JP3460528B2 - Vehicle driving force control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is based on controlling the wheel driving force of a vehicle equipped with a continuously variable transmission in such a manner that the fuel consumption of the engine is minimized, while at the same time sacrificing the fuel consumption. The present invention relates to a device for controlling a wheel driving force in a mode in which an accelerator response has a margin as necessary while minimizing the above.

[0002]

2. Description of the Related Art In a continuously variable transmission represented by a V-belt type continuously variable transmission and a toroidal type continuously variable transmission, a target gear ratio is generally obtained from an engine required load and a vehicle speed. Shift control is performed so that the target gear ratio is achieved.

Therefore, at the time of acceleration in which the driver depresses the accelerator pedal to increase the engine load demand, the target gear ratio is changed to a larger value (the gear ratio on the low speed side), and the continuously variable transmission is greatly changed. Downshift is performed to the target gear ratio that was set, and conversely, during low load operation in which the driver releases the accelerator pedal to reduce the required engine load,
The target gear ratio is changed to a smaller value (the gear ratio on the higher speed side), and the continuously variable transmission is upshifted to the reduced target gear ratio.

On the other hand, as a technique for obtaining the required driving force of a vehicle, there is a technique described in, for example, Japanese Patent Application Laid-Open No. 7-172217. This technology calculates the target driving force of the vehicle from the vehicle speed and the accelerator pedal depression amount,
To this, a running resistance amount that can be estimated from the vehicle speed is added to obtain a required driving force to be transmitted to the wheels.

[0005]

By the way, in the above-described shift control of a general continuously variable transmission, the required driving force obtained by the technique according to the above-mentioned literature cannot be accurately realized, and much less. In any case, it is impossible to realize the required driving force obtained in such a manner as to minimize the fuel consumption of the engine only by the shift control of the transmission. Even if the driving force can be controlled via the engine and the continuously variable transmission in such a manner that the fuel efficiency of the engine becomes the minimum, according to the control, the responsiveness of the wheel driving force to the depression of the accelerator pedal, that is, Since the vehicle is being driven in a state where there is no room in the accelerator response, the driver will be dissatisfied with the power performance under the condition that the acceleration performance should be emphasized.

Therefore, the vehicle and the 雖 which are controlled so that the fuel consumption of the engine is the lowest, allow the accelerator response to have a margin as necessary, and the driving force that can exhibit the required acceleration performance. Control should also be possible. However, in the past, in addition to the driving force control that minimizes fuel consumption, the technical idea is to enable a driving force control with a margin in accelerator response and a margin while reducing the sacrifice of fuel consumption. Did not exist.

According to a first aspect of the present invention, by the engine output control and the shift control of the continuously variable transmission, the former driving force control that emphasizes fuel consumption and the latter driving force that has a margin that emphasizes accelerator response are provided. An object of the present invention is to propose a vehicle driving force control device that can achieve both control and control.

According to a second aspect of the present invention, the simplest combination of the target engine speed and the target engine output, which should be obtained in the first aspect of the invention, is to generate the required horsepower in a mode in which the fuel consumption of the engine is minimized. The purpose is to be able to obtain.

A third aspect of the present invention is to propose a simple method for obtaining a corrected target engine output from the target engine output obtained in the first aspect or the second aspect.

A fourth aspect of the present invention is to propose another method for obtaining the target engine speed and the corrected target engine output in the first aspect.

According to a fifth aspect of the present invention, a method different from the first aspect of the present invention is provided so that the driving force control with an emphasis on fuel consumption and the driving force control with a margin with an emphasis on accelerator response can both be achieved. It is an object of the present invention to propose a vehicle driving force control device.

According to a sixth aspect of the present invention, a simple driving force control device is proposed which is capable of achieving almost the same objects as those of the first and fifth aspects by a method different from those of the first and fifth aspects. The purpose is to do.

It is an object of a seventh aspect of the present invention to propose a suitable construction method of data used when determining the shift control amount of the continuously variable transmission.

An eighth object of the present invention is to make the data used for obtaining the shift control amount of the continuously variable transmission more practically suitable.

It is an object of a ninth aspect of the present invention to propose a method of determining a marginal driving force for driving force control with a margin of emphasis on accelerator response in each of the above inventions.

[0016]

For these purposes, the vehicle driving force control apparatus according to the first aspect of the invention controls the throttle opening toward a target value that can be corrected by factors other than accelerator pedal operation. In a vehicle equipped with a power train that combines an engine and a continuously variable transmission, the required axle drive force determined by the operating conditions and running conditions of the vehicle, and the accelerator response margin that is also determined based on the operating conditions and running conditions The target axle drive force obtained by adding the extra drive force for the required amount is calculated as a combination of the target engine speed and the target engine output for generating the minimum fuel consumption, and the target engine output is corrected by the extra drive force. Then, the corrected target engine output is obtained, and the continuously variable transmission is subjected to gear shift control so that the transmission has a target input speed corresponding to the target engine speed. As well as, it is characterized in that it has a configuration for controlling the throttle opening so as to be the corrected target engine output.

The vehicle driving force control apparatus according to the second invention is
In the first aspect of the present invention, a required horsepower is obtained by multiplying the target axle driving force by an axle rotation speed, and a combination of an engine rotation speed and an engine output for generating the required horsepower with minimum fuel consumption is obtained from an engine characteristic diagram. Then, the engine speed and the engine output are set to the target engine speed and the target engine output, respectively.

The vehicle driving force control apparatus according to the third invention is
In the first invention or the second invention, the target engine is corrected by an engine output correction amount obtained by dividing the margin driving force by a wheel drive system target speed ratio which is a ratio of the transmission target input speed and the axle speed. It is characterized in that the output is subtracted to obtain the corrected target engine output.

