JP3630124B2 - Leading vehicle tracking control device - Google Patents

Description

【００３０】
【表２】

【００３１】
また、目標車間距離演算部３４は、追従制御モード選択部３２で選択された追従制御モードに対応づけられているフィルタであって、目標車間距離演算用定数決定部３３で決定された減衰係数ζ_Ｔ及び固有振動数ω_Ｔで係数が設定されているものを用いて、車間距離指令値演算部３１で算出された車間距離指令値Ｌ^＊と先行車両を補足したとき等に設定される車間距離Ｌ_ｏとに基づいて、目標車間距離Ｌ_Ｔと目標相対速度△Ｖ_Ｔを演算して、それらの演算結果を車速指令値演算部３５に出力する処理を行う。なお、追従制御モード０は、２次遅れ形式のローパスフィル夕に対応し、追従制御モード１は、むだ時間を含む２次遅れ形式のローパスフィル夕に対応し、追従制御モード２は、非最小位相系の伝達関数で表される逆応答フィル夕に対応する。
【００３２】
さらに、車速指令値演算部３５は、目標車間距離演算部３４で算出された目標車間距離Ｌ_Tと目標相対速度△Ｖ_Tに基づいて、車速指令値Ｖ^*を下記（３）式に従って算出し、その算出結果を車速制御部３６に出力する処理を行う。
Ｖ^*＝Ｖ（ｔ）＋△Ｖ（ｔ）−〔ｆ_V｛△Ｖ_T（ｔ）−△Ｖ（ｔ）｝＋ｆ_L｛Ｌ_T（ｔ)−Ｌ(ｔ)｝〕 ………（３）
但し、ｆ_V及びｆ_Lは定数である。
【００３３】
そして、車速制御部３６は、車速指令値演算部３５で算出された車速指令値Ｖ^＊に自車速Ｖを一致させるためのスロットル開度指令値、制動油圧指令値及び変速指令値を演算し、それらをエンジン出力制御装置９、制動制御装置８及び変速機制御装置１１に出力する。車速指令値Ｖ^＊に自車速Ｖを一致させるための演算方法としては、フィードバック制御手法や、特開２０００−１３５９３４号公報に記載のロバストモデルマッチング制御手法等、種々の制御手法を用いることができる。
【００３４】
次に、図２の追従制御モード選択部３２で行われる処理を図３のフローチャートに基づいて詳細に説明する。この処理が実行されると、まずそのステップＳ１では、追従制御モード０が選択されていたか否か判定し、追従制御モード０が選択されていたときには（Ｙｅｓ）ステップＳ２に移行し、そうでないときには（Ｎｏ）ステップＳ８に移行する。なお、初期状態においては、追従制御モードの種類として追従制御モード０が選択されていたものとする。
【００３５】
前記ステップＳ２では、車速センサ１３で検出された自車両の車速Ｖが「０」であるか否か判定し、「０」であるときには（Ｙｅｓ）ステップＳ３に移行し、そうでないときには（Ｎｏ）この処理を終了する。
前記ステップＳ３では、車間距離センサ１２で検出された相対速度△Ｖが「０」であるか否か判定し、「０」であるときには（Ｙｅｓ）ステップＳ４に移行し、そうでないときには（Ｎｏ）この処理を終了する。
【００３６】
前記ステップＳ４では、車間距離センサ１２で検出された停車時の車間距離Ｌ_ｏが車間距離指令値演算部３１で算出された車間距離指令値Ｌ_ｏ ^＊より小さい（Ｌ_ｏ＜Ｌ_ｏ ^＊）か否かを判定し、小さいときには（Ｙｅｓ）ステップＳ５に移行し、そうでないときには（Ｎｏ）この処理を終了する。
前記ステップＳ５では、車間距離センサ１２で検出された停車時の車間距離Ｌ_ｏが所定の最低車間距離Ｌ_ｍｉｎより小さい（Ｌ_ｏ＜Ｌ_ｍｉｎ）か否かを判定し、小さいときには（Ｙｅｓ）ステップＳ６に移行し、そうでないときには（Ｎｏ）ステップＳ７に移行する。
【００３７】
前記ステップＳ６では、追従制御モードの種類として追従制御モード１を選択してから、この処理を終了する。
また、前記ステップＳ７では、追従制御モードの種類として追従制御モード２を選択してから、この処理を終了する。
一方、前記ステップＳ８では、車間距離センサ１２で検出された相対速度△Ｖと車速センサ１３で検出された自車速Ｖとに基づき、先行車両の車速Ｖ_ｔを算出して、先行車両が減速しているか否か判定し、減速しているときには（Ｙｅｓ）ステップＳ１０に移行し、そうでないときには（Ｎｏ）ステップＳ９に移行する。
【００３８】
前記ステップＳ９では、車間距離指令値演算部３１で算出された車間距離指令値Ｌ^＊と目標車間距離演算部３４で算出される目標車間距離Ｌ_Ｔとが一致しているか否か判定し、一致しているときには（Ｙｅｓ）前記ステップＳ１０に移行し、そうでないときには（Ｎｏ）この処理を終了する。
また、前記ステップＳ１０では、追従制御モードの種類として追従制御モード０を選択して、この処理を終了する。
【００３９】
次に、図２の目標車間距離演算部３４で行われる処理を図４のブロック図に基づいて詳細に説明する。この処理は、図４に示す制御ブロックを構成しており、その制御ブロックは、車間距離指令値Ｌ^*と減衰係数ζ_T及び固有振動数ω_Tとに基づいて、むだ時間を含むローパスフィル夕で目標車間距離Ｌ_TAを算出する目標車間距離演算部Ａ３４１と、非最小位相系の逆応答フィル夕で目標車間距離Ｌ_TBを算出する目標車間距離演算部Ｂ３４２と、ローパスフィルタで目標車間距離Ｌ_TCを算出する目標車間距離演算部Ｃ３４３と、追従制御モード選択部３２による選択結果に基づいて、それらの目標車間距離演算部３４１、３４２、３４３で算出される目標車間距離Ｌ_TAＬ_TBＬ_TCのいずれかを目標車間距離Ｌ_Tとして車速制御部３６等に出力する追従制御モード切り替え部３４４とを備えている。
【００４０】
これらのうち目標車間距離演算部Ａ３４１は、車間距離指令値演算部３１で算出された車間距離指令値Ｌ^*に基づいて、目標車間距離演算用定数決定部３３で決定された減衰係数ζ_T及び固有振動数ω_Tを有する２次遅れ形式のローパスフィルタにむだ時間要素を含む下記（４）式に従って目標車間距離Ｌ_TA 及び目標相対速度△Ｖ_TAを算出し、その算出結果を追従制御モード切り替え部３４４に出力する。なお、下記（４）式では、車間距離センサ１２で検出された停車時の車間距離Ｌ_o及び相対速度△Ｖ_o を目標車間距離Ｌ_TA及び目標相対速度△Ｖ_TAの初期値とする。
【００４１】
【数１】

【００４２】
また、上記（４）式をラプラス変換すると下記（５）式のように表される。
【００４３】
【数２】

【００４４】
上記（５）式は、車間距離指令値Ｌ^*を入力とし目標車間距離Ｌ_TAを出力としたときの伝達関数であり、むだ時間要素を有するため、図５に示すように、実際の車間距離Ｌ_oよりも大きい車間距離指令値Ｌ^*が入力されてからも、目標車間距離Ｌ_TAとして停車時の車間距離Ｌ_oをむだ時間Ｔにわたり出力する。なお、目標車間距離演算部Ａ３４１のむだ時間Ｔは、図６に示すようなむだ時間マップに従って、図７に示すように、車間距離指令値Ｌ^*と車間距離Ｌとの差を表す偏差率βの大きさに応じて設定する。また、偏差率βは、自車両が停車したときの車間距離指令値Ｌ_o ^*と車間距離Ｌ_oとに基づき、下記（６）式に従って演算する。
【００４５】
β＝（Ｌ_ｏ ^＊‐Ｌ_ｏ）／Ｌ_ｏ ^＊×１００………（６）
但し、Ｌ_ｏ ^＊＞Ｌ_ｏである。
なお、むだ時間Ｔを求める方法は、偏差率βを介するやり方に限定されるものではなく、例えば、停車時の車間距離Ｌ_ｏ等をパラメータとして、予め実験等により乗員のフィーリングと一致するむだ時間Ｔのマップを作成しておき、そのマップを用いて車間距離Ｌ_ｏから直接に求めるようにしてもよい。
【００４６】
また、目標車間距離演算部Ｂ３４２は、車間距離指令値演算部３１で算出された車間距離指令値Ｌ^*に基づいて、目標車間距離演算用定数決定部３３で決定された減衰係数ζ_T及び固有振動数ω_Tを有する非最小位相系のローパスフィルタと、そのローパスフィルタの出力を所定の最低車間距離Ｌ_minで制限するリミッタとを含んで構成される。具体的には、ローパスフィルタは、下記（７）式に従って目標車間距離Ｌ_TB及び目標相対速度△Ｖ_TBを算出し、リミッタは、その算出結果を制限して追従制御モード切り替え部３４４に出力する。なお、下記（７）式では、車間距離センサ１２で検出された停車時の車間距離Ｌ_o及び相対速度△Ｖ_oを目標車間距離Ｌ_TB及び目標相対速度△Ｖ_TBの初期値とする。
【００４７】
【数３】

【００４８】
また、上記（７）式をラプラス変換すると下記（８）式のように表される。
【００４９】
【数４】

【００５０】
上記（８）式は、車間距離指令値Ｌ^*を入力とし目標車間距離Ｌ_TBを出力としたときの伝達関数であり、正の零点「１／α」を有する非最小位相系であるため、図８に示すように、実際の車間距離Ｌ_oよりも大きい車間距離指令値Ｌ^*が入力されると、目標車間距離Ｌ_TBを一旦小さく算出してから徐々に大きく算出する逆揺れの応答をする。その際、最低車間距離Ｌ_minで目標車間距離Ｌ_TBを制限しているため、逆応答フィルタで目標車間距離Ｌ_TBが小さく算出されたとしても、追従制御モード切り替え部３４４に出力される目標車間距離Ｌ_TBが最低車間距離Ｌ_minより短くなってしまうことはない。
【００５１】
なお、目標車間距離演算部Ｂ３４２の逆応答フィル夕の係数αは、図９に示すようなマップに従って、図１０に示すように、停止時の車間距離Ｌ_oと最低車間距離Ｌ_minとの差である車間距離偏差△Ｌ _{om in}の大きさに応じて大きく設定する。また、係数αを求める方法は、車間距離偏差△Ｌ _{om in}を介するやり方に限定されるものではなく、例えば、停車時の車間距離Ｌ_o等をパラメータとして、予め実験等により乗員のフィーリングと一致する係数αのマップを作成しておき、車間距離Ｌ_oから直接に求めるようにしてもよい。
【００５２】
一方、目標車間距離演算部Ｃ３４３は、車間距離指令値演算部３１で算出された車間距離指令値Ｌ^*に基づいて、目標車間距離演算用定数決定部３３で決定された減衰係数ζ_T及び固有振動数ω_Tを有する２次遅れ形式のローパスフィルタを表す下記（９）式に従って目標車間距離Ｌ_Tc及び目標相対速度△Ｖ_Tcを算出し、その算出結果を追従制御モード切り替え部３４４に出力する。なお、下記（９）式では、先行車両を捕捉したときには、捕捉直後の車間距離Ｌ_o及び相対速度△Ｖ_oを目標車間距離Ｌ_Tc及び目標相対速度△Ｖ_Tcの初期値とし、また、追従制御モード１又は追従制御モード２から追従制御モード０に切り替わったときには、切り替わった直後の車間距離Ｌと相対速度△Ｖを初期値とする。
【００５３】
【数５】

