JP2005028986A - Attitude controller of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an attitude controller of a vehicle for certainly and accurately controlling the attitude of the vehicle by deriving an accurate steered angle of a steering wheel based on a steering wheel angle, even in a vehicle that is low in rigidity or has reduced rigidity in the rotation direction of the steering wheel. <P>SOLUTION: The controller 30 of the attitude controller of the vehicle calculates the steering wheel angle θ of the vehicle in the step 104, and derives the steered angle ξ of the steering wheel of the vehicle steered by a steering wheel operation of the vehicle in the steps 108 and 110 by correcting the steering wheel angle θ calculated in the step 104 based on the deviation between the steering wheel angle due to low rigidity in the rotation direction of the steering wheel of the vehicle and the steered angle of the steering wheel (a first map or second map). In the steps 116 and 118, the attitude of the vehicle is controlled based on the steered angle ξ of the steering wheel derived in the steps 108 and 110. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

なお、上記数３にて、Ａはスタビリティファクタであり、Ｌは車両Ｍのホイールベースである。
【００４８】
そして、制御装置３０は、目標ヨーレートＴωの算出が完了すると、ステップ１１４〜１２０の処理により車両Ｍの姿勢を制御する（第１の姿勢制御手段）。制御装置３０は、ステップ１１４において、ステップ１０６にて検出された実ヨーレートＲωとステップ１１２にて算出された目標ヨーレートＴωとの差分値であるヨーレート差Δωを算出する（ヨーレート差算出手段）。そして、ステップ１１６において、算出されたヨーレート差Δωの絶対値｜Δω｜が所定値Ｔｈ０以上であれば、車両Ｍは安定した状態にないので、プログラムをステップ１１８に進めて、車両Ｍの姿勢制御を実施する（第２の姿勢制御手段）。
【００４９】
制御装置３０は、ステップ１１８において、ブレーキ制御装置２４に指令を送り、各車輪Ｗｆｌ，Ｗｆｒ，Ｗｒｌ，Ｗｒｒに付与する制動力を制御して、車両Ｍの姿勢を安定な状態となるように制御する。すなわち、制御装置３０は、各車輪Ｗｆｌ，Ｗｆｒ，Ｗｒｌ，Ｗｒｒの制動力または／およびエンジン１０の出力を制御することにより、車両Ｍのヨーイング方向または／およびローリング方向の姿勢を制御する。例えば、車両Ｍがアンダーステアの状態にある場合には、内側の車輪に制動力を付与して車両Ｍに内向きモーメントを発生させ、オーバーステアの状態にある場合には、外側の車輪に制動力を付与して車両Ｍに外向きモーメントを発生させる。また、制御装置３０は、エンジン制御装置４０に指令を送り、エンジン１０のスロットルの開度を制御し出力トルクを制御して、車両Ｍの姿勢を安定な状態となるように制御する。例えば、車両Ｍがアンダーステアの状態にある場合にはスロットルを閉じ出力トルクを抑える。その後、プログラムをステップ１２２に進めて一旦終了する。
【００５０】
一方、ステップ１１６において、ヨーレート差Δωの絶対値｜Δω｜が所定値Ｔｈ０未満であれば、車両Ｍは安定した状態にあるので、プログラムをステップ１２０に進めて、上述した車両Ｍの姿勢制御を実施しない。その後、プログラムをステップ１２２に進めて一旦終了する。
【００５１】
上述したように、上記第１の実施の形態によれば、ステップ１０８，１１０にて、車両Ｍのハンドル１５の操作により操舵される車両Ｍの操舵輪の切れ角ξを、ステップ１０４にて算出されたハンドル角度θを車両Ｍのハンドル１５の回転方向の低剛性によるハンドル角度θと操舵輪の切れ角ξとの偏差に基づいて補正して導出し、ステップ１１２にて、ステップ１０８，１１０によって導出された操舵輪の切れ角ξに基づいて車両Ｍの目標ヨーレートＴωを算出し、ステップ１１４にて、ステップ１０６によって検出された実際のヨーレート（実ヨーレートＲω）とステップ１１２によって算出された目標ヨーレートＴωとを減算してヨーレート差Δωを算出し、ステップ１１６，１１８にてステップ１１４によって算出されたヨーレート差Δωに基づいて車両の姿勢を制御する。したがって、ハンドル１５の回転方向の剛性が低い車両、剛性が低下した車両において、ハンドル角度θの増加と実際の操舵輪の切れ角ξとの増加との間に偏差が生じる場合であっても、正確な目標ヨーレートＴωひいてはヨーレート差Δωをハンドル角度θより導出して、確実かつ正確な車両の姿勢制御を行うことができる。
【００５２】
また、上記第１の実施の形態によれば、ステップ１０８にて、ハンドル角度θを同ハンドル角度θと操舵輪の切れ角ξとの偏差に基づいて補正するための第１マップ（または第１演算式）に基づいて補正して補正ハンドル角度θａを導出し、ステップ１１０にて、ステップ１０８によって導出された補正ハンドル角度θａから操舵輪の切れ角ξを導出する。したがって、正確な操舵輪の切れ角ξをハンドル角度θより導出することができる。
【００５３】
また、上記第１の実施の形態によれば、第１マップ（または第１演算式）は車両Ｍのハンドル角度θと操舵輪の実際の切れ角ξとの偏差を打ち消すように構成されているので、ステップ１０４によって算出されたハンドル角度θを第１マップ（または第１演算式）に基づいて正確かつ確実に補正した補正ハンドル角度θａを導出することができる。
【００５４】
また、上記第１の実施の形態によれば、制御装置３０は、ハンドル角度θと操舵輪の切れ角ξとの間で生じる車両毎の偏差に適した第１マップ（または第１演算式）を予め備え、ステップ１０８，１１０にて第１マップ（または第１演算式）に基づいて操舵輪の切れ角ξを導出する。したがって、各車両の偏差が予めわかっていれば、より簡単な構成によって正確に操舵輪の切れ角ξを導出することができる。
【００５５】
また、上記第１の実施の形態によれば、制御装置３０は、各車輪Ｗｆｌ，Ｗｆｒ，Ｗｒｌ，Ｗｒｒの制動力または／およびエンジン１０の出力を制御することにより、車両Ｍのヨーイング方向または／およびローリング方向の姿勢を制御するので、車両Ｍのヨーイング方向または／およびローリング方向の姿勢の制御を正確かつ確実に行うことができる。
【００５６】
ｂ）第２の実施の形態
なお、上記第１の実施の形態においては、車両の姿勢制御装置は、ハンドル角度θを偏差に基づいて補正するための第１マップまたは第１演算式を記憶し、制御装置３０は、ステップ１０８にて、第１マップまたは第１演算式に基づいてハンドル角度θを補正して補正ハンドル角度θａを導出し、ステップ１１０にて、この導出された補正ハンドル角度θａから操舵輪の切れ角ξを導出したが、これに代えて、車両の姿勢制御装置は、ハンドル角度θと操舵輪の切れ角ξとの関係を示す第２マップまたは第２演算式を記憶し、制御装置３０は、ハンドル角度θを第２マップまたは第２演算式に基づいて補正して操舵輪の切れ角ξを導出するようにしてもよい。
【００５７】
第２マップは、ハンドル角度θを、ハンドル１５の回転方向の低剛性によるハンドル角度θと操舵輪の切れ角ξとの偏差に基づいて補正するためのものであり、図４に示すように、遊びまたはガタツキによるハンドル１５の遊び量θｂを考慮して、前記ハンドル角度θと操舵角の切れ角ξとの関係を示している。さらに、第２マップは、車両Ｍのハンドル角度θと操舵輪の実際の切れ角ξとの偏差を打ち消すように構成されている。
【００５８】
この第２マップは第１マップと同様に次のように作成される。まず車両Ｍのハンドル１５の遊び量θｂ（上記偏差）を測定する。そして、特にハンドル角度θの中立点付近にて偏差の影響を防止するため、中立点付近においては所定範囲の操舵輪の切れ角ξは０°となるように、それ以外の範囲はハンドル角度θに対してリニアに変化するように作成する。すなわち、ハンドル角度θが−θｂ≦θ≦＋θｂの範囲にある場合には、切れ角ξは０°となるように、ハンドル角度θがθ＜−θｂの範囲にある場合には、切れ角ξはξ＝ξ１＋ｃ４・θとなるように、ハンドル角度θがθｂ＜θの範囲にある場合には、切れ角ξはθａ＝−ξ２＋ｃ５・θとなるように作成される。なお、ｃ４，ｃ５はハンドル角度θに対する切れ角ξの比例定数である。
【００５９】
このように作成された第２マップは、ハンドル角度θと操舵輪の切れ角ξとの間で生じる車両毎の偏差、すなわちハンドル１５の遊び量θｂに適したものであり、車両毎に予め測定された偏差に対応するものが制御装置３０に記憶されている。なお、第２マップの代わりに第２演算式を用いるようにしてもよい。第２演算式は第２マップに基づいて導出されるものである。
【００６０】
上述した第２マップまたは第２演算式に基づいて補正して操舵輪の切れ角ξを導出する場合には、上述したステップ１０８，１１０の処理の代わりに、図５に示すステップ１３０の処理を実行すればよい。制御装置３０は、ステップ１３０において、上述したステップ１０４にて算出されたハンドル角度θから第２マップ（または第２演算式）に基づいて操舵輪の切れ角ξを導出する（操舵輪切れ角導出手段）。具体的には、ハンドル角度θが−θｂ≦θ≦＋θｂの範囲にある場合には、切れ角ξは０°となり、ハンドル角度θがθ＜−θｂの範囲にある場合には、切れ角ξはξ＝ξ１＋ｃ４・θとなり、ハンドル角度θがθｂ＜θの範囲にある場合には、切れ角ξはθａ＝−ξ２＋ｃ５・θとなる。
【００６１】
このような第２の実施の形態によれば、第１の実施の形態による作用・効果に加えて、制御装置３０は、ステップ１３０にて、ステップ１０４によって算出されたハンドル角度θを第２マップまたは第２演算式に基づいて補正して操舵輪の切れ角ξを導出するので、簡単かつ正確に操舵輪の切れ角ξをハンドル角度θより導出することができる。
【００６２】
また、上記第２の実施の形態によれば、第２マップ（または第２演算式）は車両Ｍのハンドル角度θと操舵輪の実際の切れ角ξとの偏差を打ち消すように構成されているので、ステップ１０４によって算出されたハンドル角度θを第２マップ（または第２演算式）に基づいて正確かつ確実に補正した操舵輪の切れ角ξを導出することができる。
【００６３】
また、上記第２の実施の形態によれば、制御装置３０は、ハンドル角度θと操舵輪の切れ角ξとの間で生じる車両毎の偏差に適した第２マップ（または第２演算式）を予め備え、ステップ１３０にて第２マップ（または第２演算式）に基づいて操舵輪の切れ角ξを導出する。したがって、各車両の偏差が予めわかっていれば、より簡単な構成によって正確に操舵輪の切れ角ξを導出することができる。
【００６４】
ｃ）第１の変形例
また、上述した各実施の形態において、第１マップ（または第１演算式）および第２マップ（または第２演算式）は、車両Ｍのハンドル１５の回転方向に対するヒステリシスを含むようにしてもよい。この場合、第１マップ（第２マップ）は、図６に示すように、交点Ｘ１（θｂ，０）からスタートし分岐点Ｘ２（θ１，θ２）を通過する経路Ｋ１と、逆方向から戻ってきて分岐点Ｘ２（θ１，θ２）を通過して交点Ｘ３（−θｂ，０）に到達する経路Ｋ３と、交点Ｘ３（−θｂ，０）からスタートし分岐点Ｘ４（−θ１，−θ２）を通過する経路Ｋ２と、逆方向から戻ってきて分岐点Ｘ４（−θ１，−θ２）を通過して交点Ｘ１（θｂ，０）に到達する経路Ｋ４から構成されている。すなわち、経路Ｋ１をハンドル１５の右回転への切り込みに対応した経路とすると、経路Ｋ３は左回転への切り戻しに対応した経路であり、経路Ｋ２は左回転への切り込みに対応した経路であり、経路Ｋ４は右回転への切り戻しに対応した経路である。なお、θｂはハンドル１５の遊び量である。
【００６５】
この場合、制御装置３０は、ステップ１０８にて、ハンドル角度θを図６に示す第１マップに基づいて補正して補正ハンドル角度θａを導出する（補正ハンドル角度導出手段）。具体的には、ハンドル角度θの絶対値｜θ｜が所定値θ１未満である場合にハンドル１５が切り込まれると、経路Ｋ１，Ｋ２に準じて補正されてハンドル角度θａが導出され、ハンドル角度θの絶対値｜θ｜が所定値θ１以上である場合にハンドル１５が切り戻されると、経路Ｋ３，Ｋ４に準じて補正されてハンドル角度θａが導出される。また、制御装置３０は、ステップ１３０にて、ハンドル角度θを図６に示す第２マップに基づいて補正して操舵輪の切れ角ξを導出する（操舵輪切れ角導出手段）。具体的には、ハンドル角度θの絶対値｜θ｜が所定値θ１未満である場合にハンドル１５が切り込まれると、経路Ｋ１，Ｋ２に準じて補正されて操舵輪の切れ角ξが導出され、ハンドル角度θの絶対値｜θ｜が所定値θ１以上である場合にハンドル１５が切り戻されると、経路Ｋ３，Ｋ４に準じて補正されて操舵輪の切れ角ξが導出される。
【００６６】
この変形例によれば、ハンドル１５を切り込む場合と切り戻す場合のいずれの場合にも、的確にハンドル角度θを補正ハンドル角度θａに補正することができ、また、的確にハンドル角度θに対応する操舵輪の切れ角ξを導出することができる。
【００６７】
また、第１マップ（第２マップ）は、図７に示すように、原点Ｘ０（０，０）からスタートし分岐点Ｘ２（θ１，θ２）を通過する経路Ｋ１と、逆方向から戻ってきて分岐点Ｘ２（θ１，θ２）を通過して原点Ｘ０（０，０）に回帰する経路Ｋ３と、原点Ｘ０（０，０）からスタートし分岐点Ｘ４（−θ１，−θ２）を通過する経路Ｋ２と、逆方向から戻ってきて分岐点Ｘ４（−θ１，−θ２）を通過してＸ０（０，０）に回帰する経路Ｋ４から構成されている。すなわち、経路Ｋ１をハンドル１５の右回転への切り込みに対応した経路とすると、経路Ｋ３は左回転への切り戻しに対応した経路であり、経路Ｋ２は左回転への切り込みに対応した経路であり、経路Ｋ４は右回転への切り戻しに対応した経路である。
【００６８】
この場合、制御装置３０は、ステップ１０８にて、ハンドル角度θを図７に示す第１マップに基づいて補正して補正ハンドル角度θａを導出する（補正ハンドル角度導出手段）。具体的には、ハンドル角度θの絶対値｜θ｜が所定値θ１未満である場合にハンドル１５が切り込まれると、経路Ｋ１，Ｋ２に準じて補正されてハンドル角度θａが導出され、ハンドル角度θの絶対値｜θ｜が所定値θ１以上である場合にハンドル１５が切り戻されると、経路Ｋ３，Ｋ４に準じて補正されてハンドル角度θａが導出される。また、制御装置３０は、ステップ１３０にて、ハンドル角度θを図７に示す第２マップに基づいて補正して操舵輪の切れ角ξを導出する（操舵輪切れ角導出手段）。具体的には、ハンドル角度θの絶対値｜θ｜が所定値θ１未満である場合にハンドル１５が切り込まれると、経路Ｋ１，Ｋ２に準じて補正されて操舵輪の切れ角ξが導出され、ハンドル角度θの絶対値｜θ｜が所定値θ１以上である場合にハンドル１５が切り戻されると、経路Ｋ３，Ｋ４に準じて補正されて操舵輪の切れ角ξが導出される。
【００６９】
次に、この変形例を車両に適用した場合の補正された操舵角の切れ角ξから計算した車両のヨーレートと実ヨーレートとを比較することにより、ハンドルの遊び量の補正の有用性を検証する。テスト走行中の両ヨーレートの一部を図８に示す。この図から明らかなように、補正された操舵角の切れ角ξから計算した車両のヨーレートは概ね実ヨーレートと近い値となっており、上述した補正の有用性が確認できる。
【００７０】
この変形例によれば、ハンドル１５を切り込む場合と切り戻す場合のいずれの場合にも、的確にハンドル角度θを補正ハンドル角度θａに補正することができ、また、的確にハンドル角度θに対応する操舵輪の切れ角ξを導出することができることに加えて、さらに、補正ハンドル角度θａ（または操舵輪切れ角ξ）は不連続に変化しないで、連続に変化するので、中立点付近のハンドル操作性に違和感を付与することがないため操舵感が向上される。
【００７１】
ｄ）第２の変形例
また、上記各実施の形態、および変形例において、互いに異なる複数の偏差に対応した第１マップ（または第１演算式）を制御装置３０に記憶し、偏差の有無および程度を検出し、検出された偏差に適した第１マップ（または第１演算式）を選択し、その選択された第１マップ（または第１演算式）に基づいて操舵輪の切れ角を導出するようにしてもよい。なお、この処理は、車両の走行開始後、上述した図２に示すフローチャートとは別に実施してもよいし、同フローチャートの処理中に実施するようにしてもよい。
【００７２】
この場合、制御装置３０は、図９に示すフローチャートに対応したプログラムを短時間毎に繰り返し実行する。制御装置３０は、ステップ２００にてプログラムの実行を開始する度に、ステップ２０２，２０４にて、車両Ｍの挙動状態に基づいて推定ハンドル角度θｓを導出する（推定ハンドル角度導出手段）。まずステップ２０２にて、ヨーレートセンサ３２からのヨーレートの方向及び大きさを表す信号を実際のヨーレートである実ヨーレートＲωとして検出し、この実ヨーレートＲωおよび上記数３から操舵輪の切れ角ξｓを導出する（操舵輪切れ角推定手段）。そして、ステップ２０４にて、ステップ２０２にて導出した操舵輪の切れ角ξｓに対応する推定ハンドル角度θｓを導出する（推定ハンドル角度導出手段）。この推定ハンドル角度θｓの時間経過を図１０に示す。ハンドル１５に遊びがあるので、ハンドル１５を回動し始めてから実際に操舵輪が切れ始めるまで、すなわちハンドル回動開始時点（ｔ１）から推定ハンドル角度θｓ変動開始時点（ｔ２）までは、推定ハンドル角度θｓは０のままである。そして、操舵輪が切れ始めた時点（ｔ２）以降は、実際のハンドル１５の回動量に応じた推定ハンドル角度θｓが導出される。
【００７３】
また、上述したステップ１０４と同様な処理によって実際のハンドル角度θが算出されている。このハンドル角度θの時間経過も図１０に示す。ハンドル１５を回動し始めてから実際に操舵輪が切れ始めるまで、すなわちハンドル回動開始時点（ｔ１）から推定ハンドル角度θｓ変動開始時点（ｔ２）までは、ハンドル１５に遊びがあるのでハンドル１５の操作にはほとんど抵抗がないため、ハンドル角度θはリニアに増加する。そして、操舵輪が切れ始めた時点（ｔ２）以降は、ハンドル１５に遊びがなくなりハンドル１５の操作に応じて操舵輪が操舵されるため、操舵輪の実際のハンドル１５の回動量に応じたハンドル角度θが導出される。
【００７４】
制御装置３０は、ステップ２０６にて、これらハンドル角度θと推定ハンドル角度θｓとに基づいて偏差の有無および程度を検出する（偏差検出手段）。具体的には、ハンドル回動開始時点（ｔ１）と推定ハンドル角度θｓの変動開始時点（ｔ２）とがずれていない場合には、「偏差はない」と判断し、ハンドル回動開始時点（ｔ１）と推定ハンドル角度θｓの変動開始時点（ｔ２）とがずれている場合には、「偏差がある」と判断する。そして、推定ハンドル角度θｓの変動開始時点（ｔ２）におけるハンドル角度θと推定ハンドル角度θｓとの差を偏差の程度（ハンドルの遊び量θｂ）として検出する。
【００７５】
制御装置３０は、ステップ２０８にて、ステップ２０６にて検出された偏差に適した第１マップを、予め記憶されている複数の第１マップのなかから選択する（選択手段）。例えば、遊び量θｂが１０°、２０°、３０°の第１マップが予め記憶されており、このなかから検出された偏差に適したものが選択される。
【００７６】
そして、制御装置３０は、図２に示すフローチャートのステップ１０８（またはステップ１３０）にて選択手段によって選択された第１マップに基づいて操舵輪の切れ角ξを導出する。
【００７７】
この変形例によれば、ステップ２０６にて、ハンドル角度θと推定ハンドル角度θｓとに基づいて偏差の有無および程度を検出し、ステップ２０８にて、ステップ２０６によって検出された偏差に適した第１マップ（または第１演算式）を複数の第１マップ（または第１演算式）のなかから選択する。そして、選択された第１マップ（または第１演算式）に基づいて、正確な操舵輪の切れ角ξを導出することができる。したがって、互いに異なる偏差の車両にも個々の偏差にそれぞれ的確に対応することができ、また偏差が変化してもその変化に的確に対応した操舵輪の切れ角ξを正確に導出することができる。
【００７８】
また、上記第２の変形例において、互いに異なる複数の偏差に対応した第２マップ（または第２演算式）を制御装置３０に記憶し、偏差の有無および程度を検出し、検出された偏差に適した第２マップ（または第２演算式）を選択し、その選択された第２マップ（または第２演算式）に基づいて操舵輪の切れ角を導出するようにしてもよい。これによっても、第２の変形例と同様な作用・効果を得ることができる。
【図面の簡単な説明】
【図１】本発明の一実施の形態に係る車両の姿勢制御装置にて採用した車両の姿勢制御装置の概略図である。
【図２】図１の制御装置にて実行されるプログラムを表すフローチャートである。
【図３】ハンドル角度を補正ハンドル角度に補正するための第１マップを示す図である。
【図４】ハンドル角度を操舵輪の切れ角に補正するための第２マップを示す図である。
【図５】図１の制御装置にて実行されるプログラムを表す他のフローチャートである。
【図６】ハンドル角度を補正ハンドル角度（または操舵輪の切れ角）に補正するための他の第１マップ（または第２マップ）を示す図である。
【図７】ハンドル角度を補正ハンドル角度（または操舵輪の切れ角）に補正するための他の第１マップ（または第２マップ）を示す図である。
【図８】車両走行時の実ヨーレートと補正された操舵輪の切れ角から計算した車両のヨーレートとの時間変化を示す図である。
【図９】図１の制御装置にて実行されるプログラムを表すフローチャートである。
【図１０】ハンドル角度と推定ハンドル角度の時間変化を示す図である。
【図１１】従来技術による補正されたハンドル角度から計算した車両のヨーレートと実ヨーレートとの時間変化を示す図である。
【符号の説明】
１０…エンジン、１１…プロペラシャフト、１２…ディファレンシャル装置、１３，１４…左右のリヤアクスルシャフト、１５…ステアリングホイール（ハンドル）、１６…ステアリングシャフト、１７…舵取機構、１８…タイロッド、２０…車両用制動装置、２１…ブレーキペダル、２２…マスタシリンダ、２３…ブレーキ調圧ユニット、２４…ブレーキ制御装置、２５，２６，２７，２８…各ホイールシリンダ、３０…制御装置３０、３１…操舵角センサ、Ｓｆｌ，Ｓｆｒ，Ｓｒｌ，Ｓｒｒ…車輪速センサ、３２…ヨーレートセンサ、Ｍ…車両、Ｗｆｌ，Ｗｆｒ，Ｗｒｌ，Ｗｒｒ…左右前後輪。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle attitude control device.
[0002]
[Prior art]
