CN114924252B - Abnormal echo signal identification method, device, equipment and storage medium - Google Patents

Abnormal echo signal identification method, device, equipment and storage medium Download PDF

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CN114924252B
CN114924252B CN202210866104.5A CN202210866104A CN114924252B CN 114924252 B CN114924252 B CN 114924252B CN 202210866104 A CN202210866104 A CN 202210866104A CN 114924252 B CN114924252 B CN 114924252B
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signal
pulse width
value
determining
echo
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CN114924252A (en
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赵拓
舒博正
王思拨
夏冰冰
石拓
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Suzhou Yijing Technology Co ltd
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Suzhou Yijing Technology Co ltd
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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
    • G01S7/4802—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00 using analysis of echo signal for target characterisation; Target signature; Target cross-section
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
    • Y02A90/10—Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

The application discloses a method, a device and equipment for identifying abnormal echo signals and a storage medium. The identification method comprises the following steps: obtaining a first echo signal of the laser radar; determining the first echo signal as a non-saturated signal; determining a first signal-to-noise ratio of the first echo signal; determining a first pulse width upper limit value according to the first signal-to-noise ratio; and when the first pulse width value of the first echo signal is greater than the first pulse width upper limit value, identifying the first echo signal as an abnormal echo signal, wherein the abnormal echo signal is an echo signal with signal superposition. In the present application, an abnormal echo signal caused by signal superposition is identified by comparing a pulse width value of the echo signal with a corresponding pulse width upper limit value.

Description

Abnormal echo signal identification method, device, equipment and storage medium
Technical Field
The present application relates to the field of laser radar technologies, and in particular, to a method, an apparatus, a device, and a storage medium for identifying an abnormal echo signal.
Background
Lidar is a target detection technology. The laser is used as a signal light source, and the laser is emitted to a target object, so that a reflection signal of the target object is collected, and information such as the direction and the speed of the target object is obtained. The laser radar has the advantages of high measurement precision, strong anti-interference capability and the like, and is widely applied to the fields of remote sensing, measurement, intelligent driving, robots and the like.
Currently, there may be a portion of the laser beam emitted by the lidar that impinges on one object and another portion that impinges on another object. When the distance between two objects is too small, the time when the echo signals reflected by the two objects reach the laser radar is very close, so that the echo signals are overlapped, the phenomenon of tailing or wire drawing can occur between the point clouds of the two objects, and the boundary between the two point clouds is unclear.
Therefore, how to identify the abnormal echo signals with signal overlapping is an urgent problem to be solved.
Disclosure of Invention
The application provides a method, a device, equipment and a storage medium for identifying abnormal echo signals, which are used for identifying the abnormal echo signals with signal overlapping.
In a first aspect, the present application provides a method for identifying an abnormal echo signal. The method can be applied to an electronic device which can be a stand-alone device or integrated with a laser radar. The method comprises the following steps: obtaining a first echo signal of the laser radar; determining the first echo signal as a non-saturated signal; determining a first signal-to-noise ratio of the first echo signal; determining a first pulse width upper limit value according to the first signal-to-noise ratio; and when the first pulse width value of the first echo signal is greater than the first pulse width upper limit value, identifying the first echo signal as an abnormal echo signal, wherein the abnormal echo signal is an echo signal with signal superposition.
In some possible embodiments, the operation of determining the first upper limit value of the pulse width of the first echo signal may include: determining a first pulse width standard deviation value corresponding to a first signal-to-noise ratio value of the first echo signal according to a first mapping relation between the signal-to-noise ratio and the pulse width standard deviation; a first upper pulse width limit is determined based at least on the first standard pulse width difference.
In some possible embodiments, the method may further include: obtaining a plurality of second echo signals, wherein the plurality of second echo signals are a plurality of unsaturated signals without signal superposition; determining pulse width standard difference values corresponding to different signal-to-noise ratio intervals, wherein the signal-to-noise ratio intervals are obtained by dividing according to the value ranges of the signal-to-noise ratios corresponding to the second echo signals; and fitting the different signal-to-noise ratio intervals and the pulse width standard difference values to obtain a first mapping relation.
In some possible embodiments, the operation of determining the first upper limit value of the pulse width at least according to the first standard deviation value of the pulse width may include: determining a target coefficient corresponding to the first signal-to-noise ratio according to the detection probability of the laser radar and the first pulse width standard difference; and determining a first pulse width upper limit value according to the target coefficient, the reference pulse width value and the first pulse width standard difference value.
In some possible embodiments, the operation of determining the first upper limit value of the pulse width of the first echo signal may include: and determining a first pulse width upper limit value corresponding to a first signal-to-noise ratio value of the first echo signal according to a second mapping relation between the signal-to-noise ratio and the pulse width upper limit.
In some possible embodiments, the method may further include: obtaining a plurality of second echo signals, wherein the plurality of second echo signals are a plurality of unsaturated signals without signal superposition; determining pulse width standard difference values corresponding to different signal-to-noise ratio intervals, wherein the signal-to-noise ratio intervals are obtained by dividing the value ranges of the signal-to-noise ratio values corresponding to the second echo signals; determining the upper limit values of the pulse widths corresponding to different signal-to-noise ratio intervals at least according to the standard difference value of the pulse widths; and fitting the signal-to-noise ratio value and the pulse width upper limit value to obtain a second mapping relation.
In some possible embodiments, the operation of determining the upper limit values of the pulse widths corresponding to the different signal-to-noise ratio intervals according to at least the standard deviation value of the pulse widths may include: determining a target coefficient corresponding to a signal-to-noise ratio interval according to the detection probability of the laser radar and the pulse width standard difference value; and determining the upper limit value of the pulse width according to the target coefficient, the reference pulse width value and the pulse width standard difference value.
In some possible embodiments, the operation of determining the standard deviation values of the pulse widths corresponding to the different signal-to-noise ratio intervals may include: determining second signal-to-noise values corresponding to the second echo signals and second pulse width values of the second echo signals; and determining the standard deviation value of the pulse width according to the second pulse width value.
In a second aspect, the present application provides an apparatus for identifying an abnormal echo signal. The identification means may be an electronic device or a chip or a system on a chip in an electronic device, or may also be a functional module in an electronic device for implementing the method according to the first aspect and any possible implementation manner thereof. The identification means may implement the functions performed by the electronic device in the first aspect and any possible implementation manner thereof, and these functions may be implemented by hardware executing corresponding software. These hardware or software include one or more functionally corresponding modules. The above-mentioned identification means includes: the acquisition module is used for acquiring a first echo signal of the laser radar; the determining module is used for determining that the first echo signal is a non-saturated signal, determining a first signal-to-noise ratio of the first echo signal, and determining a first pulse width upper limit value according to the first signal-to-noise ratio; the identification module is used for identifying the first echo signal as an abnormal echo signal when the first pulse width value of the first echo signal is greater than the first pulse width upper limit value, wherein the abnormal echo signal is an echo signal with signal superposition.
In some possible implementations, the determining module may be to: determining a first pulse width standard deviation value corresponding to a first signal-to-noise ratio value of the first echo signal according to a first mapping relation between the signal-to-noise ratio and the pulse width standard deviation; a first upper pulse width limit is determined based at least on the first standard pulse width difference.
In some possible implementations, the obtaining module may be further configured to: a plurality of second echo signals are obtained, the plurality of second echo signals being a plurality of non-saturated signals without signal superposition. The determination module may be further operable to: and determining pulse width standard difference values corresponding to different signal-to-noise ratio intervals, wherein the signal-to-noise ratio intervals are obtained by dividing according to the value ranges of the signal-to-noise ratios corresponding to the second echo signals. The above apparatus may further include: and the calculation module is used for fitting different signal-to-noise ratio intervals and the pulse width standard difference value to obtain a first mapping relation.
In some possible implementations, the determining module may be to: determining a target coefficient corresponding to the first signal-to-noise ratio according to the detection probability of the laser radar and the first pulse width standard difference; and determining a first pulse width upper limit value according to the target coefficient, the reference pulse width value and the first pulse width standard difference value.
