Radar signal processing method and agricultural unmanned aerial vehicle

Abstract

The invention provides a radar signal processing method and an agricultural unmanned aerial vehicle, different links of radar signal processing can be configured with special storage spaces, and each processing link can continue to process data of a next stage after completing data processing of a previous stage. The radar signal is not blocked due to the influence of the processing result of the data in the previous stage, and the processing efficiency of the radar signal is high. The size of the special storage space can be adjusted according to the size of data needing to be processed, the utilization efficiency of storage resources of the radar device is high, and the energy utilization efficiency of the agricultural unmanned aerial vehicle using the method is high.

Description

Technical Field

[0001] The present application relates to the technical field of radar signal processing, and in particular, to a radar signal processing method and an agricultural drone. Background Art

[0002] In agricultural production, agricultural drones can be used for sowing, spraying pesticides or fertilizers, and detecting pests and diseases. During these operations, agricultural drones equipped with radar have higher environmental perception capabilities and greater precision operations.

[0003] During operation, agricultural drones need to continuously send, receive, process, and respond to radar signals. Improving the radar signal processing efficiency of agricultural drones is a question worth considering. Summary of the Invention

[0004] The present application provides a radar signal processing method and an agricultural drone. Different radar data can be processed in parallel in different processing links of the radar signal, and the radar signal processing efficiency is higher. The agricultural drone using the signal processing method has high energy utilization efficiency.

[0005] In a first aspect, a method for radar signal processing is provided, which is applied to a radar device. The radar device includes a first processing module, a second processing module, a first storage module, and a second storage module. The first processing module and the second processing module are both used to process radar signals. The method includes: the first processing module processes first data and stores second data in the first storage module, where the second data is the processing result of the first data; the second processing module processes second data and stores third data in the second storage module, where the third data is the processing result of the second data; the first processing module processes fourth data and stores fifth data in the first storage module, where the fifth data is the processing result of the fourth data.

[0006] In a possible implementation, the first processing module is configured to perform a range fast Fourier transform, and the second processing module is configured to perform a Doppler fast Fourier transform.

[0007] In a possible implementation, the first processing module is configured to perform Doppler fast Fourier transform, and the second processing module is configured to perform non-coherent combining.

[0008] In a possible implementation, the first processing module is used to perform incoherent combining, and the second processing module is used to perform constant virtual warning.

[0009] In a possible implementation, the first processing module is used to perform constant false alarm, and the second processing module is used to perform direction of arrival estimation.

[0010] In this technical solution, the first processing module is configured with a dedicated storage space, and the process of the first processing module processing the fourth data will not be affected by the process of the second processing module processing the second data. The first processing module processes data with high efficiency, and the radar device processes radar signals with higher efficiency and lower energy consumption.

[0011] In combination with the first aspect, in some implementations of the first aspect, the first processing module is used to perform range fast Fourier transform processing, and the second processing module is used to perform Doppler fast Fourier transform processing.

[0012] In combination with the first aspect, in certain implementations of the first aspect, the size of the first storage module is determined based on the number of sampling points, the number of transmitting antennas, the number of receiving antennas, and the number of chirp signals; the size of the second storage module is determined based on the number of sampling points, the number of transmitting antennas, the number of receiving antennas, and the number of chirp signals.

[0013] The size of the first storage module and the size of the second storage module can be determined according to data such as the number of sampling points, and the storage resources of the radar device are efficiently utilized.

[0014] In combination with the first aspect, in certain implementations of the first aspect, the radar device further includes a third processing module, a fourth processing module, a fifth processing module, a third storage module, a fourth storage module, and a fifth storage module, the third processing module being used to perform incoherent combination processing, the fourth processing module being used to perform constant virtual warning processing, and the fifth module being used to perform direction of arrival estimation processing. The method further includes: the third processing module processing the third data and storing the sixth data in the third storage module, the sixth data being the processing result of the third data; the fourth processing module processing the sixth data and storing the seventh data in the fourth storage module, the seventh data being the processing result of the sixth data; the fifth processing module processing the seventh data and storing the eighth data in the fifth storage module, the eighth data being the processing result of the seventh data.

[0015] Different links in radar signal processing can be configured with dedicated storage space. The data processing of each processing link for the next stage will not be affected by the data processing results of the previous stage. The radar signal processing efficiency is high and the energy utilization efficiency of the radar device is high.

[0016] In combination with the first aspect, in certain implementations of the first aspect, the size of the third storage module is determined based on the number of sampling points and the number of chirp signals; the size of the fourth storage module is determined based on the number of sampling points; and the size of the fifth storage module is determined based on the maximum number of output targets of the radar signal and the angular accuracy of the radar device.

[0017] The size of the storage space configured in different links of radar signal processing can be configured according to the amount of data to be processed, and the storage resources of the radar device are used efficiently.

[0018] In combination with the first aspect, in certain implementations of the first aspect, before the first processing module processes the first data, the method further includes: determining the number of sampling points based on the working scenario; and determining the first storage module, the second storage module, the third storage module, and the fourth storage module based on the number of sampling points.

