiber array single photon detector and a processor;
the laser is used for emitting pulse laser;
the main wave detector is used for recording the emission time of the pulse laser according to a part of the detected pulse laser;
the optical emission system is used for irradiating another part of the pulse laser to a target object;
the optical receiving system is used for receiving the pulse laser reflected by the target object and transmitting the pulse laser to the optical fiber array single-photon detector;
the optical fiber array single-photon detector is used for detecting the pulse laser reflected by the target object according to time sharing to obtain a pixel coordinate and a pixel echo receiving time;
and the processor is used for determining a distance matrix according to the transmitting time, the pixel coordinates and the receiving time so as to obtain a three-dimensional image of the target object.
2. The three-dimensional imaging lidar based on a unit single-photon detector as claimed in claim 1, characterized in that the fiber array single-photon detector is composed of a fiber array and a unit single-photon detector;
and the reference optical fiber and the time delay optical fiber of each pixel of the optical fiber array are combined into one optical fiber to be connected with the single photon detector.
3. The three-dimensional imaging lidar based on a single photon detector unit according to claim 1 or 2, wherein the distance matrix comprises:
L(i，j)＝[T(2)(i，j)-T1]×c/2，
wherein, T1 represents the emitting time of the pulse laser, T (2) (i, j) represents the receiving time of the pixel echo, L (i, j) represents the distance corresponding to the pixel (i, j), i.e. the distance matrix, i, j are the coordinate values of the pixel, c is the speed of light.
4. The three-dimensional imaging lidar based on a unit single photon detector as claimed in claim 1 or 2, wherein the fiber array is further configured to separate two pulses by a fiber delay time for a time greater than a dead time when the two pulses enter different fibers of the single photon detector of the fiber array.
5. The three-dimensional imaging laser radar based on the unit single photon detector as claimed in claim 4, wherein the optical fiber array is: an N x N type arrangement of optical fibers, a ring type arrangement of optical fibers, or a linear arrangement of optical fibers.
6. A three-dimensional imaging method based on a unit single photon detector is characterized by comprising the following steps:
the laser emits pulse laser;
the main wave detector records the emission time of the pulse laser according to a part of the detected pulse laser;
the optical emission system irradiates another part of the pulse laser to a target object;
the optical receiving system receives the pulse laser reflected by the target object and transmits the pulse laser to the optical fiber array single-photon detector;
the optical fiber array single-photon detector detects the pulse laser reflected by the target object in a time-sharing manner to obtain a pixel coordinate of the target object and a receiving time of a pixel echo;
and the processor determines a distance matrix according to the transmitting time, the pixel coordinate and the receiving time so as to obtain a three-dimensional image of the target object.
7. The method of claim 6 in which the single photon detector of optical fiber array is composed of an optical fiber array and a single photon detector of unit;
and the reference optical fiber and the time delay optical fiber of each pixel of the optical fiber array are combined into one optical fiber to be connected with the single photon detector.
8. The method of three-dimensional imaging based on single photon detectors of claim 6 or 7, characterized in that said distance matrix comprises:
L(i，j)＝[T(2)(i，j)-T1]×c/2，
wherein, T1 represents the emitting time of the pulse laser, T (2) (i, j) represents the receiving time of the pixel echo, L (i, j) represents the distance corresponding to the pixel (i, j), i.e. the distance matrix, i, j are the coordinate values of the pixel, c is the speed of light.
9. The method for three-dimensional imaging based on single photon detector of claim 6 or 7, further comprising: and when two continuous pulses enter different optical fibers of the optical fiber array single photon detector, the separation time of the two pulses is longer than the dead time through optical fiber time delay.
10. The three-dimensional imaging method based on the unit single photon detector as claimed in claim 9, wherein the optical fiber array is: an N x N type arrangement of optical fibers, a ring type arrangement of optical fibers, or a linear arrangement of optical fibers.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010573801.2A CN111736168A (en) | 2020-06-22 | 2020-06-22 | Three-dimensional imaging laser radar and method based on unit single photon detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010573801.2A CN111736168A (en) | 2020-06-22 | 2020-06-22 | Three-dimensional imaging laser radar and method based on unit single photon detector |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111736168A true CN111736168A (en) | 2020-10-02 |
Family
ID=72650376
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010573801.2A Withdrawn CN111736168A (en) | 2020-06-22 | 2020-06-22 | Three-dimensional imaging laser radar and method based on unit single photon detector |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111736168A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112731443A (en) * | 2021-02-08 | 2021-04-30 | 山东大学 | Three-dimensional imaging system and method for fusing single photon laser radar and short wave infrared image |
| CN113391461A (en) * | 2021-06-30 | 2021-09-14 | 宁波Gqy视讯股份有限公司 | Imaging method and system |
-
2020
- 2020-06-22 CN CN202010573801.2A patent/CN111736168A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112731443A (en) * | 2021-02-08 | 2021-04-30 | 山东大学 | Three-dimensional imaging system and method for fusing single photon laser radar and short wave infrared image |
| CN113391461A (en) * | 2021-06-30 | 2021-09-14 | 宁波Gqy视讯股份有限公司 | Imaging method and system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111465870B (en) | Time-of-flight sensing using an array of addressable emitters | |
| CN105043539B (en) | Method and apparatus for running photodetector | |
| CN111727381B (en) | Multi-pulse LiDAR system for multi-dimensional sensing of objects | |
| US7115875B1 (en) | PET scanner with photodetectors and wavelength shifting fibers | |
| US20220035011A1 (en) | Temporal jitter in a lidar system | |
| CN111736168A (en) | Three-dimensional imaging laser radar and method based on unit single photon detector | |
| CN109814128B (en) | High-resolution rapid imaging system and method combining time flight and associated imaging | |
| WO2019226487A1 (en) | Parallel photon counting | |
| CN111971577A (en) | Method for controlling a sensor element of a lidar measurement system | |
| CN112470026A (en) | Laser radar, detection method thereof, storage medium and detection system | |
| US20220221584A1 (en) | Laser radar and method for generating laser point could data | |
| CN112394362B (en) | Multi-line scanning distance measuring method and system | |
| CN107643272B (en) | Time-resolved fluorescence measurement system based on few-channel TCSPC and multi-detector | |
| CN116203543A (en) | Method and system for evaluating detection performance of SiPM output discrimination threshold on laser radar system | |
| CN113126064A (en) | Signal processing method and related device | |
| CN112799032B (en) | Method and system for preventing inter-channel crosstalk of laser radar and electronic equipment | |
| US20230194666A1 (en) | Object Reflectivity Estimation in a LIDAR System | |
| CN114365007A (en) | Method for measuring distance to target | |
| WO2022141468A1 (en) | Detection method for laser radar, computer readable storage medium, and laser radar | |
| CN115902836A (en) | Laser radar control method and device, control chip and laser radar | |
| CN114325646A (en) | Remote photon laser radar scanning method and system thereof | |
| JP2023542627A (en) | Systems and methods for crystal-channel coupling | |
| EP4198569A1 (en) | Lidar device, system and method | |
| JPWO2021067165A5 (en) | ||
| WO2023133965A1 (en) | Laser radar system and ambient light sensing method therefor |
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 | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20201002 |
|
| WW01 | Invention patent application withdrawn after publication |