JPH02201036A - Engine output control device - Google Patents

Abstract

PURPOSE:To provide possibility of consolidated installation of various controls by determining the target engine output torques corresponding to the amount of accel. stamping, slippage of car wheel, and constant speed running, and by deciding the target amount of engine output control from these torques. CONSTITUTION:In controlling, first a throttle by-wire control part 30 determines the target value of engine output torque which is in accordance with the amount of accel. pedal 20 stamping. A traction control part 40 determines the target value of engine output torque with which slippage of a wheel 15 can be converged. With turning-on of an auto-cruise switch 60 an auto-cruise control part 50 determines the target value of engine output torque necessary for constant speed running. A main control part 70 determines the target control amount for engine output on the basis of these target values of engine output torque. According to the determined target control amount for engine output, a motor drive control part 90 controls a step motor 7 so as to open and close a throttle vale 6.

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 engine output using, 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 into practical use.

This system does not mechanically connect the accelerator pedal and the throttle valve, but instead detects the depressed position (operation m) of the accelerator pedal, determines the target drive shaft torque from the detected position, and makes sure that the target drive shaft torque is obtained. The motor drives the throttle valve.

An example of the application of this drive-by-wire is so-called throttle-by-wire control, which is control that matches the relationship between accelerator operation and engine output to predetermined conditions that take into account driver sensation and vehicle movement.

In addition, when a wheel slips, there is traction control that reduces the opening of the throttle valve regardless of whether the accelerator pedal is pressed to reduce the slip.

Furthermore, there is an auto cruise control that maintains a desired speed even when the accelerator pedal is released.

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

(Problem to be Solved by the Invention) However, when performing such integration, there is a problem that simply arranging the configurations of each control makes the device large in size.

Further, the final operating means for each control is the throttle valve, and since there is only one throttle valve, there is a problem in that the opening degree control for the throttle valve becomes complicated when integrated.

This invention was made in view of the above circumstances,
The objective is to increase the engine output so that it is possible to integrate accelerator-by-wire control, traction control, and auto-cruise control without increasing the size of the device or complicating the control. The purpose is to provide a control device.

[Structure of the invention] (Means for solving the problem) Target engine output torque Te is adjusted according to the amount of operation of the accelerator.
t4, means for determining a target engine output torque T e12 at which wheel slip can be converged, means for determining a target engine output torque Tet3 necessary for constant speed driving, and these target engine output torques TeJ, T.
means for selecting at least one of et2 and Tet3 according to the driving mode; means for determining a target engine output control amount necessary to obtain the target engine output torque selected by this means; and a target determined by this means. and means for adjusting the engine output control amount in accordance with the engine output control amount.

(Function) Target engine output torque T for throttle-by-wire control
etl, a target engine output torque Tet2 for traction control, and a target engine output torque Tet1 for auto-cruise control, and one of these target engine output torques is selected depending on the driving mode and the like. Then, a target engine output control amount is determined from the selected target engine output torque, and the engine output control amount is adjusted in accordance with the target engine output control amount. The configuration from determining the target engine output control amount to controlling the engine output control amount is commonly used for throttle-by-wire control, traction control, and auto-cruise control.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

In FIG. 1, an air cleaner 1 has an element 2 and an air flow sensor 3. In FIG.

This air flow sensor 3 detects the amount of intake air sucked through the element 2.

An intake passage 5 for introducing combustion air from the air cleaner 1 to the engine body 4 is provided, and a throttle valve 6 is disposed in the middle of the intake passage 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 a fully closed position to a fully open position. A rotating shaft of this throttle valve 6 is connected to a shaft of a step motor 7.

In addition, a torque converter 11 is attached to the output shaft of the engine body 4.
A pump is connected thereto, and a shaft 12 is connected to the turbine of the torque converter 11. Further, a drive shaft 14 is connected to the shaft 12 via a transmission 13, and wheels 15 are mounted on the drive shaft 14.

Note that the torque converter 11, shaft 12, and transmission 13 constitute an automatic transmission.

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

Furthermore, the intake air jlA/Nr calculated by EC116
is supplied to a main control section 70, which will be described later.

