JPH0326838A - Controller for engine for vehicle - Google Patents

Abstract

PURPOSE:To supply each proper quantity of air and fuel for an aimed torque by applying each phase compensation in relation to the air quantity and fuel quantity onto the aimed torque so that the transmission characteristic accords with the previously determined characteristic of a standard model. CONSTITUTION:A calculating means 23 calculates the aimed torque T1 demanded by an engine according to the output of an accelerator operating quantity sensor 31. Phase compensating means 34 and 36 apply each phase compensation in relation to the air quantity and fuel quantity onto the aimed torque T1 so that the transmission characteristics of the inside-cylinder intake air quantity and the fuel quantity onto the aimed torque T1 accord. to those in a standard model set by a setting means 33. An air quantity control means 35 controls the throttle valve opening degree and a fuel feed quantity control means 37 controls the fuel feed quantity on the basis of each aimed torque which is phase-compensated. Thus, the air quantity and fuel quantity which are inhaled into the cylinder can be supplied in each proper quantity for the aimed torque.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control device for a single engine that controls a throttle valve by servo control.

(Joubei technology) The mainstream of Joubei's vehicle engine control devices was a method that detected the amount of intake air and injected fuel according to this amount of air (air amount-driven method); It is not possible to supply the optimum amount of fuel in response to the constantly changing idle conditions during transient operating conditions.

Therefore, for example, JP-A-56-10792
As in Publication No. 5, a method (fuel amount-driven method) has been proposed in which the fuel flow rate is determined with priority based on the amount of accelerator operation, and the amount of incoming air is controlled dependently according to this fuel flow rate. (Problems to be Solved by the Invention) By the way, 5. Such an air mass-driven system or a fuel I-driven system can only control the air volume or the phase of the single force of the fuel bar.
Second, during a transient period, it is difficult to supply just the right amount of air and fuel to the intake stroke of each cylinder.3 For example, regarding the amount of intake air (. There is a response delay i1. due to the fuel amount l, and a fuel supply delay #1 due to the wall flow.The degree of delay is different between the two.Therefore, when there is a difference, However, the actual torque transmission characteristics relative to the target 1 torque fluctuates greatly, so the desired characteristic of the actual torque is 1±. When controlling, it is difficult to design a control system.6 This invention focuses on these unresolved problems, and is based on the following:
A desirable and practical standard Il model is set in advance as the response characteristic of the actual torque to the target torque of 1, and the intake air amount and the transfer characteristics of the fuel supply are matched to it.
11. Apply phase compensation to each of the target torques (11) and 11. The purpose of this project is to provide a device that independently controls the X-rottle valve pitch and the fuel supply amount so that a visually detectable torque can be obtained.

(Solving the R problem?, second method) This Q llJf I. f: As shown in FIG. Hand 3 to calculate the target torque T1
2, a means 33 for predetermining a reference model showing the transfer characteristics of the actual torque of 4 to the estimated torque; and 20 presetting! 'L zo, - the target torque T+i in the standard model del
．． : The transmission characteristics of the intake air amount in the cylinder corresponding to the illusion '1'' are the same, 6J:-) and the 'J'-stage 34 which performs phase compensation on the air amount to the target torque] '1; The means 35 for controlling the zero intake air amount to the engine in accordance with the phase-compensated target torque and the transmission characteristic of the intake fuel amount in the engine with respect to the target torque T! match the reference model also set in advance. The target torque T'll is set so that
．． ::The means 3δ for performing phase compensation regarding the amount of fuel and the means 37 for controlling the fuel supply to the engine according to the target torque to which this phase compensation has been applied are eliminated.

(Function) The response characteristics of the amount of air sucked into the cylinder and the fuel breakdown during a transient period {normally ~ does not occur.