A vehicle driving force control apparatus according to the fourth invention is
In the first aspect of the present invention, a required horsepower is obtained by multiplying the target axle driving force by an axle rotation speed, and only the engine speed of the engine speed and engine output for generating the required horsepower with minimum fuel consumption Obtained from the characteristic diagram, this engine speed is taken as the target engine speed, and the wheel drive system target speed ratio is expressed by the ratio of the axle speed to the transmission target input speed corresponding to this target engine speed. Is configured to obtain the corrected target engine output by dividing the required axle driving force.

The vehicle driving force control apparatus according to the fifth aspect of the present invention is
An engine whose throttle opening is controlled toward a target value that can be corrected by factors other than accelerator pedal operation,
In a vehicle equipped with a power train that is combined with a continuously variable transmission, the required driving force for the axle determined by the operating conditions and running conditions of the vehicle is added to the surplus driving force determined based on the operating conditions and running conditions. The target axle driving force obtained,
Based on the vehicle speed, the axle driving force, and the data indicating the relationship between the engine speed and the vehicle speed previously obtained based on the minimum fuel consumption line on the engine characteristic diagram, the target axle driving force can be calculated with the minimum fuel consumption. The target engine rotation speed to be generated is obtained, and the required axle drive force is divided by the wheel drive system target gear ratio represented by the ratio of the axle rotation speed to the transmission target input rotation speed corresponding to this target engine rotation speed. As a result, a corrected target engine output reduced by the margin driving force is obtained, and the continuously variable transmission is shift-controlled so as to attain the transmission target input speed, and the corrected target engine output is obtained. It is characterized in that the throttle opening is controlled.

A vehicle driving force control apparatus according to the sixth invention is
An engine whose throttle opening is controlled toward a target value that can be corrected by factors other than accelerator pedal operation,
In a vehicle equipped with a power train that is combined with a continuously variable transmission, the required driving force for the axle determined by the operating conditions and running conditions of the vehicle is added to the surplus driving force determined based on the operating conditions and running conditions. The target axle driving force obtained,
Based on the vehicle speed, the axle driving force, and the data indicating the relationship between the engine speed and the vehicle speed previously obtained based on the minimum fuel consumption line on the engine characteristic diagram, the target axle driving force can be calculated with the minimum fuel consumption. The target engine speed to be generated is calculated to obtain the required engine output by dividing the supply axle driving force by the wheel drive system actual speed ratio represented by the ratio of the transmission input speed to the axle speed. Shift control of the continuously variable transmission is performed so as to achieve the target input speed, and
It is characterized in that the throttle opening is controlled so as to obtain the required engine output.

The vehicle driving force control apparatus according to the seventh invention is
The fifth or sixth invention is characterized in that the data representing the relationship between the vehicle speed, the axle driving force, and the engine speed is obtained as follows. That is, the individual points on the minimum fuel consumption line are transferred onto two-dimensional coordinates in which the engine speed is replaced by the vehicle speed and the engine output is replaced by the axle driving force by a coefficient related to the gear ratio, and the points at which the engine speed is equal are transferred. Try to find it in advance as the line connecting

The vehicle driving force control apparatus according to the eighth aspect of the present invention is
The fifth or sixth invention is characterized in that the data representing the relationship between the vehicle speed, the axle driving force, and the engine speed is obtained as follows. That is, each point on the minimum fuel consumption line is replaced with the engine speed by the coefficient relating to the gear ratio, the engine speed is replaced by the vehicle speed, and the engine output is replaced by the axle driving force. Try to ask for it.

The vehicle driving force control apparatus according to the ninth aspect of the present invention is
In any one of the first to eighth inventions, the surplus driving force is at least one of an accelerator pedal depression amount, a depression speed, a depression frequency, a vehicle speed level, a change rate, a change frequency, a road condition, and a driver's preference. It is characterized in that it is configured so as to be determined automatically or manually according to.

[0025]

According to the first aspect of the invention, the engine controls the throttle opening toward a target value that can be corrected by factors other than the accelerator pedal operation, and the output from the engine is continuously variable according to the throttle opening. The speed is changed by the transmission and becomes the output of the power train.

In the first aspect of the invention, in particular, the required axle driving force determined by the driving state and running conditions of the vehicle is added to the margin driving force for the accelerator response margin, which is also determined based on the driving state and running conditions. Determine the combination of the target engine speed and target engine output to generate the target axle drive force with the minimum fuel consumption, and first shift the continuously variable transmission so that the transmission has a target input speed corresponding to the target engine speed. Control, and further, the throttle opening is controlled so as to obtain the corrected target engine output obtained by correcting the target engine output by lowering it by the margin driving force.
On the other hand, the transmission target input rotation speed is increased by the addition of the surplus driving force to set the continuously variable transmission to the low speed side gear ratio, and accordingly, the driving performance with the required margin in the accelerator response. The driving force control with emphasis is realized, and on the other hand, the throttle opening is reduced by the corrected target engine output by the amount that the transmission input speed is increased by the above shift control, which adversely affects the minimum fuel consumption. It is possible to realize the importance of the driving performance while suppressing the above to a minimum.

While the surplus driving force is not required, the driving force control is performed so that the required axle driving force is generated with the minimum fuel consumption, so that the driving force control emphasizing the fuel consumption can be realized. Moreover, such switching of the driving force control mode can be achieved by a simple logic of whether or not the extra driving force is added to the required axle driving force, which is very advantageous in terms of cost.

As described above, in the first aspect of the present invention, the minimum fuel consumption is greatly sacrificed when the required axle driving force is normally generated with the minimum fuel consumption, but the importance of the driving performance with a sufficient accelerator response is provided if necessary. It can be realized in a non-existent manner.

In the second invention, when the target engine speed and the target engine output in the first invention are obtained, the required horsepower is obtained by multiplying the required axle driving force and the axle rotation speed, and the required horsepower is obtained with the minimum fuel consumption. The combination of the target engine speed and the target engine output is most easily obtained because the combination of the engine speed and the engine output to be generated is obtained from the engine characteristic diagram and these are used as the target engine speed and the target engine output. This is advantageous because it can be obtained.

