Resonance frequency correction device, reversing radar alarm system and distance measurement system

Abstract

The present disclosure relates to a resonant frequency correction device, a reversing radar alarm system and a ranging system, and the device includes: a bandpass sampling module, a down-conversion filter module, and a frequency deviation detection module. Through the above device, the embodiment of the present disclosure can perform bandpass sampling and filtering on the received ultrasonic signal to obtain a complex baseband signal, perform frequency deviation detection on the complex baseband signal to obtain the first carrier frequency deviation of the complex baseband signal, and use the first carrier frequency deviation and the complex baseband signal to determine the second carrier frequency deviation, and use the preset transmission frequency of the ultrasonic transmitter and the second carrier frequency deviation to determine the resonant frequency of the ultrasonic transmitter, so as to perform frequency correction on the ultrasonic transmitter. By correcting the actual resonant frequency of the ultrasonic transmitter, the frequency drift problem can be solved to improve the transmission efficiency, reduce the influence of the carrier frequency deviation, and thus improve the ranging accuracy.

Description

Technical Field

[0001] The present disclosure relates to the field of measurement technology, and in particular to a resonance frequency correction device, a reversing radar alarm system and a distance measurement system. Background Art

[0002] Since ultrasonic distance measurement is a non-contact detection technology, it is not affected by light, the color of the object being measured, etc. It is more hygienic than other instruments, and is more resistant to harsh environments such as moisture, dust, high temperature, and corrosive gases. It has the characteristics of low maintenance, no pollution, high reliability, and long life. Therefore, ultrasonic distance measurement in the air has a wide range of applications in special environments, and can be used for online calibration of distance accuracy in different environments. Ultrasonic detection is often faster, more convenient, simpler to calculate, and easy to achieve real-time control, and can meet industrial practical index requirements in terms of measurement accuracy.

[0003] Ultrasonic sensors are generally self-transmitting and self-receiving, but due to cost considerations, the frequency temperature of the crystal oscillator used in the peripheral circuit is poor, which will cause a large change in the carrier frequency between the receiving time and the transmitting time. The receiving circuit using related technology will cause the demodulated envelope to have a large distortion, which will seriously affect the ranging accuracy. Summary of the invention

[0004] In view of this, the present disclosure proposes a resonant frequency correction device, the device comprising:

[0005] a bandpass sampling module, used for performing bandpass sampling on the received ultrasonic signal to obtain a sampling signal, wherein the ultrasonic signal is generated by an ultrasonic transmitter configured to have a preset transmission frequency;

[0006] A down-conversion filtering module, electrically connected to the bandpass sampling module, for performing orthogonal down-conversion processing on the sampling signal to obtain a complex bandpass signal, and filtering the complex bandpass signal to obtain a complex baseband signal;

[0007] a frequency deviation detection module, electrically connected to the down-conversion filtering module, for performing frequency deviation detection on the complex baseband signal to obtain a first carrier frequency deviation of the complex baseband signal, and determining a second carrier frequency deviation using the first carrier frequency deviation and the complex baseband signal;

[0008] The frequency correction module is electrically connected to the frequency deviation detection module, and is used to determine the resonant frequency of the ultrasonic transmitter by using the preset transmission frequency of the ultrasonic transmitter and the second carrier frequency deviation, so as to perform frequency correction on the ultrasonic transmitter.

[0009] In a possible implementation, the down-conversion filtering module includes:

[0010] A down-conversion unit, used for performing orthogonal down-conversion processing on the sampled signal to obtain the complex bandpass signal;

[0011] A low-pass filtering unit is electrically connected to the down-conversion unit and is used for filtering the complex bandpass signal to obtain the complex baseband signal.

[0012] In a possible implementation manner, the frequency deviation detection module includes:

[0013] A differential phase detection unit, used for performing differential phase detection processing on the complex baseband signal to obtain the first carrier frequency deviation;

[0014] an oscillation unit, electrically connected to the differential phase detector unit and the loop filter unit, and configured to obtain an oscillation signal according to an output of the loop filter unit and the first carrier frequency deviation;

[0015] a multiplication unit, electrically connected to the oscillation unit, for performing multiplication processing on the oscillation signal and the complex baseband signal to obtain a multiplication signal;

[0016] The loop filtering unit is electrically connected to the multiplication unit, and is used to perform loop filtering on the multiplication signal to obtain the second carrier frequency deviation.

[0017] In a possible implementation manner, performing loop filtering on the multiplication signal to obtain the second carrier frequency offset includes:

[0018] Acquire an imaginary signal of the multiplication signal to obtain a phase error signal;

[0019] Perform loop filtering on the phase error signal to obtain the second carrier frequency deviation.

[0020] In a possible implementation manner, the differential phase detection unit includes:

[0021] A phase detection subunit, used for performing phase detection processing on the complex baseband signal to obtain a phase signal;

[0022] The differential subunit is electrically connected to the phase detection subunit and is used to perform differential processing on the phase signal to obtain the first carrier frequency deviation.

[0023] In a possible implementation, the frequency correction module includes:

[0024] a frequency determination unit, configured to determine the resonant frequency of the ultrasonic transmitter by using the preset transmission frequency of the ultrasonic transmitter and the second carrier frequency deviation;

[0025] The frequency correction unit is electrically connected to the frequency determination unit and is used to configure the center frequency of the ultrasonic signal emitted by the ultrasonic transmitter using the determined resonant frequency.

[0026] According to another aspect of the present disclosure, an electronic device is provided, the electronic device comprising:

[0027] The resonant frequency correction device.

[0028] According to another aspect of the present disclosure, a reversing radar warning system and an electronic device of the system are provided.

[0029] According to another aspect of the present disclosure, a ranging system is provided, the system comprising:

[0030] An ultrasonic transmitter, used to generate an ultrasonic signal using a configured preset transmission frequency;

[0031] The resonant frequency correction device is used to determine the resonant frequency of the ultrasonic transmitter using the ultrasonic signal to perform frequency correction on the ultrasonic transmitter;

[0032] The ultrasonic transmitter is also used to generate a ranging ultrasonic signal after frequency correction;

[0033] The distance measuring device is used to receive the distance measuring ultrasonic signal to determine the distance according to the distance measuring ultrasonic signal.

[0034] Through the above device, the embodiment of the present disclosure can perform bandpass sampling on the received ultrasonic signal to obtain a sampling signal, perform orthogonal down-conversion processing on the sampling signal to obtain a complex bandpass signal, and filter the complex bandpass signal to obtain a complex baseband signal, perform frequency deviation detection on the complex baseband signal to obtain a first carrier frequency deviation of the complex baseband signal, and use the first carrier frequency deviation and the complex baseband signal to determine the second carrier frequency deviation, and use the preset transmission frequency of the ultrasonic transmitter and the second carrier frequency deviation to determine the resonant frequency of the ultrasonic transmitter to perform frequency correction on the ultrasonic transmitter. By correcting the actual resonant frequency of the ultrasonic transmitter, the frequency drift problem can be solved to improve the transmission efficiency, reduce the influence of the carrier frequency deviation, and thus improve the ranging accuracy.

[0035] Further features and aspects of the present disclosure will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the disclosure and, together with the description, serve to explain the principles of the disclosure.

[0037] Figure 1 A schematic diagram of the ultrasonic ranging principle according to an embodiment of the present disclosure is shown.

[0038] Figure 2 A schematic diagram of a resonant frequency correction device according to an embodiment of the present disclosure is shown.

[0039] Figure 3 A schematic diagram of a resonant frequency correction device according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0040] Various exemplary embodiments, features and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0041] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0042] In addition, in order to better illustrate the present disclosure, numerous specific details are given in the following specific embodiments. It should be understood by those skilled in the art that the present disclosure can also be implemented without certain specific details. In some examples, methods, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present disclosure.

[0043] The reversing radar alarm system used in car reversing is commonly known as reversing radar. When the car is reversing, the ultrasonic reversing radar uses the ultrasonic ranging principle to detect the distance between the rear of the car and the obstacle. When the rear of the car detects an obstacle, the reversing radar will dynamically display the distance to the obstacle in real time. When the set safety warning value is reached, the reversing radar will immediately sound an alarm to warn the driver and assist the driver to reverse safely. Most cars are now equipped with reversing radar.

[0044] The reversing radar uses an ultrasonic generator (ultrasonic transducer) to emit ultrasonic waves, and uses an ultrasonic sensor to receive ultrasonic waves for ranging. The ultrasonic generator and ultrasonic sensor can be integrated in the same device or set separately.

[0045] The ultrasonic ranging method is introduced as an example below.

[0046] See also Figure 1 , Figure 1 A schematic diagram of the ultrasonic ranging principle according to an embodiment of the present disclosure is shown.

[0047] like Figure 1As shown in the figure, in ultrasonic ranging, the ultrasonic transmitter transmits ultrasonic waves in a certain direction, and the timing starts at the same time as the transmission. The ultrasonic waves propagate in the air, and immediately return when they encounter obstacles on the way. The ultrasonic receiver stops timing immediately when it receives the reflected wave. The propagation speed of ultrasonic waves in the air is 340m / s. According to the time t recorded by the timer, the distance (s) from the transmitting point to the obstacle can be calculated, that is: s = 340t / 2.

[0048] Since ultrasound is a sound wave, its sound velocity V is related to temperature. When in use, if the temperature of the propagation medium does not change much, it can be approximately considered that the speed of ultrasound is basically unchanged during the propagation process. If the distance measurement accuracy is very high, the measurement result should be numerically corrected by temperature compensation. After the sound velocity is determined, the distance can be obtained by measuring the round-trip time of the ultrasound.

[0049] according to Figure 1 We can get:

[0050] H=S*cosθ (1)

[0051] θ=arctg(L / H) (2)

[0052] Where S represents the length of the ultrasonic wave to reach the obstacle, L represents half the distance between the ultrasonic transmitter and the ultrasonic receiver, H represents the distance to be measured, and θ represents the angle between H and L.

[0053] The distance that ultrasound travels is:

[0054] 2S=vt (3)

[0055] Among them, v represents the propagation speed of ultrasound in the medium, and t represents the time required for ultrasound to be transmitted and received.

[0056] Substituting formula (2) and formula (3) into formula (1), we get:

[0057]

[0058] Because the propagation speed v of ultrasound is a constant at a certain temperature (for example, at temperature T = 30 degrees, V = 349 m / s), when the distance H to be measured is much greater than L, formula (4) becomes:

[0059] H=1 / 2vt (5)

[0060] Therefore, through the above formula, the measured distance H can be obtained.

[0061] The resonant frequency of an ultrasonic transmitter (such as an ultrasonic transducer) is f0, so the transmitted ultrasonic signal can be considered as an amplitude modulated signal with a center frequency of f0. The envelope of the amplitude modulated signal depends on the device characteristics of the ultrasonic transmitter.

[0062] The resonant frequency of the ultrasonic transmitter is a very important parameter, but factors such as ambient temperature and component aging can cause the resonant frequency to drift, and the drift of the resonant frequency can reduce the transmission efficiency of the ultrasonic transmitter and reduce the effective detection distance. When there is a large carrier frequency offset at both ends of the transmitter and receiver, the ranging accuracy will be seriously affected.

[0063] To solve the above problems, the embodiments of the present disclosure propose a resonant frequency correction device, which can correct the frequency of the ultrasonic transmitter, improve the transmission efficiency, reduce the influence of the carrier frequency deviation, and thus improve the ranging accuracy.

[0064] See also Figure 2 , Figure 2 A schematic diagram of a resonant frequency correction device according to an embodiment of the present disclosure is shown.

[0065] In one example, the device may be used in an electronic device to achieve frequency correction of an ultrasonic transmitter disposed in the electronic device.

[0066] In one example, the electronic device is also called user equipment (UE), mobile station (MS), mobile terminal (MT), etc., which is a device that provides voice and / or data connectivity to users, for example, a handheld device with wireless connection function, a vehicle-mounted device, etc. At present, some examples of terminals are: mobile phones, tablet computers, laptops, PDAs, mobile internet devices (MID), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, wireless terminals in Internet of Vehicles, etc.

[0067] In one example, the device or electronic device may be provided in a reversing radar warning system to implement frequency correction of an ultrasonic transmitter when reversing.

[0068] In one example, the reversing radar warning system can be set in various movable devices, such as a car.

[0069] like Figure 2 As shown, the device comprises:

[0070] A bandpass sampling module 10, configured to perform bandpass sampling on a received ultrasonic signal to obtain a sampling signal, wherein the ultrasonic signal is generated by an ultrasonic transmitter configured to have a preset transmission frequency;

[0071] The down-conversion filtering module 20 is electrically connected to the bandpass sampling module 10, and is used to perform orthogonal down-conversion processing on the sampling signal to obtain a complex bandpass signal, and filter the complex bandpass signal to obtain a complex baseband signal;

[0072] A frequency deviation detection module 30, electrically connected to the down-conversion filter module 20, for performing frequency deviation detection on the complex baseband signal to obtain a first carrier frequency deviation of the complex baseband signal, and determining a second carrier frequency deviation using the first carrier frequency deviation and the complex baseband signal;

[0073] The frequency correction module 40 is electrically connected to the frequency deviation detection module 30, and is used to determine the resonant frequency of the ultrasonic transmitter by using the preset transmission frequency of the ultrasonic transmitter and the second carrier frequency deviation, so as to perform frequency correction on the ultrasonic transmitter.

[0074] Through the above device, the embodiment of the present disclosure can perform bandpass sampling on the received ultrasonic signal to obtain a sampling signal, perform orthogonal down-conversion processing on the sampling signal to obtain a complex bandpass signal, and filter the complex bandpass signal to obtain a complex baseband signal, perform frequency deviation detection on the complex baseband signal to obtain a first carrier frequency deviation of the complex baseband signal, and use the first carrier frequency deviation and the complex baseband signal to determine the second carrier frequency deviation, and use the preset transmission frequency of the ultrasonic transmitter and the second carrier frequency deviation to determine the resonant frequency of the ultrasonic transmitter to perform frequency correction on the ultrasonic transmitter. By correcting the actual resonant frequency of the ultrasonic transmitter, the frequency drift problem can be solved to improve the transmission efficiency, reduce the influence of the carrier frequency deviation, and thus improve the ranging accuracy.

[0075] It should be noted that, in the resonant frequency correction device proposed in the embodiment of the present disclosure, each module can be implemented by a digital circuit.

[0076] In a possible implementation, the bandpass sampling module may include an analog-to-digital converter (ADC), and the bandpass sampling of the ultrasonic signal may be implemented through the analog-to-digital converter ADC.

[0077] In one example, the analog-to-digital converter may be configured to operate in a Sigma-Delta mode.

[0078] The embodiment of the present disclosure can minimize quantization noise by setting the analog-to-digital converter to the sigma-delta mode, and the signal rate after bandpass sampling of the received ultrasonic signal is much greater than the bandwidth of the envelope signal.

[0079] Of course, in other implementations, the bandpass sampling module may also be implemented by other devices or hardware circuits, which is not limited in the present disclosure.

[0080] See also Figure 3 , Figure 3 A schematic diagram of a resonant frequency correction device according to an embodiment of the present disclosure is shown.

[0081] In a possible implementation, Figure 3 As shown, the down-conversion filtering module 20 may include:

[0082] A down-conversion unit 210, configured to perform orthogonal down-conversion processing on the sampled signal to obtain the complex bandpass signal;

[0083] The low-pass filtering unit 220 is electrically connected to the down-conversion unit 210 and is used to filter the complex bandpass signal to obtain the complex baseband signal.

[0084] In an example, the down-conversion unit 210 may be implemented by a frequency converter in the related art, or may be implemented by a dedicated hardware circuit or a digital circuit. The embodiment of the present disclosure does not limit the specific implementation method of the down-conversion unit.

[0085] In an example, the down-conversion unit 210 may down-convert the center frequency of the sampling signal to 0, thereby obtaining the complex bandpass signal.

[0086] In one example, the low-pass filtering unit 220 may include a low-pass filter to perform low-pass filtering on the complex bandpass signal.

[0087] Through the down-conversion filtering module, the embodiment of the present disclosure can perform down-conversion and filtering processing on the sampling signal output by the bandpass sampling module to obtain a complex baseband signal.

[0088] In a possible implementation, Figure 3 As shown, the frequency deviation detection module 30 may include:

[0089] A differential phase detection unit 310, configured to perform differential phase detection processing on the complex baseband signal to obtain the first carrier frequency deviation;

[0090] an oscillation unit 320, electrically connected to the differential phase detector unit 310 and the loop filter unit 340, and configured to obtain an oscillation signal according to the output of the loop filter unit 340 and the first carrier frequency deviation;

[0091] A multiplication unit 330, electrically connected to the oscillation unit 320, for multiplying the oscillation signal and the complex baseband signal to obtain a multiplication signal;

[0092] The loop filtering unit 340 is electrically connected to the multiplication unit 330, and is used to perform loop filtering on the multiplication signal to obtain the second carrier frequency deviation.

[0093] In a possible implementation manner, the differential phase detection unit 310 may include:

[0094] A phase detection subunit, used for performing phase detection processing on the complex baseband signal to obtain a phase signal;

[0095] The differential subunit is electrically connected to the phase detection subunit and is used to perform differential processing on the phase signal to obtain the first carrier frequency deviation.