【００５４】
また、上記（９）式をラプラス変換すると下記（１０）式のように表される。
【００５５】
【数６】

【００５６】
上記（１０）式は、車間距離指令値Ｌ^*を入力とし目標車間距離Ｌ_TAを出力としたときの伝達関数であり、２次遅れ要素を有するため、図１１に示すように、実際の車間距離Ｌ_oよりも大きい車間距離指令値Ｌ^*が入力されると、目標車間距離Ｌ_TBとして初期値から徐々に大きな値を出力する。
そして、追従制御モード切り替え部３４４は、追従制御モード選択部３２での選択結果に基づいて、その選択された追従制御モードに対応する目標車間距離演算部３４１、３４２、３４３を選択し、その目標車間距離演算部３４１、３４２、３４３が出力している目標車間距離Ｌ_T及び相対速度ΔＶ_Tを車速指令値演算部３５や追従制御モード選択部３２に出力する。具体的には、追従制御モードの種類として追従制御モード０が選択されたときには、目標車間距離演算部Ｃ３４３で算出された目標車間距離Ｌ_Tc及び目標相対速度△Ｖ_Tcを出力し、また追従制御モード１が選択されたときには、目標車間距離演算部Ａ３４１で算出された目標車間距離Ｌ_TA及び目標相対速度△Ｖ_TAを出力し、さらに追従制御モード２が選択されたときには、目標車間距離演算部Ｂ３４２で算出された目標車間距離Ｌ_TB及び目標相対速度△Ｖ_TBを出力する。
【００５７】
次に、本実施の形態の動作を具体的な状況に基づいて詳細に説明する。まず、高速道路を走行中に渋滞が発生し、先行車両に続いて自車両が停車したときに、図１２に示すように、自車両が先行車両に追従して発進させるために、乗員が追従制御を開始させる操作を行ったとする。すると、追従制御用コントローラ２０で追従制御処理が実行され、図２のブロック図に示すように、まず、車間距離指令値演算部３１の処理が実行され、車間距離センサ１２で検出された相対速度△Ｖと車速センサ１３で検出された自車速Ｖとに基づいて車間距離指令値Ｌ^*が算出され、その算出結果が追従制御モード選択部３２、目標車間距離演算用定数決定部３３及び目標車間距離演算部３４に出力される。
【００５８】
次いで、目標車間距離演算用定数決定部３３の処理が実行され、車間距離センサ１２で検出された車間距離Ｌ及び相対速度ΔＶと車間距離指令値演算部３１で算出された車間距離指令値Ｌ^*に基づき、車間距離偏差△Ｌ及び相対速度△Ｖに応じて車間距離制御系の減衰係数ζ_T及び固有振動数ω_Tが決定される。また、同時に、追従制御モード選択部３２の処理も実行され、追従制御モードの種類が追従制御モード０に設定されるため、図３のフローチャートに示すように、まずそのステップＳ１の判定が「Ｙｅｓ」となり、また、先行車両に続いて自車両が停車したため、ステップＳ２及びＳ３の判定も「Ｙｅｓ」となる。そして、渋滞の混雑の度合いが高く、停車時の車間距離Ｌ_oが最低車間距離Ｌ_minより小さくなっているとすると、ステップＳ４及びＳ５の判定も「Ｙｅｓ」となり、ステップＳ６で、追従制御モードの種類として追従制御モード１が選択される。
【００５９】
そして、目標車間距離演算部３４の処理が実行されて、図４のブロック図に示すように、車間距離指令値Ｌ^＊と減衰係数ζ_Ｔ及び固有振動数ω_Ｔとに基づいて、むだ時間を含むローパスフィル夕を有する目標車間距離演算部Ａ３４１で目標車間距離Ｌ_ＴＡが算出され、また、逆応答フィル夕を有する目標車間距離演算部Ｂ３４２で目標車間距離Ｌ_ＴＢが算出され、さらに、ローパスフィルタを有する目標車間距離演算部Ｃ３４３で目標車間距離Ｌ_ＴＣが算出される。次いで、それらの目標車間距離演算部３４１、３４２、３４３で算出される目標車間距離Ｌ_ＴＡＬ_ＴＢＬ_ＴＣのうちから、追従制御モード１に対応づけられている目標車間距離演算部Ａ３４１で算出される目標車間距離Ｌ_ＴＡが、図５に示すように、追従制御モード切り替え部３４４から目標車間距離Ｌ_Ｔとして車速制御部３６等に出力される。
【００６０】
また、目標車間距離Ｌ_T が入力された車速指令値演算部３５では、その目標車間距離Ｌ_Tに基づいて車速指令値Ｖ^*が算出され、車速制御部３６では、その車速指令値Ｖ^*に自車速Ｖを一致させるための制動油圧指令値、スロットル開度指令値及び変速指令値が演算され、それらが制動制御装置８、エンジン出力制御装置９及び変速機制御装置１１に出力される。すると、スロットル開度指令値等を入力されたエンジン出力制御装置９等は、目標車間距離Ｌ^*に実際の車間距離Ｌを一致させるように制駆動力を制御し、先行車両が発進すると、自車両と先行車両との間の車間距離Ｌが停車時と同じ値になるように自車両も発進するため、自車両が置いていかれるといった違和感を乗員に与えてしまうことを抑制防止することができる。
【００６１】
さらに、目標車間距離演算部Ａ３４１で目標車間距離Ｌ_ＴＡを算出する際に、図６に示すように、むだ時間Ｔを、停車時の車間距離Ｌ_ｏと車間距離指令値Ｌ_ｏ ^＊との差の大きさを表す偏差率βに応じて大きく設定するため、例えば、渋滞等で先行車両に続いて自車両が停車したときに、実際の車間距離Ｌと車間距離指令値Ｌ_ｏ ^＊との差が大きいと、図７に示すように、むだ時間Ｔが大きく設定されるので、発進後も、自車両は停車時の車間距離Ｌ_ｏを維持するように追従走行し、先行車両の発進時に、自車両が置いていかれるような違和感を乗員に与えてしまうことを抑制防止できる。
【００６２】
一方、混雑の度合いが低く、停車時の車間距離Ｌ_oが最低車間距離Ｌ_minより大きくなっているとすると、追従制御モード選択部３２の処理が実行されたときに、図３に示すように、ステップＳ１〜Ｓ４を経て、ステップＳ５の判定が「Ｎｏ」となり、ステップＳ７で、追従制御モードの種類として追従制御モード２が選択される。そして、目標車間距離演算部３４では、図４のブロック図に示すように、３種類の目標車間距離演算部３４１、３４２、３４３から出力される目標車間距離Ｌ_TAＬ_TBＬ_TCのうちから、追従制御モード２に対応づけられている目標車間距離演算部Ｂ３４２で算出される目標車間距離Ｌ_TBが、図８に示すように、追従制御モード切り替え部３４４から目標車間距離Ｌ_Tとして車速制御部３６等に出力される。
【００６３】
すると、スロットル開度指令値を入力されたエンジン出力制御装置９等は、目標車間距離Ｌ_Ｔに実際の車間距離Ｌを一致させるように制駆動力を制御し、先行車両が発進したときに、自車両と先行車両との間の車間距離Ｌが停車時よりも小さい値になるように、自車両は先行車よりも大きく加速して発進するので、自車両が置いていかれるような違和感を乗員に与えてしまうことを抑制防止できる。
【００６４】
このように、本実施形態にあっては、発進の初期段階に目標車間距離Ｌ_ＴＢの時間変化率が負になる関数を用いて目標車間距離Ｌ_Ｔを算出するようにしたため、自車両は先行車両よりも大きく加速して発進することになり、先行車両の発進時に、自車両が置いていかれるような違和感を乗員に与えてしまうことを抑制防止できる。
【００６５】
さらに、図９に示すように、目標車間距離Ｌ_Tの時間変化率を表す係数αを、停車時の車間距離Ｌ_oと最低車間距離Ｌ_minとの差を表す車間距離偏差ΔＬ _{om in}の大きさに応じて大きく設定するようにしたため、図１０に示すように、車間距離が大きく、自車両が先行車両に接近してしまう恐れが小さいときには、自車両はより大きく加速して発進するので、自車両が置いていかれるといった違和感を乗員に与えてしまうことを効果的に抑制防止できる。
【００６６】
また、逆応答フィルタを用いて算出した目標車間距離Ｌ_ＴＢを最低車間距離Ｌ_ｍｉｎで制限するため、先行車両の発進時に、自車両が先行車両よりも大きな加速度で発進したとしても、先行車両に最低車間距離Ｌ_ｍｉｎよりも接近してしまうことはなく、運転者に違和感を与えてしまうことを効果的に抑制防止できる。
また、上記フローを繰り返し実行して自車両を加速しているうちに、目標車間距離演算部３４で算出される目標車間距離Ｌ_Ｔが車間距離指令値Ｌ^＊に一致したとする。すると、追従制御モード選択部３２の処理が実行されたときに、図３のフローチャートに示すように、ステップＳ１及びＳ８の判定が「Ｎｏ」となり、また、ステップＳ９の判定が「Ｙｅｓ」となり、ステップＳ１０で、追従制御モードの種類として追従制御モード０が選択される。そして、目標車間距離演算部３４では、図４のブロック図に示すように、３種類の目標車間距離演算部３４１、３４２、３４３から出力される目標車間距離Ｌ_Ｔのうちから、追従制御モード０に対応づけられている目標車間距離演算部Ｃ３４３で算出される目標車間距離Ｌ_ＴＣが、図１１に示すように、追従制御モード切り替え部３４４から目標車間距離Ｌ_Ｔとして車速制御部３６等に目標車間距離Ｌ_Ｔとして出力される。
【００６７】
すると、スロットル開度指令値を入力されたエンジン出力制御装置９等は、目標車間距離Ｌ_Ｔに実際の車間距離Ｌを一致させるように制駆動力を制御し、自車両と先行車両との間の車間距離Ｌが車間距離指令値Ｌ^＊と同じ値にされて、例えば先行車両が加速したときには、自車両も先行車両と同じ又はわずかに遅れて加速するため、先行車両の加減速に対して自車両の追従性を確保することができる。
【００６８】
一方、上記フローを繰り返し実行して自車両を加速しているうちに、目標車間距離演算部３４で算出される目標車間距離Ｌ_Ｔが車間距離指令値Ｌ^＊に一致する前に、再び渋滞が発生して先行車両が減速したとする。すると、追従制御モード選択部３２の処理が実行されたときに、図３のフローチャートに示すように、ステップＳ１を経て、ステップＳ８の判定が「Ｙｅｓ」となり、ステップＳ１０で、追従制御モードの種類として追従制御モード０が選択される。
【００６９】
このように、本実施形態にあっては、先行車両が減速を始めたときに、目標車間距離Ｌ_Ｔを比較的に応答特性の早い関数を用いて設定するようにしたため、自車両と先行車両との間の車間距離Ｌは直ぐに先行車両の減速状況に応じた値に制御され、自車両は先行車両に接近してしまうことはなく、運転者に違和感を与えてしまうことを抑制防止できる。
【００７０】
なお、上記実施の形態においては、車間距離センサ１２は車間距離検出手段及び相対車速検出手段に対応し、車間距離指令値演算部３１は車間距離指令値設定手段に対応し、目標車間距離演算部３４は目標車間距離設定手段に対応し、車速指令値演算部３５及び車速制御部３６は制駆動力制御装置に対応する。
また、上記実施の形態は本発明の先行車両追従制御装置の一例を示したものであり、装置の構成等を限定するものではない。
【００７１】
また、上記実施形態においては、後輪駆動車に本発明を適用した場合について説明したが、前輪駆動車に本発明を適用することもでき、また回転駆動源としてエンジン２を適用した場合について説明したが、これに限定されるものではなく、電動モータを適用することもでき、さらには、エンジンと電動モータとを使用するハイブリッド車にも本発明を適用することができる。
【００７２】
さらに、上記実施形態においては、車間距離センサ１２としてレーザレーダを適用した場合について説明したが、これに限定されるものではなく、ミリ波レーダを適用してもよく、さらにはＣＣＤを使用したステレオカメラの撮像を画像処理して車間距離を求めるようにしてもよい。
またさらに、追従制御用コントローラ２０をマイクロコンピュータ等の離散化されたディジタルシステムで構成した場合について説明したが、これに限定されるものではなく、関数発生器、比較器、演算器等の電子回路を組み合わせて構成するようにしてもよい。
【図面の簡単な説明】
【図１】本発明の先行車両追従制御装置の実施形態を示す概略構成図である。
【図２】図１の追従制御用コントローラで実行される追従処理の具体的構成を示すブロック図である。
【図３】図２の追従制御モード選択部の処理の具体例を示すフローチャートである。
【図４】図２の目標車間距離演算部の処理の具体例を示すブロック線図である。
【図５】むだ時間要素を含むフィルタを用いて算出した目標車間距離の時間変化を示すグラフである。
【図６】偏差率に対するむだ時間のマップ例を示す特性線図である。
【図７】目標車間距離の時間変化のシミュレーション結果であって、むだ時間を変化させて示すグラフである。
【図８】逆応答フィルタを用いて算出した目標車間距離の時間変化を示すグラフである。
【図９】車間距離偏差に対する係数のマップ例を示す特性線図である。
【図１０】目標車間距離の時間変化のシミュレーション結果であって、係数を変化させて示すグラフである。
【図１１】２次遅れ形式のフィルタを用いて算出した目標車間距離の時間変化を示すグラフである。
【図１２】本実施形態の動作状況を説明するための説明図である。
【符号の説明】
１ＦＬ、１ＦＲは前輪
１ＲＬ、１ＲＲは後輪
２はエンジン
３は自動変速機
４はプロペラシャフト
５は最終減速装置
６は車軸
９はエンジン出力制御装置
１０はスロットルアクチュエータ
１１は変速機制御装置
１２は車間距離センサ
１３は車速センサ
２０は追従制御用コントローラ[0001]
BACKGROUND OF THE INVENTION
This invention, PlaceFixed inter-vehicle distance commandIn valueBased onSlipThe present invention relates to a preceding vehicle slave control device that sets a target vehicle distance that changes easily, controls braking / driving force so that the actual vehicle distance matches the target vehicle distance, and causes the host vehicle to follow the preceding vehicle.
[0002]
[Prior art]
Conventionally, as this type of preceding vehicle follow-up control device, for example, the one described in JP 2000-135934 A is known.
In this conventional example, a target inter-vehicle distance is calculated using a low-pass filter of a secondary delay type based on the inter-vehicle distance between the host vehicle and the preceding vehicle and a predetermined inter-vehicle distance command value, and the target inter-vehicle distance Discloses a method of controlling the braking / driving force so that the inter-vehicle distance matches.
[0003]
[Problems to be solved by the invention]
However, in the above conventional example, since the target inter-vehicle distance is calculated using a low-pass filter of the second order lag type, for example, when the own vehicle stops following the preceding vehicle due to traffic jams, the inter-vehicle distance is If it is smaller than the distance command value, even if the host vehicle tries to start following the preceding vehicle, the host vehicle will not start until the inter-vehicle distance exceeds the target inter-vehicle distance. As the preceding vehicle starts, the host vehicle may not start, and the driver feels uncomfortable that the host vehicle is left on the preceding vehicle even though the following control is in progress. There was a problem.
[0004]
Therefore, the present invention has been made paying attention to the unsolved problems of the above-described conventional technology, and it is possible to prevent and prevent the vehicle from leaving a strange feeling when the preceding vehicle starts. It is an object to provide a vehicle following control device.
[0005]
[Means for Solving the Problems]
