Lidar return signal processing method and apparatus
By receiving and buffering echo signals from multi-dimensional signal transmission angles, extracting target signals from a preset neighborhood window and performing non-coherent accumulation, the problem of insufficient signal-to-noise ratio in traditional methods is solved, thereby improving the ranging capability of lidar echo signals.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SUTENG INNOVATION TECHNOLOGY CO LTD
- Filing Date
- 2019-09-25
- Publication Date
- 2026-07-21
AI Technical Summary
Traditional methods cannot effectively improve the signal-to-noise ratio of lidar echo signals when performing non-coherent accumulation of echo signals reflected from objects with low reflectivity or at long distances, resulting in low ranging capability of lidar echo signals.
By receiving the echo signal reflected by the object under test, buffering the signal emission angles in multiple dimensions, extracting the target signal corresponding to the preset neighborhood window, and performing non-coherent accumulation, the spatial correlation between the multi-dimensional signal emission angles is used to increase the number of signal accumulations.
This improves the signal-to-noise ratio of the lidar echo signal, thereby enhancing the ranging capability.
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Figure CN116879864B_ABST
Abstract
Description
[0001] This application is a divisional application of Chinese application No. 201980050255.X, the foregoing of which is incorporated herein by reference. Technical Field
[0002] This application relates to the field of lidar technology, and in particular to a lidar echo signal processing method and apparatus. Background Technology
[0003] LiDAR works by emitting a detection signal towards an object, which is then reflected as it passes through the object. The system receives the reflected echo signal and processes it. The signal-to-noise ratio (SNR), a crucial quality indicator in signal processing, determines the ranging capability of the LiDAR. Traditionally, the LiDAR echo signal is accumulated using a one-dimensional non-coherent accumulation method to improve the SNR and thus enhance the ranging capability.
[0004] However, the inventors realized that traditional methods cannot effectively improve the signal-to-noise ratio of lidar echo signals when performing non-coherent accumulation of echo signals reflected from objects with low reflectivity or at a distance, resulting in low ranging capability of lidar echo signals. Summary of the Invention
[0005] According to various embodiments disclosed in this application, a lidar echo signal processing method, apparatus, computer equipment, and storage medium are provided that can improve the ranging capability of lidar echo signals by effectively increasing the signal-to-noise ratio of lidar echo signals.
[0006] A method for processing lidar echo signals includes:
[0007] Receive the echo signal reflected by the object under test, wherein the echo signal includes a multi-dimensional signal transmission angle;
[0008] The echo signal is buffered according to the multi-dimensional signal transmission angle to obtain a buffered signal;
[0009] When the number of cached signals reaches a preset cache size, the target signal corresponding to a preset neighborhood window is extracted from the cached signals; and
[0010] The target signal is non-coherently accumulated, and the accumulated target signal is output.
[0011] A lidar echo signal processing device includes:
[0012] A receiving module is used to receive the echo signal reflected by the object under test, wherein the echo signal includes a multi-dimensional signal transmission angle;
[0013] A buffer module is used to buffer the echo signal according to the multi-dimensional signal transmission angle to obtain a buffered signal;
[0014] The extraction module is used to extract the target signal corresponding to a preset neighborhood window from the cached signals when the number of cached signals reaches a preset cache size; and
[0015] The accumulation module is used to perform non-coherent accumulation of the target signal and output the accumulated target signal.
[0016] A computer device includes a memory and one or more processors, the memory storing computer-readable instructions that, when executed by the processors, cause the one or more processors to perform the following steps:
[0017] Receive the echo signal reflected by the object under test, wherein the echo signal includes a multi-dimensional signal transmission angle;
[0018] The echo signal is buffered according to the multi-dimensional signal transmission angle to obtain a buffered signal;
[0019] When the number of cached signals reaches a preset cache size, the target signal corresponding to a preset neighborhood window is extracted from the cached signals; and
[0020] The target signal is non-coherently accumulated, and the accumulated target signal is output.
[0021] One or more non-volatile computer-readable storage media storing computer-readable instructions, which, when executed by one or more processors, cause the one or more processors to perform the following steps:
[0022] Receive the echo signal reflected by the object under test, wherein the echo signal includes a multi-dimensional signal transmission angle;
[0023] The echo signal is buffered according to the multi-dimensional signal transmission angle to obtain a buffered signal;
[0024] When the number of cached signals reaches a preset cache size, the target signal corresponding to a preset neighborhood window is extracted from the cached signals; and
[0025] The target signal is non-coherently accumulated, and the accumulated target signal is output.
[0026] The embodiments of the present invention also disclose the following examples,
[0027] Example 1: A method for processing lidar echo signals, comprising: receiving an echo signal reflected by an object under test, wherein the echo signal includes a multi-dimensional signal emission angle;
[0028] The echo signal is buffered according to the multi-dimensional signal transmission angle to obtain a buffered signal;
[0029] When the number of cached signals reaches a preset cache size, the target signal corresponding to a preset neighborhood window is extracted from the cached signals; and
[0030] The target signal is non-coherently accumulated, and the accumulated target signal is output.
