Aircraft detection circuit, detection device and detection method

Abstract

The embodiment of the invention discloses an aircraft detection circuit, detection equipment and a detection method, and belongs to the technical field of aircraft detection. The aircraft detection circuit comprises an antenna, a signal demodulation module and a signal processing module. The antenna is used for receiving a radio signal and converting the radio signal into a radio frequency signal; the signal demodulation module is connected with the antenna and is used for demodulating the radio frequency signal to obtain a demodulated signal; the signal processing module is connected with the signal demodulation module, and is used for extracting a line synchronization signal from the demodulation signal, and obtaining a detection result of the aircraft based on the line synchronization signal. The aircraft is detected by detecting the line synchronization signal, and the detection speed of the aircraft can be effectively improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of aircraft detection technology, and in particular to an aircraft detection circuit, a detection device, and a detection method. Background Art

[0002] Some existing aircraft transmit video signals to a control terminal, such as FPV (First Person View) drones, which transmit video signals captured by their cameras to the operator's terminal. To ensure aviation and public safety, it is necessary to demarcate airspace for aircraft, clearly defining controlled airspace and suitable airspace, and to regulate aircraft within controlled airspace.

[0003] To monitor and control aircraft, it is necessary to detect aircraft within a specific area to determine if any aircraft are present. However, if the detection speed is too slow, it will be difficult to detect an aircraft at high speeds. Therefore, a solution to improve the detection speed is urgently needed. Summary of the Invention

[0004] The embodiments of the present application provide an aircraft detection circuit, a detection device, and a detection method, which effectively improve the detection speed of an aircraft.

[0005] An embodiment of the present application provides an aircraft detection circuit, comprising: an antenna, a signal demodulation module, and a signal processing module;

[0006] The antenna is used to receive radio signals and convert the radio signals into radio frequency signals;

[0007] The signal demodulation module is connected to the antenna and is used to demodulate the radio frequency signal to obtain a demodulated signal;

[0008] The signal processing module is connected to the signal demodulation module, and is used to extract a row synchronization signal from the demodulated signal, and obtain a detection result of the aircraft based on the row synchronization signal.

[0009] Furthermore, the signal processing module includes: a horizontal synchronization signal extraction module and a controller;

[0010] The row synchronization signal extraction module is connected to the signal mediation module and is used to extract the row synchronization signal from the demodulated signal;

[0011] The controller is connected to the line synchronization signal extraction module and is used to obtain the detection result of the aircraft based on the line synchronization signal.

[0012] Furthermore, the horizontal synchronization signal extraction module includes: a bandpass filtering unit;

[0013] The input end of the bandpass filtering unit is connected to the signal demodulation module, and the output end of the bandpass filtering unit is connected to the controller; wherein the center frequency of the bandpass filtering unit is the frequency of the line synchronization signal or the average value of the frequencies of multiple line synchronization signals.

[0014] Furthermore, the horizontal synchronization signal extraction module further includes: a first DC isolation unit and a second DC isolation unit;

[0015] The first DC isolation unit is connected between the output end of the signal demodulation module and the input end of the bandpass filtering unit;

[0016] The second DC isolation unit is connected between the output end of the bandpass filtering unit and the controller.

[0017] Furthermore, the horizontal synchronization signal extraction module further includes: an operational amplifier unit;

[0018] The input end of the operational amplifier unit is connected to the output end of the band-pass filter unit, and the output end of the operational amplifier unit is connected to the controller;

[0019] The operational amplifier unit is used to amplify the horizontal synchronization signal.

[0020] Furthermore, the horizontal synchronization signal extraction module further includes: an envelope detection unit;

[0021] The input end of the envelope detection unit is connected to the output end of the bandpass filtering unit, and the output end of the envelope detection unit is connected to the controller;

[0022] The envelope detection unit is used to extract the envelope electrical signal of the horizontal synchronization signal;

[0023] The controller is used to obtain a detection result of the aircraft based on a comparison result of the envelope electrical signal and a preset amplitude threshold.

[0024] Furthermore, the signal demodulation module includes: a signal preprocessing unit and a demodulation unit;

[0025] The signal preprocessing unit is connected to the antenna and is used to preprocess the radio frequency signal;

[0026] The input end of the demodulation unit is connected to the signal preprocessing unit, and the output end of the demodulation unit is connected to the signal processing module; the demodulation unit is used to demodulate the preprocessed RF signal to obtain a demodulated signal.

[0027] An embodiment of the present application further provides an aircraft detection device, comprising the above-mentioned aircraft detection circuit.

[0028] The present application also provides an aircraft detection method, which is applied to an aircraft detection device, including:

[0029] receiving a radio signal and converting the radio signal into a radio frequency signal;

[0030] Demodulating the radio frequency signal based on the signal transmission mode of the aircraft radio signal to obtain a demodulated signal;

[0031] A row synchronization signal is extracted from the demodulated signal, and a detection result of the aircraft is obtained based on the row synchronization signal.

[0032] The present application also provides an aircraft detection method, including:

[0033] Acquire an envelope electrical signal corresponding to a horizontal synchronization signal; the horizontal synchronization signal is obtained from a received radio signal;

[0034] Based on the comparison result of the envelope electrical signal and the preset amplitude threshold, the detection result of the aircraft is obtained.

[0035] It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

[0036] In an embodiment of the present application, an aircraft detection circuit includes an antenna, a signal demodulation module, and a signal processing module. The antenna is configured to receive radio signals and convert them into radio frequency signals. The signal demodulation module, connected to the antenna, demodulates the radio frequency signals to generate demodulated signals. The signal processing module, connected to the signal demodulation module, extracts a line synchronization signal from the demodulated signals and uses the line synchronization signal to determine aircraft detection results.

[0037] As can be seen, in the embodiments of the present application, the signal demodulation module and the signal processing module can extract the horizontal synchronization signal transmitted by the aircraft from the radio signal. Because the horizontal synchronization signal has a high frequency, detecting the horizontal synchronization signal in the radio signal to detect the aircraft can effectively improve the detection speed of the aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0039] Figure 1 A circuit block diagram of an aircraft detection circuit disclosed in an embodiment of the present application;

[0040] Figure 2 A circuit block diagram of another aircraft detection circuit disclosed in an embodiment of the present application;

[0041] Figure 3 This is a circuit block diagram of the first signal processing module disclosed in an embodiment of the present application;

[0042] Figure 4 This is a circuit block diagram of the second signal processing module disclosed in an embodiment of the present application;

[0043] Figure 5 This is a circuit block diagram of the third signal processing module disclosed in the embodiment of this application;

[0044] Figure 6 This is a circuit block diagram of the fourth signal processing module disclosed in an embodiment of the present application;

[0045] Figure 7 A circuit block diagram of a signal demodulation module disclosed in an embodiment of the present application;

[0046] Figure 8 A circuit diagram of a horizontal synchronization signal extraction module disclosed in an embodiment of the present application;

[0047] Figure 9 A schematic diagram of a demodulated signal and a horizontal synchronization signal disclosed in an embodiment of the present application;

[0048] Figure 10 This is an enlarged waveform diagram of the horizontal synchronization signal disclosed in the embodiment of the present application;

[0049] Figure 11 A waveform diagram of an envelope electrical signal disclosed in an embodiment of the present application;

[0050] Figure 12 A circuit diagram of a signal demodulation module disclosed in an embodiment of the present application;

[0051] Figure 13 A flowchart of an aircraft detection method disclosed in an embodiment of the present application;

[0052] Figure 14 This is a flowchart of another aircraft detection method disclosed in an embodiment of the present application.

[0053] In the figure: 100, antenna; 200, signal demodulation module; 201, signal preprocessing unit; 2011, filtering unit; 2012, amplification unit; 202, demodulation unit; 300, signal processing module; 301, horizontal synchronization signal module; 3011, bandpass filtering unit; 3011-1, first second-order active bandpass filter; 3011-2, second second-order bandpass active filter; 3012, first DC isolation unit; 3013, operational amplifier unit; 3014, envelope detection unit; 3015, second DC isolation unit; 302, controller. DETAILED DESCRIPTION

[0054] In order to help those skilled in the art better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0055] In the description of the embodiments of the present application, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limiting the embodiments of the present application.

[0056] In the description of the embodiments of the present application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present application based on the specific circumstances.

[0057] In order to monitor and control aircraft, it is necessary to detect aircraft in the relevant area to determine whether there are aircraft in the relevant area. However, when the aircraft is flying at a high speed, if the detection speed of the aircraft is too slow, it will not be of practical significance. Therefore, the embodiment of the present application provides an aircraft detection circuit that can effectively improve the speed of aircraft detection, such as Figure 1 As shown, the details are as follows.

[0058] In the embodiment of the present application, an aircraft detection circuit includes an antenna 100, a signal demodulation module 200, and a signal processing module 300. The aircraft detection circuit can detect an aircraft. The aircraft can be an FPV drone (also known as a FPV drone), etc., although this is not specifically limited here.

[0059] Antenna 100 is configured to receive radio signals and convert them into radio frequency signals. It is understood that antenna 100 can scan for radio signals in the air in real time. The radio signals can be within a preset frequency band. The preset frequency band can be set based on a signal frequency band commonly used by the aircraft.

[0060] The signal demodulation module 200 is connected to the antenna 100 and is configured to demodulate the radio frequency signal to generate a demodulated signal. If the radio signal received by the antenna 100 contains an aircraft radio signal, the signal demodulation module 200 can demodulate the signal to generate a demodulated signal. If the signal does not contain an aircraft radio signal, the demodulation result of the radio frequency signal is a blank electrical signal.

[0061] The signal demodulation module 200 can perform demodulation based on commonly used protocols for commercially available aircraft. For example, if multiple protocols are used, the signal demodulation module 200 sequentially demodulates the received RF signal using the demodulation methods of different protocols. The protocol that successfully demodulates represents the protocol used by the aircraft. For example, the aircraft is an FPV drone. FPV drones typically use a television format for video transmission during flight. The signal demodulation module 200 can demodulate for television formats commonly used by aircraft. These television formats include Phase Alternating Line (PAL), National Television System Committee (NTSC), and Sequential Couleur avec Memoire (SECAM NTSC). Specifically, the PAL format can be further divided into PAL-D, PAL-N, and PAL-M. Since the PAL, NTSC, and SECAM NTSC standards all use the same demodulation method for horizontal synchronization signals, the signal demodulation module 200 can demodulate radio signals of the three standards, namely, PAL, NTSC, and SECAM NTSC, using the same demodulation method. The specific demodulation method of the signal demodulation module 200 can refer to the demodulation principles of the PAL, NTSC, and SECAM NTSC standards, and will not be further described here.

[0062] When antenna 100 receives a radio signal from an aircraft, the demodulated signal obtained through demodulation processing includes the aircraft's video signal. For example, for an FPV drone using the PAL format for broadcast video transmission, the demodulated signal obtained by signal demodulation module 200 through PAL demodulation is a composite video broadcast signal (CVBS). Antenna 100 and signal demodulation module 200 can accurately demodulate the aircraft's demodulated signal (such as the FPV drone's video signal) from the radio signal in the air, preventing false alarms in the detection circuit.

[0063] The signal processing module 300, connected to the signal demodulation module 200, is configured to extract the line synchronization signal from the demodulated signal and derive aircraft detection results based on the line synchronization signal. Specifically, when the radio signal received by the antenna 100 contains an aircraft radio signal, the signal processing module 300 can extract the aircraft's line synchronization signal from the demodulated signal. The signal processing module 300 can derive aircraft detection results based on the line synchronization signal. For example, if the line synchronization signal is present, the aircraft is determined to be present. If the line synchronization signal is absent, the aircraft is determined to be absent. It is understood that the video signal transmitted by the aircraft includes medium- and low-frequency signals (line synchronization and field synchronization) and high-frequency signals (color difference signals, luminance signals, etc.). The line synchronization signal has a higher frequency than other low-frequency signals (field synchronization), meaning it appears more frequently in the video signal, enabling faster aircraft detection. Therefore, the signal processing module 300 of this solution, by extracting the line synchronization signal for aircraft detection, can effectively improve aircraft detection speed. The signal processing module 300 can be implemented entirely by software (for example, the signal processing module 300 can be directly a processor), or it can be implemented by a combination of software and hardware. For example, a hardware circuit first extracts the horizontal synchronization signal through filtering or other methods, and then the processor determines whether the signal extracted by the hardware circuit is a horizontal synchronization signal based on the characteristics of horizontal synchronization signals known in the industry to obtain a detection result. All of these are within the scope of protection of this application.

[0064] As can be seen, in the embodiments of the present application, through the cooperation between antenna 100, signal demodulation module 200, and signal processing module 300, the horizontal synchronization signal transmitted by the aircraft can be extracted from the radio signal. Because the horizontal synchronization signal has a high frequency, detecting the horizontal synchronization signal to detect the aircraft can effectively improve the detection speed.

[0065] Furthermore, in the aircraft detection circuit, the signal processing module 300 includes: a line synchronization signal extraction module 301 and a controller 302, such as Figure 2The line synchronization signal extraction module 301 is connected to the signal modulation module 200 and is used to extract the line synchronization signal from the demodulated signal. The controller 302 is connected to the line synchronization signal extraction module 301 and is used to obtain the detection result of the aircraft based on the line synchronization signal.

[0066] For example, when the antenna 100 receives the radio signal of the FPV drone, and the radio signal is transmitted in the PAL format, the signal demodulation module 200 will successfully demodulate the RF signal by performing PAL demodulation, and the obtained demodulated signal is a CVBS video signal. The line synchronization signal extraction module 301 extracts the line synchronization signal from the CVBS video signal. Taking the CVBS video signal as an example, the CVBS video signal (i.e., one of the demodulated signals) obtained after PAL demodulation and the waveform output by the line synchronization signal extraction module 301 are as follows: Figure 9 The signal output by the horizontal synchronization signal extraction module 301 is the horizontal synchronization signal.

[0067] The controller 302 may include a control circuit or a processor. The processor may be a central processing unit (CPU), a microprocessor (MCU), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The specific type of the controller 302 is not limited herein, as long as it can analyze the extracted horizontal synchronization signal.

[0068] The controller 302 is connected to the line synchronization signal extraction module 301 and is used to obtain the detection result of the aircraft based on the line synchronization signal. The detection result of the aircraft includes, for example, the presence or absence of the aircraft in a preset area. The preset area can be within the maximum area where the antenna 100 can receive radio signals, or can be set according to actual detection requirements. This embodiment of the present application does not specifically limit this. Regarding the detection result of the aircraft, for example: if it is determined that a line synchronization signal exists, it is considered that an FPV drone exists; otherwise, it is considered that an FPV drone does not exist.

[0069] In summary, in this embodiment, the controller 302 can determine whether the signal output by the horizontal synchronization signal extraction module 301 includes a horizontal synchronization signal, thereby determining whether an aircraft is present. Specifically, if no horizontal synchronization signal is extracted, the controller 302 determines that an aircraft is not present; if a horizontal synchronization signal is extracted, the controller 302 determines that an aircraft is present.

[0070] Further, such as Figure 7 As shown, the signal demodulation module 200 includes: a signal preprocessing unit 201 and a demodulation unit 202. The signal preprocessing unit 201 is connected to the antenna 100 and is used to preprocess the radio frequency signal. By preprocessing the radio frequency signal, the signal preprocessing unit 201 can improve the signal strength of the radio frequency signal, enhance the anti-interference ability of the signal, and remove the interference signal in the radio frequency signal, so as to facilitate the processing of the subsequent circuit. The demodulation unit (Dem) 202 is connected to the signal preprocessing unit 201 and is used to demodulate the preprocessed radio frequency signal to obtain a demodulated signal. Among them, the demodulation unit 202 can perform demodulation based on the commonly used aircraft video transmission format, such as PAL demodulation or NTSC demodulation. The method used for successful demodulation represents the protocol adopted by the aircraft. The specific method is not limited here.

[0071] Among them, such as Figure 12 As shown, the signal preprocessing unit 201 may include: a filtering unit 2011 and an amplifying unit 2012. The filtering unit 2011 is connected to the antenna 100, and is used to filter the radio frequency signal and remove the interference signal in the radio frequency signal. The amplifying unit 2012 is connected to the filtering unit 2011, and is used to amplify the filtered radio frequency signal and improve the signal strength of the radio frequency signal. The demodulation unit 202 is connected to the amplifying unit 2012, and is used to demodulate the amplified radio frequency signal to obtain a demodulated signal. The positions of the filtering unit 2011 and the amplifying unit 2012 can be swapped, that is, the radio frequency signal can be amplified first and then filtered, which is not limited here.

[0072] It is understandable that the functional units in the signal demodulation module 200, such as the filtering unit 2011, the amplifying unit 2012 and the demodulation unit 202, may include specific functional devices to achieve their respective corresponding functions. For example, the amplifying unit 2012 may include an amplifier for signal amplification, and the filtering unit 2011 may include a filter for signal filtering. Of course, the functional devices included in the signal preprocessing unit 201 may also be configured to provide other signal preprocessing operations other than signal filtering and amplification, such as interference suppression, automatic gain control, etc., which are not listed here. The demodulation unit 202 may include a demodulator for implementing signal demodulation processing. The specific composition of the signal demodulation module 200 may not only be Figure 12 As shown, some units may be added or deleted.

[0073] The demodulated signal may include signals of multiple frequencies. For example, in addition to the horizontal synchronization signal that needs to be extracted, the CVBS video signal also includes other low-frequency signals (such as field synchronization signal) and high-frequency signals (such as color difference signal, brightness signal, etc.). Figure 3 As shown, in this embodiment of the present application, the horizontal synchronization signal extraction module 301 includes a bandpass filter unit 3011. The input of the bandpass filter unit 3011 is connected to the signal demodulation module 200 (specifically, the demodulation unit 202), and the output of the bandpass filter unit 3011 is connected to the controller 302. The center frequency of the bandpass filter unit 3011 is set based on the frequency of the horizontal synchronization signal. For example, it can be set to the frequency of the horizontal synchronization signal or the average of the frequencies of multiple horizontal synchronization signals, although this is not limited here. The term "multiple horizontal synchronization signals" refers to the frequency of multiple horizontal synchronization signals of different frequencies. If the FPV drone uses multiple horizontal synchronization signals, the center frequency of the bandpass filter unit 3011 is the average of the frequencies of these horizontal synchronization signals. The bandpass filter unit 3011 is configured to pass signals within a certain frequency range while blocking or attenuating signals at other frequencies to achieve filtering. The center frequency of the bandpass filter unit 3011 can be adjusted by adjusting the resistance and capacitance values of the bandpass filter unit 3011.

[0074] It is understandable that in practice, the frequency of the line synchronization signal of the video signal is fixed, and the specific value (such as the frequency of the line synchronization signal or the average of the frequencies of multiple line synchronization signals) depends on the actual application scenario. For example, the frequency of the line synchronization signal will be different if the video resolution of the video signal is different. Common FPV drones have two line synchronization signal frequencies: 15.625KHz and 15.73426KHz. The center frequency of the bandpass filter unit 3011 can be set to the average of the frequencies of these two line synchronization signals, that is, the center frequency of the bandpass filter unit 3011 is set to 15.68KHz to ensure that the line synchronization signal can be separated from the CVBS video signals of the above two resolutions to prevent false alarms of the video signal. If there is only one line synchronization signal in the current area, such as 15.625KHz, the center frequency of the bandpass filter unit 3011 is directly set to 15.625KHz. Of course, if the aircraft in the preset area uses other video resolutions for video transmission, the center frequency of the bandpass filter unit 3011 can also be set according to the frequency (or average value of the frequency) of the horizontal synchronization signal corresponding to the video resolution.

[0075] The bandpass filter unit 3011 includes a bandpass filter. It is understood that if a low-pass filter or a high-pass filter is selected, low-frequency signals such as the field synchronization signal or high-frequency signals such as the color difference signal and the luminance signal will also be extracted. The presence of other signals in the extracted horizontal synchronization signal will hinder the subsequent controller 302 from obtaining accurate aircraft detection results based on the horizontal synchronization signal. However, in the embodiment of the present application, a bandpass filter 3011 is used, and the center frequency of the bandpass filter 3011 is set based on the frequency of the horizontal synchronization signal. This allows only the horizontal synchronization signal to be extracted, ensuring accurate aircraft detection.

[0076] Specifically, the bandpass filter unit 3011 includes an active bandpass filter composed of resistors, capacitors, and active components. The order of the active bandpass filter can be set according to actual conditions. For example, a fourth-order active bandpass filter composed of two second-order active bandpass filters can be used, or a higher-order active bandpass filter composed of multiple second-order active bandpass filters can be used. The specific details are not limited here. Compared with passive bandpass filters, active bandpass filters are composed of active components, which can save some resistors and capacitors. The active bandpass filter is smaller in size and easy to integrate.

[0077] Further, such as Figure 8 As shown, the horizontal synchronization signal extraction module 301 includes a bandpass filter unit 3011. Taking the bandpass filter unit 3011 as a fourth-order active bandpass filter, for example, it includes two second-order active bandpass filters: a first second-order active bandpass filter 3011-1 and a second second-order active bandpass filter 3011-2. The first second-order active bandpass filter 3011-1 includes a first resistor R1, a second resistor R2, a third resistor R3, a second capacitor C2, a third capacitor C3, and an operational amplifier U1. The second second-order active bandpass filter 3011-2 includes resistors R4, R5, and R6, capacitors C4 and C5, and an operational amplifier U2.

[0078] In the first second-order active band-pass filter 3011-1, one end of the first resistor R1 is connected to the signal demodulation module 200 for inputting the demodulated signal CVBS_IN. The other end of the first resistor R1 is connected to one end of the second resistor R2, one end of the second capacitor C2, and one end of the third capacitor C3, and the other end of the second resistor R2 is grounded. The other end of the second capacitor C2 is connected to the inverting input of the operational amplifier U1 and one end of the third resistor R3, the non-inverting input of the operational amplifier U1 is grounded, and the other end of the third capacitor C3 and the other end of the third resistor R3 are connected to the output of the operational amplifier U1. The input end of the second second-order active band-pass filter 3011-2 is connected to the output end of the first second-order active band-pass filter 3011-1, and its composition structure is similar to that of the first second-order active band-pass filter 3011-1, and the specific details are not repeated here. It can be understood that the composition structure of the above-mentioned bandpass filter unit 2011 is only an example, and the composition structure of the bandpass filter unit 3011 is not limited to the structure shown in the figure. The number / order of resistors, capacitors or active bandpass filters can be increased or decreased, or the corresponding connection method can be adjusted. No specific limitation is made here.

[0079] It is understandable that in the embodiment of the present application, the bandpass filter unit 3011 adopts a fourth-order active bandpass filter, which can more accurately distinguish between passband and stopband signals compared to a second-order bandpass filter, and only allows signals within a specific narrow frequency range to pass through, and has a stronger ability to suppress interference signals outside the passband. At the same time, the bandpass filter unit 3011 adopts a fourth-order active bandpass filter, which effectively controls the cost while taking into account the extraction effect of the line synchronization signal compared to higher-order bandpass filters. The expanded waveform of the line synchronization signal obtained after filtering by the active bandpass filter is as follows: Figure 10 As shown, as an example, the center frequency of the active bandpass filter is set to 15.68 KHz, and the frequency of the obtained horizontal synchronization signal is generally 15.73426 KHz or 15.625 KHz.

[0080] Further, such as Figure 4 and Figure 8As shown, the horizontal synchronization signal extraction module 301 further includes a first DC blocking unit 3012 and a second DC blocking unit 3015. The first DC blocking unit 3012 is connected between the signal demodulation module 200 and the input of the bandpass filter unit 3011, while the second DC blocking unit 3015 is connected between the output of the bandpass filter unit 3011 and the controller 302. It is understood that demodulated signals of varying strengths (e.g., CVBS video signals) have varying DC components. The first DC blocking unit 3012 is used to filter out the DC component in the demodulated signal output by the signal demodulation module 200 to prevent DC offset from affecting the filtering operation of the bandpass filter unit 3011, thereby improving the filtering accuracy of the bandpass filter unit 3011. For example, the first DC blocking unit 3012 includes a capacitor C1, which performs AC coupling on the demodulated signal via capacitor C1 to filter out unstable DC components in the demodulated signal.

[0081] The second DC isolation unit 3015 is used to filter out the DC component in the horizontal synchronization signal extracted by the band-pass filter unit 301. For example, the second DC isolation unit 3015 includes a capacitor C6, which is used to filter out unstable DC components in the horizontal synchronization signal. By respectively providing the first DC isolation unit 3012 and the second DC isolation unit 3015 at the input and output ends of the band-pass filter unit 3011, the front and back of the band-pass filter unit 3011 are subjected to DC isolation processing, which can further improve the accuracy and stability of the horizontal synchronization signal output by the band-pass filter unit 3011.

[0082] Furthermore, in the embodiment of the present application, the controller 302 can obtain the detection result of the aircraft based on the line synchronization signal. In order to improve the extraction accuracy of the signal amplitude, as shown in FIG. Figure 5 As shown, the horizontal synchronization signal extraction unit 301 further includes an operational amplifier unit 3013. The input end of the operational amplifier unit 3013 is connected to the output end of the bandpass filter unit 3011, and the output end of the operational amplifier unit 3013 is connected to the controller 302. The operational amplifier unit 3013 is configured to amplify the horizontal synchronization signal extracted by the bandpass filter unit 3011 to increase the signal strength of the horizontal synchronization signal.

[0083] For example, Figure 8As shown, the operational amplifier unit 3013 includes: resistors R7, R8, R9, R10, and an operational amplifier U3. Among them, one end of the resistor R7 is connected to the output end of the bandpass filter unit 3011 (or if a second DC isolation unit 3015 is provided, one end of the resistor R7 is connected to the second DC isolation unit 3015), and the other end of the resistor R7 is connected to the non-inverting input end of the operational amplifier U3. One end of the resistor R8 is connected to the inverting input end of the operational amplifier U3 and one end of the resistor R9, and the other end of the resistor R8 is grounded. The output end of the operational amplifier U3 is connected to the other end of the resistor R9 and one end of the resistor R10, and the other end of the resistor R10 is connected to the controller 302. Of course, the composition structure of the operational amplifier unit 3013 is not limited to Figure 8 The structure shown in is not limited here.

[0084] like Figure 6 As shown, the line synchronization signal extraction unit 301 also includes: an envelope detection unit 3014. The input end of the envelope detection unit 3014 is connected to the output end of the operational amplifier unit 3011, and the output end of the envelope detection unit 3014 is connected to the controller 302. The envelope detection unit 3014 is used to receive the amplified line synchronization signal transmitted by the operational amplifier unit 3013 and extract the envelope electrical signal CVBS_DET of the amplified line synchronization signal. It should be noted that in other embodiments, the aircraft detection circuit may not include the operational amplifier unit 3013, and the input end of the envelope detection unit 3014 may be directly connected to the bandpass filter unit 3011, and the output end is connected to the controller 302. At this time, the envelope detection unit 3014 is used to extract the envelope electrical signal of the line synchronization signal.

[0085] It can be understood that the envelope detection unit 3014 extracts the envelope electrical signal of the horizontal synchronization signal output by the bandpass filtering unit 3011, such as Figure 11 When the radio signal received by the antenna 100 contains the radio signal of the FPV drone, the demodulated signal obtained by the signal demodulation module 200 is a CVBS video signal, and the envelope detection unit 3014 can extract the envelope electrical signal CVBS_DET ( Figure 11 The waveform is indicated by the dotted line in the figure).

[0086] For example, the envelope detection unit 3014 includes: a diode D1, a resistor R11 and a capacitor C7. The anode of the diode D1 is connected to the output end of the operational amplifier unit 303, the cathode of the diode D1 is connected to one end of the resistor R11, one end of the capacitor C7 and the controller 302, and the other end of the resistor R11 and the other end of the capacitor C7 are grounded. It is understandable that the specific composition of the envelope detection unit 3014 can be more than Figure 8As shown, the number, connection relationship, etc. of components such as diodes, capacitors, and resistors can also be adjusted according to actual conditions, or other components can be added. The embodiment of the present application does not make specific limitations on this, and it is sufficient to be able to extract the envelope electrical signal of the line synchronization signal.

[0087] Controller 302 is configured to obtain an aircraft detection result based on a comparison of the envelope electrical signal with a preset amplitude threshold. It will be appreciated that the envelope electrical signal is the amplitude of the horizontal synchronization signal. Controller 302 can use the envelope electrical signal to identify whether the horizontal synchronization signal is that of an aircraft, thereby obtaining an aircraft detection result. The preset amplitude threshold is a pre-stored minimum amplitude of an aircraft horizontal synchronization signal.

[0088] As an example, an aircraft detection result can be obtained based on a comparison of the average value of the envelope electrical signal with a preset amplitude threshold. Specifically, if the average value of the envelope electrical signal is greater than or equal to the preset amplitude threshold within a preset time period, the aircraft detection result is that the aircraft is present. If the average value of the envelope electrical signal is less than the preset amplitude threshold, the aircraft detection result is that the aircraft is not present. It will be appreciated that in this embodiment, the envelope electrical signal is extracted by the envelope detection unit 3014, and the aircraft detection result is obtained by taking the average value of the envelope electrical signal. Because the frequency of the envelope electrical signal is lower than that of the horizontal synchronization signal, the controller 302 does not need to have a very high sampling rate, and the performance requirements of the controller 302 are lower, which can effectively reduce the cost of the detection circuit. Furthermore, in this embodiment of the present application, the horizontal synchronization signal is identified using a preset amplitude threshold, eliminating the need to set a reference voltage on the hardware side of the detection circuit. If the application environment changes (for example, the type of aircraft changes), the new aircraft type can be detected by simply changing the preset amplitude threshold in software. This allows for wider application scenarios, improves the integration of the detection circuit, and effectively saves costs.

[0089] Next, Figure 6 Combine Figure 7 、 Figure 8As an example, the specific principles of the aircraft detection circuit in the embodiment of the present application are explained. The aircraft detection circuit includes an antenna 100, a signal demodulation module 200 and a signal processing module 300. Take an FPV drone that uses the PAL format for video signal transmission as an example. The antenna 100 is used to receive the radio signal of the FPV drone and convert the radio signal into a radio frequency signal. The signal demodulation module 200 includes a signal preprocessing unit 201 and a demodulation unit 202. The signal preprocessing unit 201 performs signal preprocessing operations such as filtering and amplification on the radio frequency. The demodulation unit 202 performs PAL demodulation on the preprocessed radio frequency signal to obtain a demodulated signal, that is, a CVBS video signal. The signal processing module 300 includes a line synchronization signal module 301 and a controller 302. Among them, the line synchronization signal module 301 includes a bandpass filter unit 3011, an operational amplifier unit 3013 and an envelope detection unit 3014. The center frequency of the bandpass filter unit 3011 is set to the frequency of the horizontal synchronization signal or the average of the frequencies of multiple horizontal synchronization signals, thereby filtering out other high-frequency and low-frequency signals in the CVBS video signal and extracting the horizontal synchronization signal from the CVBS video signal. The input and output of the bandpass filter unit 3011 are connected to the first DC isolation unit 3012 and the second DC isolation unit 3015, respectively. The operational amplifier unit 3013 amplifies the DC-isolated horizontal synchronization signal, and the envelope detection unit 3014 extracts the envelope electrical signal of the amplified horizontal synchronization signal. Based on the comparison of the envelope electrical signal with a preset amplitude threshold, the controller 302 obtains the aircraft detection result, namely, whether an FPV drone is in the relevant area. Compared to other communication signals, the horizontal synchronization signal has a faster frequency, a shorter sweep period, and a faster frequency scanning speed. Therefore, this solution uses the extracted horizontal synchronization signal for aircraft detection, effectively improving aircraft detection speed.

[0090] An embodiment of the present application also provides an aircraft detection device, including the aircraft detection circuit described above. It is understood that the aircraft detection device also includes components such as a memory and a processor, the specifics of which are not limited herein. The aircraft detection circuit is configured to receive a radio signal, convert the radio signal into a radio frequency signal, and demodulate the radio frequency signal to generate a demodulated signal. A line synchronization signal is extracted from the demodulated signal, and an aircraft detection result is obtained based on the line synchronization signal.

[0091] The present application also provides an aircraft detection method, which is applied to an aircraft detection device, such as Figure 13 As shown, the specific steps include:

[0092] 1301. Receive a radio signal and convert the radio signal into a radio frequency signal.

[0093] In the embodiment of the present application, a radio signal can be received by an antenna and converted into a radio frequency signal.

[0094] 1302. Demodulate the radio frequency signal based on a signal transmission mode of the radio signal in the aircraft to obtain a demodulated signal.

[0095] In embodiments of the present application, the radio frequency signal may be demodulated based on a radio signal transmission method commonly used by aircraft to obtain a demodulated signal. This demodulation method may include PAL demodulation, NTSC demodulation, SECAM NTSC demodulation, etc. When the received radio signal contains a radio signal from an aircraft, the demodulated signal obtained by the demodulation process includes a video signal from the aircraft.

[0096] 1303. Extract a row synchronization signal from the demodulated signal, and obtain a detection result of the aircraft based on the row synchronization signal.

[0097] In an embodiment of the present application, the demodulated signal can be bandpass filtered based on the center frequency of the horizontal synchronization signal to extract the horizontal synchronization signal from the demodulated signal. Furthermore, the horizontal synchronization signal can be amplified, and the envelope electrical signal of the amplified horizontal synchronization signal can be extracted. The resulting envelope electrical signal is the signal amplitude of the horizontal synchronization signal. Aircraft detection results are obtained based on the envelope electrical signal. In this embodiment, aircraft detection results can be obtained by comparing the average value of the envelope electrical signal within a preset time period with a preset amplitude threshold.

[0098] The present application also provides an aircraft detection method, for example, applied to a controller, which may be a control circuit or a processor, and the specific details are not limited here. The controller can be used alone or applied to an aircraft detection device. The aircraft detection method is as follows: Figure 14 As shown, the specific steps include:

[0099] 1401. Obtain an envelope electrical signal corresponding to a horizontal synchronization signal.

[0100] In embodiments of the present application, an envelope electrical signal corresponding to a horizontal synchronization signal can be obtained, where the horizontal synchronization signal is obtained from a received radio signal. The radio signal can be received via an antenna, and the horizontal synchronization signal can be extracted from the radio signal. Envelope detection is performed on the horizontal synchronization signal to obtain the corresponding envelope electrical signal.

[0101] 1402. Obtain a detection result of the aircraft based on a comparison result of the envelope electrical signal and a preset amplitude threshold.

[0102] After acquiring the envelope electrical signal corresponding to the horizontal synchronization signal, the aircraft detection result can be obtained based on the comparison result of the envelope electrical signal with a preset amplitude threshold. Specifically, if the average amplitude of the envelope electrical signal within a preset time period is greater than or equal to the preset amplitude threshold, the aircraft detection result is determined to be the presence of the aircraft. If the average amplitude of the envelope electrical signal is less than the preset amplitude threshold, the aircraft detection result is determined to be the absence of the aircraft.

[0103] It should be noted that those skilled in the art will clearly understand that, for the sake of convenience and brevity of description, the specific working process of the above-described aircraft detection method can refer to the corresponding process in the aforementioned aircraft detection circuit embodiment, and will not be repeated here.

[0104] An embodiment of the present application further provides a computer-readable storage medium, which includes instructions. When the instructions are executed on a computer, the computer executes the method described above.

[0105] Those skilled in the art will clearly understand that 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 the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0106] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0107] The above embodiments are only used to illustrate the technical solutions of the embodiments of the present application, rather than to limit them. Although the embodiments of the present application are described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. These modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specifications of the embodiments of the present application.

Claims

1. An aircraft detection circuit, characterized in that: include: Antenna, signal demodulation module and signal processing module; The antenna is used to receive radio signals and convert the radio signals into radio frequency signals; The signal demodulation module is connected to the antenna and is used to demodulate the radio frequency signal to obtain a demodulated signal; The signal processing module is connected to the signal demodulation module, and is used to extract a row synchronization signal from the demodulated signal, and obtain a detection result of the aircraft based on the row synchronization signal.

2. The aircraft detection circuit according to claim 1, characterized in that: The signal processing module includes: a horizontal synchronization signal extraction module and a controller; The row synchronization signal extraction module is connected to the signal mediation module and is used to extract the row synchronization signal from the demodulated signal; The controller is connected to the line synchronization signal extraction module and is used to obtain the detection result of the aircraft based on the line synchronization signal.

3. The aircraft detection circuit according to claim 2, characterized in that: The horizontal synchronization signal extraction module includes: a bandpass filtering unit; The input end of the bandpass filtering unit is connected to the signal demodulation module, and the output end of the bandpass filtering unit is connected to the controller; wherein the center frequency of the bandpass filtering unit is the frequency of the line synchronization signal or the average value of the frequencies of multiple line synchronization signals.

4. The aircraft detection circuit according to claim 3, characterized in that: The horizontal synchronization signal extraction module further includes: a first DC isolation unit and a second DC isolation unit; The first DC isolation unit is connected between the output end of the signal demodulation module and the input end of the bandpass filtering unit; The second DC isolation unit is connected between the output end of the bandpass filtering unit and the controller.

5. The aircraft detection circuit according to claim 3, characterized in that: The horizontal synchronization signal extraction module further includes: an operational amplifier unit; The input end of the operational amplifier unit is connected to the output end of the band-pass filter unit, and the output end of the operational amplifier unit is connected to the controller; The operational amplifier unit is used to amplify the horizontal synchronization signal.

6. The aircraft detection circuit according to claim 3, characterized in that: The horizontal synchronization signal extraction module further includes: an envelope detection unit; The input end of the envelope detection unit is connected to the output end of the bandpass filtering unit, and the output end of the envelope detection unit is connected to the controller; The envelope detection unit is used to extract the envelope electrical signal of the horizontal synchronization signal; The controller is used to obtain a detection result of the aircraft based on a comparison result of the envelope electrical signal and a preset amplitude threshold.

7. The aircraft detection circuit according to claim 1, characterized in that: The signal demodulation module includes: a signal preprocessing unit and a demodulation unit; The signal preprocessing unit is connected to the antenna and is used to preprocess the radio frequency signal; The input end of the demodulation unit is connected to the signal preprocessing unit, and the output end of the demodulation unit is connected to the signal processing module; the demodulation unit is used to demodulate the preprocessed RF signal to obtain a demodulated signal.

8. An aircraft detection device, characterized in that: The aircraft detection circuit comprises the aircraft detection circuit according to any one of claims 1 to 7.

9. An aircraft detection method, applied to an aircraft detection device, characterized in that: include: receiving a radio signal and converting the radio signal into a radio frequency signal; Demodulating the radio frequency signal based on the signal transmission mode of the aircraft radio signal to obtain a demodulated signal; A row synchronization signal is extracted from the demodulated signal, and a detection result of the aircraft is obtained based on the row synchronization signal.

10. A method for detecting an aircraft, characterized in that: include: Acquire an envelope electrical signal corresponding to a horizontal synchronization signal; the horizontal synchronization signal is obtained from a received radio signal; Based on the comparison result of the envelope electrical signal and the preset amplitude threshold, the detection result of the aircraft is obtained.

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