JP3661411B2 - Vehicle driving force control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a driving force control apparatus for a vehicle, in which driving force characteristics can be switched as desired.
[0002]
[Prior art]
As a conventional technique for switching the driving force characteristics of a vehicle as desired, for example, as described on page C-20 of “New Model Car Description (Supplement Edition II) Nissan Primera, Primera Camino (P11 Type)”, When selecting the sports driving range (Ds range), the minimum value of the reduction ratio of the continuously variable transmission (CVT) is limited with respect to the driving range (D range), thereby preventing engine braking and accelerator operation at a low accelerator opening. There is one that improves the driving performance at the time of high load such as driving on an uphill / downhill road or so-called sports driving by improving the gain of the driving force.
[0003]
[Problems to be solved by the invention]
However, in the vehicle driving force control device in which the target driving force is set from the atacel opening (throttle opening) and the vehicle speed, and the reduction ratio and the engine torque are controlled according to the target driving force, In the situation where the target driving force determined from the accelerator opening and the vehicle speed is the same only by limiting the minimum value of the reduction ratio in the Ds range as in the above prior art, the driving force for the accelerator operation is the D range. And since it does not change between Ds ranges, malfunctions, such as an engine brake not working, will arise.
[0004]
An object of the present invention is to provide a vehicle driving force control device that can select a desired driving force characteristic from among a plurality of driving force characteristics corresponding to various settings.
[0005]
[Means for Solving the Problems]
To achieve the above object, a vehicle driving force control apparatus according to claim 1 of the present invention includes 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 and vehicle speed. Target input speed calculation means for calculating a target input speed corresponding to the target reduction ratio of the transmission, and target engine torque calculation means for calculating target engine torque from the target driving force and the actual reduction ratio of the transmission; In the vehicle driving force control apparatus that controls the engine torque in accordance with the target engine torque, a normal mode, which is a plurality of characteristic modes related to the driving force, and a target driving force with respect to the normal mode. big have on the power mode and the normal mode and at least one of the target driving force is small snow mode, either from the plurality of characteristic modes of Mode selection means for selecting One of the characteristic mode, a target driving force characteristic switching means for switching the characteristics of the target driving force in response to an output of said mode selecting means, the target drive has been switched its properties by the target driving force characteristic switching means wherein a target input revolution speed calculating means, the target input rotational speed of the target input rotational speed calculation means according to an output of said mode selecting means, the normal mode for calculating the target input rotational speed of the transmission from the force and the vehicle speed When the power mode with a large target driving force is selected, the minimum value of the target input rotational speed is limited, and when the snow mode with a small target driving force with respect to the normal mode is selected, the target input and comprising an input rotation speed limiting means for limiting the maximum rotational speed Ri formed, the power mode further changes of the accelerator opening degree than the normal mode A large mode change of the target drive force against the snow mode is further characterized in that than the normal mode is small mode of change of the target driving force to the change in the accelerator opening.
[0006]
The vehicle driving force control apparatus according to claim 2 of the present invention is characterized in that the mode selection means selects a driving force characteristic mode in accordance with a driver's selection operation.
[0007]
According to a third aspect of the present invention, there is provided a vehicle driving force control device comprising gradient resistance detection means for detecting a weight gradient resistance of the vehicle, and the mode selection means when the detected value of the gradient resistance detection means is a predetermined value or more. Is configured to select the power mode.
[0008]
According to a fourth aspect of the present invention, there is provided a vehicle driving force control apparatus comprising slip ratio detection means for detecting a slip ratio of a drive wheel, and the mode selection means when the detected value of the slip ratio detection means is a predetermined value or less. Is configured to select the snow mode.
[0009]
【The invention's effect】
According to the vehicle driving force control apparatus of the present invention, the target driving force calculating means calculates the target driving force of the vehicle from the accelerator opening and the vehicle speed, and the target input rotation is calculated from the target driving force and the vehicle speed. The number calculating means calculates a target input rotational speed corresponding to the target reduction ratio of the transmission, the target engine torque calculating means calculates the target engine torque from the target driving force and the actual reduction ratio of the transmission, and the target engine When the vehicle driving force control device controls the engine torque in accordance with the torque, the normal mode, which is a plurality of characteristic modes related to the driving force, the power mode having a larger target driving force than the normal mode, and the normal In accordance with the output of the mode selection means for selecting one of the characteristic modes from at least one of the snow modes having a small target driving force relative to the mode, The force characteristic switching means switches the characteristic of the target driving force, and the target input rotational speed calculating means calculates the target input rotational speed of the transmission from the target driving force and the vehicle speed whose characteristics are switched by the target driving force characteristic switching means. In addition, according to the output of the mode selection means, the input rotation speed limiting means selects the target input rotation speed of the target input rotation speed calculation means, and the power mode having a larger target driving force than the normal mode is selected. In this case, the minimum value of the target input rotational speed is limited, and when the snow mode having a small target driving force with respect to the normal mode is selected, the maximum value of the target input rotational speed is limited.
[0010]
Therefore, according to the driving force control apparatus for a vehicle of claim 1 of the present invention, it is possible to obtain the driving force characteristic according to the setting of the characteristic mode.
[0011]
According to the vehicle driving force control apparatus of claim 1 of the present invention, when the power mode having a larger target driving force than the normal mode is selected, the minimum value of the target input rotational speed is limited. Therefore, the minimum reduction ratio of the transmission when the accelerator opening is small is limited, and the dynamic range of the driving force is widened in the region where the reduction ratio is larger (downshift) than usual. It is possible to deal with a wide range by engine brakes and the like.
[0012]
According to the vehicle driving force control apparatus of claim 1 of the present invention, the maximum value of the target input rotational speed is limited when the snow mode having a small target driving force with respect to the normal mode is selected. Therefore, the maximum reduction ratio of the transmission when the accelerator opening is large is limited, and the gain of the driving force for the accelerator operation in the region where the reduction ratio becomes smaller (upshift) than usual is increased. It can be lowered, and the safety on snow or the like that easily slips is improved.
[0013]
Further, according to the vehicle driving force control apparatus of claim 1 of the present invention, the power mode is a mode in which the change in the target driving force with respect to the change in the accelerator opening is larger than the normal mode, and the snow mode Is a mode in which the change in the target driving force with respect to the change in the accelerator opening is smaller than that in the normal mode, so that the vehicle corresponding to each of various driving conditions such as when driving on a mountain road or during sports driving with a high vehicle load. The driving force characteristic can be obtained, and the driving force characteristic of the vehicle corresponding to each of various running states such as when running on slippery snow can be obtained.
[0014]
According to the vehicle driving force control apparatus of the second aspect of the present invention, the driving force characteristic mode is selected in accordance with the driver's selection operation (for example, switch operation). The driver himself can select the driving force characteristics.
[0015]
According to the vehicle driving force control apparatus of the third aspect of the present invention, the mode selecting means selects the power mode when the detected value of the gradient resistance detecting means for detecting the weight gradient resistance of the vehicle is a predetermined value or more. Thus, the power mode is automatically selected according to the load of the vehicle, and the driving force characteristic according to the load can be switched without requiring a switching operation by the driver.
[0016]
According to the vehicle driving force control apparatus of the fourth aspect of the present invention, the mode selecting means selects the snow mode when the detected value of the slip ratio detecting means for detecting the slip ratio of the driving wheel is equal to or less than a predetermined value. Therefore, the snow mode is automatically selected according to the slip ratio of the drive wheel, and the driving force characteristic according to the slip ratio can be switched without requiring a switching operation by the driver.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0023]
FIG. 1 is a block diagram showing the basic configuration of a vehicle driving force control apparatus according to a first embodiment of the present invention. It is assumed that a vehicle to which the driving force control device of this embodiment is applied has a continuously variable transmission (CVT) as a transmission.
[0024]
As shown in FIG. 1, the vehicle driving force control apparatus of the present invention includes an accelerator sensor 1 that detects an accelerator opening (throttle opening) Aps, a vehicle speed sensor 2 that detects a vehicle speed Vsp, an accelerator opening Aps, D range target driving force calculation unit 3a that calculates D range target driving force tFd from vehicle speed Vsp, and Ds range target driving force calculation unit that calculates Ds range target driving force tFd from accelerator opening Aps and vehicle speed Vsp. 3b and the signal MODE indicating the range select state (D or Ds) of the range select switch 4 are input, and the output tFd of one of the D range target driving force calculator 3a and the Ds range target driving force calculator 3b is input. A characteristic switching unit 5 that selects the target input speed tNin corresponding to the target reduction ratio of the transmission is calculated from the target driving force tFd output from the characteristic switching unit 5 and the vehicle speed Vsp. Output from the target input speed calculation unit 6, the input speed limit unit 7 that limits the minimum input speed according to the range select signal D or Ds from the range select switch 4 and the vehicle speed Vsp, and the characteristic switching unit 5. And a target engine torque calculation unit 8 for calculating a target engine torque tTe from the target driving force tFd and the actual reduction ratio (actual transmission ratio) r of the transmission.
[0025]
In the above, the range select switch 4 corresponds to the mode selection means for selecting any one of the plurality of characteristic modes (D mode and Ds mode in the present embodiment) relating to the driving force, and the characteristic switching unit 5 Corresponds to the target driving force characteristic switching means for switching the characteristic of the target driving force according to the output (MODE) of the range select switch 4, and the shift schedule characteristics of the transmission according to the output (MODE) of the range select switch 4 This corresponds to the target reduction ratio characteristic switching means for switching the.
[0026]
FIG. 2 is a flowchart showing a control program for driving force control in the first embodiment of the present invention. In FIG. 2, first, at step 51, an accelerator opening Aps detected by the accelerator sensor 1, a vehicle speed Vsp detected by the vehicle speed sensor 2, and a signal MODE indicating the range select state of the range select switch 4 are input. In the next step 52, a target driving force map (see FIG. 1) of the target driving force calculator 3a or 3b is selected according to the signal MODE. In the next step 53, 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.
[0027]
In the next step 54, the target input rotational speed tNin is calculated 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, the target engine torque tTe is calculated from the target driving force tFd and the actual reduction ratio (actual transmission ratio) r of the transmission by tTe = tFd × r. In the next step 56, the target input rotational speed tNin and the target engine torque tTe are output.
[0028]
According to the present embodiment, a D mode (normal mode) or a Ds mode (for example, a power mode assuming sports driving or a snow mode assuming snow driving) which is a characteristic mode related to driving force based on a signal MODE from the range select switch 4. 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.
[0029]
FIG. 3 is a flowchart showing a control program for driving force control in the second embodiment of the present invention. In the present embodiment, it is assumed that gradient resistance detection means for detecting the weight gradient resistance of the vehicle is provided in addition to the configuration of FIG.
[0030]
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 weight gradient resistance Fg of the vehicle is detected by the gradient resistance detecting means. To detect. In the next step 63, it is determined whether or not the weight gradient resistance Fg is equal to or greater 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 searched from the target driving force map using the accelerator opening Aps and the vehicle speed Vsp as parameters. Thereafter, in steps 66 to 69, the same processing as in steps 53 to 56 in FIG. 2 is performed.
[0031]
According to the present embodiment, the power mode is selected when the weight gradient resistance Fg detected by the gradient resistance detection means is equal to or greater than the predetermined value FgSL, and the power mode is automatically selected according to the vehicle load. Therefore, the driving force characteristic corresponding to the load can be realized without requiring a switching operation by the driver.
[0032]
FIG. 4 is a block diagram showing the basic configuration of the vehicle driving force control apparatus according to the third embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. The difference of the present embodiment from the first embodiment is that the range select switch 4 is changed to slip detection means 9 for detecting the drive slip of the drive wheel, and the target drive force for Ds range as the target drive force calculation unit 3b. The calculation unit is changed to the snow mode target driving force calculation unit, and the characteristic switching unit 5 and the input rotation speed limiting unit 7 are changed as shown in FIG.
[0033]
FIG. 5 is a flowchart showing a control program for driving force control in the third embodiment of the present invention. In FIG. 5, first, in step 71, 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 72, the slip ratio Kslip of the drive wheel is determined by the slip ratio detecting means. To detect. 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. In this determination, if Kslip> KslipSL, the normal mode target driving force map is selected in step 74. If Kslip ≦ KslipSL, the snow mode target driving force map is selected in step 75. In step 76 subsequent to steps 74 and 75, 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. Thereafter, in steps 76 to 79, the same processing as in steps 53 to 56 in FIG. 2 is performed.
[0034]
According to the present embodiment, the snow mode is selected when the slip ratio Kslip detected by the slip ratio detection means is equal to or smaller than the predetermined value KslipSL, and the snow mode is automatically selected according to the slip ratio of the drive wheels. Therefore, the driving force characteristic corresponding to the slip ratio can be realized without requiring a switching operation by the driver.
[0035]
FIG. 6 is a block diagram showing the basic configuration of the vehicle driving force control apparatus according to the fourth embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. The modification of the present embodiment with respect to the first embodiment is that the signal MODE from the range select switch 4 is changed to add “snow”, and in addition to the target driving force calculation units 3a and 3b as target driving force calculation units. The change is made by adding the snow mode target driving force calculation unit 3c, and the characteristic switching unit 5 and the input rotation speed limiting unit 7 are changed as shown in the figure in response to the change. In the input rotation speed limiting unit 7 of the present embodiment, the maximum input rotation speed is limited in the snow mode as compared to the D range line on the left side in the figure, and the right D range in the figure in the power mode. The minimum input rotation speed is limited compared to the line.
[0036]
FIG. 7 is a flowchart showing a control program for driving force control in the fourth embodiment of the present invention. 7, first, at 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 select state of the range select switch 4 are inputted. In the next step 82, a target driving force map (see FIG. 1) of the target driving force calculator 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 stored. Select one of the following. 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, and in the next step 84, the target input speed is set using the target driving force tFd and the vehicle speed Vsp as parameters. tNin is calculated (map search).
[0037]
In the next step 85, the limit value NLIM of the target input speed tNin is retrieved from the target input speed limit table selected in the above step 82 using the vehicle speed Vsp as a parameter, and in the next step 86, it is determined whether or not it is in the snow mode. To do. In the normal mode or power mode in which this determination is NO, it is determined whether tNin <NLIM in step 87, and in the snow mode in which YES is determined, determination is made in step 88 as to whether tNin> NLIM. Do. If YES in steps 87 and 88, the minimum and maximum values of the target input speed tNin corresponding to the reduction ratio of the continuously variable transmission are set to the limit values by setting tNin = NLIM in step 89. Restrict to NLIM. If the determination in steps 87 and 88 is NO, step 89 is skipped and tNin is not limited. Thereafter, in steps 90 and 91, the same processing as in steps 55 and 56 in FIG. 2 is performed.
[0038]
According to the present embodiment, when the power mode is selected, the minimum value of the target input speed tNin corresponding to the speed reduction ratio of the transmission is limited to the limit value NLIM. Since the minimum input rotation speed of the transmission is limited and the reduction ratio becomes larger (downshift) than usual, the dynamic range of the driving force can be widened, so it can be used in a wider range for engine braking, etc. To be able to respond. Further, according to the present embodiment, when the snow mode is selected, the maximum value of the target input rotational speed tNin corresponding to the transmission reduction ratio is limited to the limit value NLIM. The maximum input speed of the transmission will be limited, and the reduction ratio will be smaller (upshift) than usual, so the gain of the driving force for the accelerator operation can be further reduced, and on slippery snow etc. Safety can be improved. It is easy to limit the reduction ratio according to the mode without combining the second or third embodiment and the fourth embodiment and requiring a driver's switching operation.
[Brief description of the drawings]
FIG. 1 is a block diagram showing the basic configuration of a vehicle driving force control apparatus according to a first embodiment of the present invention.
FIG. 2 is a flowchart showing a control program for driving force control in the first embodiment of the present invention.
FIG. 3 is a flowchart showing a control program for driving force control in a second embodiment of the present invention.
FIG. 4 is a block diagram showing the basic configuration of a vehicle driving force control apparatus according to a third embodiment of the present invention.
FIG. 5 is a flowchart showing a control program for driving force control in a third embodiment of the present invention.
FIG. 6 is a block diagram showing a basic configuration of a vehicle driving force control apparatus according to a fourth embodiment of the present invention.
FIG. 7 is a flowchart showing a control program for driving force control in a fourth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Acceleration sensor 2 Vehicle speed sensor 3a D range target driving force calculation part 3b Ds range target driving force calculation part 4 Range select switch 5 Characteristic switching part 6 Target input rotation speed calculation part 7 Input rotation speed restriction part 8 Target engine torque calculation Part

Claims (4)

Target driving force calculating means for calculating the target driving force of the vehicle from the accelerator opening and the vehicle speed;
A target input speed calculation means for calculating a target input speed corresponding to a target reduction ratio of the transmission from the target driving force and the vehicle speed;
In a vehicle driving force control device, comprising target engine torque calculating means for calculating a target engine torque from the target driving force and an actual reduction ratio of the transmission, wherein the engine torque is controlled according to the target engine torque. ,
A normal mode which is a plurality of characteristic modes related to driving force, and at least one of a power mode having a large target driving force with respect to the normal mode and a snow mode having a small target driving force with respect to the normal mode, Mode selection means for selecting any one of the plurality of characteristic modes;
Target driving force characteristic switching means for switching the characteristic of the target driving force in accordance with the output of the mode selection means;
The target input rotational speed calculating means for calculating the target input rotational speed of the transmission from the target driving force and the vehicle speed whose characteristics are switched by the target driving force characteristic switching means;
The target input rotational speed of the target input rotational speed calculation means according to an output of said mode selecting means, said target input rotational speed minimum value if the power mode target driving force to the normal mode is large is selected restricts, formed SQLDESC_BASE_TABLE_NAME This includes an input rotation speed limiting means for limiting the maximum value of the target input rotational speed when the snow mode target driving force is small is selected for the normal mode,
The power mode is a mode in which the change in the target driving force with respect to the change in the accelerator opening is larger than that in the normal mode,
The snow mode is a mode in which the change in the target drive force with respect to the change in the accelerator opening is smaller than that in the normal mode . 2. The driving force control apparatus for a vehicle according to claim 1 , wherein the mode selection means selects a driving force characteristic mode in accordance with a driver's selection operation. With a gradient resistance detecting means for detecting the weight gradient resistance of the vehicle, wherein the detection value of the gradient resistance detecting means is characterized in that said mode selecting means when a predetermined value or more has been to select the power mode Item 2. A driving force control apparatus for a vehicle according to Item 1 . Includes a slip ratio detecting means for detecting a slip ratio of the driving wheels, wherein the detected value of the slip ratio detecting means, characterized in that said mode selecting means when more than a predetermined value so as to select the snow mode Item 2. A driving force control apparatus for a vehicle according to Item 1 .

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