JP3783621B2 - Automatic steering device for vehicles - Google Patents

Description

【００４９】
また左右前輪の転舵角度θwとロアステアリングシャフト２２Ｂの回転角度θdとの間には下記の式８の関係があるので、左右前輪の目標転舵角度θwrに対応するロアステアリングシャフト２２Ｂの目標回転角度θdrは下記の式９により演算され、またステアリングホイール１４の目標回転角度θsrは上記式３に対応する下記の式１０により演算される。
【００５０】
θw＝Ｒθd ……（８）
θdr＝θwr／Ｒ ……（９）
θsr＝（１−αr）θdr ……（１０）
【００５１】
ロアステアリングシャフト２２Ｂをその目標回転角度θdr回転させるために必要な時間ｔ1は下記の式１１により表わされ、ステアリングホイール１４を目標回転角度θdrに対応する目標回転角度θsr回転させるために必要な時間ｔ2は下記の式１２により表わされる。
【００５２】

【００５３】
従ってｔ2＞ｔ1であるときには、左右前輪の転舵が完了しロアステアリングシャフト２２Ｂがその目標回転角度θdr回転した時点に於いてもステアリングホイール１４は目標回転角度θsrの回転を完了していない状況になるので、その場合には左右前輪の転舵が完了した時点以降にもステアリングホイール１４の回転角度θsが目標回転角度θsrになるまで上記式７により求められる回転角速度にてギヤ比可変装置２６によりロアステアリングシャフト２２Ｂに対し相対的にアッパステアリングシャフト２２Ａを回転させれば、左右前輪の転舵が完了した時点よりステアリングホイール１４の回転角度θsが目標回転角度θsrになる時点までの間に於いてもステアリングホイール１４の回転角速度θsdをその目標回転角速度θsdrに制御することができ、これにより左右前輪の転舵が完了する時点の前後に於いてステアリングホイール１４の回転角速度が急変することを確実に防止することができる。
【００５４】
次に図２に示されたフローチャートを参照して図示の第一の実施形態に於ける自動操舵制御について説明する。尚図２に示されたフローチャートによる制御は図には示されていないイグニッションスイッチの閉成により開始され、所定の時間毎に繰返し実行される。
【００５５】
まずステップ１０に於いては操舵角θsを示す信号等の読み込みが行われ、ステップ２０に於いては駐車アシストスイッチ４４がオン状態にあるか否かの判別が行われ、否定判別が行われたときにはステップ２１０へ進み、肯定判別が行われたときにはステップ３０へ進む。
【００５６】
ステップ３０に於いては駐車アシストスイッチ４４がオンに切り替えられた後の最初の駐車アシスト制御であるか否かの判別が行われ、肯定判別が行われたときにはそのままステップ５０へ進み、否定判別が行われたときにはステップ４０へ進む。
【００５７】
ステップ４０に於いては運転者によりステアリングホイール１４の回転速度設定ダイヤル４６が操作されることによりステアリングホイール１４の目標回転速度θsdrの設定が変更されたか否かの判別が行われ、否定判別が行われたときにはそのままステップ１３０へ進み、肯定判別が行われたときにはステップ５０に於いて上記式６に従って比の目標値αrが演算される。
【００５８】
ステップ１３０に於いては駐車アシストを実行するための左右前輪の目標転舵角度θwrが演算され、ステップ１４０に於いてはそれぞれ上記式９及び１０に従ってロアステアリングシャフト２２Ｂの目標回転角度θdr及びステアリングホイール１４の目標回転角度θsrが演算される。
【００５９】
ステップ１５０に於いてはロアステアリングシャフト２２Ｂの目標回転角度θdrとロアステアリングシャフト２２Ｂの実際の回転角度θdとの偏差の絶対値が基準値θdo（微小な正の定数）を越えているか否かの判別が行われ、否定判別、即ち左右前輪の転舵角度θwが実質的に目標転舵角度θwrになった旨の判別が行われたときにはステップ１９０へ進み、肯定判別、即ち左右前輪の転舵制御が必要である旨の判別が行われたときにはステップ１６０へ進む。
【００６０】
ステップ１６０に於いてはロアステアリングシャフト２２Ｂが回転速度Ｂにて回転されるよう電動式パワーステアリング装置１６が制御され、ステップ１７０に於いてはロアステアリングシャフト２２Ｂに対しアッパステアリングシャフト２２Ａが（１−αr）Ｂの回転速度にて相対的に回転されるようギヤ比可変装置２６が制御され、ステップ１８０に於いては必要に応じてエンジン制御装置５０及び制動制御装置５２へ制御信号が出力される。
【００６１】
ステップ１９０に於いてはステアリングホイール１４の目標回転角度θsrとステアリングホイール１４の実際の回転角度θsとの偏差の絶対値が基準値θso（微小な正の定数）を越えているか否かの判別が行われ、否定判別、即ちステアリングホイール１４の回転角度θsが実質的にその目標回転角度θsrに到達している旨の判別が行われたときにはそのまま図２に示されルーチンによる制御を終了し、肯定判別、即ちステアリングホイール１４の回転制御が必要である旨の判別が行われたときにはステップ２００に於いてアッパステアリングシャフト２２ＡがαrＢの回転速度にて回転するようギヤ比可変装置２６が制御される。
【００６２】
ステップ２１０に於ては操舵トルクＴに基き図３に示されたグラフに対応するマップより基本アシストトルクＴabが演算され、ステップ２２０に於ては車速Ｖに基づき図４に示されたグラフに対応するマップより車速係数Ｋvが演算され、ステップ２３０に於ては車速係数Ｋvと基本アシストトルクＴabとの積としてアシストトルクＴaが演算され、ステップ２４０に於てはアシストトルクＴaに対応する制御信号がモータ３２へ出力され、これにより運転者に必要な操舵力を軽減するパワーアシストが実行される。
【００６３】
かくして図示の第一の実施形態によれば、駐車アシストスイッチ４４がオフ状態にあるときには、即ち車輌の通常走行時の如く運転者が自動操舵による駐車アシストを希望していないときには、ステップ２０に於いて否定判別が行われ、ステップ２１０〜２４０の操舵アシスト制御が実行されることにより、運転者の操舵操作の負担が軽減される。
【００６４】
これに対し、運転者が自動操舵による駐車アシストを希望し駐車アシストスイッチ４４がオン状態にあるときには、ステップ２０に於いて肯定判別が行われ、ステップ３０以降の自動操舵による駐車アシストの制御が実行され、左右前輪が自動的に操舵され車輌の駆動力若しくは制動力が自動的に制御されることにより車輌が所定の駐車スペースへ自動的に誘導され停止される。
【００６５】
この場合、ステップ３０〜５０に於いて運転者により操作される回転速度設定ダイヤル４６により設定されたステアリングホイール１４の目標回転角速度θsdrに応じて比の目標値αrが演算され、ステップ１２０に於いて駐車アシストを実行するための左右前輪の目標転舵角度θwrが演算され、ステップ１３０に於いて目標転舵角度θwrに基づきロアステアリングシャフト２２Ｂの回転角度θdr及びステアリングホイール１４の目標回転角度θsrが演算される。
【００６６】
そしてステップ１５０に於いて否定判別が行われるまで、即ち左右前輪の転舵角度θwが実質的に目標転舵角度θwrになって左右前輪の転舵が完了するまで、ステップ１６０に於いて電動式パワーステアリング装置１６によりロアステアリングシャフト２２Ｂが回転速度Ｂにて回転駆動されることにより左右前輪が操舵され、ステップ１７０に於いてギヤ比可変装置２６によりアッパステアリングシャフト２２Ａがロアステアリングシャフト２２Ｂに対し相対的に（１−αr）Ｂの回転速度にて回転駆動され、これによりステアリングホイール１４が目標回転角度θsrにて左右前輪の転舵方向へ回転駆動される。
【００６７】
従って駐車アシストの自動操舵時にはステアリングホイール１４は運転者が回転速度設定ダイヤル４６を操作することにより設定された目標回転角速度θsdrにて左右前輪の転舵方向へ回転駆動されるので、駐車アシスト時にステアリングホイール１４が不自然な回転角速度にて回転すること及びこれに起因して運転者が違和感を感じることを確実に防止することができる。
【００６８】
特に図示の第一の実施形態によれば、左右前輪の転舵角度θwが実質的に目標転舵角度θwrになって左右前輪の転舵が完了してもステアリングホイール１４の回転角度θsがその目標回転角度θsrに到達していないときには、ステップ１５０に於いて否定判別が行われるがステップ１９０に於いて肯定判別が行なわれ、ステップ２００に於いてギヤ比可変装置２６によりアッパステアリングシャフト２２Ａがロアステアリングシャフト２２Ｂに対し相対的にαrＢの回転速度にて回転駆動され、これによりステアリングホイール１４が目標回転角度θsrにて左右前輪の転舵方向へ回転駆動される。
【００６９】
従ってステアリングホイール１４の回転角度θsが左右前輪の切れ角θwに対応しなくなること及びこれに起因してその後の運転者による操舵に悪影響が生じることを確実に防止することができると共に、自動操舵による左右前輪の転舵が完了した直後にステアリングホイール１４の回転角度が急変すること及びこれに起因して運転者が違和感を感じることを確実に防止することができる。
【００７０】
第二の実施形態
図５はギヤ比可変装置及び電動式パワーステアリング装置を備えた車輌に適用されレーンキープの自動操舵を行うよう構成された車輌に適用された本発明による車輌用自動操舵装置の第二の実施形態を示す概略構成図である。尚図５に於いて図１に示された部材と同一の部材には図１に於いて付された符号と同一の符号が付されている。
