JP3573144B2 - Vehicle driving force control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular driving force control device capable of preventing the generation of shock when disengaging a clutch interposed between a driving source follower and a driving wheel follower during travelling. <P>SOLUTION: If it is determined that output torque of a motor is in course of decreasing during travelling, the clutch is disengaged when the output torque becomes torque corresponding to a torque with which acceleration in a rear wheel side and acceleration in a motor side become equal to each other. <P>COPYRIGHT: (C)2004,JPO

Description

ここで、
Ｖ ：発電機７の電圧
Ｉａ：発電機７の電機子電流
Ｎｈ：発電機７の回転数
Ｋ３：効率
Ｋ２：係数
である。
ステップＳ６０では、下記式に基づき、余剰トルクつまり発電機７で負荷すべき目標の発電負荷トルクＴｈを求め、復帰する。
【００２８】
Ｔｈ ＝ ＴＧ ＋ ＴΔＶＦ
次に、目標トルク制限部８Ｆの処理について、図５に基づいて説明する。
すなわち、まず、ステップＳ１１０で、上記目標発電負荷トルクＴｈが、発電機７の最大負荷容量ＨＱより大きいか否かを判定する。目標発電負荷トルクＴｈが当該発電機７の最大負荷容量ＨＱ以下と判定した場合には、復帰する。一方、目標発電負荷トルクＴｈが発電機７の最大負荷容量ＨＱよりも大きいと判定した場合には、ステップＳ１２０に移行する。
【００２９】
ステップＳ１２０では、目標の発電負荷トルクＴｈにおける最大負荷容量ＨＱを越える超過トルクΔＴｂを下記式によって求め、ステップＳ１３０に移行する。
ΔＴｂ＝ Ｔｈ − ＨＱ
ステップＳ１３０では、エンジン回転数検出センサ２１及びスロットルセンサからの信号等に基づいて、現在のエンジントルクＴｅを演算してステップＳ１４０に移行する。
【００３０】
ステップＳ１４０では、下記式のように、上記エンジントルクＴｅから上記超過トルクΔＴｂを減算したエンジントルク上限値ＴｅＭを演算し、求めたエンジントルク上限値ＴｅＭをエンジンコントローラ１８に出力した後に、ステップＳ１５０に移行する。
ＴｅＭ ＝Ｔｅ −ΔＴｂ
ステップＳ１５０では、目標発電負荷トルクＴｈに最大負荷容量ＨＱを代入した後に、復帰する。
【００３１】
次に、余剰トルク変換部８Ｇの処理について、図６に基づいて説明する。
まず、ステップＳ２００で、Ｔｈが０より大きいか否かを判定する。Ｔｈ＞０と判定されれば、前輪１Ｌ、１Ｒが加速スリップしているので、ステップＳ２１０に移行する。また、Ｔｈ≦０と判定されれば、前輪１Ｌ、１Ｒは加速スリップしていない状態であるので、そのまま復帰する。
【００３２】
ステップＳ２１０では、モータ用回転数センサ２１が検出したモータ４の回転数Ｎｍを入力し、そのモータ４の回転数Ｎｍに応じた目標モータ界磁電流Ｉｆｍを算出し、当該目標モータ界磁電流Ｉｆｍをモータ制御部８Ｃに出力した後、ステップＳ２２０に移行する。
ここで、上記モータ４の回転数Ｎｍに対する目標モータ界磁電流Ｉｆｍは、回転数Ｎｍが所定回転数以下の場合には一定の所定電流値とし、モータ４が所定の回転数以上になった場合には、公知の弱め界磁制御方式でモータ４の界磁電流Ｉｆｍを小さくする。すなわち、モータ４が高速回転になるとモータ誘起電圧Ｅの上昇によりモータトルクが低下することから、上述のように、モータ４の回転数Ｎｍが所定値以上になったらモータ４の界磁電流Ｉｆｍを小さくして誘起電圧Ｅを低下させることでモータ４に流れる電流を増加させて所要モータトルクＴｍ（ｎ）を得るようにする。この結果、モータ４が高速回転になってもモータ誘起電圧Ｅの上昇を抑えてモータトルクの低下を抑制するため、所要のモータトルクＴｍ（ｎ）を得ることができる。また、モータ界磁電流Ｉｆｍを所定の回転数未満と所定の回転数以上との２段階で制御することで、連続的な界磁電流制御に比べ制御の電子回路を安価にできる。
【００３３】
なお、所要のモータトルクＴｍ（ｎ）に対しモータ４の回転数Ｎｍに応じて界磁電流Ｉｆｍを調整することでモータトルクＴｍ（ｎ）を連続的に補正するモータトルク補正手段を備えても良い。すなわち、２段階切替えに対し、モータ回転数Ｎｍに応じてモータ４の界磁電流Ｉｆｍを調整すると良い。この結果、モータ４が高速回転になってもモータ４の誘起電圧Ｅの上昇を抑えモータトルクの低下を抑制するため、所要のモータトルクＴｍ（ｎ）を得ることができる。また、なめらかなモータトルク特性にできるため、２段階制御に比べ車両は安定して走行できるし、常にモータ駆動効率が良い状態にすることができる。
【００３４】
ステップＳ２２０では、上記目標モータ界磁電流Ｉｆｍ及びモータ４の回転数Ｎｍからモータ４の誘起電圧Ｅを算出して、ステップＳ２３０に移行する。
ステップＳ２３０では、上記余剰トルク演算部８Ｅが演算した発電負荷トルクＴｈに基づき対応する目標モータトルクＴｍ（ｎ）を算出して、ステップＳ２４０に移行する。
【００３５】
ステップＳ２４０では、後述のクラッチ解放処理部８Ｈを実行した後に、ステップＳ２５０に移行する。
ステップＳ２５０では、上記今回の目標モータトルクＴｍ（ｎ）及び目標モータ界磁電流Ｉｆｍを変数として対応する目標電機子電流Ｉａを算出して、ステップＳ２６０に移行する。
【００３６】
ステップＳ２６０では、上記目標電機子電流Ｉａから発電機の７の制御指令値となるデューティ比ｃ１を求め、出力した後に復帰する。
ここで、上記余剰トルク変換部８Ｇでは、モータ側の制御を考慮して目標の発電負荷トルクＴｈに応じた発電機７での目標電圧Ｖを算出しているが、上記目標発電負荷トルクＴｈから直接に、当該目標発電負荷トルクＴｈとなる電圧値Ｖを算出しても構わない。
【００３７】
次に、クラッチ解放処理部８Ｈの処理について、図７を参照して説明する。
まず、ステップＳ４１０にて、目標モータトルクが減少中か否かを判定し、減少中と判定した場合には、ステップＳ４２０に移行し、減少中でないと判定した場合には、処理を中止して復帰する。