Conventionally, as this type of device, a target yaw rate is set based on a steering wheel angle and a vehicle speed, and an actual yaw rate (actual yaw rate) of a vehicle is detected by a yaw rate sensor, and a yaw rate difference that is a difference between the target yaw rate and the actual yaw rate Is known, and the attitude of the vehicle is controlled so as to reduce this yaw rate difference. Specifically, the attitude of the vehicle in the yawing direction and / or rolling direction is controlled by controlling the braking force of the wheels or / and the output of the engine. The steering wheel angle in such an apparatus is generally detected by a steering angle sensor that detects a relative steering angle. Then, the zero point position of the rudder angle sensor is determined quickly and accurately, and the detected steering wheel angle is corrected based on the determined zero point position (see, for example, Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 06-234370 (pages 3, 4 and 2)
[0004]
[Problems to be solved by the invention]
However, in a vehicle with low steering rigidity or a vehicle with reduced rigidity, i.e., a vehicle having handle play or play, the increase (or decrease) of the steering wheel angle and the actual turning angle of the steering wheel (or In this case, even if the steering wheel angle zero point position is derived accurately and accurately as in the conventional device, the steering wheel can be accurately corrected only by correcting the steering wheel angle based on the zero point position. There was a problem that it was not possible to obtain the cutting angle. That is, as shown in FIG. 11, the yaw rate of the vehicle calculated from the steering wheel angle deviates from the actual yaw rate.
[0005]
An object of the present invention is to provide a vehicle that accurately and accurately controls the attitude of a vehicle by deriving an accurate steering wheel turning angle from the steering wheel angle even in a vehicle having a low steering wheel rotational direction rigidity or a vehicle having a reduced rigidity. It is in providing the attitude control device of the.
[0006]
[Means for Solving the Problem, Action and Effect of the Invention]
In order to solve the above-mentioned problem, the structural feature of the invention according to claim 1 is that the steering angle calculation means for calculating the steering angle of the vehicle and the turning angle of the steering wheel of the vehicle steered by the operation of the steering wheel of the vehicle Steering wheel turning angle deriving means for deriving the steering wheel angle calculated by the steering wheel angle calculating means based on the deviation between the steering wheel angle due to low rigidity in the rotational direction of the steering wheel of the vehicle and the turning angle of the steering wheel; This is provided with first attitude control means for controlling the attitude of the vehicle based on the steering wheel turning angle derived by the steering wheel turning angle deriving means.
[0007]
According to this, the steering wheel turning angle deriving means sets the turning angle of the steering wheel of the vehicle that is steered by the operation of the steering wheel of the vehicle, the steering wheel angle calculated by the steering wheel angle calculating means to the low rotation direction of the steering wheel of the vehicle. The first posture control means is derived based on the deviation between the steering wheel angle due to the rigidity and the steering wheel turning angle. Control attitude. Therefore, even in the case where a deviation occurs between the increase in the steering wheel angle and the actual turning angle of the steering wheel in a vehicle with low rigidity in the rotation direction of the steering wheel or a vehicle with low rigidity, accurate steering is possible. The wheel turning angle can be derived from the steering wheel angle, and the vehicle attitude control can be performed reliably and accurately.
[0008]
The structural feature of the invention according to claim 2 is that the actual yaw rate detecting means for detecting the actual yaw rate of the vehicle, the handle angle calculating means for calculating the handle angle of the vehicle, and the vehicle steered by the operation of the handle of the vehicle. Steering wheel which derives the steering angle of the steering wheel by correcting the steering wheel angle calculated by the steering wheel angle calculation means based on the deviation between the steering angle of the steering wheel and the steering wheel angle due to the low rigidity in the rotation direction of the steering wheel of the vehicle A turning angle deriving means, a target yaw rate calculating means for calculating a target yaw rate of the vehicle based on the turning angle of the steering wheel derived by the steering wheel turning angle deriving means, an actual yaw rate detected by the actual yaw rate detecting means, Yaw rate difference calculating means for calculating a yaw rate difference by subtracting the target yaw rate calculated by the target yaw rate calculating means Is that having the second attitude control means for controlling the attitude of the vehicle based on the yaw rate difference calculated by the yaw rate difference calculation means.
