JPH11348606A - Vehicular driving force control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular driving force control device capable of selecting a desired driving force property out of a plurality of driving force properties associated with various settings. SOLUTION: This vehicular driving force control device is provided with target driving force computing parts 3a, 3b for computing the target driving force tFd of a vehicle by referring to an accelerator opening Aps obtained from an accelerator sensor 1 and vehicle speed Vsp obtained from a vehicle speed sensor 2; a target input engine speed computing part 6 for computing target input engine speed tNin associated with the target speed reducing ratio of a transmission by referring to the target driving force tFd and the vehicle speed Vsp ; a target engine torque computing part 8 for computing target engine torque tTe by referring to the target driving force tFd and an actual speed reducing ratio (r); a range selection switch 4 for selecting any one of the property modes (mode D, mode DS) related to driving force; and a property switching part 5 for selecting any one of the outputs from the target driving force computing parts 3a, 3b in accordance with an output signal MODE from the range selection switch 4.

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 a vehicle in which driving force characteristics can be switched as desired.

[0002]

2. Description of the Related Art As a prior art for switching the driving force characteristics of a vehicle as desired, for example, a description of a new vehicle manual (supplementary version)
II) Nissan Primera, Primera Camino (P11
Type), the driving range (Ds range) is selected when the sports driving range (Ds range) is selected.
Range), the minimum value of the reduction ratio of the continuously variable transmission (CVT) is limited, thereby improving the gain of the driving force for engine braking and accelerator operation at a low accelerator opening, and when traveling uphill or downhill. There is one that improves drivability under high load such as during sports running.

[0003]

However, in a vehicle in which a target driving force is set based on the atter cell opening (throttle opening) and the vehicle speed, a reduction ratio and an engine torque are controlled in accordance with the target driving force. In the driving force control device, in a situation where the target driving force determined from the accelerator opening and the vehicle speed becomes the same only by limiting the minimum value of the reduction ratio in the Ds range as in the above-described related art, Since the driving force for the accelerator operation does not change between the D range and the Ds range, problems such as ineffective engine braking occur.

[0004] It is an object of the present invention to provide a driving force control device for a vehicle, in which a desired driving force characteristic can be selected from a plurality of driving force characteristics corresponding to various settings.

[0005]

To achieve the above object, a vehicle driving force control apparatus according to a first aspect of the present invention comprises a target driving force calculating means for calculating a target driving force of a vehicle from an accelerator opening and a vehicle speed. And the target driving force or accelerator opening,
Target reduction ratio calculating means for calculating a target reduction ratio of the transmission from the vehicle speed; and target engine torque calculation means for calculating a target engine torque from the target driving force and a target reduction ratio or an actual reduction ratio of the transmission. A driving force control device for a vehicle, comprising: a mode selecting unit that selects any one of a plurality of characteristic modes relating to the driving force;
A target driving force characteristic switching means for switching a characteristic of a target driving force in accordance with an output of the mode selection means.

According to a second aspect of the present invention, there is provided a vehicle driving force control device, wherein the plurality of characteristic modes include a normal mode and a power mode in which a change in target driving force with respect to a change in accelerator opening is larger than that in the normal mode. It is characterized by having.

According to a third aspect of the present invention, in the vehicle driving force control apparatus, the plurality of characteristic modes include a normal mode and a snow mode in which a change in target driving force with respect to a change in accelerator opening is smaller than in the normal mode. It is characterized by having.

According to a fourth aspect of the present invention, in the driving force control apparatus for a vehicle, the mode selecting means selects a characteristic mode of the driving force in accordance with a selection operation by a driver.

According to a fifth aspect of the present invention, there is provided a driving force control device for a vehicle, comprising a gradient resistance detecting means for detecting a weight gradient resistance of the vehicle, wherein when a detected value of the gradient resistance detecting means is equal to or larger than a predetermined value. The power supply mode is selected by the mode selection means.

A vehicle driving force control apparatus according to a sixth aspect of the present invention includes a slip ratio detecting means for detecting a slip ratio of a driving wheel. The mode selecting means selects the snow mode.

