JP3902044B2 - Shift control device for automatic transmission - Google Patents

Description

【００４６】
油圧制御回路４０は、図１に示したように、変速制御装置５０からの制御指示信号により制御される３個のオン・オフソレノイドバルブ４１〜４３及び４個のリニアソレノイドバルブ４４〜４７を含んでいて、前記オン・オフソレノイドバルブ４１〜４３の作動の組み合わせに基づいて自動変速機３０の摩擦係合要素に対する油の給排を制御するとともに、前記リニアソレノイドバルブ４４〜４６を駆動して同給排される油の圧力（油圧）をライン圧以下の範囲内で調整し得るようになっている。
【００４７】
また、前記リニアソレノイドバルブ４７の駆動によりロックアップクラッチ機構２２に給排される油圧をライン圧以下の範囲内で調整し得るようになっている。このクラッチ機構２２の制御も変速制御装置５０によるものとされる。従って装置５０は、ロックアップクラッチ制御手段を構成している。
【００４８】
変速制御装置５０は、何れも図示を省略したＣＰＵ、メモリ〔ＲＯＭ、ＲＡＭ）、及びインタフェースなどから成るマイクロコンピュータであって、スロットル開度センサ６１、エンジン回転速度センサ６２、入力軸（タービン）回転速度センサ６３、及び出力軸回転速度センサ６４と接続されていて、これらのセンサ６１〜６４が発生する信号を入力するようになっている。
【００４９】
スロットル開度センサ６１は、エンジン１０の吸気通路に設けられ図示しないアクセルペダルの操作に応じて開閉されるスロットルバルブ１１の開度を検出し、同スロットル開度Ｔｈを表す信号を発生するようになっている。
エンジン回転速度センサ６２は、エンジン１０の回転速度を検出し、同エンジン回転速度Ｎｅを表す信号を発生するエンジン回転速度検出手段を構成している。
【００５０】
入力軸回転速度センサ６３は、自動変速機の入力軸３１の回転速度を検出し、同入力軸回転速度（タービン回転数）Ｎｔを表す信号を発生する入力軸回転速度検出手段を構成している。
【００５１】
出力軸回転速度センサ６４は、自動変速機の出力軸３２の出力軸回転速度Ｎｏ（アウトプット回転数）を検出し、同出力軸回転速度（即ち、車速に比例する値）Ｎｏを表す信号を発生する出力軸回転速度検出手段を構成している。
【００５２】
上記変速制御装置５０は、出力軸回転速度Ｎｏとスロットル開度Ｔｈとで構成される変速マップ及びロックアップクラッチ作動マップをメモリ内に記憶していて、検出された出力軸回転速度Ｎｏと検出されたスロットル開度Ｔｈにより定まる点が変速マップに示された変速線を横切るとき、油圧制御回路４０のオン・オフソレノイドバルブ４１〜４３及びリニアソレノイドバルブ４４〜４６を制御して、上記表１に示したように摩擦係合要素の係合・解放状態を変更するとともに、前記検出された出力軸回転速度Ｎｏと前記検出されたスロットル開度Ｔｈとにより定まる点が、図３（Ａ）及び図３（Ｂ）に示したロックアップクラッチ作動マップのロックアップ線を横切るとき、リニアソレノイドバルブ４７を制御して、ロックアップクラッチ２２ａの係合・解放状態を変更するようになっている。
【００５３】
具体的に述べると、図３は、ロックアップクラッチが解放状態にある場合、及びロックアップクラッチが係合状態にある場合のロックアップクラッチ作動線を変速段別にそれぞれ示している。
【００５４】
例えば、ロックアップクラッチが解放状態にあって変速段が２速であるときには、実際のスロットル開度Ｔｈと実際の出力軸回転速度Ｎｏとにより定まる点（運転状態点）が図３（Ａ）中の最も左のロックアップクラッチ作動線を左から右へ横切るとき、ロックアップクラッチが係合状態へと変更される。
【００５５】
また、運転状態点が図３（Ａ）のロックアップクラッチ作動線を左から右へと横切って斜線を付した領域に入った場合には、ロックアップクラッチが解放状態からスリップ状態へと変更される。
【００５６】
一方、一旦、ロックアップクラッチが係合状態に変更されると、図３（Ｂ）のロックアップクラッチ作動線が選択される。
例えば、変速段が２速であるときにロックアップクラッチが係合状態にあると、運転状態点が図３（Ｂ）の左端の破線で示したロックアップウラッチ作動線を右から左へと横切ったとき、ロックアップクラッチが係合状態から解放状態へと変更される。
【００５７】
次に、上記のように構成された自動変速機の変速制御装置が、２速から３速への変速時に行うクラッチツウクラッチ制御について説明する。
説明に関しては、クラッチツウクラッチ制御の概要から説明する。
【００５８】
（概要）
図４（Ａ）〜図４（Ｅ）を参照しながら、２速から３速への変速時における油圧制御の概要について説明する。
図４（Ａ）において実線及び破線は、解放側摩擦係合要素（ブレーキＢ１）に対する指示油圧（以下、「解放側指示圧」と云う。）、及び係合側摩擦係合要素（クラッチＣ３）に対する指示油圧（以下、「係合側指示圧」と云う。）を、それぞれ表している。
【００５９】
図４（Ｂ）において、実線及び破線は、解放側摩擦係合要素に対する実際の油圧（以下、「解放側油圧」と云う。）、及び係合側摩擦係合要素に対する実際の油圧（以下、「係合側油圧」と云う。）をそれぞれ表している。
【００６０】
時刻ｔ１において、出力軸回転速度Ｎｏとスロットル開度Ｔｈとで定まる点が２速から３速へのシフトアップ変速線を横切ると、変速制御装置５０は解放側油圧をライン圧ＰＬから急速に減少させ、さらに所定時間の経過後（係合側クラッチのプリチャージの終了後）、圧を所定割合で減少させる（開放初期ランプ制御）。これにより、図４（Ａ）（Ｅ）に示すように、時刻ｔ３にて解放側摩擦係合要素がスリップし始める。
【００６１】
次いで、変速制御装置５０は後述するスリップ量ＦＢ制御を行う。この結果、図４（Ｅ）に示したように、時刻ｔ３〜ｔ４においてスリップ量は滑らかに上昇する。
【００６２】
一方、変速制御装置５０は、係合側に関して、時刻ｔ１から所定時間だけ係合側油圧を急激に上昇させるプリチャージ制御を行い、同プリチャージ制御を時刻ｔ２で終了するとスリップが開始するまで係合側油圧を一定値に維持する係合待機圧制御を行う。
そして、前記した時刻ｔ３においてスリップが開始すると、係合側油圧を所定の棚圧に維持するランプ昇圧制御を開始する。これにより、係合側摩擦係合要素がトルクの伝達を開始し、スリップ量が減少し始める。
このとき、変速制御装置５０は上記スリップ量ＦＢ制御によりスリップ量を目標スリップ量に維持しようとするので、同スリップ量を増大させようとして解放側油圧を減少させる。
【００６３】
この状態が継続し時刻ｔ５においてスリップ量が消失すると、変速制御装置５０は解放側油圧を直ちに「０」まで減圧する（ランプ開放制御）とともに、係合側油圧を入力軸回転速度Ｎｔの変化率△Ｎｔが、所定の目標回転変化率△ＭＮｔとなるように制御するイナーシヤＦＢ制御を実行する。
【００６４】
時刻ｔ６にて入力軸回転速度Ｎｔが変速後（この場合は３速）のギヤ比Ｇ２と出力軸回転速度Ｎｏとの積に一致すると（即ち、図４（Ｃ）において、Ｎｔ＝Ｎｏ・Ｇ２となると）、係合側油圧をライン圧ＰＬまで増大させる。
以上により、クラッチツウクラッチ変速が終了する。
【００６５】
（スリップ量ＦＢ制御系の構成）
スリップ量ＦＢ制御に関して、１．制御開始判定、２．スリップ量ＦＢ制御、３．制御終了判定の順に説明する。
【００６６】
１．スリップ開始判定
図５は、スリップ量ＦＢ制御の開始判定を行う場合に使用するスリップ量演算のブロック図である。
同図に示すように、この判定にあたっては、入力軸回転速度Ｎｔ，出力軸回転速度Ｎｏ及び変速前ギヤ比Ｇ１に基づいて仮スリップ量Ｓｌｉｐ＝Ｎｔ−Ｎｏ・Ｇ１を求め、これを開始判定用ローパスフィルタＬＰＦ（１０ＨｚＬＰＦ）で処理する。
ここで、この開始判定用ＬＰＦとして１０Ｈｚのものを採用している。
【００６７】
この様にして得られた開始判定用ＬＰＦ処理後のスリップ量Ｓｌｉｐｆｌｔが所定のしきい値［ｎ₁ 回転］を越えた場合に、スリップが発生していると判定し、先に説明した時刻ｔ３が設定され、本願のスリップ量ＦＢ制御を開始する。
【００６８】
２．スリップ量ＦＢ制御
この制御は、上述した時刻ｔ３〜ｔ５間において実行される。
制御は、規範モデルＭ（ｓ）によって生成される実質的な目標スリップ量になるように制御を施すものであり、ＰＩフィードバック制御を施す構成とされ、誤差要素も加味される。さらに、入力軸回転速度Ｎｏ及び出力軸回転速度Ｎｔに基づいて、スリップ量Ｓｌｉｐの演算が実行され、ロックアップクラッチが係合以外の状態にある場合と、係合状態にある場合とを対象として、その両状態に対応した制御が可能な構造が採用されている。
【００６９】
制御ブロックを図６に示した。以下、各制御要素の順に説明する。
イ 規範モデルＭ（ｓ）
この規範モデルＭ（ｓ）は、図８に示すものとみなせ、図９に示したように、０から所定の値ｒｓにステップ状に変化する目標スリップ量ＲＳｌｉｐを入力として与えた場合、時間の経過に従って連続的に徐変するとともに値ｔｒで決まる時間を経て、前記所定の値ｒｓに到達する「変速ショックを生じさせない」理想のスリップ量ＭＤＬｏｕｔを出力するものであり、同規範モデルＭ（ｓ）の伝達関数は「二項モデル」を用いて決定される。
具体的には、規範モデルＭ（ｓ）は下記数１により表される。
なお、数１を含む以下の数式において、「ｓ」は微分演算子を表す。
【００７０】
【数１】
Ｍ（ｓ）＝１／（ｔｒ・ｓ＋１）²
【００７１】
ロ 制御対象Ｐ（ｓ）
制御対象Ｐ（ｓ）は、入力を解放側油圧（ブレーキＢ１の係合圧）とするとともに出力を実際のスリッブ量（実スリップ量Ｓｌｉｐ）として、システム同定の手法を用いて決定した自動変速機全体の伝達関数である。
【００７２】
本実施形態においては、図６の制御ブロック図に示したように、上記規範モデルＭ（ｓ）、フィードバックコントローラＣｐｉ（ｓ）、制御対象Ｐ（ｓ）、第一ローパスフィルタＬＰＦ１、ノッチフィルタＮＦ、Ｎｔオフセット決定部ＮＴＯＦＳ、切換え部ＳＷ、第二ローパスフイルタＬＰＦ２、ギヤ比乗算器ＡＭＰ、Ｎｏオフセット決定部ＮＯＯＦＳ及び誤差フィードバックコントローラＣｅｆにより閉ループ系が構築されている。
【００７３】
フィードバックコントローラＣｐｉ（ｓ）は、比例積分制御器（ＰＩコントローラ）であり、その目標入力値を上記規範モデルＭ（ｓ）の出力ＭＤＬｏｕｔとする。
フィ−ドバックコントローラＣｐｉ（ｓ）は、下記数２で表される。
【００７４】
【数２】
Ｃｐｉ（ｓ）＝Ｋｐ＋Ｋｉ／ｓ
【００７５】
数２における比例ゲイン（比例感度）Ｋｐと積分ゲイン（積分感度）Ｋｉは、次のようにして実験により求める。
即ち、上記制御対象Ｐ（ｓ）に対して図１０に示したフィードバック系を構成する。このフィードバック系は、図６に示した系から、規範モデルＭ（ｓ）、ノッチフィルタＮＦ、Ｎｔオフセット決定部ＮＴＯＦＳ、切換え部ＳＷ、及び誤差フィードバックコントロ−ラＣｅｆを除いた系である。
これにより、フィードバックコントローラＣｐｉ（ｓ）に入力されるフィードバック制御量Ｓｌｉｐｏｎは下記数３に示した量となる。
【００７６】
【数３】
Ｓｌｉｐ＝Ｓｌｉｐｏｎ＝Ｎｔｆ１ｔ−Ｎｏｆｌｔ・Ｇ１＋Ｎｏｓａ
【００７７】
ここで、
Ｎｔｆｌｔは、制御対象Ｐ（ｓ）の出力の一つである入力軸回転速度Ｎｔを第一周波数［例えば、２０Ｈｚ］以上の周波数成分を除去する第一ローパスフィルタ処理して得られるローパスフィルタ処理後入力軸回転速度である。この第一ローパスフィルタが本願にいう入力値処理手段を成し、Ｎｔｆｌｔがフィルタ処理後入力軸回転関連速度となる。
【００７８】
Ｎｏｆｌｔは、制御対象Ｐ（ｓ）の出力の一つである出力軸回転速度Ｎｏを第一周波数より小さい第二周波数［例えば、１Ｈｚ］以上の周波数成分を除去する第二ローパスフィルタ処理して得られるフィルタ処理後出力軸回転速度である。
【００７９】
Ｎｏｓａは、解放側摩擦係合要素を徐々に低下させることにより、スリップ量ＦＢ制御開始時に下記の式に基づいてＮｏオフセット決定部ＮＯＯＦＳにより求められる。この部位が、本願のオフセット決定手段を構成する。
【００８０】
【数４】
Ｎｏｓａ＝Ｎｔｆｌｔ−Ｎｏｆｌｔ・Ｇ１−ｎ₁
