JP3743327B2 - Integrated control device for vehicle - Google Patents

Description

次いで、ステップＳ８に移行し、目標加速度Ｘｇｓを算出する。つまり、ステップＳ７で算出した目標車速Ｖｓ及び前記ステップＳ２で算出した自車両の走行速度Ｖとの差分値から、例えばＰＩＤ（比例−積分−微分）制御により算出する。なお、目標加速度Ｘｇｓは、正値を加速とする。
【００４６】
次いで、ステップＳ９に移行し、設定車速Ｖｃと車線維持継続可能速度ＶＬとの大小関係に基づいて目標加速度Ｘｇｓを補正し、目標加速度補正値Ｘｇｓｈを算出する。
つまり、設定車速Ｖｃが車線維持継続可能速度ＶＬよりも小さい（Ｖｃ＜ＶＬ）ときには、車線維持継続可能速度ＶＬまで加速されることはないから補正は行わず、目標加速度補正値Ｘｇｓｈとして目標加速度Ｘｇｓを設定する（Ｘｇｓｈ＝Ｘｇｓ）。
【００４７】
逆に、設定車速Ｖｃが車線維持継続可能速度ＶＬ以上（Ｖｃ≧ＶＬ）である場合には、このとき、先行車両が存在し、且つ先行車両が設定車速Ｖｃよりも遅いとき、つまり、Ｖｓ≠Ｖｃのときには、先行車両に追従して走行するから、目標加速度Ｘｇｓの補正は行わず、Ｘｇｓｈ＝Ｘｇｓとする。逆に、先行車両が存在しないとき或いは先行車両が設定車速Ｖｃよりも早い場合には、Ｖｓ＝Ｖｃとなり、車線維持継続可能速度ＶＬまで加速する場合があるから、目標加速度Ｘｇｓの補正を行う。具体的には、自車両が、車線維持継続可能速度ＶＬに対応した前方距離ＺＬに到達するときの走行速度を、車線維持継続可能速度ＶＬにし得る加速度Ｘｇ_ZLと、目標加速度Ｘｇｓとの何れか小さい方を、目標加速度補正値Ｘｇｓｈとする。
【００４８】
前記加速度Ｘｇ_ZLは、次式（４）に基づいて算出する。なお式中のＸｇ_OFF は、カーブが絞り込んでいく場合を考慮して、多少加速を抑えるためのオフセット量である。
Ｘｇ_ZL＝（ＶＬ² −Ｖ² ）／（２・ＺＬ）−Ｘｇ_OFF ……（４）
ついで、ステップＳ１０に移行し、ステップＳ９で算出した目標加速度補正値Ｘｇｓｈが負である場合、つまり減速を必要とする場合に、当該目標加速度補正値Ｘｇｓｈにブレーキ諸元係数を乗じた値と、ステップＳ１で読み込んだ制動流体圧Ｐｍにブレーキ諸元係数を乗じた値とのうち、何れか大きい方を目標制動流体圧Ｐｗｓ_j として設定する。なお、ブレーキ諸元係数とは、例えば各車輪のディスクロータ−パッド間の摩擦係数、ホイールシリンダ断面積、ディスクロータ有効径、タイヤ転がり動半径等によって決まる係数である。
【００４９】
次いで、ステップＳ１１に移行し、ステップＳ９で算出した目標加速度補正値Ｘｇｓｈが正である場合、つまり加速を必要とする場合に、当該目標加速度補正値Ｘｇｓｈに駆動系諸元変数を乗じた値と、前記ステップＳ１で読み込んだアクセル開度Ａｃｃに駆動系諸元変数を乗じた値とのうち、何れか大きい方を目標駆動トルクＴｅｓとして算出する。なお、駆動系諸元変数とは、例えば歯車慣性、減速比、伝達効率、エンジン特性等によって決まる変数である。
【００５０】
次に、ステップＳ１２に移行し、ステップＳ１０で算出した目標制動流体圧Ｐｗｓ_j やステップＳ１１で算出した目標駆動トルクＴｅｓを前記制動流体圧制御装置１３やエンジン制御装置１１、変速機制御装置１２に向けて出力する。また、ステップＳ５で算出した目標操舵トルクＴref を操舵制御装置１４に出力すると共に、設定車速Ｖｃをディスプレイ２３に表示してからメインプログラムに復帰する。
【００５１】
次に、上記第１の実施の形態の動作を説明する。
図４は、その動作状況の一例を示したタイミングチャートであって、実線は各地点における車線維持継続可能車速推定値ＶＬ（ｚ）、破線は設定車速Ｖｃ、一点鎖線は自車両の走行速度Ｖ、を表したものである。また、図５は、図４の時点ｔ₂ における、車両前方の曲率データβｚを表したものであって、横軸は前方距離Ｚ、縦軸は曲率βｚである。
【００５２】
自動走行制御装置１０では、自動走行制御が指示されると、各種センサからのデータまた、画像処理装置１５からの車両前方の曲率βｚ、車線中心からの横変位、自車両のヨー角等を読み込み（ステップＳ１）、これらに基づいて走行速度Ｖ及び先行車両との相対速度ｄＬｘを算出し（ステップＳ２、Ｓ３）、さらに、自車両の走行速度Ｖに応じて目標車間距離Ｌｃを算出する（ステップＳ４）。
【００５３】
そして、自車両の走行車線に対するヨー角Φと、横変位量Ｘと、前方走行車線の運転者の注視点の曲率βｚ₀ に応じて、必要な操舵トルクを算出し、この操舵トルクと、このときの左右加速度Ｙｇの大きさに応じて設定される操舵トルク制限値Ｔlim との何れか小さい方を目標操舵トルクＴref として設定する（ステップＳ５）。
【００５４】
続いて、車両前方の各地点における曲率βｚに基づく各地点の車線維持継続可能速度推定値ＶＬ（ｚ）から車線維持継続可能速度ＶＬを算出する。このとき、例えば車両が直進路を走行している場合には、車両前方の曲率βｚは比較的小さく、車線維持継続可能速度推定値ＶＬ（ｚ）は比較的大きな値になる。逆に、カーブを走行している場合には、車両前方の曲率βｚはカーブの度合いに応じて変化し、これに基づいて算出される車線維持継続可能速度推定値ＶＬ（ｚ）も変化する（ステップＳ６）。
【００５５】
そして、車間距離Ｌｘ、目標車間距離Ｌｃ、先行車両との相対速度ｄＬｘ、に基づいて算出される、目標車間距離Ｌｃを確保するための走行速度と、設定車速Ｖｃとの何れか小さい方を目標車速Ｖｓとして設定し、これに基づいて目標加速度Ｘｇｓを算出する（ステップＳ７、Ｓ８）。
そして、設定車速Ｖｃが車線維持継続可能速度ＶＬよりも小さいとき、或いは設定車速Ｖｃが車線維持継続可能速度ＶＬ以上であり且つ先行車両が存在しその車速が設定車速Ｖｃよりも遅いときには、目標車速Ｖｓに基づく目標加速度Ｘｇｓを目標加速度補正値Ｘｇｓｈとし、先行車両が存在しないとき、或いは先行車両の車速が設定車速Ｖｃよりも大きい場合には、車線維持継続可能速度ＶＬとこれに対応した前方距離ＺＬをもとに、前方距離ＺＬ位置における速度が車線維持継続可能速度ＶＬとなり得るための加速度Ｘｇ_ZLを算出し、これと目標加速度Ｘｇｓの何れか小さい方を、目標加速度補正値Ｘｇｓｈとする（ステップＳ９）。つまり、目標加速度Ｘｇｓを、加速度Ｘｇ_ZLに制限する。
【００５６】
そして、この目標加速度補正値Ｘｇｓｈを得るべく、目標制動流体圧Ｐｗｓ_j や目標駆動トルクＴｅｓを算出し、これに応じた制御信号を制動流体圧制御装置１３やエンジン制御装置１１、変速機制御装置１２に出力する（ステップＳ１０〜Ｓ１２）。さらに、目標操舵トルクＴref を発生すべく、操舵制御装置１４に対して制御信号を送信する。
【００５７】
これによって、車両を、走行車線に沿って走行させるための、目標操舵トルクＴref がステアリングシャフト６に付加されるから、運転手は比較的少ない操舵トルクを付加するだけで、走行車線を維持して走行することができる。
また、先行車両との車間距離が所定の目標車間距離Ｌｃを保って走行するように、また、先行車両が存在しないときには設定車速Ｖｃで走行するように、走行速度が制御されるから、先行車両と目標車間距離Ｌｃを保ち、また設定車速Ｖｃで走行することになる。
【００５８】
ここで、車両が先行車両に追従して直進路を走行している場合には、曲率βｚが比較的小さいから、車線維持継続可能速度ＶＬは比較的大きな値となり、このとき、設定車速Ｖｃ或いは先行車両との車間距離に基づいて算出された目標加速度Ｘｇｓが、前記車線維持継続可能速度ＶＬに基づいて算出される加速度Ｘｇ_ZLよりも小さい場合には、設定車速Ｖｃ、又は、車間距離を目標車間距離Ｌｃに維持し得る加速度である目標加速度Ｘｇｓに基づいて、車間距離制御が行われることになる。
【００５９】
この状態から、図４に実線で示すように、時点ｔ₄ で車線維持継続可能車速推定値ＶＬ（ｚ）が最小となるカーブ、つまり、時点ｔ₄ でカーブの曲率がピークとなるカーブに進入してくると、車両前方の５地点Ｚ１〜Ｚ５における車線維持継続可能速度推定値ＶＬ（ｚ）は各地点における曲率βｚに応じて異なる値となり、各地点における車線維持継続可能速度推定値ＶＬ（ｚ）のうち、最も値の小さいものが、車線維持継続可能速度ＶＬとして設定され、また、この車線維持継続可能速度ＶＬとなった前方地点ＺＬにおける走行速度が、車線維持継続可能速度ＶＬとなり得るための加速度Ｘｇ_ZLが算出される。
【００６０】
このとき、比較的カーブの曲率が小さく車線維持継続可能速度ＶＬが大きい場合には、加速度Ｘｇ_ZLは、目標車間距離Ｌｃを維持するため或いは設定車速Ｖｃを満足し得る目標加速度Ｘｇｓよりも大きくなるから、目標加速度補正値Ｘｇｓｈとして目標加速度Ｘｇｓが選択される。
したがって、目標車間距離Ｌｃを維持するための走行速度或いは設定車速Ｖｃとなるように速度制御が行われて車間距離制御が行われる。
【００６１】
そして、車両が進行するにつれて、カーブの曲率が大きくなると、これに伴って車線維持継続可能速度推定値ＶＬ（ｚ）は減少するが、車線維持継続可能速度ＶＬが設定車速Ｖｃよりも大きい間は、目標加速度Ｘｇｓが目標加速度補正値Ｘｇｓｈとして設定され、目標加速度Ｘｇｓの補正は行われないから、先行車両が定速で走行している場合には、自車両も定速走行を行う。
【００６２】
そして、時点ｔ₁ で車線維持継続可能速度推定値ＶＬ（ｚ）が設定車速Ｖｃを下回るとこの車線維持継続可能速度推定値ＶＬ（ｚ）に基づいて設定される車線維持継続可能速度ＶＬが設定車速Ｖｃを下回るが、先行車両が設定車速Ｖｃよりも低い速度で走行している間は、目標加速度Ｘｇｓの補正は行われない。したがって自車両は引き続き定速度で走行する。
【００６３】
そして、車線維持継続可能速度ＶＬが設定車速Ｖｃを下回った状態で、先行車両に追従して定速度で走行している状態から、時点ｔ₂ で先行車両が車線変更を行う等によって先行車両が存在しなくなると、目標車速Ｖｓとして設定車速Ｖｃが設定される。このとき、先行車両が存在しないから、時点ｔ₂ で設定される、車線維持継続可能速度ＶＬに相当する前方地点ＺＬにおける速度が車線維持継続可能速度ＶＬとなり得る加速度Ｘｇｓ_ZLが、設定車速Ｖｃに基づく目標加速度Ｘｇｓよりも大きい場合には、目標加速度Ｘｇｓの補正は行われない。図４の場合、時点ｔ₂ における車両前方位置における曲率βｚは、図５に示すように前方距離Ｚ４の地点で曲率βｚが最大となるから、この地点における車線維持継続可能速度推定値ＶＬ（ｚ）が車線維持継続可能速度ＶＬとして設定される。
【００６４】
そして、この車線維持継続可能速度ＶＬに相当する車両前方位置Ｚ４における車両速度Ｖが、車線維持継続可能速度ＶＬとなり得るための加速度Ｘｇ_ZLが算出され、この加速度Ｘｇ_ZLと、目標加速度Ｘｇｓとの何れか小さい方が、目標加速度補正値Ｘｇｓｈとして設定されるが、比較的曲率が小さく加速度Ｘｇ_ZLが目標加速度Ｘｇｓよりも大きい間は、目標加速度Ｘｇｓが目標加速度補正値Ｘｇｓｈとして設定され、走行速度Ｖが設定車速Ｖｃとなるように目標加速度Ｘｇｓで加速が行われるから、走行速度Ｖは目標加速度Ｘｇｓの傾きで増加することになる。
【００６５】
そして、車両が進行し、時点ｔ₃ で、加速度Ｘｇ_ZLが目標加速度Ｘｇｓを下回ると、加速度Ｘｇ_ZLが目標加速度補正値Ｘｇｓｈとして設定され、この加速度Ｘｇ_ZLを満足するように制御が行われる。したがって、走行速度Ｖは緩やかに増加する。
そして、加速度Ｘｇ_ZLが目標加速度Ｘｇｓを下回る間、加速度Ｘｇ_ZLが目標加速度補正値Ｘｇｓｈとして設定され、これによって、走行速度Ｖは緩やかに増加し、時点ｔ₅ で加速度Ｘｇ_ZLが目標加速度Ｘｇｓを上回ると、目標加速度Ｘｇｓが目標加速度補正値Ｘｇｓｈとして設定され、以後、走行速度Ｖは目標加速度Ｘｇｓの傾きで増加することになる。
【００６６】
