JP2009121426A - Damping control device for diesel engine vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the occurrence of unbalance of action effect between an increase side and a decrease side of variations in a fuel injection amount by damping control due to action of limit control of a smoke guard relative to the fuel injection amount in a damping control device executing damping of vibrations of a vehicle body by drive output control of a diesel vehicle. <P>SOLUTION: This drive control device includes a compensation component determining section calculating a compensation component compensating a wheel torque suppressing vibration amplitude of a vehicle body, and a control gain adjusting section adjusting the wheel torque input in the compensation component determining section or control gain of the compensation component output therefrom. The control gain is set small when the difference obtained by subtracting a basic fuel injection amount from the upper limit value of the fuel injection amount given to the driving device is small. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vibration damping control device for a vehicle such as an automobile, and more specifically, to control a vehicle driving output (driving force or driving torque) using a diesel engine as a driving device to suppress vibration of the vehicle body. The present invention relates to a vibration control device or a drive control device having such a vibration suppression control function.

Vehicle vibrations such as pitch and bounce while the vehicle is running are generated by braking / driving force (or inertial force) that acts on the vehicle body during acceleration / deceleration of the vehicle or other external force that acts on the vehicle body. This is reflected in the “wheel torque” (torque acting between the wheel and the grounded road surface) acting on the road surface (during driving). Therefore, in the field of vehicle vibration suppression control, it has been proposed to suppress the vibration of the vehicle body while the vehicle is running by adjusting the wheel torque through the drive output control of the vehicle engine or other drive device. (For example, see Patent Documents 1 and 2). In such vibration suppression control by drive output control, a vehicle acceleration / deceleration request is made using a motion model constructed assuming a so-called sprung vibration of a vehicle body or a dynamic model of sprung / unsprung vibration. Or external forces on the vehicle body (dynamic disturbances such as fluctuations in road reaction force and wind forces due to changes in road surface conditions such as unevenness or foreign matter on the road surface, changes in gradient or friction) The pitch bounce vibration generated in the vehicle body is predicted when the wheel torque fluctuates, and the drive output of the vehicle drive device is adjusted so that the predicted vibration is suppressed. In the case of this type of vibration suppression control, the generation of vibration energy is suppressed by adjusting the source of the force that generates vibration, rather than by absorbing vibration energy generated as in the case of vibration suppression control by the suspension. Therefore, the vibration damping action is relatively quick and the energy efficiency is good. Further, in the vibration damping control as described above, since the object to be controlled is concentrated on the wheel torque or the braking / driving force of the wheel, the control adjustment is relatively easy.
JP 2004-168148 A JP 2006-69472 A JP-A-11-223151 JP-A-2005-330861 JP 2006-152843 A

  When the vibration suppression control by the drive output control described above is executed, the output of the drive device is vibrated fluctuating so as to control the wheel torque so as to suppress the vehicle body vibration. In particular, when the vehicle drive device is a diesel engine, typically, the command value of the drive output (drive torque) for the engine is a required value or a target value of the fuel injection amount given to the engine. When the control is executed, the vehicle body is controlled with respect to the basic fuel injection amount (the fuel injection amount corresponding to the braking / driving request for the vehicle (including the fuel injection amount for maintaining the engine rotation when there is no braking / driving request)). For this reason, a fluctuation (compensation component) of the fuel injection amount that increases or decreases is given, and thereby the fuel injection amount is fluctuated in a vibrational manner. In this regard, in the control of the fuel injection amount of the diesel engine, the execution amount of the fuel injection amount may be limited so as not to exceed the upper limit for suppressing the occurrence of smoke. It has been found that only the change in the increasing direction among the fluctuations in the fuel injection amount due to the vibration suppression control reaches a peak, and this can cause the deterioration of the behavior of the vehicle.

  In a diesel engine, if the fuel injection amount exceeds a certain ratio with respect to the intake air amount (which is adjusted not only by the engine speed but also by EGR control and supercharger control), the ratio of incomplete combustion increases. In the exhaust, smoke is generated (for example, see Patent Document 3-5). Therefore, in the fuel injection amount control of the diesel engine, in short, the allowable fuel injection amount limit (smoke generation injection amount) with respect to the intake air amount is checked in advance, and the fuel injection exceeding the smoke generation injection amount is checked. The amount is forbidden to be given to the engine. Therefore, even when the total fuel injection amount requested value exceeds the smoke generation injection amount due to the vibrational change caused by the vibration suppression control, the fuel injection amount execution amount is limited to the smoke generation injection amount (the smoke guard is Need to be applied).

  However, if the required value of the fuel injection amount that is fluctuated by vibration suppression control as described above is limited by the upper limit value by the smoke guard, the displacement on the increase side (acceleration side) of the compensation component by vibration suppression control reaches a peak. On the other hand, a state in which the displacement on the reduction side (deceleration side) is reflected as it is as it is may occur (see the column of the embodiment described later and FIG. 7). As a result, in the vehicle body, the change in the direction of increasing the wheel torque (the effect of increasing the vehicle body nose) is suppressed, while the change in the direction of reducing the wheel torque (lowering the vehicle body nose). Direction) effectively acts, and this can cause the pitch moment acting on the vehicle body to become unbalanced and the behavior of the vehicle body to deteriorate. In an extreme case, a state where the nose of the vehicle body is lowered and remains unnatural can be caused by executing the vibration suppression control.

  Thus, a main subject of the present invention is a vibration suppression control device for executing vibration suppression control by drive output control in a diesel engine vehicle, which is for restricting control such as smoke guard for the fuel injection amount of the diesel engine. An object of the present invention is to provide a vibration suppression control device configured so that an imbalance of the operation effect does not occur between the increase side and the decrease side of the fluctuation of the fuel injection amount due to the vibration suppression control caused by the operation.

  According to the present invention, in a diesel engine vehicle, a vibration suppression control device that suppresses body vibration such as pitch bounce by driving output control, wherein the fuel injection amount is an upper limit set for the purpose of preventing the occurrence of smoke, etc. In a configuration in which exceeding the value is prohibited, the wheel torque input to the vibration damping control device or calculated to avoid the peak of fluctuation of the compensation component in the fuel injection amount or to be minimized. As a result, the control gain of the compensation component is adjusted, and thereby, the control effect configured so that the imbalance of the operation effect does not occur between the increase side and the decrease side of the fluctuation of the driving torque (that is, fluctuation of the fuel injection amount). A vibration control device is provided.

  A vehicle vibration suppression control device for controlling vehicle drive output by using a diesel engine of the present invention as a drive device to suppress vehicle body vibration is provided at a ground contact point between the vehicle wheel and a road surface. A compensation component determining unit that calculates a compensation component for compensating the wheel torque so as to suppress the amplitude of the vehicle body vibration based on the wheel torque acting on the generated wheel is included. That is, the vibration suppression control device of the present invention basically has a vehicle body vibration (typical) that can be generated by a driver or a braking / driving request (or a turning request) by automatic driving control or a disturbance acting on the vehicle body while the vehicle is running. Specifically, it is a vibration damping control device of a type that compensates the drive output (drive torque) of the drive device so as to reduce or cancel the pitch bounce vibration). In such a vibration suppression control device, typically, the compensation component calculated by the compensation component determination unit is superimposed on the required value of the driving torque to be given to the engine, and thereby the required value of the driving torque is superimposed. The component that causes the vehicle body vibration included is reduced or removed, or the driving torque is controlled in a direction that cancels the action of the component (vibration force) that causes the vehicle body vibration in the disturbance acting on the vehicle body. .

  However, in the diesel engine, as already described, the total fuel injection amount (that is, the fuel injection amount obtained by superimposing the compensation component on the basic fuel injection amount) is set to be equal to or lower than the upper limit value set for the purpose of preventing the occurrence of smoke. It is necessary to suppress. Therefore, preferably, the vibration suppression control apparatus is configured such that the fluctuation of the fuel injection amount given by the compensation component is the upper limit value of the fuel injection amount given to the vehicle drive device (diesel engine) in the increasing direction. The basic fuel injection amount given to the drive device is subtracted from the width and is limited to a width corresponding to the difference obtained. However, on the other hand, due to the restriction on the increase direction of the fluctuation of the fuel injection amount due to the compensation component, this time, as described above, the effect of the operation is increased between the increase side and the reduction side of the fluctuation of the fuel injection amount due to the vibration suppression control. Imbalance can occur.

  Therefore, the vibration suppression control device of the present invention further adjusts the control gain (input gain) of the wheel torque input to the compensation component determination unit or the control gain (output gain) of the compensation component output from the compensation component determination unit. A control gain adjusting unit that performs control gain (input gain or output gain) when the difference obtained by subtracting the basic fuel injection amount from the upper limit value of the fuel injection amount is small. It is configured to be set smaller than when the value is large. Here, the “difference” is, in other words, the width of the range in which the variation in the fuel injection amount in the increasing direction from the basic fuel injection amount to the upper limit value of the fuel injection amount planned is allowed. This corresponds to the margin on the increase side. Further, when the control gain is set to be small, the amplitudes on both the increase side and the decrease side of the compensation component superimposed on the basic fuel injection amount become small. Therefore, according to the above-described configuration of the present invention, when the margin on the increase side of the fuel injection amount is small, the control gain is set to be relatively smaller than that when the margin is large, thereby compensating for the compensation. The vibration displacement on both the increase side and the decrease side of the component is reduced, and the possibility that the increase side fluctuation due to the total fuel injection amount or the compensation component therefor is limited will be reduced, and the control will be suppressed. It is possible to reduce the possibility that an imbalance of the effect of the vibration suppression control occurs between the increase side and the decrease side of the fluctuation of the fuel injection amount required by the vibration control.

  In the control gain adjusting unit, the control gain may be reduced when the difference between the fuel injection amount limit value and the basic fuel injection amount is smaller than a predetermined value. The smaller the difference between the fuel injection amount limit value and the basic fuel injection amount, the smaller the control gain may be. That is, it is possible to adjust the degree of reduction of the amplitude of the compensation component in accordance with the changeable width in the increasing direction of the fuel injection amount so that the effect of the vibration suppression control can be maintained as much as possible. Further, when the difference between the limit value of the fuel injection amount and the basic fuel injection amount is 0 or less (when the basic fuel injection amount exceeds the limit value), the vibration suppression is no longer performed with respect to the basic fuel injection amount. The control gain may be set to 0 because the increase side fluctuation for control cannot be added.

  By the way, as described above, in the vibration suppression control device based on the drive output control, the vibration component that causes the vehicle body vibration included in the wheel torque fluctuation that occurs when the vehicle acceleration / deceleration request or the braking / driving request is made is suppressed. And a compensation component (feedback compensation component) that suppresses a vibration component that causes a vehicle body vibration included in a wheel torque fluctuation caused by a disturbance acting on the vehicle body. It's okay. Of these compensation components, the feedforward compensation component is a component in a direction that reduces fluctuations in the required value of the drive torque corresponding to the acceleration / deceleration request or braking / driving request of the vehicle. When the vehicle is decelerating, the basic fuel injection amount is reduced when the vehicle is decelerating, so the total fuel injection amount is limited by compensation using the feedforward compensation component. Exceeding the value hardly occurs. On the other hand, the feedback compensation component is generated so as to counter the disturbance that becomes the excitation force, so that the fuel injection amount can be increased or decreased regardless of the acceleration / deceleration of the vehicle. Therefore, the adjustment of the control gain as described above may be performed only on the control gain for the feedback compensation component.

  In addition, as described above, the feedforward compensation component acts in a direction to reduce the fuel injection amount when the vehicle is accelerated. When the feedforward compensation component is displaced in the reduction direction in this way, the fuel injection is performed by the reduction amount. The variable width in the increasing direction of the amount will increase. By assigning such an increase in the variable range to the variable range of the feedback compensation component, it is possible to increase the amplitude of the feedback compensation component and increase the operational effect of the vibration suppression control. Therefore, as another aspect of the vibration suppression control apparatus of the present invention, the compensation component determining unit compensates the wheel torque for suppressing the vehicle body vibration amplitude generated by the wheel torque that is actually generated in the wheel. And a feedforward compensation component that compensates for the wheel torque that suppresses the vehicle body vibration amplitude generated by the wheel torque generated by the acceleration / deceleration request to the vehicle, and the fuel injection amount given by the feedback compensation component increases in the increasing direction. Further, it may be allowed to vary within a range corresponding to a value obtained by further subtracting the feedforward compensation component from the difference between the limit value of the fuel injection amount and the basic fuel injection amount. In this case, the control gain is a value obtained by further subtracting the feedforward compensation component from the difference between the upper limit value of the fuel injection amount and the basic fuel injection amount (in other words, adding the absolute value of the feedforward compensation component). It may be determined based on a width corresponding to. That is, when the value obtained by further subtracting the feedforward compensation component from the difference between the upper limit value of the fuel injection amount and the basic fuel injection amount is small, the control gain is set to be smaller than when the value is large. It may be.

  In the series of aspects described above, the upper limit value of the fuel injection amount may typically be the smoke generation injection amount. The smoke generation injection amount may be experimentally or theoretically determined in advance as a function of the intake air amount.

  In general, according to the present invention, when the vibration suppression control by the drive output control is executed in the diesel engine vehicle, the increase in the fuel injection amount is limited for the purpose of avoiding the occurrence of smoke, etc. By adjusting the increase / decrease amplitude of the compensation component with reference to the margin from the injection amount to the upper limit value of the fuel injection amount, the possibility of the compensation component reaching the peak is reduced, and the compensation component is increased and decreased. Therefore, the possibility of unbalance of the vibration damping effect is reduced. And this is expected to prevent the occurrence of smoke during execution of vibration suppression control, and to prevent instability of vehicle behavior due to the vibration suppression control being executed halfway, The practicality of damping control will be improved.

  In the above aspect, the fuel injection amount given by the feedback compensation component further subtracts the feedforward compensation component from the difference between the limit value of the fuel injection amount and the basic fuel injection amount in the increasing direction. With respect to a configuration that allows variation within a range corresponding to the obtained value, this configuration also reduces the possibility of a fluctuation on the increase side of the feedback compensation component. Therefore, it should be understood that this aspect may be realized with or without the control gain adjustment control.

