阅读说明：本技术 一种低功耗动目标测距雷达的测距方法 (Ranging method of low-power-consumption moving-target ranging radar ) 是由 周德伟 朱欣恩 卢煜旻 于 2021-09-22 设计创作，主要内容包括：本发明公开了一种低功耗动目标测距雷达的测距方法,包括步骤S1：单片机输出多普勒控制信号,以使得低功耗动目标测距雷达进入多普勒模式,从而判断是否有运动目标,如果有则执行步骤S2,否则继续探测运动目标。本发明公开的一种低功耗动目标测距雷达的测距方法,其采用低功耗动目标测距雷达,实现唤醒和测距功能,降低了系统复杂度及成本,同时也能达到同样的低功耗特性,并且采用带采样保持功能的多普勒中频处理电路,可实现同样的低功耗特性。(The invention discloses a ranging method of a low-power consumption moving target ranging radar, which comprises the following steps of S1: the single chip microcomputer outputs a Doppler control signal to enable the low-power-consumption moving-target range radar to enter a Doppler mode, so that whether a moving target exists or not is judged, if yes, the step S2 is executed, and if not, the moving target continues to be detected. The invention discloses a ranging method of a low-power-consumption moving-target ranging radar, which adopts the low-power-consumption moving-target ranging radar to realize the functions of awakening and ranging, reduces the complexity and the cost of a system, simultaneously can achieve the same low-power-consumption characteristic, and adopts a Doppler intermediate frequency processing circuit with a sampling and holding function to realize the same low-power-consumption characteristic.)

1. A distance measurement method of a low-power-consumption moving-target range radar detects a moving target through the low-power-consumption moving-target range radar, and is characterized by comprising the following steps:

step S1: the single chip microcomputer outputs a Doppler control signal to enable the low-power-consumption moving-target range radar to enter a Doppler mode, so that whether a moving target exists or not is judged, if yes, the step S2 is executed, and if not, the moving target continues to be detected;

step S2: the single chip microcomputer outputs FMCW switch signals to enable the low-power-consumption moving-target ranging radar to enter an FMCW mode, and the single chip microcomputer processes the obtained signals to obtain the distance between the moving target and the low-power-consumption moving-target ranging radar.

2. The method as claimed in claim 1, wherein the step S1 is implemented as the following steps:

step S1.1: a radar chip of the low-power-consumption moving-target range radar transmits signals in a first transmission period to detect a moving target;

step S1.2: if the radar chip detects the moving target, the received echo signal is transmitted to an ADC sampling circuit of the single chip microcomputer through the Doppler intermediate frequency processing circuit, the single chip microcomputer judges whether the moving target really exists or not according to the level of the echo signal, if yes, the step S2 is executed, otherwise, the step S1.1 is executed.

3. The method as claimed in claim 2, wherein the step S2 is implemented as the following steps:

step S2.1: the single chip microcomputer outputs an on signal of the FMCW switch signal to activate the FMCW intermediate frequency processing circuit and performs transmission frequency control voltage switching on the radar chip so that the FMCW intermediate frequency processing circuit modulates an output waveform;

step S2.2: the FMCW intermediate frequency processing circuit processes the echo signal obtained by the radar chip to obtain a detection signal and transmits the detection signal to the single chip microcomputer;

step S2.3: the singlechip performs fast Fourier transform processing and moving target processing on the detection signal to obtain the distance between the moving target and the low-power-consumption moving target distance measuring radar.

4. The method as claimed in claim 3, further comprising step S3 after step S2: when the moving target leaves the detection area, the single chip outputs an off signal of the FMCW switch signal to close the FMCW intermediate frequency processing circuit, so that the low-power-consumption moving target ranging radar enters a Doppler mode to continuously detect the moving target.

5. The method as claimed in claim 4, wherein step S1 is preceded by step S0: the singlechip outputs a power supply control signal to the radar chip power supply circuit so that the radar chip power supply circuit supplies power to the radar chip.

Technical Field

The invention belongs to the technical field of radar ranging, and particularly relates to a ranging method of a low-power-consumption moving-target ranging radar.

Background

Ranging applications using microwave radar are already widespread. The automatic door of the airport and the hotel is the application of the microwave detector which is familiar to people, and the application of the microwave detector on the automatic lamp is more and more extensive along with the reduction of the price of the microwave detector. In the field of automobiles, microwave detection is widely applied to backing and collision avoidance. In the fields, the microwave detector can save energy, reduce emission and save cost, and people enjoy the convenience and the reassurance brought by high-tech products, thereby having important practical significance for the research of the microwave sensor.