In addition, regarding the unit of intake air amount, the following explanation also shows:
Air per revolution ff1A/N is used.

On the other hand, 20 is an accelerator pedal connected to a throttle-by-wire (TBW) control section 30.

This throttle-by-wire control unit 30 detects a depression position Ap as the operation amount of the accelerator pedal 20, and determines a target engine output torque TetI according to the detected position Ap.

Reference numeral 40 denotes a Traxilan 1 control unit, which detects wheel slip from the driven wheel speed Vr and the driving wheel speed V' detected by a sensor (not shown), and determines a target engine output torque Twt2 at which the slip can be converged. be.

Reference numeral 50 denotes an auto-cruise control unit, which sets the auto-cruise mode (AS) by operating the auto-cruise switch 60.
When the mode (C mode) is set, the target engine output torque Tet3 necessary to maintain the vehicle speed constant at that time, that is, necessary for constant speed driving, is determined.

The target engine output torques Tet], Tet2, and TeL3 determined or obtained by these control units are supplied to the main control unit 70.

This main control section 70 controls the target engine output torque Tet1.
．． A functional means for selecting at least one of Tet2 and Tet3 according to the driving mode, and determining a target intake air amount which is a target engine output control amount necessary to obtain the target engine output torque selected by this means. A functional means is provided for determining the target throttle opening degree θ for the throttle valve 6 according to the target intake air amount determined by this means and the intake air amount A/Nr from the EC 116.

In addition, the driving mode is auto cruise switch 6.
Auto cruise mode set by 0 operation,
Slip Q required in traction control section 40
There is a traction mode (TRC mode) that is set when DV is above a certain value.

The target throttle opening degree θ determined by the main control section 70 is supplied to the motor drive control section 90.

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

It drives the step motor 7.

A specific configuration from the throttle-by-wire control section 30 to the motor drive control section 90 is shown in FIG.

First, the throttle-by-wire 30 includes an accelerator pedal position sensor 31 and a target engine output torque determining section 3.
Consists of 2.

The accelerator pedal position sensor 31 is connected to the accelerator pedal 20
For example, a potentiometer is used to detect the depression position Ap of the pedal, and outputs a signal at a voltage level corresponding to the depression position Ap.

The target engine output torque determining unit 32 determines the target engine output torque Tet1 using the accelerator pedal position Ap and the vehicle speed V (driven wheel speed Vf') as parameters. A value that corresponds equally to the accelerator pedal position Ap regardless of the vehicle speed V is determined, and a value that decreases as the vehicle speed V increases is determined when the vehicle speed V exceeds a predetermined value, taking into account speed stability (speed maintenance). It has become. The conditions for this determination are shown in FIG.

The traction control unit 40 includes a differentiator 41 that calculates the vehicle body acceleration from the driven wheel speed Vr, and a reference drive shaft that can be transmitted to the road surface based on the vehicle body acceleration determined by the differentiator 41, the vehicle weight W, and the wheel diameter R that are stored in advance. A reference drive shaft torque calculation unit 42 that calculates torque Two, a reference engine output torque calculation unit 43 that calculates a reference engine output torque Tea from the reference drive shaft torque Two calculated by this calculation unit 42,
A subtraction section 44 that calculates the slip amount DV (-Vr - Vr) by subtracting the driven wheel speed ■r from the driving wheel speed V. A feedback operation amount ΔT() torque amount is calculated from the slip amount DV obtained by this subtraction section 44. ), and an adder 46 that adds the operation amount ΔT multiplied by i by the PID regulator 45 to the reference engine output torque Tea as a correction amount, and based on the reference engine output torque Tea, the slip ff1Dv The target drive shaft torque Tet2 is determined by this feedback.

Here, the reference engine output torque calculation unit 43 calculates a standard necessary to obtain the reference drive shaft torque Two, taking into account the gear ratio ρ of the transmission 13 and the torque ratio τ of the torque converter 11, as shown in the following formula. This is to calculate the engine output torque Tea.

Teo-Two/ (ρf) The auto-cruise control unit 50 converts the actual engine output torque TO11 actually exerted from the engine body 4 into Δp.
a target vehicle speed determination section 52 that determines the driven wheel speed V'' when the auto cruise mode is set by the auto cruise switch 60 as the target vehicle speed Vt; A subtraction unit 53 that subtracts the driven wheel speed vr from the determined target vehicle speed Vt to obtain a speed deviation ΔV, and a PID controller that calculates a feedback operation amount ΔT (torque amount) from the speed deviation ΔV obtained by the subtraction unit 53. 54, this PID regulator 54
The target engine output torque Tet3 is calculated based on the actual engine output torque Te11 and by feedback of the speed deviation ΔV.
is now being sought.

The main control unit 70 receives the target engine output torque Tet1゜”ret2.T supplied from the control unit 30.40.50.
A torque selection unit 71 that selects and outputs one of et3 in response to a command from a selection control unit 75, which will be described later.A target air torque selection unit 71 that determines a target intake air amount A/Nt from a target engine output torque TeL selected by this selection unit 71. a target opening calculation unit 73 that calculates a target throttle opening θ from the target intake air amount A/Nt determined by the calculation unit 72, engine rotational speed Ne, and intake air Rji A/Nr; Output torque Te11. Tet2, Tet3
A torque comparison section 74 that compares the values of
The selection control section 75 controls the selection operation of the selection section 71 according to the comparison result of No. 4, the operation of the auto cruise 60, and the driving mode based on the value of the slip amount DV determined by the traction control section 40.

Here, the target air amount calculation unit 72 stores the relationship shown in FIG. 4 between the intake air amount A/N and the engine output Te as a map (correspondence table), and based on the map, the above The target intake air jilA/Nt corresponding to the target engine output torque Tel is determined. In addition, the fourth
Of course, it is also possible to store the relationship shown in the figure as a formula and use that formula to calculate the target intake air amount A/NL.

The target opening calculation section 73 calculates the target intake air from the target air amount calculation section 72 based on the relationship shown in FIG. 5 between the intake air amount A/N and the throttle opening θ using the engine speed NB as a parameter. The target throttle opening degree θ corresponding to the amount A/Nt is calculated.

In addition, the target opening calculation unit 73 feeds back the intake air amount A/N r as a correction amount when calculating the opening in order to correct the deviation in the intake air amount due to the error in the throttle valve position. There is.

A specific example of this target opening calculation section 73 is shown in FIG.

As shown in FIG. 6, the target intake air amount A/Nt is supplied to a target throttle opening calculation section 701 and a subtraction section 702.

The target throttle opening calculation unit 701 calculates the target intake air ff.
The target throttle opening θ[ is calculated from 1A/Nt and the engine speed Ne.

The subtraction unit 702 calculates the target intake air amount A/Nt and the intake air f.
The deviation from ir A / N r is calculated, and the deviation becomes the operation amount Δθ (opening degree ff1) of the foot check in the PI controller 703. And this manipulated amount Δ
θ is added to the target throttle opening θ by an adding unit 704, so that the final target throttle opening θ is obtained.

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

When the accelerator pedal 20 is depressed, the accelerator pedal position sensor 31 detects the depressed position Ap.

At this time, if the vehicle speed V is in a low speed range, the accelerator pedal position Ap is
The target engine output torque determination unit 32 determines a target engine output torque Tet1 that corresponds equally to . Vehicle speed V
If V is greater than or equal to a predetermined value, the target engine output torque determination unit 32 determines the target engine output torque Tatl, which decreases as the vehicle speed V increases, taking into account speed stability (speed maintenance).

The determined target engine output torque Tet1 is supplied to the main control section 70.

In addition, the traction control unit 40 subtracts the driven wheel speed Vf from the driving wheel speed V to obtain a slip amount DV, and calculates a target engine output torque Tet2 at which the slip can be converged.
seek.

That is, the vehicle body acceleration is obtained from the driven wheel speed Vr, and the reference drive shaft torque Two that can be transmitted to the road surface is calculated from the vehicle body acceleration, the vehicle weight W, and the wheel diameter R that are stored in advance. Furthermore, the reference engine output torque Tea required to obtain the calculated reference drive shaft torque Two is calculated in consideration of the gear ratio ρ of the transmission 13 and the torque ratio τ of the torque converter 11. At the same time, the driven wheel speed V' is subtracted from the driving wheel speed V' and the slip amount DV (
-Vr-vr), and the feedback operation amount ΔT (torque ff1) is obtained from the slip EIDV.

Then, the obtained manipulated variable ΔT is added to the reference engine output torque Tea as a correction amount to obtain the target engine output torque Tet2.

This target engine output torque T et2 is determined by the main control unit 7
0.

The auto cruise control unit 50 constantly measures the actual engine output torque Tel actually exerted from the engine body 4. At the same time, the state of the auto cruise switch 60 is monitored, and when the auto cruise switch 60 is operated to set the auto cruise mode, the driven wheel speed Vr at that time is determined as the target vehicle speed Vt. moreover,
The driven wheel speed ■r is subtracted from the determined target vehicle speed V to obtain a speed deviation ΔV, and the feedback operation amount ΔT is obtained from the speed deviation ΔV. Then, the obtained manipulated variable ΔT is added to the actual engine output torque Tea as a correction amount to obtain the target engine output torque T et3.

This target engine output torque T et3 is determined by the main control unit 7
0.

Note that the auto cruise control unit 50 detects when the auto cruise switch 60 is operated again to cancel the auto cruise mode, or when the brake pedal or accelerator pedal 20 of the vehicle is depressed, and sets the target vehicle speed. Release the determination of Vt.

On the other hand, the main control unit 70 outputs target engine output torques TetITat2 and Tet from the control units 30, 40, 50,
Compare the values of s with each other. In addition, the traction control section 4
If the slip amount DV at 0 is above a certain value, ÷←＾ then set the traction mode (TRC'%l=, mode),
When the slip amount DV is below a certain value, the traction mode is not set. Furthermore, auto cruise switch 60
It is determined whether or not the auto cruise mode (ASC mode) is set.

If the main control unit 70 satisfies the conditions that the main control unit 70 is not in the cruise mode and is not in the automatic cruise mode, the target engine output torque Tetl of the throttle-by-wire control unit 30 is selected.

When the target engine output torque Tetl is selected, the target intake air mA/Nt required to obtain the target engine output torque Tetl is determined, and the target intake air amount A is determined.
The target throttle opening degree θ required to obtain /NL is calculated based on the engine speed Ne and the intake air amount A/Nr.

When the target throttle opening θ is calculated, the step motor 7 is driven according to the calculation result, and the throttle valve 6 is set to the target throttle opening θ.

In this way, the target engine output torque Tet corresponding to the depression position Ap of the accelerator pedal 20 is actually exerted,
This becomes drive shaft torque and is transmitted to the drive shaft 14, and becomes a driving force at the wheels 15.

Furthermore, 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 engine output torque Tet3 of the auto-cruise control unit 50 is selected.

When the target engine output torque Tet3 is selected, the target intake air amount A/Nt and the target throttle opening degree θ are sequentially calculated in the same manner as described above. And throttle valve 6
is set to the target opening degree θ.

In this way, the target engine output torque Tet3 is actually exerted, which becomes the drive shaft torque and is transmitted to the drive shaft 14, and the vehicle is driven at a constant speed of the target vehicle speed Vt.

However, during this constant speed driving, if the auto cruise control is canceled by re-operating the auto cruise switch 60, or if the brake pedal or accelerator pedal 20 is depressed, which corresponds to an auto cruise mode cancellation command, the target Engine output torque Tet3
is deselected and constant speed driving ends.

Furthermore, if the traction mode is set in the main control unit 70 and the condition that the value of the target engine output torque T e12 of the traction control unit 40 is not the maximum is satisfied, that is, the target engine output torque Te
The value of t2 is another target engine output torque Tetl,
If the condition that it is smaller than any value of Tet3 is satisfied, the target engine output torque Tet2 is selected.

That is, the phenomenon that the value of the target engine output torque T et2 becomes small is caused by the occurrence of slip, and the target engine output torque T et2 is selected to ensure safety.

When the target engine output torque T et2 is selected, the target intake air amount A/Nt and the target throttle opening degree θ are sequentially calculated in the same manner as described above. And throttle valve 6
is set to the target opening degree θ.

In this way, the target engine output torque Tet2 is actually exerted, which becomes drive shaft torque and is transmitted to the drive shaft 14, thereby converging the slip.

However, even in the cruise mode, if the value of the target engine output torque Tet2 is the maximum, that is, if no slip occurs, the target engine output torque Tat1 or the target engine output torque depending on the presence or absence of the auto cruise mode. A selection of Tet3 is made.

In this way, by unifying the throttle-by-wire control, traction control, and auto-cruise control using a common element, the target engine output torque Tet, the configuration from the target engine output torque Tet to determining the throttle opening θ can be changed. Can be used for each control.

Therefore, throttle-by-wire control and traction control can be performed without increasing the size of the device.

and auto-cruise control can all be integrated as a drive-by-wire system device.

Moreover, the target engine output torque Tetl of each control,
Since TeL2 and TeL3 are selected according to the magnitude of each value and the operation mode, it is possible to fully utilize the functions of each control without complicating the opening control for the throttle valve 6. In other words, it is possible to ensure improved safety through traction control.

In the above embodiment, the throttle valve is driven by a step motor, but it may be driven not only by a step motor but also by a DC motor. In that case, a throttle opening sensor is provided to detect the opening of the throttle valve. Then, the DC motor is driven so that the detected opening matches the target throttle opening θ. Further, the drive is not limited to motor drive, but may be hydraulic drive or pneumatic drive.

Further, although the explanation has been given using a gasoline engine in which the engine output control amount is the intake air amount, the present invention is similarly applicable to a diesel engine in which the engine output control amount is the fuel injection amount.

In addition, the present invention is not limited to the above embodiments, and can be modified in various ways without departing from the gist.

[Effects of the Invention] As described above, according to the present invention, there are a means for determining the target engine output torque Tet1 according to the amount of operation of the accelerator, and a means for determining the target engine output torque Tet2 at which wheel slip can be converged. , means for determining the target engine output torque Tet3 necessary for constant speed driving, and these target engine output torques Tetl , Tet2 ,
means for selecting at least one of Tet3 according to the driving mode; means for determining a target engine output control amount necessary to obtain the target engine output torque selected by this means; and a target engine output determined by this means. side? 8
Since it is equipped with a means for adjusting the engine output control jil according to the amount of engine output, it is possible to control the accelerator-by-wire control, traction control, and automatic control without increasing the size of the device or complicating the opening control. It is possible to provide an engine output control device that allows integrated integration of cruise control.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an embodiment of the present invention and the configuration of a vehicle related thereto, FIG. 2 is a diagram specifically showing the configuration of the main part of FIG. 1, and FIG. 3 is a diagram showing the goals of the embodiment. FIG. 4 is a diagram showing the conditions for determining the engine output torque. FIG. 4 is a diagram showing the data used to calculate the target engine output torque in the same embodiment. FIG. FIG. 6 is a diagram specifically showing the configuration of the target opening calculation section in the same embodiment, and FIG. 7 is a flowchart for explaining the operation of the same embodiment. 4...Engine body, 6...Throttle valve, 30.
... Throttle-by-wire control section, 40... Traction control section, 50... Auto-cruise control section, 70.
...Main control section, 90... Motor drive control section. Applicant's agent Patent attorney Takehiko Suzue Figure 3 Todoroki = 2. z', to, ＼～仝, 葆ζ工SOGU, -PFig. 6 -Ko-Ring5i-GFig. 7

Claims (1)

[Claims] In a vehicle that transmits engine output to a drive shaft based on an engine output control amount, there is provided a means for determining a target engine output torque Tet_1 according to an accelerator operation amount, and a target engine output torque Tet_1 at which wheel slip can be converged.
means for determining the target engine output torque Tet_3 necessary for constant speed driving; means for selecting one of these target engine output torques Tet_1, Tet_2, and Tet_3 according to at least the driving mode; and means for adjusting the engine output control amount in accordance with the target engine output control amount determined by the means. An engine output control device featuring: