JP4867735B2 - Drive control device for controlling vibration control of vehicle - Google Patents

Description

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

  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. At the time of driving, this is reflected in “wheel torque” (torque acting between the wheel and the grounded road surface) acting on the road surface. 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, there is a request for acceleration / deceleration of the vehicle using a motion model constructed assuming a dynamic model of so-called unsprung and unsprung vibrations of the vehicle body. Or, when an external force (disturbance) acts on the vehicle body and the wheel torque fluctuates, the pitch bounce vibration generated in the vehicle body is predicted, and the drive output of the vehicle drive device is controlled so that the predicted vibration is suppressed. Adjusted.

In the vibration suppression control by the drive output control as described above, the vibration source is adjusted by adjusting the source of the force that generates the vibration rather than suppressing the vibration by absorbing the vibration energy generated as in the vibration suppression control by the suspension. Since the generation of vibration energy is suppressed, the vibration damping action is relatively quick and the energy efficiency is good. Further, in the vibration damping control based on the drive output control, since the control target is concentrated on the drive output (drive torque) of the drive device, the control adjustment is relatively easy.
JP 2004-168148 A JP 2006-69472 A Japanese Patent Publication No. 5-61468

  When the vibration suppression control by the drive output control described above is executed, the output of the drive device is vibrated more frequently than usual in order to control the wheel torque so as to suppress the pitch / bounce vibration of the vehicle. The Rukoto. In this regard, when the driving device is a gasoline engine, if there is such a fluctuation in output as described above, deterioration of fuel consumption may become a serious problem due to the action of ignition timing control for preventing knocking of the engine. It was found.

  As is well known, when the driving torque is controlled in a gasoline engine, the driving torque required for the engine (required driving torque) is realized by referring to the engine speed at that time. As described above, the ignition timing, the intake air amount, and the like are adjusted using a predetermined map. In such drive torque control, the intake air amount is controlled to increase as the required drive torque increases, and the ignition timing is basically set to the engine speed at that time and the set intake air amount. In this case, it is set to a time when the generated driving torque is maximized or the fuel consumption is the best (basic ignition timing). However, when the ignition timing is changed to the advance side along with the change in the required drive torque, if the change in the ignition timing is abrupt, there is a possibility that knocking may occur. Therefore, in the actual ignition timing control of the engine, when the ignition timing changes to the advance side, a so-called “smoothing process”, that is, a process for limiting the change of the ignition timing on the advance side is executed. (See, for example, Patent Document 3).

When the smoothing process for the change in the ignition timing as described above is executed, the ignition timing is shifted from the optimum basic ignition timing during that period, and the engine output torque is reduced and the fuel consumption is reduced. In the drive torque control in the case where normal vibration suppression control is not executed, the required drive torque changes with the acceleration / deceleration of the vehicle. Among them, the period or frequency at which the ignition timing change annealing process is actually executed is relatively small, and therefore, deterioration in fuel consumption due to the annealing process is not a significant problem. However, when the vibration suppression control as described above is executed, the required drive torque changes in a vibrational manner to reduce or cancel the pitch bounce vibration, and a steep change may occur. The time period and frequency of execution are increased, and therefore the increase in fuel consumption can be substantial and the resulting deterioration in fuel consumption can be a significant problem.

  However, as described above, the change in the ignition timing accompanying the fluctuation of the required drive torque for the vibration suppression control can lead to a considerable deterioration in fuel consumption due to the annealing process in the ignition timing control. However, no consideration is given to dealing with the problem of deterioration in fuel consumption related to the vibration damping control and the smoothing process of the ignition timing control in the conventional drive control device.

  According to the present invention, a drive control device of a type that executes drive output control for vibration suppression control of a vehicle that uses a gasoline engine as a drive device, and performs ignition timing control during the execution of vibration suppression control. There is provided a vehicle drive control device improved so as to obtain a better vibration damping effect while suppressing or reducing an increase in fuel consumption due to the smoothing process of the advance side change in ignition timing.

  A drive control device for a gasoline engine of a vehicle that controls vibration output of the vehicle and suppresses vehicle pitch or bounce vibration according to the present invention is generated at a contact point between a vehicle wheel and a road surface. A vibration suppression control unit that controls engine driving torque that suppresses pitch or bounce vibration amplitude based on wheel torque acting on the wheel; and an ignition timing control unit that controls engine ignition timing based on the required driving torque for the engine; When the ignition timing control unit advances the ignition timing, the advance amount smoothing process is executed. When the vibration suppression control is executed by the vibration suppression control unit, the advance required by the vibration suppression control is executed. The smoothing process is not executed for the angular amount. The advance amount is a change amount when the ignition timing in a certain cycle of the engine changes on the advance side from the ignition timing in the previous cycle.

  As described above, when the driving device is a gasoline engine, the smoothing process is performed on the advance side of the ignition timing in the vibrational change of the ignition timing due to the vibration fluctuation of the engine output by the vibration suppression control. When executed, the ignition timing is displaced from the basic ignition timing, which deteriorates fuel consumption. Therefore, in the apparatus of the present invention, as described above, the smoothing process is not executed for the advance amount required by the vibration suppression control at the time of execution of the vibration suppression control by the vibration suppression control unit. In other words, the configuration of the ignition timing control is modified so as not to limit the change in the ignition timing that is frequently requested by the vibration suppression control. According to such a configuration, if the change amount (advance amount) on the advance side of the ignition timing corresponding to the fluctuation of the required drive torque for vibration suppression control is originally, the smoothing process should be executed. Even if it is large, since the smoothing process is not executed, the ignition timing is based on the required ignition torque and the basic ignition timing determined corresponding to the target values of the engine speed and the intake air amount at that time. A value closer to that time will be set. Therefore, the magnitude of the deviation of the actual ignition timing from the basic ignition timing and the period in which the deviation occurs are reduced, and the fuel consumption deteriorates due to the fact that the vibration suppression control requires a change in the vibration demand drive torque. Will be avoided. Note that a smoothing process may be executed for a change on the advance side of the ignition timing corresponding to a change in the required drive torque for acceleration / deceleration of the vehicle.

  As an embodiment of the drive control device of the present invention described above, the smoothing process of the change of the ignition timing to the advance side in the ignition timing control may be executed by any type or technique, for example, the advance angle It may be executed in a form that limits the amount to a predetermined value or less. In the case of this type of smoothing process, as one aspect, the ignition timing control unit ignites the advance amount required by the vibration suppression control when the advance amount required by the vibration suppression control exceeds a predetermined value. The time may be advanced. Here, the advance amount required by the vibration suppression control is the advance amount corresponding to the change in torque that contributes to the vibration suppression control among the changes in the required drive torque for the engine, that is, acceleration / deceleration of the vehicle. This is the advance amount excluding the advance amount with respect to the change in the drive torque related to.

  As described above, when the advance amount required by the vibration suppression control exceeds a predetermined value, the current (( The difference between the basic ignition timing (current basic ignition timing) corresponding to the required drive torque (to be achieved from now) and the ignition timing already executed (previous ignition timing), that is, the advance amount is affected by the smoothing process. Probability is high. Therefore, if the advance amount required by the vibration suppression control has exceeded the predetermined value of the smoothing process, the ignition timing is set to the advance amount required by the vibration suppression control from the previous ignition timing. Control is performed so that the ignition timing advances due to vibration suppression control, so that the smoothing processing is not performed for the advance timing of the ignition timing, which is closer to the basic ignition timing, thereby suppressing deterioration in fuel consumption. It may be like this. Further, according to such a configuration, the drive torque request by the vibration suppression control is reflected in the engine output, so that the effect of the vibration suppression control is maintained. As another mode, in the control for advancing the ignition timing by the advance amount required by the vibration suppression control from the previous ignition timing, the advance amount of the current basic ignition timing from the previous ignition timing is a predetermined value of the smoothing process. It may be executed when it exceeds the limit.

  Although the advance amount required by the vibration suppression control does not exceed a predetermined value, the difference between the current basic ignition timing determined based on the required driving torque and the current ignition timing (previous ignition timing) is a predetermined smoothing process. When the value is exceeded, the ignition timing may be advanced by a predetermined value of the annealing process. In this case, the advance amount required by the vibration suppression control is entirely reflected in the actual ignition timing, and the advance amount other than the advance amount required by the vibration suppression control, that is, acceleration / deceleration of the vehicle. Therefore, the smoothing process is executed for the advance amount of the ignition timing with respect to the change in the required drive torque.

  The calculation of the advance amount required by the vibration suppression control may be performed by an arbitrary method depending on the system configuration of the drive control device that executes the vibration suppression control. The drive control device of the present invention includes a required drive torque determining unit that determines the required drive torque, and the vibration suppression control unit corrects the required drive torque based on the required drive torque compensation component calculated based on the wheel torque. In this case, the advance amount required by the vibration suppression control is determined based on a basic ignition timing (vibration suppression) determined from a value obtained by adding a change in the required drive torque compensation component to the current generated torque of the engine. It may be calculated based on the difference between the basic ignition timing considering only the change in the required drive torque due to control) and the current ignition timing (previous ignition timing).

  According to the drive control device of the present invention described above, if necessary, when the pitch bounce vibration suppression control by the drive output control is executed in the gasoline engine, the change in the ignition timing of the engine due to this is controlled. On the other hand, by not performing the annealing process, the degree of deterioration of fuel consumption is reduced. According to the control method of the present invention, the change in the ignition timing corresponding to the change in the drive torque required by the vibration suppression control is substantially realized, and in particular, there is no change in the required drive torque related to the acceleration / deceleration of the vehicle. Sometimes, theoretically, it is almost completely realized, so that the vibration control effect by the vibration suppression control is also realized well.

  It should be particularly understood that in the pitch / bounce vibration suppression control that is the subject of the present invention, the engine load request required by the driver or the automatic travel control device related to the acceleration / deceleration of the vehicle is: In addition, a somewhat unique drive control is sometimes performed in which the vertical vibration of the drive torque is required for the purpose of independently canceling the pitch bounce vibration. In the case of engine drive control for the purpose of accelerating / decelerating the rotation of a typical vehicle or wheel, generally, the change in drive torque required for the engine is a request from the driver or an automatic travel control device or the like Therefore, the value of the required drive torque for the engine rarely fluctuates frequently, vibrationally, or steeply. Therefore, the ignition timing of the engine hardly changes greatly vibrationally. it is conceivable that. However, in the case of drive output control in pitch bounce vibration control, the required drive torque is essentially vibrational, and its amplitude is steep when suppressing vibration due to disturbance to wheel torque. Therefore, there may occur a situation in which a frequent or sudden change in the ignition timing is required. The control configuration of the present invention pays attention to the situation that occurs in such a unique control method of the pitch / bounce vibration suppression control, and when the pitch / bounce vibration suppression control is incorporated in the drive control of the gasoline engine, -It can be said that the bounce vibration suppression control and the existing ignition timing smoothing process are coordinated, the deterioration of fuel consumption is suppressed, and the vibration suppression effect is effectively exhibited.

  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.

Configuration of Apparatus FIG. 1A schematically shows a vehicle such as an automobile on which a preferred embodiment of a drive control apparatus that executes vibration suppression control of the present invention is mounted. 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 gasoline engine in a known manner, and the throttle valve 22a has a throttle valve 22a for adjusting the intake air amount so as to achieve the required drive torque determined according to the depression amount of the accelerator pedal and the control amount described below. The opening degree and the ignition timing of the spark plug 22b are controlled. Although not shown for 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.

  Engine control parameters such as engine 22 drive output, that is, throttle opening, ignition timing, and the like are adjusted by commands of 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 Signals such as engine rotation speed ne, accelerator pedal depression amount θa, and the like are input from sensors provided in the respective parts. 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. As schematically shown in more detail in FIG. 1B, the electronic control device 50 includes a drive control device 50a for controlling the operation of the engine and other drive devices 20, and a braking device (not shown). ) Of the brake control device 50b for controlling the operation of 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.

  In the drive control device 50a, the drive request from the driver is determined based on the accelerator pedal depression amount θa, the required drive torque determining unit 51 for determining the required drive torque of the engine requested by the driver, and the vehicle body by the drive torque control. And a vibration suppression control unit 52 that calculates a required drive torque compensation component for executing the pitch / bounce vibration vibration suppression control of and corrects the required drive torque. In the pitch / bounce vibration damping control, as will be described in more detail later, (1) calculation of the estimated wheel torque of the driving wheel by the force acting between the driving wheel and the road surface; 2) Calculation of the pitch / bounce vibration state quantity based on the motion model of vehicle body vibration, (3) Calculation of the correction amount of the wheel torque for suppressing the pitch / bounce vibration state quantity, and correction of the required drive torque based on this. Then, the command value of the required drive torque corrected by the vibration suppression control unit 52 is sent to an engine operation parameter determination unit or a control command determination unit 53 that determines a target value of a control parameter that determines engine operation.

  The engine operating parameter determination unit 53 refers to the engine speed at that time, and uses a map determined experimentally or theoretically in advance, and intake air that realizes the required drive torque in the engine An amount target value, ignition timing, fuel injection amount, and the like are determined. In this regard, as is well known, in a gasoline engine, generally speaking, the engine output (power), that is, the engine output torque × by varying the intake air amount, ignition timing, and fuel injection amount. The rotational speed fluctuates. However, the engine speed is mechanically restricted by the vehicle speed, and the vehicle speed is not changed instantaneously. Therefore, in the drive torque control, the engine rotational speed is referred to as one of input parameters, and the torque actually output from the engine is controlled by adjusting the engine operating parameter.

Regarding the operating parameters in the drive torque control described above, the fuel injection amount has an optimum amount that achieves an optimum air-fuel ratio following the intake air amount. As for the ignition timing, as already mentioned in the “Disclosure of the Invention” section, there is an optimum value that maximizes the torque and minimizes the fuel consumption for any engine speed and any intake air amount. (See note below). Therefore, in determining the operating parameters in the drive torque control, the fuel injection amount gives the optimum air-fuel ratio at the engine speed at that time, and the ignition timing maximizes the torque to minimize the fuel consumption. Is set to an optimum timing (referred to as “basic ignition timing”), the target value of the intake air amount that gives the required drive torque is determined using the previously determined map. After that, the fuel injection amount (not shown) and the ignition timing (ignition timing control unit 55) are determined from the map of the engine speed and the target value of the determined intake air amount. It is determined. In controlling the intake air amount, “load factor” is used as an index value of the intake air amount. The load factor is a value obtained by dividing the amount of air sucked in one intake stroke by the amount of air sucked in one intake stroke when the throttle is fully opened, that is, one intake stroke when the throttle is fully opened. This is the ratio of the intake air amount in one intake stroke when the intake air amount in this case is 100%. The intake air amount in one intake stroke is calculated by dividing the intake air amount per unit time at the intake inlet by the engine speed at that time. Since the load factor changes with the charging efficiency of the cylinder, and the charging efficiency changes with the intake pipe pressure, the intake pipe pressure may be used as an index value of the intake air amount.
[(Note) In an actual engine with a finite combustion period, the earlier the ignition timing, that is, the more it changes to the advance side, the compression work before the top dead center of the piston in the engine cylinder ( Mechanical loss, cooling loss, etc.) increase, and the ignition timing is delayed, that is, the more it changes to the retard side, the smaller the expansion ratio becomes and the exhaust loss increases. The cause of the decrease in the engine output on the advance side and the retard side depends on the engine speed and the intake air amount. Therefore, the ignition timing at which the output and the fuel efficiency are best varies depending on the engine speed and the intake air amount. Will be. ]