In some possible implementations, the determining module may be to: and determining a first pulse width upper limit value corresponding to a first signal-to-noise ratio of the first echo signal according to a second mapping relation between the signal-to-noise ratio and the pulse width upper limit.
In some possible implementations, the obtaining module may be further configured to: a plurality of second echo signals are obtained, the plurality of second echo signals being a plurality of non-saturated signals without signal superposition. The determination module may be further operable to: determining pulse width standard difference values corresponding to different signal-to-noise ratio intervals, wherein the signal-to-noise ratio intervals are obtained by dividing according to the value ranges of the signal-to-noise ratios corresponding to the second echo signals; and determining the upper limit value of the pulse width corresponding to the different signal-to-noise ratio intervals at least according to the standard difference value of the pulse width. The above apparatus may further include: and the calculating module is used for fitting the signal-to-noise ratio value and the pulse width upper limit value to obtain a second mapping relation.
In some possible implementations, the determining module may be to: determining a target coefficient corresponding to a signal-to-noise ratio interval according to the detection probability of the laser radar and the pulse width standard difference value; and determining the upper limit value of the pulse width according to the target coefficient, the reference pulse width value and the pulse width standard difference value.
In some possible implementations, the determining module may be to: determining second signal-to-noise values corresponding to the second echo signals and second pulse width values of the second echo signals; and determining a pulse width standard deviation value according to the second pulse width value.
In a third aspect, the present application provides an electronic device, comprising: a memory storing computer-executable instructions; a processor coupled to the memory for executing the computer-executable instructions to implement the method according to the first aspect and any possible implementation manner thereof.
In a fourth aspect, the present application provides a computer storage medium storing computer-executable instructions that, when executed by a processor, are capable of implementing the method according to the first aspect and any possible implementation manner thereof.
The technical scheme provided by the application can comprise the following beneficial effects:
in the application, for a non-saturated echo signal received by a laser radar, the pulse width value of the echo signal is compared with the pulse width upper limit value corresponding to the signal-to-noise ratio of the echo signal, so that whether signal superposition exists in the echo signal or not is identified, that is, whether the echo signal is an abnormal echo signal or not is identified.
Furthermore, the identification of the abnormal signal in the application can be only based on the signal-to-noise ratio value and the pulse width value of the echo signal, and the hardware circuit does not need to be changed, so that the workload on circuit design caused by the change of the hardware circuit is avoided.
Further, the identification of the abnormal signal in the present application is based on the pulse width of the echo signal, and the pulse width of the unsaturated signal is easily obtained, so the method for identifying the abnormal signal in the present application can be applied to most unsaturated signals.
Furthermore, the abnormal signal identification method can be carried out by utilizing process data generated by the echo signal in the general signal processing process without image processing, thereby greatly reducing the complexity of abnormal signal identification, shortening the time and improving the robustness.
Furthermore, in the application, the signal-to-noise ratio of the echo signal is associated with the pulse width of the echo signal, and different pulse width upper limit values can be obtained for the echo signals with different signal-to-noise ratios, so that the interference of the change of the signal-to-noise ratio on the identification of the abnormal signal can be avoided, and the identification accuracy is improved.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.
Drawings
Fig. 1 is a schematic structural diagram of a lidar in the related art;
fig. 2 is a schematic diagram of a laser radar detection scenario in an embodiment of the present application;
fig. 3 is a schematic diagram showing a relationship between the intensity and the waveform of an echo signal of the laser radar in the embodiment of the present application;
fig. 4 is a schematic flow chart illustrating an implementation of a method for identifying an abnormal echo signal in an embodiment of the present application;
fig. 5 is a schematic diagram of a linear interpolation process of a first echo signal in an embodiment of the present application;
fig. 6 is a schematic implementation flow diagram of establishing a first mapping relationship in the embodiment of the present application;
fig. 7 is a schematic implementation flow chart of establishing a second mapping relationship in the embodiment of the present application;
fig. 8 is a schematic structural diagram of an apparatus for identifying an abnormal echo signal in an embodiment of the present application;
fig. 9 is a schematic structural diagram of an electronic device in an embodiment of the present application.
Detailed Description
In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular system structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the invention herein. It will be apparent, however, to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.
In order to explain the technical means described in the present application, the following description will be given by way of specific examples.
Lidar is a target detection technology. The laser radar emits laser beams through the laser, the laser beams are subjected to diffuse reflection after encountering a target object, the reflected beams are received through the detector, and characteristic quantities such as the distance, the direction, the height, the speed, the posture and the shape of the target object are determined according to the emitted beams and the reflected beams.
The application field of the laser radar is very wide. In addition to military applications, it is now widely used in the field of life, including but not limited to: the field of intelligent piloted vehicles, intelligent piloted aircraft, three-dimensional (3D) printing, virtual reality, augmented reality, service robots, and the like. Taking the intelligent driving technology as an example, a laser radar is arranged in an intelligent driving vehicle, and the laser radar can scan the surrounding environment by rapidly and repeatedly emitting laser beams to acquire point cloud data and the like reflecting the appearance, position and motion of one or more target objects in the surrounding environment.
The intelligent driving technology may refer to technologies such as unmanned driving, automatic driving, and assisted driving.
Fig. 1 is a schematic structural diagram of a laser radar in the related art. Referring to fig. 1, the laser radar 10 may include: a light emitting device 101, a light receiving device 102, and a processor 103. The light emitting device 101 and the light receiving device 102 are both connected to the processor 103.
The connection relationship among the above devices may be electrical connection or optical fiber connection. More specifically, in the light emitting device 101 and the light receiving device 102, it is also possible to include a plurality of optical devices, respectively, and the connection relationship between these optical devices may also be spatial light transmission connection.
The processor 103 is used to implement control of the light emitting device 101 and the light receiving device 102 so that the light emitting device 101 and the light receiving device 102 can operate normally. For example, the processor 103 may provide driving voltages for the light emitting device 101 and the light receiving device 102, respectively, and the processor 103 may also provide control signals for the light emitting device 101 and the light receiving device 102.
Illustratively, the processor 103 may be a general-purpose processor, such as a Central Processing Unit (CPU), a Network Processor (NP), or the like; the processor 103 may also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or the like.
A light source (not shown) is also included in the light emitting device 101. It is to be understood that the light source may refer to a laser, and the number of lasers may be one or more. Alternatively, the laser may be specifically a Pulsed Laser Diode (PLD), a semiconductor laser, a fiber laser, or the like. The light source is used for emitting laser beams. In particular, the processor 103 may send an emission control signal to the light source, thereby triggering the light source to emit the laser beam.
It will be appreciated that the laser beam may also be referred to as a laser pulse, a laser, an emitted beam, etc.
Lidar 10 may further include: one or more beam shaping optics and a beam scanning device (not shown). In one aspect, beam shaping optics and a beam scanning device focus and project a laser beam toward a particular location (e.g., an object) in a surrounding environment. In another aspect, a beam scanning device and one or more beam shaping optics direct and focus the return beam onto a detector. A beam scanning device is employed in the optical path between the beam shaping optics and the target object. The beam scanning arrangement in effect expands the field of view and increases the sampling density within the field of view of the lidar.
The detection process of the laser radar on the object 104 will be briefly described below with reference to the structure of the laser radar shown in fig. 1.
Referring to fig. 1, the laser beam propagates in the emitting direction, and when the laser beam encounters an object 104, the laser beam is reflected on the surface of the object 104, and the reflected beam is received by the light receiving device 102 of the lidar. The beam of the laser beam reflected back by the object 104 may be referred to herein as an echo beam (the laser beam and echo beam are identified in fig. 1 by solid lines).
After receiving the echo light, the light receiving device 102 performs photoelectric conversion on the echo light, that is, converts the echo light into an electrical signal, the light receiving device 102 outputs the electrical signal corresponding to the echo light to the processor 103, and the processor 103 can obtain point cloud data of the shape, position, motion, and the like of the object 104 according to the electrical signal of the echo light.
