WO2014061192A1 - Distance detection device, distance detection method, and persistent tangible computer-readable medium therefor - Google Patents

Distance detection device, distance detection method, and persistent tangible computer-readable medium therefor Download PDF

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Publication number
WO2014061192A1
WO2014061192A1 PCT/JP2013/005278 JP2013005278W WO2014061192A1 WO 2014061192 A1 WO2014061192 A1 WO 2014061192A1 JP 2013005278 W JP2013005278 W JP 2013005278W WO 2014061192 A1 WO2014061192 A1 WO 2014061192A1
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target
distance
distance detection
sensitivity
sound wave
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PCT/JP2013/005278
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French (fr)
Japanese (ja)
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岳人 原田
大塚　秀樹
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株式会社デンソー
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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
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
    • G01S15/88—Sonar systems specially adapted for specific applications
    • G01S15/93—Sonar systems specially adapted for specific applications for anti-collision purposes
    • G01S15/931—Sonar systems specially adapted for specific applications for anti-collision purposes of land vehicles
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/52—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S15/00
    • G01S7/52004—Means for monitoring or calibrating
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/52—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S15/00
    • G01S7/523—Details of pulse systems
    • G01S7/526—Receivers
    • G01S7/527—Extracting wanted echo signals
    • G01S7/5276—Extracting wanted echo signals using analogue techniques

