JP2910877B2 - Vehicle power train control device and method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle power train control device and a power train control method.

[0002]

2. Description of the Related Art In recent years, the output torque of a power train has been increased due to the adoption of a large-displacement engine or the enhancement of the performance of an engine, and the torque that can be applied to a driving wheel tends to increase significantly. However, in general, when the torque applied to the driving wheels during acceleration is too large relative to the road surface friction coefficient (road surface μ), the slip ratio of the driving wheels excessively increases, and the running stability decreases due to the occurrence of spin or the like. There are problems such as inconveniences such as wear of tires and deterioration of fuel efficiency. To cope with this, the road surface μ is detected, the maximum possible torque transmission amount on the road surface μ is calculated, and the engine output is controlled so that the torque applied to the drive wheels does not exceed the maximum possible torque transmission amount. A vehicle that performs traction control has been proposed (Japanese Patent Application Laid-Open No. 60-147).
No. 546).

[0003]

However, in a vehicle in which such traction control is performed, the driving force that can be generated by the power train is controlled by itself, so that the power train can be fully utilized. There is a problem that can not be. The present invention has been made in order to solve the conventional problems described above, and in a vehicle equipped with a high-output power train, there are disadvantages such as a decrease in running stability, abrasion of tires, and a decrease in fuel efficiency. An object of the present invention is to provide a power train control device or control method capable of fully exhibiting the power train's ability without inviting it, and improving maneuverability or traveling performance.

[0004]

In order to achieve the above object, a first aspect of the present invention is to change an engine output characteristic in which two types of engine output characteristics of a normal mode and a sports mode are set for an accelerator operation amount. In a vehicle power train control apparatus provided with a system and mode switching means for performing the mode switching, when the accelerator operation amount is maximum, the maximum driving force (within the slip limit) in a state in which the driving wheels do not slip. While the normal mode engine output characteristic is set so that the maximum driving force is obtained, the maximum driving force within the slip limit is obtained when the accelerator operation amount is a predetermined intermediate value (intermediate accelerator operation amount), and When the accelerator operation amount is the maximum, the maximum driving force (maximum driving force outside the slip limit) can be obtained when the driving wheels slip. Engine output characteristic setting means for setting the sport mode the engine output characteristic to provide a power train control apparatus for a vehicle, characterized in that provided in the.

According to a second aspect of the present invention, in the vehicle power train control apparatus according to the first aspect, the engine output characteristic setting means determines the maximum driving force within the slip limit and the maximum driving force outside the slip limit on the maximum road surface on a practical road surface. While setting to correspond to friction (maximum road surface μ), road surface friction coefficient
Road surface μ detecting means for detecting (road surface μ), and engine output characteristic correcting means for correcting the maximum driving force within the slip limit and the maximum driving force outside the slip limit according to the road surface μ detected by the road surface μ detecting means. And a power train control device for a vehicle.

According to a third aspect of the present invention, in the vehicle power train control apparatus according to the second aspect, the engine output characteristic setting means determines whether the accelerator operation amount is a predetermined reference value smaller than the intermediate accelerator operation amount. A power train control device for a vehicle, wherein a normal mode engine output characteristic is set so that an acceleration (required acceleration) at which a cumulative frequency of acceleration data becomes a predetermined boundary value is obtained. I do.

According to a fourth aspect of the present invention, there is provided a power train control method for a vehicle in which two types of engine output characteristics of a normal mode and a sports mode are set for an accelerator operation amount so that the mode can be arbitrarily switched. Maximum driving force when the driving wheel does not slip when the accelerator operation amount is maximum (maximum driving force within the slip limit)
While the normal mode engine output characteristic is set so that the accelerator operation amount is a predetermined intermediate value (intermediate accelerator operation amount), the maximum driving force within the slip limit is obtained, and the accelerator operation amount is A power train control method for a vehicle, comprising: setting a sports mode engine output characteristic so that a maximum driving force (maximum driving force outside a slip limit) in a state in which a driving wheel slips at a maximum is obtained. I do.

According to a fifth aspect, in the power train control method according to the fourth aspect, the maximum driving force within the slip limit and the maximum driving force outside the slip limit correspond to maximum road surface friction (maximum road surface μ) on a practical road surface. The power train control method for a vehicle is characterized in that the road surface μ is detected and the maximum driving force within the slip limit and the maximum driving force outside the slip limit are corrected according to the road surface μ. .

According to a sixth aspect, in the power train control method according to the fifth aspect, when the accelerator operation amount is a predetermined reference value smaller than the intermediate accelerator operation amount,
A power train control method for a vehicle, characterized in that a normal mode engine output characteristic is set so that an acceleration (required acceleration) at which a cumulative frequency of acceleration data becomes a predetermined boundary value is obtained.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below.
As shown in FIG. 1, the vehicle WD is provided with a power train P, and the power train P substantially corresponds to the engine 1
, A torque converter 2 and an automatic transmission 3. After the output torque of the engine 1 is shifted by the torque converter 2 and the automatic transmission 3, the output torque is transmitted to the drive wheels 5 via a power transmission mechanism such as a propeller shaft 4.

Air is supplied to the engine 1 through an intake passage 6. The intake passage 6 includes an air cleaner 7 for removing dust from the air and a throttle valve 8 for reducing the amount of air intake. Is provided. Throttle valve 8
Is provided with an electric actuator 9 composed of a step motor (or a DC motor). The actuator 9 basically operates according to a signal from the control unit 10 to depress an accelerator pedal 11, that is, an accelerator operation amount ( Hereinafter, this is called accelerator opening.)
, The throttle valve 8 is controlled. Here, as will be described later, the control unit 10 controls the throttle opening characteristic with respect to the accelerator opening and the like.
(Engine output characteristics) can be set almost freely. That is, the vehicle WD employs a so-called electric throttle system.

The control unit 10 is a comprehensive control means for the power train P using a microcomputer, and includes an accelerator opening α detected by an accelerator sensor 12 provided for an accelerator pedal 11, a driving wheel The driving wheel speed ω (peripheral speed) detected by the speed sensor 13, the engine speed ESP detected by the engine speed sensor 14, and output from a mode switch 15 for switching between a running mode (normal mode or sport mode). A predetermined control of the power train P is performed using the mode signal M and the like as control information. For example, according to a throttle opening characteristic set for each traveling mode, a throttle control for controlling the throttle valve 8 in accordance with an accelerator opening and the like, a shift control for the automatic transmission 3, and the like are performed. Here, the throttle control is performed by a method described below. The shift control of the automatic transmission 3 is performed by a well-known ordinary method through a plurality of solenoids 16 to 19, but since such shift control is not directly related to the gist of the present application, its explanation will be made. Is omitted.

Hereinafter, a control method of the throttle control by the control unit 10 will be described. (1) Basic logic of throttle control In this throttle control, a normal mode throttle opening characteristic and a sports mode throttle opening characteristic are basically set, and when the normal mode is selected, the normal mode throttle opening characteristic is set. , The throttle valve 8 is controlled according to the sports mode, and when the sports mode is selected, the throttle valve 8 is controlled according to the sports mode throttle opening degree characteristic.

In the normal mode throttle opening characteristic, when the accelerator opening is 0, the throttle opening becomes 0, and the accelerator opening is a predetermined reference value Y (for example, 30%, hereinafter referred to as the reference accelerator opening Y). The vehicle W
When the throttle opening is such that D is accelerated at a predetermined required acceleration and the accelerator opening is 100% (maximum), the maximum drive within a range in which no slip occurs on the drive wheels 5, that is, within the slip limit. The throttle opening is set such that a force (hereinafter, referred to as a maximum driving force within a slip limit) is obtained. In these intermediate regions, that is, in the region where the accelerator opening is 0 to Y and in the region where Y to 100%, the characteristics are such that the throttle opening linearly changes with respect to the accelerator opening. It should be noted that the change in the throttle opening in the intermediate region is not limited to a linear one. Here, the required acceleration and the maximum driving force within the slip limit decrease as the road surface μ decreases. Thus, in the normal mode, the throttle opening degree characteristic, for example when the road surface μ is large is as G ₃ in FIG. 4, so that the G ₄ are when the road surface μ is small.

Here, the required acceleration is the vehicle WD
At a predetermined time (for example, 20 ms) in a predetermined vehicle speed range
When the acceleration of the vehicle WD is detected (hereinafter referred to as acceleration data), and the frequency distribution (frequency distribution) of the acceleration data is obtained, the cumulative frequency (cumulative frequency) becomes a predetermined boundary value X. Acceleration. The required acceleration is
It takes different values depending on the vehicle speed as indicated by the curve G ₆ in FIG. That is, the required acceleration is a function of the vehicle speed. A curve G ₅ in FIG. 5, at the time of the normal mode running at a high μ road, the acceleration of 100% the accelerator opening, that is, the acceleration when driven by the maximum driving force within the slip limit. The boundary value X of the cumulative frequency is a predetermined value such that the acceleration data generated in a normal acceleration scene substantially matches the ratio of the acceleration data in the entire acceleration data, that is, a value that is a boundary between the normal acceleration and the rapid acceleration, Generally 80-9
It is set to a predetermined value within the range of 0%. Therefore, the acceleration generated in the normal acceleration scene or the required acceleration is basically equal to or less than the required acceleration. That is, in a normal acceleration scene, it is possible to cope with the acceleration equal to or less than the required acceleration. The reference accelerator opening Y is determined by the accelerator pedal 11
Is set to a substantially upper limit value (for example, accelerator opening 30%) of the partial area (common stepping area). Therefore,
A required acceleration, that is, an acceleration required in a normal acceleration scene, can be obtained by an accelerator operation in a partial region, and a good acceleration or running property adaptable to a traffic environment or the like can be obtained.

According to the normal mode throttle opening characteristics, even when the accelerator pedal 11 is depressed greatly, the driving wheels 5 do not slip, stable running performance is obtained, tire wear is suppressed, and fuel efficiency is improved. Can be In addition, the change in the engine output in response to the accelerator operation is not excessive, and the accelerator operability is improved. Therefore, it can be said that the normal mode is a traveling mode mainly suitable for normal traveling.

On the other hand, the throttle opening characteristic for the sports mode is such that when the accelerator opening is 0, the throttle opening becomes 0, and the accelerator opening is a predetermined intermediate value Z (for example, 50%) larger than the reference accelerator opening Y. In the following, this is referred to as an intermediate accelerator opening Z), the throttle opening is such that a maximum driving force within the slip limit can be obtained, and when the accelerator opening is 100% (maximum), the drive wheels 5 The throttle opening is set such that a maximum driving force in a region exceeding the slip limit (hereinafter, referred to as a maximum driving force outside the slip limit) is obtained. These intermediate regions, that is, regions where the accelerator opening is 0 to Z, and Z to 10
In the region of 0%, the characteristics are such that the throttle opening linearly changes with respect to the accelerator opening. Here, the maximum driving force within the slip limit and the maximum driving force outside the slip limit become smaller as the road surface μ becomes smaller. Therefore, in the sport mode, the throttle opening degree characteristic, for example when the road surface μ is large is as in G ₁ in FIG. 4, so that the G ₂ is when the road surface μ is small.

According to such a sports mode throttle opening characteristic, the maximum driving force within the slip limit is obtained at the intermediate accelerator opening Z, and in the region where the accelerator opening exceeds the intermediate accelerator opening Z, the driving wheels 5 are appropriately adjusted. A high driving force exceeding the maximum driving force within the slip limit can be obtained while slipping,
The vehicle WD can be accelerated strongly, and drift traveling can be performed. Therefore, it can be said that such a sport mode is a traveling mode suitable for sporty traveling that mainly requires high acceleration.

(2) Specific Throttle Control Hereinafter, a specific control method of the throttle control will be described with reference to flowcharts shown in FIGS. In this throttle control, while the vehicle WD is in a predetermined driving state, the road surface μ is measured (road surface μ estimation routine), while using the basic throttle opening map, the driving mode M, the accelerator opening α, and the gear position D (Gear position), the basic throttle opening Tb is calculated, and the basic throttle opening Tb is calculated based on the road surface μ.
(Hereinafter referred to as road surface friction correction) to calculate the target throttle opening TVO, and to output the target throttle opening TVO to the actuator 9 (target throttle opening calculation routine). . As described in the "basic logic of throttle control", the required acceleration, the maximum driving force within the slip limit, and the maximum driving force outside the slip limit, which are the basis of the throttle opening characteristics, change according to the road surface μ. Therefore, the target throttle opening TVO is a function of the accelerator opening α and the road surface μ for each shift speed in any traveling mode. However, in the calculation of the target throttle opening TVO, if both the accelerator opening α and the road surface μ are independent variables,
The operation method becomes complicated. Therefore, in the throttle control shown in FIGS. 2 and 3, in order to simplify the calculation, first, the required acceleration, the maximum driving force within the slip limit, and the maximum drive outside the slip limit on a standard high μ road (μ = 1.0). Based on power and
For each gear position, a basic throttle opening characteristic using only the accelerator opening α as an independent variable, that is, a basic throttle opening map is set, and road surface friction correction is performed on the basic throttle opening Tb obtained from the basic throttle opening map. Target throttle opening TV according to accelerator opening α and road surface μ
I try to get O.

When the control is started, first, in step # 1
Then, the accelerator opening α, the engine speed ESP, the actual throttle opening TVO ′, the gear position D of the automatic transmission 3, the driving wheel acceleration dω / dt, and the traveling mode M are read. Here, the drive wheel acceleration dω / dt refers to internal information in the control unit 10 obtained by differentiating the drive wheel speed ω (peripheral speed) detected by the drive wheel speed sensor 13. The internal information in the control unit 10 related to the shift control is also quoted for the gear position D.

Subsequently, the road surface μ is estimated in a road surface μ estimation routine in steps # 2 to # 7. In the present embodiment, the road surface μ is estimated from the driving force K when the driving wheel 5 is slipping during first-speed running. Generally, when the driving wheel 5 is slipping,
A certain functional relationship is established between the driving force K and the road surface μ.
(See FIG. 6). Therefore, at the time of slip, the road surface μ can be estimated from the driving force K. It is to be noted that the road surface μ is estimated only during the first-speed traveling because the output torque of the power train P increases during the first-speed traveling, so that the drive wheels 5 are likely to slip, and the road surface μ can be estimated. This is because there are more opportunities and the accuracy of the estimation increases.

More specifically, it is determined in step # 2 whether the gear position D is the first speed. Here, if it is determined that the gear position D is not the first speed (NO), as described above, the driving state is not suitable for estimating the road surface μ with high accuracy, and therefore, steps # 3 to # 7 are skipped. Then, a target throttle opening calculation routine of step # 8 and thereafter, which will be described later, is executed. On the other hand, if it is determined in step # 2 that the gear position D is the first speed (YES), step # 3
The engine speed ESP and the actual throttle opening TV
The driving force K is estimated based on O ′. That is, 1
During high-speed running, the driving force K and the engine speed ESP
For example, a functional relationship as shown in FIG. 6 is established between and the throttle opening TVO ′. Therefore, based on such a functional relationship, the engine speed ESP and the throttle opening TV
The driving force K is estimated from O ′.

Next, at step # 4, the drive wheel acceleration dω
It is determined whether / dt exceeds 2 g (twice the gravitational acceleration). In a normal automobile, the driving wheel acceleration in a state where no slip occurs is at most about 1 g. Therefore,
In the present embodiment, when the drive wheel acceleration exceeds 2 g with a margin, it is determined that the drive wheel 5 is slipping, and the road surface μ is estimated. Step #
If it is determined in step 4 that dω / dt> 2 g (YES), the road surface μ is set to 0.2 to 0.2 based on the driving force K in step # 7.
It is estimated in the range of 1.0. The relationship between the driving force K and the road surface μ in this case is, for example, as shown in FIG. In the example shown in FIG. 6, K = k ₁ at mu = 0.2, and the at K = k ₂ μ =
0.5, has a mu = 1.0 with K = k _3. Thereafter, the target throttle opening calculation routine of step # 8 and subsequent steps is executed.

On the other hand, if it is determined in step # 4 that dω / dt ≦ 2g (NO), it is determined in step # 5 whether or not the driving force K exceeds the threshold value K1. The threshold value K1 is a threshold value for detecting the return from the low μ road to the high μ road, and is set to a predetermined value that is a boundary between the low μ road and the high μ road. As described above, in the road surface μ estimation routine, the road surface μ is estimated (updated) every time the drive wheel 5 slips during the first-speed running. Therefore, a slip is likely to occur on a road surface having a relatively small road surface μ, so that there are many opportunities for estimating the road surface μ, and a change in the road surface μ can be quickly detected. However, on a road surface having a relatively large road surface μ, slippage is unlikely to occur, so that opportunities for estimating the road surface μ are reduced, and it is difficult to quickly detect a change in the road surface μ. For example, when the vehicle enters the high μ road from the low μ road, the detection of a change in the road surface μ corresponding to the road is delayed. Therefore, in the present embodiment, when the driving force K exceeds the threshold value K1 as shown in FIG. 6, it is determined that the road surface has returned to the high μ road, and the road surface μ is regarded as 1.0. I have to. If it is determined in step # 5 that K> K1 (YES),
It is determined that the road surface has returned to the high μ road, and step # 6
And the road surface μ is considered to be 1.0. Thereafter, a target throttle opening calculation routine of step # 8 and subsequent steps is executed. On the other hand, if it is determined that K ≦ K1 (NO), step #
Step 6 is skipped, and steps # 8 and below are executed.

The routine for calculating the target throttle opening in steps # 8 to # 15 will be described below. Step #
At 8, it is determined whether the traveling mode M is the normal mode (N) or not. If it is determined that the traveling mode M is the normal mode (YES), step # 9
Then, the basic throttle opening Tb is calculated based on the accelerator opening α and the gear position D using a normal mode basic throttle opening map as shown in FIG. In the normal mode basic throttle opening map shown in FIG.
The throttle opening characteristic is set as follows with respect to the accelerator opening α for each gear position D (gear position). a) When the accelerator opening α is 0, the basic throttle opening Tb becomes 0. b) When the reference accelerator opening Y is set to 30% and the accelerator opening α is 30%, the required acceleration in a standard running state on a high μ road where the road surface μ is 1.0 is obtained. Throttle opening. The required acceleration is set to, for example, an acceleration (90% required acceleration) such that the cumulative frequency in the frequency distribution of the acceleration data is 90%. c) When the accelerator opening α is 100%, the road surface μ is 1.0.
The throttle opening is such that the maximum driving force within the slip limit for the road surface can be obtained. d) A range where the accelerator opening α is 0 to 30%, and 30% to 1
In the region of 00%, the basic throttle opening Tb is
It changes linearly with the accelerator opening α. Note that the running characteristics of the vehicle WD when the normal mode throttle opening characteristics are used are as described in the basic logic of the throttle control.

Therefore, the basic throttle opening T obtained from the normal mode basic throttle opening map.
b is a target throttle opening corresponding to a road surface (high μ road) where the road surface μ is 1.0. Therefore, the following step # 10
In step # 12, the basic throttle opening Tb is subjected to road surface friction correction according to the road surface μ to obtain a target throttle opening TVO corresponding to the road surface μ. In this embodiment, the road surface friction is corrected by multiplying the basic throttle opening Tb by the road surface μ in principle.
In the calculation of the target throttle opening TVO, the road surface μ is not used as an independent variable, and the road surface friction is corrected in this way, as described above, in order to simplify the calculation method. In step # 10, the road surface μ is set to 0.
It is determined whether it is less than four. In this embodiment, on a low μ road where μ <0.4 in the normal mode, the road surface friction is corrected by multiplying Tb by μ in principle, while a relatively low road surface where μ ≧ 0.4 is satisfied. μ
The road surface friction correction is not performed on a road surface where the road surface is large. However, in the normal mode, since the engine output is suppressed in order to prevent the occurrence of slip, if the throttle opening is further reduced on a relatively large road surface μ such that μ ≧ 0.4, This is because a driving force corresponding to the road surface μ may not be obtained.

If it is determined in step # 10 that μ <0.4 (YES), in step # 11, the target throttle opening TVO is calculated by the following equation (1). That is, road surface friction correction is performed on the basic throttle opening Tb. TVO = Tb · μ ··················································· Equation 1 On the other hand, if it is determined in step # 10 that μ ≧ 0.4, (NO) In step # 12, the basic throttle opening Tb is directly set as the target throttle opening TVO. continue,
In step # 15, the target throttle opening TVO is output to the actuator 9, and the actuator 9 opens and closes the throttle valve 8 according to the target throttle opening TVO. Thereafter, the process returns to step # 1.

If it is determined in step # 8 that the driving mode M is not the normal mode (N), that is, it is determined that the driving mode M is the sports mode (NO), step # 13 is executed.
Then, the basic throttle opening Tb is calculated based on the accelerator opening α and the gear position D using a sports mode basic throttle opening map as shown in FIG. In the sports mode basic throttle opening map shown in FIG.
The throttle opening characteristic is set as follows with respect to the accelerator opening α for each gear position D (gear position). a) When the accelerator opening α is 0, the basic throttle opening Tb becomes 0. b) When the middle accelerator opening Z is set to 50% and the accelerator opening α is 50%, the maximum driving force within the slip limit for a high μ road where the road surface μ is 1.0 can be obtained. It becomes the throttle opening. c) When the accelerator opening α is 100%, the road surface μ is 1.0.
The throttle opening is such that the maximum driving force outside the slip limit for a high μ road is obtained. d) The range where the accelerator opening α is 0 to 50% and 50% to 1
In the region of 00%, the basic throttle opening Tb is
It changes linearly with the accelerator opening α. The running characteristics of the vehicle WD when the sports mode throttle opening characteristics are used are as described in the basic logic of the throttle control.

Subsequently, in step # 14, the target throttle opening TVO is calculated by the following equation (2). That is,
Road surface friction correction is performed on the basic throttle opening Tb. TVO = Tb · μ ···································································································································································· 2
Irrespective of the value of, the target throttle opening TVO may be calculated by the following equation (3). That is, the road surface μ is considered to be constant at 0.6. TVO = Tb · 0.6 ················································································ Equation 3 This is because if the road surface friction is corrected, the engine output becomes insufficient, and sufficient acceleration performance may not be obtained.

Subsequently, at step # 15, the target throttle opening TVO is output to the actuator 9, and the actuator 9 opens and closes the throttle valve 8 according to the target throttle opening TVO. Thereafter, the process returns to step # 1.

[0031]

According to the first aspect of the invention, when the normal mode is selected, the driving force applied to the driving wheels is suppressed to the maximum driving force within the slip limit (traction control), so that even when the accelerator pedal is depressed. The occurrence of slip is prevented, and running stability is improved. In addition, when the sport mode is selected, in a region where the accelerator operation amount exceeds the intermediate accelerator operation amount, a driving force exceeding the maximum driving force within the slip limit can be obtained while generating an appropriate slip on the driving wheel, so that when the accelerator pedal is depressed, Acceleration is enhanced, and drifting can be performed.

According to the second invention, basically the same operation and effect as those of the first invention can be obtained. Furthermore, while the basic engine output characteristics are set for the maximum road surface μ,
Since the engine output characteristics are corrected according to the road surface μ,
Driving force according to the road surface μ is obtained, and good running performance or acceleration performance according to the road surface condition is obtained. Further, the calculation of the engine output target value (target throttle opening) is simplified.

According to the third aspect, basically, the same operation and effect as those of the second aspect can be obtained. Furthermore, in the normal mode, a predetermined required acceleration can be obtained with the reference accelerator operation amount.For example, by setting the reference accelerator operation amount in the partial range, an acceleration suitable for the traffic environment can be obtained with the normal accelerator operation amount. Therefore, the maneuverability of the vehicle is improved.

According to the fourth aspect, when the normal mode is selected, the driving force applied to the driving wheels is suppressed to the maximum driving force within the slip limit, so that the occurrence of slip is prevented even when the accelerator pedal is depressed, and the vehicle is driven. Stability is increased. In addition, when the sport mode is selected, in a region where the accelerator operation amount exceeds the intermediate accelerator operation amount, a driving force exceeding the maximum driving force within the slip limit can be obtained while generating an appropriate slip on the driving wheel, so that when the accelerator pedal is depressed, Acceleration is enhanced, and drifting can be performed.

According to the fifth aspect, basically the same operation and effect as those of the fourth aspect can be obtained. Furthermore, while the basic engine output characteristics are set for the maximum road surface μ,
Since the engine output characteristics are corrected according to the road surface μ,
Driving force according to the road surface μ is obtained, and good running performance or acceleration performance according to the road surface condition is obtained. Further, the calculation of the engine output target value (target throttle opening) is simplified.

According to the sixth aspect, basically the same operation and effect as those of the fifth aspect can be obtained. Furthermore, in the normal mode, a predetermined required acceleration can be obtained with the reference accelerator operation amount.For example, by setting the reference accelerator operation amount in the partial range, an acceleration suitable for the traffic environment can be obtained with the normal accelerator operation amount. Therefore, the maneuverability of the vehicle is improved.

[Brief description of the drawings]

FIG. 1 is an explanatory side view of a power train around a vehicle equipped with an electric throttle system.

FIG. 2 is a first part of a flowchart showing a control method of throttle control.

FIG. 3 is a second half of a flowchart showing a control method of throttle control.

FIG. 4 is a diagram showing throttle opening characteristics when a normal mode is selected and when a sport mode is selected.

FIG. 5 is a diagram illustrating characteristics of a required acceleration and the like with respect to a vehicle speed.

FIG. 6 is a diagram showing a relationship between a driving force, an engine speed, and a throttle opening, and the like.

FIG. 7 is a diagram illustrating characteristics of a basic throttle opening with respect to an accelerator opening and a gear position when a normal mode is selected.

FIG. 8 is a diagram showing characteristics of a basic throttle opening with respect to an accelerator opening and a gear position when a sports mode is selected.

[Explanation of symbols]

 WD ... vehicle P ... power train 1 ... engine 3 ... automatic transmission 5 ... drive wheel 8 ... throttle valve 9 ... actuator 10 ... control unit 11 ... accelerator pedal 12 ... accelerator sensor 13 ... drive wheel speed sensor 14 ... engine speed sensor 15… Mode switch

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-60-147546 (JP, A) JP-A-4-203227 (JP, A) JP-A-3-112758 (JP, A) JP-A-1- 182535 (JP, A) JP-A-63-205432 (JP, A) JP-A-63-16141 (JP, A) JP-A-3-182650 (JP, A) JP-A-4-59437 (JP, A) JP-A-63-16142 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F02D 29/02 311 F02D 41/04 310 F02D 45/00 345

Claims (6)

(57) [Claims] An engine output characteristic changing system in which two types of engine output characteristics of a normal mode and a sports mode are set with respect to an accelerator operation amount, and a mode switching means for switching between the modes is provided. In the power train control device, when the accelerator operation amount is the maximum, the normal mode engine output characteristics are set so that the maximum driving force (the maximum driving force within the slip limit) in a state where the driving wheels do not slip is obtained. , The accelerator operation amount is a predetermined intermediate value
(Intermediate accelerator operation amount), the maximum driving force within the above-mentioned slip limit is obtained, and when the accelerator operation amount is the maximum, the maximum driving force in a state in which the driving wheels slip.
A power train control device for a vehicle, comprising: engine output characteristic setting means for setting the sports mode engine output characteristic so as to obtain (out-of-slip limit maximum driving force). 2. The vehicle power train control device according to claim 1, wherein the engine output characteristic setting means sets a maximum driving force within the slip limit and a maximum driving force outside the slip limit.
While setting to correspond to the maximum road surface friction on a practical road surface (maximum road surface μ), a road surface friction coefficient (road surface μ) is detected according to road surface μ detection means, and the road surface μ detected by the road surface μ detection means is set in accordance with the road surface μ. A power train control device for a vehicle, comprising: an engine output characteristic correcting means for correcting the maximum driving force within the slip limit and the maximum driving force outside the slip limit. 3. The power train control device for a vehicle according to claim 2, wherein the engine output characteristic setting means sets the accelerator operation amount to a predetermined reference value smaller than the intermediate accelerator operation amount.
A power train control device for a vehicle, wherein a normal mode engine output characteristic is set so that an acceleration (required acceleration) at which a cumulative frequency of acceleration data becomes a predetermined boundary value is obtained. 4. A power train control method for a vehicle in which two types of engine output characteristics of a normal mode and a sports mode are set for an accelerator operation amount so that the mode can be switched arbitrarily. At the maximum, the normal mode engine output characteristic is set so that the maximum driving force in the state where no slip occurs on the driving wheels (the maximum driving force within the slip limit) is obtained, while the accelerator operation amount is a predetermined intermediate value.
(Intermediate accelerator operation amount), the maximum driving force within the above-mentioned slip limit is obtained, and when the accelerator operation amount is the maximum, the maximum driving force in a state in which the driving wheels slip.
A power train control method for a vehicle, comprising: setting a sports mode engine output characteristic so as to obtain (a maximum driving force outside a slip limit). 5. The vehicle power train control method according to claim 4, wherein the maximum driving force within the slip limit and the maximum driving force outside the slip limit are set so as to correspond to the maximum road surface friction (the maximum road surface μ) on a practical road surface. Meanwhile, the road surface μ is detected and the road surface μ is detected.
A power train control method for a vehicle, wherein the maximum driving force within the slip limit and the maximum driving force outside the slip limit are corrected according to the following. 6. The vehicle power train control method according to claim 5, wherein when the accelerator operation amount is a predetermined reference value smaller than the intermediate accelerator operation amount, the cumulative frequency of the acceleration data is equal to a predetermined boundary value. A power train control method for a vehicle, wherein a normal mode engine output characteristic is set so as to obtain such an acceleration (required acceleration).