減少中か否かは、下記のように、前回値と単純に比較して判定しても良い。
【００３８】
Ｔｍ（ｎ） −Ｔｍ（ｎ−１）＜０
ここで、添え字（ｎ−１）は、１演算周期前の目標モータトルクである。
もっとも、ノイズ等の影響を抑えるために、下記のように３周期分以上の目標モータトルクの履歴値に基づいて減少中か否かを判定しても良い（下記式では６周期分の値を使用した例）。また、複数演算周期分だけ連続して目標モータトルク値が減少している場合に、減少中と判定しても良い。
【００３９】
｛Ｔｍ（ｎ）＋Ｔｍ（ｎ−１）＋Ｔｍ（ｎ−２）｝
− ｛Ｔｍ（ｎ−３）＋Ｔｍ（ｎ−４）＋Ｔｍ（ｎ−５）｝ ＜ ０
また、ステップＳ４２０では、今回の目標モータトルクＴｍ（ｎ）が、モータトルク減少率切替閾値Ｔ−ＴＭ１よりも小さいか否かを判定し、小さいと判定した場合には、２輪駆動状態へ移行中としてステップＳ４３０に移行して、モータトルクの減少勾配を一定に設定する。一方、モータトルク減少率切替閾値Ｔ−ＴＭ１と等しいかそれよりも大きいと判定した場合には、ステップＳ４６０に移行する。
【００４０】
ステップＳ４３０では、今回の目標モータトルクＴｍ（ｎ）が、モータトルク低減率切替閾値Ｔ−ＴＭ２よりも小さいか否かを判定し、小さいと判定した場合には、ステップＳ４４０に移行し、そうでない場合には、ステップＳ４５０に移行する。
ステップＳ４４０では、下記式に基づき、通常のトルク低減率ＤＴｍでモータトルクが減少するように設定して、ステップＳ４６０に移行する。
【００４１】
Ｔｍ（ｎ） ＝ Ｔｍ（ｎ−１）−ＤＴｍ
一方、ステップＳ４５０では、下記式に基づき、トルクの減少率が遅くなるように、１より小さなゲインＫ（例えば０．５）を通常のトルク低減率ＤＴｍに乗算して低減率を小さく規制して、ステップＳ４６０に移行する。
Ｔｍ（ｎ） ＝ Ｔｍ（ｎ−１）−ＤＴｍ×Ｋ
なお、１より小さなゲインＫを掛けて低減率を小さく規制しているが、予め設定した所定の低減率で減算しても良い。この規制後の低減率は、モータのトルク制御で追従可能なだけ、つまり実際のトルク値と目標モータトルク（トルク指令値）との差が生じない範囲で、小さな低減率となるように設定する。上記「モータのトルク制御で追従可能な」とは、例えば、実際のトルク値がトルク指令値となるまでの応答の速さよりも遅い低減率に設定する。
【００４２】
なお、ステップＳ４２０とＳ４４０を省略し、ステップＳ４３０からステップＳ４５０に移行したとき、ステップＳ４５０に代わりに、制御されているモータトルクの低減率に所定の最大制限値を掛けて、所定の低減率より大きくならないよう、すなわち、すばやくモータトルクが低下しないようにしても良い。
ステップＳ４６０では、今回の目標モータトルクＴｍ（ｎ）が、クラッチ解放される瞬間のクラッチ入力側の加速度とクラッチ出力側の加速度が略一致する、つまりクラッチでのトルクが略ゼロとなるトルクＴｆ（以下、相当トルクＴｆと呼ぶ）と略一致したか否かを判定し、当該相当するトルクＴｆと略一致したと判定した場合には、ステップＳ４７０で、クラッチ制御部８Ｄを通じてクラッチ解放指令を出力した後に処理を終了する。一方、相当するトルクＴｆと略一致しない場合には、そのまま処理を終了して復帰する。
【００４３】
なお、クラッチ動作の応答遅れ分だけ上記相当トルクＴｆを補正しておくことが好ましい。
ここで、上記モータトルク減少率切替閾値Ｔ−ＴＭ１、モータトルク低減率切替閾値Ｔ−ＴＭ２、及び相当トルクＴｆについて説明する。この３つの値は、下記のような関係にある。
【００４４】
Ｔ−ＴＭ１ ＞ Ｔ−ＴＭ２ ＞ Ｔｆ
上記相当トルクＴｆは、車両加速度やモータ側のトルク伝達経路のフリクションなどに応じて、マップや演算によって算出、若しくは実験で求めた値であって、走行状態に応じてクラッチ１２でのトルクをゼロとするに要するモータトルクである。
【００４５】
この相当トルクＴｆは、「モータ及び減速機のフリクション分のトルク」と「モータ、減速機を後輪の加速度と等しく加速させるためのトルク」との和であると推定される。なお。この相当トルクＴｆは、実験などで定めた固定値であって良い。
モータトルク低減率切替閾値Ｔ−ＴＭ２は、上記相当トルクＴｆより大きく且つ当該相当トルクＴｆに近いトルク値であって、モータ制御のシステムが追従応答可能なだけ上記相当トルクＴｆよりも大きな値である。
【００４６】
また、モータトルク減少率切替閾値Ｔ−ＴＭ１は、４輪駆動状態から２輪駆動状態に移行中の状態と想定されるトルク値である。
ここで、上記クラッチ解放処理部８Ｈ、クラッチ制御部８Ｄは、クラッチ解放処理部を構成する。
次に、エンジンコントローラ１８の処理について説明する。
【００４７】
エンジンコントローラ１８では、所定のサンプリング時間毎に、入力した各信号に基づいて図８に示すような処理が行われる。
すなわち、まずステップＳ６１０で、アクセルセンサ４０からの検出信号に基づいて、運転者の要求する目標出力トルクＴｅＮを演算して、ステップＳ６２０に移行する。
【００４８】
ステップＳ６２０では、４ＷＤコントローラ８から制限出力トルクＴｅＭの入力があるか否かを判定する。入力が有ると判定するとステップＳ６３０に移行する。一方、入力が無いと判定した場合にはステップＳ６５０に移行する。
ステップＳ６３０では、制限出力トルクＴｅＭが目標出力トルクＴｅＮよりも大きいか否かを判定する。制限出力トルクＴｅＭの方が大きいと判定した場合には、ステップＳ６４０に移行する。一方、制限出力トルクＴｅＭの方が小さいか目標出力トルクＴｅＮと等しければステップＳ６５０に移行する。
【００４９】
ステップＳ６４０では、目標出力トルクＴｅＮに制限出力トルクＴｅＭを代入することで目標出力トルクＴｅＮを増大して、ステップＳ６７０に移行する。
ステップＳ６７０では、スロットル開度やエンジン回転数などに基づき、現在の出力トルクＴｅを算出してステップＳ６８０に移行する。
ステップＳ６８０では、現在の出力トルクＴｅに対する目標出力トルクＴｅＮのの偏差分ΔＴｅ′を下記式に基づき出力して、ステップＳ６９０に移行する。
【００５０】
ΔＴｅ′ ＝ＴｅＮ − Ｔｅ
ステップＳ６９０では、その偏差分ΔＴｅに応じたスロットル開度θの変化分Δθを演算し、その開度の変化分Δθに対応する開度信号を上記ステップモータ１９に出力して、復帰する。
次に、上記構成の装置における作用などについて説明する。
【００５１】
