JP3579252B2 - Acceleration slip control device for vehicles with automatic transmission - Google Patents

Description

ここで、Ｅｌｉ、Ｖｌｉ、ΔＹｌｉはそれぞれＥｉ、Ｖｉ、ΔＹｉの前回の処理における値であり、ＫＩ、ＫＰ、ＴＤはそれぞれ重み付けの定数を表わす。
【００３２】
ステップＳ６０においては、修正制動力ΔＹｉを得るために、開閉弁４４ＦＬまたは４６ＦＬ、４４ＦＲまたは４６ＲＲを駆動する時間（パルス幅）ＴＰｉを演算する。
図８は、この発明の実施の形態１におけるステップＳ６０の処理内容を示すフローチャートである。
図８において、ステップＳ６１では開閉弁の応動の限界から、ΔＹｉの絶対値が最低値ΔＹｍｉｎ以上であるかどうかをチェックする。ΔＹｍｉｎ以上であれば、ステップＳ６５で、次回への繰越し分であるΔＹｌｉ＝０にして、修正制動力ΔＹｉをいわゆるブレーキ効力係数ＫＢで除することでホイールシリンダ圧の増分ΔＰｉに変換する。
そして次に、図１０に示すブレーキ系統の液圧−液量特性ｆ（Ｐ）から増圧分ΔＰｉに対応する増液量ΔＱｉを求め、以下の計算のためにＰｉをＰｉ＋ΔＰｉに更新し、フローはステップＳ８０に移行する。
【００３３】
ステップＳ８０では、増液量ΔＱｉの符号により増圧用計算ステップＳ８５と減圧用計算ステップＳ８２に分岐する。それぞれのステップでは増液量ΔＱｉをオリフィスの式（流速∝オリフィス前後の圧力差の平方根）からの流速で除することで開閉弁の駆動時間を求める。
ステップＳ８２では、低圧導管４２の油圧を０とみなすと、オリフィス前後の圧力差はＰｉで、オリフィスの形状・断面積で決まる係数をＣ２として流速はＣ２Ｐ１／２となるので駆動パルス幅ＴＰｉは次式（４）で計算できる。
ＴＰｉ＝ΔＱｉ／｛（Ｃ２・Ｐｉ^１／２）−ｔ２｝ （４）
ここで、ｔ２＞０は開閉弁４６ＦＬまたは４６ＦＲを駆動する際の無駄時間であり，ΔＱｉが負のため負の値として加算してある。
【００３４】
ステップＳ８５においても同様にして、次式（５）により、増圧のために開閉弁４４ＦＬまたは４４ＦＲを非駆動にするパルス幅ＴＰｉを計算する。
ＴＰｉ＝ΔＱｉ／［｛Ｃ１・（Ｐａ−Ｐｉ）^１／２｝＋ｔ１］ （５）
ここでｔ１は、開閉弁駆動の無駄時間である。
一方、ステップＳ６１で修正制動力ΔＹｉが小さいと判定されると、フローはステップＳ６２に移動する。ステップＳ６２では修正制動力ΔＹｉは次回分としてΔＹｌｉに代入された後０にクリヤされ、出力しないのでパルス幅ＴＰｉも０にクリヤされる。
【００３５】
ステップＳ１００では、更新されたＴＰｉに従って、対象開閉弁にパルスを出力する。
ＴＰｉの符号が正の場合は、４４ＦＬまたは４４ＦＲを非駆動のためのパルス（オフ・パルス）をＴＰｉ時間出力し、符号が負の場合は４６ＦＬまたは４６ＦＲを駆動するパルス（オン・パルス）をＴＰｉの絶対値に対応する時間出力する。
ＴＰｉが０の場合は、開閉弁４４ＦＬまたは４４ＦＲは駆動出力で、４６ＦＬまたは４６ＦＲは非駆動状態とする。ただし、今回ＴＰｉが０の場合に限り、前回のパルス出力が終了していない場合は前回のパルス出力終了まで続行する。
【００３６】
ステップＳ１１０では、推定制動力Ｙｉ＝Ｙｉ＋ΔＹｉが計算される。
ステップＳ１２０では、ＡＴ電子制御装置２００に出力する変更指示の判定を行う。
ここで、最低変速段を２速とする変速指示の例について説明する。
この発明の実施の形態１におけるステップＳ１２０の処理内容を示すフローチャートである。
図６において、まず、ステップＳ１２１で本制御中であるかどうかをフラグＦ＿ＣＮＴＲＬでチェックする。
制御中（Ｆ＿ＣＮＴＲＬ＝１）であれば、フローはステップＳ１２２に移り、左右輪の制動力Ｙ１、Ｙ２がともに、判定制動力としての所定値ＹＴＲＧより大きいかどうかのチェックをする。
【００３７】
制動力Ｙ１、Ｙ２がともに所定値ＹＴＲＧより大きければ、変速制御モードを最低変速段を２速とするモードとするように、ＡＴ電子制御装置に指示する変速指示フラグＦ＿２ｎｄをセットする。一方、制動力Ｙ１、Ｙ２が、ともに所定値ＹＴＲＧより小さければ、フローは、そのまま次のステップに移行する。
所定値ＹＴＲＧは、図１１に示すようにスロットル開度θの単調増加関数となっている。
【００３８】
ステップＳ１２１において、制御中でないと判定した場合（Ｆ＿ＣＮＴＲＬ＝０）は、ステップＳ１２５で、変速指示フラグの状態をチェックする。ステップＳ１２５において、Ｆ＿２ｎｄ＝１が成立する場合は、フローがステップＳ１２６に移行し、本来（Ｆ＿２ｎｄ＝０の場合）ＡＴ電子制御装置が変速する変速段Ｇ＿ｐｏｓｉｔｉｏｎが２速以上であるかどうかをチェックする。
ステップＳ１２６において、変速段が２速以上である場合、フローはステップＳ１２８に移行し、変速指示フラグＦ＿２ｎｄをクリヤする。一方、ステップＳ１２６において、変速段が１速である場合は、フローはそのまま次のステップ（ＮＥＸＴ）に移行する。
また、ステップＳ１２５において、変速指示Ｆ＿２ｎｄ＝０（クリヤ）が成立した場合は、そのまま次のステップ（ＮＥＸＴ）に移行する。
【００３９】
以上、この発明の実施の形態１に係る自動変速機付き車両の加速スリップ制御装置によれば、自動変速機から駆動輪までの動力伝達経路とその支持機構で制動力が大きくなると発生する不快な振動を伴うことなく、また、部品点数の増加、製造価格の上昇を伴うエンジンの発生トルク制御装置を追加することなく、好適に加速スリップ制御ができるという効果が得られる。
また、エンジンの発生トルクを調整することなく、自動変速機の変速制御により駆動輪への付与トルクを減少できるので、エンジンの発生トルクを調整するための新たな部品の追加が不必要で比較的安価な加速スリップ制御装置で好適な加速スリップ制御が実現できる。
【００４０】
実施の形態２．
次に添付の図を参照しつつ、本発明の実施の形態２について詳細に説明する。図４は、この発明の実施の形態２に係る自動変速機付き車両の加速スリップ制御装置の制御内容を概略的に示すフローチャートである。
なお、実施の形態２においても、図１及び図２に示すフローによる制御を実施の形態１と同様に行う。
【００４１】
また、図４に示されたフローチャートによる制御は、図には示されていないイグニッションスイッチの閉成により開始され、所定の時間毎に繰り返し実行される。実施の形態１に係る図３に示すフロート同一処理を行う部分には、同一のステップ記号を付し、その説明を省略する。
以下実施の形態１と異なるステップＳ１３０、Ｓ１４０について説明する。
【００４２】
ステップＳ１１０において、推定制動力Ｙｉを演算した後、ステップＳ１３０において、駆動トルクＴｄを次式（６）で計算する。
Ｔｎｉ＝０．５Ｔｄ−Ｙｉ （６）
ここで、Ｇｊは、変速段がｊ速のときのトルコン出力から駆動輪までの減速比である。また、トルク比Ｋｔおよび容量係数Ｋｃは、図１２に示すトルコンの特性で、ここでの速度比ｅは次式（７）で計算する。
ｅ＝ＶＥ／｛０．５（Ｖ１＋Ｖ２）Ｇｊ｝ （７）
駆動輪を駆動する正味駆動トルクＴｎｉを次式（８）で計算する。
Ｔｎｉ＝０．５Ｔｄ−Ｙｉ （８）
【００４３】
図７は、この発明の実施の形態２におけるステップＳ１４０の処理内容を示すフローチャートである。
ステップＳ１４０では、図７の詳細なフローチャートに示すように、実施の形態１と同様に、最低変速段を２速とする変速指示の例について説明する。
まず、ステップＳ１４１で本制御中であるかどうかをフラグＦ＿ＣＮＴＲＬでチェックする。制御中（Ｆ＿ＣＮＴＲＬ＝１）であれば、フローはステップＳ１４２に移り、左右駆動輪の制動力Ｙ１、Ｙ２が、自動変速機の変速段が１速から２速になった場合の駆動輪トルク減少分であるより大きいかどうかのチェックする。
【００４４】
ステップＳ１４２において、左右駆動輪の制動力Ｙ１、Ｙ２が、ともに上記駆動トルクの減少分より大きければ、制動力Ｙ１、Ｙ２を調整することで変速後の正味駆動力が変速前の正味駆動力から減少しないようにできるので、変速制御モードを最低変速段を２速とするモードとするようＡＴ電子制御装置に指示する変速指示フラグＦ＿２ｎｄをセットする。
一方、ステップＳ１４２において、左右駆動輪の制動力Ｙ１、Ｙ２のいずれかの制動力Ｙ１、Ｙ２が、上記駆動トルクの減少分より小さければそのまま次のステップに移行する。
【００４５】
ステップＳ１４１で制御中でない場合（Ｆ＿ＣＮＴＲＬ＝０）は、フローはステップＳ１４５に移り、変速指示フラグの状態をチェックし、Ｆ＿２ｎｄ＝１ならフローはステップＳ１４６に移行し、通常（Ｆ＿２ｎｄ＝０の場合の制御モードで）のＡＴ電子制御装置が変速する変速段Ｇ＿ｐｏｓｉｔｉｏｎが２速以上かどうかチェックして、２速以上なら、フローはステップＳ１４８に移行し、変速指示フラグＦ＿２ｎｄをクリヤし、１速ならそのまま次のステップに移行する。また、ステップＳ１４５で変速指示Ｆ＿２ｎｄ＝０の場合はクリヤのままで次ステップに移行する。
【００４６】
以上、この発明の実施の形態２に係る自動変速機付き車両の加速スリップ制御装置によれば、エンジンの発生トルクを調整することなく、自動変速機の変速制御により駆動輪への付与トルクを減少できるので、エンジンの発生トルクを調整するための新たな部品の追加が不必要で比較的安価な加速スリップ制御装置で好適な加速スリップ制御が実現できる。
また、変速段変化後に車両の減速感（加速の落ち込み）が出ないようにできるため、更に好適な加速スリップ制御ができるという効果がある。
【００４７】
【発明の効果】
この発明の自動変速機付き車両の加速スリップ装置は、エンジンと駆動輪の間に介在し、変速制御手段により自動的に変速する自動変速機付車両の発進時または加速時に発生する前記駆動輪の路面に対するスリップを検出し、検出結果に基づき、駆動輪の制動力を調整する制動力調整手段で駆動輪のスリップを抑制するようにした加速スリップ制御装置において、制動力調整手段の出力信号に基づき、駆動輪に作用する制動力を推定する制動力推定手段と、制動力推定手段の推定結果に基づき、駆動輪へ伝達される駆動トルクを減少させるべく、変速制御手段に変速指示を行う変速指示手段と、を備えることを特徴とするので、自動変速機から駆動輪までの動力伝達経路とその支持機構で制動力が大きくなると発生する不快な振動を伴うことなく、また、部品点数の増加、製造価格の上昇を伴うエンジンの発生トルク制御装置を追加することなく、好適に加速スリップ制御ができるという効果が得られる。
【００４８】
また、この発明の他の形態の自動変速機付き車両の加速スリップ制御装置は、エンジンと駆動輪の間に介在し、変速制御手段により自動的に変速する自動変速機付車両の発進時または加速時に発生する前記駆動輪の路面に対するスリップを検出し、検出結果に基づき、駆動輪の制動力を調整する制動力調整手段で駆動輪のスリップを抑制するようにした自動変速機付き車両の加速スリップ制御装置において、制動力調整手段の出力信号に基づき、駆動輪に作用する制動力を推定する制動力推定手段と、制動力推定手段の推定結果に基づき、駆動輪へ伝達される駆動トルクを減少させるべく、変速制御手段に変速指示を行う変速指示手段と、エンジンから駆動輪に伝達される駆動トルクと、制動力推定手段の推定結果に基づいて算出される推定制動力との差としての正味駆動トルクを算出する正味駆動トルク演算手段と、変速指示に基づく変速後に、制動力調整手段によって調整された結果として推定される正味駆動トルク値が、変速前の正味駆動トルク値より小さくならないときに、変速制御手段に前記駆動輪への駆動トルクを減少させるべく変速指示を行う変速指示手段と、を備えることを特徴とするので、変速段変化後に車両の減速感（加速の落ち込み）が出ないようにできるため、更に好適な加速スリップ制御ができるという効果がある。
【００４９】
また、前記変速指示手段は、推定制動力が、エンジンの負荷状態を調節するアクセルベダル踏み込み量の増加関数としての所定制動力より大きいときに、変速指示を行うことを特徴とするので、変速段変化条件に運転者の加速に対する意志が反映されるために、上記振動抑制と運転者の加速意志の間でより調和のとれた加速スリップ制御ができるという効果がある。
【図面の簡単な説明】
【図１】本発明による加速スリップ制御装置が適用される前輪駆動型の車両の全体構成を示す図である
【図２】この発明の実施の形態１における車両の制動装置の構成を概略的に示す図である。
【図３】この発明の実施の形態１に係る自動変速機付き車両の加速スリップ制御装置の処理内容を示すフローチャートである。
【図４】この発明の実施の形態２に係る自動変速機付き車両の加速スリップ制御装置の制御内容を概略的に示すフローチャートである。
【図５】この発明の実施の形態１におけるステップＳ３０の処理内容を示すフローチャートである。
【図６】この発明の実施の形態１におけるステップＳ１２０の処理内容を示すフローチャートである。
【図７】この発明の実施の形態２におけるステップＳ１４０の処理内容を示すフローチャートである。
【図８】この発明の実施の形態１におけるステップＳ６０の処理内容を示すフローチャートである。
【図９】車体速度に対する前輪速の比と、操舵角の関係を例示する特性図である。
【図１０】ホイールシリンダとその配管を含む系における液圧と液量と関係を例示する特性図である。
【図１１】スロットル開度と判定制動力の関係を示す特性図である。
【図１２】トルクコンバータの速度比とトルク比および容量係数の関係を例示する特性図である。
【符号の説明】
１ エンジン、３ 自動変速機、５ 差動装置、８ ブレーキスイッチ、９ アクセルペダル、１０ 制動装置、１２ ブレーキペダル、１４ マスタシリンダ、１８、２０、２６、２８ ブレーキ油圧制御装置、３４ オイルポンプ、３８ＦＬ、３８ＦＲ、３８ＲＬ、３８ＲＲ ホイールシリンダ、４０ＦＬ、４０ＦＲ、４０ＲＬ、４０ＲＲ 制御弁、４４ＦＬ、４４ＦＲ、４４ＲＬ、４４ＲＲ 開閉弁、４６ＦＬ、４６ＦＲ、４６ＲＬ、４６ＲＲ 開閉弁、５０ トラクション電子制御装置、６０ スロットル開度センサ、６１ エンジン回転速度センサ、６２ 変速機出力軸回転速度センサ、６４ＦＬ〜６４ＲＲ 車輪速センサ、６５ 操舵角センサ、６６ 圧力センサ、２００ ＡＴ電子制御装置。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an acceleration slip control device for a vehicle with an automatic transmission that performs traction control of a vehicle having the automatic transmission.
[0002]
[Prior art]
Preventing excessive slip of the drive wheels on the road surface is effective in effectively obtaining the propulsive force of the vehicle and in terms of safety such as preventing spin. Then, in order to prevent the slip of the drive wheels, the net drive torque of the drive wheels causing the slip may be reduced.
Devices for performing this kind of acceleration slip control include, for example, a device that adjusts only a braking force to adjust a net drive torque and a device that adjusts an engine generated torque, as described in the related art of Japanese Patent Publication No. 2502982. A combination of the adjustment and the adjustment of the braking force is illustrated.
[0003]
[Problems to be solved by the invention]
If an attempt is made to control the driving wheel slip by only the braking force adjusting means for the net driving torque of the driving wheels, unpleasant vibrations may occur when the generated torque of the engine is large. In order to solve this problem, it is common to use the engine output adjustment as described above.
However, in such a solution, it is necessary to add a new device such as a mechanism for adjusting a throttle valve in order to continuously adjust the generated torque of the engine, and the acceleration slip control device becomes expensive.
[0004]
Therefore, the present invention has been made in view of the above-described problems in the conventional acceleration slip control device, and an object of the present invention is to provide a relatively inexpensive acceleration slip control device for a vehicle with an automatic transmission. And
[0005]
[Means for Solving the Problems]
An acceleration slip device for a vehicle with an automatic transmission according to the present invention is provided between the engine and the drive wheels, and the drive slip generated at the time of start or acceleration of the vehicle with an automatic transmission automatically shifted by a shift control means. In an acceleration slip control device which detects slip on a road surface and suppresses slipping of a driving wheel by braking force adjusting means for adjusting a braking force of a driving wheel based on a detection result, based on an output signal of the braking force adjusting means A shift force instructing means for estimating a braking force acting on a drive wheel, and a shift instruction to a shift control means for reducing a drive torque transmitted to the drive wheel based on an estimation result of the brake force estimator. Means.
[0006]
According to another embodiment of the present invention, there is provided an acceleration slip control device for a vehicle with an automatic transmission, which is interposed between an engine and a drive wheel and automatically shifts by a shift control unit when starting or accelerating a vehicle with an automatic transmission. Acceleration slip of a vehicle with an automatic transmission in which the slip of the drive wheel is suppressed by a braking force adjusting means that adjusts the braking force of the drive wheel based on the detection result. In the control device, braking force estimating means for estimating the braking force acting on the driving wheel based on the output signal of the braking force adjusting means, and reducing the driving torque transmitted to the driving wheel based on the estimation result of the braking force estimating means A shift instructing means for giving a shift instruction to the shift control means, a drive torque transmitted from the engine to the drive wheels, and an estimation calculated based on an estimation result of the braking force estimating means. A net drive torque calculating means for calculating a net drive torque as a difference from the power; and a net drive torque value estimated as a result of adjustment by the braking force adjusting means after shifting based on the shift instruction, the net drive torque before shifting is changed. When the torque value does not become smaller, the shift control means is provided with shift instruction means for giving a shift instruction to reduce the drive torque to the drive wheels.
[0007]
The shift instructing means issues a shift instruction when the estimated braking force is larger than a predetermined braking force as an increasing function of an accelerator pedal depression amount for adjusting a load state of the engine.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1 FIG.
Hereinafter, a first embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a diagram showing an entire configuration of a front wheel drive type vehicle to which an acceleration slip control device according to the present invention is applied.
In the vehicle shown in FIG. 1, left and right front wheels 7FL and 7FR are driving wheels, and left and right rear wheels 7RL and 7RR are driven wheels. The driving torque generated by the engine 1 mounted on the front of the vehicle body is transmitted from an automatic transmission 3 (hereinafter referred to as AT) including a torque converter 3a, a planetary gear type transmission gear mechanism 3b and a transmission hydraulic control device 3c to a differential device 5. The power is transmitted to the left and right front wheels 7FL and 7FR via the left and right front wheel drive shafts 6L and 6R.
[0009]
The intake pipe 1b of the engine 1 is provided with a throttle valve 1a connected so as to interlock with an accelerator pedal 9, and such a vehicle is provided with a throttle opening 1 that detects an opening degree θ of the throttle valve 1a. A degree sensor 60 and an engine rotation speed sensor 61 for detecting the output rotation speed of the engine 1 are provided.
The AT3 includes an AT output rotation speed sensor 62 for detecting the rotation speed Vat of the output shaft of the AT3. The shift hydraulic pressure control device 3c has a plurality of shift valves (not shown), and controls each shift speed of the AT3 by changing the drive state of each shift valve.
[0010]
The AT electronic control unit 200 and the traction electronic control unit 50 are connected so that control data can be mutually transmitted and received.
When the drive wheels are not slipping, the AT electronic control device 200 drives the shift valve in order to control the gear position determined by the rotation speed Vat corresponding to the vehicle speed and the opening degree θ.
Around the wheels 7FL, 7FR, 7RL, and 7RR, wheel speed sensors 64FL, 64FR, 64RL, and 64RR for detecting the rotational speed of each wheel, and hydraulic actuators for adjusting the braking force of each wheel are provided. Certain wheel cylinders 38FL, 38FR, 38RL, 38RR are provided.
[0011]
The traction electronic control unit 50 includes a microcomputer 52 and a drive circuit 54. The microcomputer 52 includes, for example, a central processing unit (CPU), a read-only memory (ROM), although not shown in FIG. , A random access memory (RAM), and an input / output port device, which are connected to each other by a bidirectional common bus.
[0012]
The input / output port device of the microcomputer 52 includes an engine rotation speed VE detected by the engine rotation speed sensor 61 and signals VFL-detected by the wheel speed sensors 64FL to 64RR indicating wheel speeds of the left and right front wheels and the left and right rear wheels, respectively. VRR, a signal δ indicating the steering angle detected by the steering angle sensor 65, a signal Pa indicating the pressure in the accumulator 36 detected by the pressure sensor 66, and a brake switch 8 which is turned on / off in conjunction with the brake pedal 12. (SB = 1, SB = 0, non-stepped-on state, SB = 0) is input.
In addition, a signal G_position indicating the gear stage of AT3 and an opening θ that is a signal indicating the throttle opening are input from the AT electronic control device 200, and the shift instruction flag F_2nd information is output to the AT electronic control device 200. It has become.
[0013]
The ROM of the microcomputer 52 stores a control flow and a map described later, and the CPU performs various calculations as described later based on parameters detected by the various sensors described above.
Specifically, the independent target rotation speed Vti of the left and right drive wheels Vi (hereinafter represented by the suffix i, i = 1 and the left drive wheel i = 2 represents the right drive wheel) is independent so that the actual rotation speed Vi matches. The control amount is calculated to control the braking force of each driving wheel, and the braking force of each driving wheel is estimated. If the estimated braking force Yi is larger than a predetermined value, the AT electronic control unit transmits a shift-up shift. Outputs an instruction and performs suitable traction control.
[0014]
FIG. 2 is a diagram schematically showing a configuration of a vehicle braking device according to Embodiment 1 of the present invention.
In FIG. 2, the braking device 10 includes a master cylinder 14 that pumps brake oil from a first port 14a and a second port 14b in response to a driver's depressing operation of a brake pedal 12.
The first port 14a is connected to brake fluid pressure control devices 18 and 20 for the left and right front wheels by a brake fluid pressure control conduit 16 for front wheels, and the second port 14b is connected to a rear wheel having a proportional valve 22 in the middle. Are connected to brake hydraulic pressure control devices 26 and 28 for the left and right rear wheels.
[0015]
Further, the braking device 10 includes an oil pump 34 that pumps up the brake oil stored in the reservoir 30 and supplies it to the high-pressure conduit 32 as high-pressure oil. The high-pressure conduit 32 is connected to each of the brake fluid pressure controllers 18, 20, 26, 28, and an accumulator 36 is connected in the middle thereof.
[0016]
Each of the brake fluid pressure control devices 18, 20, 26, 28 includes a wheel cylinder 38FL, 38FR, 38RL, 38RR, a three-port two-position switching type electromagnetic control valve 40FL, which controls a braking force on a corresponding wheel. 40FR, 40RL, 40RR, normally open electromagnetic on-off valves 44FL, 44FR, 44RL, 44RR provided between the low pressure conduit 42 and the high pressure conduit 32 connected to the reservoir 30, and a normally closed electromagnetic valve The on-off valves 46FL, 46FR, 46RL, 46RR are provided.
[0017]
The high-pressure conduits 32 connecting between the on-off valves 44FL, 44FR, 44RL, 44RR and the on-off valves 46FL, 46FR, 46RL, 46RR are connected to the control valves 40FL, 40FR, 40RL by the connecting conduits 48FL, 48FR, 48RL, 48RR. , 40RR.
Although the wheel cylinders 38FL, 38FR, 38RL, 38RR are also described in FIG. 2 for convenience of explanation, the actual mounting position is the position shown in FIG.
[0018]
The control valves 40FL and 40FR switch between a first position and a second position, and when in the first position, the brake fluid pressure control conduit 16 for the front wheels, the wheel cylinders 38FL and 38FR, respectively. And disconnects the wheel cylinders 38FL and 38FR from the connecting conduits 48FL and 48FR (the positions shown), and when in the second position, disconnects the brake fluid pressure control conduit 16 and the wheel cylinders 38FL and 38FR. At the same time, the wheel cylinders 38FL and 38FR communicate with the connection conduits 48FL and 48FR.
[0019]
Similarly, when in the first position, the control valves 40RL and 40RR communicate the brake fluid pressure control conduit 24 for the rear wheels with the wheel cylinders 38RL and 38RR, respectively, and connect the wheel cylinders 38RL and 38RR with the connection conduit. 48RL and 48RR are shut off, but when in the second position, the brake fluid pressure control conduit 24 and the wheel cylinders 38RL and 38RR are shut off, and the wheel cylinders 38RL and 38RR are connected to the connection conduits 48RL and 48RR. I do.
[0020]
Therefore, when the control valves 40FL, 40FR, 40RL, and 40RR are in the first position, the pressure generated in the brake oil in the master cylinder 14 by depressing the brake pedal 12 causes the wheel cylinders 38FL, 38FR, 38RL, and 38RR to generate pressure. And a braking force corresponding to the depression force of the brake pedal can be obtained.
[0021]
When the control valves 40FL, 40FR, 40RL, and 40RR are in the second position, the on-off valves 44FL, 44FR, 44RL, and 44RR are controlled to be open, and the on-off valves 46FL, 46FR, 46RL, and 46RR are closed. (The state shown), the wheel cylinders 38FL, 38FR, 38RL, 38RR are communicated with the high-pressure conduit 32 via the control valves 40FL, 40FR, 40RL, 40RR and the connection conduits 48FL, 48FR, 48RL, 48RR. Thus, the pressure in the wheel cylinder is increased.
[0022]
Conversely, when the control valves 40FL, 40FR, 40RL, and 40RR are in the second position, the on-off valves 44FL, 44FR, 44RL, and 44RR are closed, and the on-off valves 46FL, 46FR, 46RL, and 46RR are opened. Then, the wheel cylinders 38FL, 38FR, 38RL, 38RR are communicated with the low-pressure conduit 42 via the control valves 40FL, 40FR, 40RL, 40RR and the connecting conduits 48FL, 48FR, 48RL, 48RR, whereby the pressure in the wheel cylinders is reduced. Is decompressed.
[0023]
Further, when the on-off valves 44FL, 44FR, 44RL, 44RR and the on-off valves 46FL, 46FR, 46RL, 46RR are both closed when the control valves 40FL, 40FR, 40RL, 40RR are in the second position, the wheel cylinder is closed. The 38FL, 38FR, 38RL, 38RR is shut off from both the high-pressure conduit 32 and the low-pressure conduit 42, so that the pressure in the wheel cylinders 38FL, 38FR, 38RL, 38RR is maintained.
[0024]
As described above, when the control valves 40FL, 40FR, 40RL, and 40RR are at the first position, the braking device 10 uses the wheel cylinders 38FL, 38FR, 38RL, and 38RR to apply the braking force according to the amount of depression of the brake pedal 12 by the driver. However, when any of the control valves 40FL, 40FR, 40RL, 40RR is at the second position, the on-off valves 44FL, 44FR, 44RL, 44RR and the on-off valves 46FL, 46FR, 46RL, 46RR of the corresponding wheel are opened and closed. By controlling, regardless of the amount of depression of the brake pedal 12 and the braking force of another wheel, the braking force of the wheel can be controlled.
[0025]
The control valves 40FL, 40FR, 40RL, 40RR, the opening / closing valves 44FL, 44FR, 44RL, 44RR and the opening / closing valves 46FL, 46FR, 46RL, 46RR are controlled to be opened and closed by the traction electronic control device 50 as described later in detail. .
[0026]
Next, the acceleration slip control of the vehicle according to the first embodiment will be described with reference to the flowchart shown in FIG.
FIG. 3 is a flowchart showing the processing content of the acceleration slip control device for the vehicle with the automatic transmission according to Embodiment 1 of the present invention.
FIG. 9 is a characteristic diagram illustrating the relationship between the ratio of the front wheel speed to the vehicle speed and the steering angle.
FIG. 10 is a characteristic diagram illustrating the relationship between the hydraulic pressure and the liquid amount in a system including the wheel cylinder and its piping.
FIG. 11 is a characteristic diagram showing the relationship between the throttle opening and the determination braking force.
FIG. 12 is a characteristic diagram illustrating the relationship between the speed ratio, the torque ratio, and the capacity coefficient of the torque converter.
The control according to the flowchart shown in FIG. 3 is started by closing an ignition switch (not shown), and is repeatedly executed at predetermined time intervals.
[0027]
First, in step S10, the gear position signal G_position and the like transmitted from the sensors and the AT electronic control device 200 are read, and in step S20, the left and right independent target wheel speeds Vti are calculated according to equation (1). .
