JPH0242148A - Output control device for engine - Google Patents

Abstract

PURPOSE:To satisfactorily and compatibly obtain the car speed maintaining property and accelerating property by correcting the output of an engine in response to the relationship between the detection value and the reference value of the accelerator opening and changing the driving speed of a means adjusting the output of the engine in response to the magnitude of the running load. CONSTITUTION:The accelerator opening of an engine is detected by a means (b), the target output of the engine is determined by a means (c) in response to the detection result, the drive of a means (a) adjusting the output of the engine is controlled by a means (d) in response to the determination result. The car speed is detected by a means (e), the reference accelerator opening is set by a means (f) in response to the detection result. When the detected accelerator opening is larger than the reference accelerator opening, the target output is corrected to be increased by a means (g). The running load of a vehicle is detected by a means (n). When the running load is large, the driving speed of the means (a) is changed to be decreased by a means (i).

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an engine output control device.

(Prior Art) Recently, many engines, particularly automobile engines, are designed to electrically control the magnitude of engine output, for example, the opening of a throttle valve, depending on the opening of the accelerator. In this case, since the magnitude of the engine output can be arbitrarily changed according to the accelerator opening degree, the engine output can be optimized according to the driving condition and the like.

From this point of view, in the device described in JP-A No. 61-126346, when cornering, that is, when turning the steering wheel, the opening of the throttle valve is smaller than when driving straight for the same accelerator opening. In other words, a system has been proposed in which the engine output is reduced to further improve cornering safety.

(Problems to be Solved by the Invention) By the way, when controlling engine output, it is desirable to satisfy both vehicle speed maintenance performance and acceleration performance during constant speed driving. Therefore, while the target engine output is determined according to the accelerator opening, if the accelerator opening is larger than the standard accelerator opening determined according to the vehicle speed, the engine output will be larger for the same accelerator opening. It has been considered to correct the above-mentioned target engine output so that it becomes. To explain this point in detail, in order to maintain vehicle speed, it is desirable that the difference between the amount of change in engine output and the amount of change in accelerator opening is small, so the above target engine output should be relatively small. It is hoped that On the other hand, in order to obtain sufficient acceleration, it is desirable that the target engine output be increased. For this reason, the standard accelerator opening is set as large enough to maintain the vehicle speed, that is, commensurate with the driving load according to the current vehicle speed. When the opening degree becomes larger than the opening degree, it is assumed that an acceleration request has been made and the target engine output can be corrected to become larger. As a result, both vehicle speed maintenance and acceleration are satisfied.

However, the running load varies greatly depending on the running conditions, especially the road surface slope. Therefore, if the standard accelerator opening degree is set on the assumption that the running load is small, such as on a flat road.

When a large engine output is required, for example when driving on a hill, a situation may occur where the accelerator opening becomes larger than the reference accelerator opening even though acceleration is not requested. This means that the amount of change in engine output with respect to the amount of change in accelerator opening becomes large, and the ability to maintain vehicle speed when the running load is large is impaired.

On the other hand, if the standard accelerator opening is set based on the assumption that the driving load is high, such as on a hill, even though acceleration is requested when the driving load is small, such as on a flat road. Since the accelerator opening degree is smaller than the standard accelerator opening degree, sufficient engine output cannot be obtained and the acceleration path is impaired.

Therefore, an object of the present invention is to change the amount of change in engine output with respect to the amount of change in accelerator opening with reference to the standard accelerator opening set according to vehicle speed as a boundary, and to change the amount of change in engine output with respect to the amount of change in accelerator opening. An object of the present invention is to provide an engine output control device that can satisfy both vehicle speed maintenance performance and acceleration performance at a high level.

(Means and operations for solving the problems) In order to achieve the above-mentioned object, the present invention has the following configuration. That is, as shown in the block diagram in FIG. 12, an output adjusting means for adjusting the output of the engine, an accelerator opening detecting means for detecting the accelerator opening, and an accelerator that receives the output of the accelerator opening detecting means. a target output determining means that determines a target engine output according to the opening degree; a drive control means that receives an output from the target output determining means and controls driving of the output adjusting means so that the target engine output is achieved; and vehicle speed. A reference accelerator opening setting means receives an output from the vehicle speed determining means and sets a reference accelerator opening according to the vehicle speed; The accelerator opening detecting means and the reference accelerator opening setting means Output correction that corrects the target engine output so that when the accelerator opening is larger than the reference accelerator opening, the engine output is larger for the same accelerator opening than when it is smaller. means, a running load detecting means for detecting a running load of a heavy vehicle; and receiving an output from the running load detecting means, the driving speed of the output adjusting means is lower when the running load is large than when it is small. and drive speed changing means for changing the driving speed so that the driving speed changes.

