JP3649108B2 - Vehicle tracking control device - Google Patents

Description

これにより、制御ゲインＫ_spを適当な値に設定することにより、車速制御系の応答特性を、所望の応答特性に一致させることができる。
【００５７】
したがって、目標車速Ｖｓ^* と自車速Ｖｓとの偏差に制御ゲインＫ_SPを乗算した値と走行抵抗Ｔ_DHとの偏差から、駆動軸トルク指令値Ｔｑ^* を算出することができる。
図５は、前記駆動軸トルク制御部２６の詳細を示すブロック図である。図中、２６ａは、駆動軸トルク指令値Ｔｑ^* に基づいて、自動変速機３の状態やその変速比等を考慮してエンジントルク指令値Ｔ_E ^* を算出するエンジントルク指令値演算部、２６ｂは、エンジントルク指令値演算部２６ａで算出したエンジントルク指令値Ｔ_E ^* とエンジン出力制御装置９からのエンジン回転数Ｎ_E とをもとに、例えばエンジントルクとスロットル開度とエンジン回転数との対応を表すエンジンマップを参照すること等によって、エンジントルク指令値Ｔ_E ^* を出力させるためのスロットル開度指令値θ^* を演算するスロットル開度演算部である。
【００５８】
このスロットル開度演算部２６ｂで演算されたスロットル開度指令値θ^* は、エンジントルク演算部２６ｃに入力され、エンジントルク演算部２６ｃでは、スロットル開度指令値θ^* とエンジン回転数Ｎ_E とをもとに、例えば予め設定されたエンジン回転数Ｎ_E に対するエンジントルクを表すテーブルマップを参照して、スロットル開度が全閉状態である場合のエンジントルクＴ_ELIMを演算する。
【００５９】
前記エンジントルク演算部２６ｃで算出されたスロットル開度が全閉状態である場合のエンジントルクＴ_ELIMは、制駆動力補正値演算部２６ｄに入力され、この制駆動力補正値演算部２６ｄでは、このエンジントルクＴ_ELIMに基づいてスロットル開度が全閉状態であるときにエンジン２が発生する駆動軸トルクＴｑ₀ を算出し、制動力演算部２６ｅは、駆動軸トルク指令値Ｔｑ^* とスロットル開度が全閉状態であるときにエンジン２が発生する駆動軸トルクＴｑ₀ との差から、ブレーキ液圧サーボ系に入力するブレーキ操作量、すなわち制動圧指令値Ｐ_B ^* を算出する。
【００６０】
つまり、トルクコンバータのトルク増幅率をＲ_T 、自動変速機３の変速比をＲ_AT、ディファレンシャルギヤ比をＲ_DEF 、エンジンイナーシャをＪ_E 、エンジン回転数をＮ_E とすると、駆動軸トルクＴｑとエンジントルクＴ_E との関係は、次式（５）で表すことができる。
Ｔｑ＝Ｒ_T ・Ｒ_AT・Ｒ_DEF ・Ｔ_E −Ｊ_E ・（ｄＮ_E ／ｄｔ）……（５）
したがって、駆動軸トルク指令値Ｔｑ^* に対し、次式（６）に基づいてエンジントルク指令値Ｔ_E ^* を算出し、このエンジントルク指令値Ｔ_E ^* を発生させるスロットル開度θをエンジンマップを用いて算出し、このスロットル開度θが全閉であるか否かを判断する。
【００６１】
Ｔ_E ^* ＝Ｊ_E ・（ｄＮ_E ／ｄｔ）＋Ｔｑ^* ／（Ｒ_T ・Ｒ_AT・Ｒ_DEF ）……（６）
このエンジントルク指令値Ｔ_E ^* に基づき算出されるスロットル開度θが、θ＞０であれば、ブレーキを使わずにエンジントルクのみで駆動軸トルク指令値Ｔｑ^* で指定されたトルクを実現することができる。一方、θ＝０であれば、スロットル開度を全閉とし、このときのエンジン２によって出力される駆動軸トルクを考慮して駆動軸トルクを指令値に一致させるためのブレーキ操作量を演算する。
【００６２】
以上によって、前記エンジントルク指令値Ｔ_E ^* とブレーキトルク指令値Ｔ_BR ^* との分配制御則は次のようになる。すなわち、前記エンジントルク指令値Ｔ_E ^* に基づき算出されるスロットル開度指令値θ^* がθ^* ＞０であるときには、次式（７）となり、駆動軸トルク指令値Ｔｑ^* に対して（８）式に示すエンジントルクを発生させればよい。
【００６３】
Ｔ_BR＝０
Ｔｑ＝Ｒ_T ・Ｒ_AT・Ｒ_DEF ・Ｔ_E −Ｊ_E ・（ｄＮ_E ／ｄｔ）……（７）
Ｔ_E ＝Ｊ_E ・（ｄＮ_E ／ｄｔ）＋Ｔｑ^* ／（Ｒ_T ・Ｒ_AT・Ｒ_DEF ）……（８）
一方、スロットル開度指令値θ^* がθ^* ＝０であるときには、スロットル開度が零のときのエンジントルクをＴ_ELIMとすると、前記（５）式は、次式（９）となるから、駆動軸トルク指令値Ｔｑ^* に対して（１０）式のブレーキトルクを発生させればよい。
【００６４】
Ｔｑ＝Ｒ_T ・Ｒ_AT・Ｒ_DEF ・Ｔ_ELIM−Ｊ_E ・（ｄＮ_E ／ｄｔ）−Ｔ_BR……（９）
Ｔ_BR＝−Ｔｑ＋Ｒ_T ・Ｒ_AT・Ｒ_DEF ・Ｔ_ELIM−Ｊ_E ・（ｄＮ_E ／ｄｔ） ……（１０）
そして、ブレーキシリンダ面積をＳ_B 、ブレーキロータ半径をＲ_B 、ブレーキパッド摩擦係数をμ_B とすると、ブレーキトルク指令値Ｔ_BRに対してブレーキ操作量である制動圧指令値Ｐ_B ^* は、次式（１１）となる。
【００６５】
Ｐ_B ^* ＝Ｔ_BR／（８・Ｓ_B ・Ｒ_B ・μ_B ） ……（１１）
次に、上記第１の実施の形態の動作を、追従制御用コントローラ２０で実行する追従走行制御処理の処理手順を示す図６のフローチャートを伴って説明する。追従制御用コントローラ２０では、図６に示す追従走行制御処理を例えば１０ｍｓｅｃ毎のタイマ割り込み処理として実行する。なお、この処理は、セットスイッチ１４のスイッチ信号がオフ、つまり追従走行指示が行われていないとき、また、ブレーキスイッチ１９がオン状態、つまりブレーキペダル８ａが踏み込まれていると判定されるときには行わない。また、処理中で使用されるフラグＦ₁ 〜Ｆ₃ は起動時には初期値として零に設定されている。
【００６６】
前記追従制御用コントローラ２０では、まず、ステップＳ１で、車間距離センサ１２、車速センサ１３の各検出信号、また、セットスイッチ１４のスイッチ信号、車速設定装置１５の設定信号等を読み込み、自車速Ｖｓ、車間距離Ｌを算出する。次いで、ステップＳ２に移行し、ステップＳ１で算出した車間距離Ｌを微分して自車両と先行車両との相対車速Ｖｒを算出する。
【００６７】
次いで、ステップＳ３に移行して、先行車両を検出したか否かを判定する。この判定は、例えば、車間距離センサ１２の検出信号から車間距離Ｌを算出し、この車間距離Ｌが車間距離センサ１２の検出限界値以内であるかどうかを判定することにより行う。そして、車間距離Ｌが検出限界値よりも大きいときには先行車がないものと判断して、ステップＳ４でフラグＦ₁ 及びＦ₂ 及びＦ₃ をＦ₁ ＝０、Ｆ₂ ＝０、Ｆ₃ ＝０に設定した後、後述のステップＳ２２に移行する。一方、車間距離Ｌが検出限界値以内であるときには先行車があるものと判断してステップＳ５に移行する。
【００６８】
このステップＳ５では、一定車間時間で走行中であるかどうかを判定する。この判定は、例えば、相対車速Ｖｒの絶対値が所定値未満Ｖｒ_S （｜Ｖｒ｜＜Ｖｒ_S ）であり、且つ車間距離Ｌと予め設定された定常時における目標車間距離Ｌ_U ^* との偏差の絶対値が所定値ΔＬ_S 未満（｜Ｌ_U ^* −Ｌ｜＜ΔＬ_S ）であるという判定条件を満足するか否かによって行う。
【００６９】
そして、一定車間時間で走行中でないと判定されるときにはステップＳ６に移行し、フラグＦ₁ がＦ₁ ＝１であるかどうかを判定する。そして、フラグＦ₁ がＦ₁ ＝１でないときにはステップＳ７に移行し、次式（１２）に基づいて割り込み時の車間距離偏差Ｌ_ERR0を算出する。そして、この割り込み時車間距離偏差Ｌ_ERR0と前記ステップＳ２で算出した相対速度Ｖｒを所定の記憶領域に保存する。そして、ステップＳ８に移行する。フラグＦ₁ がＦ₁ ＝１でないときにはそのままステップＳ８に移行する。
【００７０】
Ｌ_ERR0＝Ｌ−Ｌ₀ ^* ……（１２）
前記ステップＳ８では、前記（１）式で算出される先行車両の車速Ｖｔが、予め設定した前記先行車両が停止したとみなすことの可能なしきい値Ｖ₁ （例えば、１ｋｍ／ｈ程度）を下回るかどうかを判定し、Ｖｔ＜Ｖ₁ であるときには、ステップＳ９に移行する。このステップＳ９では、自車速Ｖｓが、予め設定した自車両が低速走行状態にあるとみなすことの可能なしきい値Ｖ₂ （例えば、１２ｋｍ／ｈ程度）を下回るかどうかを判定する。
【００７１】
そして、Ｖｓ＜Ｖ₂ であるときには、ステップＳ１０に移行してフラグＦ₂ がＦ₂ ＝１であるかどうかを判定し、フラグＦ₂ がＦ₂ ＝１でないときにはステップＳ１１に移行して、前記ステップＳ７で算出した割り込み時車間距離偏差Ｌ_ERR0とステップＳ２で算出した相対速度Ｖｒとに対応するＦ／Ｆゲインζ及びωτを、後述の図７及び図８に示すゲインマップにしたがって設定する。そして、フラグＦをＦ₂ ＝１に設定した後、後述のステップＳ１２に移行する。前記ステップＳ１０でフラグＦ₂ がＦ₂ ＝１であるときにはそのままステップＳ１２に移行する。
【００７２】
一方、前記ステップＳ８で先行車速Ｖｔがしきい値Ｖ₁ を下回らないとき、またステップＳ９で自車速Ｖｓがしきい値Ｖ₂ を下回らないときにはステップＳ１３に移行してフラグＦ₃ がＦ₃ ＝１であるかどうかを判定し、フラグＦ₃ がＦ₃ ＝１でないときにはステップＳ１４に移行し、ステップＳ７で算出した割り込み時車間距離偏差Ｌ_ERR0とステップＳ２で算出した相対速度Ｖｒとに対応するＦ／Ｆゲインζ及びωτを、後述の図７及び図９に示すゲインマップにしたがって設定する。そして、フラグＦ₃ をＦ₃ ＝１に設定した後、ステップＳ１５に移行する。前記ステップＳ１３でフラグＦ₃ がＦ₃ ＝１であるときにはそのままステップＳ１５に移行する。
【００７３】
また、前記ステップＳ５で一定車間時間で走行中であると判定されるときには、ステップＳ１６に移行し、各フラグＦ₁ 〜Ｆ₃ をＦ₁ ＝０、Ｆ₂ ＝０、Ｆ₃ ＝０に設定した後、ステップＳ１７に移行する。
そして、前記ステップＳ１２では、ステップＳ１１の処理で図７及び図８に示すゲインマップから設定したＦ／Ｆゲインζ及びωτと、ステップＳ７で算出した割り込み時車間距離偏差Ｌ_ERR0と、先行車速Ｖｔに基づき前記（１）式で算出される目標車間距離最終値Ｌ₀ ^* とをもとに、前記（２）式にしたがって目標車間距離Ｌ^* を算出する。また、算出した目標車間距離Ｌ^* を微分して目標相対車速Ｖｒ^* を算出する。
【００７４】
前記ステップＳ１５では、ステップＳ１４の処理で図７及び図９に示すゲインマップから設定したＦ／Ｆゲインζ及びωτと、ステップＳ７で算出した割り込み時車間距離偏差Ｌ_ERR0と、先行車速Ｖｔに基づき前記（１）式で算出される目標車間距離最終値Ｌ₀ ^* とをもとに、前記（２）式にしたがって目標車間距離Ｌ^* を算出する。また、算出した目標車間距離Ｌ^* を微分して目標相対車速Ｖｒ^* を算出する。
【００７５】
前記ステップＳ１７では、前記（１）式に基づき目標車間距離最終値Ｌ₀ ^* を算出し、これを目標車間距離Ｌ^* として設定する。また、目標相対車速Ｖｒ^* を零として設定する。
ここで前記図７は、Ｆ／Ｆゲインζを設定するためのゲインマップであって、割り込み時車間距離偏差Ｌ_ERR0と相対速度Ｖｒとに応じて設定される。そして、Ｆ／Ｆゲインζは、割り込み時車間距離偏差Ｌ_ERR0が零から負方向に増加するほど、つまり先行車両と自車両とが近づくほど大きくなる傾向に設定され、また零から正方向に増加するほど、つまり先行車両と自車両とが遠ざかる傾向にあるほど、小さくなる傾向に設定される。また、相対速度Ｖｒが零から負方向に増加し、すなわち自車両と先行車両とが近づくほど小さくなる傾向に設定され、また、相対速度Ｖｒが零から正方向に増加し、すなわち自車両と先行車両とが遠ざかる傾向にあるほど小さくなる傾向に設定される。
【００７６】
また、前記図８及び図９は、Ｆ／Ｆゲインωτを設定するためのゲインマップであって、割り込み時車間距離偏差Ｌ_ERR0と相対速度Ｖｒとに応じて設定される。そして、Ｆ／Ｆゲインωτは、割り込み時車間距離偏差Ｌ_ERR0が零から負方向に増加し、すなわち先行車両と自車両とが近づくほど大きくなる傾向に設定され、また零から正方向に増加するほど、つまり先行車両と自車両とが遠ざかるほど小さくなる傾向に設定される。また、相対速度Ｖｒが零から負方向に増加し、自車両と先行車両とが近づく傾向にあるほど大きくなる傾向に設定され、また、相対速度Ｖｒが零から正方向に増加し、自車両と先行車両とが遠ざかる傾向にあるほど小さくなる傾向に設定される。さらに、前記図８におけるＦ／Ｆゲインωτは、図９の同一条件におけるＦ／Ｆゲインωτよりも大きな値となるように設定されている。
【００７７】
なお、図７、図８、図９においては、割り込み時車間距離偏差Ｌ_ERR0及び相対速度Ｖｒを段階的に複数設定し、この割り込み時車間距離偏差及び相対速度の代表値に対してＦ／Ｆゲインを設定しているため、実際の割り込み時車間距離偏差Ｌ_ERR0及び相対速度Ｖｒに最も近い、割り込み時車間距離偏差及び相対速度の代表値に対応するＦ／Ｆゲインを、実際の割り込み時車間距離偏差Ｌ_ERR0及び相対速度Ｖｒに対応するＦ／Ｆゲインとして設定すればよい。
【００７８】
なお、前記Ｆ／Ｆゲインは段階的に変化させるのではなく、連続的に変化させるようにしてもよい。
また、ゲインマップとして所定の記憶領域に保存するようにした場合について説明しているが、割り込み時車間距離偏差及び相対速度と、Ｆ／Ｆゲインζとの関係、また、割り込み時車間距離偏差及び相対速度と、Ｆ／Ｆゲインωτとの関係を表す関数式として記憶しておき、この関数式に基づいてＦ／Ｆゲインζ及びωτを設定するようにしてもよい。
【００７９】
このようにして、前記ステップＳ１２、Ｓ１５、Ｓ１７において、目標車間距離Ｌ^* 及び目標相対車速Ｖｒ^* が算出されると、ステップＳ２１に移行する。そして、目標車間距離Ｌ^* 及び目標相対車速Ｖｒ^* で走行するための目標加減速度Ｇ_D を算出する。
この目標加減速度Ｇ_D の算出は次のように行う。すなわち、まず、実際の車間距離Ｌから目標車間距離Ｌ^* を減算して車間距離偏差ΔＬ（＝Ｌ−Ｌ^* ）を算出する。そして、相対速度Ｖｒから目標相対車速Ｖｒ^* を減算して相対車速偏差ΔＶｒ（＝Ｖｒ−Ｖｒ^* ）を算出する。
【００８０】
そして、次式（１３）にしたがって目標加減速度Ｇ_D を算出する。
Ｇ_D ＝Ｋ₁ ・ΔＬ＋Ｋ₂ ・ΔＶｒ ……（１３）
なお、式中のＦ₁ 及びＦ₂ は、予め設定された制御ゲインである。
次いで、ステップＳ２２に移行し、ステップＳ２１で算出した目標加減速度Ｇ_D から目標車速Ｖｓ^* を算出する。この目標車速Ｖｓ^* の算出は、例えば、次式（１４）に従って行う。なお、式（１４）中のΔｔは、タイマ割り込み処理におけるサンプリング時間である。また、Ｖｓ^* （ｎ−１）は前回の目標車速Ｖｓ^* である。
【００８１】
Ｖｓ^* （ｎ）＝Ｖｓ^* （ｎ−１）＋Ｇ_D ×Δｔ ……（１４）
なお、算出した目標車速Ｖｓ^* が車速設定装置１５で設定された設定車速Ｖｃよりも大きい場合、また、先行車両を検出していないときには、設定車速Ｖｃを目標車速Ｖｓ^* とする。
次いで、ステップＳ２３に移行し、目標車速Ｖｓ^* に基づいて上述のようにして駆動軸トルク指令値すなわち目標トルクＴｑ^* を算出する。
【００８２】
次いで、ステップＳ２４に移行し、ステップＳ２３で算出した目標トルクＴｑ^* を発生し得るスロットル開度指令値θ^* 及び制動圧指令値Ｐ_B ^* を演算して、これをエンジン出力制御装置９又は制動制御装置８に出力し、制動トルク又は駆動トルクを発生させ、タイマ割り込み処理を終了して所定のメインプログラムに復帰する。
【００８３】
したがって、今、追従走行制御状態で走行車線を走行しているものとし、この状態で自車両の走行車線と同一車線に先行車両を検出することができないときには、図６の処理が実行されたときに、各種センサ等からの検出信号を読み込み（ステップＳ１）、また相対速度Ｖｒを算出するが（ステップＳ２）、先行車両を検出することができないためステップＳ３からＳ４を経てそのままステップＳ２２に移行し、運転者が予め設定した設定車速Ｖｃを目標車速Ｖｓ^* とし、ステップＳ２３に移行して、この目標車速Ｖｓ^* と現在の自車速Ｖｓとの車速偏差ΔＶに基づいて目標トルクＴｑ^* を算出し、これを発生し得るスロットル開度指令値又はブレーキ液圧指令値を算出し、制動制御装置８又はエンジン出力制御装置９を制御して、加減速制御を行う（ステップＳ２４）。
【００８４】
すなわち、目標トルクＴｑ^* が正であるならば加速要求であると判断してエンジン出力制御装置９でスロットル開度を大きくして加速することにより、自車速Ｖｓを目標車速Ｖｓ^* に一致させ、逆に目標トルクＴｑ^* が負であるならば制動制御装置８でディスクブレーキ７で制動力を発生させることにより自車速Ｖｓを目標車速Ｖｓ^* に一致させる。
【００８５】
この先行車両がいない走行状態から、自車両の走行車線に車両が割り込むことによって、先行車両を検出する状態となると、図６において、ステップＳ３からステップＳ５に移行し、一定車間時間で走行中ではないのでステップＳ６に移行するが、フラグＦ₁ はＦ₁ ＝０であるからステップＳ７に移行して、（１２）式に基づいて割り込み時車間距離偏差Ｌ_ERR0を算出する。また、算出した割り込み時車間距離偏差Ｌ_ERR0とステップＳ２で算出した相対速度Ｖｒとを所定の記憶領域に記憶する。
【００８６】
そして、ステップＳ８に移行して、割り込み時車間距離偏差Ｌ_ERR0を算出する際に演算した先行車速Ｖｔが予め設定したしきい値Ｖ₁ よりも小さいかどうかを判定する。
このとき先行車両は割り込み走行しており、しきい値Ｖ₁ を上回る速度で走行しているからステップＳ８からステップＳ１３に移行し、フラグＦ₃ はＦ₃ ＝０であるからステップＳ１４に移行し、前記ステップＳ７で算出した割り込み時車間距離偏差Ｌ_ERR0と相対車速Ｖｒとをもとに、前記図７及び図９のゲインマップに基づいてＦ／Ｆゲインζ及びωτを設定する。そして、フラグＦ₃ をＦ₃ ＝１に設定する。
【００８７】
そして、設定したＦ／Ｆゲインζ及びωτに基づいて目標車間距離Ｌ^* 及び目標相対車速Ｖｒ^* を算出し（ステップＳ１５）、これらに基づいて目標加減速度Ｇ_D を算出し、この目標加減速度Ｇ_D に基づいて目標車速Ｖｓ^* を算出し、この目標車速Ｖｓ^* と自車速Ｖｓとに基づきこれらを一致し得る目標トルクＴｑ^* を算出し、これに基づいて制動制御装置８又はエンジン出力制御装置９を制御することによって、ブレーキ制御又はエンジン制御が行われる（ステップＳ２１〜Ｓ２４）。
【００８８】
そして、先行車両を捕捉し一定車間時間で走行していない状態であり且つ先行車両が停止していない状態では、ステップＳ３、Ｓ５、Ｓ６、Ｓ８、Ｓ１３を経てステップＳ１５に移行し、先行車両が割り込んだ時点の割り込み時車間距離偏差Ｌ_ERR0と相対車速Ｖｒと、ステップＳ１４の処理で設定したＦ／Ｆゲインζ，ωτとに基づいて前記（２）式に基づいて目標車間距離Ｌ^* を算出し、車間距離Ｌが前記目標車間距離Ｌ^* となるように制御が行われる。
【００８９】
ここで、割り込みが行われたときには、先行車両の車速Ｖｔに基づく目標車間距離最終値Ｌ₀ ^* と割り込み時車間距離偏差Ｌ_ERR0に基づく加算量との和からなる目標車間距離Ｌ^* が算出され、この目標車間距離Ｌ^* となるように車間距離制御が行われる。
また、前記割り込み時車間距離偏差Ｌ_ERR0に基づく加算量は、前記（２）式に示すように、割り込み時車間距離偏差Ｌ_ERR0に係数（１−（ａ₀ ／（ｓ² ＋ａ₁ ｓ＋ａ₀ ））を乗算しており、つまり、割り込み時車間距離偏差Ｌ_ERR0を初期値としてフィルタ処理をしていることになるから、割り込み時車間距離偏差Ｌ_ERR0に基づく加算量すなわち前記（２）式の第１項は徐々に零に収束し、よって、目標車間距離Ｌ^* は徐々に目標車間距離最終値Ｌ₀ ^* に収束し最終的に目標車間距離Ｌ^* は目標車間距離最終値Ｌ₀ ^* に収束することになる。
【００９０】
そして、自車両が一定車間時間で走行する状態となると、ステップＳ５からＳ１６を経てステップＳ１７に移行し、目標車間距離最終値Ｌ₀ ^* が目標車間距離Ｌ^* として設定され、また目標相対車速Ｖｒ^* が零に設定され、車間距離が先行車速Ｖｔに基づく目標車間距離Ｌ^* となるように車間距離制御が行われて、一定車間時間走行状態が継続される。
【００９１】
したがって、先行車両が割り込んだ時には、直ちに先行車両の車速Ｖｔに基づく目標車間距離最終値Ｌ₀ ^* となるように制御を行うのではなく、この目標車間距離最終値Ｌ₀ ^* に割り込み時車間距離偏差Ｌ_ERR0に基づく加算量を加算し、自車両の理想的な車両挙動として二次関数で近似した目標車間距離Ｌ^* となるように制御を行っているから、割り込んだ先行車両への追従を開始することに起因して自車両が急減速したり或いは急加速したりすることを回避することができる。
【００９２】
また、このとき、目標車間距離Ｌ^* は目標車間距離最終値Ｌ₀ ^* に収束していくことになるから、割り込み時車間距離偏差Ｌ_ERR0に基づく加算量が目標車間距離最終値Ｌ₀ ^* に加算された状態から緩やかに目標車間距離最終値Ｌ₀ ^* に移行することになり、運転者に違和感を与えることはない。
一方、このように割り込み時車間距離偏差Ｌ_ERR0に基づく加算量を目標車間距離最終値Ｌ₀ ^* に加算して車間距離制御を行っている状態で、先行車両が停車した場合には、先行車両が減速しその先行車速Ｖｔがしきい値Ｖ₁ を下回った時点で、ステップＳ８からステップＳ９に移行する。
【００９３】
このとき、自車速Ｖｓが前記しきい値Ｖ₂ を下回らない状態で走行している間は、ステップＳ９からステップＳ１３を経てステップＳ１５に移行し、引き続き、目標車間距離最終値Ｌ₀ ^* に割り込み時車間距離偏差Ｌ_ERR0に基づく加算量を加算した値が目標車間距離Ｌ^* として設定され、車間距離が、緩やかに目標車間距離最終値Ｌ₀ ^* に移行するように制御が行われる。
【００９４】
この状態から、先行車両の停止に伴って目標車間距離最終値Ｌ₀ ^* が減少し、これに伴って自車両が減速して自車速Ｖｓがしきい値Ｖ₂ を下回ると、ステップＳ９からステップＳ１０に移行する。このとき、フラグＦ₂ はＦ₂ ＝０であるからそのままステップＳ１１に移行し、今度は、図８のゲインマップに基づいて、ステップＳ７の処理で所定の記憶領域に記憶した割り込み時車間距離偏差Ｌ_ERR0と相対車速Ｖｒに対応するＦ／Ｆゲインωτを検索し、フラグＦ₂ をＦ₂ ＝１に設定する。そして、式（２）中のＦ／Ｆゲインωτを、図８のゲインマップから新たに検索したＦ／Ｆゲインωτに変更し、引き続いて上記と同様にして式（２）から目標車間距離Ｌ^* を算出し、上記と同様にして車間距離制御を行う。
【００９５】
ここで、図８は、図９に比較してＦ／Ｆゲインωτの値が大きく設定されているから、このＦ／Ｆゲインωτに基づいて算出される（２）式の第１項は、これまでに比較して速やかに零に収束することになる。
したがって、先行車両が停止するまでの間は、比較的緩やかに目標車間距離最終値Ｌ₀ ^* に収束している状態から、先行車両の停止を検出するとこの時点で速やかに目標車間距離最終値Ｌ₀ ^* に収束することになり、よって、自車両は停止した先行車両に速やかに接近することになる。
【００９６】
つまり、図１０に示すように、先行車両が割り込みを行った時点ｔ₀ で、Ｆ／Ｆゲインωτとして、割り込み時車間距離偏差Ｌ_ERR0とこのときの相対車速Ｖｒとに基づいてωτ_L が設定され（図１０（ｂ））、先行車両が時点ｔ₁ で減速を開始し、時点ｔ₂ で停止すると、時点ｔ₂ でＦ／Ｆゲインωτはωτ_L よりも大きなωτ_H に設定される。
【００９７】
このとき、図１０（ｃ）に示すように、目標車間距離最終値Ｌ₀ ^* は、先行車両の車速Ｖｔに比例して変化する。そして、この目標車間距離最終値Ｌ₀ ^* に、割り込み時車間距離偏差Ｌ_ERR0に基づく加算量が加算された値が目標車間距離Ｌ^* として設定され、この加算量はまずＦ／Ｆゲインωτ_L に応じた割合で徐々に減少するから、目標車間距離Ｌ^* は徐々に目標車間距離最終値Ｌ₀ ^* に収束する。
【００９８】
そして、時点ｔ₂ で先行車両が停止し、Ｆ／Ｆゲインωτが大きな値ωτ_H に変更されると、割り込み時車間距離偏差に基づく加算量の収束割合が大きくなり、目標車間距離Ｌ^* は速やかに目標車間距離最終値Ｌ₀ ^* に収束する。
目標車速Ｖｓ^* は、図１０（ｄ）に示すように、目標車間距離Ｌ^* に応じて変化するから、時点ｔ₂ で先行車両が停止した以後、目標車速Ｖ^* も速やかに零に収束しすなわち自車両は速やかに目標車間距離Ｌ^* の位置に達して停止することになる。
【００９９】
これに対し、図１１に示すように、従来は、時点ｔ₂ で先行車両が停止した場合であっても、Ｆ／Ｆゲインωτは一定値に設定されている（図１１（ｂ））。したがって、図１１（ｃ）に示すように、目標車間距離Ｌ^* は、時点ｔ₂ で先行車両が停止した後も、緩やかに減少することになり、目標車速Ｖｓ^* も緩やかに減少することになって、すなわち停止した先行車両に対して極低速で接近することになる（図１１（ｄ））。
【０１００】
しかしながら、上記第１の実施の形態によれば、図１０に示すように、先行車両が停止した場合には、Ｆ／Ｆゲインωτを大きな値に設定し目標車間距離Ｌ^* を速やかに目標車間距離最終値Ｌ₀ ^* に収束させているから、目標車速Ｖｓ^* も速やかに減少し、停止した先行車両に対して極低速で接近することなく、停止した先行車両に速やかに接近させることができる。
【０１０１】
また、先行車両が遠方にある状態で停止した場合には、目標車速Ｖｓ^* は割り込み時車間距離偏差Ｌ_ERR0が大きくなるほど大きくなりステップＳ９からステップＳ１３に移行することになって、Ｆ／Ｆゲインωτの変更は行わない。したがって、引き続き、緩やかに車間距離制御が行われることになり、遠方で停止した先行車両に対し急速に接近することを回避することができる。
【０１０２】
また、先行車速Ｖｔがしきい値Ｖ₁ を下回ったときに、目標車間距離Ｌ^* を速やかに目標車間距離最終値Ｌ₀ ^* に収束させるようにしているから、先行車速Ｖｔの精度が低い場合であっても、的確に先行車両の停止を検出することができ、目標車間距離Ｌ^* を速やかに目標車間距離最終値Ｌ₀ ^* に収束させることができる。
【０１０３】
また、先行車速Ｖｔがしきい値Ｖ₁ を下回った場合であり且つ、自車速Ｖｓがしきい値Ｖ₂ を下回ったときに、目標車間距離Ｌ^* を速やかに目標車間距離最終値Ｌ₀ ^* に収束させるようにしているから、自車速Ｖｓが大きく自車両を先行車両に急速に接近させたくない状態で、自車両が加速するようなことはない。
また、Ｆ／Ｆゲインωτを変更することにより、目標車間距離Ｌ^* を目標車間距離最終値Ｌ₀ ^* に速やかに収束させることができるから、追従制御装置の構成を大幅に変更することなく容易に実現することができる。
