WO2016047204A1 - Ultrasonic detection device - Google Patents

Ultrasonic detection device Download PDF

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Publication number
WO2016047204A1
WO2016047204A1 PCT/JP2015/065505 JP2015065505W WO2016047204A1 WO 2016047204 A1 WO2016047204 A1 WO 2016047204A1 JP 2015065505 W JP2015065505 W JP 2015065505W WO 2016047204 A1 WO2016047204 A1 WO 2016047204A1
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WO
WIPO (PCT)
Prior art keywords
ultrasonic
sensor
transmission
ultrasonic sensor
diagnostic
Prior art date
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PCT/JP2015/065505
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French (fr)
Japanese (ja)
Inventor
達朗 黒田
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シャープ株式会社
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Publication date
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Publication of WO2016047204A1 publication Critical patent/WO2016047204A1/en

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    • 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
    • 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
    • G01S7/521—Constructional features

Definitions

  • the present invention relates to an ultrasonic detector provided with an ultrasonic sensor.
  • ultrasonic sensors have been used for distance measurement and obstacle detection.
  • the ultrasonic sensor cannot measure distances or detect obstacles if deposits such as dust and dirt accumulate on the ultrasonic transmission surface and reception surface (which may be used in some cases).
  • an outdoor ultrasonic sensor may have a sound absorber such as mud or snow attached to a transmission surface or a reception surface.
  • Patent Document 2 in the vehicle obstacle detection device, when it is determined that the ambient environment temperature is not low, it is determined whether or not the duration of the reverberation vibration represents a failure state of the ultrasonic transducer, A technique for determining whether or not the duration of reverberation vibration represents a frozen state of a vibration surface when it is determined that the environmental temperature is low is disclosed.
  • Patent Document 3 discloses a system in which ultrasonic sensors as obstacle sensors are provided at a plurality of locations on a moving body, and obstacles existing around the moving body are detected by transmitting and receiving signals from these obstacle sensors. .
  • each obstacle sensor is divided into a plurality of groups and operated at different timings for each group, and for each obstacle sensor, an ultrasonic signal transmitted from the transmission unit and directly around the reception unit is detected.
  • the obstacle sensor with detection is recognized as normal, and the obstacle sensor without detection is recognized as abnormal.
  • Patent Document 4 discloses an ultrasonic diagnostic apparatus that sends an ultrasonic wave from a probe to a subject and receives a return echo signal to diagnose the subject.
  • a technique for performing a self-diagnosis and detecting a failure or abnormality of a hardware element is disclosed.
  • the ultrasonic sensor cannot measure distances or detect obstacles if there are any deposits on the ultrasonic transmission surface or reception surface. Therefore, when the ultrasonic sensor is used as a safety confirmation sensor such as a collision detection application, the detection result is unreliable.
  • the distance can be obtained from the time from oscillating the ultrasonic wave until returning, and the speed of sound.
  • the ultrasonic sensor for obstacle detection when the ultrasonic wave is returned, the obstacle exists within the range that can be detected by the ultrasonic sensor, and when the ultrasonic wave does not return, the range is within that range. It is determined that there are no obstacles.
  • the present invention has been made in view of the above-described actual situation, and the purpose thereof is a result of detecting a detection result by a reflection type ultrasonic sensor in a state in which no deposit is present on the ultrasonic transmission surface. In such a case, it is an object of the present invention to provide an ultrasonic detection device capable of guaranteeing that.
  • a first technical means of the present invention is an ultrasonic wave including a reflection type ultrasonic sensor having a transmission unit that transmits ultrasonic waves and a first reception unit that receives the ultrasonic waves.
  • a detection device further comprising a diagnostic ultrasonic sensor in the vicinity of the ultrasonic transmission surface in the transmission unit, wherein the diagnostic ultrasonic sensor receives an ultrasonic wave transmitted from the ultrasonic transmission surface. 2 receivers are provided, and the presence or absence of an adhering substance adhering to the ultrasonic transmission surface is detected based on the reception result at the second receiver.
  • the diagnostic ultrasonic sensor has a receiving surface for receiving ultrasonic waves transmitted from the ultrasonic transmission surface with respect to the ultrasonic transmission surface. It is characterized by being arranged so as to be substantially vertical.
  • the ultrasonic receiving surface of the first receiving unit is a surface common to the ultrasonic transmitting surface. is there.
  • the sonic sensor further includes a horn attached to the ultrasonic sensor, and the receiving surface of the diagnostic ultrasonic sensor includes the horn. It is characterized by being attached to.
  • a horn attached to the ultrasonic sensor and an inner peripheral surface or an outer peripheral surface of the horn are circulated, And a vibration transmitting body for transmitting ultrasonic vibration from the sound wave transmitting surface to the receiving surface of the diagnostic ultrasonic sensor.
  • the horn further includes a horn attached to the ultrasonic sensor, and the horn has a recess in a part of an inner peripheral surface thereof.
  • the diagnostic ultrasonic sensor is attached so that a receiving surface of the diagnostic ultrasonic sensor is located in the recess and faces the inner peripheral surface.
  • the ultrasonic detection device of the present invention when the detection result of the reflection type ultrasonic sensor is a result of detection in a state where there is no deposit on the ultrasonic transmission surface, this is guaranteed. be able to.
  • FIG. 1B is a block diagram showing an example of the configuration of the ultrasonic detection apparatus in FIG. 1A.
  • FIG. It is a figure which shows the circuit structural example of the ultrasonic detection apparatus of FIG. 2A. It is a figure for demonstrating the example of a process at the time of normal operation
  • FIG. 1A It is a block diagram which shows the other structural example of the ultrasonic detection apparatus of FIG. 1A. It is a figure which shows the circuit structural example of the ultrasonic detection apparatus of FIG. 4A. It is a figure for demonstrating the example of a process at the time of normal operation
  • FIG. 10A It is a schematic sectional drawing which shows one structural example of the ultrasonic detection apparatus which concerns on the 3rd Embodiment of this invention. It is a figure for demonstrating the example of a process in the ultrasonic detection apparatus which concerns on the 4th Embodiment of this invention. It is a figure for demonstrating the example of a process in the ultrasonic detection apparatus which concerns on the 5th Embodiment of this invention. It is a block diagram which shows the example of 1 structure of the ultrasonic detector which concerns on 6th Embodiment relevant to this invention. It is a figure which shows the circuit structural example of the ultrasonic detection apparatus of FIG. 10A.
  • the ultrasonic detection apparatus has a diagnostic ultrasonic sensor separately provided in the vicinity of an ultrasonic transmission surface in a reflection type ultrasonic sensor used for distance measurement, obstacle detection, and the like.
  • FIG. 1A is a schematic diagram illustrating a configuration example of the ultrasonic detection apparatus according to the first embodiment of the present invention, and FIG. is there.
  • the ultrasonic detection device 1 includes an ultrasonic sensor 11.
  • FIG. 1A schematically shows a state in which ultrasonic waves are transmitted.
  • the ultrasonic sensor 11 is a reflection type ultrasonic sensor having a transmission unit that transmits ultrasonic waves and a reception unit (hereinafter referred to as a first reception unit) that receives the ultrasonic waves (including reflected waves). is there.
  • the ultrasonic detection apparatus 1 includes a diagnostic ultrasonic sensor (hereinafter simply referred to as a diagnostic sensor) 13 in the vicinity of the ultrasonic transmission surface (surface of the oscillation element) in the transmission unit as a main feature. .
  • the diagnostic sensor 13 includes a receiving unit (hereinafter referred to as a second receiving unit) that receives ultrasonic waves (including reflected waves) transmitted from the ultrasonic transmission surface.
  • the diagnostic sensor 13 is a sensor of a different system from the ultrasonic sensor 11, and detects the vibration caused by the ultrasonic wave from the main ultrasonic sensor 11, that is, monitors the oscillation of the ultrasonic sensor 11. Thus, the ultrasonic sensor 11 is diagnosed. Therefore, the diagnostic sensor 13 is a reception-only sensor.
  • the diagnostic sensor 13 detects the presence or absence of the deposit
  • the measured value in the 1st receiving part of the ultrasonic sensor 11 is employ
  • discarding it is preferable to notify error information or the like to the outside.
  • the ultrasonic detection apparatus 1 illustrated in FIGS. 1A and 1B includes a horn 12 attached to the ultrasonic sensor 11, and a receiving surface of the diagnostic sensor 13 is attached to the horn 12.
  • the horn 12 is a member for improving the sound collecting property and directivity and increasing the detection distance.
  • the shape and material of the horn 12 are not limited as long as the sound collecting property and directivity can be improved.
  • a material such as die steel is used.
  • the horn 12 is preferably formed in a size such that the half wavelength of the ultrasonic wave to be transmitted is a basic unit in order to efficiently transmit vibration energy.
  • the diagnostic sensor 13 is preferably provided on the inner peripheral surface (surface) of the horn 12 because the sensitivity is improved.
  • the diagnostic sensor 13 is provided on the outer peripheral surface of the horn 12, It may be embedded inside.
  • the horn 12 is not provided, for example, the ultrasonic sensor 11 is provided on the bottom of a quadrangular prism-shaped recess, and the diagnostic sensor 13 is provided on the side wall of the recess.
  • the ultrasonic wave transmitted by the ultrasonic sensor 11 is diagnosed by the diagnostic sensor 13 provided separately, and therefore the detection result by the reflective ultrasonic sensor 11 is detected.
  • this can be ensured when the result is detected in a state where no deposit is present on the ultrasonic transmission surface.
  • the diagnostic sensor 13 is disposed such that the reception surface that receives the ultrasonic waves transmitted from the ultrasonic transmission surface is substantially perpendicular to the ultrasonic transmission surface. It is preferable.
  • the ultrasonic sensor 11 when the ultrasonic sensor 11 is installed facing upward and deposits accumulate, ultrasonic waves from the ultrasonic sensor 11 cannot be detected by the diagnostic sensor 13. However, since the diagnostic sensor 13 is attached substantially perpendicularly to the oscillation direction of the ultrasonic sensor 11, the deposits do not accumulate structurally. For this reason, it is possible to reliably detect that the ultrasonic sensor 11 is not able to oscillate due to the adhered matter, rather than the diagnostic sensor 13 having the attached matter.
  • the diagnostic sensor 13 is disposed such that the receiving surface thereof is substantially perpendicular to the ultrasonic transmission surface, and thus deposits such as dust, dirt, snow and mud that accumulate on the ultrasonic sensor 11 accumulate. It is difficult to make the diagnostic sensor 13 function effectively for diagnosis.
  • the diagnostic sensor 13 accumulates on the ultrasonic transmission surface even if the reception surface is provided so as to make an angle with respect to the ultrasonic transmission surface (not provided at a position that interferes with the transmission of ultrasonic waves). It can be said that such deposits are difficult to accumulate.
  • FIGS. 2A to 3B are block diagram illustrating a configuration example of the ultrasonic detection apparatus of FIG. 1A
  • FIG. 2B is a diagram illustrating a circuit configuration example thereof.
  • FIGS. 3A and 3B are diagrams for explaining processing examples during normal operation and abnormal operation in the ultrasonic detection apparatus of FIG. 2B, respectively.
  • the ultrasonic sensor illustrated in FIG. 2A is a sensor configured by sharing an ultrasonic transmission surface and an ultrasonic reception surface, and includes a transmission / reception unit 11a that is a sensor element (piezoelectric body or the like) for ultrasonic transmission / reception. . That is, this sensor element is an element in which an oscillation element and a reception element are shared.
  • the transmitting / receiving unit 11 a is connected to an amplifier / comparator 14, and an MPU (Micro Processing Unit) 10 is connected to the amplifier / comparator 14 as an example of a control unit of the ultrasonic detection device 1. That is, the ultrasonic sensor 11 of FIG. 1A and the like includes the transmission / reception unit 11a and the amplifier / comparator 14 which are examples of the transmission unit and the first reception unit in the example of FIG.
  • the amplifier / comparator 14 includes an amplifier 14e used for transmission.
  • the MPU 10 generates a rectangular pulse signal in the vicinity of 40 kHz (period 25 ⁇ s), for example, and outputs the signal (transmission signal) to the amplifier 14e.
  • the amplifier 14e amplifies the transmission signal and outputs the amplified signal to the transmission / reception unit 11a. Thereby, in the transmission / reception part 11a, a sensor element vibrates and an ultrasonic wave like the signal Tx of FIG. 3A is output in the air.
  • the amplifier / comparator 14 includes an amplifier 14a, a rectifier circuit 14b, a comparator 14c, and a comparator reference voltage storage unit 14d used at the time of reception.
  • the storage unit 14d may be a memory, but may of course be configured with only a resistor or the like.
  • the transceiver 11a receives an ultrasonic reflected wave signal such as the signal Rx in FIG. 3A (senses the vibration of the sensor element) and outputs it to the amplifier 14a. Note that when the transmission signal Tx is transmitted, no reception process is performed, and therefore only the reflected wave is received.
  • the amplifier 14a amplifies it, makes it a signal like the signal Aout in FIG. 3A, and outputs it to the rectifier circuit 14b.
  • the rectifier circuit 14b converts the signal into a DC signal amplitude and outputs the signal to the comparator 14c.
  • the comparator 14c compares the input signal from the rectifier circuit 14b such as the signal Cin in FIG. 3A with the comparator reference voltage Th stored in the storage unit 14d. A digital high signal is output to the MPU 10 as an object is detected. The MPU 10 receives a pulse signal Cout as shown in FIG. 3A. Th is determined based on the signal level when there is no deposit.
  • the MPU 10 can measure the time from when the ultrasonic wave is transmitted until the reflected wave returns, and calculate the distance to the object.
  • the distance to the object is obtained by “sound speed” ⁇ “time taken from oscillation to reception”.
  • the MPU 10 may add such processing.
  • the comparator 14c outputs a digital low signal to the MPU 10 assuming that an object such as an obstacle has not been detected.
  • the diagnostic sensor 13 shown in FIG. 1A and the like includes the receiving unit 13a and the amplifier / comparator 15 in the example of FIG. 2A (which correspond to the example of the second receiving unit) and the MPU 10.
  • the receiving unit 13a is a sensor element for receiving ultrasonic waves.
  • the amplifier / comparator 15 has the same configuration as the amplifier / comparator 14, that is, an amplifier 15a, a rectifier circuit 15b, a comparator 15c, and a comparator reference voltage storage unit 15d.
  • the MPU 10 processes both the input from the comparator 14c and the input from the comparator 15c.
  • the receiving unit 13a receives the signal Rxd1 and also receives the signal Rxd2 as a reflected wave of the ultrasonic signal Tx.
  • the output of the amplifier 15a is Addout1, Addout2
  • the input of the comparator 15c is Cdin1, Cdin2
  • the output of the comparator 15c is Cdout1, Cdout2.
  • FIG. 3A shows an example in which there is no deposit and there is an object, and therefore, Cdout, Cdout1, and Cdout2 are all high. That is, when the vibration is equal to or higher than the comparator reference voltage Th, the comparator 15c outputs a digital high signal to the MPU 10 on the assumption that the ultrasonic wave from the transmission / reception unit 11a is normally detected, and the comparator 14c also outputs the signal Cin as Th. In the case above, the High signal is also output to the MPU 10. Note that the MPU 10 only needs to know that the ultrasonic wave can be detected from the output from the comparator 15c, and therefore it is not necessary to calculate the distance using this output.
  • the comparator 15c outputs a digital low signal to the MPU 10 assuming that no ultrasonic wave is detected.
  • the transmission / reception unit 11a receives a signal Rx having a smaller amplitude than that in FIG. 3A.
  • the output of the amplifier 14a and the input to the comparator 14c are also reduced, and do not exceed the comparator reference voltage Th.
  • the output signal Cout of the comparator 14c becomes Low. However, if the output signal Cout is only Low, it is not known whether there is an adhering object or there is no object or obstacle to be measured.
  • the receiving unit 13a receives signals Rxd1 and Rxd2 having a smaller amplitude than that in FIG. 3A.
  • the output of the amplifier 15a and the comparator 15c are output.
  • the input also becomes small, does not exceed the comparator reference voltage Th, and the output signals Cdout1 and Cdout2 of the comparator 15c become Low.
  • the output signals Cdout1 and Cdout are always High even when there is no object and the output signal Cout becomes Low.
  • the MPU 10 obtains High Cdout 1 and Cdout 2 when there is no deposit on the ultrasonic transmission surface of the ultrasonic sensor 11 (during normal operation), that is, the ultrasonic wave is transmitted from the ultrasonic sensor 11.
  • the diagnostic sensor 13 can observe the same ultrasonic wave as the ultrasonic sensor 11, and it can be assured that the reception result at the transmission / reception unit 11 a at that time is the one received without adhering matter. it can.
  • Cdout1 and Cdout2 are Low during the ultrasonic oscillation period, it is determined that the ultrasonic waves are not normally oscillated.
  • the second receiving unit has the same structure as the first receiving unit (the same example having a sensor element and an amplifier / comparator) is given.
  • the 2nd receiving part can detect an ultrasonic wave from the ultrasonic sensor 11 in the same state as the 1st receiving part.
  • a different structure may be adopted.
  • the oscillation element and the reception element are common elements (the ultrasonic reception surface of the first reception unit is the same surface as the ultrasonic transmission surface of the transmission unit).
  • these elements may be prepared in two. That is, in the ultrasonic sensor 11 illustrated in FIGS. 1A and 1B, the transmission unit and the reception unit (first reception unit) may be configured by separate elements.
  • FIG. 4A is a block diagram showing another configuration example of the ultrasonic detection apparatus of FIG. 1A
  • FIG. 4B is a diagram showing a circuit configuration example thereof.
  • FIG. 5A and FIG. 5B are diagrams for explaining a processing example during normal operation and abnormal operation in the ultrasonic detection apparatus of FIG. 4B.
  • the configuration example illustrated in FIGS. 4A and 4B will be described in comparison with the configuration example in FIGS. 2A and 2B.
  • the ultrasonic detection device 4 of this configuration example includes a transmission unit 41a and a reception unit 41b instead of the transmission / reception unit 11a, and corresponds to a portion excluding the amplifier 44a corresponding to the amplifier 14e and the amplifier 14e of the amplifier / comparator 14.
  • an MPU 40 corresponding to the MPU 10.
  • Reference numerals 44ba, 44bb, 44bc, and 44bd in the amplifier / comparator 44b have the same configurations as the reference numerals 14a, 14b, 14c, and 14d in FIG. 2B, respectively.
  • the reception unit 41b receives the signal Rx1 and the ultrasonic signal Tx of the ultrasonic signal Tx transmitted by the transmission unit 41a.
  • the signal Rx2 is also received as a reflected wave.
  • the output of the amplifier 44ba is Aout1 and Aout2
  • the input of the comparator 44bc is Cin1 and Cin2
  • the output of the comparator 44bc is Cout1 and Cout2.
  • the diagnostic sensor 13 is also the same as the configuration example of FIGS. 2A and 2B in this configuration example, and the signal example is also the same as that of FIGS. 3A and 3B as shown in FIGS. 5A and 5B.
  • the transmitting / receiving elements when the transmitting / receiving elements are employed, the number of elements can be reduced, so that the cost can be reduced.
  • the elements It has the disadvantage of misdetecting its own vibration as a reflected wave.
  • the use of the transmission / reception element has a demerit that it is not suitable for measuring a short distance and extends the dead zone.
  • the elements are divided into two as in the configuration examples of FIGS. 4A and 4B, the cost increases, but such disadvantages can be eliminated.
  • FIG. 6A is a schematic diagram illustrating a configuration example of an ultrasonic detection apparatus according to the second embodiment of the present invention
  • FIG. 6B is a diagram illustrating a state in which deposits adhere to the transmission surface.
  • the ultrasonic detection device 6 includes the horn 12 described above, and circulates on the inner peripheral surface or the outer peripheral surface of the horn 12 (the outer peripheral surface in the example of FIG. 6A).
  • a vibration transmission body 60 is provided for transmitting ultrasonic vibration from the transmission surface to the reception surface of the diagnostic sensor 13.
  • the material of the vibration transmitting body 60 is not limited as long as vibration can be transmitted to the receiving surface such as a piezoelectric element.
  • the horn 12 may be thinly formed at the position of the vibration transmitting body 60.
  • the vibration transmitting body 60 is provided on the inner peripheral surface, it is an obstacle to improving the sound collecting property and directivity of ultrasonic waves. It is preferable to form it so as to be embedded in the surface of the horn 12 so as not to occur. It can also be embedded inside the horn 12.
  • 6A shows an example in which the vibration transmitting body 60 is provided in a strip shape so as to be horizontal to the ultrasonic transmission surface of the ultrasonic sensor 11, but the present invention is not limited to this.
  • the reception level may be lower than in the configuration in which the vibration transmitting body 60 is not provided. Therefore, in this embodiment, the amplitude of the received waveform in a state where there is no adhering matter is recorded in advance, this is set as the initial state amplitude, and the initial state amplitude is compared with the current amplitude at the time of diagnosis after installation. If it is smaller, it is preferable to determine that there is a deposit.
  • FIG. 7 is a schematic cross-sectional view showing a configuration example of an ultrasonic detection apparatus according to the third embodiment of the present invention.
  • first embodiment Only differences from the first embodiment will be mainly described, but the others are the same.
  • the ultrasonic detection device 7 includes the horn 12 described above, and has a recess 71 in a part of the inner peripheral surface of the horn 12.
  • the side wall 70 is a side wall generated by the depression 71.
  • the diagnostic sensor 13 is attached so that the receiving surface of the diagnostic sensor 13 is located in the recess 71 and faces the inner peripheral surface. For example, when the ultrasonic sensor 11 is installed upward, the depression 71 is installed in a direction perpendicular to the sensor oscillation direction as illustrated.
  • the receiving surface of the diagnostic sensor 13 in the depression 71 not only does it not interfere with ultrasonic transmission, but also deposits are difficult to accumulate on the receiving surface, so that the reliability of diagnosis is increased.
  • FIG. 8 is a diagram for explaining a processing example in the ultrasonic detection apparatus according to the fourth embodiment of the present invention.
  • the first embodiment will be mainly described, but the others are the same, and the combined use with the second and third embodiments is also possible.
  • the diagnostic sensor 13 Since the diagnostic sensor 13 is arranged in the vicinity of the ultrasonic transmission surface, it can receive the ultrasonic wave from there as it is, and the amplitude of the received signal is larger than the received signal by the reflected wave. Therefore, in the present embodiment, the threshold Thb for detecting the ultrasonic wave transmitted from the transmission unit of the ultrasonic sensor 11 in the second reception unit of the diagnostic sensor 13 is set to the transmission unit in the first reception unit of the ultrasonic sensor 11. Is higher than the threshold value Tha for detecting the ultrasonic wave transmitted from.
  • Tha and Thb are determined based on the signal level when there is no deposit.
  • the threshold value Tha is a value that can detect a reflected wave during normal operation.
  • This embodiment is particularly effective when a transmission / reception element is used as shown in FIG. 2A, and FIG. 8 shows an example of a signal during abnormal operation corresponding to FIG. 3B.
  • this embodiment can also be applied to the case where separate elements are used as shown in FIG. 4A.
  • the output signal Cout of the comparator 14 c of the ultrasonic sensor 11 is Low during an abnormal operation due to an attached substance or the like. However, if only the output signal Cout becomes Low, there may be no object or obstacle to be measured during normal operation.
  • the output signal Cdout2 by the latter of the signal Rxd1 directly received and the signal Rxd2 received the reflected wave is Although it is Low, the former output signal Cdout1 of the comparator 15c is a High signal.
  • the output signal Cdout1 also becomes Low. That is, in this embodiment, even when the output signal Cout is Low, the presence / absence of an adhering substance can be explicitly detected based on whether the output signal Cdout1 is Low / High.
  • Cout is Low when no object is present
  • Cdout1 and Cdout2 are Low when an abnormal operation is caused by an adhering substance or the like
  • Cdout1 is High and Cdout2 is Low when the operation is normal.
  • the output signal Cdout1 is output regardless of whether the output signal Cout is High or Low. Since it is possible to explicitly detect the presence / absence of the deposit depending on which of Low / High, it is easy to detect when the deposit is present.
  • the threshold values since the threshold values are compared, it is basically assumed that the second receiving unit has the same structure as the first receiving unit. If they do not have the same structure, the threshold value may be determined in consideration of the difference in structure, and when combined with the third embodiment, the vibration loss in the vibration transmitting body 60 is also taken into consideration. What is necessary is just to determine a threshold value.
  • FIG. 9 is a diagram for explaining a processing example in the ultrasonic detection apparatus according to the fifth embodiment of the present invention, and is a diagram illustrating a signal example during an abnormal operation corresponding to FIG. 3B.
  • the fourth embodiment Only differences from the fourth embodiment will be mainly described, but the others are the same and can be used in combination with the second and third embodiments.
  • the threshold Thb1 for detecting the ultrasonic wave transmitted from the transmitting unit of the ultrasonic sensor 11 in the second receiving unit of the diagnostic sensor 13 is set to the above-described threshold value.
  • the threshold value Thb2 is provided in addition to the threshold value Thb1.
  • the threshold value Thb2 is basically the same value as the threshold value Tha. Both threshold values are determined based on the signal level when no deposit is present.
  • the threshold value Tha is a value that can be detected by a reflected wave in a normal state.
  • the output signal Cout of the comparator 14 c of the ultrasonic sensor 11 becomes Low as in the case of FIG. 8.
  • the output signal Cdout2 by the signal Rxd2 that has received the reflected wave becomes Low by the same threshold Thb2 as the threshold Tha, but the comparator 15c by the signal Rxd1 directly received by the threshold Thb1 that is higher than the threshold Tha.
  • Output signal Cdout1 becomes High.
  • the output signal Cdout1 is also Low. That is, in this embodiment, even when the output signal Cout is Low, the presence / absence of an adhering substance can be explicitly detected based on whether the output signal Cdout1 is Low / High.
  • Cout is Low when no object is present
  • Cdout1 and Cdout2 are Low when an abnormal operation is caused by an adhering substance or the like
  • Cdout1 is High and Cdout2 is Low when the operation is normal.
  • the threshold values are compared, it is basically assumed that the second receiving unit has the same structure as the first receiving unit. However, for example, the threshold value Thb2 may not be exactly the same as the threshold value Tha. If they do not have the same structure, the threshold value may be determined in consideration of the difference in structure, and when combined with the third embodiment, the vibration loss in the vibration transmitting body 60 is also taken into consideration. What is necessary is just to determine a threshold value.
  • the output signals Cdout1 and Cdout2 may be High when the output signal Cout is Low.
  • the diagnostic sensor 13 can detect that there is no deposit from the reflected wave, and double check with detection from direct ultrasonic waves is possible.
  • FIG. 10A is a block diagram illustrating a configuration example of the ultrasonic detection apparatus according to the present embodiment, is also a block diagram illustrating another configuration example of the ultrasonic detection apparatus of FIG. 1A, and FIG. 10B is a circuit configuration example thereof.
  • FIG. FIG. 11A and FIG. 11B are diagrams for explaining processing examples during normal operation and abnormal operation in the ultrasonic detection apparatus of FIG. 10B, respectively.
  • first and fifth embodiments will be mainly described, but the other points are the same.
  • the ultrasonic detection apparatus 100 illustrated in FIGS. 10A and 10B will be described in comparison with the configuration example of the ultrasonic detection apparatus 4 in FIGS. 4A and 4B.
  • the ultrasonic detection apparatus 100 includes an MPU 110, a transmission unit 111a, and an amplifier 114a corresponding to the MPU 40, the transmission unit 41a, and the amplifier 44a, and a reception unit 111b that also serves as the reception unit 41b and the reception unit 13a, and an amplifier / comparator. 44b and 15 has an amplifier / comparator 114b.
  • Reference numerals 114ba, 114bb and 114bc in the amplifier / comparator 114b have the same configurations as the reference numerals 44ba (15a), 44bb (15b) and 44bc (15c) in FIG. 4B, respectively.
  • the amplifier / comparator 114b has two comparator reference threshold storage units 114bd and 114be for the threshold Th1 and the threshold Th2.
  • the threshold value Th2 corresponds to the above-described threshold value Tha and threshold value Thb2
  • the threshold value Th1 corresponds to the above-described threshold value Thb1. Both threshold values are determined based on the signal level when no deposit is present.
  • the reception unit 111 b outputs the signal Rx 1 to the ultrasonic signal Tx transmitted by the transmission unit 111 a.
  • the signal Rx2 is also received as a reflected wave of the ultrasonic signal Tx.
  • the output of the amplifier 114ba is Aout1 and Aout2
  • the input of the comparator 114bc is Cdin and Cin
  • the output of the comparator 114bc is Cdout and Cout.
  • Cout which is a reflected wave signal when the reflected wave is detected at the threshold Th2
  • Cdout which is a self-diagnosis signal when the ultrasonic signal Tx emitted from the ultrasonic transmission surface is directly received and detected with the threshold Th1, is also High.
  • Cout is Low when no object is present
  • Cdout is Low when an abnormal operation is caused by a deposit or the like
  • Cdout is High when the object is operating normally.
  • the ultrasonic detection apparatus 100 needs to receive the ultrasonic signal Tx directly as the signal Rx1, does not have a separate diagnostic sensor, and has a threshold Th1 for the signal Rx1. Therefore, in this embodiment, the transmission part 111a and the receiving part 111b are comprised by the separate element.
  • the ultrasonic transmission surface of the transmission unit 111a and the ultrasonic reception surface of the reception unit 111b are close to each other, but they may be separated. Therefore, the ultrasonic sensor 11 and the diagnostic sensor 13 in FIG. Also in this embodiment, application examples such as installation in a vibration transmitting body or a depression as in the second and third embodiments can be applied.