【００７１】
この第二の実施形態に於いては、電子制御装置４０には操舵角センサ３４よりの操舵角θsを示す信号、トルクセンサ３６よりの操舵トルクＴを示す信号、操舵角センサ３８よりの実操舵角θdを示す信号に加えて、運転者により操作されるレーンキープスイッチ（ＳＷ）５４より該レーンキープスイッチがオン状態にあるか否かを示す信号、運転者により操作される学習スイッチ（ＳＷ）５６より該学習スイッチがオン状態にあるか否かを示す信号、車輌の前方を撮影するビデオカメラ５８より撮影された映像を示す信号も入力される。
【００７２】
電子制御装置４０はレーンキープスイッチ５４がオフ状態にあり運転者によりる通常の操舵操作が行われるときには、上述の第一の実施形態の場合と同様の要領にて操舵アシストを行い、レーンキープスイッチ５４がオン状態にあるときには、車輌を走行路に沿って走行させるレーンキープの自動操舵を行う。
【００７３】
特に電子制御装置４０はレーンキープの自動操舵時には車速Ｖ及びビデオカメラ５８よりの映像信号に基づき、当技術分野に於いて公知の要領にて車輌を走行路に沿って走行させるための左右前輪の目標転舵角度θwrを演算し、目標転舵角度θwrに基づきロアステアリングシャフト２２Ｂの目標回転角度θdr及びステアリングホイール１４の目標回転角度θsrを演算し、ロアステアリングシャフト２２Ｂの回転角度θdが目標回転角度θdrになるよう電動式パワーステアリング装置１６を制御すると共に、必要に応じてエンジン制御装置５０及び制動制御装置５２へ制御信号を出力することによりエンジン出力及び制動力を制御し、これにより車輌を走行路に沿って走行させる。
【００７４】
また電子制御装置４０はレーンキープの自動操舵時には、上述の第一の実施形態に於ける駐車アシストの自動操舵の場合と同様にステアリングホイール１４の回転角速度θsdを目標回転角速度θsdrに制御し、特に自動操舵時に於ける電動式パワーステアリング装置１６によるロアステアリングシャフト２２Ｂの回転角速度Ｂの絶対値が車速Ｖが高いほど小さくなるよう回転角速度Ｂを車速Ｖに応じて可変設定する。
【００７５】
更に電子制御装置４０は学習スイッチ５６がオン状態にある状況にて運転者により操舵操作が行われる際に於ける操舵速度θsdを演算し、例えば２０km／h毎の車速区間毎に操舵速度θsdの最大値をｎ（正の一定の整数）個記憶し、各車速区間毎にｎ個の操舵速度θsdの最大値の平均値を演算し、それらの値を各車速区間毎のステアリングホイール１４の目標回転角速度θsdrとする。
【００７６】
次に図示の第二の実施形態に於いて、上述の如くロアステアリングシャフト２２Ｂの回転角度θdに対する相対回転角度θvの比が上記比の目標値αrになるようギヤ比可変装置２６を制御することによりロアステアリングシャフト２２Ｂに対し相対的にアッパステアリングシャフト２２Ａを回転させ、これによりレーンキープ制御時に於けるステアリングホイール１４の回転角速度θsdを目標回転角速度θsdrに制御する際の作動の概要を説明する。
【００７７】
（１）自動操舵による左右前輪の切り増しや切り戻しがない場合
左右前輪の実際の転舵角度θwが目標転舵角度θwrに到達し、これに伴うステアリングホイール１４の回転が終了するまで自動操舵による左右前輪の切り増しや切り戻しがない場合に於ける左右前輪の転舵制御及びステアリングホイールの回転制御は上述の駐車アシストの場合と同一である。
【００７８】
（２）ステアリングホイールが目標回転位置に到達する前に左右前輪が切り増しされる場合
２−１．左右前輪の実際の転舵角度θwが目標転舵角度θwrに到達しておらず、ステアリングホイール１４の回転角度θsも目標回転角度θsrに到達していない場合（θdd≠０の場合）
この場合には左右前輪の目標転舵角度θwrの大きさが増大され左右前輪の転舵の終了が時間的に遅れるだけであるので、これに対応してステアリングホイール１４の目標回転角度θsrの大きさも増大するだけであり、ギヤ比可変装置２６に対する制御を変更する必要はない。
【００７９】
２−２．左右前輪の実際の転舵角度θwが目標転舵角度θwrに到達した後の場合（θdd＝０の場合）
この場合は左右前輪は転舵されておらず、ステアリングホイール１４のみがギヤ比可変装置２６の電気モータによって回転されている状況である。切り増しによる左右前輪の転舵角度増大量についてギヤ比可変装置２６の制御を変更する必要はなく、ただ単に左右前輪の転舵角度増大量に対応する増加補正量がそのままステアリングホイール１４の目標回転角度θsrに加算されるだけでよい。
【００８０】
（３）ステアリングホイールが目標回転位置に到達する前に左右前輪が切り戻される場合
３−Ａ．左右前輪の現在の転舵位置が左右前輪の現在の目標転舵位置と新たな目標転舵位置との間にない場合
左右前輪が現在の目標転舵位置へ向けて転舵されている状況であるので、左右前輪の目標転舵位置が切り戻し方向に変更されても車体のロールや車輌の横加速度が逆方向になることはなく、ただ単に左右前輪の目標転舵角度の大きさが元々小さかった場合とほぼ同様である。
【００８１】
３−Ａ−１．左右前輪の実際の転舵角度θwが目標転舵角度θwrに到達しておらず、ステアリングホイール１４の回転角度θsも目標回転角度θsrに到達していない場合（θdd≠０の場合）
この場合は左右前輪の目標転舵角度の大きさが低減され、これに対応してステアリングホイール１４の目標回転角度θsrの大きさも低減されることと等価な場合であるので、左右前輪の転舵も早く終了し、ギヤ比可変装置２６の制御を変更する必要もない。
【００８２】
３−Ａ−２．左右前輪の実際の転舵角度θwが目標転舵角度θwrに到達した後の場合（θdd＝０の場合）
この場合は左右前輪は転舵されておらず、ステアリングホイール１４のみがギヤ比可変装置２６の電気モータによって回転されている状況である。切り戻しによる左右前輪の転舵角度減少量についてギヤ比可変装置２６の制御を変更する必要はなく、ただ単にステアリングホイール１４の目標回転角度θsrの大きさが左右前輪の転舵角度減少量に対応する量低減されるだけでよく、またその方が運転者にとって車輌の挙動が解り易い。
【００８３】
３−Ｂ．左右前輪の現在の転舵位置が左右前輪の現在の目標転舵位置と新たな目標転舵位置との間にある場合
３−Ｂ−１．ステアリングホイールの現在の回転位置が現在の目標回転位置と新たな目標回転位置との間にない場合
３−Ｂ−１−１．左右前輪の実際の転舵角度θwが目標転舵角度θwrに到達しておらず、ステアリングホイール１４の回転角度θsも目標回転角度θsrに到達していない場合（θdd≠０の場合）
この場合には左右前輪の転舵方向が逆転するので、まず左右前輪の転舵位置が新たな目標転舵位置に到達するまでギヤ比可変装置２６によりアッパステアリングシャフト２２Ａをロアステアリングシャフト２２Ｂに対し相対的に回転させることによりステアリングホイール１４を静止状態に維持し、しかる後ステアリングホイール１４をギヤ比可変装置２６により新たな目標回転位置まで所定の回転角速度にて回転させる。
【００８４】
上記式１より下記の式１３が成立し、従って下記の式１４が成立する。相対回転角速度θvd、即ち上記所定の回転角速度を上記式７に従って（θdd−θsdr）に設定すると、下記の式１５の通りステアリングホイール１４の回転角速度θsdは目標回転角速度θsdrになる。
【００８５】

【００８６】
尚この場合にはステアリングホイール１４の新たな目標回転角度位置は現在の回転角度位置に対し切り増し方向にあるため、ステアリングホイール１４の回転方向は左右前輪の転舵方向とは逆方向になる。しかし制御サイクルの周期は一般に非常に小さく、またレーンキープ制御時に於ける切り戻し量は一般に小さいので、ステアリングホイール１４の回転方向が左右前輪の転舵方向とは逆方向になることに起因して運転者が違和感を感じることはない。
【００８７】
３−Ｂ−１−２．左右前輪の実際の転舵角度θwが目標転舵角度θwrに到達した後の場合（θdd＝０の場合）
この場合にはステアリングホイール１４が切り戻し方向に回転した後切り増し方向へ回転しないよう、上記３−Ｂ−１−１の場合と同様に、まず左右前輪の転舵位置が新たな目標転舵位置に到達するまでギヤ比可変装置２６によりステアリングホイール１４を静止状態に維持し、しかる後ステアリングホイール１４をギヤ比可変装置２６により新たな目標回転位置まで所定の回転角速度にて回転させる。
【００８８】
３−Ｂ−２．左右前輪の現在の回転位置が現在の目標回転位置と新たな目標回転位置との間にある場合
この場合の制御も上記３−Ｂ−１の場合と同様でよい。但しこの場合にはステアリングホイール１４の新たな目標回転位置は現在の目標回転位置に対し切り戻し方向に位置するので、ギヤ比可変装置２６によるステアリングホイール１４の回転方向は左右前輪の転舵方向と同一の方向になる。
【００８９】
以上の考察より解る如く、左右前輪の目標転舵角度の変化に拘わらず、左右前輪の転舵角度θwが目標転舵角度θwrになるようロアステアリングシャフト２２Ｂの回転角度θdがその目標回転角度θdrになるまで電動式パワーステアリング１６により回転角速度θdd＝Ｂにてロアステアリングシャフト２２Ｂを回転駆動し、ステアリングホイール１４の回転角度θsが目標回転角度θsrになるまでギヤ比可変装置２６によりロアステアリングシャフト２２Ｂに対し相対的にアッパステアリングシャフト２２Ａを回転角速度αrＢにて回転させれば、ステアリングホイール１４の回転角速度を目標回転角速度θsdrに制御することができると共に、左右前輪の切れ角に対するステアリングホイール１４の回転角度のずれ、即ち所謂中点ずれを防止し得ることが解る。
【００９０】
また左右前輪の転舵が完了しロアステアリングシャフト２２Ｂの回転角度θdがその目標回転角度θdrになった時点に於いてもステアリングホイール１４の回転角度θsが目標回転角度θsrになっていない場合には、ロアステアリングシャフト２２Ｂを回転させることなくギヤ比可変装置２６によりロアステアリングシャフト２２Ｂに対し相対的にアッパステアリングシャフト２２Ａを回転角速度αrＢにて回転させれば、ステアリングホイール１４の回転角速度を変化させることなくステアリングホイール１４の中点ずれを防止し得ることが解る。
【００９１】
次に図６に示されたフローチャートを参照して図示の第二の実施形態に於ける自動操舵制御について説明する。尚図６に於いて図２に示されたステップと同一のステップには図２に於いて付されたステップ番号と同一のステップ番号が付されている。また図６に示されたフローチャートによる制御も図には示されていないイグニッションスイッチの閉成により開始され、所定の時間毎に繰返し実行される。
【００９２】
まずステップ１０に於いては操舵角θsを示す信号等の読み込みが行われ、ステップ６０に於いては学習スイッチ５６がオン状態にあるか否かの判別が行われ、否定判別が行われたときにはそのままステップ９０へ進み、肯定判別が行われたときにはステップ７０へ進む。
【００９３】
ステップ７０に於いては各車速区間について運転者による操舵速度の学習値としてステアリングホイール１４の回転角速度の平均値の演算が完了しているか否かの判別が行われ、肯定判別が行われたときにはステップ１００へ進み、否定判別が行われたときにはステップ８０へ進む。
【００９４】
ステップ８０に於いては車速Ｖに基づき車速区間が判定されると共に、前述の要領にて当該車速区間について運転者による操舵速度の学習値としてステアリングホイール１４の回転角速度の平均値が演算されＲＡＭの如き記憶手段に記憶され、ステップ９０に於いては比の目標値αrがそのデフォルト値αo（０より大きく１より小さい正の定数）に設定される。
【００９５】
ステップ１００に於いては車速Ｖが高いほど自動操舵のためのロアステアリングシャフト２２Ｂの回転角速度Ｂの絶対値が小さくなるよう、車速Ｖに基づきロアステアリングシャフト２２Ｂの回転角速度Ｂが演算される。
【００９６】
ステップ１１０に於いては車速Ｖに基づき車速Ｖが属する車速区間が特定されると共に、その特定された車速区間について記憶されている目標回転角速度θsdr及びロアステアリングシャフト２２Ｂの回転角速度Ｂに基づき上記式６に従って比の目標値αrが演算される。
【００９７】
ステップ１２０に於いてはレーンキープスイッチ５４がオン状態にあるか否かの判別が行われ、否定判別が行われたときには上述の第一の実施形態の場合と同様の要領にてステップ２１０〜２４０が実行され、肯定判別が行われたときにはステップ１３０に於いてレーンキープ、即ち車輌を走行路に沿って走行させるに必要な左右前輪の目標転舵角度θwrが演算され、しかる後上述の第一の実施形態の場合と同様にステップ１４０〜２００が実行される。
【００９８】
かくしてこの第二の実施形態によれば、学習スイッチ５６がオフ状態にあるときにはステップ９０に於いて比の目標値αrがデフォルト値αoに設定されるが、学習スイッチ５６がオン状態にあるときには操舵速度の学習が終了するまで運転者の操舵操作時に於けるステアリングホイールの代表的な回転角速度が学習値として演算される。そしてステップ１００に於いて車速Ｖに応じて自動操舵時に於ける最適のロアステアリングシャフト２２Ｂの回転角速度Ｂが演算され、ステップ１１０に於いて回転角速度Ｂ及び学習値として記憶されているステアリングホイールの目標回転角速度θsdrに基づき比の目標値αrが演算される。
【００９９】
従ってこの第二の実施形態によれば、レーンキープの自動操舵時にも運転者の通常の操舵操作時に於ける運転者の操舵速度に対応する回転角速度にてステアリングホイール１４を回転させることができ、これによりレーンキープの自動操舵時にステアリングホイール１４が不自然な回転角速度にて回転すること及びこれに起因して運転者が違和感を感じることを確実に防止することができる。
【０１００】
またこの第二の実施形態に於いても、左右前輪の転舵角度θwが実質的に目標転舵角度θwrになって左右前輪の転舵が完了してもステアリングホイール１４の回転角度θsがその目標回転角度θsrに到達していないときには、ステップ１５０に於いて否定判別が行われるがステップ１９０に於いて肯定判別が行われ、ステップ２００に於いてギヤ比可変装置２６によりアッパステアリングシャフト２２Ａがロアステアリングシャフト２２Ｂに対し相対的にαrＢの回転速度にて回転駆動され、これによりステアリングホイール１４が目標回転角度θsrにて回転駆動される。
【０１０１】
従ってステアリングホイール１４の回転角度θsが左右前輪の切れ角θwに対応しなくなること及びこれに起因してその後の運転者による操舵に悪影響が生じることを確実に防止することができると共に、自動操舵による左右前輪の転舵が完了した直後にステアリングホイール１４の回転角度が急変すること及びこれに起因して運転者が違和感を感じることを確実に防止することができる。
【０１０２】
また図示の第二の実施形態によれば、ステップ１００に於いて車速Ｖに応じて自動操舵時に於ける最適のロアステアリングシャフト２２Ｂの回転角速度Ｂが演算され、ステップ１１０に於いて車速Ｖに基づき目標回転角速度θsdrが決定されると共に目標回転角速度θsdr及びロアステアリングシャフト２２Ｂの回転角速度Ｂに基づき比の目標値αrが演算されるので、レーンキープ制御のための左右前輪の転舵速度を車速に応じて最適な速度に制御することができ、これにより自動操舵時に於けるロアステアリングシャフト２２Ｂの回転角速度Ｂが一定である場合に比して車速に拘わらずレーンキープ制御を最適に実施することができ、また回転角速度Ｂの変動に拘わらずレーンキープ制御時に於けるステアリングホイール１４の回転角速度を確実に目標回転角度θsrに制御することがてきる。
【０１０３】
以上に於いては本発明を特定の実施形態について詳細に説明したが、本発明は上述の実施形態に限定されるものではなく、本発明の範囲内にて他の種々の実施形態が可能であることは当業者にとって明らかであろう。
【０１０４】
例えばロアステアリングシャフト２２Ｂの回転角速度Ｂは上述の第一の実施形態に於いては一定であり、上述の第二の実施形態に於いては車速Ｖに応じて可変設定されるようになっているが、第一の実施形態に於いても回転角速度Ｂが車速Ｖに応じて可変設定されてもよく、また左右前輪の転舵角度θwが目標転舵角度θwrになる直前に漸次低下するよう修正されてもよい。
【０１０５】
また上述の各実施形態に於いては、自動操舵は駐車アシスト制御又はレーンキープ制御の自動操舵であり、左右前輪の目標転舵角度は駐車アシスト制御又はレーンキープ制御を達成するための目標転舵角度であるが、自動操舵は例えば車輌前方の障害物を回避するための自動操舵や車輌の挙動を安定化させるための自動操舵の如く当技術分野に於いて公知の任意の目的の自動操舵であってよい。
【０１０６】
また上述の第二の実施形態に於いては、運転者の操舵操作時の操舵速度の学習は各車速区間毎にｎ個最大操舵速度の平均値として演算されるようになっているが、例えば車速Ｖが高いほど小さくなるよう基準値を演算すると共に大きさが該基準値以上の操舵角速度の最大値について平均値が演算されてもよく、また各車速区間毎に基準値以上のｍ（正の一定の整数）個の操舵角速度の正規分布を求め、その正規分布の最大個数に対応する操舵速度が学習値として演算されてもよく、更には運転者の操舵操作時の操舵速度を示す値である限り、任意の態様にて演算されてよいものである。
【図面の簡単な説明】
【図１】ギヤ比可変装置及び電動式パワーステアリング装置を備えた車輌に適用され駐車アシストの自動操舵を行うよう構成された本発明による車輌用自動操舵装置の第一の実施形態を示す概略構成図である。
【図２】第一の実施形態に於ける自動操舵制御ルーチンを示すフローチャートである。
【図３】操舵トルクＴと基本アシスト量Ｔabとの間の関係を示すグラフである。
【図４】車速Ｖと車速係数Ｋvとの間の関係を示すグラフである。
【図５】ギヤ比可変装置及び電動式パワーステアリング装置を備えた車輌に適用されレーンキープの自動操舵を行うよう構成された車輌に適用された本発明による車輌用自動操舵装置の第二の実施形態を示す概略構成図である。
【図６】第二の実施形態に於ける自動操舵制御ルーチンを示すフローチャートである。
【符号の説明】
１０FR〜１０RL…車輪
１６…電動式パワーステアリング装置
２２…ステアリングシャフト
２２Ａ…アッパステアリングシャフト
２２Ｂ…ロアステアリングシャフト
２６…ギヤ比可変装置
３０…パワーユニット
３４、３８…操舵角センサ
３６…トルクセンサ
４０…電子制御装置
４２…車速センサ
４４…駐車アシストスイッチ
４６…設定ダイヤル
４８…ビデオカメラ
５４…レーンキープスイッチ
５６…学習スイッチ
５８…ビデオカメラ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a steering apparatus for a vehicle such as an automobile, and more particularly to an automatic steering apparatus that automatically steers steering wheels.
