CN214795189U

CN214795189U - Distance measuring device, receiver and terminal

Info

Publication number: CN214795189U
Application number: CN202023106862.2U
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: 2020-12-21
Filing date: 2020-12-21
Publication date: 2021-11-19
Anticipated expiration: 2030-12-21

Abstract

The utility model relates to a range unit, receiver and terminal, range unit, the device includes: the analog-to-digital conversion module is used for carrying out band-pass sampling on the received analog ultrasonic signals and carrying out analog-to-digital conversion on the sampled signals to obtain digital ultrasonic signals; the phase separation module is used for carrying out phase separation on the digital ultrasonic signals to obtain amplitude signals of the digital ultrasonic signals; the filtering module is used for filtering the amplitude signal to obtain an envelope signal of the amplitude signal; the correlation module is used for performing correlation operation on a preset envelope signal and an envelope signal of the amplitude signal to obtain a correlation signal; and the distance measurement module is electrically connected with the correlation module and used for carrying out peak value detection on the correlation signal and determining the distance by using the peak value obtained by detection. The utility model discloses range unit can eliminate the influence of carrier wave frequency offset, has improved the precision of range finding.

Description

Distance measuring device, receiver and terminal

Technical Field

The utility model relates to a measure technical field, especially relate to a range unit, receiver and terminal.

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 relatively rapid and convenient, the calculation is simple, the real-time control is easy to realize, and the industrial practical index requirement can be met in the aspect of measurement precision.

The ultrasonic sensor is generally self-transmitting and self-receiving, but due to cost, the frequency temperature of a crystal oscillator used by a peripheral circuit is poor, which causes great changes of carrier frequencies at the receiving moment and the transmitting moment, and a receiving circuit utilizing the related art causes great distortion of a demodulated envelope, thereby seriously affecting the precision of the peak value distance measurement method.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model provides a range unit, receiver and terminal to reduce the interference of carrier frequency offset, improve ultrasonic ranging's precision.

According to an aspect of the utility model, a range unit, range unit is proposed, the device includes:

the analog-to-digital conversion module is used for carrying out band-pass sampling on the received analog ultrasonic signals and carrying out analog-to-digital conversion on the sampled signals to obtain digital ultrasonic signals;

the phase separation module is electrically connected to the analog-to-digital conversion module and is used for carrying out phase separation on the digital ultrasonic signals to obtain amplitude signals of the digital ultrasonic signals;

the filtering module is electrically connected to the phase separation module and is used for filtering the amplitude signal to obtain an envelope signal of the amplitude signal;

the correlation module is electrically connected with the filtering module and is used for performing correlation operation on a preset envelope signal and an envelope signal of the amplitude signal to obtain a correlation signal;

and the distance measurement module is electrically connected with the correlation module and used for carrying out peak value detection on the correlation signal and determining the distance by using the peak value obtained by detection.

In one possible implementation, the phase separation module includes a first finite long single-bit impulse response FIR low-pass filter, a second FIR low-pass filter, and an operator, wherein,

the first FIR low-pass filter is used for performing low-pass filtering on the digital ultrasonic signal to obtain a first filtering signal;

the second FIR low-pass filter is used for performing low-pass filtering on the digital ultrasonic signal to obtain a second filtering signal;

the arithmetic unit is electrically connected to the first FIR low-pass filter and the second FIR low-pass filter, and is configured to calculate the first filtering signal and the second filtering signal to obtain an amplitude signal of the digital ultrasonic signal.

In one possible implementation, the operator comprises a squarer, an adder, wherein,

the square arithmetic unit is used for respectively carrying out square arithmetic on the first filtering signal and the second filtering signal to obtain a first square signal and a second square signal;

the addition arithmetic unit is electrically connected to the square arithmetic unit and is used for adding the first square signal and the second square signal to obtain an amplitude signal of the digital ultrasonic signal.

In a possible embodiment, the phase separation module comprises a hilbert transformer.

In a possible implementation, the filtering module comprises a low-pass filter for low-pass filtering the amplitude signal;

the analog-to-digital conversion module comprises an analog-to-digital converter.

In one possible implementation, the correlation module includes a multiplication unit and an accumulation unit,

the multiplication unit is used for multiplying the envelope signal by the corresponding bit of the preset envelope signal to obtain a plurality of intermediate results;

the accumulation unit is electrically connected to the multiplication unit and is used for accumulating the intermediate results to obtain the correlation signal.

In a possible implementation, the ranging module includes a peak detection unit, and the peak detection unit is configured to perform peak detection on the correlation signal, and includes:

the comparison subunit is used for comparing the correlation signal at the current moment with the peak value at the previous moment to obtain a comparison result;

the peak value determining subunit is electrically connected to the comparing subunit and is used for setting the correlation signal at the current moment as the peak value at the current moment when the comparison result is that the correlation signal at the current moment is greater than the peak value at the previous moment; or setting the peak value of the previous moment as the peak value of the current moment when the comparison result shows that the correlation signal of the previous moment is larger than the correlation signal of the current moment.

