JP4832374B2

JP4832374B2 - Warning object detection device, mobile communication terminal, safe driving support system and method

Info

Publication number: JP4832374B2
Application number: JP2007188292A
Authority: JP
Inventors: 崇文徳弘; 貴巳本山; 敏幸高野
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp; Panasonic Holdings Corp
Priority date: 2007-07-19
Filing date: 2007-07-19
Publication date: 2011-12-07
Anticipated expiration: 2027-07-19
Also published as: JP2009026058A

Description

本発明は、無線通信を用いて安全運転支援を行うための警戒対象検出装置、移動通信端末、安全運転支援システムおよび方法に関する。 The present invention relates to a warning object detection device, a mobile communication terminal, a safe driving support system, and a method for performing safe driving support using wireless communication.

従来から、無線通信を利用して、運転中の自車両の周囲に存在する他車両や歩行者などの移動体を検出する方法は、数多く提案されている。例えば、特許文献１に記載されたものは、歩行者などの警戒対象が保持する発信装置から、警戒信号が発信されている一方、車両にはこの警戒信号を受信可能な受信装置が搭載されていて、警戒信号の受信を監視しながら走行し、警戒信号が受信された際には警報を発生して、周囲に歩行者などの警戒対象の存在を運転者に知らせるというものである。 2. Description of the Related Art Conventionally, many methods have been proposed for detecting moving bodies such as other vehicles and pedestrians existing around a driving vehicle using wireless communication. For example, in the device described in Patent Document 1, a warning signal is transmitted from a transmission device held by a warning target such as a pedestrian, while a receiving device capable of receiving the warning signal is mounted on the vehicle. Thus, the vehicle travels while monitoring the reception of the warning signal, and when the warning signal is received, an alarm is generated to notify the driver of the presence of a warning target such as a pedestrian around.

しかし、警戒対象が周囲に存在しているということのみが検出可能であるため、運転者から容易に目視で確認できる警戒対象に対する警報も発生してしまい、運転者にとって煩わしくなってしまう可能性がある。 However, since it is only possible to detect that the alert target exists in the surroundings, an alarm for the alert target that can be easily visually confirmed by the driver is also generated, which may be troublesome for the driver. is there.

さらに、警戒対象の数も判らないため、例えば、前方の障害物の陰から飛び出そうとしている警戒対象が存在するにも関わらず、別の目視できる歩行者の存在を目視で確認して、警報の原因が目視可能な歩行者に対するものであると判断してしまい、事故を防ぐことができないという課題も考えられる。 In addition, since the number of warning targets is not known, for example, there is a warning target that is about to jump out from behind the obstacle in front, but the presence of another visible pedestrian can be confirmed visually to alert It is determined that the cause of the problem is for a pedestrian who can be seen, and an accident cannot be prevented.

そこで、特許文献２に記載されたものは、被検出側移動体は、遮蔽物を容易に回折する低周波電磁波を送信する低周波電磁波送信手段と、遮蔽物を容易に回折しない高周波電磁波を送信する高周波電磁波送信手段とを持ち、一方、検出側移動体は、前記低周波電磁波を受信する低周波電磁波受信手段と、前記高周波電磁波を受信する高周波電磁波受信手段と通信制御回路で構成されており、被検出側移動体は、低周波電磁波送信手段と高周波電磁波送信手段によって、低周波電磁波と高周波電磁波を同時に送信する。 Therefore, the device described in Patent Document 2 is such that the detection-side moving body transmits a low-frequency electromagnetic wave transmitting means that transmits a low-frequency electromagnetic wave that easily diffracts the shielding object, and a high-frequency electromagnetic wave that does not easily diffract the shielding object. The detection-side moving body is composed of a low-frequency electromagnetic wave receiving means for receiving the low-frequency electromagnetic wave, a high-frequency electromagnetic wave receiving means for receiving the high-frequency electromagnetic wave, and a communication control circuit. The detected-side moving body transmits the low-frequency electromagnetic wave and the high-frequency electromagnetic wave simultaneously by the low-frequency electromagnetic wave transmitting means and the high-frequency electromagnetic wave transmitting means.

上記のような状態で、検出側移動体において、低周波電磁波のみが受信される場合は、高周波電磁波は遮蔽物で遮られたと考えられ、被検出側移動体は遮蔽物の陰に隠れて、見通し外の場所に存在すると判断できる。 In the state as described above, when only the low frequency electromagnetic wave is received in the detection side moving body, the high frequency electromagnetic wave is considered to be blocked by the shielding object, and the detection side moving body is hidden behind the shielding object, It can be judged that it exists in a place out of sight.

一方、低周波電磁波と高周波電磁波の両方が受信される場合には、被検出移動体は遮蔽物の陰に隠れておらず、見通し内の場所に存在すると判断することができるため、被検出側移動体が、視覚で確認できる位置にいるのか、それとも遮蔽物に隠れていて、視覚では確認できない位置にいるのかを判別して警報を発生することができる。
特開平２−２１６６００号公報特許第３８４４１７２号明細書 On the other hand, when both low-frequency electromagnetic waves and high-frequency electromagnetic waves are received, it can be determined that the detected moving body is not hidden behind the shielding object and is present in a line of sight. An alarm can be generated by determining whether the moving body is in a position that can be visually confirmed or in a position that is hidden by a shield and cannot be visually confirmed.
JP-A-2-216600 Japanese Patent No. 3844172

しかしながら、上記従来技術においては、被検出移動体を歩行者と考えた場合、歩行者が保持する移動通信端末は電池で駆動させる必要があり、低周波電磁波と高周波電磁波の両方を常に送信するとなると、電池の消費が実用上の大きな問題となる。また、周波数の異なる発信機を複数搭載するとなると、移動通信端末のコストも増大する。 However, in the above-described prior art, when the detected moving body is considered as a pedestrian, the mobile communication terminal held by the pedestrian needs to be driven by a battery, and always transmits both low-frequency electromagnetic waves and high-frequency electromagnetic waves. Battery consumption is a major problem in practical use. In addition, when a plurality of transmitters having different frequencies are installed, the cost of the mobile communication terminal also increases.

さらに、上記従来の技術では、高周波電磁波として赤外線を用いる例が示されているが、赤外線などの光を用いると、移動通信端末をかばんの中に入れたり、人体の反対側に保持したりしただけで、警戒対象が目視可能な場所に存在しても、赤外線は検出側移動体に到達しないため、正常に動作しない。 Furthermore, in the above conventional technique, an example using infrared rays as high-frequency electromagnetic waves has been shown. However, when light such as infrared rays is used, the mobile communication terminal is put in a bag or held on the opposite side of the human body. However, even if the alert target exists in a place where it can be visually observed, the infrared rays do not reach the detection-side moving body and thus do not operate normally.

