JP2000257468A - Vehicle drive force controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent unnecessary correction of drive force during an engine torque fluctuation by decreasing calculation errors of the road load increase amount. SOLUTION: A controller corrects an estimated normal state engine torque ENGTRQ#m to estimate a true engine torque ENGTRQ and calculates a running resistance increase RESTRQ by subtracting a reference running resistance RLDTRQ and an acceleration resistance GTRQ from a vehicle drive force TRQOUT that is obtained by multiplying the true engine torque ENGTRQ by a gear ratio RATIO. The controller then calculates a drive force correction ADDFD, according to the running resistance increase RESTRQ, and corrects the drive force of a vehicle. Therefore, calculation error in the running resistance increase RESTRQ is decreased, and thus unnecessary correction of the drive force due to calculation error can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle driving force control device for controlling a driving force of a vehicle, and more particularly to a device for changing a driving force characteristic according to a running resistance.

[0002]

2. Description of the Related Art When a vehicle is traveling on an uphill road, the resistance received by the vehicle is increased due to the gradient. Therefore, if the vehicle driving force remains on a flat road, the driver will feel insufficient acceleration. . In order to eliminate the insufficient acceleration, the driver needs to depress the accelerator pedal to increase the engine torque to compensate for the increase in the resistance. In this regard, the driving force control disclosed in Japanese Patent Application Laid-Open No. 9-242862 The device estimates the road gradient and changes the driving force characteristic according to the gradient so that the acceleration does not slow down even if the driver does not perform such an accelerator operation.

[0003]

[Problems to be solved by the invention]
In the above-described conventional driving force control device, a steady engine torque is estimated from the throttle opening and the engine speed, and an acceleration resistance or the like is subtracted from the estimated steady engine torque to calculate an increase amount (gradient resistance) of the running resistance. Therefore, the calculation error of the running resistance increase amount was large.

[0004] This is because the actual engine torque does not immediately become the steady-state engine torque, but rises later than the estimated steady-state engine torque at the initial stage of acceleration. If the amount of increase in the running resistance is calculated by subtracting it, the difference between the estimated steady-state engine torque and the actual engine torque is considered to be due to the increase in the running resistance.

For this reason, in the above-mentioned conventional driving force control device, when the engine torque fluctuates, the driving force is corrected more than necessary, and the vehicle is accelerated too much, and the driver feels uncomfortable, such as a sudden rush. Could be felt.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in the prior art, and reduces a calculation error of a running resistance increase amount in a driving force control device, and does not perform unnecessary driving force correction when engine torque fluctuates. The purpose is to be.

[0007]

According to a first aspect of the present invention, in a vehicle driving force control device, a means for detecting an accelerator operation amount, a means for detecting a vehicle speed, a means for detecting a vehicle acceleration, Means for setting a normal target driving force according to the accelerator operation amount and the vehicle speed, means for calculating the driving force of the vehicle, means for setting the reference running resistance based on the vehicle speed, and means for calculating the acceleration resistance based on the vehicle acceleration Means for calculating an increase in running resistance by subtracting a reference running resistance and an acceleration running resistance from the vehicle driving force; means for calculating a driving force correction amount based on the increased running resistance; and Means for calculating a corrected target driving force by adding an amount to the normal target driving force, and means for controlling the vehicle driving force to be the corrected target driving force, wherein the means for calculating the driving force of the vehicle is provided. , Estimated The actual engine torque is estimated by correcting the engine torque, it is characterized in that calculating the driving force of the vehicle based on the actual engine torque this estimation.

A second invention is characterized in that, in the first invention, the means for calculating the driving force of the vehicle estimates the actual engine torque by performing a dead time process and a first-order lag process on the estimated steady-state engine torque. It is assumed that.

A third invention according to the second invention, further comprising means for detecting an air-fuel ratio of the engine, wherein the means for calculating the driving force of the vehicle comprises the dead time processing in accordance with the detected air-fuel ratio. Alternatively, parameters of the first-order lag processing are changed.

In a fourth aspect based on the second or third aspect, the apparatus further comprises means for detecting an engine speed.
The means for calculating the driving force of the vehicle changes parameters of the dead time processing or the first-order lag processing according to the detected engine speed.