【０１０４】
また、割り込みによる先行車両の変更を検出したときには、割り込み時点における、目標車間距離最終値Ｌ₀ ^* と車間距離Ｌとの偏差である割り込み時車間距離偏差Ｌ_ERR0に基づいて割り込み時の自車両の車両挙動を二次系の伝達関数で近似し、これに基づいて、目標車間距離最終値Ｌ₀ ^* を補正して目標車間距離Ｌ^* を設定するようにしたから、実際の車両挙動を考慮した適切な目標車間距離Ｌ^* を設定することができる。
【０１０５】
また、Ｆ／Ｆゲインζ及びωτを、前記先行車両の割り込みを検出した時点での、目標車間距離最終値Ｌ₀ ^* と車間距離Ｌとの偏差Ｌ_ERR0及び相対車速Ｖｒとに基づいて設定しているから、割り込み時点における自車両と先行車両との相対関係に応じて適切な目標車間距離Ｌ^* を設定することができる。
また、先行車速Ｖｔがしきい値Ｖ₁ を下回るときにＦ／Ｆゲインζ及びωτを変更するかどうかを判定するようにしたから、先行車速Ｖｔを、相対車速Ｖｒと自車速Ｖｓとに基づいて算出して求める場合等のように先行車速Ｖｔの精度が低い場合であっても、先行車両の走行状況を的確に検出し、これに応じてＦ／Ｆゲインζ及びωτを変更することができる。
【０１０６】
ここで、車間距離センサ１２が車間距離検出手段に対応し、車速センサ１３が自車速検出手段に対応し、制動制御装置８及びエンジン出力制御装置９が制駆動力制御手段に対応し、図６のステップＳ３及びＳ５の処理が先行車両変更検出手段に対応し、ステップＳ８の処理で前記（１）式から先行車速Ｖｔを算出する処理が先行車速検出手段に対応し、ステップＳ８の処理で先行車速ＶｔがＶｔ＜Ｖ₁ であるかどうかを判定する処理が先行車両停止検出手段に対応し、ステップＳ１２，Ｓ１５，Ｓ１７の処理が目標車間距離設定手段に対応し、ステップＳ１２，Ｓ１５，Ｓ１７の処理で目標車間距離Ｌ^* を算出する処理が目標車間距離算出手段に対応し、ステップＳ１２及びＳ１５の処理が補正手段及び過渡目標車間距離算出手段に対応し、ステップＳ１２及びＳ１５の処理で目標車間距離最終値Ｌ₀ ^* を算出する処理が目標車間距離最終値算出手段に対応し、ステップＳ２１〜Ｓ２４の処理が制御手段に対応している。
【０１０７】
次に、本発明の第２の実施の形態を説明する。
この第２の実施の形態は、上記第１の実施の形態において、追従制御用コントローラ２０での処理手順が異なること以外は同様であるので、同一部には同一符号を付与し、その詳細な説明は省略する。
すなわち、この第２の実施の形態では、図１２のフローチャートに示すように、前記図６の第１の実施の形態におけるフローチャートにおいて、ステップＳ９の処理に代えてステップＳ９ａの処理を実行している。つまり、ステップＳ８で先行車速Ｖｔがしきい値Ｖ₁ を下回ることを判定したときには、ステップＳ９ａに移行し、今度は、車間距離センサ１２で検出される車間距離Ｌが、しきい値Ｌ₀ を下回るかどうかを判定する。そして、車間距離Ｌがしきい値Ｌ₀ を下回るときにはステップＳ１０、Ｓ１１を経てＳ１２に移行して、比較的大きなＦ／Ｆゲインωτに基づいて目標車間距離Ｌ^* を算出し、車間距離Ｌがしきい値Ｌ₀ を下回らないときには、ステップＳ１３、Ｓ１４を経てＳ１５に移行して、比較的小さなＦ／Ｆゲインωτに基づいて目標車間距離Ｌ^* を算出する。
【０１０８】
したがって、前記しきい値Ｌ₀ を適切に（例えば１４ｍ程度）設定することによって、自車両よりもはるか遠方において先行車両が停止し、車間距離Ｌが大きくすなわち目標車速Ｖ^* が大きい状態でＦ／Ｆゲインωτを大きくすることによりさらに目標車間距離Ｌ^* が大きくなり、目標車速Ｖ^* がより大きな値に制御された状態で停止している先行車両に急接近することを回避することができる。
【０１０９】
なお、上記第１の実施の形態と同等の作用効果を得ることができることはいうまでもない。
次に、本発明の第３の実施の形態を説明する。
この第３の実施の形態は、上記第１の実施の形態と第２の実施の形態とを組み合わせたものである。上記第１の実施の形態において、追従制御用コントローラ２０での処理手順が異なること以外は同様であるので、同一部には同一符号を付与し、その詳細な説明は省略する。
【０１１０】
すなわち、この第３の実施の形態では、図１３のフローチャートに示すように、前記図６に示す第１の実施の形態におけるフローチャートにおいて、ステップＳ９ａの処理を追加している。つまり、ステップＳ９で自車速Ｖｓがしきい値Ｖ₂ を下回ることを検出したときにはステップＳ９ａに移行し、さらに、車間距離Ｌがしきい値Ｌ₀ を下回るかどうかを判定している。そして、車間距離Ｌがしきい値Ｌ₀ を下回るときには、ステップＳ１０、Ｓ１１を経てＳ１２に移行して、比較的大きなＦ／Ｆゲインωτに基づいて目標車間距離Ｌ^* を算出し、車間距離Ｌがしきい値Ｌ₀ を下回らないときには、ステップＳ１３、Ｓ１４を経てＳ１５に移行して、比較的小さなＦ／Ｆゲインωτに基づいて目標車間距離Ｌ^* を算出する。
【０１１１】
したがって、先行車両が停止し、且つ自車速Ｖｓが比較的小さく、且つ車間距離Ｌが短いとき、つまり、停止している先行車両に比較的接近している場合にのみ、Ｆ／Ｆゲインωτを大きく変更するようにしているから、自車速Ｖｓがさらに高速となった状態で停止している先行車両に接近することはなく、また、先行車両が遠方にある状態でＦ／Ｆゲインωτを大きく変更することによって、高速で先行車両に接近することを回避することができる。
【０１１２】
次に、本発明の第４の実施の形態を説明する。
この第４の実施の形態は、車間距離センサ１２及び追従制御用コントローラ２０での処理手順が異なること以外は同様であるので、同一部には同一符号を付与しその詳細な説明は省略する。
この第４の実施の形態における車間距離センサ１２は、いわゆる公知のスキャニング測距器で構成され、レーザ光を例えば中心から左右６°ずつ計１２°程度の角度範囲でスキャンして車両前方へ出力すると共にその反射光を検出し、反射光を捉えるまでの時間に基づき自車両と前方物体との距離をレーザ光のスキャン角度に対応して検出し、これを追従制御用コントローラ２０に出力する。
【０１１３】
一方、追従制御用コントローラ２０は、図１４の機能ブロック図に示すように構成され、車間距離センサ１２のスキャン角度及びこれに対応する車間距離からなる検出信号は車間距離検出部３０に入力され、この車間距離検出部３０では、スキャン角度及び車間距離を、公知の手順によって自車を中心とするＸＹ座標に変換し、自車中心における車間距離Ｌを算出すると共に、前方物体の中心位置を検出する。そして、前回検出時に記憶していた前方物体の中心位置と今回検出時の前方物体の中心位置との偏差Δｙを検出する。また、車間距離Ｌを微分して相対速度Ｖｒを算出する。
【０１１４】
先行車変化検出部３１では、車間距離検出部３０で算出された車間距離Ｌ、相対速度Ｖｒ及び横方向偏差Δｙをもとに、先行車両が切り換わったかどうか、つまり、先行車両が割り込んだか、先行車両に追いついたか、或いは先行車両が車線変更を行ったことによって先行車両が切り換わったかどうかを判定する。この判定は、例えば車間距離Ｌの変化量が所定値以上であるか、或いは相対速度Ｖｒの変化量が所定値以上であるか、横方向偏差Δｙが所定値以上であるかどうか等に基づいて行う。そして、その結果を割込／追いつき時の目標車間距離算出部３４に出力する。
【０１１５】
一方、目標車間距離最終値算出部３３では、車間距離検出部３０で算出された相対速度Ｖｒと車速センサ１３で検出した自車速Ｖｓとをもとに前記（１）式にしたがって目標車間距離最終値Ｌ₀ ^* を算出し、これを前記演算部３２及び追従中の目標車間距離算出部３５に出力する。
前記演算部３２は、車間距離Ｌと目標車間距離最終値Ｌ₀ ^* との偏差Ｌ−Ｌ₀ ^* を算出しこれを前記割込／追いつき時の目標車間距離算出部３４に出力する。この割込／追いつき時の目標車間距離算出部３４は、前記偏差Ｌ−Ｌ₀ ^* と前記相対速度Ｖｒと前記先行車変化検出部３１での判定結果とに基づいて、割込／追いつき時の目標車間距離Ｌ₁ ^* 及び目標相対車速Ｖｒ^* を算出する。具体的には、先行車変化検出部３１で先行車変化を検出したときの、偏差Ｌ−Ｌ₀ ^* 及び相対速度Ｖｒを初期値とし、次式（１５）に基づいて、割込／追いつき時の目標車間距離Ｌ₁ ^* 及び目標相対車速Ｖｒ^* を算出しこれらを車間距離Ｆ／Ｂ制御部３７に出力する。
【０１１６】
Ｌ₁ ^* ＝Ｆ₁ （ｓ）・（Ｌ−Ｌ₀ ^* ） ……（１５）
Ｖｒ^* ＝Ｆ₁ （ｓ）・Ｌ₀ ^*

一方、追従中の目標車間距離算出部３５では、目標車間距離最終値算出部３３で算出される目標車間距離最終値Ｌ₀ ^* に基づいて次式（１６）にしたがって、追従中の目標車間距離Ｌ₂ ^* を算出し、これを演算部３６に出力する。
【０１１７】
Ｌ₂ ^* ＝Ｆ₂ （ｓ）・Ｌ₀ ^* ……（１６）

前記演算部３６では、前記割込／追いつき時の目標車間距離Ｌ₁ ^* と追従中の目標車間距離Ｌ₂ ^* とを加算しこれを目標車間距離Ｌ^* として車間距離Ｆ／Ｂ制御部３７に出力する。
【０１１８】
この車間距離Ｆ／Ｂ制御部３７では、目標相対車速Ｖｒ^* 及び目標車間距離Ｌ^* 、相対車速Ｖｒ及び車間距離Ｌ、自車速Ｖｓをもとに次式（１７）にしたがって、車間距離Ｌを目標車間距離Ｌ^* に応じた値とするための目標車速Ｖｓ^* を算出する。なお、式中のＫ_L 及びＫ_V は、車間距離Ｆ／Ｂゲインである。
Ｖｓ^* ＝Ｋ_L （Ｌ−Ｌ^* ）＋Ｋ_V （Ｖｒ−Ｖｒ^* ）＋Ｖｔ
Ｖｔ＝Ｖｓ＋Ｖｒ ……（１７）
前記車間距離Ｆ／Ｂ制御部３７で算出された目標車速Ｖｓ^* は車速制御部３８に入力され、車速制御部３８では、自車速Ｖｓを目標車速Ｖｓ^* に応じた値とするための駆動軸トルクの指令値Ｔｑ^* を上記第１の実施の形態と同様にして算出する。そして、駆動軸トルク制御部３９では、駆動軸トルクＴｑ^* をもとに上記第１の実施の形態と同様にして制動圧指令値Ｐ_B ^* 又は、スロットル開度指令値θ^* を算出し、これらを、制御対象としての制動制御装置８又はエンジン出力制御装置９に出力する。
【０１１９】
次に、上記第４の実施の形態の動作を、追従制御用コントローラ２０で実行する追従走行制御処理の処理手順を示す図１５のフローチャートを伴って説明する。なお、この場合も追従走行制御処理は例えば１０ｍｓｅｃ毎のタイマ割り込み処理として実行される。また、セットスイッチ１４のスイッチ信号がオフであるとき、また、ブレーキスイッチ１９がオン状態であるときには、追従走行制御処理を行わない。
【０１２０】
前記追従制御用コントローラ２０では、まず、ステップＳ３１で上記第１の実施の形態と同様に、車間距離センサ１２、車速センサ１３の各検出信号、また、セットスイッチ１４のスイッチ信号、車速設定装置１５の設定信号等を読み込み、自車速Ｖｓ、車間距離Ｌを算出する。次いで、ステップＳ３２に移行し、ステップＳ３１で算出した車間距離Ｌを微分して自車両と先行車両との相対車速Ｖｒを算出する。
【０１２１】
次いで、ステップＳ３３に移行して、上記第１の実施の形態と同様にして先行車両を検出したか否かを判定する。そして、先行車両を検出しないときには、ステップＳ３４に移行して、運転者が車速設定装置１５で予め設定した設定車速Ｖｃを目標車速Ｖｓ^* とした後、後述のステップＳ４２に移行する。
一方、ステップＳ３３で先行車両を検出したときにはステップＳ３５に移行し、前記（１）式に基づいて目標車間距離最終値Ｌ₀ ^* を算出する。
【０１２２】
続いて、ステップＳ３６に移行し、先行車両が入れ代わったかどうか、つまり、先行車両が割り込んだか、先行車両に追いついたか、或いは先行車両が車線変更することによって先行車両が切り換わったかどうかを判定する。この判定は、前回先行車両を検出していない状態から今回先行車両を検出する状態となったかどうか、車間距離Ｌの前回値と今回値との差が所定値以上であるかどうか、相対車速Ｖｒの前回値と今回値との差が所定値以上であるかどうか、先行車両との横方向の偏差Δｙの前回値と今回値の差が所定値（例えば車両の横幅相当の２ｍ程度）以上であるかどうか、の何れか一つの条件が成立したときに、先行車両が切り換わったと判定する。なお、各パラメータの前回値は前回処理実行時に所定の記憶領域に記憶しておく。
【０１２３】
そして、ステップＳ３６で先行車両が切り換わったと判定されるときにはステップＳ３７に移行し、ステップＳ３６で先行車両が切り換わったと判定した時点における車間距離Ｌと目標車間距離最終値Ｌ₀ ^* との偏差Ｌ−Ｌ₀ ^* 及び相対車速Ｖｒ₀ を、前記（１５）式に示す二次フィルタＦ₁ （ｓ）の初期値として更新設定した後ステップＳ３８に移行する。一方、ステップＳ３６で先行車両が切り換わっていないと判定したときには、そのままステップＳ３８に移行する。
【０１２４】
このステップＳ３８では、前記（１５）式にしたがって、割込／追いつき時の目標車間距離Ｌ₁ ^* 及び目標相対車速Ｖｒ^* を算出し、続いてステップＳ３９に移行して、前記（１６）式にしたがって追従時の目標車間距離Ｌ₂ ^* を算出する。次いで、ステップＳ４０に移行し、割込／追いつき時の目標車間距離Ｌ₁ ^* 及び追従時の目標車間距離Ｌ₂ ^* の和から目標車間距離Ｌ^* を算出する。
【０１２５】
次いで、ステップＳ４１に移行し、前記（１７）式にしたがって、目標車速Ｖｓ^* を算出した後、ステップＳ４２に移行する。なお、このとき、前記（１７）式から算出される目標車速Ｖｓ^* が、車速設定装置１５で運転車が予め設定した設定車速Ｖｃを越えるときには、この設定車速Ｖｃを目標車速Ｖｓ^* として設定する。
【０１２６】
前記ステップＳ４２では、上記第１の実施の形態と同様にして、目標車速Ｖｓ^* から自車速Ｖｓを減算した値に制御ゲインを乗算し、これから走行抵抗を減算し、これを目標トルクＴｑ^* とする。
次いで、ステップＳ４３に移行し、ステップＳ４２で算出した目標トルクＴｑ^* を発生し得るスロットル開度指令値θ^* 及び制動圧指令値Ｐ_B ^* を演算して、これをエンジン出力制御装置９又は制動制御装置８に出力し、制動トルク又は駆動トルクを発生させ、タイマ割り込み処理を終了して所定のメインプログラムに復帰する。
【０１２７】
したがって、今、追従走行制御状態で走行車線を走行しているものとし、この状態で自車両の走行車線と同一車線に先行車両を検出することができないときには、図１５の処理が実行されたときに、各種センサ等からの検出信号を読み込み（ステップＳ３１）、また相対速度Ｖｒを算出する（ステップＳ３２）が、先行車両を検出することができないため、ステップＳ３３からステップＳ３４に移行し、運転者が予め車速設定装置１５で設定した設定車速Ｖｃを目標車速Ｖｓ^* とし、ステップＳ４２に移行して、上記第１の実施の形態と同様にして目標車速Ｖｓ^* と現在の自車速Ｖｓとの車速偏差ΔＶに基づいて目標トルクＴｑ^* を算出し、これを発生し得るスロットル開度指令値θ^* 又は制動圧指令値Ｐｂ^* を算出し、制動制御装置８又はエンジン出力制御装置９を制御して、加減速制御を行う（ステップＳ４３）。
【０１２８】
この先行車両がいない走行状態から、自車両が自車両の走行車線の遠くの先行車両に追いつくことによって、先行車両を検出する状態となると、図１５において、ステップＳ３３からステップＳ３５に移行し、前記（１）式から目標車間距離最終値Ｌ₀ ^* を算出し、先行車両が入れ替わったかどうかを検出する（ステップＳ３６）。この場合、先行車両に追いつき、車両が検出されていない状態から検出されている状態に変化したから、先行車両が入れ替わったことが検出され、ステップＳ３７に移行して、この時点における、目標車間距離最終値Ｌ₀ ^* と実際の目標車間距離Ｌとの偏差Ｌ−Ｌ₀ ^* が算出され、これが割込／追いつき時の目標車間距離Ｌ₁ ^* のフィルタ演算における初期値として設定される。また、この時点における相対車速Ｖｒが目標相対車速Ｖｒ^* のフィルタ演算における初期値として設定される。
【０１２９】
そして、設定された初期値に基づいて前記（１５）式に基づいてフィルタ演算が行われて、割込／追いつき時の目標車間距離Ｌ₁ ^* 及び目標相対車速Ｖｒ^* が算出され（ステップＳ３８）、さらに、前記（１６）式に基づいて追従時の目標車間距離Ｌ₂ ^* を算出し（ステップＳ３９）、これらを加算して目標車間距離Ｌ^* を算出する（ステップＳ４０）。
【０１３０】
そして、この目標車間距離Ｌ^* と、フィルタ演算で算出される目標相対車速Ｖｒ^* と、実際の車間距離Ｌ及び相対車速Ｖｒ、また先行車速Ｖｔに基づいて前記（１７）式から目標車速Ｖｓ^* を算出し（ステップＳ４１）、この目標車速Ｖｓ^* と自車速Ｖｓとに基づきこれらを一致し得る目標トルクＴｑ^* を算出し、これに基づいて制動制御装置８又はエンジン出力制御装置９を制御することによって、ブレーキ制御又はエンジン制御が行われる（ステップＳ４２，Ｓ４３）。
【０１３１】
そして、先行車両を捕捉し、先行車両を検出し先行車両の入れ代わりが行われない状態では、ステップＳ３３，Ｓ３５，Ｓ３６，Ｓ３８〜４３の処理を繰り返し行い、割り込みがあった時点における目標車間距離最終値Ｌ₀ ^* とこの時の実際の車間距離Ｌとの偏差Ｌ−Ｌ₀ ^* を初期値とするフィルタ演算により算出される割込／追いつき時の目標車間距離Ｌ₁ ^* と追従時の目標車間距離Ｌ₂ ^* との和から算出された目標車間距離Ｌ^* と、実際の車間距離Ｌと、が一致するように、且つ、割り込みがあった時点の相対車速Ｖｒを初期値とするフィルタ演算により算出される目標相対車速Ｖｒ^* と実際の相対車速Ｖｒとが一致するように制御が行われる。
【０１３２】
ここで、先行車両を捕捉する状態となった時点からの前記（１５）式に基づいて算出される割込／追いつき時の目標車間距離Ｌ₁ ^* は、例えば図１６（ａ）に示すように、車間距離と目標車間距離最終値との偏差Ｌ−Ｌ₀ ^* は正値であるから、二次遅れで正値から負値に緩やかに移行した後、零に収束することになる。同様に、目標相対車速Ｖｒ^* は、図１６（ｂ）に示すように、自車両が先行車両よりも速度が速く、相対車速Ｖｒが負値であるから、負値から正値に緩やかに移行した後、零に収束することになる。
【０１３３】
一方、追従時の目標車間距離Ｌ₂ ^* は、先行車速Ｖｔに基づいて前記（１６）式にしたがって算出されるから、図１６（ｃ）に示すように、目標車間距離最終値Ｌ₀ ^* の変化に応じて一時遅れで変化することになる。
したがって、これ目標車間距離Ｌ₁ ^* 及びＬ₂ ^* の和から算出される目標車間距離Ｌ^* は、例えば図１７（ｂ）に示すように、先行車両を検出していない状態から時点ｔ₁₁で先行車両を捕捉する状態となり、このとき先行車両が定速走行をしている状態では、割込／追いつき時の目標車間距離Ｌ₁ ^* は、割り込み時の車間距離Ｌと割り込み時の目標車間距離最終値Ｌ₀ ^* との偏差Ｌ−Ｌ₀ ^* を初期値として、前記図１６（ａ）に示すように緩やかに減少するが、先行車両は割り込み後一定車速で走行しているから、追従時の目標車間距離Ｌ₂ ^* は、先行車速Ｖｔに応じた一定値となる。よって、目標車間距離Ｌ^* は、図１７（ａ）に示すように、割り込み時の目標車間距離Ｌ^* から緩やかに減少し、やがて追従時の目標車間距離Ｌ₂ ^* に収束する（時点ｔ₁₂）。
【０１３４】
一方、目標相対車速Ｖｒ^* は、時点ｔ₁₁で先行車両を捕捉する状態となった時点の相対車速Ｖｒを初期値として、前記図１６（ｂ）に示すように緩やかに減少する。そして、このようにして設定された、目標車間距離Ｌ^* 及び目標相対車速Ｖｒ^* と実際の車間距離Ｌ及び相対車速Ｖｒとが一致するように目標トルクＴｑ^* が設定されてこれに応じた制駆動力が発生する。したがって、先行車両との車間距離は、緩やかに目標車間距離最終値Ｌ₀ ^* に収束することになる。
【０１３５】
そして、この状態から時点ｔ₁₃で先行車速Ｖｔが減速すると、割込／追いつき時の目標車間距離Ｌ₁ ^* は零に収束しているから、目標車間距離Ｌ^* は追従時の目標車間距離Ｌ₂ ^* によって決定される。このとき、追従時の目標車間距離Ｌ₂ ^* は目標車間距離最終値Ｌ₀ ^* つまり先行車速Ｖｔの減少に応じて一次遅れで減少し、時点ｔ₁₄で先行車速Ｖｔが一定となると、追従時の目標車間距離Ｌ₂ ^* も速やかに一定値に収束することになる。また、このとき、目標相対車速Ｖｒ^* は零に収束しているから、相対車速Ｖｒが零となるように制御が行われることになり、車間距離は速やかに目標車間距離最終値Ｌ₀ ^* に収束することになる。
【０１３６】
また、例えば時点ｔ₁₁で先行車両を捕捉する状態となり、時点ｔ₁₂で割込／追いつき時の目標車間距離Ｌ₁ ^* が零に収束する前に、先行車速Ｖｔが減速或いは停止すると、追従時の目標車間距離Ｌ₂ ^* は先行車速Ｖｔの変化に対して一次遅れで変化し割込／追いつき時の目標車間距離Ｌ₁ ^* の応答よりも速やかに減速後の先行車速Ｖｔに応じた目標車間距離最終値Ｌ₀ ^* に収束するから、目標車間距離Ｌ₀ は速やかに減少し、減速後の先行車速Ｖｔに応じた目標車間距離最終値Ｌ₀ ^* に速やかに収束することになるが、目標相対車速Ｖｒ^* が零に収束していない状態では、相対車速Ｖｒが目標相対車速Ｖｒ^* となるように車速制御が行われるから、急加減速することはない。
【０１３７】
このように、先行車両が切り替わったときには、切り替わり時点における偏差Ｌ−Ｌ₀ ^* に基づく割込／追いつき時の目標車間距離Ｌ₁ ^* によって目標車間距離Ｌ₀ を緩やかに目標車間距離最終値Ｌ₀ ^* に収束させることができるから、切り替わった後の先行車両に追従することに起因して自車両が急減速したり或いは急加速したりすることを回避することができる。また、先行車速Ｖｔが変化したときには、追従時の目標車間距離Ｌ₂ ^* によって目標車間距離Ｌ₀ を、割込／追いつき時の目標車間距離Ｌ₁ ^* の応答特性よりも比較的速やかに応答させ、変化後の先行車速Ｖｔに応じた目標車間距離最終値Ｌ₀ ^* に追従させることができるから、割り込み或いは追いつき等によって車間距離Ｌが緩やかに目標車間距離最終値Ｌ₀ ^* に収束している状態であっても先行車速Ｖｔの変化に対して速やかに応答することができる。したがって、先行車両の走行状態に応じて、運転者の期待する車間距離Ｌを確保することができ、運転者に違和感を与えることなく先行車両に追従することができる。
【０１３８】
また、目標車間距離Ｌ^* を割込／追いつき時の目標車間距離Ｌ₁ ^* と追従時の目標車間距離Ｌ₂ ^* との和によって算出しているから割り込み或いは追いつき等の先行車両が変化したときと、追従時とで、制御定数を切り換える必要はなく、このため、不連続感を与えることなく制御を行うことができる。
また、目標車間距離Ｌ^* を割込／追いつき時の目標車間距離Ｌ₁ ^* と追従時の目標車間距離Ｌ₂ ^* との和から算出しているから、先行車両に遠くから追いつきつつ先行車両が減速するというような複合条件においても、運転者の期待値通りの目標車間距離を算出することができ、運転者に違和感を与えることはない。
【０１３９】
ここで、車間距離センサ１２が車間距離検出手段に対応し、車速センサ１３が自車速検出手段に対応し、制動制御装置８及びエンジン出力制御装置９が制駆動力制御手段に対応し、図１５のステップＳ３３の処理が先行車両有無検出手段に対応し、ステップＳ３４，Ｓ４１〜Ｓ４３の処理が制御手段に対応し、ステップＳ３５の処理で前記（１）式から先行車速Ｖｔを算出する処理が先行車速検出手段に対応し、ステップＳ３５の処理で目標車間距離最終値Ｌ₀ ^* を算出する処理が目標車間距離最終値算出手段に対応し、ステップＳ３６の処理が先行車両変更検出手段に対応し、ステップＳ３６の処理で横方向偏差Δｙを算出する処理が横方向距離検出手段に対応し、ステップＳ３８の処理で割込／追いつき時の目標車間距離Ｌ₁ ^* を算出する処理が目標車間距離過渡値算出手段に対応し、ステップＳ４０の処理が目標車間距離算出手段に対応している。
【０１４０】
次に、本発明の第５の実施の形態を説明する。
この第５の実施の形態は、上記第１の実施の形態において、追従制御用コントローラ２０での処理手順が異なること以外は同様であるので、同一部には同一符号を付与し、その詳細な説明は省略する。
図１８は、第５の実施の形態における追従制御用コントローラ２０の機能ブロック図であって、図１８のブロック図に示すように、自車両と先行車両との間の車間距離Ｌは車間距離センサ１２で計測され、車間距離検出部４１に入力されて車間距離Ｌが算出されると共に、この車間距離Ｌが微分されて相対速度Ｖｒが算出される。そして、車間距離Ｌ及び相対速度Ｖｒは目標車間距離及び目標相対車速算出部４２と車間距離Ｆ／Ｂ制御部４３とに入力される。
【０１４１】
前記目標車間距離及び目標相対車速算出部４２では、前記相対速度Ｖｒ、車速センサ１３で検出した自車速Ｖｓ、車間距離センサ１２で検出した車間距離Ｌをもとに、後述の手順にしたがって目標車間距離Ｌ及び目標相対車速Ｖｒ^* を算出する。そして、これらを前記車間距離Ｆ／Ｂ制御演算部４３に出力する。
前記車間距離Ｆ／Ｂ制御部４３は、前記目標車間距離Ｌ^* 及び目標相対車速Ｖｒ^* と、前記車間距離検出部４１からの相対車速Ｖｒ及び車間距離Ｌと、自車速Ｖｓとを入力し、これらをもとに、車間距離Ｌを目標車間距離Ｌ^* に応じた値とするための目標車速Ｖｓ^* を算出する。
【０１４２】
この目標車速Ｖｓ^* は車速制御部４４に入力され、車速制御部４４では、上記第１の実施の形態と同様にして自車速Ｖｓを目標車速Ｖｓ^* に応じた値とするための駆動軸トルクの指令値Ｔｑ^* を算出する。
この駆動軸トルク指令値Ｔｑ^* をもとに、駆動軸トルク制御部４５では、上記第１の実施の形態と同様にして駆動目標制動圧Ｐ_B ^* 又は、スロットル開度指令値θ^* を算出し、これらを、制御対象としての制動制御装置８又はエンジン出力制御装置９に、制動圧指令値Ｐ_B ^* 又はスロットル開度指令値θ^* として出力する。
【０１４３】
図１９は、前記目標車間距離及び目標相対車速算出部４２の詳細を表すブロック図であって、目標車間距離及び目標相対車速算出部４２は、自車速Ｖｓと相対車速Ｖｒとから先行車両の加減速度αを算出する先行車加減速度算出部４２ａと、先行車加減速度αをもとに先行車が減速したかどうかを判定する先行車減速判断部４２ｂと、自車速Ｖｓ、相対車速Ｖｒ、車間距離Ｌ、目標車間距離最終値Ｌ₀ ^* と、前記先行車減速判断部４２ｂの判断結果をもとに、後述のωτ及びζからなるＦ／Ｆゲインを決定するＦ／Ｆゲイン算出部４２ｃと、自車速Ｖｓ、相対車速Ｖｒ、車間距離Ｌ、目標車間距離最終値Ｌ₀ ^* と、前記Ｆ／Ｆゲイン算出部４２ｃからのＦ／Ｆゲインωτ及びζをもとに、上記第４の実施の形態と同様にして前記（１５）式に基づいて、先行車の入れ替わりが発生したときの車間距離偏差Ｌ−Ｌ₀ ^* 及び相対速度Ｖｒを初期値として、前記図１６に示すようにゆっくりと零に収束するような割込／追いつき時の目標車間距離Ｌ₁ ^* 及び目標相対車速Ｖｒ^* を算出する目標車間距離及び目標相対車速演算部４２ｄとから構成されている。
【０１４４】
前記先行車加減速度算出部４２ａでは、自車速Ｖｓ及び相対速度Ｖｒから先行車速Ｖｔを算出し、次式（１８）に基づいて、先行車加減速度αを算出する。

Ｖｔ＝Ｖｓ＋Ｖｒ
前記Ｆ／Ｆゲイン算出部４２ｃでは、自車速Ｖｓ、相対車速Ｖｒ、車間距離Ｌ、前記（１）式と同様にして算出される目標車間距離最終値Ｌ₀ ^* と、前記先行車減速判断部４２ｂの判断結果をもとに、割込／追いつき時の目標車間距離Ｌ₁ ^* 及び目標相対車速Ｖｒ^* を算出するための前記式（１５）中のζ及びωτであるＦ／Ｆゲインを設定する。すなわち、前記前記先行車減速判断部４２ｂにおいて、先行車両の入れ替わりが発生したときの目標車間距離最終値Ｌ₀ ^* と車間距離Ｌとの偏差Ｌ−Ｌ₀ ^* （＝Ｌ_ERR0）に該当するＦ／Ｆゲインζ及びωτを、例えば前記図７，図９及び図２０に基づいて算出する。なお、Ｆ／Ｆゲインζ及びωτは、前記図７，図９及び図２０に限るものではなく、任意に設定することができる。
【０１４５】
前記図２０は、前記図７と同様に、Ｆ／Ｆゲインωτを設定するためのゲインマップであって、車間距離偏差Ｌ_ERR0と相対速度Ｖｒとに応じて設定される。そして、Ｆ／Ｆゲインωは、車間距離偏差Ｌ_ERR0が零から負方向に増加し、すなわち先行車両と自車両とが近づくほど大きくなる傾向に設定され、また零から正方向に増加するほど、つまり先行車両と自車両とが遠ざかるほど小さくなる傾向に設定される。また、相対速度Ｖｒが零から負方向に増加し、自車両と先行車両とが近づく傾向にあるほど大きくなる傾向に設定され、また、相対速度Ｖｒが零から正方向に増加し、自車両と先行車両とが遠ざかる傾向にあるほど小さくなる傾向に設定される。さらに、この図２０におけるＦ／Ｆゲインωτは、前記図９の同一条件におけるＦ／Ｆゲインωτよりも大きな値となるように設定されている。
【０１４６】
なお、この図２０においても、車間距離偏差Ｌ_ERR0及び相対速度Ｖｒを段階的に複数設定し、この車間距離偏差及び相対速度の代表値に対してＦ／Ｆゲインを設定しているため、実際の車間距離偏差Ｌ_ERR0及び相対速度Ｖｒに最も近い、車間距離偏差及び相対速度の代表値に対応するＦ／Ｆゲインを、実際の車間距離偏差Ｌ_ERR0及び相対速度Ｖｒに対応するＦ／Ｆゲインとして設定すればよい。
【０１４７】
なお、前記Ｆ／Ｆゲインは段階的に変化させるのではなく、連続的に変化させるようにしてもよい。
また、ゲインマップとして所定の記憶領域に保存するようにした場合について説明しているが、車間距離偏差及び相対速度と、Ｆ／Ｆゲインζとの関係、また、車間距離偏差及び相対速度と、Ｆ／Ｆゲインωτとの関係を表す関数式として記憶しておき、この関数式に基づいてＦ／Ｆゲインζ及びωτを設定するようにしてもよい。
【０１４８】
前記目標車間距離目標相対車速演算部４２ｄでは、Ｆ／Ｆゲインζ，ωτ、自車速Ｖｓ、相対車速Ｖｒ、車間距離Ｌ、目標車間距離最終値Ｌ₀ ^* をもとに、上記第４の実施の形態と同様にして前記（１５）式に基づいて、割込／追いつき時の目標車間距離Ｌ₁ ^* 及び目標相対車速Ｖｒ^* を算出し、割込／追いつき時の目標車間距離Ｌ₁ ^* と目標車間距離最終値Ｌ₀ ^* との和から次式（１９）にしたがって、目標車間距離Ｌ^* を算出する。
【０１４９】
Ｌ^* ＝Ｌ₀ ^* ＋Ｌ₁ ^* ……（１９）
そして、この目標車間距離Ｌ^* と目標相対車速Ｖｒ^* と、車間距離Ｌ及び相対車速Ｖｒとをもとに前記（１７）式にしたがって、目標車速Ｖｓ^* を算出する。次に、上記第５の実施の形態の動作を、追従制御用コントローラ２０で実行する追従走行制御処理の処理手順を示す図２１のフローチャートを伴って説明する。なお、この場合も追従走行制御処理は例えば１０ｍｓｅｃ毎のタイマ割り込み処理として実行される。また、セットスイッチ１４のスイッチ信号がオフであるとき、また、ブレーキスイッチ１９がオン状態、つまりブレーキペダル８ａが踏み込まれていると判定されるときには行わない。また、処理中で使用されるフラグＦ₁ 〜Ｆ₃ は起動時には初期値として零に設定されている。
【０１５０】
前記追従制御用コントローラ２０では、まず、ステップＳ５１で上記第１の実施の形態と同様に、車間距離センサ１２、車速センサ１３の各検出信号、また、セットスイッチ１４のスイッチ信号、車速設定装置１５の設定信号等を読み込み、自車速Ｖｓ、車間距離Ｌを算出する。次いで、ステップＳ５２に移行し、ステップＳ５１で算出した車間距離Ｌを微分して自車両と先行車両との相対車速Ｖｒを算出する。
【０１５１】
次いで、ステップＳ５３に移行して、上記第１の実施の形態と同様にして先行車両を検出したか否かを判定する。そして、先行車両を検出しないときには、ステップＳ５４に移行して、フラグＦ₁ 及びＦ₂ 及びＦ₃ をＦ₁ ＝０、Ｆ₂ ＝０、Ｆ₃ ＝０に設定した後、後述のステップＳ７２に移行する。一方、先行車があるときにはステップＳ５５に移行する。
【０１５２】
このステップＳ５５では、上記第１の実施の形態と同様にして一定車間時間で走行中であるかどうかを判定し、一定車間時間で走行中でないと判定されるときにはステップＳ５６に移行し、フラグＦ₁ がＦ₁ ＝１でないと判定されるときにはステップＳ５７に移行し、車間距離Ｌと目標車間距離最終値Ｌ₀ ^* とから車間距離偏差Ｌ_ERR0を算出する。そして、この車間距離偏差Ｌ_ERR0と前記ステップＳ５２で算出した相対速度Ｖｒを所定の記憶領域に保存した後ステップＳ５８に移行する。前記ステップＳ５６で、フラグＦ₁ がＦ₁ ＝１でないときにはそのままステップＳ５８に移行する。
【０１５３】
このステップＳ５８では、前記（１８）式に基づいて先行車加減速度αを算出し、続いてステップＳ５９に移行して、先行車加減速度αが、先行車が急減速しているとみなすことの可能なしきい値α₁ （例えば−１．０ｍ／ｓ² 程度）を下回ると判定されるときには、ステップＳ６０に移行し、フラグＦ₂ がＦ₂ ＝１であるかどうかを判定する。そして、フラグＦ₂ がＦ₂ ＝１でないときにはステップＳ６１に移行して、前記ステップＳ５７で算出した車間距離偏差Ｌ_ERR0とステップＳ５２で算出した相対速度Ｖｒとに対応するＦ／Ｆゲインζ及びωτを、例えば前記図７及び図２０に示すゲインマップにしたがって設定する。そして、フラグＦをＦ₂ ＝１に設定した後、後述のステップＳ６２に移行する。前記ステップＳ６０でフラグＦ₂ がＦ₂ ＝１であるときにはそのままステップＳ６２に移行する。
【０１５４】
一方、前記ステップＳ５９で先行車加減速度αがしきい値α₁ を下回らないと判定されるときにはステップＳ６３に移行してフラグＦ₃ がＦ₃ ＝１であるかどうかを判定し、フラグＦ₃ がＦ₃ ＝１でないときにはステップＳ６４に移行し、ステップＳ５７で算出した車間距離偏差Ｌ_ERR0とステップＳ２で算出した相対速度Ｖｒとに対応するＦ／Ｆゲインζ及びωτを、例えば前記図７及び図９に示すゲインマップにしたがって設定する。そして、フラグＦ₃ をＦ₃ ＝１に設定した後、ステップＳ６５に移行する。前記ステップＳ６３でフラグＦ₃ がＦ₃ ＝１であるときにはそのままステップＳ６５に移行する。
【０１５５】
また、前記ステップＳ５５で一定車間時間で走行中であると判定されるときには、ステップＳ６６に移行し、各フラグＦ₁ 〜Ｆ₃ をＦ₁ ＝０、Ｆ₂ ＝０、Ｆ₃ ＝０に設定した後、ステップＳ６７に移行する。
そして、前記ステップＳ６２では、ステップＳ６１の処理で図７及び図２０に示すゲインマップから設定したＦ／Ｆゲインζ及びωτと、ステップＳ５７で算出した車間距離偏差Ｌ_ERR0と、先行車速Ｖｔに基づき前記（２）式で算出される目標車間距離最終値Ｌ₀ ^* とをもとに、前記（１５）及び（１９）式にしたがって目標車間距離Ｌ^* 及び目標相対車速Ｖｒ^* を算出する。
【０１５６】
前記ステップＳ６５では、ステップＳ６４の処理で図７及び図９に示すゲインマップから設定したＦ／Ｆゲインζ及びωτと、ステップＳ５７で算出した車間距離偏差Ｌ_ERR0と、先行車速Ｖｔに基づき前記（１）式で算出される目標車間距離最終値Ｌ₀ ^* とをもとに、前記（１５）及び（１９）式にしたがって目標車間距離Ｌ^* 及び目標相対車速Ｖｒ^* を算出する。
【０１５７】
前記ステップＳ６７では、前記（１）式に基づき目標車間距離最終値Ｌ₀ ^* を算出し、これを目標車間距離Ｌ^* として設定する。また、目標相対車速Ｖｒ^* を零として設定する。
このようにして、前記ステップＳ６２、Ｓ６５、Ｓ６７において、目標車間距離Ｌ^* 及び目標相対車速Ｖｒ^* が算出されると、ステップＳ７２に移行する。そして、前記（１７）式にしたがって、目標車速Ｖｓ^* を算出する。
【０１５８】
なお、算出した目標車速Ｖｓ^* が車速設定装置１５で設定された設定車速Ｖｃよりも大きい場合には、設定車速Ｖｃを目標車速Ｖｓ^* とする。
次いで、ステップＳ７３に移行し、目標車速Ｖｓ^* に基づいて上述のようにして目標トルクＴｑ^* を算出し、次いで、ステップＳ７４に移行して、ステップＳ７３で算出した目標トルクＴｑ^* を発生し得るスロットル開度指令値θ^* 及び制動圧指令値Ｐ_B ^* を演算してこれをエンジン出力制御装置９又は制動制御装置８に出力し、制動トルク又は駆動トルクを発生させ、タイマ割り込み処理を終了して所定のメインプログラムに復帰する。
【０１５９】
したがって、今、追従走行制御状態で走行車線を走行しているものとし、この状態で自車両の走行車線と同一車線に先行車両を検出することができないときには、図２１の処理が実行されたときに、各種センサ等からの検出信号を読み込み（ステップＳ５１）、また相対速度Ｖｒを算出する（ステップＳ５２）が、先行車両を検出することができないため、ステップＳ５３からステップＳ５４を経てＳ５５に移行し、運転者が予め車速設定装置１５で設定した設定車速Ｖｃを目標車速Ｖｓ^* とし、ステップＳ７２に移行して、上記第１の実施の形態と同様にして目標車速Ｖｓ^* と現在の自車速Ｖｓとの車速偏差ΔＶに基づいて目標トルクＴｑ^* を算出し、これを発生し得るスロットル開度指令値θ^* 又は制動圧指令値Ｐｂ^* を算出し、制動制御装置８又はエンジン出力制御装置９を制御して、加減速制御を行う（ステップＳ７３，Ｓ７４）。
【０１６０】
この先行車両がいない走行状態から、自車両が自車両の走行車線の遠くの先行車両に追いつくことによって、先行車両を検出する状態となると、図２１において、ステップＳ５３からステップＳ５５に移行し、前記（１）式から目標車間距離最終値Ｌ₀ ^* を算出し、一定車間時間で走行中であるかつまり、先行車両が切り替わったかどうかを検出する。この場合、先行車両に追いついたため一定車間時間で走行中でないから、ステップＳ５５からＳ５６を経てステップＳ５７に移行し、この時点における目標車間距離最終値Ｌ₀ ^* と車間距離Ｌとの偏差である車間距離偏差Ｌ_ERR0を算出し、さらに、前記（１８）式にしたがって先行車両の加減速度αを算出する（ステップＳ５８）。
【０１６１】
このとき、先行車両が減速していないときには、先行車加減速度αがしきい値α₁ よりも大きいからステップＳ５９からステップＳ６３を経てステップＳ６４に移行し、ステップＳ５７で算出した車間距離偏差Ｌ_ERR0とステップＳ５２で算出した相対速度Ｖｒとをもとに、前記図７及び図９から該当するＦ／Ｆゲインζ及びωτを検出する。そして、このＦ／Ｆゲインζ及びωτを、前記（１５）式に当てはめ、先行車両の入れ替わりを検出した時点での車間距離偏差Ｌ_ERR0を割込／追いつき時の目標車間距離Ｌ₁ ^* のフィルタ演算における初期値として割込／追いつき時の目標車間距離Ｌ₁ ^* を算出し、これと目標車間距離最終値Ｌ₀ ^* とから前記（１９）式にしたがって目標車間距離Ｌ^* を算出する。
【０１６２】
そして、この目標車間距離Ｌ^* と、フィルタ演算で算出される目標相対車速Ｖｒ^* と、実際の車間距離Ｌ及び相対車速Ｖｒ、また先行車速Ｖｔに基づいて前記（１７）式から目標車速Ｖｓ^* を算出し（ステップＳ７２）、この目標車速Ｖｓ^* と自車速Ｖｓとに基づきこれらを一致し得る目標トルクＴｑ^* を算出し、これに基づいて制動制御装置８又はエンジン出力制御装置９を制御することによって、ブレーキ制御又はエンジン制御を行う（ステップＳ７３，Ｓ７４）。
【０１６３】
そして、先行車両を捕捉し、先行車両を検出し先行車両の入れ替わりが行われずまた先行車両が減速をしない状態では、ステップＳ５３，Ｓ５５，Ｓ５６，Ｓ５８，Ｓ５９，Ｓ６３，Ｓ６５，Ｓ７２〜Ｓ７４の処理を繰り返し行い、割り込みがあった時点における目標車間距離最終値Ｌ₀ ^* とこの時の実際の車間距離Ｌとの偏差Ｌ−Ｌ₀ ^* を初期値とするフィルタ演算により算出される割込／追いつき時の目標車間距離Ｌ₁ ^* との和から算出された目標車間距離Ｌ^* と、実際の車間距離Ｌと、が一致するように、且つ、割り込みがあった時点の相対車速Ｖｒを初期値とするフィルタ演算により算出される目標相対車速Ｖｒ^* と実際の相対車速Ｖｒとが一致するように制御が行われる。
【０１６４】
したがって、図２２（ｂ）に示すように定速走行している先行車両に、時点ｔ₂₁で追いついたときには、この追いついた時点における目標車間距離最終値Ｌ₀ ^* と車間距離Ｌとの偏差に基づき算出された割込／追いつき時の目標車間距離Ｌ₁ ^* は前記図１６（ａ）に示すように徐々に零に収束するから目標車間距離Ｌ^* は、図２２（ａ）に示すように、緩やかに目標車間距離最終値Ｌ₀ ^* に収束することになり、また、図１６（ｂ）に示すように、目標相対車速Ｖｒ^* も緩やかに零に収束するから、自車両は急な加減速を伴うことなく緩やかに先行車両に追いつくことになる。
【０１６５】
そして、時点ｔ₂₂で自車両が先行車両に追いつき所定の車間距離を保った状態での走行状態となると、ステップＳ５５からステップＳ６６に移行して、先行車両の車速Ｖｔに応じた目標車間距離最終値Ｌ₀ ^* を目標車間距離Ｌ^* とする一定車間時間での走行状態に移行する。
そして、この一定車間時間での走行状態から、時点ｔ₂₃で先行車両が減速し、ステップＳ５５からＳ５６を経てステップＳ５８に移行し、ここで算出される先行車両の加減速度αがしきい値α₁ よりも小さくなると、ステップＳ５９からステップＳ６０に移行し、先行車両が切り替わった時点における車間距離偏差Ｌ_ERR0を初期値とするフィルタ処理演算における前記（１５）式のＦ／Ｆゲインζ及びωτを、所定の記憶領域に記憶していた入れ替わり時のＬ_ERR0及び相対速度Ｖｒをもとに前記図７及び図２０から特定したＦ／Ｆゲインζ及びωτに更新し、引き続き更新後のＦ／Ｆゲインに基づいて目標車間距離Ｌ₁ ^* 及び目標相対速度Ｖｒ^* を算出する。そしてこの目標車間距離Ｌ₁ ^* に基づいて目標車間距離Ｌ^* を算出し、これと目標相対速度Ｖｒ^* とに基づいて制御を行う。
【０１６６】
このとき、図２０におけるＦ／Ｆゲインωτは、図８の車間距離偏差Ｌ_ERR0及び相対速度Ｖｒ^* が同一条件におけるＦ／Ｆゲインよりも大きいから、先行車両が減速した時点ｔ₂₃で、割込／追いつき時の目標車間距離Ｌ₁ ^* の零への収束度合がより大きくなることになる。したがって、図２２（ａ）に示すように、目標車間距離Ｌ^* は先行車両の減速に対して速やかに収束することになる。
【０１６７】
つまり、車間距離が大きく変化し、一定車間時間で走行しない状態となった場合であっても、先行車両が切り替わったことによって車間距離が変化したときにはこの先行車両に対して緩やかに追いつくが、先行車両が減速したことによって車間距離が変化したときには、Ｆ／Ｆゲインをより大きくし、目標車間距離Ｌ₁ ^* の収束度合をより大きくしたから、減速した先行車両に速やかに追従させることができる。
【０１６８】
また、図２３に示すように、一定車速で走行している先行車両（図２３（ａ））に追いついて時点ｔ₃₁でこれを検出し、この時点ｔ₃₁における車間距離偏差Ｌ_ERR0を初期値としてフィルタ処理した目標車間距離Ｌ₁ ^* と目標車間距離最終値Ｌ₀ ^* との和からなる目標車間距離Ｌ^* （図２３（ｂ））に基づいて制御を行い、自車両が図２３（ｃ）に示すように急な加減速を伴うことなく先行車両に緩やかに追いつきつつある状態で、時点ｔ₃₂で先行車両が減速しその加減速度αがしきい値α₁ よりも小さいと、目標車間距離Ｌ₁ ^* の算出式におけるＦ／Ｆゲインωτがそれまでよりも大きな値に設定されすなわち割込／追いつき時の目標車間距離Ｌ₁ ^* の収束度合がより大きくなる。したがって、図２３（ｂ）に示すように、目標車間距離Ｌ^* は、より速やかに目標車間距離最終値Ｌ₀ ^* に収束することになって、車間距離Ｌは急な加減速を伴うことなく速やかに目標車間距離最終値Ｌ₀ ^* に収束することになる。
【０１６９】
これに対し、先行車両が減速した場合であってもこれまでと同様のＦ／Ｆゲインに基づいて目標車間距離Ｌ₁ ^* を算出するようにした場合、図２４に示すように先行車両が減速した場合であっても（図２４（ａ））、目標車間距離Ｌ₁ ^* はこれまでと同様の収束度合で収束する（図２４（ｂ））。したがって、先行車両の減速に伴って車間距離Ｌが減少し、目標車間距離Ｌ₁ ^* が零に収束する前に目標車間距離Ｌ^* を下回ってしまうと（時点ｔ₄₁）、自車両が急減速することになるが、この時点では車間距離Ｌは、まだ目標車間距離Ｌ₀ ^* に到達していないため、不要の減速を行うことになり、特に先行車両が遠方にある状態で減速すると運転者の意図にあわない車速制御が行われ違和感を与えることになる。
【０１７０】
しかしながら、先行車両が減速した場合には目標車間距離Ｌ₁ ^* の算出のためのＦ／Ｆゲインをより大きな値に変更し応答特性を高めることによって、車間距離Ｌが目標車間距離最終値Ｌ₀ ^* に到達する前に、不要な減速が行われることはなく、運転者に違和感を与えることがない。
また、Ｆ／Ｆゲインωτを変更することにより、目標車間距離Ｌ^* を目標車間距離最終値Ｌ₀ ^* に速やかに収束させることができるから、追従制御装置の構成を大幅に変更することなく容易に実現することができる。
【０１７１】
また、先行車両の切り替わりを検出したときには、切り替わり時点における、目標車間距離最終値Ｌ₀ ^* と車間距離Ｌとの偏差Ｌ_ERR0に基づいて切り替わり時の自車両の車両挙動を二次系の伝達関数で近似し、これと目標車間距離最終値Ｌ₀ ^* とをもとに目標車間距離Ｌ^* を設定するようにしたから、実際の車両挙動を考慮した適切な目標車間距離Ｌ^* を設定することができる。
【０１７２】
また、Ｆ／Ｆゲインζ及びωτを、前記先行車両の入れ替わり検出した時点での、目標車間距離最終値Ｌ₀ ^* と車間距離Ｌとの偏差Ｌ_ERR0及び相対車速Ｖｒとに基づいて設定しているから、入れ替わり時点における自車両と先行車両との相対関係に応じて適切な目標車間距離Ｌ^* を設定することができる。
ここで、車間距離センサ１２が車間距離検出手段に対応し、車速センサ１３が自車速検出手段に対応し、制動制御装置８及びエンジン出力制御装置９が制駆動力制御手段に対応し、図２１のステップＳ５５の処理が先行車両変更検出手段に対応し、ステップＳ５７の処理で目標車間距離最終値Ｌ₀ ^* を算出する処理が目標車間距離最終値算出手段に対応し、ステップＳ５９の処理が先行車両減速検出手段に対応し、Ｓ６２，Ｓ６５の処理において割込／追いつき時の目標車間距離Ｌ₁ ^* を算出する処理が目標車間距離過渡値算出手段に対応し、ステップＳ７２〜Ｓ７４の処理が制御手段に対応し、ステップＳ６２，Ｓ６５，Ｓ６７の処理において目標車間距離Ｌ^* を算出する処理が目標車間距離算出手段に対応している。
【０１７３】
次に、本発明の第６の実施の形態を説明する。
この第６の実施の形態は、上記第４の実施の形態において、追従制御用コントローラ２０での処理手順が異なること以外は同様であるので、同一部には同一符号を付与し、その詳細な説明は省略する。
すなわち、この第６の実施の形態では、図２５のフローチャートに示すように、前記図２１の第５の実施の形態におけるフローチャートにおいて、ステップＳ５９ａの処理が追加されている。すなわち、ステップＳ５９の処理で先行車加減速度αがしきい値α₁ よりも小さくないときにはステップＳ６３に移行するが、先行車加減速度αがしきい値α₁ よりも小さいときにはステップＳ５９ａに移行し、車間距離Ｌから目標車間距離最終値Ｌ₀ ^* を減算した値がしきい値ΔＬよりも大きいかどうかを判定している。前記しきい値ΔＬは、先行車両が遠方にあって目標車間距離Ｌ^* を目標車間距離最終値Ｌ₀ ^* に収束させることによって減速が生じないとみなすことの可能な値であり、例えば１０ｍ程度である。
【０１７４】
そして、Ｌ−Ｌ₀ ^* ＞ΔＬであるときにはステップＳ６０に移行してＦ／Ｆゲインを大きな値に変更するが、Ｌ−Ｌ₀ ^* ＞ΔＬでないときにはステップＳ６３に移行してＦ／Ｆゲインの変更は行わない。
ここで、先行車加減速度αがしきい値α₁ を下回るときに目標車間距離Ｌ^* を目標車間距離最終値Ｌ₀ ^* に収束させた場合、車間距離Ｌが目標車間距離最終値₀ ^* よりも十分大きいときには、先行車両が減速し車間距離Ｌが減少した場合には、Ｆ／Ｆゲインをより大きな値に設定し、目標車間距離Ｌ^* を目標車間距離最終値Ｌ₀ ^* に速やかに収束させすなわち目標車間距離Ｌ^* を減少させれば、自車両が減速することはない。これに対し、車間距離Ｌが目標車間距離最終値Ｌ₀ ^* よりも十分大きくないとき、つまり比較的接近しており、車間距離Ｌから目標車間距離最終値Ｌ₀ ^* を減算した値がしきい値ΔＬよりも大きくないときには、ステップＳ５９ａからステップＳ６３に移行してＦ／Ｆゲインの変更は行わない。よって、先行車両の減速に伴って車間距離Ｌが減少し自車両も減速することになるから、比較的接近している先行車両が減速した場合には、自車両も減速することになり、運転者に違和感を与えることはない。
【０１７５】
なお、上記第５の実施の形態と同等の作用効果を得ることができることはいうまでもない。
なお、上記各実施の形態においては、車間距離Ｌと目標車間距離Ｌ^* とが一致するように追従制御を行うようにした場合について説明したが、これに限るものではなく、例えば、車間距離Ｌを自車速Ｖｓで除算することにより得られる車間時間が、先行車両と自車両との走行状態に応じた目標車間時間となるように自車両の車速を制御して先行車両に追従するように追従制御を行う場合であっても適用することが可能である。この場合、割り込み時、追い付き時等先行車両が入れ替わるときには、前記車間時間が緩やかに目標車間時間に収束するように目標車間時間を補正し、先行車両が停止したときには前記車間時間を、目標車間時間に速やかに収束させるようにすればよい。
【０１７６】
また、上記各実施の形態においては、後輪駆動車両に適用した場合について説明したが、これに限るものではなく、前輪駆動車両或いは四輪駆動車両に適用することも可能である。
また、上記各実施の形態においては、追従制御用コントローラ２０でソフトウェアによる演算処理を行う場合について説明したが、これに限定されるものではなく、関数発生器、比較器、演算器等を組み合わせて構成した電子回路でなるハードウェアを適用して構成するようにしてもよい。
【０１７７】
また、ブレーキアクチュエータとしてディスクブレーキ７を適用した場合について説明したが、これに限定されるものではなく、ドラムブレーキ等の他のアクチュエータを適用することができることは勿論、制動圧以外に電気的に制御されるブレーキアクチュエータを適用することもでき、この場合には、目標制動圧Ｐ_B ^* に替えて、目標電流等の指令値を演算し、これを指令値に基づいてブレーキアクチュエータを制御する制動制御装置８に出力するようにすればよい。
【０１７８】
また、回転駆動源としてエンジン２を適用した場合について説明したが、これに限定されるものではなく、電動モータを適用することもでき、さらには、エンジンと電動モータとを使用するハイブリッド仕様車に適用することも可能である。
【図面の簡単な説明】
【図１】本発明の第１の実施の形態を示す概略構成図である。
【図２】追従制御用コントローラの機能構成を示すブロック図である。
【図３】図２の目標車間距離及び目標相対車速算出部２３の機能構成を示すブロック図である。
【図４】車速制御系の構成を示すブロック図である。
【図５】図２の駆動軸トルク制御部２６の機能構成を示すブロック図である。
【図６】追従制御用コントローラにおける追従走行制御処理の処理手順の一例を示すフローチャートである。
【図７】Ｆ／Ｆゲインζを設定するためのゲインマップである。
【図８】Ｆ／Ｆゲインωτを設定するためのゲインマップである。
【図９】Ｆ／Ｆゲインωτを設定するためのゲインマップである。
【図１０】第１の実施の形態の動作を説明するための説明図である。
【図１１】従来の動作を説明するための説明図である。
【図１２】第２の実施の形態における追従走行制御処理の処理手順の一例を示すフローチャートである。
【図１３】第３の実施の形態における追従走行制御処理の処理手順の一例を示すフローチャートである。
【図１４】第４の実施の形態における追従制御用コントローラの機能構成を示すブロック図である。
【図１５】第４の実施の形態における追従走行制御処理の処理手順の一例を示すフローチャートである。
【図１６】第４の実施の形態の動作を説明するための説明図である。
【図１７】第４の実施の形態の動作を説明するための説明図である。
【図１８】第５の実施の形態における追従制御用コントローラの機能構成を示すブロック図である。
【図１９】図１８の目標車間距離及び目標相対車速算出部４２の機能構成を示すブロック図である。
【図２０】第５の実施の形態における、Ｆ／Ｆゲインωτを設定するためのゲインマップである。
【図２１】第５の実施の形態における追従走行制御処理の処理手順の一例を示すフローチャートである。
【図２２】第５の実施の形態の動作を説明するための説明図である。
【図２３】第５の実施の形態の動作を説明するための説明図である。
【図２４】従来の動作を説明するための説明図である。
【図２５】第６の実施の形態における追従走行制御処理の処理手順の一例を示すフローチャートである。
【符号の説明】
２ エンジン
７ ディスクブレーキ
８ 制動制御装置
９ エンジン出力制御装置
１１ スロットルバルブ
１２ 車間距離センサ
１３ 車速センサ
１４ セットスイッチ
１５ 車速設定装置
１６ スロットル開度センサ
１７ エンジン回転速度センサ
１８ トルクコンバータ出力回転速度センサ
１９ ブレーキスイッチ
２０ 追従制御用コントローラ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle follow-up travel control device that travels following a preceding vehicle while maintaining an inter-vehicle distance from the preceding vehicle.
[0002]
[Prior art]
Conventionally, a number of such following traveling control devices for vehicles have been proposed.
By the way, when the vehicle is interrupted during vehicle speed control or inter-vehicle distance control in the state where the vehicle is following the preceding vehicle, the target inter-vehicle distance is multiplied by the predetermined inter-vehicle time. When the calculation method is used, if feedback control is performed with respect to the target inter-vehicle distance, sudden deceleration or rapid acceleration occurs, which gives the driver a sense of incongruity.
[0003]
In order to avoid this, for example, as described in Japanese Patent Application Laid-Open No. 11-20503, for example, an interruption is performed, and a vehicle that is earlier than the host vehicle is newly set as a preceding vehicle with an inter-vehicle distance shorter than the target inter-vehicle distance. Control gain that determines the response characteristics of the preceding vehicle follow-up control used to calculate the target vehicle speed when the actual inter-vehicle distance between the preceding vehicle and the host vehicle decreases more rapidly than the target inter-vehicle distance and deceleration is required. Is set so that the response characteristic becomes slow, and the target vehicle speed is calculated based on the relative speed and the inter-vehicle distance between the vehicle and the vehicle that has interrupted. As a result, a target inter-vehicle distance that is different from the target inter-vehicle distance according to the preceding vehicle speed is calculated and feedback control is performed on the target inter-vehicle distance, so that the host vehicle does not decelerate suddenly and the smooth acceleration / deceleration fluctuation is small. It is made to shift to steady follow-up running with simple control.
[0004]
[Problems to be solved by the invention]
However, in the vehicle follow-up travel control device described in the above publication, the target inter-vehicle distance final value is calculated from the inter-vehicle distance at the time of interruption with respect to the target inter-vehicle distance final value corresponding to the preceding vehicle speed, which is the inter-vehicle distance during steady following. Therefore, if the preceding vehicle accelerates or decelerates or the preceding vehicle stops during this gradually converging slow acceleration / deceleration control, the vehicle is gradually relaxed. If acceleration / deceleration control is continued, the vehicle speed responsiveness to acceleration / deceleration of the preceding vehicle will decrease, or the host vehicle will approach the stopped preceding vehicle at an extremely low speed. It will clog up and give the driver a sense of incongruity.
[0005]
In order to avoid this, for example, when the preceding vehicle performs acceleration / deceleration or when the slow acceleration / deceleration control is terminated when the preceding vehicle stops, the target inter-vehicle distance changes in a stepped manner. It will give you a sense of incongruity.
Therefore, the present invention has been made paying attention to the above-mentioned conventional unsolved problems, and the final target inter-vehicle distance, that is, the target inter-vehicle distance according to the preceding vehicle speed changed by acceleration / deceleration of the preceding vehicle, It is an object of the present invention to provide a vehicle follow-up travel control device capable of reducing the uncomfortable feeling given to the driver by smoothly approaching the inter-vehicle distance when the preceding vehicle is stopped.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a vehicle follow-up travel control device according to claim 1 of the present invention includes a host vehicle speed detection unit that detects a speed of the host vehicle, a preceding vehicle speed detection unit that detects a speed of a preceding vehicle, Inter-vehicle distance detection means for detecting the actual inter-vehicle distance between the preceding vehicle and the own vehicle, target inter-vehicle distance setting means for setting the target inter-vehicle distance between the preceding vehicle and the own vehicle, and the braking force and driving of the own vehicle Braking / driving force control means for adjusting the force, and the own vehicle speed detected by the own vehicle speed detection means so that the actual inter-vehicle distance detected by the inter-vehicle distance detection means matches the target inter-vehicle distance set by the target inter-vehicle distance setting means. And a control means for controlling the braking / driving force control means according to the vehicle, the target inter-vehicle distance setting means is based on at least the preceding vehicle speed detected by the preceding vehicle speed detecting means. Eye The target inter-vehicle distance calculating means for calculating the inter-vehicle distance, the preceding vehicle change detecting means for detecting the change of the preceding vehicle, the preceding vehicle stop detecting means for detecting the stop of the preceding vehicle, and the preceding vehicle change detecting means The target inter-vehicle distance is corrected so that the actual inter-vehicle distance gradually matches the target inter-vehicle distance when it is detected that the preceding vehicle has changed, and the preceding vehicle has stopped while the target inter-vehicle distance is being corrected. And a correction means for correcting the target inter-vehicle distance so that the actual inter-vehicle distance quickly matches the target inter-vehicle distance.
[0007]
In the first aspect of the invention, the braking / driving force according to the host vehicle speed is set so that the target inter-vehicle distance set by the target inter-vehicle distance setting means matches the actual inter-vehicle distance between the preceding vehicle and the host vehicle. The control means is controlled to control the inter-vehicle distance. At this time, in the target inter-vehicle distance setting means, the target inter-vehicle distance is calculated based on at least the preceding vehicle speed. Control is performed so that the distance and the actual inter-vehicle distance coincide with each other, but when a change in the preceding vehicle is detected, the target inter-vehicle distance based on the preceding vehicle speed is such that the actual inter-vehicle distance gradually approaches the target inter-vehicle distance. The control is performed based on the corrected target inter-vehicle distance. In other words, when the preceding vehicle changes due to an interruption of another vehicle or a change in the lane of the own vehicle, the difference between the target inter-vehicle distance and the actual inter-vehicle distance changes, so the own vehicle speed changes suddenly. Since the target inter-vehicle distance is corrected so that the inter-vehicle distance gradually matches the target inter-vehicle distance, a sudden change in the host vehicle speed is avoided.
[0008]
When it is detected that the preceding vehicle has stopped in a state where this correction is performed, the target inter-vehicle distance based on the preceding vehicle speed is set so that the actual inter-vehicle distance quickly matches the target inter-vehicle distance. Is corrected, and control is performed based on the corrected target inter-vehicle distance. In other words, when the target inter-vehicle distance is being corrected, control is performed so that the actual inter-vehicle distance gradually matches the target inter-vehicle distance based on the preceding vehicle speed. Therefore, the vehicle approaches the preceding vehicle at a very low speed with respect to the preceding vehicle that is stopped. However, when the stop of the preceding vehicle is detected, the target inter-vehicle distance based on the preceding vehicle speed is corrected so that the actual inter-vehicle distance quickly matches the target inter-vehicle distance. You will approach quickly without going.
[0009]
According to a second aspect of the present invention, there is provided a vehicle follow-up travel control apparatus comprising: a host vehicle speed detection unit that detects a speed of a host vehicle; a host vehicle speed detection unit that detects a speed of a preceding vehicle; and a vehicle between the preceding vehicle and the host vehicle. An inter-vehicle distance detecting means for detecting an actual inter-vehicle distance; a target inter-vehicle distance final value calculating means for calculating a final target inter-vehicle distance based on at least a preceding vehicle speed detected by the preceding vehicle speed detecting means; and a change in the preceding vehicle is detected. The preceding vehicle change detection means, the preceding vehicle stop detection means for detecting the stop of the preceding vehicle, and the target inter-vehicle distance based on the actual inter-vehicle distance when the preceding vehicle change means detects the change of the preceding vehicle. A transient target inter-vehicle distance calculating means for calculating a transient target inter-vehicle distance that gradually converges to a final distance value, and the target inter-vehicle distance final value is set as the target inter-vehicle distance during steady tracking, and the preceding vehicle When the change is detected, the target inter-vehicle distance setting means for setting the transient target inter-vehicle distance as the target inter-vehicle distance instead of the final target inter-vehicle distance, and the braking / driving for adjusting the braking force and the driving force of the host vehicle The braking / driving according to the vehicle speed detected by the vehicle speed detection means so that the actual vehicle distance detected by the force control means and the vehicle distance detection means matches the target vehicle distance set by the target vehicle distance setting means. And a control unit for controlling the force control unit, wherein the transient target inter-vehicle distance calculation unit detects that the preceding vehicle has stopped by the preceding vehicle stop detection unit. The transient target inter-vehicle distance is rapidly converged to the final target inter-vehicle distance.
[0010]
In the invention according to claim 2, the braking / driving force according to the host vehicle speed is set so that the target inter-vehicle distance set by the target inter-vehicle distance setting means matches the actual inter-vehicle distance between the preceding vehicle and the host vehicle. The control means is controlled to control the inter-vehicle distance. At this time, the target inter-vehicle distance setting means calculates the target inter-vehicle distance final value based on at least the preceding vehicle speed, and when performing the following tracking while keeping the predetermined inter-vehicle distance from the preceding vehicle, the target inter-vehicle distance is set. The final distance value is set as the target inter-vehicle distance, and control is performed so that the final target inter-vehicle distance value and the actual inter-vehicle distance coincide with each other. However, when a change in the preceding vehicle is detected, the final inter-vehicle distance value is replaced. Thus, the transient target inter-vehicle distance is set as the target inter-vehicle distance. This transient target inter-vehicle distance is set based on the actual inter-vehicle distance when it is detected that the preceding vehicle has changed, and is set so as to gradually converge to the target inter-vehicle distance final value.
[0011]
Therefore, when the preceding vehicle changes due to an interruption or the like, the difference between the target inter-vehicle distance and the actual inter-vehicle distance changes, so the own vehicle speed changes suddenly, but when the preceding vehicle changes, instead of the final target inter-vehicle distance value Since the transient target inter-vehicle distance is set as the target inter-vehicle distance, and this transient target inter-vehicle distance gradually converges to the final target inter-vehicle distance, sudden changes in the host vehicle speed can be avoided by performing control based on this transient target inter-vehicle distance. The
[0012]
When it is detected that the preceding vehicle has stopped in a state where the transient target inter-vehicle distance has not converged to the final target inter-vehicle distance, the degree of convergence of the transient target inter-vehicle distance to the final target inter-vehicle distance is greater than before. The value is changed to a large value, and as a result, it quickly converges to the final target inter-vehicle distance. That is, when the transient target inter-vehicle distance has not converged to the final target inter-vehicle distance, control is performed so that the actual inter-vehicle distance gradually matches the final target inter-vehicle distance, and the preceding vehicle stops in this state. In such a case, the vehicle will gradually approach the preceding vehicle and approach the preceding vehicle at an extremely low speed. However, when a stop of the preceding vehicle is detected, the actual inter-vehicle distance is controlled so as to quickly coincide with the final target inter-vehicle distance, so that the approaching vehicle does not approach the stopped preceding vehicle quickly. Will do.
[0013]
According to a third aspect of the present invention, there is provided the vehicle follow-up travel control apparatus according to the second aspect, wherein the transient target inter-vehicle distance calculating means detects the stop of the preceding vehicle and at least the own vehicle speed. Is less than a predetermined value or when the actual inter-vehicle distance is less than or equal to a predetermined value, the transient target inter-vehicle distance is quickly converged to the final target inter-vehicle distance value.
[0014]
In the invention according to claim 3, the transient target inter-vehicle distance calculating means has a large degree of convergence when the stop of the preceding vehicle is detected and the own vehicle speed is equal to or less than a predetermined value or the actual inter-vehicle distance is equal to or less than a predetermined value. Changed to a value.
Here, when the degree of convergence is changed to a large value when the stop of the preceding vehicle is detected, if the host vehicle is traveling at a relatively high speed, the target inter-vehicle distance final value is quickly determined. Therefore, the vehicle speed becomes higher and the vehicle approaches the stopped preceding vehicle at high speed. However, by changing the degree of convergence when the host vehicle speed becomes equal to or lower than the predetermined value, it is possible to avoid approaching the preceding vehicle that is stopped at high speed.
[0015]
Similarly, when the degree of convergence is changed to a large value when a stop of the preceding vehicle is detected, if the preceding vehicle stops further than the host vehicle, the target inter-vehicle distance final value is quickly determined. As the preceding vehicle is farther away, the vehicle speed increases and sudden acceleration / deceleration occurs. However, by changing the degree of convergence when the inter-vehicle distance becomes equal to or less than the predetermined value, it is possible to avoid approaching the preceding vehicle that is stopped at high speed.
[0016]
According to a fourth aspect of the present invention, there is provided the vehicle follow-up travel control apparatus according to the second or third aspect, wherein the transient target inter-vehicle distance calculation means calculates the transient target inter-vehicle distance based on a convergence gain. When the calculation and the stop of the preceding vehicle is detected, the convergence degree is increased by making the convergence gain larger than when the preceding vehicle is not stopped.
[0017]
In the invention according to claim 4, the transient target inter-vehicle distance is calculated based on the convergence gain, and when it is detected that the preceding vehicle has stopped, the convergence gain is larger than when the preceding vehicle has not stopped. doing.
Accordingly, since the convergence gain is set larger when the vehicle is stopped, the transient target inter-vehicle distance converges more quickly to the final target inter-vehicle distance.
[0018]
According to a fifth aspect of the present invention, there is provided the vehicle follow-up travel control device according to the fourth aspect, wherein the convergence gain is set to the final target inter-vehicle distance at the time when the change of the preceding vehicle is detected. It is set based on the deviation between the value and the distance between the actual vehicles and the relative vehicle speed between the preceding vehicle and the host vehicle.
In the invention according to claim 5, the deviation between the final target inter-vehicle distance and the actual inter-vehicle distance at the time when the change of the preceding vehicle is detected, and the preceding vehicle and the host vehicle at the time when the change of the preceding vehicle is detected. Since the convergence gain is set based on the relative vehicle speed, the convergence gain suitable for the state of the preceding vehicle and the host vehicle when the change of the preceding vehicle is detected is set.
[0019]
According to a sixth aspect of the present invention, there is provided the vehicle follow-up travel control apparatus according to any one of the first to fifth aspects, wherein the preceding vehicle stop detection means is detected by the preceding vehicle speed detection means. When the preceding vehicle speed is a predetermined value or less, it is determined that the preceding vehicle is stopped.
In the invention according to claim 6, in the preceding vehicle stop detecting means, the preceding vehicle is detected when the preceding vehicle speed detected by the preceding vehicle speed detecting means is equal to or lower than a predetermined value that can be considered that the preset preceding vehicle has stopped. Is determined to be stopped. Therefore, for example, when the vehicle speed of the preceding vehicle cannot be detected with high accuracy, the preceding vehicle speed may not match the actual state of the preceding vehicle, but when the preceding vehicle speed becomes somewhat small Since it is determined that the preceding vehicle is stopped, it is possible to accurately control the vehicle even when the accuracy of the preceding vehicle speed is poor.
[0020]
According to a seventh aspect of the present invention, there is provided a vehicle follow-up travel control apparatus comprising: a host vehicle speed detection unit that detects a speed of the host vehicle; a host vehicle speed detection unit that detects a speed of a preceding vehicle; and a vehicle between the preceding vehicle and the host vehicle. The inter-vehicle distance detection means for detecting the actual inter-vehicle distance, the preceding vehicle change detection means for detecting the change of the preceding vehicle, and the target inter-vehicle distance that calculates the target inter-vehicle distance final value based on at least the preceding vehicle speed detected by the preceding vehicle speed detection means The target inter-vehicle distance that gradually converges to zero based on the deviation between the actual inter-vehicle distance and the target inter-vehicle distance final value at the time when the preceding vehicle change detecting unit detects the change of the preceding vehicle by the distance final value calculating unit. Target inter-vehicle distance transient value calculating means for calculating a transient value, and a target vehicle for calculating a target inter-vehicle distance between the preceding vehicle and the own vehicle based on the sum of the target inter-vehicle distance final value and the target inter-vehicle distance transient value The distance calculation means, the braking / driving force control means for adjusting the braking force and driving force of the host vehicle, and the actual inter-vehicle distance detected by the inter-vehicle distance detection means coincide with the target inter-vehicle distance calculated by the target inter-vehicle distance calculation means. And a control unit for controlling the braking / driving force control unit in accordance with the host vehicle speed detected by the host vehicle speed detection unit, wherein the target inter-vehicle distance calculation unit The target inter-vehicle distance is calculated so that a response characteristic with respect to the final target inter-vehicle distance value of the vehicle is faster than a response characteristic with respect to the target inter-vehicle distance transient value.
[0021]
In the invention according to claim 7, the braking / driving force according to the host vehicle speed is set so that the target inter-vehicle distance calculated by the target inter-vehicle distance calculating means matches the actual inter-vehicle distance between the preceding vehicle and the host vehicle. The inter-vehicle distance controlled by the control means is controlled. At this time, in the target inter-vehicle distance calculating means, the preceding vehicle change detecting means changes the preceding vehicle, that is, the preceding vehicle is switched by interruption, the leading vehicle is newly detected by catching up, the preceding vehicle is eliminated by lane change, etc. The target based on the sum of the target inter-vehicle distance transient value calculated based on the deviation between the actual inter-vehicle distance and the target inter-vehicle distance final value at the time of detection, and at least the target inter-vehicle distance final value calculated based on the preceding vehicle speed. The inter-vehicle distance is calculated, and the response characteristic with respect to the final target inter-vehicle distance value is calculated to be faster than the response characteristic with respect to the target inter-vehicle distance transient value.
[0022]
Therefore, when there is a change in the preceding vehicle such as an interrupt, the response characteristic for the final target inter-vehicle distance value is set to be faster than the response characteristic for the target inter-vehicle distance transient value. In accordance with the response characteristic of the distance transient value, the target vehicle-to-vehicle distance final value is gradually converged, and the actual vehicle-to-vehicle distance gradually shifts to the target vehicle-to-vehicle distance final value. On the other hand, when the preceding vehicle decelerates or accelerates, the target inter-vehicle distance final value changes, but the response characteristic for the target inter-vehicle distance final value is faster than the response characteristic for the target inter-vehicle distance transient value, so the target inter-vehicle distance is The target vehicle distance final value is quickly converged, and the target vehicle distance final value is quickly secured.
[0023]
According to an eighth aspect of the present invention, there is provided the vehicle follow-up travel control apparatus according to the seventh aspect, wherein the preceding vehicle change detection means is a preceding vehicle presence / absence detection means for detecting the presence / absence of the preceding vehicle. Detects the relative vehicle speed between the preceding vehicle and the vehicle amount when the change amount of the actual inter-vehicle distance detected by the inter-vehicle distance detection means exceeds a reference value when the vehicle is detected from the non-detection state. The change in the lateral distance detected by the lateral distance detection means that detects the lateral distance between the preceding vehicle and the host vehicle when the amount of change in the relative vehicle speed detected by the relative vehicle speed detection means exceeds a reference value. It is characterized in that it is determined that the preceding vehicle has changed when at least one of the conditions is established when the amount is equal to or greater than a reference value.
[0024]
In the invention according to claim 8, when the state in which the preceding vehicle is detected from the state in which the preceding vehicle is not detected, the amount of change in the actual inter-vehicle distance between the preceding vehicle and the host vehicle becomes greater than or equal to the reference value. Either when the amount of change in relative vehicle speed between the preceding vehicle and the host vehicle exceeds the reference value, or when the amount of change in the lateral distance between the preceding vehicle and the host vehicle exceeds the reference value Since it is determined that the preceding vehicle has changed when one is established, the preceding vehicle is changed, that is, the preceding vehicle is switched due to an interruption, the preceding vehicle is newly detected due to catch-up, the preceding vehicle disappears due to a lane change, etc. Can be easily detected.
[0025]
According to a ninth aspect of the present invention, there is provided a vehicle follow-up travel control device, comprising: a host vehicle speed detection unit that detects a speed of the host vehicle; a host vehicle distance detection unit that detects an actual inter-vehicle distance between the preceding vehicle and the host vehicle; Target inter-vehicle distance calculating means for calculating the target inter-vehicle distance between the vehicle and the own vehicle, braking / driving force control means for adjusting the braking force and driving force of the own vehicle, and the actual inter-vehicle distance detected by the inter-vehicle distance detecting means Control means for controlling the braking / driving force control means according to the own vehicle speed detected by the own vehicle speed detection means so that the vehicle distance coincides with the target inter-vehicle distance calculated by the target inter-vehicle distance calculation means. In the travel control device, the target inter-vehicle distance calculating means includes a preceding vehicle change detecting means for detecting a change of the preceding vehicle, a preceding vehicle deceleration detecting means for detecting a deceleration of the preceding vehicle, and at least the preceding vehicle speed detecting means. Detected Target inter-vehicle distance final value calculating means for calculating a target inter-vehicle distance final value based on the traveling vehicle speed, and the actual inter-vehicle distance and the target inter-vehicle distance final value when the preceding vehicle change detecting means detects the change of the preceding vehicle. A target inter-vehicle distance transient value calculating means for calculating a target inter-vehicle distance transient value that gradually converges to zero based on the deviation of, and based on the sum of the target inter-vehicle distance final value and the target inter-vehicle distance transient value The target inter-vehicle distance is calculated, and when the preceding vehicle deceleration detecting means detects the deceleration of the preceding vehicle, the target inter-vehicle distance is quickly converged to the final target inter-vehicle distance value.
[0026]
In the invention according to claim 9, the braking / driving force according to the host vehicle speed is set so that the target inter-vehicle distance calculated by the target inter-vehicle distance calculating means matches the actual inter-vehicle distance between the preceding vehicle and the host vehicle. The inter-vehicle distance controlled by the control means is controlled. At this time, in the target inter-vehicle distance calculating means, the preceding vehicle change detecting means changes the preceding vehicle, that is, the preceding vehicle is switched by interruption, the leading vehicle is newly detected by catching up, the preceding vehicle is eliminated by lane change, etc. The target based on the sum of the target inter-vehicle distance transient value calculated based on the deviation between the actual inter-vehicle distance and the target inter-vehicle distance final value at the time of detection, and at least the target inter-vehicle distance final value calculated based on the preceding vehicle speed. Calculate the inter-vehicle distance.
[0027]
Therefore, when there is a change in the preceding vehicle such as an interruption, the target inter-vehicle distance will gradually converge to the final target inter-vehicle distance, there will be no sudden acceleration / deceleration, and the actual inter-vehicle distance will be moderate. Will shift to the final target inter-vehicle distance. Further, when the target vehicle distance is gradually converged to the target vehicle distance final value and the preceding vehicle deceleration detection means detects deceleration of the preceding vehicle, the target vehicle distance is quickly converged to the target vehicle distance final value. Let In other words, when the preceding vehicle decelerates, the actual inter-vehicle distance becomes shorter, so it may be less than the target inter-vehicle distance.In this state, when the control for gradually converging the target inter-vehicle distance to the final target inter-vehicle distance is performed, Even though the preceding vehicle is far away, the host vehicle will decelerate and give the driver a sense of incongruity. However, when the deceleration of the preceding vehicle is detected, the target inter-vehicle distance is quickly converged to the final target inter-vehicle distance, so that the host vehicle is prevented from performing an unnatural deceleration.
[0028]
According to a tenth aspect of the present invention, in the vehicle following traveling control device according to the ninth aspect, the target inter-vehicle distance calculating means detects the deceleration of the preceding vehicle and the actual inter-vehicle distance is The target inter-vehicle distance is quickly converged to the final target inter-vehicle distance when the target inter-vehicle distance final value is greater than a predetermined value.
[0029]
In the invention according to claim 10, in the target inter-vehicle distance calculating means, the preceding vehicle deceleration detecting means detects the deceleration of the preceding vehicle, and the deviation between the actual inter-vehicle distance and the final target inter-vehicle distance is not less than a predetermined value set in advance. In this case, the target inter-vehicle distance is quickly converged to the final target inter-vehicle distance. Therefore, if the preceding vehicle decelerates, if the actual inter-vehicle distance is greater than the target inter-vehicle distance final value, that is, if the preceding vehicle is far away, the target inter-vehicle distance is quickly converged to the target inter-vehicle distance. It will converge quickly to the final value and will not slow down more than necessary.
[0030]
Further, the vehicle follow-up travel control device according to claim 11 is the vehicle follow-up travel control device according to claim 9 or 10, wherein the target inter-vehicle distance transient value calculation means converts the target inter-vehicle distance transient value into a convergence gain. When the deceleration of the preceding vehicle is detected, the convergence degree of the convergence gain is made larger than when the preceding vehicle is not decelerated.
[0031]
In the invention according to claim 11, the target inter-vehicle distance transient value is calculated based on the convergence gain, and when it is detected that the preceding vehicle has decelerated, the convergence gain is larger than when the preceding vehicle is not decelerating. doing.
Accordingly, since the convergence gain is set larger during deceleration, the target inter-vehicle distance transient value converges more quickly to the final target inter-vehicle distance value.
[0032]
Further, the vehicle follow-up travel control apparatus according to claim 12 is the vehicle follow-up travel control apparatus according to claim 11, wherein the convergence gain is determined as the final target inter-vehicle distance at the time when the change of the preceding vehicle is detected. It is set based on the deviation between the value and the distance between the actual vehicles and the relative vehicle speed between the preceding vehicle and the host vehicle.
In the invention according to claim 12, the deviation between the final target inter-vehicle distance and the actual inter-vehicle distance when the change of the preceding vehicle is detected, and the difference between the preceding vehicle and the host vehicle when the change of the preceding vehicle is detected. Since the convergence gain is set based on the relative speed, the convergence gain suitable for the state of the preceding vehicle and the host vehicle when the change of the preceding vehicle is detected is set.
[0033]
【The invention's effect】
According to the vehicle follow-up travel control device according to claim 1 of the present invention, when setting the target inter-vehicle distance, the target inter-vehicle distance is calculated based on the preceding vehicle speed at the time of steady following, but the change of the preceding vehicle is detected. In some cases, the target inter-vehicle distance is corrected so that the actual inter-vehicle distance gradually approaches the target inter-vehicle distance to avoid a sudden change in the host vehicle speed due to a change in the preceding vehicle due to an interruption or the like, and the target inter-vehicle distance When the preceding vehicle stops while the vehicle is being corrected, the target inter-vehicle distance is corrected so that the actual inter-vehicle distance quickly matches the target inter-vehicle distance. It is possible to avoid approaching at low speed.
[0034]
Further, according to the vehicle follow-up running control device of the second aspect, the target inter-vehicle distance final value is set as the target inter-vehicle distance at the time of steady follow-up, and when the change of the preceding vehicle is detected, the target inter-vehicle distance final value is substituted. The transient target inter-vehicle distance is set as the target inter-vehicle distance, and this transient target inter-vehicle distance is set based on the actual inter-vehicle distance when the preceding vehicle is detected and gradually converges to the final target inter-vehicle distance. Since it is set, it is possible to avoid a sudden change in the host vehicle speed due to a change in the difference between the target inter-vehicle distance and the actual inter-vehicle distance at the time of interruption or the like. When it is detected that the preceding vehicle has stopped while the transient target inter-vehicle distance has not converged to the final target inter-vehicle distance, the degree of convergence of the transient target inter-vehicle distance to the final target inter-vehicle distance is increased and the target Since it converges to the inter-vehicle distance final value, it is possible to avoid approaching the preceding vehicle at which the host vehicle is stopped at an extremely low speed.
[0035]
According to the vehicle follow-up running control device according to claim 3, the degree of convergence is increased when the stop of the preceding vehicle is detected and at least the own vehicle speed is equal to or less than the predetermined value or the actual inter-vehicle distance is equal to or less than the predetermined value. Therefore, it is possible to avoid the host vehicle from approaching at high speed due to the change in the degree of convergence.
[0036]
In addition, according to the vehicle follow-up running control device according to claim 4, the transient target inter-vehicle distance is calculated based on the convergence gain, and when the preceding vehicle stops, the convergence gain is made larger than when the preceding vehicle is not stopped. Since the degree of convergence is increased by the above, the degree of convergence of the transient target inter-vehicle distance can be easily changed.
Further, according to the vehicle follow-up running control device according to claim 5, the convergence gain is the deviation between the final value of the target inter-vehicle distance and the actual inter-vehicle distance at the time when the change of the preceding vehicle is detected, and the preceding vehicle and the host vehicle. Therefore, it is possible to set an appropriate convergence gain according to the state of the preceding vehicle and the host vehicle at the time when the change of the preceding vehicle is detected.
[0037]
Further, according to the vehicle follow-up running control device according to claim 6, when the preceding vehicle speed detected by the preceding vehicle speed detecting means is equal to or lower than the predetermined value, it is determined that the preceding vehicle is stopped. Regardless of the detection accuracy of the preceding vehicle speed detecting means, it is possible to accurately detect the stop of the preceding vehicle.
According to the vehicle follow-up running control device according to claim 7, the final target inter-vehicle distance value calculated based on at least the preceding vehicle speed, the actual inter-vehicle distance and the final target inter-vehicle distance value when a change in the preceding vehicle is detected. The target inter-vehicle distance is calculated based on the sum of the target inter-vehicle distance transient value calculated on the basis of the deviation from the above, and at this time, the response characteristic for the final target inter-vehicle distance value is more than the response characteristic for the target inter-vehicle distance transient value. Since the target inter-vehicle distance is calculated so as to be faster, sudden acceleration / deceleration can be avoided when the preceding vehicle is changed, and the target vehicle inter-vehicle distance can be gradually shifted to the final value, and the preceding vehicle decelerates or accelerates. Can be quickly converged to the final value of the target inter-vehicle distance.
[0038]
According to the vehicle follow-up running control device of the eighth aspect, the preceding vehicle is controlled based on the change in the detection state of the preceding vehicle, the actual inter-vehicle distance between the preceding vehicle and the host vehicle, the relative vehicle speed, or the amount of change in the lateral distance. A change in the vehicle can be easily detected.
According to the vehicle follow-up running control device according to claim 9, the final target inter-vehicle distance value calculated based on at least the preceding vehicle speed, the actual inter-vehicle distance when the change of the preceding vehicle is detected, and the final target inter-vehicle distance value. The target inter-vehicle distance is calculated based on the sum of the target inter-vehicle distance transient value calculated based on the deviation from the above, but when the deceleration of the preceding vehicle is detected, the target inter-vehicle distance is quickly converged to the final target inter-vehicle distance value. Therefore, it is possible to avoid the host vehicle from decelerating with the deceleration while the preceding vehicle is far away, and to avoid giving the driver an uncomfortable feeling.
[0039]
According to the vehicle follow-up running control device according to claim 10, the target inter-vehicle distance is detected only when the deceleration of the preceding vehicle is detected and the deviation between the actual inter-vehicle distance and the final target inter-vehicle distance is equal to or greater than a predetermined value. Is quickly converged to the final target inter-vehicle distance, so that unnecessary deceleration can be avoided when the actual inter-vehicle distance substantially matches the final target distance.
[0040]
According to the vehicle follow-up travel control device of the eleventh aspect, the target inter-vehicle distance transient value is calculated based on the convergence gain, and when the deceleration of the preceding vehicle is detected, the convergence degree of the convergence gain is determined based on the non-preceding vehicle. Since it is made larger than that during deceleration, the degree of convergence of the target inter-vehicle distance transient value can be easily changed.
Furthermore, according to the vehicle follow-up travel control device according to claim 12, the convergence gain is determined as the deviation between the final value of the target inter-vehicle distance and the actual inter-vehicle distance at the time when the change of the preceding vehicle is detected, and the preceding vehicle and the host vehicle. Therefore, an appropriate convergence gain can be set according to the state of the preceding vehicle and the host vehicle at the time when the change of the preceding vehicle is detected.
[0041]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing a first embodiment when the present invention is applied to a rear wheel drive vehicle.
In the figure, 1FL and 1FR are left and right front wheels as driven wheels, 1RL and 1RR are rear wheels as drive wheels, and the rear wheels 1RL and 1RR are driven by an engine 2 with an automatic transmission 3 and a propeller shaft 4 respectively. Then, it is transmitted through the final reduction gear 5 and the drive shaft 6 to be rotationally driven.
[0042]
The front wheels 1FL, 1FR and the rear wheels 1RL, 1RR are each provided with a disc brake 7 that generates a braking force, and the braking hydraulic pressure of these disc brakes 7 is controlled by a braking control device 8.
The braking control device 8 generates a braking hydraulic pressure in response to the depression of the brake pedal 8a, and a target braking pressure P from the follow-up control controller 20._B ^*Is configured to generate a braking hydraulic pressure corresponding to the pressure.
[0043]
Further, the engine 2 is provided with an engine output control device 9 that controls its output. The engine output control device 9 has, for example, a method for controlling the engine speed by adjusting the opening TH of the throttle valve and a method for controlling the engine speed by adjusting the opening TH of the idle control valve. In this embodiment, a method of adjusting the opening of the throttle valve 11 is adopted. However, in this embodiment, the method of adjusting the opening of the throttle valve 11 is adopted. Has been.
[0044]
Further, the automatic transmission 3 is provided with a transmission control device 10 for controlling the shift position.
On the other hand, an inter-vehicle distance sensor 12 that detects an inter-vehicle distance L from a preceding vehicle is provided at the lower part of the vehicle body on the front side of the vehicle. The inter-vehicle distance sensor 12 is configured by, for example, a laser system that sweeps laser light forward to receive reflected light from the preceding vehicle, and receives the reflected light from the preceding vehicle, whereby the preceding vehicle and the host vehicle are The inter-vehicle distance L is measured. The inter-vehicle distance sensor 12 is set so as to be able to capture a preceding vehicle ahead.
[0045]
As the inter-vehicle distance sensor 12, for example, a distance sensor that measures using millimeter waves or ultrasonic waves can be applied.
The vehicle is also provided with a vehicle speed sensor 13 that detects the vehicle speed Vs by detecting the rotational speed of the propeller shaft 4. Further, a set switch 14 for selecting whether or not to perform the follow-up control and a vehicle speed setting device 15 for setting a desired vehicle speed in the follow-up control are provided.
[0046]
Furthermore, a throttle opening sensor 16 that detects the opening of the throttle valve 11, an engine rotation speed sensor 17 that detects the engine rotation speed, a torque converter output rotation speed sensor 18 that detects the output rotation speed of the torque converter, and a brake pedal 8a. A brake switch 19 that is turned on when the pedal is depressed is provided.
[0047]
A set for selecting whether or not to perform each detection signal of the inter-vehicle distance sensor 12, the vehicle speed sensor 13, the throttle opening sensor 16, the engine rotation speed sensor 17, the torque converter output rotation speed sensor 18, and the brake switch 19 and the follow-up control. The switch signal of the switch 14 and the vehicle speed setting signal of the vehicle speed setting device 15 are input to the tracking control controller 20.
[0048]
The follow-up control controller 20 controls the braking control device 8, the engine output control device 9, and the transmission control device 10 based on detection signals from various sensors and detection signals from various sensors such as switch signals. Thus, follow-up running control is performed in which follow-up running is performed while maintaining an appropriate inter-vehicle distance between the preceding vehicle and the following vehicle.
[0049]
The tracking control controller 20 includes, for example, a microcomputer and peripheral devices such as a storage device.
As shown in the block diagram of FIG. 2, the inter-vehicle distance L between the host vehicle and the preceding vehicle is measured by the inter-vehicle distance sensor 12 and input to the inter-vehicle distance detection unit 21 to calculate the inter-vehicle distance L. The inter-vehicle distance L is differentiated to calculate the relative speed Vr. The relative speed Vr is input to the target inter-vehicle distance final value calculation unit 22, and the inter-vehicle distance L and the relative speed Vr are the target inter-vehicle distance and target relative vehicle speed calculation unit 23 and the inter-vehicle distance F / B control unit 24. Is input.
[0050]
The target inter-vehicle distance final value calculation unit 22 calculates the preceding vehicle speed Vt according to the following equation (1) based on the relative speed Vr and the host vehicle speed Vs detected by the vehicle speed sensor 13, and the target inter-vehicle distance final value L₀ ^*Is output to the target inter-vehicle distance and target relative vehicle speed calculation unit 23. In the formula (1), T is an inter-vehicle time that is desired to be secured, and Ls is an inter-vehicle distance that is desired to be secured when the vehicle is stopped (for example, about 4 m).
[0051]
L₀ ^*= Vt x T + Ls (1)
Vt = Vs + Vr
The target inter-vehicle distance and target relative vehicle speed calculation unit 23 receives the target inter-vehicle distance final value L from the target inter-vehicle distance final value calculation unit 22.₀ ^*And the relative vehicle speed Vr, the inter-vehicle distance L, and the host vehicle speed Vs are input, and based on these, the target inter-vehicle distance L is calculated based on the following equation (2).^*And the target inter-vehicle distance L^*To the target relative vehicle speed Vr^*Is calculated. These are output to the inter-vehicle distance F / B control calculation unit 24. In addition, L in Formula (2)_ERR0Is the target inter-vehicle distance final value L when the preceding vehicle has interrupted₀ ^*And the difference between the inter-vehicle distance L at this time (= L−L₀ ^*).
[0052]
L^*= (1-a₀/ (S²+ A₁s + a₀)) ・ L_ERR0+ L₀ ^*
a₀= Ωτ²
a₁= 2ζωτ (2)
The inter-vehicle distance F / B control unit 24 is configured such that the target inter-vehicle distance L^*And target relative vehicle speed Vr^*Then, the relative vehicle speed Vr and the inter-vehicle distance L from the inter-vehicle distance detecting unit 21 and the own vehicle speed Vs are input, and based on these, the inter-vehicle distance L is set as the target inter-vehicle distance L.^*Target vehicle speed Vs to obtain a value according to^*Is calculated.
[0053]
This target vehicle speed Vs^*Is input to the vehicle speed control unit 25, and the vehicle speed control unit 25 converts the host vehicle speed Vs into the target vehicle speed Vs.^*Command value Tq of drive shaft torque to obtain a value corresponding to^*Is calculated.
In the drive shaft torque control unit 26, the drive shaft torque command value Tq^*Based on the target braking pressure P_B ^*Or throttle opening command value θ^*Are calculated and the braking pressure command value P is supplied to the braking control device 8 or the engine output control device 9 as the control target._B ^*Or throttle opening command value θ^*Output as.
[0054]
FIG. 3 is a block diagram showing details of the target inter-vehicle distance and target relative vehicle speed calculation unit 23. The target inter-vehicle distance and target relative vehicle speed calculation unit 23 calculates the preceding vehicle speed Vt from the own vehicle speed Vs and the relative vehicle speed Vr. A preceding vehicle speed estimating unit 23a for estimating, a preceding vehicle stop determining unit 23b for determining whether or not the preceding vehicle has stopped based on the preceding vehicle speed Vt, an own vehicle speed Vs, a relative vehicle speed Vr, an inter-vehicle distance L, and a target inter-vehicle distance final Value L₀ ^*And an F / F gain calculation unit 23c that calculates an F / F gain that is ωτ and ζ in the equation (2) based on the determination result of the preceding vehicle stop determination unit 23b, and the own vehicle speed Vs, Relative vehicle speed Vr, inter-vehicle distance L, target inter-vehicle distance final value L₀ ^*And the target inter-vehicle distance L based on the F / F gains ωτ and ζ from the F / F gain calculation unit 23c.^*And target relative vehicle speed Vr^*The target inter-vehicle distance and target relative vehicle speed calculation unit 23d is calculated.
[0055]
FIG. 4 shows a vehicle speed control system, and the running resistance estimation unit in FIG. 4 is a target drive shaft torque command value Tq.^*And the vehicle speed Vs using the following equation (3)_DHIs estimated and fed back to eliminate the influence of disturbances such as gradient, air resistance, and rolling resistance. In addition, M in Formula (3)_VIs a vehicle weight, s is a Laplace operator, and H (s) is a filter.
[0056]
T_DH= H (s) ・ (M_V・ S ・ Vs−Tq^*) (3)
Assuming that the disturbance to the vehicle speed control system is eliminated by estimating the running resistance in this way, the target vehicle speed Vs^*To the host vehicle speed Vs can be expressed by the following equation (4).

As a result, the control gain K_spBy setting to an appropriate value, the response characteristic of the vehicle speed control system can be matched with the desired response characteristic.
[0057]
Therefore, the target vehicle speed Vs^*And the control gain K_SPMultiplied by the running resistance T_DHDrive shaft torque command value Tq^*Can be calculated.
FIG. 5 is a block diagram showing details of the drive shaft torque control unit 26. In the figure, 26a indicates a drive shaft torque command value Tq.^*Based on the engine torque command value T in consideration of the state of the automatic transmission 3 and its gear ratio._E ^*The engine torque command value calculator 26b calculates the engine torque command value T calculated by the engine torque command value calculator 26a._E ^*And the engine speed N from the engine output control device 9_EFor example, by referring to an engine map representing the correspondence between engine torque, throttle opening, and engine speed, the engine torque command value T_E ^*Throttle opening command value θ to output^*Is a throttle opening calculation unit.
[0058]
The throttle opening command value θ calculated by the throttle opening calculation unit 26b^*Is input to the engine torque calculator 26c, and the engine torque calculator 26c receives the throttle opening command value θ.^*And engine speed N_EBased on the above, for example, a preset engine speed N_EReferring to a table map representing the engine torque for the engine torque T when the throttle opening is in the fully closed state_ELIMIs calculated.
[0059]
Engine torque T when the throttle opening calculated by the engine torque calculator 26c is in a fully closed state_ELIMIs input to the braking / driving force correction value calculation unit 26d, and the braking / driving force correction value calculation unit 26d receives the engine torque T_ELIMThe drive shaft torque Tq generated by the engine 2 when the throttle opening is fully closed based on₀The braking force calculation unit 26e calculates the drive shaft torque command value Tq.^*And the drive shaft torque Tq generated by the engine 2 when the throttle opening is fully closed₀The brake operation amount input to the brake hydraulic pressure servo system, that is, the braking pressure command value P_B ^*Is calculated.
[0060]
That is, the torque amplification factor of the torque converter is set to R_TThe gear ratio of the automatic transmission 3 is R_AT, The differential gear ratio is R_DEF, Engine inertia J_E, Engine speed N_EThen, drive shaft torque Tq and engine torque T_ECan be expressed by the following equation (5).
Tq = R_T・ R_AT・ R_DEF・ T_E-J_E・ (DN_E/ Dt) …… (5)
Therefore, the drive shaft torque command value Tq^*On the other hand, the engine torque command value T based on the following equation (6)_E ^*To calculate the engine torque command value T_E ^*Is calculated using an engine map, and it is determined whether or not the throttle opening θ is fully closed.
[0061]
T_E ^*= J_E・ (DN_E/ Dt) + Tq^*/ (R_T・ R_AT・ R_DEF) …… (6)
This engine torque command value T_E ^*If the throttle opening θ calculated on the basis of θ is θ> 0, the drive shaft torque command value Tq is obtained using only the engine torque without using the brake.^*The torque specified in can be realized. On the other hand, if θ = 0, the throttle opening is fully closed, and the brake operation amount for making the drive shaft torque coincide with the command value is calculated in consideration of the drive shaft torque output by the engine 2 at this time. .
[0062]
Thus, the engine torque command value T_E ^*And brake torque command value T_BR ^*The distribution control law is as follows. That is, the engine torque command value T_E ^*Throttle opening command value θ calculated based on^*Is θ^*When> 0, the following equation (7) is established, and the drive shaft torque command value Tq^*In contrast, the engine torque shown in the equation (8) may be generated.
[0063]
T_BR= 0
Tq = R_T・ R_AT・ R_DEF・ T_E-J_E・ (DN_E/ Dt) (7)
T_E= J_E・ (DN_E/ Dt) + Tq^*/ (R_T・ R_AT・ R_DEF) …… (8)
On the other hand, the throttle opening command value θ^*Is θ^*= 0, the engine torque when the throttle opening is zero is T_ELIMThen, since the equation (5) becomes the following equation (9), the drive shaft torque command value Tq^*On the other hand, the brake torque of equation (10) may be generated.
[0064]
Tq = R_T・ R_AT・ R_DEF・ T_ELIM-J_E・ (DN_E/ Dt) -T_BR...... (9)
T_BR= -Tq + R_T・ R_AT・ R_DEF・ T_ELIM-J_E・ (DN_E/ Dt) (10)
And the brake cylinder area is S_B, The radius of the brake rotor is R_BBrake pad friction coefficient μ_BThen, the brake torque command value T_BRBraking pressure command value P which is a brake operation amount_B ^*Is the following equation (11).
[0065]
P_B ^*= T_BR/ (8 ・ S_B・ R_B・ Μ_B) (11)
Next, the operation of the first embodiment will be described with reference to the flowchart of FIG. 6 showing the procedure of the follow-up running control process executed by the follow-up control controller 20. The follow-up control controller 20 executes the follow-up running control process shown in FIG. 6 as a timer interrupt process every 10 msec, for example. This process is performed when the switch signal of the set switch 14 is OFF, that is, when the following traveling instruction is not performed, and when it is determined that the brake switch 19 is ON, that is, the brake pedal 8a is depressed. Absent. In addition, a flag F used during processing₁~ F_ThreeIs set to zero as the initial value at startup.
[0066]
In the follow-up control controller 20, first, in step S1, detection signals of the inter-vehicle distance sensor 12 and the vehicle speed sensor 13, a switch signal of the set switch 14, a setting signal of the vehicle speed setting device 15 and the like are read, and the own vehicle speed Vs. The inter-vehicle distance L is calculated. Next, the process proceeds to step S2, and the relative vehicle speed Vr between the host vehicle and the preceding vehicle is calculated by differentiating the inter-vehicle distance L calculated in step S1.
[0067]
Next, the process proceeds to step S3 to determine whether or not a preceding vehicle has been detected. This determination is performed, for example, by calculating the inter-vehicle distance L from the detection signal of the inter-vehicle distance sensor 12 and determining whether the inter-vehicle distance L is within the detection limit value of the inter-vehicle distance sensor 12. When the inter-vehicle distance L is greater than the detection limit value, it is determined that there is no preceding vehicle, and the flag F is determined in step S4.₁And F₂And F_ThreeF₁= 0, F₂= 0, F_ThreeAfter setting = 0, the process proceeds to step S22 described later. On the other hand, when the inter-vehicle distance L is within the detection limit value, it is determined that there is a preceding vehicle, and the process proceeds to step S5.
[0068]
In this step S5, it is determined whether or not the vehicle is traveling at a certain inter-vehicle time. This determination is made, for example, when the absolute value of the relative vehicle speed Vr is less than a predetermined value Vr_S(| Vr | <Vr_S), And the target inter-vehicle distance L at the normal time set in advance and the inter-vehicle distance L_U ^*The absolute value of the deviation is a predetermined value ΔL_SLess than (| L_U ^*−L | <ΔL_S) Depending on whether or not the determination condition is satisfied.
[0069]
When it is determined that the vehicle is not traveling in a certain inter-vehicle time, the process proceeds to step S6, where₁Is F₁Determine if = 1. And flag F₁Is F₁When not = 1, the process proceeds to step S7, and the inter-vehicle distance deviation L at the time of interruption is calculated based on the following equation (12)._ERR0Is calculated. And this inter-vehicle distance deviation L at the time of interruption_ERR0And the relative speed Vr calculated in step S2 is stored in a predetermined storage area. Then, the process proceeds to step S8. Flag F₁Is F₁If not = 1, the process proceeds to step S8.
[0070]
L_ERR0= LL₀ ^*                                  (12)
In step S8, the vehicle speed Vt of the preceding vehicle calculated by the equation (1) is a threshold value V at which the preset preceding vehicle can be regarded as stopped.₁(For example, about 1 km / h) is determined, and Vt <V₁If so, the process proceeds to step S9. In this step S9, the host vehicle speed Vs is a threshold value V that allows the preset host vehicle to be regarded as being in a low speed traveling state.₂It is determined whether it falls below (for example, about 12 km / h).
[0071]
And Vs <V₂If so, the process proceeds to step S10 and the flag F₂Is F₂= 1 and flag F₂Is F₂When not = 1, the process proceeds to step S11, and the inter-vehicle distance deviation L calculated in step S7 is calculated._ERR0And F / F gains ζ and ωτ corresponding to the relative speed Vr calculated in step S2 are set in accordance with gain maps shown in FIGS. And flag F is set to F₂After setting = 1, the process proceeds to step S12 described later. Flag F in step S10₂Is F₂When = 1, the process proceeds to step S12 as it is.