ここで、ｎ₁ はスリップ開始判定しきい値である。
【００８１】
Ｇ１は、クラッチツウクラッチ変速前における変速段の変速前のギヤ比であり、乗算器ＡＭＰにより乗じられる。
ここで、第二ローパスフィルタＬＰＦ２と乗算器ＡＭＰとで、本願にいう出力値処理手段が構成されている。Ｎｏｆｌｔ・Ｇ１がフィルタ処理後出力軸回転関連速度となる。
【００８２】
従って、上記のフィードバックコントローラＣｐｉ（ｓ）に関する制御ゲイン（比例ゲインＫｐと積分ゲインＫｉ）は、ロックアップクラッチが係合状態にある場合において、目標スリップ量が所定値を超えたとき、目標スリップ量をフィードバックコントローラＣｐｉ（ｓ）に与え、スリップ量が振動して発散することなくフィードバック制御（サーボ）可能となる比例ゲインＫｐと積分ゲインＫｉとして求まる。このようにして、フィードバックコントローラＣｐｉ（ｓ）が決定される。
【００８３】
ハ ノッチフィルタＮＦ
再び、図６を参照すると、ノッチフィルタＮＦは、そのボード線図である図１１に示したように、特定の周波数（本明細書では、「ノッチ周波数」と云う。）近傍の周波数帯域におけるゲインが極めて小さく、入力信号に含まれる同ノッチ周波数近傍の周波数成分を除去するフィルタである。
このノッチ周波数は．ロックアップクラッチが係合状態以外の状態（例えば、解放状態、及びスリップ状態、即ち、完全係合状態以外の状態）にあるときに、上記のようにして決定されたフィードバックコントローラＣｐｉ（ｓ）を用いるとともに、フイードバック量としてのスリップ量を上記スリップ量Ｓｌｉｐｏｎとしてクラッチツウクラッチ変速を行つた場合に、入力軸回転速度Ｎｔに発生する振動の中心周波数近傍の周波数である。
【００８４】
前記ノッチフィルタには第一ローパスフィルタＬＰＦ１処理後の出力が入力され、入力軸回転速度Ｎｔに含まれる同第一周波数以上の周波数成分が除去されたＮｔｆｌｔに対して、ノッチフィルタ処理を施し、ノッチフィルタ処理後入力軸回転速度ＮｔＮｏｔｃｈが出力される。
【００８５】
ニ Ｎｔオフセット決定部
Ｎｔオフセット決定部ＮＴＯＦＳは、ノッチフィルタＮＦにより生じるノッチフィルタ処理後入力軸回転速度ＮｔＮｏｔｃｈの入力軸回転速度Ｎｔｆｌｔに対する遅れ分を補償するためのオフセットＮｔｓａを決定するためのものである。このオフセットＮｔｓａは，数５に示す下記式で求める。
【００８６】
【数５】
Ｎｔｓａ＝Ｎｔｆｌｔ−ＮｔＮｏｔｃｈ
【００８７】
ホ 切換え部ＳＷ
切換え部ＳＷは、ロックアップクラッチが係合状態（完全係合状態）にある場合には、制御に用いるスリップ量（制御用スリップ量）を求めるための入力軸回転速度に対応する値としてローパスフィルタ処理後入力軸回転速度Ｎｔｆｌｔを選択する。この結果、制御用スリップ量は、上記数３により示したスリップ量Ｓｌｉｐｏｎとなる。
【００８８】
また、切換え部ＳＷは、ロックアップクラッチが係合状態以外の状態にある場合、制御用スリップ量を求めるための入力軸回転速度に対応する値としてノッチフィルタ処理後入力軸回転速度ＮｔＮｏｔｃｈにＮｔオフセットＮｔｓａを加えた値を選択する。この結果、スリップ量Ｓｌｉｐは、下記数６により示されるスリップ量Ｓｌｉｐｏｆｆとなる。
【００８９】
【数６】
Ｓｌｉｐ＝Ｓｌｉｐｏｆｆ
＝ＮｔＮｏｔｃｈ＋Ｎｔｓａ−Ｎｏｆ１ｔ・Ｇ１＋Ｎｏｓａ
【００９０】
ヘ 誤差フィードバックコントローラＣｅｆ
誤差フィードバックコントローラＣｅｆは、上記スリップ量を前記規範モデルＭ（ｓ）の出力ＭＤＬｏｕｔから減じることにより求められる誤差ｅｒｒ＝ＭＤＬｏｕｔ−Ｓｌｉｐを入力し、同誤差ｅｒｒをゲインＴＴ倍して出力ＥＦＢｏｕｔとしてする。コントローラＣｅｆの出力は、前記フィードバックコントローラＣｐｉ（ｓ）の入力に重畳させる。
【００９１】
なお、コントローラＣｅｆ（図６の例では、ゲインＴＴ）は、図６に示した系に基づいて実際に自動変速機のスリップ量を制御し、その際に制御用スリップ量が発散しないように定めておく。
以上の構成により、スリップ量Ｓｌｉｐがロックアップクラッチの係合状態に応じて異なるように求められ、同スリップ量が規範モデルの出力ＭＤＬｏｕｔに一致するように、解放側摩擦係合要素の伝達トルク（解放側指示圧）が制御されてスリップ量のフィードバック制御がなされる。
【００９２】
３ スリップ終了判定
スリップ終了判定を実行するスリップ量演算ブロックを、図７に示した。
このブロックは、図１０に示す系に対して、フィードバックコントローラＣｐｉ（ｓ）及びフィードバック経路を外したものとされており、以下の数７で示すスリップ量を、スリップ量ＦＢ制御の終了判定に使用するものである。
【００９３】
【数７】
Ｓｌｉｐ＝Ｎｔｆｌｔ−Ｎｏｆｌｔ・Ｇ１＋Ｎｏｓａ
【００９４】
この様にして得られた終了判定用スリップ量が所定のしきい値［例えば０回転］を越えた場合（マイナス側へ移行）に、イナーシャ相への移行が判断され、先に説明した時刻ｔ５が設定され、スリップ量ＦＢ制御を終了する。
この場合も、判定に使用するスリップ量は、フィルタ処理を経たものとなっている。
【００９５】
上記の構成において、図６に示すコントローラは、ＲＳｌｉｐ、Ｎｔ、Ｎｏを入力とし、Ｐ（ｓ）に対するコントローラ出力を得る３入力１出力系と見なすことができる。
そして、公知の手法により、コントローラのゲイン・位相特性を制御が最適化するように、ロックアップクラッチの係合状態及び係合状態以外の状態に対して求めることができる。結果、これらの両状態に対して、好適なクラッチツウクラッチ制御を実現することができる。
【００９６】
図１２に本願の制御構造を採用して、スリップ量ＦＢ制御を施した場合のＦＢ制御開始及び終了時点を示した。スリップの実状にあう開始・終了判定を行えた。
【００９７】
（具体的作動）
次に、上記自動変速機の変速制御装置のクラッチツウクラッチ変速における具体的作動を、２速から３速への変速を例にとって説明する。
図１３は制御において必要となる本処理を示すものであり、図１４は開放側油圧制御を、図１５、１６はスリップ量ＦＢ制御を、さらに図１７は係合側油圧制御におけるフローを示すものである。
【００９８】
１ 本処理
変速制御装置５０のＣＰＵは、ステップ１３００で初期化を実行し、ステップス１３０５に示すように所定のサンプリング時間（図示する例にあっては５ｍｓｅｃ毎）での処理を繰り返す処理である。即ち、ステップ１３３５に示すように、電源が切断されない限りにおいて、この処理が繰り返される。
【００９９】
ステップ１３１０において制御に必要となる入力軸回転速度（タービン回転数）Ｎｔ及び出力軸回転速度（アウトプット回転数）Ｎｏが取り込まれる。
ステップ１３１５にあっては、上記した実スリップ量が、Ｓｌｉｐ＝Ｎｔ−Ｎｏ・Ｇ１として算出される。
【０１００】
ステップ１３２０において、ステップ１３１５で得られた実スリップＳｌｉｐに対する、ＦＢ制開始判定用のローパスフィルタ処理を施す。処理は図示の式に従ったものとされる。ここで、添字ｎ等は、ｎ回目等のサンプリングの値であることを示す（以下同じ）。同式に示す、ａ１，ｂ１，ｂ２はカットオフ周波数の決定用の数値である。この処理により得られる１０ＨｚＬＰＦ処理後スリップ量を、スリップ量ＦＢ制御の開始判断に使用することができる。
【０１０１】
ステップ１３２２で、入力軸回転速度Ｎｔに対するローパスフィルタ処理を施す。この処理においてカットオフ周波数は２０Ｈｚに選択される。ｇ１，ｈ１，ｈ２はカットオフ周波数の決定用の数値である。この処理により所定の高周波成分が除去されたフィルタ処理後の入力軸回転速度Ｎｔｆｌｔが得られる。
【０１０２】
ステップ１３２５において、図示する式に従って、入力軸回転速度（タービン回転数）Ｎｔのノッチ処理が施される。
同式において、ｃ１，ｃ２、ｄ１，ｄ２、ｄ３はノッチカットオフ周波数の決定用の数値である。具体的には、このカットオフ周波数は７Ｈｚである。
この式において、ノッチ処理の対象となる入力軸回転速度Ｎｔｆｌｔは、先に説明した第一ローパスフィルタＬＰＦ１により処理済みの物理量である。また、この処理にあっては、前回（ｎ−１），前々回（ｎー２）のＮｔｆｌｔも加味される。
【０１０３】
ステップ１３３０で、出力軸回転速度（アウトプット回転数）Ｎｏに対するローパスフィルタ処理を施す。この処理においてカットオフ周波数は１Ｈｚに選択される。ｅ１，ｆ１，ｆ２はカットオフ周波数の決定用の数値である。この処理により所定の高周波成分が除去されたフィルタ処理後の出力軸回転速度Ｎｏｆｌｔが得られる。
【０１０４】
これらの前処理を経た後、図１５、１６に示すスリップ量ＦＢ制御に入り、これを終了した後、ステップ１３３５における判断をし、適宜終了する。
【０１０５】
２ スリップ量ＦＢ制御
イ ＦＢ制御開始処理
上記した図１３に記載のフローのステップ１３２０により得られるスリップ量Ｓｌｉｐｆｌｔの値が所定のしきい値ｎ１ を越えた時点で、スリップし始めたと判定し、スリップ量ＦＢ制御に入る。
このスリップ量ＦＢ制御のフローを図１５、１６に示した。
【０１０６】
ロ スリップ量ＦＢ制御
ステップ１５０５、１５１０において、フィードバック初期値Ｐの保存が行われ、比例ゲインＫｐ、積分ゲインＫｉ、誤差フィードバックゲインＴＴの読み込みが実行される。
【０１０７】
ステップ１５１５において、上記したオフセットＮｔｓａ及びＮｏｓａの算出が実行される。
即ちスリップ開始判定をした時点で、１ＨｚＬＰＦ処理後の出力軸回転速度ＮｏｆｌｔのオフセットＮｏｓａを、先に示した数４と同様な以下に示す式より求める。
【０１０８】
【数８】
Ｎｏｓａ＝Ｎｔｆｌｔ−Ｎｏｆｌｔ・Ｇ１−ｎ₁
ここで、ｎ₁ はスリップ開始判定しきい値である。
【０１０９】
これにより、スリップ判定した時点のＮｏ・Ｇ１は入力軸回転回転速度Ｎｔからしきい値分低い値であることから、入力軸回転速度Ｎｔｆｌｔをベースにして出力軸回転速度のオフセットＮｏｓａを取得することとなる。
【０１１０】
同時に、入力軸回転速度Ｎｔｆｌｔとノッチフィルタ処理後の入力軸回転速度ＮｔＮｏｔｃｈとのオフセットＮｔｓａも取得する。
この場合も、入力軸回転速度Ｎｔは、上記したようにＬＰＦ１でローパスフィルタ処理した後の入力回転速度とする。
【０１１１】
【数９】
Ｎｔｓａ＝Ｎｔｆｌｔ−ＮｔＮｏｔｃｈ
【０１１２】
以降、ステップ１５２０から１５７０に亘ってスリップ量ＦＢ制御を実行する。
ステップ１５２０で目標スリップ量ＲＳｌｉｐを読み込む。
【０１１３】
次にステップ１５２５、１５３０、１５３５での処理に移るが、先にも示したように、本願にあってはロックアップクラッチの係合状態に従って、そのフィードバックに使用される実スリップ量Ｓｌｉｐが異なる。
従って、ステップ１５２５において、ロックアップクラッチの係合状態を判定し、ロックアップクラッチが係合状態にある場合はステップ１５３０に進み、それ以外の場合は、ステップ１５３５に進む。
【０１１４】
ステップ１５３０及び１５３５にあっては、それぞれの状況に従って、制御に使用する実スリップ量Ｓｌｉｐを下記の式に従って求める。
【０１１５】
ステップ１５３０では、実スリップ量Ｓｌｉｐは、２０ＨｚＬＰＦ処理した入力軸回転速度Ｎｔｆｌｔおよび上で求めた出力軸回転速度ＮｏのオフセットＮｏｓａ、１ＨｚＬＰＦ処理した出力軸回転速度Ｎｏｆｌｔからスリップ量を算出しＦＢ制御を実行する。
【０１１６】
【数１０】
Ｓｌｉｐ＝Ｎｔｆｌｔ−Ｎｏｆｌｔ・Ｇ１＋Ｎｏｓａ
【０１１７】
ステップ１５３５では、実スリップ量Ｓｌｉｐを、ノッチフィルタ処理した入力軸回転速度ＮｔＮｏｔｃｈおよび上で求めた入力軸回転数ＮｔのオフセットＮｔｓａから実スリップ量Ｓｌｉｐを算出しＦＢ制御を実施する。
【０１１８】
【数１１】
Ｓｌｉｐ＝ＮｔＮｏｔｃｈ＋Ｎｔｓａ−Ｎｏ・Ｇ１＋Ｎｏｓａ
【０１１９】
ステップ１５４０における処理は、規範モデル演算処理であり、図示する数式に従った処理となる。
同式において、ＭＤＬｏｕｔ（ｎ）は規範モデル出力値を、添字ｎ、ｎ−１，ｎ−２等は、各段階のサンプリングのものであることを示しており、ａ１，ａ２，ｂ１，ｂ２，ｂ３はモデルに従って設定されている値である。
【０１２０】
ステップ１５４５にあっては、誤差フィードバックの演算を行う。
