CN212301882U - Distance measuring device and terminal - Google Patents
Distance measuring device and terminal Download PDFInfo
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- CN212301882U CN212301882U CN202021662180.7U CN202021662180U CN212301882U CN 212301882 U CN212301882 U CN 212301882U CN 202021662180 U CN202021662180 U CN 202021662180U CN 212301882 U CN212301882 U CN 212301882U
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Abstract
The utility model relates to a distance measuring device and a terminal, the device comprises an analog-to-digital conversion module, which is used for carrying out band-pass sampling on received analog ultrasonic signals and carrying out analog-to-digital conversion on the sampled signals to obtain digital ultrasonic signals; the frequency doubling module is electrically connected with the analog-to-digital conversion module and is used for performing frequency doubling processing on the digital ultrasonic signals to obtain frequency doubling signals; the filtering module is electrically connected with the frequency doubling module and used for filtering the frequency doubling signal to obtain an envelope signal; the correlation module is electrically connected with the filtering module and is used for performing correlation processing on the envelope signal and a preset envelope 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. By adopting the device for ranging, the influence of carrier frequency offset is eliminated, and the ranging precision is improved.
Description
Technical Field
The utility model relates to a measure technical field, especially relate to a range unit 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
Technical problem
In view of this, the technical problem to be solved by the present invention is how to improve the precision of ultrasonic distance measurement.
Solution scheme
In order to solve the above technical problem, according to the utility model discloses an embodiment provides a distance measuring device, 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 frequency doubling module is electrically connected with the analog-to-digital conversion module and is used for performing frequency doubling processing on the digital ultrasonic signals to obtain frequency doubling signals;
the filtering module is electrically connected with the frequency doubling module and used for filtering the frequency doubling signal to obtain an envelope signal;
the correlation module is electrically connected with the filtering module and is used for performing correlation processing on the envelope signal and a preset envelope 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 embodiment, the analog-to-digital conversion module comprises an analog-to-digital converter arranged to operate in Sigma-Delta mode.
In one possible embodiment, the frequency multiplication module comprises a multiplier.
In a possible implementation, the filtering module comprises a low-pass filter.
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:
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.
To solve the technical problem, according to another embodiment of the present invention, there is provided a terminal, including:
the distance measuring device.
Advantageous effects
Through above device, the embodiment of the utility model provides a can utilize the analog-to-digital conversion module to carry out the band-pass sampling to received analog ultrasonic signal to carry out analog-to-digital conversion with the signal that the sampling obtained, obtain digital ultrasonic signal, it is right to utilize the frequency doubling module digital ultrasonic signal carries out the frequency doubling and handles, obtains the frequency doubling signal, and is right through the filtering module the frequency doubling signal filters, obtains envelope signal, utilizes relevant module will envelope signal carries out correlation processing with presetting envelope signal, obtains relevant signal, utilizes ranging module right relevant signal carries out peak detection to the peak value that the utilization detected and obtains confirms the distance. By adopting the device for ranging, the influence of carrier frequency offset is eliminated, and the ranging precision is improved.
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, 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 frequency doubling module 20 is electrically connected to the analog-to-digital conversion module 10 and is used for performing frequency doubling processing on the digital ultrasonic signal to obtain a frequency doubling signal;
the filtering module 30 is electrically connected to the frequency doubling module 20 and is configured to filter the frequency doubled signal to obtain an envelope signal;
the correlation module 40 is electrically connected to the filtering module 30, and is configured to perform correlation processing on the envelope signal and a preset envelope signal to obtain a correlation signal;
and the ranging module 50 is electrically connected to the correlation module 40, and is configured to perform peak detection on the correlation signal and determine a distance by using a detected peak value.
Through above device, the embodiment of the utility model provides a can utilize the analog-to-digital conversion module to carry out the band-pass sampling to received analog ultrasonic signal to carry out analog-to-digital conversion with the signal that the sampling obtained, obtain digital ultrasonic signal, it is right to utilize the frequency doubling module digital ultrasonic signal carries out the frequency doubling and handles, obtains the frequency doubling signal, and is right through the filtering module the frequency doubling signal filters, obtains envelope signal, utilizes relevant module will envelope signal carries out correlation processing with presetting envelope signal, obtains relevant signal, utilizes ranging module right relevant signal carries out peak detection to the peak value that the utilization detected and obtains confirms the distance. By adopting the device for ranging, the influence of carrier frequency offset is eliminated, and the ranging precision is improved.
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 embodiment, the frequency doubling module may include a multiplier.
In one example, the frequency multiplier module may be implemented by a multiplier, and may also be implemented by a frequency multiplier in the related art.
Through frequency doubling module, the embodiment of the utility model provides a can realize digital ultrasonic signal's square operation. Adopt frequency multiplier, multiplier to realize the doubling of frequency module, it is less to the circuit area increase of device, can ignore, the bandwidth of the envelope signal that the module of doubling of frequency was drawed has compared in original bandwidth and has increased one time, combines to work in sigma-delta mode's analog-to-digital converter, has realized the carrier synchronization, makes the utility model discloses range unit's performance does not receive the influence of carrier frequency deviation.
In a possible implementation, the filtering module may comprise a low-pass filter.
The embodiment of the utility model provides a can carry out low pass filtering to the frequency doubling signal that frequency doubling module obtained through low pass filter to obtain accurate envelope signal, just, because the frequency doubling effect of frequency doubling module, low pass filter is wideer to the bandwidth of the envelope signal that obtains after the frequency doubling signal low pass filtering, can improve the range finding precision.
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 possible implementation, the correlation module may include 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 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 a possible implementation, the ranging module may include a peak detection unit, and the peak detection unit may be configured to perform peak detection on the correlation signal, including:
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 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:
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 one example, the peak storage subunit may include a non-volatile memory.
In a possible implementation, the ranging module may further include:
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.
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 by a dedicated hardware circuit (e.g., a digital circuit), or may be implemented by a general-purpose hardware circuit (e.g., a Central Processing Unit (CPU), a Microprocessor (MCU), etc.) in combination with existing control logic.
The embodiment of the utility model provides a frequency multiplier can realize with the multiplier that has realized that the carrier wave is synchronous, and the circuit area that increases can be ignored. The bandwidth of the envelope signal that draws through the frequency multiplier can be than original broadening one time, just the utility model discloses the analog-to-digital converter ADC who adopts in the device that provides is worked in Sigma-Delta mode, and the signal rate after the extraction filtering is still far more than including the bandwidth of signal promptly, and this make full use of Sigma-Delta mode ADC and these characteristics between them of frequency multiplier for the performance of range unit is not influenced by carrier frequency offset, does not reduce the precision of range finding again, and the cost is lower.
Referring to fig. 3, fig. 3 is a block diagram of a distance measuring device 800 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.
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.
The above description is only for the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present invention, and all should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (9)
1. A ranging apparatus, the apparatus comprising:
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 frequency doubling module is electrically connected with the analog-to-digital conversion module and is used for performing frequency doubling processing on the digital ultrasonic signals to obtain frequency doubling signals;
the filtering module is electrically connected with the frequency doubling module and used for filtering the frequency doubling signal to obtain an envelope signal;
the correlation module is electrically connected with the filtering module and is used for performing correlation processing on the envelope signal and a preset envelope 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.
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 frequency doubling module comprises a multiplier.
4. The apparatus of claim 1, wherein the filtering module comprises a low pass filter.
5. The apparatus of claim 1, wherein the correlation module comprises 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.
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:
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.
7. The apparatus of claim 6, wherein the peak detection unit further comprises:
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.
8. The apparatus of claim 6, wherein the ranging module further comprises:
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.
9. A terminal, characterized in that the terminal comprises:
a device as claimed in any one of claims 1 to 8.
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| CN112863094A (en) * | 2021-02-04 | 2021-05-28 | 西南交通大学 | Railway protective net intrusion alarm system and working method thereof |
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| CN112863094A (en) * | 2021-02-04 | 2021-05-28 | 西南交通大学 | Railway protective net intrusion alarm system and working method thereof |
| CN112863094B (en) * | 2021-02-04 | 2022-10-21 | 西南交通大学 | Railway protective net intrusion alarm system and working method thereof |
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