With this configuration, engine output changes more slowly in response to changes in accelerator opening when the running load is high, for example on a hill, compared to when the running load is small, for example on a flat road. It will change.

This means that if the standard accelerator opening is set based on the assumption that the running load is low, such as on a flat road, the engine output will change slowly when the running load is large, such as on an uphill road. Become. Therefore, even if the target engine output is corrected to be large relative to the accelerator opening, the vehicle speed characteristic when the running load is large is satisfied.

Conversely, if the standard accelerator opening degree is set on the assumption that the driving load is high, the engine will change quickly when the driving load is small, so the target engine output for the accelerator opening degree will not be corrected and will be small. Even if it is left as is, the acceleration performance will be satisfied.

(Example) Examples of the present invention will be described below based on the attached drawings.

In the overall configuration shown in FIG. 1, the output of an engine 1 is transmitted via a transmission 2 to drive wheels (not shown). This gear shift a2 is
In the embodiment, it is comprised of a torque converter 3 with a low 2-up clutch and a multi-speed gear mechanism 4 for four forward speeds. Further, the engine 1 is of an automatic type, and the amount of intake air, that is, the engine output, is adjusted by adjusting the opening degree of a throttle valve 12 provided in an intake passage 11 of the engine 1. And the throttle valve 12 is
It is driven by an actuator 13 such as a DC servo motor or a step motor.

The details of the part that drives the throttle valve 12 are as shown in FIG. First, 31 to 33 are three sliders, first to third, arranged in parallel, and the first slider 31 in the middle is connected to the throttle valve 12 via a wire 34. A second slider 32 on one side of the slider 31 is connected to a pulley 38 via a wire 37, and this pulley 38 is connected to a rotary actuator 13 such as a motor via an electromagnetic clutch 39. ing. When both sliders 31 and 32 are at the right stroke end in FIG. 2, when the second slider 32 is displaced to the left, the first slider 31 pressed by it is immediately displaced to the left. It's like getting.

On the other hand, the third slider 33 is connected to the accelerator 38 via a wire 35. When both the first and third sliders 31 and 33 are at the right stroke end,
When the third slider 33 is displaced to the left in the figure, after the third slider 33 is displaced by the amount corresponding to the invalid stroke,
The first slider 31 is pressed and displaced to the left. As shown in FIG. 3, this invalid stroke intersection is set so that the throttle valve 12 begins to open when the accelerator opening reaches 50% or more.

Each of the sliders 31 to 33 is biased to the right stroke end unless the accelerator 36 is operated (the first slider 31 is
2). Further, when an abnormality occurs in the control system of the actuator 13, the coil 39a of the clutch 39 is energized and the clutch 39 is disconnected.

Reference numeral 21 in FIGS. 1 and 2 is a control unit, which is constructed using a digital or analog computer, and more specifically, a microcomputer in the embodiment. Signals from the respective sensors (switches) 22 to 24 are input to this control unit 21, while signals from the control unit 21 are input to the actuator 13.
Output for. The sensor 22 detects the accelerator opening. The sensor 23 detects vehicle speed. The sensor 24 detects the gear position (gear position) such as 1st speed and 2nd speed.

Note that the control unit 21 basically includes a CPU, a ROM
, RAM, CLOCK, input/output interface, A/D converter, etc. as necessary, but since these are known configurations when using a microcomputer, detailed explanation thereof will be omitted. . Of course, the throttle characteristics and the like described later are stored in the ROM.

Outline of Control The control unit 21 controls the actuator 13 so that the target throttle opening corresponds to the accelerator opening. An overview of this control will be described below.

First, the basic throttle characteristics are mapped and set as shown in FIG. In this embodiment, three types of basic throttle characteristics are set: 1 speed, 2nd speed, 3rd speed, and 4th speed. , a basic throttle opening TB is determined according to the accelerator opening α.

The final target throttle opening Tn is determined by multiplying the basic throttle opening TB by a gain Gl, which will be described later. Then, the actuator 13 is driven at a predetermined speed, which will be described later, so that the target throttle opening degree Tn is achieved.

The gain Gl is mapped in advance for each gear position (gear position) such as 1st speed, 2nd speed, etc., using vehicle speed V and deviation ΔA as parameters, as shown in FIG. This deviation ΔA
is, as shown in Fig. 5, from the current accelerator opening α to R
The value obtained by subtracting the reference accelerator opening degree αRL on the /L line, that is, the value indicating the margin driving force. Note that the R/L line in FIG. 5 follows the basic throttle characteristics shown in FIG. 4. In this figure, two R/L lines are shown: the symbol X indicates a flat road for setting a reference value, and the symbol Y indicates a sloped road with a certain road surface slope for comparison. It is. Therefore, the deviation ΔA
differs depending on whether the R/L is for flat roads (X-rays) or for uphill roads (Y-lines), and this difference is expressed as G in Figure 5.
It is shown as 1.

As is clear from FIG. 7, the gain G1, which is made up of the above-determined ΔA and the vehicle speed, is set larger as ΔA becomes larger, indicating that the acceleration request is stronger.
Also, the larger the vehicle speed is, the smaller it becomes. This allows R/
Steady running performance near L (ability to maintain a constant vehicle speed) and sufficient acceleration performance when acceleration is requested are both satisfied. In addition, the above G
As described later, ΔA used for the 1 determination is as follows.
The definite integral value may be used.

The driving speed of the actuator 13, that is, the rate of change in engine output is increased (faster) when the running load is small, and is decreased (slowed) when the running load is large. To explain this point in detail, first, the target throttle opening Tn
However, the actuator 13 is driven by the following equation (1).

TVOn =K(Tn-TVOn-t)+TVO
n-1 @ # * (1) K: Filter constant TVOn: Current throttle opening TVOn~1: Previous throttle opening In the above equation (1), when the running load is large, the filter constant K becomes 2. At other times, that is, when the running load is small, Kl is set so that K1>K2. As a result, when the running load is large, the engine output is changed slowly, and when the running load is small, the engine output is changed quickly. In addition, at the time of sudden acceleration, the engine output is quickly changed by setting =1 until the predetermined time To has elapsed from detection of the sudden acceleration, so that the acceleration performance is more fully satisfied.

FIG. 8 diagrammatically shows the above-mentioned control contents. In FIG. 8, at time t1, the flat road becomes a boarding road, and due to a delay in detection time, a flag indicating that the road is a boarding road is set to 1 at time t2.

By setting the flag to 1, the filter constant K
is changed from Kl to 2, and the engine output is changed slowly. For this reason, the throttle opening, that is, the change in engine output, becomes smooth.
Vehicle speed characteristics are fully satisfied. Furthermore, at time t1,
The driver unconsciously presses the accelerator greatly after confirming the road to be climbed, and this causes a large change in the throttle opening, but by pressing the accelerator, the engine output increases to match the increase in driving load. It is also done by the person himself/herself.

When rapid acceleration is requested at time t3 while traveling uphill, the filter constant K is changed to 1, the engine output is changed quickly, and an increase in engine output is quickly ensured. Then, when the predetermined time To has elapsed, the filter constant K is changed to 2 again. Then, at time ts, the flat road detection flag is reset to O, thereby resetting the filter constant K by one helimeter.

The determination of the historical running load, that is, whether the road is a flat road or an uphill road, is determined based on the deviation ΔA and the vehicle speed g, with reference to the map shown in FIG. In FIG. 11, hysteresis is provided to prevent hunting in determining whether the road is flat or uphill. In other words, the α line in Figure 11 is used to determine that the vehicle is on a flat road when the vehicle is running on an uphill road, and the β line is used to determine that the vehicle is on an uphill road when the vehicle is traveling on a flat road. The region between the α-ray and the β-ray is considered to be for hysteresis. Of course, both the alpha ray and the beta ray are prepared depending on the gear position.

Here, when determining the vehicle body acceleration, in principle, it is obtained by differentiating the vehicle speed. however,
Since a general vehicle speed sensor mounted on a vehicle contains considerable noise, in this embodiment, the speed sensor is set to 0.
The vehicle speed is sampled every 5 seconds, and the vehicle body acceleration is determined by subtracting the older sampled value (3 seconds ago in this embodiment) from the most recent sampled value.

Further, when determining the running load, the constant integral value thereof is used together with the deviation ΔA and the vehicle body acceleration, and a phase difference is provided between the two. To explain this point in detail, the driver often performs operations that slightly change the accelerator opening even when driving at a constant speed, and due to the inertia of the vehicle, body acceleration refers to changes in the accelerator opening. This will occur with some delay. Therefore, in order to compensate for subtle fluctuations in the accelerator opening, the driving load is determined using the constant integral value of both the deviation ΔA and the vehicle body acceleration at a certain moment, rather than using the deviation ΔA and the vehicle body acceleration. In addition, in order to compensate for the delay in the change in vehicle body acceleration with respect to the change in accelerator opening, a definite integral value fgdt of the vehicle body acceleration is set for a definite integral value fΔAdt of the deviation ΔA.
The details of the running load detection will be explained with reference to the flowchart shown in Fig. io. In the following explanation, S indicates a step. In the embodiment, the running load is roughly divided into two types: one is equivalent to a flat road, and the other is equivalent to an uphill road having a slope higher than the road surface slope.

Next, details of running load detection will be explained with reference to the flowchart shown in FIG.
indicates a step. In the embodiment, the running load is roughly divided into two types: a flat road, and a road equivalent to an uphill road having a slope greater than the road surface slope.

First, in S2, it is determined whether the count value of the timer has become smaller than the example. The determination in S2 is
This corresponds to determining whether 500 m5 ec has passed since data input at P2 in FIG. 9, which will be described later, when the initial value set for the timer is 500 m5 ec. If the determination in S2 is NO, the process returns as is, and the determination in S2 is YES.
At the time of ES, processing from S3 onwards is performed.

In S3, the register of the measured vehicle speed V is replaced. Further, in S4, register replacement of vehicle body acceleration is performed. After this, in S5, the oldest vehicle speed v6 is subtracted from the latest vehicle speed to obtain the vehicle body acceleration d v
/ d t is calculated, and in P6 this d v /
dt is set as the latest vehicle acceleration GO. Then, in S7, the G exchanged with the above GO in S4
1-G5, the integral product fgdt of the vehicle body acceleration is calculated. Furthermore, in S8, register replacement for the deviation ΔA is performed.

After S8, in S9, an R/L map corresponding to the gear position is selected, and in SIO, the accelerator opening degree αRL on the selected R/L map is read out in accordance with the current vehicle speed. After that, in Sll, by subtracting αRL read out in S10 from the actual accelerator opening α,
The current deviation ΔA is calculated. Then, in S12, it is determined whether ΔA in S11 is smaller than zero. If the determination in S12 is NO, ΔA of Sll
is directly set as ΔAO used for later integration, and if YES is determined in S12, ΔAO is set as 0 through the process of S13. After this, in S15, the integral value fΔAdt of the deviation ΔA
is from ΔA3 to ΔA8 stored in the register of S8.
Calculated by adding up to. As is clear from the process in S15, the calculation of fΔAdt is older than the calculation of the vehicle body acceleration fgdt, and thus a phase difference is given to the values at both ends.

After S15, in 316, it is determined whether or not the current flag is 1, that is, whether or not the vehicle is currently in a state where the running load is large, which corresponds to running uphill. This S16
If the determination is No, it means that the running load is currently low, which corresponds to running on a flat road. At this time, in S17, a map (line β in FIG. 11) for determining the transition from the flat road to the uphill road is selected according to the gear position. After this, S17
By comparing fΔadt calculated in step 315 with the map selected in step 315, the expected acceleration g1 on the map is read out. Then, in S19, it is determined whether the vehicle body acceleration fgdL calculated in S7 is larger than the expected acceleration gl. If this judgment is YES,
Since the vehicle is currently traveling on a flat road, the timer is set to an initial value of 500 m5ec at 320, and then the process returns. Also, if the determination in S19 is NO, S2
1, the determination in S19 is N twice in a row.

It is determined whether or not. If the determination in S21 is NO, the process directly proceeds to S20, and if the determination in S21 is YES, it is assumed that the transition has occurred from the flat road to the uphill road, and the flag is set to 1 in S22. , the process moves to S20. Note that the determination in step 521 is disabled in order to more reliably prevent hunting from occurring in the determination of a flat course and a boarded course.

If the determination in S16 is YES, the vehicle is currently traveling on an uphill road, and in this case, processing is performed in S23 to S27 to determine whether the vehicle has moved to a flat road or not. That is, in S23, a map (line α in FIG. 11) for determining the transition from the uphill road to the flat road is selected according to the gear position, and in S24, the expected acceleration g2 on the selected map is read out.

Then, in S25, on the condition that fgdt is smaller than S2 and this determination has been made twice in a row, the flag is reset to O indicating flat road running in S27, and then the process moves to S20. In this case, the above S27
The process proceeds to S20 without passing through.

Throttle ControlFor details on throttle control that also takes into account driving load,
This will be explained with reference to the flowchart in FIG. In addition,
In the following explanation, P indicates a step.

First, at Pl, the entire system is initialized, and then at P2, signals from each of the sensors 22 to 24 are read.

At P3, the basic throttle opening TB corresponding to the accelerator opening α is read in reference to the basic throttle control shown in FIG. Next, at P4, R/ is adjusted according to the gear position.
The L map (FIG. 5) is selected. Then, in P5, the reference accelerator opening degree αRL corresponding to the current vehicle speed V is read with reference to the map selected in P4.

At P6, the deviation ΔA is calculated by subtracting the reference accelerator opening αRL from the current accelerator opening αRL.

After this, in P7, it is determined whether ΔA is smaller than zero. If the determination at P7 is YES (when the board is on the way down), the process moves to P9 after setting ΔA to zero at P8, and if the determination at P7 is No, the process goes to P9 without going through P8.
Move to.

At P9, a map (FIG. 7) in which the gain Gl is set is selected according to the gear position. Continue with PI3, PI3
The gain Gl is determined by referring to the map selected in . Then, in PIO, the final target throttle/nottle opening Tn is calculated by multiplying the basic target throttle opening TB determined in P3 by the gain G1.

After FilO, the above-mentioned climbing path is detected in PI3 (Fig. 10), and the flag continues to be set to 1 in PI3.
It is determined whether or not. This flag is set at 522 or S27 in FIG.
If the answer in step 7 is NO, it is a flat road. At this time, the filter constant K is set to 1 in PI3, and then the target throttle opening degree T V On to be output this time is calculated in PI3 based on the equation (1). After this, this TVOn is output at PI3 (realization of TVOn).

If the determination in step 13 is YES, it means that the vehicle is on the uphill road. At this time, the rate of change dα/dt of the accelerator opening degree α is calculated in PI3. After this, in P18,
It is determined whether dα/dt is larger than a set value.

When the determination of PI3 is YES, this means that sudden acceleration is required even on a climbing road, so it is time to increase the rate of change of the engine output by the predetermined time To. For this reason,
In PI9, set the timer to a predetermined time To (initial value) °
After setting the filter constant K to K at P2O,
1, and then proceed to P15.

If the determination in P18 is NO, the timer counts down in P21, and continues! At tP22, it is determined whether the timer count value To has become smaller than zero. If the determination in P22 is No, it means that the predetermined time To has not elapsed since the sudden acceleration request was made. At this time, after setting the filter constant K to Kl in P23, the process moves to PI3.

If the determination in P22 is No, it means that the predetermined time To has elapsed since sudden acceleration was detected, or that sudden acceleration has not been detected. At this time, after the filter constant K is set to 2 in P24, the process moves to PI3.

In the above embodiments, the running load is detected in two stages, one corresponding to running on a flat road and one corresponding to running on an uphill road, but it can also be detected in three or more stages or continuously O (metamorphosis (stepless)).

Of course, the running load may be detected using a slope sensor.

(Effect of the invention) As is clear from the above description, the present invention has been made.

The requirements for both heavy speed maintenance and acceleration were 1. Satisfaction can be achieved regardless of the magnitude of the running load.

[Brief explanation of the drawing]

FIG. 1 is an overall system diagram showing one embodiment of the present invention. FIG. 2 is a diagram showing a detailed example of a part that drives a throttle valve. FIG. 3 is a throttle characteristic diagram obtained when the actuator for driving the throttle valve fails in the throttle valve shown in FIG. No. 41 is a diagram showing basic throttle characteristics. FIG. 5 is a diagram showing the relationship between the road meeting load line and the deviation ΔA. gSB diagram is a diagram schematically showing the control content of the present invention. FIG. 7 is a diagram showing a map for determining gain 1. FIG. 8 is a time chart showing the control details of the present invention. 9 and 10 are time charts showing control examples of the present invention. FIG. 11 is a diagram showing a map used to determine whether it is a flat course or an uphill course based on the deviation ΔA and acceleration. FIG. 12 is a block diagram showing the overall configuration of the present invention. l: Engine 12: Throttle valve 13: Actuator 21: Control units 22 to 24: Sensors Fig. 4 Fig. 6 Fig. 7

Claims (1)

[Claims] (1) Output adjusting means for adjusting the output of the engine; Accelerator opening detection means for detecting the accelerator opening; receiving the output of the accelerator opening detecting means and determining a target engine output according to the accelerator opening. target output determining means; drive control means for receiving the output from the target output determining means and controlling the drive of the output adjusting means so as to achieve the target engine output; vehicle speed detecting means for detecting vehicle speed; and the vehicle speed determining means. a reference accelerator opening setting means for receiving an output from the means and setting a reference accelerator opening according to the vehicle speed; Output correction means for correcting the target engine output so that the engine output is larger when the accelerator opening is larger than a reference accelerator opening than when it is smaller than when the accelerator opening is smaller; load detection means; and drive speed changing means that receives an output from the running load detection means and changes the drive speed of the output adjustment means so that when the running load is large, the driving speed of the output adjustment means is smaller than when the running load is small. An engine output control device comprising: