A pulse signal preprocessing method and system

Abstract

The present invention relates to the field of signal processing technology, and specifically to a pulse signal preprocessing method and system. The system includes a laser radar module, a clock circuit, an analog-to-digital conversion circuit and an FPGA processing module. The method includes: receiving a radar wave analog signal and a clock signal generated by a clock circuit through the analog-to-digital conversion circuit, and generating a digital sampling wave based on the radar wave analog signal and the clock signal; determining whether the digital sampling wave is within a preset threshold range through the FPGA processing module, and if it is determined that the amplitude of the digital sampling wave is within the preset threshold range, determining the peak value of a digital transmission wave and the peak value of a digital reflection wave in the digital sampling wave; determining the time difference between the peak value of the digital transmission wave and the peak value of the digital reflection wave through the FPGA processing module, and determining the measurement distance of the laser radar module based on the time difference; the present invention can improve the accuracy of pulse signal preprocessing.

Description

Technical Field

[0001] The present invention relates to the technical field of signal processing, and in particular to a pulse signal preprocessing method and system. Background Art

[0002] In a LiDAR system, the raw data received is usually a series of pulse signals, which are captured by the sensor and transmitted to the processing unit. Due to factors such as environmental noise and the scattering characteristics of the target object, the original pulse signals often carry a lot of noise and clutter. Therefore, these pulse signals need to be preprocessed to extract target information and remove or suppress noise signals, thereby improving the accuracy and efficiency of subsequent processing.

[0003] In related technologies, laser radar pulse signal preprocessing technology mainly uses filters to filter out noise signals and retain target signals by controlling the frequency characteristics of the filters. However, traditional filter methods may be difficult to adapt to complex and changing environments and target characteristics, and may easily lead to signal distortion or information loss. Summary of the invention

[0004] In view of this, an object of the embodiments of the present invention is to provide a pulse signal preprocessing method and system to solve one or more technical problems existing in the prior art and to provide at least one beneficial option or create conditions.

[0005] On the one hand, an embodiment of the present invention provides a pulse signal preprocessing method, which is applied to a pulse signal preprocessing system, wherein the pulse signal preprocessing system includes a laser radar module, a clock circuit, an analog-to-digital conversion circuit, and an FPGA processing module. The method includes the following steps:

[0006] The radar wave analog signal and the clock signal generated by the clock circuit are received by the analog-to-digital conversion circuit, and a digital sampling wave is generated based on the radar wave analog signal and the clock signal; wherein the radar wave analog signal includes an analog transmission wave and an analog reflection wave, and the digital sampling wave includes a plurality of continuous sampling time periods and corresponding digital sampling values, and the digital sampling values ​​are generated based on the digital sampling wave, and the sampling time period is generated based on the clock signal; the digital sampling wave includes a digital transmission wave and a digital reflection wave; the radar wave analog signal is generated based on the radar pulse wave signal output by the laser radar module;

[0007] Determine whether the digital sampling wave is within a preset threshold range through the FPGA processing module, and if it is determined that the amplitude of the digital sampling wave is within the preset threshold range, determine the peak value of the digital transmission wave and the peak value of the digital reflection wave in the digital sampling wave;

[0008] The time difference between the peak value of the digital transmission wave and the peak value of the digital reflection wave is determined by the FPGA processing module, and the measurement distance of the laser radar module is determined based on the time difference.

[0009] Optionally, generating a digital sampling wave based on the radar wave analog signal and the clock signal includes:

[0010] Obtaining a clock period of the clock signal;

[0011] The radar wave analog signal is collected by the analog-to-digital conversion circuit, and the time for the analog-to-digital conversion circuit to collect the radar wave analog signal is divided into a plurality of continuous sampling time periods according to the clock cycle;

[0012] The radar wave analog signal of each sampling time period is converted into a corresponding digital sampling value, and a plurality of the sampling time periods and the corresponding digital sampling values ​​are used as the digital sampling wave.

[0013] Optionally, the determining a peak value of a digital transmission wave and a peak value of a digital reflection wave in the digital sampling wave comprises:

[0014] Screening the digital sampling values ​​whose amplitudes in the digital sampling wave are within the threshold range to obtain a sampling area containing a plurality of digital sampling values;

[0015] Taking 3 consecutive sampling points as a group, traverse the digital sampling values ​​in the sampling area and select 3 consecutive target sampling points; wherein the amplitude of the sampling point located in the middle of the 3 consecutive target sampling points is the largest;

[0016] The peak value of the digital sampling wave is determined based on the three consecutive target sampling points.