[0072]
On the other hand, in step S8, the preceding vehicle speed Vt becomes the threshold value V.₁If the vehicle speed Vs does not fall below the threshold V,₂If not less than the value, the process proceeds to step S13 and the flag F_ThreeIs F_Three= 1 and flag F_ThreeIs F_ThreeWhen not = 1, the process proceeds to step S14, and the inter-vehicle distance deviation L calculated in step S7._ERR0And F / F gains ζ and ωτ corresponding to the relative speed Vr calculated in step S2 are set in accordance with gain maps shown in FIGS. And flag F_ThreeF_ThreeAfter setting = 1, the process proceeds to step S15. Flag F in step S13_ThreeIs F_ThreeWhen = 1, the process proceeds to step S15 as it is.
[0073]
On the other hand, when it is determined in step S5 that the vehicle is traveling at a certain inter-vehicle time, the process proceeds to step S16, and each flag F₁~ F_ThreeF₁= 0, F₂= 0, F_ThreeAfter setting = 0, the process proceeds to step S17.
In step S12, the F / F gains ζ and ωτ set from the gain map shown in FIGS. 7 and 8 in the process of step S11, and the inter-vehicle distance deviation L calculated in step S7._ERR0And the target inter-vehicle distance final value L calculated by the equation (1) based on the preceding vehicle speed Vt₀ ^*Based on the above, the target inter-vehicle distance L according to the above equation (2)^*Is calculated. Also, the calculated target inter-vehicle distance L^*To target relative vehicle speed Vr^*Is calculated.
[0074]
In step S15, the F / F gains ζ and ωτ set from the gain maps shown in FIGS. 7 and 9 in the process of step S14, and the inter-vehicle distance deviation L calculated in step S7._ERR0And the target inter-vehicle distance final value L calculated by the equation (1) based on the preceding vehicle speed Vt₀ ^*Based on the above, the target inter-vehicle distance L according to the above equation (2)^*Is calculated. Also, the calculated target inter-vehicle distance L^*To target relative vehicle speed Vr^*Is calculated.
[0075]
In step S17, the target inter-vehicle distance final value L based on the equation (1).₀ ^*And calculate this as the target inter-vehicle distance L^*Set as. Also, the target relative vehicle speed Vr^*Is set to zero.
Here, FIG. 7 is a gain map for setting the F / F gain ζ, and the inter-vehicle distance deviation L during interruption._ERR0And the relative speed Vr. And the F / F gain ζ is the inter-vehicle distance deviation L at the time of interruption._ERR0Is set to increase as the vehicle increases from zero to the negative direction, that is, as the preceding vehicle and the host vehicle approach each other, and as the vehicle increases from zero to the positive direction, that is, the preceding vehicle and the host vehicle tend to move away from each other. , Set to tend to be smaller. The relative speed Vr increases from zero to the negative direction, that is, tends to decrease as the host vehicle approaches the preceding vehicle, and the relative speed Vr increases from zero to the positive direction, that is, the host vehicle and the leading vehicle. The vehicle tends to become smaller as the vehicle moves away.
[0076]
8 and 9 are gain maps for setting the F / F gain ωτ, and the inter-vehicle distance deviation L at the time of interruption._ERR0And the relative speed Vr. The F / F gain ωτ is the inter-vehicle distance deviation L_ERR0Increases from zero to the negative direction, i.e., tends to increase as the preceding vehicle and the host vehicle approach, and tends to decrease as the leading vehicle increases from the positive direction, i.e., as the preceding vehicle and the host vehicle move away from each other. Is set. The relative speed Vr increases from zero to the negative direction and is set to increase as the host vehicle and the preceding vehicle tend to approach each other, and the relative speed Vr increases from zero to the positive direction. It is set to a tendency to become smaller as the preceding vehicle tends to move away. Further, the F / F gain ωτ in FIG. 8 is set to be larger than the F / F gain ωτ under the same conditions in FIG.
[0077]
In addition, in FIG. 7, FIG. 8, FIG._ERR0And a plurality of relative speeds Vr are set stepwise, and the F / F gain is set for the representative value of the inter-vehicle distance deviation and relative speed at the time of interruption._ERR0And the F / F gain corresponding to the representative value of the intervehicular distance deviation and relative speed at the time of interruption closest to the relative speed Vr, the actual intervehicular distance deviation L_ERR0And an F / F gain corresponding to the relative speed Vr.
[0078]
Note that the F / F gain may be changed continuously instead of stepwise.
Further, the case where the gain map is stored in a predetermined storage area has been described, but the relationship between the inter-vehicle distance deviation and relative speed at the time of interruption and the F / F gain ζ, the inter-vehicle distance deviation at the time of interruption, and It may be stored as a function expression representing the relationship between the relative speed and the F / F gain ωτ, and the F / F gain ζ and ωτ may be set based on this function expression.
[0079]
In this way, in the steps S12, S15, S17, the target inter-vehicle distance L^*And target relative vehicle speed Vr^*Is calculated, the process proceeds to step S21. And target inter-vehicle distance L^*And target relative vehicle speed Vr^*Target acceleration / deceleration G for traveling_DIs calculated.
This target acceleration / deceleration G_DIs calculated as follows. That is, first, from the actual inter-vehicle distance L to the target inter-vehicle distance L^*Is subtracted and the inter-vehicle distance deviation ΔL (= L−L^*) Is calculated. Then, from the relative speed Vr to the target relative vehicle speed Vr^*Is subtracted to obtain a relative vehicle speed deviation ΔVr (= Vr−Vr).^*) Is calculated.
[0080]
And the target acceleration / deceleration G according to the following equation (13)_DIs calculated.
G_D= K₁・ ΔL + K₂・ ΔVr (13)
In the formula, F₁And F₂Is a preset control gain.
Next, the process proceeds to step S22, where the target acceleration / deceleration G calculated in step S21 is obtained._DTo target vehicle speed Vs^*Is calculated. This target vehicle speed Vs^*Is calculated according to the following equation (14), for example. In Expression (14), Δt is a sampling time in the timer interrupt process. Vs^*(N-1) is the previous target vehicle speed Vs.^*It is.
[0081]
Vs^*(N) = Vs^*(N-1) + G_D× Δt (14)
The calculated target vehicle speed Vs^*Is greater than the set vehicle speed Vc set by the vehicle speed setting device 15, or when no preceding vehicle is detected, the set vehicle speed Vc is set to the target vehicle speed Vs.^*And
Next, the process proceeds to step S23, where the target vehicle speed Vs^*Based on the drive shaft torque command value, that is, the target torque Tq as described above.^*Is calculated.
[0082]
Next, the process proceeds to step S24, and the target torque Tq calculated in step S23.^*Throttle opening command value θ^*And braking pressure command value P_B ^*Is output to the engine output control device 9 or the braking control device 8 to generate a braking torque or a driving torque, the timer interruption process is terminated, and the program returns to a predetermined main program.
[0083]
Therefore, it is assumed that the vehicle is currently traveling on the traveling lane in the follow-up traveling control state, and when the preceding vehicle cannot be detected in the same lane as the traveling lane of the own vehicle in this state, the process of FIG. 6 is executed. In addition, detection signals from various sensors and the like are read (step S1) and the relative speed Vr is calculated (step S2). However, since the preceding vehicle cannot be detected, the process proceeds from step S3 to S4 to step S22 as it is. The preset vehicle speed Vc preset by the driver is used as the target vehicle speed Vs.^*Then, the process proceeds to step S23, and this target vehicle speed Vs^*Based on the vehicle speed deviation ΔV between the current vehicle speed Vs and the current vehicle speed Vs^*Is calculated, a throttle opening command value or a brake fluid pressure command value that can generate this is calculated, and the braking control device 8 or the engine output control device 9 is controlled to perform acceleration / deceleration control (step S24).
[0084]
That is, the target torque Tq^*If the engine speed is positive, it is determined that the request is for acceleration, and the engine output control device 9 increases the throttle opening to accelerate the vehicle, so that the host vehicle speed Vs is reduced to the target vehicle speed Vs.^*On the contrary, the target torque Tq^*Is negative, the braking control device 8 causes the disc brake 7 to generate a braking force so that the host vehicle speed Vs is reduced to the target vehicle speed Vs.^*To match.
[0085]
When the vehicle enters the travel lane of the host vehicle from the traveling state in which there is no preceding vehicle, the vehicle is in a state of detecting the preceding vehicle. In FIG. 6, the process proceeds from step S3 to step S5. Since there is no flag, the process proceeds to step S6.₁Is F₁= 0, the process proceeds to step S7, and the inter-vehicle distance deviation L is calculated based on the equation (12)._ERR0Is calculated. The calculated inter-vehicle distance deviation L_ERR0And the relative speed Vr calculated in step S2 are stored in a predetermined storage area.
[0086]
Then, the process proceeds to step S8, and the inter-vehicle distance deviation L at the time of interruption._ERR0The preceding vehicle speed Vt calculated when calculating the₁It is determined whether it is smaller than.
At this time, the preceding vehicle is running in an interrupt, and the threshold value V₁Since the vehicle is traveling at a speed higher than S8, the process proceeds from Step S8 to Step S13, and the flag F_ThreeIs F_Three= 0, the process proceeds to step S14, and the inter-vehicle distance deviation L calculated in step S7 is calculated._ERR0And the relative vehicle speed Vr, the F / F gains ζ and ωτ are set based on the gain maps shown in FIGS. And flag F_ThreeF_Three= 1.
[0087]
Based on the set F / F gains ζ and ωτ, the target inter-vehicle distance L^*And target relative vehicle speed Vr^*(Step S15), and based on these, the target acceleration / deceleration G_DTo calculate the target acceleration / deceleration G_DBased on the target vehicle speed Vs^*To calculate this target vehicle speed Vs^*And the target torque Tq that can be matched based on the vehicle speed Vs^*Is calculated and brake control or engine control is performed by controlling the brake control device 8 or the engine output control device 9 based on this (steps S21 to S24).
[0088]
Then, in a state where the preceding vehicle is captured and not traveling in a certain inter-vehicle time and the preceding vehicle is not stopped, the process proceeds to step S15 via steps S3, S5, S6, S8, and S13, and the preceding vehicle is Inter-vehicle distance deviation L at the time of interruption_ERR0And the relative vehicle speed Vr and the target inter-vehicle distance L based on the equation (2) based on the F / F gains ζ and ωτ set in step S14.^*And the inter-vehicle distance L is the target inter-vehicle distance L^*Control is performed so that
[0089]
Here, when the interruption is performed, the target inter-vehicle distance final value L based on the vehicle speed Vt of the preceding vehicle.₀ ^*Inter-vehicle distance deviation L_ERR0The target inter-vehicle distance L, which is the sum of the added amount based on^*Is calculated, and this target inter-vehicle distance L^*The inter-vehicle distance control is performed so that
Further, the inter-vehicle distance deviation L at the time of interruption_ERR0As shown in the above equation (2), the amount of addition based on_ERR0To the coefficient (1- (a₀/ (S²+ A₁s + a₀)), That is, the inter-vehicle distance deviation L at the time of interruption_ERR0Since the filter processing is performed with the initial value as the initial value, the inter-vehicle distance deviation L at the time of interruption_ERR0, That is, the first term of the equation (2) gradually converges to zero, and thus the target inter-vehicle distance L^*Is the final target distance L₀ ^*And finally the target inter-vehicle distance L^*Is the final target distance L₀ ^*Will converge to.
[0090]
Then, when the host vehicle travels in a certain inter-vehicle time, the process proceeds from step S5 to S16 to step S17, and the target inter-vehicle distance final value L₀ ^*Is the target inter-vehicle distance L^*And the target relative vehicle speed Vr^*Is set to zero and the target inter-vehicle distance L is based on the preceding vehicle speed Vt.^*The inter-vehicle distance control is performed so that the traveling state for a certain inter-vehicle time is continued.
[0091]
Therefore, when the preceding vehicle interrupts, the target inter-vehicle distance final value L based on the vehicle speed Vt of the preceding vehicle immediately₀ ^*The target inter-vehicle distance final value L is not controlled to be₀ ^*Inter-vehicle distance deviation L when interrupted_ERR0The target inter-vehicle distance L approximated by a quadratic function as the ideal vehicle behavior of the host vehicle is added.^*Therefore, the host vehicle can be prevented from suddenly decelerating or rapidly accelerating due to the start of following the interrupted preceding vehicle.
[0092]
At this time, the target inter-vehicle distance L^*Is the final target distance L₀ ^*Because it will converge to_ERR0The amount of addition based on the target inter-vehicle distance final value L₀ ^*The target final inter-vehicle distance L from the state added to₀ ^*The driver will not be discomforted.
On the other hand, the following deviation L_ERR0The added amount based on the target inter-vehicle distance final value L₀ ^*When the preceding vehicle stops in the state where the inter-vehicle distance control is performed in addition to the vehicle speed, the preceding vehicle decelerates and the preceding vehicle speed Vt becomes the threshold value V₁When the value falls below, the process proceeds from step S8 to step S9.
[0093]
At this time, the vehicle speed Vs is the threshold value V₂While the vehicle is traveling in a state that does not fall below, the process proceeds from step S9 to step S13 through step S13, and continues to the target inter-vehicle distance final value L.₀ ^*Inter-vehicle distance deviation L when interrupted_ERR0The value obtained by adding the addition amount based on the target inter-vehicle distance L^*The inter-vehicle distance is gradually set to the target inter-vehicle distance final value L.₀ ^*Control is performed so as to shift to.
[0094]
From this state, as the preceding vehicle stops, the target inter-vehicle distance final value L₀ ^*Decreases, the host vehicle decelerates and the host vehicle speed Vs becomes the threshold value V₂If it falls below, the process moves from step S9 to step S10. At this time, the flag F₂Is F₂= 0, the process proceeds to step S11 as it is, and this time, the inter-interval distance deviation L stored in the predetermined storage area in the process of step S7 based on the gain map of FIG._ERR0And the F / F gain ωτ corresponding to the relative vehicle speed Vr and the flag F₂F₂= 1. Then, the F / F gain ωτ in the equation (2) is changed to the F / F gain ωτ newly searched from the gain map of FIG. 8, and subsequently the target inter-vehicle distance L from the equation (2) in the same manner as described above.^*And the inter-vehicle distance control is performed in the same manner as described above.
[0095]
Here, in FIG. 8, since the value of the F / F gain ωτ is set larger than that in FIG. 9, the first term of the equation (2) calculated based on the F / F gain ωτ is: It will converge to zero more quickly than before.
Therefore, until the preceding vehicle stops, the target inter-vehicle distance final value L is relatively moderate.₀ ^*When the stop of the preceding vehicle is detected from the state where the vehicle has converged, the target inter-vehicle distance final value L immediately₀ ^*Therefore, the host vehicle approaches the stopped preceding vehicle promptly.
[0096]
That is, as shown in FIG. 10, the time t when the preceding vehicle interrupts.₀As an F / F gain ωτ, an inter-vehicle distance deviation L_ERR0And ωτ based on the relative vehicle speed Vr at this time_LIs set (FIG. 10 (b)), and the preceding vehicle is₁Starts deceleration at time t₂Stop at time t₂F / F gain ωτ is ωτ_LLarger than ωτ_HSet to
[0097]
At this time, as shown in FIG. 10C, the target inter-vehicle distance final value L₀ ^*Changes in proportion to the vehicle speed Vt of the preceding vehicle. And this target inter-vehicle distance final value L₀ ^*, Inter-vehicle distance deviation L_ERR0The value obtained by adding the addition amount based on the target inter-vehicle distance L^*The amount of addition is first calculated as F / F gain ωτ_LGradually decreases at a rate according to the target distance L^*Is the final target distance L₀ ^*Converge to.
[0098]
And time t₂The preceding vehicle stops and the F / F gain ωτ is a large value ωτ._HWhen the change is made, the convergence rate of the added amount based on the inter-vehicle distance deviation at the time of interruption increases, and the target inter-vehicle distance L^*Is the final target distance L immediately₀ ^*Converge to.
Target vehicle speed Vs^*Is the target inter-vehicle distance L as shown in FIG.^*The time t₂After the preceding vehicle stops, the target vehicle speed V^*Quickly converges to zero, that is, the host vehicle promptly reaches the target inter-vehicle distance L.^*Will reach the position of and stop.
[0099]
On the other hand, as shown in FIG.₂Even when the preceding vehicle stops, the F / F gain ωτ is set to a constant value (FIG. 11B). Therefore, as shown in FIG. 11C, the target inter-vehicle distance L^*Is the time t₂Even after the preceding vehicle stops, the vehicle speed will gradually decrease and the target vehicle speed Vs^*Will also decrease slowly, that is, approach the stopped preceding vehicle at an extremely low speed (FIG. 11 (d)).
[0100]
However, according to the first embodiment, as shown in FIG. 10, when the preceding vehicle stops, the F / F gain ωτ is set to a large value and the target inter-vehicle distance L^*To the target inter-vehicle distance final value L immediately₀ ^*The target vehicle speed Vs^*Can be quickly reduced, and the stopped preceding vehicle can be quickly approached without approaching the stopped preceding vehicle at an extremely low speed.
[0101]
Further, when the preceding vehicle stops in a distant state, the target vehicle speed Vs^*Is the inter-vehicle distance deviation L_ERR0The larger the value becomes, the larger it becomes and the process proceeds from step S9 to step S13, and the F / F gain ωτ is not changed. Therefore, the inter-vehicle distance control is gradually performed continuously, and it is possible to avoid a rapid approach to a preceding vehicle stopped at a distance.
[0102]
Further, the preceding vehicle speed Vt is the threshold value V₁The target inter-vehicle distance L^*To the target inter-vehicle distance final value L immediately₀ ^*Therefore, even if the accuracy of the preceding vehicle speed Vt is low, it is possible to accurately detect the stop of the preceding vehicle, and the target inter-vehicle distance L^*To the target inter-vehicle distance final value L immediately₀ ^*Can be converged to.
[0103]
Further, the preceding vehicle speed Vt is the threshold value V₁And the vehicle speed Vs is lower than the threshold value V.₂The target inter-vehicle distance L^*To the target inter-vehicle distance final value L immediately₀ ^*Therefore, the host vehicle does not accelerate in a state where the host vehicle speed Vs is large and the host vehicle does not want to rapidly approach the preceding vehicle.
Further, by changing the F / F gain ωτ, the target inter-vehicle distance L^*The target inter-vehicle distance final value L₀ ^*Therefore, it can be easily realized without significantly changing the configuration of the tracking control device.
[0104]
When a change of the preceding vehicle due to an interruption is detected, the target inter-vehicle distance final value L at the time of interruption₀ ^*And inter-vehicle distance deviation L, which is the deviation between_ERR0Based on this, the vehicle behavior of the host vehicle at the time of interruption is approximated by a transfer function of a secondary system, and based on this, the target inter-vehicle distance final value L₀ ^*To correct the target vehicle distance L^*Therefore, the appropriate target inter-vehicle distance L in consideration of actual vehicle behavior is set.^*Can be set.
[0105]
Further, the F / F gains ζ and ωτ are set to the target inter-vehicle distance final value L when the interruption of the preceding vehicle is detected.₀ ^*Deviation L between vehicle distance L_ERR0And the relative vehicle speed Vr, an appropriate target inter-vehicle distance L according to the relative relationship between the host vehicle and the preceding vehicle at the time of interruption.^*Can be set.
Further, the preceding vehicle speed Vt is the threshold value V₁Since it is determined whether or not the F / F gains ζ and ωτ are changed when the vehicle speed is lower than the vehicle speed, the preceding vehicle speed Vt is calculated based on the relative vehicle speed Vr and the host vehicle speed Vs. Even when the accuracy of the vehicle speed Vt is low, the traveling state of the preceding vehicle can be accurately detected, and the F / F gains ζ and ωτ can be changed accordingly.
[0106]
Here, the inter-vehicle distance sensor 12 corresponds to the inter-vehicle distance detection means, the vehicle speed sensor 13 corresponds to the own vehicle speed detection means, the braking control device 8 and the engine output control device 9 correspond to the braking / driving force control means, FIG. The processing of steps S3 and S5 corresponds to the preceding vehicle change detecting means, the processing of calculating the preceding vehicle speed Vt from the equation (1) in the processing of step S8 corresponds to the preceding vehicle speed detecting means, and the processing of step S8 is preceded. Vehicle speed Vt is Vt <V₁The processing for determining whether the vehicle is a preceding vehicle stop detection means corresponds to the processing at steps S12, S15, and S17, and the processing at steps S12, S15, and S17 corresponds to the target inter-vehicle distance L.^*The processing for calculating the target vehicle distance calculation means corresponds to the target vehicle distance calculation means, the processing of steps S12 and S15 corresponds to the correction means and the transient target vehicle distance calculation means, and the target vehicle distance final value L in the processing of steps S12 and S15.₀ ^*The process of calculating S1 corresponds to the target inter-vehicle distance final value calculation means, and the processes of steps S21 to S24 correspond to the control means.
[0107]
Next, a second embodiment of the present invention will be described.
Since the second embodiment is the same as the first embodiment except that the processing procedure in the follow-up control controller 20 is different, the same reference numerals are given to the same parts, and the detailed description thereof is omitted. Description is omitted.
That is, in the second embodiment, as shown in the flowchart of FIG. 12, in the flowchart of the first embodiment of FIG. 6, the process of step S9a is executed instead of the process of step S9. . That is, in step S8, the preceding vehicle speed Vt is the threshold value V.₁When it is determined that the vehicle distance is less than the threshold value L, the process proceeds to step S9a.₀Judge whether or not below. And the inter-vehicle distance L is a threshold value L₀When the distance is less than S, the process proceeds to S12 via steps S10 and S11, and the target inter-vehicle distance L is determined based on the relatively large F / F gain ωτ.^*And the inter-vehicle distance L is the threshold value L₀If not, the process proceeds to S15 through steps S13 and S14, and the target inter-vehicle distance L based on the relatively small F / F gain ωτ.^*Is calculated.
[0108]
Therefore, the threshold value L₀Is set appropriately (for example, about 14 m), the preceding vehicle stops far away from the host vehicle, and the inter-vehicle distance L increases, that is, the target vehicle speed V^*By increasing the F / F gain ωτ while the value is large, the target inter-vehicle distance L^*Increases and the target vehicle speed V^*It is possible to avoid a sudden approach to a preceding vehicle that is stopped in a state where is controlled to a larger value.
[0109]
Needless to say, the same effects as those of the first embodiment can be obtained.
Next, a third embodiment of the present invention will be described.
The third embodiment is a combination of the first embodiment and the second embodiment. In the first embodiment, since the processing procedure in the tracking control controller 20 is the same except that it is the same, the same reference numerals are given to the same parts, and detailed descriptions thereof are omitted.
[0110]
That is, in the third embodiment, as shown in the flowchart of FIG. 13, the process of step S9a is added to the flowchart of the first embodiment shown in FIG. That is, in step S9, the host vehicle speed Vs is the threshold value V.₂When it is detected that the distance is below the threshold value, the process proceeds to step S9a.₀It is judged whether it falls below. And the inter-vehicle distance L is a threshold value L₀Is less than, the process proceeds to S12 through steps S10 and S11, and the target inter-vehicle distance L is determined based on the relatively large F / F gain ωτ.^*And the inter-vehicle distance L is the threshold value L₀If not, the process proceeds to S15 through steps S13 and S14, and the target inter-vehicle distance L based on the relatively small F / F gain ωτ.^*Is calculated.
[0111]
Therefore, the F / F gain ωτ is set only when the preceding vehicle stops, the host vehicle speed Vs is relatively small, and the inter-vehicle distance L is short, that is, when the preceding vehicle is relatively close. Since the vehicle speed is greatly changed, the vehicle does not approach the preceding vehicle that is stopped when the host vehicle speed Vs is further increased, and the F / F gain ωτ is increased while the preceding vehicle is far away. By changing, it is possible to avoid approaching the preceding vehicle at high speed.
[0112]
Next, a fourth embodiment of the present invention will be described.
Since the fourth embodiment is the same except that the processing procedures in the inter-vehicle distance sensor 12 and the follow-up control controller 20 are different, the same reference numerals are given to the same parts, and detailed descriptions thereof are omitted.
The inter-vehicle distance sensor 12 according to the fourth embodiment is configured by a so-called known scanning distance measuring device, and scans laser light, for example, 6 ° left and right from the center in an angle range of about 12 ° and outputs it to the front of the vehicle. At the same time, the reflected light is detected, and the distance between the host vehicle and the front object is detected according to the scan angle of the laser light based on the time until the reflected light is captured, and this is output to the tracking control controller 20.
[0113]
On the other hand, the follow-up control controller 20 is configured as shown in the functional block diagram of FIG. 14, and a detection signal composed of the scan angle of the inter-vehicle distance sensor 12 and the inter-vehicle distance corresponding thereto is input to the inter-vehicle distance detection unit 30. The inter-vehicle distance detection unit 30 converts the scan angle and inter-vehicle distance into XY coordinates centered on the own vehicle by a known procedure, calculates the inter-vehicle distance L at the center of the own vehicle, and detects the center position of the front object. To do. Then, a deviation Δy between the center position of the front object stored at the previous detection and the center position of the front object at the current detection is detected. Further, the relative speed Vr is calculated by differentiating the inter-vehicle distance L.
[0114]
The preceding vehicle change detection unit 31 determines whether the preceding vehicle has been switched based on the inter-vehicle distance L, the relative speed Vr and the lateral deviation Δy calculated by the inter-vehicle distance detection unit 30, that is, whether the preceding vehicle has interrupted, It is determined whether the preceding vehicle has switched over due to catching up with the preceding vehicle or because the preceding vehicle has changed lanes. This determination is based on, for example, whether the amount of change in the inter-vehicle distance L is greater than a predetermined value, whether the amount of change in the relative speed Vr is greater than a predetermined value, or whether the lateral deviation Δy is greater than a predetermined value. Do. Then, the result is output to the target inter-vehicle distance calculation unit 34 at the time of interruption / catch-up.
[0115]
On the other hand, in the target inter-vehicle distance final value calculating unit 33, the final target inter-vehicle distance final according to the above equation (1) based on the relative speed Vr calculated by the inter-vehicle distance detecting unit 30 and the own vehicle speed Vs detected by the vehicle speed sensor 13. Value L₀ ^*Is output to the calculation unit 32 and the following target inter-vehicle distance calculation unit 35.
The calculation unit 32 calculates the inter-vehicle distance L and the target inter-vehicle distance final value L.₀ ^*Deviation LL with₀ ^*Is output to the target inter-vehicle distance calculation unit 34 at the time of the interruption / catch-up. The target inter-vehicle distance calculation unit 34 at the time of interruption / catch-up is the deviation LL₀ ^*And the relative speed Vr and the determination result of the preceding vehicle change detection unit 31, the target inter-vehicle distance L at the time of interruption / catch-up₁ ^*And target relative vehicle speed Vr^*Is calculated. Specifically, the deviation L−L when the preceding vehicle change detecting unit 31 detects the preceding vehicle change.₀ ^*And the relative speed Vr as initial values, and based on the following equation (15), the target inter-vehicle distance L at the time of interruption / catch-up₁ ^*And target relative vehicle speed Vr^*Are output to the inter-vehicle distance F / B control unit 37.
[0116]
L₁ ^*= F₁(S) ・ (LL₀ ^*) (15)
Vr^*= F₁(S) ・ L₀ ^*

On the other hand, in the following target inter-vehicle distance calculation unit 35, the target inter-vehicle distance final value L calculated by the target inter-vehicle distance final value calculation unit 33 is obtained.₀ ^*Based on the following equation (16), the following target inter-vehicle distance L₂ ^*Is output to the calculation unit 36.
[0117]
L₂ ^*= F₂(S) ・ L₀ ^*                          ...... (16)

In the calculation unit 36, the target inter-vehicle distance L at the time of the interruption / catch-up₁ ^*And target vehicle distance L following₂ ^*And add this to the target inter-vehicle distance L^*Is output to the inter-vehicle distance F / B control unit 37.
[0118]
In the inter-vehicle distance F / B control unit 37, the target relative vehicle speed Vr^*And target inter-vehicle distance L^*Based on the relative vehicle speed Vr, the inter-vehicle distance L, and the host vehicle speed Vs, the inter-vehicle distance L is set to the target inter-vehicle distance L according to the following equation (17).^*Target vehicle speed Vs to obtain a value according to^*Is calculated. In the formula, K_LAnd K_VIs the inter-vehicle distance F / B gain.
