JP2009255628A - Damping device for vehicle - Google Patents

Abstract

Drive system vibration caused by torque fluctuation of an internal combustion engine in a vehicle is suppressed.
A vehicle vibration control device includes a plurality of vibration models having a plurality of degrees of freedom when a drive system including an engine 200, a motor generator 300, a drive shaft 11 and the like is simulated by a vibration model having a plurality of degrees of freedom. Drive from the estimated torque output from the engine 100 using the inverse function of the transfer function of the one-degree-of-freedom vibration model equivalent to the vibration model of multiple degrees of freedom in one of the natural vibration modes. A feedforward controller 110 that calculates a damping torque to be output from the motor generator 300 in order to suppress system vibration is provided.
[Selection] Figure 2

Description

  The present invention relates to a technical field of a vibration damping device for a vehicle for suppressing vibrations of the vehicle caused by fluctuations in torque output from an internal combustion engine such as an engine.

  This type of damping device is output from this internal combustion engine in order to suppress torsional vibration of the drive system due to torque fluctuations (ie, torque fluctuations or torque vibrations) output from the internal combustion engine to the drive system. There is known one that controls an electric motor so as to output a torque in a direction opposite to the torque (that is, a reverse torque) to a drive system (see, for example, Patent Documents 1 to 3).

  For example, Patent Document 1 discloses a technique for generating reverse torque in a motor so as to suppress periodic torque fluctuations that occur during engine operation. For example, Patent Document 2 discloses a technique for detecting a vibration state of a drive system and calculating an output torque of an electric motor for controlling the vibration of the drive system based on the detected vibration state. For example, Patent Document 3 discloses a technique for calculating torque to be output from a motor by subtracting the engine torque request value from a value obtained by processing the sum of the engine torque request value and the motor torque request value by a feedforward controller. Has been.

JP 2000-352332 A JP 2000-32607 A JP 2001-37006 A

  However, when the reverse torque output from the motor is determined by feedback control as in the technique disclosed in Patent Document 1, for example, the response to torque fluctuations in the high frequency region may not be sufficient. Here, in Patent Document 1, it is proposed that the reverse torque is determined by feedforward control in the high engine speed range, but the reverse torque is determined based on the assumption that the torque fluctuation is a constant cycle and a sine wave. Therefore, there is a technical problem that it is difficult to practically sufficiently suppress the vibration of the drive system. Further, for example, according to the technique disclosed in Patent Document 2, calculation to be performed by an ECU (Engine Control Unit) to calculate the output torque of the electric motor for controlling the vibration of the drive system becomes complicated, There is a technical problem that there is a possibility that a delay occurs in the control of the electric motor.

  The present invention has been made in view of, for example, the above-described problems, and provides a vehicle damping device that can suitably suppress vibration of a drive system caused by torque fluctuation of an internal combustion engine in a vehicle. Let it be an issue.

  In order to solve the above problems, a vehicle vibration damping device according to the present invention includes an internal combustion engine and an electric motor as driving force sources, and a drive system that transmits torque output from the internal combustion engine and the electric motor to driving wheels. A vibration control apparatus for a vehicle, wherein torque estimation means for estimating a torque output from the internal combustion engine to the drive system, and the internal combustion engine, the electric motor, and the drive system are simulated by a vibration model having a plurality of degrees of freedom. Using the inverse function of the transfer function of the one-degree-of-freedom vibration model equivalent to the vibration model of the plurality of degrees of freedom in one natural vibration mode among the plurality of natural vibration modes of the vibration model of the plurality of degrees of freedom. Calculating a damping torque to be output by the electric motor in order to suppress vibration of the drive system from the torque estimated by the torque estimating means, and outputting the vibration damping torque to the electric motor. And a feed-forward control means for controlling so.

  According to the vehicle vibration damping device of the present invention, during the operation, the torque output from the internal combustion engine to the drive system is estimated by the torque estimating means, and the vibration damping torque is calculated by the feedforward control means from the estimated torque. Calculated. The feedforward control means controls the electric motor so that the electric motor outputs the calculated damping torque.

  The torque estimation means estimates torque output from the internal combustion engine (that is, actual torque) based on, for example, operating conditions of the internal combustion engine. For example, the torque estimation means is an intake air amount (that is, an index value corresponding to the load of the internal combustion engine) detected or estimated by various detection means such as an air flow meter, or an actual load calculated from the intake air amount. Based on the ratio, engine speed, fuel injection amount, and fixed or variable value, such as a reference ignition timing, a corresponding numerical value from a map or the like stored in the appropriate storage means The torque output from the internal combustion engine is estimated by making a selection or performing a logical operation or numerical operation according to an appropriate algorithm or calculation formula each time.

  Particularly in the present invention, the feedforward control means includes a plurality of vibration models having a plurality of degrees of freedom when the internal combustion engine, the electric motor, and the drive system are simulated by a vibration model having a plurality of degrees of freedom (for example, a vibration model having two degrees of freedom). The vibration damping torque is calculated using the inverse function of the transfer function of the one-degree-of-freedom vibration model equivalent to the vibration model with multiple degrees of freedom in one of the natural vibration modes. That is, the feedforward control means is a feedforward controller configured as an inverse model of a single-degree-of-freedom vibration model equivalent to one natural mode in a vibration model of multiple degrees of freedom simulating an internal combustion engine, an electric motor, and a drive system. Is included. Thus, the vibration damping torque calculated by the feedforward control means is output from the electric motor to the drive system, so that the vibration of the drive system due to the fluctuation of the torque output from the internal combustion engine to the drive system (that is, the drive system Torsional vibration) can be suitably suppressed. Therefore, the vibration of the vehicle can be suppressed.

  In one aspect of the vehicle vibration damping device according to the present invention, the drive system is connected to the input shaft of the internal combustion engine and the electric motor and includes a lockup damper, and to the output shaft of the torque converter. The multi-degree-of-freedom vibration model includes the internal combustion engine and the electric motor as a first mass body, and the transmission as a second mass body. The torsional rigidity of the lockup damper is the first rigidity between the first mass body and the second mass body, and the torsional rigidity of the drive shaft is the second rigidity between the second mass body and the fixed end. This is a two-degree-of-freedom vibration model having a rigidity of 1.

  According to this aspect, for example, in the drive system due to fluctuations in torque output from the internal combustion engine to the drive system without complicating the calculation in the vibration damping device that can take the form of various processing units such as an ECU. Vibration can be effectively suppressed.

  The operation and other advantages of the present invention will become apparent from the best mode for carrying out the invention described below.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<First Embodiment>
The vibration damping device according to the first embodiment will be described with reference to FIGS.

  First, the configuration of a hybrid vehicle to which the vibration damping device according to the present embodiment is applied will be described with reference to FIG.

  FIG. 1 is a block diagram conceptually showing the structure of a hybrid vehicle to which the vibration damping device according to this embodiment is applied.

  In FIG. 1, the hybrid vehicle 1 includes an engine 200, a motor generator 300, a torque converter 400, a transmission 500, a differential gear 10, a drive shaft 11, wheels 12, and an ECU 100.

  The engine 200 is a gasoline engine as an example of the “internal combustion engine” according to the present invention, and functions as a main power source of the hybrid vehicle 1. An output shaft (that is, a crankshaft) of engine 200 is directly or indirectly connected to a pump impeller that is an input member of torque converter 400.

  The motor generator 300 functions as an electric motor that assists the power of the engine 200. Furthermore, the motor generator 300 also functions as a generator for charging a battery (not shown). The output member of motor generator 300 is directly or indirectly connected to the output member of engine 200. That is, the hybrid vehicle 1 is configured to be able to input power from the engine 200 and the motor generator 300 to the transmission 500 via the torque converter 400. It should be noted that the output member of engine 200 and the output member of motor generator 300 may be directly connected, or may be connected via a torque synthesis / distribution mechanism including a planetary gear mechanism, for example.

  The torque converter 400 is a so-called fluid power transmission device. Specifically, torque converter 400 includes a pump impeller coupled directly or indirectly to output members of engine 200 and motor generator 300, and a turbine runner coupled to an input shaft of transmission 500. It is configured to be able to transmit torque as power from the pump impeller side to the turbine runner side via oil while increasing the torque. Further, the torque converter 400 has a lockup mechanism that brings the input side and output side of the torque converter 400 into a directly connected state (that is, a lockup state). The torque converter 400 includes a lockup damper 410 as a part of the lockup mechanism. Lockup damper 410 includes a torsion spring provided between the input side and output side of torque converter 400. The lockup damper 410 has a function of reducing torsional vibration on the output side due to fluctuations in torque input to the torque converter 400.

  The transmission 500 is an automatic transmission having, for example, a planetary gear mechanism, and power is transmitted from the torque converter 400 via an input shaft. Specifically, in the transmission 500, a gear stage (shift stage) is set by engaging or releasing a clutch element, a brake element, a one-way clutch element, and the like, which are friction elements, in a predetermined state. Wheels 12 are connected to the output shaft of the transmission 500 via a differential gear 10 and a drive shaft 11. The torque converter 400, the transmission 500, the differential gear 10, and the drive shaft 11 constitute an example of the “drive system” according to the present invention, and transmit the output torque output from the engine 200 and the motor generator 300 to the wheels 12. .

  The ECU 100 is an electronic control unit that includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and is configured to be able to control the entire operation of the hybrid vehicle 1. 1 is an example of a “vehicle vibration damping device” according to the present invention. ECU 100 controls output torques of engine 200 and motor generator 300. The ECU 100 receives an accelerator opening signal corresponding to the depression angle of an accelerator pedal (not shown) by the driver from an accelerator opening sensor (not shown). ECU 100 controls the output torque of engine 200 according to the accelerator opening signal. ECU 100 is configured to be able to estimate an output torque actually output from engine 200 (that is, an actual torque output from engine 200) based on operating conditions of engine 200 such as a load factor and an engine speed. Yes. The ECU 100 has a feedforward controller 110 described later with reference to FIG. 2, and the damping torque calculated by the feedforward controller 110 based on the estimated value of the output torque output from the engine 200 is the motor. The motor generator 300 is controlled so as to be output from the generator 300.

  In the present embodiment, the hybrid vehicle 1 including the torque converter 400 and the transmission 500 is shown, but the present invention is not limited to application to such a hybrid vehicle 1. The present invention is also applicable to a vehicle equipped with a manual transmission (MT). Further, the present invention is not limited by the vehicle driving method, and the driving method of the hybrid vehicle 1 may be, for example, a front wheel driving (FF) method or a rear wheel driving (FR) method. May be.

  Next, control of the motor generator by the vibration damping device according to the present embodiment will be described with reference to FIGS.

  FIG. 2 is a block diagram for explaining the control of the motor generator by the vibration damping device according to the present embodiment. FIG. 3 is a diagram showing a model of the plant of the vibration damping device according to the present embodiment.

  In FIG. 2, a plant 900 which is a control target of the vibration damping device according to the present embodiment includes a torque converter 400, a transmission 500, a drive shaft 11 and the like from the engine 200 to the wheel 12 described above with reference to FIG. In this embodiment, the drive system is modeled as a two-degree-of-freedom vibration model shown in FIG.

  The feedforward controller 110 is configured as a part of the ECU 100 (see FIG. 1), and is an estimated engine torque value that is an estimated value of torque output from the engine 200.

に基づいてモータジェネレータ３００から出力すべき制振トルクを算出し、該算出した制振トルクを制振トルク指令値

The vibration damping torque to be output from the motor generator 300 is calculated based on the vibration damping torque, and the calculated vibration damping torque is used as the vibration damping torque command value.

としてモータジェネレータ３００に出力する。モータジェネレータ３００は、この制振トルク指令値に従ってトルクをプラント９００に対して出力する。

To the motor generator 300. The motor generator 300 outputs torque to the plant 900 in accordance with this damping torque command value.

  In FIG. 2, torque output from engine 200 to plant 900 (that is, actual torque output from engine 200) is shown as engine output torque Te, and output from motor generator 300 to plant 900 is shown. Torque (that is, actual torque output from the motor generator 300) is shown as motor output torque Tm.

  In FIG. 3, a plant 900 has an inertia moment m1 of the engine 200 and the motor generator 300, an inertia moment m2 of the transmission 500, a torsional rigidity k1 of the lockup damper 410, a viscosity damping coefficient c1 of the lockup damper 410, and a drive. As a two-degree-of-freedom vibration model in which the torsional rigidity of the drive system including the shaft 11 (in other words, the drive system closer to the wheel 12 than the transmission 500) is k2, and the viscous damping coefficient of the drive system including the drive shaft 11 is c2. Modeled.

  If the engine output torque Te is given as a forced force to the plant 900 modeled in this way, the equation of motion is expressed by the following equation (1).

この２自由度の振動モデルの固有値（即ち、固有角振動数）Ω_１、Ω_２は、下記の式（２）となる。

The natural values (that is, natural angular frequencies) Ω ₁ and Ω ₂ of the vibration model with two degrees of freedom are expressed by the following equation (2).

ここで、Ω_１＜Ω_２であり、ｄ＝ｋ_１ｋ_２、ｈ＝ｍ_１ｍ_２、ｇ＝ｍ_１ｋ_１＋ｍ_１ｋ_２＋ｍ_２ｋ_１とおいた。

Here, Ω ₁ <Ω ₂ and d = k ₁ k ₂ , h = m ₁ m ₂ , g = m ₁ k ₁ + m ₁ k ₂ + m ₂ k ₁ were set.

Considering the response that outputs the fluctuation of the torque of the drive system including the drive shaft 11 when the engine output torque Te is input to the inertia moment m1 (that is, the engine 200 and the motor generator 300) as a forced force, these two freedoms are considered. Transfer function of an equivalent one-degree-of-freedom vibration model (ie, a one-degree-of-freedom vibration model equivalent to the two-degree-of-freedom vibration model) for the eigenmode corresponding to the eigenvalue Ω _n (n = 1, 2) G _n (s) is represented by the following formula (3).

ここで、ｓは、ラプラス演算子（或いはラプラス変数）であり、ω_ｎ＝（Ｋ_ｎ／Ｍ_ｎ）^１／２、γ_ｎ＝Ｃ_ｎ／Ｍ_ｎとおいた。Ｍ_ｎは、ｎ次の（即ち、固有値Ω_ｎに対応する）モード質量であり、Ｋ_ｎは、ｎ次のモード剛性であり、Ｃ_ｎは、ｎ次のモード減衰係数である。

Here, s is a Laplace operator (or Laplace variable), and is set as ω _n = (K _n / M _n ) ^1/2 and γ _n = C _n / M _n . M _n is the n-th order mode mass (ie, corresponding to the eigenvalue Ω _n ), K _n is the n-th order mode stiffness, and C _n is the n-th order mode damping coefficient.

Particularly in the present embodiment, the feedforward control function F _n (s) of the feedforward controller 110 is an inverse function of the transfer function G _n (s) described above, as shown in the following equation (4). In order to improve the stability of the control, the second-order lag system is combined.

再び図２に戻り、フィードフォワード制御器１１０は、エンジントルク推定値

Returning to FIG. 2 again, the feedforward controller 110 determines the estimated engine torque value.

Based on the feedforward control function F _n (s), the damping torque to be output from the motor generator 300 is calculated, and the calculated damping torque is used as the damping torque command value.

としてモータジェネレータ３００に出力する。ここで本実施形態では特に、式（４）を参照して上述したように、フィードフォワード制御関数Ｆ_ｎ（ｓ）は、ドライブシャフト１１等からなる駆動系を図３を示した２自由度の振動モデルとしてモデル化した場合における、該２自由度の振動モデルの固有モードに対する等価１自由度振動モデルの伝達関数Ｇ_ｎ（ｓ）の逆関数に対して２次遅れ系を組み合わせたものとして構成されている。よって、フィードフォワード制御器１１０は、モータジェネレータ３００から出力されるトルクによってトルクコンバータ４００、トランスミッション５００、デファレンシャルギヤ１０及びドライブシャフト１１からなる駆動系の捩り振動を低減するように、モータジェネレータ３００を制御することができる。即ち、フィードフォワード制御器１１０を含む本実施形態に係る制振装置による制御によって、例えば、駆動系の捩り振動における共振点を少なくする或いは実践上無くすことができ、駆動系の捩り振動を低減することができる。

To the motor generator 300. Here, in the present embodiment, particularly, as described above with reference to the equation (4), the feedforward control function F _n (s) has a two-degree-of-freedom illustrated in FIG. In the case of modeling as a vibration model, the second delay system is combined with the inverse function of the transfer function G _n (s) of the equivalent one-degree-of-freedom vibration model for the natural mode of the two-degree-of-freedom vibration model. Has been. Therefore, the feedforward controller 110 controls the motor generator 300 so as to reduce the torsional vibration of the drive system including the torque converter 400, the transmission 500, the differential gear 10, and the drive shaft 11 by the torque output from the motor generator 300. can do. That is, by the control by the vibration damping device according to the present embodiment including the feedforward controller 110, for example, the resonance point in the torsional vibration of the drive system can be reduced or eliminated in practice, and the torsional vibration of the drive system is reduced. be able to.

FIG. 4 is a graph showing a comparison between the transfer characteristic of the plant after the control by the vibration damping device according to the present embodiment and the transfer characteristic in the two-degree-of-freedom vibration model shown in FIG. In the graph shown in FIG. 4, the transfer function G ₂ (s) of the equivalent one-degree-of-freedom vibration model corresponding to the second-order (that is, corresponding to the eigenvalue Ω ₂ ) and the transfer function G ₂ (s A feedforward control function F ₂ (s) in which a second-order lag system is combined with the inverse function of) is also shown. In FIG. 4, the result of the simulation performed in order to confirm the effect of the damping device which concerns on this embodiment is shown.

In FIG. 4, data L1 indicates the transfer characteristic of the plant 900 after the control by the vibration damping device according to the present embodiment, and the data L2 is in the vibration model with two degrees of freedom described above with reference to FIG. The transfer characteristic (in other words, the transfer characteristic of the drive system modeled by a vibration model with two degrees of freedom) is shown. The transfer function G ₂ (s) has a peak at a frequency that matches the secondary resonance frequency P2 in the transfer characteristics of the vibration model with two degrees of freedom indicated by the data L2. Since the feedforward control function F ₂ (s) is a combination of the inverse function of the transfer function G ₂ (s) and a second-order lag system, it is calculated based on the feedforward control function F ₂ (s). The transfer characteristic of the plant 900 after the control based on the vibration suppression torque command value has no resonance at the resonance frequency P2. Therefore, according to the control by the vibration damping device according to the present embodiment, the torsional vibration in the plant 900 (in other words, the drive system including the torque converter 400, the transmission 500, the differential gear 10, and the drive shaft 11) is effectively reduced. be able to. As a result, the vibration of the hybrid vehicle 1 can be reliably reduced.

  As described above, according to the vibration damping device according to the present embodiment, the drive system including the torque converter 400, the transmission 500, the differential gear 10, and the drive shaft 11 caused by the torque fluctuation of the engine 200 in the hybrid vehicle 1. Vibration can be suitably suppressed.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification. The apparatus is also included in the technical scope of the present invention.

1 is a block diagram conceptually showing the configuration of a hybrid vehicle to which a vibration damping device according to a first embodiment is applied. It is a block diagram for demonstrating control of the motor generator by the damping device which concerns on 1st Embodiment. It is a figure which models and shows the plant of the damping device concerning a 1st embodiment. It is a graph which shows the transfer characteristic of the plant after performing control by the damping device concerning a 1st embodiment, and the transfer characteristic in the vibration model of 2 degrees of freedom shown in Drawing 3.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 ... ECU, 200 ... Engine, 300 ... Motor generator, 400 ... Torque converter, 410 ... Lock-up damper, 500 ... Transmission, 10 ... Differential gear, 11 ... Drive shaft, 12 ... Wheel

Claims (2)

A vibration damping device for a vehicle including an internal combustion engine and an electric motor as a driving force source, and a drive system that transmits torque output from the internal combustion engine and the electric motor to driving wheels,
Torque estimation means for estimating torque output from the internal combustion engine to the drive system;
When the internal combustion engine, the electric motor, and the drive system are simulated by a vibration model having a plurality of degrees of freedom, the plurality of degrees of freedom in one natural vibration mode among a plurality of natural vibration modes of the vibration model having the plurality of degrees of freedom. Using the inverse function of the transfer function of the one-degree-of-freedom vibration model equivalent to the vibration model, the vibration control to be output by the electric motor to suppress the vibration of the drive system from the torque estimated by the torque estimating means Feed control means for calculating torque and controlling the electric motor to output the vibration damping torque. A vehicle vibration damping device comprising: The drive system includes: a torque converter including the internal combustion engine and the electric motor connected to an input shaft and including a lockup damper; a transmission connected to an output shaft of the torque converter; and a drive shaft connected to the transmission Including
The multi-degree-of-freedom vibration model includes the internal combustion engine and the electric motor as a first mass body, the transmission as a second mass body, and the torsional rigidity of the lockup damper as the first mass body and the first mass body. The vibration model is a two-degree-of-freedom model having a first stiffness between two mass bodies and a torsional stiffness of the drive shaft as a second stiffness between the second mass body and a fixed end. Item 4. The vehicle vibration damping device according to Item 1.

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