[0009]
According to this, the steering wheel turning angle deriving means sets the turning angle of the steering wheel of the vehicle that is steered by the operation of the steering wheel of the vehicle, the steering wheel angle calculated by the steering wheel angle calculating means to the low rotation direction of the steering wheel of the vehicle. The target yaw rate calculating means calculates the target yaw rate of the vehicle based on the steering wheel turning angle derived by the steering wheel turning angle deriving means. The yaw rate difference calculation means calculates the yaw rate difference by subtracting the actual yaw rate detected by the actual yaw rate detection means and the target yaw rate calculated by the target yaw rate calculation means, and the second attitude control means calculates the yaw rate. The attitude of the vehicle is controlled based on the yaw rate difference calculated by the difference calculating means. Therefore, even if there is a deviation between the increase in the steering wheel angle and the actual turning angle of the steered wheel in a vehicle with a low rigidity in the rotational direction of the steering wheel or a vehicle with a reduced rigidity, the accurate target The yaw rate, and thus the yaw rate difference, can be derived from the steering wheel angle, and the vehicle attitude control can be performed reliably and accurately.
[0010]
According to a third aspect of the present invention, in the first or second aspect, the steering wheel cutting angle deriving means includes a first map or a first arithmetic expression for correcting the steering wheel angle based on the deviation. And a correction handle angle deriving unit for deriving a correction handle angle by correcting the handle angle calculated by the handle angle calculation unit based on the first map or the first arithmetic expression, and derived by the correction handle angle deriving unit. Deriving the turning angle of the steered wheel from the corrected steering wheel angle.
[0011]
According to this, the corrected handle angle deriving means corrects the handle angle based on the first map or the first arithmetic expression for correcting the handle angle based on the deviation between the handle angle and the turning angle of the steered wheel, thereby correcting the handle. The steering wheel turning angle deriving unit derives the steering wheel turning angle from the correction handle angle derived by the correction handle angle deriving unit. Accordingly, an accurate steering wheel turning angle can be derived from the steering wheel angle.
[0012]
According to a fourth aspect of the present invention, in the first or second aspect, the steering wheel cutting angle deriving means is configured to use the second map or the second calculation indicating the relationship between the steering wheel angle and the steering wheel cutting angle. The steering angle of the steered wheel steered by the operation of the steering wheel of the vehicle is derived by correcting the steering wheel angle calculated by the steering wheel angle calculation means based on the second map or the second arithmetic expression. .
[0013]
According to this, since the steering wheel turning angle deriving unit corrects the steering wheel angle calculated by the steering wheel angle calculating unit based on the second map or the second arithmetic expression and derives the steering wheel turning angle, The turning angle of the steered wheel can be accurately derived from the steering wheel angle.
[0014]
The structural feature of the invention according to claim 5 is that, according to claim 3, the steering wheel break angle estimation means for estimating the turning angle of the steered wheel based on the behavior state of the vehicle, and the steering wheel break angle estimation means are estimated. Based on the estimated handle angle deriving means for deriving the estimated handle angle corresponding to the turning angle of the steered wheel, the handle angle calculated by the handle angle calculating means, and the estimated handle angle derived by the estimated handle angle deriving means Deviation detecting means for detecting the presence or absence and degree of deviation, a plurality of first maps or first arithmetic expressions respectively corresponding to a plurality of different deviations, and a first map suitable for the deviation detected by the deviation detecting means or The apparatus further comprises a selection means for selecting the first arithmetic expression from the plurality of first maps or the first arithmetic expressions, and the steering wheel turning angle deriving means is included in the selection means. And to derive the steering angle of the steering wheel based on the first map or first operation expression is selected me.
[0015]
According to this, the deviation detecting means detects the presence or absence and degree of deviation based on the handle angle calculated by the handle angle calculating means and the estimated handle angle derived by the estimated handle angle deriving means, and the selecting means The first map or the first arithmetic expression suitable for the deviation detected by the deviation detecting means is selected from the plurality of first maps or the first arithmetic expression. Then, based on the selected first map or the first arithmetic expression, an accurate steering wheel turning angle can be derived. Therefore, it is possible to accurately correspond to individual deviations of vehicles having different deviations, and to accurately derive the turning angle of the steered wheels corresponding to the change even if the deviation changes.
[0016]
According to a sixth aspect of the present invention, the structural feature of the invention according to the sixth aspect is that, in the fourth aspect, the steering wheel cutting angle estimation means for estimating the steering wheel cutting angle based on the behavior state of the vehicle, and the steering wheel cutting angle estimation means are estimated. Based on the estimated handle angle deriving means for deriving the estimated handle angle corresponding to the turning angle of the steered wheel, the handle angle calculated by the handle angle calculating means, and the estimated handle angle derived by the estimated handle angle deriving means Deviation detecting means for detecting the presence and degree of deviation, a plurality of second maps or second arithmetic expressions respectively corresponding to a plurality of different deviations, and a second map suitable for the deviation detected by the deviation detecting means or The system further comprises a selection means for selecting the second arithmetic expression from a plurality of second maps or second arithmetic expressions, and the steering wheel turning angle deriving means is provided as the selection means. And to derive the steering angle of the steering wheel based on the second map or second operation expression is selected me.
[0017]
According to this, the deviation detecting means detects the presence or absence and degree of deviation based on the handle angle calculated by the handle angle calculating means and the estimated handle angle derived by the estimated handle angle deriving means, and the selecting means The second map or the second arithmetic expression suitable for the deviation detected by the deviation detecting means is selected from the plurality of second maps or second arithmetic expressions. Then, based on the selected second map or the second arithmetic expression, an accurate steering wheel turning angle can be derived. Therefore, it is possible to accurately correspond to individual deviations of vehicles having different deviations, and to accurately derive the turning angle of the steered wheels corresponding to the change even if the deviation changes.
[0018]
A structural feature of the invention according to claim 7 is that in claim 3, the first map or the first arithmetic expression suitable for the deviation for each vehicle generated between the steering wheel angle and the steering wheel turning angle is provided in advance. Steering wheel turning angle deriving means is for deriving the steering wheel turning angle based on the first map or the first arithmetic expression.
[0019]
According to this, if the deviation of each vehicle is known in advance, the first map or the first arithmetic expression suitable for the deviation is provided in advance, and the steering wheel turning angle is derived based on the first map or the first arithmetic expression. Since the means derives the turning angle of the steering wheel, the turning angle of the steering wheel can be accurately derived with a simpler configuration.
[0020]
A structural feature of the invention according to claim 8 is that in claim 4, the second map or the second arithmetic expression suitable for the deviation for each vehicle generated between the steering wheel angle and the turning angle of the steered wheels is provided in advance. Steering wheel turning angle deriving means derives the steering wheel turning angle based on the second map or the second arithmetic expression.
[0021]
According to this, if the deviation of each vehicle is known in advance, the second map or the second arithmetic expression suitable for the deviation is prepared in advance, and the steering wheel turning angle is derived based on the second map or the second arithmetic expression. Since the means derives the turning angle of the steering wheel, the turning angle of the steering wheel can be accurately derived with a simpler configuration.
[0022]
The structural feature of the invention according to claim 9 is that, in claim 3, claim 5 and claim 7, the first map or the first arithmetic expression includes a hysteresis with respect to the rotational direction of the steering wheel of the vehicle. . According to this, the handle angle can be accurately corrected regardless of whether the handle is cut or returned.
[0023]
The structural feature of the invention according to claim 10 is that, in claim 4, claim 6 and claim 8, the second map or the second arithmetic expression includes hysteresis with respect to the rotational direction of the steering wheel of the vehicle. . According to this, it is possible to accurately derive the turning angle of the steered wheel corresponding to the steering wheel angle in either case of turning the steering wheel or turning it back.
[0024]
The constitutional feature of the invention according to claim 11 is that in claim 3, claim 5 and claim 7, the first map or the first arithmetic expression is a deviation between the steering angle of the vehicle and the actual turning angle of the steered wheels. It is configured to cancel. According to this, it is possible to derive a corrected handle angle obtained by accurately and reliably correcting the handle angle calculated by the handle angle calculating means based on the first map or the first arithmetic expression.
[0025]
According to a twelfth aspect of the present invention, in the fourth, sixth and eighth aspects, the second map or the second arithmetic expression is a deviation between the steering angle of the vehicle and the actual turning angle of the steered wheel. It is configured to cancel. According to this, the actual turning angle of the steered wheel can be accurately and reliably derived from the steering wheel angle calculated by the steering wheel angle calculating means based on the second map or the second arithmetic expression.