Abstract

Provided is an ultrasonic detection device that, if detection results of a reflection-type ultrasonic sensor are results detected in a state with no adhered matter on an ultrasound transmission surface, is capable of guaranteeing that this is the case. An ultrasonic detection device (1) according to the present invention is provided with a reflection-type ultrasonic sensor (11) having a transmission unit for transmitting ultrasound and a first reception unit for receiving the ultrasound and an ultrasonic sensor for diagnosis (13) near the ultrasound transmission surface of the transmission unit. The ultrasonic sensor for diagnosis (13) has a second reception unit for receiving ultrasound transmitted from the ultrasound transmission surface and detects the presence of adhered matter D adhered to the ultrasound transmission surface on the basis of the reception results of the second reception unit.

Description

超音波検知装置Ultrasonic detector
　本発明は、超音波センサを備えた超音波検知装置に関する。 The present invention relates to an ultrasonic detector provided with an ultrasonic sensor.
　従来から、距離測定や障害物検知などのために超音波センサが利用されている。しかし、超音波センサは、超音波の送信面や受信面（兼用の場合もある）に埃やゴミなどの付着物が溜まると、距離測定や障害物検知が不能になる。特に、屋外用の超音波センサは、送信面や受信面に泥や雪などの吸音体が付着する場合もある。 Conventionally, ultrasonic sensors have been used for distance measurement and obstacle detection. However, the ultrasonic sensor cannot measure distances or detect obstacles if deposits such as dust and dirt accumulate on the ultrasonic transmission surface and reception surface (which may be used in some cases). In particular, an outdoor ultrasonic sensor may have a sound absorber such as mud or snow attached to a transmission surface or a reception surface.
　また、超音波センサの診断を行う技術も様々提案されている。特許文献１には、超音波センサを備えた移動ロボットにおいて、超音波センサの送信部から送信された超音波の残響を受信部で受信し、その残響のレベルが設定値以下の場合に、送信部又は受信部が異常であると判定する技術が開示されている。この技術により、移動ロボット本体を使用しない間に超音波センサにゴミが溜まり、それによって超音波センサの送信部又は受信部が誤動作していることを判定できる。 Also, various techniques for diagnosing ultrasonic sensors have been proposed. In patent document 1, in a mobile robot equipped with an ultrasonic sensor, the reverberation of an ultrasonic wave transmitted from the transmission unit of the ultrasonic sensor is received by the receiving unit, and the transmission is performed when the level of the reverberation is equal to or lower than a set value. A technique for determining that a part or a receiving part is abnormal is disclosed. With this technique, it is possible to determine that dust accumulates in the ultrasonic sensor while the mobile robot body is not used, thereby causing the transmitter or receiver of the ultrasonic sensor to malfunction.
　特許文献２には、車両用障害物検知装置において、周囲環境温度が低くないと判定された場合に、残響振動の継続時間が超音波振動子の故障状態を表すか否かを判定し、周囲環境温度が低いと判定された場合に、残響振動の継続時間が振動面の凍結状態を表すか否かを判定する技術が開示されている。 In Patent Document 2, in the vehicle obstacle detection device, when it is determined that the ambient environment temperature is not low, it is determined whether or not the duration of the reverberation vibration represents a failure state of the ultrasonic transducer, A technique for determining whether or not the duration of reverberation vibration represents a frozen state of a vibration surface when it is determined that the environmental temperature is low is disclosed.
　特許文献３には、障害物センサとしての超音波センサを移動体の複数個所に設け、これら障害物センサの信号の送受信により移動体の周辺に存在する障害物を検知するシステムが開示されている。このシステムでは、各障害物センサを複数組に分けて組毎に異なるタイミングで動作させると共に、各障害物センサのそれぞれについて、送信部から送信され、受信部に直接廻り込む超音波信号の検出有無を判断し、検出有の障害物センサを正常として認識し、検出無しの障害物センサを異常として認識するようにしている。 Patent Document 3 discloses a system in which ultrasonic sensors as obstacle sensors are provided at a plurality of locations on a moving body, and obstacles existing around the moving body are detected by transmitting and receiving signals from these obstacle sensors. . In this system, each obstacle sensor is divided into a plurality of groups and operated at different timings for each group, and for each obstacle sensor, an ultrasonic signal transmitted from the transmission unit and directly around the reception unit is detected. The obstacle sensor with detection is recognized as normal, and the obstacle sensor without detection is recognized as abnormal.
　特許文献４には、プローブから被検体に超音波を送り、プローブが戻りのエコー信号を受信して被検体を診断する超音波診断装置において、プローブ等のハードウェア要素の休止中に送受信テストによる自己診断を行い、ハードウェア要素の故障や異常を検出する技術が開示されている。 Patent Document 4 discloses an ultrasonic diagnostic apparatus that sends an ultrasonic wave from a probe to a subject and receives a return echo signal to diagnose the subject. A technique for performing a self-diagnosis and detecting a failure or abnormality of a hardware element is disclosed.
特開平７－３２７８９５号公報JP-A-7-327895 特開２００２－７１８０５号公報JP 2002-71805 A 特開２０１０－２１０４１２号公報JP 2010-210412 A 特開２０１０－１９３９５８号公報JP 2010-193958 A
　上述のように、超音波センサは、超音波の送信面や受信面に付着物があると距離測定や障害物検知が不可能になる。そのため、超音波センサは、衝突検知用途などの安全確認用のセンサとして使用する場合には、その検知結果の信頼性が欠如してしまうことになる。 As described above, the ultrasonic sensor cannot measure distances or detect obstacles if there are any deposits on the ultrasonic transmission surface or reception surface. Therefore, when the ultrasonic sensor is used as a safety confirmation sensor such as a collision detection application, the detection result is unreliable.
　より具体的に説明すると、超音波センサでは、超音波を発振してから返ってくるまでの時間と音速から距離を求めることができる。そして、障害物検知用の超音波センサでは、超音波が返ってきた場合にはその超音波センサで検知できる範囲内に障害物が存在し、超音波が返ってこなかった場合にはその範囲内に障害物が存在しないと判定する。 More specifically, in the ultrasonic sensor, the distance can be obtained from the time from oscillating the ultrasonic wave until returning, and the speed of sound. In the ultrasonic sensor for obstacle detection, when the ultrasonic wave is returned, the obstacle exists within the range that can be detected by the ultrasonic sensor, and when the ultrasonic wave does not return, the range is within that range. It is determined that there are no obstacles.
　従って、このような超音波センサでは、送信面上の付着物（堆積物）により結果的に超音波が発振されなかった場合や返ってきた超音波が付着物に吸収されてしまった場合にも、超音波が返ってきていないことが分かるだけであるため、障害物無しと判定することになる。このような判定は、特に送信面や受信面に泥や雪などの吸音体が付着している場合に生じ得る。そして、このような判定を行ってしまい、その判定結果を元に例えば移動ロボットなどが移動をしてしまうと、障害物との衝突の危険が生じることになる。 Therefore, in such an ultrasonic sensor, even when the ultrasonic wave is not oscillated as a result of the deposit (deposit) on the transmission surface, or when the returned ultrasonic wave is absorbed by the deposit. Since it is only understood that the ultrasonic wave has not returned, it is determined that there is no obstacle. Such a determination may occur particularly when a sound absorber such as mud or snow is attached to the transmission surface or the reception surface. If such a determination is made and the mobile robot or the like moves based on the determination result, for example, there is a risk of collision with an obstacle.
　しかしながら、特許文献１～４に記載の超音波センサでは、異常（故障）の検知をその超音波センサの受信部が行っているため、検知結果の信頼性を向上させることができるとは言えない。特に、例えば移動ロボットや自動車などの移動体に設けた超音波センサは、走行前に付着していなかった吸音体が走行中に付着してしまった場合を考慮すると、その検知結果が信頼できるものとは言えず、安全確認用のセンサとして信頼性に欠けることになる。 However, in the ultrasonic sensors described in Patent Documents 1 to 4, it cannot be said that the reliability of the detection result can be improved because the reception unit of the ultrasonic sensor detects abnormality (failure). . In particular, for example, an ultrasonic sensor provided on a moving body such as a mobile robot or an automobile has a reliable detection result in consideration of a case where a sound absorbing body that has not adhered before traveling has adhered during traveling. However, it is not reliable as a safety confirmation sensor.
　本発明は、上述のような実状に鑑みてなされたものであり、その目的は、反射型の超音波センサでの検知結果が、超音波送信面に付着物が存在しない状態で検知された結果である場合に、そのことを保証することが可能な超音波検知装置を提供することにある。 The present invention has been made in view of the above-described actual situation, and the purpose thereof is a result of detecting a detection result by a reflection type ultrasonic sensor in a state in which no deposit is present on the ultrasonic transmission surface. In such a case, it is an object of the present invention to provide an ultrasonic detection device capable of guaranteeing that.
　上記の課題を解決するために、本発明の第１の技術手段は、超音波を送信する送信部及び該超音波を受信する第１受信部を有する反射型の超音波センサを備えた超音波検知装置であって、前記送信部における超音波送信面の近傍に診断用超音波センサを、さらに備え、前記診断用超音波センサは、前記超音波送信面から送信された超音波を受信する第２受信部を有し、該第２受信部での受信結果に基づき前記超音波送信面に付着した付着物の有無を検知することを特徴としたものである。 In order to solve the above-described problem, a first technical means of the present invention is an ultrasonic wave including a reflection type ultrasonic sensor having a transmission unit that transmits ultrasonic waves and a first reception unit that receives the ultrasonic waves. A detection device, further comprising a diagnostic ultrasonic sensor in the vicinity of the ultrasonic transmission surface in the transmission unit, wherein the diagnostic ultrasonic sensor receives an ultrasonic wave transmitted from the ultrasonic transmission surface. 2 receivers are provided, and the presence or absence of an adhering substance adhering to the ultrasonic transmission surface is detected based on the reception result at the second receiver.
　本発明の第２の技術手段は、第１の技術手段において、前記診断用超音波センサは、前記超音波送信面から送信された超音波を受信する受信面が前記超音波送信面に対してほぼ垂直になるように配設されていることを特徴としたものである。 According to a second technical means of the present invention, in the first technical means, the diagnostic ultrasonic sensor has a receiving surface for receiving ultrasonic waves transmitted from the ultrasonic transmission surface with respect to the ultrasonic transmission surface. It is characterized by being arranged so as to be substantially vertical.
　本発明の第３の技術手段は、第１又は第２の技術手段において、前記第１受信部の超音波受信面は、前記超音波送信面と共通の面であることを特徴としたものである。 According to a third technical means of the present invention, in the first or second technical means, the ultrasonic receiving surface of the first receiving unit is a surface common to the ultrasonic transmitting surface. is there.
　本発明の第４の技術手段は、第１～第３のいずれか１の技術手段において、前記超音波センサに取り付けられたホーンをさらに備え、前記診断用超音波センサの受信面は、前記ホーンに取り付けられていることを特徴としたものである。 According to a fourth technical means of the present invention, in any one of the first to third technical means, the sonic sensor further includes a horn attached to the ultrasonic sensor, and the receiving surface of the diagnostic ultrasonic sensor includes the horn. It is characterized by being attached to.
　本発明の第５の技術手段は、第１～第３のいずれか１の技術手段において、前記超音波センサに取り付けられたホーンと、該ホーンの内周面又は外周面を周回し、前記超音波送信面からの超音波の振動を前記診断用超音波センサの受信面に伝達させる振動伝達体と、をさらに備えたことを特徴としたものである。 According to a fifth technical means of the present invention, in any one of the first to third technical means, a horn attached to the ultrasonic sensor and an inner peripheral surface or an outer peripheral surface of the horn are circulated, And a vibration transmitting body for transmitting ultrasonic vibration from the sound wave transmitting surface to the receiving surface of the diagnostic ultrasonic sensor.
　本発明の第６の技術手段は、第１～第３のいずれか１の技術手段において、前記超音波センサに取り付けられたホーンをさらに備え、該ホーンは内周面の一部に窪みを有し、前記診断用超音波センサは、前記診断用超音波センサの受信面が前記窪みに位置し前記内周面側を向くように取り付けられていることを特徴としたものである。 According to a sixth technical means of the present invention, in any one of the first to third technical means, the horn further includes a horn attached to the ultrasonic sensor, and the horn has a recess in a part of an inner peripheral surface thereof. The diagnostic ultrasonic sensor is attached so that a receiving surface of the diagnostic ultrasonic sensor is located in the recess and faces the inner peripheral surface.
　本発明に係る超音波検知装置によれば、反射型の超音波センサでの検知結果が、超音波送信面に付着物が存在しない状態で検知された結果である場合に、そのことを保証することができる。 According to the ultrasonic detection device of the present invention, when the detection result of the reflection type ultrasonic sensor is a result of detection in a state where there is no deposit on the ultrasonic transmission surface, this is guaranteed. be able to.