[0096] In one example, the phase detection subunit may include a phase detection circuit, and the phase detection circuit may perform an inverse tangent calculation on the complex baseband signal to obtain a phase signal in the complex baseband signal.

[0097] In one example, the differential subunit may include a differential circuit, and the differential circuit may perform a differential operation on the phase signal to obtain a first carrier frequency deviation of the phase signal.

[0098] In one example, the oscillation unit 320 may include an oscillator, such as a digital oscillator.

[0099] In one example, the multiplication unit 330 may include a multiplier.

[0100] In one example, the loop filtering unit 340 may include a loop filter.

[0101] The oscillation unit, the multiplication unit, and the loop filtering unit can be implemented by dedicated hardware circuits.

[0102] In a possible implementation manner, performing loop filtering on the multiplication signal to obtain the second carrier frequency offset may include:

[0103] Acquire an imaginary signal of the multiplication signal to obtain a phase error signal;

[0104] Perform loop filtering on the phase error signal to obtain the second carrier frequency deviation.

[0105] The disclosed embodiment determines the first carrier frequency deviation through a differential phase detection unit, and the oscillation unit generates an oscillation signal using the output of the loop filtering unit and the first carrier frequency deviation and outputs it to the multiplication unit. The multiplication unit multiplies the oscillation signal and the complex baseband signal to obtain a multiplication signal, and then outputs it to the loop filtering unit. The loop filtering unit takes the imaginary signal of the multiplication signal, and the imaginary signal contains phase error information. After loop filtering, the carrier frequency deviation can be obtained.

[0106] In one example, in the initialization phase, the oscillation unit may use the first carrier frequency deviation as an initial input frequency to generate an oscillation signal.

[0107] In an example, when the oscillation unit is initialized, the multiplication unit and the loop filtering unit can operate normally, and the oscillation unit can generate an oscillation signal using the loop filtering unit.

[0108] Through the frequency deviation detection module, the embodiment of the present disclosure can track the frequency deviation of the complex baseband signal and determine the second frequency deviation signal of the complex baseband signal.

[0109] In a possible implementation, Figure 3 As shown, the frequency correction module 40 may include:

[0110] A frequency determination unit 410, configured to determine a resonant frequency of the ultrasonic transmitter using a preset transmission frequency of the ultrasonic transmitter and the second carrier frequency deviation;

[0111] The frequency correction unit 420 is electrically connected to the frequency determination unit 410, and is used to configure the center frequency of the ultrasonic transmitter transmitting the ultrasonic signal using the determined resonance frequency.

[0112] In one example, the frequency determination unit 410 may include an adding circuit, such as an adder, and the frequency determination unit may perform an addition operation on the preset transmission frequency of the ultrasonic transmitter and the second carrier frequency deviation to determine the resonant frequency of the ultrasonic transmitter.

[0113] In one example, the frequency correction unit may include a frequency correction circuit to configure the center frequency of the ultrasonic signal.

[0114] In one example, when the ultrasonic transmitter transmits a signal, it is divided into two stages: forced response and free response. The forced response stage is controlled by the electrical signal applied to the ultrasonic transmitter. The center frequency of the signal in this stage depends on the frequency of the electrical signal. The free response stage is the free response of the ultrasonic transmitter after the electrical signal ends. The present disclosure utilizes the above device to accurately detect the resonant frequency of the ultrasonic transmitter, which has the characteristics of fast detection time and high accuracy.

[0115] The disclosed embodiment uses a fully digital circuit to estimate the resonant frequency of the transducer. After estimating the resonant frequency of the ultrasonic transmitter, the center frequency of the ultrasonic transmitter's transmission signal is adjusted to the estimated resonant frequency, thereby obtaining a higher transmission efficiency. In this way, the influence of the carrier frequency deviation can be ignored in the receiving circuit. At the same time, due to the high consistency of the transmission frequency and the resonant frequency, the accuracy of the distance measurement can be improved.

[0116] According to another aspect of the present disclosure, a reversing radar warning system and an electronic device of the system are provided.

[0117] The reversing radar warning system can be arranged in various movable devices, such as a car.

[0118] According to another aspect of the present disclosure, a ranging system is provided, the system comprising:

[0119] An ultrasonic transmitter, used to generate an ultrasonic signal using a configured preset transmission frequency;

[0120] The resonant frequency correction device is used to determine the resonant frequency of the ultrasonic transmitter using the ultrasonic signal to perform frequency correction on the ultrasonic transmitter;

[0121] The ultrasonic transmitter is also used to generate a ranging ultrasonic signal after frequency correction;

[0122] The distance measuring device is used to receive the distance measuring ultrasonic signal to determine the distance according to the distance measuring ultrasonic signal.

[0123] In one example, the ranging device may be implemented by a hardware circuit. The embodiment of the present disclosure does not limit the specific implementation method of the ranging device. For example, a peak detection circuit is provided in the frequency correction device to detect the peak value of the second carrier frequency deviation, and peak ranging or other methods may be used to achieve the purpose of ranging. Those skilled in the art may implement the ranging device by using relevant technologies.

[0124] Through the above method, the embodiment of the present disclosure can realize the correction of the center frequency of the ultrasonic transmitter in the system, and use the corrected ultrasonic transmitter to perform ranging.

[0125] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A resonant frequency correction device, characterized in that: The device comprises: a bandpass sampling module, used for performing bandpass sampling on the received ultrasonic signal to obtain a sampling signal, wherein the ultrasonic signal is generated by an ultrasonic transmitter configured to have a preset transmission frequency; A down-conversion filtering module, electrically connected to the bandpass sampling module, for performing orthogonal down-conversion processing on the sampling signal to obtain a complex bandpass signal, and filtering the complex bandpass signal to obtain a complex baseband signal; a frequency deviation detection module, electrically connected to the down-conversion filtering module, for performing frequency deviation detection on the complex baseband signal to obtain a first carrier frequency deviation of the complex baseband signal, and determining a second carrier frequency deviation using the first carrier frequency deviation and the complex baseband signal; a frequency correction module, electrically connected to the frequency deviation detection module, for determining the resonant frequency of the ultrasonic transmitter by using the preset transmission frequency of the ultrasonic transmitter and the second carrier frequency deviation, so as to perform frequency correction on the ultrasonic transmitter, The frequency deviation detection module comprises: A differential phase detection unit, used for performing differential phase detection processing on the complex baseband signal to obtain the first carrier frequency deviation; an oscillation unit, electrically connected to the differential phase detector unit and the loop filter unit, and configured to obtain an oscillation signal according to an output of the loop filter unit and the first carrier frequency deviation; a multiplication unit, electrically connected to the oscillation unit, for performing multiplication processing on the oscillation signal and the complex baseband signal to obtain a multiplication signal; The loop filtering unit is electrically connected to the multiplication unit, and is used to perform loop filtering on the multiplication signal to obtain the second carrier frequency deviation. The loop filtering the multiplication signal to obtain the second carrier frequency deviation includes: Acquire an imaginary signal of the multiplication signal to obtain a phase error signal; Perform loop filtering on the phase error signal to obtain the second carrier frequency deviation.

2. The device according to claim 1, characterized in that The down-conversion filter module comprises: A down-conversion unit, used for performing orthogonal down-conversion processing on the sampled signal to obtain the complex bandpass signal; A low-pass filtering unit is electrically connected to the down-conversion unit and is used for filtering the complex bandpass signal to obtain the complex baseband signal.

3. The device according to claim 1, characterized in that The differential phase detection unit comprises: A phase detection subunit, used for performing phase detection processing on the complex baseband signal to obtain a phase signal; The differential subunit is electrically connected to the phase detection subunit and is used to perform differential processing on the phase signal to obtain the first carrier frequency deviation.

4. The device according to claim 1, characterized in that Frequency correction module, including: a frequency determination unit, configured to determine the resonant frequency of the ultrasonic transmitter by using the preset transmission frequency of the ultrasonic transmitter and the second carrier frequency deviation; The frequency correction unit is electrically connected to the frequency determination unit and is used to configure the center frequency of the ultrasonic signal emitted by the ultrasonic transmitter using the determined resonant frequency.

5. An electronic device, characterized in that: The electronic device comprises: A resonant frequency correction device as claimed in any one of claims 1 to 4.

6. A reversing radar alarm system, characterized in that: The system comprises the electronic device of claim 5.

7. A distance measurement system, characterized in that: The system comprises: An ultrasonic transmitter, used to generate an ultrasonic signal using a configured preset transmission frequency; The resonant frequency correction device according to any one of claims 1 to 4, used to determine the resonant frequency of the ultrasonic transmitter using the ultrasonic signal to perform frequency correction on the ultrasonic transmitter; The ultrasonic transmitter is also used to generate a ranging ultrasonic signal after frequency correction; The distance measuring device is used to receive the distance measuring ultrasonic signal to determine the distance according to the distance measuring ultrasonic signal.

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