JP3596318B2 - Control device for vehicle with continuously variable transmission - Google Patents

Description

で表される場合（ラプラス変換領域）、数式１よりエンジン軸トルクで考えたイナーシャトルクΔＴｅ＿ｉｎｅｒｔｉａは、
【数１２】

となる。
【００３６】
このイナーシャトルクΔＴｅ＿ｉｎｅｒｔｉａを打ち消すために、イナーシャトルクΔＴｅ＿ｉｎｅｒｔｉａと同一波形で、且つ増減の方向が逆方向となるように、エンジントルクを増減させる必要がある。上述した第１の実施の形態では、エンジンのトルク発生遅れを考慮せずにイナーシャトルクから直接スロットルバルブ開度指令値を求めるようにしたが、この実施の形態ではエンジンのトルク発生遅れを考慮する。具体的には、イナーシャトルクの位相よりエンジントルクの遅れ分だけ位相が進んだエンジントルク増減指令値を演算し、このエンジントルク増減指令値からスロットルバルブ開度指令値を求める。これにより、スロットルバルブ開度を増減する指令に対して、遅れて発生するエンジントルクの増減がイナーシャトルクを正確に打ち消すようになる。
【００３７】
位相調整機能と近似微分機能とを有するフィルターをＧｆｉｌ０（ｓ）とすると、エンジントルク増減指令値ΔＴｅ＿ｃｏｎｔｒｏｌは、
【数１３】

となる。数式１２と数式１３から、フィルターＧｆｉｌ０（ｓ）は、
【数１４】

となる。ここで、フィルターＧｆｉｌ０（ｓ）は、目標変速比から実変速比までの伝達特性による遅れの処理、近似微分処理、エンジンのトルク発生遅れ分だけエンジントルク増減指令値の位相をイナーシャトルクの位相より進ませる処理、の３つの処理を同時に行う機能を有するフィルターである。なお、目標変速比から実変速比までの伝達特性による遅れの処理と近似微分処理とを同時に目標変速比に施すことは、第１の実施の形態で説明したフィルターＮ（ｓ）を目標変速比に施す処理と同義であり、イナーシャトルクを求めることに相当する。
【００３８】
したがって、目標変速比Ｇｔに基づいてイナーシャトルクを打ち消すためのエンジントルク増減指令値を演算する場合には、数式１４で表されるフィルターＧｆｉｌ０（ｓ）を用いて次式によりエンジントルク増減指令値ΔｔＴｅを演算すればよい。
【数１５】

エンジントルク増減指令値ΔｔＴｅを算出したら、このΔｔＴｅに相当するスロットルバルブ開度の増減量を表引き演算し、その増減量を現在のスロットルバルブ開度に加えてスロットルバルブ開度指令値を求める。
【００３９】
このように、目標変速比Ｇｔにしたがって無段変速機の変速比を制御するとともに、変速比変化時のイナーシャトルクを補償するためのエンジントルク増減指令値を、位相調整機能と近似微分機能とを有するフィルターを目標変速比に施して演算する。そして、エンジントルク増減指令値に基づいてスロットルバルブ開度の増減量を表引き演算し、スロットルバルブ開度の増減量を現在のスロットルバルブ開度に加えてエンジンを制御するようにしたので、エンジンと無段変速機に遅れ要素があってもイナーシャトルクを正確に補償でき、運転性能を低下させずに無段変速機の変速比を操作することができる。
【００４０】
ここで、エンジン、電制スロットル、無段変速機（変速制御ロジックも含めて目標変速比Ｇｔから実変速比Ｇまで）の伝達特性の車両運転状態による変化が無視できない場合には、すべての車両運転状態でイナーシャトルクとエンジントルク増減量との位相を最適化するために、上記数式１１〜１５のパラメーターを、エンジン回転数Ｎｅ、負荷を表すＴＰ（吸入空気量検出値）、車速ＶＳＰ、変速比Ｇ、無段変速機のライン圧ＰＬ、油温Ｔｏなどに基づいて予め設定されたテーブルやマップ、あるいは数値演算により求め、車両の運転状態に応じて各パラメーターを切り換える構成とすればよい。
【００４１】
具体的には、例えばエンジンの吸気遅れの時定数ＴＥと、エンジントルクのむだ時間ＴＤは、それぞれエンジン回転数Ｎｅとの間に図１４と図１５に示すような関係がある。また、電制スロットルの遅れの時定数ＴＥＴＣはあまり車両運転状態に依存しないことが知られている。さらに、無段変速機本体の伝達関数ＧＣＶＴ（ｓ）を、
【数１６】

で表した場合に、パラメーターａ，ｂ，ｇ，ｆは図１６から図２０に示すような関係がある。したがって、車両の運転条件に応じたパラメーターａ，ｂ，ｇ，ｆを設定したＧｃｖｔ（ｓ）と変速制御ロジックの伝達関数とで数式１４のＰ（ｓ）を置き換えれば、車両の運転状態に適したフィルターＧｆｉｌ０（ｓ）を求めることができる。
【００４２】
このように、車両の運転状態に基づいて近似微分フィルターの演算式の係数を求めるようにしたので、エンジンや無段変速機の特性の車両運転状態による変化を補償することができ、イナーシャトルクを正確に補償することができる。
【００４３】
《発明の第３の実施の形態》
無段変速機の変速比を変えたときにエンジン側の等価イナーシャ変化に起因して発生するイナーシャトルクを補償するためのエンジントルク増減指令値（駆動源トルク増減指令値）を目標変速比に基づいて演算し、このエンジントルク増減指令値に基づいてスロットルバルブ開度指令値（出力増減量）を演算する第３の実施の形態を説明する。なお、この第３の実施の形態の構成は図１に示す第１の実施の形態の構成と同様であり、図示と説明を省略する。
【００４４】
この実施の形態では、変速比指令値Ｇｉから実変速比Ｇまでの伝達特性が、
【数１７】

で表され（ラプラス変換領域）、且つ、目標変速比Ｇｔと変速比指令値Ｇｉの関係が、
【数１８】

で表されるものとすると、数式１によりエンジン軸トルクで考えたイナーシャトルクΔＴｅ＿ｉｎｅｒｔｉａは、
【数１９】

となる。
【００４５】
このイナーシャトルクΔＴｅ＿ｉｎｅｒｔｉａを打ち消すために、イナーシャトルクΔＴｅ＿ｉｎｅｒｔｉａと同一波形で、且つ増減の方向が逆方向となるようにエンジントルクを増減させる必要がある。ここでは、エンジントルクの遅れを考慮するため、イナーシャトルクの位相よりエンジントルクの遅れ分だけ位相が進んだエンジントルク増減指令値をいったん演算し、このエンジントルク増減指令値からスロットルバルブ開度指令値を求めるようにする。これにより、スロットルバルブ開度を増減する指令に対して、遅れて発生するエンジントルクの増減がイナーシャトルクを正確に打ち消すようになる。
【００４６】
位相調整機能と近似微分機能とを有するフィルターをＧｆｉｌ１（ｓ）とすると、エンジントルク増減指令値ΔＴｅ＿ｃｏｎｔｒｏｌは、
【数２０】

となる。数式１９と数式２０から、フィルターＧｆｉｌ１（ｓ）は、
【数２１】

となる。ここで、フィルターＧｆｉｌ１（ｓ）は、目標変速比から実変速比までの伝達特性による遅れの処理、近似微分処理、エンジンのトルク発生遅れ分だけエンジントルク増減指令値の位相をイナーシャトルクの位相より進ませる処理、の３つの処理を同時に行う機能を有するフィルターである。
【００４７】
したがって、目標変速比Ｇｔに基づいてイナーシャトルクを打ち消すためのエンジントルク増減指令値を演算する場合には、数式２１で表されるフィルターＧｆｉｌ１（ｓ）を用いて次式によりエンジントルク増減指令値ΔｔＴｅを演算すればよい。
【数２２】

【００４８】
なお、数式２１がＭ（ｓ）なしでもプロパ（微分要素ｓの分子の次数が分母の次数以下）で実現可能な場合は、変速比指令値Ｇｉに基づいてイナーシャトルクを演算することができる。その場合は、位相調整機能と近似微分機能とを有するフィルターを、
【数２３】

とし、エンジントルク増減量ΔｔＴｅを、
【数２４】

により演算する。
【００４９】
このように、目標変速比Ｇｔに到達するまでの変速比の時間的な変化を制限するための変速比指令値Ｇｉを設定し、変速比指令値Ｇｉにしたがって無段変速機の変速比を制御するとともに、変速比変化時のイナーシャトルクを変速比指令値Ｇｉに基づいて演算する。そして、このイナーシャトルクを補償するためのエンジントルク増減指令値を、位相調整機能と近似微分機能とを有するフィルターを変速比指令値Ｇｉに施して演算し、エンジントルク増減指令値に応じてエンジンを制御するようにしたので、エンジンや無段変速機の駆動系に遅れ要素があってもイナーシャトルクを打ち消すためのエンジントルク増減指令値を正確に求めることができ、イナーシャトルクを正確に補償して運転性能を低下させずに無段変速機の変速比を操作することができる。
【００５０】
ここで、エンジン、電制スロットル、無段変速機（変速制御ロジックも含めて目標変速比Ｇｔから実変速比Ｇまで）の伝達特性の車両運転状態による変化が無視できない場合には、すべての車両運転状態でイナーシャトルクとエンジントルク増減量との位相を最適化するために、上記数式１７〜２４のパラメーターを、エンジン回転数Ｎｅ、負荷を表すＴＰ（吸入空気量検出値）、車速ＶＳＰ、変速比Ｇ、無段変速機のライン圧ＰＬ、油温Ｔｏなどに基づいて予め設定されたテーブルやマップ、あるいは数値演算により求め、車両の運転状態に応じて各パラメーターを切り換える構成とすればよい。具体的な演算方法は上述した第２の実施の形態の演算方法と同様であり、説明を省略する。
【００５１】
《発明の第４の実施の形態》
上記第２および第３の実施の形態で用いた、位相調整機能と近似微分機能とを有するフィルターＧｆｉｌ０（ｓ）、Ｇｆｉｌ１（ｓ）、Ｇｆｉｌ２（ｓ）は、オンラインでその演算を実行するには次数が高いので、公知の「周波数重みつき平衡実現」などの手法により低次元化し、次式に示すようなフィルターＧｆｉｌ（ｓ）とする。
【数２５】