[0026]
According to a thirteenth aspect of the present invention, in any one of the first to twelfth aspects, the attitude control means controls the braking force of the wheels or / and the output of the engine to thereby control the yawing direction of the vehicle or / and It is to control the posture in the rolling direction. According to this, it is possible to accurately and reliably control the attitude of the vehicle in the yawing direction and / or the rolling direction.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
a) First embodiment
Hereinafter, a first embodiment of a vehicle attitude control device according to the present invention will be described with reference to the drawings. As shown in FIG. 1, this vehicle attitude control device is a rear wheel drive type equipped with a vehicle braking device 20 capable of independently applying a braking force to the left and right front and rear wheels Wfl, Wfr, Wrl, Wrr of the vehicle. This is applied to the vehicle M.
[0028]
The vehicle M includes an engine 10 that is disposed vertically on the front of the vehicle body. The engine 10 is connected to left and right rear wheels Wrl and Wrr via a propeller shaft 11, a differential device 12, and left and right rear axle shafts 13 and 14, and the left and right rear wheels Wrl and Wrr are driven by the output torque of the engine 10. It has become so. The vehicle M is provided with a steering wheel (handle) 15 that is operated by the driver. The steering wheel 15 is integrally connected to a steering shaft 16, and the steering shaft 16 is connected to a tie rod 18 via a steering mechanism 17, and left and right front wheels Wfl and Wfr as steering wheels are attached to the tie rod 18. The left and right front wheels Wfl, Wfr are steered by the operation 15.
[0029]
The vehicle braking device 20 includes a master cylinder 22 that pumps hydraulic brake oil in response to a depression operation of the brake pedal 21 and a plurality of electromagnetic valves (not shown), and includes left and right front and rear wheels Wfl, Wfr, Wrl, Wrr. The brake pressure adjusting unit 23 for adjusting the hydraulic pressure supplied to each wheel cylinder 25, 26, 27, 28, and the control of switching the state of each electromagnetic valve of the brake pressure adjusting unit 23 in response to a command from the control device 30 described later And a brake control device 24 that controls the hydraulic pressure applied to the wheel cylinders 25, 26, 27, and 28, that is, the braking force applied to the wheels Wfl, Wfr, Wrl, and Wrr.
[0030]
The vehicle M includes a control device 30, which includes a steering angle sensor 31 that is provided on the steering shaft 16 and detects the handle angle θ of the handle 15 of the vehicle M, and left and right front and rear wheels Wfl, Wfr, Wrl. , Wrr provided in the vicinity of the wheel speed sensors Sfl, Sfr, Srl, Srr for detecting the rotational speeds of the left and right front and rear wheels Wfl, Wfr, Wrl, Wrr, respectively, and assembled in the vicinity of the center of gravity of the vehicle body. A yaw rate sensor 32 for detecting the yaw rate (actual yaw rate Rω) is connected.
[0031]
The steering angle sensor 31 is a pulse train signal whose level changes every time the steering shaft 16 rotates by a predetermined angle. The phase is different by a quarter period and the phase advance side depends on the rotation direction of the steering shaft 16. Two-phase pulse train signals that are opposite to each other are output. The wheel speed sensors Sfl, Sfr, Srl, Srr detect the rotational speeds of the left and right front and rear wheels Wfl, Wfr, Wrl, Wrr, respectively, and pick up the rotations of the left and right front and rear wheels Wfl, Wfr, Wrl, Wrr, respectively. As a result, a pulse train signal having a period inversely proportional to each rotation speed is output. The yaw rate sensor 32 includes an oscillator and is configured by an angular velocity sensor that detects the angular velocity around the vertical axis of the center of gravity of the vehicle body using Coriolis force, and indicates the direction of the yaw rate acting on the vehicle body and the magnitude of the yaw rate. A signal representing a magnitude proportional to the height is output.
[0032]
In addition, the vehicle M is provided with an engine control device 40 that receives an instruction from the control device 30 and controls the opening degree of the throttle (not shown) of the engine 10 to control the output torque.
[0033]
The control device 30 includes a microcomputer (not shown), and the microcomputer includes an input / output interface, a CPU, a RAM, and a ROM (all not shown) connected via a bus. . The CPU executes a program corresponding to the flowchart of FIG. 2 to control the posture of the vehicle M, and the ROM stores the program, the steering wheel angle θ due to low rigidity in the rotational direction of the steering wheel 15 and the cutting of the steering wheel. The first map (or the first arithmetic expression) for correcting the handle angle θ based on the deviation from the angle ξ is stored, and the RAM temporarily stores the arithmetic value related to the control. The first map is not limited to the ROM, but may be stored in a storage device connected to the CPU. The steering wheel turning angle ξ refers to the angle of the steering direction of the steering wheel with respect to the direction in which the vehicle M travels straight.
[0034]
As shown in FIG. 3, the first map is a deviation between the steering wheel angle θ calculated as described later and the steering wheel angle θ due to the low rigidity in the rotational direction of the steering wheel 15 and the turning angle ξ of the steering wheel, that is, play or A relationship with the corrected handle angle θa obtained by correcting the handle angle θ in consideration of the play amount θb of the handle 15 due to rattling is shown. Further, the first map is configured to cancel the deviation between the steering wheel angle θ of the vehicle M and the actual turning angle ξ of the steered wheel.
[0035]
This first map is created as follows. First, the play amount θb (the above deviation) of the handle 15 of the vehicle M is measured. In order to prevent the influence of the deviation particularly near the neutral point of the handle angle θ, the corrected handle angle θa of the predetermined range is 0 ° near the neutral point, and the other ranges with respect to the handle angle θ. To create a linear change. That is, when the handle angle θ is in the range of −θb ≦ θ ≦ + θb, the correction handle angle θa is 0 °, and when the handle angle θ is in the range of θ <−θb, the correction handle is When the handle angle θ is in the range of θb <θ so that the angle θa is θa = θc + c1 · θ, the corrected handle angle θa is created so that θa = −θd + c2 · θ. C1 and c2 are proportional constants of the corrected handle angle θa with respect to the handle angle θ.
[0036]
The first map created in this way is suitable for the deviation for each vehicle that occurs between the steering wheel angle θ and the turning angle ξ of the steered wheel, that is, the play amount θb of the steering wheel 15, and is measured in advance for each vehicle. What corresponds to the deviation is stored in the control device 30. Note that the first arithmetic expression may be used instead of the first map. The first arithmetic expression is derived based on the first map.
[0037]
Next, the operation of the vehicle attitude control apparatus configured as described above will be described with reference to the flowchart of FIG. When the ignition switch of the vehicle M (not shown) is in the on state, the control device 30 repeatedly executes the program corresponding to the above flowchart every predetermined short time. The control device 30 calculates the vehicle body speed V and the steering wheel angle θ each time the program starts to be executed in step 100 of FIG. 2, and detects the actual yaw rate Rω (steps 102 to 106).
[0038]
In step 102, the control device 30 first calculates the vehicle body speed V of the vehicle M. Specifically, based on each pulse train signal input from each of the wheel speed sensors Sfl, Sfr, Srl, Srr, a value inversely proportional to the period of each pulse train signal is set to each of the left and right front and rear wheels Wfl, Wfr, Wrl, Wrr. Calculate as wheel speed. A value obtained by averaging these wheel speeds is calculated as the vehicle body speed V. A value obtained by averaging the wheel speeds of the left and right front wheels Wfl and Wfr or the left and right rear wheels Wrl and Wrr may be calculated as the vehicle body speed V. Further, a vehicle speed sensor that picks up the rotation of the output shaft of a transmission (not shown) and outputs a pulse train signal having a cycle inversely proportional to the rotation speed is connected to the control device 30, and the control device 30 is input from the vehicle speed sensor. A value inversely proportional to the period of the pulse train signal may be calculated as the vehicle body speed V based on the pulse train signal.
[0039]
In step 104, the control device 30 calculates the handle angle θ of the vehicle M (handle angle calculating means). That is, the steering wheel angle θ is based on the two-phase pulse train signal input from the steering angle sensor 30 as shown in the following formula 1, and the rotation direction (two-phase) of the steering shaft 31 every time the level of both pulse train signals changes. Is detected by increasing or decreasing the previous handle angle θ by a predetermined angle Δθ in accordance with the change in the level of the pulse train signal.
[0040]
[Expression 1]
Handle angle θ = previous handle angle θ + added value × Δθ
The added value of Equation 1 indicates the rotation direction of the handle 15 and is determined based on how the previous value and the current value of the two-phase pulse train signal input from the steering angle sensor 31 change. For example, if the previous value and the current value are the same as (0, 0), the added value is 0; if the previous value of (0, 0) is (0, 1), the added value is +1; If the previous value of (0, 0) is (1, 0), the added value is -1.
[0041]
Immediately after the ignition switch (not shown) is turned on, the initial value of the handle angle θ is reset to 0, and the subsequent calculation of the handle angle θ is executed based on this. Further, the handle angle θ represents only a relative angle from the initial value, and does not represent an absolute angle. Therefore, a neutral point of the handle angle θ is calculated and corrected based on the calculated neutral point. For the first time, the handle angle θ, which is an absolute angle from the neutral point, is calculated.
[0042]
In step 106, the control device 30 detects a signal representing the direction and magnitude of the yaw rate from the yaw rate sensor 32 as the actual yaw rate Rω that is the actual yaw rate (actual yaw rate detecting means). The actual yaw rate Rω may be calculated based on the wheel speeds of the left and right front wheels Wfl, Wfr (or the left and right rear wheels Wrl, Wrr).