路面μが小さいためや運転者によるアクセルペダル１７の踏み込み量が大きいなどによって、エンジン２から前輪１Ｌ、１Ｒに伝達されたトルクが路面反力限界トルクよりも大きくなると、つまり、主駆動輪１Ｌ、１Ｒである前輪１Ｌ、１Ｒが加速スリップすると、クラッチ１２が接続されると共に、その加速スリップ量に応じた発電負荷トルクＴｈで発電機７が発電することで、４輪駆動状態に移行し、続いて、前輪１Ｌ、１Ｒに伝達される駆動トルクが、当該前輪１Ｌ、１Ｒの路面反力限界トルクに近づくように調整されることで、２輪駆動状態に移行する。この結果、主駆動輪である前輪１Ｌ、１Ｒでの加速スリップが抑えられる。
【００５２】
しかも、発電機７で発電した余剰の電力によってモータ４が駆動されて従駆動輪である後輪３Ｌ、３Ｒも駆動されることで、車両の加速性が向上する。
このとき、主駆動輪１Ｌ、１Ｒの路面反力限界トルクを越えた余剰のトルクでモータ４を駆動するため、エネルギー効率が向上し、燃費の向上に繋がる。
ここで、常時、後輪３Ｌ、３Ｒを駆動状態とした場合には、力学的エネルギー→電気的エネルギー→力学的エネルギーと何回かエネルギー変換を行うために、変換効率分のエネルギー損失が発生することで、前輪１Ｌ、１Ｒだけで駆動した場合に比べて車両の加速性が低下する。このため、後輪３Ｌ、３Ｒの駆動は原則として抑えることが望まれる。これに対し、本実施形態では、滑り易い路面等では前輪１Ｌ、１Ｒに全てのエンジン２の出力トルクＴｅを伝達しても全てが駆動力として使用されないことに鑑みて、前輪１Ｌ、１Ｒで有効利用できない駆動力を後輪３Ｌ、３Ｒに出力して加速性を向上させるものである。
【００５３】
また、クラッチ１２が接続されて４輪駆動状態となり、続いて加速スリップが抑えられるにつれて、モータトルクが連続して減少して２輪駆動状態に移行する。
このとき、目標モータトルクがモータトルク減少率切替閾値Ｔ−ＴＭ１を越えると、２輪駆動状態へ移行中としてモータトルクの減少率つまり低減率がＤＴｍと一定に設定されて所定の勾配で減少し、さらに、目標モータトルクが相当トルクＴｆと略一致した時点でクラッチ解放指令を出力してクラッチ１２を解放する。このとき、クラッチ１２でのトルクが小さいので、クラッチ解放時にショックが発生することが防止される。
【００５４】
さらに、本実施形態では、相当トルクＴｆとなる前に、目標モータトルクがモータトルク低減率切替閾値Ｔ−ＴＭ２を越えると、モータトルクの減少率つまり低減率を、モータ駆動制御の制御性能上追従可能な小さな値に規制することで、トルク指令値と実トルクのずれを小さく抑える。この結果、クラッチ解放時におけるモータトルク制御性が向上して、より確実に、クラッチ１２でのトルクが小さいモータトルク状態に調整することができ、もって、より確実にクラッチ解放時にショックが発生することを防止できる。
【００５５】
図９にそのタイムチャート例を示す。
この図９から分かるように、相当トルクＴｆに近づいた時点でモータトルクの減少率を故意に遅く設定しても、その時間は短く、また、トルクがＴ−ＴＭ１〜Ｔ−ＴＭ２の間では、トルクの減少率は所望の値に設定可能である。
ここで、上記実施形態では、発電機７の発電した電圧でモータ４を駆動して４輪駆動を構成する場合で説明しているが、これに限定されない。モータ４ヘ電力供給できるバッテリを備えるシステムに採用しても良い。この場合には、バッテリから微小電力を供給するようにすればよいし、さらにはバッテリからの供給と共に発電機７からの電力供給も併行して行うようにしてもよい。
【００５６】
または、上記実施形態では、主駆動源として内燃機関を例示しているが、主駆動源をモータから構成しても良い。
また、上記システムでは、前輪の加速スリップに応じて４輪駆動状態に移行する場合で説明したが、アクセル開度などに応じて４輪駆動状態に移行するシステムであっても適用可能である。
【図面の簡単な説明】
【図１】本発明に基づく実施形態に係る概略装置構成図である。
【図２】本発明に基づく実施形態に係るシステム構成図である。
【図３】本発明に基づく実施形態に係る４ＷＤコントローラを示すブロック図である。
【図４】本発明に基づく実施形態に係る余剰トルク演算部の処理を示す図である。
【図５】本発明に基づく実施形態に係る目標トルク制御部の処理を示す図である。
【図６】本発明に基づく実施形態に係る余剰トルク変換部の処理を示す図である。
【図７】本発明に基づく実施形態に係るクラッチ解放処理部の処理を示す図である。
【図８】本発明に基づく実施形態に係るエンジンコントローラの処理を示す図である。
【図９】本発明に基づく実施形態に係るクラッチ解放のタイムチャートを示す図である。
【符号の説明】
１Ｌ、１Ｒ 前輪
２ エンジン
３Ｌ、３Ｒ 後輪
４ モータ
６ ベルト
７ 発電機
８ ４ＷＤコントローラ
８Ａ 発電機制御部
８Ｂ リレー制御部
８Ｃ モータ制御部
８Ｄ クラッチ制御部
８Ｅ 余剰トルク演算部
８Ｆ 目標トルク制限部
８Ｇ 余剰トルク変換部
８Ｈ クラッチ解放処理部
９ 電線
１０ ジャンクションボックス
１１ 減速機
１２ クラッチ
１４ 吸気管路
１５ メインスロットルバルブ
１６ サブスロットルバルブ
１８ エンジンコントローラ
１９ ステップモータ
２０ モータコントローラ
２１ エンジン回転数センサ
２２ 電圧調整器
２３ 電流センサ
２６ モータ用回転数センサ
２７ＦＬ、２７ＦＲ、２７ＲＬ、２７ＲＲ車輪速センサ
３０ トランスミッション
３１ ディファレンシャル・ギヤ
３２ シフト位置検出手段
３４ ブレーキペダル
３５ ブレーキストロークセンサ（制動操作量検出手段）
３６ 制動コントローラ
３７ＦＬ、３７ＦＲ、３７ＲＬ、３７ＲＲ制動装置
４０ アクセルセンサ（加速指示検出手段）
Ｉｆｈ 発電機の界磁電流
Ｖ 発電機の電圧
Ｎｈ 発電機の回転数
Ｉａ 電機子電流
Ｉｆｍ モータの界磁電流
Ｅ モータの誘起電圧
Ｎｍ モータの回転数（回転速度）
ΔＮｍ モータの回転加速度
ＴＧ 発電機負荷トルク
Ｔｈ 目標発電機負荷トルク
Ｔｈ２ 第２目標発電機負荷トルク
Ｔｍ（ｎ） モータの現在の目標トルク
Ｔｅ エンジンの出力トルク
Ｔ−ＴＭ１ モータトルク減少率切替閾値
Ｔ−ＴＭ２ モータトルク低減率切替閾値
Ｔｆ 相当トルク
ＴＤｍ 低減率[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a driving force control device for a vehicle in which a main driving wheel is driven by a main driving source such as an engine, and in a four-wheel driving state, a sub driving wheel is driven by a sub driving source such as a motor.
[0002]
[Prior art]
Conventionally, as a driving force control device for a vehicle in which a front wheel is driven by an engine and a rear wheel is drivable by a motor, and a clutch and a speed reducer are interposed in a torque transmission path from the motor to the rear wheel shaft, for example, Japanese Unexamined Patent Publication No. There is one described in JP-A-11-243608.
[0003]
In this prior art, when shifting to the four-wheel drive state during traveling, the motor is idled so that the rotation speed of the motor becomes equal to the rotation speed of the axle, and then the clutch is engaged. In addition, the occurrence of a shock when the clutch is engaged is avoided.
[0004]
[Problems to be solved by the invention]
In the above prior art, the difference in rotational speed between the output shaft side and the input shaft side of the clutch is considered to be the cause of the occurrence of shock during the operation of the clutch. According to this technical idea, when the clutch is shifted to the disengaged state, there is naturally no difference in rotation speed between the output shaft side and the input shaft side, so that it is not necessary to perform a process of adjusting the rotation speed, and there is no shock. It is usual to assume that this will not happen.
[0005]
However, in the case of a system in which the drive sources for driving the main drive wheels and the slave drive wheels are separately configured and the slave drive wheels are driven only when necessary, the four-wheel drive state during traveling and the two-wheel drive state When the clutch is changed to the disengaged state after the output of the motor becomes zero at the time of shifting to, there is torque acting on the clutch from the driven wheel side because the vehicle is running. For this reason, although there is no difference in the number of rotations between the clutch input / output shafts, there is a problem that a shock may occur due to the torque acting on the clutch.
[0006]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and prevents occurrence of a shock when a clutch interposed between a sub-drive source and a sub-drive wheel is shifted to a released state during traveling. An object of the present invention is to provide a driving force control device for a vehicle that can perform the driving.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a main drive source for driving a main drive wheel, a sub drive source capable of transmitting drive torque to a sub drive wheel, and a torque transmission from the sub drive source to the sub drive wheels. A driving force control device for a vehicle, comprising: a clutch interposed in a route, wherein the clutch is connected in a four-wheel drive state, and the clutch is released in a two-wheel drive state.
If it is determined that the vehicle is traveling from the four-wheel drive state to the two-wheel drive state while the vehicle is running, the output torque of the slave drive source becomes a torque equivalent to the torque required for the slave drive source to rotate at the same acceleration as the acceleration of the slave drive wheel. And a clutch release means for disengaging the clutch when the vehicle is in the off state; and a slave drive source control means for controlling the output torque of the slave drive source. It is determined that the output torque of the driving source is changing in the decreasing direction, and the output torque of the sub-driving source during the decrease is the torque required for the sub-driving source to rotate at the same acceleration as the acceleration of the sub-driving wheel. When the distance is considerably approached, the reduction rate of the output torque of the sub-drive source is regulated to a value that can be followed by the sub-drive source and the sub-drive source control means .
[0008]
【The invention's effect】
According to the present invention, when the output torque of the sub-drive source is reduced to a torque equivalent to the torque at which the acceleration of the sub-drive source on the clutch input side becomes equal to the acceleration of the sub-drive wheels on the clutch output side, Is released, the clutch is released in a state where the torque at the clutch is zero or small. As a result, it is possible to avoid occurrence of a shock when the clutch is released.
[0009]
When the rear wheels rotate at a constant speed, the torque corresponding to the above torque is a torque corresponding to the friction in the motor and a torque transmission path from the motor to the clutch.
That is, the torque corresponding to the above-mentioned torque is “the torque corresponding to the friction in the motor and the torque transmission path from the motor to the clutch” and “the torque required to accelerate the clutch input side equally to the driven wheels”. Is the sum of
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating a system configuration of a vehicle according to the present embodiment.
As shown in FIG. 1, in the vehicle according to the present embodiment, left and right front wheels 1L and 1R are main drive wheels driven by an engine 2 (main drive source), which is an internal combustion engine, and left and right rear wheels 3L and 3R. , Are driven wheels that can be driven by the motor 4 (sub-drive source).
[0011]
That is, the output torque Te of the engine 2 is transmitted to the left and right front wheels 1L, 1R through the transmission 30 and the difference gear 31.
The transmission 30 is provided with a shift position detecting means 32 for detecting a current shift range. The shift position detecting means 32 outputs a detected shift position signal to the 4WD controller 8.
[0012]
A main throttle valve 15 and a sub-throttle valve 16 are interposed in an intake pipe 14 (for example, an intake manifold) of the engine 2. The throttle opening of the main throttle valve 15 is adjusted and controlled according to the amount of depression of an accelerator pedal 17 which is an accelerator opening instruction device (acceleration instruction operation unit). The engine controller 18 electrically controls the main throttle valve 15 in response to the depression amount of the accelerator pedal 17 mechanically or in accordance with a depression amount detection value of an accelerator sensor 40 for detecting the depression amount of the accelerator pedal 17. , The throttle opening is adjusted. The depression amount detection value of the accelerator sensor 40 is also output to the 4WD controller 8.
[0013]
The opening of the sub-throttle valve 16 is adjusted and controlled by a rotation angle corresponding to the number of steps, using a step motor 19 as an actuator. The rotation angle of the step motor 19 is adjusted and controlled by a drive signal from a motor controller 20. The sub-throttle valve 16 is provided with a throttle sensor, and the number of steps of the step motor 19 is feedback-controlled based on a throttle opening detection value detected by the throttle sensor. Here, the output torque of the engine 2 is controlled independently of the operation of the accelerator pedal by the driver by adjusting the throttle opening of the sub-throttle valve 16 to the opening of the main throttle valve 15 or less. Can be.
[0014]
The engine rotation speed sensor 21 detects the rotation speed of the engine 2, and outputs the detected signal to the engine controller 18 and the 4WD controller 8.
Reference numeral 34 denotes a brake pedal which constitutes a braking instruction operation unit. The stroke amount of the brake pedal 34 is detected by a brake stroke sensor 35. The brake stroke sensor 35 outputs the detected brake stroke amount to the brake controller 36 and the 4WD controller 8.
[0015]
The brake controller 36 controls the braking force acting on the vehicle through braking devices 37FL, 37FR, 37RL, 37RR such as disc brakes mounted on each of the wheels 1L, 2R, 3L, 3R according to the input brake stroke amount. .
In addition, a part of the rotational torque Te of the engine 2 is transmitted to the generator 7 via the endless belt 6, and the generator 7 rotates the rotational speed Ne of the engine 2 by a pulley ratio. Rotate at Nh.
[0016]
As shown in FIG. 2, the generator 7 includes a voltage regulator 22 (regulator) for adjusting the output voltage V, and the generator control command value c1 (duty ratio) is controlled by the 4WD controller 8. Thus, the power generation load torque Th for the engine 2 and the voltage V for power generation are controlled through the field current Ifh. That is, the voltage regulator 22 receives the generator control command c1 (field current value) from the 4WD controller 8, adjusts the field current Ifh of the generator 7 to a value corresponding to the generator control command c1, and , The output voltage V of the generator 7 can be detected and output to the 4WD controller 8. The rotation speed Nh of the generator 7 can be calculated from the rotation speed Ne of the engine 2 based on the pulley ratio.
[0017]
The power generated by the generator 7 can be supplied to the motor 4 via the electric wire 9. A junction box 10 is provided in the middle of the electric wire 9. The drive shaft of the motor 4 can be connected to the rear wheels 3L, 3R via a speed reducer 11 and a clutch 12. Reference numeral 13 represents a differential.
Further, a current sensor 23 is provided in the junction box 10. The current sensor 23 detects a current value Ia of electric power supplied from the generator 7 to the motor 4, and outputs the detected armature current signal to 4WD. Output to the controller 8. Further, a voltage value (voltage of the motor 4) flowing through the electric wire 9 is detected by the 4WD controller 8. Reference numeral 24 denotes a relay, which controls interruption and connection of a voltage (current) supplied to the motor 4 by a command from the 4WD controller 8.
[0018]
Further, in the motor 4, the field current Ifm is controlled by a command from the 4WD controller 8, and the drive torque Tm (n) is adjusted by adjusting the field current Ifm. Reference numeral 25 denotes a thermistor for measuring the temperature of the motor 4.
A motor speed sensor 26 for detecting the speed Nm of the drive shaft of the motor 4 is provided. The motor speed sensor 26 outputs a detected speed signal of the motor 4 to the 4WD controller 8. The motor rotation speed sensor 26 constitutes an input shaft side rotation speed detecting means.
[0019]
The clutch 12 is a hydraulic clutch or an electromagnetic clutch, and is in a connected state or a disconnected state according to a clutch control command from the 4WD controller 8.
Further, wheel speed sensors 27FL, 27FR, 27RL, 27RR are provided for the respective wheels 1L, 1R, 3L, 3R. Each wheel speed sensor 27FL, 27FR, 27RL, 27RR outputs a pulse signal corresponding to the rotation speed of the corresponding wheel 1L, 1R, 3L, 3R to the 4WD controller 8 as a wheel speed detection value.
[0020]
As shown in FIG. 3, the 4WD controller 8 includes a generator control unit 8A, a relay control unit 8B, a motor control unit 8C, a clutch control unit 8D, a surplus torque calculation unit 8E, a target torque limit unit 8F, and a surplus torque conversion unit 8G. , And a clutch release processing unit 8H.
The generator control unit 8A adjusts the field current Ifh by outputting the generator command value c1 of the generator 7 while monitoring the generated voltage V of the generator 7 through the voltage regulator 22.
[0021]
The relay control unit 8B controls interruption / connection of power supply from the generator 7 to the motor 4.
The motor control unit 8C adjusts the torque of the motor 4 to a required value by adjusting the field current Ifm of the motor 4.
The clutch control unit 8D controls the state of the clutch 12 by outputting a clutch control command to the clutch 12.
[0022]
Further, at every predetermined sampling time, based on the input signals, the processing is performed in the order of the surplus torque calculating section 8E → the target torque limiting section 8F → the surplus torque converting section 8G. Here, the surplus torque calculation unit 8E, the target torque limit unit 8F, and the surplus torque conversion unit 8G constitute a sub-drive source control unit.
Next, the surplus torque calculation unit 8E performs a process as shown in FIG.
[0023]
That is, first, in step S10, based on the wheel speeds of the front wheels 1L, 1R (main drive wheels), the rear wheels 3L, 3R (slave drive wheels) are calculated based on the signals from the wheel speed sensors 27FL, 27FR, 27RL, 27RR. By subtracting the wheel speed, a slip speed ΔVF, which is an acceleration slip amount of the front wheels 1L and 1R, is obtained, and the process proceeds to step S20.
[0024]
Here, the calculation of the slip speed ΔVF is performed, for example, as follows.
The average front wheel speed VWf, which is the average value of the left and right wheel speeds at the front wheels 1L, 1R, and the average rear wheel speed VWr, which is the average value of the left and right wheel speeds at the rear wheels 3L, 3R, are calculated by the following equations.
VWf = (VWfl + VWfr) / 2
VWr = (VWrl + VWrr) / 2
Next, from the deviation between the average front wheel speed VWf and the average rear wheel speed VWr, the slip speed (acceleration slip amount) ΔVF of the front wheels 1L, 1R, which are the main drive wheels, is calculated by the following equation.
[0025]
ΔVF = VWf−VWr
In step S20, it is determined whether the obtained slip speed ΔVF is larger than a predetermined value, for example, zero. If the slip speed ΔVF is determined to be 0 or less, it is estimated that the front wheels 1L and 1R are not accelerating and slipping. Therefore, the process proceeds to step S30, and the process returns after substituting zero for Th.
[0026]
On the other hand, if it is determined in step S20 that the slip speed ΔVF is greater than 0, it is estimated that the front wheels 1L and 1R are accelerating and the process proceeds to step S40.
In step S40, the absorption torque TΔVF required to suppress the acceleration slip of the front wheels 1L, 1R is calculated by the following equation, and the process proceeds to step S50. This absorption torque TΔVF is an amount proportional to the acceleration slip amount.