ここで、Ｔｒｅｄは時定数である。このフィルターＧｆｉｌ（ｓ）を用いてエンジントルク増減量ΔｔＴｅを、
【数２６】

により演算する。
【００５２】
ここで、数式２５により近似した場合、時定数Ｔｒｅｄは主にエンジン回転数Ｎｅと負荷を表すＴＰ（吸入空気量検出値）とに依存することがわかっており、その関係は図２１に示すようになる。したがって、すべての車両運転状態でイナーシャトルクとそれを補償するためのエンジントルク増減量との位相を最適化するには、時定数Ｔｒｅｄをエンジン回転数Ｎｅと負荷を表すＴＰ（吸入空気量検出値）に基づいて予め設定されたテーブルやマップを参照し、車両運転状態によって各パラメーターを切り換えるようにすればよい。
【００５３】
このように、近似微分フィルターを低次のフィルターに近似してエンジントルク増減量の演算を行うようにしたので、演算を実行するマイクロコンピューターの負担を軽減できる上に、演算処理の高速化を図ることができ、変速比の速い変化に対してもイナーシャトルクを補償するためのエンジントルク増減量を正確に求めることができる。
【００５４】
《発明の第５の実施の形態》
上述した第４の実施の形態において、図２１に示す時定数Ｔｒｅｄが主にエンジン回転数Ｎｅに依存し、負荷へはほとんど依存しないと見なせる場合には、時定数Ｔｒｅｄを図２２に示すようなエンジン回転数Ｎｅにのみ依存するテーブル値としてもよい。これにより、マイクロコンピューターによる演算処理の負担を軽減でき、演算処理の高速化を図りながらイナーシャトルクを正確に補償することができる。
【００５５】
なお、上述した第２〜第５の実施の形態では、無段変速機の伝達特性による遅れの処理、近似微分処理、エンジンのトルク発生遅れ処理、の３つの処理を同時に行う機能を有するフィルターを用いてエンジントルク増減指令値を演算するようにしたが、第１の実施の形態で説明した方法によって、まずイナーシャトルクを演算し、このイナーシャトルクにエンジンのトルク発生遅れの処理を行うフィルターを施してエンジントルク増減指令値を演算するようにしてもよい。
【図面の簡単な説明】
【図１】一実施の形態の構成を示す図である。
【図２】エンジンの構造を示す図である。
【図３】無段変速機の構造を示す図である。
【図４】制御装置の変速制御を示す制御ブロック図である。
【図５】目標変速比演算手順を示すフローチャートである。
【図６】車速とアクセルペダル操作量に対する無段変速機入力軸回転速度の特性マップを示す図である。
【図７】スロットルバルブ開度とエンジン回転速度に対するエンジントルクの特性マップを示す図である。
【図８】変速比を１．０から２．０へ２秒間で変速する場合に、０．０１の分散の正規分布のノイズが混入した計測値を示す図である。
【図９】図８に示す計測値に対してサンプリング時間ごとの偏差（差分）を近似的に変速比微分値（ｄＧ／ｄｔ）と見なした特性図である。
【図１０】図８に示すノイズが重畳した変速比計測値に対し、所定のフィルター処理を施した特性図である。
【図１１】図１０に示すフィルター処理後の変速比の、サンプリング時間ごとの偏差（差分）を近似的に変速比微分値（ｄＧ／ｄｔ）と見なした特性図である。
【図１２】図１０に対してフィルター特性を変えた場合の特性図である。
【図１３】図１１に対してフィルター特性を変えた場合の特性図である。
【図１４】エンジン回転数Ｎｅとエンジンの吸気遅れ時定数ＴＥとの関係を示す図である。
【図１５】エンジン回転数Ｎｅとエンジントルクのむだ時間ＴＤとの関係を示す図である。
【図１６】無段変速機のライン圧、油温および負荷とパラメーターａとの関係を示す図である。
【図１７】無段変速機のライン圧、油温および負荷とパラメーターｂとの関係を示す図である。
【図１８】無段変速機のライン圧および油温とパラメーターｇとの関係を示す図である。
【図１９】無段変速機のライン圧および負荷とパラメーターｇとの関係を示す図である。
【図２０】車速とパラメーターｆとの関係を示す図である。
【図２１】エンジン回転数Ｎｅおよび負荷とパラメーターＴｒｅｄとの関係を示す図である。
【図２２】エンジン回転数ＮｅとパラメーターＴｒｅｄとの関係を示す図である。
【符号の説明】
１ エンジン
２ トルクコンバーターおよび正逆切換機構
３ 無段変速機
４ 最終減速機および差動機構
５ 駆動輪
６ エンジンコントローラー
７ 無段変速機コントローラー
８ 制御装置
８ａ 目標変速比演算部
８ｂ 変速比指令値設定部
８ｃ イナーシャトルク演算部
８ｄ 駆動力補償量演算部
９ アクセルセンサー
１０ 車速センサー
１１ 車輪速センサー
１２ エンジン回転センサー[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a control device for a vehicle provided with a continuously variable transmission, and more particularly, to improving a decrease in driving performance when a gear ratio is changed.
[0002]
[Conventional technology and its problems]
In a vehicle equipped with a continuously variable transmission, the following phenomenon may occur when the gear ratio is operated.
(1) If the transmission is downshifted during acceleration, the equivalent inertia of the drive system increases, causing an insufficient acceleration force during gear shifting, causing the occupant to feel a poor acceleration feeling.
(2) When the transmission is upshifted during a transition from an acceleration state to a steady state, for example, the equivalent inertia of the drive system is reduced, and the vehicle is accelerated during the gear shift, giving an uncomfortable feeling to the occupant.
[0003]
In order to prevent a decrease in driving performance when such a gear ratio is operated, a control device that controls a gear speed in consideration of a torque (hereinafter, referred to as inertia torque) apparently generated by a change in equivalent inertia has been developed. It has been proposed (see, for example, JP-A-7-239002).
In this control device, the shift speed is adjusted in accordance with the operating conditions, specifically, the transmission output shaft rotation speed (∝vehicle speed) so that the inertia torque does not increase by a predetermined value or more.
[0004]
Also proposed is a control device that delays the ignition timing before starting the downshift to reduce engine torque, stops the ignition timing in accordance with the change in the gear ratio after the start of shifting, and compensates for inertia torque. (See, for example, Japanese Patent Application Laid-Open No. 8-177541).
[0005]
However, the former control device that suppresses the inertia torque by lowering the shift speed has a problem that the acceleration during the downshift becomes slow and a sufficient feeling of acceleration cannot be obtained.
Therefore, like the latter control device, it is necessary to compensate for the inertia torque by some method while maintaining the shift speed, and to operate the speed ratio without sacrificing the feeling of acceleration.
[0006]
Here, the inertia torque generated due to the change of the engine-side equivalent inertia when the gear ratio is changed is expressed by the following equation.
(Equation 1)
J1 * ωw * Gf * (dG / dt)
In Equation 1, J1 is the moment of inertia on the input side of the engine and the continuously variable transmission, ωw is the angular velocity of the drive wheel, Gf is the reduction ratio of the final reduction gear, and G is the speed ratio of the continuously variable transmission.
[0007]
By the way, since the measured value of the gear ratio includes a measurement error and noise, accurate compensation cannot be performed if the inertia torque is compensated based on such a measured value. In particular, as for the term of the differential value (dG / dt) of the gear ratio, the influence of measurement error and noise increases, and not only a desired result cannot be obtained, but also the driving performance may be deteriorated.
[0008]
FIG. 8 shows a measured value in which noise of a normal distribution with a variance of 0.01 is mixed when shifting from a reduction ratio of 1.0 to 2.0 in two seconds. FIG. 9A is a characteristic diagram in which a deviation (difference) for each sample time is approximately regarded as a gear ratio differential value (dG / dt) with respect to the true value of the measured value shown in FIG. FIG. 9B shows a characteristic in which a deviation (difference) for each sample time from the measured value shown in FIG. 8 is approximately regarded as a gear ratio differential value (change ratio of gear ratio) (dG / dt). FIG. FIG. 9B shows a value which is larger than that of FIG. 9A by one digit or more and has no meaning. When this value is used as the gear ratio differential value (dG / dt) of Expression 1, an accurate inertia torque is obtained. I can't get it.
[0009]
On the other hand, it is conceivable to apply a filtering process to the measured gear ratio to reduce noise components.
FIG. 10 is a characteristic diagram in which a predetermined filter process is performed on the gear ratio measurement value on which the noise shown in FIG. 8 is superimposed. When filter processing is performed on the gear ratio measurement value, the dispersion of the signal is reduced, but the measured value b after the filter processing is out of phase with the true value a.
FIG. 11 is a characteristic diagram in which a deviation (difference) of the gear ratio after the filtering process shown in FIG. 10 for each sample time is approximately regarded as a gear ratio differential value (dG / dt). Although the influence of noise is reduced as compared with FIGS. 9A and 9B, there is still a considerable fluctuation, and this cannot be used as the gear ratio differential value (dG / dt) in Expression 1. .
[0010]
Further, FIGS. 12 and 13 show filter characteristics different from those of FIGS. Although the variation in the signal is suppressed, the phase shift increases, and the compensation accuracy further deteriorates due to the phase shift.
[0011]
An object of the present invention is to operate the speed ratio of a continuously variable transmission without deteriorating driving performance.
[0012]
[Means for Solving the Problems]
(1) The invention of claim 1 isContinuously variable transmission for continuously changing the output of the drive source, transmission control means for controlling the speed ratio of the continuously variable transmission according to the target speed ratio, and shifting of the continuously variable transmission based on the target speed ratio A drive source torque increase / decrease command value calculating means for calculating a drive source torque increase / decrease command value for compensating for inertia torque generated due to a change in the drive source side equivalent inertia when the ratio is changed, and a drive source torque increase / decrease command An output increase / decrease amount calculating means for calculating the output increase / decrease amount of the drive source based on the value; and a drive source control means for controlling the drive source in accordance with the output increase / decrease amount. A phase adjustment function for performing phase adjustment with respect to a delay due to transmission characteristics from the target speed ratio to the actual speed ratio of the stepped transmission, a torque generation delay of the drive source, and a delay of the electronically controlled throttle, and an approximate differentiation function. Fill with Subjecting the target speed ratio to approximate the over to low-order filter, it calculates a drive source torque decrease command value.
(2) Claim 2The present invention relates to a continuously variable transmission for continuously changing the output of a drive source, and a speed ratio command value for setting a speed ratio command value for limiting a temporal change of a speed ratio until a target speed ratio is reached. Setting means, transmission control means for controlling the speed ratio of the continuously variable transmission in accordance with the speed ratio command value, and an equivalent drive source when the speed ratio of the continuously variable transmission is changed based on the speed command value. A drive source torque increase / decrease command value calculating means for calculating a drive source torque increase / decrease command value for compensating for inertia torque generated due to the inertia change, and a drive source output increase / decrease amount based on the drive source torque increase / decrease command value. A drive source control means for controlling a drive source according to the output increase / decrease amount, wherein the drive source torque increase / decrease command value calculation means calculates the actual gear ratio from the target gear ratio of the continuously variable transmission. Delay due to transmission characteristics up to A filter having a phase adjustment function for performing phase adjustment with respect to a torque generation delay of the source and a delay of the electronic control type throttle and an approximate differentiation function is applied to a gear ratio command value by approximating the filter to a lower-order filter. Calculate the source torque increase / decrease command value.
[0013]
【The invention's effect】
(1) According to the invention of claim 1,It can accurately compensate for inertia torque and can operate the speed ratio of a continuously variable transmission without deteriorating driving performance.In addition, there is a delay element in the drive source, the continuously variable transmission, and the electronically controlled throttle. Even if it does, the inertia torque can be compensated accurately.
(2) According to the invention of claim 2,In addition to being able to accurately compensate for inertia torque caused by gear ratio changes, it is possible to operate the gear ratio of a continuously variable transmission without deteriorating driving performance, and to provide a drive source, a continuously variable transmission, and an electronically controlled system. Even if there is a delay element in the throttle, the inertia torque can be accurately compensated.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment in which the present invention is applied to a vehicle using an internal combustion engine as a driving source for driving will be described. The present invention can be applied to an electric vehicle using an electric motor as a driving source, or a hybrid vehicle using an internal combustion engine and an electric motor as a driving source. In addition, the present invention can be applied to a vehicle that is propelled by a hydraulic source and a vehicle that uses energy stored in a flywheel as a power source.
[0015]
<< First Embodiment of the Invention >>
FIG. 1 is a diagram showing a configuration of an embodiment.
The driving force of the engine 1 is transmitted to driving wheels 5 via a torque converter and a forward / reverse switching mechanism 2, a continuously variable transmission 3, a final reduction gear, and a differential mechanism 4. A gasoline engine or a diesel engine can be used as the engine 1, and the engine controller 6 performs fuel injection control, ignition timing control, throttle valve control, and the like. As the continuously variable transmission 3, a toroidal type or a belt type can be used, and the speed ratio is continuously adjusted by the continuously variable transmission controller 7. The control device 8 includes a microcomputer and its peripheral components, and performs comprehensive vehicle control. The control device 8 includes an accelerator sensor 9 for detecting an operation amount of an accelerator pedal (not shown) by an occupant, a vehicle speed sensor 10 for detecting a vehicle speed, and a wheel speed sensor for detecting an angular speed of the driving wheel 5. 11 and an engine rotation sensor 12 for detecting the rotation speed of the engine 1 are connected.
[0016]
FIG. 2 is a diagram showing the structure of the engine 1.
This embodiment shows an example using a gasoline engine. This gasoline engine 1 is provided with an electronically controlled throttle that opens and closes a throttle valve 1a by a motor 1b. The engine controller 6 drives and controls the opening of the throttle valve 1a according to the throttle valve opening command value from the control device 8. The other components of the engine 1 are well known, and a description thereof will be omitted.
[0017]
FIG. 3 is a diagram showing the structure of the continuously variable transmission 3.
This embodiment shows an example in which a toroidal type continuously variable transmission is used. A torque converter 2a and a forward / reverse switching mechanism 2b are arranged on the output shaft side of the engine 1, and a toroidal type continuously variable transmission 3 is arranged at a subsequent stage. The transmission controller 7 controls the speed ratio of the continuously variable transmission 3 according to the speed ratio command value from the control device 8. The structure of the toroidal-type continuously variable transmission is well known, and the description is omitted.
[0018]
FIG. 4 is a control block diagram of the control device 8.
The control device 8 includes control blocks 8a to 8d in the form of microcomputer software. The target gear ratio calculation unit 8a sets a target input shaft rotation speed (hereinafter simply referred to as a target input rotation speed) of the continuously variable transmission 3 based on the operation amount of the accelerator pedal by the occupant and the vehicle speed, and sets the target input rotation. The target gear ratio Gt is calculated from the number and the vehicle speed.
[0019]
FIG. 5 is a flowchart showing the procedure for calculating the target gear ratio. The procedure will be described with reference to this flowchart.
In step 1, the accelerator sensor 9 detects the amount of operation of the accelerator pedal, and in step 2, the vehicle speed sensor 10 detects the vehicle speed Vsp. In step 3, a target input rotation speed Ni corresponding to the detected accelerator pedal operation amount and vehicle speed Vsp is obtained from a map of the target input rotation speed of the continuously variable transmission 3 with respect to a preset accelerator pedal operation amount and vehicle speed (see FIG. 6). Is calculated. The map shown in FIG. 6 is set in advance and stored in the memory of the control device 8. In step 4, the target speed ratio Gt is calculated by the following equation based on the target input speed Ni and the vehicle speed Vsp.
(Equation 2)
Gt = Ni / Vsp * k1
In Equation 2, k1 is a constant selected from the final reduction ratio or unit conversion between the target input rotation speed Ni and the vehicle speed Vsp.
[0020]
The speed ratio command value setting unit 8b is configured to set a speed change for limiting a time change of the speed ratio until the speed ratio of the continuously variable transmission 3 reaches the target speed ratio Gt when the speed ratio of the continuously variable transmission 3 matches the target speed ratio Gt. The ratio command value Gi is set. The setting method includes the following method.
[0021]
The first setting method is a method of setting the speed ratio command value Gi using a simple first-order lag transfer function that receives the target speed ratio Gt.
(Equation 3)
Gi = 1 / (1 + Ts) * Gt
In Equation 3, T is the time constant of the first-order lag transfer function, and s is the Laplace operator.
[0022]
A second setting method is a method of setting the gear ratio command value Gi in a ramp manner from the gear ratio command value Gi (k-1) at the time of the previous sampling and the target gear ratio Gtk at the time of the current sampling by the following equation. is there.
(Equation 4)
Gi = Gi (k−1) + sign (Gtk−Gi (k−1)) * min (ΔG, | Gtk−Gi (k−1) |)
In Expression 4, sign represents the sign of the calculation result of (Gtk-Gi (k-1)), and min represents that the smaller of ΔG and | Gtk-Gi (k-1) | is selected.
[0023]
The third setting method includes a reference model R1 (s) that expresses a desirable change in the speed ratio until the target speed ratio Gt is reached, and an estimation model R2 (s) of the transfer characteristic of the continuously variable transmission 3. Is a method of setting the gear ratio command value Gi based on
(Equation 5)
Gi = R1 (s) / R2 (s) * Gt
[0024]
The fourth setting method is to set a gear ratio command value Gi by applying a filter of the reference model characteristic M (s) to the target gear ratio Gt. In practice, a digital filter obtained by converting the reference model characteristic Gm (s) described in the continuous time system to the discrete time system is applied to the target speed ratio Gt. The reference model characteristic M (s) is
(Equation 6)
M (s) = 1 / (1 + T1s)
In this case, the gear ratio command value Gi is expressed by the following equation.
(Equation 7)
Gi = A * Gt (k-1) + B * Gi (k-1)
In Equation 6, T1 is a time constant of the temporary delay transfer function, and s is a Laplace operator. In Equation 7, Gi (k-1) is the target gear ratio at the previous sampling, Gi (k-1) is the gear ratio command value at the previous sampling, and
(Equation 8)
B = exp (−Ts / T1),
A = 1-B
Here, Ts is a sampling period.
[0025]
The speed ratio command value setting unit 8b outputs the speed ratio command value Gi to the continuously variable transmission controller 7 and the inertia torque calculation unit 8c. The continuously variable transmission controller 7 drives and controls the continuously variable transmission 3 so that the gear ratio matches the target value Gi.
[0026]
Next, a method of calculating inertia torque in the inertia torque calculation unit 8c will be described.
The inertia torque generated due to the change of the engine-side equivalent inertia when the gear ratio is changed is expressed by the gear ratio change rate (dG / dt) of the above-described equation (1).
(Equation 9)
(DG / dt) = (Gik−Gi (k−1)) / Δt
Can be calculated by substituting In Expression 9, Δt is a sampling time.
[0027]
As described above, when the gear ratio is changed, inertia torque occurs due to a change in the equivalent inertia on the engine side, and the driving performance deteriorates. Therefore, a decrease in driving performance can be avoided by increasing or decreasing the output torque of the engine so as to cancel the inertia torque generated during shifting.
The driving force compensation amount calculation unit 8d displays the throttle valve opening for increasing or decreasing the engine torque corresponding to the inertia torque at the current engine rotation speed from the characteristic map of the engine 1 measured in advance (see FIG. 7). A subtraction operation is performed, and the increase / decrease amount is added to the current throttle valve opening to obtain a throttle valve opening command value. Then, the throttle valve opening command value is output to the engine controller 6. The engine controller 6 controls the driving of the motor 1b so that the opening of the throttle valve 1a matches the command value.
[0028]
In this manner, the gear ratio command value Gi for limiting the time change of the gear ratio until the gear ratio reaches the target gear ratio Gt is set, and when the gear ratio of the continuously variable transmission is changed, the engine side equivalent is changed. The inertia torque generated due to the inertia change is calculated based on the gear ratio command value Gi. Then, the amount of increase or decrease of the engine torque for compensating for this inertia torque is calculated, and the engine is controlled according to the amount of increase or decrease of the engine torque. In addition, the speed ratio of the continuously variable transmission can be operated without lowering the driving performance without being accelerated during the upshift.
[0029]
In the configuration of the above embodiment, the continuously variable transmission 3 is a continuously variable transmission, the engine 1 is a traveling drive source, the continuously variable transmission controller 7 is a transmission control unit, and the control device 8 is an inertia torque calculation. The means, the output increase / decrease amount calculating means and the gear ratio command value setting means, and the engine controller 6 constitute the drive source control means.
[0030]
In the above-described embodiment, the example in which the engine torque is adjusted by controlling the amount of air taken into the engine by the electronically controlled throttle has been described. However, the engine torque is adjusted by controlling the amount of fuel supplied to the engine. You may do so.
[0031]
Further, in the above-described embodiment, the speed ratio command value Gi for limiting the time change of the speed ratio until reaching the target speed ratio Gt is set, and the rate of change of the speed ratio command value Gi ( Although the example in which the inertia torque is calculated based on (dGi / dt) has been described, the inertia torque may be calculated based on the rate of change (dGt / dt) of the target gear ratio Gt.
[0032]
For example, a value obtained by applying a filter of approximate differential N (s) = s * M (s) using the reference model characteristic to the target speed ratio Gt is substituted for the speed ratio change rate (dG / dt) in Expression 1. In practice, a digital filter obtained by converting the approximate differential N (s) described in the continuous time system into the discrete time system is applied to the target speed ratio Gt.
(Equation 10)
N (s) = s / (1 + T1s),
(DG / dt) = C * Gt (k) + D * Gt (k-1) + E * (dG / dt) (k-1),
C = (1-exp (-Ts / T1)) / Ts,
D = (exp (−Ts / T1) −1) / Ts,
E = exp (-Ts / T1)
Note that Ts is a sampling cycle.
[0033]
<< Second Embodiment of the Invention >>
An engine torque increase / decrease command value (drive source torque command value) for compensating for an inertia torque generated due to an equivalent inertia change on the engine side when the speed ratio of the continuously variable transmission is changed based on the target speed ratio. A second embodiment for calculating the throttle valve opening command value (output increase / decrease amount) based on the engine torque increase / decrease command value will be described. The configuration of the second embodiment is the same as the configuration of the first embodiment shown in FIG. 1, and illustration and description are omitted.
[0034]
Here, TE is the time constant of the intake delay of the engine from the change in the opening of the throttle valve to the actual change in the intake amount of the cylinder, and the air and fuel are sucked into the cylinder and then actually burn to generate torque. Let TD be the dead time of the engine torque until the engine torque rises. In addition, the time constant of the delay of the electronically controlled throttle (electronically controlled throttle) from the throttle valve opening command to the actual opening of the throttle valve at the command value is set to TETC. The time constant of the shift delay of the continuously variable transmission until the gear ratio G changes is TCVT.
[0035]
The transmission characteristic from the target speed ratio Gt to the actual speed ratio G is
[Equation 11]

(Laplace transform region), the inertia torque ΔTe_inertia considered from the engine shaft torque from Equation 1 is
(Equation 12)

It becomes.
[0036]
In order to cancel the inertia torque ΔTe_inertia, it is necessary to increase or decrease the engine torque so that the inertia torque ΔTe_inertia has the same waveform as that of the inertia torque ΔTe_inertia and the direction of increase / decrease is in the opposite direction. In the above-described first embodiment, the throttle valve opening command value is directly obtained from the inertia torque without considering the engine torque generation delay. However, in this embodiment, the engine torque generation delay is considered. . Specifically, an engine torque increase / decrease command value whose phase is advanced by an engine torque delay from the inertia torque phase is calculated, and a throttle valve opening command value is obtained from this engine torque increase / decrease command value. As a result, an increase or decrease in the engine torque generated with a delay in response to a command to increase or decrease the throttle valve opening accurately cancels the inertia torque.
[0037]
Assuming that the filter having the phase adjustment function and the approximate differentiation function is Gfil0 (s), the engine torque increase / decrease command value ΔTe_control is
(Equation 13)

It becomes. From Equations 12 and 13, the filter Gfil0 (s) is
[Equation 14]

It becomes. Here, the filter Gfil0 (s) processes the delay due to the transmission characteristic from the target gear ratio to the actual gear ratio, approximate differential processing, and shifts the phase of the engine torque increase / decrease command value by the amount of the engine torque generation delay from the phase of the inertia torque. This is a filter having a function of simultaneously performing the three processes of advancing. Simultaneously performing the delay processing based on the transfer characteristic from the target gear ratio to the actual gear ratio and the approximate differential processing on the target gear ratio is performed by using the filter N (s) described in the first embodiment with the target gear ratio. Is equivalent to obtaining the inertia torque.
[0038]
Therefore, when calculating the engine torque increase / decrease command value for canceling the inertia torque based on the target gear ratio Gt, the engine torque increase / decrease command value ΔtTe is calculated by the following equation using the filter Gfil0 (s) expressed by Expression 14. May be calculated.
(Equation 15)

After calculating the engine torque increase / decrease command value ΔtTe, the amount of increase / decrease of the throttle valve opening corresponding to this ΔtTe is calculated by lookup, and the increase / decrease amount is added to the current throttle valve opening to obtain a throttle valve opening command value.
[0039]
As described above, while controlling the speed ratio of the continuously variable transmission in accordance with the target speed ratio Gt, the engine torque increase / decrease command value for compensating for the inertia torque at the time of the speed ratio change is determined by the phase adjustment function and the approximate differential function. The calculation is performed by applying the filter having the target speed ratio. Then, based on the engine torque increase / decrease command value, the amount of increase / decrease of the throttle valve opening is tabulated, and the engine is controlled by adding the amount of increase / decrease of the throttle valve opening to the current throttle valve opening. Even if there is a delay element in the continuously variable transmission, the inertia torque can be accurately compensated, and the speed ratio of the continuously variable transmission can be operated without deteriorating the driving performance.
[0040]
If the change in the transmission characteristics of the engine, the electronically controlled throttle, and the continuously variable transmission (from the target gear ratio Gt to the actual gear ratio G including the gear change control logic) due to the vehicle driving state cannot be ignored, all vehicles In order to optimize the phase between the inertia torque and the engine torque increase / decrease amount in the operating state, the parameters of the above formulas 11 to 15 are set by changing the engine speed Ne, the load TP (detected value of intake air amount) representing the load, the vehicle speed VSP, and the speed change. The configuration may be such that a parameter is switched according to the driving state of the vehicle by obtaining a preset table or map or numerical calculation based on the ratio G, the line pressure PL of the continuously variable transmission, the oil temperature To, and the like.
[0041]
Specifically, for example, the time constant TE of the intake delay of the engine and the dead time TD of the engine torque have a relationship as shown in FIGS. 14 and 15, respectively, with the engine speed Ne. It is also known that the time constant TETC of the delay of the electronically controlled throttle does not depend much on the vehicle operating state. Further, the transfer function GCVT (s) of the continuously variable transmission body is
(Equation 16)

