JPH02221650A - Method of controlling engine output of vehicle - Google Patents

Abstract

PURPOSE:To particularly improve accelerating property in a one having main and sub-throttle valves by making possible to control the opening of the sub- throttle valve in consideration of the opening of the main throttle valve interlocking with an accelerator pedal to make the engine output to a target engine torque. CONSTITUTION:A main throttle valve THm the opening theta1 of which is operated by an accelerator pedal and a sub-throttle valve THs the opening theta2 of which is controlled by the opening signal thetas from a traction controller are provided in an intake passage, and the driving force of an engine is controlled by controlling the sub-throttle valve THs. In this case, a target intake air quantity per engine rotation required to generate a target engine torque calculated according to the driving state is calculated, and based on the calculation result, the equivalent throttle valve opening thetah when the main and sub-throttle valves THm, THs are assumed as one equivalent throttle valve is calculated. The thetah is corrected with a correction factor read from the openings thetah, theta1 to calculate the sub-throttle valve opening theta2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a method for controlling the engine output of a vehicle so that the engine output of the vehicle reaches a target engine output.

(Prior Art) Conventionally, an acceleration slip prevention device (traction slip prevention device) has been used to control the engine so that the engine output reaches a predetermined target engine torque. control device) is known. In such a traction control device, when acceleration slip of the driving wheels is detected, the slip rate S is controlled so that the coefficient of friction μ between the tire and the road surface is within the maximum range (shaded range in FIG. 18).

Here, the slip rate S is [(VP - VB) / V
P]X100 (%), vF is the wheel speed of the driving wheels, and VB is the vehicle body speed. In other words, when slip of the drive wheels is detected, the engine output is controlled so that the slip ratio S falls within the shaded range.
The friction coefficient μ between the tires and the road surface is controlled to be within the maximum range, thereby preventing the drive wheels from slipping during acceleration and improving the acceleration performance of the vehicle.

(Problem to be solved by the invention) In such a traction control device,
When a slip of the driving wheels is detected, it is required to control the engine output to a target engine output at which no slip occurs.

For example, in a traction control device that has a main throttle valve that is linked to the accelerator pedal and a sub-throttle valve that is electrically controlled in the intake path of the engine,
In order to obtain the target engine output, it is necessary to control the opening degree of the sub-throttle sottle valve in consideration of the opening degree of the main throttle valve.

The present invention has been made in view of the above points, and its object is to provide an engine output control device in which a main throttle valve linked to an accelerator pedal and an electrically controlled sub-throttle valve are provided in the intake path of an engine. An object of the present invention is to provide an engine output control method for a vehicle that can accurately control the opening degree of a sub-throttle valve so that the engine output becomes a target engine torque.

[Structure of the Invention] (Means and effects for solving the problem) A main throttle valve whose opening degree Θ1 is controlled according to the operation amount of an accelerator pedal in an intake path to a vehicle engine, and its opening degree electrically. In the engine output control device that controls the output of the engine, a target engine torque that the engine should output is calculated by providing a sub-throttle valve whose e2 is controlled and controlling the opening e2 of the sub-throttle valve. a target engine torque calculation means; a target intake air amount calculation means for calculating a target intake air amount per engine revolution necessary to generate the target engine torque; Equivalent throttle valve opening calculation means for calculating the equivalent throttle opening θh when the above-mentioned main and sub throttle valves are assumed to be one equivalent throttle valve, and the relationship between the equivalent throttle opening θh and the main throttle valve opening e1 and a sub-throttle valve opening calculation means for calculating the sub-throttle valve opening e2 by correcting the equivalent throttle opening Θh using the correction coefficient. This is a control method.

(Embodiment) Hereinafter, an acceleration slip prevention device for a vehicle in which a vehicle engine output control method according to an embodiment of the present invention is adopted will be described with reference to the drawings. FIG. 1 is a configuration diagram showing an acceleration slip prevention device for a vehicle. The figure shows a front wheel drive vehicle, where WPR indicates the right front wheel, WPL indicates the left front wheel, WRR indicates the right rear wheel, and WRL indicates the left rear wheel. Also, 11 is the front right wheel (drive wheel)
WPI? Wheel speed VF [? A wheel speed sensor 12 detects the wheel speed VF of the front left wheel (drive wheel) WFL.
The wheel speed sensor that detects L, 13 is the rear right wheel (driven wheel) WRI? Wheel speed VI? A wheel speed sensor 14 detects the wheel speed VRL of the rear left wheel (driven wheel) WRL. Wheel speeds VFR and VF detected by the wheel speed sensors 11 to 14
L, VRR, VRL are traction controller 1
5 is input. This traction controller 15 has an intake air temperature AT detected by an intake air temperature sensor (not shown).
, atmospheric pressure AP detected by an atmospheric pressure sensor (not shown), engine rotation speed Ne detected by a rotation sensor (not shown)
, Intake air ff1A/N per engine rotation cycle detected by an air flow sensor (not shown), Transmission oil temperature OT detected by an oil temperature sensor (not shown)
.

The engine cooling water temperature WT detected by a water temperature sensor (not shown), the operating state of the air conditioner switch (not shown), the operating state of the power steering switch SW (not shown), the operating state of the idle switch (not shown), the power steering pump oil temperature OP1 (not shown), the pipe (not shown) From the cylinder internal pressure CP of the engine detected by an internal pressure sensor, the combustion chamber wall temperature CT of the engine detected by a combustion chamber wall temperature sensor (not shown), the excitation current iΦ of the alternator, and the timer (not shown) that counts the time after the engine starts. The elapsed time τ after startup to be output is input. The traction controller 15 sends a control signal to the engine 16 to perform control to prevent the drive wheels from slipping during acceleration. This engine 16 is the first
As shown in figure (A), the opening degree θ is adjusted by the accelerator pedal.
In addition to the main throttle valve THm, which is operated by the traction controller 15, an opening signal es, which will be described later, is sent from the traction controller 15.
The sub-throttle valve THs whose opening degree e2 is controlled by
have. The opening e2 of the sub-throttle valve THs is determined by the motor drive circuit 52 controlling the rotation of the motor 52i based on the opening signal θS from the traction controller 15.

The driving force of the engine 16 is controlled by controlling the opening degree θ2 of the sub-throttle valve THa in this manner. Note that the opening degree of the main throttle valve THffi and the sub-throttle valve THs is 81. θ2 is detected by throttle position sensors TPSI and TPS2, respectively, and output to the motor drive circuit 52. Further, a bypass passage 52b is provided between the upstream and downstream sides of the main and auxiliary throttle valves THa+ and THs to ensure the amount of intake air during idling, and the opening amount of this bypass passage 52b is controlled by a stepper motor 52s. be done. Further, a bypass passage 52c is provided between the upstream and downstream sides of the main and sub throttle valves THm and THs, and this bypass passage 52c has a wax valve whose opening degree is adjusted according to the cooling water temperature WT of the engine 16. 52W is provided.

Further, 17 is a wheel cylinder that brakes the front right wheel WFR, and 18 is a wheel cylinder that brakes the front left wheel WPL. These wheel cylinders are normally supplied with pressurized oil when a brake pedal (not shown) is operated. When traction control is activated, pressure oil can be supplied from another route as described below.

Pressure oil is supplied from the hydraulic source 19 to the wheel cylinder 17 through an inlet valve 17i, and pressure oil is discharged from the wheel cylinder 17 to the reservoir 20 through an outlet valve 17o. Further, pressure oil is supplied from the hydraulic source 19 to the wheel cylinder 18 through an inlet valve 18i, and pressure oil is discharged from the wheel cylinder 18 to the reservoir 20 through an outlet valve 180. The inlet valves 17i and 181. Opening and closing control of the outlet valves 170 and 18o is performed by the traction controller 15.

Next, the detailed configuration of the traction controller 15 will be described with reference to FIG. 2.

In the same figure, 11 and 12 are drive wheels WFI? , W.F.L.
The driving wheel speeds VFR and VPL detected by the wheel speed sensors 11 and 12 are both detected by the high vehicle speed selection unit 31.
and sent to the averaging section 32. The high vehicle speed selector 31 selects the higher wheel speed of the drive wheel speeds VFR and VPL, and the drive wheel speed selected by the high vehicle speed selector 31 is outputted to a weighted section 33. Ru. Further, the averaging section 32 calculates an average driving wheel speed (VFl?+VPL)/2 from the driving wheel speeds V FR and V PL obtained from the wheel speed sensors 11 and 12. The average drive wheel speed calculated by is outputted to the weighted section 34. The weighting section 33 is a weighting section 33 that selects and outputs the drive wheels WPR and WP selected by the high vehicle speed selection section 31.
The higher wheel speed of L is multiplied by KG (variable), and the weighting section 34 multiplies the average driving wheel speed output by the averaging section 32 by (1-KG) (variable). in,
The driving wheel speed and the average driving wheel speed weighted by the weighting units 33 and 34 are sent to an adding unit 35 and added, thereby calculating the driving wheel speed VP.

Here, the variable KG is a variable that changes according to the centripetal acceleration GY, as shown in FIG.
is proportional to the magnitude of the value up to a predetermined value (for example, 0.1 st), and is set to be "1" above that value.