ここで、車線維持制御処理においては、車両前方の注視点におけるカーブの曲率βｚ₀ に基づいて、目標操舵トルクＴref を算出しており、カーブの曲率βｚがピークとなる時点ｔ₃ から時点ｔ₅ 付近では、目標操舵トルクＴref が大きくなる。このとき、時点ｔ₂ で先行車両が存在しなくなったことから、自車両は加速を始めるが、走行速度Ｖが加速されることによって左右加速度Ｙｇが増加すると、この目標操舵トルクＴref を発生させるだけでは、車線を維持することができなくなる場合がある。
【００６７】
しかしながら、時点ｔ₃ から時点ｔ₅ の間は、目標加速度Ｘｇｓが加速度Ｘｇ_ZLに制限され、走行速度Ｖは緩やかに増加する。このとき、加速度Ｘｇ_ZLは、車両前方の曲率に基づき、車線維持継続可能速度ＶＬに対応する車両前方位置ＺＬに車両が到達したときに、この時点における走行速度Ｖが車線維持継続可能速度ＶＬとなり得る加速度に設定しているから、車両前方位置ＺＬを通過する際に、車線を維持することの可能な速度に制限されることになる。したがって、車間距離制御による自車両の加速に伴って自車両が車線を逸脱することが回避され、車間距離制御による制御に起因して、車線維持制御が解除されることが回避される。
【００６８】
また、このとき、車両前方のカーブについて複数地点における曲率を検出し、これに基づく車線維持継続可能速度推定値ＶＬ（ｚ）が最小となるもの、つまり、検出した複数の曲率のうち曲率が最大となるものを逐次選択し、これに基づいて加速制御を行うようにしているから、自車両がカーブのピークを通過した時点からの加速度を、速やかに復帰させることができ、走行速度Ｖを速やかに設定車速Ｖｃに制御することができる。
【００６９】
また、上記第１の実施の形態においては、設定車速Ｖｃが車線維持可能速度推定値ＶＬよりも大きく、且つ先行車両が存在しないか又は先行車両が設定車速Ｖｃよりも早く、さらに、走行速度Ｖが設定車速Ｖｃとなるように加速制御が行われるときにのみ、目標加速度Ｘｇｓを制限するようにしている。したがって、追従走行中に先行車両が存在しなくなったとき、或いは追従走行中に先行車両が加速した場合等、先行車両が加速或いは存在しなくなったときにのみ、車線維持制御を維持し、例えば先行車両が存在し且つ先行車両が設定車速Ｖｃよりも低速度で走行している場合には、目標加速度Ｘｇｓの制限は行わない。よって、条件を満足するときにのみ目標加速度Ｘｇｓの制限を行うようにしているから、運転者が、車線維持制御を行うことによって自動運転を行うことができるという錯覚を持つことを回避することができる。
【００７０】
また、上記第１の実施の形態においては、目標加速度Ｘｇｓを制限するようにしているが、設定車速Ｖｃと車線維持継続可能速度ＶＬとの大小関係に基づいて目標車速Ｖｓを補正し、これに基づいて目標加速度Ｘｇｓを算出し、この目標加速度Ｘｇｓを得るべく、目標制動流体圧Ｐｗｓ_j や目標駆動トルクＴｅｓを算出し、制動流体圧制御装置１３やエンジン制御装置１１、変速機制御装置１２を制御するようにしてもよく、この場合も上記と同等の作用効果を得ることができる。
【００７１】
ここで、図２のステップＳ４、Ｓ７、Ｓ８、Ｓ１０〜Ｓ１２の処理が車間距離制御手段に対応し、操舵制御装置１４の処理が自動操舵手段に対応し、ステップＳ５及びＳ１２の処理が車線維持制御手段に対応し、単眼カメラ１５ａ及び画像処理装置１５が車両前方検知手段及び道路環境検知手段に対応し、図２のステップＳ６の処理が車線維持可能速度推定手段に対応し、ステップＳ９の処理が車間距離制御制限手段に対応している。
【００７２】
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、図６に示すように、ナビゲーションシステム２５（道路情報処理手段）を追加したものである。このナビゲーションシステム２５は、例えば自車両の現在位置をＧＰＳによって検出し、予め記憶保持している地図情報に基づいて、自車両周辺の道路環境情報を検出し、これを自動走行制御装置１０に出力している。前記道路情報としては、例えば、自車両の位置Ｘｎ（ｎは演算タイミングを示す）、自車両周辺の道路の曲率α、道路勾配θ、カントφを出力する。
【００７３】
そして、この第２の実施の形態においては、自動走行制御装置１０は、図７のフローチャートに基づいて、自動走行制御の演算処理を行う。なお、上記第１の実施の形態と同一部分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２の実施の形態における自動走行制御の演算処理においては、上記第１の実施の形態における自動走行制御の演算処理において、ステップＳ６ａでカーブの継続判断を行う処理が追加されている。
【００７４】
つまり、この第２の実施の形態においては、ステップＳ１ａで、各種データを読み込む際に、上記第１の実施の形態と同様に各種データを読み込むと共に、ナビゲーションシステム２５から、道路環境情報として、自車両の現在位置Ｘ（ｎ）、現在位置Ｘ（ｎ）を基準とした前方方向の各地点における道路の曲率αｓ、道路勾配θｓ、カントφｓを読み込む。そして、これを図示しない記憶領域に格納する。
【００７５】
なお、前記ｓは、データ番号であって、ナビゲーションシステム２５で保持する道路地図データのデータポイント間隔に依存している。
そして、上記第１の実施の形態と同様にして、ステップＳ２〜ステップＳ６の処理を実行し、ステップＳ６で車線維持継続可能速度ＶＬを算出した後、ステップＳ６ａに移行し、ナビゲーションシステム２５からの道路環境情報に基づいてカーブの継続判断処理を行う。
【００７６】
すなわち、まず、記憶領域に格納した道路環境情報に基づき、自車両の現在位置Ｘｎを基準とした自車両前方の移動量Ｘｍｚ位置における道路の曲率αｚ、道路勾配θｚ、カントφｚを検出する。なお、これらは、次式（５）に示すように、自車両の現在位置Ｘｎを基準とする移動量Ｘｍｚの関数で表すことができる。
αｚ＝ｐ（Ｘｍｚ）
θｚ＝ｈ（Ｘｍｚ）
φｚ＝ｇ（Ｘｍｚ） ……（５）
なお、前記移動量Ｘｍｚは、地図上のデータポイント間の距離Ｌｍｋをｋ＝１からｋ＝ｚまで加算した総和によって算出することができる。
【００７７】
そして、前記ステップＳ６の処理で算出した車線維持継続可能速度ＶＬに対し、今後さらに車線維持継続可能速度ＶＬが小さくなるか否かを判断する。つまり、前述の自車両前方の移動量Ｘｍｚ位置における道路の曲率αｚ、道路勾配θｚ、カントφｚを順次検索し、ステップＳ６で用いた、車線維持継続可能速度ＶＬに対応する前方位置ＺＬ位置に対し、移動量ＸｍｚがＺＬ位置よりも大きく、且つ同一カーブの終了位置、つまり、曲率αｚがカーブが終了したとみなすことの可能な曲率のしきい値を超えるまでの間に、その曲率αｚが前記前方位置ＺＬにおける曲率βｚよりも大きくなる地点があるかどうかを判定する。そして、曲率αｚが曲率βｚよりも大きくなる地点がある場合には、カーブが継続すると判定し、カーブ継続フラグＦｃｒをＦｃｒ＝ＯＮに設定し、該当する地点がない場合には、カーブは継続しないと判定し、カーブ継続フラグをＦｃｒ＝ＯＦＦに設定する。
【００７８】
そして、前記第１の実施の形態と同様にステップＳ７及びＳ８を実行して、目標車速Ｖｓ及び目標加速度Ｘｇｓを算出し、次いで、ステップＳ９ａに移行する。
このステップＳ９ａでは、上記第１の実施の形態と同様にして、目標加速度Ｘｇｓを補正し、目標加速度補正値Ｘｇｓｈを算出するが、このとき、カーブが継続するか否かに応じて、前記加速度Ｘｇ_ZLを算出するための（４）式におけるオフセット量Ｘｇ_OFF を変更している。
【００７９】
つまり、カーブ継続フラグがＦｃｒ＝ＯＮであるときには、Ｘｇ_OFF ＝Ｘｇ_OFF0×２とする。一方、Ｆｃｒ＝ＯＦＦであるときには、Ｘｇ_OFF ＝Ｘｇ_OFF0とする。なお、Ｘｇ_OFF0は基準オフセット量であり定数である。
そして、このようにして設定した、オフセット量Ｘｇ_OFF に基づいて前記（４）式にしたがって加速度Ｘｇ_ZLを算出する。
【００８０】
そして、上記第１の実施の形態と同様にして、設定車速Ｖｃと車線維持継続可能速度ＶＬとの大小関係、及び設定車速Ｖｃと先行車両の車速との大小関係に応じて、目標加速度補正値Ｘｇｓｈを設定する。
そして、ステップＳ１０に移行し、以後、上記第１の実施の形態と同様にして目標制動流体圧Ｐｗｓ_j や目標駆動トルクＴｅｓを算出し、これに応じた制御信号を制動流体圧制御装置１３やエンジン制御装置１１、変速機制御装置１２に出力する（ステップＳ１０〜Ｓ１２）。さらに、目標操舵トルクＴref を発生すべく、操舵制御装置１４に対して制御信号を送信する。
【００８１】
このように、第２の実施の形態においては、ナビゲーションシステム２５の道路環境情報を用いることで、カーブが今後どのように変化するかを認識することができる。
したがって、カーブが継続する場合には、オフセット量をＸｇ_OFF ＝Ｘｇ_OFF0×２としてより大きな値に設定し、これによって加速度Ｘｇ_ZLをより小さく設定し、目標加速度補正値Ｘｇｓｈをより小さく抑制することによって、カーブの継続状態を考慮してより早い時点で加速を抑制することができる。ここで、上述のように、単眼カメラ１５ａ等を用いて画像処理装置１５で走行車線の曲率βを算出するようにした自律的な前方検知においては、カーブが絞られているような場合には、旋回途中で先行車両がいなくなった場合、場合によっては、走行速度Ｖが車線維持継続可能速度ＶＬに達してしまい、全く加速しない状態となり、乗員に多少の違和感を与える状態となることも考えられる。
【００８２】
しかしながら、上記第２の実施の形態においては、カーブの継続状態に応じてより早い時点で加速を抑制するようにしているから、自然で連続的な加速を行うことができ、乗員に違和感を与えることを回避することができる。
また、この第２の実施の形態においても、設定車速Ｖｃが車線維持可能速度推定値ＶＬよりも大きく、且つ先行車両が存在しないか又は先行車両が設定車速Ｖｃよりも早く、さらに、走行速度Ｖが設定車速Ｖｃとなるように加速制御が行われるときにのみ、目標加速度Ｘｇｓを制限するようにしているから、運転者が、車線維持制御を行うことによって自動運転を行うことができるという錯覚を持つことを回避することができる。
【００８３】
なお、上記第２の実施の形態においては、ナビゲーションシステム２５からの道路環境情報を、カーブの継続判断にのみ用いた場合について説明したが、ステップＳ６の車線維持継続可能速度ＶＬの算出の際に、画像処理装置１５からの走行車線の曲率βに替えて、多少精度が落ちるが、ナビゲーションシステム２５からの曲率αｓを用いるようにしてもよい。
【００８４】
このようにナビゲーションシステム２５からの曲率αｓを用いて車線維持継続可能速度ＶＬを算出することによって、画像処理装置１５からの曲率βを用いる場合に比較して、より広範囲における曲率αｓを得ることができるから、より的確に加速度を抑制することができる。
次に、本発明の第３の実施の形態を説明する。
【００８５】
この第３の実施の形態は、上記第２の実施の形態において、自動走行制御の演算処理の処理手順が異なること以外は同様である。すなわち、この第３の実施の形態においては、図８に示すフローチャートにしたがって処理を行う。なお、上記第２の実施の形態と同一部には、同一符号を付与し、その詳細な説明は省略する。
【００８６】
この第３の実施の形態においては、上記第２の実施の形態と同様に、まず、ステップＳ１ａで各種データを読み込み、これに基づいて走行速度Ｖ、相対速度ｄＬｘ及び目標車間距離Ｌｃを算出する（ステップＳ２〜Ｓ４）。
次いで、ステップＳ４ａに移行し、カーブの継続判断処理を行う。この第３の実施の形態におけるカーブの継続判断処理は次のように行う。まず、車両前方の曲率αｓにしたがって、次式（６）に基づいて、各データポイント位置において今後必要となる必要操舵トルクＴｗｓを推定する（必要操舵トルク検出手段）。予め設定した数のデータポイント位置について必要操舵トルクＴｗｓを推定することによって、車両前方のカーブの一部分における必要操舵トルクＴｗｓが推定される。