一方、高周波電磁波として、マイクロ波程度の電波を用いると、高周波電磁波であっても多少は遮蔽物を回折するので、あまり回折の程度が厳しくないような状況では、高周波電波も受信できてしまうため、見通し内と見通し外の判断が難しくなってしまうという問題があった。 On the other hand, if microwaves are used as the high-frequency electromagnetic waves, the shielding object is diffracted to some extent even if they are high-frequency electromagnetic waves, so that they can be received in situations where the degree of diffraction is not so severe. There was a problem that it would be difficult to judge whether or not the prospect was out of sight.

本発明は、前記従来の問題を解決し、安全運転をより効果的に支援することのできる警戒対象検出装置、移動通信端末、安全運転支援システムおよび方法を提供することを目的としている。 An object of the present invention is to provide a warning object detection device, a mobile communication terminal, a safe driving support system, and a method that can solve the conventional problems and can support safe driving more effectively.

また、本発明は、歩行者などの警戒対象が自車両の運転者から視覚で確認できる位置にいるのか、それとも遮蔽物に隠れていて視認できない位置にいるのかを区別して、運転者に対して報知することができるとともに、警戒対象に保持される移動通信端末を低消費電力かつ簡単な構成で実現可能な警戒対象検出装置、移動通信端末、安全運転支援システムおよび方法を提供することを目的としている。 In addition, the present invention distinguishes whether a warning target such as a pedestrian is in a position where it can be visually confirmed from the driver of the own vehicle, or whether it is in a position where it is hidden by a shield and cannot be visually recognized. An object of the present invention is to provide a warning target detection device, a mobile communication terminal, a safe driving support system, and a method capable of notifying and capable of realizing a mobile communication terminal held in a warning target with low power consumption and a simple configuration. Yes.

本発明に係る警戒対象検出装置は、遮蔽物を容易に回折する低周波電波を送信する低周波電波送信部と、遮蔽物を容易に回折しない高周波電波を受信する高周波電波受信部と、を備える移動通信端末との無線通信により、当該移動通信端末の存在を検出する警戒対象検出装置であって、前記移動通信端末から送信された低周波電波を受信する低周波電波受信手段と、前記低周波電波受信部が受信した低周波電波の受信レベルを検出する受信レベル検出部と、前記受信レベル検出部が検出した低周波電波の受信レベルに応じて、前記移動通信端末との間の伝搬路に回折がなければ前記移動通信端末に到達し、回折があれば到達しないよう高周波電波のＡＣＫ要求信号の送信レベルを調整する送信レベル調整部と、前記送信レベル調整部で調整した送信レベルで前記ＡＣＫ要求信号を送信する高周波電波送信部と、前記ＡＣＫ要求信号に応じて前記移動通信端末から送信されたＡＣＫ信号を前記低周波電波受信部が受信したか否かに応じて、異なる報知を行う警報発生部と、を備える。 A warning target detection apparatus according to the present invention includes a low-frequency radio wave transmission unit that transmits a low-frequency radio wave that easily diffracts a shield, and a high-frequency radio wave reception unit that receives a high-frequency radio wave that does not easily diffract the shield. A warning target detection device for detecting the presence of the mobile communication terminal by wireless communication with the mobile communication terminal, the low frequency radio wave receiving means for receiving the low frequency radio wave transmitted from the mobile communication terminal, and the low frequency A reception level detection unit that detects a reception level of a low frequency radio wave received by the radio wave reception unit, and a propagation path between the mobile communication terminal according to the reception level of the low frequency radio wave detected by the reception level detection unit If there is no diffraction, it reaches the mobile communication terminal, and if there is diffraction, the transmission level adjustment unit adjusts the transmission level of the ACK request signal of the high frequency radio wave and adjusts the transmission level adjustment unit. Depending on whether the low frequency radio wave reception unit has received an ACK signal transmitted from the mobile communication terminal in response to the ACK request signal, a high frequency radio wave transmission unit that transmits the ACK request signal at a transmission level, An alarm generation unit for performing different notifications.

本発明によれば、移動通信端末の位置によって、高周波電波送信手段から所定の送信レベルで送信したＡＣＫ要求信号が移動通信端末に受信されるか否かが異なるため、当該移動通信端末からのＡＣＫ信号の有無によって、当該警戒対象が見通し内にいるのか見通し外にいるのかを判別することができる。このため、移動通信端末に高周波電波送信手段を搭載することなく、低消費電力かつ簡単な構成としながら、当該警戒対象の存在位置に応じて、適切な警告内容で警告することができる。 According to the present invention, whether or not an ACK request signal transmitted at a predetermined transmission level from the high-frequency radio wave transmission means is received by the mobile communication terminal depends on the position of the mobile communication terminal. Based on the presence or absence of a signal, it is possible to determine whether the subject of warning is in line of sight or out of line of sight. For this reason, it is possible to warn with an appropriate warning content according to the location of the alert target, while having a low power consumption and a simple configuration without mounting a high frequency radio wave transmission means in the mobile communication terminal.

（実施の形態１）
以下、本発明の実施の形態について、図面を参照しながら説明する。ここで説明する実施の形態１では、本発明を安全運転支援システムに適用した例を示す。 (Embodiment 1)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. Embodiment 1 described here shows an example in which the present invention is applied to a safe driving support system.

図１は、実施の形態１に係る安全運転支援システムの全体構成図である。図２は、本発明の実施の形態１に係る安全運転支援システムの簡略ブロック図である。図３は、本実施の形態１に係る安全運転支援システムの動作を説明するための図である。図４は、本実施の形態１に係る安全運転支援システムの動作を説明するフローチャートである。 1 is an overall configuration diagram of a safe driving support system according to Embodiment 1. FIG. FIG. 2 is a simplified block diagram of the safe driving support system according to Embodiment 1 of the present invention. FIG. 3 is a diagram for explaining the operation of the safe driving support system according to the first embodiment. FIG. 4 is a flowchart for explaining the operation of the safe driving support system according to the first embodiment.

実施の形態１で説明する安全運転支援システム１においては、一定距離範囲に届く強度で、遮蔽物を容易に回折する低周波電波を周期的に送信する発信機を歩行者が携帯し、警戒対象検出装置に相当する車載器が車両に搭載されている。 In the safe driving support system 1 described in the first embodiment, a pedestrian carries a transmitter that periodically transmits a low-frequency radio wave that easily diffracts a shielding object with an intensity that reaches a certain distance range. A vehicle-mounted device corresponding to the detection device is mounted on the vehicle.

図１に示すように、安全運転支援システム１は、歩行者Pa、Pb等がそれぞれ携帯している移動通信端末２a、２b等が一定距離範囲内に届く強度で定期的に発信している低周波電波を、車両Ｖに搭載されている警戒対象検出装置３が検出し、一定距離範囲内に歩行者が存在しているという情報を、歩行者の存在位置に応じて適切に、車両Ｖの運転者に提供するシステムである。 As shown in FIG. 1, the safe driving support system 1 is regularly transmitted with a strength that mobile communication terminals 2a, 2b, etc. carried by pedestrians Pa, Pb, etc. reach within a certain distance range. The alarm target detection device 3 mounted on the vehicle V detects the high frequency radio wave, and the information that the pedestrian is present within a certain distance range is appropriately displayed according to the location of the pedestrian. It is a system provided to the driver.

