JP3835001B2 - Vehicle driving force control device - Google Patents

Description

【００４９】
ステップ４４では、図２の演算部２１におけると同様にして変速機目標入力回転数Ｎ_pri ^* をマップ検索し、
ステップ４５では、図２の演算部２５におけると同様にして無段変速機の実変速比ｉ_T ＝Ｎ_sec ／Ｎ_pri を算出し、
ステップ４６では、図２の演算部２６におけると同様にして目標エンジン出力Ｔ_e ^* ＝Ｔ_SD／ｉ_T 算出する。
【００５０】
ステップ４７では、図２の演算部２３におけると同様にして目標変速比ｉ^* ＝Ｎ_pri ^* ／Ｎ_sec を求め、これを図１の油圧アクチュエータ１２に出力すると共に、図２の演算部２７におけると同様にして目標エンジン出力Ｔ_e ^* を発生させるための目標スロットル開度ＴＶＯ^* を求め、これを図１のステップモータ４に出力する。
【００５１】
図４は本発明の他の実施形態を示し、本実施の形態においては、目標エンジン出力Ｔ_e ^* を上記と異なる別の方式により算出する。
つまり、変速機目標変速比演算部３１において、演算部２２からの変速機目標入力回転数Ｎ_pri ^* を、センサ１８で検出した変速機出力回転数Ｎ_sec で除算することにより変速機目標変速比ｉ_T ^* を算出し、
目標エンジン出力演算部２６においては、過渡目標駆動力Ｔ_SDを当該変速機目標変速比ｉ_T ^* で除算することにより目標エンジン出力Ｔ_e ^* を求めるようにし、
それ以外は、図２におけると同様に構成したものである。
【００５２】
本実施の形態においても、変速機目標入力回転数Ｎ_pri ^* を定常目標駆動力Ｔ_S から求め、目標エンジン出力Ｔ_e ^* を過渡目標駆動力Ｔ_SDから求めるために、前記実施の形態におけると同様の作用効果が奏し得られる。
【００５３】
図４の駆動力制御をフローチャートにより示すと図５のごときものとなり、これは図３のステップ４５，４６をステップ５５，５６に置換させたものに相当する。
ステップ５５は図４の演算部３１に相当し、このステップ５５では変速機目標入力回転数Ｎ_pri ^* を変速機出力回転数Ｎ_sec で除算することにより変速機目標変速比ｉ_T ^* を算出し、
ステップ５６は図４の演算部２６に相当し、このステップ５６では過渡目標駆動力Ｔ_SDを変速機目標変速比ｉ_T ^* で除算することにより目標エンジン出力Ｔ_e ^* を求める。
【００５４】
図６は本発明の更に他の実施形態を示し、本実施の形態においては、目標エンジン出力Ｔ_e ^* を以下のようにして求める。
つまり、要求馬力演算部３２で過渡目標駆動力Ｔ_SDに車速ＶＳＰおよび定数Ｋ_D を掛けて、現在の車速ＶＳＰのもとでの過渡目標駆動力Ｔ_SDに対応した要求馬力ＨＰ_S ＝Ｋ_D ・Ｔ_SD・ＶＳＰを求める。
【００５５】
目標エンジン出力演算部３３では、実験などにより予め求めた図９に例示するエンジンの特性線図を基に、現在の車速ＶＳＰのもと上記算出した要求馬力ＨＰ_S （過渡目標駆動力Ｔ_SD）を最低燃費で発生させるためのエンジン出力Ｔ_e の目標値Ｔ_e ^* を求める。
ちなみに図９上において、上記の要求馬力ＨＰ_S に対応した１本の等馬力線βと最低燃費線δとの交点が例えば図９のＺ点であるとすると、当該要求馬力ＨＰ_S を最低燃費で発生させるための目標エンジン出力Ｔ_e ^* は、図９に示すようにＺ点から縦軸に下ろした目盛り値として求めることができる。
なお、変速機目標入力回転数Ｎ_pri ^* の算出方式は図２および図４におけると同様である。
【００５６】
本実施の形態においても、変速機目標入力回転数Ｎ_pri ^* を定常目標駆動力Ｔ_S から求め、目標エンジン出力Ｔ_e ^* を過渡目標駆動力Ｔ_SDから求めるために、前記各実施の形態におけると同様の作用効果が奏し得られる。
【００５７】
図６の実施形態をフローチャートにより示すと、図７に示す如くになり、これは図３のステップ４５，４６をステップ６５，６６に置換させたものに相当する。
ステップ６５は図６の演算部３２に相当し、このステップ６５では過渡目標駆動力Ｔ_SDに車速ＶＳＰおよび定数Ｋ_D を掛けて、現在の車速ＶＳＰのもとでの過渡目標駆動力Ｔ_SDに対応した要求馬力ＨＰ_S ＝Ｋ_D ・Ｔ_SD・ＶＳＰを求める。
ステップ６６は図６の演算部３３に相当し、このステップ６６では図９に例示するエンジンの特性線図を基に、現在の車速ＶＳＰのもと要求馬力ＨＰ_S （過渡目標駆動力Ｔ_SD）を最低燃費で発生させるための目標エンジン出力Ｔ_e ^* を求める。
【００５８】
図８は、目標エンジン出力Ｔ_e ^* を別の方式により算出するようにした本発明の更に他の実施の形態を示す、図３対応のフローチャートである。
本実施の形態においては、ステップ４１においてエンジン回転数Ｎ_e を付加的に読み込み、ステップ４２〜４４において図３におけると同様に定常目標駆動力Ｔ_S 、過渡目標駆動力Ｔ_SDおよび変速機目標入力回転数Ｎ_pri ^* を求めた後のステップ７１，７２において、プライマリ回転数（トルクコンバータ出力回転数）Ｎ_pri をエンジン回転数（トルクコンバータ入力回転数）Ｎ_e で除算することによりトルクコンバータ速度比ｅ＝Ｎ_pri ／Ｎ_e を算出し、更に、トルクコンバータの特性線図を基に速度比ｅからトルクコンバータのトルク比ｔを検索して求める。
【００５９】
次いでステップ４５において、図３におけると同様に実変速比ｉ_T ＝Ｎ_pri ／Ｎ_sec を算出した後、ステップ４６において過渡目標駆動力Ｔ_SDを無段変速機の実変速比ｉ_T およびトルク比ｔで順次除算することにより目標エンジン出力Ｎ_e ^* を求める。
そしてステップ４７において、図３におけると同様に目標変速比ｉ^* ＝Ｎ_pri ^* ／Ｎ_sec を求め、これを図１の油圧アクチュエータ１２に出力すると共に、目標エンジン出力Ｔ_e ^* を発生させるための目標スロットル開度ＴＶＯ^* を求め、これを図１のステップモータ４に出力する。
【００６０】
本実施の形態においても、変速機目標入力回転数Ｎ_pri ^* を定常目標駆動力Ｔ_S から求め、目標エンジン出力Ｔ_e ^* を過渡目標駆動力Ｔ_SDから求めるために、前記各実施の形態におけると同様の作用効果が奏し得られる。
【００６１】
なお各実施の形態によれば、定常目標駆動力Ｔ_S から変速機目標入力回転数Ｎ_pri ^* を求めるに際し、図９のエンジン特性線図上の最低燃費線δに基づき求めておいた図１１に例示するごとき車速ＶＳＰと、駆動力Ｔ_S と、エンジン回転数Ｎ_e との関係を表すデータを基に、定常目標駆動力Ｔ_S および車速ＶＳＰから求めた、定常目標駆動力Ｔ_S を最低燃費で発生させるための目標エンジン回転数Ｎ_e ^* に対応した変速機入力回転数を変速機目標入力回転数Ｎ_pri ^* とするために、
当該変速機目標入力回転数を最低燃費が達成されるような態様で決定することができ、燃費の改善効果を最大限に高めることができる。
【００６２】
なお、過渡目標駆動力Ｔ_SDから目標エンジン出力Ｔ_e ^* を求めるに際し、図２および図３のごとく、過渡目標駆動力Ｔ_SDを無段変速機の実変速比ｉ_T で除算することによって目標エンジン出力Ｔ_e ^* を求める場合、目標エンジン出力Ｔ_e ^* が現在の変速状態に即したものとなり、現実的なエンジン出力制御が補償される。
【００６３】
また、過渡目標駆動力Ｔ_SDから目標エンジン出力Ｔ_e ^* を求めるに際し、図４および図５のごとく、過渡目標駆動力Ｔ_SDを変速機目標入力回転数Ｎ_pri ^* に対する変速機出力回転数Ｎ_sec の比である無段変速機の目標変速比ｉ_T ^* で除算することによって目標エンジン出力Ｔ_e ^* を求める場合、目標エンジン出力Ｔ_e ^* が、変速機の目標入力回転数Ｎ_pri ^* に対応した変速比ｉ_T ^* への変速を先取りしたものとなり、変速制御に先行したエンジン出力制御が補償される。
【００６４】
更に、過渡目標駆動力Ｔ_SDから目標エンジン出力Ｔ_e ^* を求めるに際し、図６および図７のごとく、過渡目標駆動力Ｔ_SDに車速ＶＳＰを乗じて求めた要求馬力ＨＰ_S を最低燃費で発生させるためのエンジン出力を図９に例示するエンジン特性線図から求め、当該最低燃費エンジン出力を目標エンジン出力Ｔ_e ^* として定める場合、目標エンジン出力Ｔ_e ^* を最低燃費が達成されるような態様で決定し得ることとなり、燃費の改善効果を最大限に高めることができる。
【００６５】
更に、過渡目標駆動力Ｔ_SDから目標エンジン出力Ｔ_e ^* を求めるに際し、図８のごとく、過渡目標駆動力Ｔ_SDを無段変速機の変速比ｉ_T （目標変速比ｉ_T ^* でも良い) 、およびトルクコンバータのトルク比t とで順次除算して目標エンジン出力Ｔ_e ^* を求める場合、
目標エンジン出力Ｔ_e ^* を一層簡単に算出することができて大いに有利である。
【図面の簡単な説明】
【図１】本発明の一実施の形態になる駆動力制御装置を具えた無段変速機搭載車のパワートレーンを、その制御システムと共に示す概略説明図である。
【図２】同実施の形態においてコントローラが実行する変速制御およびスロットル開度制御の機能別ブロック線図である。
【図３】図２の変速制御およびスロットル開度制御をプログラムとして示したフローチャートである。
【図４】本発明の他の実施の形態を示す変速制御およびスロットル開度制御の機能別ブロック線図である。
【図５】図４の変速制御およびスロットル開度制御をプログラムとして示したフローチャートである。
【図６】本発明の更に他の実施の形態を示す変速制御およびスロットル開度制御の機能別ブロック線図である。
【図７】図６の変速制御およびスロットル開度制御をプログラムとして示したフローチャートである。
【図８】本発明の更に別の実施の形態を示す変速制御およびスロットル開度制御の機能別ブロック線図である。
【図９】エンジン回転数軸およびエンジン出力トルク軸により規定した２次元座標上に、等燃費線、等馬力線、最低燃費線を示すエンジンの特性線図である。
【図１０】同最低燃費線を変速比ごとに車速と車軸駆動力との関係線図として書き直した場合の線図である。
【図１１】図１０の線図上で、変速比ごとに入力回転が等しくなる点を結んだ線図として表した、車速と、駆動力と、エンジン回転数との関係線図である。
【図１２】本発明による動作タイムチャートを、従来装置による動作タイムチャートと比較して示す線図である。
【図１３】本発明による動作タイムチャートを、別の従来装置による動作タイムチャートと比較して示す線図である。
【符号の説明】
１ エンジン
２ 無段変速機
３ アクセルペダル
４ ステップモータ
５ 電子制御スロットルバルブ
６ トルクコンバータ（伝動手段）
７ プライマリプーリ
８ セカンダリプーリ
９ Ｖベルト
10 ファイナルドライブギヤ組
11 ディファレンシャルギヤ装置
12 油圧アクチュエータ
13 コントローラ
14 アクセル開度センサ
16 スロットル開度センサ
17 プライマリプーリ回転センサ
18 セカンダリプーリ回転センサ
19 車速センサ
20 エンジン回転センサ
21 定常目標駆動力演算部
22 変速機目標入力回転数演算部
23 目標変速比演算部
24 過渡目標駆動力演算部
25 実変速比演算部
26 目標エンジン出力演算部
27 目標スロットル開度演算部
31 目標変速比演算部
32 要求馬力演算部
33 目標エンジン出力演算部[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a vehicle driving force control device that generates a steady target driving force of a vehicle equipped with a continuously variable transmission with predetermined transient characteristics by integrated control of engine output control and continuously variable transmission control. Is.
[0002]
[Prior art]
A continuously variable transmission represented by a V-belt type continuously variable transmission or a toroidal type continuously variable transmission generally obtains a target gear ratio from an engine demand load and a vehicle speed, and the actual gear ratio becomes this target gear ratio. Shift control is performed.
Accordingly, during acceleration in which the driver depresses the accelerator pedal and the engine required load is increased, the target gear ratio is changed to become larger (the gear ratio on the low speed side), and the continuously variable transmission is changed to the increased target. Downshift to gear ratio,
Conversely, during low-load operation where the driver returns the accelerator pedal to reduce the engine load requirement, the target gear ratio is changed to become smaller (the gear ratio on the high speed side), and the continuously variable transmission becomes smaller. Upshift to the set target gear ratio is performed.
[0003]
On the other hand, as a technique for obtaining a required driving force of a vehicle, there is a conventional technique described in, for example, Japanese Patent Laid-Open No. 7-172217.
This technology obtains the basic required driving force of the vehicle from the vehicle speed and the accelerator pedal depression amount, and adds the running resistance that can be estimated from the vehicle speed to the original required driving force required to drive the wheels. It is what.
[0004]
By the way, with the above-described shift control of the general continuously variable transmission, it is impossible to accurately realize the required driving force obtained by the technique according to the above-mentioned literature. However, it is impossible to achieve the required driving force obtained in such a manner that the fuel consumption of the engine is minimized, for example.
[0005]
For example, in order to achieve the required driving force in such a manner that the fuel consumption of the engine is minimized, the required driving force is controlled by the engine output control and the continuously variable transmission shift control (engine speed control). Driving force control realized by an appropriate combination with the above can be considered.
Therefore, the above required driving force is a steady target value, and in order to achieve this steady target driving force with a predetermined change over time (transient characteristics) to obtain a suitable acceleration / deceleration feeling, the transient driving force It is preferable to set a target value and achieve the transient driving force target value from time to time.
[0006]
By the way, when realizing such transient target driving force in a desired manner by combining engine output control and continuously variable transmission shift control (engine speed control), target engine output and target gear ratio (target input rotation) It is common sense to obtain both of these from the transient target driving force.
[0007]
[Problems to be solved by the invention]
However, obtaining both the target engine output and the target gear ratio (target input rotation speed) from the transient target driving force causes the following problems.
That is, due to obtaining the target gear ratio (target input rotation speed) from the transient target driving force, the instantaneous t as shown in FIG.₁To t₂During this period, the accelerator pedal depressing amount (accelerator opening) APS is increased rapidly, so that the steady target driving force T_SAnd transient target driving force T_SDIn the case where each of the continuously variable transmissions is changed as shown in the figure, the continuously variable transmission has a transmission target input rotational speed N indicated by a broken line in FIG._pri ^*And gear ratio i_TAs is clear from the change with time, it is inevitable that the target gear ratio is reached with a delay by the transient characteristic.
[0008]
Because of this, the target engine output T_e ^*Is the steady target driving force T_SNot transient target driving force T_SDAs shown in FIG. 12, it exhibits a smooth change over time, and can suppress jerky vibrations when the accelerator pedal is suddenly depressed,
Actual driving force T in FIG._OAs apparent from the time-dependent change indicated by the broken line, there is a problem in that the driving performance is insufficient due to the above-described downshift speed change response delay, resulting in a decrease in running performance.
[0009]
Also, the transmission target input speed N_pri ^*For example, in the case where the fuel consumption is determined for a certain purpose, for example, to realize the minimum fuel consumption, the shift response delay as described above increases the driving time out of the purpose, and as a result, the target minimum fuel consumption is realized. The problem of not being able to do so also arises.
[0010]
However, when both the target engine output and the target gear ratio (target input rotation speed) are obtained from the steady target driving force, the target engine output T in the time chart of FIG. 13 when the same accelerator pedal operation as that of FIG. 12 is performed._e ^*And actual driving force T_OAs is clear from the time-dependent change indicated by the broken line, another problem arises that a so-called rattling vibration is generated by a sudden change in the engine output when the accelerator pedal is suddenly depressed.
[0011]
In view of the above situation, the first invention according to claim 1 is based on the fact that it is better to obtain the transmission target input rotational speed from the steady target driving force and the target engine output from the transient target driving force. An object of the present invention is to propose a vehicle driving force control device that embodies this idea and solves the above-mentioned problems.
[0012]
The second aspect of the present invention is to propose a suitable calculation method of the transmission target input rotational speed obtained from the steady target driving force.
[0013]
The third aspect of the present invention is to propose one calculation method of the target engine output obtained from the transient target driving force.
[0014]
The fourth aspect of the present invention is to propose another calculation method of the target engine output obtained from the transient target driving force.
[0015]
According to a fifth aspect of the present invention, a vehicle driving force control device is proposed in which, when the target engine output is obtained from the transient target driving force, the engine output at which the fuel consumption is minimized can be set as the target engine output. Objective.
[0016]
The sixth aspect of the present invention is to propose yet another method of calculating the target engine output obtained from the transient target driving force.
[0017]
[Means for Solving the Problems]
  For these purposes, the vehicle driving force control apparatus according to the first invention
  A vehicle equipped with a power train that combines an engine whose output can be arbitrarily changed depending on factors other than the accelerator pedal operation and a continuously variable transmission,
  Determined based on accelerator pedal operation amount and vehicle speedDepending on vehicle driving conditions and driving conditionsAccordingSteady target driving forceWith a predetermined delay componentWith transient characteristicsAchieveForAchieve transient target driving forceFind the combination of transmission target input speed and target engine output,
  In the vehicle driving force control apparatus for controlling the shift of the continuously variable transmission so as to be the transmission target input rotational speed and controlling the output of the engine so as to be the target engine output,
  Obtaining the transmission target input rotational speed from the steady target driving force,
  The target engine outputThe aboveIt is characterized in that it is obtained from the transient target driving force.
[0018]
A driving force control apparatus for a vehicle according to a second aspect of the present invention is the first aspect of the invention,
When obtaining the transmission target input rotational speed, the steady target driving is performed based on the data representing the relationship between the vehicle speed, the driving force, and the engine rotational speed obtained based on the minimum fuel consumption line on the engine characteristic diagram. The transmission input rotational speed corresponding to the target engine rotational speed for generating the steady target driving force with minimum fuel consumption obtained from the force and the vehicle speed is configured as the transmission target input rotational speed. It is.
[0019]
A vehicle driving force control apparatus according to a third aspect of the present invention is the first aspect or the second aspect, wherein
In determining the target engine output, the target engine output is determined by dividing the transient target driving force by the actual transmission ratio of the continuously variable transmission.
[0020]
A vehicle driving force control apparatus according to a fourth aspect of the present invention is the first aspect or the second aspect, wherein
In determining the target engine output, the target engine output is determined by dividing the transient target driving force by the target speed ratio of the continuously variable transmission, which is the ratio of the transmission output speed to the transmission target input speed. It is characterized by comprising.
[0021]
A vehicle driving force control apparatus according to a fifth aspect of the present invention is the first aspect or the second aspect, wherein
When obtaining the target engine output, an engine output for generating the required horsepower obtained by multiplying the transient target driving force by a vehicle speed with minimum fuel consumption is obtained from an engine characteristic diagram, and the minimum fuel consumption engine output is set as the target engine output. It is characterized by having constituted so that it may determine.
[0022]
A vehicle driving force control apparatus according to a sixth aspect of the present invention is the first aspect or the second aspect, wherein
When determining the target engine output, the transient target driving force is sequentially divided by the speed ratio of the continuously variable transmission and the torque ratio of the transmission means between the engine and the continuously variable transmission to determine the target engine output. It is characterized by
[0023]
【The invention's effect】
  In the first invention,Determined based on accelerator pedal operation amount and vehicle speedDepending on vehicle driving conditions and driving conditionsAccordingSteady target driving forceTo achieve a transient characteristic with a predetermined delay componentAchieve transient target driving forceStrangeFind the combination of the speed target input speed and target engine output,
  Shift control of the continuously variable transmission is performed so that the transmission target input rotational speed is achieved, and engine output control is performed so that the target engine output is achieved, thereby performing integrated driving force control of the vehicle.
  The output from the engine controlled in this way is shifted by the continuously variable transmission that is shift-controlled as described above and becomes the output of the power train.
[0024]
  By the way, in the first invention, in particular, the transmission target input rotational speed is obtained from the steady target driving force, and the target engine output is obtained.TheBy determining from the transient target driving force,
  When the transmission target input speed is obtained from the transient target driving force, that is, when the accelerator pedal is depressed, the downshift is delayed by the above transient characteristics, resulting in a transient driving force shortage, Problems such as incurring a decrease in the driving speed, and the target time such as the minimum fuel consumption is not sufficiently achieved due to the longer time in the driving state that is out of the target such as the minimum fuel consumption when determining the transmission target input speed. Can be resolved,
  The problem in the case where the target engine output is obtained from the steady target driving force, that is, the problem that the engine output suddenly increases when the accelerator pedal is suddenly depressed can be solved.
[0025]
In the second aspect of the invention, when the transmission target input rotational speed is obtained from the steady target driving force, the relationship between the vehicle speed, the driving force, and the engine rotational speed obtained based on the minimum fuel consumption line on the engine characteristic diagram is obtained. Based on the data representing the transmission, the transmission input speed corresponding to the target engine speed for generating the steady target driving power at the lowest fuel consumption, which is obtained from the steady target driving power and the vehicle speed, is defined as the transmission target input speed. Because
The transmission target input rotation speed can be determined in such a manner that the minimum fuel consumption is achieved, and the improvement effect of the fuel consumption can be maximized.
[0026]
In the third invention, when obtaining the target engine output from the transient target driving force, the target engine output is obtained by dividing the transient target driving force by the actual transmission ratio of the continuously variable transmission.
The target engine output is adapted to the current shift state, and realistic engine output control is compensated.
[0027]
In the fourth aspect of the invention, when the target engine output is obtained from the transient target driving force, the transient target driving force is divided by the target speed ratio of the continuously variable transmission which is the ratio of the transmission output speed to the transmission target input speed. To obtain the target engine output,
The target engine output is obtained by pre-shifting to a gear ratio corresponding to the target input rotational speed of the transmission, and the engine output control preceding the shift control is compensated.
[0028]
In the fifth aspect of the invention, when obtaining the target engine output from the transient target driving force, the engine output for generating the required horsepower obtained by multiplying the transient target driving force by the vehicle speed with minimum fuel consumption is obtained from the engine characteristic diagram, Since the minimum fuel consumption engine output is set as the target engine output,
The target engine output can be determined in such a manner that the minimum fuel consumption is achieved, and the improvement effect of the fuel consumption can be maximized.
[0029]
In the sixth invention, when obtaining the target engine output from the transient target driving force, the transient target driving force is sequentially divided by the speed ratio of the continuously variable transmission and the torque ratio of the transmission means between the engine and the continuously variable transmission. The target engine output
The target engine output can be calculated more easily, which is very advantageous.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a power train of a vehicle provided with a driving force control device according to an embodiment of the present invention and its control system. The power train is composed of an engine 1 and a continuously variable transmission 2.
[0031]
The engine 1 includes a throttle valve 5 that is not linked to the accelerator pedal 3 that is operated by the driver, but is disconnected from the accelerator pedal 3 so that the opening degree is electronically controlled by the step motor 4.
Step motor 4 is set to target throttle opening (TVO^*) Set the throttle valve 5 to the target throttle opening TVO by setting it to the rotational position corresponding to the command.^*Thus, the output of the engine 1 can be controlled by factors other than the accelerator pedal operation.
[0032]
The continuously variable transmission 2 is a well-known V-belt continuously variable transmission, and is arranged in alignment with a primary pulley 7 that is drivingly coupled to the output shaft of the engine 1 via a torque converter 6 that is a fluid transmission means. A secondary pulley 8 and a V-belt 9 spanned between these pulleys are provided.
Then, a differential gear device 11 is drivingly coupled to the secondary pulley 8 via a final drive gear set 10, and a wheel (not shown) is driven to rotate.
[0033]
Of the flanges forming the V grooves of the primary pulley 7 and the secondary pulley 8 for the speed change of the continuously variable transmission 2, one movable flange is moved closer to the other fixed flange to make the V groove So that the width of the V-groove can be increased by narrowing or separating the width,
Both movable flanges are connected to the target gear ratio (i^*) Primary pulley pressure P from the hydraulic actuator 12 responding to the command_priAnd secondary pulley pressure P_secBy shifting the position to the position corresponding to the actual transmission ratio, the actual transmission ratio becomes the target transmission ratio i.^*It is assumed that the stepless speed change can be made to match
[0034]
Target throttle opening TVO^*And target gear ratio i^*Are calculated by the controller 13 respectively.
For this reason, the controller 13 has a signal from the accelerator opening sensor 14 that detects the depression position (accelerator opening) APS of the accelerator pedal 3, and
A signal from the throttle opening sensor 16 for detecting the throttle opening TVO;
Number of revolutions of primary pulley 7 (primary number of revolutions) N_priA signal from the primary pulley rotation sensor 17 for detecting
Secondary pulley 8 rotation speed (secondary rotation speed) N_secA signal from the secondary pulley rotation sensor 18 for detecting
A signal from the vehicle speed sensor 19 for detecting the vehicle speed VSP;
Engine speed N_eA signal from the engine rotation sensor 20 is detected.
[0035]
Based on these input information, the controller 13 performs the shift control of the continuously variable transmission 2 and the throttle opening control of the engine 1 as shown in the functional block diagram in FIG. 2 and in the flowchart of FIG. (Engine output control) shall be performed as follows.
First, as described with reference to the functional block diagram of FIG. 2, the steady target driving force calculation unit 21 is described in, for example, the above-mentioned document based on the accelerator opening APS detected by the sensor 14 and the vehicle speed VSP detected by the sensor 19. The minimum necessary steady target driving force T according to the driving state and driving conditions of the vehicle_SAsk for.
[0036]
In the transmission target input rotational speed calculation unit 22, the steady target driving force T_SBased on a map corresponding to, for example, data shown in FIG. 11, which is obtained from the engine characteristic diagram based on the vehicle speed detection value VSP by the sensor 19, the steady target driving force T is calculated based on the current vehicle speed VSP._SEngine speed N for generating low fuel consumption_eTarget value N_e ^*Next, target engine speed N_e ^*Transmission target input speed (target primary speed) N corresponding to_pri ^*Ask for.
[0037]
Here, the data of FIG. 11 will be described. This data is obtained from the engine characteristic diagram shown in FIG._SAnd engine speed N_eAnd the relationship.
FIG. 9 shows the engine speed N_eAnd engine output (torque) T_eIs expressed as an equal fuel consumption line α where the fuel consumption rate is the same, and an equal horsepower line β where the output horsepower is the same, and the fuel consumption rate is the best on each equal horsepower line β. The connected minimum fuel consumption line is indicated by δ.
As shown in FIG. 10, the individual points on the minimum fuel consumption line δ shown in FIG._eTo vehicle speed VSP and engine output (torque) T_eThe steady target driving force T_SThe vehicle speed VSP and engine output (torque) T, which are transferred to the two-dimensional coordinates replaced with_eWhen the combination is obtained, the result is as shown in FIG.
[0038]
And the engine speed N on the characteristic diagram for each gear ratio_eWhen the points where the two are equal are plotted, a certain engine speed N_eIn this case, the engine speed N is as shown by A in FIG._eEvery vehicle speed VSP and steady target driving force T_SThe minimum fuel consumption line δ in FIG. 9 can be represented by a line as shown in FIG.
In FIG. 11, for the sake of convenience, the engine speed N_eThe target engine speed N_e ^*It was written as.