[0019] In combination with the first aspect, in certain implementations of the first aspect, the working scene includes a first target scene and a second target scene, the first target scene satisfies one or more of the following: the terrain is flat, the height difference of crops is less than or equal to the height threshold, or the planting density of crops is less than or equal to the density threshold; the second target scene satisfies one or more of the following: the terrain is undulating, the height difference of crops is greater than the height threshold, or the planting density of crops is greater than the density threshold.

[0020] In combination with the first aspect, in some implementations of the first aspect, the first processing module has read permission and write permission for the first storage module, and the second processing module has read permission for the first storage module.

[0021] The radar device can configure storage space of different sizes for different links of radar signal processing according to the actual working scenario, and the storage resources of the radar device are highly utilized.

[0022] In the second aspect, an agricultural drone is provided, comprising a power unit, a radar unit and an operating device, wherein the power unit is used to provide power for the agricultural drone, the operating device is used to perform agricultural operations, and the radar device is used to implement the method in the first aspect and any possible implementation thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is an application scenario of an agricultural drone provided in an embodiment of the present application.

[0024] Figure 2 This is another application scenario of an agricultural drone provided in an embodiment of the present application.

[0025] Figure 3 Schematic diagram of the hardware architecture of a radar device provided in an embodiment of the present application.

[0026] Figure 4 Schematic diagram of a radar signal processing method provided in an embodiment of the present application.

[0027] Figure 5 Schematic diagram of another radar signal processing method provided in an embodiment of the present application.

[0028] Figure 6 This is a schematic diagram of another radar signal processing method provided in an embodiment of the present application.

[0029] Figure 7 This is a schematic diagram of another radar signal processing method provided in an embodiment of the present application.

[0030] Figure 8 Schematic diagram of an agricultural drone provided in an embodiment of the present application. DETAILED DESCRIPTION

[0031] The terms used in the following embodiments are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the specification of this application and the appended claims, the singular expressions "a", "an", "said", "above", "the" and "this" are intended to also include expressions such as "one or more", unless there is a clear contrary indication in the context. It should also be understood that in the following embodiments of the present application, "at least one", "one or more" refer to one, two or more. The term "and / or" is used to describe the association relationship of associated objects, indicating that three relationships can exist; for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and subsequent associated objects are in an "or" relationship.

[0032] References to "one embodiment" or "some embodiments" in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in yet other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0033] The following describes embodiments of the present application in detail, and examples of the embodiments of the present application are shown in the accompanying drawings. In the accompanying drawings, the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present application and are not to be construed as limiting the present application.

[0034] In order to make the technical problems solved by this application, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the embodiments of this application will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments.

[0035] Agricultural drones, also known as agricultural drones, plant protection drones, or plant protection machines, transmit radar signals and receive radar echoes reflected from objects to determine target distance, speed, horizontal and vertical angles, and other information, allowing them to perform corresponding operations. Generally, different operational scenarios require different performance from agricultural drone radar devices, and radar devices with different performance also have different power consumption requirements.

[0036] Figure 1 The figure shows a working scene 10 of the agricultural drone 100. In this working scene 10, the agricultural drone 100 is basically in a parallel flight operation state. In other words, in this working scene 10, the agricultural drone 100 may encounter fewer situations where it is necessary to adjust the flight altitude.

[0037] For example, in work scenario 10, crops may be planted in relatively flat farmland. For example, the heights of the crops in work scenario 10 may be substantially uniform, or the difference in their heights may be less than a height threshold. For example, in work scenario 10, agricultural drone 100 may be in low-altitude flight. For example, in work scenario 10, agricultural drone 100 may be used to spray pesticides on cotton in a plain area.

[0038] In the above-mentioned working scenario 10, the agricultural drone 100 can perform basic obstacle avoidance, roughly adjust the flight altitude, and other operations based on the radar signal. In this scenario, the agricultural drone 100 does not have high requirements for the performance of the radar signal. For example, the agricultural drone 100 does not have high requirements for the altitude measurement accuracy of the radar signal.

[0039] Figure 2 Another working scenario 20 of the agricultural drone 100 is shown. In this working scenario 20 , the agricultural drone 100 needs to frequently adjust its flight altitude to adapt to the working scenario.

[0040] For example, the obstacles in the work scene 20 are relatively dense, or in other words, the agricultural drone 100 in the work scene 20 is located in an obstacle-dense environment. For example, the crops in the work scene 20 may be grown in a mountainous area, basin, or hilly terrain with varying terrain. For example, the heights of the crops in the work scene 20 may vary significantly, or in other words, the height difference between the crops in the work scene 20 may exceed a height threshold. For example, in the work scene 20, the agricultural drone 100 may be used to inspect fruit trees in a hilly area for pests and diseases.

[0041] In operating scenario 20, the agricultural drone 100 may need to accurately and frequently adjust its altitude and flight attitude. This operating scenario 20 places high demands on the radar device. For example, the agricultural drone 100 requires high accuracy in measuring obstacle height and distance, as well as high radar signal processing efficiency.