[0017] Optionally, the pulse signal preprocessing system further includes a signal conditioning circuit, wherein the signal conditioning circuit is connected between the laser radar module and the analog-to-digital conversion circuit, and the method further includes:

[0018] The radar pulse wave signal output by the laser radar module is received by the signal adjustment circuit, and after the radar pulse wave signal gain is adjusted to a radar wave analog signal, it is sent to the analog-to-digital conversion circuit.

[0019] Optionally, after determining whether the digital sampling wave is within a preset threshold range by the FPGA processing module, the method further includes:

[0020] When it is determined that the digital sampling wave deviates from a preset threshold range, the gain coefficient of the digitally controlled variable gain amplifier is controlled by the FPGA processing module to adjust the radar pulse wave signal to a radar wave analog signal with an amplitude within the threshold range.

[0021] On the other hand, an embodiment of the present invention provides a pulse signal preprocessing system, the pulse signal preprocessing system comprising a laser radar module, a clock circuit, an analog-to-digital conversion circuit and an FPGA processing module;

[0022] The analog-to-digital conversion circuit is used to receive the radar wave analog signal and the clock signal generated by the clock circuit, and generate a digital sampling wave based on the radar wave analog signal and the clock signal; wherein the radar wave analog signal includes an analog transmission wave and an analog reflection wave, and the digital sampling wave includes a plurality of continuous sampling time periods and corresponding digital sampling values, and the digital sampling values ​​are generated based on the digital sampling wave, and the sampling time period is generated based on the clock signal; the digital sampling wave includes a digital transmission wave and a digital reflection wave; the radar wave analog signal is generated based on the radar pulse wave signal output by the laser radar module;

[0023] The FPGA processing module is used to determine whether the digital sampling wave is within a preset threshold range. If it is determined that the amplitude of the digital sampling wave is within the preset threshold range, the peak value of the digital transmission wave and the peak value of the digital reflection wave in the digital sampling wave are determined, and then the time difference between the peak value of the digital transmission wave and the peak value of the digital reflection wave is determined, and the measurement distance of the laser radar module is determined based on the time difference.

[0024] Optionally, generating a digital sampling wave based on the radar wave analog signal and the clock signal includes:

[0025] Obtaining a clock period of the clock signal;

[0026] The radar wave analog signal is collected by the analog-to-digital conversion circuit, and the time for the analog-to-digital conversion circuit to collect the radar wave analog signal is divided into a plurality of continuous sampling time periods according to the clock cycle;

[0027] The radar wave analog signal of each sampling time period is converted into a corresponding digital sampling value, and a plurality of the sampling time periods and the corresponding digital sampling values ​​are used as the digital sampling wave.

[0028] Optionally, the determining a peak value of a digital transmission wave and a peak value of a digital reflection wave in the digital sampling wave comprises:

[0029] Screening the digital sampling values ​​whose amplitudes in the digital sampling wave are within the threshold range to obtain a sampling area containing a plurality of digital sampling values;

[0030] Taking 3 consecutive sampling points as a group, traverse the digital sampling values ​​in the sampling area and select 3 consecutive target sampling points; wherein the amplitude of the sampling point located in the middle of the 3 consecutive target sampling points is the largest;

[0031] The peak value of the digital sampling wave is determined based on the three consecutive target sampling points.

[0032] Optionally, the pulse signal preprocessing system further includes a signal conditioning circuit, wherein the signal conditioning circuit is connected between the laser radar module and the analog-to-digital conversion circuit;

[0033] The signal adjustment circuit is used to receive the radar pulse wave signal output by the laser radar module, adjust the gain of the radar pulse wave signal into a radar wave analog signal, and then send it to the analog-to-digital conversion circuit.

[0034] Optionally, the FPGA processing module is further used for:

[0035] When it is determined that the digital sampling wave deviates from a preset threshold range, the gain coefficient of the digitally controlled variable gain amplifier is controlled by the FPGA processing module to adjust the radar pulse wave signal to a radar wave analog signal with an amplitude within the threshold range.

