An emergency rescue vehicle-mounted imaging system based on time-frequency transfer technology

Abstract

The application belongs to the field of microwave communication and sensing, and discloses an emergency disaster relief vehicle-mounted imaging system based on time-frequency transmission technology, and particularly relates to an antenna communication system based on time-frequency transmission technology and a precision enhanced vehicle-mounted radar imaging system for emergency disaster relief combining time-frequency transmission technology and through-wall radar. The emergency disaster relief vehicle-mounted imaging system comprises an information transmission radar antenna system, a ranging system, a detection system, an atomic clock and a microcomputer. The application aims to provide an emergency disaster relief vehicle-mounted imaging system which can be interconnected at multiple points and has more accurate three-dimensional stereoscopic imaging, so as to provide faster and more accurate detection data for emergency disaster relief and realize the function of mutual accurate time communication. The application can provide support for detecting the environment and determining the position of human bodies for operating personnel, and increase the safety factor and operating efficiency.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of microwave communication, and particularly relates to an antenna communication system based on time-frequency transmission technology and a precision enhanced vehicle-mounted radar imaging system for emergency rescue combined with time-frequency transmission technology and a through-wall radar. BACKGROUND

[0002] Human life is more important than heaven, and the speed and effect of emergency rescue have always been an important guarantee for the safety of people's lives and property. With the development of science and technology this year, accurate and timely scene maps will provide better working conditions, especially for places that cannot be seen by the naked eye and cannot be remotely measured by satellites. Therefore, the scientific community has begun to study the function of through-wall radar, which can only detect the inside of the shelter, making the efficiency of emergency rescue progress again.

[0003] The current panoramic area imaging system mostly adopts a single imaging mechanism. Since micro-Doppler signals exist widely in reality, the imaging effect is slightly insufficient and difficult to improve. The online imaging interaction also has problems of high packet loss rate, bit error rate and information time inconsistency due to poor time accuracy of high-speed data transmission. The connection of time-frequency transmission technology to this system can greatly improve the imaging accuracy.

[0004] In the current area surface imaging technology, including laser imaging, microwave imaging, ultrasonic imaging, panoramic optical probe detection and various technologies, and its technology is relatively mature. The through-wall detection technology for object internal detection only includes laser radar and microwave radar. The use environment of laser radar is harsh, and it is not suitable for complex and variable emergency rescue environment detection. Therefore, improving the through-wall detection performance of microwave through-wall radar becomes the first choice.

[0005] The through-wall radar receives the transmitted microwave signal due to the imaging mechanism. The through-wall radar uses lower frequency electromagnetic waves as detection signals, which will cause low resolution performance of micro-Doppler. Therefore, its accuracy always has room for improvement. The current through-wall detection technology mainly transmits a certain frequency of microwave and receives it, then performs signal demodulation processing, and then uses a mature trained algorithm to solve, obtains the final imaging result and displays it. It involves antenna direct coupling wave, direct reflection of shelter surface, reflection of multi-layer shelter, target background clutter reflection, electromagnetic noise of free space, etc. In these many interference factors, each accurate measurement can significantly improve the final detection performance. SUMMARY

[0006] The purpose of the present application is to provide a multi-point interconnected, three-dimensional imaging more accurate emergency rescue vehicle-mounted imaging system, which can provide faster and more accurate detection data for emergency rescue and mutual timely communication function.

[0007] The technical scheme adopted by the present application is:

[0008] An emergency rescue vehicle imaging system based on time-frequency transmission technology, comprising an information transmission radar antenna system, a ranging system, a through-wall radar detection system, an atomic clock and a microcomputer;

[0009] The atomic clock is used to generate a 1PPS signal and a 10MHz frequency signal, which are provided to the information transmission radar antenna system, the ranging system and the through-wall radar detection system;

[0010] The information transmission radar antenna system is used to generate a communication signal under the control of the microcomputer with the atomic clock 10MHz frequency signal as the local oscillator, to send real-time detection signals to the outside world, to complete information interconnection with other detection units or the total station in the outside world; and to receive communication signals of other detection units or the total station in the outside world, and to transmit the communication signals to the microcomputer after compensation for the delay of the communication signals by using time-frequency synchronization technology;

[0011] The ranging system is used for measuring the shape of the surface of a remote obstacle, to emit the 1PPS signal and the 10MHz frequency signal generated by the atomic clock, to receive the 1PPS signal and the 10MHz frequency signal reflected by the surface of the obstacle, to measure the time difference between the received signal and the signal generated by the atomic clock, and to transmit the time delay information to the microcomputer;

[0012] The through-wall radar detection system is used for measuring the internal shape of a remote obstacle, to emit the 1PPS signal and the 10MHz frequency signal generated by the atomic clock through a phase discriminator, a loop filter and a phase shifter to form a phase-locked loop, and to perform analog-to-digital conversion on the detection signal and the transmission signal synchronously and transmit them to the microcomputer;

[0013] The microcomputer is used to extract features from the detection signal, the time delay information and the communication signal of other detection units or the total station in the outside world, to generate various detection results, to apply models and cross-cover models, and to eliminate incorrect models; it is also used to receive the motion condition of a detection target provided by artificial information, to load a deep convolutional neural network micro-Doppler model if the detection target is in motion, and to receive the base information of the detection antenna and the communication antenna to obtain the detection direction positioning; then, a three-dimensional matrix is generated by using the retained models after elimination, the deep convolutional neural network micro-Doppler model and the detection direction positioning, and a signal generator is controlled.

[0014] Further, the information transmission radar antenna system comprises a signal generator, a first power amplifier, a first time interval and phase difference measurement module, a control unit, a first phase shifter, a first AD converter, a communication antenna, a first low-noise amplifier, a second power amplifier, a power divider and a first 10M filter;

[0015] The signal generator generates a communication signal under the control of the microcomputer using the 1PPS signal and the 10MHz frequency signal generated by the atomic clock, and sends the signal out through the communication antenna after amplification by the first power amplifier; the communication antenna receives the communication signal of other detection units or the main station, and sequentially outputs the signal to the power divider through the first low-noise amplifier and the second power amplifier; the power divider divides the signal into three paths, one path filters out the 10MHz signal output to the first time interval and phase difference measurement module through the first 10M filter, one path is directly output to the first time interval and phase difference measurement module, and one path is output to the phase shifter; the first time interval and phase difference measurement module measures the time interval of the 1PPS signal directly output by the power divider and the 1PPS signal generated by the atomic clock, measures the phase difference of the 10MHz frequency signal output by the first 10M filter and the 10MHz frequency signal generated by the atomic clock, and transmits the time interval and phase difference information to the control unit; the control unit processes the time interval and phase difference information to obtain accurate time delay information, and controls the delay of the signal output by the power divider through the first phase shifter to realize time-frequency synchronization, and then converts the processed communication signal into a digital signal through the first AD converter and transmits the digital signal to the microcomputer.

[0016] Further, the distance measuring system comprises a second time interval and phase difference measurement module, a second 10M filter, a third power amplifier, a fourth power amplifier, a second low-noise amplifier and a detection antenna.

[0017] The fourth power amplifier enhances the 1PPS signal and the 10MHz frequency signal generated by the atomic clock, and transmits the signals through the detection antenna; the signals reflected by the surface of the obstacle are received by the detection antenna and sequentially amplified by the second low-noise amplifier and the third power amplifier; the third power amplifier directly outputs the 1PPS signal to the second time interval and phase difference measurement module, and filters out the 10MHz signal output to the second time interval and phase difference measurement module through the second 10M filter; the second time interval and phase difference measurement module measures the time interval of the 1PPS signal output by the third power amplifier and the 1PPS signal generated by the atomic clock, and measures the phase difference of the 10MHz frequency signal of the second 10M filter and the 10MHz frequency signal generated by the atomic clock to obtain accurate time interval and transmit the time interval to the microcomputer.

[0018] Further, the through-wall radar detection system comprises a phase detector, a loop filter, a second phase shifter, a fifth power amplifier, a second AD converter, a third power amplifier, a second low-noise amplifier and a detection antenna.

[0019] The local oscillator signal emitted by the atomic clock is phase-stabilized under the action of the phase-locked loop formed by the phase detector, the loop filter and the second phase shifter, and is enhanced by the fifth power amplifier, and then is transmitted through the detection antenna.

[0020] The inside and outside obstacle surface reflection signals are received by the detection antenna, and are sequentially amplified by the second low-noise amplifier and the third power amplifier, the received detection signals and the transmission signals of the detection antenna are converted into digital signals by the second AD converter, and are transmitted to the microcomputer.

[0021] Compared with the prior art, the present application has the following advantages:

[0022] The current detection imaging system has a single principle and a high detection error probability, the system of the present application effectively improves the detection accuracy by using the inside and outside obstacle surface detection mode, and further improves the accuracy by using the advantages of artificial auxiliary qualitative detection, accurate detection direction measurement and multi-machine interconnection fusion processing, converts the traditional two-dimensional detection into three-dimensional detection imaging, effectively improves the multi-machine group operation capability, and has significant advantages in the application background of emergency rescue and other applications with high requirements for real-time and accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The figure is a schematic diagram of the information transmission radar antenna system of the present application.

[0024] Figure 2 The figure is a schematic diagram of the ranging system of the present application.

[0025] Figure 3 The figure is a schematic diagram of the wall-penetrating radar detection system of the present application.

[0026] Figure 4 The figure is a schematic diagram of the emergency rescue vehicle-mounted imaging system of the present application.

[0027] Figure 5 The figure is a flow chart of the microcomputer terminal data processing. DETAILED DESCRIPTION

[0028] The present application will be further described below in combination with the accompanying drawings and specific preferred embodiments, so that those skilled in the art can better understand the present application. It should be particularly noted that in the following description, when the detailed description of known functions and designs may obscure the main content of the present application, these descriptions will be omitted here.

[0029] An emergency rescue vehicle-mounted imaging system based on time-frequency transmission technology, comprising an information transmission radar antenna system, a ranging system, a wall-penetrating radar detection system, an atomic clock and a microcomputer;

[0030] The atomic clock is used to generate a 1PPS signal and a 10MHz frequency signal, and is provided to the information transmission radar antenna system, the ranging system and the detection system;

[0031] The information transmission radar antenna system is used for generating a communication signal under the control of a microcomputer with an atomic clock 10MHz frequency signal as a local oscillator, sending a real-time detection signal to the outside world, completing information interconnection with other detection units or a total station in the outside world, receiving a communication signal of other detection units or the total station in the outside world, and transmitting the communication signal to the microcomputer after compensation of the communication signal delay by using a time frequency synchronization technology;

[0032] The distance measurement system is used for measuring the surface shape of a remote obstacle, emits a 1PPS signal and a 10MHz frequency signal generated by an atomic clock, receives a 1PPS signal and a 10MHz frequency signal reflected by the surface of the obstacle, measures the time difference between the received signal and the signal generated by the atomic clock to obtain time delay information, and transmits the time delay information to the microcomputer;

[0033] The through-wall radar detection system is used for measuring the internal shape of a remote obstacle, emits a 1PPS signal and a 10MHz frequency signal generated by an atomic clock through a phase discriminator, a loop filter and a phase shifter to form a phase-locked loop, and synchronously performs analog-to-digital conversion on the detection signal and the transmission signal and transmits the converted signal to the microcomputer;

[0034] The microcomputer is used for extracting features of the detection signal, the time delay information and the communication signal of other detection units or the total station in the outside world, generating various detection results, applying and crossing covering models, and eliminating incorrect models, receiving motion information of a detection target provided by artificial information, loading a deep convolutional neural network micro-Doppler model if the detection target is in motion, receiving base information of a detection antenna and a communication antenna to obtain a detection direction position, generating a three-dimensional matrix through the retained models after elimination, the deep convolutional neural network micro-Doppler model and the detection direction position, and controlling a signal generator.

