CN110833416A - Non-contact driver breath detection device based on RCS changes - Google Patents

Abstract

The invention discloses a non-contact driver breath detection device based on RCS change, which comprises a radio frequency source, a low-frequency noise amplifier, a low-pass filter, an analog-to-digital converter, a single chip microcomputer, a vehicle-mounted control center, a cloud, a transmitter controller, a receiver, a voltage-controlled oscillator and a phase-locked loop, wherein the low-frequency noise amplifier, the analog-to-digital converter and the single chip microcomputer form the receiver; the radio frequency source is connected with the low-frequency noise amplifier through an antenna, the low-frequency noise amplifier is electrically connected with the analog-to-digital converter, the analog-to-digital converter is electrically connected with the single chip microcomputer, the single chip microcomputer is connected with the vehicle-mounted control center in a wired or wireless connection mode, and the vehicle-mounted control center is electrically connected with the cloud end; the transmitter controller is connected with the voltage-controlled oscillator and the phase-locked loop through the SPI interface, the voltage-controlled oscillator and the phase-locked loop are connected with the receiver through the antenna, and the receiver is connected with the vehicle-mounted control center through the USB.

Description

A non-contact driver's breath detection device based on RCS changes

technical field

The present invention is a non-contact driver's breathing detection device based on RCS change, belonging to the technical field of breathing detection equipment.

Background technique

The traditional detection of respiratory rate often uses contact breathing detection methods such as airflow meters and breathing chest straps. Such inspection methods are accurate, but due to complex installation and uncomfortable wearing, it brings inconvenience to users; The proposal of the contact breathing detection technology realizes the acquisition of the driver's breathing frequency without the driver carrying any device or having any contact behavior with the device; the traditional non-contact detection radar, which uses electromagnetic wave reflection, cannot solve the problem. When the human body is twisted, the radar cannot irradiate the chest wall, which brings about the problem of failure of respiratory rate detection. However, the current solutions all have certain limitations and scope of application, and few of the above studies consider the breath detection of subjects in random directions. The radar based on the biological mechanism of chest wall micromotion does not work well without the antenna and the correct orientation of the subject. During sleep monitoring, the subject cannot be asked to keep one position all night, and when he sleeps on his side, the antenna cannot be oriented His chest wall, therefore, it is difficult for radar based on the principle of chest wall micro-motion detection to detect effective information. In addition, in the process of monitoring the driver's breathing, the driver twists his body when operating the steering wheel, which will increase the detection error of the single-station radar. Therefore, it is necessary to further improve the practicability of the test system and the accuracy of the test results. Furthermore, the present invention proposes a forward scattering-based biological radar breathing rate detection scheme.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a non-contact driver's breath detection device based on the change of RCS, so as to solve the problems raised in the above-mentioned background art.

In order to achieve the above purpose, the present invention provides the following technical solutions: A non-contact driver's breath detection device based on RCS changes includes a radio frequency source, a low-frequency noise amplifier, a low-pass filter, an analog-to-digital converter, a single-chip microcomputer, an on-board control center, and a cloud. , transmitter controller, receiver, and voltage-controlled oscillator + phase-locked loop, the low-frequency noise amplifier, analog-to-digital converter and single-chip microcomputer form a receiver; the radio frequency source is connected to the low-frequency noise amplifier through an antenna, and the low-frequency noise amplifier The noise amplifier is electrically connected to the analog-to-digital converter, the analog-to-digital converter is electrically connected to the single-chip microcomputer, the single-chip microcomputer is connected to the vehicle control center through a wired or wireless connection, and the vehicle-mounted control center is electrically connected to the cloud; the transmitter controller Through the SPI interface, it is connected to the voltage-controlled oscillator + phase-locked loop, the voltage-controlled oscillator + phase-locked loop is connected to the receiver through the antenna, and the receiver is connected to the vehicle control center through USB.

Preferably, the low-pass filter can perform envelope detection and synchronous detection on the received signal.

Preferably, a human body is arranged between the radio frequency source and the low-frequency noise amplifier, the radio frequency source generates radio frequency signals of any frequency, and is transmitted to the human body through an antenna, and the radio frequency signals of any frequency bypass the human body, and are then sent to the low frequency by the antenna Noise amplifier; the centers of the antenna connected to the transmitter controller, the human body and the antenna connected to the receiver are on the same horizontal line.

Compared with the prior art, the beneficial effects of the present invention are:

The present invention is a non-contact driver's breath detection device based on RCS change,

(1) Not only can non-contact breathing sensing be realized, and the breathing frequency of people can be automatically detected, but also the forward scattering radar system can be used to accurately detect the breathing rate of people, compared with traditional contact breathing. In terms of detection system, it has better comfort, strong practicability and easy operation.

(2) Compared with other non-contact breathing detection bio-radars, regardless of the position of the person and the rotation angle of the relative antenna, the law of RCS changes with breathing does not change, and it has better robustness to the person's posture, movement and rotation. Rod, is conducive to maintaining the stability and reliability of the system.

(3) The experimental comparison shows that the test error of the device for the respiration rate is low, and the measurement accuracy is high.

Description of drawings

Fig. 1 is the circuit schematic diagram of the present invention;

Fig. 2 is another kind of circuit schematic diagram of the present invention;

Fig. 3 is a block diagram of a detection system of an embodiment of a non-contact driver's breathing detection device based on RCS changes.

In the figure: 1. RF source; 2. Low frequency noise amplifier; 3. Analog-to-digital converter; 4. Single chip; 5. Low-pass filter; 6. Vehicle control center; 7. Cloud; 8. Transmitter controller; 9 , VCO + PLL; 10. Receiver.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "vertical", "upper", "lower", "horizontal", etc. are based on the orientations or positional relationships shown in the drawings, only In order to facilitate the description of the present invention and simplify the description, it is not indicated or implied that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention.

In the description of the present invention, it should also be noted that, unless otherwise expressly specified and limited, the terms "arranged", "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection, It can also be a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or the internal communication between the two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

Embodiment 1 Referring to FIG. 1, the present invention provides a technical solution: a non-contact driver's breath detection device based on RCS changes, characterized in that it includes a radio frequency source 1, a low-frequency noise amplifier 2, a low-pass filter 5, Analog-to-digital converter 3, microcontroller 4, vehicle control center 6, cloud 7, transmitter controller 8, receiver 10, and voltage-controlled oscillator + phase-locked loop 9, the low-frequency noise amplifier 2, analog-to-digital converter 3 The receiver 10 is formed with the single-chip microcomputer 4; the radio frequency source 1 is connected with the low-frequency noise amplifier 2 through the antenna, the low-frequency noise amplifier 2 is electrically connected with the analog-to-digital converter 3, and the analog-to-digital converter 3 is electrically connected with the single-chip microcomputer 4, The single-chip microcomputer 4 is connected to the vehicle-mounted control center 6 through a wired or wireless connection, and the vehicle-mounted control center 6 is electrically connected to the cloud 7; the transmitter controller 8 is connected to the voltage-controlled oscillator + phase-locked loop 9 through the SPI interface, and the voltage The controlled oscillator + phase-locked loop 9 is connected to the receiver 10 through an antenna, and the receiver 10 is connected to the vehicle-mounted control center 6 through USB.

Further, the radio frequency signal of any frequency is first generated by the radio frequency source 1, and transmitted to the human body through the antenna, and then the human respiratory frequency signal is detected from the human body, and the radio frequency signal of any frequency is received into the low-frequency noise amplifier 2 through the antenna. , the received signal obtained by performing envelope detection on the signal is an amplitude modulated signal. The signal passes through the analog-to-digital converter 3 to convert the analog signal into a digital signal. Finally, the converted digital signal is programmed by the single-chip microcomputer 4. The required function, output the test results, and transmit the test results to the vehicle control center 6 via WiFi or Bluetooth wireless transmission or limited transmission, and then to the cloud 7 to monitor the driver's breathing rate.