[0031] Example 2: According to the method described in Example 1, the step of buffering the echo signal based on the multi-dimensional signal transmission angle includes:
[0032] The preset memory corresponding to the echo signal is determined based on the multi-dimensional signal transmission angle and the signal reception sequence of the echo signal; and
[0033] The echo signal is cached in the corresponding preset memory.
[0034] Example 3: According to any one of Examples 1 to 2, the multi-dimensional signal transmission angle includes a first transmission angle and a second transmission angle, and the method further includes:
[0035] Multiple preset memories are arranged into multiple storage rows, with each preset memory corresponding to one storage row. Each preset memory is used to store echo signals with the same first transmission angle corresponding to a preset reception order; and
[0036] The storage columns of multiple preset memories are arranged in a corresponding manner to obtain multiple matrix columns, each matrix column being used to store echo signals with the same second transmission angle.
[0037] Example 4: According to any one of Examples 1 to 3, the step of extracting the target signal corresponding to the preset neighborhood window from the cached signals when the number of cached signals reaches a preset cache number includes:
[0038] When the number of buffered signals reaches a preset buffer limit, historical signals are extracted from the buffered signals according to a preset signal reception order and a preset extraction limit; and
[0039] The target signal corresponding to the preset neighborhood window is obtained based on the extracted historical signal.
[0040] Example 5: The method described according to any one of Examples 1 to 4, further comprising:
[0041] The number of storage rows of the preset neighborhood window is determined according to the number of storage rows corresponding to multiple preset memories. Each storage row of the preset neighborhood window is used to store a buffer signal of the preset signal receiving order extracted from the preset memory. The buffer signals stored in the storage rows of the preset neighborhood window are stored accordingly according to the storage columns of multiple preset memories.
[0042] Example 6. According to any one of Examples 1 to 5, the non-coherent accumulation of the target signal includes: obtaining a corresponding signal sequence based on the target signal; determining the signal length corresponding to the target signal in the signal sequence; and performing non-coherent accumulation of the target signal based on the signal length corresponding to the target signal and a preset relationship.
[0043] Example 7: The method according to any one of Examples 1 to 6, before buffering the echo signal according to the multi-dimensional signal transmission angle, further includes: amplifying the received echo signal to obtain an amplified echo signal; performing analog-to-digital conversion on the amplified echo signal to obtain a converted digital signal; and filtering the converted digital signal.
[0044] Example 8. The method according to any one of Examples 1 to 7, wherein the echo signal includes a signal reception order, and the method further includes: when the number of received echo signals exceeds a preset buffer quantity, taking the echo signals exceeding the buffer quantity as signals to be processed; determining a first signal corresponding to the next preset transmission cycle based on the echo signal with the earliest signal reception order in the buffer signals, and covering the echo signal with the earliest signal reception order based on the first signal; determining a second signal corresponding to the next preset transmission cycle based on the first signal in the buffer signals, and covering the first signal based on the second signal; repeating the step of covering the signal in the buffer signals, covering the buffer signals of the previous preset transmission cycle with the buffer signals of the next preset transmission cycle in the buffer signals, until the signal to be processed covers the buffer signals corresponding to the previous preset transmission cycle; and extracting the target signal corresponding to a preset neighborhood window from the covered buffer signals.
[0045] Example 9. A lidar echo signal accumulation device, comprising: a receiving module for receiving echo signals reflected by an object under test, the echo signals including multi-dimensional signal emission angles; a buffering module for buffering the echo signals according to the multi-dimensional signal emission angles to obtain buffered signals; an extraction module for extracting a target signal corresponding to a preset neighborhood window from the buffered signals when the number of buffered signals reaches a preset buffer quantity; and an accumulation module for performing non-coherent accumulation on the target signals and outputting the accumulated target signals.
[0046] Example 10: According to the apparatus described in Example 9, the buffer module is further configured to determine the preset memory corresponding to the echo signal based on the multi-dimensional signal transmission angle and the signal reception order of the echo signal; and to buffer the echo signal into the corresponding preset memory.
[0047] Example 11. The apparatus according to any one of Examples 9 to 10, the apparatus further comprising: an arrangement module, configured to arrange a plurality of preset memories into a plurality of storage rows, each preset memory corresponding to a storage row, each preset memory being used to store echo signals with the same first transmission angle corresponding to a preset receiving order; and to arrange the storage columns of the plurality of preset memories accordingly to obtain a plurality of matrix columns, each matrix column being used to store echo signals with the same second transmission angle.
[0048] Example 12. According to any one of Examples 9 to 11, the extraction module is further configured to extract historical signals from the cached signals according to a preset signal receiving order and a preset extraction quantity when the number of cached signals reaches a preset cache quantity; and obtain the target signal corresponding to the preset neighborhood window according to the extracted historical signals.
[0049] Example 13. The apparatus according to any one of Examples 9 to 12, the apparatus further comprising: a determining module, configured to determine the number of storage rows of a preset neighborhood window based on the number of storage rows corresponding to a plurality of preset memories, wherein each storage row of the preset neighborhood window is used to store a buffer signal of a preset signal receiving order extracted from the preset memories; and to store the buffer signals stored in the storage rows of the preset neighborhood window according to the storage columns of the plurality of preset memories.
