CN118688810A - Laser detection method, device, electronic device and readable storage medium - Google Patents

Abstract

The present application discloses a laser detection method, device, electronic device and readable storage medium, belonging to the field of radar technology. The method includes: obtaining a first signal collected by a first array APD, a second signal collected by a second array APD, and a target amplitude with the largest amplitude in the first signal and the second signal; when the target amplitude is greater than a preset comparison value, the signal where the target amplitude is located is determined as the target signal from the first signal and the second signal, and the validity detection of the target signal is performed, and a first target value is output based on the result of the validity detection of the target signal, and the first target value is used to characterize the laser signal; or, when the target amplitude is less than or equal to the preset comparison value, the first signal and the second signal are tested for validity, and a second target value is output based on the result of the validity detection of the first signal and the second signal, and the second target value is used to characterize the laser signal.

Description

Laser detection method, device, electronic device and readable storage medium

Technical Field

The present application belongs to the field of radar technology, and specifically relates to a laser detection method, device, electronic device and readable storage medium.

Background Art

At present, the laser radar uses a transmitting and receiving system, in which the receiving system is a single analog to digital converter (ADC) and a single-channel avalanche photo diode (APD) for reception. Since the APD is an APD array, there will be gaps in the light during the scanning process. Gaps are defined as points that cannot be detected, that is, lost points.

For single-channel signal detection, a detection threshold needs to be defined during detection. If the detection threshold is too high, small signals will not be able to pass the detection threshold, resulting in the failure to detect small signals. If the detection threshold is too low, noise will be detected, resulting in false detection.

Summary of the invention

The purpose of the embodiments of the present application is to provide a laser detection method, device, electronic device and readable storage medium, which can solve the problem of inaccurate detection results of existing laser signal detection technology.

In a first aspect, an embodiment of the present application provides a laser detection method, which is applied to a laser radar system, wherein the laser radar system includes an optical transmitter and an optical receiver, wherein the optical receiver includes a first array avalanche photodiode APD and a second array APD, and the method includes:

Acquire a first signal collected by the first array APD, a second signal collected by the second array APD, and a target amplitude with the largest amplitude between the first signal and the second signal;

In the case where the target amplitude is greater than the preset comparison value, the signal where the target amplitude is located is determined as the target signal from the first signal and the second signal, the validity detection is performed on the target signal, and a first target value is output based on the result of the validity detection of the target signal, and the first target value is used to characterize the laser signal; or

When the target amplitude is less than or equal to the preset contrast value, the first signal and the second signal are subjected to validity detection, and a second target value is output based on the results of the validity detection of the first signal and the second signal, where the second target value is used to characterize the laser signal.

Optionally, a validity check is performed on a signal to be tested, wherein the signal to be tested is any one of the first signal, the second signal and the target signal; and the validity check of the signal to be tested includes:

Get the preset detection value;

arbitrarily selecting M consecutive signal points from the signal to be measured, and obtaining the amplitudes of the M signal points, wherein M is a positive integer greater than 2;

Compare the amplitudes of the M signal points with the preset detection value,

Wherein, when the amplitudes of the M signal points are all greater than the preset detection value, the signal to be tested passes the validity detection.

Optionally, when the signal to be tested is the target signal, outputting a first target value based on a result of the validity detection of the target signal includes:

If the target signal passes the validity detection, the signal distance and/or grayscale value of the target amplitude is output, and the first target value includes the signal distance and/or grayscale value of the target amplitude.

Optionally, when the signals to be tested are the first signal and the second signal, outputting a second target value based on the results of the validity detection of the first signal and the second signal includes:

If both the first signal and the second signal pass the validity detection, obtaining a first amplitude with a maximum amplitude in the first signal and a second amplitude with a maximum amplitude in the second signal;

When the signal distance of the first amplitude and the signal distance of the second amplitude are both less than the preset distance, the signal distance of the first amplitude and the signal distance of the second amplitude are weighted, and the signal distance value obtained after the weighted processing is output, and the second target value includes the signal distance value obtained after the weighted processing.

Optionally, performing weighted processing on the signal distance of the first amplitude and the signal distance of the second amplitude includes:

determining a first target value according to the first amplitude and a signal distance of the first amplitude;

determining a second target value according to the second amplitude and a signal distance of the second amplitude;

Determining a third target value according to the first target value and the second target value;

determining a fourth target value according to the first amplitude and the second amplitude;

The signal distance value obtained after the weighted processing is determined according to the third target value and the fourth target value.

Optionally, the preset contrast value is the product of the background noise and a preset signal-to-noise ratio.

In a second aspect, an embodiment of the present application provides a laser detection device, which is applied to a laser radar system, wherein the laser radar system includes an optical transmitter and an optical receiver, wherein the optical receiver includes a first array APD and a second array APD,

The laser detection device comprises:

An acquisition module, used for acquiring a first signal acquired by the first array APD, a second signal acquired by the second array APD, and a target amplitude with the largest amplitude between the first signal and the second signal;

an output module, configured to, when the target amplitude is greater than a preset comparison value, determine the signal where the target amplitude is located as a target signal from the first signal and the second signal, perform validity detection on the target signal, and output a first target value based on the result of the validity detection of the target signal, wherein the first target value is used to characterize the laser signal; or

The output module is used to perform validity detection on the first signal and the second signal when the target amplitude is less than or equal to the preset comparison value, and output a second target value based on the results of the validity detection of the first signal and the second signal, wherein the second target value is used to characterize the laser signal.

Optionally, the laser detection device further includes a detection module, and the detection module is used to:

Get the preset detection value;

arbitrarily selecting M consecutive signal points from the signal to be tested, and obtaining the amplitudes of the M signal points, wherein M is a positive integer greater than 2, and the signal to be tested is any one of the first signal, the second signal, and the target signal;

Compare the amplitudes of the M signal points with the preset detection value,

Wherein, when the amplitudes of the M signal points are all greater than the preset detection value, the signal to be tested passes the validity detection.

In a third aspect, an embodiment of the present application provides an electronic device, comprising a processor and a memory, wherein the memory stores programs or instructions that can be run on the processor, and when the program or instructions are executed by the processor, the steps of the laser detection method described in the first aspect are implemented.

In a fourth aspect, an embodiment of the present application provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, the steps of the laser detection method described in the first aspect are implemented.

In the embodiment of the present application, the laser detection method is applied to a laser radar system capable of dual-path detection and having a first array APD and a second array APD, and can detect smaller signals, making the final output signal result more accurate. In addition, in the process of dual-path detection, the first signal and the second signal are tested for validity based on whether the maximum amplitude of the first signal and the second signal meets the preset comparison value, so as to eliminate the interference of the noise signal, further improving the accuracy of the final output signal result, that is, improving the accuracy of the detection result of the laser detection method.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the structure of a laser radar system provided in an embodiment of the present application;

FIG2 is a schematic diagram of a single-path detection process of a laser radar system provided in an embodiment of the present application;

FIG3 is a schematic diagram of projections of a first array APD and a second array APD on corresponding receiving surfaces provided in an embodiment of the present application;

FIG4 is a schematic diagram of a process flow of a laser detection method provided in an embodiment of the present application;

FIG5 is a schematic diagram of an echo signal provided in an embodiment of the present application;

FIG6 is a schematic diagram of the structure of a laser detection device provided in an embodiment of the present application;

FIG. 7 is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

The terms "first", "second", etc. in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and/or" in the specification and claims represents at least one of the connected objects, and the character "/" generally indicates that the objects associated with each other are in an "or" relationship.

The method provided in the embodiment of the present application is described in detail below through specific embodiments and their application scenarios in conjunction with the accompanying drawings.

The laser detection method provided in the embodiment of the present application can be applied to a laser radar system, where the laser radar system includes a light transmitter and a light receiver, and the light receiver includes a first array APD and a second array APD.

As shown in FIG1 , the laser radar system includes an optical transmitter (i.e., the transmitter shown in FIG1 ) and an optical receiver, and the optical receiver includes two receiving arrays, namely a first array APD (i.e., APD1 shown in FIG1 ) and a second array APD (i.e., APD2 shown in FIG1 ).

The light transmitter emits a light beam to an object, which is reflected by the object. A portion of the reflected light returns to the lidar system and is received by the photodetector array in the light receiver, namely the first array APD and the second array PAD. The APD in the photodetector array can also be a single photon avalanche diode (SPAD), a PN photodiode or a PIN photodiode.

The laser radar system shown in Figure 1 adopts a dual-path detection mode. The dual-path detection is manifested as the first array APD and the second array APD performing single-path detection simultaneously. Now, in conjunction with Figure 2, the single-path detection process of the laser radar system is explained.

As shown in FIG2 , the laser radar system 100 may include an optical transmitter 101, a light source 102, a scanner 104, an optical receiver 106, and a controller 108. The optical transmitter 101 includes a light source 102 and a scanner 104. The light source 102 emits an emission light beam for scanning a target object 120. The light source 102 may be a laser, such as a solid-state laser (such as an edge emitting laser (Edge Emitting Laser, EEL) or a vertical cavity surface emitting laser (Vertical Cavity Surface Emitting Laser, VCSEL) or an external cavity semiconductor laser (External Cavity Diode Laser, ECDL)), a laser diode, or a fiber laser. The light source 102 may also include an LED. The light source 102 may emit light beams in different forms, including pulsed light (Time Of Flight, TOF), continuous light (Continuous Wave, CW), and quasi-continuous light. The operating wavelength of the light source may be 650nm to 1150nm, 800nm to 1000nm, 850nm to 950nm, or 1300nm to 1600nm. In one or more embodiments, the light source 102 may further include an optical component optically coupled to the light source 102 for collimating or focusing the light beam emitted by the light source 102. In one or more embodiments, the light source 102 includes at least one fiber laser. Each emission light beam emitted by the light source 102 may be continuous light for a certain period of time, or may be one or more light pulses.

The scanner 104 is used to deflect the direction of the emission light beam from the light source 102 to scan the target object 120 and achieve a wider emission field of view or a scanning field of view. The scanner 104 can be any number of optical mirrors driven by any number of drivers. For example, the scanner 104 may include a plane mirror, a prism, a mechanical galvanometer, a polarization grating, an optical phased array (OPA), and a micro-electro-mechanical system (MEMS) galvanometer. For a MEMS galvanometer, the mirror surface rotates or translates in one or two dimensions under electrostatic/piezoelectric/electromagnetic drive. Driven by the driver, the scanner 104 guides the light beam from the light source to various positions in the field of view to scan the target object 120 in the field of view.

After the light beam is reflected from the target object 120, a portion of the reflected light returns to the lidar system 100 and is received by the optical receiver 106. The optical receiver 106 receives and detects a portion of the reflected light from the target object 120 and generates a corresponding electrical signal. The optical receiver may include a receiving unit and an associated receiving circuit. Each receiving circuit may be used to process the output electrical signal of the corresponding receiving unit. The receiving unit includes various forms of photodetectors or one-dimensional or two-dimensional arrays of photodetectors, and accordingly, the receiving circuit may be one circuit or an array of multiple circuits. The photodetector measures the power, phase or time characteristics of the reflected light and generates a corresponding current output. The photodetector may be an APD, a SPAD, a PN-type photodiode or a PIN-type photodiode.

The controller 108 is communicatively coupled to one or more of the light source 102, the scanner 104, and the light receiver 106. The controller 108 can control whether and when the light source 102 emits a light beam. The controller 108 can control the scanner 104 to scan the light beam to a specific location. The controller 108 can process and analyze the electrical signal output by the light receiver to ultimately determine the position, speed, and other characteristics of the target object 120.

The controller 108 may include an integrated circuit (IC), an application specific integrated circuit (ASIC), a microchip, a microcontroller, a central processing unit, a graphics processing unit (GPU), a digital signal processor (DSP), a field programmable gate array (FPGA), or other circuits suitable for executing instructions or implementing logical operations. The instructions executed by the controller 108 may be preloaded into an integrated or separate memory (not shown). The memory may store configuration data or commands for the light source 102, the scanner 104, or the light receiver 106. The memory may also store an electrical signal output from the light receiver 106 or an analysis result based on the output electrical signal. For example, the memory may store relevant information of a stray light signal detected during a calibration period for use in a subsequent working period. The memory may include a random access memory (RAM), a read-only memory (ROM), or a read-only memory (READ-ONLY MEMORY). Only Memory, ROM), hard disk, optical disk, magnetic disk, flash memory or other volatile or non-volatile memory, etc. The controller 108 may include a single or multiple processing circuits. In the case of multiple processing circuits, each processing circuit may have the same or different structures, and interact or cooperate with each other through electrical, magnetic, optical, acoustic, mechanical, etc.

In one embodiment, the laser detection device of the present application may be a controller in a laser radar system, which is coupled to an optical transmitter and an optical receiver in the laser radar system and is used to execute the above-mentioned laser detection method.

In one or more embodiments, the laser radar system 100 may further include a transmitting lens 110. The transmitting lens 110 may be used to expand the light beam emitted by the light source 102 and deflected by the scanner 104. The transmitting lens 110 may include diffractive optical elements (DOE) for shaping, separating or diffusing the light beam. The transmitting lens 110 may exist alone or be integrated into other components (such as the scanner 104 or the light source 102). The position of the transmitting lens 110 in the transmitting light path from the light source to the target object is not limited to that shown in FIG. 2, but may be changed to other positions. For example, the transmitting lens may be arranged between the light source 102 and the scanner 104, so that the light beam emitted by the light source 102 is first expanded by the transmitting lens and then deflected by the scanner.

In one or more embodiments, the laser radar system 100 may also include a receiving lens 112 and an aperture 113. The receiving lens 112 is located before the optical receiver 106 on the receiving path of the emitted light from the target object 120 to the optical receiver 106. The receiving lens 112 may include an imaging system lens so that the focus of the reflected light beam is in front of or behind the detection surface of the photodetector or photodetector array or just above the detection surface. In some cases, instead of existing as a separate component, the receiving lens 112 may also be integrated into the optical receiver 106. The aperture 113 is used to limit the angle of the incident light incident on the optical receiver 106, block stray light, etc.

In one or more embodiments, the laser radar system 100 may further include a housing 114 for enclosing one or more of the aforementioned components for protection. In some embodiments, the housing 114 is an opaque material, and a transparent area or window 116 may be provided on the housing 114 to allow the emission beam or the reflected beam to pass through. In other embodiments, the housing 114 itself is a transparent material, thereby allowing the emission beam or the reflected beam to pass through from any position.

In some embodiments, the laser radar system 100 may include a coaxial optical transceiver system. A coaxial optical transceiver system means that the transmission path from the light source 102 to the target object 120 and the receiving path from the target object 120 to the optical receiver 106 at least partially overlap. For example, unlike what is shown in FIG. 2 , the reflected light beam may reach the optical receiver 106 after passing through the scanner 104 in the reverse direction. For a coaxial optical transceiver system, not only does the emission angle of the emission light beam change with the deflection of the scanner, but the receiving angle of the light that can be received by the optical receiver also changes synchronously with the deflection of the scanner, that is, the receiving field of view always remains equivalent to the scanning range of the emission light beam.

In other embodiments, the laser radar system 100 may include a non-coaxial optical transceiver system. A non-coaxial optical transceiver system means that there is no overlap between the transmission path from the light source 102 to the target object 120 and the reception path from the target object 120 to the optical receiver 106. For example, as shown in FIG2 , the reflected light beam does not reach the optical receiver 106 via the scanner 104. For a non-coaxial optical transceiver system, although the emission angle of the transmission light beam changes with the deflection of the scanner, the total receiving field of view of the optical receiver is fixed and does not change with the deflection of the scanner. The above is a description of the process of single-path detection of the laser radar system 100.

Referring to FIG. 1 and FIG. 2, in the dual-path detection laser radar system shown in FIG. 1, the first array APD includes a plurality of first receiving channels, the second array APD includes a plurality of second receiving channels, and the two receiving arrays of the optical receiver are arranged at different positions on the receiving surface of the light beam, so that the receiving light spot of the reflected light beam with the same incident angle can be inconsistent in the position matching degree between any first receiving channel and any second receiving channel, thereby generating two receiving signals with different signal strengths. In particular, when one of the signals is a small signal, the other receiving signal may not be a small signal, thereby avoiding false detection.

Both the first array APD and the second array APD have corresponding channel arrangement directions and the same channel spacing. Based on the periodic characteristics of the array, when the receiving positions of the first array APD and the second array APD for the reflected light beam are different, the relative position of any first receiving channel is different from the relative positions of all second receiving channels.

Further, the positions of the first array APD and the second array APD on the receiving surface of the light beam are set so that: relative to the projection of the corresponding receiving lens on the receiving surface along the optical axis direction, the relative position of any first receiving channel is different from the relative position of all second receiving channels. That is, the relative position of any first receiving channel in the first array APD relative to the projection of the corresponding receiving lens on the corresponding receiving surface along the optical axis direction is different from the relative position of all second receiving channels in the second array APD relative to the projection of the corresponding receiving lens 112 on the corresponding receiving surface along the optical axis direction.

Both the first array APD and the second array APD have non-photosensitive areas. The non-photosensitive areas of the first array APD are located between adjacent first receiving channels and are distributed in a grid shape; the non-photosensitive areas of the second array APD are located between adjacent second receiving channels and are distributed in a grid shape. When comparing the relative positions of the corresponding receiving lenses, because the relative position of any first receiving channel is different from the relative position of all second receiving channels, the relative position of the non-photosensitive area on the first receiving surface corresponding to the first array APD is staggered with the relative position of the non-photosensitive area on the second receiving surface corresponding to the second array APD, so that in the two array APDs, the first set of reflected light beams in one array APD that cannot be detected because the receiving light spot falls into the non-photosensitive area is not completely overlapped with the second set of reflected light beams in the other array APD that cannot be detected because the receiving light spot falls into the non-photosensitive area. That is, the GAP area of the first array APD and the GAP area of the second array APD do not completely overlap. Therefore, the dual-path GAP area obtained by dual-path detection is smaller than the GAP area of single-path detection.

Furthermore, by adjusting the deviation between the relative position of the receiving channels included in one of the first array APD and the second array APD and the relative position of the receiving channels in the other array APD, the dual-path GAP area obtained by the dual-path detection can be further reduced. Preferably, the relative position of any first receiving channel is adjusted so that the deviation between all relative positions of the second receiving channel approaches a general odd multiple of the channel spacing in the corresponding direction, so that the GAP areas of the two array APDs are staggered, further reducing the dual-path GAP area obtained by the dual-path detection.

In the embodiment shown in Figure 3, the positions of the first array APD (i.e., the first array 558-1 of receiving channels shown in Figure 3) and the second array APD (i.e., the first array 558-2 of receiving channels shown in Figure 3) on the corresponding receiving surfaces are set so that, relative to the projection of the corresponding receiving lenses (the first array APD corresponds to the first receiving lens 542-1, and the second array APD corresponds to the second receiving lens 542-2) along the optical axis direction on the receiving surface, the deviation between the relative position of any first receiving channel in the first array APD and the relative position of all second receiving channels in the second array APD in each arrangement direction is an odd multiple of half of the corresponding channel spacing.

As a result, the GAP area of the first array APD receiving the light beam does not completely overlap with the GAP area of the second array PAD receiving the light beam. It can be understood that the range of the GAP area obtained by using the first array APD and the second array APD to simultaneously receive the light beam is smaller than the range of the GAP area obtained by using only the first array APD or the second array APD.

Furthermore, by adjusting the deviation between the position of any first receiving channel and the positions of all second receiving channels, or adjusting the deviation between the position of any second receiving channel and the positions of all first receiving channels, the GAP area of the light beams received when the first array APD and the second array APD are used simultaneously can be further reduced. By reducing the range of the GAP area, smaller signals can be detected without reducing the false detection rate, thereby making the final output signal result more accurate.

Please further refer to Figure 1. The laser radar system also includes a first signal conversion component corresponding to the first array APD and a second signal conversion component corresponding to the second array APD. The first signal conversion component includes a first transimpedance amplifier (Trans Impedance Amplifier, TIA) (i.e., TIA1 shown in Figure 1), a first amplifier (i.e., amplifier 1 shown in Figure 1) and a first analog to digital converter (Analog to Digital Converter, ADC) (i.e., ADC1 shown in Figure 1), and the second signal conversion component includes a second transimpedance amplifier (i.e., TIA2 shown in Figure 1), a second amplifier (i.e., amplifier 2 shown in Figure 1) and a second analog to digital converter (i.e., ADC2 shown in Figure 1). The first signal conversion component is used to convert the optical signal received by the first array APD into an electrical signal, and the second conversion component is used to convert the optical signal received by the second array APD into an electrical signal.

As shown in FIG4 , the laser detection method provided in the embodiment of the present application includes the following steps:

Step S1, obtaining a first signal collected by the first array APD, a second signal collected by the second array APD, and a target amplitude with the largest amplitude between the first signal and the second signal,

Please refer to Figure 1. It should be noted that after the optical transmitter emits a light beam to an object, part of the light beam is reflected by the object to the first array APD and the second array APD. The signal received by the first array APD and the second array APD is the echo signal of the light beam. After the first array APD and the second array APD receive the echo signal of the light beam, the corresponding signal conversion component will convert the optical signal into an electrical signal. Finally, the electrical signal can be represented as the schematic diagram of the echo signal shown in Figure 5. In Figure 5, the horizontal axis is time and the vertical axis is the amplitude of the light echo signal.

In this step, maximum value detection can be performed on the first signal collected by the first array APD and the second signal collected by the second array APD, for example, based on the echo signal schematic diagram corresponding to the first array APD and the echo signal schematic diagram corresponding to the second array APD, to determine the target amplitude with the largest amplitude.

Step S21, when the target amplitude is greater than a preset comparison value, from the first signal and the second signal, the signal where the target amplitude is located is determined as the target signal, the validity detection of the target signal is performed, and a first target value is output based on the result of the validity detection of the target signal, and the first target value is used to characterize the laser signal.

The target amplitude is compared with a preset contrast value, which can be determined by the background noise and a preset signal-to-noise ratio, and the preset signal-to-noise ratio can be set manually or adjusted according to subsequent output results.

Optionally, the preset signal-to-noise ratio may be a signal amplitude greater than P times the amplitude of the background noise, where P may be selected as 6, 7, or 8. When the target amplitude is greater than the preset comparison value, it can be considered that the signal strength of the signal corresponding to the target amplitude is a large signal with a high detection accuracy. A further validity test is performed on the target signal with a high detection accuracy, and based on the result of the validity test, it is determined how to output the first target value to eliminate the influence of the noise signal.

Step S22, when the target amplitude is less than or equal to the preset comparison value, performing validity detection on the first signal and the second signal, and outputting a second target value based on the results of the validity detection of the first signal and the second signal, wherein the second target value is used to characterize the laser signal,

The target amplitude is compared with the preset contrast value. When the target amplitude is less than or equal to the preset contrast value, it means that neither the first signal nor the second signal is a large signal that meets the preset signal-to-noise ratio. Then, the validity of the first signal and the second signal are tested. The output of the second target value is determined based on the validity test results of the first signal and the second signal to eliminate the influence of the modeling signal.

The laser detection method provided in the embodiment of the present application is applied to a laser radar system capable of dual-path detection and having a first array APD and a second array APD, and can detect smaller signals, making the final output signal result more accurate. In addition, in the process of dual-path detection, the first signal and the second signal are tested for validity based on whether the maximum amplitude of the first signal and the second signal meets the preset comparison value, so as to eliminate the interference of the noise signal, further improving the accuracy of the final output signal result, that is, improving the accuracy of the detection result of the laser detection method.

Optionally, a validity check is performed on a signal to be tested, wherein the signal to be tested is any one of the first signal, the second signal and the target signal; and the validity check of the signal to be tested includes:

Get the preset detection value,

The preset detection value may be a detection threshold amplitude, which may be determined by a false alarm rate. The false alarm rate is the probability that a noise signal is detected in the absence of an echo. Assuming that the root mean square of the noise signal amplitude is σ _noise , according to σ _{noise ,} it can be known that the noise signal obeys N(μ,σ _noise ). For any threshold amplitude m ₀ , the probability that a noise signal is mistakenly detected as an echo is:

Where P _FA is the probability that a noise signal is mistakenly detected as an echo, and m ₀ is an arbitrary threshold amplitude.

Based on the above derivation process, for the case where the false alarm rate is 10 ^-6 and 1000 signal points are detected each time, the detection threshold amplitude can be calculated to be 5.998σ _noise . It should be noted that when the signal to be detected is the first signal, the second signal or the target signal, the corresponding detection threshold amplitude can be adjusted accordingly according to the type of the signal to be detected, so as to ensure that the noise signal is excluded as much as possible without causing missed detection.

arbitrarily selecting M consecutive signal points from the signal to be measured, and obtaining the amplitudes of the M signal points, wherein M is a positive integer greater than 2;

Preferably, M is 3. When M is 3, when the signal to be detected is the target signal, the corresponding preset detection value, that is, the detection threshold amplitude is 3.09σ _noise . When M is 3, when the signal to be detected is the first signal or the second signal, the corresponding preset detection value, that is, the detection threshold amplitude is 1.91σ _noise .

Compare the amplitudes of the M signal points with the preset detection value,

When the signal to be measured is the target signal, three consecutive points are randomly selected from the target signal, and the amplitudes of the three consecutive points are compared with 3.09σ _noise . When the signal to be measured is the first signal or the second signal, three consecutive points are randomly selected from the first signal or the second signal, and the amplitudes of the three consecutive points are compared with 1.91σ _noise .

Wherein, when the amplitudes of the M signal points are all greater than the preset detection value, the signal to be tested passes the validity detection.

For the signal to be tested, when any three consecutive points on the signal to be tested are greater than the corresponding preset detection value, the signal to be tested is judged to have passed the validity test. On the contrary, when any point among any three consecutive points on the signal to be tested is less than or equal to the corresponding preset detection value, the signal to be tested is judged to have failed the validity test. It should be noted that by selecting three consecutive points to compare with the preset detection value, even if the noise signal suddenly increases and is collected, the probability that three consecutive noise signals increase and are collected is extremely low. Therefore, when any three consecutive points on the signal to be tested are greater than the corresponding preset detection value, it can be considered that the signal to be tested has passed the validity test, and there is no need to test the remaining signal points on the signal to be tested, which simplifies the validity test process.

Optionally, when the signal to be tested is the target signal, outputting a first target value based on a result of the validity detection of the target signal includes:

If the target signal passes the validity detection, the signal distance and/or grayscale value of the target amplitude is output, and the first target value includes the signal distance and/or grayscale value of the target amplitude.

If the target signal passes the validity test, it means that the maximum amplitude in the first signal or the second signal is greater than the preset comparison value, which means that the target signal corresponding to the target amplitude is a large signal with a high detection accuracy. Therefore, the signal distance or grayscale value of the target amplitude can be directly output, or the signal distance and grayscale value of the target amplitude can be output. The signal distance of the target amplitude can be determined by the centroid method or the frontier method. It should be noted that if the target signal fails the validity test, the numerical value used to characterize the laser signal will not be output to exclude the influence of the noise signal.

When the target signal passes the validity detection, the first target value is output, eliminating the influence of the noise signal and ensuring the accuracy of the detection result of the laser detection method of this embodiment.

Optionally, when the signals to be tested are the first signal and the second signal, outputting a second target value based on the results of the validity detection of the first signal and the second signal includes:

If both the first signal and the second signal pass the validity detection, obtaining a first amplitude with the largest amplitude in the first signal and a second amplitude with the largest amplitude in the second signal,

It should be noted that if one of the first signal and the second signal fails the validity test, the value used to characterize the laser signal will not be output to eliminate the influence of the noise signal. If both the first signal and the second signal pass the validity test, the signal point and amplitude with the largest amplitude among all signal points of the first signal and the signal point and amplitude with the largest amplitude among all signal points of the second signal are obtained respectively.

When the signal distance of the first amplitude and the signal distance of the second amplitude are both less than the preset distance, the signal distance of the first amplitude and the signal distance of the second amplitude are weighted, and the signal distance value obtained after the weighted processing is output, and the second target value includes the signal distance value obtained after the weighted processing.

It should be noted that, although both the first signal and the second signal have passed the validity test, there is no condition in the first signal and the second signal that the target amplitude satisfies the preset comparison value. Therefore, the first signal and the second signal need to be further processed.

Specifically, the signal distance of the first amplitude and the signal distance of the second amplitude are obtained by the center of gravity method or the frontier method, and the preset distance is determined based on experience. Preferably, the preset distance is 5 cm, and the preset distance can be adjusted according to actual conditions. The signal distance of the first amplitude and the signal distance of the second amplitude are compared with the preset distance. Only when the signal distance of the first amplitude and the signal distance of the second amplitude are both less than the preset distance, the signal distance of the first amplitude and the signal distance of the second amplitude are weighted. If the above conditions are not met, the numerical value used to characterize the laser signal will not be output to eliminate the influence of the noise signal. Through the above steps, the influence of the noise signal is further eliminated, and the accuracy of the detection result of the laser detection method provided in the embodiment of the present application is improved.

Optionally, performing weighted processing on the signal distance of the first amplitude and the signal distance of the second amplitude includes:

determining a first target value according to the first amplitude and a signal distance of the first amplitude;

Determining a third target value according to the first target value and the second target value;

determining a fourth target value according to the first amplitude and the second amplitude;

The signal distance value obtained after the weighted processing is determined according to the third target value and the fourth target value.

For example, the first amplitude V1 is obtained, the signal distance R1 of the second amplitude is obtained, and the first target value is determined to be (V1×R1) according to the product of the signal distances of the first amplitude and the second amplitude; the second amplitude V2 is obtained, the signal distance R2 of the second amplitude is obtained, and the second target value is determined to be (V2×R2) according to the product of the signal distances of the first amplitude and the second amplitude; the third target value is determined to be (V1×R1+V2×R2) according to the sum of the first target value and the second target value; the fourth target value is determined to be (V1+V2) according to the sum of the first amplitude and the second amplitude; and the signal distance value obtained after weighted processing is determined to be [(V1×R1+V2×R2)/(V1+V2)] according to the quotient of the third target value and the fourth target value. By weighted processing the signal distance of the first amplitude and the signal distance of the second amplitude, and outputting the second target value, the interference of the noise signal is further eliminated, and the accuracy of the detection result of the laser detection method of the embodiment of the present application is ensured.

Optionally, the preset contrast value is the product of the background noise and a preset signal-to-noise ratio. The background noise is determined according to the light transmitter of the laser radar system, and the preset signal-to-noise ratio can be manually set for easy adjustment. By comparing the target amplitude and the product of the background noise and the preset signal-to-noise ratio, it is determined whether the signal corresponding to the target amplitude is a large signal, the steps are simple, and the judgment result is accurate.

The laser detection method provided in the embodiment of the present application can be executed by a laser detection device used in a laser radar system. The laser radar system includes a light transmitter and a light receiver. The light receiver includes a first array APD and a second array APD.

In the embodiment of the present application, a laser detection device executing a laser detection method is taken as an example, and the laser detection device 600 provided in the embodiment of the present application is described in conjunction with FIG. 6 . The laser detection device 600 includes:

An acquisition module 601 is used to acquire a first signal collected by the first array APD, a second signal collected by the second array APD, and a target amplitude with the largest amplitude between the first signal and the second signal;

The output module 602 is used to determine the signal where the target amplitude is located as the target signal from the first signal and the second signal when the target amplitude is greater than a preset comparison value, perform validity detection on the target signal, and output a first target value based on the result of the validity detection of the target signal, wherein the first target value is used to characterize the laser signal; or

The output module 602 is used to perform validity detection on the first signal and the second signal when the target amplitude is less than or equal to the preset comparison value, and output a second target value based on the results of the validity detection of the first signal and the second signal, wherein the second target value is used to characterize the laser signal.

Optionally, the laser detection device further includes a detection module, and the detection module is used to:

Get the preset detection value;

arbitrarily selecting M consecutive signal points from the signal to be tested, and obtaining the amplitudes of the M signal points, wherein M is a positive integer greater than 2, and the signal to be tested is any one of the first signal, the second signal, and the target signal;

Compare the amplitudes of the M signal points with the preset detection value,

Wherein, when the amplitudes of the M signal points are all greater than the preset detection value, the signal to be tested passes the validity detection.

Optionally, when the signal to be tested is the target signal, the output module 602 is further used to:

If the target signal passes the validity detection, the signal distance and/or grayscale value of the target amplitude is output, and the first target value includes the signal distance and/or grayscale value of the target amplitude.

Optionally, when the signal to be measured is the first signal and the second signal, the output module 602 is further used to:

If both the first signal and the second signal pass the validity detection, obtaining a first amplitude with a maximum amplitude in the first signal and a second amplitude with a maximum amplitude in the second signal;

When the signal distance of the first amplitude and the signal distance of the second amplitude are both less than the preset distance, the signal distance of the first amplitude and the signal distance of the second amplitude are weighted, and the signal distance value obtained after the weighted processing is output, and the second target value includes the signal distance value obtained after the weighted processing.

Optionally, the output module 602 is further used for:

determining a first target value according to the first amplitude and a signal distance of the first amplitude;

determining a second target value according to the second amplitude and a signal distance of the second amplitude;

Determining a third target value according to the first target value and the second target value;

determining a fourth target value according to the first amplitude and the second amplitude;

The signal distance value obtained after the weighted processing is determined according to the third target value and the fourth target value.

Optionally, the preset contrast value is the product of the background noise and a preset signal-to-noise ratio.

The laser detection device of the embodiment of the present application is applied to the dual-path detection laser radar system as shown in FIG1 .

In addition, it should be noted that the laser detection device provided in the embodiment of the present application can implement the entire technical process of the above-mentioned laser detection method and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

Optionally, as shown in Figure 7, an embodiment of the present application also provides an electronic device 700, including a processor 701 and a memory 702, and the memory 702 stores programs or instructions that can be executed on the processor 701. When the program or instructions are executed by the processor 701, the various steps of the above-mentioned laser detection method embodiment are implemented and the same technical effect can be achieved. To avoid repetition, they are not repeated here.

It should be noted that the electronic devices in the embodiments of the present application include mobile electronic devices and non-mobile electronic devices.

An embodiment of the present application also provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, each process of the above-mentioned laser detection method embodiment is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

The processor is the processor in the electronic device described in the above embodiment. The readable storage medium includes a computer readable storage medium, such as ROM, RAM, magnetic disk or optical disk.

It should be noted that, in this article, the term "comprises", "includes" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "including one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the method and device in the embodiment of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a computer software product, which is stored in a storage medium (such as ROM/RAM, a magnetic disk, or an optical disk), and includes a number of instructions for enabling a terminal (which can be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to execute the methods described in each embodiment of the present application.

The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims (10)

1. A laser detection method applied to a laser radar system, the laser radar system comprising an optical transmitter and an optical receiver, the optical receiver comprising a first array of avalanche photodiodes APD and a second array of APDs, the method comprising:

acquiring a first signal acquired by the first array APD, a second signal acquired by the second array APD and a target amplitude with the largest amplitude in the first signal and the second signal;

Under the condition that the target amplitude is larger than a preset contrast value, determining a signal with the target amplitude as a target signal from the first signal and the second signal, detecting the validity of the target signal, and outputting a first target value based on the result of the validity detection of the target signal, wherein the first target value is used for representing a laser signal; or alternatively

And under the condition that the target amplitude is smaller than or equal to the preset contrast value, carrying out validity detection on the first signal and the second signal, and outputting a second target value based on the validity detection result of the first signal and the second signal, wherein the second target value is used for representing a laser signal.

2. The laser detection method according to claim 1, wherein validity detection is performed on a signal to be detected, wherein the signal to be detected is any one of the first signal, the second signal, and the target signal; the detecting the validity of the signal to be detected comprises the following steps:

Acquiring a preset detection value;

Randomly selecting continuous M signal points from the signal to be detected, and acquiring the amplitude values of the M signal points, wherein M is a positive integer greater than 2;

Comparing the amplitude values of the M signal points with the preset detection value;

and under the condition that the amplitudes of the M signal points are larger than the preset detection value, the signal to be detected is detected through the validity.

3. The laser detection method according to claim 2, wherein, in the case where the signal to be detected is the target signal, the outputting of the first target value based on the result of the validity detection of the target signal includes:

And if the target signal passes the validity detection, outputting a signal distance and/or a gray value of the target amplitude, wherein the first target value comprises the signal distance and/or the gray value of the target amplitude.

4. The laser detection method according to claim 2, wherein in the case where the signal to be detected is the first signal and the second signal, the outputting of the second target value based on the result of the validity detection of the first signal and the second signal includes:

If the first signal and the second signal pass through the validity detection, a first amplitude value with the largest amplitude value in the first signal and a second amplitude value with the largest amplitude value in the second signal are obtained;

And under the condition that the signal distance of the first amplitude and the signal distance of the second amplitude are smaller than the preset distance, carrying out weighting processing on the signal distance of the first amplitude and the signal distance of the second amplitude, and outputting a signal distance value obtained after the weighting processing, wherein the second target value comprises the signal distance value obtained after the weighting processing.

5. The laser detection method of claim 4, wherein weighting the signal distance of the first amplitude and the signal distance of the second amplitude comprises:

determining a first target value according to the first amplitude value and the signal distance of the first amplitude value;

determining a second target value according to the second amplitude value and the signal distance of the second amplitude value;

Determining a third target value according to the first target value and the second target value;

Determining a fourth target value according to the first amplitude and the second amplitude;

and determining the signal distance value obtained after the weighting processing according to the third target value and the fourth target value.

6. The laser detection method of any one of claims 1 to 5, wherein the predetermined contrast value is a product of a background noise and a predetermined signal-to-noise ratio.

7. A laser detection device is applied to a laser radar system, and is characterized in that the laser radar system comprises a light emitter and a light receiver, the light receiver comprises a first array APD and a second array APD,

The laser detection device includes:

The acquisition module is used for acquiring a first signal acquired by the first array APD, a second signal acquired by the second array APD and a target amplitude with the largest amplitude in the first signal and the second signal;

The output module is used for determining a signal with the target amplitude as a target signal from the first signal and the second signal under the condition that the target amplitude is larger than a preset contrast value, detecting the validity of the target signal, and outputting a first target value based on the result of the validity detection of the target signal, wherein the first target value is used for representing a laser signal; or alternatively

The output module is configured to perform validity detection on the first signal and the second signal when the target amplitude is less than or equal to the preset contrast value, and output a second target value based on a result of validity detection on the first signal and the second signal, where the second target value is used to characterize a laser signal.

8. The laser detection device according to claim 7, wherein, the laser detection device further comprises a detection module, wherein the detection module is used for:

Acquiring a preset detection value;

Randomly selecting continuous M signal points from a signal to be detected, and acquiring the amplitude values of the M signal points, wherein M is a positive integer greater than 2, and the signal to be detected is any one of the first signal, the second signal and the target signal;

Comparing the amplitude values of the M signal points with the preset detection value,

And under the condition that the amplitudes of the M signal points are larger than the preset detection value, the signal to be detected is detected through the validity.

9. An electronic device comprising a processor and a memory storing a program or instructions executable on the processor, which when executed by the processor, implement the steps of the laser detection method of any one of claims 1 to 6.

10. A readable storage medium, characterized in that it stores thereon a program or instructions that, when executed by a processor, implement the steps of the laser detection method according to any one of claims 1 to 6.