なお、安全運転支援システム１は、自転車などに発信機２a、２ｂと同様の移動通信端末が設置されていれば、歩行者以外の警戒対象、すなわち自転車なども検出可能である。また、小学生のランドセルや、年配者の杖など、交通弱者が一般的に保持しているものに移動通信端末２a、２ｂと同様の発信機を保持させておいてもよい。 Note that the safe driving support system 1 can detect a warning object other than a pedestrian, that is, a bicycle, if a mobile communication terminal similar to the transmitters 2a and 2b is installed on the bicycle. Moreover, you may hold | maintain the transmitter similar to the mobile communication terminals 2a and 2b to what a traffic weak person generally hold | maintains, such as a school bag of an elementary school student and a cane of an elderly person.

図２に示すように、移動通信端末２は、少なくとも、低周波電波送信手段４と、低周波電波用アンテナ５と、高周波電波用アンテナ６と、高周波電波受信手段７と、CPU８から構成される移動通信端末であり、日常的に歩行者に携帯される。 As shown in FIG. 2, the mobile communication terminal 2 includes at least a low frequency radio wave transmission means 4, a low frequency radio wave antenna 5, a high frequency radio wave antenna 6, a high frequency radio wave reception means 7, and a CPU 8. It is a mobile communication terminal and is carried by pedestrians on a daily basis.

一方、警戒対象検出装置３は、少なくとも、低周波電波用アンテナ９と、低周波電波受信手段１０と、受信レベル検出手段１１と、CPU１２と、送信レベル調整手段１３と、高周波電波送信手段１４と高周波電波用アンテナ１５と、警報発生手段１６から構成され、車両に搭載される。 On the other hand, the alarm target detection device 3 includes at least a low frequency radio wave antenna 9, a low frequency radio wave reception means 10, a reception level detection means 11, a CPU 12, a transmission level adjustment means 13, and a high frequency radio wave transmission means 14. It is composed of a high-frequency radio wave antenna 15 and an alarm generating means 16 and is mounted on a vehicle.

以下図１から図３、及び図４のフローチャートを用いて、具体的にどのように安全運転支援システム１が動作するかを説明する。図１において、歩行者Paは、車両Ｖとの間に遮蔽物が無く、車両Ｖから見通し内の位置に存在する。一方、歩行者Pbは、車両Ｖとの間に遮蔽物が存在し、車両Ｖからは見通し外の位置に存在する。また、車両Ｖとの間の距離は、歩行者Pa、Pb共に等距離である。 Hereinafter, how the safe driving support system 1 operates will be described in detail with reference to the flowcharts of FIGS. 1 to 3 and FIG. 4. In FIG. 1, the pedestrian Pa has no obstacle between the vehicle V and is present at a position within the line of sight from the vehicle V. On the other hand, the pedestrian Pb has a shielding object between the vehicle V and the vehicle V at a position outside the line of sight. The distance from the vehicle V is the same distance for both the pedestrians Pa and Pb.

移動通信端末２aと２bは、それぞれ低周波電波送信手段４を用いて、低周波電波用アンテナ５から、遮蔽物を容易に回折する低周波電波を定期的（例えば1秒周期）に全方向に送信する（図４：S21）。この低周波電波には、発信する移動通信端末のＩＤコードが付加されている。ここでは、低周波電波として４３０MHz帯の特定小電力無線の電波を送信する例を説明する。送信される低周波電波は、一定範囲内まで到達するように、全ての発信機で同じ出力に調整されている。 Each of the mobile communication terminals 2a and 2b uses low frequency radio wave transmission means 4 to periodically radiate low frequency radio waves that easily diffract the shield from the low frequency radio wave antenna 5 in all directions (for example, every 1 second). Transmit (FIG. 4: S21). An ID code of the mobile communication terminal to be transmitted is added to the low frequency radio wave. Here, an example of transmitting a specific low power radio wave of 430 MHz band as a low frequency radio wave will be described. The low frequency radio wave to be transmitted is adjusted to the same output by all the transmitters so as to reach a certain range.

また、各移動通信端末2は、無線ＬＡＮなどのマルチアクセス方式として一般的に知られているＣＳＭＡ／ＣＡ方式を搭載していて、複数の移動通信端末が同時に電波を発信することは無い。なお、マルチアクセスの方式については、代表例としてＣＳＭＡ／ＣＡ方式を示したが、なんら方式を限定するものではない。 Each mobile communication terminal 2 is equipped with a CSMA / CA system generally known as a multi-access system such as a wireless LAN, and a plurality of mobile communication terminals do not transmit radio waves simultaneously. As a multi-access scheme, the CSMA / CA scheme is shown as a representative example, but the scheme is not limited at all.

一方、車両Ｖに搭載されている警戒対象検出装置３は、各移動通信端末2から送信される低周波電波の受信を待つ（S31）。各移動通信端末２から送信される低周波電波は、空間を伝搬する間に減衰し、警戒対象検出装置３の低周波用アンテナ９と低周波電波受信手段１０により受信される（S32：Ｙｅｓ）。そして、受信レベル検出手段１１により、受信レベルが検出される（S33）。
このとき、移動通信端末２が送信する低周波電波の送信レベルは、全てのハードウェアで統一されているため、低周波電波を受信した警戒対象検出装置３は、移動通信端末２のID別に、各移動通信端末２から送信された低周波電波が、どれだけ減衰して到達したか（伝搬路の減衰量）を算出することができる（S33）。 On the other hand, the alert target detection device 3 mounted on the vehicle V waits for reception of a low-frequency radio wave transmitted from each mobile communication terminal 2 (S31). The low frequency radio wave transmitted from each mobile communication terminal 2 is attenuated while propagating through space, and is received by the low frequency antenna 9 and the low frequency radio wave receiving means 10 of the alert target detection device 3 (S32: Yes). . Then, the reception level is detected by the reception level detection means 11 (S33).
At this time, since the transmission level of the low-frequency radio wave transmitted by the mobile communication terminal 2 is unified by all hardware, the alert target detection device 3 that has received the low-frequency radio wave is classified according to the ID of the mobile communication terminal 2. It is possible to calculate how much the low-frequency radio wave transmitted from each mobile communication terminal 2 has been attenuated (the propagation path attenuation amount) (S33).

ここで、図１の例では、移動通信端末２aは見通し内の位置（すなわち、車両Ｖとの間に遮蔽物が存在しない位置）にいるため、移動通信端末２aから送信された低周波電波は、距離に依存する空間伝搬による減衰のみを受け、警戒対象検出装置３に到達する（図３（ア）のレベルダイヤグラムを参照）。 Here, in the example of FIG. 1, since the mobile communication terminal 2a is in a line-of-sight position (that is, a position where there is no shielding object with the vehicle V), the low-frequency radio wave transmitted from the mobile communication terminal 2a is Only the attenuation due to the spatial propagation depending on the distance is received, and the warning target detection device 3 is reached (see the level diagram in FIG. 3A).

