JPH02291462A - Engine output control method for vehicle - Google Patents

Abstract

PURPOSE:To embody the control of high precision by changing an intake air amount for making engine output generate target engine torque depending upon cooling water or intake air temperature in determining the target degree of the opening of a throttle valve for generating engine output to meet target engine torque. CONSTITUTION:After the conversion 500 of target torque Tphi obtained in the preceding stage for a driving wheel to target engine torque T1 is made, this torque T1 is corrected in sequence with each of correction parts 501 to 505 for torque converter response delay, friction, an external load, an atmospheric condition and an operation condition. Furthermore, the calculation 507 of a target air amount A/Nv is made for outputting engine torque T7 after correction. After the correction 508 of the amount A/Nv is made with intake air temperature, the calculation 509 of a target throttle opening degree theta2' is made. On the basis of the opening degree theta2', the calculation 510 of the throttle opening degree theta2 of a sub-throttle valve is made. In this case, a target air amount correction part 508 seeks a target air amount A/No with correction made for the target air amount A/Nv obtained from a calculation part 507 with intake air temperature, thereby obtaining a target air amount A/No.

Description

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

(Prior Art) Conventionally, an acceleration slip prevention device (traction control) is used to control the engine so that the engine output reaches a predetermined target engine torque. Device)
It has been known.

In such a traction control device,
When acceleration slip of the drive wheels is detected, the slip rate S is controlled so that the coefficient of friction μ between the tires and the road surface is within the maximum range (shaded range in FIG. 18). Here, the slip rate S is [(VF - VB)/VP)
(%), VFJ, tH wheel speed of driving wheels,
VB is the vehicle speed. In other words, when a slip of the drive wheels is detected, the engine output is controlled so that the slip ratio S falls within the shaded range, and the friction coefficient μ between the tires and the road surface is controlled within the maximum range. It prevents the drive wheels from slipping during acceleration, improving the vehicle's acceleration performance.

(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.

Incidentally, engine output changes depending on the amount of intake air sent into the combustion chamber of the engine. Further, the intake air taken in from the air cleaner and sucked into the combustion chamber of the engine expands or contracts according to the gas equation of state.

Therefore, if the intake air temperature at the air cleaner is higher than the combustion chamber temperature, the volume of the intake air will decrease as it enters the combustion chamber. As described above, if there is a difference between the intake air temperature and the temperature of the engine's combustion chamber, the intake efficiency of intake air into the engine's combustion chamber changes. Therefore, if it is necessary to send intake air from a certain body box into the combustion chamber, it is necessary to correct it according to the intake air temperature.

The present invention has been made in view of the above points, and its object is to provide a throttle valve in an intake passage to a vehicle engine,
In the engine output control device that controls the output of the engine by controlling the opening degree of the throttle valve,
A vehicle engine output control method that can accurately control engine output to a target engine torque by changing the amount of intake air to adjust the engine output to the target engine torque in accordance with changes in engine cooling water temperature or intake air temperature. It is about providing.

[Structure of the Invention] (Means and effects for solving the problem) An engine output in which a throttle valve is provided in an intake passage to a vehicle engine, and the output of the engine is controlled by controlling the opening degree of the throttle valve. In the control device, a target engine torque calculation means for calculating a target engine torque to be output by the engine, and a target intake air amount calculation means for calculating a target intake air amount per engine rotation necessary to generate the target engine torque. and a throttle valve opening degree calculation means for calculating the opening degree of the throttle valve with respect to the target air amount with correction based on at least one of engine water temperature and intake air temperature. .

(Embodiment) Hereinafter, an acceleration slip prevention device for a vehicle in which a method for controlling engine output for a vehicle 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. Further, 11 is a wheel speed sensor that detects the wheel speed VFR of the front right wheel (drive wheel) WFR;
12 is the wheel speed VPL of the front left wheel (drive wheel) WFL
13 is a wheel speed sensor that detects the wheel speed VRR of the rear right wheel (driven wheel) WRR, and 14 is the wheel speed VR of the rear left wheel (driven wheel) WRL.
This is a wheel speed sensor that detects I. Wheel speed VFR, VPI detected by the wheel speed sensors 11 to 14
,, VRR, VRL are input to the traffic controller 15. This traction controller 15
Intake air temperature A detected by an intake air temperature sensor (not shown)
T, atmospheric pressure AP detected by an atmospheric pressure sensor (not shown),
Engine rotation progress N detected by a rotation sensor (not shown)
(3s Intake air ffiA/N per engine four-turn cycle detected by an air flow sensor (not shown), transmission oil temperature OT detected by an oil temperature sensor (not shown), engine cooling water temperature detected by a water temperature sensor (not shown) WT, operation status of air conditioner switch (not shown);
The operating state of the power steering switch SW (not shown), the operating state of the idle switch (A, not shown), the power steering pump oil temperature OP (not shown), the cylinder pressure CP1 of the engine cylinder detected by the cylinder pressure sensor (not shown), the combustion chamber wall temperature sensor (not shown) The combustion chamber wall temperature CT of the engine detected by , the excitation current iΦ of the alternator, and the elapsed time τ after engine startup output from a timer (not shown) that counts the time after engine startup are 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
As shown in FIG. 1(A), in addition to the main throttle valve THm whose distance e1 is operated by the accelerator pedal, there is also a sub-throttle valve THm whose distance e2 is controlled by an opening signal es, which will be described later, from the traction controller 15. It has a throttle valve THs. The opening degree θ2 of this sub-throttle valve THs is determined by the opening degree signal e from the traction controller 15.
This is done by the motor drive circuit 52 controlling the rotation of the motor 52II1 by s.

The driving force of the engine 16 is controlled by controlling the opening e2 of the sub-throttle valve THm in this manner. The opening degrees θ1 and e2 of the main throttle valve THms and the sub-throttle valve THs are detected by throttle position sensors TPSI and TP S2, respectively, and are output to the motor drive circuit 52. Further, a bypass passage 52b is provided between the upstream and downstream sides of the main and sub-throttle valves THI5 and THs to ensure an intake air amount during idling, and this bypass passage 52b
The amount of opening is controlled by a stepper motor 52s. Further, a bypass passage 52c is provided between the upstream and downstream sides of the main and auxiliary throttle valves THm and THs, and this bypass passage 52c has a Fuchs valve 52W whose temperature is adjusted according to the cooling water temperature WT of the engine 16. is provided.

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

Pressure oil is supplied from the hydraulic power 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 2o through an outlet valve 17o. Furthermore, pressure oil is supplied to the wheel cylinder 18 from the hydraulic source 19 via an inlet valve 18i, and pressure oil is discharged from the wheel cylinder 18 to the reservoir 20 via an outlet valve 180. . Opening and closing control of the inlet valves 17i and 1811 and the outlet valves 170 and 180 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 figure, reference numerals 11 and 12 are wheel speed sensors that detect the wheel speeds V FR and V PL of the drive wheels WPR and WPL, and the drive wheel speeds VFR. Both VPLs are sent to a high vehicle speed selection section 31 and an averaging section 32. The high vehicle speed selection section 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 selection section 31 is output to the weighting section 33. Further, the average part 32 includes the wheel speed sensors 11 and 12.
The average driving wheel speed CVPR+V['L)/2 is calculated from the driving wheel speeds VFR and VPL obtained from
The average driving wheel speed calculated by the averaging section 32 is output to the weighting section 34. ff! The finding unit 33 selects and outputs the drive wheels W P selected by the high vehicle speed selection unit 31 .
Multiply the wheel speed of R or WPL, whichever is higher, by KG (variable)
In addition, the weighting section 34 multiplies (variable) the average driving wheel speed output by the averaging section 32 by (1-KG), so that the driving wheel speed weighted by the weighting sections 33 and 34 is The speed and average driving wheel speed are calculated by the adding section 35
is given to and added to calculate the driving wheel speed vF.

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

On the other hand, wheel speed sensors 13, . Both of the driven wheel speeds VRR and VRL detected by the low vehicle speed selection unit 36
and is sent to the high vehicle speed selection section 37. The low vehicle speed selection section 36 selects the lower wheel speed of the driven wheel speeds VRR and VRL, and the high vehicle speed selection section 37 selects the driven wheel speed VI? I? , VRL, and the low driven wheel speed selected by the low vehicle speed selection section 36 is sent to the weighting section 38 and also to the high vehicle speed selection section 37.
The high driven wheel speed selected by is output to the weighting 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 39
Driven wheels W selected by the high vehicle speed selection section 37
RI? , WRL, whichever is higher wheel speed (1-K
r) multiplication (variable), and the driven wheel speed weighted by each of the weighting units 38 and 39 is multiplied by the adding unit 40
is added to calculate the driven wheel speed VR.

The driven wheel speed VR calculated by this addition section 40 is output to a multiplication section 40'. This multiplier 40' multiplies the calculated driven wheel speed VR by (1+α), and the driven wheel speed Vl? R, Vl?
A target drive wheel speed Vφ based on L is calculated.

Here, the variable Kr 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 drive wheel speed Vφ calculated by the multiplier 40' are given to the subtracter 41.

This subtractor 41 subtracts the target drive wheel speed Vφ from the drive wheel speed VF to calculate the slip iDVi' (VF-Vφ) of the drive wheels WPR, WFL. The quantity DVi' is given to the adder 42. This adder 42 calculates the slip amount DV i' by calculating the centripetal acceleration GY and its rate of change ΔGY.
The slip correction JaVg (see FIG. 5), which changes according to the centripetal acceleration GY, is given from the slip amount correction section 43, and is corrected according to the rate of change ΔG of the centripetal acceleration GY.
Slip correction amount Vd that changes according to Y (see Figure 6)
is given from the slip amount correction section 44. That is, in the addition section 42, the slip amount DV obtained from the subtraction section is
Each slip correction iVg, Vd is added to i', and the slip JIDVi, which is corrected in accordance with the centripetal acceleration GY and its rate of change ΔGY through this addition section 42, is calculated every 15 ms sampling time T, for example. The signal is sent to the TSn calculation section 45 and the TPn calculation section 46.

The calculation section 45a in the TSn calculation section 45 multiplies the slip ffiDVi by a coefficient Kl and calculates the integral correction torque TSn' (-ΣK!・DVi). 45b
sent to. In other words, the above integral correction torque TSn
is a correction value for the drive torque of the drive wheels WPR, WPL, and adjusts its control gain in accordance with changes in the speed change characteristics of the power transmission mechanism that exists between the drive wheels WPR, WFL and the engine 16. Therefore, the coefficient multiplier 45b multiplies the integral type correction torque TSn' obtained from the calculation unit 45a by a coefficient GKi that differs depending on the gear position to calculate the integral type correction torque TSn corresponding to the gear position. . Here, the 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 Mi D Vi by the coefficient K p, and calculates the proportional correction torque 'rpn'. is sent to the coefficient multiplier 46b. In other words, this proportional correction torque T
Pn is also a correction value for the drive torque of the drive wheels WFR, WFL, similar to the above-mentioned square type correction torque TSn', and changes the speed change characteristics of the power transmission mechanism existing between the drive wheels WPR, WFL and the engine 16. It is necessary to adjust the control gain according to the shift speed, and the coefficient multiplier 46b multiplies the proportional correction torque TSn' obtained from the calculation section 46a by a coefficient GKp that differs depending on the gear position. A proportional correction torque TPn corresponding to the stage is calculated.

On the other hand, the driven wheel speed VR obtained by the addition section 40 is sent to the reference torque calculation section 47 as the vehicle body speed VB. The reference torque calculating section 47 first calculates the acceleration CB of the vehicle speed VB in a vehicle acceleration calculating section 47a.
It is sent as P to the reference torque calculation unit 47c. This reference torque calculation unit 47c calculates a reference torque TG (-GBP) based on the vehicle body acceleration GBP, vehicle weight W, and wheel radius Re.
xWxRe), and this reference torque TG becomes the axle torque value that the engine 16 should originally output.

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 ratio 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 GBF 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).

GB Pn= (GBn+ GBBFn-4)/
2-41) Also, for example, when the acceleration of the vehicle is currently decreasing, the slip rate S is S>Sl and the 15th
In the case of shifting to the range r2J − “3” shown in the figure, in order to maintain the state of “2” as much as possible, the vehicle body acceleration GBP is changed to the previous output GBPn of the filter 47b.
The vehicle body acceleration GBPn having a value close to -1 is calculated by the following equation (2).

GBPn - (GBn+7 GBPn-1)/8
-(2) Furthermore, for example, when the acceleration of the vehicle is currently decreasing, the slip rate S is S≦81 and the 15th
In the case of transition from "2" to "1" as shown in the figure, in order to return to the state in the range "2" as much as possible, the vehicle body acceleration GB
F is a vehicle body acceleration G that has a value closer to the previously calculated vehicle body acceleration GBPn-1 than when calculated using the above equation (2), with further weight placed on the previous output GBPn-1 of the filter 47b. BPn is calculated by the following formula (3).

GBPn = (GBn+15GBFn-1)/1B
-(3) Next, the reference torque 1'G 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 TO 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 section 49 further subtracts the proportional correction torque TPn calculated by the TPn calculation section 46 from the subtraction data obtained from the subtraction section 48, and the subtraction data is used to drive the drive wheels WPR, WPL. Target torque T of the axle torque to be
engine torque converter 50 via switch S1 as φ
Sent to 0. In other words, Tφ-TO-TSn-TPn.

This engine torque conversion section 500 converts the drive wheels WPR, W given from the subtraction section 49 via the switch S1.
The target torque Tφ for PL is divided by the total gear ratio between the engine 16 and the drive wheel axle to convert it into a target engine torque Tl. This target engine torque T1 is output to the torque converter response delay correction section 501. This 1.
A control response delay correction unit 501 corrects the engine torque T1 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 a T/M (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 T6.
For example, as shown in FIGS. 16 and 17, the lower limit value T! changes depending on the elapsed time t from the start of traction control or the vehicle speed VB. 1g+ and output to the target air amount calculation unit 507 as the target engine torque T7. This target engine torque T7 is then output to the target air amount calculation section 507.

Hereinafter, in the target air amount calculation unit 507, the target air amount (mass m) required to output the engine torque T7
is calculated. Here, the meaning of putting "quality melon" in parentheses as the target air n (mass) is that the amount of intake air required to burn a certain child's fuel is based on quality 2. Further, although the expression "target air amount (volume)" is used in the following specification, this is because it is the volume, not the mass, of the intake air amount that is controlled by the throttle valve.