【００８７】
Ｔｗｓ＝ｑ（Ｙgrs ）
Ｙgrs ＝Ｖrs² ・αｓ
Ｖrs＝（Ｖ² ＋２・ａ・Ｘｍｓ）^1/2 ……（６）
ここで、Ｖは現在の走行速度、ａは車間距離制御において算出される加速度、Ｘｍｓは、カーブの曲率がαｓとなる位置までの現在位置からの車両前方距離、Ｖrsは車両が車両前方距離Ｘｍｓに到達した時点における推定車速、Ｙgrs は車両が車両前方距離Ｘｍｓに到達した時点における左右加速度推定値である。また、関数ｑ（Ｙgrs ）は、例えば図９に示す特性を持っており、左右加速度推定値Ｙgrs の絶対値が増加するほど、必要操舵トルクＴｗｓが放物線状に増加するようになっている。そして、この特性はマップデータ化されており、算出された左右加速度推定値Ｙgrs から一意に必要操舵トルクＴｗｓが推定されるようになっている。
【００８８】
なお、車間距離制御における加速度ａは、厳密にいえば、前述の目標加速度Ｘｇｓであって、設定車速Ｖｃ等によって異なるが、ここでは、簡単のために固定値ａを用いている。
次に、図１０に示すように、必要操舵トルクＴｗｓが操舵トルク制限値Ｔlim の最大値Ｔlim _MAX を上回る、上回り時間ｔ_OVERを算出する。つまり、まず、Ｔｗｓ＞Ｔlim _MAX であり且つ車両が車両前方距離Ｘｍｓに到達した時点における推定車速ＶrsをＶrs₀ とし、その後、Ｔｗｓ≦Ｔlim _MAX となる時のＶrsをＶrs₁ とする。このようにして設定したＶrs₀ 及びＶrs₁ をもとに、次式（７）から上回り時間ｔ_OVERを算出する。
【００８９】
ｔ_OVER＝（Ｖrs₁ −Ｖrs₀ ）／ａ ……（７）
次に、上回り時間ｔ_OVERが、予め設定した規定値ｔ_OVERＬよりも大きいか否かに基づいてカーブ継続判断を行う。つまり、ｔ_OVER＞ｔ_OVERＬであるとき、カーブが継続していると判断し、カーブ継続フラグＦｃｒをＦｃｒ＝ＯＮとする。逆に、ｔ_OVER≦ｔ_OVERＬのときには、カーブが継続していないと判断し、カーブ継続フラグＦｃｒをＦｃｒ＝ＯＦＦとする。
【００９０】
次いで、ステップＳ４ｂに移行し、操舵トルク制限値Ｔlim の最大値Ｔlim _MAX の変更を行う（操舵トルク制限値変更手段）。つまり、ステップＳ４ａの処理で、カーブが継続しないと判断される場合には、短時間のみ操舵トルク制限値Ｔlim を大きくすることで、車線維持制御を継続することができるので、操舵トルク制限値Ｔlim の最大値Ｔlim _MAX を変更する。逆に、カーブが継続すると判断される場合には、どんなカーブでも通過できるという錯覚を運転者に与える場合があるので、最大値Ｔlim _MAX の変更は行わない。
【００９１】
前記最大値Ｔlim _MAX の変更は、ステップＳ４ａの処理で算出した車両前方のカーブの一部における必要操舵トルクＴｗｓのうちの最大値と、操舵トルク制限値Ｔlim を一時的に増加させる場合の上限値Ｔlim _H とに基づいて行い、これらのうちの何れか小さい方を、補正最大値Ｔlim _MAX ′として設定する。補正最大値Ｔlim _MAX ′に上限値Ｔlim _H を設け、必要操舵トルクＴｗｓを制限することにより、必要操舵トルクＴｗｓが無制限に増加することによって、運転者に違和感を与えることを回避することができる。
【００９２】
次いで、ステップＳ４ｃに移行し、目標操舵トルクＴref を算出する。例えば、自車両の走行車線に対するヨー角Φと、横変位量Ｘと、前方走行車線の注視点の曲率βｚ₀ 、勾配θｚ₀ 、カントφｚ₀ のそれぞれに走行速度Ｖに応じて変化する制御ゲインＫａ、Ｋｂ、Ｋｃ、Ｋｄ、Ｋｅを乗算した値の和（＝Ｋａ・Φ＋Ｋｂ・Ｘ＋Ｋｃ・βｚ₀ ＋Ｋｄ・θｚ₀ ＋Ｋｅ・φｚ₀ ）と、操舵トルク制限値Ｔlim とのうちの、何れか小さい方を目標操舵トルクＴref として設定する。
【００９３】
このように、ナビゲーションシステム２５から得た、車両前方の道路勾配θｓ、カントφｓをも用いることで、車線維持制御による車線維持性能をより向上させることができる。
なお、前記操舵トルク制限値Ｔlim は、ステップＳ４ｂの処理で操舵トルク制限値Ｔlim の最大値Ｔlim _MAX を変更した後の、例えば図１１に示すような、特性図にしたがって、左右加速度｜Ｙｇ｜に応じて設定される。
【００９４】
この特性図は、例えば図１１に示すように、前述の図３に示す、操舵トルク制限値Ｔlim の特性図において、左右加速度Ｙｇが旋回方向と同一方向に発生している場合の特性が異なっており、左右加速度ＹｇがＹｇ( Ｔ_MAX ) を超えた場合でも操舵トルク制限値Ｔlim は引き続き同じ傾きで増加し、操舵トルク制限値Ｔlim が補正最大値Ｔlim _MAX ′に達したときに、放物線状に減少するように設定される。
【００９５】
そして、このようにして目標操舵トルクＴref を設定すると、ステップＳ７に移行し、以後、上記第２の実施の形態と同様に処理を行い、目標車間距離Ｌｃを確保し得る目標車速Ｖｓを算出し（ステップＳ７）、目標加速度Ｘｇｓを算出する（ステップＳ８）。そして、目標加速度Ｘｇｓの補正は行わずにステップＳ１０ａに移行し、前記ステップＳ８で算出した目標加速度Ｘｇｓを目標加速度補正値Ｘｇｓｈとみなし、これに基づいて目標制動流体圧Ｐｗｓ_j を設定し（ステップＳ１０）、目標駆動トルクＴｅｓを算出し（ステップＳ１１）、ステップＳ１０で算出した目標制動流体圧Ｐｗｓ_j やステップＳ１１で算出した目標駆動トルクＴｅｓを前記制動流体圧制御装置１３やエンジン制御装置１１、変速機制御装置１２に向けて出力する。また、ステップＳ４ｃで算出した目標操舵トルクＴref を操舵制御装置１４に出力すると共に、設定車速Ｖｃをディスプレイ２３に表示してからメインプログラムに復帰する（ステップＳ１２）。
【００９６】
したがって、この第３の実施の形態においては、車両前方道路の曲率αｓ及び車間距離制御における加速度ａに基づいて今後必要とする必要操舵トルクＴｗｓを推定し、この必要操舵トルクＴｗｓが操舵トルク制限値Ｔlim の最大値Ｔlim _MAX を上回る時間から、カーブの継続判断を行っている。そして、カーブが継続しないと判断されるとき、つまり、カーブではないとき或いはカーブではあるが、短時間のみカーブが継続するときには、操舵トルク制限値Ｔlim が、補正最大値Ｔlim _MAX ′を超えない範囲で、一時的に操舵トルク制限値Ｔlim を大きくしている。
【００９７】
したがって、カーブを走行中に、先行車両が存在しなくなったために自車両が設定車速Ｖｃとなるように加速を開始した場合、操舵トルク制限値Ｔlim の大きさと車間距離制御による加速の度合いによっては、操舵トルク制限値Ｔlim の範囲内で、操舵トルクをステアリングシャフト６に付加しただけでは、車線維持を行うことができない場合がある。しかしながら、カーブが継続しないと判断されるときには一時的に操舵トルク制限値Ｔlim の最大値Ｔlim _MAX をより大きな値に変更しているから、通常よりも大きな操舵トルクをステアリングシャフト６に付加することができ、車線を逸脱することを回避することができる。したがって、車線維持制御を行いながら、カーブを通過することができ、また、このとき、必要操舵トルクＴｗｓの算出を、車間距離制御における加速度ａに基づいて行うようにしているから、車間距離制御においてカーブ走行中に加速した場合であっても車線維持制御を継続することができる。
【００９８】
なお、上記第３の実施の形態においては、操舵トルク制限値Ｔlim の最大値Ｔlim _MAX のみを大きな値に変更するようにしているが、上記第１又は第２の実施の形態と組み合わせ、操舵トルク制限値Ｔlim の最大値Ｔlim _MAX をより大きな値に変更すると共に、車間距離制御における走行速度や加速度を制限するようにしてもよい。このように操舵トルクだけでなく走行速度や加速度をも調整することによって、操舵トルク制限値Ｔlim を比較的小さな値に設定することができ、最終的な上限値上限値Ｔlim _H に達する可能性を小さくすることができる。
【００９９】
また、上記第２及び第３の実施の形態においては、ナビゲーションシステム２５を用いた場合について説明したが、これに限らず、例えば道路側に設置されたインフラストラクチャ設備と通信を行うための情報受信手段を自車両に設け、インフラストラクチャ設備と通信を行って、車両周辺環境情報を得るようにしてもよい。
【０１００】
また、上記各実施の形態においては、先行車両との車間距離に基づいて自車両速度を制御する部分に、フィードバック制御を用いた場合について説明したが、これに限るものではなく、例えば自動車技術会誌1999.11 月号（Ｐ９８〜Ｐ１０３、「車間自動制御システムの開発」、飯島他）にあるように、フィードバック制御とフィードフォワード制御とを組み合わせたものを適用するようにしてもよい。すなわち、本発明は目標車間距離を変更する制御に関するものであり、車間距離の制御については、各種の制御則を適用することができる。
【図面の簡単な説明】
【図１】本発明を適用した車両用総合制御装置を備えた車両の一例を示す車両構成図である。
【図２】図１の自動走行制御装置１０で行われる自動走行制御のための演算処理を示すフローチャートである。
【図３】左右加速度｜Ｙｇ｜と操舵トルク制限値Ｔlim との対応を示す特性図である。
【図４】第１の実施の形態の動作説明に供するタイミングチャートである。
【図５】第１の実施の形態の動作説明に供するタイミングチャートである。
【図６】第２の実施の形態における車両用総合制御装置を備えた車両の一例を示す車両構成図である。
【図７】第２の実施の形態における自動走行制御のための演算処理を示すフローチャートである。
【図８】第３の実施の形態における自動走行制御のための演算処理を示すフローチャートである。
【図９】必要操舵トルクＴｗｓを左右加速度推定値Ｙgri に基づいて算出するための関数ｑ（Ｙgri ）の特性を示す特性図である。
【図１０】上回り時間ｔ_OVERの説明に供する説明図である。
【図１１】第３の実施の形態における左右加速度｜Ｙｇ｜と操舵トルク制限値Ｔlim との対応を示す特性図である。
【符号の説明】
１ＦＬ〜１ＲＲ 車輪
２ エンジン
３ 自動変速機
４ＦＬ〜４ＲＲ ホイールシリンダ
５ ステアリングホイール
６ ステアリングシャフト
９ 手動スイッチ
１０ 自動走行制御装置
１１ エンジン制御装置
１２ 変速機制御装置
１３ 制動流体圧制御装置
１４ 操舵制御装置
１５ 画像処理装置
１５ａ 単眼カメラ
１６ 車間距離センサ
１７ 車輪速センサ
１８ 加速度センサ
１９ 制動流体圧センサ
２０ アクセル開度センサ
２１ ブレーキペダル
２２ マスタシリンダ
２３ ディスプレイ
２５ ナビゲーションシステム[0001]
BACKGROUND OF THE INVENTION
The present invention controls the traveling state of the host vehicle to control the inter-vehicle distance between the preceding vehicle and the host vehicle, and also controls the steering torque so that the host vehicle travels while maintaining the vicinity of the center of the traveling lane. The present invention relates to a vehicle overall control device that performs lane keeping control.
