WO2020208705A1 - Dispositif de détection d'obstacle - Google Patents

Dispositif de détection d'obstacle 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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English (en)
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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Priority to PCT/JP2019/015453 priority Critical patent/WO2020208705A1/fr
Publication of WO2020208705A1 publication Critical patent/WO2020208705A1/fr

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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.

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

Abstract

L'invention concerne une unité (3) de déformation d'onde d'émission qui génère une onde d'émission déformée obtenue par division ou reproduction, et déformation, d'une onde d'émission générée par une unité (1) de génération d'onde d'émission. Une unité d'émission/réception (15) émet une onde d'émission et l'onde d'émission déformée en tant que signal (6) de véhicule hôte, reçoit un écho (8) de signal d'hôte réfléchi par un obstacle (7), et émet une onde de réception. Une unité (12) de mise en forme génère une onde de réception façonnée obtenue par mise en forme de l'onde de réception sur la base du contenu de déformation par l'unité (3) de déformation d'onde d'émission. Une unité (13) de calcul de fonction de corrélation calcule une fonction de corrélation de l'onde de réception et de l'onde de réception façonnée. Une unité d'extraction (14) extrait une composante correspondant au signal (6) de véhicule hôte à partir de l'onde de réception sur la base de la fonction de corrélation calculée par l'unité (13) de calcul de fonction de corrélation.
PCT/JP2019/015453 2019-04-09 2019-04-09 Dispositif de détection d'obstacle WO2020208705A1 (fr)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6128108B2 (fr) * 1977-12-13 1986-06-28 Japan Radio Co Ltd
JPH06174842A (ja) * 1992-12-10 1994-06-24 Nec Eng Ltd アクティブソナー装置
JPH08114672A (ja) * 1994-10-18 1996-05-07 Nec Eng Ltd アクティブソーナー装置
JP2014025914A (ja) * 2012-06-21 2014-02-06 Furuno Electric Co Ltd 物標探知装置および物標探知方法
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 (fr) * 1977-12-13 1986-06-28 Japan Radio Co Ltd
JPH06174842A (ja) * 1992-12-10 1994-06-24 Nec Eng Ltd アクティブソナー装置
JPH08114672A (ja) * 1994-10-18 1996-05-07 Nec Eng Ltd アクティブソーナー装置
JP2014025914A (ja) * 2012-06-21 2014-02-06 Furuno Electric Co Ltd 物標探知装置および物標探知方法
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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