JPH04166632A - Engine output control device - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine output control device that regulates engine output according to vehicle driving information.

(Prior Art) When an automobile is suddenly accelerated, slip occurs in the drive wheels, causing a phenomenon in which the engine output is not sufficiently transmitted to the road surface. Such slips frequently occur on slippery road surfaces. In order to prevent the occurrence of such slip, an engine output control device is known that reduces the engine output depending on the road surface condition to prevent the generation of slip in the driving wheels during acceleration.

In such an engine output control device.

As means for reducing the engine output, there are methods in which the opening degree of the throttle valve is controlled by a separate link system with priority over the accelerator link system, and methods in which the throttle valves are arranged in two stages, front and rear, on the intake path. Furthermore, fuel is cut to a predetermined cylinder among all the cylinders of the engine to control the cylinder, and ignition timing is delayed (retarded).
Efforts are being made to reduce engine output.

(Problem to be solved by the invention) However, when regulating the opening of the throttle valve, it is necessary to add a drive mechanism to drive the throttle valve, so it is necessary to partially change the engine hardware. This makes it difficult to reduce costs, and there is also the problem that air flow control using a throttle valve has poor responsiveness.

Furthermore, if engine output is reduced by simply increasing or decreasing the number of fuel-cut cylinders, the engine output will be reduced in stages, not continuously, and the actual output torque will be different from the required engine torque. There was a problem that deviations always remained.

An object of the present invention is to provide an engine output control device that can achieve the required engine torque on an average basis.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention includes a required engine torque calculation means for calculating required engine torque according to driving state information and traveling state information of the vehicle, and a fuel injection control means for injecting a predetermined amount of fuel into each cylinder of the engine; a torque deviation calculation means for calculating a torque deviation between the requested engine torque and the expected output torque to be fed back; a target engine torque calculation means for calculating a target engine torque by correcting the torque; an output torque calculation means for calculating a current output torque based on the intake air amount of the engine; and a difference between the target engine torque and the output torque. output regulation value calculation means for calculating a corresponding torque reduction amount and also calculating the number of fuel cut cylinders corresponding to the torque reduction amount; and an expected output for calculating the expected output torque of the engine driven with the fuel cut cylinder number. The present invention is characterized by comprising a torque calculation means and an engine output control means for controlling the fuel injection control means in accordance with the number of fuel cut cylinders.

(Function) The torque deviation calculation means calculates a torque deviation between the required engine torque and the expected output torque that is fed back, and the target engine torque calculation means corrects the required engine torque based on the torque deviation to calculate a target engine torque. The output regulation value calculation means calculates the torque reduction amount according to the difference between the target engine torque and the current output torque from the output torque calculation means, and also calculates the number of fuel cut cylinders according to the torque reduction amount, so that the engine output The control means can drive and control the fuel injection control means based on the calculated number of fuel cut cylinders.

(Embodiment) The engine output control device shown in FIG. 1 is installed in a front* drive vehicle. This engine output control device includes an engine controller (ECI controller) 16 that controls the fuel supply system 1 of the engine 10 and an ignition system, and a traction controller 1 that calculates a target output value according to various driving information of the vehicle.
5, which work together to control the engine 10.

Here, the engine 10 outputs air-fuel ratio (A/F) information obtained from the air-fuel ratio sensor 2 disposed in the exhaust path 1 to the engine controller 16, and the controller 16 outputs the air-fuel ratio (A/F) information obtained from the air-fuel ratio sensor 2 disposed in the exhaust path 1. A configuration is adopted in which the amount of fuel to be supplied is calculated, the injection nozzle 3 injects and supplies the amount of fuel to the intake passage 4 in a timely manner, and the ignition plug 22 is ignited through the ignition circuit 23 in a timely manner.

The intake passage 4 of the engine 10 consists of an air cleaner 5 and an intake pipe 6, and a throttle valve 7 is disposed in the middle thereof. The throttle valve 7 shows load information.