[0002]
[Prior art]
Conventionally, to control the steering actuator that generates the steering torque according to the lateral deviation amount of the traveling position of the vehicle from the reference position of the traveling lane so that the own vehicle travels while maintaining the vicinity of the center of the traveling lane, A lane keeping device or the like that reduces the load caused by the driver's lane keeping operation is known. In addition, when there is no preceding vehicle, the vehicle travels while keeping the vehicle speed at the set vehicle speed, and when there is a preceding vehicle, speed control is performed so as to follow the preceding vehicle so as to control the inter-vehicle distance. An inter-vehicle distance control device is known.
[0003]
Further, as described in Japanese Patent Application Laid-Open No. 11-42955, during a curve run, by limiting the acceleration according to the curvature of the curve and the own vehicle speed, it is possible to make a comfortable run on the curve. Some of these have been proposed.
In addition, vehicles including both a lane keeping control device and an inter-vehicle distance control device have been proposed.
[0004]
[Problems to be solved by the invention]
By the way, the lane keeping control device aims to significantly reduce the load on the driver who is going along the lane by adding steering torque to the steering shaft so that the vehicle can run while maintaining the vicinity of the center of the lane. It is said. However, if the steering torque to be applied is too large, it is possible not only to reduce the driver's load, but it is possible to drive on a curve or the like without any steering by the driver in most driving scenes. The driver may be given the illusion that the vehicle will automatically travel, and the driver may travel without the steering wheel.
[0005]
Therefore, the steering torque applied to the steering shaft by the lane keeping control device is limited to a set value or less so that the driver does not release the steering wheel.
By doing so, when the vehicle is in a turning state in which a large lateral acceleration is generated, if the driver releases the steering wheel, the steering torque is insufficient and the driver deviates from the lane. You can't let go of the steering wheel.
[0006]
On the other hand, the inter-vehicle distance control apparatus basically follows the preceding vehicle. For example, when the set vehicle speed is as large as about 100 km / h and the preceding vehicle is traveling at a speed lower than the set vehicle speed of about 80 km / h, the preceding vehicle changes lanes, etc. When there is no preceding vehicle, the vehicle is accelerated to the set vehicle speed even during a turn.
[0007]
If the curve is steep, there is a method to limit the acceleration according to the curvature, but the actual lateral acceleration is detected, the lateral acceleration is estimated from the steering angle and the vehicle speed, and the acceleration is limited based on this. The value is set, and is set according to the turning performance of the base vehicle itself.
When such two controls, namely, the inter-vehicle distance control and the lane keeping control operate simultaneously, and the preceding vehicle disappears during the turn, the inter-vehicle distance control device causes the own vehicle speed to become the set vehicle speed. In some cases, the lateral acceleration increases, and there is a problem that the lane cannot be maintained with the steering torque generated in the lane keeping control.
[0008]
In addition, when the lane keeping control device is operating alone, the driver deviating from the lane due to acceleration while turning is due to the driver's operation reaching the limit of the lane keeping control device. Because it is, it is necessary not to make it feel like driving automatically. However, both control devices are operating, and the driver accelerates the vehicle speed so that the vehicle speed becomes the set vehicle speed in the inter-vehicle distance control device, although the control of the vehicle speed is left to some extent to the inter-vehicle distance control. The fact that the lane cannot be maintained in the lane keeping control with this acceleration makes the driver feel uncomfortable.
[0009]
Accordingly, the present invention has been made paying attention to the above-described conventional unsolved problems, and is capable of performing lane keeping control and inter-vehicle distance control satisfactorily regardless of the driving situation. The purpose is to provide.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a comprehensive control apparatus for a vehicle according to claim 1 of the present invention controls the speed of the host vehicle so that the inter-vehicle distance between the host vehicle and the preceding vehicle coincides with the target inter-vehicle distance. The inter-vehicle distance control means, the automatic steering means capable of controlling the steering torque regardless of the driver's steering operation, and the automatic torque within the range of the steering torque limit value so that the host vehicle travels while maintaining the lane. Lane keeping control means for controlling the steering means, The limit value of the steering torque is set to a value that prevents the driver from releasing the steering wheel even when the steering torque is controlled by the lane keeping control means. In the vehicle overall control apparatus, a road lane within a range of the steering torque limit value based on road environment detection means for detecting a road condition in front of the vehicle and road conditions in front of the vehicle detected by the road environment detection means. A lane maintaining continuable speed estimating means for estimating a lane maintaining continuable speed that can be maintained, and the lane maintaining continuable speed when the inter-vehicle distance control means and the lane maintaining control means are operating together. And an inter-vehicle distance control limiting unit that limits the vehicle speed controlled by the inter-vehicle distance control unit.
[0011]
In the invention according to claim 1, for example, based on road conditions such as road curvature in front of the vehicle detected by road environment detection means such as vehicle forward detection means for detecting the position of the host vehicle in the traveling lane, The lane maintaining continuable speed capable of maintaining the lane within the range of the steering torque limit value is estimated. Then, the inter-vehicle distance control means for controlling the speed of the host vehicle so that the inter-vehicle distance from the preceding vehicle becomes the target inter-vehicle distance, and steering control is performed by applying a steering torque so that the host vehicle travels along the traveling lane. When the lane keeping control means to be operated is operating together, the speed of the host vehicle controlled by the inter-vehicle distance control means is limited according to the lane keeping continuation possible speed.
[0012]
Therefore, by limiting the speed of the host vehicle according to the lane maintenance continuable speed according to the road condition ahead of the vehicle, for example, there is no preceding vehicle that is following the curve and the host vehicle accelerates to the set vehicle speed. Even in such a case, since acceleration is performed within a range in which the lane can be maintained within the range of the steering torque limit value, the steering torque is insufficient and the lane is not deviated.
[0013]
In the vehicle overall control device according to claim 2, the inter-vehicle distance control limiting unit detects a continuation state of a curve ahead of the vehicle based on a road condition ahead of the vehicle detected by the road environment detection unit, The vehicle speed controlled by the inter-vehicle distance control means is limited in accordance with the continuation state of the curve and the lane maintaining continuable speed.
[0014]
In the invention according to claim 2, the continuation state of the curve ahead of the vehicle is detected based on the road condition ahead of the vehicle detected by the road environment detection means, and based on the continuation state of this curve and the lane maintenance continuation possible speed. The vehicle speed controlled by the inter-vehicle distance control means is limited. Therefore, for example, when the curve continues, by limiting the vehicle speed to a smaller value and changing the vehicle speed more slowly, it is possible to avoid the vehicle speed reaching the lane maintenance continuation speed in the middle of the curve and not accelerating. Thus, more natural speed control can be performed without causing the driver to feel uncomfortable.
[0015]
According to a third aspect of the present invention, there is provided the vehicle overall control device, wherein the road environment detection means is provided in the lane maintenance control means and detects the vehicle position in the traveling lane, a vehicle forward detection means, At least one of road information processing means for detecting road information around the own vehicle based on map information stored in advance and detecting the current position or information receiving means for receiving information on the road surface condition ahead of the own vehicle from the information providing device It is characterized by being one side.
[0016]
According to a fourth aspect of the present invention, in the vehicle overall control apparatus, the lane maintaining continuable speed estimating means is configured to limit the road information ahead of the vehicle and the steering torque detected by the road information processing means or the information receiving means. Thus, the lane maintaining continuable speed is estimated.
The vehicle overall control apparatus according to claim 5 is characterized in that the inter-vehicle distance control limiting means limits the vehicle speed in the inter-vehicle distance control means by limiting acceleration.
[0017]
According to a sixth aspect of the present invention, the inter-vehicle distance control restricting means is configured such that the inter-vehicle distance control limiting means predicts that the lane maintaining continuable speed and the speed of the host vehicle reach the lane maintaining continuable speed. The acceleration is limited according to the distance to the vehicle and the current speed of the host vehicle.
According to a seventh aspect of the present invention, in the vehicle overall control device, the inter-vehicle distance control means controls the speed of the host vehicle to be equal to or lower than a set vehicle speed, and controls the speed so as to be the set vehicle speed when the preceding vehicle does not exist. The inter-vehicle distance control limiting unit limits the speed or acceleration of the host vehicle only when the inter-vehicle distance control unit performs acceleration control so that the speed of the host vehicle becomes the set vehicle speed. It is characterized by that.
[0018]
In the invention according to claim 7, the inter-vehicle distance control means controls the speed of the host vehicle to be equal to or lower than the set vehicle speed, and performs speed control to be the set vehicle speed when there is no preceding vehicle. At this time, in the inter-vehicle distance control limiting unit, when the acceleration control is performed by the inter-vehicle distance control unit so that the speed of the host vehicle becomes the set vehicle speed, that is, the following vehicle is no longer following and the vehicle is accelerated to the set vehicle speed. Or the speed or acceleration of the host vehicle is limited only when the preceding vehicle is accelerated so that the vehicle speed is higher than the set vehicle speed.
[0019]
Therefore, the vehicle is restricted only when the condition is satisfied, and the lane maintaining control means can maintain the lane, and when the condition is not satisfied, the lane maintaining control means cannot be maintained, so the driver is automatically It is possible to avoid giving the illusion that driving is possible.
The vehicle overall control device according to claim 8 detects the continuation state of the curve ahead of the vehicle based on the road condition ahead of the vehicle detected by the road environment detection means, and based on the continuation state of the curve. Necessary steering torque detection means for detecting the steering torque required when passing the curve, and the necessary steering torque detection means need to be detected when the inter-vehicle distance control means and the lane keeping control means are operating together. When the torque excess duration predicted to exceed the steering torque limit value is detected and the torque excess duration is within a preset allowable value, the steering torque limit value is set to a larger value. Steering torque limit value changing means for changing.
[0020]
In the invention according to claim 8, the continuation state of the curve ahead of the vehicle is detected based on the road condition ahead of the vehicle detected by the road environment detection means, and the vehicle passes through this curve based on the continuation state of this curve. Necessary steering torque that is necessary for this is detected. When both the inter-vehicle distance control means and the lane keeping control means are operating, a torque excess duration time that is predicted that the required steering torque exceeds the steering torque limit value is detected, and this torque excess duration time is detected. When the value is within the preset allowable value, the limit value of the steering torque is changed to a larger value. Therefore, when the torque excess duration is short, the steering torque limit value is temporarily changed to a larger value, so that the necessary steering torque necessary for passing the curve is applied when passing the curve. Become. Therefore, the own vehicle does not deviate from the lane, and at this time, the speed or acceleration of the own vehicle controlled by the inter-vehicle distance control means is also limited according to the lane maintaining continuable speed or the continuation state of the curve. The limit value of the steering torque can be set low.
[0021]
The vehicle overall control device according to claim 9 of the present invention includes an inter-vehicle distance control means for controlling the speed of the own vehicle so that the inter-vehicle distance between the own vehicle and the preceding vehicle coincides with the target inter-vehicle distance. An automatic steering means capable of controlling the steering torque regardless of the driver's steering operation, and a lane for controlling the automatic steering means within the range of the steering torque limit value so that the host vehicle travels while maintaining the lane. Maintenance control means, The limit value of the steering torque is set to a value that prevents the driver from releasing the steering wheel even when the steering torque is controlled by the lane keeping control means. In the vehicle overall control device, the road environment detection means for detecting the road situation in front of the vehicle, and the continuation state of the curve in front of the vehicle based on the road situation in front of the vehicle detected by the road environment detection means, When the necessary steering torque detecting means for detecting the steering torque required when passing the curve based on the continuation state of the curve, and the inter-vehicle distance control means and the lane keeping control means are operating, the required steering torque When the required steering torque detected by the detecting means detects a torque excess duration time that is predicted to exceed the steering torque limit value and the torque excess duration time is within a preset allowable value, Steering torque limit value changing means for changing the limit value to a larger value.