In order to solve the above-described problem, the preceding vehicle following device according to the first aspect of the present invention sets an inter-vehicle distance detecting means for detecting an inter-vehicle distance between the host vehicle and the preceding vehicle, and a predetermined inter-vehicle distance command value. Inter-vehicle distance command value setting means,in frontThe inter-vehicle distance command set by the inter-vehicle distance command value setting meansIn valueA target inter-vehicle distance setting means for setting a target inter-vehicle distance using a predetermined function, and a target inter-vehicle distance set by the target inter-vehicle distance setting means so that the inter-vehicle distance detected by the inter-vehicle distance detection means matches Braking / driving force control means for controlling braking / driving forceAndPrepared,The target inter-vehicle distance setting means includes an inter-vehicle distance command in which a stop-time inter-vehicle distance detected by the inter-vehicle distance detection means is set by the inter-vehicle distance command value setting means when the host vehicle and the preceding vehicle are stopped. When the value is smaller than the value, when the preceding vehicle starts, the setting of the target inter-vehicle distance is started with the inter-stop distance as an initial value.
Further, the invention according to claim 2 is characterized in that the target inter-vehicle distance setting means sets the target inter-vehicle distance using a function having a slow response characteristic after the preceding vehicle has started.
[0006]
Claims3The invention according to claim2In the preceding vehicle following apparatus, the slow function of the response characteristic includes a function representing dead time.
And claims4The invention according to claim3In the preceding vehicle following device,SaidStopHour carDistance betweenSaidIt is characterized in that it is set larger according to the magnitude of the difference from the inter-vehicle distance command value.
[0007]
Claims5The invention according to claim2In the preceding vehicle following device, the slow function of the response characteristic is a function in which the time change rate of the target inter-vehicle distance at the initial stage of start is negative.
Claims6In the invention according to the present invention, the time change rate of the target inter-vehicle distance at the initial stage of the startSaidStopHour carIt is characterized in that it is set to be large according to the size of the distance.
[0008]
And claims7The invention according to claimAny one of 2-6In the preceding vehicle following device, the target inter-vehicle distance setting means regulates the target inter-vehicle distance calculated by a slow function of the response characteristic with a predetermined minimum inter-vehicle distance.It is characterized by.
And claims8The invention according to claimAny one of 2-7In the preceding vehicle follow-up device described in the above, the target inter-vehicle distance setting means isSaidUntil the target inter-vehicle distance matches the inter-vehicle distance command value set by the inter-vehicle distance command value setting means,SaidThe target inter-vehicle distanceSaidIt is set using a function having a slow response characteristic.
[0009]
Claims9The invention according to claim2-8Either1 itemThe preceding vehicle follow-up device according to claim 1, further comprising a relative vehicle speed detection unit that detects a relative vehicle speed between the host vehicle and the preceding vehicle, wherein the target inter-vehicle distance setting unit is configured such that the relative vehicle speed detected by the relative vehicle speed detection unit is negative. UntilSaidThe target inter-vehicle distanceSaidIt is set using a function having a slow response characteristic.
[0010]
【The invention's effect】
Therefore, in the preceding vehicle follow-up control device which is the invention according to claim 1,,stopWhen the inter-vehicle distance is smaller than the inter-vehicle distance command value, the target inter-vehicle distance isSince the initial value is set to the inter-vehicle distance when the vehicle is stopped, the follow-up traveling with respect to the preceding vehicle starts immediately after the preceding vehicle starts, and the inter-vehicle distance from the preceding vehicle can be appropriately maintained.
The invention according to claim 2 sets the target inter-vehicle distance using a function having a slow response characteristic after the preceding vehicle has started.When starting the vehicle following the preceding vehicle, the target inter-vehicle distance is the same as or approximately the same as when the vehicle is stopped, and the braking / driving force is controlled so that the actual inter-vehicle distance matches the target inter-vehicle distance., AheadIt is possible to suppress and prevent the passenger from feeling uncomfortable that the host vehicle is left when the traveling vehicle starts.
[0011]
Claims3In the preceding vehicle follow-up control device according to the present invention,, MeetSlow functionNimuSince the function that expresses the time is included, the distance between vehicles at the time of stopping isSmallEven before, the preceding vehicleButStartYouRuWhen,The target inter-vehicle distance is the same as the inter-vehicle distance when stoppedAndThe own vehicle starts in the same manner as the preceding vehicle, and it is possible to effectively suppress and prevent the passenger from feeling uncomfortable that the own vehicle is left when the preceding vehicle starts.
[0012]
And claims4In the preceding vehicle follow-up control device according to the invention,, MuTimeStopSince it is set to be large according to the difference between the inter-vehicle distance and the inter-vehicle distance command value, if the difference between the inter-vehicle distance and the inter-vehicle distance command value is large, the dead time is set large., AheadEven after the departure of the traveling vehicle, it is possible to suppress and prevent the passenger from feeling uncomfortable that the host vehicle is left behind.
[0013]
Claims5In the preceding vehicle follow-up control device according to the invention,, MeetA function with a slow answer characteristic is a function in which the rate of change over time of the target inter-vehicle distance at the initial stage of start is negative.I didTherefore, the distance between vehicles at the time of stopping isSmallEven before, the preceding vehicleButStartThenThe target inter-vehicle distance is the inter-vehicle distance when stoppedSmallSetAndIt is possible to effectively suppress and prevent the host vehicle from starting at a higher acceleration than the preceding vehicle, and giving the passenger an uncomfortable feeling that the host vehicle is left when the preceding vehicle starts.
[0014]
And claims6In the preceding vehicle follow-up control device according to the invention,, DepartureTime change rate in early stageStopSince the vehicle distance is set to be large according to the size of the inter-vehicle distance, when the inter-vehicle distance is large and the risk of the host vehicle approaching the preceding vehicle is small, the host vehicle accelerates more quickly and starts. It is possible to effectively prevent and prevent the passenger from feeling uncomfortable that the host vehicle is left behind the preceding vehicle when the vehicle starts.
[0015]
Claims7In the preceding vehicle follow-up control device according to the invention,, MeetThe target inter-vehicle distance calculated by a function with a slow answer characteristic is regulated at a predetermined minimum inter-vehicle distance.I didTherefore, when the preceding vehicle starts, even if the host vehicle starts with a larger acceleration than the preceding vehicle, the preceding vehicle will not be closer than the minimum inter-vehicle distance,CrewIt is possible to effectively suppress and prevent the user from feeling uncomfortable.
[0016]
Claims8In the preceding vehicle follow-up control device according to the invention,,EyeSince the target inter-vehicle distance is set using a function with a slow response characteristic until the target inter-vehicle distance matches the inter-vehicle distance command value, for example, after the target inter-vehicle distance matches the inter-vehicle distance command value, the target inter-vehicle distance If a function having a fast response characteristic is used as the function used for setting the vehicle, it is possible to ensure the followability of the host vehicle with respect to the acceleration / deceleration of the preceding vehicle.