[0002]
[Prior art]
For example, as described in Japanese Patent Laid-Open No. 9-66841, steering wheel operation data and vehicle travel data by a driver are stored, and stored steering wheel operation data and vehicle operation data are stored during automatic steering. 2. Description of the Related Art Conventionally, an automatic steering apparatus configured to perform automatic steering by turning a steered wheel with an automatic steering mechanism based on travel data is known. According to this type of automatic steering device, automatic steering is executed according to the operation state of the steering wheel by the driver, so that the driver performs automatic steering in a manner different from his / her own operation state and preference. This can reduce the possibility of feeling uncomfortable.
[0003]
[Problems to be solved by the invention]
In general, in an automatic steering device, when a steered wheel is steered by automatic steering, the steering wheel rotates correspondingly. However, in the above-described conventional automatic steering device, the ratio of the rotational angular speed of the steering wheel to the steering speed of the steered wheel cannot be appropriately set. May feel uncomfortable due to the steering wheel rotating at different rotational angular velocities.
[0004]
The present invention has been made in view of the above-described problems in an automatic steering apparatus configured to perform automatic steering by turning a steered wheel with an automatic steering mechanism, and the main problem of the present invention is By appropriately controlling the ratio of the rotational angular speed of the steering wheel to the steering speed of the steering wheel, the rotational angular speed is different from the rotational angular speed assumed by the driver during automatic steering regardless of the steering speed of the steering wheel. This is to prevent the user from feeling uncomfortable due to the rotation of the steering wheel.
[0005]
[Means for Solving the Problems]
According to the present invention, the main problem described above is the structure of claim 1, that is, the automatic steering means for turning the steering wheel without depending on the steering operation of the driver with respect to the steering wheel, the steering wheel, and the steering. A ratio variable means for changing a ratio of a rotation angle of the steering wheel to a steering angle of the steering wheel provided in a steering system between the steering wheel and a target of the rotation angle of the steering wheel with respect to the steering angle of the steering wheel A target ratio setting means for setting a ratio, a target turning angle of the steered wheel is calculated, the automatic steering means is controlled based on the target steered angle, and the steering wheel rotates with respect to the steered wheel turning angle. And a control means for controlling the ratio variable means so that the angle ratio becomes the target ratio.
[0006]
According to the present invention, in order to effectively achieve the main problem described above, in the configuration of claim 1, the target ratio setting means sets a target rotational angular velocity of the steering wheel and the target The target ratio is configured to be set based on a rotational angular velocity and a turning speed of the steered wheels by the automatic steering means (configuration of claim 2).
[0007]
According to the present invention, in order to effectively achieve the main problem described above, in the configuration of claim 2, the target ratio setting means is a steering speed when the driver rotates the steering wheel. Steering speed storage means for storing the vehicle speed corresponding to the vehicle speed, and the target rotational angular speed is set based on the vehicle speed and the steering speed stored by the steering speed storage means.
[0008]
According to the present invention, in order to effectively achieve the main problems described above, in the configuration of claim 2, the target ratio setting means includes an operation means that is set and operated by a driver. The target rotational angular velocity is set in accordance with the setting of the operating means by (configuration of claim 4).
[0009]
According to the present invention, in order to effectively achieve the above-mentioned main problems, the ratio variable means includes the first steering shaft on the steering wheel side and the steering wheel. Rotation of the steering wheel relative to the steering angle of the steered wheel by rotating the second steering shaft relative to the first steering shaft, provided between the second steering shaft on the wheel side The angle ratio is changed (configuration of claim 5).
[0010]
According to the present invention, in order to effectively achieve the main problems described above, in the configuration of claim 5, the target ratio setting means includes the first and second rotation angles with respect to the rotation angle of the first steering shaft. The target value of the ratio of the relative rotation angle of the second steering shaft is set (configuration of claim 6).
[0011]
According to the present invention, in order to effectively achieve the main problem described above, in the configuration of claim 6, the control means sets the turning angle of the steered wheels to the target turning angle. Calculating a target rotation angle of the first steering shaft, controlling the automatic steering means based on the target rotation angle of the first steering shaft, and controlling the ratio variable means based on the target value of the ratio (Structure of claim 7).
[0012]
According to the present invention, in order to effectively achieve the above main problem, in the configuration of claim 7, the control means is configured to set the target rotation angle and the ratio target of the first steering shaft. Based on the value, the target rotation angle of the second steering shaft is calculated, and after the time when the rotation angle of the first steering shaft reaches the target rotation angle, the rotation angle of the second steering shaft is When the target rotation angle is not reached, the control of the ratio variable means based on the target value of the ratio is continued until the rotation angle of the second steering shaft reaches the target rotation angle. Configuration).
[0013]
[Action and effect of the invention]
According to the configuration of the first aspect, the target ratio setting means sets the target ratio of the rotation angle of the steering wheel with respect to the steering angle of the steering wheel, calculates the target steering angle of the steering wheel, and calculates the target steering angle. And the ratio variable means is controlled so that the ratio of the rotation angle of the steering wheel to the steering angle of the steered wheel becomes the target ratio. The steering wheel can be automatically steered to an angle, and the ratio of the rotation angle of the steering wheel to the steering angle of the steering wheel during the automatic steering is reliably controlled to the target ratio, so that during the automatic steering The ratio of the rotational angular velocity of the steering wheel to the steering angular velocity of the steering wheel can be controlled to the target ratio, and thus the rotational angular velocity assumed by the driver during automatic steering It is possible to reliably prevent the rotating steering wheel at different rotational angular velocity.
[0014]
According to the second aspect of the invention, the target rotation angular speed of the steering wheel is set by the target ratio setting means, and the target ratio is set based on the target rotation angular speed and the turning speed of the steered wheels by the automatic steering means. Therefore, the rotational angular speed of the steering wheel during automatic steering can be reliably controlled to the target rotational angular speed, and the steering wheel rotates at a rotational angular speed different from the rotational angular speed assumed by the driver during automatic steering. It is possible to reliably prevent the driver from feeling uncomfortable due to the fact that
[0015]
According to the third aspect of the present invention, the steering speed when the driver rotates the steering wheel is stored in correspondence with the vehicle speed by the steering speed storage means, and the steering speed stored by the vehicle speed and steering speed storage means is stored. Since the target rotational angular velocity is set based on the above, the rotational angular velocity of the steering wheel at the time of automatic steering can be controlled to the same rotational angular velocity as that at the time of the driver's normal steering operation regardless of the vehicle speed.
[0016]
According to the fourth aspect of the present invention, the target ratio setting means includes the operation means that is set and operated by the driver, and sets the target rotational angular velocity according to the setting of the operation means by the driver. The steering wheel rotational angular velocity can be controlled to a target rotational angular velocity according to the setting of the operating means by the driver.
[0017]
According to the fifth aspect of the present invention, the ratio variable means is provided between the first steering shaft on the steering wheel side and the second steering shaft on the steering wheel side, and is relative to the first steering shaft. Since the ratio of the steering wheel rotation angle to the steering wheel turning angle is changed by rotating the second steering shaft, the ratio of the steering wheel rotation angle to the steering wheel turning angle can be arbitrarily changed. Accordingly, the ratio of the rotational angular velocity of the steering wheel to the steering angular velocity of the steering wheel can be arbitrarily changed regardless of the steering angular velocity of the steering wheel.
[0018]
According to the sixth aspect of the present invention, the target ratio setting means sets the target value of the ratio of the relative rotation angle of the first and second steering shafts to the rotation angle of the first steering shaft. The target ratio of the rotation angle of the steering wheel with respect to the turning angle can be set easily and reliably.
[0019]
According to the seventh aspect of the present invention, the target rotation angle of the first steering shaft for setting the turning angle of the steered wheels to the target turning angle is calculated, and based on the target rotation angle of the first steering shaft. Since the automatic steering means is controlled and the ratio variable means is controlled based on the target value of the ratio, the turning angle of the steered wheels can be ensured by controlling the rotation angle of the first steering shaft to the target rotation angle. The target steering angle can be controlled, and the ratio of the relative rotation angle of the first and second steering shafts to the rotation angle of the first steering shaft can be reliably controlled to the target value of the ratio. it can.
[0020]
According to the configuration of claim 8, the target rotation angle of the second steering shaft is calculated based on the target rotation angle and ratio target value of the first steering shaft, and the rotation angle of the first steering shaft is If the rotation angle of the second steering shaft is not the target rotation angle after the time when the target rotation angle is reached, the target value of the ratio until the rotation angle of the second steering shaft reaches the target rotation angle Since the control of the ratio variable means based on the is continued, even if the automatic steering is completed, if the rotational angle position of the steering wheel does not correspond to the turning angle of the steering wheel, the steering wheel reliably corresponds to the turning angle of the steering wheel It is possible to reliably rotate to the rotation angle position to be rotated, and at that time the steering wheel is rotated during automatic steering. It can be rotated at the same angular velocity as the angular velocity, and after the completion of automatic steering, the rotation angle position of the steering wheel does not correspond to the turning angle of the steering wheel, and the rotation of the steering wheel after completion of automatic steering. It is possible to reliably prevent the driver from feeling uncomfortable due to the unnaturalness of the vehicle.
[0021]
[Preferred embodiment of the problem solving means]
According to one preferred aspect of the present invention, in the configuration of claim 1, the target turning angle of the steered wheel is a target for parking assist control that automatically guides and stops the vehicle in a predetermined parking space. It is comprised so that it may be a steering angle (preferred aspect 1).
[0022]
According to another preferred aspect of the present invention, in the configuration of claim 1, the target turning amount of the steered wheel is the target turning amount for lane keeping control that causes the vehicle to travel along the traveling lane. (Preferred embodiment 2).
[0023]
According to another preferred embodiment of the present invention, in the configuration of the preferred embodiment 1, the turning speed of the steered wheels during automatic steering is configured to be substantially constant (preferred embodiment 3). .