本発明の第１の実施形態に係る超音波検知装置の一構成例を示す概略図である。It is the schematic which shows the example of 1 structure of the ultrasonic detection apparatus which concerns on the 1st Embodiment of this invention. 図１Ａの超音波検知装置の送信面に付着物が付着した様子を示す図である。It is a figure which shows a mode that the deposit | attachment adhered to the transmission surface of the ultrasonic detection apparatus of FIG. 1A. 図１Ａの超音波検知装置の一構成例を示すブロック図である。1B is a block diagram showing an example of the configuration of the ultrasonic detection apparatus in FIG. 1A. FIG. 図２Ａの超音波検知装置の回路構成例を示す図である。It is a figure which shows the circuit structural example of the ultrasonic detection apparatus of FIG. 2A. 図２Ｂの超音波検知装置における正常動作時の処理例を説明するための図である。It is a figure for demonstrating the example of a process at the time of normal operation | movement in the ultrasonic detection apparatus of FIG. 2B. 図２Ｂの超音波検知装置における異常動作時の処理例を説明するための図である。It is a figure for demonstrating the process example at the time of abnormal operation | movement in the ultrasonic detection apparatus of FIG. 2B. 図１Ａの超音波検知装置の他の構成例を示すブロック図である。It is a block diagram which shows the other structural example of the ultrasonic detection apparatus of FIG. 1A. 図４Ａの超音波検知装置の回路構成例を示す図である。It is a figure which shows the circuit structural example of the ultrasonic detection apparatus of FIG. 4A. 図４Ｂの超音波検知装置における正常動作時の処理例を説明するための図である。It is a figure for demonstrating the example of a process at the time of normal operation | movement in the ultrasonic detection apparatus of FIG. 4B. 図４Ｂの超音波検知装置における異常動作時の処理例を説明するための図である。It is a figure for demonstrating the process example at the time of abnormal operation | movement in the ultrasonic detection apparatus of FIG. 4B. 本発明の第２の実施形態に係る超音波検知装置の一構成例を示す概略図である。It is the schematic which shows one structural example of the ultrasonic detection apparatus which concerns on the 2nd Embodiment of this invention. 図６Ａの超音波検知装置の送信面に付着物が付着した様子を示す図である。It is a figure which shows a mode that the deposit | attachment adhered to the transmission surface of the ultrasonic detection apparatus of FIG. 6A. 本発明の第３の実施形態に係る超音波検知装置の一構成例を示す概略断面図である。It is a schematic sectional drawing which shows one structural example of the ultrasonic detection apparatus which concerns on the 3rd Embodiment of this invention. 本発明の第４の実施形態に係る超音波検知装置における処理例を説明するための図である。It is a figure for demonstrating the example of a process in the ultrasonic detection apparatus which concerns on the 4th Embodiment of this invention. 本発明の第５の実施形態に係る超音波検知装置における処理例を説明するための図である。It is a figure for demonstrating the example of a process in the ultrasonic detection apparatus which concerns on the 5th Embodiment of this invention. 本発明に関連する第６の実施形態に係る超音波検知装置の一構成例を示すブロック図である。It is a block diagram which shows the example of 1 structure of the ultrasonic detector which concerns on 6th Embodiment relevant to this invention. 図１０Ａの超音波検知装置の回路構成例を示す図である。It is a figure which shows the circuit structural example of the ultrasonic detection apparatus of FIG. 10A. 図１０Ｂの超音波検知装置における正常動作時の処理例を説明するための図である。It is a figure for demonstrating the example of a process at the time of normal operation | movement in the ultrasonic detection apparatus of FIG. 10B. 図１０Ｂの超音波検知装置における異常動作時の処理例を説明するための図である。It is a figure for demonstrating the example of a process at the time of abnormal operation | movement in the ultrasonic detection apparatus of FIG. 10B.
　本発明に係る超音波検知装置は、距離測定や障害物検知などに使用する反射型の超音波センサにおける超音波送信面の近傍に、別途、診断用超音波センサを設けたものである。以下、本発明の様々な実施形態について、図面を参照しながら説明する。 The ultrasonic detection apparatus according to the present invention has a diagnostic ultrasonic sensor separately provided in the vicinity of an ultrasonic transmission surface in a reflection type ultrasonic sensor used for distance measurement, obstacle detection, and the like. Hereinafter, various embodiments of the present invention will be described with reference to the drawings.
（第１の実施形態）
　図１Ａは、本発明の第１の実施形態に係る超音波検知装置の一構成例を示す概略図で、図１Ｂは、その送信面（振動面）に付着物が付着した様子を示す図である。 (First embodiment)
FIG. 1A is a schematic diagram illustrating a configuration example of the ultrasonic detection apparatus according to the first embodiment of the present invention, and FIG. is there.
　図１Ａで例示するように、本実施形態に係る超音波検知装置１は超音波センサ１１を備える。なお、図１Ａでは超音波が発信された様子を模式的に示している。この超音波センサ１１は、超音波を送信する送信部と、その超音波（反射波も含む）を受信する受信部（以下、第１受信部と呼ぶ）とを有する反射型の超音波センサである。 As illustrated in FIG. 1A, the ultrasonic detection device 1 according to this embodiment includes an ultrasonic sensor 11. FIG. 1A schematically shows a state in which ultrasonic waves are transmitted. The ultrasonic sensor 11 is a reflection type ultrasonic sensor having a transmission unit that transmits ultrasonic waves and a reception unit (hereinafter referred to as a first reception unit) that receives the ultrasonic waves (including reflected waves). is there.
　そして、超音波検知装置１は、その主たる特徴として、上記送信部における超音波送信面（発振素子の表面）の近傍に診断用超音波センサ（以下、単に診断センサと言う）１３を備えている。診断センサ１３は、上記超音波送信面から送信された超音波（反射波も含む）を受信する受信部（以下、第２受信部と呼ぶ）を有する。 The ultrasonic detection apparatus 1 includes a diagnostic ultrasonic sensor (hereinafter simply referred to as a diagnostic sensor) 13 in the vicinity of the ultrasonic transmission surface (surface of the oscillation element) in the transmission unit as a main feature. . The diagnostic sensor 13 includes a receiving unit (hereinafter referred to as a second receiving unit) that receives ultrasonic waves (including reflected waves) transmitted from the ultrasonic transmission surface.
　このように、診断センサ１３は、超音波センサ１１とは別系統のセンサであり、メインとなる超音波センサ１１からの超音波による振動を検知するもの、つまり超音波センサ１１の発振をモニタリングして超音波センサ１１を診断するものである。よって、診断センサ１３は受信専用センサである。 As described above, the diagnostic sensor 13 is a sensor of a different system from the ultrasonic sensor 11, and detects the vibration caused by the ultrasonic wave from the main ultrasonic sensor 11, that is, monitors the oscillation of the ultrasonic sensor 11. Thus, the ultrasonic sensor 11 is diagnosed. Therefore, the diagnostic sensor 13 is a reception-only sensor.
　そして、診断センサ１３は、上記第２受信部での受信結果に基づき、図１Ｂで例示したような上記超音波送信面に付着した付着物（堆積物）Ｄの有無を検知する。 And the diagnostic sensor 13 detects the presence or absence of the deposit | attachment (deposit) D adhering to the said ultrasonic transmission surface as illustrated in FIG. 1B based on the reception result in the said 2nd receiving part.
　超音波センサ１１から超音波を送信し、診断センサ１３でその超音波の振動が検知できれば、正常動作とする。一方で、超音波センサ１１から超音波を送信したにも拘わらず、診断センサ１３でその超音波の振動を検知できなければ、超音波送信面に付着物が溜まっている場合も含め、超音波が正常に発信されなかった（つまり異常動作であった）と見做せばよい。なお、この受信結果や検知処理の具体例については、図３Ａ，図３Ｂを参照しながら後述する。 If an ultrasonic wave is transmitted from the ultrasonic sensor 11 and the ultrasonic vibration can be detected by the diagnostic sensor 13, the normal operation is performed. On the other hand, if the ultrasonic vibration is not detected by the diagnostic sensor 13 even though the ultrasonic wave is transmitted from the ultrasonic sensor 11, the ultrasonic wave including the case where deposits are accumulated on the ultrasonic wave transmission surface is included. Can be regarded as not being transmitted normally (that is, abnormal operation). A specific example of the reception result and detection processing will be described later with reference to FIGS. 3A and 3B.
　そして、超音波検知装置１では、正常動作の場合には、超音波センサ１１の第１受信部での測定値を採用し、異常動作の場合には、この時の測定値を破棄すればよい。破棄する際にはエラー情報等を外部に報知することが好ましい。 And in the ultrasonic detection apparatus 1, the measured value in the 1st receiving part of the ultrasonic sensor 11 is employ | adopted in the case of normal operation, and what is necessary is just to discard the measured value at this time in abnormal operation. . When discarding, it is preferable to notify error information or the like to the outside.
　また、診断センサ１３は、超音波センサ１１による検知の障害とならない位置に設けられている必要がある。図１Ａ，図１Ｂで例示する超音波検知装置１は、超音波センサ１１に取り付けられたホーン１２を備え、診断センサ１３の受信面がホーン１２に取り付けられている。 Further, the diagnostic sensor 13 needs to be provided at a position that does not interfere with detection by the ultrasonic sensor 11. The ultrasonic detection apparatus 1 illustrated in FIGS. 1A and 1B includes a horn 12 attached to the ultrasonic sensor 11, and a receiving surface of the diagnostic sensor 13 is attached to the horn 12.
　ホーン１２は、集音性、指向性を向上させ、検知距離を上げるための部材であり、その形状や材質は集音性や指向性が向上できるものであればよく、例えばアルミ合金、チタン合金、ダイス鋼などの素材が用いられる。また、ホーン１２は、振動エネルギーを効率良く伝達させるために、送信する超音波の半波長を基本単位とするようなサイズに形成しておくことが好ましい。 The horn 12 is a member for improving the sound collecting property and directivity and increasing the detection distance. The shape and material of the horn 12 are not limited as long as the sound collecting property and directivity can be improved. A material such as die steel is used. In addition, the horn 12 is preferably formed in a size such that the half wavelength of the ultrasonic wave to be transmitted is a basic unit in order to efficiently transmit vibration energy.
　また、診断センサ１３は、特にホーン１２の内周面（表面）に設けられていることで感度が良くなるため好ましいと言えるが、ホーン１２の外周面に設けてあっても、或いはホーン１２の内部に埋め込んであってもよい。但し、本実施形態は、ホーン１２を備えない形態、例えば四角柱状の凹部の底に超音波センサ１１を設け、その凹部の側壁部に診断センサ１３を設けることなどが挙げられる。 Moreover, it can be said that the diagnostic sensor 13 is preferably provided on the inner peripheral surface (surface) of the horn 12 because the sensitivity is improved. However, even if the diagnostic sensor 13 is provided on the outer peripheral surface of the horn 12, It may be embedded inside. However, in the present embodiment, the horn 12 is not provided, for example, the ultrasonic sensor 11 is provided on the bottom of a quadrangular prism-shaped recess, and the diagnostic sensor 13 is provided on the side wall of the recess.
　以上、本実施形態に係る超音波検知装置１によれば、超音波センサ１１で送信された超音波を、別途設けた診断センサ１３で診断するため、反射型の超音波センサ１１での検知結果が、超音波送信面に付着物が存在しない状態で検知された結果である場合に、そのことを保証することができる。 As described above, according to the ultrasonic detection apparatus 1 according to the present embodiment, the ultrasonic wave transmitted by the ultrasonic sensor 11 is diagnosed by the diagnostic sensor 13 provided separately, and therefore the detection result by the reflective ultrasonic sensor 11 is detected. However, this can be ensured when the result is detected in a state where no deposit is present on the ultrasonic transmission surface.
　つまり、この超音波検知装置１では、超音波センサ１１とその診断のために設けた診断センサ１３とを並列で動作させているため、超音波センサ１１が正常に動作した結果得られたデータである場合、そのことを保証することができる。無論、付着物が存在した場合には異常動作となるため、診断センサ１３により超音波センサ１１の異常動作を検知することができる。 That is, in this ultrasonic detection apparatus 1, since the ultrasonic sensor 11 and the diagnostic sensor 13 provided for the diagnosis are operated in parallel, data obtained as a result of the normal operation of the ultrasonic sensor 11 is used. If there is, we can guarantee that. Of course, since abnormal operation occurs when there is a deposit, the abnormal operation of the ultrasonic sensor 11 can be detected by the diagnostic sensor 13.
　また、診断センサ１３は、図１Ａ，図１Ｂで例示したように、超音波送信面から送信された超音波を受信する受信面が超音波送信面に対してほぼ垂直になるように配設されていることが好ましい。 In addition, as illustrated in FIGS. 1A and 1B, the diagnostic sensor 13 is disposed such that the reception surface that receives the ultrasonic waves transmitted from the ultrasonic transmission surface is substantially perpendicular to the ultrasonic transmission surface. It is preferable.
　例えば、超音波センサ１１が上向きで設置されていて付着物が溜まった場合には超音波センサ１１からの超音波は診断センサ１３で検出できなくなる。しかし、診断センサ１３は超音波センサ１１の発振方向にほぼ垂直に取り付けられているため、上記付着物が構造的に溜まらない。このため、診断センサ１３に付着物があるのではなく、超音波センサ１１が付着物などにより発振不能となっていることを確実に検知することができる。 For example, when the ultrasonic sensor 11 is installed facing upward and deposits accumulate, ultrasonic waves from the ultrasonic sensor 11 cannot be detected by the diagnostic sensor 13. However, since the diagnostic sensor 13 is attached substantially perpendicularly to the oscillation direction of the ultrasonic sensor 11, the deposits do not accumulate structurally. For this reason, it is possible to reliably detect that the ultrasonic sensor 11 is not able to oscillate due to the adhered matter, rather than the diagnostic sensor 13 having the attached matter.
　このように、診断センサ１３をその受信面が上記超音波送信面に対してほぼ垂直に配設することで、超音波センサ１１に溜まるような埃やゴミや雪や泥などの付着物が溜まり難く、診断センサ１３を診断用として有効に機能させることができる。 In this way, the diagnostic sensor 13 is disposed such that the receiving surface thereof is substantially perpendicular to the ultrasonic transmission surface, and thus deposits such as dust, dirt, snow and mud that accumulate on the ultrasonic sensor 11 accumulate. It is difficult to make the diagnostic sensor 13 function effectively for diagnosis.
　但し、診断センサ１３は、超音波送信面に対して角度を付けるように受信面が設けられているだけでも（超音波の送信の邪魔になる位置には設けない）、超音波送信面に溜まるような付着物が溜まり難いと言える。 However, the diagnostic sensor 13 accumulates on the ultrasonic transmission surface even if the reception surface is provided so as to make an angle with respect to the ultrasonic transmission surface (not provided at a position that interferes with the transmission of ultrasonic waves). It can be said that such deposits are difficult to accumulate.
　次に、図２Ａ～図３Ｂを参照しながら、超音波検知装置１の具体的な構成例について説明する。図２Ａは、図１Ａの超音波検知装置の一構成例を示すブロック図で、図２Ｂは、その回路構成例を示す図である。また、図３Ａ、図３Ｂはそれぞれ、図２Ｂの超音波検知装置における正常動作時、異常動作時の処理例を説明するための図である。 Next, a specific configuration example of the ultrasonic detection apparatus 1 will be described with reference to FIGS. 2A to 3B. 2A is a block diagram illustrating a configuration example of the ultrasonic detection apparatus of FIG. 1A, and FIG. 2B is a diagram illustrating a circuit configuration example thereof. FIGS. 3A and 3B are diagrams for explaining processing examples during normal operation and abnormal operation in the ultrasonic detection apparatus of FIG. 2B, respectively.