[0050] Example 14. According to any one of Examples 9 to 13, the accumulation module is further configured to acquire a corresponding signal sequence based on the target signal; determine the signal length corresponding to the target signal in the signal sequence; and perform non-coherent accumulation on the target signal based on the signal length corresponding to the target signal and a preset relationship.
[0051] Example 15. The apparatus according to any one of Examples 9 to 14, the apparatus further comprising: a preprocessing module, configured to amplify the received echo signal to obtain an amplified echo signal; perform analog-to-digital conversion on the amplified echo signal to obtain a converted digital signal; and perform filtering on the converted digital signal.
[0052] Example 16. The apparatus according to any one of Examples 9 to 15, further comprising: a coverage module, configured to: when the number of received echo signals exceeds a preset buffer quantity, treat the echo signals exceeding the buffer quantity as signals to be processed; determine a first signal corresponding to the next preset transmission cycle based on the echo signal with the earliest signal reception order in the buffered signals, and cover the echo signal with the earliest signal reception order based on the first signal; determine a second signal corresponding to the next preset transmission cycle based on the first signal in the buffered signals, and cover the first signal based on the second signal; repeat the step of covering the signal in the buffered signals, covering the buffered signals of the previous preset transmission cycle with the buffered signals of the next preset transmission cycle, until the signal to be processed covers the buffered signals corresponding to the previous preset transmission cycle; and extract the target signal corresponding to a preset neighborhood window from the covered buffered signals.
[0053] Details of one or more embodiments of this application are set forth in the following drawings and description. Other features and advantages of this application will become apparent from the specification, drawings, and claims. Attached Figure Description
[0054] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0055] Figure 1 This is an application scenario diagram of the lidar echo signal processing method according to one or more embodiments.
[0056] Figure 2 This is a flowchart illustrating a lidar echo signal processing method according to one or more embodiments.
[0057] Figure 3 This is a flowchart illustrating the steps of extracting the target signal corresponding to a preset neighborhood window from the cached signals when the number of cached signals reaches a preset cache number, according to one or more embodiments.
[0058] Figure 4 This is a flowchart illustrating the lidar echo signal processing method in another embodiment.
[0059] Figure 5 This is a block diagram of a lidar echo signal processing apparatus according to one or more embodiments.
[0060] Figure 6 This is a block diagram of a computer device according to one or more embodiments.
[0061] Figure 7 This is a schematic diagram illustrating the structure of overlaying cached signals in a preset memory and extracting target signals from a preset neighborhood window in the overlaid cached signals, according to an embodiment of the present invention. Detailed Implementation
[0062] To make the technical solutions and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.
[0063] The lidar echo signal processing method provided in this application can be applied to, for example... Figure 1 In the application environment shown, the lidar 102 emits a detection signal, which reflects an echo signal upon encountering the object being measured. The lidar can be a solid-state lidar. The lidar 102 receives the echo signal reflected by the object through a receiver, which can be a silicon photomultiplier tube (SiPM). The lidar 102 sends the echo signal to a computer device 104. The echo signal includes multi-dimensional signal emission angles. The computer device 104 buffers the echo signal based on the multi-dimensional signal emission angles, obtaining a buffered signal. When the number of buffered signals reaches a preset buffer size, the computer device 104 extracts the target signal corresponding to a preset neighborhood window from the buffered signal. The computer device 104 performs non-coherent accumulation on the target signal and outputs the accumulated target signal.
[0064] In one embodiment, such as Figure 2 As shown, a method for processing lidar echo signals is provided, which can be applied to... Figure 1 Taking a computer device as an example, the explanation includes the following steps:
[0065] Step 202: Receive the echo signal reflected by the object under test. The echo signal includes the signal transmission angle in multiple dimensions.
[0066] A lidar system emits a detection signal, which is reflected back upon encountering the object being measured. The lidar then receives this echo signal via a receiver. A computer receives the echo signal transmitted by the lidar. The echo signal can include a preamble, valid echo signal, false echo signal, and ambient noise. The echo signal includes multiple signal transmission angles, such as pitch and yaw. A single pitch angle can correspond to multiple yaw angles, and vice versa. Different signal transmission angles can correspond to independent signal transmission and reception, i.e., different detection and echo signals. The number of signal transmission angles can be determined based on the lidar's single-field-of-view resolution. For example, a solid-state lidar with a single-field-of-view resolution of 76*250 can include 76 pitch angles and 250 yaw angles. The echo signal from these multiple signal transmission angles can be obtained by the lidar scanning its field of view and adjusting the transmission angle of the detection signal. The lidar can first fix the pitch angle and then adjust the yaw angle of the detection signal transmission. When the yaw angle reaches the limit of the angle range, the lidar adjusts the pitch angle, and then adjusts the yaw angle of the subsequent detection signal transmission in the opposite direction to the previous transmission signal, thereby obtaining echo signals of multi-dimensional signal transmission angles.
[0067] In one embodiment, before buffering the echo signal according to the multi-dimensional signal transmission angle, the method further includes: amplifying the received echo signal to obtain an amplified echo signal; performing analog-to-digital conversion on the amplified echo signal to obtain a converted digital signal; and filtering the converted digital signal.
[0068] Computer equipment amplifies weak echo signals for subsequent signal processing. It then performs analog-to-digital conversion on the amplified echo signal to facilitate non-coherent accumulation. Finally, it filters the converted digital signal, removing the DC component, which can be achieved using a high-pass filter. This filtering process helps avoid interference from the DC component.
[0069] Step 204: Buffer the echo signal according to the multi-dimensional signal transmission angle to obtain the buffered signal.
[0070] Step 206: When the number of cached signals reaches the preset cache number, extract the target signal corresponding to the preset neighborhood window from the cached signals.
[0071] Step 208: Perform non-coherent accumulation on the target signal and output the accumulated target signal.
[0072] After receiving an echo signal, the computer device can buffer the echo signal based on multiple dimensions of signal transmission angle. Specifically, the echo signal received by the computer device can also include the signal reception order. The computer device has multiple pre-configured memories. The computer device determines the preset memory corresponding to the echo signal based on the multiple dimensions of signal transmission angle and signal reception order. Then, the computer device buffers the echo signal into the determined preset memory.
[0073] The computer device buffers the echo signals, obtaining buffered signals. The computer device then determines whether the number of buffered signals has reached a preset buffer count. This preset buffer count can be determined by the computer device based on the LiDAR's emission angle. For example, the LiDAR may include 76 elevation angles and 250 yaw angles. The preset buffer count could be 3 * 250.
[0074] When the number of buffered signals in the computer device reaches a preset buffer size, the computer device extracts the target signal corresponding to a preset neighborhood window from the buffered signals. For example, the size of the preset neighborhood window can be 3*3. The preset neighborhood window can be a sliding window.
[0075] The computer device performs noncoherent accumulation of the target signal within a preset neighborhood window. For example, when the preset neighborhood window size is 3x3, the computer device extracts the 1st-3rd, 251st-253rd, and 501st-503rd echo signals (a total of 9 echoes) from the buffered echo signals as the target signal. The computer device performs noncoherent accumulation of the 9 target signals corresponding to the preset neighborhood window. The initial phases between the echo signals undergoing noncoherent accumulation can be random and uncorrelated. Noncoherent accumulation can accumulate echo signals even when phase information is lost, thereby improving the signal-to-noise ratio of the echo signal.
[0076] Traditionally, echo signals are accumulated using a one-dimensional noncoherent accumulation method based on the yaw angle direction. However, this method fails to effectively improve the signal-to-noise ratio (SNR) of the echo signal when dealing with objects with low reflectivity or at a distance, resulting in low ranging capability. In this embodiment, the computer device receives echo signals from multiple signal transmission angles. By utilizing the spatial correlation between these echo signals, the number of noncoherent accumulation iterations can be increased. When the number of buffered echo signals reaches a preset buffer size, the computer device extracts the target signal corresponding to a preset neighborhood window from the buffered echo signals, thereby improving the correlation between target signals. By performing noncoherent accumulation on the target signal corresponding to the preset neighborhood window, the computer device can increase the number of accumulation iterations even when the target signal phase is lost, thus improving the SNR of the echo signal and effectively enhancing its ranging capability.
[0077] In one embodiment, the echo signal is buffered according to the multi-dimensional signal transmission angle, including: determining the preset memory corresponding to the echo signal according to the multi-dimensional signal transmission angle and the signal reception order of the echo signal; and buffering the echo signal into the corresponding preset memory.
[0078] The echo signals received by the computer equipment can include the signal reception order. The signal reception order can be the transmission sequence number corresponding to the echo signal, or the transmission time corresponding to the echo signal. Multiple memories can be pre-configured in the computer equipment. These multiple memories can store the same number of echo signals. Each memory has a corresponding storage capacity. The number of echo signals stored in each memory can be less than or equal to the storage capacity. Multi-dimensional signal transmission angles can include pitch and yaw angles. The same pitch angle can correspond to multiple yaw angles, and the same yaw angle can also correspond to multiple pitch angles. The computer equipment can store multiple echo signals with the same pitch angle but different yaw angles into their corresponding memories. The computer equipment adjusts the pitch angle of the lidar, fixes the adjusted pitch angle, and then adjusts the yaw angle of the lidar in the opposite direction to the previous transmitted detection signal to obtain the echo signal corresponding to the adjusted pitch angle. The computer equipment stores the echo signal corresponding to the adjusted pitch angle into another memory.
[0079] In one embodiment, the multi-dimensional signal transmission angle includes a first transmission angle and a second transmission angle. The method further includes: arranging multiple preset memories into multiple storage rows, each preset memory corresponding to one storage row, and each preset memory being used to store echo signals with the same first transmission angle corresponding to a preset reception order; and arranging the storage columns of the multiple preset memories accordingly to obtain multiple matrix columns, each matrix column being used to store echo signals with the same second transmission angle.
[0080] The computer device arranges multiple preset memories in a corresponding manner. Each preset memory's storage row can store echo signals with the same first transmission angle corresponding to a preset reception order. The preset memories store echo signals with the same second transmission angle into the same matrix column generated from the storage columns of the multiple preset memories. The first transmission angle can be a pitch angle. The second transmission angle can be a yaw angle. This facilitates subsequent signal extraction.