一方、見通し外の位置（すなわち、車両Ｖとの間に遮蔽物が存在する位置）にいる移動通信端末２ｂから送信された低周波電波は、移動通信端末2aと同じく距離に依存する空間伝搬による減衰を受けるだけでなく、さらに遮蔽物を回折することによる回折損を受けて、警戒対象検出装置３に到達する（図３（イ）のレベルダイヤグラムを参照）。 On the other hand, the low-frequency radio wave transmitted from the mobile communication terminal 2b located at an out-of-sight position (that is, a position where an obstacle exists between the vehicle V) is caused by spatial propagation depending on the distance as in the mobile communication terminal 2a. In addition to being attenuated, it is further subjected to diffraction loss due to diffraction of the shielding object, and reaches the alarm target detection device 3 (see the level diagram in FIG. 3A).

次に、警戒対象検出装置３は、求めた低周波電波の減衰量に応じて、それぞれの移動通信端末に対する高周波電波（例：５．８ＧＨｚ）の送信レベルを決定する。そして、それぞれの移動通信端末２に対して、決定した送信レベルの高周波電波でACKを要求する信号（以降、ACK要求信号と記載）を送信する。このときの送信レベルの決定方法を説明する。 Next, the alert target detection device 3 determines the transmission level of the high-frequency radio wave (for example, 5.8 GHz) for each mobile communication terminal according to the obtained attenuation amount of the low-frequency radio wave. Then, a signal (hereinafter referred to as an ACK request signal) for requesting ACK is transmitted to each mobile communication terminal 2 using high-frequency radio waves of the determined transmission level. A method for determining the transmission level at this time will be described.

警戒対象検出装置３のＣＰＵ１２は、移動通信端末２が見通し内の位置に存在するという前提に立って、低周波電波の減衰量から移動通信端末２と警戒対象検出装置３との間の距離を求める（S34）。ここでは求めた距離を距離Dとして説明する。 The CPU 12 of the alert target detection device 3 determines the distance between the mobile communication terminal 2 and the alert target detection device 3 from the attenuation amount of the low frequency radio wave on the assumption that the mobile communication terminal 2 exists at a position within the line of sight. Ask (S34). Here, the obtained distance will be described as distance D.

次に、警戒対象検出装置３のＣＰＵ１２は、移動通信端末２の高周波電波受信手段７の受信限界レベル（もしくは、全ての移動通信端末で予め設定されている受信レベルの閾値）に、上記で求めた距離Dを高周波電波が伝搬する際に予想される損失を上乗せして、高周波電波の送信レベルを算出する（S35）。すなわち、警戒対象検出装置３のＣＰＵ１２は、警戒対象検出装置３から送信された高周波電波が、距離Ｄにかろうじて届く送信レベルをＡＣＫ要求信号の送信レベルとする。そして、警戒対象検出装置３は、送信レベル調整手段１３で送信レベルを調整し、高周波電波送信手段１４と高周波用アンテナ１５から、ACK要求信号を送信する（S36）。 Next, the CPU 12 of the alert target detection device 3 obtains the reception limit level of the high frequency radio wave reception means 7 of the mobile communication terminal 2 (or the reception level threshold set in advance for all mobile communication terminals) as described above. The transmission level of the high-frequency radio wave is calculated by adding a loss expected when the high-frequency radio wave propagates over the distance D (S35). That is, the CPU 12 of the alert target detection device 3 sets the transmission level at which the high-frequency radio wave transmitted from the alert target detection device 3 barely reaches the distance D as the transmission level of the ACK request signal. Then, the alert target detecting device 3 adjusts the transmission level by the transmission level adjusting means 13, and transmits the ACK request signal from the high frequency radio wave transmitting means 14 and the high frequency antenna 15 (S36).

なお、送信レベル決定は、低周波電波を受信するたびにその都度計算しなくてもよい。例えば、低周波電波の受信レベルと、送信すべき高周波電波の送信レベルとを対応づけるテーブルを予め用意しておき、このテーブルを参照して、送信レベルを決定してもよい。 The transmission level determination need not be calculated each time a low frequency radio wave is received. For example, a table that associates the reception level of low-frequency radio waves with the transmission level of high-frequency radio waves to be transmitted may be prepared in advance, and the transmission level may be determined with reference to this table.

移動通信端末２aに対するACK要求信号は、移動通信端末2aが見通し内の位置に存在するため、移動通信端末２の受信限界レベルよりも強いレベルで移動通信端末2aに到達し、移動通信端末2aの高周波電波用アンテナ６と高周波電波受信手段７により受信される（図３（ウ）のレベルダイヤグラムを参照）。 The ACK request signal for the mobile communication terminal 2a reaches the mobile communication terminal 2a at a level stronger than the reception limit level of the mobile communication terminal 2 because the mobile communication terminal 2a exists in the line-of-sight position. The signal is received by the high-frequency radio wave antenna 6 and the high-frequency radio wave receiving means 7 (see the level diagram in FIG. 3C).

このACK要求信号を受信した移動通信端末２aは（S22：YES）、容易に回折をする低周波電波を送信する低周波電波送信手段４と低周波用アンテナ５から、警戒対象検出装置３に対して、ACK信号を送信する（S23）。 The mobile communication terminal 2a that has received this ACK request signal (S22: YES) sends the low-frequency radio wave transmitting means 4 and the low-frequency antenna 5 that easily diffracts the low-frequency radio wave to the alert target detection device 3. ACK signal is transmitted (S23).

警戒対象検出装置３は、移動通信端末２aから送信された低周波電波のACK信号を一定時間以内（例として100ms以内）に受信した場合（S37：YES）には、このIDの移動通信端末2aを保持した歩行者Paが、警戒対象検出装置３から見通し内の位置にいることを判断する（S38）。この場合、警戒対象検出装置３は、警報発生手段１６から、ブザーを間欠音で鳴らし、見通し内に歩行者２aが存在することを、車両Vの運転者に知らせる。 When the alert target detection device 3 receives the ACK signal of the low frequency radio wave transmitted from the mobile communication terminal 2a within a certain time (for example, within 100 ms) (S37: YES), the mobile communication terminal 2a with this ID It is determined that the pedestrian Pa holding the position is within the line of sight from the alert target detection device 3 (S38). In this case, the warning target detection device 3 sounds the buzzer with an intermittent sound from the warning generation means 16 to notify the driver of the vehicle V that the pedestrian 2a exists within the line of sight.

一方、同じ手順であっても、警戒対象検出装置３から移動通信端末２bに対して送信されるACK要求信号は、遮蔽物の存在により回折損が発生する。移動通信端末２bに対するACK要求信号の送信レベルは、見通し内であれば、移動通信端末２ｂでかろうじて受信可能となるように調整されているが、実際には遮蔽物が存在するために、容易に回折をしない高周波電波は大きく減衰する。 On the other hand, even in the same procedure, the ACK request signal transmitted from the alert target detection device 3 to the mobile communication terminal 2b causes diffraction loss due to the presence of the shielding object. The transmission level of the ACK request signal for the mobile communication terminal 2b is adjusted so that the mobile communication terminal 2b can barely receive the signal within the line of sight. High-frequency radio waves that are not diffracted are greatly attenuated.

