WO2020208705A1 - Obstacle detection device - Google Patents

Obstacle detection device Download PDF

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Publication number
WO2020208705A1
WO2020208705A1 PCT/JP2019/015453 JP2019015453W WO2020208705A1 WO 2020208705 A1 WO2020208705 A1 WO 2020208705A1 JP 2019015453 W JP2019015453 W JP 2019015453W WO 2020208705 A1 WO2020208705 A1 WO 2020208705A1
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WIPO (PCT)
Prior art keywords
wave
unit
transmission
correlation function
obstacle
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PCT/JP2019/015453
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French (fr)
Japanese (ja)
Inventor
武史 羽鳥
敏 川村
井上　悟
幹次 北村
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三菱電機株式会社
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Application filed by 三菱電機株式会社 filed Critical 三菱電機株式会社
Priority to PCT/JP2019/015453 priority Critical patent/WO2020208705A1/en
Publication of WO2020208705A1 publication Critical patent/WO2020208705A1/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
    • G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
    • G01S15/02—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems using reflection of acoustic waves
    • G01S15/06—Systems determining the position data of a target
    • G01S15/08—Systems for measuring distance only
    • G01S15/10—Systems for measuring distance only using transmission of interrupted, pulse-modulated waves

Definitions

  • the present invention relates to an obstacle detection device that detects an obstacle using ultrasonic waves.
  • the obstacle detector Since ultrasonic waves propagate in a gas or liquid medium, the obstacle detector transmits the ultrasonic waves toward the obstacle and receives the ultrasonic waves reflected by the obstacle, so that the propagation time of the ultrasonic waves is long. Can be sought. Since the propagation speed of ultrasonic waves in the medium is constant, the distance to the obstacle is calculated as 1/2 of the propagation distance of ultrasonic waves obtained by multiplying the propagation time by the propagation speed.
  • This obstacle detection device is being considered for application to automatic parking of vehicles, etc., but interference between the ultrasonic signal transmitted by the own vehicle and the ultrasonic signal transmitted by another vehicle is an issue.
  • a method of identifying a plurality of ultrasonic signals by transmitting ultrasonic signals based on a pseudo-random sequence having low cross-correlation has been proposed (see, for example, Patent Document 1).
  • the conventional obstacle detection device when the transmitted ultrasonic signal based on the pseudo-random sequence receives different Doppler shifts and returns in duplicate in time, it is difficult to remove the Doppler shift and the ultrasonic signal is received.
  • the ultrasonic signal cannot be decoded. Therefore, the conventional obstacle detection device needs to compensate for the signal deformation in the propagation path such as the Doppler shift in order to identify a plurality of ultrasonic signals.
  • the present invention has been made to solve the above problems, and an object of the present invention is to identify a plurality of ultrasonic signals without compensating for signal deformation in the propagation path.
  • the obstacle detection device has a transmission wave generation unit that generates a transmission wave, a transmission wave deformation unit that divides or duplicates the transmission wave to generate a deformed transmission wave, and an ultrasonic element, and transmits.
  • a transmitter / receiver that transmits waves and deformed transmitted waves as ultrasonic waves, receives ultrasonic waves reflected by obstacles and outputs received waves, and shaped reception that shapes the received waves based on the deformed contents of the transmitted wave deformed section.
  • the correlation function calculation unit that calculates the correlation function between the received wave and the shaped reception wave, and the correlation function calculated by the correlation function calculation unit. It is provided with an extraction unit for extracting the components to be used.
  • the correlation function between the received wave subjected to the signal deformation in the propagation path and the shaped received wave is calculated, the correlation function is calculated at the reflection position of the own ultrasonic wave without compensating for the signal deformation. Since the value is large, a plurality of ultrasonic signals can be identified.
  • FIG. 6 is a graph showing an example of a correlation function output by the correlation function calculation unit 13 of the first embodiment.
  • FIG. It is a block diagram which shows the structural example of the obstacle detection apparatus 16 which concerns on Embodiment 2.
  • FIG. It is a graph which shows the example of the transmission wave and the transformation transmission wave output by the transmission wave transformation part 3 of Embodiment 2. It is a figure which shows the obstacle arrangement example in Embodiment 2, and is the state which the parking lot is seen from the top. It is a graph which shows the example of the received wave output by the receiving circuit 11 of Embodiment 2. It is a graph which shows the example of the received wave output by the receiving circuit 11 of Embodiment 2. It is a block diagram which shows the structural example of the shaping part 12a in Embodiment 2.
  • FIG. 1 It is a block diagram which shows the structural example of the obstacle detection apparatus 16-1 which concerns on Embodiment 3. It is a figure which shows the obstacle arrangement example in Embodiment 3, and is the state which looked at the periphery of own vehicle 17 from above. It is a graph which shows the example of the transmission wave and the deformation transmission wave which the transmission wave deformation part 3 of the obstacle detection apparatus 16-1 which concerns on Embodiment 3 output. It is a graph which shows the example of the transmission wave and the deformation transmission wave which the transmission wave deformation part 3 of the obstacle detection apparatus 16-2 which concerns on Embodiment 3 output. It is a graph which shows the example of the received wave output by the receiving circuit 11 of the obstacle detection apparatus 16-1 which concerns on Embodiment 3. FIG.
  • FIG. It is a graph which shows the example of the value of the correlation function and the received power calculated by the local terminal signal detection unit 18-1 of Embodiment 4. It is a graph which shows the example of the ratio of the correlation function with respect to the received power calculated by the local terminal signal detection unit 18-1 of Embodiment 4. It is a graph which shows the example of the value of the correlation function and the received power calculated by the other terminal signal detection unit 18-2 of Embodiment 4.
  • FIG. 1 is a block diagram showing a configuration example of the obstacle detection device 16 according to the first embodiment.
  • the obstacle detection device 16 is mounted on a vehicle and detects obstacles 7 existing around the vehicle.
  • the vehicle equipped with the obstacle detection device 16 is referred to as "own vehicle”.
  • the obstacle detection device 16 includes a transmission wave generation unit 1, a deformation content setting unit 2, a transmission wave deformation unit 3, a transmission / reception unit 15, a shaping unit 12, a correlation function calculation unit 13, and an extraction unit 14.
  • the transmission / reception unit 15 includes a transmission circuit 4, an ultrasonic transmission element 5, an ultrasonic reception element 10, and a reception circuit 11.
  • the transmission wave generation unit 1 generates a transmission wave and outputs it to the transmission wave deformation unit 3. Further, the transmission wave generation unit 1 outputs the signal length of the generated transmission wave to the correlation function calculation unit 13.
  • the transmitted wave generated by the transmitted wave generation unit 1 is a burst wave or the like.
  • the transmitted wave may be modulated at least one of amplitude, phase, or frequency.
  • the deformation content setting unit 2 holds the deformation content of the transmission wave generated by the transmission wave generation unit 1, and sets this deformation content for the transmission wave deformation unit 3 and the shaping unit 12.
  • the modification includes at least one of a time shift, a phase shift, or a frequency shift.
  • the transmission wave deformation unit 3 divides or duplicates the transmission wave generated by the transmission wave generation unit 1, and one of the divided transmission waves or the duplicated transmission wave is based on the deformation content set by the transformation content setting unit 2. Transforms.
  • the transmission wave deformation unit 3 outputs the transmission wave and the deformed transmission wave (hereinafter, referred to as “deformed transmission wave”) to the transmission circuit 4.
  • the transformation content set by the transformation content setting unit 2 may include an instruction as to whether to divide or duplicate the transmitted wave.
  • the transmission circuit 4 converts the transmission wave from the transmission wave deformation unit 3 and the deformation transmission wave into a voltage that can be applied to the ultrasonic transmission element 5.
  • the transmission circuit 4 is, for example, a drive circuit that generates a voltage having a binary waveform.
  • the ultrasonic transmission element 5 converts the voltage applied from the transmission circuit 4 into ultrasonic waves and transmits them to space.
  • the ultrasonic waves transmitted from the ultrasonic wave transmitting element 5 of the own vehicle are referred to as the own vehicle signal 6.
  • the own vehicle signal echo 8 what the own vehicle signal 6 propagating in space is reflected by the obstacle 7 is called the own vehicle signal echo 8.
  • ultrasonic waves transmitted from another vehicle are referred to as another vehicle signal 9.
  • the ultrasonic receiving element 10 converts the pressure applied by ultrasonic waves such as the own vehicle signal echo 8 and the other vehicle signal 9 into a voltage and outputs it to the receiving circuit 11.
  • the ultrasonic transmitting element 5 and the ultrasonic receiving element 10 are, for example, piezoelectric ceramics widely used for automobiles.
  • the obstacle detection device 16 in FIG. 1 uses different ultrasonic elements for transmitting and receiving ultrasonic waves, one ultrasonic element may be used for both transmission and reception. In that case, for example, one ultrasonic element alternately transmits and receives.
  • the receiving circuit 11 amplifies the voltage output from the ultrasonic receiving element 10, samples the amplified voltage, converts it into digital data, and outputs the converted digital data as a receiving wave to the shaping unit 12. Note that the receiving circuit 11 may use a physical filter to remove noise before sampling the voltage.
  • the shaping unit 12 shapes the received wave output from the receiving circuit 11 so that the similarity between the received wave and the received wave after shaping can be determined based on the deformation content set by the deformation content setting unit 2. ..
  • the shaping unit 12 outputs the received wave and the shaped received wave (hereinafter, referred to as “shaped received wave”) to the correlation function calculation unit 13.
  • the correlation function calculation unit 13 calculates a cross-correlation function between the received wave from the shaping unit 12 and the shaped reception wave, and outputs the time series data as the calculation result to the extraction unit 14.
  • the correlation function calculation unit 13 sets the length of the time window at the time of the correlation function calculation by using the signal length of the transmission wave output from the transmission wave generation unit 1.
  • the extraction unit 14 extracts a component corresponding to the transmission wave of the own vehicle (that is, the own vehicle signal 6) from the received wave based on the correlation function calculated by the correlation function calculation unit 13.
  • the extraction unit 14 extracts the vehicle signal 6.
  • the extraction unit 14 outputs the propagation time of the own vehicle signal 6, which is the extraction position of the own vehicle signal 6, as an obstacle position.
  • FIG. 2 is a graph showing an example of a transmitted wave output by the transmitted wave generation unit 1 of the first embodiment.
  • 3A, 3B, 3C, and 3D are graphs showing an example of a transmission wave and a deformation transmission wave output by the transmission wave deformation unit 3 of the first embodiment.
  • the horizontal axis is the time when the transmission start time of the ultrasonic wave transmitting element 5 is 0 ms, and the vertical axis is the frequency.
  • the transmission wave generation unit 1 generates a burst wave having a frequency of 48 kHz and a signal length of 0.5 ms as a transmission wave.
  • the transmission wave transformation unit 3 duplicates the transmission wave and shifts it by 2ms time as shown in FIG. 3A. Generates a modified transmitted wave.
  • the transmission wave deformation unit 3 duplicates the transmitted wave and shifts the frequency by 3 kHz as shown in FIG. 3B. Generate.
  • the transmitted wave transforming unit 3 duplicates the transmitted wave and shifts it by 2 ms time and 3 kHz as shown in FIG. 3C. Generates a frequency-shifted modified transmitted wave.
  • the transmission wave deformation unit 3 divides the transmission wave as shown in FIG. 3D, and the divided one is used as the transmission wave. , The other is shifted by 2 ms to obtain a modified transmitted wave.
  • the transmission wave and the modified transmission wave shown in FIG. 3A are transmitted from the ultrasonic transmission element 5 as the own vehicle signal 6 will be used as an example.
  • the own vehicle signal 6 is reflected by the obstacle 7 to become the own vehicle signal echo 8, and returns to the ultrasonic receiving element 10. Further, it is assumed that the own vehicle signal echo 8 has a Doppler shift of 1 kHz due to the traveling of the own vehicle.
  • the ultrasonic receiving element 10 receives the own vehicle signal echo 8 and the other vehicle signal 9 which is an interference wave transmitted from another vehicle, converts it into a voltage, and outputs it to the receiving circuit 11.
  • the receiving circuit 11 amplifies and samples the voltage output from the ultrasonic receiving element 10, and outputs it as a received wave.
  • FIG. 4 is a graph showing an example of a received wave output by the receiving circuit 11 of the first embodiment.
  • the horizontal axis of the graph is the propagation time with the transmission start time of the ultrasonic wave transmitting element 5 as 0 ms, and the vertical axis is the frequency.
  • the received wave includes the own vehicle signal echo 8 in which the own vehicle signal 6 is reflected by the obstacle 7, and the other vehicle signal 9 transmitted by the other vehicle.
  • the frequency of the own vehicle signal 6 changes from 48 kHz to 49 kHz due to the Doppler shift.
  • the other vehicle signal 9 is a burst wave having a frequency of 47 kHz and a signal length of 0.75 ms.
  • FIG. 5 is a graph showing an example of a shaped received wave output by the shaping unit 12 of the first embodiment.
  • the horizontal axis of the graph is the propagation time, and the vertical axis is the frequency. Since the modified content here is to shift the duplicated transmitted wave by 2 ms time, the shaping unit 12 generates a shaped received wave obtained by shifting the received wave by -2 ms in order to return this time shift. ..
  • the shaping unit 12 outputs the received wave before shaping and the shaped received wave after shaping to the correlation function calculation unit 13.
  • the correlation function calculation unit 13 calculates the correlation function between the received wave shown in FIG. 4 and the shaped received wave shown in FIG.
  • the length of the time window at the time of the correlation function calculation is 0.5 ms, which is the signal length of the transmitted wave output from the transmitted wave generation unit 1.
  • FIG. 6 is a graph showing an example of the correlation function output by the correlation function calculation unit 13 of the first embodiment.
  • the horizontal axis of the graph is the propagation time, and the vertical axis is the value of the correlation function.
  • the extraction unit 14 compares the value of the correlation function output from the correlation function calculation unit 13 with the predetermined threshold value TH1. Since the value of the correlation function around 11.5 ms is equal to or higher than the threshold value TH1, the extraction unit 14 extracts the received wave near 11.5 ms as the own vehicle signal 6. On the other hand, the value of the correlation function between the received wave and the shaped received wave, which corresponds to the other vehicle signal 9, is less than the threshold value TH1, and is not extracted by the extraction unit 14. Therefore, the extraction unit 14 can distinguish between the own vehicle signal 6 and the other vehicle signal 9. Since the own vehicle signal 6 is attenuated as the propagation distance becomes longer, the value of the threshold value TH1 may change with the passage of the propagation time.
  • the obstacle detection device 16 extracts the transmission wave generation unit 1, the transmission wave deformation unit 3, the transmission / reception unit 15, the shaping unit 12, the correlation function calculation unit 13, and the correlation function calculation unit 13.
  • a unit 14 is provided.
  • the transmission wave generation unit 1 generates a transmission wave.
  • the transmission wave deformation unit 3 divides or duplicates the transmission wave to generate a deformed transmission wave.
  • the transmission / reception unit 15 transmits the transmission wave and the modified transmission wave as the own vehicle signal 6, receives the own vehicle signal echo 8 reflected by the obstacle 7, and outputs the received wave.
  • the shaping unit 12 generates a shaped reception wave in which the received wave is shaped based on the deformation content of the transmission wave deformation unit 3.
  • the correlation function calculation unit 13 calculates the correlation function between the received wave and the shaped received wave.
  • the extraction unit 14 extracts a component corresponding to the own vehicle signal 6 from the received wave based on the correlation function calculated by the correlation function calculation unit 13.
  • the obstacle detection device 16 calculates the correlation function between the received wave and the shaped received wave, it correlates at the reflection position of the own vehicle signal 6 without compensating for the signal deformation in the propagation path such as Doppler shift.
  • the value of the function becomes large, and the own vehicle signal 6 can be extracted. Therefore, the obstacle detection device 16 can distinguish between the own vehicle signal 6 and the other vehicle signal 9.
  • the transmitted wave is phase-modulated based on a pseudo-random sequence for the purpose of identifying a plurality of ultrasonic signals.
  • the obstacle detection device 16 of the first embodiment can distinguish the own vehicle signal 6 from the other vehicle signal 9 without performing phase modulation, so that the life of the piezoelectric ceramics can be maintained.
  • the transmission wave deformation unit 3 generates a deformation transmission wave in which at least one of the frequency and time of the transmission wave is shifted. Therefore, the transmitted wave is easily deformed. In addition, it is easy to shape the received wave based on this modification.
  • FIG. 7 is a block diagram showing a configuration example of the obstacle detection device 16 according to the second embodiment.
  • the obstacle detection device 16 according to the second embodiment includes a shaping unit 12a and an extraction unit 14a in place of the shaping unit 12 and the extraction unit 14 in the obstacle detection device 16 of the first embodiment shown in FIG. It is a composition.
  • the same or corresponding parts as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.
  • FIG. 8 is a graph showing an example of a transmission wave and a deformation transmission wave output by the transmission wave deformation unit 3 of the second embodiment.
  • the horizontal axis of the graph is the time when the transmission start time of the ultrasonic wave transmitting element 5 is 0 ms, and the vertical axis is the frequency.
  • the transmission wave generation unit 1 generates a burst wave having a frequency of 45 kHz and a signal length of 1 ms as the transmission wave.
  • the transmission wave deformation unit 3 is based on this transformation content and has a frequency of 51 kHz. To generate.
  • the transmission wave and the modified transmission wave shown in FIG. 8 are transmitted from the ultrasonic transmission element 5 as the own vehicle signal 6.
  • FIG. 9 is a diagram showing an example of obstacle placement in the second embodiment, and is a state in which the parking lot is viewed from above.
  • the own vehicle 17 is temporarily stopped, and is about to automatically park using the information of obstacles 7a, 7b, and 7c detected by the obstacle detection device 16.
  • the motorcycle which is an obstacle 7a, is approaching its own vehicle 17 at 14 km / h.
  • the other vehicle which is the obstacle 7b, is stopped in the parking lot and transmits the other vehicle signal 9.
  • the other vehicle, which is an obstacle 7c is moving away from the own vehicle 17 at 20 km / h.
  • the distance between the own vehicle 17 and the obstacle 7a is 197 cm
  • the distance between the own vehicle 17 and the obstacle 7b is 202 cm
  • the distance between the own vehicle 17 and the obstacle 7c is 210 cm.
  • the ultrasonic transmitting element 5 and the ultrasonic receiving element 10 of the obstacle detection device 16 are installed in the front part of the own vehicle 17.
  • the own vehicle signal 6 transmitted from the ultrasonic transmitting element 5 is reflected by obstacles 7a, 7b, and 7c to become the own vehicle signal echo 8, and returns to the ultrasonic receiving element 10.
  • the ultrasonic receiving element 10 receives the own vehicle signal echo 8 and the other vehicle signal 9 which is an interference wave transmitted from the obstacle 7b, converts them into a voltage, and outputs them to the receiving circuit 11.
  • the receiving circuit 11 amplifies and samples the voltage output from the ultrasonic receiving element 10, and outputs it as a received wave.
  • the horizontal axis of the graph in FIG. 10 is the propagation time with the transmission start time of the ultrasonic wave transmitting element 5 as 0 ms, and the vertical axis is the frequency.
  • the horizontal axis of the graph in FIG. 11 is the propagation time with the transmission start time of the ultrasonic wave transmitting element 5 as 0 ms, and the vertical axis is the voltage value.
  • the received wave corresponding to the own vehicle signal 6 is divided into two groups surrounded by a broken line. The group with short propagation time and low frequency corresponds to the transmitted wave.
  • a group having a long propagation time and a high frequency corresponds to a modified transmitted wave.
  • the received wave having the highest frequency is the own vehicle signal 6 reflected by the obstacle 7a
  • the received wave having the second highest frequency is reflected by the obstacle 7b.
  • the own vehicle signal 6 is the own vehicle signal 6
  • the received wave having the lowest frequency is the own vehicle signal 6 reflected by the obstacle 7c.
  • the received wave corresponding to the other vehicle signal 9 is surrounded by a broken line.
  • FIG. 12 is a block diagram showing a configuration example of the shaping portion 12a according to the second embodiment.
  • the shaping unit 12a includes a detection unit 1201, a high-pass filter 1211, a time shift unit 1212, a frequency shift unit 1213, and a low-pass filter 1221.
  • the detection unit 1201 orthogonally detects the time-series data of the received wave output from the receiving circuit 11, and outputs the time-series data of the received wave that has been orthogonally detected to the high-pass filter 1211 and the low-pass filter 1221.
  • the high-pass filter 1211 cuts the low frequency region of the received wave output from the detection unit 1201 and outputs the received wave in the high frequency region to the time shift unit 1212.
  • the cutoff frequency of the high-pass filter 1211 is, for example, 48 kHz, which is between the frequency of the transmitted wave of 45 kHz and the frequency of the modified transmitted wave of 51 kHz.
  • FIG. 13 is a graph showing an example of a received wave on the high frequency side output by the high-pass filter 1211 of the second embodiment.
  • the horizontal axis of the graph is the propagation time, and the vertical axis is the frequency.
  • the own vehicle signal 6a corresponding to the shaped transmission wave of the own vehicle signal 6 and the other vehicle signal 9a on the higher frequency side than the cutoff frequency of the other vehicle signal 9 are a high-pass filter. It is output from 1211.
  • the low-pass filter 1221 cuts the high frequency region of the received wave output from the detection unit 1201 and outputs the received wave in the low frequency region to the correlation function calculation unit 13 and the extraction unit 14a.
  • the cutoff frequency of the low-pass filter 1221 is, for example, 48 kHz, which is the same as that of the high-pass filter 1211.
  • FIG. 14 is a graph showing an example of a received wave on the low frequency side output by the low-pass filter 1221 of the second embodiment. Propagation of the graph The horizontal axis is time and the vertical axis is frequency. As shown in FIG. 14, the own vehicle signal 6b corresponding to the transmitted wave of the own vehicle signal 6 and the other vehicle signal 9b on the lower frequency side than the cutoff frequency of the other vehicle signal 9 are low-pass filters. It is output from 1221.
  • the filter processing of the high-pass filter 1211 and the low-pass filter 1221 may not be necessary.
  • the high-pass filter 1211 may be configured as a band-pass filter that cuts a low-frequency region and a high-frequency region in which no signal component exists.
  • the low-pass filter 1221 may also be configured as a band-pass filter that cuts low-frequency regions and high-frequency regions in which no signal component is present.
  • the time shift unit 1212 shifts the received wave on the high frequency side from the high-pass filter 1211 by -1 ms time based on the time shift amount which is the deformation content set by the deformation content setting unit 2.
  • the time shift unit 1212 outputs the received wave on the high frequency side after the time shift to the frequency shift unit 1213.
  • the frequency shift unit 1213 shifts the received wave on the high frequency side from the time shift unit 1212 by -6 kHz frequency based on the frequency shift amount which is the deformation content set by the deformation content setting unit 2.
  • the frequency shift method may be a method of moving the input signal subjected to Fourier transform on the frequency axis, or a method of adding a linear phase shift amount to the input signal orthogonally detected. ..
  • the frequency shift unit 1213 outputs the received wave on the high frequency side after the frequency shift as a shaped reception wave to the correlation function calculation unit 13 and the extraction unit 14a.
  • FIG. 15 is a graph showing an example of a shaped received wave output by the frequency shift unit 1213 of the second embodiment.
  • the horizontal axis of the graph is the propagation time, and the vertical axis is the frequency. Since the modified content here is to shift the duplicated transmission wave by 1 ms time and shift the frequency by 6 kHz, the shaping unit 12a uses the received wave on the high frequency side in order to return the time shift and the frequency shift.
  • a shaped reception wave is generated by shifting a certain own vehicle signal 6a and another vehicle signal 9b by -1 ms time and shifting the frequency by -6 kHz.
  • the correlation function calculation unit 13 calculates the correlation function between the received wave on the low frequency side shown in FIG. 14 and the shaped received wave shown in FIG.
  • the length of the time window at the time of the correlation function calculation is 1 ms, which is the signal length of the transmitted wave output from the transmitted wave generation unit 1.
  • FIG. 16 is a graph showing an example of the correlation function output by the correlation function calculation unit 13 of the second embodiment.
  • the horizontal axis of the graph is the propagation time, and the vertical axis is the value of the correlation function.
  • the value of the correlation function increases at the reflection position of the own vehicle signal 6.
  • the correlation function calculation unit 13 calculates the correlation function between the received wave on the low frequency side and the shaped received wave, so that the other vehicle signal 9 having a low cross-correlation is removed as noise, and the source shown in FIG.
  • the signal-to-noise intensity ratio is improved compared to the received waveform of.
  • the correlation function between the received wave on the low frequency side and the shaped received wave is calculated, the value of the correlation function becomes large at the reflection position of the own vehicle signal 6 without compensating for the Doppler shift.
  • FIG. 17 is a block diagram showing a configuration example of the extraction unit 14a according to the second embodiment.
  • the extraction unit 14a includes a received power calculation unit 1401, a comparison unit 1402, and an obstacle candidate position detection unit 1411.
  • the obstacle candidate position detection unit 1411 detects a position where the absolute value of the correlation function output from the correlation function calculation unit 13 is equal to or higher than a predetermined threshold value as an obstacle candidate position, and detects the detected obstacle candidate position. Output to the comparison unit 1402.
  • FIG. 18 is a graph for explaining the processing by the obstacle candidate position detection unit 1411 of the second embodiment.
  • the horizontal axis of the graph is the propagation time, and the vertical axis is the value of the correlation function (solid line) and the received power (broken line).
  • the obstacle candidate position detection unit 1411 sets the position from 10.9 ms to 12.6 ms and the position from 14.1 ms to 14.2 ms when the value of the correlation function shown by the solid line is the threshold value TH2 or more. It is detected as candidate positions T1 and T2.
  • This threshold value TH2 is a threshold value for removing noise such as another vehicle signal 9, and is predetermined in the obstacle candidate position detection unit 1411.
  • the received power calculation unit 1401 calculates the received power using the shaped received wave (see FIG. 15) output from the shaping unit 12a and the received wave on the low frequency side (see FIG. 14). An example of the calculated received power is shown by the dashed line in FIG.
  • the received power calculation unit 1401 outputs the calculated received power to the comparison unit 1402.
  • the cross-correlation function is calculated by ⁇ x (t) y * (t), while the received power is calculated by ⁇
  • x (t) is the time series data of the well-formed reception wave
  • y (t) is the time series data of the received wave on the low frequency side.
  • y * (t) is the complex conjugate of y (t).
  • the comparison unit 1402 receives the obstacle candidate position from the obstacle candidate position detection unit 1411, the received power from the received power calculation unit 1401, and the calculation result of the correlation function from the correlation function calculation unit 13. Then, the comparison unit 1402 compares the received power at the obstacle candidate position with the absolute value of the correlation function. When the absolute value of the correlation function is equal to or greater than a predetermined ratio with respect to the received power (that is, the intensity of the received wave), the comparison unit 1402 indicates that the obstacle candidate position corresponds to the reflection position of the own vehicle signal 6. It is determined that the obstacles 7a, 7b, and 7c actually existed at the obstacle candidate positions.
  • the comparison unit 1402 does not determine the presence or absence of the obstacles 7a, 7b, 7c by the determination in one transmission cycle, and the obstacles 7a, 7b, 7c are determined based on the plurality of determinations in the plurality of transmission cycles. The certainty of presence or absence may be obtained.
  • the comparison unit 1402 outputs the determined obstacle position.
  • the magnitude relationship between the received power and the correlation function is ⁇
  • the condition for establishing the equal sign is the equation (1). .. Arg (x (t)) is the argument of x (t). That is, when the phase difference between x (t) and y (t) is a constant value at all times, the absolute value of the correlation function is the same as the received power, and the larger the phase variation, the more the absolute value of the correlation function. Becomes smaller. Therefore, the similarity between the received wave and the shaped received wave can be normalized by observing the magnitude of the correlation function with respect to the received power in the comparison unit 1402.