[0081] For example, a computer device can be pre-configured with three memories: a first memory, a second memory, and a third memory. The computer device buffers the first 250 echo signals in the first memory; the pitch angles of these 250 echo signals can be the same, but the yaw angles can be different. The computer device buffers the second 251-500 echo signals in the second memory; the pitch angles of these 251-500 echo signals can be the same, but the yaw angles can be different. The computer device buffers the third 501-750 echo signals; the pitch angles of these 500-750 echo signals can be the same, but the yaw angles can be different. The pitch angles of the first, second, and fifth echo signals can be different, but the yaw angles can be the same.
[0082] In this embodiment, the computer device stores the echo signals into the corresponding preset memory according to the multi-dimensional signal transmission angle and the signal reception order of the echo signals. It can store echo signals with good correlation according to the spatial relationship between adjacent detection signals in the pitch and yaw directions, which is beneficial for the extraction of target signals.
[0083] In one embodiment, such as Figure 3 As shown, the above method also includes the step of extracting the target signal corresponding to the preset neighborhood window from the cached signals when the number of cached signals reaches the preset cache size, specifically including:
[0084] Step 302: When the number of buffered echo signals reaches the preset buffer quantity, historical signals are extracted from the buffered signals according to the preset signal receiving order and the preset extraction quantity.
[0085] Step 304: Obtain the target signal corresponding to the preset neighborhood window based on the extracted historical signals.
[0086] The computer device buffers the echo signals based on multi-dimensional signal transmission angles to obtain buffered signals. The computer device determines whether the number of buffered signals reaches a preset buffer limit. When the number of buffered signals reaches the preset buffer limit, it extracts the target signal corresponding to a preset neighborhood window. The preset neighborhood window can include a preset signal reception order and a preset extraction quantity. The preset signal reception order can be the earliest received echo signals from multiple preset memories corresponding to the buffered signals. The preset extraction quantity can be three echo signals extracted from each preset memory, for a total of nine echo signals. The computer device extracts the three earliest received historical signals from each preset memory and uses these three historical signals as the target signal corresponding to the preset neighborhood window. For example, the computer device extracts the 1st-3rd, 251st-253rd, and 501st-503rd historical signals (a total of nine) from the buffered signals as the target signal.
[0087] In one embodiment, the method further includes: determining the number of storage rows of a preset neighborhood window based on the number of storage rows corresponding to multiple preset memories, wherein each storage row of the preset neighborhood window is used to store a buffer signal of a preset signal receiving order extracted from the preset memory; and storing the buffer signals stored in the storage rows of the preset neighborhood window according to the storage columns of the multiple preset memories.
[0088] In a computer device, the number of storage rows in a preset neighborhood window can be the same as the number of storage rows in a preset memory. Each storage row of the preset neighborhood window is used to store buffered signals retrieved from the preset memory in a preset signal reception order. Each storage row of the preset neighborhood window can store buffered signals with the same pitch angle. The number of storage columns in the preset neighborhood window can be preset. The storage columns of the preset neighborhood window can be used to store buffered signals with the same yaw angle, and the buffered signals in adjacent spaces differ by a preset transmission cycle.
[0089] For example, when the preset cache size is 3 * 250, the preset neighborhood window size can be 3 * 3. The preset signal reception order can be to extract the three earliest cached signals in each memory. The preset extraction count can be 9. The computer device uses the extracted 9 cached signals as the target signal corresponding to the preset neighborhood window.
[0090] In this embodiment, the computer device extracts historical signals from the cached signal according to a preset extraction order and a preset extraction quantity, and obtains the target signal corresponding to the preset neighborhood window. This enables the extraction of historical signals with good correlation, thereby increasing the number of non-coherent accumulations and improving the ranging capability of the echo signal.
[0091] In one embodiment, such as Figure 4 As shown, a method for processing lidar echo signals is provided. Taking the application of this method to a computer device as an example, the method includes the following steps:
[0092] Step 402: Receive the echo signal reflected by the object under test. The echo signal includes the signal transmission angle in multiple dimensions.
[0093] Step 404: Buffer the echo signal according to the multi-dimensional signal transmission angle to obtain the buffered signal.
[0094] Step 406: When the number of cached signals reaches the preset cache number, extract the target signal corresponding to the preset neighborhood window from the cached signals.
[0095] Step 408: Obtain the corresponding signal sequence based on the target signal.
[0096] Step 410: Determine the signal length corresponding to the target signal in the signal sequence.
[0097] Step 412: Perform non-coherent accumulation of the target signal according to the signal length corresponding to the target signal and the preset relationship.
[0098] After extracting the target signal corresponding to a preset neighborhood window, the computer device obtains the corresponding signal sequence based on the target signal. The signal sequence can be a pulse sequence obtained by holding the echo signal at a certain frequency. The signal sequence can be a range gate. The computer device determines the signal length corresponding to the target signal in the signal sequence. The signal length can be the amplitude of the target signal. The data length of the echo signal is L, and the signal length corresponding to the target signal is n, where n can range from [1, L]. Then, the computer device performs non-coherent accumulation of the target signal based on the signal length and a preset relationship. The preset relationship can be a calculation formula for non-coherent accumulation. For example, when the number of extracted target signals is 9, the calculation formula can be as follows:
[0099]
[0100] Where y[n] represents the accumulated target signal, n represents the signal length of each target signal, i represents the number of times the target signal is generated, and L represents the data length of the echo signal.
[0101] In this embodiment, the computer device receives echo signals from multi-dimensional signal transmission angles and utilizes the spatial correlation between these echo signals to increase the number of non-coherent signal accumulations. When the number of buffered signals reaches a preset buffer count, the computer device extracts the target signal corresponding to a preset neighborhood window from the buffered signals, thereby improving the correlation between target signals. By acquiring the signal sequence corresponding to the target signal, determining the signal length of the target signal within the signal sequence, and then performing non-coherent accumulation on the target signal according to a preset relationship, the computer device can accumulate the signal lengths of multiple target signals from the same signal sequence, further improving the signal-to-noise ratio of the echo signal and thus enhancing its ranging capability.
[0102] In one embodiment, the echo signal includes the signal reception order, and the method further includes: when the number of received echo signals exceeds a preset buffer quantity, the echo signals exceeding the buffer quantity are taken as signals to be processed; a first signal corresponding to the next preset transmission cycle is determined based on the echo signal with the earliest signal reception order in the buffer signal, and the echo signal with the earliest signal reception order is covered by the first signal; a second signal corresponding to the next preset transmission cycle is determined based on the first signal in the buffer signal, and the first signal is covered by the second signal; the step of covering the signal in the buffer signal is repeated, and the buffer signal of the next preset transmission cycle is covered by the buffer signal of the previous preset transmission cycle in the buffer signal, until the signal to be processed covers the buffer signal corresponding to the previous preset transmission cycle; the target signal corresponding to the preset neighborhood window is extracted from the covered buffer signal.
[0103] Once the number of buffered signals reaches a preset limit, the computer device can overwrite the buffered signals in the preset memory. Specifically, the computer device is pre-configured with multiple memories, and the computer device treats echo signals exceeding the buffer limit as signals to be processed. Each memory can store echo signals for one preset transmission cycle. One preset transmission cycle can transmit 250 echo signals. The echo signals received by the computer device include the signal reception order. The computer device can first identify the first signal of the next preset transmission cycle corresponding to the earliest received echo signal in the multiple preset memories, and overwrite the signal position of the earliest received echo signal in the memory with the first signal. The computer device then identifies the second signal of the next preset transmission cycle corresponding to the first signal in the multiple preset memories, and overwrites the signal position of the first signal in the memory with the second signal. The computer device repeats the above signal overwriting steps, overwriting the buffered signals of the previous preset transmission cycle with the buffered signals of the next preset transmission cycle, until the signal to be processed overwrites the buffered signal corresponding to the previous preset transmission cycle of the signal to be processed in the buffered signals. After signal coverage is completed, the computer device extracts the target signal corresponding to a preset neighborhood window from the buffered signal after coverage. The preset neighborhood window can be a sliding neighborhood window. When the size of the preset neighborhood window is 3*3, the computer device can extract the buffered signals of times 502-504, 252-254, and 2-4 after coverage for non-coherent accumulation.
[0104] As the cache in the preset memory is overwritten sequentially, the preset neighborhood window can also slide accordingly. The preset neighborhood window includes storage rows and storage columns. The number of storage rows can be the same as the number of preset memories. Each storage row of the preset neighborhood window can include three memories: a first neighborhood memory, a second neighborhood memory, and a third neighborhood memory. The computer device reads the signal stored in the first neighborhood memory and writes it to the second memory. The computer device reads the signal with the earliest received order from the second memory and writes it to the third memory. The first memory retrieves and stores the next echo signal from the preset memory. At this time, the signals stored in the preset neighborhood window are the cached signals of the 502nd-504th, 252nd-254th, and 2nd-4th echoes.
[0105] A schematic diagram of the structure for overwriting cached signals in a preset memory and extracting the target signal of a preset neighborhood window from the overwritten cached signals can be shown as follows: Figure 7 As shown.
[0106] Here, line_ram1 represents the third memory, line_ram2 represents the second memory, and line_ram3 represents the first memory. The signal within the black box can be a signal from a preset neighborhood window extracted from the cached signal.
[0107] For example, a computer device can be pre-configured with three memories: a first memory, a second memory, and a third memory. The preset transmission cycle is 250. The computer device buffers the first 250 echo signals in the first memory, the 251st to 500th echo signals in the second memory, and the 501st to 750th echo signals in the third memory. When the computer device receives the 751st echo signal, the number of echo signals received exceeds the preset buffer size of 750. The earliest received echo signal in the memory is the 1st echo signal. The computer device first identifies the 251st echo signal corresponding to the 1st echo signal in the three memories and overwrites the signal position of the 1st echo signal in the first memory with the 251st echo signal. The computer device then identifies the 501st echo signal corresponding to the 251st echo signal in the three memories and overwrites the signal position of the 251st echo signal in the second memory with the 501st echo signal. The computer device overwrites the signal position of the 501st echo signal in the third memory with the received 751st echo signal. When the preset neighborhood window size is 3*3, the computer device can extract the 502nd-504th, 252nd-254th, and 2nd-4th buffered signals from the overwritten buffered signals and perform non-coherent accumulation.
[0108] For example, when the computer receives the 752nd echo signal, the earliest received echo signal in the memory is the 2nd echo signal. The computer first identifies the 252nd echo signal corresponding to the 2nd echo signal in the three memories, and overwrites the signal position of the 2nd echo signal in the first memory with the 252nd echo signal. The computer then identifies the 502nd echo signal corresponding to the 252nd echo signal in the three memories, and overwrites the signal position of the 252nd echo signal in the second memory with the 502nd echo signal. Finally, the computer overwrites the signal position of the 502nd echo signal in the third memory with the received 752nd echo signal. When the preset neighborhood window size is 3*3, the computer can extract the 502nd-504th, 252nd-254th, and 2nd-4th buffered signals from the overwritten buffered signals for non-coherent accumulation.
[0109] In this embodiment, when the number of received echo signals exceeds a preset buffer size, the computer device covers the corresponding buffered signals based on the echo signals exceeding the buffer size, and extracts the target signal of a preset neighborhood window from the covered buffered signals. This facilitates non-coherent accumulation of the target signal, thereby improving the signal-to-noise ratio of the echo signal.
[0110] It should be understood that, although Figure 1 The steps in flowchart -4 are shown sequentially as indicated by the arrows; however, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order in which these steps are performed, and they can be executed in other orders. Furthermore, Figure 1 At least some of the steps in -4 may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but may be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but may be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.
[0111] In one embodiment, such as Figure 5 As shown, a lidar echo signal processing device is provided, including: a receiving module 502, a buffer module 504, an extraction module 506, and an accumulation module 508, wherein:
[0112] The receiving module 502 is used to receive the echo signal reflected by the object under test. The echo signal includes the signal transmission angle in multiple dimensions.
[0113] The buffer module 504 is used to buffer the echo signal according to the multi-dimensional signal transmission angle to obtain the buffered signal.
[0114] The extraction module 506 is used to extract the target signal corresponding to the preset neighborhood window from the cached signals when the number of cached signals reaches the preset cache number.
[0115] The accumulation module 508 is used to perform non-coherent accumulation of the target signal and output the accumulated target signal.
[0116] In one embodiment, the caching module 504 is further configured to determine the preset memory corresponding to the echo signal based on the multi-dimensional signal transmission angle and the signal reception order of the echo signal; and cache the echo signal in the corresponding preset memory.
[0117] In one embodiment, the above-mentioned device further includes: an arrangement module, configured to arrange multiple preset memories into multiple storage rows, each preset memory corresponding to one storage row, each preset memory being used to store echo signals with the same first transmission angle corresponding to a preset receiving order; and to arrange the storage columns of the multiple preset memories accordingly to obtain multiple matrix columns, each matrix column being used to store echo signals with the same second transmission angle.
[0118] In one embodiment, the extraction module 506 is further configured to extract historical signals from the cached signals according to a preset signal receiving order and a preset extraction quantity when the number of cached signals reaches a preset cache quantity; and obtain the target signal corresponding to the preset neighborhood window based on the extracted historical signals.
[0119] In one embodiment, the above-mentioned apparatus further includes: a determining module, configured to determine the number of storage rows of a preset neighborhood window based on the number of storage rows corresponding to a plurality of preset memories, wherein each storage row of the preset neighborhood window is used to store a buffer signal of a preset signal receiving order extracted from the preset memories; and to store the buffer signals stored in the storage rows of the preset neighborhood window according to the storage columns of the plurality of preset memories.
[0120] In one embodiment, the accumulation module 508 is further configured to acquire a corresponding signal sequence based on the target signal; determine the signal length corresponding to the target signal in the signal sequence; and perform non-coherent accumulation of the target signal based on the signal length corresponding to the target signal and a preset relationship.
[0121] In one embodiment, the above-mentioned apparatus further includes: a preprocessing module, used to amplify the received echo signal to obtain an amplified echo signal; to perform analog-to-digital conversion on the amplified echo signal to obtain a converted digital signal; and to perform filtering on the converted digital signal.
[0122] In one embodiment, the above-mentioned apparatus further includes: a coverage module, configured to, when the number of received echo signals exceeds a preset buffer quantity, treat the echo signals exceeding the buffer quantity as signals to be processed; determine a first signal corresponding to the next preset transmission cycle based on the echo signal with the earliest signal reception order in the buffer signal, and cover the echo signal with the earliest signal reception order based on the first signal; determine a second signal corresponding to the next preset transmission cycle based on the first signal in the buffer signal, and cover the first signal based on the second signal; repeat the step of covering the signal in the buffer signal, covering the buffer signal of the previous preset transmission cycle with the buffer signal of the next preset transmission cycle in the buffer signal, until the signal to be processed covers the buffer signal corresponding to the previous preset transmission cycle; and extract the target signal corresponding to the preset neighborhood window from the covered buffer signal.
[0123] Specific limitations regarding the lidar echo signal processing device can be found in the limitations of the lidar echo signal processing method described above, and will not be repeated here. Each module in the aforementioned lidar echo signal processing device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the operations corresponding to each module.
[0124] In one embodiment, a computer device is provided, the internal structure of which can be shown as follows: Figure 6 As shown, the computer device includes a processor, memory, communication interface, and database connected via a system bus. The processor provides computational and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores the operating system, computer-readable instructions, and the database. The internal memory provides an environment for the operation of the operating system and computer-readable instructions stored in the non-volatile storage medium. The database stores echo signals and target signals. The communication interface is used for communication with a lidar system. When the computer-readable instructions are executed by the processor, a lidar echo signal processing method is implemented.
[0125] Those skilled in the art will understand that Figure 6 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.
[0126] One or more non-volatile computer-readable storage media storing computer-readable instructions, which, when executed by one or more processors, cause the one or more processors to perform the steps in the various method embodiments described above.
[0127] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by instructing related hardware with computer-readable instructions. These computer-readable instructions can be stored in a non-volatile computer-readable storage medium. When executed, these computer-readable instructions can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).
[0128] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0129] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.
Claims
1. A method for processing lidar echo signals, comprising: Detection signals are emitted via lidar; Receive the echo signal reflected by the object under test corresponding to the detection signal, the echo signal including the signal transmission angle in multiple dimensions; The echo signal is buffered according to the multi-dimensional signal transmission angle to obtain a buffered signal; When the number of cached signals reaches a preset cache size, the target signal corresponding to a preset neighborhood window is extracted from the cached signals; and The target signal is non-coherently accumulated, and the accumulated target signal is output. The preset buffer size is determined based on the emission angle of the lidar.
2. The method according to claim 1, characterized in that, The step of buffering the echo signal according to the multi-dimensional signal transmission angle includes: The preset memory corresponding to the echo signal is determined based on the multi-dimensional signal transmission angle and the signal reception sequence of the echo signal; and The echo signal is cached in the corresponding preset memory.
3. The method according to claim 1 or 2, characterized in that, The multi-dimensional signal transmission angle includes a first transmission angle and a second transmission angle, and the method further includes: Multiple preset memories are arranged into multiple storage rows, with each preset memory corresponding to one storage row. Each preset memory is used to store echo signals with the same first transmission angle corresponding to a preset reception order; and The storage columns of multiple preset memories are arranged in a corresponding manner to obtain multiple matrix columns, each matrix column being used to store echo signals with the same second transmission angle.
4. The method according to claim 1 or 2, characterized in that, When the number of cached signals reaches a preset cache size, the target signal corresponding to a preset neighborhood window is extracted from the cached signals, including: When the number of buffered signals reaches a preset buffer limit, historical signals are extracted from the buffered signals according to a preset signal reception order and a preset extraction limit; and The target signal corresponding to the preset neighborhood window is obtained based on the extracted historical signal.
5. The method according to claim 1 or 2, characterized in that, The method further includes: The number of storage rows of the preset neighborhood window is determined according to the number of storage rows corresponding to multiple preset memories. Each storage row of the preset neighborhood window is used to store a buffer signal of the preset signal receiving order extracted from the preset memory. The buffer signals stored in the storage rows of the preset neighborhood window are stored accordingly according to the storage columns of multiple preset memories.
6. A device for accumulating lidar echo signals, comprising: A receiving module is used to receive the echo signal of the corresponding detection signal reflected by the object under test. The echo signal includes a multi-dimensional signal transmission angle, wherein the detection signal is transmitted by a lidar. A buffer module is used to buffer the echo signal according to the multi-dimensional signal transmission angle to obtain a buffered signal; The extraction module is used to extract the target signal corresponding to a preset neighborhood window from the cached signals when the number of cached signals reaches a preset cache size; and The accumulation module is used to perform non-coherent accumulation on the target signal and output the accumulated target signal. The preset buffer size is determined based on the emission angle of the lidar.
7. The apparatus according to claim 6, characterized in that, The caching module is further configured to determine the preset memory corresponding to the echo signal based on the multi-dimensional signal transmission angle and the signal reception order of the echo signal; and to cache the echo signal into the corresponding preset memory.
8. The apparatus according to claim 6 or 7, characterized in that, The device further includes: an arrangement module for arranging multiple preset memories into multiple storage rows, each preset memory corresponding to one storage row, each preset memory being used to store echo signals with the same first transmission angle corresponding to a preset receiving order; and arranging the storage columns of the multiple preset memories accordingly to obtain multiple matrix columns, each matrix column being used to store echo signals with the same second transmission angle.
9. The apparatus according to claim 6 or 7, characterized in that, The extraction module is also used to extract historical signals from the cached signals according to a preset signal receiving order and a preset extraction quantity when the number of cached signals reaches a preset cache quantity; and to obtain the target signal corresponding to a preset neighborhood window based on the extracted historical signals.
10. The apparatus according to claim 6 or 7, characterized in that, The device further includes: a determining module, configured to determine the number of storage rows of a preset neighborhood window based on the number of storage rows corresponding to multiple preset memories, wherein each storage row of the preset neighborhood window is used to store a buffer signal of a preset signal receiving order extracted from the preset memory; and to store the buffer signals stored in the storage rows of the preset neighborhood window according to the storage columns of the multiple preset memories.