JPH0579371A - Driving force control device - Google Patents

Abstract

PURPOSE:To provide a driving force control device which makes it possible to obtain a sufficient responsiveness to the driving force control for automobile only with control of the throttle opening, thus contributing to the improvement of control accuracy, fuel consumption rate, and purification of the exhaust air. CONSTITUTION:The drive force control device comprises an acceleration decision means 1 for making a decision of an acceleration condition wherein the accelerator opening is rapidly increased, and a driving torque suppression control means 2 for making a control of the excessive driving torque which is produced at the time of, for example, a starting. At the time of the driving force suppression control, the throttle opening is set, before hand, at a value which is somewhat smaller than the value corresponding to the accelerator opening so as to improve the responsiveness of the throttle-opening control operation. Since the throttle opening is controlled through feed forward control operation so that the driving torque way become a target driving torque, a sufficient responsiveness is obtained not only to enable increasing the driving torque control accuracy for automobile but also to enable improving the fuel consumption rate and purifying the exhaust air.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to drive torque control of an automobile equipped with an electronic throttle valve control engine, and more particularly to a drive force control device suitable for suppressing excessive torque during acceleration.

[0002]

2. Description of the Related Art In a conventional control system of this type, for example, as disclosed in JP-A-2-305333,
The slip ratio obtained from the difference in rotation between the driven wheel and the driving wheel is fed back, and the throttle is adjusted to match the target slip ratio.
(Throttle valve) The opening was controlled. At this time, the throttle opening control start opening is larger than the opening corresponding to the accelerator pedal operation opening at that time.

Incidentally, as a device related to this kind of device, Japanese Patent Laid-Open Nos. 61-25937 and 61-1718 are available.
46, JP-A-62-20647, and JP-A-1-
The description of each publication of 208538 can be mentioned.

[0004]

In the above-mentioned prior art, the driving force (driving torque) control is started from a large throttle opening during acceleration, and the throttle opening is controlled by the feedback control based on the slip ratio. In other words, since the control is performed after the slip is detected, the response of the control is poor, and it is not possible to deal with the throttle control alone.Therefore, in addition to the throttle control, the brake control, the fuel ignition control No consideration was given to the need to ensure the responsiveness of the drive torque control by adding the above, and this adversely affected the maintenance of fuel consumption and the maintenance of the exhaust state.

The object of the present invention is to obtain sufficient responsiveness for controlling the driving force of an automobile only by controlling the throttle opening degree, and it is possible to improve control accuracy, improve fuel efficiency, and sufficiently contribute to exhaust gas purification. It is to provide a driving force control device.

[0006]

In order to achieve the above object, the present invention provides an acceleration determination means for determining an acceleration state in which the accelerator pedal operation opening is rapidly opened, and an excessive drive torque generated at the time of starting the vehicle. A drive torque suppression control means for suppressing the torque is provided, and the throttle opening is previously set to an opening smaller than the accelerator pedal operation opening during the drive torque suppression control.

[0007]

When the driver depresses the accelerator pedal and the accelerator pedal operation opening signal is input from the acceleration determining means and it is determined that the vehicle is in an accelerating state, the driving torque suppression control means uses the feedforward throttle opening. Control is executed.

That is, the drive torque suppression control means is composed of the maximum throttle opening degree calculation means and the control end determination means, and when it is judged that the vehicle is in an accelerated state, the maximum throttle opening degree calculation means changes the rate of increase of the accelerator pedal operation opening degree. On the other hand, in consideration of the air density and the like, the throttle opening that does not exceed the limit drive torque is calculated and output to the throttle controller. After that, the control end time is obtained from a signal such as the output shaft rotation speed or the drive torque taken in by the control end determination means, and the control end signal is output after the lapse of an arbitrary time, and the feedforward by the maximum throttle opening calculation means is performed. -Throttle opening control is terminated.

Therefore, the responsiveness of the throttle opening control is improved, and the control accuracy of the drive torque including the transient state is improved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The driving force control device according to the present invention will be described in detail below with reference to the embodiments shown in the drawings. FIG. 1 is a control block diagram of an embodiment of the present invention.
Is a drive torque suppression control means, 3 is a maximum throttle opening calculation means, 4 is a control end determination means, and 5 is a throttle controller.