Where parameters a, b, g, and f have a relationship as shown in FIGS. Therefore, if P (s) in Equation 14 is replaced with Gcvt (s) in which parameters a, b, g, and f according to the driving conditions of the vehicle are set and the transfer function of the shift control logic, the system is suitable for the driving state of the vehicle. Filter Gfil0 (s) can be obtained.
[0042]
As described above, since the coefficients of the arithmetic expression of the approximate differential filter are obtained based on the driving state of the vehicle, changes in the characteristics of the engine and the continuously variable transmission due to the driving state of the vehicle can be compensated. It can be compensated accurately.
[0043]
<< Third Embodiment of the Invention >>
An engine torque increase / decrease command value (drive source torque increase / decrease command value) for compensating for inertia torque generated due to an equivalent inertia change on the engine side when the speed ratio of the continuously variable transmission is changed is based on the target speed ratio. A third embodiment in which a throttle valve opening command value (output increase / decrease amount) is calculated based on the engine torque increase / decrease command value will be described. The configuration of the third embodiment is the same as the configuration of the first embodiment shown in FIG.
[0044]
In this embodiment, the transmission characteristic from the gear ratio command value Gi to the actual gear ratio G is:
[Equation 17]

(Laplace conversion region), and the relationship between the target speed ratio Gt and the speed ratio command value Gi is
(Equation 18)

Assuming that the inertia torque ΔTe_inertia considered by the engine shaft torque according to Equation 1 is
[Equation 19]

It becomes.
[0045]
In order to cancel the inertia torque ΔTe_inertia, it is necessary to increase / decrease the engine torque so that it has the same waveform as the inertia torque ΔTe_inertia and the direction of increase / decrease is in the opposite direction. Here, in order to take into account the engine torque delay, an engine torque increase / decrease command value whose phase has advanced by the engine torque delay phase from the inertia torque phase is calculated once, and the throttle valve opening command value is calculated from this engine torque increase / decrease command value. To ask. As a result, an increase or decrease in the engine torque generated with a delay in response to a command to increase or decrease the throttle valve opening accurately cancels the inertia torque.
[0046]
Assuming that a filter having a phase adjustment function and an approximate differentiation function is Gfil1 (s), the engine torque increase / decrease command value ΔTe_control is
(Equation 20)

It becomes. From Equations 19 and 20, the filter Gfil1 (s) is
(Equation 21)

It becomes. Here, the filter Gfil1 (s) processes the delay due to the transmission characteristic from the target speed ratio to the actual speed ratio, approximate differential processing, and shifts the phase of the engine torque increase / decrease command value by the amount of the engine torque generation delay from the phase of the inertia torque. This is a filter having a function of simultaneously performing the three processes of advancing.
[0047]
Therefore, when calculating the engine torque increase / decrease command value for canceling the inertia torque based on the target gear ratio Gt, the engine torque increase / decrease command value ΔtTe is calculated by the following equation using the filter Gfil1 (s) expressed by Expression 21. May be calculated.
(Equation 22)

[0048]
If Equation 21 can be realized without the M (s) by the property (the order of the numerator of the differential element s is equal to or less than the order of the denominator), the inertia torque can be calculated based on the speed ratio command value Gi. In that case, a filter having a phase adjustment function and an approximate differentiation function is provided.
(Equation 23)

And the engine torque increase / decrease ΔtTe is
[Equation 24]

Is calculated by
[0049]
In this way, the speed ratio command value Gi for limiting the time change of the speed ratio until reaching the target speed ratio Gt is set, and the speed ratio of the continuously variable transmission is controlled according to the speed ratio command value Gi. At the same time, the inertia torque at the time of the change of the gear ratio is calculated based on the gear ratio command value Gi. An engine torque increase / decrease command value for compensating for this inertia torque is calculated by applying a filter having a phase adjustment function and an approximate differentiation function to the speed ratio command value Gi, and the engine is operated according to the engine torque increase / decrease command value. Because it controls, even if there is a delay element in the drive system of the engine or the continuously variable transmission, the engine torque increase / decrease command value to cancel the inertia torque can be obtained accurately, and the inertia torque is compensated accurately. The speed ratio of the continuously variable transmission can be operated without reducing the driving performance.
[0050]
If the change in the transmission characteristics of the engine, the electronically controlled throttle, and the continuously variable transmission (from the target gear ratio Gt to the actual gear ratio G including the gear change control logic) due to the vehicle driving state cannot be ignored, all vehicles In order to optimize the phase between the inertia torque and the engine torque increase / decrease amount in the operating state, the parameters of the above formulas 17 to 24 are changed to the engine speed Ne, TP (intake air amount detection value) representing the load, vehicle speed VSP, speed change The configuration may be such that a parameter is switched according to the driving state of the vehicle by obtaining a preset table or map or numerical calculation based on the ratio G, the line pressure PL of the continuously variable transmission, the oil temperature To, and the like. The specific calculation method is the same as the calculation method of the above-described second embodiment, and a description thereof will be omitted.
[0051]
<< Fourth Embodiment of the Invention >>
The filters Gfil0 (s), Gfil1 (s), and Gfil2 (s) having the phase adjusting function and the approximate differentiating function used in the second and third embodiments are used to execute their calculations online. Since the order is high, the dimension is reduced by a known technique such as "realization of frequency-weighted balance", and a filter Gfil (s) as shown in the following equation is obtained.
(Equation 25)

Here, Tred is a time constant. Using this filter Gfil (s), the engine torque increase / decrease amount ΔtTe is calculated by:
(Equation 26)