[0042] Figure 3 FIG2 is a schematic diagram of a hardware architecture of a radar device 200 according to an embodiment of the present application. As shown in the figure, the radar device 200 may include a processing module 210 , a radio frequency front-end module 220 , a power management module 230 , and an internal memory 240 .

[0043] In some examples, the radar device 200 may include multiple RF front-end modules 220, or in other words, the number of RF front-end modules 220 may be multiple, for example, RF front-end module 220-1, RF front-end module 220-2, RF front-end module 220-3, and RF front-end module 220-N (N is an integer greater than or equal to 2). The RF front-end module 220 may include a transmitting antenna, a receiving antenna, a signal generator, a power amplifier, or a low noise amplifier (LNA). Among them, the transmitting antenna can be used to transmit radar signals, and the receiving antenna can be used to receive radar echo signals; the signal generator can be used to generate a transmit signal with a predetermined frequency and modulation characteristics; the power amplifier can be used to amplify the signal generated by the signal generator to a sufficient power level for effective transmission; and the low noise amplifier can be used to preliminarily amplify the received weak signal while maintaining a low noise figure.

[0044] In some examples, processing module 210 can be used to process and analyze signals received by the radar device. For example, processing module 210 can include an analog-to-digital converter (ADC) that can convert analog signals received by radar device 200 into digital signals. For example, processing module 210 can include a digital signal processor (DSP) that can process digital signals, such as performing fast Fourier transform (FFT), Doppler filtering, or target detection on the digital signals.

[0045] Exemplarily, the processing module 210 may further include one or more of a microcontroller unit (MCU), a system on chip (SOC), or a field programmable gate array (FPGA).

[0046] In some examples, power management module 230 can be used to manage and control the power supply of electronic components included in radar apparatus 200, so that each electronic component can obtain a stable, efficient, and reliable power supply. For example, power management module 230 can be used to implement one or more of the following functions: voltage conversion, current regulation, power monitoring, or energy-saving management.

[0047] In some examples, the internal memory 240 can be used to store executable program code used by the processing module 210 during signal or data processing. The executable program code may include instructions. The processing module 210 can process radar signals by executing the instructions stored in the internal memory 240. For example, the internal memory 240 may include high-speed random access memory (RAM) and non-volatile memory (e.g., flash memory).

[0048] In some examples, radar apparatus 200 may further include one or more interfaces 250, which may be used to exchange data between radar apparatus 200 and other devices or equipment. For example, interface 250 may be one or more of a controller area network flexible data-rate (CAN FD) interface, an Ethernet physical layer (ENET PHY) interface, or a quadrature serial peripheral interface (QSPI).

[0049] It should be noted that the above only provides some examples of electronic components or functional modules that the radar device 200 may include. The radar device 200 may also include more or fewer electronic components or functional modules, and this application does not limit this.

[0050] In the process of processing radar echo signals, the signals need to be processed in multiple links, and the processing results of the data in the previous link need to be used in the next link.

[0051] like Figure 4 As shown, during the processing of the radar echo signal, the agricultural drone 100 can perform analog-to-digital conversion, range fast Fourier transform, Doppler fast Fourier transform and other operations on the signal in sequence after receiving the radar echo signal. The specific processing flow is roughly as follows.

[0052] S101, analog-to-digital conversion.

[0053] The RF front-end module 220 of the radar device 200 can receive the radar echo signal and input the radar echo signal to the analog-to-digital converter. The analog-to-digital converter can convert the radar echo signal into a digital signal for subsequent processing.

[0054] S102, range fast Fourier transform (range FFT).

[0055] Typically, the electromagnetic wave signal emitted by radar device 200 is a chirp signal whose frequency increases or decreases linearly over time. When this signal strikes a target and reflects back to radar device 200, the round-trip propagation time causes a frequency difference between the radar echo signal and the currently transmitted signal. This frequency difference is directly related to the target's distance. A range fast Fourier transform (FFT) can be used to separate the distance information of each target from the received mixed signal.

[0056] The range fast Fourier transform (FFT) converts time-domain signals into frequency-domain signals, resulting in radar echo signals at different distances appearing as distinct peaks on the spectrum. Each peak corresponds to a specific distance. By analyzing the FFT results and combining them with parameters such as the radar's operating frequency, the slope of the chirp signal, the sampling rate, and the speed of light, the distance corresponding to each peak can be calculated. The following formula roughly illustrates the relationship between target range and frequency:

[0057]

[0058] Where R represents the distance to the target, c represents the speed of light, f represents the operating frequency of the radar, and k represents the frequency index.

[0059] S103, Doppler fast Fourier transform (Doppler FFT).

[0060] To extract velocity information from a target at a specific distance, the echo information of multiple consecutive chirp signals can be subjected to Doppler fast Fourier transform processing. For example, by accumulating data from all chirp signal echo signals within the same distance range and performing fast Fourier transform on the accumulated data.