The vehicle is provided with left and right front wheels WFL and WFR as driving wheels, and left and right rear wheels WRL and WRR as driven wheels. These left and right front wheels WFL and VFR are the wheel speed V of the left and right front wheels.
Wheel speed sensors 11 and 12 that output FL and VFR are provided opposite to each other, and the left and right rear wheels WRL and WRR have wheel speed sensors 13 and 12 that output axle speeds VRL and VRR of the left and right rear wheels, respectively.
14 are arranged opposite each other.

Each of these wheel speed information is transmitted to the traction controller 15.
is input.

In addition, the traction controller 15 is connected to a throttle sensor 8 for emitting throttle opening information, an air flow sensor 9 for emitting intake air amount information, and a crank angle sensor 20 for emitting a unit crank angle signal and engine rotation speed Ne information from that signal. has been done. Furthermore, this traction controller 15 can output a target engine torque T0, which will be described later, to the engine controller 16, and can also output data from each sensor.

On the other hand, data from each sensor via the traction controller 15 is input to the engine controller 16, and the air-fuel ratio (A/
F) Information is entered. Furthermore, a water temperature sensor 19 that emits engine coolant temperature information, an intake air temperature sensor 17 that emits intake air temperature information, an atmospheric pressure sensor 18 that emits atmospheric pressure information,
A knock sensor 21 that generates knock information about the engine 10 is connected.

The main parts of the traction controller 15 and the engine controller 16 are each made up of a microcomputer, and in particular, the traction controller 15 calculates the required engine torque T according to the required engine torque calculation program shown in FIG.

and outputs the value to the engine controller 16. The engine controller calculates control values according to the control programs shown in FIGS. 10 to 13.

The injection nozzles 15 of the cylinders other than the fuel cut cylinder are driven to achieve a predetermined injection amount at a proper time.

Here, the functions of the traction controller 15 and engine controller 16 will be explained with reference to FIG. 2.

Here, the traction controller 15 has a function as a required engine torque calculation means, and calculates the required engine torque To according to the driving state information and traveling state information of the vehicle.

The engine controller 16 includes a torque deviation calculation means,
It has functions as a target engine torque calculation means, an output torque calculation means, an output regulation value calculation means, and an engine output control means.

Here, the torque deviation calculation means calculates the required engine torque 'f
Expected output torque T o fed back with tag
ut, the target engine torque calculation means corrects the requested engine torque T refo based on the torque deviation Tterr to calculate the target engine torque T tag, and the output torque calculation means calculates the target engine torque T tag.
The current output torque T e based on the intake air amount A/N of o
xp, the output regulation value calculation means calculates the torque reduction amount according to the difference between the target engine torque T tag and the above output torque Texp, and calculates the number of fuel cut cylinders Nfc according to the torque reduction amount, and calculates the prediction. Engine 1 whose output torque calculation means is driven with the number of fuel cut cylinders Nfc
0 is calculated, and the engine output control means controls the fuel injection control means according to the number of fuel cut cylinders Nfc.

In particular, here, the output regulation value calculation means calculates the ignition retard amount as well as the number of fuel cut cylinders Nfc corresponding to the torque reduction amount, and the expected output torque calculation means calculates the ignition retard amount of the engine 10 driven by the fuel cut number of cylinders and the ignition retard amount. The expected output torque T3 is calculated, and the engine output control means controls the fuel injection control means and also controls the ignition control means according to the ignition retard amount.

Here, the control processing by the traction controller 15 and the engine controller 16 will be explained along with the control programs shown in FIGS. 9 to 13.

The traction controller 15 performs a main routine (not shown) to determine failures of each sensor and circuit.

Initial settings are performed by setting initial values in each area, and the output of each sensor is received and set in each area, and other processing is performed. A required engine torque calculation routine is entered at each predetermined interrupt timing (time interrupt) during that time.

Here, each data is received from each wheel speed sensor and stored at predetermined addresses v□, vFL, vll, vlL.