[0035] Figure 1 The information transmission radar antenna system is used for generating a communication signal under the control of a microcomputer with an atomic clock 10MHz frequency signal as a local oscillator, sending a real-time detection signal to the outside world, completing information interconnection with other detection units or a total station in the outside world, receiving a communication signal of other detection units or the total station in the outside world, and transmitting the communication signal to the microcomputer after compensation of the communication signal delay by using a time frequency synchronization technology;

[0036] The signal generator generates a communication signal by using the 1PPS signal and the 10MHz frequency signal generated by the atomic clock under the control of the microcomputer, and sends the signal out through the communication antenna after amplification by the first power amplifier; the communication antenna receives the communication signal of other detection units or the total station in the outside world, and sequentially outputs the signal to the power divider through the first low-noise amplifier and the second power amplifier; the power divider divides the signal into three paths, one path filters out the 10MHz signal output to the first time interval and phase difference measurement module through the first 10M filter, one path is directly output to the first time interval and phase difference measurement module, and one path is output to the phase shifter; the first time interval and phase difference measurement module measures the time interval of the 1PPS signal directly output by the power divider and the 1PPS signal generated by the atomic clock, measures the phase difference of the 10MHz frequency signal output by the first 10M filter and the 10MHz frequency signal generated by the atomic clock, and transmits the time interval and phase difference information to the control unit; the control unit is based on the RS232 single-chip microcomputer development board, has the functions of data collection, processing and instruction output which have been successfully downloaded, obtains accurate time delay information by processing the time interval and phase difference information, and controls the delay of the signal output by the power divider through the first phase shifter, realizes time-frequency synchronization, and then converts the processed communication signal into a digital signal through the first AD converter and transmits the digital signal to the microcomputer.

[0037] Figure 2 The principle diagram of the distance measuring system is shown in the figure. The distance measuring system comprises a second time interval and phase difference measurement module, a second 10M filter, a third power amplifier, a fourth power amplifier, a second low-noise amplifier and a detection antenna.

[0038] The fourth power amplifier enhances the 1PPS signal and the 10MHz frequency signal generated by the atomic clock, and transmits the signals through the detection antenna; the signals reflected by the surface of the obstacle are received by the detection antenna, and are sequentially amplified by the second low-noise amplifier and the third power amplifier; the third power amplifier directly outputs the 1PPS signal to the second time interval and phase difference measurement module, and filters out the 10MHz signal from the signal through the second 10M filter and outputs the signal to the second time interval and phase difference measurement module; the second time interval and phase difference measurement module measures the time interval of the 1PPS signal output by the third power amplifier and the 1PPS signal generated by the atomic clock, measures the phase difference of the 10MHz frequency signal of the second 10M filter and the 10MHz frequency signal generated by the atomic clock, and transmits the accurate time interval to the microcomputer.

[0039] Figure 3 The principle diagram of the wall-penetrating radar detection system is shown in the figure. The detection system comprises a phase detector, a loop filter, a second phase shifter, a fifth power amplifier, a second AD converter, a third power amplifier, a second low-noise amplifier and a detection antenna.

[0040] The local oscillator signal emitted by the atomic clock is stabilized in phase under the action of a phase-locked loop formed by a phase discriminator, a loop filter and a second phase shifter, and is enhanced in signal by a fifth power amplifier, and then is emitted by a probe antenna;

[0041] The inside and outside surface reflection signals of the obstacle are received by the probe antenna, and are sequentially amplified twice by a second low-noise amplifier and a third power amplifier, the received probe signals and the emitted signals of the probe antenna are collectively subjected to analog-to-digital conversion by a second AD converter, and are transmitted to a microcomputer.

[0042] Figure 4 It is a total schematic view of the emergency rescue vehicle-mounted imaging system in the application.

[0043] Among them, each subsystem shares the same atomic clock, and the atomic clock can have multiple signal output ports, or a power divider can be used to provide signals for each subsystem.

[0044] Among them, each subsystem shares the same microcomputer terminal, which processes the signals received by all subsystems.

[0045] Among them, the ranging system and the through-wall radar detection system use the same antenna to send signals and receive echoes.

[0046] Among them, the ranging system and the through-wall radar detection system are arranged one above the other on the two layers of the double-layer lifting platform, each has a rotating function and can send the rotating and tilting angle parameters to the microcomputer terminal.

[0047] Figure 5 It is a flow chart of the microcomputer terminal data processing in the application.

[0048] Among them, the data involved in the processing flow are the previous frame data and the current frame data, the collected information is the echo information generated by the through-wall radar detection system in the frame, the base station attitude information and the time-frequency ranging information.

[0049] Among them, for the previous frame data, the echo information generated by the through-wall radar detection system generates an echo matrix under the reference of the base station attitude information, and the time-frequency ranging information generates an information matrix of the detection area surface information under the reference of the base station attitude information, then the sub-matrix representing the detection area surface information in the echo matrix is replaced by the information matrix of the detection area surface information converted by the time-frequency ranging information, then the data is imported, and after the eigenvalue extraction, it is fitted into the trained analysis model to generate multiple sets of possible imaging matrix models.

[0050] Among them, the microcomputer terminal can manually input the detection indicators: whether it is a multi-layer irregular shelter, whether there is a possibility of movement in the detection target, and the capture demand of the moving target.

[0051] Wherein for the frame data, the echo information generated by the through-wall radar detection system generates an echo matrix under the reference of the base station attitude information, and the time-frequency ranging information generates an information matrix of the detection area surface information under the reference of the base station attitude information, then the sub-matrix representing the detection area surface information in the echo matrix is replaced by the information matrix of the detection area surface information converted by the time-frequency ranging information, then data import is carried out, and after eigenvalue extraction, it is fitted into the trained analysis model to generate a plurality of groups of possibility imaging matrix models. Then use this model and the matrix model generated by the previous frame data to carry out fuzzy cross coverage, define the model with too high deviation degree as an error model and put it into the standby area, store the remaining model, and call the stored model according to the driving speed of the vehicle to judge the previous seconds again Cross coverage, the similarity threshold value is gradually reduced according to the time amount of the called model, the error model is deleted, then the motion of the target is referred to, the information output from the total station is added, and a three-dimensional imaging matrix is generated, and finally the panoramic imaging result of the detection area is output.

[0052] The transceiving antenna used by the through-wall radar detection system includes but is not limited to a single base station method in a shared state, and also includes a double base station method with transceiving antennas separated.

[0053] The method of reducing data processing difficulty by mixing the antenna receiving signal with the local oscillator signal through the mixer to obtain a lower frequency intermediate frequency signal is covered in the present application.

[0054] When processing the target motion information, the model used includes but is not limited to a deep convolutional neural network micro-Doppler model.

[0055] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An emergency rescue vehicle-mounted imaging system based on time-frequency transfer technology, characterized in that, The system comprises an information transmission radar antenna system, a ranging system, a through-wall radar detection system, an atomic clock and a microcomputer. The atomic clock is used to generate a 1PPS signal and a 10MHz frequency signal, which are provided to the information transmission radar antenna system, the ranging system and the through-wall radar detection system. The information transmission radar antenna system is used to generate a communication signal under the control of the microcomputer, using the 10MHz frequency signal of the atomic clock as a local oscillator, to send a real-time detection signal to the outside world, complete information interconnection with other detection units or a total station in the outside world, receive a communication signal from other detection units or the total station in the outside world, and transmit the signal to the microcomputer after compensation for the delay of the signal by time-frequency synchronization technology. The ranging system is used to measure the shape of a remote obstacle, transmit the 1PPS signal and the 10MHz frequency signal generated by the atomic clock, receive the 1PPS signal and the 10MHz frequency signal reflected by the surface of the obstacle, measure the time difference between the received signal and the signal generated by the atomic clock, and transmit the time delay information to the microcomputer. The through-wall radar detection system is used to measure the shape of the inside of a remote obstacle, transmit the 1PPS signal and the 10MHz frequency signal generated by the atomic clock through a phase discriminator, a loop filter and a phase shifter to form a phase-locked loop, and perform analog-to-digital conversion on the detection signal and the transmission signal synchronously and transmit the converted signal to the microcomputer. The microcomputer is used to extract features from the detection signal, the time delay information and the communication signal from other detection units or the total station, generate various detection results, apply and cross-cover models, and eliminate incorrect models. The microcomputer is also used to receive the movement of a detection target provided by artificial information, load a deep convolutional neural network micro-Doppler model if the detection target is moving, receive base information of a detection antenna and a communication antenna to obtain a detection direction, generate a three-dimensional matrix through the retained models after elimination, the deep convolutional neural network micro-Doppler model and the detection direction, and control a signal generator.

2. The emergency rescue vehicle-mounted imaging system based on time-frequency transfer technology according to claim 1, characterized in that, The information transmission radar antenna system comprises a signal generator, a first power amplifier, a first time interval and phase difference measurement module, a control unit, a first phase shifter, a first AD converter, a communication antenna, a first low-noise amplifier, a second power amplifier, a power divider and a first 10M filter. The signal generator generates a communication signal using the 1PPS signal and the 10MHz frequency signal generated by the atomic clock under the control of the microcomputer, and sends the signal out through the communication antenna after amplification by the first power amplifier. The communication antenna receives the communication signal of other detection units or the total station, and sequentially outputs the signal to the power divider through the first low-noise amplifier and the second power amplifier; the power divider divides the signal into three paths, one path filters out the 10MHz signal through the first 10M filter and outputs the signal to the first time interval and phase difference measurement module, one path directly outputs the signal to the first time interval and phase difference measurement module, and one path outputs the signal to the phase shifter; the first time interval and phase difference measurement module measures the time interval between the 1PPS signal directly output by the power divider and the 1PPS signal generated by the atomic clock, measures the phase difference between the 10MHz frequency signal output by the first 10M filter and the 10MHz frequency signal generated by the atomic clock, and transmits the time interval and phase difference information to the control unit; the control unit processes the time interval and phase difference information to obtain accurate time delay information, controls the signal output by the power divider through the first phase shifter, realizes time-frequency synchronization, and then converts the processed communication signal into a digital signal through the first AD converter and transmits the digital signal to the microcomputer.

3. The emergency rescue vehicle-mounted imaging system based on time-frequency transfer technology according to claim 1, characterized in that, The distance measurement system comprises a second time interval and phase difference measurement module, a second 10M filter, a third power amplifier, a fourth power amplifier, a second low-noise amplifier and a detection antenna; The fourth power amplifier enhances the 1PPS signal and the 10MHz frequency signal generated by the atomic clock, and transmits the signals through the detection antenna; the signals reflected by the surface of the obstacle are received by the detection antenna, and are sequentially amplified by the second low-noise amplifier and the third power amplifier; the third power amplifier directly outputs the 1PPS signal to the second time interval and phase difference measurement module, and filters out the 10MHz signal through the second 10M filter and outputs the signal to the second time interval and phase difference measurement module; the second time interval and phase difference measurement module measures the time interval between the 1PPS signal output by the third power amplifier and the 1PPS signal generated by the atomic clock, measures the phase difference between the 10MHz frequency signal of the second 10M filter and the 10MHz frequency signal generated by the atomic clock, and transmits the accurate time interval to the microcomputer.

4. The emergency rescue vehicle-mounted imaging system based on time-frequency transfer technology according to claim 1, characterized in that, The through-wall radar detection system comprises a phase detector, a loop filter, a second phase shifter, a fifth power amplifier, a second AD converter, a third power amplifier, a second low-noise amplifier and a detection antenna; The local oscillator signal emitted by the atomic clock is phase-stabilized under the action of the phase-locked loop formed by the phase detector, the loop filter and the second phase shifter, and is enhanced through the fifth power amplifier, and then is transmitted through the detection antenna; The reflected signals inside and outside the obstacle are received by the detection antenna, and are sequentially amplified by the second low-noise amplifier and the third power amplifier, and the received detection signals and the transmitted signals of the detection antenna are collectively converted into digital signals through the second AD converter and are transmitted to the microcomputer.

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