JPH11257113A - Driving force control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To implement a required deceleration by speed control, and at the same time, to prevent interference with deceleration control by explicitly determining an engine power output. SOLUTION: In Block 21, a desired driving force Ts is obtained from an accelerator opening APS and a vehicle velocity VSP. In Block 23, a desired horsepower HPs is obtained by multiplying the Ts by an axle rotation number Ns . In Block 24, depending on an engine characteristic curve, a combination of a drive control transmission desired input rotation number Npri S which corresponds to an engine rotation number generating the HPs with a minimum fuel consumption rate, and a desired engine output Te * are obtained. In Block 28, a deceleration control transmission desired input rotation number Npri G for bringing a deceleration G to a predetermined value is obtained. In Block 27, a transmission desired input rotation number Npri * is derived from the Npri G at the time of a deceleration demand determination in Block 29 or the Npri S in another case. In Block 25, a desired transmission ratio i* corresponding to the Npri * is output (step 25). In Block 26, a drive control desired throttle opening TVOS generated by the Te * is obtained. In Block 31, a desired throttle opening TVO* is derived from a preset minimum throttle opening TVOG in Block 32 at the time of the deceleration demand determination, or the TVOS in another case.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving force control device for appropriately determining a required wheel driving force of a vehicle equipped with a continuously variable transmission as a combination of an engine output and a gear ratio, and more particularly to a vehicle control device. The present invention relates to a driving force control device useful during deceleration of a vehicle.

[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. Therefore, during acceleration in which the driver depresses the accelerator pedal to increase the required engine load, the target gear ratio is changed to be larger (to be a lower speed gear ratio), and the continuously variable transmission is set to the increased target gear ratio. When the vehicle is downshifted to the gear ratio, and conversely, during a low-load operation in which the driver returns the accelerator pedal to reduce the required engine load, the target gear ratio is changed to be smaller (to be a higher gear ratio). 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 technique described in, for example, JP-A-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.

[0004] By the way, in the above-mentioned conventional speed change control of a continuously variable transmission, the required driving force obtained by the technique disclosed in the above-mentioned literature cannot be accurately realized. In any case, it is impossible to realize the required driving force in such a manner that the fuel efficiency of the engine is minimized.

For example, in order to achieve the required driving force in such a manner that the fuel efficiency of the engine is minimized, the required driving force is controlled by controlling the output of the engine and the shift control of the continuously variable transmission (the engine speed). Control) that can be realized by an appropriate combination with (control). In this case, it is necessary to explicitly determine the throttle opening regardless of the accelerator pedal depression amount (accelerator opening), but in the accelerator pedal released state,
It is difficult to determine the required driving force of the driver from the accelerator pedal operation.

However, in any case, since it is clear that the driver is requesting deceleration of the vehicle in the accelerator pedal released state, the driving force is reduced in the accelerator pedal released state instead of the above-described driving force control. It is reasonable to perform speed control. Conventionally, as described in, for example, Japanese Patent Application Laid-Open No. Hei 9-112682, the deceleration control of the vehicle in such a case utilizes the fact that the friction of the engine when the accelerator pedal is released is correlated with the engine speed, 2. Description of the Related Art There is known an engine in which the friction of the engine is varied by changing the engine speed by controlling the speed ratio of a transmission so that the deceleration of the vehicle becomes a predetermined deceleration.

[0007]

In the above-described deceleration control, it is preferable that the relationship between the friction of the engine and the engine speed does not change during the control, otherwise the accuracy of the control is reduced. Therefore, even when the driving force control and the deceleration control are switched in accordance with the depression and release of the accelerator pedal, the engine output, that is, the throttle opening, at the time of release of the accelerator pedal is determined as described above. Need to be determined explicitly.

The above document, Japanese Patent Application Laid-Open No. 9-1126,
The deceleration control described in Japanese Patent Publication No. 82 is based on an engine output control device in which an accelerator opening and a throttle opening are associated with each other at a ratio of 1: 1. Does not suggest and does not meet the above requirements.

Further, when the required driving force at the time of releasing the accelerator pedal is obtained by the method described in the above-mentioned Japanese Patent Application Laid-Open No. 7-172217, and the engine output is controlled based on this, during the deceleration control, If the throttle opening is changed unnecessarily, a new problem arises such that the intake resistance of the engine changes and interferes with the deceleration control.

Therefore, in order to switch between the driving force control and the deceleration control in accordance with the depression and release of the accelerator pedal, the target engine output,
Alternatively, it is necessary to set a target throttle opening. In addition, if the throttle is opened excessively during deceleration, the drivability of the vehicle is deteriorated, for example, the shock at the time of transition from the fuel cut state to the fuel recovery due to the depression of the accelerator pedal increases.

According to a first aspect of the present invention, when the deceleration is requested, the driving force control is switched to the deceleration control. In this case, the vehicle does not have the contradiction and the problem. An object is to propose a driving force control device.

A second object of the present invention is to propose an engine output control at the time of switching to deceleration control, which is suitable for achieving the object of the first invention.

A third object of the present invention is to propose an engine output control at the time of switching to deceleration control, which is most suitable for achieving the object of the first invention.

A fourth object of the present invention is to propose a suitable engine output control object when the engine is an internal combustion engine.

A fifth object of the present invention is to propose the simplest engine output control for achieving the object of the first invention when the engine is an internal combustion engine.

A sixth object of the present invention is to provide a smooth engine control for achieving the object of the first invention when the engine is an internal combustion engine.

A seventh object of the present invention is to provide the operation and effect of the sixth invention most reliably.

An eighth aspect of the present invention is directed to propose a suitable deceleration request determination technique.

A ninth aspect of the present invention is to propose a most suitable deceleration request determination technique.

[0020]

SUMMARY OF THE INVENTION To achieve these objects, a first invention is to provide a power train which is a combination of an engine whose output can be arbitrarily changed by factors other than the operation of an accelerator pedal and a continuously variable transmission. A combination of a target engine speed and a target engine output for realizing a required axle driving force determined by the driving state and running conditions of the vehicle, and determining a transmission target corresponding to the target engine speed. In a vehicle driving force control device for controlling the speed of the continuously variable transmission so as to attain the input rotation speed and controlling the output of the engine so as to attain the target engine output, a request for deceleration of the vehicle is determined from a driving operation, At the time of request determination, the target engine speed is determined so that the vehicle deceleration becomes a predetermined deceleration, and the target engine output is fixed, Properly it is characterized in that it has configured to limit.

According to a second aspect of the present invention, there is provided a driving force control device for a vehicle.
In the first invention, the target engine output at the time of the deceleration request determination is configured to be less than a set output.

A driving force control device for a vehicle according to a third aspect of the present invention
In the second invention, the target engine output at the time of the deceleration request determination is configured to be a minimum output.

A vehicle driving force control apparatus according to a fourth aspect of the present invention
In any one of the first to third inventions, when the engine is an internal combustion engine, the target engine output is provided as a target engine torque or a target throttle opening.

According to a fifth aspect of the present invention, there is provided a driving force control device for a vehicle.
In the fourth invention, the target engine output at the time of the deceleration request determination is configured to be a throttle opening degree fully closing command.

According to a sixth aspect of the present invention, there is provided a driving force control device for a vehicle.
In the fourth invention, the target engine output at the time of the deceleration request determination is configured to be a throttle opening corresponding to an accelerator pedal depression amount converted from an accelerator pedal depression amount.

A vehicle driving force control apparatus according to a seventh aspect of the present invention
A sixth aspect of the invention is characterized in that the accelerator pedal depression amount and the throttle opening are made to correspond to each other on a 1: 1 basis in the conversion.

The vehicle driving force control apparatus according to the eighth invention is
In any one of the first to seventh inventions, the deceleration request determination is made based on an accelerator pedal operation.

A vehicle driving force control apparatus according to a ninth aspect of the present invention
An eighth aspect of the present invention is characterized in that when the accelerator pedal is released from the accelerator pedal depressed state, the deceleration request is determined.

[0029]

According to the first aspect of the present invention, a combination of a target engine speed and a target engine output for realizing a required axle driving force determined by the driving state and running conditions of the vehicle is determined, and a shift corresponding to the target engine speed is determined. The driving force control is performed so as to control the speed of the continuously variable transmission so as to attain the target engine input speed and to control the output of the engine so as to attain the target engine output. The output from the engine controlled as described above is shifted by the continuously variable transmission controlled to shift as described above and becomes the output of the power train.

In the first invention, in particular, a request for deceleration of the vehicle is determined from the driving operation. When the request for deceleration is determined, the target engine speed is determined so that the vehicle deceleration becomes a predetermined deceleration. At the time of the deceleration request determination, the control shifts from the above-described driving force control to deceleration control, and control corresponding to the deceleration request can be realized. At this time, since the target engine output is fixed or limited, the target engine output is explicitly determined even at the time of the deceleration request, so that the aforementioned request can be satisfied. During the above-mentioned deceleration control, the intake resistance of the engine is kept unchanged, interference with deceleration control can be avoided, and in addition, since the engine output is not increased unnecessarily during deceleration control, Thus, there is no problem that the shock at the time of fuel recovery increases.

In addition, since the deceleration control is realized by the shift control of the continuously variable transmission as described above, the deceleration control is performed in a control range more than when the control is performed by the engine output control such as the throttle opening control. And the effect of preventing the shock at the time of fuel recovery accompanying re-acceleration from increasing is further ensured.

In the second invention, the target engine output at the time of the deceleration request determination is made smaller than the set output, so that the engine output control during the deceleration control can more reliably achieve the object of the first invention. It will be.

In the third invention, the target engine output at the time of the deceleration request determination is set to the minimum output, so that the engine output control during the deceleration control can most reliably achieve the object of the first invention. Become.

In the fourth invention, when the engine is an internal combustion engine, in order to give the target engine output as a target engine torque or a target throttle opening,
When the engine is an internal combustion engine, the engine output control object is easily controlled and suitable.

In the fifth aspect of the invention, the target engine output at the time of the deceleration request determination is the throttle opening fully closed command. Therefore, when the engine is an internal combustion engine, the engine output control object is the simplest to control most easily. .

In the sixth aspect, the target engine output at the time of the deceleration request determination is a throttle opening corresponding to the accelerator pedal depression amount converted from the accelerator pedal depression amount. As a result, the change in the engine output does not become steep, and smooth operation can be guaranteed at the time of the deceleration request determination.

In the seventh aspect, the accelerator pedal depression amount and the throttle opening are made to correspond one to one in the above-mentioned conversion in the sixth aspect, so that the operation and effect of the sixth aspect can be made most reliable. can do.

In the eighth aspect of the present invention, the above-described determination of the deceleration request is performed based on the operation of the accelerator pedal, so that the driver's deceleration request can be suitably determined.

According to the ninth aspect of the present invention, since the deceleration request is determined when the accelerator pedal is released from the accelerator pedal depressed state, the deceleration request of the driver can be determined most reliably.

[0040]

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. Although the engine 1 is composed of an internal combustion engine, it is not linked to the accelerator pedal 3 operated by the driver, but is disconnected therefrom, and
The opening includes a throttle valve 5 which is to be electronically controlled, the throttle valve 5 to the target throttle opening TVO ^* by the rotational position corresponding to the step motor 4 to a target throttle opening (TVO ^*) commanded by hand,
It is assumed that the output of the engine 1 can be controlled by factors other than the operation of the accelerator pedal.

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.

In order to change the speed 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 relatively moved closer to the other fixed flange. or narrow the V groove width Te, so as to be spread V groove width was separated, the two movable flanges, the target gear ratio (i ^*) primary pulley pressure from the hydraulic actuator 12 which operates in response to the command P _pri and secondary pulley pressure 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 speed 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 a rotation sensor 18, a signal from a vehicle speed sensor 19 for detecting a vehicle speed VSP, and a signal from a deceleration sensor 20 for detecting a deceleration G of the vehicle are input.

The controller 13 uses these input information based on the input information.
And a continuously variable transmission as shown in a functional block diagram in FIG.
2 shift control and engine 1 throttle opening control
The driving of the vehicle targeted by the present invention is performed as follows.
Execute force control. The required axle driving force calculation unit 21
The accelerator opening APS detected by the sensor 14 and the sensor
For example, based on the vehicle speed VSP detected by the
According to the method described in Japanese Unexamined Patent Publication No. Hei 7-172217.
The minimum necessary requirements according to the driving conditions and running conditions of the vehicle.
Axle drive force T_SAsk for. On the other hand, axle rotation speed calculation unit 2
2 is the secondary rotational speed N detected by the sensor 18
_secIn other words, the output speed of the transmission
Gear ratio of gear set 10 (final drive gear ratio) i_F
, The current axle speed N _SAsk for
You. Then, the requested horsepower calculation unit 23
Required axle driving force T determined _SAnd axle speed N_SMultiplication with
Required horsepower HP_SIs calculated.

The control in the target value computing unit 24, based on the characteristic diagram of the engine illustrated in FIG. 9 obtained in advance by experiments or the like, the engine speed N for generating the required horsepower HP _S calculated above at the lowest fuel consumption target value of _e N _e ^* and (a torque in this case) the engine output T _e target value T _e ^*
Then, the transmission target input rotation speed for drive control (drive control target primary rotation speed) _NpriS corresponding to the target engine speed N _e ^* is _calculated . Here, FIG. 9, 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,
The equal horsepower line β at which the output horsepower is the same is shown, and the minimum fuel consumption line connecting the points at which the fuel consumption rate is the best on each isohorsepower line β is shown by δ. In FIG. 9,
When the intersection between the required horsepower HP 1 present equal horsepower line β and minimum fuel consumption line corresponding to the _S [delta] is assumed to be Z point in Figure 9 for example, the target engine rotation for generating the request horsepower HP _S Lowest mileage The number _Ne ^* and the target engine output _Te ^* can be obtained as scale values respectively lowered from the point Z to the horizontal axis and the vertical axis as shown in FIG. In a vehicle with a continuously variable transmission, the torque converter 6 is in a lock-up state in which input and output elements are directly connected for most of the time during power transmission. target engine input rotational speed N _pris speed N _e
^* Will be treated as the same value.

The drive control transmission target input rotation speed _NpriS is input to a transmission target input rotation speed selection unit 27, and the vehicle target deceleration detected by the sensor 18 is separately provided from the transmission target input rotation speed selection unit 27. The deceleration control transmission target input speed N _priG obtained by the deceleration control unit 28 that performs deceleration control as described in, for example, Japanese Patent Application Laid-Open No. Hei 9-112682 so that G becomes a predetermined deceleration is _calculated . input. The transmission target input speed selection unit 27 responds to the output signal of the deceleration request determination unit 29 that determines whether the driver is requesting deceleration of the vehicle based on the accelerator opening APS detected by the sensor 14, and performs deceleration. At the time of request determination, the position becomes a solid line, and the deceleration control transmission target input speed N _priG is set to the transmission target input speed N _pri ^*. the rotational speed N _pris is to the transmission target input rotational speed N _pri ^*.

The deceleration request judging section 29 for judging whether or not the driver is requesting deceleration of the vehicle judges the deceleration request when the accelerator pedal is depressed from the depressed state to the released state. Is preferably not synchronized with the switching from the deceleration control to the drive control, but is synchronized with the end of the deceleration control.

The transmission target input rotation speed N _pri ^* is input to a target transmission ratio calculation unit 25, and the calculation unit 25 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.
^* , That is, the speed change control is performed so that the target input rotation speed _Npri ^* is achieved.

On the other hand, the drive control target engine output _Te ^* from the control target value calculation unit 24 is input to the drive control target throttle opening calculation unit 26, which calculates the drive control target engine output. enter the target throttle opening degree selection unit 31 obtains the output T _e ^* is the drive control target throttle opening TVO _S, such as those generated, apart from this target throttle opening degree selection unit 31, a minimum throttle opening degree setting section 3
The target throttle opening for deceleration control set in Step 2.
Entered, for example, a minimum throttle opening TVO _G corresponding to the throttle opening fully closed. Note that the minimum throttle opening TVO
_G does not necessarily have to correspond to fully closed, and may be a fixed value less than the set throttle opening.

The target throttle opening selector 31 is responsive to an output signal of the deceleration request determining unit 29, a minimum throttle opening TVO _G is a deceleration control target throttle opening degree becomes the solid line position when the deceleration request determining Target throttle opening TV
And O ^*, in which the target throttle opening TVO ^* drive control target throttle opening TVO _S becomes broken line position if not deceleration request. The target throttle opening TVO ^* thus determined is output to the step motor 4 as shown in FIG. 1, and the throttle valve 5 is controlled so that the target throttle opening TVO ^* is obtained.

According to the present embodiment as described above, when the deceleration request determination section 29 determines that the driver has not requested deceleration, the transmission target input speed selection section 27 is set to the position indicated by the broken line. the drive control transmission target input revolution speed N _pris a transmission target input rotational speed N _pri ^*, the target throttle opening drive control target throttle opening TVO _S target throttle opening selector 31 is in the broken line position TVO ^* . Therefore, except when a deceleration request is made, the shift control (N) of the continuously variable transmission is performed in such a manner that the required axle driving force T _S (required horsepower HP _S ) determined from the driving conditions and running conditions is generated at the minimum fuel consumption.
_priS ) and engine throttle opening control (TV
O _S ) is performed, and it is possible to reliably achieve both improvement in fuel efficiency and power performance without excess or deficiency.

When the deceleration request judging section 29 judges that the driver is requesting deceleration, the transmission target input rotation speed selection section 27 is set to the solid line position and the deceleration control transmission target input. The rotation speed N _priG is _changed to the transmission target input rotation speed N _pri
^* And then, for the minimum throttle opening TVO _G target throttle opening degree selection unit 31 is a throttle opening for the deceleration control is the solid line position and the target throttle opening TVO ^*. Deceleration request this purpose, at first, the deceleration control unit 28 instead of the drive control, obtains a deceleration control transmission target input revolution speed N _{pr iG} as vehicle deceleration G becomes a predetermined deceleration,
Simultaneously performs shift control to the deceleration control the continuously variable transmission to be achieved, and controls the throttle opening (engine output) to the minimum throttle opening TVO _G set at the minimum throttle opening degree setting section 32 As a result, the following effects can be obtained.

That is, when the deceleration request is determined, the drive
Transition from force control to deceleration control via shift control
Thus, it is possible to realize a control that matches the deceleration request. So
At this time, the throttle opening (engine output)
Rotor opening TVO _GAt the time of deceleration request
However, the target throttle opening (engine output)
Will be determined explicitly and satisfy the above requirements.
During the deceleration control.
The intake resistance of the engine is kept unchanged, and the
Interference can also be avoided. In addition, during deceleration control
Since the engine output does not increase suddenly,
The shock at the time of fuel recovery
There is no problem in that

In addition, since the deceleration control is realized by the shift control of the continuously variable transmission as described above, the deceleration control is performed in a control range more than when the engine output control such as the throttle opening control is performed. And the effect of preventing the shock at the time of fuel recovery accompanying re-acceleration from increasing is further ensured.

[0055] Figure 3 shows another embodiment of the present invention, the target engine drive control in this embodiment the output T _e
^{* And the} drive control transmission target input rotation speed _NpriS are determined as follows, unlike the above-described embodiment. The required minimum axle driving force T _S obtained by the required axle driving force calculating section 21 based on the accelerator opening APS and the vehicle speed VSP is input to the transmission target input rotation speed calculating section 33. Further, the vehicle speed detection value VS from the sensor 19
Enter P.

The transmission target input speed calculating section 33 uses a map corresponding to, for example, the data shown in FIG. 11 obtained from the required axle driving force T _S and the vehicle speed VSP based on the characteristic diagram of the engine as follows. to obtain the target value N _e ^* of the engine speed N _e for generating a current vehicle speed VSP under the required transaxle force T _S at the lowest fuel consumption, then corresponding to the target engine speed N _e ^* Drive control transmission target input rotation speed (drive control target primary rotation speed)
_{Find NpriS} .

Here, the data of FIG. 11 will be described. This data is obtained from the characteristic diagram of the engine shown in FIG. 9 as follows, and is obtained from the vehicle speed VSP, the axle driving force T _S, and the engine speed N _e. And the relationship. FIG. 9 has already been described above,
And 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,
Further, the output horsepower is shown as an equal horsepower line β, and the minimum fuel consumption line connecting the points at which the fuel consumption rate becomes the best on each of the equal horsepower lines β is shown as δ. As shown in FIG. 10, the individual points on the minimum fuel consumption line δ shown in FIG.
The _e to the vehicle speed VSP, also noted moves on a two-dimensional coordinate by replacing the engine output (torque) T _e the axle drive force T _S, the vehicle speed VSP and the engine output (torque) of the lowest fuel consumption per transmission ratio of T _e When the combination is obtained, the combination is as shown in FIG.

The engine speed is plotted on the characteristic diagram for each speed ratio.
Rotation speed N_ePlotting the points at which
Engine rotation speed N_eIn the case of, the thing shown by A in FIG.
And connecting these points, the engine speed N_eEvery
Vehicle speed VSP and axle driving force T_SDiagram showing the relationship
9 can be represented by a line as shown in FIG.
it can. In FIG. 11, for convenience, the engine speed is shown.
N_eTo the target engine speed N_e ^*Notation, and
Axle driving force T_STo the target axle driving force (same symbol T_SIndicated by
). The vehicle speed VSP and the target axle drive
Power T_SAnd the target engine speed N_e ^*Express the relationship with
According to the data, the current vehicle speed VSP and the target axle driving force T
_SIs a combination corresponding to point Z, for example.
To explain the case, the target vehicle under the vehicle speed VSP
Shaft driving force T_SEngine for generating fuel with minimum fuel consumption
Rotation speed N_e ^*Is related to the line passing through the point Z in FIG.
Parameter value (engine speed)
it can. For vehicles with a continuously variable transmission, power is being transmitted.
For most of the time, the torque converter 6 is connected between the input and output elements.
Because it is in the lockup state that is directly connected,
In an embodiment shown in FIG.
Control transmission target input rotation speed (drive control target primer
Re-rotation speed) N_priSTo the target engine speed N_e ^*The same value for
Shall be treated as

The drive control transmission target input rotation speed N _priS retrieved as described above is determined by the transmission target input rotation speed N _PRIG together with the deceleration control transmission target input rotation speed N _PRIG obtained by the deceleration control unit 28. The data is input to the selection unit 27. The transmission target input speed selection unit 27 responds to the output signal of the deceleration request determination unit 29 as in the embodiment shown in FIG. an input rotational speed N _PriG the transmission target input rotational speed N _pri ^*, the deceleration demand is unless dashed position and turned by the drive control transmission target input revolution speed N _{pr iS} transmission target input revolution speed N
_pri ^* .

On the other hand, in this embodiment, the axle rotation
The number operation unit 22 performs the secondary rotation as in FIG.
Number (transmission output speed) N_secThe final drive
Gear ratio of final set 10 (final drive gear ratio) i_Fso
Axle rotation speed N obtained by division _SThe wheel drive system target gear ratio
The data is input to the calculation unit 34. The operation unit 34 is provided with the drive
Control transmission target input rotation speed N_priSIs the axle speed N_STo
Divided by the wheel drive system target gear ratio i_T ^*Ask for this
Is input to the drive control target engine output calculation unit 35.
The calculating unit 35 is configured to drive the requested axle from the calculating unit 21.
Force T_SIs also input, and the required axle driving force T_SThe wheel drive
Dynamic system target gear ratio i_T ^*For drive control by dividing by
Target engine output (torque) T_e ^*Ask for.

The target engine output _Te ^* for drive control is input to the target throttle opening calculator 26 for drive control.
The arithmetic unit 26 as in the Figure 2, and inputs the determined drive control target throttle opening TVO _S, such as drive control target engine output T _e ^* is generated in the target throttle opening degree selection unit 31. This target throttle opening selector 3
It is separately input the minimum throttle opening setting unit 32 is a deceleration control throttle opening set in, even the smallest throttle opening TVO _G, for example corresponding to the throttle opening fully closed to 1. And the target throttle opening selection section 31
Is responsive to the output signal of the deceleration request determining unit 29, a minimum throttle opening TVO _G is a throttle opening for the deceleration control becomes solid line position to the target throttle opening TVO ^* during deceleration request determining, during deceleration request Otherwise a broken line position to the driving control target throttle opening TVO _S and the target throttle opening TVO ^*.