[0036] The embodiments of the present invention include the following beneficial effects: In this embodiment, the radar wave analog signal is converted into a digital sampling wave through an analog-to-digital conversion circuit, and the original signal waveform can be retained; the digital sampling wave is compared with a preset threshold range through an FPGA processing module, and the amplitude of the digital sampling wave is adjusted to within the threshold range by adjusting the gain of the radar pulse wave signal; the peak value of the digital transmission wave and the peak value of the digital reflection wave are processed by the data processing module, so that the measurement distance of the laser radar module can be quickly and accurately determined. The present invention can improve the accuracy of pulse signal preprocessing. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0038] Figure 1 1 is a schematic diagram of a step flow of a pulse signal preprocessing method provided by an embodiment of the present invention;

[0039] Figure 2 is a structural block diagram of a pulse signal preprocessing system provided by an embodiment of the present invention;

[0040] Figure 3 is a waveform diagram of a radar wave simulation signal in an embodiment of the present invention;

[0041] Figure 4 It is a sampling diagram of the digital sampling wave in the embodiment of the present invention. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0043] It should be noted that, although the device schematic diagram is divided into modules and the flow chart shows a logical order, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flow chart. The terms "first", "second", etc. in the specification, claims and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0045] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present application. However, those skilled in the art will appreciate that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, known methods, devices, realizations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0046] The block diagrams shown in the accompanying drawings are only functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software form, or in one or more hardware charging modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0047] The flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0048] First, several technical terms involved in the present invention are explained below;

[0049] FPGA processing module: Field-Programmable Gate Array (Field Programmable Gate Array);

[0050] Analog-to-digital converter circuit: Analog-to-digital converter (analog-to-digital converter);

[0051] SPI: Serial Peripheral Interface (serial peripheral interface);

[0052] LVDS: Low-Voltage Differential Signaling;

[0053] In related technologies, the analog signals received by LiDAR often have a high frequency and dynamic range, and need to be converted by analog-to-digital conversion circuit chips before they can be processed and analyzed in the digital domain. The performance of analog-to-digital conversion circuit chips directly affects important indicators such as the system's sampling accuracy, signal-to-noise ratio, and power consumption.

[0054] The analog-to-digital conversion circuit chip has a high sampling rate and resolution, and can accurately convert analog signals into digital signals while retaining the original waveform characteristics of the signal.

[0055] Based on this, in order to solve the technical problems in the background technology, the present invention provides a pulse signal preprocessing method and system, which realizes the rapid and accurate conversion of analog signals to digital signals by using analog-to-digital conversion circuit chips, and provides a reliable data basis for subsequent digital signal processing. Using FPGA processing modules for digital signal processing can realize high-performance, low-latency real-time data processing, and provide reliable data support for the subsequent.

[0056] like Figure 1 and Figure 2 As shown, a pulse signal preprocessing method provided by an embodiment of the present invention is applied to a pulse signal preprocessing system, the pulse signal preprocessing system includes a laser radar module, a clock circuit, an analog-to-digital conversion circuit and an FPGA processing module, and the method includes the following steps:

[0057] S100, receiving a radar wave analog signal and a clock signal generated by a clock circuit through an analog-to-digital conversion circuit, and generating a digital sampling wave based on the radar wave analog signal and the clock signal; wherein the radar wave analog signal includes an analog transmission wave and an analog reflection wave, the digital sampling wave includes a plurality of continuous sampling time periods and corresponding digital sampling values, the digital sampling values ​​are generated based on the digital sampling wave, and the sampling time period is generated based on the clock signal; the digital sampling wave includes a digital transmission wave and a digital reflection wave; the radar wave analog signal is generated based on a radar pulse wave signal output by a laser radar module;

[0058] S200, determining whether the digital sampling wave is within a preset threshold range through the FPGA processing module, and if it is determined that the amplitude of the digital sampling wave is within the preset threshold range, determining the peak value of the digital transmission wave and the peak value of the digital reflection wave in the digital sampling wave;

[0059] S300, determining the time difference between the peak value of the digital transmission wave and the peak value of the digital reflection wave through the FPGA processing module, and determining the measurement distance of the laser radar module based on the time difference.

[0060] In the embodiment provided by the present invention, the pulse signal preprocessing circuit is used to convert the radar wave analog signal into a stable digital signal. The pulse signal preprocessing circuit includes a signal conditioning circuit, a clock circuit, an analog-to-digital conversion circuit, and an FPGA processing module. The signal conditioning circuit uses a digitally controlled variable gain amplifier of model LMH6521SQ / NOPB to regulate the signal; the clock circuit uses a clock generator of model CDCE62002 chip to generate an LVDS clock signal, and provides an LVDS clock signal for the MXT2001E chip; the analog-to-digital conversion circuit uses the MXT2001E chip to convert the radar wave analog signal into a digital signal, and the FPGA processing module is responsible for preprocessing the data.

