WO2017141370A1 - Appareil de détection d'objet, procédé de détection d'objet, et programme de détection d'objet - Google Patents

Appareil de détection d'objet, procédé de détection d'objet, et programme de détection d'objet Download PDF

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Publication number
WO2017141370A1
WO2017141370A1 PCT/JP2016/054543 JP2016054543W WO2017141370A1 WO 2017141370 A1 WO2017141370 A1 WO 2017141370A1 JP 2016054543 W JP2016054543 W JP 2016054543W WO 2017141370 A1 WO2017141370 A1 WO 2017141370A1
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Prior art keywords
signal
moving body
acoustic signal
unit
distance
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PCT/JP2016/054543
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English (en)
Japanese (ja)
Inventor
健太郎 石川
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三菱電機株式会社
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Priority to PCT/JP2016/054543 priority Critical patent/WO2017141370A1/fr
Priority to JP2016568980A priority patent/JPWO2017141370A1/ja
Publication of WO2017141370A1 publication Critical patent/WO2017141370A1/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
    • 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
    • G01S15/50—Systems of measurement, based on relative movement of the target
    • G01S15/58—Velocity or trajectory determination systems; Sense-of-movement determination systems
    • G01S15/60—Velocity or trajectory determination systems; Sense-of-movement determination systems wherein the transmitter and receiver are mounted on the moving object, e.g. for determining ground speed, drift angle, ground track

Definitions

  • This invention relates to a technique for detecting an object existing around a moving body.
  • a technique for detecting an object existing around a moving body for example, there is a technique for detecting surrounding vehicles existing around the vehicle. By detecting an object around the moving body, it is possible to control the moving body so as to avoid a collision with the detected object.
  • Patent Document 1 describes that an object is detected using an ultrasonic sensor.
  • An object of the present invention is to make it possible to accurately detect an object using an acoustic signal even when a Doppler shift occurs.
  • the object detection device is: A reception unit that receives a reflected wave signal generated by reflecting an acoustic signal radiated from a moving object, which is an acoustic signal composed of a plurality of waves having different frequencies, And a detection unit that detects the object by calculating a correlation value between the reception signal and a reference signal using the reflected wave signal received by the reception unit as a reception signal.
  • an object is detected using an acoustic signal formed by superposing a plurality of waves having different frequencies. Therefore, even if a Doppler shift occurs, an object can be detected with high accuracy.
  • FIG. 3 is an explanatory diagram of a situation between the moving body 100 according to the first embodiment and the object 200 existing around the moving body 100.
  • 3 is a flowchart showing an overall operation of the object detection apparatus 10 according to the first embodiment.
  • 5 is a flowchart showing the operation of step ST1 according to the first embodiment.
  • FIG. 6 Explanatory drawing of the transmission signal generation method which concerns on Embodiment 1.
  • FIG. 6 is a flowchart showing the operation of step ST2 according to the first embodiment. 6 is a flowchart showing the operation of step ST3 according to the first embodiment.
  • FIG. 10 is a flowchart showing the operation of step ST2 according to the second embodiment.
  • FIG. 10 is a flowchart showing the operation of step ST3 according to the second embodiment.
  • FIG. 6 is a configuration diagram of an object detection device 10 according to a third embodiment. Explanatory drawing of the condition of the mobile body 100 which concerns on Embodiment 3, and the object 200 which exists around the mobile body 100.
  • FIG. 10 is a flowchart showing the operation of step ST1 according to the third embodiment.
  • 10 is a flowchart showing the operation of step ST3 according to the third embodiment.
  • FIG. 6 is a configuration diagram of an object detection apparatus 10 according to a fourth embodiment. 10 is a flowchart showing an overall operation of the object detection apparatus 10 according to the fourth embodiment.
  • Embodiment 1 FIG. *** Explanation of configuration *** With reference to FIG. 1, an example in which the object detection apparatus 10 according to Embodiment 1 is mounted on a moving body will be described.
  • the object detection device 10 is a computer mounted on the moving body 100.
  • the moving body 100 is a vehicle.
  • the moving body 100 may be another type such as a ship.
  • a mounting form for mounting the object detection device 10 it is mounted in a removable or separable form even if it is integrated with the moving body 100 or other illustrated components in a form that is integrated or inseparable. May be.
  • the object detection device 10 includes hardware including a processor 11, a storage device 12, an audio interface 13, and an in-vehicle interface 14.
  • the processor 11 is connected to other hardware via the system bus and controls these other hardware.
  • the processor 11 is an IC (Integrated Circuit) that performs processing. Specific examples of the processor 11 are a CPU (Central Processing Unit), a DSP (Digital Signal Processor), and a GPU (Graphics Processing Unit).
  • a CPU Central Processing Unit
  • DSP Digital Signal Processor
  • GPU Graphics Processing Unit
  • the storage device 12 includes a memory 121 and a storage 122.
  • the memory 121 is, for example, a RAM (Random Access Memory).
  • the storage 122 is an HDD (Hard Disk Drive) as a specific example.
  • the storage 122 may be a portable storage medium such as an SD (Secure Digital) memory card, a CF (CompactFlash), a NAND flash, a flexible disk, an optical disk, a compact disk, a Blu-ray (registered trademark) disk, or a DVD.
  • SD Secure Digital
  • CF CompactFlash
  • NAND flash NAND flash
  • the audio interface 13 is a device for connecting the acoustic signal output device 21 and the acoustic signal input device 22 mounted on the moving body 100 to the system bus via the audio bus.
  • the audio interface 13 is a USB (Universal Serial Bus), IEEE 1394, or HDMI (registered trademark, High-Definition Multimedia Interface) terminal.
  • the acoustic signal output device 21 is a device that outputs an acoustic signal.
  • the acoustic signal output device 21 is a device including a D / A (digital / analog) converter, a signal amplifier, and a radiation device.
  • the D / A converter is a device that converts a digital signal including transmission signal waveform information transmitted from the audio interface 13 via the audio bus into an analog signal that is an electrical signal.
  • the signal amplifier is a device that amplifies the transmission signal converted into an analog signal by the D / A converter.
  • the radiation device is a device that radiates a transmission signal, which is an analog signal amplified by a signal amplifier, as an acoustic signal.
  • the radiation device is a speaker.
  • the radiating device is not limited to a speaker, but may be a device that can radiate an analog signal having a plurality of frequency peaks.
  • the radiating device may be a device in which a plurality of ultrasonic sensors having different resonance frequencies are assembled.
  • the acoustic signal input device 22 is a device that collects an acoustic signal including a reflected wave reflected by an object from the acoustic signal radiated from the acoustic signal output device 21.
  • the acoustic signal input device 22 is a device including a collection device, a signal amplifier, and an A / D (analog / digital) converter.
  • the collection device is a device that converts an acoustic signal from the outside of the device into an analog signal that is an electrical signal and collects the signal.
  • the signal amplifier is a device that amplifies the analog signal collected by the collecting device.
  • the A / D converter is a device that converts the analog signal amplified by the signal amplifier into a digital signal including received signal waveform information and transmits the digital signal to the audio interface 13 via the audio bus.
  • the collection device is a microphone as a specific example.
  • the collecting device is not limited to a microphone, but may be any device that can collect acoustic signals having a plurality of frequency peaks.
  • the collecting device may be a device in which a plurality of ultrasonic sensors having different resonance frequencies are assembled.
  • the in-vehicle interface 14 is a device for connecting the vehicle information ECU 23 and the sensor ECU 24 mounted on the moving body 100 to the system bus via the in-vehicle bus.
  • the in-vehicle interface 14 is, as a specific example, a USB, IEEE 1394, or HDMI (registered trademark) terminal.
  • the in-vehicle bus is, as a specific example, a CAN (Control Area Network).
  • the vehicle information ECU 23 is a device that acquires information such as time and the speed of the moving body 100.