同演算においてＥＦＢｏｕｔは誤差フィードバック出力を、ＭＤＬｏｕｔは上記規範モデル演算で求められた出力を、ＴＴは先に説明した誤差に使用する比例ゲインである。
【０１２１】
ステップ１５５０にあっては、ＰＩ制御の入力値ＰＩｉｎの演算を行う。
ＰＩｉｎは、ＭＤＬｏｕｔとＥＦＢｏｕｔとの合算値と、実スリップ量Ｓｌｉｐとの差として求められる。
【０１２２】
図１６に示すように、ステップ１５５５にあっては、図示する式に従って、ＰＩ制御出力ＰＩｏｕｔの演算を行う。この演算にあっても、ｎ等はｎ回目等のサンプリングの値を意味し、ＳＭＰＬＴは、サンプリング時間である。
【０１２３】
ステップ１５６０にあっては、圧力の上下限チェックを実行する。
【０１２４】
ステップ１５６５にあっては、実ステップ量Ｓｌｉｐの演算を実行する。
ここで、この実スリップ量は図７に示す処理で得られるスリップ量になっている。具体的には、Ｓｌｉｐ＝Ｎｔｆｌｔ−Ｎｏｆｌｔ・Ｇ１＋Ｎｏｓａとされる。
【０１２５】
ハ スリップ量ＦＢ制御終了
スリップの終了判定は、上記ステップ１５６５で得られるスリップ量を使用して、ステップ１５７０に示すように、ロックアップクラッチの係合、非係合に係わらず、フィルタ処理による判定遅れによる解放側の引きずりを防止するため、ローパスフィルタを経たＮｔ，Ｎｏ回転速度を用いたスリップ量を用いてスリップ量を演算し、同スリップ量が所定のしきい値を下回った時点でＦＢ制御を終了する。
これにより、出力軸回転速度にノイズが重畳した場合においてもノイズの影響を受けることなくスリップの開始判定・スリップＦＢ制御を行うことが可能となる
【０１２６】
３ イナーシャ相への移行
以降、ステップ１５８０に示すように、ランプ開放フラグをたて、次のフェーズ（イナーシャ相）へ移行する。
【０１２７】
４ 開放側油圧制御及び係合側油圧制御
これらの油圧制御は、その所定ステップに本願が対象とするスリップ量ＦＢ制御を含むものであり、図４に示される所定順の制御を実行するものである。
図１４に示す開放側油圧制御に関して説明すると、所定の開始条件に従って、ステップ１４１０に示す開放初期ランプ制御（図４のｔ１〜ｔ３）を実行し、ステップ１４２０においてスリップの開始の有無を判定し、スリップが開始されていればステップ１４５０において本願によるスリップ量ＦＢ制御を実行し、スリップが開始されていない場合は、ステップ１４４０において、圧低下等を実行する強制スリップ開始制御を実行し、ステップ１４４５でスリップの開始を判定して、ステップ１４５０のスリップ量ＦＢ制御を実行するものである。
そして、スリップ量ＦＢ制御を完了した時点で、ステップ１４６０に移りランプ開放制御を実行し、一連の変速動作を完了し、次の変速待ちの状態とされる。
【０１２８】
一方、図１７に示す、係合側の油圧制御に関しては、ステップ１６１０で係合側の準備処理を行い、ステップ１６２０でプリチャージ制御を、ステップ１６３０で係合待機圧で、スリップの発生を待つ係合待機制御を実行する。
ステップ１６４０においてランプ昇圧制御を伴いながら、ステップ１６５０で、先のスリップ量ＦＢ制御の完了時点に対応するイナーシャ相開始判断を実行し、イナーシャ相が確立された段階で、ステップ１６６０におけるイナーシャ相ＦＢ制御に移行する。
【０１２９】
さらにこの制御状態で、ステップ１６７０に示す変速ギヤ比判定（図４に示すＮｔ＝Ｎｏ・Ｇ２の判定？）を繰り返し、この条件が満足された状態で、変速終了処理となる。
【０１３０】
［別実施の形態］
上記の実施の形態にあっては、ローパスフィルタ処理を実行するに、１０Ｈｚ以上の周波数成分を除去することとしたが、下限周波数は、その目的により、７〜１３Ｈｚの周波数範囲内で選択することが、自動変速機の変速制御装置に対して好ましい。
【図面の簡単な説明】
【図１】本発明による自動変速機の変速制御装置を車両に搭載した場合の概略構成図
【図２】図１に示した自動変速機のスケルトン図
【図３】（Ａ）は加速時におけるロックアップクラッチ作動マップ、
（Ｂ）は減速時におけるロックアップクラッチ作動マップを示した図
【図４】（Ａ）は変速時における解放側指示圧と係合側指示圧の制御指令値、
（Ｂ）は同変速時における実際の解放側油圧と係合側油圧、
（Ｃ）は同変速時におけるエンジン回転数、及び入力軸回転数、
（Ｄ）は同変速時におけるアウトプットトルク、
（Ｅ）は同変速時における実スリップ量を示すタイムチャート
【図５】スリップ量ＦＢ制御開始判定に使用するスリップ量演算ブロック図
【図６】スリップ量ＦＢ制御の制御ブロック図
【図７】スリップ量ＦＢ制御終了判定に使用するスリップ量演算ブロック図
【図８】規範モデルのブロック線図
【図９】図８に示した規範モデルに入力される目標スリップ量と、この入力に対する同規範モデルの出力を示したタイムチャート
【図１０】図６に示したフィードバックコントローラを決定するために用いるフィードバアック系を示すブロック線図
【図１１】ノッチフィルタのボード線図
【図１２】本願のスリップ量ＦＢ制御の開始・終了判定を行った場合の動作状況を示す図
【図１３】図１に示した変速制御装置のＣＰＵが実行する本処理のフローチャート
【図１４】図１に示した変速制御装置のＣＰＵが実行するプログラム（解放側油圧制御ルーチン）のフローチャート
【図１５】図１に示した変速制御装置のＣＰＵが実行するプログラム（スリップ量ＦＢ制御ルーチン）のフローチャート
【図１６】図１に示した変速制御装置のＣＰＵが実行するプログラム（スリップ量ＦＢ制御ルーチン）のフローチャート
【図１７】図１に示した変速制御装置のＣＰＵが実行するプログラム（係合側油圧制御ルーチン）のフローチャート
【図１８】従来の問題を含んだスリップ量ＦＢ制御の状況を示す図
【図１９】１／８なまし処理を行った場合の説明図
【図２０】オフセットの取り込み状況と、その問題点を示す図
【符号の説明】
１０…エンジン、
１２…トルクコンバータ入力軸、
２０…ロックアップクラッチ付流体式トルクコンバータ、
２１…流体式動力伝達機構、
２２…ロックアップクラッチ、
３０…自動変速機、
３１…入力軸、
３２…出力軸、
４０…油圧制御回路、
４１〜４３…オン・オフソレノイドバルプ、
４４〜４７…リニアソレノイドバルブ、
５０…制御装置、
６３…入力軸回転速度センサ、
６４…出力軸回転速度センサ、
Ｍ（ｓ）…規範モデル、
Ｐ（ｓ）…制御対象、
Ｃｐｉ（ｓ）…ＰＩコントローラ、
ＮＦ…ノッチフィルタ、
ＬＰＦ１…第一ローパスフイルタ、
ＬＰＦ２…第二ローパスフィルタ。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shift control apparatus for an automatic transmission for a vehicle that controls a plurality of friction engagement elements to automatically switch a shift stage, and more particularly, to output torque of an automatic transmission during clutch-to-clutch shift control. The present invention relates to a shift control device that can reduce fluctuations and achieve a good filling shift.
More specifically, when shifting from one shift stage to another shift stage of an automatic transmission that achieves a predetermined shift stage by maintaining each of the plurality of friction engagement elements in an engaged state or a released state, the same is applied. The transmission torque by the disengagement friction engagement element that is in the engaged state before the shift and released after the shift is reduced to generate slip, and in the released state before the shift and in the engaged state after the shift. The present invention relates to a shift control device for an automatic transmission provided with clutch-to-clutch control means for increasing the transmission torque by the engagement side frictional engagement element and performing the same shift.
[0002]
[Prior art]
In shifting the automatic transmission, it is necessary to reduce the transmission torque of the disengagement side frictional engagement element as the transmission torque of the engagement side frictional engagement element increases.
The one-way clutch is a mechanism that is employed to reduce the transmission torque of the disengagement side frictional engagement element.
[0003]
On the other hand, in recent years, a one-way clutch has been abolished, and “Clutch to Clutch” shift control has been adopted in which the function of the one-way clutch is achieved by hydraulic control to a friction engagement element.
[0004]
In such clutch-to-clutch shift control, if the hydraulic control is not properly performed, the output torque of the automatic transmission changes suddenly and the shift feeling is deteriorated.
For example, if the decrease in the transmission torque of the disengagement side frictional engagement element is delayed with respect to the increase in the transmission torque of the engagement side frictional engagement element, a so-called interlock state occurs and the output torque decreases rapidly. On the other hand, if the transmission torque of the disengagement side frictional engagement element decreases too quickly with respect to the increase of the transmission torque of the engagement side frictional engagement element, the input shaft rotational speed (turbine rotational speed) increases (that is, the input shaft rotational speed). As a result, the output torque decreases rapidly.
