CN213934203U

CN213934203U - Distance measuring device, receiver and terminal

Info

Publication number: CN213934203U
Application number: CN202022944610.0U
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: 2020-12-07
Filing date: 2020-12-07
Publication date: 2021-08-10
Anticipated expiration: 2030-12-07

Abstract

The utility model relates to a range unit, receiver and terminal, the device includes: the analog-to-digital conversion module is used for obtaining a digital ultrasonic signal of the single bit code stream; the first filtering module is used for filtering and extracting the digital ultrasonic signals to obtain digital echo signals; the correlation module is used for performing correlation operation on the polarity of a preset transmitting signal and the digital echo signal by using the adder unit to obtain a correlation signal; the second filtering module is used for filtering the related signals to obtain envelope signals of the related signals; and the distance measuring module is electrically connected with the second filtering module and used for carrying out peak value detection on the envelope signal and determining the distance by using the peak value obtained by detection. The embodiment of the utility model provides a reduced the complexity of circuit, reduced circuit area and consumption, and accomplished the correlation ranging at the passband and have certain tolerance to the carrier frequency offset, reduced the computational complexity of correlator again.

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. Therefore, in order to enable the mobile robot to automatically avoid the obstacle to walk, it is necessary to equip a distance measuring system so as to timely acquire the position information (distance and direction) from the obstacle

However, the receiving circuit in the related art is affected by the carrier frequency offset, which may cause a large distortion of the demodulated envelope, may seriously affect the accuracy of the peak value ranging method, and has a complicated design.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model provides a range unit, receiver and terminal to improve the range finding precision, and reduce the complexity of device.

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

the analog-to-digital conversion module is used for carrying out band-pass sampling on a received analog ultrasonic signal and carrying out analog-to-digital conversion on a signal obtained by sampling to obtain a digital ultrasonic signal of a single-bit code stream, wherein 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 sensor;

the first filtering module is electrically connected to the analog-to-digital conversion module and is used for filtering and extracting the digital ultrasonic signal to obtain a digital echo signal;

the correlation module is electrically connected with the first filtering module, comprises an adder unit and is used for performing correlation operation on the polarity of a preset transmitting signal and the digital echo signal by using the adder unit to obtain a correlation signal;

the second filtering module is electrically connected with the relevant module and used for filtering the relevant signals to obtain envelope signals of the relevant signals;

and the distance measuring module is electrically connected with the second filtering module and used for carrying out peak value detection on the envelope signal and determining the distance by using the peak value obtained by detection.

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

In a possible implementation manner, the first filtering module includes a decimation filter for performing band-pass filtering and decimation on the digital ultrasonic signal.

In one possible implementation, the correlation module is a single-bit correlator.

In a possible implementation, the second filtering module comprises a low-pass filter for low-pass filtering 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:

and 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.

In a possible implementation, the ranging module further includes:

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 data.

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 embodiment of the utility model directly carries out analog-to-digital conversion on the ultrasonic signals by utilizing the analog-to-digital conversion module, outputs the single bit code stream with high speed, then obtaining a digital echo signal after band-pass filtering and extraction, then carrying out correlation operation on the digital echo signal by utilizing the known polarity of a preset transmitting signal to obtain a correlation signal, then filtering the correlation signal to obtain an envelope signal of the correlation signal, the distance measuring module can be used for value detection to obtain the distance, because the related operation has a single-bit polar signal to participate in the operation, therefore, no complex multiplier is needed, the correlation operation can be completed by using a simple adder unit, the complexity of the circuit is reduced, the circuit area and the power consumption are reduced, and the structure for completing the related ranging in the passband can have certain tolerance to the carrier frequency offset, and the computational complexity of the correlator is reduced.

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.

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, improve the stability of device, environmental suitability and reduce the circuit complexity.

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 of a single-bit code stream, where the analog ultrasonic signal is from an ultrasonic sensor, and a pass band range of the analog-to-digital conversion module is determined according to a bandwidth of the ultrasonic sensor;

the first filtering module 20 is electrically connected to the analog-to-digital conversion module 10, and is configured to filter and extract the digital ultrasonic signal to obtain a digital echo signal;

the correlation module 30, electrically connected to the first filtering module 20, includes an adder unit, and is configured to perform correlation operation on the polarity of a preset transmitting signal and the digital echo signal by using the adder unit to obtain a correlation signal;

the second filtering module 40 is electrically connected to the correlation module 30, and is configured to filter the correlation signal to obtain an envelope signal of the correlation signal;

and the distance measuring module 50 is electrically connected to the second filtering module 40, and is configured to perform peak detection on the envelope signal and determine a distance by using a detected peak value.

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 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 for analog-to-digital conversion.

In one possible implementation, the analog-to-digital conversion module may include an analog-to-digital converter (ADC) that may be configured 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 received is far greater than envelope signal's bandwidth to can set up analog to digital ultrasonic signal that analog to digital converter exported the single bit code stream, can reduce analog to digital converter ADC's area and consumption.

In one example, the decimation filter may be a Finite Impulse Response (FIR) filter, and the decimation filter may be used to decimate and bandpass filter the digital ultrasonic signal at a reduced sampling rate to obtain the digital echo signal.

Because the embodiment of the utility model provides a set up the digital ultrasonic signal of analog-to-digital converter output single bit code stream, therefore relevant module can realize relevant operation through the single bit correlator that realizes including the addition unit, does not need extra multiplier, and on the one hand, the realization mode is simple, and the circuit complexity is not high, realizes easily, and the cost is lower; on the other hand, because the correlator accomplishes single bit correlation operation at the passband, compare and handle in the correlation technique at the baseband, can save down the conversion module, through above device, the embodiment of the utility model provides a both can tolerate the carrier frequency deviation influence of certain degree, does not reduce the precision of range finding again.

In a possible implementation, the second filtering module may include a low-pass filter for low-pass filtering the correlation signal.

The embodiment of the utility model provides a can carry out low pass filtering to the relevant signal that relevant module obtained through low pass filter to obtain accurate envelope signal.

The embodiment of the present invention does not limit the specific implementation manner of the low-pass filter, and those skilled in the art can adopt the low-pass filter in the related art as needed.

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 one possible implementation, the peak detection unit further includes:

In one example, the peak storage subunit may comprise any type or combination of volatile or non-volatile storage 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.

In a possible implementation, the ranging module further includes:

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

The utility model discloses range unit has following advantage: the correlation technique is realized at the baseband and is surveyed, and the embodiment of the utility model provides a ranging device accomplishes the correlation ranging at the passband, has both saved down the frequency conversion operation, combines with band-pass Sigma-Delta ADC again, can use the adder to accomplish correlation operation, realizes correlation operation through utilizing the adder, no longer needs the multiplier in the correlator, can greatly reduce the computational resource of correlator like this, has reduced the circuit area and the consumption of receiver simultaneously. The ranging device with the structure can bear the influence of carrier frequency offset to a certain degree, and the ranging precision is not reduced.

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.

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 terms used herein were chosen in order to best explain the principles of the embodiments, the practical application, or technical improvements to the techniques 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 first filtering module comprises a decimation filter for performing bandpass filtering and decimation on the digital ultrasound signal.

4. The apparatus of claim 1, wherein the correlation module is a single-bit correlator.

5. The apparatus of claim 1, wherein the second filtering module comprises a low pass filter for low pass filtering the correlation signal.

6. 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:

7. The apparatus of claim 6, wherein the peak detection unit further comprises:

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

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

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

a ranging apparatus as claimed in any of claims 1 to 8.

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

a receiver as claimed in claim 9.