[0022]
In the invention according to claim 9, the continuation state of the curve ahead of the vehicle is detected based on the road condition ahead of the vehicle detected by the road environment detection means, and the vehicle passes through this curve based on the continuation state of this curve. Necessary steering torque that is necessary for this is detected. When both the inter-vehicle distance control means and the lane keeping control means are operating, a torque excess duration time that is predicted that the required steering torque exceeds the steering torque limit value is detected, and this torque excess duration time is detected. When the value is within the preset allowable value, the limit value of the steering torque is changed to a larger value. Therefore, when the torque excess duration is short, the steering torque limit value is temporarily changed to a larger value, so that the necessary steering torque necessary for passing the curve is applied when passing the curve. Therefore, the host vehicle does not deviate from the lane, and at this time, the limit value of the steering torque is temporarily changed, so the illusion that automatic driving is possible for the driver. Can be avoided.
[0023]
【The invention's effect】
According to the vehicle overall control device according to claims 1 to 8 of the present invention, the speed of the host vehicle is limited according to the lane maintaining continuable speed according to the road condition ahead of the vehicle. When both the control means and the lane keeping control means are operating, it is avoided that the steering torque in the lane keeping control means becomes insufficient due to acceleration accompanying the vehicle speed control by the inter-vehicle distance control means. Thus, the inter-vehicle distance control and the lane keeping control can be performed satisfactorily without causing the driver to feel uncomfortable.
[0024]
In particular, according to the vehicle overall control device of the second aspect, the continuation state of the curve ahead of the vehicle is detected based on the road condition ahead of the vehicle detected by the road environment detection means, and the continuation state and lane of this curve are detected. Since the vehicle speed controlled by the inter-vehicle distance control means is limited based on the sustainable speed, more natural speed control can be performed without giving the driver a sense of incongruity.
[0025]
According to the vehicle overall control device of claim 7, the speed or acceleration of the host vehicle is limited only when acceleration control is performed by the inter-vehicle distance control means so that the speed of the host vehicle becomes the set vehicle speed. Therefore, it is possible to avoid giving the driver the illusion that automatic driving is possible.
Further, according to the comprehensive control device for a vehicle according to claim 8 and claim 9, when the necessary steering torque is detected based on the continuation state of the curve ahead of the vehicle, the necessary steering torque exceeds a limit value of the steering torque. When the predicted torque excess duration is within a preset allowable value, the steering torque limit value is changed to a larger value, so that sufficient steering torque can be added and the lane is maintained. be able to.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, a first embodiment of the present invention will be described.
FIG. 1 is a system configuration diagram showing an embodiment of a vehicle provided with a vehicle overall control device to which the present invention is applied. This vehicle is a rear wheel drive vehicle in which the rear wheels 1RL and 1RR are driving wheels and the front wheels 1FL and 1FR are driven wheels, and the driving torque of the engine 2 is transmitted to the rear wheels 1RL and 1RR via the automatic transmission 3. Is done.
[0027]
The rotation state, torque, output, etc. of the engine 2 can be controlled by the engine control device 11. Specifically, the rotational state, torque, output, etc. of the engine 2 can be controlled by adjusting the throttle valve opening, the idle valve opening, the ignition timing, the fuel injection amount, the fuel injection timing, and the like.
The automatic transmission 3 can be controlled by a transmission control device 12. Specifically, by adjusting the working fluid pressure supplied to the clutch and brake in the automatic transmission 3, the selected gear ratio can be changed to obtain a desired reduction ratio.
[0028]
Each of the wheels 1FL to 1RR includes wheel cylinders 4FL to 4RR that constitute a so-called disc brake. The wheel cylinders 4FL to 4RR apply a braking force to the wheels 1FL to 1RR by the supplied brake fluid pressure. The braking force applied to each of the wheels 1FL to 1RR can be controlled by the braking fluid pressure control device 13. Specifically, for example, each wheel cylinder 4FL is increased by increasing the brake fluid pressure as in the driving force control device (TCS) or decreasing the brake fluid pressure as in the anti-skid control device (ABS). The braking fluid pressure to ~ 4RR can be adjusted, and the braking force to each wheel 1FL to 1RR can be controlled. The braking fluid pressure regulated in the braking fluid pressure control device 13 is supplied from a master cylinder 22 that is boosted by depressing the brake pedal 21.
[0029]
Further, the steering shaft 6 is provided with a known steering control device 14 incorporating a steering angle sensor for detecting the steering angle, so that a steering torque is applied to the steering shaft 6 separately from the steering operation of the steering wheel 5. It has become.
A monocular camera 15a for imaging the vehicle front situation is fixedly installed at an appropriate location such as an inner mirror stay in the vehicle interior, and image data captured by the monocular camera 15a is sent to the image processing device 15. The image processing device 15 performs binarization processing and the like to detect a lane marker in the vicinity of the host vehicle, and uses the yaw angle Φ of the host vehicle as a signal related to the position of the host vehicle in the traveling lane, The displacement amount X and the curvature β of the travel lane are calculated, and the results are output to the automatic travel control device 10.
[0030]
Each of these control devices controls the running state of the vehicle, and as a result, the running state can be controlled by adjusting the acceleration / deceleration, the longitudinal speed, etc. of the host vehicle.
These control devices can operate independently, but the overall function is governed by the automatic travel control device 10 including inter-vehicle distance control and lane keeping control. The automatic travel control device 10 performs various arithmetic processes to control the travel state of the vehicle, and performs inter-vehicle distance control, lane keeping control, and the like.
[0031]
In addition, the vehicle is provided with a laser radar and an inter-vehicle distance sensor 16 that detects an inter-vehicle distance to a preceding vehicle, a wheel speed sensor 17 that detects a rotational speed of each wheel 1FL to 1RR, and longitudinal and lateral accelerations generated in the vehicle. An acceleration sensor 18 for detecting, a brake fluid pressure sensor 19 for detecting the brake fluid pressure, and an accelerator opening sensor 20 for detecting the depression amount of the accelerator pedal are provided. Further, the vehicle is provided with a main switch 9 for adjusting the traveling state of the host vehicle by manual input by the driver. Further, the vehicle is provided with a display 23 for displaying the set vehicle speed Vc and the target inter-vehicle distance Lc in the inter-vehicle distance control set by the driver.
[0032]
Next, calculation processing of automatic traveling control that performs inter-vehicle distance control and lane keeping control performed in the automatic traveling control device 10 will be described with reference to the flowchart of FIG. In this calculation process, when both of the inter-vehicle distance control and the lane keeping control are selected by a manual switch (not shown) and instructed to perform both of these controls, for example, a predetermined sampling time ΔT set to about 10 [msec], for example. Each time it is executed by a timer interrupt.
[0033]
In this flowchart, no particular communication step is provided, but the results obtained by the arithmetic processing are updated and stored in the storage device as needed, and necessary information and programs are read from the storage device as needed. The engine control device 11, the transmission control device 12, the brake fluid pressure control device 13, the steering control device 14, and the image processing device 15 communicate with each other at any time, and necessary information and commands are exchanged in both directions at any time. The
[0034]
In this calculation process, first, the longitudinal acceleration Xg, the lateral acceleration Yg detected by the acceleration sensor 18 in step S1, and the wheel speed Vw detected by the wheel speed sensor 17 are detected. _j (J = FL to RR), accelerator opening Acc detected by the accelerator opening sensor 20, braking fluid pressure Pm detected by the brake fluid pressure sensor 19, and set speed Vc set by the manual switch 9 Then, the steering angle δ detected by the steering angle sensor incorporated in the steering control device 14 and the inter-vehicle distance Lx detected by the inter-vehicle distance sensor 16 are read. Further, the yaw angle Φ of the host vehicle, the lateral displacement X from the lane center, and the curvature β of the traveling lane, which are processed by the image processing device 15, are read.
[0035]
The curvature β can be expressed as a function f (Z) of the distance Z (βz = f (Z)), where βz is the curvature at the point of the distance Z ahead of the vehicle with respect to the current position. ).
Next, the process proceeds to step S2, where the wheel speed Vw read in step S1 is read. _j Among them, the front left and right wheel speeds Vw which are driven wheels _FL , Vw _FR The traveling speed V of the host vehicle is calculated from the average value. When ABS control or the like is being performed, the estimated vehicle speed estimated in the ABS control process may be used, and the traveling speed V can be simply calculated by rotating the output shaft of the automatic transmission 3. You may make it calculate from a number etc.
[0036]
Next, the process proceeds to step S3, and the current value Lx of the inter-vehicle distance from the preceding vehicle read in step S1. _(n) And the previous value Lx _(n-1) And the relative speed dLx between the host vehicle and the preceding vehicle is calculated.
Next, the process proceeds to step S4, and the target inter-vehicle distance Lc is calculated based on the following equation (1) according to the traveling speed V of the host vehicle calculated in step S2.
[0037]
Lc = Kv1 × V + Kv2 (1)
Note that Kv1 and Lv2 in the formula are control constants. In the first embodiment, the target inter-vehicle distance Lc is calculated based on the traveling speed V of the host vehicle. However, the driver may be able to set the inter-vehicle distance using a manual switch. . Specifically, for example, the driver can set the three stages of long, medium and short, and the control constant of the equation (1) may be changed accordingly to change the target inter-vehicle distance Lc. .
[0038]
Next, the process proceeds to step S5, and the target steering torque Tref is calculated. For example, the yaw angle Φ with respect to the traveling lane of the host vehicle, the lateral displacement amount X, and the curvature βz of the gazing point of the forward traveling lane ₀ The sum of the values obtained by multiplying the control gains Ka, Kb, and Kc that change according to the traveling speed V (= Ka · Φ + Kb · X + Kc · βz) ₀ ) And the steering torque limit value Tlim, whichever is smaller is set as the target steering torque Tref.
[0039]
Note that the lane keeping control in which the steering control device 14 applies steering assist torque to the steering shaft 6 so that the vehicle travels along the traveling lane is performed only when execution of the lane keeping control is instructed by a switch (not shown). If the vehicle deviates from the lane due to a strong crosswind during the lane keeping control, the lane keeping control is canceled. As described above, when it is determined that the control cannot be continued due to an external factor and the lane keeping control is cancelled, the display 23 indicates that the lane maintaining control is to be cancelled, or a voice or warning is issued. For example, the driver is notified.
[0040]
The steering torque limit value Tlim is a limit value for the steering torque applied to the steering shaft 6 by the lane keeping control process. Is set to a value that does not release For example, as shown in the characteristic diagram of FIG. 3, it is set according to the lateral acceleration Yg.
[0041]
As shown in FIG. 3, when the lateral acceleration Yg is generated in the same direction as the turning direction, this characteristic diagram increases in proportion to the increase in the lateral acceleration | Yg |, and the lateral acceleration | Yg | ｜ Yg (T _MAX ) Is reduced to a parabolic shape, and conversely, when the lateral acceleration Yg is generated in the direction opposite to the turning direction, it is set to decrease in proportion to the increase of the lateral acceleration | Yg |. .
[0042]
The lateral acceleration Yg used here may be the measured lateral acceleration Yg, or may be a value calculated based on the traveling speed V and the steering angle δ.
Next, the process proceeds to step S6, and the lane maintaining continuable speed VL is calculated. In this embodiment, the lane maintaining continuable speed VL is calculated based on the curve curvature βz in front of the vehicle.
[0043]
That is, the curve curvature βz (= f (z)) in front of the vehicle and the steering torque limit value Tlim are the maximum values Tlim. _MAX Left-right acceleration Yg (T _MAX Based on the following equation (2), a lane maintaining continuable speed estimated value VL (z) at the distance Z position in front of the vehicle is calculated.
VL (z) = [Yg (T _MAX ) / Βz] ^1/2 (2)
However, Z is a distance within a range that can be detected by the monocular camera 15a, and is, for example, five points Z1 to Z5 in front of the vehicle, for example, 20 [m], 30 [m], 40 [m], 50 [m]. , 60 [m] points are calculated.
[0044]
And among the lane maintenance continuable speed estimated value VL (z) calculated in this way at a plurality of points ahead of the vehicle, the minimum value is set as the lane maintenance continuable speed VL.
Next, the process proceeds to step S7, and the target vehicle speed Vs is calculated. Here, calculation is performed according to the following equation (3) based on the set vehicle speed Vc, the inter-vehicle distance Lx, the target inter-vehicle distance Lc, and the relative speed dLx with the preceding vehicle. Note that Klp and Kld in the equation are control gains. Min [a, b] represents a function that takes the smaller one of a and b.
[0045]

Next, the process proceeds to step S8, and the target acceleration Xgs is calculated. That is, it is calculated by, for example, PID (proportional-integral-derivative) control from the difference value between the target vehicle speed Vs calculated in step S7 and the traveling speed V of the host vehicle calculated in step S2. The target acceleration Xgs has a positive value as acceleration.