[0024]
According to another preferred aspect of the present invention, in the configuration of the preferred aspect 2, the turning speed of the steered wheels during automatic steering is variably set according to the vehicle speed so as to decrease as the vehicle speed increases. (Preferred aspect 4).
[0025]
According to another preferred aspect of the present invention, in the configuration of claim 3, the steering speed storage means stores the steering speed when the driver rotates the steering wheel for each of a plurality of vehicle speed sections. (Preferred aspect 5)
[0026]
According to another preferred aspect of the present invention, in the configuration of the preferred aspect 5 described above, when the target ratio setting means has not completed the storage of the steering speed for all vehicle speed sections by the steering speed storage means, The target rotational angular velocity is configured to be set to a preset value (preferred aspect 6).
[0027]
According to another preferred aspect of the present invention, in the configuration of claim 5, the ratio variable means includes a rotational drive means for rotating the second steering shaft relative to the first steering shaft. (Preferred embodiment 7).
[0028]
According to another preferred aspect of the present invention, in the configuration of claim 8, after the time when the rotation angle of the first steering shaft reaches the target rotation angle, the second steering shaft The ratio variable means is configured to control the rotational angular velocity to be the same as the rotational angular velocity before the time (preferred aspect 8).
[0029]
According to another preferred aspect of the present invention, in the configuration of claim 1, the automatic steering means is configured to include an electric power steering apparatus (preferred aspect 9).
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
[0031]
First embodiment
FIG. 1 is a schematic configuration diagram showing a first embodiment of an automatic steering device for a vehicle according to the present invention which is applied to a vehicle equipped with a gear ratio variable device and an electric power steering device and is configured to perform automatic parking assist. It is.
[0032]
In FIG. 1, 10FL and 10FR respectively indicate the left and right front wheels of the vehicle 12, and 10RL and 10RR respectively indicate the left and right rear wheels of the vehicle. The left and right front wheels 10FL and 10FR, which are the steering wheels, are driven via a rack bar 18 and tie rods 20L and 20R by a rack-and-pinion type electric power steering device 16 driven in response to an operation of the steering wheel 14 by a driver. Steered.
[0033]
The steering wheel 14 is drivingly connected to a steering gear box 24 by an upper steering shaft 22A and a lower steering shaft 22B, and a gear ratio variable device as a ratio variable means (see FIG. 5) is provided between the upper steering shaft 22A and the lower steering shaft 22B. , Which is abbreviated as VGRS) 26. A power unit 30 is drivingly connected to the lower steering shaft 22B by a gear reduction mechanism 28, and the power unit 30 has an electric motor 32.
[0034]
Thus, the rack-and-pinion type electric power steering device 16, the gear reduction mechanism 28, the power unit 30 and the like cooperate with each other to generate a steering assist torque when the driver steers the left and right front wheels 10FL and 10FR. Assist the driver in steering. Further, the power unit 30 and the like function as automatic steering means for automatically turning the left and right front wheels independently of the steering operation by the driver by generating steering torque and rotating the lower steering shaft 22B during automatic steering.
[0035]
Although not shown in the figure, the gear ratio variable device 26 has a general configuration including an electric motor that rotationally drives the lower steering shaft 22B relative to the upper steering shaft 22A. During the steering operation, the ratio of the rotation angle of the lower steering shaft 22B to the rotation angle of the upper steering shaft 22A (variable gear ratio K) is maintained at 1 so that the upper steering shaft 22A and the lower steering shaft 22B rotate integrally. During automatic steering, the lower steering shaft 22B is positively rotated relative to the upper steering shaft 22A by the electric motor, and the ratio of the rotation angle of the lower steering shaft 22B to the rotation angle of the upper steering shaft 22A is thereby increased. Functions as the ratio changing means for reduction.
[0036]
In the illustrated first embodiment, the upper steering shaft 22A is provided with a steering angle sensor 34 for detecting the rotation angle of the upper steering shaft as the steering angle θs and a torque sensor 36 for detecting the steering torque T. The lower steering shaft 22B is provided with a steering angle sensor 38 that detects the rotation angle of the lower steering shaft as an actual steering angle θd, and outputs from these sensors are supplied to the electronic control unit 40.
[0037]
The electronic control unit 40 also includes a signal indicating the vehicle speed V detected by the vehicle speed sensor 42, a signal indicating whether or not the switch is turned on by a parking assist switch (SW) 44 operated by the driver, A signal indicating the target rotational angular velocity θsdr of the steering wheel 14 and a signal indicating an image captured from the video camera 48 for capturing the rear of the vehicle are also input from the setting dial 46 for setting the target rotational angular velocity θsdr of the steering wheel 14. The
[0038]
Although not shown in detail in FIG. 1, the electronic control unit 40 includes a CPU, a ROM, a RAM, and an input / output port device, which are connected to each other by a bidirectional common bus and a drive circuit. It may be better. The steering angle sensors 34 and 38 and the torque sensor 36 detect the steering angles θs and θa and the steering torque T, respectively, when the vehicle is steered in the left turn direction.
[0039]
As will be described later, when the parking assist switch 44 is in the OFF state and the driver performs a normal steering operation, the electronic control unit 40 maintains the variable gear ratio K of the gear ratio variable device 26 at 1 and the steering torque T. Further, the assist torque Ta is calculated according to the vehicle speed V, and the steering assist for reducing the driver's steering load is performed by controlling the power unit 30 of the electric power steering device 16 based on the assist torque Ta.
[0040]
In addition, when the parking assist switch 44 is in the on state, the electronic control unit 40 automatically moves the vehicle to a predetermined parking space based on the vehicle speed V and the video signal from the video camera 48 in a manner known in the art. To calculate the target turning angle θwr of the lower left and right front wheels, the target rotation angle θdr of the lower steering shaft 22B and the target rotation angle θsr of the steering wheel 14 based on the target turning angle θwr, and the lower steering shaft 22B. The electric power steering device 16 is controlled so that the rotation angle θd of the engine becomes the target rotation angle θdr, and the engine output and braking force are controlled by outputting control signals to the engine control device 50 and the braking control device 52 as necessary. Control, thereby automatically guiding the vehicle to a predetermined parking space and stopping it.
[0041]
In this case, the electronic control unit 40 sets the target rotational angular velocity θsdr of the steering wheel 14 set by the setting dial 46 and the rotational angular velocity B of the lower steering shaft 22B by the electric power steering device 16 during automatic steering (the absolute value is a constant). The target value αr of the ratio is calculated based on the above, the relative rotation angle of the upper steering shaft 22A with respect to the lower steering shaft 22B is θv, and the ratio α of the relative rotation angle θv with respect to the rotation angle θd of the lower steering shaft 22B is the target value of the ratio By controlling the gear ratio variable device 26 so as to be αr, the upper steering shaft 22A is rotated relative to the lower steering shaft 22B, whereby the rotational angular velocity θsd of the steering wheel 14 at the time of parking assist is changed to the target rotational angular velocity θsdr. System I will do it.
[0042]
Further, the electronic control unit 40 determines that the steering wheel 14 is rotated when the rotation angle θs of the steering wheel 14 does not reach the target rotation angle θsr even if the rotation angle θd of the lower steering shaft 22B substantially reaches the target rotation angle θdr. The lower steering shaft is controlled by controlling the gear ratio variable device 26 so that the ratio of the relative rotational angle θv to the rotational angle θd of the lower steering shaft 22B becomes the target value αr of the above ratio until the rotational angle θs reaches the target rotational angle θsr. The relative rotation of the upper steering shaft 22A with respect to 22B is continued, whereby the steering wheel 14 is rotated so that the rotation angle θs of the steering wheel 14 becomes an angle corresponding to the turning angle θw of the left and right front wheels, and the steering wheel at that time The rotation angular velocity θsd of the target rotation angular velocity θs Control dr.
[0043]
Next, in the illustrated first embodiment, the gear ratio variable device 26 is controlled so that the ratio α of the relative rotation angle θv to the rotation angle θd of the lower steering shaft 22B becomes the target value αr of the ratio as described above. Thus, the outline of the operation when the upper steering shaft 22A is rotated relative to the lower steering shaft 22B and thereby the rotational angular velocity θsd of the steering wheel 14 at the parking assist is controlled to the target rotational angular velocity θsdr will be described.
[0044]
Assuming that the gear ratio of the gear box 24 of the electric power steering device 16 is R and the gear ratio K of the gear ratio variable device 26 is 1, the following formulas 1 and 2 hold, so the following formula 3 holds. To do. In this case, as can be seen from Equation 3 below, when the ratio α of the relative rotation angle θv to the rotation angle θd of the lower steering shaft 22B is smaller than 1, the steering wheel 14 rotates in the same direction as the lower steering shaft 22B, and α Is larger than 1, the steering wheel 14 rotates in the opposite direction to the lower steering shaft 22B. When α is 1, the steering wheel 14 does not rotate even when the lower steering shaft 22B rotates, and remains stationary. maintain.
[0045]
θv = θd−θs (1)
α = θv / θd (2)
θs = (1−α) θd (3)
[0046]
Assuming that the rotational angular velocity of the lower steering shaft 22B is θdd, the following formula 4 is established from the above formula 3. Therefore, by controlling the ratio α from the following formula 4, the steering situation of the left and right front wheels that are steered wheels Can independently control the rotational angular velocity of the steering wheel 14, so that the rotational angular velocity of the steering wheel 14 at the time of automatic steering is not uncomfortable for the driver by setting the ratio α to a target value αr of an appropriate ratio. It can be seen that the target rotational angular velocity θsdr can be controlled.
θsd = (1-α) θdd (4)
[0047]
In this case, since the following equation 5 is established from the above equation 4, if the rotational angular velocity θdd of the lower steering shaft 22B during automatic steering is a known value B, the target value αr of the ratio corresponding to the target rotational angular velocity θsdr is It calculates | requires by following formula 6. Further, the rate of change of the relative rotation angle θv during automatic steering, that is, the relative rotation angular velocity θvd of the upper steering shaft 22A and the lower steering shaft 22B is expressed by the following equation 7 from the above equation 1.