On the other hand, the driven wheel speeds VRR and VRL detected by the wheel speed sensors 13 and 14 are both sent to a low vehicle speed selection section 36 and a high vehicle speed selection section 37. The low vehicle speed selection section 36 selects the low wheel speed side of the driven wheel speeds VRR and VRL, and the high vehicle speed selection section 37 selects the low wheel speed side of the driven wheel speeds VRR and VRL.
It selects the high wheel speed side of RR and VRL, and the low driven wheel speed selected by the low vehicle speed selection section 36 is weighted in the section 38, and the low driven wheel speed selected by the high vehicle speed selection section 37 is weighted. The high driven wheel speed is outputted to a weighted section 39.

The weighting unit 38 multiplies (variable) the lower wheel speed of driven wheels WRR and WRL selected and output by the low vehicle speed selection unit 36, and the weighting unit 3 Driven wheel WRR selected and output by high vehicle speed selection section 37,
The higher wheel speed of WRL is multiplied by (1-Kr) (variable), and in the multi-weighting, the driven wheel speed weighted by sections 38 and 39 is given to an adding section 40 and added. , the driven wheel speed VR is calculated. This addition section 4
The driven wheel speed VR calculated at 0 is output to the multiplier 40'. This multiplier 40' multiplies the additionally calculated driven wheel speed VR by (1+α).
′ and the driven wheel speed VRR,VI? A target drive wheel speed Vφ based on L is calculated.

Here, the above-mentioned variable " is a variable that changes between "1" and "0" according to the centripetal acceleration GY, as shown in FIG.

Then, the driving wheel speed v calculated by the adding section 35
F and the target driving wheel speed Vφ calculated by the multiplication section 40' are given to the subtraction section 41.

This subtraction unit 41 subtracts the target driving wheel speed Vφ from the driving wheel speed vF, and calculates the slip f of the driving wheels WPR, WFL.
This is to calculate f1DVi' (VF-Vφ), and the slip amount DVi' calculated by the subtraction section 41 is given to the addition section 42. This adder 42 converts the slip EIDVi' into centripetal acceleration GY and its rate of change Δ
The slip correction iVg (see FIG. 5), which is corrected according to the centripetal acceleration GY and changes according to the centripetal acceleration GY, is given from the slip amount correction section 43, and is adjusted according to the rate of change Δ of the centripetal acceleration GY.
A slip correction amount Vd (see FIG. 6) that changes according to GY is given from the slip amount correction section 44. That is, in the addition section 42, the slip mD obtained from the subtraction section is
V i ' 4 slip corrections f21Vg and Vd are added, and the slip ff1DVi, which is corrected in accordance with the centripetal acceleration GY and its rate of change ΔGY, is obtained by adding the four slip corrections f21Vg and Vd, for example, over a sampling time T of 15m5. It is sent to the TSn calculation section 45 and the TPn calculation section 46 for each time.

The calculation unit 45a in the TSn calculation unit 45 multiplies the slip amount DVi by the coefficient Kl and calculates the integral correction torque TSn' (纏ΣKl DV i), which is obtained by multiplying the slip amount DVi by the coefficient Kl. The information is sent to section 45b. In other words, the integral correction torque TSn' is a correction value for the drive torque of the drive wheels WFR, WFL, and is the correction value for the drive torque of the drive wheels WPR.

It is necessary to adjust the control gain according to changes in the speed change characteristics of the power transmission mechanism existing between the WFL and the engine 16.
The integral correction torque TSn' obtained from a is multiplied by a coefficient GKi that differs depending on the gear position to calculate the integral correction torque TSn corresponding to the gear position. Here, the above variable K
I is a coefficient that changes depending on the slip amount DVi.

On the other hand, the calculation section 46a in the TPn calculation section 46 calculates the proportional correction torque TPn' (=DVi-Kp) by multiplying the slip amount DVL by the coefficient Kp. 46b. In other words, this proportional type correction torque TPn' is also similar to the above-mentioned integral type correction torque TSn'.
, WPL is a correction value for the drive torque of the drive wheels WPR, WI'L, and the control gain thereof needs to be adjusted in accordance with changes in the speed change characteristics of the power transmission mechanism existing between the drive wheels WPR, WI'L and the engine 16. The coefficient multiplier 46b calculates the proportional correction torque TS obtained from the arithmetic unit 46a.
By multiplying n' by a coefficient GKp that varies depending on the gear position, a proportional correction torque TPn corresponding to the gear position is calculated.

On the other hand, the driven wheel speed VR obtained by the addition section 40 is sent to the reference truth calculation section 47 as the vehicle body speed vB. The reference torque calculation section 47 first calculates the acceleration GB of the vehicle speed VB in a vehicle acceleration calculation section 47a, and the vehicle acceleration GB obtained by the vehicle acceleration calculation section 47a is passed through a filter 47b as a vehicle acceleration GBP. It is sent to the reference torque calculation unit 47c. This reference torque calculation unit 47c calculates a reference torque TG (-G
BPxWx Re ), and this reference torque TO becomes the axle torque value that the engine 16 should originally output.

Next, the reference torque TG calculated by the reference torque calculation section 47 is output to the subtraction section 48.

This subtraction section 48 subtracts the integral correction torque TSn calculated by the TSn calculation section 45 from the reference torque TG obtained from the reference torque calculation section 47, and the subtraction data is further sent to the subtraction section 49. It will be done. This subtraction unit 49 further subtracts the proportional correction torque TPn calculated by the TPn calculation unit 46 from the subtraction data obtained from the subtraction unit 48, and the subtraction data drives the drive wheels WPR, WFL. Target torque Tφ of the axle torque to be
engine torque converter 500 via switch S1 as
sent to. In other words, Tφ-TG-TSn-TPn.

The filter 47b determines, for example, in three stages how far in time the reference torque TG calculated by the reference torque calculating section 47c is calculated based on the vehicle body acceleration GB. The vehicle body acceleration GBP is the vehicle body acceleration GBn detected this time and the vehicle body acceleration GB which is the output of the filter 47b up to the previous time.
Pn-1 is calculated according to the current slip ratio S and acceleration state.

For example, if the slip rate S is currently in the state shown in the range "1" in FIG. 15 while the acceleration of the vehicle is increasing, in order to quickly shift to the state "2", the vehicle body acceleration GBP is the output of the previous filter 47b, G
The latest vehicle acceleration GBF is calculated by averaging BPn-1 and the currently detected GBn with the same weighting using the following equation (1).

GBFn −(GBn+GBFn −1) /2
- (1) For example, if the acceleration of the vehicle is currently decreasing and the slip rate S is S>Sl and shifts to the range r2J - r3J shown in FIG. In order to maintain the state of ”, the vehicle body acceleration GBF
is calculated by the following equation (2) as the vehicle body acceleration GBPn having a value close to the previous output GBFr+-1 of the filter 47b.

GBFn-(GBn+7GBPn-1)/8-(2
)Furthermore, for example, when the acceleration of the vehicle is currently decreasing, the slip rate S is S≦81 and r2J as shown in FIG.
- If you have migrated to rlJ, the range “
In order to return to the state of ``2'', the vehicle body acceleration GBP is further weighted on the previous output GBPn-1 of the filter 47b, and the previously calculated vehicle body acceleration GBFn is Vehicle acceleration G with a value close to -1
BFn is calculated by the following formula (3).

GI3Fn −(GBn+15GBPn −1) /1
B ・= (3) Next, the reference torque calculation section 47
The reference torque TG calculated by is output to the subtraction section 48.

This subtraction section 48 subtracts the integral correction torque TSn calculated by the TSn calculation section 45 from the reference torque TG obtained from the reference torque calculation section 47, and the subtraction data is further sent to the subtraction section 49. It will be done. This subtraction unit 49 further subtracts the proportional correction torque TPn calculated by the TPn calculation unit 46 from the subtraction data obtained from the subtraction unit 48, and the subtraction data drives the drive wheels WFR, WPL. Target torque Tφ of the axle torque to be
engine torque converter 500 via switch S1 as
sent to. In other words, Tφ-TO-TSn-TPn.

This engine torque conversion section 500 converts the drive wheels WFR, WF given from the subtraction section 49 via the switch S1.
The target torque Tφ for L is divided by the total gear ratio between the engine 16 and the drive wheel axle to convert it into the target engine torque T1. This target engine torque T1 is output to the torque converter response delay correction section 501. The torque converter response delay correction section 501 corrects the engine torque TI according to the response delay of a torque converter (not shown) and outputs a target engine torque T2. This target engine torque T2 is output to the 17M (transmission) friction correction section 502.

In this T/M friction correction section 502, an engine torque loss due to friction in the transmission is added to the target engine torque T2 to obtain a target engine torque T3. This target engine torque T3 is output to external load correction section 503. In this external load correction section 503, the target engine torque T
The target engine torque T4 is calculated by adding the loss of engine torque due to electrical loads such as air conditioners to T3.

This target engine torque T4 is output to the atmospheric condition correction section 504. In the atmospheric condition correction section 504, the target engine torque T4 is corrected to a target engine torque T5 based on atmospheric conditions, that is, atmospheric pressure AP. Further, the target engine torque T5 is determined by the operating condition correction section 5.
It is output on 05. In this operating condition correction section 505, the target engine torque T5 is determined based on the operating condition of the engine.
For example, target engine torque T6 is corrected according to engine coolant temperature WT and output to lower limit value setting section 506.