  • FIG. 19 is a graph for explaining the processing by the comparison unit 1402 of the second embodiment.
  • the horizontal axis of the graph is the propagation time, and the vertical axis is the ratio of the correlation function to the received power.
  • the value of 65% of the received power is used as the threshold TH3.
  • the comparison unit 1402 since the value of the correlation function with respect to the received power at the obstacle candidate position T1 is equal to or higher than the threshold value TH3, the value of the correlation function at the obstacle candidate position T1 corresponds to the reflection position of the own vehicle signal 6. It is determined that the obstacles 7a, 7b, and 7c actually existed at the obstacle candidate positions.
  • the comparison unit 1402 determines that the value of the correlation function at the obstacle candidate position T2 is noise.
  • the transmission wave deformation unit 3 of the second embodiment generates a deformation transmission wave in which both the frequency and the time of the transmission wave are shifted.
  • the transmission circuit 4 is a low-cost binary waveform drive circuit
  • the amplitude of the transmission wave is constant, so that the transmission power can be increased by shifting the time to lengthen the transmission time. That is, the transmission power can be increased by shifting both the frequency and the time rather than shifting only the frequency.
  • the obstacle detection device 16 can transmit ultrasonic waves at low cost and have a high signal-to-noise ratio.
  • the shaping unit 12a shifts both the frequency and the time of the received wave.
  • the received wave corresponding to the modified transmitted wave frequency-shifted and time-shifted by the transmitted wave deforming unit 3 is frequency-shifted and time-shifted by the shaping unit 12a to generate the shaped received wave, thereby forming the shaped received wave and the received wave.
  • the frequencies of are matched and the value of the correlation function becomes large.
  • the extraction unit 14a when the value of the correlation function is equal to or more than a predetermined ratio with respect to the intensity of the received wave, the extraction unit 14a extracts as a component corresponding to the transmitted wave. Therefore, the extraction unit 14a can exclude the received wave whose part of the waveform is similar to the shaped received wave by chance, and can extract only the received wave which is similar.
  • FIG. 20 is a block diagram showing a configuration example of the obstacle detection device 16-1 according to the third embodiment.
  • the obstacle detection device 16-1 according to the third embodiment has a configuration in which another terminal signal detection unit 18-2 is added to the obstacle detection device 16 of the second embodiment shown in FIG. 7.
  • the other terminal signal detection unit 18-2 includes a shaping unit 12a-2, a correlation function calculation unit 13-2, and an extraction unit 14a-2.
  • the shaping unit 12a-2, the correlation function calculation unit 13-2, and the extraction unit 14a-2 are the shaping unit 12a, the correlation function calculation unit 13, and the correlation function calculation unit 13 in the obstacle detection device 16 of the second embodiment shown in FIG. It is the same as the extraction unit 14a.
  • the shaping unit 12a-1, the correlation function calculation unit 13-1, and the extraction unit 14a-1 in the obstacle detection device 16-1 according to the third embodiment are the obstacles of the second embodiment shown in FIG. It is the same as the shaping unit 12a, the correlation function calculation unit 13, and the extraction unit 14a in the object detection device 16.
  • the shaping unit 12a-1, the correlation function calculation unit 13-1, and the extraction unit 14a-1 constitute the own terminal signal detection unit 18-1.
  • FIG. 20 the same or corresponding parts as those in FIGS. 1, 7, 12, and 17, are designated by the same reference numerals, and the description thereof will be omitted.
  • the obstacle detection device 16-2 Since the obstacle detection device 16-2 has the same configuration as the obstacle detection device 16-1, the description thereof will be omitted. In the following, it is assumed that the obstacle detection device 16-2 is another terminal when viewed from the obstacle detection device 16-1, and the obstacle detection device 16-1 is another terminal when viewed from the obstacle detection device 16-2. To do.
  • FIG. 21 is a diagram showing an example of obstacle arrangement in the third embodiment, and is a state in which the periphery of the own vehicle 17 is viewed from above.
  • Obstacles 7d, 7e, 7f exist in front of the own vehicle 17.
  • the ultrasonic transmission element 5 and the ultrasonic reception element 10 of the obstacle detection device 16-1 and the ultrasonic transmission element 5 and the ultrasonic reception element 10 of the obstacle detection device 16-2 are provided. Is installed.
  • the ultrasonic waves transmitted by the ultrasonic wave transmitting element 5 of the obstacle detecting device 16-1 are called own terminal signals 6-1 and the ultrasonic waves transmitted by the ultrasonic wave transmitting element 5 of the obstacle detecting device 16-2 are referred to as the own terminal signal 6-1. It is called a terminal signal 6-2.
  • the own terminal signal 6-1 transmitted from the ultrasonic transmission element 5 of the obstacle detection device 16-1 is reflected by the obstacles 7d, 7e, and 7f to become the own terminal signal echo, and the obstacle detection device 16-1 It returns to the ultrasonic receiving element 10 and the ultrasonic receiving element 10 of the obstacle detection device 16-2.
  • the other terminal signal 6-2 transmitted from the ultrasonic transmission element 5 of the obstacle detection device 16-2 is reflected by the obstacles 7d, 7e, and 7f to become another terminal signal echo, and the obstacle detection device 16 It returns to the ultrasonic receiving element 10 of -1 and the ultrasonic receiving element 10 of the obstacle detection device 16-2.
  • the ultrasonic transmission element 5 and the ultrasonic reception element 10 of the obstacle detection device 16-1 and the ultrasonic transmission element 5 and the ultrasonic reception element 10 of the obstacle detection device 16-2 Is installed so as to be offset in the left-right direction of the own vehicle 17. Therefore, for example, the distance from the obstacle detection device 16-1 to the obstacle 7d is 200 cm, while the distance from the obstacle detection device 16-2 to the obstacle 7d is 205 cm.
  • the transmission wave generation unit 1 of the obstacle detection device 16-1 outputs the signal length of the transmission wave to the correlation function calculation unit 13-1 and the extraction unit 14a-1 of the obstacle detection device 16-1.
  • the transmission wave generation unit 1 of the obstacle detection device 16-1 outputs the signal length of the transmission wave to the obstacle detection device 16-2.
  • the deformation content setting unit 2 of the obstacle detection device 16-1 outputs the deformation content to the transmission wave deformation unit 3 and the shaping unit 12a-1 of the obstacle detection device 16-1.
  • the deformation content setting unit 2 of the obstacle detection device 16-1 outputs the deformation content to the obstacle detection device 16-2.
  • the correlation function calculation unit 13-2 and the extraction unit 14a-2 of the obstacle detection device 16-1 acquire the signal length of the transmission wave output from the obstacle detection device 16-2.
  • the shaping unit 12a-1 of the obstacle detection device 16-1 acquires the deformation content output from the obstacle detection device 16-2.
  • the own terminal signal is performed by performing the same shaping, correlation function calculation, and extraction processing as in the second embodiment using the deformation content from the transformation content setting unit 2 and the signal length of the transmission wave from the transmission wave generation unit 1.
  • the reflection position of 6-1 is detected.
  • the other terminal signal detection unit 18-2 receives the received wave in which the own terminal signal 6-1 and the other terminal signal 6-2 output from the reception circuit 11 are mixed from the obstacle detection device 16-2.
  • the reflection position of the other terminal signal 6-2 is detected by performing the same shaping, correlation function calculation, and extraction processing as in the second embodiment using the modified contents of the above and the signal length of the transmitted wave.
  • the obstacle detection device 16-1 and the obstacle detection device 16-2 share information on the signal length and deformation contents necessary for shaping the signal of the other terminal, and use the information to signal the other terminal. Both signals can be identified by performing processing such as shaping in the detection unit 18-2.
  • the information on the signal length and the deformation content is shared directly between the obstacle detection devices 16-1 and 16-2, but the configuration is not limited to this.
  • a management device (not shown) manages information on the signal length and deformation content of the obstacle detection device 16-1 and information on the signal length and deformation content of the obstacle detection device 16-2, and obtains these information as obstacles. Output to object detection devices 16-1 and 16-2.
  • FIG. 22 is a graph showing an example of a transmission wave and a deformation transmission wave output by the transmission wave deformation unit 3 of the obstacle detection device 16-1 according to the third embodiment.
  • FIG. 23 is a graph showing an example of a transmission wave and a deformation transmission wave output by the transmission wave deformation unit 3 of the obstacle detection device 16-2 according to the third embodiment.
  • the horizontal axis is the time when the transmission start time of the obstacle detection device 16-1 is 0 ms
  • the vertical axis is the frequency.
  • the transmission wave and the deformation transmission wave of the obstacle detection device 16-1 and the transmission wave and the deformation transmission wave of the obstacle detection device 16-2 are different from each other. In the examples of FIGS.
  • the transmission timing of the obstacle detection device 16-1 and the transmission timing of the obstacle detection device 16-2 are different, but they may be simultaneous.
  • the transmission timings are different, the intensity of the interference wave when detecting an obstacle at a short distance can be suppressed, so that the obstacle at a short distance can be reliably detected.
  • the frequency of the transmitted wave and the modified transmission are so as to have a symmetric relationship about 48 kHz, which is the natural frequency of the ultrasonic transmitting element 5 and the ultrasonic receiving element 10.
  • the frequency of the wave is set.
  • FIG. 24 is a graph showing an example of a received wave output by the receiving circuit 11 of the obstacle detection device 16-1 according to the third embodiment.
  • the horizontal axis of the graph is the propagation time with the transmission start time of the ultrasonic wave transmitting element 5 as 0 ms, and the vertical axis is the voltage value.
  • the received wave output by the receiving circuit 11 includes the own terminal signal 6-1 and the other terminal signal 6-2.
  • the received wave having the shortest propagation time is reflected by the obstacle 7d
  • the received wave having the second shortest propagation time is reflected by the obstacle 7e.
  • the received wave with the longest propagation time is the one reflected by the obstacle 7f.
  • the received wave having the shortest propagation time is reflected by the obstacle 7d
  • the received wave having the second shortest propagation time is reflected by the obstacle 7e.
  • the received wave with the longest propagation time is the one reflected by the obstacle 7f.
  • the shaping unit 12a-1 of the own terminal signal detection unit 18-1 shapes the received wave output from the receiving circuit 11 using the modified contents of the own terminal, and shapes the received wave and the shaped received wave into a correlation function calculation unit. Output to 13-1 and extraction unit 14a-1.
  • the correlation function calculation unit 13-1 calculates the correlation function between the received wave and the shaped reception wave using the signal length of the own terminal, and outputs the calculation result to the extraction unit 14a-1.
  • the extraction unit 14a-1 calculates the received power using the received wave and the shaped reception wave, and extracts the own terminal signal 6-1 included in the received wave using the received power and the calculation result of the correlation function.
  • FIG. 25 is a graph showing an example of the value of the correlation function and the received power calculated by the local terminal signal detection unit 18-1 of the third embodiment.
  • the horizontal axis of the graph is the propagation time, and the vertical axis is the value of the correlation function (solid line) and the received power (broken line).
  • the extraction unit 14a-1 detects a position where the value of the correlation function shown in FIG. 25 is equal to or higher than the threshold value TH2 as an obstacle candidate position. Comparing the received voltage before shaping shown in FIG. 24 with the received power after shaping shown in FIG. 25, the intensity of the received wave corresponding to the other terminal signal 6-2 is reduced. Therefore, the other terminal signal 6-2 is less likely to be detected as an obstacle candidate position, and erroneous detection is suppressed.
  • FIG. 26 is a graph showing an example of the ratio of the correlation function to the received power calculated by the local terminal signal detection unit 18-1 of the third embodiment.
  • the horizontal axis of the graph is the propagation time, and the vertical axis is the ratio of the correlation function to the received power.
  • a value of 85% of the received power is used as the threshold TH3.
  • the extraction unit 14a-1 corresponds to the reflection position of the own terminal signal 6-1 and the obstacle candidate. It is determined that there are actually obstacles 7d, 7e, 7f at the position.
  • the extraction unit 14a-1 uses not only whether or not the value of the correlation function with respect to the received power is the threshold value TH3 or more, but also the duration or frequency at which the threshold value is TH3 or more, and the obstacles 7d, 7e, 7f. You may decide the presence or absence of. As shown in FIG. 26, since the value of the correlation function with respect to the received power is less than the threshold value TH3 in the portion other than the reflection position of the own terminal signal 6-1, the extraction unit 14a-1 uses the own terminal signal 6-1. And the other terminal signal 6-2 can be correctly distinguished.
  • the other terminal signal detection unit 18-2 also processes the reception wave output from the reception circuit 11 to obtain the own terminal signal 6-1 included in the reception wave. Distinguish from other terminal signal 6-2.
  • FIG. 27 is a graph showing an example of the value of the correlation function and the received power calculated by the other terminal signal detection unit 18-2 of the third embodiment.
  • the horizontal axis of the graph is the propagation time, and the vertical axis is the value of the correlation function (solid line) and the received power (broken line).
  • the extraction unit 14a-2 detects a position where the value of the correlation function shown in FIG. 27 is the threshold value TH2 or more as an obstacle candidate position. Comparing the received voltage before shaping shown in FIG. 24 with the received power after shaping shown in FIG. 27, the intensity of the received wave corresponding to the own terminal signal 6-1 is reduced. Therefore, the own terminal signal 6-1 is less likely to be detected as an obstacle candidate position, and erroneous detection is suppressed.
  • FIG. 28 is a graph showing an example of the ratio of the correlation function to the received power calculated by the other terminal signal detection unit 18-2 of the third embodiment.
  • the horizontal axis of the graph is the propagation time, and the vertical axis is the ratio of the correlation function to the received power.
  • the extraction unit 14a-2 corresponds to the reflection position of the other terminal signal 6-2
  • the obstacle candidate position corresponds to the reflection position of the other terminal signal 6-2. It is determined that there are actually obstacles 7d, 7e, 7f at the position. As shown in FIG.
  • the extraction unit 14a-2 since the value of the correlation function with respect to the received power is less than the threshold value TH3 in the portion other than the reflection position of the other terminal signal 6-2, the extraction unit 14a-2 uses the own terminal signal 6-1. And the other terminal signal 6-2 can be correctly distinguished.
  • the reflection position of the own terminal signal 6-1 output by the extraction unit 14a-1 and the reflection position of the other terminal signal 6-2 output by the extraction unit 14a-2 are, for example, an ECU (Electronic Control Unit) that automatically parks. It is used for aperture synthesis processing or two-circle intersection processing. The two-dimensional coordinate position of the obstacle is calculated by the aperture synthesis process or the two-circle intersection process.
  • ECU Electronic Control Unit
  • the obstacle detection devices 16-1 and 16-2 have one set of the transmitted wave and the modified transmitted wave, and two sets of the transmitted wave and the modified transmitted wave having different waveforms. Output.
  • the obstacle detection devices 16-1 and 16-2 receive the own terminal signal 6-1 and the other terminal signal 6-2 from the received wave in which the own terminal signal 6-1 and the other terminal signal 6-2 interfere with each other. And can be extracted. Therefore, the obstacle detection devices 16-1 and 16-2 can multiplex the own terminal signal 6-1 and the other terminal signal 6-2, and can shorten the transmission cycle.
  • the obstacle detection device 16-1 transmits one set of transmission waves and the modified transmission wave
  • the obstacle detection device 16-2 transmits another set of transmission waves having different waveforms and deformation transmission.
  • the obstacle detection device 16-1 includes two transmission / reception units 15, one transmission / reception unit 15 transmits the transmission wave and the modified transmission wave shown in FIG. 22 as the own terminal signal 6-1 and the other transmission / reception unit 15.
  • the transmission / reception unit 15 may be configured to transmit the transmission wave and the modified transmission wave shown in FIG. 23 as another terminal signal 6-2.
  • the deformation content setting unit 2 holds two types of deformation contents
  • the transmission wave deformation unit 3 generates the deformation transmission wave shown in FIG.
  • the deformed transmission wave shown in FIG. 23 is generated based on one of the deformed contents.
  • the own terminal signal detection unit 18-1 processes the received wave from one transmission / reception unit 15, and the other terminal signal detection unit 18-2 processes the reception wave from the other transmission / reception unit 15. Even in this configuration, the obstacle detection device 16-1 uses the received wave in which the own terminal signal 6-1 and the other terminal signal 6-2 interfere with each other to generate the own terminal signal 6-1 and the other terminal signal 6-2. And can be extracted, and the transmission cycle can be shortened.
  • the frequency of the transmitted wave and the frequency of the modified transmitted wave have a symmetrical relationship with respect to the natural frequency of the ultrasonic transmitting element 5. Since the obstacle detection devices 16-1 and 16-2 can use the frequency region having the highest sensitivity of the ultrasonic wave transmitting element 5, it is possible to transmit ultrasonic waves having a high signal-to-noise ratio.
  • the frequency of the transmitted wave and the frequency of the modified transmitted wave may have a symmetrical relationship with respect to the frequency shifted from the natural frequency of the ultrasonic transmitting element 5.
  • the natural frequency of the ultrasonic transmitting element 5 of the ultrasonic transmitting element 5 is 48 kHz
  • the transmitted wave of 42 kHz and the deformation of 48 kHz are symmetrical with respect to 45 kHz shifted by -3 kHz from this natural frequency.
  • a transmitted wave is generated.
  • Obstacle detection devices 16-1 and 16-2 can suppress the influence of the signal component generated by the reverberation of the ultrasonic transmitting element 5 on the received wave by using a frequency away from the natural frequency. it can.
  • Embodiment 4 an example in which the waveform of the other terminal signal 6-2 in the third embodiment is changed will be described. Since the configurations of the obstacle detection devices 16-1 and 16-2 according to the fourth embodiment are the same as the configurations shown in FIG. 20 of the third embodiment on the drawing, FIG. 20 is incorporated below. To do. Further, as an example of obstacle placement in the fourth embodiment, FIG. 21 of the third embodiment is incorporated.
  • FIG. 29 is a graph showing an example of a transmission wave and a deformation transmission wave output by the transmission wave deformation unit 3 of the obstacle detection device 16-1 according to the fourth embodiment.
  • FIG. 30 is a graph showing an example of a transmission wave and a deformation transmission wave output by the transmission wave deformation unit 3 of the obstacle detection device 16-2 according to the fourth embodiment.
  • the horizontal axis is the time when the transmission start time of the obstacle detection device 16-1 is 0 ms
  • the vertical axis is the frequency.
  • the modified transmitted wave is shifted by 1 ms time, there is a 1 ms pause section between the transmitted wave and the modified transmitted wave.
  • FIG. 31 is a graph showing an example of a received wave output by the receiving circuit 11 of the obstacle detection device 16-1 according to the fourth embodiment.
  • the horizontal axis of the graph is the propagation time with the transmission start time of the ultrasonic wave transmitting element 5 as 0 ms, and the vertical axis is the voltage value.
  • the received wave output by the receiving circuit 11 includes the own terminal signal 6-1 and the other terminal signal 6-2.
  • the received wave having the shortest propagation time is reflected by the obstacle 7d
  • the received wave having the second shortest propagation time is reflected by the obstacle 7e.
  • the received wave with the longest propagation time is the one reflected by the obstacle 7f.
  • the received wave having the shortest propagation time is reflected by the obstacle 7d
  • the received wave having the second shortest propagation time is reflected by the obstacle 7e.
  • the received wave with the longest propagation time is the one reflected by the obstacle 7f.
  • a pause section of 1 ms appears in the received wave corresponding to the other terminal signal 6-2.
  • FIG. 32 is a graph showing an example of the value of the correlation function and the received power calculated by the local terminal signal detection unit 18-1 of the fourth embodiment.
  • the horizontal axis of the graph is the propagation time, and the vertical axis is the value of the correlation function (solid line) and the received power (broken line). Comparing the received voltage before shaping shown in FIG. 31 with the received power after shaping shown in FIG. 32, the intensity of the received wave corresponding to the other terminal signal 6-2 is reduced. Therefore, the other terminal signal 6-2 is less likely to be detected as an obstacle candidate position, and erroneous detection is suppressed.
  • FIG. 33 is a graph showing an example of the ratio of the correlation function to the received power calculated by the local terminal signal detection unit 18-1 of the fourth embodiment.
  • the horizontal axis of the graph is the propagation time, and the vertical axis is the ratio of the correlation function to the received power.
  • the extraction unit 14a-1 uses the own terminal signal 6-1. And the other terminal signal 6-2 can be correctly distinguished.
  • FIG. 34 is a graph showing an example of the value of the correlation function and the received power calculated by the other terminal signal detection unit 18-2 of the fourth embodiment.
  • the horizontal axis of the graph is the propagation time, and the vertical axis is the value of the correlation function (solid line) and the received power (broken line).
  • FIG. 35 is a graph showing an example of the ratio of the correlation function to the received power calculated by the other terminal signal detection unit 18-2 of the fourth embodiment.
  • the horizontal axis of the graph is the propagation time, and the vertical axis is the ratio of the correlation function to the received power.
  • the extraction unit 14a-2 uses the own terminal signal 6-1. And the other terminal signal 6-2 can be correctly distinguished.
  • one set of the two sets of transmitted waves and the modified transmitted wave (that is, the other terminal signal 6-2) is paused between the transmitted wave and the modified transmitted wave.
  • the pause section is set to 1 ms, but by using a plurality of sets of the transmission wave and the modified transmission wave in which the pause section is changed, more ultrasonic waves can be multiplexed. It will be possible.
  • the ultrasonic transmitting element 5 has a transmitted wave shorter than this transmitted wave (hereinafter, "short distance"). (Called a search wave) is transmitted.
  • the short-range search wave is, for example, a short pulse of one wave.
  • Piezoelectric ceramics which are widely used in vehicles, have a slow speed at which the sound pressure follows the applied voltage. Therefore, when transmitting ultrasonic waves of different frequencies, the sound pressure follows the sound pressure when the frequency is changed by 10 to 25. It takes about the time of a wave. That is, it takes about 10 to 25 waves for the amplitude of the ultrasonic wave transmitted from the ultrasonic wave transmitting element 5 to be maximized. Further, when receiving ultrasonic waves, it takes about 10 to 25 waves for the voltage output from the ultrasonic wave receiving element 10 to follow the applied sound pressure. Therefore, the own vehicle signal 6 requires about 20 to 50 waves.
  • the own vehicle signal 6 shown in FIG. 3A is composed of 24 transmitted waves and 24 modified transmitted waves, for a total of 48 waves.
  • the ultrasonic element when one ultrasonic element also serves as the ultrasonic transmitting element 5 and the ultrasonic receiving element 10, the ultrasonic element echoes the own vehicle signal while transmitting the own vehicle signal 6 of 20 to 50 waves. 8 cannot be received. Therefore, it becomes difficult for the obstacle detection device 16 to detect the obstacle 7 existing at a short distance with a short propagation time. Therefore, the obstacle detection device 16 according to the fifth embodiment transmits a short-distance search wave in addition to the transmission wave and the modified transmission wave to enable detection of the obstacle 7 existing at a short distance.
  • FIG. 36 is a block diagram showing a configuration example of the obstacle detection device 16 according to the fifth embodiment.
  • the obstacle detecting device 16 according to the fifth embodiment replaces the ultrasonic transmitting element 5 and the ultrasonic receiving element 10 in the obstacle detecting device 16 of the first embodiment shown in FIG. 1, and the ultrasonic element 19 is used. It is a configuration including.
  • FIG. 36 the same or corresponding parts as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.
  • the transmission wave generation unit 1b generates a short-range search wave such as a short pulse of one wave, and outputs the generated short-range search wave to the transmission circuit 4b.
  • the transmission circuit 4b converts the short-range search wave into a voltage that can be applied to the ultrasonic element 19, and the ultrasonic element 19 transmits and receives the short-range search wave. For example, the ultrasonic element 19 first transmits a short-range search wave, and 5 ms later, transmits a transmission wave and a modified transmission wave.
  • the receiving circuit 11b outputs the received wave that has received the short-range search wave to the extraction unit 14b.
  • the extraction unit 14b extracts the short-range search wave included in the received wave and outputs the propagation time of the extracted short-range search wave. For example, the extraction unit 14b compares a predetermined threshold value with the intensity of the received wave, and extracts as a short-distance search wave when the intensity of the received wave is equal to or higher than the threshold value.
  • the obstacle detection device 16 does not perform the shaping process by the shaping unit 12 and the correlation function calculation processing by the correlation function calculation unit 13 for the short-distance search wave.
  • the ultrasonic element 19 transmits a short-range search wave shorter than this transmitted wave in addition to the transmitted wave and the deformed transmitted wave.
  • the obstacle detection device 16 can detect a long-distance obstacle using a transmitted wave and a modified transmitted wave, and can detect a short-distance obstacle using a short-distance search wave.
  • the function of transmitting a short-range search wave is applied to an obstacle detection device 16 provided with one ultrasonic element 19 for transmission / reception, but the ultrasonic transmission element It may be applied to the obstacle detection device 16 including the 5 and the ultrasonic wave receiving element 10.
  • the function of transmitting the short-distance search wave is applied to the obstacle detection device 16 according to the first embodiment is shown, but this function is applied to the obstacle detection device 16 according to the second embodiment. It may be applied to the detection device 16 and the obstacle detection devices 16-1 and 16-2 according to the third and fourth embodiments.
  • FIG. 37 and 38 are diagrams showing a hardware configuration example of the obstacle detection devices 16, 16-1, 16-2 according to each embodiment.
  • the functions of the arithmetic units 13, 13-1, 13-2 and the extraction units 14, 14a, 14a-1, 14a-2, 14b are realized by the processing circuit. That is, the obstacle detection devices 16, 16-1, 16-2 are provided with a processing circuit for realizing the above functions.
  • the processing circuit may be a processing circuit 100 as dedicated hardware, or a processor 101 that executes a program stored in the memory 102.
  • the processing circuit 100 may be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, or an ASIC (Application Special Integrated Circuit). ), FPGA (Field Processor Gate Array), or a combination thereof.
  • the functions of 14, 14a, 14a-1, 14a-2, and 14b may be realized by a plurality of processing circuits 100, or the functions of each part may be collectively realized by one processing circuit 100.
  • the processing circuit is the processor 101
  • Correlation function calculation unit 13, 13-1, 13-2, extraction unit 14, 14a, 14a-1, 14a-2, 14b functions are realized by software, firmware, or a combination of software and firmware.
  • the software or firmware is described as a program and stored in the memory 102.
  • the processor 101 realizes the functions of each part by reading and executing the program stored in the memory 102. That is, the obstacle detection devices 16, 16-1, 16-2 store a program in which the operations described in the first to fifth embodiments are eventually executed when executed by the processor 101.
  • a memory 102 is provided.
  • this program includes a transmission wave generation unit 1, 1b, a transformation content setting unit 2, a transmission wave deformation unit 3, a shaping unit 12, 12a, 12a-1, 12a-2, a correlation function calculation unit 13, 13-1, It can also be said that the procedure or method of 13-2, extraction units 14, 14a, 14a-1, 14a-2, 14b is executed by a computer.
  • the processor 101 is a CPU (Central Processing Unit), a processing device, an arithmetic unit, a microprocessor, or the like.
  • the memory 102 may be a non-volatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), an EPROM (Erasable Programmable ROM), or a flash memory, or may be a non-volatile or volatile semiconductor memory such as a hard disk or a flexible disk. It may be a magnetic disk of the above, or an optical disk such as a CD (Compact Disc) or a DVD (Digital Versaille Disc).
  • Some of the functions of the extraction units 14, 14a, 14a-1, 14a-2, and 14b may be realized by dedicated hardware, and some may be realized by software or firmware.
  • the processing circuits in the obstacle detection devices 16, 16-1, 16-2 can realize the above-mentioned functions by hardware, software, firmware, or a combination thereof.
  • the present invention allows any combination of embodiments, modifications of any component of each embodiment, or omission of any component of each embodiment within the scope of the invention.
  • the obstacle detection device Since the obstacle detection device according to the present invention is designed to identify a plurality of ultrasonic signals, it is suitable for an obstacle detection device used in an operation control device or the like that automatically parks and drives a vehicle.

Abstract

A transmission wave deformation unit (3) generates a deformed transmission wave obtained by dividing or reproducing, and deforming, a transmission wave generated by a transmission wave generating unit (1). A transmission/reception unit (15) transmits a transmission wave and the deformed transmission wave as a host vehicle signal (6), receives a host signal echo (8) reflected by an obstacle (7), and outputs a reception wave. A shaping unit (12) generates a shaped reception wave obtained by shaping the reception wave on the basis of the content of deformation by the transmission wave deformation unit (3). A correlation function computation unit (13) computes a correlation function of the reception wave and the shaped reception wave. An extraction unit (14) extracts a component corresponding to the host vehicle signal (6) from the reception wave on the basis of the correlation function computed by the correlation function computation unit (13).

Description

障害物検出装置Obstacle detector
　この発明は、超音波を用いて障害物を検出する障害物検出装置に関するものである。 The present invention relates to an obstacle detection device that detects an obstacle using ultrasonic waves.
　超音波は、気体又は液体の媒体中を伝播するので、障害物検出装置は、障害物に向かって超音波を送信し、障害物において反射した超音波を受信することにより、超音波の伝播時間を求めることができる。媒体における超音波の伝播速度は一定であるので、障害物までの距離は、伝播時間に伝播速度を乗じて求まる超音波の伝播距離の１／２として算出される。 Since ultrasonic waves propagate in a gas or liquid medium, the obstacle detector transmits the ultrasonic waves toward the obstacle and receives the ultrasonic waves reflected by the obstacle, so that the propagation time of the ultrasonic waves is long. Can be sought. Since the propagation speed of ultrasonic waves in the medium is constant, the distance to the obstacle is calculated as 1/2 of the propagation distance of ultrasonic waves obtained by multiplying the propagation time by the propagation speed.
　この障害物検出装置は、車両の自動駐車等への適用が検討されているが、自車両が送信した超音波信号と他車両が送信した超音波信号との混信が課題とされている。この課題を解決するために、相互相関の低い擬似ランダム系列に基づいた超音波信号を送信することによって、複数の超音波信号を識別する方法が提案されている（例えば、特許文献１参照）。 This obstacle detection device is being considered for application to automatic parking of vehicles, etc., but interference between the ultrasonic signal transmitted by the own vehicle and the ultrasonic signal transmitted by another vehicle is an issue. In order to solve this problem, a method of identifying a plurality of ultrasonic signals by transmitting ultrasonic signals based on a pseudo-random sequence having low cross-correlation has been proposed (see, for example, Patent Document 1).
特許第５９３７２９４号公報Japanese Patent No. 5937294
　従来の障害物検出装置では、送信した上記擬似ランダム系列に基づいた超音波信号が、異なるドップラシフトを受けて時間的に重複して戻ってきた場合、ドップラシフトの除去が困難であり、受信した超音波信号の復号ができない。そのため、従来の障害物検出装置は、複数の超音波信号を識別するために、ドップラシフトのような伝播路における信号変形を補償する必要があった。 In the conventional obstacle detection device, when the transmitted ultrasonic signal based on the pseudo-random sequence receives different Doppler shifts and returns in duplicate in time, it is difficult to remove the Doppler shift and the ultrasonic signal is received. The ultrasonic signal cannot be decoded. Therefore, the conventional obstacle detection device needs to compensate for the signal deformation in the propagation path such as the Doppler shift in order to identify a plurality of ultrasonic signals.
　この発明は、上記のような課題を解決するためになされたもので、伝播路における信号変形を補償することなく複数の超音波信号を識別することを目的とする。 The present invention has been made to solve the above problems, and an object of the present invention is to identify a plurality of ultrasonic signals without compensating for signal deformation in the propagation path.
　この発明に係る障害物検出装置は、送信波を生成する送信波生成部と、送信波を分割又は複製し変形した変形送信波を生成する送信波変形部と、超音波素子を有し、送信波と変形送信波とを超音波として送信し、障害物で反射した超音波を受信して受信波を出力する送受信部と、送信波変形部の変形内容に基づいて受信波を整形した整形受信波を生成する整形部と、受信波と整形受信波との相関関数を演算する相関関数演算部と、相関関数演算部により演算された相関関数に基づいて、受信波の中から送信波に相当する成分を抽出する抽出部とを備えるものである。 The obstacle detection device according to the present invention has a transmission wave generation unit that generates a transmission wave, a transmission wave deformation unit that divides or duplicates the transmission wave to generate a deformed transmission wave, and an ultrasonic element, and transmits. A transmitter / receiver that transmits waves and deformed transmitted waves as ultrasonic waves, receives ultrasonic waves reflected by obstacles and outputs received waves, and shaped reception that shapes the received waves based on the deformed contents of the transmitted wave deformed section. Corresponds to the transmitted wave from among the received waves based on the shaping unit that generates the wave, the correlation function calculation unit that calculates the correlation function between the received wave and the shaped reception wave, and the correlation function calculated by the correlation function calculation unit. It is provided with an extraction unit for extracting the components to be used.
　この発明によれば、伝播路における信号変形を受けた受信波と整形受信波との相関関数を演算するようにしたので、信号変形を補償せずとも自己の超音波の反射位置で相関関数の値が大きくなるため、複数の超音波信号を識別することができる。 According to the present invention, since the correlation function between the received wave subjected to the signal deformation in the propagation path and the shaped received wave is calculated, the correlation function is calculated at the reflection position of the own ultrasonic wave without compensating for the signal deformation. Since the value is large, a plurality of ultrasonic signals can be identified.
実施の形態１に係る障害物検出装置１６の構成例を示すブロック図である。It is a block diagram which shows the structural example of the obstacle detection apparatus 16 which concerns on Embodiment 1. FIG. 実施の形態１の送信波生成部１が出力する送信波の例を示すグラフである。It is a graph which shows the example of the transmission wave output by the transmission wave generation unit 1 of Embodiment 1. FIG. 図３Ａ、図３Ｂ、図３Ｃ、及び図３Ｄは、実施の形態１の送信波変形部３が出力する送信波と変形送信波の例を示すグラフである。3A, 3B, 3C, and 3D are graphs showing an example of a transmission wave and a deformation transmission wave output by the transmission wave deformation unit 3 of the first embodiment. 実施の形態１の受信回路１１が出力する受信波の例を示すグラフである。It is a graph which shows the example of the received wave output by the receiving circuit 11 of Embodiment 1. FIG. 実施の形態１の整形部１２が出力する整形受信波の例を示すグラフである。It is a graph which shows the example of the shaping received wave output by the shaping section 12 of Embodiment 1. FIG. 実施の形態１の相関関数演算部１３が出力する相関関数の例を示すグラフである。6 is a graph showing an example of a correlation function output by the correlation function calculation unit 13 of the first embodiment. 実施の形態２に係る障害物検出装置１６の構成例を示すブロック図である。It is a block diagram which shows the structural example of the obstacle detection apparatus 16 which concerns on Embodiment 2. FIG. 実施の形態２の送信波変形部３が出力する送信波と変形送信波の例を示すグラフである。It is a graph which shows the example of the transmission wave and the transformation transmission wave output by the transmission wave transformation part 3 of Embodiment 2. 実施の形態２における障害物配置例を示す図であり、駐車場を上から見た状態である。It is a figure which shows the obstacle arrangement example in Embodiment 2, and is the state which the parking lot is seen from the top. 実施の形態２の受信回路１１が出力する受信波の例を示すグラフである。It is a graph which shows the example of the received wave output by the receiving circuit 11 of Embodiment 2. 実施の形態２の受信回路１１が出力する受信波の例を示すグラフである。It is a graph which shows the example of the received wave output by the receiving circuit 11 of Embodiment 2. 実施の形態２における整形部１２ａの構成例を示すブロック図である。It is a block diagram which shows the structural example of the shaping part 12a in Embodiment 2. 実施の形態２のハイパスフィルタ１２１１が出力する高周波側の受信波の例を示すグラフである。It is a graph which shows the example of the received wave on the high frequency side output by the high-pass filter 1211 of Embodiment 2. 実施の形態２のローパスフィルタ１２２１が出力する低周波側の受信波の例を示すグラフである。It is a graph which shows the example of the received wave on the low frequency side output by the low-pass filter 1221 of Embodiment 2. 実施の形態２の周波数シフト部１２１３が出力する整形受信波の例を示すグラフである。It is a graph which shows the example of the shaped received wave output by the frequency shift part 1213 of Embodiment 2. 実施の形態２の相関関数演算部１３が出力する相関関数の例を示すグラフである。6 is a graph showing an example of a correlation function output by the correlation function calculation unit 13 of the second embodiment. 実施の形態２における抽出部１４ａの構成例を示すブロック図である。It is a block diagram which shows the structural example of the extraction part 14a in Embodiment 2. 実施の形態２の障害物候補位置検出部１４１１による処理を説明するためのグラフである。It is a graph for demonstrating the process by the obstacle candidate position detection unit 1411 of Embodiment 2. 実施の形態２の比較部１４０２による処理を説明するためのグラフである。It is a graph for demonstrating the process by the comparison part 1402 of Embodiment 2. 実施の形態３に係る障害物検出装置１６－１の構成例を示すブロック図である。It is a block diagram which shows the structural example of the obstacle detection apparatus 16-1 which concerns on Embodiment 3. 実施の形態３における障害物配置例を示す図であり、自車１７の周辺を上から見た状態である。It is a figure which shows the obstacle arrangement example in Embodiment 3, and is the state which looked at the periphery of own vehicle 17 from above. 実施の形態３に係る障害物検出装置１６－１の送信波変形部３が出力する送信波と変形送信波の例を示すグラフである。It is a graph which shows the example of the transmission wave and the deformation transmission wave which the transmission wave deformation part 3 of the obstacle detection apparatus 16-1 which concerns on Embodiment 3 output. 実施の形態３に係る障害物検出装置１６－２の送信波変形部３が出力する送信波と変形送信波の例を示すグラフである。It is a graph which shows the example of the transmission wave and the deformation transmission wave which the transmission wave deformation part 3 of the obstacle detection apparatus 16-2 which concerns on Embodiment 3 output. 実施の形態３に係る障害物検出装置１６－１の受信回路１１が出力する受信波の例を示すグラフである。It is a graph which shows the example of the received wave output by the receiving circuit 11 of the obstacle detection apparatus 16-1 which concerns on Embodiment 3. FIG. 実施の形態３の自端末信号検出部１８－１において計算される相関関数の値と受信電力の例を示すグラフである。It is a graph which shows the example of the value of the correlation function and the received power calculated by the local terminal signal detection unit 18-1 of Embodiment 3. 実施の形態３の自端末信号検出部１８－１において計算される受信電力に対する相関関数の割合の例を示すグラフである。It is a graph which shows the example of the ratio of the correlation function with respect to the received power calculated by the local terminal signal detection unit 18-1 of Embodiment 3. 実施の形態３の他端末信号検出部１８－２において計算される相関関数の値と受信電力の例を示すグラフである。It is a graph which shows the example of the value of the correlation function and the received power calculated by the other terminal signal detection unit 18-2 of Embodiment 3. 実施の形態３の他端末信号検出部１８－２において計算される受信電力に対する相関関数の割合の例を示すグラフである。It is a graph which shows the example of the ratio of the correlation function with respect to the received power calculated by the other terminal signal detection unit 18-2 of Embodiment 3. 実施の形態４に係る障害物検出装置１６－１の送信波変形部３が出力する送信波と変形送信波の例を示すグラフである。It is a graph which shows the example of the transmission wave and the deformation transmission wave which the transmission wave deformation part 3 of the obstacle detection apparatus 16-1 which concerns on Embodiment 4 output. 実施の形態４に係る障害物検出装置１６－２の送信波変形部３が出力する送信波と変形送信波の例を示すグラフである。It is a graph which shows the example of the transmission wave and the deformation transmission wave which the transmission wave deformation part 3 of the obstacle detection apparatus 16-2 which concerns on Embodiment 4 output. 実施の形態４に係る障害物検出装置１６－１の受信回路１１が出力する受信波の例を示すグラフである。It is a graph which shows the example of the received wave output by the receiving circuit 11 of the obstacle detection apparatus 16-1 which concerns on Embodiment 4. FIG. 実施の形態４の自端末信号検出部１８－１において計算される相関関数の値と受信電力の例を示すグラフである。It is a graph which shows the example of the value of the correlation function and the received power calculated by the local terminal signal detection unit 18-1 of Embodiment 4. 実施の形態４の自端末信号検出部１８－１において計算される受信電力に対する相関関数の割合の例を示すグラフである。It is a graph which shows the example of the ratio of the correlation function with respect to the received power calculated by the local terminal signal detection unit 18-1 of Embodiment 4. 実施の形態４の他端末信号検出部１８－２において計算される相関関数の値と受信電力の例を示すグラフである。It is a graph which shows the example of the value of the correlation function and the received power calculated by the other terminal signal detection unit 18-2 of Embodiment 4. 実施の形態４の他端末信号検出部１８－２において計算される受信電力に対する相関関数の割合の例を示すグラフである。It is a graph which shows the example of the ratio of the correlation function with respect to the received power calculated by the other terminal signal detection unit 18-2 of Embodiment 4. 実施の形態５に係る障害物検出装置１６の構成例を示すブロック図である。It is a block diagram which shows the structural example of the obstacle detection apparatus 16 which concerns on Embodiment 5. 各実施の形態に係る障害物検出装置１６，１６－１，１６－２のハードウェア構成の一例を示す図である。It is a figure which shows an example of the hardware configuration of the obstacle detection apparatus 16, 16-1, 16-2 which concerns on each embodiment. 各実施の形態に係る障害物検出装置１６，１６－１，１６－２のハードウェア構成の別の例を示す図である。It is a figure which shows another example of the hardware composition of the obstacle detection apparatus 16, 16-1, 16-2 which concerns on each embodiment.
　以下、この発明をより詳細に説明するために、この発明を実施するための形態について、添付の図面に従って説明する。
実施の形態１．
　図１は、実施の形態１に係る障害物検出装置１６の構成例を示すブロック図である。障害物検出装置１６は、車両に搭載され、この車両周辺に存在する障害物７を検出するものである。ここでは、障害物検出装置１６が搭載された車両を「自車」と呼ぶ。障害物検出装置１６は、送信波生成部１、変形内容設定部２、送信波変形部３、送受信部１５、整形部１２、相関関数演算部１３、及び抽出部１４を備える。送受信部１５は、送信回路４、超音波送信素子５、超音波受信素子１０、及び受信回路１１を備える。 Hereinafter, in order to explain the present invention in more detail, a mode for carrying out the present invention will be described with reference to the accompanying drawings.
Embodiment 1.
FIG. 1 is a block diagram showing a configuration example of the obstacle detection device 16 according to the first embodiment. The obstacle detection device 16 is mounted on a vehicle and detects obstacles 7 existing around the vehicle. Here, the vehicle equipped with the obstacle detection device 16 is referred to as "own vehicle". The obstacle detection device 16 includes a transmission wave generation unit 1, a deformation content setting unit 2, a transmission wave deformation unit 3, a transmission / reception unit 15, a shaping unit 12, a correlation function calculation unit 13, and an extraction unit 14. The transmission / reception unit 15 includes a transmission circuit 4, an ultrasonic transmission element 5, an ultrasonic reception element 10, and a reception circuit 11.
　送信波生成部１は、送信波を生成して送信波変形部３へ出力する。また、送信波生成部１は、生成した送信波の信号長を相関関数演算部１３へ出力する。送信波生成部１が生成する送信波は、バースト波等である。この送信波は、振幅、位相、又は周波数のうちの少なくとも１つが変調されていてもよい。 The transmission wave generation unit 1 generates a transmission wave and outputs it to the transmission wave deformation unit 3. Further, the transmission wave generation unit 1 outputs the signal length of the generated transmission wave to the correlation function calculation unit 13. The transmitted wave generated by the transmitted wave generation unit 1 is a burst wave or the like. The transmitted wave may be modulated at least one of amplitude, phase, or frequency.
　変形内容設定部２は、送信波生成部１で生成された送信波の変形内容を保持しており、この変形内容を送信波変形部３及び整形部１２に対して設定する。変形内容は、時間シフト、位相シフト、又は周波数シフトのうちの少なくとも１つを含む。なお、送信波変形部３及び整形部１２が変形内容を予め保持している場合、変形内容設定部２は不要である。 The deformation content setting unit 2 holds the deformation content of the transmission wave generated by the transmission wave generation unit 1, and sets this deformation content for the transmission wave deformation unit 3 and the shaping unit 12. The modification includes at least one of a time shift, a phase shift, or a frequency shift. When the transmission wave deformation unit 3 and the shaping unit 12 hold the deformation content in advance, the deformation content setting unit 2 is unnecessary.
　送信波変形部３は、送信波生成部１で生成された送信波を分割又は複製し、分割した送信波の一方又は複製した送信波を、変形内容設定部２で設定された変形内容に基づいて変形する。送信波変形部３は、送信波と、変形した送信波（以下、「変形送信波」と称する）とを、送信回路４へ出力する。なお、変形内容設定部２で設定された変形内容に、送信波を分割するか複製するかの指示が含まれていてもよい。 The transmission wave deformation unit 3 divides or duplicates the transmission wave generated by the transmission wave generation unit 1, and one of the divided transmission waves or the duplicated transmission wave is based on the deformation content set by the transformation content setting unit 2. Transforms. The transmission wave deformation unit 3 outputs the transmission wave and the deformed transmission wave (hereinafter, referred to as “deformed transmission wave”) to the transmission circuit 4. The transformation content set by the transformation content setting unit 2 may include an instruction as to whether to divide or duplicate the transmitted wave.
　送信回路４は、送信波変形部３からの送信波と変形送信波とを、超音波送信素子５に印加できる電圧へと変換する。送信回路４は、例えば、２値波形の電圧を生成する駆動回路である。 The transmission circuit 4 converts the transmission wave from the transmission wave deformation unit 3 and the deformation transmission wave into a voltage that can be applied to the ultrasonic transmission element 5. The transmission circuit 4 is, for example, a drive circuit that generates a voltage having a binary waveform.
　超音波送信素子５は、送信回路４から印加された電圧を超音波に変換し、空間へ送信する。ここでは、自車の超音波送信素子５から送信された超音波を、自車信号６と呼ぶ。また、空間を伝播していく自車信号６が障害物７に反射したものを、自車信号エコー８と呼ぶ。また、図示しない他車から送信された超音波を、他車信号９と呼ぶ。 The ultrasonic transmission element 5 converts the voltage applied from the transmission circuit 4 into ultrasonic waves and transmits them to space. Here, the ultrasonic waves transmitted from the ultrasonic wave transmitting element 5 of the own vehicle are referred to as the own vehicle signal 6. Further, what the own vehicle signal 6 propagating in space is reflected by the obstacle 7 is called the own vehicle signal echo 8. Further, ultrasonic waves transmitted from another vehicle (not shown) are referred to as another vehicle signal 9.
　超音波受信素子１０は、自車信号エコー８及び他車信号９等の超音波により印加された圧力を、電圧に変換して受信回路１１へ出力する。 The ultrasonic receiving element 10 converts the pressure applied by ultrasonic waves such as the own vehicle signal echo 8 and the other vehicle signal 9 into a voltage and outputs it to the receiving circuit 11.
　超音波送信素子５及び超音波受信素子１０は、例えば、車載用に広く使われている圧電セラミックスである。なお、図１の障害物検出装置１６は、超音波の送受信に異なる超音波素子を用いているが、１つの超音波素子を送信と受信の両方に用いてもよい。その場合、例えば、１つの超音波素子が送信と受信とを交互に行う。 The ultrasonic transmitting element 5 and the ultrasonic receiving element 10 are, for example, piezoelectric ceramics widely used for automobiles. Although the obstacle detection device 16 in FIG. 1 uses different ultrasonic elements for transmitting and receiving ultrasonic waves, one ultrasonic element may be used for both transmission and reception. In that case, for example, one ultrasonic element alternately transmits and receives.
　受信回路１１は、超音波受信素子１０から出力された電圧を増幅し、増幅した電圧をサンプリングしてデジタルデータに変換し、変換したデジタルデータを受信波として整形部１２へ出力する。なお、受信回路１１は、物理的なフィルタを用いて、電圧をサンプリングする前にノイズを除去してもよい。 The receiving circuit 11 amplifies the voltage output from the ultrasonic receiving element 10, samples the amplified voltage, converts it into digital data, and outputs the converted digital data as a receiving wave to the shaping unit 12. Note that the receiving circuit 11 may use a physical filter to remove noise before sampling the voltage.
　整形部１２は、変形内容設定部２で設定された変形内容に基づいて、受信波と整形後の受信波との類似性が判断できるように、受信回路１１から出力された受信波を整形する。整形部１２は、受信波と、整形した受信波（以下、「整形受信波」と称する）とを、相関関数演算部１３へ出力する。 The shaping unit 12 shapes the received wave output from the receiving circuit 11 so that the similarity between the received wave and the received wave after shaping can be determined based on the deformation content set by the deformation content setting unit 2. .. The shaping unit 12 outputs the received wave and the shaped received wave (hereinafter, referred to as “shaped received wave”) to the correlation function calculation unit 13.
　相関関数演算部１３は、整形部１２からの受信波と整形受信波との相互相関関数を演算し、演算結果である時系列データを抽出部１４へ出力する。なお、相関関数演算部１３は、送信波生成部１から出力された送信波の信号長を用いて、相関関数演算時の時間窓の長さを設定する。 The correlation function calculation unit 13 calculates a cross-correlation function between the received wave from the shaping unit 12 and the shaped reception wave, and outputs the time series data as the calculation result to the extraction unit 14. The correlation function calculation unit 13 sets the length of the time window at the time of the correlation function calculation by using the signal length of the transmission wave output from the transmission wave generation unit 1.
　抽出部１４は、相関関数演算部１３により演算された相関関数に基づいて、受信波の中から自車の送信波（つまり、自車信号６）に相当する成分を抽出する。抽出部１４は、相関関数の値が予め定められた閾値以上である場合に、自車信号６として抽出する。抽出部１４は、例えば、自車信号６の抽出位置である自車信号６の伝播時間を、障害物位置として出力する。 The extraction unit 14 extracts a component corresponding to the transmission wave of the own vehicle (that is, the own vehicle signal 6) from the received wave based on the correlation function calculated by the correlation function calculation unit 13. When the value of the correlation function is equal to or greater than a predetermined threshold value, the extraction unit 14 extracts the vehicle signal 6. For example, the extraction unit 14 outputs the propagation time of the own vehicle signal 6, which is the extraction position of the own vehicle signal 6, as an obstacle position.
　図２は、実施の形態１の送信波生成部１が出力する送信波の例を示すグラフである。図３Ａ、図３Ｂ、図３Ｃ、及び図３Ｄは、実施の形態１の送信波変形部３が出力する送信波と変形送信波の例を示すグラフである。これらのグラフにおいて、横軸は超音波送信素子５の送信開始時点を０ｍｓとした時間、縦軸は周波数である。 FIG. 2 is a graph showing an example of a transmitted wave output by the transmitted wave generation unit 1 of the first embodiment. 3A, 3B, 3C, and 3D are graphs showing an example of a transmission wave and a deformation transmission wave output by the transmission wave deformation unit 3 of the first embodiment. In these graphs, the horizontal axis is the time when the transmission start time of the ultrasonic wave transmitting element 5 is 0 ms, and the vertical axis is the frequency.
　図２に示されるように、送信波生成部１は、送信波として、周波数が４８ｋＨｚ、かつ、信号長が０．５ｍｓのバースト波を生成する。変形内容設定部２からの変形内容が、複製した送信波を２ｍｓ時間シフトさせるというものである場合、送信波変形部３は、図３Ａに示されるように送信波を複製して２ｍｓ時間シフトさせた変形送信波を生成する。 As shown in FIG. 2, the transmission wave generation unit 1 generates a burst wave having a frequency of 48 kHz and a signal length of 0.5 ms as a transmission wave. When the transformation content from the transformation content setting unit 2 is to shift the duplicated transmission wave by 2ms time, the transmission wave transformation unit 3 duplicates the transmission wave and shifts it by 2ms time as shown in FIG. 3A. Generates a modified transmitted wave.
　また、変形内容が、複製した送信波を３ｋＨｚ周波数シフトさせるというものである場合、送信波変形部３は、図３Ｂに示されるように送信波を複製して３ｋＨｚ周波数シフトさせた変形送信波を生成する。変形内容が、複製した送信波を２ｍｓ時間シフトさせると共に３ｋＨｚ周波数シフトさせるというものである場合、送信波変形部３は、図３Ｃに示されるように送信波を複製して２ｍｓ時間シフトさせると共に３ｋＨｚ周波数シフトさせた変形送信波を生成する。また、変形内容が、分割した一方の送信波を２ｍｓ時間シフトさせるというものである場合、送信波変形部３は、図３Ｄに示されるように送信波を分割し、分割した一方を送信波とし、もう一方を２ｍｓ時間シフトさせて変形送信波とする。 Further, when the modification content is to shift the duplicated transmission wave by 3 kHz frequency, the transmission wave deformation unit 3 duplicates the transmitted wave and shifts the frequency by 3 kHz as shown in FIG. 3B. Generate. When the content of the transformation is to shift the duplicated transmitted wave by 2 ms time and shift the frequency by 3 kHz, the transmitted wave transforming unit 3 duplicates the transmitted wave and shifts it by 2 ms time and 3 kHz as shown in FIG. 3C. Generates a frequency-shifted modified transmitted wave. Further, when the deformation content is to shift one of the divided transmission waves by 2 ms, the transmission wave deformation unit 3 divides the transmission wave as shown in FIG. 3D, and the divided one is used as the transmission wave. , The other is shifted by 2 ms to obtain a modified transmitted wave.
　なお、図３Ｂに示される例の場合、送信波を送信する超音波送信素子５と、変形送信波を送信する別の超音波送信素子５の２つが必要である。 In the case of the example shown in FIG. 3B, two ultrasonic wave transmitting elements 5 for transmitting a transmitted wave and another ultrasonic wave transmitting element 5 for transmitting a deformed transmitted wave are required.
　以下では、図３Ａに示される送信波と変形送信波とが、超音波送信素子５から自車信号６として送信された場合を例に用いる。自車信号６は、障害物７で反射して自車信号エコー８となり、超音波受信素子１０へと戻っていく。また、自車の走行により自車信号エコー８には１ｋＨｚのドップラシフトが生じていたものとする。 In the following, the case where the transmission wave and the modified transmission wave shown in FIG. 3A are transmitted from the ultrasonic transmission element 5 as the own vehicle signal 6 will be used as an example. The own vehicle signal 6 is reflected by the obstacle 7 to become the own vehicle signal echo 8, and returns to the ultrasonic receiving element 10. Further, it is assumed that the own vehicle signal echo 8 has a Doppler shift of 1 kHz due to the traveling of the own vehicle.
　超音波受信素子１０は、自車信号エコー８と、他車から送信された干渉波である他車信号９とを受信し、電圧に変換して受信回路１１へ出力する。受信回路１１は、超音波受信素子１０から出力された電圧を増幅してサンプリングし、受信波として出力する。 The ultrasonic receiving element 10 receives the own vehicle signal echo 8 and the other vehicle signal 9 which is an interference wave transmitted from another vehicle, converts it into a voltage, and outputs it to the receiving circuit 11. The receiving circuit 11 amplifies and samples the voltage output from the ultrasonic receiving element 10, and outputs it as a received wave.
　図４は、実施の形態１の受信回路１１が出力する受信波の例を示すグラフである。グラフの横軸は超音波送信素子５の送信開始時点を０ｍｓとした伝播時間、縦軸は周波数である。受信波には、自車信号６が障害物７で反射した自車信号エコー８と、他車が送信した他車信号９とが含まれる。上述のように、自車信号６の周波数は、ドップラシフトにより４８ｋＨｚから４９ｋＨｚに変化している。他車信号９は、周波数４７ｋＨｚ、及び信号長０．７５ｍｓのバースト波である。 FIG. 4 is a graph showing an example of a received wave output by the receiving circuit 11 of the first embodiment. The horizontal axis of the graph is the propagation time with the transmission start time of the ultrasonic wave transmitting element 5 as 0 ms, and the vertical axis is the frequency. The received wave includes the own vehicle signal echo 8 in which the own vehicle signal 6 is reflected by the obstacle 7, and the other vehicle signal 9 transmitted by the other vehicle. As described above, the frequency of the own vehicle signal 6 changes from 48 kHz to 49 kHz due to the Doppler shift. The other vehicle signal 9 is a burst wave having a frequency of 47 kHz and a signal length of 0.75 ms.
　図５は、実施の形態１の整形部１２が出力する整形受信波の例を示すグラフである。グラフの横軸は伝搬時間、縦軸は周波数である。ここでの変形内容は、複製した送信波を２ｍｓ時間シフトさせるというものであるため、整形部１２は、この時間シフトを戻すために、受信波を－２ｍｓ時間シフトさせた整形受信波を生成する。整形部１２は、整形前の受信波と、整形後の整形受信波とを、相関関数演算部１３へ出力する。 FIG. 5 is a graph showing an example of a shaped received wave output by the shaping unit 12 of the first embodiment. The horizontal axis of the graph is the propagation time, and the vertical axis is the frequency. Since the modified content here is to shift the duplicated transmitted wave by 2 ms time, the shaping unit 12 generates a shaped received wave obtained by shifting the received wave by -2 ms in order to return this time shift. .. The shaping unit 12 outputs the received wave before shaping and the shaped received wave after shaping to the correlation function calculation unit 13.
　相関関数演算部１３は、図４に示される受信波と、図５に示される整形受信波との相関関数を演算する。相関関数演算時の時間窓の長さは、送信波生成部１から出力された送信波の信号長である０．５ｍｓとする。 The correlation function calculation unit 13 calculates the correlation function between the received wave shown in FIG. 4 and the shaped received wave shown in FIG. The length of the time window at the time of the correlation function calculation is 0.5 ms, which is the signal length of the transmitted wave output from the transmitted wave generation unit 1.
　図６は、実施の形態１の相関関数演算部１３が出力する相関関数の例を示すグラフである。グラフの横軸は伝搬時間、縦軸は相関関数の値である。抽出部１４は、相関関数演算部１３から出力された相関関数の値と予め定められた閾値ＴＨ１とを比較する。１１．５ｍｓ付近の相関関数の値が、閾値ＴＨ１以上であるため、抽出部１４は、１１．５ｍｓ付近の受信波を自車信号６として抽出する。一方、他車信号９に相当する、受信波と整形受信波との相関関数の値は、閾値ＴＨ１未満であるため、抽出部１４により抽出されない。したがって、抽出部１４は、自車信号６と他車信号９とを識別することができる。なお、自車信号６は伝播距離が長くなるにつれて減衰するため、閾値ＴＨ１は、伝播時間の経過に伴い値が変化してもよい。 FIG. 6 is a graph showing an example of the correlation function output by the correlation function calculation unit 13 of the first embodiment. The horizontal axis of the graph is the propagation time, and the vertical axis is the value of the correlation function. The extraction unit 14 compares the value of the correlation function output from the correlation function calculation unit 13 with the predetermined threshold value TH1. Since the value of the correlation function around 11.5 ms is equal to or higher than the threshold value TH1, the extraction unit 14 extracts the received wave near 11.5 ms as the own vehicle signal 6. On the other hand, the value of the correlation function between the received wave and the shaped received wave, which corresponds to the other vehicle signal 9, is less than the threshold value TH1, and is not extracted by the extraction unit 14. Therefore, the extraction unit 14 can distinguish between the own vehicle signal 6 and the other vehicle signal 9. Since the own vehicle signal 6 is attenuated as the propagation distance becomes longer, the value of the threshold value TH1 may change with the passage of the propagation time.
　以上のように、実施の形態１に係る障害物検出装置１６は、送信波生成部１と、送信波変形部３と、送受信部１５と、整形部１２と、相関関数演算部１３と、抽出部１４とを備える。送信波生成部１は、送信波を生成する。送信波変形部３は、送信波を分割又は複製し変形した変形送信波を生成する。送受信部１５は、送信波と変形送信波とを自車信号６として送信し、障害物７で反射した自車信号エコー８を受信して受信波を出力する。整形部１２は、送信波変形部３の変形内容に基づいて受信波を整形した整形受信波を生成する。相関関数演算部１３は、受信波と整形受信波との相関関数を演算する。抽出部１４は、相関関数演算部１３により演算された相関関数に基づいて、受信波の中から自車信号６に相当する成分を抽出する。このように、障害物検出装置１６は、受信波と整形受信波との相関関数を演算するので、ドップラシフト等の伝播路における信号変形を補償せずとも、自車信号６の反射位置で相関関数の値が大きくなり、自車信号６を抽出することができる。したがって、障害物検出装置１６は、自車信号６と他車信号９とを識別することができる。 As described above, the obstacle detection device 16 according to the first embodiment extracts the transmission wave generation unit 1, the transmission wave deformation unit 3, the transmission / reception unit 15, the shaping unit 12, the correlation function calculation unit 13, and the correlation function calculation unit 13. A unit 14 is provided. The transmission wave generation unit 1 generates a transmission wave. The transmission wave deformation unit 3 divides or duplicates the transmission wave to generate a deformed transmission wave. The transmission / reception unit 15 transmits the transmission wave and the modified transmission wave as the own vehicle signal 6, receives the own vehicle signal echo 8 reflected by the obstacle 7, and outputs the received wave. The shaping unit 12 generates a shaped reception wave in which the received wave is shaped based on the deformation content of the transmission wave deformation unit 3. The correlation function calculation unit 13 calculates the correlation function between the received wave and the shaped received wave. The extraction unit 14 extracts a component corresponding to the own vehicle signal 6 from the received wave based on the correlation function calculated by the correlation function calculation unit 13. In this way, since the obstacle detection device 16 calculates the correlation function between the received wave and the shaped received wave, it correlates at the reflection position of the own vehicle signal 6 without compensating for the signal deformation in the propagation path such as Doppler shift. The value of the function becomes large, and the own vehicle signal 6 can be extracted. Therefore, the obstacle detection device 16 can distinguish between the own vehicle signal 6 and the other vehicle signal 9.
　また、特許文献１記載の障害物検出装置では、複数の超音波信号を識別する目的で、擬似ランダム系列に基づいて送信波を位相変調していた。擬似ランダム系列に基づいて送信波を位相変調する場合、車載用に広く使われている圧電セラミックスは、位相の変調に時間を要するため、長時間の励振が必要となり、寿命が短くなってしまう。これに対し、実施の形態１の障害物検出装置１６は、位相変調を行うことなく自車信号６と他車信号９とを識別することができるので、圧電セラミックスの寿命を保つことができる。 Further, in the obstacle detection device described in Patent Document 1, the transmitted wave is phase-modulated based on a pseudo-random sequence for the purpose of identifying a plurality of ultrasonic signals. When phase-modulating a transmitted wave based on a quasi-random sequence, piezoelectric ceramics widely used for automobiles require a long time for phase modulation, which requires long-time excitation and shortens the life. On the other hand, the obstacle detection device 16 of the first embodiment can distinguish the own vehicle signal 6 from the other vehicle signal 9 without performing phase modulation, so that the life of the piezoelectric ceramics can be maintained.
　また、実施の形態１によれば、送信波変形部３は、送信波の周波数又は時間の少なくとも一方をシフトさせた変形送信波を生成する。そのため、送信波の変形が容易である。加えて、この変形内容に基づく受信波の整形も容易である。 Further, according to the first embodiment, the transmission wave deformation unit 3 generates a deformation transmission wave in which at least one of the frequency and time of the transmission wave is shifted. Therefore, the transmitted wave is easily deformed. In addition, it is easy to shape the received wave based on this modification.
実施の形態２．
　図７は、実施の形態２に係る障害物検出装置１６の構成例を示すブロック図である。実施の形態２に係る障害物検出装置１６は、図１に示された実施の形態１の障害物検出装置１６における整形部１２と抽出部１４に代えて、整形部１２ａと抽出部１４ａを備える構成である。図７において図１と同一又は相当する部分は、同一の符号を付し説明を省略する。 Embodiment 2.
FIG. 7 is a block diagram showing a configuration example of the obstacle detection device 16 according to the second embodiment. The obstacle detection device 16 according to the second embodiment includes a shaping unit 12a and an extraction unit 14a in place of the shaping unit 12 and the extraction unit 14 in the obstacle detection device 16 of the first embodiment shown in FIG. It is a composition. In FIG. 7, the same or corresponding parts as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.
　図８は、実施の形態２の送信波変形部３が出力する送信波と変形送信波の例を示すグラフである。グラフの横軸は超音波送信素子５の送信開始時点を０ｍｓとした時間、縦軸は周波数である。図８に示されるように、送信波生成部１は、送信波として、周波数が４５ｋＨｚ、かつ、信号長が１ｍｓのバースト波を生成する。変形内容設定部２からの変形内容が、複製した送信波を１ｍｓ時間シフトさせると共に６ｋＨｚ周波数シフトさせるというものである場合、送信波変形部３は、この変形内容に基づいて周波数５１ｋＨｚの変形送信波を生成する。実施の形態２では、図８に示される送信波と変形送信波とが、超音波送信素子５から自車信号６として送信されるものとする。 FIG. 8 is a graph showing an example of a transmission wave and a deformation transmission wave output by the transmission wave deformation unit 3 of the second embodiment. The horizontal axis of the graph is the time when the transmission start time of the ultrasonic wave transmitting element 5 is 0 ms, and the vertical axis is the frequency. As shown in FIG. 8, the transmission wave generation unit 1 generates a burst wave having a frequency of 45 kHz and a signal length of 1 ms as the transmission wave. When the deformation content from the transformation content setting unit 2 is to shift the duplicated transmission wave by 1 ms time and 6 kHz frequency shift, the transmission wave deformation unit 3 is based on this transformation content and has a frequency of 51 kHz. To generate. In the second embodiment, it is assumed that the transmission wave and the modified transmission wave shown in FIG. 8 are transmitted from the ultrasonic transmission element 5 as the own vehicle signal 6.
　図９は、実施の形態２における障害物配置例を示す図であり、駐車場を上から見た状態である。自車１７は、一時停止中であり、これから、障害物検出装置１６により検出される障害物７ａ，７ｂ，７ｃの情報を用いて自動駐車しようとしている。障害物７ａである二輪車は、１４ｋｍ／ｈで自車１７へ近づいてきている。障害物７ｂである他車は、駐車区画内に停止中であり、他車信号９を送信している。障害物７ｃである他車は、２０ｋｍ／ｈで自車１７から遠ざかっている。自車１７と障害物７ａとの距離は１９７ｃｍ、自車１７と障害物７ｂとの距離は２０２ｃｍ、自車１７と障害物７ｃとの距離は２１０ｃｍである。 FIG. 9 is a diagram showing an example of obstacle placement in the second embodiment, and is a state in which the parking lot is viewed from above. The own vehicle 17 is temporarily stopped, and is about to automatically park using the information of obstacles 7a, 7b, and 7c detected by the obstacle detection device 16. The motorcycle, which is an obstacle 7a, is approaching its own vehicle 17 at 14 km / h. The other vehicle, which is the obstacle 7b, is stopped in the parking lot and transmits the other vehicle signal 9. The other vehicle, which is an obstacle 7c, is moving away from the own vehicle 17 at 20 km / h. The distance between the own vehicle 17 and the obstacle 7a is 197 cm, the distance between the own vehicle 17 and the obstacle 7b is 202 cm, and the distance between the own vehicle 17 and the obstacle 7c is 210 cm.
　自車１７の前部には、障害物検出装置１６の超音波送信素子５と超音波受信素子１０とが設置されている。超音波送信素子５から送信された自車信号６は、障害物７ａ，７ｂ，７ｃで反射して自車信号エコー８となり、超音波受信素子１０へと戻っていく。超音波受信素子１０は、自車信号エコー８と、障害物７ｂから送信された干渉波である他車信号９とを受信し、これらを電圧に変換して受信回路１１へ出力する。受信回路１１は、超音波受信素子１０から出力された電圧を増幅してサンプリングし、受信波として出力する。 The ultrasonic transmitting element 5 and the ultrasonic receiving element 10 of the obstacle detection device 16 are installed in the front part of the own vehicle 17. The own vehicle signal 6 transmitted from the ultrasonic transmitting element 5 is reflected by obstacles 7a, 7b, and 7c to become the own vehicle signal echo 8, and returns to the ultrasonic receiving element 10. The ultrasonic receiving element 10 receives the own vehicle signal echo 8 and the other vehicle signal 9 which is an interference wave transmitted from the obstacle 7b, converts them into a voltage, and outputs them to the receiving circuit 11. The receiving circuit 11 amplifies and samples the voltage output from the ultrasonic receiving element 10, and outputs it as a received wave.
　図１０および図１１は、実施の形態２の受信回路１１が出力する受信波の例を示すグラフである。図１０におけるグラフの横軸は超音波送信素子５の送信開始時点を０ｍｓとした伝播時間、縦軸は周波数である。図１１におけるグラフの横軸は超音波送信素子５の送信開始時点を０ｍｓとした伝播時間、縦軸は電圧値である。図１０において、便宜上、自車信号６に相当する受信波を、破線で囲まれた２グループに分ける。伝播時間が短く、かつ、周波数が低いグループは、送信波に相当する。伝播時間が長く、かつ、周波数が高いグループは、変形送信波に相当する。また、自車信号６に相当する２グループのそれぞれにおいて、最も周波数が高い受信波は障害物７ａで反射した自車信号６であり、２番目に周波数が高い受信波は障害物７ｂで反射した自車信号６であり、最も周波数が低い受信波は障害物７ｃで反射した自車信号６である。また、図１０において、他車信号９に相当する受信波を破線で囲む。 10 and 11 are graphs showing an example of a received wave output by the receiving circuit 11 of the second embodiment. The horizontal axis of the graph in FIG. 10 is the propagation time with the transmission start time of the ultrasonic wave transmitting element 5 as 0 ms, and the vertical axis is the frequency. The horizontal axis of the graph in FIG. 11 is the propagation time with the transmission start time of the ultrasonic wave transmitting element 5 as 0 ms, and the vertical axis is the voltage value. In FIG. 10, for convenience, the received wave corresponding to the own vehicle signal 6 is divided into two groups surrounded by a broken line. The group with short propagation time and low frequency corresponds to the transmitted wave. A group having a long propagation time and a high frequency corresponds to a modified transmitted wave. Further, in each of the two groups corresponding to the own vehicle signal 6, the received wave having the highest frequency is the own vehicle signal 6 reflected by the obstacle 7a, and the received wave having the second highest frequency is reflected by the obstacle 7b. The own vehicle signal 6 is the own vehicle signal 6, and the received wave having the lowest frequency is the own vehicle signal 6 reflected by the obstacle 7c. Further, in FIG. 10, the received wave corresponding to the other vehicle signal 9 is surrounded by a broken line.
　図１２は、実施の形態２における整形部１２ａの構成例を示すブロック図である。整形部１２ａは、検波部１２０１、ハイパスフィルタ１２１１、時間シフト部１２１２、周波数シフト部１２１３、及びローパスフィルタ１２２１を備える。 FIG. 12 is a block diagram showing a configuration example of the shaping portion 12a according to the second embodiment. The shaping unit 12a includes a detection unit 1201, a high-pass filter 1211, a time shift unit 1212, a frequency shift unit 1213, and a low-pass filter 1221.
　検波部１２０１は、受信回路１１から出力された受信波の時系列データを直交検波し、直交検波した受信波の時系列データをハイパスフィルタ１２１１及びローパスフィルタ１２２１へ出力する。 The detection unit 1201 orthogonally detects the time-series data of the received wave output from the receiving circuit 11, and outputs the time-series data of the received wave that has been orthogonally detected to the high-pass filter 1211 and the low-pass filter 1221.
　ハイパスフィルタ１２１１は、検波部１２０１から出力された受信波の低周波領域をカットし、高周波領域の受信波を時間シフト部１２１２へ出力する。ハイパスフィルタ１２１１のカットオフ周波数は、例えば、送信波の周波数４５ｋＨｚと変形送信波の周波数５１ｋＨｚとの中間の、４８ｋＨｚである。 The high-pass filter 1211 cuts the low frequency region of the received wave output from the detection unit 1201 and outputs the received wave in the high frequency region to the time shift unit 1212. The cutoff frequency of the high-pass filter 1211 is, for example, 48 kHz, which is between the frequency of the transmitted wave of 45 kHz and the frequency of the modified transmitted wave of 51 kHz.
　図１３は、実施の形態２のハイパスフィルタ１２１１が出力する高周波側の受信波の例を示すグラフである。グラフの横軸は伝搬時間、縦軸は周波数である。図１３に示されるように、自車信号６のうちの整形送信波に相当する自車信号６ａと、他車信号９のうちのカットオフ周波数より高周波側の他車信号９ａとが、ハイパスフィルタ１２１１から出力される。 FIG. 13 is a graph showing an example of a received wave on the high frequency side output by the high-pass filter 1211 of the second embodiment. The horizontal axis of the graph is the propagation time, and the vertical axis is the frequency. As shown in FIG. 13, the own vehicle signal 6a corresponding to the shaped transmission wave of the own vehicle signal 6 and the other vehicle signal 9a on the higher frequency side than the cutoff frequency of the other vehicle signal 9 are a high-pass filter. It is output from 1211.
　ローパスフィルタ１２２１は、検波部１２０１から出力された受信波の高周波領域をカットし、低周波領域の受信波を相関関数演算部１３及び抽出部１４ａへ出力する。ローパスフィルタ１２２１のカットオフ周波数は、例えば、ハイパスフィルタ１２１１と同じ４８ｋＨｚである。 The low-pass filter 1221 cuts the high frequency region of the received wave output from the detection unit 1201 and outputs the received wave in the low frequency region to the correlation function calculation unit 13 and the extraction unit 14a. The cutoff frequency of the low-pass filter 1221 is, for example, 48 kHz, which is the same as that of the high-pass filter 1211.
　図１４は、実施の形態２のローパスフィルタ１２２１が出力する低周波側の受信波の例を示すグラフである。グラフの伝播横軸は時間、縦軸は周波数である。図１４に示されるように、自車信号６のうちの送信波に相当する自車信号６ｂと、他車信号９のうちのカットオフ周波数より低周波側の他車信号９ｂとが、ローパスフィルタ１２２１から出力される。 FIG. 14 is a graph showing an example of a received wave on the low frequency side output by the low-pass filter 1221 of the second embodiment. Propagation of the graph The horizontal axis is time and the vertical axis is frequency. As shown in FIG. 14, the own vehicle signal 6b corresponding to the transmitted wave of the own vehicle signal 6 and the other vehicle signal 9b on the lower frequency side than the cutoff frequency of the other vehicle signal 9 are low-pass filters. It is output from 1221.
　なお、後述する抽出部１４ａが受信波の強度を抽出処理に用いない場合、ハイパスフィルタ１２１１及びローパスフィルタ１２２１のフィルタ処理は無くともよい。
　また、ハイパスフィルタ１２１１は、信号成分の存在しない低周波領域及び高周波領域をカットするような、バンドパスフィルタとして構成されていてもよい。同様に、ローパスフィルタ１２２１も、信号成分の存在しない低周波領域及び高周波領域をカットするような、バンドパスフィルタとして構成されていてもよい。 When the extraction unit 14a described later does not use the intensity of the received wave for the extraction process, the filter processing of the high-pass filter 1211 and the low-pass filter 1221 may not be necessary.
Further, the high-pass filter 1211 may be configured as a band-pass filter that cuts a low-frequency region and a high-frequency region in which no signal component exists. Similarly, the low-pass filter 1221 may also be configured as a band-pass filter that cuts low-frequency regions and high-frequency regions in which no signal component is present.
　時間シフト部１２１２は、変形内容設定部２で設定された変形内容である時間シフト量に基づいて、ハイパスフィルタ１２１１からの高周波側の受信波を－１ｍｓ時間シフトさせる。時間シフト部１２１２は、時間シフト後の高周波側の受信波を周波数シフト部１２１３へ出力する。 The time shift unit 1212 shifts the received wave on the high frequency side from the high-pass filter 1211 by -1 ms time based on the time shift amount which is the deformation content set by the deformation content setting unit 2. The time shift unit 1212 outputs the received wave on the high frequency side after the time shift to the frequency shift unit 1213.
　周波数シフト部１２１３は、変形内容設定部２で設定された変形内容である周波数シフト量に基づいて、時間シフト部１２１２からの高周波側の受信波を－６ｋＨｚ周波数シフトさせる。周波数シフトの手法としては、入力信号にフーリエ変換を行ったものを周波数軸上で移動させる手法でもよいし、入力信号を直交検波したものに対して時間に線形な位相シフト量を加える手法でもよい。周波数シフト部１２１３は、周波数シフト後の高周波側の受信波を、整形受信波として、相関関数演算部１３及び抽出部１４ａへ出力する。 The frequency shift unit 1213 shifts the received wave on the high frequency side from the time shift unit 1212 by -6 kHz frequency based on the frequency shift amount which is the deformation content set by the deformation content setting unit 2. The frequency shift method may be a method of moving the input signal subjected to Fourier transform on the frequency axis, or a method of adding a linear phase shift amount to the input signal orthogonally detected. .. The frequency shift unit 1213 outputs the received wave on the high frequency side after the frequency shift as a shaped reception wave to the correlation function calculation unit 13 and the extraction unit 14a.
　図１５は、実施の形態２の周波数シフト部１２１３が出力する整形受信波の例を示すグラフである。グラフの横軸は伝播時間、縦軸は周波数である。ここでの変形内容は、複製した送信波を１ｍｓ時間シフトさせると共に６ｋＨｚ周波数シフトさせるというものであるため、整形部１２ａは、この時間シフトと周波数シフトとを戻すために、高周波側の受信波である自車信号６ａ及び他車信号９ｂを－１ｍｓ時間シフトさせると共に－６ｋＨｚ周波数シフトさせた整形受信波を生成する。 FIG. 15 is a graph showing an example of a shaped received wave output by the frequency shift unit 1213 of the second embodiment. The horizontal axis of the graph is the propagation time, and the vertical axis is the frequency. Since the modified content here is to shift the duplicated transmission wave by 1 ms time and shift the frequency by 6 kHz, the shaping unit 12a uses the received wave on the high frequency side in order to return the time shift and the frequency shift. A shaped reception wave is generated by shifting a certain own vehicle signal 6a and another vehicle signal 9b by -1 ms time and shifting the frequency by -6 kHz.
　相関関数演算部１３は、図１４に示される低周波側の受信波と、図１５に示される整形受信波との相関関数を演算する。相関関数演算時の時間窓の長さは、送信波生成部１から出力された送信波の信号長である１ｍｓとする。 The correlation function calculation unit 13 calculates the correlation function between the received wave on the low frequency side shown in FIG. 14 and the shaped received wave shown in FIG. The length of the time window at the time of the correlation function calculation is 1 ms, which is the signal length of the transmitted wave output from the transmitted wave generation unit 1.
　図１６は、実施の形態２の相関関数演算部１３が出力する相関関数の例を示すグラフである。グラフの横軸は伝播時間、縦軸は相関関数の値である。図１６に示されるように、自車信号６の反射位置で相関関数の値が大きくなる。このように、相関関数演算部１３が低周波側の受信波と整形受信波との相関関数を演算することで、相互相関の低い他車信号９がノイズとして除去され、図１１に示される元の受信波形よりも信号対雑音の強度比率が向上する。また、低周波側の受信波と整形受信波との相関関数を演算するので、ドップラシフトを補償せずとも、自車信号６の反射位置で相関関数の値が大きくなる。 FIG. 16 is a graph showing an example of the correlation function output by the correlation function calculation unit 13 of the second embodiment. The horizontal axis of the graph is the propagation time, and the vertical axis is the value of the correlation function. As shown in FIG. 16, the value of the correlation function increases at the reflection position of the own vehicle signal 6. In this way, the correlation function calculation unit 13 calculates the correlation function between the received wave on the low frequency side and the shaped received wave, so that the other vehicle signal 9 having a low cross-correlation is removed as noise, and the source shown in FIG. The signal-to-noise intensity ratio is improved compared to the received waveform of. Further, since the correlation function between the received wave on the low frequency side and the shaped received wave is calculated, the value of the correlation function becomes large at the reflection position of the own vehicle signal 6 without compensating for the Doppler shift.
　図１７は、実施の形態２における抽出部１４ａの構成例を示すブロック図である。抽出部１４ａは、受信電力計算部１４０１、比較部１４０２、及び障害物候補位置検出部１４１１を備える。 FIG. 17 is a block diagram showing a configuration example of the extraction unit 14a according to the second embodiment. The extraction unit 14a includes a received power calculation unit 1401, a comparison unit 1402, and an obstacle candidate position detection unit 1411.
　障害物候補位置検出部１４１１は、相関関数演算部１３から出力された相関関数の絶対値が予め定められた閾値以上である位置を、障害物候補位置として検出し、検出した障害物候補位置を比較部１４０２へ出力する。 The obstacle candidate position detection unit 1411 detects a position where the absolute value of the correlation function output from the correlation function calculation unit 13 is equal to or higher than a predetermined threshold value as an obstacle candidate position, and detects the detected obstacle candidate position. Output to the comparison unit 1402.
　図１８は、実施の形態２の障害物候補位置検出部１４１１による処理を説明するためのグラフである。グラフの横軸は伝播時間、縦軸は相関関数の値（実線）と受信電力（破線）である。障害物候補位置検出部１４１１は、実線で示される相関関数の値が閾値ＴＨ２以上である１０．９ｍｓから１２．６ｍｓまでの位置と、１４．１ｍｓから１４．２ｍｓまでの位置とを、障害物候補位置Ｔ１，Ｔ２として検出する。この閾値ＴＨ２は、他車信号９等のノイズを除去するための閾値であり、障害物候補位置検出部１４１１に予め定められている。 FIG. 18 is a graph for explaining the processing by the obstacle candidate position detection unit 1411 of the second embodiment. The horizontal axis of the graph is the propagation time, and the vertical axis is the value of the correlation function (solid line) and the received power (broken line). The obstacle candidate position detection unit 1411 sets the position from 10.9 ms to 12.6 ms and the position from 14.1 ms to 14.2 ms when the value of the correlation function shown by the solid line is the threshold value TH2 or more. It is detected as candidate positions T1 and T2. This threshold value TH2 is a threshold value for removing noise such as another vehicle signal 9, and is predetermined in the obstacle candidate position detection unit 1411.
　受信電力計算部１４０１は、整形部１２ａから出力された整形受信波（図１５参照）と低周波側の受信波（図１４参照）とを用いて、受信電力を計算する。計算された受信電力の一例は、図１８に破線で示される。受信電力計算部１４０１は、計算した受信電力を比較部１４０２へ出力する。 The received power calculation unit 1401 calculates the received power using the shaped received wave (see FIG. 15) output from the shaping unit 12a and the received wave on the low frequency side (see FIG. 14). An example of the calculated received power is shown by the dashed line in FIG. The received power calculation unit 1401 outputs the calculated received power to the comparison unit 1402.
　相互相関関数は、Σｘ（ｔ）ｙ＊（ｔ）で計算されるのに対し、受信電力は、Σ｜ｘ（ｔ）ｙ（ｔ）｜で計算される。ｘ（ｔ）は、整形受信波の時系列データ、ｙ（ｔ）は、低周波側の受信波の時系列データである。ｙ＊（ｔ）は、ｙ（ｔ）の複素共役である。 The cross-correlation function is calculated by Σx (t) y * (t), while the received power is calculated by Σ | x (t) y (t) |. x (t) is the time series data of the well-formed reception wave, and y (t) is the time series data of the received wave on the low frequency side. y * (t) is the complex conjugate of y (t).
　比較部１４０２は、障害物候補位置検出部１４１１から障害物候補位置を、受信電力計算部１４０１から受信電力を、相関関数演算部１３から相関関数の演算結果を、それぞれ受け取る。そして、比較部１４０２は、障害物候補位置における受信電力と相関関数の絶対値とを比較する。比較部１４０２は、相関関数の絶対値が受信電力（つまり受信波の強度）に対して予め定められた割合以上である場合、この障害物候補位置が自車信号６の反射位置に相当し、この障害物候補位置に実際に障害物７ａ，７ｂ，７ｃがあったものと判定する。ただし、比較部１４０２は、１度の送信周期での判定で障害物７ａ，７ｂ，７ｃの有無を確定せず、複数の送信周期での複数の判定に基づいて障害物７ａ，７ｂ，７ｃの有無の確度を求めてもよい。比較部１４０２は、判定した障害物位置を出力する。 The comparison unit 1402 receives the obstacle candidate position from the obstacle candidate position detection unit 1411, the received power from the received power calculation unit 1401, and the calculation result of the correlation function from the correlation function calculation unit 13. Then, the comparison unit 1402 compares the received power at the obstacle candidate position with the absolute value of the correlation function. When the absolute value of the correlation function is equal to or greater than a predetermined ratio with respect to the received power (that is, the intensity of the received wave), the comparison unit 1402 indicates that the obstacle candidate position corresponds to the reflection position of the own vehicle signal 6. It is determined that the obstacles 7a, 7b, and 7c actually existed at the obstacle candidate positions. However, the comparison unit 1402 does not determine the presence or absence of the obstacles 7a, 7b, 7c by the determination in one transmission cycle, and the obstacles 7a, 7b, 7c are determined based on the plurality of determinations in the plurality of transmission cycles. The certainty of presence or absence may be obtained. The comparison unit 1402 outputs the determined obstacle position.
　ここで、受信電力と相関関数との大小関係は、Σ｜ｘ（ｔ）ｙ（ｔ）｜≧Σｘ（ｔ）ｙ＊（ｔ）であり、等号成立条件は、式（１）である。Ａｒｇ（ｘ（ｔ））は、ｘ（ｔ）の偏角である。すなわち、ｘ（ｔ）とｙ（ｔ）との位相差が全ての時間において一定値だった場合に、相関関数の絶対値は受信電力と同値となり、位相のばらつきが大きいほど相関関数の絶対値が小さくなる。したがって、比較部１４０２において受信電力に対する相関関数の大きさを観測することにより、受信波と整形受信波との類似度を正規化することができる。 Here, the magnitude relationship between the received power and the correlation function is Σ | x (t) y (t) | ≧ Σx (t) y * (t), and the condition for establishing the equal sign is the equation (1). .. Arg (x (t)) is the argument of x (t). That is, when the phase difference between x (t) and y (t) is a constant value at all times, the absolute value of the correlation function is the same as the received power, and the larger the phase variation, the more the absolute value of the correlation function. Becomes smaller. Therefore, the similarity between the received wave and the shaped received wave can be normalized by observing the magnitude of the correlation function with respect to the received power in the comparison unit 1402.

