JP2979544B2 - Engine output control device - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial application field) The present invention relates to an engine output control device that controls an engine output by, for example, a throttle valve.

(Prior Art) In general, an engine output control device called a drive-by-wire has been developed and is being put to practical use.

This is because the accelerator pedal and the throttle valve are not mechanically connected, the depression position (operation amount) of the accelerator pedal is detected, the target drive shaft torque is determined from the detected position, and the target drive shaft torque is obtained. Then, the throttle valve is driven by a motor.

As an application example of the drive-by-wire, there is a control for adjusting the relationship between the accelerator operation and the engine output to a predetermined condition in consideration of the driver's feeling and the movement of the vehicle, so-called throttle-by-wire control.

In addition, there is traction control that narrows the opening of the throttle valve regardless of the depression of the accelerator pedal and converges the slip when a slip occurs on the wheel.

Further, there is an auto cruise control that maintains an arbitrary speed even when the accelerator pedal is released.

On the other hand, all three types of control are drive-by-
It would be advantageous if it could be integrated as a wire system device.

(Problems to be Solved by the Invention) However, in performing such integration, there is a problem that the device configuration becomes large simply by arranging the configuration of each control.

In addition, since the final operation means of each control is a throttle valve, and the number of the throttle valve is only one, there is a problem in that the opening degree control for the throttle valve is complicated in integration.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide an accelerator-by-wire control and a traction control without increasing the size of a device and without complicating the control. , And an engine output control device capable of integrally incorporating auto cruise control.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention relates to a vehicle that transmits an engine output to a drive shaft based on an engine output control amount, according to an accelerator operation amount. First setting means for determining a _first target drive shaft torque Twt _1; and a second target drive shaft torque required to converge wheel slip.
A second setting means for determining a Twt _2, a third setting means for determining a third target drive shaft torque Twt ₃ required to perform constant speed running, these first target drive shaft torque Twt _1, the second Selection means for selecting one of the target drive shaft torque Twt ₂ and the third target drive shaft torque Twt ₃ in accordance with the driving state of the vehicle, and obtaining the target drive shaft torque selected by the selection means. A target engine control amount setting means for obtaining a required target engine output control amount, and a control means for adjusting the engine output control amount in accordance with the target engine output control amount obtained by the target engine control amount setting means.

(Operation) The target drive shaft torque Twt _{1 of} the throttle-by-wire control,
Target drive shaft torque Twt ₂ of the traction control, and the target drive shaft torque Twt ₃ of the auto-cruise control is generated each one of these target drive shaft torque is selected according to the operation mode. Then, a target engine output control amount is obtained from the selected target drive shaft torque, and the engine output control amount is adjusted according to the target engine output control amount. The configuration from obtaining the target engine output control amount to adjusting the engine output control amount is also used for throttle-by-wire control, traction control, and auto cruise control.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes an air cleaner;
And an air flow sensor 3. This air flow sensor 3 detects the amount of intake air sucked through the element 2.

An intake path 5 for introducing combustion air from the air cleaner 1 to the engine main body 4 is provided, and a throttle valve 6 is provided in a middle part of the intake path 5.

The throttle valve 6 adjusts the amount of air passing through the intake passage 5 (corresponding to the engine output control amount), and can smoothly rotate from the fully closed position to the fully opened position. The rotation shaft of the throttle valve 6 is connected to the shaft of a step motor 7.

Further, the torque converter 11 is connected to the output shaft of the engine body 4.
And a shaft 12 is connected to the turbine of the torque converter 11. In addition, shaft 12
Is connected to a drive shaft 14 via a transmission 13,
Wheels 15 are mounted on the drive shaft 14.

Note that an automatic transmission is constituted by the torque converter 11, the shaft 12, and the transmission 13.

