JP2004106588A

JP2004106588A - Driving support system for vehicle

Info

Publication number: JP2004106588A
Application number: JP2002268734A
Authority: JP
Inventors: Hiroyuki Sekiguchi; 関口　弘幸
Original assignee: Fuji Heavy Industries Ltd
Current assignee: Subaru Corp
Priority date: 2002-09-13
Filing date: 2002-09-13
Publication date: 2004-04-08
Anticipated expiration: 2022-09-13
Also published as: JP4204830B2

Abstract

<P>PROBLEM TO BE SOLVED: To perform driving support which is natural and gives no uncomfortable feeling to a driver, being adaptable, especially to a road without large-scale infrastructure and excellent in general versatility, and extremely highly safe by preparing for deceleration under the condition where actual deceleration is not needed and decelerating without fail in a good response as needed. <P>SOLUTION: Mainly a stereocamera 3, a send/receive section 4, a distance measuring apparatus 5 and a forward-information-recognizing device 6 detect forward information, information of vehicle just ahead and a vehicle in front of the vehicle just ahead. In driving support control in the case the vehicle just ahead and the vehicle in front of the vehicle just ahead exist, a control device 7 controls to perform braking preparation by previous increase of brake oil pressure when the distance between the vehicle just ahead and the vehicle in front of the vehicle just ahead becomes short and the vehicle just ahead rapidly approaches the vehicle in front of the vehicle just ahead. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、ミリ波レーダ、赤外線レーザレーダ、ステレオカメラや単眼カメラ等の画像認識装置等の前方認識装置で車両前方の道路状況を認識し、自車速や先行車との車間距離を自動制御する車両用運転支援装置に関する。
【０００２】
【従来の技術】
近年、ミリ波レーダ、赤外線レーザレーダ、ステレオカメラや単眼カメラ等の画像認識装置等の前方認識装置で車両前方の道路状況を認識し、自車速や先行車との車間距離を自動制御する車両用運転支援装置が実用化されている。
【０００３】
このような車両用運転支援装置では、先行車との車間距離を設定距離範囲に維持しながら追随走行する制御を行う場合、その追随走行時の速度が先行車のさらに前を走行している先々行車の走行状態の影響を受けて不安定になる可能性がある。このため、例えば、特開２００１−１９９２５７号公報では、先行車との距離を測定し、また、自車両と先々行車の位置を示す車間距離データを走行支援システムの路側機から受信し、その受信データに基いて先々行車との間の距離を判定して、先行車との車間距離に基づいた加減速制御を行うことにより自車両を先行車に追随走行させると共に、その加減速制御を行う際に先々行車との車間距離を加味した制御を行う技術が開示されている。
【０００４】
【特許文献１】
特開２００１−１９９２５７号公報
【０００５】
【発明が解決しようとする課題】
しかしながら、上述の先行技術では、先々行車の捕捉が走行支援システムが整備されている、インフラストラクチュアが整った走行路でしか適用できず、汎用性が極めて低いという問題がある。また、自車両と先行車との距離と自車両と先々行車との距離に応じて加速制御や減速制御を行うようになっているため、チューニングによっては加速と減速とが不自然に発生し、実際に前方を視認して運転するドライバに対して却って違和感を与える可能性がある。
【０００６】
本発明は上記事情に鑑みてなされたもので、特に大規模なインフラストラクチュアのない道路でも容易に採用でき汎用性に優れ、実際に減速を行うまでもない状況下にあっては減速に備え、必要なときには確実にレスポンス良く減速して安全性が極めて高く、ドライバに対して自然で違和感のない運転支援が行える車両用運転支援装置を提供することを目的とする。
【０００７】
【課題を解決するための手段】
上記目的を達成するため請求項１記載の本発明による車両用運転支援装置は、自車両前方の環境を検出し認識する車載の前方情報認識手段と、上記前方情報認識手段からの前方情報に基づき先行車情報を検出する先行車情報検出手段と、上記前方情報認識手段からの上記前方情報と上記先行車情報に基づき上記先行車のさらに前方を走行する先々行車情報を検出する先々行車情報検出手段と、上記前方情報と上記先行車情報と上記先々行車情報に基づく走行制御を実行すると共に、上記先行車情報と上記先々行車情報に基づき少なくともブレーキ手段による制動準備を行わせる制御手段とを備えたことを特徴としている。
【０００８】
また、請求項２記載の本発明による車両用運転支援装置は、請求項１記載の車両用運転支援装置において、上記先々行車情報検出手段は、上記先行車情報検出手段で検出した先行車ではなく、且つ、該検出した先行車よりも遠方に存在し、且つ、自車両の走行領域に進入した自車両に最も近い位置に存在する前方立体物を上記先々行車として検出することを特徴としている。
【０００９】
更に、請求項３記載の本発明による車両用運転支援装置は、請求項１又は請求項２記載の車両用運転支援装置において、上記制御手段は、上記先行車と上記先々行車との車間距離が予め設定した距離より接近し、且つ、上記先行車の速度が上記先々行車の速度より予め設定した速度を超えて大きくなる場合に上記ブレーキ手段による制動準備を行わせることを特徴としている。
【００１０】
また、請求項４記載の本発明による車両用運転支援装置は、請求項１乃至請求項３の何れか一つに記載の車両用運転支援装置において、上記制御手段は、上記ブレーキ手段による制動準備を予めブレーキ油圧を高めておくことで行うことを特徴としている。
【００１１】
更に、請求項５記載の本発明による車両用運転支援装置は、請求項１乃至請求項４の何れか一つに記載の車両用運転支援装置において、上記制御手段は、少なくとも自車両と上記先行車との目標車間距離を求めて走行制御を行うものであって、上記制御手段は、上記先行車が存在する場合には第１の目標車間距離を求め、上記先々行車が存在する場合には第２の目標車間距離を求め、上記先行車のみが存在する場合には上記第１の目標車間距離を上記目標車間距離として設定し、上記先々行車が存在する場合には上記第１の目標車間距離と上記第２の目標車間距離とに応じて上記目標車間距離を設定することを特徴としている。
【００１２】
また、請求項６記載の本発明による車両用運転支援装置は、請求項１乃至請求項５の何れか一つに記載の車両用運転支援装置において、上記制御手段が上記ブレーキ手段による制動準備を行わせる状態であることを車内と車外の少なくともどちらかに報知又は通信する報知通信手段を備えたことを特徴としている。