In the third invention, the first invention or the second invention
The target engine output obtained by the invention is corrected by subtracting the engine output correction amount obtained by dividing the margin driving force by the wheel drive system target gear ratio, which is the ratio of the transmission target input speed and the axle speed. Since the corrected target engine output is obtained, the corrected target engine output can be easily obtained from the target engine output, which is very advantageous.

When obtaining the target engine speed and the corrected target engine output in the first aspect of the invention, the required horsepower is obtained by multiplying the target axle driving force and the axle speed as in the fourth aspect of the invention, and the required horsepower is calculated. Of the engine speed and the engine output for generating the minimum fuel consumption, only the engine speed is obtained from the engine characteristic diagram, and this engine speed is set as the target engine speed, and the shift corresponding to the target engine speed is performed. The corrected target engine output can be obtained by dividing the required axle drive force by the wheel drive system target gear ratio represented by the ratio of the axle rotation speed to the machine target input rotation speed. In this case, since only the target engine speed is obtained by searching and the corrected target engine output is obtained by calculation, the frequency of searching can be reduced.

According to the fifth aspect of the invention, the target axle driving force obtained by adding the required axle driving force determined based on the driving state and the traveling condition of the vehicle to the required driving force similarly determined based on the driving state and the traveling condition, and Generates the target axle drive force with the minimum fuel consumption based on the data that shows the relationship between the vehicle speed, the axle drive force, and the engine speed, which was previously obtained from the vehicle speed based on the minimum fuel consumption line on the engine characteristic diagram. A target engine rotation speed is calculated to control the continuously variable transmission so that the transmission target input rotation speed corresponds to the target engine rotation speed. Further, the required target axle drive force is divided by the target drive ratio of the wheel drive system represented by the ratio of the axle revolution speed to the target transmission revolution speed, and the corrected target engine is corrected to be reduced by the margin drive force. The output is determined and the throttle opening is controlled so as to obtain this corrected target engine output.

Therefore, also in the fifth aspect of the invention, the transmission target input speed is increased by the addition of the surplus driving force to bring the continuously variable transmission to the low speed side gear ratio, and the accelerator response corresponds to the required amount. It is possible to realize the driving force control with an emphasis on driving performance with a margin. On the other hand, the throttle opening is reduced by the corrected target engine output by the amount that the transmission input speed is increased by the above-mentioned shift control, and the adverse effect on the minimum fuel consumption is suppressed to the minimum while the driving performance is reduced. Achieve the purpose of importance.

While the surplus driving force is not required, the driving force control is performed so that the required axle driving force is generated with the minimum fuel consumption, so that the driving force control emphasizing the fuel consumption can be realized. Moreover, such switching of the driving force control mode can be achieved by a simple logic of whether or not the extra driving force is added to the required axle driving force, which is very advantageous in terms of cost.

As described above, also in the fifth aspect of the invention, normally, while the required axle driving force is generated with the minimum fuel consumption, the importance of the driving performance with a margin in the accelerator response is sacrificed if necessary. It is possible to achieve the same object as in the first aspect of the invention that it is realized in a non-existing manner.

In the sixth aspect of the invention, the target axle driving force obtained by adding the required axle driving force determined by the driving state and the running condition of the vehicle to the margin driving force also determined based on the driving state and the running condition, and Generates the target axle drive force at the minimum fuel consumption based on the data that shows the relationship between the vehicle speed, the axle drive force, and the engine speed, which was previously obtained from the vehicle speed based on the minimum fuel consumption line on the engine characteristic diagram. The target engine rotation speed for this purpose is obtained, and the continuously variable transmission is shift-controlled so that the transmission target input rotation speed corresponds to this target engine rotation speed. Further, the required driving force is calculated by dividing the margin driving force by the actual driving ratio of the wheel drive system represented by the ratio of the rotation speed of the axle to the input rotation speed of the transmission, and the throttle opening is controlled so as to obtain the required driving power. To do.

Therefore, in the sixth aspect of the invention, on the other hand, the transmission target input rotation speed is increased by the addition of the surplus driving force to bring the continuously variable transmission to the low speed side gear ratio, and the accelerator response is accordingly increased. It is possible to achieve the same operational effect as that of the first and fifth inventions, in which the driving force control emphasizing the driving performance with the required margin can be realized. However, the required engine output uses the actual wheel drive system gear ratio instead of the target wheel drive system gear ratio in which the surplus driving force is taken into consideration in the calculation. It is not possible to correct the decrease by the increased amount, but with throttle opening control according to the required engine output, it is not possible to achieve the purpose of focusing on driving performance while suppressing the adverse effect on minimum fuel consumption to the minimum. No, but nonetheless, the objective can be achieved to some extent in practice.

While the extra drive force is not required, the drive force control is performed so that the required axle drive force is generated with the minimum fuel consumption, so that the drive force control with an emphasis on fuel consumption can be realized. And the same as the fifth invention.

In the seventh aspect of the invention, each point on the minimum fuel consumption line is transferred onto a two-dimensional coordinate system in which the engine speed is replaced by the vehicle speed and the engine output is replaced by the axle driving force by a coefficient relating to the gear ratio, and As a line connecting the points having the same engine speed, data representing the relationship between the vehicle speed, the axle driving force, and the engine speed in the fifth invention or the sixth invention is previously obtained. The accuracy of the target engine speed obtained based on the data can be made accurate according to the actual situation.

In the eighth aspect of the present invention, the engine speed is replaced by the vehicle speed and the engine output is replaced by the axle driving force at each point on the minimum fuel consumption line by the coefficient relating to the gear ratio, and the engine speed for each axle driving force is changed with respect to the engine speed. As the characteristic curve of the rotation speed, data representing the relationship between the vehicle speed, the axle driving force, and the engine rotation speed in the fifth invention or the sixth invention is obtained in advance, and the target obtained based on the data is obtained. The accuracy of the engine speed can be made accurate according to the actual situation, and the shift control map only changes the parameter from the conventional accelerator opening to the axle driving force. Even when a gear shift different from the above is performed, the objective can be achieved by directly following the conventional idea.