[0046]
Next, the process proceeds to step S9, where the target acceleration Xgs is corrected based on the magnitude relationship between the set vehicle speed Vc and the lane maintaining continuable speed VL, and a target acceleration correction value Xgsh is calculated.
In other words, when the set vehicle speed Vc is smaller than the lane maintaining continuable speed VL (Vc <VL), the vehicle is not accelerated to the lane maintaining continuable speed VL, so that the correction is not performed and the target acceleration Xgs is set as the target acceleration correction value Xgs. Is set (Xgsh = Xgs).
[0047]
On the contrary, when the set vehicle speed Vc is equal to or higher than the lane maintaining continuable speed VL (Vc ≧ VL), at this time, when the preceding vehicle exists and the preceding vehicle is slower than the set vehicle speed Vc, that is, Vs ≠ Since the vehicle travels following the preceding vehicle when Vc, the target acceleration Xgs is not corrected, and Xgsh = Xgs. Conversely, when there is no preceding vehicle or when the preceding vehicle is faster than the set vehicle speed Vc, Vs = Vc and the vehicle may accelerate to the lane maintaining continuable speed VL, so the target acceleration Xgs is corrected. Specifically, the acceleration Xg at which the traveling speed when the host vehicle reaches the forward distance ZL corresponding to the lane maintaining continuable speed VL can be set to the lane maintaining continuable speed VL. _ZL And the target acceleration Xgs, whichever is smaller, is set as a target acceleration correction value Xgsh.
[0048]
Acceleration Xg _ZL Is calculated based on the following equation (4). Xg in the formula _OFF Is an offset amount for suppressing acceleration to some extent in consideration of a case where the curve is narrowed down.
Xg _ZL = (VL ² -V ² ) / (2.ZL) -Xg _OFF ...... (4)
Next, the process proceeds to step S10, and when the target acceleration correction value Xgsh calculated in step S9 is negative, that is, when deceleration is required, a value obtained by multiplying the target acceleration correction value Xgsh by the brake specification coefficient, Of the values obtained by multiplying the brake fluid pressure Pm read in step S1 by the brake specification coefficient, whichever is greater is the target brake fluid pressure Pws. _j Set as. The brake specification coefficient is a coefficient determined by, for example, the friction coefficient between the disk rotor and the pad of each wheel, the wheel cylinder cross-sectional area, the disk rotor effective diameter, the tire rolling radius, and the like.
[0049]
Next, the process proceeds to step S11, and when the target acceleration correction value Xgsh calculated in step S9 is positive, that is, when acceleration is required, a value obtained by multiplying the target acceleration correction value Xgsh by a drive system specification variable The larger one of the values obtained by multiplying the accelerator opening Acc read in step S1 by the drive system variable is calculated as the target drive torque Tes. The drive system specification variable is a variable determined by, for example, gear inertia, reduction ratio, transmission efficiency, engine characteristics, and the like.
[0050]
Next, the process proceeds to step S12, and the target braking fluid pressure Pws calculated in step S10. _j The target drive torque Tes calculated in step S11 is output to the brake fluid pressure control device 13, the engine control device 11, and the transmission control device 12. In addition, the target steering torque Tref calculated in step S5 is output to the steering control device 14, and the set vehicle speed Vc is displayed on the display 23, and then the process returns to the main program.
[0051]
Next, the operation of the first embodiment will be described.
FIG. 4 is a timing chart showing an example of the operation state, where the solid line is the estimated lane-sustainable vehicle speed VL (z) at each point, the broken line is the set vehicle speed Vc, and the alternate long and short dash line is the traveling speed V of the host vehicle. . 5 shows the time t in FIG. ₂ , Representing the curvature data βz ahead of the vehicle, where the horizontal axis represents the forward distance Z and the vertical axis represents the curvature βz.
[0052]
When automatic traveling control is instructed, the automatic traveling control device 10 reads data from various sensors, the curvature βz in front of the vehicle from the image processing device 15, lateral displacement from the lane center, the yaw angle of the host vehicle, and the like. (Step S1) Based on these, the travel speed V and the relative speed dLx with the preceding vehicle are calculated (Steps S2 and S3), and the target inter-vehicle distance Lc is calculated according to the travel speed V of the host vehicle (Step S1). S4).
[0053]
Then, the yaw angle Φ with respect to the traveling lane of the host vehicle, the lateral displacement amount X, and the curvature βz of the driver's point of interest in the forward traveling lane ₀ Accordingly, the necessary steering torque is calculated, and the smaller one of the steering torque and the steering torque limit value Tlim set according to the magnitude of the lateral acceleration Yg at this time is set as the target steering torque Tref. (Step S5).
[0054]
Subsequently, the lane maintaining continuable speed VL is calculated from the estimated lane maintaining continuable speed VL (z) at each point based on the curvature βz at each point in front of the vehicle. At this time, for example, when the vehicle is traveling on a straight road, the curvature βz in front of the vehicle is relatively small, and the lane maintaining continuable speed estimated value VL (z) is a relatively large value. Conversely, when traveling on a curve, the curvature βz ahead of the vehicle changes according to the degree of the curve, and the lane maintenance continuable speed estimated value VL (z) calculated based on this also changes ( Step S6).
[0055]
Then, the smaller one of the traveling speed for securing the target inter-vehicle distance Lc calculated based on the inter-vehicle distance Lx, the target inter-vehicle distance Lc, and the relative speed dLx with the preceding vehicle and the set vehicle speed Vc is set as the target. The vehicle speed Vs is set, and the target acceleration Xgs is calculated based on the vehicle speed Vs (steps S7 and S8).
When the set vehicle speed Vc is smaller than the lane maintaining continuable speed VL, or when the set vehicle speed Vc is equal to or higher than the lane maintaining continuable speed VL and there is a preceding vehicle and the vehicle speed is slower than the set vehicle speed Vc, the target vehicle speed The target acceleration Xgs based on Vs is set as the target acceleration correction value Xgsh, and when the preceding vehicle does not exist or when the vehicle speed of the preceding vehicle is higher than the set vehicle speed Vc, the lane maintaining continuable speed VL and the corresponding forward distance Based on ZL, acceleration Xg for allowing the speed at the forward distance ZL position to be the lane maintaining continuable speed VL _ZL Is calculated, and the smaller of this and the target acceleration Xgs is set as the target acceleration correction value Xgsh (step S9). That is, the target acceleration Xgs is changed to the acceleration Xg. _ZL Limit to.
[0056]
In order to obtain the target acceleration correction value Xgsh, the target braking fluid pressure Pws _j The target drive torque Tes is calculated, and a control signal corresponding to the calculated target drive torque Tes is output to the brake fluid pressure control device 13, the engine control device 11, and the transmission control device 12 (steps S10 to S12). Further, a control signal is transmitted to the steering control device 14 in order to generate the target steering torque Tref.
[0057]
As a result, the target steering torque Tref for causing the vehicle to travel along the traveling lane is added to the steering shaft 6, so that the driver can maintain the traveling lane only by applying a relatively small steering torque. You can travel.
Further, since the traveling speed is controlled so that the distance between the preceding vehicle and the preceding vehicle travels while maintaining a predetermined target inter-vehicle distance Lc, and when the preceding vehicle does not exist, the traveling speed is controlled. And the target inter-vehicle distance Lc is maintained, and the vehicle travels at the set vehicle speed Vc.
[0058]
Here, when the vehicle follows a preceding vehicle and travels on a straight road, the curvature βz is relatively small, and thus the lane maintaining continuable speed VL becomes a relatively large value. At this time, the set vehicle speed Vc or The target acceleration Xgs calculated based on the inter-vehicle distance from the preceding vehicle is the acceleration Xg calculated based on the lane maintaining continuable speed VL. _ZL If the speed is smaller than the vehicle speed, the inter-vehicle distance control is performed based on the set vehicle speed Vc or the target acceleration Xgs, which is an acceleration capable of maintaining the inter-vehicle distance at the target inter-vehicle distance Lc.
[0059]
From this state, as shown by the solid line in FIG. _Four The curve where the estimated vehicle speed VL (z) that can maintain the lane is the minimum, that is, the time t _Four When the vehicle enters a curve where the curvature of the curve reaches a peak, the estimated lane-sustainable speed VL (z) at five points Z1 to Z5 ahead of the vehicle becomes a different value depending on the curvature βz at each point. The smallest value of the estimated lane maintenance continuable speed VL (z) at the point is set as the lane maintenance continuable speed VL, and the vehicle travels at the forward point ZL where the lane maintenance continuable speed VL is reached. Acceleration Xg for the speed to be the lane maintaining continuable speed VL _ZL Is calculated.
[0060]
At this time, if the curve curvature is relatively small and the lane maintaining continuable speed VL is large, the acceleration Xg _ZL Is larger than the target acceleration Xgs that can satisfy the set vehicle speed Vc in order to maintain the target inter-vehicle distance Lc, so that the target acceleration Xgs is selected as the target acceleration correction value Xgsh.
Accordingly, the speed control is performed so that the travel speed for maintaining the target inter-vehicle distance Lc or the set vehicle speed Vc is achieved, and the inter-vehicle distance control is performed.
[0061]
As the vehicle advances, if the curvature of the curve increases, the estimated lane maintenance continuable speed VL (z) decreases accordingly, while the lane maintenance continuable speed VL is greater than the set vehicle speed Vc. Since the target acceleration Xgs is set as the target acceleration correction value Xgsh and the target acceleration Xgs is not corrected, when the preceding vehicle is traveling at a constant speed, the host vehicle also travels at a constant speed.
[0062]
And time t ₁ When the estimated lane maintaining continuable speed estimated value VL (z) falls below the set vehicle speed Vc, the lane maintaining continuable speed VL set based on the estimated lane maintaining continuable speed VL (z) falls below the set vehicle speed Vc. The target acceleration Xgs is not corrected while the preceding vehicle is traveling at a speed lower than the set vehicle speed Vc. Therefore, the host vehicle continues to travel at a constant speed.
[0063]
Then, from a state where the lane maintaining continuable speed VL is lower than the set vehicle speed Vc and traveling at a constant speed following the preceding vehicle, the time t ₂ When the preceding vehicle no longer exists due to the lane change or the like, the set vehicle speed Vc is set as the target vehicle speed Vs. At this time, since there is no preceding vehicle, time t ₂ The acceleration Xgs at which the speed at the forward point ZL corresponding to the lane maintaining continuable speed VL, which is set at _ZL However, when the acceleration is larger than the target acceleration Xgs based on the set vehicle speed Vc, the target acceleration Xgs is not corrected. In the case of FIG. 4, time t ₂ As shown in FIG. 5, the curvature βz at the vehicle front position in FIG. 5 has the maximum curvature βz at the point of the forward distance Z4. Therefore, the lane maintenance continuable speed estimated value VL (z) at this point is the lane maintenance continuable speed VL. Set as
[0064]
The acceleration Xg for allowing the vehicle speed V at the vehicle front position Z4 corresponding to the lane maintaining continuable speed VL to become the lane maintaining continuable speed VL. _ZL Is calculated, and this acceleration Xg _ZL And the target acceleration Xgs, whichever is smaller, is set as the target acceleration correction value Xgsh, but the curvature is relatively small and the acceleration Xg _ZL Is larger than the target acceleration Xgs, the target acceleration Xgs is set as the target acceleration correction value Xgsh and acceleration is performed at the target acceleration Xgs so that the traveling speed V becomes the set vehicle speed Vc. It increases with the slope of Xgs.
[0065]
Then, the vehicle travels and time t _Three And acceleration Xg _ZL Is below the target acceleration Xgs, the acceleration Xg _ZL Is set as the target acceleration correction value Xgsh, and this acceleration Xg _ZL Control is performed so as to satisfy Therefore, the traveling speed V increases gently.
And acceleration Xg _ZL While X is below the target acceleration Xgs, the acceleration Xg _ZL Is set as the target acceleration correction value Xgsh, whereby the traveling speed V increases slowly and the time t _Five Acceleration Xg _ZL Exceeds the target acceleration Xgs, the target acceleration Xgs is set as the target acceleration correction value Xgsh, and thereafter the traveling speed V increases with the inclination of the target acceleration Xgs.
[0066]
Here, in the lane keeping control process, the curvature βz of the curve at the gazing point ahead of the vehicle ₀ Is calculated based on the target steering torque Tref, and the curve curvature βz reaches a peak point t. _Three To time t _Five In the vicinity, the target steering torque Tref increases. At this time, time t ₂ Since the preceding vehicle no longer exists, the host vehicle starts to accelerate. However, if the lateral acceleration Yg increases as the traveling speed V is accelerated, the lane is maintained only by generating the target steering torque Tref. May not be possible.