The intake air amount A detected by the air flow sensor 3 is sent to an engine control computer (hereinafter, referred to as ECI) 16, where the intake air amount A / Nr per revolution.
Is calculated for each predetermined crank angle, and the intake air amount A / Nr
Is injected into the cylinder of the engine body 4 in an amount determined according to the amount of fuel.

Further, the intake air amount A / Nr calculated by the ECI 16 is supplied to a main control unit 70 described later.

In addition, as for the unit of the intake air amount, the air amount A / N per rotation is used in the following description.

On the other hand, reference numeral 20 denotes an access pedal, which is connected to a throttle-by-wire (TBW) control unit 30, which is a first setting means.

The throttle-by-wire control unit 30 detects a depression position Ap as an operation amount of the accelerator pedal 20, and determines a _first target drive shaft torque Twt1 corresponding to the detection position Ap.

Reference numeral 40 denotes a traction control unit serving as a second setting unit, which detects wheel slip from the driven wheel speed Vf and the drive wheel speed Vr detected by a sensor (not shown), and the slip can converge (convergence). The second target drive shaft torque Twt ₂ is supplied.

Reference numeral 50 denotes an auto cruise control unit which is a third setting means, which is necessary for maintaining a constant vehicle speed when the auto cruise mode (ASC mode) is set by operating the auto cruise switch 60. That is, a third target drive shaft torque Twt ₃ required for constant speed traveling is obtained.

The target drive shaft torques Twt ₁ , Twt ₂ , Twt ₃ determined or obtained by these control units are supplied to the main control unit 70.

The main control unit 70 controls the target drive shaft torque Twt ₁ , Twt ₂ , Twt ₃
At least one of the driving modes (driving state of the vehicle)
Selection function means for selecting a target engine output amount required by the means, a target engine control amount setting function means for obtaining a target intake air amount as a target engine output control amount necessary for obtaining a target drive shaft torque selected by this means, and a target determined by this means. Intake air volume and
A function is provided for obtaining a target throttle opening θ for the throttle valve 6 according to the intake air amount A / Nr from the ECI 16.

The driving mode is an auto cruise switch
Auto cruise mode set by 60 operations,
Slip amount DV required by traction control unit 40
There is a traction mode (TRC mode) that is set when is greater than or equal to a certain value.

The target throttle opening θ obtained by the main controller 70 is supplied to the motor drive controller 90.

The motor drive control unit 90 supplies the number of drive pulses corresponding to the target throttle opening θ to the stepping motor 7, and sets the opening of the throttle valve 6 to the target throttle opening θ.

Throttle-by-wire control unit 30 to motor drive control unit
FIG. 2 shows a specific configuration up to 90.

First, the throttle-by-wire 30 includes an accelerator pedal position sensor 31 and a target drive shaft torque determining unit 32.

The accelerator pedal position sensor 31 detects the depression position Ap of the accelerator pedal 20, and outputs a signal of a voltage level corresponding to the depression position Ap using, for example, a potentiometer.

The target drive shaft torque determining unit 32 calculates the accelerator pedal position Ap.
And the vehicle speed V (follower wheel speed Vf) as a parameter to determine the target drive shaft torque Twt _1. For example, in the low-speed range, the vehicle corresponds to the accelerator pedal position Ap regardless of the vehicle speed V in consideration of the feeling of acceleration at the start. The vehicle speed V is determined in consideration of speed stability (speed maintenance) when the vehicle speed V is higher than a predetermined value.
The value which decreases with the increase of is determined. FIG. 3 shows the determination conditions.

The traction control unit 40 includes a differentiator 41 for obtaining the vehicle acceleration from the driven wheel speed Vf, a reference drive shaft that can be transmitted to the road surface from the vehicle acceleration obtained by the differentiator 41 and the vehicle weight W and the wheel diameter R stored in advance. A reference drive shaft torque calculation unit 42 for calculating the torque Two, a calculation unit 43 for subtracting the driven wheel speed Vf from the drive wheel speed Vr to obtain a slip amount DV (= Vr−Vf), and a slip amount obtained by the subtraction unit 43 A PID controller 44 that calculates a feedback operation amount ΔT (torque amount) from DV, and the PID controller 44
An adder 45 adds the operation amount ΔT obtained by the controller 44 to the reference drive shaft torque Two as a correction amount, and calculates the target drive shaft torque Twt ₂ based on the reference drive shaft torque Two and by feedback of the slip amount DV. I am asking for it.