Definitions

  • the present disclosure relates to a distance detection device that detects a distance to a target by transmitting and receiving sound waves, a distance detection method, and a continuous tangible computer-readable medium for distance detection.
  • a distance detection device As a distance detection device, a device that distinguishes a moving object from a stationary object using the Doppler effect is known (for example, see Patent Document 1).
  • the distance detection device has a problem that it is difficult to distinguish different stationary objects such as small steps and wall surfaces.
  • a distance detection device that detects a distance to a target by transmitting and receiving sound waves is preset with a reception level of a reflected wave obtained by reflecting the transmitted sound waves on the target.
  • a target determination device that determines the presence or absence of a target and a distance to the target by comparing the threshold values with each other, and a plurality of targets having different reflection surface sizes after transmitting the sound wave
  • a sensitivity changing device that sets a higher sensitivity for the target determination device to obtain a reflected wave after a corresponding time corresponding to a reference distance within a possible distance range has elapsed.
  • the sensitivity is increased in a region farther than the reference distance, so that the reflective surface is small (low reflectance) and the reflective surface is large (high reflectance). ) Both can be detected.
  • the sensitivity is lowered, so that a small reflection surface is not detected, and a large reflection surface can be detected. Therefore, a plurality of targets can be identified by detecting a change between a state where the target can be detected and a state where the target cannot be detected in a process in which the distance to the target changes with the reference distance interposed therebetween. This is particularly useful in a system that requires both detection accuracy and response, such as a system that applies a brake according to detection information of a sonar.
  • the persistent tangible computer readable medium for distance detection provided with the computer-implemented instructions includes a computer-implemented method that configures each device of the distance detection apparatus in the first aspect.
  • the above computer-readable medium is useful in a system that requires both detection accuracy and response. Therefore, it is possible to satisfactorily identify a plurality of targets having different sizes of sound wave reflection surfaces, such as whether a target approaching the reference distance or more and less than the reference distance is a small step or a wall surface, for example. it can.
  • a distance detection method for detecting a distance to a target by transmitting and receiving sound waves transmits the sound waves, and receives the reflected waves obtained by reflecting the transmitted sound waves on the targets. Then, by comparing the reception level of the reflected wave with a preset threshold value, the presence / absence of the target and the distance to the target are determined, and the reflected sound is reflected after the corresponding time has elapsed since the sound wave was transmitted. Setting the sensitivity to receive waves higher.
  • the corresponding time corresponds to a reference distance that is within a distance range in which a plurality of targets having different acoustic wave reflection surface sizes can be identified.
  • the distance detection method described above is useful in a system that requires both detection accuracy and response. Therefore, it is possible to satisfactorily identify a plurality of targets having different sizes of sound wave reflection surfaces, such as whether a target approaching the reference distance or more and less than the reference distance is a small step or a wall surface, for example. it can.
  • FIG. 1 is an explanatory diagram showing a schematic configuration of a distance detection system of the present disclosure
  • FIG. 2 is a flowchart showing a detection process executed by the calculation unit 11 of the sound wave sensor 10.
  • 3 (A) to 3 (C) are graphs showing reflected wave intensities corresponding to various threshold values
  • 4 (A) to 4 (C) are graphs showing the reflected wave intensity when the target is a wall surface
  • FIGS. 5A to 5C are graphs showing the reflected wave intensity when the target is a step
  • FIGS. 6A to 6B are graphs showing the reflected wave intensity when the target is a ⁇ 400 pole
  • FIG. 7 is a flowchart showing avoidance processing executed by the CPU of the collision avoidance control unit.
  • the distance detection system 1 to which the present disclosure is applied is mounted on a vehicle such as a passenger car, for example, and detects obstacles such as a wall surface and a step located in front of or behind the vehicle (own vehicle), and the vehicle travel This is a system that performs control such as braking when there is a hindrance (eg wall surface).
  • the distance detection system 1 includes a sound wave sensor 10, a sonar control unit 30, a collision avoidance control unit 40, and a brake actuator 50.
  • the sonic sensor 10 and the sonar control unit 30 are connected via a communication line 4 that performs communication using, for example, the LIN protocol.
  • the sonar control unit 30, the collision avoidance control unit 40, and the brake actuator 50 include, for example, the CAN protocol.
  • the communication line 5 is used for communication.
  • the sound wave sensor 10 has a function as a well-known sound wave sensor that detects a distance to a target that reflects sound waves by transmitting and receiving sound waves such as ultrasonic waves.
  • the sound wave sensor 10 of the present embodiment has a function of changing the sensitivity according to the distance of the target to be detected. A function for changing the sensitivity will be described later.
  • the sonic sensor 10 includes a calculation unit 11, a transmission / reception unit 12, a first amplification unit 13, a variable amplification unit 14, a second amplification unit 15, a comparison unit 16, a threshold voltage generation unit 17, and a communication unit 18. And.
  • the calculation unit 11 is configured as a computer including a CPU 11a, a memory 11b, and the like, and transmits various commands to each unit constituting the acoustic wave sensor 10. In addition, the calculating part 11 implements processes, such as a detection process mentioned later.
  • the memory 11b stores a distance detection program referred to in the present disclosure and is executed by the CPU 11a.
  • the transmission / reception unit 12 transmits a sound wave in response to a command from the calculation unit 11 and receives a reflected wave from the target. And a signal is produced
  • the transmission / reception part 12 is comprised from the piezoelectric element, for example.
  • the first amplifying unit 13 and the second amplifying unit 15 are configured by an amplifier circuit such as an amplifier.
  • the first amplification unit 13 amplifies the signal output from the transmission / reception unit 12 with a predetermined amplification factor.
  • the variable amplifying unit 14 amplifies the signal output from the first amplifying unit 13 at an arbitrary amplification factor set by the arithmetic unit 11 each time.
  • the second amplifying unit 15 amplifies the signal output from the variable amplifying unit 14 with a predetermined amplification factor.
  • the threshold voltage generator 17 generates a threshold voltage for comparison in accordance with a command from the calculator 11.
  • the comparison unit 16 compares the threshold voltage generated by the threshold voltage generation unit 17 with the voltage of the signal output from the second amplification unit 15, and when the signal voltage exceeds the threshold voltage, the calculation unit 11 outputs a signal.
  • the computing unit 11 computes the distance at which the target that reflected the sound wave exists according to the timing at which the signal from the comparing unit 16 is received.
  • the calculation unit 11 transmits the calculation result of the distance to the target to the sonar control unit 30 via the communication unit 18 and the communication line 4.
  • the communication unit 18 (the same applies to communication units 38 and 48 described later) is configured as a known communication module that performs communication via the communication lines 4 and 5.
  • the sonar control unit 30 includes a CPU 31, a memory 32, and a communication unit 38.
  • the CPU 31 performs processing according to the program stored in the memory 32. Specifically, the CPU 31 controls the acoustic sensor 10 such as setting for the acoustic sensor 10, and the collision avoidance of the calculation result of the distance to the target. Processing to be transmitted to the control unit 40 is performed.
  • the collision avoidance control unit 40 has a function of controlling the controlled object such as the brake actuator 50 according to the detection result of the target.
  • the collision avoidance control unit 40 includes a CPU 41, a memory 42, and a communication unit 48.
  • the CPU 41, the memory 42, and the communication unit 48 have the same hardware configuration as the CPU 31, the memory 32, and the communication unit 38 provided in the sonar control unit 30.
  • CPU41 of the collision avoidance control part 40 performs processes, such as an avoidance process mentioned later.
  • the calculation unit 11 (CPU 11a) of the sound wave sensor 10 performs the detection process shown in FIG.
  • the detection process is a process for detecting the distance to the target while changing the sensitivity.
  • the sound wave transmission timing is determined whether or not the sound wave transmission timing has come (S110).
  • the sound wave is set to be transmitted at a preset period (for example, 100 ms).
  • a preset period for example, 100 ms.
  • the specified time represents a time corresponding to a reference distance within a distance range in which a plurality of targets having different sizes of sound wave reflection surfaces can be identified after the sound wave is transmitted.
  • the reference distance When the length is 2 m, it is about 12 ms.
  • the sensitivity of the sound wave sensor 10 is set relatively low (S140). Specifically, by setting the amplification factor by the variable amplification unit 14 to be relatively low and setting the threshold voltage to be generated by the threshold voltage generation unit 17 to be relatively high, a small step or the like on the reflection surface is not detected. In addition, a wall surface having a large reflection surface can be detected. When such a process is completed, the process proceeds to S170 described later.
  • S130 if the specified time has elapsed (S130: YES), it is determined whether or not a preset measurement end time has elapsed since the sound wave was transmitted (S150).
  • a preset measurement end time a time (for example, 30 ms: equivalent to 5 m) from the start of transmission of sound waves to the end of detection of a necessary distance is set.
  • the sensitivity of the sound wave sensor 10 is set relatively high (S160). Specifically, by setting the amplification factor by the variable amplifying unit 14 to be relatively high and setting the threshold voltage to be generated by the threshold voltage generating unit 17 to be relatively low, one having a small reflecting surface and a large reflecting surface. Be able to detect both things.
  • the amplification factor (gain) by the variable amplification unit 14 and the threshold voltage (threshold) to be generated by the threshold voltage generation unit 17 are set. That is, the gain is switched to a higher gain at the reference distance (A), and the threshold voltage is switched to a smaller value at the reference distance (A).
  • the wall surface (upper solid line) whose target is a large reflecting surface is detected in an area closer than the reference distance (A), but a step of 5 cm 90 ° (lower side) whose target is a small reflecting surface.
  • the threshold voltage and the amplification factor are set so that the solid line) is not detected in the region closer than the reference distance (A). Further, the threshold voltage and the amplification factor are set so that any target is detected in a region farther than the reference distance (A).
  • the threshold voltage and amplification factor are set experimentally so that such characteristics can be obtained.
  • the threshold voltage is set to increase stepwise and monotonously in a region closer than the reference distance (A), and stepwise and monotonously in a region farther than the reference distance (A). Is set to be low.
  • the sensitivity is set so that only a target having a large reflection surface is detected in an area closer than the reference distance (A) and any target is detected in an area farther than the reference distance (A). If so, it can be set to any value (threshold voltage or amplification factor).
  • FIG. 4 (A) to FIG. 4 (C), FIG. 5 (A) to FIG. 5 (C), and FIG. 6 (B) when the host vehicle approaches the target as time passes, It indicates whether or not the target has been detected, and indicates that the target has been detected in the area indicated by the solid line.
  • the reference distance (A) is used. Can also be detected from a distant area.
  • FIG. 3 (B) and FIG. 3 (C) a comparative example in the case where the sensitivity is not changed as in the present embodiment is shown in FIG. 3 (B) and FIG. 3 (C).
  • FIG. 3B shows an example in which the sensitivity is set so as not to detect a target having a small reflecting surface such as a step
  • FIG. 3C shows sensitivity for detecting a target having a large reflecting surface at an early stage. An example of setting is shown.
  • the object detection confirmation In a system using an ultrasonic sonar, in order to ensure the accuracy of the detection, it is common to determine the object detection confirmation by detecting a plurality of times (for example, three times).
  • sensitivity is set as shown in FIG. 3 (B)
  • the wall and step can be identified as shown in FIG. 4 (B).
  • a wall cannot be detected unless it is close to a certain distance. For this reason, it may take more time to finalize the detection result and the necessary control may be delayed.
  • the target is a step that does not need to avoid a collision, the step is not detected as shown in FIG. .
  • the configuration of the present embodiment has an advantage compared to the above example.
  • it is necessary to avoid a collision, but it is advantageous when detecting a ⁇ 400 pole that is a target having a smaller reflecting surface than the wall surface.
  • avoidance processing for avoiding a vehicle collision using the detection result of the sound wave sensor 10 will be described with reference to FIG. Although this process is a process for avoiding a collision of a vehicle, the object is to make it possible to reduce the impact at the minimum even if the collision cannot be avoided.
  • the detection result of the target by the sound wave sensor 10 is acquired (S310). Then, it is determined whether or not a target has been detected (S320). In this process, even if the target is not detected in the current avoidance process, if the target is detected within a certain time (for example, within 1.0 seconds) (that the target has been detected within a certain time) Is recorded in the memory 42), the processing in S320 treats the target as detected.
  • the avoidance process is terminated. If the target is not detected (S320: NO), the avoidance process is terminated. If the target has been detected (S320: YES), the fact that the target has been detected is recorded in the memory 42 (S330). However, if the target is not detected in the current process, the process of S330 is omitted.
  • the degree of risk is determined (S340).
  • the degree of danger is uniquely determined by a map or a mathematical formula prepared in advance by comprehensively considering the speed and acceleration of the host vehicle, the distance to the target, and the like. If the degree of risk is less than a predetermined reference value (S340: NO), the avoidance process is terminated.
  • the distance to the target is compared with the reference distance (S350).
  • the reference distance is a distance corresponding to the specified time used for the determination in the process of S130.
  • the preparation for applying the brake indicates that the brake actuator 50 is operated to the extent that the brake is not applied, and the brake can be immediately applied when the brake is applied, for example, the brake pad is brought close to the brake disk.
  • the calculation unit 11 of the sound wave sensor 10 is within a distance range in which a plurality of targets having different reflection surface sizes can be identified after transmitting the sound wave.
  • a reflected wave after the specified time (corresponding time) corresponding to the reference distance has elapsed timing close enough to be considered to be the same as or simultaneously with the specified time and within a distance range where the target can be identified
  • Set a higher sensitivity the presence / absence of the target and the distance to the target are determined by comparing the reception level of the reflected wave obtained by reflecting the transmitted sound wave on the target with a preset threshold value.
  • a distance detection system 1 since sensitivity is increased in a region farther than the reference distance, it is possible to detect both a small reflection surface and a large reflection surface. In addition, in the region closer than the reference distance, the sensitivity is lowered, so that a small reflection surface is not detected, and a large reflection surface can be detected. Therefore, a plurality of targets can be identified by detecting a change between a state where the target can be detected and a state where the target cannot be detected in a process in which the distance to the target changes with the reference distance interposed therebetween.
  • the calculation unit 11 of the sound wave sensor 10 sets the sensitivity in a stepwise manner.
  • the sensitivity stepwise that is, abruptly changing the sensitivity.
  • the sensitivity is preferably changed by, for example, about 6 dB or more.
  • the calculation unit 11 of the sound wave sensor 10 monotonously decreases the threshold value after the lapse of the specified time. Even in this case, it is possible to easily detect a target having a reference distance or more.
  • the collision avoidance control unit 40 (CPU 41) prepares for braking when the target is detected at a reference distance or more, and when the target is detected at a distance less than the reference distance. The braking is applied to the vehicle.
  • Embodiments of the present disclosure are not limited to the above-described embodiments, and may take various forms as long as they belong to the technical scope of the present disclosure.
  • control is performed to apply braking when the target is less than the reference distance in a state where the target is recognized above the reference distance, but instead of control such as braking or the like In addition to the above control, a warning or the like may be notified.
  • the sound wave sensor 10 in the present embodiment corresponds to a distance detection device in the present disclosure.
  • the process of S170 corresponds to a target determination apparatus referred to in the present disclosure
  • the processes of S130 to S160 correspond to a sensitivity change apparatus referred to in the present disclosure.
  • the processes of S140 and S160 correspond to the threshold value changing device referred to in the present disclosure
  • the process of S360 corresponds to the braking application execution device referred to in the present disclosure
  • the process of S370 corresponds to the braking application preparation device referred to in the present disclosure.

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

Abstract

A distance detection device (10) for detecting the distance to a target by transceiving sound waves is provided with: a target assessment device (S170) for assessing the existence of a target and the distance to the target by comparing a threshold value set in advance and the level at which reflected waves obtained by transmitted-sound waves being reflected from the target are received; and sensitivity modification devices (S130 to S160) for setting the sensitivity at which the target assessment device obtains reflected waves to be higher after a time that corresponds to a reference distance has elapsed after transmission of the sound waves, the reference distance being within a distance range in which a plurality of targets having different sizes of sound-wave reflection surfaces can be identified.

Description

距離検出装置、距離検出方法、およびそのための持続的有形コンピュータ読み取り媒体Distance detection device, distance detection method, and persistent tangible computer readable medium therefor 関連出願の相互参照Cross-reference of related applications
　本開示は、２０１２年１０月１９日に出願された日本出願番号２０１２－２３１８５３号に基づくもので、ここにその記載内容を援用する。 This disclosure is based on Japanese Patent Application No. 2012-231853 filed on October 19, 2012, the contents of which are incorporated herein by reference.
　本開示は、音波を送受信することによって物標までの距離を検出する距離検出装置、距離検出方法、および距離検出用持続的有形コンピュータ読み取り媒体に関するものである。 The present disclosure relates to a distance detection device that detects a distance to a target by transmitting and receiving sound waves, a distance detection method, and a continuous tangible computer-readable medium for distance detection.
　距離検出装置として、ドップラー効果を利用して、移動物と静止物とを識別するものが知られている（例えば、特許文献１参照）。 As a distance detection device, a device that distinguishes a moving object from a stationary object using the Doppler effect is known (for example, see Patent Document 1).
　しかしながら、上記距離検出装置では、例えば、小さな段差と壁面というような、異なる静止物を識別することが難しいという問題点があった。 However, the distance detection device has a problem that it is difficult to distinguish different stationary objects such as small steps and wall surfaces.
特開２０１０－１３９３３０号公報JP 2010-139330 A
　本開示は、複数の静止物を識別できる、音波を送受信することによって物標までの距離を検出する距離検出装置、距離検出方法および距離検出用持続的有形コンピュータ読み取り媒体を提供することを目的とする。 It is an object of the present disclosure to provide a distance detection device, a distance detection method, and a continuous tangible computer-readable medium for distance detection that can identify a plurality of stationary objects and detect a distance to a target by transmitting and receiving sound waves. To do.
　本開示の第一の態様において、音波を送受信することによって物標までの距離を検出する距離検出装置は、送信した音波が物標に反射して得られた反射波の受信レベルと予め設定された閾値とを比較することによって物標の有無および物標までの距離を判定する物標判定装置と、前記音波を送信してから、音波の反射面の大きさが異なる複数の物標を識別可能な距離範囲内である基準距離に対応する対応時間が経過後において、前記物標判定装置が反射波を得るための感度をより高く設定する感度変更装置とを備えている。 In the first aspect of the present disclosure, a distance detection device that detects a distance to a target by transmitting and receiving sound waves is preset with a reception level of a reflected wave obtained by reflecting the transmitted sound waves on the target. A target determination device that determines the presence or absence of a target and a distance to the target by comparing the threshold values with each other, and a plurality of targets having different reflection surface sizes after transmitting the sound wave And a sensitivity changing device that sets a higher sensitivity for the target determination device to obtain a reflected wave after a corresponding time corresponding to a reference distance within a possible distance range has elapsed.
　このような距離検出装置によれば、基準距離よりも遠い領域では、感度を高くしているので、反射面の小さなもの（反射率の小さなもの）および反射面の大きなもの（反射率の大きなもの）の両方を検出することができる。また、基準距離よりも近い領域では、感度を低くしているので、反射面の小さなものは検出されず、かつ反射面の大きなものは検出することができる。よって、物標までの距離が基準距離を挟んで変化する過程で、物標が検出できる状態と検出できない状態との変化を検出することで、複数の物標を識別することができる。特にソナーの検出情報に応じてブレーキをかけるシステムなど、検出の正確さとレスポンスの両方を要求されるシステムにおいて有用である。 According to such a distance detection device, the sensitivity is increased in a region farther than the reference distance, so that the reflective surface is small (low reflectance) and the reflective surface is large (high reflectance). ) Both can be detected. In addition, in the region closer than the reference distance, the sensitivity is lowered, so that a small reflection surface is not detected, and a large reflection surface can be detected. Therefore, a plurality of targets can be identified by detecting a change between a state where the target can be detected and a state where the target cannot be detected in a process in which the distance to the target changes with the reference distance interposed therebetween. This is particularly useful in a system that requires both detection accuracy and response, such as a system that applies a brake according to detection information of a sonar.
　したがって、基準距離以上から基準距離未満に接近した物標が、例えば、小さな段差であるか、壁面であるか等、音波の反射面の大きさが異なる複数の物標を良好に識別することができる。 Therefore, it is possible to satisfactorily identify a plurality of targets having different sizes of sound wave reflection surfaces, such as whether a target approaching the reference distance or more and less than the reference distance is a small step or a wall surface, for example. it can.
　本開示の第二の態様において、コンピュータによって実施される当該命令を備える距離検出用持続的有形コンピュータ読み取り媒体は、第一の態様における距離検出装置の各装置を構成するコンピュータ実施方法を含む。 In the second aspect of the present disclosure, the persistent tangible computer readable medium for distance detection provided with the computer-implemented instructions includes a computer-implemented method that configures each device of the distance detection apparatus in the first aspect.
　上記のコンピュータ読み取り媒体は、検出の正確さとレスポンスの両方を要求されるシステムにおいて有用である。したがって、基準距離以上から基準距離未満に接近した物標が、例えば、小さな段差であるか、壁面であるか等、音波の反射面の大きさが異なる複数の物標を良好に識別することができる。 The above computer-readable medium is useful in a system that requires both detection accuracy and response. Therefore, it is possible to satisfactorily identify a plurality of targets having different sizes of sound wave reflection surfaces, such as whether a target approaching the reference distance or more and less than the reference distance is a small step or a wall surface, for example. it can.
　本開示の第三の態様において、音波を送受信することによって物標までの距離を検出する距離検出方法は、音波を送信し、送信した音波が物標に反射して得られた反射波を受信し、反射波の受信レベルと予め設定された閾値とを比較することで、物標の有無および物標までの距離を判定し、前記音波を送信してから、対応時間が経過後において、反射波を受信する感度をより高く設定することを備える。対応時間は、音波の反射面の大きさが異なる複数の物標を識別可能な距離範囲内である基準距離に対応する。 In the third aspect of the present disclosure, a distance detection method for detecting a distance to a target by transmitting and receiving sound waves transmits the sound waves, and receives the reflected waves obtained by reflecting the transmitted sound waves on the targets. Then, by comparing the reception level of the reflected wave with a preset threshold value, the presence / absence of the target and the distance to the target are determined, and the reflected sound is reflected after the corresponding time has elapsed since the sound wave was transmitted. Setting the sensitivity to receive waves higher. The corresponding time corresponds to a reference distance that is within a distance range in which a plurality of targets having different acoustic wave reflection surface sizes can be identified.
　上記の距離検出方法は、検出の正確さとレスポンスの両方を要求されるシステムにおいて有用である。したがって、基準距離以上から基準距離未満に接近した物標が、例えば、小さな段差であるか、壁面であるか等、音波の反射面の大きさが異なる複数の物標を良好に識別することができる。 The distance detection method described above is useful in a system that requires both detection accuracy and response. Therefore, it is possible to satisfactorily identify a plurality of targets having different sizes of sound wave reflection surfaces, such as whether a target approaching the reference distance or more and less than the reference distance is a small step or a wall surface, for example. it can.