　図２Ａで例示する超音波センサは、超音波送信面と超音波受信面とを共通化して構成されたセンサであり、超音波送受信用のセンサ素子（圧電体等）である送受信部１１ａを有する。つまり、このセンサ素子は、発振用素子と受信用素子とを共通化した素子である。 The ultrasonic sensor illustrated in FIG. 2A is a sensor configured by sharing an ultrasonic transmission surface and an ultrasonic reception surface, and includes a transmission / reception unit 11a that is a sensor element (piezoelectric body or the like) for ultrasonic transmission / reception. . That is, this sensor element is an element in which an oscillation element and a reception element are shared.
　送受信部１１ａは、アンプ・コンパレータ１４に接続されており、アンプ・コンパレータ１４には、超音波検知装置１の制御部の例としてＭＰＵ（Micro Processing Unit）１０が接続されている。つまり、図１Ａ等の超音波センサ１１は、図２Ａの例では上記送信部及び上記第１受信部の一例である、送受信部１１ａ及びアンプ・コンパレータ１４を有すると共に、ＭＰＵ１０を有する。 The transmitting / receiving unit 11 a is connected to an amplifier / comparator 14, and an MPU (Micro Processing Unit) 10 is connected to the amplifier / comparator 14 as an example of a control unit of the ultrasonic detection device 1. That is, the ultrasonic sensor 11 of FIG. 1A and the like includes the transmission / reception unit 11a and the amplifier / comparator 14 which are examples of the transmission unit and the first reception unit in the example of FIG.
　図２Ｂで例示するように、アンプ・コンパレータ１４は、送信時に用いるアンプ１４ｅを有する。ＭＰＵ１０は、例えば４０ｋＨｚ（周期２５μｓ）近辺の矩形パルスの信号を生成し、その信号（送信信号）をアンプ１４ｅに出力し、アンプ１４ｅはその送信信号を増幅させて送受信部１１ａに出力する。これにより、送受信部１１ａでは、センサ素子が振動し、図３Ａの信号Ｔｘのような超音波が空気中に出力される。 As illustrated in FIG. 2B, the amplifier / comparator 14 includes an amplifier 14e used for transmission. The MPU 10 generates a rectangular pulse signal in the vicinity of 40 kHz (period 25 μs), for example, and outputs the signal (transmission signal) to the amplifier 14e. The amplifier 14e amplifies the transmission signal and outputs the amplified signal to the transmission / reception unit 11a. Thereby, in the transmission / reception part 11a, a sensor element vibrates and an ultrasonic wave like the signal Tx of FIG. 3A is output in the air.
　また、アンプ・コンパレータ１４は、受信時に用いるアンプ１４ａ、整流回路１４ｂ、コンパレータ１４ｃ、及びコンパレータ基準電圧の格納部１４ｄを有する。なお、格納部１４ｄはメモリであってもよいが、無論、抵抗などだけで構成してもよい。 The amplifier / comparator 14 includes an amplifier 14a, a rectifier circuit 14b, a comparator 14c, and a comparator reference voltage storage unit 14d used at the time of reception. The storage unit 14d may be a memory, but may of course be configured with only a resistor or the like.
　送受信部１１ａは、図３Ａの信号Ｒｘのような超音波の反射波の信号を受信し（センサ素子の振動を感知し）アンプ１４ａに出力する。なお、送信信号Ｔｘの送信時には、受信処理は行わないようになっており、そのため反射波だけを受信することになる。アンプ１４ａは、それを増幅させ、図３Ａの信号Ａｏｕｔのような信号にし、整流回路１４ｂに出力する。整流回路１４ｂは、その信号を直流信号の振幅に変換し、コンパレータ１４ｃに出力する。 The transceiver 11a receives an ultrasonic reflected wave signal such as the signal Rx in FIG. 3A (senses the vibration of the sensor element) and outputs it to the amplifier 14a. Note that when the transmission signal Tx is transmitted, no reception process is performed, and therefore only the reflected wave is received. The amplifier 14a amplifies it, makes it a signal like the signal Aout in FIG. 3A, and outputs it to the rectifier circuit 14b. The rectifier circuit 14b converts the signal into a DC signal amplitude and outputs the signal to the comparator 14c.
　コンパレータ１４ｃは、図３Ａの信号Ｃｉｎのような整流回路１４ｂからの入力信号と格納部１４ｄに格納されたコンパレータ基準電圧Ｔｈとを比較し、このコンパレータ基準電圧Ｔｈ以上の振動であった場合、障害物が検知されたとしてデジタルのＨｉｇｈ信号をＭＰＵ１０に出力する。ＭＰＵ１０には、図３Ａに示すようなパルスの信号Ｃｏｕｔが入力される。なお、Ｔｈは付着物が存在しないときの信号レベルに基づき決めておく。 The comparator 14c compares the input signal from the rectifier circuit 14b such as the signal Cin in FIG. 3A with the comparator reference voltage Th stored in the storage unit 14d. A digital high signal is output to the MPU 10 as an object is detected. The MPU 10 receives a pulse signal Cout as shown in FIG. 3A. Th is determined based on the signal level when there is no deposit.
　また、ＭＰＵ１０は、超音波を送信してから反射波が返ってくるまでの時間を計測し、対象物までの距離を算出することができる。対象までの距離は、「音速」×「発振から受信までにかかった時間」で求められる。超音波センサ１１が単に障害物検知用ではなく、距離測定用の場合には、ＭＰＵ１０でこのような処理を追加しておけばよい。 Also, the MPU 10 can measure the time from when the ultrasonic wave is transmitted until the reflected wave returns, and calculate the distance to the object. The distance to the object is obtained by “sound speed” × “time taken from oscillation to reception”. When the ultrasonic sensor 11 is not just for detecting an obstacle but for measuring a distance, the MPU 10 may add such processing.
　一方で、コンパレータ１４ｃは、比較によりＴｈ未満の振動であった場合、障害物等の物体が検知されなかったとしてデジタルのＬｏｗ信号をＭＰＵ１０に出力する。 On the other hand, if the comparison shows that the vibration is less than Th, the comparator 14c outputs a digital low signal to the MPU 10 assuming that an object such as an obstacle has not been detected.
　また、図１Ａ等で示した診断センサ１３は、図２Ａの例では受信部１３ａ及びアンプ・コンパレータ１５を有する（これらが第２受信部の例に相当）と共に、ＭＰＵ１０を有する。受信部１３ａは超音波受信用のセンサ素子である。アンプ・コンパレータ１５は、アンプ・コンパレータ１４と同様の構成、つまりアンプ１５ａ、整流回路１５ｂ、コンパレータ１５ｃ、及びコンパレータ基準電圧の格納部１５ｄを有する。ＭＰＵ１０はコンパレータ１４ｃからの入力とコンパレータ１５ｃからの入力との双方に対して処理を行う。 Further, the diagnostic sensor 13 shown in FIG. 1A and the like includes the receiving unit 13a and the amplifier / comparator 15 in the example of FIG. 2A (which correspond to the example of the second receiving unit) and the MPU 10. The receiving unit 13a is a sensor element for receiving ultrasonic waves. The amplifier / comparator 15 has the same configuration as the amplifier / comparator 14, that is, an amplifier 15a, a rectifier circuit 15b, a comparator 15c, and a comparator reference voltage storage unit 15d. The MPU 10 processes both the input from the comparator 14c and the input from the comparator 15c.
　図３Ａ，図３Ｂの例では、超音波信号Ｔｘに対し、受信部１３ａが信号Ｒｘｄ１を受信すると共に、超音波信号Ｔｘの反射波として信号Ｒｘｄ２も受信する。信号Ｒｘｄ１，Ｒｘｄ２のそれぞれに対し、アンプ１５ａの出力はＡｄｏｕｔ１，Ａｄｏｕｔ２、コンパレータ１５ｃの入力はＣｄｉｎ１，Ｃｄｉｎ２、コンパレータ１５ｃの出力（ＭＰＵ１０への入力）はＣｄｏｕｔ１，Ｃｄｏｕｔ２となる。 3A and 3B, for the ultrasonic signal Tx, the receiving unit 13a receives the signal Rxd1 and also receives the signal Rxd2 as a reflected wave of the ultrasonic signal Tx. For each of the signals Rxd1 and Rxd2, the output of the amplifier 15a is Addout1, Addout2, the input of the comparator 15c is Cdin1, Cdin2, and the output of the comparator 15c (input to the MPU 10) is Cdout1, Cdout2.
　図３Ａでは、付着物がなく且つ物体があった場合の例を挙げており、そのため、Ｃｄｏｕｔ，Ｃｄｏｕｔ１，Ｃｄｏｕｔ２のいずれもＨｉｇｈとなっている。つまり、コンパレータ１５ｃは、コンパレータ基準電圧Ｔｈ以上の振動であった場合、送受信部１１ａからの超音波が正常に検知されたとして、デジタルのＨｉｇｈ信号をＭＰＵ１０に出力し、コンパレータ１４ｃも信号ＣｉｎがＴｈ以上であった場合、同じくＨｉｇｈ信号をＭＰＵ１０に出力する。なお、ＭＰＵ１０は、コンパレータ１５ｃからの出力により超音波が検知できたことが分かれば済むため、この出力を用いた距離の算出は不要である。 FIG. 3A shows an example in which there is no deposit and there is an object, and therefore, Cdout, Cdout1, and Cdout2 are all high. That is, when the vibration is equal to or higher than the comparator reference voltage Th, the comparator 15c outputs a digital high signal to the MPU 10 on the assumption that the ultrasonic wave from the transmission / reception unit 11a is normally detected, and the comparator 14c also outputs the signal Cin as Th. In the case above, the High signal is also output to the MPU 10. Note that the MPU 10 only needs to know that the ultrasonic wave can be detected from the output from the comparator 15c, and therefore it is not necessary to calculate the distance using this output.
　一方で、コンパレータ１５ｃは、比較によりＴｈ未満の振動であった場合、超音波が検知されなかったとしてデジタルのＬｏｗの信号をＭＰＵ１０に出力する。 On the other hand, when the vibration is less than Th by comparison, the comparator 15c outputs a digital low signal to the MPU 10 assuming that no ultrasonic wave is detected.
　次に、図３Ｂを参照しながら、超音波センサ１１の超音波送信面（この例では超音波受信面と共通）に付着物があり且つ測定対象の物体があった場合の信号の例を説明する。この場合、送受信部１１ａでは図３Ａと比較して振幅の小さな信号Ｒｘを受信することになり、これにより、アンプ１４ａの出力、コンパレータ１４ｃへの入力も小さくなり、コンパレータ基準電圧Ｔｈを超えず、コンパレータ１４ｃの出力信号ＣｏｕｔはＬｏｗとなる。但し、出力信号ＣｏｕｔがＬｏｗとなるだけでは付着物があるのか、測定対象の物体や障害物がないだけなのかは分からない。 Next, referring to FIG. 3B, an example of a signal when there is an attachment on the ultrasonic transmission surface of the ultrasonic sensor 11 (common to the ultrasonic reception surface in this example) and there is an object to be measured will be described. To do. In this case, the transmission / reception unit 11a receives a signal Rx having a smaller amplitude than that in FIG. 3A. As a result, the output of the amplifier 14a and the input to the comparator 14c are also reduced, and do not exceed the comparator reference voltage Th. The output signal Cout of the comparator 14c becomes Low. However, if the output signal Cout is only Low, it is not known whether there is an adhering object or there is no object or obstacle to be measured.
　しかし、付着物がある場合、診断センサ１３側では、受信部１３ａが図３Ａと比較して振幅の小さな信号Ｒｘｄ１，Ｒｘｄ２を受信することになり、これにより、アンプ１５ａの出力、コンパレータ１５ｃへの入力も小さくなり、コンパレータ基準電圧Ｔｈを超えず、コンパレータ１５ｃの出力信号Ｃｄｏｕｔ１，Ｃｄｏｕｔ２はＬｏｗとなる。一方で、付着物がない場合には、物体が無くて出力信号ＣｏｕｔがＬｏｗとなった場合でも、出力信号Ｃｄｏｕｔ１，Ｃｄｏｕｔは常にＨｉｇｈとなる。 However, when there is an adhering substance, on the diagnostic sensor 13 side, the receiving unit 13a receives signals Rxd1 and Rxd2 having a smaller amplitude than that in FIG. 3A. As a result, the output of the amplifier 15a and the comparator 15c are output. The input also becomes small, does not exceed the comparator reference voltage Th, and the output signals Cdout1 and Cdout2 of the comparator 15c become Low. On the other hand, when there is no adhering matter, the output signals Cdout1 and Cdout are always High even when there is no object and the output signal Cout becomes Low.
　以上のように、ＭＰＵ１０は、超音波センサ１１の超音波送信面に付着物が無い場合（正常動作時）にＨｉｇｈのＣｄｏｕｔ１，Ｃｄｏｕｔ２を得ること、つまり超音波センサ１１から超音波が送信されている間、診断センサ１３でも超音波センサ１１と同じような超音波を観測することができ、そのときの送受信部１１ａでの受信結果が付着物無しで受信したものであることを保証することができる。一方で、超音波発振期間にＣｄｏｕｔ１，Ｃｄｏｕｔ２がＬｏｗであれば、正常に超音波が発振されなかったと判定される。 As described above, the MPU 10 obtains High Cdout 1 and Cdout 2 when there is no deposit on the ultrasonic transmission surface of the ultrasonic sensor 11 (during normal operation), that is, the ultrasonic wave is transmitted from the ultrasonic sensor 11. In the meantime, the diagnostic sensor 13 can observe the same ultrasonic wave as the ultrasonic sensor 11, and it can be assured that the reception result at the transmission / reception unit 11 a at that time is the one received without adhering matter. it can. On the other hand, if Cdout1 and Cdout2 are Low during the ultrasonic oscillation period, it is determined that the ultrasonic waves are not normally oscillated.
　また、図２Ｂでは、第２受信部が第１受信部と同じ構造の例（同じ、センサ素子及びアンプ・コンパレータをもつ例）を挙げた。これにより、第２受信部が、超音波センサ１１からの超音波を第１受信部と同じ状態で超音波を検知することができる。但し、異なる構造を採用してもよい。 In FIG. 2B, an example in which the second receiving unit has the same structure as the first receiving unit (the same example having a sensor element and an amplifier / comparator) is given. Thereby, the 2nd receiving part can detect an ultrasonic wave from the ultrasonic sensor 11 in the same state as the 1st receiving part. However, a different structure may be adopted.
　また、図２Ａ～図３Ｂの例では、発振用素子と受信用素子を共通の素子とした例（第１受信部の超音波受信面は送信部の超音波送信面と共通の面である例）を挙げたが、これらの素子は２個に分けて用意してもよい。つまり、図１Ａ，図１Ｂで例示した超音波センサ１１は、送信部と受信部（第１受信部）とが別々の素子で構成されていてもよい。 In the examples of FIGS. 2A to 3B, an example in which the oscillation element and the reception element are common elements (the ultrasonic reception surface of the first reception unit is the same surface as the ultrasonic transmission surface of the transmission unit). However, these elements may be prepared in two. That is, in the ultrasonic sensor 11 illustrated in FIGS. 1A and 1B, the transmission unit and the reception unit (first reception unit) may be configured by separate elements.
　このような構成例について説明する。図４Ａは図１Ａの超音波検知装置の他の構成例を示すブロック図で、図４Ｂはその回路構成例を示す図である。図５Ａ、図５Ｂはそれぞれ、図４Ｂの超音波検知装置における正常動作時、異常動作時の処理例を説明するための図である。 An example of such a configuration will be described. 4A is a block diagram showing another configuration example of the ultrasonic detection apparatus of FIG. 1A, and FIG. 4B is a diagram showing a circuit configuration example thereof. FIG. 5A and FIG. 5B are diagrams for explaining a processing example during normal operation and abnormal operation in the ultrasonic detection apparatus of FIG. 4B.
　図４Ａ，図４Ｂで例示する構成例について、図２Ａ，図２Ｂの構成例と比較して説明する。本構成例の超音波検知装置４は、送受信部１１ａの代わりに送信部４１ａ及び受信部４１ｂを有すると共に、アンプ１４ｅに相当するアンプ４４ａと、アンプ・コンパレータ１４のアンプ１４ｅを除いた部分に相当するアンプ・コンパレータ４４ｂと、ＭＰＵ１０に対応するＭＰＵ４０と、を有する。なお、アンプ・コンパレータ４４ｂにおける符号４４ｂａ，４４ｂｂ，４４ｂｃ，４４ｂｄはそれぞれ図２Ｂの符号１４ａ，１４ｂ，１４ｃ，１４ｄと同じ構成である。 The configuration example illustrated in FIGS. 4A and 4B will be described in comparison with the configuration example in FIGS. 2A and 2B. The ultrasonic detection device 4 of this configuration example includes a transmission unit 41a and a reception unit 41b instead of the transmission / reception unit 11a, and corresponds to a portion excluding the amplifier 44a corresponding to the amplifier 14e and the amplifier 14e of the amplifier / comparator 14. And an MPU 40 corresponding to the MPU 10. Reference numerals 44ba, 44bb, 44bc, and 44bd in the amplifier / comparator 44b have the same configurations as the reference numerals 14a, 14b, 14c, and 14d in FIG. 2B, respectively.