[0005]
In order to cope with this, so-called slip amount feedback (FB) control is performed in which the transmission torque of the disengagement side frictional engagement element is decreased to generate a slip, and in this state, the increase of the transmission torque of the engagement side frictional engagement element is waited. (JP-A-10-153257) has been studied.
[0006]
In this slip amount FB control, it is possible to use a controller (feedback controller) that performs proportional / integral control or the like that controls the transmission torque of the disengagement side frictional engagement element so that the slip amount matches the target slip amount. This is advantageous in suppressing fluctuations in the output torque of the automatic transmission due to vibration.
[0007]
When performing FB control, the raw slip amount Slip has been used for the start determination and the end determination. The slip amount Slip is obtained as Slip = Nt−No · G1, where Nt is the turbine rotational speed that is the input shaft rotational speed, No is the output rotational speed that is the output shaft rotational speed, and G1 is the gear ratio before the shift. .
[0008]
[Problems to be solved by the invention]
However, it has been found that there are the following problems when this slip amount is used. As an example, the case of an on-up shift shift will be described.
[0009]
1. Shift status
First, a normal shift state will be described with reference to FIG.
When a gear change command is issued, the hydraulic pressure of the release side clutch is once reduced by a predetermined value, then after a lapse of a predetermined time, the pressure is gradually reduced as necessary (open initial ramp control) to generate a slip. .
[0010]
The determination of the occurrence of the slip is based on the slip amount. When this value exceeds a predetermined threshold value, it is determined that the slip has occurred, and thereafter, the slip amount FB control described above is performed ( FIG. 4B).
[0011]
On the other hand, the engagement side hydraulic pressure is kept in the standby state by performing precharge / engagement standby pressure control until the release side slip is started, and is engaged when the slip starts, that is, when the torque phase is started. The pressure is increased to the shelf pressure (ramp pressure increase control) (FIG. 4A).
[0012]
As a result, transfer of torque from the disengagement side clutch to the engagement side clutch is started, and when the engagement side has sufficient torque, the slip disappears and shifts to the inertia phase (FIG. 4A).
As described above, when it is determined that the transition to the inertia phase has occurred, the release side clutch releases the hydraulic pressure (ramp release control) at that time, and the engagement side clutch has a predetermined inertia FB. Transition to control.
[0013]
2. Problem of slip amount FB control
When performing slip amount FB control, when high-frequency noise or the like is superimposed on the output rotational speed No, which is the output shaft rotational speed used at the time of slip amount FB start determination, the gear ratio (G1) before shifting is multiplied. Noise is superimposed.
[0014]
When the amplitude of the slip amount Slip thus obtained exceeds the slip amount FB control start determination threshold value, the threshold value is exceeded even when no slip actually occurs. The amount FB control is started.
[0015]
However, in this case, since the threshold value is exceeded due to noise, if the slip disappears in the next sampling, the process proceeds to the next phase (inertia FB control). In this case, the release-side clutch is fully released and the joint-side clutch shifts to inertia FB control, and the release-side clutch is fully released even though the joint-side clutch does not reach a sufficient pressure. E / G blowing occurs and the feeling deteriorates.
[0016]
This situation will be described with reference to FIG. In the figure, the solid line indicates the raw slip amount Slip, and the alternate long and short dash line [n₁Rotation] indicates the threshold value used for the conventional slip start determination, and the broken line [0 rotation] along the horizontal axis indicates the threshold value for determining the end of the conventional slip amount FB control.
When the threshold value indicated by the one-dot chain line and the broken line indicates the start / end of FD control based on the slip, the FD control is started at the timing indicated by the left broken line along the vertical axis, and immediately after that, due to noise. An erroneous end determination is made.
[0017]
In order to prevent this slip detection misjudgment, the threshold of slip detection is raised (FIG. 18 shows a two-dot chain line [n₂Rotation]) is also possible, but slipping detection is delayed (indicated by the broken line on the right side along the vertical axis), resulting in increased torque loss and worsening of the feeling. Is not the best way to stay.