[0048]

[0049]
Further, since there is a relationship of the following equation (8) between the steering angle θw of the left and right front wheels and the rotation angle θd of the lower steering shaft 22B, the target rotation of the lower steering shaft 22B corresponding to the target steering angle θwr of the left and right front wheels The angle θdr is calculated by the following equation 9, and the target rotation angle θsr of the steering wheel 14 is calculated by the following equation 10 corresponding to the above equation 3.
[0050]
θw = Rθd (8)
θdr = θwr / R (9)
θsr = (1−αr) θdr (10)
[0051]
The time t1 required to rotate the lower steering shaft 22B by the target rotation angle θdr is expressed by the following equation 11, and the time required to rotate the steering wheel 14 by the target rotation angle θsr corresponding to the target rotation angle θdr. t2 is represented by Equation 12 below.
[0052]

[0053]
Therefore, when t2> t1, the steering wheel 14 does not complete the rotation of the target rotation angle θsr even when the steering of the left and right front wheels is completed and the lower steering shaft 22B rotates the target rotation angle θdr. Therefore, in this case, the gear ratio variable device 26 at the rotational angular speed obtained by the above equation 7 until the rotational angle θs of the steering wheel 14 reaches the target rotational angle θsr even after the steering of the left and right front wheels is completed. If the upper steering shaft 22A is rotated relative to the lower steering shaft 22B, the rotation angle θs of the steering wheel 14 reaches the target rotation angle θsr after the steering of the left and right front wheels is completed. Also, the rotational angular velocity θsd of the steering wheel 14 can be controlled to the target rotational angular velocity θsdr. It is possible to reliably prevent the rotation angular velocity of the steering wheel 14 at around the time the turning of the left and right front wheels is completed suddenly changes by.
[0054]
Next, the automatic steering control in the illustrated first embodiment will be described with reference to the flowchart shown in FIG. The control according to the flowchart shown in FIG. 2 is started by closing an ignition switch not shown in the figure, and is repeatedly executed at predetermined time intervals.
[0055]
First, at step 10, a signal indicating the steering angle θs is read, and at step 20, it is determined whether or not the parking assist switch 44 is in an on state, and a negative determination is made. Sometimes the routine proceeds to step 210, and when an affirmative determination is made, the routine proceeds to step 30.
[0056]
In step 30, it is determined whether or not it is the first parking assist control after the parking assist switch 44 is turned on. If an affirmative determination is made, the process proceeds to step 50 as it is, and a negative determination is made. If so, go to Step 40.
[0057]
In step 40, it is determined whether or not the setting of the target rotational speed θsdr of the steering wheel 14 has been changed by operating the rotational speed setting dial 46 of the steering wheel 14 by the driver, and a negative determination is made. If YES, the process proceeds to step 130. If an affirmative determination is made, the target value αr of the ratio is calculated in step 50 according to the above equation 6.
[0058]
In step 130, the target turning angle θwr of the left and right front wheels for executing the parking assist is calculated. In step 140, the target rotation angle θdr of the lower steering shaft 22B and the steering wheel are calculated according to the above equations 9 and 10, respectively. 14 target rotation angles θsr are calculated.
[0059]
In step 150, whether or not the absolute value of the deviation between the target rotation angle θdr of the lower steering shaft 22B and the actual rotation angle θd of the lower steering shaft 22B exceeds a reference value θdo (a small positive constant). When a determination is made and a negative determination is made, that is, a determination is made that the turning angle θw of the left and right front wheels has substantially reached the target turning angle θwr, the routine proceeds to step 190, where an affirmative determination is made, that is, the turning of the left and right front wheels When it is determined that control is necessary, the routine proceeds to step 160.
[0060]
In step 160, the electric power steering device 16 is controlled so that the lower steering shaft 22B is rotated at the rotational speed B. In step 170, the upper steering shaft 22A is (1-) with respect to the lower steering shaft 22B. αr) The gear ratio variable device 26 is controlled so as to be rotated at a rotational speed of B. In step 180, control signals are output to the engine control device 50 and the brake control device 52 as necessary. .
[0061]
In step 190, it is determined whether or not the absolute value of the deviation between the target rotation angle θsr of the steering wheel 14 and the actual rotation angle θs of the steering wheel 14 exceeds a reference value θso (a minute positive constant). When a negative determination is made, that is, when it is determined that the rotation angle θs of the steering wheel 14 has substantially reached the target rotation angle θsr, the routine control shown in FIG. When it is determined, that is, when it is determined that the rotation control of the steering wheel 14 is necessary, at step 200, the gear ratio variable device 26 is controlled so that the upper steering shaft 22A rotates at the rotational speed of αrB.
[0062]
In step 210, the basic assist torque Tab is calculated from the map corresponding to the graph shown in FIG. 3 on the basis of the steering torque T, and in step 220, it corresponds to the graph shown in FIG. The vehicle speed coefficient Kv is calculated from the map, and in step 230, the assist torque Ta is calculated as the product of the vehicle speed coefficient Kv and the basic assist torque Tab. In step 240, a control signal corresponding to the assist torque Ta is calculated. This is output to the motor 32, thereby executing power assist for reducing the steering force necessary for the driver.
[0063]
Thus, according to the first embodiment shown in the figure, when the parking assist switch 44 is in the OFF state, that is, when the driver does not desire the parking assist by the automatic steering as in the normal driving of the vehicle, in step 20. Thus, a negative determination is made and the steering assist control in steps 210 to 240 is executed, so that the burden of the steering operation on the driver is reduced.
[0064]
On the other hand, when the driver desires parking assist by automatic steering and the parking assist switch 44 is in the ON state, an affirmative determination is made in step 20, and control of parking assist by automatic steering after step 30 is executed. The left and right front wheels are automatically steered and the driving force or braking force of the vehicle is automatically controlled, so that the vehicle is automatically guided to a predetermined parking space and stopped.
[0065]
In this case, the target value αr of the ratio is calculated according to the target rotational angular velocity θsdr of the steering wheel 14 set by the rotational speed setting dial 46 operated by the driver in steps 30 to 50, and in step 120. The target turning angle θwr of the left and right front wheels for executing the parking assist is calculated, and in step 130, the rotation angle θdr of the lower steering shaft 22B and the target rotation angle θsr of the steering wheel 14 are calculated based on the target turning angle θwr. Is done.
[0066]
Then, until a negative determination is made in step 150, that is, until the steering of the left and right front wheels is substantially equal to the target turning angle θwr and the steering of the left and right front wheels is completed, the electric type is operated in step 160. The left and right front wheels are steered when the lower steering shaft 22B is driven to rotate at the rotational speed B by the power steering device 16, and the upper steering shaft 22A is made relative to the lower steering shaft 22B by the gear ratio variable device 26 in step 170. Thus, the wheel is rotated at a rotational speed of (1-αr) B, and the steering wheel 14 is rotated in the steered direction of the left and right front wheels at the target rotation angle θsr.
[0067]
Accordingly, during automatic parking assist steering, the steering wheel 14 is rotationally driven in the steering direction of the left and right front wheels at the target rotational angular speed θsdr set by the driver operating the rotational speed setting dial 46. It is possible to reliably prevent the wheel 14 from rotating at an unnatural rotational angular velocity and the driver from feeling uncomfortable due to this.
[0068]
In particular, according to the first embodiment shown in the drawing, even if the steering angle θw of the left and right front wheels becomes substantially the target steering angle θwr and the steering of the left and right front wheels is completed, the rotation angle θs of the steering wheel 14 is When the target rotational angle θsr has not been reached, a negative determination is made in step 150, but an affirmative determination is made in step 190, and in step 200 the upper steering shaft 22A is lowered by the gear ratio variable device 26. The steering wheel 14 is rotationally driven at a rotational speed of αrB relative to the steering shaft 22B, whereby the steering wheel 14 is rotationally driven in the steering direction of the left and right front wheels at the target rotational angle θsr.
[0069]
Therefore, it is possible to reliably prevent the rotation angle θs of the steering wheel 14 from not corresponding to the turning angle θw of the left and right front wheels and the subsequent adverse effect on the steering by the driver due to this. Immediately after the steering of the left and right front wheels is completed, it is possible to reliably prevent the rotation angle of the steering wheel 14 from changing suddenly and the driver from feeling uncomfortable due to this.
[0070]
Second embodiment
FIG. 5 shows a second embodiment of an automatic steering device for a vehicle according to the present invention applied to a vehicle equipped with a gear ratio variable device and an electric power steering device and configured to perform automatic steering of a lane keep. It is a schematic block diagram which shows. In FIG. 5, the same members as those shown in FIG. 1 are denoted by the same reference numerals as those shown in FIG.
[0071]
In the second embodiment, the electronic control unit 40 has a signal indicating the steering angle θs from the steering angle sensor 34, a signal indicating the steering torque T from the torque sensor 36, and actual steering from the steering angle sensor 38. In addition to a signal indicating the angle θd, a signal indicating whether or not the lane keep switch is in an ON state from a lane keep switch (SW) 54 operated by the driver, a learning switch (SW) operated by the driver A signal indicating whether or not the learning switch is in an ON state and a signal indicating an image captured by the video camera 58 capturing the front of the vehicle are also input from 56.
[0072]
When the lane keep switch 54 is in the OFF state and the normal steering operation is performed by the driver, the electronic control unit 40 performs steering assist in the same manner as in the first embodiment, and the lane keep switch When 54 is in the ON state, the lane keep is automatically steered so that the vehicle travels along the travel path.
[0073]
In particular, the electronic control unit 40 uses the vehicle speed V and the video signal from the video camera 58 during the automatic steering of the lane keep based on the vehicle speed V and the left and right front wheels for driving the vehicle along the road in a manner known in the art. The target turning angle θwr is calculated, the target rotation angle θdr of the lower steering shaft 22B and the target rotation angle θsr of the steering wheel 14 are calculated based on the target turning angle θwr, and the rotation angle θd of the lower steering shaft 22B is the target rotation angle. The electric power steering device 16 is controlled so as to be θdr, and the engine output and braking force are controlled by outputting control signals to the engine control device 50 and the braking control device 52 as necessary, thereby driving the vehicle. Drive along the road.
[0074]
Further, the electronic control unit 40 controls the rotational angular velocity θsd of the steering wheel 14 to the target rotational angular velocity θsdr during automatic lane keeping steering, as in the case of automatic parking assist steering in the first embodiment described above. The rotational angular speed B is variably set according to the vehicle speed V so that the absolute value of the rotational angular speed B of the lower steering shaft 22B by the electric power steering device 16 during automatic steering becomes smaller as the vehicle speed V increases.
[0075]
Further, the electronic control unit 40 calculates a steering speed θsd when the driver performs a steering operation in a state where the learning switch 56 is in the on state, and for example, the steering speed θsd is calculated for each vehicle speed section every 20 km / h. The maximum value is stored in n (a positive constant integer), the average value of the maximum values of the n steering speeds θsd is calculated for each vehicle speed section, and these values are the targets of the steering wheel 14 for each vehicle speed section. The rotational angular velocity is θsdr.
[0076]
Next, in the second embodiment shown in the figure, the gear ratio variable device 26 is controlled so that the ratio of the relative rotation angle θv to the rotation angle θd of the lower steering shaft 22B becomes the target value αr of the ratio as described above. The outline of the operation when the upper steering shaft 22A is rotated relative to the lower steering shaft 22B to control the rotational angular velocity θsd of the steering wheel 14 to the target rotational angular velocity θsdr during the lane keeping control will be described.
[0077]
(1) When the left and right front wheels are not increased or reduced by automatic steering
The left and right front wheels in the case where the actual turning angle θw of the left and right front wheels reaches the target turning angle θwr, and there is no additional turning or turning back of the left and right front wheels by automatic steering until the rotation of the steering wheel 14 is completed. The steering control and the rotation control of the steering wheel are the same as in the parking assist described above.
[0078]
(2) When the left and right front wheels are increased before the steering wheel reaches the target rotational position
2-1. When the actual turning angle θw of the left and right front wheels has not reached the target turning angle θwr, and the rotation angle θs of the steering wheel 14 has not reached the target rotation angle θsr (when θdd ≠ 0)
In this case, since the magnitude of the target turning angle θwr of the left and right front wheels is increased and the end of turning of the left and right front wheels is only delayed in time, the magnitude of the target rotation angle θsr of the steering wheel 14 is correspondingly increased. It only increases, and there is no need to change the control for the gear ratio variable device 26.
[0079]
2-2. When the actual turning angle θw of the left and right front wheels has reached the target turning angle θwr (when θdd = 0)
In this case, the left and right front wheels are not steered, and only the steering wheel 14 is being rotated by the electric motor of the gear ratio variable device 26. It is not necessary to change the control of the gear ratio variable device 26 with respect to the amount of increase in the turning angle of the left and right front wheels due to the increase in the number of turns, and the increase correction amount corresponding to the amount of increase in the turning angle of the left and right front wheels is simply the target rotation of the steering wheel It only needs to be added to the angle θsr.
[0080]
(3) When the left and right front wheels are turned back before the steering wheel reaches the target rotational position
3-A. When the current steering position of the left and right front wheels is not between the current target steering position of the left and right front wheels and the new target steering position
Since the left and right front wheels are steered toward the current target steered position, even if the target steered position of the left and right front wheels is changed to the reverse direction, the roll of the vehicle body and the lateral acceleration of the vehicle are reversed. This is almost the same as when the target turning angle of the left and right front wheels is originally small.
[0081]
3-A-1. When the actual turning angle θw of the left and right front wheels has not reached the target turning angle θwr, and the rotation angle θs of the steering wheel 14 has not reached the target rotation angle θsr (when θdd ≠ 0)
In this case, since the size of the target turning angle of the left and right front wheels is reduced and the size of the target rotation angle θsr of the steering wheel 14 is correspondingly reduced, the steering of the left and right front wheels is equivalent. There is no need to change the control of the gear ratio variable device 26.
[0082]
3-A-2. When the actual turning angle θw of the left and right front wheels has reached the target turning angle θwr (when θdd = 0)
In this case, the left and right front wheels are not steered, and only the steering wheel 14 is being rotated by the electric motor of the gear ratio variable device 26. There is no need to change the control of the gear ratio variable device 26 for the amount of reduction in the turning angle of the left and right front wheels due to the switchback, and the magnitude of the target rotation angle θsr of the steering wheel 14 simply corresponds to the amount of reduction in the turning angle of the left and right front wheels. It is only necessary to reduce the amount to be used, and it is easier for the driver to understand the behavior of the vehicle.
[0083]
3-B. When the current steering position of the left and right front wheels is between the current target steering position of the left and right front wheels and the new target steering position
3-B-1. When the current rotational position of the steering wheel is not between the current target rotational position and the new target rotational position
3-B-1-1. When the actual turning angle θw of the left and right front wheels has not reached the target turning angle θwr, and the rotation angle θs of the steering wheel 14 has not reached the target rotation angle θsr (when θdd ≠ 0)
In this case, since the steering direction of the left and right front wheels is reversed, first, the upper steering shaft 22A is moved relative to the lower steering shaft 22B by the gear ratio variable device 26 until the steering position of the left and right front wheels reaches a new target steering position. By relatively rotating, the steering wheel 14 is kept stationary, and then the steering wheel 14 is rotated by the gear ratio variable device 26 to a new target rotation position at a predetermined rotational angular velocity.
[0084]
From the above equation 1, the following equation 13 is established, and therefore the following equation 14 is established. When the relative rotational angular velocity θvd, that is, the predetermined rotational angular velocity is set to (θdd−θsdr) according to the above equation 7, the rotational angular velocity θsd of the steering wheel 14 becomes the target rotational angular velocity θsdr as shown in the following equation 15.
[0085]

[0086]
In this case, since the new target rotation angle position of the steering wheel 14 is in the direction of increasing with respect to the current rotation angle position, the rotation direction of the steering wheel 14 is opposite to the turning direction of the left and right front wheels. However, the cycle of the control cycle is generally very small, and the amount of return at the time of lane keep control is generally small. This is because the rotation direction of the steering wheel 14 is opposite to the steering direction of the left and right front wheels. The driver does not feel uncomfortable.
[0087]
3-B-1-2. When the actual turning angle θw of the left and right front wheels has reached the target turning angle θwr (when θdd = 0)
In this case, first, the steering positions of the left and right front wheels are set to the new target steering so that the steering wheel 14 does not rotate in the additional direction after the steering wheel 14 rotates in the return direction. The steering wheel 14 is kept stationary by the gear ratio variable device 26 until the position is reached, and then the steering wheel 14 is rotated by the gear ratio variable device 26 to a new target rotational position at a predetermined rotational angular velocity.
[0088]
3-B-2. When the current rotational position of the left and right front wheels is between the current target rotational position and the new target rotational position
The control in this case may be the same as in the case of 3-B-1. However, in this case, since the new target rotational position of the steering wheel 14 is positioned in the return direction with respect to the current target rotational position, the rotational direction of the steering wheel 14 by the gear ratio variable device 26 is the steering direction of the left and right front wheels. In the same direction.
[0089]
As understood from the above consideration, the rotation angle θd of the lower steering shaft 22B is set to the target rotation angle θdr so that the turning angle θw of the left and right front wheels becomes the target turning angle θwr regardless of the change of the target turning angle of the left and right front wheels. The lower steering shaft 22B is rotationally driven by the electric power steering 16 at the rotational angular velocity θdd = B until the rotational angle θs reaches the target rotational angle θsr until the rotational angle θs of the steering wheel 14 reaches the target rotational angle θsr. In contrast, if the upper steering shaft 22A is rotated at the rotational angular velocity αrB, the rotational angular velocity of the steering wheel 14 can be controlled to the target rotational angular velocity θsdr, and the rotation of the steering wheel 14 with respect to the turning angle of the left and right front wheels It is understood that the angle shift, that is, the so-called midpoint shift can be prevented. .
[0090]
If the steering angle of the steering wheel 14 is not the target rotational angle θsr even when the steering of the left and right front wheels is completed and the rotational angle θd of the lower steering shaft 22B reaches the target rotational angle θdr, If the upper steering shaft 22A is rotated at the rotational angular velocity αrB relative to the lower steering shaft 22B by the gear ratio variable device 26 without rotating the lower steering shaft 22B, the rotational angular velocity of the steering wheel 14 is changed. It can be understood that the midpoint shift of the steering wheel 14 can be prevented.
[0091]
Next, the automatic steering control in the illustrated second embodiment will be described with reference to the flowchart shown in FIG. In FIG. 6, the same steps as those shown in FIG. 2 are assigned the same step numbers as those shown in FIG. Also, the control according to the flowchart shown in FIG. 6 is started by closing an ignition switch (not shown), and is repeatedly executed at predetermined time intervals.
[0092]
First, in step 10, a signal indicating the steering angle θs is read, and in step 60, it is determined whether or not the learning switch 56 is in an on state, and when a negative determination is made. The process proceeds to step 90 as it is, and when an affirmative determination is made, the process proceeds to step 70.
[0093]
In step 70, it is determined whether or not the calculation of the average value of the rotational angular speed of the steering wheel 14 is completed as the learned value of the steering speed by the driver for each vehicle speed section, and when an affirmative determination is made. The process proceeds to step 100, and if a negative determination is made, the process proceeds to step 80.
[0094]
In step 80, the vehicle speed section is determined based on the vehicle speed V, and the average value of the rotational angular speed of the steering wheel 14 is calculated as the learning value of the steering speed by the driver for the vehicle speed section in the manner described above. In step 90, the ratio target value αr is set to its default value αo (a positive constant greater than 0 and less than 1).
[0095]
In step 100, the rotational angular velocity B of the lower steering shaft 22B is calculated based on the vehicle speed V so that the absolute value of the rotational angular velocity B of the lower steering shaft 22B for automatic steering decreases as the vehicle speed V increases.
[0096]
In step 110, the vehicle speed section to which the vehicle speed V belongs is specified based on the vehicle speed V, and the above formula is calculated based on the target rotational angular speed θsdr and the rotational angular speed B of the lower steering shaft 22B stored for the specified vehicle speed section. The target value αr of the ratio is calculated according to 6.
[0097]
In step 120, it is determined whether or not the lane keep switch 54 is in the on state. If a negative determination is made, steps 210 to 240 are performed in the same manner as in the first embodiment. When a positive determination is made, the lane keep, that is, the target turning angle θwr of the left and right front wheels necessary for driving the vehicle along the travel path is calculated in step 130, and then the above-mentioned first Steps 140 to 200 are executed as in the case of the embodiment.
[0098]
Thus, according to the second embodiment, when the learning switch 56 is in the OFF state, the target value αr of the ratio is set to the default value αo in step 90, but when the learning switch 56 is in the ON state, steering is performed. Until the speed learning is completed, a representative rotational angular speed of the steering wheel during the steering operation by the driver is calculated as a learning value. In step 100, the optimum rotational angular velocity B of the lower steering shaft 22B at the time of automatic steering is calculated according to the vehicle speed V, and in step 110, the rotational angular velocity B and the steering wheel target stored as the learning value are calculated. A target value αr of the ratio is calculated based on the rotational angular velocity θsdr.
[0099]
Therefore, according to this second embodiment, the steering wheel 14 can be rotated at a rotational angular speed corresponding to the steering speed of the driver during the normal steering operation of the driver even during the automatic steering of the lane keep, As a result, it is possible to reliably prevent the steering wheel 14 from rotating at an unnatural rotational angular velocity during the automatic steering of the lane keep and the driver from feeling uncomfortable due to this.
[0100]
Also in this second embodiment, even if the steering angle θw of the left and right front wheels becomes substantially the target steering angle θwr and the steering of the left and right front wheels is completed, the rotation angle θs of the steering wheel 14 is When the target rotational angle θsr has not been reached, a negative determination is made in step 150, but an affirmative determination is made in step 190, and in step 200 the upper steering shaft 22A is lowered by the gear ratio variable device 26. The steering wheel 14 is rotationally driven at a rotational speed of αrB relative to the steering shaft 22B, whereby the steering wheel 14 is rotationally driven at the target rotational angle θsr.
[0101]
Therefore, it is possible to reliably prevent the rotation angle θs of the steering wheel 14 from not corresponding to the turning angle θw of the left and right front wheels and the subsequent adverse effect on the steering by the driver due to this. Immediately after the steering of the left and right front wheels is completed, it is possible to reliably prevent the rotation angle of the steering wheel 14 from changing suddenly and the driver from feeling uncomfortable due to this.
[0102]
Further, according to the second embodiment shown in the figure, in step 100, the optimum rotational angular velocity B of the lower steering shaft 22B during automatic steering is calculated according to the vehicle speed V, and based on the vehicle speed V in step 110. Since the target rotational angular velocity θsdr is determined and the target value αr of the ratio is calculated based on the target rotational angular velocity θsdr and the rotational angular velocity B of the lower steering shaft 22B, the steering speed of the left and right front wheels for lane keeping control is set to the vehicle speed. Accordingly, the lane keeping control can be performed optimally regardless of the vehicle speed as compared with the case where the rotational angular velocity B of the lower steering shaft 22B is constant during automatic steering. In addition, the rotational angular velocity of the steering wheel 14 can be ensured in the lane keeping control regardless of the fluctuation of the rotational angular velocity B. Thus, the target rotation angle θsr can be controlled.
[0103]
Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to the above-described embodiments, and various other embodiments are possible within the scope of the present invention. It will be apparent to those skilled in the art.
[0104]
For example, the rotational angular velocity B of the lower steering shaft 22B is constant in the above-described first embodiment, and is variably set according to the vehicle speed V in the above-described second embodiment. However, in the first embodiment, the rotational angular velocity B may be variably set according to the vehicle speed V, and the steering angle θw of the left and right front wheels is gradually decreased immediately before reaching the target steering angle θwr. May be.
[0105]
Further, in each of the above-described embodiments, the automatic steering is the parking assist control or the lane keeping control automatic steering, and the target turning angle of the left and right front wheels is the target turning for achieving the parking assist control or the lane keeping control. Although it is an angle, automatic steering is automatic steering for any purpose known in the art, such as automatic steering to avoid obstacles in front of the vehicle and automatic steering to stabilize the behavior of the vehicle. It may be.
[0106]
In the second embodiment described above, the learning of the steering speed at the time of the steering operation by the driver is calculated as an average value of n maximum steering speeds for each vehicle speed section. A reference value may be calculated so as to decrease as the vehicle speed V increases, and an average value may be calculated for the maximum value of the steering angular speed whose magnitude is greater than or equal to the reference value. A constant integer) of steering angular velocities, a steering speed corresponding to the maximum number of the normal distributions may be calculated as a learning value, and a value indicating the steering speed at the time of the driver's steering operation. As long as it is, it may be calculated in any manner.
[Brief description of the drawings]
FIG. 1 is a schematic configuration showing a first embodiment of an automatic steering device for a vehicle according to the present invention which is applied to a vehicle equipped with a gear ratio variable device and an electric power steering device and is configured to perform automatic parking assist steering. FIG.
FIG. 2 is a flowchart showing an automatic steering control routine in the first embodiment.
FIG. 3 is a graph showing a relationship between a steering torque T and a basic assist amount Tab.
FIG. 4 is a graph showing a relationship between a vehicle speed V and a vehicle speed coefficient Kv.
FIG. 5 shows a second embodiment of the vehicle automatic steering device according to the present invention applied to a vehicle which is applied to a vehicle equipped with a gear ratio variable device and an electric power steering device and is configured to perform automatic steering of a lane keep. It is a schematic block diagram which shows a form.
FIG. 6 is a flowchart showing an automatic steering control routine in the second embodiment.
[Explanation of symbols]
10FR ~ 10RL ... wheel
16 ... Electric power steering device
22 ... Steering shaft
22A ... Upper steering shaft
22B ... Lower steering shaft
26. Gear ratio variable device
30 ... Power unit
34, 38 ... Steering angle sensor
36 ... Torque sensor
40. Electronic control unit
42 ... Vehicle speed sensor
44 ... Parking assist switch
46 ... Setting dial
48 ... Video camera
54 ... Lane Keep Switch
56 ... Learning switch
58 ... Video camera

Claims (8)

An automatic steering means for steering the steering wheel without depending on a steering operation of the driver with respect to the steering wheel, and the steering with respect to the steering angle of the steering wheel provided in a steering system between the steering wheel and the steering wheel A ratio variable means for changing a ratio of the rotation angle of the wheel, a target ratio setting means for setting a target ratio of the rotation angle of the steering wheel with respect to the steering angle of the steering wheel, and a target turning angle of the steering wheel Control means for controlling the automatic steering means based on the target turning angle and for controlling the ratio variable means so that a ratio of a rotation angle of the steering wheel to a turning angle of the steering wheel becomes the target ratio. An automatic steering device for a vehicle characterized by comprising: The target ratio setting means sets a target rotation angular speed of the steering wheel, and sets the target ratio based on the target rotation angular speed and a turning speed of the steered wheels by the automatic steering means. The automatic steering device for a vehicle according to 1. The target ratio setting means includes a steering speed storage means for storing a steering speed when the driver rotates the steering wheel in correspondence with the vehicle speed, and based on the vehicle speed and the steering speed stored by the steering speed storage means. The vehicle automatic steering apparatus according to claim 2, wherein the target rotational angular velocity is set. 3. The vehicle automatic according to claim 2, wherein the target ratio setting means includes an operating means that is set and operated by a driver, and sets the target rotational angular velocity according to the setting of the operating means by the driver. Steering device. The ratio variable means is provided between the first steering shaft on the steering wheel side and the second steering shaft on the steering wheel side, and the second steering shaft is relative to the first steering shaft. 5. The vehicle automatic steering device according to claim 1, wherein a ratio of a rotation angle of the steering wheel to a steering angle of the steering wheel is changed by rotating the steering wheel. The target ratio setting means sets the target ratio by setting a target value of a ratio of a relative rotation angle of the first and second steering shafts to a rotation angle of the first steering shaft. The vehicle automatic steering apparatus according to claim 5. The control means calculates a target rotation angle of the first steering shaft for setting the steering angle of the steered wheel to the target steering angle, and the automatic control is performed based on the target rotation angle of the first steering shaft. 7. The vehicle automatic steering apparatus according to claim 6, wherein the steering means is controlled, and the ratio variable means is controlled based on the target value of the ratio. The control means calculates a target rotation angle of the second steering shaft based on the target rotation angle of the first steering shaft and a target value of the ratio, and the rotation angle of the first steering shaft is the target rotation. If the rotation angle of the second steering shaft is not the target rotation angle after the time when the angle is reached, the target of the ratio is maintained until the rotation angle of the second steering shaft reaches the target rotation angle. 8. The vehicle automatic steering apparatus according to claim 7, wherein the control of the ratio variable means based on the value is continued.

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