この結果、警戒対象検出装置３から移動通信端末２bに対して送信されたACK要求信号のレベルは、移動通信端末２の受信限界レベルを下回るため、移動体通信端末２ｂでは受信されない（図３（エ）のレベルダイヤグラムを参照）。 As a result, since the level of the ACK request signal transmitted from the alert target detection device 3 to the mobile communication terminal 2b is lower than the reception limit level of the mobile communication terminal 2, it is not received by the mobile communication terminal 2b (FIG. 3 ( (See the level diagram in d)).

つまり、警戒対象検出装置３は、移動通信端末２bに対するACK要求信号を送信してから一定時間以内に移動通信端末２bからのACK信号を受信しなければ（S37のNO）、このIDの移動通信端末2ｂを保持した歩行者Pｂが、警戒対象検出装置３から見通し外の位置（死角）にいることを判断できる（S39）。この場合、警戒対象検出手段３は、警報発生手段１６から、ブザーを連続音で鳴らし、見通し外に歩行者２ｂが存在することを、車両Vの運転者に知らせる。 That is, if the alert target detection device 3 does not receive an ACK signal from the mobile communication terminal 2b within a predetermined time after transmitting the ACK request signal to the mobile communication terminal 2b (NO in S37), the mobile communication of this ID It can be determined that the pedestrian Pb holding the terminal 2b is at a position outside the line of sight (dead angle) from the alert target detection device 3 (S39). In this case, the warning target detection unit 3 sounds a buzzer with a continuous sound from the warning generation unit 16 to notify the driver of the vehicle V that the pedestrian 2b exists outside the line of sight.

以上のようにすることで、車両Vの運転者は、警戒対象検出装置３が発生するブザーによって周囲に歩行者がいることを知ることができ、加速などはせず制動操作への準備行動をとることができる。 By doing as described above, the driver of the vehicle V can know that there are pedestrians around by the buzzer generated by the alert target detection device 3, and does not accelerate and prepares for the braking operation. Can take.

さらに、そのブザーが連続音であった場合には、運転者は見通し外に歩行者が存在することを認識できるので、仮に見通し内に歩行者が存在しても、見通し外の歩行者に対する警戒を怠ることなく、急な飛び出しに注意しながら、運転を行うことができるようになる。 Furthermore, if the buzzer is a continuous sound, the driver can recognize that there are pedestrians outside the line of sight. Without neglecting, you will be able to drive while paying attention to sudden jumping out.

なお、以上の説明では、警戒対象が見通し内に存在するか見通し外に存在するかに応じて、警戒対象検出装置３が警報発生手段１６から発生するブザーの音を変える例を示したが、警報発生手段１６が発生する警報は、ブザー音に限られない。例えば、警戒対象が見通し内に存在するか見通し外に存在するかに応じて、音声出力の内容や光の点滅パターン等を変更してもよい。 In the above description, the example in which the alarm target detection device 3 changes the buzzer sound generated from the alarm generation unit 16 depending on whether the alarm target is in the line of sight or out of line of sight is shown. The alarm generated by the alarm generation means 16 is not limited to a buzzer sound. For example, the content of the audio output, the light blinking pattern, or the like may be changed depending on whether the alert target is within the line of sight or outside the line of sight.

（実施の形態２）
次に別な実施の形態を実施の形態２として説明する。以下、実施の形態２について、図面を参照しながら説明する。実施の形態２においても、本発明を安全運転支援システムに適用した例を示す。なお、以下の説明に使用する図１については、実施の形態１の説明に用いたものと同じであるので、説明は省略する。 (Embodiment 2)
Next, another embodiment will be described as a second embodiment. The second embodiment will be described below with reference to the drawings. Embodiment 2 also shows an example in which the present invention is applied to a safe driving support system. Note that FIG. 1 used in the following description is the same as that used in the description of the first embodiment, and thus the description thereof is omitted.

実施の形態２で説明する安全運転支援システム１においては、車両に搭載された警戒対象検出装置１０３が、一定距離範囲に届く強度で、遮蔽物を容易に回折する低周波電波を周期的に送信するという点が実施の形態１と異なる。 In the safe driving support system 1 described in the second embodiment, the warning target detection device 103 mounted on the vehicle periodically transmits low-frequency radio waves that easily diffract the shielding object with an intensity reaching a certain distance range. This is different from the first embodiment.

図５は、本発明の実施の形態２に係る安全運転支援システムの簡略ブロック図である。実施の形態２で説明する安全運転支援システム１においても、実施の形態１と同様に、一定距離範囲に届く強度で、遮蔽物を容易に回折する低周波電波を断続的に送信する発信機を歩行者が携帯し、警戒対象検出装置に相当する車載器が車両に搭載されている。 FIG. 5 is a simplified block diagram of a safe driving support system according to Embodiment 2 of the present invention. In the safe driving support system 1 described in the second embodiment, similarly to the first embodiment, a transmitter that intermittently transmits a low-frequency radio wave that easily diffracts a shield with an intensity reaching a certain distance range. An in-vehicle device that is carried by a pedestrian and corresponds to a warning object detection device is mounted on the vehicle.

図５に示すように、移動通信端末１０２は、少なくとも、低周波電波送信手段１０４と、低周波電波用アンテナ１０５と、高周波電波用アンテナ１０６と、高周波電波受信手段１０７と、CPU１０８と、低周波電波受信手段１２０と、受信レベル検出手段１２１とから構成される移動通信端末であり、日常的に歩行者に携帯される。 As shown in FIG. 5, the mobile communication terminal 102 includes at least a low frequency radio wave transmission means 104, a low frequency radio wave antenna 105, a high frequency radio wave antenna 106, a high frequency radio wave reception means 107, a CPU 108, It is a mobile communication terminal comprising radio wave receiving means 120 and reception level detecting means 121, and is carried by pedestrians on a daily basis.

一方、警戒対象検出装置１０３は、少なくとも、低周波電波用アンテナ１０９と、低周波電波送信手段１００と、低周波電波受信手段１１０と、CPU１１２と、送信レベル調整手段１１３と、高周波電波送信手段１１４と高周波電波用アンテナ１１５と、警報発生手段１１６から構成され、車両に搭載される。 On the other hand, the alert target detection device 103 includes at least a low-frequency radio wave antenna 109, a low-frequency radio wave transmission unit 100, a low-frequency radio wave reception unit 110, a CPU 112, a transmission level adjustment unit 113, and a high-frequency radio wave transmission unit 114. And the high-frequency radio wave antenna 115 and the alarm generation means 116, which are mounted on the vehicle.

