An identity recognition method, device, electromagnetic license plate and system based on electromagnetic control

Abstract

The present invention discloses an identity recognition method, device, electromagnetic license plate and system based on electromagnetic control. The present invention designs a time-coded metasurface according to the identity recognition code. The metasurface modulates different frequency deviations on the reflected echo based on the sequence corresponding to the recognition code, and the receiving end can parse the identity recognition code and distance information based on the echo signal. Based on this idea, the present invention innovatively uses the time-coded metasurface to design a new electromagnetic license plate. Under the premise that the controlled object does not actively transmit a signal, its identity information is modulated on the electromagnetic echo, and the echo intensity is enhanced at the same time; the receiving end obtains the distance information and identity recognition code of the controlled object from the echo through the corresponding signal processing method. Compared with the existing control method, the new license plate proposed by the present invention can use the electromagnetic wave transceiver to achieve echo enhancement, long-distance ranging and accurate identity recognition of the controlled object without increasing the volume and power consumption of the controlled object.

Description

Technical Field

[0001] The present invention belongs to the field of long-distance identity recognition and traffic (drone, motor vehicle, non-motor vehicle, etc.) control, and in particular relates to an identity recognition method and device based on electromagnetic control, and an electromagnetic license plate and system. Background Art

[0002] In the modern transportation system, the widespread use of various means of transportation such as drones, motor vehicles, non-motor vehicles and ships has brought great challenges to detection and identification.

[0003] Accurately acquiring the location and identity information of various vehicles is crucial. From a safety perspective, accurately identifying drones in airspace effectively safeguards flight safety. Precisely locating and identifying motor vehicles and non-motor vehicles on land helps maintain road traffic order. Accurately detecting vessels in waters ensures navigation safety. From a traffic management efficiency perspective, effective detection and identification of vehicles facilitates precise control of intelligent transportation systems, rationally allocating road, flight routes, or port resources, alleviating congestion, and improving transportation efficiency.

[0004] At the same time, traditional detection and identification methods are increasingly vulnerable to the current complex regulatory environment. While ground-based radar can acquire target location information, it cannot identify the target and has limitations in detecting small, long-range targets. Video surveillance systems can capture vehicle license plate information, but due to hardware and environmental constraints, the camera's resolution and focal length limit its ability to capture distant targets, resulting in significant deficiencies in long-range detection and identification. In poor lighting conditions or inclement weather, video surveillance image quality degrades dramatically, even rendering it incapable of capturing valid information. While radio frequency identification (RFID) technology can identify objects, it is limited by its range and the additional hardware required to identify them. In RFID, an electronic tag is attached to the object being identified. When the tag enters the magnetic field of the reader's antenna, it activates, limiting the RFID's range. Furthermore, the activated tag transmits its stored information to the reader via a built-in antenna in the form of a radio frequency signal. This means that RFID requires additional antennas and other equipment for identification, placing strict power requirements on these devices.

[0005] As regulatory authorities increasingly demand more intelligent and sophisticated security controls, existing technologies are no longer sufficient to accurately detect and identify drones, motor vehicles, and non-motor vehicles from a distance. Developing a system capable of remotely detecting the distance of controlled objects and accurately identifying their ID codes has become a pressing need to address current security regulatory challenges. Summary of the Invention

[0006] Purpose of the invention: In view of the shortcomings of the existing technology, the purpose of the present invention is to provide an identity recognition method, device, electromagnetic license plate and system based on electromagnetic control, which can detect the target distance from a long distance and accurately identify the target's identity information without the need for the target to actively transmit a signal.

[0007] Technical solution: To achieve the above-mentioned purpose, the specific technical solution of the present invention is as follows:

[0008] In a first aspect, the present invention provides an identity recognition method based on electromagnetic control, comprising the following steps:

[0009] Transmitting electromagnetic waves toward an object to be identified and receiving an echo reflected by a time-coding metasurface mounted on the object to be identified; the time-coding metasurface is designed according to an identification code assigned to the object to be identified, and modulates the reflected echo with different frequency offsets based on a sequence corresponding to the identification code;

[0010] The received echo is preliminarily decoded to obtain a sequence, and the starting segment of the preset sequence is located. Based on the starting segment of the preset sequence, the time delay difference between the metasurface time modulation and the transmitted signal is estimated. The frequency offset of the echo signal is compensated by combining the sequence and the time delay difference.

[0011] The identification code is decoded on the echo after frequency offset compensation to obtain the identity information of the object to be identified.

[0012] Preferably, in the sequence obtained by performing preliminary decoding on the received echo, a sliding search is performed on the echo using a sliding window, the signal frequency in each sliding window is obtained using Fourier transform, and the sequence corresponding to the modulation is determined according to the frequency deviation.

[0013] Preferably, in estimating the time delay difference between the metasurface time modulation and the transmitted signal, a sliding window is used to search the frequency spectrum corresponding to the starting segment of a preset sequence in the echo signal, and the time delay difference is estimated based on the frequency hopping position therein.

[0014] Preferably, in the frequency offset compensation of the echo signal by combining the sequence and the delay difference, the echo signal is divided into a series of signal blocks according to the modulation period of the time-coded metasurface, and the frequency offset compensation is performed on each echo signal block. If the frequency offset corresponding to the first half of the encoding of an echo signal block is f pre , the frequency deviation corresponding to the second half of the coding is f post , increase the frequency deviation by sampling point in the second half of the signal block ( f pre -f post ).

[0015] Preferably, decoding the identification code of the echo after frequency offset compensation includes: performing Fourier transform on each signal block, determining the frequency offset according to the peak position of the Fourier transform, and then judging the code corresponding to the signal block.

[0016] Furthermore, the identity recognition method based on electromagnetic control also includes: using the echo after frequency offset compensation and the decoding result to perform ranging.

[0017] Preferably, the distance measurement is performed using the echo after frequency offset compensation and the decoding result, including: determining the reference signal of each signal block according to the decoding result, correlating the reference signal of each signal block with the echo signal block after frequency offset compensation, determining the delay according to the peak position of the correlation function, and converting it into distance.

[0018] In a second aspect, the present invention provides a method for electromagnetically controlling identity information, comprising the following steps:

[0019] Assign a unique identification code to the object to be identified as identity information;

[0020] A time-coding metasurface installed on the object to be identified is designed based on the identification code. The time-coding metasurface reflects the electromagnetic waves emitted by the identification terminal and modulates the reflected echo with different frequency deviations based on the sequence corresponding to the identification code, so that the identification terminal can obtain the identity information of the object to be identified based on the reflected echo.

[0021] Preferably, when designing a time-coded metasurface, a preset sequence starting segment is added to the beginning of the corresponding sequence of the identification code to find the starting point of the sequence. The preset sequence starting segment is a sequence with values ​​ranging from 0 to M-1, and the values ​​of two adjacent elements are different. M indicates that the sequence is an M-ary sequence.

[0022] Preferably, the reflection coefficient of the time-coded metasurface varies periodically with time, and the frequency modulation strategy is as follows:

[0023]

[0024] in, t Indicates time, represents the phase component of the reflection coefficient, f 1 to f M is the frequency deviation that the metasurface modulates the reflected echo when corresponding to codes 0 to M-1, and M indicates that the sequence is an M-ary sequence.

[0025] In a third aspect, the present invention provides an identity recognition device based on electromagnetic control, which is used to implement the identity recognition method based on electromagnetic control described in the first aspect, including an electromagnetic wave transmitting device, an electromagnetic wave receiving device and an identification module;

[0026] The electromagnetic wave transmitting device is used to transmit electromagnetic waves to the object to be identified;

[0027] The electromagnetic wave receiving device is used to receive the echo reflected by the time coding metasurface installed on the object to be identified; the time coding metasurface is designed according to the identification code assigned to the object to be identified, and modulates the reflected echo with different frequency offsets based on the sequence corresponding to the identification code;

[0028] The identification module is used to perform preliminary decoding on the received echo to obtain a sequence, locate the starting segment of the preset sequence, estimate the time delay difference between the metasurface time modulation and the transmitted signal based on the starting segment of the preset sequence, and compensate the frequency offset of the echo signal in combination with the sequence and the time delay difference; and decode the identification code of the echo after frequency offset compensation to obtain the identity information of the object to be identified.

[0029] In a fourth aspect, the present invention provides an electromagnetic control device for identity information, which is used to implement the electromagnetic control method for identity information described in the second aspect, including a time-coding metasurface and a control module. The control module is used to design a time-coding metasurface according to a unique identification code assigned to an object to be identified. The time-coding metasurface is used to reflect the electromagnetic waves emitted by the identity recognition end, and modulate different frequency deviations of the reflected echo based on the sequence corresponding to the identification code, so that the identity recognition end can obtain the identity information of the object to be identified based on the reflected echo.

[0030] In a fifth aspect, the present invention provides an electromagnetic license plate, mounted on a controlled object, and implemented using an electromagnetic control device based on the aforementioned identity information; wherein the object to be identified is the controlled object. In a specific implementation, the controlled object is an unmanned aerial vehicle, a motor vehicle, a non-motor vehicle, or a vessel.

[0031] In a sixth aspect, the present invention provides an identity recognition system based on electromagnetic control, comprising: an identity recognition device for implementing the identity recognition method based on electromagnetic control described in the first aspect, and an electromagnetic control device for implementing the electromagnetic control method for identity information described in the second aspect;

[0032] The identity recognition device includes an electromagnetic wave transmitting device, an electromagnetic wave receiving device and an identification module; the electromagnetic wave transmitting device is used to transmit electromagnetic waves to the object to be identified; the electromagnetic wave receiving device is used to receive the echo reflected by the time-coding metasurface installed on the object to be identified; the time-coding metasurface is designed according to the identification code assigned to the object to be identified, and modulates the reflected echo with different frequency offsets based on the sequence corresponding to the identification code; the identification module is used to perform preliminary decoding on the received echo to obtain a sequence, locate the starting segment of the preset sequence, estimate the time delay difference between the metasurface time modulation and the transmitted signal based on the starting segment of the preset sequence, and perform frequency offset compensation on the echo signal in combination with the sequence and the time delay difference; and decode the identification code of the echo after frequency offset compensation to obtain the identity information of the object to be identified;

[0033] The electromagnetic control device includes a time-coding metasurface and a control module. The control module is used to design a time-coding metasurface according to a unique identification code assigned to the object to be identified. The time-coding metasurface is used to reflect the electromagnetic waves emitted by the identity recognition end and modulate different frequency deviations of the reflected echo based on the sequence corresponding to the identification code, so that the identity recognition end can obtain the identity information of the object to be identified based on the reflected echo.

[0034] In the seventh aspect, the present invention provides a computer system comprising a memory, a processor, and a computer program stored in the memory and runnable on the processor, wherein when the computer program is executed by the processor, the steps of the electromagnetic control-based identity recognition method described in the first aspect are implemented.

[0035] In an eighth aspect, the present invention provides a computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the steps of the electromagnetic control-based identity recognition method described in the first aspect.

[0036] In a ninth aspect, the present invention provides a computer program product, comprising a computer program, characterized in that when the computer program is executed by a processor, the steps of the electromagnetic control-based identity recognition method described in the first aspect are implemented.

[0037] Beneficial Effects: This invention utilizes a time-modulated metasurface and an electromagnetic wave transceiver (such as a radar or base station). Through the design of the metasurface and signal processing at the receiving end, it is capable of long-distance ranging and precise identification of controlled objects. Compared with the existing technology, it has the following advantages: 1. The present invention utilizes a metasurface to modulate electromagnetic waves, transmitting the identity information of the controlled object through the echo, thereby overcoming the shortcomings of traditional radars in accurately identifying the identity of controlled objects and the limited recognition distance of optical systems. 2. The present invention does not require the controlled object to actively transmit signals, and does not increase the size or power consumption of the controlled object. 3. The present invention achieves echo enhancement through the design of the metasurface, thereby increasing the detection probability and effective range of the target. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a flow chart of an identity recognition method based on electromagnetic control according to an embodiment of the present invention.

[0039] Figure 2 This is a flow chart of the electromagnetic control method of identity information according to an embodiment of the present invention.

[0040] Figure 3 The following is a detailed implementation flow chart of the present invention in the field of traffic control.

[0041] Figure 4 This is a diagram of a super-surface multi-layer composite structure exemplified in an embodiment of the present invention.

[0042] Figure 5 This is a graph showing how the reflected amplitude and phase of the metasurface measured in an embodiment of the present invention change with the bias voltage at a center frequency of 4.25 GHz.

[0043] Figure 6 Graph showing the intensity of the echo reflected at different angles by the metasurface used as an example in an embodiment of the present invention.

[0044] Figure 7 This is a diagram showing the ranging effect in an embodiment of the present invention.

[0045] Figure 8 This is a decoding effect diagram in an embodiment of the present invention.

[0046] Figure 9 Schematic diagram of the structure of an identity recognition device based on electromagnetic control according to an embodiment of the present invention.

[0047] Figure 10 Schematic diagram of the structure of the electromagnetic control device for identity information according to an embodiment of the present invention.

[0048] Figure 11 Schematic diagram of the structure of an identity recognition system based on electromagnetic control according to an embodiment of the present invention. DETAILED DESCRIPTION

[0049] The present invention is further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, modifications of various equivalent forms of the present invention made by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0050] In one embodiment, Figure 1 As shown, an identity recognition method based on electromagnetic control is provided, which is described by applying the method to an electromagnetic wave processing end, and includes the following steps:

[0051] Step S110: Emitting electromagnetic waves toward the object to be identified and receiving an echo reflected by a time-coding metasurface installed on the object to be identified; the time-coding metasurface is designed according to the identification code assigned to the object to be identified, and modulates the reflected echo with different frequency offsets based on the sequence corresponding to the identification code.

[0052] In this step, the reflected echo can be modulated with different frequency offsets based on the binary coding sequence corresponding to the identification code. It should be understood that the purpose of modulation is to allow the echo to carry the identity information of the identified object. In practical applications, as long as the frequency offset modulation capability of the time-coding metasurface meets the requirements, the binary coding can be extended to any base of coding. For different codes in the sequence corresponding to the identification code, the time-coding metasurface modulates different frequency offsets on the reflected echo. The transmitted electromagnetic wave signal can be a pulse signal. While ensuring the ranging performance, the transmitted signal can also be extended from a pulse signal to an electromagnetic wave signal of any form.

[0053] Step S120: Perform preliminary decoding on the received echo to obtain a sequence, locate the starting segment of the preset sequence, estimate the time delay difference between the metasurface time modulation and the transmitted signal based on the starting segment of the preset sequence, and perform frequency offset compensation on the echo signal based on the sequence and the time delay difference.

[0054] For example, a method for performing preliminary decoding on the received echo to obtain a sequence is to define a sliding window with a length of N sampling points, use the sliding window to perform a sliding search on the echo, use a fast Fourier transform (FFT) to obtain the signal frequency within each sliding window, and determine the sequence corresponding to the modulation based on the frequency deviation.

[0055] In this step, the starting segment of the preset sequence is located, that is, a sliding match is performed between the known preset sequence and the initially decoded sequence to find the portion of the sequence that is identical to the preset sequence.

[0056] In this step, the echo signal is divided into a series of signal blocks according to the modulation period of the time coding metasurface. Assume that the time coding metasurface is T block If the encoding is changed once in time, the length of the echo signal block is T blockIt is assumed that there is a relationship between the emission of electromagnetic waves and the temporal modulation of the metasurface. The delay difference is that there is a first half of the signal block ( ) is modulated by the metasurface on the frequency deviation corresponding to the previous code, and the second half ( ) is modulated by the metasurface and corresponds to the frequency offset of the subsequent code. This offset needs to be compensated for in order to accurately decode and measure distance. The sliding window obtained from the initial decoding is used to search the spectrum corresponding to the start of the preset sequence in the echo signal. The delay difference is estimated based on the frequency hop position within the frequency hop.

[0057] Accordingly, the frequency offset compensation method for each echo signal block is as follows: Assume that the first half of a certain echo signal block ( )The frequency deviation corresponding to the coding c_pre is f pre , the second half ( )The frequency deviation corresponding to the code c_post is f post . Increase the frequency deviation by sampling point in the second half of the signal block ( f pre -f post ).

[0058] Step S130: decoding the identification code of the echo after frequency offset compensation to obtain the identity information of the object to be identified.

[0059] Exemplarily, one method for decoding the identification code of the echo after frequency offset compensation is to perform Fourier transform on each signal block, determine the frequency offset according to the peak position of the Fourier transform, and then determine the code corresponding to the signal block.

[0060] In one embodiment, the provided electromagnetic control-based identity recognition method further includes: step S140, performing ranging using the echo after frequency offset compensation and the decoding result.

[0061] In this step, one method that can be used to measure distance using the echo after frequency offset compensation and the decoding result is: determine the reference signal of each signal block based on the decoding result, use the reference signal of each signal block to correlate with the echo signal block after frequency offset compensation, determine the delay based on the peak position of the correlation function, and convert it into distance.

[0062] The electromagnetically controlled identity recognition method of the above embodiment can identify the identity information of the object to be identified from the echo reflected by the metasurface, thereby realizing accurate identity information acquisition and distance estimation at a long distance.

[0063] The above describes the identity recognition method based on electromagnetic control from the perspective of echo recognition. The following describes the electromagnetic control method of identity information from the perspective of metasurface time modulation.

[0064] In one embodiment, Figure 2 As shown, a method for electromagnetic control of identity information is provided, which is described by applying the method to an object to be identified, and includes the following steps:

[0065] Step S210: assigning a unique identification code to the object to be identified as identity information.

[0066] Step S220: A time-coding metasurface installed on the object to be identified is designed based on the identification code. The time-coding metasurface reflects the electromagnetic waves emitted by the identification terminal and modulates different frequency deviations of the reflected echo based on the sequence corresponding to the identification code, so that the identification terminal can obtain the identity information of the object to be identified based on the reflected echo.

[0067] In step S220, when designing a time-coded metasurface, a preset sequence start segment is added to the beginning of the corresponding sequence of the identification code to find the sequence starting point. The preset sequence start segment is a sequence with values ​​ranging from 0 to M-1, where the values ​​of two adjacent elements are different, and M indicates that the sequence is an M-ary sequence. For example, for a binary sequence, a sequence with 0 / 1 intervals can be added to the beginning.

[0068] The reflection coefficient of the time-coded metasurface varies periodically over time. An example frequency modulation strategy is as follows:

[0069]

[0070] in, t Indicates time, represents the phase component of the reflection coefficient, f 1 to f M is the frequency deviation that the metasurface modulates the reflected echo when corresponding to codes 0 to M-1.

[0071] The electromagnetic control method of identity information in the above embodiment, through the design of the time-coding metasurface, allows the identification object to transmit its own identity information to the identification terminal without actively transmitting signals and without increasing volume and power consumption.

[0072] In traffic control scenarios, the objects to be identified are drones, motor vehicles, non-motor vehicles, and other controlled objects. The assigned identification code information is the license plate information. The following uses the traffic control scenario as an example to illustrate the design and effectiveness of electromagnetic control-based identity / license plate recognition.

[0073] like Figure 3 As shown, in an embodiment of a new license plate application for traffic control, an identity design and recognition method based on electromagnetic control is provided, including the following steps:

[0074] Step S310: assigning a unique binary identification code to each controlled object (drone, motor vehicle, non-motor vehicle, etc.);

[0075] In step S310 , a unique binary code sequence is generated for the control object, and a sequence of 0 / 1 intervals (such as 1010101) is added to the beginning of the sequence.

[0076] Step S320: Design a time-coded metasurface according to the binary identification code and install it on the managed object.

[0077] In this embodiment, the metasurface reflection coefficient of the time-coded metasurface varies periodically with time, and its time-varying reflection coefficient is modeled as:

[0078]

[0079] in, A ( t )and Represents the reflection coefficient The time-varying amplitude and phase components of . Since the metasurface involved in this embodiment is a phase modulation metasurface, in order to simplify the derivation assumption A ( t ) is a constant, normalized to 1. Based on the binary identification code, the frequency modulation strategy of the metasurface is designed as follows:

[0080]

[0081] in, f 1 is the frequency deviation of the reflected echo modulated by the metasurface.

[0082] In this embodiment, a 12×16 fully phase-modulated programmable metasurface is used to achieve a continuously adjustable reflection phase of 0-360° by dynamically adjusting the bias voltage of the varactor diodes on both sides of the metasurface unit. Figure 4 As shown, the metasurface adopts a multi-layer composite structure design: the top layer is a rectangular patch array with optimized electromagnetic properties; the middle dielectric layer adopts low-loss F4B ( ) substrate; the bottom layer is a floor covered with copper metal. Specific parameters include length L =24mm, width W =12mm, thickness H =5mm, spacing P =5.6mm. In terms of feeding network design, metasurface units in the same column share the same control signal to reduce circuit complexity. Figure 5The measured reflection amplitude and phase curves of the metasurface at a center frequency of 4.25 GHz are shown as a function of bias voltage. The experimental results show that when the bias voltage is linearly adjusted between 0 and 14 V, the dynamic range of the unit reflection phase covers the entire 360° phase space while maintaining a stable reflection amplitude of |Γ| > -3 dB, meeting the application requirements of the metasurface of the present invention.

[0083] Step S330: Utilize the electromagnetic wave transmitting device to transmit a pulse signal to the controlled object.

[0084] Step S340: using an electromagnetic wave receiving device to receive the echo reflected by the control target.

[0085] Step S350: Estimate the time delay difference between the metasurface time modulation and the pulse transmission, and perform compensation correction. Assume that the transmission pulse width is T pulse , there is a relationship between pulse emission and metasurface temporal modulation The delay difference of the first half of the pulse ( ) is modulated by the metasurface on the phase corresponding to the previous encoding, and the second half ( ) is modulated by the metasurface with the phase corresponding to the next encoding. The echo is searched using a sliding window, and every N step sampling points, select N slide The signal of the length is converted into the frequency domain to determine its center frequency. Preliminary decoding is performed according to the frequency in the search result to obtain a roughly decoded binary sequence. Find the part in the sequence that is the same as the known preset sequence (0 / 1 interval sequence), that is, locate the beginning of the original sequence. At the same time, based on the frequency hopping position in the search result, estimate the delay difference, that is, based on the part corresponding to the 0 / 1 interval sequence in the search result, average the delay difference corresponding to the frequency hopping position in each signal block. Based on the estimated delay difference And the sequence obtained by coarse decoding, each echo pulse is compensated: if the previous code corresponding to the echo pulse is 0 and the next code is 1, then in the second half Increase -2 f 1 frequency deviation; if the previous code corresponding to the echo pulse is 1 and the next code is 0, then in the second half Increase 2 f If the previous and subsequent codes are consistent, the pulse does not need to be compensated.

[0086] Step S360: Decode the identification code of the echo after frequency offset compensation. Perform Fourier transform on each pulse, determine the frequency offset based on the Fourier transform peak position, and then determine the binary code corresponding to the pulse.

[0087] Step S370: perform ranging based on the echo after frequency offset compensation and the decoding result. First, determine the reference signal of each pulse based on the decoding result, that is, the radar transmission signal superimposed with the corresponding frequency offset ( f 1 or - f 1). The reference signal of each pulse is correlated with the frequency offset compensated echo pulse, and the time delay is determined based on the peak position of the correlation function and converted into distance.

[0088] Step S380: Obtain the distance information and identification code of the controlled object. Remove the leading sequence from the binary code obtained in step S360 to obtain the binary identification code of the controlled object. Average the distance measurement results for each pulse in step S370 to obtain the distance between the controlled object and the electromagnetic wave transceiver.

[0089] In summary, the electromagnetic control-based identity design and recognition method of this embodiment uses a metasurface structure such as Figure 4 As shown in the figure, the measured reflection amplitude and phase of the metasurface at the center frequency of 4.25 GHz vary with the bias voltage. Figure 5 shown. Figure 6 is the intensity of the echo reflected by the metasurface at different angles. "Modulation Code 1" indicates the echo intensity when the metasurface is at the phase corresponding to Modulation Code 1, "Modulation Code 0" indicates the echo intensity when the metasurface is at the phase corresponding to Modulation Code 0, and "Metal Surface" indicates that the metasurface is inactive and only reflects the echo intensity of a metal plate. This embodiment can effectively enhance radar echoes and improve the detection probability of controlled targets. Figure 7 This is a distance measurement effect diagram in this embodiment, where the control target is at a distance of 4000m. As can be seen, this embodiment can effectively obtain the distance information of the control target. Figure 8 This is a diagram showing the decoding effect in this embodiment. It can be seen that this embodiment accurately decodes the binary identity identification code of the controlled object.

[0090] The above describes the relevant method embodiments. The following describes the relevant devices at the identification end and the object to be identified end, as well as the entire identification system and program product.

[0091] In one embodiment, Figure 9 As shown, an identity recognition device based on electromagnetic control is provided, including an electromagnetic wave transmitting device, an electromagnetic wave receiving device and an identification module;

[0092] The electromagnetic wave transmitting device is used to transmit electromagnetic waves to the object to be identified;

[0093] The electromagnetic wave receiving device is used to receive the echo reflected by the time coding metasurface installed on the object to be identified; the time coding metasurface is designed according to the identification code assigned to the object to be identified, and modulates the reflected echo with different frequency offsets based on the sequence corresponding to the identification code;

[0094] The identification module is used to perform preliminary decoding on the received echo to obtain a sequence, locate the starting segment of the preset sequence, estimate the time delay difference between the metasurface time modulation and the transmitted signal based on the starting segment of the preset sequence, and compensate the frequency offset of the echo signal in combination with the sequence and the time delay difference; and decode the identification code of the echo after frequency offset compensation to obtain the identity information of the object to be identified.

[0095] In one embodiment, optionally, the identification module of the provided electromagnetic control-based identity recognition device further uses the echo after frequency offset compensation and the decoding result to perform ranging.

[0096] The implementation details of each module of the electromagnetic control-based identity recognition device provided in the embodiment refer to the implementation details of each step of the electromagnetic control-based identity recognition method provided in the above embodiment, which will not be repeated here.

[0097] In one embodiment, Figure 10 As shown, an electromagnetic control device for identity information is provided, including a time-coding metasurface and a control module. The control module is used to design a time-coding metasurface according to a unique identification code assigned to an object to be identified. The time-coding metasurface is used to reflect the electromagnetic waves emitted by the identity recognition end, and modulate different frequency deviations of the reflected echo based on the sequence corresponding to the identification code, so that the identity recognition end can obtain the identity information of the object to be identified based on the reflected echo.

[0098] The implementation details of each module of the electromagnetic control device for identity information provided in the embodiment refer to the implementation details of each step of the electromagnetic control method for identity information provided in the above embodiment, which will not be repeated here.

[0099] In one embodiment, an electromagnetic license plate is provided. The device is mounted on a controlled object and implemented using an electromagnetic control device based on identity information. The object to be identified is a controlled object (e.g., a drone, a motor vehicle, or a non-motor vehicle). The device includes a time-coded metasurface and a control module. The control module is configured to design a time-coded metasurface based on a unique identification code assigned to the controlled object. The time-coded metasurface is configured to reflect electromagnetic waves emitted by an identification terminal and modulate the reflected echoes with different frequency offsets based on a sequence corresponding to the identification code, allowing the identification terminal to obtain the license plate information of the controlled object based on the reflected echoes.

[0100] In one embodiment, Figure 11As shown, an identity recognition system based on electromagnetic control is provided, comprising: an identity recognition device based on an electromagnetic control method for identity recognition, and an electromagnetic control device based on an electromagnetic control method for identity information;

[0101] The identity recognition device includes an electromagnetic wave transmitting device, an electromagnetic wave receiving device and an identification module; the electromagnetic wave transmitting device is used to transmit electromagnetic waves to the object to be identified; the electromagnetic wave receiving device is used to receive the echo reflected by the time-coding metasurface installed on the object to be identified; the time-coding metasurface is designed according to the identification code assigned to the object to be identified, and modulates the reflected echo with different frequency offsets based on the sequence corresponding to the identification code; the identification module is used to perform preliminary decoding on the received echo to obtain a sequence, locate the starting segment of the preset sequence, estimate the time delay difference between the metasurface time modulation and the transmitted signal based on the starting segment of the preset sequence, and perform frequency offset compensation on the echo signal in combination with the sequence and the time delay difference; and decode the identification code of the echo after frequency offset compensation to obtain the identity information of the object to be identified;

[0102] The electromagnetic control device includes a time-coding metasurface and a control module. The control module is used to design a time-coding metasurface according to a unique identification code assigned to the object to be identified. The time-coding metasurface is used to reflect the electromagnetic waves emitted by the identity recognition end and modulate different frequency deviations of the reflected echo based on the sequence corresponding to the identification code, so that the identity recognition end can obtain the identity information of the object to be identified based on the reflected echo.

[0103] In one embodiment, a computer system is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the computer program is executed by the processor, the steps of the aforementioned electromagnetic control-based identity recognition method are implemented.

[0104] In one embodiment, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the aforementioned electromagnetic control-based identity recognition method are implemented.

[0105] In one embodiment, a computer program product is provided, comprising a computer program, wherein when the computer program is executed by a processor, the steps of the aforementioned electromagnetic control-based identity recognition method are implemented.

[0106] The program code for implementing the inventive method can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device so that the program code, when executed by the processor or controller, causes the steps of the inventive method to be implemented. The program code can be executed entirely on the machine, partially on the machine, partially on the machine as an independent software package and partially on a remote machine, or completely on a remote machine or server. The present invention is not described in detail herein, and all of these are known techniques to those skilled in the art.

[0107] The foregoing is merely a preferred embodiment of the present invention. It should be noted that the present invention is described by way of certain embodiments. It is understood by those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. Furthermore, under the guidance of the present invention, these features and embodiments may be modified to suit specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are intended to be protected by the present invention.

Claims

1. An identity recognition method based on electromagnetic control, characterized in that: The following steps are involved: Transmitting electromagnetic waves toward an object to be identified and receiving an echo reflected by a time-coding metasurface mounted on the object to be identified; the time-coding metasurface is designed according to an identification code assigned to the object to be identified, and modulates the reflected echo with different frequency offsets based on a sequence corresponding to the identification code; The received echo is preliminarily decoded to obtain a sequence, and the starting segment of the preset sequence is located. Based on the starting segment of the preset sequence, the time delay difference between the metasurface time modulation and the transmitted signal is estimated, and the frequency offset of the echo signal is compensated by combining the sequence and the time delay difference. According to the modulation period of the time-coded metasurface, the echo signal is divided into a series of signal blocks, and the frequency offset compensation is performed on each echo signal block. If the frequency offset corresponding to the first half of the encoding of an echo signal block is f pre , the frequency deviation corresponding to the second half of the coding is f post , increase the frequency deviation by sampling point in the second half of the signal block ( f pre -f post ); The identification code is decoded on the echo after frequency offset compensation to obtain the identity information of the object to be identified.

2. The identity recognition method based on electromagnetic control according to claim 1, characterized in that: The received echo is preliminarily decoded to obtain a sequence, a sliding window is used to perform a sliding search on the echo, a signal frequency within each sliding window is obtained by Fourier transform, and a sequence corresponding to the modulation is determined according to the frequency deviation.

3. The identity recognition method based on electromagnetic control according to claim 2, characterized in that: In the estimation of the time delay difference between the metasurface time modulation and the transmitted signal, a sliding window is used to search the frequency spectrum corresponding to the starting segment of a preset sequence in the echo signal, and the time delay difference is estimated according to the frequency hopping position therein.

4. The identity recognition method based on electromagnetic control according to claim 1, characterized in that: The identification code decoding of the echo after frequency offset compensation includes: performing Fourier transform on each signal block, determining the frequency offset according to the peak position of the Fourier transform, and then judging the code corresponding to the signal block.

5. The identity recognition method based on electromagnetic control according to claim 1, characterized in that: Also includes: The frequency offset compensated echo and decoding results are used for ranging.

6. The identity recognition method based on electromagnetic control according to claim 5, characterized in that: The method of performing ranging using the echo after frequency offset compensation and the decoding result includes: determining a reference signal for each signal block based on the decoding result, correlating the reference signal of each signal block with the echo signal block after frequency offset compensation, determining a time delay based on a peak position of a correlation function, and converting the delay into a distance.

7. A method for electromagnetic control of identity information, characterized in that: The following steps are involved: Assign a unique identification code to the object to be identified as identity information; A time-coding metasurface installed on the object to be identified is designed based on the identification code. The time-coding metasurface reflects the electromagnetic waves emitted by the identification terminal and modulates the reflected echoes with different frequency offsets based on the sequence corresponding to the identification code, so that the identification terminal can obtain the identity information of the object to be identified based on the reflected echoes; The identification terminal obtains the identity information of the object to be identified based on the reflected echo, including: The received echo is preliminarily decoded to obtain a sequence, and the starting segment of the preset sequence is located. Based on the starting segment of the preset sequence, the time delay difference between the metasurface time modulation and the transmitted signal is estimated, and the frequency offset of the echo signal is compensated by combining the sequence and the time delay difference. According to the modulation period of the time-coded metasurface, the echo signal is divided into a series of signal blocks, and the frequency offset compensation is performed on each echo signal block. If the frequency offset corresponding to the first half of the encoding of an echo signal block is f pre , the frequency deviation corresponding to the second half of the coding is f post , increase the frequency deviation by sampling point in the second half of the signal block ( f pre -f post ); The identification code is decoded on the echo after frequency offset compensation to obtain the identity information of the object to be identified.

8. The electromagnetic control method of identity information according to claim 7, characterized in that: When designing a time-coded metasurface, a preset sequence starting segment is added to the beginning of the corresponding sequence of the identification code to find the sequence starting point. The preset sequence starting segment is a sequence with values ​​ranging from 0 to M-1, and the values ​​of two adjacent elements are different. M indicates that the sequence is an M-ary sequence.

9. The electromagnetic control method of identity information according to claim 7, characterized in that: The reflection coefficient of the time-coded metasurface varies periodically with time, and the frequency modulation strategy is as follows: ； in, t Indicates time, represents the phase component of the reflection coefficient, f 1 to f M is the frequency deviation that the metasurface modulates the reflected echo when corresponding to codes 0 to M-1, and M indicates that the sequence is an M-ary sequence.

10. An identity recognition device based on electromagnetic control, used to implement the identity recognition method based on electromagnetic control according to any one of claims 1 to 6, characterized in that: It includes an electromagnetic wave transmitting device, an electromagnetic wave receiving device and an identification module; The electromagnetic wave transmitting device is used to transmit electromagnetic waves to the object to be identified; The electromagnetic wave receiving device is used to receive the echo reflected by the time coding metasurface installed on the object to be identified; the time coding metasurface is designed according to the identification code assigned to the object to be identified, and modulates the reflected echo with different frequency offsets based on the sequence corresponding to the identification code; The identification module is used to perform preliminary decoding on the received echo to obtain a sequence, locate the starting segment of the preset sequence, estimate the time delay difference between the metasurface time modulation and the transmitted signal based on the starting segment of the preset sequence, and compensate the frequency offset of the echo signal in combination with the sequence and the time delay difference; and decode the identification code of the echo after frequency offset compensation to obtain the identity information of the object to be identified.

11. An electromagnetic control device for identity information, used to implement the electromagnetic control method for identity information according to any one of claims 7 to 9, characterized in that: The system comprises a time-coding metasurface and a control module. The control module is used to design a time-coding metasurface according to a unique identification code assigned to an object to be identified. The time-coding metasurface is used to reflect electromagnetic waves emitted by an identification terminal and modulate different frequency deviations of the reflected echo based on a sequence corresponding to the identification code, so that the identification terminal can obtain the identity information of the object to be identified based on the reflected echo.

12. An electromagnetic license plate, installed on a controlled object, characterized in that: The electromagnetic control device is implemented based on the identity information according to claim 11, wherein the object to be identified is a controlled object.

13. The electromagnetic license plate according to claim 12, characterized in that: The control objects are drones, motor vehicles, non-motor vehicles or ships.

14. An identity recognition system based on electromagnetic control, characterized in that: include: An identity recognition device for implementing the electromagnetic control-based identity recognition method according to any one of claims 1 to 6, and an electromagnetic control device for implementing the electromagnetic control method for identity information according to any one of claims 7 to 9; The identity recognition device includes an electromagnetic wave transmitting device, an electromagnetic wave receiving device and an identification module; the electromagnetic wave transmitting device is used to transmit electromagnetic waves to the object to be identified; The electromagnetic wave receiving device is used to receive an echo reflected by a time-coding metasurface installed on an object to be identified; the time-coding metasurface is designed according to an identification code assigned to the object to be identified, and modulates the reflected echo with different frequency offsets based on a sequence corresponding to the identification code; the identification module is used to perform preliminary decoding on the received echo to obtain a sequence, locate a starting segment of a preset sequence, estimate the time delay difference between the metasurface time modulation and the transmitted signal based on the starting segment of the preset sequence, and perform frequency offset compensation on the echo signal in combination with the sequence and the time delay difference; and decode the identification code on the echo after frequency offset compensation to obtain the identity information of the object to be identified; The electromagnetic control device includes a time-coding metasurface and a control module. The control module is used to design a time-coding metasurface according to a unique identification code assigned to the object to be identified. The time-coding metasurface is used to reflect the electromagnetic waves emitted by the identity recognition end and modulate different frequency deviations of the reflected echo based on the sequence corresponding to the identification code, so that the identity recognition end can obtain the identity information of the object to be identified based on the reflected echo.

15. A computer system comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the computer program is executed by a processor, the steps of the electromagnetic control-based identity recognition method according to any one of claims 1 to 6 are implemented.

16. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the electromagnetic control-based identity recognition method according to any one of claims 1 to 6 are implemented.

17. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the electromagnetic control-based identity recognition method according to any one of claims 1 to 6 are implemented.

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