　本開示についての上記目的およびその他の目的、特徴や利点は、添付の図面を参照しながら下記の詳細な記述により、より明確になる。その図面は、
図1は、本開示の距離検出システムの概略構成を示す説明図であり、 図２は、音波センサ１０の演算部１１が実行する検出処理を示すフローチャートであり、 図３（Ａ）から図３（Ｃ）は、各種閾値に対応する反射波強度を示すグラフであり、 図４（Ａ）から図４（Ｃ）は、物標が壁面である場合の反射波強度を示すグラフであり、 図５（Ａ）から図５（Ｃ）は、物標が段差である場合の反射波強度を示すグラフであり、 図６（Ａ）から図６（Ｂ）は、物標がφ４００ポールである場合の反射波強度を示すグラフであり、 図７は、衝突回避制御部のＣＰＵが実行する回避処理を示すフローチャートである。 The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings. The drawing
FIG. 1 is an explanatory diagram showing a schematic configuration of a distance detection system of the present disclosure, FIG. 2 is a flowchart showing a detection process executed by the calculation unit 11 of the sound wave sensor 10. 3 (A) to 3 (C) are graphs showing reflected wave intensities corresponding to various threshold values, 4 (A) to 4 (C) are graphs showing the reflected wave intensity when the target is a wall surface, FIGS. 5A to 5C are graphs showing the reflected wave intensity when the target is a step, FIGS. 6A to 6B are graphs showing the reflected wave intensity when the target is a φ400 pole, FIG. 7 is a flowchart showing avoidance processing executed by the CPU of the collision avoidance control unit.
　以下に本開示にかかる実施の形態を図面と共に説明する。 Embodiments according to the present disclosure will be described below with reference to the drawings.
　［本実施形態の構成］
　本開示が適用された距離検出システム１は、例えば乗用車等の車両に搭載されており、この車両（自車両）の前方や後方に位置する壁面や段差等の障害物を検出し、車両の走行に支障がある場合（例：壁面）に、制動等の制御を行うシステムである。距離検出システム１は、図１に示すように、音波センサ１０と、ソナー制御部３０と、衝突回避制御部４０と、ブレーキアクチュエータ５０と、を備えている。 [Configuration of this embodiment]
The distance detection system 1 to which the present disclosure is applied is mounted on a vehicle such as a passenger car, for example, and detects obstacles such as a wall surface and a step located in front of or behind the vehicle (own vehicle), and the vehicle travel This is a system that performs control such as braking when there is a hindrance (eg wall surface). As shown in FIG. 1, the distance detection system 1 includes a sound wave sensor 10, a sonar control unit 30, a collision avoidance control unit 40, and a brake actuator 50.
　そして、音波センサ１０およびソナー制御部３０は、例えばＬＩＮプロトコルで通信が実施される通信線４で接続されており、ソナー制御部３０、衝突回避制御部４０、およびブレーキアクチュエータ５０は、例えばＣＡＮプロトコルで通信が実施される通信線５で接続されている。 The sonic sensor 10 and the sonar control unit 30 are connected via a communication line 4 that performs communication using, for example, the LIN protocol. The sonar control unit 30, the collision avoidance control unit 40, and the brake actuator 50 include, for example, the CAN protocol. The communication line 5 is used for communication.
　音波センサ１０は、超音波等の音波を送受信することによって音波を反射した物標までの距離を検出する周知の音波センサとしての機能を備えている。特に、本実施形態の音波センサ１０は、検出する物標の距離に応じて感度を変更する機能を備えている。なお、感度を変更する機能については後述する。 The sound wave sensor 10 has a function as a well-known sound wave sensor that detects a distance to a target that reflects sound waves by transmitting and receiving sound waves such as ultrasonic waves. In particular, the sound wave sensor 10 of the present embodiment has a function of changing the sensitivity according to the distance of the target to be detected. A function for changing the sensitivity will be described later.
　音波センサ１０は、演算部１１と、送受信部１２と、第１増幅部１３と、可変増幅部１４と、第２増幅部１５と、比較部１６と、閾電圧生成部１７と、通信部１８とを備えている。 The sonic sensor 10 includes a calculation unit 11, a transmission / reception unit 12, a first amplification unit 13, a variable amplification unit 14, a second amplification unit 15, a comparison unit 16, a threshold voltage generation unit 17, and a communication unit 18. And.
　演算部１１は、ＣＰＵ１１ａやメモリ１１ｂ等を備えたコンピュータとして構成され、音波センサ１０を構成する各部に対して各種指令を送信する。なお、演算部１１は、後述する検出処理等の処理を実施する。また、メモリ１１ｂには、本開示でいう距離検出プログラムが格納されており、ＣＰＵ１１ａによって実行される。 The calculation unit 11 is configured as a computer including a CPU 11a, a memory 11b, and the like, and transmits various commands to each unit constituting the acoustic wave sensor 10. In addition, the calculating part 11 implements processes, such as a detection process mentioned later. The memory 11b stores a distance detection program referred to in the present disclosure and is executed by the CPU 11a.
　送受信部１２は、演算部１１からの指令に応じて音波を送信し、物標によるその反射波を受信する。そして、反射波の受信レベルの大きさに応じて信号を生成し、第１増幅部に送る。なお、送受信部１２は、例えば、圧電素子から構成されている。 The transmission / reception unit 12 transmits a sound wave in response to a command from the calculation unit 11 and receives a reflected wave from the target. And a signal is produced | generated according to the magnitude | size of the reception level of a reflected wave, and it sends to a 1st amplifier. In addition, the transmission / reception part 12 is comprised from the piezoelectric element, for example.
　第１増幅部１３および第２増幅部１５は、アンプ等の増幅回路から構成されている。第１増幅部１３は、送受信部１２にて出力された信号を所定の増幅率で増幅する。 The first amplifying unit 13 and the second amplifying unit 15 are configured by an amplifier circuit such as an amplifier. The first amplification unit 13 amplifies the signal output from the transmission / reception unit 12 with a predetermined amplification factor.
　可変増幅部１４は、演算部１１によってその都度設定された任意の増幅率で第１増幅部１３から出力された信号を増幅する。そして、第２増幅部１５は、可変増幅部１４にて出力された信号を所定の増幅率で増幅する。 The variable amplifying unit 14 amplifies the signal output from the first amplifying unit 13 at an arbitrary amplification factor set by the arithmetic unit 11 each time. The second amplifying unit 15 amplifies the signal output from the variable amplifying unit 14 with a predetermined amplification factor.
　閾電圧生成部１７は、演算部１１による指令に従って比較用の閾電圧を生成する。そして比較部１６は、閾電圧生成部１７によって生成された閾電圧と、第２増幅部１５にて出力された信号の電圧とを比較し、信号の電圧が閾電圧を超えたときに演算部１１に信号を出力する。 The threshold voltage generator 17 generates a threshold voltage for comparison in accordance with a command from the calculator 11. The comparison unit 16 compares the threshold voltage generated by the threshold voltage generation unit 17 with the voltage of the signal output from the second amplification unit 15, and when the signal voltage exceeds the threshold voltage, the calculation unit 11 outputs a signal.
　演算部１１では、比較部１６からの信号を受信したタイミングに従って、音波を反射した物標が存在する距離を演算する。なお、演算部１１は、物標までの距離の演算結果を通信部１８および通信線４を介してソナー制御部３０に対して送信する。ただし、通信部１８（後述する通信部３８，４８も同様）は、通信線４，５を介して通信を実施する周知の通信モジュールとして構成されている。 The computing unit 11 computes the distance at which the target that reflected the sound wave exists according to the timing at which the signal from the comparing unit 16 is received. The calculation unit 11 transmits the calculation result of the distance to the target to the sonar control unit 30 via the communication unit 18 and the communication line 4. However, the communication unit 18 (the same applies to communication units 38 and 48 described later) is configured as a known communication module that performs communication via the communication lines 4 and 5.
　次に、ソナー制御部３０は、ソナー制御部３０は、ＣＰＵ３１と、メモリ３２と、通信部３８とを備えている。ＣＰＵ３１は、メモリ３２に格納されたプログラムに応じて処理を実施し、具体的には、音波センサ１０に対する設定等、音波センサ１０を制御する処理と、物標までの距離の演算結果を衝突回避制御部４０に送信する処理とを実施する。 Next, the sonar control unit 30 includes a CPU 31, a memory 32, and a communication unit 38. The CPU 31 performs processing according to the program stored in the memory 32. Specifically, the CPU 31 controls the acoustic sensor 10 such as setting for the acoustic sensor 10, and the collision avoidance of the calculation result of the distance to the target. Processing to be transmitted to the control unit 40 is performed.
