JP3780684B2 - Inter-vehicle distance control device - Google Patents

Description

ただし、Ｇ１，Ｇ２，Ｇ３は制御ゲインである。
【００７６】
そして駆動力制御部１６が第１の実施の形態と同様に、目標駆動力Ｆｔに応じてスロットル開度ｓａ、ブレーキ液圧ｂａを演算する。
【００７７】
また車間距離制御部１５ａは、次の数１０式のように、車間距離制御によって発生する目標車速ｖｃを時間微分することによって減速度α１も算出しておく（ステップＳ１５ｂ）。
【００７８】
【数１０】

次に、第１の実施の形態と同様に、レーン幅検出部１９によってレーン幅ｌｗを検出し（ステップＳ１６）、センシング可能性判断部２０によって追従車間距離Ｌにおける車間距離検出部１１の検出幅ｗが現実のレーン幅ｌｗよりも小さいかどうか比較する（ステップＳ１７）。
【００７９】
追従車間距離における車間距離検出幅ｗが現実のレーン幅ｌｗよりも大きければ、先行車をセンシング可能と判断してステップＳ１９に移行し、第１の実施の形態と同様に、駆動力制御部１６の演算したスロットル開度ｓａとブレーキ液圧ｂａに一致するようにスロットル開度、ブレーキ液圧を制御して自車速を加減し、先行車に対して自車が目標車間距離を維持しながら追従するように制御する（ステップＳ１９，Ｓ２０）。
【００８０】
しかしながら、追従車間距離における車間距離検出部１１の検出幅ｗがレーン幅ｌｗよりも小さいために、センシング可能性判断部２０がステップＳ１７で先行車をセンシングできないと判断すれば、減速度緩和制御指令を減速度緩和解除部２１ａに出力する。
【００８１】
減速度緩和解除部２１ａは車間距離制御部１５ａからの減速度指令値α１から減速度指令値α２を、次の数１１式により演算する（ステップＳ１８ａ）。
【００８２】
［数１１］
減速度指令値α２
＝センシング不可能判断直前の数１０式による減速度α１
＋Ｄ１×（センシング不可能判断時の速度−車速検出値ｖａ）
ただし、Ｄ１は定数である。
【００８３】
車間距離制御部１５ａは与えられるこの調整済みの減速度力指令値α２に基づいて再度目標車速ｖc2を演算して車速制御部１５ｂに出力し、以降、通常制御の場合と同様に、車速制御部１５ｂでこの目標車速ｖc2に対する制駆動力Ｆt2を演算し、駆動力制御部１６によってスロットルアクチュエータ１７とブレーキアクチュエータ１８を制御して減速制御する（ステップＳ１９，Ｓ２０）。
【００８４】
このようにして、数１１式により減速度指令値α２を演算し、これに基づく新たな制動力指令値Ｆt2を演算して駆動力制御すれば、制御解除速度において数２式により演算した制動力Ｆt1（元のＦｔ）とスムーズに連続的につながり、徐々に減速度を弱めることができる。
【００８５】
なお、上記の第２の実施の形態では車速制御の解除時に、車間距離制御部１５ａが演算する減速度を徐々に緩和するようにしたが、これに代えて、次の数１２式により、減速度指令値α２を時間に応じて徐々に緩和する制御を採用することもできる。
【００８６】
［数１２］
減速度指令値α２
＝センシング不可能判断直前の数１０式による減速度α１
＋Ｄ２×センシング不可能判断時からの経過時間ｔ
ただし、Ｄ２は定数である。
【００８７】
この場合、減速度指令値α２から次の数１３式により目標車速ｖc2を再計算し、これに基づいて減速制御することになる。
【００８８】
［数１３］
目標車速ｖc2＝センシング不可能判断直前の数８式による目標車速ｖｃ
＋減速度指令値α２×経過時間ｔ
これらの第１及び第２の実施の形態によれば、センシング限界に応じて制御領域を設定し、自車が制御領域を超えても車速あるいは時間経過に応じて制動力又は減速度を徐々に緩和しながら制御を解除するので、
（１）センシング限界に応じて制御領域を設定することができて、センサ信号に応じた走行制御が確実に行え、
（２）センシング限界を超えた領域で急に減速制御を解除するのではなく、センシング限界を超えた領域でも減速制御を維持することができ、
（３）制御解除領域になったとき、解除領域になる直前のデータを用いることにより乗り心地の悪化を防ぐことができ、
（４）徐々に制御を停止させることができて、低速域で制御が解除されるのを完全に制御が解除される前に（制動力緩和又は減速度緩和解除中に）ドライバに知覚させることができる。
【００８９】
次に、本発明の第３の実施の形態の車間距離制御装置を、図８及び図９に基づいて説明する。第３の実施の形態の特徴は、図１に示した第１の実施の形態に対して、レーン幅検出部１９に代えて解除速度設定部２２を備え、センシング可能性判断部２０に代えて速度制御領域判断部２３を備えた点にあり、その他の構成要素は第１の実施の形態のものと共通である。
【００９０】
解除速度設定部２２は、あらかじめ設定される制御解除速度値ｖｄを保持している。この解除速度ｖｄは、次のようにして求められた値である。一般的な道路幅を用いてその値をＨとすると、車間距離検出部１１がそのセンシング角θにより道路幅以上の検出幅ｗとなる車間距離Ｌは、第１の実施の形態で説明したように、数５式より求めて、次の数１４式のＬ以上の場合となる。
【００９１】
［数１４］
Ｌ＝Ｈ／（２・ tan（θ／２））
そこで、この車間距離Ｌに制御する速度を、数１式より求めて解除速度ｖｄに設定する。
【００９２】
［数１５］
解除速度ｖｄ＝（Ｌ−Ｂ）／Ａ
ただし、Ａ，Ｂは数１式で用いた定数である。
【００９３】
速度制御領域判断部２３は、車速検出部１２による車速検出値ｖａと解除速度設定部２１からの解除速度ｖｄとを比較し、車速検出値ｖａが解除速度よりも大きければ車間距離制御を継続し、車速検出値ｖａが解除速度以下になれば制動力緩和制御指令を制動力緩和解除部２１に出力する。
【００９４】
次に、上記の第３の実施の形態の車間距離制御装置の動作を、図９のフローチャートを参照して説明する。通常の車間距離制御では、図２に示した第１の実施の形態の処理と同様に、車間距離検出部１１によって車間距離ｄａを検出し、相対速度演算部１３によって相対速度ｖｂを演算し、車速検出部１２によって自車速ｖａを検出し、さらに目標車間距離演算部１４によって目標車間距離ｄｂを演算して車間距離制御部１５に入力する（ステップＳ１１〜Ｓ１４）。
【００９５】
車間距離制御部１５は入力される相対速度ｖｂ、車間距離ｄａ、目標車間距離ｄｂから制駆動力Ｆｔを演算して駆動力制御部１６に与える（ステップＳ１５）。
【００９６】
そして速度制御解除判断部２３では、車速検出値ｖａと解除速度ｖｄとを比較し、車速検出値ｖａが解除速度よりも大きければ車間距離制御を継続し、車速検出値ｖａが解除速度以下になれば制動力緩和制御指令を制動力緩和解除部２１に出力する（ステップＳ１７ａ）。
【００９７】
ステップＳ１７ａで速度制御解除判断部２３が車間距離制御を継続すると判断した場合、第１の実施の形態と同じく制動力緩和解除部２１は車間距離制御部１５の出力する制駆動力Ｆｔに介入せず、駆動力制御部１６の演算したスロットル開度ｓａとブレーキ液圧ｂａをスロットルアクチュエータ１７、ブレーキアクチュエータ１８それぞれに与え、スロットルアクチュエータ１７及びブレーキアクチュエータ１８が与えられる指令値に一致するようにスロットル開度、ブレーキ液圧を作動させて自車速を加減し、先行車に対して自車が目標車間距離を維持しながら追従するように制御する（ステップＳ１９，Ｓ２０）。
【００９８】
他方、ステップＳ１７ａで速度制御解除判断部２３が制動力緩和解除と判断した場合には、制動力緩和解除部２１は第１の実施の形態と同様に、次の数１６式によって車速検出値ｖａから制動力指令値Ｆt2を演算し（ステップＳ１８）、車間距離制御部１５は与えられる制動力指令値Ｆt2を制駆動力Ｆｔとして駆動力制御部１６に出力し、制動力を制御させる（ステップＳ１９，Ｓ２０）。
【００９９】
［数１６］
制動力指令値Ｆt2
＝解除速度到達判断直前の数２式による制動力Ｆt1
＋Ｃ１×（解除速度到達判断時の速度ｖa1−車速検出値ｖa2）
ただし、Ｃ１は定数である。
【０１００】
こうして、第３の実施の形態によれば、自車速ｖａがあらかじめ設定されている解除速度ｖｄ以下になれば、上記の数１６式により制動力指令値Ｆt2を演算し、これを新たな制駆動力指令値Ｆｔとして駆動力制御することにより、制御解除速度ｖｄで数２式により演算した値Ｆt1（元のＦｔ）とスムーズに連続的につながり、車速に応じて徐々に制動力を弱めることができる。
【０１０１】
なお、上記の第３の実施の形態では、車間距離制御の解除時に車間距離制御部１５が演算する制動力Ｆｔを車速に応じて徐々に緩和するようにしたが、これに代えて、第１の実施の形態と同様に、次の数１７式により、制動力指令値Ｆｔを時間に応じて徐々に緩和する制御を採用することもできる。
【０１０２】
［数１７］
制動力指令値Ｆt2
＝解除速度到達判断直前の数２式による制動力Ｆt1
＋Ｃ２×解除速度到達判断時からの経過時間ｔ
ただし、Ｃ２は定数である。
【０１０３】
次に、本発明の第４の実施の形態の車間距離を、図１０及び図１１に基づいて説明する。第４の実施の形態の特徴は、第１の実施の形態に対する第２の実施の形態の場合と同様に、図８に示した第３の実施の形態に対して、車間距離制御部１５ａが入力される車間距離ｄａ、目標車間距離ｄｂ、自車速ｖａ、相対速度ｖｂにより目標車間距離ｄｂに現実の車間距離ｄａを一致させるために必要な自車の目標速度ｖｃと減速度αを演算し、車速制御部１５ｂがこの目標速度ｖｃに対して必要な制駆動力Ｆｔを演算して駆動力制御部１６に与え、この駆動力制御部１６が第１の実施の形態と同様にスロットル開度ｓａ、ブレーキ液圧ｂａを演算してスロットルアクチュエータ１７及びブレーキアクチュエータ１８を制御する構成であり、さらに、第３の実施の形態における制動力緩和解除部２１に代わる減速度緩和解除部２１ａが速度制御領域判断部２３の制御解除速度到達の判断結果を受けて、車間距離制御部１５ａの演算した減速度α１を調整し、車間距離制御部１５ａに返すようにした点にある。なお、この第４の実施の形態にあって、上記の要素以外は図８に示した第３の実施の形態と同じものを備え、同じ働きをする。
【０１０４】
この第４の実施の形態の車間距離制御装置では、図１１のフローチャートに示すように、第３の実施の形態と同様、車間距離検出部１１によって車間距離ｄａを検出し、相対速度演算部１３により相対速度ｖｂを演算し、車速検出部１２によって自車速ｖａを検出し、目標車間距離演算部１４によって目標車間距離ｄｂを演算する（ステップステップＳ１１〜Ｓ１４）。
【０１０５】
車間距離制御部１５ａは入力される相対速度ｖｂ、車間距離ｄａ、目標車間距離ｄｂから、第２の実施の形態のところで説明した数８式によって目標車速ｖｃを演算する（ステップＳ１５ａ）。車間距離制御部１５ａはまた、数１０式に基づき、車間距離制御によって発生する目標車速ｖｃを時間微分することによって減速度α１も算出する（ステップＳ１５ｂ）。
【０１０６】
車速制御部１５ｂは、与えられる目標車速ｖｃに自車速ｖａを一致させるための目標制駆動力Ｆｔを前述の数９式によって演算する。そして駆動力制御部１６が第３の実施の形態と同様に、目標駆動力Ｆｔに応じてスロットル開度ｓａ、ブレーキ液圧ｂａを演算する。
【０１０７】
次に、第３の実施の形態と同様に、速度制御解除判断部２３が車速検出値ｖａと解除速度ｖｄとを比較し、車速検出値ｖａが解除速度よりも大きければ車間距離制御を継続し、車速検出値ｖａが解除速度以下になれば減速度緩和制御指令を減速度緩和解除部２１ａに出力する（ステップＳ１７ａ）。
【０１０８】
ステップＳ１７ａで速度制御解除判断部２３が車間距離制御を継続すると判断した場合、減速度緩和解除部２１ａは車間距離制御部１５ａの出力する目標車速ｖｃに介入せず、車速制御部１５ｂの演算した制駆動力Ｆｔに対して駆動力制御部１６にスロットル開度ｓａとブレーキ液圧ｂａを演算させ、これらをスロットルアクチュエータ１７、ブレーキアクチュエータ１８それぞれに与え、スロットル開度、ブレーキ液圧を制御して自車速を加減し、先行車に対して自車が目標車間距離を維持しながら追従するように制御する（ステップＳ１９，Ｓ２０）。
【０１０９】
他方、ステップＳ１７ａで速度制御解除判断部２３が減速度緩和解除と判断した場合には、減速度緩和制御指令を減速度緩和解除部２１ａに出力し、減速度緩和解除部２１ａは車間距離制御部１５ａからの減速度指令値α１から減速度指令値α２を第２の実施の形態と同様に数１８式により演算する（ステップＳ１８ａ）。
【０１１０】
［数１８］
減速度指令値α２
＝解除速度到達判断直前の数１０式による減速度α１
＋Ｄ１×（解除速度到達判断時の速度−車速検出値ｖａ）
ただし、Ｄ１は定数である。
【０１１１】
車間距離制御部１５ａは与えられる調整済みの減速度力指令値α２に基づいて再度目標車速ｖc2を演算して車速制御部１５ｂに出力し（ステップＳ１８ｂ）、以降、通常制御の場合と同様に、車速制御部１５ｂでこの目標車速ｖc2に対する制駆動力Ｆt2を演算し、駆動力制御部１６によってスロットルアクチュエータ１７とブレーキアクチュエータ１８を制御して減速制御する（ステップＳ１９，Ｓ２０）。
【０１１２】
このようにして、数１８式により減速度指令値α２を演算し、これに基づく新たな制動力指令値Ｆt2を演算して駆動力制御すれば、制御解除速度において数２式により演算した制動力Ｆt1（元のＦｔ）とスムーズに連続的につながり、徐々に減速度を弱めることができる。
【０１１３】
なお、上記の第４の実施の形態では車速制御の解除時に、車間距離制御部１５ａが演算する減速度を徐々に緩和するようにしたが、第２の実施の形態の場合と同様に、次の数１９式により減速度指令値α２を時間に応じて徐々に緩和する制御を採用することもできる。
【０１１４】
［数１９］
減速度指令値α２
＝解除速度到達判断直前の数１０式による減速度α１
＋Ｄ２×解除速度到達判断時からの経過時間ｔ
ただし、Ｄ２は定数である。
【０１１５】
この場合、減速度指令値α２から次の数２０式により目標車速ｖc2を再計算し、これに基づいて減速制御することになる。
【０１１６】
［数２０］
目標車速ｖc2＝解除速度到達判断直前の数８式による目標車速ｖｃ
＋減速度指令値α２×経過時間ｔ
この第３及び第４の実施の形態の車間距離制御装置によれば、自車が制御領域を超えても車速あるいは時間に応じて制動力あるいは減速度を徐々に緩和しながら制御を解除するようにしたので、第１及び第２の実施の形態と同様に（１）〜（４）の効果を奏する。
【０１１７】
次に、本発明の第５の実施の形態の車間距離制御装置を、図１２及び図１３に基づいて説明する。第５の実施の形態の特徴は、図８に示した第３の実施の形態に対して、制動力緩和解除部２４に代えて制動力保持部２５を備えた点にあり、その他の構成要素は第３の実施の形態のものと共通である。
【０１１８】
制動力保持部２５は、速度制御領域判断部２３が制御領域判断に基づき、車速検出値ｖａが解除速度ｖｄ以下になって制動力保持指令を出力すると、この判断時に車間距離制御部１５が出力する制動力Ｆt1（＝Ｆｔ）を保持するように制動力保持値Ｆt2（＝Ｆt1）を駆動力制御部１６に出力する働きをする。
【０１１９】
次に、上記の第５の実施の形態の車間距離制御装置の動作を、図１３のフローチャートを参照して説明する。通常の車間距離制御では、図２に示した第１の実施の形態の処理と同様に、車間距離検出部１１によって車間距離ｄａを検出し、相対速度演算部１３によって相対速度ｖｂを演算し、車速検出部１２によって自車速ｖａを検出し、さらに目標車間距離演算部１４によって目標車間距離ｄｂを演算して車間距離制御部１５に出力し（ステップＳ１１〜Ｓ１４）、車間距離制御部１５は制駆動力Ｆｔを演算して駆動力制御部１６に与える（ステップＳ１５）。
【０１２０】
そして速度制御解除判断部２３では第３の実施の形態と同様に、車速検出値ｖａと解除速度ｖｄとを比較し、車速検出値ｖａが解除速度よりも大きければ車間距離制御を継続し、車速検出値ｖａが解除速度以下になれば制動力保持制御指令を制動力保持部２５に出力する（ステップＳ１７ａ）。
【０１２１】
ステップＳ１７ａで速度制御解除判断部２３が車間距離制御を継続すると判断した場合、制動力保持部２５は車間距離制御部１５の出力する制駆動力Ｆｔに介入せず、駆動力制御部１６の演算したスロットル開度ｓａとブレーキ液圧ｂａをスロットルアクチュエータ１７、ブレーキアクチュエータ１８それぞれに与え、スロットルアクチュエータ１７及びブレーキアクチュエータ１８が与えられる指令値に一致するようにスロットル開度、ブレーキ液圧を作動させて自車速を加減し、先行車に対して自車が目標車間距離を維持しながら追従するように制御する（ステップＳ１９，Ｓ２０）。
【０１２２】
他方、ステップＳ１７ａで速度制御解除判断部２３が制動力保持と判断した場合には、制動力保持部２５は、車間距離制御部１５から得た解除速度到達判断直前の制動力指令値Ｆt1を保持し（ステップＳ１８ｃ）、これを制動力指令値Ｆｔとして駆動力制御部１６に出力し、制動力を制御させる（ステップＳ１９，Ｓ２０）。
【０１２３】
こうして、第５の実施の形態によれば、自車速ｖａがあらかじめ設定されている解除速度ｖｄ以下になれば、解除速度到達判断直前の制動力指令値Ｆt1を保持し、これを制駆動力指令値Ｆｔとして駆動力制御することにより、自車が制御領域を超えても直前の車速ｖａに応じた制動力を保持し、制動力が急に解除されることがないようにするのである。
【０１２４】
次に、本発明の第６の実施の形態の車間距離を、図１４及び図１５に基づいて説明する。第６の実施の形態の特徴は、第３の実施の形態に対する第４の実施の形態の場合と同様に、図１２に示した第５の実施の形態に対して、車間距離制御部１５ａが入力される車間距離ｄａ、目標車間距離ｄｂ、自車速ｖａ、相対速度ｖｂにより目標車間距離ｄｂに現実の車間距離ｄａを一致させるために必要な自車の目標速度ｖｃと減速度αを演算し、車速制御部１５ｂがこの目標速度ｖｃに対して必要な制駆動力Ｆｔを演算して駆動力制御部１６に与え、この駆動力制御部１６が第１の実施の形態と同様にスロットル開度ｓａ、ブレーキ液圧ｂａを演算してスロットルアクチュエータ１７及びブレーキアクチュエータ１８を制御する構成であり、さらに、第５の実施の形態における制動力保持部２５に代わる減速度保持部２５ａが速度制御領域判断部２３の制御解除速度到達の判断結果を受けて、制御解除直前に車間距離制御部１５ａの演算した減速度α１を保持するようにした点にある。なお、この第６の実施の形態にあって、上記の要素以外は図１２に示した第５の実施の形態と同じものを備え、同じ働きをする。
【０１２５】
この第６の実施の形態の車間距離制御装置では、図１５のフローチャートに示すように、図１１のフローチャートに示した第４の実施の形態と同様、車間距離検出部１１によって車間距離ｄａを検出し、相対速度演算部１３により相対速度ｖｂを演算し、車速検出部１２によって自車速ｖａを検出し、目標車間距離演算部１４によって目標車間距離ｄｂを演算する（ステップステップＳ１１〜Ｓ１４）。
【０１２６】
そして車間距離制御部１５ａは前述の数８式によって目標車速ｖｃを演算する（ステップＳ１５ａ）。また車間距離制御部１５ａは前述の数１０式により、車間距離制御によって発生する目標車速ｖｃを時間微分することによって減速度α１も算出する（ステップＳ１５ｂ）。
【０１２７】
次に、速度制御解除判断部２３が車速検出値ｖａと解除速度ｖｄとを比較し、車速検出値ｖａが解除速度よりも大きければ車間距離制御を継続し、車速検出値ｖａが解除速度以下になれば減速度保持制御指令を減速度保持部２５ａに出力する（ステップＳ１７ａ）。
【０１２８】
