JP2550694B2 - Vehicle engine output control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to an engine output control method for a vehicle, which makes a target engine output the engine output of the vehicle.

(Prior Art) Conventionally, as one of controlling an engine so that an engine output becomes a predetermined target engine torque, an acceleration slip prevention device (traction that prevents slippage of driving wheels that occurs when an automobile is suddenly accelerated). Control device) is known. In such a traction control device, when the acceleration slip of the driving wheels is detected, the slip ratio S is controlled so that the friction coefficient μ between the tire and the road surface is in the maximum range (hatched range in FIG. 18).
Here, the slip ratio S is [(VF−VB) / VF] × 100 (percent), VF is the wheel speed of the drive wheels, and VB is the vehicle body speed. That is, when the slip of the driving wheels is detected, the engine output is controlled so that the slip ratio S is in the shaded range, so that the friction coefficient μ between the tire and the road surface is
Is controlled to be within the maximum range to prevent slipping of the drive wheels during acceleration and improve the acceleration performance of the vehicle.

(Problems to be Solved by the Invention) In such a trunkion control device, when a slip of the driving wheels is detected, it is required to control the engine output to a target engine output in which no slip occurs. It For example, in a traction control device that has a main throttle valve that interlocks with an accelerator pedal and a sub-throttle valve that is electrically controlled in the intake path of the engine, in order to obtain a target engine output, the opening of the main throttle valve is It is necessary to control the opening of the sub throttle valve in consideration.

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

[Configuration of the Invention] (Means and Actions for Solving the Problem) A main throttle valve whose opening is controlled in accordance with an operation amount of an accelerator pedal in an intake path to a vehicle engine and an opening electrically A target engine to be output from the engine in an engine output control method for controlling an output of the engine by providing a controlled sub-throttle valve in an intake passage of a vehicle engine and controlling an opening of the sub-throttle valve. Calculate the torque, using the target engine torque and the opening of the main throttle valve, to obtain the target opening of the sub-throttle valve necessary to output an engine torque equal to the target engine torque from the engine, The engine output of the vehicle is characterized in that the auxiliary throttle valve is controlled so that the opening of the auxiliary throttle valve becomes the target opening. It is a control method.

(Embodiment) Hereinafter, an acceleration slip prevention device for a vehicle in which an engine output control method 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 block diagram showing an acceleration slip prevention device for a vehicle. The figure shows a front-wheel drive vehicle, where WFR is the front wheel right wheel, WFL is the front wheel left wheel, WRR is the rear wheel right wheel, and WRL is the rear wheel left wheel. Further, 11 is a wheel speed sensor that detects the wheel speed VFR of the front right wheel (driving wheel) WFR, 12 is a wheel speed sensor that detects the wheel speed VFL of the front left wheel (driving wheel) WFL, and 13 is a rear right wheel. (Driven wheel) WRR wheel speed VRR
Is a wheel speed sensor for detecting the wheel speed sensor 14 and 14 is a wheel speed sensor for detecting the wheel speed VRL of the rear left wheel (driven wheel) WRL. Wheel speed V detected by the wheel speed sensors 11 to 14
FR, VFL, VRR, VRL are input to the traction controller 15. The traction controller 15 includes an intake air temperature AT detected by an intake air temperature sensor (not shown), an atmospheric pressure AP detected by an atmospheric pressure sensor (not shown), an engine speed Ne detected by a rotation sensor (not shown), and an air flow sensor (not shown). Intake air amount A / N per cycle of engine rotation detected at 1, transmission oil temperature OT detected by an oil temperature sensor not shown, engine cooling water temperature WT detected by a water temperature sensor not shown, air conditioner switch not shown Operating state of power steering switch SW, not shown, idle switch operating state not shown, power steering pump oil temperature not shown OP, cylinder pressure CP of engine cylinder detected by cylinder pressure sensor not shown, fuel chamber wall not shown Engine combustion chamber wall temperature CT detected by temperature sensor, alternator exciting current iΦ A post-start elapsed time τ output from a timer (not shown) that counts the time after the engine is started 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
Reference numeral 16 denotes a main throttle valve THm whose opening Θ1 is operated by an accelerator pedal as shown in FIG. 1 (A), and its opening Θ2 is controlled by an opening signal Θs described later from the traction controller 15. Sub throttle valve TH
have s. The opening Θ2 of the auxiliary throttle valve THs is controlled by the motor drive circuit 52 controlling the rotation of the motor 52m by 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 THm in this way. The opening degrees Θ1 and Θ2 of the main throttle valve THm and the sub throttle valve THs are detected by throttle position sensors TPS1 and TPS2, respectively, and output to the motor drive circuit 52. Further, a bypass passage 52b is provided between the upstream and downstream of the main and auxiliary throttle valves THm, THs to secure an intake air amount during idling,
The opening amount of the bypass passage 52b is controlled by the stepper motor 52s. In addition, the above main and sub throttle valves THm, TH
A bypass passage 52c is provided between the upstream and downstream of s, and a wax valve 52W whose opening is adjusted according to the cooling water temperature WT of the engine 16 is provided in the bypass passage 52c.

Further, 17 is a wheel cylinder for controlling the front right wheel WFR, and 18 is a wheel cylinder for controlling the front left wheel WFL. Normally, pressure oil is supplied to these wheel cylinders by operating a flex pedal (not shown). When the traction control is activated, it is possible to supply hydraulic pressure from another route described below. The pressure oil is supplied from the hydraulic pressure source 19 to the wheel cylinder 17 through the inlet valve 17i, and the pressure oil is discharged from the wheel cylinder 17 to the razor 20 through the outlet valve.
Through 17o. In addition, the wheel cylinder 18
Pressure oil from the hydraulic source 19 to the inlet valve 18i
Through the wheel cylinder 18 from the reservoir
The pressure oil is discharged to 20 through an outlet valve 18o. The inlet valve 17i and 18i and the outlet valve 17o and 18o open / close control are performed by the traction controller 15.

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

In the figure, 11 and 12 are wheel speeds VF of the drive wheels WFR and WFL.
It is a wheel speed sensor for detecting R, VFL, and the drive wheel speeds VFR, VFL detected by the wheel speed sensors 11, 12 are
Both are sent to the high vehicle speed selection unit 31 and the averaging unit 32. The high vehicle speed selection unit 31 selects the high wheel speed side of the drive wheel speeds VFR and VFL, and the drive wheel speed selected by the high vehicle speed selection unit 31 is output to the weighting unit 33. Further, the averaging unit 32 calculates the average drive wheel speed (VFR) from the drive wheel speeds VFR and VFL obtained from the wheel speed sensors 11 and 12.
+ VFL) / 2 is calculated, and the average driving wheel speed calculated by the averaging unit 32 is output to the weighting unit 34.
The weighting unit 33 multiplies the wheel speed of the drive wheel WFR or WFL selected and output by the high vehicle speed selection unit 31 by KG (variable), and the weighting unit 34 outputs the average by the averaging unit 32. Average driving wheel speed multiplied by (1-KG) (variable)
Therefore, the drive wheel speed and the average drive wheel speed weighted by the weighting units 33 and 34 are given to the addition unit 35 and added to calculate the drive wheel speed VF.

Here, the variable KG is a variable that changes according to the centripetal acceleration GY, as shown in FIG. 3, and is proportional to the magnitude of the centripetal acceleration GY up to a predetermined value (for example, 0.1 g). As described above, the value is set to "1".

On the other hand, the driven wheel speeds VRR and VRL detected by the wheel speed sensors 13 and 14 are both sent to the low vehicle speed selection unit 36 and the high vehicle speed selection unit 37. The low vehicle speed selection unit 36 uses the driven wheel speed V
The low wheel speed side of RR, VRL is selected, and the high vehicle speed selection section 37 selects the high wheel speed side of the driven wheel speeds VRR, VRL. The determined low driven wheel speed is fed to the weighting unit 38, and the high vehicle speed selection unit
The high driven wheel speed selected by 37 is output to the weighting unit 39. The weighting unit 38 multiplies (variable) the wheel speed of the lower one of the driven wheels WRR, WRL selected and output by the low vehicle speed selection unit 36 by a variable, and the weighting unit 39 uses the high vehicle speed selection unit 37. The wheel speed of the higher one of the driven wheels WRR and WRL selectively output by (1) is multiplied by (1-Kr) (variable),
The driven wheel speeds weighted by the weighting units 38 and 39 are given to the addition unit 40 and added to each other to obtain the driven wheel speed V.
R is calculated. The driven wheel speed VR calculated by the adder 40 is output to the multiplier 40 '. This multiplication unit 40 'is
The above-calculated driven wheel speed VR is multiplied by (1 + α), and the target drive wheel speed Vφ based on the driven wheel speeds VRR and VRL is calculated through this multiplication unit 40 '.

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 drive wheel speed V calculated by the adder 35
F, and target drive wheel speed V calculated by the multiplication unit 40 '
φ is given to the subtraction unit 41. The subtraction unit 41 subtracts the target drive wheel speed Vφ from the drive wheel speed VF to calculate the slip amount DVi (VF-Vφ) of the drive wheels WFR and WFL. The slip calculated by the subtraction unit 41 Quantity DVi ′
Is given to the addition unit 42. The adder 42 corrects the slip amount DVi ′ according to the centripetal acceleration GY and its change rate ΔGY. The slip correction amount Vg (see FIG. 5) that changes according to the centripetal acceleration GY is the slip amount. The slip correction amount Vd (see FIG. 6) given from the correction unit 43 and changing according to the change rate ΔGY of the centripetal acceleration GY is the slip amount correction unit.
Given by 44. That is, in the adder 42, the slip correction amounts Vg, Vd are added to the slip amount DVi ′ obtained from the subtractor.
And the slip amount corrected according to the centripetal acceleration GY and its change rate ΔGY via the adding section 42.
DVi is, for example, a TSn calculation unit for each sampling time T of 15 ms.
45 and TPn calculation unit 46.

The calculation unit 45a in the TSn calculation unit 45 uses the slip amount DV
Integral type correction torque TSn ′ (=
ΣKI.DVi), and this integral type correction torque TS
n ′ is sent to the coefficient multiplication unit 45b. That is, the integral type correction torque TSn 'is a correction value for the drive torque of the drive wheels WFR, WFL, and the gear shift characteristic of the power transmission mechanism existing between the drive WFR, WFL and the engine 16 changes. It is necessary to adjust the control gain accordingly, and the coefficient multiplication unit 45b
Then, the integral type correction torque TS obtained from the above calculation unit 45a
Multiply n ′ by a coefficient GKi that differs depending on the shift speed, and calculate an integral correction torque TSn corresponding to the shift speed. Here, the variable KI is a coefficient that changes according to the slip amount DVi.

On the other hand, the calculation unit 46a in the TPn calculation unit 46 calculates the proportional correction torque TPn '(= the slip amount DVi multiplied by the coefficient Kp.
DViKp), and this proportional correction torque TPn ′
Is sent to the coefficient multiplication unit 46b. That is, this proportional correction torque TPn 'is also a correction value for the drive torque of the drive wheels WFR, WFL, like the integral correction torque TSn', and the power existing between the drive wheels WFR, WFL and the engine 16 is the same. It is necessary to adjust the control gain according to the change of the speed change characteristic of the transmission mechanism.In the coefficient multiplication unit 46b, the proportional correction torque TSn ′ obtained from the calculation unit 46a is changed by a coefficient that is different depending on the speed. GKp is multiplied to calculate the proportional correction torque TPn corresponding to the gear.

On the other hand, the driven wheel speed VR obtained by the adder 40
Is sent to the reference torque calculation unit 47 as the vehicle body speed VB. The reference torque calculation unit 47 is a vehicle acceleration calculation unit.
The acceleration GB of the vehicle body speed VB is calculated in 47a, and the vehicle body acceleration GB obtained by the vehicle body acceleration calculation unit 47a is sent to the reference torque calculation unit 47c as the vehicle body acceleration GBF via the filter 47b. This reference torque calculation unit 47c
Is to calculate a reference torque TG (= GBF × W × Re) based on the vehicle body acceleration GBF, the vehicle weight W and the wheel radii Re, and the reference torque TG is an axle torque value that the engine 16 should originally output. .

The filter 47b determines, for example, in three stages how much the reference torque TG calculated by the reference torque calculation unit 47c is calculated based on the front vehicle acceleration GB in time, that is, it is obtained through this filter 47b. The vehicle body acceleration GBF is obtained from the vehicle body acceleration GBn detected this time and the vehicle body acceleration GBFn-1 which is the output of the filter 47b up to the previous time.
It is calculated according to the current slip ratio S and the acceleration state.

For example, when the vehicle acceleration is currently increasing and the slip ratio S is in the state shown in the range “1” in FIG. 15, the vehicle body acceleration GBF is changed to quickly shift to the state “2”. Is calculated by the following equation (1) as the latest vehicle body acceleration GBF by averaging the previous output of the filter 47b, GBF-1, and the current detected GBn with the same weighting.

GBFn = (GBn + GBFn-1) / 2 (1) Further, for example, when the acceleration of the vehicle is currently decreasing, the slip ratio S is S> S1 and the range is "2" shown in FIG.
In the case of shifting to "3", in order to maintain the state of "2" as much as possible, the vehicle body acceleration GBF has a value close to the previous output GBFn-1 of the filter 47b.
It is calculated as n by the following equation (2).

GBFn = (GBn + 7GBFn-1) / 8 (2) Further, for example, when the acceleration of the vehicle is currently decreasing, the slip ratio S is S ≦ S1 and “2” shown in FIG. 15 →
When the state shifts to "1", the vehicle body acceleration GBF is further weighted by the output GBFn-1 of the previous filter 47b in order to return the state to the range "2" as much as possible, and the above equation ( Compared with the case of calculation in 2), the previously calculated vehicle acceleration G
The vehicle body acceleration GBFn having a value close to BFn-1 is calculated by the following equation (3).

GBFn = (GBn + 15GBFn-1) / 16 (3) Next, the reference torque TG calculated by the reference torque calculation unit 47 is output to the subtraction unit 48. This subtraction unit 48
Is the reference torque T obtained from the reference torque calculation unit 47.
Integral type correction torque calculated from G by the TSn calculation unit 45
TSn is subtracted, and the subtracted data is further subtracted by the subtraction unit 4
Sent to 9. The 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, WFL. The target torque Tφ of the axle torque to be transmitted is sent to the engine torque conversion unit 500 via the switch S1. That is, Tφ = TG-TSn-TPn.

The engine torque conversion unit 500 divides the target torque Tφ for the drive wheels WFR and WFL given from the subtraction unit 49 via the switch S1 by the total gear ratio between the engine 16 and the drive wheel axle. Converted to target engine torque T1. This target engine torque T1 is output to the torque converter response delay correction unit 501. This torque converter response delay correction unit 501
Outputs the target engine torque T2 by correcting the engine torque T1 according to the response delay of the torque converter (not shown). This target engine torque T2 is output to the T / M (transmission) friction correction unit 502. In the T / M friction correction unit 502, the target engine torque T2 is added with the loss of the engine torque due to the friction in the transmission to obtain the target engine torque T3. This target engine torque T3 is output to the external load correction unit 503. In the external load correction unit 503, the target engine torque T4 is calculated by adding the loss of the engine torque due to the electric load such as the air conditioner to the target engine torque T3. This target engine torque T4
Is output to the atmospheric condition correction unit 504. In the atmospheric condition correction unit 504, the target engine torque T4 is corrected by the atmospheric condition, that is, the atmospheric pressure AP, to obtain the target engine torque.
T5. Further, the target engine torque T5 is output to the operating condition correction unit 505. In the operating condition correction unit 505, the target engine torque T5 is corrected according to the operating state of the engine, for example, the engine cooling water temperature WT, and the target engine torque T6 is output to the lower limit value setting unit 506. The lower limit value setting unit 506 sets the lower limit value of the target engine torque T6 to a lower limit value Tlim that changes according to the elapsed time t from the start of traction control or the vehicle body speed VB, as shown in, for example, FIGS. Then, the target engine torque T7 is output as the target engine torque T7. Then, this target engine torque T7 is output to the target air amount calculation unit 507. The target air amount calculation unit 507 outputs the target engine torque T7 in the engine 16 by the target air amount (mass) A / per engine revolution.
Nm is calculated, and this target air amount A / Nm is calculated based on the engine speed Ne and the target engine torque T7, and the target air amount (mass) A / Nm is obtained by referring to the three-dimensional map in FIG. To be

A / Nm = f [Ne, T7] where A / Nm is the intake air amount (mass) per engine revolution, and f [Ne, T7] is the engine speed Ne, target engine torque.
It is a three-dimensional map using T7 as a parameter.

Further, in the target air amount calculation section 507, the target air amount (mass) A / Nm is corrected by the intake air temperature AT and the atmospheric pressure AP by the following formula, and the target air amount (volume) A / Nv in the standard atmospheric condition is obtained. Is converted to.

A / Nv = (A / Nm) / {Kt (AT) * Kp (AP)} where A / Nv is the intake air amount (volume) per engine revolution, and Kt is the intake air temperature (AT) as a parameter. The corrected density correction coefficient (see FIG. 37) and Kp are the density correction coefficient with the atmospheric pressure (AP) as a parameter (see FIG. 38).

The target air amount A / Nv (volume) is the target air amount correction unit 508.
The target air amount is corrected by the intake air temperature.
A / N0 is calculated by the following formula.

A / N0 = A / Nv * Ka '(AT) where A / N0 is the target air amount after correction, A / Nv is the target air amount before correction, and Ka' is the correction coefficient (AT) based on the intake air temperature (AT). First
(See Figure 38).

The target air amount A / N0 is the target throttle opening calculation unit 509.
The target air amount A / N0 and the target throttle opening Θ2 'for the opening Θ1 of the main throttle valve THm are obtained by referring to the three-dimensional map of FIG. The three-dimensional map shown in FIG. 39 is obtained as follows. That is, the main throttle valve THm opening Θ1 or the auxiliary throttle valve THs opening Θ
When 2 is changed, the intake air amount per engine revolution is grasped as data, and the relationship between the opening Θ2 of the main throttle valve THm and the sub throttle valve THs corresponding to the intake air amount per engine revolution is shown. It's a map that I asked for.

The target throttle opening Θ2 ′ is sent to the opening correction unit 510 for the bypass air amount, and is subtracted by the opening amount ΔΘ corresponding to the air amount through the bypass passages 52b and 52c to open the target throttle opening of the auxiliary throttle valve THs. The degree Θ2 is calculated.

On the other hand, the corrected target air amount A / N0 output from the target air amount correction unit 508 is also sent to the subtraction unit 513. This subtraction unit 513 calculates the deviation ΔA / N between the target air amount A / N0 and the actual intake air amount A / N detected at every predetermined sampling time by the air flow sensor. The deviation ΔA / N between / N0 and the actual air amount A / N is sent to the PID control unit 514. The PID control unit 507 calculates the opening correction amount ΔΘ2 of the sub-throttle valve THs corresponding to the deviation ΔA / N, and the sub-throttle valve opening correction amount ΔΘ2 is added by the addition unit.
Sent to 515.

Here, the auxiliary throttle valve opening correction amount ΔΘ2 obtained by the PID control unit 514 is an opening correction amount Δ by proportional control.
Θp, the opening correction amount ΔΘi by the integral control, and the opening correction amount ΔΘd by the differential control are added.

ΔΘ2 = ΔΘp + ΔΘi + ΔΘd ΔΘp = Kp (Ne) * Kth (Ne) * ΔA / N ΔΘi = Ki (Ne) * Kth (Ne) * Σ (ΔA / N) ΔΘd = Kd (Ne) * Kth (Ne) * {ΔA / N-ΔA / Nold} where the coefficients Kp, Ki, Kd are proportional gain (see Fig. 40), integral gain (see Fig. 41), and differential gain (see Fig. 41) with the engine speed Ne as a parameter. (See Fig. 42), and Kth is ΔA with the engine speed Ne as a parameter.
/ N → ΔΘ conversion gain (see Fig. 43), ΔA / N is the deviation between the target air amount A / N0 and the actual air amount A / N, and ΔA / Nold is the ΔA / N at the previous sampling timing. 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 feedback-corrected the target opening Θ2. The degree Θf is calculated. This target opening Θf is sent to the motor drive circuit 52 as a sub-throttle valve opening signal Θs. The motor drive circuit 52 controls the rotation of the motor 52m so that the opening Θ2 of the sub throttle valve THs detected by the throttle position sensor TPS2 becomes equal to the opening corresponding to the sub throttle valve opening signal Θt. ing.

By the way, the centripetal acceleration GY ′ is obtained in order to determine the turning degree by being sent to the centripetal acceleration calculation unit 53 such as the wheel speeds VRR and VRL of the driven wheels. The centripetal acceleration GY ′ is sent to the centripetal acceleration correction unit 54, and the centripetal acceleration GY ′ is corrected according to the vehicle speed. That is, GY = Kv · GY ′. Where Kv
Is a coefficient that changes according to the vehicle body speed VB as shown in FIGS.

The larger driven wheel wheel speed output from the high vehicle speed selection section 37 is subtracted from the wheel speed VFR of the drive wheel in the subtraction section 55. Further, the larger driven wheel speed output from the high vehicle speed selection section 37 is subtracted from the wheel speed VFL of the drive wheels in the subtraction section 56.

The output of the subtractor 55 is multiplied by KB in the multiplier 57 (0 <
KB <1), the output of the subtraction unit 56 is multiplied by (1-KB) in the multiplication unit 58, and then added in the addition unit 59 to obtain the slip amount DVFR of the right driving wheel. At the same time, the output of the subtractor 56 is multiplied by KB in the multiplier 60, and the output of the subtractor 55 is (1-K
B) After being multiplied, it is added in the addition unit 62 to be the slip amount DV FL of the left drive wheel. As shown in FIG. 13, the variable KB changes according to the elapsed time from the start of the control of the traction control, and is set to "0.5" at the start of the control of the traction control, and becomes "0.8" as the control of the traction control progresses. Is set to approach.

The slip amount DVFR of the right drive wheel is differentiated in a differentiator 63 to calculate its time change amount, that is, the slip acceleration GFR, and the slip amount of the left drive wheel is calculated.
The DV FL is differentiated in the differentiator 64 to calculate its temporal change amount, that is, the slip acceleration G FL. And
The slip acceleration GFR is the brake fluid pressure change amount (ΔP).
The change amount ΔP of the brake hydraulic pressure for suppressing the slip acceleration GFR is obtained by referring to the GFR (GFL-P conversion map) shown in FIG. ΔP is sent to the ΔP-T converter 67 through the switch S2 which is controlled to open / close by the start / end determination unit 50, and the opening time T of the inlet valve 17i in FIG. 1A is calculated. Similarly, the slip acceleration GFL is sent to the brake fluid pressure change amount (ΔP) calculation unit 66, and the GFR (GFL) -ΔP conversion map shown in FIG. 14 is referred to for controlling the slip acceleration GFL. A change amount ΔP of the brake hydraulic pressure is obtained, and the change amount ΔP of the brake hydraulic pressure is sent to the ΔP-T converter 68 via the switch S3 whose opening / closing is controlled by the start / end determination unit 50.
In the figure (A), the opening time T of the inlet valve 18i is calculated. Then, the valves are controlled to open for the opening time T of the inlet valve 17i and the outlet valve 18i calculated as described above, and the right drive wheel WFR and the left drive wheel WFL are controlled.
Is braked.

The switches S1 to S3 are opened / closed by the start / end determination unit 50 in conjunction with each other.

By the way, the slip amount DV calculated by the subtraction unit 41 is
i ′ is sent to the differentiator 41a, and the temporal change rate ΔDVi ′ of the sweep amount DVi ′ is calculated. The slip amount DVi ′, the rate of change ΔDVi ′ thereof with time, the opening 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 determination unit 50. The start / end determination unit 50 uses the slip amount DVi ′,
When the time change rate ΔDVi and the engine torque Te both exceed the respective reference values, the switches S1 to S3 are closed to start the control, and the auxiliary throttle valve THs
The opening Θ2 of is larger than the specified reference value, or DV
When i'is smaller than a predetermined reference value (different from the reference value), the switches S1 to S3 are opened and the control is ended.

Incidentally, in FIG. 14, when the brake is applied at the time of turning, in order to strengthen the brake of the inner drive wheel,
The conversion value on the inner wheel side when turning is shown by a broken line a.

Next, the operation of the vehicle engine output control method according to the embodiment of the present invention configured as described above will be described. In FIGS. 1 and 2, the wheel speed sensors 13 and 14 are shown.
The wheel speed of the driven wheels (rear wheels) output from
36, the low vehicle speed selection unit 37, and the centripetal acceleration calculation unit 53.
The low vehicle speed selecting section 36 selects the smaller wheel speed of the left and right driven wheels, and the high vehicle speed selecting section 37 selects the larger wheel speed of the left and right driven wheels. During normal straight running, when the wheel speeds of the left and right driven wheels are the same, the same wheel speed is selected from the low vehicle speed selection unit 36 and the high vehicle speed selection unit 37. Further, in the centripetal acceleration calculation unit 53, the wheel speeds of the left and right driven wheels are input, and the turning degree when the vehicle is turning from the wheel speeds of the left and right driven wheels, that is, how sharp a turn is made. The degree of whether or not it is calculated is calculated.

Hereinafter, how the centripetal acceleration calculation unit 53 calculates the centripetal acceleration will be described. In a front-wheel drive vehicle, since the open wheels are driven wheels, the vehicle speed at that position can be detected by the wheel speed sensor regardless of slippage due to driving, and therefore Ackermann geometry can be used. That is, in the steady turn, the centripetal acceleration GY ′ is calculated as GY ′ = v ² / r (4) (v = vehicle speed, r = turn radius).

For example, when the vehicle is turning to the right as shown in FIG. 19, the turning center is Mo, the distance from the turning center Mo to the inner wheel side (WRR) is r1, the tread is Δr, and the inner wheel is The wheel speed on the side (WRR) is v1, and the outer wheel side (WR
When the wheel speed of L) is v2, v2 / v1 = (Δr + r0) / r1 (5).

Then, the above equation (5) is modified to be 1 / r1 = (v2-v1) / Δr · v1 (6). The centripetal acceleration G is based on the inner ring side.
Y 'is GY' is calculated as ^{= v1 2 / r1 = v1 2} · (v2-v1) / Δr · v1 = v1 · (v2-v1) / Δr ... (7).

That is, the centripetal acceleration GY 'is calculated by the above equation (7). By the way, since the wheel speed v1 on the inner wheel side is smaller than the wheel speed v2 on the outer wheel side during turning, the centripetal acceleration GY ′ is calculated using the wheel speed v1 on the inner wheel side.
GY 'is calculated smaller than the actual value. Therefore, the weighting unit
The coefficient KG multiplied by 33 is underestimated because the centripetal acceleration GY 'is underestimated. Therefore, since the drive wheel speed VF is estimated to be small, the slip amount DV '
(VF-VΦ) is also underestimated. As a result, the target torque TΦ is largely estimated, so that the target engine torque is largely estimated, so that a sufficient driving force is applied even during turning.

By the way, in the case of extremely low speed, as shown in FIG. 19, the distance from the inner wheel side to the center M0 of turning is r1,
In vehicles that understeer as speed increases, the center of turning moves to M and the distance is r (r> r1)
Has become. Even when the speed is increased in this way, the centripetal acceleration GY ′ calculated based on the above equation (7) is calculated as a value larger than the actual value because the turning radius is calculated as r1. Therefore, the centripetal acceleration calculation unit 53
The centripetal acceleration GY ′ calculated in
In step 54, the centripetal acceleration GY 'is multiplied by the coefficient Kv of FIG. 7 so that the centripetal acceleration GY becomes small at high speed. This variable Kv is set to be small according to the vehicle speed, and may be set as shown in FIG. 8 or FIG. In this way, the centripetal acceleration GY corrected by the centripetal acceleration correction unit 54 is output.

On the other hand, as the speed increases, oversteering (r
<R1) In the vehicle, the centripetal velocity correction unit 54 performs a correction that is completely opposite to the above-described understeering vehicle. That is, any one of the variables Kv in FIG. 10 to FIG. 12 is used to correct the centripetal acceleration GY ′ calculated by the centripetal acceleration calculation unit 53 as the vehicle speed increases.

By the way, the smaller wheel speed selected by the low vehicle speed selector 36 is multiplied by a variable Kr in the weighting unit 38 as shown in FIG. 4, and the high vehicle speed selected by the high vehicle speed selector 37 is weighted by the weighting unit 39. Is multiplied by the variable (1-Kr). The variable Kr is set to "1" during turning when the centripetal velocity GY becomes larger than 0.9 g, and the centripetal acceleration GY is
When it is less than 0.4g, it is set to "0".

Therefore, for turning in which the centripetal acceleration GY is larger than 0.9 g, the wheel speed of the low vehicle speed among the driven wheels output from the low vehicle speed selection unit 36, that is, the wheel speed on the inner wheel side at the time of selection is selected. It Then, the weighting unit 38 and
The wheel speed output from 39 is added in the adder 40 to obtain the driven wheel speed VR, and the driven wheel speed VR is multiplied by (1 + α) in the multiplier 40 'to obtain the target drive wheel speed V.
Φ.

In addition, after the wheel speed of the larger one of the wheel speeds of the drive wheels is selected by the high vehicle speed selection section 31, the weighting section 33 multiplies the variable KG by a variable KG as shown in FIG. further,
Average vehicle speed of drive wheels calculated by averaging unit 32 (VFR +
VFL) / 2 is multiplied by (1-KG) in the weighting unit 34, and added by the output of the weighting unit 33 and the adding unit 35 to obtain the driving wheel speed VF. Therefore, when the centripetal acceleration GY is, for example, 0.1 g or more, KG = 1, so that the wheel speed of the larger drive wheel of the two drive wheels output from the high vehicle speed selection unit 31 is output. Become. That is,
The centripetal acceleration GY is, for example, 0.
When it is 9g or more, "KG = Kr = 1" is satisfied. Therefore, the driving wheel side has the wheel speed on the outer wheel side with the higher wheel speed as the driving wheel speed VF, and the driven wheel side has the wheel speed on the inner wheel side with the lower wheel speed. Therefore, the slip amount DVi ′ (= VF−VΦ) calculated by the subtraction unit 41 is estimated to be large. Therefore, since the target torque TΦ is underestimated, 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. Can be raised to make a safe turn.

The slip amount DVi 'is added to the slip amount correcting unit 43 with the slip correction amount Vg as shown in FIG. 5 only at the time of turning when the centripetal acceleration GY is generated, and the slip amount correcting unit 44 shows it in FIG. Such slip amount Vd is added. For example, assuming a turn of a curve that bends at a right angle, the centripetal acceleration GY and its temporal change rate ΔGY are positive values in the first half of the turn, but the temporal change rate of the centripetal acceleration GY in the latter half of the curve. ΔGY has a negative value. Accordingly, in the first half of the curve, the slip correction amount Vg shown in FIG.
(> 0) and the slip correction amount Vd (> 0) shown in FIG. 6 are added to obtain the slip amount DVi. In the latter half of the curve, the slip correction amount Vg (> 0) and the slip correction amount Vd
(<0) is added to obtain the slip amount DVi. Therefore, by estimating the slip amount DVi in the latter half of the turn to be smaller than the slip amount DVi in the first half of the turn, the engine output is reduced in the first half of the turn to increase the lateral force, and in the latter half of the turn, The engine output is restored to improve vehicle acceleration.

In this way, the corrected slip amount DVi is, for example, 1
It is sent to the TSn calculation unit 45 at a sampling time T of 5 ms. In the TSn calculator 45, the slip amount DVi is multiplied by a coefficient KI and integrated to obtain a correction torque TSn.
That is, the correction torque obtained by correcting the slip amount DVi, that is, the integral correction torque TSn is obtained as TSn = GKiΣKI · DVi (KI is a coefficient that changes according to the slip amount DVi).

The slip amount DVi is T at every sampling time T.
The correction torque TPn is sent to the Pn calculation unit 46 and is calculated.
That is, the correction torque corrected by the slip amount DVi, that is, the proportional correction torque TPn is obtained as TPn = GKpDVi · Kp (Kp is a coefficient).

Further, the values of the coefficients GKi, GKp used for the calculation in the coefficient multiplying units 45b, 46b are switched to values according to the shift stage after the shift during the set time from the shift start at the time of shift-up. This takes time from the start of gear shifting until the gear is actually switched and the gear shifting ends, and at the time of upshifting, the coefficient GKi, GK
When p is used, the values of the correction torques TSn and TPn become values corresponding to the above-mentioned high speed stages, so that the actual torque change is not finished, but it is smaller than the value before the shift start and the target torque TΦ becomes large. This is because slip is induced and control becomes unstable.

The driven wheel speed VR output from the adder 40 is input to the reference torque calculator 47 as the vehicle body speed VB.
Then, the vehicle body acceleration calculation unit 47a calculates the vehicle body speed acceleration B (GB). Then, the acceleration GB of the vehicle body speed calculated by the vehicle body acceleration calculating section 47a is filtered by the filter 47b by any one of the above equations (1) to (3), and GBF is determined according to the state of the acceleration GB. Is designed to be stopped at the optimum position.

For example, when the slip rate S is in the state shown in the range "1" in FIG. 15 when the acceleration of the vehicle is currently increasing, the state is quickly changed to the range "2". As shown in the equation, the vehicle body acceleration GBFn is calculated as the latest vehicle body acceleration GBFn by averaging the previous output GBFn-1 of the filter 47b and the currently detected GBn with the same weighting.

Further, for example, when the acceleration of the vehicle is currently decreasing, the slip ratio S is S> S1 and the range "2" shown in FIG.
In the case of shifting to "3", in order to maintain the state of the range "2" as much as possible, the vehicle body acceleration GBF is given a weight on the output of the previous filter 47b as shown in the above equation (2). It is calculated and is calculated as the previous vehicle body acceleration GBFn.

Further, for example, when the acceleration of the vehicle is currently decreasing, the slip ratio S is S ≦ S1 and the range “2” shown in FIG.
When the state shifts to "1", the vehicle body acceleration GBF is extremely weighted by the output of the previous filter 47b as shown in the above equation (3) in order to return the state to the range "2" as much as possible. It is placed and calculated as the previous vehicle body acceleration GBFn.

Then, the reference torque calculation unit 47c calculates the reference torque TG (= GBF × W × Re).

Then, the reference torque TG and the integral correction torque T
Subtraction with Sn is performed in the subtraction unit 48, and the proportional correction torque TPn is further subtracted in the 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 conversion unit 500 via the switch S1 and divided by the total gear ratio between the engine 16 and the drive wheel axle to obtain the target engine torque T1.
Is calculated. The target engine torque T1 is corrected by the torque converter response delay correction unit 502 with respect to the response delay of the torque converter, and becomes the target engine torque T2. This target engine torque T2 is sent to the T / M friction correction unit 502, and is corrected for friction (friction) in the transmission interposed between the engine and the drive wheels, and becomes the target engine torque T3.

In the T / M rejection correction unit 502, the first described below
The target engine torque T3 is corrected by estimating the warm-up state of T / M by the fourth method.

<First T / M Friction Correction Method> In this first method, the oil temperature OT of the T / M is detected by an oil temperature sensor, and when the oil temperature OT is small, the friction is large. The map shown in is referred to and the torque correction amount Tf
Is added to the target engine torque T2. In other words, T3 = T2 + Tf (OT). Since the torque correction amount Tf due to friction is determined according to the T / M oil temperature OT in this way, it is possible to accurately correct the target engine torque with respect to the T / M friction.

<Second Method of T / M Friction Correction> The cooling water temperature WT of the engine 16 is measured by a sensor, and the warm-up state (oil temperature) of the T / M is estimated from this to correct the torque. In other words, T3 = T2 + Tf (WT). Here, the torque correction amount Tf (WT) is referred to a map not shown, and the lower the engine cooling water temperature WT is,
It is estimated that the oil temperature OT of T / M is low and the torque correction amount Tf is set to be large. In this way, since the T / M friction is estimated from the engine coolant temperature WT, the T / M
The sensor that detects the oil temperature OT is unnecessary.

<Third method of T / M friction correction> The torque correction amount Tf is added to the target engine torque T2 by referring to the map in FIG. 21 based on the cooling water temperature WTO immediately after the engine 16 is started and the real-time cooling water temperature WT. The target engine torque T3 is obtained. That is, T3 = T2 + Tf (XT) XT = WT + K0 * (WT-WTO). Here, XT is the estimated oil temperature of T / M, and K0 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. This estimated oil temperature XT, engine cooling water temperature
The relationship between the oil temperature OT of WT and T / M and the elapsed time after engine start is shown in FIG. As shown in FIG. 22, the change in XT of the estimated time with the elapse of the start time becomes substantially equal to the change in the oil temperature OT with the elapse of the start time. Therefore,
The oil temperature can be accurately monitored without using the oil temperature sensor.

<Fourth method of T / M friction correction> Based on the cooling water temperature WT of the engine 16, the elapsed time τ after starting the engine, and the vehicle speed Vc, T3 = T2 + Tf (WT) * {1-Kas (τ) * Kspeed (Vc) } Is calculated as Here, Kas is a tailing coefficient based on the time (τ) after the start (gradually becomes 0 as the time after the start elapses).
, And Kspeed is a tailing coefficient depending on the vehicle speed (a coefficient that gradually approaches 0 as the vehicle speed increases). That is, when a sufficient time has passed since the engine was started, or when the vehicle speed increased, the {...} term approaches "0". Therefore, the torque correction amount Tf due to the friction of T / M is eliminated when it is desired to sufficiently elapse after starting the engine or when the vehicle speed increases.

<Fifth Method of T / M Friction Correction> The output is corrected based on the engine or T / M rotation speed N, and the map of FIG. 23 is referred to based on the rotation speed N to determine the rotation speed N. Based on this, the torque correction amount Tf is calculated. That is, T3 = T2 + Tf (N). This is because as the engine or T / M rotation speed N increases, the T / M oil temperature rises and friction loss decreases.

<Sixth Method of T / M Friction Correction> This method is a method of obtaining a correction torque by estimating the integrated value of the cooling water temperature WT of the engine 16 and the intake air amount Q after the engine is started.

The target engine torque T3 is obtained as T3 = T2 + Tf (WT) * {1Σ (Kq * Q)}. Here, Kq is a coefficient that converts the intake air amount into loss torque, and is set to Kq = Kq1 when the clutch is off or the idle SW is on, and Kq = Kq0 otherwise. (> Kq1) is set.

In the above equation, the intake air amount Q after engine start is multiplied by the coefficient Kq to obtain Σ (Kq * Q),
The target engine torque T2 is obtained by multiplying Σ (Kq * Q)} by the torque correction amount TW (WT) based on the engine cooling water temperature WT. By doing so, when the vehicle is suddenly accelerated after the engine is started and the intake air amount Q is sharply increased, that is, even if the engine cooling water temperature WT is low, the transmission is warm enough and the T / M friction correction is performed. In the case where 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 in the idling state, the transmission is not sufficiently warmed up even if the idling state continues, so the integrated intake air amount Q should be made as small as possible. Based on the estimation, the torque correction amount Tf based on the engine cooling water temperature is used. In this way, even if the idling state is continued, the T / M friction correction is performed by leaving the Tf (WT) term. It should be noted that the cumulative intake air amount Q for each fixed time is calculated based on the intake air amount A / N per engine cycle.

Further, the friction torque Tf of T / M is 3 as shown in FIG.
You may make it calculate using a dimension map. In this case, the target engine torque T3 is expressed by the following equation. That is, T3 = T2 + Tf (WT, ΣQa) By the way, in FIG. 24, Tf is set to be “0” when ΣQa exceeds a certain value. This is because it is determined that the T / M oil has been sufficiently warmed and the T / M friction can be ignored when the total intake air amount exceeds a certain value.

<Seventh Method of T / M Friction Correction> The torque correction amount Tf is obtained from the cooling water temperature WT of the engine 16 or the oil temperature of the engine 16 and the traveling distance ΣVs after the engine is started. That is, T3 = T2 + Tf (WT) * {1-Σ (Kv * Vs)} where Kv is a coefficient for converting the travel distance (= ΣVs) into output correction, and the idle SW is turned on or the clutch is turned off. When the engine is idling, it is set to Kv = Kv1, and otherwise it is set to Kv = Kv2 (> Kv1).

In the above equation, the traveling distance ΣVs after engine start is multiplied by the correction coefficient Kv and integrated to obtain Σ (Kv * Vs),
A product obtained by multiplying {1-Σ (Kv * Vs)} by the torque correction amount Tf (WT) based on the engine coolant temperature WT is added to the target engine torque T2. By doing this,
When the vehicle travels after the engine is started and the traveled distance increases, the {...} term approaches "0" to eliminate unnecessary torque correction.

In addition, since the load of the transmission is small in the idling state, the oil temperature of the transmission increases slowly. Therefore, the torque loss in the transmission gradually decreases. Therefore, by setting Kv to a small value in the idling state, {...}
The term is slowly brought to "0" so that the torque correction Tf is performed as long as possible.

Next, the engine torque T3 output from the T / M friction correction unit 502 is sent to the external load correction unit 503, and when there is an external load such as an air conditioner, the target engine torque T3
Is corrected to obtain the target engine torque T4. The correction by the external load correction unit 503 is performed by any one of the following first to third methods.

<First Method of External Load Correction> The target engine torque T3 is corrected according to the air conditioner load to obtain the target engine torque T4. 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 target engine torque T3 is added to the loss torque TL corresponding to the air conditioner load to obtain the target engine torque T4, thereby preventing a decrease in engine output due to the air conditioner load. There is.

Further, paying attention to the fact that the magnitude of the air conditioner load changes according to the engine rotation speed Ne, the loss torque TL corresponding to the engine rotation speed Ne is stored in a map as shown in FIG. The engine torque T4 may be calculated. That is, T4 = T3 + TL (Ne) may be used.

<Second method of external load correction> Target engine torque according to power steering load
Correct T3 to obtain the target engine torque T4. That is, T4 = T3 + TL. Here, TL is set to a constant value when the power steering is turned on, and is set to "0" when the power steering is turned off. In this way, when there is a power steering load, the target engine torque T3 is added to the loss torque TL corresponding to the power steering load to obtain the target engine torque T4, thereby reducing the engine output due to the power steering load. To prevent.

Also, paying attention to the fact that the magnitude of the power steering load changes according to the power steering pump oil pressure OP, as shown in FIG. 26, the loss torque T corresponding to the power steering pump oil pressure OP is obtained.
L is stored in the map, and the target engine torque T4
May be calculated. That is, T4 = T3 + TL (O
P) is also good.

<Third method of external load correction> The target engine torque T3 is corrected according to the electric load,
Seeking the target engine torque T4. That is, the electric load such as the headlight and the electric fan fluctuates, and the alternator power generation amount fluctuates. Therefore, the electrical load is estimated by estimating the alternator power generation amount by detecting the battery voltage and the exciting current of the alternator.

Target engine torque T4 when battery voltage is Vb
Is as follows.

T4 = T3 + TL (Vb) Here, the loss torque TL (Vb) has a relationship with the Batter voltage Vb as shown in FIG. That is, the battery voltage
When Vb is low, it is estimated that the electric load is large and 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 with the alternator exciting current (iΦ) as a parameter. That is, T4 = T3 + TL (iΦ, Ne) is calculated. Here, the loss torque TL is obtained with reference to the map shown in FIG.

Further, the target engine torque T4 may be calculated from the following equation by obtaining the correction amount K of the alternator efficiency with respect to the engine rotation speed Ne from the characteristic diagram shown in FIG.

T4 = T3 + TL (iΦ, Ne) × K (Ne) The target engine torque T4 calculated as described above is sent to the atmospheric condition correction unit 504, and the target engine torque T4 is corrected by the atmospheric pressure and the target engine torque T4 is corrected. Torque is T5. That is, T5 = T4 + Tp (AP) where Tp is the torque correction amount shown in the map of FIG. That is, in a region where the atmospheric pressure is low, such as in a highland, the engine output increases due to the improvement of the combustion speed due to the reduction of pumping loss and the reduction of back pressure. Therefore, the torque correction amount Tp is reduced accordingly.

In this way, the target engine torque T5 corrected by the atmospheric pressure is sent to the operating state correction unit 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 T5 is corrected. T6.
Hereinafter, the 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 T6 is determined by the engine cooling water temperature WT.
The map of FIG. 31 is referred to, and the torque correction amount TW is added to the target engine torque T5 according to the engine coolant temperature WT to obtain the target engine torque T6. That is, T6 = T5 + TW (WT). As shown in FIG. 31, the engine 16 is not warmed up as the cooling water temperature WT is lower, so the torque correction amount TW is increased.

Further, the torque correction amount TW may be mapped (not shown) with the engine cooling water temperature WT and the engine rotation speed Ne. That is, T6 = T5 + TW (WT, Ne).

<Second Method for Correcting Engine Operating Conditions> This second method is to add a torque correction amount Tas (τ) according to a time τ after engine start as shown in FIG. 32 to a target engine torque T5. As a result, the target engine torque T6 is obtained. In other words, T6 = T5 + Tas (τ). In this way, the warm-up state of the engine is estimated from the elapsed time τ after starting the engine.

In addition, the torque correction amount is determined by a three-dimensional map (not shown) determined by the engine start time τ and the cooling water temperature WT.
You may ask for Tas. That is, T6 = T5 + Tas (τ, WT) may be used. By using such a map, the cooling water temperature WTO at the start is measured, 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 determined.
The torque correction amount Tas may be determined by measuring.

<Third Technique for Correcting Engine Operating Conditions> In this third technique, the engine oil temperature OT
The torque correction amount Tj is obtained by referring to the map in FIG.
In other words, it is calculated as T6 = T5 + Tj (OT). In this way, the engine coolant temperature WT is estimated from the engine oil temperature OT to detect the engine warm-up state.

The torque correction amount Tj shown in a three-dimensional map of the engine oil temperature OT and the engine rotation speed Ne (not shown) may be obtained. That is, T6 = T5 + Tj (OT, Ne) may be used.

<Fourth method of engine operating condition correction> This fourth method is engine cooling water temperature WT, oil temperature OT, elapsed time after start τ, combustion chamber wall temperature CT, intake air amount Q, cylinder pressure CP.
The target engine torque T5 is corrected by some of the above to obtain the target engine torque T6. That is, T6 = T5 + Tc (CT / CT0) * Kcp (cp / cp0) * {1-Kq * Σ (Q)}.

Where CT is the temperature of the combustion chamber wall of the engine, CT0 is the temperature of the combustion chamber wall when the engine is started, Tc is the ratio of the temperature of the combustion chamber wall of the engine CT to the temperature of the combustion chamber wall when the engine is started (CT / CT0) Torque correction amount by, CP is the cylinder pressure of the engine, CP0 is the cylinder pressure at engine start, Kcp is the correction coefficient by the ratio of the above cylinder pressure CP and the cylinder pressure CP0 at engine start (CP / CP0), and Kq is the start This is a coefficient for converting the integrated value of the subsequent intake air amount into a torque correction coefficient.

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

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

In the target air amount calculation unit 507, the target air amount (mass) A / Nm is obtained from the engine speed Ne and the target engine torque Te1 by referring to the three-dimensional map in FIG. That is, it is calculated as A / Nm = f [Ne, T7].

Where A / Nm is the intake air amount (mass) per intake stroke, f [Ne, T7] is the engine speed Ne, target engine torque
It is a three-dimensional map using T7 as a parameter.

A / Nm may be obtained by multiplying the engine speed Ne by the coefficient Ka and the target engine torque T7 as shown in FIG. 35, 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 / Nm is corrected by the intake air temperature and the atmospheric pressure and converted into the intake air amount (constitution) A / Nv in the standard atmospheric condition.

That is, A / Nv = (A / Nm) / {Kt (AT) * Kp (AT)}. Where A / Nv is the intake air amount (volume) per engine revolution, Kt is the density correction coefficient with the intake air temperature (AT) as a parameter as shown in FIG. 37, and Kp is as shown in FIG. 38. The density correction coefficient with atmospheric pressure (AT) as a parameter is shown.

The target intake air amount A / Nv (volume) calculated in this way is corrected by the intake air temperature in the target air amount correction unit 508 to obtain the target air amount A / N0.

That is, A / N0 = A / Nv * Ka '(AT).

Where A / N0 is the corrected target air amount, A / Nv is the uncorrected target air amount, and Ka 'is the correction coefficient based on the intake air temperature (AT) (Fig. 38).

Hereinafter, the target air amount A / N0 output from the target air amount correction unit 508 is sent to the target throttle opening degree calculation unit 509,
The opening Θ1 of the main throttle valve THm and the opening Θ2 ′ of the auxiliary throttle valve THs with respect to the target air amount A / N0 are obtained by referring to the three-dimensional map in the figure. The opening Θ2 ′ of the sub-throttle valve THs is sent to the opening correction unit 510, and the opening ΔΘ corresponding to the amount of air passing through the bypass passages 52b and 52c shown in FIG. The opening Θ2 of the throttle valve THs is used.

By the way, the above-mentioned ΔΘ is obtained by the following equation. That is, ΔΘ = Ks (Θ) * {Sm + Sw (WT)} where the coefficient Ks (44th) is a step motor 52s controlled by an ISC (idle speed controller) not shown with the target opening Θ as a parameter. The opening correction amount per step of Sm, Sm is the number of steps of the step motor 52s, Sw (Fig. 45) is the opening of the wax valve 52W with the engine coolant temperature WT as a parameter, and the step motor 52s is converted into the number of steps It is the converted value.

By the way, the corrected target air amount A / N0 output from the target air amount correction unit 508 is sent to the subtraction unit 513 and the current air amount A / N detected by the airflow sensor at every predetermined sampling time. Is calculated as ΔA / N. This ΔA / N
Is sent to the PID control unit 514, PID control is performed based on ΔA / N, and the opening correction amount ΔΘ2 corresponding to ΔA / N is calculated. The opening correction amount ΔΘ2 is added to the target throttle opening Θ2 by the adder 51 to calculate the feedback-corrected target opening Θf at every predetermined sampling time.

Θf = Θ2 + ΔΘ2. Here, the opening correction amount ΔΘ is the opening correction amount ΔΘp by the proportional control, and the opening correction amount ΔΘ by the integral control.
i, the opening correction amount ΔΘd by the differential control is added. That is, ΔΘ = ΔΘp + ΔΘi + ΔΘd.

Where ΔΘp = Kp (Ne) * Kth (Ne) * ΔA / N ΔΘi = Ki (Ne) * Kth (Ne) * Σ (ΔA / N) ΔΘd = Kd (Ne) * Kt (Ne) * {ΔA / N-ΔA / Nold} is calculated by the PID control unit 514. here,
Kp, Ki, Kd are proportional, integral and differential gains with the engine speed Ne as a parameter, and their characteristic diagrams are shown in FIGS. 40 to 42. Kth is the ΔA / N → ΔΘ conversion gain (Fig. 43) with the engine speed Ne as a parameter,
ΔA / N is the deviation between the target air amount A / N0 and the measured current air amount A / N, and ΔA / Nold is the ΔA / N at the previous sampling timing.

The target opening Θf obtained as described above is sent to the motor drive circuit 52 as a sub-throttle valve opening signal Θs. The motor drive circuit 52 controls the rotation of the motor 52m so that the opening degree Θ2 of the sub-throttle valve THs detected by the sensor TPS2 becomes the opening degree corresponding to the opening degree signal Θs.

By the way, the larger driven wheel speed output from the high vehicle speed selection section 37 is subtracted from the wheel speed VFR of the drive wheel in the subtraction section 55. Further, the larger driven wheel speed output from the high vehicle speed selection section 37 is subtracted from the wheel speed VFL of the drive wheels in the subtraction section 56. Therefore, the outputs of the subtraction units 55 and 56 are underestimated to reduce the number of times the brake is used even during turning, and to reduce the slip of the drive wheels by reducing the engine torque.

The output of the subtractor 55 is multiplied by KB in the multiplier 57 (0 <
KB <1), the output of the subtraction unit 56 is multiplied by (1-KB) in the multiplication unit 58, and then added in the addition unit 59 to obtain the slip amount DVFR of the right driving wheel. At the same time, the output of the subtractor 56 is multiplied by KB in the multiplier 60, and the output of the subtractor 55 is (1-K
B) After being multiplied, it is added in the addition unit 62 to be the slip amount DV FL of the left drive wheel. The variable KB changes according to the elapsed time t from the start of the control of the traction control as shown in FIG. 13, and is set to "0.5" at the control start time of the traction control, and as the control of the traction control progresses. , Is set to approach "0.8". That is, when the slip of the drive wheels is reduced by the brake, at the time of starting the control, the brakes are simultaneously applied to both the wheels, and for example, an unpleasant steering wheel shock at the start of the brake control on the split road can be reduced. . On the other hand, the operation in the case where the brake control is continuously performed and the above KB becomes "0.8" will be described. In this case, when the slip occurs in only one drive wheel, the brake control is performed by recognizing that the slip also occurs in 20% of the one drive wheel in the other drive wheel. This is because if the brakes on the left and right drive wheels are completely independent, if only one of the drive wheels is braked and the rotation decreases, the differential drive wheel slips due to the action of the differential and the brake is applied. This is because it is not preferable to be repeated. The slip amount DVFR of the right drive wheel is differentiated in a differentiator 63 to calculate its temporal change amount, that is, the slip acceleration GFR, and the slip amount DVFL 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. Then, the slip acceleration GFR is sent to the brake fluid pressure change amount (ΔP) calculation section 65, and the brake fluid for suppressing the slip acceleration GFR is referred to by referring to a GFR (GFL) -ΔP conversion map shown in FIG. The pressure change amount ΔP is obtained.

Further, the change amount ΔP is ΔP− for calculating the opening time T of the inlet valve 17i when the switch S2 is opened, that is, when the start / end determination unit 50 determines that the control start condition is satisfied.
It is given to the T conversion unit 67. That is, the valve opening time T calculated by the ΔP-T converter 67 is set as the brake operation time FR of the right drive wheel WFR. Similarly, the slip acceleration GFL is sent to the brake fluid pressure change amount (ΔP) calculation unit 66, and the slip acceleration GFL is suppressed by referring to the GFR (GFL) -ΔP conversion map shown in FIG. The change amount ΔP of the brake fluid pressure is calculated. This change amount ΔP is
When the switch S3 is closed, that is, when the start / end determination unit 50 determines that the control start condition is satisfied, the ΔP-T conversion unit 68 that calculates the opening time T of the inlet valve 18i is provided. That is, the valve opening time T calculated by the ΔP-T conversion unit 68 is used as the braking operation time FL of the left driving wheel WFL. This prevents the left and right drive wheels WFR and WFL from causing more slip.

Incidentally, in FIG. 14, when the brake is applied at the time of turning, in order to strengthen the brake of the inner drive wheel,
The inner wheel side when turning is shown by a broken line a. In this way, when the vehicle is turning, the load is moved to the outer wheel side and the inner wheel side is more likely to slip. By making the change amount ΔP of the brake fluid pressure larger on the inner wheel side than on the outer wheel side, At times, it is possible to prevent the inner ring side from slipping.

In the above embodiment, feedback control is performed by PID control based on ΔA / N, and the target opening Θ2 is corrected by adding the auxiliary throttle valve opening correction amount ΔΘ2 to the feedback-corrected target opening Θf. The target position Θ2 is output to the motor drive circuit 52 and the throttle position sensor TP is output even if the feedback control based on ΔA / N is not performed.
The opening of the sub-throttle valve THs detected in S2 is set to the target opening Θ
The output of the throttle position sensor TPS2 may be feedback-controlled so that it becomes 2. further,
From the opening of the auxiliary throttle valve THs detected by the throttle position sensor TPS2, the auxiliary throttle valve opening correction amount ΔΘ2
Feedback control may be performed so that the detected value corrected by subtracting is equal to the target opening Θ2.

Although the acceleration slip prevention device is shown as the embodiment of the present invention, the present invention is not limited to the device,
The same can be applied as long as it controls the throttle valve.

Further, in the T / M friction correction unit 502, the target engine torque is calculated by <first T / M friction correction method>.
By calculating T3 and calculating the target engine torque T6 by the operation condition correcting unit 505 by <second method for correcting operation conditions>, the target engine torque is corrected according to the real-time oil temperature OT of T / M. At the same time, the target engine torque can be corrected by the elapsed time τ after the engine is started.

Further, in the T / M friction correction unit 502, the target engine torque T3 is set by the <second method of T / M friction correction>.
Is calculated, and the target engine torque T6 is calculated by the driving condition correction unit 505 according to the <second method for correcting engine driving conditions>.
By calculating, the target engine torque can be corrected in accordance with the engine coolant temperature WT in the warm-up state of T / M, and the target engine torque can also be corrected by the engine elapsed time τ.

Further, in the T / M friction correction unit 502, the target engine torque is calculated by the <T / M friction correction third method>.
T3 is calculated, and the target engine torque T6 is calculated by the operation condition correction unit 505 by the <engine operation condition correction second method>.
By calculating the warm-up state of T / M, the target engine torque is corrected based on the cooling water temperature WT0 immediately after the engine starts and the real-time cooling water temperature WT, and the target engine torque is also calculated by the elapsed time τ after the engine starts. Can be corrected.

As described above in detail, according to the present invention, in the vehicle engine output control method for controlling the throttle opening so that the engine output of the vehicle 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 after conversion, the opening of the other throttle valve is uniquely obtained from the map according to the one target throttle valve and the target air amount. It is possible to provide an engine output control method for a vehicle that can immediately obtain the opening degree of the other throttle valve even when the opening degree changes and realize highly accurate control.

[Brief description of drawings]

FIG. 1 (A) is an overall configuration diagram of an acceleration slip prevention device to which a control method according to the present invention is applied, FIG. 1 (B) is a diagram showing arrangements of main and sub throttle valves, and FIG. A) and (B) are block diagrams showing the control of the traction controller of 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 centripetal acceleration. Figure 5 shows the relationship between GY and the variable Kr. Fig. 5 shows centripetal acceleration.
FIG. 6 is a diagram showing the relationship between GY and slip correction amount Vg, FIG. 6 is a diagram showing the relationship between temporal change amount ΔGY of centripetal acceleration and slip correction amount Vd, and FIGS. FIG. 13 is a diagram showing a relationship with the variable Kv, FIG. 13 is a diagram showing a change with time of the variable KB from the start of the brake control, and FIG. 14 is a change amount GFR (GFL) of the slip amount with time and a change amount Δ of the brake fluid pressure.
Fig. 15 is a diagram showing the relation with P, Fig. 15 and Fig. 18 are diagrams showing the relation between the slip ratio S and the friction coefficient µ of the road surface, Fig. 16 is a diagram showing Tlim-t characteristics, and Fig. 17 is Tlim. -VB characteristic diagram, FIG. 19 is a diagram showing a state of the vehicle at the time of turning, FIG. 20 is a transition oil temperature OT-torque correction amount Tf characteristic diagram, FIG.
Fig. 21 is a characteristic diagram of XT-torque correction amount Tf, Fig. 22 is a characteristic diagram of time after starting τ-engine cooling water temperature WT, transmission oil temperature OT, and Fig. 23 is a rotational velocity N-torque correction amount Tf characteristic diagram, Fig. 23
Fig. 24 is a three-dimensional map showing the torque correction amount Tf with respect to the 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, and Fig. 26 is pump oil. FIG. 27 is a diagram showing the relationship between the temperature OP and the loss torque TL,
The figure shows the relationship between the battery voltage Vb and the loss torque TL, and FIG. 28 is a three-dimensional map showing the loss torque TL with respect to the engine rotation speed Ne and the exciting current iΦ of the alternator,
FIG. 29 shows the alternator efficiency K with respect to the exciting current iΦ, FIG. 30 shows the atmospheric pressure-torque correction amount Tp characteristic diagram, and FIG. 31 shows the engine cooling water temperature WT-torque correction amount TW characteristic diagram.
Fig. 2 shows the elapsed time after engine start τ-torque correction amount Tas characteristic diagram. Fig. 33 shows the engine oil temperature-torque correction amount Tj characteristic diagram.
Fig. 34 is a three-dimensional map showing the intake air amount A / Nm (mass) per engine revolution with respect to the target engine torque T7-engine speed Ne, and Fig. 35 is the engine speed Ne with the coefficient Ka.
Characteristic diagram, Fig. 36 shows the intake air temperature characteristic of coefficient Kt, Fig. 37
The figure shows the atmospheric pressure characteristic of the coefficient Kp, Fig. 38 shows the intake temperature characteristic of the coefficient Ka ', and Fig. 39 shows the target air amount A / N0-the auxiliary throttle valve THs with respect to the main throttle valve opening Θ1. A three-dimensional map showing the opening Θ2 ′, FIG. 40 is a diagram showing the engine speed characteristic of the proportional gain Kp, FIG. 41 is a diagram showing the engine speed characteristic of the integral gain Ki, and FIG. 42 is the differential gain Kd.
FIG. 43 is a diagram showing the engine speed characteristic of the engine, FIG. 43 is a diagram showing the engine speed characteristic of the conversion gain, and FIG. 44 is the target opening Θ.
FIG. 45 is a diagram showing the relationship with the coefficient Ks, and FIG. 45 is a diagram showing the engine cooling water temperature WT and the step number conversion value Sw. 11 to 14 …… Wheel speed sensor, 15 …… Traction controller, 45 …… TSn calculator, 45b, 46b …… Coefficient multiplier, 46
...... TPn calculation unit, 47 …… Reference torque calculation unit, 503 …… Engine torque calculation unit, 507 …… Target air amount calculation unit, 512 ……
Target throttle opening calculation unit, 53 ... Centripetal acceleration calculation unit,
54 Centripetal acceleration correction unit.

Claims (1)

(57) [Claims] 1. A main throttle valve whose opening is controlled according to an operation amount of an accelerator pedal and a sub-throttle valve whose opening is electrically controlled are provided in an intake passage of a vehicle engine, and the sub-throttle is provided. In the engine output control method for controlling the output of the engine by controlling the opening of the valve, a target engine torque to be output from the engine is calculated, and the target engine torque and the opening of the main throttle valve are calculated. Using the target throttle valve, the target opening degree of the sub-throttle valve required to output an engine torque equal to the target engine torque from the engine is obtained, and the sub-throttle valve is opened so that the sub-throttle valve opening degree becomes the target opening degree. A method for controlling an engine output of a vehicle, comprising controlling a valve.