JPH1150870A - Output control device of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a constant vehicle speed and accelerating performance by a fixed amount of accelerator operation without being affected by a variation in vehicle weight and road surface gradient. SOLUTION: Based on an actual intake air amount QAR detected by an intake air amount sensor and an engine speed NE during a constant speed traveling, an actual engine output PS0 is set referring to a map MAPPS0 (S34), and a theoretical engine output PSinit is calculated based on a theoretical formula lead from a traveling resistance during the constant speed traveling (S35). Also both engine outputs PS0 and PSinit are compared with each other, and an apparent vehicle weight A is set so that the theoretical engine output PSinit is roughly equal to the actual engine output PS0 (S35 to S38). Based on the apparent vehicle weight A, a required acceleration (a), and a vehicle speed V, a required power PS is set using a theoretical formula led from the traveling resistance (S39) and, based on the required power PS, a throttle opening is set.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine output control device which controls a throttle opening in accordance with a change in vehicle weight due to the number of passengers, the weight of luggage, and the like to obtain a constant running state.

[0002]

2. Description of the Related Art Conventionally, in the case where an accelerator pedal and a throttle valve are mechanically connected, the throttle valve rotates in proportion to the amount of depression of the accelerator pedal. In the case of shifting to, when trying to obtain a running state equivalent to flat road running in this uphill running, it is necessary to depress the accelerator pedal a lot because the running load increases, and therefore the road surface gradient is continuously In order to always maintain a constant traveling state on a traveling road changing to a low speed, a driver is required to have fine accelerator work corresponding to a change in traveling load.

[0003] This is the same also in acceleration running.
In order to obtain a certain level of acceleration performance, accelerator work according to the road gradient is required.

In this respect, in an engine having an electronically controlled throttle valve as disclosed in Japanese Patent Application Laid-Open No. Hei 2-40039, for example, the accelerator pedal and the throttle valve are electrically connected to each other, and the relationship between the accelerator pedal depression amount and the accelerator pedal depression amount. Therefore, the vehicle speed and the acceleration performance according to the accelerator pedal operation amount can be obtained irrespective of the road surface gradient.

[0005]

By the way, the running load applied to the engine is changed not only by the change in the road surface gradient but also by the increase and decrease of the vehicle weight due to the occupants and the load capacity of the load.

However, the above prior art does not take into account changes in the vehicle weight itself, and therefore follows the change in running load caused by a large increase or decrease in the number of occupants or load. When trying to obtain a certain level of running performance on a road where the road gradient changes, a different accelerator pedal operation amount is required for each change in vehicle weight, which may give the driver a sense of discomfort. Become.

In view of the above circumstances, the present invention can obtain a constant vehicle speed and acceleration performance with a constant accelerator pedal operation amount without being affected by changes in vehicle weight or road surface gradient.
It is an object of the present invention to provide an engine output control device that reduces the burden on a driver for accelerator work.

[0008]

According to a first aspect of the present invention, there is provided a first engine output control apparatus for electronically controlling a throttle opening, wherein a control means for setting the throttle opening is provided. Means for setting the required acceleration from the accelerator pedal operation amount; means for setting the apparent vehicle weight based on the actual engine output and the theoretical engine output; and the required horsepower based on at least the required acceleration and the apparent vehicle weight. Means for setting the throttle opening, and means for setting the throttle opening based on at least the required horsepower.

The output control device of the second engine is the output control device of the first engine, wherein the means for setting the apparent vehicle weight sets an actual engine output based on the engine load during constant speed running. Means for setting the apparent vehicle weight to a value such that the theoretical engine output calculated using the apparent vehicle weight as a parameter is substantially the same as the actual engine output.

A third engine output control device comprises:
Alternatively, in the output control device for the second engine, the apparent vehicle weight is represented by mass.

That is, the first engine output control device sets the required acceleration from the accelerator pedal operation amount,
Also, the apparent vehicle weight is set based on the actual engine output and the theoretical engine output, the required horsepower is set based on at least the required acceleration and the apparent vehicle weight, and the throttle opening is set based on at least the required horsepower. I do.

In the second engine output control device, the first engine
In the engine output control device, the actual engine output is set based on the engine load at the time of constant speed driving, and the theoretical engine output calculated using the apparent vehicle weight as a parameter is apparently a value close to the actual engine output. Set the vehicle weight.

In the third engine output control device, the first engine
Alternatively, in the output control device of the second engine, the apparent vehicle weight is represented by the mass to be a value in consideration of a road surface gradient such as a flat road or an uphill road.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an overall schematic diagram of the engine control system. Reference numeral 1 in the drawing denotes an engine main body. An intake pipe 4 is communicated via an air chamber 3 to a collection portion of an intake manifold 2 which communicates with an intake port (not shown) of the engine main body 1. An air cleaner 5 is provided at the air intake. On the other hand, a catalyst 8 is interposed in an exhaust pipe 7 communicating with a collection portion of an exhaust manifold 6 communicating with an exhaust port (not shown).

A crank angle mark formed by a projection or a slit formed at every predetermined crank angle on the outer periphery of the signal disk plate 9 on the signal disk plate 9 axially attached to the crankshaft of the engine body 1. Is detected.

Further, an intake air amount sensor 11 is disposed immediately downstream of the air cleaner 5 in the intake pipe 4, and a throttle valve 12 is provided upstream of the air chamber 3;
This throttle valve 12 has a throttle actuator 13
Are connected. The throttle valve 12 is not mechanically connected to the accelerator pedal 14, and its opening is controlled by the throttle actuator 13.

An injector 15 faces the intake manifold 2 immediately upstream of the intake port, and an oxygen sensor 16 faces the exhaust manifold 6.

The operation amount of the throttle actuator 13 is set by a control unit (ECU) 21. An input port of the control device 21 includes the crank angle sensor 10, the intake air amount sensor 11, the oxygen sensor 16, an accelerator opening sensor 17 which is connected to the accelerator pedal 14 and detects the opening of the accelerator pedal 14, a clutch pedal. An engine such as a clutch switch 19, a vehicle speed sensor 20 and the like, and various sensors and switches for detecting the running state of the vehicle are connected to the engine. Further, various actuators necessary for engine drive control such as the throttle actuator 13 and the injector 15 are connected to an output port of the control device 21.

The control device 21 calculates the opening amount (throttle opening) of the throttle valve 12, the fuel injection pulse width for the injector 15 and the like based on output signals from various sensors and switches for detecting the engine and the vehicle running state. The drive signal is transmitted to the throttle actuator 1
3. Output to the injector 15.

The throttle opening control in the control device 21 is executed according to the flowcharts shown in FIGS. Turn on the ignition switch (not shown)
When the control device 21 is turned on, the initialization routine shown in FIG. 2 is executed only once for the first time. In this routine, parameters read in each routine described later are set to initial values. First, in step S1, an apparent vehicle weight A expressed by mass is set to an initial value A0 (for example, 1000/1000).
9.8 [Kgf · S ² / m]), and in step S2, the rolling resistance coefficient u is set to an initial value u0 (for example, 0.02);
In step S3, the air resistance coefficient B is set to an initial value B0 (for example,
0.002), the drive system transmission efficiency coefficient E is set to an initial value E0 (for example, 0.9) in step S4, and the decrease value dα is set to an initial value dα0 (for example, 10 [d] in step S5).
eg]) and terminate the routine.

The initial value A0 is the gross vehicle weight when no vehicle is loaded, and the initial values u0, B0, E are unique values determined for each vehicle.

Next, the throttle opening setting routine shown in FIG. 3 will be described. This routine is executed every predetermined time (for example, 10 msec).
Then, the current accelerator pedal operation amount (absolute amount) β is calculated based on the output signal from the accelerator opening sensor 17, and in step S12, the table TBβ is referred to with interpolation calculation based on the accelerator pedal operation amount β. To set the required acceleration a.

As shown in FIG. 5, in the table TBβ, according to the accelerator pedal operation amount β, the position of the general accelerator pedal operation amount used during constant speed running is set to 0, and the accelerator operation amount The required acceleration a of a negative value is stored in an area where the acceleration decreases, and the required acceleration a of a positive value a is obtained in advance from an experiment or the like and stored in an area where the accelerator operation amount increases.

For example, when shifting from acceleration running to constant speed running, the driver depresses the accelerator pedal 14 first,
When the predetermined speed is reached, the accelerator pedal 14 is returned. At this time, the required acceleration a set based on the accelerator pedal operation amount β is initially set to the large required + a, and gradually approaches the zero value.

Next, at step S13, the vehicle speed sensor 20
The vehicle speed V calculated based on the output signal is read, and in step S14, it is determined whether V = 0 (stopped) and a ≦ 0 (accelerator pedal released), and if V = 0 and a ≦ 0 Jumps to step S23, and sets the throttle opening α
To zero and exit the routine.

On the other hand, if V ≠ 0 or a> 0, the routine proceeds to step S15, where the engine speed NE calculated based on the output signal of the crank angle sensor 10 is read. The actual intake air amount QAR calculated based on the output signal is read.

Then, in step S17, the required horsepower PS
Read. The required horsepower PS is set in a necessary horsepower setting routine shown in FIG. 4 (details will be described later).
Next, in step S18, based on the required horsepower PS and the engine speed NE, the map MA shown in FIG.
The required intake air amount QA is set by referring to the PQA with interpolation calculation. The map MAPQA stores an optimum required intake air amount QA obtained in advance by an experiment or the like for each operation region, using the required horsepower PS and the engine speed NE as parameters.

Then, when the routine proceeds to step S19, the map MAPα shown in FIG. 8 is obtained based on the required intake air amount QA and the engine speed NE, which are representatives of the required engine load.
Is set with the interpolation calculation to set the throttle opening α.
This map MAPα stores an optimum throttle opening α obtained in advance by experiment or the like for each operating region, using the required intake air amount QA and the engine speed NE as parameters.

At step S20, it is determined based on the output signal of the clutch switch 19 whether or not the gear is being shifted.
Is in the released state, the gear shift operation has not been performed, and the process jumps to step S22.

When the clutch switch 19 is depressed and the clutch pedal 18 is depressed, the process proceeds to step S21 because the shift operation is being performed, and the throttle opening α is subtracted by a decrease value dα (for example, 10 [deg]). Is updated (α ← α−dα), and it is determined in step S22 whether or not the accelerator opening α is equal to or greater than 0. If α ≧ 0, the routine exits from the routine. If α <0, the process proceeds to step S23, the throttle opening α is set to zero (α ← 0), and the routine exits.

The required horsepower PS read in step S17 is set by a necessary horsepower setting routine shown in FIG. This routine is executed at predetermined time intervals. First, in step S31, it is determined whether or not the vehicle speed V is 0 (stopped state). If V ≠ 0, the process proceeds to step S32, where V =
If it is 0, the process branches to step S33, sets the vehicle speed V to 1, and jumps to step S39.

When the process proceeds from step S31 to step S32, it is determined whether or not the current running state is a constant vehicle speed. The determination as to whether the vehicle speed is constant or not is made, for example, by comparing the vehicle speed V at the time of execution of the previous routine with the current vehicle speed V, and determining whether or not the difference falls within a constant dead band (for example, ± 2 km / h).

If the vehicle speed V is constant, step S
Proceeding to 34, if the vehicle speed V is changing, such as during transient operation, jump to step S39.

When proceeding to step S34, step S34
In step S38, the current apparent vehicle weight A is calculated. First, in step S34, the actual intake air amount QAR, which is representative of the engine load, and the engine speed N
Based on E, the current actual engine output PS0 is set by referring to the map MAPPS0 shown in FIG. 6 with interpolation calculation. The map MAPPS0 includes the actual intake air amount Q
AR and the engine speed NE as parameters,
The actual engine output PS0 is obtained in advance from an experiment or the like and stored for each operating region.

Next, at step S35, the theoretical engine output PSinit during the constant speed running on a flat road is calculated based on the theoretical formula derived from the running resistance expressed by the following formula. PSinit ← (u · A + B · V ² ) · V / E where u · A · V / E is the rolling resistance and B · V ² · V /
E is the air resistance.

After turning on the ignition switch, the apparent vehicle weight A at the time of the first execution of the routine is an initial value A0 (for example, 1000 / 9.8 [Kgf
・ S ² / m]).

Then, at step S36, the theoretical engine output PSinit at the time of constant speed running obtained at step S35.
And the actual engine output PS0 set with reference to the map MAPPS0 with interpolation calculation, and the theoretical engine output PSinit is set to a dead band ± C (for example, 5 [PS]) based on the actual engine output PS0. It is determined whether or not it is stored. If PSinit <PS0-c, step S3
7, the apparent vehicle weight A is set to a set value d (for example, 100 /
9.8 [Kgf · S ² / m]) Update with the value increased by step S
Returning to 35, the theoretical engine output PSinit during constant speed running is calculated again.

On the other hand, in step S36, PSinit> P
If S0 + c, the process proceeds to step S38, where the apparent vehicle weight A is updated with a value reduced by the set value d (for example, 100 / 9.8 [Kgf · S ² / m]), and the process returns to step S35, where the constant speed is set. The theoretical engine output PSinit during running is calculated again.

In step S36, when the theoretical engine output PSinit falls within the dead band ± C based on the actual engine output PS0 (PS0−c ≦ PSin
it ≦ PS0 + c), that is, when the current apparent vehicle weight A is determined, the process proceeds to step S39. This apparent vehicle weight A is
Since the running conditions are calculated based on the engine load and the running resistance at the time of constant speed running, factors related to the road surface gradient are included as well as the load / carrying weight of passengers and the number of occupants.

When the process proceeds from step S32, S33, or S36 to step S39, the required horsepower PS for achieving the required acceleration a is calculated from the theoretical formula including the acceleration state shown in the following formula, and the routine exits. PS ← (a · A + u · A + B · V ² ) · V / E Here, a · A · V / E is an acceleration resistance.

As described above, in the present embodiment, the apparent vehicle weight A, which is a factor for determining the required horsepower PS, is variably set in accordance with the load weight, the number of passengers, and the road surface gradient. Since it is calculated as a value including the apparent vehicle weight A, for example, even when the traveling load increases due to an increase in the luggage loading weight or the number of passengers, or traveling on an uphill road, the above apparent vehicle weight A increases. Since the required horsepower PS increases, the driver can run with a constant accelerator work regardless of a change in the running load. In particular, when traveling on an uphill road, the amount of accelerator pedal depression equivalent to a flat road,
It is possible to travel at the same speed or acceleration as on a flat road, and accelerator work is reduced.

Note that, as shown in FIG.
If it is determined that the gearshift operation is being performed at 0, the throttle opening α is decreased by the decrease value dα at every set calculation cycle (for example, 10 msec) at step S21 until the clutch switch 19 is turned on again. Even if the driver continues to depress the accelerator pedal 14 during the shifting operation, the engine speed does not increase, and the burden on the accelerator work is further reduced.

Then, a drive signal corresponding to the throttle opening α is output to the throttle actuator 13,
The opening degree of the throttle valve 12 is controlled such that the intake air amount corresponding to the required intake air amount QA supplied to the cylinder flows.

Note that the fuel injection pulse width for the injector 15 is obtained by correcting the basic injection amount set based on the required intake air amount QA or the actual intake air amount QAR and the engine speed NE by feedforward correction and feedback using various correction coefficients. Corrected and set.

In this embodiment, the manual transmission is shown as the power transmission means. However, it goes without saying that the present invention can be applied to a vehicle equipped with an automatic transmission. in this case,
The determination as to whether or not the shift operation is being performed in step S20 is performed with reference to a shift instruction signal output according to a shift shift program set by the control device 21.

[0046]

According to the first aspect of the present invention, the required horsepower is based on at least the required acceleration set based on the accelerator pedal operation amount and the apparent vehicle weight set based on the actual engine output and the theoretical engine output. Is set at least based on the required horsepower, and the throttle opening is set based on the required intake air amount and the engine speed, so that the required horsepower is a function of the apparent vehicle weight. And change. Therefore, if the apparent vehicle weight is set variably with respect to changes in vehicle weight or road surface gradient, the required horsepower increases or decreases accordingly,
It is possible to obtain a constant vehicle speed and a constant acceleration performance with a constant accelerator pedal operation amount without being affected by changes in vehicle weight or road surface gradient, and to reduce the burden on the driver for accelerator work.

According to a second aspect of the present invention, in the first aspect, the apparent vehicle weight is set to a value such that the theoretical engine output calculated using the apparent vehicle weight as a parameter approximates the actual engine output. As a result, it is possible to calculate the required horsepower according to the increase or decrease in the number of crew members and the change in the road surface gradient without providing a vehicle weight sensor or inclination sensor, etc., so that it can be used at low cost and in existing vehicles. Easy and versatile.

[Brief description of the drawings]

FIG. 1 is an overall schematic diagram of an engine control system.

FIG. 2 is a flowchart showing an initialization routine.

FIG. 3 is a flowchart showing a throttle opening setting routine;

FIG. 4 is a flowchart showing a required horsepower setting routine.

FIG. 5 is a conceptual diagram of a table for setting a required acceleration.

FIG. 6 is a conceptual diagram of a map for setting a current engine output.

FIG. 7 is a conceptual diagram of a map for setting a required intake air amount.

FIG. 8 is a conceptual diagram of a map for setting a throttle opening.

FIG. 9 is a characteristic diagram showing a change in a throttle opening during a shift operation.

[Explanation of symbols]

 1: Engine main body A: Apparent vehicle weight a: Required acceleration NE: Engine speed PS: Required horsepower PSinit: Theoretical engine output PS0: Actual engine output QA: Required intake air amount QAR: Actual intake air amount V: Vehicle speed α: Throttle Opening β: accelerator pedal operation amount

Claims (3)

[Claims] 1. An engine output control device for electronically controlling a throttle opening, wherein said control means for setting said throttle opening comprises: means for setting a required acceleration from an accelerator pedal operation amount; Means for setting the apparent vehicle weight based on the theoretical engine output; means for setting the required horsepower based on at least the required acceleration and the apparent vehicle weight; and means for setting the throttle opening based on at least the required horsepower. An output control device for an engine, comprising: 2. The means for setting the apparent vehicle weight includes: means for setting an actual engine output based on the engine load during constant-speed running; and a theoretical engine output calculated using the apparent vehicle weight as a parameter. 2. An engine output control device according to claim 1, further comprising means for setting an apparent vehicle weight to a value substantially equal to an actual engine output. 3. The engine output control device according to claim 1, wherein the apparent vehicle weight is represented by mass.