CN216310269U

CN216310269U - Distance measuring device, receiver, terminal and distance measuring system

Info

Publication number: CN216310269U
Application number: CN202120752488.9U
Authority: CN
Inventors: 张文荣; 包旭鹤; 陆健; 罗鹏; 孙建刚
Original assignee: Guangdong Chengsi Microelectronics Co ltd
Current assignee: Guangdong Chengsi Microelectronics Co ltd
Priority date: 2021-04-13
Filing date: 2021-04-13
Publication date: 2022-04-15
Anticipated expiration: 2031-04-13

Abstract

The utility model relates to a distance measuring device, a receiver, a terminal and a distance measuring system, wherein the device comprises: the analog-to-digital conversion module is used for carrying out band-pass sampling; the orthogonal down-conversion module is used for obtaining a passband complex signal; the multiplication module is used for carrying out conjugate multiplication on the passband complex signal and a preset ultrasonic signal to obtain a phase error signal; the de-winding module is used for de-winding the phase error signal to obtain a target phase error signal; the filtering module is used for windowing and filtering the target phase error signal to obtain a filtered target phase error signal; and the distance measuring module is used for determining the distance according to the filtered target phase error signal. The distance measuring device provided by the embodiment of the utility model can adapt to various environments, has strong adaptability, higher flexibility and higher tolerance degree to carrier frequency offset, and has accurate distance measuring precision in various environments.

Description

Distance measuring device, receiver, terminal and distance measuring system

Technical Field

The utility model relates to the technical field of measurement, in particular to a distance measuring device, a receiver, a terminal and a distance measuring system.

Background

The ultrasonic distance measurement is a non-contact detection technology, is not influenced by light, the color of a measured object and the like, is more sanitary compared with other instruments, is more resistant to severe environments such as moisture, dust, high temperature, corrosive gas and the like, and has the characteristics of less maintenance, no pollution, high reliability, long service life and the like. Therefore, the ultrasonic distance measurement in the air has wide application under special environment, and the distance accuracy can be calibrated on line in different environments. The ultrasonic detection is often rapid, convenient, simple in calculation and easy to realize real-time control, and can reach the index requirement of industrial practicality in the aspect of measurement precision, so that a distance measuring system is required to be equipped so that the mobile robot can automatically avoid the obstacle to walk, and the distance measuring system can timely acquire the position information (distance and direction) from the obstacle.

A conventional ultrasound receiver consists of an ADC, a mixer, a low pass filter and a correlator-based ranging circuit. The received ultrasonic signals are subjected to ADC band-pass sampling to obtain digital baseband signals, then subjected to down-conversion and low-pass filtering to obtain envelope signals, and subjected to peak detection by a correlator, and the distance of the obstacle is estimated according to the position of the peak detection.

In the related art distance measurement method based on peak detection, the detection threshold of the peak is greatly influenced by environmental factors. Therefore, under different application environments, the peak detection threshold needs to be adjusted accordingly.

SUMMERY OF THE UTILITY MODEL

In view of the above, the present invention provides a ranging apparatus, comprising:

the analog-to-digital conversion module is used for carrying out band-pass sampling on the received analog ultrasonic signal to obtain a passband real number signal corresponding to the analog ultrasonic signal;

the orthogonal down-conversion module is connected with the analog-to-digital conversion module and used for performing orthogonal down-conversion processing on the passband real number signal to obtain a passband complex number signal;

the multiplication module is connected to the quadrature down-conversion module and is used for performing conjugate multiplication on the passband complex signal and a preset ultrasonic signal to obtain a phase error signal, wherein the preset ultrasonic signal is a sending end signal corresponding to the analog ultrasonic signal;

the unwrapping module is connected to the multiplication module and used for unwrapping the phase error signal to obtain a target phase error signal;

the filtering module is connected with the de-winding module and used for windowing and filtering the target phase error signal to obtain a filtered target phase error signal;

and the distance measuring module is connected with the filtering module and used for determining the distance according to the filtered target phase error signal.

In one possible embodiment, the analog-to-digital conversion module comprises an analog-to-digital converter arranged to operate in Sigma-Delta mode.

In one possible implementation, the multiplication module includes an inversion unit and a multiplication unit, wherein,

the reversing unit is used for reversing the pass band complex signal and the symbol of the imaginary part of the preset ultrasonic signal to obtain a processed pass band complex signal and a processed preset ultrasonic signal;

the multiplication unit is connected to the reversing unit and used for performing multiplication processing on the processed passband complex signal and the processed preset ultrasonic signal to obtain the phase error signal.

In a possible embodiment, the processed passband complex signal and the processed preset ultrasonic signal each include an inverted imaginary signal obtained by inverting the real signal and the imaginary signal,

the multiplication unit comprises a first multiplier and a second multiplier, wherein,

the first multiplier is used for multiplying 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 for multiplying the processed inverted imaginary part signal of the passband complex signal and the processed inverted imaginary part signal of the preset ultrasonic signal to obtain a second multiplication signal,

wherein the first multiplication signal and the second multiplication signal constitute the phase error signal.

In a possible embodiment, the filtering module comprises a low-pass filter implemented based on a rectangular window to perform a low-pass filtering process on the target phase error signal.

In one possible embodiment, the ranging module comprises:

a time determining unit for determining the ultrasonic propagation time according to the filtered target phase error signal;

and the distance calculation unit is connected with the time determination unit and used for determining the distance according to the ultrasonic propagation time.

In a possible embodiment, the analog ultrasonic signal is from an ultrasonic sensor, and the pass band range of the analog-to-digital conversion module is determined according to the bandwidth of the ultrasonic transmitting device.

According to another aspect of the present invention, there is provided a receiver comprising:

the distance measuring device.

According to another aspect of the present invention, there is provided a terminal, including:

the receiver is described.

According to another aspect of the present invention, there is provided a ranging system, the system comprising:

the ultrasonic wave transmitting device is used for transmitting a preset ultrasonic wave signal to a target object so as to carry out distance measurement on the target object;

the distance measuring device.

Through the device, the distance measuring device provided by the embodiment of the utility model can perform band-pass sampling on a received analog ultrasonic signal to obtain a passband real number signal corresponding to the analog ultrasonic signal, perform conjugate multiplication on the passband complex number signal and a preset ultrasonic signal to obtain a phase error signal, perform unwrapping on the phase error signal to obtain a target phase error signal, perform windowing 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.

Other features and aspects of the present invention will become apparent from the following detailed description of exemplary embodiments, which proceeds with reference to the accompanying drawings.

Drawings

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

Fig. 1 shows a schematic diagram of the principle of ultrasonic ranging according to an embodiment of the present invention.

Fig. 2 shows a block diagram of a ranging apparatus according to an embodiment of the present invention.

Fig. 3 shows a block diagram of a ranging apparatus according to an embodiment of the present invention.

Detailed Description

Various exemplary embodiments, features and aspects of the present invention will be described in detail below with reference to the accompanying drawings. In the drawings, like reference numbers can indicate functionally identical or similar elements. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

In the description of the present invention, it is to be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

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

Furthermore, in the following detailed description, numerous specific details are set forth in order to provide a better understanding of the present invention. It will be understood by those skilled in the art that the present invention may be practiced without some of these specific details. In some instances, methods, procedures, components, and circuits that are well known to those skilled in the art have not been described in detail so as not to obscure the present invention.

Referring to fig. 1, fig. 1 is a schematic diagram illustrating an ultrasonic distance measurement principle according to an embodiment of the utility model.

As shown in fig. 1, in the ultrasonic ranging, an ultrasonic transmitter transmits ultrasonic waves in a certain direction, timing is started at the same time as the transmission time, the ultrasonic waves propagate in the air and return immediately when hitting an obstacle in the process, and the ultrasonic receiver stops timing immediately when receiving reflected waves. The propagation speed of the ultrasonic wave in the air is 340m/s, and the distance(s) of the transmitting point from the obstacle can be calculated according to the time t recorded by the timer, namely: and s is 340 t/2.

Since ultrasonic waves are a kind of sound waves, the sound velocity V is related to temperature. In use, the ultrasonic velocity can be approximated as being substantially constant during propagation if the propagation medium temperature does not vary much. If the requirement on the distance measurement precision is high, the measurement result is subjected to numerical correction by a temperature compensation method. After the sound velocity is determined, the distance can be obtained by measuring the round-trip time of the ultrasonic wave.

From FIG. 1, it can be seen that:

H＝S*cosθ (1)

θ＝arctg(L/H) (2)

wherein, S represents the length of the ultrasonic wave reaching the obstacle, L represents half of the distance between the ultrasonic transmitter and the ultrasonic receiver, H represents the distance to be measured, and theta represents the included angle between H and L.

The distance of ultrasonic propagation is:

2S＝vt (3)

where v represents the propagation velocity of the ultrasonic wave in the medium, and t represents the time required for the ultrasonic wave to travel from transmission to reception.

Substituting the formula (2) and the formula (3) into the formula (1) to obtain:

since the propagation velocity V of the ultrasonic wave is constant at a certain temperature (for example, when the temperature T is 30 degrees, V is 349m/s), when the distance H to be measured is much greater than L, equation (4) becomes:

H＝1/2vt (5)

thus, by the above formula, the measured distance H can be derived.

The related art has low ranging accuracy, and in order to increase the ranging accuracy, an automatic frequency control circuit may be used, but this greatly increases the complexity of the receiving circuit. On the other hand, when the automatic frequency control circuit works in a centimeter-level short-distance measuring mode, the frequency locking time of the automatic frequency control circuit may be longer than the echo delay time, so that the automatic frequency control circuit cannot work normally.

In order to solve the above problems, embodiments of the present invention provide a distance measuring device, which can implement high-precision distance measurement with a low-complexity circuit, and can still work normally in centimeter-level short-distance measurement, thereby improving stability and environmental adaptability of the device and reducing circuit complexity.

Referring to fig. 2, fig. 2 is a block diagram of a distance measuring device according to an embodiment of the utility model.

As shown in fig. 2, the apparatus includes:

the analog-to-digital conversion module 10 is configured to perform bandpass sampling on a received analog ultrasonic signal to obtain a passband real number signal corresponding to the analog ultrasonic signal;

the orthogonal down-conversion module 20 is connected to the analog-to-digital conversion module 10, and configured to perform orthogonal down-conversion processing on the passband real number signal to obtain a passband complex number signal;

a multiplication module 30, connected to the quadrature down-conversion module 20, configured to perform conjugate multiplication on the passband complex signal and a preset ultrasonic signal to obtain a phase error signal, where the preset ultrasonic signal is a sending-end signal corresponding to the analog ultrasonic signal;

the unwrapping module 40 is connected to the multiplying module 30 and is configured to unwrapp the phase error signal to obtain a target phase error signal;

a filtering module 50, connected to the unwrapping module 40, configured to perform windowing filtering processing on the target phase error signal to obtain a filtered target phase error signal;

and a distance measuring module 60 connected to the filtering module 50, configured to determine a distance according to the filtered target phase error signal.

It should be noted that, in the apparatus according to the embodiment of the present invention, each module may be implemented by a digital circuit.

In one possible embodiment, the analog ultrasound signal is from an ultrasound sensor, and the pass band range of the analog-to-digital conversion module 10 is determined according to the bandwidth of the ultrasound emitting device.

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

The implementation manner of the ultrasonic sensor is not limited in the embodiment of the utility model, and a person skilled in the art can adopt a proper ultrasonic sensor according to needs and actual requirements.

In one possible implementation, the analog-to-digital conversion module 10 may include an analog-to-digital converter (ADC) that may be configured to operate in Sigma-Delta mode.

According to the embodiment of the utility model, the analog-to-digital converter is set to be in the sigma-delta mode, so that the quantization noise can be minimized, the signal rate of the received analog ultrasonic signal after bandpass sampling is far greater than the bandwidth of the envelope signal, the analog-to-digital converter can be set to output the digital ultrasonic signal of the single bit code stream, and the area and the power consumption of the analog-to-digital converter ADC can be reduced.

In the embodiment of the utility model, the real passband signal can be obtained after the analog ultrasonic signal is subjected to bandpass sampling by using the analog-to-digital conversion module 10, so that the distance measurement is completed in the passband, and the distance measurement is generally performed in the baseband in the related technology.

In a possible implementation manner, the quadrature down-conversion module 20 may include a quadrature down-conversion circuit, and the embodiment of the present invention does not limit the specific implementation manner of the quadrature down-conversion circuit, and a person skilled in the art may implement the quadrature down-conversion circuit by using related technologies as needed.

In one possible implementation, the multiplication module 30 includes an inversion unit and a multiplication unit, wherein,

The embodiment of the present invention does not limit the specific implementation manner of the inversion unit, and those skilled in the art may implement the inversion unit according to needs, for example, the inversion unit may include an inverter or be implemented by a not logic circuit, and the embodiment of the present invention is not limited thereto.

In a possible embodiment, the processed passband complex signal and the processed preset ultrasonic signal both include an inverted imaginary signal obtained by inverting the real signal and the imaginary signal.

In one example, the multiplication unit may include a first multiplier, a second multiplier, wherein,

The embodiment of the utility model decomposes the complex multiplication of conjugate multiplication into two real number multiplications by using the multiplication unit, thereby reducing the cost of multiplication operation and improving the operation efficiency.

In one possible implementation, the unwrapping module 40 may include an unwrapping circuit, and since the phase error signal has a periodicity of 2 × pi, the embodiment of the present invention may overcome the periodicity by unwrapping to obtain the target phase error signal. The specific implementation manner of the unwrapping module 40 is not limited in the embodiment of the present invention, and those skilled in the art may use an unwrapping circuit of the related art or an unwrapping method of the related art as needed to implement the unwrapping, for example, the unwrapping module 40 may include a peak detection circuit, and detect a peak value and a trough value of the phase error signal by using the peak detection circuit, so as to obtain the target phase error signal according to a detected signal between two peak values of any one 2 pi cycle.

In a possible embodiment, the filtering module 50 may include a low-pass filter implemented based on a rectangular window to perform a low-pass filtering process on the target phase error signal.

The embodiment of the utility model does not limit the specific implementation mode of the low-pass filter, does not limit various parameters of windowing, and can be set by a person skilled in the art according to needs.

In a possible implementation, the ranging module 60 may include:

In one example, the ranging module 60 may be implemented by using related technologies, for example, the ranging module 60 may be implemented by using a dedicated hardware circuit (e.g., a digital circuit), or may be implemented by using a general-purpose hardware circuit (e.g., a central processing unit CPU, a microprocessor MCU, etc.) in combination with existing control logic.

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

and t is d _ p/(2 pi f), wherein d _ p represents the filtered target phase error signal, and f represents the frequency of the ultrasonic signal.

In one example, the distance operation 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 equation 5.

Referring to fig. 3, fig. 3 is a block diagram of a distance measuring device according to an embodiment of the utility model. For example, the apparatus 800 may be a mobile phone, a computer, a digital broadcast terminal, a messaging device, a game console, a tablet device, a medical device, an exercise device, a personal digital assistant, and the like.

Referring to fig. 3, the apparatus 800 may include one or more of the following components: processing component 802, memory 804, power component 806, multimedia component 808, audio component 810, input/output (I/O) interface 812, sensor component 814, and communication component 816.

The processing component 802 generally controls overall operation of the device 800, such as operations associated with display, telephone calls, data communications, camera operations, and recording operations. The processing components 802 may include one or more processors 820 to execute instructions to perform all or a portion of the steps of the methods described above. Further, the processing component 802 can include one or more modules that facilitate interaction between the processing component 802 and other components. For example, the processing component 802 can include a multimedia module to facilitate interaction between the multimedia component 808 and the processing component 802.

The memory 804 is configured to store various types of data to support operations at the apparatus 800. Examples of such data include instructions for any application or method operating on device 800, contact data, phonebook data, messages, pictures, videos, and so forth. The memory 804 may be implemented by any type or combination of volatile or non-volatile memory devices 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 or optical disks.

Power components 806 provide power to the various components of device 800. The power components 806 may include a power management system, one or more power supplies, and other components associated with generating, managing, and distributing power for the apparatus 800.

The multimedia component 808 includes a screen that provides an output interface between the device 800 and a 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 an input signal from a 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 boundary of a 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 facing camera and/or a rear facing camera. The front camera and/or the rear camera may receive external multimedia data when the device 800 is in an operating mode, such as a shooting mode or a video mode. Each front camera and rear camera may be a fixed optical lens system or have a focal length and optical zoom capability.

The audio component 810 is configured to output and/or input audio signals. For example, the audio component 810 includes a Microphone (MIC) configured to receive external audio signals when the apparatus 800 is in an operational mode, such as a call mode, a recording mode, and a voice recognition mode. The received audio signals may further be stored in the memory 804 or transmitted via the communication component 816. In some embodiments, audio component 810 also includes a speaker for outputting audio signals.

The I/O interface 812 provides an interface between the processing component 802 and peripheral interface modules, which may be keyboards, click wheels, buttons, etc. These buttons may include, but are not limited to: a home button, a volume button, a start button, and a lock button.

The sensor assembly 814 includes one or more sensors for providing various aspects of state assessment for the device 800. For example, the sensor assembly 814 may detect the open/closed status of the device 800, the relative positioning of components, such as a display and keypad of the device 800, the sensor assembly 814 may also detect a change in the position 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 a change in the temperature of the device 800. 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 a light 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 acceleration sensor, a gyroscope sensor, a magnetic sensor, a pressure sensor, or a temperature sensor.

The communication component 816 is configured to facilitate communications between the apparatus 800 and other devices in a wired or wireless manner. The device 800 may 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 further includes a Near Field Communication (NFC) module to facilitate short-range communications. For example, the NFC module may be implemented based on Radio Frequency Identification (RFID) technology, infrared data association (IrDA) technology, Ultra Wideband (UWB) technology, Bluetooth (BT) technology, and other technologies.

Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen in order to best explain the principles of the embodiments, the practical application, or improvements made to the technology in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A ranging apparatus, the apparatus comprising:

2. The apparatus of claim 1, wherein the analog-to-digital conversion module comprises an analog-to-digital converter configured to operate in a Sigma-Delta mode.

3. The apparatus of claim 1, wherein the multiplication module comprises an inversion unit and a multiplication unit, wherein,

4. The apparatus of claim 3, wherein the processed passband complex signal and the processed predetermined ultrasonic signal each comprise an inverted imaginary signal obtained by inverting a real signal and an imaginary signal,

5. The apparatus of claim 1, wherein the filtering module comprises a low pass filter implemented based on a rectangular window to perform a low pass filtering process on the target phase error signal.

6. The apparatus of claim 1, wherein the ranging module comprises:

7. The device of claim 1, wherein the analog ultrasound signal is from an ultrasound transducer, and the pass band range of the analog-to-digital conversion module is determined according to the bandwidth of the ultrasound emitting device.

8. A receiver, characterized in that the receiver comprises:

a ranging apparatus as claimed in any of claims 1 to 7.

9. A terminal, characterized in that the terminal comprises:

the receiver of claim 8.

10. A ranging system, the system comprising:

a ranging apparatus as claimed in any of claims 1 to 7.