[0017]
And claims9In the preceding vehicle follow-up control device according to the invention, the target inter-vehicle distance is set using a function having a slow response characteristic until the relative vehicle speed between the host vehicle and the preceding vehicle becomes negative. Even when the preceding vehicle decelerates, the host vehicle does not approach the preceding vehicle,CrewIt is possible to suppress and prevent the user from feeling uncomfortable.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a preceding vehicle following control device according to the present invention will be described below with reference to the drawings.. Figure1 is a schematic configuration diagram illustrating an embodiment of the present invention, in which 1FL and 1FR are front wheels as driven wheels, and 1RL and 1RR are rear wheels as drive wheels.is there. Out of theseThe rear wheels 1RL and 1RR are rotationally driven by the driving force of the engine 2 being transmitted through the automatic transmission 3, the propeller shaft 4, the final reduction gear 5, and the axle 6.
[0019]
Also,The front wheels 1FL, 1FR and the rear wheels 1RL, 1RR are each provided with a disc brake 7 as a brake actuator that generates a braking force.AndBraking hydraulic pressure of these disc brakes 7IsIt is controlled by the braking control device 8. Here, the braking control device 8 is configured to control the brake pedal 8a.Depression amount andFrom the follow-up control controller 20 to be described laterBraking hydraulic pressure command valueConfigured to generate braking hydraulic pressure according toBe.
[0020]
Further, the engine 2 is provided with an engine output control device 9 that controls its output. The engine output control device 9 controls a throttle actuator 10 that adjusts a throttle opening provided in the engine 2 in accordance with a depression amount of an accelerator pedal 9a and a throttle opening command value from a follow-up control controller 20 described later. Configured to do.
[0021]
Further, the automatic transmission 3 is provided with a transmission control device 11 that controls the shift position and the working fluid pressure suitable for the shift position. The transmission control device 11 is configured to control a shift position and a working fluid pressure of the automatic transmission 3 in accordance with a depression amount of the accelerator pedal 9a and a shift command value from a follow-up control controller 20 described later. .
[0022]
On the other hand, an inter-vehicle distance sensor 12 having a radar-type configuration that sweeps laser light and receives reflected light from a preceding vehicle is provided at the lower part of the vehicle body on the front side of the vehicle. The inter-vehicle distance sensor 12 measures the time from when the laser light is swept until the reflected light of the preceding vehicle is received, and detects the inter-vehicle distance L between the host vehicle and the preceding vehicle.. AndThen, the detected value of the inter-vehicle distance L is differentiated to calculate the relative speed ΔV between the host vehicle and the preceding vehicle, and these are output to the follow-up control controller 20.TheAs a method for calculating the relative speed ΔV from the inter-vehicle distance L, for example, a band-pass filter may be used instead of the method of differentiating the detected value of the inter-vehicle distance L. The inter-vehicle distance sensor 12 isBetween your vehicle and the preceding vehicleAny device that can detect the inter-vehicle distance L can be used.GenerationAlternatively, the inter-vehicle distance L or the like may be detected using radio waves or ultrasonic waves.
[0023]
Also, the vehicle,A vehicle speed sensor 13 that detects the host vehicle speed V based on the rotational speed of the lopeller shaft 4 is provided.ProvidedYes. The inter-vehicle distance L and the relative speed ΔV output from the inter-vehicle distance sensor 12 and the own vehicle speed V output from the vehicle speed sensor 13 are input to the follow-up control controller 20. The follow-up control controller 20 is constituted by a discretized digital system such as a microcomputer (not shown), and executes a follow-up control process to be described later. When the preceding vehicle is captured, the inter-vehicle distance L is set as the target inter-vehicle distance L.^*To controlBraking hydraulic pressure command value,Throttle opening command valueAnd the shift command value are output to the braking control device 8, the engine output control device 9, and the transmission control device 11.
[0024]
The follow-up control process in the present embodiment constitutes a control block shown in FIG. 2 in the form of a microcomputer software. This control block includes an inter-vehicle distance command value calculation unit 31, a follow-up control mode selection unit 32, a target An inter-vehicle distance calculation constant determination unit 33, a target inter-vehicle distance calculation unit 34, and a vehicle speed command value calculation unit 35 are provided. The inter-vehicle distance command value calculation unit 31 is based on the relative speed ΔV detected by the inter-vehicle distance sensor 12 and the own vehicle speed V detected by the vehicle speed sensor 13.^*Vehicle speed V of the preceding vehicle_t(= V + ΔV) is calculated according to the following equation (1), and the calculation result is output to the follow-up control mode selection unit 32, the target inter-vehicle distance calculation constant determination unit 33, and the target inter-vehicle distance calculation unit 34. Do.
[0025]
L^*= A ・ V_t +L_of= A ・ (V + △ V)+L_of ……… (1)
Where a is a coefficientAnd, L_ofIs an offset value.
The inter-vehicle distance command value L^*Is not limited to the above equation (1). For example, it may be calculated in accordance with the following equation (2) as a function of the vehicle speed V. You may make it set to.
[0026]
L^*= A '· V+L_of ……… (2)
However, a 'is a coefficient.
Further, the follow-up control mode selection unit 32 is calculated by the inter-vehicle distance L and the relative speed ΔV detected by the inter-vehicle distance sensor 12, the own vehicle speed V detected by the vehicle speed sensor 13, and the inter-vehicle distance command value calculation unit 31. Inter-vehicle distance command value L^*, And the target inter-vehicle distance L calculated by the target inter-vehicle distance calculation unit 34_T3 types of follow-up control modes based on(Follow-up control mode 0, follow-up control mode 1 and follow-up control mode 2)Select the one according to the following situationAndThe selection result is output to the target inter-vehicle distance calculation unit 34.
[0027]
On the other hand, the target inter-vehicle distance calculation constant determination unit 33 calculates the inter-vehicle distance command value L calculated by the inter-vehicle distance command value calculation unit 31.^*In the inter-vehicle distance control system that outputs the inter-vehicle distance L detected by the inter-vehicle distance sensor 12, the actual inter-vehicle distance L is the inter-vehicle distance command value L.^*In order to make the response characteristic of the inter-vehicle distance control system to reach the desired value, the inter-vehicle distance deviation ΔL (= L−L^*) And relative speed ΔVDamping coefficient ζ of inter-vehicle distance control system _T And natural frequency ω _T The setPerform the process.
[0028]
Specifically, the damping coefficient ζ of the inter-vehicle distance control system according to the inter-vehicle distance deviation ΔL and the relative speed ΔV so that a favorable response characteristic can be obtained in various following situations._TAnd the natural frequency ω_TAre set in advance as a map, and at the time of follow-up control, the damping coefficient ζ corresponding to the inter-vehicle distance deviation ΔL and the relative speed ΔV is calculated from the map._TAnd natural frequency ω_TIs read out. Table 1 shows the damping coefficient ζ_TTable 2 shows the natural frequency ω_TAn example of the map is shown.
[0029]
[Table 1]

[0030]
[Table 2]

[0031]
The target inter-vehicle distance calculation unit 34 is a filter associated with the follow-up control mode selected by the follow-up control mode selection unit 32, and is an attenuation coefficient ζ determined by the target inter-vehicle distance calculation constant determining unit 33._TAnd natural frequency ω_TThe vehicle distance command value L calculated by the vehicle distance command value calculation unit 31 is used with the coefficient set in.^*And inter-vehicle distance L set when the preceding vehicle is supplemented_oAnd the target inter-vehicle distance L_TAnd target relative speed △ V_TAnd processing for outputting those calculation results to the vehicle speed command value calculation unit 35 is performed. The follow-up control mode 0 corresponds to a low-pass filter with a second-order lag type, the follow-up control mode 1 corresponds to a low-pass filter with a second-order lag type including a dead time, and the follow-up control mode 2 is a non-minimum. Corresponds to the inverse response fill expressed by the transfer function of the phase system.
[0032]
Further, the vehicle speed command value calculation unit 35 is configured to output the target inter-vehicle distance L calculated by the target inter-vehicle distance calculation unit 34._TAnd target relative speed △ V_TBased on the vehicle speed command value V^*Is calculated according to the following expression (3), and the calculation result is output to the vehicle speed control unit 36.
V^*= V (t) + ΔV (t)-[f_V{△ V_T(T)−ΔV (t)} + f_L{L_T(T)−L (t)}] ……… (3)
Where f_VAnd f_LIs a constant.
[0033]
The vehicle speed control unit 36 then calculates the vehicle speed command value V calculated by the vehicle speed command value calculation unit 35.^*The throttle opening command value, the brake hydraulic pressure command value, and the shift command value for making the vehicle speed V coincide with each other are calculated and output to the engine output control device 9, the brake control device 8, and the transmission control device 11. Vehicle speed command value V^*As a calculation method for making the vehicle speed V coincide with each other, various control methods such as a feedback control method and a robust model matching control method described in Japanese Patent Laid-Open No. 2000-135934 can be used.
[0034]
Next, the tracking control mode selection unit 32 in FIG.Be calledThe process will be described in detail based on the flowchart of FIG.. ThisWhen the process is executed,FirstIn step S1, follow-up control mode 0 is selected.WasWhether the follow-up control mode 0 is selectedWasSometimes (Yes), the process proceeds to step S2, and otherwise (No), the process proceeds to step S8. In the initial state, the tracking control mode 0 is selected as the type of the tracking control mode.HadShall.
[0035]
In Step S2, it is determined whether or not the vehicle speed V of the host vehicle detected by the vehicle speed sensor 13 is “0”. If it is “0” (Yes), the process proceeds to Step S3, and if not (No). This process ends.
In step S3, it is determined whether or not the relative speed ΔV detected by the inter-vehicle distance sensor 12 is “0”. If it is “0” (Yes), the process proceeds to step S4, and if not (No). This process ends.
[0036]
In step S4, the inter-vehicle distance L when the vehicle is stopped detected by the inter-vehicle distance sensor 12._oIs the inter-vehicle distance command value L calculated by the inter-vehicle distance command value calculating unit 31._o ^*Less than (L_o<L_o ^*), If not (Yes), the process proceeds to step S5. Otherwise (No), this process is terminated.
In step S5, the inter-vehicle distance L when the vehicle is stopped detected by the inter-vehicle distance sensor 12._oIs the predetermined minimum distance L_minLess than (L_o<L_min), If not (Yes), the process proceeds to step S6. Otherwise (No), the process proceeds to step S7.
[0037]
In step S6, the tracking control mode 1 is selected as the type of the tracking control mode, and then this process ends.
In step S7, the tracking control mode 2 is selected as the type of the tracking control mode, and then this process ends.
On the other hand, in step S8, the vehicle speed V of the preceding vehicle is determined based on the relative speed ΔV detected by the inter-vehicle distance sensor 12 and the own vehicle speed V detected by the vehicle speed sensor 13._tIs calculated to determine whether the preceding vehicle is decelerating. When the vehicle is decelerating (Yes), the process proceeds to step S10. When not (No), the process proceeds to step S9.
[0038]
In step S9, the inter-vehicle distance command value L calculated by the inter-vehicle distance command value calculating unit 31.^*And the target inter-vehicle distance L calculated by the target inter-vehicle distance calculation unit 34_TAre matched, and if they are coincident (Yes), the process proceeds to step S10, and if not (No), this process is terminated.
In step S10, the tracking control mode 0 is selected as the type of the tracking control mode, and this process is terminated.
[0039]
Next, in the target inter-vehicle distance calculation unit 34 in FIG.DoneThe process will be described in detail based on the block diagram of FIG. This process constitutes a control block shown in FIG. 4, and the control block includes an inter-vehicle distance command value L^*And damping coefficient ζ_TAnd natural frequency ω_TBased on the above, the target inter-vehicle distance L in the low-pass fill including dead time_TAThe target inter-vehicle distance calculation unit A341 for calculating the target inter-vehicle distance L in the non-minimum phase inverse response filter_TBThe target inter-vehicle distance calculation unit B342 for calculating the target inter-vehicle distance L with a low-pass filter_TCA target inter-vehicle distance calculation unit C343 for calculatingBased on the selection result by the tracking control mode selection unit 32,The target inter-vehicle distance L calculated by the target inter-vehicle distance calculation units 341, 342, 343_TAL_TBL_TCofEitherTarget inter-vehicle distance L_TA tracking control mode switching unit 344 that outputs to the vehicle speed control unit 36 and the like.
[0040]
Out of theseThe target inter-vehicle distance calculation unit A341 is an inter-vehicle distance command value L calculated by the inter-vehicle distance command value calculation unit 31.^*The damping coefficient ζ determined by the target inter-vehicle distance calculation constant determining unit 33 based on_TAnd natural frequency ω_TAccording to the following equation (4) including a time delay element in a low-pass filter of the second-order lag type havingEyesDistance between standard vehicles L_TA as well asTarget relative speed △ V_TAAnd the calculation result is output to the follow-up control mode switching unit 344. In the following formula (4),Inter-vehicle distance sensor 12Inter-vehicle distance L at stop detected at_oAnd relative speed ΔV_o EyesDistance between standard vehicles L_TAAnd target relative speed ΔV_TAThe initial value of.
[0041]
[Expression 1]

[0042]
Further, when the above formula (4) is Laplace transformed, it is expressed as the following formula (5).
[0043]
[Expression 2]

[0044]
The above equation (5) is the inter-vehicle distance command value L^*Is the target distance between vehicles L_TAIs an output function, and has a dead time element, and therefore, as shown in FIG._oLarger inter-vehicle distance command value L^*Is enteredAfter, Target inter-vehicle distance L_TAAs the distance L_oIs output over the dead time T.In addition,The dead time T of the target inter-vehicle distance calculation unit A341 is a dead time map as shown in FIG.According toAs shown in FIG. 7, the inter-vehicle distance command value L^*Depending on the magnitude of the deviation rate βSetTo do.Also,The deviation rate β is an inter-vehicle distance command value L when the host vehicle stops._o ^*And inter-vehicle distance L_oBased onTheFollowing (6) formulaAccording toCalculate.
[0045]
β = (L_o ^*-L_o) / L_o ^*× 100 ……… (6)
However, L_o ^*> L_oIt is.
Note that the method for obtaining the dead time T is not limited to the method using the deviation rate β, and for example, the inter-vehicle distance L when the vehicle is stopped._oEtc. as a parameter, a map of the dead time T that coincides with the occupant's feeling is created in advance through experiments and the like._oYou may make it ask directly.
[0046]
In addition, the target inter-vehicle distance calculation unit B 342 is an inter-vehicle distance command value L calculated by the inter-vehicle distance command value calculation unit 31.^*The damping coefficient ζ determined by the target inter-vehicle distance calculation constant determining unit 33 based on_TAnd natural frequency ω_TA low-pass filter of non-minimum phase system having a predetermined minimum inter-vehicle distance L_minAnd a limiter limited byIn particular,The low-pass filter is7) Target inter-vehicle distance L according to equation_TBAnd target relative speed ΔV_TBThe limiter limits the calculation result and outputs the result to the follow-up control mode switching unit 344. The following (7)Inter-vehicle distance sensor 12Inter-vehicle distance L at stop detected at_oAnd relative speed ΔV_oThe target inter-vehicle distance L_TBAnd target relative speed ΔV_TBThe initial value of.
[0047]
[Equation 3]

[0048]
In addition, (7) To Laplace transform8)
[0049]
[Expression 4]

[0050]
the above(8) Is the vehicle distance command value L^*Is the target distance between vehicles L_TBIs a non-minimum phase system having a positive zero “1 / α”, and as shown in FIG._oLarger inter-vehicle distance command value L^*Is enteredWhen, Target inter-vehicle distance L_TBThe response of the reverse shake is calculated by calculating once and then gradually increasing it. At that time, the minimum distance L_minTarget distance L_TBTherefore, the target inter-vehicle distance L_TBOutput to the follow-up control mode switching unit 344 even if calculated to be smallBe doneTarget inter-vehicle distance L_TBIs the minimum distance L_minShorterturn intoThere is nothing.
[0051]
Note that the coefficient α of the reverse response fill of the target inter-vehicle distance calculation unit B342 is a map as shown in FIG.According toAs shown in FIG. 10, the inter-vehicle distance L when the vehicle is stopped_oAnd minimum distance L_minThe difference in distance between vehicles is △ L _{om in}Set larger according to the size of the. In addition, the method for obtaining the coefficient α is the inter-vehicle distance deviation ΔL. _{om in}For example, the distance L between the vehicles at the time of stopping_oAs a parameter, a map of coefficient α that matches the occupant's feeling is created in advance through experiments and the like, and the inter-vehicle distance L_oYou may make it ask directly.
[0052]
On the other hand, the target inter-vehicle distance calculation unit C343 is provided with the inter-vehicle distance command value L calculated by the inter-vehicle distance command value calculation unit 31.^*The damping coefficient ζ determined by the target inter-vehicle distance calculation constant determining unit 33 based on_TAnd natural frequency ω_TRepresents a low-pass filter of the second-order lag type having9Follow the formulaEyesDistance between standard vehicles L_TcAnd target relative speed ΔV_TcAnd the calculation result is output to the follow-up control mode switching unit 344. The following (9In the formula), the preceding vehicle was captured.Sometimes captureImmediately following distance L_oAnd relative speed ΔV_oThe target inter-vehicle distance L_TcAnd target relative speed ΔV_TcAs the initial value ofAlso,When the tracking control mode 1 or the tracking control mode 2 is switched to the tracking control mode 0, the inter-vehicle distance L and the relative speed ΔV immediately after the switching are set as initial values.
[0053]
[Equation 5]

[0054]
In addition, (9) To Laplace transform10)
[0055]
[Formula 6]

[0056]
the above(10) Is the vehicle distance command value L^*Enter andEyesDistance between standard vehicles L_TA, And a second order lag element, the actual inter-vehicle distance L as shown in FIG._oLarger inter-vehicle distance command value L^*Is enteredWhen, Target inter-vehicle distance L_TBAs a result, a large value is output gradually from the initial value.
Then, the follow-up control mode switching unit 344Selects the target inter-vehicle distance calculation units 341, 342, and 343 corresponding to the selected follow-up control mode based on the selection result in the follow-up control mode selection unit 32, and the target inter-vehicle distance calculation units 341, 342, Target inter-vehicle distance L output by 343_TAnd relative speed ΔV_TIs output to the vehicle speed command value calculator 35 and the follow-up control mode selector 32.In particular, Tracking control mode typesAsFollow-up control mode 0Was selectedSometimes, the target inter-vehicle distance L calculated by the target inter-vehicle distance calculation unit C343_TcAnd target relative speed ΔV_TcIs output.FollowSecondary control mode 1Was selectedSometimes, the target inter-vehicle distance L calculated by the target inter-vehicle distance calculation unit A341_TAAnd target relative speed ΔV_TAOutputAdd toSecondary control mode 2Is selectedThe target inter-vehicle distance L calculated by the target inter-vehicle distance calculation unit B342._TBAnd target relative speed ΔV_TBIs output.
[0057]
Next, the operation of the present embodiment will be described in detail based on a specific situation. First, traffic jams occur on the highwayAndWhen the own vehicle stops following the preceding vehicle, as shown in FIG.ButIn order to start following the preceding vehicle,CrewSuppose that an operation for starting follow-up control is performed. Then, the follow-up control process is executed by the follow-up control controller 20.AndAs shown in the block diagram of FIG. 2, first, the processing of the inter-vehicle distance command value calculation unit 31 is executed.AndBased on the relative speed ΔV detected by the inter-vehicle distance sensor 12 and the own vehicle speed V detected by the vehicle speed sensor 13.CarDistance command value L^*The calculation result is output to the follow-up control mode selection unit 32, the target inter-vehicle distance calculation constant determination unit 33, and the target inter-vehicle distance calculation unit 34.
[0058]
Next, the processing of the target inter-vehicle distance calculation constant determination unit 33 is executed.AndThe inter-vehicle distance L and the relative speed ΔV detected by the inter-vehicle distance sensor 12 and the inter-vehicle distance command value L calculated by the inter-vehicle distance command value calculation unit 31.^*Based on the above, the damping coefficient ζ of the inter-vehicle distance control system according to the inter-vehicle distance deviation ΔL and the relative speed ΔV_TAnd natural frequency ω_TIs determined. At the same time, the process of the tracking control mode selection unit 32 is also executed.AndFollow control mode type is set to follow control mode 0BeFor,As shown in the flowchart of FIG.The determination in step S1 is “Yes”, and the host vehicle has stopped following the preceding vehicle.ForThe determinations in steps S2 and S3 are also “Yes”.The AndThe degree of congestion is high and the distance L between vehicles when stopping_oIs the minimum distance L_minIf it is smaller, the determinations in steps S4 and S5 are also “Yes”, and the tracking control mode 1 is selected as the type of the tracking control mode in step S6.
[0059]
Then, the processing of the target inter-vehicle distance calculation unit 34 is executed, and as shown in the block diagram of FIG.^*And damping coefficient ζ_TAnd natural frequency ω_TBased on the above, the target inter-vehicle distance L is calculated by the target inter-vehicle distance calculation unit A341 having a low-pass filter including dead time._TAIs calculated, and the target inter-vehicle distance L is calculated by the target inter-vehicle distance calculation unit B342 having the reverse response fill._TBFurther, the target inter-vehicle distance L is calculated by the target inter-vehicle distance calculation unit C343 having a low-pass filter._TCIs calculated. Next, the target inter-vehicle distance L calculated by the target inter-vehicle distance calculation units 341, 342, and 343._TAL_TBL_TCThe target inter-vehicle distance L calculated by the target inter-vehicle distance calculation unit A341 associated with the follow-up control mode 1_TAHowever, as shown in FIG. 5, the target inter-vehicle distance L from the follow-up control mode switching unit 344_TIs output to the vehicle speed control unit 36 and the like.
[0060]
Also, the target inter-vehicle distance L_T ButIn the input vehicle speed command value calculation unit 35, the target inter-vehicle distance L_TVehicle speed command value V based on^*Is calculated, and the vehicle speed control unit 36 determines the vehicle speed command value V^*To match the vehicle speed V toBraking oil pressure command value,Throttle opening commandValueAnd shift command values are calculated and output to the braking control device 8, the engine output control device 9, and the transmission control device 11. Then, the engine output control device 9 or the like to which the throttle opening command value or the like has been input,^*The braking / driving force is controlled so that the actual inter-vehicle distance L coincides with the preceding vehicle, and the preceding vehicle starts.ThenThe inter-vehicle distance L between the host vehicle and the preceding vehicle becomes the same value as when the vehicle is stoppedSelfvehicleAlsoTake offFor, Preventing the passenger from feeling uncomfortable that the vehicle is left behindTo doit can.
[0061]
Further, the target inter-vehicle distance calculation unit A341 calculates the target inter-vehicle distance L._TAAs shown in FIG. 6, the dead time T is calculated as the inter-vehicle distance L when the vehicle is stopped._oAnd inter-vehicle distance command value L_o ^*For example, when the host vehicle stops following the preceding vehicle due to traffic congestion or the like, the actual inter-vehicle distance L and the inter-vehicle distance command value L are set._o ^*7 is large, the dead time T is set large as shown in FIG. 7. Therefore, even after the vehicle has started, the host vehicle has an inter-vehicle distance L_oIt is possible to suppress and prevent the passenger from feeling uncomfortable that the host vehicle is left when the preceding vehicle starts.
[0062]
On the other hand, the degree of congestion is low and the inter-vehicle distance L_oIs the minimum distance L_minThanbigAs shown in FIG. 3, when the process of the follow-up control mode selection unit 32 is executed, the determination in step S5 becomes “No” through steps S1 to S4, and in step S7, Following control mode 2 is selected as the type of tracking control mode. Then, in the target inter-vehicle distance calculation unit 34, as shown in the block diagram of FIG. 4, the target inter-vehicle distance L output from the three types of target inter-vehicle distance calculation units 341, 342, and 343._TAL_TBL_TCThe target inter-vehicle distance L calculated by the target inter-vehicle distance calculation unit B342 associated with the follow-up control mode 2_TBHowever, as shown in FIG._TIs output to the vehicle speed control unit 36 and the like.
[0063]
Then, the engine output control device 9 and the like to which the throttle opening command value has been input, the target inter-vehicle distance L_TThe braking / driving force is controlled so as to match the actual inter-vehicle distance L, and when the preceding vehicle starts, the inter-vehicle distance L between the host vehicle and the preceding vehicle becomes a value smaller than that when the vehicle stops. Since the host vehicle accelerates and starts larger than the preceding vehicle, it is possible to suppress and prevent the passenger from feeling uncomfortable that the host vehicle is left behind.
[0064]
Thus, in the present embodiment, the target inter-vehicle distance L at the initial stage of start._TBThe target inter-vehicle distance L is calculated using a function that makes the time change rate of_TTherefore, the host vehicle will start with a greater acceleration than the preceding vehicle, and it is possible to prevent the passenger from feeling uncomfortable that the host vehicle is left when the preceding vehicle starts. .
[0065]
Further, as shown in FIG. 9, the target inter-vehicle distance L_TThe coefficient α representing the time change rate ofSeparationL_oAnd minimum distance L_minInter-vehicle distance deviation ΔL representing the difference between _{om in}As shown in FIG. 10, when the inter-vehicle distance is large and the possibility that the host vehicle will approach the preceding vehicle is small, the host vehicle accelerates more greatly and starts. Therefore, it is possible to effectively suppress and prevent the passenger from feeling uncomfortable that the host vehicle is left behind.
[0066]
Also, the target inter-vehicle distance L calculated using the inverse response filter_TBThe minimum distance between vehicles L_minTherefore, when the preceding vehicle starts, even if the host vehicle starts at a higher acceleration than the preceding vehicle, the minimum distance L_minIt is possible to effectively suppress and prevent the driver from feeling uncomfortable.
The target inter-vehicle distance L calculated by the target inter-vehicle distance calculation unit 34 while accelerating the host vehicle by repeatedly executing the above flow._TIs the inter-vehicle distance command value L^*Suppose that Then, when the process of the follow-up control mode selection unit 32 is executed, as shown in the flowchart of FIG. 3, the determinations of steps S1 and S8 are “No”, and the determination of step S9 is “Yes”. In step S10, the tracking control mode 0 is selected as the type of the tracking control mode. Then, in the target inter-vehicle distance calculation unit 34, as shown in the block diagram of FIG. 4, the target inter-vehicle distance L output from the three types of target inter-vehicle distance calculation units 341, 342, and 343._TThe target inter-vehicle distance L calculated by the target inter-vehicle distance calculation unit C343 associated with the follow-up control mode 0_TCHowever, as shown in FIG. 11, the following inter-vehicle distance L from the follow-up control mode switching unit 344_TAs the target vehicle distance L_TIs output as
[0067]
Then, the engine output control device 9 and the like to which the throttle opening command value has been input, the target inter-vehicle distance L_TThe braking / driving force is controlled so that the actual inter-vehicle distance L coincides with the inter-vehicle distance L between the host vehicle and the preceding vehicle.^*For example, when the preceding vehicle accelerates, the own vehicle also accelerates with the same or a slight delay as the preceding vehicle, so that the following ability of the own vehicle can be ensured with respect to the acceleration / deceleration of the preceding vehicle. .
[0068]
On the other hand, the target inter-vehicle distance L calculated by the target inter-vehicle distance calculation unit 34 while accelerating the host vehicle by repeatedly executing the above flow._TIs the inter-vehicle distance command value L^*It is assumed that a traffic jam occurs again and the preceding vehicle decelerates before the vehicle matches. Then, when the process of the tracking control mode selection unit 32 is executed, as shown in the flowchart of FIG. 3, the determination of step S8 becomes “Yes” through step S1, and the type of the tracking control mode is determined in step S10. The tracking control mode 0 is selected as follows.
[0069]
Thus, in the present embodiment, when the preceding vehicle starts to decelerate, the target inter-vehicle distance L_TIs set using a function having a relatively fast response characteristic, the inter-vehicle distance L between the own vehicle and the preceding vehicle is immediately controlled to a value corresponding to the deceleration state of the preceding vehicle, and the own vehicle is It is possible to suppress and prevent the driver from feeling uncomfortable.
[0070]
In the above embodiment, the inter-vehicle distance sensor 12 corresponds to the inter-vehicle distance detection means and the relative vehicle speed detection means, the inter-vehicle distance command value calculation unit 31 corresponds to the inter-vehicle distance command value setting means, and the target inter-vehicle distance calculation unit. 34 corresponds to the target inter-vehicle distance setting means, and the vehicle speed command value calculation unit 35 and the vehicle speed control unit 36 correspond to the braking / driving force control device.
Moreover, the said embodiment showed an example of the preceding vehicle follow-up control apparatus of this invention, and does not limit the structure of an apparatus.
[0071]
In the above embodiment, the case where the present invention is applied to a rear wheel drive vehicle has been described. However, the present invention can also be applied to a front wheel drive vehicle, and the case where the engine 2 is applied as a rotational drive source will be described. However, the present invention is not limited to this, and an electric motor can be applied. Furthermore, the present invention can also be applied to a hybrid vehicle using an engine and an electric motor.
[0072]
Furthermore, in the above embodiment, the case where the laser radar is applied as the inter-vehicle distance sensor 12 has been described. However, the present invention is not limited to this, and a millimeter wave radar may be applied. You may make it calculate the distance between vehicles by image-processing the imaging of a camera.
Further, the case where the follow-up control controller 20 is configured by a discretized digital system such as a microcomputer has been described. However, the present invention is not limited to this, and electronic circuits such as a function generator, a comparator, and an arithmetic unit are used. You may make it comprise combining.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an embodiment of a preceding vehicle follow-up control device of the present invention.
FIG. 2 is a block diagram showing a specific configuration of a tracking process executed by the tracking control controller of FIG. 1;
FIG. 3 is a flowchart showing a specific example of processing of a follow-up control mode selection unit in FIG. 2;
4 is a block diagram showing a specific example of processing of a target inter-vehicle distance calculation unit in FIG. 2. FIG.
FIG. 5 is a graph showing a change over time in a target inter-vehicle distance calculated using a filter including a dead time element.
FIG. 6 is a characteristic diagram showing a map example of a dead time with respect to a deviation rate.
FIG. 7 is a graph showing a simulation result of a change in the target inter-vehicle distance with time, with the dead time changed.
FIG. 8 is a graph showing a change over time in a target inter-vehicle distance calculated using an inverse response filter.
FIG. 9 is a characteristic diagram showing an example of a map of coefficients with respect to the inter-vehicle distance deviation.
FIG. 10 is a graph showing a simulation result of a change over time in the target inter-vehicle distance, with the coefficient changed.
FIG. 11 is a graph showing a change over time in the target inter-vehicle distance calculated using a second-order lag type filter.
FIG. 12 is an explanatory diagram for explaining an operation state of the present embodiment.
[Explanation of symbols]
1FL, 1FR are front wheels
1RL, 1RR is the rear wheel
2 is the engine
3 is an automatic transmission
4 is the propeller shaft
5 is the final reduction gear
6 is the axle
9 is an engine output control device
10 is a throttle actuator
11 is a transmission control device.
12 is an inter-vehicle distance sensor
13 is a vehicle speed sensor
20 is a controller for tracking control