[0061] Due to the relative motion between the target and the radar device 200, this relative motion will produce additional frequency offset within a specific distance range. The result of the Doppler Fast Fourier Transform is a frequency-Doppler spectrum, and the peak position on the spectrum can reflect the speed of the target.

[0062] S104, non-coherent combining (NCC).

[0063] Also known as incoherent combining, it is used to integrate the signal energy of different channels in the radar signal processing process to improve the signal-to-noise ratio of target detection.

[0064] Typically, during the incoherent combining process, the amplitudes of signals from different receiving paths (e.g., antennas) can be processed. Specifically, a modulo operation can be performed on the complex signal of each receiving channel to convert it into signal amplitude information. By summing the amplitude information of all channels and averaging the accumulated amplitude signals, the signal energy after noise suppression can be obtained.

[0065] S105, constant false alarm.

[0066] Constant false alarm rate (CFAR) is used to detect objects in a noisy background. By dynamically adjusting the detection threshold, the false alarm rate remains constant under different environmental conditions.

[0067] S106, direction of arrival (DOA) estimation.

[0068] Direction of arrival (DOA) estimation is used to determine the target's angle information based on the radar echo signal, which can include the horizontal angle (azimuth) and the vertical angle (pitch angle).

[0069] Exemplarily, the direction of arrival estimation can be performed by one or more of the following algorithms: fast Fourier transform and delay-and-sum beamforming (DBF), multiple signal classification (MUSIC) and estimation of signal parameters via rotational invariance techniques (ESPRIT), orthogonal matching pursuit (OMP) or reduced-dimension atomic norm minimization (RD-ANM) algorithm, etc.

[0070] In the above data processing process, a feasible way is to store the processing results of the data of the first link in the internal memory, read the corresponding data from the internal memory at the beginning of the second link, and after completing the data processing operation of the second link, store the processing results of the data of the second link in the internal memory, read the corresponding data from the internal memory at the beginning of the third link, and so on, until the data processing of all links is completed and the data processing results are output.

[0071] In order to improve the processing efficiency of radar data, so that the agricultural UAV can respond in time according to the processing results of the radar data, the embodiment of the present application provides the following Figure 5 The radar signal processing method shown in FIG. Radar device 200 can allocate dedicated memory space for different steps in the radar data processing process. Processing modules in different steps can continue processing the next batch of data after completing one batch of data, without having to wait for the previous batch of data to complete all steps. This improves radar data processing efficiency.

[0072] S201 - 1 , the processing module 1 performs a first process on the data D1 to generate data 11 .

[0073] In some examples, processing module 1 can be used to perform a distance fast Fourier transform on radar data. In this case, the first processing can be a distance fast Fourier transform, data D1 can be data obtained after analog-to-digital conversion of the radar echo signal, and data 11 can be the result of performing a distance fast Fourier transform on the data D1.

[0074] In some examples, processing module 1 can be used to perform Doppler fast Fourier transform on radar data. In this case, the first processing can be Doppler fast Fourier transform, data D1 can be data obtained by performing range fast Fourier transform on radar data, and data 11 can be the result of performing Doppler fast Fourier transform on data D1.

[0075] In some examples, processing module 1 can be used to perform incoherent combination processing on radar data. In this case, the first processing can be incoherent combination processing, data D1 can be data obtained after Doppler fast Fourier transform, and data 11 can be the result of incoherent combination processing of data D1.

[0076] In some examples, processing module 1 can be used to perform constant virtual warning processing on radar data. In this case, the first processing can be constant virtual warning processing, data D1 can be data obtained by incoherent combination processing, and data 11 can be the result of constant virtual warning processing on data D1.

[0077] After completing the first processing on the data D1, the processing module 1 may store the processing result (data 11) in the storage module 1. In some scenarios, the processing module 1 may have read permission and write permission on the data space of the storage module 1.

[0078] S202 - 1 , the processing module 2 performs a second process on the data 11 to generate data 12 .

[0079] In some scenarios, the processing module 2 may have read permission on the data space of the storage module 2. The processing module 2 may read the data 11 from the storage module 1 and process the data 11.

[0080] In some examples, processing module 2 can be used to perform a Doppler fast Fourier transform on radar data. In this case, the second processing can be a Doppler fast Fourier transform, data 11 can be data obtained after performing a range fast Fourier transform on the radar data, and data 12 can be the result of performing a Doppler fast Fourier transform on data 11.

[0081] In some examples, processing module 2 can be used to perform incoherent combination processing on radar data. In this case, the second processing can be incoherent combination processing, data 11 can be data obtained after Doppler fast Fourier transform, and data 12 can be the result of incoherent combination processing on data 11.

[0082] In some examples, the processing module 2 can be used to perform constant virtual warning processing on radar data. In this case, the first processing can be constant virtual warning processing, data 11 can be data obtained by incoherent combination processing, and data 12 can be the result of constant virtual warning processing on data 11.

[0083] In some examples, processing module 2 can be used to estimate the direction of arrival of radar data. In this case, the second processing can be the direction of arrival estimation, data 11 can be the data obtained by constant false alarm processing of the radar echo signal, and data 12 can be the result of the direction of arrival estimation of data 11.

[0084] After completing the processing of the data 11, the processing module 2 may store the result of the data processing (data 12) in the storage module 2. In other words, the processing module 2 may have write permission and read permission to the storage module 2.

[0085] S201 - 2 , the processing module 1 performs a first process on the data D2 to generate data 21 .

[0086] After completing the first processing of data D1, processing module 1 can continue to process data D2. After processing module 2 reads data 11 from storage module 1, processing module 1 can store the result of the first processing of data D2 (data 21) in the storage space of storage module 1 for processing by processing module 2.

[0087] After completing the processing of the data 11 , the processing module 2 may read the data 12 from the storage module 1 and perform a second process.

[0088] Compared with the solution in which processing module 1 and processing module 2 share the same storage module (or storage space), in this technical solution, processing module 1 is configured with a dedicated storage module, and the first processing and the second processing can be decoupled. In other words, the process of processing module 2 processing data 11 will not block the processing module 1 processing data D2. The implementation of this technical solution is conducive to improving the processing efficiency of radar device 200 for radar signals.

[0089] Figure 6 The figure shows another radar signal processing method provided by an embodiment of the present application. Dedicated storage space is configured in each link of radar signal processing. In the data processing flow, the subsequent processing link will not cause obstruction to the previous processing link, and the radar signal processing efficiency is high.

[0090] Take the processing flow of sample data A as an example:

[0091] S301 - 1 , processing module A performs a first process on sampled data A to generate data A1 .

[0092] Here, the processing module A can be used to perform a range fast Fourier transform on the sampled data A. The first processing can be regarded as a range fast Fourier transform, and the data A1 can be regarded as a processing result of the range fast Fourier transform.

[0093] The processing module A corresponds to the storage module A, or in other words, the first processing corresponds to the storage module A. The result (data A1) of the first processing of the sample data A by the processing module A can be stored in the storage module A.

[0094] In some examples, processing module A has write permission and read permission on the storage space of storage module A.

[0095] In some examples, after completing the first processing of sampled data A, processing module A may continue to perform the first processing on sampled data B and generate data B1. When processing module B reads data A1 from storage module A, data B1 may be stored in storage module A for reading by processing module B.

[0096] Similarly, after completing the first processing of sampled data B, processing module A can continue to perform the first processing on sampled data C and generate data C1. When processing module B reads data B1 from storage module A, data C1 can be stored in storage module A for processing module B to read.

[0097] In order to improve the utilization efficiency of the storage resources of the radar device, in some examples, the size of the storage space of the storage module A can be determined according to the amount of sampled data. For example, the storage space Ma of the storage module A can be calculated according to the following formula:

[0098] Ma=2×S×N Tx ×N Rx ×N chirp (1)

[0099] Among them, S represents the number of sampling points, N Tx Indicates the number of transmitting antennas of the radar device, N Rx Indicates the number of receiving antennas of the radar device, N chirp Indicates the number of chirp signals or the number of complete transmit and receive cycles.

[0100] S302-1, processing module B performs a second process on data A1 to generate data A2.

[0101] The processing module B can read the data A1 from the storage module A and perform a second process on the data A1.

[0102] Here, the processing module B can be used to perform Doppler fast Fourier transform on the data A1, the second processing can be regarded as Doppler fast Fourier transform, and the data A2 can be regarded as the processing result of the Doppler fast Fourier transform.

[0103] The processing module B corresponds to the storage module B, or in other words, the second processing corresponds to the storage module B. The result (data A2) of the second processing performed by the processing module B on the data A1 can be stored in the storage module B.

[0104] In some examples, processing module B has write permission and read permission on the storage space of storage module B.

[0105] In some examples, processing module B has read permission on the storage space of storage module A.

[0106] In some examples, after completing the second processing on data A1, processing module B may continue to perform the second processing on data B1 and generate data B2. When processing module C reads data A2 from storage module B, data B2 may be stored in storage module B for processing module C to read.

[0107] Similarly, after completing the second processing on data B1, processing module B can continue to perform the second processing on data C1 and generate data C2. When processing module C reads data B2 from storage module B, data C2 can be stored in storage module B for processing module C to read.

[0108] In order to improve the utilization efficiency of the storage resources of the radar device, in some examples, the size of the storage space of the storage module B can be determined according to the amount of sampled data. For example, the storage space Mb of the storage module B can be calculated according to the following formula:

[0109] Mb=2×S×N Tx ×N Rx ×N chirp (2)

[0110] Among them, S represents the number of sampling points, N Tx Indicates the number of transmitting antennas of the radar device, N Rx Indicates the number of receiving antennas of the radar device, N chirp Indicates the number of chirp signals or the number of complete transmit and receive cycles.

[0111] S303-1, processing module C performs a third process on data A2 to generate data A3.

[0112] The processing module C can read the data A2 from the storage module B and perform a third process on the data A2.

[0113] Here, the processing module C can be used to perform incoherent combination on the data A2, the third process can be regarded as the incoherent combination process, and the data A3 can be regarded as the result of the incoherent combination process.

[0114] The processing module C corresponds to the storage module C, or in other words, the third processing corresponds to the storage module C. The result (data A3) of the third processing performed by the processing module C on the data A2 can be stored in the storage module C.

[0115] In some examples, processing module C has write permission and read permission on the storage space of storage module C.

[0116] In some examples, processing module C has read permission on the storage space of storage module B.

[0117] In some examples, after completing the third processing on data A2, processing module C may continue to perform the third processing on data B2 and generate data B3. When processing module D reads data A3 from storage module C, data B3 may be stored in storage module C for reading by processing module D.

[0118] Similarly, after completing the third processing on data B2, processing module C can continue to perform the third processing on data C2 and generate data C3. When processing module D reads data B3 from storage module C, data C3 can be stored in storage module C for processing module D to read.

[0119] In order to improve the utilization efficiency of the storage resources of the radar device, in some examples, the size of the storage space of the storage module C can be determined according to the amount of sampled data. For example, the storage space Mc of the storage module C can be calculated according to the following formula:

[0120] Mc=2×S×N chirp (3)

[0121] Among them, S represents the number of sampling points, N chirp Indicates the number of chirp signals or the number of complete transmit and receive cycles.

[0122] S304-1, processing module D performs fourth processing on data A3 to generate data A4.

[0123] The processing module D may read the data A3 from the storage module C and perform the fourth processing on the data A3.

[0124] Here, the processing module D can be used to perform constant virtual warning processing on the data A3, the fourth processing can be regarded as the constant virtual warning processing, and the data A4 can be regarded as the processing result of the constant virtual warning.

[0125] The processing module D corresponds to the storage module D, or in other words, the fourth process corresponds to the storage module D. The result (data A4) of the fourth process performed by the processing module D on the data A3 can be stored in the storage module D.

[0126] In some examples, processing module D has write permission and read permission on the storage space of storage module D.

[0127] In some examples, processing module D has read permission on the storage space of storage module C.

[0128] In some examples, after completing the fourth processing on data A3, processing module D may continue to perform the fourth processing on data B3 and generate data B4. When processing module E reads data A4 from storage module D, data B4 may be stored in storage module D for processing module E to read.

[0129] Similarly, after completing the fourth processing on data B3, processing module D can continue to perform the fourth processing on data C3 and generate data C4. When processing module E reads data B4 from storage module D, data C4 can be stored in storage module D for processing module E to read.

[0130] In order to improve the utilization efficiency of the storage resources of the radar device, in some examples, the size of the storage space of the storage module D can be determined according to the amount of sampled data. For example, the storage space Md of the storage module D can be calculated according to the following formula:

[0131] Md=2×S (4)

[0132] Where S represents the number of sampling points.

[0133] S305-1, processing module E performs fifth processing on data A4 to generate data A5.

[0134] The processing module E may read the data A4 from the storage module D and perform a fifth process on the data A4.

[0135] Here, the processing module E can be used to perform direction of arrival estimation on the data A4, the fifth process can be regarded as a direction of arrival estimation process, and the data A5 can be regarded as a result of the direction of arrival estimation process.

[0136] The processing module E corresponds to the storage module E, or in other words, the fifth process corresponds to the storage module E. The result (data A5) of the fifth process performed by the processing module E on the data A4 can be stored in the storage module E.

[0137] In some examples, the processing module E has write permission and read permission on the storage space of the storage module E.

[0138] In some examples, processing module E has read permission on the storage space of storage module D.

[0139] In some scenarios, the result of the fifth processing of the data A4 by the processing module E (data A5) can be regarded as the processing result of the sampled data A. For example, the data A5 can also be referred to as result data A.

[0140] In order to improve the utilization efficiency of the storage resources of the radar device, in some examples, the size of the storage space of the storage module E can be determined according to the amount of sampled data. For example, the storage space Me of the storage module E can be calculated according to the following formula:

[0141] Me=N target ×4×N rs (5)

[0142] Among them, N target Indicates the maximum number of output targets, N rs Indicates the number of beams corresponding to the field of view of the radar device. For the calculation of the horizontal angle, N rs It can refer to the number of beams that can be formed by the radar device's field of view in the horizontal direction; for the calculation of the vertical angle, N rs It may refer to the number of beams that can be formed in the vertical direction by the field of view of the radar device. In some examples, the number of beams is related to the field of view of the radar device and the angular accuracy of the radar device.

[0143] In the above data processing process, after completing the first processing of sampled data A, processing module A can continue processing sampled data B without waiting for sampled data A to complete the second through fifth processing steps to generate result data A. This makes processing module A's first processing more efficient. Similarly, after completing the second processing of data A1, processing module B can continue processing data B1 without waiting for data A1 to complete the third through fifth processing steps to generate result data A. This makes processing module B's second processing more efficient. After completing the third processing of data A2, processing module C can continue processing data B2 without waiting for data A2 to complete the fourth and fifth processing steps to generate result data A. This makes processing module C's third processing more efficient. After completing the fourth processing of data A3, processing module D can continue processing data B3 without waiting for data A3 to complete the fifth processing step to generate result data A. This makes processing module D's fourth processing more efficient. Overall, the above method improves the efficiency of radar data processing.

[0144] For example, the time length for processing module A to process a frame of data may be t1, the time length for processing module B to process a frame of data may be t2, the time length for processing module C to process a frame of data may be t3, the time length for processing module D to process a frame of data may be t4, and the time length for processing module E to process a frame of data may be t5. The maximum value among t1, t2, t3, t4 and t5 may be tm. In the case of serial processing by the aforementioned five processing modules, the processing time required from sampling data to result data is ts (ts=t1+t2+t3+t4+t5). In the case of a large amount of data, in the case of parallel processing, the processing time of each frame of data can be roughly represented by tm, and in the case of serial processing, the processing time of each frame of data can be roughly represented by ts. Since ts>tm, the processing time required from sampling data to result data is ts (ts=t1+t2+t3+t4+t5). Figure 6 The radar signal processing method shown can improve the radar signal processing efficiency of the radar device.

[0145] In order to improve the utilization efficiency of storage resources in the radar device, different sizes of storage space can be configured for different processing links of radar data. In scenarios where high radar performance requirements are required, larger storage space can be configured for different processing links of radar data. In scenarios where low radar performance requirements are required, smaller storage space can be configured for different processing links of radar data. Based on this principle, the embodiment of the present application provides the following: Figure 7 The radar data processing method shown can be used for agricultural UAVs.

[0146] S401, determine the number of sampling points according to the working scenario.

[0147] In some examples, the agricultural drone may include a radar device, through which the agricultural drone may send out a transmission signal and receive a radar echo signal, and the working scene may be determined based on the processing result of the radar echo signal.

[0148] For example, the agricultural drone can identify the terrain of the working scene based on the received radar echo data, such as the ups and downs of the field, the location of obstacles, etc. One possible situation is that the agricultural drone determines that the terrain in the working scene is relatively flat based on the radar echo data. For example, the working scene can be Figure 1 One possible scenario is that the agricultural drone determines based on radar echo data that the terrain in the working scene has large changes, for example, the working scene can be Figure 2 The scene shown.

[0149] For example, the agricultural drone can determine the height and / or density of crops based on received radar echo data. One possible scenario is that the agricultural drone determines, based on the radar echo data, that the heights of crops in the working scene are substantially uniform and / or that the density (or planting density) of crops is relatively sparse. Alternatively, the agricultural drone determines, based on the radar echo data, that the difference in the heights of crops in the working scene is less than or equal to a height threshold and / or that the density of crops is less than or equal to a density threshold. Another possible scenario is that the agricultural drone determines, based on the radar echo data, that the heights of crops in the working scene vary significantly and / or that the density of crops is relatively dense. Alternatively, the agricultural drone determines, based on the radar echo data, that the difference in the heights of crops in the working scene is greater than a height threshold and / or that the density of crops is greater than a density threshold.

[0150] In some examples, the agricultural drone may include a visual sensor such as a camera. The agricultural drone may obtain image information of the working scene through the visual sensor and determine the working scene based on the image information.

[0151] For example, an agricultural drone uses an image sensor to capture high-resolution images of a work scene. Based on these images, the coverage of crops or the planting density of crops in the work scene can be determined. One possible scenario is that the planting density of crops in the work scene is relatively sparse. Another possible scenario is that the planting density of crops in the work scene is relatively dense.

[0152] For example, an agricultural drone uses an image sensor to capture high-resolution images of a work scene, and based on these images, it can determine the pest and disease status of crops in the work scene. One possible scenario is that the pest and disease status of crops in the work scene is severe, for example, crops with pests and diseases are widely distributed, or pests and diseases are found in multiple locations on a single crop. Another possible scenario is that the pest and disease status of crops in the work scene is mild, for example, crops with pests and diseases are concentrated, or pests and diseases are found in a small number of locations on a single crop.

[0153] In some examples, the working scene may include a first target scene and a second target scene, wherein the first target scene may meet one or more of the following: the terrain is relatively flat, the height of crops is basically consistent, the planting density of crops is relatively sparse, or the crop diseases and insect pests are relatively mild; the second target scene may meet one or more of the following: the terrain is relatively undulating, the height of crops is relatively different, the planting density of crops is relatively dense, or the crop diseases and insect pests are relatively serious.

[0154] In some examples, in the aforementioned first target scenario, the radar device of the agricultural drone may use a higher number of sampling points, and in the aforementioned second target scenario, the radar device of the agricultural drone may use a lower number of sampling points.

[0155] For example, in the first target scenario, the number of sampling points of the radar device of the agricultural drone is S1, and in the second target scenario, the number of sampling points of the radar device of the agricultural drone is S2, and S2 is greater than S1.

[0156] S402: Determine a first storage space, a second storage space, a third storage space, and a fourth storage space according to the number of sampling points.

[0157] Here, the first storage space can be the space used by the radar device to store the processing results of the range fast Fourier transform, the second storage space can be the space used by the radar device to store the processing results of the Doppler fast Fourier transform, the third storage space can be the space used by the radar device to store the processing results of the incoherent combination, and the fourth storage space can be the space used by the radar device to store the processing results of the constant virtual warning.

[0158] In some examples, the sizes of the first storage space, the second storage space, the third storage space, and the fourth storage space can be calculated respectively according to the aforementioned formulas (1) to (4).

[0159] S403: Process the radar echo data of the target scene.

[0160] The agricultural drone can process the received radar echo data according to the methods in S301-1 to S305-1 in the aforementioned example, and perform operations based on the data processing results.

[0161] Based on similar principles, such as Figure 8 As shown, an embodiment of the present application further provides an agricultural drone 800 , which may include a power device 810 , a control device 820 , an operating device 830 and a detection device 840 .

[0162] In some examples, the power unit 810 can be used to provide power for the flight, operation, etc. of the agricultural drone 800. For example, the power unit 810 can include a motor, a propeller, a battery, etc.

[0163] In some examples, the control device 820 can be used to control the flight attitude and navigation of the agricultural drone 800. For example, the control device 820 can include a communication module, a positioning module, an inertial measurement unit, and various sensors such as a barometer and a magnetometer.

[0164] In some examples, the operating device 830 can be used for the operation of the agricultural drone 800. For example, the operating device 830 can be used to spray pesticides, fertilizers, etc. For example, the operating device 830 can include a medicine box, a spray head, a flow control valve, and a spraying pipeline.

[0165] In some examples, the detection device 840 can be used for environmental perception and operation control of the agricultural drone 800. For example, the detection device 840 can include the radar device 200 described above. The detection device 840 can also include visual sensors such as cameras, spectral sensors, or humidity sensors.

[0166] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0167] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0168] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, 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.

[0169] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0170] 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.

[0171] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a 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 various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0172] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A method for radar signal processing, characterized in that: Applied to a radar device, the radar device includes a first processing module, a second processing module, a first storage module and a second storage module, the first processing module and the second processing module are both used to process radar signals, and the method includes: The first processing module processes the first data and stores second data in the first storage module, where the second data is a processing result of the first data; The second processing module processes the second data and stores third data in the second storage module, wherein the third data is a processing result of the second data; The first processing module processes the fourth data and stores the fifth data in the first storage module, wherein the fifth data is the processing result of the fourth data.

2. The method according to claim 1, characterized in that: The first processing module is used to perform range fast Fourier transform processing, and the second processing module is used to perform Doppler fast Fourier transform processing.

3. The method according to claim 1 or 2, characterized in that: The size of the first storage module is determined according to the number of sampling points, the number of transmitting antennas, the number of receiving antennas and the number of chirp signals; The size of the second storage module is determined according to the number of sampling points, the number of transmitting antennas, the number of receiving antennas and the number of chirp signals.

4. The method according to claim 2 or 3, characterized in that: The radar device further includes a third processing module, a fourth processing module, a fifth processing module, a third storage module, a fourth storage module and a fifth storage module, wherein the third processing module is used to perform incoherent combination processing, the fourth processing module is used to perform constant virtual warning processing, and the fifth processing module is used to perform direction of arrival estimation processing. The method further includes: The third processing module processes the third data and stores sixth data in the third storage module, wherein the sixth data is a processing result of the third data; The fourth processing module processes the sixth data and stores seventh data in the fourth storage module, wherein the seventh data is a processing result of the sixth data; The fifth processing module processes the seventh data and stores the eighth data in the fifth storage module, wherein the eighth data is the processing result of the seventh data.

5. The method according to claim 4, characterized in that The size of the third storage module is determined according to the number of sampling points and the number of chirp signals; The size of the fourth storage module is determined according to the number of sampling points; The size of the fifth storage module is determined according to the maximum output target number of the radar signal and the angular accuracy of the radar device.

6. The method according to claim 5, characterized in that Before the first processing module processes the first data, the method further includes: Determine the number of sampling points based on the work scenario; The first storage module, the second storage module, the third storage module and the fourth storage module are determined according to the number of sampling points.

7. The method according to claim 6, characterized in that The working scene includes a first target scene and a second target scene. The first target scene satisfies one or more of the following: the terrain is flat, the height difference of the crops is less than or equal to the height threshold, or the planting density of the crops is less than or equal to the density threshold; The second target scene satisfies one or more of the following: the terrain is undulating, the height difference of the crops is greater than a height threshold, or the planting density of the crops is greater than the density threshold.

8. The method according to any one of claims 1 to 7, characterized in that The first processing module has a read permission and a write permission on the first storage module, and the second processing module has a read permission on the first storage module.

9. An agricultural drone, characterized in that: It comprises a power device, a radar device and an operating device, wherein the power device is used to provide power for the agricultural UAV, the operating device is used to perform agricultural operations, and the radar device is used to execute the method according to any one of claims 1 to 8.

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