[0027]
TΔVF = K1 × ΔVF
Here, K1 is a gain obtained by an experiment or the like.
In step S50, the current load torque TG of the generator 7 is calculated based on the following equation, and then the process proceeds to step S60.

here,
V: voltage Ia of the generator 7: armature current Nh of the generator 7: rotation speed K3 of the generator 7: efficiency K2: coefficient.
In step S60, a surplus torque, that is, a target power generation load torque Th to be loaded by the generator 7 is determined based on the following equation, and the process returns.
[0028]
Th = TG + TΔVF
Next, the processing of the target torque limiting unit 8F will be described with reference to FIG.
That is, first, in step S110, it is determined whether the target power generation load torque Th is greater than the maximum load capacity HQ of the generator 7. When it is determined that the target power generation load torque Th is equal to or less than the maximum load capacity HQ of the generator 7, the process returns. On the other hand, when it is determined that the target power generation load torque Th is larger than the maximum load capacity HQ of the generator 7, the process proceeds to step S120.
[0029]
In step S120, the excess torque ΔTb exceeding the maximum load capacity HQ at the target power generation load torque Th is obtained by the following equation, and the process proceeds to step S130.
ΔTb = Th−HQ
In step S130, the current engine torque Te is calculated based on the signals from the engine speed detection sensor 21 and the throttle sensor and the like, and the process proceeds to step S140.
[0030]
In step S140, the engine torque upper limit TeM is calculated by subtracting the excess torque ΔTb from the engine torque Te, and the calculated engine torque upper limit TeM is output to the engine controller 18 as in the following equation. Transition.
TeM = Te−ΔTb
In step S150, the process returns after substituting the maximum load capacity HQ for the target power generation load torque Th.
[0031]
Next, the processing of the surplus torque converter 8G will be described with reference to FIG.
First, in step S200, it is determined whether Th is greater than 0. If it is determined that Th> 0, it means that the front wheels 1L and 1R are performing an acceleration slip, and the process proceeds to step S210. If it is determined that Th ≦ 0, the front wheels 1L, 1R are in a state in which no acceleration slip has occurred, and thus return to the original state.
[0032]
In step S210, the rotation speed Nm of the motor 4 detected by the motor rotation speed sensor 21 is input, a target motor field current Ifm corresponding to the rotation speed Nm of the motor 4 is calculated, and the target motor field current Ifm is calculated. Is output to the motor control unit 8C, and the process proceeds to step S220.
Here, the target motor field current Ifm with respect to the rotation speed Nm of the motor 4 is a constant predetermined current value when the rotation speed Nm is equal to or less than the predetermined rotation speed, and when the motor 4 becomes equal to or higher than the predetermined rotation speed. First, the field current Ifm of the motor 4 is reduced by a known field weakening control method. That is, when the motor 4 rotates at a high speed, the motor torque decreases due to an increase in the motor induced voltage E. Therefore, as described above, when the rotation speed Nm of the motor 4 exceeds a predetermined value, the field current Ifm of the motor 4 is reduced. The current flowing through the motor 4 is increased by decreasing the induced voltage E by reducing the value, thereby obtaining the required motor torque Tm (n). As a result, the required motor torque Tm (n) can be obtained because the increase in the motor induced voltage E is suppressed and the decrease in the motor torque is suppressed even when the motor 4 rotates at a high speed. In addition, by controlling the motor field current Ifm in two stages of less than a predetermined number of revolutions and more than a predetermined number of revolutions, it is possible to reduce the cost of the control electronic circuit as compared with continuous field current control.
[0033]
It should be noted that a motor torque correcting means for continuously correcting the motor torque Tm (n) by adjusting the field current Ifm according to the rotation speed Nm of the motor 4 with respect to the required motor torque Tm (n) may be provided. good. That is, it is preferable to adjust the field current Ifm of the motor 4 according to the motor rotation speed Nm with respect to the two-stage switching. As a result, even if the motor 4 rotates at a high speed, the required motor torque Tm (n) can be obtained because the increase in the induced voltage E of the motor 4 is suppressed and the decrease in the motor torque is suppressed. In addition, since the motor torque characteristics can be made smooth, the vehicle can run more stably as compared with the two-step control, and the motor driving efficiency can always be kept good.
[0034]
In step S220, the induced voltage E of the motor 4 is calculated from the target motor field current Ifm and the rotation speed Nm of the motor 4, and the process proceeds to step S230.
In step S230, the corresponding target motor torque Tm (n) is calculated based on the power generation load torque Th calculated by the surplus torque calculation unit 8E, and the process proceeds to step S240.
[0035]
In step S240, after executing the clutch release processing unit 8H described later, the process proceeds to step S250.
In step S250, the corresponding target armature current Ia is calculated using the current target motor torque Tm (n) and the target motor field current Ifm as variables, and the process proceeds to step S260.
[0036]
In step S260, the duty ratio c1, which is the control command value for the generator 7, is obtained from the target armature current Ia, and the output is returned after output.
Here, the surplus torque converter 8G calculates the target voltage V at the generator 7 according to the target power generation load torque Th in consideration of the control on the motor side. The voltage value V that becomes the target power generation load torque Th may be directly calculated.
[0037]
Next, the processing of the clutch release processing unit 8H will be described with reference to FIG.
First, in step S410, it is determined whether or not the target motor torque is decreasing. If it is determined that the target motor torque is decreasing, the process proceeds to step S420. If it is determined that the target motor torque is not decreasing, the process is stopped. To return.
Whether or not the value is decreasing may be determined by simply comparing with the previous value as described below.
[0038]
Tm (n) −Tm (n−1) <0
Here, the suffix (n-1) is the target motor torque one operation cycle before.
However, in order to suppress the influence of noise and the like, it may be determined whether or not the motor torque is decreasing based on the history value of the target motor torque for three cycles or more as follows (in the following equation, the value for six cycles is determined). Example used). Further, when the target motor torque value continuously decreases for a plurality of calculation cycles, it may be determined that the target motor torque value is decreasing.
[0039]
{Tm (n) + Tm (n-1) + Tm (n-2)}
− {Tm (n−3) + Tm (n−4) + Tm (n−5)} <0
In step S420, it is determined whether or not the current target motor torque Tm (n) is smaller than a motor torque reduction rate switching threshold value T-TM1. Then, the process proceeds to step S430, and the decreasing gradient of the motor torque is set to be constant. On the other hand, if it is determined that it is equal to or greater than the motor torque reduction rate switching threshold T-TM1, the process proceeds to step S460.
[0040]
In step S430, it is determined whether or not the current target motor torque Tm (n) is smaller than a motor torque reduction rate switching threshold T-TM2. If it is determined that the target motor torque Tm (n) is smaller, the process proceeds to step S440; In this case, the process moves to step S450.
In step S440, based on the following equation, the motor torque is set to decrease at the normal torque reduction rate DTm, and the process proceeds to step S460.
[0041]
Tm (n) = Tm (n-1) -DTm
On the other hand, in step S450, based on the following equation, the normal torque reduction rate DTm is multiplied by a gain K (for example, 0.5) smaller than 1 to regulate the reduction rate so that the torque reduction rate becomes slower. Then, control goes to a step S460.
Tm (n) = Tm (n−1) −DTm × K
Although the reduction rate is controlled to be small by multiplying the gain K by less than 1, the subtraction may be performed at a preset predetermined reduction rate. The reduced rate after the regulation is set to be a small reduced rate that can be followed by the torque control of the motor, that is, a range in which the difference between the actual torque value and the target motor torque (torque command value) does not occur. . The phrase “capable of following by motor torque control” is set, for example, to a reduction rate that is slower than the response speed until the actual torque value becomes the torque command value.
[0042]
When steps S420 and S440 are omitted and the process proceeds from step S430 to step S450, instead of step S450, the reduction rate of the controlled motor torque is multiplied by a predetermined maximum limit value, and the predetermined reduction rate is reduced. The motor torque may not be reduced quickly, that is, the motor torque may not be quickly reduced.
In step S460, the current target motor torque Tm (n) is substantially equal to the clutch input side acceleration and the clutch output side acceleration at the moment when the clutch is released, that is, the torque Tf ( Hereafter, it is determined whether or not the torque is substantially equal to the corresponding torque Tf. If it is determined that the torque is substantially equal to the corresponding torque Tf, a clutch release command is output through the clutch controller 8D in step S470. The process ends later. On the other hand, if the torque does not substantially coincide with the corresponding torque Tf, the process ends and the process returns.
[0043]
It is preferable that the equivalent torque Tf be corrected by the response delay of the clutch operation.
Here, the motor torque reduction rate switching threshold T-TM1, the motor torque reduction rate switching threshold T-TM2, and the equivalent torque Tf will be described. These three values have the following relationship.
[0044]
T-TM1>T-TM2> Tf
The above-mentioned equivalent torque Tf is a value calculated by a map or calculation or obtained by an experiment in accordance with the vehicle acceleration or the friction of the torque transmission path on the motor side, or the like. Is the motor torque required for
[0045]
This equivalent torque Tf is estimated to be the sum of "torque for the friction of the motor and the speed reducer" and "torque for accelerating the motor and the speed reducer equal to the acceleration of the rear wheels". In addition. This equivalent torque Tf may be a fixed value determined by an experiment or the like.
The motor torque reduction rate switching threshold value T-TM2 is a torque value that is larger than the equivalent torque Tf and is close to the equivalent torque Tf, and is a value larger than the equivalent torque Tf so that the motor control system can follow up. .
[0046]
The motor torque reduction rate switching threshold T-TM1 is a torque value assumed to be in a state of shifting from the four-wheel drive state to the two-wheel drive state.
Here, the clutch release processing unit 8H and the clutch control unit 8D constitute a clutch release processing unit.
Next, the processing of the engine controller 18 will be described.
[0047]
In the engine controller 18, a process as shown in FIG. 8 is performed based on each input signal at every predetermined sampling time.
That is, first, in step S610, the target output torque TeN required by the driver is calculated based on the detection signal from the accelerator sensor 40, and the process proceeds to step S620.
[0048]
In step S620, it is determined whether there is an input of the limited output torque TeM from the 4WD controller 8. If it is determined that there is an input, the process moves to step S630. On the other hand, if it is determined that there is no input, the process moves to step S650.
In step S630, it is determined whether the limit output torque TeM is larger than the target output torque TeN. When it is determined that the limited output torque TeM is larger, the process proceeds to step S640. On the other hand, if the limit output torque TeM is smaller or equal to the target output torque TeN, the process shifts to step S650.
[0049]
In step S640, the target output torque TeN is increased by substituting the limit output torque TeM for the target output torque TeN, and the process proceeds to step S670.
In step S670, the current output torque Te is calculated based on the throttle opening, the engine speed, and the like, and the flow shifts to step S680.
In step S680, a deviation ΔTe ′ of the target output torque TeN from the current output torque Te is output based on the following equation, and the flow proceeds to step S690.
[0050]
ΔTe ′ = TeN−Te
In step S690, a change .DELTA..theta. In the throttle opening .theta. According to the difference .DELTA.Te is calculated, an opening signal corresponding to the change .DELTA..theta. In the throttle is output to the step motor 19, and the flow returns.
Next, the operation and the like of the apparatus having the above configuration will be described.
[0051]
If the torque transmitted from the engine 2 to the front wheels 1L, 1R becomes larger than the road surface reaction force limit torque due to a small road surface μ or a large depression amount of the accelerator pedal 17 by the driver, that is, the main drive wheels 1L, When the front wheels 1L and 1R, which are 1R, are accelerated and slipped, the clutch 12 is connected, and the generator 7 generates power with the power generation load torque Th corresponding to the acceleration slip amount, thereby shifting to the four-wheel drive state. Then, the driving torque transmitted to the front wheels 1L, 1R is adjusted so as to approach the road surface reaction force limit torque of the front wheels 1L, 1R, thereby shifting to the two-wheel drive state. As a result, the acceleration slip in the front wheels 1L and 1R, which are the main driving wheels, is suppressed.
[0052]
Moreover, the motor 4 is driven by the surplus electric power generated by the generator 7, and the rear wheels 3L and 3R, which are the driven wheels, are also driven, so that the acceleration of the vehicle is improved.
At this time, since the motor 4 is driven with an excess torque exceeding the road surface reaction force limit torque of the main drive wheels 1L, 1R, energy efficiency is improved, which leads to improvement in fuel efficiency.
Here, when the rear wheels 3L and 3R are always driven, the energy conversion is performed several times in the order of mechanical energy → electrical energy → mechanical energy, so that energy loss corresponding to the conversion efficiency occurs. Thus, the acceleration of the vehicle is reduced as compared with the case where the vehicle is driven only by the front wheels 1L and 1R. For this reason, it is desired that the driving of the rear wheels 3L and 3R be suppressed in principle. On the other hand, in the present embodiment, even if the output torque Te of all the engines 2 is transmitted to the front wheels 1L, 1R on a slippery road surface, etc., not all of them are used as the driving force. An unusable driving force is output to the rear wheels 3L and 3R to improve acceleration.
[0053]
In addition, as the clutch 12 is connected, the four-wheel drive state is established, and subsequently, as the acceleration slip is suppressed, the motor torque continuously decreases and the state shifts to the two-wheel drive state.