:In contrast, this invention is 1! ′, a reference model has been established in advance to uniformly handle the different response characteristics of each control system for intake air and fuel supply, and a reference model has been established in advance to uniformly handle the different response characteristics of each control system for intake air and fuel supply. Phase compensation is applied to each target torque T1 separately so that the transmission characteristics match this reference model. Due to this separate phase compensation, the amount of air and fuel that can obtain the 1 J standard torque are supplied to the shilling in just the right amount and the amount of fuel.

(Embodiment) In FIG. 2, 1 is a crank angle sensor which outputs a signal for each reference position such as M'9 for each unit angle.

Reference numeral 2 denotes an accelerator opening sensor that detects the accelerator leap (accelerator operation ffi) Ace based on the output voltage of the potentiometer a.

The CPU 6, which receives the detection signals from the sensors 1 and 2, uses the fuel that requires 1τ to reduce the output torque as shown in Figure 3. The injection amount (fuel supply amount) is determined, and a fuel injection pulse with a pulse width corresponding to this is output to the innojector 10 installed in the engine's intake passage (for example, each intake ball) to inject the fuel. Perform supply control. In addition, a target throttle valve opening that provides the amount of intake air required to output one standard torque is determined, and this is output to the servo drive circuit 12 to control the amount of air. Reference numeral 7 denotes a ROM that stores various data (for example, a fuel injection amount table 8 and a throttle valve 11M degree table 9 shown in the figure) necessary for calculation of the CPUG.

The servo drive circuit 12 outputs the actual throttle/throttle valve jump degree θR detected by the throttle sensor 23 (which detects the opening degree of the throttle valve 22 installed in the intake passage 21) from the CPU 6. x throttle '#22 according to the deviation of both opening degrees so that it matches the target throttle valve leap degree θ0.
The servo moke 24 connected to the motor is driven in forward and reverse directions.

FIG. 3 shows the control operation performed by the CPU 6, and the control operation in the figure is executed every fixed period M (for example, every 4 msec).

In P1 and P2, accelerator opening ACc and engine speed N
Load e. Note that Ne is calculated based on the signal from the crank angle sensor 1. At P3, the actual throttle valve opening θR is read.

At P4, the target torque T1 is calculated. T1 is the engine output torque required for the vehicle driving condition at that time, and is given according to the vehicle driving condition. Note that if there is no need to change the characteristics depending on the driving conditions of the vehicle, the fourth
It may be determined by lookup or the like from Acc and Ne according to the characteristics set in a torque table as shown in the figure.

The reason why Ne is used as a parameter when calculating T1 is because if the accelerator opening is kept constant and the rotation speed is increased, the torque will decrease when the rotation speed exceeds a predetermined number. This is to correct the torque so that it does not decrease even in the above range. Therefore, if the engine is used in a rotation range where the torque does not decrease, it is sufficient to calculate TI based only on Acc.

P5 to P7 are parts that perform phase compensation on the air amount from a delay element corresponding to a reference model of TI and a correction element for response delay of intake air, and function as the phase compensation means 34 in FIG. It is a part.

In P5, the time constant τF of collector filling is calculated. τF
is a value representing the response characteristic when intake air fills the collector of the intake system. Since τF is determined by θR and Ne, the data of τF is calculated in advance and given in a table, and read from θR and Ne at that time.

Note that the calculation formula for τF is shown for reference.

τr = (Vc/R-TA)X1/(η
v・■E・γA・Ne/ 2 PA0C−g' θR)
...■ However, in the formula ■, Vc is the collector volume, R is the gas constant, T^ is the intake air temperature, PA is the atmospheric pressure, ηV is the charging efficiency, ■E is the engine wandering amount, γA is the air density, C is the opening constant of the throttle valve, and g is a constant determined by the intake pipe pressure.

In P6, delay compensation corresponding to the standard model is applied to T. give to
Find the target torque T2. For example, if the reference model is set as a first-order lag with a time constant τR, then the sample period T
The calculation is performed using the following recurrence formula, which is made into a discrete value by o(4 iasec).

T2new=KR-T2old+(1-KR)
・T 1-■K R= exp(-T o/τR
) ・=■ However, in the formula ■, T
rnewJ and "Od" attached to 2 mean the current and previous T2, respectively. This code will be used later. Further, KR and 1-KR are weighting coefficients.

The predetermined reference model represents the transfer characteristic of the actual torque with respect to the target torque, and a desirable and achievable value is selected for the τ scale. In this example, the τ scale is given as a constant, but the value tRl varies depending on the operating condition.
It is also possible to set l r R2 (however, T R+<τR2). For example, as shown in Fig. 7, the response characteristics of the torque torque can be made gentler when the vehicle is at high speed by switching according to the vehicle speed, or as shown in Fig. 8, the response characteristics of the torque can be made gentler during turns. It is to make it.

At P7, a correction compensation for the response delay of the intake air is further applied to T2 to obtain the target torque T3.

For example, the delay element (transfer function) of intake air is τF
It is expressed as 1/(fFS +1) using (τ
Fs +1 )/(τAS+1) is used as the correction factor. In other words, the overall transfer function in this case is given by the following equation.

{1/(τps+1>IXII/(τ.s+1)
1×{(τFS+1)/(τAS 11)1=17(
τRS +1 ) (τAS + 1 > However, τ. is a value introduced for order matching, and in order to avoid the influence of this correction element, τA<CrF.

Here, too, T3 is calculated using the following recurrence formula obtained by discretization with the sampling period To.

T3new=KA-T3o1d+(1-KA)
” T I -■KA=(1-τF/τA) ・exp
(-T o/τA)...■ In P8, the target throttle valve opening θ0 is determined by referring to the target throttle valve opening table shown in the fiS5 diagram from T3 obtained by formula ■ and Ne at that time. Read out. The data given in Figure 5 is determined from the performance of the engine installed on the vehicle.

At P9, θ0 is output to the servo drive circuit 12. As a result, the throttle valve 22 is driven by the servo motor 24, and feedback control is performed so that its opening degree matches 00.

Here, from the servo drive circuit 12, the servo motor 24, the throttle valve 22, and the throttle sensor 23 shown in FIG.
functions are fulfilled.

I) 1 In 0, it is determined whether there is a cylinder at the timing to start injection at the present time, and if there is a cylinder A to start injection, proceed to l) 1 1 to P14, and if there is no cylinder to start injection. ends this routine.

In Pll, correction compensation for wall flow response delay is applied to T2 to obtain target torque T4. The method of amendment is the patent application 1986.
The following calculation is performed using the same method as shown in No. 3-123689.

T 4= (T 2-β・MF CYL)/α
...■MF CYL= (1-α)・Ti+(
1-β)・M F CYL ”・■Here, α and β are values for fuel correction regarding the perfect flow fraction M F CYL, and are predetermined as engine properties, and are based on engine temperature, rotation speed, and @inlet air. It takes a different value depending on the amount.For this reason, it may be read from a data table stored in advance in ROM based on engine cooling water temperature, Ne, and target torque (corresponding to intake air amount) T1, or vfM
It can also be calculated from the air-fuel ratio response as in No. 123689. Note that MF cy+- is calculated for each cylinder.

Here, P5, Pf3 and I) 11 are parts that compensate the phase of TI with respect to the fuel amount from the delay element corresponding to the reference model and the correction element for response delay due to wall flow, and the phase shown in Fig. 1 is The function of the compensation means 3G is fulfilled.

At P12, the basic injection pulse width TI3 is read out from the fuel injection amount table shown in FIG. 6 based on T4 obtained by formula (2) and Ne at that time. The data here is also determined from the performance of the drag engine installed in the vehicle.

In P13, various corrections (increase correction according to cooling water temperature, increase correction at startup, air-fuel ratio feedback correction based on the detected value of acidity concentration in exhaust gas, etc.) are made to T I) depending on the engine operating state. (known method) to calculate the fuel injection pulse width Ti.

P141? sets Ti to the CPU6 (7) output port. As a result, a fuel injection pulse having a pulse width of Ti is outputted to the injector 10 when a predetermined crank angle is reached, and an amount of fuel corresponding to Ti is injected and supplied to the intake bow 1.

Here, 82 functions of the fuel supply amount control means 37 in FIG. 1 are performed from P12 to P14 and the innojector 10 in FIG. 2.

Here, the operation of this example will be explained.

During transients (for example, during acceleration), the intake air first fills the 8' collector installed in the intake system, and then fills the 8' collector (7).
f& divided into shillings each. On the other hand, during acceleration, part of the injected fuel increased by the Innoecta 10 is taken away by the increased wall flow, and the rest, along with the already existing wall flow, goes into the cylinder where it was injected. and inflow. In this way, the amount of air and fuel introduced into one shilling has a response delay based on the shape of the intake pipe, the installation position of the injector, and the properties of each fluid. The response characteristics of both air quantity and fuel quantity usually do not match.

On the other hand, according to this example, (・
A reference model is set in advance as follows, and so that the transmission characteristics of the intake air amount in the cylinder and the amount of intake fuel in the cylinder with respect to the target torque both match this reference model, Phase compensation is X[
6 This amount of air. ! : By separate phase compensation regarding the amount of fuel, the amount of air and fuel that can be obtained at a line level of 1 lux are supplied in each shilling in just the right amount. In other words, different response delays occur for different reasons before the amount of air taken in through the air cleaner and the amount of fuel injected from the Innoecta 10 reach the shilling, and there is a difference in the amount of air and fuel that can obtain the target torque. Even if there is an excess or deficiency, the actual torque obtained from the amount of air and fuel sucked into the cylinder will match the target value. Furthermore, since the response characteristic of the actual torque to the target torque is determined to be one, it becomes easier to design the control system when controlling the response characteristic of the actual torque to the accelerator opening.

(Effects of the Invention) The present invention provides a phase-shifting method for the target torque with respect to the air amount and the fuel amount, so that the transfer characteristics of the intake air amount in the Schilling and the intake fuel amount in the Schilling with respect to the target torque match a predetermined reference model. Since the throttle valve opening degree and fuel supply amount are controlled so that each phase-compensated target torque can be obtained, the amount of air and fuel entering the cylinder can be adjusted to obtain the target torque. Not only can it supply just the right amount of torque, but it also allows for easy control system design when controlling the response characteristics of actual torque to accelerator opening.

[Brief explanation of drawings]

Fig. 1 is a diagram corresponding to the claims of this invention, Fig. 2 is a block diagram of a control system of an embodiment of this invention, Fig. 3 is a flowchart for explaining the control operation of this embodiment, and Figs.
FIG. 6 is a characteristic diagram showing the contents of the table used in the control operation, and FIGS. 7 and 8 are characteristic diagrams of τR of other embodiments. 1... Crank angle sensor, 2... Accelerator opening sensor, 6... CPU, 10... Injector, 7...
ROM, 12... Servo drive circuit, 22... Throttle valve, 23... Torque sensor, 24... Servo motor, 31... Accelerator operation amount sensor, 32...
...Target torque calculating means, 33... Normative model setting means, 34... Phase compensation means, 35... Air amount control means, 36... Phase compensation means, 37... Fuel supply amount control means .

Claims (1)

[Claims] A sensor for detecting the accelerator operation amount, a means for calculating the target torque required of the engine at that time based on the detected value of the accelerator operation amount, and a reference model showing the transmission characteristics of the actual torque with respect to this target torque are prepared in advance. means for setting the target torque, means for performing phase compensation regarding the air amount on the target torque so that the transfer characteristic of the intake air amount in the cylinder with respect to the target torque matches the preset reference model; means for controlling the intake air amount to the engine in accordance with the target torque set in advance; 1. A control device for a vehicle engine, comprising: means for performing phase compensation; and means for controlling the amount of fuel supplied to the engine in accordance with the phase-compensated target torque.