[0067]
However, at time t _Three To time t _Five During the period, the target acceleration Xgs is the acceleration Xg _ZL The travel speed V increases slowly. At this time, acceleration Xg _ZL Is based on the curvature in front of the vehicle, and is set to an acceleration at which the traveling speed V at this time can become the lane maintaining continuable speed VL when the vehicle reaches the vehicle front position ZL corresponding to the lane maintaining continuable speed VL. Therefore, when passing the vehicle front position ZL, it is limited to a speed at which the lane can be maintained. Therefore, it is avoided that the own vehicle deviates from the lane with the acceleration of the own vehicle by the inter-vehicle distance control, and the release of the lane keeping control due to the control by the inter-vehicle distance control is avoided.
[0068]
At this time, the curvature at a plurality of points is detected for the curve ahead of the vehicle, and the lane maintaining continuable speed estimation value VL (z) based on this is minimized, that is, the curvature among the detected plurality of curvatures is the maximum. Are sequentially selected, and acceleration control is performed based on the selection. Therefore, the acceleration from the time when the host vehicle passes the peak of the curve can be quickly returned, and the traveling speed V can be quickly increased. It is possible to control to the set vehicle speed Vc.
[0069]
In the first embodiment, the set vehicle speed Vc is larger than the estimated lane maintaining speed VL, and there is no preceding vehicle or the preceding vehicle is faster than the set vehicle speed Vc. The target acceleration Xgs is limited only when acceleration control is performed so that becomes the set vehicle speed Vc. Therefore, the lane keeping control is maintained only when the preceding vehicle accelerates or no longer exists, for example, when the preceding vehicle disappears during the following traveling or when the preceding vehicle accelerates during the following traveling. When the vehicle exists and the preceding vehicle is traveling at a lower speed than the set vehicle speed Vc, the target acceleration Xgs is not limited. Therefore, since the target acceleration Xgs is limited only when the condition is satisfied, it is possible to avoid the illusion that the driver can perform automatic driving by performing lane keeping control. it can.
[0070]
In the first embodiment, the target acceleration Xgs is limited, but the target vehicle speed Vs is corrected based on the magnitude relationship between the set vehicle speed Vc and the lane maintaining continuable speed VL. On the basis of the target acceleration Xgs, the target braking fluid pressure Pws is obtained in order to obtain the target acceleration Xgs. _j Alternatively, the target drive torque Tes may be calculated to control the brake fluid pressure control device 13, the engine control device 11, and the transmission control device 12, and in this case, the same effect as described above can be obtained.
[0071]
Here, the processes in steps S4, S7, S8, and S10 to S12 in FIG. 2 correspond to the inter-vehicle distance control means, the process in the steering control device 14 corresponds to the automatic steering means, and the processes in steps S5 and S12 maintain the lane. Corresponding to the control means, the monocular camera 15a and the image processing device 15 correspond to the vehicle forward detection means and the road environment detection means, the processing in step S6 in FIG. 2 corresponds to the lane maintaining speed estimation means, and the processing in step S9. Corresponds to the inter-vehicle distance control limiting means.
[0072]
Next, a second embodiment of the present invention will be described.
In the second embodiment, a navigation system 25 (road information processing means) is added to the first embodiment as shown in FIG. For example, the navigation system 25 detects the current position of the host vehicle by GPS, detects road environment information around the host vehicle based on map information stored and held in advance, and outputs this to the automatic travel control device 10. is doing. As the road information, for example, the position Xn of the own vehicle (n indicates the calculation timing), the curvature α of the road around the own vehicle, the road gradient θ, and the cant φ are output.
[0073]
And in this 2nd Embodiment, the automatic travel control apparatus 10 performs the arithmetic processing of automatic travel control based on the flowchart of FIG. In addition, the same code | symbol is provided to the same part as the said 1st Embodiment, and the detailed description is abbreviate | omitted.
In the calculation process of the automatic travel control in the second embodiment, a process for determining the continuation of the curve in step S6a is added to the calculation process of the automatic travel control in the first embodiment.
[0074]
That is, in the second embodiment, when various data are read in step S1a, various data are read in the same manner as in the first embodiment, and the navigation system 25 automatically reads the road environment information. The vehicle's current position X (n), road curvature αs, road gradient θs, and cant φs at each point in the forward direction based on the current position X (n) are read. Then, this is stored in a storage area (not shown).
[0075]
Note that s is a data number and depends on the data point interval of the road map data held by the navigation system 25.
Then, in the same manner as in the first embodiment, the processing of step S2 to step S6 is executed, the lane maintaining continuable speed VL is calculated in step S6, and then the process proceeds to step S6a. A curve continuation determination process is performed based on the road environment information.
[0076]
That is, first, based on the road environment information stored in the storage area, the road curvature αz, road gradient θz, and cant φz at the movement amount Xmz position ahead of the host vehicle with respect to the current position Xn of the host vehicle are detected. These can be expressed as a function of the movement amount Xmz with the current position Xn of the host vehicle as a reference, as shown in the following equation (5).
αz = p (Xmz)
θz = h (Xmz)
φz = g (Xmz) (5)
Note that the movement amount Xmz can be calculated by a sum obtained by adding the distance Lmk between data points on the map from k = 1 to k = z.
[0077]
Then, it is determined whether or not the lane maintaining continuable speed VL is further reduced with respect to the lane maintaining continuable speed VL calculated in the process of step S6. In other words, the road curvature αz, road gradient θz, and cant φz at the above-mentioned travel amount Xmz position in front of the host vehicle are sequentially searched, and the forward position ZL position corresponding to the lane maintaining continuable speed VL used in step S6. , While the movement amount Xmz is larger than the ZL position and the end position of the same curve, that is, until the curvature αz exceeds a curvature threshold that can be regarded as the end of the curve, the curvature αz is It is determined whether or not there is a point that is larger than the curvature βz at the forward position ZL. If there is a point where the curvature αz is larger than the curvature βz, it is determined that the curve is continued, and the curve continuation flag Fcr is set to Fcr = ON, and if there is no corresponding point, the curve is not continued. And the curve continuation flag is set to Fcr = OFF.
[0078]
Then, similarly to the first embodiment, steps S7 and S8 are executed to calculate the target vehicle speed Vs and the target acceleration Xgs, and then the process proceeds to step S9a.
In this step S9a, the target acceleration Xgs is corrected and the target acceleration correction value Xgsh is calculated in the same manner as in the first embodiment. At this time, depending on whether the curve continues, the acceleration Xg _ZL Offset amount Xg in equation (4) for calculating _OFF Has changed.
[0079]
That is, when the curve continuation flag is Fcr = ON, Xg _OFF = Xg _OFF0 X2. On the other hand, when Fcr = OFF, Xg _OFF = Xg _OFF0 And Xg _OFF0 Is a reference offset amount and a constant.
And the offset amount Xg set in this way _OFF Acceleration Xg according to the equation (4) _ZL Is calculated.
[0080]
Then, in the same manner as in the first embodiment, the target acceleration correction value is set according to the magnitude relationship between the set vehicle speed Vc and the lane maintaining continuable speed VL and the magnitude relationship between the set vehicle speed Vc and the vehicle speed of the preceding vehicle. Set Xgsh.
Then, the process proceeds to step S10, and thereafter the target braking fluid pressure Pws is performed in the same manner as in the first embodiment. _j The target drive torque Tes is calculated, and a control signal corresponding to the calculated target drive torque Tes is output to the brake fluid pressure control device 13, the engine control device 11, and the transmission control device 12 (steps S10 to S12). Further, a control signal is transmitted to the steering control device 14 in order to generate the target steering torque Tref.
[0081]
Thus, in the second embodiment, it is possible to recognize how the curve will change in the future by using the road environment information of the navigation system 25.
Therefore, if the curve continues, set the offset amount to Xg _OFF = Xg _OFF0 X2 is set to a larger value, thereby increasing the acceleration Xg _ZL Is set smaller and the target acceleration correction value Xgsh is suppressed to be smaller, so that acceleration can be suppressed at an earlier time point in consideration of the continuation state of the curve. Here, as described above, in the autonomous forward detection in which the curvature β of the traveling lane is calculated by the image processing device 15 using the monocular camera 15a or the like, when the curve is narrowed, If the preceding vehicle disappears during the turn, the traveling speed V reaches the lane maintaining continuable speed VL in some cases, and the vehicle is not accelerated at all, which may cause the passenger to feel a little uncomfortable. .
[0082]
However, in the second embodiment, since acceleration is suppressed at an earlier time according to the continuation state of the curve, it is possible to perform natural and continuous acceleration, giving the passenger a sense of incongruity. You can avoid that.
In the second embodiment as well, the set vehicle speed Vc is larger than the estimated lane maintaining speed VL, and there is no preceding vehicle or the preceding vehicle is faster than the set vehicle speed Vc. Further, the traveling speed V Since the target acceleration Xgs is limited only when the acceleration control is performed so that the vehicle speed becomes the set vehicle speed Vc, an illusion that the driver can perform the automatic driving by performing the lane keeping control. You can avoid having it.
[0083]
In the second embodiment, the case where the road environment information from the navigation system 25 is used only for the curve continuation determination has been described. However, when the lane maintaining continuable speed VL is calculated in step S6. Instead of the curvature β of the traveling lane from the image processing device 15, the accuracy α is slightly reduced, but the curvature αs from the navigation system 25 may be used.
[0084]
Thus, by calculating the lane maintaining continuable speed VL using the curvature αs from the navigation system 25, it is possible to obtain the curvature αs in a wider range than when using the curvature β from the image processing device 15. Therefore, acceleration can be suppressed more accurately.
Next, a third embodiment of the present invention will be described.
[0085]
The third embodiment is the same as the second embodiment except that the processing procedure of the arithmetic processing of the automatic travel control is different. That is, in the third embodiment, processing is performed according to the flowchart shown in FIG. In addition, the same code | symbol is provided to the same part as the said 2nd Embodiment, and the detailed description is abbreviate | omitted.
[0086]
In the third embodiment, as in the second embodiment, first, various data are read in step S1a, and the traveling speed V, the relative speed dLx, and the target inter-vehicle distance Lc are calculated based on the data. (Steps S2 to S4).
Next, the process proceeds to step S4a, and a curve continuation determination process is performed. The curve continuation determination process in the third embodiment is performed as follows. First, in accordance with the curvature αs ahead of the vehicle, the necessary steering torque Tws that will be required in the future at each data point position is estimated based on the following equation (6) (necessary steering torque detecting means). By estimating the required steering torque Tws for a preset number of data point positions, the required steering torque Tws in a part of the curve ahead of the vehicle is estimated.
[0087]
Tws = q (Ygrs)
Ygrs = Vrs ² ・ Αs
Vrs = (V ² + 2 · a · Xms) ^1/2 ...... (6)
Here, V is the current traveling speed, a is the acceleration calculated in the inter-vehicle distance control, Xms is the vehicle forward distance from the current position to the position where the curvature of the curve is αs, and Vrs is the vehicle forward distance Xms. Ygrs is an estimated lateral acceleration at the time when the vehicle reaches the vehicle forward distance Xms. Further, the function q (Ygrs) has, for example, the characteristics shown in FIG. 9, and the required steering torque Tws increases in a parabolic manner as the absolute value of the left-right acceleration estimated value Ygrs increases. This characteristic is converted into map data, and the necessary steering torque Tws is uniquely estimated from the calculated lateral acceleration estimated value Ygrs.
[0088]
Strictly speaking, the acceleration a in the inter-vehicle distance control is the target acceleration Xgs described above, and varies depending on the set vehicle speed Vc and the like, but here, a fixed value a is used for simplicity.
Next, as shown in FIG. 10, the required steering torque Tws is the maximum value Tlim of the steering torque limit value Tlim. _MAX Exceeding time t _OVER Is calculated. That is, first, Tws> Tlim _MAX And the estimated vehicle speed Vrs when the vehicle has reached the vehicle forward distance Xms is Vrs. ₀ And then Tws ≦ Tlim _MAX Vrs when Vrs becomes ₁ And Vrs set in this way ₀ And Vrs ₁ From the following equation (7), the time t _OVER Is calculated.
[0089]
t _OVER = (Vrs ₁ -Vrs ₀ ) / A (7)
Next, the upper time t _OVER Is the preset specified value t _OVER The curve continuation determination is performed based on whether or not it is greater than L. That is, t _OVER > T _OVER When L, it is determined that the curve continues, and the curve continuation flag Fcr is set to Fcr = ON. Conversely, t _OVER ≦ t _OVER When L, it is determined that the curve is not continued, and the curve continuation flag Fcr is set to Fcr = OFF.