In determining the margin driving force for the accelerator response in each of the above inventions, as in the ninth invention,
It is useful to determine automatically or manually according to at least one of the amount of depression of the accelerator pedal, the depression speed, the depression frequency, the level of the vehicle speed, the change rate, the change frequency, the road condition, and the driver's preference.

[0042]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a power train of a vehicle equipped with a driving force control device according to an embodiment of the present invention and its control system. The power train is an engine 1
And continuously variable transmission 2. The engine 1 is provided with a throttle valve 5 which is not linked to an accelerator pedal 3 operated by a driver but is separated from the accelerator pedal 3 and whose opening degree is electronically controlled by a step motor 4. The throttle valve 5 is set to the target throttle opening TVO ^* by setting the rotational position corresponding to the degree (TVO ^* ) command so that the output of the engine 1 can be controlled by factors other than accelerator pedal operation. .

The continuously variable transmission 2 is a well-known V-belt type continuously variable transmission, and includes a primary pulley 7 drivingly connected to an output shaft of the engine 1 through a torque converter 6, and a secondary pulley 8 aligned with the primary pulley 7. , And a V-belt 9 hung between these pulleys. Then, the differential gear device 11 is drivingly connected to the secondary pulley 8 via the final drive gear set 10, and the wheels (not shown) are rotationally driven by these.

In order to change the speed of the continuously variable transmission 2, one of the flanges forming the V groove of the primary pulley 7 and the secondary pulley 8 is brought relatively close to the other fixed flange. To reduce the width of the V-groove and widen the width of the V-groove by separating them so that both movable flanges have a primary pulley pressure P _pri and a secondary pulley pressure from the hydraulic actuator 12 that responds to the target gear ratio (i ^* ) command. By displacing the continuously variable transmission 2 to a position corresponding to P _sec , the continuously variable transmission 2 can be continuously variable so that the actual gear ratio matches the target gear ratio i ^* .

The target throttle opening TVO ^* and the target gear ratio i ^* are calculated by the controller 13 respectively. Because of this, the controller 13
Depressed position of accelerator pedal 3 (accelerator opening) AP
A signal from an accelerator opening sensor 14 that detects S and a throttle opening sensor 1 that detects a throttle opening TVO
6, a signal from the primary pulley rotation sensor 17 that detects the rotation speed (primary rotation speed) N _pri of the primary pulley 7, and a secondary pulley that detects the rotation speed (secondary rotation speed) N _sec of the secondary pulley 8. The signal from the rotation sensor 18 and the signal from the vehicle speed sensor 19 that detects the vehicle speed VSP are input.

Based on these input information, the controller 13 performs the shift control of the continuously variable transmission 2 and the throttle opening control of the engine 1 as follows, as shown in the functional block diagram of FIG. In the required axle driving force calculation unit 21,
Based on the accelerator opening APS detected by the sensor 14 and the vehicle speed VSP detected by the sensor 19, for example, by the method described in the above-mentioned document, the required minimum required axle driving force T _S according to the driving state and running conditions of the vehicle Ask for.

The accelerator response margin driving force calculation unit 27
The vehicle speed VSP and the accelerator opening APS are respectively input, and, for example, in the stepped automatic transmission, the same concept as when switching between the fuel consumption-oriented normal pattern and the power performance-oriented power pattern is used to depress the accelerator pedal for each depression amount. The higher the speed, the higher the stepping frequency, the greater the margin drive force T _oVR for giving a margin to the accelerator response from 0, and the higher the rate of change for each vehicle speed, the more the frequency of change. higher, greatly increase the reserve drive force T _OVR from 0, and outputs the reserve drive force T _{oV R.}

The target axle driving force calculation unit 28 determines the required axle driving force.
Power T_SMargin drive force T_oVRTarget axle drive force
T_oAsk for. Furthermore, the axle rotation speed calculation unit 22 uses the sensor 1
Secondary rotation speed N detected by 8 _sec, That is, shifting
The machine output speed is the gear of the final drive gear set 10.
Ratio (Final drive gear ratio) i_FTo divide by
Therefore, the axle speed N_SAsk for. And required horsepower calculation
The part 23 is the target axle driving force obtained respectively as described above.
T _oAnd axle speed N_SRequired horsepower HP by multiplication with_STo
calculate.

In the control target value calculation unit 24, the required horsepower H calculated above is calculated based on the characteristic diagram of the engine illustrated in FIG.
Engine speed N _e for generating P _S with minimum fuel consumption
Of seeking the target value N _e ^*, and outputs the the corresponding transmission target input revolution speed (target primary rotation speed) N _pri ^* to determine the target value T _e of the engine output (torque) T _e ^*. Here, FIG. 7, the engine speed N _e, the relationship between the engine output (torque) T _e, as iso-fuel consumption lines α fuel consumption rate becomes the same, also, equal horsepower line output horsepower becomes the same β Further, the minimum fuel consumption line connecting the points where the fuel consumption rate is highest on each constant horsepower line β is shown by δ.

In FIG. 7, the intersection of the equal horsepower line β and the minimum fuel consumption line δ corresponding to the required horsepower HP _S is, for example, Z in FIG.
If it is a point, the target engine speed N _e ^* and the target engine output T _e ^* for generating the required horsepower HP _S at the minimum fuel consumption are shown on the horizontal axis and the vertical axis from the Z point as shown in FIG. Each can be calculated as a scale value lowered. In a vehicle equipped with a continuously variable transmission, the torque converter 6 is in the lock-up state in which the input and output elements are directly connected for most of the time during power transmission. The engine speed N _pri ^* is treated as the same value as the target engine speed N _e ^* .

The transmission target input rotation speed N _pri ^* is input to the target transmission ratio calculation portion 25, and this calculation portion 25 divides the transmission target input rotation speed N _pri ^* by the transmission output rotation speed N _sec . As a result, the target gear ratio i ^* corresponding to the transmission target input speed N _pri ^* is obtained and output to the hydraulic actuator 12 as shown in FIG.
^* Is achieved, that is, the target transmission input speed N
Shift to achieve _pri ^* .

The wheel drive system target gear ratio calculation unit 30 calculates the wheel drive system target gear ratio i _T ^* represented by the ratio of the transmission target input speed N _pri ^* and the axle speed N _S to the engine. The output correction amount calculation unit 31 _obtains the engine output correction amount ΔT _e by dividing the surplus driving force T _oVR by the wheel drive system target gear ratio i _T ^* , and the corrected target engine output calculation unit 29 calculates the engine output correction amount ΔT _e . The corrected target engine output T _e0 by subtracting the engine output correction amount ΔT _e from the target engine output T _e ^*
Ask for ^* .

The corrected target engine output T _e0 ^* is input to the target throttle opening calculation unit 26, and this calculation unit 26
A target throttle opening TVO ^* that produces the corrected target engine output T _e0 ^* is obtained and output to the step motor 4 as shown in FIG. 1, and the throttle valve 5 is opened to the target throttle opening TVO ^*. Control.

According to the present embodiment as described above, the surplus driving force T _oVR is naturally 0 under the operating condition where the accelerator response margin is not required, and in this case, the computing unit 24
The target transmission input speed N _pri ^* and the target engine output T _e ^{* from} are respectively corresponding to only the target axle driving force T _o , and the engine speed (transmission input speed) for generating these with minimum fuel consumption. And the engine output, and the corrected target engine output T _e0 ^* from the calculation unit 29 is also equal to the target engine output T _e ^* .

Therefore, the shift control of the continuously variable transmission and the throttle opening control of the engine are performed in a manner that the required axle driving force T _S obtained from the driving condition and the running condition is generated with the minimum fuel consumption. It is possible to achieve both the improvement of and the minimum required power performance. According to the present embodiment, both the target engine speed N _e ^* (target transmission input speed N _pri ^* ) and the target engine output T _e ^* for generating the required horsepower HP _S with the minimum fuel consumption are shown. 7
The processing can be most easily performed since it is obtained from the engine characteristic diagram of.

By the way, a margin of accelerator response is required.
Driving force T _oVRCorresponds to that
Is greater than 0, the target axle drive force T_oIs the required axle
Driving force T_SMargin driving force T_oVRIt grows as much as
Corresponding to this, the transmission target input speed N_pri ^*And eyes
Target engine output T_e ^*Is raised. Transmission target input times
Number of turns N_pri ^*Rises the continuously variable transmission to the low speed side gear ratio.
Speed control will be achieved, and the accelerator response will be increased accordingly.
It is possible to achieve driving force control with emphasis on driving performance.
it can.

By the way, the increase in the target engine output T _e ^* causes the driving force to be excessively larger than the required axle driving force T _S by the marginal driving force T _oVR , and in addition, the shift control to the low speed side gear ratio is concerned. Excessive driving force is further promoted, and deterioration of fuel consumption from the minimum fuel consumption is increased.

However, in the present embodiment, the target error
Engine output T_e ^*Is the engine output correction amount ΔT_eJust subtract
Corrected target engine output T obtained by_e0 ^*So that
From controlling the throttle opening of the engine, and
Engine output correction amount ΔT_eAs described above, the transmission target
Input speed N _pri ^*Wheel drive system target gear ratio i obtained from
_T ^*Margin driving force T_oVRCan be calculated by dividing
Therefore, the engine output by the above throttle opening control is
All the above-mentioned causes of excessiveness are eliminated, and engine output is required for vehicles.
Axial driving force T_SCan correspond exactly to
To the extent that the deterioration of fuel consumption from the minimum fuel consumption can be almost ignored
It becomes possible to make things.

For this reason, it is possible to realize the driving force control with an emphasis on the driving performance by enhancing the accelerator response without a large deviation from the minimum fuel consumption. Moreover, the above-mentioned effects are achieved by switching between the driving force control with emphasis on fuel consumption and the driving force control with emphasis on power performance only by whether or not the margin driving force T _oVR is added to the required axle driving force T _S. You can
It is very cost effective.

FIG. 3 shows another embodiment of the present invention.
In the embodiment, the required horsepower is calculated by the control target value calculation unit 24.
HP_STarget engine speed to generate the minimum fuel consumption
Number N _e ^*(Target transmission input speed N_pri ^*) Only above
Similar to the embodiment described above, the engine characteristic diagram of FIG.
Therefore, the target engine output T_e ^*(Not shown in this figure)
Extra driving force T for accelerator response_oVRCorrected by the amount
Corrected target engine output T equivalent to_e0 ^*Is this
The following shall be obtained. That is, the wheel drive system
In the target gear ratio calculation unit 30, the transmission target input speed N_pri
^*And axle speed N_SThe target change of the wheel drive system expressed by the ratio of
Speed ratio i_T ^*And the corrected target engine output calculation unit 3
2, the required axle driving force T_SThe wheel drive system eye
Standard gear ratio i_T ^*Corrected target by dividing by
Engine power T_e0 ^*Ask for.

Here, the calculation result in the calculation unit 32 has been corrected.
Target engine output T_e0 ^*To explain the reason why
Wheel drive system target gear ratio i that is the basis of calculation_T ^*Calculation of
The transmission target input speed N_pri ^*Is used,
This transmission target input speed N _pri ^*Is already driving force T
_oVRIs calculated in consideration of
The calculation result at is the surplus driving force T_oVRDecrease with increasing
From this, the calculation result of the calculation unit 32 is the corrected target error.
Engine output T_e0 ^*It turns out that

According to such a configuration, the corrected target engine output T _e0 ^* is obtained by the above calculation, so that the time and effort required for map retrieval are reduced by half, and the map data shown in FIG. You can have a margin.

Here, the surplus driving force calculation unit 27 is not limited to the traveling state of the vehicle speed VSP and the accelerator opening APS described above, and as shown in FIG. 4, information from the road state determination unit 33 and the surplus driving force manual. You may make it determine according to the information from the command part 34.

The road condition judging section 33 is provided with an in-vehicle navigation system, information about the gradient from the road surface sensor,
The information about the curved road is supplied to the surplus driving force calculation unit 27,
The steeper the gradient and the steeper the change in the curve of the road surface, the more the margin drive force _ToVR is set to a value greater than 0, and the manual command unit 34 causes the margin drive force commanded by the driver according to his / her preference. _Is supplied to the calculation unit 27, and a margin driving force T _oVR larger than 0 corresponding to the command is output.

FIG. 5 shows still another embodiment of the present invention.
However, in the present embodiment, the target transmission input speed N
_pri ^*A method different from that in each of the above-described embodiments
Ask by. That is, the target transmission input speed calculation unit 35
Then, the target axle driving force T determined by the calculation unit 28_oAnd
And the vehicle speed detection value VSP by the sensor 19
For example, as shown in Fig.9, which was obtained as described later based on the characteristic diagram
The current vehicle speed VSP of the
Originally, the target axle driving force T_oGenerated with minimum fuel consumption
Engine speed N_eTarget value N_e ^*And then
Target engine speed N_e ^*Target input times for transmissions
Number of revolutions (target primary revolution) N_pri ^*Ask for.

[0066] To explain where the data of FIG. 9, the data obtained for as follows from the characteristic diagram of the engine shown in FIG. 7, the vehicle speed VSP and the transaxle force T _o, the engine speed N _e And have a relationship with. Figure 7 is already mentioned above, the engine speed N _e, the relationship between the engine output (torque) T _e, as iso-fuel consumption lines α fuel consumption rate becomes the same, also, equal horsepower output horsepower becomes the same A line β is shown, and the minimum fuel consumption line connecting the points where the fuel consumption rate is highest on each equal horsepower line β is shown by δ.

[0067] As in FIG. 8 individual points on a minimum fuel consumption line δ shown in FIG. 7, the vehicle speed VSP to the engine speed N _e by the gear ratio (including coefficients for this), and the engine output (torque) T _e Is transferred to the two-dimensional coordinates in which is replaced with the axle driving force T _o , and the vehicle speed VS is the minimum fuel consumption for each gear ratio
When determining the combination of P and the engine output (torque) T _e, it becomes a as shown in FIG.

Then, when the points at which the engine speed N _e is equal are plotted on the characteristic diagram for each gear ratio, it becomes as shown by A in FIG. 8 for a certain engine speed N _e . 7 is a graph showing the relationship between the vehicle speed VSP and the axle driving force T _o for each engine speed N _e .
The minimum fuel consumption line δ can be expressed by a line as shown in FIG.

[0069] For the sake of convenience in FIG. 9, denoted the engine speed N _e as the target engine speed N _e ^*, also denoted the transaxle force T _o as the target axle drive force (shown by the same reference numerals T _o) did.

The vehicle speed VSP and the target axle driving force T _o
According to the data representing the relationship between the target engine speed N _e ^* and the target engine speed N _e ^* , the case where the combination of the current vehicle speed VSP and the target axle driving force T _o corresponds to, for example, the point Z will be described. The target engine speed N _e ^* for generating the target axle driving force T _o with the minimum fuel consumption under VSP can be obtained as a parameter value (engine speed) related to the line passing through the point Z in FIG. 9. .

In the vehicle equipped with the continuously variable transmission, the torque converter 6 is in the lock-up state in which the input and output elements are directly connected for most of the time during power transmission. However, as in each of the above-described embodiments, the transmission target input rotation speed N _pri
^* Is treated as the same value as the target engine speed N _e ^* .

Transmission target input retrieved as described above
Number of revolutions N_pri ^*On the other hand, the target gear ratio in the calculation unit 25
i^*Of the continuously variable transmission described above.
As in the embodiment, the shift control is possible, and on the other hand, the arithmetic unit 30
Wheel drive system target gear ratio i_T ^*Is used for the calculation of
Corrected target engine output T from section 32_e0 ^*According to
Rotor opening control is possible in the same way as in each of the above-mentioned embodiments
To

According to the above-described embodiment as well, when the accelerator response margin is not required and the driving force control with emphasis on fuel consumption is required, the required axle driving force T _S obtained from the driving condition and the running condition is used. Since the shift control of the continuously variable transmission and the throttle opening degree control of the engine are performed in a manner such that the minimum fuel consumption is generated, it is possible to achieve both improvement of fuel consumption and minimum required power performance.

Then, when driving force control with emphasis on driving performance with a sufficient accelerator response is required, the target axle driving force T ₀ obtained by raising the required axle driving force T _S by the corresponding margin driving force T _oVR is the minimum. In order to achieve the transmission target input speed N _pri ^* generated by fuel consumption, the continuously variable transmission can be downshifted to enhance the accelerator response.
At this time, the corrected target engine output T _e0 ^* to the target throttle opening calculation unit 26 is obtained in the same manner as described above with reference to FIG. The force is reduced by the _amount corresponding to T _{oVR, and the} minimum fuel consumption is not significantly deteriorated even when the driving force control is performed with emphasis on the driving performance.

FIG. 6 shows still another embodiment of the present invention,
In the present embodiment, the target throttle opening calculation unit 26
To the corrected target engine output T as shown in FIG._e0 ^*Enter
Instead of issuing the request engine,
Force T_e1 ^*To enter. That is, basically
The configuration is the same as that in 5, and only the differences will be described.
Then, the axle speed N calculated by the axle speed calculator 24_STo
It is input to the wheel drive system actual gear ratio calculation unit 36. This calculation unit
36 is the primary speed detected by the sensor 17
N_pri, That is, transmission input speed N_priThe axle speed N
_SAnd the actual gear ratio i of the wheel drive system _TAsk for.

Then, the required engine output calculation unit 37 divides the required axle drive force T _S by the wheel drive system actual gear ratio i _T to obtain the required engine output (torque) T _e1 ^* , which is the target throttle. It is supplied to the opening degree calculation unit 26 and contributes to the calculation of the target throttle opening degree TVO ^* . In this case, since the target throttle opening TVO ^* is not _related to the surplus driving force T _oVR at all, unlike the case of FIG. 5, the throttle opening is equivalent to the surplus driving force T _oVR during the shift control for enhancing the shift response. It was confirmed that it is within the range where there is no hindrance, although the fuel consumption is slightly deteriorated during the driving force control with emphasis on the driving performance.

Needless to say, the wheel drive system target gear ratio i _T ^* in FIGS. 2 to 4 can be replaced with the wheel drive system actual gear ratio i _T as in the case of FIG.

By the way, as shown in FIGS. 5 and 6 described above.
In each embodiment, based on the data map shown in FIG.
Based on the target engine speed N_e ^*(Target transmission input rotation
Number N _pri ^*), But instead of
Even if the data map corresponding to the solid line 11 is used,
Target target engine speed N_e ^*(Target transmission input times
Number of turns N_pri ^*) Can be searched.

Here, the data map of FIG. 11 will be described in detail. The vehicle speed VSP and the required axle driving force T _S in FIG. 9 obtained as described above from the characteristic diagram of the engine shown in FIG.
And the target transmission input speed N _pri ^* of the transmission are as shown in FIG. 10 when the required axle driving force T _S is used as a parameter and the change characteristic of the target input speed N _pri ^* of the transmission with respect to the vehicle speed VSP is replaced. . As shown in FIG. 11 with respect to FIG. 10, it is surrounded by a maximum gear ratio line a, a minimum gear ratio line b, a minimum input rotation line c, a maximum input rotation line d, and a maximum vehicle speed line e. When the shiftable range is defined, a shift pattern showing the relationship of the transmission target input speed N _pri ^* to the vehicle speed VSP with the required axle driving force T _S as a parameter is obtained as shown by the solid line, and based on this, the vehicle speed VSP is obtained. Even if the transmission target input speed N _pri ^* is calculated from the required axle driving force T _S , the same operational effect as in each of the above-described embodiments can be achieved.

The gear shift pattern shown in FIG. 11 is equivalent to the gear shift pattern for a conventional continuously variable transmission in which the parameter is changed from the accelerator opening to the required axle driving force T _S. Even if the area enclosed by the two-dot chain line is taken out of the minimum fuel consumption driving control for the purpose of noise reduction, etc., the area is set according to the same idea as before without any special measures. Further, the operation of removing from the minimum fuel consumption driving control in order to prioritize a certain condition only in a specific region can be set with exactly the same know-how as the conventional one.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing a power train of a vehicle equipped with a continuously variable transmission equipped with a driving force control device according to an embodiment of the present invention together with its control system.

FIG. 2 is a functional block diagram of shift control and throttle opening control executed by a controller in the embodiment.

FIG. 3 is a functional block diagram of shift control and throttle opening control according to another embodiment of the present invention.

FIG. 4 is a functional block diagram of shift control and throttle opening control showing still another embodiment of the present invention.

FIG. 5 is a functional block diagram of shift control and throttle opening control showing still another embodiment of the present invention.

FIG. 6 is a functional block diagram of shift control and throttle opening control showing still another embodiment of the present invention.

FIG. 7 is a two-dimensional coordinate defined by an engine speed axis and an engine output torque axis, on which a constant fuel consumption line, a constant horsepower line,
It is an engine characteristic diagram showing the minimum fuel consumption line.

FIG. 8 is a diagram in which the minimum fuel consumption line is rewritten as a relation diagram between a vehicle speed and an axle driving force for each gear ratio.

9 is a shift pattern diagram of the continuously variable transmission represented as a diagram in which points at which input rotations are equal for each gear ratio are connected on the diagram of FIG. 8.

10 is a diagram in which the shift pattern of FIG. 9 is rewritten so that the required axle driving force is a parameter.

11 is a shift pattern diagram of the continuously variable transmission, which is raised based on the diagram of FIG.

[Explanation of symbols]

1 engine 2 continuously variable transmission 3 accelerator pedal 4 step motor 5 Electronically controlled throttle valve 6 Torque converter 7 Primary pulley 8 secondary pulley 9 V belt 10 Final drive gear set 11 Differential gear unit 12 Hydraulic actuator 13 Controller 14 Accelerator position sensor 16 Throttle position sensor 17 Primary pulley rotation sensor 18 Secondary pulley rotation sensor 19 Vehicle speed sensor 21 Required axle driving force calculator 22 Axle speed calculator 23 Required horsepower calculator 24 Control target value calculator 25 Target gear ratio calculator 26 Target throttle opening calculator 27 Marginal driving force calculator 28 Target axle driving force calculator 29 Corrected target engine output calculator 30 Wheel drive system target gear ratio calculator 31 Engine output correction amount calculator 32 Corrected target engine output calculator 33 Road condition determination unit 34 Accelerator response margin ratio Manual command section 35 Target transmission input speed calculator 36 Wheel drive system Actual gear ratio calculator 37 Request engine output calculator

Continuation of the front page (51) Int.Cl. ⁷ Identification code FI F02D 41/04 310 F02D 41/04 310G F16H 9/00 F16H 9/00 61/02 61/02 // F16H 59:42 59:42 (72 ) Inventor Minori Iwasaki 2 Takara-cho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (72) Inventor Katsuhiko Tsuchiya 2 Takara-cho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (72) Hideaki Watanabe Kanagawa 2 Takaracho, Kanagawa-ku, Yokohama, Japan (56) References JP 62-199536 (JP, A) JP 58-189713 (JP, A) JP 2-237828 (JP, A) JP-A-62-110536 (JP, A) JP-A-61-132422 (JP, A) JP-A-62-111151 (JP, A) JP-A-63-38742 (JP, A) JP-A-2 -241845 (JP, A) JP 59-200853 (JP, A) JP 7-172217 (JP, A) JP 9-166208 (JP, A) JP 5-262169 (JP, ) (58) investigated the field (Int.Cl. ^7, DB name) F02D 29/00 - 29/06 F02D 41/00 - 45/00 B60K 41/00 - 41/28

Claims (9)

(57) [Claims] 1. A vehicle equipped with a power train that is a combination of an engine whose throttle opening is controlled toward a target value that can be corrected by factors other than accelerator pedal operation and a continuously variable transmission, In order to generate the target axle drive force with minimum fuel consumption, which is calculated by adding the required axle drive force that is determined by the operating conditions and running conditions, to the driving force for the accelerator response margin that is also set based on the operating conditions and running conditions. The target engine speed and the target engine output are combined, and the target engine output is corrected by reducing the margin driving force to obtain a corrected target engine output, and the transmission target input speed corresponding to the target engine speed is calculated. Shift control of the continuously variable transmission to be a number,
A driving force control device for a vehicle, which is configured to control a throttle opening so as to obtain the corrected target engine output. 2. The engine according to claim 1, wherein a required horsepower is obtained by multiplying the target axle driving force and an axle speed, and a combination of an engine speed and an engine output for generating the required horsepower with minimum fuel consumption is used. A driving force control device for a vehicle, characterized in that the engine speed and the engine output are obtained from the characteristic diagram to be the target engine speed and the target engine output. 3. The engine output correction amount according to claim 1, wherein the margin drive force is divided by a wheel drive system target gear ratio, which is a ratio between the transmission target input speed and the axle speed. A driving force control apparatus for a vehicle configured to subtract the target engine output to obtain the corrected target engine output. 4. The engine speed and the engine output for generating the required horsepower with minimum fuel consumption according to claim 1, wherein the required horsepower is obtained by multiplying the target axle driving force by the axle speed. A wheel represented by a ratio of an axle rotational speed to the transmission target input rotational speed corresponding to the target engine rotational speed by obtaining only the rotational speed from the engine characteristic diagram and setting the engine rotational speed as the target engine rotational speed. A driving force control apparatus for a vehicle, wherein the corrected target engine output is obtained by dividing the required axle driving force by a drive system target gear ratio. 5. A factor other than the operation of the accelerator pedal
The throttle opening is controlled toward the correctable target value
Power that combines an engine and a continuously variable transmission
For vehicles equipped with a train, the required axle driving force that is determined by the operating conditions and running conditions of the vehicle
Also, the surplus driving force determined based on the driving condition and driving conditions
From the target axle drive force and vehicle speed obtained by adding
Therefore, obtain it based on the minimum fuel consumption line on the engine characteristic diagram.
The relationship between the vehicle speed, the axle driving force, and the engine speed is displayed.
Generate the target axle drive force with the lowest fuel consumption based on
To obtain the target engine speed for the transmission, and the transmission target input corresponding to this target engine speed.
Wheel drive system index expressed as the ratio of axle rotation speed to rotation speed
By dividing the required axle drive force by the gear ratio,
Corrected target engine that has been reduced by the marginal driving force
Obtain the output, and adjust the continuously variable transmission so that the target transmission speed is reached.
Shift control and at the same time the corrected target engine output
The feature is that the throttle opening is controlled so that
Vehicle driving force control device to be considered. 6. A vehicle equipped with a power train that is a combination of an engine and a continuously variable transmission whose throttle opening is controlled toward a target value that can be corrected by factors other than accelerator pedal operation. Based on the target axle drive force, which is obtained by adding the required axle drive force that is determined by the operating conditions and running conditions, to the margin drive force that is also determined based on the operating conditions and running conditions, and the vehicle speed, the minimum value on the engine characteristic diagram is set in advance. Based on the data representing the relationship between the vehicle speed, the axle driving force, and the engine speed that have been obtained based on the fuel consumption line, the target engine speed for generating the target axle driving force with the minimum fuel consumption is calculated. The required engine output is obtained by dividing the required axle drive force by the wheel drive system actual speed ratio represented by the ratio of the axle speed to the input speed, and the transmission target input speed So as the well as the shift control of the continuously variable transmission, the driving force control apparatus for a vehicle, characterized in that the arrangement for controlling the throttle opening so as to be the required engine output. 7. The data representing the relationship between the vehicle speed, the axle driving force, and the engine speed as set forth in claim 5 or 6, wherein each point on the minimum fuel consumption line is an engine speed based on a coefficient related to a gear ratio. Is a vehicle speed, and the engine output is transferred to an axle driving force on a two-dimensional coordinate, and is configured to be obtained in advance as a line connecting points having the same engine speed. Force control device. 8. The data representing the relationship between the vehicle speed, the axle driving force, and the engine speed according to claim 5 or 6, wherein each point on the minimum fuel consumption line is an engine speed based on a coefficient related to a gear ratio. Is replaced with the vehicle speed, and the engine output is replaced with the axle driving force, and a characteristic curve of the engine speed with respect to the vehicle speed is obtained in advance for each axle driving force. 9. The method according to any one of claims 1 to 8, wherein the surplus driving force is set to a depression amount of the accelerator pedal, a depression speed, a depression frequency, a high / low of a vehicle speed, a change rate, a change frequency, a road condition, and a driver's speed. A driving force control device for a vehicle, wherein the driving force control device is configured to be automatically or manually determined according to at least one of preferences.