In one possible implementation, the peak detection unit further includes:

the peak value storage subunit is electrically connected with the comparison subunit and the peak value determination subunit and is used for storing peak values;

a distance measuring unit electrically connected to the peak detecting unit for determining a distance using the detected peak, wherein the distance determining unit determines the distance using the detected peak and includes:

and determining the distance by using the data bit where the peak value is located and the speed of the related signal.

According to another aspect of the present invention, a receiver is provided, the receiver comprising: the distance measuring device.

According to the utility model discloses an on the other hand, provided a terminal, the terminal includes: the receiver is described.

The utility model discloses range unit can be through carrying out the band-pass sampling to the analog ultrasonic signal who receives to carry out analog-to-digital conversion with the signal that the sampling obtained, obtain digital ultrasonic signal, it is right digital ultrasonic signal carries out phase separation, obtains digital ultrasonic signal's amplitude signal, to predetermine envelope signal and amplitude signal's envelope signal carries out correlation operation, obtains correlation signal, right correlation signal carries out peak detection, and utilizes the peak value that the detection obtained to confirm the distance, adopts above device to range finding, has eliminated the influence of carrier frequency offset, has improved the precision of range finding.

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 the specification, illustrate exemplary embodiments, features, and aspects of the present invention and, together with the description, serve to explain the principles of the invention.

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

Fig. 2 shows a block diagram of a distance measuring device according to an embodiment of the present invention.

Fig. 3 shows a block diagram of a distance measuring device 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 are used in the orientation or positional relationship indicated in the drawings for convenience in describing the present invention and for simplicity in description, and are not intended to indicate or imply that the device or element so referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not 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 limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, 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 meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

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, means, elements 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 present invention.

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.

For solving the above problem, the embodiment of the utility model provides a range unit is provided, can realize the high accuracy range finding with the circuit of low complexity to still can normally work under centimetre level short distance measurement, improved the stability and the environmental suitability of device.

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

As shown in fig. 2, the apparatus includes:

the analog-to-digital conversion module 10 is configured to perform band-pass sampling on a received analog ultrasonic signal, and perform analog-to-digital conversion on a signal obtained by the sampling to obtain a digital ultrasonic signal;

the phase separation module 20 is electrically connected to the analog-to-digital conversion module 10, and is configured to perform phase separation on the digital ultrasonic signal to obtain an amplitude signal of the digital ultrasonic signal;

the filtering module 30 is electrically connected to the phase separation module 20, and is configured to perform filtering processing on the amplitude signal to obtain an envelope signal of the amplitude signal;

a correlation module 40, electrically connected to the filtering module 30, configured to perform correlation operation on a preset envelope signal and an envelope signal of the amplitude signal to obtain a correlation signal;

In one possible implementation, the embodiments of the present invention may receive the analog ultrasonic signal through an ultrasonic sensor (ultrasonic transducer).

The embodiment of the utility model provides a do not do the restriction to ultrasonic sensor's implementation, technical personnel in the field can adopt correlation technique to realize, perhaps adopt existing ultrasonic sensor to carry out ultrasonic signal's transmission, receipt.

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 implementation, the analog-to-digital conversion module may comprise an analog-to-digital converter (ADC) arranged to operate in Sigma-Delta mode.

The embodiment of the utility model provides a through setting up analog to digital converter into sigma-delta mode, can be so that quantization noise minimizing, the signal rate after carrying out the band-pass sampling to the analog ultrasonic signal of receiving is far greater than envelope signal's bandwidth.

In one possible implementation, the phase separation module may include a first Finite Impulse Response (FIR) low pass filter, a second FIR low pass filter, and an operator.

In one example, the embodiment of the present invention may configure an FIR filter, where the unit impulse response may be h (N), the length is N, and N is not greater than N and is an integer.

Wherein, FIR filter can adopt FIR filter in the correlation technique, or dispose according to the implementation mode in the correlation technique, to FIR filter's configuration mode, the concrete size of N, the embodiment of the utility model provides a do not restrict.

In one example, the FIR filter h (n) may be further zero-padded (e.g., by 0 between the parameters of h (n)) to obtain a half-band filter g (n).

Wherein, the half-band filter g (n) is an FIR low-pass filter.

In one example, b (n) ═ g (n) × exp (j × pi × n/2) can be obtained from g (n), where exp () represents an exponential function and pi represents a complex number.

In one example, the unit impulse response of the first FIR low pass filter may be real (b (n)), the real part of b (n).

In one example, the unit impulse response of the second FIR low pass filter may be imag (b (n)), i.e., the imaginary part of b (n).

In one example, the first FIR low-pass filter may be configured to low-pass filter the digital ultrasound signal to obtain a first filtered signal.

In one example, the second FIR low-pass filter may be configured to low-pass filter the digital ultrasonic signal to obtain a second filtered signal;

in one example, the arithmetic unit is electrically connected to the first FIR low-pass filter and the second FIR low-pass filter, and may be configured to calculate the first filtered signal and the second filtered signal to obtain an amplitude signal of the digital ultrasonic signal.

