JPH1182084A - Driving force control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reconcile driving force controls attaching importance to fuel consumption and accelerator responsiveness by controlling the throttle opening to a corrected target engine output determined by performing a variable control to a transmission target input rotating speed corresponding to a target engine rotating speed, and reducing and correcting the target engine output by a tolerant driving force. SOLUTION: A required horse power HPs is obtained by multiplying a target axle driving force To of a required axle power Ts determined by an accelerator opening APS and a vehicle speed VSP plus a tolerant driving force TOVR by an axle rotating speed Ns obtained from a transmission output rotating speed Nsec , a target engine rotating speed is determined by use of the required horse power HPS, corresponding transmission target input rotating speed Npri * and a target engine output torque Te * are then determined, and a target change gear ratio i* is determined and outputted by use of the transmission target input and output rotating speeds Npri , Nsec X. An engine output correction value ΔTe obtained by dividing a wheel driving system target gear change ratio ir * calculated by the ratio of the transmission target input rotating speed Npri * to the axle rotating speed Ns by the tolerant driving force TOVR is subtracted from the target engine output Te * to determine a corrected target engine output Teo * and then a throttle opening TVO*.

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 as to minimize the fuel consumption of an engine, and at the same time, sacrifice the fuel consumption. The present invention relates to a device for controlling the wheel driving force in such a manner that there is a margin in the accelerator response as required while minimizing the load.

[0002]

2. Description of the Related Art A continuously variable transmission represented by a V-belt type continuously variable transmission or a toroidal type continuously variable transmission generally determines a target gear ratio from an engine required load and a vehicle speed. Shift control is performed to achieve the target gear ratio.

[0003] Therefore, when the driver depresses the accelerator pedal to accelerate the engine to increase the required load, the target gear ratio is changed to be larger (to be a lower speed gear ratio). During a low-load operation in which the downshift is performed to the set target gear ratio and the driver returns the accelerator pedal to reduce the engine required load, on the contrary,
The target gear ratio is changed to be smaller (to be a higher gear ratio), and the continuously variable transmission is upshifted to the reduced target gear ratio.

On the other hand, as a technique for obtaining a required driving force of a vehicle, there is a conventional technique as 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 amount of accelerator pedal depression,
The required driving force to be transmitted to the wheels is added to the running resistance that can be estimated from the vehicle speed.

[0005]

However, in the above-described conventional speed change control of a continuously variable transmission, the required driving force obtained by the technique disclosed in the above-mentioned document cannot be accurately realized. In any case, it is impossible to realize the required driving force in such a manner as to minimize the fuel consumption of the engine only by the shift control of the transmission. And, 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 is minimized, the response necessarily incurs the responsiveness of the wheel driving force to the depression of the accelerator pedal, that is, The driver is dissatisfied with the power performance under conditions where acceleration performance should be emphasized because the vehicle is being driven with no allowance for the accelerator response.

[0006] Accordingly, even in a vehicle in which the driving force is controlled so as to minimize the fuel consumption of the engine, a margin is provided in the accelerator response as needed, and the driving force capable of exhibiting the required acceleration performance is provided. Control should also be possible. However, in the past, not only was the driving force controlled to minimize fuel consumption, but also a technical concept that allowed marginal driving force control with a minimum accelerator sacrifice while minimizing fuel consumption sacrifice. Was not present.

According to a first aspect of the present invention, by controlling the output of the engine and the shift control of the continuously variable transmission, the driving force control with an emphasis on the fuel consumption and the driving force with the emphasis on the accelerator response of the latter are provided. It is an object of the invention to propose a driving force control device for a vehicle that can achieve both control and control.

A second invention according to a second aspect of the present invention provides a simplest method of determining a combination of a target engine speed and a target engine output for generating a required horsepower in such a manner as to minimize the fuel consumption of the engine. The purpose is to be available.

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 or second aspect.

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

According to a fifth aspect of the present invention, a driving force control with an emphasis on fuel consumption and a driving force control with a margin for emphasizing an accelerator response can be made compatible with a different system from the first invention. It is an object of the present invention to propose a driving force control device for a vehicle.

According to a sixth aspect of the present invention, there is provided a simple driving force control device which can achieve substantially the same objects as those of the first and fifth aspects of the present invention by a method different from the first and fifth aspects of the present invention. The purpose is to do.

A seventh object of the present invention is to propose a preferable construction method of data used for obtaining a shift control amount of a 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.

A ninth aspect of the present invention is to propose a method of determining a marginal driving force for driving force control having a margin for emphasizing accelerator response in each of the above inventions.