[0061] Specifically, the FPGA processing module configures the analog-to-digital conversion circuit to DDR mode or SDR mode through the SPI interface. For example, in the single data rate SDR mode, the speed of the radar wave simulation signal is 1 / 2 of the input clock; in the double data rate DDR mode, the speed of the radar wave simulation signal is 1 / 4 of the input clock. The analog-to-digital conversion circuit requires a clock for sampling, and a clock circuit is added to the input end of the analog-to-digital conversion circuit (FPGA processing module configuration). Considering that the radar wave simulation signal may be too large or too small, a signal conditioning circuit is set at the front end of the analog-to-digital conversion circuit. If the radar wave simulation signal is too small, it may be considered not to be an obstacle echo, but may be rain, fog, or water droplets, etc.; if the radar wave simulation signal is too large, it will cause test errors.

[0062] In this embodiment, the analog-to-digital conversion circuit receives the radar wave analog signal output by the laser radar module and converts it into a digital signal for subsequent digital signal processing. The analog-to-digital conversion circuit uses the SPI interface and the LVDS interface to communicate with the FPGA processing module; the analog-to-digital conversion circuit can accurately convert the radar wave analog signal into a digital signal, retaining the original signal waveform. The FPGA processing module is responsible for receiving the digital signal output by the analog-to-digital conversion circuit, and calculating and processing to obtain the measured distance. By multiplying the time difference and the transmission rate of the radar wave and dividing it by 2, the measured distance of the laser radar module can be obtained.

[0063] like Figure 3 and Figure 4As shown, in some embodiments, generating a digital sampling wave based on a radar wave analog signal and a clock signal includes:

[0064] S110, obtaining a clock period of a clock signal;

[0065] S120, collecting the radar wave analog signal through the analog-to-digital conversion circuit, and dividing the time for the analog-to-digital conversion circuit to collect the radar wave analog signal into a plurality of continuous sampling time periods according to the clock cycle;

[0066] S130, converting the radar wave analog signal of each sampling time period into a corresponding digital sampling value, and using the multiple sampling time periods and the corresponding digital sampling values ​​as digital sampling waves.

[0067] In the embodiment provided by the present invention, by using the clock cycle of the clock signal to divide the sampling time period, the accuracy and consistency of the sampling can be ensured, thereby improving the accuracy of the analog-to-digital conversion. By using the clock signal and the radar wave analog signal for synchronous sampling, the temporal correspondence between the sampled waveform and the original signal can be guaranteed, and the phase error in the sampling process can be avoided. By adjusting the clock cycle, the sampling rate can be flexibly changed to adapt to radar wave analog signals with different frequency characteristics and meet the needs of different application scenarios. The sampling time period and the corresponding digital sampling value are matched one by one to ensure the integrity and consistency of the data, which is convenient for subsequent data processing and analysis. By converting the radar wave analog signal into a digital sampling wave, the digital sampling wave can be efficiently analyzed and processed using digital signal processing technology.

[0068] In some embodiments, determining a peak value of a digital transmission wave and a peak value of a digital reflection wave in a digital sampling wave includes:

[0069] S210, screening digital sampling values ​​in the digital sampling wave whose amplitudes are within the threshold range, to obtain a sampling region containing a plurality of digital sampling values;

[0070] S220, taking three consecutive sampling points as a group, traversing the digital sampling values ​​in the sampling area, and selecting three consecutive target sampling points; wherein the amplitude of the sampling point located in the middle of the three consecutive target sampling points is the largest;

[0071] S230: Determine a peak value of the digital sampling wave based on the three consecutive target sampling points.

[0072] refer to Figure 3 , Figure 3 The threshold range in the example is for the digital sampling wave generated by the radar wave simulation signal. Since the amplitude of the radar wave simulation signal and the digital sampling wave are the same, the threshold range is superimposed on the radar wave simulation signal for the convenience of intuitive display.

[0073] Specifically, the amplitude of the sampling point located in the middle of the three consecutive target sampling points is taken as the peak value of the digital sampling wave;

[0074] Alternatively, a polynomial is used to fit the digital sampling values ​​in the sampling area to obtain a fitting polynomial; the derivative of the fitting polynomial is calculated, and the digital sampling values ​​with zero derivative are taken as potential peak points; the maximum value of each potential peak point in the digital sampling wave is taken as the peak value of the digital sampling wave.

[0075] In this embodiment, the peak value of the digital sampling wave is determined by taking the highest point and its two adjacent sampling points on the left and right, which can ensure accuracy while greatly reducing the amount of calculation and calculation time. Specifically, a sampling area containing a peak is selected, and the sampling area includes 3 consecutive sampling points within the threshold range. Since the amplitude of the sampling point located in the middle of the area containing the peak is the largest, based on this, the area that may contain the peak can be screened out. The maximum value of the amplitudes of the three consecutive target sampling points is approximately regarded as the peak value of the digital sampling wave, so as to quickly determine the peak point; or the peak point is determined by polynomial fitting, so as to accurately determine the peak point. The embodiment provided by the present invention can adapt to different signal characteristics, and can effectively determine the peak value whether it is a smooth signal or a noisy signal. It has a certain robustness to noise and outliers in the data and can provide a stable peak estimation.

[0076] In some embodiments, the pulse signal preprocessing system further includes a signal conditioning circuit, the signal conditioning circuit is connected between the laser radar module and the analog-to-digital conversion circuit, and the method further includes:

[0077] The radar pulse wave signal output by the laser radar module is received through the signal conditioning circuit, and after the radar pulse wave signal gain is adjusted to a radar wave analog signal, it is sent to the analog-to-digital conversion circuit.

[0078] In this embodiment, the radar pulse wave signal is amplified or reduced by the signal conditioning circuit with variable gain, and the amplitude of the received radar pulse signal can be adjusted to adapt to different signal strengths and noise levels, so as to improve the accuracy and efficiency of pulse signal preprocessing. It can be understood that the radar pulse wave signal received by the signal conditioning circuit is an analog signal, and the output is also a radar wave analog signal.

[0079] In some embodiments, after determining whether the digital sampling wave is within a preset threshold range through the FPGA processing module, the method further includes:

[0080] When it is determined that the digital sampling wave deviates from a preset threshold range, the gain coefficient of the digitally controlled variable gain amplifier is controlled by the FPGA processing module to adjust the radar pulse wave signal to a radar wave analog signal with an amplitude within the threshold range.

[0081] In this embodiment, by comparing the digital sampling wave with the preset threshold range, the distorted radar wave analog signal is eliminated to avoid the subsequent wrong measurement distance. It should be noted that the echo may not be an obstacle, but may be rain, fog, water droplets, etc.; if the digital sampling wave deviates from the threshold range, the digital sampling wave is sent to the FPGA processing module without analysis and processing, but the next digital sampling wave is received until the digital sampling wave within the threshold range is received. If the peak point and its two adjacent points in the digital sampling wave obtained after amplification are close, or the peak point in the digital sampling wave is greater than the maximum value of the ADC output, it is judged that there is an error in the measured distance, and the radar wave analog signal is received again.

[0082] If the digital sampling waves received multiple times all deviate from the threshold range, it means that the amplitude of the radar wave analog signal obtained by adjusting the radar pulse wave signal is difficult to meet the needs. By controlling the gain coefficient of the digitally controlled variable gain amplifier through the FPGA processing module, a digital sampling wave with an amplitude within the threshold range can be obtained, thereby obtaining an effective peak value and achieving accurate ranging.

[0083] Specifically, when the radar wave analog signal is too large, assuming that the data bit width output by the analog-to-digital conversion circuit is 8 bits, the maximum value of the threshold range is 2^8, that is, 255, and the potential peak point and its two adjacent points are used as three consecutive sampling points:

[0084] Case 1: The values ​​of three consecutive sampling points are all greater than or equal to 255, the maximum value cannot be determined, and the measurement distance cannot be calculated.

[0085] Case 2: The first sampling point is greater than or equal to 255, the second is greater than, equal to, or less than 255, and the third is also less than 255. In this case, the maximum value cannot be determined and the measurement distance cannot be calculated.

[0086] Case 3: The first sampling point is greater than the threshold and less than 255, the second sampling point is greater than or equal to 255, and the third sampling point is less than 255. The calculated measurement distance has an error.

[0087] In the above three cases, the gain of the radar pulse wave signal is adjusted by controlling the digitally controlled variable gain amplifier through the FPGA processing module, and the amplitude of the obtained radar wave analog signal is within the threshold range, thereby ensuring that the digital sampling wave is also within the threshold range.

[0088] See again Figure 2 , an embodiment of the present invention provides a pulse signal preprocessing system, the pulse signal preprocessing system includes a laser radar module, a clock circuit, an analog-to-digital conversion circuit and an FPGA processing module;

[0089] The analog-to-digital conversion circuit is used to receive the radar wave analog signal and the clock signal generated by the clock circuit, and generate a digital sampling wave based on the radar wave analog signal and the clock signal; wherein the radar wave analog signal includes an analog transmission wave and an analog reflection wave, the digital sampling wave includes a plurality of continuous sampling time periods and corresponding digital sampling values, the digital sampling values ​​are generated based on the digital sampling wave, and the sampling time period is generated based on the clock signal; the digital sampling wave includes a digital transmission wave and a digital reflection wave; the radar wave analog signal is generated based on the radar pulse wave signal output by the laser radar module;

[0090] The FPGA processing module is used to determine whether the digital sampling wave is within a preset threshold range. If it is determined that the amplitude of the digital sampling wave is within the preset threshold range, the peak value of the digital transmission wave and the peak value of the digital reflection wave in the digital sampling wave are determined, and then the time difference between the peak value of the digital transmission wave and the peak value of the digital reflection wave is determined, and the measurement distance of the lidar module is determined based on the time difference.

[0091] It can be seen that the contents of the above method embodiments are all applicable to the present system embodiments, the functions specifically implemented by the present system embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0092] See again Figure 3 and Figure 4 In some embodiments, generating a digital sampling wave based on a radar wave analog signal and a clock signal includes:

[0093] Get the clock period of the clock signal;

[0094] The radar wave analog signal is collected by the analog-to-digital conversion circuit, and the time for the analog-to-digital conversion circuit to collect the radar wave analog signal is divided into a plurality of continuous sampling time periods according to the clock cycle;

[0095] The radar wave analog signal of each sampling time period is converted into a corresponding digital sampling value, and multiple sampling time periods and corresponding digital sampling values ​​are used as digital sampling waves.

[0096] In the embodiment provided by the present invention, by using the clock cycle of the clock signal to divide the sampling time period, the accuracy and consistency of the sampling can be ensured, thereby improving the accuracy of the analog-to-digital conversion. By using the clock signal and the radar wave analog signal for synchronous sampling, the temporal correspondence between the sampled waveform and the original signal can be guaranteed, and the phase error in the sampling process can be avoided. By adjusting the clock cycle, the sampling rate can be flexibly changed to adapt to radar wave analog signals with different frequency characteristics and meet the needs of different application scenarios. The sampling time period and the corresponding digital sampling value are matched one by one to ensure the integrity and consistency of the data, which is convenient for subsequent data processing and analysis. By converting the radar wave analog signal into a digital sampling wave, the signal can be efficiently analyzed and processed using digital signal processing technology.

[0097] In some embodiments, determining a peak value of a digital transmission wave and a peak value of a digital reflection wave in a digital sampling wave includes:

[0098] Screening the digital sampling values ​​whose amplitudes in the digital sampling wave are within the threshold range to obtain a sampling area containing a plurality of digital sampling values;

[0099] Taking 3 consecutive sampling points as a group, traverse the digital sampling values ​​in the sampling area and select 3 consecutive target sampling points; wherein the amplitude of the sampling point located in the middle of the 3 consecutive target sampling points is the largest;

[0100] The peak value of the digital sampling wave is determined based on the three consecutive target sampling points.

[0101] In some embodiments, the pulse signal preprocessing system further includes a signal conditioning circuit, wherein the signal conditioning circuit is connected between the laser radar module and the analog-to-digital conversion circuit;

[0102] The signal conditioning circuit is used to receive the radar pulse wave signal output by the laser radar module, adjust the radar pulse wave signal gain to a radar wave analog signal, and then send it to the analog-to-digital conversion circuit.

[0103] In this embodiment, the radar pulse wave signal is amplified by a variable gain through a signal conditioning circuit, and the amplitude of the received radar pulse signal can be adjusted to adapt to different signal strengths and noise levels, thereby improving the accuracy and efficiency of pulse signal preprocessing.

[0104] In some embodiments, the FPGA processing module is further configured to:

[0105] When it is determined that the digital sampling wave deviates from a preset threshold range, the gain coefficient of the digitally controlled variable gain amplifier is controlled by the FPGA processing module to adjust the radar pulse wave signal to a radar wave analog signal with an amplitude within the threshold range.

[0106] In this embodiment, by comparing the digital sampling wave with a preset threshold range, the distorted radar wave analog signal is excluded, thereby avoiding the subsequent wrong measurement distance.

[0107] Those skilled in the art will appreciate that all or some of the steps in the methods disclosed above, and the functional charging modules / units in the systems and devices may be implemented as software, firmware, hardware, or appropriate combinations thereof.

[0108] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example: a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0109] It should be understood that in this application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0110] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0111] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0112] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0113] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including multiple instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, referred to as ROM), random access memory (Random Access Memory, referred to as RAM), disk or optical disk and other media that can store programs.

