Laser radar anti-interference method and device and electronic equipment

Abstract

The invention discloses a laser radar anti-interference method, a laser radar anti-interference device, electronic equipment and a computer readable storage medium. The method comprises the following steps: determining an emission coding value set of each emission unit of the laser radar, the emission coding value sets satisfying preset correlation conditions, including an autocorrelation condition and / or a cross-correlation condition; according to the emission coding value set of each emission unit, emission of the detection light beams of each emission unit in each emission period is controlled, and original point cloud data is obtained; and performing first filtering processing and / or second filtering processing on the original point cloud data to obtain interference-free point cloud data. According to the scheme, the detection accuracy of the laser radar can be improved.

Description

Technical Field

[0001] The present application belongs to the field of laser detection technology, and in particular relates to a laser radar anti-interference method, a laser radar anti-interference device, an electronic device and a computer-readable storage medium. Background Art

[0002] LiDAR is a mainstream radar sensor that mainly obtains point cloud data through the echo of the emitted laser to detect objects in the environment. However, for multi-line LiDAR, the multiple laser beams it emits may interfere with each other, affecting the obtained point cloud data and reducing the detection accuracy of LiDAR. Summary of the invention

[0003] The present application provides a laser radar anti-interference method, a laser radar anti-interference device, an electronic device and a computer-readable storage medium, which can improve the detection accuracy of the laser radar.

[0004] In a first aspect, the present application provides a laser radar anti-interference method, comprising:

[0005] Determine a set of transmission code values ​​of each transmission unit of the laser radar, wherein each set of transmission code values ​​satisfies a preset autocorrelation condition;

[0006] According to the emission code value set of each emission unit, the emission of the detection beam of each emission unit in each emission cycle is controlled to obtain the original point cloud data;

[0007] The original point cloud data is subjected to a first filtering process and / or a second filtering process to obtain interference-free point cloud data.

[0008] In a second aspect, the present application provides a laser radar anti-interference method, comprising:

[0009] Determine a set of emission code values ​​of each emission unit of the laser radar, wherein there are parallel emission units among the emission units, and the emission code value sets of any two of the parallel emission units satisfy a preset cross-correlation condition, and the parallel emission units refer to emission units that are emitted simultaneously in the same detection cycle;

[0010] According to the emission code value set of each emission unit, the emission of the detection beam of each emission unit in each emission cycle is controlled to obtain the original point cloud data;

[0011] The original point cloud data is subjected to a first filtering process and / or a second filtering process to obtain interference-free point cloud data.

[0012] In a third aspect, the present application provides a laser radar anti-interference device, comprising:

[0013] A coding value determination module, used to determine a set of transmission coding values ​​of each transmitting unit of the laser radar, wherein each set of transmission coding values ​​satisfies a preset autocorrelation condition;

[0014] An emission control module, used to control the emission of the detection beam of each emission unit in each emission cycle according to the emission code value set of each emission unit, so as to obtain the original point cloud data;

[0015] The filtering module is used to perform a first filtering process and / or a second filtering process on the above-mentioned original point cloud data to obtain interference-free point cloud data.

[0016] In a fourth aspect, the present application provides a laser radar anti-interference device, comprising:

[0017] A coding value determination module, used to determine a set of transmission coding values ​​of each transmission unit of the laser radar, wherein there are parallel transmission units in the above-mentioned transmission units, and the transmission coding value sets of any two of the above-mentioned parallel transmission units satisfy a preset cross-correlation condition, and the parallel transmission units refer to transmission units that transmit simultaneously in the same detection cycle;

[0018] An emission control module, used to control the emission of the detection beam of each emission unit in each emission cycle according to the emission code value set of each emission unit, so as to obtain the original point cloud data;

[0019] The filtering module is used to perform a first filtering process and / or a second filtering process on the above-mentioned original point cloud data to obtain interference-free point cloud data.

[0020] In a fifth aspect, the present application provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method in the first aspect and / or the second aspect when executing the computer program.

[0021] In a sixth aspect, the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method of the first aspect and / or the second aspect are implemented.

[0022] In a seventh aspect, the present application provides a computer program product, which includes a computer program. When the computer program is executed by one or more processors, it implements the steps of the method of the first aspect and / or the second aspect.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The technical solution of the present application determines the emission code value set of each transmitting unit of the laser radar, wherein each emission code value set satisfies the preset autocorrelation condition; according to the emission code value set of each transmitting unit, controls the emission of the detection beam of each transmitting unit in each emission cycle to obtain the original point cloud data; performs the first filtering process and / or the second filtering process on the original point cloud data to obtain interference-free point cloud data. In this way, by determining the corresponding emission code value set for each transmitting unit, and the emission code value set satisfies the preset correlation condition. At the same time, by filtering the original point cloud data, the noise points in the original point cloud data are removed, and finally the interference-free point cloud data is obtained. It can ensure that each transmitting unit effectively reduces the echo signal crosstalk phenomenon when transmitting in multiple different emission cycles, thereby improving the detection accuracy of the radar; further, by comprehensively considering various emission strategies to set the emission code of each transmitting unit, and filtering the echo data at the same time, it can ensure that no matter what emission strategy the laser radar adopts to transmit the detection beam, its echo signal crosstalk degree can be controlled at a low level, further improving the accuracy of radar detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 It is a schematic diagram of the implementation process of the laser radar anti-interference method provided in the embodiment of the present application;

[0027] Figure 2 It is a schematic diagram of the working principle of the MEMS laser radar provided in the embodiment of the present application;

[0028] Figure 3 This is a planar example diagram of a point cloud corresponding to a transmitting unit of a MEMS laser radar provided in an embodiment of the present application;

[0029] Figure 4 It is another schematic diagram of the implementation process of the laser radar anti-interference method provided in the embodiment of the present application;

[0030] Figure 5 is a structural example diagram of a mechanical laser radar provided in an embodiment of the present application;

[0031] Figure 6 This is an example diagram of a transmission array of a flash laser radar in a parallel transmission scenario provided in an embodiment of the present application;

[0032] Figure 7 It is another implementation flow diagram of the laser radar anti-interference method provided in the embodiment of the present application;

[0033] Figure 8 This is an example diagram of a transmitting array and a receiving array of a flash laser radar in a serial transmission scenario provided in an embodiment of the present application;

[0034] Fig. 9 It is another implementation flow diagram of the laser radar anti-interference method provided in the embodiment of the present application;

[0035] Fig.10 is a structural block diagram of a laser radar anti-interference device provided in an embodiment of the present application;

[0036] Fig.11 It is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0037] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0038] In order to illustrate the technical solution proposed in this application, a specific embodiment is provided below for illustration.

[0039] First, the execution subject involved in the embodiment of the present application is introduced. The laser radar anti-interference method provided in the embodiment of the present application can be executed by an electronic device, and the electronic device can be configured or connected with a laser radar. As an example only, the electronic device can be a terminal device such as a mobile phone, a laptop computer or a tablet computer; or, the electronic device can also be a vehicle-mounted device, which is not limited here.

[0040] Based on the electronic device provided above, the laser radar anti-interference method provided in the embodiment of the present application is described below. The laser radar anti-interference method specifically focuses on: the combination of the technical solution of each individual scanning unit performing a single shot and the technical solution of point cloud filtering; it can be understood that the single shot here refers to: the emission performed by each scanning unit at different times (that is, different emission cycles).

[0041] See also Figure 1 , the laser radar anti-interference method includes:

[0042] Step 101, determining a set of transmission coding values ​​of each transmitting unit of the laser radar, wherein each set of transmission coding values ​​satisfies a preset autocorrelation condition.

[0043] In the embodiment of the present application, the laser radar can emit a laser beam, that is, a detection beam. When the detection beam is reflected by an object in the environment, the laser radar can obtain an echo signal, thereby realizing the detection of the object in the environment. Considering the interference caused to the laser radar by the crosstalk of the echo signal, the electronic device can consider setting a corresponding set of emission code values ​​for each emission unit of the laser radar.