[0016]

For these purposes, the vehicle driving force control apparatus according to the first invention controls the throttle opening toward a target value which can be corrected by a factor other than the operation of the accelerator pedal. Vehicle equipped with a power train that is a combination of an engine and a continuously variable transmission, the required axle driving force determined by the driving conditions and running conditions of the vehicle is also reduced by the accelerator response margin determined based on the driving conditions and running conditions. And a combination of the target engine speed and the target engine output for generating the target axle driving force obtained by adding the margin driving force at the minimum fuel consumption, and correcting the target engine output by the margin driving force. To obtain a corrected target engine output, and control the speed of the continuously variable transmission to achieve a transmission 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.

According to a second aspect of the present invention, there is provided a driving force control device for a vehicle.
In the first invention, a required horsepower is obtained by multiplying the target axle driving force by an axle rotational speed, and a combination of an engine rotational speed and an engine output for generating the required horsepower with minimum fuel consumption is determined from an engine characteristic diagram. The engine speed and the engine output are set to the target engine speed and the target engine output.

According to a third aspect of the present invention, there is provided a driving force control apparatus for a vehicle.
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 to an axle speed. The output is subtracted to obtain the corrected target engine output.

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

According to a fifth aspect of the present invention, there is provided a driving force control device for a vehicle.
An engine whose throttle opening is controlled to a target value that can be corrected by factors other than the accelerator pedal operation,
In a vehicle equipped with a power train that can be combined with a continuously variable transmission, the required axle driving force determined by the driving state and running conditions of the vehicle is added to the marginal driving force that is also determined based on the driving state and running conditions. The target axle driving force found,
And the target axle driving force at the lowest fuel efficiency based on data representing the relationship between the vehicle speed, the axle driving force, and the engine speed previously determined based on the lowest fuel consumption line on the engine characteristic diagram from the vehicle speed and the vehicle speed. A target engine speed to be generated is determined, and the required axle driving force is divided by a wheel drive system target speed ratio represented by a ratio of the axle speed to the transmission target input speed corresponding to the target engine speed. Thereby, a corrected target engine output reduced and corrected by the marginal driving force is obtained, and the speed of the continuously variable transmission is controlled to be the transmission target input rotation speed, and the corrected target engine output is obtained. The throttle opening is controlled.

A vehicle driving force control apparatus according to a sixth aspect of the present invention
An engine whose throttle opening is controlled to a target value that can be corrected by factors other than the accelerator pedal operation,
In a vehicle equipped with a power train that can be combined with a continuously variable transmission, the required axle driving force determined by the driving state and running conditions of the vehicle is added to the marginal driving force that is also determined based on the driving state and running conditions. The target axle driving force found,
And the target axle driving force at the lowest fuel efficiency based on data representing the relationship between the vehicle speed, the axle driving force, and the engine speed previously determined based on the lowest fuel consumption line on the engine characteristic diagram from the vehicle speed and the vehicle speed. Calculating a target engine speed to generate a required engine output by dividing the supply axle driving force by a wheel drive system actual gear ratio represented by a ratio of an axle rotation speed to a transmission input rotation speed to obtain a required engine output; Controlling the speed of the continuously variable transmission so as to reach the target input speed,
The throttle opening is controlled so as to obtain the required engine output.

A vehicle driving force control apparatus according to a seventh aspect of the present invention
According to the fifth or sixth aspect of the present invention, the data representing the relationship among the vehicle speed, the axle driving force, and the engine speed is obtained as follows. In other words, the individual points on the minimum fuel consumption line are transferred to 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 the coefficient relating to the gear ratio, and the points at which the engine speeds are equal. Is determined in advance as a line connecting.

According to an eighth aspect of the present invention, there is provided a driving force control device for a vehicle,
According to the fifth or sixth aspect of the present invention, the data representing the relationship among the vehicle speed, the axle driving force, and the engine speed is obtained as follows. In other words, each point on the minimum fuel consumption line is replaced by a 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. Ask for it.

A vehicle driving force control apparatus according to a ninth aspect of the present invention
In any one of the first invention to the eighth invention, the marginal driving force is at least one of an accelerator pedal depression amount, a depression speed, a depression frequency, a vehicle speed, a change rate, a change frequency, a road condition, and a driver's preference. Is determined automatically or manually according to

[0025]

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

According to the first aspect of the present invention, in particular, the required axle driving force determined by the driving state and the running conditions of the vehicle is added with a marginal driving force for the accelerator response margin which is also determined based on the driving state and the running conditions. A combination of the target engine speed and the target engine output for generating the target axle driving force at the lowest fuel consumption is obtained, and first, the continuously variable transmission is shifted so that the transmission has the target input speed corresponding to the target engine speed. Control, and further, the throttle opening is controlled so as to be a corrected target engine output obtained by correcting the target engine output to decrease by the marginal driving force.
On the other hand, the transmission target input speed is increased by the amount of the marginal driving force, and the continuously variable transmission is set to the low speed side gear ratio. The emphasis on the driving force control is realized, and on the other hand, the throttle opening is reduced by the corrected target engine output by the increase in the transmission input rotation speed due to the above-mentioned shift control, which has an adverse effect on the minimum fuel consumption. Can be minimized and the above-mentioned emphasis on driving performance can be realized.