【００１３】
すなわち、上記請求項１記載の車両用運転支援装置は、車載の前方情報認識手段で自車両前方の環境を検出し認識し、先行車情報検出手段で前方情報認識手段からの前方情報に基づき先行車情報を検出し、先々行車情報検出手段で前方情報認識手段からの前方情報と先行車情報に基づき先行車のさらに前方を走行する先々行車情報を検出する。そして、制御手段で前方情報と先行車情報と先々行車情報に基づく走行制御を実行すると共に、先行車情報と先々行車情報に基づき少なくともブレーキ手段による制動準備を行わせる。
【００１４】
このため、特に大規模なインフラストラクチュアのない道路でも容易に採用でき汎用性に優れ、実際に減速を行うまでもない状況下にあっては減速に備え、必要なときには確実にレスポンス良く減速して安全性が極めて高く、ドライバに対して自然で違和感のない運転支援が行える。特に、直ぐに制動するのではなく、制動準備を行うようにしているため、加速と減速とが不自然に生じることがなく、また、制動準備状態とすることで、制動の際のレスポンスの良いブレーキングが期待でき安全性を向上させることができる。
【００１５】
この際、先々行車情報検出手段は、具体的には請求項２記載のように、先行車情報検出手段で検出した先行車ではなく、且つ、該検出した先行車よりも遠方に存在し、且つ、自車両の走行領域に進入した自車両に最も近い位置に存在する前方立体物を先々行車として検出することにより、先々行車を確実に検出できる。
【００１６】
また、制御手段は、具体的には請求項３記載のように、先行車と先々行車との車間距離が予め設定した距離より接近し、且つ、先行車の速度が先々行車の速度より予め設定した速度を超えて大きくなる場合にブレーキ手段による制動準備を行わせる。
【００１７】
更に、制御手段は、具体的には請求項４記載のように、ブレーキ手段による制動準備を予めブレーキ油圧を高めておくことで行う。
【００１８】
また、制御手段は、具体的には請求項５記載のように、少なくとも自車両と先行車との目標車間距離を求めて走行制御を行うものであって、制御手段は、先行車が存在する場合には第１の目標車間距離を求め、先々行車が存在する場合には第２の目標車間距離を求め、先行車のみが存在する場合には第１の目標車間距離を目標車間距離として設定し、先々行車が存在する場合には第１の目標車間距離と第２の目標車間距離とに応じて目標車間距離を設定する。
【００１９】
更に、請求項６記載のように報知通信手段を設ければ、制御手段がブレーキ手段による制動準備を行わせる状態であることを車内と車外の少なくともどちらかに報知又は通信することが可能となる。
【００２０】
【発明の実施の形態】
以下、図面に基づいて本発明の実施の形態を説明する。
図１乃至図４は本発明の実施の一形態を示し、図１は車両に搭載した車両用運転支援装置の概略構成図、図２は運転支援制御プログラムのフローチャート、図３は先々行車抽出ルーチンのフローチャート、図４は目標車間距離算出ルーチンのフローチャートである。
【００２１】
図１において、符号１は自動車等の車両（自車両）で、この車両１には、車両用運転支援装置の一例としての車間距離制御機能付きクルーズコントロールシステム（ＡＣＣ（Ａｄａｐｔｉｖｅ　Ｃｒｕｉｓｅ　Ｃｏｎｔｒｏｌ）システム）２が搭載されている。このＡＣＣシステム２は、ステレオカメラ３、ミリ波レーダの送受信部４、測距処理装置５、前方情報認識装置６、制御装置７を有して主要に構成されている。そして、ＡＣＣシステム２は、詳しくは後述の図２の運転支援制御プログラムにより制御されるが、基本的に、先行車が存在しない定速走行制御状態のときにはドライバが設定した車速を保持した状態で走行し、先行車が存在する追従走行制御状態のときには、先行車と先々行車の存在に応じて自車両１と先行車との目標車間距離を求め、この目標車間距離を保持した状態で走行制御する。
【００２２】
ステレオカメラ３は、ステレオ光学系として例えば電荷結合素子（ＣＣＤ）等の固体撮像素子を用いた１組の（左右の）ＣＣＤカメラで構成され、これら左右のＣＣＤカメラは、それぞれ車室内の天井前方に一定の間隔をもって取り付けられ、車外の対象を異なる視点からステレオ撮像し、前方情報認識装置６に信号出力する。
【００２３】
また、自車両１の先端には、前方に所定にミリ波（３０ＧＨｚ〜１００ＧＨｚの電波）を送信し、更に、反射して戻ってくるミリ波を受信するミリ波レーダの送受信部４が設けられ、この送受信データは測距処理装置５に入力される。
【００２４】
測距処理装置５は、送受信部４がミリ波を送信し、目標で反射して戻ってくる受信波との時間差を基に、自車両１から目標までの相対距離を計測し、これら相対距離情報を前方情報認識装置６に出力する。
【００２５】
前方情報認識装置６は、上述のステレオカメラ３、測距処理装置５に加え、車速センサ８、ハンドル角センサ９、ヨーレートセンサ１０が接続されており、これら各センサ８，９，１０から自車速Ｖ０，ハンドル角θＨ，ヨーレートγがそれぞれ入力される。
【００２６】
そして、前方情報認識装置６は、ステレオカメラ３からの画像に基づき自車両１前方の立体物データと側壁データと白線データの前方情報を検出し、これら前方情報や自車両１の運転状態（ハンドル角θＨやヨーレートγ）から、自車両１の進行路（自車進行路）を推定する。こうして推定した自車進行路や前方情報から自車両１の走行領域を推定し、この自車走行領域と自車両１からの距離等を基に、自車両１前方の先行車を抽出し、この先行車との車間距離、先行車速（＝相対速度＋自車速）、先行車以外の立体物位置等の各データを求める。
【００２７】
ここで、前方情報認識装置６における、ステレオカメラ３からの画像の処理は、例えば以下のように行われる。まず、ステレオカメラ３のＣＣＤカメラで撮像した自車両の進入方向の環境の１組のステレオ画像対に対し、対応する位置のずれ量から三角測量の原理によって画像全体に渡る距離情報を求める処理を行なって、三次元の距離分布を表す距離画像を生成する。そして、このデータを基に、周知のグルーピング処理や、予め記憶しておいた３次元的な道路形状データ、立体物データ等と比較し、白線データ、道路に沿って存在するガードレール、縁石等の側壁データ、車両等の立体物データを抽出する。立体物データでは、立体物までの距離と、この距離の時間的変化（自車両１に対する相対速度）が求められ、例えば、自車進行路上にある最も近い車両で、自車両１と略同じ方向に所定の速度で進行するものが先行車として抽出される。
【００２８】
また、前方情報認識装置６は、測距処理装置５からの相対距離情報に基づき、距離値の分布状態から同一の距離値が連続する部分を一つの立体物として抽出し、各抽出した立体物の中から距離値の変化量（自車両１との相対速度）と自車両１からの距離に基づき自車両１に対する先行車を抽出し、自車速Ｖ０に基づく先行車速（＝相対速度＋自車速Ｖ０）と先行車距離を演算する。
【００２９】
こうして、ステレオカメラ３からの画像に基づき得られた先行車情報と測距処理装置５からの相対距離情報に基づき得られた先行車情報とは、統合処理（例えば、それぞれの先行車情報の位置と速度で同一となる確率が所定に演算され、この同一確率が予め設定した閾値以上の先行車情報が真の先行車情報として登録される）が行われる。
【００３０】
この前方情報認識装置６で統合された先行車情報は、以下、図３のフローチャートに示す先々行車抽出ルーチンに従って、先々行車の抽出に利用される。すなわち、まず、ステップ（以下、「Ｓ」と略称）２０１において、自車両１の走行領域や先行車情報等の必要パラメータの読み込みが行われ、Ｓ２０２に進んで、先行車が存在するか否か判定される。
【００３１】
Ｓ２０２の判定の結果、先行車が存在しない場合は、ルーチンを抜け、先行車が存在する場合には、Ｓ２０３に進む。
【００３２】
Ｓ２０３では、判定対象とする立体物が先行車と同一か否か判定し、同一でなければＳ２０４に進み、判定対象とする立体物が先行車より遠方に存在するか否か判定する。
【００３３】
Ｓ２０４の判定の結果、判定対象とする立体物が先行車より遠方に存在する場合は、Ｓ２０５に進み、判定対象とする立体物が自車走行領域に進入したか否か判定し、自車走行領域に進入している場合はＳ２０６に進んで、判定対象とする立体物が自車両１に最も近い立体物か否か判定する。
【００３４】