　また、衝突回避制御部４０は、物標の検出結果に応じてブレーキアクチュエータ５０等の被制御対象を制御する機能を有する。衝突回避制御部４０は、ＣＰＵ４１と、メモリ４２と、通信部４８とを備えている。これらのＣＰＵ４１、メモリ４２、通信部４８は、ソナー制御部３０に備えられたＣＰＵ３１、メモリ３２、通信部３８と同様のハードウェア構成である。なお、衝突回避制御部４０のＣＰＵ４１は、後述する回避処理等の処理を行う。 Also, the collision avoidance control unit 40 has a function of controlling the controlled object such as the brake actuator 50 according to the detection result of the target. The collision avoidance control unit 40 includes a CPU 41, a memory 42, and a communication unit 48. The CPU 41, the memory 42, and the communication unit 48 have the same hardware configuration as the CPU 31, the memory 32, and the communication unit 38 provided in the sonar control unit 30. In addition, CPU41 of the collision avoidance control part 40 performs processes, such as an avoidance process mentioned later.
　［本実施形態の処理］
　このような距離検出システム１において、音波センサ１０の演算部１１（ＣＰＵ１１ａ）は、図２に示す検出処理を実施する。検出処理は、物標までの距離を、感度を変更しつつ検出する処理である。 [Process of this embodiment]
In such a distance detection system 1, the calculation unit 11 (CPU 11a) of the sound wave sensor 10 performs the detection process shown in FIG. The detection process is a process for detecting the distance to the target while changing the sensitivity.
　詳細には、図２に示すように、まず、音波の送信タイミングになったか否かを判定する（Ｓ１１０）。ここで、音波は予め設定された周期（例えば１００ｍｓ）毎に送信されるよう設定されており、この処理では、前回音波が送信されてからの経過時間を監視することによって送信タイミングになったか否かを判定する。 Specifically, as shown in FIG. 2, first, it is determined whether or not the sound wave transmission timing has come (S110). Here, the sound wave is set to be transmitted at a preset period (for example, 100 ms). In this process, whether or not the transmission timing is reached by monitoring the elapsed time since the last sound wave was transmitted. Determine whether.
　送信タイミングになっていなければ（Ｓ１１０：ＮＯ）、Ｓ１１０の処理を繰り返す。また、送信タイミングになっていれば（Ｓ１１０：ＹＥＳ）、送受信部１２を介して音波を送信する（Ｓ１２０）。この処理では例えば０．２ｍｓだけ音波を送信する。 If the transmission timing is not reached (S110: NO), the process of S110 is repeated. Moreover, if it is a transmission timing (S110: YES), a sound wave will be transmitted via the transmission / reception part 12 (S120). In this process, for example, a sound wave is transmitted for 0.2 ms.
　続いて、電波の送信後、予め設定された規定時間（対応時間）が経過したか否かを判定する（Ｓ１３０）。ここで、規定時間とは、音波を送信してから、音波の反射面の大きさが異なる複数の物標を識別可能な距離範囲内である基準距離に対応する時間を表し、例えば、基準距離を２ｍとする場合には、約１２ｍｓとなる。 Subsequently, it is determined whether or not a predetermined time (corresponding time) set in advance has elapsed after the transmission of the radio wave (S130). Here, the specified time represents a time corresponding to a reference distance within a distance range in which a plurality of targets having different sizes of sound wave reflection surfaces can be identified after the sound wave is transmitted. For example, the reference distance When the length is 2 m, it is about 12 ms.
　規定時間が経過していなければ（Ｓ１３０：ＮＯ）、音波センサ１０の感度を相対的に低く設定する（Ｓ１４０）。詳細には、可変増幅部１４による増幅率を相対的に低く設定するとともに、閾電圧生成部１７に生成させる閾電圧を相対的に高く設定することで、反射面の小さな段差等は検出されず、かつ反射面の大きな壁面等は検出することができるようにする。このような処理が終了すると、後述するＳ１７０の処理に移行する。 If the specified time has not elapsed (S130: NO), the sensitivity of the sound wave sensor 10 is set relatively low (S140). Specifically, by setting the amplification factor by the variable amplification unit 14 to be relatively low and setting the threshold voltage to be generated by the threshold voltage generation unit 17 to be relatively high, a small step or the like on the reflection surface is not detected. In addition, a wall surface having a large reflection surface can be detected. When such a process is completed, the process proceeds to S170 described later.
　また、Ｓ１３０の処理において、規定時間が経過していれば（Ｓ１３０：ＹＥＳ）、音波を送信してから予め設定された計測終了時間が経過したか否かを判定する（Ｓ１５０）。ここで、計測終了時間は、音波の送信を開始してから必要な距離を検出終了するまでの時間（例えば３０ｍｓ：５ｍ相当など）が設定される。 In the process of S130, if the specified time has elapsed (S130: YES), it is determined whether or not a preset measurement end time has elapsed since the sound wave was transmitted (S150). Here, as the measurement end time, a time (for example, 30 ms: equivalent to 5 m) from the start of transmission of sound waves to the end of detection of a necessary distance is set.
　計測終了時間が経過していなければ（Ｓ１５０：ＮＯ）、音波センサ１０の感度を相対的に高く設定する（Ｓ１６０）。詳細には、可変増幅部１４による増幅率を相対的に高く設定するとともに、閾電圧生成部１７に生成させる閾電圧を相対的に低く設定することで、反射面の小さなものおよび反射面の大きなものの両方を検出することができるようにする。 If the measurement end time has not elapsed (S150: NO), the sensitivity of the sound wave sensor 10 is set relatively high (S160). Specifically, by setting the amplification factor by the variable amplifying unit 14 to be relatively high and setting the threshold voltage to be generated by the threshold voltage generating unit 17 to be relatively low, one having a small reflecting surface and a large reflecting surface. Be able to detect both things.
　続いて、反射波に基づく信号が閾電圧を超えたときに比較部１６から送信される信号を検出し、このときの音波を送信してからの時間に基づいて物標までの距離を演算部１１内のメモリに記録し（Ｓ１７０）、Ｓ１３０の処理に移行する。また、Ｓ１５０の処理にて、計測終了時間が経過していれば（Ｓ１５０：ＹＥＳ）、検出処理を終了する。 Subsequently, when the signal based on the reflected wave exceeds the threshold voltage, the signal transmitted from the comparison unit 16 is detected, and the distance to the target is calculated based on the time after transmitting the sound wave at this time. 11 (S170), and the process proceeds to S130. If the measurement end time has elapsed in S150 (S150: YES), the detection process is terminated.
　ここで、本実施形態では、図３（Ａ）に示すように可変増幅部１４による増幅率（ゲイン）および閾電圧生成部１７に生成させる閾電圧（閾値）を設定する。すなわち、増幅率については、基準距離（Ａ）にてより高いゲインに切り替え、閾電圧については、基準距離（Ａ）にてより小さな値に切り替える。 Here, in this embodiment, as shown in FIG. 3A, the amplification factor (gain) by the variable amplification unit 14 and the threshold voltage (threshold) to be generated by the threshold voltage generation unit 17 are set. That is, the gain is switched to a higher gain at the reference distance (A), and the threshold voltage is switched to a smaller value at the reference distance (A).
　このとき、反射面が大きな物標である壁面（上側の実線）は、基準距離（Ａ）よりも近い領域で検出されるが、反射面が小さな物標である５ｃｍ９０°の段差（下側の実線）は、基準距離（Ａ）よりも近い領域では検出されないよう閾電圧および増幅率が設定されている。また、基準距離（Ａ）よりも遠い領域では、何れの物標も検出されるよう閾電圧および増幅率が設定されている。 At this time, the wall surface (upper solid line) whose target is a large reflecting surface is detected in an area closer than the reference distance (A), but a step of 5 cm 90 ° (lower side) whose target is a small reflecting surface. The threshold voltage and the amplification factor are set so that the solid line) is not detected in the region closer than the reference distance (A). Further, the threshold voltage and the amplification factor are set so that any target is detected in a region farther than the reference distance (A).
　なお、閾電圧や増幅率については、このような特性が得られるよう、実験的に設定される。また、図３（Ａ）において閾電圧は、基準距離（Ａ）よりも近い領域においては段階的にかつ単調に高くなるよう設定し、基準距離（Ａ）よりも遠い領域において段階的にかつ単調に低くなるよう設定している。このように感度については、基準距離（Ａ）よりも近い領域で反射面が大きな物標だけが検出され、かつ基準距離（Ａ）よりも遠い領域で何れの物標も検出されるよう設定されていれば、任意の値（閾電圧や増幅率）に設定できる。 The threshold voltage and amplification factor are set experimentally so that such characteristics can be obtained. In FIG. 3A, the threshold voltage is set to increase stepwise and monotonously in a region closer than the reference distance (A), and stepwise and monotonously in a region farther than the reference distance (A). Is set to be low. As described above, the sensitivity is set so that only a target having a large reflection surface is detected in an area closer than the reference distance (A) and any target is detected in an area farther than the reference distance (A). If so, it can be set to any value (threshold voltage or amplification factor).
　ここで、図４（Ａ）から図４（Ｃ）、図５（Ａ）から図５（Ｃ）、図６（Ｂ）では、自車両が時間の経過とともに物標に接近する際において、物標を検出できているか否かを示し、実線で示す領域において物標を検出できていることを示す。このように設定された音波センサ１０では、物標が衝突を回避する必要がある壁（反射面が大きい物標）である場合、図４（Ａ）に示すように、基準距離（Ａ）よりも遠い領域から検出することができる。 Here, in FIG. 4 (A) to FIG. 4 (C), FIG. 5 (A) to FIG. 5 (C), and FIG. 6 (B), when the host vehicle approaches the target as time passes, It indicates whether or not the target has been detected, and indicates that the target has been detected in the area indicated by the solid line. In the acoustic wave sensor 10 set in this way, when the target is a wall (a target having a large reflecting surface) that needs to avoid a collision, as shown in FIG. 4A, the reference distance (A) is used. Can also be detected from a distant area.
