Emergency relief vehicle-mounted imaging system based on time-frequency transmission technology

Abstract

The invention belongs to the field of microwave inductance, discloses an emergency disaster relief vehicle-mounted imaging system based on a time-frequency transmission technology, and particularly relates to an antenna communication system based on the time-frequency transmission technology and a precision enhanced vehicle-mounted radar imaging system which combines the time-frequency transmission technology and a through-the-wall radar and is used for emergency disaster relief. The emergency disaster relief vehicle-mounted imaging system comprises an information transmission radar antenna system, a distance measuring system, a detection system, an atomic clock and a microcomputer. The invention aims to provide the emergency disaster relief vehicle-mounted imaging system which can realize multi-point interconnection and is more accurate in three-dimensional imaging, and the functions of providing faster and more accurate detection data and mutual punctual communication for emergency disaster relief are achieved. Support can be provided for operators to detect the environment and determine the direction of the human body, and the safety coefficient and the operation efficiency are improved.

Description

Technical Field

[0001] The present invention belongs to the field of microwave remote sensing, and specifically relates to an antenna communication system based on time-frequency transfer technology and a precision-enhanced vehicle-mounted radar imaging system for emergency rescue that combines time-frequency transfer technology and through-wall radar. Background Art

[0002] Human life is of utmost importance. The speed and effectiveness of emergency rescue have always been important guarantees for people's lives and property safety. With the development of technology in recent years, accurate and timely scene maps will provide better operating conditions, especially in places that are invisible to the naked eye and cannot be remotely sensed by satellites. Therefore, the scientific community has begun to study the function of through-wall radar, which can only detect the inside of shelters, further improving the efficiency of emergency rescue.

[0003] Currently, most panoramic area imaging systems adopt a single-machine imaging mechanism. Since micro-Doppler signals widely exist in reality, the imaging effect is slightly insufficient and difficult to improve. The online imaging interaction has problems such as a large packet loss rate, error rate, and information time mismatch due to poor time accuracy, and integrating time-frequency transfer technology into this system will greatly improve the imaging accuracy.

[0004] Current area surface imaging technologies include laser imaging, microwave imaging, ultrasonic imaging, panoramic optical probe detection, etc., and these technologies are relatively mature; for through-wall detection technology for detecting the inside of objects, there are only lidar and microwave radar. Among them, the use environment of lidar is harsh and not suitable for detecting in complex and changeable emergency rescue environments. Therefore, improving the through-wall detection performance of microwave through-wall radar has become the primary choice.

[0005] Since the imaging mechanism of through-wall radar is to receive the emitted microwave signals, through-wall radar uses lower-frequency electromagnetic waves as detection signals, which leads to the low-resolution performance of micro-Doppler. Therefore, there is always room for improvement in its accuracy. Currently, most through-wall detection technologies emit a certain frequency of microwave and receive it, then perform signal demodulation processing and use a well-trained algorithm for calculation to obtain the final imaging result and display it. This involves antenna direct coupling waves, direct reflections on the surface of shelters, reflections from multiple layers of shelters, clutter reflections from the target background, electromagnetic noise in free space, etc. Among these numerous interference factors, accurately measuring each one can significantly improve the final detection performance. Summary of the Invention

[0006] The purpose of the present invention is to provide an emergency rescue vehicle-mounted imaging system that can be interconnected at multiple points and has more accurate three-dimensional stereoscopic imaging, achieving the functions of providing faster and more accurate detection data for emergency rescue and mutual timely communication.

[0007] The technical solution adopted by the present invention is as follows:

[0008] An emergency disaster relief vehicle-mounted imaging system based on time-frequency transfer 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, and supply them 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 with the 10MHz frequency signal of the atomic clock as the local oscillator under the control of the microcomputer, send real-time detection signals to the outside world, and complete information interconnection with other detection units or the main station outside; and receive communication signals from other detection units or the main station outside, and use time-frequency synchronization technology to compensate for the delay of the communication signals and then transmit them to the microcomputer;

[0011] The ranging system is used for measuring the surface morphology of distal obstacle objects, transmitting the 1PPS signal and the 10MHz frequency signal generated by the atomic clock, and receiving the 1PPS signal and the 10MHz frequency signal reflected from the surface of the obstacle, measuring the time difference between the received signal and the signal generated by the atomic clock, and transmitting the obtained time delay information to the microcomputer;

[0012] The through-wall radar detection system is used for measuring the internal morphology of distal obstacles. It transmits the 1PPS signal and the 10MHz frequency signal generated by the atomic clock through a phase-locked loop composed of a phase discriminator, a loop filter and a phase shifter, and synchronously performs analog-to-digital conversion on the detection signal and the transmitted signal, and transmits it to the microcomputer;

[0013] The microcomputer is used for extracting the characteristics of the detection signal, the time delay information and the communication signals from other detection units or the main station outside, generating various detection results, performing model application and model cross-coverage, and eliminating incorrect models; it is also used for receiving the motion situation of the detection target provided by artificial information. If the detection target is in a motion situation, it loads a deep convolutional neural network micro-Doppler model; and receives the base information of the detection antenna and the communication antenna to obtain the detection direction positioning; then generates a three-dimensional matrix through the remaining models after elimination, the deep convolutional neural network micro-Doppler model and the detection direction positioning, and controls the signal generator.

[0014] Further, the information transmission radar antenna system includes 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] Under the control of the microcomputer, the signal generator generates communication signals using the 1PPS signal and the 10MHz frequency signal generated by the atomic clock. After being amplified by the first power amplifier, the signals are sent out through the communication antenna. The communication antenna receives communication signals from other external detection units or the master station, and outputs them to the power divider through the first low-noise amplifier and the second power amplifier in sequence. The power divider divides the signal into three paths. One path filters out the 10MHz signal through the first 10M filter and outputs it to the first time interval and phase difference measurement module. One path is directly output to the first time interval and phase difference measurement module. One path is output 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, and controls the delay of the signal output by the power divider by controlling the first phase shifter to achieve time-frequency synchronization. Then, the processed communication signal is converted into a digital signal by the first AD converter and transmitted to the microcomputer.

[0016] Further, the ranging system includes 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 them through the detection antenna. The signal reflected from the surface of the obstacle is received by the detection antenna and is amplified twice through the second low-noise amplifier and the third power amplifier in sequence. 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 it 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.

[0018] Further, the through-wall radar detection system includes a phase discriminator, 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 jointly formed by the phase discriminator, the loop filter, and the second phase shifter, and the signal is enhanced by the fifth power amplifier and then transmitted through the detection antenna;

[0020] The reflected signals on the inner and outer surfaces of the obstacle are received by the detection antenna, and are amplified in two stages by the second low-noise amplifier and the third power amplifier in sequence. The received detection signal and the transmitted signal of the detection antenna are jointly subjected to analog-to-digital conversion by the second AD converter and then transmitted to the microcomputer.

[0021] The advantages of the present invention compared with the prior art are as follows:

[0022] The principle of the current detection and imaging system is single, and it has a high probability of detection error. The system of the present invention effectively improves the detection accuracy by using the method of separately detecting the surface and the interior of the obstacle, and further improves the accuracy by taking advantage of the advantages of artificial auxiliary qualitative analysis, precise measurement of the detection direction, and multi-machine interconnected fusion processing. It converts the traditional two-dimensional detection into three-dimensional detection and imaging, effectively improves the multi-machine cluster cooperation ability, and has significant advantages in application backgrounds with high requirements for real-time performance and accuracy such as emergency disaster relief. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the principle of the information transmission radar antenna system of the present invention.

[0024] Figure 2 It is a schematic diagram of the principle of the ranging system of the present invention.

[0025] Figure 3 It is a schematic diagram of the principle of the through-wall radar detection system of the present invention.

[0026] Figure 4 It is a general schematic diagram of the emergency disaster relief vehicle-mounted imaging system of the present invention.

[0027] Figure 5 It is a flowchart of the data processing of the microcomputer terminal. DETAILED DESCRIPTION OF THE EMBODIMENTS

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

[0029] An emergency disaster relief vehicle-mounted imaging system based on time-frequency transfer technology includes an information transmission radar antenna system, a ranging system, a through-wall 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 supply them to the information transmission radar antenna system, the ranging system, and the detection system;

[0031] The information transmission radar antenna system is used to generate communication signals with the 10 MHz frequency signal of the atomic clock as the local oscillator under the control of a microcomputer, send real-time detection signals to the outside world, and complete information interconnection with other detection units or the main station outside; and receive communication signals from other detection units or the main station outside, and transmit them to the microcomputer after compensating for the communication signal delay using time-frequency synchronization technology;

[0032] The ranging system is used for the surface morphology measurement of distal obstacle objects, emits the 1PPS signal and the 10 MHz frequency signal generated by the atomic clock, and receives the 1PPS signal and the 10 MHz frequency signal reflected from the obstacle surface, measures the time difference between the received signal and the signal generated by the atomic clock, and transmits the obtained time delay information to the microcomputer;

[0033] The through-wall radar detection system is used for the internal morphology measurement of distal obstacles. It emits the 1PPS signal and the 10 MHz frequency signal generated by the atomic clock through a phase-locked loop composed of a phase discriminator, a loop filter, and a phase shifter, and synchronizes the detection signal with the transmitted signal for analog-to-digital conversion and transmits it to the microcomputer;

[0034] The microcomputer is used to extract the features of the detection signal, time delay information, and communication signals from other detection units or the main station outside, generate various detection results, perform model application and model cross-coverage, and eliminate incorrect models; it is also used to receive the motion status of the detection target provided by manual information. If the detection target is in motion, it loads the deep convolutional neural network micro-Doppler model; and receives the base information of the detection antenna and the communication antenna to obtain the detection direction positioning; then generates a three-dimensional matrix through the remaining models after elimination, the deep convolutional neural network micro-Doppler model, and the detection direction positioning to control the signal generator.

[0035] Figure 1 This is a schematic diagram of the principle of the information transmission radar antenna system of the present invention. The information transmission radar antenna system includes 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;

[0036] Under the control of a microcomputer, the signal generator generates a communication signal using the 1PPS signal and the 10MHz frequency signal generated by the atomic clock. After being amplified by the first power amplifier, it is sent out through the communication antenna. The communication antenna receives communication signals from other external detection units or the master station, and outputs them to the power divider through the first low-noise amplifier and the second power amplifier in sequence. The power divider divides the signal into three paths. One path filters out the 10MHz signal through the first 10M filter and outputs it to the first time interval and phase difference measurement module, 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 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 is based on the RS232 single-chip microcomputer development board, which has the functions of successfully downloaded data collection, processing, and instruction output. The control unit processes the time interval and phase difference information to obtain accurate delay information, and controls the delay of the signal output by the power divider by controlling the first phase shifter to achieve time-frequency synchronization. Then, the processed communication signal is converted into a digital signal through the first AD converter and transmitted to the microcomputer.

[0037] Figure 2 This is a schematic diagram of the principle of the ranging system of the present invention. The ranging system includes 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 them through the detection antenna. The signal reflected from the surface of the obstacle is received by the detection antenna and is amplified twice through the second low-noise amplifier and the third power amplifier in sequence. 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 it 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.

[0039] Figure 3 This is a schematic diagram of the principle of the through-wall radar detection system of the present invention. The detection system includes a phase discriminator, 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 phase-stabilized under the action of the phase-locked loop formed by the phase detector, loop filter, and second phase shifter, and is amplified by the fifth power amplifier, and then transmitted through the detection antenna;

[0041] The signals reflected from the inside and outside of the obstacle are received by the detection antenna, and are amplified in two stages by the second low-noise amplifier and the third power amplifier in sequence. The received detection signal and the transmitted signal of the detection antenna are jointly subjected to analog-to-digital conversion by the second AD converter and then transmitted to the microcomputer.

[0042] Figure 4 It is the overall schematic diagram of the on-vehicle imaging system for emergency disaster relief in the present invention.

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

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

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

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

[0047] Figure 5 It is the flow chart of data processing by the microcomputer terminal in the present invention.

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

[0049] Among them, for the previous frame data, the echo information generated by the through-wall radar detection system generates an echo matrix with reference to the base attitude information. At the same time, the time-frequency ranging information generates an information matrix of the surface information of the detection area with reference to the base attitude information. Subsequently, the sub-matrix representing the surface information of the detection area in the echo matrix is replaced by the information matrix of the surface information of the detection area converted by the time-frequency ranging information. Subsequently, data is imported, eigenvalues are extracted, and then it is inserted into the trained analysis model to generate multiple groups of possible imaging matrix models.

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

[0051] For the data of this frame, the echo information generated by the through-wall radar detection system generates an echo matrix with reference to the base attitude information. At the same time, the time-frequency ranging information generates an information matrix of the surface information of the detection area with reference to the base attitude information. Subsequently, the sub-matrix representing the surface information of the detection area in the echo matrix is replaced by the information matrix of the surface information of the detection area converted by the time-frequency ranging information. Then, data is imported. After eigenvalue extraction, it is put into the already trained analysis model to generate multiple groups of possible imaging matrix models. Subsequently, this model is used to perform fuzzy cross-coverage with the matrix model generated from the previous frame data. The models with too high deviation are defined as error models and put forward to the standby area, and the remaining models are stored. At the same time, the stored models in the previous few seconds are called to perform cross-coverage again according to the vehicle's traveling speed. The similarity threshold is gradually reduced according to the increase in the time amount of the called model, and the error models are deleted. Then, referring to the movement of the target and the information output by the master station, an imaging three-dimensional matrix is generated, and finally, the panoramic imaging result of the detection area is output.

[0052] The transceiver antennas used in the through-wall radar detection system include, but are not limited to, the monostatic method in the common state, and also include the bistatic method with the transceiver antennas separated.

[0053] The antenna received signal is mixed with the local oscillator signal through a mixer to obtain a lower-frequency intermediate-frequency signal. The method of reducing the data processing difficulty is covered in the present invention.

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

[0055] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. And 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 invention.

Claims

1. An emergency rescue vehicle-mounted imaging system based on time-frequency transfer technology, characterized in that: It includes information transmission radar antenna system, ranging system, through-wall radar detection system, atomic clock and microcomputer; The atomic clock is used to generate 1PPS signals and 10MHz frequency signals, which are provided to the information transmission radar antenna system, ranging system and wall-penetrating radar detection system; The information transmission radar antenna system is used to generate communication signals under the control of a microcomputer using the 10MHz frequency signal of the atomic clock as the local oscillator, send real-time detection signals to the outside world, and complete information interconnection with other detection units or the main station in the outside world; and receive communication signals from other detection units or the main station in the outside world, and use time and frequency synchronization technology to compensate for the delay of the communication signal before transmitting it to the microcomputer; The ranging system is used to measure the surface morphology of remote obstacles. It transmits the 1PPS signal and 10MHz frequency signal generated by the atomic clock, receives the 1PPS signal and 10MHz frequency signal reflected by the obstacle surface, measures the time difference between the received signal and the signal generated by the atomic clock, and transmits the obtained delay information to the microcomputer. The through-the-wall radar detection system is used to measure the internal morphology of remote obstacles. It transmits the 1PPS signal and 10MHz frequency signal generated by the atomic clock through a phase-locked loop composed of a phase detector, a loop filter and a phase shifter, and performs analog-to-digital conversion on the detection signal and the transmission signal synchronously, and transmits them to the microcomputer. The microcomputer is used to extract features from detection signals, time delay information, and communication signals from other external detection units or the main station, generate a variety of detection results, apply models and cross-cover models, and eliminate erroneous models; it is also used to receive the movement of the detection target provided by artificial information. If the detection target is in motion, the deep convolutional neural network micro-Doppler model is loaded; and the base information of the detection antenna and the communication antenna is received to obtain the detection direction positioning; then a three-dimensional matrix is ​​generated through the model retained after elimination, the deep convolutional neural network micro-Doppler model, and the detection direction positioning to control the signal generator.

2. According to claim 1, the emergency rescue vehicle-mounted imaging system based on time-frequency transfer technology is characterized in that: The information transmission radar antenna system includes 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 under the control of a microcomputer using a 1PPS signal generated by an atomic clock and a 10MHz frequency signal, which is amplified by a first power amplifier and then sent out through a communication antenna. The communication antenna receives communication signals from other external detection units or the main station, and outputs them to the power distributor through the first low noise amplifier and the second power amplifier in sequence; the power distributor divides the signal into three paths, one path is filtered out by the first 10M filter to obtain a 10MHz signal and outputs it to the first time interval and phase difference measurement module, 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 distributor 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 delay information, and controls the delay of the signal output by the power distributor by controlling the first phase shifter to achieve time-frequency synchronization, and then converts the processed communication signal into a digital signal through the first AD converter and transmits it to the microcomputer.

3. According to claim 1, the emergency rescue vehicle-mounted imaging system based on time-frequency transfer technology is characterized in that: The ranging system includes 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 them through the detection antenna; the signal reflected from the obstacle surface is received by the detection antenna and is amplified in turn 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 the signal through the second 10M filter to obtain a 10MHz signal which is output 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, and 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 obtains a precise time interval which is transmitted to the microcomputer.

4. The emergency rescue vehicle-mounted imaging system based on time-frequency transfer technology according to claim 1 is characterized in that: The through-wall radar detection system includes 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 a phase-locked loop formed by a phase detector, a loop filter and a second phase shifter, and is signal-enhanced by a fifth power amplifier before being emitted through a detection antenna. The reflected signals from inside and outside the obstacle are received by the detection antenna and amplified in turn by the second low noise amplifier and the third power amplifier. The received detection signal and the transmitting signal of the detection antenna are converted into digital form by the second AD converter and transmitted to the microcomputer.

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