そして、Ｓ２０６の判定の結果、判定対象とする立体物が自車両１に最も近い立体物であればＳ２０７に進んで先々行車として登録する。
【００３５】
一方、Ｓ２０３で判定対象とする立体物が先行車と同一、或いは、Ｓ２０４で判定対象とする立体物が先行車より遠方には存在しない、或いは、Ｓ２０５で判定対象とする立体物が自車走行領域に進入していない、或いは、Ｓ２０６で判定対象とする立体物が自車両１に最も近い立体物ではないの何れか判定結果の場合は、Ｓ２０８に進み、判定対象とする立体物は先々行車ではないと判定する。
【００３６】
而して、Ｓ２０７で判定対象とする立体物を先々行車として登録、或いは、Ｓ２０８で判定対象とする立体物は先々行車ではないと判定した後は、Ｓ２０９に進み、全立体物についての判定が終了したか否か判定し、全立体物についての判定が終了していればルーチンを抜け、全立体物についての判定が終了していないのであればＳ２０３からの処理を繰り返す。
【００３７】
このように本発明の実施の形態では、先々行車の判定を、先行車と同一ではなく、且つ、該検出した先行車よりも遠方に存在し、且つ、自車両１の走行領域に進入した自車両１に最も近い位置に存在する前方立体物を先々行車として検出するようにしているので、特に大規模なインフラストラクチュアのない道路でも車載のシステムで容易且つ正確に先々行車の検出を行うことができ、汎用性の非常に優れたシステムとなっている。尚、Ｓ２０３〜Ｓ２０６の処理の順番は本実施の形態以外の順番であっても良い。
【００３８】
そして、前方情報認識装置６は、上述の如く先々行車を抽出した後は、先行車情報と同様に、先々行車との車間距離、及び、先々行車との車間距離の変化量と自車速Ｖ０から先々行車速等を先々行車情報として算出し、この先々行車情報を先行車情報と共に、制御装置７に出力する。すなわち、本実施の形態においては、ステレオカメラ３、ミリ波レーダの送受信部４、測距処理装置５、前方情報認識装置６で、前方情報認識手段、先行車情報検出手段、先々行車情報検出手段が構成されている。
【００３９】
制御装置７は、制御手段としてのものであり、ドライバの操作入力によって設定される走行速度を維持するよう定速走行制御を行なう定速走行制御の機能、及び自車両１と先行車の車間距離を一定の目標車間距離に保持した状態で走行する追従走行制御の機能を実現するもので、ステアリングコラムの側部等に設けられた定速走行操作レバーに連結される複数のスイッチ類で構成された定速走行スイッチ１１、上述の前方情報認識装置６、車速センサ８が接続されている。
【００４０】
定速走行スイッチ１１は、定速走行時の目標車速を設定する車速セットスイッチ、主に目標車速を下降側へ変更設定するコーストスイッチ、主に目標車速を上昇側へ変更設定するリジュームスイッチ等で構成されている。更に、この定速走行操作レバーの近傍には、走行制御のＯＮ／ＯＦＦを行うメインスイッチ（図示せず）が配設されている。
【００４１】
ドライバが図示しないメインスイッチをＯＮし、定速走行操作レバーにより、希望する速度をセットすると、定速走行スイッチ１１からの信号が制御装置７に入力される。そして、車速センサ８で検出した自車速Ｖ０が、ドライバのセットした設定車速に収束するように、スロットル弁制御装置１２に信号出力してスロットル弁１３の開度をフィードバック制御し、或いは、ブレーキ手段としてのハイドロリックユニットを有した自動ブレーキ制御装置１４に減速信号を出力して自動ブレーキを作動させ、自車両１を自動的に定速状態で走行させる。この定速走行は、ドライバの所定の運転動作、すなわち、ブレーキペダルの踏み込みや、メインスイッチのＯＦＦ等により解除される。
【００４２】
又、制御装置７は、定速走行制御を行っている際に、前方情報認識装置６にて先行車を認識した場合には、後述の図２の運転支援制御プログラムに従って、先行車と先々行車との関係により、図４の目標車間距離算出ルーチンで算出した目標車間距離を保持した状態で走行する追従走行制御へ自動的に切換えられる。
【００４３】
以下、図２の運転支援制御プログラムのフローチャートにより、制御装置７における運転支援制御を具体的に説明する。
まず、Ｓ１０１で、必要パラメータ、具体的には、自車速Ｖ０、先行車の有無、先行車と自車両１との車間距離Ｌａ、先行車速Ｖａ、先々行車の有無、先々行車と自車両１との車間距離Ｌｂ、先々行車速Ｖｂを読み込む。
【００４４】
次いで、Ｓ１０２に進み、先行車が存在するか否か判定し、先行車が存在しない場合はＳ１０３に進み、通常の運転支援制御を行うよう設定し、プログラムを抜ける。ここで、通常の運転支援制御とは、すなわち上述したように、車速センサ８で検出した自車速Ｖ０が、ドライバのセットした設定車速に収束するように、スロットル弁制御装置１２に信号出力してスロットル弁１３の開度をフィードバック制御し、或いは、自動ブレーキ制御装置１４に減速信号を出力して自動ブレーキを作動させ、自車両１を自動的に定速状態で走行させる。この定速走行は、ドライバの所定の運転動作、すなわち、ブレーキペダルの踏み込みや、メインスイッチのＯＦＦ等により解除される。
【００４５】
上述のＳ１０２で先行車が存在すると判定した場合には、Ｓ１０４に進み、先々行車が存在するか否か判定し、先々行車が存在しない場合はＳ１０３に進み、通常の運転支援制御を行うよう設定し、プログラムを抜ける。ここで、先行車が存在し、先々行車が存在しない場合の通常の運転支援制御は、基本的には、後述（Ｓ１０６で詳述）の図４の目標車間距離算出ルーチンで目標車間距離を算出し、先行車と自車両１との車間距離Ｌａが目標車間距離になるように、スロットル弁制御装置１２に信号出力してスロットル弁１３の開度をフィードバック制御し、或いは、自動ブレーキ制御装置１４に減速信号を出力して自動ブレーキを作動させ制御する。
【００４６】
一方、Ｓ１０４で先々行車が存在すると判定した場合は、Ｓ１０５に進み、車載のモニタ１５上に、先々行車が先行車の前方に存在することを、先々行車速Ｖｂや、先々行車と自車両１との車間距離Ｌｂと共に表示する。これにより、ドライバは、先行車の前にさらに車両が存在することを知ることが可能となり、先行車を追い越す際の参考としたり、先行車がブレーキをかけることに備えて運転したりすることが可能となる。尚、モニタ１５に表示するのみならず、音声や警報等でドライバに報知するようにしても良い。
【００４７】
その後、Ｓ１０６に進むと、先行車と先々行車を考慮した運転支援制御が実行される。この先行車と先々行車を考慮した運転支援制御は、図４の目標車間距離算出ルーチンで先々行車の存在をも考慮して目標車間距離を算出し、この目標車間距離を基に、Ｓ１０３で説明した通常の運転支援制御と同様に、スロットル弁制御装置１２に信号出力してスロットル弁１３の開度をフィードバック制御し、或いは、自動ブレーキ制御装置１４に減速信号を出力して自動ブレーキを作動させ、自車両１を自動的に定速状態で走行させるものである。
【００４８】
すなわち、図４の目標車間距離算出ルーチンでは、まず、Ｓ３０１で、必要パラメータ、具体的には、自車速Ｖ０、先行車の有無、先行車と自車両１との車間距離Ｌａ、先行車速Ｖａ、先々行車の有無、先々行車と自車両１との車間距離Ｌｂ、先々行車速Ｖｂ等を読み込む。
【００４９】
次いで、Ｓ３０２に進み、先行車が存在するか否か判定し、先行車が存在しない場合は、Ｓ３０３に進み、目標車間距離を設定することなく、ルーチンを抜ける。
【００５０】
また、Ｓ３０２で先行車が存在すると判定した場合はＳ３０４に進み、先行車に基づき目標車間距離Ｄ１（第１の目標車間距離）を算出する。ここで、目標車間距離Ｄ１は、運転状態に応じて、例えば以下の２種類のものを設定しておく。
【００５１】
すなわち、通常の運転状態における目標車間距離として、
Ｄ１＝Ｄ０＋Ｖ０・Ｔｃ　　…（１）
また、先行車追尾状態から減速又は停止状態に移行する運転状態における目標車間距離として、
Ｄ１＝Ｄ０＋Ｖ０・Ｔｃ＋（Ｖ０^２−Ｖａ^２）／（２・ａ）　…（２）
ここで、Ｄ０は停止時の車間距離、Ｔｃは空走時間、ａは自車両１の減速度である。
【００５２】
次いで、Ｓ３０５に進むと、先々行車が存在するか否か判定し、先々行車が存在しない場合にはＳ３０９へとジャンプし、そのまま上述の（１）式、或いは、（２）式で求めた目標車間距離Ｄ１を出力してルーチンを抜ける。このような先行車が存在するが、先々行車が存在しない場合の目標車間距離Ｄ１は、上述の図２のフローチャートにおいて、Ｓ１０２からＳ１０４を経て、すなわち、先行車が存在するが先々行車が存在しない場合で、Ｓ１０３に達した際に実行される通常の運転支援制御で用いられることになる。