In step a2, the vehicle body speed Vc is determined from the average wheel speed of the left and right wheels between the valves and is stored. Furthermore, the longitudinal acceleration ac is calculated by differentiating the vehicle speed Vc. Then, at the peak value acMAχ of this longitudinal acceleration ac, the theory (μ
mS characteristic, ) represents the maximum friction coefficient of the road surface, so the peak value of this longitudinal acceleration acM
Set A as the estimated value of the friction coefficient of the road surface. Then, find the slip ratio S at that point. Then, a target wheel speed V is calculated by adding a wheel speed coal equivalent to the slip ratio S. When step a6 is reached, the target wheel speed Vw is differentiated to calculate the target wheel acceleration Vv/dt.

In step a7, the driving wheel torque to achieve the target wheel speed VW is determined based on the target wheel acceleration Vv/dt and according to the vehicle weight W and the tire radius R1 and the running resistance.
w is determined, and the required engine torque TO is calculated by considering the drive wheel torque Tw and the transmission gear ratio, and is output to the engine controller 16.

Engine controller 16 is activated by key-on.

Start the ECI main routine.

Here, first, initial settings (not shown) are made, and the detection data of each sensor is read and taken into a predetermined area.

In step b2, whether or not the fuel cut zone is reached is determined based on the engine speed Ne and the engine load information (in this case, the intake air amount A/
N) is determined, and in the case of a cut, the process proceeds to step b3, where the air-fuel ratio feedback flag FBF is cleared, the fuel cut flag FCF is set to 1, and the process proceeds to step blo.

When it is determined that the fuel is not cut and step b5 is reached, the fuel cut flag FCF is cleared and it is determined whether the well-known air-fuel ratio feedback condition is satisfied. If the condition is not satisfied, for example, in a transient operating range such as a power operating range, the process directly proceeds to step b9.

When the air-fuel ratio feedback condition is satisfied and step b7 is reached, the correction value K corresponding to the normal feedback control constant is determined based on the output of the air-fuel ratio sensor 2.
Calculate FB.

Then, this value is taken into address KAF and step b9
Proceed to.

In step b9, other fuel injection pulse width correction coefficients K
DT and a correction value TD for the dead time of the fuel injection valve are set according to the operating condition, and a correction value for calculating the ignition angle ψ, which will be described later, is calculated and the process proceeds to step bll. Here, the ignition angle ψ is set. The correction values for this calculation include a water temperature correction value Wψ that is advanced in response to a decrease in water temperature, an atmospheric pressure correction value Pψ that is advanced in response to a decrease in atmospheric pressure, and a predetermined retard amount that is advanced in accordance with knock information. A knock correction value Nψ to be added and a battery voltage correction value Bψ to which a predetermined amount of retard is added according to a battery voltage drop are calculated based on each sensor output and stored in a predetermined area.

In step blo, the dwell angle is set based on a predetermined map (an example of which is shown in a characteristic diagram in FIG. 8) so that the dwell angle increases in accordance with the engine speed Ne.

Thereafter, the routine proceeds to step bll, an engine output regulation routine, and thereafter returns to step b1.

In this engine 8 force regulation routine, as shown in FIG. 11, in step c1, the target torque feedback correction amount Tcor (the previous value is fed back) is determined, and the required engine torque TrefO is added to this to obtain the target engine torque Ttag. (= Trefo+Tco
r).

In this case, the previously calculated expected output torque Tout (reduction amount) is taken in.

Note that this value was calculated using equation (1). The formula for calculating the expected output torque T out is such that the power torque is calculated to be lower by the amount of reduction depending on the number of cylinders in the body and the amount of ignition retard.

Tout=TfclXNfc-b-Tret
(1) Here, Tfcl is the output torque change amount per cylinder, Nfc is the number of cut cylinders, and a and b are interpolated from a map that takes into account the coefficient C cylinder), Tret ignition control (retard control) shows the amount of torque reduction due to Of these,
Tret is calculated using equation (2).

Tret= (θadv-θadvo-θrto)/
Kret/6XNfc...(2) where θadv is the final ignition angle, θadvo is the ignition angle without traction control correction, and Kr5t is the retard gain (
A/N and rotation speed map), θrto indicates the invalid retard amount (A/N and rotation speed map).

Next, the torque deviation Terr is calculated from equation (3).

Note that the formula for the torque deviation T err is a formula that indicates the difference between the required engine torque T refo and the expected output torque Tout.

Terr=Trefo-Toutl (3) Here, the feedback (previously calculated) expected output torque Tout is subtracted from the required engine torque T refO.

Next, from equation (4), the target torque feedback correction amount T
Calculate cor. The formula for the target torque feedback correction amount T cor performs a PI calculation on the torque deviation T err, and delays the phase around the required engine torque Trefo so that the torque deviation T err swings in positive and negative directions. As a result, the average value is always maintained within a narrow range that includes the target torque feedback correction amount Tcor.

Tcor=TerrXKp+(Terr+5err)X
K1''・(4) Here, T err is calculated from equation (3). Furthermore, the integral term of the deviation (Serr←5err + Ter
r), KP, and Kl are control gains (tentative value Kp=0
．． 2, Kl=0°01).

Furthermore, the intake air amount A/N is calculated, and then the current output torque Tn corresponding to the intake air amount A/N is estimated. In this case, the output torque T is determined in advance based on the intake air amount A/N.
Map for calculating exp (an example is shown in Figure 4)
From this, the current output torque T exp is calculated. and,
Target engine torque T tag and current output torque T
A necessary torque reduction amount Trtd, which is the difference between exp, is calculated. Then, the number of fuel cut cylinders Nc and the ignition angle ψ corresponding to the required torque reduction amount are calculated according to a predetermined map set in advance, and the process proceeds to step c2.

In step c2, the target ignition angle φ is set. Calculate. Here, a water temperature correction value Wψ is advanced in response to a decrease in water temperature, an atmospheric pressure correction value Pψ is advanced in response to a decrease in atmospheric pressure, and a knock correction value Nψ is added to a predetermined retard amount in accordance with knock information. and a battery voltage correction value Bφ that adds a predetermined amount of retard according to the battery voltage drop, and correct the map ignition angle ψ using these correction values to obtain the target ignition angle φ.

Calculate.

After this, when reaching step C4, a cut cylinder number is determined based on a map as shown in FIG. 6 according to the number of body cylinder cuts.

The map in Figure 6 is based on the structure of the engine 10 (in this case, it is a V type 6 cylinder as shown in Figure 5), characteristics, rotational balance, cooling efficiency, etc., and the cylinder number is determined according to the number of cuts. is set.

After this, in step c5, the determined number of fuel cut cylinders N
Equations (1) and (2) above are calculated from c and the ignition angle ψ, thereby obtaining the expected output torque T out and the torque reduction amount Tret, in preparation for the calculation of the next target torque feedback correction amount Tcor.

When the cylinder number corresponding to the number of cuts is set in this way, the process proceeds to step c6. Here, whether or not it is in the lean range is determined based on the engine rotation speed Ne and engine load information (intake air amount A/N here). Judgment is made based on the driving range map shown in Figure 7. In the lean region, it returns as it is. At the time of a transient operating range that is not a lean range, such as a power operating range with a high slip ratio, the current operating information (A/N,
An air-fuel ratio correction coefficient KMAP corresponding to N e ) is calculated from a predetermined map, this value is input to address KAF, and the process returns to the main routine.

During this ECI main routine, the injector driving routine shown in FIG. 12 and the ignition driving routine shown in FIG. 13 are performed.

The injector drive routine reaches steps d1 and 2 at a predetermined crank pulse interrupt, takes in the intake air amount A/N and engine rotation speed Ne, returns when the fuel cut flag FCF is 1, and proceeds to step d4 when the fuel cut flag FCF is 1. Then, the basic fuel pulse width T1 is set, and the main pulse width data Tinj=T.

Calculate XKAFXKDT+TD and proceed to step d'6.

Here, set Tinj to the driver for the uncut cylinder among the injector drive drivers, trigger the driver, and the injection nozzle 3 injects fuel.
Return. This process reduces the output for the cut cylinders.

On the other hand, when step e1 is reached due to a crank pulse interrupt, the dwell angle is set in a dwell angle counter that allows the primary current to flow by the dwell angle, which is the primary current energizing crank angle cap here. In step e2, the ignition signal is set to the target ignition angle ψ. The target ignition angle ψ can be output to the ignition timing counter. is set.

As a result, each counter drives the ignition circuit when counting a predetermined crank pulse, causing the ignition plug 22 to ignite. In this ignition process, the target ignition angle ψ. The output can be reduced by the amount of retard included in the output with good responsiveness.

(Effects of the Invention) As described above, the present invention calculates the torque deviation between the requested engine torque and the expected output torque that is fed back, corrects the requested engine torque based on the torque deviation, calculates the target engine torque, and calculates the target engine torque. Since the torque reduction amount is calculated according to the difference between the torque and the current output torque from the torque calculation means, and the number of fuel cut cylinders is calculated according to the torque reduction amount, the engine is operated with the calculated fuel cut cylinder number. Since the engine is driven, it is possible to achieve an output reduction according to the stopped cylinders and an output reduction according to the calculated ignition retard, and in particular, it is possible to achieve the required engine torque on average based on the feedback of the expected output torque.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of an engine output control device as an embodiment of the present invention, FIG. 2 is a block diagram of a control means of the same device, and FIG. 3 is a slip ratio of a vehicle equipped with the above device. -Friction coefficient characteristic diagram. Fig. 4 is an explanatory diagram of the output torque calculation map used in the above device, Fig. 5 is a schematic plan view of the engine of a vehicle equipped with the above device, and Fig. 6 is an explanation of the cylinder number setting map used in the above device. Figure 7 is an explanatory diagram of the driving range calculation map used in the above device, Figure 8 is an explanatory diagram of each dwell Saro map used in the same device, and Figure 9 is an explanatory diagram of the target engine torque calculated by the traction controller used in the same device. Flowchart of calculation program. FIGS. 10 to 13 are flowcharts of each control program executed by the engine controller used in the above device. 2... Air-fuel ratio sensor, 3... Injection nozzle, 7...
Throttle valve, 8...throttle position sensor,
9... Air flow sensor, 10... Engine, 1.
1, 12, 13, 14...Wheel speed sensor, 15...ψ
Traction controller, 16... Engine controller, 22... Spark plug, V F l l V
F c gV Ill m, , V 31 L...
Wheel speed, Ttag...Target engine torque, To
ut... Expected output torque, ψ. ...Target ignition angle, A
/F...Air-fuel ratio, ÷4 Fig. %4V Fig.b Fig. (Maekatsu'J) Horse 7 Keigai 6 Mouth Nε Horse/θ Fig.

Claims (1)

[Claims] Request engine torque calculation means for calculating a request engine torque according to driving state information and driving state information of the vehicle;
a fuel injection control means for injecting a predetermined amount of fuel into each cylinder of the engine of the vehicle; a torque deviation calculation means for calculating a torque deviation between the requested engine torque and the expected output torque fed back; a target engine torque calculation means for calculating a target engine torque by correcting the required engine torque; an output torque calculation means for calculating a current output torque based on the intake air amount of the engine; and the target engine torque and the output torque. an output regulation value calculation means for calculating a torque reduction amount according to the difference between the two and a number of fuel cut cylinders according to the torque reduction amount; and calculating the expected output torque of the engine driven with the fuel cut number of cylinders. An engine output control device comprising: an expected output torque calculation means for calculating the fuel injection; and an engine output control means for controlling the fuel injection control means according to the number of fuel cut cylinders.