Is calculated by
[0052]
Here, it is known that when approximated by Expression 25, the time constant Tred mainly depends on the engine speed Ne and the TP (intake air amount detection value) representing the load, and the relationship is as shown in FIG. become. Therefore, in order to optimize the phase between the inertia torque and the engine torque increase / decrease amount for compensating the inertia torque in all vehicle driving states, the time constant Tred is set to the engine speed Ne and the TP (intake air amount detection value) representing the load. ) May be referred to a preset table or map, and each parameter may be switched according to the vehicle driving state.
[0053]
As described above, the approximation differential filter is approximated to a low-order filter to calculate the amount of increase or decrease in engine torque, so that the load on the microcomputer that executes the calculation can be reduced and the calculation processing can be speeded up. Thus, the amount of increase or decrease in engine torque for compensating for inertia torque even with a rapid change in the gear ratio can be accurately obtained.
[0054]
<< Fifth Embodiment of the Invention >>
In the above-described fourth embodiment, when the time constant Tred shown in FIG. 21 mainly depends on the engine speed Ne and can be regarded as almost independent of the load, the time constant Tred is set as shown in FIG. A table value depending only on the engine speed Ne may be used. This makes it possible to reduce the load of the arithmetic processing by the microcomputer, and to accurately compensate for the inertia torque while increasing the speed of the arithmetic processing.
[0055]
In the above-described second to fifth embodiments, the filter having the function of simultaneously performing the three processes of the delay process due to the transmission characteristics of the continuously variable transmission, the approximate differential process, and the engine torque generation delay process is described. Although the engine torque increase / decrease command value is calculated using the method described above, the inertia torque is first calculated by the method described in the first embodiment, and the inertia torque is subjected to a filter for processing the engine torque generation delay. Alternatively, the engine torque increase / decrease command value may be calculated.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of an embodiment.
FIG. 2 is a diagram showing a structure of an engine.
FIG. 3 is a diagram showing a structure of a continuously variable transmission.
FIG. 4 is a control block diagram illustrating shift control of a control device.
FIG. 5 is a flowchart showing a target gear ratio calculation procedure.
FIG. 6 is a diagram showing a characteristic map of a continuously variable transmission input shaft rotation speed with respect to a vehicle speed and an accelerator pedal operation amount.
FIG. 7 is a diagram showing a characteristic map of an engine torque with respect to a throttle valve opening and an engine rotation speed.
FIG. 8 is a diagram showing measured values in which noise of a normal distribution with a variance of 0.01 is mixed when the gear ratio is changed from 1.0 to 2.0 in two seconds.
9 is a characteristic diagram in which a deviation (difference) for each sampling time with respect to the measurement value shown in FIG. 8 is approximately regarded as a gear ratio differential value (dG / dt).
FIG. 10 is a characteristic diagram in which a predetermined filter process is performed on the gear ratio measurement value on which the noise shown in FIG. 8 is superimposed.
11 is a characteristic diagram in which a deviation (difference) of the speed ratio after the filtering process illustrated in FIG. 10 for each sampling time is approximately regarded as a speed ratio differential value (dG / dt).
FIG. 12 is a characteristic diagram when the filter characteristic is changed from FIG.
FIG. 13 is a characteristic diagram when the filter characteristic is changed from that of FIG. 11;
FIG. 14 is a diagram showing a relationship between an engine speed Ne and an intake delay time constant TE of the engine.
FIG. 15 is a diagram showing a relationship between an engine speed Ne and a dead time TD of an engine torque.
FIG. 16 is a diagram showing a relationship between a line pressure, an oil temperature and a load of a continuously variable transmission and a parameter a.
FIG. 17 is a diagram showing a relationship between a line pressure, an oil temperature, and a load of a continuously variable transmission and a parameter b.
FIG. 18 is a diagram showing a relationship between a line pressure and an oil temperature of a continuously variable transmission and a parameter g.
FIG. 19 is a diagram showing a relationship between a line pressure and a load of a continuously variable transmission and a parameter g.
FIG. 20 is a diagram showing a relationship between a vehicle speed and a parameter f.
FIG. 21 is a diagram showing a relationship between an engine speed Ne and a load and a parameter Tred.
FIG. 22 is a diagram illustrating a relationship between an engine speed Ne and a parameter Tred.
[Explanation of symbols]
1 engine
2 Torque converter and forward / reverse switching mechanism
3 Continuously variable transmission
4 Final reducer and differential mechanism
5 drive wheels
6 Engine controller
7 Continuously variable transmission controller
8 Control device
8a Target gear ratio calculator
8b Gear ratio command value setting section
8c inerter torque calculation unit
8d Driving force compensation amount calculation unit
9 Accelerator sensor
10 Vehicle speed sensor
11 Wheel speed sensor
12 Engine rotation sensor

Claims (2)

A continuously variable transmission that continuously varies the output of the drive source;
Transmission control means for controlling a speed ratio of the continuously variable transmission according to a target speed ratio;
A drive source torque increase / decrease command value for compensating for inertia torque generated due to a change in equivalent inertia on the drive source side when the speed ratio of the continuously variable transmission is changed based on the target speed ratio. Drive source torque increase / decrease command value calculating means,
Output increase / decrease amount calculating means for calculating the output increase / decrease amount of the drive source based on the drive source torque increase / decrease command value,
A drive source control unit that controls the drive source according to the output increase / decrease amount,
The drive source torque increase / decrease command value calculation means includes a delay due to a transmission characteristic from the target speed ratio to an actual speed ratio of the continuously variable transmission, a torque generation delay of the drive source, and a delay of an electronically controlled throttle. A filter having a phase adjusting function for performing phase adjustment and an approximate differentiating function is approximated to a lower-order filter and applied to the target gear ratio to calculate the drive source torque increase / decrease command value. A control device for a vehicle equipped with a step transmission. A continuously variable transmission that continuously varies the output of the drive source;
Speed ratio command value setting means for setting a speed ratio command value for limiting a temporal change of the speed ratio until reaching the target speed ratio,
Transmission control means for controlling a speed ratio of the continuously variable transmission according to the speed ratio command value;
Based on the shift command value, a drive source torque increase / decrease command value for compensating for inertia torque generated due to a change in equivalent inertia on the drive source side when the speed ratio of the continuously variable transmission is changed is calculated. Drive source torque increase / decrease command value calculating means,
Output increase / decrease amount calculating means for calculating the output increase / decrease amount of the drive source based on the drive source torque increase / decrease command value,
A drive source control unit that controls the drive source according to the output increase / decrease amount,
The drive source torque increase / decrease command value calculation means includes a delay due to a transmission characteristic from the target speed ratio to an actual speed ratio of the continuously variable transmission, a torque generation delay of the drive source, and a delay of an electronically controlled throttle. A filter having a phase adjustment function for performing phase adjustment and an approximate differentiation function is applied to the speed ratio command value by approximating the filter to a lower-order filter, and the drive source torque increase / decrease command value is calculated. A control device for a vehicle equipped with a continuously variable transmission.

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