【００５３】
一方、上述のＳ３０５で、先々行車が存在すると判定した場合はＳ３０６に進み、先々行車を考慮して、先行車との目標車間距離Ｄ２（第２の目標車間距離）を算出する。ここで、目標車間距離Ｄ２は、上述の目標車間距離Ｄ１同様、運転状態に応じて、例えば以下の２種類のものを設定しておく。
【００５４】
すなわち、通常の運転状態における目標車間距離として、
Ｄ２＝Ｄ０＋Ｄ３＋Ｖ０・Ｔｃ　　…（３）
また、先行車追尾状態から減速又は停止状態に移行する運転状態における目標車間距離として、
Ｄ２＝Ｄ０＋Ｄ３＋Ｖ０・Ｔｃ＋（Ｖ０^２−Ｖｂ^２）／（２・ａ）　…（４）
ここで、Ｄ３は先行車を考慮した車間距離である。
【００５５】
その後、Ｓ３０７に進み、先行車に基づく目標車間距離Ｄ１と、先々行車を考慮した先行車との目標車間距離Ｄ２とを比較し、Ｄ１＜Ｄ２であればＳ３０８に進んで、Ｄ１＝Ｄ２とし、Ｓ３０９に進んで、この目標車間距離Ｄ１を出力してルーチンを抜ける。逆に、Ｄ１≧Ｄ２であれば、そのままＳ３０９にジャンプして、目標車間距離Ｄ１を出力してルーチンを抜ける。
【００５６】
すなわち、通常の運転状態においては、（１）式、及び、（３）式からも明らかなように、Ｄ１＜Ｄ２となって先々行車を考慮した先行車との目標車間距離Ｄ２を目標車間距離として出力する。しかしながら、先行車追尾状態から減速又は停止状態に移行する運転状態においては、（２）式、及び、（４）式からも明らかなように、先行車速Ｖａと先々行車速Ｖｂの関係が、Ｖａ≧Ｖｂの場合は、確実にＤ１＜Ｄ２となるが、Ｖａ＜Ｖｂの場合で特にこの差が大きい場合には、Ｄ１≧Ｄ２となる可能性があり、このような場合には、大きい方の、先行車に基づく目標車間距離Ｄ１をそのまま用いて目標車間距離とするのである。
【００５７】
本実施の形態では、このように、先行車に基づく目標車間距離Ｄ１と、先々行車を考慮した先行車との目標車間距離Ｄ２とに応じて目標車間距離を安全側に設定するので、先々行車が存在する場合には、その状況に応じた最適な目標車間距離が設定されるようになっている。
【００５８】
こうして、Ｓ１０６で、上述の目標車間距離に基づく先々行車を用いた運転支援制御の実行を定めた後は、Ｓ１０７に進み、先行車と先々行車の車間距離Ｌａｂ（＝Ｌｂ−Ｌａ）が予め設定しておいた閾値Ｋ１以上か否か判定する。そして、この判定の結果、先行車と先々行車の車間距離Ｌａｂが、予め設定しておいた閾値Ｋ１以上（Ｌａｂ≧Ｋ１）であれば、そのままルーチンを抜け、Ｓ１０３の先々行車を用いた運転支援制御を実行する。
【００５９】
Ｓ１０７の判定の結果、先行車と先々行車の車間距離Ｌａｂが、予め設定しておいた閾値Ｋ１より小さい場合（Ｌａｂ＜Ｋ１の場合）は、Ｓ１０８に進み、先行車速Ｖａと先々行車速Ｖｂとの比較を行う。
【００６０】
Ｓ１０８の比較の結果、先行車速Ｖａが先々行車速Ｖｂ以下（Ｖａ≦Ｖｂ）の場合は、そのままルーチンを抜け、Ｓ１０３の先々行車を用いた運転支援制御を実行する。
【００６１】
逆に、先行車速Ｖａが先々行車速Ｖｂより高い（Ｖａ＞Ｖｂ）の場合は、Ｓ１０９に進み、Ｓ１０３における運転支援制御で加速を実行しようとした場合には、その加速を抑制する（例えば、目標とする加速度を５０％に減じる）処理を実行させる。すなわち、先行車と先々行車との車間距離が閾値Ｋ１より短く、先行車速Ｖａが先々行車速Ｖｂよりも高い場合には、先行車が先々行車に追いついてブレーキをかける可能性があるため、これを考慮した追従走行を行わせるのである。
【００６２】
その後、Ｓ１１０に進み、先行車と先々行車の車間距離Ｌａｂが、予め設定しておいた閾値Ｋ２（＜Ｋ１）以上か否か判定する。そして、この判定の結果、先行車と先々行車の車間距離Ｌａｂが、予め設定しておいた閾値Ｋ２以上（Ｌａｂ≧Ｋ２）であれば、そのまま（加速を抑制するのみで）ルーチンを抜ける。逆に、先行車と先々行車の車間距離Ｌａｂが、予め設定しておいた閾値Ｋ２より小さい（Ｌａｂ＜Ｋ２）のであれば、Ｓ１１１に進み、先行車速Ｖａから先々行車速Ｖｂを減算した値（＝Ｖａ−Ｖｂ）が、予め設定しておいた速度値Ｖｃ１以上か否か判定する。
【００６３】
Ｓ１１１の判定の結果、（Ｖａ−Ｖｂ）が、予め設定しておいた速度値Ｖｃ１より小さければ、そのまま（加速を抑制するのみで）ルーチンを抜ける。逆に、（Ｖａ−Ｖｂ）が、予め設定しておいた速度値Ｖｃ１以上であれば、すなわち換言すれば、先行車が先々行車に急接近している状態であれば、Ｓ１１２に進み、自動ブレーキ制御装置１４に信号出力して、予めブレーキ油圧を高め制動準備を行わせ、レスポンス良くブレーキをかけられる状態としてルーチンを抜ける。尚、このＳ１１２の処理においては、モニタ１５上に自車両１が制動準備中であることをドライバにランプ点滅等で報知するようにしても良い。また、特に図示はしないが、単にモニタ１５でドライバに報知するのみならず、自車両１の周囲の車両やインフラストラクチュアに対し、自車両１が制動準備中であることをランプの点灯や通信装置により報知するように構成しても良い。
【００６４】
このように、本実施の形態によれば、先行車、並びに、先々行車が存在する場合の運転支援制御において、先行車と先々行車との車間距離が接近し、更に、先行車が先々行車に対して急接近するような場合は、予めブレーキ油圧を高め制動準備を行わせる制御が行われるため、例え、先行車が先々行車の存在により急ブレーキをかけるような場合でもレスポンスの良いブレーキ制御が行われる。
【００６５】
また、単純に、加速制御と減速制御を条件により設定するものではないため、前方を視認しながら運転するドライバに対し、自然で違和感のない運転支援が行える。
【００６６】
尚、本実施の形態においては、ステレオカメラ３、ミリ波レーダの送受信部４、測距処理装置５、前方情報認識装置６で、前方情報、先行車情報、先々行車情報の検出を行うようにしているが、これに限ることなく、例えば、ステレオカメラ３、前方情報認識装置６のみで各情報を得られるように構成しても良く、また、レーダ装置もミリ波に限ることなく、他の波長（例えば赤外線レーザ）のレーダ装置等を用いて実現するようにしても良い。
【００６７】
【発明の効果】
以上説明したように本発明によれば、特に大規模なインフラストラクチュアのない道路でも容易に採用でき汎用性に優れ、実際に減速を行うまでもない状況下にあっては減速に備え、必要なときには確実にレスポンス良く減速して安全性が極めて高く、ドライバに対して自然で違和感のない運転支援ができるという優れた効果を奏する。
【図面の簡単な説明】
【図１】車両に搭載した車両用運転支援装置の概略構成図
【図２】運転支援制御プログラムのフローチャート
【図３】先々行車抽出ルーチンのフローチャート
【図４】目標車間距離算出ルーチンのフローチャート
【符号の説明】
１　　自車両
２　　ＡＣＣシステム（車両用運転支援装置）
３　　ステレオカメラ（前方情報認識手段、先行車情報検出手段、先々行車情報検出手段）
４　　送受信部（前方情報認識手段、先行車情報検出手段、先々行車情報検出手段）
５　　測距処理装置（前方情報認識手段、先行車情報検出手段、先々行車情報検出手段）
６　　前方情報認識装置（前方情報認識手段、先行車情報検出手段、先々行車情報検出手段）
７　　制御装置（制御手段）
１１　　定速走行スイッチ
１４　　自動ブレーキ制御装置（ブレーキ手段）
１５　　モニタ（報知通信手段）[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention recognizes a road condition ahead of a vehicle by a forward recognition device such as an image recognition device such as a millimeter wave radar, an infrared laser radar, a stereo camera or a monocular camera, and automatically controls own vehicle speed and an inter-vehicle distance with a preceding vehicle. The present invention relates to a vehicle driving support device.
[0002]
[Prior art]
In recent years, for vehicles that recognize the road conditions ahead of the vehicle with forward recognition devices such as millimeter wave radar, infrared laser radar, image recognition devices such as stereo cameras and monocular cameras, and automatically control the own vehicle speed and the inter-vehicle distance with the preceding vehicle Driving assistance devices have been put to practical use.
[0003]
In such a vehicle driving support device, when controlling to follow the vehicle while maintaining the inter-vehicle distance to the preceding vehicle within the set distance range, the speed at the time of the following traveling is set to the speed of the preceding vehicle traveling further ahead of the preceding vehicle. It may become unstable under the influence of the running state of the car. For this reason, for example, in Japanese Patent Application Laid-Open No. 2001-199257, a distance to a preceding vehicle is measured, and inter-vehicle distance data indicating the positions of the own vehicle and the preceding vehicle is received from the roadside device of the driving support system. When determining the distance to the preceding vehicle based on the data and performing acceleration / deceleration control based on the inter-vehicle distance to the preceding vehicle, the own vehicle follows the preceding vehicle and performs the acceleration / deceleration control. There is disclosed a technique for performing control in consideration of an inter-vehicle distance with a pre-preceding vehicle.
[0004]
[Patent Document 1]
JP 2001-199257 A
[0005]
[Problems to be solved by the invention]
However, the prior art described above has a problem that versatility is extremely low, because the prior art vehicle can be captured only on a traveling road on which a driving support system is provided and an infrastructure is prepared. In addition, since acceleration control and deceleration control are performed according to the distance between the host vehicle and the preceding vehicle and the distance between the host vehicle and the preceding vehicle, acceleration and deceleration occur unnaturally depending on tuning, There is a possibility that the driver who actually drives the vehicle while visually confirming the front may feel uncomfortable.
[0006]
The present invention has been made in view of the above circumstances, in particular, it can be easily adopted even on a road without a large-scale infrastructure, has excellent versatility, and prepares for deceleration in a situation where there is no need to actually decelerate, It is an object of the present invention to provide a vehicle driving support device capable of providing a natural and comfortable driving support to a driver by ensuring deceleration with good response and extremely high safety when necessary.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a vehicle driving support device according to the present invention according to the present invention is based on vehicle-mounted forward information recognizing means for detecting and recognizing an environment ahead of a host vehicle, and based on forward information from the forward information recognizing means. Preceding vehicle information detecting means for detecting preceding vehicle information; and preceding vehicle information detecting means for detecting preceding vehicle information traveling further ahead of the preceding vehicle based on the forward information from the forward information recognizing means and the preceding vehicle information. And control means for executing travel control based on the forward information, the preceding vehicle information, and the pre-preceding vehicle information, and performing at least braking preparation by a braking means based on the preceding vehicle information and the pre-preceding vehicle information. It is characterized by:
[0008]
According to a second aspect of the present invention, there is provided a vehicle driving assistance apparatus according to the first aspect, wherein the preceding vehicle information detecting means is not the preceding vehicle detected by the preceding vehicle information detecting means. In addition, a three-dimensional object in front of the vehicle located farther than the detected preceding vehicle and closest to the host vehicle that has entered the travel area of the host vehicle is detected as the preceding vehicle.
[0009]
Further, in the vehicle driving support device according to the present invention described in claim 3, in the vehicle driving support device according to claim 1 or 2, the control means is arranged so that an inter-vehicle distance between the preceding vehicle and the preceding vehicle is reduced. When the vehicle approaches a predetermined distance and the speed of the preceding vehicle exceeds the speed of the preceding vehicle by more than a predetermined speed, the braking means is prepared for braking.
[0010]
According to a fourth aspect of the present invention, there is provided a vehicle driving assistance device according to any one of the first to third aspects, wherein the control means includes a step of preparing for braking by the braking means. Is performed by increasing the brake oil pressure in advance.
[0011]
According to a fifth aspect of the present invention, there is provided a vehicle driving support apparatus according to any one of the first to fourth aspects, wherein the control means includes at least the host vehicle and the preceding vehicle. The travel control is performed by obtaining a target inter-vehicle distance with a car, wherein the control means obtains a first target inter-vehicle distance when the preceding vehicle exists, and when the preceding two-way vehicle exists, A second target inter-vehicle distance is determined. If only the preceding vehicle is present, the first target inter-vehicle distance is set as the target inter-vehicle distance. If the preceding vehicle is present, the first target inter-vehicle distance is set. The target inter-vehicle distance is set according to the distance and the second target inter-vehicle distance.
[0012]
According to a sixth aspect of the present invention, there is provided the vehicle driving assistance apparatus according to any one of the first to fifth aspects, wherein the control means prepares for braking by the braking means. A notification communication means is provided for notifying or communicating at least one of the inside and the outside of the vehicle to be performed.
[0013]
In other words, the vehicle driving support device according to the first aspect of the present invention detects and recognizes the environment ahead of the own vehicle by the on-vehicle forward information recognizing means, and the preceding vehicle information detecting means based on the forward information from the forward information recognizing means. The vehicle information is detected, and the pre-vehicle information detecting means detects pre-vehicle information traveling further ahead of the preceding vehicle based on the front information from the front information recognition means and the preceding vehicle information. Then, the control unit executes the traveling control based on the forward information, the preceding vehicle information, and the pre-preceding vehicle information, and at least prepares for the braking by the brake unit based on the preceding vehicle information and the pre-preceding vehicle information.
[0014]
For this reason, it can be easily adopted especially on large-scale roads without infrastructure, has excellent versatility, prepares for deceleration in situations where there is no need to actually decelerate, and decelerates with good response when necessary. It is extremely safe and can provide natural and comfortable driving assistance to the driver. In particular, since the brakes are prepared immediately instead of braking immediately, acceleration and deceleration do not occur unnaturally. Can be expected and safety can be improved.
[0015]
In this case, the preceding vehicle information detecting means is not the preceding vehicle detected by the preceding vehicle information detecting means, and is more distant than the detected preceding vehicle, as described in claim 2, and By detecting the three-dimensional object in front of the host vehicle that has entered the travel area of the host vehicle as the preceding vehicle, the preceding vehicle can be reliably detected.
[0016]
Further, the control means may be configured such that the inter-vehicle distance between the preceding vehicle and the pre-preceding vehicle is closer than a preset distance, and the speed of the preceding vehicle is preset from the speed of the pre-preceding vehicle. When the speed exceeds the set speed, the braking means is prepared for braking.
[0017]
Further, the control means specifically performs the preparation for braking by the brake means by increasing the brake oil pressure in advance.
[0018]
Further, the control means specifically performs at least a target inter-vehicle distance between the host vehicle and the preceding vehicle to perform travel control, and the control means includes the preceding vehicle. In this case, the first target inter-vehicle distance is obtained. If there is a preceding vehicle, the second target inter-vehicle distance is obtained. If only the preceding vehicle is present, the first target inter-vehicle distance is set as the target inter-vehicle distance. If a preceding vehicle is present, the target inter-vehicle distance is set according to the first target inter-vehicle distance and the second target inter-vehicle distance.
[0019]
Further, if the notification communication means is provided as described in claim 6, it is possible to notify or communicate at least one of the inside and the outside of the vehicle that the control means is ready for braking by the brake means. .
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 4 show an embodiment of the present invention. FIG. 1 is a schematic configuration diagram of a vehicle driving assistance device mounted on a vehicle, FIG. 2 is a flowchart of a driving assistance control program, and FIG. FIG. 4 is a flowchart of a target inter-vehicle distance calculation routine.
[0021]
In FIG. 1, reference numeral 1 denotes a vehicle such as an automobile (own vehicle), and the vehicle 1 has a cruise control system (ACC (Adaptive Cruise Control) system) 2 with an inter-vehicle distance control function as an example of a vehicle driving assistance device. Is installed. The ACC system 2 mainly includes a stereo camera 3, a millimeter wave radar transmission / reception unit 4, a distance measurement processing device 5, a forward information recognition device 6, and a control device 7. The ACC system 2 is controlled by a driving support control program shown in FIG. 2 which will be described later in detail. Basically, when the vehicle is in a constant speed traveling control state in which there is no preceding vehicle, the vehicle speed set by the driver is maintained. When the vehicle is traveling and in a following traveling control state in which a preceding vehicle exists, a target inter-vehicle distance between the host vehicle 1 and the preceding vehicle is obtained in accordance with the existence of the preceding vehicle and the preceding vehicle, and the traveling control is performed in a state where the target inter-vehicle distance is maintained. I do.