As long as the marginal driving force is not required, the driving force control is performed such that the required axle driving force is generated with the minimum fuel consumption, so that the driving force control with an emphasis on fuel consumption can be realized. In addition, the switching of the driving force control mode can be achieved by a simple logic of whether or not the marginal driving force is added to the required axle driving force, which is very advantageous in cost.

As described above, in the first aspect of the present invention, while the required axle driving force is normally generated with the minimum fuel consumption, the driving performance with a margin in the accelerator response as required is greatly reduced in the minimum fuel consumption. It can be realized in a non-existent manner.

In the second invention, when obtaining the target engine speed and the target engine output in the first invention, the required horsepower is obtained by multiplying the required axle driving force by the axle speed, and the required horsepower is calculated with minimum fuel consumption. The combination of the target engine speed and the target engine output is the easiest to obtain the target engine speed and the target engine output because the combination of the engine speed and the engine output to be generated is obtained from the engine characteristic diagram and used as the target engine speed and the target engine output. It is advantageous to be able to ask.

In the third invention, the first invention or the second invention
The engine output correction amount obtained by dividing the marginal driving force by the wheel drive system target gear ratio, which is the ratio between the transmission target input rotation speed and the axle rotation speed, is subtracted from the target engine output obtained by the invention, and is corrected. 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.

In obtaining the target engine speed and the corrected target engine output in the first invention, the required horsepower is obtained by multiplying the target axle driving force and the axle speed as in the fourth invention, and the required horsepower is calculated. Of the engine speed and engine output for generating the lowest fuel consumption, only the engine speed is obtained from an engine characteristic diagram, and the engine speed is set as a target engine speed, and the speed change corresponding to the target engine speed is performed. The corrected target engine output can be obtained by dividing the required axle driving force by the wheel drive system target speed 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 the search and the corrected target engine output is obtained by the calculation, the frequency of the search can be reduced.

In the fifth invention, a target axle driving force obtained by adding a marginal driving force which is also determined based on the driving condition and the running condition to a required axle driving force determined by the driving condition and the driving condition of the vehicle, and From the vehicle speed, a target axle driving force is generated at a minimum fuel consumption based on data representing a relationship between a vehicle speed, an axle driving force, and an engine speed previously determined based on a minimum fuel consumption line on an engine characteristic diagram. The target speed of the continuously variable transmission is controlled so that the target input speed of the transmission corresponding to the target engine speed is obtained. Further, by dividing the required axle driving force by a wheel drive system target speed ratio represented by a ratio of the axle rotation speed to the transmission target input rotation speed, the corrected target engine reduced and corrected by the margin driving force. The output is obtained, and the throttle opening is controlled to achieve the corrected target engine output.

Therefore, also in the fifth invention, the transmission target input rotation speed is increased by the addition of the margin driving force, and the continuously variable transmission is set to the low speed side gear ratio. Driving force control with an emphasis on driving performance with a margin can be realized. On the other hand, the throttle opening is reduced by the corrected target engine output to the extent that the transmission input rotation speed is increased by the above-described shift control, and the driving performance is suppressed while the adverse effect on the minimum fuel consumption is minimized. The emphasis purpose can be achieved.

Then, as long as the marginal driving force is not required, the driving force control is performed such that the required axle driving force is generated with the minimum fuel consumption, so that the driving force control with an emphasis on fuel consumption can be realized. In addition, the switching of the driving force control mode can be achieved by a simple logic of whether or not the marginal driving force is added to the required axle driving force, which is very advantageous in cost.

As described above, according to the fifth aspect of the present invention, while the required axle driving force is normally generated with the minimum fuel consumption, the driving performance with a margin in the accelerator response as required is greatly sacrificed in the minimum fuel consumption. It is possible to achieve the same object as in the first invention, which is realized in an aspect that does not have any.

In the sixth invention, a target axle driving force obtained by adding a marginal driving force determined based on the driving condition and the running condition to a required axle driving force determined by the driving condition and the driving condition of the vehicle, and The target axle driving force is generated at the lowest fuel efficiency based on the data representing the relationship between the vehicle speed, the axle driving force, and the engine speed previously determined from the vehicle speed based on the lowest fuel consumption line on the engine characteristic diagram. A target engine speed for the transmission is determined, and the speed of the continuously variable transmission is controlled so that a transmission target input speed corresponding to the target engine speed is obtained. Further, the required engine output is obtained by dividing the marginal driving force by the actual gear ratio of the wheel drive system represented by the ratio of the axle rotation speed to the transmission input rotation speed, and the throttle opening is controlled so that the required engine output is obtained. I do.

Therefore, in the sixth invention, on the other hand, the transmission target input rotation speed is increased by the addition of the margin driving force, and the continuously variable transmission is set to the low speed side gear ratio. The same operation and effect as the first and fifth aspects of the invention can be achieved in that the driving force control with emphasis on the driving performance with the required margin can be realized. Thus, the required engine output uses the actual wheel drive system gear ratio instead of the wheel drive system target gear ratio in consideration of the marginal drive force in its calculation. The throttle opening control according to the required engine output is not the one that has been compensated for the rise, and the goal of driving performance is achieved while minimizing the adverse effect on the minimum fuel consumption. Nonetheless, the objectives can still be achieved to some extent in practice.

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

In the seventh invention, each point on the minimum fuel consumption line is transferred to 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 Since the data representing the relationship between the vehicle speed, the axle driving force, and the engine speed in the fifth or sixth aspect of the present invention is determined in advance as a line connecting points having the same engine speed, The accuracy of the target engine speed obtained based on the data can be made accurate according to the actual situation.

According to an eighth aspect of the present invention, each point on the minimum fuel consumption line is replaced with an engine speed by a coefficient relating to a gear ratio, a vehicle speed, and an engine output by an axle driving force. Since the 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 obtained in advance as the characteristic curve of the rotation speed, 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 gear shift control map only changes the parameter from the conventional accelerator opening to the axle driving force. Even in the case of performing a shift other than the above, the object can be achieved by following the conventional concept as it is.

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

[0042]

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

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

For shifting of the continuously variable transmission 2, one of the flanges forming the V-grooves of the primary pulley 7 and the secondary pulley 8 is moved closer to the other fixed flange. The width of the V-groove can be reduced by moving the movable pulley, and the width of the V-groove can be increased by separating the two pulleys from the primary pulley pressure _Ppri and the secondary pulley pressure from the hydraulic actuator 12 that responds to the target gear ratio (i ^* ) command. by displacing to a position corresponding to P _sec, and as it can be continuously variable to the continuously variable transmission 2 is the actual gear ratio matches the target gear ratio i ^*.

The target throttle opening TVO ^* and the target gear ratio i ^* are calculated and obtained by the controller 13. Because of this, the controller 13
Depressed position of accelerator pedal 3 (accelerator opening) AP
And a throttle opening sensor 1 for detecting a throttle opening TVO.
6, a signal from a primary pulley rotation sensor 17 for detecting the rotation speed (primary rotation speed) _Npri of the primary pulley 7, and a secondary pulley for detecting the rotation speed (secondary rotation speed) _Nsec of the secondary pulley 8. A signal from the rotation sensor 18 and a signal from a vehicle speed sensor 19 for detecting a vehicle speed VSP are input.

Based on the input information, the controller 13 controls the shift control of the continuously variable transmission 2 and the throttle opening degree control of the engine 1 as follows, as shown in a functional block diagram in 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, the required minimum axle driving force T _S according to the driving state and running conditions of the vehicle is obtained by, for example, the method described in the literature. Ask for.

The accelerator response margin driving force calculation unit 27
The vehicle speed VSP and the accelerator opening APS are respectively input. For example, in the stepped automatic transmission, the depression is performed for each depression amount of the accelerator pedal by the same concept as when switching between the normal pattern focusing on fuel consumption and the power pattern focusing on power performance. The higher the speed, the higher the stepping frequency, the greater the marginal driving force _ToVR for giving a margin to the accelerator response from 0, and, for each vehicle speed, the higher the rate of change and 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 calculator 28 calculates the required axle drive
Power T_SDrive power T_oVRAnd the target axle driving force
T_oAsk for. Further, the axle rotation speed calculation unit 22 includes the sensor 1
8, the secondary rotation speed N detected _secThat is, shifting
Machine output rotation speed, the gear of final drive gear set 10
Ratio (final drive gear ratio) i_FTo divide by
Therefore, the axle rotation speed N_SAsk for. And required horsepower calculation
The unit 23 calculates the target axle driving force obtained as described above.
T _oAnd axle speed N_SRequired HP by multiplying by_STo
calculate.

The control target value calculator 24 calculates the required horsepower H calculated based on the characteristic diagram of the engine illustrated in FIG.
Engine speed N _e for generating P _S at the lowest 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 And the lowest fuel consumption line connecting points at which the fuel consumption rate becomes the best on each isohorsepower line β is indicated by δ.

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

The transmission target input rotation speed N _pri ^* is input to a target gear ratio calculation unit 25, which divides the transmission target input rotation speed N _pri ^* by the transmission output rotation speed N _sec . As a result, the target speed 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 transmission target input speed N
Shift gears to achieve _pri ^* .

The wheel drive system target gear ratio calculation unit 30 calculates a wheel drive system target gear ratio i _T ^* represented by a ratio between the transmission target input rotational speed N _pri ^* and the axle rotational speed N _S , output correction amount calculation unit 31, by dividing the excess driving force T _OVR in wheel drive system target speed ratio i _T ^*, obtains the engine output correction amount [Delta] T _e, corrected target engine output computing section 29, the The corrected target engine output T _{e0 is obtained} by subtracting the engine output correction amount ΔT _e from the target engine output T _e ^{*.
Ask *} .

The corrected target engine output _Te0 ^* is input to a target throttle opening calculating unit 26, and the calculating unit 26
A target throttle opening TVO ^{* at} which the corrected target engine output _Te0 ^* is generated 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 the degree.

According to the present embodiment as described above, the surplus driving force _ToVR is naturally 0 in an operation state in which a margin of the accelerator response is not required.
Transmission target input rotation speed from N _pri ^* and the target engine output T _e ^*, respectively, corresponding only to the target axle drive force T _o, the engine speed that generates this in minimum fuel consumption (transmission input rotational speed) and an engine output, also corrected target engine output T from the calculating unit 29 _e0 ^* is also equal to the target engine output T _e ^*.

Therefore, the shift control of the continuously variable transmission and the throttle opening degree control of the engine are performed in such a manner that the required axle driving force T _S obtained from the driving conditions and running conditions is generated at the lowest fuel consumption. And the minimum required power performance can be achieved at the same time. Incidentally, according to this embodiment, both the target engine speed N _e ^* (target transmission input rotation speed N _pri ^*) and the target engine output T _e ^* to generate the required horsepower HP _S Lowest mileage FIG 7
From the engine characteristic diagram, the processing can be performed most easily.

By the way, a margin of the accelerator response is required.
The driving force T _oVRCorrespond to it
Is greater than 0, the target axle driving force T_oIs required axle
Driving force T_SDrive force T_oVRIt gets bigger by the minute,
Correspondingly, 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 ^*Increases the continuously variable transmission to the lower gear ratio.
Speed control, and the accelerator response is increased accordingly.
It is possible to achieve driving force control that emphasizes driving performance
it can.

By the way increase the target engine output T _e ^* leads to excessive driving force than just requesting transaxle force T _S reserve drive force T _OVR min, an additional gear shift control to the low-speed gear ratio is the Excessive driving force is further promoted, and the deterioration of fuel efficiency from the minimum fuel efficiency is increased.

In this embodiment, however, the target energy
Engine output T_e ^*To the engine output correction amount ΔT_eJust subtract
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 ^*Drive system target gear ratio i obtained from
_T ^*Drive power T_oVRCalculated by dividing
From the above, the engine output by the throttle opening control is
All of the above causes have been removed, and the vehicle requires engine output
Shaft driving force T_SCan correspond exactly to
Degradation of fuel economy from minimum fuel economy can be almost ignored
It becomes possible.

For this reason, it is possible to enhance the accelerator response without greatly deviating from the minimum fuel consumption, and to realize the driving force control emphasizing the driving performance. In addition, the above-mentioned effects are achieved by switching between the driving force control focusing on fuel efficiency and the driving force control focusing on power performance only by adding the margin driving force _{ToVR to} the required axle driving force T _S. Can be
This is very advantageous in terms of cost.

FIG. 3 shows another embodiment of the present invention.
In the present embodiment, the required horsepower
HP_STarget engine speed to generate the minimum fuel consumption
Number N _e ^*(Target transmission input rotation speed N_pri ^*) Only above
Similarly to the embodiment shown in FIG.
The target engine output T_e ^*(Not shown in this figure)
Extra driving force T for accelerator response_oVRCorrected by the minute
Corrected engine output T corresponding to_e0 ^*Will
It shall be obtained as follows. In other words, the wheel drive system
In the target gear ratio calculating section 30, the transmission target input speed N_pri
^*And axle speed N_STarget change expressed by the ratio of
Speed ratio i_T ^*Is calculated, and the corrected target engine output calculation unit 3
2, the required axle driving force T_SThe wheel drive system
Standard gear ratio i_T ^*Target corrected 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 why
Wheel drive system target gear ratio i from which the calculation is based_T ^*Calculation
In addition, the transmission target input speed N_pri ^*Is used,
This transmission target input speed N _pri ^*Already has a marginal driving force T
_oVRIs calculated in consideration of
Is the driving force T_oVRDecrease as the
From this, the calculation result of the calculation unit 32 is
Engine output T_e0 ^*It turns out that it is.

According to this configuration, since the corrected target engine output _Te0 ^* is obtained by the above-described calculation, the time and effort for searching the map can be reduced by half, and the map data does not need all of the data in FIG. It can give room.

Here, the margin driving force calculation unit 27 includes not only the traveling state of the vehicle speed VSP and the accelerator opening APS, but also information from the road state determination unit 33 and the margin driving force manual as shown in FIG. The determination may be made according to information from the command unit 34.

The road condition judging section 33 is provided with information on a gradient from an on-vehicle navigation system and a road surface sensor,
Information on the curved road is supplied to the margin driving force calculation unit 27,
As the gradient becomes steeper and the curve of the road surface changes more steeply, the spare driving force _ToVR is set to a value larger than 0, and the manual command unit 34 outputs the spare driving force commanded by the driver according to his / her preference. _Is supplied to the calculation unit 27 to output a marginal driving force _ToVR larger than 0 corresponding to the command.

FIG. 5 shows still another embodiment of the present invention.
However, in the present embodiment, the target transmission input rotation speed N
_pri ^*Is different from the above-described embodiments.
Ask by That is, the target transmission input rotation speed calculation unit 35
The target axle driving force T calculated by the arithmetic unit 28_oAnd
From the vehicle speed detection value VSP detected by the
For example, as shown in FIG.
Based on the map corresponding to the current vehicle speed VSP
The above-mentioned target axle driving force T_oGenerate the lowest fuel consumption
Engine speed N_eTarget value N_e ^*And then
Target engine speed N_e ^*Transmission target input times corresponding to
Number of rotations (target primary rotation speed) 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 the relationship. 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 The minimum fuel consumption line connecting points at which the fuel consumption rate is the best on each isohorsepower line β is indicated 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 the marked shift to the two-dimensional coordinate system by replacing the transaxle force T _o, the lowest fuel consumption per speed ratio speed VS
When determining the combination of P and the engine output (torque) T _e, it becomes a as shown in FIG.

[0068] When the plots points engine speed N _e to the diagram characteristic line for each gear ratio is equal, in the case of certain engine speed N _e, it is assumed such indicated by A in FIG. 8, these points signed a, indicating the relationship between the vehicle speed VSP and the axle drive force T _o for each engine speed N _e, 7
Can be represented 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.

[0070] and take the vehicle speed VSP, the target axle driving force T _o
When, according to the data representing the relationship between the target engine speed N _e ^*, the case is described in which the combination of the current vehicle speed VSP and the target axle drive force T _o is corresponding to, for example, the point Z, the vehicle speed target axle drive force T _o target engine speed for generating a minimum fuel consumption N _e ^* is under VSP, may be determined as the parameter value relating to a line passing through the point Z in FIG. 9 (engine speed) .

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

Transmission target input searched as described above
Revolution N_pri ^*Is, on the other hand, the target gear ratio in the arithmetic unit 25.
i^*Of the continuously variable transmission in each of the above-described embodiments.
In the same manner as in the embodiment, the shift control can be performed.
Target gear ratio i of the wheel drive system_T ^*The calculation of the
Corrected engine output T from section 32_e0 ^*According to
Rottle opening control is possible in the same way as in the previous embodiments.
To

According to the present embodiment as described above, when a margin of the accelerator response is not required and the driving force control with an emphasis on fuel consumption is required, the required axle driving force T _S obtained from the driving conditions and the driving conditions is used. The shift control of the continuously variable transmission and the throttle opening control of the engine are performed in such a manner as to generate at the lowest fuel efficiency, so that it is possible to achieve both improvement in fuel efficiency and minimum necessary power performance.

When the driving force control with an allowance for the driving performance that has a margin in the accelerator response is required, the target axle driving force T ₀ obtained by increasing the required axle driving force T _S by the corresponding margin driving force _{ToVR is} set to 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 increase the accelerator response.
At this time, the corrected target engine output _Te0 ^* to the target throttle opening calculating section 26 is obtained in the same manner as described above with reference to FIG. Since the power _{ToVR is} reduced by an _amount corresponding to the power _{ToVR, the} minimum fuel consumption does not greatly deteriorate even during the driving force control in which the driving performance is emphasized.