  Thus, when the engine operating parameter is determined, the parameter is transmitted to each part of the engine as a control command, and adjustment control is executed. However, as will be described in detail later, when the command value changes to the advance side, as will be described in detail later, if the change, that is, the advance amount is large, there is a high possibility that an engine knock phenomenon will occur. Therefore, a so-called “smoothing process”, that is, a process for limiting the amount of advancement so as not to change to the advance side more than a predetermined value at a time is executed.

  It should be understood that each part of the drive control device of the present invention described above is realized by a processing operation of a microcomputer or the like in the electronic control device 50. Hereinafter, the configuration and operation of vibration suppression control by drive torque control and ignition timing control executed in cooperation with the vibration suppression control will be described in detail.

FIG. 2 (A) shows an example of a drive torque control configuration in which the vehicle body pitch / bounce vibration damping control is performed . In the vehicle body 10 as described above, bounce vibration in the vertical direction (z direction) of the center of gravity Cg of the vehicle body and pitch vibration in the pitch direction (θ direction) around the center of gravity of the vehicle body can occur. Further, when an external force or torque (disturbance) acts on the wheels from the road surface while the vehicle is running, the disturbance is transmitted to the vehicle, and vibrations in the bounce direction and the pitch direction may also occur in the vehicle body. 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 the required drive torque (value converted to wheel torque) in the model, A state obtained from the model by calculating 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 when the current wheel torque (estimated value) is input. The drive torque of the drive device (engine) is adjusted so that the variable converges to 0, that is, the pitch / bounce vibration is suppressed (the required drive torque is corrected).

FIG. 2B schematically shows the configuration of the drive torque control in the embodiment of the present invention in the form of a control block. The operation of each control block is executed by either the drive control device 50a or the braking control device 50b of the electronic control device 50 (except for C0 and C3). Referring to FIG. 2B, in the drive torque control according to the embodiment of the present invention, a required drive torque determination unit 51 that gives a driver's drive request to the vehicle, and suppresses pitch / bounce vibration of the vehicle body. It is comprised from the vibration suppression control part 52 for correcting the driver | operator's drive request (refer FIG.1 (B)). In the required drive torque determination unit, the driver's drive request, that is, the accelerator pedal depression amount (C0) is converted into the required drive torque in a normal manner (C1), and then the required drive torque is calculated. The target load factor (target intake air amount) and the target throttle opening are converted in this order to determine the control command to the throttle valve actuator, and the ignition timing, fuel injection amount, etc. based on the target load factor and engine speed The target values of the other operating parameters are also determined (C2) and transmitted to the drive unit (C3). Although not shown in FIG. 2 (B), when the ignition timing changes to the advance side, the ignition timing control unit 55 (see FIG. 1 (B)) will be described later. In an aspect, an annealing process is performed.

  On the other hand, the vibration suppression control unit includes a feedforward control part and a feedback control part. The feedforward control portion has a so-called optimum regulator configuration, and here, as described below, a value obtained by converting the required driving torque of C1 into wheel torque (driver required wheel torque Tw0) is the pitch of the vehicle body. The motion model portion (C4) of the bounce vibration is input, and in the motion model portion (C4), the response of the state variable of the vehicle body to the input torque is calculated, and the required driving wheel torque that converges the state variable to the minimum is calculated. A correction amount is calculated (C5). In the feedback control portion, the wheel torque estimator (C6) calculates a wheel torque estimated value Tw as will be described later, and the wheel torque estimated value is calculated based on the feedback control gain FB (in the driving model). After the driver requested wheel torque Tw0 and the gain for adjusting the balance of contribution between the wheel torque estimated value Tw) are multiplied, the disturbance input is added to the requested wheel torque and input to the motion model portion (C4). Thereby, the correction amount of the required wheel torque with respect to the disturbance is also calculated. The correction amount of the required wheel torque of C5 is converted into the required torque unit of the drive device (required drive torque compensation component) and transmitted to the adder (C1a). Thus, the required drive torque is obtained by the pitch bounce vibration. After being corrected so as not to occur, it is converted into a control command (C2) and given to the driving device (C3).

The wheel torque input as a disturbance to the feedforward control part may ideally be detected by actually providing a torque sensor for each wheel, but a torque sensor should be provided for each wheel of a normal vehicle. It is difficult. Therefore, in the illustrated example, the wheel torque estimated value estimated by the wheel torque estimator (C6) 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). ]

Principle of Vibration Suppression Control In the vibration suppression control in the embodiment of the present invention, as already mentioned, first, assuming the dynamic motion model in the bounce direction and the pitch direction of the vehicle body, the driver requested wheel A state equation of state variables in the bounce direction and the pitch direction is input with the torque Tw0 and the estimated wheel torque value Tw (disturbance) as inputs. Then, from this state equation, the input (torque value) for converging the bounce and pitch state variables to 0 is determined using the theory of the optimal regulator, and the required drive torque is corrected based on the obtained torque value. The

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、第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している車輪トルクＴ（＝Ｔｗ０＋Ｔｗ）が車体の重心周りに与える力のモーメント成分である。 As a dynamic motion model in the bounce direction and pitch direction of the vehicle body, for example, as shown in FIG. 3A, the vehicle body is regarded as a rigid body S of mass M and moment of inertia I, and the rigid body S has an elastic modulus kf. And a front wheel suspension with a damping rate cf, and a rear wheel suspension with an elastic modulus kr and a damping rate cr (car 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 Equation (1a), the first and second terms are components of force from the front wheel shaft, and the third and fourth terms are components of force from the rear wheel shaft. In Equation (1b), the first term Is the moment component of the force from the front wheel shaft, and the second term is 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 (= Tw0 + Tw) generated in the drive wheel gives around 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.

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。 Note that Q and R in the evaluation function J and Riccati equation are respectively a semi-positive definite symmetric matrix and a positive definite symmetric matrix, which 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.

  As shown in the block diagram of FIG. 2B, the actual operation of the vibration suppression control unit is performed by solving the differential equation of the equation (2a) using the torque input value in the motion model C4. A state variable vector X (t) is calculated. Next, at C5, the value U () obtained by multiplying the state vector X (t), which is the output of the motion model C4, by the gain K determined to converge the state variable vector X (t) to 0 or the minimum value as described above. t) is subtracted from the required driving torque in the adder (C1a) (converted to the torque of the driving device) (for the calculation of the movement model C4, it is also fed back to the torque input value of the movement model C4). (State feedback). The system represented by equations (1a) and (1b) is a resonant system, and for any input, the value of the state variable vector is substantially the natural vibration of the system. Only frequency components of a band having a certain spectral characteristic centered on the number are obtained. Thus, by constructing the converted value of U (t), that is, the required driving torque compensation component, from the required driving torque, in the required driving torque, the natural frequency component of the system, ie, the vehicle body. The component causing the pitch bounce vibration is corrected, and the pitch bounce vibration in the vehicle body is suppressed. When a fluctuation that causes pitch bounce vibration occurs in Tw (disturbance) transmitted from the wheel torque estimator, a required torque command that is input to the drive device so that the vibration due to the Tw (disturbance) converges. Is modified using -U (t).

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（Ａ）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。実際の制振制御は、図３（Ａ）の場合と同様である。 As a dynamic motion model in the bounce direction and the pitch direction of the vehicle body, for example, as shown in FIG. 3B, in addition to the configuration of FIG. A model that takes into account the above (vehicle body sprung / lower vibration model) may be employed. Assuming that the tires for the front wheels and the rear wheels have the elastic moduli ktf and ktr, respectively, the equation of motion in the bounce direction and the equation of motion 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), similarly to the case of FIG. 3A, with z, θ, xf, xr and their time differential values as state variable vectors. (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. Actual vibration suppression control is the same as in the case of FIG.

As described above, the command value of the required drive torque determined by the required drive torque determining unit 51 and corrected by the vibration damping control unit 52 is transmitted to the engine operating parameter determining unit 53 as to ignition timing control . In the engine operating parameter determining unit 53, the intake air amount determining unit determines in advance from the engine speed at that time and the command value of the required driving torque as illustrated in FIG. Using the map, a load factor that is an index value of the intake air amount that achieves the required drive torque is determined. Then, the basic ignition timing is determined from the load factor and the engine speed using a map as illustrated in FIG. 4B.

  As described above, the basic ignition timing is an ignition timing that is set so that the torque is maximum or the fuel efficiency is the best. In particular, when the engine load is low, the change in torque due to the change in the ignition timing is small, so the map is configured so that it is determined with an emphasis on the best fuel economy. Regarding the determination of the ignition timing, as understood from the map of FIG. 4B, the basic ignition timing is set to the advance side as the load factor is lower. This is because, when the load factor (intake air amount) is low, the combustion rate is reduced because the turbulence of the working gas generated in the intake stroke is quickly attenuated and the negative pressure in the intake pipe is large and the ratio of residual gas is large. This is because it is preferable that the ignition is performed earlier as the load factor is lower. Also, when the engine speed increases, the absolute time from ignition to heat generation is almost constant, whereas the stroke proceeds faster, so that the basic ignition timing changes to the advance side as the speed increases. Is set. Therefore, as indicated by the arrow in FIG. 4B, the basic ignition timing is set to the advance side as the load factor is lower and as the rotational speed is higher. (In driving torque control, it is understood that the relationship between intake air amount or load factor, basic ignition timing, and generated torque is obtained in advance experimentally or theoretically, and a map is constructed based on such relationship. Accordingly, the target value of the load factor is set to a load factor that generates the required drive torque when ignition is performed at the basic ignition timing as a function of the required drive torque. In the control flow, the basic ignition timing is determined after the load factor is determined. However, when the required drive torque is applied, the basic ignition timing is directly referred to the engine speed. May be determined.)

  Thus, when the load factor and the basic ignition timing are determined as described above, basically, the throttle opening and ignition of the spark plug are executed based on these values. However, when the ignition timing changes to the advance side when the ignition timing changes to the advance side, there is a high possibility that engine knocking will occur. As illustrated, an “annealing process” is performed so that the amount of change in ignition timing, that is, the advance amount does not exceed a predetermined value. In this “annealing process”, as understood from the figure, even if the basic ignition timing changes as indicated by the one-dot chain line in the figure based on the command value of the required drive torque, the actual ignition timing is It is changed to the advance side by a predetermined value. As described above, the advance timing of the ignition timing is required when the required drive torque decreases and the load factor decreases (the engine speed is constrained by the vehicle speed, so it is difficult to change suddenly). When the required drive torque changes relatively steeply, the advance angle of the ignition timing, that is, the gradient of the change in the ignition timing is limited (if it changes to the retard side, there is little concern about the occurrence of knocking). Therefore, ignition is executed at the basic ignition timing).

  As described above, while the smoothing process is executed and the advance timing of the ignition timing is limited, the actual ignition timing will deviate from the basic ignition timing, so the output decreases during that time and the fuel consumption is not optimal. As a result, fuel consumption will deteriorate. Of course, during normal driving of the vehicle, as described above, the frequency and the period in which the ignition timing is steep, that is, the change exceeding the predetermined value of the annealing process is required are not so many. Don't be. However, while the vibration suppression control is being executed, the required driving torque fluctuates in a vibrational manner. Accordingly, as illustrated in FIG. 5B, the basic ignition timing is also fluctuating. To change. Therefore, as can be easily understood, the frequency and period of time when the request for changing the ignition timing to the advance side is increased, and in this case, deterioration of fuel consumption due to the annealing process may be a problem.

  Therefore, in the drive control device according to the embodiment of the present invention, the ignition timing control unit does not execute the annealing process for the change in the ignition timing caused by the required drive torque compensation component of the vibration suppression control. The control arrangement is modified as described below.

  FIG. 6A shows, in the form of a flowchart, ignition timing setting processing that is repeatedly executed at a predetermined cycle time during operation of the vehicle in the ignition timing control unit in the drive control apparatus of the present invention. Is. In the example shown in the figure, the change in the ignition timing on the advance side is positive. Referring to the figure, first, the basic ignition timing is determined from the engine speed and the load factor determined by the intake air amount determination unit using a map as shown in FIG. 10) It is determined whether or not the basic ignition timing has changed to the advance side compared to the previous ignition timing, that is, the ignition timing of the ignition that has already been performed (step 20). If the basic ignition timing has not changed to the advance side, the basic ignition timing is set to the current ignition timing as it is (step 90).

On the other hand, if the basic ignition timing has changed to the advance side, it is determined whether vibration suppression control is being executed, that is, whether the required drive torque vibration for suppressing the pitch bounce vibration has occurred. Determination is made (step 30). In this determination, for example, referring to the required drive torque compensation component U (output of C5) and its time differential value in the vibration suppression control unit, when their absolute values are both smaller than a predetermined minute amount. In other words, when it is substantially 0, it may be determined that the vibration suppression control is not operating.
When the vibration suppression control is not executed, the advance amount smoothing process is executed in the same manner as in the previous ignition timing control (step 40).

  In the annealing process, it is determined whether or not the difference between the basic ignition timing and the previous ignition timing, that is, the advance amount required based on the required drive torque is greater than a predetermined value (step 40). ). If the amount of advance is larger than a predetermined value, the amount of advance is limited. Therefore, the actual ignition timing this time is a value obtained by adding a predetermined value to the previous ignition timing (step 50). Thus, it is avoided that the ignition timing changes to the advance side excessively steeply. On the other hand, if the advance amount is not larger than the predetermined value, the basic ignition timing calculated in step 10 is set to the current ignition timing as it is (step 90).

  If it is determined in step 30 that the vibration suppression control is being executed, as described above, the advance amount of the ignition timing corresponding to the change in the required drive torque compensation component of the vibration suppression control is smoothed. The ignition timing is set so that the advance amount is reflected without applying. However, also in this case, it is preferable that the smoothing process is applied to a change on the advance side for reasons other than vibration suppression control (usually for acceleration / deceleration of the vehicle).

  Therefore, if it is determined that the vibration suppression control is being executed, first, the advance amount of the ignition timing required by the change in the required drive torque compensation component of the vibration suppression control is calculated (step 60). It is determined whether or not the predetermined value of the smoothing process is exceeded only by the advance amount of the ignition timing resulting from the vibration suppression control (step 70). If the predetermined value of the smoothing process is exceeded only by the advance amount of the ignition timing caused by the vibration suppression control, in such a situation, if the change of the advance side is requested for reasons other than the vibration suppression control, Since the advance amount by the damping control is also reflected, the ignition timing can be excessively advanced to the advance side. Therefore, if the amount of change in the ignition timing caused by the vibration suppression control exceeds the predetermined value of the annealing process, the current ignition timing is the advance amount of the ignition timing caused by the vibration damping control at the previous ignition timing. (Step 80). As a result, the advance amount required for reasons other than the vibration suppression control is subjected to a smoothing process (in this case, it is smoothed to 0), but the advance amount of the ignition timing resulting from the vibration suppression control. Is reflected in the advance of the ignition timing without being subjected to the annealing process.

  On the other hand, if only the amount of change in the ignition timing due to the vibration suppression control does not exceed the predetermined value of the annealing process, the annealing process in steps 40 and 50 is executed as in the previous case, This ignition timing is determined. In this case, since it is known that the amount of change in the ignition timing caused by the vibration suppression control does not exceed the predetermined value, here, when the advance amount of the ignition timing is set to the predetermined value, the vibration suppression control is performed. The resulting change amount of the ignition timing is reflected as it is, and the value of the advance amount required for reasons other than the vibration suppression control is rounded.

  Thus, when the current ignition timing is determined, a control command is transmitted to an ignition plug operation control device (not shown) so that the ignition plug ignites at the ignition timing. The current ignition timing is stored as the previous ignition timing in the next cycle (step 100).

  The amount of change in the ignition timing caused by the vibration suppression control in step 60 is calculated in the same manner as the basic ignition timing determination process using the maps of FIGS. 4A and 4B, for example. (See FIG. 6B). In this case, first, the torque generated in the current engine (or the required drive torque corresponding thereto) is calculated by an arbitrary method (step 110). Next, the load factor corresponding to the (virtual) torque value obtained by adding the amount of change (from the value in the previous cycle) of the required drive torque compensation component by the vibration suppression control unit to the engine torque, Calculation is performed using a map as shown in FIG. 4A (step 120). Thus, if the virtual basic ignition timing is calculated from the load factor corresponding to the obtained virtual torque value using the map illustrated in FIG. 4B (step 130), it results from the vibration damping control. The amount of change in the ignition timing is given by the difference between the basic ignition timing and the previous ignition timing (giving the current generated torque) (step 140). (If there is no factor for changing the ignition timing other than the vibration suppression control, the virtual basic ignition timing is the same as the basic ignition timing calculated in step 10).

  Thus, according to the above ignition timing setting process, the advance amount of the ignition timing resulting from the vibration suppression control is reflected in the actual ignition timing regardless of the annealing process. Does the actual ignition timing match the basic ignition timing (when there is no factor that changes the ignition timing other than vibration suppression control, the actual ignition timing is the basic ignition timing indicated by the one-dot chain line in FIG. ), The deviation of the actual ignition timing from the basic ignition timing is reduced, so that even if the vibration suppression control is executed, it is expected to be suppressed to the extent that deterioration of fuel consumption does not become a problem. The In addition, since the ignition timing is controlled as required for damping control, it is expected that a good damping effect is exhibited.

  In the process shown in FIG. 6A, whether or not the vibration suppression control is executed has been determined prior to the determination of the difference between the current basic ignition timing and the previous ignition timing. The determination as to whether or not the difference between the basic ignition timing and the previous ignition timing exceeds a predetermined value of the smoothing process may be performed prior to determining whether or not the vibration suppression control is performed (see FIG. 7). In this case, after the calculation of the current basic ignition timing (step 10), it is determined whether or not the difference between the current basic ignition timing and the previous ignition timing exceeds a predetermined value of the annealing process (step 20 ′). When the difference exceeds a predetermined value, it is determined whether or not the vibration suppression control is being executed (step 30 '). During execution of vibration suppression control, calculation of the advance amount of the ignition timing resulting from the vibration suppression control (step 40 '), and the advance amount of the ignition timing resulting from the vibration suppression control, as described above. Determination of the magnitude relationship with the predetermined value of the process is made (step 50 '), and if the advance amount of the ignition timing resulting from the vibration suppression control exceeds the predetermined value, the current ignition timing is suppressed to the previous ignition timing. It is assumed that the advance amount of the ignition timing resulting from the control is added (step 60 '). On the other hand, when the advance amount of the ignition timing resulting from the vibration suppression control does not exceed the predetermined value, the current ignition timing is assumed to be added to the previous ignition timing by the predetermined value of the annealing process (step 70 ′). .

  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 suppression control using the theory of an optimal regulator assuming a sprung or sprung / unsprung movement model as a movement model. As long as it uses wheel torque, it can also be applied to those that adopt a motion model other than those introduced here, or those that control vibration using a control method other than the optimal regulator. It belongs to the scope of the invention.

FIG. 1A shows a schematic diagram of an automobile in which a preferred embodiment of a drive control apparatus according to the present invention is realized. FIG. 1B is a more detailed schematic diagram of the internal configuration of the electronic control device of FIG. 1A. FIG. 2A is a diagram illustrating a state variable of vehicle body vibration that is suppressed in the operation of the vibration suppression control unit of the drive control device that is one of the preferred embodiments of the present invention. FIG. 2B is a diagram showing the configuration of the vibration damping control in the preferred embodiment of the present invention in the form of a control block diagram. FIG. 3 is a diagram for explaining a mechanical motion model of vehicle body vibration assumed in the vibration damping control unit of the preferred embodiment of the present invention. FIG. 3A shows a case where a sprung vibration model is used, and FIG. 3B shows a case where a sprung / unsprung vibration model is used. FIG. 4A is a map for determining the target load factor from the engine speed and the required drive torque. In the figure, the alternate long and short dash line indicates the contour line of the generated torque. The generated torque increases in the direction of the arrow. When the required drive torque is given, the load factor (vertical axis) that generates the torque is selected as the target load factor. FIG. 4B is a map for determining the basic ignition timing from the target load factor and the engine speed. In the figure, the alternate long and short dash line indicates the contour line of the ignition timing that occurs. The basic ignition timing changes to the advance side or the retard side in the direction of the arrow. FIG. 5A shows a time change when the actual ignition timing (solid line) is subjected to a smoothing process with respect to the change of the basic ignition timing (one-dot chain line). FIG. 5B shows a time change of the basic ignition timing (one-dot chain line) and the actual ignition timing (solid line) subjected to the annealing process in the change on the advance side while the vibration suppression control is executed. . During the period in which the basic ignition timing (one-dot chain line) and the actual ignition timing (solid line) deviate, fuel consumption deteriorates. FIG. 6A shows the ignition timing setting process in the ignition timing control unit of the present invention in the form of a flowchart. FIG. 6B shows a process of calculating the advance amount required by the vibration suppression control in step 60 of FIG. 6A in the form of a flowchart. FIG. 7 shows a modification example of the ignition timing setting process of FIG. 6A in the form of a flowchart.

Explanation of symbols

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

Claims (5)

A drive control device for a gasoline engine of a vehicle that controls a vehicle drive output to suppress a pitch or bounce vibration of the vehicle, and is generated at a ground contact point between the vehicle wheel and a road surface A damping control unit that controls the driving torque of the engine that suppresses the pitch or bounce vibration amplitude based on the wheel torque acting on the wheel, and controls the ignition timing of the engine based on the required driving torque for the engine An ignition timing control unit that performs an advance amount smoothing process when the ignition timing control unit advances the ignition timing, but when executing the damping control by the damping control unit, Of the advance amounts determined in response to changes in the required drive torque, the advance amount required by the vibration suppression control is determined, and the advance angle amount required by the vibration suppression control By performing the smoothing processing with respect to the advance amount required by other than the damping control to always be reflected at the ignition timing, the required driving torque for acceleration or deceleration of the vehicle While allowing the execution of the smoothing process for the advance amount required by the change, the driving of the vehicle, characterized in that does not execute the smoothing process for the advance amount required by the damping control Control device.   2. The apparatus according to claim 1, wherein the smoothing process of the advance amount of the ignition timing is executed by limiting the advance amount to a predetermined value or less, and the ignition timing control unit includes the control unit. When the advance amount required by vibration control exceeds the predetermined value, the ignition timing is advanced by the advance amount required by the vibration suppression control.   The apparatus according to claim 2, further comprising a required drive torque determining unit that determines the required drive torque, wherein the vibration suppression control unit calculates the required drive based on a required drive torque compensation component calculated based on the wheel torque. When the torque is corrected and the ignition timing control unit determines that the advance amount required by the vibration suppression control does not exceed the predetermined value, the basic ignition timing determined based on the corrected required driving torque and the current When the difference from the ignition timing exceeds the predetermined value, the ignition timing is advanced by the predetermined value.   The apparatus according to claim 2, further comprising a required drive torque determining unit that determines the required drive torque, wherein the vibration suppression control unit calculates the required drive based on a required drive torque compensation component calculated based on the wheel torque. The torque is corrected, and the ignition timing control unit is requested by the vibration suppression control when the difference between the basic ignition timing determined based on the corrected required driving torque and the current ignition timing exceeds the predetermined value. When the advance angle amount exceeds the predetermined value, the ignition timing is advanced by the advance amount required by the vibration suppression control. The apparatus according to claim 1, further comprising a required drive torque determining unit that determines the required drive torque, wherein the vibration suppression control unit calculates the required drive based on a required drive torque compensation component calculated based on the wheel torque. The basic ignition timing and the current ignition timing determined by correcting the torque and determining the advance amount required by the vibration suppression control from a value obtained by adding a change in the required driving torque compensation component to the current generated torque of the engine An apparatus that is calculated based on the difference between

Images