[0043]
In steps 108 and 110, the control device 30 calculates the steering wheel turning angle ξ from the steering wheel angle θ calculated in step 104 described above (steering wheel turning angle derivation means). First, in step 108, a corrected handle angle θa is derived from the handle angle θ (corrected handle angle deriving means). Specifically, the corrected handle angle θa is derived by correcting the handle angle θ based on the first map (or the first arithmetic expression) shown in FIG. When the handle angle θ is in the range of −θb ≦ θ ≦ + θb, the corrected handle angle θa is 0 °, and when the handle angle θ is in the range of θ <−θb, the corrected handle angle θa is set. When the handle angle θ is in the range of θb <θ so that θa = θc + c1 · θ, the corrected handle angle θa is corrected to be θa = −θd + c2 · θ and corresponds to the handle angle θ. The correction handle angle θa is derived respectively.
[0044]
In step 110, the control device 30 derives the steering wheel turning angle ξ from the corrected steering wheel angle θa derived in step 108 by the following formula 2.
[0045]
[Expression 2]
Steering wheel turning angle ξ = c3 × correction handle angle θa
Note that c3 is a proportional constant of the steering wheel turning angle ξ with respect to the correction handle angle θa.
[0046]
Next, in step 112, the control device 30 calculates the target yaw rate Tω based on the handle angle θ by the following equation (3) (target yaw rate calculating means).
[0047]
[Equation 3]

In Equation 3, A is the stability factor, and L is the wheel base of the vehicle M.
[0048]
Then, when the calculation of the target yaw rate Tω is completed, the control device 30 controls the posture of the vehicle M by the processing of steps 114 to 120 (first posture control means). In step 114, the control device 30 calculates a yaw rate difference Δω that is a difference value between the actual yaw rate Rω detected in step 106 and the target yaw rate Tω calculated in step 112 (yaw rate difference calculating means). In step 116, if the absolute value | Δω | of the calculated yaw rate difference Δω is equal to or greater than the predetermined value Th0, the vehicle M is not in a stable state, so the program proceeds to step 118 to control the attitude of the vehicle M. Is implemented (second attitude control means).
[0049]
In step 118, the control device 30 sends a command to the brake control device 24 to control the braking force applied to each wheel Wfl, Wfr, Wrl, Wrr so as to control the posture of the vehicle M to be in a stable state. To do. That is, the control device 30 controls the attitude of the vehicle M in the yawing direction and / or rolling direction by controlling the braking force of each wheel Wfl, Wfr, Wrl, Wrr and / or the output of the engine 10. For example, when the vehicle M is in an understeer state, a braking force is applied to the inner wheel to generate an inward moment in the vehicle M. When the vehicle M is in an oversteer state, the braking force is applied to the outer wheel. To generate an outward moment in the vehicle M. The control device 30 also sends a command to the engine control device 40 to control the throttle opening of the engine 10 and control the output torque so as to control the posture of the vehicle M to be in a stable state. For example, when the vehicle M is understeered, the throttle is closed and the output torque is suppressed. Thereafter, the program is advanced to step 122 and temporarily terminated.
[0050]
On the other hand, if the absolute value | Δω | of the yaw rate difference Δω is less than the predetermined value Th0 in step 116, the vehicle M is in a stable state, so the program proceeds to step 120 to perform the above-described attitude control of the vehicle M. Not implemented. Thereafter, the program is advanced to step 122 and temporarily terminated.
[0051]
As described above, according to the first embodiment, in step 108 and 110, the turning angle ξ of the steered wheel of the vehicle M steered by the operation of the handle 15 of the vehicle M is calculated in step 104. The obtained steering wheel angle θ is corrected and derived on the basis of the deviation between the steering wheel angle θ due to the low rigidity of the steering wheel 15 of the vehicle M and the turning angle ξ of the steering wheel. A target yaw rate Tω of the vehicle M is calculated based on the derived steering wheel turning angle ξ, and in step 114, the actual yaw rate (actual yaw rate Rω) detected in step 106 and the target yaw rate calculated in step 112 are calculated. The yaw rate difference Δω is calculated by subtracting Tω, and the yaw rate difference Δω calculated in step 114 is calculated in steps 116 and 118. Zui is to control the posture of the vehicle. Therefore, even in the case where a deviation occurs between the increase in the handle angle θ and the increase in the actual turning angle ξ of the steering wheel in a vehicle having low rigidity in the rotational direction of the handle 15 or a vehicle having reduced rigidity, The accurate target yaw rate Tω and thus the yaw rate difference Δω can be derived from the steering wheel angle θ, and the vehicle attitude control can be performed reliably and accurately.
[0052]
Further, according to the first embodiment, in step 108, the first map (or the first map) for correcting the steering wheel angle θ based on the deviation between the steering wheel angle θ and the steering wheel turning angle ξ. The corrected steering wheel angle θa is derived based on the calculation formula), and in step 110, the steering wheel turning angle ξ is derived from the corrected steering wheel angle θa derived in step 108. Therefore, an accurate steering wheel turning angle ξ can be derived from the steering wheel angle θ.
[0053]
Further, according to the first embodiment, the first map (or the first arithmetic expression) is configured to cancel the deviation between the steering angle θ of the vehicle M and the actual turning angle ξ of the steered wheel. Therefore, it is possible to derive a corrected handle angle θa in which the handle angle θ calculated in step 104 is corrected accurately and reliably based on the first map (or the first arithmetic expression).
[0054]
In addition, according to the first embodiment, the control device 30 is a first map (or a first arithmetic expression) suitable for a deviation for each vehicle that occurs between the steering wheel angle θ and the steering wheel turning angle ξ. In advance, in steps 108 and 110, the turning angle ξ of the steered wheel is derived based on the first map (or the first arithmetic expression). Therefore, if the deviation of each vehicle is known in advance, the steering wheel turning angle ξ can be accurately derived with a simpler configuration.
[0055]
Further, according to the first embodiment, the control device 30 controls the braking force of each wheel Wfl, Wfr, Wrl, Wrr or / and the output of the engine 10 to control the yawing direction of the vehicle M or / Since the attitude in the rolling direction is controlled, the attitude of the vehicle M in the yawing direction and / or the rolling direction can be accurately and reliably controlled.
[0056]
b) Second embodiment
In the first embodiment, the vehicle attitude control device stores the first map or the first arithmetic expression for correcting the steering wheel angle θ based on the deviation, and the control device 30 performs step 108. In step 110, the steering wheel angle θ is corrected based on the first map or the first arithmetic expression to derive the corrected steering wheel angle θa. In step 110, the steering wheel turning angle ξ is calculated from the calculated corrected steering wheel angle θa. However, instead of this, the vehicle attitude control device stores the second map or the second arithmetic expression indicating the relationship between the steering wheel angle θ and the steering wheel turning angle ξ. The turning angle ξ of the steered wheel may be derived by correcting θ based on the second map or the second arithmetic expression.
[0057]
The second map is for correcting the steering wheel angle θ based on the deviation between the steering wheel angle θ due to low rigidity in the rotational direction of the steering wheel 15 and the turning angle ξ of the steered wheel, and as shown in FIG. The relationship between the handle angle θ and the steering angle turning angle ξ is shown in consideration of the play amount θb of the handle 15 due to play or backlash. Further, the second map is configured to cancel the deviation between the steering wheel angle θ of the vehicle M and the actual turning angle ξ of the steered wheel.
[0058]
The second map is created as follows in the same manner as the first map. First, the play amount θb (the above deviation) of the handle 15 of the vehicle M is measured. In order to prevent the influence of deviation particularly near the neutral point of the steering wheel angle θ, the steering wheel turning angle ξ of the predetermined range is 0 ° near the neutral point, and the other range is the steering wheel angle θ. It is created so as to change linearly. That is, when the handle angle θ is in the range of −θb ≦ θ ≦ + θb, the turning angle ξ is 0 °, and when the handle angle θ is in the range of θ <−θb, the turning angle ξ When the handle angle θ is in the range of θb <θ, the cutting angle ξ is created so that θa = −ξ2 + c5 · θ. C4 and c5 are proportional constants of the cutting angle ξ with respect to the handle angle θ.
[0059]
The second map created in this way is suitable for the deviation for each vehicle generated between the steering wheel angle θ and the steering wheel turning angle ξ, that is, the play amount θb of the steering wheel 15, and is measured in advance for each vehicle. What corresponds to the deviation is stored in the control device 30. Note that the second arithmetic expression may be used instead of the second map. The second arithmetic expression is derived based on the second map.
[0060]
When the steering wheel turning angle ξ is derived by correction based on the second map or the second arithmetic expression described above, the processing of step 130 shown in FIG. 5 is performed instead of the processing of steps 108 and 110 described above. Just do it. In step 130, the control device 30 derives the steering wheel turning angle ξ from the steering wheel angle θ calculated in step 104 described above based on the second map (or the second arithmetic expression) (steering wheel cutting angle derivation). means). Specifically, when the handle angle θ is in the range of −θb ≦ θ ≦ + θb, the turning angle ξ is 0 °, and when the handle angle θ is in the range of θ <−θb, the turning angle ξ Ξ = ξ1 + c4 · θ, and when the handle angle θ is in the range of θb <θ, the turning angle ξ is θa = −ξ2 + c5 · θ.
[0061]
According to the second embodiment as described above, in addition to the operation and effect of the first embodiment, in step 130, the control device 30 sets the handle angle θ calculated in step 104 to the second map in step 130. Alternatively, since the steering wheel turning angle ξ is derived by correction based on the second arithmetic expression, the steering wheel turning angle ξ can be easily and accurately derived from the steering wheel angle θ.
[0062]
Further, according to the second embodiment, the second map (or the second arithmetic expression) is configured to cancel the deviation between the steering angle θ of the vehicle M and the actual turning angle ξ of the steered wheel. Therefore, the steering wheel turning angle ξ obtained by accurately and reliably correcting the steering wheel angle θ calculated in step 104 based on the second map (or the second arithmetic expression) can be derived.
[0063]
In addition, according to the second embodiment, the control device 30 uses the second map (or the second arithmetic expression) suitable for the deviation for each vehicle that occurs between the steering wheel angle θ and the steering wheel turning angle ξ. In advance, and in step 130, the turning angle ξ of the steered wheel is derived based on the second map (or the second arithmetic expression). Therefore, if the deviation of each vehicle is known in advance, the steering wheel turning angle ξ can be accurately derived with a simpler configuration.
[0064]
c) First modification
In each of the above-described embodiments, the first map (or the first arithmetic expression) and the second map (or the second arithmetic expression) may include hysteresis with respect to the rotation direction of the steering wheel 15 of the vehicle M. In this case, as shown in FIG. 6, the first map (second map) returns from the opposite direction to the path K1 starting from the intersection X1 (θb, 0) and passing through the branch point X2 (θ1, θ2). A path K3 that passes through the branch point X2 (θ1, θ2) and reaches the intersection point X3 (−θb, 0) and a branch point X4 (−θ1, −θ2) starting from the intersection point X3 (−θb, 0) A path K2 that passes through and a path K4 that returns from the opposite direction, passes through the branch point X4 (−θ1, −θ2), and reaches the intersection X1 (θb, 0). That is, if the route K1 is a route corresponding to the turning of the handle 15 to the right rotation, the route K3 is a route corresponding to the turning back to the left rotation, and the route K2 is a route corresponding to the turning to the left rotation. The route K4 is a route corresponding to switching back to the right rotation. Θb is the play amount of the handle 15.
[0065]
In this case, in step 108, the control device 30 corrects the handle angle θ based on the first map shown in FIG. 6 to derive the corrected handle angle θa (corrected handle angle deriving means). Specifically, when the handle 15 is cut when the absolute value | θ | of the handle angle θ is less than the predetermined value θ1, the handle angle θa is derived by being corrected according to the paths K1 and K2, and the handle angle When the absolute value | θ | of θ is greater than or equal to the predetermined value θ1, when the handle 15 is turned back, the steering wheel angle θa is derived with correction according to the paths K3 and K4. Further, in step 130, the control device 30 corrects the steering wheel angle θ based on the second map shown in FIG. 6 to derive the steering wheel turning angle ξ (steering wheel turning angle derivation means). Specifically, when the steering wheel 15 is cut when the absolute value | θ | of the steering wheel angle θ is less than the predetermined value θ1, the steering wheel turning angle ξ is derived by correction according to the paths K1 and K2. When the steering wheel 15 is turned back when the absolute value | θ | of the steering wheel angle θ is equal to or larger than the predetermined value θ1, the steering wheel turning angle ξ is derived with correction according to the paths K3 and K4.
[0066]
According to this modified example, the handle angle θ can be accurately corrected to the corrected handle angle θa in both cases where the handle 15 is cut and returned, and the handle angle θ is accurately handled. The turning angle ξ of the steered wheel can be derived.
[0067]
Further, as shown in FIG. 7, the first map (second map) starts from the origin X0 (0, 0) and returns from the opposite direction to the path K1 passing through the branch point X2 (θ1, θ2). A path K3 that passes through the branch point X2 (θ1, θ2) and returns to the origin X0 (0, 0), and a path that starts from the origin X0 (0, 0) and passes through the branch point X4 (−θ1, −θ2) K2 and a path K4 that returns from the opposite direction, passes through the branch point X4 (−θ1, −θ2), and returns to X0 (0, 0). That is, if the route K1 is a route corresponding to the turning of the handle 15 to the right rotation, the route K3 is a route corresponding to the turning back to the left rotation, and the route K2 is a route corresponding to the turning to the left rotation. The route K4 is a route corresponding to switching back to the right rotation.
[0068]
In this case, in step 108, the control device 30 corrects the handle angle θ based on the first map shown in FIG. 7 to derive the corrected handle angle θa (corrected handle angle deriving means). Specifically, when the handle 15 is cut when the absolute value | θ | of the handle angle θ is less than the predetermined value θ1, the handle angle θa is derived by being corrected according to the paths K1 and K2, and the handle angle When the absolute value | θ | of θ is greater than or equal to the predetermined value θ1, when the handle 15 is turned back, the steering wheel angle θa is derived with correction according to the paths K3 and K4. Further, in step 130, the control device 30 corrects the steering wheel angle θ based on the second map shown in FIG. 7 to derive the steering wheel turning angle ξ (steering wheel turning angle derivation means). Specifically, when the steering wheel 15 is cut when the absolute value | θ | of the steering wheel angle θ is less than the predetermined value θ1, the steering wheel turning angle ξ is derived by correction according to the paths K1 and K2. When the steering wheel 15 is turned back when the absolute value | θ | of the steering wheel angle θ is equal to or larger than the predetermined value θ1, the steering wheel turning angle ξ is derived with correction according to the paths K3 and K4.
[0069]
Next, the usefulness of the correction of the play amount of the steering wheel is verified by comparing the yaw rate of the vehicle calculated from the corrected turning angle ξ of the steering angle when applied to the vehicle and the actual yaw rate. . Part of both yaw rates during the test run are shown in FIG. As is clear from this figure, the yaw rate of the vehicle calculated from the corrected turning angle ξ of the steering angle is almost the same as the actual yaw rate, and the usefulness of the correction described above can be confirmed.
[0070]
According to this modified example, the handle angle θ can be accurately corrected to the corrected handle angle θa in both cases where the handle 15 is cut and returned, and the handle angle θ is accurately handled. In addition to being able to derive the steering wheel turning angle ξ, the correction handle angle θa (or the steering wheel turning angle ξ) does not change discontinuously but changes continuously, so that the steering operation near the neutral point A feeling of steering is improved because no uncomfortable feeling is imparted to the sex.
[0071]
d) Second modification
Further, in each of the above-described embodiments and modifications, a first map (or a first arithmetic expression) corresponding to a plurality of different deviations is stored in the control device 30, and the presence / absence and degree of the deviation are detected and detected. A first map (or first arithmetic expression) suitable for the deviation may be selected, and the turning angle of the steered wheels may be derived based on the selected first map (or first arithmetic expression). This process may be performed separately from the flowchart shown in FIG. 2 described above after the vehicle starts running, or may be performed during the process of the flowchart.
[0072]
In this case, the control device 30 repeatedly executes the program corresponding to the flowchart shown in FIG. 9 every short time. The control device 30 derives the estimated steering wheel angle θs based on the behavior state of the vehicle M in steps 202 and 204 every time the program execution is started in step 200 (estimated steering wheel angle deriving means). First, at step 202, a signal representing the direction and magnitude of the yaw rate from the yaw rate sensor 32 is detected as an actual yaw rate Rω as an actual yaw rate, and the steering wheel turning angle ξs is derived from the actual yaw rate Rω and the above equation (3). (Steering wheel cutting angle estimation means). In step 204, an estimated handle angle θs corresponding to the steering wheel turning angle ξs derived in step 202 is derived (estimated handle angle deriving means). The time course of this estimated handle angle θs is shown in FIG. Since there is play in the handle 15, the estimated handle from the start of turning of the handle 15 until the steering wheel actually starts to be cut, that is, from the start of turning of the handle (t 1) to the start of fluctuation of the estimated handle angle θs (t 2). The angle θs remains 0. Then, after the time point (t2) when the steering wheel starts to be cut, an estimated handle angle θs corresponding to the actual turning amount of the handle 15 is derived.
[0073]
Further, the actual handle angle θ is calculated by the same process as in step 104 described above. The time course of this handle angle θ is also shown in FIG. Since there is play in the handle 15 from the start of turning the handle 15 until the steering wheel actually starts to be cut, that is, from the start of turning the handle (t1) to the estimated change of the handle angle θs (t2), Since there is almost no resistance to operation, the handle angle θ increases linearly. Then, after the time point (t2) when the steering wheel starts to be cut, there is no play in the handle 15, and the steering wheel is steered according to the operation of the handle 15. Therefore, the handle according to the actual amount of rotation of the steering wheel 15 The angle θ is derived.
[0074]
In step 206, the control device 30 detects the presence or absence and degree of deviation based on the handle angle θ and the estimated handle angle θs (deviation detection means). Specifically, when the steering wheel rotation start time (t1) and the fluctuation start time (t2) of the estimated steering wheel angle θs are not shifted, it is determined that there is no deviation, and the steering wheel rotation start time (t1) ) And the fluctuation start time (t2) of the estimated handle angle θs are deviated from each other. Then, the difference between the handle angle θ and the estimated handle angle θs at the fluctuation start time (t2) of the estimated handle angle θs is detected as the degree of deviation (the handle play amount θb).
[0075]
In step 208, the control device 30 selects a first map suitable for the deviation detected in step 206 from a plurality of first maps stored in advance (selecting means). For example, a first map having a play amount θb of 10 °, 20 °, and 30 ° is stored in advance, and a map suitable for the detected deviation is selected.
[0076]
Then, the control device 30 derives the steering wheel turning angle ξ based on the first map selected by the selection means in step 108 (or step 130) of the flowchart shown in FIG.
[0077]
According to this modification, the presence / absence and degree of deviation are detected based on the handle angle θ and the estimated handle angle θs at step 206, and the first suitable for the deviation detected at step 206 is detected at step 208. A map (or first arithmetic expression) is selected from a plurality of first maps (or first arithmetic expressions). Then, based on the selected first map (or the first arithmetic expression), an accurate steering wheel turning angle ξ can be derived. Therefore, it is possible to accurately correspond to individual deviations of vehicles with different deviations, and it is possible to accurately derive the steering wheel turning angle ξ that accurately corresponds to the change even if the deviation changes. .
[0078]
Further, in the second modification, a second map (or a second arithmetic expression) corresponding to a plurality of different deviations is stored in the control device 30, the presence or absence and degree of deviation are detected, and the detected deviation is determined. A suitable second map (or second arithmetic expression) may be selected, and the turning angle of the steered wheels may be derived based on the selected second map (or second arithmetic expression). Also by this, the same operation and effect as the second modification can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a vehicle attitude control device employed in a vehicle attitude control device according to an embodiment of the present invention.
FIG. 2 is a flowchart showing a program executed by the control device of FIG.
FIG. 3 is a diagram showing a first map for correcting a handle angle to a corrected handle angle.
FIG. 4 is a diagram showing a second map for correcting a steering wheel angle to a turning angle of a steered wheel.
FIG. 5 is another flowchart showing a program executed by the control device of FIG. 1;
FIG. 6 is a diagram showing another first map (or second map) for correcting the handle angle to the corrected handle angle (or the turning angle of the steered wheels).
FIG. 7 is a diagram showing another first map (or second map) for correcting the handle angle to the corrected handle angle (or the turning angle of the steered wheel).
FIG. 8 is a diagram showing a time change between an actual yaw rate when the vehicle is running and a yaw rate of the vehicle calculated from the corrected steering wheel turning angle.
FIG. 9 is a flowchart showing a program executed by the control device of FIG. 1;
FIG. 10 is a diagram showing temporal changes in the handle angle and the estimated handle angle.
FIG. 11 is a diagram showing a temporal change between the yaw rate of the vehicle and the actual yaw rate calculated from the corrected steering wheel angle according to the prior art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Engine, 11 ... Propeller shaft, 12 ... Differential apparatus, 13, 14 ... Left and right rear axle shaft, 15 ... Steering wheel (handle), 16 ... Steering shaft, 17 ... Steering mechanism, 18 ... Tie rod, 20 ... For vehicles Brake device, 21 ... Brake pedal, 22 ... Master cylinder, 23 ... Brake pressure adjusting unit, 24 ... Brake control device, 25, 26, 27, 28 ... Each wheel cylinder, 30 ... Control device 30, 31 ... Steering angle sensor, Sfl, Sfr, Srl, Srr ... wheel speed sensor, 32 ... yaw rate sensor, M ... vehicle, Wfl, Wfr, Wrl, Wrr ... left and right front and rear wheels.

Claims (13)

A steering wheel angle calculating means for calculating a steering wheel angle of the vehicle;
The turning angle of the steering wheel of the vehicle steered by the operation of the steering wheel of the vehicle, the steering wheel angle calculated by the steering wheel angle calculating means, the steering wheel angle by the low rigidity in the rotational direction of the steering wheel of the vehicle, and the steering wheel Steering wheel cutting angle deriving means for correcting and deriving based on the deviation from the cutting angle of
A vehicle attitude control device comprising first attitude control means for controlling the attitude of the vehicle based on the steering wheel turning angle derived by the steering wheel turning angle deriving means. An actual yaw rate detecting means for detecting an actual yaw rate of the vehicle;
A steering wheel angle calculating means for calculating a steering wheel angle of the vehicle;
The turning angle of the steering wheel of the vehicle steered by the operation of the steering wheel of the vehicle, the steering wheel angle calculated by the steering wheel angle calculating means, the steering wheel angle by the low rigidity in the rotational direction of the steering wheel of the vehicle, and the steering wheel Steering wheel cutting angle deriving means for correcting and deriving based on the deviation from the cutting angle of
Target yaw rate calculating means for calculating a target yaw rate of the vehicle based on the steering wheel turning angle derived by the steering wheel turning angle deriving means;
A yaw rate difference calculating means for calculating a yaw rate difference by subtracting the actual yaw rate detected by the actual yaw rate detecting means and the target yaw rate calculated by the target yaw rate calculating means;
A vehicle attitude control device comprising second attitude control means for controlling the attitude of the vehicle based on the yaw rate difference calculated by the yaw rate difference calculation means. The steering wheel turning angle deriving means according to claim 1 or 2, wherein the steering wheel cutting angle deriving means corrects the steering wheel angle based on the deviation,
A corrected handle angle deriving unit for deriving a corrected handle angle by correcting the handle angle calculated by the handle angle calculating unit based on the first map or the first arithmetic expression;
An attitude control apparatus for a vehicle, characterized in that the steering wheel turning angle is derived from the correction handle angle derived by the correction handle angle deriving means. In Claim 1 or Claim 2, the steering wheel turning angle deriving means includes a second map or a second arithmetic expression indicating a relationship between the steering wheel angle and the turning angle of the steering wheel,
The turning angle of the steered wheel steered by the operation of the steering wheel of the vehicle is derived by correcting the steering wheel angle calculated by the steering wheel angle calculating means based on the second map or the second arithmetic expression. A vehicle attitude control device. In Claim 3, Steering wheel turning angle estimating means for estimating the turning angle of the steering wheel based on the behavior state of the vehicle,
Estimated steering wheel angle deriving means for deriving an estimated steering wheel angle corresponding to the steering wheel cutting angle estimated by the steering wheel cutting angle estimation means;
Deviation detection means for detecting the presence and degree of the deviation based on the handle angle calculated by the handle angle calculation means and the estimated handle angle derived by the estimated handle angle derivation means;
A plurality of the first maps or first arithmetic expressions respectively corresponding to a plurality of different deviations;
Selecting means for selecting a first map or a first arithmetic expression suitable for the deviation detected by the deviation detecting means from the plurality of first maps or first arithmetic expressions;
The steering wheel turning angle deriving means derives the steering wheel turning angle based on the first map or the first arithmetic expression selected by the selection means. In Claim 4, Steering wheel turning angle estimating means for estimating the turning angle of the steering wheel based on the behavior state of the vehicle,
Estimated steering wheel angle deriving means for deriving an estimated steering wheel angle corresponding to the steering wheel cutting angle estimated by the steering wheel cutting angle estimation means;
Deviation detection means for detecting the presence and degree of the deviation based on the handle angle calculated by the handle angle calculation means and the estimated handle angle derived by the estimated handle angle derivation means;
A plurality of second maps or second arithmetic expressions respectively corresponding to a plurality of different deviations;
Selecting means for selecting a second map or a second arithmetic expression suitable for the deviation detected by the deviation detecting means from the plurality of second maps or second arithmetic expressions;
The steering wheel turning angle deriving unit derives the steering wheel turning angle based on the second map or the second arithmetic expression selected by the selection unit. 4. The vehicle according to claim 3, wherein the first map or the first arithmetic expression suitable for a deviation for each vehicle generated between the steering wheel angle and the steering wheel turning angle is provided in advance, A vehicle attitude control device that derives a turning angle of a steered wheel based on one map or a first arithmetic expression. 5. The steering wheel turning angle deriving means according to claim 4, wherein the steering wheel turning angle deriving means is provided in advance with the second map or the second arithmetic expression suitable for a deviation for each vehicle generated between the steering wheel angle and the turning angle of the steering wheel. A vehicle attitude control device that derives a turning angle of a steered wheel based on two maps or a second arithmetic expression. 8. The vehicle attitude control device according to claim 3, wherein the first map or the first arithmetic expression includes a hysteresis with respect to a rotation direction of a handle of the vehicle. 9. The vehicle attitude control device according to claim 4, wherein the second map or the second arithmetic expression includes a hysteresis with respect to a rotation direction of the steering wheel of the vehicle. In Claim 3, Claim 5 and Claim 7, the first map or the first arithmetic expression is configured to cancel a deviation between a steering angle of the vehicle and an actual turning angle of the steered wheel. A vehicle attitude control device. In Claim 4, Claim 6, and Claim 8, the second map or the second arithmetic expression is configured to cancel a deviation between a steering angle of the vehicle and an actual turning angle of the steered wheel. A vehicle attitude control device. 13. The posture control means according to claim 1, wherein the posture control means controls a posture of the vehicle in a yawing direction and / or a rolling direction by controlling a braking force of a wheel or / and an output of the engine. A vehicle attitude control device.

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