Therefore, in the embodiment shown in FIG.
For Determination of the drive control target engine output T _e ^* and the drive control for the transmission target input revolution speed N _pris is only different from that of FIG. 2, otherwise the same as in FIG. 2, similar to the above The operation and effect can be obtained, and the intended purpose can be achieved.

[0063] Note that any in the above embodiment two, the minimum throttle opening TVO _G from the minimum throttle opening setting unit 32 when the deceleration demand is determined by the determination unit 29
Although it was decided to the target throttle opening TVO ^*, in this case, during the deceleration request determining by the discrimination unit 29, the throttle opening degree due to the essential dead zone for determining the error prevention is not yet minimum throttle opening TVO _G As a result, the throttle opening is rapidly reduced by the dead zone,
The change in engine output is not smooth. FIG. 4 shows that in order to solve this problem, an APS → TVO unit conversion unit 36 is provided in place of the minimum throttle opening setting unit 32, where the accelerator opening detection value APS is converted into a throttle opening to convert the throttle opening. In this embodiment, a value TVO _APS is obtained and used as a target throttle opening TVO ^* when a deceleration request is determined.

In the present embodiment, although the dead zone is set in the deceleration request discriminating section 29 to prevent a judgment error, the discriminating section 29 is decelerated before the throttle opening is completely closed. request despite being configured to determine, the prevents the throttle opening is abruptly once to the minimum throttle opening TVO _G during the determination, the deceleration request determining when the throttle opening is the accelerator opening The converted throttle opening TVO _APS corresponding to the detected value (APS) is used, and the change in the engine output can be made smooth. In order to convert the accelerator opening detection value APS into a throttle opening in light of this purpose, it is preferable that the accelerator opening detection value APS and the throttle opening conversion value TVO _APS be made to correspond one to one. Needless to say.

[0065] Also any in FIGS. 2 and 3, when the deceleration request by the determination unit 29 is determined to the minimum throttle opening TVO _G from the minimum throttle opening setting unit 32 to the target throttle opening TVO ^* However, instead of this, at the time of deceleration request determination as shown in FIGS. 5 and 6, a minimum engine output such that the throttle opening is fully closed is commanded, and the target throttle opening TVO ^* is obtained from this. Even in this case, it is possible to achieve the same operation and effect as in the above-described embodiments.

[0066] Figure 5 also obtains the definitive when a similar manner the drive control target engine output T _e ^* and the drive control for the transmission target input revolution speed N _pris 2, provided the minimum engine power setting unit 41, thereby The minimum engine output _{TeG at} which the throttle opening is fully closed is set as the target engine output for deceleration control, and this minimum engine output _TeG is input to the target engine output selector 42. The target engine output selector 42 receives the drive control target engine output _Te ^* obtained by the control target value calculator 24 as described above with reference to FIG. In this way, it responds to the output signal of the deceleration request determination section 29. In other words, the selection unit 42 sets the minimum engine output _TeG , which is the target engine output for deceleration control, to the target engine output _Te0 ^* when the deceleration request is determined, and the dashed line position when no deceleration request is made. the control target engine output T _e ^* in which the target engine output T _e0 ^*.

The minimum engine output _TeG need not necessarily correspond to the fully closed throttle, but may be a fixed value that is less than the set throttle opening.

The target engine output _Te0 ^* from the target engine output selector 42 is input to the target throttle opening calculator 43, and the calculator 43 generates the target engine output _Te0 ^* determined as described above. The target throttle opening TVO ^* is calculated and output to the step motor 4 shown in FIG.
The opening degree is controlled to be O ^* . Also in the present embodiment, when the deceleration request is determined, the deceleration control by the block 28 is performed through the shift control of the continuously variable transmission, and at the same time, the throttle opening degree control such that the engine output becomes the minimum engine output _TeG is performed. As a result, the same operation and effect as in the embodiment shown in FIGS. 2 and 3 can be achieved.

[0069] Figure 6, with respect to those seeking definitive when Likewise drive control target engine output T _e ^* and the drive control for the transmission target input revolution speed N _pris 3, by applying the same concept as in FIG. 5 An embodiment in which a minimum engine output setting unit 41, a target engine output selection unit 42, and a target throttle opening calculation unit 43 similar to those in FIG. In the present embodiment, the minimum engine output setting unit 41 sets the minimum engine output _TeG corresponding to the throttle fully closed.
Is set as the target engine output for deceleration control, and the target engine output selection unit 42 responds to the output signal of the deceleration request determination unit 29, and when the deceleration request is determined, the target engine output selection unit 42 becomes the solid line position and sets the minimum deceleration control target engine output. The engine output _TeG is set to the target engine output _Te0 ^*, and unless a deceleration request is made, the _position is _indicated by a broken line, and the drive control target engine calculated by the drive control target engine output calculator 35 as described above with reference to FIG. the output T _e ^* and target engine output T _e0 ^*.

The target engine output _Te0 ^* from the target engine output selector 42 is input to a target throttle opening calculator 43, which generates the target engine output _Te0 ^* determined as described above. The target throttle opening TVO ^* is calculated and output to the step motor 4 shown in FIG.
The opening degree is controlled to be O ^* . Also in the present embodiment, at the same time when the deceleration control by the deceleration control unit 28 is performed via the shift control of the continuously variable transmission when the deceleration request is determined,
Since the throttle opening control is performed so that the engine output becomes the minimum engine output _TeG , the same operation and effect as in the embodiment shown in FIGS. 2 and 3 can be achieved.

FIG. 7 is a flowchart in the case where the microcomputer performs the throttle opening control and the shift control in FIGS. 2 and 3. First, in step 51, it is determined whether or not the accelerator opening APS is 0 to determine whether a deceleration request is made. Is determined. In step 52 if there is a deceleration request, the target throttle opening TVO of the drive control for the target throttle opening TVO _S obtained in as in FIG. 2 and FIG. 3
^* , Which is output to the step motor 4 shown in FIG. 1 to set the throttle valve 5 to the target throttle opening TVO ^*.
The opening is controlled so that Next, in step 53,
Similarly, the drive control transmission target input rotation speed _NpriS obtained as in FIGS. 2 and 3 is _replaced with the transmission target input rotation speed _Npris.
pri ^* .

[0072] When it is determined that there is a deceleration request in step 51, in step 54, the target throttle opening the minimum throttle opening TVO _G is a target throttle opening for deceleration control obtained in as in FIG. 2 and FIG. 3 The degree TVO ^* is output to the step motor 4 shown in FIG.
The opening degree is controlled to be O ^* . Next, in step 55, the deceleration control transmission target input rotation speed N _{priG for} making the vehicle deceleration _equal to the predetermined deceleration is _calculated as shown in FIGS. 2 and 3. The number is _Npri ^* .

[0073] In step 56, by dividing the above manner defined and the transmission target input rotational speed N _pri ^* at step 53 or 55 in the transmission output speed N _sec, the transmission target input revolution speed N _pri ^The target speed ratio i ^* corresponding to ^* is obtained and output to the hydraulic actuator 12 shown in FIG. 1 so that the continuously variable transmission 2 achieves the target speed ratio i ^* , that is, the target input rotation speed _Npri ^*. Is controlled so as to achieve the above.

As described above, in step 51, the number of drivers is reduced.
If it is determined that the speed is not requested, the process proceeds to step 52.
Drive control target throttle opening TVO_SGoal slot
TRU opening TVO^*And at step 53
Drive control transmission target input speed N_priSThe transmission target
Input speed N_pri ^*Therefore, except when deceleration is requested,
Required horsepower HP obtained from driving conditions and running conditions_S(See Figure 2
) And required axle driving force T_S(See Fig. 3))
Shift control of a continuously variable transmission in such a manner as to generate
(N_priS) And engine throttle opening control (TV
O _S) Will be implemented to improve fuel efficiency and
Power performance can be reliably achieved.

[0075] Thus, if it is determined that the driver in step 51 is requesting a deceleration, a minimum throttle opening TVO _G is a deceleration control throttle opening and the target throttle opening TVO ^* at step 54 Along with
In step 55, in order to set the deceleration control transmission target input speed N _priG to the transmission target input speed N _pri ^* ,
At the time of the deceleration request, the deceleration control is performed so that the vehicle deceleration becomes a predetermined deceleration through the shift control of the continuously variable transmission by the latter, and the engine is controlled to the minimum throttle speed through the throttle opening control by the latter. will be fixed to an opening TVO _G, it is possible to achieve the same effects as described above per FIGS.

FIG. 8 is a flowchart in the case where the throttle opening control and the shift control in FIGS. 5 and 6 are executed by the microcomputer. First, in step 61, it is determined whether or not the accelerator opening APS is 0 to determine whether or not a deceleration request is made. Is determined. In step 62 if there is a deceleration request, the drive control target engine output T _e ^* determined to as a target engine output T _e0 ^* in Figures 5 and 6,
Further, in step 63, the drive control transmission target input rotation speed N _priS also obtained as shown in FIGS. 5 and 6 is set as the transmission target input rotation speed N _pri ^* .

In step 61, it is determined that the request is a deceleration request.
5 and FIG. 6 in step 64.
To reduce the throttle opening to a fully closed position.
Minimum engine output as target engine output for speed control
T_eGTo the target engine output T_e0 ^*And step 65
At the same time as in FIG. 5 and FIG.
Also, reduce the vehicle deceleration so that it becomes the predetermined deceleration.
Speed control transmission target input speed N_priGThe transmission target
Power speed N_pri ^*And In step 66,
The target set as above in step 62 or 64
Engine power T_e0 ^*Target throttle opening to generate
Degree TVO^*, And this is used as the step motor 4 shown in FIG.
And the throttle valve 5 is set to the target throttle opening T
VO^*While controlling the opening so that
Or 65, the transmission target input time determined as described above.
Number of turns N _pri ^*Is the transmission output speed N_secDividing by
As a result, the transmission target input speed N_pri ^*Goals corresponding to
Transmission ratio i^*From the hydraulic actuator shown in FIG.
To the target speed ratio i.^*Achieved
That is, the target input rotational speed N_pri ^*Is achieved
The gear shifting control is performed as follows.

According to the above, the number of drivers is reduced in step 61.
If it is determined that the speed is not requested, the process proceeds to step 62.
And the target engine output T for drive control_e ^*The goal engine
Output T_e0 ^*And at step 63
Your transmission target input speed N _priSThe transmission target input rotation
Number N_pri ^*Operating conditions except when deceleration is requested
Required horsepower HP determined from driving conditions_S(See Fig. 5)
Axle drive force T_S(See Fig. 6)) with minimum fuel consumption
Control of the continuously variable transmission (N_priS)and
Engine throttle opening control (target engine output T_e
^*Throttle opening control corresponding to the
To ensure both fuel efficiency and power performance without excess or deficiency
Can be done.

If it is determined in step 61 that the driver is requesting deceleration, in step 64 the minimum engine output T such that the throttle opening is fully closed.
_eG is set as the target engine output _Te0 ^*, and step 6 is performed.
In 5, the deceleration control transmission target input speed N _priG for _{setting the} vehicle deceleration to the predetermined deceleration is set to the transmission target input speed N _pri ^*. The deceleration control is performed so that the vehicle deceleration becomes a predetermined deceleration through the shift control of the continuously variable transmission, and the engine is fixed at the minimum engine output _TeG through the latter throttle opening control. Figure 5
The same operation and effect as those in the case of FIG. 6 can be obtained.

[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 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, showing still another embodiment of the present invention.

FIG. 7 is a flowchart in a case where a shift control and a throttle opening control in FIGS. 2 and 3 are executed by a microcomputer.

FIG. 8 is a flowchart in a case where the shift control and the throttle opening control in FIGS. 5 and 6 are executed by a microcomputer.

FIG. 9 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. 10 is a diagram when the minimum fuel consumption line is rewritten as a relationship diagram between vehicle speed and axle driving force for each gear ratio.

FIG. 11 is a speed change pattern diagram of the continuously variable transmission shown as a diagram connecting points on the diagram of FIG. 10 at which the input rotation speed becomes equal for each speed ratio.

[Explanation of symbols]

 Reference Signs List 1 engine (internal combustion 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 20 Vehicle deceleration 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 calculator 26 Drive control target throttle opening calculator 27 Transmission target input speed selection unit 28 Deceleration control unit 29 Deceleration request discriminator 31 Target throttle opening selector 32 Minimum throttle opening setting unit 33 Transmission target input speed calculator 34 Wheel drive system target gear ratio calculator 35 Drive control target engine output calculator 36 APS → TVO unit converter 41 Minimum engine output setting unit 42 Target engine output selector 43 Target throttle opening calculator

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshinori Iwasaki 2 Nissan Motor Co., Ltd., Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa

Claims (9)

[Claims] 1. A vehicle equipped with a power train which is a combination of an engine whose output can be arbitrarily changed by a factor other than the operation of an accelerator pedal and a continuously variable transmission, wherein the vehicle has a driving state and running conditions which are different from each other. A combination of a target engine speed and a target engine output for realizing the determined required axle driving force is determined, and the speed of the continuously variable transmission is controlled so as to be a transmission target input speed corresponding to the target engine speed. ,
A driving force control device for a vehicle for controlling an output of an engine so as to attain the target engine output, wherein a request for deceleration of the vehicle is determined from a driving operation, and when the request for deceleration is determined, the target engine speed is reduced by a predetermined deceleration. A driving force control device for a vehicle, characterized in that the target engine output is fixed or limited. 2. The driving force control device for a vehicle according to claim 1, wherein the target engine output at the time of the deceleration request determination is set to be less than a set output. 3. The vehicle driving force control device according to claim 2, wherein the target engine output at the time of the deceleration request determination is set to a minimum output. 4. The system according to claim 1, wherein when the engine is an internal combustion engine, the target engine output is given as a target engine torque or a target throttle opening. Vehicle driving force control device. 5. The vehicle driving force control device according to claim 4, wherein the target engine output at the time of the deceleration request determination is set to a throttle opening fully closed command. 6. The vehicle according to claim 4, wherein the target engine output at the time of determining the deceleration request is a throttle opening corresponding to an accelerator pedal depression amount converted from an accelerator pedal depression amount. Driving force control device. 7. The driving force control device for a vehicle according to claim 6, wherein an accelerator pedal depression amount and a throttle opening are made to correspond to each other on a one-to-one basis in the conversion. 8. The driving force control device for a vehicle according to claim 1, wherein the deceleration request determination is performed based on an accelerator pedal operation. 9. The driving force control device for a vehicle according to claim 8, wherein a time when the accelerator pedal is released from an accelerator pedal depressed state is determined to be a deceleration request.