[0044] It can be understood that for any transmitting unit of the laser radar, the detection cycle T includes N transmitting cycles t, that is, each transmitting unit will perform N transmissions within one detection cycle T. Among them, each detection cycle is preset with a reference time. As an optional method, the time difference of the reference time of adjacent transmitting cycles is the same. Based on the concept of the reference time, the set of transmission code values ​​is a set of transmission code values, and the transmission code value is used to represent the delay of the transmission time of the transmitting unit relative to the reference time.

[0045] In order to ensure the anti-interference capability of each transmitting unit in a single-shot application scenario, the transmission coding value set of each transmitting unit of the laser radar should meet the preset autocorrelation condition. The autocorrelation condition is mainly to keep the autocorrelation coefficient of the transmission coding value set within a small range; that is, the autocorrelation between each transmission coding value in the same transmission coding value set is less than the preset threshold.

[0046] Step 102, according to the emission code value set of each emission unit, control the emission of the detection light beam of each emission unit in each emission cycle to obtain original point cloud data.

[0047] In the embodiment of the present application, it can be known from the characteristics of the emission code value set that each emission unit satisfies a small autocorrelation at different emission times, and thus the interference caused by echo signal crosstalk to the single-shot application scenario of the laser radar scanning unit has been eliminated to a certain extent through step 101. The electronic device can control each emission unit to emit a detection beam in each emission cycle based on the corresponding emission code value set. It can be understood that for any emission unit, since the autocorrelation of the emission code value set of the emission unit is very small, there will be no echo signal crosstalk between the i-th emission and the i+1-th emission of the reflection unit.

[0048] By repeatedly executing steps 101 and 102 in each detection cycle, the electronic device can obtain point cloud data corresponding to the environment in which the laser radar is located. Considering that the point cloud data will be further processed later, for the sake of distinction, the point cloud data obtained by the laser radar is recorded as raw point cloud data here.

[0049] Step 103: Perform a first filtering process and / or a second filtering process on the original point cloud data to obtain interference-free point cloud data.

[0050] In the embodiment of the present application, two filtering processing methods are proposed, namely the first filtering processing and the second filtering processing. It can be understood that for any test point in the original point cloud data, as long as the test point is determined to be valid through any filtering processing method, the test point can be retained; on the contrary, if the test point is determined to be invalid through both filtering processing methods, the test point is considered to be a noise point and needs to be removed.

[0051] In order to avoid waste of resources and improve the efficiency of filtering processing, the test point can be first detected by a filtering processing method (that is, the first filtering processing is performed); if the first filtering processing determines that the test point is valid, the test point is retained and there is no need to perform another filtering processing on the test point; conversely, if the first filtering processing determines that the test point is invalid, it is necessary to detect the test point by another filtering processing method (that is, perform a second filtering processing); if the second filtering processing determines that the test point is valid, the test point is retained; conversely, if the second filtering processing still determines that the test point is invalid, it is finally determined that the test point is indeed invalid, and the test point can be removed from the original point cloud data.

[0052] In some embodiments, the set of transmitted coding values ​​satisfying the autocorrelation condition may be determined in the following manner:

[0053] A1. Generate at least two pseudo-random sequences through a linear feedback shift register.

[0054] Based on the definition of a linear feedback shift register, it is known that it should have at least one input sequence. The input sequence can be set by the electronic device according to actual needs and is not limited here. Considering that the embodiment of the present application is to reduce the crosstalk of echo signals of different times of the transmitting unit, as an optional method, the values ​​in the input sequence can be different from each other. Through the continuous feedback and re-input of the linear feedback shift register, at least two pseudo-random sequences can be generated.

[0055] A2. Calculate the autocorrelation coefficient of each pseudo-random sequence based on the autocorrelation function of each pseudo-random sequence.

[0056] The electronic device may first calculate the autocorrelation coefficient of each pseudo-random sequence based on the autocorrelation function of each pseudo-random sequence. Specifically, the autocorrelation function may be obtained based on the following formula:

[0057]

[0058] Among them, ACF(a, τ) is the autocorrelation function, a i represents the i-th pseudo-random sequence, and τ is the preset time offset.

[0059] A3. Screen out a pseudo-random sequence whose autocorrelation coefficient satisfies a preset autocorrelation condition, and determine a set of transmitted code values ​​based on the screened pseudo-random sequence.

[0060] As can be seen from the foregoing, the autocorrelation condition is mainly to screen out pseudo-random sequences with autocorrelation functions as small as possible, so as to reduce the possibility of echo signal crosstalk during single transmission. As an example only, an autocorrelation coefficient threshold can be set in advance, and the autocorrelation coefficients of each pseudo-random sequence can be compared with the autocorrelation coefficient threshold to screen out pseudo-random sequences with autocorrelation coefficients less than the autocorrelation coefficient threshold; or, the first several pseudo-random sequences with the smallest autocorrelation coefficients can be directly screened out based on the autocorrelation coefficients of each pseudo-random sequence, and the screening means are not limited here. The electronic device can thus determine the set of transmission code values ​​of each transmitting unit based on the screened pseudo-random sequence.

[0061] In some embodiments, the number of transmission cycles included in a detection cycle is N, that is, the number of transmission code values ​​included in a set of transmission code values ​​is M, and the situation of N>M may occur. In view of this situation, when executing step 102, a preset number of adjacent transmissions K can be set. Then, for each transmitting unit, as long as the i-th transmission and the j-th transmission of the transmitting unit in the detection cycle satisfy ji≥K, the j-th transmission and the i-th transmission can correspond to the same transmission code value. That is, for the set of transmission code values ​​of any transmitting unit, the transmission code values ​​in the set of transmission code values ​​can be reused, but it should be noted that the time interval between the two corresponding transmission cycles when reused should be greater than the preset time length, that is, the time interval is long enough. In this way, the problem of insufficient analysis area can be effectively solved, while reducing the coding burden of electronic equipment.

[0062] The solution for the single-shot application scenario proposed in the embodiment of the present application can be understood through the following examples:

[0063] In one application scenario, the laser radar may be a mechanical laser radar. Usually, the mechanical laser radar has multiple transmitting boards, and each transmitting board has multiple transmitting units. The working principle of the mechanical laser radar is as follows: the optical system is driven by a motor to rotate, so that each transmitting unit can rotate a preset angle, for example, 360 degrees; each time the laser radar completes a scan of a preset angle, it completes a scan of a detection cycle. Based on the technical solution for the single-shot application scenario proposed above, it can be known that for the mechanical laser radar, when each transmitting unit performs a transmission, there will be a corresponding transmission code value, and the transmission code value is the delay value of the transmission time relative to the reference time. It can be understood that for the mechanical laser radar, the transmission code value corresponding to the reference time within the preset number of adjacent transmissions of a transmitting unit should not be equal. Among them, the preset number of adjacent transmissions K is related to the transmission frequency of the mechanical laser radar and the rotation speed of the mechanical laser radar. At the same time, in order to further ensure that the echo signal crosstalk phenomenon that occurs in the single-shot application scenario of the mechanical laser radar is reduced, the autocorrelation coefficient of the transmission code value of the transmitting unit in a detection cycle is less than the autocorrelation coefficient threshold.

[0064] As an example only, assume that the mechanical laser radar has a total of L transmitting boards, each transmitting board has O transmitting units, and the corresponding detection period is T, wherein any transmitting unit completes N transmissions within one detection period T, and the number of transmission coding values ​​in the transmission coding value set of each transmitting unit is M, and each transmission coding value set satisfies the autocorrelation condition, that is, the autocorrelation coefficient is less than the autocorrelation coefficient threshold.