　したがって、衝突を回避する必要がある壁が基準距離（Ａ）よりも接近したときに、速やかに衝突を回避するための制御を実施することができる。また、物標が衝突を回避する必要がない小さな段差（反射面が小さい物標）である場合、図５（Ａ）に示すように、物標が基準距離（Ａ）よりも接近したときに、検出されなくなる。したがって、誤って衝突を回避する制御を行うことがない。 Therefore, when a wall that needs to avoid a collision is closer than the reference distance (A), a control for quickly avoiding the collision can be performed. Further, when the target is a small step (a target having a small reflecting surface) that does not need to avoid collision, as shown in FIG. 5A, when the target is closer than the reference distance (A) , No longer detected. Therefore, control for avoiding a collision by mistake is not performed.
　ここで、本実施形態のように感度を変更しない場合の比較例を図３（Ｂ）および図３（Ｃ）に示す。図３（Ｂ）は、段差等の反射面が小さい物標を検出しないように感度を設定した例を示し、図３（Ｃ）は、早期に反射面が大きい物標を検出するための感度を設定した例を示す。 Here, a comparative example in the case where the sensitivity is not changed as in the present embodiment is shown in FIG. 3 (B) and FIG. 3 (C). FIG. 3B shows an example in which the sensitivity is set so as not to detect a target having a small reflecting surface such as a step, and FIG. 3C shows sensitivity for detecting a target having a large reflecting surface at an early stage. An example of setting is shown.
　超音波ソナーを用いたシステムでは、その検出の正確さを確保するために、複数回数（例えば３回）の検出で物体検出確定を判定するのが一般的である。図３（Ｂ）に示すような感度を設定した場合において、物標が衝突を回避する必要がある壁である場合には、図４（Ｂ）に示すように、壁と段差とを識別可能な距離まで接近しなければ壁を検出することができない。このため、検出結果の確定等にさらに時間が掛かり、必要な制御が遅れる虞がある。なお、この場合、物標が衝突を回避する必要がない段差の場合には、図５（Ｂ）に示すように、段差が検出されることがないので誤った制御が実施される虞はない。 In a system using an ultrasonic sonar, in order to ensure the accuracy of the detection, it is common to determine the object detection confirmation by detecting a plurality of times (for example, three times). When sensitivity is set as shown in FIG. 3 (B), if the target is a wall that needs to avoid collision, the wall and step can be identified as shown in FIG. 4 (B). A wall cannot be detected unless it is close to a certain distance. For this reason, it may take more time to finalize the detection result and the necessary control may be delayed. In this case, when the target is a step that does not need to avoid a collision, the step is not detected as shown in FIG. .
　次に、図３（Ｃ）に示すような感度を設定した場合において、物標が衝突を回避する必要がある壁である場合には、図４（Ｃ）に示すように、本実施形態の設定と同様に、早期に壁を検出できるので適切な制御を行うことができる。しかしながら、物標が衝突を回避する必要がない段差の場合には、図５（Ｃ）に示すように、段差との距離が接近しても検出された状態が継続するので、衝突を回避するための必要のない制御が実施される虞がある。 Next, when the sensitivity as shown in FIG. 3C is set, if the target is a wall that needs to avoid collision, as shown in FIG. Similar to the setting, since the wall can be detected at an early stage, appropriate control can be performed. However, in the case where the target does not need to avoid a collision, as shown in FIG. 5C, the detected state continues even if the distance from the step approaches, so the collision is avoided. There is a risk that control that is not necessary for this purpose is performed.
　したがって、本実施形態の構成では、上記の例と比較して優位性があることが確認できた。なお、本実施形態の構成では、衝突を回避する必要があるが壁面よりも反射面が小さい物標であるφ４００ポールを検出する際にも有利である。 Therefore, it was confirmed that the configuration of the present embodiment has an advantage compared to the above example. In the configuration of the present embodiment, it is necessary to avoid a collision, but it is advantageous when detecting a φ400 pole that is a target having a smaller reflecting surface than the wall surface.
　例えば、φ４００ポールを検出する際には、例えば図６（Ａ）に示すような反射波の出力が得られるが、このφ４００ポールに接近する場合には、図６（Ｂ）に示すように、検出・非検出の状態が変化する。つまり、物標までの距離が基準距離（Ａ）よりも遠いときには検出状態となり、基準距離（Ａ）で一旦、非検出状態となるが、再度、検出状態となる。したがって、必要な制御を実施することができる。 For example, when detecting a φ400 pole, for example, an output of a reflected wave as shown in FIG. 6 (A) is obtained, but when approaching this φ400 pole, as shown in FIG. 6 (B), The detection / non-detection status changes. That is, when the distance to the target is farther than the reference distance (A), the detection state is set, and at the reference distance (A), the detection state is temporarily set, but the detection state is set again. Therefore, necessary control can be performed.
　次に、このような音波センサ１０による検出結果を利用して車両の衝突を回避する回避処理について図７を用いて説明する。なお、本処理は、車両の衝突を回避するための処理ではあるが、衝突を回避できなかったとしても、最低限衝突の際の衝撃を軽減させることを可能とさせることを目的とする。 Next, avoidance processing for avoiding a vehicle collision using the detection result of the sound wave sensor 10 will be described with reference to FIG. Although this process is a process for avoiding a collision of a vehicle, the object is to make it possible to reduce the impact at the minimum even if the collision cannot be avoided.
　回避処理では、図７に示すように、まず、音波センサ１０による物標の検出結果を取得する（Ｓ３１０）。そして、物標を検出したか否かを判定する（Ｓ３２０）。この処理では、今回の回避処理において物標が検出されなかったとしても、一定時間以内（例えば１．０秒以内）において物標が検出されていた場合（一定時間以内に物標を検出した旨がメモリ４２に記録されていた場合）には、Ｓ３２０の処理では物標を検出したものとして取り扱う。 In the avoidance process, as shown in FIG. 7, first, the detection result of the target by the sound wave sensor 10 is acquired (S310). Then, it is determined whether or not a target has been detected (S320). In this process, even if the target is not detected in the current avoidance process, if the target is detected within a certain time (for example, within 1.0 seconds) (that the target has been detected within a certain time) Is recorded in the memory 42), the processing in S320 treats the target as detected.
　物標を検出していなければ（Ｓ３２０：ＮＯ）、回避処理を終了する。また、物標を検出していれば（Ｓ３２０：ＹＥＳ）、物標を検出した旨をメモリ４２に記録する（Ｓ３３０）。ただし、今回の処理において物標を検出していない場合には、Ｓ３３０の処理を省略する。 If the target is not detected (S320: NO), the avoidance process is terminated. If the target has been detected (S320: YES), the fact that the target has been detected is recorded in the memory 42 (S330). However, if the target is not detected in the current process, the process of S330 is omitted.
　続いて、危険度の判定を行う（Ｓ３４０）。ここで、危険度は、自車両の速度や加速度、物標までの距離等を総合的に勘案して予め準備されたマップや数式によって一義的に求められる。危険度が所定の基準値未満であれば（Ｓ３４０：ＮＯ）、回避処理を終了する。 Subsequently, the degree of risk is determined (S340). Here, the degree of danger is uniquely determined by a map or a mathematical formula prepared in advance by comprehensively considering the speed and acceleration of the host vehicle, the distance to the target, and the like. If the degree of risk is less than a predetermined reference value (S340: NO), the avoidance process is terminated.
　また、危険度が基準値以上であれば（Ｓ３４０：ＹＥＳ）、物標までの距離と基準距離とを比較する（Ｓ３５０）。なお、ここでの基準距離は、Ｓ１３０の処理において判定に利用した規定時間に対応する距離である。 If the degree of risk is equal to or higher than the reference value (S340: YES), the distance to the target is compared with the reference distance (S350). Here, the reference distance is a distance corresponding to the specified time used for the determination in the process of S130.
　物標までの距離が基準距離未満であれば（Ｓ３５０：ＹＥＳ）、ブレーキアクチュエータ５０を介して車両に制動を加える制動付与を実施し（Ｓ３６０）、回避処理を終了する。また、物標までの距離が基準距離以上であれば（Ｓ３５０：ＮＯ）、制動付与の準備を行う（Ｓ３７０）。 If the distance to the target is less than the reference distance (S350: YES), braking is applied to apply braking to the vehicle via the brake actuator 50 (S360), and the avoidance process is terminated. If the distance to the target is greater than or equal to the reference distance (S350: NO), preparation for braking is performed (S370).
　ここで、制動付与の準備とは、ブレーキアクチュエータ５０を制動付与しない程度に作動させ、例えばブレーキパッドをブレーキディスクに近接させるなど、制動付与を行う際に直ちに制動できるようにすることを示す。 Here, the preparation for applying the brake indicates that the brake actuator 50 is operated to the extent that the brake is not applied, and the brake can be immediately applied when the brake is applied, for example, the brake pad is brought close to the brake disk.
