Distance measuring device, receiver, terminal and distance measuring system

Abstract

The present disclosure relates to a distance measuring device, a receiver, a terminal and a distance measuring system, wherein the device comprises: an analog-to-digital conversion module for performing bandpass sampling; an orthogonal down-conversion module for obtaining a passband complex signal; a multiplication module for conjugating and multiplying the passband complex signal with a preset ultrasonic signal to obtain a phase error signal; an unwrapping module for unwrapping the phase error signal to obtain a target phase error signal; a filtering module for windowing and filtering the target phase error signal to obtain a filtered target phase error signal; and a distance measuring module for determining a distance according to the filtered target phase error signal. The distance measuring device of the present disclosure embodiment can adapt to a variety of environments, has strong adaptability, high flexibility, high tolerance to carrier frequency deviation, and has accurate distance measuring accuracy in various environments.

Description

Technical Field

[0001] The present disclosure relates to the field of measurement technology, and in particular to a distance measuring device, a receiver, a terminal and a distance measuring system. Background Art

[0002] Since ultrasonic ranging 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 more resistant to harsh environments such as moisture, dust, high temperature, corrosive gases, etc. It has the characteristics of low maintenance, no pollution, high reliability, and long life. Therefore, ultrasonic ranging 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 relatively fast, convenient, simple to calculate, easy to achieve real-time control, and can meet the industrial practical index requirements in terms of measurement accuracy. Therefore, in order to enable the mobile robot to automatically avoid obstacles and walk, it must be equipped with a ranging system so that it can obtain the position information (distance and direction) of the obstacles in a timely manner.

[0003] The traditional ultrasonic receiver consists of an ADC, a mixer, a low-pass filter, and a correlator-based ranging circuit. The received ultrasonic signal is first sampled by the ADC bandpass to obtain a digital baseband signal, then down-converted and low-pass filtered to obtain an envelope signal, and then peak detected by the correlator to estimate the distance to the obstacle based on the peak detection position.

[0004] In the peak detection-based ranging method of the related art, the peak detection threshold is greatly affected by environmental factors. Therefore, in different application environments, the peak detection threshold needs to be adjusted accordingly. Summary of the invention

[0005] In view of this, the present disclosure proposes a distance measuring device, the device comprising:

[0006] The analog-to-digital conversion module is used to perform bandpass sampling on the received analog ultrasonic signal to obtain a passband real number signal corresponding to the analog ultrasonic signal;

[0007] An orthogonal down-conversion module, connected to the analog-to-digital conversion module, for performing orthogonal down-conversion processing on the passband real signal to obtain a passband complex signal;

[0008] A multiplication module, connected to the orthogonal down-conversion module, for conjugating and multiplying the passband complex signal with a preset ultrasonic signal to obtain a phase error signal, wherein the preset ultrasonic signal is a transmitting end signal corresponding to the analog ultrasonic signal;

[0009] an unwrapping module, connected to the multiplication module, and configured to unwrap the phase error signal to obtain a target phase error signal;

[0010] A filtering module, connected to the dewrapping module, configured to perform window filtering on the target phase error signal to obtain a filtered target phase error signal;

[0011] The distance measuring module is connected to the filtering module and is used to determine the distance according to the filtered target phase error signal.

[0012] In a possible implementation, the analog-to-digital conversion module includes an analog-to-digital converter, and the analog-to-digital converter is configured to operate in a Sigma-Delta mode.

[0013] In a possible implementation, the multiplication module includes a reverse unit and a multiplication unit, wherein:

[0014] The inversion unit is used to perform inverse processing on the signs of the passband complex signal and the imaginary part of the preset ultrasonic signal to obtain a processed passband complex signal and a processed preset ultrasonic signal;

[0015] The multiplication unit is connected to the inversion unit, and is used to perform multiplication processing on the processed passband complex signal and the processed preset ultrasonic signal to obtain the phase error signal.

[0016] In a possible implementation manner, the processed passband complex signal and the processed preset ultrasonic signal both include a real signal and an imaginary signal which are inverted after reverse processing.

[0017] The multiplication unit includes a first multiplier and a second multiplier, wherein:

[0018] The first multiplier is used to perform multiplication processing on the processed real part signal of the passband complex signal and the processed real part signal of the preset ultrasonic signal to obtain a first multiplication signal.

[0019] The second multiplier is used to perform multiplication processing on the negated imaginary part signal of the processed passband complex signal and the negated imaginary part signal of the processed preset ultrasonic signal to obtain a second multiplication signal.

[0020] The first multiplication signal and the second multiplication signal constitute the phase error signal.

[0021] In a possible implementation manner, the filtering module includes a low-pass filter, and the low-pass filter is implemented based on a rectangular window to perform low-pass filtering on the target phase error signal.

[0022] In a possible implementation, the ranging module includes:

[0023] a time determination unit, configured to determine an ultrasonic wave propagation time according to the filtered target phase error signal;

[0024] The distance calculation unit is connected to the time determination unit and is used to determine the distance according to the ultrasonic wave propagation time.

[0025] In a possible implementation, the analog ultrasonic signal comes from an ultrasonic sensor, and the passband range of the analog-to-digital conversion module is determined according to the bandwidth of the ultrasonic transmitting device.

[0026] According to another aspect of the present disclosure, a receiver is provided, the receiver comprising:

[0027] The distance measuring device.

[0028] According to another aspect of the present disclosure, a terminal is provided, the terminal comprising:

[0029] The receiver.

[0030] According to another aspect of the present disclosure, a ranging system is provided, the system comprising:

[0031] An ultrasonic transmitting device, used to transmit a preset ultrasonic signal to a target object so as to measure the distance to the target object;

[0032] The distance measuring device.

[0033] Through the above device, the embodiment of the present disclosure can perform bandpass sampling on the received analog ultrasonic signal to obtain a passband real signal corresponding to the analog ultrasonic signal, conjugate multiply the passband complex signal with the preset ultrasonic signal to obtain a phase error signal, unwrap the phase error signal to obtain a target phase error signal, perform window filtering on the target phase error signal to obtain a filtered target phase error signal, and determine the distance according to the filtered target phase error signal. The ranging device of the embodiment of the present disclosure can adapt to a variety of environments, has strong adaptability, high flexibility, high tolerance to carrier frequency deviation, and has accurate ranging accuracy in various environments.

[0034] 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

[0035] 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.

[0036] Figure 1 A schematic diagram of the ultrasonic ranging principle according to an embodiment of the present disclosure is shown.

[0037] Figure 2 A block diagram of a distance measuring device according to an embodiment of the present disclosure is shown.

[0038] Figure 3 A block diagram of a distance measuring device according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0039] 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.

[0040] In the description of the present disclosure, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present disclosure.

[0041] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present disclosure, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0042] In the present disclosure, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, 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, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0043] 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.

[0044] 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.

[0045] See also Figure 1 , Figure 1 A schematic diagram of the ultrasonic ranging principle according to an embodiment of the present disclosure is shown.

[0046] like Figure 1 As 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.

[0047] 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.

[0048] according to Figure 1 We can get:

[0049] H=S*cosθ (1)

[0050] θ=arctg(L / H) (2)

[0051] Among them, S represents the length of the ultrasonic wave to reach the obstacle, L represents half of 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.

[0052] The distance that ultrasound travels is:

[0053] 2S=vt (3)

[0054] 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.

[0055] Substituting formula (2) and formula (3) into formula (1), we get:

[0056]

[0057] 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:

[0058] H=1 / 2vt (5)

[0059] Therefore, through the above formula, the measured distance H can be obtained.

[0060] The ranging accuracy of the related technology is low. In order to increase the ranging accuracy, an automatic frequency control circuit can be used, but this greatly increases the complexity of the receiving circuit. On the other hand, when working in the centimeter-level short-distance ranging mode, the frequency locking time of the automatic frequency control circuit may be greater than the echo delay time, causing it to not work properly.

[0061] To solve the above problems, the embodiments of the present disclosure propose a ranging device that can achieve high-precision ranging with a low-complexity circuit and can still work normally under centimeter-level short-distance ranging, thereby improving the stability and environmental adaptability of the device and reducing circuit complexity.

[0062] See also Figure 2 , Figure 2 A block diagram of a distance measuring device according to an embodiment of the present disclosure is shown.

[0063] like Figure 2 As shown, the device comprises:

[0064] The analog-to-digital conversion module 10 is used to perform bandpass sampling on the received analog ultrasonic signal to obtain a passband real number signal corresponding to the analog ultrasonic signal;

[0065] An orthogonal down-conversion module 20, connected to the analog-to-digital conversion module 10, for performing orthogonal down-conversion processing on the passband real signal to obtain a passband complex signal;

[0066] A multiplication module 30, connected to the orthogonal down-conversion module 20, for conjugating and multiplying the passband complex signal with a preset ultrasonic signal to obtain a phase error signal, wherein the preset ultrasonic signal is a transmitting end signal corresponding to the analog ultrasonic signal;

[0067] An unwrapping module 40, connected to the multiplication module 30, for unwrapping the phase error signal to obtain a target phase error signal;

[0068] A filtering module 50, connected to the unwrapping module 40, for windowing and filtering the target phase error signal to obtain a filtered target phase error signal;

[0069] The distance measuring module 60 is connected to the filtering module 50 and is used to determine the distance according to the filtered target phase error signal.

[0070] Through the above device, the embodiment of the present disclosure can perform bandpass sampling on the received analog ultrasonic signal to obtain a passband real signal corresponding to the analog ultrasonic signal, conjugate multiply the passband complex signal with the preset ultrasonic signal to obtain a phase error signal, unwrap the phase error signal to obtain a target phase error signal, perform window filtering on the target phase error signal to obtain a filtered target phase error signal, and determine the distance according to the filtered target phase error signal. The ranging device of the embodiment of the present disclosure can adapt to a variety of environments, has strong adaptability, high flexibility, high tolerance to carrier frequency deviation, and has accurate ranging accuracy in various environments.

[0071] It should be noted that, in the device of the embodiment of the present disclosure, each module can be implemented by a digital circuit.

[0072] In a possible implementation, the analog ultrasonic signal comes from an ultrasonic sensor, and the passband range of the analog-to-digital conversion module 10 is determined according to the bandwidth of the ultrasonic transmitting device.

[0073] In one example, the ultrasonic sensor (ultrasonic transducer) can receive an ultrasonic signal, convert the ultrasonic signal into an analog ultrasonic signal, and then input the analog ultrasonic signal into the analog-to-digital conversion module 10 for analog-to-digital conversion.

[0074] The embodiments of the present disclosure do not limit the implementation method of the ultrasonic sensor, and those skilled in the art may adopt a suitable ultrasonic sensor according to needs and actual requirements.

[0075] In a possible implementation, the analog-to-digital conversion module 10 may include an analog-to-digital converter (ADC), and the analog-to-digital converter may be configured to operate in a Sigma-Delta mode.

[0076] The disclosed embodiment can minimize quantization noise by setting the analog-to-digital converter to sigma-delta mode. The signal rate after bandpass sampling of the received analog ultrasonic signal is much larger than the bandwidth of the envelope signal. The analog-to-digital converter can be set to output a digital ultrasonic signal of a single-bit code stream, thereby reducing the area and power consumption of the analog-to-digital converter ADC.

[0077] The embodiment of the present disclosure utilizes the scale-to-digital conversion module 10 to perform a passband on the analog ultrasonic signal, thereby obtaining a passband real number signal, thereby completing ranging within the passband. While the related art generally performs ranging in the baseband, the embodiment of the present disclosure implements ranging in the passband, which can increase the anti-interference capability and improve the environmental adaptability of the device.

[0078] In a possible implementation, the orthogonal down-conversion module 20 may include an orthogonal down-conversion circuit. The embodiments of the present disclosure do not limit the specific implementation of the orthogonal down-conversion circuit, and those skilled in the art may implement it using relevant technologies as needed.

[0079] In a possible implementation, the multiplication module 30 includes a reverse unit and a multiplication unit, wherein:

[0080] The inversion unit is used to perform inverse processing on the signs of the passband complex signal and the imaginary part of the preset ultrasonic signal to obtain a processed passband complex signal and a processed preset ultrasonic signal;

[0081] The multiplication unit is connected to the inversion unit, and is used to perform multiplication processing on the processed passband complex signal and the processed preset ultrasonic signal to obtain the phase error signal.

[0082] The embodiments of the present disclosure do not limit the specific implementation method of the reverse unit, and those skilled in the art can implement it as needed. For example, the reverse unit may include an inverter, or be implemented by a NOT logic circuit, and the embodiments of the present disclosure do not limit this.

[0083] In a possible implementation manner, the processed passband complex signal and the processed preset ultrasonic signal both include a negated imaginary signal obtained by inversely processing the real signal and the imaginary signal.

[0084] In one example, the multiplication unit may include a first multiplier and a second multiplier, wherein:

[0085] The first multiplier is used to perform multiplication processing on the processed real part signal of the passband complex signal and the processed real part signal of the preset ultrasonic signal to obtain a first multiplication signal.

[0086] The second multiplier is used to perform multiplication processing on the negated imaginary part signal of the processed passband complex signal and the negated imaginary part signal of the processed preset ultrasonic signal to obtain a second multiplication signal.

[0087] The first multiplication signal and the second multiplication signal constitute the phase error signal.

[0088] The disclosed embodiment utilizes a multiplication unit to decompose the complex number multiplication of conjugate multiplication into two real number multiplications, which can reduce the multiplication operation cost and improve the operation efficiency.

[0089] In a possible implementation, the unwinding module 40 may include an unwinding circuit. Since the phase error signal has a periodicity of 2×π, the embodiment of the present disclosure can overcome the periodicity through unwinding to obtain a target phase error signal. The embodiment of the present disclosure does not limit the specific implementation of the unwinding module 40. Those skilled in the art can use the unwinding circuit of the relevant technology or the unwinding method in the relevant technology as needed to achieve, for example, unwinding can be completed by detecting peak jumps. For example, the unwinding module 40 may include a peak detection circuit, and the peak detection circuit is used to detect the peak value and the trough value of the phase error signal, and the target phase error signal is obtained according to the signal between the two peaks of any 2π period detected.

[0090] In a possible implementation, the filtering module 50 may include a low-pass filter, which is implemented based on a rectangular window to perform low-pass filtering on the target phase error signal.

[0091] The embodiments of the present disclosure do not limit the specific implementation of the low-pass filter, and do not limit the parameters of windowing, and those skilled in the art can set them as needed.

[0092] In a possible implementation, the distance measurement module 60 may include:

[0093] a time determination unit, configured to determine an ultrasonic wave propagation time according to the filtered target phase error signal;

[0094] The distance calculation unit is connected to the time determination unit and is used to determine the distance according to the ultrasonic wave propagation time.

[0095] In one example, the ranging module 60 can be implemented using relevant technologies. For example, the ranging module 60 can be implemented using a dedicated hardware circuit (such as a digital circuit), or it can be implemented using a general hardware circuit (such as a central processing unit CPU, a microprocessor MCU, etc.) combined with existing control logic.

[0096] In one example, the time determination unit may determine the ultrasonic wave propagation time by using the filtered target phase error signal and the frequency of the ultrasonic wave signal. For example, the ultrasonic wave propagation time t may be determined according to the following formula:

[0097] t=d_p / (2*π*f), wherein d_p represents the filtered target phase error signal, and f represents the frequency of the ultrasonic signal.

[0098] In an example, the distance calculation unit may determine the distance using the ultrasonic wave propagation time and the ultrasonic wave propagation speed. For example, the distance may be determined according to Formula 5.

[0099] Through the above device, the embodiment of the present disclosure can perform bandpass sampling on the received analog ultrasonic signal to obtain a passband real signal corresponding to the analog ultrasonic signal, conjugate multiply the passband complex signal with the preset ultrasonic signal to obtain a phase error signal, unwrap the phase error signal to obtain a target phase error signal, perform window filtering on the target phase error signal to obtain a filtered target phase error signal, and determine the distance according to the filtered target phase error signal. The ranging device of the embodiment of the present disclosure can adapt to a variety of environments, has strong adaptability, high flexibility, high tolerance to carrier frequency deviation, and has accurate ranging accuracy in various environments.

[0100] See also Figure 3 , Figure 3 A block diagram of a distance measuring device according to an embodiment of the present disclosure is shown. For example, the device 800 may be a mobile phone, a computer, a digital broadcast terminal, a messaging device, a game console, a tablet device, a medical device, a fitness device, a personal digital assistant, etc.

[0101] Reference Figure 3 , the device 800 may include one or more of the following components: a processing component 802 , a memory 804 , a power component 806 , a multimedia component 808 , an audio component 810 , an input / output (I / O) interface 812 , a sensor component 814 , and a communication component 816 .

[0102] The processing component 802 generally controls the overall operation of the device 800, such as operations associated with display, phone calls, data communications, camera operations, and recording operations. The processing component 802 may include one or more processors 820 to execute instructions to complete all or part of the steps of the above-mentioned method. In addition, the processing component 802 may include one or more modules to facilitate the interaction between the processing component 802 and other components. For example, the processing component 802 may include a multimedia module to facilitate the interaction between the multimedia component 808 and the processing component 802.

[0103] The memory 804 is configured to store various types of data to support operations on the device 800. Examples of such data include instructions for any application or method operating on the device 800, contact data, phone book data, messages, pictures, videos, etc. The memory 804 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk.

[0104] The power supply component 806 provides power to the various components of the device 800. The power supply component 806 may include a power management system, one or more power supplies, and other components associated with generating, managing, and distributing power for the device 800.

[0105] The multimedia component 808 includes a screen that provides an output interface between the device 800 and the user. In some embodiments, the screen may include a liquid crystal display (LCD) and a touch panel (TP). If the screen includes a touch panel, the screen may be implemented as a touch screen to receive input signals from the user. The touch panel includes one or more touch sensors to sense touch, slide, and gestures on the touch panel. The touch sensor may not only sense the boundaries of the touch or slide action, but also detect the duration and pressure associated with the touch or slide operation. In some embodiments, the multimedia component 808 includes a front camera and / or a rear camera. When the device 800 is in an operating mode, such as a shooting mode or a video mode, the front camera and / or the rear camera may receive external multimedia data. Each front camera and rear camera may be a fixed optical lens system or have a focal length and optical zoom capability.

[0106] The audio component 810 is configured to output and / or input audio signals. For example, the audio component 810 includes a microphone (MIC), and when the device 800 is in an operating mode, such as a call mode, a recording mode, and a speech recognition mode, the microphone is configured to receive an external audio signal. The received audio signal can be further stored in the memory 804 or sent via the communication component 816. In some embodiments, the audio component 810 also includes a speaker for outputting audio signals.

[0107] I / O interface 812 provides an interface between processing component 802 and peripheral interface modules, such as keyboards, click wheels, buttons, etc. These buttons may include but are not limited to: home button, volume button, start button, and lock button.

[0108] The sensor assembly 814 includes one or more sensors for providing various aspects of the status assessment of the device 800. For example, the sensor assembly 814 can detect the open / closed state of the device 800, the relative positioning of components, such as the display and keypad of the device 800, and the sensor assembly 814 can also detect the position change of the device 800 or a component of the device 800, the presence or absence of user contact with the device 800, the orientation or acceleration / deceleration of the device 800, and the temperature change of the device 800. The sensor assembly 814 may include a proximity sensor configured to detect the presence of a nearby object without any physical contact. The sensor assembly 814 may also include an optical sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some embodiments, the sensor assembly 814 may also include an accelerometer, a gyroscope sensor, a magnetic sensor, a pressure sensor, or a temperature sensor.

[0109] The communication component 816 is configured to facilitate wired or wireless communication between the device 800 and other devices. The device 800 can access a wireless network based on a communication standard, such as WiFi, 2G or 3G, or a combination thereof. In an exemplary embodiment, the communication component 816 receives a broadcast signal or broadcast-related information from an external broadcast management system via a broadcast channel. In an exemplary embodiment, the communication component 816 also includes a near field communication (NFC) module to facilitate short-range communication. For example, the NFC module can be implemented based on radio frequency identification (RFID) technology, infrared data association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology and other technologies.

[0110] 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 distance measuring device, characterized in that: The device comprises: The analog-to-digital conversion module is used to perform bandpass sampling on the received analog ultrasonic signal to obtain a passband real number signal corresponding to the analog ultrasonic signal; An orthogonal down-conversion module, connected to the analog-to-digital conversion module, for performing orthogonal down-conversion processing on the passband real signal to obtain a passband complex signal; a multiplication module, connected to the orthogonal down-conversion module, for conjugate multiplying the passband complex signal with a preset ultrasonic signal to obtain a phase error signal, wherein the preset ultrasonic signal is a transmitting end signal corresponding to the analog ultrasonic signal, and the multiplication module includes an inversion unit and a multiplication unit, the inversion unit is used to inversely process the signs of the passband complex signal and the imaginary part of the preset ultrasonic signal to obtain a processed passband complex signal and a processed preset ultrasonic signal; the multiplication unit is connected to the inversion unit, for multiplying the processed passband complex signal and the processed preset ultrasonic signal to obtain the phase error signal; an unwrapping module, connected to the multiplication module, and configured to unwrap the phase error signal to obtain a target phase error signal; A filtering module, connected to the dewrapping module, configured to perform window filtering on the target phase error signal to obtain a filtered target phase error signal; A distance measuring module, connected to the filtering module, for determining the distance according to the filtered target phase error signal, The processed passband complex signal and the processed preset ultrasonic signal both include the inverted imaginary signal after the real signal and the imaginary signal are reversely processed. The multiplication unit includes a first multiplier and a second multiplier, wherein: The first multiplier is used to perform multiplication processing on the processed real part signal of the passband complex signal and the processed real part signal of the preset ultrasonic signal to obtain a first multiplication signal. The second multiplier is used to perform multiplication processing on the negated imaginary part signal of the processed passband complex signal and the negated imaginary part signal of the processed preset ultrasonic signal to obtain a second multiplication signal. The first multiplication signal and the second multiplication signal constitute the phase error signal.

2. The device according to claim 1, characterized in that The analog-to-digital conversion module includes an analog-to-digital converter, and the analog-to-digital converter is configured to operate in a Sigma-Delta mode.

3. The device according to claim 1, characterized in that The filtering module includes a low-pass filter, and the low-pass filter is implemented based on a rectangular window to perform low-pass filtering on the target phase error signal.

4. The device according to claim 1, characterized in that The ranging module comprises: a time determination unit, configured to determine an ultrasonic wave propagation time according to the filtered target phase error signal; The distance calculation unit is connected to the time determination unit and is used to determine the distance according to the ultrasonic wave propagation time.

5. The device according to claim 1, characterized in that The analog ultrasonic signal comes from an ultrasonic sensor, and the passband range of the analog-to-digital conversion module is determined according to the bandwidth of the ultrasonic transmitting device.

6. A receiver, characterized in that: The receiver comprises: A distance measuring device as claimed in any one of claims 1 to 5.

7. A terminal, characterized in that: The terminal comprises: A receiver as claimed in claim 6.

8. A distance measurement system, characterized in that: The system comprises: An ultrasonic transmitting device, used to transmit a preset ultrasonic signal to a target object so as to measure the distance to the target object; A distance measuring device as claimed in any one of claims 1 to 5.

Images