ステップＳ１７ａで速度制御解除判断部２３が車間距離制御を継続すると判断した場合、減速度保持部２５ａは車間距離制御部１５ａの出力する目標車速ｖｃに介入せず、第４の実施の形態と同様、車速制御部１５ｂで制駆動力Ｆｔを演算させ、これに対して駆動力制御部１６の演算したスロットル開度ｓａとブレーキ液圧ｂａをスロットルアクチュエータ１７、ブレーキアクチュエータ１８それぞれに与え、スロットル開度、ブレーキ液圧を制御して自車速を加減し、先行車に対して自車が目標車間距離を維持しながら追従するように制御する（ステップＳ１９，Ｓ２０）。
【０１２９】
他方、ステップＳ１７ａで速度制御解除判断部２３が減速度保持と判断した場合には、減速度保持制御指令を減速度保持部２５ａに出力し、減速度保持部２５ａは車間距離制御部１５ａからの解除速度到達直前の減速度指令値α１を保持し、これを車間距離制御部１５ａにα２（＝α１）として返す（ステップＳ１８ｄ）。
【０１３０】
第２の実施の形態と同様に、車間距離制御部１５ａは減速度保持部２５ａから与えられる減速度力指令値α２（＝α１）に基づいて目標車速ｖc2を演算して車速制御部１５ｂに出力し（ステップＳ１８ｂ）、以降、通常制御の場合と同様に、車速制御部１５ｂでこの目標車速ｖc2に対する制駆動力Ｆt2を演算し、駆動力制御部１６によってスロットルアクチュエータ１７とブレーキアクチュエータ１８を制御して減速制御する（ステップＳ１９，Ｓ２０）。
【０１３１】
このようにして、第６の実施の形態では車速制御の解除時に、車間距離制御部１５ａが演算する減速度を保持し、これに基づいて駆動力制御することにより、自車が制御領域を超えても直前の車速ｖａに応じた減速度を保持し、減速度が急に解除されることがないようにするのである。
【０１３２】
この第５及び第６の実施の形態の車間距離制御装置によれば、自車が制御領域を超えても制動力あるいは減速度を保持するようにしたので、
（１）センシング限界を超えた領域においても、減速度制御を維持することができ、
（２）制御解除領域になったとき、解除領域になる直前のデータを用いることによって乗り心地の悪化を防ぐことができる。
【０１３３】
次に、本発明の第７の実施の形態の車間距離制御装置を、図１６〜図１８に基づいて説明する。第７の実施の形態の特徴は、図８に示した第３の実施の形態における制動力緩和解除部２１に代えて、制動力調整部２６を備えた点にあり、この制動力調整部２６は、自車が制御領域を超えると制動力を後述する方法で調整する働きをするものである。なお、その他の構成要素については第３の実施の形態と共通である。
【０１３４】
次に、この第７の実施の形態の動作を図１７のフローチャートを参照して説明する。通常の車間距離制御では、図８に示した第３の実施の形態の処理と同様に、車間距離ｄａを検出し、相対速度ｖｂを演算し、自車速ｖａを検出し、さらに目標車間距離ｄｂを演算して車間距離制御部１５に与え（ステップＳ１１〜Ｓ１４）、車間距離制御部１５は制駆動力Ｆｔを演算して駆動力制御部１６に与える（ステップＳ１５）。
【０１３５】
そして速度制御解除判断部２３では、車速検出値ｖａと解除速度ｖｄとを比較し、車速検出値ｖａが解除速度よりも大きければ車間距離制御を継続し、車速検出値ｖａが解除速度以下になれば制動力調整制御指令を制動力調整部２６に出力する（ステップＳ１７ａ）。
【０１３６】
ステップＳ１７ａで速度制御解除判断部２３が車間距離制御を継続すると判断した場合、第３の実施の形態と同じく制動力調整部２６は車間距離制御部１５の出力する制駆動力Ｆｔに介入せず、駆動力制御部１６の演算したスロットル開度ｓａとブレーキ液圧ｂａに一致するようにスロットルアクチュエータ１７、ブレーキアクチュエータ１８それぞれを作動させて自車速を加減し、先行車に対して自車が目標車間距離ｄｂを維持しながら追従するように制御する（ステップＳ１９，Ｓ２０）。
【０１３７】
他方、ステップＳ１７ａで速度制御解除判断部２３が制動力調整制御と判断した場合には、制動力調整部２６は制御領域を超える直前の車間距離ｄａと相対速度ｖｂとに応じて、次の数２１式に基づいて制動力Ｆt1（＝Ｆｔ）を緩和、保持、あるいは増強する調整をし、その調整結果として得られるＦt2を駆動力制御部１６に与える（ステップＳ１８ｅ）。
【０１３８】
［数２１］
（ｉ）相対速度ｖｂ≦所定値１（先行車に接近する）の場合
（ i-1）車間距離ｖａ≦所定値３
下記の数２２式の演算により、制動力を増強制御する。
【０１３９】
（ i-2）車間距離ｖａ＞所定値３
解除速度到達直前の制動力Ｆt1を保持する。
【０１４０】
（ii）相対速度ｖｂ≧所定値２（先行車から離間する）の場合
車間距離ｄａによらず、数１６式の演算により、制動力を緩和制御する。
【０１４１】
（ iii）所定値２＞相対速度ｖｂ＞所定値１（先行車に巡航）の場合
（ iii-1）車間距離ｄａ≦所定値４
解除速度到達直前の制動力Ｆt1を保持する。
【０１４２】
（ iii-2）車間距離ｄａ＞所定値４
数１６式の演算により、制動力を緩和制御する。
【０１４３】
図１８はこれらの緩和、保持、増強した場合それぞれの減速度パターンを示している。そして制動力を増強する場合、次の数２２式によって制動力を演算する。
【０１４４】
［数２２］
制動力指令値Ｆt2
＝解除速度到達直前の数２式による制動力
−Ｃ３×（解除速度到達した時の速度ｖa1−車速検出値ｖa2）
ただし、Ｃ３は定数である。
【０１４５】
こうして、ステップＳ１８ｅで制動力調整部２６が演算を行って制動力指令値Ｆt2を決定すれば、車間距離制御部１５は与えられる制動力指令値Ｆt2を制駆動力Ｆｔとして駆動力制御部１６に出力し、制動力を制御させる（ステップＳ１９，Ｓ２０）。
【０１４６】
このようにして第７の実施の形態によれば、数２２式によって制動力指令値Ｆt2を演算することにより、制御解除速度において数２式で演算した値とスムーズに連続的につながり、徐々に制動力を強めることができる。
【０１４７】
なお、この第７の実施の形態においても、第３の実施の形態の場合と同様に、制動力指令値Ｆt2を増強する場合に、次の数２３式に示すように時間に応じた値を用いることもできる。
【０１４８】
［数２３］
制動力指令値Ｆt2
＝解除速度到達直前の数２式による制動力
−Ｃ４×解除速度到達した時からの経過時間ｔ
ただし、Ｃ４は定数である。
【０１４９】
次に、本発明の第８の実施の形態の車間距離制御装置を図１９及び図２０に基づいて説明する。図８に示した第３の実施の形態に対する図１０に示した第４の実施の形態の場合と同様に、第８の実施の形態は、図１６に示した第７の実施の形態における制動力調整部２６に代えて、減速度調整部２６ａを設けた点を特徴とする。この減速度調整部２６ａは、自車が制御領域を超えると減速度を後述する方法で調整する働きをする。
【０１５０】
次に、この第８の実施の形態の動作を図２０のフローチャートを参照して説明する。通常の車間距離制御では、図１１に示した第４の実施の形態の処理と同様に、車間距離検出部１１によって車間距離ｄａを検出し、相対速度演算部１３により相対速度ｖｂを演算し、車速検出部１２によって自車速ｖａを検出し、目標車間距離演算部１４によって目標車間距離ｄｂを演算し（ステップステップＳ１１〜Ｓ１４）、車間距離制御部１５ａは入力される相対速度ｖｂ、車間距離ｄａ、目標車間距離ｄｂから目標車速ｖｃを演算する（ステップＳ１５ａ）。車間距離制御部１５ａはまた、車間距離制御によって発生する目標車速ｖｃを時間微分することによって減速度α１も算出する（ステップＳ１５ｂ）。
【０１５１】
車速制御部１５ｂは、与えられる目標車速ｖｃに自車速ｖａを一致させるための目標制駆動力Ｆｔを前述の数９式によって演算する。そして駆動力制御部１６が第３の実施の形態と同様に、目標駆動力Ｆｔに応じてスロットル開度ｓａ、ブレーキ液圧ｂａを演算する。
【０１５２】
次に、速度制御解除判断部２３が車速検出値ｖａと解除速度ｖｄとを比較し、車速検出値ｖａが解除速度よりも大きければ車間距離制御を継続し、車速検出値ｖａが解除速度以下になれば減速度調整制御指令を減速度調整部２６ａに出力する（ステップＳ１７ａ）。
【０１５３】
ステップＳ１７ａで速度制御解除判断部２３が車間距離制御を継続すると判断した場合、減速度調整部２６ａは車間距離制御部１５ａの出力する目標車速ｖｃに介入せず、車速制御部１５ｂの演算した制駆動力Ｆｔに対して駆動力制御部１６にスロットル開度ｓａとブレーキ液圧ｂａを演算させ、これらをスロットルアクチュエータ１７、ブレーキアクチュエータ１８それぞれに与え、スロットル開度、ブレーキ液圧を制御して自車速を加減し、先行車に対して自車が目標車間距離を維持しながら追従するように制御する（ステップＳ１９，Ｓ２０）。
【０１５４】
他方、ステップＳ１７ａで速度制御解除判断部２３が制御領域を超えたと判断した場合には、減速度調整制御指令を減速度調整部２６ａに出力し、減速度調整部２６ａは車間距離制御部１５ａからの減速度指令値α１に対して、解除速度到達直前の車間距離ｄa1と相対速度ｖb1とに応じて、次の数２４式に基づいて減速度指令値α１を増強、保持若しくは緩和する演算を行い、その調整結果を減速度指令α２として車間距離制御部１５ａに出力する（ステップＳ１８ｆ）。
【０１５５】
［数２４］
（ｉ）相対速度ｖｂ≦所定値１（先行車に接近する）の場合
（ i-1）車間距離ｖａ≦所定値３
下記の数２５式の演算により、減速度を増強制御する。
【０１５６】
（ i-2）車間距離ｖａ＞所定値３
解除速度到達直前の減速度α１を保持する。
【０１５７】
（ii）相対速度ｖｂ≧所定値２（先行車から離間する）の場合
車間距離ｄａによらず、数１８式の演算により、減速度を緩和制御する。
【０１５８】
（ iii）所定値２＞相対速度ｖｂ＞所定値１（先行車に巡航）の場合
（ iii-1）車間距離ｄａ≦所定値４
解除速度到達直前の減速度α１を保持する。
【０１５９】
（ iii-2）車間距離ｄａ＞所定値４
数１８式の演算により、減速度を緩和制御する。
【０１６０】
減速度を増強する場合には、次の数２５式により減速度α２を求めたものを用いる。
【０１６１】
［数２５］
減速度指令値α２
＝解除速度到達判断直前の数１０式による減速度α１
−Ｄ３×（解除速度到達判断時の速度−車速検出値ｖａ）
ただし、Ｄ３は定数である。
【０１６２】
車間距離制御部１５ａは与えられる調整済みの減速度力指令値α２に基づいて再度目標車速ｖc2を演算して車速制御部１５ｂに出力し（ステップＳ１８ｂ）、以降、通常制御の場合と同様に、車速制御部１５ｂでこの目標車速ｖc2に対する制駆動力Ｆt2を演算し、駆動力制御部１６によってスロットルアクチュエータ１７とブレーキアクチュエータ１８を制御して減速制御する（ステップＳ１９，Ｓ２０）。
【０１６３】
このようにして第８の実施の形態によれば、数２４式によって減速度指令値α２を演算することにより、制御解除速度において数１０式で演算した値とスムーズに連続的につながり、徐々に減速度を強めることができる。
【０１６４】
なお、この第８の実施の形態においても、第４の実施の形態の場合と同様に、減速度指令値α２を増強する場合に、次の数２６式に示すように時間に応じた値を用いることもできる。
【０１６５】
［数２６］
減速度指令値α２
＝解除速度到達直前の数１０式による減速度
−Ｄ４×解除速度到達した時からの経過時間ｔ
ただし、Ｄ４は定数である。
【０１６６】
このようにして第７及び第８の実施の形態によれば、自車が制御領域を超えても、制御領域を超える直前の車間距離検出値と相対速度に応じて、車速あるいは時間に応じて制動力あるいは減速度を調整するので、第５及び第６の実施の形態の効果に加えて、制御領域を超えたときの先行車との相対関係に応じて適切に制動力あるいは減速度を調整することができる効果を奏する。
【０１６７】
次に、本発明の第９の実施の形態の車間距離制御装置を図２１〜図２３に基づいて説明する。第９の実施の形態の特徴は、図１６に示した第７の実施の形態に対して制動力調整部２６と共に、警報部２７を追加的に備えた点にある。この警報部２７は速度制御領域判断部２３から速度制御領域を超えたという判断出力を受けたときに、スピーカによる音又はＬＥＤ表示によりドライバに速度制御領域を超えたことを知らせるためのものである。なお、その他の構成要素はすべて、図１６に示した第７の実施の形態と共通であり、同一の働きをする。
【０１６８】
この第９の実施の形態の場合、図１６に示した第７の実施の形態と同様に動作するが、図２２のフローチャートに示すように、第７の実施の形態の動作を示す図１７のフローチャートに対して、制動力調整部２６によるステップＳ１８ｅの制動力指令値出力と共に、ステップＳ１８ｇにおける警報部２７による警報出力が追加されている。つまり、ステップＳ１７ａにおいて速度制御領域判断部２３が速度制御領域を超えた判断した場合、制動力調整部２６は制御領域を超える直前の車間距離ｄａと相対速度ｖｂとに応じて、車速あるいは時間に応じて制動力Ｆt1（＝Ｆｔ）を緩和、保持、あるいは増強する調整をし、その調整結果として得られるＦt2を駆動力制御部１６に与え（ステップＳ１８ｅ）、これと共に警報部２７が制御領域を超えたことを知らせる警報音又は表示出力によってドライバに知らせる（ステップＳ１８ｇ）。そしてスロットル開度、ブレーキ液圧を制御して制動力を調整する（ステップＳ１９，Ｓ２９）。
【０１６９】
これによって、第９の実施の形態の場合、自車速度が速度制御領域を超えても、制御領域を超える直前の車間距離検出値と相対速度に応じて、車速あるいは時間に応じて制動力を調整し、かつドライバに警報によって知らせることができ、第７の実施の形態の効果に加えて、低速域で制動力調整に移行する際にドライバにそのことを知らせることによって早めに車間距離制御を解除させることができるようになる。
【０１７０】
なお、第９の実施の形態における警報部２７には、警報音又は警報表示手段に代えて、あるいはこれらと共に、制動力を急に変化させて軽いショックを発生させ、ドライバに感知させる手段を採用することもできる。すなわち、図２３（ａ），（ｂ）に示すように、自車速ｖａが解除速度になると、車間距離制御部１５が出力する制動力指令値Ｆｔを０にしたり、元に戻したりする動作を一時的に繰返し、これに応動するブレーキ液圧ｂａ（同図（ｃ）参照）を０と元の値との間で何回か変動させ、自動車に軽いショックを起こさせてドライバに制御領域を超えたために車間距離制御を解除することを感知させるのである。
【０１７１】
また上記の第９の実施の形態では、図１６に示した第７の実施の形態に対して警報部２７を追加的に設けたが、これに代えて、図１８に示した第８の実施の形態に対して警報部２７を速度調整部２６ａと共に追加的に設ける構成にすることもできる。この場合にも、警報部２７としては、上記の第９の実施の形態と同様に警報音又は警報表示の手段を採用し、あるいは減速度を一時的に変動させる動作を行わせる手段を採用する。この場合の動作は、図２０に示した第８の実施の形態のフローチャートに対して、ステップＳ１８ｆの次に警報出力のステップを追加することになる。
【０１７２】
上記の第９の実施の形態によれば、自車速度が速度制御領域を超えても、制御領域を超える直前の車間距離検出値と相対速度に応じて、車速あるいは時間に応じて制動力あるいは減速度を調整し、かつドライバに警報によって知らせることができ、第７及び第８の実施の形態の効果に加えて、低速域で制動力調整あるいは減速度調整に移行する際にドライバにそのことを知らせることによって早めに車間距離制御を解除させることができる効果を奏する。
【０１７３】
また、この第９の実施の形態で採用された警報部２７は、図１における制動力緩和解除部２１と共に、図６に示した減速度緩和解除部２１ａと共に、図８における制動力緩和解除部２１と共に、図１０における減速度緩和解除部２１ａと共に、図１２における制動力保持部２５と共に、あるいは図１４における減速度保持部２４と共に設けることもでき、これによって車間距離制御を解除する際にドライバに早めにそれを認識させることができるようになる。
【０１７４】
次に、本発明の第１０の実施の形態の車間距離制御装置を図２４及び図２５に基づいて説明する。第１０の実施の形態の特徴は、図１６に示した第７の実施の形態に対して制動力調整部２６を省略し、代わりに警報部２７を備えた点にある。この警報部２７は第９の実施の形態と同様に、速度制御領域判断部２３から速度制御領域を超えたという判断出力を受けたときに、スピーカによる音又はＬＥＤ表示により、あるいは図２３に示した動作によってドライバに速度制御領域を超えたことを知らせるためのものである。なお、その他の構成要素はすべて、図１６に示した第７の実施の形態と共通であり、同一の働きをする。
【０１７５】
この第１０の実施の形態の場合、通常の車間距離制御では、図８に示した第３の実施の形態の処理と同様に、車間距離ｄａを検出し、相対速度ｖｂを演算し、自車速ｖａを検出し、さらに目標車間距離ｄｂを演算して車間距離制御部１５に与え（ステップＳ１１〜Ｓ１４）、車間距離制御部１５は制駆動力Ｆｔを演算して駆動力制御部１６に与える（ステップＳ１５）。
【０１７６】
そして速度制御解除判断部２３では、車速検出値ｖａと解除速度ｖｄとを比較し、車速検出値ｖａが解除速度よりも大きければ車間距離制御を継続し、車速検出値ｖａが解除速度以下になれば制御解除指令を車間距離制御部１５と警報部２７に出力する（ステップＳ１７ａ）。
【０１７７】
ステップＳ１７ａで速度制御解除判断部２３が車間距離制御を継続すると判断した場合、第３の実施の形態と同じく制動力調整部２６は車間距離制御部１５の出力する制駆動力Ｆｔに介入せず、駆動力制御部１６の演算したスロットル開度ｓａとブレーキ液圧ｂａに一致するようにスロットルアクチュエータ１７、ブレーキアクチュエータ１８それぞれを作動させて自車速を加減し、先行車に対して自車が目標車間距離ｄｂを維持しながら追従するように制御する（ステップＳ１９，Ｓ２０）。
【０１７８】
他方、ステップＳ１７ａで速度制御解除判断部２３が制御解除と判断した場合には、車間距離制御部１５は車間距離制御を中止するが、これと共に、制御解除指令を受けた警報部２７が警報を出力してドライバに知らせる（ステップＳ１７ｂ，Ｓ１７ｃ）。
【０１７９】
このようにして第１０の実施の形態によれば、自車速度が速度制御領域を超えた場合にドライバに警報音、表示、あるいは軽いショック発生によって知らせることができるようになる。
【０１８０】
なお、この第１０の実施の形態と同様に、図１９に示した第８の実施の形態における減速度調整部２６ａを省略し、代わりに警報部２７のみを設ける構成も可能であり、これによって上記の第１０の実施の形態と同様の効果を奏する。
【０１８１】
次に、本発明の第１１の実施の形態の車間距離制御装置を図２６及び図２７に基づいて説明する。第１１の実施の形態の車間距離制御装置は、図１に示した第１の実施の形態と同様の車間距離検出部１１、車速検出部１２、駆動力制御部１６、スロットルアクチュエータ１７及びブレーキアクチュエータ１８を備えている。
【０１８２】
この実施の形態の車間距離制御装置はさらに本発明の特徴として、車間距離ｄａと相対速度ｖｂに応じて、実車間距離を目標車間距離に制御するために必要な制駆動力Ｆｔを演算する車間距離制御部１５と、相対速度演算部１３からの相対速度ｖｂと車速検出部１２からの自車速ｖａとから先行車の速度ｖｅを演算する先行車速度演算部３０と、先行車速度ｖｅとあらかじめ設定されている自車の制御解除速度ｖｄとを比較して自車が解除速度ｖｄをオーバーするかどうか否かを予測する制御領域オーバ予測部３１と、制御領域オーバ予測結果により警報音又は警報表示を出力する警報部３２とを備えている。
【０１８３】
次に、上記の第１１の実施の形態の動作を、図２７のフローチャートを参照して説明する。車間距離検出部１１によって先行車との車間距離ｄａを検出し、相対速度演算部１３によって相対速度ｖｂを演算し、車速検出部１２によって自車速ｖａを検出し、これらの車速ｄａ、車速ｖａ、相対速度ｖｂを車間距離制御部１５に入力する（ステップＳ２１〜Ｓ２３）。
【０１８４】
そして自車速ｖａに対して適切な車間距離、つまり目標車間距離ｄｂを数１式によって演算し、さらに相対速度ｖｂ、車間距離ｄａ、目標車間距離ｄｂから数２式によって制駆動力Ｆｔを演算して駆動力制御部１６に与える。駆動力制御部１６は第１の実施の形態と同様に、与えられる制駆動力Ｆｔに応じて、スロットル開度ｓａ、ブレーキ液圧ｂａを図３及び図４の制御特性に基づいて演算して求め（ステップＳ２４）、これらのスロットル開度ｓａとブレーキ液圧ｂａをスロットルアクチュエータ１７、ブレーキアクチュエータ１８それぞれに与え、スロットルアクチュエータ１７及びブレーキアクチュエータ１８が与えられる指令値に一致するようにスロットル開度、ブレーキ液圧を作動させる（ステップＳ２５）。
【０１８５】
先行車速度演算部３０は次の数２７式によって先行車速度ｖｅを演算して制御領域オーバ予測部３１に入力する（ステップＳ２６）。
【０１８６】
［数２７］
先行車速度ｖｅ＝自車速ｖａ＋相対速度ｖｂ
制御領域オーバ予測部３１は先行車速度ｖｅをあらかじめ設定されている制御解除速度ｖｄと比較する（ステップＳ２７）。
【０１８７】
このステップＳ２７の判断で、先行車速度ｖｅの方が大きければそれに追従する自車速ｖａも制御解除速度ｖｄよりも大きくなるはずであるので制御解除せず、以降も引き続き車間距離制御を継続する。反対に、先行車速度ｖｅが制御解除速度ｖｄ以下であれば、これに追従する自車速ｖａもすぐに制御解除速度ｖｄ以下に低下することが予測されるので、制御領域オーバ予測判断を警報部３２に入力し、警報部３２に警報を出力させる（ステップＳ２８）。
【０１８８】
これによって、第１１の実施の形態によれば、先行車速度ｖｅが速度制御領域ｖｄを超えたとき、自車も速度制御領域を超える可能性があるとして警報するので、
（１）従来例のように減速制御中は制御を解除しない構成とした場合、低速域では車間距離に基づいて自動減速制御するのが難しいが、ドライバに早めに警報して車間距離制御を中止させることができ、
（２）追従車間距離を超えた場合に制御を解除する構成とした場合、減速中に制御を自動的に解除すると先行車に接近しすぎる可能性があるが、ドライバに警報して注意を促すことによって早めに接近回避の操作をさせることができ、
（３）上記第１〜第８の実施の形態のように制御領域を超えると徐々に制御を解除する構成とした場合にも、ドライバに警報して早めに車間距離制御を中止させることができる。
【０１８９】
なお、図２６に示した第１１の実施の形態では車間距離制御部１５で制駆動力Ｆｔを演算し、駆動力制御部１６でこの制駆動力Ｆｔに対応するスロットル開度ｓａ、ブレーキ液圧ｂａを演算してスロットル開度、ブレーキ液圧を加減する車間距離制御装置について説明したが、第２、第４、第６の実施の形態のように車間距離制御部１５ａによって目標車速ｖｃを演算し、これに対して車速制御部１５ｂで制駆動力Ｆｔを演算して駆動力制御部１６に入力する回路構成に対しても、第１１の実施の形態と同様に、先行車速度演算部３０、制御領域オーバ予測部３１及び警報部３２を設けることによって、同様の作用効果を有する車間距離制御装置を構成することができる。
【０１９０】
次に、本発明の第１２の実施の形態を図２８〜図３０に基づいて説明する。この第１２の実施の形態の車間距離制御装置は、第１１の実施の形態と同様の車間距離検出部１１、車速検出部１２、車間距離制御部１５、駆動力制御部１６、スロットルアクチュエータ１７及びブレーキアクチュエータ１８を備え、さらに先行車速度演算部３０を備えている。
【０１９１】
この実施の形態の車間距離制御装置はさらに本発明の特徴として、駆動力制御部１６から出力されるブレーキ液圧ｂａに応じた減速度を検出する減速度検出部３４、制御解除までのブレーキと制御解除後のエンジンブレーキによる減速とで先行車に接近しすぎないかどか予測する先行車への接近予測部３５及びこの先行車への接近予測部３５の判断結果に基づいて警報を出力する警報部３６を備えている。
【０１９２】
次に、上記構成の第１２の実施の形態の動作を、図２９のフローチャートを参照して説明する。第１１の実施の形態と同様に、車間距離検出部１１によって先行車との車間距離ｄａを検出し、相対速度演算部１３によって相対速度ｖｂを演算し、車速検出部１２によって自車速ｖａを検出し、これらの車速ｄａ、車速ｖａ、相対速度ｖｂを車間距離制御部１５に入力する（ステップＳ３１〜Ｓ３３）。車間距離制御部１５は制駆動力Ｆｔを演算して駆動力制御部１６に与え、駆動力制御部１６は与えられる制駆動力Ｆｔに応じて、スロットル開度ｓａ、ブレーキ液圧ｂａを演算して求め（ステップＳ３４）、スロットルアクチュエータ１７、ブレーキアクチュエータ１８は与えられる指令値に一致するようにスロットル開度、ブレーキ液圧を作動させる（ステップＳ３５）。
【０１９３】
先行車速度演算部３０は第１１の実施の形態と同様、前述の数２７式によって先行車速度ｖｅを演算して先行車への接近予測部３５に入力する（ステップＳ３６）。また減速度検出部３４は駆動力制御部１６の出力するブレーキ液圧指令値ｂａを入力し、ブレーキ液圧指令値ｂａに応じた減速度β１を、次の数２８式から求めて先行車への接近予測部３５に入力する（ステップＳ３７）。
【０１９４】
［数２８］
ブレーキ減速度β１＝Ｅ１×ブレーキ液圧ｂａ＋Ｅ２
ただし、Ｅ１，Ｅ２は定数であり、図３０に示すような実験値を直線近似して求める値である。なお、自車の減速度β１の演算は上記の方法によらず、自車速ｖａを時間微分し、あるいは時間差分によって算出することも可能であり、特に限定されることはない。
【０１９５】
先行車への接近予測部３５は制御解除後のエンジンブレーキによる減速度β２を選定し（ステップＳ３８）、続いて、先行車速度演算部３０からの先行車速度ｖｅと、減速度検出部３４からの制御解除までのブレーキ減速度β１と、この制御解除後のエンジンブレーキによる減速度β２と、さらにあらかじめ設定されている解除速度ｖｄとに基づき、次の数２９式に接近距離を演算する（ステップＳ３９）。
【０１９６】
［数２９］
接近距離ｄｃ＝車間距離検出値ｄａ
−（自車速ｖａ−解除速度ｖｄ）²／（２×フ゛レーキ減速度β１）
−（解除速度ｖｄ−先行車速度ｖｅ）²／（２×エンシ゛ンフ゛レーキ減速度β２）
そして得られた接近距離ｄｃを所定値と比較し、接近距離ｄｃが所定値よりも小さくなっていれば、警報部３６によって先行車への接近警報を出力してドライバに知らせる（ステップＳ４０，Ｓ４１）。
【０１９７】
これによって、第１２の実施の形態によれば、制御解除までのブレーキと制御解除後のエンジンブレーキによる減速で先行車に接近しすぎないかどうか予測判断し、接近しすぎるようであれば警報を出力することにより、第１１の実施の形態と同様に（１）〜（３）の効果を奏する。
【０１９８】
なお、図２８に示した第１２の実施の形態では、車間距離制御部１５で制駆動力Ｆｔを演算し、駆動力制御部１６でこの制駆動力Ｆｔに対応するスロットル開度ｓａ、ブレーキ液圧ｂａを演算してスロットル開度、ブレーキ液圧を加減する車間距離制御装置について説明したが、第２、第４、第６の実施の形態のように車間距離制御部１５ａによって目標車速ｖｃを演算し、これに対して車速制御部１５ｂで制駆動力Ｆｔを演算して駆動力制御部１６に入力する回路構成に対しても、上記と同様に先行車速度演算部３０、減速度検出部３４、先行車への接近予測部３５及び警報部３６を設けることによって、同様の作用効果を有する車間距離制御装置を構成することができる。
【０１９９】
次に、本発明の第１３の実施の形態の車間距離制御装置を、図３１及び図３２に基づいて説明する。第１３の実施の形態の車間距離制御装置は、第１２の実施の形態と同様の車間距離検出部１１、車速検出部１２、車間距離制御部１５、駆動力制御部１６、スロットルアクチュエータ１７及びブレーキアクチュエータ１８を備え、また減速度検出部３４を備えている。
【０２００】
この実施の形態の車間距離制御装置はさらに、本発明の特徴として車速検出部１２からの自車速ｖａと減速度検出部３４からの減速度β１から制御領域をオーバーしていないかどうか判断する制御領域オーバ予測部３７と、制御領域オーバーと判断した場合に警報を出力する警報部３８を備えている。
【０２０１】
次に、上記構成の第１３の実施の形態の動作を、図３２のフローチャートを参照して説明する。第１２の実施の形態と同様に、先行車との車間距離ｄａを検出し、先行車に対する相対速度ｖｂを演算し、自車速ｖａを検出し、これらを車間距離制御部１５に入力する（ステップＳ５１〜Ｓ５３）。
【０２０２】
車間距離制御部１５は制駆動力Ｆｔを演算して駆動力制御部１６に与え、駆動力制御部１６は与えられる制駆動力Ｆｔに応じて、スロットル開度ｓａ、ブレーキ液圧ｂａを演算して求め（ステップＳ５４）、スロットルアクチュエータ１７、ブレーキアクチュエータ１８は与えられる指令値に一致するようにスロットル開度、ブレーキ液圧を作動させる（ステップＳ５５）。
【０２０３】
減速度検出部３４は第１２の実施の形態と同様に数２８式によって減速度β１を求め、制御領域オーバ予測部３７に入力する（ステップＳ５６）。
【０２０４】
制御領域オーバ予測部３７は、自車速ｖａと減速度検出部３４からの減速度β１から制御解除速度を超えるまでの時間を、次に数３０式によって予測演算する（ステップＳ５７）。
【０２０５】
［数３０］
制御領域オーバー到達予測時間Ｔ
＝（自車速ｖａ−解除速度ｖｄ）／減速度β１
そしてこの予測時間Ｔが所定値よりも短ければ、警報部３８によって警報を出力させてドライバに知らせる（ステップＳ５８，Ｓ５９）。
【０２０６】
なお、自車の減速度の演算は上記の方法によらず、自車速ｖａを時間微分し、あるいは時間差分によって算出することも可能であり、特に限定されることはない。
【０２０７】
これによって、第１３の実施の形態によれば、自車速ｖａと減速度β１に応じて制御領域をオーバーしないかどうか予測判断し、制御領域をオーバーすると予測した場合には警報を出力するようにしたので、第１１の実施の形態と同様に（１）〜（３）の効果を奏する。
【図面の簡単な説明】
【図１】 本発明の第１の実施の形態の構成を示すブロック図。
【図２】 上記の実施の形態の動作を示すフローチャート。
【図３】 上記の実施の形態における駆動力制御部の内部回路図。
【図４】 上記の実施の形態において駆動力制御部が利用するエンジンマップ。
【図５】 上記の実施の形態における車間距離検出部のセンシングエリアを示す説明図。
【図６】 本発明の第２の実施の形態の構成を示すブロック図。
【図７】 上記の実施の形態の動作を示すフローチャート。
【図８】 本発明の第３の実施の形態の構成を示すフローチャート。
【図９】 上記の実施の形態の動作を示すフローチャート。
【図１０】 本発明の第４の実施の形態の構成を示すフローチャート。
【図１１】 上記の実施の形態の動作を示すフローチャート。
【図１２】 本発明の第５の実施の形態の構成を示すフローチャート。
【図１３】 上記の実施の形態の動作を示すフローチャート。
【図１４】 本発明の第６の実施の形態の構成を示すフローチャート。
【図１５】 上記の実施の形態の動作を示すフローチャート。
【図１６】 本発明の第７の実施の形態の構成を示すフローチャート。
【図１７】 上記の実施の形態の動作を示すフローチャート。
【図１８】 上記の実施の形態による制動力特性を示すグラフ。
【図１９】 本発明の第８の実施の形態の構成を示すフローチャート。
【図２０】 上記の実施の形態の動作を示すフローチャート。
【図２１】 本発明の第９の実施の形態の構成を示すフローチャート。
【図２２】 上記の実施の形態の動作を示すフローチャート。
【図２３】 上記の実施の形態の動作特性を示すタイミングチャート。
【図２４】 本発明の第１０の実施の形態の構成を示すフローチャート。
【図２５】 上記の実施の形態の動作を示すフローチャート。
【図２６】 本発明の第１１の実施の形態の構成を示すフローチャート。
【図２７】 上記の実施の形態の動作を示すフローチャート。
【図２８】 本発明の第１２の実施の形態の構成を示すフローチャート。
【図２９】 上記の実施の形態の動作を示すフローチャート。
【図３０】 上記の実施の形態で採用するブレーキ液圧−減速度特性のグラフ。
【図３１】 本発明の第１３の実施の形態の構成を示すフローチャート。
【図３２】 上記の実施の形態の動作を示すフローチャート。
【図３３】 従来例の動作を示すフローチャート。
【図３４】 一般的な車間距離検出装置の検出特性の説明図。
【符号の説明】
１１ 車間距離検出部
１２ 車速検出部
１３ 相対速度演算部
１４ 目標車間距離演算部
１５ 車間距離制御部
１５ａ 車間距離制御部
１５ｂ 車速制御部
１６ 駆動力制御部
１７ スロットルアクチュエータ
１８ ブレーキアクチュエータ
１９ レーン幅検出部
２０ センシング可能性判断部
２１ 制動力緩和解除部
２１ａ 減速度緩和解除部
２２ 解除速度設定部
２３ 速度制御領域判断部
２５ 制動力保持部
２５ａ 減速度保持部
２６ 制動力調整部
２６ａ 減速度調整部
２７ 警報部
３０ 先行車速度検出部
３１ 制御領域オーバ予測部
３２ 警報部
３４ 減速度検出部
３５ 先行車への接近予測部
３６ 警報部
３７ 制御領域オーバ予測部
３８ 警報部[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to an inter-vehicle distance control device.
[0002]
[Prior art]
  Conventionally, the control area is set based on the sensing area of the inter-vehicle distance sensor, and when the control area is exceeded, the control area setting and release functions are provided to release the braking force and deceleration. As an inter-vehicle distance control device that performs both of the above and the like, for example, it is described in Japanese Patent Application Laid-Open No. 8-118996, and one shown in FIG. This conventional inter-vehicle distance control device is considered to prohibit the release during the deceleration control even if the vehicle speed is lower than the release speed, and to prevent the possibility of being too close to the preceding vehicle. Is.
[0003]
[Problems to be solved by the invention]
  However, such a conventional inter-vehicle distance control device has the following problems. As shown in the sensing angle a in FIG. 34, the radar apparatus 1 as the inter-vehicle distance sensor has an expansion w1 as it goes farther, so that the nearby sensing area w2 becomes narrower. By avoiding this, if the sensing angle is widened as shown in b in the figure, it is possible to detect a nearby preceding vehicle 2, but this increases the cost and also prevents the vehicle 3 and obstacles in the adjacent lane. In order to detect, the recognition logic of the preceding vehicles 2 and 4 becomes complicated. For this reason, a radar apparatus having a sensing angle that is too wide cannot be employed, and the radar apparatus 1 having a sensing area a is employed.
[0004]
  However, when the radar apparatus 1 with a sensing angle of a is employed, when the vehicle is traveling at a low speed with a close inter-vehicle distance, the sensing angle w2 becomes narrower than the lane width w3, and the preceding vehicle 2 is removed and is not detected. Sometimes, in the low speed range below the release speed, the detection of the inter-vehicle distance is undetermined, making it difficult to execute the deceleration control based on the inter-vehicle distance. Therefore, in such a situation, that is, in the low speed range below the release speed, since detection of the inter-vehicle distance is uncertain, it is preferable to give a warning to make the driver perceive it.
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[0006]
  The present invention has been made in view of such conventional problems,When canceling inter-vehicle distance control due to exceeding the control range, cancel inter-vehicle distance control while gradually reducing the deceleration according to the vehicle speed or over time, or decrease when the control range is exceeded. It is an object of the present invention to provide an inter-vehicle distance control device that can avoid a sudden change in the braking / driving behavior of a vehicle when the speed is maintained by maintaining the speed.