In practical applications, when detecting an object by using a laser radar, the following situations may exist:
fig. 2 is a schematic diagram of a lidar detection scene in an embodiment of the present application, and referring to fig. 2, in a field of view of lidar 200, an object 104A is adjacent to or overlaps an object 104B, distances between the object 104A and the object 104B and the lidar 200 are different, and a distance (denoted as d) between the object 104A and the object 104B is small (e.g., d < 0.15 m). At this time, after the laser beam is emitted from the laser radar 200, a part of the spot of the laser beam falls on the object 104A, and another part falls on the object 104B. Then, the difference between the arrival times of the echo beams returned by the object 104A and the object 104B, respectively, may be less than 1 nanosecond (ns). In this case, if the pulse width of the echo light beam is greater than or equal to 1ns, the two echo light beams are superimposed, and the echo signals corresponding to the echo light beams are also superimposed. At this time, a phenomenon of "tailing" or "stringing" may occur between the point cloud obtained by the laser radar scanning the object 104A and the point cloud obtained by the scanning of the object 104B, thereby causing the boundary between the two point clouds to be unclear. Then, how to identify the abnormal signal with signal superposition is an urgent problem to be solved.
Further, fig. 3 is a schematic diagram of a relationship between the intensity and the waveform of the echo signal of the laser radar in the embodiment of the present application, and referring to fig. 3, as the intensity of the echo signal 31 increases, the amplitude of the echo signal 31 increases monotonically first. After the amplitude reaches the saturation value, the echo signal 31 becomes a saturated signal, the amplitude thereof remains almost constant, and the full width at half maximum (FWHM) gradually increases. Here, FWHM may also be referred to as pulse width, or simply pulse width. Further, as the pulse width (i.e., FWHM) of the echo signal 31 whose amplitude reaches the saturation value increases, the signal leading edge (which may also be described as the rising edge of the pulse signal) of the echo signal 31 gradually tends to stabilize. Alternatively, the echo signal 31 may remain an unsaturated signal until the amplitude reaches the saturation value.
In the laser radar detection process, for unsaturated signals, in order to reduce wandering errors, the arrival time of an echo signal is determined accurately according to the peak value of the echo signal. The arrival times of the echo signals determined in this way are very susceptible to signal superposition. For the saturated echo signal, the signal leading edge is stable and is less influenced by the wandering error, and the arrival time of the echo signal can be determined according to the signal leading edge of the echo signal, so that the influence caused by signal superposition can be reduced. For the non-saturated echo signal, the influence of the wandering error is large, and the arrival time of the echo signal is determined according to the signal leading edge of the echo signal, so that the arrival time is not accurate. Therefore, it is necessary to identify an abnormal signal with signal superposition so as to reduce the ranging error by using a more appropriate method for determining the arrival time of the echo signal. How to identify the abnormal signal is a technical problem to be solved.
In order to solve the above problem, an embodiment of the present application provides a method for identifying an abnormal echo signal. The method can be applied to an electronic device. The electronic equipment is used for identifying abnormal echo signals caused by signal superposition.
In practical applications, the electronic device may be an independent device, or may be integrated with a lidar, which is not specifically limited in this embodiment of the present application.
Fig. 4 is a schematic implementation flowchart of a method for identifying an abnormal echo signal according to an embodiment of the present application. Referring to fig. 4, the method may include: s401, S402, S403, S404, and S405.
S401, obtaining a first echo signal of the laser radar.
The first echo signal is an echo signal received by the laser radar in the process of detecting the object. The first echo signal has a certain amplitude and pulse width.
S402, determining the first echo signal as a non-saturated signal.
After obtaining the first echo signal in S401, the electronic device may determine whether the first echo signal is a non-saturated signal.
It is understood that at the moment of obtaining the first echo signal, the electronic device does not know whether the first echo signal is a saturated signal or an unsaturated signal. In this case, the electronic device may first obtain parameters of the first echo signal; and then determining whether the first echo signal is a non-saturated signal according to the parameter. For example, the electronic device may obtain an amplitude value of the first echo signal; when the amplitude value of the first echo signal reaches a preset amplitude value, determining that the first echo signal is a saturated signal; otherwise, determining the first echo signal as a non-saturated signal. Here, the preset amplitude value may be an amplitude value of a transmission signal of the lidar, or may be an amplitude value of the transmission signal of the lidar after a certain attenuation. It should be noted that the electronic device may also determine that the first echo signal is an unsaturated signal in other ways, which is not specifically limited in this embodiment of the application.
S403, a first signal-to-noise ratio of the first echo signal is determined.
After the first echo signal is determined to be the unsaturated signal in S402, in order to determine the first upper limit of the pulse width of the first echo signal, a first signal-to-noise ratio of the first echo signal needs to be determined. In the embodiments of the present application, a signal-to-noise ratio (SNR) is a ratio between a signal and noise. Here, the noise may be a noise floor. For the first echo signal, the background noise value may be predetermined, or may be determined by the electronic device based on the first echo signal, or may be obtained by the electronic device from another device for detecting the background noise, which is not specifically limited in this embodiment of the present application.
In practical applications, the signal-to-noise ratio may be a peak signal-to-noise ratio, an average signal-to-noise ratio, or the like. The first snr value is understood to be a ratio between a peak power and a background noise of the first echo signal, i.e. a peak snr. At this time, the first signal-to-noise ratio value is related to the amplitude value of the first echo signal. Alternatively, the first signal-to-noise ratio may also be understood as a ratio between an average power of the first echo signal and a bottom noise value, i.e. an average signal-to-noise ratio. At this time, the first signal-to-noise ratio value is related to the amplitude value of the first echo signal and the pulse width value of the first echo signal (i.e., the first pulse width value). Of course, there may be other situations in the first snr, which is not specifically limited in this embodiment of the present application.
In an embodiment, in response to the first signal-to-noise value being the peak signal-to-noise value, the electronic device may first obtain the amplitude value and the background noise value of the first echo signal, and then the electronic device calculates the first signal-to-noise value of the first echo signal based on the amplitude value and the background noise value of the first echo signal.
In another embodiment, in response to the first signal-to-noise value being the average signal-to-noise value, the electronic device may first obtain an amplitude value (i.e., a first amplitude value), a first pulse width value, and a bottom noise value of the first echo signal, and then the electronic device determines the first signal-to-noise value based on the first amplitude value, the first pulse width value, and the bottom noise value.
It should be noted that the first amplitude value, the first pulse width value, and the background noise value may be intermediate data generated during a general signal processing process of the first echo signal, and a specific calculation process thereof may refer to related technologies, which is not described herein for saving the description space.
In some possible embodiments, the first amplitude value may be understood as an amplitude maximum of the first echo signal. For example, if the first echo signal has only one peak, the peak of the peak is the amplitude value of the first echo signal. For another example, if the first echo signal has a plurality of peaks, the largest peak among the peaks of the plurality of peaks is the amplitude value of the first echo signal. Of course, there may be other situations in the amplitude value of the first echo signal, which is not specifically limited in this embodiment of the disclosure.
In some possible embodiments, the first pulse width value may be understood as a pulse width value of the first echo signal at a predetermined proportion of the amplitude value. Here, the preset ratio may range from 0 to 100%. For example, the preset ratio may be 40%, 50%, 60%, or the like. In one embodiment, the first pulse width value may be a full width at half maximum value of the first echo signal, that is, the first pulse width value is a pulse width value of the first echo signal at 50% of the amplitude value.
Then, in the process of obtaining the first pulse width value by signal processing the first echo signal, the electronic device may first obtain the first amplitude value, and then the electronic device may determine the first pulse width value based on the first amplitude value.
For example, the electronic device may perform interpolation processing on a leading signal edge and a trailing signal edge (which may also be described as a falling edge of the pulse signal) of the first echo signal respectively by using an interpolation algorithm according to the first amplitude value to obtain a first pulse width value, such as a full width at half maximum value of the first echo signal.
The determination of the first pulse width value will be described below by taking linear interpolation as an example.