　本構成例における超音波センサ１１では、図５Ａ，図５Ｂに示すように、送信部４１ａで送信された超音波信号Ｔｘに対し、受信部４１ｂが信号Ｒｘ１を受信すると共に、超音波信号Ｔｘの反射波として信号Ｒｘ２も受信する。信号Ｒｄ１，Ｒｄ２のそれぞれに対し、アンプ４４ｂａの出力はＡｏｕｔ１，Ａｏｕｔ２、コンパレータ４４ｂｃの入力はＣｉｎ１，Ｃｉｎ２、コンパレータ４４ｂｃの出力（ＭＰＵ４０への入力）はＣｏｕｔ１，Ｃｏｕｔ２となる。 In the ultrasonic sensor 11 in this configuration example, as illustrated in FIGS. 5A and 5B, the reception unit 41b receives the signal Rx1 and the ultrasonic signal Tx of the ultrasonic signal Tx transmitted by the transmission unit 41a. The signal Rx2 is also received as a reflected wave. For each of the signals Rd1 and Rd2, the output of the amplifier 44ba is Aout1 and Aout2, the input of the comparator 44bc is Cin1 and Cin2, and the output of the comparator 44bc (input to the MPU 40) is Cout1 and Cout2.
　また、診断センサ１３については本構成例でも図２Ａ，図２Ｂの構成例と同じであり、その信号例も図５Ａ，図５Ｂに示すように図３Ａ，図３Ｂと同じである。 The diagnostic sensor 13 is also the same as the configuration example of FIGS. 2A and 2B in this configuration example, and the signal example is also the same as that of FIGS. 3A and 3B as shown in FIGS. 5A and 5B.
　図２Ａ，図２Ｂの構成例のように、送受信兼用素子を採用すると、素子数が減らせるのでコストダウンできるが、発振してから、反射波検出待ち状態になるまで間隔を空けなければ、素子自体の振動を反射波と誤検知してしまうデメリットを持つ。つまり、送受信兼用素子を採用すると、短い距離を測るのには向かなくなり、不感帯を延長することになるというデメリットを有する。一方で、図４Ａ，図４Ｂの構成例のように、素子を２個に分けると、コストは上がるが、このようなデメリットを無くすことができる。 As shown in the configuration examples of FIGS. 2A and 2B, when the transmitting / receiving elements are employed, the number of elements can be reduced, so that the cost can be reduced. However, if the interval between oscillation and waiting for the reflected wave detection is not provided, the elements It has the disadvantage of misdetecting its own vibration as a reflected wave. In other words, the use of the transmission / reception element has a demerit that it is not suitable for measuring a short distance and extends the dead zone. On the other hand, if the elements are divided into two as in the configuration examples of FIGS. 4A and 4B, the cost increases, but such disadvantages can be eliminated.
（第２の実施形態）
　図６Ａは、本発明の第２の実施形態に係る超音波検知装置の一構成例を示す概略図で、図６Ｂは、その送信面に付着物が付着した様子を示す図である。以下、主に第１の実施形態との相違点のみについて説明するが、その他は同様である。 (Second Embodiment)
FIG. 6A is a schematic diagram illustrating a configuration example of an ultrasonic detection apparatus according to the second embodiment of the present invention, and FIG. 6B is a diagram illustrating a state in which deposits adhere to the transmission surface. Hereinafter, only differences from the first embodiment will be mainly described, but the others are the same.
　図６Ａに示すように本実施形態に係る超音波検知装置６は、上述のホーン１２を備えると共に、ホーン１２の内周面又は外周面（図６Ａの例では外周面）を周回し、超音波送信面からの超音波の振動を診断センサ１３の受信面に伝達させる振動伝達体６０を備える。振動伝達体６０の材質は問わず、圧電体素子等の上記受信面に振動の伝達が可能であればよい。 As shown in FIG. 6A, the ultrasonic detection device 6 according to the present embodiment includes the horn 12 described above, and circulates on the inner peripheral surface or the outer peripheral surface of the horn 12 (the outer peripheral surface in the example of FIG. 6A). A vibration transmission body 60 is provided for transmitting ultrasonic vibration from the transmission surface to the reception surface of the diagnostic sensor 13. The material of the vibration transmitting body 60 is not limited as long as vibration can be transmitted to the receiving surface such as a piezoelectric element.
　振動伝達体６０をホーン１２の外周面に設ける場合、その配設位置においてホーン１２を薄く形成しておけばよく、内周面に設ける場合、超音波の集音性や指向性の向上の邪魔にならないようにホーン１２の表面に埋め込むように形成しておくことが好ましい。また、ホーン１２の内部に埋め込むこともできる。また、図６Ａでは、振動伝達体６０を超音波センサ１１の超音波送信面に水平になるように帯状に設けた例を挙げているが、これに限ったものではない。 When the vibration transmitting body 60 is provided on the outer peripheral surface of the horn 12, the horn 12 may be thinly formed at the position of the vibration transmitting body 60. When the vibration transmitting body 60 is provided on the inner peripheral surface, it is an obstacle to improving the sound collecting property and directivity of ultrasonic waves. It is preferable to form it so as to be embedded in the surface of the horn 12 so as not to occur. It can also be embedded inside the horn 12. 6A shows an example in which the vibration transmitting body 60 is provided in a strip shape so as to be horizontal to the ultrasonic transmission surface of the ultrasonic sensor 11, but the present invention is not limited to this.
　本実施形態によれば、図６Ｂで例示するように、ホーン１２に振動伝達体６０を配置しておくことで、ホーン１２のどの向きに吸音体等の付着物が堆積しても検知できる。 According to this embodiment, as illustrated in FIG. 6B, by arranging the vibration transmitting body 60 on the horn 12, it is possible to detect any deposit on the horn 12 such as a sound absorber.
　また、振動伝達体６０を設けた構成では、設けない構成に比べて受信レベルが下がる可能性がある。よって、本実施形態では、予め付着物が無い状態での受信波形の振幅を記録し、これを初期状態振幅としておき、設置後の診断時に、初期状態振幅と現状の振幅を比較し、現状が小さくなっていれば付着物有りと判定することが好ましい。 Further, in the configuration in which the vibration transmitting body 60 is provided, the reception level may be lower than in the configuration in which the vibration transmitting body 60 is not provided. Therefore, in this embodiment, the amplitude of the received waveform in a state where there is no adhering matter is recorded in advance, this is set as the initial state amplitude, and the initial state amplitude is compared with the current amplitude at the time of diagnosis after installation. If it is smaller, it is preferable to determine that there is a deposit.
（第３の実施形態）
　図７は、本発明の第３の実施形態に係る超音波検知装置の一構成例を示す概略断面図である。以下、主に第１の実施形態との相違点のみについて説明するが、その他は同様である。 (Third embodiment)
FIG. 7 is a schematic cross-sectional view showing a configuration example of an ultrasonic detection apparatus according to the third embodiment of the present invention. Hereinafter, only differences from the first embodiment will be mainly described, but the others are the same.
　図７で例示するように、本実施形態に係る超音波検知装置７は、上述のホーン１２を備え、ホーン１２の内周面の一部に窪み７１を有する。側壁７０は窪み７１により生じた側壁である。そして、診断センサ１３は、診断センサ１３の受信面が窪み７１に位置し内周面側を向くように取り付けられている。例えば超音波センサ１１を上向きに設置する場合は、窪み７１を図示したように、センサ発振方向に対して垂直方向に設置するなどしておく。 As illustrated in FIG. 7, the ultrasonic detection device 7 according to this embodiment includes the horn 12 described above, and has a recess 71 in a part of the inner peripheral surface of the horn 12. The side wall 70 is a side wall generated by the depression 71. The diagnostic sensor 13 is attached so that the receiving surface of the diagnostic sensor 13 is located in the recess 71 and faces the inner peripheral surface. For example, when the ultrasonic sensor 11 is installed upward, the depression 71 is installed in a direction perpendicular to the sensor oscillation direction as illustrated.
　診断センサ１３の受信面を窪み７１に設けることで、超音波送信の邪魔にならないだけでなく、その受信面に付着物が堆積し難くなるため、診断の信頼性が高くなる。 By providing the receiving surface of the diagnostic sensor 13 in the depression 71, not only does it not interfere with ultrasonic transmission, but also deposits are difficult to accumulate on the receiving surface, so that the reliability of diagnosis is increased.
（第４の実施形態）
　図８は、本発明の第４の実施形態に係る超音波検知装置における処理例を説明するための図である。以下、主に第１の実施形態との相違点のみについて説明するが、その他は同様であり、第２，第３の実施形態との併用も可能である。 (Fourth embodiment)
FIG. 8 is a diagram for explaining a processing example in the ultrasonic detection apparatus according to the fourth embodiment of the present invention. Hereinafter, only the differences from the first embodiment will be mainly described, but the others are the same, and the combined use with the second and third embodiments is also possible.
　診断センサ１３は超音波送信面の近傍に配置されるので、そこからの超音波をそのまま受信でき、その受信信号の振幅が反射波による受信信号より大きくなる。そこで、本実施形態では、診断センサ１３の第２受信部において超音波センサ１１の送信部から送信された超音波を検知するための閾値Ｔｈｂを、超音波センサ１１の第１受信部において送信部から送信された超音波を検知するための閾値Ｔｈａより高くしている。 Since the diagnostic sensor 13 is arranged in the vicinity of the ultrasonic transmission surface, it can receive the ultrasonic wave from there as it is, and the amplitude of the received signal is larger than the received signal by the reflected wave. Therefore, in the present embodiment, the threshold Thb for detecting the ultrasonic wave transmitted from the transmission unit of the ultrasonic sensor 11 in the second reception unit of the diagnostic sensor 13 is set to the transmission unit in the first reception unit of the ultrasonic sensor 11. Is higher than the threshold value Tha for detecting the ultrasonic wave transmitted from.
　ここで、Ｔｈａ，Ｔｈｂは付着物が存在しないときの信号レベルに基づき決めておく。閾値Ｔｈａは正常動作時の反射波を検知できるような値となっている。本実施形態は、図２Ａのように送受信兼用素子を用いた場合に特に有効であり、図８では、図３Ｂに対応した異常動作時の信号例を挙げている。但し、超音波送信面からの直接の超音波をその受信タイミングから除外することはできるため、本実施形態は、図４Ａのように別々の素子を用いた場合にも適用することはできる。 Here, Tha and Thb are determined based on the signal level when there is no deposit. The threshold value Tha is a value that can detect a reflected wave during normal operation. This embodiment is particularly effective when a transmission / reception element is used as shown in FIG. 2A, and FIG. 8 shows an example of a signal during abnormal operation corresponding to FIG. 3B. However, since direct ultrasonic waves from the ultrasonic transmission surface can be excluded from the reception timing, this embodiment can also be applied to the case where separate elements are used as shown in FIG. 4A.
　図８で例示するように、付着物等による異常動作時には、超音波センサ１１のコンパレータ１４ｃの出力信号ＣｏｕｔはＬｏｗとなる。但し、出力信号ＣｏｕｔがＬｏｗとなるだけでは正常動作時において測定対象の物体や障害物がない可能性もある。 As illustrated in FIG. 8, the output signal Cout of the comparator 14 c of the ultrasonic sensor 11 is Low during an abnormal operation due to an attached substance or the like. However, if only the output signal Cout becomes Low, there may be no object or obstacle to be measured during normal operation.
　しかし、付着物等がない場合、診断センサ１３側では、閾値Ｔｈｂを閾値Ｔｈａより高く設定してあるため、直接受信した信号Ｒｘｄ１、反射波を受信した信号Ｒｘｄ２のうち、後者による出力信号Ｃｄｏｕｔ２がＬｏｗとなるものの、前者によるコンパレータ１５ｃの出力信号Ｃｄｏｕｔ１がＨｉｇｈの信号となる。一方で、付着物等があり異常動作した場合、出力信号Ｃｄｏｕｔ１もＬｏｗとなる。つまり、本実施形態では、出力信号ＣｏｕｔがＬｏｗの場合でも、出力信号Ｃｄｏｕｔ１がＬｏｗ／Ｈｉｇｈのいずれであるかで明示的に付着物の有／無を検知することができる。 However, when there is no deposit or the like, since the threshold Thb is set higher than the threshold Tha on the diagnostic sensor 13 side, the output signal Cdout2 by the latter of the signal Rxd1 directly received and the signal Rxd2 received the reflected wave is Although it is Low, the former output signal Cdout1 of the comparator 15c is a High signal. On the other hand, when an abnormal operation occurs due to an attached substance or the like, the output signal Cdout1 also becomes Low. That is, in this embodiment, even when the output signal Cout is Low, the presence / absence of an adhering substance can be explicitly detected based on whether the output signal Cdout1 is Low / High.
　そして、図示しないが、物体が存在しない場合ではＣｏｕｔがＬｏｗとなり、付着物等により異常動作している場合にＣｄｏｕｔ１，Ｃｄｏｕｔ２がＬｏｗとなり、正常動作している場合にＣｄｏｕｔ１がＨｉｇｈ、Ｃｄｏｕｔ２がＬｏｗとなる。 Although not shown, Cout is Low when no object is present, Cdout1 and Cdout2 are Low when an abnormal operation is caused by an adhering substance or the like, and Cdout1 is High and Cdout2 is Low when the operation is normal. Become.
　このように、本実施形態では、反射波の検出閾値Ｔｈａよりも診断センサ１３での検出閾値Ｔｈｂを高くしておくことで、出力信号ＣｏｕｔがＨｉｇｈ、Ｌｏｗのいずれの場合でも、出力信号Ｃｄｏｕｔ１がＬｏｗ／Ｈｉｇｈのいずれであるかで明示的に付着物の有／無を検知することができるため、付着物が存在した時に検出し易くなる。なお、本実施形態では、閾値を比較しているため、基本的に第２受信部は第１受信部と同じ構造をもつことを前提としている。同じ構造をもたない場合にはその構造の違いを考慮して閾値を決めればよく、また、第３の実施形態と併用する場合には振動伝達体６０での振動のロス分も考慮して閾値を決めればよい。 As described above, in the present embodiment, by setting the detection threshold value Thb in the diagnostic sensor 13 higher than the detection threshold value Tha of the reflected wave, the output signal Cdout1 is output regardless of whether the output signal Cout is High or Low. Since it is possible to explicitly detect the presence / absence of the deposit depending on which of Low / High, it is easy to detect when the deposit is present. In the present embodiment, since the threshold values are compared, it is basically assumed that the second receiving unit has the same structure as the first receiving unit. If they do not have the same structure, the threshold value may be determined in consideration of the difference in structure, and when combined with the third embodiment, the vibration loss in the vibration transmitting body 60 is also taken into consideration. What is necessary is just to determine a threshold value.
（第５の実施形態）
　図９は、本発明の第５の実施形態に係る超音波検知装置における処理例を説明するための図で、図３Ｂに対応した異常動作時の信号例を示す図である。以下、主に第４の実施形態との相違点のみについて説明するが、その他は同様であり、第２，第３の実施形態との併用も可能である。 (Fifth embodiment)
FIG. 9 is a diagram for explaining a processing example in the ultrasonic detection apparatus according to the fifth embodiment of the present invention, and is a diagram illustrating a signal example during an abnormal operation corresponding to FIG. 3B. Hereinafter, only differences from the fourth embodiment will be mainly described, but the others are the same and can be used in combination with the second and third embodiments.
　本実施形態では、第４の実施形態と同様の理由から、診断センサ１３の第２受信部において超音波センサ１１の送信部から送信された超音波を検知するための閾値Ｔｈｂ１を、上述の閾値Ｔｈａより高くすると共に、閾値Ｔｈｂ１に加えて閾値Ｔｈｂ２を設けている。閾値Ｔｈｂ２は基本的に閾値Ｔｈａと同じ値とする。いずれの閾値も付着物が存在しないときの信号レベルに基づき決めておく。閾値Ｔｈａは正常時の反射波によって検知できる値である。 In the present embodiment, for the same reason as in the fourth embodiment, the threshold Thb1 for detecting the ultrasonic wave transmitted from the transmitting unit of the ultrasonic sensor 11 in the second receiving unit of the diagnostic sensor 13 is set to the above-described threshold value. The threshold value Thb2 is provided in addition to the threshold value Thb1. The threshold value Thb2 is basically the same value as the threshold value Tha. Both threshold values are determined based on the signal level when no deposit is present. The threshold value Tha is a value that can be detected by a reflected wave in a normal state.
　図９で例示するように、付着物等による異常動作時には、図８の場合と同様に、超音波センサ１１のコンパレータ１４ｃの出力信号ＣｏｕｔはＬｏｗとなる。このとき、診断センサ１３側では、閾値Ｔｈａと同じ閾値Ｔｈｂ２により、反射波を受信した信号Ｒｘｄ２による出力信号Ｃｄｏｕｔ２がＬｏｗとなるが、閾値Ｔｈａより高い閾値Ｔｈｂ１により、直接受信した信号Ｒｘｄ１によるコンパレータ１５ｃの出力信号Ｃｄｏｕｔ１がＨｉｇｈとなる。一方で、付着物等がある場合（異常動作時）には、出力信号Ｃｄｏｕｔ１もＬｏｗとなる。つまり、本実施形態では、出力信号ＣｏｕｔがＬｏｗの場合でも、出力信号Ｃｄｏｕｔ１がＬｏｗ／Ｈｉｇｈのいずれであるかで明示的に付着物の有／無を検知することができる。 As illustrated in FIG. 9, during an abnormal operation due to a deposit or the like, the output signal Cout of the comparator 14 c of the ultrasonic sensor 11 becomes Low as in the case of FIG. 8. At this time, on the diagnostic sensor 13 side, the output signal Cdout2 by the signal Rxd2 that has received the reflected wave becomes Low by the same threshold Thb2 as the threshold Tha, but the comparator 15c by the signal Rxd1 directly received by the threshold Thb1 that is higher than the threshold Tha. Output signal Cdout1 becomes High. On the other hand, when there is a deposit or the like (during abnormal operation), the output signal Cdout1 is also Low. That is, in this embodiment, even when the output signal Cout is Low, the presence / absence of an adhering substance can be explicitly detected based on whether the output signal Cdout1 is Low / High.
　そして、図示しないが、物体が存在しない場合ではＣｏｕｔがＬｏｗとなり、付着物等により異常動作している場合にＣｄｏｕｔ１，Ｃｄｏｕｔ２がＬｏｗとなり、正常動作している場合にＣｄｏｕｔ１がＨｉｇｈ、Ｃｄｏｕｔ２がＬｏｗとなる。 Although not shown, Cout is Low when no object is present, Cdout1 and Cdout2 are Low when an abnormal operation is caused by an adhering substance or the like, and Cdout1 is High and Cdout2 is Low when the operation is normal. Become.
　このように、本実施形態では、診断用に２つの閾値を用いることで、出力信号ＣｏｕｔがＨｉｇｈ、Ｌｏｗのいずれの場合でも、出力信号Ｃｄｏｕｔ１がＬｏｗ／Ｈｉｇｈのいずれであるかで明示的に付着物の有／無を検知することができるため、付着物が存在した時にさらに検出し易くなる。なお、本実施形態でも、閾値を比較しているため、基本的に第２受信部は第１受信部と同じ構造をもつことを前提としている。しかし、例えば閾値Ｔｈｂ２は閾値Ｔｈａと全く同じでなくてもよい。同じ構造をもたない場合にはその構造の違いを考慮して閾値を決めればよく、また、第３の実施形態と併用する場合には振動伝達体６０での振動のロス分も考慮して閾値を決めればよい。 As described above, in this embodiment, by using two threshold values for diagnosis, whether the output signal Cdout1 is Low / High is explicitly added regardless of whether the output signal Cout is High or Low. Since presence / absence of a kimono can be detected, it becomes easier to detect when there is a deposit. In this embodiment, since the threshold values are compared, it is basically assumed that the second receiving unit has the same structure as the first receiving unit. However, for example, the threshold value Thb2 may not be exactly the same as the threshold value Tha. If they do not have the same structure, the threshold value may be determined in consideration of the difference in structure, and when combined with the third embodiment, the vibration loss in the vibration transmitting body 60 is also taken into consideration. What is necessary is just to determine a threshold value.
　特に閾値Ｔｈｂ２が閾値Ｔｈａと異なる場合（例えば同じ構造を採用してもＴｈｂ２＜Ｔｈａの場合）には、出力信号ＣｏｕｔがＬｏｗの場合において、出力信号Ｃｄｏｕｔ１，Ｃｄｏｕｔ２がＨｉｇｈとなることも多々起こり得る。この場合には、診断センサ１３において反射波からも付着物がないことが検知でき、直接の超音波からの検知とのダブルチェックが可能となる。 In particular, when the threshold value Thb2 is different from the threshold value Tha (for example, even if the same structure is adopted, if Thb2 <Tha), the output signals Cdout1 and Cdout2 may be High when the output signal Cout is Low. . In this case, the diagnostic sensor 13 can detect that there is no deposit from the reflected wave, and double check with detection from direct ultrasonic waves is possible.
　また、別の処理例として、閾値Ｔｈｂ２が閾値Ｔｈａと同じか否かに拘わらず、反射波による出力信号ＣｏｕｔがＬｏｗになった場合に、診断センサ１３において閾値Ｔｈｂ１，Ｔｈｂ２に関するＣｄｏｕｔ１，Ｃｄｏｕｔ２の一方のみがＬｏｗとなっていれば、付着物が存在することが確定できないと判定し、単にユーザに注意を喚起するだけにしてもよい。そのような処理を採用した構成では、Ｃｏｕｔ，Ｃｄｏｕｔ１，Ｃｄｏｕｔ２がいずれもＬｏｗとなった場合、測定値の破棄やエラー情報等の報知を行えばよい。 As another processing example, when the output signal Cout by the reflected wave becomes Low regardless of whether or not the threshold Thb2 is the same as the threshold Tha, one of Cdout1 and Cdout2 related to the thresholds Thb1 and Thb2 in the diagnostic sensor 13 If only “Low” is set to Low, it may be determined that there is no deposit, and the user may simply be alerted. In the configuration employing such processing, when all of Cout, Cdout1, and Cdout2 are Low, the measurement value may be discarded or error information may be notified.
（第６の実施形態）
　第５の実施形態で説明した２つの閾値を用いる方法は、超音波センサ１１の第１受信部と診断センサ１３の第２受信部とを兼用した場合にも適用でき、コストを下げる効果を奏する。このような構成例を第６の実施形態として説明する。 (Sixth embodiment)
The method using the two threshold values described in the fifth embodiment can be applied to the case where the first receiving unit of the ultrasonic sensor 11 and the second receiving unit of the diagnostic sensor 13 are combined, and has an effect of reducing the cost. . Such a configuration example will be described as a sixth embodiment.
　図１０Ａは、本実施形態に係る超音波検知装置の一構成例を示すブロック図で、図１Ａの超音波検知装置の他の構成例を示すブロック図でもあり、図１０Ｂは、その回路構成例を示す図である。図１１Ａ、図１１Ｂはそれぞれ、図１０Ｂの超音波検知装置における正常動作時、異常動作時の処理例を説明するための図である。以下、主に第１，第５の実施形態との相違点のみについて説明するが、その他は同様である。 FIG. 10A is a block diagram illustrating a configuration example of the ultrasonic detection apparatus according to the present embodiment, is also a block diagram illustrating another configuration example of the ultrasonic detection apparatus of FIG. 1A, and FIG. 10B is a circuit configuration example thereof. FIG. FIG. 11A and FIG. 11B are diagrams for explaining processing examples during normal operation and abnormal operation in the ultrasonic detection apparatus of FIG. 10B, respectively. Hereinafter, only differences from the first and fifth embodiments will be mainly described, but the other points are the same.
　図１０Ａ，図１０Ｂで例示する超音波検知装置１００について、図４Ａ，図４Ｂの超音波検知装置４の構成例と比較して説明する。超音波検知装置１００は、ＭＰＵ４０、送信部４１ａ、アンプ４４ａにそれぞれ対応するＭＰＵ１１０、送信部１１１ａ、アンプ１１４ａを有すると共に、受信部４１ｂと受信部１３ａとを兼ねた受信部１１１ｂと、アンプ・コンパレータ４４ｂ，１５の双方を兼ねたアンプ・コンパレータ１１４ｂを有する。アンプ・コンパレータ１１４ｂにおける符号１１４ｂａ，１１４ｂｂ，１１４ｂｃはそれぞれ図４Ｂの符号４４ｂａ（１５ａ），４４ｂｂ（１５ｂ），４４ｂｃ（１５ｃ）と同じ構成である。 The ultrasonic detection apparatus 100 illustrated in FIGS. 10A and 10B will be described in comparison with the configuration example of the ultrasonic detection apparatus 4 in FIGS. 4A and 4B. The ultrasonic detection apparatus 100 includes an MPU 110, a transmission unit 111a, and an amplifier 114a corresponding to the MPU 40, the transmission unit 41a, and the amplifier 44a, and a reception unit 111b that also serves as the reception unit 41b and the reception unit 13a, and an amplifier / comparator. 44b and 15 has an amplifier / comparator 114b. Reference numerals 114ba, 114bb and 114bc in the amplifier / comparator 114b have the same configurations as the reference numerals 44ba (15a), 44bb (15b) and 44bc (15c) in FIG. 4B, respectively.
　アンプ・コンパレータ１１４ｂは、閾値Ｔｈ１用と閾値Ｔｈ２用に２つのコンパレータ基準閾値の格納部１１４ｂｄ，１１４ｂｅを有する。閾値Ｔｈ２は上述した閾値Ｔｈａ及び閾値Ｔｈｂ２に対応し、閾値Ｔｈ１は上述した閾値Ｔｈｂ１に対応するものである。いずれの閾値も付着物が存在しないときの信号レベルに基づき決めておく。 The amplifier / comparator 114b has two comparator reference threshold storage units 114bd and 114be for the threshold Th1 and the threshold Th2. The threshold value Th2 corresponds to the above-described threshold value Tha and threshold value Thb2, and the threshold value Th1 corresponds to the above-described threshold value Thb1. Both threshold values are determined based on the signal level when no deposit is present.
　そして、検知できる物体がある場合の波形例を図１１Ａ，図１１Ｂで示すように、超音波検知装置１００は、送信部１１１ａで送信された超音波信号Ｔｘに対し、受信部１１１ｂが信号Ｒｘ１を受信すると共に、超音波信号Ｔｘの反射波として信号Ｒｘ２も受信する。信号Ｒｄ１，Ｒｄ２のそれぞれに対し、アンプ１１４ｂａの出力はＡｏｕｔ１，Ａｏｕｔ２、コンパレータ１１４ｂｃの入力はＣｄｉｎ，Ｃｉｎ、コンパレータ１１４ｂｃの出力（ＭＰＵ１１０への入力）はＣｄｏｕｔ，Ｃｏｕｔとなる。 Then, as shown in FIGS. 11A and 11B, when the object that can be detected is shown in FIG. 11A and FIG. 11B, in the ultrasonic detection device 100, the reception unit 111 b outputs the signal Rx 1 to the ultrasonic signal Tx transmitted by the transmission unit 111 a. In addition to reception, the signal Rx2 is also received as a reflected wave of the ultrasonic signal Tx. For each of the signals Rd1 and Rd2, the output of the amplifier 114ba is Aout1 and Aout2, the input of the comparator 114bc is Cdin and Cin, and the output of the comparator 114bc (input to the MPU 110) is Cdout and Cout.
　物体が存在する場合で且つ正常動作している場合には、図１１Ａに示すように、反射波を閾値Ｔｈ２で検知した場合の反射波信号であるＣｏｕｔがＨｉｇｈとなり、距離計測や障害物検知が可能となると共に、超音波送信面から出射された超音波信号Ｔｘを直接受信して閾値Ｔｈ１で検出した場合の自己診断信号であるＣｄｏｕｔもＨｉｇｈとなる。 When an object exists and is operating normally, as shown in FIG. 11A, Cout, which is a reflected wave signal when the reflected wave is detected at the threshold Th2, becomes High, and distance measurement and obstacle detection are performed. Cdout, which is a self-diagnosis signal when the ultrasonic signal Tx emitted from the ultrasonic transmission surface is directly received and detected with the threshold Th1, is also High.
　一方で、物体が存在する場合で且つ付着物等により異常動作している場合には、図１１Ｂに示すように、反射波信号であるＣｏｕｔがＬｏｗとなり、距離計測や障害物検知できていないだけでなく、自己診断信号であるＣｄｏｕｔも超音波信号Ｔｘ自体が弱いためにＬｏｗとなる。 On the other hand, when an object is present and abnormal operation is caused by an attached object or the like, as shown in FIG. 11B, Cout that is a reflected wave signal is Low, and distance measurement and obstacle detection are not performed. In addition, Cdout, which is a self-diagnosis signal, also becomes Low because the ultrasonic signal Tx itself is weak.
　そして、図示しないが、物体が存在しない場合ではＣｏｕｔがＬｏｗとなり、付着物等により異常動作している場合にＣｄｏｕｔもＬｏｗとなり、正常動作している場合にＣｄｏｕｔはＨｉｇｈとなる。 Although not shown, Cout is Low when no object is present, Cdout is Low when an abnormal operation is caused by a deposit or the like, and Cdout is High when the object is operating normally.
　このように、本実施形態では診断用に２つの閾値を用いることで、出力信号ＣｏｕｔがＨｉｇｈ、Ｌｏｗのいずれの場合でも、出力信号ＣｄｏｕｔがＬｏｗ／Ｈｉｇｈのいずれであるかで明示的に付着物の有／無を検知することができため、付着物が存在した時にさらに検出し易くなる。 As described above, in this embodiment, by using two threshold values for diagnosis, whether the output signal Cdout is Low / High is explicitly attached regardless of whether the output signal Cout is High or Low. The presence / absence of the presence / absence can be detected, so that it becomes easier to detect when the deposit is present.
　ここで、受信部１１１ｂの配置について説明する。上述のように、超音波検知装置１００は、超音波信号Ｔｘを直接信号Ｒｘ１として受信する必要があり、且つ診断センサを別途設けておらず、且つ信号Ｒｘ１用の閾値Ｔｈ１を設けている。よって、本実施形態において、送信部１１１ａと受信部１１１ｂは別々の素子で構成されている。 Here, the arrangement of the receiving unit 111b will be described. As described above, the ultrasonic detection apparatus 100 needs to receive the ultrasonic signal Tx directly as the signal Rx1, does not have a separate diagnostic sensor, and has a threshold Th1 for the signal Rx1. Therefore, in this embodiment, the transmission part 111a and the receiving part 111b are comprised by the separate element.
　そして、送信部１１１ａの超音波送信面と受信部１１１ｂの超音波受信面とは、近接していることが距離測定などには好適であるが、離間していてもよい。よって、それぞれ図１Ａ等における超音波センサ１１、診断センサ１３のような位置に配設してもよい。また、本実施形態でも、第２，第３の実施形態のような振動伝達体や窪みへの設置などの応用例が適用できる。 And it is suitable for the distance measurement etc. that the ultrasonic transmission surface of the transmission unit 111a and the ultrasonic reception surface of the reception unit 111b are close to each other, but they may be separated. Therefore, the ultrasonic sensor 11 and the diagnostic sensor 13 in FIG. Also in this embodiment, application examples such as installation in a vibration transmitting body or a depression as in the second and third embodiments can be applied.
１…超音波検知装置、１１…超音波センサ、１２…ホーン、１３…診断用超音波センサ（診断センサ）、Ｄ…付着物。 DESCRIPTION OF SYMBOLS 1 ... Ultrasonic detector, 11 ... Ultrasonic sensor, 12 ... Horn, 13 ... Ultrasonic sensor for diagnosis (diagnostic sensor), D ... Adhesion.