[0022]
The stereo camera 3 is composed of a pair of (left and right) CCD cameras using a solid-state image pickup device such as a charge-coupled device (CCD) as a stereo optical system. At predetermined intervals, stereoscopically image the object outside the vehicle from different viewpoints, and output a signal to the forward information recognition device 6.
[0023]
Further, a transmitting / receiving unit 4 of a millimeter wave radar for transmitting a predetermined millimeter wave (a radio wave of 30 GHz to 100 GHz) forward and receiving a reflected and returning millimeter wave is provided at a front end of the vehicle 1. The transmission / reception data is input to the distance measurement processing device 5.
[0024]
The distance measurement processing device 5 measures the relative distance from the host vehicle 1 to the target based on the time difference between the transmitting and receiving unit 4 transmitting the millimeter wave and the received wave reflected by the target and returning. The information is output to the forward information recognition device 6.
[0025]
The front information recognition device 6 is connected to a vehicle speed sensor 8, a steering wheel angle sensor 9, and a yaw rate sensor 10 in addition to the stereo camera 3 and the distance measurement processing device 5 described above. V0, steering wheel angle θH, and yaw rate γ are input.
[0026]
The forward information recognition device 6 detects three-dimensional object data, side wall data, and white line data ahead of the vehicle 1 based on the image from the stereo camera 3 and detects the forward information and the driving state of the vehicle 1 (the steering wheel). From the angle θH and the yaw rate γ), the traveling path of the host vehicle 1 (host vehicle traveling path) is estimated. The traveling area of the host vehicle 1 is estimated from the host vehicle traveling path and the forward information thus estimated, and a preceding vehicle ahead of the host vehicle 1 is extracted based on the distance from the host vehicle traveling area and the host vehicle 1. Each data such as an inter-vehicle distance to a preceding vehicle, a preceding vehicle speed (= relative speed + own vehicle speed), and a position of a three-dimensional object other than the preceding vehicle is obtained.
[0027]
Here, the processing of the image from the stereo camera 3 in the forward information recognition device 6 is performed, for example, as follows. First, for a pair of stereo images of the environment in the approach direction of the vehicle captured by the CCD camera of the stereo camera 3, a process of obtaining distance information over the entire image from the corresponding positional deviation amount by the principle of triangulation. To generate a distance image representing a three-dimensional distance distribution. Based on this data, a well-known grouping process is performed, and the data is compared with pre-stored three-dimensional road shape data, three-dimensional object data, and the like, and white line data, guardrails, curbs, and the like existing along the road. Extracts three-dimensional object data such as side wall data and vehicles. In the three-dimensional object data, a distance to the three-dimensional object and a temporal change in the distance (relative speed with respect to the own vehicle 1) are obtained. At a predetermined speed are extracted as preceding vehicles.
[0028]
Further, the forward information recognition device 6 extracts a portion where the same distance value continues from the distance value distribution state as one three-dimensional object based on the relative distance information from the distance measurement processing device 5, and extracts each extracted three-dimensional object. , A preceding vehicle with respect to the own vehicle 1 is extracted based on the amount of change in the distance value (relative speed with respect to the own vehicle 1) and the distance from the own vehicle 1, and the preceding vehicle speed based on the own vehicle speed V0 (= relative speed + own vehicle speed) V0) and the preceding vehicle distance are calculated.
[0029]
Thus, the preceding vehicle information obtained based on the image from the stereo camera 3 and the preceding vehicle information obtained based on the relative distance information from the distance measurement processing device 5 are integrated (for example, the position of each preceding vehicle information). Is calculated in advance, and the preceding vehicle information having the same probability equal to or greater than a preset threshold is registered as true preceding vehicle information).
[0030]
The preceding vehicle information integrated by the forward information recognition device 6 is used for extracting a pre-preceding vehicle according to a pre-preceding vehicle extraction routine shown in the flowchart of FIG. That is, first, in step (hereinafter abbreviated as “S”) 201, necessary parameters such as the traveling area of the host vehicle 1 and the preceding vehicle information are read, and the process proceeds to S 202 to determine whether there is a preceding vehicle. Is determined.
[0031]
If the result of determination in S202 is that there is no preceding vehicle, the routine exits. If there is a preceding vehicle, the flow proceeds to S203.
[0032]
In S203, it is determined whether or not the three-dimensional object to be determined is the same as the preceding vehicle. If not, the process proceeds to S204, and it is determined whether or not the three-dimensional object to be determined exists farther than the preceding vehicle.
[0033]
If the result of determination in S204 is that the three-dimensional object to be determined is farther than the preceding vehicle, the process proceeds to S205, and it is determined whether the three-dimensional object to be determined has entered the own vehicle traveling area, and the own vehicle travels. If the vehicle has entered the area, the process proceeds to S206, and it is determined whether or not the three-dimensional object to be determined is the three-dimensional object closest to the host vehicle 1.
[0034]
Then, as a result of the determination in S206, if the three-dimensional object to be determined is the three-dimensional object closest to the host vehicle 1, the process proceeds to S207 and is registered as the preceding vehicle.
[0035]
On the other hand, the three-dimensional object to be determined in S203 is the same as the preceding vehicle, or the three-dimensional object to be determined is not farther than the preceding vehicle in S204, or the three-dimensional object to be determined in S205 is the own vehicle. If it is determined that the three-dimensional object has not entered the area or the three-dimensional object to be determined is not the three-dimensional object closest to the host vehicle 1 in S206, the process proceeds to S208, and the three-dimensional object to be determined is Is not determined.
[0036]
Then, after the three-dimensional object to be determined is registered as a pre-preceding vehicle in S207, or after the three-dimensional object to be determined is not a pre-preceding vehicle in S208, the process proceeds to S209, and the determination for all three-dimensional objects is performed. It is determined whether or not the processing has been completed. If the determination has been completed for all three-dimensional objects, the process exits the routine. If the determination for all three-dimensional objects has not been completed, the processing from S203 is repeated.
[0037]
As described above, according to the embodiment of the present invention, the determination of the preceding vehicle is not the same as that of the preceding vehicle, and the determination is made that the vehicle is located farther than the detected preceding vehicle and has entered the traveling area of the own vehicle 1. Since the three-dimensional object in front located at the position closest to the vehicle 1 is detected as a pre-preceding vehicle, it is possible to easily and accurately detect the pre-preceding vehicle with a vehicle-mounted system, especially on a road without a large-scale infrastructure. This is a very versatile system. Note that the order of the processing of S203 to S206 may be an order other than the present embodiment.
[0038]
Then, after extracting the pre-preceding vehicle as described above, the forward information recognition device 6 calculates the inter-vehicle distance to the pre-preceding vehicle, the inter-vehicle distance to the pre-preceding vehicle, and the own vehicle speed V0, similarly to the preceding vehicle information. The pre-vehicle speed and the like are calculated as pre-vehicle information, and the pre-vehicle information is output to the control device 7 together with the preceding vehicle information. That is, in this embodiment, the stereo camera 3, the millimeter-wave radar transmitting / receiving unit 4, the distance measurement processing device 5, and the forward information recognition device 6 include forward information recognition means, preceding vehicle information detection means, and preceding vehicle information detection means. Is configured.
[0039]
The control device 7 serves as a control means, and has a function of constant speed traveling control for performing constant speed traveling control so as to maintain a traveling speed set by a driver's operation input, and a distance between the host vehicle 1 and a preceding vehicle. Is realized while maintaining a constant target inter-vehicle distance, and comprises a plurality of switches connected to a constant speed traveling operation lever provided on a side portion of a steering column or the like. The constant-speed traveling switch 11, the above-mentioned forward information recognition device 6, and the vehicle speed sensor 8 are connected.
[0040]
The constant speed traveling switch 11 is a vehicle speed set switch for setting a target vehicle speed during constant speed traveling, a coast switch for mainly changing and setting the target vehicle speed to a lower side, a resume switch for mainly changing and setting the target vehicle speed to a higher side, and the like. It is configured. Further, a main switch (not shown) for turning ON / OFF the traveling control is disposed near the constant-speed traveling operation lever.
[0041]
When the driver turns on a main switch (not shown) and sets a desired speed with the constant speed traveling operation lever, a signal from the constant speed traveling switch 11 is input to the control device 7. Then, a signal is output to the throttle valve control device 12 to feedback-control the opening degree of the throttle valve 13 so that the own vehicle speed V0 detected by the vehicle speed sensor 8 converges to the set vehicle speed set by the driver, or a braking means. A deceleration signal is output to the automatic brake control device 14 having a hydraulic unit as a function to activate the automatic brake, and the host vehicle 1 automatically runs at a constant speed. This constant speed traveling is released by a predetermined driving operation of the driver, that is, by depressing the brake pedal, turning off the main switch, or the like.
[0042]
When the front information recognition device 6 recognizes the preceding vehicle during the constant-speed running control, the control device 7 controls the preceding vehicle and the two-preceding vehicle according to a driving support control program shown in FIG. Is automatically switched to the follow-up traveling control that travels while maintaining the target inter-vehicle distance calculated in the target inter-vehicle distance calculation routine of FIG.
[0043]
Hereinafter, the driving support control in the control device 7 will be specifically described with reference to the flowchart of the driving support control program of FIG.
First, in S101, necessary parameters, specifically, the own vehicle speed V0, the presence or absence of a preceding vehicle, the inter-vehicle distance La between the preceding vehicle and the own vehicle 1, the preceding vehicle speed Va, the presence or absence of a preceding vehicle, the relationship between the preceding vehicle and the own vehicle 1, , And the preceding vehicle speed Vb is read.
[0044]
Next, the process proceeds to S102, where it is determined whether or not there is a preceding vehicle. If there is no preceding vehicle, the process proceeds to S103, where normal driving support control is set, and the program exits. Here, the normal driving support control means that, as described above, a signal is output to the throttle valve control device 12 so that the own vehicle speed V0 detected by the vehicle speed sensor 8 converges to the set vehicle speed set by the driver. The degree of opening of the throttle valve 13 is feedback-controlled, or a deceleration signal is output to the automatic brake control device 14 to activate the automatic brake, thereby causing the host vehicle 1 to automatically run at a constant speed. This constant speed traveling is released by a predetermined driving operation of the driver, that is, by depressing the brake pedal, turning off the main switch, or the like.
[0045]
If it is determined in S102 that there is a preceding vehicle, the process proceeds to S104, and it is determined whether there is a preceding vehicle. If there is no preceding vehicle, the process proceeds to S103, and a setting is made to perform normal driving support control. And exit the program. Here, the normal driving support control when the preceding vehicle exists and the preceding vehicle does not exist basically calculates the target inter-vehicle distance by the target inter-vehicle distance calculation routine of FIG. 4 described later (detailed in S106). Then, a signal is output to the throttle valve control device 12 to feedback-control the opening of the throttle valve 13 so that the inter-vehicle distance La between the preceding vehicle and the host vehicle 1 becomes the target inter-vehicle distance, or the automatic brake control device 14 To output the deceleration signal to operate and control the automatic brake.
[0046]
On the other hand, if it is determined in S104 that there is a pre-preceding vehicle, the process proceeds to S105, and the fact that the pre-preceding vehicle is ahead of the preceding vehicle is indicated on the in-vehicle monitor 15 by the pre-vehicle speed Vb or the pre-preceding vehicle and the host vehicle 1. Is displayed together with the inter-vehicle distance Lb. This makes it possible for the driver to know that there is another vehicle in front of the preceding vehicle, to use it as a reference when overtaking the preceding vehicle or to drive in preparation for the preceding vehicle to apply the brake. It becomes possible. It should be noted that not only the display on the monitor 15 but also the notification to the driver by a sound or an alarm may be made.
[0047]
Thereafter, when the process proceeds to S106, the driving support control in consideration of the preceding vehicle and the preceding vehicle is executed. In the driving support control in consideration of the preceding vehicle and the preceding vehicle, the target inter-vehicle distance is calculated in consideration of the existence of the preceding vehicle in the target inter-vehicle distance calculation routine of FIG. In the same manner as the normal driving support control described above, a signal is output to the throttle valve control device 12 to feedback-control the opening degree of the throttle valve 13, or a deceleration signal is output to the automatic brake control device 14 to activate the automatic brake. The self-vehicle 1 automatically runs at a constant speed.
[0048]
That is, in the target inter-vehicle distance calculation routine of FIG. 4, first, in S301, the necessary parameters, specifically, the own vehicle speed V0, the presence or absence of the preceding vehicle, the inter-vehicle distance La between the preceding vehicle and the own vehicle 1, the preceding vehicle speed Va, The presence / absence of a preceding vehicle, the inter-vehicle distance Lb between the preceding vehicle and the own vehicle 1, the preceding vehicle speed Vb, and the like are read.
[0049]
Next, the process proceeds to S302, in which it is determined whether or not there is a preceding vehicle. If there is no preceding vehicle, the process proceeds to S303, and the routine exits without setting the target inter-vehicle distance.
[0050]
If it is determined in S302 that there is a preceding vehicle, the process proceeds to S304, and a target inter-vehicle distance D1 (first target inter-vehicle distance) is calculated based on the preceding vehicle. Here, for example, the following two types of target inter-vehicle distances D1 are set according to the driving state.
[0051]
That is, as the target inter-vehicle distance in a normal driving state,
D1 = D0 + V0 · Tc (1)
In addition, as the target inter-vehicle distance in the driving state of shifting from the preceding vehicle tracking state to the deceleration or stop state,
D1 = D0 + V0.Tc + (V0 ² -Va ² ) / (2 · a)… (2)
Here, D0 is the inter-vehicle distance when stopped, Tc is the idle running time, and a is the deceleration of the vehicle 1.
[0052]
Next, when the process proceeds to S305, it is determined whether or not there is a pre-vehicle, and if there is no pre-vehicle, the process jumps to S309, and the target obtained by the above equation (1) or (2) is used as it is. Output the inter-vehicle distance D1 and exit the routine. The target inter-vehicle distance D1 in the case where such a preceding vehicle exists but the preceding vehicle does not exist is obtained through S102 to S104 in the above-described flowchart of FIG. 2, that is, the preceding vehicle exists but the preceding vehicle does not exist. In this case, it will be used in the normal driving support control executed when S103 is reached.
[0053]
On the other hand, if it is determined in S305 that there is a pre-preceding vehicle, the process proceeds to S306, and a target inter-vehicle distance D2 (second target inter-vehicle distance) with the preceding vehicle is calculated in consideration of the pre-vehicle. Here, as the target inter-vehicle distance D2, for example, the following two types are set according to the driving state, similarly to the above-described target inter-vehicle distance D1.
[0054]
That is, as the target inter-vehicle distance in a normal driving state,
D2 = D0 + D3 + V0 · Tc (3)
In addition, as the target inter-vehicle distance in the driving state of shifting from the preceding vehicle tracking state to the deceleration or stop state,
D2 = D0 + D3 + V0.Tc + (V0 ² -Vb ² ) / (2 · a)… (4)
Here, D3 is an inter-vehicle distance in consideration of the preceding vehicle.
[0055]
Thereafter, the process proceeds to S307, in which the target inter-vehicle distance D1 based on the preceding vehicle is compared with the target inter-vehicle distance D2 to the preceding vehicle in consideration of the pre-preceding vehicle. Proceeding to S309, this target inter-vehicle distance D1 is output, and the routine exits. Conversely, if D1 ≧ D2, the process jumps to S309 as it is, outputs the target inter-vehicle distance D1, and exits the routine.
[0056]
That is, in a normal driving state, as is clear from the equations (1) and (3), the target inter-vehicle distance D2 with respect to the preceding vehicle considering D2 <D2 is considered as the target inter-vehicle distance. Is output as However, in the driving state in which the vehicle shifts from the preceding vehicle tracking state to the deceleration or stop state, as is clear from the expressions (2) and (4), the relationship between the preceding vehicle speed Va and the preceding vehicle speed Vb is Va ≧ In the case of Vb, D1 <D2 is ensured. However, in the case of Va <Vb, especially when this difference is large, D1 ≧ D2 may be satisfied. The target inter-vehicle distance D1 based on the preceding vehicle is directly used as the target inter-vehicle distance.
[0057]
In this embodiment, the target inter-vehicle distance is set on the safe side in accordance with the target inter-vehicle distance D1 based on the preceding vehicle and the target inter-vehicle distance D2 with respect to the preceding vehicle in consideration of the preceding vehicle. Exists, an optimal target inter-vehicle distance is set according to the situation.
[0058]
After the execution of the driving support control using the pre-preceding vehicle based on the target inter-vehicle distance is determined in S106, the process proceeds to S107, and the inter-vehicle distance Lab (= Lb−La) between the preceding vehicle and the pre-preceding vehicle is set in advance. It is determined whether or not the threshold value K1 is equal to or greater than the set threshold value K1. If the result of this determination is that the inter-vehicle distance Lab between the preceding vehicle and the preceding vehicle is equal to or greater than a preset threshold K1 (Lab ≧ K1), the routine exits as it is and the driving support using the preceding vehicle in S103 is performed. Execute control.
[0059]
As a result of the determination in S107, when the inter-vehicle distance Lab between the preceding vehicle and the preceding vehicle is smaller than a preset threshold K1 (when Lab <K1), the process proceeds to S108, where the preceding vehicle speed Va and the preceding vehicle speed Vb are compared. Make a comparison.
[0060]
As a result of the comparison in S108, when the preceding vehicle speed Va is equal to or lower than the pre-preceding vehicle speed Vb (Va ≦ Vb), the process directly exits the routine, and the driving support control using the pre-preceding vehicle in S103 is executed.
[0061]
Conversely, if the preceding vehicle speed Va is higher than the pre-preceding vehicle speed Vb (Va> Vb), the process proceeds to S109, and if acceleration is to be performed by the driving support control in S103, the acceleration is suppressed (for example, the target Is reduced to 50%). That is, if the inter-vehicle distance between the preceding vehicle and the preceding vehicle is shorter than the threshold value K1 and the preceding vehicle speed Va is higher than the preceding vehicle speed Vb, the preceding vehicle may catch up with the preceding vehicle and apply a brake. This allows the vehicle to follow the vehicle.
[0062]
Thereafter, the process proceeds to S110, and it is determined whether or not the inter-vehicle distance Lab between the preceding vehicle and the preceding vehicle is equal to or greater than a preset threshold value K2 (<K1). Then, as a result of this determination, if the inter-vehicle distance Lab between the preceding vehicle and the preceding vehicle is equal to or greater than a preset threshold value K2 (Lab ≧ K2), the routine exits (only by suppressing acceleration). Conversely, if the inter-vehicle distance Lab between the preceding vehicle and the preceding vehicle is smaller than a preset threshold value K2 (Lab <K2), the process proceeds to S111, and a value obtained by subtracting the preceding vehicle speed Vb from the preceding vehicle speed Va (= It is determined whether Va−Vb) is equal to or higher than a preset speed value Vc1.
[0063]
If the result of the determination in S111 is that (Va-Vb) is smaller than the speed value Vc1 set in advance, the routine exits the routine (only by suppressing the acceleration). Conversely, if (Va-Vb) is equal to or greater than the preset speed value Vc1, that is, if the preceding vehicle is rapidly approaching the preceding vehicle, the process proceeds to S112, and A signal is output to the brake control device 14 to increase the brake oil pressure in advance to prepare for braking, and the routine exits as a state in which braking can be applied with good response. In the process of S112, the driver may be notified on the monitor 15 that the vehicle 1 is preparing for braking by blinking a lamp or the like. Although not particularly shown, the driver not only informs the driver on the monitor 15 but also turns on a lamp or a communication device to notify the vehicles and the infrastructure around the host vehicle 1 that the host vehicle 1 is preparing for braking. May be notified.
[0064]
As described above, according to the present embodiment, in the driving support control in the case where the preceding vehicle and the preceding vehicle are present, the inter-vehicle distance between the preceding vehicle and the preceding vehicle approaches, and further, the preceding vehicle becomes the preceding vehicle. In the case of a sudden approach, control is performed to increase the brake hydraulic pressure in advance and prepare for braking.For example, even when the preceding vehicle suddenly brakes due to the presence of a preceding vehicle, a brake control with a good response can be achieved. Done.
[0065]
Further, since the acceleration control and the deceleration control are not simply set according to the conditions, natural and comfortable driving assistance can be performed for the driver who drives while visually confirming the front.
[0066]
In the present embodiment, the stereo camera 3, the millimeter-wave radar transmitting / receiving unit 4, the distance measuring device 5, and the forward information recognition device 6 detect forward information, preceding vehicle information, and preceding vehicle information. However, the present invention is not limited to this. For example, the stereo camera 3 and the forward information recognition device 6 may be configured so that each information can be obtained only. It may be realized using a radar device of a wavelength (for example, an infrared laser).
[0067]
【The invention's effect】
As described above, according to the present invention, especially in a large-scale road without an infrastructure, it can be easily adopted, is excellent in versatility, and in a situation where there is no need to actually decelerate, it is necessary to prepare for deceleration. In some cases, the vehicle decelerates with a good response and the safety is extremely high, so that an excellent effect that a natural and comfortable driving support can be provided to the driver is provided.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a vehicle driving assistance device mounted on a vehicle.
FIG. 2 is a flowchart of a driving support control program.
FIG. 3 is a flowchart of a pre-preceding vehicle extraction routine.
FIG. 4 is a flowchart of a target inter-vehicle distance calculation routine;
[Explanation of symbols]
1 own vehicle
2 ACC system (vehicle driving support device)
3 stereo camera (forward information recognition means, preceding vehicle information detection means, pre-preceding vehicle information detection means)
4 transmission / reception unit (forward information recognition means, preceding vehicle information detection means, pre-preceding vehicle information detection means)
5. Distance measurement processing device (forward information recognition means, preceding vehicle information detection means, pre-preceding vehicle information detection means)
6. Forward information recognition device (forward information recognition means, preceding vehicle information detection means, pre-preceding vehicle information detection means)
7 control device (control means)
11 Constant speed switch
14. Automatic brake control device (brake means)
15 monitor (broadcast communication means)

Claims

On-board forward information recognition means for detecting and recognizing an environment in front of the vehicle;
Preceding vehicle information detecting means for detecting preceding vehicle information based on forward information from the forward information recognizing means;
A two-way vehicle information detecting means for detecting two-way vehicle information traveling further ahead of the preceding vehicle based on the forward information and the preceding vehicle information from the forward information recognizing means,
Control means for executing travel control based on the forward information, the preceding vehicle information, and the pre-preceding vehicle information, and performing at least braking preparation by braking means based on the preceding vehicle information and the preceding vehicle information. Driving support device for vehicles.

The preceding vehicle information detecting means is not the preceding vehicle detected by the preceding vehicle information detecting means, and is located farther than the detected preceding vehicle, and is most likely to exist in the own vehicle that has entered the traveling area of the own vehicle. The driving assistance device for a vehicle according to claim 1, wherein a three-dimensional object in front located at a close position is detected as the preceding vehicle.

The control means is configured to control when the inter-vehicle distance between the preceding vehicle and the pre-preceding vehicle is closer than a predetermined distance, and when the speed of the preceding vehicle is greater than the speed of the preceding vehicle beyond a predetermined speed. 3. The driving assistance device for a vehicle according to claim 1, wherein a preparation for braking by the braking means is performed.

4. The vehicle driving support device according to claim 1, wherein the control unit performs the preparation for braking by the brake unit by increasing a brake hydraulic pressure in advance. 5.

The control means performs at least a target inter-vehicle distance between the host vehicle and the preceding vehicle to perform travel control, and the control means determines a first target inter-vehicle distance when the preceding vehicle exists. If the preceding vehicle exists, a second target inter-vehicle distance is obtained. If only the preceding vehicle exists, the first target inter-vehicle distance is set as the target inter-vehicle distance. 5. The vehicle according to claim 1, wherein, if present, the target inter-vehicle distance is set according to the first target inter-vehicle distance and the second target inter-vehicle distance. 6. Driving support device for vehicles.

6. An information communication means for informing or communicating at least one of the inside and the outside of the vehicle that the control means is ready for braking by the brake means. The driving assistance device for a vehicle according to any one of the preceding claims.