Embodiment 2 Please refer to FIG. 2. The present invention provides a technical solution: a non-contact driver's breath detection device based on RCS changes, characterized in that it includes a radio frequency source 1, a low-frequency noise amplifier 2, a low-pass filter 5, a mode Digital converter 3, microcontroller 4, vehicle control center 6, cloud 7, transmitter controller 8, receiver 10, and voltage-controlled oscillator + phase-locked loop 9, the low-frequency noise amplifier 2, analog-to-digital converter 3 and The single-chip microcomputer 4 forms the receiver 10; the radio frequency source 1 is connected to the low-frequency noise amplifier 2 through the antenna, the low-frequency noise amplifier 2 is electrically connected to the analog-to-digital converter 3, the analog-to-digital converter 3 is electrically connected to the single-chip microcomputer 4, and the single-chip microcomputer is electrically connected. 4 is connected to the vehicle-mounted control center 6 through a wired or wireless connection, and the vehicle-mounted control center 6 is electrically connected to the cloud 7; the transmitter controller 8 is connected to the voltage-controlled oscillator + phase-locked loop 9 through the SPI interface, and the voltage-controlled The oscillator+phase-locked loop 9 is connected to the receiver 10 through an antenna, and the receiver 10 is connected to the vehicle-mounted control center 6 through USB.

Further, firstly, a 2.4GHz radio frequency signal is generated by the radio frequency source 1, which is transmitted to the human body through the antenna, and then the human breathing frequency signal is detected from the human body, and the radio frequency signal of any frequency is received into the low-frequency noise amplifier 2 through the antenna, and the signal is processed. Synchronous detection, the received signal is a frequency modulation signal, the signal is a low-frequency modulation signal after the low-pass filter 5, the signal passes through the analog-to-digital converter 3, the analog signal is converted into a digital signal, and finally, the converted digital signal The single-chip microcomputer 4 performs programming processing to realize the required functions and output the test results. The test results are transmitted to the vehicle control center 6 through the wireless transmission mode or wired transmission mode of WiFi or Bluetooth, and then to the cloud 7. monitoring of respiratory rate.

Embodiment 3 Please refer to FIG. 3 A kind of non-contact driver's breath detection device based on RCS change, it is characterized in that: comprises a radio frequency source 1, a low frequency noise amplifier 2, a low pass filter 5, an analog-to-digital converter 3, a single-chip microcomputer 4, Vehicle control center 6, cloud 7, transmitter controller 8, receiver 10, and voltage-controlled oscillator + phase-locked loop 9, the low-frequency noise amplifier 2, analog-to-digital converter 3 and single-chip 4 constitute the receiver 10; The radio frequency source 1 is connected to the low-frequency noise amplifier 2 through an antenna, the low-frequency noise amplifier 2 is electrically connected to the analog-to-digital converter 3, the analog-to-digital converter 3 is electrically connected to the single-chip microcomputer 4, and the single-chip microcomputer 4 is wired or wireless. It is connected with the vehicle-mounted control center 6, and the vehicle-mounted control center 6 is electrically connected with the cloud 7; the transmitter controller 8 is connected with the voltage-controlled oscillator+phase-locked loop 9 through the SPI interface, and the voltage-controlled oscillator+phase-locked loop 9 passes through The antenna is connected to the receiver 10, and the receiver 10 is connected to the vehicle-mounted control center 6 through USB.

Further, the STM32F103 single-chip microcomputer acts as the transmitter controller 8 to send the configuration information to the HMC830 voltage-controlled oscillator + phase-locked loop 9 through the SPI bus interface, and then sends the single-frequency continuous signal of any frequency to the human body through the antenna. After the signal bypasses the human body, it reaches the antenna of the receiver 10, and the received signal is analyzed by the spectrum analyzer RSA306B as the receiver 10, and the analysis result is transmitted to the vehicle control center 6 through USB.

Further STM32F103 microcontroller as transmitter controller 8 sends configuration information to the device with integrated voltage-controlled oscillator + phase-locked loop 9 through the SPI bus interface, the voltage-controlled oscillator + phase-locked loop 9 is connected with the transmitting antenna, and has a good frequency spectrum performance and loop bandwidth, with a precise frequency pattern capable of producing an output frequency with zero frequency error, a single frequency is continuously signaled to the human body.

A further HMC830LP6GE is a low noise, wideband, fractional-N phase-locked loop (PLL) that features an integrated voltage controlled oscillator (VCO) with a base frequency of 1500MHz-3000MHz and an integrated VCO output divider, which together allow The HMC830LP6GE generates frequencies from 25MHz to 3000MHz with good spectral performance and loop bandwidth. The HMC830LP6GE can span all frequencies, enabling it to minimize blocker effects and improve receiver sensitivity and emission spectral purity. The HMC830LP6GE can also be an ideal source for a variety of applications such as local oscillators for RF mixers, clock sources for high frequency data converters, or tunable reference sources for ultra-low spurious applications. Other features of the HMC830LP6GE include RF output power control from 0 to 9 dB, an output mute function, and an accurate frequency mode of the delta-Sigma modulator capable of producing an output frequency with zero frequency error.

Working principle 1: The present invention is a non-contact driver's breath detection device based on RCS changes. When in use, first, a radio frequency signal of any frequency is generated by the radio frequency source 1, and is transmitted to the human body through the antenna, and then the human body is detected from the human breath. frequency signal, the radio frequency signal of any frequency is received into the low-frequency noise amplifier 2 through the antenna, the received signal obtained by envelope detection of the signal is an amplitude modulation signal (or the received signal obtained by synchronous detection of the signal is a frequency modulation signal signal, the signal is converted into a low-frequency modulation signal after passing through the low-pass filter 5), and the signal passes through the analog-to-digital converter 3 to convert the analog signal into a digital signal. The required function, output the test results, and transmit the test results to the vehicle control center 6 via WiFi or Bluetooth wireless transmission or wired transmission, and then to the cloud 7 to monitor the driver's breathing rate.

Working principle 2: The present invention is a non-contact driver's breathing detection device based on RCS changes. When in use, firstly, STM32F103 microcontroller is used as the transmitter controller 8, and the configuration information is sent to the voltage-controlled oscillator + phase-locked loop through the SPI bus interface. 9, and then send a single-frequency continuous signal of any frequency to the human body through the antenna. After the electromagnetic signal bypasses the human body, it reaches the receiver antenna, and uses the spectrum analyzer RSA306B as the receiver 10 to analyze the received signal and transmit the analysis result through USB. to the vehicle control center 6.

It is worth noting that the whole device is controlled by the main control button. Since the equipment matched with the control button is a common equipment and belongs to the existing mature technology, its electrical connection relationship and specific circuit structure will not be repeated here.

Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, and substitutions can be made in these embodiments without departing from the principle and spirit of the invention and modifications, the scope of the present invention is defined by the appended claims and their equivalents.

Claims (3)

1. A non-contact driver's breathing detection device based on RCS changes, characterized in that: comprising a radio frequency source (1), a low-frequency noise amplifier (2), a low-pass filter (5), an analog-to-digital converter (3), A single-chip microcomputer (4), an on-board control center (6), a cloud (7), a transmitter controller (8), and a voltage-controlled oscillator + phase-locked loop (9), the low-frequency noise amplifier (2), the analog-to-digital conversion The receiver (10) is composed of a device (3) and a single-chip microcomputer (4); the radio frequency source (1) is connected to a low-frequency noise amplifier (2) through an antenna, and the low-frequency noise amplifier (2) is connected to an analog-to-digital converter (3) Electrical connection, the analog-to-digital converter (3) is electrically connected to the single-chip microcomputer (4), the single-chip microcomputer (4) is connected to the vehicle control center (6) through a wired or wireless connection, and the vehicle-mounted control center (6) is connected to the cloud (7) ) is electrically connected; the transmitter controller (8) is connected to the voltage-controlled oscillator + phase-locked loop (9) through the SPI interface, and the voltage-controlled oscillator + phase-locked loop (9) is connected to the receiver (10) through an antenna Connection, the receiver (10) is connected to the vehicle control center (6) via USB. 2 . The non-contact driver's breath detection device based on RCS change according to claim 1 , wherein the low-pass filter ( 5 ) can perform envelope detection and synchronous detection on the received signal. 3 . 3. A non-contact driver's breath detection device based on RCS change according to claim 1, characterized in that: a human body is arranged between the radio frequency source (1) and the low-frequency noise amplifier (2), the radio frequency The source generates a radio frequency signal of any frequency, which is transmitted to the human body through the antenna, and the radio frequency signal of any frequency bypasses the human body, and is then sent to the low-frequency noise amplifier (2) by the antenna; the antenna connected to the transmitter controller (8), The centers of the human body and the antenna connected to the receiver (10) are on the same horizontal line.

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