JP2606440B2 - Engine output control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an engine output control device that regulates the output of an engine in accordance with driving information of a vehicle.

(Prior art) When a car is suddenly accelerated, a slip occurs on the drive wheels,
A phenomenon occurs in which the engine output is not sufficiently transmitted to the road surface. Such a slip frequently occurs on a slippery road surface. In order to prevent the occurrence of such a slip, there is known an engine output control device that reduces the engine output in accordance with the condition of a road surface to prevent the occurrence of a slip of a drive wheel during acceleration.

In such an engine output control device, as a means for reducing the engine output, a throttle valve opening is controlled by another link system in preference to an accelerator link system, or a throttle valve is moved back and forth on the intake passage. Some are arranged in tiers. Further, a cylinder cut-off control by performing a fuel cut, a lean air-fuel ratio, and a delay (retard) of the ignition timing are performed to reduce the engine output.

(Problems to be solved by the invention) However, when regulating the opening of the throttle valve,
Since it is necessary to add a drive mechanism for driving the throttle valve, it is necessary to partially change the hardware of the engine, which makes it difficult to reduce the cost. There was a problem.

Further, when the engine output reduction control is performed only by the cylinder deactivation control, there is a problem that the engine output is not continuously reduced and the control feels strange. For this reason, it has been desired that the engine output reduction control according to the driving state of the vehicle be performed more accurately and without any discomfort.

An object of the present invention is to provide an engine output control device that can perform engine output control more accurately and without a sense of incongruity.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an engine speed detecting means for detecting an engine speed, and an intake air amount detecting means for detecting an intake air amount of the engine. An ignition timing setting means for setting an ignition timing of the engine; an air-fuel ratio control means for setting an air-fuel ratio of the engine; and a number-of-cylinders setting means for setting the number of cylinders to be closed among the engines. A target engine torque calculating means for calculating a target engine torque according to a running state of the vehicle, a plurality of target engine torques being set for each of the target engine torques;
A map in which the ignition timing, the air-fuel ratio, and the number of cylinders are stored in advance as one output control group, using the engine speed and the intake air amount as parameters, and the target engine torque and the engine speed are provided. And a predetermined output control group is selected according to the intake air amount, and the output of the engine is controlled based on the selected output control group.

Further, in the engine output control device according to the first aspect, when the target engine torque is between the plurality of maps, a predetermined output control group is selected by interpolation processing.

Further, in the engine output control device according to the first aspect, the number of cylinders to be stopped in the selected output control group is corrected based on the current engine speed or the engine speed change rate.

(Operation) The engine output control device calculates the target engine torque according to the running state of the vehicle by the target engine torque calculating means, and then sets a plurality of target engine torques for each of the target engine torques. Using a map in which the ignition timing, the air-fuel ratio, and the number of cylinders are stored in advance as one output control group with the parameters as parameters, the target engine torque, the current engine speed, and the intake air amount according to the running state of the vehicle are used. Select a predetermined output control group according to
The output of the engine is controlled based on the selected output control group. Therefore, the calculation of the predetermined output control group can be simplified using the map.

In particular, when the target engine torque is between the plurality of maps, the number of maps may be reduced by selecting a predetermined output control group by interpolation processing.

In particular, it is also possible to correct the number of cylinders in the selected output control group based on the current engine speed or the rate of change of the engine speed so that the number of cylinders to be stopped in accordance with the engine state is adjusted.

(Embodiment) The engine output control device of FIG. 1 is mounted on a front wheel drive vehicle. This engine output control device is an engine controller that controls a fuel supply system and an ignition system of the engine E.
16 and a traction controller 15 for calculating a target output value according to various driving information of the vehicle.

Here, the engine 10 outputs air-fuel ratio (A / F) information obtained from an air-fuel ratio sensor 2 disposed in the exhaust passage 1 to an engine controller 16, and the controller 16 supplies fuel according to the air-fuel ratio information. The amount of fuel is calculated, the injection amount of fuel is supplied to the intake passage 4 by the injection nozzle 3 in a timely manner, and the ignition plug 22 performs ignition processing in a timely manner.

The intake passage 4 of the engine 10 includes an air cleaner 5 and an intake pipe 6, and a throttle valve 7 is provided in the middle thereof. A throttle sensor 8 serving as load information is attached to the throttle valve 7. An exhaust passage 1 is provided with an air-fuel ratio sensor 2 and a muffler (not shown) downstream thereof.

The vehicle has left and right front wheels WFL, WFR as drive wheels, and left and right rear wheels W
RL and WRR are provided as driven wheels. These left and right front wheels
WFL and WFR are respectively provided with wheel speed sensors 11 and 12 for outputting wheel speeds VFL and VFR of the front left and right wheels, and wheel speeds for outputting the wheel speeds VRL and VRR of the rear left and right wheels for the left and right rear wheels WRL and WRR. Sensor 1
3, 14 are provided opposite each other.

These wheel speed information are stored in the traction controller 15
Is input to

In addition, the traction controller 15 is connected with 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 speed Ne information based on the signal. Have been. Furthermore, the traction controller 15 data can also output a from each sensor to output the target engine torque T ₀ below the engine controller 16.

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 / A /
F) Information is entered. Further, a water temperature sensor 19 for emitting temperature information of engine cooling water, an intake air temperature sensor 17 for emitting intake air temperature information, an atmospheric pressure sensor 18 for emitting air pressure information, and a knock sensor 21 for emitting knock information of the engine 10 are connected.

The traction controller 15 and the engine controller 16 are each a main part of a microcomputer, and in particular, the traction controller 15 calculates a target engine torque T ₀ according to a target engine torque calculation program shown in FIG. Engine controller
Output to 16. The engine controller is shown in Figs.
The control value is calculated according to the control program shown in the figure, and the injection nozzles 15 of the cylinders other than the cut cylinder are driven to perform the injection control at appropriate times.

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

Here, the traction controller 15 has functions as slip detection means and target engine torque calculation means,
The slip detecting means captures the wheel speed of the driving wheel of the vehicle by the driving wheel speed detecting means, and the wheel speed of the non-driving wheel of the vehicle by the non-driving wheel speed detecting means, detects slip according to these outputs, and detects the target engine torque. The calculating means calculates a target engine torque based on the slip detected by the slip detecting means. The engine controller 16 has a function as an engine output regulation amount calculation unit and an engine output control unit. A plurality of engine output restricting means are set for each target engine torque, and a map in which the ignition timing, the air-fuel ratio, and the number of cylinders are stored in advance as one output control group using the engine speed and the intake air amount as parameters. Using this map, a predetermined output control group is selected in accordance with the latest target engine torque, engine speed, and intake air amount. The engine output control means controls the output of the engine based on the selected output control group.

Among them, the control processing by the traction controller 15 and the engine controller 12 will be described with reference to each control program of FIGS. 9 to 12.

The traction controller 15 is a main routine (not shown) which determines the failure of each sensor and circuit, sets an initial value in each area and performs initial setting, receives the output of each sensor, sets each sensor in each area, and performs other processing. ing. Predetermined interrupt timing during that time (time interrupt)
The routine enters a target engine torque calculation routine every time.

Here, in step a1, each data is received from each wheel speed sensor and stored in a predetermined address _VFR , _VFL , _VRR .

In step a2, the vehicle body speed Vc is obtained from the left and right average wheel speeds of the non-driven wheels and stored. Further, in step a3, the wheel speed Vc
Is differentiated to calculate the longitudinal acceleration ac. Then, at the peak value ac _MAX of the longitudinal acceleration ac, the theoretical value (μ
-S properties) so represents the maximum coefficient of friction of the road surface as can be seen from, in step a4 sets the peak value ac _MAX of the longitudinal acceleration and the estimated value of the friction coefficient of the road surface. Then, the slip ratio S at that time is obtained. Then, in step a5, the target wheel speed _{VW is} calculated by adding the wheel speed equivalent to the slip ratio S. Upon reaching the step a6 differentiates the target wheel speed V _W to calculate a target wheel acceleration V _W / dt.

In step a7, the drive wheel torque for realizing the target wheel speed V _W is calculated based on the target wheel acceleration V _W / dt, the drive wheel torque T _W according to the vehicle weight W, the tire radius R, and the running resistance. taking into account the transmission gear ratio to the drive wheel torque T _W with a8, calculates the target engine torque T _0, and outputs to the engine controller 16.

The engine controller 16 starts the ECI main routine by key-on.

Here, first, the initial settings (not shown)
At ab1, the detection data of each sensor is read and taken into a predetermined area.

In step b2, it is determined whether the engine is in the fuel cut zone or not by the engine speed Ne and engine load information (here, the intake air amount A / N)
In the fuel cut zone, 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 returns to step b1.

When it is determined that the current time is not the fuel cut zone and the process reaches step b5, the fuel cut flag FCF is cleared, and it is determined in step b6 whether the well-known air-fuel ratio feedback condition is satisfied. At a time point when the condition is not satisfied, for example, in a transient operation range such as a power operation range, the process directly proceeds to step b9.

When step b7 is reached assuming that the air-fuel ratio feedback condition is satisfied, a correction value KF based on the output of the air-fuel ratio sensor 2 according to the normal feedback control constant
Calculate B.

Then, in step b8, this value is fetched into the address KAF and the process proceeds to step b9.

In step b9, the other fuel injection pulse width correction coefficient KD
T and the correction value TD of the dead time of the fuel injection valve is set according to the operating condition, further, the process proceeds to step b11 to calculate the correction value for the ignition angle phi _M calculation described later.

The correction value for the ignition angle [psi _M calculated here, the water temperature correction value Wpusai _M to advance in accordance with the coolant temperature decreases, the atmospheric pressure correction value Pψ to advance with a decrease atmospheric pressure, depending on the knock information Correction value N for adding a predetermined retard amount
And a battery voltage correction value B # for adding a predetermined retard amount according to the battery voltage drop is calculated based on each sensor output, and stored in a predetermined area.

In step b10, the dwell angle is set based on a predetermined map (an example of which is shown in FIG. 8 so that the dwell angle increases in accordance with the engine speed Ne).

Thereafter, the process proceeds to an engine output regulation routine of step b11, and thereafter returns to step b1.

In this engine output regulation routine, first, an engine output regulation start condition (a traction control request signal, a range other than the N and R ranges, and the like), not shown, is determined.
When the start condition is satisfied, the process proceeds to step c1 and the subsequent steps. When the engine output regulation end condition (sensor failure, etc.) is determined and the end condition is satisfied, the process returns to the main routine.

In step c1 the current target engine torque T ₀ is taken out an intake air quantity A / N and the engine speed Ne, selects a map corresponding to these parameters. Here, a map as shown in FIG. 2 or FIG. 4 is previously stored in the ROM of the controller.

This map of the requirements that can regulate the engine output, the cylinder deactivation The number of fuel cut, is set for each target engine torque T ₀ the air-fuel ratio and the ignition angle [psi _M as one of the output control group. That is, when the target engine torque T ₀ shown in FIG. 4 is [Kgfm], each engine speed Ne and the intake air amount
A number of cuts corresponding to the A / N, it is possible to air-fuel ratio and the ignition angle [psi _M is read from the predetermined area.

Here, the target engine torque T ₀ in is provided in accordance with the integer for each predetermined interval, if there is a value between the adjacent torque value, and the number of cuts by interpolation, the air-fuel ratio complement referred ignition angle [psi _M is calculated. By this interpolation processing, a sense of discomfort due to a sudden change in the control value can be reduced, and the number of maps can be reduced.

When step c2 is reached, it is determined whether or not the current engine speed Ne is lower than a specified speed N1 (set based on the engine stall limit value). If the current engine speed Ne is lower, the cut number is corrected to zero. And proceeds to step c4. Here, the reduction rate ΔNe of the engine speed Ne is calculated based on the previous engine speed, etc., and if this exceeds a set value ΔN1 (set based on an engine stall limit value), it is determined that there is a possibility of engine stall and the number of cuts is set to zero. And if it does not exceed it, the process directly proceeds to step c6. This step c2
Stall can be prevented by the processing of c5.

In step c6 for calculating a target ignition angle [psi _0. Here, a water temperature correction value W # that is advanced according to a decrease in water temperature, an atmospheric pressure correction value P # that is advanced according to a decrease in atmospheric pressure, and a knock correction value N # that adds a predetermined retard amount according to knock information. If, and ignition angle [psi _M corrected by these correction values takes in the battery voltage correction value Bψ for adding a predetermined retard amount according to the battery voltage drop to calculate the target ignition angle [psi _0.

Thereafter, it is determined whether the delayed side or not from the step c7 in top dead center (TDC), the delay-side setting the target ignition angle [psi ₀ to TDC. This prevents early ignition on the intake side in two-cylinder simultaneous ignition. This processing can be eliminated in the case of individual ignition. When the target ignition angle [psi ₀ is at the advance side in step c7, the process proceeds to a step c9. When step c9 is reached, the cut cylinder number is determined based on a map as shown in FIG. 6 according to the number of cylinder cuts.

The map in FIG. 6 shows the structure of the engine 10 (here, V-type six cylinders as shown in FIG. 5), the cylinder number corresponding to each number of cuts, taking into account the rotational balance, cooling efficiency, etc. based on the characteristics. Is set.

When the cylinder number corresponding to the number of cuts is set in this way, the process proceeds to step c10. Here, the air-fuel ratio correction coefficient KAMP corresponding to the current operation information (A / N, Ne) is calculated from a map as shown in FIG. 4, this value is input to the address KAF, and the process returns to the main routine.

During such an ECI main routine, the injector driving routine of FIG. 12 and the ignition driving routine of FIG. 13 are performed.

The injector drive routine reaches steps d1 and 2 with a predetermined crank pulse interruption, takes in the intake air amount A / N and the engine speed Ne, and in step d3, sets the fuel cut flag FC.
It is determined whether or not F is 1; if it is 1, it returns; if it is 0, it proceeds to step d4. Here, setting the basic fuel pulse width T _B,
In step d5, the main pulse width data Tinj = T _B × KAF × KDT
+ TD is calculated, and the process proceeds to step d6.

Here, Tinj is the driver for driving the injector,
The driver is set to the uncut cylinder driver, the driver is triggered in step d7, the injection nozzle 3 performs fuel injection, and the routine returns. This processing reduces the output for the cut cylinder.

On the other hand, when the step e1 is reached by the interruption of the crank pulse, the dwell angle is set in the dwell angle counter through which the primary current flows by the dwell angle which is the primary current supply crank angle width. Target ignition angle [psi ₀ to ignition timing counters that can be output in step e2 target point corner angle [psi ₀ the ignition signal in is set.

Thus, each counter drives the ignition circuit when the predetermined crank pulse is counted, and causes the ignition plug 22 to perform the ignition operation. In the ignition process, an output reduction of only retard amount containing target ignition angle [psi ₀ good responsiveness can be realized.

(Effect of the Invention) As described above, in the present invention, the ignition timing, the air-fuel ratio, and the number of cylinders are previously mapped as one output control group, so that the calculation for obtaining these control values is simplified. Thus, an optimum engine output according to the driving state of the vehicle can be obtained. In addition, the responsiveness of the output control by controlling the output control group obtained from the map is improved, and there is an advantage that the output control is continuous and a sense of incongruity does not occur. In particular, when the target engine torque is between the maps, the interpolation processing is performed, so that a sense of discomfort due to a sudden change in the control value can be further reduced. In particular, engine stall can be prevented by correcting the number of cylinders to be stopped based on the current engine speed or the rate of change in engine speed.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an engine output control device as one embodiment of the present invention, FIG. 2 is a block diagram of control means of the above device, and FIG. 3 is a slip ratio of a vehicle equipped with the above device. FIG. 4 is a characteristic diagram of a friction coefficient, FIG. 4 is an explanatory view of a map for calculating the number of cuts, an air-fuel ratio, and an ignition angle used in the above-mentioned device; FIG. Is an explanatory diagram of a cylinder-stop cylinder number setting map used in the above-mentioned device; FIG. 7 is an explanatory diagram of an operating range calculation map used in the above-mentioned device; FIG. 8 is an explanatory diagram of each dwell calculation map used in the above-mentioned device; 10 is a flowchart of a target engine torque calculation program executed by the traction controller used in the above-mentioned device, and FIGS. 10 to 13 are flowcharts of control programs executed by the engine controller used in the above-mentioned device. 2 ... air-fuel ratio sensor, 3 ... injection nozzle, 7 ... throttle valve, 8 ... throttle position sensor, 9 ... airflow sensor, 10 ... engine, 11, 12, 13, 14 ... wheel speed sensor, 15 ... Traction controller, 16 ...
The engine controller, 22 ...... spark plug, T ₀ ...... target engine torque, [psi _{0 ......} target ignition angle, A / F ...... air,

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location F02P 5/15 F02P 5/15 B (72) Inventor Makoto Shimada 5-33 Shiba, Minato-ku, Tokyo No. 8 Inside Mitsubishi Motors Corporation (72) Inventor Katsunori Ueda 5-33-8 Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Corporation (56) References JP-A-2-201058 (JP, A) JP-A-2-181042 (JP, A) JP-A-61-46725 (JP, A)

Claims (3)

(57) [Claims] An engine speed detecting means for detecting an engine speed; an intake air amount detecting means for detecting an intake air amount of the engine; an ignition timing setting means for setting an ignition timing of the engine; An engine output control apparatus comprising: an air-fuel ratio control unit that sets an air-fuel ratio of an engine; and a cylinder number setting unit that sets the number of cylinders to be cylinders of the engine. A target engine torque calculating means for calculating an engine torque, a plurality of target engine torques are set for each of the target engine torques, and the engine speed and the intake air amount are used as parameters,
A map in which the ignition timing, the air-fuel ratio, and the number of cylinders are stored in advance as one output control group; and a predetermined output control group according to the target engine torque, the engine speed, and the intake air amount. , And controlling the output of the engine based on the selected output control group. 2. The engine output control device according to claim 1, wherein when the target engine torque is between the plurality of maps, a predetermined output control group is selected by interpolation processing. Output control device. 3. The engine output control device according to claim 1, wherein: based on a current engine speed or an engine speed change rate.
An output control device for an engine, which corrects the number of cylinders in a selected output control group.