[0018]
As a measure for preventing the above-described erroneous determination, it is conceivable to perform a smoothing process to remove the vibration of the output shaft rotational speed No. In this case, the calculated slip amount Slip is larger than the actual slip ( Therefore, the slip determination threshold value must be increased, resulting in a delay in the start of slip amount FB control and a worse feeling. This situation is shown in FIG. As shown in the figure, the results of the annealing process (specifically, 1/8 annealing process) are indicated by a one-dot chain line. It can be seen that raising the threshold is necessary.
[0019]
3 The problem of offset
Although related to the start / end determination of the slip amount FB control described above, it has been found that the slip amount used for this control has the following problems in relation to the offset processing at the time of control. This problem will be described with reference to FIGS.
[0020]
In the slip amount FB control, since the drive system vibration is superimposed on the output shaft rotational speed No, low-pass filter processing [specifically, 1 Hz LPF processing] is performed in order to remove this influence. The offset due to the LPF processing was acquired as the difference between the output shaft rotational speed No and the value after the 1 Hz LPF processing. However, since the output shaft rotational speed No itself vibrates as described above, the obtained offset Nosa is also obtained. It will vary.
[0021]
FIG. 20A is an explanatory diagram of this problem, and the offset that is earned with respect to the actual output shaft rotational speed No indicated by the solid line is the first offset and the second offset at the timing of the offset capture. As shown, it shows a big difference.
[0022]
As a result, when the offset obtained in this way is used for slip amount FB control, the slip amount drifts, so that the entity cannot be represented and the slip amount FB control cannot be executed correctly. This situation is shown in FIG. It can be seen that the slip amount determined corresponding to different offsets greatly depends on the offset.
Also in this case, the slip amount cannot be said to well represent the state of the system, and good slip amount FB control cannot be realized.
[0023]
An object of the present invention is to provide a shift control device that can appropriately set the start timing of the slip amount FB control and can maintain a good shift feeling in the clutch-to-clutch shift control of an automatic transmission.
[0024]
[Means for Solving the Problems]
  The features of the invention are as described in claim 1,
  The clutch-to-clutch control meansBut,
  Input shaft rotational speed acquisition means for acquiring an input value according to the input shaft rotational speed of the automatic transmission; and Output shaft rotational speed acquisition means for acquiring an output value according to the output shaft rotational speed of the automatic transmission. Prepared,
  A feedback controller for controlling a transmission torque by the disengagement side frictional engagement element so that a control slip amount obtained based on the input value and the output value is equal to a predetermined target slip amount;
  Control start judgment by the feedback controllerDefinite, Obtained from the input value and the output value, and a predetermined valueFor the first bandBased on the amount of slip that has been filteredWith
  Input value processing means for applying a filtering process to a predetermined second band set separately from the first band to give the input shaft rotation-related speed after the filter process to the input value;
The output value is subjected to a low-pass filter process for a predetermined third band set lower than the second band, and a post-filtering output shaft rotation-related speed obtained by multiplying the post-processing value by a gear ratio before shifting. Output value processing means for providing,
Based on the slip amount determined based on the post-filter processing input shaft rotation-related speed and the post-filter processing output shaft rotation-related speed, the end determination of the slip amount feedback control is executed.There is.
[0025]
  Although the role of the feedback controller is as described above, in this application, the start determination of the slip amount FB control is performed.DefiniteThe givenFor the first bandThis is performed based on the slip amount subjected to the filter processing.
  Further, the end determination of the slip amount FB control is performed based on the slip amount obtained based on the input shaft rotation-related speed after the filter process and the output shaft rotation-related speed after the filter process.
  As such a filter process, it is typically easy to execute a low-pass filter process that removes a high-frequency component, which is a noise component, but when a specific frequency component or band is a problem, such a process is performed. Appropriate filtering is performed for each purpose.
[0026]
In this case, the filter processing target is a signal corresponding to the slip amount.
In this way, the influence of noise components or the influence of a specific frequency band such as torsional vibration of the drive system can be excluded, the slip condition can be determined, and the start of the slip amount FB control can be made appropriate. The above problems can be solved.
[0027]
  In this structure, as defined in claim 2, the predeterminedFor the first bandThe filter process is preferably a low-pass filter process.
[0028]
In this structure, by adopting a low-pass filter, it is possible to appropriately execute start / end of the slip amount FB control without being affected by removing a high-frequency component that is a problem for a qualified representative of the slip amount. .
[0029]
  Now, claims3The invention according to the present invention intends to solve the problems related to the offset processing.
[0030]
  That is, as described in claim 3,
in frontInput shaft rotation-related speed after filteringSaidAn offset determining means for obtaining an offset of the output value based on the slip amount obtained based on the output shaft rotation-related speed after the filter processing is provided.
[0031]
In this case, the slip amount is obtained from the input shaft rotation-related speed after the filter processing and the output shaft rotation-related speed after the filter processing, and the offset is derived based on this.
For example, as the input shaft rotation-related speed after the filter processing, using Noflt that is the input shaft rotation speed subjected to the above-described noise removal processing and Ntflt that is the output shaft rotation speed from which the noise component is removed, The slip amount is obtained, and the offset is obtained based on this amount.
[0032]
In this way, since the fluctuation of the slip amount used for offset determination is suppressed, the influence at the time of taking in can be eliminated.
Further, when the offset is obtained at the start of the slip amount FB control, a threshold value used for the slip start determination can be used.
[0033]
  Now, claims1As described in
Based on the slip amount determined based on the post-filter processing input shaft rotation-related speed and the post-filter processing output shaft rotation-related speed, the end determination of the slip amount feedback control is executed.
  That meansEnd determination of slip amount feedback control based on the slip amount used to determine the offsetButExecutionBe done.
  In this case, since the control structure used for the offset derivation is necessary for the slip amount FB control, the control structure is used as it is, and the above-described claims are made.1The end determination can be performed using the slip amount used in the slip amount FB control without performing the determination with the slip amount different from the slip amount used in the FB control as shown in FIG.
[0034]
Now, in the configuration described so far, only the requirements regarding the automatic transmission have been described, but a fluid type power transmission mechanism is provided on the front stage side of this transmission, and a lockup clutch is further provided in parallel therewith. There is something.
[0035]
  That is, the claim4As described in
  It is arranged in parallel with a fluid type power transmission mechanism that transmits the output of the power source of the vehicle to the automatic transmission and can be in an engaged state or a state other than the engaged state, and at least in the engaged state Lockup clutch control means for controlling a lockup clutch that transmits the output of a power source to the automatic transmission to either the engaged state or a state other than the engaged state according to the driving state of the vehicle; However, in this configuration, the load (in other words, the inertia of the input shaft of the automatic transmission) when the automatic transmission is viewed from the power source side of the vehicle, It changes depending on whether it is in the engaged state or not.
[0036]
Therefore, when the gain and phase characteristics of the feedback controller in the present application are adapted to only one of the states of the lockup clutch, appropriate control cannot be realized.
Accordingly, the configuration is such that the gain and phase characteristics of the feedback controller are switched depending on whether or not the lock-up clutch is in an engaged state, thereby enabling slip amount control suitable for each state. realizable.
[0037]
  Now, the above claims4In the structure provided with the lock-up clutch according to claim 1,5In the state where the lock-up clutch is not engaged, notch filter means for performing notch filter processing on the input value is provided,
  It is preferable that the slip amount is obtained based on the input shaft rotation speed after the notch filter processing, and the feedback controller works based on the slip amount.
[0038]
When a lockup clutch is provided, it is necessary to perform appropriate control according to the engaged state and the state other than the engaged state, and it is necessary to appropriately cope with the pseudo inertia when the engine side is viewed from the transmission. Although the vibration component having a specific frequency that may be used without engaging the lockup clutch is removed by the notch filter means, appropriate slip amount FB control can be realized.
[0039]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a shift control apparatus for an automatic transmission for a vehicle according to the present invention will be described with reference to the drawings.
[0040]
FIG. 1 schematically shows an example in which the shift control device for an automatic transmission is mounted on a vehicle.
The vehicle includes an engine 10 as a prime mover (vehicle power source), a fluid torque converter 20 with a lock-up clutch, an automatic transmission 30, and oil supplied to the torque converter 20 and the automatic transmission 30. The engine 10 includes a hydraulic control circuit 40 for controlling the pressure (hydraulic pressure) and a shift control device 50 that gives a control instruction signal to the hydraulic control circuit 40, and the torque generated by the engine 10 that is increased or decreased by operating an accelerator pedal (not shown). Is transmitted to the drive wheels via a torque converter 20 with a lock-up clutch, an automatic transmission 30, a differential gear device (differential gear) (not shown), and the like.
[0041]
As shown in FIGS. 1 and 2, the lockup clutch-equipped torque converter 20 includes a fluid transmission mechanism 21 that transmits the power generated by the engine 10 to the automatic transmission 30 via a fluid (hydraulic fluid), The lockup clutch mechanism 22 is connected to the fluid transmission mechanism 21 in parallel.
[0042]
The fluid transmission mechanism 21 is rotated by a pump impeller 21a connected to a torque converter input shaft 12 that rotates integrally with a crankshaft of the engine 10, and a flow of hydraulic oil generated by the pump impeller 21a. A turbine impeller 21b connected to the input shaft 31 of the automatic transmission 30 and a stator impeller 21c (not shown in FIG. 1) are included.
[0043]
As shown in FIG. 2, the lock-up clutch mechanism 22 includes a lock-up clutch 22a. When the hydraulic oil is supplied by the connected hydraulic control circuit 40, the lock-up clutch mechanism 22 and the torque converter input shaft 12 are automatically shifted. An engagement state in which the input shaft 31 of the machine 30 is mechanically coupled with the lock-up clutch 22a to rotate them integrally, and a non-engagement state in which the mechanical coupling by the lock-up clutch 22a is released. And a slip state in which the lockup clutch is slipping between the engaged state and the non-engaged state can be achieved.
[0044]
The automatic transmission 30 achieves six forward speeds and one reverse speed, and as shown in FIG. 2, the first row of single pinion planetary gears G1 having the ring gear R1 and the second row of single gears. A pinion planetary gear G2 and a third row single pinion planetary gear G3 are provided, and friction clutches C1, C2, and C3 and friction brakes B1 and B2 are provided as friction engagement elements.