Claims (6)

  1. 　超音波を送信する送信部及び該超音波を受信する第１受信部を有する反射型の超音波センサを備えた超音波検知装置であって、
    　前記送信部における超音波送信面の近傍に診断用超音波センサを、さらに備え、
    　前記診断用超音波センサは、前記超音波送信面から送信された超音波を受信する第２受信部を有し、該第２受信部での受信結果に基づき前記超音波送信面に付着した付着物の有無を検知することを特徴とする超音波検知装置。     An ultrasonic detection apparatus including a reflection type ultrasonic sensor having a transmission unit that transmits ultrasonic waves and a first reception unit that receives the ultrasonic waves,
    A diagnostic ultrasonic sensor is further provided in the vicinity of the ultrasonic transmission surface in the transmission unit,
    The diagnostic ultrasonic sensor has a second receiving unit that receives ultrasonic waves transmitted from the ultrasonic transmission surface, and is attached to the ultrasonic transmission surface based on a reception result at the second receiving unit. An ultrasonic detector characterized by detecting the presence or absence of a kimono.
  2. 　前記診断用超音波センサは、前記超音波送信面から送信された超音波を受信する受信面が前記超音波送信面に対してほぼ垂直になるように配設されていることを特徴とする請求項１に記載の超音波検知装置。 The diagnostic ultrasonic sensor is arranged such that a receiving surface that receives ultrasonic waves transmitted from the ultrasonic transmission surface is substantially perpendicular to the ultrasonic transmission surface. Item 2. The ultrasonic detection device according to Item 1.
  3. 　前記第１受信部の超音波受信面は、前記超音波送信面と共通の面であることを特徴とする請求項１又は２に記載の超音波検知装置。 The ultrasonic detection apparatus according to claim 1, wherein an ultrasonic reception surface of the first reception unit is a common surface with the ultrasonic transmission surface.
  4. 　前記超音波センサに取り付けられたホーンをさらに備え、
    　前記診断用超音波センサの受信面は、前記ホーンに取り付けられていることを特徴とする請求項１～３のいずれか１項に記載の超音波検知装置。     Further comprising a horn attached to the ultrasonic sensor,
    The ultrasonic detection device according to any one of claims 1 to 3, wherein a receiving surface of the diagnostic ultrasonic sensor is attached to the horn.
  5. 　前記超音波センサに取り付けられたホーンと、
    　該ホーンの内周面又は外周面を周回し、前記超音波送信面からの超音波の振動を前記診断用超音波センサの受信面に伝達させる振動伝達体と、
    をさらに備えたことを特徴とする請求項１～３のいずれか１項に記載の超音波検知装置。     A horn attached to the ultrasonic sensor;
    A vibration transmission body that orbits the inner peripheral surface or outer peripheral surface of the horn and transmits ultrasonic vibration from the ultrasonic transmission surface to the reception surface of the diagnostic ultrasonic sensor;
    The ultrasonic detection device according to any one of claims 1 to 3, further comprising:
  6. 　前記超音波センサに取り付けられたホーンをさらに備え、
    　該ホーンは内周面の一部に窪みを有し、
    　前記診断用超音波センサは、前記診断用超音波センサの受信面が前記窪みに位置し前記内周面側を向くように取り付けられていることを特徴とする請求項１～３のいずれか１項に記載の超音波検知装置。     Further comprising a horn attached to the ultrasonic sensor,
    The horn has a depression in a part of the inner peripheral surface,
    4. The diagnostic ultrasonic sensor is attached so that a receiving surface of the diagnostic ultrasonic sensor is located in the recess and faces the inner peripheral surface side. The ultrasonic detection device according to item.
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Citations (3)

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JPS6327779A (en) * 1986-07-22 1988-02-05 Matsushita Electric Works Ltd Obstacke detector for vehicle
JPH0571781U (en) * 1992-02-27 1993-09-28 株式会社カイジョー Doppler sound wave radar transceiver
JP2002131428A (en) * 2000-10-25 2002-05-09 Mitsubishi Electric Corp Ultrasonic obstacle detecting device

Patent Citations (3)

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Publication number Priority date Publication date Assignee Title
JPS6327779A (en) * 1986-07-22 1988-02-05 Matsushita Electric Works Ltd Obstacke detector for vehicle
JPH0571781U (en) * 1992-02-27 1993-09-28 株式会社カイジョー Doppler sound wave radar transceiver
JP2002131428A (en) * 2000-10-25 2002-05-09 Mitsubishi Electric Corp Ultrasonic obstacle detecting device

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