Vs^*= K_L(LL^*) + K_V(Vr-Vr^*) + Vt
Vt = Vs + Vr (17)
Target vehicle speed Vs calculated by the inter-vehicle distance F / B control unit 37^*Is input to the vehicle speed control unit 38, and the vehicle speed control unit 38 converts the host vehicle speed Vs into the target vehicle speed Vs.^*Command value Tq of drive shaft torque to obtain a value corresponding to^*Is calculated in the same manner as in the first embodiment. Then, in the drive shaft torque control unit 39, the drive shaft torque Tq^*Based on the braking pressure command value P in the same manner as in the first embodiment,_B ^*Or throttle opening command value θ^*Are output to the braking control device 8 or the engine output control device 9 as a control target.
[0119]
Next, the operation of the fourth embodiment will be described with reference to the flowchart of FIG. 15 showing the procedure of the follow-up running control process executed by the follow-up control controller 20. In this case as well, the follow-up running control process is executed as a timer interruption process every 10 msec, for example. Further, when the switch signal of the set switch 14 is OFF, or when the brake switch 19 is ON, the follow-up traveling control process is not performed.
[0120]
In the follow-up control controller 20, first, in step S31, as in the first embodiment, each detection signal of the inter-vehicle distance sensor 12, the vehicle speed sensor 13, the switch signal of the set switch 14, and the vehicle speed setting device 15 Is read and the own vehicle speed Vs and the inter-vehicle distance L are calculated. Next, the process proceeds to step S32, and the relative vehicle speed Vr between the host vehicle and the preceding vehicle is calculated by differentiating the inter-vehicle distance L calculated in step S31.
[0121]
Next, the process proceeds to step S33, and it is determined whether or not a preceding vehicle has been detected in the same manner as in the first embodiment. When no preceding vehicle is detected, the process proceeds to step S34, where the set vehicle speed Vc preset by the driver using the vehicle speed setting device 15 is set as the target vehicle speed Vs.^*Then, the process proceeds to step S42 described later.
On the other hand, when a preceding vehicle is detected in step S33, the process proceeds to step S35, and the target inter-vehicle distance final value L is calculated based on the equation (1).₀ ^*Is calculated.
[0122]
Subsequently, the process proceeds to step S36, in which it is determined whether the preceding vehicle has been replaced, that is, whether the preceding vehicle has interrupted, caught up with the preceding vehicle, or the preceding vehicle has switched due to a lane change. . This determination is made based on whether the preceding preceding vehicle has been detected from the state in which the preceding preceding vehicle has not been detected, whether the difference between the previous value and the current value of the inter-vehicle distance L is greater than or equal to a predetermined value, and the relative vehicle speed Vr. Whether the difference between the previous value and the current value of the vehicle is greater than or equal to a predetermined value, the difference between the previous value and the current value of the lateral deviation Δy from the preceding vehicle is greater than or equal to a predetermined value (for example, about 2 m corresponding to the lateral width of the vehicle) When any one of the conditions is established, it is determined that the preceding vehicle has been switched. The previous value of each parameter is stored in a predetermined storage area when the previous process is executed.
[0123]
When it is determined in step S36 that the preceding vehicle has been switched, the process proceeds to step S37, and the inter-vehicle distance L and the target inter-vehicle distance final value L when it is determined in step S36 that the preceding vehicle has been switched.₀ ^*Deviation LL with₀ ^*And relative vehicle speed Vr₀Is the secondary filter F shown in the equation (15).₁After updating and setting as the initial value of (s), the process proceeds to step S38. On the other hand, when it is determined in step S36 that the preceding vehicle has not been switched, the process proceeds to step S38 as it is.
[0124]
In this step S38, the target inter-vehicle distance L at the time of interruption / catch-up according to the equation (15).₁ ^*And target relative vehicle speed Vr^*Then, the process proceeds to step S39, and the target inter-vehicle distance L at the time of following according to the equation (16).₂ ^*Is calculated. Next, the process proceeds to step S40, and the target inter-vehicle distance L at the time of interruption / catch-up₁ ^*And target inter-vehicle distance L at the time of following₂ ^*To the target distance L^*Is calculated.
[0125]
Next, the process proceeds to step S41, and the target vehicle speed Vs is determined according to the equation (17).^*After calculating, the process proceeds to step S42. At this time, the target vehicle speed Vs calculated from the equation (17) is used.^*However, when the driving vehicle exceeds the preset vehicle speed Vc preset by the vehicle speed setting device 15, the preset vehicle speed Vc is set to the target vehicle speed Vs.^*Set as.
[0126]
In step S42, the target vehicle speed Vs is obtained in the same manner as in the first embodiment.^*The value obtained by subtracting the vehicle speed Vs from the vehicle is multiplied by the control gain, the running resistance is subtracted from this value, and this is calculated as the target torque Tq^*And
Then, the process proceeds to step S43, and the target torque Tq calculated in step S42^*Throttle opening command value θ^*And braking pressure command value P_B ^*Is output to the engine output control device 9 or the braking control device 8 to generate a braking torque or a driving torque, the timer interruption process is terminated, and the program returns to a predetermined main program.
[0127]
Therefore, it is assumed that the vehicle is currently traveling on the traveling lane in the follow-up traveling control state, and when the preceding vehicle cannot be detected in the same lane as the traveling lane of the own vehicle in this state, the process of FIG. 15 is executed. In addition, the detection signals from various sensors and the like are read (step S31) and the relative speed Vr is calculated (step S32). However, since the preceding vehicle cannot be detected, the process proceeds from step S33 to step S34. The vehicle speed setting device 15 sets the preset vehicle speed Vc in advance to the target vehicle speed Vs.^*Then, the process proceeds to step S42, and the target vehicle speed Vs is obtained in the same manner as in the first embodiment.^*Based on the vehicle speed deviation ΔV between the current vehicle speed Vs and the current vehicle speed Vs^*And the throttle opening command value θ that can generate this^*Or braking pressure command value Pb^*And the braking control device 8 or the engine output control device 9 is controlled to perform acceleration / deceleration control (step S43).
[0128]
In a state where the preceding vehicle is detected by catching up with the preceding vehicle far from the traveling lane of the own vehicle from the traveling state where there is no preceding vehicle, the process proceeds from step S33 to step S35 in FIG. From formula (1), the target inter-vehicle distance final value L₀ ^*Is calculated to detect whether or not the preceding vehicle has been replaced (step S36). In this case, the vehicle has caught up with the preceding vehicle and has changed from a state in which the vehicle has not been detected to a state in which it has been detected, so it is detected that the preceding vehicle has been replaced, and the process proceeds to step S37. Final value L₀ ^*Deviation LL between actual distance and target distance L₀ ^*Is calculated, and this is the target inter-vehicle distance L at the time of interruption / catch-up₁ ^*Is set as the initial value in the filter operation. Further, the relative vehicle speed Vr at this time is equal to the target relative vehicle speed Vr.^*Is set as the initial value in the filter operation.
[0129]
Then, based on the set initial value, the filter calculation is performed based on the equation (15), and the target inter-vehicle distance L at the time of interruption / catch-up₁ ^*And target relative vehicle speed Vr^*Is calculated (step S38), and the target inter-vehicle distance L at the time of following is further calculated based on the equation (16).₂ ^*Is calculated (step S39) and added to obtain the target inter-vehicle distance L.^*Is calculated (step S40).
[0130]
And this target inter-vehicle distance L^*And the target relative vehicle speed Vr calculated by the filter calculation^*Based on the actual inter-vehicle distance L, the relative vehicle speed Vr, and the preceding vehicle speed Vt, the target vehicle speed Vs is calculated from the equation (17).^*Is calculated (step S41), and the target vehicle speed Vs is calculated.^*And the target torque Tq that can be matched based on the vehicle speed Vs^*And brake control or engine control is performed by controlling the braking control device 8 or the engine output control device 9 based on this (steps S42 and S43).
[0131]
Then, when the preceding vehicle is captured, the preceding vehicle is detected and the preceding vehicle is not replaced, the processes of steps S33, S35, S36, and S38-43 are repeated, and the target inter-vehicle distance final at the time when the interruption occurs Value L₀ ^*And the deviation LL from the actual inter-vehicle distance L at this time₀ ^*The target inter-vehicle distance L at the time of interruption / catchup calculated by a filter operation with the initial value as₁ ^*And target vehicle distance L when following₂ ^*The target inter-vehicle distance L calculated from the sum of^*And the target relative vehicle speed Vr calculated by the filter calculation using the relative vehicle speed Vr at the time of the interruption as an initial value so that the actual inter-vehicle distance L coincides with the actual inter-vehicle distance L.^*The control is performed so that the actual relative vehicle speed Vr matches.
[0132]
Here, the target inter-vehicle distance L at the time of interruption / catchup calculated based on the equation (15) from the time when the preceding vehicle is captured.₁ ^*Is a deviation LL between the inter-vehicle distance and the target inter-vehicle distance final value as shown in FIG.₀ ^*Since is a positive value, it slowly converges from a positive value to a negative value with a second-order delay, and then converges to zero. Similarly, the target relative vehicle speed Vr^*As shown in FIG. 16 (b), since the host vehicle is faster than the preceding vehicle and the relative vehicle speed Vr is a negative value, the vehicle gradually converges from a negative value to a positive value and then converges to zero. become.
[0133]
On the other hand, the target inter-vehicle distance L at the time of following₂ ^*Is calculated according to the above equation (16) based on the preceding vehicle speed Vt, and as shown in FIG. 16 (c), the target inter-vehicle distance final value L₀ ^*It will change with a temporary delay according to the change of.
Therefore, this target inter-vehicle distance L₁ ^*And L₂ ^*Target inter-vehicle distance L calculated from the sum of^*For example, as shown in FIG. 17B, from the state where no preceding vehicle is detected, time t₁₁In this state, when the preceding vehicle is traveling at a constant speed, the target inter-vehicle distance L at the time of interruption / catch-up₁ ^*Is the inter-vehicle distance L at the time of interruption and the final target distance L at the time of interruption.₀ ^*Deviation LL with₀ ^*16 as an initial value, it gradually decreases as shown in FIG. 16 (a). However, since the preceding vehicle is traveling at a constant vehicle speed after interruption, the target inter-vehicle distance L at the time of following is determined.₂ ^*Is a constant value corresponding to the preceding vehicle speed Vt. Therefore, the target inter-vehicle distance L^*As shown in FIG. 17A, the target inter-vehicle distance L at the time of interruption^*Gradually decreases from the target distance L₂ ^*Converge to (time t₁₂).
[0134]
On the other hand, the target relative vehicle speed Vr^*Is the time t₁₁As shown in FIG. 16 (b), the relative vehicle speed Vr at the time when the preceding vehicle is captured is set as an initial value and gradually decreases. And the target inter-vehicle distance L set in this way^*And target relative vehicle speed Vr^*And the target torque Tq so that the actual inter-vehicle distance L and the relative vehicle speed Vr coincide with each other.^*Is set, and braking / driving force corresponding to this is generated. Accordingly, the inter-vehicle distance from the preceding vehicle is gradually reduced to the target inter-vehicle distance final value L.₀ ^*Will converge to.
[0135]
And from this state, time t₁₃When the preceding vehicle speed Vt decelerates, the target inter-vehicle distance L at the time of interruption / catch-up₁ ^*Has converged to zero, so the target inter-vehicle distance L^*Is the target inter-vehicle distance L₂ ^*Determined by. At this time, the target inter-vehicle distance L at the time of following₂ ^*Is the final target distance L₀ ^*That is, it decreases with a first-order lag according to the decrease of the preceding vehicle speed Vt, and the time t₁₄When the preceding vehicle speed Vt becomes constant, the target inter-vehicle distance L at the time of following₂ ^*Will quickly converge to a certain value. At this time, the target relative vehicle speed Vr^*Has converged to zero, control is performed so that the relative vehicle speed Vr becomes zero, and the inter-vehicle distance is quickly determined to be the target inter-vehicle distance final value L.₀ ^*Will converge to.
[0136]
Also, for example, time t₁₁At a time t₁₂Target distance L when interrupting or catching up with₁ ^*If the preceding vehicle speed Vt decelerates or stops before it converges to zero, the target inter-vehicle distance L at the time of following₂ ^*Changes with a first-order lag with respect to the change in the preceding vehicle speed Vt, and the target inter-vehicle distance L at the time of interruption / catch-up₁ ^*The target inter-vehicle distance final value L corresponding to the preceding vehicle speed Vt after deceleration more quickly than the response of₀ ^*The target inter-vehicle distance L₀Decreases rapidly, and the target inter-vehicle distance final value L corresponding to the preceding vehicle speed Vt after deceleration₀ ^*The target relative vehicle speed Vr^*In a state where the value does not converge to zero, the relative vehicle speed Vr is equal to the target relative vehicle speed Vr.^*Since vehicle speed control is performed so that
[0137]
Thus, when the preceding vehicle is switched, the deviation LL at the time of switching₀ ^*Target inter-vehicle distance L at the time of interruption / catch-up based on₁ ^*Target vehicle distance L₀Gently target final distance between vehicles L₀ ^*Therefore, it is possible to avoid that the host vehicle suddenly decelerates or accelerates due to following the preceding vehicle after switching. When the preceding vehicle speed Vt changes, the target inter-vehicle distance L at the time of following₂ ^*Target vehicle distance L₀, Target inter-vehicle distance L at the time of interruption / catch-up₁ ^*The target inter-vehicle distance final value L according to the preceding vehicle speed Vt after the change₀ ^*Therefore, the inter-vehicle distance L is moderated by an interruption or catch-up, etc., and the target inter-vehicle distance final value L₀ ^*Even in a state where the vehicle has converged, it is possible to promptly respond to changes in the preceding vehicle speed Vt. Therefore, the inter-vehicle distance L expected by the driver can be ensured according to the traveling state of the preceding vehicle, and the preceding vehicle can be followed without causing the driver to feel uncomfortable.
[0138]
Also, the target inter-vehicle distance L^*Target distance L when interrupting or catching up₁ ^*And target vehicle distance L when following₂ ^*Therefore, it is not necessary to switch the control constant between when the preceding vehicle changes, such as interruption or catch-up, and when following, so that control can be performed without giving a sense of discontinuity. it can.
Also, the target inter-vehicle distance L^*Target distance L when interrupting or catching up₁ ^*And target vehicle distance L when following₂ ^*Therefore, even in complex conditions where the preceding vehicle decelerates while catching up with the preceding vehicle from a distance, the target inter-vehicle distance can be calculated as expected by the driver. There is no sense of incongruity.
[0139]
Here, the inter-vehicle distance sensor 12 corresponds to the inter-vehicle distance detection means, the vehicle speed sensor 13 corresponds to the own vehicle speed detection means, the braking control device 8 and the engine output control device 9 correspond to the braking / driving force control means, FIG. The process of step S33 corresponds to the preceding vehicle presence / absence detecting means, the processes of steps S34, S41 to S43 correspond to the control means, and the process of calculating the preceding vehicle speed Vt from the equation (1) in the process of step S35 is preceded. Corresponding to the vehicle speed detection means, the target inter-vehicle distance final value L is obtained in step S35.₀ ^*Corresponds to the target inter-vehicle distance final value calculating means, the process of step S36 corresponds to the preceding vehicle change detecting means, and the process of calculating the lateral deviation Δy in the process of step S36 is the lateral distance detecting means. Correspondingly, the target inter-vehicle distance L at the time of interruption / catch-up in the process of step S38₁ ^*Is equivalent to the target inter-vehicle distance transient value calculating means, and the process of step S40 corresponds to the target inter-vehicle distance calculating means.
[0140]
Next, a fifth embodiment of the present invention will be described.
The fifth embodiment is the same as the first embodiment except that the processing procedure in the follow-up control controller 20 is different. Therefore, the same reference numerals are given to the same parts, and the detailed description thereof is omitted. Description is omitted.
FIG. 18 is a functional block diagram of the tracking control controller 20 in the fifth embodiment. As shown in the block diagram of FIG. 18, the inter-vehicle distance L between the host vehicle and the preceding vehicle is an inter-vehicle distance sensor. 12 is input to the inter-vehicle distance detector 41 to calculate the inter-vehicle distance L, and the inter-vehicle distance L is differentiated to calculate the relative speed Vr. The inter-vehicle distance L and the relative speed Vr are input to the target inter-vehicle distance / target relative vehicle speed calculation unit 42 and the inter-vehicle distance F / B control unit 43.
[0141]
The target inter-vehicle distance and target relative vehicle speed calculation unit 42 uses the relative speed Vr, the own vehicle speed Vs detected by the vehicle speed sensor 13, and the inter-vehicle distance L detected by the inter-vehicle distance sensor 12 according to the procedure described later. Distance L and target relative vehicle speed Vr^*Is calculated. These are output to the inter-vehicle distance F / B control calculation unit 43.
The inter-vehicle distance F / B control unit 43 is configured so that the target inter-vehicle distance L^*And target relative vehicle speed Vr^*Then, the relative vehicle speed Vr and the inter-vehicle distance L from the inter-vehicle distance detecting unit 41 and the own vehicle speed Vs are input, and based on these, the inter-vehicle distance L is set as the target inter-vehicle distance L.^*Target vehicle speed Vs to obtain a value according to^*Is calculated.
[0142]
This target vehicle speed Vs^*Is input to the vehicle speed control unit 44, and the vehicle speed control unit 44 converts the host vehicle speed Vs to the target vehicle speed Vs in the same manner as in the first embodiment.^*Command value Tq of drive shaft torque to obtain a value corresponding to^*Is calculated.
This drive shaft torque command value Tq^*Based on the above, the drive shaft torque control unit 45 performs the drive target braking pressure P in the same manner as in the first embodiment._B ^*Or throttle opening command value θ^*Are calculated and the braking pressure command value P is supplied to the braking control device 8 or the engine output control device 9 as the control target._B ^*Or throttle opening command value θ^*Output as.
[0143]
FIG. 19 is a block diagram showing details of the target inter-vehicle distance and target relative vehicle speed calculation unit 42. The target inter-vehicle distance and target relative vehicle speed calculation unit 42 adjusts the preceding vehicle from the own vehicle speed Vs and the relative vehicle speed Vr. A preceding vehicle acceleration / deceleration calculating unit 42a for calculating a speed α, a preceding vehicle deceleration determining unit 42b for determining whether the preceding vehicle has decelerated based on the preceding vehicle acceleration / deceleration α, an own vehicle speed Vs, a relative vehicle speed Vr, an inter-vehicle distance Distance L, target inter-vehicle distance final value L₀ ^*And an F / F gain calculation unit 42c for determining an F / F gain composed of ωτ and ζ, which will be described later, based on the determination result of the preceding vehicle deceleration determination unit 42b, the own vehicle speed Vs, the relative vehicle speed Vr, and the inter-vehicle distance L, target inter-vehicle distance final value L₀ ^*Then, based on the F / F gains ωτ and ζ from the F / F gain calculation unit 42c, the replacement of the preceding vehicle occurs based on the equation (15) as in the fourth embodiment. Inter-vehicle distance deviation LL when₀ ^*And the relative speed Vr as an initial value, the target inter-vehicle distance L at the time of interruption / catch-up that slowly converges to zero as shown in FIG.₁ ^*And target relative vehicle speed Vr^*And a target relative vehicle speed calculation unit 42d.
[0144]
The preceding vehicle acceleration / deceleration calculation unit 42a calculates the preceding vehicle speed Vt from the host vehicle speed Vs and the relative speed Vr, and calculates the preceding vehicle acceleration / deceleration α based on the following equation (18).

Vt = Vs + Vr
In the F / F gain calculation unit 42c, the host vehicle speed Vs, the relative vehicle speed Vr, the inter-vehicle distance L, and the target inter-vehicle distance final value L calculated in the same manner as the equation (1).₀ ^*Based on the determination result of the preceding vehicle deceleration determination unit 42b, the target inter-vehicle distance L at the time of interruption / catch-up₁ ^*And target relative vehicle speed Vr^*F / F gains that are ζ and ωτ in the equation (15) for calculating the above are set. That is, in the preceding vehicle deceleration determination unit 42b, the target inter-vehicle distance final value L when the preceding vehicle is replaced is generated.₀ ^*Deviation LL between vehicle distance L₀ ^*(= L_ERR0) And F / F gains ζ and ωτ corresponding to) are calculated based on, for example, FIG. 7, FIG. 9, and FIG. The F / F gains ζ and ωτ are not limited to those shown in FIGS. 7, 9 and 20, and can be arbitrarily set.
[0145]
FIG. 20 is a gain map for setting the F / F gain ωτ, similar to FIG._ERR0And the relative speed Vr. The F / F gain ω is the inter-vehicle distance deviation L_ERR0Increases from zero to the negative direction, i.e., tends to increase as the preceding vehicle and the host vehicle approach, and tends to decrease as the leading vehicle increases from the positive direction, i.e., as the preceding vehicle and the host vehicle move away from each other. Is set. The relative speed Vr increases from zero to the negative direction and is set to increase as the host vehicle and the preceding vehicle tend to approach each other, and the relative speed Vr increases from zero to the positive direction. It is set to a tendency to become smaller as the preceding vehicle tends to move away. Further, the F / F gain ωτ in FIG. 20 is set to be larger than the F / F gain ωτ under the same conditions in FIG.
[0146]
In FIG. 20, the inter-vehicle distance deviation L_ERR0And a plurality of relative speeds Vr are set stepwise, and the F / F gain is set for the representative values of the inter-vehicle distance deviation and the relative speed._ERR0The F / F gain corresponding to the representative value of the intervehicular distance deviation and the relative speed that is closest to the relative speed Vr is expressed as the actual intervehicular distance deviation L._ERR0And an F / F gain corresponding to the relative speed Vr.
[0147]
Note that the F / F gain may be changed continuously instead of stepwise.
Further, the case where the gain map is stored in a predetermined storage area is described, but the relationship between the inter-vehicle distance deviation and the relative speed and the F / F gain ζ, the inter-vehicle distance deviation and the relative speed, It may be stored as a function expression representing the relationship with the F / F gain ωτ, and the F / F gains ζ and ωτ may be set based on this function expression.
[0148]
In the target inter-vehicle distance target relative vehicle speed calculation unit 42d, the F / F gain ζ, ωτ, the host vehicle speed Vs, the relative vehicle speed Vr, the inter-vehicle distance L, and the final target inter-vehicle distance value L.₀ ^*Based on the above, the target inter-vehicle distance L at the time of interruption / catch-up is calculated based on the equation (15) in the same manner as in the fourth embodiment.₁ ^*And target relative vehicle speed Vr^*And the target inter-vehicle distance L at the time of interruption / catch-up₁ ^*And target inter-vehicle distance final value L₀ ^*And the target inter-vehicle distance L according to the following equation (19)^*Is calculated.
[0149]
L^*= L₀ ^*+ L₁ ^*                                ...... (19)
And this target inter-vehicle distance L^*And target relative vehicle speed Vr^*And the target vehicle speed Vs according to the equation (17) based on the inter-vehicle distance L and the relative vehicle speed Vr.^*Is calculated. Next, the operation of the fifth embodiment will be described with reference to the flowchart of FIG. 21 showing the procedure of the follow-up running control process executed by the follow-up control controller 20. In this case as well, the follow-up running control process is executed as a timer interruption process every 10 msec, for example. Further, it is not performed when the switch signal of the set switch 14 is OFF, or when it is determined that the brake switch 19 is ON, that is, the brake pedal 8a is depressed. In addition, a flag F used during processing₁~ F_ThreeIs set to zero as the initial value at startup.
[0150]
In the follow-up control controller 20, first, in step S51, as in the first embodiment, the detection signals of the inter-vehicle distance sensor 12, the vehicle speed sensor 13, the switch signal of the set switch 14, and the vehicle speed setting device 15 Is read and the own vehicle speed Vs and the inter-vehicle distance L are calculated. Next, the process proceeds to step S52, and the relative vehicle speed Vr between the host vehicle and the preceding vehicle is calculated by differentiating the inter-vehicle distance L calculated in step S51.
[0151]
Next, the process proceeds to step S53, and it is determined whether or not a preceding vehicle has been detected in the same manner as in the first embodiment. When no preceding vehicle is detected, the process proceeds to step S54, where the flag F₁And F₂And F_ThreeF₁= 0, F₂= 0, F_ThreeAfter setting = 0, the process proceeds to step S72 described later. On the other hand, when there is a preceding vehicle, the process proceeds to step S55.
[0152]
In this step S55, it is determined whether or not the vehicle is traveling at a constant inter-vehicle time as in the first embodiment. When it is determined that the vehicle is not traveling at a constant inter-vehicle time, the process proceeds to step S56, and the flag F₁Is F₁When it is determined that = 1, the process proceeds to step S57 where the inter-vehicle distance L and the target inter-vehicle distance final value L₀ ^*Distance from vehicle distance L_ERR0Is calculated. And this inter-vehicle distance deviation L_ERR0After the relative speed Vr calculated in step S52 is stored in a predetermined storage area, the process proceeds to step S58. In step S56, the flag F₁Is F₁If not = 1, the process proceeds to step S58.
[0153]
In this step S58, the preceding vehicle acceleration / deceleration α is calculated based on the equation (18), and then the process proceeds to step S59, where the preceding vehicle acceleration / deceleration α is considered that the preceding vehicle is decelerating rapidly. Possible threshold α₁(For example, -1.0 m / s²When it is determined that the value of the flag F₂Is F₂Determine if = 1. And flag F₂Is F₂If not = 1, the process proceeds to step S61, and the inter-vehicle distance deviation L calculated in step S57 is performed._ERR0And F / F gains ζ and ωτ corresponding to the relative speed Vr calculated in step S52 are set according to the gain maps shown in FIGS. 7 and 20, for example. And flag F is set to F₂After setting = 1, the process proceeds to step S62 described later. Flag F in step S60₂Is F₂When = 1, the process proceeds to step S62 as it is.
[0154]
On the other hand, in step S59, the preceding vehicle acceleration / deceleration α is set to the threshold α.₁When it is determined that the value does not fall below, the process proceeds to step S63 and the flag F_ThreeIs F_Three= 1 and flag F_ThreeIs F_ThreeIf not = 1, the process proceeds to step S64, and the inter-vehicle distance deviation L calculated in step S57._ERR0And F / F gains ζ and ωτ corresponding to the relative speed Vr calculated in step S2 are set according to the gain maps shown in FIGS. 7 and 9, for example. And flag F_ThreeF_ThreeAfter setting = 1, the process proceeds to step S65. In step S63, the flag F_ThreeIs F_ThreeWhen = 1, the process proceeds to step S65 as it is.
[0155]
On the other hand, when it is determined in step S55 that the vehicle is traveling at a constant inter-vehicle time, the process proceeds to step S66, where each flag F₁~ F_ThreeF₁= 0, F₂= 0, F_ThreeAfter setting = 0, the process proceeds to step S67.
In step S62, the F / F gains ζ and ωτ set from the gain maps shown in FIGS. 7 and 20 in the process of step S61, and the inter-vehicle distance deviation L calculated in step S57._ERR0And the target inter-vehicle distance final value L calculated by the equation (2) based on the preceding vehicle speed Vt₀ ^*Based on the above, the target inter-vehicle distance L according to the equations (15) and (19)^*And target relative vehicle speed Vr^*Is calculated.
[0156]
In step S65, the F / F gains ζ and ωτ set from the gain maps shown in FIGS. 7 and 9 in the process of step S64, and the inter-vehicle distance deviation L calculated in step S57._ERR0And the target inter-vehicle distance final value L calculated by the equation (1) based on the preceding vehicle speed Vt₀ ^*Based on the above, the target inter-vehicle distance L according to the equations (15) and (19)^*And target relative vehicle speed Vr^*Is calculated.
[0157]
In step S67, the target inter-vehicle distance final value L based on the equation (1).₀ ^*And calculate this as the target inter-vehicle distance L^*Set as. Also, the target relative vehicle speed Vr^*Is set to zero.
In this way, in steps S62, S65, and S67, the target inter-vehicle distance L^*And target relative vehicle speed Vr^*Is calculated, the process proceeds to step S72. Then, according to the equation (17), the target vehicle speed Vs^*Is calculated.
[0158]
The calculated target vehicle speed Vs^*Is larger than the set vehicle speed Vc set by the vehicle speed setting device 15, the set vehicle speed Vc is set to the target vehicle speed Vs.^*And
Next, the process proceeds to step S73, where the target vehicle speed Vs^*Based on the target torque Tq as described above.^*Next, the process proceeds to step S74 and the target torque Tq calculated in step S73 is calculated.^*Throttle opening command value θ^*And braking pressure command value P_B ^*Is output to the engine output control device 9 or the braking control device 8 to generate a braking torque or a driving torque, the timer interruption process is terminated, and the program returns to a predetermined main program.
[0159]
Therefore, it is assumed that the vehicle is currently traveling on the traveling lane in the follow-up traveling control state, and when the preceding vehicle cannot be detected in the same lane as the traveling lane of the own vehicle in this state, the processing of FIG. 21 is executed. In addition, the detection signals from various sensors are read (step S51) and the relative speed Vr is calculated (step S52). However, since the preceding vehicle cannot be detected, the process proceeds from step S53 to step S54 to step S55. The set vehicle speed Vc preset by the driver using the vehicle speed setting device 15 is set to the target vehicle speed Vs.^*Then, the process proceeds to step S72, and in the same manner as in the first embodiment, the target vehicle speed Vs^*Based on the vehicle speed deviation ΔV between the current vehicle speed Vs and the current vehicle speed Vs^*And the throttle opening command value θ that can generate this^*Or braking pressure command value Pb^*And the braking control device 8 or the engine output control device 9 is controlled to perform acceleration / deceleration control (steps S73 and S74).
[0160]
In a state where the preceding vehicle is detected by catching up with the preceding vehicle far from the traveling lane of the own vehicle from the traveling state where there is no preceding vehicle, the process proceeds from step S53 to step S55 in FIG. From formula (1), the target inter-vehicle distance final value L₀ ^*Is calculated, and it is detected whether the vehicle is traveling in a certain inter-vehicle time, that is, whether the preceding vehicle has been switched. In this case, since the vehicle has caught up with the preceding vehicle and is not traveling in a certain inter-vehicle time, the process proceeds from step S55 to step S56 to step S57, and the target inter-vehicle distance final value L at this time₀ ^*Distance deviation L, which is the deviation between vehicle distance L_ERR0Further, the acceleration / deceleration α of the preceding vehicle is calculated according to the equation (18) (step S58).
[0161]
At this time, when the preceding vehicle is not decelerating, the preceding vehicle acceleration / deceleration α is equal to the threshold α₁Therefore, the process proceeds from step S59 to step S64 through step S63, and the inter-vehicle distance deviation L calculated in step S57._ERR0And the corresponding F / F gains ζ and ωτ are detected from FIGS. 7 and 9 based on the relative velocity Vr calculated in step S52. The F / F gains ζ and ωτ are applied to the equation (15), and the inter-vehicle distance deviation L at the time when the change of the preceding vehicle is detected._ERR0Target distance L when interrupting or catching up₁ ^*Target inter-vehicle distance L at the time of interruption / catch-up as an initial value in the filter calculation of₁ ^*And this and the target inter-vehicle distance final value L₀ ^*And the target inter-vehicle distance L according to the equation (19)^*Is calculated.
[0162]
And this target inter-vehicle distance L^*And the target relative vehicle speed Vr calculated by the filter calculation^*Based on the actual inter-vehicle distance L, the relative vehicle speed Vr, and the preceding vehicle speed Vt, the target vehicle speed Vs is calculated from the equation (17).^*Is calculated (step S72) and the target vehicle speed Vs is calculated.^*And the target torque Tq that can be matched based on the vehicle speed Vs^*And brake control or engine control is performed by controlling the braking control device 8 or the engine output control device 9 based on this (steps S73, S74).
[0163]
Then, when the preceding vehicle is captured, the preceding vehicle is detected and the preceding vehicle is not replaced, and the preceding vehicle is not decelerated, the processes of steps S53, S55, S56, S58, S59, S63, S65, and S72 to S74 are performed. Is repeated and the target inter-vehicle distance final value L at the time of interruption₀ ^*And the deviation LL from the actual inter-vehicle distance L at this time₀ ^*The target inter-vehicle distance L at the time of interruption / catchup calculated by a filter operation with the initial value as₁ ^*The target inter-vehicle distance L calculated from the sum of^*And the target relative vehicle speed Vr calculated by the filter calculation using the relative vehicle speed Vr at the time of the interruption as an initial value so that the actual inter-vehicle distance L coincides with the actual inter-vehicle distance L.^*The control is performed so that the actual relative vehicle speed Vr matches.
[0164]
Therefore, as shown in FIG._{twenty one}When catching up with, the target inter-vehicle distance final value L at the time of catching up₀ ^*The target inter-vehicle distance L at the time of interruption / catch-up calculated based on the deviation between the inter-vehicle distance L and the inter-vehicle distance L₁ ^*16 gradually converges to zero as shown in FIG. 16 (a), so the target inter-vehicle distance L^*As shown in FIG. 22 (a), the target inter-vehicle distance final value L gently₀ ^*And the target relative vehicle speed Vr as shown in FIG.^*Since the vehicle gradually converges to zero, the host vehicle slowly catches up with the preceding vehicle without sudden acceleration / deceleration.
[0165]
And time t_{twenty two}In step S55, the vehicle shifts from step S55 to step S66 and the target inter-vehicle distance final value L corresponding to the vehicle speed Vt of the preceding vehicle is reached.₀ ^*The target inter-vehicle distance L^*It shifts to the running state in the fixed inter-vehicle time.
Then, from the traveling state in this fixed inter-vehicle time, the time t_{twenty three}The preceding vehicle decelerates at step S55 to step S58, and the preceding vehicle acceleration / deceleration α calculated here is the threshold value α.₁If it becomes smaller, the process proceeds from step S59 to step S60, and the inter-vehicle distance deviation L at the time when the preceding vehicle is switched._ERR0The F / F gains ζ and ωτ in the equation (15) in the filter processing calculation with the initial value as the initial value are stored in a predetermined storage area as L_ERR0And the F / F gains ζ and ωτ specified from FIG. 7 and FIG. 20 on the basis of the relative speed Vr, and subsequently the target inter-vehicle distance L based on the updated F / F gain.₁ ^*And target relative speed Vr^*Is calculated. And this target inter-vehicle distance L₁ ^*Based on the target inter-vehicle distance L^*And the target relative speed Vr^*Control based on the above.
[0166]
At this time, the F / F gain ωτ in FIG. 20 is the inter-vehicle distance deviation L in FIG._ERR0And relative speed Vr^*Is greater than the F / F gain under the same conditions, so the time t when the preceding vehicle decelerates_{twenty three}The target inter-vehicle distance L at the time of interruption / catch-up₁ ^*The degree of convergence to zero becomes larger. Therefore, as shown in FIG. 22 (a), the target inter-vehicle distance L^*Will converge quickly with respect to the deceleration of the preceding vehicle.
[0167]
In other words, even if the inter-vehicle distance changes greatly and the vehicle does not travel in a certain inter-vehicle time, when the inter-vehicle distance changes due to the change of the preceding vehicle, the preceding vehicle gradually catches up. When the inter-vehicle distance changes due to the deceleration of the vehicle, the F / F gain is further increased and the target inter-vehicle distance L₁ ^*Since the degree of convergence is increased, it is possible to promptly follow the vehicle that has been decelerated.
[0168]
Further, as shown in FIG. 23, the time point t catches up with the preceding vehicle (FIG. 23A) traveling at a constant vehicle speed.₃₁At time t₃₁Inter-vehicle distance deviation L_ERR0The target inter-vehicle distance L is filtered using₁ ^*And target inter-vehicle distance final value L₀ ^*Target inter-vehicle distance L consisting of^*Control is performed based on (FIG. 23 (b)), and the vehicle is slowly catching up with the preceding vehicle without sudden acceleration / deceleration as shown in FIG. 23 (c).₃₂The preceding vehicle decelerates and its acceleration α is the threshold α₁Is smaller than the target inter-vehicle distance L₁ ^*The F / F gain ωτ in the calculation formula is set to a larger value than before, that is, the target inter-vehicle distance L at the time of interruption / catch-up₁ ^*The degree of convergence of becomes larger. Therefore, as shown in FIG. 23 (b), the target inter-vehicle distance L^*Is the final target distance L₀ ^*As a result, the inter-vehicle distance L can be quickly obtained without the sudden acceleration / deceleration.₀ ^*Will converge to.
[0169]
On the other hand, even when the preceding vehicle decelerates, the target inter-vehicle distance L is based on the same F / F gain as before.₁ ^*If the preceding vehicle is decelerated as shown in FIG. 24 (FIG. 24A), the target inter-vehicle distance L is calculated.₁ ^*Converges with the same degree of convergence as before (FIG. 24B). Accordingly, the inter-vehicle distance L decreases as the preceding vehicle decelerates, and the target inter-vehicle distance L₁ ^*Before the vehicle converges to zero^*Below (time t₄₁), The host vehicle decelerates rapidly, but at this point, the inter-vehicle distance L is still the target inter-vehicle distance L₀ ^*Thus, unnecessary deceleration is performed. In particular, when the preceding vehicle decelerates in a distant state, vehicle speed control that does not meet the driver's intention is performed, which gives a sense of incongruity.
[0170]
However, when the preceding vehicle decelerates, the target inter-vehicle distance L₁ ^*By changing the F / F gain for calculating the value to a larger value and enhancing the response characteristics, the inter-vehicle distance L becomes the target inter-vehicle distance final value L₀ ^*There is no unnecessary deceleration before reaching, and the driver does not feel uncomfortable.
Further, by changing the F / F gain ωτ, the target inter-vehicle distance L^*The target inter-vehicle distance final value L₀ ^*Therefore, it can be easily realized without significantly changing the configuration of the tracking control device.
[0171]
When the switching of the preceding vehicle is detected, the target inter-vehicle distance final value L at the time of switching₀ ^*Deviation L between vehicle distance L_ERR0Approximate the vehicle behavior of the own vehicle at the time of switching based on the second order transfer function, and this and the target inter-vehicle distance final value L₀ ^*Based on the target distance L^*Therefore, the appropriate target inter-vehicle distance L in consideration of actual vehicle behavior is set.^*Can be set.
[0172]
Further, the final value L of the target inter-vehicle distance at the time when the F / F gains ζ and ωτ are detected as the replacement of the preceding vehicle is detected.₀ ^*Deviation L between vehicle distance L_ERR0And the relative vehicle speed Vr, the appropriate target inter-vehicle distance L according to the relative relationship between the host vehicle and the preceding vehicle at the time of replacement.^*Can be set.
Here, the inter-vehicle distance sensor 12 corresponds to the inter-vehicle distance detection means, the vehicle speed sensor 13 corresponds to the own vehicle speed detection means, the braking control device 8 and the engine output control device 9 correspond to the braking / driving force control means, FIG. In step S55 corresponds to the preceding vehicle change detection means, and in step S57, the target inter-vehicle distance final value L₀ ^*In step S59 corresponds to the preceding vehicle deceleration detection means, and in step S62 and S65, the target inter-vehicle distance L at the time of interruption / catch-up is calculated.₁ ^*The processing for calculating the target inter-vehicle distance transient value calculating means corresponds to the target inter-vehicle distance transient value calculating means, the processing of steps S72 to S74 corresponds to the control means, and the target inter-vehicle distance L in the processing of steps S62, S65, and S67.^*The processing for calculating the distance corresponds to the target inter-vehicle distance calculation means.
[0173]
Next, a sixth embodiment of the present invention will be described.
Since the sixth embodiment is the same as the fourth embodiment except that the processing procedure in the follow-up control controller 20 is different, the same reference numerals are given to the same parts, and the detailed description thereof is omitted. Description is omitted.
That is, in the sixth embodiment, as shown in the flowchart of FIG. 25, the process of step S59a is added to the flowchart of the fifth embodiment of FIG. That is, in step S59, the preceding vehicle acceleration / deceleration α is set to the threshold value α.₁If it is not smaller, the process proceeds to step S63, but the preceding vehicle acceleration / deceleration α is equal to the threshold α.₁If it is smaller, the process proceeds to step S59a, where the inter-vehicle distance L to the target inter-vehicle distance final value L₀ ^*It is determined whether or not the value obtained by subtracting is greater than the threshold value ΔL. The threshold value ΔL is equal to the target inter-vehicle distance L when the preceding vehicle is far away.^*The target inter-vehicle distance final value L₀ ^*It is a value that can be considered that deceleration does not occur by converging to, and is, for example, about 10 m.
[0174]
And LL₀ ^*If> ΔL, the process proceeds to step S60 and the F / F gain is changed to a large value.₀ ^*When it is not> ΔL, the process proceeds to step S63 and the F / F gain is not changed.
Here, the preceding vehicle acceleration / deceleration α is the threshold α₁Target vehicle distance L when below^*The target inter-vehicle distance final value L₀ ^*The distance between the vehicles is the final value of the target vehicle distance.₀ ^*When the vehicle speed is sufficiently larger than that, when the preceding vehicle decelerates and the inter-vehicle distance L decreases, the F / F gain is set to a larger value and the target inter-vehicle distance L^*The target inter-vehicle distance final value L₀ ^*The target vehicle distance L^*If the vehicle speed is reduced, the host vehicle will not decelerate. On the other hand, the inter-vehicle distance L is the target inter-vehicle distance final value L.₀ ^*Is not sufficiently large, that is, the vehicle is relatively close and the target inter-vehicle distance final value L from the inter-vehicle distance L₀ ^*When the value obtained by subtracting is not larger than the threshold value ΔL, the process proceeds from step S59a to step S63, and the F / F gain is not changed. Accordingly, the inter-vehicle distance L decreases as the preceding vehicle decelerates, and the own vehicle also decelerates. Therefore, when the preceding vehicle that is relatively approaching decelerates, the own vehicle also decelerates, and driving No discomfort to the person.
[0175]
Needless to say, the same effects as those of the fifth embodiment can be obtained.
In each of the above embodiments, the inter-vehicle distance L and the target inter-vehicle distance L^*However, the present invention is not limited to this. For example, the inter-vehicle time obtained by dividing the inter-vehicle distance L by the own vehicle speed Vs is the same as that of the preceding vehicle. The present invention can be applied even when the follow-up control is performed so as to follow the preceding vehicle by controlling the vehicle speed of the host vehicle so that the target inter-vehicle time according to the traveling state with the vehicle is reached. In this case, when the preceding vehicle is switched at the time of interruption or catch-up, the target inter-vehicle time is corrected so that the inter-vehicle time gradually converges to the target inter-vehicle time, and when the preceding vehicle stops, the inter-vehicle time is It is sufficient to make it converge quickly.
[0176]
In each of the above embodiments, the case where the present invention is applied to a rear wheel drive vehicle has been described. However, the present invention is not limited to this, and the present invention can also be applied to a front wheel drive vehicle or a four wheel drive vehicle.
In each of the above-described embodiments, the case where the tracking control controller 20 performs arithmetic processing by software has been described. However, the present invention is not limited to this, and a function generator, a comparator, an arithmetic unit, and the like are combined. You may make it comprise the hardware which consists of the comprised electronic circuit.
[0177]
Further, although the case where the disc brake 7 is applied as the brake actuator has been described, the present invention is not limited to this, and other actuators such as a drum brake can be applied, and of course, the electrical control is performed in addition to the braking pressure. It is also possible to apply a brake actuator to be applied, in which case the target braking pressure P_B ^*Instead, a command value such as a target current may be calculated and output to the braking control device 8 that controls the brake actuator based on the command value.
[0178]
Further, although the case where the engine 2 is applied as the rotational drive source has been described, the present invention is not limited to this, and an electric motor can also be applied. Furthermore, the hybrid specification vehicle using the engine and the electric motor can be applied. It is also possible to apply.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention.
FIG. 2 is a block diagram showing a functional configuration of a follow-up control controller.
3 is a block diagram illustrating a functional configuration of a target inter-vehicle distance and target relative vehicle speed calculation unit 23 in FIG. 2;
FIG. 4 is a block diagram showing a configuration of a vehicle speed control system.
5 is a block diagram showing a functional configuration of a drive shaft torque control unit 26 of FIG. 2. FIG.
FIG. 6 is a flowchart showing an example of a procedure of a follow-up running control process in the follow-up control controller.
FIG. 7 is a gain map for setting an F / F gain ζ.
FIG. 8 is a gain map for setting an F / F gain ωτ.
FIG. 9 is a gain map for setting an F / F gain ωτ.
FIG. 10 is an explanatory diagram for explaining the operation of the first embodiment;
FIG. 11 is an explanatory diagram for explaining a conventional operation.
FIG. 12 is a flowchart illustrating an example of a processing procedure of a follow-up travel control process in the second embodiment.
FIG. 13 is a flowchart illustrating an example of a processing procedure of a follow-up travel control process according to the third embodiment.
FIG. 14 is a block diagram illustrating a functional configuration of a tracking control controller according to a fourth embodiment.
FIG. 15 is a flowchart illustrating an example of a processing procedure of a follow-up travel control process in the fourth embodiment.
FIG. 16 is an explanatory diagram for explaining the operation of the fourth embodiment;
FIG. 17 is an explanatory diagram for explaining the operation of the fourth embodiment;
FIG. 18 is a block diagram illustrating a functional configuration of a follow-up control controller according to a fifth embodiment.
19 is a block diagram illustrating a functional configuration of a target inter-vehicle distance and target relative vehicle speed calculation unit 42 in FIG. 18;
FIG. 20 is a gain map for setting an F / F gain ωτ in the fifth embodiment.
FIG. 21 is a flowchart illustrating an example of a processing procedure of a follow-up travel control process in the fifth embodiment.
FIG. 22 is an explanatory diagram for explaining the operation of the fifth embodiment;
FIG. 23 is an explanatory diagram for explaining the operation of the fifth embodiment;
FIG. 24 is an explanatory diagram for explaining a conventional operation.
FIG. 25 is a flowchart illustrating an example of a processing procedure of a follow-up travel control process in the sixth embodiment.
[Explanation of symbols]
2 Engine
7 Disc brake
8 Braking control device
9 Engine output control device
11 Throttle valve
12 Inter-vehicle distance sensor
13 Vehicle speed sensor
14 Set switch
15 Vehicle speed setting device
16 Throttle opening sensor
17 Engine rotation speed sensor
18 Torque converter output rotation speed sensor
19 Brake switch
20 Tracking control controller

Claims (12)

Own vehicle speed detecting means for detecting the speed of the own vehicle;
Preceding vehicle speed detecting means for detecting the speed of the preceding vehicle;
An inter-vehicle distance detection means for detecting an actual inter-vehicle distance between the preceding vehicle and the host vehicle;
Target inter-vehicle distance setting means for setting a target inter-vehicle distance between the preceding vehicle and the host vehicle;
Braking / driving force control means for adjusting the braking force and driving force of the host vehicle;
The braking / driving force control means is controlled according to the own vehicle speed detected by the own vehicle speed detecting means so that the actual inter-vehicle distance detected by the inter-vehicle distance detecting means matches the target inter-vehicle distance set by the target inter-vehicle distance setting means. A vehicle follow-up running control device comprising:
The target inter-vehicle distance setting means; at least a target inter-vehicle distance calculating means for calculating the target inter-vehicle distance based on a preceding vehicle speed detected by the preceding vehicle speed detecting means;
Preceding vehicle change detection means for detecting a change of the preceding vehicle;
Preceding vehicle stop detection means for detecting a stop of the preceding vehicle;
When the preceding vehicle change detecting means detects that the preceding vehicle has changed, the target inter-vehicle distance is corrected so that the actual inter-vehicle distance gradually matches the target inter-vehicle distance, and the target inter-vehicle distance is being corrected. And a correction means for correcting the target inter-vehicle distance so that the actual inter-vehicle distance quickly matches the target inter-vehicle distance when it is detected that the preceding vehicle has stopped. Control device. Own vehicle speed detecting means for detecting the speed of the own vehicle;
Preceding vehicle speed detecting means for detecting the speed of the preceding vehicle;
An inter-vehicle distance detection means for detecting an actual inter-vehicle distance between the preceding vehicle and the host vehicle;
Target inter-vehicle distance final value calculating means for calculating a target inter-vehicle distance final value based on at least the preceding vehicle speed detected by the preceding vehicle speed detecting means;
Preceding vehicle change detection means for detecting a change of the preceding vehicle;
Preceding vehicle stop detection means for detecting a stop of the preceding vehicle;
Transient target inter-vehicle distance calculating means for calculating a transient target inter-vehicle distance that gradually converges to the final target inter-vehicle distance based on the actual inter-vehicle distance at the time when the change of the preceding vehicle is detected by the preceding vehicle changing means;
The target inter-vehicle distance final value is set as the target inter-vehicle distance during steady follow-up, and the transitional target inter-vehicle distance is set as the target inter-vehicle distance instead of the target inter-vehicle distance final value when it is detected that the preceding vehicle has changed. Target inter-vehicle distance setting means,
Braking / driving force control means for adjusting the braking force and driving force of the host vehicle;
The braking / driving force control means is controlled according to the own vehicle speed detected by the own vehicle speed detection means so that the actual inter-vehicle distance detected by the inter-vehicle distance detection means matches the target inter-vehicle distance set by the target inter-vehicle distance setting means. A vehicle follow-up travel control device comprising:
The transient target inter-vehicle distance calculating means quickly converges the transient target inter-vehicle distance to the target inter-vehicle distance final value when the preceding vehicle stop detecting means detects that the preceding vehicle has stopped. A vehicle follow-up travel control device. The transient target inter-vehicle distance calculation means detects the stop of the preceding vehicle and at least when the own vehicle speed is a predetermined value or less or the actual inter-vehicle distance is a predetermined value or less, the transient target inter-vehicle distance is calculated as the target inter-vehicle distance. 3. The vehicle follow-up travel control apparatus according to claim 2, wherein the vehicle follow-up travel control apparatus is adapted to quickly converge to the final distance value. The transient target inter-vehicle distance calculating means calculates the transient target inter-vehicle distance based on a convergence gain, and when detecting the stop of the preceding vehicle, the transient target inter-vehicle distance is calculated by increasing the convergence gain than when the preceding vehicle is not stopped. 4. The vehicle follow-up travel control device according to claim 2, wherein the degree of convergence is increased. The convergence gain is set based on a deviation between the target inter-vehicle distance final value and the actual inter-vehicle distance and a relative vehicle speed between the preceding vehicle and the host vehicle when a change in the preceding vehicle is detected. The vehicle follow-up travel control device according to claim 4. 2. The preceding vehicle stop detection unit is configured to determine that the preceding vehicle is stopped when a preceding vehicle speed detected by the preceding vehicle speed detection unit is a predetermined value or less. The vehicle follow-up travel control device according to any one of claims 5 to 5. Own vehicle speed detecting means for detecting the speed of the own vehicle;
Preceding vehicle speed detecting means for detecting the speed of the preceding vehicle;
An inter-vehicle distance detection means for detecting an actual inter-vehicle distance between the preceding vehicle and the host vehicle;
Preceding vehicle change detection means for detecting a change of the preceding vehicle;
Target inter-vehicle distance final value calculating means for calculating a target inter-vehicle distance final value based on at least the preceding vehicle speed detected by the preceding vehicle speed detecting means;
Target inter-vehicle distance that calculates a target inter-vehicle distance transient value that gradually converges to zero based on a deviation between the actual inter-vehicle distance and the target inter-vehicle distance final value at the time when the preceding vehicle change detection means detects the change of the preceding vehicle. A distance transient calculation means;
Target inter-vehicle distance calculation means for calculating a target inter-vehicle distance between the preceding vehicle and the host vehicle based on the sum of the target inter-vehicle distance final value and the target inter-vehicle distance transient value;
Braking / driving force control means for adjusting the braking force and driving force of the host vehicle;
The braking / driving force control means is controlled according to the own vehicle speed detected by the own vehicle speed detection means so that the actual inter-vehicle distance detected by the inter-vehicle distance detection means matches the target inter-vehicle distance calculated by the target inter-vehicle distance calculation means. A vehicle follow-up travel control device comprising:
The target inter-vehicle distance calculating means calculates the target inter-vehicle distance so that a response characteristic of the host vehicle with respect to the final target inter-vehicle distance value is faster than a response characteristic with respect to the target inter-vehicle distance transient value. Follow-up running control device. The preceding vehicle change detection means detects a change in the actual inter-vehicle distance detected by the inter-vehicle distance detection means when the preceding vehicle presence / absence detection means for detecting the presence / absence of the preceding vehicle is detected from a state in which the preceding vehicle is not detected. When the amount exceeds the reference value, when the amount of change in the relative vehicle speed detected by the relative vehicle speed detecting means for detecting the relative vehicle speed between the preceding vehicle and the own vehicle amount exceeds the reference value, the preceding vehicle and the own vehicle When the amount of change in the lateral distance detected by the lateral distance detecting means for detecting the lateral distance from the vehicle exceeds a reference value, it is determined that the preceding vehicle has changed when at least one of the following holds: The vehicle follow-up travel control device according to claim 7, wherein the vehicle follow-up travel control device is configured as described above. Own vehicle speed detecting means for detecting the speed of the own vehicle;
An inter-vehicle distance detection means for detecting an actual inter-vehicle distance between the preceding vehicle and the host vehicle;
Target inter-vehicle distance calculating means for calculating a target inter-vehicle distance between the preceding vehicle and the host vehicle;
Braking / driving force control means for adjusting the braking force and driving force of the host vehicle;
The braking / driving force control means is controlled according to the own vehicle speed detected by the own vehicle speed detection means so that the actual inter-vehicle distance detected by the inter-vehicle distance detection means matches the target inter-vehicle distance calculated by the target inter-vehicle distance calculation means. A vehicle follow-up travel control device comprising:
The target inter-vehicle distance calculation means includes preceding vehicle change detection means for detecting a change in the preceding vehicle,
Preceding vehicle deceleration detection means for detecting deceleration of the preceding vehicle;
Target inter-vehicle distance final value calculating means for calculating a target inter-vehicle distance final value based on at least the preceding vehicle speed detected by the preceding vehicle speed detecting means;
A target inter-vehicle distance transient value that gradually converges to zero based on a deviation between the actual inter-vehicle distance and the final target inter-vehicle distance value at the time when the preceding vehicle change detecting means detects the change of the preceding vehicle. A distance transient value calculating means,
The target inter-vehicle distance is calculated based on a sum of the target inter-vehicle distance final value and the target inter-vehicle distance transient value, and the target inter-vehicle distance is calculated as the target inter-vehicle distance when the preceding vehicle deceleration detecting unit detects deceleration of the preceding vehicle. A vehicle follow-up travel control device that quickly converges to a final inter-vehicle distance value. The target inter-vehicle distance calculating means detects the deceleration of the preceding vehicle and quickly sets the target inter-vehicle distance to the target inter-vehicle distance final value when the actual inter-vehicle distance is larger than the final target inter-vehicle distance by a predetermined value or more. The vehicle follow-up travel control device according to claim 9, wherein the vehicle follow-up travel control device is converged. The target inter-vehicle distance transient value calculation means calculates the target inter-vehicle distance transient value based on a convergence gain, and when the deceleration of the preceding vehicle is detected, the convergence degree of the convergence gain is larger than when the preceding vehicle is not decelerating. The vehicle follow-up travel control device according to claim 9 or 10, wherein the vehicle follow-up travel control device is configured as described above. The convergence gain is set based on a deviation between the target inter-vehicle distance final value and the actual inter-vehicle distance and a relative vehicle speed between the preceding vehicle and the host vehicle when a change in the preceding vehicle is detected. The vehicle follow-up travel control device according to claim 11.

Images