Vti = MAX {VB · g (δ) / (1−λd), Vtmin} (1)
Here, VB is the vehicle speed, the average value of the driven wheel speeds = (VRL + VRR) / 2, λd is the target slip ratio, a numerical example is 0.2, and g (δ) is the vehicle speed of the inner and outer front wheels when steered. This is a characteristic as shown in FIG. 9 which is determined by the function of the steering angle δ in the ratio and substantially the geometrical shape of the vehicle.
MAX {x, y} represents a function in which the larger one of the arguments x and y is selected, and Vti is set to a value equal to or more than a certain value even when VB is close to zero.
[0028]
In step S25, the deviation E between the target wheel speed Vti and the actual wheel speed Vi is calculated by the following equation (2).
Ei = Vi−Vti (2)
[0029]
FIG. 5 is a flowchart showing the processing content of step S30 in the first embodiment of the present invention.
In step S30, the start and the end of the control according to the flow shown in FIG. 5 are determined.
In step S31 of FIG. 5, it is checked whether this control is being performed (flag F_CNTRL = 1). If not, in step S33, the deviation Ei indicating the slip state of the drive wheel and a predetermined value ETRG (positive number) are determined. Compare with
If the deviation Ei of one of the left and right wheels is large, the engine rotation speed VE is larger than the predetermined value VEmin, and if the brake is not depressed (SB = 0), the control is started in step S35. In addition, the flag F_CNTRL is set as a start process, and as a start process, the pump 34 is driven, the open / close valves 44FL, 44FR are driven to switch the hydraulic circuit for the acceleration slip control, and the control valves 40FL, 40FR are also driven, and the next step S40 is performed. Transition.
[0030]
If the deviation E is small in step S33, the flow shifts to the symbol A in FIG.
On the other hand, if the control is being performed (flag F_CNTRL = 1) in step S31, it is determined in step S32 that the control has been completed. If both the braking forces Y1 and Y2 of the left and right wheels are smaller than a predetermined value Ymin, or the brake is depressed. If (SB = 1), this control is ended, the flag F_CNTRL is cleared in step S34, and as an end process, the pump 34 is deactivated and the on-off valves 46FL, 46FR are deactivated to return the hydraulic circuit to normal. The control valves 40FL and 40FR are not driven, and the on-off valves 44FL and 44FR are also not driven.
If one of Y1 and Y2 is larger than Ymin, the control is continued, and the flow moves to the next step S40.
[0031]
In step S40, a corrected braking force ΔYi for making Vi equal to Vti is calculated according to the following equation (3).

Here, Eli, Vli, and ΔYli are the values of Ei, Vi, and ΔYi in the previous process, respectively, and KI, KP, and TD represent weighting constants, respectively.
[0032]
In step S60, a time (pulse width) TPi for driving the on-off valve 44FL or 46FL, 44FR or 46RR is calculated to obtain the corrected braking force ΔYi.
FIG. 8 is a flowchart showing the processing content of step S60 according to Embodiment 1 of the present invention.
In FIG. 8, in step S61, it is checked whether or not the absolute value of ΔYi is equal to or more than the minimum value ΔYmin from the limit of the response of the on-off valve. If it is equal to or more than ΔYmin, in step S65, ΔYli = 0, which is the amount to be carried forward to the next time, is converted to an increment ΔPi of the wheel cylinder pressure by dividing the corrected braking force ΔYi by a so-called brake efficiency coefficient KB.
Then, a fluid increase amount ΔQi corresponding to the pressure increase amount ΔPi is obtained from the fluid pressure-fluid amount characteristic f (P) of the brake system shown in FIG. 10, and Pi is updated to Pi + ΔPi for the following calculation. Shifts to step S80.
[0033]
In step S80, the flow branches to a pressure increase calculation step S85 and a pressure decrease calculation step S82 based on the sign of the liquid increase amount ΔQi. In each step, the drive time of the on-off valve is determined by dividing the liquid increase amount ΔQi by the flow rate from the orifice equation (flow rate∝the square root of the pressure difference before and after the orifice).
In step S82, assuming that the oil pressure in the low-pressure conduit 42 is 0, the pressure difference before and after the orifice is Pi, and the coefficient determined by the shape and cross-sectional area of the orifice is C2, and the flow velocity is C2P1 / 2. It can be calculated by equation (4).
TPi = ΔQi / ｛(C2 · Pi ^1/2 ) -T2} (4)
Here, t2> 0 is a dead time when driving the on-off valve 46FL or 46FR, and is added as a negative value because ΔQi is negative.
[0034]
Similarly, in step S85, the pulse width TPi for deactivating the on-off valve 44FL or 44FR to increase the pressure is calculated by the following equation (5).
TPi = ΔQi / [｛C1 · (Pa−Pi) ^1/2 ｝ + T1] (5)
Here, t1 is a dead time for driving the on-off valve.
On the other hand, if it is determined in step S61 that the corrected braking force ΔYi is small, the flow moves to step S62. In step S62, the corrected braking force ΔYi is substituted for ΔYli as the next time, and is cleared to 0. Since no output is made, the pulse width TPi is also cleared to 0.
[0035]
In step S100, a pulse is output to the target on-off valve according to the updated TPi.
When the sign of TPi is positive, a pulse (off pulse) for not driving 44FL or 44FR is output for TPi time, and when the sign is negative, a pulse (on pulse) for driving 46FL or 46FR is output as TPi. The time corresponding to the absolute value of is output.
When TPi is 0, the on-off valve 44FL or 44FR is driven and the 46FL or 46FR is not driven. However, only when this time TPi is 0, if the previous pulse output has not been completed, the process continues until the previous pulse output is completed.
[0036]
In step S110, the estimated braking force Yi = Yi + ΔYi is calculated.
In step S120, a change instruction to be output to AT electronic control device 200 is determined.
Here, an example of a shift instruction to set the lowest shift speed to the second speed will be described.
6 is a flowchart showing the processing content of step S120 in Embodiment 1 of the present invention.
In FIG. 6, first, in step S121, it is checked whether or not the main control is being performed by using a flag F_CNTRL.
If the control is being performed (F_CNTRL = 1), the flow moves to step S122, and it is checked whether the braking forces Y1 and Y2 of the left and right wheels are both greater than a predetermined value YTRG as a determination braking force.
[0037]
If both the braking forces Y1 and Y2 are greater than the predetermined value YTRG, a shift instruction flag F_2nd for instructing the AT electronic control unit to set the shift control mode to the mode in which the lowest shift stage is the second speed is set. On the other hand, if both braking forces Y1 and Y2 are smaller than predetermined value YTRG, the flow proceeds to the next step as it is.
The predetermined value YTRG is a monotonically increasing function of the throttle opening θ as shown in FIG.
[0038]
If it is determined in step S121 that control is not being performed (F_CNTRL = 0), the state of the shift instruction flag is checked in step S125. If F_2nd = 1 holds in step S125, the flow moves to step S126, and it is checked whether or not the gear stage G_position to which the AT electronic control device shifts originally (if F_2nd = 0) is the second speed or higher. .
If it is determined in step S126 that the shift speed is the second speed or higher, the flow shifts to step S128 to clear the shift instruction flag F_2nd. On the other hand, in step S126, when the shift speed is the first speed, the flow directly proceeds to the next step (NEXT).
If the shift instruction F_2nd = 0 (clear) is satisfied in step S125, the process directly proceeds to the next step (NEXT).
[0039]
As described above, according to the acceleration slip control device for the vehicle with the automatic transmission according to the first embodiment of the present invention, an unpleasant sensation that occurs when the braking force is increased in the power transmission path from the automatic transmission to the drive wheels and the supporting mechanism thereof. The effect that the acceleration slip control can be suitably performed can be obtained without vibration and without adding an engine generated torque control device accompanied by an increase in the number of parts and an increase in manufacturing cost.
Further, since the torque applied to the drive wheels can be reduced by controlling the shift of the automatic transmission without adjusting the torque generated by the engine, it is not necessary to add new parts for adjusting the torque generated by the engine. Suitable acceleration slip control can be realized by an inexpensive acceleration slip control device.
[0040]
Embodiment 2 FIG.
Next, a second embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 4 is a flowchart schematically showing control contents of an acceleration slip control device for a vehicle with an automatic transmission according to Embodiment 2 of the present invention.
In the second embodiment, the control according to the flow shown in FIGS. 1 and 2 is performed in the same manner as in the first embodiment.
[0041]
The control according to the flowchart shown in FIG. 4 is started by closing an ignition switch (not shown), and is repeatedly executed at predetermined time intervals. The same step symbols are given to portions performing the same float processing shown in FIG. 3 according to the first embodiment, and description thereof will be omitted.
Hereinafter, steps S130 and S140 different from the first embodiment will be described.
[0042]
After calculating the estimated braking force Yi in step S110, the driving torque Td is calculated by the following equation (6) in step S130.
Tni = 0.5Td-Yi (6)
Here, Gj is a reduction ratio from the torque converter output to the drive wheels when the gear position is j. Further, the torque ratio Kt and the capacity coefficient Kc are characteristics of the torque converter shown in FIG. 12, and the speed ratio e here is calculated by the following equation (7).
e = VE / {0.5 (V1 + V2) Gj} (7)
The net drive torque Tni for driving the drive wheels is calculated by the following equation (8).
Tni = 0.5Td-Yi (8)
[0043]
FIG. 7 is a flowchart showing the processing content of step S140 in the second embodiment of the present invention.
In step S140, as shown in the detailed flowchart of FIG. 7, an example of a shift instruction to set the minimum shift speed to the second speed as in the first embodiment will be described.
First, in step S141, it is checked whether or not the main control is being performed by using the flag F_CNTRL. If the control is being performed (F_CNTRL = 1), the flow moves to step S142, and the braking forces Y1 and Y2 of the left and right driving wheels decrease the driving wheel torque when the gear position of the automatic transmission changes from the first speed to the second speed. Check if it is greater than minutes.
[0044]
In step S142, if the braking forces Y1 and Y2 of the left and right driving wheels are both greater than the decrease in the driving torque, the braking forces Y1 and Y2 are adjusted so that the net driving force after shifting is reduced from the net driving force before shifting. Since it can be prevented from decreasing, a shift instruction flag F_2nd is set to instruct the AT electronic control unit to set the shift control mode to the mode in which the lowest shift stage is the second speed.
On the other hand, in step S142, if any one of the braking forces Y1 and Y2 of the left and right driving wheels is smaller than the decrease in the driving torque, the process directly proceeds to the next step.
[0045]
If control is not being performed in step S141 (F_CNTRL = 0), the flow proceeds to step S145, and the state of the shift instruction flag is checked. The AT electronic control unit (in the control mode) checks whether the gear stage G_position at which the gear is shifted is the second speed or higher. If the speed is the second speed or higher, the flow shifts to step S148 to clear the shift instruction flag F_2nd, and if it is the first speed, it remains unchanged. Move to the next step. If the shift instruction F_2nd = 0 in step S145, the process proceeds to the next step without any change.
[0046]
As described above, according to the acceleration slip control device for the vehicle with the automatic transmission according to the second embodiment of the present invention, the torque applied to the drive wheels is reduced by the shift control of the automatic transmission without adjusting the torque generated by the engine. Therefore, it is not necessary to add a new component for adjusting the torque generated by the engine, and a suitable acceleration slip control can be realized by a relatively inexpensive acceleration slip control device.
In addition, since it is possible to prevent a feeling of deceleration (decrease in acceleration) of the vehicle after changing the gear position, there is an effect that more suitable acceleration slip control can be performed.
[0047]
【The invention's effect】
An acceleration slip device for a vehicle with an automatic transmission according to the present invention is provided between the engine and the drive wheels, and the drive slip generated at the time of start or acceleration of the vehicle with an automatic transmission automatically shifted by a shift control means. In an acceleration slip control device which detects slip on a road surface and suppresses slipping of a driving wheel by braking force adjusting means for adjusting a braking force of a driving wheel based on a detection result, based on an output signal of the braking force adjusting means A shift force instructing means for estimating a braking force acting on a drive wheel, and a shift instruction to a shift control means for reducing a drive torque transmitted to the drive wheel based on an estimation result of the brake force estimator. Means, and the power transmission path from the automatic transmission to the drive wheels and the supporting mechanism thereof are accompanied by unpleasant vibrations generated when the braking force increases. Ku, also, increase in the number of components, without adding a torque control device for an engine with an increase in manufacturing cost, there is an advantage that it is suitably acceleration slip control.
[0048]
According to another embodiment of the present invention, there is provided an acceleration slip control device for a vehicle with an automatic transmission, which is interposed between an engine and a drive wheel and automatically shifts by a shift control unit when starting or accelerating a vehicle with an automatic transmission. Acceleration slip of a vehicle with an automatic transmission in which the slip of the drive wheel is suppressed by a braking force adjusting means that adjusts the braking force of the drive wheel based on the detection result. In the control device, braking force estimating means for estimating the braking force acting on the driving wheel based on the output signal of the braking force adjusting means, and reducing the driving torque transmitted to the driving wheel based on the estimation result of the braking force estimating means A shift instructing means for giving a shift instruction to the shift control means, a drive torque transmitted from the engine to the drive wheels, and an estimation calculated based on an estimation result of the braking force estimating means. A net drive torque calculating means for calculating a net drive torque as a difference from the power; and a net drive torque value estimated as a result of adjustment by the braking force adjusting means after shifting based on the shift instruction, the net drive torque before shifting is changed. A shift instructing means for instructing the shift control means to reduce the driving torque to the drive wheels when the torque value does not become smaller than the torque value. Since acceleration drop) can be prevented, there is an effect that more suitable acceleration slip control can be performed.
[0049]
Further, the shift instructing means issues a shift instruction when the estimated braking force is larger than a predetermined braking force as an increasing function of an accelerator pedal depressing amount for adjusting the load state of the engine. Since the driver's intention to accelerate is reflected in the change condition, there is an effect that the acceleration slip control can be more harmonized between the vibration suppression and the driver's intention to accelerate.
[Brief description of the drawings]
FIG. 1 is a diagram showing an entire configuration of a front wheel drive type vehicle to which an acceleration slip control device according to the present invention is applied.
FIG. 2 is a diagram schematically showing a configuration of a vehicle braking device according to Embodiment 1 of the present invention.
FIG. 3 is a flowchart showing processing contents of an acceleration slip control device for a vehicle with an automatic transmission according to Embodiment 1 of the present invention.
FIG. 4 is a flowchart schematically showing control contents of an acceleration slip control device for a vehicle with an automatic transmission according to Embodiment 2 of the present invention.
FIG. 5 is a flowchart showing the processing content of step S30 in Embodiment 1 of the present invention.
FIG. 6 is a flowchart showing the processing content of step S120 according to the first embodiment of the present invention.
FIG. 7 is a flowchart showing processing in step S140 according to the second embodiment of the present invention.
FIG. 8 is a flowchart showing the processing content of step S60 according to the first embodiment of the present invention.
FIG. 9 is a characteristic diagram illustrating a relationship between a ratio of a front wheel speed to a vehicle body speed and a steering angle.
FIG. 10 is a characteristic diagram illustrating a relationship between a fluid pressure and a fluid amount in a system including a wheel cylinder and its piping.
FIG. 11 is a characteristic diagram showing a relationship between a throttle opening and a judgment braking force.
FIG. 12 is a characteristic diagram illustrating a relationship between a speed ratio, a torque ratio, and a capacity coefficient of the torque converter.
[Explanation of symbols]
Reference Signs List 1 engine, 3 automatic transmission, 5 differential, 8 brake switch, 9 accelerator pedal, 10 brake, 12 brake pedal, 14 master cylinder, 18, 20, 26, 28 brake hydraulic control unit, 34 oil pump, 38FL , 38FR, 38RL, 38RR Wheel cylinder, 40FL, 40FR, 40RL, 40RR Control valve, 44FL, 44FR, 44RL, 44RR Open / close valve, 46FL, 46FR, 46RL, 46RR Open / close valve, 50 Traction electronic control unit, 60 Throttle opening sensor , 61 engine rotation speed sensor, 62 transmission output shaft rotation speed sensor, 64FL-64RR wheel speed sensor, 65 steering angle sensor, 66 pressure sensor, 200 AT electronic control unit.

Claims (3)

Interposed between the engine and the drive wheels, a slip with respect to the road surface of the drive wheels, which is generated when the vehicle with the automatic transmission starts or accelerates, which is automatically shifted by the shift control means, is detected, and based on the detection result, In an acceleration slip control device configured to suppress the slip of the driving wheel by a braking force adjusting unit that adjusts a braking force of a driving wheel,
Braking force estimating means for estimating a braking force acting on the drive wheel based on an output signal of the braking force adjusting means;
A shift instruction unit for issuing a shift instruction to the shift control unit in order to reduce the drive torque transmitted to the drive wheels based on the estimation result of the braking force estimation unit. Acceleration slip control device. Interposed between the engine and the drive wheels, a slip with respect to the road surface of the drive wheels, which is generated when the vehicle with the automatic transmission starts or accelerates, which is automatically shifted by the shift control means, is detected, and based on the detection result, In an acceleration slip control device configured to suppress the slip of the driving wheel by a braking force adjusting unit that adjusts a braking force of a driving wheel,
Braking force estimating means for estimating a braking force acting on the drive wheel based on an output signal of the braking force adjusting means;
A shift instructing unit configured to instruct the shift control unit to perform a shift instruction to reduce a drive torque transmitted to the drive wheel based on an estimation result of the braking force estimation unit;
A net drive torque calculation means for calculating a net drive torque as a difference between the drive torque transmitted from the engine to the drive wheels and an estimated braking force calculated based on the estimation result of the braking force estimation means;
After the shift based on the shift instruction, when the net drive torque value estimated as a result of the adjustment by the braking force adjustment unit does not become smaller than the net drive torque value before the shift, the shift control unit may Shift instructing means for issuing the shift instruction so as to reduce the driving torque to the wheels. 2. The shift instruction unit according to claim 1, wherein the shift instruction unit issues a shift instruction when the estimated braking force is larger than a predetermined braking force as an increasing function of an accelerator pedal depression amount for adjusting a load state of the engine. Slip control system for vehicles with automatic transmission.

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