According to a seventh aspect of the present invention, there is provided a vehicle driving force control apparatus including a target reduction ratio characteristic switching means for switching a transmission schedule characteristic of a transmission in accordance with an output of the mode selection means.

A vehicle driving force control apparatus according to an eighth aspect of the present invention is characterized in that the minimum value of the reduction ratio of the transmission is limited.

According to a ninth aspect of the present invention, there is provided a driving force control apparatus for a vehicle, wherein a maximum value of a reduction ratio of a transmission is limited.

[0014]

According to the vehicle driving force control device of the first aspect of the present invention, the target driving force of the vehicle is calculated from the accelerator opening and the vehicle speed, and the target driving force or the accelerator opening is calculated as follows:
A target reduction ratio of the transmission is calculated from the vehicle speed, and a target engine torque is calculated from the target driving force and the target reduction ratio or the actual reduction ratio of the transmission. Thus, the characteristics of the target driving force can be switched as desired in accordance with the output of the mode selecting means for selecting any one of the characteristic modes. Therefore, driving force characteristics according to the setting of the characteristic mode can be obtained.

According to a second aspect of the present invention, the plurality of characteristic modes selected by the mode selecting means include a normal mode and a target drive with respect to a change in accelerator opening more than the normal mode. Since the power mode in which the change in force is large is included, it is possible to obtain the driving force characteristics of the vehicle corresponding to each of various running states such as running on mountain roads and running sports where the vehicle load is high.

According to the vehicle driving force control apparatus of the third aspect of the present invention, the plurality of characteristic modes selected by the mode selecting means include a normal mode and a target drive with respect to a change in the degree of accelerator opening more than the normal mode. Since the snow mode in which the change in force is small is included, it is possible to obtain the driving force characteristics of the vehicle corresponding to each of various running states such as running on slippery snow.

According to the driving force control device for a vehicle of the fourth aspect of the present invention, the characteristic mode of the driving force is selected according to the driver's selection operation (for example, switch operation).
The driver himself / herself can select the driving force characteristics according to the driver's preference and judgment.

According to a fifth aspect of the present invention, when the detected value of the gradient resistance detecting means for detecting the weight gradient resistance of the vehicle is equal to or greater than a predetermined value, the mode selecting means sets the power mode. Since the selection is made, the power mode is automatically selected according to the load of the vehicle, and the driving force characteristic can be switched to the load without the need for the switching operation by the driver.

According to the driving force control apparatus for a vehicle of the present invention, when the detected value of the slip ratio detecting means for detecting the slip ratio of the driving wheels is equal to or less than a predetermined value, the mode selecting means sets the snow mode. Since the selection is made, the snow mode is automatically selected according to the slip ratio of the driving wheels, and the driving force characteristic can be switched to the slip ratio according to the slip ratio without requiring a switching operation by the driver. .

According to the vehicle driving force control apparatus of the present invention, the shift schedule characteristic of the transmission can be switched according to the output of the mode selecting means, and therefore, the shift according to the setting of the shift schedule. Properties can be obtained.

According to the vehicle driving force control apparatus of the eighth aspect of the present invention, the minimum value of the reduction ratio of the transmission is limited, so that the minimum reduction ratio of the transmission when the accelerator opening is small is used. Is limited, and the dynamic range of the driving force in a region where the reduction ratio is larger than usual (downshift) can be widened, and it is possible to cope with a wider range by an engine brake or the like.

According to the vehicle driving force control apparatus of the ninth aspect of the present invention, since the maximum value of the reduction ratio of the transmission is limited, the maximum reduction ratio of the transmission when the accelerator opening is large is used. Is reduced, the gain of the driving force for the accelerator operation in the region where the reduction ratio is smaller than usual (upshift) can be further reduced, and the safety on snow or the like where slip is likely to be improved.

[0023]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing a basic configuration of a vehicle driving force control device according to a first embodiment of the present invention. It is assumed that the vehicle to which the driving force control device of the present embodiment is applied has a continuously variable transmission (CVT) as a transmission.

As shown in FIG. 1, the vehicle driving force control apparatus of the present invention includes an accelerator sensor 1 for detecting an accelerator opening (throttle opening) Aps, a vehicle speed sensor 2 for detecting a vehicle speed Vsp, and an accelerator opening. D range target driving force calculation unit 3a for calculating D range target driving force tFd from degree Aps and vehicle speed Vsp, and Ds from accelerator opening Aps and vehicle speed Vsp.
A Ds range target driving force calculator 3b for calculating the range target driving force tFd, and a D range target driving force calculator 3a receiving a signal MODE indicating the range selection state (D or Ds) of the range select switch 4 are input. A characteristic switching unit 5 for selecting one of the outputs tFd of the target driving force calculating unit 3b for the Ds range and the target driving force tFd output from the characteristic switching unit 5 and the vehicle speed Vsp. A target input speed calculating unit 6 for calculating a target input speed tNin to be set, an input speed limiting unit 7 for limiting the minimum input speed according to the range select signal D or Ds from the range select switch 4 and the vehicle speed Vsp. A target engine torque tTe for calculating the target engine torque tTe from the target driving force tFd output from the characteristic switching unit 5 and the actual reduction ratio (actual transmission ratio) r of the transmission. Formed by and a calculating unit 8.

In the above, the range select switch 4
Corresponds to a mode selection means for selecting any one of a plurality of characteristic modes (D mode and Ds mode in the present embodiment) relating to the driving force. Target reduction ratio characteristic switching for switching target transmission force characteristics according to the output (MODE) of the range select switch 4 while corresponding to target driving force characteristic switching means for switching characteristics of the target driving force according to the output (MODE). It corresponds to the means.

FIG. 2 is a flowchart showing a control program for driving force control according to the first embodiment of the present invention.
In FIG. 2, first, in step 51, the accelerator opening Aps detected by the accelerator sensor 1, the vehicle speed Vsp detected by the vehicle speed sensor 2, and a signal MODE indicating the range selection state of the range selection switch 4 are input. In the next step 52, a target driving force map (see FIG. 1) of the target driving force calculation unit 3a or 3b is selected according to the signal MODE. In the next step 53, a target driving force tFd is retrieved from the target driving force map using the accelerator opening Aps and the vehicle speed Vsp as parameters.

In the next step 54, the target input rotational speed tNin is set using the target driving force tFd and the vehicle speed Vsp as parameters.
(In the example of FIG. 2, tNin is obtained by searching the map illustrated in FIG. 1). In the next step 55,
Target driving force tFd and actual reduction ratio of transmission (actual transmission ratio) r
, The target engine torque tTe is calculated by tTe = tFd × r. Then, in the next step 56, the target input rotational speed tNin and the target engine torque tTe are output.

According to the present embodiment, a D mode (normal mode) or a Ds mode (for example, a power mode assuming sports running or running on snow) as a characteristic mode relating to the driving force is assumed by a signal MODE from the range select switch 4. (Snow mode) is selected and the characteristic of the target driving force is switched, so that the driving force characteristic according to the setting of the characteristic mode can be realized.

FIG. 3 is a flowchart showing a control program for driving force control according to the second embodiment of the present invention.
In this embodiment, in addition to the configuration shown in FIG. 1, it is assumed that a gradient resistance detecting means for detecting a weight gradient resistance of the vehicle is provided.

In FIG. 3, first, in step 61, the accelerator opening Aps detected by the accelerator sensor 1 and the vehicle speed Vsp detected by the vehicle speed sensor 2 are input. In the next step 62, the gradient resistance detecting means detects the weight gradient of the vehicle. The resistance Fg is detected. In the next step 63, it is determined whether or not the weight gradient resistance Fg is equal to or more than a predetermined value FgSL. In this determination, if Fg ≧ FgSL, the power mode target driving force map is selected in step 64, and if Fg <FgSL, the normal mode target driving force map is selected in step 65. In step 66 following steps 64 and 65,
The target driving force tFd is retrieved from the target driving force map using the accelerator opening Aps and the vehicle speed Vsp as parameters. Hereinafter, in steps 66 to 69, steps 53 to 56 in FIG.
And performs the same processing.

According to the present embodiment, when the weight gradient resistance Fg detected by the gradient resistance detecting means is equal to or more than the predetermined value FgSL, the power mode is selected, and the power mode is automatically selected according to the load of the vehicle. Therefore, the driving force characteristics according to the load can be realized without requiring the driver to perform the switching operation.

FIG. 4 is a block diagram showing the principle configuration of a vehicle driving force control apparatus according to a third embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted. I do. The difference of the present embodiment from the first embodiment is that the range select switch 4 is changed to slip detecting means 9 for detecting the drive slip of the drive wheel, and the target drive force for the Ds range as the target drive force calculating unit 3b is used. The calculation unit has been changed to a snow mode target driving force calculation unit,
In response to the above change, the characteristic switching unit 5 and the input rotation speed limiting unit 7 are changed as shown in the figure.

FIG. 5 is a flowchart showing a control program for driving force control according to the third embodiment of the present invention.
In FIG. 5, first, at step 71, the accelerator opening Aps detected by the accelerator sensor 1 and the vehicle speed sensor 2
Then, in the next step 72, the slip ratio Ksli of the drive wheels is detected by the slip ratio detecting means.
Find p. In the next step 73, it is determined whether or not the slip ratio Kslip of the drive wheel is larger than a predetermined value KslipSL. If Kslip> KslipSL in this determination, a normal mode target driving force map is selected in step 74,
If Kslip ≦ KslipSL, a target driving force map for snow mode is selected in step 75. In step 76 following steps 74 and 75, accelerator opening Aps and vehicle speed V
The target driving force tFd is searched from the target driving force map using sp as a parameter. Hereinafter, in steps 76 to 79, the same processing as in steps 53 to 56 in FIG. 2 is performed.

According to this embodiment, when the slip ratio Kslip detected by the slip ratio detecting means is equal to or smaller than the predetermined value KslipSL, the snow mode is selected, and the snow mode is automatically selected according to the slip ratio of the driving wheels. As a result, the driving force characteristic according to the slip ratio can be realized without requiring the driver to perform the switching operation.

FIG. 6 is a block diagram showing the basic configuration of a vehicle driving force control apparatus according to a fourth embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted. I do. This embodiment is different from the first embodiment in that the signal MODE from the range select switch 4 is changed to add "snow", and the target driving force calculation unit is added to the target driving force calculation units 3a and 3b. That is, the change to add the snow mode target driving force calculation unit 3c is performed, and the characteristic switching unit 5 and the input rotation speed restriction unit 7 are changed as shown in the figure in response to the above change. In the input rotation speed limiting unit 7 of the present embodiment, the maximum input rotation speed is limited in the snow mode in comparison with the D range line on the left side in the drawing, and in the power mode, the D rotation range on the right side in the drawing is limited. The minimum input rotation speed is limited as compared with the line.

FIG. 7 is a flowchart showing a control program for driving force control according to the fourth embodiment of the present invention.
7, first, in step 81, the accelerator opening Aps detected by the accelerator sensor 1, the vehicle speed Vsp detected by the vehicle speed sensor 2, and the signal MODE indicating the range selection state of the range selection switch 4 are input. In the next step 82, a target driving force map (see FIG. 1) of the target driving force calculation unit 3a or 3b is selected according to the signal MODE, and a plurality of types of target input rotation speed limit tables stored in advance are selected. Is selected. In the next step 83, the target driving force tFd is searched from the target driving force map using the accelerator opening Aps and the vehicle speed Vsp as parameters. In the next step 84, the target input rotation speed is set using the target driving force tFd and the vehicle speed Vsp as parameters. tNin is calculated (map search).

In the next step 85, the limit value NLIM of the target input speed tNin is obtained from the target input speed limit table selected in step 82 using the vehicle speed Vsp as a parameter.
Is determined, and in a next step 86, it is determined whether or not the mode is the snow mode. In the case of the normal mode or the power mode in which this determination is NO, in step 87, tNin <NLIM
It is determined whether or not tNin> NLIM in step 88 if the snow mode is set.
If the determinations in steps 87 and 88 are YES, step 89 sets tNin = NLIM to set the minimum and maximum values of the target input rotational speed tNin corresponding to the reduction ratio of the continuously variable transmission to the limit values. Restrict to NLIM. If the determinations in steps 87 and 88 are NO, step 89 is skipped and tNin is not limited. afterwards,
In steps 90 and 91, the same processing as steps 55 and 56 in FIG. 2 is performed.

According to the present embodiment, when the power mode is selected, the minimum value of the target input speed tNin corresponding to the reduction ratio of the transmission is limited to the limit value NLIM. The minimum input speed of the continuously variable transmission is limited, and the reduction ratio becomes larger (downshift) than usual, so that the dynamic range of the driving force can be widened. It is possible to support a wider range.
According to the present embodiment, when the snow mode is selected, the maximum value of the target input speed tNin corresponding to the reduction ratio of the transmission is limited to the limit value NLIM.
The maximum input rotation speed of the transmission when ps is large is limited, and the reduction ratio becomes smaller than usual (upshift), so that the gain of the driving force with respect to the accelerator operation can be further reduced, and the slip can be reduced. It is possible to improve the safety on snow or the like, which is easy to perform. In addition, it is easy to combine the second or third embodiment and the fourth embodiment to limit the reduction ratio according to the mode without requiring a driver's switching operation.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of a vehicle driving force control device according to a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating a control program for driving force control according to the first embodiment of the present invention.

FIG. 3 is a flowchart illustrating a control program for driving force control according to a second embodiment of the present invention.

FIG. 4 is a block diagram showing a basic configuration of a vehicle driving force control device according to a third embodiment of the present invention.

FIG. 5 is a flowchart illustrating a control program for driving force control according to a third embodiment of the present invention.

FIG. 6 is a block diagram showing a basic configuration of a vehicle driving force control device according to a fourth embodiment of the present invention.

FIG. 7 is a flowchart illustrating a control program for driving force control according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Accelerator sensor 2 Vehicle speed sensor 3a D range target driving force calculation unit 3b Ds range target driving force calculation unit 4 Range select switch 5 Characteristic switching unit 6 Target input rotation speed calculation unit 7 Input rotation speed limitation unit 8 Target engine torque calculation Department

Claims (9)

[Claims] 1. A target driving force calculating means for calculating a target driving force of a vehicle from an accelerator opening and a vehicle speed, and a target for calculating a target reduction ratio of a transmission from the target driving force or the accelerator opening and the vehicle speed. A driving force control device for a vehicle, comprising: a reduction ratio calculating unit; and a target engine torque calculating unit configured to calculate a target engine torque from the target driving force and a target reduction ratio or an actual reduction ratio of the transmission. And a target driving force characteristic switching means for switching the characteristic of the target driving force in accordance with the output of the mode selecting means. A vehicle driving force control device characterized by the following. 2. The vehicle driving system according to claim 1, wherein the plurality of characteristic modes include a normal mode and a power mode in which a change in target driving force with respect to a change in accelerator opening is larger than that in the normal mode. Power control device. 3. The vehicle driving system according to claim 1, wherein the plurality of characteristic modes include a normal mode and a snow mode in which a change in a target driving force with respect to a change in an accelerator opening is smaller than that in the normal mode. Power control device. 4. The vehicle drive according to claim 1, wherein the mode selection means selects a characteristic mode of the driving force in accordance with a selection operation by a driver. Power control device. 5. The vehicle according to claim 1, further comprising a gradient resistance detecting means for detecting a weight gradient resistance of the vehicle, wherein the mode selecting means selects a power mode when a detected value of the gradient resistance detecting means is equal to or more than a predetermined value. The vehicle driving force control device according to claim 1 or 2, wherein: 6. A method according to claim 6, further comprising a slip ratio detecting means for detecting a slip ratio of the driving wheel, wherein the mode selecting means selects the snow mode when a detected value of the slip ratio detecting means is equal to or less than a predetermined value. 3. A method according to claim 1, wherein
A driving force control device for a vehicle according to claim 1. 7. The vehicle drive according to claim 1, further comprising a target reduction ratio characteristic switching unit that switches a shift schedule characteristic of the transmission according to an output of the mode selection unit. Power control device. 8. The driving force control device for a vehicle according to claim 2, wherein a minimum value of a reduction ratio of the transmission is limited. 9. The driving force control apparatus for a vehicle according to claim 3, wherein the maximum value of the reduction ratio of the transmission is limited.