By the way, this target air tk calculation unit 507 calculates the target air amount (mass) A/N per engine rotation for outputting the target engine torque T7 in the engine 16.
m is calculated, and this target air fit A/
For Na, the target air amount (mass m) A/Nm is determined based on the engine rotational speed Ne and the target engine torque T7 with reference to the three-dimensional map shown in FIG.

A/Ns = r [Ne, T7] Here, A/N
I1 is the intake air amount (mass) per engine rotation, and f [Ne, T7] is a three-dimensional map using the engine rotation speed Ne and target engine torque T7 as parameters.

Further, in the target air amount calculation unit 507, the target air amount (mass) A/Nm is corrected by the intake air temperature AT and atmospheric pressure AP according to the following formula, and the target air amount (volume) A/Nv under standard atmospheric conditions. It is converted to .

A/Nv − (A/Nm)/lKt(AT) *Kp
(AP)1 Here, A/N v is the amount of intake air (volume) per engine revolution, Kt is the density correction coefficient with the intake air temperature (AT) as a parameter (see Figure 37), K
p is a density correction coefficient (see FIG. 38) using atmospheric pressure (AP) 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 mA/NO is calculated using the following formula.

A/NO - A/Nv * Ka' (AT) where A/NO is the target air amount after correction, A/Nv is the target air amount before correction, and Ka' is the correction coefficient ( (See Figure 38).

The above correction is performed for the following reasons.

In other words, the intake efficiency of air into the engine changes depending on the intake air temperature, but if the intake air temperature is lower than the engine cooling water temperature, the intake air expands when it is sent into the engine's combustion chamber, so the intake Efficiency decreases. On the other hand, when the intake air temperature AT is higher than the combustion chamber temperature CT of the engine, the intake air contracts when sent into the combustion chamber of the engine, so that the intake efficiency increases. Therefore, when the intake air temperature AT is low, taking into account that the intake air expands in the combustion chamber, the target air ffl (volume) is multiplied by a correction coefficient K a / to make a larger correction. To compensate for the decrease in control accuracy due to the decrease in efficiency, and to take into account that the intake air contracts in the combustion chamber when the intake air temperature AT is high, a correction coefficient K is added to the target air amount (volume).
A/ is multiplied and corrected to a small value to prevent a decrease in control accuracy due to an increase in suction efficiency. In other words, as shown in Fig. 38, when the intake air temperature is higher than the standard intake air temperature ATO, the correction coefficient Ka' decreases according to the intake air temperature AT, and when the intake air temperature AT is lower than the standard intake air temperature ATO. In this case, the correction coefficient Ka' is set to increase in accordance with the intake air temperature AT.

The target air amount A/NO is determined by the target throttle opening calculation unit 5.
09, the three-dimensional map shown in Fig. 39 is referred to, and the target air amount A/NO and the opening degree θl of the main throttle valve THn+ are determined.
The target throttle opening degree θ2' for the target throttle opening degree θ2' is determined. The three-dimensional map shown in FIG. 39 is obtained as follows.

In other words, when changing the main throttle valve TH+++ opening el or the opening θ2 of the sub-throttle valve THs, the amount of intake air per engine rotation is grasped as data, and the intake air amount per engine rotation is Opening degree θ of sub-throttle valve THs corresponding to intake air amount
This is a map of the relationship between the two.

The target throttle opening e2' is sent to the opening correction section 510 for the amount of bypass air. During this time, the degree correction unit 510
is the opening correction coefficient Ks per step of the stepper motor 52s using the target opening θ shown in FIG. 44 as a parameter.
is input. Furthermore, the opening correction unit 510 has a conversion value Sv ( Fig. 45) is done manually.

The opening correction section 510 calculates the amount of air passing through the bypass passages 52b and 52c from the number of driving steps of the stepper motor 52s and the cooling water temperature WT.

Then, an opening correction amount Δe corresponding to this air amount is calculated. Then, in the opening correction section 510, the opening correction amount Δe is subtracted from the target throttle opening e2' calculated by the target throttle opening calculating section 509. In this way, the target throttle opening degree θ2 of the sub-throttle valve THs is calculated.

On the other hand, the corrected target air ffiA/No output from the target air amount correction section 508 is also sent to the subtraction section 513. This subtraction unit 513 calculates the target air ffi A /
Deviation Δ between N O and the actual intake air amount A/N detected at each predetermined sampling time by the air flow sensor
This is to calculate A/N, and this target air ffiA/NO
The deviation ΔA/N between the actual air amount A/N and the actual air amount A/N is determined by the PID control unit 51.
Sent to 4. This PID control unit 507 controls the deviation Δ
Opening correction amount Δ of sub-throttle valve THs corresponding to A/N
e2 is calculated, and this sub-throttle valve opening correction amount Δe2 is sent to the adding section 515.

Here, the sub-throttle valve opening correction plate Δe2 obtained by the PID control unit 514 is the sum of an opening correction amount Δep by proportional control, an opening correction amount Δel by integral control, and an opening correction amount Δed by differential control. be.

Δθ2−Δep+Δ191−IcedΔθp4p(N
e) *Kth (Ne) *Δ^haΔθi−K1(Nc
)*Kth (Ne)*Σ(ΔA/N)Δe d−K
d(N e) * K th (N e) * lΔA/
N-ΔA/Nold) Here, each coefficient Kp, Kl, Kd
are the proportional gain (see Figure 40), the proportional gain (see Figure 41), and the differential gain (see Figure 42) with the engine rotation speed Ne as a parameter, and Kth is the proportional gain (see Figure 42) with the engine rotation speed Ne as a parameter. ΔA/N-Δe
Conversion gain (see Figure 43), ΔA/N is target air amount A
Deviation between /No and actual air amount A/N, ΔA/N
Old is ΔA/N at the previous sampling timing
It is.

The addition unit 515 adds the target throttle opening θ2 corrected by the opening correction unit 510 and the sub-throttle valve opening correction amount Δθ2 calculated by the PID control unit 514, and The degree ef is calculated. This target opening degree er is sent to the motor drive circuit 52 as a sub-throttle valve opening signal θS. This motor drive circuit 52 is connected to the throttle position sensor TPS.
The rotation of the motor 52Il 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 θS.

By the way, the wheel speeds VRR and VRL of the driven wheels are sent to the centripetal acceleration calculating section 53, and in order to judge the turning degree,
The centripetal acceleration GY' is determined. This centripetal acceleration GY'
is sent to the centripetal acceleration correction section 54, and the centripetal acceleration GY'
is corrected according to vehicle speed.

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

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. Furthermore, the higher driven wheel speed output from the high vehicle speed selection section 37 is subtracted from the driving wheel speed vFL by 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 uDVPR of the right drive wheel.

At the same time, the output of the subtraction section 56 is multiplied by KB in the multiplication section 60, and the output of the subtraction section 55 is multiplied by (1-Kn) in the multiplication section 61, and then added in the addition section 62, and the output of the subtraction section 56 is multiplied by KB in the multiplication section 60. It is assumed to be a slip ffiDVPL.

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

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 Pl of the left drive wheel. is differentiated by the differentiator 64 to calculate the amount of change over time, that is, the slip acceleration GFL. Then, the slip acceleration GPR is sent to the brake fluid pressure change amount (ΔP) calculation unit 65, and the GFR (GFL) - ΔP conversion map shown in FIG. The amount of change in pressure ΔP is determined. This amount of change in brake fluid pressure ΔP
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, and the first
The opening time T of the inlet valve 171 and the outlet valve 17o in FIG. 3(A) is calculated. Similarly, the slip acceleration CI'L is the brake fluid pressure change amount (Δ
P) GPR sent to the calculation unit 66 and shown in FIG.
The (GPL)-ΔP conversion map is referred to to determine the amount of change ΔP in brake fluid pressure for suppressing slip acceleration GPL. The amount of change ΔP in brake fluid pressure is sent to the ΔP-T conversion unit 68 via the switch S3, which is controlled to open and close by the start/end determining unit 50, as shown in FIG.
The opening time T of the inlet valve 18i and the outlet valve 18o in A) is calculated. Then, the inlet valve 171.18+ calculated as above
And the outlet valve 170.18o is controlled to open for the opening time T, and the right drive wheel WFI? And the brake is applied to the left drive wheel WPL.

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 amount DV calculated by the subtraction section 41
I' is sent to the differentiator 41a and slips iiiD
A temporal change rate ΔDVi' of Vi' is calculated. The above slip mDVi' Its temporal change rate ΔDV!
', the opening degree θ2 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. The start/end determination unit 50 closes the switches Sl-S3 to control the slip 'mDvI' and the engine torque Te when the temporal change rate ΔDV1' and the engine torque Te both exceed their respective reference values. is started, and when the opening degree θ2 of the sub throttle valve THs becomes larger than a predetermined reference value or DVi' becomes smaller than a predetermined reference value (different from the above reference value), the switch St
-33 is opened and control is terminated.

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 FIGS. 1 and 2, wheel speed sensors 13, 1
The wheel speed of the driven wheel (rear wheel) output from 4 is input to the high vehicle speed selection section 36, the low vehicle speed selection section 37, and 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
6 and the high city speed selection section 37, the same wheel speed is selected. 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'-v/r ・
...It is calculated as (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 Mo, and the turning center M
The distance from o to the inner wheel side (W 171?) is 1, the tread is Δr, the wheel speed of the inner wheel side (W RR) is vl, and the wheel speed of the outer wheel side (W RL) is v2.
In this case, v2/vl-(Δr+r1)/rl-
(5).

Then, by transforming the above equation (5), 1/ rl = (v2-vl)/Δr ・v l
- (6). Then, taking the inner ring side as the basis, the centripetal acceleration GY' is GY' -vl /rl -vl (v2-vl)/Δ'・v1-vl ・(
v2-vl)/Δr-(7).

That is, the centripetal acceleration GY' is calculated by the above equation (7). By the way, since the wheel speed vl on the inner wheel side is smaller than the wheel speed v2 on the outer wheel side during a turn, the centripetal acceleration GY' is calculated using the wheel speed vl on the inner wheel side.
The centripetal acceleration GY' is calculated to be smaller than the actual one. Therefore, the coefficient KG multiplied by 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 ■F is estimated to be small,
The slip amount DV' (vp-yΦ) 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 as ``l'', 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 sent to the centripetal acceleration correction section 54, and the coefficient Kv in FIG. 7 is added to the centripetal acceleration GY' so that the centripetal acceleration GY becomes small at high speeds. Multiplied.

This variable Kv is set to decrease according to the vehicle speed, and may be set as shown in FIG. 8 or 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 the above-mentioned understeer 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 a variable Kr in the weighting section 38 as shown in FIG. In the variable ( 1 −
K r ) is multiplied. The variable Kr is set to "1" when turning when the centripetal acceleration GY becomes larger than, for example, 069g, and when the centripetal acceleration GY becomes O, . When it becomes smaller than 4g, it is set to rOJ.

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 wheel speeds outputted from the weighting sections 38 and 39 are added together in an adding section 40 to obtain the driven wheel speed V.
I? Further, the driven wheel speed VR is calculated by the multiplier 40'
is multiplied by (1+α) to obtain the target driving wheel speed VΦ.

Further, after the higher wheel speed of the driving wheels is selected in the high vehicle speed selection section 31, the weighting section 33
In this case, the variable KG is multiplied as shown in FIG. Furthermore, the average vehicle speed (V
r'R+VPL) /2 is determined by the weighting unit 34 as (
1-KG) and added to the output of the weighting section 33 and the adding section 35 to obtain the driving wheel speed vF. Therefore, when the centripetal acceleration GY becomes, for example, 0.1 g or more, K
G −1, the wheel speed of the larger drive wheel of the two drive wheels output from the high vehicle speed selection unit 31 is output. In other words, when the turning angle of the vehicle becomes large and the centripetal acceleration GY becomes, for example, 0.9 g or more, rKG - Kr - IJ is obtained, so the driving wheel side changes the wheel speed of the outer wheel side, which has a higher wheel speed, to the driving wheel side. The speed ■F is assumed to be F, and since the driven wheel speed VR is the wheel speed of the inner wheel having a lower wheel speed, the slip amount DVi' (mVP-VΦ) calculated by the subtraction unit 41 is estimated to be large. Therefore, since the target torque TΦ is expected to be small, the engine output is reduced, the slip ratio S is reduced, and the purchasing power A can be increased as shown in FIG. It is possible to increase the grip force of the vehicle and perform safe turns.

To the slip amount DVi, the slip amount correction section 43 adds a slip correction amount vg as shown in FIG. A slip QVd is added.

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 subjected to the slip correction ff shown in FIG.
iVg(〉O) and slip correction iVd(
>0) is added to give the slip -31DVi, and in the latter half of the curve, the slip correction 1; kVg (>0) and the slip correction mVd (<0) are added to give the slip mDVi. Therefore, by estimating the slip QDVi in the second half of the turn to be smaller than the slip QDVi in the first half of the turn, the engine output is reduced and the lateral force is increased in the first half of the turn, and the engine output in the second half of the turn is lower than that in the first half. The system aims to restore the vehicle's acceleration and improve the vehicle's acceleration.

In this way, the corrected slip iDVi is sent to the TSn calculation unit 45 with a sampling time T of 15 ms, for example. In this TSn calculation section 45, slip i
DVi is multiplied by a coefficient Kl and integrated to obtain a correction torque TSn.

That is, the correction torque obtained by correcting the slip iDVi, that is, the integral type correction torque TSn is obtained as TSn=GKi ΣKI−DVi (Kl is a coefficient that changes depending on the slip m D VI ).

Further, the slip uDV1 is sent to the TPn calculating section 46 every sampling time T, and the correction torque TPn is calculated. In other words, the correction torque corrected by the slip IaDVI as TPn - GKp DVI ・Kp (Kp is a coefficient),
In other words, the proportional correction torque TPn is obtained.

Further, the coefficient multiplication section 45b. The value of the coefficient GK1.0Kp used in the calculation in 46b is switched to a value corresponding to the gear position after the gear change after a set time from the start of the gear change when upshifting. This is because it takes time from the start of the shift to when the gear is actually changed and the shift is completed, and when the above-mentioned coefficients GK1 and GKp corresponding to the high speed after the shift are used at the time of the shift up, the above-mentioned correction torque TSn
．． Since the value of TPn corresponds to the above-mentioned high speed gear, it becomes smaller than the value 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 failure. This is to ensure stability.

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 (CB) of the vehicle body speed. Then, the acceleration CB of the vehicle body speed calculated in the vehicle body acceleration calculating section 47a is processed by the filter 47b using the formulas (1) to (3).
) is applied to keep GI3P at an optimal position depending on the state of acceleration GB.

For example, if the acceleration of the vehicle is currently increasing and its slip ratio S is in the state shown in the range "-1" in FIG. ), the vehicle body acceleration GBF is calculated by combining GBFn-1, which is the output of the previous filter 47b, and GBF detected this time.
The latest vehicle acceleration GB is calculated by averaging the values with the same weighting as
It is calculated as Fn.

Further, for example, when the acceleration of the vehicle is currently decreasing, the slip rate S is S>Sl, and the range 4 r2J shown in FIG.
- In the case of transition to r3J, in order to maintain the state in range "2" as much as possible, the vehicle body acceleration GBP is
As shown in equation (2) above, the previous output of the filter 47b is weighted and calculated as the previous vehicle body acceleration GBPn.

Furthermore, for example, when the acceleration of the vehicle is currently decreasing, the slip rate S is within the range r2J shown in FIG. 15 when S≦81.
- In a case where the transition to rlJ occurs, in order to return to the state in the range "2" as much as possible, the vehicle body acceleration GBP is determined by placing a large weight on the output of the previous filter 47b, as shown in equation (3) above. Vehicle acceleration G BPn
It is calculated as

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

Then, the base torque TG and the integral correction torque T
Subtraction with S n is performed in a subtraction section 48 , and the proportional correction torque TPn is further subtracted in a subtraction section 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 the 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 Tl. This target engine torque Tl 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 T/M and corrects the target engine torque T3 using the first to fourth methods described below.

<First method of T/M friction correction> This first method detects the T/M oil temperature OT using an oil temperature sensor, and if this oil temperature OT is small, the friction is large, so the second method is
The torque correction amount Tf is added to the target engine torque T2 with reference to the map shown in FIG. In other words, T3 -72 +Tf(OT). In this way, since the torque correction m T r by friction is determined according to the oil UOT of the T/M, it is possible to correct the target engine torque with high accuracy with respect to the friction of the T/M.

<Second method of T/M frixigin correction> Engine 16
The sensor measures the cooling water temperature WT of ΔIIIL, from which the T/M warm-up state (ura temperature) is estimated and the torque is corrected. In other words, T3 - T2 + TI' (WT). Here, the torque correction ffiTr(WT) is determined by referring to a map (not shown) and calculating the engine cooling water temperature WT.
It is estimated that the lower the T/M oil temperature OT is, the larger the torque correction amount Tr is set. In this way, since the T/M friction is estimated from the engine cooling water temperature WT, the T/M oil? T/M friction can be corrected without using a sensor that detects the uOT.

<Third method of T/M friction correction> Engine 16
The map in FIG. 21 is referred to based on the coolant temperature WTO immediately after the start of the engine and the real-time coolant temperature VT, and the torque correction 2 Tr is added to the target engine torque T2 to obtain the target engine torque T3. That is, T3 -72 +Tf (XT) XT- w'r+K O1: (WT - wrQ
). Here, xT is the estimated oil temperature of T/M, and KO is the ratio of the temperature increase rate of the engine cooling water temperature WT to the temperature increase rate of T/M oil. This estimated oil temperature XT,
Engine cooling water temperature WT, T/M oil? The relationship between HOT and the elapsed time after starting the engine is shown in FIG. As shown in Fig. 22, the estimated time X as the starting time elapses
The change in T is approximately equal to the change in oil temperature OT over the same starting time. Therefore, even without using an oil temperature sensor, the oil temperature is accurately monitored, the T/M friction is estimated, and the target engine torque is corrected accordingly.

<Fourth method of T/M friction correction> Engine 16
cooling water temperature WT, elapsed time τ after engine start, vehicle speed Vc
Based on T3-72+T f(WT)$11-Kas(r)*
It is calculated as Kspced(Vc)1. Here, K
as is the tailing coefficient due to the time after startup (τ) (a coefficient that gradually approaches 0 as time passes after startup), Kspe
ed indicates a tailing coefficient depending on the vehicle speed (a coefficient that gradually approaches 0 as the vehicle speed increases). 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 approaches "0". Therefore, if a sufficient amount of time has passed since the engine was started, or if the vehicle speed has increased, the torque correction Tl' due to T/M friction is eliminated.

In this way, the warm-up state of the transmission is estimated from the engine coolant temperature, the elapsed time after starting, and the vehicle speed, so the warm-up state can be estimated based on the warm-up state of the transmission, without having to directly detect the warm-up state from the transmission. If the transmission friction changes,
Since the target engine torque T2 is corrected to increase by the torque Tf corresponding to the friction, the engine torque can be controlled with high precision.

<Fifth method of T/M friction correction> The output is corrected based on the rotational speed N of the engine or T/M. Torque correction mTr is calculated based on N. In other words, T3 -72 +Tl' (N). This is because as the rotational speed N of the engine or T/M increases, the friction loss increases.

In addition, by multiplying the torque correction 1nTf (N) based on the rotational speed N of the engine or T/M by the correction coefficient Kt (OT) based on the oil temperature OT of the T/M, the target engine torque T3 is calculated as shown in the formula below. may be calculated. In other words, T3 -72 +TI' (N) * Kt (O
As T), by changing the torque correction amount Tr depending on the oil temperature OT in addition to the rotational speed N, it is possible to set the target engine torque T3 with higher accuracy.

In this way, the transmission friction is estimated according to the rotational speed of the transmission or engine, so even if the rotational speed of the transmission or engine changes and the transmission friction changes, the target engine torque T
2, by increasing the torque TI' corresponding to the above-mentioned friction and setting it as the target engine torque T3,
Even if the friction of the transmission changes depending on the rotational speed of the transmission, the engine output can be accurately controlled to the target engine torque.

<Sixth T/M friction correction method> This method estimates the warm-up state of the transmission from the cooling water temperature νT of the engine 16 and the integrated value of intake air mQ per unit time after engine startup, and calculates the correction torque. This is the way to get it.

T3 -72 +Tf(WT)*l*'i1-Σ(Kq
*Target engine torque T3 is obtained as Q)1. Here, K9 is a coefficient that converts the amount of intake air into torque loss, and in the idling state when the clutch is off or the idle SW is on, K9 (+-K
QI, otherwise Kq-K qO'( >
K ql).

In the above formula, the intake air amount Q per unit time after the engine starts is multiplied by the coefficient Kq and integrated to obtain Σ( K q
*Q) and torque correction m T W (νT) based on {1-Σ(Kq*Q)l and engine cooling water temperature WT
The product multiplied by the above 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 mQ per unit time increases rapidly, that is, even if the engine coolant temperature WT is low, the transmission is sufficiently warmed up and the T/ In cases where M friction correction is not necessary, the {...} term is immediately set to "0" to eliminate unnecessary torque correction. In addition, since Kq is set to a small value during idling, the transmission is not sufficiently warmed up even if the idling continues, so the integration of intake air ffiQ per unit time is made as much as possible than it actually is. The torque correction amount Tr based on the engine cooling water temperature is estimated to be smaller. In this way, even if the idling state continues, the above Tr (WT) term remains,
T/M friction correction is being performed. Note that the integrated intake air amount Q per unit time is calculated based on the intake air 1aA/N per engine cycle.

Further, the T/M friction torque TI' may be calculated using a three-dimensional map shown in FIG. 24.

In this case, the target engine torque T3 is expressed as shown below. In other words, T3 −72 +Tr (WT.Σ
Qa) By the way, in FIG. 24, Tf is set to be "0" when ΣQa exceeds a certain value. This is T when the total amount of intake air exceeds a certain value.
This is because it is determined that the /M oil has been sufficiently warmed so that the T/M friction can be ignored.

In this way, the warm-up state of the T/M is estimated based on the engine cooling water temperature and the integrated value of the intake air amount after engine startup, and the torque correction amount is adjusted according to the estimated warm-up state of the T/M. Since Tr is changed, the engine output can be accurately controlled to the target engine torque without directly detecting the warm-up state from the transmission.

Furthermore, since the integrated intake air amount is underestimated during idling, it is possible to accurately grasp the phenomenon in which the T/M does not reach the warm-up state even if the idling continues.

That is, when the vehicle continues to be idling, the torque correction m T f' is estimated to be larger than when the vehicle is not idling.

<Seventh method of T/M friction correction> Torque correction ffiTf' is determined based on the cooling water MWT of the engine 16 or the oil temperature of the engine 16 and the travel distance ΣVs after starting the engine. In other words, T3 −72 +Tf
(WT)*l1−Σ(K v*V s)1 where, K
V is a coefficient that converts the traveling distance (-ΣVs) into output correction, and is set to Kv - Kvl in the idling state where the idle SW is on or the clutch is off, and is set to Kv - Kv2 otherwise.
( > K vl).

In the above formula, the traveling distance ΣVs after engine startup is multiplied by the correction coefficient Kv to obtain Σ(Kv*VS), and the torque correction based on {1-Σ(KvlVs ) ) and the engine cooling water temperature WT is calculated. The product multiplied by the amount Tf(WT) is added to the target engine torque T2. By doing this, when the vehicle travels after the engine is started and its travel distance increases, the {...} term approaches "0", thereby eliminating unnecessary torque correction.

Furthermore, in the idling state, the load on the transmission is small, so the oil temperature in the transmission increases moderately. Therefore, torque losses in the transmission only gradually decrease.

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

In this way, even if the warm-up state of the transmission is not detected directly from the transmission using a transmission oil temperature sensor or the like, the warm-up state of the transmission can be estimated based on the engine cooling water temperature and the distance traveled after the engine is started.
Since the torque correction amount T' is changed according to the estimated warm-up state of the transmission, the engine output can be accurately controlled to the target engine torque. Furthermore, since the mileage is not accumulated during the idling state, it is possible to accurately grasp the phenomenon in which the transmission does not reach the warm-up state even if the idling state continues.

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 proverb 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, a loss torque TI 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. ing.

Also, focusing on the fact that the magnitude of the air conditioner load changes according to the engine rotation speed Ne, the loss torque T1 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 (Nc) 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.

In addition, 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. 26, and the target engine The torque T4 may also be calculated. That is, T4 −
73 +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 electrical load is estimated.

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

T4 -73 +TL (Vb) Here, the loss torque TL (Vb) has a relationship with the battery voltage vb as shown in FIG. That is, when the battery voltage Vb is low, it is estimated that the electrical load is large, so the loss torque TL 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. That is, T4 −73 +TI, (
iΦ). Here, the loss torque T L is the second
It is determined by referring to the map in Figure 8.

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

T4 −T3 +TL (iΦ)xK(Ne)
In the above two equations, the torque correction amount is determined by detecting the alternator excitation current iΦ, but the alternator generated current (charging current) is used instead of the alternator excitation current iΦ.
You may also use

In this way, the engine output can be accurately controlled to the target engine torque even when the load on the engine such as headlights and electric fans fluctuates and the amount of power generated by the alternator goes up and down, causing the engine output to fluctuate.

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 the target engine torque T5. In other words, T5 −T4 +Tp (A
P) 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 amount Tp is reduced accordingly.

In this way, the engine output can be accurately controlled to the target engine torque under any atmospheric conditions.

In this way, the stray 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 The torque is assumed to be TI3. 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 ffiTν is The target engine torque T5 is added to the target engine torque T6. In other words, T8 - T5 +TV (vf). As shown in FIG. 31, the lower the cooling water temperature WT is, the less the engine 16 is warmed up, so the torque correction m T W is increased.

In addition, the above torque correction Q T W is calculated by changing the engine cooling water temperature v
A map (not shown) may be created using T and the engine rotational speed Ne. That is, T6 −T5 +TV
(WT, Ne).

In this way, the warm-up state of the engine is estimated based on the engine cooling water temperature, so the warm-up state of the engine can be accurately grasped, and the target engine torque can be corrected according to the warm-up state of the engine. Therefore, the engine output can be controlled to the target engine torque in any warm-up state of the engine.

Second method for correcting engine operating conditions This second method is to add a torque correction iiTas(τ) according to the time τ after engine start as shown in FIG. 32 to the target engine torque T5. Therefore, the target engine torque T6
I am getting . In other words, TO −T5 +Tas(r). In this way, the warm-up state of the engine is estimated based on the elapsed time τ after engine startup.

In addition, the torque correction f is determined by a three-dimensional map (not shown) determined by the time after engine start τ and the cooling water mWT.
It is also possible to obtain fiTas. In other words, it may be TB −75 +Tas(r, νT). By using such a map, the cooling water temperature νTO at the time of startup is measured, and the torque correction amount Tas is determined according to the elapsed time τ, and the cooling water temperature WT at the elapsed time τ is measured to perform torque correction. i1tT
Alternatively, as may be determined.

Also, torque correction f? according to engine cooling water temperature νT? T
Torque correction is obtained by multiplying V (νT) and elapsed time τ after engine start by the parameter correction coefficient Kas(τ), and this is added to target engine torque T5 to obtain target engine torque T6. Also good.

In other words, T6 -75 +TV (wT) * Kas (
r) may also be used.

Here, T V (WT) is a torque correction amount according to the engine coolant temperature WT, and Kas (τ) is a correction coefficient according to the elapsed time τ after engine startup.

In this way, fluctuations in engine output are estimated by estimating the warm-up state of the engine based on the engine cooling water temperature and the elapsed time after engine startup, and the target engine torque is corrected. The engine output can be controlled to the target engine torque in any warm-up state.

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 in FIG. 33. In other words, it is calculated as T6 snow T5 + Tj (OT). In this way, the engine cooling water temperature VT 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 using a three-dimensional map of the engine oil temperature OT and engine rotational speed Nc (not shown). In other words, TO −75 +Tj
(OT, Ne) may also be used.

In this way, the warm-up state of the engine is detected by detecting the temperature of the engine oil, which increases in temperature as the engine rotates, and the target engine torque is corrected. The engine output can be controlled to the target engine torque under any conditions.

Fourth method for correcting engine operating conditions This fourth method is based on the engine cooling water temperature WT. Oil temperature OT, elapsed time after startup τ, combustion chamber wall temperature CT, intake air amount Q. The target engine torque T6 is determined by correcting the target engine torque T5 using a portion of the cylinder pressure CP. In other words, TO −T5 +Tc (CT/CTO)*
Kcp (cp/cpo) * l1 - Kq * Σ
(Q)).

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

In this way, the warm-up state of the engine is detected based on the combustion chamber wall temperature, the integrated value of the intake air amount after engine startup, and the cylinder pressure, and the target engine torque is corrected. The engine output can be controlled to the target engine torque under any conditions.

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 being too low and causing an engine stall.

Then, the target engine torque T7 outputted from the lower limit value setting section 506 is sent to the standard air amount calculation section 507 to calculate the target air amount (mass) A/Nm for outputting the target engine torque T7. be done.

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/N ta is the amount of intake air (mass) per intake stroke, f [Ne. 77] is a three-dimensional map with engine rotational speed N(3 and target engine torque T7 as parameters).

Note that A/NI1 is the third
It is also possible to multiply the coefficient Ka by the drift engine torque T7 as shown in FIG. 5, 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 (quality n) A/Nm is corrected based on the intake air temperature and atmospheric pressure, and the intake air Q (volume) A/N under standard atmospheric conditions is corrected.
It is converted to v.

In other words, A/Nv = (A/Nm)/(Kt(AT) * I
(p(AT)1. Here, A / N v is the intake air amount (volume) per engine revolution, and K is the density with the intake air temperature (AT) as a parameter, as shown in Figure 37. The correction coefficient Kp indicates a density correction coefficient using atmospheric pressure (8T) as a parameter, as shown in FIG.

Target intake air amount A/Nv calculated in this way
(Volume) is corrected by the intake air temperature in the target air correction unit 508, and is set to the target air m A /NO.

In other words, A/NO −A/Nv * Ka' (
AT).

Here, A/NO is the target air amount after correction, A/N
v is the target air volume before correction, Ka' is the intake air temperature (AT)
The correction coefficient (Fig. 38) is as follows.

In this way, by correcting the target air amount A/Nv (volume) by the intake air temperature (AT) and setting it as the target air amount A/NO, the intake air temperature (AT) changes and the intake air into the combustion chamber of the engine changes. Even if the efficiency changes, the target air iA/N0 can be sent to the combustion chamber with high precision, and the target engine output can be achieved with high precision.

Thereafter, the target air faA/NO output from the target air amount correction section 508 is sent to the target throttle opening calculation section 509, and the three-dimensional map shown in FIG. The opening degree θ2' of the sub-throttle valve THs with respect to the air m A /N O is determined. The opening degree e2' of the sub-throttle valve THs is sent to the opening degree correcting section 510, and the opening degree e2' of the sub-throttle valve THs is sent to the opening degree correction section 510, and the bypass passage 5 shown in FIG.
The opening degree Δe corresponding to the amount of air passing through 2b and 52C is subtracted to obtain the opening degree e2 of the sub-throttle valve THs.

By the way, the above-mentioned Δθ is obtained by the following formula.

In other words, Δe=Ks (θ) * (Sa +Sw (WT
)) Here, the coefficient Ks (Fig. 44) is the target opening degree θ
is the opening correction amount per step of the step motor 52s controlled by an ISC (idle speed controller) not shown with parameters, SII1 is the number of steps of the step motor 52s, and SW (Fig. 45) is the engine cooling This is a conversion value for converting the opening degree of the wax valve 52W with the water temperature wT as a parameter into the number of steps of the step motor 52S.

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 is calculated from the current air m A/N detected by the air flow sensor at every predetermined sampling time. A difference ΔA/N is calculated. This ΔA/N is sent to the PID control unit 514, PID control is performed based on ΔA/N, and an opening degree correction amount Δe2 corresponding to ΔA/N is calculated. This time correction amount Δe2 is added to the target throttle opening e2 in an adding section 51 to calculate a feedback-corrected target opening ef at every predetermined sampling time.

θ′−e2+Δθ2. Here, the opening correction amount Δθ is the opening correction amount Δep1 by proportional control, and the opening correction amount Δel by integral control.
This is the addition of the opening degree correction amount Δθd based on 1-differential control. In other words, Δe−Δep +Δei +Δed.

Here, Δθp=Kp(Ne)* Kth (Ne)*Δ^haΔ
θl−Ki(Ne)* Kth (Ne)* Σ (Δ
A/N) Δθd−Kd(Ne)* KLh (Ne)H
The PID control unit 51 as ΔAharΔA/Noldl
Calculated in 4. Here, Kp, Kl, and Kd are proportional, integral, and
This is a differential gain, and its characteristic diagrams are shown in FIGS. 40 to 42. In addition, Kth is the ΔA/N-Δθ conversion gain with the engine speed Ne as a parameter (Fig. 43)
, ΔA/N is the deviation between the target air amount A/No and the measured current air amount A/N, and ΔA/N Old is ΔA/N at the previous sampling timing.

The target opening ef determined as described above is sent to the motor drive circuit 52 as the sub-throttle valve opening signal θS. This motor drive circuit 52 controls the rotation of the motor 52a+ so that the opening degree θ2 of the sub-throttle valve THs detected by the sensor TPS2 corresponds to the opening degree 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 VPL in a subtraction section 56.

Therefore, the outputs of the subtraction units 55 and 56 are estimated to be small to reduce the number of times the brake is used even during turning, and the slip of the driving wheels is reduced by reducing the engine torque.

The output of the subtraction section 55 is multiplied by KB (
0<KB<1), and the output of the subtracter 56 is multiplied by (1-KB) in the multiplier 58, and then added in the adder 59 to obtain the slip mDVPI? of the right drive wheel. It is said that At the same time, the output of the subtraction section 56 is
The output of the subtraction unit 55 is multiplied by (1-KB) in a multiplication unit 61, and then added in an addition unit 62 to calculate the slip m of the left driving wheel.
It is considered FL. 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, rO. 5 J, and as the traction control progresses, rO. It is set to approach 8 J. In other words, when reducing the slip of the driving wheels by braking, it is possible to apply the brakes to both wheels at the same time when braking is started, thereby reducing the unpleasant steering shock that occurs when braking is started on a split road, for example. . On the other hand, the brake control is continued and the KB is set to rO. The operation when 8 J is reached 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, when only one drive wheel is braked and rotation decreases, the opposite drive wheel will slip due to the action of the differential and the brakes will be applied.
This is because this operation is repeated, which is not desirable. The slip fi D V PR of the right drive wheel is the differential section 63
The amount of change over time, that is, the slip acceleration GPI? At the same time, the slip amount DVPL of the left drive wheel is differentiated in a differentiator 64 to calculate its temporal change amount, that is, the slip acceleration GFL. The slip acceleration GPR is then sent to the brake fluid pressure change amount (ΔP) calculation unit 65, and the G PR (G PL) - ΔP conversion map shown in FIG. The amount of change ΔP in brake fluid pressure is determined.

Further, the amount of change ΔP is determined by the ΔP-T conversion unit 67 which calculates the opening time T of the inlet valve 171 and the outlet valve 17o when the switch S2 is opened, that is, when the start/end determination unit 50 determines that the control start condition is satisfied. given to. 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 GPL
is sent to the brake fluid pressure change amount (ΔP) calculation unit 66,
With reference to the GPR (GPL)-ΔP conversion map shown in FIG. 14, the amount of change ΔP in brake fluid pressure for suppressing slip acceleration GFL is determined.

This amount of change ΔP is the same as when the switch S3 is closed, that is, when the start/
It is given to the ΔP-T conversion unit 68 which calculates the opening time T of the inlet valve 181 and the outlet valve 18o when the end determination unit 50 determines whether the control start condition is established. That is, the valve opening time T calculated by the ΔP-T converter 68 is set as the brake operation time FL of the left drive wheel WPL. As a result, the left and right drive wheels WPR. WPL suppresses the occurrence of more slips.

In addition, in Fig. 14, when applying the brakes when turning, in order to strengthen the brake on the drive width of the inner wheel,
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, causing the inner wheel to slip, by making the amount of change ΔP in brake fluid pressure larger on the inner wheel than on the outer wheel. This can prevent the inner wheel from slipping when turning.

In addition, in the above embodiment, ΔA/N l. :Based on PID control, feedback control is performed to add and correct the sub-throttle valve opening correction amount Δe2 to the target opening e2, and the feedback-corrected target opening θ' is output to the motor drive circuit 52. Such ΔA/
Even if feedback control by N is not performed, the target opening θ2 is output to the motor drive circuit 52, and the throttle is adjusted so that the opening of the sub-throttle valve THs detected by the throttle position sensor TPS2 becomes the target opening θ2. The output of the position sensor TPS2 may be feedback-controlled. Further, feedback 1 and recontrol are performed so that the detected value corrected by subtracting the sub-throttle valve opening correction amount Δθ2 from the opening of the sub-throttle valve THs detected by the throttle position sensor TPS2 becomes the target opening θ2. You can do it like this.

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 driving condition correction in the operating condition correction section 505, thereby adjusting the T/M. In addition to correcting the 1:J target engine torque by ha according to the real-time oil temperature OT, the target engine torque can also be corrected based on the elapsed time τ after engine startup.

Also, in the T/M friction correction section 502, <T/
T/ The target engine torque can be corrected according to the warm-up state of the engine M according to the engine cooling water temperature WT, and the target engine torque can also be corrected according to the redundancy 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 third 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. The target engine torque can be corrected based on the warm-up state of the engine M based on the coolant temperature WTO immediately after the engine starts and the real-time coolant temperature vT, and the target engine torque can also be corrected based on the elapsed time τ after the engine starts.

By estimating the engine friction and transmission friction separately and correcting the target engine torque as in the three cases mentioned above, you can use the same engine with different transmissions, or the same transmission with different engines. However, it has the effect of eliminating the need for rematching.

Further, in the above embodiment, the target air amount correction unit 508 corrects the target air amount with respect to the intake air temperature, but the target air amount correction unit 508 is not provided and the opening degree correction unit 510 The target throttle opening degree θ2' may be corrected in response to a change in the intake air temperature.

[Effects of the Invention] As detailed above, according to the present invention, a throttle valve is provided in the intake passage to a vehicle engine, and the output of the engine is controlled by controlling the opening degree of the throttle valve. In the output control device, the target opening of the throttle valve is set to change the amount of intake air to adjust the engine output to the target engine torque according to changes in the engine cooling water temperature or intake air temperature, so the engine output can be adjusted with precision. It is possible to provide a method for controlling the engine output of a vehicle that can control the engine output to a target engine torque.

[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. FIG. 5 is 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 mVg, and FIG. 6 is a diagram showing the relationship between the temporal change amount ΔGY of centripetal acceleration and slip correction amount Vd. Figures 7 to 12 are diagrams showing the relationship between vehicle speed VB and variable Kv, Figure 13 is a diagram showing changes over time in variable KB from the start of brake control, and Figure 14 is a diagram showing the relationship between vehicle speed VB and variable Kv. Temporal change amount G PI? (
Figures 15 and 18 are diagrams showing the relationship between the slip ratio S and the coefficient of friction μ of the road surface, respectively, and Figure 16 is a diagram showing the relationship between the brake fluid pressure change amount ΔP and the change amount ΔP in brake fluid pressure.
FIG. 17 is a diagram showing the Ilt characteristic, FIG. 17 is a diagram showing the Tlim-VB characteristic, FIG. 19 is a diagram showing the state of the vehicle during turning, and FIG. 20 is a diagram showing the transition oil temperature OT - torque correction amount T.
['Characteristic diagram, Figure 21 is the XT-1 torque capture amount Tf characteristic diagram, Figure 22 is the time after start τ - engine cooling water temperature WT,
}Transmission oil temperature OT characteristic diagram, Figure 23 is the rotational speed N-}Lux correction amount Tf characteristic diagram, and Figure 24 is a three-dimensional diagram showing the engine cooling water temperature wT - torque correction flT for the integrated intake air amount ΣQ. Map, 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 bomb oil temperature OP and loss torque TL, and FIG.
Fig. 7 is a diagram showing the relationship between battery voltage vb and loss torque TL, Fig. 28 is a three-dimensional map showing loss torque TL with respect to engine rotational speed Ne and alternator exciting current iΦ, and Fig. 29 is a diagram showing the relationship between exciting current iΦ A diagram showing alternator efficiency K, Figure 30 is atmospheric pressure - torque correction 'Hk
T p characteristic diagram, Fig. 31 is an engine cooling water temperature WT - torque correction amount TV characteristic diagram, Fig. 32 is a characteristic diagram of elapsed time after engine start τ - torque correction QTas, and Fig. 33 is an engine oil temperature - torque correction amount characteristic diagram. Tj characteristic diagram, FIG. 34 is a three-dimensional map showing the intake air amount A/NII (mass) per engine rotation with respect to target engine torque T7 - engine rotation speed Ne, and FIG. 35 is the engine rotation speed Ne of coefficient Ka Characteristic diagrams, Figure 36 is a diagram showing the intake air temperature characteristics of the coefficient KL, Figure 37 is a diagram showing the atmospheric pressure characteristics of the coefficient Kp, Figure 3
Fig. 8 is a diagram showing the intake air temperature characteristics of the coefficient Ka', Fig. 39 is a three-dimensional map showing the opening 82' of the sub throttle valve THs with respect to the target air amount A/No and the lifetime throttle valve opening θl, and Fig. 40 is a diagram showing the opening 82' of the sub throttle valve THs. FIG. 41 is a diagram showing the engine rotation speed characteristic of the integral gain K1, FIG. 42 is a diagram showing the engine rotation speed characteristic of the differential gain Kd, and FIG. 43 is a diagram showing the engine rotation speed characteristic of the differential gain Kd. FIG. 44 is a diagram showing the relationship between the gain and the engine rotation speed, FIG. 44 is a diagram showing the relationship between the target opening degree e and the coefficient Ks, and FIG. 45 is a diagram showing the engine cooling water temperature WT-step number conversion value Sv characteristic diagram. 11-14...Wheel speed sensor, 15...Traction controller, 45...TSn calculation unit, 45b,
46b...Coefficient multiplier, 46...T'Pn calculation unit,
47... 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.

Claims (1)

[Claims] A throttle valve is installed in the intake passage to the vehicle engine,
In the engine output control device that controls the output of the engine by controlling the opening degree of the throttle valve,
a target engine torque calculation means for calculating a target engine torque that the engine should output; a target intake air amount calculation means for calculating a target intake air amount per engine rotation necessary to generate the target engine torque; 1. A method for controlling engine output for a vehicle, comprising: a throttle valve opening calculation means for calculating a throttle valve opening with respect to the target air amount with correction based on at least one of water temperature and intake air temperature.