In the prior art, the FMCW radar modulation signal needs to be processed by FFT, the detected object distance is determined according to the frequency distribution of the intermediate frequency signal, and then the velocity is calculated according to the frequency change caused by the doppler effect, and these calculations all need a relatively high calculation amount and consume relatively large energy. Meanwhile, FMCW radar is generally applied to detection of a moving object (such as a vehicle), which requires continuous transmission of signals for measurement; the characteristics greatly limit the application of the FMCW radar in certain fields, and particularly in some accidental monitoring occasions powered by batteries, the monitoring task is often required to be completed for a long time, however, the continuous working energy consumption of the FMCW radar cannot meet the application requirements of the occasions.

The publication number is: CN108828579A, entitled 'FMCW radar ranging circuit based on infrared awakening', the technical scheme discloses 'an FMCW radar ranging circuit based on infrared awakening', which at least comprises an MCU (microprogrammed control Unit), an FMCW radar ranging module and an infrared detection module, wherein the FMCW radar ranging module and the infrared detection module are electrically connected with the MCU, and the infrared detection module is used for detecting nearby moving targets and generating a first signal to send the first signal to the MCU when detecting the moving targets; the MCU is used for generating a second signal according to the first signal; the FMCW radar ranging module is used for generating and sending radar ranging signals according to the second signals, receiving radar wave feedback signals, processing the signals, generating third signals and sending the third signals to the MCU; the MCU is used for obtaining the distance and the speed of the moving target according to the second signal and the third signal;

although the invention patent discloses reducing power consumption, the invention patent adopts an infrared awakening FMCW distance measuring circuit, and achieves the purpose of reducing power consumption by awakening a radar circuit through infrared, which is different from the technical scheme of the invention.

Therefore, the above problems are further improved.

Disclosure of Invention

The invention mainly aims to provide a ranging method of a low-power-consumption moving-target range radar, which adopts the low-power-consumption moving-target range radar to realize the functions of awakening and ranging, reduces the complexity and the cost of a system, can simultaneously achieve the same low-power-consumption characteristic, and adopts a Doppler intermediate frequency processing circuit with a sampling and holding function to realize the same low-power-consumption characteristic.

The invention also aims to provide a ranging method of the low-power-consumption moving-target ranging radar, wherein a lens is required to be installed on an infrared sensor, the complexity and the cost of a module are high, the same functions and characteristics can be achieved only by using a single radar chip without using the infrared sensor, and the ranging method has the advantages of lower module cost, smaller volume, easier installation and the like.

In order to achieve the above object, the present invention provides a ranging method for a low power consumption moving target range radar, which detects a moving target by the low power consumption moving target range radar, comprising the following steps:

step S1: the single chip microcomputer outputs a Doppler control signal to enable the low-power-consumption moving-target range radar to enter a Doppler mode, so that whether a moving target exists or not is judged, if yes, the step S2 is executed, and if not, the moving target continues to be detected;

step S2: the single chip microcomputer outputs FMCW switch signals to enable the low-power-consumption moving-target ranging radar to enter an FMCW mode, and the single chip microcomputer processes the obtained signals to obtain the distance between the moving target and the low-power-consumption moving-target ranging radar.

As a further preferable embodiment of the above technical means, step S1 is specifically implemented as the following steps:

step S1.1: a radar chip of the low-power consumption moving-target range radar transmits signals in a first transmission period (preferably 10Hz) to detect a moving target (Doppler target);

step S1.2: if the radar chip detects the moving target, the received echo signal is transmitted to an ADC sampling circuit of the single chip microcomputer through the Doppler intermediate frequency processing circuit, the single chip microcomputer judges whether the moving target really exists or not according to the level of the echo signal, if yes, the step S2 is executed, otherwise, the step S1.1 is executed.

As a further preferable embodiment of the above technical means, step S2 is specifically implemented as the following steps:

step S2.1: the single chip microcomputer outputs an on signal of the FMCW switch signal to activate the FMCW intermediate frequency processing circuit and performs transmission frequency control voltage switching on the radar chip so that the FMCW intermediate frequency processing circuit modulates an output waveform;

step S2.2: the FMCW intermediate frequency processing circuit processes the echo signal obtained by the radar chip to obtain a detection signal and transmits the detection signal to the single chip microcomputer;

step S2.3: the singlechip performs fast Fourier transform processing and moving target processing on the detection signal to obtain the distance between the moving target and the low-power-consumption moving target distance measuring radar.

As a further preferable embodiment of the above, the step S2 is followed by a step S3: when the moving target leaves the detection area, the single chip outputs an off signal of the FMCW switch signal to close the FMCW intermediate frequency processing circuit, so that the low-power-consumption moving target ranging radar enters a Doppler mode to continuously detect the moving target.

As a more preferable embodiment of the above, step S1 is preceded by step S0: the singlechip outputs a power supply control signal to the radar chip power supply circuit so that the radar chip power supply circuit supplies power to the radar chip.

Drawings

FIG. 1 is an overall schematic diagram of a ranging method of a low-power-consumption moving-target range radar according to the present invention.

FIG. 2 is a radar circuit diagram of a ranging method of the low power consumption moving target ranging radar of the invention.

FIG. 3 is a Doppler intermediate frequency processing circuit diagram of a ranging method of a low power consumption moving target range radar of the present invention.

FIG. 4 is a diagram of an FMCW intermediate frequency processing circuit of the ranging method of the low power consumption moving target ranging radar of the present invention.

Detailed Description

The following description is presented to disclose the invention so as to enable any person skilled in the art to practice the invention. The preferred embodiments in the following description are given by way of example only, and other obvious variations will occur to those skilled in the art. The basic principles of the invention, as defined in the following description, may be applied to other embodiments, variations, modifications, equivalents, and other technical solutions without departing from the spirit and scope of the invention.

In the preferred embodiment of the present invention, those skilled in the art should note that the single chip and the transceiver antenna, etc. related to the present invention can be regarded as the prior art.

Preferred embodiments.

The invention discloses a ranging method of a low-power-consumption moving-target range radar, which detects a moving target through the low-power-consumption moving-target range radar and comprises the following steps:

step S1: the single chip microcomputer outputs a Doppler control signal to enable the low-power-consumption moving-target range radar to enter a Doppler mode, so that whether a moving target exists or not is judged, if yes, the step S2 is executed, and if not, the moving target continues to be detected;

step S2: the single chip microcomputer outputs FMCW switch signals to enable the low-power-consumption moving-target ranging radar to enter an FMCW mode, and the single chip microcomputer processes the obtained signals to obtain the distance between the moving target and the low-power-consumption moving-target ranging radar.

Specifically, step S1 is implemented as the following steps:

step S1.1: a radar chip of the low-power consumption moving-target range radar transmits signals in a first transmission period (preferably 10Hz) to detect a moving target (Doppler target);

step S1.2: if the radar chip detects the moving target, the received echo signal is transmitted to an ADC sampling circuit of the single chip microcomputer through the Doppler intermediate frequency processing circuit, the single chip microcomputer judges whether the moving target really exists or not according to the level of the echo signal, if yes, the step S2 is executed, otherwise, the step S1.1 is executed.

More specifically, step S2 is specifically implemented as the following steps:

step S2.1: the single chip microcomputer outputs an on signal of the FMCW switch signal to activate the FMCW intermediate frequency processing circuit and performs transmission frequency control voltage switching on the radar chip so that the FMCW intermediate frequency processing circuit modulates an output waveform;

step S2.2: the FMCW intermediate frequency processing circuit processes the echo signal obtained by the radar chip to obtain a detection signal and transmits the detection signal to the single chip microcomputer;

step S2.3: the singlechip performs fast Fourier transform processing and moving target processing on the detection signal to obtain the distance between the moving target and the low-power-consumption moving target distance measuring radar.

Further, step S2 is followed by step S3: when the moving target leaves the detection area, the single chip outputs an off signal of the FMCW switch signal to close the FMCW intermediate frequency processing circuit, so that the low-power-consumption moving target ranging radar enters a Doppler mode to continuously detect the moving target.

Further, step S1 is preceded by step S0: the singlechip outputs a power supply control signal to the radar chip power supply circuit so that the radar chip power supply circuit supplies power to the radar chip.

Preferably, the invention also discloses a low-power consumption moving-target range radar, which comprises a radar circuit, a Doppler intermediate frequency processing circuit, an FMCW (frequency-modulated continuous wave) intermediate frequency processing circuit and a singlechip, wherein:

a first output end of the radar circuit is electrically connected with an input end of the Doppler intermediate frequency processing circuit, and an output end of the Doppler intermediate frequency processing circuit is electrically connected with a first input end of the single chip microcomputer;

the second output end of the radar circuit is electrically connected with the input end of the FMCW intermediate frequency processing circuit, and the output end of the FMCW intermediate frequency processing circuit is electrically connected with the second input end of the single chip microcomputer.

Specifically, the doppler intermediate frequency processing circuit includes an operational amplifier U2, an analog switch U4, an operational amplifier U3B, and an operational amplifier U3A, wherein:

the positive input end of the operational amplifier U2 is electrically connected with the 7 pin (IFI end) of the radar chip U1 of the radar circuit through a resistor R18, the output end of the operational amplifier U2 is electrically connected with the 2 pin of the analog switch U4 through a resistor R15, and the 2 pin of the analog switch U4 is also grounded through a resistor R20;

the 1 pin of the analog switch U4 is electrically connected to the positive input end of the operational amplifier U3B through a resistor R19, the negative input end of the operational amplifier U3B is grounded through a resistor R16 and a capacitor C11, the common terminal of the resistor R16 and the capacitor C11 is electrically connected to one end of the resistor R19 away from the operational amplifier U3B through a capacitor C13, a resistor R12 is connected between the negative input end and the output end of the operational amplifier U3B, and two ends of the resistor R12 are connected in parallel to a capacitor C8;

the output end of the operational amplifier U3B is electrically connected with the negative input end of the operational amplifier U3A sequentially through a capacitor C12, a resistor R13 and a resistor R17, the common connection end of the resistor R13 and the resistor R17 is grounded through a capacitor C15, a capacitor C9 is connected between the negative input end and the output end of the operational amplifier U3A, and the output end of the operational amplifier U3A is electrically connected with the common connection end of the resistor R13 and the resistor R17 through a resistor R10 (the output end of the operational amplifier U3A is electrically connected with the first input end of the single chip microcomputer through a resistor R14).

More specifically, the FMCW if processing circuit includes an op amp U5B and an op amp U5, wherein:

the positive electrode input end of the operational amplifier U5B is electrically connected with the 6 pin (IFQ end) of the radar chip U1 through a resistor R28, the negative electrode input end of the operational amplifier U5B is grounded through a resistor R24 and a capacitor C20 in sequence, a resistor R23 is connected between the negative electrode input end and the output end of the operational amplifier U5B, and two ends of the resistor R23 are connected with a capacitor C18 in parallel;

the output end of the operational amplifier U5B is electrically connected with the negative input end of the operational amplifier U5A through a capacitor C21 and a resistor R25 in sequence, a resistor R22 is connected between the negative input end and the output end of the operational amplifier U5A, and two ends of the resistor R22 are connected with a capacitor C19 in parallel (the output end of the operational amplifier U5A is electrically connected with the second input end of the single chip microcomputer through a resistor R26).

Further, the 3 pin of the radar chip U1 is connected to a transmitting antenna and the 11 pin of the radar chip U1 is connected to a receiving antenna (the transmitting antenna and the receiving antenna may be shared).

Furthermore, the single chip microcomputer is electrically connected with the radar circuit through a radar chip power supply circuit.

The principle of the invention is as follows:

the radar chip adopts an SRK1101T single-chip millimeter wave radar chip of SGR company, and comprises two orthogonal intermediate frequency output ends. One path enters a Doppler intermediate frequency processing circuit and is used for moving target detection and triggering an FMCW distance measuring circuit (FMCW intermediate frequency processing circuit); and the other path enters an FMCW intermediate frequency processing circuit and is used for the ranging function of the moving target. And the two paths of signals are connected with the low-power consumption MCU.

The MCU (singlechip microcomputer) outputs a Doppler control signal for controlling the switch of the Doppler low-intermediate frequency processing circuit; the FMCW switching signal is used for controlling the switch of the FMCW intermediate frequency processing circuit and reducing the power consumption; transmitting frequency control voltage for Doppler and FMCW output waveform modulation; and a radar chip switch signal enters a radar chip power supply circuit and is used for controlling the radar chip to be switched on and off so as to save power consumption.

Doppler mode

The Doppler target is detected with a low-power consumption sample-and-hold circuit at a low transmission period (10 Hz). If a target exists, the echo signal enters an ADC (analog to digital converter) sampling circuit of the MCU after being amplified by the Doppler circuit, whether a moving target exists or not is judged according to the signal level, if the target exists, the FMCW mode is entered, and the FMCW circuit is started. In order to achieve the low power consumption target, the radar chip is started only in the transmitting period (the starting time is 10us), the signal transmitting duty ratio is greatly reduced, and the power consumption is reduced. Meanwhile, during the transmitting quiet period, the MCU also enters a low-power consumption sleep mode, so that the power consumption of the radar is further reduced.

FMCW mode

The transmitting frequency control voltage is adjusted to be switched, the FMCW circuit amplifies and filters the radar echo intermediate frequency signal, and then the radar echo intermediate frequency signal is sent to the MCU to be processed by FFT (fast Fourier transform) and MTI (moving target detection), and the distance between the moving target and the radar is obtained. After the target leaves the detection area, the FMCW circuit is closed, and the module is switched to the Doppler mode to continuously detect the moving target.

The invention works in 65mA circuit under FMCW mode, in Doppler mode, the average current of module can be as low as 100uA, and most of time is in Doppler mode, so the comprehensive power consumption is low.

It should be noted that the technical features of the single chip microcomputer, the transceiver antenna, and the like, which are referred to in the patent application of the present invention, should be regarded as the prior art, and the specific structure, the operation principle, the control mode and the spatial arrangement mode, which may be referred to, of the technical features may be conventional choices in the field, and should not be regarded as the invention point of the patent of the present invention, and the patent of the present invention is not further specifically described.

It will be apparent to those skilled in the art that modifications and equivalents may be made in the embodiments and/or portions thereof without departing from the spirit and scope of the present invention.