  Other objects and advantages of the present invention will become apparent from the following description of preferred embodiments of the present invention.

  The present invention will now be described in detail with reference to a few preferred embodiments with reference to the accompanying drawings. In the figure, the same reference numerals indicate the same parts.

Diagram 1 of the apparatus is a vehicle such as an automobile in which the preferred embodiment of the vibration damping control device is mounted of the present invention is schematically shown. In the figure, the vehicle 10 having the left and right front wheels 12FL and 12FR and the left and right rear wheels 12RL and 12RR is driven in the normal manner according to the depression of the accelerator pedal 14 by the driver. A drive device 20 that generates torque is mounted. In the illustrated example, the driving device 20 is configured such that driving torque or rotational driving force is transmitted from the engine 22 to the rear wheels 12RL and 12RR via the torque converter 24, the automatic transmission 26, the differential gear device 28, and the like. Composed. The engine 22 is a well-known diesel engine, and each cylinder of the engine is operated such that the operation of the fuel device 22a achieves a driving torque request determined according to the amount of depression of the accelerator pedal and a control amount described below. The fuel injection amount from the fuel injection device 22b and / or other parameters (injection timing, injection rate (fuel injection amount per unit time), injection pressure, etc., hereinafter collectively referred to as “fuel injection control amount”). Controlled to adjust. Although not shown for the sake of simplicity, the vehicle 10 is provided with a braking device that generates a braking force on each wheel and a steering device for controlling the steering angle of the front wheels or the front and rear wheels, as in a normal vehicle. . The vehicle may be a four-wheel drive vehicle or a front wheel drive vehicle. Further, although not shown, an EGR device and a supercharger may be provided in association with the diesel engine in order to adjust the intake air amount.

  A control parameter of the drive output of the engine 22 (basically, a fuel injection control amount including a fuel injection amount to each cylinder) is adjusted by a command from the electronic control unit 50. The electronic control unit 50 may include a microcomputer having a CPU, a ROM, a RAM, and an input / output port device, which are connected to each other by a bidirectional common bus, and a driving circuit. The electronic control device 50 includes a signal representing a wheel speed Vwi (i = FL, FR, RL, RR) from a wheel speed sensor 30i (i = FL, FR, RL, RR) mounted on each wheel, a vehicle The engine rotational speed ne from the sensors provided in each part of the engine, the accelerator pedal depression amount θa, the engine coolant temperature (not shown), the engine lubricating oil temperature (not shown), the transmission output rotational speed no, the lubrication Signals such as oil temperature (not shown) and the driver's shift lever position are input. In addition to the above, it should be understood that various detection signals for obtaining various parameters necessary for various controls to be executed in the vehicle of the present embodiment may be input.

  FIG. 2 shows the internal configuration of the electronic control unit 50 in the form of control blocks. Referring to the figure, an electronic control unit 50 includes a drive control unit 50a that controls the operation of the engine, a braking control unit 50b that controls the operation of a braking unit (not shown), and a known diesel engine. You may comprise from the various control apparatuses (not shown) with which the electronic control apparatus of an engine vehicle is equipped. It should be understood that the configuration and operation of various control devices such as the drive control device are realized by processing operations of a microcomputer or the like in the electronic control device 50 during operation of the vehicle.

  As shown in the drawing, the braking control device 50b receives electric signals in a pulse format that are sequentially generated every time the wheels rotate by a predetermined amount from the wheel speed sensors 30FR, FL, RR, RL of each wheel, The rotational speed of the wheel is calculated by measuring the time interval at which such sequentially input pulse signals arrive, and the wheel speed value r · ω is calculated by multiplying this by the wheel radius. Then, the wheel speed value r · ω is transmitted to the drive control device 50a and used for calculation of the estimated wheel torque value in order to execute vibration suppression control which will be described in detail later. The calculation from the wheel rotation speed to the wheel speed may be performed by the drive control device 50a. In this case, the wheel rotation speed is given from the braking control device 50b to the drive control device 50a. Further, the vehicle speed may be determined in any known manner from the wheel speed calculated in the braking control device 50b.

  As a basic configuration, the drive control device 50a has a required value of the engine drive torque requested by the driver based on the accelerator pedal depression amount θa from the accelerator pedal sensor (in the case of a diesel engine, the drive torque is set to the fuel injection amount). Therefore, the required fuel injection amount is adopted as the required value.) A drive torque required value determining unit 51 that determines the required value and a drive for executing the vehicle body pitch / bounce vibration damping control by the drive torque control. A compensation component determination unit 52 that calculates a compensation component that compensates (corrects) the torque request value, and a driver of each part of the engine or fuel device that achieves the request value based on the drive torque request value compensated by the compensation component ( And a fuel injection control command determination unit 53 for determining a control command (not shown).

  In such a basic configuration, the drive torque request value determination unit 51 determines the required fuel injection amount from the accelerator pedal depression amount θa or the request of the automatic travel control device (not shown) by any known method. It may be. The output from the drive torque request value determining unit 51 is a basic fuel injection amount, that is, a fuel injection amount for achieving a braking / driving request for the vehicle and for maintaining engine rotation.

As shown in the figure, the compensation component determination unit 52 converts a drive torque request value (before compensation) determined based on the accelerator pedal depression amount θa and the like into a wheel torque (wheel torque request value), and a wheel torque estimator. In 52c, the estimated value of the wheel torque actually acting on the wheel estimated from the wheel speed r · ω is received, and the wheel torque request value and the estimated value are determined in the manner described in detail later. A compensation component that reduces or cancels a vibration component that can cause pitch bounce vibration in the vehicle body is calculated. In the compensation component determining unit 52, an FF compensation component determining unit 52a that calculates a compensation component (feed forward (FF) compensation component U _FF ) for the drive torque request value (before compensation), and the wheel currently generated An FB compensation component determination unit 52b for calculating a compensation component for torque (feedback (FB) compensation component U _FB ) may be provided, and the compensation components U _FF and U _FB may be calculated separately. Alternatively, one compensation component U may be calculated by integrating the FF compensation component determination unit 52a and the FB compensation component determination unit 52b. Since the vibration characteristics (frequency, amplitude, vibration direction) of the FF compensation component and the FB compensation component are different from each other, the calculation of the control gain can be performed separately as will be described in detail later by enabling the calculation separately. It is possible to set limits on the adjustment and compensation components. On the other hand, when both compensation components are calculated at once, the arithmetic processing is simplified. Further, the compensation component determining unit may further calculate a compensation component for damping pitch / bounce vibration caused by a change in wheel torque generated in the wheel by a driver's braking operation or steering operation. . In this case, as indicated by the dotted line in the figure, the estimated value of the wheel torque estimated based on the brake operation amount or the steering operation amount by the wheel torque estimator 52x is used as the compensation component determination unit (FF compensation component determination unit). Or the FB compensation component determination unit) and the same processing as the above-described wheel torque request value or estimated value is performed to calculate the compensation component. The estimation of the change amount of the wheel torque based on the brake operation amount or the steering operation amount may be performed by any known method.

  Thus, the compensation component calculated by the compensation component determination unit 52 is converted into a unit of fuel injection amount and transmitted to the adder a1, and the compensation component is added to the drive torque request value (before compensation) in the adder a1. Is superimposed, the required drive torque value, that is, the required fuel injection amount (basic fuel injection amount) is compensated. The required fuel injection amount after compensation is determined in advance by referring to the required fuel injection amount (after compensation) and the engine speed and / or engine temperature at that time in the fuel injection control command determination unit 53. Using a map determined experimentally or theoretically, in a known manner, a driver (not shown) of each part of the engine or fuel system is achieved so as to achieve the required fuel injection amount (after compensation). The control command is determined and transmitted to each driver.

  Further, in the present embodiment, in addition to the basic configuration described above, the compensation component calculated by the compensation component determination unit 52 is added to the basic fuel injection amount by the adder a1 before being superimposed on the compensation component. A compensation injection amount limiter 52e for limiting the value of is provided. In the limiting process, the value of the total fuel injection amount when the compensation component is superimposed on the basic fuel injection amount is the smoke generation injection amount, that is, the fuel injection supplied to the engine for avoiding the generation of smoke. The vibration displacement of the compensation component is limited within a fluctuation range determined in a later-described manner by the smoke generation injection amount and the basic fuel injection amount so as not to exceed the upper limit value of the execution amount of the amount (the compensation component The limiting process for vibration displacement is hereinafter referred to as “upper limit guard process”. However, when the upper limit guard process is executed, as described in the “Disclosure of the Invention” section, the displacement on the increase side of the compensation component reaches a peak, and thereby, the increase and decrease sides of the compensation component are controlled. An imbalance of the effect of vibration control occurs. Therefore, a control gain adjuster 52f for adjusting the control gains 52d and 52g on the input or output side of the compensation component determination unit is provided so as to reduce the unbalance of the operational effects. The details of the control gain adjuster 52e and the compensation injection amount limiter 52f will be described later.

  In the present embodiment, the wheel torque is controlled by controlling the driving torque transmitted from the driving device to the wheel, but at the same time, it is also achieved by appropriately operating the braking device or the steering device. It should be understood that it may be.

Device Operation (i) Pitch / Bounce Vibration Suppression Control In the above configuration, the pitch / bounce vibration suppression control by the compensation component calculated by the compensation component determination unit 52 in FIG. 2 is performed in the following manner. You may be broken.

(Principle of vibration suppression control)
In the vehicle, when the driving device is activated based on the driving request of the driver and the wheel torque fluctuates, the vertical position of the center of gravity Cg of the vehicle body in the vehicle body 10 as illustrated in FIG. The bounce vibration in the direction (z direction) and the pitch vibration in the pitch direction (θ direction) around the center of gravity of the vehicle body can occur. In addition, if a force or torque (disturbance) acts on wheels due to changes in road surface conditions or wind while the vehicle is running, the disturbance is transmitted to the vehicle, and vibrations in the bounce direction and pitch direction are also generated in the vehicle body. obtain. Therefore, in the pitch / bounce vibration damping control exemplified here, a motion model of the pitch / bounce vibration of the vehicle body is constructed, and in the model, a value obtained by converting the drive torque request value to the wheel torque and / or When the current estimated wheel torque value is inputted, the displacement z and θ of the vehicle body and the rate of change dz / dt and dθ / dt, that is, the state variable of the vehicle body vibration is calculated, and the state variable obtained from the model becomes 0. The drive torque of the drive device (engine) is adjusted so as to converge, that is, the pitch / bounce vibration is suppressed (the drive torque request value is corrected).

ここに於いて、Ｌｆ、Ｌｒは、それぞれ、重心から前輪軸及び後輪軸までの距離であり、ｒは、車輪半径であり、ｈは、重心の路面からの高さである。なお、式（１ａ）に於いて、第１、２項は、前輪軸から、第３、４項は、後輪軸からの力の成分であり、式（１ｂ）に於いて、第１項は、前輪軸から、第２項は、後輪軸からの力のモーメント成分である。式（１ｂ）に於ける第３項は、駆動輪に於いて発生する車輪トルクＴが車体の重心周りに与える力のモーメント成分である。 Thus, first, as a dynamic motion model in the bounce direction and the pitch direction of the vehicle body in the vibration suppression control, for example, as shown in FIG. 3B, the vehicle body is a rigid body S having a mass M and an inertia moment I. It is assumed that the rigid body S is supported by a front wheel suspension having an elastic modulus kf and a damping rate cf, and a rear wheel suspension having an elastic modulus kr and a damping rate cr (vehicle body sprung vibration model). In this case, the motion equation in the bounce direction and the motion equation in the pitch direction of the center of gravity of the vehicle body are expressed as the following Equation 1.

Here, Lf and Lr are distances from the center of gravity to the front wheel shaft and the rear wheel shaft, respectively, r is a wheel radius, and h is a height of the center of gravity from the road surface. In the equation (1a), the first and second terms are components of the force from the front wheel shaft, the third and fourth terms are components of the force from the rear wheel shaft, and in the equation (1b), the first term is From the front wheel shaft, the second term is the moment component of the force from the rear wheel shaft. The third term in the equation (1b) is a moment component of the force that the wheel torque T generated in the drive wheel gives to the periphery of the center of gravity of the vehicle body.

であり、行列Ａの各要素a1-a4及びb1-b4は、それぞれ、式（１ａ）、（１ｂ）のｚ、θ、ｄｚ／ｄｔ、ｄθ／ｄｔの係数をまとめることにより与えられ、
a1=-(kf+kr)/M、a2=-(cf+cr)/M、
a3=-(kf・Lf-kr・Lr)/M、a4=-(cf・Lf-cr・Lr)/M、
b1=-(Lf・kf-Lr・kr)/I、b2=-(Lf・cf-Lr・cr)/I、
b3=-(Lf²・kf+Lr²・kr)/I、b4=-(Lf²・cf+Lr²・cr)/I
である。また、ｕ(t)は、
ｕ(t)＝Ｔ
であり、状態方程式（２ａ）にて表されるシステムの入力である。従って、式（１ｂ）より、行列Ｂの要素p1は、
p1=h/(I・r)
である。 The above formulas (1a) and (1b) are expressed as (linear) as shown in the following formula (2a) with the vehicle body displacements z and θ and their change rates dz / dt and dθ / dt as the state variable vector X (t). It can be rewritten in the form of a system state equation.
dX (t) / dt = A · X (t) + B · u (t) (2a)
Here, X (t), A, and B are respectively

And each element a1-a4 and b1-b4 of the matrix A is given by combining the coefficients of z, θ, dz / dt, dθ / dt in the equations (1a) and (1b), respectively.
a1 =-(kf + kr) / M, a2 =-(cf + cr) / M,
a3 =-(kf ・ Lf-kr ・ Lr) / M, a4 =-(cf ・ Lf-cr ・ Lr) / M,
b1 =-(Lf ・ kf-Lr ・ kr) / I, b2 =-(Lf ・ cf-Lr ・ cr) / I,
b3 =-(Lf ²・ kf + Lr ²・ kr) / I, b4 =-(Lf ²・ cf + Lr ²・ cr) / I
It is. U (t) is
u (t) = T
And is an input of the system represented by the state equation (2a). Therefore, from equation (1b), the element p1 of the matrix B is
p1 = h / (I ・ r)
It is.

In the equation of state (2a)
u (t) = − K · X (t) (2b)
Then, the equation of state (2a) is
dX (t) / dt = (A-BK) .X (t) (2c)
It becomes. Accordingly, the initial value X ₀ (t) of X (t) is set as X ₀ (t) = (0,0,0,0) (assuming that there is no vibration before torque is input). ), The gain that converges the magnitude of X (t), that is, the displacement in the bounce direction and the pitch direction and its time change rate, to 0 when the differential equation (2c) of the state variable vector X (t) is solved When K is determined, a torque value u (t) for suppressing pitch bounce vibration is determined. A value obtained by converting the torque value u (t) into the engine drive torque request value (in this embodiment, the fuel injection amount) is a compensation component given to the engine by the vibration suppression control.

The gain K can be determined by using a so-called optimal regulator theory. According to this theory, a quadratic evaluation function J = 1/2 · ∫ (X ^T QX + u ^T Ru) dt (3a)
(Integral range is 0 to ∞)
When the value of is the minimum, the matrix K that minimizes the evaluation function J by the stable convergence of X (t) in the state equation (2a) is
K = R ⁻¹・ B ^T・ P
It is known to be given by Where P is the Riccati equation
^{-dP / dt = A T P +} PA + Q-PBR -1 B T P
Is the solution. The Riccati equation can be solved by any method known in the field of linear systems, which determines the gain K.

などと置いて、式（３ａ）に於いて、状態ベクトルの成分のうち、特定のもの、例えば、ｄｚ／ｄｔ、ｄθ／ｄｔ、のノルム（大きさ）をその他の成分、例えば、ｚ、θ、のノルムより大きく設定すると、ノルムを大きく設定された成分が相対的に、より安定的に収束されることとなる。また、Ｑの成分の値を大きくすると、過渡特性重視、即ち、状態ベクトルの値が速やかに安定値に収束し、Ｒの値を大きくすると、消費エネルギーが低減される。 Q and R in the evaluation function J and Riccati equation are a semi-positive definite symmetric matrix and a positive definite symmetric matrix, respectively, which are arbitrarily set, and are weight matrices of the evaluation function J determined by the system designer. For example, in the case of the motion model considered here, Q and R are

In Equation (3a), a specific one of the components of the state vector, for example, the norm (magnitude) of dz / dt, dθ / dt, and the other components, for example, z, θ If the value is set larger than the norm of, the component having the larger norm is converged relatively stably. Further, when the value of the Q component is increased, the transient characteristics are emphasized, that is, the value of the state vector quickly converges to a stable value, and when the value of R is increased, the energy consumption is reduced.

ここに於いて、xf、xrは、前輪、後輪のばね下変位量であり、mf、mrは、前輪、後輪のばね下の質量である。式（４ａ）−（４ｂ）は、ｚ、θ、xf、xrとその時間微分値を状態変数ベクトルとして、図３（Ｂ）の場合と同様に、式（２ａ）の如き状態方程式を構成し（ただし、行列Ａは、８行８列、行列Ｂは、８行１列となる。）、最適レギュレータの理論に従って、状態変数ベクトルの大きさを０に収束させるゲイン行列Ｋを決定することができる。 As a dynamic motion model in the bounce direction and the pitch direction of the vehicle body, for example, as shown in FIG. 3C, in addition to the configuration in FIG. 3B, the spring elasticity of the front and rear tires A model that takes into account the above (vehicle body sprung / lower vibration model) may be employed. Assuming that the front and rear tires have the respective elastic moduli ktf and ktr, the motion equation in the bounce direction and the motion equation in the pitch direction of the center of gravity of the vehicle body are as understood from FIG. The following equation 4 is expressed.

Here, xf and xr are unsprung displacement amounts of the front and rear wheels, and mf and mr are unsprung masses of the front and rear wheels. Equations (4a)-(4b) form a state equation as shown in Equation (2a) using z, θ, xf, xr and their time differential values as state variable vectors, as in FIG. 3B. (However, the matrix A has 8 rows and 8 columns and the matrix B has 8 rows and 1 column.) According to the theory of the optimal regulator, the gain matrix K that converges the magnitude of the state variable vector to 0 can be determined. it can.

(Configuration of compensation component determination unit)
The configuration of the control process in the compensation component determination unit 52 in FIG. 2 for calculating the compensation component U for the pitch / bounce vibration suppression control is shown in the form of a control block in FIG. ing. In the compensation component determining unit 52, as illustrated in FIG. 2, when the FF compensation component determining unit 52a and the FB compensation component determining unit 52b are provided separately, the FF compensation component determining unit, FB Each of the compensation component determination units may be configured as shown in FIG. 3D so that the FF compensation component U _FF and the FB compensation component U _FB are output separately. In addition, when one compensation component U (= U _FF + U _FB ) is calculated for the FF compensation component and the FB compensation component collectively, the configuration shown in FIG. One is provided.

In the control configuration of FIG. 3D, first, a value Two (FF compensation component determination unit) obtained by converting the drive torque request value from the drive torque request determination unit 51 into the wheel torque to the wheel torque input end of the motion model. ) Or wheel torque currently being generated at the wheel (estimated value thereof) Tw (in the case of the FB compensation component determination unit), respectively. Note that the estimated wheel torque value corresponding to the brake operation amount or the steering operation amount may be input to the FF compensation component determination unit or the FB compensation component determination unit together with the drive torque request value. It may be determined appropriately depending on the vibration characteristics of the torque value to be applied.) In addition, when calculating the FF compensation component and the FB compensation component in a lump, the value Two obtained by converting the drive torque request value into the wheel torque at the wheel torque input end of the control block and the actual value at the wheel. Wheel wheel torque (estimated value) Tw is added. Next, in the motion model, the state variable vector X (t) is calculated by solving the differential equation (2a) using the torque input value T (= Two, = Tw or = Two + Tw). The Then, a value u (t) obtained by multiplying the state vector X (t) by the gain “−K” determined to converge the state variable vector X (t) to 0 or the minimum value as described above is calculated. The u (t) is converted into a compensation component U _FF or U _FB or U in units of engine drive torque request values. The compensation component thus calculated is transmitted to the adder a1 via the injection amount limiter 52e, and is superposed on the drive torque request value in the adder a1, thereby obtaining the value of K · X (t). The corresponding component is subtracted from the drive torque request value. The body pitch / bounce vibration system is a resonance system as understood from equations (1a) and (1b), and the value of the state variable vector X (t) is substantially equal to an arbitrary input. Only the frequency components in a band having a certain spectral characteristic centered around the natural frequency (about 1 to 5 Hz) of the system. Accordingly, by subtracting K · X (t) from the drive torque request value as described above, the natural frequency component of the system of the drive torque request value or the currently generated wheel torque, that is, in the vehicle body. Thus, components that cause pitch bounce vibration are reduced or eliminated, and pitch bounce vibration in the vehicle body is suppressed.

(Estimation of wheel torque)
For the motion model shown in FIG. 3D, the wheel torque value Tw that is actually generated, which is input as a disturbance effect, is ideally detected by providing a torque sensor for each wheel. However, it is difficult to provide a torque sensor on each wheel of a normal vehicle. Therefore, in the illustrated example, the wheel torque estimated value estimated by the wheel torque estimator 52c (FIG. 2) from other detectable values in the running vehicle is used as the disturbance input of the wheel torque. The wheel torque estimated value Tw is typically obtained by using a wheel rotational speed ω obtained from a wheel speed sensor of a driving wheel or a time derivative of a wheel speed value r · ω,
Tw = M · r ² · dω / dt (5)
Can be estimated. Here, M is the mass of the vehicle, and r is the wheel radius. [If the sum of the driving forces generated at the contact points of the driving wheels on the road surface is equal to the overall driving force MG (G is acceleration) of the vehicle, the wheel torque Tw is
Tw = M · G · r (5a)
Given in The acceleration G of the vehicle is obtained from the differential value of the wheel speed r · ω,
G = r · dω / dt (5b)
Therefore, the wheel torque is estimated as shown in Equation (5). Note that the estimated wheel torque value is not estimated from the wheel speed, but from the rotational speed of the rotating shaft of the drive system operatively connected to the drive wheels, such as the engine rotational speed, the transmission rotational speed, and the turbine rotational speed. It may be. When the rotational speed ne of the output shaft of the engine or motor of the driving device is used, the wheel rotational speed of the driving wheel is
ωe = ne x transmission (transmission) gear ratio x differential (differential gear) gear ratio (6)
Given by. When using the rotational speed no of the output shaft of the transmission,
ωo = no x differential gear ratio (7)
Given by. Then, the estimated value of the wheel rotational speed ω of the drive wheel in Expression (6) or (7) is substituted into Expression (5), and the estimated wheel torque value is calculated.

(ii) Limitation of compensation component As already described, in the control of the fuel injection amount of a diesel engine, the fuel injection amount actually supplied to the engine (the execution amount of the fuel injection amount) is “a smoke generated injection amount”. It is restricted not to exceed "". As mentioned in the “Disclosure of the Invention” section, the increase or decrease of the driving torque in the diesel engine corresponds to the increase or decrease of the fuel injection amount, so that the fuel injection amount exceeds a certain ratio with respect to the intake air amount. Will increase the incomplete combustion ratio of the fuel, and smoke will be generated. Therefore, in the fuel injection amount control of a diesel engine, as described above, the smoke generation injection amount determined in accordance with the intake air amount, that is, the generation of smoke is a problem with respect to the execution amount of the fuel injection amount. Upper limit guard processing (smoke guard processing) is executed with the fuel injection amount that does not become the upper limit. Therefore, in the embodiment of the present invention, even when the basic fuel injection amount output from the drive torque request value determining unit 51 is compensated by the compensation component in order to execute the damping control, the required fuel injection amount after compensation The upper limit guard process is executed so that does not exceed the smoke generation injection amount.

In the upper limit guard process for preventing the required fuel injection amount after compensation in the embodiment of the present invention from exceeding the smoke generation injection amount, as already mentioned, the compensation injection amount limiter 52e. The vibration displacement of the compensation component is limited so as not to exceed the corresponding upper limit value (the basic fuel injection amount output from the drive torque request value determination unit 51 is known by the drive torque request value determination unit 51. It is adjusted so as not to exceed the smoke generation injection amount in an arbitrary manner.) FIG. 4A shows the configuration of the control process of the first mode of the control process of the compensation injection amount limiter 52e in the form of a control block. Referring to the figure, in the compensation injection amount limiter 52e, first, from the “guard width U _G ”, that is, the margin from the basic fuel injection amount to the smoke generation injection amount, in other words, from the basic fuel injection amount. A fluctuation range in which the fuel injection amount can be increased by the compensation component is calculated. Specifically, the guard width U _G is obtained by subtracting the basic fuel injection amount output from the drive torque request value determining unit 51 from the smoke generation injection amount in the “adder” in the drawing, that is,
U _G (guard width) = (smoke generation injection amount) − (basic fuel injection amount) (8)
Determined by. The smoke generation injection amount is obtained by estimating or acquiring the intake air amount by any known method using information such as the engine speed, the EGR execution amount, the supercharging pressure, and the like. B) may be determined using a map as exemplified in (B) may be the same as the smoke generation injection amount referred to when the basic fuel injection amount is adjusted. Note that the smoke generation injection amount is the basic fuel injection amount. If the guard width is a negative value when prepared separately from the preparation, the guard width is forcibly set to 0). The map of the smoke generation injection amount versus the intake air amount is prepared experimentally or theoretically in advance and stored in an arbitrary memory of the electronic control unit 50. Further, the calculated guard width U _G is sent to a control gain adjuster described later for determining the control gain λ.

Thus, if the guard width is calculated, the compensation component U transmitted from the compensation component determining portion 52 and the guard width U _G are compared,
_{MIN (U G, U) ...} (9)
As a result, the smaller one is selected and transmitted to the adder a1 so as to be actually superimposed on the basic fuel injection amount. Therefore, the processing of Expression (9) prohibits the vibration displacement exceeding the smoke generation injection amount in the compensation component U when superimposed on the basic fuel injection amount. Here, the compensation component is compared with the guard width U _G, usually, the FF compensation component swings to the positive side, when the vehicle decelerates, that is, when the basic fuel injection quantity is reduced, the vehicle At the time of acceleration, the FF compensation component changes to the negative side. Therefore, actually from exceeding than U _G is at the vibration displacement of the compensation component, since the FB compensation component, the compensation component determining portion 52, as shown in FIG. 2, FF compensation component determining portion 52a and the FB compensation component determining portion In the case of being divided into 52b, the compensation component limited by the equation (9) may be only the FB compensation component _UFB . In this case, the compensation component transmitted to the adder a1 is
_{U = U FF + MIN (U} G, U FB) ... (10)
It becomes. On the other hand, when the FF compensation component and the FB compensation component are collectively calculated, the compensation component used in Equation (9) may be the compensation component U output from the compensation component determination unit 52. .

(Iii) Determination of control gain When the compensation component limiting process is executed as described above, the fluctuation on the compensation component increases side by side, while the fluctuation on the compensation component reduction side continues to execute the fuel injection amount. There may be situations where the quantity is reflected. FIG. 7 exemplifies a state in which the variation of the compensation component in the execution amount of the fuel injection amount is different between the increase side and the decrease side. For example, referring to FIG. 7A, the total fuel injection amount in which the compensation component is superimposed on the basic fuel injection amount (shown as a horizontal straight line for simplicity) is the compensation component. When the smoke generation injection amount (upper limit value) is exceeded in the vicinity of the peak on the increase side (the region indicated by the oblique lines), the execution amount of the fuel injection amount is suppressed to the upper limit value during that period. . Therefore, the vibration displacement on the increase side of the vibration of the total fuel injection amount, that is, the compensation component vibration reaches a peak. However, when the vibration displacement of the compensation component is equal to or lower than the upper limit value, no limitation is imposed, and as a result, the vibration on the reduction side is directly reflected in the execution amount. Further, as shown in FIG. 7B, when the basic fuel injection amount and the smoke generation injection amount substantially coincide with each other, the increase side of the compensation component is no longer completely suppressed. The execution amount of the fuel injection amount is not displaced from the basic fuel injection amount only when the vibration of the compensation component swings to the reduction side. When the increase side vibration of the compensation component reaches a peak as described above, the wheel torque required by the vibration suppression control does not act in the increasing direction, and the vehicle receives more pitch moment in the direction of lowering the nose. It becomes.

Therefore, in order to avoid the above-described imbalance between the action on the increase side and the decrease side of the compensation component, in the embodiment of the present invention, control for controlling the control gain of the compensation component to reduce the amplitude of the compensation component is performed. A gain adjuster 52f is provided (see FIG. 2). In short, in the control gain adjuster 52f, the control gain is controlled such that the control gain of the compensation component is reduced as the guard width represented by the equation (8) is smaller. Incidentally, the control gain to be such regulatory control, as mentioned above, actually from exceeding than U _G at the vibration displacement of the compensation component is usually, since the FB compensation component, the FF compensation component There is no need to manipulate the amplitude. Therefore, in order to reduce the amplitude of only the FB compensation component, a control gain (input gain) λ _FB in for adjusting the magnitude of the input of the FB vibration suppression control may be adjusted (52d). That is, in the compensation component determination unit 52 in FIG. 2, when the wheel torque input T is divided into the FF compensation component determination unit 52a and the FB compensation component determination unit 52b, respectively,
T (FB compensation component determination unit) ← λ _FB in · Tw
T (FF compensation component determination unit) ← Two
And when calculating the FF compensation component and the FB compensation component collectively,
T ← Two + λ _FB in ・ Tw
Set to Further, when the FF compensation component determination unit 52a and the FB compensation component determination unit 52b are divided, the control gain (output gain) λ _FB out for adjusting the magnitude of the output of the FB vibration suppression control is adjusted. (52g). In that case, the compensation component passed from the FB compensation component determination unit 52b to the compensation injection amount limiter 52e is:
U _FB ← λ _FB out · −K · X (t)
It becomes. Incidentally, as already mentioned, the FF compensation component, the take FF compensation component is displaced to the increase side is when the basic fuel injection amount is decreased during deceleration of the vehicle, FF compensation component actually exceeds than U _G In this embodiment, it is not necessary to reduce the control gain of the FF compensation component.

FIG. 5A shows the control process of the control gain adjuster 52f in the form of a flowchart. FIG. 5B determines the value of the control gain in the process of FIG. A map with the guard width used as a parameter as a parameter is shown in the form of a graph. First, referring to FIG. 5A, in the control gain adjuster 52f, first, whether or not the vehicle speed is lower than a predetermined value (step 100), and whether or not the shift stage of the automatic transmission is neutral or reverse. (Step 110) and whether or not the gear position is being changed (step 120). When any one of the conditions is satisfied, the operation of the drive device or the drive system is not stable or does not require the vibration suppression control itself, so the control gain λ (λ _FB in or λ _FB out) is It is set to 0 (step 130).

On the other hand, none of the steps 100 to 120 are in when not satisfied, the map of FIG. 5 (B), the control gain λ (λ _FB in or lambda _FB out) is set to the guard width _{U G} as a parameter. As an aspect of setting the control gain, for example, as shown by the solid line in the figure, the control gain λ is equal to U _G = 0 when the guard width U _G is equal to or smaller than a predetermined value U _G0. May be gradually reduced so that λ = 0 (the predetermined value U _G0 is experimentally or theoretically set so that the amplitude of the compensation component does not exceed the guard width U _G ). May be set to.) Alternatively, λ = 0 may be set when the guard width U _G is equal to or smaller than a predetermined value U _G1 as indicated by a one-dot chain line in the drawing, and U _G = 0 as indicated by a dotted line. In this case, λ = 0 may be set. It should be understood that the mode of change in the value of the control gain λ is not limited to that illustrated in FIG. 5B, and may be arbitrarily set according to the characteristics of the engine or vehicle to which the present invention is applied. Such a case should be included in the scope of the present invention. Thus, according to the configuration as described above, the amplitude of the compensation component is adjusted on both the increase side and the decrease side by the guard width U _G , that is, the variable width of the fuel injection amount as viewed from the basic injection amount. As a result, when the compensation component is superimposed on the drive torque request value via the compensation injection amount limiter and then reflected in the execution amount of the fuel injection amount of the engine, the compensation component fluctuation increases and decreases. It is expected that the imbalance of the effect of vibration suppression control is reduced or eliminated.

(Iv) Another Mode of Compensation Component Restriction As already mentioned regarding the compensation component vibration displacement restriction processing by the compensation injection amount limiter 52e, the component that is actually restricted is mainly the FB compensation component, and the FF compensation. Since the component acts in the direction of removing the component that becomes the vibration generating force in the basic fuel injection amount when the vehicle is accelerated, the total fuel injection amount is rather reduced. Therefore, incorporating in determining in the guard width U _G to the compensation injection quantity limiter 52e, the amount of decrease in the total fuel injection amount by the FF compensation component, the guard width U _G, i.e., the allowable variation width for the FB compensation component By doing so, the contribution of the FB compensation component can be made larger in the execution amount of the fuel injection amount, thereby obtaining a greater damping effect while avoiding the peak of the FB compensation component. Is possible.

Therefore, as a second aspect of the control processing configuration of the compensation injection amount limiter 52e, the guard width _UG is determined in consideration of the reduction due to the FF compensation component in addition to the smoke generation injection amount and the basic fuel injection amount. You may be supposed to be. 6 (A) is a representation of the control process structure when FF compensation component U _FF at the determination of the guard width U _G is taken into account in block diagram form. In the case of the figure, the compensation component determination unit 52 is configured such that the FF compensation component determination unit and the FB compensation component determination unit are configured separately as illustrated in FIG. In the configuration of FIG. 6A, an FF compensation component U _FF is further input to the adder for calculating the guard width, and instead of the equation (8) in FIG. _G is
U _G = (smoke generation injection amount) − (basic fuel injection amount) −U _FF (11)
Given by. Then, the guard width U _G and the FB compensation component U _FB are compared, and the compensation component U may be calculated and sent to the adder a1 in the same manner as the above equation (10). Further, the guard width U _G calculated in this way may be sent to the control gain adjuster in order to determine the control gain λ.

  FIG. 6B shows an example of temporal changes in the FF compensation component, the guard width, and the FB compensation component when the compensation component is limited by the control processing configuration in FIG. Referring to the figure, at first (t0 to t1), when the basic fuel injection amount substantially matches the smoke generation injection amount and the guard width and the FF compensation component are 0, the FB compensation component is Even if a vibration displacement such as a dotted line in the figure is requested, since the guard width is 0, the execution amount corresponding to the FB compensation component is 0 as shown by the solid line in the figure by setting the control gain to 0. Limited to Thereafter, between t1 and t2, acceleration of the vehicle is required, and when the FF compensation component is displaced to the negative side as shown in the figure, the basic fuel injection amount remains substantially equal to the smoke generation injection amount. If the FF compensation component is not taken into account in the calculation of the guard width, the guard width does not increase (no FF correction), and therefore the variation in the injection amount required for the vibration suppression control is not achieved. However, when the FF compensation component is taken into account in the calculation of the guard width, the guard width increases by the negative displacement of the FF compensation component. Therefore, the FB compensation component is as shown by the solid line in the figure. This is partially reflected in the execution amount. Thus, according to the control configuration of FIG. 6 (A), the opportunity to change the wheel torque required by the FB compensation component is increased, and the effect of the vibration suppression control compared to the case of FIG. 4 (A). The effect can be increased.

  Although the above description has been made in relation to the embodiment of the present invention, many modifications and changes can be easily made by those skilled in the art, and the present invention is limited to the embodiment exemplified above. It will be apparent that the invention is not limited and applies to various devices without departing from the inventive concept.

  For example, although the wheel torque estimated value in the above embodiment is estimated from the wheel speed, the wheel torque estimated value may be estimated from parameters other than the wheel speed. Further, the vibration suppression control in the above embodiment is a vibration control of pitch bounce vibration using the theory of an optimal regulator assuming a sprung or sprung / unsprung vibration model as a motion model. The concept of the present invention is to adopt a motion model other than the one introduced here or to control any body vibration by a control method other than the optimal regulator as long as it uses wheel torque. Is also applied, and such a case also belongs to the scope of the present invention.

  In the example of FIG. 2, the control command for performing the compensation calculation of the drive output by the vibration suppression control is expressed and processed in units of the required fuel injection amount. The calculation process may be executed by converting the drive torque request value in the torque unit so as to be converted into the torque value unit. Further, although not shown, the adjustment of the control gain may be performed separately at the input / output of the FF compensation component, and each of the FF and FB compensation components is controlled for a reason other than the purpose of the present invention. It is to be understood that such adjustments may be further performed and such cases are within the scope of the present invention.

  Furthermore, the configuration illustrated in FIG. 6 (A) is not provided with a control gain adjuster, and therefore may be employed even in a mode in which control gain adjustment control based on the guard width is not executed. Should be understood.

FIG. 1 shows a schematic diagram of an automobile in which a preferred embodiment of a vibration damping control device according to the present invention is realized. FIG. 2 shows the internal configuration of the embodiment of the electronic control device of FIG. 1 in the form of a control block diagram. The drive torque request value determining unit 51 and the fuel injection control command determining unit 53 may be input with various parameters such as engine temperature other than those illustrated. FIG. 3A is a diagram illustrating a state variable of vehicle body vibration that is suppressed in the operation of vibration suppression control according to a preferred embodiment of the present invention. FIG. 3B is a view for explaining a “sprung vibration model” which is one of the mechanical motion models of the vehicle body vibration assumed in the vibration damping control according to the preferred embodiment of the present invention, and FIG. It is a figure explaining an upper and unsprung vibration model. FIG. 3D is a diagram showing the configuration of the compensation component determination unit in the preferred embodiment of the present invention in the form of a control block diagram. FIG. 4A shows the control processing configuration of the compensation injection amount limiter 52e in FIG. 2 in the form of a control block diagram. In the figure, the compensation component U may be the sum of the FF compensation component and the FB compensation component, or may be only the FB compensation component. FIG. 4B shows a map of the smoke generation injection amount given as a function of the intake air amount in the form of a graph. FIG. 5A shows a control processing configuration of the control gain adjuster of FIG. 2 in the form of a flowchart. The control gain λ may be either an input gain or an output gain of the FB compensation component determination unit 52. FIG. 5 (B) illustrates a map of control gain is determined as a function of the guard width U _G used in step 140 shown in FIG. 5 (A) at the form of a graph. The control gain may be either the input gain or the output gain of the feedback compensation component determination unit. FIG. 6A shows another aspect of the control processing configuration of the compensation injection amount limiter 52e of FIG. 2 in the form of a control block diagram. FIG. 6B shows an example of the temporal change of the FF compensation component, the guard width, and the FB compensation component according to the configuration of FIG. In the time change of the guard width, the case where the FF compensation component is not considered (without FF correction) and the case where the FF compensation component is considered (with FF correction) are shown in the determination. . In the time change of the FB compensation component, the required value (dotted line) of the FF compensation component determination unit and the FB compensation component (solid line) multiplied by the control gain λ _FB in are shown. The FB compensation component indicated by the solid line corresponds to a change in the contribution of the FB compensation component in the execution amount of the total fuel injection amount to the engine. FIG. 7 shows the time change of the total fuel injection amount obtained by superimposing the compensation component on the basic fuel injection amount. 7A shows a case where the basic fuel injection amount is lower than the smoke generation injection amount (upper limit value), and FIG. 7B shows a case where the basic fuel injection amount substantially matches the smoke generation injection amount. . In any case, in the prohibited region (shaded region) where the total fuel injection amount exceeds the smoke generation injection amount, the execution amount of the fuel injection amount is limited to the smoke generation injection amount (becomes a peak).

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Vehicle body 12FL, FR, RL, RR ... Wheel 14 ... Accelerator pedal 20 ... Drive device 22 ... Diesel engine 22a ... Fuel device 30FL, FR, RL, RR ... Wheel speed sensor 50 ... Electronic control device 50a ... Drive control device 50b ... Brake control device

Claims (5)

  A vibration suppression control device for a vehicle that controls a vehicle output of a vehicle using a diesel engine as a drive device and suppresses vehicle body vibration of the vehicle, the wheel generated at a ground contact point between the wheel of the vehicle and a road surface A compensation component determining unit that calculates a compensation component that compensates for the wheel torque that suppresses the amplitude of the vehicle body vibration based on the wheel torque acting on the wheel, and the wheel torque input to the compensation component determining unit or the determination of the compensation component A control gain adjusting unit that adjusts a control gain of the compensation component output from the control unit, and the control gain adjusting unit supplies basic fuel to the driving device from an upper limit value of a fuel injection amount supplied to the driving device. The apparatus is characterized in that when the difference obtained by subtracting the injection amount is small, the control gain is set smaller than when the difference is large.   2. The apparatus according to claim 1, wherein the control gain is set to 0 when the difference between the upper limit value of the fuel injection amount and the basic fuel injection amount is smaller than zero.   3. The apparatus according to claim 1, wherein the control gain is reduced as the difference between the upper limit value of the fuel injection amount and the basic fuel injection amount is smaller.   4. The apparatus according to claim 1, wherein the compensation component is a feedback compensation component that compensates for wheel torque that suppresses vehicle body vibration amplitude generated by wheel torque that is actually generated in the wheel, and the compensation component. The determination unit further calculates a feedforward compensation component that compensates for wheel torque that suppresses vehicle body vibration amplitude generated by wheel torque generated by the acceleration / deceleration request for the vehicle, and the fuel injection amount given by the feedback compensation component is In the increasing direction, it is allowed to vary within a range corresponding to a value obtained by further subtracting the feedforward compensation component from the difference between the limit value of the fuel injection amount and the basic fuel injection amount. A device characterized by.   The apparatus according to claim 4, wherein the control gain adjustment unit is based on a value obtained by further subtracting the feedforward compensation component from the difference between the limit value of the fuel injection amount and the basic fuel injection amount. The apparatus is characterized in that when the value is small, the control gain is set smaller than when the value is large.

Images