　このような処理が終了すると、回避処理を終了する。 When the process is completed, the avoidance process ends.
　［本実施形態による効果］
　以上のように詳述した距離検出システム１において音波センサ１０の演算部１１は、音波を送信してから、音波の反射面の大きさが異なる複数の物標を識別可能な距離範囲内である基準距離に対応する規定時間（対応時間）が経過後（規定時間と同時または同時とみなせる程度に近接するタイミング、かつ物標を識別可能な距離範囲内に対応するタイミング）において反射波を得るための感度をより高く設定する。そして、送信した音波が物標に反射して得られた反射波の受信レベルと予め設定された閾値とを比較することによって物標の有無および物標までの距離を判定する。 [Effects of this embodiment]
In the distance detection system 1 described in detail above, the calculation unit 11 of the sound wave sensor 10 is within a distance range in which a plurality of targets having different reflection surface sizes can be identified after transmitting the sound wave. To obtain a reflected wave after the specified time (corresponding time) corresponding to the reference distance has elapsed (timing close enough to be considered to be the same as or simultaneously with the specified time and within a distance range where the target can be identified) Set a higher sensitivity. Then, the presence / absence of the target and the distance to the target are determined by comparing the reception level of the reflected wave obtained by reflecting the transmitted sound wave on the target with a preset threshold value.
　このような距離検出システム１によれば、基準距離よりも遠い領域では、感度を高くしているので、反射面の小さなものおよび反射面の大きなものの両方を検出することができる。また、基準距離よりも近い領域では、感度を低くしているので、反射面の小さなものは検出されず、かつ反射面の大きなものは検出することができる。よって、物標までの距離が基準距離を挟んで変化する過程で、物標が検出できる状態と検出できない状態との変化を検出することで、複数の物標を識別することができる。 According to such a distance detection system 1, since sensitivity is increased in a region farther than the reference distance, it is possible to detect both a small reflection surface and a large reflection surface. In addition, in the region closer than the reference distance, the sensitivity is lowered, so that a small reflection surface is not detected, and a large reflection surface can be detected. Therefore, a plurality of targets can be identified by detecting a change between a state where the target can be detected and a state where the target cannot be detected in a process in which the distance to the target changes with the reference distance interposed therebetween.
　したがって、基準距離以上から基準距離未満に接近した物標が、例えば、小さな段差であるか、壁面であるか等、音波の反射面の大きさが異なる複数の物標を良好に識別することができる。 Therefore, it is possible to satisfactorily identify a plurality of targets having different sizes of sound wave reflection surfaces, such as whether a target approaching the reference distance or more and less than the reference distance is a small step or a wall surface, for example. it can.
　また、上記距離検出システム１において音波センサ１０の演算部１１は、感度を段階的に高く設定する。 Further, in the distance detection system 1, the calculation unit 11 of the sound wave sensor 10 sets the sensitivity in a stepwise manner.
　このような距離検出システム１によれば、感度を段階的に変化させる（つまり、急峻に感度を変更する）ことで、基準距離以上の物標を検出しやすくすることができる。なお、このように感度を段階的に変化させる際には、例えば６ｄＢ程度以上、感度が変化するとよい。 According to such a distance detection system 1, it is possible to easily detect a target having a reference distance or more by changing the sensitivity stepwise (that is, abruptly changing the sensitivity). When the sensitivity is changed stepwise in this way, the sensitivity is preferably changed by, for example, about 6 dB or more.
　さらに、上記距離検出システム１において音波センサ１０の演算部１１は、規定時間の経過後に閾値を単調減少させる。このようにしても、基準距離以上の物標を検出しやすくすることができる。 Further, in the distance detection system 1, the calculation unit 11 of the sound wave sensor 10 monotonously decreases the threshold value after the lapse of the specified time. Even in this case, it is possible to easily detect a target having a reference distance or more.
　また、上記距離検出システム１において衝突回避制御部４０（ＣＰＵ４１）は、基準距離以上において物標が検出された際に車両において制動付与の準備を行い、基準距離未満において物標が検出された際に車両において制動付与を行う。 In the distance detection system 1, the collision avoidance control unit 40 (CPU 41) prepares for braking when the target is detected at a reference distance or more, and when the target is detected at a distance less than the reference distance. The braking is applied to the vehicle.
　すなわち、基準距離未満においては感度を高く設定しているので、概ね全ての物標を識別可能であり、識別結果に応じて制動を付与するための準備を行うことができる。そして、基準距離以上で物標が認識できている状態で基準距離未満になった場合において、物標を認識している場合には制動付与を行う。この際、既に制動付与の準備がされているので、速やかに制動を行うことができる。なお、基準距離以上では、物標を識別することは困難であるが、制動を付与することがないので、誤作動を抑制することができる。 That is, since the sensitivity is set high below the reference distance, almost all targets can be identified, and preparations for applying braking can be made according to the identification results. Then, when the target is less than the reference distance in a state where the target is recognized at the reference distance or more, braking is applied when the target is recognized. At this time, since braking preparation is already prepared, braking can be performed promptly. In addition, although it is difficult to identify a target at a reference distance or more, since no braking is applied, malfunction can be suppressed.
　［その他の実施形態］
　本開示の実施の形態は、上記の実施形態に何ら限定されることはなく、本開示の技術的範囲に属する限り種々の形態を採りうる。 [Other Embodiments]
Embodiments of the present disclosure are not limited to the above-described embodiments, and may take various forms as long as they belong to the technical scope of the present disclosure.
　例えば、上記実施形態においては、基準距離以上で物標が認識できている状態で基準距離未満になった場合に制動付与を行う制御を実施したが、制動等の制御に換えて、或いは制動等の制御に加えて、警報等の報知を行うようにしてもよい。 For example, in the above embodiment, control is performed to apply braking when the target is less than the reference distance in a state where the target is recognized above the reference distance, but instead of control such as braking or the like In addition to the above control, a warning or the like may be notified.
　また、上記実施形態においては、全ての請求項に記載の構成を示したが、請求項２以下に記載の構成は必須の構成でなく、任意に選択的に採用することができる。 In the above-described embodiment, the configurations described in all the claims are shown. However, the configurations described in claims 2 and below are not essential configurations and can be selectively adopted arbitrarily.
　［本実施形態の構成と本開示の装置との関係］
　本実施形態での音波センサ１０は、本開示でいう距離検出装置に相当する。また、本実施形態における処理のうち、Ｓ１７０の処理は本開示でいう物標判定装置に相当し、Ｓ１３０～Ｓ１６０の処理は本開示でいう感度変更装置に相当する。 [Relationship Between Configuration of Present Embodiment and Device of Present Disclosure]
The sound wave sensor 10 in the present embodiment corresponds to a distance detection device in the present disclosure. Of the processes in the present embodiment, the process of S170 corresponds to a target determination apparatus referred to in the present disclosure, and the processes of S130 to S160 correspond to a sensitivity change apparatus referred to in the present disclosure.
　さらに、Ｓ１４０、Ｓ１６０の処理は本開示でいう閾値変更装置に相当し、Ｓ３６０の処理は本開示でいう制動付与実行装置に相当し、Ｓ３７０の処理は本開示でいう制動付与準備装置に相当する。 Furthermore, the processes of S140 and S160 correspond to the threshold value changing device referred to in the present disclosure, the process of S360 corresponds to the braking application execution device referred to in the present disclosure, and the process of S370 corresponds to the braking application preparation device referred to in the present disclosure. .
　本開示は、実施例に準拠して記述されたが、本開示は当該実施例や構造に限定されるものではないと理解される。本開示は、様々な変形例や均等範囲内の変形をも包含する。加えて、様々な組み合わせや形態、さらには、それらに一要素のみ、それ以上、あるいはそれ以下、を含む他の組み合わせや形態をも、本開示の範疇や思想範囲に入るものである。 Although the present disclosure has been described based on the embodiments, it is understood that the present disclosure is not limited to the embodiments and structures. The present disclosure includes various modifications and modifications within the equivalent range. In addition, various combinations and forms, as well as other combinations and forms including only one element, more or less, are within the scope and spirit of the present disclosure.

Claims (6)

  1. 　音波を送受信することによって物標までの距離を検出する距離検出装置（１０）であって、
    　送信した音波が物標に反射して得られた反射波の受信レベルと予め設定された閾値とを比較することによって物標の有無および物標までの距離を判定する物標判定装置（Ｓ１７０）と、
    　前記音波を送信してから、音波の反射面の大きさが異なる複数の物標を識別可能な距離範囲内である基準距離に対応する対応時間が経過後において、前記物標判定装置が反射波を得るための感度をより高く設定する感度変更装置（Ｓ１３０～Ｓ１６０）と、
    　を備えた距離検出装置。     A distance detection device (10) for detecting a distance to a target by transmitting and receiving sound waves,
    A target determination device that determines the presence of the target and the distance to the target by comparing the reception level of the reflected wave obtained by reflecting the transmitted sound wave on the target with a preset threshold (S170). When,
    After the transmission of the sound wave, after the corresponding time corresponding to a reference distance that is within a distance range in which a plurality of targets having different reflection surface sizes of the sound wave can be identified, the target determination device reflects the reflected wave. A sensitivity changing device (S130 to S160) for setting a higher sensitivity to obtain
    A distance detection device comprising:
  2. 　前記感度変更装置は、前記感度を段階的に高く設定する、
    　請求項１に記載の距離検出装置。     The sensitivity changing device sets the sensitivity higher stepwise.
    The distance detection apparatus according to claim 1.
  3. 　前記感度変更装置は、前記対応時間の経過後に前記閾値を単調減少させる閾値変更装置（Ｓ１４０、Ｓ１６０）を備えた、
    　請求項２に記載の距離検出装置。     The sensitivity changing device includes a threshold changing device (S140, S160) that monotonously decreases the threshold after the corresponding time has elapsed.
    The distance detection apparatus according to claim 2.
  4. 　当該距離検出装置は車両に搭載されており、
    　前記基準距離以上において物標が検出された際に、前記車両において制動付与の準備を行う制動付与準備装置（Ｓ３７０）と、
    　前記基準距離未満において物標が検出された際に、前記車両において制動付与を行う制動付与実行装置（Ｓ３６０）と、
    　をさらに備えた請求項１～請求項３の何れか１項に記載の距離検出装置。     The distance detection device is mounted on a vehicle,
    A braking application preparation device (S370) for preparing to apply braking in the vehicle when a target is detected at the reference distance or more;
    A braking application execution device (S360) for applying braking in the vehicle when a target is detected below the reference distance;
    The distance detection device according to any one of claims 1 to 3, further comprising:
  5. 　請求項１～請求項４の何れか１項に記載の距離検出装置の各装置を構成するコンピュータ実施方法を含み、コンピュータによって実施される当該命令を備える距離検出用持続的有形コンピュータ読み取り媒体。 A continuous tangible computer-readable medium for distance detection, comprising a computer-implemented method for configuring each device of the distance detection device according to any one of claims 1 to 4, comprising the instructions executed by the computer.
  6. 　音波を送受信することによって物標までの距離を検出する距離検出方法であって、
    　音波を送信し、
    　送信した音波が物標に反射して得られた反射波を受信し、
    　反射波の受信レベルと予め設定された閾値とを比較することで、物標の有無および物標までの距離を判定し、
    　前記音波を送信してから、対応時間が経過後において、反射波を受信する感度をより高く設定することを備え、
    　対応時間は、音波の反射面の大きさが異なる複数の物標を識別可能な距離範囲内である基準距離に対応する、
    　距離検出方法。     A distance detection method for detecting a distance to a target by transmitting and receiving sound waves,
    Send sound waves,
    Receive the reflected wave obtained by reflecting the transmitted sound wave to the target,
    By comparing the reception level of the reflected wave with a preset threshold value, the presence or absence of the target and the distance to the target are determined,
    Comprising setting the sensitivity to receive the reflected wave higher after a corresponding time has elapsed since transmitting the sound wave;
    The corresponding time corresponds to a reference distance that is within a distance range in which a plurality of targets having different reflection surface sizes of sound waves can be identified.
    Distance detection method.
PCT/JP2013/005278 2012-10-19 2013-09-05 Distance detection device, distance detection method, and persistent tangible computer-readable medium therefor WO2014061192A1 (en)

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Citations (4)

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JPH06300833A (en) * 1993-04-13 1994-10-28 Yanmar Agricult Equip Co Ltd Ultrasonic type device for detecting distance
JPH1183999A (en) * 1997-09-10 1999-03-26 Hironobu Watanabe Device for detecting distance between vehicles
JP2009248706A (en) * 2008-04-04 2009-10-29 Calsonic Kansei Corp Brake device
JP2010256317A (en) * 2009-04-24 2010-11-11 Avermedia Information Inc Ultrasonic reception module, ultrasonic distance measuring system, ultrasonic distance measuring method, and overhead camera

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06300833A (en) * 1993-04-13 1994-10-28 Yanmar Agricult Equip Co Ltd Ultrasonic type device for detecting distance
JPH1183999A (en) * 1997-09-10 1999-03-26 Hironobu Watanabe Device for detecting distance between vehicles
JP2009248706A (en) * 2008-04-04 2009-10-29 Calsonic Kansei Corp Brake device
JP2010256317A (en) * 2009-04-24 2010-11-11 Avermedia Information Inc Ultrasonic reception module, ultrasonic distance measuring system, ultrasonic distance measuring method, and overhead camera

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