The relationship between the engaged / released state of each friction engagement element in the automatic transmission 30 and the shift speed achieved is as shown in Table 1 below.
In Table 1, ◯ indicates the engaged state, and the blank indicates the released state.
[0045]
[Table 1]

[0046]
As shown in FIG. 1, the hydraulic control circuit 40 includes three on / off solenoid valves 41 to 43 and four linear solenoid valves 44 to 47 controlled by a control instruction signal from the speed change control device 50. The oil supply / discharge of the friction engagement element of the automatic transmission 30 is controlled based on the combination of the on / off solenoid valves 41 to 43, and the linear solenoid valves 44 to 46 are driven to The pressure (hydraulic pressure) of the oil to be supplied / discharged can be adjusted within the range below the line pressure.
[0047]
Further, the hydraulic pressure supplied to and discharged from the lockup clutch mechanism 22 by driving the linear solenoid valve 47 can be adjusted within the range of the line pressure or less. The clutch mechanism 22 is also controlled by the transmission control device 50. Therefore, the device 50 constitutes a lockup clutch control means.
[0048]
The speed change control device 50 is a microcomputer including a CPU, a memory (ROM, RAM), an interface, etc., not shown, and includes a throttle opening sensor 61, an engine speed sensor 62, and an input shaft (turbine) rotation. It is connected to a speed sensor 63 and an output shaft rotation speed sensor 64, and inputs signals generated by these sensors 61 to 64.
[0049]
The throttle opening sensor 61 is provided in the intake passage of the engine 10 to detect the opening of the throttle valve 11 that is opened and closed in response to an operation of an accelerator pedal (not shown), and generates a signal representing the throttle opening Th. It has become.
The engine rotational speed sensor 62 constitutes engine rotational speed detecting means for detecting the rotational speed of the engine 10 and generating a signal representing the engine rotational speed Ne.
[0050]
The input shaft rotational speed sensor 63 constitutes input shaft rotational speed detecting means for detecting the rotational speed of the input shaft 31 of the automatic transmission and generating a signal representing the input shaft rotational speed (turbine rotational speed) Nt. .
[0051]
The output shaft rotational speed sensor 64 detects the output shaft rotational speed No (output rotational speed) of the output shaft 32 of the automatic transmission, and outputs a signal indicating the output shaft rotational speed (that is, a value proportional to the vehicle speed) No. The generated output shaft rotation speed detection means is constituted.
[0052]
The shift control device 50 stores a shift map constituted by the output shaft rotational speed No and the throttle opening Th and a lockup clutch operation map in the memory, and is detected as the detected output shaft rotational speed No. When the point determined by the throttle opening Th crosses the shift line shown in the shift map, the on / off solenoid valves 41 to 43 and the linear solenoid valves 44 to 46 of the hydraulic control circuit 40 are controlled, as shown in Table 1 above. As shown, the engagement / release state of the friction engagement element is changed, and the point determined by the detected output shaft rotational speed No and the detected throttle opening Th is shown in FIGS. When crossing the lock-up line of the lock-up clutch operation map shown in FIG. 3 (B), the linear solenoid valve 47 is controlled to lock the lock-up clutch. It is adapted to change the engagement and disengagement states of 22a.
[0053]
More specifically, FIG. 3 shows the lockup clutch operating lines for each shift stage when the lockup clutch is in the released state and when the lockup clutch is in the engaged state.
[0054]
For example, when the lockup clutch is in the disengaged state and the shift speed is the second speed, a point (operating state point) determined by the actual throttle opening Th and the actual output shaft rotational speed No is shown in FIG. When the leftmost lockup clutch operating line is crossed from left to right, the lockup clutch is changed to the engaged state.
[0055]
Further, when the operating state point enters the hatched area across the lock-up clutch operating line from FIG. 3A from left to right, the lock-up clutch is changed from the released state to the slip state. The
[0056]
On the other hand, once the lockup clutch is changed to the engaged state, the lockup clutch operation line in FIG. 3B is selected.
For example, if the lockup clutch is in an engaged state when the shift speed is the second speed, the operation state point changes from the lockup latch operating line shown by the broken line at the left end of FIG. When crossed, the lockup clutch is changed from the engaged state to the released state.
[0057]
Next, clutch-to-clutch control performed by the shift control device of the automatic transmission configured as described above when shifting from the second speed to the third speed will be described.
The explanation will be made from the outline of clutch-to-clutch control.
[0058]
(Overview)
An outline of hydraulic control at the time of shifting from the second speed to the third speed will be described with reference to FIGS. 4 (A) to 4 (E).
In FIG. 4A, a solid line and a broken line indicate a command hydraulic pressure (hereinafter referred to as “release-side command pressure”) for the disengagement side frictional engagement element (brake B1) and an engagement side frictional engagement element (clutch C3). Indicated hydraulic pressure (hereinafter referred to as “engagement-side instructed pressure”).
[0059]
In FIG. 4B, the solid line and the broken line indicate the actual hydraulic pressure for the release side frictional engagement element (hereinafter referred to as “release side hydraulic pressure”) and the actual hydraulic pressure for the engagement side frictional engagement element (hereinafter, "Engagement side hydraulic pressure").
[0060]
At time t1, when the point determined by the output shaft rotational speed No and the throttle opening Th crosses the shift-up shift line from the second speed to the third speed, the shift control device 50 rapidly decreases the release side hydraulic pressure from the line pressure PL. Further, after a lapse of a predetermined time (after completion of the precharge of the engagement side clutch), the pressure is decreased at a predetermined rate (release initial ramp control). Accordingly, as shown in FIGS. 4A and 4E, the release side frictional engagement element starts to slip at time t3.
[0061]
Next, the transmission control device 50 performs slip amount FB control described later. As a result, as shown in FIG. 4E, the slip amount rises smoothly from time t3 to t4.
[0062]
On the other hand, on the engagement side, the transmission control device 50 performs precharge control for rapidly increasing the engagement side hydraulic pressure for a predetermined time from the time t1, and when the precharge control is terminated at the time t2, until the slip starts. Engagement standby pressure control is performed to maintain the combined hydraulic pressure at a constant value.
Then, when the slip starts at the time t3, the ramp pressure increase control for maintaining the engagement side hydraulic pressure at a predetermined shelf pressure is started. As a result, the engagement side frictional engagement element starts to transmit torque, and the slip amount starts to decrease.
At this time, the shift control device 50 attempts to maintain the slip amount at the target slip amount by the slip amount FB control, and therefore decreases the release side hydraulic pressure in an attempt to increase the slip amount.
[0063]
When this state continues and the slip amount disappears at time t5, the shift control device 50 immediately reduces the release side hydraulic pressure to “0” (ramp release control) and also changes the engagement side hydraulic pressure to the rate of change of the input shaft rotational speed Nt. Inertia FB control is executed to control ΔNt to be a predetermined target rotation change rate ΔMNt.
[0064]
At time t6, when the input shaft rotational speed Nt matches the product of the gear ratio G2 after the shift (in this case, the third speed) and the output shaft rotational speed No (ie, in FIG. 4C, Nt = No · G2 Then, the engagement side hydraulic pressure is increased to the line pressure PL.
Thus, the clutch-to-clutch shift is completed.
[0065]
(Configuration of slip amount FB control system)
Regarding slip amount FB control: 1. Control start determination; 2. Slip amount FB control, The description will be made in the order of the control end determination.
[0066]
1. Slip start judgment
FIG. 5 is a block diagram of slip amount calculation used when the start determination of the slip amount FB control is performed.
As shown in the figure, in this determination, a temporary slip amount Slip = Nt−No · G1 is obtained based on the input shaft rotational speed Nt, the output shaft rotational speed No, and the gear ratio before shifting G1, and this is used for start determination. Processing is performed by a low-pass filter LPF (10 Hz LPF).
Here, the start determination LPF is 10 Hz.
[0067]
The slip amount Slipflt after the start determination LPF processing obtained in this way is a predetermined threshold value [n₁If the rotation exceeds [Rotation], it is determined that slip has occurred, the time t3 described above is set, and the slip amount FB control of the present application is started.
[0068]
2. Slip amount FB control
This control is executed between the above-described times t3 to t5.
The control is performed so as to achieve a substantial target slip amount generated by the reference model M (s), and is configured to perform PI feedback control, and an error factor is also added. Further, based on the input shaft rotational speed No and the output shaft rotational speed Nt, the slip amount Slip is calculated, and the case where the lockup clutch is in a state other than the engaged state and the case where it is in the engaged state is targeted. A structure capable of controlling in accordance with both states is employed.
[0069]
The control block is shown in FIG. Hereinafter, each control element will be described in order.
I Normative model M (s)
This normative model M (s) can be regarded as shown in FIG. 8, and as shown in FIG. 9, when the target slip amount RSlip changing stepwise from 0 to a predetermined value rs is given as an input, An ideal slip amount MDLout that does not cause a shift shock and outputs the ideal slip amount MDLout that reaches the predetermined value rs after a gradual gradual change as time passes and a time determined by the value tr is output. ) Is determined using a “binary model”.
Specifically, the reference model M (s) is represented by the following formula 1.
In the following mathematical formulas including Formula 1, “s” represents a differential operator.
[0070]
[Expression 1]
M (s) = 1 / (tr · s + 1)²
[0071]
B Control object P (s)
The control target P (s) is an automatic transmission that is determined using a system identification method with the input as the release side hydraulic pressure (engagement pressure of the brake B1) and the output as the actual slip amount (actual slip amount Slip). The overall transfer function.
[0072]
In the present embodiment, as shown in the control block diagram of FIG. 6, the reference model M (s), the feedback controller Cpi (s), the control target P (s), the first low-pass filter LPF1, the notch filter NF, A closed loop system is constructed by the Nt offset determining unit NTOFS, the switching unit SW, the second low-pass filter LPF2, the gear ratio multiplier AMP, the No offset determining unit NOOFS, and the error feedback controller Cef.
[0073]
The feedback controller Cpi (s) is a proportional-plus-integral controller (PI controller) whose target input value is the output MDLout of the reference model M (s).
The feedback controller Cpi (s) is expressed by the following formula 2.
[0074]
[Expression 2]
Cpi (s) = Kp + Ki / s
[0075]
The proportional gain (proportional sensitivity) Kp and the integral gain (integral sensitivity) Ki in Equation 2 are obtained by experiments as follows.
That is, the feedback system shown in FIG. 10 is configured for the control object P (s). This feedback system is a system obtained by removing the reference model M (s), the notch filter NF, the Nt offset determination unit NTOFS, the switching unit SW, and the error feedback controller Cef from the system shown in FIG.
As a result, the feedback control amount Slipon input to the feedback controller Cpi (s) is the amount shown in the following equation (3).
[0076]
[Equation 3]
Slip = Slipon = Ntf1t−Noflt · G1 + Nosa
[0077]
  here,
  Ntflt is a low-pass filter process obtained by performing a first low-pass filter process on the input shaft rotational speed Nt, which is one of the outputs of the control target P (s), to remove frequency components of a first frequency [for example, 20 Hz] or higher. This is the input shaft rotation speed. This first low-pass filter constitutes the input value processing means referred to in the present application, and Ntflt is the input shaft after filtering.rotationRelevant speed.
[0078]
Noflt is obtained by subjecting the output shaft rotational speed No, which is one of the outputs of the control target P (s), to a second low-pass filter process that removes a frequency component of a second frequency lower than the first frequency [eg, 1 Hz] or higher. The output shaft rotation speed after filtering.
[0079]
Nosa is obtained by the No offset determination unit NOOFS based on the following equation at the start of the slip amount FB control by gradually lowering the release side frictional engagement element. This part constitutes the offset determining means of the present application.
[0080]
[Expression 4]
Nosa = Ntflt-Noflt G1-n₁
Where n₁Is a slip start determination threshold value.
[0081]
G1 is a gear ratio before the shift of the gear stage before the clutch-to-clutch shift, and is multiplied by the multiplier AMP.
Here, the second low-pass filter LPF2 and the multiplier AMP constitute output value processing means referred to in the present application. Noflt · G1 is the output shaft rotation-related speed after filtering.
[0082]
Therefore, the control gain (proportional gain Kp and integral gain Ki) related to the feedback controller Cpi (s) is the target slip amount when the target slip amount exceeds a predetermined value when the lockup clutch is engaged. Is obtained as a proportional gain Kp and an integral gain Ki that enable feedback control (servo) without causing the slip amount to oscillate and diverge. In this way, the feedback controller Cpi (s) is determined.
[0083]
C Notch filter NF
Referring to FIG. 6 again, the notch filter NF has a gain in a frequency band near a specific frequency (referred to as “notch frequency” in this specification) as shown in FIG. Is a filter that removes frequency components near the notch frequency contained in the input signal.
This notch frequency is. When the lockup clutch is in a state other than the engaged state (for example, a released state and a slip state, that is, a state other than the fully engaged state), the feedback controller Cpi (s) determined as described above is used. In addition, when the clutch-to-clutch shift is performed with the slip amount as the feedback amount as the slip amount Slipon, the frequency is near the center frequency of the vibration generated at the input shaft rotational speed Nt.
[0084]
The notch filter receives the output after the first low-pass filter LPF1 process, and performs notch filter processing on Ntflt from which the frequency component equal to or higher than the first frequency included in the input shaft rotational speed Nt has been removed. The filtered input shaft rotational speed NtNotch is output.
[0085]
D Nt offset determination unit
The Nt offset determination unit NTOFS is for determining an offset Ntsa for compensating a delay of the post-notch filter processed input shaft rotational speed NtNotch with respect to the input shaft rotational speed Ntflt generated by the notch filter NF. This offset Ntsa is obtained by the following equation shown in Equation 5.
[0086]
[Equation 5]
Ntsa = Ntflt-NtNotch
[0087]
E Switching unit SW
When the lockup clutch is in the engaged state (fully engaged state), the switching unit SW is a low-pass filter as a value corresponding to the input shaft rotational speed for obtaining the slip amount (control slip amount) used for control. After processing, the input shaft rotation speed Ntflt is selected. As a result, the slip amount for control becomes the slip amount Slipon represented by the above equation 3.
[0088]
Further, when the lockup clutch is in a state other than the engaged state, the switching unit SW sets the Nt offset to the input shaft rotational speed NtNotch after the notch filter processing as a value corresponding to the input shaft rotational speed for obtaining the control slip amount. Select the value with Ntsa added. As a result, the slip amount Slip becomes the slip amount Slipoff represented by the following equation (6).
[0089]
[Formula 6]
Slip = Slipoff
= NtNotch + Ntsa-Nof1t · G1 + Nosa
[0090]
F Error feedback controller Cef
The error feedback controller Cef receives an error err = MDLout−Slip obtained by subtracting the slip amount from the output MDLout of the reference model M (s), and multiplies the error err by a gain TT to obtain an output EFBout. The output of the controller Cef is superimposed on the input of the feedback controller Cpi (s).
[0091]
The controller Cef (in the example of FIG. 6, gain TT) is determined so as to actually control the slip amount of the automatic transmission based on the system shown in FIG. 6 so that the control slip amount does not diverge. Keep it.
With the above configuration, the slip amount Slip is determined so as to vary depending on the engagement state of the lockup clutch, and the transmission torque of the disengagement side frictional engagement element (so that the slip amount matches the output MDLout of the reference model) The release side command pressure) is controlled, and the slip amount feedback control is performed.
[0092]
3 Slip end judgment
The slip amount calculation block for executing the slip end determination is shown in FIG.
In this block, the feedback controller Cpi (s) and the feedback path are removed from the system shown in FIG. 10, and the slip amount represented by the following equation 7 is used to determine the end of the slip amount FB control. To do.
[0093]
[Expression 7]
Slip = Ntflt−Noflt · G1 + Nosa
[0094]
When the slip amount for completion determination thus obtained exceeds a predetermined threshold value (for example, 0 rotation) (shift to the minus side), the shift to the inertia phase is determined, and the time t5 described above is determined. Is set, and the slip amount FB control is terminated.
Also in this case, the slip amount used for the determination is a filter processed.
[0095]
In the above configuration, the controller shown in FIG. 6 can be regarded as a 3-input 1-output system that receives RSlip, Nt, and No and obtains a controller output for P (s).
Then, by a known method, the gain / phase characteristics of the controller can be obtained for the engagement state of the lockup clutch and states other than the engagement state so that the control is optimized. As a result, suitable clutch-to-clutch control can be realized for both of these states.
[0096]
FIG. 12 shows the FB control start and end times when the control structure of the present application is adopted and the slip amount FB control is performed. It was possible to judge the start and end of the slip.
[0097]
(Specific operation)
Next, a specific operation in the clutch-to-clutch shift of the shift control device of the automatic transmission will be described taking a shift from the second speed to the third speed as an example.
FIG. 13 shows this processing required in the control, FIG. 14 shows the release side hydraulic control, FIGS. 15 and 16 show the slip amount FB control, and FIG. 17 shows the flow in the engagement side hydraulic control. It is.
[0098]
1 Processing
The CPU of the speed change control device 50 is a process of executing initialization at step 1300 and repeating the process at a predetermined sampling time (every 5 msec in the illustrated example) as shown at step 1305. That is, as shown in step 1335, this process is repeated as long as the power is not turned off.
[0099]
In step 1310, the input shaft rotational speed (turbine rotational speed) Nt and the output shaft rotational speed (output rotational speed) No required for control are taken.
In step 1315, the actual slip amount is calculated as Slip = Nt−No · G1.
[0100]
In step 1320, the actual slip Slip obtained in step 1315 is subjected to low-pass filter processing for FB system start determination. The processing is performed according to the equation shown in the figure. Here, the subscript n or the like indicates a sampling value such as n-th (hereinafter the same). A1, b1, and b2 shown in the equation are numerical values for determining the cutoff frequency. The slip amount after 10 Hz LPF processing obtained by this processing can be used to determine the start of the slip amount FB control.
[0101]
In step 1322, low-pass filter processing is applied to the input shaft rotational speed Nt. In this process, the cutoff frequency is selected to be 20 Hz. g1, h1, and h2 are numerical values for determining the cutoff frequency. By this process, the input shaft rotation speed Ntflt after the filter process from which a predetermined high frequency component is removed is obtained.
[0102]
In step 1325, notch processing of the input shaft rotational speed (turbine rotational speed) Nt is performed according to the equation shown in the figure.
In the equation, c1, c2, d1, d2, and d3 are numerical values for determining the notch cutoff frequency. Specifically, this cutoff frequency is 7 Hz.
In this equation, the input shaft rotational speed Ntflt to be subjected to notch processing is a physical quantity that has been processed by the first low-pass filter LPF1 described above. In this process, the previous (n−1) and the previous (n−2) Ntflts are also taken into account.
[0103]
In step 1330, a low-pass filter process is applied to the output shaft rotational speed (output rotational speed) No. In this process, the cut-off frequency is selected to be 1 Hz. e1, f1, and f2 are numerical values for determining the cutoff frequency. By this process, the output shaft rotation speed Noflt after the filter process from which the predetermined high-frequency component is removed is obtained.
[0104]
After passing through these pre-processing, the slip amount FB control shown in FIGS.
[0105]
2 Slip amount FB control
B FB control start processing
When the slip amount Slipflt obtained in step 1320 of the flow shown in FIG. 13 exceeds the predetermined threshold value n1, it is determined that slip has started, and slip amount FB control is entered.
The flow of this slip amount FB control is shown in FIGS.
[0106]
B Slip amount FB control
In steps 1505 and 1510, the feedback initial value P is stored, and the proportional gain Kp, the integral gain Ki, and the error feedback gain TT are read.
[0107]
In step 1515, the above-described offsets Ntsa and Nosa are calculated.
That is, when the slip start determination is made, the offset Nosa of the output shaft rotational speed Noflt after the 1 Hz LPF process is obtained from the following equation similar to the equation 4 shown above.
[0108]
[Equation 8]
Nosa = Ntflt-Noflt G1-n₁
Where n₁  Is a slip start determination threshold value.
[0109]
As a result, No · G1 at the time of the slip determination is a value lower than the input shaft rotation speed Nt by a threshold value, so that the output shaft rotation speed offset Nosa is acquired based on the input shaft rotation speed Ntflt. It becomes.
[0110]
At the same time, an offset Ntsa between the input shaft rotation speed Ntflt and the input shaft rotation speed NtNotch after the notch filter processing is also acquired.
Also in this case, the input shaft rotational speed Nt is set to the input rotational speed after the low pass filter processing by the LPF 1 as described above.
[0111]
[Equation 9]
Ntsa = Ntflt-NtNotch
[0112]
Thereafter, the slip amount FB control is executed from step 1520 to step 1570.
In step 1520, the target slip amount RSlip is read.
[0113]
Next, the process proceeds to steps 1525, 1530, and 1535. As described above, in the present application, the actual slip amount Slip used for the feedback varies depending on the engagement state of the lockup clutch.
Therefore, in step 1525, the engagement state of the lockup clutch is determined. If the lockup clutch is in the engagement state, the process proceeds to step 1530. Otherwise, the process proceeds to step 1535.
[0114]
In steps 1530 and 1535, the actual slip amount Slip used for the control is obtained according to the following equation in accordance with each situation.
[0115]
In step 1530, the actual slip amount Slip is calculated from the 20 Hz LPF-processed input shaft rotation speed Ntflt and the output shaft rotation speed No offset Nosa obtained above and the 1-Hz LPF-processed output shaft rotation speed Noflt, and the FB control is executed. To do.
[0116]
[Expression 10]
Slip = Ntflt−Noflt · G1 + Nosa
[0117]
In step 1535, the actual slip amount Slip is calculated from the input shaft rotational speed NtNotch subjected to the notch filter processing and the offset Ntsa of the input shaft rotational speed Nt obtained above, and FB control is performed.
[0118]
## EQU11 ##
Slip = NtNotch + Ntsa-No · G1 + Nosa
[0119]
The process in step 1540 is a normative model calculation process, which is a process according to the mathematical formula shown.
In the equation, MDLout (n) indicates the reference model output value, and the suffixes n, n-1, n-2, etc. indicate sampling at each stage, and a1, a2, b1, b2, b3 is a value set according to the model.
[0120]
In step 1545, error feedback calculation is performed.
In this calculation, EFBout is an error feedback output, MDLout is an output obtained by the above-described normative model calculation, and TT is a proportional gain used for the error described above.
[0121]
In step 1550, the PI control input value PIin is calculated.
PIin is obtained as a difference between the sum of MDLout and EFBout and the actual slip amount Slip.
[0122]
As shown in FIG. 16, in step 1555, the PI control output PIout is calculated according to the equation shown. Even in this calculation, n and the like mean a sampling value at the nth time and SMPLT is a sampling time.
[0123]
In step 1560, a pressure upper and lower limit check is executed.
[0124]
In step 1565, the actual step amount Slip is calculated.
Here, the actual slip amount is the slip amount obtained by the processing shown in FIG. Specifically, Slip = Ntflt−Noflt · G1 + Nosa.
[0125]
C Slip amount FB control end
The slip end determination is performed by using the slip amount obtained in step 1565, as shown in step 1570, regardless of whether the lock-up clutch is engaged or not. In order to prevent this, the slip amount is calculated using the slip amount using the Nt, No rotation speed that has passed through the low-pass filter, and the FB control is terminated when the slip amount falls below a predetermined threshold value.
As a result, even when noise is superimposed on the output shaft rotation speed, slip start determination and slip FB control can be performed without being affected by noise.
[0126]
3 Transition to inertia phase
Thereafter, as shown in step 1580, the lamp open flag is set and the process proceeds to the next phase (inertia phase).
[0127]
4 Open side hydraulic control and engagement side hydraulic control
These hydraulic controls include slip amount FB control targeted by the present application in the predetermined steps, and execute the controls in a predetermined order shown in FIG.
The opening side hydraulic control shown in FIG. 14 will be described. According to a predetermined start condition, the opening initial ramp control shown in step 1410 (t1 to t3 in FIG. 4) is executed, and in step 1420, the presence or absence of the start of slip is determined. If the slip has been started, the slip amount FB control according to the present application is executed in step 1450, and if the slip has not been started, the forced slip start control for executing pressure reduction or the like is executed in step 1440. The start of slip is determined, and the slip amount FB control in step 1450 is executed.
Then, when the slip amount FB control is completed, the routine proceeds to step 1460, where the ramp opening control is executed, a series of shift operations are completed, and the next shift waiting state is entered.
[0128]
On the other hand, regarding the hydraulic control on the engagement side shown in FIG. 17, the preparation process on the engagement side is performed in step 1610, the precharge control is performed in step 1620, and the occurrence of slip is waited at the engagement standby pressure in step 1630. Engagement standby control is executed.
In step 1640, with the ramp pressure increase control, in step 1650, the inertia phase start determination corresponding to the completion point of the previous slip amount FB control is executed, and when the inertia phase is established, the inertia phase FB control in step 1660 is performed. Migrate to
[0129]
Further, in this control state, the transmission gear ratio determination (determination of Nt = No · G2 shown in FIG. 4) shown in step 1670 is repeated, and when this condition is satisfied, the shift end processing is performed.
[0130]
[Another embodiment]
UpIn the embodiment described above, in order to execute the low-pass filter processing, the frequency component of 10 Hz or more is removed, but the lower limit frequency is selected within the frequency range of 7 to 13 Hz depending on the purpose. Is preferable for a shift control device of an automatic transmission.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram when a shift control device for an automatic transmission according to the present invention is mounted on a vehicle.
FIG. 2 is a skeleton diagram of the automatic transmission shown in FIG.
FIG. 3A is a lockup clutch operation map during acceleration;
(B) is a diagram showing a lock-up clutch operation map during deceleration
FIG. 4A is a control command value of a release side command pressure and an engagement side command pressure at the time of shifting,
(B) is the actual disengagement side hydraulic pressure and engagement side hydraulic pressure at the same speed change,
(C) is the engine speed and the input shaft speed at the same speed change,
(D) is the output torque at the same shift,
(E) is a time chart showing the actual slip amount at the same speed change.
FIG. 5 is a block diagram of a slip amount calculation used for a slip amount FB control start determination.
FIG. 6 is a control block diagram of slip amount FB control.
FIG. 7 is a block diagram of the slip amount calculation used for the slip amount FB control end determination.
FIG. 8 is a block diagram of the reference model
9 is a time chart showing the target slip amount input to the reference model shown in FIG. 8 and the output of the reference model for this input.
10 is a block diagram showing a feedback system used to determine the feedback controller shown in FIG. 6;
FIG. 11 is a Bode diagram of a notch filter.
FIG. 12 is a diagram illustrating an operation state when the start / end determination of the slip amount FB control of the present application is performed.
FIG. 13 is a flowchart of this processing executed by the CPU of the speed change control device shown in FIG. 1;
FIG. 14 is a flowchart of a program (release side hydraulic control routine) executed by the CPU of the speed change control device shown in FIG. 1;
15 is a flowchart of a program (slip amount FB control routine) executed by the CPU of the speed change control device shown in FIG. 1;
FIG. 16 is a flowchart of a program (slip amount FB control routine) executed by the CPU of the speed change control device shown in FIG. 1;
17 is a flowchart of a program (engagement hydraulic control routine) executed by the CPU of the speed change control device shown in FIG.
FIG. 18 is a diagram showing a state of slip amount FB control including a conventional problem.
FIG. 19 is an explanatory diagram when 1/8 annealing is performed.
FIG. 20 is a diagram showing an offset loading status and its problems.
[Explanation of symbols]
10 ... Engine,
12 ... Torque converter input shaft,
20 ... Fluid type torque converter with lock-up clutch,
21 ... Fluid power transmission mechanism,
22 ... Lock-up clutch,
30 ... automatic transmission,
31 ... Input shaft,
32 ... Output shaft,
40 ... Hydraulic control circuit,
41-43 ... On / off solenoid valve,
44 to 47: linear solenoid valve,
50 ... Control device,
63 ... Input shaft rotational speed sensor,
64 ... output shaft rotational speed sensor,
M (s) ... normative model,
P (s): Control target,
Cpi (s) ... PI controller,
NF ... Notch filter,
LPF1 ... first low-pass filter,
LPF2: Second low-pass filter.

Claims (5)

Maintaining each of the plurality of friction engagement elements in an engaged state or a released state to achieve a predetermined shift stage. When shifting from one shift stage to another shift stage of an automatic transmission, engage before the shift. The engagement side which is in the released state before the shift and is in the engaged state after the gear shift is generated by reducing the transmission torque by the release side frictional engagement element which is in the released state after the gear shift. A shift control device for an automatic transmission having clutch-to-clutch control means for increasing the transmission torque by the friction engagement element and performing the same shift,
The clutch-to-clutch control means is
Input shaft rotational speed acquisition means for acquiring an input value according to the input shaft rotational speed of the automatic transmission; and Output shaft rotational speed acquisition means for acquiring an output value according to the output shaft rotational speed of the automatic transmission. Prepared,
A feedback controller for controlling a transmission torque by the disengagement side frictional engagement element so that a control slip amount obtained based on the input value and the output value is equal to a predetermined target slip amount;
The start-size constant control by the feedback controller is determined from the output value and the input value, and performs, based on the slip amount that has been subjected to filtering processing and for a predetermined first band,
Input value processing means for applying a filtering process to a predetermined second band set separately from the first band to give the input shaft rotation-related speed after the filter process to the input value;
The output value is subjected to a low-pass filter process for a predetermined third band set lower than the second band, and a post-filtering output shaft rotation-related speed obtained by multiplying the post-processing value by a gear ratio before shifting. Output value processing means for providing,
A shift control device for an automatic transmission that executes an end determination of slip amount feedback control based on a slip amount obtained based on the post-filter processing input shaft rotation-related speed and the post-filter processing output shaft rotation-related speed . The shift control apparatus for an automatic transmission according to claim 1, wherein the filtering process for the predetermined first band is a low-pass filter process. Before SL based on the slip amount determined based on the filter-processed input shaft associated speed and the filter processed output shaft rotational related speed, according to claim 1 having the offset determination means for determining an offset of the output value Shift control device for automatic transmission. It is arranged in parallel with a fluid power transmission mechanism that transmits the output of the power source of the vehicle to the automatic transmission, and is configured to be in an engaged state or a state other than the engaged state, and at least in the engaged state Lock-up clutch control means for controlling a lock-up clutch that transmits the output of the power source to the automatic transmission to either the engaged state or a state other than the engaged state according to the driving state of the vehicle. With
The shift control of the automatic transmission according to any one of claims 1 to 3 , wherein the gain and phase characteristics of the feedback controller are switched according to whether or not the lockup clutch is in an engaged state. apparatus. A notch filter that performs notch filter processing on the input value in a state where the lock-up clutch is not engaged,
5. The shift control apparatus for an automatic transmission according to claim 4 , wherein slip amount feedback control is performed based on the input shaft rotational speed after the notch filter processing in a state where the lockup clutch is not engaged.

Images