Claims (9)

Vehicle distance detecting means and the inter-vehicle distance command value setting means for setting a predetermined inter-vehicle distance command value, vehicle set in front Symbol inter-vehicle distance command value setting means for detecting an inter-vehicle distance between the preceding vehicle and the subject vehicle A target inter-vehicle distance setting means for setting a target inter-vehicle distance using a predetermined function based on a distance command value, and an inter-vehicle distance detected by the inter-vehicle distance detection means to a target inter-vehicle distance set by the target inter-vehicle distance setting means and a braking-driving force control means for controlling the longitudinal force as match,
The target inter-vehicle distance setting means includes an inter-vehicle distance command in which a stop-time inter-vehicle distance detected by the inter-vehicle distance detection means is set by the inter-vehicle distance command value setting means when the host vehicle and the preceding vehicle are stopped. When the preceding vehicle starts, the preceding vehicle slave control device starts setting the target inter-vehicle distance with the stop-time inter-vehicle distance as an initial value when the preceding vehicle starts. 2. The preceding vehicle slave control apparatus according to claim 1, wherein the target inter-vehicle distance setting means sets the target inter-vehicle distance using a function having a slow response characteristic after the preceding vehicle has started. The preceding vehicle follow-up control device according to claim 2 , wherein the function having a slow response characteristic includes a function representing a dead time. Preceding vehicle following control apparatus according to claim 3, characterized in that the dead time, setting greatly depending on the magnitude of the difference of the vehicle stop time vehicle distance and the inter-vehicle distance command value. The preceding vehicle follow-up control device according to claim 2 , wherein the function having a slow response characteristic is a function in which a time change rate of a target inter-vehicle distance at an initial stage of start is negative. Preceding vehicle following control apparatus according to claim 5, wherein the time rate of change of the vehicle distance early stage of the start, setting greatly according to the size of the distance between the stop time of the car. The target inter-vehicle distance setting means, preceding vehicle following according to any one of claims 2-6, characterized in that to regulate the target inter-vehicle distance calculated at a slow function of the response characteristic at a predetermined minimum distance between vehicles Control device. The target inter-vehicle distance setting means, until said target inter-vehicle distance is equal to the inter-vehicle distance command value set by the inter-vehicle distance command value setting means, the target inter-vehicle distance be set using a slow function of the response characteristic preceding vehicle slave control system in any one of claims 2-7, wherein. With a relative vehicle speed detecting means for detecting a relative speed between the preceding vehicle and the subject vehicle, the target inter-vehicle distance setting means, until the relative vehicle speed detected by said relative speed detecting means is negative, the said vehicle distance preceding vehicle slave control device according to any one of claims 2-8, characterized in that the set using the low response characteristic function.

Images