When the driver depresses the accelerator pedal, the acceleration determining means 1 inputs an accelerator pedal operation opening signal. When the drive torque suppression control means 2 determines that the vehicle is in the accelerated state, the drive torque suppression control is executed. The drive torque suppression control means 2 is composed of a maximum throttle opening degree calculation means 3 and a control end determination means 4. As the accelerator pedal operation opening degree increases, the maximum throttle opening degree calculation means 3 causes the air density etc. In consideration of the above, the throttle opening that does not exceed the limit drive torque is calculated and output to the throttle controller 5. After that, the control end time is obtained from a signal such as the output shaft rotation speed or the drive torque taken into the control end determination means 4, the control end signal is output after an arbitrary time has elapsed, and the maximum throttle opening degree calculation means 3 outputs the control end signal. -The control of the throttle opening of the deforward is ended.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG. In this embodiment, the present invention is applied to an automobile equipped with an automatic transmission equipped with a torque converter. First, in the processing of step 6, from each sensor, the engine speed Ne, the torque converter turbine Rotational speed Nt, accelerator pedal operation opening α,
Then, the density ρ of the air taken in by the engine is read.

In the processing of step 7, it is judged whether or not the gear ratio of the transmission is the first speed at which a torque equal to or higher than the limit drive torque is generated. The process of step 8 is a process for judging whether or not the throttle control range is within the feed forward control. When the turbine rotation speed Nt is smaller than the target turbine rotation speed Ntst, the throttle control is performed. Run.

In the processing of step 9, the air density ρ and the throttle opening θ that does not exceed the limit drive torque in standard atmosphere
The maximum throttle opening k is calculated by the function f (ρ, θn) with n. In the process of step 10, the throttle opening k calculated in the process of step 9 is compared with the accelerator pedal operation opening α. If α> k, step 11
The speed ratio e is determined by the ratio between the turbine rotation speed Nt and the engine rotation speed Ne in the processing of.

In the processing of step 12, the target speed ratio eta
r is compared with the speed ratio e. If e ≧ etar is not satisfied, the maximum throttle opening degree k is input to the throttle opening degree θ in step 13, and this throttle opening degree θ is output. Therefore, the drive torque suppression control by the feedforward type throttle control is provided by the processing from step 6 to step 13.

On the other hand, when the result of the judgment processing of step 7, 8 or 10 is No, the processing of step 14 is executed and the throttle opening θ corresponding to the accelerator pedal operation opening α is output as it is. And therefore,
At this time, the drive torque suppression control by the feedforward method is not performed.

Next, in the processing of step 12, e ≧ etar
In this case, it is necessary to open the throttle opening θ from the current throttle opening k to the accelerator pedal operation opening α without shock. Therefore, at this time, step 1
In step 5, x = α−k is obtained, and then step 16
In this process, .theta. = (Nt / Ntst) .multidot.X + k is calculated, and control is performed until the turbine rotation speed Nt and the target turbine rotation speed Ntst match.

In the above control, it is necessary to obtain the turbine rotation speed Nt, but it is also possible to obtain this from the vehicle speed sensor signal at the output shaft of the transmission. The present invention can also be applied to an automobile without a bin sensor.

Next, the drive torque suppression control effect of this embodiment will be described with reference to FIG. In FIG.
(a) is a case of a conventional example of a vehicle with an automatic transmission equipped with a torque converter, and when the accelerator opening is rapidly opened, as shown in the figure, the driving torque sharply rises and greatly changes. The shaded portion in the figure is the excessive drive torque, and it is necessary to remove the excessive portion. Therefore, when throttle control is performed using the present invention, the maximum value of the drive torque becomes flat as shown in FIG. 7B, and excessive drive torque can be suppressed.

Therefore, according to this embodiment, the slip can always be surely suppressed regardless of the accelerator operation. In addition, in FIG. 3B, a, b,
c corresponds to the control given by the processes of steps 10, 13, 15, and 16 of FIG. 2, respectively.

Next, another embodiment of the present invention will be described with reference to FIG. FIG. 4 is a control flow chart for suppressing the drive torque in one embodiment in which the feedforward control by the torque feedback is adopted. First, in the processing of step 17, the drive torque Tn and the accelerator pedal are set. The operation opening α and the turbine rotation speed Nt are read.

In the process of step 18, it is determined whether or not the gear ratio of the transmission is the first speed at which a torque equal to or higher than the limit drive torque is generated. The process of step 19 is a process of determining whether or not the throttle control range is within the feed forward control. When the turbine rotation speed Nt is smaller than the target turbine rotation speed Ntst, the throttle control is performed. Run. In the process of step 20, the current drive torque Tn and the previous drive torque Tn-1 are compared to determine whether or not the vehicle is in an accelerating state. If it is in the acceleration state, the process proceeds to step 21, and the timer Timer
Is incremented. Next, in the processing of step 22, the change rate dT / dt = (Tn-Tn-1) / Δt of the driving torque during acceleration is calculated. Then, in the processing of step 23, the time TIME until the limit drive torque is reached is calculated by the function j of the current drive torque Tn and the time change dT / dt of the drive torque. Further, in the processing of step 24, the throttle opening control which considers the delay of the air flow rate corresponding to the intake pipe filling by the limit drive torque Tmax, the current drive torque Tn, and the function f of the temporal change dT / dt of the drive torque. Start time time
Is calculated.

In the processing of step 25, the timer Timer and TIME-time are compared. Then, Timer ≧ TIME-time
If so, the control of closing the throttle opening ([theta] = [alpha] -a) is executed in the next step 26. Here, a is a positive constant. Finally, in step 27, the current drive torque Tn is input to the previous drive torque Tn-1 to return.

On the other hand, if the judgment result is No in any of steps 18, 19, 20 and 25, the process proceeds to step 28 and the timer is cleared (Timer =
0) is executed, and in the process of step 29, the throttle opening θ (θ = α) corresponding to the accelerator pedal operation opening α is output. ..

FIG. 5 shows operating characteristics according to the embodiment of FIG.
Throttle according to changes in accelerator pedal operation opening α
(Throttle) The opening θ increases, and then the drive torque starts to increase. Then, if the drive torque begins to rise, TIM
E and time are calculated and the throttle opening is controlled to close after the time of TIME-time so that the driving torque becomes equal to or less than the limit driving torque Tmax. And before the control ends,
Match the accelerator pedal opening and throttle opening,
The control ends. Therefore, according to this embodiment as well, excessive torque generation can be sufficiently suppressed, and the risk of slip can be reliably eliminated.

Next, FIG. 6 is a control block diagram for suppressing excessive drive torque according to the present invention when the reference model is used. The accelerator pedal operation opening α (target value) is set to the torque converter model 30 and the reverse intake pipe. It is input to a reference model 32 including a model 31 and further to a feedback controller 33. The output of the reference model 32 is the controlled object 3
4 and drive torque is generated. Therefore, this driving torque is fed back, and the deviation from the target value is output from the feedback controller 33. At the same time, the reference model 32 is identified so that the output of the feedback controller 33 becomes zero.

FIG. 7 is a control flow chart of the embodiment of FIG.
In the process of step 35, the accelerator pedal operation opening α, the engine speed Ne, the turbine speed Nt and the drive torque T are read. Next, in the processing of step 36, the maximum value αmax of the accelerator pedal operation opening α that is the target drive torque and the limit drive torque Tmax are made to coincide with each other, and a limiter function is provided.

In the processing of step 37, the torque converter is
The torque ratio Th of the torque is calculated from the engine speed Ne and the function g of the turbine speed Nt. In the process of step 38, the correction target drive torque r = α / Th is calculated. In the process of step 39, the throttle passing air flow rate Ga = V
・ Calculates dr / dt + r ・ Q. However, V is the intake pipe volume,
Q is the air flow rate into the cylinder. In the process of step 40, the throttle opening area A is calculated by the following equation.

A = Ga / (cψ√Paρa) where c is the flow coefficient, ψ is a coefficient that changes with the pressure in the intake pipe, Pa is atmospheric pressure, and ρa is the air density at atmospheric pressure.

[0030] In the process of step 41, it calculates the uncorrected throttle opening ^{θ1 = cos ~ 1 (x)} -tan ~ 1 (y). However,
x = 1−A / (π · R ² ), y = tanl−π · t / (2 · R ·
cosl), and R is the throttle valve radius, l
(L) is the throttle valve mounting angle, and t is the valve plate thickness of the throttle valve.

In the processing of step 42, the throttle opening .theta. = K.multidot.d.theta.1 / dt + .theta.1.m is calculated by correcting the delay of the motor (actuator) for driving the throttle. However,
m and k are constants. The above-described arithmetic processing from steps 36 to 42 is the above-mentioned reference model control.

Next, in step 43, it is determined whether or not the drive torque T and the accelerator pedal operation opening α are equal. If they are equal, it is returned. Then,
If they are not equal, the processing of step 44 is executed, and T
It is determined whether or not> α. Then, in steps 45 and 46, if T> α, θ = θ−b is set, and if T <α, θ = θ + a is set, and the subsequent step 47 is performed. Outputs the throttle opening θ. However, a and b are model correction constants.

Next, FIG. 8 shows a control flow chart for suppressing the drive torque at the time of starting in one embodiment of the present invention in the racing select state (a kind of transmission timing mode of the transmission).
In the chart, the gear ratio signal N
D, hydraulic signal Pre, accelerator pedal operation opening α, engine speed Ne, and vehicle speed Vsp are read. In the process of step 49, the neutral state ND = 0 and the state where the engine speed Ne is higher than the target engine speed Ne0 Ne ≧ Ne
It is determined whether the AND condition of 0 is satisfied.

In the process of step 50, it is determined whether or not the gear ratio has reached the first speed, and in the process of step 51, it is determined whether the vehicle speed Vsp is smaller than the target vehicle speed Vs0.
Then, if all the processes from steps 49 to 51 are Yes, it is determined that the driving torque is in the excessive drive torque region.

Therefore, when it is determined that the torque is in the excessive drive torque region, first, the throttle opening θ is fully closed in the process of step 52. Then, in the process of step 53, the clutch hydraulic pressure signal Pre of the transmission is changed to the target hydraulic pressure signal P.
It is judged whether or not it has become larger than r0. The target hydraulic pressure signal Pr0 is a hydraulic pressure at which torque starts to be transmitted. If Pre ≧ Pr0 is not satisfied, the loop is executed.

In the process of step 54, it is determined whether the engine speed Ne is higher than the set engine speed Ne1. It should be noted that the set engine speed Ne1 is set so that when the engine speed Ne is lower than that, torque due to inertia of the rotating portion is not applied and excessive drive torque is not generated.
When Ne ≧ Ne1, fuel cut control is performed in the process of step 55, and the loop is performed until Ne <Ne1.

On the other hand, if Ne <Ne1, step 56.
In the process of, the throttle opening θ is incremented by θ0 so that it becomes the accelerator pedal operation opening α,
In the process of step 57, the loop is executed until θ ≧ α.

However, if No in steps 49, 50 and 51, the throttle opening θ (θ = α) corresponding to the accelerator pedal operation opening α is output in step 58.

FIG. 9 shows the operating characteristics of the embodiment of FIG. 8. When the engine speed is Ne0 and the shift signal is shifted from the neutral state to the first speed, the throttle opening is shown by a broken line. So that it is fully closed. Then, when the clutch operating oil pressure becomes Pr0 and the engine speed does not reach Ne1, the fuel cut control is executed. After that, when the engine speed reaches Ne1, the fuel cut control is ended, and the throttle valve opening is gradually set to the accelerator pedal operation opening.

Therefore, according to this embodiment as well, excessive torque is not generated and slip can be reliably suppressed.

Next, FIG. 10 is a control flowchart of an embodiment in which the present invention is applied to traction control (TCS). First, in the process of step 59, it is determined whether or not traction control is performed, and then the slip ratio s is read in the process of step 60. Further, step 61
The accelerator pedal operation opening α is read by the processing of. In the processing of step 62, it is determined whether or not the accelerator pedal operation opening α is larger than the previous accelerator pedal operation opening αn−1. If larger, α−n is set to the throttle opening θ in the processing of the next step 63. If it is not larger, α-n1 is substituted in the process of step 64.

Here, when the process of step 63 is executed, the throttle opening control by slip ratio feedback is executed in the processes of steps 65 to 69. Then, the throttle opening θ is output in the process of step 70, and αn-1 = α is executed in the process of step 71 to return.

Next, FIG. 11 is a control flow chart of one embodiment in which the present invention is applied to supercharging pressure control of a turbocharger or the like. First, in the processing of steps 72 and 73, The supercharging pressure Pm and the accelerator pedal operating opening α are read respectively. In the process of step 74, it is determined whether or not the supercharging pressure Pm has become larger than the target supercharging pressure P1. If Pm ≧ P1 is not satisfied, the throttle opening θ (θ = θ) corresponding to the accelerator pedal operation opening α is obtained in the processing of step 75.
Output α). On the other hand, if Pm ≧ P1, then α-z is substituted for the throttle opening θ in the process of step 76 to secure the responsiveness of throttle control.

In the following step 77, the boost pressure Pm
Is smaller than the limit supercharging pressure P2.
In step 80, the throttle opening θ is output. If it is larger, the processing in step 79 is executed.
The waist gate valve opening control of the bocharger is executed.

[0045]

According to the present invention, since the throttle opening is controlled by the feedforward control so that the target driving torque is obtained, sufficient responsiveness can be obtained and the driving torque of the automobile can be controlled. It is possible to improve accuracy. Further, since the drive torque suppression control can be performed only by the throttle control, the fuel consumption can be improved and the exhaust gas can be greatly purified.

[Brief description of drawings]

FIG. 1 is a control block diagram showing an embodiment of a driving force control device according to the present invention.

FIG. 2 is a control flow chart of an embodiment of the present invention.

FIG. 3 is a characteristic diagram for explaining the operation of the embodiment of the present invention.

[Fig. 4] Feed forward by torque feedback
3 is a control flow chart of an embodiment of the present invention in which the mode control is used.

5 is a characteristic diagram for explaining the operation of the embodiment of FIG.

FIG. 6 is a control block diagram showing an embodiment of the present invention when a reference model is used.

7 is a control flow chart showing the operation of the embodiment of FIG.

FIG. 8 is a control flow chart for explaining the operation of an embodiment when the present invention is applied at the time of starting a racing select.

9 is a characteristic diagram for explaining the operation of the embodiment of FIG.

FIG. 10 is a control flowchart of an embodiment in which the present invention is applied to traction control.

FIG. 11 is a control flowchart of an embodiment in which the present invention is applied to supercharging pressure control of a turbo charger or the like.

[Explanation of symbols]

 1 acceleration determination means 2 drive torque suppression control means 3 maximum throttle opening calculation means 4 control end determination means 5 throttle controller

Claims (4)

[Claims] 1. A vehicle including an electronically controlled throttle valve type engine, which comprises acceleration determining means for determining an acceleration state from an operation opening of an accelerator pedal, maximum throttle opening calculating means, and control end determining means. A drive which is characterized in that a torque suppression control means is provided and the throttle opening is controlled to a smaller opening than the accelerator pedal operation opening during drive torque suppression control determined from the acceleration state. Force control device. 2. The drive force control device according to claim 1, wherein the drive torque suppression control means is provided with a speed ratio feedback means. 3. The drive force control according to claim 1, wherein the drive torque suppression control means is provided with a torque feedback means for calculating a drive torque value and a temporal change of the drive torque value. apparatus. 4. The driving force control device according to claim 2, wherein a vehicle speed sensor signal is used as a turbine rotation speed detection value of the torque converter in the speed ratio feedback means.