[0007]
  It is another object of the present invention to provide an inter-vehicle distance control device capable of giving a warning to a driver in advance in a situation where inter-vehicle distance control is predicted to be canceled in the near future and preparing for the cancellation of the inter-vehicle distance control. To do.
[0008]
[Means for Solving the Problems]
  The feature of the invention is that the vehicle isDistance between vehiclesAn inter-vehicle distance detecting means for detecting a vehicle, an inter-vehicle distance control means for controlling the braking / driving force to control the actual inter-vehicle distance to a target inter-vehicle distance, and a relative speed detecting means for detecting a relative speed between the preceding vehicle and the own vehicle. A control area judging means for judging whether or not the own vehicle speed is equal to or lower than a preset control release speed, and when the control area judging means judges that the own vehicle speed is equal to or lower than the control release speed, When the vehicle distance control cancellation means for canceling the distance control and the control area determination means determine that the host vehicle speed is equal to or lower than the control cancellation speed,Decide the degree of deceleration according to the relative speed in the direction away from the preceding vehicle immediately before the judgment, and change the braking force after canceling the inter-vehicle distance controlAnd an inter-vehicle distance control device including a deceleration adjusting means.
[0009]
  In the above-mentioned inter-vehicle distance control device, the inter-vehicle distance detection means detects the inter-vehicle distance between the host vehicle and the preceding vehicle, and the inter-vehicle distance control means controls the braking / driving force to control the actual inter-vehicle distance to the target inter-vehicle distance. . At the same time, the control area determination means determines whether the host vehicle speed is equal to or lower than the preset control release speed, and determines that the host vehicle speed is equal to or lower than the control release speed. The inter-vehicle distance control of the inter-vehicle distance control means is canceled by the canceling means. When canceling the inter-vehicle distance control, the deceleration immediately before canceling the inter-vehicle distance control is gradually relaxed according to the own vehicle speed or the elapsed time by the deceleration relaxing means, or immediately before canceling the inter-vehicle distance control by the deceleration holding means. Maintain the deceleration or use the deceleration adjustment means to adjust the relative speed immediately before canceling the inter-vehicle distance control and the actual inter-vehicle distance.Based on this, the braking force immediately before canceling the inter-vehicle distance control is changed after canceling the inter-vehicle distance control so that the greater the degree of approach to the preceding vehicle, the greater the deceleration.This avoids adverse effects caused by suddenly canceling the inter-vehicle distance control.
[0010]
  In the control area determination means, it is determined that the host vehicle speed is equal to or lower than the control release speed. You may provide the alarm means which outputs an alarm when cut off.
[0011]
Further, the warning means may cause a shock that can be perceived by the driver by abruptly changing the braking / driving force.
[0012]
  The deceleration adjusting means includesThe greater the relative speed in the direction away from the preceding vehicle just before the judgment, the smaller the degree of deceleration.It doesn't matter.
[0013]
  The deceleration adjusting means gradually increases the braking force as the host vehicle speed decreases after the inter-vehicle distance control is released when the braking force immediately before the inter-vehicle distance control is released is increased after the inter-vehicle distance control is released. It doesn't matter.
[0014]
  The deceleration adjusting means may increase the braking force immediately before the cancellation of the inter-vehicle distance control after the cancellation of the inter-vehicle distance control, and gradually increase the braking force with the passage of time after the cancellation of the inter-vehicle distance control. I do not care.
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[0036]
【The invention's effect】
  According to the present invention, when the inter-vehicle distance control is canceled because the host vehicle speed exceeds the speed control region, the deceleration adjusting meansDecide the degree of deceleration according to the relative speed in the direction away from the preceding vehicle just before the judgment, and change the braking force after canceling the inter-vehicle distance controlThus, it is possible to avoid the adverse effects caused by suddenly canceling the inter-vehicle distance control.
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[0046]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an inter-vehicle distance control apparatus according to a first embodiment of the present invention. The inter-vehicle distance control device according to the first embodiment detects, for example, the inter-vehicle distance da from the preceding vehicle based on a time delay from the timing at which the laser is transmitted to the timing at which the reflected light reflected from the rear portion of the preceding vehicle is reflected. The following vehicle is detected based on the temporal change in the inter-vehicle distance da detected by the inter-vehicle distance detector 11, the inter-vehicle distance detector 11 that detects the own vehicle speed va by a wheel speed pulse, and the inter-vehicle distance detector 11. A relative speed calculation unit 13 for calculating a relative speed vb with respect to the vehicle, a target inter-vehicle distance calculation unit 14 for calculating a target inter-vehicle distance db according to the vehicle speed va, and an actual inter-vehicle distance da from the relative speed vb and the vehicle speed va. The inter-vehicle distance control unit 15 that calculates the braking / driving force Ft to control the throttle, and the throttle opening sa and the block according to the braking / driving force Ft from the inter-vehicle distance control unit 15 Using a driving force control unit 16 for calculating the hydraulic pressure ba, a method of pulling a wire by a motor or a throttle actuator 17 for controlling a throttle opening using an electronic throttle, a method of controlling a piston by a motor, and others And a brake actuator 18 for controlling the brake fluid pressure.
[0047]
  The inter-vehicle distance control device according to this embodiment further features, as a feature of the present invention, a lane width detection unit 19 that captures a road condition ahead of the vehicle with a camera or the like and detects a lane width lw by image processing, a target inter-vehicle distance db and a lane Sensing possibility determination unit 20 that determines whether or not a preceding vehicle can be detected in the following inter-vehicle distance from the width lw, and inter-vehicle distance control while gradually reducing the braking force according to the vehicle speed va when the host vehicle exceeds the control region. A braking force relaxation releasing unit 21 for releasing is provided.
[0048]
  Next, the operation of the inter-vehicle distance control device of the first embodiment having the above configuration will be described with reference to the flowchart of FIG. The inter-vehicle distance detection unit 11 detects the inter-vehicle distance da with the preceding vehicle, and the relative speed calculation unit 13 detects the relative speed vb () of the host vehicle with respect to the preceding vehicle by temporal change of the inter-vehicle distance da, for example, time differentiation or time difference calculation. If the vehicle speed is positive, it calculates a separation tendency and if it is negative, the vehicle speed va is detected by the vehicle speed detector 12, and the vehicle speed da, the vehicle speed va, and the relative speed vb are input to the inter-vehicle distance controller 15. (Steps S11 to S13).
[0049]
  Further, the target inter-vehicle distance calculation unit 14 calculates an appropriate inter-vehicle distance, that is, the target inter-vehicle distance db with respect to the host vehicle speed va detected by the vehicle speed detection unit 12 and outputs the calculated inter-vehicle distance control unit 15 and the sensing possibility determination unit 20. (Step S14).
[0050]
  This target inter-vehicle distance db is, for example,
[Equation 1]
    Target inter-vehicle distance db = A × own vehicle speed va + B
Obtained by the formula
[0051]
  Here, A and B are constants, and A is set to 2 seconds (inter-vehicle time), for example, to obtain a position that reaches a certain time after the current speed of the host vehicle. Set the offset value (margin distance).
[0052]
  The intervehicular distance control unit 15 calculates the braking / driving force Ft from the input relative speed vb, intervehicular distance da, and target intervehicular distance db according to the following equation (2), and supplies the braking / driving force Ft to the driving force control unit 16.
[0053]
[Equation 2]
    Target braking / driving force Ft = P1 × (vehicle distance da−target vehicle distance db)
                          + P2 × relative speed vb
  Here, P1 and P2 are control gains.
[0054]
  The driving force control unit 16 calculates and obtains the throttle opening sa and the brake fluid pressure ba based on the control characteristics shown in FIGS. 3 and 4 according to the applied braking / driving force Ft (step S15).
[0055]
  First, the engine drive shaft torque Te is calculated from the target braking / driving force Ft and the transmission gear ratio Gr by the following equation (3).
[0056]
[Equation 3]
    Engine shaft torque Te = (target braking / driving force Ft × tire radius)
                          / (Gear ratio Gr × 9.8)
  Then, the throttle opening degree sa is selected from the engine shaft torque Te and the engine speed Ne according to the engine map shown in FIG.
[0057]
  The brake fluid pressure ba is calculated by the following equation (4).
[0058]
[Equation 4]
    Brake fluid pressure ba = −drive force Ft / Bp
  Here, Bp is a braking force conversion constant.
[0059]
  On the other hand, for example, the lane width detection unit 19 captures a scene ahead of the road with a camera, detects the distance between the left and right road white lines, that is, the lane width lw by image processing, and supplies the detected distance to the sensing possibility determination unit 20 (step). S16). Then, the sensing possibility determination unit 20 compares whether or not the detection width w of the inter-vehicle distance detection unit 11 in the following inter-vehicle distance L is smaller than the actual lane width lw (step S17).
[0060]
  Here, if the inter-vehicle distance detection width w in the following inter-vehicle distance is larger than the actual lane width lw, it is determined that the preceding vehicle can be sensed, and the step is not intervened in the braking / driving force Ft output from the inter-vehicle distance control unit 15. The process proceeds to S19.
[0061]
  In step S19, normally, the throttle opening sa and the brake hydraulic pressure ba calculated by the driving force control unit 16 are given to the throttle actuator 17 and the brake actuator 18, respectively, and command values given to the throttle actuator 17 and the brake actuator 18 are given. Thus, the throttle opening and the brake fluid pressure are actuated so as to coincide with each other, the own vehicle speed is adjusted, and control is performed so that the own vehicle follows the preceding vehicle while maintaining the target inter-vehicle distance (steps S19 and S20).
[0062]
  However, if the detection width w of the inter-vehicle distance detection unit 11 in the following inter-vehicle distance is smaller than the lane width lw, the sensing possibility determination unit 20 determines that the preceding vehicle cannot be sensed in step S17 and determines the braking force relaxation control command. Is output to the braking force relaxation release unit 21.
[0063]
  Here, as shown in FIG. 5, when the detection width w of the inter-vehicle distance detection unit 11 in the following inter-vehicle distance is a detection angle (sensing angle) θ and the following inter-vehicle distance L, the following equation 5 is obtained.
[0064]
[Equation 5]
    Detection width w = 2L tan (θ / 2)
  If the sensing possibility determination unit 20 determines that sensing cannot be performed, the braking force relaxation release unit 21 calculates a braking force command value Ft2 from the vehicle speed detection value according to the following equation (6) (step S18).
[0065]
[Equation 6]
    Braking force command value Ft2
        = Braking force Ft1 according to equation 2 just before sensing impossible
          + C1 x (speed va1-vehicle speed detection value va2 when sensing is impossible)
  However, C1 is a constant.
[0066]
  The inter-vehicle distance control unit 15 outputs the applied braking force command value Ft2 as the braking / driving force Ft to the driving force control unit 16 to control the braking force (steps S19 and S20).
[0067]
  If the braking force command value Ft2 is calculated by the above equation (6) and the driving force is controlled as a new braking / driving force command value Ft, the value Ft1 (original Ft) calculated by the equation (2) at the control release speed is obtained. It is connected smoothly and continuously, and the braking force can be weakened gradually.
[0068]
  In the first embodiment, when the inter-vehicle distance control is canceled, the braking force Ft calculated by the inter-vehicle distance control unit 15 is gradually relaxed. Instead of this, the following equation (7) is used. In addition, it is possible to employ control in which the braking force command value Ft is gradually relaxed according to time.
[0069]
[Equation 7]
    Braking force command value Ft2
        = Braking force Ft1 according to equation 2 just before sensing impossible
          + C2 x elapsed time t from sensing impossible judgment t
  However, C2 is a constant.
[0070]
  Next, an inter-vehicle distance control apparatus according to a second embodiment of the present invention will be described with reference to FIGS. The second embodiment is characterized in that, compared to the first embodiment shown in FIG. 1, the inter-vehicle distance control unit 15a receives an inter-vehicle distance da, a target inter-vehicle distance db, an own vehicle speed va, and a relative speed. The vehicle target speed vc and deceleration α required to make the actual inter-vehicle distance da coincide with the target inter-vehicle distance db by vb are calculated, and the vehicle speed control unit 15b requires the braking / driving force required for the target speed vc. Ft is calculated and applied to the driving force control unit 16, and the driving force control unit 16 calculates the throttle opening sa and the brake hydraulic pressure ba in the same manner as in the first embodiment, so that the throttle actuator 17 and the brake actuator 18 are Further, the deceleration relaxation release unit 21a in place of the braking force relaxation release unit 21 in the first embodiment is configured to control the sensing possibility determination unit 20 to determine the sensing impossible result. Only, the adjusted by a calculation described later deceleration α1 computed vehicle distance control section 15a, lies in that to return the distance control unit 15a. In the second embodiment, the elements other than those described above are the same as those in the first embodiment shown in FIG.
[0071]
  In the inter-vehicle distance control apparatus according to the second embodiment, as shown in the flowchart of FIG. 7, the inter-vehicle distance detection unit 11 detects the inter-vehicle distance da and the relative speed calculation unit 13 as in the first embodiment. To calculate the relative speed vb, the vehicle speed detecting unit 12 detects the own vehicle speed va, and the target inter-vehicle distance calculating unit 14 calculates the target inter-vehicle distance db (steps S11 to S14).
[0072]
  The inter-vehicle distance control unit 15a calculates a target vehicle speed vc for controlling to the target inter-vehicle distance db obtained by the following equation (8) from the input relative speed vb, the inter-vehicle distance da, and the target inter-vehicle distance db. (Step S15a).
[0073]
[Equation 8]
    Target vehicle speed vc = F1 × (vehicle distance da−target vehicle distance db)
                    + F2 × relative speed vb + (own vehicle speed va + relative speed vb)
  Here, F1 and F2 are control gains, and (own vehicle speed va + relative speed vb) is the speed of the preceding vehicle.
[0074]
  The target vehicle speed vc obtained by Equation 8 is a speed for making the inter-vehicle distance da coincide with the target inter-vehicle distance db and making the vehicle speed va coincide with the speed of the preceding vehicle. The vehicle speed control unit 15b calculates a target braking / driving force Ft for making the host vehicle speed va coincide with the given target vehicle speed vc, for example, using the following equation (9).
[0075]
[Equation 9]

  However, G1, G2, and G3 are control gains.
[0076]
  Then, the driving force control unit 16 calculates the throttle opening sa and the brake hydraulic pressure ba according to the target driving force Ft, as in the first embodiment.
[0077]
  The inter-vehicle distance control unit 15a also calculates the deceleration α1 by time-differentiating the target vehicle speed vc generated by the inter-vehicle distance control as shown in the following equation (10) (step S15b).
[0078]
[Expression 10]

  Next, as in the first embodiment, the lane width detection unit 19 detects the lane width lw (step S16), and the sensing possibility determination unit 20 detects the detection width of the inter-vehicle distance detection unit 11 at the following inter-vehicle distance L. It is compared whether w is smaller than the actual lane width lw (step S17).
[0079]
  If the inter-vehicle distance detection width w in the following inter-vehicle distance is larger than the actual lane width lw, it is determined that the preceding vehicle can be sensed, and the process proceeds to step S19. As in the first embodiment, the driving force control unit 16 The throttle opening and brake fluid pressure are controlled so as to match the calculated throttle opening sa and the brake fluid pressure ba to adjust the own vehicle speed and follow the preceding vehicle while maintaining the target inter-vehicle distance. Control is performed (steps S19 and S20).
[0080]
  However, if the sensing possibility determination unit 20 determines that the preceding vehicle cannot be sensed in step S17 because the detection width w of the inter-vehicle distance detection unit 11 in the following inter-vehicle distance is smaller than the lane width lw, the deceleration relaxation control command Is output to the deceleration relaxation releasing unit 21a.
[0081]
  The deceleration relaxation releasing unit 21a calculates the deceleration command value α2 from the deceleration command value α1 from the inter-vehicle distance control unit 15a by the following equation (11) (step S18a).
[0082]
[Equation 11]
    Deceleration command value α2
        = Deceleration α1 according to Equation 10 immediately before sensing impossible
          + D1 × (speed when sensing is impossible−vehicle speed detection value va)
  However, D1 is a constant.
[0083]
  The inter-vehicle distance control unit 15a calculates the target vehicle speed vc2 again based on the adjusted deceleration force command value α2 that is given and outputs it to the vehicle speed control unit 15b. Thereafter, as in the case of the normal control, the vehicle speed control unit The braking / driving force Ft2 with respect to the target vehicle speed vc2 is calculated at 15b, and the throttle actuator 17 and the brake actuator 18 are controlled by the driving force control unit 16 to perform deceleration control (steps S19 and S20).
[0084]
  In this way, if the deceleration command value α2 is calculated by Equation 11 and a new braking force command value Ft2 based on this is calculated and the driving force is controlled, the braking force calculated by Equation 2 at the control release speed is obtained. Ft1 (original Ft) is connected smoothly and continuously, and the deceleration can be gradually reduced.
[0085]
  In the second embodiment, when the vehicle speed control is released, the deceleration calculated by the inter-vehicle distance control unit 15a is gradually relaxed. Instead of this, the following equation 12 is used to reduce the deceleration. Control in which the speed command value α2 is gradually relaxed according to time can also be employed.
[0086]
[Equation 12]
    Deceleration command value α2
        = Deceleration α1 according to Equation 10 immediately before sensing impossible
          + D2 × Elapsed time t from sensing impossible judgment
  However, D2 is a constant.
[0087]
  In this case, the target vehicle speed vc2 is recalculated from the deceleration command value α2 by the following equation (13), and deceleration control is performed based on this.
[0088]
[Equation 13]
    Target vehicle speed vc2 = Target vehicle speed vc according to equation (8) just before sensing impossible
                    + Deceleration command value α2 × Elapsed time t
  According to the first and second embodiments, the control region is set according to the sensing limit, and the braking force or the deceleration is gradually increased according to the vehicle speed or the passage of time even if the host vehicle exceeds the control region. Since control is released while relaxing,
  (1) The control area can be set according to the sensing limit, and the traveling control according to the sensor signal can be reliably performed.
  (2) Rather than canceling the deceleration control suddenly in the area exceeding the sensing limit, the deceleration control can be maintained in the area exceeding the sensing limit.
  (3) When it becomes the control release area, it is possible to prevent the deterioration of the ride comfort by using the data immediately before becoming the release area,
  (4) The control can be gradually stopped so that the driver can perceive that the control is released in the low speed range before the control is completely released (during braking force relaxation or deceleration relaxation release). Can do.
[0089]
  Next, an inter-vehicle distance control apparatus according to a third embodiment of the present invention will be described with reference to FIGS. The feature of the third embodiment is that a release speed setting unit 22 is provided instead of the lane width detection unit 19 and the sensing possibility determination unit 20 is replaced with the first embodiment shown in FIG. The other components are the same as those in the first embodiment in that the speed control region determination unit 23 is provided.
[0090]
  The release speed setting unit 22 holds a control release speed value vd set in advance. The release speed vd is a value obtained as follows. Assuming that the value is H using a general road width, the inter-vehicle distance L at which the inter-vehicle distance detection unit 11 has a detection width w greater than or equal to the road width by the sensing angle θ is as described in the first embodiment. In addition, it is obtained from the equation (5), and is equal to or greater than L in the following equation (14).
[0091]
[Formula 14]
    L = H / (2.tan (θ / 2))
  Therefore, the speed to be controlled to the inter-vehicle distance L is obtained from Equation 1 and set to the release speed vd.
[0092]
[Equation 15]
    Release speed vd = (LB) / A
  However, A and B are constants used in Equation 1.
[0093]
  The speed control region determination unit 23 compares the vehicle speed detection value va from the vehicle speed detection unit 12 with the release speed vd from the release speed setting unit 21, and continues the inter-vehicle distance control if the vehicle speed detection value va is larger than the release speed. When the vehicle speed detection value va becomes equal to or less than the release speed, a braking force relaxation control command is output to the braking force relaxation release unit 21.
[0094]
  Next, the operation of the inter-vehicle distance control apparatus according to the third embodiment will be described with reference to the flowchart of FIG. In the normal inter-vehicle distance control, the inter-vehicle distance detection unit 11 detects the inter-vehicle distance da, the relative speed calculation unit 13 calculates the relative speed vb, as in the processing of the first embodiment shown in FIG. The host vehicle speed va is detected by the vehicle speed detector 12, and the target inter-vehicle distance db is calculated by the target inter-vehicle distance calculator 14 and input to the inter-vehicle distance controller 15 (steps S11 to S14).
[0095]
  The intervehicular distance control unit 15 calculates the braking / driving force Ft from the input relative speed vb, intervehicular distance da, and target intervehicular distance db, and gives the driving force control unit 16 (step S15).
[0096]
  Then, the speed control release determination unit 23 compares the vehicle speed detection value va with the release speed vd. If the vehicle speed detection value va is larger than the release speed, the inter-vehicle distance control is continued and the vehicle speed detection value va becomes less than the release speed. If so, a braking force relaxation control command is output to the braking force relaxation release unit 21 (step S17a).
[0097]
  When the speed control cancellation determination unit 23 determines to continue the inter-vehicle distance control in step S17a, the braking force relaxation cancellation unit 21 intervenes in the braking / driving force Ft output from the inter-vehicle distance control unit 15 as in the first embodiment. First, the throttle opening sa and the brake hydraulic pressure ba calculated by the driving force control unit 16 are given to the throttle actuator 17 and the brake actuator 18, respectively, and the throttle actuator 17 and the brake actuator 18 open the throttle so as to coincide with the given command values. The brake fluid pressure is actuated to adjust the own vehicle speed, and control is performed so that the own vehicle follows the preceding vehicle while maintaining the target inter-vehicle distance (steps S19 and S20).
[0098]
  On the other hand, when the speed control cancellation determination unit 23 determines that the braking force relaxation release is determined in step S17a, the braking force relaxation cancellation unit 21 determines the vehicle speed detection value va according to the following equation 16 as in the first embodiment. The braking force command value Ft2 is calculated from (step S18), and the inter-vehicle distance control unit 15 outputs the applied braking force command value Ft2 as the braking / driving force Ft to the driving force control unit 16 to control the braking force (step S19). , S20).
[0099]
[Equation 16]
    Braking force command value Ft2
        = Braking force Ft1 according to equation 2 just before reaching the release speed
          + C1 × (speed va1 at the time of release speed arrival determination−vehicle speed detection value va2)
  However, C1 is a constant.
[0100]
  Thus, according to the third embodiment, when the host vehicle speed va becomes equal to or lower than the preset release speed vd, the braking force command value Ft2 is calculated by the above-described equation 16, and this is applied to a new braking / driving operation. By controlling the driving force as the force command value Ft, the value Ft1 (original Ft) calculated by the formula 2 at the control release speed vd can be smoothly and continuously connected, and the braking force can be gradually reduced according to the vehicle speed. it can.
[0101]
  In the third embodiment described above, the braking force Ft calculated by the inter-vehicle distance control unit 15 when the inter-vehicle distance control is released is gradually reduced according to the vehicle speed. As in the case of the embodiment, it is possible to employ control in which the braking force command value Ft is gradually relaxed according to time by the following equation (17).
[0102]
[Equation 17]
    Braking force command value Ft2
        = Braking force Ft1 according to equation 2 just before reaching the release speed
          + C2 × Elapsed time t from determination of release speed arrival
  However, C2 is a constant.
[0103]
  Next, the inter-vehicle distance according to the fourth embodiment of the present invention will be described with reference to FIGS. The feature of the fourth embodiment is that the inter-vehicle distance control unit 15a is different from the third embodiment shown in FIG. 8 in the same way as the second embodiment with respect to the first embodiment. Based on the input inter-vehicle distance da, the target inter-vehicle distance db, the own vehicle speed va, and the relative speed vb, the target vehicle speed vc and the deceleration α necessary for making the actual inter-vehicle distance da coincide with the target inter-vehicle distance db are calculated. The vehicle speed control unit 15b calculates the braking / driving force Ft necessary for the target speed vc and applies the braking / driving force Ft to the driving force control unit 16, and the driving force control unit 16 controls the throttle opening as in the first embodiment. sa and the brake hydraulic pressure ba are calculated to control the throttle actuator 17 and the brake actuator 18, and the deceleration relaxation release unit 21a in place of the braking force relaxation release unit 21 in the third embodiment is used as a speed. Upon receiving the determination result of the control release rate reaches the control region determining unit 23 to adjust the deceleration α1 computed vehicle distance control section 15a, lies in that to return the distance control unit 15a. In the fourth embodiment, the elements other than those described above are the same as those in the third embodiment shown in FIG.
[0104]
  In the inter-vehicle distance control device according to the fourth embodiment, as shown in the flowchart of FIG. 11, the inter-vehicle distance detection unit 11 detects the inter-vehicle distance da and the relative speed calculation unit 13 as in the third embodiment. To calculate the relative speed vb, the vehicle speed detecting unit 12 detects the own vehicle speed va, and the target inter-vehicle distance calculating unit 14 calculates the target inter-vehicle distance db (steps S11 to S14).
[0105]
  The inter-vehicle distance control unit 15a calculates the target vehicle speed vc from the input relative speed vb, inter-vehicle distance da, and target inter-vehicle distance db according to the equation 8 described in the second embodiment (step S15a). The inter-vehicle distance control unit 15a also calculates the deceleration α1 by differentiating the target vehicle speed vc generated by the inter-vehicle distance control with respect to time based on the equation (10) (step S15b).
[0106]
  The vehicle speed control unit 15b calculates the target braking / driving force Ft for making the host vehicle speed va coincide with the given target vehicle speed vc by the above-described equation (9). Then, the driving force control unit 16 calculates the throttle opening sa and the brake hydraulic pressure ba according to the target driving force Ft, as in the third embodiment.
[0107]
  Next, as in the third embodiment, the speed control release determination unit 23 compares the vehicle speed detection value va with the release speed vd, and if the vehicle speed detection value va is greater than the release speed, the inter-vehicle distance control is continued. If the vehicle speed detection value va becomes equal to or less than the release speed, a deceleration relaxation control command is output to the deceleration relaxation release unit 21a (step S17a).
[0108]
  When the speed control cancellation determination unit 23 determines to continue the inter-vehicle distance control in step S17a, the deceleration relaxation cancellation unit 21a does not intervene in the target vehicle speed vc output from the inter-vehicle distance control unit 15a, and is calculated by the vehicle speed control unit 15b. The driving force control unit 16 calculates the throttle opening sa and the brake fluid pressure ba with respect to the braking / driving force Ft and applies them to the throttle actuator 17 and the brake actuator 18 respectively to control the throttle opening and the brake fluid pressure. The own vehicle speed is adjusted, and control is performed so that the own vehicle follows the preceding vehicle while maintaining the target inter-vehicle distance (steps S19 and S20).
[0109]
  On the other hand, when the speed control cancellation determination unit 23 determines that the deceleration relaxation cancellation is performed in step S17a, the deceleration relaxation control command is output to the deceleration relaxation cancellation unit 21a, and the deceleration relaxation cancellation unit 21a is the inter-vehicle distance control unit. Similarly to the second embodiment, the deceleration command value α2 from the deceleration command value α1 from 15a is calculated according to Equation 18 (step S18a).
[0110]
[Equation 18]
    Deceleration command value α2
        = Deceleration α1 according to Equation 10 immediately before reaching the release speed arrival determination
          + D1 × (speed at the time of release speed arrival determination−vehicle speed detection value va)
  However, D1 is a constant.
[0111]
  The inter-vehicle distance control unit 15a calculates the target vehicle speed vc2 again based on the supplied adjusted deceleration force command value α2 and outputs it to the vehicle speed control unit 15b (step S18b). Thereafter, as in the case of normal control, The vehicle speed control unit 15b calculates the braking / driving force Ft2 with respect to the target vehicle speed vc2, and the driving force control unit 16 controls the throttle actuator 17 and the brake actuator 18 to perform deceleration control (steps S19 and S20).
[0112]
  In this way, if the deceleration command value α2 is calculated by the equation (18), and the new braking force command value Ft2 based on this is calculated and the driving force is controlled, the braking force calculated by the equation (2) at the control release speed is obtained. Ft1 (original Ft) is connected smoothly and continuously, and the deceleration can be gradually reduced.
[0113]
  In the fourth embodiment, when the vehicle speed control is released, the deceleration calculated by the inter-vehicle distance control unit 15a is gradually relaxed. However, as in the case of the second embodiment, It is also possible to employ control in which the deceleration command value α2 is gradually relaxed according to time by the following equation (19).
[0114]
[Equation 19]
    Deceleration command value α2
        = Deceleration α1 according to Equation 10 immediately before reaching the release speed arrival determination
          + D2 × elapsed time t from determination of release speed arrival
  However, D2 is a constant.
[0115]
  In this case, the target vehicle speed vc2 is recalculated from the deceleration command value α2 by the following equation (20), and deceleration control is performed based on this.
[0116]
[Equation 20]
    Target vehicle speed vc2 = target vehicle speed vc according to equation (8) just before the determination of reaching the release speed
                    + Deceleration command value α2 × Elapsed time t
  According to the inter-vehicle distance control devices of the third and fourth embodiments, the control is canceled while gradually reducing the braking force or deceleration according to the vehicle speed or time even if the host vehicle exceeds the control region. Thus, the effects (1) to (4) are obtained as in the first and second embodiments.
[0117]
  Next, an inter-vehicle distance control apparatus according to a fifth embodiment of the present invention will be described with reference to FIGS. The feature of the fifth embodiment is that a braking force holding portion 25 is provided instead of the braking force relaxation releasing portion 24 with respect to the third embodiment shown in FIG. Is the same as that of the third embodiment.
[0118]
  When the speed control area determination unit 23 outputs a braking force holding command when the vehicle speed detection value va becomes equal to or less than the release speed vd based on the control area determination, the braking force holding unit 25 outputs the inter-vehicle distance control unit 15 at the time of this determination. The braking force holding value Ft2 (= Ft1) is output to the driving force control unit 16 so as to hold the braking force Ft1 (= Ft).
[0119]
  Next, the operation of the inter-vehicle distance control apparatus according to the fifth embodiment will be described with reference to the flowchart of FIG. In the normal inter-vehicle distance control, the inter-vehicle distance detection unit 11 detects the inter-vehicle distance da, the relative speed calculation unit 13 calculates the relative speed vb, as in the processing of the first embodiment shown in FIG. The host vehicle speed va is detected by the vehicle speed detector 12, the target inter-vehicle distance db is calculated by the target inter-vehicle distance calculator 14, and is output to the inter-vehicle distance controller 15 (steps S 11 to S 14). The driving force Ft is calculated and given to the driving force control unit 16 (step S15).
[0120]
  Then, the speed control release determination unit 23 compares the vehicle speed detection value va and the release speed vd as in the third embodiment, and if the vehicle speed detection value va is larger than the release speed, the inter-vehicle distance control is continued. If the detected value va is equal to or lower than the release speed, a braking force holding control command is output to the braking force holding unit 25 (step S17a).
[0121]
  When the speed control release determining unit 23 determines to continue the inter-vehicle distance control in step S17a, the braking force holding unit 25 does not intervene in the braking / driving force Ft output from the inter-vehicle distance control unit 15, and the calculation of the driving force control unit 16 is performed. The throttle opening sa and the brake hydraulic pressure ba are applied to the throttle actuator 17 and the brake actuator 18 respectively, and the throttle opening and the brake hydraulic pressure are operated so that the throttle actuator 17 and the brake actuator 18 coincide with the command values given. The own vehicle speed is adjusted, and control is performed so that the own vehicle follows the preceding vehicle while maintaining the target inter-vehicle distance (steps S19 and S20).
[0122]
  On the other hand, when the speed control release determination unit 23 determines that the braking force is held in step S17a, the braking force holding unit 25 holds the braking force command value Ft1 immediately before the release speed arrival determination obtained from the inter-vehicle distance control unit 15. This is output to the driving force control unit 16 as a braking force command value Ft (step S18c), and the braking force is controlled (steps S19 and S20).
[0123]
  Thus, according to the fifth embodiment, when the host vehicle speed va becomes equal to or lower than the preset release speed vd, the braking force command value Ft1 immediately before the release speed arrival determination is held, and this is used as the braking / driving force command. By controlling the driving force as the value Ft, the braking force corresponding to the immediately preceding vehicle speed va is maintained even if the host vehicle exceeds the control region, so that the braking force is not suddenly released.
[0124]
  Next, the inter-vehicle distance according to the sixth embodiment of the present invention will be described with reference to FIGS. The feature of the sixth embodiment is that the inter-vehicle distance control unit 15a is different from the fifth embodiment shown in FIG. 12 in the same way as the fourth embodiment with respect to the third embodiment. Based on the input inter-vehicle distance da, the target inter-vehicle distance db, the own vehicle speed va, and the relative speed vb, the target vehicle speed vc and the deceleration α necessary for making the actual inter-vehicle distance da coincide with the target inter-vehicle distance db are calculated. The vehicle speed control unit 15b calculates the braking / driving force Ft necessary for the target speed vc and applies the braking / driving force Ft to the driving force control unit 16, and the driving force control unit 16 controls the throttle opening as in the first embodiment. The throttle actuator 17 and the brake actuator 18 are controlled by calculating sa and the brake hydraulic pressure ba. Further, a deceleration holding unit 25a in place of the braking force holding unit 25 in the fifth embodiment has a speed control range. In response to control release rate reaches the determination result of the determination unit 23 lies in that to hold the deceleration α1 computed vehicle distance control section 15a to control release immediately before. In the sixth embodiment, the elements other than those described above are the same as those of the fifth embodiment shown in FIG.
[0125]
  In the inter-vehicle distance control device according to the sixth embodiment, as shown in the flowchart of FIG. 15, the inter-vehicle distance detection unit 11 detects the inter-vehicle distance da as in the fourth embodiment shown in the flowchart of FIG. Then, the relative speed calculator 13 calculates the relative speed vb, the vehicle speed detector 12 detects the host vehicle speed va, and the target inter-vehicle distance calculator 14 calculates the target inter-vehicle distance db (steps S11 to S14).
[0126]
  Then, the inter-vehicle distance control unit 15a calculates the target vehicle speed vc according to the above equation (8) (step S15a). Further, the inter-vehicle distance control unit 15a also calculates the deceleration α1 by differentiating the target vehicle speed vc generated by the inter-vehicle distance control with respect to time using the above-described equation (10) (step S15b).
[0127]
  Next, the speed control release determination unit 23 compares the vehicle speed detection value va with the release speed vd, and if the vehicle speed detection value va is larger than the release speed, the inter-vehicle distance control is continued, and the vehicle speed detection value va is less than the release speed. If this is the case, a deceleration holding control command is output to the deceleration holding unit 25a (step S17a).
[0128]
  When the speed control release determining unit 23 determines to continue the inter-vehicle distance control in step S17a, the deceleration holding unit 25a does not intervene in the target vehicle speed vc output from the inter-vehicle distance control unit 15a, and is the same as in the fourth embodiment. Then, the vehicle speed control unit 15b calculates the braking / driving force Ft, and applies the throttle opening sa and the brake hydraulic pressure ba calculated by the driving force control unit 16 to the throttle actuator 17 and the brake actuator 18, respectively. Then, the brake fluid pressure is controlled to increase or decrease the own vehicle speed, and control is performed so that the own vehicle follows the preceding vehicle while maintaining the target inter-vehicle distance (steps S19 and S20).
[0129]
  On the other hand, when the speed control release determining unit 23 determines that the deceleration is held in step S17a, the deceleration holding control command is output to the deceleration holding unit 25a, and the deceleration holding unit 25a is sent from the inter-vehicle distance control unit 15a. The deceleration command value α1 immediately before reaching the release speed is held and returned to the inter-vehicle distance control unit 15a as α2 (= α1) (step S18d).
[0130]
  As in the second embodiment, the inter-vehicle distance control unit 15a calculates the target vehicle speed vc2 based on the deceleration force command value α2 (= α1) given from the deceleration holding unit 25a, and outputs it to the vehicle speed control unit 15b. (Step S18b) Thereafter, as in the case of the normal control, the vehicle speed control unit 15b calculates the braking / driving force Ft2 for the target vehicle speed vc2, and the driving force control unit 16 controls the throttle actuator 17 and the brake actuator 18. To control deceleration (steps S19 and S20).
[0131]
  In this way, in the sixth embodiment, when the vehicle speed control is released, the deceleration calculated by the inter-vehicle distance control unit 15a is maintained, and the driving force is controlled based on this, so that the host vehicle exceeds the control region. However, the deceleration corresponding to the immediately preceding vehicle speed va is maintained so that the deceleration is not released suddenly.
[0132]
  According to the inter-vehicle distance control device of the fifth and sixth embodiments, the braking force or deceleration is maintained even if the host vehicle exceeds the control region.
  (1) Deceleration control can be maintained even in areas that exceed the sensing limit.
  (2) When the control release area is entered, deterioration of riding comfort can be prevented by using the data immediately before the release area.
[0133]
  Next, an inter-vehicle distance control apparatus according to a seventh embodiment of the present invention will be described with reference to FIGS. The feature of the seventh embodiment is that a braking force adjusting unit 26 is provided instead of the braking force relaxation releasing unit 21 in the third embodiment shown in FIG. The vehicle functions to adjust the braking force by a method described later when the host vehicle exceeds the control region. Other components are the same as those in the third embodiment.
[0134]
  Next, the operation of the seventh embodiment will be described with reference to the flowchart of FIG. In the normal inter-vehicle distance control, as in the process of the third embodiment shown in FIG. 8, the inter-vehicle distance da is detected, the relative speed vb is calculated, the own vehicle speed va is detected, and the target inter-vehicle distance db Is calculated and applied to the inter-vehicle distance control unit 15 (steps S11 to S14), and the inter-vehicle distance control unit 15 calculates the braking / driving force Ft and supplies it to the driving force control unit 16 (step S15).
[0135]
  Then, the speed control release determination unit 23 compares the vehicle speed detection value va with the release speed vd. If the vehicle speed detection value va is larger than the release speed, the inter-vehicle distance control is continued and the vehicle speed detection value va becomes less than the release speed. If so, a braking force adjustment control command is output to the braking force adjustment unit 26 (step S17a).
[0136]
  When the speed control release determining unit 23 determines to continue the inter-vehicle distance control in step S17a, the braking force adjusting unit 26 does not intervene in the braking / driving force Ft output from the inter-vehicle distance control unit 15 as in the third embodiment. Then, each of the throttle actuator 17 and the brake actuator 18 is operated so as to coincide with the throttle opening sa calculated by the driving force control unit 16 and the brake hydraulic pressure ba to adjust the own vehicle speed, and the own vehicle is the target with respect to the preceding vehicle. Control is performed so as to follow while maintaining the inter-vehicle distance db (steps S19 and S20).
[0137]
  On the other hand, when the speed control cancellation determination unit 23 determines that the braking force adjustment control is performed in step S17a, the braking force adjustment unit 26 determines the following number according to the inter-vehicle distance da and the relative speed vb immediately before exceeding the control region. Based on the equation (21), the braking force Ft1 (= Ft) is adjusted to be relaxed, held or increased, and Ft2 obtained as a result of the adjustment is given to the driving force control unit 16 (step S18e).
[0138]
[Equation 21]
  (I) Relative speed vb ≦ predetermined value 1 (approaching the preceding vehicle)
    (I-1) Inter-vehicle distance va ≦ predetermined value 3
            The braking force is increased and controlled by the calculation of the following equation (22).
[0139]
    (I-2) Inter-vehicle distance va> predetermined value 3
            The braking force Ft1 immediately before reaching the release speed is held.
[0140]
  (Ii) In the case of relative speed vb ≧ predetermined value 2 (away from the preceding vehicle)
            Regardless of the inter-vehicle distance da, the braking force is relaxed and controlled by the calculation of Equation (16).
[0141]
  (Iii) When the predetermined value 2> the relative speed vb> the predetermined value 1 (cruising to the preceding vehicle)
    (Iii-1) Inter-vehicle distance da ≦ predetermined value 4
            The braking force Ft1 immediately before reaching the release speed is held.
[0142]
    (Iii-2) Inter-vehicle distance da> predetermined value 4
            The braking force is relaxed and controlled by the calculation of equation (16).
[0143]
  FIG. 18 shows the respective deceleration patterns when these are relaxed, retained, and enhanced. When increasing the braking force, the braking force is calculated by the following equation (22).
[0144]
[Equation 22]
    Braking force command value Ft2
          = Braking force according to Equation 2 just before reaching the release speed
              -C3 x (speed va1 when the release speed is reached-vehicle speed detection value va2)
  However, C3 is a constant.
[0145]
  Thus, when the braking force adjusting unit 26 calculates and determines the braking force command value Ft2 in step S18e, the inter-vehicle distance control unit 15 uses the applied braking force command value Ft2 as the braking / driving force Ft to the driving force control unit 16. The braking force is output and the braking force is controlled (steps S19 and S20).
[0146]
  In this way, according to the seventh embodiment, by calculating the braking force command value Ft2 according to the equation (22), the value calculated according to the equation (2) is smoothly and continuously connected at the control release speed. The braking force can be increased.
[0147]
  In the seventh embodiment as well, as in the case of the third embodiment, when the braking force command value Ft2 is increased, a value corresponding to time as shown in the following Expression 23 is used. It can also be used.
[0148]
[Equation 23]
    Braking force command value Ft2
          = Braking force according to Equation 2 just before reaching the release speed
              -C4 x elapsed time t since the release speed was reached
  However, C4 is a constant.
[0149]
  Next, an inter-vehicle distance control apparatus according to an eighth embodiment of the present invention will be described with reference to FIGS. As in the case of the fourth embodiment shown in FIG. 10 with respect to the third embodiment shown in FIG. 8, the eighth embodiment is the same as that in the seventh embodiment shown in FIG. Instead of the power adjusting unit 26, a deceleration adjusting unit 26a is provided. The deceleration adjusting unit 26a functions to adjust the deceleration by a method described later when the host vehicle exceeds the control region.
[0150]
  Next, the operation of the eighth embodiment will be described with reference to the flowchart of FIG. In the normal inter-vehicle distance control, the inter-vehicle distance detection unit 11 detects the inter-vehicle distance da and the relative speed calculation unit 13 calculates the relative speed vb, as in the process of the fourth embodiment shown in FIG. The host vehicle speed va is detected by the vehicle speed detector 12, the target inter-vehicle distance db is calculated by the target inter-vehicle distance calculator 14 (steps S 11 to S 14), and the inter-vehicle distance controller 15 a receives the input relative speed vb and inter-vehicle distance da. The target vehicle speed vc is calculated from the target inter-vehicle distance db (step S15a). The inter-vehicle distance control unit 15a also calculates the deceleration α1 by differentiating the target vehicle speed vc generated by the inter-vehicle distance control with respect to time (step S15b).
[0151]
  The vehicle speed control unit 15b calculates the target braking / driving force Ft for making the host vehicle speed va coincide with the given target vehicle speed vc by the above-described equation (9). Then, the driving force control unit 16 calculates the throttle opening sa and the brake hydraulic pressure ba according to the target driving force Ft, as in the third embodiment.
[0152]
  Next, the speed control release determination unit 23 compares the vehicle speed detection value va with the release speed vd, and if the vehicle speed detection value va is larger than the release speed, the inter-vehicle distance control is continued, and the vehicle speed detection value va is less than the release speed. If this is the case, a deceleration adjustment control command is output to the deceleration adjustment unit 26a (step S17a).
[0153]
  If the speed control release determining unit 23 determines in step S17a that the inter-vehicle distance control is to be continued, the deceleration adjusting unit 26a does not intervene in the target vehicle speed vc output from the inter-vehicle distance control unit 15a, and the control calculated by the vehicle speed control unit 15b. The driving force control unit 16 calculates the throttle opening sa and the brake hydraulic pressure ba with respect to the driving force Ft, and applies them to the throttle actuator 17 and the brake actuator 18 respectively, and controls the throttle opening and the brake hydraulic pressure to control the driving force Ft. The vehicle speed is adjusted so that the own vehicle follows the preceding vehicle while maintaining the target inter-vehicle distance (steps S19 and S20).
[0154]
  On the other hand, when the speed control release determination unit 23 determines that the control range has been exceeded in step S17a, the deceleration adjustment control command is output to the deceleration adjustment unit 26a, and the deceleration adjustment unit 26a is transmitted from the inter-vehicle distance control unit 15a. In response to the deceleration command value α1, the calculation to increase, hold or relax the deceleration command value α1 is performed based on the following equation (24) according to the inter-vehicle distance da1 and the relative speed vb1 immediately before reaching the release speed. Then, the adjustment result is output to the inter-vehicle distance control unit 15a as a deceleration command α2 (step S18f).
[0155]
[Equation 24]
  (I) Relative speed vb ≦ predetermined value 1 (approaching the preceding vehicle)
    (I-1) Inter-vehicle distance va ≦ predetermined value 3
            The deceleration is increased and controlled by the calculation of the following equation (25).
[0156]
    (I-2) Inter-vehicle distance va> predetermined value 3
            The deceleration α1 immediately before reaching the release speed is held.
[0157]
  (Ii) In the case of relative speed vb ≧ predetermined value 2 (away from the preceding vehicle)
            Regardless of the inter-vehicular distance da, the deceleration is relaxed by the calculation of Equation 18.
[0158]
  (Iii) When the predetermined value 2> the relative speed vb> the predetermined value 1 (cruising to the preceding vehicle)
    (Iii-1) Inter-vehicle distance da ≦ predetermined value 4
            The deceleration α1 immediately before reaching the release speed is held.
[0159]
    (Iii-2) Inter-vehicle distance da> predetermined value 4
            The deceleration is relaxed by the calculation of Equation (18).
[0160]
  In the case of increasing the deceleration, a value obtained by obtaining the deceleration α2 by the following equation (25) is used.
[0161]
[Equation 25]
    Deceleration command value α2
        = Deceleration α1 according to Equation 10 immediately before reaching the release speed arrival determination
          −D3 × (speed at the time of release speed arrival determination−vehicle speed detection value va)
  However, D3 is a constant.
[0162]
  The inter-vehicle distance control unit 15a calculates the target vehicle speed vc2 again based on the supplied adjusted deceleration force command value α2 and outputs it to the vehicle speed control unit 15b (step S18b). Thereafter, as in the case of normal control, The vehicle speed control unit 15b calculates the braking / driving force Ft2 with respect to the target vehicle speed vc2, and the driving force control unit 16 controls the throttle actuator 17 and the brake actuator 18 to perform deceleration control (steps S19 and S20).
[0163]
  In this way, according to the eighth embodiment, by calculating the deceleration command value α2 according to Equation 24, the value calculated with Equation 10 at the control release speed is smoothly and continuously connected, and gradually Deceleration can be strengthened.
[0164]
  In the eighth embodiment, as in the case of the fourth embodiment, when the deceleration command value α2 is increased, a value corresponding to time is shown as shown in the following equation (26). It can also be used.
[0165]
[Equation 26]
    Deceleration command value α2
          = Deceleration according to Equation 10 just before reaching the release speed
              -D4 × Elapsed time t from when the release speed is reached
  However, D4 is a constant.
[0166]
  In this way, according to the seventh and eighth embodiments, even if the host vehicle exceeds the control region, it depends on the detected vehicle distance and the relative speed immediately before exceeding the control region, depending on the vehicle speed or time. Since the braking force or deceleration is adjusted, in addition to the effects of the fifth and sixth embodiments, the braking force or deceleration is adjusted appropriately according to the relative relationship with the preceding vehicle when the control range is exceeded. The effect which can be done is produced.
[0167]
  Next, an inter-vehicle distance control apparatus according to a ninth embodiment of the present invention will be described with reference to FIGS. The ninth embodiment is characterized in that an alarm unit 27 is additionally provided in addition to the braking force adjustment unit 26 with respect to the seventh embodiment shown in FIG. This alarm unit 27 is for notifying the driver that the speed control region has been exceeded by sound from the speaker or LED display when receiving a determination output from the speed control region determination unit 23 that the speed control region has been exceeded. . All other components are common to the seventh embodiment shown in FIG. 16 and function in the same manner.
[0168]
  In the case of the ninth embodiment, the operation is the same as that of the seventh embodiment shown in FIG. 16, but as shown in the flowchart of FIG. 22, the operation of the seventh embodiment is shown in FIG. In addition to the braking force command value output in step S18e by the braking force adjustment unit 26, an alarm output by the alarm unit 27 in step S18g is added to the flowchart. That is, when the speed control region determination unit 23 determines that the speed control region is exceeded in step S17a, the braking force adjustment unit 26 determines the vehicle speed or time according to the inter-vehicle distance da and the relative speed vb immediately before exceeding the control region. Accordingly, the braking force Ft1 (= Ft) is adjusted to be relaxed, held or increased, and Ft2 obtained as a result of the adjustment is given to the driving force control unit 16 (step S18e). The driver is informed by an alarm sound or a display output informing that it has been exceeded (step S18g). Then, the throttle opening and the brake fluid pressure are controlled to adjust the braking force (steps S19 and S29).
[0169]
  Thus, in the case of the ninth embodiment, even if the host vehicle speed exceeds the speed control region, the braking force is applied according to the vehicle speed or time according to the detected inter-vehicle distance and the relative speed immediately before exceeding the control region. In addition to the effects of the seventh embodiment, it is possible to adjust and notify the driver by warning. It can be released.
[0170]
  The alarm unit 27 in the ninth embodiment employs a means for causing the driver to detect a light shock by suddenly changing the braking force in place of or together with the alarm sound or the alarm display means. You can also That is, as shown in FIGS. 23 (a) and 23 (b), when the host vehicle speed va becomes the release speed, the braking force command value Ft output by the inter-vehicle distance control unit 15 is set to 0 or returned to the original. The brake fluid pressure ba (see (c) in the figure) that responds temporarily is varied several times between 0 and the original value, causing a slight shock to the vehicle and setting the control area for the driver. It is perceived that the inter-vehicle distance control is canceled due to exceeding.
[0171]
  In the ninth embodiment, the alarm unit 27 is additionally provided to the seventh embodiment shown in FIG. 16, but instead of this, the eighth embodiment shown in FIG. The alarm unit 27 may be additionally provided together with the speed adjustment unit 26a with respect to the embodiment. In this case as well, the alarm unit 27 employs an alarm sound or alarm display means, as in the ninth embodiment, or employs a means for performing an operation of temporarily changing the deceleration. . In the operation in this case, an alarm output step is added after step S18f to the flowchart of the eighth embodiment shown in FIG.
[0172]
  According to the ninth embodiment, even if the vehicle speed exceeds the speed control region, the braking force or the time depends on the vehicle speed or time according to the detected inter-vehicle distance and the relative speed immediately before exceeding the control region. Deceleration can be adjusted and the driver can be informed by an alarm. In addition to the effects of the seventh and eighth embodiments, the driver is notified when shifting to braking force adjustment or deceleration adjustment in the low speed range. It is possible to cancel the inter-vehicle distance control early by informing the vehicle.
[0173]
  The alarm unit 27 employed in the ninth embodiment includes the braking force relaxation releasing unit 21 shown in FIG. 1, the deceleration relaxation releasing unit 21a shown in FIG. 6, and the braking force relaxation releasing unit shown in FIG. 21, the deceleration relaxation release unit 21 a in FIG. 10, the braking force holding unit 25 in FIG. 12, or the deceleration holding unit 24 in FIG. 14, thereby enabling the driver to release the inter-vehicle distance control. Will be able to recognize it early.
[0174]
  Next, an inter-vehicle distance control apparatus according to a tenth embodiment of the present invention will be described with reference to FIGS. The feature of the tenth embodiment is that the braking force adjusting unit 26 is omitted from the seventh embodiment shown in FIG. 16 and an alarm unit 27 is provided instead. As in the ninth embodiment, when the alarm unit 27 receives a determination output indicating that the speed control region has been exceeded from the speed control region determination unit 23, the alarm unit 27 uses a speaker sound or LED display, or shown in FIG. This is to inform the driver that the speed control range has been exceeded. All other components are common to the seventh embodiment shown in FIG. 16 and function in the same manner.
[0175]
  In the case of the tenth embodiment, in the normal inter-vehicle distance control, the inter-vehicle distance da is detected, the relative speed vb is calculated, and the own vehicle speed is calculated, as in the processing of the third embodiment shown in FIG. va is detected, and the target inter-vehicle distance db is calculated and applied to the inter-vehicle distance control unit 15 (steps S11 to S14), and the inter-vehicle distance control unit 15 calculates the braking / driving force Ft and supplies it to the driving force control unit 16 ( Step S15).
[0176]
  Then, the speed control release determination unit 23 compares the vehicle speed detection value va with the release speed vd. If the vehicle speed detection value va is larger than the release speed, the inter-vehicle distance control is continued and the vehicle speed detection value va becomes less than the release speed. For example, a control release command is output to the inter-vehicle distance control unit 15 and the alarm unit 27 (step S17a).
[0177]
  When the speed control release determining unit 23 determines to continue the inter-vehicle distance control in step S17a, the braking force adjusting unit 26 does not intervene in the braking / driving force Ft output from the inter-vehicle distance control unit 15 as in the third embodiment. Then, each of the throttle actuator 17 and the brake actuator 18 is operated so as to coincide with the throttle opening sa calculated by the driving force control unit 16 and the brake hydraulic pressure ba to adjust the own vehicle speed, and the own vehicle is the target with respect to the preceding vehicle. Control is performed so as to follow while maintaining the inter-vehicle distance db (steps S19 and S20).
[0178]
  On the other hand, when the speed control cancellation determination unit 23 determines that the control is canceled in step S17a, the inter-vehicle distance control unit 15 stops the inter-vehicle distance control, and the alarm unit 27 that receives the control cancellation command simultaneously issues an alarm. Output to inform the driver (steps S17b, S17c).
[0179]
  As described above, according to the tenth embodiment, when the vehicle speed exceeds the speed control region, the driver can be notified by an alarm sound, a display, or a slight shock.
[0180]
  As in the tenth embodiment, it is possible to omit the deceleration adjustment unit 26a in the eighth embodiment shown in FIG. 19 and provide only the alarm unit 27 instead. The same effects as in the tenth embodiment are achieved.
[0181]
  Next, an inter-vehicle distance control apparatus according to an eleventh embodiment of the present invention will be described with reference to FIGS. The inter-vehicle distance control device according to the eleventh embodiment includes an inter-vehicle distance detection unit 11, a vehicle speed detection unit 12, a driving force control unit 16, a throttle actuator 17 and a brake actuator similar to those in the first embodiment shown in FIG. 18 is provided.
[0182]
  The inter-vehicle distance control apparatus according to this embodiment is further characterized by calculating the braking / driving force Ft necessary for controlling the actual inter-vehicle distance to the target inter-vehicle distance according to the inter-vehicle distance da and the relative speed vb. A distance control unit 15, a preceding vehicle speed calculation unit 30 that calculates the speed ve of the preceding vehicle from the relative speed vb from the relative speed calculation unit 13 and the host vehicle speed va from the vehicle speed detection unit 12; A control area over prediction unit 31 that compares the set control release speed vd of the host vehicle to predict whether or not the host vehicle will exceed the release speed vd, and an alarm sound or alarm according to the control area over prediction result And an alarm unit 32 for outputting a display.
[0183]
  Next, the operation of the eleventh embodiment will be described with reference to the flowchart of FIG. The inter-vehicle distance detection unit 11 detects the inter-vehicle distance da with the preceding vehicle, the relative speed calculation unit 13 calculates the relative speed vb, the vehicle speed detection unit 12 detects the host vehicle speed va, and the vehicle speed da, the vehicle speed va, The relative speed vb is input to the inter-vehicle distance control unit 15 (steps S21 to S23).
[0184]
  Then, an appropriate inter-vehicle distance with respect to the host vehicle speed va, that is, the target inter-vehicle distance db is calculated by the equation (1), and the braking / driving force Ft is calculated by the equation (2) from the relative speed vb, the inter-vehicle distance da, and the target inter-vehicle distance db. To the driving force control unit 16. Similar to the first embodiment, the driving force control unit 16 calculates the throttle opening sa and the brake hydraulic pressure ba based on the control characteristics shown in FIGS. 3 and 4 according to the applied braking / driving force Ft. The throttle opening sa and the brake hydraulic pressure ba are given to the throttle actuator 17 and the brake actuator 18, respectively, and the throttle opening 17 so that the throttle actuator 17 and the brake actuator 18 coincide with the command values given. The brake fluid pressure is activated (step S25).
[0185]
  The preceding vehicle speed calculation unit 30 calculates the preceding vehicle speed ve by the following equation (27) and inputs it to the control region over prediction unit 31 (step S26).
[0186]
[Equation 27]
    Prior vehicle speed ve = own vehicle speed va + relative speed vb
  The control region over predicting unit 31 compares the preceding vehicle speed ve with a preset control release speed vd (step S27).
[0187]
  If it is determined in step S27 that the preceding vehicle speed ve is larger, the following vehicle speed va should also be higher than the control release speed vd, so the control is not released and the inter-vehicle distance control is continued. On the contrary, if the preceding vehicle speed ve is equal to or lower than the control release speed vd, it is predicted that the vehicle speed va following the vehicle speed va will immediately decrease below the control release speed vd. 32, the alarm unit 32 outputs an alarm (step S28).
[0188]
  Thus, according to the eleventh embodiment, when the preceding vehicle speed ve exceeds the speed control region vd, a warning is given that the vehicle may also exceed the speed control region.
  (1) If the control is not canceled during deceleration control as in the conventional example, it is difficult to perform automatic deceleration control based on the inter-vehicle distance at low speeds, but the driver is warned early and the inter-vehicle distance control is stopped. Can be
  (2) When the configuration is such that the control is canceled when the following inter-vehicle distance is exceeded, there is a possibility that if the control is automatically canceled during deceleration, the vehicle may be too close to the preceding vehicle. By doing so, you can make an approach avoidance approach early,
  (3) Even when it is configured to gradually cancel the control when the control region is exceeded as in the first to eighth embodiments, the driver can be warned and the inter-vehicle distance control can be stopped early. .
[0189]
  In the eleventh embodiment shown in FIG. 26, the braking / driving force Ft is calculated by the inter-vehicle distance control unit 15, and the throttle opening sa corresponding to the braking / driving force Ft and the brake hydraulic pressure are calculated by the driving force control unit 16. The inter-vehicle distance control device that calculates the throttle opening and brake fluid pressure by calculating ba has been described. However, the target vehicle speed vc is calculated by the inter-vehicle distance control unit 15a as in the second, fourth, and sixth embodiments. In contrast to this, for the circuit configuration in which the vehicle speed control unit 15b calculates the braking / driving force Ft and inputs the braking / driving force Ft to the driving force control unit 16, the preceding vehicle speed calculation unit 30 is similar to the eleventh embodiment. By providing the control region over prediction unit 31 and the warning unit 32, it is possible to configure an inter-vehicle distance control device having the same function and effect.
[0190]
  Next, a twelfth embodiment of the present invention will be described with reference to FIGS. The inter-vehicle distance control device according to the twelfth embodiment includes an inter-vehicle distance detection unit 11, a vehicle speed detection unit 12, an inter-vehicle distance control unit 15, a driving force control unit 16, a throttle actuator 17, and the like as in the eleventh embodiment. A brake actuator 18 is provided, and a preceding vehicle speed calculation unit 30 is further provided.
[0191]
  The inter-vehicle distance control device of this embodiment is further characterized as a feature of the present invention, a deceleration detection unit 34 for detecting deceleration according to the brake hydraulic pressure ba output from the driving force control unit 16, a brake until control release, An alarm that outputs an alarm based on the judgment result of the approach prediction unit 35 to the preceding vehicle that predicts whether or not the preceding vehicle is too close by the deceleration by the engine brake after the release of control, and the approach prediction unit 35 to the preceding vehicle A portion 36 is provided.
[0192]
  Next, the operation of the twelfth embodiment having the above configuration will be described with reference to the flowchart of FIG. As in the eleventh embodiment, the inter-vehicle distance detection unit 11 detects the inter-vehicle distance da with the preceding vehicle, the relative speed calculation unit 13 calculates the relative speed vb, and the vehicle speed detection unit 12 detects the host vehicle speed va. Then, these vehicle speed da, vehicle speed va, and relative speed vb are input to the inter-vehicle distance control unit 15 (steps S31 to S33). The inter-vehicle distance control unit 15 calculates the braking / driving force Ft and applies it to the driving force control unit 16, and the driving force control unit 16 calculates the throttle opening sa and the brake hydraulic pressure ba according to the applied braking / driving force Ft. Then, the throttle actuator 17 and the brake actuator 18 actuate the throttle opening and the brake hydraulic pressure so as to coincide with the given command values (step S35).
[0193]
  Similar to the eleventh embodiment, the preceding vehicle speed calculation unit 30 calculates the preceding vehicle speed ve by the above-described equation 27 and inputs it to the approaching prediction unit 35 for the preceding vehicle (step S36). Further, the deceleration detection unit 34 receives the brake fluid pressure command value ba output from the driving force control unit 16 and obtains the deceleration β1 corresponding to the brake fluid pressure command value ba from the following equation 28 to the preceding vehicle. To the approach prediction unit 35 (step S37).
[0194]
[Equation 28]
    Brake deceleration β1 = E1 × brake hydraulic pressure ba + E2
  However, E1 and E2 are constants and are values obtained by linearly approximating experimental values as shown in FIG. Note that the calculation of the deceleration β1 of the own vehicle is not limited to the above method, and the own vehicle speed va can be calculated by time differentiation or by time difference.
[0195]
  The approach predicting unit 35 for the preceding vehicle selects the deceleration β2 due to engine braking after the release of control (step S38), and then the preceding vehicle speed ve from the preceding vehicle speed calculating unit 30 and the deceleration detecting unit 34 are selected. Based on the brake deceleration β1 until the control is released, the deceleration β2 due to the engine brake after the control is released, and the preset release speed vd, the approach distance is calculated by the following equation (29) (step S39).
[0196]
[Equation 29]
  Approach distance dc = inter-vehicle distance detection value da
    -(Own vehicle speed va-release speed vd)²/ (2 x brake deceleration β1)
    -(Release speed vd-preceding vehicle speed ve)²/ (2 x engine brake deceleration β2)
  Then, the obtained approach distance dc is compared with a predetermined value, and if the approach distance dc is smaller than the predetermined value, the alarm unit 36 outputs an approach warning to the preceding vehicle and notifies the driver (steps S40 and S41). ).
[0197]
  As a result, according to the twelfth embodiment, it is predicted whether or not the preceding vehicle will be approached too much due to the deceleration by the brake until the control is released and the engine brake after the control is released. By outputting, the effects (1) to (3) are obtained as in the eleventh embodiment.
[0198]
  In the twelfth embodiment shown in FIG. 28, the braking / driving force Ft is calculated by the inter-vehicle distance control unit 15, and the throttle opening sa corresponding to the braking / driving force Ft and the brake fluid are calculated by the driving force control unit 16. Although the inter-vehicle distance control device that calculates the pressure ba and adjusts the throttle opening and the brake hydraulic pressure has been described, the inter-vehicle distance control unit 15a sets the target vehicle speed vc as in the second, fourth, and sixth embodiments. For the circuit configuration in which the vehicle speed control unit 15b calculates the braking / driving force Ft and inputs the braking / driving force Ft to the driving force control unit 16, the preceding vehicle speed calculation unit 30 and the deceleration detection unit are similar to the above. 34. By providing the approach prediction unit 35 and the warning unit 36 for the preceding vehicle, it is possible to configure an inter-vehicle distance control device having the same function and effect.
[0199]
  Next, an inter-vehicle distance control apparatus according to a thirteenth embodiment of the present invention will be described with reference to FIGS. The inter-vehicle distance control device according to the thirteenth embodiment includes an inter-vehicle distance detection unit 11, a vehicle speed detection unit 12, an inter-vehicle distance control unit 15, a driving force control unit 16, a throttle actuator 17, and a brake similar to those in the twelfth embodiment. An actuator 18 is provided, and a deceleration detector 34 is provided.
[0200]
  The inter-vehicle distance control device according to this embodiment is further characterized in that as a feature of the present invention, it is determined whether or not the control range is exceeded from the own vehicle speed va from the vehicle speed detection unit 12 and the deceleration β1 from the deceleration detection unit 34. A region over prediction unit 37 and a warning unit 38 that outputs a warning when it is determined that the control region is over are provided.
[0201]
  Next, the operation of the thirteenth embodiment having the above configuration will be described with reference to the flowchart of FIG. Similar to the twelfth embodiment, the inter-vehicle distance da with the preceding vehicle is detected, the relative speed vb with respect to the preceding vehicle is calculated, the own vehicle speed va is detected, and these are input to the inter-vehicle distance control unit 15 (step) S51-S53).
[0202]
  The inter-vehicle distance control unit 15 calculates the braking / driving force Ft and applies the braking / driving force Ft to the driving force control unit 16, and the driving force control unit 16 calculates the throttle opening sa and the brake fluid pressure ba according to the applied braking / driving force Ft. Then, the throttle actuator 17 and the brake actuator 18 actuate the throttle opening and the brake hydraulic pressure so as to coincide with the given command values (step S55).
[0203]
  As in the twelfth embodiment, the deceleration detection unit 34 obtains the deceleration β1 by Equation 28 and inputs it to the control region over prediction unit 37 (step S56).
[0204]
  The control region over prediction unit 37 predicts and calculates the time from the own vehicle speed va and the deceleration β1 from the deceleration detection unit 34 until the control release speed is exceeded, using Equation 30 (step S57).
[0205]
[Equation 30]
    Control region overestimated predicted time T
            = (Own vehicle speed va-release speed vd) / deceleration β1
  If the predicted time T is shorter than a predetermined value, the alarm unit 38 outputs an alarm to notify the driver (steps S58 and S59).
[0206]
  Note that the calculation of the deceleration of the host vehicle is not limited to the above method, and the host vehicle speed va can be time-differentiated or calculated by a time difference, and is not particularly limited.
[0207]
  Thus, according to the thirteenth embodiment, whether or not the control region is exceeded is predicted according to the own vehicle speed va and the deceleration β1, and an alarm is output when it is predicted that the control region will be exceeded. Therefore, the effects (1) to (3) are obtained as in the eleventh embodiment.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a first exemplary embodiment of the present invention.
FIG. 2 is a flowchart showing the operation of the above embodiment.
FIG. 3 is an internal circuit diagram of a driving force control unit in the embodiment.
FIG. 4 is an engine map used by the driving force control unit in the embodiment.
FIG. 5 is an explanatory diagram showing a sensing area of an inter-vehicle distance detection unit in the embodiment.
FIG. 6 is a block diagram showing a configuration of a second exemplary embodiment of the present invention.
FIG. 7 is a flowchart showing the operation of the above embodiment.
FIG. 8 is a flowchart showing the configuration of the third exemplary embodiment of the present invention.
FIG. 9 is a flowchart showing the operation of the embodiment.
FIG. 10 is a flowchart showing the configuration of the fourth exemplary embodiment of the present invention.
FIG. 11 is a flowchart showing the operation of the above embodiment.
FIG. 12 is a flowchart showing the configuration of the fifth embodiment of the present invention.
FIG. 13 is a flowchart showing the operation of the embodiment.
FIG. 14 is a flowchart showing the configuration of the sixth embodiment of the present invention.
FIG. 15 is a flowchart showing the operation of the embodiment.
FIG. 16 is a flowchart showing the configuration of the seventh exemplary embodiment of the present invention.
FIG. 17 is a flowchart showing the operation of the embodiment.
FIG. 18 is a graph showing braking force characteristics according to the embodiment.
FIG. 19 is a flowchart showing the configuration of the eighth embodiment of the present invention.
FIG. 20 is a flowchart showing the operation of the above embodiment.
FIG. 21 is a flowchart showing the configuration of the ninth embodiment of the present invention.
FIG. 22 is a flowchart showing the operation of the above embodiment.
FIG. 23 is a timing chart showing operating characteristics of the above embodiment.
FIG. 24 is a flowchart showing the configuration of the tenth embodiment of the present invention.
FIG. 25 is a flowchart showing the operation of the above embodiment.
FIG. 26 is a flowchart showing the configuration of the eleventh embodiment of the present invention.
FIG. 27 is a flowchart showing the operation of the above embodiment.
FIG. 28 is a flowchart showing the configuration of the twelfth embodiment of the present invention.
FIG. 29 is a flowchart showing the operation of the above embodiment.
FIG. 30 is a graph of brake fluid pressure-deceleration characteristics employed in the above embodiment.
FIG. 31 is a flowchart showing the configuration of the thirteenth embodiment of the present invention.
FIG. 32 is a flowchart showing the operation of the above embodiment.
FIG. 33 is a flowchart showing the operation of a conventional example.
FIG. 34 is an explanatory diagram of detection characteristics of a general inter-vehicle distance detection device.
[Explanation of symbols]
  11 Inter-vehicle distance detector
  12 Vehicle speed detector
  13 Relative speed calculator
  14 Target vehicle distance calculator
  15 Inter-vehicle distance controller
  15a Inter-vehicle distance control unit
  15b Vehicle speed control unit
  16 Driving force control unit
  17 Throttle actuator
  18 Brake actuator
  19 Lane width detector
  20 Sensing possibility judgment part
  21 Braking force relaxation release part
  21a Deceleration release part
  22 Release speed setting section
  23 Speed control area determination unit
  25 Braking force holding part
  25a Deceleration holding part
  26 Braking force adjuster
  26a Deceleration adjustment unit
  27 Alarm section
  30 Leading vehicle speed detector
  31 Control region over prediction unit
  32 Alarm section
  34 Deceleration detector
  35 Approach prediction part to the preceding vehicle
  36 Alarm section
  37 Control region over prediction unit
  38 Alarm section

Claims (3)

An inter-vehicle distance detecting means for detecting an actual inter-vehicle distance between the host vehicle and the preceding vehicle;
An inter-vehicle distance control means for controlling the braking / driving force to control the actual inter-vehicle distance to the target inter-vehicle distance;
A relative speed detecting means for detecting a relative speed between the preceding vehicle and the own vehicle;
Control area determination means for determining whether the host vehicle speed is equal to or lower than a preset control release speed;
An inter-vehicle distance control canceling means for canceling the inter-vehicle distance control when the control area determining means determines that the host vehicle speed is equal to or less than the control canceling speed;
When the control area determination means determines that the host vehicle speed is equal to or lower than the control release speed, the degree of deceleration is determined according to the relative speed immediately before the determination, and the braking force is changed after the inter-vehicle distance control is released. A deceleration adjusting means,
The inter-vehicle distance control device characterized in that the deceleration adjusting means decreases the degree of deceleration as the relative speed in the direction away from the preceding vehicle immediately before the determination increases .
Inter-vehicle distance control device.   The inter-vehicle distance control device according to claim 1, further comprising alarm means for outputting an alarm when the control area determination means determines that the host vehicle speed is equal to or lower than the control release speed.   3. The inter-vehicle distance control device according to claim 2, wherein the warning means gives a sudden change in braking / driving force to cause a shock that can be perceived by the driver.

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