Detection method of laser radar and laser radar

Abstract

The invention provides a detection method of a laser radar and the laser radar, and the method comprises the steps: sequentially transmitting a detection light beam through at least two transmitting units, enabling at least two adjacent transmissions to be transmitted by different transmitting units, and enabling the receiving analysis regions of the two adjacent transmissions to be at least partially overlapped; and receiving echoes of the detection light beams through at least two receiving units to obtain echo information. The method can improve the frame rate, and guarantees the distance measurement range of the radar system.

Description

Technical Field

[0001] The present application relates to the field of laser radar, and in particular to a laser radar detection method and a laser radar. Background Art

[0002] LiDAR consists of a transmitting system, a receiving system, a scanning control system, and a data processing system. It measures distance by measuring the time difference between the emitted detection laser and the received echo laser. It has the advantages of high resolution, high sensitivity, strong anti-interference ability, and is not affected by lighting conditions. It has been widely used in autonomous driving, logistics vehicles, robots, vehicle-road collaboration, and public smart transportation.

[0003] The frame rate and ranging range of LiDAR are both very important indicators. How to improve the frame rate while ensuring the ranging range of the radar system has become an urgent problem to be solved. Summary of the invention

[0004] The present application provides a laser radar detection method and a laser radar, which can improve the frame rate while ensuring the ranging range of the radar system.

[0005] In a first aspect, the present application provides a laser radar detection method, comprising:

[0006] The detection light beam is emitted in sequence by at least two emission units, wherein at least two adjacent emissions are emitted by different emission units, and the receiving and analyzing areas of the two adjacent emissions at least partially overlap;

[0007] The echo of the detection light beam is received respectively by at least two receiving units to obtain the echo information.

[0008] Optionally, the lengths of the receiving and analyzing regions of the at least two adjacently emitted detection light beams are different.

[0009] Optionally, a transmitting unit in the at least two transmitting units corresponds to a receiving unit in the at least two receiving units on a one-to-one basis; or,

[0010] One transmitting unit among the at least two transmitting units corresponds to at least two receiving units among the at least two receiving units; wherein at least some of the transmitting units respectively corresponding to the receiving units are identical.

[0011] Optionally, the receiving units corresponding to at least some of the transmitting units are partially identical, and the receiving units corresponding to any two adjacent transmitting units are different.

[0012] Optionally, determining a reception analysis zone duration corresponding to each of the at least two transmitting units;

[0013] According to the duration of the receiving analysis zone corresponding to each transmitting unit, the receiving unit corresponding to the transmitting unit is controlled to receive the detection light beam echo.

[0014] Optionally, the duration of the receiving analysis zone corresponding to each transmitting unit is related to the position of the detection field of view corresponding to the transmitting unit, the current application scenario and the echo information corresponding to the last transmission of the transmitting unit.

[0015] Optionally, the sequentially emitting detection light beams by at least two emitting units comprises:

[0016] Encoding the transmission time of at least two transmitting units by a pseudo-random sequence to obtain a pseudo-random transmission time sequence of the at least two transmitting units;

[0017] The at least two emission units are controlled to emit detection light beams in sequence according to the pseudo-random emission time sequence.

[0018] Optionally, encoding the transmission time of at least two transmitting units by a pseudo-random sequence to obtain the pseudo-random transmission time sequence of the at least two transmitting units includes:

[0019] A series of pseudo-random emission time sequences are generated by a linear feedback shift register;

[0020] Calculating the cross-correlation function between the series of pseudo-random transmission time sequences;

[0021] The pseudo-random transmission time sequences of the at least two transmission units are determined from the series of pseudo-random transmission time sequences according to the cross-correlation function.

[0022] Optionally, when a transmitting unit among the at least two transmitting units corresponds to at least two receiving units among the at least two receiving units, echoes of the detection beams received by the at least two receiving units are fused to obtain echo information corresponding to the detection beams emitted by the transmitting unit.

[0023] Optionally, when a receiving unit among the at least two receiving units corresponds to at least two transmitting units among the at least two transmitting units and is used to sequentially receive echoes of detection light beams emitted by the corresponding at least two transmitting units, the echoes of the detection light beams of the corresponding at least two transmitting units respectively received by the receiving unit are fused to obtain echo information corresponding to the detection light beams of the at least two transmitting units.

[0024] Optionally, the wavelengths of the two adjacent emitted lights that at least partially overlap in the receiving and analyzing area are different.

[0025] Optionally, the sequentially emitting detection light beams by at least two emitting units comprises:

[0026] For multiple transmissions whose emission directions are located within the first field of view within the detection field of view of the laser radar, the receiving and analyzing areas of two adjacent transmissions at least partially overlap;

[0027] For multiple transmissions whose emission directions are located within the second field of view within the detection field of view of the laser radar, the receiving and analyzing areas of two adjacent transmissions are staggered.

[0028] Optionally, the first field of view is located in a central area of ​​the detection field of view of the laser radar; and / or,

[0029] The second field of view is located at the edge area of ​​the detection field of view of the laser radar.

[0030] In a second aspect, the present application provides a laser radar, comprising:

[0031] At least two transmitting units are used to transmit detection light beams in sequence; wherein receiving and analyzing areas of at least some of the two adjacently transmitted detection light beams overlap at least partially;

[0032] At least two receiving units are used to receive the echo of the detection light beam to obtain echo information.

[0033] In a third aspect, the present application provides a laser radar, comprising:

[0034] Processor; and

[0035] A memory having executable codes stored thereon, which, when executed by the processor, enables the laser radar to execute any one of the laser radar detection methods.

[0036] In the embodiment of the present application, by setting the receiving and analyzing areas of the two detection light beams emitted at least partially adjacent to each other to at least partially overlap, there is no need to shorten the receiving and analyzing areas of the detection light beams under the requirement of high frame rate, so as to take into account the requirements of the laser radar for high frame rate and high ranging range; and the two detection light beams with at least partial overlap in the receiving and analyzing areas are emitted by different transmitting units, and the receiving units used to receive the two detection light beams are at least partially different, which can reduce interference between the two laser light beams. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a schematic diagram of an embodiment of a laser radar detection method of the present application;

[0038] Figure 2 is a schematic diagram of an embodiment of a laser radar detection method of the present application;

[0039] Figure 3is a schematic diagram of an embodiment of a receiving and analyzing area of ​​multiple detection beams sequentially emitted by a laser radar;

[0040] Figure 4 is a schematic diagram of at least two transmitting units and at least two receiving units in a laser radar in one embodiment;

[0041] Figure 5 is a schematic diagram of an embodiment of a laser radar emitting multiple detection beams in sequence at unequal intervals;

[0042] Figure 6 is a schematic diagram of an embodiment of a laser radar in an embodiment of the present application;

[0043] Figure 7 It is a schematic diagram of an embodiment of a laser radar in an embodiment of the present application. DETAILED DESCRIPTION

[0044] The embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0045] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0046] It should be understood that although the terms "first", "second", "third", etc. may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0047] Laser radar is a radar system that emits a laser beam to detect the position, speed and other characteristic quantities of the target. Its working principle is to emit a laser beam to the target, and then calculate the time difference between the received reflected echo and the emitted laser beam, which is the flight time of the laser beam. The laser radar calculates the distance, direction and other parameters of the object reflecting the echo based on the flight time, thereby detecting the external environment. Laser radar generally includes a transceiver module and a processing module. The transceiver module converts the electrical pulse into a light pulse and transmits it, and then restores the received light pulse reflected from the target into an electrical pulse, and the processing module calculates relevant information based on the electrical pulse. Optionally, the laser radar may also include a scanning module (such as a MEMS galvanometer) for changing the emission direction of the emitted laser beam to achieve scanning of the laser beam within a certain field of view. The laser radar can be a single-channel scan, or it can achieve simultaneous or interlaced scanning of multiple channels. Optionally, in the case of multi-channel scanning, multiple groups of transceiver modules can be used to achieve mutual isolation of the optical paths (outgoing optical paths and receiving optical paths) between the channels.

[0048] The frame rate and ranging range of LiDAR are two very important indicators. Figure 1 This is a schematic diagram of the principle of the receiving and analyzing area of ​​the laser beam emitted by the laser radar. Figure 1 As shown, the times when the laser radar emits two adjacent laser beams are T0 and T1. For a laser beam emitted by the laser radar at time T0, theoretically, the maximum flight time t_dis of the laser beam is equal to the flight time t1 of the laser emission to the farthest detectable target, plus the flight time t2 required to return from the target to the laser radar, where t1=t2. Then the maximum distance of the ranging range dis_max=c*t_dis / 2, where c represents the speed of light. The larger the maximum distance of the ranging range, the longer the maximum flight time, corresponding to the longer the analysis area time required to wait for reception processing after a single laser emission. The time interval between two adjacent emissions affects the frame rate. The higher the frame rate, the shorter the interval t_freq between two adjacent emissions. For the convenience of description, the receiving analysis area of ​​the emitted laser beam is referred to as the emission time of the laser beam as the starting point, and the duration is less than or equal to the flight time corresponding to the maximum detection distance of the detection beam.

[0049] Generally, in design, in order to ensure that the laser echo emitted this time can be received and to avoid the echo signal of emission n interfering with the echo signal of emission n+1, the receiving analysis area of ​​emission n needs to be smaller than t_freq to ensure that the echo signal of emission n does not fall after emission n+1. With such a limitation, the higher the frame rate, the shorter the time interval between two adjacent measurements. The shorter the time interval between two adjacent measurements, the shorter the duration of the receiving analysis area in a single measurement. The shorter the duration of the receiving analysis area, the smaller the achievable ranging range. Therefore, the frame rate and analysis area time of the laser radar are contradictory to a certain extent. To achieve a sufficiently high frame rate, the duration of the receiving analysis area will be shortened; and to achieve a sufficiently large ranging range, the duration of the receiving analysis area needs to be increased, and the two restrict each other.

[0050] In the embodiment of the present application, by setting the receiving and analyzing areas of at least partially two adjacently emitted detection beams to at least partially overlap, it is not necessary to shorten the receiving and analyzing areas of the detection beams under the high frame rate requirement, so as to take into account the requirements of the laser radar for high frame rate and high ranging range; and the two detection beams that at least partially overlap in the receiving and analyzing areas are emitted by different emitting units, and the receiving units used to receive the two detection beams are at least partially different, which can reduce the interference between the two laser beams. The embodiments of the present application are described by way of example in conjunction with the accompanying drawings.

[0051] like Figure 2 As shown, Figure 2 : is a schematic diagram of an embodiment of a laser radar detection method of the present application. The detection method includes:

[0052] Step S201, emitting detection light beams in sequence through at least two emitting units; wherein at least two adjacent emitting units are emitted by different emitting units, and the receiving and analyzing areas of the two adjacent emitting units at least partially overlap.

[0053] Each emitting unit may include a laser emitter for emitting a beam of detection light, or may include at least two laser emitters for simultaneously emitting a beam of detection light.

[0054] like Figure 3 As shown, Figure 3 It is a schematic diagram of an embodiment of a receiving and analyzing area of ​​multiple detection beams emitted sequentially by a laser radar. Figure 3In the example shown, the laser radar includes three transmitting units E1, E2 and E3, which are used to alternately transmit detection beams in sequence. Among them, after the transmitting unit E1 transmits the detection beam at the transmitting time t1_start, t1_start to t1_end are the receiving and analyzing area of ​​the detection beam. After the transmitting unit E2 transmits at the transmitting time t2_start, t2_start to t2_end are the receiving and analyzing area of ​​the detection beam L2. After the transmitting unit E3 transmits at the transmitting time t3_start, t3_start to t3_end are the receiving and analyzing area of ​​the detection beam L3. Among them, t2_start is before t1_end, so that the receiving and analyzing areas of the detection beams of the transmitting unit E1 and the transmitting unit E2 partially overlap. Among them, t3_start is before t2_end, so that the receiving and analyzing areas of the detection beams of the transmitting unit E2 and the transmitting unit E3 partially overlap. After the transmitting unit E3 transmits the detection beam, the transmitting units E1, E2 and E3 transmit the detection beams in sequence again, and so on.

[0055] Optionally, in some examples, the receiving and analyzing areas of the detection beams emitted two adjacent times may not all overlap, or the receiving and analyzing areas of the detection beams emitted two adjacent times may all overlap. Figure 3 In the example shown, the transmitting time t3_start of the transmitting unit E3 may also be after t2_end instead of before t2_end.

[0056] Step S202: receiving the echo of the detection light beam respectively through at least two receiving units to obtain echo information.

[0057] Optionally, the number of receiving units in the laser radar can be the same as or different from the number of transmitting units, and each receiving unit is used to receive the echo of the detection beam emitted by the corresponding transmitting unit, and obtain the echo information of the received echo, such as the time of the echo, the energy of the echo, etc.

[0058] Each receiving unit corresponds to at least one transmitting unit. The number of transmitting units corresponding to different receiving units may be the same or different. In an example where a receiving unit corresponds to at least two transmitting units, since different transmitting units transmit detection beams at different times, the receiving unit maintains a receiving state in the receiving and analyzing areas of the detection beams of the corresponding at least two transmitting units.

[0059] Each transmitting unit corresponds to at least one receiving unit. The number of receiving units corresponding to each transmitting unit may be the same or different. In an example where one transmitting unit corresponds to at least two receiving units, the at least two receiving units simultaneously maintain a receiving state in a receiving and analyzing area of ​​the detection beam of the transmitting unit. Optionally, in an example where one transmitting unit corresponds to at least two receiving units, at least some of the receiving units corresponding to some of the transmitting units are identical.

[0060] like Figure 4 As shown, Figure 4 FIG. 1 is a schematic diagram of at least two transmitting units and at least two receiving units in a laser radar in one embodiment. Figure 4 In the embodiment, the at least two transmitting units and the at least two receiving units are arranged in an array. Optionally, each transmitting unit comprises a silicon photomultiplier (SiPM).

[0061] Optionally, the transmitting units in the transmitting array correspond to the receiving units in the receiving array one by one, and each receiving unit is used to receive the detection beam of the corresponding transmitting unit. Optionally, each transmitting unit in the transmitting unit array corresponds to three receiving units in the receiving array, and the receiving units corresponding to some transmitting units are partially the same. Specifically, transmitting unit 1 corresponds to receiving units 1 to 3, transmitting unit 2 corresponds to receiving units 2 to 4, transmitting unit 3 corresponds to receiving units 3 to 5, transmitting unit 4 corresponds to receiving units 4 to 6, and so on.

[0062] In an example where at least some of the transmitting units respectively correspond to the same receiving units, optionally, the transmitting units of two adjacent transmissions whose receiving and analysis areas at least partially overlap respectively correspond to different receiving units, which can reduce the crosstalk generated between the two adjacent transmissions. For example, since transmitting unit 1 and transmitting unit 2 correspond to the same receiving units, and the receiving and analysis areas of transmitting unit 1 overlap with the receiving and analysis areas of the transmitting units of the previous and next transmissions, respectively, when each transmitting unit in the transmitting unit array is controlled to transmit detection light in sequence, the transmitting units of the previous and next transmissions of transmitting unit 1 are arranged to be transmitted by other transmitting units (such as transmitting unit 4) other than transmitting unit 2. By physically isolating the transmission of the transmitting units, the crosstalk between adjacent transmissions can be further reduced while satisfying the frame rate and detection distance, thereby improving the detection accuracy.

[0063] In an optional example, the length of the receiving and analyzing area of ​​at least two adjacently emitted detection beams is preset and fixed. The length of the receiving and analyzing area of ​​each emission can be the same or different. For example, the receiving and analyzing area of ​​the detection beam of the emission unit can be a preset fixed length. For example, the receiving and analyzing areas of multiple adjacently emitted detection beams of the same emission unit can be preset receiving and analyzing areas of different lengths or the same length.

[0064] Alternatively, the receiving and analyzing area of ​​the detection beam of the transmitting unit may be variable. In one example, the detection method of the laser radar of the present application also includes: determining the receiving and analyzing area duration corresponding to each of the at least two transmitting units; and controlling the receiving unit corresponding to the transmitting unit to receive the detection beam echo according to the receiving and analyzing area duration corresponding to each transmitting unit. That is, the receiving and analyzing area of ​​at least part of the detection beam emitted by each transmitting unit is determined online, rather than being preset at the factory.

[0065] There are many methods for determining the length of the receiving and analyzing zone of the detection beam. Optionally, the length of the receiving and analyzing zone corresponding to the detection beam emitted by each transmitting unit is related to at least one of the following: the position of the detection field of view corresponding to the transmitting unit, the current application scenario, and the echo information corresponding to the last emission of the transmitting unit.

[0066] In some examples, the transmitting units at different positions in the detection field of view have different requirements for the detection distance, so the lengths of the receiving and analyzing areas of the detection beams of different transmitting units corresponding to different detection field of view positions may be different. For example, the detection requirements at the target position in the detection field of view are higher, requiring a larger ranging range, while the detection requirements at the non-target position are lower, requiring a smaller ranging range, so the receiving and analyzing area of ​​the detection beam emitted by the transmitting unit at the target position may be longer than the receiving and analyzing area of ​​the detection beam emitted by the transmitting unit at the non-target position. Optionally, the target position may be the central area of ​​the detection field of view position, and the non-target position may be the edge area of ​​the detection field of view position.

[0067] In some examples, the requirements for detection distance in different application scenarios are different, so the length of the receiving and analyzing area of ​​the detection beam of the transmitting unit in different scenarios can be different. For example, in the case where the laser radar is set in a car, the detection requirements in high-speed scenarios are higher, and a larger ranging range is required, while the detection requirements in reversing scenarios are higher, and a smaller ranging range is required. Therefore, the receiving and analyzing area of ​​the detection beam emitted by the transmitting unit in the high-speed scenario can be longer than the receiving and analyzing area of ​​the detection beam emitted by the transmitting unit in the reversing scenario.

[0068] In some examples, the receiving and analyzing area of ​​the detection beam emitted by each transmitting unit this time can be determined based on the echo information of at least one detection beam before this emission and / or the echo information of the detection beam emitted by the transmitting unit last time. For example, in some application scenarios, the detection beam emitted by the transmitting unit this time and at least one detection beam emitted before this emission are likely to hit the same object, so the distance of the object can be determined based on the echo information of at least one detection beam emitted previously, and the length of the receiving and analyzing area of ​​the detection beam emitted this time is determined based on the distance, so that the length of the receiving and analyzing area of ​​the detection beam emitted this time can at least cover the time required for the echo reflected by the object. For another example, in some application scenarios, since the position of the detection field of view corresponding to the transmitting unit remains unchanged or does not change much, the detection beams emitted by the same transmitting unit twice adjacently are likely to reach the same object, so the distance of the object can be determined based on the echo information of the detection beam emitted by the transmitting unit last time, and the length of the receiving and analyzing area of ​​the detection beam emitted this time is determined based on the distance, so that the length of the receiving and analyzing area of ​​the detection beam emitted this time can at least cover the time required for the echo reflected by the object.

[0069] Optionally, in an example where the receiving and analyzing area of ​​the detection beam emitted by the transmitting unit this time is determined based on the echo information of at least one detection beam before the emission and the echo information of the detection beam emitted by the transmitting unit last time, different weights may be assigned to the echo information of each detection beam to calculate the length of the receiving and analyzing area of ​​the detection beam emitted by the transmitting unit this time. Optionally, the weight of the echo information of at least one detection beam before the emission is greater than the echo information of the detection beam emitted by the transmitting unit last time.

[0070] Optionally, in step S201, the emission of each detection beam is unequally spaced. For example, the interval between two adjacent emissions of the same emission unit is the same, but the interval between two adjacent emissions is different. For another example, the interval between two adjacent emissions of the same emission unit is also different. There are multiple ways to achieve changes in the emission time interval. For example, the transmitter in the transceiver module is provided with an emission cycle T and a randomly generated offset duration, and the offset durations corresponding to any two adjacent main laser beams are different. The offset duration can be a positive value or a negative value, and the actual emission time interval is determined by controlling the transmitter to add the offset duration to the emission cycle T. For another example, the transmitter in the transceiver module is provided with an emission cycle T, and the different durations of the intervals between two adjacent emissions are achieved by controlling the transmitter to regularly increase or decrease a fixed duration on the basis of the emission cycle T within a period of time.

[0071] like Figure 5 As shown, Figure 5It is a schematic diagram of an embodiment of a laser radar emitting multiple detection beams in sequence at unequal intervals. Figure 5 In the example shown, the interval between the emission moment Pixel1_t1_start of the emission unit E1 and the emission moment Pixel2_t1_start of the emission unit E2 is different from the interval between Pixel2_t1_start and the emission moment Pixel3_t1_start of the emission unit E3. Optionally, the time interval between two adjacent emissions of the emission unit E1 (e.g., Pixel1_t1_start and Pixel1_t2_start), the time interval between two adjacent emissions of the emission unit E2 (e.g., Pixel2_t1_start and Pixel2_t2_start), and the time interval between two adjacent emissions of the emission unit E3 (e.g., Pixel3_t1_start and Pixel3_t2_start) are all different. Optionally, the emission units E1, E2, and E3 emit detection beams at different periods.

[0072] Since the receiving and analyzing areas of two adjacent transmissions are at least partially overlapped, crosstalk may occur between the transmissions of which the receiving and analyzing areas are at least partially overlapped. There are many ways to solve the crosstalk. In an optional example, the wavelengths of the light emitted by the two adjacent transmissions of which the receiving and analyzing areas are at least partially overlapped are different, and each transmission and reception are made to correspond by distinguishing the wavelengths. In another optional example, when the detection beam is emitted in sequence by at least two transmitting units in step S201, the emission time of the at least two transmitting units is encoded by a pseudo-random sequence to obtain a pseudo-random emission time sequence of the at least two transmitting units; and the at least two transmitting units are controlled to emit the detection beam in sequence according to the pseudo-random emission time sequence. Through the encoding between different transmitting units, the crosstalk between different reflection units can be effectively reduced under the premise of ensuring the number of concurrent transmissions. Since the emission and reception time difference of each channel is determined by the distance of the target object, it is coherent during different measurement cycles, that is, the time of the echo signal is the same from the start of the emission, so the signal can be superimposed through multiple measurements. The crosstalk signal is incoherent, and its relative time to the transmitted signal is different in different measurement cycles. Therefore, it will become background noise after multiple superpositions. Therefore, the encoded crosstalk signal can be significantly reduced, while the real signal remains unchanged. Therefore, low crosstalk can be achieved under high concurrency conditions, thereby measuring the number of superpositions or frame rate to obtain better ranging performance.

[0073] Optionally, when encoding the transmission time of at least two transmitting units by a pseudo-random sequence to obtain the pseudo-random transmission time sequence of the at least two transmitting units, a series of pseudo-random transmission time sequences are generated by a linear feedback shift register, a cross-correlation function between the series of pseudo-random transmission time sequences is calculated, and the pseudo-random transmission time sequence of the at least two transmitting units is determined from the series of pseudo-random transmission time sequences according to the cross-correlation function. For example, after generating a series of pseudo-random transmission time sequences, the cross-correlation function between the sequences is calculated from the series of pseudo-random transmission time sequences. Select a sequence combination that satisfies the smallest cross-correlation function possible to achieve the best anti-interference effect.

[0074] In one example, when one transmitting unit corresponds to at least two receiving units, the echoes of the detection beams received by the at least two receiving units are also fused to obtain the echo information corresponding to the detection beam emitted by the transmitting unit. Figure 4 The transmitting unit 1 of the example shown is used as an example. In one example, the transmitting unit 1 corresponds to the receiving units 1 to 3. After the transmitting unit 1 transmits a detection beam, the receiving units 1 to 3 simultaneously enter the detection state to receive the echo of the detection beam. After the echoes received by the receiving units 1 to 3 are fused into a larger echo, the echo information corresponding to the detection beam emitted by the transmitting unit is determined based on the fused echo.

[0075] In one example, when a receiving unit corresponds to at least two transmitting units and is used to sequentially receive the echoes of the detection beams emitted by the at least two transmitting units, the echoes of the detection beams of the at least two transmitting units respectively received by the receiving unit are fused to obtain the echo information corresponding to the detection beams of the at least two transmitting units. Figure 4 The receiving unit 3 of the example shown is used as an example. In one example, the receiving unit 3 corresponds to the transmitting units 1 to 3, that is, when the transmitting units 1 to 3 sequentially transmit three detection beams, the receiving unit 3 is in a receiving state to sequentially receive the echoes of the three detection beams emitted by the transmitting units 1 to 3. When the three echoes are fused, since the starting points of the receiving and analysis areas of the three detection beams are staggered, the starting points of the receiving and analysis areas of the three echoes are first aligned, and then the three echoes are fused into one echo on the aligned time axis, and then the echo information corresponding to the detection beam emitted by the transmitting unit is determined based on the fused echo and the aligned time axis.

[0076] In the above examples, the echo information is detected after the echoes of the detection light beams emitted by the transmitting unit are fused by at least two receiving units corresponding to the transmitting unit, or the echo information is detected after the echoes of the detection light beams continuously emitted by at least two transmitting units are fused by the receiving unit. In this way, multiple energies can be superimposed and the superposition result can be used to detect the target, which can improve the detection capability of targets with weak reflectivity, improve the dynamic range of lidar detection, and thus improve the detection accuracy; and the presentation effect of reflectivity can be improved, so that the distinction of energy integration is higher.

[0077] In one example, the above-mentioned laser radar detection method (that is, the method of overlapping the receiving and analysis areas of adjacent light beams) can be selected to be turned on or off. For example, the laser radar is installed on a moving object (such as a car) and receives instructions from a control system on the moving object. The instruction can instruct the laser radar to choose to turn on or off the above-mentioned laser radar detection method. For example, in a long-distance detection scenario, such as a car on a highway, the laser radar can automatically or according to the received instructions turn on the function of overlapping the receiving and analysis areas, and execute the above-mentioned laser radar detection method; in some close-range detection scenarios, the laser radar does not require a very high detection point frequency, and can automatically or according to the received instructions turn off the function of overlapping the receiving and analysis areas, and does not execute the above-mentioned laser radar detection method.

[0078] In one example, the above-mentioned laser radar detection method (that is, the method of overlapping the receiving and analyzing areas of adjacent light beams) can be used only for part of the detection field of view of the laser radar. For example, the detection field of view of the laser radar includes a first field of view range and a second field of view range. For multiple transmissions of the first field of view range whose emission direction is located within the detection field of view of the laser radar, the receiving and analyzing areas of two adjacent transmissions at least partially overlap. For multiple transmissions of the second field of view range whose emission direction is located within the detection field of view of the laser radar, the receiving and analyzing areas of two adjacent transmissions are staggered with each other. The first field of view range can also be the area of ​​interest of the detection field of view of the laser radar, which can be fixed in advance or the area of ​​interest determined by the laser radar for this detection based on at least one previous detection. Optionally, the first field of view range is located in the central area of ​​the detection field of view of the laser radar. Optionally, the second field of view range is located in the edge area of ​​the detection field of view of the laser radar.

[0079] The present application also provides a laser radar, such as Figure 6 As shown, Figure 66 is a schematic diagram of an embodiment of a laser radar in an embodiment of the present application. The laser radar 60 includes a transmitting module 61 and a receiving module 62. The transceiver module 61 includes at least two transmitting units for sequentially transmitting detection beams; wherein the receiving and analysis areas of at least some of the two adjacently transmitted detection beams overlap at least partially. The receiving module 62 includes at least two receiving units for receiving the echo of the detection beam to obtain echo information.

[0080] Optionally, the lengths of the receiving and analyzing regions of the at least two adjacently emitted detection light beams are different.

[0081] Optionally, a transmitting unit in the at least two transmitting units corresponds to a receiving unit in the at least two receiving units on a one-to-one basis; or,

[0082] One transmitting unit among the at least two transmitting units corresponds to at least two receiving units among the at least two receiving units; wherein at least some of the transmitting units respectively corresponding to the receiving units are identical.

[0083] Optionally, the receiving units corresponding to at least some of the transmitting units are partially identical, and the receiving units corresponding to any two adjacent transmitting units are different.

[0084] Optionally, the laser radar also includes a control module for determining the duration of a receiving and analysis zone corresponding to each of the at least two transmitting units, and controlling a receiving unit corresponding to the transmitting unit to receive the detection beam echo according to the duration of the receiving and analysis zone corresponding to each transmitting unit.

[0085] Optionally, the duration of the receiving analysis zone corresponding to each transmitting unit is related to the position of the detection field of view corresponding to the transmitting unit, the current application scenario and the echo information corresponding to the last transmission of the transmitting unit.

[0086] Optionally, when the transmitting module transmits the detection light beam in sequence through at least two transmitting units, it is specifically used to:

[0087] Encoding the transmission time of at least two transmitting units by a pseudo-random sequence to obtain a pseudo-random transmission time sequence of the at least two transmitting units;

[0088] The at least two emission units are controlled to emit detection light beams in sequence according to the pseudo-random emission time sequence.

[0089] Optionally, when the transmitting module encodes the transmission time of at least two transmitting units by using a pseudo-random sequence to obtain the pseudo-random transmission time sequence of the at least two transmitting units, it is specifically used to:

[0090] A series of pseudo-random emission time sequences are generated by a linear feedback shift register;

[0091] Calculating the cross-correlation function between the series of pseudo-random transmission time sequences;

[0092] The pseudo-random transmission time sequences of the at least two transmission units are determined from the series of pseudo-random transmission time sequences according to the cross-correlation function.

[0093] Optionally, the laser radar also includes a processing module for fusing the echoes of the detection beams received by the at least two receiving units when a transmitting unit among the at least two transmitting units corresponds to at least two receiving units among the at least two receiving units, so as to obtain echo information corresponding to the detection beam emitted by the transmitting unit.

[0094] Optionally, the laser radar also includes a processing module, which is used for fusing the echoes of the detection beams of the at least two transmitting units respectively received by the receiving unit when a receiving unit among the at least two receiving units corresponds to at least two transmitting units among the at least two transmitting units and is used for sequentially receiving the echoes of the detection beams emitted by the corresponding at least two transmitting units, so as to obtain the echo information corresponding to the detection beams of the at least two transmitting units.

[0095] Optionally, the wavelengths of the two adjacent emitted lights that at least partially overlap in the receiving and analyzing area are different.

[0096] Optionally, when the transmitting module transmits the detection light beam in sequence through at least two transmitting units, for multiple transmissions in a first field of view range whose emission direction is within the detection field of view of the laser radar, the receiving and analysis areas of two adjacent transmissions at least partially overlap;

[0097] For multiple transmissions whose emission directions are located within the second field of view within the detection field of view of the laser radar, the receiving and analyzing areas of two adjacent transmissions are staggered.

[0098] Optionally, the first field of view range is located in a central area of ​​the detection field of view of the laser radar.

[0099] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated again here.

[0100] The present application also provides a laser radar, such as Figure 7 As shown, Figure 7 Schematic diagram of an embodiment of a laser radar in the embodiment of the present application. The electronic device 70 includes a memory 71 and a processor 72 .

[0101] The processor 72 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0102] The memory 71 may include various types of storage units, such as system memory, read-only memory (ROM) and permanent storage devices. Among them, ROM can store static data or instructions required by the processor 72 or other modules of the computer. The permanent storage device may be a readable and writable storage device. The permanent storage device may be a non-volatile storage device that does not lose the stored instructions and data even after the computer is powered off. In some embodiments, the permanent storage device uses a large-capacity storage device (such as a magnetic or optical disk, flash memory) as a permanent storage device. In some other embodiments, the permanent storage device may be a removable storage device (such as a floppy disk, an optical drive). The system memory may be a readable and writable storage device or a volatile readable and writable storage device, such as a dynamic random access memory. The system memory may store some or all instructions and data required by the processor at run time. In addition, the memory 71 may include any combination of computer-readable storage media, including various types of semiconductor storage chips (such as DRAM, SRAM, SDRAM, flash memory, programmable read-only memory), and disks and / or optical disks may also be used. In some embodiments, the memory 71 may include a readable and / or writable removable storage device, such as a laser disc (CD), a read-only digital versatile disc (such as a DVD-ROM, a double-layer DVD-ROM), a read-only Blu-ray disc, an ultra-density optical disc, a flash memory card (such as an SD card, a mini SD card, a Micro-SD card, etc.), a magnetic floppy disk, etc. The computer-readable storage medium does not contain carrier waves and transient electronic signals transmitted wirelessly or wired.

[0103] The memory 71 stores executable codes, and when the executable codes are processed by the processor 72 , the processor 72 can execute part or all of the methods described above.

[0104] In addition, the method according to the present application may also be implemented as a computer program or a computer program product, which includes computer program code instructions for executing some or all of the steps in the above method of the present application.

[0105] Alternatively, the present application can also be implemented as a computer-readable storage medium (or non-transitory machine-readable storage medium or machine-readable storage medium) on which executable code (or computer program or computer instruction code) is stored. When the executable code (or computer program or computer instruction code) is executed by a processor of an electronic device (or server, etc.), the processor executes part or all of the steps of the above-mentioned method according to the present application.

[0106] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A laser radar detection method, characterized in that: include: The detection light beam is emitted in sequence by at least two emission units, wherein at least two adjacent emission units are emitted by different emission units, and the receiving and analyzing areas of the two adjacent emission units at least partially overlap; The echo of the detection light beam is received respectively by at least two receiving units to obtain the echo information.

2. The method according to claim 1, characterized in that The lengths of the receiving and analyzing regions of the at least two adjacently emitted detection light beams are different.

3. The method according to claim 1, characterized in that: The transmitting units in the at least two transmitting units correspond to the receiving units in the at least two receiving units in a one-to-one manner; or, One transmitting unit among the at least two transmitting units corresponds to at least two receiving units among the at least two receiving units; wherein, the receiving units corresponding to at least some of the transmitting units are partially identical.

4. The method according to claim 1, characterized in that Determine a reception analysis zone duration corresponding to each of the at least two transmitting units; According to the duration of the receiving analysis zone corresponding to each transmitting unit, the receiving unit corresponding to the transmitting unit is controlled to receive the detection light beam echo.

5. The method according to claim 4, characterized in that The duration of the receiving analysis zone corresponding to each transmitting unit is related to the position of the detection field of view corresponding to the transmitting unit, the current application scenario, and the echo information corresponding to the last transmission of the transmitting unit.

6. The method according to claim 1, characterized in that The method of sequentially emitting detection light beams by at least two emitting units comprises: Encoding the transmission time of at least two transmitting units by a pseudo-random sequence to obtain a pseudo-random transmission time sequence of the at least two transmitting units; The at least two emission units are controlled to emit detection light beams in sequence according to the pseudo-random emission time sequence.

7. The method according to claim 6, characterized in that The step of encoding the transmission time of at least two transmitting units by a pseudo-random sequence to obtain a pseudo-random transmission time sequence of the at least two transmitting units comprises: A series of pseudo-random emission time sequences are generated by a linear feedback shift register; Calculating the cross-correlation function between the series of pseudo-random transmission time sequences; The pseudo-random transmission time sequences of the at least two transmission units are determined from the series of pseudo-random transmission time sequences according to the cross-correlation function.

8. The method according to claim 3, characterized in that When a transmitting unit among the at least two transmitting units corresponds to at least two receiving units among the at least two receiving units, echoes of the detection beams received by the at least two receiving units are fused to obtain echo information corresponding to the detection beams emitted by the transmitting unit.

9. The method according to claim 3, characterized in that: When a receiving unit among the at least two receiving units corresponds to at least two transmitting units among the at least two transmitting units and is used to sequentially receive echoes of detection beams emitted by the corresponding at least two transmitting units, the echoes of the detection beams of the corresponding at least two transmitting units respectively received by the receiving unit are fused to obtain echo information corresponding to the detection beams of the at least two transmitting units.

10. The method according to any one of claims 1 to 9, characterized in that: The wavelengths of the two adjacent emitted lights that at least partially overlap the receiving and analyzing areas are different.

11. The method according to any one of claims 1 to 9, characterized in that: The method of sequentially emitting detection light beams by at least two emitting units comprises: For multiple transmissions whose emission directions are located within the first field of view within the detection field of view of the laser radar, the receiving and analyzing areas of two adjacent transmissions at least partially overlap; For multiple transmissions whose emission directions are located within the second field of view within the detection field of view of the laser radar, the receiving and analyzing areas of two adjacent transmissions are staggered.

12. The method according to claim 11, characterized in that The first field of view is located in the central area of ​​the detection field of view of the laser radar; and / or, The second field of view is located at the edge area of ​​the detection field of view of the laser radar.

13. A laser radar, characterized in that: include: At least two transmitting units are used to transmit detection light beams in sequence; wherein receiving and analyzing areas of at least some of the two adjacently transmitted detection light beams overlap at least partially; At least two receiving units are used to receive the echo of the detection light beam to obtain echo information.

14. A laser radar, characterized in that: include: processor; as well as A memory having executable codes stored thereon, which, when executed by the processor, enables the laser radar to execute the detection method of the laser radar as described in any one of claims 1 to 12.

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