以下、図６のフローチャートを用いて、本実施の形態２における安全運転支援システム１がどのように動作するかを具体的に説明する。図１は、実施の形態１と同じように、歩行者Paは、車両Ｖとの間に遮蔽物が無く、車両Ｖから見通し内の位置に存在する。一方、歩行者Pbは、車両Ｖとの間に遮蔽物が存在し、車両Ｖからは見通し外の位置に存在する。また、車両Ｖとの間の距離は、歩行者Pa、Pb共に等距離である。 Hereinafter, how the safe driving support system 1 according to the second embodiment operates will be specifically described with reference to the flowchart of FIG. 6. In FIG. 1, as in the first embodiment, the pedestrian Pa does not have an obstacle between the vehicle V and exists in a line of sight from the vehicle V. On the other hand, the pedestrian Pb has a shielding object between the vehicle V and the vehicle V at a position outside the line of sight. The distance from the vehicle V is the same distance for both the pedestrians Pa and Pb.

警戒対象検出装置１０３は、低周波電波送信手段１００を用いて、低周波電波用アンテナ１０９から、遮蔽物を容易に回折する低周波電波を定期的（例えば1秒周期）に全方向に送信する。
また、これと同時に警戒対象検出装置１０３は、高周波電波送信手段１１４を用いて高周波電波用アンテナ１１５から遮蔽物を容易に回折しない高周波電波を送信する（S121）。このとき、警戒対象検出装置１０３は実施の形態１と同様、マルチアクセス方式として、ＣＳＭＡ／ＣＡ方式を搭載しているため、複数の警戒対象検出装置が同時に低周波電波及び高周波電波を発信することは無い。この低周波電波および高周波電波には、発信する警戒対象検出装置１０３のＩＤコードが付加されている。 The alert target detection device 103 uses the low-frequency radio wave transmission means 100 to periodically transmit a low-frequency radio wave that easily diffracts the shielding object from all of the low-frequency radio wave antennas 109 (for example, every 1 second) in all directions. .
At the same time, the alert target detection device 103 transmits a high-frequency radio wave that does not easily diffract the shield from the high-frequency radio wave antenna 115 using the high-frequency radio wave transmission means 114 (S121). At this time, since the alert target detection device 103 is equipped with the CSMA / CA method as the multi-access method as in the first embodiment, a plurality of the alert target detection devices simultaneously transmit the low frequency radio wave and the high frequency radio wave. There is no. The ID code of the alert target detecting device 103 to be transmitted is added to the low frequency radio wave and the high frequency radio wave.

一方、移動通信端末１０２は、警戒対象検出装置１０３から送信される低周波電波及び高周波電波の受信を待つ（S131）。警戒対象検出装置１０３から送信される低周波電波及び高周波電波は、空間を伝搬する間に減衰し、低周波電波は、移動通信端末１０２の低周波用アンテナ１０５と低周波電波受信手段１２０により受信される（S132：Ｙｅｓ）。そして、低周波電波受信レベル検出手段１２１により、受信レベルが検出される（S１３３）。
このとき、警戒対象検出装置１０３が送信する低周波電波の送信レベルは、全てのハードウェアで統一されているため、低周波電波を受信した移動通信端末１０２は、警戒対象検出装置１０３のID別に、警戒対象検出装置１０３から送信された低周波電波と高周波電波が、どれだけ減衰して到達したか（伝搬路の減衰量）を算出することができる（Ｓ１３３）。 On the other hand, the mobile communication terminal 102 waits for reception of a low-frequency radio wave and a high-frequency radio wave transmitted from the alert target detection device 103 (S131). The low-frequency radio wave and the high-frequency radio wave transmitted from the alert target detection device 103 are attenuated while propagating in space, and the low-frequency radio wave is received by the low-frequency antenna 105 and the low-frequency radio wave receiving means 120 of the mobile communication terminal 102. (S132: Yes). Then, the reception level is detected by the low frequency radio wave reception level detecting means 121 (S133).
At this time, since the transmission level of the low frequency radio wave transmitted by the alert target detection device 103 is unified by all hardware, the mobile communication terminal 102 that has received the low frequency radio wave is classified by the ID of the alert target detection device 103. It is possible to calculate how much the low-frequency radio wave and the high-frequency radio wave transmitted from the alert target detection device 103 are attenuated (arrival amount of the propagation path) (S133).

一方、同じく高周波電波は、移動通信端末１０２の高周波用アンテナ１０６と高周波電波受信手段１０７により受信され、高周波電波受信レベル検出手段１０９により受信レベルが検出される。そして、減衰量を求めることができる（Ｓ１３４）。 On the other hand, the high frequency radio wave is similarly received by the high frequency antenna 106 and the high frequency radio wave reception means 107 of the mobile communication terminal 102, and the reception level is detected by the high frequency radio wave reception level detection means 109. Then, the attenuation can be obtained (S134).

図１において、車両Ｖと歩行者Paは見通し内の関係である。従って、歩行者Paが保持する移動通信端末１０２aにおいて、低周波電波と高周波電波の減衰量の差は、距離に依存する。よって、求めた低周波電波の減衰量と高周波電波の減衰量は、予め見通し内で測定して、テーブルとして移動通信端末１０２に記録されている比率を保つ。 In FIG. 1, the vehicle V and the pedestrian Pa are in a line-of-sight relationship. Therefore, in the mobile communication terminal 102a held by the pedestrian Pa, the difference in attenuation between the low frequency radio wave and the high frequency radio wave depends on the distance. Therefore, the obtained attenuation amount of the low frequency radio wave and the attenuation amount of the high frequency radio wave are measured in advance within the line of sight, and the ratio recorded in the mobile communication terminal 102 as a table is maintained.

一方、車両Ｖと歩行者Paは、見通し外の関係である。従って、低周波電波は比較的容易に障害物を回折して携帯端末１０２bに到達するが、高周波電波は大きく減衰するため、非常にレベルが小さくなる（もしくは、到達しない）。 On the other hand, the vehicle V and the pedestrian Pa are in an out-of-sight relationship. Accordingly, the low-frequency radio wave diffracts the obstacle relatively easily and reaches the portable terminal 102b, but the high-frequency radio wave is greatly attenuated, so that the level becomes very small (or does not reach).

よって、予めテーブルに準備されている見通し内でのレベル比よりも大きくなる。移動通信端末１０２は、このテーブルのレベル比との比較をすることで、警戒対象検出装置１０３が見通し内であるか、見通し外であるかを判定することができる（Ｓ１３５）。
車両Ｖとの位置関係の判定を実施した移動通信端末１０２は、判定結果を低周波電波送信手段１０４と低周波電波用アンテナ１０５から送信する（Ｓ１３６）。 Therefore, it becomes larger than the level ratio within the line of sight prepared in advance in the table. The mobile communication terminal 102 can determine whether the alert target detection device 103 is in line of sight or out of line of sight by comparing with the level ratio in this table (S135).
The mobile communication terminal 102 that has determined the positional relationship with the vehicle V transmits the determination result from the low-frequency radio wave transmission means 104 and the low-frequency radio wave antenna 105 (S136).