Fig. 5 is a schematic diagram illustrating a process of performing linear interpolation on the first echo signal according to an embodiment of the present disclosure. Referring to fig. 5, the sampled first echo signal 51 is shown in a time (abscissa) -amplitude (ordinate) coordinate system. In the time-amplitude coordinate system, the direction indicated by the arrow of the abscissa axis is the time-lapse direction. The direction indicated by the arrow on the ordinate axis is the increasing direction of the amplitude. The first echo signal 51 has a signal leading edge and a signal trailing edge. The signal leading edge is a rising edge on the left side in the first echo signal 51. The signal trailing edge is a falling edge on the right side in the first echo signal 51. Further, the sampling time interval isT s . In fig. 5, the star marks "+" on the curve of the first echo signal 51 indicate the signal according toT s And sampling points for sampling the first echo signals. Sampling point S of first echo signal 0 Having the maximum ordinate value, the sampling point S 0 Is the peak value of the first echo signal with amplitude value ofA max . The amplitude values of the first echo signal on the signal leading edge and the signal trailing edge are 0.5A max Points of (a) are points F and R.
In a first step, the electronic device performs linear interpolation on the leading edge of the first echo signal 51 to obtain an amplitude valueA max At 50% (i.e. 0.5)A max ) Corresponding time of dayt 1 。
It should be appreciated that the electronic device determines the maximum amplitude of the first echo signal 51 to be S 0 Magnitude of (d)A max And on the basis of the magnitude valueA max The amplitude value at 50% was determined to be 0.5A max . Then, the electronic equipment confirms two sampling points S along the front edge of the signal 1 And S 2 . Wherein, the sampling point S 1 And the sampling point S 2 Are adjacent sampling points and correspond to time instants respectively
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And
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and sampling point S 1 Corresponding amplitude value
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Less than 0.5A max Sampling point S 2 Corresponding amplitude value
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Greater than 0.5A max . Next, since the sampling time interval is knownT s The electronic equipment can be used for judging the peak value of the first echo signalA max Sampling point S 1 Time of day (1)
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Sum amplitude value
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And a sampling point S 2 Time of day of
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Sum amplitude value
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Determining the moment corresponding to the point Ft 1 。
Illustratively, point F corresponds to the time of dayt 1 Can be obtained according to the following formula (1):
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（1）
in a second step, the electronic device may perform linear interpolation on the signal trailing edge of the first echo signal 51 to obtain 0.5A max At the corresponding timet 2 。
It will be appreciated that the electronic device determines the maximum amplitude of the first echo signal 51 to be S 0 Magnitude of (d)A max And based on the magnitude valueA max The amplitude value at 50% was determined to be 0.5A max . Then, the electronic equipment confirms two sampling points S along the back edge of the signal 3 And S 4 . Wherein, the sampling point S 3 And the sampling point S 4 Are adjacent sampling points and correspond to time instants respectively
Figure 982826DEST_PATH_IMAGE009
And
Figure 268314DEST_PATH_IMAGE010
and sampling point S 3 Corresponding amplitude value
Figure 411851DEST_PATH_IMAGE011
Greater than 0.5A max Sampling point S 4 Corresponding amplitude value
Figure 466394DEST_PATH_IMAGE012
Less than 0.5A max . Next, the sampling time interval is knownT s The electronic equipment can be used for receiving the peak value of the first echo signalA max Sampling point S 3 Time of day of
Figure 552031DEST_PATH_IMAGE013
Sum amplitude value
Figure 324815DEST_PATH_IMAGE014
And a sampling point S 4 Time of day of
Figure 6463DEST_PATH_IMAGE015
Sum amplitude value
Figure 915513DEST_PATH_IMAGE016
Determining the corresponding time of the point Rt 2 。
Illustratively, point R corresponds to time of dayt 2 Can be obtained by the following formula (2):
Figure 407937DEST_PATH_IMAGE017
（2）
it should be noted that the electronic device determinest 1 Andt 2 the steps of (a) may be performed simultaneously or sequentially, e.g., the electronic device may determine firstt 1 Re-determinationt 2 Or the electronic device may first determinet 2 Re-determinationt 1 This is not particularly limited in the embodiments of the present application.
Thirdly, the electronic equipment corresponds to the time according to the point Ft 1 And point R corresponds to timet 2 Determining a first pulse width value, i.e.t 1 And witht 2 The time interval in between.
As can be appreciated, the first pulse width value represents a length of time. Therefore, the first pulse width value can be the corresponding time of the point Ft 1 And point R corresponds to timet 2 The difference between them, i.e. the first pulse width value =t 2 -t 1 。
In the embodiment of the application, the electronic device determines the first pulse width value by adopting a linear interpolation algorithm, so that the complexity of calculation can be reduced, the calculation amount is reduced, and the calculation time length is shortened.
In practical applications, the interpolation algorithm used for determining the first pulse width value may be one of the following interpolation algorithms: linear interpolation, polynomial interpolation, spline interpolation, newton interpolation, lagrange interpolation, and the like. Of course, the interpolation algorithm may also be other algorithms, which is not specifically limited in this embodiment of the present application.
S404, determining a first pulse width upper limit value according to the first signal-to-noise ratio value.
After obtaining the first signal-to-noise ratio in S403, the electronic device determines a pulse width upper limit value (i.e., a first pulse width upper limit value) corresponding to the first signal-to-noise ratio value.
In an embodiment, the electronic device may determine a first pulse width standard deviation value corresponding to the first signal-to-noise ratio value according to a mapping relationship (i.e., a first mapping relationship) between a pre-established signal-to-noise ratio and a pulse width standard deviation; and determining a first upper pulse width value based at least on the first standard pulse width difference value.
In practical applications, for a non-saturated echo signal without signal superposition, i.e. a normal echo signal, the pulse width values at different signal-to-noise values may be different. In an embodiment, the full range of values of the snr can be divided into a plurality of snr intervals. The pulse width values of the plurality of normal echo signals within each signal-to-noise ratio interval can be considered to follow a certain distribution law. The pulse widths of the normal echo signals may be different. In this case, the normal echo signal having the signal-to-noise ratio value within the same signal-to-noise ratio interval may have a pulse width standard deviation value. In other words, there may be a mapping relationship (i.e., a first mapping relationship) between the pulse width standard deviation value and the snr interval.
In another embodiment, the electronic device may determine the first upper pulse width limit corresponding to the first signal-to-noise ratio value according to a mapping relationship (i.e., a second mapping relationship) between a pre-established signal-to-noise ratio and the upper pulse width limit.
In practical applications, the pulse width values of the plurality of normal echo signals in each signal-to-noise ratio interval can be considered to follow a certain distribution rule, and the pulse width range of the normal echo signal with the signal-to-noise ratio value in the same signal-to-noise ratio interval has an upper limit value. More specifically, for a normal echo signal, its pulse width should generally be within the range bounded by the upper limit value. Therefore, the upper limit (i.e., the maximum) of the pulse width range can be determined as the upper limit of the pulse width corresponding to the snr interval. Then there may be a mapping (i.e., a second mapping) between the signal-to-noise ratio and the upper pulse width limit.
It should be noted that the dividing manner of the signal-to-noise ratio interval may be determined according to actual situations. For example, the signal-to-noise ratio interval may be obtained by equally dividing the complete value range. The size of each signal-to-noise interval is the same. For another example, the snr interval may be obtained by non-equally dividing the full range. The size of the signal-to-noise ratio intervals is different. In addition, the complete value range of the signal-to-noise ratio can also be determined according to the actual situation. For example, the full range of values may be (0,
Figure 340121DEST_PATH_IMAGE018
) I.e. between zero and infinity. As another example, the full range of values may be (0, K), i.e., between zero and K. Where K may be a preset upper limit.
S405, when the first pulse width value is larger than the first pulse width upper limit value, the first echo signal is determined to be an abnormal echo signal.
The abnormal echo signal is an echo signal with signal superposition, that is, an unsaturated signal with signal superposition.
It is to be appreciated that after S404, the electronic device compares the first pulse width value of the first echo signal with the first upper pulse width limit value. When the comparison result indicates that the first pulse width value is greater than the first pulse width upper limit value, the electronic device may identify the first echo signal as an abnormal echo signal, that is, there is signal superposition in the first echo signal.
In an embodiment, when the comparison result indicates that the first pulse width value is less than or equal to the first pulse width upper limit value, the electronic device may identify the first echo signal as a normal echo signal, that is, there is no signal superposition in the first echo signal.
In another embodiment, when the comparison result indicates that the first pulse width value is greater than or equal to the first pulse width upper limit value, the electronic device may identify the first echo signal as an abnormal echo signal. Conversely, when the comparison result indicates that the first pulse width value is smaller than the first pulse width upper limit value, the electronic device may identify the first echo signal as a normal echo signal.
Thus, the identification process of the abnormal echo signal is completed.
It is understood that S404 can be implemented in two ways.
In some possible embodiments, the first way that the electronic device performs S404 may include: s4041 and S4042.
S4041, according to a first mapping relation between the signal-to-noise ratio and the pulse width standard deviation, a first pulse width standard deviation value corresponding to a first signal-to-noise ratio of the first echo signal is determined.
It is to be appreciated that the electronic device stores a first mapping between signal-to-noise ratio and pulse width standard deviation. Therefore, after the electronic device obtains the first signal-to-noise ratio value in S403, the electronic device may determine a pulse width standard deviation value (i.e., a first pulse width standard deviation value) corresponding to the first signal-to-noise ratio value according to the first mapping relationship.
In some possible embodiments, the electronic device may establish the first mapping relationship in advance. Fig. 6 is a schematic implementation flow diagram of establishing the first mapping relationship in the embodiment of the present application, and referring to fig. 6, the method may further include: s601, S602, and S603.
S601, a plurality of second echo signals are obtained.
The second echo signals are non-saturated signals without signal superposition, such as the above normal echo signals.
It will be appreciated that the electronic device may acquire a plurality of second echo signals as echo signal samples. In practical applications, the second echo signal may be an echo signal obtained through simulation or an echo signal actually measured. Of course, the second echo signal may also include an echo signal obtained through simulation and an echo signal actually measured at the same time, which is not specifically limited in the embodiment of the present application.
In practical applications, the echo signal samples may have as large a number of samples as possible.
In some possible embodiments, after S601, the electronic device may further perform signal processing on the plurality of second echo signals to obtain an amplitude value (i.e., a second amplitude value) of each of the second echo signals, a pulse width value (i.e., a second pulse width value) of the second echo signal, and a signal-to-noise value (i.e., a second signal-to-noise value) of the second echo signal. Since the second amplitude value, the second pulse width value, and the second signal-to-noise ratio value may be intermediate data generated during the general signal processing of the second echo signal, the specific calculation process may refer to the description of the calculation process of the first amplitude value, the first pulse width value, and the first signal-to-noise ratio value in the foregoing embodiment, and details are not repeated herein for the purpose of saving the description.
S602, determining the pulse width standard deviation values corresponding to different signal-to-noise ratio intervals.
The signal-to-noise ratio interval is obtained by dividing according to the complete value range of the signal-to-noise ratio values corresponding to the second echo signals.
It is understood that the electronic device may obtain the second signal-to-noise value and the second pulse width value of each of the second echo signals after obtaining the second echo signals. Likewise, the full range of values of the second signal-to-noise ratio value may be divided into a plurality of signal-to-noise ratio intervals. The second pulse width values of the plurality of second echo signals within each signal-to-noise ratio interval may be considered to follow a certain distribution law. Within different signal-to-noise ratio intervals, there may be a plurality of second echo signals. For example, the N second echo signals may correspond to M signal-to-noise ratio intervals, where M ≠ N, with M and N being positive integers greater than or equal to 2. Then, for each signal-to-noise ratio interval, the electronic device may determine a corresponding pulse width standard deviation value according to the second pulse width values of the plurality of second echo signals in the signal-to-noise ratio interval.
For example, the number of the second echo signals may be N, and the number of the signal-to-noise ratio intervals corresponding to the second echo signals may be M. In thatIn the M SNR intervals, the ith SNR interval may be compared with N of the N second echo signals i The second echo signals correspond to, wherein i is a positive integer less than or equal to M, and N is i Less than or equal to N. The electronic device may then determine the pulse width standard deviation value for the ith snr interval by equation (3) below.
Figure 950094DEST_PATH_IMAGE019
（3）
Wherein the content of the first and second substances,FW i representing the pulse width standard deviation value corresponding to the ith signal-to-noise ratio interval;B j represents N i A second pulse width value of a jth second echo signal of the second echo signals;
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represents N i An average of pulse widths of the second echo signals.
It should be noted that the standard deviation of the pulse width expressed by the above formula (3)FW i Is the sample standard deviation value.
S603, fitting the different signal-to-noise ratio intervals and the pulse width standard deviation to obtain a first mapping relation.
It is to be appreciated that after S602, the electronic device has determined a plurality of signal-to-noise intervals and a pulse width standard deviation value corresponding to each signal-to-noise interval. Then, based on the second signal-to-noise values in the signal-to-noise intervals and the corresponding pulse width standard deviation values, a mapping relationship (i.e., a first mapping relationship) between the second signal-to-noise values and the pulse width standard deviations can be obtained through fitting processing.
It should be noted that the fitting may be a linear fitting, a polynomial fitting, or any other suitable fitting method, and this is not particularly limited in the embodiment of the present application.
In one embodiment, piecewise linear fitting is performed on the second signal-to-noise values in the plurality of signal-to-noise intervals and the corresponding plurality of pulse width standard deviation values. For example, the second signal-to-noise ratio values in the M signal-to-noise ratio intervals and the corresponding M pulse width standard deviation values are subjected to piecewise linear fitting, so that the obtained mapping relationship can be expressed as the following formula (8):
Figure 813193DEST_PATH_IMAGE021
（4）
wherein the content of the first and second substances,FWrepresents the pulse width standard deviation;SNRrepresenting a second signal-to-noise ratio;u 0 、u 1 、……、u m are segmentation points of the signal-to-noise ratio. Segmentation pointu 0 、u 1 、……、u m And dividing m signal-to-noise ratio intervals. Within the m number of the segment intervals,FWandSNRthe linear relationship between them remains unchanged.a 1 、a 2 、……、a m Andb 1 、b 2 、……、b m respectively, parameters of a linear fit within m signal-to-noise ratio intervals, wherein,a 1 、a 2 、……、a m a slope parameter representing a linear function over m signal-to-noise ratio intervals,b 1 、b 2 、……、b m represents the intercept parameter of the linear function over m signal-to-noise intervals.
In practical application, the segmentation pointu 0 、u 1 、……、u m It may be preset or determined based on the distribution of the plurality of signal-to-noise values and the plurality of pulse width standard deviations in the fitting process. For example, the interval lengths of the m signal-to-noise ratio intervals may be the same or different. For another example, the interval length of the m signal-to-noise ratio intervals may be fixed, or may be dynamically adjusted in the fitting process.
Because the multi-segment linear fitting only needs to execute multiplication and addition operation, the operation amount needed in the fitting process aiming at the mapping relation is greatly reduced, and the time length of the fitting process is effectively shortened.
Thus, through S601, S602, and S603, the electronic device can obtain the first mapping relationship.
S4042, determining a first upper limit value of the pulse width according to at least the first standard deviation value of the pulse width.
It is understood that the first upper limit value of the pulse width can be obtained by calculation or table lookup.
In an embodiment, the electronic device may calculate the first upper pulse width limit value at least according to the first standard pulse width difference value. In this manner, the electronic device may perform the following two operations:
and operation 1, determining a target coefficient corresponding to the first signal-to-noise ratio value according to the detection probability of the laser radar and the first pulse width standard difference value.
Wherein the target coefficient represents a multiple of the standard deviation from the mean. The normal distribution probability table may be obtained by querying a predetermined detection probability table.
And 2, determining a first pulse width upper limit value according to the target coefficient, the reference pulse width value and the first pulse width standard difference value.
In an example, for the ith snr interval, the electronic device can calculate a first upper pulse width limit corresponding to the first standard pulse width difference value according to the following equation (5):
Figure 294990DEST_PATH_IMAGE022
（5）
wherein the content of the first and second substances,B 0 representing a reference pulse width value;αindicating the multiple of standard deviation from the mean, according to a predetermined detection probabilityP d Querying a normal distribution probability table to obtain;FWrepresenting a first pulse width standard deviation;
Figure 334753DEST_PATH_IMAGE023
indicating a first upper pulse width limit. The reference pulse width value can be obtained by counting the pulse widths of a large number of unsaturated signals, and in the same laser radar, the reference pulse width value is basedThe fixed value is considered to be an average value of the pulse width of the unsaturated signal received by the laser radar.
In an embodiment, the electronic device may obtain the first upper limit value of the pulse width at least according to a look-up table of the first standard deviation value of the pulse width.
In this case, the electronic device may obtain a lookup table (or referred to as a mapping table, a relation table, or the like) between the pulse width standard deviation and the pulse width upper limit in advance.
In some possible embodiments, the second way that the electronic device performs S404 may include: s4043.
S4043, determining a first upper limit of the pulse width corresponding to the first signal-to-noise ratio of the first echo signal according to a second mapping relationship between the signal-to-noise ratio and the upper limit of the pulse width.
It is to be appreciated that the electronic device stores a second mapping between the signal-to-noise ratio and the upper pulse width limit. Therefore, after the electronic device obtains the first signal-to-noise ratio value in S403, the electronic device may determine a pulse width upper limit value (i.e., a first pulse width upper limit value) corresponding to the first signal-to-noise ratio value according to the second mapping relationship.
In some possible embodiments, the electronic device may establish the second mapping relationship in advance. Fig. 7 is a schematic implementation flow diagram of establishing the second mapping relationship in the embodiment of the present application, and referring to fig. 7, the method may further include: s701, S702, S703 and S704.
S701, a plurality of second echo signals are obtained.
The second echo signals are non-saturated signals without signal superposition.
S702, determining the pulse width standard difference values corresponding to different signal-to-noise ratio intervals.
The signal-to-noise ratio interval is obtained by dividing the value range of the signal-to-noise ratio values corresponding to the second echo signals.
It should be noted that the implementation of S701 and S702 is completely the same as the implementation of S601 and S602 described above, and is not described herein again.
And S703, determining the pulse width upper limit values corresponding to the different signal-to-noise ratio intervals at least according to the pulse width standard difference value.
It can be understood that, after obtaining the pulse width standard difference values in different signal-to-noise ratio intervals through S702, the electronic device may multiply the pulse width standard difference value corresponding to each signal-to-noise ratio interval by a target coefficient according to a detection probability requirement of the laser radar, and use the multiplied value and the reference pulse width value as a second pulse width upper limit value in the signal-to-noise ratio interval, thereby reducing a risk that the second echo signal is mistakenly identified as an abnormal echo signal.
In the embodiment of the present application, the detection probability of the lidar may be understood as detection probability, discovery probability, and the like of the lidar. The detection probability is the probability description of the target finding capability of the laser radar, namely the probability of judging the occurrence of the target by the laser radar when the target exists.
In some possible embodiments, the step S703 may include: and the electronic equipment determines the target coefficients in different signal-to-noise ratio intervals according to the detection probability of the laser radar and the pulse width standard difference value. And then, the electronic equipment determines a second pulse width upper limit value under different signal-to-noise ratio intervals according to the target coefficient, the reference pulse width value and the pulse width standard difference value.
It can be understood that, for a signal-to-noise ratio interval, the electronic device may determine, according to a distribution of pulse width values corresponding to the signal-to-noise ratio interval, the number of echo signal samples whose pulse widths fall within a preset range, and then determine a probability value that each pulse width value falls within the preset range. Then, by setting different probability values, the electronic device can obtain different preset ranges (i.e., pulse width ranges), and further obtain different upper limit values of the pulse width (i.e., upper limit values of the pulse width ranges). In practical applications, the probability value may be set according to actual requirements.
Firstly, the electronic equipment determines target coefficients in different signal-to-noise ratio intervals according to the detection probability of the laser radar and the pulse width standard difference value.
As can be appreciated, it is possible to,the distribution of the pulse width values of a plurality of echo signal samples within the same snr interval may conform to a gaussian distribution (or referred to as a normal distribution). In this case, for the standard deviation of the pulse widthFW i The probability density function of the pulse width is expressed as formula (6):
Figure 421657DEST_PATH_IMAGE024
（6）
wherein the content of the first and second substances,P(B) The probability density of the pulse width is represented,B 0 a value representing the width of the reference pulse, wherein,B 0 are empirical values.
The detection probability indicates the probability that the normal signal can be recognized as the normal signal, and particularly in the present embodiment, the detection probabilityP d Equal to the probability that the second pulse width value is less than the second pulse width upper limit value. From this, equation (7) can be obtained:
Figure 567468DEST_PATH_IMAGE025
（7）
wherein the content of the first and second substances,B d and represents the second pulse width upper limit value. At the probability of detectionP d After the determination, the second pulse width upper limit value can be calculated according to the formula (6) and the formula (7)B d . It should be noted that the probability of detectionP d The specific value of (3) may be determined according to the measurement accuracy, application scenario, hardware performance, and the like of the laser radar, which is not specifically limited in this embodiment of the present application.
In practical operation, the pulse width of the signal follows a normal distribution N (B 0 ，FW i ) Second upper limit of pulse widthB d = B 0 + α·FW i ，αRepresents the multiple of the standard deviation from the mean. Can be based on the preset detection probabilityP d Querying a normal distribution probability table to obtain the target systemNumber ofα，Thereby calculating the upper limit value of the pulse widthB d 。
And secondly, the electronic equipment determines a second pulse width upper limit value under different signal-to-noise ratio intervals according to the target coefficient, the reference pulse width value and the pulse width standard difference value.
It can be understood that, for different second signal-to-noise ratio intervals, the electronic device multiplies the corresponding standard deviation of the pulse width by the target coefficient corresponding to the signal-to-noise ratio interval, and adds the reference pulse width value on the basis of the product of the two, so as to obtain second upper limit values of the pulse width corresponding to the different signal-to-noise ratio intervals.
For example, for the ith signal-to-noise ratio interval, the corresponding second upper limit value of the pulse width may be calculated according to the following formula (8):
Figure 536561DEST_PATH_IMAGE026
（8）
wherein, the first and the second end of the pipe are connected with each other,
Figure 612970DEST_PATH_IMAGE027
and the second pulse width upper limit value corresponding to the ith signal-to-noise ratio interval is shown.
The comparison table in S4042 may be obtained as described above.
S704, fitting the signal-to-noise ratio and the pulse width upper limit value to obtain the second mapping relationship. .
It is to be appreciated that after S702, the electronic device has determined a plurality of signal-to-noise intervals and a pulse width standard deviation value corresponding to each signal-to-noise interval. Then, based on the second signal-to-noise values in the signal-to-noise intervals and the corresponding pulse width standard deviations, a mapping relationship between the second signal-to-noise values and the pulse width standard deviations can be obtained through fitting processing.
In an example, based on the mapping relationship (4) between the second signal-to-noise ratio value and the pulse width standard deviation obtained by fitting in S603, and in combination with equation (8), fitting between the second signal-to-noise ratio value and the second pulse width upper limit value can be achieved, so that the second mapping relationship is obtained.
In the embodiment of the application, for a non-saturated echo signal received by a laser radar, a pulse width value of the echo signal is compared with a pulse width upper limit value corresponding to a signal-to-noise ratio of the echo signal, so as to identify whether the echo signal has signal superposition, that is, identify whether the echo signal is an abnormal echo signal. Furthermore, since the identification of the abnormal signal in the embodiment of the present application may be based only on the signal-to-noise ratio and the pulse width of the echo signal, and no change is required to be made to the hardware circuit, the workload on the circuit design caused by the change of the hardware circuit is avoided. Further, in the embodiment of the present application, the identification of the abnormal signal is based on the pulse width of the echo signal, and the pulse width of the unsaturated signal is easily obtained, so the method for identifying the abnormal signal described in the embodiment of the present application can be applied to most unsaturated signals. Furthermore, the abnormal signal identification method can be carried out by utilizing process data generated by the echo signal in the general signal processing process without image processing, thereby greatly reducing the complexity of abnormal signal identification, shortening the time and improving the robustness. Furthermore, in the embodiment of the application, the signal-to-noise ratio of the echo signal is associated with the pulse width of the echo signal, and different upper limit values of the pulse width can be obtained for the echo signals with different signal-to-noise ratios, so that the interference of the change of the signal-to-noise ratio on the identification of the abnormal signal can be avoided, and the identification accuracy is improved.
Based on the same inventive concept, the embodiment of the application provides an abnormal echo signal identification device. The identification apparatus may be an electronic device or a chip or a system on a chip in the electronic device, and may also be a functional module in the electronic device for implementing the method described in the foregoing embodiment and any possible implementation manner of the foregoing embodiment. The identification apparatus may implement the functions performed by the electronic device in the above embodiments and any possible implementation manner, and these functions may be implemented by hardware executing corresponding software. These hardware or software include one or more functionally corresponding modules. Fig. 8 is a schematic structural diagram of an apparatus for identifying an abnormal echo signal in an embodiment of the present application. Referring to fig. 8, the recognition apparatus 800 may include: an obtaining module 801, configured to obtain a first echo signal of a laser radar; a determining module 802, configured to determine that the first echo signal is an unsaturated signal, determine a first signal-to-noise ratio of the first echo signal, and determine a first pulse width upper limit according to the first signal-to-noise ratio; the identifying module 803 is configured to identify the first echo signal as an abnormal echo signal when the first pulse width value of the first echo signal is greater than the first pulse width upper limit value, where the abnormal echo signal is an echo signal with signal superposition.
In some possible implementations, the determining module 802 may be configured to: determining a first pulse width standard deviation value corresponding to a first signal-to-noise ratio value of the first echo signal according to a first mapping relation between the signal-to-noise ratio and the pulse width standard deviation; a first upper pulse width limit is determined based at least on the first standard pulse width difference.
In some possible implementations, the obtaining module 801 may further be configured to: a plurality of second echo signals are obtained, the plurality of second echo signals being a plurality of non-saturated signals without signal superposition. The determining module 802 may also be configured to: and determining pulse width standard difference values corresponding to different signal-to-noise ratio intervals, wherein the signal-to-noise ratio intervals are obtained by dividing according to the value ranges of the signal-to-noise ratios corresponding to the second echo signals. The above apparatus may further include: a calculating module 804, configured to fit the different signal-to-noise ratio intervals and the pulse width standard deviation values to obtain a first mapping relationship.
In some possible implementations, the determining module 802 may be to: determining a target coefficient corresponding to the first signal-to-noise ratio according to the detection probability of the laser radar and the first pulse width standard difference; and determining a first pulse width upper limit value according to the target coefficient, the reference pulse width value and the first pulse width standard deviation value.
In some possible implementations, the determining module 802 may be configured to: and determining a first pulse width upper limit value corresponding to a first signal-to-noise ratio value of the first echo signal according to a second mapping relation between the signal-to-noise ratio and the pulse width upper limit.
In some possible implementations, the obtaining module 801 may be further configured to: a plurality of second echo signals are obtained, the plurality of second echo signals being a plurality of non-saturated signals without signal superposition. The determining module 802 may also be for: determining pulse width standard difference values corresponding to different signal-to-noise ratio intervals, wherein the signal-to-noise ratio intervals are obtained by dividing according to the value ranges of the signal-to-noise ratios corresponding to the second echo signals; and determining the upper limit value of the pulse width corresponding to the different signal-to-noise ratio intervals at least according to the standard difference value of the pulse width. The above apparatus may further include: a calculating module 804, configured to fit the signal-to-noise ratio value and the pulse width upper limit value to obtain a second mapping relationship.
In some possible implementations, the determining module 802 may be to: determining a target coefficient corresponding to a signal-to-noise ratio interval according to the detection probability of the laser radar and the pulse width standard difference value; and determining the upper limit value of the pulse width according to the target coefficient, the reference pulse width value and the standard pulse width difference value.
In some possible implementations, the determining module 802 may be configured to: determining second signal-to-noise values corresponding to the second echo signals and second pulse width values of the second echo signals; and determining a pulse width standard deviation value according to the second pulse width value.
It should be noted that, for the specific implementation processes of the obtaining module 801, the determining module 802, the identifying module 803, and the calculating module 704, reference may be made to the detailed descriptions of the embodiments corresponding to fig. 4 to fig. 7, and for the sake of brevity of the description, the detailed descriptions are omitted here.
The obtaining module 801, the determining module 802, the identifying module 803, and the calculating module 804 mentioned in the embodiments of the present application may be one or more processors.
Based on the same inventive concept, embodiments of the present application provide an electronic device, which may be the electronic device described in one or more embodiments above. Fig. 9 is a schematic structural diagram of an electronic device in an embodiment of the present application, and referring to fig. 9, an electronic device 900 may employ general-purpose computer hardware, and includes a processor 901 and a memory 902.
In one embodiment, the processor 901 and the memory 902 may communicate over a bus 903.
In some possible implementations, the at least one processor 901 may constitute any physical device having circuitry to perform logical operations on one or more inputs. For example, at least one processor may include one or more Integrated Circuits (ICs), including an Application Specific Integrated Circuit (ASIC), a microchip, a microcontroller, a microprocessor, all or a portion of a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), a Digital Signal Processor (DSP), a Field Programmable Gate Array (FPGA), or other circuitry suitable for executing instructions or performing logical operations. The instructions executed by the at least one processor may be preloaded into a memory integrated with or embedded in the controller, for example, or may be stored in a separate memory. The memory may include Random Access Memory (RAM), read-only memory (ROM), hard disk, optical disk, magnetic media, flash memory, other persistent, fixed, or volatile memory, or any other mechanism capable of storing instructions. In some embodiments, the at least one processor may comprise more than one processor. Each processor may have a similar structure, or the processors may have different configurations that are electrically connected or disconnected from each other. For example, the processor may be a separate circuit or integrated in a single circuit. When more than one processor is used, the processors may be configured to operate independently or cooperatively. The processors may be coupled electrically, magnetically, optically, acoustically, mechanically or by other means allowing them to interact. According to an embodiment of the present application, there is also provided a computer readable storage medium having stored thereon computer instructions for executing the steps of the above calibration method by a processor. The memory 902 may include computer storage media in the form of volatile and/or nonvolatile memory such as read only memory and/or random access memory. Memory 902 may store an operating system, application programs, other program modules, executable code, program data, user data, and the like.
Further, the memory 902 described above stores computer-executable instructions for implementing the functions of the obtaining module 801, the determining module 802, the identifying module 803, and the calculating module 804 in fig. 8. The functions/implementation processes of the obtaining module 801, the determining module 802, the identifying module 803 and the calculating module 804 in fig. 8 can be implemented by the processor 901 in fig. 9 calling a computer executing instruction stored in the memory 902, and the specific implementation processes and functions refer to the above related embodiments.
Based on the same inventive concept, an embodiment of the present application provides an electronic device, including: a memory storing computer-executable instructions; a processor coupled to the memory for executing the computer-executable instructions and capable of implementing the methods described in one or more embodiments above.
Based on the same inventive concept, the present application provides a computer storage medium storing computer-executable instructions, which when executed by a processor, can implement the method according to one or more of the embodiments described above.
It should be understood by those skilled in the art that the sequence numbers of the steps in the foregoing embodiments do not imply an execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.
The above-mentioned embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing 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; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present invention, and are intended to be included within the scope of the present invention.

Claims (14)

1. A method for identifying an abnormal echo signal, the method comprising:
obtaining a first echo signal of the laser radar;
determining the first echo signal as a non-saturated signal;
determining a first signal-to-noise ratio value of the first echo signal;
determining a first pulse width upper limit value according to the first signal-to-noise ratio;
when a first pulse width value of the first echo signal is greater than a first pulse width upper limit value, identifying the first echo signal as an abnormal echo signal, wherein the abnormal echo signal is an echo signal with signal superposition;
wherein the determining the first upper limit value of the pulse width of the first echo signal includes:
determining a first pulse width standard deviation value corresponding to the first signal-to-noise ratio value of the first echo signal according to a first mapping relation between a signal-to-noise ratio and a pulse width standard deviation;
determining the first upper pulse width limit value at least according to the first standard pulse width difference value;
wherein the method further comprises:
obtaining a plurality of second echo signals, wherein the plurality of second echo signals are a plurality of unsaturated signals without signal superposition;
determining pulse width standard difference values corresponding to different signal-to-noise ratio intervals, wherein the signal-to-noise ratio intervals are obtained by dividing according to the value ranges of the signal-to-noise ratios corresponding to the plurality of second echo signals;
and fitting the different signal-to-noise ratio intervals and the pulse width standard deviation value to obtain the first mapping relation.
2. The method of claim 1, wherein determining a first upper pulse width value based on at least the first standard pulse width difference value comprises:
determining a target coefficient corresponding to the first signal-to-noise ratio according to the detection probability of the laser radar and the first pulse width standard difference value;
and determining the first pulse width upper limit value according to the target coefficient, the reference pulse width value and the first pulse width standard deviation value.
3. The method of claim 1, wherein determining the standard deviation of pulse widths for different signal-to-noise intervals comprises:
determining second signal-to-noise values corresponding to the plurality of second echo signals and second pulse width values of the plurality of second echo signals;
and determining the standard deviation value of the pulse width according to the second pulse width value.
4. A method for identifying an abnormal echo signal, the method comprising:
obtaining a first echo signal of the laser radar;
determining the first echo signal as a non-saturated signal;
determining a first signal-to-noise ratio value of the first echo signal;
determining a first pulse width upper limit value according to the first signal-to-noise ratio;
when a first pulse width value of the first echo signal is greater than a first pulse width upper limit value, identifying the first echo signal as an abnormal echo signal, wherein the abnormal echo signal is an echo signal with signal superposition;
wherein the determining the first upper limit value of the pulse width of the first echo signal includes:
determining the first upper limit value of the pulse width corresponding to the first signal-to-noise ratio of the first echo signal according to a second mapping relation between the signal-to-noise ratio and the upper limit of the pulse width;
wherein the method further comprises:
obtaining a plurality of second echo signals, wherein the plurality of second echo signals are a plurality of unsaturated signals without signal superposition;
determining pulse width standard difference values corresponding to different signal-to-noise ratio intervals, wherein the signal-to-noise ratio intervals are obtained by dividing according to the value ranges of the signal-to-noise ratios corresponding to the second echo signals;
determining the upper limit values of the pulse widths corresponding to the different signal-to-noise ratio intervals at least according to the standard difference value of the pulse widths;
and fitting the signal-to-noise ratio value and the pulse width upper limit value to obtain the second mapping relation.
5. The method of claim 4, wherein said determining the upper limit of the pulse width corresponding to the different SNR intervals according to at least the standard deviation value of the pulse width comprises:
determining a target coefficient corresponding to the signal-to-noise ratio interval according to the detection probability of the laser radar and the pulse width standard difference value;
and determining the upper limit value of the pulse width according to the target coefficient, the reference pulse width value and the standard difference value of the pulse width.
6. The method of claim 4, wherein determining the standard deviation values of pulse widths for different SNR intervals comprises:
determining second signal-to-noise values corresponding to the plurality of second echo signals and second pulse width values of the plurality of second echo signals;
and determining the standard deviation value of the pulse width according to the second pulse width value.
7. An apparatus for identifying an abnormal echo signal, the apparatus comprising:
the acquisition module is used for acquiring a first echo signal of the laser radar;
a determining module, configured to determine that the first echo signal is an unsaturated signal, determine a first signal-to-noise ratio of the first echo signal, and determine a first pulse width upper limit according to the first signal-to-noise ratio;
the identification module is used for identifying the first echo signal as an abnormal echo signal when a first pulse width value of the first echo signal is greater than a first pulse width upper limit value, wherein the abnormal echo signal is an echo signal with signal superposition;
wherein the determination module is to:
determining a first pulse width standard deviation value corresponding to the first signal-to-noise ratio value of the first echo signal according to a first mapping relation between a signal-to-noise ratio and a pulse width standard deviation;
determining the first upper pulse width limit value at least according to the first standard pulse width difference value;
wherein the obtaining module is further configured to: obtaining a plurality of second echo signals, wherein the plurality of second echo signals are a plurality of unsaturated signals without signal superposition;
the determination module is further configured to: determining pulse width standard difference values corresponding to different signal-to-noise ratio intervals, wherein the signal-to-noise ratio intervals are obtained by dividing according to the value ranges of the signal-to-noise ratios corresponding to the second echo signals;
the device further comprises:
and the calculation module is used for fitting the different signal-to-noise ratio intervals and the pulse width standard deviation value to obtain the first mapping relation.
8. The apparatus of claim 7, wherein the determining module is configured to: determining a target coefficient corresponding to the first signal-to-noise ratio according to the detection probability of the laser radar and the first pulse width standard difference value; and determining the first pulse width upper limit value according to the target coefficient, the reference pulse width value and the first pulse width standard deviation value.
9. The apparatus of claim 7, wherein the determining module is configured to: determining second signal-to-noise values corresponding to the plurality of second echo signals and second pulse width values of the plurality of second echo signals; and determining the standard deviation value of the pulse width according to the second pulse width value.
10. An apparatus for identifying an abnormal echo signal, the apparatus comprising:
the acquisition module is used for acquiring a first echo signal of the laser radar;
a determining module, configured to determine that the first echo signal is an unsaturated signal, determine a first signal-to-noise ratio of the first echo signal, and determine a first pulse width upper limit according to the first signal-to-noise ratio;
the identification module is used for identifying the first echo signal as an abnormal echo signal when a first pulse width value of the first echo signal is greater than a first pulse width upper limit value, wherein the abnormal echo signal is an echo signal with signal superposition;
wherein the determination module is to: determining the first upper limit value of the pulse width corresponding to the first signal-to-noise ratio of the first echo signal according to a second mapping relation between the signal-to-noise ratio and the upper limit of the pulse width;
wherein the obtaining module is further configured to: obtaining a plurality of second echo signals, wherein the plurality of second echo signals are a plurality of unsaturated signals without signal superposition;
the determination module is further to: determining pulse width standard difference values corresponding to different signal-to-noise ratio intervals, wherein the signal-to-noise ratio intervals are obtained by dividing according to the value ranges of the signal-to-noise ratios corresponding to the plurality of second echo signals; determining the upper limit value of the pulse width corresponding to the different signal-to-noise ratio intervals at least according to the standard difference value of the pulse width;
the device further comprises:
and the calculating module is used for fitting the signal-to-noise ratio value and the pulse width upper limit value to obtain the second mapping relation.
11. The apparatus of claim 10, wherein the determining module is configured to: determining a target coefficient corresponding to the signal-to-noise ratio interval according to the detection probability of the laser radar and the pulse width standard difference value; and determining the upper limit value of the pulse width according to the target coefficient, the reference pulse width value and the standard pulse width difference value.
12. The apparatus of claim 10, wherein the determining module is configured to: determining second signal-to-noise values corresponding to the plurality of second echo signals and second pulse width values of the plurality of second echo signals; and determining the standard deviation value of the pulse width according to the second pulse width value.
13. An electronic device, comprising:
a memory storing computer executable instructions;
a processor coupled to the memory for executing the computer-executable instructions to implement the method of any of claims 1 to 6.
14. A computer storage medium having computer-executable instructions stored thereon that, when executed by a processor, are capable of performing the method of any one of claims 1 to 6.
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