[0090]
Next, the process proceeds to step S4b, and the maximum value Tlim of the steering torque limit value Tlim is reached. _MAX Is changed (steering torque limit value changing means). In other words, if it is determined in step S4a that the curve does not continue, the lane keeping control can be continued by increasing the steering torque limit value Tlim only for a short time, and therefore the steering torque limit value Tlim. Maximum value of Tlim _MAX To change. On the other hand, if it is determined that the curve continues, the driver may be given the illusion that any curve can be passed. _MAX No changes are made.
[0091]
Maximum value Tlim _MAX Is changed to the maximum value of the necessary steering torque Tws in the part of the curve ahead of the vehicle calculated in the process of step S4a and the upper limit value Tlim when the steering torque limit value Tlim is temporarily increased. _H The smaller one of these is calculated as the maximum correction value Tlim. _MAX Set as ′. Maximum correction value Tlim _MAX 'Is the upper limit Tlim _H By limiting the necessary steering torque Tws, it is possible to prevent the driver from feeling uncomfortable by increasing the necessary steering torque Tws indefinitely.
[0092]
Next, the process proceeds to step S4c, and the target steering torque Tref is calculated. For example, the yaw angle Φ with respect to the traveling lane of the host vehicle, the lateral displacement amount X, and the curvature βz of the gazing point of the forward traveling lane ₀ , Gradient θz ₀ , Cant φz ₀ The sum of the values obtained by multiplying the control gains Ka, Kb, Kc, Kd, and Ke that change according to the traveling speed V (= Ka · Φ + Kb · X + Kc · βz) ₀ + Kd · θz ₀ + Ke · φz ₀ ) And the steering torque limit value Tlim, whichever is smaller is set as the target steering torque Tref.
[0093]
Thus, by using the road gradient θs and cant φs in front of the vehicle obtained from the navigation system 25, the lane keeping performance by the lane keeping control can be further improved.
The steering torque limit value Tlim is the maximum value Tlim of the steering torque limit value Tlim in step S4b. _MAX Is set according to the left-right acceleration | Yg | according to the characteristic diagram as shown in FIG. 11, for example.
[0094]
For example, as shown in FIG. 11, this characteristic diagram differs from the characteristic diagram of the steering torque limit value Tlim shown in FIG. 3 described above when the lateral acceleration Yg is generated in the same direction as the turning direction. The lateral acceleration Yg is Yg (T _MAX ), The steering torque limit value Tlim continues to increase at the same slope, and the steering torque limit value Tlim is corrected to the maximum correction value Tlim. _MAX When reaching ′, it is set to decrease in a parabolic manner.
[0095]
When the target steering torque Tref is set in this way, the process proceeds to step S7, and thereafter, the same processing as in the second embodiment is performed to calculate the target vehicle speed Vs that can secure the target inter-vehicle distance Lc. (Step S7), the target acceleration Xgs is calculated (Step S8). Then, the process proceeds to step S10a without correcting the target acceleration Xgs, and the target acceleration Xgs calculated in step S8 is regarded as the target acceleration correction value Xgsh, and based on this, the target braking fluid pressure Pws is determined. _j (Step S10), the target drive torque Tes is calculated (step S11), and the target braking fluid pressure Pws calculated in step S10 is calculated. _j The target drive torque Tes calculated in step S11 is output to the brake fluid pressure control device 13, the engine control device 11, and the transmission control device 12. Further, the target steering torque Tref calculated in step S4c is output to the steering control device 14, and the set vehicle speed Vc is displayed on the display 23, and then the process returns to the main program (step S12).
[0096]
Therefore, in the third embodiment, the required steering torque Tws that will be required in the future is estimated based on the curvature αs of the road ahead of the vehicle and the acceleration a in the inter-vehicle distance control, and the required steering torque Tws is calculated as the steering torque limit value. Maximum value of Tlim Tlim _MAX The continuation judgment of the curve is made from the time exceeding. When it is determined that the curve does not continue, that is, when the curve is not a curve or is a curve, but the curve continues only for a short time, the steering torque limit value Tlim becomes the correction maximum value Tlim. _MAX The steering torque limit value Tlim is temporarily increased within a range not exceeding ′.
[0097]
Therefore, when the vehicle starts to accelerate so that the preceding vehicle becomes the set vehicle speed Vc because the preceding vehicle no longer exists while traveling on the curve, depending on the magnitude of the steering torque limit value Tlim and the degree of acceleration by the inter-vehicle distance control, If the steering torque is only applied to the steering shaft 6 within the range of the steering torque limit value Tlim, the lane may not be maintained. However, when it is determined that the curve does not continue, the maximum value Tlim of the steering torque limit value Tlim temporarily. _MAX Is changed to a larger value, a steering torque larger than usual can be applied to the steering shaft 6 and departure from the lane can be avoided. Therefore, the vehicle can pass the curve while performing the lane keeping control, and at this time, the necessary steering torque Tws is calculated based on the acceleration a in the inter-vehicle distance control. Lane maintaining control can be continued even when accelerating while driving on a curve.
[0098]
In the third embodiment, the maximum value Tlim of the steering torque limit value Tlim. _MAX However, only the maximum value Tlim of the steering torque limit value Tlim is combined with the first or second embodiment. _MAX May be changed to a larger value, and the traveling speed and acceleration in the inter-vehicle distance control may be limited. Thus, by adjusting not only the steering torque but also the traveling speed and acceleration, the steering torque limit value Tlim can be set to a relatively small value, and the final upper limit value upper limit value Tlim can be set. _H Can reduce the likelihood of reaching.
[0099]
In the second and third embodiments, the case where the navigation system 25 is used has been described. However, the present invention is not limited to this. For example, information reception for communicating with infrastructure equipment installed on the road side is possible. Means may be provided in the host vehicle to communicate with infrastructure equipment to obtain vehicle surrounding environment information.
[0100]
Further, in each of the above-described embodiments, the case where feedback control is used for the part that controls the host vehicle speed based on the inter-vehicle distance from the preceding vehicle has been described. However, the present invention is not limited to this. A combination of feedback control and feedforward control may be applied as described in the November 1999 issue (P98 to P103, “Development of an automatic inter-vehicle control system”, Iijima et al.). That is, the present invention relates to control for changing the target inter-vehicle distance, and various control laws can be applied to the control of the inter-vehicle distance.
[Brief description of the drawings]
FIG. 1 is a vehicle configuration diagram showing an example of a vehicle equipped with a comprehensive vehicle control device to which the present invention is applied.
FIG. 2 is a flowchart showing a calculation process for automatic traveling control performed by the automatic traveling control device 10 of FIG. 1;
FIG. 3 is a characteristic diagram showing a correspondence between a lateral acceleration | Yg | and a steering torque limit value Tlim.
FIG. 4 is a timing chart for explaining the operation of the first embodiment.
FIG. 5 is a timing chart for explaining the operation of the first embodiment;
FIG. 6 is a vehicle configuration diagram showing an example of a vehicle provided with a vehicle comprehensive control apparatus according to a second embodiment.
FIG. 7 is a flowchart showing a calculation process for automatic traveling control in the second embodiment.
FIG. 8 is a flowchart showing a calculation process for automatic travel control in the third embodiment.
FIG. 9 is a characteristic diagram showing characteristics of a function q (Ygri) for calculating a necessary steering torque Tws based on an estimated lateral acceleration value Ygri.
FIG. 10: Overshoot time t _OVER It is explanatory drawing with which it uses for description.
FIG. 11 is a characteristic diagram showing a correspondence between a lateral acceleration | Yg | and a steering torque limit value Tlim in the third embodiment.
[Explanation of symbols]
1FL ~ 1RR wheel
2 Engine
3 Automatic transmission
4FL-4RR Wheel cylinder
5 Steering wheel
6 Steering shaft
9 Manual switch
10 Automatic travel control device
11 Engine control device
12 Transmission control device
13 Braking fluid pressure control device
14 Steering control device
15 Image processing device
15a monocular camera
16 Inter-vehicle distance sensor
17 Wheel speed sensor
18 Accelerometer
19 Braking fluid pressure sensor
20 Accelerator position sensor
21 Brake pedal
22 Master cylinder
23 display
25 Navigation system

Claims (9)

An inter-vehicle distance control means for controlling the speed of the own vehicle so that the inter-vehicle distance between the own vehicle and the preceding vehicle coincides with the target inter-vehicle distance;
Automatic steering means capable of controlling the steering torque regardless of the driver's steering operation;
Lane maintaining control means for controlling the automatic steering means within a range of a limit value of the steering torque so that the host vehicle travels while maintaining the lane,
In the vehicle overall control device, the limit value of the steering torque is set to a value at which the driver does not let go of the steering wheel even when the steering torque is controlled by the lane keeping control means .
Road environment detection means for detecting road conditions ahead of the vehicle;
Based on the road conditions ahead of the vehicle detected by the road environment detection means, the lane maintenance continuable speed estimation is performed to estimate the lane maintenance continuable speed capable of maintaining the lane within the range of the steering torque limit value. Means,
When the inter-vehicle distance control means and the lane keeping control means are operating together, an inter-vehicle distance control restricting means for restricting the vehicle speed controlled by the inter-vehicle distance control means according to the lane keeping continuable speed; A vehicle overall control device comprising:   The inter-vehicle distance control limiting unit detects a continuation state of a curve ahead of the vehicle based on a road condition ahead of the vehicle detected by the road environment detection unit, and according to the continuation state of the curve and the lane maintenance continuation possible speed The vehicle overall control apparatus according to claim 1, wherein the vehicle speed controlled by the inter-vehicle distance control means is limited.   The road environment detection means is provided on the lane keeping control means and detects the vehicle position in the traveling lane, and detects the current position of the own vehicle and stores the vehicle information based on map information stored in advance. 3. The vehicle according to claim 2, wherein the vehicle is at least one of road information processing means for detecting road information around the vehicle and information receiving means for receiving information on a road surface condition ahead of the host vehicle from the information providing device. Integrated control device.   The lane maintaining continuable speed estimating means estimates the lane maintaining continuable speed from road information ahead of the vehicle detected by the road information processing means or the information receiving means and a limit value of the steering torque. The vehicle comprehensive control device according to claim 3, wherein   5. The vehicle total control according to claim 1, wherein the inter-vehicle distance control limiting unit limits the vehicle speed in the inter-vehicle distance control unit by limiting an acceleration. apparatus.   The inter-vehicle distance control restricting means depends on the lane maintaining continuable speed, the distance to the vehicle forward position where the speed of the host vehicle is predicted to reach the lane maintaining continuable speed, and the current speed of the host vehicle. The vehicle overall control apparatus according to claim 5, wherein the acceleration is limited. The inter-vehicle distance control means is a means for controlling the speed of the host vehicle to be equal to or lower than a set vehicle speed and performing speed control so as to be the set vehicle speed when the preceding vehicle does not exist.
The inter-vehicle distance control limiting means limits the speed or acceleration of the own vehicle only when the acceleration control is performed by the inter-vehicle distance control means so that the speed of the own vehicle becomes the set vehicle speed. The vehicle comprehensive control device according to any one of claims 1 to 6. Necessary steering for detecting the continuation state of the curve ahead of the vehicle based on the road condition in front of the vehicle detected by the road environment detection means, and detecting the steering torque required when passing the curve based on the continuation state of the curve Torque detection means;
Torque excess duration predicted when the required steering torque detected by the required steering torque detection means exceeds the steering torque limit value when both the inter-vehicle distance control means and the lane keeping control means are operating. And a steering torque limit value changing means for changing the steering torque limit value to a larger value when the torque excess duration is within a preset allowable value. The vehicle comprehensive control device according to any one of 1 to 7. An inter-vehicle distance control means for controlling the speed of the own vehicle so that the inter-vehicle distance between the own vehicle and the preceding vehicle coincides with the target inter-vehicle distance;
Automatic steering means capable of controlling the steering torque regardless of the driver's steering operation;
Lane keeping control means for controlling the automatic steering means within the range of the steering torque limit value so that the host vehicle travels while maintaining the lane, and the steering torque limit value is the lane keeping value. In the vehicle overall control device set to a value that does not allow the driver to release the steering wheel even when the steering torque is controlled by the control means ,
Road environment detection means for detecting road conditions ahead of the vehicle;
Necessary steering for detecting the continuation state of the curve ahead of the vehicle based on the road condition ahead of the vehicle detected by the road environment detection means, and detecting the steering torque required when passing the curve based on the continuation state of the curve Torque detection means;
Torque excess duration predicted when the required steering torque detected by the required steering torque detection means exceeds the steering torque limit value when both the inter-vehicle distance control means and the lane keeping control means are operating. And a steering torque limit value changing means for changing the limit value of the steering torque to a larger value when the torque excess duration is within a preset allowable value. Integrated control device.

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