JPH02201038A - Engine output control device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an engine output $-1m device that controls engine output using, for example, a throttle valve.

(Prior Art) In general, an engine output control device called 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 depression position (operation amount) 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.

As an example of the application of this drive-by-wire, there 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 consideration the driver's feeling 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 Problems) A means for determining a target drive shaft torque Twt1 according to the amount of operation of the accelerator, a means for determining a target drive shaft torque Tvt2 at which wheel slip can be converged, Means for determining target drive shaft torque Twt3 necessary for constant speed running, and means for determining target drive shaft torque Twt1. means for selecting at least one of Twt2 and TvL3 according to the driving mode; means for determining a target engine output control amount necessary to obtain the target drive shaft torque selected by this means; and a target determined by this means. means for adjusting the engine output control amount in accordance with the engine output control amount.

(Function) Target drive shaft torque Twt4 for throttle-by-wire control
,) Target drive shaft torque Twt2 for traction control. and target drive shaft torque Twt3 for auto cruise control are generated, and one of these target drive shaft torques is selected depending on the driving mode and the like. Then, a target engine output control amount is determined from the selected target drive shaft torque, and the engine output control amount is increased by 21Mr1 in accordance with the target engine output control amount. The configuration from finding the target engine output control amount to adjusting the engine output control amount is common to 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 amount of the engine output side 8), and can smoothly rotate from a fully closed position to a fully open position. A rotary wheel 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 f detected by the air flow sensor 3
f1A is sent to the engine control computer (hereinafter referred to as ECf) 16, where the intake air per revolution j
; L A / N r is calculated for each predetermined crank angle, and an amount of fuel determined according to the intake air, fl A / N r, is injected into the cylinder of the engine body 4.

Further, the intake air iA/Nr calculated by the EC 116 is supplied to a main control unit 70, which will be described later.

Regarding the 194th intake air amount, the air amount A/N per revolution will be used in the following explanation as well.

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 the depression position Ap as the operation amount of the accelerator pedal 20, and determines the target drive shaft torque TvL1 according to the detected position Ap.

Reference numeral 40 denotes a traction control unit that detects wheel slip from the driven wheel speed vr and drive wheel speed Vr detected by a sensor (not shown), and determines a target drive shaft torque T vt2 at which the slip can be converged.

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 C mode) is set, the target drive shaft torque Twt3 required to maintain the vehicle speed constant at that time, that is, required for constant speed traveling, is determined.

The target drive shaft torques Twtl, Twt2, and 7wt3 determined or obtained by these control units are controlled by the main control unit 7.
0.

This main control section 70 controls the target drive shaft torque TwtI.

Functional means for selecting at least one of Twt2 and Twt3 according to the operating mode; Functional means for determining a target intake air amount as a target engine output control amount necessary to obtain the target drive shaft torque selected by this means; It has a functional means 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 ECl 16.

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

The target slot/sottle 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 stem motor,
The opening degree of the throttle valve 6 is set to the target throttle opening degree θ.

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 drive shaft torque determining section 32.

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 drive shaft torque determination unit 32 determines the accelerator pedal position A.
The target drive shaft torque T Vtl is determined by using P and vehicle speed V (driven wheel speed Vl') as parameters. For example, in a low speed range, the accelerator pedal position Ap is adjusted regardless of the vehicle speed V, taking into consideration the feeling of acceleration when starting. Equally corresponding values are determined, and when the vehicle speed V exceeds a predetermined value, a value that decreases as the vehicle speed V increases is determined in consideration of speed stability (velocity maintenance). The conditions for this determination are shown in FIG.

The traction control unit 40 includes a differentiator 41 that calculates the vehicle acceleration from the driven wheel speed V, and a reference drive that can be transmitted to the road surface from the vehicle acceleration determined by the differentiator 41, the vehicle weight W, and the wheel diameter R stored in advance. The reference drive shaft torque calculation unit 42 that calculates the shaft torque Two subtracts the driven wheel speed Vr from the drive wheel speed Vr and calculates the slip jlDV (−Vr −V
f), a PID adjuster 44 that calculates the feedback operation amount ΔT (torque amount) from the slip amount DV obtained by the subtraction unit 43, and a PID adjuster 44 that calculates the operation amount ΔT obtained by the PID adjuster 44 as a correction amount. The target drive shaft torque Twt2 is determined based on the reference drive shaft torque Two and by feedback of the slip amount DV.

The auto cruise control unit 50 includes an actual drive shaft torque calculation unit 51 that calculates an actual drive shaft torque meter transmitted to the drive shaft 14.
, a target vehicle speed determining section 52 that determines the driven wheel speed Vr when the auto cruise mode is set with the auto cruise switch 60 as the target vehicle speed Vt;
a subtraction unit 53 for subtracting the driven wheel speed vr from the target vehicle speed Vt determined in step 1 to obtain a speed deviation ΔV;
The feedback operation amount Δ is calculated from the speed deviation ΔV obtained by
A PID controller 54 that calculates T () El), this P
It consists of an adding unit 55 that adds the operation amount ΔT obtained by the ID adjuster 54 as a correction amount to the actual drive shaft torque meter, and calculates the target drive shaft torque Twt3 based on the actual drive shaft torque Tv11 and by feedback of the speed deviation ΔV. I'm starting to ask for it.

Here, the actual drive shaft torque calculation unit 51 uses the engine rotation speed Ne detected by an engine rotation speed sensor (not shown), the torque capacity coefficient G, and the torque ratio τ of the torque converter 11 stored in advance, The actual drive shaft torque Tvm is calculated from the following formula.

Tvg-r (e) C(e) Ne2 Note that e is the rotational speed ratio between the output shaft of the engine body 4 and the turbine of the torque converter 11, and using this rotational speed ratio e as a parameter, the torque capacity coefficient C and the torque ratio τ is now determined. This relationship is shown in FIG.

Note that it is also possible to obtain the actual drive shaft torque Tvm by measurement using a torque meter, without using calculation.

The main control unit 70 receives the target drive shaft torque Twt11''Tvg2 supplied from the control units 30, 40.50.

A target drive shaft torque selection section 71 selects and outputs one of 1wt3 in response to a command from a selection control section 76 to be described later, and calculates a target engine output torque Te from the target drive shaft torque Twt selected by this selection section 71. A target engine output torque calculation section 72, a target air amount calculation section 73 that calculates the target intake air ff1A/Nt from the target engine output torque Te obtained by this calculation section 72, and a target air amount calculation section 73 that calculates the target intake air QA/Nt and the engine rotation calculated by this calculation section 73. A target opening calculation unit 74 that calculates the target throttle opening θ from the number Ne and the intake air amount A/Nr, and the target drive shaft torque Twtl+r.
A target drive shaft torque comparison section 75 that compares the values of vt2 and Tvg3, depending on the comparison result of this comparison section 75 and the operation mode based on the operation of the auto cruise 60 and the value of the slip amount DV of the traction control section 40. It consists of a selection control section 76 that controls the selection operation of the selection section 71.

Here, the target engine output torque calculation unit 72 calculates the target required to obtain the target drive shaft torque TvL, 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 Te.

Te = Twt/ (ρτ) The target air amount calculation unit 73 stores the relationship shown in FIG. 5 between the intake air amount A/N and the engine output Te as a map (correspondence table). The target intake air amount A corresponding to the target engine output torque Te based on
/Nt. Note that the relationship shown in Fig. 5 should be memorized as a mathematical formula, and the target intake air f
Of course, it is also possible to calculate f1A/Nt.

The target opening calculating section 74 calculates the target intake from the target air amount calculating section 73 based on the relationship shown in FIG. 6 between the intake air amount A/N and the throttle opening θ using the engine and rotation speed Ne as parameters. The target throttle opening degree θ corresponding to air ff1A/Nt is calculated.

In addition, the target opening calculation unit 74 feeds back the intake air amount A/Nr 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 74 is shown in FIG.