At this time, if the target motor torque exceeds the motor torque reduction rate switching threshold T-TM1, it is determined that the vehicle is shifting to the two-wheel drive state, and the reduction rate of the motor torque, that is, the reduction rate, is set to a constant DTm and decreases at a predetermined gradient. Further, when the target motor torque substantially matches the equivalent torque Tf, a clutch release command is output to release the clutch 12. At this time, since the torque at the clutch 12 is small, it is possible to prevent the occurrence of a shock when the clutch is released.
[0054]
Further, in the present embodiment, if the target motor torque exceeds the motor torque reduction rate switching threshold T-TM2 before the equivalent torque Tf is reached, the reduction rate of the motor torque, that is, the reduction rate, is controlled according to the control performance of the motor drive control. By restricting the torque to a value as small as possible, the deviation between the torque command value and the actual torque is suppressed to be small. As a result, the motor torque controllability at the time of disengagement of the clutch is improved, and it is possible to more reliably adjust the motor torque to a state where the torque at the clutch 12 is small, so that a shock is more reliably generated at the time of disengagement of the clutch. Can be prevented.
[0055]
FIG. 9 shows an example of the time chart.
As can be seen from FIG. 9, even if the reduction rate of the motor torque is intentionally set to be slow when approaching the equivalent torque Tf, the time is short, and when the torque is between T-TM1 and T-TM2, The torque reduction rate can be set to a desired value.
Here, in the above-described embodiment, the case where the motor 4 is driven by the voltage generated by the generator 7 to configure the four-wheel drive has been described, but the present invention is not limited to this. The present invention may be applied to a system including a battery that can supply power to the motor 4. In this case, a minute power may be supplied from the battery, or the power supply from the generator 7 may be performed simultaneously with the supply from the battery.
[0056]
Alternatively, in the above embodiment, an internal combustion engine is exemplified as the main drive source, but the main drive source may be configured by a motor.
Further, in the above system, the case where the vehicle shifts to the four-wheel drive state according to the acceleration slip of the front wheel has been described. However, a system that shifts to the four-wheel drive state according to the accelerator opening and the like can be applied.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an apparatus according to an embodiment of the present invention.
FIG. 2 is a system configuration diagram according to an embodiment based on the present invention.
FIG. 3 is a block diagram showing a 4WD controller according to an embodiment according to the present invention.
FIG. 4 is a diagram illustrating a process of a surplus torque calculation unit according to the embodiment based on the present invention.
FIG. 5 is a diagram illustrating a process of a target torque control unit according to the embodiment based on the present invention.
FIG. 6 is a diagram showing a process of a surplus torque converter according to the embodiment based on the present invention.
FIG. 7 is a diagram illustrating processing of a clutch release processing unit according to the embodiment based on the present invention.
FIG. 8 is a diagram showing processing of an engine controller according to the embodiment based on the present invention.
FIG. 9 is a diagram showing a time chart of clutch release according to the embodiment based on the present invention.
[Explanation of symbols]
1L, 1R Front wheel 2 Engine 3L, 3R Rear wheel 4 Motor 6 Belt 7 Generator 8 4WD controller 8A Generator control unit 8B Relay control unit 8C Motor control unit 8D Clutch control unit 8E Excess torque calculation unit 8F Target torque limit unit 8G Surplus Torque conversion unit 8H Clutch release processing unit 9 Electric wire 10 Junction box 11 Reducer 12 Clutch 14 Intake line 15 Main throttle valve 16 Sub throttle valve 18 Engine controller 19 Step motor 20 Motor controller 21 Engine speed sensor 22 Voltage regulator 23 Current Sensor 26 Motor speed sensor 27FL, 27FR, 27RL, 27RR Wheel speed sensor 30 Transmission 31 Differential gear 32 Shift position detecting means 34 Brake pedal 35 Brake stroboscope Sensor (braking operation amount detection means)
36 brake controller 37FL, 37FR, 37RL, 37RR brake device 40 accelerator sensor (acceleration instruction detecting means)
Ifh Generator field current V Generator voltage Nh Generator rotation speed Ia Armature current Ifm Motor field current E Motor induced voltage Nm Motor rotation speed (rotation speed)
ΔNm Motor rotational acceleration TG Generator load torque Th Target generator load torque Th2 Second target generator load torque Tm (n) Current target torque of motor Te Output torque of engine T-TM1 Motor torque reduction rate switching threshold T- TM2 Motor torque reduction rate switching threshold value Tf Equivalent torque TDm Reduction rate

Claims (3)

A main drive source for driving the main drive wheels, a sub-drive source capable of transmitting drive torque to the sub-drive wheels, and a clutch interposed in a torque transmission path from the sub-drive source to the sub-drive wheels, In the vehicle driving force control device, the clutch is connected in a four-wheel drive state, and the clutch is released in a two-wheel drive state.
If it is determined that the vehicle is traveling from the four-wheel drive state to the two-wheel drive state while the vehicle is running, the output torque of the slave drive source becomes a torque equivalent to the torque required for the slave drive source to rotate at the same acceleration as the acceleration of the slave drive wheel. The clutch release means to release the clutch when the state, the auxiliary drive source control means for controlling the output torque of the auxiliary drive source,
The sub-drive source control means determines that the output torque of the sub-drive source is changing in the decreasing direction while the vehicle is traveling, and the output torque of the sub-drive source during the reduction is determined by the acceleration of the sub-drive wheels and the acceleration of the sub-drive wheels. When approaching the torque required for the sub-drive to rotate at the same acceleration, the reduction rate of the output torque of the sub-drive is regulated to a value that can be followed by the sub-drive and the sub-drive control means. A driving force control device for a vehicle, comprising: A vehicle including a main drive source for driving a main drive wheel, a sub-drive source capable of transmitting driving torque to a sub-drive wheel, and a clutch interposed in a torque transmission path from the sub-drive source to the sub-drive wheels. In the driving force control device of
If it is determined that the output torque of the secondary drive source is changing in the decreasing direction while the vehicle is traveling, the output torque of the secondary drive source becomes the torque required for the secondary drive source to rotate at the same acceleration as the acceleration of the secondary drive wheels. A driving force control device for a vehicle, comprising: clutch release means for releasing a clutch when a considerable torque is obtained. A secondary drive source control means for controlling an output torque of the secondary drive source, wherein the secondary drive source control means determines that the output torque of the secondary drive source is changing in a decreasing direction while the vehicle is running, and When the output torque of the subordinate drive source approaches the torque required for the subordinate drive source to rotate at the same acceleration as the acceleration of the subordinate drive wheel, the output torque reduction rate of the subordinate drive source is set to 3. The driving force control device for a vehicle according to claim 2, wherein the driving source and the sub-driving source control means regulate the driving force to a value that can be followed.

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