[0114] The preferred embodiments of the present invention are described above with reference to the accompanying drawings, but the scope of the rights of the present invention is not limited thereto. Any modification, equivalent substitution and improvement made by a person skilled in the art without departing from the scope and essence of the present invention should be within the scope of the rights of the present invention.

Claims

1. A pulse signal preprocessing method, characterized in that: Applied to a pulse signal preprocessing system, the pulse signal preprocessing system includes a laser radar module, a clock circuit, an analog-to-digital conversion circuit and an FPGA processing module, and the method includes the following steps: The radar wave analog signal and the clock signal generated by the clock circuit are received by the analog-to-digital conversion circuit, and a digital sampling wave is generated based on the radar wave analog signal and the clock signal; wherein the radar wave analog signal includes an analog transmission wave and an analog reflection wave, and the digital sampling wave includes a plurality of continuous sampling time periods and corresponding digital sampling values, and the digital sampling values ​​are generated based on the digital sampling wave, and the sampling time period is generated based on the clock signal; the digital sampling wave includes a digital transmission wave and a digital reflection wave; the radar wave analog signal is generated based on the radar pulse wave signal output by the laser radar module; Determine whether the digital sampling wave is within a preset threshold range through the FPGA processing module, and if it is determined that the amplitude of the digital sampling wave is within the preset threshold range, determine the peak value of the digital transmission wave and the peak value of the digital reflection wave in the digital sampling wave; Determine the time difference between the peak value of the digital transmission wave and the peak value of the digital reflection wave through the FPGA processing module, and determine the measurement distance of the laser radar module based on the time difference; The step of generating a digital sampling wave based on the radar wave analog signal and the clock signal comprises: Obtaining a clock period of the clock signal; The radar wave analog signal is collected by the analog-to-digital conversion circuit, and the time for the analog-to-digital conversion circuit to collect the radar wave analog signal is divided into a plurality of continuous sampling time periods according to the clock cycle; Convert the radar wave analog signal of each sampling time period into a corresponding digital sampling value, and use the plurality of sampling time periods and the corresponding digital sampling values ​​as the digital sampling wave; The step of determining a peak value of a digital transmission wave and a peak value of a digital reflection wave in the digital sampling wave comprises: Screening the digital sampling values ​​whose amplitudes in the digital sampling wave are within the threshold range to obtain a sampling area containing a plurality of digital sampling values; Taking 3 consecutive sampling points as a group, traverse the digital sampling values ​​in the sampling area and select 3 consecutive target sampling points; wherein the amplitude of the sampling point located in the middle of the 3 consecutive target sampling points is the largest; Determine the peak value of the digital sampling wave based on the three consecutive target sampling points; Specifically, the amplitude of the sampling point located in the middle of the three consecutive target sampling points is taken as the peak value of the digital sampling wave; Alternatively, a polynomial is used to fit the digital sampling values ​​in the sampling area to obtain a fitting polynomial; a derivative of the fitting polynomial is calculated, and the digital sampling value with a derivative of zero is taken as a potential peak point; and the maximum value of each potential peak point in the digital sampling wave is taken as the peak value of the digital sampling wave; After determining whether the digital sampling wave is within a preset threshold range by the FPGA processing module, the method further includes: When it is determined that the digital sampling wave deviates from a preset threshold range, the gain coefficient of the digitally controlled variable gain amplifier is controlled by the FPGA processing module to adjust the radar pulse wave signal to a radar wave analog signal whose amplitude is within the threshold range; If the digital sampling wave deviates from the preset threshold range, the digital sampling wave is sent to the FPGA processing module without being analyzed and processed, but the next digital sampling wave is received until a digital sampling wave within the threshold range is received; If the peak point of the digital sampling wave obtained after amplification and its two adjacent points are close, or the peak point of the digital sampling wave is greater than the maximum value of the ADC output, it is determined that there is an error in the measured distance and the radar wave analog signal is received again; If the digital sampling waves received multiple times all deviate from the threshold range, the gain coefficient of the digitally controlled variable gain amplifier is controlled by the FPGA processing module to obtain a digital sampling wave with an amplitude within the threshold range, thereby obtaining a valid peak value and achieving accurate ranging.

2. The method according to claim 1, characterized in that The pulse signal preprocessing system further includes a signal conditioning circuit, wherein the signal conditioning circuit is connected between the laser radar module and the analog-to-digital conversion circuit. The method further includes: The radar pulse wave signal output by the laser radar module is received by the signal adjustment circuit, and after the radar pulse wave signal gain is adjusted to a radar wave analog signal, it is sent to the analog-to-digital conversion circuit.

3. A pulse signal preprocessing system, characterized in that: A pulse signal preprocessing system, the pulse signal preprocessing system comprising a laser radar module, a clock circuit, an analog-to-digital conversion circuit and an FPGA processing module; The analog-to-digital conversion circuit is used to receive the radar wave analog signal and the clock signal generated by the clock circuit, and generate a digital sampling wave based on the radar wave analog signal and the clock signal; wherein the radar wave analog signal includes an analog transmission wave and an analog reflection wave, and the digital sampling wave includes a plurality of continuous sampling time periods and corresponding digital sampling values, and the digital sampling values ​​are generated based on the digital sampling wave, and the sampling time period is generated based on the clock signal; the digital sampling wave includes a digital transmission wave and a digital reflection wave; the radar wave analog signal is generated based on the radar pulse wave signal output by the laser radar module; The FPGA processing module is used to determine whether the digital sampling wave is within a preset threshold range. If it is determined that the amplitude of the digital sampling wave is within the preset threshold range, then determine the peak value of the digital transmission wave and the peak value of the digital reflection wave in the digital sampling wave, and then determine the time difference between the peak value of the digital transmission wave and the peak value of the digital reflection wave, and determine the measurement distance of the laser radar module based on the time difference; The step of generating a digital sampling wave based on the radar wave analog signal and the clock signal comprises: Obtaining a clock period of the clock signal; The radar wave analog signal is collected by the analog-to-digital conversion circuit, and the time for the analog-to-digital conversion circuit to collect the radar wave analog signal is divided into a plurality of continuous sampling time periods according to the clock cycle; Convert the radar wave analog signal of each sampling time period into a corresponding digital sampling value, and use the plurality of sampling time periods and the corresponding digital sampling values ​​as the digital sampling wave; The step of determining a peak value of a digital transmission wave and a peak value of a digital reflection wave in the digital sampling wave comprises: Screening the digital sampling values ​​whose amplitudes in the digital sampling wave are within the threshold range to obtain a sampling area containing a plurality of digital sampling values; Taking 3 consecutive sampling points as a group, traverse the digital sampling values ​​in the sampling area and select 3 consecutive target sampling points; wherein the amplitude of the sampling point located in the middle of the 3 consecutive target sampling points is the largest; Determine the peak value of the digital sampling wave based on the three consecutive target sampling points; The step of determining a peak value of a digital transmission wave and a peak value of a digital reflection wave in the digital sampling wave comprises: Specifically, the amplitude of the middle sampling point among the three consecutive target sampling points is taken as the peak value of the digital sampling wave; Alternatively, a polynomial is used to fit the digital sampling values ​​in the sampling area to obtain a fitting polynomial; a derivative of the fitting polynomial is calculated, and the digital sampling value with a derivative of zero is taken as a potential peak point; and the maximum value of each potential peak point in the digital sampling wave is taken as the peak value of the digital sampling wave; After determining whether the digital sampling wave is within a preset threshold range through the FPGA processing module, the method further includes: When it is determined that the digital sampling wave deviates from a preset threshold range, the gain coefficient of the digitally controlled variable gain amplifier is controlled by the FPGA processing module to adjust the radar pulse wave signal to a radar wave analog signal whose amplitude is within the threshold range; If the digital sampling wave deviates from the preset threshold range, the digital sampling wave is sent to the FPGA processing module without being analyzed and processed, but the next digital sampling wave is received until a digital sampling wave within the threshold range is received; If the peak point of the digital sampling wave obtained after amplification and its two adjacent points are close, or the peak point of the digital sampling wave is greater than the maximum value of the ADC output, it is determined that there is an error in the measured distance and the radar wave analog signal is received again; If the digital sampling waves received multiple times all deviate from the threshold range, the gain coefficient of the digitally controlled variable gain amplifier is controlled by the FPGA processing module to obtain a digital sampling wave with an amplitude within the threshold range, thereby obtaining a valid peak value and achieving accurate ranging.

4. The system according to claim 3, characterized in that The pulse signal preprocessing system further includes a signal conditioning circuit, wherein the signal conditioning circuit is connected between the laser radar module and the analog-to-digital conversion circuit; The signal adjustment circuit is used to receive the radar pulse wave signal output by the laser radar module, adjust the gain of the radar pulse wave signal into a radar wave analog signal, and then send it to the analog-to-digital conversion circuit.

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