The auto cruise control unit 50 calculates an actual drive shaft torque Twm transmitted to the drive shaft 14, an actual drive shaft torque calculation unit 51, and sets the driven wheel speed Vf when the auto cruise mode is set by the auto cruise switch 60 to the target vehicle speed Vt. A subtraction unit 53 for subtracting the driven wheel speed Vf from the target vehicle speed Vt determined by the target vehicle speed determination unit 51 to determine a speed deviation ΔV, and a speed deviation ΔV obtained by the subtraction unit 53 From the feedback operation amount ΔT (torque amount)
The PID controller 54 includes an adder 55 that adds the operation amount ΔT obtained by the PID controller 54 to the actual drive shaft torque Twm as a correction amount, and based on the actual drive shaft torque Twm, and based on the speed deviation Δ
Based on the feedback of V, the target drive shaft torque Twt ₃ is obtained.

Here, the actual drive shaft torque calculation unit 51 uses the engine speed Ne detected by an engine speed sensor (not shown) and the torque capacity coefficient C and torque ratio τ of the torque converter 11 stored in advance, From the formula, the actual drive shaft torque Tw
m is calculated.

Twm = τ (e) C (e) Ne ² where e is the rotational speed ratio between the output shaft of the engine body 4 and the turbine of the torque converter 11, and the rotational speed ratio e is used as a parameter for the torque capacity coefficient C and the torque. The ratio τ is determined. This relationship is shown in FIG.

It should be noted that the actual drive shaft torque Twm can also be obtained by measurement using a torque meter without using calculation.

The main control unit 70 selectively outputs one of the target drive shaft torques Twt ₁ , Twt ₂ , Twt ₃ supplied from the control units 30, 40, 50 in response to a command from a selection control unit 76 described later. The shaft torque selecting unit 71, the target drive shaft torque Tw selected by the selecting unit 71
a target engine output torque calculation unit 72 for calculating a target engine output torque Te from t; a target air amount calculation unit 73 for obtaining a target intake air amount A / Nt from the target engine output torque Te obtained by the calculation unit 72; Target intake air volume determined by
A target opening calculator 74 for calculating a target throttle opening θ from A / Nt, the engine speed Ne, and the intake air amount A / Nr, and compares the values of the target drive shaft torques Twt ₁ , Twt ₂ , Twt ₃ with each other. The target drive shaft torque comparing unit 75 controls the selecting operation of the selecting unit 71 according to the comparison result of the comparing unit 75, the operation of the auto cruise 60, and the operation mode based on the value of the slip amount DV of the traction control unit 40. And a selection control unit 76.

Here, the target engine output torque calculation unit 72 calculates the target drive shaft torque Twt necessary for obtaining the target drive shaft torque Twt in consideration of the gear ratio ρ of the transmission 13 and the torque ratio τ of the torque converter 11 as in the following equation. Engine output torque Te
Is calculated.

Te = Twt / (ρτ) The target air amount calculation unit 73 maps the relationship shown in FIG. 5 between the intake air amount A / N and the engine output Te (correspondence table).
The target intake air amount A / Nt corresponding to the target engine output torque Te is obtained based on the map. It is of course possible to store the relationship in FIG. 5 as a mathematical expression and calculate the target intake air amount A / Nt using the mathematical expression.

The target opening degree calculating section 74 uses the engine speed Ne as a parameter, and based on the relationship between the intake air amount A / N and the throttle opening degree θ as shown in FIG. The target throttle opening θ corresponding to the amount A / Nt is calculated.

In addition, the target opening calculation unit 74 is configured to feed back the intake air amount A / Nr as a correction amount in calculating the opening in order to correct a deviation of the intake air amount due to an error in the throttle valve position. .

 FIG. 7 shows a specific example of the target opening calculating section 74.

As shown in FIG. 7, the target intake air amount A / Nt is supplied to a target throttle opening calculation unit 701 and a subtraction unit 702.

The target throttle opening calculation unit 701 calculates the target intake air amount A / N
The target throttle opening θt is calculated from t and the engine speed Ne.

The subtraction unit 702 calculates the target intake air amount A / Nt and the intake air amount A / Nr.
Is calculated, and the difference becomes a feedback operation amount Δθ (opening amount) in the PI controller 703.
Then, the operation amount Δθ is added to the target throttle opening θt by the adding unit 704, so that a final target throttle opening θ is obtained.

Next, the operation of the above configuration will be described with reference to FIG.

When the accelerator pedal 20 is depressed, the depression position Ap is detected by the accelerator pedal position sensor 31.

At this time, if the vehicle speed V is in a low speed range, the accelerator pedal position Ap is determined regardless of the vehicle speed V in consideration of the feeling of acceleration at the time of starting.
Equal the corresponding target drive shaft torque Twt ₁ is determined by the target drive shaft torque determining unit 32. If the vehicle speed V is more than the predetermined amount, taking into account the speed of the stability (speed maintenance), the target drive shaft torque Twt ₁ decreases with an increase in the vehicle speed V is determined by the target drive shaft torque determining unit 32.

Determined target drive shaft torque Twt ₁ is supplied to the main control unit 70.

Moreover, the traction control unit 40 obtains the slip amount DV subtracts the driven wheel speed Vf from the driving wheel speed Vr, obtaining the target drive shaft torque Twt ₂ which the slip may converge.

That is, the vehicle body acceleration is obtained from the driven wheel speed Vf, and the reference drive shaft torque Two that can be transmitted to the road is calculated from the vehicle body acceleration and the vehicle weight W and the wheel diameter R stored in advance.
At the same time, the slip amount DV (= Vr−Vf) is obtained by subtracting the driven wheel speed Vf from the drive wheel speed Vr, and the feedback operation amount ΔT (torque amount) is obtained from the slip amount DV. Then, the obtained operation amount ΔT is added as a correction amount to the reference drive shaft torque Two to obtain a target drive shaft torque Twt ₂ .

The target drive shaft torque Twt ₂ is supplied to the main controller 70.

The auto cruise control unit 50 always calculates the actual drive shaft torque Twm transmitted to the drive shaft 14 based on the engine speed Ne, the torque capacity coefficient C of the torque converter 11, and the torque ratio τ. At the same time, the state of the auto cruise switch 60 is monitored. When the auto cruise switch 60 is operated to set the auto cruise mode, the driven wheel speed Vf at that time is determined as the target vehicle speed Vt. Further, the driven wheel speed Vf is subtracted from the determined target vehicle speed V, and the speed deviation ΔV
Is obtained, and the operation amount ΔT of feedback is obtained from the speed deviation ΔV. Then, the obtained operation amount ΔT is added to the actual drive shaft torque Twm as a correction amount, and the target drive shaft torque Twt ₃
Ask for.

The target drive shaft torque Twt ₃ is supplied to the main controller 70.

The auto cruise control unit 50 detects when the auto cruise switch 60 is operated again to release the auto cruise mode or when the brake pedal or the accelerator pedal 20 of the vehicle is depressed, and detects the target vehicle speed Vt. Cancel the decision.

On the other hand, the main control unit 70 compares the value of the target drive shaft torque Twt _1, Twt _2, Twt ₃ from the control unit 30, 40, 50 to each other. Also,
The traction mode (TRC mode) is set when the slip amount DV of the traction control unit 40 is equal to or more than a certain value, and the traction mode is not set when the slip amount DV is equal to or less than the certain value. Further, it is determined whether or not the auto cruise mode (ASC mode) is set by the auto cruise switch 60.

Thus, the main control unit 70, instead of the traction mode, moreover condition without auto cruise mode if satisfied, the target drive shaft torque Twt ₁ throttle-by-wire control unit 30 is selected.

When the target drive shaft torque Twt ₁ is selected, the target engine output torque required to obtain the target drive shaft torque Twt ₁
Te is calculated in consideration of the gear ratio ρ of the transmission 13 and the torque ratio τ of the torque converter 11. Then, the target intake air amount A / Nt required to obtain the target engine output torque Te is obtained, and the target throttle opening θ required to obtain the target intake air amount A / Nt is determined by the engine speed Ne.
And the intake air amount A / Nr.

Is calculated, the step motor 7 is driven in accordance with the calculation result, and the throttle valve 6
Is set to the target throttle opening θ.

In this way, the target drive shaft torque Twt ₁ according to the depression position Ap of the accelerator pedal 20 is actually exerted and transmitted to the drive shaft 14 to be driven by the wheels 15.

If the main control unit 70 satisfies the condition that the vehicle is not in the traction mode but is in the auto cruise mode, the target drive shaft torque Tw of the auto cruise control unit 50
t ₃ is selected.

When the target drive shaft torque Twt ₃ is selected, the target engine output torque required to obtain the target drive shaft torque Twt ₃
Te is calculated, and the target intake air amount A / Nt and the target throttle opening θ are sequentially calculated in the same manner as described above. Then, the throttle valve 6 is set to the target opening degree θ.

In this manner, the target drive shaft torque Twt ₃ is actually exerted and transmitted to the drive shaft 14, and the vehicle travels at a constant speed at the target vehicle speed Vt.

However, when the auto cruise mode is released by re-operating the auto cruise switch 60 or the brake pedal or the accelerator pedal 20 corresponding to the auto cruise mode release command is depressed in this constant speed traveling, the target The selection of the drive shaft torque Twt ₃ is released, and the constant speed traveling ends.

Further, in the main control unit 70, the traction mode is set, and if the condition that the value of the target drive shaft torque Twt ₂ of the traction control unit 40 is not the maximum is satisfied, that is, the value of the target drive shaft torque Twt ₂ Is smaller than _one of the other target drive shaft torques Twt ₁ and Twt ₃ , the target drive shaft torque Twt ₂ is selected.

That is, the phenomenon that the value of the target drive shaft torque Twt ₂ becomes small is due to the occurrence of slip, and the target drive shaft torque Twt ₂ is selected to ensure safety.

When the target drive shaft torque Twt ₂ is selected, the target engine output torque required to obtain the target drive shaft torque Twt ₂
Te is calculated, and the target intake air amount A / Nt and the target throttle opening θ are sequentially calculated in the same manner as described above. Then, the throttle valve 6 is set to the target opening degree θ.

Thus, the target drive shaft torque Twt ₂ is actually exerted and transmitted to the drive shaft 14, whereby the slip is converged.

However, even in the traction mode, if the value of the target drive shaft torque Twt ₂ is the maximum, that is, if no slip occurs, the target drive shaft torque Twt ₁ or the target drive shaft The selection of the torque Twt ₃ is made.

In this way, by unifying the throttle-by-wire control, the traction control, and the auto-cruise control with the target drive shaft torque Twt, which is a common element of each other, the configuration up to obtaining the throttle opening θ from the target drive shaft torque Twt is obtained. Each control can be shared.

Therefore, all of the throttle-by-wire control, traction control, and auto-cruise control can be integrated as a drive-by-wire system device without increasing the size of the device.

Moreover, since the target driving shaft torque Twt ₁ of each control, the Twt _2, Twt ₃ is configured to select according to the size and mode of operation of each other value, causing a complication of the opening control for the throttle valve 6 Therefore, the functions of each control can be fully utilized. That is, it is possible to ensure an improvement in safety by traction control.

In the above-described embodiment, the throttle valve 6 is driven by the step motor. However, the throttle valve 6 may be driven by a DC motor instead of the step motor. The DC motor is driven so that the detected opening matches the target throttle opening θ. Further, it is not limited to the motor, and may be hydraulically driven or pneumatically driven.

Also, the gasoline engine in which both engine output control amounts are intake air amounts has been described as an example, but the present invention is similarly applicable to a diesel engine in which the engine output control amount is a fuel injection amount.

In addition, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention.

[Effects of the Invention] As described above, according to the present invention, in a vehicle that transmits an engine output based on an engine output control amount to a drive shaft, a first target drive shaft torque Twt ₁ is set according to an accelerator operation amount. First setting means for determining, and a second target drive shaft torque Twt ₂ required to converge wheel slip.
And a third setting means for obtaining a _third target drive shaft torque Twt ₃ required for performing constant speed traveling, and a first target drive shaft torque Twt ₁ , a second target Selecting means for selecting one of the drive shaft torque Twt ₂ and the third target drive shaft torque Twt ₃ in accordance with the driving state of the vehicle, and a driving means necessary for obtaining the target drive shaft torque selected by the selecting means. The apparatus includes target engine control amount setting means for obtaining a target engine output control amount, and control means for adjusting the engine output control amount in accordance with the target engine output control amount obtained by the target engine control amount setting means. An engine output control device that enables integrated integration of accelerator-by-wire control, traction control, and auto-cruise control without increasing the size of the vehicle and without complicating the control. Can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of the present invention and a configuration of a vehicle related thereto, FIG. 2 is a diagram specifically showing a configuration of a main part of FIG. 1, and FIG. FIG. 4 is a diagram showing conditions for determining a drive shaft torque, FIG. 4 is a diagram showing data used for calculating an actual drive shaft torque in the embodiment, FIG. 5 is a diagram showing data used for calculating a target engine output torque in the embodiment. FIG. 6 is a diagram showing data used for calculating a throttle opening in the embodiment, FIG. 7 is a diagram specifically showing a configuration of a target opening calculating section in the embodiment, and FIG. 8 is an operation of the embodiment. 5 is a flowchart for explaining FIG. 4 Engine body, 6 Throttle valve, 14 Drive shaft, 30 Throttle-by-wire control section, 40 Traction control section, 50 Auto cruise control section, 70 Main control section, 90 ... Motor drive control unit.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Makoto Shimada 5-33-8 Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Corporation (72) Katsunori Ueda 5-33-8 Shiba, Minato-ku, Tokyo (56) References JP-A-62-26134 (JP, A) JP-A-61-268529 (JP, A) JP-A 64-22637 (JP, A) JP-A-2- 19622 (JP, A) JP-A-2-147439 (JP, A) JP-A-62-203938 (JP, A) JP-A-63-141031 (JP, U) JP-A-61-125641 (JP, U) JP50-50 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) F02D 9/00-11/10 F02D 29/00-29/06 F02D 41/00-45 / 00 395

Claims (1)

(57) [Claims] 1. A vehicle for transmitting an engine output based on an engine output control amount to a drive shaft, comprising: a first target drive shaft torque Twt ₁ according to an accelerator operation amount;
Setting means for determining the second target drive shaft torque Twt ₂ required to converge the wheel slip, and third setting means required to perform constant speed traveling. A third setting means for obtaining a target drive shaft torque Twt _3; and one of the first target drive shaft torque Twt ₁ , the second target drive shaft torque Twt ₂ , and the third target drive shaft torque Twt ₃ Selection means for selecting according to the operating state of the target engine; target engine control amount setting means for obtaining a target engine output control amount required to obtain a target drive shaft torque selected by the selection means; Control means for adjusting the engine output control amount in accordance with the target engine output control amount obtained by the means.