[0039]
The vehicle speed VSP and the steady target driving force T_SAnd target engine speed N_e ^*According to the data representing the relationship between the current vehicle speed VSP and the steady target driving force T_SFor example, a case where the combination with the point Z corresponds to the point Z will be described. The steady target driving force T under the vehicle speed VSP_STarget engine speed N to generate the minimum fuel consumption_e ^*Can be obtained as a parameter value (engine speed) related to a line passing through the Z point in FIG.
In a continuously variable transmission vehicle, the torque converter 6 is in a lock-up state in which the input / output elements are directly connected for most of the time during power transmission. However, the transmission target input speed N_pri ^*The target engine speed N_e ^*Are treated as the same value.
[0040]
Transmission target input speed N searched as described above_pri ^*Is input to the target gear ratio calculation unit 23, which calculates the transmission target input rotational speed N._pri ^*Is the secondary rotational speed (transmission output rotational speed) N_secBy dividing by the transmission target input speed N_pri ^*Target gear ratio i corresponding to^*1 is output to the hydraulic actuator 12 as shown in FIG.^*Is achieved, that is, the target input speed N_pri ^*Shift so that is achieved.
[0041]
  AndFruitThe gear ratio calculating unit 25 is configured to detect the primary rotational speed (transmission input rotational speed) N detected by the sensor 17._pri Is the secondary rotational speed (transmission output rotational speed) N_sec The actual transmission ratio i of the continuously variable transmission 2 is divided by_T Ask for.
  The transient target driving force calculation unit 24 calculates the steady target driving force T._S The givenHas a lag componentThrough a filter that supports transient characteristics,Steady target driving force T_S In order to generate a transient target drive force T_SDIs calculated.
  The target engine output calculation unit 26 is configured to output the transient target driving force T described above._SDIs the actual gear ratio i_T The target engine output (torque) T by dividing by_e ^* Ask for.
[0042]
Target engine output T_e ^*Is input to the target throttle opening calculator 27, which calculates the target engine output T_e ^*Target throttle opening TVO^*1 is output to the step motor 4 as shown in FIG. 1, and the throttle valve 5 is set to the target throttle opening TVO.^*The opening degree is controlled so that
[0043]
According to the present embodiment as described above, the steady target driving force T obtained from the driving conditions and the traveling conditions._SIs generated with the lowest fuel consumption, and the steady target driving force T_SIs controlled with the above-mentioned predetermined transient characteristics, the transmission control of the continuously variable transmission and the throttle opening control of the engine are performed, so that both improvement in fuel efficiency and power performance without excess or deficiency can be achieved. At the same time, the driving force can be generated with a predetermined transient characteristic.
[0044]
And target engine speed N_e ^*(Transmission target input speed N_pri ^*) Steady target driving force T_SFrom the minimum fuel consumption correspondence map shown in FIG._e ^*Is the transient target driving force T_SDIs the actual gear ratio i_TSince it is determined by dividing by, the following effects are obtained.
That is, the target engine speed N_e ^*(Transmission target input speed N_pri ^*) Steady target driving force T_STherefore, the target rotational speed does not include a delay component due to the transient characteristic, and the transmission target input rotational speed N indicated by a solid line in FIG._pri ^*And gear ratio i_TAs is clear from the change over time, the downshift of the continuously variable transmission can be promptly performed when the accelerator pedal is depressed, and the actual driving force T in FIG._OAs can be seen from the change over time indicated by the solid line, the driving force can be quickly increased, and the actual driving force T caused by the downshift response delay can be obtained._OThe deficiency in driving force as indicated by the broken line can be solved.
[0045]
Further, as described above, since the downshift response delay is small, the target engine speed N_e ^*(Transmission target input speed N_pri ^*11) used for the determination of the minimum fuel consumption map shown in FIG. 11 is shortened, and the fuel efficiency improvement effect can be achieved as intended.
[0046]
Furthermore, target engine output T_e ^*Transient target driving force T_SDFrom the target engine output T in the time chart of FIG._e ^*And actual driving force T_OAs is clear from the change over time indicated by the solid line, the sudden change in the engine output when the accelerator pedal is suddenly depressed is less than the broken line characteristic, and the problem of so-called rattling vibration can be solved.
[0047]
FIG. 3 is a flowchart showing the above driving force control. In step 41, the accelerator opening APS, the vehicle speed VSP, the transmission input rotational speed N_pri, And transmission output speed N_secIs read.
Next, at step 42, the steady target driving force T is performed in the same manner as in the calculation unit 21 of FIG._SIn step 43, the transient target driving force T_SDIs obtained as follows.
[0048]
Step 43 corresponds to the calculation unit 24 of FIG. 2, but here, the transient target driving force T_SDAn example of the calculation formula is as follows.

[0049]
In step 44, the transmission target input rotational speed N is the same as in the calculation unit 21 of FIG._pri ^*Search the map and
In step 45, the actual transmission ratio i of the continuously variable transmission is the same as in the calculation unit 25 of FIG._T= N_sec/ N_priTo calculate
In step 46, the target engine output T is the same as in the calculation unit 26 of FIG._e ^*= T_SD/ I_Tcalculate.
[0050]
In step 47, the target speed ratio i is performed in the same manner as in the calculation unit 23 of FIG.^*= N_pri ^*/ N_sec1 is output to the hydraulic actuator 12 in FIG. 1, and the target engine output T is calculated in the same manner as in the calculation unit 27 in FIG._e ^*Target throttle opening TVO to generate^*Is output to the stepping motor 4 of FIG.
[0051]
FIG. 4 shows another embodiment of the present invention. In this embodiment, the target engine output T_e ^*Is calculated by another method different from the above.
That is, in the transmission target gear ratio calculation unit 31, the transmission target input rotation speed N from the calculation unit 22._pri ^*Of the transmission output speed N detected by the sensor 18_secBy dividing by the transmission target gear ratio i_T ^*To calculate
In the target engine output calculation unit 26, the transient target driving force T_SDThe transmission target gear ratio i_T ^*The target engine output T by dividing by_e ^*Asking for
Otherwise, the configuration is the same as in FIG.
[0052]
Also in the present embodiment, the transmission target input rotational speed N_pri ^*The steady target driving force T_SObtained from the target engine output T_e ^*Transient target driving force T_SDTherefore, the same effect as in the above embodiment can be obtained.
[0053]
The driving force control of FIG. 4 is shown in a flowchart as shown in FIG. 5, which corresponds to a case where steps 45 and 46 in FIG. 3 are replaced with steps 55 and 56.
Step 55 corresponds to the calculation unit 31 of FIG. 4. In this step 55, the transmission target input rotational speed N_pri ^*The transmission output speed N_secBy dividing by the transmission target gear ratio i_T ^*To calculate
Step 56 corresponds to the calculation unit 26 of FIG. 4. In this step 56, the transient target driving force T_SDThe transmission target gear ratio i_T ^*The target engine output T by dividing by_e ^*Ask for.
[0054]
FIG. 6 shows still another embodiment of the present invention. In this embodiment, the target engine output T_e ^*Is obtained as follows.
That is, the requested horsepower calculation unit 32 performs the transient target driving force T_SDVehicle speed VSP and constant K_DMultiplied by the transient target driving force T under the current vehicle speed VSP._SDDemand horsepower HP corresponding to_S= K_D・ T_SD• Find VSP.
[0055]
The target engine output calculation unit 33 calculates the required horsepower HP calculated based on the current vehicle speed VSP based on the engine characteristic diagram illustrated in FIG._S(Transient target driving force T_SD) Engine output T for generating minimum fuel consumption_eTarget value T_e ^*Ask for.
By the way, in the upper part of FIG._SIf the intersection of one equal horsepower line β and the minimum fuel consumption line δ corresponding to is the Z point in FIG. 9, for example, the required horsepower HP_STarget engine output T for generating low fuel consumption_e ^*As shown in FIG. 9, the scale value can be obtained as a scale value lowered from the Z point on the vertical axis.
The transmission target input speed N_pri ^*The calculation method is the same as in FIG. 2 and FIG.
[0056]
Also in the present embodiment, the transmission target input rotational speed N_pri ^*The steady target driving force T_SObtained from the target engine output T_e ^*Transient target driving force T_SDTherefore, the same operational effects as in the above embodiments can be obtained.
[0057]
The embodiment of FIG. 6 is shown in a flowchart as shown in FIG. 7, which corresponds to a case in which steps 45 and 46 in FIG.
Step 65 corresponds to the calculation unit 32 in FIG. 6. In this step 65, the transient target driving force T_SDVehicle speed VSP and constant K_DMultiplied by the transient target driving force T under the current vehicle speed VSP._SDDemand horsepower HP corresponding to_S= K_D・ T_SD• Find VSP.
Step 66 corresponds to the calculation unit 33 in FIG. 6, and in this step 66, based on the engine characteristic diagram illustrated in FIG._S(Transient target driving force T_SD) Target engine output T for generating minimum fuel consumption_e ^*Ask for.
[0058]
FIG. 8 shows the target engine output T_e ^*FIG. 6 is a flowchart corresponding to FIG. 3 showing still another embodiment of the present invention in which the above is calculated by another method.
In the present embodiment, at step 41, the engine speed N_eIn steps 42 to 44, as in FIG. 3, the steady target driving force T_S, Transient target driving force T_SDAnd transmission target input speed N_pri ^*In steps 71 and 72 after obtaining the primary rotational speed (torque converter output rotational speed) N_priThe engine speed (torque converter input speed) N_eThe torque converter speed ratio e = N by dividing by_pri/ N_eFurther, the torque ratio t of the torque converter is retrieved from the speed ratio e based on the characteristic diagram of the torque converter.
[0059]
Next, at step 45, as in FIG._T= N_pri/ N_secAfter calculating the transient target driving force T in step 46_SDIs the actual transmission ratio i of the continuously variable transmission_TAnd the target engine output N by sequentially dividing by the torque ratio t_e ^*Ask for.
In step 47, the target speed ratio i is obtained as in FIG.^*= N_pri ^*/ N_secIs output to the hydraulic actuator 12 of FIG. 1 and the target engine output T_e ^*Target throttle opening TVO to generate^*Is output to the stepping motor 4 of FIG.
[0060]
Also in the present embodiment, the transmission target input rotational speed N_pri ^*The steady target driving force T_SObtained from the target engine output T_e ^*Transient target driving force T_SDTherefore, the same operational effects as in the above embodiments can be obtained.
[0061]
According to each embodiment, the steady target driving force T_STo transmission target input speed N_pri ^*11 is obtained based on the minimum fuel consumption line δ on the engine characteristic diagram of FIG._SAnd engine speed N_eThe steady target driving force T based on the data representing the relationship between_SAnd the steady target driving force T obtained from the vehicle speed VSP_STarget engine speed N to generate the minimum fuel consumption_e ^*The transmission input rotational speed corresponding to the transmission target input rotational speed N_pri ^*To
The transmission target input rotation speed can be determined in such a manner that the minimum fuel consumption is achieved, and the improvement effect of the fuel consumption can be maximized.
[0062]
Transient target driving force T_SDTo target engine output T_e ^*2 and 3, the transient target driving force T is obtained as shown in FIGS._SDIs the actual transmission ratio i of the continuously variable transmission_TTarget engine output T by dividing by_e ^*To obtain the target engine output T_e ^*Is adapted to the current shift state, and realistic engine output control is compensated.
[0063]
Also, the transient target driving force T_SDTo target engine output T_e ^*4 and FIG. 5, the transient target driving force T is obtained._SDThe transmission target input speed N_pri ^*Output rotation speed N against_secThe target transmission ratio i of the continuously variable transmission that is the ratio of_T ^*Target engine output T by dividing by_e ^*To obtain the target engine output T_e ^*Is the target input speed N of the transmission_pri ^*Gear ratio i corresponding to_T ^*The engine output control preceding the shift control is compensated.
[0064]
Furthermore, the transient target driving force T_SDTo target engine output T_e ^*Is obtained as shown in FIG. 6 and FIG._SDRequired horsepower HP calculated by multiplying vehicle speed by VSP_SIs obtained from the engine characteristic diagram illustrated in FIG. 9, and the minimum fuel consumption engine output is determined as the target engine output T._e ^*Target engine output T_e ^*Can be determined in such a manner that the minimum fuel consumption is achieved, and the improvement effect of the fuel consumption can be maximized.
[0065]
Furthermore, the transient target driving force T_SDTo target engine output T_e ^*, The transient target driving force T as shown in FIG._SDThe gear ratio i of the continuously variable transmission_T(Target gear ratio i_T ^*Or the target engine output T by sequentially dividing by the torque converter torque ratio t._e ^*If you want
Target engine output T_e ^*Is more advantageous because it can be calculated more easily.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic explanatory view showing a power train of a continuously variable transmission equipped with a driving force control device according to an embodiment of the present invention together with its control system.
FIG. 2 is a functional block diagram of shift control and throttle opening control executed by a controller in the same embodiment;
FIG. 3 is a flowchart showing the shift control and throttle opening control of FIG. 2 as programs.
FIG. 4 is a functional block diagram of speed change control and throttle opening degree control showing another embodiment of the present invention.
FIG. 5 is a flowchart showing the shift control and throttle opening control of FIG. 4 as programs.
FIG. 6 is a functional block diagram of shift control and throttle opening control showing still another embodiment of the present invention.
7 is a flowchart showing the shift control and throttle opening control of FIG. 6 as programs.
FIG. 8 is a functional block diagram of speed change control and throttle opening control showing still another embodiment of the present invention.
FIG. 9 is an engine characteristic diagram showing an iso-fuel consumption line, an iso-horsepower line, and a minimum fuel consumption line on a two-dimensional coordinate defined by an engine speed axis and an engine output torque axis.
FIG. 10 is a diagram when the minimum fuel consumption line is rewritten as a relationship diagram between the vehicle speed and the axle driving force for each gear ratio.
FIG. 11 is a relationship diagram of vehicle speed, driving force, and engine speed, represented as a diagram connecting points at which the input rotation becomes equal for each gear ratio on the diagram of FIG.
FIG. 12 is a diagram showing an operation time chart according to the present invention in comparison with an operation time chart according to a conventional apparatus.
FIG. 13 is a diagram showing an operation time chart according to the present invention in comparison with an operation time chart according to another conventional apparatus.
[Explanation of symbols]
1 engine
2 continuously variable transmission
3 Accelerator pedal
4 Step motor
5 Electronically controlled throttle valve
6 Torque converter (transmission means)
7 Primary pulley
8 Secondary pulley
9 V belt
10 Final drive gear set
11 Differential gear unit
12 Hydraulic actuator
13 Controller
14 Accelerator position sensor
16 Throttle opening sensor
17 Primary pulley rotation sensor
18 Secondary pulley rotation sensor
19 Vehicle speed sensor
20 Engine rotation sensor
21 Steady target driving force calculator
22 Transmission target input speed calculator
23 Target gear ratio calculator
24 Transient target driving force calculator
25 Actual gear ratio calculator
26 Target engine output calculator
27 Target throttle opening calculator
31 Target gear ratio calculator
32 Required horsepower calculation section
33 Target engine output calculator

Claims (6)

A vehicle equipped with a power train that combines an engine whose output can be arbitrarily changed depending on factors other than the accelerator pedal operation and a continuously variable transmission,
The steady target driving force corresponding to the operating condition and traveling condition of the vehicle which is determined based on the accelerator pedal operation amount and the vehicle speed, the transmission to achieve the transient target drive force of the order to attain the transient characteristics having a predetermined delay components Find the combination of target input speed and target engine output,
In the vehicle driving force control apparatus for controlling the shift of the continuously variable transmission so as to be the transmission target input rotational speed and controlling the output of the engine so as to be the target engine output,
Obtaining the transmission target input rotational speed from the steady target driving force,
A driving force control apparatus for a vehicle, characterized in that the target engine output is obtained from the transient target driving force. The transmission target input rotational speed according to claim 1, wherein the transmission target input rotational speed is based on data representing a relationship between a vehicle speed, a driving force, and an engine rotational speed obtained based on a minimum fuel consumption line on an engine characteristic diagram. Driving force control for a vehicle, characterized in that it is configured to have a transmission input rotational speed corresponding to a target engine rotational speed for generating the steady target driving force with minimum fuel consumption, obtained from the steady target driving force and vehicle speed apparatus. 3. The vehicle driving force control device according to claim 1, wherein the target engine output is obtained by dividing the transient target driving force by an actual transmission ratio of a continuously variable transmission. 3. The target engine output according to claim 1, wherein the target engine output is obtained by dividing the transient target driving force by a target speed ratio of a continuously variable transmission that is a ratio of a transmission output speed to the transmission target input speed. A vehicle driving force control device configured as described above. 3. The engine output for generating a required horsepower obtained by multiplying the transient target driving force by a vehicle speed with minimum fuel consumption from an engine characteristic diagram according to claim 1 or 2, and the minimum fuel consumption engine output as the target engine output. A driving force control apparatus for a vehicle, characterized in that it is configured to be defined. 3. The target engine output is obtained by sequentially dividing the transient target driving force by a speed ratio of the continuously variable transmission and a torque ratio of the transmission means between the engine and the continuously variable transmission. A driving force control apparatus for a vehicle.

Images