In one possible implementation, the operator may include a square operator, an addition operator.

In one example, the square operator may be configured to perform a square operation on the first filtered signal and the second filtered signal respectively to obtain a first square signal and a second square signal.

In one example, the addition operator is electrically connected to the square operator, and may be configured to add the first square signal and the second square signal to obtain an amplitude signal of the digital ultrasonic signal.

The embodiment of the utility model provides a do not restrict square arithmetic unit, addition arithmetic unit's implementation, technical personnel in the field can realize according to correlation technique.

The embodiment of the utility model provides a will through first FIR low pass filter digital ultrasonic signal carries out low pass filtering, obtains first filtering signal, can with second FIR low pass filter digital ultrasonic signal carries out low pass filtering, obtains the second filtering signal, can obtain two way signals (like I way signal, Q way signal) with digital ultrasonic signal separation, compares in the scheme that the correlation technique adopted down conversion module to carry out down conversion, has certain tolerance to the carrier frequency offset, after obtaining two way signals, can will through the arithmetic unit first filtering signal reaches second filtering signal carries out the operation and obtains digital ultrasonic signal's amplitude signal to carry out subsequent processing.

In a possible implementation, the phase separation module may further include a hilbert transformer.

The embodiment of the utility model provides a can also utilize hilbert converter to realize obtaining amplitude signal to digital ultrasonic signal's phase separation.

Wherein, hilbert converter can adopt correlation technique to realize, to its concrete implementation, the embodiment of the utility model provides a do not limit.

In a possible implementation, the filtering module comprises a low-pass filter for low-pass filtering the amplitude signal.

In one possible implementation, the correlation module may include a multiplication unit and an accumulation unit.

In one example, the multiplication unit is configured to multiply the envelope signal by corresponding bits of the preset envelope signal to obtain a plurality of intermediate results.

In one example, the accumulation unit is electrically connected to the multiplication unit, and configured to accumulate the intermediate results to obtain the correlation signal.

In one example, the correlation module can be implemented with a correlator in the correlation technique, or can be implemented with digital circuitry as desired.

In one example, the multiplication unit may include one or more multipliers and the accumulation unit may include one or more adders.

Through relevant module, the embodiment of the utility model provides a can multiply the envelope signal that the filtering module obtained with predetermine the paul signal to add up the result in the middle of a plurality of obtaining, thereby obtain relevant signal, so that follow-up range finding, the implementation is simple, and the circuit complexity is not high, realizes easily that the cost is lower.

In one example, the comparison subunit may be implemented by a comparator, and the peak determination subunit may be implemented by a dedicated hardware circuit, or may be implemented by a general hardware circuit in combination with the control logic.

In a possible implementation, the peak detection unit may further include:

In one example, the peak storage subunit may include a non-volatile memory.

For example, assume that the peak detected by the correlation module after correlation is the 100 th data point, and the data rate during correlation is 100 KHz. Then the distance can be determined according to the formula H1/2 v t.

Assuming that the speed of the ultrasonic wave in the air is 343m/s, H-0.5-343-100/100000-0.343-0.5 m can be obtained according to the distance measurement formula.

In an example, the distance measuring unit 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 an existing control logic, which is not limited by the embodiment of the present invention.

The embodiment of the utility model provides an utilize phase separation module, filtering module to accomplish ultrasonic signal's envelope detection, this method is irrelevant with carrier frequency deviation simultaneously, and the performance does not receive carrier frequency deviation's influence promptly, consequently, has higher precision.

Referring to fig. 3, fig. 3 is a block diagram of a distance measuring device according to an embodiment of the present invention.

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.

In an exemplary embodiment, the apparatus 800 may be implemented by one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), controllers, micro-controllers, microprocessors or other electronic components for performing the above-described methods.

In an exemplary embodiment, a non-transitory computer-readable storage medium, such as the memory 804, is also provided that includes computer program instructions executable by the processor 820 of the device 800 to perform the above-described methods.

While various embodiments of the present invention have been described above, the above description is intended to be illustrative, not exhaustive, and not limited to the disclosed embodiments. 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 phase separation module comprises a first FIR low pass filter, a second FIR low pass filter, an operator,

3. The apparatus of claim 2, wherein the operator comprises a squarer, an adder, wherein,

4. The apparatus of claim 1, wherein the phase separation module comprises a hilbert transformer.

5. The apparatus of claim 1,

the filtering module comprises a low-pass filter for performing low-pass filtering on the amplitude signal;

6. The apparatus of claim 1, wherein the correlation module comprises a multiplication unit and an accumulation unit,

7. The apparatus of claim 1, wherein the ranging module comprises a peak detection unit configured to perform peak detection on the correlation signal, and the peak detection unit comprises:

8. The apparatus of claim 7, wherein the peak detection unit further comprises:

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

the device of any one of claims 1-8.

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

a receiver as claimed in claim 9.