Figure JPOXMLDOC01-appb-I000001
Figure JPOXMLDOC01-appb-I000001
　図１９は、実施の形態２の比較部１４０２による処理を説明するためのグラフである。グラフの横軸は伝播時間、縦軸は受信電力に対する相関関数の割合である。図１９では、受信電力の６５％の値が、閾値ＴＨ３として用いられる。比較部１４０２は、障害物候補位置Ｔ１において、受信電力に対する相関関数の値が閾値ＴＨ３以上であるため、この障害物候補位置Ｔ１における相関関数の値が自車信号６の反射位置に相当し、この障害物候補位置に実際に障害物７ａ，７ｂ，７ｃがあったものと判定する。一方、比較部１４０２は、障害物候補位置Ｔ２において、受信電力に対する相関関数の値が閾値ＴＨ３未満であるため、この障害物候補位置Ｔ２における相関関数の値をノイズと判定する。 FIG. 19 is a graph for explaining the processing by the comparison unit 1402 of the second embodiment. The horizontal axis of the graph is the propagation time, and the vertical axis is the ratio of the correlation function to the received power. In FIG. 19, the value of 65% of the received power is used as the threshold TH3. In the comparison unit 1402, since the value of the correlation function with respect to the received power at the obstacle candidate position T1 is equal to or higher than the threshold value TH3, the value of the correlation function at the obstacle candidate position T1 corresponds to the reflection position of the own vehicle signal 6. It is determined that the obstacles 7a, 7b, and 7c actually existed at the obstacle candidate positions. On the other hand, since the value of the correlation function with respect to the received power at the obstacle candidate position T2 is less than the threshold value TH3, the comparison unit 1402 determines that the value of the correlation function at the obstacle candidate position T2 is noise.
　以上のように、実施の形態２の送信波変形部３は、送信波の周波数及び時間の双方をシフトさせた変形送信波を生成する。送信回路４が低コストな２値波形の駆動回路である場合、送信波の振幅は一定であるため、時間をシフトさせて送信時間を長くすることにより、送信パワーを大きくすることができる。つまり、周波数だけをシフトさせるよりも、周波数及び時間の双方をシフトさせるほうが送信パワーを大きくすることができる。この場合、障害物検出装置１６は、低コスト、かつ、信号対雑音比の高い超音波を送信することができる。 As described above, the transmission wave deformation unit 3 of the second embodiment generates a deformation transmission wave in which both the frequency and the time of the transmission wave are shifted. When the transmission circuit 4 is a low-cost binary waveform drive circuit, the amplitude of the transmission wave is constant, so that the transmission power can be increased by shifting the time to lengthen the transmission time. That is, the transmission power can be increased by shifting both the frequency and the time rather than shifting only the frequency. In this case, the obstacle detection device 16 can transmit ultrasonic waves at low cost and have a high signal-to-noise ratio.
　また、実施の形態２によれば、整形部１２ａは、受信波の周波数及び時間の双方をシフトさせる。送信波変形部３により周波数シフト及び時間シフトされた変形送信波に相当する受信波を、整形部１２ａが周波数シフト及び時間シフトして整形受信波を生成することにより、整形受信波と受信波との周波数が一致して相関関数の値が大きくなる。 Further, according to the second embodiment, the shaping unit 12a shifts both the frequency and the time of the received wave. The received wave corresponding to the modified transmitted wave frequency-shifted and time-shifted by the transmitted wave deforming unit 3 is frequency-shifted and time-shifted by the shaping unit 12a to generate the shaped received wave, thereby forming the shaped received wave and the received wave. The frequencies of are matched and the value of the correlation function becomes large.
　また、実施の形態２によれば、抽出部１４ａは、相関関数の値が受信波の強度に対して予め定められた割合以上である場合に送信波に相当する成分として抽出する。そのため、抽出部１４ａは、偶然波形の一部が整形受信波と類似している受信波を除外でき、類似している受信波だけを抽出することができる。 Further, according to the second embodiment, when the value of the correlation function is equal to or more than a predetermined ratio with respect to the intensity of the received wave, the extraction unit 14a extracts as a component corresponding to the transmitted wave. Therefore, the extraction unit 14a can exclude the received wave whose part of the waveform is similar to the shaped received wave by chance, and can extract only the received wave which is similar.
実施の形態３．
　図２０は、実施の形態３に係る障害物検出装置１６－１の構成例を示すブロック図である。実施の形態３に係る障害物検出装置１６－１は、図７に示された実施の形態２の障害物検出装置１６に対して他端末信号検出部１８－２が追加された構成である。他端末信号検出部１８－２は、整形部１２ａ－２、相関関数演算部１３－２、及び抽出部１４ａ－２を備える。整形部１２ａ－２、相関関数演算部１３－２、及び抽出部１４ａ－２は、図７に示された実施の形態２の障害物検出装置１６における整形部１２ａ、相関関数演算部１３、及び抽出部１４ａと同じものである。 Embodiment 3.
FIG. 20 is a block diagram showing a configuration example of the obstacle detection device 16-1 according to the third embodiment. The obstacle detection device 16-1 according to the third embodiment has a configuration in which another terminal signal detection unit 18-2 is added to the obstacle detection device 16 of the second embodiment shown in FIG. 7. The other terminal signal detection unit 18-2 includes a shaping unit 12a-2, a correlation function calculation unit 13-2, and an extraction unit 14a-2. The shaping unit 12a-2, the correlation function calculation unit 13-2, and the extraction unit 14a-2 are the shaping unit 12a, the correlation function calculation unit 13, and the correlation function calculation unit 13 in the obstacle detection device 16 of the second embodiment shown in FIG. It is the same as the extraction unit 14a.
　また、実施の形態３に係る障害物検出装置１６－１における整形部１２ａ－１、相関関数演算部１３－１、及び抽出部１４ａ－１は、図７に示された実施の形態２の障害物検出装置１６における整形部１２ａ、相関関数演算部１３、及び抽出部１４ａと同じものである。整形部１２ａ－１、相関関数演算部１３－１、及び抽出部１４ａ－１は、自端末信号検出部１８－１を構成する。
　なお、図２０において図１、図７、図１２、及び図１７と同一又は相当する部分は、同一の符号を付し説明を省略する。 Further, the shaping unit 12a-1, the correlation function calculation unit 13-1, and the extraction unit 14a-1 in the obstacle detection device 16-1 according to the third embodiment are the obstacles of the second embodiment shown in FIG. It is the same as the shaping unit 12a, the correlation function calculation unit 13, and the extraction unit 14a in the object detection device 16. The shaping unit 12a-1, the correlation function calculation unit 13-1, and the extraction unit 14a-1 constitute the own terminal signal detection unit 18-1.
In FIG. 20, the same or corresponding parts as those in FIGS. 1, 7, 12, and 17, are designated by the same reference numerals, and the description thereof will be omitted.
　障害物検出装置１６－２は、障害物検出装置１６－１と同じ構成であるため、説明を省略する。
　以下では、障害物検出装置１６－１から見て障害物検出装置１６－２は他端末であり、障害物検出装置１６－２から見て障害物検出装置１６－１は他端末であるものとする。 Since the obstacle detection device 16-2 has the same configuration as the obstacle detection device 16-1, the description thereof will be omitted.
In the following, it is assumed that the obstacle detection device 16-2 is another terminal when viewed from the obstacle detection device 16-1, and the obstacle detection device 16-1 is another terminal when viewed from the obstacle detection device 16-2. To do.
　図２１は、実施の形態３における障害物配置例を示す図であり、自車１７の周辺を上から見た状態である。自車１７の前方には、障害物７ｄ，７ｅ，７ｆが存在する。自車１７の前部には、障害物検出装置１６－１の超音波送信素子５及び超音波受信素子１０と、障害物検出装置１６－２の超音波送信素子５及び超音波受信素子１０とが設置されている。障害物検出装置１６－１の超音波送信素子５が送信する超音波を、自端末信号６－１と呼び、障害物検出装置１６－２の超音波送信素子５が送信する超音波を、他端末信号６－２と呼ぶ。 FIG. 21 is a diagram showing an example of obstacle arrangement in the third embodiment, and is a state in which the periphery of the own vehicle 17 is viewed from above. Obstacles 7d, 7e, 7f exist in front of the own vehicle 17. In the front part of the own vehicle 17, the ultrasonic transmission element 5 and the ultrasonic reception element 10 of the obstacle detection device 16-1 and the ultrasonic transmission element 5 and the ultrasonic reception element 10 of the obstacle detection device 16-2 are provided. Is installed. The ultrasonic waves transmitted by the ultrasonic wave transmitting element 5 of the obstacle detecting device 16-1 are called own terminal signals 6-1 and the ultrasonic waves transmitted by the ultrasonic wave transmitting element 5 of the obstacle detecting device 16-2 are referred to as the own terminal signal 6-1. It is called a terminal signal 6-2.
　障害物検出装置１６－１の超音波送信素子５から送信された自端末信号６－１は、障害物７ｄ，７ｅ，７ｆで反射して自端末信号エコーとなり、障害物検出装置１６－１の超音波受信素子１０と障害物検出装置１６－２の超音波受信素子１０とへ戻っていく。同様に、障害物検出装置１６－２の超音波送信素子５から送信された他端末信号６－２は、障害物７ｄ，７ｅ，７ｆで反射して他端末信号エコーとなり、障害物検出装置１６－１の超音波受信素子１０と障害物検出装置１６－２の超音波受信素子１０とへ戻っていく。 The own terminal signal 6-1 transmitted from the ultrasonic transmission element 5 of the obstacle detection device 16-1 is reflected by the obstacles 7d, 7e, and 7f to become the own terminal signal echo, and the obstacle detection device 16-1 It returns to the ultrasonic receiving element 10 and the ultrasonic receiving element 10 of the obstacle detection device 16-2. Similarly, the other terminal signal 6-2 transmitted from the ultrasonic transmission element 5 of the obstacle detection device 16-2 is reflected by the obstacles 7d, 7e, and 7f to become another terminal signal echo, and the obstacle detection device 16 It returns to the ultrasonic receiving element 10 of -1 and the ultrasonic receiving element 10 of the obstacle detection device 16-2.
　なお、自車１７の前部において、障害物検出装置１６－１の超音波送信素子５及び超音波受信素子１０と、障害物検出装置１６－２の超音波送信素子５及び超音波受信素子１０とは、自車１７の左右方向にずれて設置されている。そのため、例えば、障害物検出装置１６－１から障害物７ｄまでの距離が２００ｃｍであるのに対し、障害物検出装置１６－２から障害物７ｄまでの距離は２０５ｃｍである。 In the front part of the own vehicle 17, the ultrasonic transmission element 5 and the ultrasonic reception element 10 of the obstacle detection device 16-1 and the ultrasonic transmission element 5 and the ultrasonic reception element 10 of the obstacle detection device 16-2. Is installed so as to be offset in the left-right direction of the own vehicle 17. Therefore, for example, the distance from the obstacle detection device 16-1 to the obstacle 7d is 200 cm, while the distance from the obstacle detection device 16-2 to the obstacle 7d is 205 cm.
　障害物検出装置１６－１の送信波生成部１は、送信波の信号長を、障害物検出装置１６－１の相関関数演算部１３－１と抽出部１４ａ－１へ出力する。加えて、障害物検出装置１６－１の送信波生成部１は、送信波の信号長を、障害物検出装置１６－２へ出力する。また、障害物検出装置１６－１の変形内容設定部２は、変形内容を、障害物検出装置１６－１の送信波変形部３と整形部１２ａ－１へ出力する。加えて、障害物検出装置１６－１の変形内容設定部２は、変形内容を、障害物検出装置１６－２へ出力する。障害物検出装置１６－１の相関関数演算部１３－２と抽出部１４ａ－２は、障害物検出装置１６－２から出力される送信波の信号長を取得する。また、障害物検出装置１６－１の整形部１２ａ－１は、障害物検出装置１６－２から出力される変形内容を取得する。 The transmission wave generation unit 1 of the obstacle detection device 16-1 outputs the signal length of the transmission wave to the correlation function calculation unit 13-1 and the extraction unit 14a-1 of the obstacle detection device 16-1. In addition, the transmission wave generation unit 1 of the obstacle detection device 16-1 outputs the signal length of the transmission wave to the obstacle detection device 16-2. Further, the deformation content setting unit 2 of the obstacle detection device 16-1 outputs the deformation content to the transmission wave deformation unit 3 and the shaping unit 12a-1 of the obstacle detection device 16-1. In addition, the deformation content setting unit 2 of the obstacle detection device 16-1 outputs the deformation content to the obstacle detection device 16-2. The correlation function calculation unit 13-2 and the extraction unit 14a-2 of the obstacle detection device 16-1 acquire the signal length of the transmission wave output from the obstacle detection device 16-2. Further, the shaping unit 12a-1 of the obstacle detection device 16-1 acquires the deformation content output from the obstacle detection device 16-2.
　自端末信号検出部１８－１は、受信回路１１から出力された自端末信号６－１と他端末信号６－２とが混在している受信波に対して、障害物検出装置１６－１の変形内容設定部２からの変形内容と送信波生成部１からの送信波の信号長とを用いて実施の形態２と同様の整形、相関関数演算、及び抽出処理を行うことにより、自端末信号６－１の反射位置を検出する。他端末信号検出部１８－２は、受信回路１１から出力された自端末信号６－１と他端末信号６－２とが混在している受信波に対して、障害物検出装置１６－２からの変形内容と送信波の信号長とを用いて実施の形態２と同様の整形、相関関数演算、及び抽出処理を行うことにより、他端末信号６－２の反射位置を検出する。このように、障害物検出装置１６－１と障害物検出装置１６－２とは、他端末信号の整形に必要な信号長及び変形内容の情報を互いに共有し、その情報を用いて他端末信号検出部１８－２において整形等の処理を行うことで、双方の信号を識別することができる。なお、実施の形態３においては、信号長及び変形内容の情報の共有は、障害物検出装置１６－１，１６－２間で直接行われているが、この構成に限定されるものではない。例えば、図示しない管理装置が、障害物検出装置１６－１の信号長及び変形内容の情報と、障害物検出装置１６－２の信号長及び変形内容の情報とを管理し、これらの情報を障害物検出装置１６－１，１６－２へ出力する。 The local terminal signal detection unit 18-1 of the obstacle detection device 16-1 with respect to the received wave in which the local terminal signal 6-1 output from the receiving circuit 11 and the other terminal signal 6-2 are mixed. The own terminal signal is performed by performing the same shaping, correlation function calculation, and extraction processing as in the second embodiment using the deformation content from the transformation content setting unit 2 and the signal length of the transmission wave from the transmission wave generation unit 1. The reflection position of 6-1 is detected. The other terminal signal detection unit 18-2 receives the received wave in which the own terminal signal 6-1 and the other terminal signal 6-2 output from the reception circuit 11 are mixed from the obstacle detection device 16-2. The reflection position of the other terminal signal 6-2 is detected by performing the same shaping, correlation function calculation, and extraction processing as in the second embodiment using the modified contents of the above and the signal length of the transmitted wave. In this way, the obstacle detection device 16-1 and the obstacle detection device 16-2 share information on the signal length and deformation contents necessary for shaping the signal of the other terminal, and use the information to signal the other terminal. Both signals can be identified by performing processing such as shaping in the detection unit 18-2. In the third embodiment, the information on the signal length and the deformation content is shared directly between the obstacle detection devices 16-1 and 16-2, but the configuration is not limited to this. For example, a management device (not shown) manages information on the signal length and deformation content of the obstacle detection device 16-1 and information on the signal length and deformation content of the obstacle detection device 16-2, and obtains these information as obstacles. Output to object detection devices 16-1 and 16-2.
　図２２は、実施の形態３に係る障害物検出装置１６－１の送信波変形部３が出力する送信波と変形送信波の例を示すグラフである。図２３は、実施の形態３に係る障害物検出装置１６－２の送信波変形部３が出力する送信波と変形送信波の例を示すグラフである。これらのグラフにおいて、横軸は障害物検出装置１６－１の送信開始時点を０ｍｓとした時間、縦軸は周波数である。障害物検出装置１６－１の送信波及び変形送信波と、障害物検出装置１６－２の送信波及び変形送信波とは、異なるものである。図２２及び図２３の例では、障害物検出装置１６－１の送信タイミングと障害物検出装置１６－２の送信タイミングとは異なっているが、同時であってもよい。なお、送信タイミングが異なる場合、近距離の障害物を検出する際の干渉波の強度を抑えることができるため、近距離の障害物を確実に検出することができる。 FIG. 22 is a graph showing an example of a transmission wave and a deformation transmission wave output by the transmission wave deformation unit 3 of the obstacle detection device 16-1 according to the third embodiment. FIG. 23 is a graph showing an example of a transmission wave and a deformation transmission wave output by the transmission wave deformation unit 3 of the obstacle detection device 16-2 according to the third embodiment. In these graphs, the horizontal axis is the time when the transmission start time of the obstacle detection device 16-1 is 0 ms, and the vertical axis is the frequency. The transmission wave and the deformation transmission wave of the obstacle detection device 16-1 and the transmission wave and the deformation transmission wave of the obstacle detection device 16-2 are different from each other. In the examples of FIGS. 22 and 23, the transmission timing of the obstacle detection device 16-1 and the transmission timing of the obstacle detection device 16-2 are different, but they may be simultaneous. When the transmission timings are different, the intensity of the interference wave when detecting an obstacle at a short distance can be suppressed, so that the obstacle at a short distance can be reliably detected.
　また、図２２及び図２３に示される例では、超音波送信素子５及び超音波受信素子１０の固有振動数である４８ｋＨｚを中心にして対称の関係になるように、送信波の周波数と変形送信波の周波数とが設定されている。 Further, in the examples shown in FIGS. 22 and 23, the frequency of the transmitted wave and the modified transmission are so as to have a symmetric relationship about 48 kHz, which is the natural frequency of the ultrasonic transmitting element 5 and the ultrasonic receiving element 10. The frequency of the wave is set.
　図２４は、実施の形態３に係る障害物検出装置１６－１の受信回路１１が出力する受信波の例を示すグラフである。グラフの横軸は超音波送信素子５の送信開始時間を０ｍｓとした伝播時間、縦軸は電圧値である。受信回路１１が出力する受信波には、自端末信号６－１と他端末信号６－２とが含まれる。自端末信号６－１に相当する受信波のうち、最も伝播時間が短い受信波は障害物７ｄで反射したものであり、２番目に伝播時間が短い受信波は障害物７ｅで反射したものであり、最も伝播時間が長い受信波は障害物７ｆで反射したものである。また、他端末信号６－２に相当する受信波のうち、最も伝播時間が短い受信波は障害物７ｄで反射したものであり、２番目に伝播時間が短い受信波は障害物７ｅで反射したものであり、最も伝播時間が長い受信波は障害物７ｆで反射したものである。 FIG. 24 is a graph showing an example of a received wave output by the receiving circuit 11 of the obstacle detection device 16-1 according to the third embodiment. The horizontal axis of the graph is the propagation time with the transmission start time of the ultrasonic wave transmitting element 5 as 0 ms, and the vertical axis is the voltage value. The received wave output by the receiving circuit 11 includes the own terminal signal 6-1 and the other terminal signal 6-2. Of the received waves corresponding to the own terminal signal 6-1, the received wave having the shortest propagation time is reflected by the obstacle 7d, and the received wave having the second shortest propagation time is reflected by the obstacle 7e. The received wave with the longest propagation time is the one reflected by the obstacle 7f. Among the received waves corresponding to the other terminal signal 6-2, the received wave having the shortest propagation time is reflected by the obstacle 7d, and the received wave having the second shortest propagation time is reflected by the obstacle 7e. The received wave with the longest propagation time is the one reflected by the obstacle 7f.
　自端末信号検出部１８－１の整形部１２ａ－１は、受信回路１１から出力された受信波を、自端末の変形内容を用いて整形し、受信波と整形受信波とを相関関数演算部１３－１及び抽出部１４ａ－１へ出力する。相関関数演算部１３－１は、自端末の信号長を用いて、受信波と整形受信波との相関関数を演算し、演算結果を抽出部１４ａ－１へ出力する。抽出部１４ａ－１は、受信波と整形受信波とを用いて受信電力を計算し、受信電力と相関関数の演算結果とを用いて受信波に含まれる自端末信号６－１を抽出する。 The shaping unit 12a-1 of the own terminal signal detection unit 18-1 shapes the received wave output from the receiving circuit 11 using the modified contents of the own terminal, and shapes the received wave and the shaped received wave into a correlation function calculation unit. Output to 13-1 and extraction unit 14a-1. The correlation function calculation unit 13-1 calculates the correlation function between the received wave and the shaped reception wave using the signal length of the own terminal, and outputs the calculation result to the extraction unit 14a-1. The extraction unit 14a-1 calculates the received power using the received wave and the shaped reception wave, and extracts the own terminal signal 6-1 included in the received wave using the received power and the calculation result of the correlation function.
　図２５は、実施の形態３の自端末信号検出部１８－１において計算される相関関数の値と受信電力の例を示すグラフである。グラフの横軸は伝播時間、縦軸は相関関数の値（実線）と受信電力（破線）である。抽出部１４ａ－１は、図２５に示される相関関数の値が閾値ＴＨ２以上である位置を障害物候補位置として検出する。図２４に示される整形前の受信電圧と、図２５に示される整形後の受信電力とを比較すると、他端末信号６－２に相当する受信波の強度が低下している。そのため、他端末信号６－２が障害物候補位置として検出されにくくなり、誤検出が抑制される。 FIG. 25 is a graph showing an example of the value of the correlation function and the received power calculated by the local terminal signal detection unit 18-1 of the third embodiment. The horizontal axis of the graph is the propagation time, and the vertical axis is the value of the correlation function (solid line) and the received power (broken line). The extraction unit 14a-1 detects a position where the value of the correlation function shown in FIG. 25 is equal to or higher than the threshold value TH2 as an obstacle candidate position. Comparing the received voltage before shaping shown in FIG. 24 with the received power after shaping shown in FIG. 25, the intensity of the received wave corresponding to the other terminal signal 6-2 is reduced. Therefore, the other terminal signal 6-2 is less likely to be detected as an obstacle candidate position, and erroneous detection is suppressed.
　図２６は、実施の形態３の自端末信号検出部１８－１において計算される受信電力に対する相関関数の割合の例を示すグラフである。グラフの横軸は伝播時間、縦軸は受信電力に対する相関関数の割合である。図２６では、受信電力の８５％の値が、閾値ＴＨ３として用いられる。抽出部１４ａ－１は、障害物候補位置において受信電力に対する相関関数の値が閾値ＴＨ３以上である場合、この障害物候補位置が自端末信号６－１の反射位置に相当し、この障害物候補位置に実際に障害物７ｄ，７ｅ，７ｆがあったものと判定する。なお、抽出部１４ａ－１は、受信電力に対する相関関数の値が閾値ＴＨ３以上であるか否かだけでなく、閾値ＴＨ３以上となる継続時間又は頻度等を用いて、障害物７ｄ，７ｅ，７ｆの有無を確定してもよい。図２６に示されるように、自端末信号６－１の反射位置以外の部分では、受信電力に対する相関関数の値が閾値ＴＨ３未満であるため、抽出部１４ａ－１は、自端末信号６－１と他端末信号６－２とを正しく識別できる。 FIG. 26 is a graph showing an example of the ratio of the correlation function to the received power calculated by the local terminal signal detection unit 18-1 of the third embodiment. The horizontal axis of the graph is the propagation time, and the vertical axis is the ratio of the correlation function to the received power. In FIG. 26, a value of 85% of the received power is used as the threshold TH3. When the value of the correlation function with respect to the received power at the obstacle candidate position is equal to or higher than the threshold value TH3, the extraction unit 14a-1 corresponds to the reflection position of the own terminal signal 6-1 and the obstacle candidate. It is determined that there are actually obstacles 7d, 7e, 7f at the position. The extraction unit 14a-1 uses not only whether or not the value of the correlation function with respect to the received power is the threshold value TH3 or more, but also the duration or frequency at which the threshold value is TH3 or more, and the obstacles 7d, 7e, 7f. You may decide the presence or absence of. As shown in FIG. 26, since the value of the correlation function with respect to the received power is less than the threshold value TH3 in the portion other than the reflection position of the own terminal signal 6-1, the extraction unit 14a-1 uses the own terminal signal 6-1. And the other terminal signal 6-2 can be correctly distinguished.
　他端末信号検出部１８－２も、自端末信号検出部１８－１と同様に、受信回路１１から出力された受信波を処理することによって、この受信波に含まれる自端末信号６－１と他端末信号６－２とを識別する。 Like the own terminal signal detection unit 18-1, the other terminal signal detection unit 18-2 also processes the reception wave output from the reception circuit 11 to obtain the own terminal signal 6-1 included in the reception wave. Distinguish from other terminal signal 6-2.
　図２７は、実施の形態３の他端末信号検出部１８－２において計算される相関関数の値と受信電力の例を示すグラフである。グラフの横軸は伝播時間、縦軸は相関関数の値（実線）と受信電力（破線）である。抽出部１４ａ－２は、図２７に示される相関関数の値が閾値ＴＨ２以上である位置を障害物候補位置として検出する。図２４に示される整形前の受信電圧と、図２７に示される整形後の受信電力とを比較すると、自端末信号６－１に相当する受信波の強度が低下している。そのため、自端末信号６－１が障害物候補位置として検出されにくくなり、誤検出が抑制される。 FIG. 27 is a graph showing an example of the value of the correlation function and the received power calculated by the other terminal signal detection unit 18-2 of the third embodiment. The horizontal axis of the graph is the propagation time, and the vertical axis is the value of the correlation function (solid line) and the received power (broken line). The extraction unit 14a-2 detects a position where the value of the correlation function shown in FIG. 27 is the threshold value TH2 or more as an obstacle candidate position. Comparing the received voltage before shaping shown in FIG. 24 with the received power after shaping shown in FIG. 27, the intensity of the received wave corresponding to the own terminal signal 6-1 is reduced. Therefore, the own terminal signal 6-1 is less likely to be detected as an obstacle candidate position, and erroneous detection is suppressed.
　図２８は、実施の形態３の他端末信号検出部１８－２において計算される受信電力に対する相関関数の割合の例を示すグラフである。グラフの横軸は伝播時間、縦軸は受信電力に対する相関関数の割合である。抽出部１４ａ－２は、障害物候補位置において受信電力に対する相関関数の値が閾値ＴＨ３以上である場合、この障害物候補位置が他端末信号６－２の反射位置に相当し、この障害物候補位置に実際に障害物７ｄ，７ｅ，７ｆがあったものと判定する。図２８に示されるように、他端末信号６－２の反射位置以外の部分では、受信電力に対する相関関数の値が閾値ＴＨ３未満であるため、抽出部１４ａ－２は、自端末信号６－１と他端末信号６－２とを正しく識別できる。 FIG. 28 is a graph showing an example of the ratio of the correlation function to the received power calculated by the other terminal signal detection unit 18-2 of the third embodiment. The horizontal axis of the graph is the propagation time, and the vertical axis is the ratio of the correlation function to the received power. When the value of the correlation function with respect to the received power at the obstacle candidate position is equal to or higher than the threshold value TH3, the extraction unit 14a-2 corresponds to the reflection position of the other terminal signal 6-2, and the obstacle candidate position corresponds to the reflection position of the other terminal signal 6-2. It is determined that there are actually obstacles 7d, 7e, 7f at the position. As shown in FIG. 28, since the value of the correlation function with respect to the received power is less than the threshold value TH3 in the portion other than the reflection position of the other terminal signal 6-2, the extraction unit 14a-2 uses the own terminal signal 6-1. And the other terminal signal 6-2 can be correctly distinguished.
　抽出部１４ａ－１が出力する自端末信号６－１の反射位置と、抽出部１４ａ－２が出力する他端末信号６－２の反射位置は、例えば、自動駐車を行うＥＣＵ（Ｅｌｅｃｔｒｏｎｉｃ　Ｃｏｎｔｒｏｌ　Ｕｎｉｔ）において開口合成処理又は二円交点処理に用いられる。開口合成処理又は二円交点処理により障害物の二次元座標位置が算出される。 The reflection position of the own terminal signal 6-1 output by the extraction unit 14a-1 and the reflection position of the other terminal signal 6-2 output by the extraction unit 14a-2 are, for example, an ECU (Electronic Control Unit) that automatically parks. It is used for aperture synthesis processing or two-circle intersection processing. The two-dimensional coordinate position of the obstacle is calculated by the aperture synthesis process or the two-circle intersection process.
　以上のように、実施の形態３に係る障害物検出装置１６－１，１６－２は、送信波と変形送信波とを１組とし、波形の異なる２組の送信波と変形送信波とを出力する。この場合、障害物検出装置１６－１，１６－２は、自端末信号６－１と他端末信号６－２とが混信した受信波から、自端末信号６－１と他端末信号６－２とを抽出することができる。そのため、障害物検出装置１６－１，１６－２は、自端末信号６－１と他端末信号６－２を多重化することができ、送信周期を短縮することができる。 As described above, the obstacle detection devices 16-1 and 16-2 according to the third embodiment have one set of the transmitted wave and the modified transmitted wave, and two sets of the transmitted wave and the modified transmitted wave having different waveforms. Output. In this case, the obstacle detection devices 16-1 and 16-2 receive the own terminal signal 6-1 and the other terminal signal 6-2 from the received wave in which the own terminal signal 6-1 and the other terminal signal 6-2 interfere with each other. And can be extracted. Therefore, the obstacle detection devices 16-1 and 16-2 can multiplex the own terminal signal 6-1 and the other terminal signal 6-2, and can shorten the transmission cycle.
　なお、実施の形態３では、障害物検出装置１６－１が１組の送信波と変形送信波とを送信し、障害物検出装置１６－２が波形の異なるもう１組の送信波と変形送信波とを送信する構成であったが、この構成に限定されるものではない。例えば、障害物検出装置１６－１が２つの送受信部１５を備え、一方の送受信部１５が図２２に示される送信波と変形送信波とを自端末信号６－１として送信し、もう一方の送受信部１５が図２３に示される送信波と変形送信波とを他端末信号６－２として送信する構成であってもよい。この構成の場合、変形内容設定部２は、２種類の変形内容を保持しており、送信波変形部３は、一方の変形内容に基づいて図２２に示される変形送信波を生成し、もう一方の変形内容に基づいて図２３に示される変形送信波を生成する。自端末信号検出部１８－１は、一方の送受信部１５からの受信波を処理し、他端末信号検出部１８－２は、もう一方の送受信部１５からの受信波を処理する。この構成の場合にも、障害物検出装置１６－１は、自端末信号６－１と他端末信号６－２とが混信した受信波から、自端末信号６－１と他端末信号６－２とを抽出することができ、送信周期を短縮することができる。 In the third embodiment, the obstacle detection device 16-1 transmits one set of transmission waves and the modified transmission wave, and the obstacle detection device 16-2 transmits another set of transmission waves having different waveforms and deformation transmission. Although it was configured to transmit waves, it is not limited to this configuration. For example, the obstacle detection device 16-1 includes two transmission / reception units 15, one transmission / reception unit 15 transmits the transmission wave and the modified transmission wave shown in FIG. 22 as the own terminal signal 6-1 and the other transmission / reception unit 15. The transmission / reception unit 15 may be configured to transmit the transmission wave and the modified transmission wave shown in FIG. 23 as another terminal signal 6-2. In the case of this configuration, the deformation content setting unit 2 holds two types of deformation contents, and the transmission wave deformation unit 3 generates the deformation transmission wave shown in FIG. 22 based on one of the deformation contents. The deformed transmission wave shown in FIG. 23 is generated based on one of the deformed contents. The own terminal signal detection unit 18-1 processes the received wave from one transmission / reception unit 15, and the other terminal signal detection unit 18-2 processes the reception wave from the other transmission / reception unit 15. Even in this configuration, the obstacle detection device 16-1 uses the received wave in which the own terminal signal 6-1 and the other terminal signal 6-2 interfere with each other to generate the own terminal signal 6-1 and the other terminal signal 6-2. And can be extracted, and the transmission cycle can be shortened.
　また、実施の形態３によれば、送信波の周波数と変形送信波の周波数とは、超音波送信素子５の固有振動数を中心に対称の関係にある。障害物検出装置１６－１，１６－２は、超音波送信素子５の感度が最も大きい周波数領域を使用することができるので、信号対雑音比の高い超音波を送信することができる。 Further, according to the third embodiment, the frequency of the transmitted wave and the frequency of the modified transmitted wave have a symmetrical relationship with respect to the natural frequency of the ultrasonic transmitting element 5. Since the obstacle detection devices 16-1 and 16-2 can use the frequency region having the highest sensitivity of the ultrasonic wave transmitting element 5, it is possible to transmit ultrasonic waves having a high signal-to-noise ratio.
　なお、送信波の周波数と変形送信波の周波数とは、超音波送信素子５の固有振動数からシフトした周波数を中心に対称の関係にあってもよい。例えば、超音波送信素子５の超音波送信素子５の固有振動数が４８ｋＨｚである場合、この固有振動数から－３ｋＨｚシフトした４５ｋＨｚを中心に対称の関係にある、４２ｋＨｚの送信波と４８ｋＨｚの変形送信波とが生成される。障害物検出装置１６－１，１６－２は、固有振動数から離れた周波数を使用することで、超音波送信素子５の残響により発生した信号成分の、受信波への影響を抑制することができる。 Note that the frequency of the transmitted wave and the frequency of the modified transmitted wave may have a symmetrical relationship with respect to the frequency shifted from the natural frequency of the ultrasonic transmitting element 5. For example, when the natural frequency of the ultrasonic transmitting element 5 of the ultrasonic transmitting element 5 is 48 kHz, the transmitted wave of 42 kHz and the deformation of 48 kHz are symmetrical with respect to 45 kHz shifted by -3 kHz from this natural frequency. A transmitted wave is generated. Obstacle detection devices 16-1 and 16-2 can suppress the influence of the signal component generated by the reverberation of the ultrasonic transmitting element 5 on the received wave by using a frequency away from the natural frequency. it can.
実施の形態４．
　実施の形態４では、実施の形態３における他端末信号６－２の波形を変更した例を説明する。
　なお、実施の形態４に係る障害物検出装置１６－１，１６－２の構成は、実施の形態３の図２０に示された構成と図面上は同一であるため、以下では図２０を援用する。また、実施の形態４における障害物配置例として、実施の形態３の図２１を援用する。 Embodiment 4.
In the fourth embodiment, an example in which the waveform of the other terminal signal 6-2 in the third embodiment is changed will be described.
Since the configurations of the obstacle detection devices 16-1 and 16-2 according to the fourth embodiment are the same as the configurations shown in FIG. 20 of the third embodiment on the drawing, FIG. 20 is incorporated below. To do. Further, as an example of obstacle placement in the fourth embodiment, FIG. 21 of the third embodiment is incorporated.
　図２９は、実施の形態４に係る障害物検出装置１６－１の送信波変形部３が出力する送信波と変形送信波の例を示すグラフである。図３０は、実施の形態４に係る障害物検出装置１６－２の送信波変形部３が出力する送信波と変形送信波の例を示すグラフである。これらのグラフにおいて、横軸は障害物検出装置１６－１の送信開始時点を０ｍｓとした時間、縦軸は周波数である。図３０に示されるように、変形送信波は１ｍｓ時間シフトされているため、送信波と変形送信波との間に１ｍｓの休止区間が存在する。 FIG. 29 is a graph showing an example of a transmission wave and a deformation transmission wave output by the transmission wave deformation unit 3 of the obstacle detection device 16-1 according to the fourth embodiment. FIG. 30 is a graph showing an example of a transmission wave and a deformation transmission wave output by the transmission wave deformation unit 3 of the obstacle detection device 16-2 according to the fourth embodiment. In these graphs, the horizontal axis is the time when the transmission start time of the obstacle detection device 16-1 is 0 ms, and the vertical axis is the frequency. As shown in FIG. 30, since the modified transmitted wave is shifted by 1 ms time, there is a 1 ms pause section between the transmitted wave and the modified transmitted wave.
　図３１は、実施の形態４に係る障害物検出装置１６－１の受信回路１１が出力する受信波の例を示すグラフである。グラフの横軸は超音波送信素子５の送信開始時間を０ｍｓとした伝播時間、縦軸は電圧値である。受信回路１１が出力する受信波には、自端末信号６－１と他端末信号６－２とが含まれる。自端末信号６－１に相当する受信波のうち、最も伝播時間が短い受信波は障害物７ｄで反射したものであり、２番目に伝播時間が短い受信波は障害物７ｅで反射したものであり、最も伝播時間が長い受信波は障害物７ｆで反射したものである。また、他端末信号６－２に相当する受信波のうち、最も伝播時間が短い受信波は障害物７ｄで反射したものであり、２番目に伝播時間が短い受信波は障害物７ｅで反射したものであり、最も伝播時間が長い受信波は障害物７ｆで反射したものである。なお、他端末信号６－２に相当する受信波には、１ｍｓの休止区間が表れている。 FIG. 31 is a graph showing an example of a received wave output by the receiving circuit 11 of the obstacle detection device 16-1 according to the fourth embodiment. The horizontal axis of the graph is the propagation time with the transmission start time of the ultrasonic wave transmitting element 5 as 0 ms, and the vertical axis is the voltage value. The received wave output by the receiving circuit 11 includes the own terminal signal 6-1 and the other terminal signal 6-2. Of the received waves corresponding to the own terminal signal 6-1, the received wave having the shortest propagation time is reflected by the obstacle 7d, and the received wave having the second shortest propagation time is reflected by the obstacle 7e. The received wave with the longest propagation time is the one reflected by the obstacle 7f. Among the received waves corresponding to the other terminal signal 6-2, the received wave having the shortest propagation time is reflected by the obstacle 7d, and the received wave having the second shortest propagation time is reflected by the obstacle 7e. The received wave with the longest propagation time is the one reflected by the obstacle 7f. In the received wave corresponding to the other terminal signal 6-2, a pause section of 1 ms appears.
　図３２は、実施の形態４の自端末信号検出部１８－１において計算される相関関数の値と受信電力の例を示すグラフである。グラフの横軸は伝播時間、縦軸は相関関数の値（実線）と受信電力（破線）である。図３１に示される整形前の受信電圧と、図３２に示される整形後の受信電力とを比較すると、他端末信号６－２に相当する受信波の強度が低下している。そのため、他端末信号６－２が障害物候補位置として検出されにくくなり、誤検出が抑制される。 FIG. 32 is a graph showing an example of the value of the correlation function and the received power calculated by the local terminal signal detection unit 18-1 of the fourth embodiment. The horizontal axis of the graph is the propagation time, and the vertical axis is the value of the correlation function (solid line) and the received power (broken line). Comparing the received voltage before shaping shown in FIG. 31 with the received power after shaping shown in FIG. 32, the intensity of the received wave corresponding to the other terminal signal 6-2 is reduced. Therefore, the other terminal signal 6-2 is less likely to be detected as an obstacle candidate position, and erroneous detection is suppressed.
　図３３は、実施の形態４の自端末信号検出部１８－１において計算される受信電力に対する相関関数の割合の例を示すグラフである。グラフの横軸は伝播時間、縦軸は受信電力に対する相関関数の割合である。図３３に示されるように、自端末信号６－１の反射位置以外の部分では、受信電力に対する相関関数の値が閾値ＴＨ３未満であるため、抽出部１４ａ－１は、自端末信号６－１と他端末信号６－２とを正しく識別できる。 FIG. 33 is a graph showing an example of the ratio of the correlation function to the received power calculated by the local terminal signal detection unit 18-1 of the fourth embodiment. The horizontal axis of the graph is the propagation time, and the vertical axis is the ratio of the correlation function to the received power. As shown in FIG. 33, since the value of the correlation function with respect to the received power is less than the threshold value TH3 in the portion other than the reflection position of the own terminal signal 6-1, the extraction unit 14a-1 uses the own terminal signal 6-1. And the other terminal signal 6-2 can be correctly distinguished.
　図３４は、実施の形態４の他端末信号検出部１８－２において計算される相関関数の値と受信電力の例を示すグラフである。グラフの横軸は伝播時間、縦軸は相関関数の値（実線）と受信電力（破線）である。抽出部１４ａ－２は、図３２に示される整形前の受信電圧と、図３４に示される整形後の受信電力とを比較すると、自端末信号６－１に相当する受信波の強度が低下している。そのため、自端末信号６－１が障害物候補位置として検出されにくくなり、誤検出が抑制される。 FIG. 34 is a graph showing an example of the value of the correlation function and the received power calculated by the other terminal signal detection unit 18-2 of the fourth embodiment. The horizontal axis of the graph is the propagation time, and the vertical axis is the value of the correlation function (solid line) and the received power (broken line). When the extraction unit 14a-2 compares the received voltage before shaping shown in FIG. 32 with the received power after shaping shown in FIG. 34, the intensity of the received wave corresponding to the own terminal signal 6-1 decreases. ing. Therefore, the own terminal signal 6-1 is less likely to be detected as an obstacle candidate position, and erroneous detection is suppressed.
　図３５は、実施の形態４の他端末信号検出部１８－２において計算される受信電力に対する相関関数の割合の例を示すグラフである。グラフの横軸は伝播時間、縦軸は受信電力に対する相関関数の割合である。図３５に示されるように、他端末信号６－２の反射位置以外の部分では、受信電力に対する相関関数の値が閾値ＴＨ３未満であるため、抽出部１４ａ－２は、自端末信号６－１と他端末信号６－２とを正しく識別できる。 FIG. 35 is a graph showing an example of the ratio of the correlation function to the received power calculated by the other terminal signal detection unit 18-2 of the fourth embodiment. The horizontal axis of the graph is the propagation time, and the vertical axis is the ratio of the correlation function to the received power. As shown in FIG. 35, since the value of the correlation function with respect to the received power is less than the threshold value TH3 in the portion other than the reflection position of the other terminal signal 6-2, the extraction unit 14a-2 uses the own terminal signal 6-1. And the other terminal signal 6-2 can be correctly distinguished.
　以上のように、実施の形態４によれば、２組の送信波と変形送信波のうちの一方の組（つまり他端末信号６－２）は、送信波と変形送信波との間に休止区間が設けられている。障害物検出装置１６－１，１６－２は、休止区間のない自端末信号６－１と休止区間のある他端末信号６－２とを識別できるので、自端末信号６－１と他端末信号６－２との多重化が可能である。 As described above, according to the fourth embodiment, one set of the two sets of transmitted waves and the modified transmitted wave (that is, the other terminal signal 6-2) is paused between the transmitted wave and the modified transmitted wave. There is a section. Since the obstacle detection devices 16-1 and 16-2 can distinguish between the own terminal signal 6-1 without a pause section and the other terminal signal 6-2 with a pause section, the own terminal signal 6-1 and the other terminal signal Multiplexing with 6-2 is possible.
　なお、実施の形態４においては休止区間が１ｍｓに設定されているが、この休止区間を変えた送信波と変形送信波とを複数組用いることにより、さらに多くの超音波を多重化することが可能となる。 In the fourth embodiment, the pause section is set to 1 ms, but by using a plurality of sets of the transmission wave and the modified transmission wave in which the pause section is changed, more ultrasonic waves can be multiplexed. It will be possible.
実施の形態５．
　実施の形態５では、超音波送信素子５は、実施の形態１～４のいずれかで使用された送信波と変形送信波とに加え、この送信波よりも短い送信波（以下、「近距離探索波」と称する）を送信する。近距離探索波は、例えば、１波の短パルスである。 Embodiment 5.
In the fifth embodiment, in addition to the transmitted wave and the modified transmitted wave used in any one of the first to fourth embodiments, the ultrasonic transmitting element 5 has a transmitted wave shorter than this transmitted wave (hereinafter, "short distance"). (Called a search wave) is transmitted. The short-range search wave is, for example, a short pulse of one wave.
　車載用に広く使われている圧電セラミックスは、印加される電圧に対し音圧が追従する速度が遅いため、異なる周波数の超音波を送信する場合、周波数変更時の音圧の追従に１０～２５波程度の時間がかかる。つまり、超音波送信素子５から送信される超音波の振幅が最大になるまでに１０～２５波程度の時間がかかる。また、超音波の受信時、超音波受信素子１０から出力される電圧が、印加される音圧に追従するまでにも、１０～２５波程度の時間がかかる。そのため、自車信号６は、２０～５０波程度必要である。図３Ａに示される自車信号６は、送信波２４波及び変形送信波２４波の合計４８波で構成されている。 Piezoelectric ceramics, which are widely used in vehicles, have a slow speed at which the sound pressure follows the applied voltage. Therefore, when transmitting ultrasonic waves of different frequencies, the sound pressure follows the sound pressure when the frequency is changed by 10 to 25. It takes about the time of a wave. That is, it takes about 10 to 25 waves for the amplitude of the ultrasonic wave transmitted from the ultrasonic wave transmitting element 5 to be maximized. Further, when receiving ultrasonic waves, it takes about 10 to 25 waves for the voltage output from the ultrasonic wave receiving element 10 to follow the applied sound pressure. Therefore, the own vehicle signal 6 requires about 20 to 50 waves. The own vehicle signal 6 shown in FIG. 3A is composed of 24 transmitted waves and 24 modified transmitted waves, for a total of 48 waves.
　ところで、１つの超音波素子が超音波送信素子５と超音波受信素子１０とを兼ねる場合、この超音波素子は、２０～５０波の自車信号６を送信している間、自車信号エコー８を受信することができない。そのため、障害物検出装置１６は、伝播時間の短い近距離に存在する障害物７を検出することが困難になる。そこで、実施の形態５に係る障害物検出装置１６は、送信波と変形送信波とに加え、近距離探索波を送信し、近距離に存在する障害物７を検出可能にする。 By the way, when one ultrasonic element also serves as the ultrasonic transmitting element 5 and the ultrasonic receiving element 10, the ultrasonic element echoes the own vehicle signal while transmitting the own vehicle signal 6 of 20 to 50 waves. 8 cannot be received. Therefore, it becomes difficult for the obstacle detection device 16 to detect the obstacle 7 existing at a short distance with a short propagation time. Therefore, the obstacle detection device 16 according to the fifth embodiment transmits a short-distance search wave in addition to the transmission wave and the modified transmission wave to enable detection of the obstacle 7 existing at a short distance.
　図３６は、実施の形態５に係る障害物検出装置１６の構成例を示すブロック図である。実施の形態５に係る障害物検出装置１６は、図１に示された実施の形態１の障害物検出装置１６における超音波送信素子５と超音波受信素子１０とに代えて、超音波素子１９を備える構成である。図３６において図１と同一又は相当する部分は、同一の符号を付し説明を省略する。 FIG. 36 is a block diagram showing a configuration example of the obstacle detection device 16 according to the fifth embodiment. The obstacle detecting device 16 according to the fifth embodiment replaces the ultrasonic transmitting element 5 and the ultrasonic receiving element 10 in the obstacle detecting device 16 of the first embodiment shown in FIG. 1, and the ultrasonic element 19 is used. It is a configuration including. In FIG. 36, the same or corresponding parts as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.
　送信波生成部１ｂは、１波の短パルス等の近距離探索波を生成し、生成した近距離探索波を送信回路４ｂへ出力する。送信回路４ｂは、近距離探索波を超音波素子１９に印加できる電圧へと変換し、超音波素子１９は、近距離探索波を送受信する。例えば、超音波素子１９は、まず近距離探索波を送信し、その５ｍｓ後に送信波と変形送信波とを送信する。 The transmission wave generation unit 1b generates a short-range search wave such as a short pulse of one wave, and outputs the generated short-range search wave to the transmission circuit 4b. The transmission circuit 4b converts the short-range search wave into a voltage that can be applied to the ultrasonic element 19, and the ultrasonic element 19 transmits and receives the short-range search wave. For example, the ultrasonic element 19 first transmits a short-range search wave, and 5 ms later, transmits a transmission wave and a modified transmission wave.
　受信回路１１ｂは、近距離探索波を受信した受信波を抽出部１４ｂへ出力する。抽出部１４ｂは、受信波に含まれる近距離探索波を抽出し、抽出した近距離探索波の伝播時間を出力する。抽出部１４ｂは、例えば、予め定められた閾値と受信波の強度とを比較し、受信波の強度が閾値以上である場合に近距離探索波として抽出する。このように、障害物検出装置１６は、近距離探索波については、整形部１２による整形処理及び相関関数演算部１３による相関関数演算処理を行わない。 The receiving circuit 11b outputs the received wave that has received the short-range search wave to the extraction unit 14b. The extraction unit 14b extracts the short-range search wave included in the received wave and outputs the propagation time of the extracted short-range search wave. For example, the extraction unit 14b compares a predetermined threshold value with the intensity of the received wave, and extracts as a short-distance search wave when the intensity of the received wave is equal to or higher than the threshold value. As described above, the obstacle detection device 16 does not perform the shaping process by the shaping unit 12 and the correlation function calculation processing by the correlation function calculation unit 13 for the short-distance search wave.
　以上のように、実施の形態５によれば、超音波素子１９は、送信波と変形送信波とに加え、この送信波よりも短い近距離探索波を送信する。この構成により、障害物検出装置１６は、送信波と変形送信波とを用いて遠距離の障害物を検出し、近距離探索波を用いて近距離の障害物を検出することができる。 As described above, according to the fifth embodiment, the ultrasonic element 19 transmits a short-range search wave shorter than this transmitted wave in addition to the transmitted wave and the deformed transmitted wave. With this configuration, the obstacle detection device 16 can detect a long-distance obstacle using a transmitted wave and a modified transmitted wave, and can detect a short-distance obstacle using a short-distance search wave.
　なお、実施の形態５では、近距離探索波を送信する機能を、送受信用の超音波素子１９を１つ備えた障害物検出装置１６に対して適用した例を示したが、超音波送信素子５と超音波受信素子１０とを備えた障害物検出装置１６に対して適用してもよい。
　また、実施の形態５では、近距離探索波を送信する機能を実施の形態１に係る障害物検出装置１６に対して適用した例を示したが、この機能を実施の形態２に係る障害物検出装置１６、及び実施の形態３，４に係る障害物検出装置１６－１，１６－２に対して適用してもよい。 In the fifth embodiment, an example in which the function of transmitting a short-range search wave is applied to an obstacle detection device 16 provided with one ultrasonic element 19 for transmission / reception is shown, but the ultrasonic transmission element It may be applied to the obstacle detection device 16 including the 5 and the ultrasonic wave receiving element 10.
Further, in the fifth embodiment, an example in which the function of transmitting the short-distance search wave is applied to the obstacle detection device 16 according to the first embodiment is shown, but this function is applied to the obstacle detection device 16 according to the second embodiment. It may be applied to the detection device 16 and the obstacle detection devices 16-1 and 16-2 according to the third and fourth embodiments.
　最後に、各実施の形態に係る障害物検出装置１６，１６－１，１６－２のハードウェア構成を説明する。
　図３７及び図３８は、各実施の形態に係る障害物検出装置１６，１６－１，１６－２のハードウェア構成例を示す図である。障害物検出装置１６，１６－１，１６－２における送信波生成部１，１ｂ、変形内容設定部２、送信波変形部３、整形部１２，１２ａ，１２ａ－１，１２ａ－２、相関関数演算部１３，１３－１，１３－２、抽出部１４，１４ａ，１４ａ－１，１４ａ－２，１４ｂの機能は、処理回路により実現される。即ち、障害物検出装置１６，１６－１，１６－２は、上記機能を実現するための処理回路を備える。処理回路は、専用のハードウェアとしての処理回路１００であってもよいし、メモリ１０２に格納されるプログラムを実行するプロセッサ１０１であってもよい。 Finally, the hardware configurations of the obstacle detection devices 16, 16-1, 16-2 according to each embodiment will be described.
37 and 38 are diagrams showing a hardware configuration example of the obstacle detection devices 16, 16-1, 16-2 according to each embodiment. Transmission wave generation unit 1, 1b, deformation content setting unit 2, transmission wave deformation unit 3, shaping unit 12, 12a, 12a-1, 12a-2, correlation function in obstacle detection devices 16, 16-1, 16-2 The functions of the arithmetic units 13, 13-1, 13-2 and the extraction units 14, 14a, 14a-1, 14a-2, 14b are realized by the processing circuit. That is, the obstacle detection devices 16, 16-1, 16-2 are provided with a processing circuit for realizing the above functions. The processing circuit may be a processing circuit 100 as dedicated hardware, or a processor 101 that executes a program stored in the memory 102.
　図３７に示されるように、処理回路が専用のハードウェアである場合、処理回路１００は、例えば、単一回路、複合回路、プログラム化したプロセッサ、並列プログラム化したプロセッサ、ＡＳＩＣ（Ａｐｐｌｉｃａｔｉｏｎ　Ｓｐｅｃｉｆｉｃ　Ｉｎｔｅｇｒａｔｅｄ　Ｃｉｒｃｕｉｔ）、ＦＰＧＡ（Ｆｉｅｌｄ　Ｐｒｏｇｒａｍｍａｂｌｅ　Ｇａｔｅ　Ａｒｒａｙ）、又はこれらを組み合わせたものが該当する。送信波生成部１，１ｂ、変形内容設定部２、送信波変形部３、整形部１２，１２ａ，１２ａ－１，１２ａ－２、相関関数演算部１３，１３－１，１３－２、抽出部１４，１４ａ，１４ａ－１，１４ａ－２，１４ｂの機能を複数の処理回路１００で実現してもよいし、各部の機能をまとめて１つの処理回路１００で実現してもよい。 As shown in FIG. 37, when the processing circuit is dedicated hardware, the processing circuit 100 may be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, or an ASIC (Application Special Integrated Circuit). ), FPGA (Field Processor Gate Array), or a combination thereof. Transmission wave generation unit 1, 1b, deformation content setting unit 2, transmission wave deformation unit 3, shaping unit 12, 12a, 12a-1, 12a-2, correlation function calculation unit 13, 13-1, 13-2, extraction unit The functions of 14, 14a, 14a-1, 14a-2, and 14b may be realized by a plurality of processing circuits 100, or the functions of each part may be collectively realized by one processing circuit 100.
　図３８に示されるように、処理回路がプロセッサ１０１である場合、送信波生成部１，１ｂ、変形内容設定部２、送信波変形部３、整形部１２，１２ａ，１２ａ－１，１２ａ－２、相関関数演算部１３，１３－１，１３－２、抽出部１４，１４ａ，１４ａ－１，１４ａ－２，１４ｂの機能は、ソフトウェア、ファームウェア、又はソフトウェアとファームウェアとの組み合わせにより実現される。ソフトウェア又はファームウェアはプログラムとして記述され、メモリ１０２に格納される。プロセッサ１０１は、メモリ１０２に格納されたプログラムを読みだして実行することにより、各部の機能を実現する。即ち、障害物検出装置１６，１６－１，１６－２は、プロセッサ１０１により実行されるときに、実施の形態１～５で説明された動作が結果的に実行されることになるプログラムを格納するためのメモリ１０２を備える。また、このプログラムは、送信波生成部１，１ｂ、変形内容設定部２、送信波変形部３、整形部１２，１２ａ，１２ａ－１，１２ａ－２、相関関数演算部１３，１３－１，１３－２、抽出部１４，１４ａ，１４ａ－１，１４ａ－２，１４ｂの手順又は方法をコンピュータに実行させるものであるとも言える。 As shown in FIG. 38, when the processing circuit is the processor 101, the transmission wave generation unit 1, 1b, the deformation content setting unit 2, the transmission wave deformation unit 3, and the shaping unit 12, 12a, 12a-1, 12a-2. , Correlation function calculation unit 13, 13-1, 13-2, extraction unit 14, 14a, 14a-1, 14a-2, 14b functions are realized by software, firmware, or a combination of software and firmware. The software or firmware is described as a program and stored in the memory 102. The processor 101 realizes the functions of each part by reading and executing the program stored in the memory 102. That is, the obstacle detection devices 16, 16-1, 16-2 store a program in which the operations described in the first to fifth embodiments are eventually executed when executed by the processor 101. A memory 102 is provided. Further, this program includes a transmission wave generation unit 1, 1b, a transformation content setting unit 2, a transmission wave deformation unit 3, a shaping unit 12, 12a, 12a-1, 12a-2, a correlation function calculation unit 13, 13-1, It can also be said that the procedure or method of 13-2, extraction units 14, 14a, 14a-1, 14a-2, 14b is executed by a computer.
　ここで、プロセッサ１０１とは、ＣＰＵ（Ｃｅｎｔｒａｌ　Ｐｒｏｃｅｓｓｉｎｇ　Ｕｎｉｔ）、処理装置、演算装置、又はマイクロプロセッサ等のことである。
　メモリ１０２は、ＲＡＭ（Ｒａｎｄｏｍ　Ａｃｃｅｓｓ　Ｍｅｍｏｒｙ）、ＲＯＭ（Ｒｅａｄ　Ｏｎｌｙ　Ｍｅｍｏｒｙ）、ＥＰＲＯＭ（Ｅｒａｓａｂｌｅ　Ｐｒｏｇｒａｍｍａｂｌｅ　ＲＯＭ）、又はフラッシュメモリ等の不揮発性もしくは揮発性の半導体メモリであってもよいし、ハードディスク又はフレキシブルディスク等の磁気ディスクであってもよいし、ＣＤ（Ｃｏｍｐａｃｔ　Ｄｉｓｃ）又はＤＶＤ（Ｄｉｇｉｔａｌ　Ｖｅｒｓａｔｉｌｅ　Ｄｉｓｃ）等の光ディスクであってもよい。 Here, the processor 101 is a CPU (Central Processing Unit), a processing device, an arithmetic unit, a microprocessor, or the like.
The memory 102 may be a non-volatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), an EPROM (Erasable Programmable ROM), or a flash memory, or may be a non-volatile or volatile semiconductor memory such as a hard disk or a flexible disk. It may be a magnetic disk of the above, or an optical disk such as a CD (Compact Disc) or a DVD (Digital Versaille Disc).
　なお、送信波生成部１，１ｂ、変形内容設定部２、送信波変形部３、整形部１２，１２ａ，１２ａ－１，１２ａ－２、相関関数演算部１３，１３－１，１３－２、抽出部１４，１４ａ，１４ａ－１，１４ａ－２，１４ｂの機能について、一部を専用のハードウェアで実現し、一部をソフトウェア又はファームウェアで実現するようにしてもよい。このように、障害物検出装置１６，１６－１，１６－２における処理回路は、ハードウェア、ソフトウェア、ファームウェア、又はこれらの組み合わせによって、上述の機能を実現することができる。 The transmission wave generation unit 1, 1b, the transformation content setting unit 2, the transmission wave deformation unit 3, the shaping unit 12, 12a, 12a-1, 12a-2, the correlation function calculation unit 13, 13-1, 13-2, Some of the functions of the extraction units 14, 14a, 14a-1, 14a-2, and 14b may be realized by dedicated hardware, and some may be realized by software or firmware. As described above, the processing circuits in the obstacle detection devices 16, 16-1, 16-2 can realize the above-mentioned functions by hardware, software, firmware, or a combination thereof.
　本発明はその発明の範囲内において、各実施の形態の自由な組み合わせ、各実施の形態の任意の構成要素の変形、又は各実施の形態の任意の構成要素の省略が可能である。 The present invention allows any combination of embodiments, modifications of any component of each embodiment, or omission of any component of each embodiment within the scope of the invention.
　この発明に係る障害物検出装置は、複数の超音波信号を識別するようにしたので、車両の自動駐車及び自動運転等を行う運転制御装置等に用いられる障害物検出装置に適している。 Since the obstacle detection device according to the present invention is designed to identify a plurality of ultrasonic signals, it is suitable for an obstacle detection device used in an operation control device or the like that automatically parks and drives a vehicle.
　１，１ｂ　送信波生成部、２　変形内容設定部、３　送信波変形部、４，４ｂ　送信回路、５　超音波送信素子、６　自車信号、６－１　自端末信号、６－２　他端末信号、７，７ａ，７ｂ，７ｃ，７ｄ，７ｅ，７ｆ　障害物、８　自車信号エコー、９　他車信号、１０　超音波受信素子、１１，１１ｂ　受信回路、１２，１２ａ，１２ａ－１，１２ａ－２　整形部、１３，１３－１，１３－２　相関関数演算部、１４，１４ａ，１４ａ－１，１４ａ－２，１４ｂ　抽出部、１５　送受信部、１６，１６－１，１６－２　障害物検出装置、１７　自車、１８－１　自端末信号検出部、１８－２　他端末信号検出部、１９　超音波素子、１００　処理回路、１０１　プロセッサ、１０２　メモリ、１２０１　検波部、１２１１　ハイパスフィルタ、１２１２　時間シフト部、１２１３　周波数シフト部、１２２１　ローパスフィルタ、１４０１　受信電力計算部、１４０２　比較部、１４１１　障害物候補位置検出部。 1,1b transmission wave generator, 2 deformation content setting unit, 3 transmission wave deformation part, 4,4b transmission circuit, 5 ultrasonic transmission element, 6 own vehicle signal, 6-1 own terminal signal, 6-2 other terminal signal , 7, 7a, 7b, 7c, 7d, 7e, 7f Obstacles, 8 own vehicle signal echo, 9 other vehicle signal, 10 ultrasonic receiving element, 11, 11b receiving circuit, 12, 12a, 12a-1, 12a- 2 Shaping unit, 13, 13-1, 13-2 Correlation function calculation unit, 14, 14a, 14a-1, 14a-2, 14b Extraction unit, 15 Transmission / reception unit, 16, 16-1, 16-2 Obstacle detection Equipment, 17 own vehicle, 18-1 own terminal signal detection unit, 18-2 other terminal signal detection unit, 19 ultrasonic element, 100 processing circuit, 101 processor, 102 memory, 1201 detection unit, 1211 high-pass filter, 1212 time shift Unit, 1213 frequency shift unit, 1221 low-pass filter, 1401 received power calculation unit, 1402 comparison unit, 1411 obstacle candidate position detection unit.

Claims (10)

  1. 　送信波を生成する送信波生成部と、
    　前記送信波を分割又は複製し変形した変形送信波を生成する送信波変形部と、
    　超音波素子を有し、前記送信波と前記変形送信波とを超音波として送信し、障害物で反射した前記超音波を受信して受信波を出力する送受信部と、
    　前記送信波変形部の変形内容に基づいて前記受信波を整形した整形受信波を生成する整形部と、
    　前記受信波と前記整形受信波との相関関数を演算する相関関数演算部と、
    　前記相関関数演算部により演算された相関関数に基づいて、前記受信波の中から前記送信波に相当する成分を抽出する抽出部とを備える障害物検出装置。     A transmission wave generator that generates a transmission wave and
    A transmission wave deformation unit that divides or duplicates the transmission wave to generate a deformed transmission wave, and
    A transmitter / receiver having an ultrasonic element, transmitting the transmitted wave and the deformed transmitted wave as ultrasonic waves, receiving the ultrasonic waves reflected by an obstacle, and outputting the received waves.
    A shaping unit that generates a shaping reception wave that shapes the reception wave based on the deformation content of the transmission wave deformation part, and a shaping unit.
    A correlation function calculation unit that calculates a correlation function between the received wave and the shaped received wave,
    An obstacle detection device including an extraction unit that extracts a component corresponding to the transmission wave from the received wave based on the correlation function calculated by the correlation function calculation unit.
  2. 　前記送信波変形部は、前記送信波の周波数又は時間の少なくとも一方をシフトさせた前記変形送信波を生成することを特徴とする請求項１記載の障害物検出装置。 The obstacle detection device according to claim 1, wherein the transmitted wave deforming unit generates the deformed transmitted wave in which at least one of the frequency and the time of the transmitted wave is shifted.
  3. 　前記送信波変形部は、前記送信波の周波数及び時間の双方をシフトさせた前記変形送信波を生成することを特徴とする請求項２記載の障害物検出装置。 The obstacle detection device according to claim 2, wherein the transmitted wave deforming unit generates the deformed transmitted wave in which both the frequency and the time of the transmitted wave are shifted.
  4. 　前記整形部は、前記受信波の周波数及び時間の双方をシフトさせることを特徴とする請求項３記載の障害物検出装置。 The obstacle detection device according to claim 3, wherein the shaping unit shifts both the frequency and time of the received wave.
  5. 　前記抽出部は、前記相関関数の値が前記受信波の強度に対して予め定められた割合以上である場合に前記送信波に相当する成分として抽出することを特徴とする請求項１記載の障害物検出装置。 The obstacle according to claim 1, wherein the extraction unit extracts as a component corresponding to the transmitted wave when the value of the correlation function is equal to or more than a predetermined ratio with respect to the intensity of the received wave. Object detector.
  6. 　前記送信波変形部は、前記送信波と前記変形送信波とを１組とし、波形の異なる２組以上の前記送信波と前記変形送信波とを出力することを特徴とする請求項１記載の障害物検出装置。 The first aspect of the present invention, wherein the transmission wave deformation unit has the transmission wave and the deformation transmission wave as one set, and outputs two or more sets of the transmission wave and the deformation transmission wave having different waveforms. Obstacle detector.
  7. 　前記送信波の周波数と前記変形送信波の周波数とは、前記超音波素子の固有振動数を中心に対称の関係にあることを特徴とする請求項６記載の障害物検出装置。 The obstacle detection device according to claim 6, wherein the frequency of the transmitted wave and the frequency of the modified transmitted wave have a symmetrical relationship with respect to the natural frequency of the ultrasonic element.
  8. 　前記送信波の周波数と前記変形送信波の周波数とは、前記超音波素子の固有振動数からシフトした周波数を中心に対称の関係にあることを特徴とする請求項６記載の障害物検出装置。 The obstacle detection device according to claim 6, wherein the frequency of the transmitted wave and the frequency of the modified transmitted wave have a symmetrical relationship with respect to a frequency shifted from the natural frequency of the ultrasonic element.
  9. 　前記２組の前記送信波と前記変形送信波のうちの一方の組は、前記送信波と前記変形送信波との間に休止区間が設けられたものであることを特徴とする請求項６記載の障害物検出装置。 6. The sixth aspect of claim 6, wherein one set of the two sets of the transmitted wave and the modified transmitted wave is provided with a pause section between the transmitted wave and the modified transmitted wave. Obstacle detector.
  10. 　前記超音波素子は、前記送信波と前記変形送信波とに加え、前記送信波よりも短い送信波を送信することを特徴とする請求項１記載の障害物検出装置。 The obstacle detection device according to claim 1, wherein the ultrasonic element transmits a transmission wave shorter than the transmission wave in addition to the transmission wave and the modified transmission wave.
PCT/JP2019/015453 2019-04-09 2019-04-09 Obstacle detection device WO2020208705A1 (en)

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Citations (5)

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Publication number Priority date Publication date Assignee Title
JPS6128108B2 (en) * 1977-12-13 1986-06-28 Japan Radio Co Ltd
JPH06174842A (en) * 1992-12-10 1994-06-24 Nec Eng Ltd Active sonar
JPH08114672A (en) * 1994-10-18 1996-05-07 Nec Eng Ltd Active sonar
JP2014025914A (en) * 2012-06-21 2014-02-06 Furuno Electric Co Ltd Target detection device and target detection method
US20150078130A1 (en) * 2013-09-17 2015-03-19 Volkswagen Aktiengesellschaft Device and method for lateral environment detection of a motor vehicle

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6128108B2 (en) * 1977-12-13 1986-06-28 Japan Radio Co Ltd
JPH06174842A (en) * 1992-12-10 1994-06-24 Nec Eng Ltd Active sonar
JPH08114672A (en) * 1994-10-18 1996-05-07 Nec Eng Ltd Active sonar
JP2014025914A (en) * 2012-06-21 2014-02-06 Furuno Electric Co Ltd Target detection device and target detection method
US20150078130A1 (en) * 2013-09-17 2015-03-19 Volkswagen Aktiengesellschaft Device and method for lateral environment detection of a motor vehicle

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