FIG. 6 shows still another embodiment of the present invention.
In the present embodiment, the target throttle opening calculating section 26
To the corrected target engine output T as shown in FIG._e0 ^*Enter
Request engine instead of
Force T_e1 ^*As input. In other words, basically
5, and only the differences will be described.
Then, the axle rotation speed N obtained by the axle rotation speed calculation unit 24_STo
It is input to the wheel drive system actual speed ratio calculation unit 36. This operation unit
36 is the primary rotation speed detected by the sensor 17
N_priThat is, the transmission input rotation speed N_priIs the axle speed N
_SAnd the actual gear ratio i of the wheel drive system _TAsk for.

[0076] Then, in the required engine output calculation unit 37 obtains the required engine output (torque) T _e1 ^* By dividing the required axle driving force T _S of the the wheel driveline actual gear ratio i _T, which a target throttle It is supplied to the opening calculating section 26 to contribute to the calculation of the target throttle opening TVO ^* . In this case, since the target throttle opening TVO ^* does not _{affect the} marginal driving force _ToVR at all, unlike FIG. 5, the throttle opening is _reduced by the marginal driving force _ToVR during the shift control for enhancing the shift response. However, it was confirmed that the fuel efficiency was slightly deteriorated during the driving force control with emphasis on the driving performance, but it was in a range where there was no problem.

It goes without saying that the wheel drive system target speed ratio i _T ^* in FIGS. 2 to 4 can be replaced with the wheel drive system actual speed ratio i _T as in FIG.

By the way, FIG. 5 and FIG.
In each embodiment, the data map shown in FIG.
Target engine speed N_e ^*(Target transmission input rotation
Number N _pri ^*), But instead of this,
Similarly, using the data map corresponding to the solid line 11
Target engine speed N_e ^*(Target transmission input times
Number of turns N_pri ^*) Can be searched.

Here, the data map in FIG. 11 will be described in detail. The vehicle speed VSP in FIG. 9 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.
When the relationship between the transmission target input rotational speed N _pri ^* is a required vehicle axle driving force T _S as a parameter, the as in FIG. 10 is replaced in the changing characteristic of the transmission target input rotational speed N _pri ^* against vehicle speed VSP . As shown in FIG. 11, as compared with FIG. 10, a maximum speed ratio line a, a minimum speed ratio line b, a minimum input rotation line c, a maximum input rotation line d, and a maximum vehicle speed line e are enclosed. When the shiftable region is defined, a shift pattern indicating the relationship between the transmission target input rotation speed _Npri ^* and the vehicle speed VSP using the required axle driving force T _S as a parameter as shown by a solid line is obtained, and based on this, the vehicle speed VSP is determined. Even when the transmission target input rotation speed N _pri ^* is obtained from the required axle driving force T _S , the same operation and effect as in the above embodiments can be achieved.

The speed change pattern shown in FIG. 11 is equal to the speed change pattern for the 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 indicated by the two-dot chain line is excluded from the minimum fuel consumption operation control for the purpose of noise control and the like, the area is set in the same way as before without any special measures. In addition, the operation of excluding from the minimum fuel consumption operation control to give priority to a certain condition only in a specific area can be set with exactly the same know-how as before.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory diagram 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 a control system thereof.

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

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

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

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

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

FIG. 7 shows an equal fuel consumption line, an equal horsepower line, and a two-dimensional coordinate line defined by an engine speed axis and an engine output torque axis.
FIG. 4 is a characteristic diagram of an engine showing a minimum fuel consumption line.

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

9 is a speed change pattern diagram of the continuously variable transmission shown as a diagram connecting points on the diagram of FIG. 8 at which the input rotation becomes equal for each speed ratio.

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

FIG. 11 is a shift pattern diagram of the continuously variable transmission that is raised based on the diagram of FIG. 10;

[Explanation of symbols]

 Reference Signs List 1 engine 2 continuously variable transmission 3 accelerator pedal 4 step motor 5 electronic control throttle valve 6 torque converter 7 primary pulley 8 secondary pulley 9 V belt 10 final drive gear set 11 differential gear device 12 hydraulic actuator 13 controller 14 accelerator opening sensor 16 Throttle opening sensor 17 Primary pulley rotation sensor 18 Secondary pulley rotation sensor 19 Vehicle speed sensor 21 Required axle driving force calculation unit 22 Axle rotation speed calculation unit 23 Required horsepower calculation unit 24 Control target value calculation unit 25 Target gear ratio calculation unit 26 Target throttle Opening degree computing section 27 Extra driving force computing section 28 Target axle driving force computing section 29 Corrected target engine output computing section 30 Wheel drive system target gear ratio computing section 31 Engine output correction amount computing section 32 Corrected target engine output computing section 33 Road condition determination unit 34 Accelerator Response margin manual command unit 35 Target transmission input rotation speed calculation unit 36 Wheel drive system actual gear ratio calculation unit 37 Request engine output calculation unit

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI F16H 61/02 F16H 61/02 // F16H 59:42 (72) Inventor Minori Iwasaki 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Inside (72) Inventor Katsuhiko Tsuchiya Nissan Motor Co., Ltd. (72) Inventor Hideaki Watanabe 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture

Claims (9)

[Claims] 1. A vehicle equipped with a power train that is a combination of an engine whose throttle opening is controlled to a target value that can be corrected by a factor other than the operation of an accelerator pedal and a continuously variable transmission. To generate the target axle driving force calculated by adding the marginal driving force for the accelerator response margin, which is also determined based on the driving state and driving conditions, to the required axle driving force determined by the driving conditions and driving conditions with minimum fuel consumption And a corrected target engine output is obtained by lowering and correcting the target engine output by the margin driving force, and a transmission target input rotation corresponding to the target engine speed is obtained. Controlling the speed of the continuously variable transmission so that
A driving force control device for a vehicle, wherein a throttle opening is controlled 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 by an axle rotational speed, and a combination of an engine rotational speed and an engine output for generating the required horsepower with minimum fuel consumption is determined. A driving force control device for a vehicle, wherein 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 marginal driving force is divided by a wheel drive system target speed ratio, which is a ratio of the transmission target input speed to the axle speed. A driving force control device for a vehicle, wherein the corrected target engine output is obtained by subtracting the target engine output. 4. The engine according to claim 1, wherein a required horsepower is obtained by multiplying the target axle driving force by an axle speed, and an engine speed and an engine output for generating the required horsepower with minimum fuel consumption. Only the rotational speed is obtained from an engine characteristic diagram, and this engine rotational speed is used as the target engine rotational speed. Wheels represented by the ratio of the axle rotational speed to the transmission target input rotational speed corresponding to the target engine rotational speed A driving force control device for a vehicle, wherein the corrected target engine output is obtained by dividing the required axle driving force by a driving system target gear ratio. 5. A vehicle equipped with a power train which is a combination of an engine whose throttle opening is controlled to a target value which can be corrected by a factor other than the operation of an accelerator pedal and a continuously variable transmission. From the target axle driving force obtained by adding the marginal driving force determined based on the driving condition and the running conditions to the required axle driving force determined by the driving conditions and the running conditions, and the vehicle speed, A target engine speed for generating the target axle driving force with minimum fuel consumption is determined based on data representing a relationship between the vehicle speed, the axle driving force, and the engine speed determined based on the fuel consumption line. By dividing the required axle driving force by a wheel drive system target speed ratio represented by a ratio of the axle speed to the transmission target input speed corresponding to the engine speed.
A corrected target engine output reduced and corrected by the marginal driving force is obtained, and the speed of the continuously variable transmission is controlled so as to be the transmission target input rotational speed, and the throttle opening is set to be the corrected target engine output. A driving force control device for a vehicle, characterized in that the driving force is controlled. 6. A vehicle equipped with a power train that is a combination of an engine whose throttle opening is controlled to a target value that can be corrected by a factor other than the operation of an accelerator pedal and a continuously variable transmission. From the target axle driving force obtained by adding the marginal driving force that is also determined based on the driving conditions and running conditions to the required axle driving force determined by the driving conditions and running conditions, and the vehicle speed, Based on data representing the relationship between the vehicle speed, axle driving force, and engine speed determined based on the fuel consumption line, a target engine speed for generating the target axle driving force with minimum fuel consumption is determined. The required engine output is obtained by dividing the required axle driving force by the actual wheel drive system gear ratio represented by the ratio of the axle rotation speed to the input rotation speed, and the transmission target input rotation 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 engine speed according to claim 5, wherein the data representing the relationship among the vehicle speed, the axle driving force, and the engine speed is obtained by dividing each point on the minimum fuel consumption line by a coefficient relating to a gear ratio. The vehicle speed and the engine output on the two-dimensional coordinates in which the engine output is replaced by the axle driving force, and is obtained in advance as a line connecting points having the same engine speed. Power control device. 8. The engine speed according to claim 5, wherein the data representing the relationship among the vehicle speed, the axle driving force, and the engine speed is obtained by dividing each point on the minimum fuel consumption line by a coefficient relating to a gear ratio. Is replaced with the vehicle speed and the engine output is replaced with the axle driving force, and the 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 claim 1, wherein the marginal driving force is determined based on a depression amount of an accelerator pedal, a depression speed, a depression frequency, a vehicle speed, a change rate, a change frequency, a road condition, and a driver's condition. A driving force control device for a vehicle, wherein the driving force control device is configured to be determined automatically or manually according to at least one of preferences.