[0065] As an optional embodiment, assuming that M≥N, for any transmitting unit, when the transmitting unit transmits the detection beam in any transmitting cycle (for example, the kth transmitting cycle), it is only necessary to randomly select a transmitting code value from the transmitting code value set corresponding to the transmitting unit (wherein the transmitting code value is different from the transmitting code values ​​corresponding to the previous k-1 transmitting cycles). In this way, the N transmissions of the transmitting unit in the detection cycle will correspond to N different transmitting code values, and the autocorrelation coefficients of these N transmitting code values ​​are very small.

[0066] As another optional embodiment, assuming that M is less than <N, then for any transmitting unit, when it transmits the detection beam from the ith transmitting cycle to the i+K-1th transmitting cycle, the transmitting code values ​​extracted from the transmitting code value set should be different from each other, and K is the preset number of adjacent transmitting times proposed above; but the ith scanning cycle and the i+kth transmitting cycle may correspond to the same transmitting code value. For example, assuming that K is 48, the 1st to 48th transmitting of the transmitting unit correspond to different transmitting code values ​​in the transmitting code value set; the 1st transmitting and the 49th transmitting may correspond to the same transmitting code value in the transmitting code value set, and similarly, the 2nd transmitting and the 50th transmitting may also correspond to the same transmitting code value in the transmitting code value set, and so on; it can be understood that the maximum value of K is M, that is, K is at most the number of transmitting code values ​​contained in the transmitting code value set.

[0067] In another application scenario, the laser radar is a micro-electro-mechanical system (MEMS) laser radar. The MEMS laser radar usually has multiple transmitting units. In a typical scenario, the positions of the multiple transmitting units are in the same straight line. As an optional form, the multiple transmitting units use a scanning optical element, such as a two-dimensional galvanometer, to achieve the splicing of multiple detection fields of view. This application does not limit the number of transmitting units, the arrangement of the transmitting units, and the number of scanning optical elements. Please refer to Figure 2 , Figure 2 An example of the working principle of the MEMS laser radar is given: the transmitting module includes multiple transmitting units, and the receiving module includes multiple receiving units; a transmitting unit in the transmitting module is scanned by a two-dimensional galvanometer, thereby detecting a point cloud corresponding to a detection field of view in the environment space, such as Figure 2 The point cloud shown on the right.

[0068] As an example only, assume that the MEMS lidar has a total of L transmitting units, and the detection period of the MEMS lidar is T, wherein any transmitting unit completes N transmissions within one detection period T, and the number of transmission coding values ​​in the transmission coding value set of each transmitting unit is M, and each transmission coding value set satisfies the autocorrelation condition, that is, the autocorrelation coefficient is less than the autocorrelation coefficient threshold.

[0069] Assuming that M≥N, for any transmitting unit, in a detection cycle, when the transmitting unit transmits the detection beam in each transmission cycle, it only needs to randomly extract a transmission code value that has not been extracted in the detection cycle. In this way, the N transmissions of the transmitting unit in the detection cycle will correspond to N different transmission code values, and the autocorrelation coefficients of these N transmission code values ​​are very small.

[0070] Assuming that M<N, for any transmitting unit, within a detection cycle, when the detection light beam is emitted from the i-th emission cycle to the i+K-1-th emission cycle, the emission coding values ​​extracted from the emission coding value set should be different from each other, and K is the preset number of adjacent emissions proposed in the previous article; but the i-th scanning cycle and the i+K-th emission cycle can correspond to the same emission coding value.

[0071] For easier understanding, see Figure 3 , Figure 3 An example of a point cloud obtained by multiple transmissions by a transmitting unit is given. Figure 3 It can be seen that the intervals between the points obtained within the preset number of adjacent transmissions are relatively small. Therefore, if the same transmission code value is used for transmission within the preset number of adjacent transmissions (for example, the transmission code value of the first transmission and the second transmission in the detection cycle is the same), it may cause a certain echo signal crosstalk. However, as long as the interval between two transmissions is far, exceeding the preset number of adjacent transmissions, even if the same transmission code value is used for the two transmissions, it will not cause too much echo signal crosstalk. For example, the first transmission of the transmitting unit obtains Figure 3 The point at the M-3th row and N-3th column in the 49th emission is Figure 3 For the point at the M+3th row and the N+3th column, since the positions of these two points are relatively far apart and the interval between the transmission cycles is also large, the first transmission and the 49th transmission can use the same transmission code value, thereby realizing the reuse of elements in the transmission code value set.

[0072] Based on this concept, when considering the problem of insufficient analysis area in high-frequency and long-distance ranging applications, electronic equipment can consider the transmission code values ​​of preset adjacent transmission times without repetition when designing the coding period. While ensuring that the coding autocorrelation coefficient is small, the maximum delay of the transmission time corresponding to each transmission relative to the absolute time can be minimized as much as possible, thereby solving the problem of insufficient analysis area in high-frequency and long-distance ranging applications.

[0073] In another application scenario, if the laser radar is an array-type (flash) laser radar, then for the flash laser radar, it is equipped with a transmitting array and a receiving array. For the transmitting array in the flash laser radar, there are multiple transmitting units in the transmitting array, and accordingly, there are also multiple receiving units in the receiving array. Similar to the above, through the setting of the autocorrelation condition, the set of emission code values ​​of any transmitting unit in the transmitting array satisfies the small autocorrelation, so that the transmitting unit will not cause the problem of echo signal crosstalk when performing a single shot (that is, when the transmitting unit transmits in multiple different emission cycles). Of course, for each transmitting unit in the flash laser radar, in order to solve the problem of insufficient analysis area, it can also consider the reuse of the emission code values ​​in the emission code value set based on the preset number of adjacent transmissions. That is, for any transmitting unit, its i-th scanning cycle and the i+K-th emission cycle can correspond to the same emission code value, wherein the value of K is related to the emission frequency of the transmitting unit and the target detection distance set by the laser radar. For details, please refer to the above description, which will not be repeated here.

[0074] Another laser radar anti-interference method provided in the embodiment of the present application is described below. The laser radar anti-interference method is mainly used to solve the problem of laser radar interference when there are parallel transmitting units in the laser radar, by combining the technical solution of concurrent control of the scanning unit with the technical solution of point cloud filtering; it can be understood that the parallel transmitting unit refers to the transmitting unit that transmits simultaneously in the same detection cycle.

[0075] See also Figure 4 , the laser radar anti-interference method includes:

[0076] Step 401, determine the emission coding value set of each emission unit of the laser radar, wherein there are parallel emission units among the above-mentioned emission units, and the emission coding value sets of any two of the above-mentioned parallel emission units satisfy a preset cross-correlation condition, and the parallel emission units refer to emission units that emit simultaneously in the same detection cycle.

[0077] To facilitate understanding, we first explain the meaning of parallel emission units with a simple example: for example, within an emission cycle, from a microscopic point of view, emission unit A actually emits a detection beam at T0+x1, emission unit B actually emits a detection beam at T0+x2, and emission unit C actually emits a detection beam at T0+x3, that is, the difference between the three is very small, and x1, x2 and x3 can also be negative numbers; that is, the emission interval when the three are emitted in the same emission cycle is very short, and these three emission times are very close to T0, so it can be approximately regarded that emission units A, B and C all emit detection beams at T0.

[0078] It can be understood that in a concurrent scenario, the transmitting units of the laser radar can usually be divided into multiple groups of concurrent transmitting units. For example, transmitting units A, B and C are one group of concurrent transmitting units, and transmitting units D, E and F are another group of concurrent transmitting units, that is, A, B and C are transmitted approximately at the same time, and D, E and F are transmitted approximately at the same time, but A, B, C and D, E and F are not transmitted approximately at the same time. Any two parallel transmitting units mentioned in this application refer to any two parallel transmitting units in the same group.

[0079] For any two parallel transmitting units, the transmission code value sets of the two parallel transmitting units should meet the preset cross-correlation condition, which is mainly to keep the cross-correlation coefficients of different transmission code value sets within a small range; that is, to make the cross-correlation coefficients between different transmission code value sets less than the preset value. For example, in the example given above, the transmission code value sets of A, B and C all meet the cross-correlation condition, so that although A, B and C are transmitted at approximately the same time, the cross-correlation of their transmission moments is small, thereby preventing the echo signal crosstalk between the parallel transmitting units.

[0080] Step 402, according to the emission code value set of each emission unit, control the emission of the detection light beam of each emission unit in each emission cycle to obtain the original point cloud data.

[0081] In the embodiment of the present application, it can be seen from the characteristics of the transmission code value set that for any two concurrent units, the mutual correlation at the same transmission time is small, so the interference caused by the echo signal crosstalk to the concurrent application scenario of the laser radar has been eliminated to a certain extent through step 401. The electronic device can control each transmitting unit to transmit the detection beam in each same transmission cycle based on the corresponding transmission code value set.

[0082] Step 403: Perform a first filtering process and / or a second filtering process on the original point cloud data to obtain interference-free point cloud data.

[0083] It can be understood that step 403 is the same as or similar to step 103. For details, please refer to the relevant description of step 103, which will not be repeated here.

[0084] In some embodiments, the set of transmitted coding values ​​satisfying the cross-correlation condition may be determined in the following manner:

[0085] B1. Generate at least two pseudo-random sequences through a linear feedback shift register.

[0086] Since this step is the same as or similar to step A1, reference may be made to the relevant description of step A1 and no further description is given here.

[0087] B2. Calculating the mutual correlation coefficient of any two pseudo-random sequences based on the mutual correlation function of the arbitrary two pseudo-random sequences.

[0088] The electronic device may first calculate the mutual correlation coefficient of each pseudo-random sequence based on the mutual correlation function of each pseudo-random sequence. Specifically, the mutual correlation function may be obtained based on the following formula:

[0089]

[0090] Among them, a i is a pseudo-random sequence, b i+τ is another pseudo-random sequence, CCF(a, b, τ) is the pseudo-random sequence a i and b i+τ is the cross-correlation function, τ is the preset time offset.

[0091] B3. Screen out a pseudo-random sequence whose mutual correlation coefficient satisfies a preset mutual correlation condition, and determine a set of transmitted coding values ​​based on the screened pseudo-random sequence.

[0092] As can be seen from the foregoing, the mutual correlation condition is mainly to screen out pseudo-random sequences with as small mutual correlation as possible, so as to reduce the possibility of echo signal crosstalk during transmission. As an example only, a mutual correlation coefficient threshold can be set in advance, and the mutual correlation coefficient of any two pseudo-random sequences can be compared with the mutual correlation coefficient threshold, so as to screen out multiple pseudo-random sequences with mutual correlation coefficients less than the mutual correlation coefficient threshold, and the screening means are not limited here. The electronic device can thus determine the transmission code value set of each parallel transmission unit based on the screened pseudo-random sequence. For example, through steps B1 to B3, three pseudo-random sequences S1, S2 and S3 are obtained, and the mutual correlation between these three pseudo-random sequences is small, then the transmission code value set of the transmission unit A can be determined based on S1, the transmission code value set of the transmission unit B can be determined based on S2, and the transmission code value set of the transmission unit C can be determined based on S3.

[0093] The solution for concurrent application scenarios proposed in the embodiments of the present application can be understood through the following examples:

[0094] In one application scenario, the laser radar may be a mechanical laser radar. Some of the related concepts of the laser radar have been explained in the previous embodiment and are not limited here. Figure 5 , Figure 5 A structural example of a mechanical laser radar is given, wherein 100 is a transmitting lens of a transmitting unit, and 300 is a transmitting board. It can generally be considered that there will be parallel transmitting units on different transmitting boards. For example, transmitting units in the same row of different transmitting boards can be parallel transmitting units.

[0095] Just as an example, let the first transmitting unit of the first transmitting board be transmitting unit A, and the first transmitting unit of the second transmitting board be transmitting unit B. Based on the scheme for determining the set of transmitting coding values ​​proposed above, it can be known that the set of transmitting coding values ​​of transmitting unit A and the set of transmitting coding values ​​of transmitting unit B need to satisfy a mutual correlation less than a preset value. It can be seen that when performing a detection cycle, the transmitting coding values ​​of the transmitting unit A and transmitting unit B satisfy a small mutual correlation, and the two will not generate mutual crosstalk during multiple transmissions in a detection cycle; and by analogy, each row of parallel transmitting units will not cause echo signal crosstalk between each other when the parallel transmitting units transmit at approximately the same time each time (that is, each time they transmit in parallel), because the mutual correlation between the corresponding sets of transmitting coding values ​​satisfies a less than preset value. Just as an example, through the operation of parallel transmission of each row of parallel transmitting units in a transmission cycle, the following can be obtained: Figure 5 The point cloud shown on the left.

[0096] In another application scenario, the laser radar is a MEMS laser radar. Some relevant concepts of the laser radar have been explained in the previous embodiment and are not limited here. As an optional example, all the transmitting units of the MEMS laser radar can be understood as a group of concurrent transmitting units, that is, all the transmitting units of the MEMS laser radar can be transmitted approximately simultaneously in the same transmission cycle. Since the sets of transmission code values ​​corresponding to any two transmitting units satisfy the cross-correlation condition, there will be no problem of echo signal crosstalk between different transmitting units (especially between adjacent transmitting units).

[0097] In another application scenario, if the laser radar is a solid-state (flash) laser radar, the flash laser radar is equipped with a transmitting array and a receiving array. Some relevant concepts of the laser radar have been explained in the previous embodiment and are not limited here. As an example, in one receiving cycle, the receiving array usually receives a whole row (column), such as Figure 8 In the flash laser radar, for each row (column), two or more transmitting units with a certain position interval in the row (column) can be regarded as a transmitting group; for each column (row), two or more transmitting units with a certain position interval in the column (row) can be regarded as parallel transmitting units.

[0098] See also Figure 6 , Figure 6 An example of flash lidar in concurrent application scenarios is given. Figure 6In the figure, the two transmitting units A0 and A6 that are in the same row and that meet the optical non-crosstalk condition in physical position are regarded as a transmitting group, recorded as the first transmitting group. The corresponding two transmitting units F0 and F6 that are in different columns and that meet the optical non-crosstalk condition in physical position are regarded as a transmitting group, recorded as the second transmitting group. Then the first transmitting group and the second transmitting group are concurrent transmitting units. That is, A0 and F0 are emitted approximately at the same time in each identical transmitting cycle, and the emission code value sets of the two satisfy the mutual correlation condition; A6 and F6 are emitted approximately at the same time in each identical transmitting cycle, and the emission code value sets of the two satisfy the mutual correlation condition.

[0099] It should be noted that at least two different emission units in one emission group emit laser beams in a time-sharing manner based on a preset rule. Figure 6 To illustrate with an example, for the first emission group, A0 is emitted first, and A6 is emitted after A0; similarly, for the second emission group, F0 is emitted first, and F6 is emitted after F0. It can be understood that the present application does not impose a unique restriction on the specific emission order of each emission group. It can be seen that the flash laser radar can avoid the echo signal crosstalk caused by simultaneous emission through the laser radar anti-interference scheme proposed in the embodiment of the present application, and can also improve the processing frame rate.

[0100] Another laser radar anti-interference method provided in the embodiment of the present application is described below. The laser radar anti-interference method specifically focuses on: the combination of the technical solution of serial transmission of the scanning unit and the technical solution of point cloud filtering; it can be understood that the serial transmission unit refers to the transmission unit that transmits in sequence according to the preset timing in the same detection cycle.

[0101] See also Figure 7 , the laser radar anti-interference method includes:

[0102] Step 701, determine the set of emission coding values ​​of each emission unit of the laser radar, wherein there are serial emission units in the above-mentioned emission units, and the difference in emission coding values ​​corresponding to the same emission of adjacent serial emission units in the same emission cycle is a preset threshold, and the above-mentioned serial emission units refer to emission units that are emitted sequentially according to a preset timing in the same detection cycle.

[0103] For ease of understanding, let's first explain the meaning of serial transmission units with a simple example: for example, in a laser radar, the positions of transmission units A, B and C are adjacent. In one transmission cycle, transmission unit A first transmits a detection beam, and then transmission unit B transmits a detection beam when the echo signal of the detection beam can be received, and so on, and then transmission unit C transmits a detection beam.

[0104] The preset threshold value can be determined according to the maximum detection distance d designed by the laser radar and the propagation speed v of the detection beam (i.e., the speed of light). Specifically, it can be determined according to the formula Calculate the longest receiving time of the echo signal. When the preset threshold is a fixed value, the longest receiving time t max , the preset threshold is set to be the difference between the encoding values ​​of the two serial transmission units, and the fixed duration is greater than the longest receiving duration t max ; When the preset threshold is an indefinite value, the maximum receiving time t max , the preset threshold is set to be used to express the difference between the two serial transmission unit code values, that is, the difference between the two serial transmission unit code values ​​is greater than the longest receiving time t max The encoding value of the change.

[0105] Step 702, according to the emission code value set of each emission unit, control the emission of the detection light beam of each emission unit in each emission cycle to obtain the original point cloud data.

[0106] In the embodiment of the present application, since the difference in the transmission coding values ​​corresponding to the same transmission of adjacent serial transmitting units in the same transmission cycle has been limited to a preset threshold, when controlling each transmitting unit to transmit in each transmission cycle, it can be ensured that the serial transmitting units are not affected by echo signal crosstalk.

[0107] Step 703: Perform a first filtering process and / or a second filtering process on the original point cloud data to obtain interference-free point cloud data.

[0108] It can be understood that step 703 is the same as or similar to step 103. For details, please refer to the relevant description of step 103, which will not be repeated here.

[0109] The solution for serial application scenarios proposed in the embodiments of the present application can be understood through the following examples:

[0110] In one application scenario, the laser radar may be a mechanical laser radar. Some relevant concepts of the laser radar have been explained in the previous embodiment and are not limited here. For the laser radar, the transmitting units on the same transmitting board can generally be considered as serial transmitting units, and in general, for a transmitting board, it is usually transmitted in sequence starting from the first transmitting unit.

[0111] As an example only, let the first transmitting unit of the first transmitting board be transmitting unit A, the second transmitting unit of the first transmitting board be transmitting unit B, and the third transmitting unit of the first transmitting board be transmitting unit C. Based on the scheme for determining the transmitting coding value set proposed in the previous article, it can be known that, assuming that within the same transmitting cycle, A can randomly extract a transmitting coding value based on the transmitting coding value set, so that it is transmitted at time T1.

[0112] In the case where the preset threshold is a fixed value, it is assumed that the duration corresponding to the preset threshold is T0, and T0 is greater than the longest receiving duration t max , then B will be transmitted at time T1+T0; correspondingly, C will be transmitted at time T1+2*T0, thereby realizing the sequential transmission of A, B and C based on a fixed duration within the same transmission cycle.

[0113] When the preset threshold is a variable value, B will transmit at time T1+T1', where T1' is the duration corresponding to one possible value of the preset threshold; C will transmit at time T1+T1'+T1", where T1" is the duration corresponding to another possible value of the preset threshold, and both T1' and T1" are greater than the longest receiving duration t max , thereby achieving sequential transmission of A, B and C based on non-fixed duration within the same transmission cycle.

[0114] In another application scenario, the laser radar is a MEMS laser radar. Some relevant concepts of the laser radar have been explained in the previous embodiment and are not limited here. When the MEMS laser radar detects close-range scenes, all the transmitting units of the MEMS laser radar can be understood as a group of serial transmitting units, that is, all the transmitting units of the MEMS laser radar can be transmitted serially in the same transmission cycle. Similar to the mechanical laser radar shown above, when performing serial transmission, if the preset threshold is a fixed value, the various transmitting units of the MEMS laser radar can be arranged in sequence based on a fixed duration and according to their positions; if the preset threshold is a variable value, the various transmitting units of the MEMS laser radar can be arranged in sequence based on an unfixed duration and according to their positions.

[0115] In another application scenario, if the laser radar is an array-type (flash) laser radar, then for the flash laser radar, it is equipped with a transmitting array and a receiving array. Some relevant concepts of the laser radar have been explained in the previous embodiment and are not limited here. As described above, two different transmitting units in a transmitting group are the concept of serial transmission, which is not repeated here. In addition, multiple transmitting groups can also be set in the same row (column).

[0116] exist Figure 8In the figure, A0 and A6 form a firing group, recorded as the first firing group; A1 and A7 form a firing group, recorded as the second firing group; A0, A1, A6 and A7 are all in the same row. Different firing groups in the same row also follow the serial firing principle. That is, in the first row, after the first firing group A0 and A6 are fired, the second firing group A1 and A7 are fired, and so on, followed by A2 and A8, and then A3 and A9, which will not be repeated here.

[0117] It can be understood that for flash laser radar, through the serial and concurrent application scenarios shown above, different emission groups in the same row can be considered as serial emission, and different emission groups in the same column can be considered as parallel emission; or different emission groups in the same column can be considered as serial emission, and different emission groups in the same row can be considered as parallel emission. Figure 6 The corresponding concurrent scenarios and Figure 8 The corresponding serial transmission scenario can be determined as follows: within one transmission cycle, the transmission group composed of A0 and A6 and the transmission group composed of F0 and F6 are parallel transmissions; then, the transmission group composed of A0 and A6 and the transmission group composed of A1 and F7 are serial transmissions, and correspondingly, the transmission group composed of F0 and F6 and the transmission group composed of F1 and F7 are serial transmissions; in addition, serial transmission is also carried out within each transmission group.

[0118] In some embodiments, when laser radar is actually used, it often combines the single-shot application scenarios, concurrent application scenarios, and serial transmission application scenarios given above. For example, for a mechanical laser radar, for any transmitting unit, the multiple transmissions it performs actually belong to a single-shot application scenario. For the transmitting units in the same row of different transmitting boards, the same transmission operation performed in the same transmission cycle actually belongs to a concurrent application scenario. For each transmitting unit on the same transmitting board, the same transmission operation performed in the same transmission cycle actually belongs to a serial transmission application scenario. It can be understood that in actual applications, for a laser radar system, there may be single-shot, parallel transmission, and serial transmission application scenarios at the same time.

[0119] Another laser radar anti-interference method provided in the embodiment of the present application is described below. Fig. 9 , Fig. 9 A laser radar anti-interference method is shown. The laser radar anti-interference method includes:

[0120] Step 901, determining a set of transmission code values ​​of each transmission unit of the laser radar, wherein each set of transmission code values ​​satisfies a preset autocorrelation condition;

[0121] Step 902: when the laser radar has multiple transmitting units, determine whether there are parallel transmitting units and / or serial transmitting units among the multiple transmitting units; and set a set of transmitting code values ​​of the parallel transmitting units and / or serial transmitting units according to a preset rule;

[0122] Step 903: If there are parallel transmitting units among the multiple transmitting units, determine the transmission coding value set of each transmitting unit in the parallel transmitting units; wherein the transmission coding value sets of any two parallel transmitting units satisfy a preset cross-correlation condition.

[0123] The parallel transmitting units refer to transmitting units that transmit simultaneously in the same detection cycle.

[0124] Step 904, if there is a serial transmitting unit in the transmitting unit of the laser radar, the difference in the transmitting code values ​​corresponding to the same transmission of adjacent serial transmitting units in the same detection cycle is a preset threshold.

[0125] The serial transmitting unit refers to a transmitting unit that transmits sequentially according to a preset timing in the same detection cycle.

[0126] Step 905, according to the emission code value set of each emission unit, control the emission of the detection light beam of each emission unit in each emission cycle to obtain the original point cloud data.

[0127] Step 906: Perform a first filtering process and / or a second filtering process on the original point cloud data to obtain interference-free point cloud data.

[0128] As can be seen from the above, for laser radar, for single-shot application scenarios, the autocorrelation condition can be considered to determine the set of emission code values ​​corresponding to each transmitting unit; for concurrent application scenarios, the cross-correlation condition can be considered to determine the set of emission code values ​​corresponding to each transmitting unit; for single-shot and concurrent application scenarios, the autocorrelation condition and the cross-correlation condition can be considered to determine the set of emission code values ​​corresponding to each transmitting unit. In addition, for serial application scenarios, the difference in emission code values ​​corresponding to the same emission of adjacent serial transmitting units in the same detection cycle can be set as a preset threshold. By comprehensively considering various emission strategies to set the emission code of each transmitting unit, it can be ensured that no matter what emission strategy the laser radar adopts to emit the detection beam, the degree of echo signal crosstalk can be controlled at a low level, further improving the accuracy of radar detection.

[0129] In the following, any point to be measured in the original point cloud data is taken as an example to illustrate the specific process of performing the first filtering process and / or the second filtering process on the original point cloud data to obtain the interference-free point cloud data.

[0130] In some embodiments, for any point to be measured in the original point cloud data, the processing process of the first filtering process is described in detail as follows:

[0131] C1. Determine a neighborhood to be measured centered on the point to be measured based on a preset neighborhood size.

[0132] C2. Calculate the difference between the distance measurement value of each point in the neighborhood to be measured except the point to be measured and the distance measurement value of the point to be measured.

[0133] Normally, in the point cloud obtained based on the target that is perpendicular to the surface and the laser radar in the 0-degree direction (horizontal or vertical), the difference in the ranging value of each point is small. Based on this, from this perspective, the difference between the ranging value of each point in the neighborhood to be measured except the point to be measured and the ranging value of the point to be measured can be calculated. It can be understood that in the M*N neighborhood, there are M*N-1 points in addition to the point to be measured. These M*N-1 points will calculate the difference in ranging values ​​with the point to be measured, thereby obtaining M*N-1 differences.

[0134] C3. Determine whether the point to be tested is valid based on the obtained difference.

[0135] As mentioned in step C2, the difference in the distance measurement value of each point in the neighborhood to be tested should be small. This can be used as a criterion to analyze the obtained M*N-1 differences to determine whether the point to be tested is valid. Specifically, in order to eliminate occasional interference and reduce the occurrence of incorrect analysis, a quantity threshold can be set in advance; then based on the quantity threshold, the validity of the point to be tested can be analyzed through the following process: the number of target differences among the M*N-1 differences obtained by counting, wherein the target difference refers to: a difference less than a preset difference threshold; if the number of target differences reaches the quantity threshold, the point to be tested is determined to be valid; conversely, if the number of target differences is less than the quantity threshold, it is necessary to combine the result of the second filtering process to determine whether the point to be tested is valid.

[0136] As an example, assume that M is 3, N is 3, and the point to be measured is P0. Then, a 3*3 neighborhood can be determined from the original point cloud with the point to be measured P0 as the center. For ease of explanation, the points in the neighborhood other than the point to be measured P0 are P1, P2, P3, P4, P5, P6, P7 and P8. When performing the first filtering process, the difference between the distance measurement value of P1 and the distance measurement value of P0 can be calculated, which is recorded as d 01 , calculate the difference between the distance measurement value of P2 and the distance measurement value of P0, recorded as d 02 , and so on, until the difference between the distance measurement value of P8 and the distance measurement value of P0 is calculated, recorded as d 08 . 01 d 02 ,……,d 08By comparing it with the preset difference threshold d, we can get d 01 d 02 ,……,d 08 There are several differences less than the difference threshold, that is, the number of target differences l is known. Assuming the number threshold is l0, when l≥l0, it can be determined that the test point is valid and the test point can be retained; when l<l0, it can be determined that the test point is invalid, and the result of the second filtering process needs to be combined to finally make a decision to retain or eliminate it.

[0137] In some embodiments, for any point to be measured in the original point cloud data, the processing process of the second filtering process is described in detail as follows:

[0138] D1. In the original point cloud data, take the point to be measured as the center and obtain at least two points in the preset direction.

[0139] Normally, in the point cloud obtained based on a target with a certain angle between the surface and the 0 degree direction (horizontal or vertical) of the laser radar, the distance values ​​of each point may differ greatly. At this time, if the first filtering process is still used, normal points may be mistakenly deleted. In view of this situation, the second filtering process is proposed as a supplement to the first filtering process.

[0140] Each point in the point cloud can be represented based on the coordinates (x, y, d); x is used to represent the horizontal displacement of the point relative to the laser radar; y is used to represent the vertical displacement of the point relative to the laser radar; d represents the depth information, that is, the ranging value. In this context, the direction mentioned in the embodiments of the present application is not actually the direction presented by each point under consideration and the point to be measured in three-dimensional space, but the direction presented by each point and the point to be measured in the two-dimensional xy plane after the point cloud under consideration is projected on the xy plane (that is, the direction presented by each point based on the x-coordinate and the y-coordinate and the point to be measured).

[0141] As an example only, the preset directions may include: horizontal direction, vertical direction and ±45 degree direction, a total of four directions. It can be imagined that these four directions form a "M" shape on the xy plane with the point to be measured as the center. Let the point to be measured be P1, and without considering the depth information, the point to be measured can be recorded as P1(x0,y0), then:

[0142] The points in the horizontal direction of the point to be measured are: ..., P2 (x0-2, y0), P3 (x0-1, y0), P4 (x0+1, y0), P5 (x0+2, y0), ...;

[0143] The points in the vertical direction of the point to be measured are: ..., P6 (x0, y0-2), P7 (x0, y0-1), P8 (x0, y0+1), P9 (x0, y0+2), ...;

[0144] The points on the +45 degree direction of the point to be measured are: ..., P10 (x0-2, y0-2), P11 (x0-1, y0-1), P12 (x0+1, y0+1), P13 (x0+2, y0+2), ...;

[0145] The points on the -45 degree direction of the point to be tested are: ..., P10 (x0-2, y0+2), P11 (x0-1, y0+1), P12 (x0+1, y0-1), P13 (x0+2, y0-2), ...

[0146] D2. Fit at least two points and the point to be measured.

[0147] When there is only one preset direction, the distance measurement values ​​of the at least two points and the point to be measured can be directly fitted.

[0148] When there are more than two preset directions, the at least two points obtained in one preset direction and the distance measurement value of the point to be measured can be fitted in sequence. For example, at least two points in the horizontal direction of the point to be measured and the distance measurement value of the point to be measured are first fitted; then at least two points in the vertical direction of the point to be measured and the distance measurement value of the point to be measured are fitted; then at least two points in the +45 degree direction of the point to be measured and the distance measurement value of the point to be measured are fitted; finally, at least two points in the -45 degree direction of the point to be measured and the distance measurement value of the point to be measured are fitted.

[0149] D3. Determine whether the test point is valid based on the fitting results.

[0150] In the point cloud obtained based on the target with a certain angle between the surface and the 0-degree direction (horizontal or vertical) of the laser radar, there should be points in a certain direction that can be fitted into a straight line. In order to save processing resources and improve processing efficiency, the embodiment of the present application only performs targeted processing based on the preset direction of the point to be measured, and detects whether the points in these preset directions can be fitted into a straight line. When the fitting result indicates that at least two points in the preset direction of step D2 and the point to be measured can be fitted into a straight line, it can be determined that the point to be measured is valid.

[0151] It should be noted that, when there are more than two preset directions, as long as the fitting result indicates that at least two points in any preset direction can be fitted into a straight line with the point to be measured, the point to be measured can be determined to be valid, and at this time, other preset directions that have not been fitted can no longer be considered; on the contrary, if the fitting result indicates that at least two points in each preset direction cannot be fitted into a straight line with the point to be measured, the point to be measured is determined to be invalid, and the result of the first filtering processing needs to be combined to finally make a decision to retain or eliminate it.

[0152] As can be seen from the above, in the embodiment of the present application, the anti-interference of the laser radar is improved from two aspects to improve the detection accuracy of the laser radar: on the one hand, from the perspective of laser emission, a corresponding emission code value set will be determined for each emission unit, and the emission code value set satisfies the preset correlation condition. Specifically, when each emission code value set satisfies the preset autocorrelation condition, for each emission unit, it can be ensured that the emission unit will not have echo signal crosstalk when transmitting in multiple different emission cycles, thereby reducing the interference suffered by the laser radar; when there are parallel emission units, that is, emission units that are emitted approximately at the same time in the same emission cycle, the emission code value sets of any two parallel emission units meet the preset cross-correlation conditions, which can ensure that these parallel emission units will not have signal crosstalk when transmitting in the same emission cycle, thereby reducing the interference suffered by the laser radar. On the other hand, from the perspective of data processing, when the original point cloud data is obtained, the original point cloud data can be filtered by one or two filtering processing methods according to the actual situation to remove the noise points in the original point cloud data, which can also reduce the interference suffered by the laser radar.

[0153] The technical solution of the present application determines the emission code value set of each transmitting unit of the laser radar, wherein each emission code value set satisfies the preset autocorrelation condition; according to the emission code value set of each transmitting unit, controls the emission of the detection beam of each transmitting unit in each emission cycle to obtain the original point cloud data; performs the first filtering process and / or the second filtering process on the original point cloud data to obtain interference-free point cloud data. In this way, by determining the corresponding emission code value set for each transmitting unit, and the emission code value set satisfies the preset correlation condition. At the same time, by filtering the original point cloud data, the noise points in the original point cloud data are removed, and finally the interference-free point cloud data is obtained. It can ensure that each transmitting unit effectively reduces the echo signal crosstalk phenomenon when transmitting in multiple different emission cycles, thereby improving the detection accuracy of the radar; further, by comprehensively considering various emission strategies to set the emission code of each transmitting unit, and filtering the echo data at the same time, it can ensure that no matter what emission strategy the laser radar adopts to transmit the detection beam, its echo signal crosstalk degree can be controlled at a low level, further improving the accuracy of radar detection.

[0154] It should be understood that the serial numbers of the steps in the above embodiments do not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0155] Corresponding to the laser radar anti-interference method provided above, the embodiment of the present application also provides a laser radar anti-interference device. Fig.10As shown, the laser radar anti-interference device 1000 includes:

[0156] The coding value determination module 1001 is used to determine a set of transmission coding values ​​of each transmission unit of the laser radar, wherein each set of transmission coding values ​​satisfies a preset autocorrelation condition;

[0157] The emission control module 1002 is used to control the emission of the detection beam of each emission unit in each emission cycle according to the emission code value set of each emission unit to obtain the original point cloud data;

[0158] The filtering module 1003 is used to perform a first filtering process and / or a second filtering process on the above-mentioned original point cloud data to obtain interference-free point cloud data.

[0159] Optionally, the laser radar anti-interference device 1000 further includes:

[0160] A determination module 1004 is used to determine whether there are parallel transmission units and / or serial transmission units among the plurality of transmission units when the laser radar has a plurality of transmission units;

[0161] The transmission control module 1002 is further configured to set a set of transmission coding values ​​of the parallel transmission unit and / or the serial transmission unit according to a preset rule.

[0162] Optionally, if there are parallel transmitting units in the transmitting units of the above-mentioned laser radar, the transmission code value sets of any two of the above-mentioned parallel transmitting units satisfy a preset cross-correlation condition; wherein the above-mentioned parallel transmitting units refer to: transmitting units that transmit approximately simultaneously in the same transmission cycle.

[0163] Optionally, if there is a serial transmitting unit in the transmitting unit of the above-mentioned laser radar, the difference in the transmitting code values ​​corresponding to the same transmission of adjacent serial transmitting units in the same transmitting cycle is a preset threshold; wherein the above-mentioned serial transmitting unit refers to: a transmitting unit that transmits sequentially in a time sequence in the same detection cycle

[0164] Alternatively, the code value determination module 1001 is used to determine the transmission code value set of each transmission unit of the laser radar, wherein there are parallel transmission units in the above-mentioned transmission units, and the transmission code value sets of any two of the above-mentioned parallel transmission units meet the preset cross-correlation condition, and the above-mentioned parallel transmission units refer to: transmission units that transmit approximately simultaneously in the same transmission cycle;

[0165] The emission control module 1002 is used to control the emission of the detection beam of each emission unit in each emission cycle according to the emission code value set of each emission unit to obtain the original point cloud data;

[0166] The filtering module 1003 is used to perform a first filtering process and / or a second filtering process on the above-mentioned original point cloud data to obtain interference-free point cloud data.

[0167] Alternatively, the coding value determination module 1001 is used to determine a set of transmission coding values ​​of each transmission unit of the laser radar, wherein there are serial transmission units in the above-mentioned transmission units, and the difference between the transmission coding values ​​corresponding to the same transmission of adjacent serial transmission units in the same transmission cycle is a preset threshold value, and the above-mentioned serial transmission unit refers to: a transmission unit that transmits sequentially in a time sequence in the same transmission cycle;

[0168] The emission control module 1002 is used to control the emission of the detection beam of each emission unit in each emission cycle according to the emission code value set of each emission unit to obtain the original point cloud data;

[0169] The filtering module 1003 is used to perform a first filtering process and / or a second filtering process on the above-mentioned original point cloud data to obtain interference-free point cloud data.

[0170] Optionally, the filtering module 1003 includes:

[0171] A first determining unit is configured to determine, for each test point in the original point cloud data, a test neighborhood centered on the test point based on a preset neighborhood size, wherein the neighborhood size is determined according to a size of the transmitted code value set;

[0172] A first calculation unit is used to calculate the difference between the distance measurement value of each point in the neighborhood to be measured except the point to be measured and the distance measurement value of the point to be measured;

[0173] The second determining unit is used to determine whether the test point is valid based on the difference.

[0174] Optionally, the second determining unit includes:

[0175] A counting subunit, used for counting the number of target distance differences among the distance differences, wherein the target distance differences are less than a preset distance difference threshold;

[0176] The first determination subunit is used to determine that the above-mentioned point to be measured is valid if the number of the above-mentioned target distance difference values ​​reaches a preset first number threshold.

[0177] Optionally, the filtering module 1003 includes:

[0178] An acquisition unit, configured to acquire, for each point to be measured in the original point cloud data, at least two points in a preset direction with the point to be measured as the center in the original point cloud data;

[0179] A fitting unit, used for fitting the at least two points and the point to be measured;

[0180] The third determining unit is used to determine whether the above-mentioned test point is valid based on the fitting result.

[0181] Optionally, the third determining unit includes:

[0182] The second determining subunit is configured to determine that the point to be measured is valid if the fitting result indicates that the at least two points and the point to be measured can be fitted into a straight line.

[0183] As can be seen from the above, in the embodiment of the present application, the anti-interference ability of the laser radar is improved from two aspects to improve the detection accuracy of the laser radar: the technical solution of the present application determines the emission code value set of each transmitting unit of the laser radar, wherein each emission code value set satisfies the preset autocorrelation condition; according to the emission code value set of each transmitting unit, the emission of the detection beam of each transmitting unit in each emission cycle is controlled to obtain the original point cloud data; the original point cloud data is subjected to the first filtering process and / or the second filtering process to obtain interference-free point cloud data. In this way, the corresponding emission code value set is determined for each transmitting unit, and the emission code value set satisfies the preset correlation condition. At the same time, the original point cloud data is filtered to remove the noise points in the original point cloud data, and finally the interference-free point cloud data is obtained. It can ensure that each transmitting unit can effectively reduce the echo signal crosstalk when transmitting in multiple different transmitting cycles, thereby improving the detection accuracy of the radar; further, by comprehensively considering various transmission strategies to set the transmission code of each transmitting unit, and filtering the echo data at the same time, it can ensure that no matter what transmission strategy the laser radar adopts to transmit the detection beam, the echo signal crosstalk level can be controlled at a low level, thereby further improving the accuracy of radar detection.

[0184] Corresponding to the laser radar anti-interference method provided above, the embodiment of the present application also provides an electronic device. Fig.11 The electronic device 11 in the embodiment of the present application includes: a memory 1101, one or more processors 1102 ( Fig.11 Only one is shown) and a computer program stored in the memory 1101 and executable on the processor. Among them: the memory 1101 is used to store software programs and units, and the processor 1102 executes various functional applications and diagnoses by running the software programs and units stored in the memory 1101 to obtain the resources corresponding to the above-mentioned preset events. Specifically, the processor 1102 is implemented by running the above-mentioned computer program stored in the memory 1101, and the solutions of the various method embodiments proposed above can be implemented, which will not be repeated here.

[0185] It should be understood that in the embodiment of the present application, the processor 1002 may be a central processing unit (CPU), and the processor may also be 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 the processor may also be any conventional processor, etc.

[0186] The memory 1101 may include a read-only memory and a random access memory, and provide instructions and data to the processor 1002. A part or all of the memory 1101 may also include a non-volatile random access memory. For example, the memory 1101 may also store information on the device category.

[0187] As can be seen from the above, in the embodiment of the present application, the anti-interference of the laser radar is improved from two aspects to improve the detection accuracy of the laser radar: on the one hand, from the perspective of laser emission, a corresponding emission code value set will be determined for each emission unit, and the emission code value set satisfies the preset correlation condition. Specifically, when each emission code value set satisfies the preset autocorrelation condition, for each emission unit, it can be ensured that the emission unit will not have echo signal crosstalk when transmitting in multiple different emission cycles, thereby reducing the interference suffered by the laser radar; when there are parallel emission units, that is, emission units that are emitted approximately at the same time in the same emission cycle, the emission code value sets of any two parallel emission units meet the preset cross-correlation conditions, which can ensure that these parallel emission units will not have echo signal crosstalk when transmitting in the same emission cycle, thereby reducing the interference suffered by the laser radar. On the other hand, from the perspective of data processing, when the original point cloud data is obtained, the original point cloud data can be filtered by one or two filtering processing methods according to the actual situation to remove the noise points in the original point cloud data, which can also reduce the interference suffered by the laser radar.

[0188] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the above-mentioned device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0189] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0190] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of external device software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0191] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the system embodiments described above are merely schematic. For example, the division of the above modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0192] The units described above as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0193] If the above-mentioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the associated hardware through a computer program. The above-mentioned computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the above-mentioned computer program includes computer program code, and the above-mentioned computer program code can be in source code form, object code form, executable file or some intermediate form, etc. The above-mentioned computer-readable storage medium may include: any entity or device capable of carrying the above-mentioned computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer-readable memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electrical carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content contained in the above-mentioned computer-readable storage medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable storage media does not include electrical carrier signals and telecommunication signals.

[0194] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A laser radar anti-interference method, characterized in that: The lidar includes a scanning device, and the laser emitted by the transmitting unit of the lidar scans the detection field of view through the scanning device. The lidar anti-interference method includes: Determine the number M of the emission coding values of any one transmitting unit of the lidar; Determine the number N of emissions completed by any one transmitting unit within a detection period T; If M < N, then for any one transmitting unit within the one detection period, the emission coding values within adjacent emission times are different; Control the transmitting unit to emit according to the emission coding value of any one transmitting unit to obtain the original point cloud data.

2. The laser radar anti-interference method according to claim 1, characterized in that: The lidar anti-interference method further includes: When there are multiple transmitting units in the lidar, determine whether there are parallel transmitting units and / or serial transmitting units among the multiple transmitting units; Set the set of emission coding values of the parallel transmitting units and / or serial transmitting units according to a preset rule.

3. The laser radar anti-interference method according to claim 2, characterized in that: The setting of the set of emission coding values of the parallel transmitting units and / or serial transmitting units according to the preset rule includes: If there are parallel transmitting units among the transmitting units of the lidar, ensure that the set of emission coding values between any two parallel transmitting units satisfies a preset cross-correlation condition; Wherein, the parallel transmitting units refer to the transmitting units that emit simultaneously within the same detection period.

4. The laser radar anti-interference method according to claim 2, characterized in that: The setting of the set of emission coding values of the parallel transmitting units and / or serial transmitting units according to the preset rule includes: If there are serial transmitting units among the transmitting units of the lidar, the difference between the emission coding values corresponding to the same emission within the same detection period of adjacent serial transmitting units is a preset threshold; Wherein, the serial transmitting units refer to the transmitting units that emit in sequence according to a preset time sequence within the same detection period.

5. The laser radar anti-interference method according to any one of claims 1 to 4, characterized in that: The lidar anti-interference method further includes performing a first filtering process on the original point cloud data to obtain interference-free point cloud data; The process of the first filtering process is: For each point to be measured in the original point cloud data, determine a measurement neighborhood centered on the point to be measured based on a preset neighborhood size; Calculate the difference between the ranging values of each point other than the point to be measured in the measurement neighborhood and the ranging value of the point to be measured; Determine whether the point to be measured is valid based on the difference.

6. The laser radar anti-interference method according to claim 5, characterized in that: The determining whether the point to be measured is valid based on the difference includes: Count the number of target differences in the differences, where the target difference is less than a preset difference threshold; If the number of target differences reaches a preset number threshold, determine that the point to be measured is valid.

7. The laser radar anti-interference method according to any one of claims 1 to 4, characterized in that: The lidar anti-interference method further includes performing a second filtering process on the original point cloud data to obtain interference-free point cloud data; The process of the second filtering process is: For each point to be measured in the original point cloud data, obtain at least two points in a preset direction centered on the point to be measured in the original point cloud data; Fit the at least two points and the point to be measured; Determine whether the point to be measured is valid based on the fitting result; Wherein, the determining whether the point to be measured is valid based on the fitting result includes: If the fitting result indicates that the at least two points and the point to be measured can be fitted into a straight line, it is determined that the point to be measured is valid.

8. A laser radar anti-interference device, characterized in that: include: A coding value determination module, used to determine a set of transmission coding values ​​of each transmission unit of the laser radar, wherein each set of transmission coding values ​​satisfies a preset autocorrelation condition; An emission control module, used to control the emission of the detection beam of each emission unit in each emission cycle according to the emission code value set of each emission unit, so as to obtain the original point cloud data; The filtering module is used to perform a first filtering process and / or a second filtering process on the original point cloud data to obtain interference-free point cloud data.

9. The laser radar anti-interference device according to claim 8, characterized in that: The laser radar anti-interference device also includes: A judgment module, used for judging whether there are parallel transmission units and / or serial transmission units among the plurality of transmission units when the laser radar has a plurality of transmission units; The transmission control module is also used to set the transmission code value set of the parallel transmission unit and / or the serial transmission unit according to a preset rule.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.

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