As shown in FIG. 7, target intake air i A /, N t
are the target throttle opening calculation unit 701 and the subtraction unit 702
is supplied to

The target throttle opening calculation unit 701 calculates the target intake air ff.
The target throttle opening degree θt 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 i.
1A/Nr, and the deviation becomes the feedback operation amount Δθ (opening degree m) in the PI regulator 703. Then, this operation amount Δθ is added to the target throttle opening degree θt by an adding section 704, so that the final target throttle opening degree θt can be 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
A target drive shaft torque "rwtl" corresponding equally to "rwtl" is determined by the target drive shaft torque determination unit 32.If the vehicle speed (■) is equal to or higher than a predetermined value, the target drive shaft torque "rwtl" corresponding to The target drive shaft torque Twtl to be decreased is determined by the target drive shaft torque determination unit 32.

The determined target drive shaft torque Twtl is determined by the main control unit 70.
is supplied to

Furthermore, the traffic control unit 40 subtracts the driven wheel speed Vf from the driving wheel speed V to determine the slip amount DV, and determines the target drive shaft torque Tvt2 at which the slip can be converged.

That is, the vehicle body acceleration is determined from the driven wheel speed V, and the reference drive shaft torque Two that can be transmitted to the road surface is calculated from the vehicle body acceleration and the previously stored vehicle body type W and wheel diameter R. Subtract the driven wheel speed Vf from the speed Vr to find the slip 1DV (=Vr - Vr), and obtain the feedback operation amount ΔT () torque amount) from the slip amount DV.Then, the obtained operation amount ΔT is corrected. The target drive shaft torque Twt2 is determined by adding the amount to the reference drive shaft torque Two.

This target drive shaft torque Twt2 is supplied to the main control section 70.

The auto cruise control unit 50 converts the actual drive shaft torque Tvm transmitted to the drive shaft 14 into the engine rotation speed N8 and the torque capacity coefficient C of the torque converter 11.

It is always calculated based on the torque ratio τ. 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 V'' at that time is determined as the target vehicle speed Vt.

Further, the driven wheel speed vr 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 operation amount ΔT is added to the actual drive shaft torque Tval as a correction amount,
Find the target drive shaft torque Tvt3.

This target drive shaft torque Tvt3 is supplied to the main $A control section 70.

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 Vt. cancel the decision.

On the other hand, the main control section 70 mutually compares the values of the target drive shaft torques Twtl, Twt2, and Twt3 from the control sections 30.40.50. Further, if the slip amount DV of the traction control unit 40 is above a certain value, the traction mode (crRck mode) is set, and when the slip 11DV is below the certain value, the traction mode is not set. Furthermore, it is determined whether the auto cruise mode (ASC mode) is set by the auto cruise switch 60.

If the main control unit 70 satisfies the conditions that the vehicle is not in the traction mode and is not in the autocruise mode, the target drive shaft torque Twt1 of the throttle-by-wire control unit 30 is selected.

When the target drive shaft torque Twt+ is selected, the target engine output torque Te required to obtain the target drive shaft torque Twt1 is calculated in consideration of the gear ratio ρ of the transmission 13 and the torque ratio r of the torque converter 11. Ru. Then, the target intake air amount A/Nt required to obtain the target engine output torque Te is determined, and the target throttle opening θ required to obtain the target intake air amount A/Nt is determined based on the engine rotation speed Ne and the intake air amount A/Nt. It is calculated based on the 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 drive shaft torque Twtl corresponding to the depression position Ap of the accelerator pedal 20 is actually exerted and transmitted to the drive shaft 14, and becomes a driving force at the wheels 15.

Further, in the main control section 70, if the condition that the mode is not the traction mode but the auto cruise mode is satisfied, the target drive shaft torque Twt3 of the auto cruise control section 50 is selected.

When the target drive shaft torque Twt3 is selected, the target engine output torque T(3) required to obtain the target drive shaft torque Twt3 is calculated, and the target intake air amount A/Nt and target throttle opening are calculated in the same manner as above. θ is sequentially calculated, and the throttle valve 6 is set to the target opening θ.

In this way, the target drive shaft torque Tvt3 is actually exerted and transmitted to the drive shaft 14, and constant speed running at the target vehicle speed Vt is achieved.

However, during this constant speed driving, if the auto cruise mode is canceled by re-operating the auto cruise switch 60, or if the brake pedal or accelerator pedal 20 is depressed, which corresponds to the auto cruise mode cancellation command, the target The selection of drive shaft torque Twt3 is canceled, 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 drive shaft torque T Vt3 of the traction control unit 40 is not the maximum is satisfied, that is, the value of the target drive shaft torque T Vt2 is Other target drive shaft torque T'vtl.

If the condition that it is smaller than any value of Tvt3 is satisfied, the target drive shaft torque Twt2 is selected.

That is, the phenomenon in which the value of the target drive shaft torque T Vt2 decreases is due to the occurrence of slip, and the target drive shaft torque T Vt2 is selected to ensure safety.

When the target drive shaft torque Twt2 is selected, the target engine output torque TO necessary to obtain the target drive shaft torque Twt2 is calculated, and the target intake air j is calculated in the same manner as above.
tA/Nt and target throttle opening θ are calculated in sequence. Then, the throttle valve 6 is set to the target opening degree θ.

In this way, the target drive shaft torque T vt2 is actually exerted and transmitted to the drive shaft 14, thereby converging the slip.

However, even in the traction mode, if the value of the target drive shaft torque Twt2 is the maximum, that is, if no slip occurs, the target drive shaft torque Twtl or the target drive shaft torque T depending on the presence or absence of the auto cruise mode.
A selection of vt3 is made.

In this way, by unifying throttle-by-wire control, traction control, and auto-cruise control using a common element, the target drive shaft torque Twt, the configuration from the target drive shaft torque Twt to finding 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.

Furthermore, the target drive shaft torque TvJ for each control.

7wt2 and Twt3 are selected according to the magnitude of each value and the operation mode, so the functions of each control can be fully utilized 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 6 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, the opening detected by the throttle opening sensor 8 is taken in and the The DC motor is driven so that the detected opening matches the target throttle opening θ. Moreover, the drive is not limited to a motor, and may be driven by hydraulic pressure or pneumatic pressure.

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-mentioned embodiments, and various modifications can be made without changing the gist.

[Effects of the Invention] As described above, according to the present invention, means for determining the target drive shaft torque Twtl according to the amount of operation of the accelerator;
Target drive shaft torque Twt2 at which wheel slip can be converged
means for determining the target drive shaft torque Twt3 necessary for constant speed traveling;
means for selecting at least one of Tl, Twt2, and 7wt3 according to the driving mode; means for determining a target engine output control amount necessary to obtain the target drive shaft torque selected by this means; Since the engine output control amount is adjusted according to the target engine output control amount to be determined, the accelerator-by-wire control and traction control can be performed without increasing the size of the device or complicating the control. It is possible to provide an engine output control device that enables integral integration of control and auto-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. A diagram showing the conditions for determining the drive shaft torque, FIG. 4 is a diagram showing data used for calculating the actual drive shaft torque in the same embodiment, and FIG. 5 is a diagram showing data used for calculating the target engine output torque in the same embodiment. FIG. 6 is a diagram showing the data used for calculating the throttle opening in the same embodiment, FIG. 7 is a diagram specifically showing the configuration of the target opening calculation section in the same embodiment, and FIG. 8 is the operation of the same embodiment. It is a flowchart for explaining. 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 section. Figure 3 Applicant's agent Patent attorney Takehiko Suzue Figure 4 A/N- Figure 6 Noah 4 Figure

Claims (1)

[Claims] In a vehicle that transmits an engine output based on an engine output control amount to a drive shaft, a means for determining a target drive shaft torque Twt_1 according to an accelerator operation amount, and a means for determining a target drive shaft torque Twt_2 at which wheel slip can be converged. and the target drive shaft torque Twt_3 required for constant speed driving.
means for determining these target drive shaft torques Twt_1,
means for selecting at least one of Twt_2 and Twt_3 according to the driving mode; means for determining a target engine output control amount necessary to obtain the target drive shaft torque selected by this means; and a target determined by this means. An engine output control device comprising: means for adjusting the engine output control amount in accordance with the engine output control amount.