  • the sensor ECU 24 is a device that acquires external environment information, which is information about the environment outside the moving body 100 such as temperature and wind speed. External environment information is used to correct the acoustic velocity V s. Therefore, temperatures as external environment information is not limited to wind speed, humidity, atmospheric pressure, specific heat, may be any parameters available for the correction of density such acoustic velocity V s.
  • the object detection device 10 includes, as functional components, a time synchronization unit 111, a transmission signal generation unit 112, a reception signal generation unit 113, a vehicle signal generation unit 114, an environmental signal generation unit 115, a detection unit 116, A radiation unit 131, a reception unit 132, a time acquisition unit 141, a vehicle information acquisition unit 142, and an environment information acquisition unit 143 are provided.
  • the functions of the time synchronization unit 111, the transmission signal generation unit 112, the reception signal generation unit 113, the vehicle signal generation unit 114, the environment signal generation unit 115, and the detection unit 116 are realized by software.
  • the storage 122 of the storage device 12 stores a program that realizes the function of each unit realized by software.
  • This program is read into the memory 121 by the processor 11 and executed by the processor 11.
  • the functions of the radiation unit 131 and the reception unit 132 are realized by the audio interface 13.
  • the functions of the time acquisition unit 141, the vehicle information acquisition unit 142, and the environment information acquisition unit 143 are realized by the in-vehicle interface 14.
  • Information, data, signal values, and variable values indicating the results of processing of the functions of the respective units of the object detection device 10 are stored in the memory 121, the register in the processor 11, or the cache memory. In the following description, it is assumed that information, data, signal values, and variable values indicating the processing results of the functions of the respective units of the object detection apparatus 10 are stored in the memory 121.
  • this program may be stored in a portable storage medium such as a magnetic disk, a flexible disk, an optical disk, a compact disk, a Blu-ray (registered trademark) disk, or a DVD.
  • a portable storage medium such as a magnetic disk, a flexible disk, an optical disk, a compact disk, a Blu-ray (registered trademark) disk, or a DVD.
  • FIG. 1 only one processor 11 is shown. However, a plurality of processors 11 may be provided, and a plurality of processors 11 may execute programs that realize each function in cooperation with each other.
  • the operation of the object detection apparatus 10 according to the first embodiment corresponds to the object detection method according to the first embodiment.
  • the operation of the object detection apparatus 10 according to the first embodiment corresponds to the processing of the object detection program according to the first embodiment.
  • the object 200 is a vehicle that travels in front of the moving body 100.
  • FIG. 2 shows a moving body 100 on which an acoustic signal output device 21 and an acoustic signal input device 22 are installed, and an object 200.
  • the acoustic signal output device 21 and the acoustic signal input device 22 are disposed at positions close to each other on the front side of the moving body 100.
  • the shortest path length from the acoustic signal output device 21 to the object 200 and the shortest path length from the reflected wave generation source to the acoustic signal input device 22 are almost equal to the distance d.
  • the generation source of the reflected wave is a position where the transmission signal output from the acoustic signal output device 21 reaches the object 200 in the shortest time.
  • the mobile 100 is traveling at a speed v s
  • the object 200 travels at a speed v o.
  • the time synchronization unit 111 generates a synchronization signal based on the time acquired by the time acquisition unit 141 from the vehicle information ECU 23, and receives the transmission signal generation unit 112 and the reception.
  • the signal is transmitted to the signal generator 113, the vehicle signal generator 114, and the environment signal generator 115.
  • the transmission signal generation unit 112 transmits a transmission signal to the radiation unit 131 every predetermined time T seconds based on the synchronization signal transmitted by the time synchronization unit 111.
  • the radiating unit 131 transmits the received transmission signal to the acoustic signal output device 21.
  • the acoustic signal output device 21 radiates the received transmission signal as an acoustic signal.
  • the reception unit 132 receives a reception signal that is an acoustic signal converted into a digital signal by the acoustic signal input device 22.
  • the acoustic signal (transmission signal) radiated by the acoustic signal output device 21 in step ST1 is reflected by the object 200.
  • the signal component corresponding to the reflected wave generated by is included.
  • the received signal may contain noise other than the signal component corresponding to the reflected wave.
  • the reception signal generation unit 113 transmits the reception signal for the latest T seconds received by the reception unit 132 to the detection unit 116 every fixed time T1 seconds.
  • the time T1 is equal to or less than the time T.
  • the vehicle signal generation unit 114 acquires the speed of the moving body 100 via the vehicle information acquisition unit 142 and transmits it to the detection unit 116.
  • the environment signal generation unit 115 acquires external environment information via the environment information acquisition unit 143 and transmits the external environment information to the detection unit 116.
  • the reception signal generation unit 113, the vehicle signal generation unit 114, and the environment signal generation unit 115 are synchronized with the timing at which transmission of the transmission signal is started in step ST1, based on the synchronization signal transmitted by the time synchronization unit 111. Works.
  • the detection unit 116 detects the object 200 present around the moving body 100 based on the reception signal transmitted by the reception signal generation unit 113 in step ST2. In addition, when the object 200 is detected, the detection unit 116 converts the speed transmitted by the vehicle signal generation unit 114 in step ST2 and the external environment information transmitted by the environment signal generation unit 115 together with the reception signal. Based on this, the relative distance d and the relative speed ⁇ v of the object 200 are estimated.
  • step ST1 ** Detailed operation of step ST1 ** With reference to FIG. 4, the operation of step ST1 according to the first embodiment will be described in detail.
  • the transmission signal generation unit 112 measures the elapsed time from the transmission time at which the previous transmission signal was transmitted, based on the synchronization signal transmitted by the time synchronization unit 111. If T seconds have elapsed from the transmission time, the transmission signal generation unit 112 proceeds to step ST12, and if T seconds have not elapsed from the transmission time, the transmission signal generation unit 112 executes step ST11 again.
  • the transmission signal generation unit 112 reads a signal waveform stored in the memory 121 in advance, and transmits the read signal waveform to the radiation unit 131 as a transmission signal. And the radiation
  • the transmission signal radiated as an acoustic signal is a signal configured by superposing a plurality of waves having different frequencies.
  • the transmission signal is preferably a signal obtained by superposing a plurality of waves whose frequencies increase according to the geometric sequence.
  • the transmission signal is desirably a signal obtained by superposing a plurality of waves having different initial phases for each frequency.
  • the frequency of each wave that is a component of the transmission signal is preferably in the frequency band of sound waves or low-frequency ultrasonic waves, specifically in the range of 16 kHz to 100 kHz. That is, it is desirable that the acoustic signal as the transmission signal is a signal obtained by superimposing a plurality of waves having a frequency within one of the frequency bands of the sound wave and the low frequency ultrasonic wave.
  • the transmission signal includes the first signal and the phase of the first signal. And a second signal obtained by inverting.
  • the transmission signal includes q ( ⁇ 2) types of frequency components, the frequency increases in a geometric series, and the frequency and the initial phase correspond one-to-one.
  • a signal is available. That is, as a specific example, the signal u (t, T 0 ) shown in Equation 1 can be used as the transmission signal.
  • p (> 0) is a constant corresponding to the bandwidth.
  • f 0 (> 0) is a constant representing the lowest frequency.
  • T 0 (> 0) is a constant related to the initial phase.
  • a k is a constant corresponding to the amplitude of each frequency.
  • This signal has frequencies f 0 , p 1 / q f 0 , p 2 / q f 0 ,. .
  • the initial phase at the frequency (p k / q f 0 ) for each integer k is 2 ⁇ T 0 ⁇ p k / q f 0 , and the frequency and the initial phase have a one-to-one correspondence.
  • a signal whose frequency is continuously distributed within a certain bandwidth can be used as the transmission signal. This corresponds to reducing the frequency increase rate p 1 / q until the peak of each frequency cannot be distinguished on the frequency amplitude characteristic in the signal u (t, T 0 ).
  • the signal w (t) shown in FIG. 3 can also be used as a transmission signal.
  • the transmission signal generation unit 112 uses the signal waveform read from the memory 121 as the transmission signal. However, in step ST12, the transmission signal generation unit 112 may generate a signal waveform and use it as a transmission signal.
  • the object detection apparatus 10 stores a signal waveform such as white noise or pink noise in the memory 121 as a reference waveform as shown in FIG. deep. Then, in step ST12, the transmission signal generation unit 112 reads the reference waveform from the memory 121, and passes the read reference waveform through a bandpass filter having a reference bandwidth as a pass band, thereby generating a signal waveform that becomes a transmission signal. Generate.
  • the passband f is, for example, f 0 ⁇ f ⁇ f q ⁇ 1 .
  • the transmission signal generation unit 112 may perform various other signal processing such as changing the frequency phase characteristics through the all-pass filter on the signal waveform after passing as necessary.
  • the object detection apparatus 10 stores information such as a random number seed necessary for generating the reference waveform in the memory 121 instead of the reference waveform, and the transmission signal generation unit 112 is stored in the memory 121 in step ST12.
  • a reference waveform may be generated from the obtained information.
  • step ST2 ** Detailed operation of step ST2 ** With reference to FIG. 7, the operation of step ST2 according to the first embodiment will be described in detail.
  • the reception unit 132 stores the reception signals for the latest T seconds among the reception signals constantly collected by the acoustic signal input device 22 based on the synchronization signal transmitted by the time synchronization unit 111.
  • the reception unit 132 writes the reception signal collected by the acoustic signal input device 22 to the memory 121 and erases the reception signal that has passed T seconds from the collection from the memory 121.
  • the reception signal generation unit 113 measures the elapsed time from the transmission time at which the previous reception signal was transmitted based on the synchronization signal transmitted by the time synchronization unit 111.
  • the reception signal generation unit 113 advances the process to step ST23 when T1 seconds have elapsed from the transmission time, and returns the process to step ST21 when T1 seconds have not elapsed since the transmission time.
  • the reception signal generation unit 113 reads the reception signal for the latest T seconds stored in the memory 121 and transmits the read reception signal to the detection unit 116.
  • the vehicle signal generation unit 114 acquires the speed of the moving body 100 via the vehicle information acquisition unit 142 and transmits it to the detection unit 116.
  • the environment signal generation unit 115 acquires external environment information via the environment information acquisition unit 143 and transmits the external environment information to the detection unit 116.
  • step ST3 the detection unit 116 calculates cross-correlation functions for the reception signal transmitted by the reception signal generation unit 113 in step ST2 and each of at least two types of reference signals.
  • the detection unit 116 reads the two types of reference signals 1 and 2 from the memory 121 and calculates a cross-correlation function for each of the received signal and the reference signals 1 and 2.
  • the detection unit 116 writes the calculated cross-correlation functions in the memory 121.
  • the reference signal may be a signal that has a peak in the cross-correlation function with the received signal.
  • a transmission signal can be used as a reference signal.
  • an ideal reception signal when the Doppler shift does not occur has a signal waveform similar to a signal obtained by delaying the transmission signal by a time due to the relative distance.
  • the cross-correlation function between the reference signal and the received signal is a peak of the auto-correlation function of the transmission signal shifted by the delay time.
  • the peak position is further shifted accordingly.
  • the reference signal is not limited to the transmission signal, and a signal having a frequency characteristic equivalent to that of the transmission signal can be used.
  • the transmission signal is the signal w (t) shown in Equation 3
  • the signal u (t, T 0 ) and the signal U ( t) can be used as a reference signal.
  • the detection unit 116 determines whether or not there is a peak in each cross-correlation function calculated in step ST31. Specifically, the detection unit 116 reads each cross-correlation function calculated in step ST31 from the memory 121. Then, the detection unit 116 specifies, as a peak, the time at which the value of each cross-correlation function is higher than the surrounding value by a reference value or more. The detection unit 116 determines that there is a peak when there is a time specified as a peak, and determines that there is no peak when there is no time specified as a peak. If there is a peak, the detection unit 116 proceeds to step ST34, and if there is no peak, the process proceeds to step ST35.
  • the detection unit 116 calculates a cross-correlation function in step ST31, determines the presence of a peak, writes the determination result to the memory 121, and reads the determination result from the memory in step ST32 to determine whether a correlation peak exists. It may be determined.
  • the determination result is a peak position when a peak is present, and a flag indicating that no peak is present when no peak is present, that is, no object is detected. In this way, the usage amount of the memory 121 can be reduced.
  • T p is the Celsius temperature. Therefore, the detection unit 116 calculates the sound speed by substituting the air temperature indicated by the external environment information into the approximate expression. When the wind is blowing, the wind speed is added to or subtracted from the sound speed. Therefore, the detection unit 116 calculates the sound speed using the wind speed indicated by the external environment information.
  • the detection part 116 is good also considering a sound speed as a constant like 340 m / s.
  • the detecting unit 116 may measure the speed of sound V s by such sensor.
  • the detection unit 116 determines that the object 200 is detected around the moving body 100 because the peak exists in step ST32, and the relative distance d between the moving body 100 and the detected object 200 is detected. Is estimated. In addition, the detection unit 116 estimates the Doppler shift rate ⁇ . The detection unit 116 estimates the relative distance d and the Doppler shift rate ⁇ by determining how much the maximum peak position of the cross-correlation function between the received signal and the reference signal is shifted from the standard peak position. The detection unit 116 writes the estimated values of the relative distance d and the Doppler shift rate ⁇ in the memory 121.
  • a method for estimating the relative distance d will be described.
  • the signal w (t) shown in Equation 3 is used as a transmission signal and the signal U (t) shown in Equation 4 is used as a reference signal.
  • the transmission path until the transmission signal is received is as follows: acoustic signal output device 21 ⁇ object 200 (source of reflected wave) ⁇ acoustic signal input device 22. Therefore, the path length is d + d.
  • the signal expands and contracts when a Doppler shift occurs.
  • FIG. 9 shows a case where ⁇ > 1. Therefore, as shown in FIG. 10, the maximum peak position ty, U of the cross-correlation function between the received signal y (t) and the reference signal U (t) is the transmission signal w (t) and the reference signal U (t). as the maximum peak position t w, relative to the U of the cross-correlation function between, shifted by the sum of the minute amount and the Doppler shift of the time delay corresponding to the relative distance. Therefore, the shift amount ⁇ t U is expressed by Equation 5.
  • the maximum peak position ty, V of the cross-correlation function between the reception signal y (t) and the reference signal V (t) is the transmission signal w. Shift is performed in the same manner as the maximum peak position ty, U with reference to the maximum peak position tw, V of the cross-correlation function between (t) and the reference signal V (t).
  • the shift amount ⁇ t V is expressed by Equation 6.
  • the detection unit 116 estimates the relative distance d using Equation 8.
  • Equation 9 A method for estimating the Doppler shift rate will be described.
  • the signal w (t) shown in Equation 3 is used as a transmission signal and the signal U (t) and signal V (t) shown in Equation 4 are used as reference signals.
  • the peak shift caused by the Doppler shift has the same distance and the opposite direction, and the peak shift caused by the relative distance has the same distance and the same direction regardless of the reference signal.
  • the peak shift caused by factors other than the Doppler shift can be canceled by taking the difference between the respective peak shift amounts. Therefore, the distance between the maximum peak position ty, U and the maximum peak position ty, V is expressed by Equation 9.
  • Equation 9 the distance between the maximum peak position ty, U and the maximum peak position ty, V is expressed by Equation 9.
  • the detection unit 116 estimates the Doppler shift rate ⁇ using Equation 10.
  • the transmission signal may be a signal including the first signal and the second signal obtained by inverting the first signal.
  • the reference signal may be a signal including the first signal component and a signal including the second signal.
  • the Doppler shift or the peak shift caused by the time delay corresponding to the relative distance d can be canceled.
  • components other than the component included in the reference signal in the transmission signal are signals that do not hinder the cross-correlation peak detection.
  • the signal that does not interfere with the cross-correlation peak detection is, for example, a signal that is uncorrelated with each reference signal.
  • a signal obtained by separating two types of reference signals, the signal U (t) and the signal V (t) by a known different time around the origin of the time axis can be used as a transmission signal.
  • a signal including a signal other than the signal w (t) can also be used as a transmission signal.
  • step ST35 it is assumed that the detection unit 116 does not detect the object 200 around the moving body 100 because no peak exists in step ST32.
  • the detection unit 116 writes a flag indicating that the object 200 is not detected in the memory 121, or stores a special value when the object 200 is not detected as an estimated value of the relative distance d and the relative speed ⁇ v. 121 is written.
  • the detection unit 116 estimates the relative speed ⁇ v between the moving body 100 and the object 200 from the estimated value of the Doppler shift rate ⁇ estimated in step ST34.
  • the detection unit 116 writes the estimated value of the relative speed ⁇ v in the memory 121.
  • the detection unit 116 calculates the relative speed ⁇ v by using the speed v s transmitted by the vehicle signal generation unit 114 in step ST2 and the sound speed V s calculated in step ST33.
  • the relative velocity ⁇ v can be approximated as in Expression 13.
  • the velocity v s transmitted by the vehicle signal generation unit 114 at step ST2 the it is possible to estimate the relative velocity ⁇ v more accurately.
  • step ST38 when the object 200 is detected, the detection unit 116 uses the estimated value of the relative distance d estimated in step ST34 and the estimated value of the relative speed ⁇ v estimated in step ST36. Read from the memory 121. Then, the detection unit 116 outputs the estimated values of the read relative distance d and relative speed ⁇ v. On the other hand, when the object 200 is not detected, the detection unit 116 reads the flag written in the memory 121 in step ST35 or the estimated values of the relative distance d and the relative speed ⁇ v. Then, the detection unit 116 outputs the read flag or estimated values of the relative distance d and the relative speed ⁇ v.
  • the object detection apparatus 10 uses a signal configured by superimposing a plurality of waves having different frequencies as a transmission signal.
  • S / N ratio signal to noise ratio
  • the object 200 at a long distance can be detected.
  • the relative distance d and the relative speed ⁇ v between the moving body 100 and the object 200 can be estimated.
  • an ultrasonic sensor As an apparatus for detecting the object 200 using sound waves, an ultrasonic sensor is known and may be mounted on a moving object for the purpose of detecting an obstacle at a short distance.
  • the ultrasonic sensor transmits and receives a signal having a single frequency component such as 40 kHz. More precisely, the ultrasonic sensor transmits and receives a signal including a frequency component of several percent before and after the center frequency with a single frequency as the center frequency.
  • a signal that can be used as a transmission signal is a pulse signal with a single frequency or a signal (amplitude modulation signal, phase modulation signal, frequency modulation signal) whose amplitude, phase, frequency, etc. are modulated by a specific code.
  • a pulse signal for example, a method is used in which the time when the amplitude of the reception signal exceeds a certain threshold is regarded as the reception time, and the relative distance from the time and speed of sound required for transmission / reception to the obstacle is used. It is done. While this method does not require complicated signal processing, it has a drawback of being vulnerable to noise.
  • a signal having a different frequency, amplitude, phase, or the like assigned to a code pattern such as a modulated signal (M-sequence (maximum length sequence)) is used as a transmission signal.
  • M-sequence maximum length sequence
  • FIG. 11 shows a case where a frequency modulation signal is used as a transmission signal. While this method can improve the S / N ratio by correlation processing, the S / N ratio is improved according to the code length, so that the signal length becomes long to measure a long distance. There is. Furthermore, when at least one of the moving body 100 and the object 200 is moving, a frequency shift due to the Doppler effect (hereinafter referred to as Doppler shift) occurs, so that the frequency modulation signal is not suitable for correlation processing.
  • Doppler shift a frequency shift due to the Doppler effect
  • the S / N ratio can be improved as compared with the case of using a single frequency signal even if the signal length is the same. That is, the object 200 at a long distance can be detected while suppressing an increase in signal length. Further, the reception time can be obtained from the maximum peak position of the cross-correlation function, the relative distance d can be estimated, and the Doppler shift amount can also be estimated from the peak position deviation amount.
  • the object detection apparatus 10 uses a signal obtained by superimposing a plurality of waves whose frequencies increase according to a geometric sequence as a transmission signal. Thereby, the object 200 at a long distance can be detected with higher accuracy. In addition, the relative distance d and the relative speed ⁇ v between the moving body 100 and the object 200 can be estimated with higher accuracy.
  • the Doppler shift works in a multiplicative way. That is, all frequency components are increased or decreased at the same magnification. Therefore, an ideal received signal is obtained by using an attenuation rate ⁇ ( ⁇ 1) due to air, a Doppler shift rate ⁇ , a relative distance d between the moving body 100 and the object 200, and a sound velocity V s. ⁇ (t ⁇ 2d) / V s ).
  • the object 200 can be detected with high accuracy, and the relative distance d and the relative speed ⁇ v between the moving body 100 and the object 200 can be estimated with high accuracy.
  • the object detection apparatus 10 uses a signal obtained by superimposing a plurality of waves having different initial phases for each frequency as a transmission signal. Thereby, the object 200 at a long distance can be detected with higher accuracy. In addition, the relative distance d and the relative speed ⁇ v between the moving body 100 and the object 200 can be estimated with higher accuracy.
  • the object detection apparatus 10 uses a signal obtained by superimposing a plurality of waves having a frequency within either frequency band of a sound wave and a low-frequency ultrasonic wave as a transmission signal. Thereby, the object 200 at a long distance can be detected with higher accuracy. In addition, the relative distance d and the relative speed ⁇ v between the moving body 100 and the object 200 can be estimated with higher accuracy.
  • the object detection apparatus 10 can detect an object 200 at a long distance by suppressing attenuation of energy by using a sound wave in a frequency band lower than this as a transmission signal.
  • signals in the frequency band below 16 kHz are generally within the human audible range. Therefore, it is desirable not to use a frequency band of less than 16 kHz from the viewpoint of health and noise problems.
  • the object 200 can be detected not only within the range of 16 kHz to 40 kHz but also using a signal in a higher frequency band. Therefore, the object detection apparatus 10 uses sound waves or low frequency ultrasonic waves in the range of 16 kHz to 100 kHz.
  • the object detection apparatus 10 calculates the sound speed V s based on the external environment information acquired via the environment information acquisition unit 143. Thereby, the relative speed ⁇ v between the moving body 100 and the object 200 can be calculated with high accuracy.
  • the object detection apparatus 10 has many functions in order to increase the detection accuracy of the object 200 and to increase the estimation accuracy of the relative distance d and the relative speed ⁇ v between the moving body 100 and the object 200.
  • the functional components may be simplified although there is a possibility that the accuracy may be slightly reduced as compared with the first embodiment.
  • the first modification will be described with respect to differences from the first embodiment.
  • the object detection device 10 includes hardware including a processor 11, a storage device 12, and an audio interface 13.
  • the object detection apparatus 10 includes a time synchronization unit 111, a detection unit 116, and a reception unit 132 as functional components.
  • the reception unit 132 receives a reception signal including a reflected wave reflected by an object from the acoustic signal output device 21 mounted on the moving body 100 via the acoustic signal input device 22 mounted on the moving body 100. And accept.
  • the time synchronization unit 111 synchronizes the operations of the acoustic signal output device 21 and the acoustic signal input device 22, and enables time measurement until the sound wave emitted from the acoustic signal output device 21 is received by the acoustic signal input device 22. To do.
  • the detection unit 116 detects the object 200 based on the reception signal received by the reception unit 132 and estimates the relative distance d and the relative speed ⁇ v between the moving body 100 and the object 200.
  • object detection apparatus 10 may have some hardware and functions shown in FIG. 1 added to the configuration shown in FIG. 1 added to the configuration shown in FIG. 1
  • the functions of the time synchronization unit 111, the transmission signal generation unit 112, the reception signal generation unit 113, the vehicle signal generation unit 114, the environment signal generation unit 115, and the detection unit 116 are software.
  • the functions of these units may be realized by hardware. The second modification will be described with respect to differences from the first embodiment.
  • the object detection device 10 includes a processing circuit 15 instead of the processor 11 and the storage device 12.
  • the processing circuit 15 is a dedicated electronic circuit that realizes the functions of each unit of the object detection device 10 and the function of the storage device 12.
  • the processing circuit 15 is assumed to be a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, a logic IC, a GA (Gate Array), an ASIC (Application Specific Integrated Circuit), or an FPGA (Field-Programmable Gate Array). Is done.
  • the function of each part may be realized by one processing circuit 15, or the function of each part may be realized by being distributed to a plurality of processing circuits 15.
  • ⁇ Modification 3> As a third modification, some functions of the time synchronization unit 111, the transmission signal generation unit 112, the reception signal generation unit 113, the vehicle signal generation unit 114, the environment signal generation unit 115, and the detection unit 116 are hard. It may be realized by hardware, and other functions may be realized by software. That is, some of the functions of the object detection device 10 may be realized by hardware, and other functions may be realized by software.
  • the processor 11, the storage device 12, the audio interface 13, the in-vehicle interface 14, and the processing circuit 15 are collectively referred to as “processing circuitries”. That is, the function of each part is realized by a processing circuit.
  • the acoustic signal output device 21 and the acoustic signal input device 22 are arranged at positions close to each other on the front side of the moving body 100 and are objects that are vehicles traveling in front of the moving body 100.
  • An example of detecting 200 has been described.
  • the present invention is not limited to this, and the acoustic signal output device 21 and the acoustic signal input device 22 are arranged at close positions on the rear side of the moving body 100 to detect the object 200 that is a vehicle traveling behind the moving body 100.
  • the acoustic signal output device 21 and the acoustic signal input device 22 may be arranged on both the front side and the rear side of the moving body 100 to detect the object 200 that is a vehicle traveling forward and backward.
  • the object 200 is not limited to a vehicle, and may be other types such as a pedestrian and a building-like structure whose moving speed is equal to or lower than the sound speed.
  • the acoustic signal input device 22 Even if the acoustic signal output device 21 and the acoustic signal input device 22 are not close to each other, the acoustic signal input device 22 generates a reflected wave generated by reflecting the output signal radiated from the acoustic signal output device 21 to the object 200. It only needs to be arranged at a position where it can be collected. In the situation shown in FIG. 2, one acoustic signal input device 22 is disposed on the front side of the moving body 100. However, the number of acoustic signal input devices 22 is not limited to one and may be two or more.
  • the detection unit 116 synthesizes estimation results for reception signals collected by the acoustic signal input devices 22.
  • the estimation results is to take the average of the respective estimated values as a specific example. Thereby, estimation accuracy can be improved.
  • Embodiment 2 When the object 200 is positioned on the oblique side of the moving body 100, the relative velocity ⁇ v estimated from the received signal from one acoustic signal input device 22 becomes an oblique component of the relative velocity ⁇ v of the object 200.
  • the second embodiment is different from the first embodiment in that the object 200 is detected using at least two acoustic signal input devices 22. Thus, in the second embodiment, it is possible to estimate the relative speed ⁇ v even when the object 200 is located obliquely to the moving body 100. In the second embodiment, this different point will be described.
  • the object detection device 10 includes at least two acoustic signal input devices 22.
  • the object detection device 10 includes an acoustic signal input device 22A and an acoustic signal input device 22B.
  • the object detection device 10 includes a reception unit 132 corresponding to each acoustic signal input device 22.
  • the object detection device 10 includes a reception unit 132A corresponding to the acoustic signal input device 22A and a reception unit 132B corresponding to the acoustic signal input device 22B.
  • the operation of the object detection apparatus 10 according to the second embodiment will be described with reference to FIGS. 15 to 17.
  • the operation of the object detection apparatus 10 according to the second embodiment corresponds to the object detection method according to the second embodiment.
  • the operation of the object detection apparatus 10 according to the second embodiment corresponds to the processing of the object detection program according to the second embodiment.
  • the object 200 is a vehicle that runs on the left side of the moving body 100.
  • FIG. 15 shows a moving body 100 in which an acoustic signal output device 21 and two acoustic signal input devices 22 are installed on the left side, and an object 200.
  • the acoustic signal input device 22 ⁇ / b> A is disposed at a position close to the acoustic signal output device 21, and the acoustic signal input device 22 ⁇ / b> B is disposed at a position away from the acoustic signal output device 21.
  • an acoustic signal output device 21 and an audio signal input device 22A, between the acoustic signal input device 22B is the distance d 12.
  • the shortest path length and the shortest path length from the acoustic signal output device 21 to the object 200, the source of the reflected wave to the acoustic signal input device 22A are both becomes substantially equal distance d 1.
  • the generation source of the reflected wave is a position where the transmission signal output from the acoustic signal output device 21 reaches the object 200 in the shortest time.
  • the shortest path length to the audio signal input device 22B from the source of the reflected wave is a distance d 2.
  • the angles formed by the acoustic signal output device 21 and the acoustic signal input device 22A and the reflected wave generation source are almost equal to ⁇ 1 .
  • step ST1 Since the overall operation and the detailed operation in step ST1 are the same as those in the first embodiment, description thereof is omitted.
  • step ST2 ** Detailed operation of step ST2 ** With reference to FIG. 16, the operation in step ST2 according to the second embodiment will be described in detail.
  • the process of step ST22 is the same as the process of step ST22 of FIG.
  • the reception unit 132A stores the reception signal 1 for the latest T seconds in the memory 121 among the reception signals 1 that are always collected by the acoustic signal input device 22A.
  • the reception unit 132B stores the reception signal 2 for the latest T seconds in the memory 121 among the reception signals 2 that are always collected by the acoustic signal input device 22B.
  • the reception signal generation unit 113 reads the reception signals 1 and 2 for the latest T seconds stored in the memory 121, and transmits the read reception signals 1 and 2 to the detection unit 116.
  • the vehicle signal generation unit 114 acquires the speed of the moving body 100 via the vehicle information acquisition unit 142 and transmits it to the detection unit 116.
  • the environment signal generation unit 115 acquires external environment information via the environment information acquisition unit 143 and transmits the external environment information to the detection unit 116.
  • step ST3 ** Detailed operation of step ST3 ** With reference to FIG. 17, the operation in step ST3 according to the second embodiment will be described in detail.
  • the processing from step ST32 to step ST33 is the same as the processing from step ST32 to step ST33 in FIG.
  • the process of step ST35 is the same as the process of step ST35 of FIG.
  • the detection unit 116 calculates a cross-correlation function for each of the reception signals 1 and 2 transmitted by the reception signal generation unit 113 in step ST2 and each of at least two types of reference signals 1 and 2. To do.
  • the detection unit 116 reads the two types of reference signals 1 and 2 from the memory 121 and calculates a cross-correlation function for each of the received signals 1 and 2 and each of the reference signals 1 and 2. The detection unit 116 writes the calculated cross-correlation functions in the memory 121.
  • the detection unit 116 estimates the relative distance d between the moving body 100 and the detected object 200 and the Doppler shift rate ⁇ .
  • the detection unit 116 writes the estimated values of the relative distance d and the Doppler shift rate ⁇ in the memory 121.
  • the detection unit 116 calculates the average peak shift amount according to Equation 7 for each of the received signals 1 and 2 by the same process as the process of step ST34 in FIG. Using the average peak shift amount ⁇ t 1 ⁇ calculated for the received signal 1 and the average peak shift amount ⁇ t 2 ⁇ calculated for the received signal 2, the detection unit 116 calculates the relative distance d 1 , to estimate the d 2.
  • the relative distance d 1 the transmission path to the transmission signal is received, the audio signal output device 21 ⁇ the object 200 (the source of the reflected wave) ⁇ acoustic signal input device 22A. Therefore, the path length is d 1 + d 1 .
  • the estimated value of the relative distance d 1 is calculated by 1/2 a value obtained by converting the time required for transmission and reception distance.
  • the path length is d. a 1 + d 2. Therefore, estimates of the relative distance d 2 is calculated by subtracting the relative distance d 1 from the value obtained by converting the time required for transmission and reception distance.
  • the detection unit 116 estimates the Doppler shift rate ⁇ according to Equation 10 for each of the received signals 1 and 2 by the same process as the process of step ST34 of FIG. In the situation shown in FIG. 15, an estimate of the Doppler shift rate [rho calculated from the received signals collected by the audio signal input unit 22A and [rho 1, were calculated from the received signals collected by the audio signal input device 22B Doppler the estimated value of the shift rate ⁇ and ⁇ 2.
  • detector 116 In the second calculation process in step ST36B, detector 116, along with the estimates from the estimated value [rho 1 of the Doppler shift rate estimated [rho relative speed Delta] v 1 in step ST34B, estimating the relative velocity Delta] v 2 from the estimated value [rho 2 To do.
  • the estimated values ⁇ 1 and ⁇ 2 are each expressed by Expression 16.
  • the values of cos ⁇ 1 and cos ⁇ 2 can be calculated based on the principle of triangulation from the triangles of three sides d 12 , d 1 , and d 2 in FIG.
  • the distance d 12 because of the distance between the acoustic signal input unit 22A and the acoustic signal input unit 22B, a known value.
  • the relative distance d 1 and the relative distance d 2 can be used an estimate of the calculated relative distance in step ST34B.
  • the detection unit 116 calculates cos ⁇ 1 and cos ⁇ 2 by Expression 17 from the values of the distance d 12 , the relative distance d 1, and the relative distance d 2 .
  • the detection unit 116 substitutes the velocity v s of the moving body 100, the sound velocity V s, and the calculated values of cos ⁇ 1 and cos ⁇ 2 in the respective equations of the estimated values ⁇ 1 and ⁇ 2 of Equation 16, and the velocity Solve for vo .
  • the detection unit 116 estimates the relative speed ⁇ v by integrating the estimated values ⁇ v 1 and ⁇ v 2 corresponding to the acoustic signal input devices 22A and 22B estimated in step ST36B. Specifically, in Embodiment 2, the detection unit 116 estimates the relative speed ⁇ v by calculating the average of the estimated values ⁇ v 1 and ⁇ v 2 . The detection unit 116 writes the estimated relative speed ⁇ v in the memory 121. Note that the detection unit 116 performs a method of setting the mode of the distribution of the estimated values ⁇ v 1 and ⁇ v 2 as a relative velocity ⁇ v, or performs an outlier determination process, and calculates the relative velocity ⁇ v using only an estimation result that is not an outlier. The relative speed ⁇ v may be calculated by another method such as.
  • step ST38B when the object 200 is detected, the detection unit 116 calculates the estimated values of the relative distances d 1 and d 2 estimated in step ST34B and the relative velocity ⁇ v estimated in step ST37B. The estimated value is read from the memory 121. Then, the detection unit 116 outputs the estimated values of the read relative distances d 1 and d 2 and the relative speed ⁇ v. On the other hand, when the object 200 is not detected, the detection unit 116 reads the flag written in the memory 121 in step ST35 or the estimated values of the relative distances d 1 and d 2 and the relative speed ⁇ v. Then, the detecting unit 116 outputs the read flag or the estimated values of the relative distances d 1 and d 2 and the relative speed ⁇ v.
  • the detection unit 116 may calculate the relative position coordinates of the object 200 from the estimated relative distance values d 1 and d 2 and the known distance d 12 according to the principle of triangulation and output the calculated coordinates. .
  • the object detection apparatus 10 applies the principle of triangulation to estimation results obtained from a plurality of received signals. Thereby, even when the object 200 exists on the side of the moving body 100 and the transmission path of the transmission signal has an angle, the relative distance d and the relative speed ⁇ v can be estimated.
  • the relative distance d and the relative speed can be obtained by arranging one acoustic signal input device 22 on the side of the moving body 100 as in the first embodiment. ⁇ v can be estimated.
  • two acoustic signal input devices 22 ⁇ / b> A and 22 ⁇ / b> B are arranged on the left side of the moving body 100. Thereby, the object 200 existing on the left side of the moving body 100 is detected.
  • two acoustic signal input devices 22 may be arranged on the right side of the moving body 100 to detect the object 200 present on the right side of the moving body 100.
  • two acoustic signal input devices 22 may be disposed on both the left and right sides of the moving body 100 to detect the object 200 present on both the left and right sides of the moving body 100.
  • ⁇ Modification 6> In the second embodiment, two acoustic signal input devices 22 are arranged. However, as a sixth modification, three or more acoustic signal input devices 22 may be arranged. When three or more acoustic signal input devices 22 are arranged, the detection unit 116 estimates the relative distance d and the Doppler shift rate ⁇ for each acoustic signal input device 22 in step ST34B. Further, in step ST36B to step ST37B, the detection unit 116 calculates the relative speed ⁇ v corresponding to each acoustic signal input device 22, and integrates the calculated relative speed ⁇ v. By using three or more acoustic signal input devices 22, triangulation is performed a plurality of times, and the estimation accuracy between the relative velocity ⁇ v and the relative position coordinates of the object 200 can be increased.
  • Embodiment 3 At a distance where the reflected wave reflected by the object 200 and the direct sound transmitted from the acoustic signal output device 21 and not reflected by the object 200 overlap, the cross-correlation function does not peak and the object 200 may not be detected.
  • the third embodiment is different from the second embodiment in that the object 200 is detected using at least two acoustic signal output devices 21.
  • the cross-correlation function has a peak even at a distance where the reflected wave and the direct sound overlap, and the object 200 can be detected with high accuracy. In the third embodiment, this different point will be described.
  • the object detection device 10 includes at least two acoustic signal output devices 21.
  • the object detection device 10 includes an acoustic signal output device 21A and an acoustic signal output device 21B.
  • the object detection device 10 includes a radiation unit 131 corresponding to each acoustic signal output device 21.
  • the object detection device 10 includes a radiation unit 131A corresponding to the acoustic signal output device 21A and a radiation unit 131B corresponding to the acoustic signal output device 21B.
  • the operation of the object detection apparatus 10 according to the third embodiment will be described with reference to FIGS.
  • the operation of the object detection apparatus 10 according to the third embodiment corresponds to the object detection method according to the third embodiment.
  • the operation of the object detection apparatus 10 according to the third embodiment corresponds to the processing of the object detection program according to the third embodiment.
  • FIG. 19 shows a moving body 100 in which two acoustic signal output devices 21 and two acoustic signal input devices 22 are installed on the left side, and an object 200.
  • the acoustic signal input device 22A is disposed at a position close to the acoustic signal output device 21A
  • the acoustic signal input device 22B is disposed at a position close to the acoustic signal output device 21B.
  • the audio signal output device 21B and the audio signal input unit 22B is the distance d 12. Further, the shortest path length from the acoustic signal output device 21A to the object 200 and the shortest path length from the reflected wave generation source of the transmission signal output from the acoustic signal output device 21A to the acoustic signal input device 22A are almost all.
  • the distance d A1 is equal.
  • the shortest path length from the acoustic signal output device 21B to the object 200 and the shortest path length from the reflected wave generation source of the transmission signal output from the acoustic signal output device 21B to the acoustic signal input device 22B are almost all.
  • the distance is equal to d B1 .
  • the shortest path length from the reflected wave generation source to the acoustic signal input device 22A is the distance dB2 .
  • the angles formed by the acoustic signal output device 21A and the acoustic signal input device 22A and the generation source of the reflected wave of the transmission signal output from the acoustic signal output device 21A are substantially equal to ⁇ A1 .
  • the angle formed between the acoustic signal input device 22B and the generation source of the reflected wave is ⁇ A2 .
  • the angles formed by the acoustic signal output device 21B and the acoustic signal input device 22B and the generation source of the reflected wave of the transmission signal output from the acoustic signal output device 21B are substantially equal to ⁇ B1 .
  • the angle formed by the acoustic signal input device 22A and the source of the reflected wave is ⁇ B2 .
  • the moving body 100 travels at a speed v s
  • the object 200 travels at a speed v o.
  • step ST2 Since the overall operation and the detailed operation in step ST2 are the same as those in the second embodiment, description thereof is omitted.
  • step ST1 ** Detailed operation of step ST1 ** Referring to FIG. 20, the operation of step ST1 according to Embodiment 3 will be described in detail.
  • the process of step ST11 is the same as the process of step ST11 of FIG.
  • the transmission signal generation unit 112 reads a signal waveform stored in advance in the memory 121, and transmits the read signal waveform to the radiation units 131A and 131B as a transmission signal.
  • the radiating units 131 ⁇ / b> A and 131 ⁇ / b> B radiate the transmission signal as an acoustic signal via the acoustic signal output device 21.
  • the transmission signal radiated from the radiating unit 131A is referred to as a transmission signal A
  • the transmission signal radiated from the radiating unit 131B is referred to as a transmission signal B.
  • the transmission signals A and B transmitted from the acoustic signal output devices 21A and 21B are different signals. Specifically, the transmission signals A and B are uncorrelated with each other. That is, no peak appears in the cross-correlation function between the transmission signals A and B.
  • step ST3 ** Detailed operation of step ST3 ** With reference to FIG. 21, the operation of step ST3 according to Embodiment 3 will be described in detail.
  • the processing from step ST32 to step ST33 is the same as the processing from step ST32 to step ST33 in FIG.
  • the process of step ST35 is the same as the process of step ST35 of FIG.
  • the detection unit 116 performs the reception signals 1 and 2 transmitted by the reception signal generation unit 113 in step ST2 and at least four types of reference signals A1, A2, B1, and B2, respectively. Calculate the cross-correlation function.
  • the reference signals A1 and A2 are two types of reference signals corresponding to the transmission signal A.
  • the reference signals B1 and B2 are two types of reference signals corresponding to the transmission signal B.
  • the detection unit 116 reads four types of reference signals A1, A2, B1, and B2 from the memory 121, and calculates cross-correlation functions for the received signals 1 and 2 and the reference signals A1, A2, B1, and B2, respectively. calculate.
  • both the received signal 1 and the received signal 2 are a mixture of a reflected wave corresponding to the transmission signal A and a reflected wave corresponding to the transmission signal B.
  • calculating the cross-correlation function with the reference signals A1 and A2 for the reception signals 1 and 2 respectively corresponds to the reflected wave of the transmission signal A. Only the correlation peak stands.
  • the cross-correlation function between the received signals 1 and 2 and the reference signals B1 and B2 is calculated, only a correlation peak corresponding to the reflected wave of the transmission signal B is generated.
  • the detection unit 116 estimates the relative distance d and the Doppler shift rate ⁇ for each of the transmission signals A and B by the same process as in step ST34B in FIG.
  • the detection unit 116 writes the estimated values of the relative distance d and the Doppler shift rate ⁇ in the memory 121.
  • the estimated values of the relative distance d from each acoustic signal input device 22 to the object 200 corresponding to the transmission signal A are respectively estimated values d A1 and d A2
  • the estimated values of the Doppler shift rate ⁇ are respectively estimated values ⁇ . A1, and ⁇ A2.
  • the estimated values of the relative distance d from each acoustic signal input device 22 to the object 200 corresponding to the transmission signal B are respectively estimated values d B1 and d B2, and the estimated values of the Doppler shift rate ⁇ are respectively estimated values ⁇ B1. , ⁇ B2 .
  • the detection unit 116 estimates the relative speed ⁇ v A1 from the estimated value ⁇ A1 of the Doppler shift rate ⁇ estimated in step ST34C by the same process as in step ST36B in FIG. estimating the relative velocity Delta] v A2 from the value [rho A2, it estimates the relative velocity Delta] v B1 from the estimated value [rho B1, estimates the relative velocity Delta] v B2 from the estimated value [rho B2.
  • Equation 18 A method for estimating the relative speed ⁇ v will be described.
  • the estimated values ⁇ A1 , ⁇ A2 , ⁇ B1 , and ⁇ B2 are each expressed by Equation 18.
  • Detector 116 similar to the values of cos [theta] 1 and cos [theta] 2 in step ST36B shown in FIG. 17, based on the principle of trilateration to compute the number 19 the value of cos [theta] A1 and cos [theta] A2 and cos [theta] B1 and cos [theta] B2 .
  • the detecting unit 116 calculates the velocity v s of the moving body 100, the sound velocity V s, and the calculated values of cos ⁇ A1 , cos ⁇ A2 , cos ⁇ B1, and cos ⁇ B2 from the estimated values ⁇ A1 , ⁇ A2 , ⁇ of Equation 18.
  • B1, ⁇ B2 is assigned to each of the equation, solving for velocity v o.
  • detector 116, the transmission signal A, B and the acoustic signal input device 22A, the relative speed corresponding to each combination of the 22B ⁇ v v o -v s estimate ⁇ v A1, ⁇ v A2, ⁇ v B1 , ⁇ v Get B2 .
  • the detection unit 116 combines the estimated values d A1 and d B1 estimated in step ST34C to estimate the relative distance d 1 , and the estimated values d A2 and d B2 to estimate the distance d 2.
  • the detection unit 116 estimates the relative speed ⁇ v by combining the estimated values ⁇ v A1 , ⁇ v A2 , ⁇ v B1 , ⁇ v B2 estimated in step ST36C.
  • the detecting unit 116 calculates the average of the estimated values d A1 and d B2 to estimate the relative distance d 1 and calculates the average of the estimated values d A2 and d B2. by estimates a relative distance d 2.
  • the detection unit 116 estimates the relative velocity ⁇ v by calculating the average of the estimated values ⁇ v A1 , ⁇ v A2 , ⁇ v B1 , ⁇ v B2 .
  • the detection unit 116 writes the estimated relative speed ⁇ v in the memory 121.
  • the detection unit 116 performs a method of setting the mode of the distribution of the estimated values ⁇ v A1 , ⁇ v A2 , ⁇ v B1 , ⁇ v B2 as a relative velocity ⁇ v, or performs an outlier determination process, and uses only an estimation result that is not an outlier.
  • the relative speed ⁇ v may be calculated by another method such as calculating the relative speed ⁇ v.
  • step ST38C when the object 200 is detected, the detection unit 116 reads the estimated values of the relative distances d 1 and d 2 and the estimated value of the relative velocity ⁇ v estimated in step ST37C from the memory 121. . Then, the detection unit 116 outputs the estimated values of the read relative distances d 1 and d 2 and the relative speed ⁇ v. On the other hand, when the object 200 is not detected, the detection unit 116 reads the flag written in the memory 121 in step ST35 or the estimated values of the relative distances d 1 and d 2 and the relative speed ⁇ v. Then, the detecting unit 116 outputs the read flag or the estimated values of the relative distances d 1 and d 2 and the relative speed ⁇ v.
  • the detection unit 116 may calculate and output the relative position coordinates of the object 200 from the estimated relative distance values d 1 and d 2 and the known distance d 12 according to the principle of triangulation. .
  • the object detection apparatus 10 detects the object 200 using a plurality of transmission signals. Thereby, even in the distance where the reflected wave and the direct sound overlap, the cross-correlation function has a peak, and the object 200 can be detected with high accuracy.
  • two acoustic signal output devices 21 ⁇ / b> A and 21 ⁇ / b> B and two acoustic signal input devices 22 ⁇ / b> A and 22 ⁇ / b> B are arranged on the left side of the moving body 100. Thereby, the object 200 existing on the left side of the moving body 100 is detected.
  • two acoustic signal output devices 21 and two acoustic signal input devices 22 may be arranged on the right side of the moving body 100 to detect the object 200 present on the right side of the moving body 100.
  • two acoustic signal output devices 21 and two acoustic signal input devices 22 are arranged on the left and right sides of the moving body 100 to detect the object 200 existing on both the left and right sides of the moving body 100. Good.
  • ⁇ Modification 8> In the third embodiment, two acoustic signal output devices 21 are arranged. However, as a modified example 8, three or more acoustic signal output devices 21 may be arranged.
  • the detection unit 116 estimates the relative distance d and the Doppler shift rate ⁇ for each acoustic signal output device 21 in step ST34C.
  • the detection unit 116 calculates the relative speed ⁇ v corresponding to each acoustic signal output device 21.
  • step ST37C the detection unit 116 combines the calculated relative distance d and relative speed ⁇ v.
  • ⁇ Modification 9> In the third embodiment, two acoustic signal output devices 21 that radiate different transmission signals are arranged. However, as a ninth modification, a transmission signal obtained by superimposing uncorrelated signals from one acoustic signal output device 21 may be transmitted. As a result, as in the third embodiment, the cross-correlation function has a peak even at the distance where the reflected wave and the direct sound overlap, and the object 200 can be detected with high accuracy. Note that the degree of decorrelation does not necessarily have to be completely uncorrelated, as long as it satisfies the detection accuracy or measurement performance required for the object detection apparatus 10.
  • Embodiment 4 FIG.
  • the object 200 existing around the moving body 100 is detected.
  • the fourth embodiment is different from the first to third embodiments in that the moving body 100 is controlled based on the detected result. In the fourth embodiment, this different point will be described. In the fourth embodiment, a case where a function is added to the first embodiment will be described. However, it is possible to add functions to the second and third embodiments.
  • the in-vehicle interface 14 is connected to the vehicle control ECU 25.
  • the vehicle control ECU 25 is a device that controls control devices such as a brake, an accelerator, and a steering wheel.
  • the object detection apparatus 10 includes a control unit 117 as a functional component.
  • the function of the control unit 117 is realized by software, similar to the detection unit 116 and the like.
  • the operation of the object detection apparatus 10 according to the fourth embodiment corresponds to the object detection method according to the fourth embodiment.
  • the operation of the object detection apparatus 10 according to the fourth embodiment corresponds to the processing of the object detection program according to the fourth embodiment.
  • the object detection device 10 detects the object 200 existing around the moving body 100 and estimates the relative distance d and the relative speed ⁇ v by the method described in the first embodiment.
  • step ST42 when the object 200 is detected in step ST41, the control unit 117 sends a control signal for controlling the moving body 100 based on the output relative distance d and relative speed ⁇ v to the in-vehicle interface 14. To the vehicle control ECU 25. Thereby, the control unit 117 controls the operation of the moving body 100.
  • the control unit 117 transmits a control signal for controlling the brake to the vehicle control ECU 25.
  • the brake is controlled, the moving body 100 is decelerated, and the moving body 100 is prevented from colliding with the object 200.
  • the object 200 in the lateral direction is detected, and if there is no object 200 at the planned destination location, the steering wheel is controlled so that the lane is changed. Control the handle etc. so that it does not change. This prevents the object 200 from colliding with the lane change.
  • the functions of the respective units of the object detection device 10 are realized by software.
  • the function of each unit of the object detection device 10 may be realized by hardware.
  • the object detection device 10 may have some functions realized by hardware and other functions realized by software.
  • the first embodiment has described that the object 200 existing in the front-rear direction of the moving body 100 is detected.
  • the detection of the object 200 that exists in the left-right direction of the moving body 100 has been described. These may be combined so that the object 200 existing in the front-rear and left-right directions of the moving body 100 can be detected.
  • the acoustic signal output device 21 and the acoustic signal input device 22 may be arranged on the bottom side of the moving body 100 to detect the object 200 present on the road surface on which the moving body 100 travels. Further, the acoustic signal output device 21 and the acoustic signal input device 22 may be arranged on the upper side of the moving body 100 to detect the object 200 existing on the upper side of the moving body 100.

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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 un appareil de détection d'objet (10) qui est monté sur un corps mobile (100). Une unité de rayonnement (131) rayonne un signal acoustique généré par la superposition d'une pluralité d'ondes différentes en fréquence par un appareil de sortie de signal acoustique (21) monté sur le corps mobile (100). Une unité de réception (132) reçoit un signal d'onde de réflexion généré en résultat du fait que le signal acoustique, qui a été rayonné depuis l'unité de rayonnement (131) montée sur le corps mobile (100), est réfléchi sur un objet. Une unité de détection (116) détecte l'objet présent autour du corps mobile (100) en calculant une valeur de corrélation entre un signal de référence et un signal de réception, le signal de réception étant le signal d'onde de réflexion reçu par l'unité de réception (132).
PCT/JP2016/054543 2016-02-17 2016-02-17 Appareil de détection d'objet, procédé de détection d'objet, et programme de détection d'objet WO2017141370A1 (fr)

Priority Applications (2)

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PCT/JP2016/054543 WO2017141370A1 (fr) 2016-02-17 2016-02-17 Appareil de détection d'objet, procédé de détection d'objet, et programme de détection d'objet
JP2016568980A JPWO2017141370A1 (ja) 2016-02-17 2016-02-17 物体検出装置、物体検出方法及び物体検出プログラム

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PCT/JP2016/054543 WO2017141370A1 (fr) 2016-02-17 2016-02-17 Appareil de détection d'objet, procédé de détection d'objet, et programme de détection d'objet

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JP2019113360A (ja) * 2017-12-21 2019-07-11 アイシン精機株式会社 距離計測装置
US20210055397A1 (en) * 2018-05-11 2021-02-25 Denso Corporation Object detection device
WO2021130818A1 (fr) * 2019-12-23 2021-07-01 三菱電機株式会社 Dispositif de détection, procédé de détection et programme de détection
JP2022040288A (ja) * 2017-12-21 2022-03-10 株式会社アイシン 距離計測装置
JPWO2022224355A1 (fr) * 2021-04-20 2022-10-27

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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2019113360A (ja) * 2017-12-21 2019-07-11 アイシン精機株式会社 距離計測装置
JP2022040288A (ja) * 2017-12-21 2022-03-10 株式会社アイシン 距離計測装置
JP7197030B2 (ja) 2017-12-21 2022-12-27 株式会社アイシン 距離計測装置
US20210055397A1 (en) * 2018-05-11 2021-02-25 Denso Corporation Object detection device
WO2021130818A1 (fr) * 2019-12-23 2021-07-01 三菱電機株式会社 Dispositif de détection, procédé de détection et programme de détection
JPWO2021130818A1 (ja) * 2019-12-23 2021-12-23 三菱電機株式会社 検出装置、検出方法、及び、検出プログラム
JPWO2022224355A1 (fr) * 2021-04-20 2022-10-27
WO2022224355A1 (fr) * 2021-04-20 2022-10-27 三菱電機株式会社 Dispositif, procédé et programme de détection d'objet
JP7278519B2 (ja) 2021-04-20 2023-05-19 三菱電機株式会社 物体検出装置、物体検出方法、及び、物体検出プログラム

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