Timestamp storage method of laser radar and related product

Abstract

The invention provides a timestamp storage method of a laser radar and a related product. The method comprises the following steps: emitting laser beams for multiple times; the method comprises the following steps: sampling echoes of laser beams emitted for at least two times within a preset time interval through a first receiving unit to obtain sampling data of the first receiving unit corresponding to the laser beams emitted for at least two times, and according to the sampling data of the laser beam emitted for the (N-1) th time by the first receiving unit, determining the sampling data of the laser beam emitted for the (N-1) th time; obtaining first point cloud data and a corresponding first timestamp; acquiring second point cloud data and a corresponding second timestamp according to sampling data of the laser beam emitted for the Nth time by the first receiving unit; compressing the first point cloud data and the second point cloud data into third point cloud data; determining a corresponding third timestamp according to the third point cloud data; and storing the Nth sampling data and the (N-1) th sampling data of the first receiving unit according to the third point cloud data and the third timestamp. According to the invention, the consumption of storage resources can be reduced.

Description

Technical Field

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

[0002] Laser radar is an active remote sensing device that uses photoelectric technology for detection. It combines photoelectric detection technology with laser technology and is an advanced detection method that uses laser as the detection light source. Laser radar includes a transmitting module, a scanning module, a receiving module, a data processing module, etc. The transmitting module is used to transmit the detection signal to the target, the scanning module is used to change the transmission direction of the detection signal, the receiving module is used to sample the echo signal of the detection signal, and the data processing module is used to sample and process the echo signal, thereby obtaining the distance, reflectivity, speed, size and other information of the detection target.

[0003] The sampling data obtained by multiple detections by the receiving module in the laser radar is handed over to the data processing module for processing to obtain the point cloud data of multiple detections. Generally speaking, the amount of point cloud data is very large, and the receiving module often uses multiple adjacent receiving blocks to receive each detection signal, and the receiving blocks that receive the detection signals emitted at least twice adjacently overlap, resulting in some receiving blocks detecting at least twice in a row to obtain point cloud data. This will result in an even larger amount of point cloud data. In the prior art, in laser radars, all point cloud data obtained by multiple detections are usually output together to the microcontroller unit (MCU) for compression processing. The large amount of point cloud data will result in very high bandwidth consumption resources for point cloud data, so the point cloud data needs to be compressed.

[0004] In addition, since the target object may move during the laser radar scanning process, it is necessary to perform motion compensation on the point cloud data corresponding to the target object according to the detection time of the echo signal. Therefore, each detected point cloud data will have a timestamp. When compressing the point cloud data, how to compress the timestamp of each point cloud data also needs to be solved. Summary of the invention

[0005] The present application provides a timestamp storage method and related products for a laser radar, which can reduce the consumption of storage resources.

[0006] In a first aspect, the present application provides a timestamp storage method for a laser radar, comprising:

[0007] Fire laser beams multiple times;

[0008] The first receiving unit samples the echoes of the laser beams emitted at least twice within a preset time interval, and obtains the sampling data of the first receiving unit corresponding to the at least two laser beams emitted, wherein the first receiving unit is used to sample the laser beam emitted at the Nth time and the laser beam emitted at the N-1th time, where N is a positive integer greater than or equal to 2;

[0009] Acquire first point cloud data and a corresponding first timestamp according to the sampling data of the laser beam emitted for the N-1th time by the first receiving unit;

[0010] Acquire second point cloud data and a corresponding second timestamp according to the sampling data of the laser beam emitted for the Nth time by the first receiving unit;

[0011] compressing the first point cloud data and the second point cloud data into third point cloud data;

[0012] Determine a corresponding third timestamp according to the third point cloud data;

[0013] The Nth and N-1th sampling data of the receiving unit are stored according to the third point cloud data and the third timestamp.

[0014] Optionally, when N is a positive integer greater than 2, the method further includes:

[0015] The fourth point cloud data obtained by the first N-2 fusions are fused with the second point cloud data corresponding to the N-th transmission to obtain fifth point cloud data; wherein the fourth point cloud data corresponds to a fourth timestamp; and the fifth point cloud data is the target fused point cloud data of the first receiving unit;

[0016] Determine a fifth timestamp according to the fifth point cloud data; the fifth timestamp is the target fusion timestamp of the receiving unit;

[0017] The sampling data of the receiving unit is stored according to the target fusion point cloud data and the target fusion timestamp.

[0018] Optionally, determining a corresponding third timestamp according to the third point cloud data includes:

[0019] When the third point cloud data is one selected from the first point cloud data and the second point cloud data, the third timestamp is the timestamp corresponding to the selected point cloud data; and / or,

[0020] When the third point cloud data is obtained by weighted summation of the first point cloud data and the second point cloud data, the third timestamp is one of the first timestamp and the second timestamp selected according to a default rule, and the default rule is to select a timestamp with a later time from the two selection objects, or to select a timestamp with an earlier time from the two selection objects.

[0021] Optionally, compressing the first point cloud data and the second point cloud data into third point cloud data includes:

[0022] When the gap between the first point cloud data and the second point cloud data is less than a first preset threshold, the third point cloud data is obtained according to the weighted sum of the first point cloud data and the second point cloud data, or one of the first point cloud data and the second point cloud data is selected as the third point cloud data.

[0023] Optionally, compressing the first point cloud data and the second point cloud data into third point cloud data includes:

[0024] When the difference between the first point cloud data and the second point cloud data is not less than the first preset threshold, one of the first point cloud data and the second point cloud data is selected as the third point cloud data.

[0025] Optionally, the laser radar includes at least M rows of receiving units and / or K columns of receiving units, where M and K are positive integers greater than 0; wherein the Mth row and / or Kth column of receiving units includes at least two receiving units,

[0026] The first receiving unit is any one of the M rows of receiving units and / or the K columns of receiving units, and the preset time interval is a receiving time interval of a row or a column of receiving units.

[0027] Optionally, the method further comprises:

[0028] Acquire target fusion point cloud data and target fusion timestamp of each receiving unit except the first receiving unit in the M rows of receiving units and / or the K columns of receiving units;

[0029] The target fusion point cloud data of each receiving unit is obtained by fusion of sampling data obtained by sampling the echoes of the laser beams emitted at least twice within the preset time interval by the receiving unit, and the target fusion timestamp of each receiving unit is determined correspondingly according to the target fusion point cloud data;

[0030] Among them, the value of the target fusion timestamp stored in the i-th receiving unit in any row or column is the difference between the target fusion timestamp of the i-th receiving unit and the target fusion timestamp of the first receiving unit in the row or column, where i is a positive integer greater than 1.

[0031] In a second aspect, the present application provides a timestamp processing device, including:

[0032] A transmitting module, used for transmitting laser beams multiple times;

[0033] The sampling module includes a first receiving unit, wherein the first receiving unit is used to sample the echoes of the laser beams emitted at least twice within a preset time interval, and obtain the sampling data of the first receiving unit corresponding to the at least two laser beams emitted, wherein the first receiving unit is used to sample the laser beam emitted at the Nth time and the laser beam emitted at the N-1th time, and N is a positive integer greater than or equal to 2;

[0034] A first acquisition module, configured to acquire first point cloud data and a corresponding first timestamp according to sampling data of the laser beam emitted for the N-1th time by the first receiving unit;

[0035] A second acquisition module, configured to acquire second point cloud data and a corresponding second timestamp according to the sampling data of the laser beam emitted for the Nth time by the first receiving unit;

[0036] A compression module, used for compressing the first point cloud data and the second point cloud data into third point cloud data;

[0037] A determination module, configured to determine a corresponding third timestamp according to the third point cloud data;

[0038] A storage module is used to store the Nth and N-1th sampling data of the receiving unit according to the third point cloud data and the third timestamp.

[0039] In a third aspect, the present application provides a laser radar, comprising:

[0040] Processor; and

[0041] A memory having executable codes stored thereon, which, when executed by the processor, causes the processor to execute any one of the methods described above.

[0042] In a fourth aspect, the present application provides a computer-readable storage medium storing executable code, which, when executed by a processor of a laser radar, enables the laser radar to execute any one of the methods described.

[0043] In the embodiment of the present application, since at least the first receiving unit is used in at least two adjacent detections, the point cloud data of the laser beams emitted twice by the first receiving unit are compressed into third point cloud data. Since the point cloud data of all laser beams emitted by the same receiving unit within a certain detection time interval most likely correspond to the same object, compressing these two point cloud data can reduce the amount of point cloud data and thus reduce the consumption of bandwidth resources by the point cloud data while maintaining a small amount of information loss. In addition, the timestamps corresponding to the two point cloud data are fused into one timestamp, which can further reduce the amount of point cloud data. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 is a schematic diagram of an embodiment of a laser radar data processing method of the present application;

[0045] Figure 2 is a schematic diagram of a transmitting array and a receiving array of the laser radar of the present application;

[0046] Figure 3a This is a schematic diagram of the corresponding relationship between the transmission and reception of the laser radar of the present application;

[0047] Figure 3b It is another schematic diagram of the corresponding relationship between the transmission and reception of the laser radar of the present application;

[0048] Figure 4 is a schematic diagram of a receiving array of the laser radar of the present application;

[0049] Figure 5 It is a schematic diagram of the working timing relationship between the transmitting module and the sampling module of the laser radar of the present application;

[0050] Figure 6 is a schematic diagram of an embodiment of a timestamp processing device in an embodiment of the present application;

[0051] Figure 7 It is a schematic diagram of an embodiment of a laser radar in an embodiment of the present application. DETAILED DESCRIPTION

[0052] The embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0053] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0054] It should be understood that although the terms "first", "second", "third", etc. may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0055] Lidar is a radar system that emits laser beams to detect the position, speed and other characteristic quantities of a target. Its working principle is to use a laser transmitter to emit multiple laser beams in sequence. If the laser beam encounters an object, it will be reflected, and a receiver will receive the reflected echo. Lidar can be a mechanical Lidar, a semi-solid Lidar or a pure solid-state Lidar. Lidar calculates the time difference between the time of receiving the reflected echo and the time of emitting the laser beam, and the time difference is the flight time of the laser beam. Lidar calculates the distance, direction and other parameters of the object that reflects the echo based on the flight time, and calculates the reflectivity based on the energy of the echo and the energy of the emitted laser beam, thereby detecting the external environment.

[0056] Combine the following Figure 1 The timestamp storage method of the laser radar of the present application is introduced with examples.

[0057] like Figure 1 As shown, the timestamp storage method 100 of the laser radar of the present application includes:

[0058] Step S101 : sampling echoes of laser beams emitted at least twice within a preset time interval by a first receiving unit to obtain sampling data of the first receiving unit corresponding to the at least two emitted laser beams.

[0059] It can be understood that the laser radar includes at least one laser transmitting module and at least one laser receiving module. As an optional embodiment, each laser transmitting module includes at least two transmitting units, and the receiving module includes at least two receiving units.

[0060] Among them, Figure 2 As shown, as an optional implementation, the laser emission module can be a laser emission array, such as Figure 2 (a); The laser receiving module may be a laser receiving array, such as Figure 2 (b).

[0061] The correspondence between the transmission and reception may be, for example, a one-to-one relationship, that is, one transmission corresponds to one reception. As another optional implementation, Figure 3a As shown, the correspondence between transmission and reception may also be a 1-to-3 relationship, that is, one transmission corresponds to three receptions.

[0062] It can be understood that, as an optional implementation, the transmitting module can be scanned by row, that is, after the transmitting units in the first row have completed transmitting in sequence, the transmitting units in the second row start to transmit in sequence.

[0063] As another optional implementation, the transmitting module may also scan multiple rows simultaneously to control the corresponding receiving blocks to receive, such as Figure 3b As shown, the Ath row A0 and the Eth row E0 can complete the transmission at the same time, and are received by the corresponding receiving units A0, A1, A2 corresponding to A0, and are received by the receiving units E0, E1, E2 corresponding to E0 at the same time.

[0064] As an optional implementation, each transmitting unit may transmit once in each scanning cycle, or each transmitting unit may transmit at least twice in each scanning cycle.

[0065] It can be understood that the emission angles of the laser beams corresponding to the two adjacent laser emission can be the same or different. When the emission angles of the laser beams corresponding to the two adjacent laser emission are the same, the two adjacent laser emission can be emitted by the same laser emission unit, and when the emission angles of the two adjacent laser emission are different, the two adjacent laser emission can be emitted by different laser emission units; as an optional method, a scanning module can also be provided in the laser radar, and the emission direction of the laser beam emitted by the same laser emission module can be changed by the scanning module, so that the laser beam scans in different directions in turn.

[0066] Optionally, the laser radar emits laser beams at different azimuth angles (i.e., through different transmitting units) along a row, wherein the emission pitch angles of the laser beams emitted along a row have a maximum emission pitch angle and a minimum emission pitch angle that differ by less than a preset angle. In some examples, after the laser radar emits laser beams at different azimuth angles along a row, it continues to emit laser beams at different azimuth angles along another row, and scans back and forth along multiple rows in sequence. In a frame of point cloud obtained after scanning in this way, each point cloud point is arranged in multiple rows and columns.

[0067] The laser radar is also provided with a receiving module, through which the echo of each emitted laser beam is sampled. The receiving module includes multiple receiving units. After each emission of a laser beam, the receiving unit corresponding to the emission enters a sampling working state to sample the echo of the emitted laser beam and obtain sampling data. Figure 4 As shown, each receiving module includes a plurality of receiving units, each receiving unit includes at least one receiving pixel array, and the receiving pixel array includes a plurality of receiving pixels. All receiving pixel arrays in each receiving block enter the sampling working state in whole or in part when the receiving block enters the sampling working state. The sampling data of each receiving block includes the sampling data of each pixel in the receiving pixel array.

[0068] The receiving module includes at least one first receiving unit, and each receiving unit in the receiving block corresponds to at least two of the multiple transmissions. It can be understood that, as an optional method, at least one receiving block corresponds to at least two adjacent transmissions. For example, the first receiving unit is used to sample the laser beam emitted for the Nth time and the laser beam emitted for the N-1th time, where N is a positive integer greater than or equal to 2. For another example, the first receiving unit is also used to sample the laser beam emitted for the N+1th time.

[0069] Optionally, each transmission corresponds to at least two receiving blocks, for example, the laser beam corresponding to the Nth transmission has at least the first receiving block and the second receiving block. Optionally, among the receiving blocks corresponding to two adjacent transmissions, some receiving blocks are the same. For example, when N is greater than 1, among the at least two receiving blocks corresponding to the Nth transmission, the second receiving block is used to sample the laser beam of the Nth transmission but not to sample the laser beam of the N-1th transmission. Optionally, the second receiving block is also used to sample the laser beam of the N+1th transmission.

[0070] Step S103: Acquire first point cloud data and a corresponding first timestamp according to the sampling data of the laser beam emitted for the N-1th time by the first receiving unit.

[0071] Step S104: acquiring second point cloud data and a corresponding second timestamp according to the sampling data of the laser beam emitted for the Nth time by the first receiving unit.

[0072] After acquiring the sampling data corresponding to each emission, the point cloud data corresponding to the emission can be acquired according to the sampling data. The point cloud data includes at least one of the distance, orientation, reflectivity, and spot area, and is used to characterize the target object that reflects the laser beam of the emission to form an echo. Since the target object may move during the scanning process of the laser radar, the timestamp corresponding to each point cloud data is also acquired for subsequent motion compensation of the point cloud data.

[0073] Step S105: compress the first point cloud data and the second point cloud data into third point cloud data.

[0074] The receiving unit generates a point cloud data and a corresponding timestamp for each echo of the laser beam emitted (if any). However, the point cloud data of all the laser beams emitted by the same receiving unit within a certain detection time interval are likely to correspond to the same target object, so there is redundancy in the data. In this embodiment, the first point cloud data and the second point cloud data are compressed into the third point cloud data to reduce data redundancy.

[0075] There are multiple ways of compression, for example, when the weighted sum of the first point cloud data and the second point cloud data results in the third point cloud data, or one of the first point cloud data and the second point cloud data is selected as the third point cloud data. For another example, when the difference between the first point cloud data and the second point cloud data is not less than a second preset threshold, one of the first point cloud data and the second point cloud data is selected as the third point cloud data. In determining whether the difference between the first point cloud data and the second point cloud data is less than the first preset threshold, for example, it can be determined by determining the difference between the distances in the two point cloud data.

[0076] Step S106: determining a corresponding third timestamp according to the third point cloud data.

[0077] After the first point cloud data and the second point cloud data are compressed into the third point cloud data, the timestamp corresponding to the third point cloud data can be determined from the first timestamp and the second timestamp according to the compression rule. Optionally, when the third point cloud data is one selected from the first point cloud data and the second point cloud data, the third timestamp is the timestamp corresponding to the selected point cloud data. For example, when the first point cloud data is selected as the third point cloud data, the first timestamp is used as the third timestamp corresponding to the third point cloud data.

[0078] Optionally, when the third point cloud data is obtained by weighted summing the first point cloud data and the second point cloud data, the third timestamp is selected from the first timestamp and the second timestamp according to a default rule, and the default rule is to select a later timestamp from the two selection objects, or to select an earlier timestamp from the two selection objects. For example, when the third point cloud data is obtained by weighted summing the first point cloud data and the second point cloud data, the latest timestamp (i.e., the second timestamp) is used as the third timestamp by default.

[0079] Step S107 , storing the Nth and N-1th sampling data of the receiving unit according to the third point cloud data and the third timestamp.

[0080] After the compressed third point cloud data and the third timestamp are obtained, the first point cloud data and the corresponding timestamp are not stored, and the second point cloud data and the corresponding timestamp are not stored. Instead, the compressed third point cloud data and the third timestamp are stored.

[0081] In the embodiment of the present application, since at least the first receiving unit is used in at least two adjacent detections, by compressing the point cloud data of the laser beams emitted by the first receiving unit respectively corresponding to the two times into the third point cloud data, since the point cloud data of all the laser beams emitted by the same receiving unit within a certain detection time interval are likely to correspond to the same object, compressing these two point cloud data can reduce the amount of point cloud data and then reduce the consumption of bandwidth resources by point cloud data while maintaining a small amount of information loss; in addition, the timestamps corresponding to the two point cloud data are merged into one timestamp, which can further reduce the amount of point cloud data. In the prior art, the bit width of a general high-precision timestamp value is 80 bits, that is, an 80-bit timestamp value is stored for each receiving unit. This storage method requires a lot of storage space and will result in a waste of chip resources. Through the embodiment of the present application, the storage space can be reduced and the waste of chip resources can be reduced.

[0082] In this way, after compressing the point cloud data and the corresponding timestamp of the laser beam emitted at least twice by the same receiving unit, the point cloud data of the laser beam emitted at least twice by the receiving unit within a preset time interval can be compressed into target fused point cloud data, and the timestamp of the point cloud data of the laser beam emitted at least twice within the preset time interval can be compressed into a target fused timestamp corresponding to the preset time interval, and the target fused point cloud data and the target fusion timestamp can be stored.

[0083] In the example where the first receiving unit is used to sample the laser beam emitted only twice (i.e., the Nth and N-1th times) in the preset time interval, the third timestamp is the target fusion timestamp of the first receiving unit in the preset time interval. In the example where the first receiving unit is used to sample the laser beam emitted at least three times in the preset time interval, for example, when N is a positive integer greater than 2, optionally, the fourth point cloud data obtained by the first N-2 fusions is also fused with the second point cloud data corresponding to the Nth emission to obtain the fifth point cloud data. The fourth point cloud data corresponds to the fourth timestamp. The first N-2 fusions are respectively the fusion of the point cloud data emitted by any two adjacent times in the first N-2 times to obtain the fusion results of the first N-2 times. The fifth point cloud data is the target fusion point cloud data of the receiving unit. After obtaining the fifth point cloud data, the fifth timestamp is also determined according to the fifth point cloud data, and the fifth timestamp is the target fusion timestamp of the first receiving unit. Then the sampling data of the receiving unit is stored according to the target fusion point cloud data and the target fusion timestamp.

[0084] There may be multiple preset time intervals. For example, in the example where the laser beams are emitted multiple times in step S101 and are emitted sequentially at different azimuth angles along a row, the preset time interval is at least part of the emission time interval corresponding to the laser beams emitted in the row. For example, the preset time interval is the emission time interval for scanning a row, or a part of the emission time interval for scanning a row, for example, each time a laser beam is emitted a preset number of times in scanning a row is a preset time interval, which is not limited here.

[0085] In the example where the preset time interval is at least a part of the emission time interval corresponding to the laser beam emitted in the row, the at least two receiving units are located in a row of receiving units. Referring to the above description of compressing the point cloud data and timestamps of each emission of the first receiving unit corresponding to the preset time interval into target fused point cloud data and corresponding target fusion timestamps, the compressed target fusion point cloud data and corresponding target fusion timestamps corresponding to the preset time interval can be obtained for each receiving unit in the row of receiving units.

[0086] In some examples, the laser radar includes at least M rows of receiving units and / or K columns of receiving units, M and K are positive integers greater than 0; wherein the Mth row and / or the Kth column of receiving units includes at least two receiving units, the first receiving unit is any one of the M rows of receiving units and / or the K columns of receiving units, and the preset time interval is the receiving time interval of a row or a column of receiving units.

[0087] Optionally, the target fusion point cloud data and target fusion timestamp of each receiving unit except the first receiving unit in the M rows of receiving units and / or the K columns of receiving units are also obtained. The target fusion point cloud data of each receiving unit is obtained by fusion of sampling data obtained by sampling the echo of the laser beam emitted at least twice within the preset time interval by the receiving unit, and the target fusion timestamp of each receiving unit is determined correspondingly according to the target fusion point cloud data.

[0088] Specifically, for each of the transmissions in the row of transmissions except the transmission in step S102, the echo of the laser beam of the transmission is sampled by at least two receiving units in the row of receiving units, and finally the sampling data of the laser beam of the row of transmissions is obtained, wherein each receiving unit is used to sample the echo of the laser beam of at least two transmissions in the preset time interval, and the sampling data of the laser beam of at least two transmissions corresponding to each receiving unit are obtained. According to the sampling data of the laser beam of at least two transmissions corresponding to each receiving unit, the point cloud data of the laser beam of at least two transmissions corresponding to each receiving unit is obtained. According to the point cloud data of the remaining receiving units in the row of receiving units except the first receiving unit in the preset time interval, the target fusion point cloud data and the target fusion timestamp of each receiving unit in the remaining receiving units corresponding to the preset time interval are compressed.

[0089] Optionally, when a row of receiving units has been obtained with compressed point cloud data corresponding to a preset time interval, it is also determined whether there is any compressed point cloud data of one receiving unit in the row of receiving units that is the point cloud data of the last sampling of the receiving unit in the row of transmission. If so, the target fusion timestamp of each receiving unit in the row of receiving units is replaced with the timestamp of the last sampling of the receiving unit in the row of transmission. In this way, as long as there is a point cloud data in the row of receiving units that is obtained based on the latest echo within the preset time interval, the timestamps of the row of receiving units are all the latest timestamps within the preset time interval.

[0090] Optionally, the target fusion timestamp corresponding to the preset time interval of each receiving unit of the M rows of receiving units and / or the K columns of receiving units is also stored. Optionally, the value of the target fusion timestamp stored by the ith receiving unit in any row or column is the difference between the target fusion timestamp of the ith receiving unit and the target fusion timestamp of the first receiving unit in the row or column, where i is a positive integer greater than 1. Since the time interval between pixels is very small within the scanning time of a row, the high bits of the timestamp values ​​stored in different pixels are the same within the scanning time of a row. By storing the difference between the target fusion timestamps of the remaining receiving units in a row of receiving units and the target fusion timestamp of the first receiving unit, the storage space occupied by the target fusion timestamps of the remaining receiving units can be reduced.

[0091] For example, the bit width of a general storage area is 32 bits. Three address spaces are required to store the complete value of the target fusion timestamp of the first receiving unit in a row, while the difference between the target fusion timestamp of the remaining receiving units in a row and the target fusion timestamp of the first receiving unit generally only requires 32 bits, that is, one address space. Compared with the prior art that uses 80 bits to store the timestamp of each receiving unit, the occupied storage space can be greatly reduced.

[0092] Combine the following Figure 5 A specific example of the timestamp storage method of the lidar of the present application is explained.

[0093] like Figure 5 As shown, Figure 5 1 is a schematic diagram of the working sequence relationship of the transmitting module and the sampling module of the laser radar of the present application. The transmitting module of the laser radar includes a first transmitting unit and a second transmitting unit. In each transmission, the first transmitting unit and the second transmitting unit are used to simultaneously transmit a laser beam. The sampling module 21 includes a receiving block array, which includes a plurality of rows of receiving blocks ( Figure 5 Only one row of receiving blocks 22 is shown in the figure, each receiving block includes a receiving unit array (not shown), and each row includes two receiving blocks located in the left and right areas 31 and 32 of the receiving block array respectively. The emitted laser beam is used to scan along different rows in sequence, wherein the receiving blocks in different rows correspond one-to-one to the scanning of the different rows respectively, and each row of receiving blocks is used to sample the echo of the laser beam emitted when the corresponding row is scanned. Among them, for each emission in each row of scanning, there are at least two receiving blocks for sampling corresponding to each laser beam in the emission. Figure 2 FIG. 4 illustrates the working state changes of the first row of receiving blocks in the receiving block array in different transmissions in the first row scan of the transmitting module.

[0094] Specifically, Figure 5As described above, in the first emission of the first row scan of the corresponding emission module, the echo of the laser beam EL1 emitted by the first emission unit is sampled by the 1st to 3rd receiving blocks RL1 on the left side of the first row, and the echo of the laser beam ER1 emitted by the second emission unit is sampled by the last two receiving blocks in the first row in area 31 and the first receiving block in area 32, a total of three receiving blocks RR1. Each receiving block in the receiving block RL1 is used to obtain the corresponding point cloud data and timestamp according to the echo sampling data of the laser beam EL1. Each receiving block in the receiving block RR1 is used to obtain the corresponding point cloud data and timestamp according to the echo sampling data of the laser beam ER1.

[0095] In the second transmission of the first row scan of the corresponding transmitting module, the echo of the laser beam EL2 emitted by the first transmitting unit is sampled by the 2nd to 4th receiving modules RL2 on the left side of the first row, and the echo of the laser beam ER2 emitted by the second transmitting unit is sampled by the last receiving block in the first row in area 31 and the first two receiving blocks in area 32, a total of three receiving modules RR2. Each receiving block in the receiving block RL2 is used to obtain the corresponding point cloud data and timestamp according to the echo sampling data of the laser beam EL2. Each receiving block in the receiving block RR2 is used to obtain the corresponding point cloud data and timestamp according to the echo sampling data of the laser beam ER2.

[0096] Since the two receiving blocks simultaneously located in RL1 and RL2, and the two receiving blocks simultaneously located in RR1 and RR2 are used for sampling the laser beams emitted for the first time and the second time, the point cloud data and timestamps corresponding to the laser beams emitted for the first time and the second time in each of the four receiving blocks are compressed into one point cloud data and timestamp. Taking the first receiving unit in the receiving block 221 located in RL1 as an example, the first point cloud data corresponding to the laser beam EL1 and the second point cloud data corresponding to the laser beam EL2 of the first receiving unit are compressed into the third point cloud data, and the first timestamp corresponding to the first point cloud data and the second timestamp corresponding to the second point cloud data are compressed into the third timestamp corresponding to the third point cloud data.

[0097] In the third emission of the first row scan of the corresponding emission module, the echo of the laser beam EL3 emitted by the first emission unit is sampled by the 3rd to 5th receiving modules RL3 on the left side of the first row, and the echo of the laser beam ER3 emitted by the second emission unit is sampled by the 1st to 3rd receiving blocks in area 32, a total of three receiving modules RR3. Each receiving block in the receiving block RL3 is used to obtain the corresponding point cloud data and timestamp based on the echo sampling data of the laser beam EL3. Each receiving block in the receiving block RR3 is used to obtain the corresponding point cloud data and timestamp based on the echo sampling data of the laser beam ER3. Taking the first receiving unit as an example, the fourth point cloud data and the third point cloud data corresponding to the laser beam EL3 of the first receiving unit are compressed into the fifth point cloud data, and the third timestamp corresponding to the third point cloud data and the fourth timestamp corresponding to the fourth point cloud data are compressed into the fifth timestamp corresponding to the fifth point cloud data.

[0098] Taking the time interval in which the preset time interval is a line scan as an example, since the first receiving unit is only used to sample the echoes of the laser beams emitted three times in the preset time interval, the compressed fifth point cloud data is used as the target fusion point cloud data of the first receiving unit corresponding to the preset time interval, and the fifth timestamp is used as the target fusion timestamp of the first receiving unit corresponding to the preset time interval.

[0099] Optionally, the third receiving block 222 in the receiving block RR1 is used to sample the echo of the laser beam ER1 in the first emission and the echo of the laser beam ELi-1 and the laser beam ELi-2 in the i-1th (also the second to last) and i-2th (also the third to last) times in the first line scan, respectively. Therefore, when compressing the point cloud data and timestamp, the point cloud data and timestamp corresponding to the laser beam ER1 of the first receiving block 232 are also compressed together with the point cloud data and timestamp corresponding to the laser beam ELi-1 and the laser beam ELi-2. Similarly, the point cloud data and timestamp of the laser beam corresponding to all emissions (including two non-adjacent emissions) of the second receiving block in the receiving block RR1 within the preset time interval are compressed.

[0100] In this way, after scanning a row, a target fusion point cloud data and a target fusion timestamp corresponding to the row scan can be obtained for each receiving unit in each receiving block of the row. Optionally, when storing the target fusion timestamp of each receiving unit in each receiving block of the row, the complete value of the target fusion timestamp of the first receiving unit in the first receiving block of the row is stored, and the difference between the target fusion timestamp of the remaining receiving units and the target fusion timestamp of the first receiving unit is stored.

[0101] The present application also provides a timestamp processing device. Figure 6 As shown, Figure 63 is a schematic diagram of an embodiment of a timestamp processing device in an embodiment of the present application. The timestamp processing device 300 includes:

[0102] The transmitting module 301 is used to transmit the laser beam multiple times;

[0103] The sampling module 302 includes a first receiving unit, the first receiving unit being used to sample the echoes of the laser beams emitted at least twice within a preset time interval, and obtain the sampling data of the first receiving unit corresponding to the at least two laser beams emitted, wherein the first receiving unit is used to sample the laser beam emitted at the Nth time and the laser beam emitted at the N-1th time, where N is a positive integer greater than or equal to 2;

[0104] A first acquisition module 303, configured to acquire first point cloud data and a corresponding first timestamp according to the sampling data of the laser beam emitted for the N-1th time by the first receiving unit;

[0105] A second acquisition module 304 is used to acquire second point cloud data and a corresponding second timestamp according to the sampling data of the laser beam emitted for the Nth time by the first receiving unit;

[0106] A compression module 305, configured to compress the first point cloud data and the second point cloud data into third point cloud data;

[0107] A determination module 306, configured to determine a corresponding third timestamp according to the third point cloud data;

[0108] The storage module 307 is used to store the Nth and N-1th sampling data of the receiving unit according to the third point cloud data and the third timestamp.

[0109] Optionally, when N is a positive integer greater than 2, the compression module 305 is further used to fuse the fourth point cloud data obtained by the first N-2 fusions with the second point cloud data corresponding to the N-th transmission to obtain fifth point cloud data; wherein the fourth point cloud data corresponds to a fourth timestamp; and the fifth point cloud data is the target fused point cloud data of the first receiving unit;

[0110] The determination module 306 is further configured to determine a fifth timestamp according to the fifth point cloud data; the fifth timestamp is a target fusion timestamp of the receiving unit;

[0111] The storage module 307 is further configured to store the sampling data of the receiving unit according to the target fusion point cloud data and the target fusion timestamp.

[0112] Optionally, the determining module 306 determines the corresponding third timestamp according to the third point cloud data, specifically for:

[0113] When the third point cloud data is one selected from the first point cloud data and the second point cloud data, the third timestamp is the timestamp corresponding to the selected point cloud data; and / or,

[0114] When the third point cloud data is obtained by weighted summation of the first point cloud data and the second point cloud data, the third timestamp is one of the first timestamp and the second timestamp selected according to a default rule, and the default rule is to select a timestamp with a later time from the two selection objects, or to select a timestamp with an earlier time from the two selection objects.

[0115] Optionally, when compressing the first point cloud data and the second point cloud data into third point cloud data, the compression module 305 is specifically used to:

[0116] When the gap between the first point cloud data and the second point cloud data is less than a first preset threshold, the third point cloud data is obtained according to the weighted sum of the first point cloud data and the second point cloud data, or one of the first point cloud data and the second point cloud data is selected as the third point cloud data.

[0117] Optionally, when compressing the first point cloud data and the second point cloud data into third point cloud data, the compression module 305 is specifically used to:

[0118] When the difference between the first point cloud data and the second point cloud data is not less than the first preset threshold, one of the first point cloud data and the second point cloud data is selected as the third point cloud data.

[0119] Optionally, the laser radar includes at least M rows of receiving units and / or K columns of receiving units, where M and K are positive integers greater than 0; wherein the Mth row and / or Kth column of receiving units includes at least two receiving units,

[0120] The first receiving unit is any one of the M rows of receiving units and / or the K columns of receiving units, and the preset time interval is a receiving time interval of a row or a column of receiving units.

[0121] Optionally, the device 300 further includes:

[0122] A third acquisition module is used to acquire target fusion point cloud data and target fusion timestamp of each receiving unit except the first receiving unit in the M rows of receiving units and / or the K columns of receiving units;

[0123] The target fusion point cloud data of each receiving unit is obtained by fusion of sampling data obtained by sampling the echoes of the laser beams emitted at least twice within the preset time interval by the receiving unit, and the target fusion timestamp of each receiving unit is determined correspondingly according to the target fusion point cloud data;

[0124] Among them, the value of the target fusion timestamp stored in the i-th receiving unit in any row or column is the difference between the target fusion timestamp of the i-th receiving unit and the target fusion timestamp of the first receiving unit in the row or column, where i is a positive integer greater than 1.

[0125] The present application also provides a laser radar, such as Figure 7 As shown, Figure 7 4 is a schematic diagram of an embodiment of a laser radar in an embodiment of the present application. The laser radar 40 includes a memory 41 and a processor 42 .

[0126] The processor 42 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0127] The memory 41 may include various types of storage units, such as system memory, read-only memory (ROM) and permanent storage devices. Among them, ROM can store static data or instructions required by the processor 42 or other modules of the computer. The permanent storage device may be a readable and writable storage device. The permanent storage device may be a non-volatile storage device that does not lose the stored instructions and data even after the computer is powered off. In some embodiments, the permanent storage device uses a large-capacity storage device (such as a magnetic or optical disk, flash memory) as a permanent storage device. In some other embodiments, the permanent storage device may be a removable storage device (such as a floppy disk, an optical drive). The system memory may be a readable and writable storage device or a volatile readable and writable storage device, such as a dynamic random access memory. The system memory may store some or all instructions and data required by the processor at run time. In addition, the memory 81 may include any combination of computer-readable storage media, including various types of semiconductor memory chips (such as DRAM, SRAM, SDRAM, flash memory, programmable read-only memory), and disks and / or optical disks may also be used. In some embodiments, the memory 40 may include a readable and / or writable removable storage device, such as a laser disc (CD), a read-only digital versatile disc (such as a DVD-ROM, a double-layer DVD-ROM), a read-only Blu-ray disc, an ultra-density optical disc, a flash memory card (such as an SD card, a mini SD card, a Micro-SD card, etc.), a magnetic floppy disk, etc. The computer-readable storage medium does not contain carrier waves and transient electronic signals transmitted wirelessly or wired.

[0128] The memory 41 stores executable codes, and when the executable codes are processed by the processor 42 , the processor 42 can execute part or all of the methods described above.

[0129] Alternatively, the present application can also be implemented as a computer-readable storage medium (or non-transitory machine-readable storage medium or machine-readable storage medium) on which executable code (or computer program or computer instruction code) is stored. When the executable code (or computer program or computer instruction code) is executed by a processor of an electronic device (or server, etc.), the processor executes part or all of the steps of the above-mentioned method according to the present application.

[0130] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A timestamp storage method for a laser radar, characterized in that: include: The first receiving unit samples the echoes of the laser beams emitted at least twice within a preset time interval, and obtains the sampling data of the first receiving unit corresponding to the at least two laser beams emitted, wherein the first receiving unit is used to sample the laser beam emitted at the Nth time and the laser beam emitted at the N-1th time, where N is a positive integer greater than or equal to 2; Acquire first point cloud data and a corresponding first timestamp according to the sampling data of the laser beam emitted for the N-1th time by the first receiving unit; Acquire second point cloud data and a corresponding second timestamp according to the sampling data of the laser beam emitted for the Nth time by the first receiving unit; compressing the first point cloud data and the second point cloud data into third point cloud data; Determine a corresponding third timestamp according to the third point cloud data; The Nth and N-1th sampling data of the first receiving unit are stored according to the third point cloud data and the third timestamp.

2. The method according to claim 1, characterized in that: When N is a positive integer greater than 2, the method further includes: The fourth point cloud data obtained by the first N-2 fusions are fused with the second point cloud data corresponding to the N-th transmission to obtain fifth point cloud data; wherein the fourth point cloud data corresponds to a fourth timestamp; and the fifth point cloud data is the target fused point cloud data of the first receiving unit; Determine a fifth timestamp according to the fifth point cloud data; the fifth timestamp is the target fusion timestamp of the receiving unit; The sampling data of the receiving unit is stored according to the target fusion point cloud data and the target fusion timestamp.

3. The method according to claim 1, characterized in that The determining a corresponding third timestamp according to the third point cloud data comprises: When the third point cloud data is one selected from the first point cloud data and the second point cloud data, the third timestamp is the timestamp corresponding to the selected point cloud data; and / or, When the third point cloud data is obtained by weighted summation of the first point cloud data and the second point cloud data, the third timestamp is one of the first timestamp and the second timestamp selected according to a default rule, and the default rule is to select a timestamp with a later time from the two selection objects, or to select a timestamp with an earlier time from the two selection objects.

4. The method according to claim 3, characterized in that The compressing the first point cloud data and the second point cloud data into third point cloud data comprises: When the gap between the first point cloud data and the second data is less than a first preset threshold, the third point cloud data is obtained according to the weighted sum of the first point cloud data and the second point cloud data, or one of the first point cloud data and the second point cloud data is selected as the third point cloud data.

5. The method according to claim 3, characterized in that: The compressing the first point cloud data and the second point cloud data into third point cloud data comprises: When the difference between the first point cloud data and the second point cloud data is not less than the first preset threshold, one of the first point cloud data and the second point cloud data is selected as the third point cloud data.

6. The method according to any one of claims 1 to 5, characterized in that: The laser radar comprises at least M rows of receiving units and / or K columns of receiving units, where M and K are positive integers greater than 0; The receiving units in the Mth row and / or the Kth column include at least two receiving units. The first receiving unit is any one of the M rows of receiving units and / or the K columns of receiving units, and the preset time interval is a receiving time interval of a row or a column of receiving units.

7. The method according to claim 6, characterized in that The method further comprises: Acquire target fusion point cloud data and target fusion timestamp of each receiving unit except the first receiving unit in the M rows of receiving units and / or the K columns of receiving units; The target fusion point cloud data of each receiving unit is obtained by fusion of sampling data obtained by sampling the echoes of the laser beams emitted at least twice within the preset time interval by the receiving unit, and the target fusion timestamp of each receiving unit is determined correspondingly according to the target fusion point cloud data; Among them, the value of the target fusion timestamp stored in the i-th receiving unit in any row or column is the difference between the target fusion timestamp of the i-th receiving unit and the target fusion timestamp of the first receiving unit in the row or column, where i is a positive integer greater than 1.

8. A timestamp processing device, characterized in that: include: A transmitting module, used for transmitting laser beams multiple times; The sampling module includes a first receiving unit, wherein the first receiving unit is used to sample the echoes of the laser beams emitted at least twice within a preset time interval, and obtain the sampling data of the first receiving unit corresponding to the at least two laser beams emitted, wherein the first receiving unit is used to sample the laser beam emitted at the Nth time and the laser beam emitted at the N-1th time, and N is a positive integer greater than or equal to 2; A first acquisition module, configured to acquire first point cloud data and a corresponding first timestamp according to sampling data of the laser beam emitted for the N-1th time by the first receiving unit; A second acquisition module, configured to acquire second point cloud data and a corresponding second timestamp according to the sampling data of the laser beam emitted for the Nth time by the first receiving unit; A compression module, used for compressing the first point cloud data and the second point cloud data into third point cloud data; A determination module, configured to determine a corresponding third timestamp according to the third point cloud data; A storage module is used to store the Nth and N-1th sampling data of the receiving unit according to the third point cloud data and the third timestamp.

9. A laser radar, characterized in that: include: processor; as well as A memory having executable codes stored thereon, which, when executed by the processor, causes the processor to execute the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: An executable code is stored, and when the executable code is executed by a processor of a laser radar, the laser radar executes the method as described in any one of claims 1 to 7.

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