This lower limit value setting section 506 sets the target engine torque To
For example, as shown in FIGS. 16 and 17, the lower limit value of the target engine torque T7 is set by limiting the lower limit value Tl1m that changes depending on the elapsed time t from the start of traction control or the vehicle speed VB. It is output to the amount calculation unit 507. In this target air amount calculation unit 507, the target air amount (mass) per engine rotation for outputting the target engine torque T7!A/NI! l is calculated.

This target air amount calculation unit 507 calculates a target air amount (quality ff1) A/N m per engine rotation for outputting the target engine torque T7 in the engine 16.
This target air amount A/N m
is determined based on the engine rotational speed Ne and target engine torque T7 with reference to the three-dimensional map shown in
Mass) A/Nm is determined.

A/Nm -r [Ne, T7] Here, A/Nm is the intake air amount (mass) per engine rotation, f' [Ne, T7] is the engine rotation speed Ne, and the target engine torque T7. This is a three-dimensional map with parameters.

Further, in the target air amount calculation unit 507, the target air amount (quality ff1) A/Nm is calculated from the intake air temperature A by the following formula.
It is corrected by T and atmospheric pressure AP and converted into a target air amount (volume) A/Nv under standard atmospheric conditions.

A/Nv=(A/N+n)/fKt
(AT) Book Kp (AP)
1 Here, A/N v is the amount of intake air (volume) per engine revolution, Kt is the density correction coefficient using the intake air temperature (AT) as a parameter (see Figure 36), and Kp is the atmospheric pressure (AP). This is the density correction coefficient (see FIG. 37) used as a parameter.

The target air amount A/Nv (volume) is determined by the target air amount correction section 5.
08, correction is performed based on the intake air temperature, and target air ff1A/NO is calculated using the following formula.

A/NO-A/NV * Ka' (AT) where A/NO is the target air volume after correction, A/N v is the target air volume before correction, and Ka/ is the correction coefficient based on intake air temperature (AT). (See Figure 38).

The target air amount A/NO is sent to the equivalent target throttle opening calculating section 509, and the three-dimensional map shown in FIG. 39 is referred to to calculate the equivalent target throttle opening eb for the engine rotational speed Ne and target air ff1A/No. It will be done. This equivalent target throttle opening θb is the throttle valve opening for achieving the target air flA/No when there is one throttle valve. Furthermore, equivalent target throttle opening eb
If there are bypass passages 52b and 52c that bypass the sub-throttle valve THs, the equivalent target throttle opening is equal to the opening Δe corresponding to the amount of air flowing through the bypass passages 52b and 52c calculated by the eb correction unit 511. eb
is subtracted from. That is, in the subtraction section 510, the equivalent target throttle opening Θh obtained by subtracting the opening Δet from the equivalent target throttle opening eb is sent to the target throttle opening calculation section 512, and the main throttle valve TH
By multiplying the throttle opening e1 of IB by the correction coefficient K stored in the map shown in FIG. 40, the throttle opening θ2 of the sub-throttle valve THs is calculated.

On the other hand, the corrected target air amount A/NO outputted from the target air amount correction section 508 is also sent to the subtraction section 513. This subtraction unit 513 calculates the deviation ΔA/N between the target air fiA/NO and the actual intake air amount A/N detected by the air flow sensor at each predetermined sampling time. The deviation ΔA/N between NO and the actual air amount A/N is sent to the PID control section 514. This PID control unit 507 calculates an opening correction amount Δe2 of the sub-throttle valve THs corresponding to the deviation ΔA/N, and this sub-throttle valve opening correction amount Δe2 is calculated by the adding unit 51.
Sent to 5.

Here, the sub-throttle valve opening correction amount Δe2 obtained by the PID control unit 514 is the sum of the opening correction amount Δep1 by proportional control, the opening correction amount Δe1 by integral control, and the opening correction amount Δed by differential control. It is.

Δe2−Δep+Δe1+Δed Δep 榔Kp (Ne) Book Kth(Ne) Book Δ A/NΔei
−Kl (Ne) *Kth (Ne) *Σ(ΔA/N)Δed −
Kd (Ne) * Kth (Ne) books (Δ
A/N - Δ A/No1d) Here, each coefficient Kp
, Kl, and Kd are a proportional gain (see Figure 40), an 82nd minute gain (see Figure 41), and a differential gain (see Figure 42) with the engine rotation speed Ne as a parameter, and Kth is a proportional gain (see Figure 42) using the engine rotation speed Ne as a parameter. ΔA/N → Δθ conversion gain as a parameter (see Figure 43) ΔA/N is the deviation between the target air amount A/NO and the actual air amount A/N, Δ
A/N Old is ΔA/N at the previous sampling timing.

The addition unit 515 adds the target throttle opening e2 corrected by the opening correction unit 510 and the sub-throttle valve opening correction amount Δe2 calculated by the PID control unit 514, and The degree er is calculated. This target opening degree ef is sent to the motor drive circuit 52 as a sub-throttle valve opening signal es. This motor drive circuit 52 is connected to the throttle position sensor TPS.
The rotation of the motor 52m is controlled so that the opening e2 of the sub-throttle valve THs detected by the sub-throttle valve THs becomes equal to the opening corresponding to the sub-throttle valve opening signal es.

By the way, the wheel speed V R1 of the driven wheel? , VI? L
is sent to the centripetal acceleration calculating section 53, and the centripetal acceleration GY' is determined in order to determine the degree of turning. This centripetal acceleration GY' is sent to the centripetal acceleration correction section 54, and the centripetal acceleration GY' is corrected according to the vehicle speed.

In other words, GY-Kv-GY'. Here, Kv is the vehicle body speed VB as shown in FIGS. 7 to 12.
This is a coefficient that changes depending on the

The wheel speed of the larger driven wheel outputted from the high vehicle speed selection section 37 is determined by the subtraction section 55 as the wheel speed VFR of the driving wheel.
is subtracted from. Further, the higher driven wheel speed output from the high vehicle speed selection section 37 is subtracted from the driving wheel speed VPL in a subtraction section 56.

The output of the subtraction unit 55 is multiplied by KB (0
<KB<1), and the output of the subtraction section 56 is outputted to the multiplication section 58.
After being multiplied by (1-KB) in the adding section 59, it is added to the slip amount DVFR of the right drive wheel.

At the same time, the output of the nose reduction section 56 is multiplied by KB in a multiplication section 60, and the output of the subtraction section 55 is multiplied by (1-KB) in a multiplication section 61, and then added in an addition section 62. The slip amount is DVPL.

As shown in Fig. 13, the variable KB changes according to the elapsed time from the start of the traction control, and when the traction control starts, rO
, 5J, and is set to approach rO, 8J as the traction control progresses.

The slip amount DVPR of the right drive wheel is differentiated in a differentiator 63 to calculate its temporal variation, that is, the slip acceleration GFR, and the slip 1iDVPL of the left drive wheel is differentiated in a differentiator 64 to calculate its temporal change. The amount of change, that is, the slip acceleration GFL is calculated. The slip acceleration GPR is then sent to the brake fluid pressure change amount (ΔP) calculating section 65, and the slip acceleration GPR shown in FIG.
The FR(GFL) - ΔP conversion map is referred to to determine the amount of change ΔP in brake fluid pressure for suppressing slip acceleration GPR. The amount of change ΔP in brake fluid pressure is
Up.

The signal is sent to the ΔP-T conversion unit 67 via the switch S2, which is controlled to open and close by the start/end determination unit 50.
The opening time T of the inlet valve 171 at ) is calculated. Similarly, the slip acceleration GPL is sent to the brake fluid pressure change amount (ΔP) calculation unit 66, and the G PR (G FL) - ΔP conversion map shown in FIG. 14 is referred to to suppress the slip acceleration GFL. The amount of change ΔP in brake fluid pressure for this purpose is determined. This brake fluid pressure change amount ΔP is sent to the ΔP-T conversion unit 68 via the switch S3, which is controlled to open and close by the start/end determination unit 50, and is sent to the opening time T of the inlet valve 181 in FIG. 1(A). is calculated. Then, the inlet valve 17i and outlet valve 18i calculated as described above.
The valve is controlled to open for the opening time of , and the brakes are applied to the right drive wheel WPR and the left drive wheel WPI.

The switches 81 to S3 are opened and closed in conjunction with each other by the start/end determining section 50.

By the way, the slip flD calculated by the subtraction unit 41
VI' is sent to the differentiator 41a, and the slip amount DV
A temporal change rate ΔDVi' of i' is calculated. The above slip EIDVi', its temporal change rate ΔDvi
', the opening e2 of the sub-throttle valve THs, and the output torque Te of the engine 16 detected by a torque sensor (not shown) are output to the start/end determining section 50. This start/end determination section 50 performs the above slip tk D V 1
When the temporal rate of change ΔDVI' and the engine torque To both exceed their respective reference values, the switches 81 to S3 are closed to start control, and the opening degree θ2 of the sub-throttle valve THs is becomes larger than a predetermined reference value or DV' becomes smaller than a predetermined reference value (different from the above reference value), the switch 5t-S
3 is opened to end the control.

In addition, in Fig. 14, when applying the brakes when turning, in order to strengthen the brakes on the inner drive wheels,
The converted value on the inner wheel side during a turn is shown by a broken line a.

Next, the operation of the vehicle engine output control method according to an embodiment of the present invention configured as described above will be described. In FIG. 1 and FIG. 2, wheel speed sensors 1B, 1
The wheel speed of the driven wheel (rear wheel) output from the high vehicle speed selection section 36. Low vehicle speed selection section 37. It is input to the centripetal acceleration calculation section 53.

In the low vehicle speed selection section 36, the smaller wheel speed of the left and right driven wheels is selected, and the high vehicle speed selection section 37
In , the wheel speed of the larger one of the left and right driven wheels is selected. When the wheel speeds of the left and right driven wheels are the same during normal straight-line driving, the low vehicle speed selection section 3
The same wheel speed is selected from 6 and the high vehicle speed selection section 37. In addition, the wheel speeds of the left and right driven wheels are input to the centripetal acceleration calculation unit 53, and the turning angle when the vehicle is turning, that is, how steep the turn is, is determined from the wheel speeds of the left and right driven wheels. The degree to which the

Hereinafter, how the centripetal acceleration is calculated in the centripetal acceleration calculating section 53 will be explained.

In a front-wheel drive vehicle, since the rear wheels are driven wheels, the vehicle speed at that position can be detected by the wheel speed sensor regardless of slip caused by the drive, so Ackermann geometry can be used. In other words, in a steady turn, the centripetal acceleration GY' is GY' -v2/r
-(4) (V-vehicle speed, r-turning radius).

For example, when the vehicle is turning to the right as shown in FIG. 19, the turning center is set to MO, and the turning center Mo
When the distance from to the inner wheel side (WRR) is rl, the tread is Δr, the wheel speed of the inner wheel side (WI?R) is vl, and the wheel speed of the outer wheel side (WRL) is v2, then v2 /vl-(Δr+rl)/rl ・= (
5).

Then, by transforming the above equation (5), 1/rl = (v2-vl)/Δr・vl −(
6). Then, the claimed center acceleration GY' characterized by the inner ring side is GY' mvl 2 / rl −vl 2 (v2 − vL )/Δ r −
vl-vl (v2-vl)/Δ r ・
... Calculated as (7).

That is, the centripetal acceleration GY' is calculated by the above equation (7). By the way, when turning, the inner wheel speed vl is smaller than the outer wheel speed ■2, so the centripetal acceleration GY' is calculated using the inner wheel speed v1, so the centripetal acceleration GY' is smaller than the actual one. Calculated. Therefore, the coefficient KG multiplied in the weighting section 33 is the centripetal acceleration G
Since Y' is estimated to be small, it is estimated to be small.

Therefore, since the driving wheel speed vp is estimated to be small,
The slip amount DV' (VF-VΦ) is also estimated to be small. As a result, since the target torque TΦ is estimated to be large, the target engine torque is also estimated to be large, thereby providing sufficient driving force even when turning.

By the way, at extremely low speeds, the distance from the inner wheels to the turning center MO is rl, as shown in Figure 19, but in a vehicle that understeers as the speed increases, the turning center is at M. The distance is r(r>r
l).

Even when the speed increases in this way, since the turning radius is calculated using rl, the centripetal acceleration GY' calculated based on the above equation (7) is calculated as a larger value than the actual value. Therefore, the centripetal acceleration GY' calculated in the centripetal acceleration calculation section 53 is calculated by the centripetal acceleration correction section 54.
The centripetal acceleration GY' is multiplied by the coefficient Kv shown in FIG. 7 so that the centripetal acceleration GY becomes small at high speeds. This variable Kv is set to decrease according to the vehicle speed, and may be set as shown in Section 8 or FIG. 9. In this way, the centripetal acceleration correction unit 54 outputs the corrected centripetal acceleration GY.

On the other hand, as the speed increases, oversteer occurs (r<
(rl) In the vehicle, the centripetal acceleration correction unit 54 performs a correction that is completely opposite to that of the above-mentioned understeered vehicle. In other words, as the vehicle speed increases, the centripetal acceleration GY' calculated by the centripetal acceleration calculating section 53 is
is corrected so that it becomes larger.

By the way, the smaller wheel speed selected in the low vehicle speed selection section 36 is multiplied by the variable Kr in the weight section 38 as shown in FIG. 4, and the high vehicle speed selected in the high vehicle speed selection section 37 is not weighted. In part 39, the variable (1-Kr
) will be multiplied. The variable Kr is the centripetal acceleration GY of 0.9, for example.
It is set to "1" when the turning becomes larger than g, and becomes "0" when the centripetal acceleration GY becomes smaller than 0.4 g.
is set to

Therefore, for a turn in which the centripetal acceleration GY is greater than 0.9 g, the wheel speed of the lower vehicle speed among the driven wheels output from the low vehicle speed selection section 36, that is, the wheel speed of the inner wheel at the time of selection is selected. be done.

Then, the weighting is performed by adding the wheel speeds output from sections 38 and 39 in an adding section 40 to obtain the driven wheel speed VR.
Further, the driven wheel speed VR is multiplied by (1+α) in a multiplier 40' to obtain the target driving wheel speed VΦ.

Further, after the higher wheel speed of the drive wheels is selected in the high vehicle speed selection section 31, weighting is performed in the section 33.
In this case, the variable KG is multiplied as shown in FIG. Furthermore, the average vehicle speed (V
FR+VFL) /2 is weighted in section 34, and (1
-KG) and the above weighting is the output of the section 33 and the adding section 3
5 is added to obtain the driving wheel speed VF. Therefore, if the centripetal acceleration GY becomes, for example, 0.1g or more, KG
-1, so the 2 output from the high vehicle speed selection section 31
The wheel speed of the larger of the two drive wheels is output. In other words, when the turning angle of the vehicle increases and the centripetal acceleration GY becomes, for example, 0.9 g or more, rI
(In order to achieve G-Kr-IJ, for the driving wheel side, the wheel speed of the outer wheel side where the wheel speed is higher is set as the driving wheel speed VP, and for the driven wheel side, the wheel speed of the inner wheel side where the wheel speed is lower is set as the driven wheel speed V.
R, the slip amount DVi' (-VF-VΦ) calculated by the subtraction unit 41 is estimated to be large. Therefore, in order to estimate the target torque TΦ to be small,
The output of the engine is reduced, the slip ratio S is reduced, and the lateral force A can be increased as shown in Fig. 18, and the grip force of the tires during cornering is increased to enable safe cornering. Can be done.

The above slip ff1DVi is the slip amount correction section 43
In this case, a slip correction ffiVg as shown in FIG. 5 is added only when turning when centripetal acceleration GY occurs, and a slip m V d as shown in FIG. 6 is added in the slip amount correction section 44.

For example, if we assume a turn at a right angle,
In the first half of the turn, the centripetal acceleration GY and its rate of change over time ΔGY take positive values, but in the second half of the curve, the rate of change over time ΔGY of the centripetal acceleration GY takes a negative value.

Therefore, in the first half of the curve, in the adding section 42,
The slip amount DVi' is the slip correction amount V shown in FIG.
g (>0) and the slip correction amount Vd (
>O) is added to the slip Hk D V i,
In the latter half of the curve, the slip correction amount Vg (>0) and the slip correction = vd (<0) are added and the slip f
f1DVi. Therefore, the slip ff1DVi in the second half of the turn is the slip m D in the first half of the turn.
By estimating it to be smaller than Vi, engine output is reduced and lateral force is increased in the first half of the turn,
In the second half of the turn, the engine output is recovered more than in the first half to improve the acceleration of the vehicle.

In this way, the corrected slip amount DVi is sent to the TSn calculation unit 45 at a sampling time T of, for example, 15 m5. In this TSn calculating section 45, the slip amount DVL is multiplied by a coefficient Kl and integrated to obtain a correction torque TSn.

That is, the correction torque obtained by correcting the slip ff1DVi, that is, the integral correction torque TSn is obtained as TSn=GKI ΣKl-DVI (Kl is a coefficient that changes according to the slip ff1DV1).

Further, the slip ff1DVI is sent to the TPn calculation unit 46 at every sampling time T, and the correction torque TPn
is calculated. That is, the correction torque corrected by the slip 11DVi, that is, the proportional correction torque TPn is obtained as TPn - GKp DVI -Kp (Kp is a coefficient).

Furthermore, the values of the coefficients GKI and GKp used in the calculations in the coefficient multipliers 45b and 46b are switched to values corresponding to the gear position after the shift after a set time from the start of the shift during upshifting. This is because it takes time from the start of the shift until the gear is actually switched and the shift is completed, and when the above-mentioned coefficients GKi and GKp corresponding to the high gear after the shift are used at the time of upshifting, the above-mentioned correction torque TS
Since the values of n and TPn correspond to the above-mentioned high speed gear, they become smaller than the values before the start of the shift even though the actual shift has not finished, and the target torque TΦ becomes large, inducing slip and causing control. This is because it becomes unstable.

Further, the driven wheel speed VR output from the addition section 40 is inputted to the reference torque calculation section 47 as the vehicle body speed VB. Then, the vehicle body acceleration calculating section 47a calculates the acceleration VB (GB) of the vehicle body speed. Then, the acceleration GB of the vehicle body speed calculated in the vehicle body acceleration calculation section 47a is processed by the filter 47b using the formulas (1) to (3).
) is applied to keep GBP at an optimal position depending on the state of acceleration CB.

For example, if the acceleration of the vehicle is currently increasing and its slip ratio S is in the range "1" shown in FIG. 15, in order to quickly shift to the state in the range "2",
1) As shown in the formula, the vehicle body acceleration GBF is calculated by combining GBFn-1, which is the output of the previous filter 47b, and GBn detected this time.
The latest vehicle acceleration G BF is calculated by averaging with the same weighting.
Calculated as n.

Further, for example, when the acceleration of the vehicle is currently decreasing, the slip rate S is in the range r2J shown in FIG. 15 when s>si.
- When migrating to r3J, the range “
2'', the vehicle body acceleration GBF is calculated as the previous vehicle body acceleration GBFn by weighting the previous output of the filter 47b as shown in equation (2) above.

Furthermore, for example, when the acceleration of the vehicle is currently decreasing, the slip rate S is S≦81 and is in the range "2" shown in FIG.
→If it moves to “1”, please use the range “1” as much as possible.
In order to return to the state of "2", the vehicle body acceleration GBF is changed to the above (3
), the previous output of the filter 47b is heavily weighted and further calculated as the previous vehicle body acceleration GBFn.

Then, the reference torque calculation unit 47c calculates the reference torque TG (-GBFxWxRe).

The reference torque TG and the integral correction torque T
Subtraction with Sn is performed in a subtraction unit 48, and the proportional correction torque TPn is further subtracted in a subtraction unit 49. In this way, the target drive shaft torque TΦ is calculated as TΦ-TG-TSn-TPn.

This target drive shaft torque TΦ is input to the engine torque converter 500 via switch S1, and is divided by the total gear ratio between the engine 16 and the drive wheel axle to calculate the target engine torque T1. This target engine torque TI is corrected for the response delay of the torque converter in a torque converter response delay correction section 502, and is set as a target engine torque T2. This target engine torque T2 is T/M
The torque is sent to the friction correction section 502, where it is corrected for friction in the transmission interposed between the engine and the drive wheels, and is set as the target engine torque T3.

The T/M friction correction unit 502 estimates the warm-up state of the 77M and corrects the target engine torque T3 using the first to fourth methods described below.

<First method of 77M friction correction> This first method detects the oil temperature OT of 77M with an oil temperature sensor, and if this oil temperature OT is small, the friction is large, so the second method is
The torque correction HkTr is added to the target engine torque T2 with reference to the map shown in FIG. In other words, T3-T2 +Tf(OT). In this way, since the torque correction amount Tf' due to friction is determined according to the oil temperature QT of 77M, it is possible to accurately correct the target engine torque with respect to the friction of 77M.

<Second method of 77M friction correction> Engine 16
The cooling water temperature WT of 77M is measured by a sensor, the warm-up state (oil temperature) of 77M is estimated from this, and the torque is corrected. In other words, T3-T2 +Tf (VT). Here, the torque correction amount Tf (WT) is calculated by referring to a map (not shown) and calculating the engine cooling water temperature WT.
It is estimated that the lower the 77M oil temperature OT is, the larger the torque correction amount Tr is set. In this way, since the friction of 77M is estimated from the engine cooling water temperature VT, a sensor for detecting the oil temperature OT of 77M is unnecessary.

<Third method of 77M friction correction> Engine 16
Based on the coolant temperature VTO immediately after the start of the engine and the real-time coolant temperature WT, the map in FIG. 21 is referred to, and the torque correction ff1Tf is added to the target engine torque T2.
The target engine torque is set as T3. That is, T3-72 +Tf (XT) XT-WT+KO* (WT-WTO). Here, XT is the estimated oil temperature of 77M, and KO is the ratio of the temperature increase rate of the engine cooling water temperature WT to the temperature increase rate of the T/M oil. The relationship between the estimated oil temperature XT, engine cooling water temperature WT, T/M oil temperature OT, and elapsed time after engine startup is shown in FIG. As shown in FIG. 22, the change in the estimated oil temperature XT as the starting time elapses is approximately equal to the change in the oil temperature OT as the starting time elapses. Therefore, the oil temperature can be accurately monitored without using an oil temperature sensor.

<Fourth method of 77M friction correction> Engine 16
cooling water temperature WT, elapsed time τ after engine start, vehicle speed Vc
Based on T2+Tf'(WT)$1l-Kas(r)
*Kspeed (V c ) Calculated as 1.

Here, Kas is the tailing coefficient depending on the time after starting (τ) (a coefficient that gradually approaches 0 as time passes after starting), and Kspeed is the tailing coefficient depending on vehicle speed (a coefficient that gradually approaches 0 as the vehicle speed increases). It shows.

In other words, if a sufficient amount of time has passed since the engine was started, or if the vehicle speed has increased (...the heat term is "0")
” approach. Therefore, if sufficient time has passed since the engine was started or the vehicle speed has increased, the 77
The torque correction amount Tf due to the friction of M is eliminated.

<Fifth method of 77M friction correction> The output is corrected based on the rotational speed N of the engine or 77M. The map in Fig. 23 is referred to based on the rotational speed N, and the torque is corrected based on the rotational speed N. ff1Tf' is calculated. In other words, T3-T2 +Tf (N). This is because as the rotational speed N of the engine or 77M increases, the oil temperature of 77M increases and friction loss decreases.

<Sixth method of 77M friction correction> Engine 16
This is a method to obtain the corrected torque by estimating from the integrated value of the cooling water temperature and the intake air amount Q after starting, and T3-72 +TI' (WT) * fl-Σ(
The target engine torque T3 is obtained as KQ*Q)1. Here, Kq is a coefficient that converts the amount of intake air into torque loss, and in an idling state when the clutch is off or the idle SW is on, Kq
−Kql, otherwise Kq −KqO(>
Kql).

In the above formula, Σ(K q * Q ) is obtained by multiplying the intake air amount Q after the engine starts by a coefficient Kq,
The product of (1-Σ(Kql:Q)) and the torque correction amount Tr (WT) based on the engine cooling water temperature WT is added to the target engine torque T2. By doing this, when the vehicle is suddenly accelerated after the engine starts and the intake air HQ increases rapidly, that is, even if the engine coolant temperature WT is low, the transmission is sufficiently warmed up and the 77M friction correction is performed. When it is not necessary, (...) the heat term is set to 0 immediately to eliminate unnecessary torque correction.Also, in the idling state, by setting Kq to a small value, , even if the idling condition continues, the transmission is not sufficiently warmed up, so the intake air ff
Estimate the 1Q integration to be as small as possible than the actual value, and make torque correction ff1Tf' based on the engine coolant temperature.
I try to make the most of it.

In this way, even if the idling state continues, the above Tr (VT) term is left, and the 77M
Friction correction is performed. Note that the integration of the intake air ff1Q for each fixed time period is calculated based on the intake air ff1A/N per engine cycle.

Further, the T/M friction torque Tf' may be calculated using a three-dimensional map shown in FIG.

In this case, the target engine torque T3 is expressed as shown below. In other words, T3-T2 +TI' (WT,
ΣQa) By the way, in FIG. 24, Tf' is set to be "0" when ΣQa exceeds a certain value. This is because when the total amount of intake air exceeds a certain value, it is determined that the T/M oil has been sufficiently warmed and the T/M friction can be ignored.

<Seventh method of T/M friction correction> Engine 16
The torque correction ff1 is determined based on the cooling water temperature WT or the oil temperature of the engine 16 and the mileage ΣVS after the engine starts.
Find T1'. In other words, T3-T2 +Tf' (
WT) iE fl-Σ(K V*V S)1 Here, Kv is a coefficient that converts the traveling distance (-ΣVs) into output correction, and is in an idling state where the idle SW is on or the clutch is off. is set to Kv - Kvl, otherwise Kv - Kv2
(>Kvl).

In the above formula, Σ(KvFVs) is obtained by multiplying the mileage ΣVs after the engine starts by the correction coefficient Kv, and (1-Σ(Kv Vs)) is calculated as the engine cooling water temperature V
The product multiplied by the torque correction amount Tf' (WT) based on T is added to the target engine torque T2. By doing this, when the vehicle travels after the engine starts and its travel distance increases, the (...) term is set to "0" to eliminate unnecessary torque correction.

Furthermore, since the load on the transmission is small in the idling state, the oil temperature in the transmission increases moderately. For this reason, torque losses in the transmission decrease only gradually.

Therefore, by setting Kv to a small value in the idling state, the torque correction value is slowly brought to "0" and the torque correction Tf is performed for as long as possible. .

Next, the target engine torque T3 output from the T/M friction correction section 502 is sent to the external load correction section 503, and if there is an external load such as an air conditioner, the target engine torque T3 is corrected and the target engine The torque is assumed to be T4. This correction by the external load correction section 503 is performed by one of the first to third methods described below.

First Method of External Load Correction> The target engine torque T3 is corrected to become the target engine torque T4 according to the air conditioner load. In other words, T4-T3 +TL. Here, TL is set to a constant value when the air conditioner is on, and is set to "0" when the air conditioner is off. In this way, when there is an air conditioner load, the loss torque TL corresponding to the air conditioner load is added to the target engine torque T3 to obtain the target engine torque T4, thereby preventing a decrease in engine output due to the air conditioner load. There is.

Also, focusing on the fact that the magnitude of the air conditioner load changes according to the engine rotation speed Ne, the loss torque T L according to the engine rotation speed Ne is stored in a map as shown in FIG. The target engine torque T4 may also be calculated.

In other words, T4-T3 +TL CNe) It's good as well.

Second method of external load correction> The target engine torque T is adjusted according to the power steering load.
3 is corrected and set as the target engine torque T4. In other words, T4-73 +TL. Here, TL is set to a constant value when the power steering is on, and is set to "0" when the power steering is off. In this way, when there is a power steering load, the loss torque TL corresponding to the power steering load is added to the target engine torque T3 to obtain the target engine torque T4, thereby reducing the reduction in engine output due to the power steering load. It is prevented.

Also, focusing on the fact that the magnitude of the power steering load changes depending on the power steering pump oil pressure OP, the loss torque TL corresponding to the power steering pump oil pressure OP is stored in a map as shown in FIG. The target engine torque T4 may also be calculated. In other words, T4-7
3 +TL (OP) may also be used.

Third method of external load correction> Correct the target engine torque T3 according to the electrical load,
Target engine torque T4 is being determined.

In other words, the electrical loads such as headlights and electric fans fluctuate, and the amount of power generated by the alternator goes up and down. Therefore, by detecting the battery voltage and the excitation current of the alternator, the amount of power generated by the alternator is estimated, and the electric load is estimated.

Target engine torque T when battery voltage is vb
4 is as follows.

T4-T3 +TL (Vb'') Here, the loss torque TL (Vb) has a relationship with the battery voltage vb as shown in Fig. 27.In other words, it is estimated that the lower the battery voltage vb, the greater the electrical load. The loss torque T L is increased, and the target engine torque T4 is increased.

Further, the target engine torque T4 is obtained by adding the loss torque using the alternator excitation current (iΦ) as a parameter. In other words, T4-T3 +TL (
iΦ, Ne). Here, the loss torque TL is determined with reference to the map shown in FIG.

Also, from the characteristic diagram shown in FIG. 29, the engine rotation speed Ne
The target engine torque T4 may be calculated from the following equation by obtaining the alternator efficiency correction amount K for the alternator efficiency.

T4-T3 +TL (fΦ, Ne)XK (Ne)
The target engine torque T4 calculated as described above is sent to the atmospheric condition correction section 504, and the target engine torque T4 is corrected according to the atmospheric pressure to become a target engine torque T5. In other words, T5-74 +Tp (AP
) Here, Tp is the torque correction amount shown in the map of FIG. That is, in areas with low atmospheric pressure, such as highlands, the engine output increases due to a reduction in pumping loss and an increase in combustion speed due to a reduction in back pressure, so the torque correction mTp is reduced accordingly.

In this way, the target engine torque T5 corrected based on the atmospheric pressure is sent to the operating state correction section 505, and the target engine torque T5 is corrected according to the operating state of the engine, that is, the warm-up state, and the target engine torque is It is assumed to be T6. Hereinafter, first to third methods for determining the operating state correction according to the warm-up state of the engine 16 will be described.

First method for correcting engine operating conditions> The target engine torque TO is calculated based on the engine coolant temperature wT. The map in Fig. 31 is referred to and the torque correction amount TV is calculated according to the engine coolant temperature VT. The target engine torque T6 is added to the target engine torque T5. In other words, TO-T5 +TV (WT). As shown in FIG. 31, the lower the cooling water temperature 1/T is, the less the engine 16 is warmed up, so the torque correction ff1TW is increased.

In addition, the above torque correction ff1TW is changed to the engine cooling water temperature ν
It is also possible to map T and engine rotation speed Ne (not shown). In other words, TO-T5 +TW
(WT, Ne).

Second method for correcting engine operating conditions This second method is to add a torque correction 1iTas(τ) according to the time τ after engine startup to the target engine torque T5 as shown in FIG. Therefore, the target engine torque T6
I am getting . In other words, TO-75+Ta5(r). In this way, the warm-up state of the engine is estimated based on the elapsed time τ after engine startup.

In addition, torque correction W is performed using a three-dimensional map (not shown) determined by the time τ after engine start and the cooling water temperature WT.
It is also possible to obtain T as. In other words, it may be T8-T5 + Tas Cr, WT).

By using such a map, the cooling water temperature w'ro at the time of startup is measured, and the torque correction fi is determined according to the elapsed time τ.
The torque correction ffi Tas may be determined by determining Tas or by measuring the cooling water temperature WT at the elapsed time τ.

Third Method for Correcting Engine Operating Conditions> In this third method, the torque correction amount Tj is determined from the engine oil temperature OT with reference to the map shown in FIG. In other words, it is calculated as T6-75 +Tj (OT). In this way, the engine cooling water temperature WT is estimated from the engine oil temperature OT to detect the warm-up state of the engine.

Note that the torque correction amount Tj may be obtained from a three-dimensional map of the engine oil temperature OT and engine rotational speed Ne (not shown). In other words, T8-T5 +Tj
(OT, Ne) may also be used.

Fourth method for correcting engine operating conditions> This fourth method uses engine cooling water temperature WT, oil temperature OT, elapsed time τ after startup, combustion chamber wall temperature CT, intake air AM QH cylinder pressure C
The target engine torque T6 is obtained by correcting the target engine torque T5 using a portion of P. In other words, T8-T5 +Tc (CT/CTO) *Kcp
(cp/cpO) * f 1-Kq
This is considered to be Σ (Q)).

Here, CT is the combustion chamber wall temperature of the engine, and CTO is the combustion chamber wall temperature at the time of engine startup. Tc is the torque correction based on the ratio of the combustion chamber wall temperature CT to the combustion chamber wall temperature CTO at the time of engine startup (CT/CTO). CP is the cylinder pressure of the engine, CPO is the cylinder pressure at engine start, Kcp is the cylinder pressure CP above and cylinder pressure CP at engine start.
The correction coefficient Kq based on the ratio (CP/CPO) to O is a coefficient that converts the integrated value of the intake air amount after starting into a torque correction coefficient.

As described above, the target engine torque T6 after being corrected according to the engine operating conditions is determined by the lower limit value setting unit 506.
In this case, the lower limit value of engine torque is limited. In this way, by controlling the lower limit value of the target engine torque T6 with reference to FIG. 16 or FIG. 17, it is possible to prevent the target engine torque from becoming too low and causing an engine stall.

Then, the target engine torque T7 output from the lower limit value setting section 506 is sent to the target air amount calculation section 507, where the target air il (mass) A/Nm for outputting the target engine torque T7 is calculated. .

The target air amount calculation unit 507 refers to the three-dimensional map shown in FIG. 34 from the engine rotation speed Ne and the target engine torque Tel, and calculates the target air amount (mass m) A/Nm
is required. In other words, A/Nm = f [Ne
, T7].

Here, A/Nm is the amount of intake air per intake stroke (wage), and f [Ne, T] is the engine rotation speed NB.

This is a three-dimensional map using target engine torque T7 as a parameter.

In addition, A/N11ll is a coefficient Ka and a target engine torque T as shown in FIG. 35 for the engine rotational speed Ne.
It may be multiplied by 7, that is, A/Nm-Ka(Ne)*T7. Furthermore, Ka (Ne) may be used as a coefficient.

Further, in the target air amount calculation unit 507, the intake air amount (mass) A/Na is corrected based on the intake air temperature and atmospheric pressure, and the intake air amount (volume) A/N under standard atmospheric conditions is corrected.
It is converted to v.

In other words, A / N v = (A/Nm) / fKt (AT) * K
p (AT) ). Here, A/Nν is the intake air ff1 (volume) per engine revolution, Kt is the density correction coefficient using the intake air temperature (AT) as a parameter as shown in Figure 37, and Kp is the density correction coefficient as shown in Figure 38. It shows a density correction coefficient using atmospheric pressure (AT) as a parameter.

The thus calculated target intake air amount A/Nv (volume) is corrected by the intake air temperature in the target air amount correction section 508, and is set as the target air amount A/NO.

In other words, A/N0 - A/Nv * Ka' (AT).

Here, A/NO is the target air amount after correction, A/N
v is the target air amount before correction, and Ka' is the correction coefficient (Fig. 38) based on the intake air temperature (AT).

Thereafter, the target air amount A/No output from the target air amount correction section 508 is sent to the equivalent target throttle opening calculation section 509, and the three-dimensional map in FIG.
The equivalent throttle opening degree θb for f1A/No and the engine rotational speed Ne is determined. This equivalent throttle opening eb is determined by the subtraction unit 510 as the equivalent throttle opening eb.
The opening degree Δe1 calculated by the eb correction unit 511 as described below is subtracted from the equation to obtain the equivalent throttle opening Θ.
h.

The above Δe% is determined by the following formula. In other words, Δe<-
Ks (e) * (Sm +Sv (νT)
1 Here, the coefficient Ks (Fig. 46) is the step motor 52 controlled by an ISO (idle speed controller), not shown, with the target opening degree e as a parameter.
8, the opening correction amount per step, Sm is the number of steps of the step motor 52s, and Sv (Fig. 47) is the opening degree of the wax valve 52W using the engine cooling water temperature WT as a parameter to the number of steps of the step motor 52S. This is the conversion value to be converted.

Then, the target throttle opening calculation unit 512 multiplies the equivalent throttle opening θh by the correction coefficient K shown in FIG.
is required.

Here, a method for calculating the target throttle opening θ2 of the sub-throttle valve THs performed by the target throttle opening calculating section 512 will be described with reference to FIG. 41. As shown in FIG. 1(B), main and sub throttle valves THm are connected in series with the intake path.

When THs are arranged, the equal air amount characteristic curve Q
1 to Q3 are substantially symmetrical about the straight line el-82, and their respective curves are substantially similar with the origin as the focal point. Here, the equal air amount characteristic curves Q1 to Q3 are the opening degree 81 of the main throttle valve THm and the opening degree e2 of the sub throttle valve THs when the intake air amount is set to a constant value of Q1 to Q3, respectively.
It shows the relationship between

For example, the intersection of el/θ2-0.87 and curve Q3 is A
shall be. In the characteristic curve Q3, the opening e2 of the sub throttle valve THs when the opening θ1 of the main throttle valve THm is set to the fully open position (WOT) (in this case, since the main throttle valve THm is fully open, the same opening θ2 is equal to the equivalent throttle opening when the main throttle valve THm and the sub-throttle valve THs are considered as one throttle valve, and the equivalent throttle opening at this time is called Θh) is 0 of the throttle opening e2 at point A. It becomes .625 times.

In other words, a straight line a3 that moves downward from point A while keeping the throttle opening e1 constant and a horizontal tangent b3 between the characteristic curve Q3
The opening degree e2 at the intersection A' with the above target opening degree Θh. This is because the tangent b3 indicates the opening degree θ2 of the sub throttle valve THs when the opening degree 611 of the main throttle valve TH1llI is WOT in the characteristic curve Q3.

By the way, the straight line connecting the intersection A' and the origin is e1/Θh-
α, hereinafter referred to as straight line α. And the characteristic curve Ql
, Q2 and the straight line el/e2-0.87 are intersected by B and C, respectively, and the projection point of the above B and C points onto the straight line α is B.
', C', triangles OAA', OBB',
The OCC's are similar with the origin as a common vertex. On the other hand, since the characteristic curves Q1 to Q3 are similar to each other with the origin as the focal point, if the horizontal tangent b3 of the characteristic curve Q3 passes through the point A', then the horizontal The tangent lines bl and b2 in the direction pass through the points B' and C', respectively.

Therefore, when the opening e1 of the main throttle valve THm is set as WOT from the state of point B of the characteristic curve Q2, the opening e2 of the sub throttle valve THs is at a position (B ' point), and when the opening el of the main throttle valve THI11 is set to WOT from the state of the 0 point of the characteristic curve Q3, the opening e2 of the sub throttle valve THs is 0.825 times the y-coordinate value of the above 0 point. position (point C'). Similarly to point A', point B' and point Cr also indicate the equivalent throttle opening Θh in each characteristic curve.

Therefore, θ1/e2-0.67, θh -0,8
From the relationship with 25*θ2, θ1/Θh-1,072, so point A' B r point C1 is a straight line θ1/θh-
It will be tied at 1,072.

In this way, the value of el /e2 and the value of 01 /Θh correspond to one body. Therefore, the straight line eL/θ2 (-
By changing the slope of α), the value of el /Θh (
−β) is obtained in advance from FIG. 41, and θl−θh
, θ1-e2 lines α, θ2-Θh lines (β/α) are calculated. In other words, the correction coefficient K(-β/α
), the opening degree e2 of the sub throttle valve THs is calculated. In other words, as shown in Figure 40, el
/Θh−β1. β2. By calculating the correction coefficient K for .

By the way, the corrected target air HA/No outputted from the target air amount correction section 508 is sent to the subtraction section 513, and the difference from the current air HA/N detected by the air flow sensor at every predetermined sampling time is calculated. ΔA/N is calculated. This ΔA/N is sent to the PID control unit 514, and ΔA/N is
PID control is performed based on /N, and an opening correction amount Δe2 corresponding to ΔA/N is calculated. This opening correction amount Δe
2 is the target throttle opening degree e2 in the addition section 51.
The feedback-corrected target opening degree θr is calculated every predetermined sampling time.

19r-92+Δθ2. Here, the opening correction amount Δe is the opening correction amount Δep1 by proportional control, and the opening correction amount Δθ1 by integral control.
, the opening degree correction amount Δθd by differential control is added. In other words, Δe−Δep+Δθ1+Δθd.

Here, Δep = Kp (No) * Kth (Ne) *
ΔA/NΔ81 −Kl (No) * Kth (N
o) * Σ (ΔA/N) Δed −Kd(No)
*Kth (Ne)*(ΔA/N−ΔA/No1d
l is calculated by the PID control unit 514. Here, Kp, Kl, and Kd are proportional, integral, and differential gains with the engine rotational speed Ne as a parameter;
The characteristic diagrams are shown in FIG. 44. Also, Kt
h is ΔA/N- with engine speed Ne as a parameter
Δe conversion gain (Figure 45), ΔA/N is the target air amount A
The deviation between /No and the measured current air Ei A/N, ΔA/N Old, is ΔA/N at the previous sampling timing.

The target opening degree er determined as described above is sent to the motor drive circuit 52 as the sub-throttle valve opening signal θS. The motor drive circuit 52 controls the rotation of the motor 52m so that the opening e2 of the sub-throttle valve THs detected by the sensor TPS2 corresponds to the opening signal θS.

Incidentally, the higher driven wheel speed output from the high vehicle speed selection section 37 is subtracted from the wheel speed VFR of the driving wheels in the subtraction section 55. Further, the higher driven wheel speed output from the high vehicle speed selection section 37 is subtracted from the driving wheel speed VFL in a subtraction section 56.

Therefore, the outputs of the subtraction units 55 and 56 are estimated to be small, so that the number of times the brake is used during turns is reduced, and the slip of the drive wheels is reduced by reducing the engine torque.

The output of the subtraction unit 55 is multiplied by KB (0
<I(B<1), and the output of the subtraction section 56 is the output of the multiplication section 5.
8 is multiplied by (1-KB), and then added in five adders to obtain the slip mDVPR of the right drive wheel. At the same time, the output of the subtraction section 56 is multiplied by KB in a multiplication section 60, and the output of the subtraction section 55 is multiplied by (1-KB) in a multiplication section 61, and then added in an addition section 62 to produce the output of the left driving wheel. Slip EtDVFL.

As shown in Fig. 13, the variable KB changes according to the elapsed time t from the start of traction control, and when the traction control starts, r
o, 5 J, and is set to approach rO, 8 J as the traction control progresses. In other words, when reducing the slip of the driving wheels by braking, the brakes are applied simultaneously to both axles at the beginning of braking to reduce the unpleasant steering shock when braking starts on a split road, for example. Can be done. On the other hand, brake control is continued and
The operation when the above KB becomes rO, 8J will be explained. In this case, when slip occurs in only one drive wheel, brake control is performed by recognizing that slip has occurred in the other drive wheel by 20% of that of the one drive wheel.

This is because if the brakes on the left and right drive wheels are made completely independent, only one drive wheel will be braked, and when rotation decreases, the opposite drive wheel will slip and brake due to the action of the differential, and this operation will be interrupted. This is because it is repeated and is not desirable. The slip mDVPR of the right drive wheel is differentiated in a differentiator 63 to calculate the amount of change over time, that is, the slip acceleration GPR, and the slip amount D V P L of the left drive wheel is differentiated in a differentiator 64. The amount of change over time, that is, the slip acceleration GFL is calculated. And the above slip acceleration GF
R is sent to the brake fluid pressure change amount (ΔP) calculation unit 65, and the GFR (GFL)-ΔP conversion map shown in FIG. is required.

Furthermore, the amount of change ΔP is Δ that calculates the opening time T of the inlet valve 171 when the switch S2 is opened, that is, when the start/end determining section 50 determines that the control start condition is satisfied.
The signal is applied to the P-T converter 67. That is, the valve opening time T calculated by the ΔP-T converter 67 is taken as the brake operation time FR of the right drive wheel WFR. Similarly, the slip acceleration GFL is the brake fluid pressure change ff1(Δ
G PR(
G FL) - ΔP conversion map is referred to, and the amount of change ΔP in brake fluid pressure for suppressing slip acceleration GPL is determined.
is required. This amount of change ΔP is given to the ΔP-T conversion unit 68 that calculates the opening time T of the inlet valve 181 when the switch S3 is closed, that is, when the start/end determination unit 50 determines that the control start condition is satisfied. In other words, ΔP−T
The valve opening time T calculated by the converter 68 is set as the brake operating time FL of the left drive wheel WPL. This prevents the left and right drive wheels WFR, WFL from causing more slip.

In addition, in Fig. 14, when applying the brakes when turning, in order to strengthen the brakes on the inner drive wheels,
The inner wheel side when turning is shown by a broken line a. In this way, when turning, the load shifts to the outer wheel side and the inner wheel side becomes prone to slipping. This can sometimes prevent the inner ring from slipping.

In the above embodiment, feedback control is performed by PID control based on ΔA/H, and sub-throttle valve opening correction amount Δe2 is added and corrected to target opening θ2, and the feedback-corrected target opening θf is applied to the motor drive circuit. 52
However, even without performing feedback control using ΔA/N, the target opening degree θ2
may be outputted to the motor drive circuit 52, and the output of the throttle position sensor TPS2 may be feedback-controlled so that the opening of the sub-throttle valve THs detected by the throttle position sensor TPS2 becomes the target opening e2. Furthermore, the throttle position sensor TP
Feedback control may be performed so that the corrected detection value by subtracting the sub-throttle valve opening correction amount Δe2 from the opening of the sub-throttle valve THs detected in S2 becomes the target opening θ2.

Further, although an acceleration slip prevention device is shown as an embodiment of the present invention, the present invention is not limited to this device, and can be similarly applied to any device that controls a throttle valve.

Also, in the T/M friction correction section 502, <T/
The target engine torque T3 is calculated by the first method of M friction correction>, and the target engine torque T6 is calculated by the second method of engine operating condition correction in the operating condition correction section 505. In addition to correcting the target engine torque according to the oil temperature OT, the target engine torque can also be corrected based on the elapsed time τ after starting the engine.

Also, in the T/M friction correction section 502, <T/
The target engine torque T3 is calculated by the second method for correcting engine operating conditions in the operating condition correction section 505, and the target engine torque T6 is calculated by the second method for correcting engine operating conditions in the operating condition correction section 505. The target engine torque can be corrected in accordance with the machine state and the cooling water humidity of the engine, and can also be corrected based on the elapsed time τ after starting the engine.

Furthermore, in the T/M friction correction section 502, <T
The target engine torque T3 is calculated by the /M third method of friction correction>, and the target engine torque T6 is calculated by the second method of engine operating condition correction in the operating condition correction section 505. The target engine torque can be corrected based on the warm-up state of the coolant temperature wTo immediately after engine startup and the real-time coolant temperature WT, and the target engine torque can also be corrected based on the elapsed time τ after engine startup.

[Effects of the Invention] As described in detail above, according to the present invention, in the vehicle engine output control method for controlling the throttle opening so that the vehicle engine output becomes the target engine output, the target engine output is set to the target air amount. If there are two throttle valves in the intake path, multiplying the equivalent throttle opening by the correction coefficient will uniquely determine the opening of the other throttle valve, so if the equivalent throttle opening has changed. Therefore, it is possible to provide a vehicle engine output control method that allows the opening degree of the other throttle valve to be immediately determined even in the case where the other throttle valve is opened, thereby making it possible to realize highly accurate control.

[Brief explanation of the drawing]

FIG. 1(A) is an overall configuration diagram of an acceleration slip prevention device to which the control method according to the present invention is applied, FIG. 1(B) is a diagram showing the arrangement of the main and sub-throttle valves, and FIG. A) and (B) are block diagrams showing the control of the traction controller in Fig. 1 divided into functional blocks, Fig. 3 is a diagram showing the relationship between centripetal acceleration GY and variable KG, and Fig. 4 is a diagram showing the relationship between centripetal acceleration GY and variable KG. A diagram showing the relationship between GY and variable Kr, FIG. 5 is a diagram showing the relationship between centripetal acceleration GY and slip correction QVg, and FIG. 6 is a diagram showing the relationship between centripetal acceleration GY and slip correction Q.
7 to 12 are diagrams each showing the relationship between the vehicle speed VB and the variable Kv, and FIG. 13 is a diagram showing the change over time in the variable KB from the start of brake control.
Figure 14 shows the temporal change in slip 2 fnGFR (GPL
) and the amount of change ΔP in brake fluid pressure.
5 and 18 are diagrams showing the relationship between the slip ratio S and the friction coefficient μ of the road surface, respectively. FIG. 16 is a diagram showing the Tl1ffl- characteristic. FIG. 20 is a diagram showing the state of the vehicle during turning, FIG. 20 is a transmission oil temperature OT-torque correction amount Tr characteristic diagram, FIG. 21 is an XT-torque correction amount Tf characteristic diagram, and FIG.
The figure shows the time after startup τ - engine cooling water fAVT, transmission oil temperature OT characteristic diagram, and Fig. 23 shows the rotation speed N
- Torque correction 11Tr characteristic diagram, Fig. 24 is a map showing the torque correction ff1Tf' for engine cooling water temperature WT - intake air amount integrated value ΣQ, Fig. 25 is a diagram showing the relationship between rotational speed Ne and loss torque TL, FIG. 26 is a diagram showing the relationship between pump oil temperature OP and loss torque TL, FIG. 27 is a diagram showing the relationship between battery voltage vb and loss torque TL,
FIG. 28 is a map showing loss torque TL with respect to engine rotational speed Ne and alternator exciting current iΦ;
The figure shows alternator efficiency K with respect to excitation current iΦ, Figure 30 is an atmospheric pressure-torque correction amount Tp characteristic diagram, and Figure 31
The figure shows the engine cooling water temperature WT-) Lew correction ff1TW characteristic diagram, Figure 32 shows the elapsed time after engine start vs. torque correction ffi TaS characteristic diagram, and Figure 33 shows the engine oil temperature-
Torque correction amount Tj characteristic diagram, FIG.
FIG. 35 is a diagram showing the engine rotation speed Ne characteristic of the coefficient Ka, FIG. 36 is a diagram showing the intake air temperature characteristic of the coefficient Kt, FIG. 37 is a diagram showing the atmospheric pressure characteristic of the coefficient Kp, and FIG. 38 is a diagram showing the Nl11 map. The figure shows the intake air temperature characteristics of the coefficient Ka', and Figure 39 shows the target air ff1A/NO and the engine rotation speed N.
A map for determining the equivalent throttle opening θb for Q, FIG. 40 is a map showing the relationship between el/eb and the correction coefficient, and FIG. 41 is a map showing the relationship between the main throttle valve opening e1 and the sub throttle valve opening e2. Equal air quantity characteristic curve diagram, Figure 42 is a diagram showing engine rotation speed characteristics with proportional gain Kl), Figure 43 is a diagram showing engine rotation speed characteristics with integral gain Kl, and Figure 44 is a diagram showing engine rotation speed characteristics with differential gain Kd. FIG. 45 is a diagram showing the engine speed characteristic of conversion gain, FIG. 46 is a diagram showing the relationship between target opening θ and coefficient K s, and FIG. 47 is a diagram showing the relationship between engine cooling water 9nWT- It is a figure which shows the step number conversion value Sv. 11-14...Wheel speed sensor, 15...Traction controller, 45...TSn calculation unit, 45b. 46b... Coefficient multiplier, 46... TPn calculation unit, 4
7... Reference torque calculation section, 503... Engine torque calculation section, 507... Target air amount calculation section, 512...
- Target throttle opening calculation section, 53... Centripetal acceleration calculation section, 54... Centripetal acceleration correction section. Applicant's representative Patent attorney Takehiko Suzue (A) Fig. 1 0.19 Search acceleration (,li/ Fig. 04g 0.9g Search I acceleration Y Fig. 0.19 Search acceleration GY Figure: Vehicle speed VB Figure: Vehicle speed ylVB Figure 13: Vehicle speed VB 11 Figure I: Body speed B 12 Figure 14: Tire slip rate S Figure: 19 Figure: Vehicle speed from the start of control VB (Km/h) Transmission 9. Temperature T Figure 21 Time after starting Figure 22 Rotational speed Figure Rotational speed Ne Figure 25 Pump oil pressure P Figure 26 Figure Battery Voltage vb Fig. 29 Fig. Engine cooling water A WT Fig. Engine speed Ne Fig. 35 Fig. 35 Time elapsed after engine start Fig. 32 Engine, white star OT Intake 1 degree (AT) Fig. Atmospheric pressure (AP) Fig. 37 Fig. 38 Fig. 41 Fig. 40 Fig. 39 Fig. Engine rotation speed Ne Fig. 42 Fig. Engine rotation speed Ne Fig. 44 Fig. Engine rotation speed Ne Fig. 45

Claims (1)

[Claims] A main throttle valve whose opening degree Θ1 is controlled according to the operating amount of the accelerator pedal and a sub-throttle valve whose opening degree Θ2 is electrically controlled are provided in the intake path to the vehicle engine. By controlling the degree Θ2,
The engine output control device that controls the output of the engine includes a target engine torque calculation means that calculates a target engine torque that the engine should output, and a target per engine rotation required to generate the target engine torque. A target intake air amount calculating means for calculating an intake air amount, and an equivalent throttle opening Θh when the main and sub throttle valves are assumed to be one equivalent throttle valve from the target intake air amount per revolution of the engine. equivalent throttle valve opening calculation means and equivalent throttle opening Θh
and a correction coefficient storage means for storing a correction coefficient determined by the relationship between the opening degree Θ1 of the main throttle valve and the opening degree Θ1 of the main throttle valve; 1. A method for controlling engine output of a vehicle, comprising: a power calculation means.