警戒対象検出装置１０３は、前記判定結果を低周波電波用アンテナ１０９と低周波電波受信手段１１０で受信することによって（Ｓ１２２：Ｙｅｓ、Ｓ１２３）、各移動通信端末１０２との位置関係を知ることができる。 The alert target detection device 103 can know the positional relationship with each mobile communication terminal 102 by receiving the determination result with the low-frequency radio wave antenna 109 and the low-frequency radio wave receiving means 110 (S122: Yes, S123). it can.

このように、本実施形態の安全運転支援システムは、警戒対象が保持する移動通信端末１０２と無線通信を行い、車両の周囲に存在する警戒対象を検出する警戒対象検出装置１０３であって、前記警戒対象検出装置１０３は、遮蔽物を容易に回折する低周波電波を送信する低周波電波送信手段１００と、前記低周波電波を受信する手段１１０と、遮蔽物を容易に回折しない高周波電波を送信する高周波電波送信手段１１４を持ち、前記低周波電波送信手段１００から前記低周波電波を送信すると同時に前記高周波電波送信手段１１４から前記高周波電波を送信し、前記移動通信端末１０２は、前記低周波電波を受信する低周波電波受信手段１２０と、前記低周波電波受信手段１２０が受信した低周波電波の受信レベルを検出する低周波電波受信レベル検出手段１２１と、前記低周波電波を送信する低周波電波送信手段１０４と、前記高周波電波を受信する高周波電波受信手段１０７と、前記高周波電波受信手段１０７が受信した高周波電波の受信レベルを検出する高周波電波受信レベル検出手段１０９を持ち、前記低周波電波が前記低周波電波受信手段１２０により受信された場合に、前記低周波電波の受信レベルと前記高周波電波の受信レベルから伝搬路の状況を判定し、判定した結果を前記警戒対象検出装置１０３に前記低周波電波で送信することを特徴とする警戒対象検出装置１０３である。 As described above, the safe driving support system of the present embodiment is a warning target detection apparatus 103 that performs wireless communication with the mobile communication terminal 102 held by the warning target and detects a warning target that exists around the vehicle. The alarm target detection device 103 transmits a low-frequency radio wave transmission means 100 that transmits a low-frequency radio wave that easily diffracts a shield, a means 110 that receives the low-frequency radio wave, and a high-frequency radio wave that does not easily diffract the shield. High-frequency radio wave transmission means 114 for transmitting the low-frequency radio wave from the low-frequency radio wave transmission means 100, and simultaneously transmitting the high-frequency radio wave from the high-frequency radio wave transmission means 114. Low frequency radio wave receiving means 120 for receiving the low frequency radio wave receiving means 120 for detecting the reception level of the low frequency radio wave received by the low frequency radio wave receiving means 120. Level detection means 121, low frequency radio wave transmission means 104 for transmitting the low frequency radio wave, high frequency radio wave reception means 107 for receiving the high frequency radio wave, and reception level of the high frequency radio wave received by the high frequency radio wave reception means 107 are detected. When the low frequency radio wave is received by the low frequency radio wave receiving means 120, the state of the propagation path is determined from the reception level of the low frequency radio wave and the reception level of the high frequency radio wave. It is a warning object detection apparatus 103 characterized by determining and transmitting the determined result to the warning object detection apparatus 103 by the low frequency radio wave.

この構成により、警戒対象検出装置１０３は、遮蔽物を容易に回折する低周波電波を送信するため、移動通信端末１０２との間の遮蔽物の有無にかかわらず、低周波電波は移動通信端末１０２に到達する。 With this configuration, the alert target detection device 103 transmits a low-frequency radio wave that easily diffracts the shielding object. Therefore, the low-frequency radio wave is transmitted to the mobile communication terminal 102 regardless of the presence or absence of the shielding object with the mobile communication terminal 102. To reach.

これと同時に警戒対象検出装置１０３は、遮蔽物を容易に回折しない高周波電波を送信する。送信された高周波電波は、移動通信端末１０２との間の伝搬環境の状況に応じて大きく減衰する。移動通信端末１０２は、低周波電波の減衰量と、高周波電波の減衰量との比較を行うことで、遮蔽物の有無と遮蔽の度合いを判断することができる。この判定結果を低周波電波で警戒対象検出装置１０３に送信することにより、警戒対象検出装置１０３は、移動通信端末１０２との間に遮蔽物があるか無いかを認識することができる。 At the same time, the alert target detection apparatus 103 transmits high-frequency radio waves that do not easily diffract the shield. The transmitted high frequency radio wave is greatly attenuated according to the state of the propagation environment with the mobile communication terminal 102. The mobile communication terminal 102 can determine the presence / absence of the shielding object and the degree of shielding by comparing the attenuation amount of the low-frequency radio wave with the attenuation amount of the high-frequency radio wave. By transmitting this determination result to the alert target detection device 103 with low frequency radio waves, the alert target detection device 103 can recognize whether or not there is an obstacle between the mobile communication terminal 102 and the mobile communication terminal 102.

この結果、警戒対象検出装置１０３は、移動通信端末１０２が見通し内にいるのか、見通し外にいるのかを判定可能となり、警戒対象の存在位置に応じて、適切な警告内容を警告することができる。また、移動通信端末１０２側は低周波電波のみ送信するため、従来の、高周波電波を送信する技術よりも電池の消費が少なく、かつ簡単な構成で、装置を構成することができるために、安価に装置を作ることができる。さらに、従来の技術では判別することができなかった、遮蔽の度合いが厳しくない見通し外でも判別をすることができる。 As a result, the alert target detection device 103 can determine whether the mobile communication terminal 102 is in line of sight or out of line of sight, and can warn of appropriate warning content according to the location of the alert target. . In addition, since the mobile communication terminal 102 transmits only low-frequency radio waves, it consumes less battery than the conventional technology for transmitting high-frequency radio waves, and the apparatus can be configured with a simple configuration. Can make the equipment. Furthermore, it is possible to make a discrimination even when it is out of line of sight where the degree of shielding is not severe, which could not be discriminated with the conventional technology.

以上のようにすることで、本実施の形態２においても、警戒対象検出装置１０３を搭載した車両から、歩行者Ｐが見通し内なのか、見通し外なのかを判断して、車両Ｖの運転者に対して適切な警報を出すことが可能となる。 As described above, also in the second embodiment, it is determined whether the pedestrian P is in line of sight or out of line of sight from the vehicle equipped with the alert target detection device 103, and the driver of the vehicle V It is possible to issue an appropriate alarm.

本発明は、電波を用いて交通事故の警戒対象を検出した上で、当該の警戒対象が見通し内にいるのか見通し外にいるのかを判別することができるため、移動通信端末を低消費電力かつ簡単な構成としながら、当該の警戒対象の存在位置に応じて、適切な警告内容で警告することができる効果を有し、警戒対象検出装置および警戒対象検出装置を用いた警戒対象存在情報提供システム等として有用である。 In the present invention, it is possible to determine whether a warning target is in line of sight or out of line of sight after detecting the alarm target of a traffic accident using radio waves. While having a simple configuration, it has the effect of being able to warn with appropriate warning contents according to the location of the alert target, and the alert target detection device and the alert target presence information providing system using the alert target detection device Useful as such.

本発明の実施の形態１、２に係る安全運転支援システムの全体構成図Overall configuration diagram of a safe driving support system according to Embodiments 1 and 2 of the present invention 本発明の実施の形態１に係る安全運転支援システムのブロック図Block diagram of the safe driving support system according to Embodiment 1 of the present invention 本発明の実施の形態１における見通し内・見通し外の判定に係る説明図Explanatory drawing which concerns on determination of in-line / out-of-line in Embodiment 1 of the present invention 本発明の実施の形態１の動作を説明するフローチャートThe flowchart explaining operation | movement of Embodiment 1 of this invention. 本発明の実施の形態２に係る安全運転支援システムのブロック図Block diagram of a safe driving support system according to Embodiment 2 of the present invention 本発明の実施の形態２の動作を説明するフローチャートFlowchart explaining the operation of the second embodiment of the present invention

Explanation of symbols

１安全運転支援システム
２，２a，２b，１０２移動通信端末
３，１０３警戒対象検出装置
４，１００，１０４，１０９低周波電波送信手段
５，９，１０５低周波電波用アンテナ
６，１５，１０６，１１５高周波電波用アンテナ
７，１０７高周波電波受信手段
８，１２，１０８，１１２ CPU
１０，１１０，１２０低周波電波受信手段
１１受信レベル検出手段
１３送信レベル調整手段
１４，１１４高周波電波送信手段
１６，１１６警報発生手段
１０９高周波電波受信レベル検出手段
１２１低周波電波受信レベル検出手段
Pa，Pb 歩行者
Ｖ車両 DESCRIPTION OF SYMBOLS 1 Safe driving assistance system 2, 2a, 2b, 102 Mobile communication terminal 3,103 Warning object detection apparatus 4,100,104,109 Low frequency radio wave transmission means 5,9,105 Low frequency radio wave antenna 6,15,106, 115 High Frequency Radio Antenna 7, 107 High Frequency Radio Receiving Means 8, 12, 108, 112 CPU
10, 110, 120 Low frequency radio wave reception means 11 Reception level detection means 13 Transmission level adjustment means 14, 114 High frequency radio wave transmission means 16, 116 Alarm generation means 109 High frequency radio wave reception level detection means 121 Low frequency radio wave reception level detection means
Pa, Pb Pedestrian V Vehicle

Claims

By wireless communication with a mobile communication terminal including a low-frequency radio wave transmission unit that transmits a low-frequency radio wave that easily diffracts the shield, and a high-frequency radio wave reception unit that receives a high-frequency radio wave that does not easily diffract the shield, A warning target detection device that detects the presence of a mobile communication terminal,
A low-frequency radio wave receiver that receives low-frequency radio waves transmitted from the mobile communication terminal;
A reception level detection unit for detecting a reception level of the low frequency radio wave received by the low frequency radio wave reception unit;
According to the reception level of the low-frequency radio wave detected by the reception level detector, the high-frequency radio wave reaches the mobile communication terminal if there is no diffraction in the propagation path to the mobile communication terminal, and does not reach if there is diffraction A transmission level adjustment unit for adjusting the transmission level of the ACK request signal of
A high-frequency radio wave transmission unit that transmits the ACK request signal at a transmission level adjusted by the transmission level adjustment unit;
Depending on whether or not the low frequency radio wave reception unit has received an ACK signal transmitted from the mobile communication terminal in response to the ACK request signal, an alarm generation unit that performs different notifications, and
A warning object detection device comprising:

A warning object detection device according to claim 1,
The low frequency radio wave transmitted by the mobile communication terminal includes an ID code for identifying the mobile communication terminal to transmit,
The high-frequency radio wave transmission unit is a warning target detection device that transmits the ACK request signal to a mobile communication terminal identified by the ID code.

A warning object detection device according to claim 1,
The transmission level adjustment unit calculates the attenuation amount of the low-frequency radio wave in the corresponding propagation path from the detected reception level of the low-frequency radio wave, and when the mobile communication terminal exists in line of sight from the calculated attenuation amount of the low-frequency radio wave Calculate the line-of-sight distance when assumed, calculate the attenuation amount of the high-frequency radio wave corresponding to the line-of-sight distance, and add the attenuation amount of the high-frequency radio wave to the reception limit level of the mobile communication terminal A warning object detection device that calculates

A warning object detection device according to claim 1,
The said transmission level adjustment part is a warning object detection apparatus containing what determines the transmission level of a high frequency electric wave with reference to the table which matches the reception level of a low frequency electric wave, and the transmission level of the high frequency electric wave which should be transmitted.

A mobile communication terminal that transmits a warning signal to a warning target detection device,
The warning object detection device according to any one of claims 1 to 4, wherein the mobile communication terminal is adjusted so as not to reach if there is no diffraction in a propagation path between the warning object detection device and not to reach if there is diffraction. A high-frequency radio wave receiver that receives an ACK request signal that is transmitted,
When the ACK request signal can be received, a low frequency radio wave transmission unit that transmits an ACK signal corresponding to the ACK request signal with a low frequency radio wave to the alert target detection device;
A mobile communication terminal comprising:

The mobile communication terminal according to claim 5, wherein
A mobile communication terminal in which the low frequency radio wave includes an ID code for identifying a mobile communication terminal to transmit.

A safe driving support system comprising the alert target detection device according to any one of claims 1 to 4 and the mobile communication terminal according to any one of claims 5 to 6.

By wireless communication with a mobile communication terminal including a low-frequency radio wave transmission unit that transmits a low-frequency radio wave that easily diffracts the shield, and a high-frequency radio wave reception unit that receives a high-frequency radio wave that does not easily diffract the shield, A warning target detection method for detecting the presence of a mobile communication terminal,
A low-frequency radio wave receiving step for receiving a low-frequency radio wave transmitted from the mobile communication terminal;
A reception level detection step for detecting a reception level of the low frequency radio wave received in the low frequency radio wave reception step;
According to the reception level of the low-frequency radio wave detected in the reception level detection step, the high-frequency radio wave reaches the mobile communication terminal if there is no diffraction in the propagation path to the mobile communication terminal, and does not reach if there is diffraction. A transmission level adjustment step of adjusting the transmission level of the ACK request signal of
An ACK request signal transmission step of transmitting the ACK request signal at the transmission level adjusted in the transmission level adjustment step;
An ACK signal receiving step of receiving an ACK signal of a low frequency radio wave transmitted from the mobile communication terminal in response to the ACK request signal;
Depending on whether or not the ACK signal is received in the ACK signal reception step, an alarm generation step for performing different notifications;
A warning object detection method comprising: