KR20150076870A - Apparatus for compensating the output of ultrasonic sensor - Google Patents

Apparatus for compensating the output of ultrasonic sensor Download PDF

Info

Publication number
KR20150076870A
KR20150076870A KR1020130165542A KR20130165542A KR20150076870A KR 20150076870 A KR20150076870 A KR 20150076870A KR 1020130165542 A KR1020130165542 A KR 1020130165542A KR 20130165542 A KR20130165542 A KR 20130165542A KR 20150076870 A KR20150076870 A KR 20150076870A
Authority
KR
South Korea
Prior art keywords
frequency
transmission
signal
transducer
compensation
Prior art date
Application number
KR1020130165542A
Other languages
Korean (ko)
Inventor
반재원
곽미정
정효은
Original Assignee
만도헬라일렉트로닉스(주)
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 만도헬라일렉트로닉스(주) filed Critical 만도헬라일렉트로닉스(주)
Priority to KR1020130165542A priority Critical patent/KR20150076870A/en
Publication of KR20150076870A publication Critical patent/KR20150076870A/en

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
    • G01S15/88—Sonar systems specially adapted for specific applications
    • G01S15/93—Sonar systems specially adapted for specific applications for anti-collision purposes
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/497—Means for monitoring or calibrating
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/52—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S15/00
    • G01S7/523—Details of pulse systems
    • G01S7/524—Transmitters

Landscapes

  • Engineering & Computer Science (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Physics & Mathematics (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • General Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)

Abstract

An output compensation device for an ultrasonic sensor is disclosed. An output compensation apparatus of an ultrasonic sensor according to an embodiment of the present invention includes a transducer section for receiving a transmission signal and for transmitting an ultrasonic wave having a transmission frequency oscillated at a resonance frequency by a transmission signal, A transmission signal having a driving frequency is provided to the duo part and a current signal including a transmission frequency is fed back from the transducer part so as to compensate for the resonance frequency variation of the transducer part, And a signal processing unit for changing the driving frequency of the transmission signal so that the frequency of the transmission signal has a frequency value corresponding to the transmission frequency of the current signal fed back.

Description

TECHNICAL FIELD [0001] The present invention relates to an output compensating device for an ultrasonic sensor,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an output compensation device for an ultrasonic sensor, and more particularly to an output compensation device for an ultrasonic sensor for detecting a distance to an object around the vehicle using ultrasonic waves.

Generally, the vehicle is provided with an ultrasonic sensor for detecting the presence or absence of an object located in the vicinity and the distance to the object.

The ultrasonic sensor transmits ultrasonic waves using a transducer having a piezoelectric element, receives the reflected wave reflected by the object, and detects the distance to the object according to the time from the ultrasonic transmission to the reception of the reflected wave. At this time, the transducer converts the electric signal into the acoustic signal by the piezoelectric element.

Since the transducer of the ultrasonic sensor oscillates at a specific resonance frequency and transmits ultrasonic waves, it is necessary to drive the transmission circuit at an optimum driving frequency suitable for the resonance frequency and supply the transmission signal to the transducer in order to obtain sufficient detection sensitivity.

However, the resonance frequency of the transducer of the ultrasonic sensor may be changed according to the ambient temperature change. The detection accuracy of the ultrasonic sensor may be deteriorated due to the fluctuation of the resonance frequency.

In order to improve the detection accuracy of the ultrasonic sensor, researches on compensating the resonance frequency fluctuation of the transducer due to the temperature change have been demanded by appropriately changing the driving frequency of the transmission circuit.

According to an embodiment of the present invention, there is provided an output compensation device for an ultrasonic sensor that changes a driving frequency by using an actual transmission frequency of a transducer to compensate for a resonance frequency variation of the transducer.

According to an aspect of the present invention, there is provided a transducer comprising: a transducer for receiving a transmission signal and transmitting ultrasonic waves having a transmission frequency, the piezoelectric element oscillating at a resonant frequency by the received transmission signal; And a transducer for receiving the current signal including the transmission frequency from the transducer unit so as to compensate for a resonance frequency variation of the transducer unit, And a signal processing unit for changing a driving frequency of the transmission signal so that a driving frequency of the transmission signal provided to the ultrasonic sensor is equal to a frequency value corresponding to a transmission frequency of the feedback current signal .

The signal processing unit may include changing the driving frequency of the transmission signal so that the driving frequency of the transmission signal is equal to the transmission frequency of the feedback current signal.

The signal processing unit may compare the transmission frequency of the feedback current signal with the frequency of the transmission signal and change the driving frequency provided to the transducer unit according to the comparison result.

The signal processing unit receives a current signal fed back from the transducer unit and compares a transmission frequency of the input current signal with a driving frequency of a transmission signal provided to the transducer unit last time, A frequency comparator for outputting a signal corresponding to a difference between the driving frequencies; A compensation frequency calculator for calculating a compensation frequency for compensating for a resonance frequency variation of the transducer unit based on a difference between the transmission frequency and the driving frequency provided from the frequency comparator; A compensation frequency generator for generating a transmission signal having a compensation frequency calculated by the compensation frequency calculator; And a frequency output unit for outputting a transmission signal having the compensation frequency generated by the compensation frequency generation unit to the transducer unit.

According to the embodiment of the present invention, by changing the driving frequency provided to the transducer using the actual transmission frequency of the transducer, even if the resonance frequency of the transducer changes due to temperature or the like, the amount of change can be compensated, Can be improved.

Also, according to another embodiment of the present invention, the resonance frequency variation of the transducer can be compensated more simply and conveniently by changing the driving frequency provided to the transducer using the actual transmission frequency of the transducer.

FIG. 1 is a view for explaining an object around a vehicle in a vehicle equipped with an output compensation device of an ultrasonic sensor according to an embodiment of the present invention.
2 is a diagram for explaining that an output compensation apparatus of an ultrasonic sensor according to an embodiment of the present invention transmits and receives signals for object detection.
3 is a schematic control block diagram of an output compensation apparatus of an ultrasonic sensor according to an embodiment of the present invention.
4 is a view for explaining compensation of the resonance frequency variation of the transducer part due to the temperature change by changing the driving frequency in the output compensation device of the ultrasonic sensor according to the embodiment of the present invention.
5 is a schematic control block diagram of a signal processing unit of an output compensation apparatus of an ultrasonic sensor according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments described below are provided by way of example so that those skilled in the art will be able to fully understand the spirit of the present invention. The present invention is not limited to the embodiments described below, but may be embodied in other forms. In order to clearly explain the present invention, parts not related to the description are omitted from the drawings, and the width, length, thickness, etc. of the components may be exaggerated for convenience. Like reference numerals designate like elements throughout the specification.

The expression " and / or " is used herein to mean including at least one of the elements listed before and after. Also, the expression " coupled / connected " is used to mean either directly connected to another component or indirectly connected through another component. The singular forms herein include plural forms unless the context clearly dictates otherwise. Also, components, steps, operations and elements referred to in the specification as " comprises " or " comprising " refer to the presence or addition of one or more other components, steps, operations, elements, and / or devices.

FIG. 1 is a view for explaining an object around a vehicle in a vehicle equipped with an output compensating device of an ultrasonic sensor according to an embodiment of the present invention. FIG. 2 is a block diagram of an ultrasonic sensor according to an embodiment of the present invention. And the output compensation apparatus transmits and receives signals for object detection.

1 and 2, the ultrasonic sensor 10 is provided on at least one of the front, rear, and side of the vehicle. For example, the ultrasonic sensor 10 may be disposed on the rear bumper of the vehicle so as to be able to detect an object located behind the vehicle.

The ultrasonic sensor 10 forms a detection area of a dotted line. When an object is located in the detection area formed by the ultrasonic sensor 10, the ultrasonic sensor 10 transmits an ultrasonic signal having a frequency of a certain band, and the ultrasonic wave is reflected by the object and receives ultrasonic waves. In this way, the distance from the object can be detected by measuring the time from when the ultrasonic wave is transmitted to when it is reflected by the object, reflected, and returned as a reflected wave.

That is, the ultrasonic sensor 10 transmits an ultrasonic signal Wb having a frequency of a certain frequency through the ultrasonic element 11 provided in the case 11 and detects an object by receiving the reflected wave Wa by the object . Assuming that the time difference between the transmission wave Wb and the reception wave Wa is T [sec], the inter-vehicle distance is L [m], and the sound velocity is C [m / sec] Can be expressed as the following equation [1].

Da = (T / 2) x C Equation [1]

In this way, the distance between the ultrasonic sensor 10 and the object is detected by measuring the time from the transmission of the ultrasonic signal to the return of the ultrasonic sensor 10 to the object . For example, when the object is close to the ultrasonic sensor 10, the time that the ultrasonic signal returns to the reflected wave is shortened, and when the object is far away, the time that the ultrasonic signal returns to the reflected wave becomes long. can do.

3 is a schematic control block diagram of an output compensation apparatus of an ultrasonic sensor according to an embodiment of the present invention.

Referring to FIG. 3, the output compensation apparatus of the ultrasonic sensor includes a signal processing unit 20, a transformer unit 30, and a transducer unit 40.

The signal processing unit 20 performs overall control of the ultrasonic sensor 10. The signal processing unit 20 may be a micro controller unit (MCU).

The signal processing section 20 may include, for example, a memory for storing data and a program necessary for signal processing, and an internal timer serving as a time lapse reference.

The signal processing unit 30 outputs a transmission signal having a driving frequency.

The transformer section (30) boosts the transmission signal transmitted by the signal processing section and outputs it.

The transformer unit 30 receives a clock signal of a driving frequency set by the signal processing unit, amplifies the received clock signal, and outputs a transmission signal having a predetermined voltage and amplitude.

The transducer unit 40 is driven by a transmission signal provided from the transformer unit 30 to transmit ultrasonic waves.

The transducer section 40 includes an ultrasonic element 12 which is a piezoelectric element. This piezoelectric element has a natural vibration corresponding to the shape and the dimension. Therefore, when the frequency of the applied voltage is matched with this natural vibration, resonance is produced. When the piezoelectric element is vibrated at the resonance frequency, a large vibration width can be obtained.

As described above, the transducer section 40 transmits ultrasonic waves by oscillating at a resonance frequency inherent to the transmission signal supplied from the transformer section 30 by the piezoelectric element.

The transmission frequency of the ultrasonic wave transmitted from the transducer 40 is influenced by, for example, the resonance frequency fluctuation due to the temperature change. This change in temperature changes the length of the piezoelectric element or the like of the transducer. The resonance frequency of the piezoelectric element is determined by the mechanical shape. As a result, this change in temperature causes the resonance frequency of the piezoelectric element to fluctuate. Generally, as the temperature increases, the length increases and the resonance frequency decreases. As the temperature decreases, the length decreases and the resonance frequency increases. That is, even though the driving frequency of the transmission signal provided to the transducer unit 30 is constant, the transmission frequency of the ultrasonic wave actually transmitted may vary due to the variation of the resonance frequency due to the temperature change.

In order to prevent this, the signal processing unit 30 feeds back the current signal including the transmission frequency from the transducer unit 40 so as to compensate for the resonance frequency variation of the transducer unit 40, So that the frequency is changed. For example, the signal processing section 30 receives the current signal including the transmission frequency from the transducer section 40, compares the transmission frequency of the fed-back current signal with the drive frequency outputted last time, ), Generates the calculated compensation frequency, changes the drive frequency to the generated compensation frequency, and provides the compensated frequency to the transducer unit 40 via the transformer unit 30 do.

4 is a view for explaining compensation of the resonance frequency variation of the transducer part due to the temperature change by changing the driving frequency in the output compensation device of the ultrasonic sensor according to the embodiment of the present invention.

Referring to FIG. 4, it can be seen that the frequency trajectory of the impedance, that is, the frequency characteristic of the impedance is affected by the temperature. That is, assuming that the temperatures T1 and T2 have different temperature values, the frequency characteristic curve R_T2 of the impedance at the temperature T2 and the frequency characteristic curve R_T1 of the impedance at the temperature T1 have different frequency characteristics I have.

In general, the resonance frequency of the ultrasonic element 12 of the transducer 40 is a frequency value whose impedance is the minimum value (Zmin) at the reference temperature in the frequency characteristic curve of the impedance.

Therefore, when the temperature changes, the frequency characteristic of the impedance changes, and as a result, the resonance frequency of the ultrasonic element 12 fluctuates. To solve this problem, it is necessary to change the driving frequency in accordance with the fluctuation of the resonance frequency.

Referring again to Fig. 4, when the temperature changes from T2 to T1, the frequency characteristic curve of impedance is changed from R_T2 to R_T1. As the frequency characteristic curve of the impedance is changed, the resonance frequency of the ultrasonic element 12 is changed from P to Q on the basis of the minimum value Zmin of the impedance.

Therefore, by changing the drive frequency from ATF2 to ATF1, it is possible to compensate for the resonance frequency fluctuation of the ultrasonic element 12. [

Hereinafter, the operation of the signal processing unit 20 will be described in more detail.

5 is a schematic control block diagram of a signal processing unit of an ultrasonic sensor according to an embodiment of the present invention.

5, the signal processing unit 20 includes a frequency comparator 21, a compensation frequency calculator 22, a compensation frequency generator 23 and a frequency output unit 24.

The operations of the frequency comparator 21, the compensation frequency calculator 22, the compensation frequency generator 23 and the frequency output unit 24, which are components of the signal processor 30, .

The frequency comparator 21 receives the current signal fed back from the transducer 40 and compares the transmit frequency of the input current signal with the drive frequency of the transmit signal supplied to the transformer 20 last time. The frequency comparator 21 outputs a signal corresponding to the difference between the transmission frequency and the drive frequency to the compensation frequency calculator 22.

The compensation frequency calculating unit 22 calculates a compensation frequency for compensating for the resonance frequency variation of the transformer unit 40 on the basis of the difference between the transmission frequency and the driving frequency.

The compensation frequency generating section 23 generates a transmission signal having the compensation frequency calculated by the compensation frequency calculating section 22. [

The frequency output unit 24 outputs the transmission signal having the compensation frequency generated by the compensation frequency generating unit 23 to the transformer unit 30. [ At this time, the compensation frequency generator 23 and the frequency output unit 24 may be integrated into one component as needed.

As described above, the signal processing unit 20 uses the actual transmission frequency of the transducer to change the driving frequency provided to the transducer, so that even if the resonance frequency of the transducer changes due to temperature or the like, the amount of the change can be more simply and conveniently compensated So that the detection accuracy of the ultrasonic sensor can be improved.

10: ultrasonic sensor 20: signal processor
21: Frequency comparison unit 22: Compensation frequency calculation unit
23: Compensation frequency generating section 24: Frequency output section

Claims (4)

A transducer for receiving a transmission signal and for transmitting an ultrasonic wave having a transmission frequency, the piezoelectric element oscillating at a resonant frequency by the received transmission signal; And
The transducer unit is provided with the transmission signal having a driving frequency and receives a current signal including the transmission frequency from the transducer unit so as to compensate for a resonance frequency variation of the transducer unit, And a signal processing unit for changing a driving frequency of the transmission signal so that the driving frequency of the transmission signal provided has a frequency value corresponding to the transmission frequency of the feedback current signal. The method according to claim 1,
Wherein the signal processing unit changes the driving frequency of the transmission signal so that the driving frequency of the transmission signal coincides with the transmission frequency of the feedback current signal. The method according to claim 1,
Wherein the signal processing unit compares the transmission frequency of the feedback current signal with the frequency of the transmission signal and changes the driving frequency provided to the transducer unit according to the comparison result. The method of claim 3,
The signal processing unit,
And a controller for comparing a transmission frequency of the input current signal with a drive frequency of a transmission signal provided to the transducer section at a previous time, A frequency comparator for outputting a signal to be output;
A compensation frequency calculator for calculating a compensation frequency for compensating a resonance frequency variation of the transducer unit based on a difference between the transmission frequency and the driving frequency provided from the frequency comparator;
A compensation frequency generator for generating a transmission signal having a compensation frequency calculated by the compensation frequency calculator; And
And a frequency output unit for outputting a transmission signal having a compensation frequency generated by the compensation frequency generation unit to the transducer unit.
KR1020130165542A 2013-12-27 2013-12-27 Apparatus for compensating the output of ultrasonic sensor KR20150076870A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020130165542A KR20150076870A (en) 2013-12-27 2013-12-27 Apparatus for compensating the output of ultrasonic sensor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020130165542A KR20150076870A (en) 2013-12-27 2013-12-27 Apparatus for compensating the output of ultrasonic sensor

Publications (1)

Publication Number Publication Date
KR20150076870A true KR20150076870A (en) 2015-07-07

Family

ID=53789748

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020130165542A KR20150076870A (en) 2013-12-27 2013-12-27 Apparatus for compensating the output of ultrasonic sensor

Country Status (1)

Country Link
KR (1) KR20150076870A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101878435B1 (en) * 2017-12-11 2018-07-13 한국생산기술연구원 A System and a Method for Monitoring a Fish Farm under Water Using Scanning Sonar with Variable Frequency
KR20190083407A (en) * 2018-01-04 2019-07-12 재단법인 다차원 스마트 아이티 융합시스템 연구단 Ultrasound system capable of transmitting/receiving and the method thereof

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101878435B1 (en) * 2017-12-11 2018-07-13 한국생산기술연구원 A System and a Method for Monitoring a Fish Farm under Water Using Scanning Sonar with Variable Frequency
KR20190083407A (en) * 2018-01-04 2019-07-12 재단법인 다차원 스마트 아이티 융합시스템 연구단 Ultrasound system capable of transmitting/receiving and the method thereof

Similar Documents

Publication Publication Date Title
US10234549B2 (en) Circuit for acoustic distance time of flight compensation
EP2381271B1 (en) Self-tuning acoustic measurement system
US11555922B2 (en) Object detection device
US10677902B2 (en) Excitation interval for ultrasonic transducer
CN103995483B (en) A kind of control method, device and system of ultrasonic transducer
US6788296B2 (en) Coordinate data entry device
WO2009028591A1 (en) Ultrasonic wave propagation time measuring system
US11833543B2 (en) Ultrasonic apparatus
KR101604762B1 (en) Apparatus for controlling ultrasonic sensor and control method thereof
KR20150076870A (en) Apparatus for compensating the output of ultrasonic sensor
JPH1054872A (en) Ultrasonic distance meter
KR20070066136A (en) Method and apparatus for measuring of minimum distance using a ultrasonic
JP2012220434A (en) Object detecting device
JP5862773B2 (en) Ultrasonic transmitter and ultrasonic sensor device
JP2017075841A (en) Object detection device and object detection method
KR100807843B1 (en) Transmitter for TPMS
KR101937262B1 (en) Ultrasonic sensor device and method therefor
CN112805589A (en) Object detection device
JP2016138850A (en) Liquid level detector
JP2000035357A (en) Ultrasonic level gage
JP5884047B2 (en) Ultrasonic sensor
JP2011030755A (en) Non-contact ultrasonic tonometer
JP2006349581A (en) Periphery monitoring apparatus for vehicle
JPH0694833A (en) Ultrasonic distance measuring device
KR101603225B1 (en) Method for detecting wrong assembly of ultrasonic sensor and control method thereof

Legal Events

Date Code Title Description
A201 Request for examination
E902 Notification of reason for refusal
E601 Decision to refuse application