In a fifth aspect based on the first to fourth aspects, the means for calculating the driving force correction amount calculates the driving force correction amount as 30% to 70% of the increase in the running resistance. It is characterized by the following.

[0012]

According to the first aspect, the actual engine torque is estimated in consideration of the delay in the rise of the engine torque, and the amount of increase in the running resistance is calculated based on the actual engine torque. As a result, the calculation error of the amount of increase in the running resistance is reduced, so that unnecessary driving force correction is performed due to the calculation error, thereby preventing the vehicle from excessively accelerating and giving the driver a sense of discomfort such as a rush. it can.

Although there is a delay between the time when the intake air is measured and the flow into the cylinder and the time after the fuel injection is performed and the combustion pressure rises, according to the second invention, the estimated steady-state engine torque Since the actual engine torque is estimated by performing the dead time processing and the first-order lag processing on the actual engine torque, the actual engine torque can be accurately estimated.

When the engine immediately before acceleration is performing lean combustion or stratified combustion, the torque response of the engine immediately after acceleration is lower than when the engine is burning at the stoichiometric air-fuel ratio. According to the present invention, since the parameter for estimating the actual engine torque is changed according to the air-fuel ratio, the actual engine torque can be accurately estimated regardless of the combustion state of the engine.

The higher the engine speed immediately before the acceleration is, the shorter the delay time from the fuel injection to the rise of the combustion pressure is. Thus, the torque response of the engine immediately after the acceleration is better. According to the method described above, since the parameter used when estimating the actual engine torque is changed in accordance with the engine speed, the actual engine torque can be accurately estimated regardless of the engine speed.

In addition, when the driver can visually confirm the increase in running resistance, such as on an uphill road, the driver often steps on the accelerator to increase the acceleration by himself / herself to correct acceleration for some of the increase in running resistance. According to the fifth aspect, the driving force correction amount is set to be smaller than the actual increase in the traveling resistance.
It is possible to prevent the vehicle from accelerating too much and giving the driver an uncomfortable feeling, and to obtain a natural feeling of acceleration.

[0017]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a schematic configuration of a vehicle provided with a vehicle driving force control device according to the present invention.

This vehicle is provided with an engine 1, a continuously variable transmission 2 and a controller 3 for controlling them collectively. The output of the engine 1 is transmitted to driving wheels via the transmission 2.

An electronically controlled throttle valve, which is opened and closed by a motor or the like, is interposed in the intake passage of the engine 1. The amount of intake air of the engine is adjusted by the degree of opening of the throttle valve to control the output torque of the engine 1. Is done. As the transmission 2, a belt-type continuously variable transmission or a toroidal-type continuously variable transmission is used because of its high degree of freedom in setting the gear ratio. However, a conventional planetary gear and a clutch member are used. A step transmission can also be used.

The engine 1 has a crank angle sensor 4 for detecting the engine speed, a throttle opening sensor 5 for detecting the opening of the throttle valve, and the like. Input shaft speed sensor 6 and output shaft speed sensor 7 for detecting
These detection signals are input to the controller 3.
In addition, the vehicle is provided with an accelerator operation amount sensor 8 for detecting an operation amount of an accelerator pedal, an acceleration sensor 9 for detecting vehicle acceleration, and the like, and their detection signals are also input to the controller 3.

The controller 3 includes a microprocessor,
The operating state of the vehicle is determined based on various signals input thereto, and the fuel injection amount of the engine 1, the ignition timing, the intake air amount, the speed ratio of the transmission 2 (input / output shaft speed ratio), etc. Control.

Specifically, when traveling on a flat road, the controller 3 sets a normal target driving force based on the detected accelerator operation amount and vehicle speed, and sets the engine 1 and the transmission so that the normal target driving force is realized. 2 under the driving conditions where the running resistance received by the vehicle, such as when traveling uphill, increases.
The normal target driving force is corrected according to the increase amount of the running resistance, and the driving force increase correction is performed so that the driver does not feel insufficient acceleration.

Hereinafter, the driving force control performed by the controller 3 will be described in detail.

FIG. 2 is a block diagram showing a configuration of a portion related to driving force control of the controller 3 (hereinafter, referred to as a "driving force control section"). As shown in this figure, the driving force control unit is roughly divided into a normal target driving force setting unit B10,
Running resistance increase amount calculation unit B20, driving force correction amount calculation unit B3
0, a corrected target driving force calculation unit B40, a target engine torque setting unit B50, and a target gear ratio setting unit B60.

To explain each of these elements, first,
Normally, the target driving force setting unit B10 calculates the vehicle speed VSP [m / s] obtained from the accelerator operation amount APO detected by the accelerator operation amount sensor 8 and the output shaft rotation speed of the transmission 2 detected by the output shaft rotation speed sensor 7. Based on the above, a normal target driving force tTd # n [N] required when traveling on a flat road at a constant vehicle speed is set with reference to a predetermined map, and is set to the corrected target driving force calculation unit B40. Output.

The running resistance increase calculating section B20 includes a driving force calculating section B21, a reference running resistance setting section B22, and an acceleration resistance calculating section B23.

The driving force calculator B21 includes a steady engine torque estimator B24 and an actual engine torque estimator B25, and corrects the steady engine torque ENGTRQ # m [Nm] estimated based on the fuel injection amount TP and the engine speed NRPM. To estimate the actual engine torque ENGTRQ [Nm]
The driving force TRQOUT [Nm] (output shaft torque of the transmission 2) of the vehicle is calculated by multiplying by TIO.

Here, the actual engine torque estimating unit B25
As shown in FIG. 3, it is composed of a dead time element B26 and a first-order lag element B27.

When the estimated steady-state engine torque ENGTRQ # m is input, the dead time element B26 holds
steady engine torque ENGTR estimated before ng / Ts cycle
Q # m is output to the primary delay element 27 as ENGTRQ # T. The parameter Teng is a so-called dead time, and Ts is an execution cycle (for example, 10 msec) of the present control.

The first-order lag element B27 includes a dead time element 26
First-order lag processing is performed on ENGTRQ # T output from, and the actual engine torque ENGTRQ is estimated. Here, assuming that the first-order lag parameter is A, the actual engine torque ENGTRQ is calculated by the following equation: ENGTRQ = A × ENGTRQ # m-Teng / Ts + (1−A) × ENGTRQ-Teng / Ts-1 (1) Is done.

Here, ENGTRQ # m-Teng / Ts is the steady-state engine torque ENGTRQ # m, EN which is estimated before the Teng / Ts cycle.
GTRQ-Teng / Ts-1 indicates the actual engine torque before the Teng / Ts-1 cycle.

FIG. 4 shows a time series relationship between the estimated steady-state engine torque ENGTRQ # m and the actual engine torque ENGTRQ as shown in FIG.
RQ starts to change with a delay of Teng with respect to the estimated steady-state engine torque Teng. Also, the actual engine torque ENGTRQ
Follows the estimated steady-state engine torque Teng with a first-order lag, but by setting a large value to the first-order lag parameter A, the time until the actual engine torque ENGTRQ matches the estimated steady-state engine torque ENGTRQ # m Is shortened.

Here, the dead time parameter Teng and the primary delay parameter A are changed according to the air-fuel ratio ABYF immediately before the acceleration of the engine 1 as shown in FIGS.

At the time of so-called lean combustion and stratified combustion, in which the air-fuel ratio ABYF is large, the torque response of the engine (the response of the actual engine torque to the estimated steady-state engine torque) is higher than when the combustion is performed at the stoichiometric air-fuel ratio. ) Becomes slightly dull, so that the dead time parameter Teng is set larger than at the stoichiometric air-fuel ratio, and the first-order lag parameter A is set smaller than at the stoichiometric air-fuel ratio.

Further, even when the air-fuel ratio ABYF is small, that is, on the so-called rich side, the torque response of the engine becomes dull. In this case, too, the dead time parameter Teng is set to be larger than that at the time of the stoichiometric air-fuel ratio, and the primary delay parameter A Is set smaller than the stoichiometric air-fuel ratio.

As described above, the time parameter Teng and the first-order lag parameter A are set to the air-fuel ratio ABYF immediately before the acceleration of the engine 1.
Thus, the actual engine torque ENGTRQ can be accurately estimated even if the combustion state of the engine 1 changes.

Returning to FIG. 2, the remaining elements of the driving force control unit of the controller 3 will be described. The reference running resistance setting unit B22 determines a predetermined table based on the vehicle speed VSP calculated from the output shaft speed of the transmission 2. And set the reference running resistance torque RLDTRQ [Nm] with reference to. This reference running resistance torque
RLDTRQ is set to a large value as the vehicle speed VSP increases.

The acceleration resistance calculating section B23 calculates the vehicle acceleration GDATA [m / s ² ] detected by the acceleration sensor 9 as follows:
Vehicle weight WV [kg], tire radius rTIRE [m] and final reduction ratio ZRAT
Calculate the acceleration resistance torque GTRQ [Nm] by multiplying by IO. That is, the acceleration resistance torque GTRQ is calculated by the following equation: GTRQ = GDATA × WV × rTIRE × ZRATIO (2)

The running resistance increase amount calculating section B20 calculates
The driving resistance is increased by subtracting the reference driving resistance torque RLDTRQ set by the reference driving resistance setting section B22 and the acceleration resistance torque GTRQ calculated by the acceleration resistance calculating section B23 from the vehicle driving force TRQOUT calculated by the driving force calculation section B21. Amount RESTRQ [Nm]
And outputs it to the driving force correction amount calculation unit B30. The running resistance increase amount RESTRQ is calculated by the following equation: RESTRQ = TRQOUT- (RLDTRQ + GTRQ) (3)

The driving force correction amount calculating unit B30 calculates the driving force correction amount ADDFD [N] with reference to the table shown in FIG. 7 based on the running resistance increase amount RESTRQ, and calculates the corrected target driving force calculating unit B40. Output to

Referring to the table shown in FIG.
This is the driving force correction amount ADDF for the running resistance increase amount RESTRQ.
This shows how D is calculated, and the ratio (slope) of the driving force correction amount ADDFD to the traveling resistance increase amount RESTRQ changes according to the magnitude of the traveling resistance increase amount RESTRQ.

For example, the running resistance increase amount RESTQ is equal to a predetermined value RE.
In the case of S # TLEV1 or less, the driving force correction amount ADDFD becomes zero. Here, the predetermined value RES # TLEV1 is set to, for example, a value in the range of 10 to 30 [Nm] which is a value corresponding to a gradient of 2%.

The running resistance increase amount RESTRQ is set to a predetermined value RES #
In the case of TLEV1 or more and the predetermined value RES # TLEV2 or less, the driving force correction amount AD
DFD is as follows: ADDFD = RESTRQ × 0.5 / rTIRE (4) The reason for dividing by the tire radius rTIRE is to convert the unit from the torque [Nm] to the driving force [N]. Here, 50% of the running resistance increase RESTRQ is set as the driving force correction amount ADDFD.

The running resistance increase amount RESTRQ is equal to a predetermined value RES #
In the case of TLEV2 or more, the driving force correction amount ADDFD is limited to the predetermined value ADDFDLM regardless of the magnitude of the running resistance increase amount. The predetermined value RES # TLEV2 is set, for example, so that an acceleration of 0.07 G or more is not generated in the vehicle body by the driving force correction amount ADDFD,
Here, a value corresponding to a 14% gradient is set.

The corrected target driving force calculating section B40 calculates the corrected target driving force tTd by adding the driving force correction amount ADDFD to the normal target driving force tTd # n. The corrected target driving force tTd is
It is calculated by the following equation: tTd = tTd # n + ADDFD (5) Then, the correction driving force calculation unit B40
Outputs the corrected target driving force tTd to the target engine torque setting unit B50 and the target gear ratio setting unit B60, respectively.

The target engine torque setting section B50 calculates the target engine torque tTe [N] by dividing the corrected target driving force tTd by the gear ratio RATIO, and outputs it to the engine 1. Further, the target gear ratio setting unit B60 outputs the corrected target driving force tTd [N].
A target speed ratio tRATIO is determined by referring to a predetermined map based on the vehicle speed VSP [m / s] and the speed is output to the transmission 2. In addition,
Here, the target speed ratio tRATIO is obtained, but the target input speed may be obtained instead of the target speed ratio tRATIO.

The configuration of the driving force control unit of the controller 3 has been described above. Next, the operation of the driving force control unit will be described with reference to the flowchart shown in FIG.

First, the controller 3 controls the sensor group 4
The accelerator operation amount APO, vehicle speed VSP, vehicle acceleration GDATA, gear ratio RATIO, fuel injection amount TP, and engine speed NRPM are read from the detection results of Nos. 9 to 9 or the calculation results of a control routine (not shown) (step S11).

Then, based on the accelerator operation amount APO and the vehicle speed VSP, a normal target driving force tTd # n required to travel on a flat road at a constant vehicle speed is set (step S12), and the engine speed NRPM and the combustion injection amount TP are set. Steady engine torque ENGT based on
RQ # m is estimated (step S13).

Further, the estimated steady-state engine torque
The actual engine torque ENGTRQ is estimated by performing predetermined dead time processing and first-order delay processing on ENGTRQ # m (step S1).
4). The response delay of the actual engine torque due to the delay between the time when the intake air is measured and flowing into the cylinder and the delay between the time when fuel injection is performed and the time when the combustion pressure rises is almost characterized by dead time and first-order delay. By performing the dead time process and the first-order lag process on the estimated steady engine torque ENGTRQ # m to estimate the actual engine torque ENGTRQ, it is possible to accurately estimate the actual engine torque.

Further, for the dead time parameter Teng and the primary delay parameter A used in the dead time processing and the first-order delay processing, refer to the tables shown in FIGS. 5 and 6 according to the air-fuel ratio of the engine 1 immediately before acceleration. Therefore, the actual engine torque can be accurately estimated regardless of the combustion state of the engine 1. The dead time parameter Teng and the first-order lag parameter A may be determined according to the engine speed NRPM as described later.

After the actual engine torque ENGTRQ is estimated in this way, the vehicle driving force TRQOUT (the output shaft torque of the transmission 2) is calculated by multiplying the actual engine torque ENGTRQ by the speed ratio RATIO of the transmission 2 (step S15).

The controller 3 sets a reference running resistance RLDTRG with reference to a predetermined table based on the vehicle speed VSP (step S16), and calculates an acceleration resistance GTRQ based on the vehicle acceleration GDATA (step S17).

After calculating the output shaft torque TRQOUT, the reference running resistance RLDTRQ, and the acceleration resistance GTRQ of the transmission 2, the reference running resistance RLDTRQ and the acceleration resistance GTRQ are subtracted from the output shaft torque TRQOUT to calculate the increase amount RESTRQ of the running resistance. (Step 1
8).

As described above, the value obtained by subtracting the reference running resistance RLDTRQ and the acceleration resistance GTRQ from the output shaft torque TRQOUT is used as the running resistance increase amount RESTRQ, so that the gradient resistance can be reduced even when the transmission efficiency of the transmission 2 is deteriorated. When it increases, the acceleration force correction can be performed similarly.

That is, when the torque transmission efficiency of the transmission 2 is deteriorated, the actual output shaft torque becomes smaller than the calculated output shaft torque TRQOUT, the acceleration becomes slow, and the acceleration resistance GTRQ becomes small. Therefore, the reference running resistance RLDTRQ is calculated to be larger than when the transmission efficiency is not deteriorated, and when the transmission efficiency is deteriorated, the increase in the driving force is corrected in the same manner as when the gradient resistance is increased.

After calculating the running resistance increase amount RESTRQ, a driving force correction amount ADDFD is calculated with reference to a table as shown in FIG. 7 (step S19). The driving force correction amount ADDFD is calculated in accordance with the running resistance increase amount RESTRQ. As described above, when the running resistance increase amount RESTRQ is equal to or less than the predetermined value RES # TLEV1, the driving force correction amount ADDFD becomes zero. Is set to, there is an error when calculating the amount of increase in running resistance, or the driving force correction is performed only by a slight change in running resistance due to a slight head wind or a gentle gradient, and the driver It is possible to prevent the user from feeling uncomfortable.

The running resistance increase amount RESTRQ is equal to a predetermined value RES #
In the case of TLEV1 or more and a predetermined value RES # TLEV2 or less, 50% of the running resistance increase amount RESTRRQ is calculated as the driving force correction amount ADDFD. As a result, when the driver can visually confirm the increase in the running resistance, such as on an uphill road, 50% of the increased running resistance is required.
As for the driver, the driver himself / herself increases the amount of depression of the accelerator to correct the driving force, and a natural acceleration feeling without discomfort can be obtained.

The value of 50% varies depending on the characteristics of the vehicle to be designed. If the value is set to a value between 30% and 70%, the driving force can be corrected without giving the driver an uncomfortable feeling.

The running resistance increase amount RESTRQ is equal to a predetermined value RES #
In the case of TLEV2 or more, the driving force correction amount ADDFD is a constant value AD
Limited to DFDLM. As a result, even if the running resistance increase RESTRQ calculated due to, for example, a calculation error of the controller 3 becomes abnormally large, acceleration correction is not performed using the increased value as it is, and the driving force correction amount AD
Since the maximum acceleration by DFD is suppressed to about 0.07G, it is possible to prevent the vehicle from accelerating rapidly.

The driving force correction amount ADDFD is always set continuously with respect to the change in the running resistance increase amount RESTRQ, and the driving force correction amount ADDFD does not change stepwise.
Thus, for example, even when the gradient of the uphill road changes slowly, the driving force correction amount can be adjusted for the change in running resistance.
The ADDFD can be changed continuously, and it is possible to prevent the occurrence of a shock due to a step in the driving force.

After calculating the driving force correction amount ADDFD in this way, the controller 3 calculates the target driving force tTd by adding the driving force correction amount ADDFD to the normal target driving force tTd # n calculated in step S12. (Step S20). Then, in order to realize the target driving force tTd, a target engine torque tTe and a target gear ratio tRATIO are calculated and output to the engine 1 and the transmission 2, respectively (step S21, step S22).

The engine 1 which has received the command from the controller 3 controls the throttle opening, the fuel injection amount, the ignition timing, etc. in order to achieve the target engine torque tTe, and the transmission 2 realizes the target gear ratio tRATIO. The hydraulic circuit and the like for speed change control are controlled as needed.

When the vehicle is traveling on a flat road, if the acceleration resistance is zero, the travel resistance increase amount RESTQ becomes zero,
Since the driving force correction amount ADDFD is also zero, step S12
The engine 1 and the transmission 2 are controlled based on the normal target driving force tTd # n calculated in.

As described above, in this embodiment, when the running resistance changes, the magnitude of the driving force is set to the running resistance increase amount RESTRQ so that the driver can obtain a satisfactory feeling of acceleration.
, It is possible to always obtain a feeling of acceleration without discomfort.

In particular, when the running resistance increase amount RESTRQ is calculated, the estimated steady-state engine torque ENGTRQ # m is not used for the calculation as it is, but the actual engine torque ENGTRQ estimated by performing a dead time process and a first-order lag process. Is used, it is possible to accurately calculate the running resistance increase amount RESTRQ.

As a result, when the engine torque fluctuates, unnecessary driving force correction is performed due to the calculation error of the running resistance increase amount RESTRQ, and the vehicle is over-accelerated or gives the driver a feeling of rushing. Can be prevented and a feeling of acceleration without a sense of incongruity can always be obtained.

FIG. 9 shows a case where the output torque of the engine changes in a situation where the amount of increase in running resistance does not change.

When the present invention is not applied, that is, when the estimated steady-state engine torque ENGTRQ # m is used as it is in the calculation of the running resistance increase amount RESTRQ, the delay in the rise of the actual engine torque is regarded as an increase in the running resistance. However, it is considered that the running resistance has increased even though the actual running resistance has not changed. As a result, unnecessary driving force correction is performed, which gives the driver an uncomfortable feeling such as excessive acceleration of the vehicle.

On the other hand, when the present invention is applied, that is, the actual engine torque estimated by performing the dead time processing and the first-order lag processing on the estimated steady-state engine torque ENGTRQ # m
When ENGTRQ is used to calculate the travel resistance increase RESTRQ,
The delay in the rise of the engine torque is not regarded as an increase in the running resistance, and the above problem does not occur.

In the above embodiment, the dead time parameter Teng and the first-order lag parameter A are changed according to the air-fuel ratio ABYF. However, since the combustion state of the engine 1 also changes according to the engine speed NRPM immediately before acceleration, The dead time parameter Teng and the primary delay parameter A may be changed according to the engine speed NRPM immediately before acceleration.

In this case, the dead time parameter Teng and the primary delay parameter A are set with reference to tables as shown in FIGS.

According to this, when the engine speed NRPM is high, the combustion time interval becomes small, and the time lag during which the torque of the engine 1 actually rises after fuel injection becomes small. A small value is set for the dead time parameter Teng.

The lower the engine speed NRPM, the greater the increase in engine speed during acceleration, the greater the loss of inertia torque of the engine 1 due to the increase in engine speed, and the rise in engine output torque. Since the response becomes slow, the lower the engine speed NRPM, the smaller the first-order lag parameter A is set.

By changing the primary delay parameter A and the dead time parameter Teng according to the engine speed NRPM in this manner, even if the engine speed NRPM changes,
The actual engine torque ENGTRQ can be accurately estimated, and the calculation accuracy of the driving force increase amount RESTRQ is also improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a vehicle provided with a vehicle driving force control device according to the present invention.

FIG. 2 is a block diagram illustrating a configuration of a driving force control unit of the controller.

FIG. 3 is a block diagram showing a configuration of an actual engine torque estimating unit.

FIG. 4 is a diagram showing a relationship between estimated steady-state engine torque and actual engine torque.

FIG. 5 is a table used when setting a dead time parameter according to an air-fuel ratio.

FIG. 6 is a table used when setting a first-order lag parameter according to an air-fuel ratio.

FIG. 7 is a table used in a driving force correction amount calculation unit.

FIG. 8 is a flowchart showing an operation content of a driving force control unit.

FIG. 9 is a timing chart showing the effect of the present invention.

FIG. 10 is a table used when setting a dead time parameter according to an engine speed;

FIG. 11 is a table used when setting a first-order lag parameter according to an engine speed;

[Explanation of symbols]

 Reference Signs List 1 engine 2 transmission 3 controller 4 crank angle sensor 5 throttle opening sensor 6 input shaft speed sensor 7 output shaft speed sensor 8 accelerator operation amount sensor 9 acceleration sensor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02D 43/00 301 F02D 43/00 301H 301K 301B (72) Inventor Masayuki Yasuoka 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa-ken Address F-term in Nissan Motor Co., Ltd. (reference) 3D041 AA32 AA66 AB01 AC01 AC14 AD02 AD09 AD10 AD31 AD47 AD50 AD51 AE03 AE31 AF00 AF09 3G084 BA05 BA13 BA17 DA05 DA15 EB08 EB12 EC04 FA00 FA05 FA10 3G301 HA01 HA16 JA03 JA03 JA01 KB03 NE23 PA01A PA01Z PA11A PA11Z PB03A PB03Z PE01Z PE06A PE06Z PF08A PF08Z

Claims (5)

[Claims] A means for detecting an accelerator operation amount; a means for detecting vehicle speed; a means for detecting vehicle acceleration; a means for setting a normal target driving force in accordance with the detected accelerator operation amount and vehicle speed; Means for calculating the driving force of the vehicle; means for setting the reference running resistance based on the vehicle speed; means for calculating the acceleration resistance based on the vehicle acceleration; and running while subtracting the reference running resistance and the acceleration running resistance from the vehicle driving force. Means for calculating the amount of increase in the resistance; means for calculating the amount of driving force correction based on the amount of increase in the running resistance; and calculating the corrected target driving force by adding the amount of driving force correction to the normal target driving force. Means, and means for controlling the vehicle driving force so as to be a corrected target driving force, wherein the means for calculating the driving force of the vehicle estimates the actual engine torque by correcting the estimated steady-state engine torque, Vehicle driving force control apparatus characterized by calculating a driving force of the vehicle based on the actual engine torque estimation. 2. The vehicle according to claim 1, wherein the means for calculating the driving force of the vehicle estimates a real engine torque by performing a dead time process and a first-order lag process on the estimated steady-state engine torque. Driving force control device. 3. The vehicle according to claim 2, further comprising: means for detecting an air-fuel ratio of the engine, wherein the means for calculating the driving force of the vehicle changes parameters of the dead time processing or the first-order lag processing according to the detected air-fuel ratio. The vehicle driving force control device according to claim 2, wherein: 4. The vehicle further comprises means for detecting an engine speed, wherein the means for calculating the driving force of the vehicle changes parameters of the dead time processing or the first-order lag processing according to the detected engine speed. The vehicle driving force control device according to claim 2 or 3, wherein: 5. The method according to claim 1, wherein the means for calculating the driving force correction amount calculates a driving force correction amount of 30% to 70% of the increase in the running resistance. 4. The vehicle driving force control device according to claim 1.