JP2003328811A - Fuel injection system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such a problem that a delay in torque variation from an accelerator operation causes some occupants to depress the accelerator excessively at start or the like, and can cause overshoot of vehicle speed, in a vehicle in which the rate of change in accelerator travel read by an accelerator sensor is moderated to prevent sudden torque variation in an engine. <P>SOLUTION: Although the rate of change in accelerator travel read by an accelerator sensor 1 is moderated by accelerator travel correcting means 2, and a fuel injection quantity is computed from the moderated accelerator travel, a habit in accelerator operations read by the accelerator sensor 1 is learned and stored by a learning function 6, and the moderation factor is changed to a new moderation factor is dependence on the habit. In a vehicle driven by an occupant whose accelerator operation is fast, the moderation factor can be low to produce torque variation in quick response to the occupant's accelerator operation. Overshoot can be thus suppressed for improved drivability and fuel economy. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection device for calculating a fuel injection amount on the basis of a value (a value obtained by smoothing) the rate of change of an accelerator opening read by an accelerator sensor. Is. In the present specification, "blunting" the rate of change is expressed as "Namasu".

[0002]

2. Description of the Related Art There are cases where the accelerator is quickly operated due to immaturity in driving technology or a slight erroneous operation. If such an operation is performed, the vehicle may be jerky or a shock or abnormal noise may be generated due to the backlash of the transmission, especially when the vehicle starts or runs at a low speed. On slippery roads such as icy roads and bad roads, if the accelerator is operated quickly, the engine may suddenly change the torque and slip may be induced. For the purpose of avoiding such a problem, there is known a vehicle in which the changing speed of the accelerator opening read by the accelerator sensor is smoothed at a constant smoothing rate so that the engine does not suddenly change in torque.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention As shown above,
On the other hand, if the accelerator opening speed is changed, the torque change of the engine can be suppressed even if the accelerator is intentionally swiftly depressed. Therefore, depending on the occupant, the accelerator may be excessively depressed when starting. Then,
Even if the accelerator is released when the target vehicle speed is reached, the vehicle speed will eventually become faster than the target speed. In addition, since the vehicle speed becomes too fast and the accelerator opening that is returned is dampened, overshoot may occur repeatedly. In this way, the change in the accelerator opening change speed read by the accelerator sensor is a factor that causes overshoot with respect to the target vehicle speed of the occupant, which deteriorates drivability and fuel efficiency. There is a problem that invites.

[0004]

An object of the present invention is to control the rate of change of the accelerator opening read by the accelerator sensor with an appropriate smoothing rate according to the accelerator operation speed of the vehicle occupant or the slipperiness of the road surface. This is to improve drivability and fuel efficiency by eliminating the occurrence of overshoot that has been induced by conventional technology (technology that changes the accelerator opening change rate at a constant smoothing rate).

[0005]

[Means for Solving the Problems] [Means for Claim 1] In a fuel injection device adopting the means for claim 1, the accelerator opening correction means of the control unit controls the accelerator opening read by an accelerator sensor. The fuel injection amount is calculated based on the accelerator opening calculated by the accelerator opening correction means. Then, the moderation rate of the accelerator opening correction means is provided to be changed by the moderation rate changing means on the basis of the speed of change of the read accelerator opening. By providing in this way, when the accelerator operation speed of the occupant is high, the moderation rate can be lowered to suppress the occurrence of overshoot, and drivability and fuel consumption can be improved. On the contrary, when the accelerator operation speed of the occupant is slow, the smoothing rate can be increased to suppress abrupt torque fluctuation on a slippery road surface, and to suppress the induction of slip due to torque fluctuation.

[Means of Claim 2] In the fuel injection device adopting the means of Claim 2, the accelerator opening correction means of the control device learns and stores the rate of change of the accelerator opening read from the accelerator sensor. It has a learning function to change the smoothing rate based on the speed of change. By providing in this way, it becomes possible to set the moderation rate according to the habit of the accelerator operation of the occupant. In other words, in a vehicle in which an occupant with a fast accelerator operation gets in, the rapid acceleration operation is repeated, so that the moderating rate becomes low. Therefore,
Since the torque fluctuation according to the accelerator operation of the occupant can be obtained, the occurrence of overshoot can be suppressed, and the drivability and the fuel consumption can be improved.

[Means for Claim 3] In the fuel injection system adopting the means for claim 3, the accelerator opening correction means of the control device smoothes the road surface detected by the road surface state detection means. The accelerator opening correction means for determining the rate and changing the accelerator opening read by the accelerator sensor based on the smoothing rate is provided, and the fuel injection is performed based on the accelerator opening determined by the accelerator opening correction means. Calculate the amount. By providing in this way, it is possible to increase the smoothing rate on slippery road surfaces so that the engine does not suddenly change the torque even if the accelerator is operated quickly, improving the startability on slippery road surfaces. Or, the occurrence of slip can be suppressed.

[Means of Claim 4] A fuel injection system adopting the means of Claim 4 is a dual system accelerator sensor according to the slipperiness of the road surface detected by the road surface state detection means in the switching means of the control device. Switch the output value generation pattern of.
Then, the control device calculates the fuel injection amount based on one of the output values of the switched dual system accelerator sensor. By providing in this way, on a slippery road surface, an output value generation pattern that generates a small output value with respect to the accelerator opening can be selected from the output value generation patterns of the dual system accelerator sensor. That is, even if the accelerator is operated quickly, the engine will not suddenly change in torque, so that it is possible to improve the startability on a slippery road surface and suppress the occurrence of slip.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to three examples and modifications. [First Embodiment] FIGS. 1 to 6 are drawings for explaining the first embodiment. First, the basic structure of a fuel injection device will be described with reference to FIG.

In the fuel injection device having the basic structure shown in FIG. 1 (a), a change in the accelerator opening read from the accelerator sensor 1 is smoothed by the accelerator opening correction means 2 at a predetermined smoothing rate. The fuel injection amount is calculated based on the accelerator opening, and includes an accelerator sensor 1, an accelerator opening correction unit 2, an injection amount calculation unit 3, a fuel injection valve 4, and the like.

The accelerator sensor 1 is a depression amount / voltage converter for detecting the depression amount of the accelerator pedal operated by the occupant's foot. As shown in FIG. 2, the accelerator sensor 1 outputs it as the accelerator opening increases. The voltage is increased, and it is used within the range of 0% to 100% of the accelerator opening, and outputs a voltage according to the accelerator opening.

The accelerator opening correction means 2 and the injection amount calculation means 3 correspond to an ECU 5 (corresponding to a control device,
It is a program written in the ROM of the engine control unit. The injection amount calculation means 3 is stored in the ROM, in addition to the accelerator opening, data such as the engine speed, the gear stage of the transmission, the water temperature, and the atmospheric pressure (data detected by the operating state detection means). The fuel injection amount and the injection timing are calculated based on an arithmetic expression, a map, etc., and the fuel injection valve 4 is controlled to be opened and closed at the calculated timing, so that the calculated fuel injection amount is transferred from the fuel injection valve 4 into the engine cylinder. It is what is injected.

As described above, the accelerator opening correction means 2 is a means for averaging the rate of change of the accelerator opening read from the accelerator sensor 1 with a smoothing rate (speed variable rate), for example, the solid line A in FIG. When the accelerator is depressed at the speed shown in, when the smoothing rate α is the standard smoothing rate β (α =
In β), the accelerator opening is smoothed and output as shown by the solid line B in the figure. In this way, by accelerating the accelerator opening at the reference smoothing rate β, when the actual accelerator opening is A% of the target, the smoothed accelerator opening becomes B% and the opening difference Δθ occurs. To do. That is, there is a time difference ΔT from the actual accelerator opening reaching the target accelerator opening to the accelerating accelerator opening reaching the target accelerator opening.

Thus, the opening difference Δθ and the time difference ΔT between the actual accelerator opening and the acclimated accelerator opening.
As described in the section of the prior art, depending on the occupant's sensation of the accelerator change and the vehicle speed change, the accelerator may be excessively pressed. Then, even if the accelerator is returned when the target vehicle speed is reached, the returned accelerator opening is also blunted, and as a result, the vehicle speed becomes faster than the target speed and an overshoot occurs. In some cases, on the contrary, the overshoot may be repeated by inducing the operation of returning the accelerator too much. Such overshoot leads to deterioration of drivability and also leads to deterioration of fuel efficiency.

Therefore, in this embodiment, the habit of the changing speed of the accelerator opening which is different for each occupant is learned, and when the occupant has a high accelerator operating speed, the smoothing rate α in the accelerator opening correcting means 2 is reduced. Then, it is provided so as to avoid the above problems. Specifically, the ECU 5 of this embodiment
As shown in FIG. 1 (b), a learning function 6 is programmed to learn different accelerator operation habits for each occupant and calculate a correction value γ for lowering the standard smoothing rate β from the learned habit. Therefore, at a predetermined timing (timing at which no trouble occurs even if the smoothing rate α is updated), the smoothing rate α is replaced with a new smoothing rate α (α = β-γ).

With this arrangement, when the tendency of the accelerator operating speed to be learned is learned, as shown by the broken line C in FIG. 3, the accelerator opening (solid line B (See), the accelerator opening changes faster. The broken line C that changes due to the learning of the accelerator operation speed changes within the relation of A ≧ C ≧ B.

In this embodiment, the correction value γ is obtained from the habit of the accelerator operation, and the correction value γ is subtracted from the reference smoothing rate β to obtain a new smoothing rate α (α = β-γ). However, a new smoothing rate α'according to the habit of accelerator operation is directly obtained, and at a predetermined timing, the smoothing rate α is replaced with the new smoothing rate α '(α ← α') May be. In this case, the new smoothing rate α ′ calculated by learning changes within the range of 0 ≦ α ′ ≦ β.

Next, the learning function 6 described above will be described. The learning function 6 is, as shown in FIG. 1B, a learning determination / measurement function 7, an accelerator operation speed statistical function 8, and a correction value for calculating a correction value γ from each data statistically obtained by the statistical function 8. A calculation function 9 is provided. In this example,
It is provided to calculate the correction value γ for each region so that an appropriate smoothing rate α can be obtained in each of the low and high accelerator opening regions and the multiple engine speed regions. ing.

The learning determining / measuring function 7 has a low opening degree determining unit for determining whether or not a fast accelerator operation is performed when the accelerator opening degree is in a low opening degree area, and an accelerator opening degree in a high opening degree area. At times, a high opening degree determination unit that determines whether or not a quick accelerator operation is performed is provided.

As shown in FIG. 4, a specific example of the low opening determination unit is that the accelerator operation amount for one time is equal to or greater than a predetermined operation amount Δθ and the accelerator opening calculated based on the change time ΔT1. When the rate of change (Δθ / ΔT1) of the degree is equal to or higher than the predetermined rate of change (the accelerator opening is 5% or more), it is determined that the accelerator operation is fast. When a fast accelerator operation is recognized, the rate of change of the accelerator opening at that time (Δ
θ / ΔT1) is stored as data.

A specific example of the high opening determination unit is, as in the above case, that the accelerator operation amount of one time is a predetermined operation amount Δθ or more and the accelerator opening amount calculated based on the change time ΔT2. When the change speed (Δθ / ΔT2) is equal to or more than the predetermined change speed (the accelerator opening is 20% or more), it is determined that the accelerator operation is fast. When a fast accelerator operation is recognized, the rate of change of the accelerator opening at that time (Δ
.theta ./. DELTA.T2) is stored as data.

As shown in FIG. 5, the statistical function 8 includes statistics of the changing speed of the accelerator opening in the low opening area and the changing speed of the accelerator opening in the high opening area for each rotation area. It is a statistic. In each region, so-called moving average is used to determine the average value x of the accelerator opening in each region. The moving average is, for example, an average value x based on n data.
Every time y pieces of data are accumulated in the judging section, the old data y pieces are deleted, and the average value x is obtained from the n pieces of data in which new y pieces of data are added instead. It is a thing.

Specifically, taking the lower left region (low speed region and low opening amount region) of FIG. 5 as an example, when a quick accelerator operation is repeatedly performed in that region, the distribution of the operating speed of the accelerator operation is The accelerator operation shifts to the earlier side, and the result average value x shifts to the earlier side. In the graph in each area in FIG. 5, the vertical axis represents the number of occurrences, and the horizontal axis represents the operation speed of the accelerator (fast in the left direction and slow in the right direction).

When the average value x is obtained from n pieces of data to which new y pieces of data have been added, the correction value calculation function 9 determines that the deviation Δx (see FIG. 5) from the previous average value x is equal to or larger than a predetermined deviation. At this time, a new correction value γ is calculated from the newly obtained average value x. Then, the new correction value γ obtained by the correction value calculation function 9 is set at a predetermined timing (timing at which no trouble occurs even if the smoothing rate is updated).
The smoothing rate α is replaced with a new smoothing rate α (α = β−γ).

Next, an example of calculating the accelerator opening output to the injection amount calculating means 3 will be described with reference to the flowchart of FIG. When the accelerator opening calculation routine is entered (start), the operation mode is first determined from the shift position of the transmission (step S1). When the determination result is neutral or parking, the voltage value output from the accelerator sensor 1 is A / D converted and the injection amount calculation means 3 is used as it is without changing the speed of the accelerator opening.
(Step S2), and this routine ends.

If the result of the determination in step S1 is the traveling mode, first the voltage value output from the accelerator sensor 1 is set to A
/ D conversion (step S3). It is determined whether or not the accelerator operation speed is in a learning region (step S4).
). When it is determined from the determination result that the accelerator operation speed is not learned, the speed of change of the accelerator opening is smoothed using the previous smoothing rate α and output to the injection amount calculation means 3 (step S5). Exit the routine.

When it is determined from the determination result of step S4 that the accelerator operation speed is to be learned, the correction value γ is calculated by statistically processing the accelerator operation speed (step S6). Then, from the standard smoothing rate β, step S
The new smoothing rate α obtained by subtracting the correction value γ calculated in 6 is updated (step S7). Subsequently, it is determined whether or not it is the update timing of the new smoothing rate α (step S8), and when it is determined that the determination result is inappropriate as the update timing, the process proceeds to step S5. When it is determined that the determination result of step S8 is the update timing, the rate of change of the accelerator opening is smoothed using the new smoothing rate α and output to the injection amount calculation means 3 (step S9). To finish.

[Effects of the First Embodiment] In the fuel injection device of the first embodiment, the accelerator opening correction means 2 smoothes the rate of change of the accelerator opening read from the accelerator sensor 1, and the accelerator thus smoothed. Although the fuel injection amount is calculated based on the opening, the change rate of the accelerator opening read from the accelerator sensor 1 is learned and stored by using the learning function 6, and the accelerator opening is performed based on the learned change rate. The smoothing rate α in the degree correcting means 2 is automatically changed to the new smoothing rate α. As a result, the moderation rate α according to the habit of the accelerator operation of the occupant is automatically set. In other words, in a vehicle on which an occupant with a fast accelerator operation rides, the quick acceleration operation is repeated, so that the moderation rate α becomes low, and the torque fluctuation of the engine quickly responds to the accelerator operation by the occupant. Therefore, the occurrence of overshoot caused by accelerating the rate of change of the accelerator opening can be suppressed, and drivability and fuel efficiency can be improved.

A specific example will be described with reference to FIG.
When the moderation rate α becomes a value smaller than the standard moderation rate β by learning the habit of the speed change of the occupant's accelerator operation (α = β−γ), for example, at the speed shown by the solid line A in FIG. When the accelerator is depressed, the accelerator opening is smoothed and output to the injection amount calculation means 3 as indicated by a broken line C in the figure. As a result, when the actual accelerator opening is A% of the depression target, the smoothed accelerator opening is C% and the opening difference is Δθ ′. In addition, compared with the change in the accelerator opening that is made at the standard smoothing rate β (solid line B), the actual accelerator opening reaches the target accelerator opening, and then the opened opening is the target accelerator opening. It is possible to reduce the time difference until reaching the opening degree from ΔT by ΔT ′. As a result, the sensation difference between the accelerator change and the vehicle speed change made by some occupants is reduced, the problem that the occupant does not step on the accelerator too much is avoided, and the occurrence of overshoot is prevented.

Second Embodiment FIGS. 7 and 8 are drawings for explaining the second embodiment. First, the fuel injection device will be described with reference to FIG. In the following embodiments, the same functions as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. The fuel injection system according to the second embodiment employs a well-known double system accelerator sensor 11 that generates different pattern output values depending on the accelerator operation amount. The dual accelerator sensor 11 is a depression amount / voltage that generates two patterns of output voltage as shown by solid lines A and B in FIG. 8 in accordance with the depression amount of an accelerator pedal operated by a passenger. The output value generation pattern shown by the solid line B, for example, generates half the output value of the output value generation pattern of the solid line A (that is,
B = A / 2).

On the other hand, the fuel injection system of this embodiment is equipped with a road surface condition detecting means 12 for detecting the slipperiness of the road surface on which the vehicle is traveling. As an example of the road surface state detecting means 12, in the case of a vehicle equipped with an ABS (abbreviation of anti-lock brake system), the deviation amount of the rotation speed of the rotation sensor of each wheel provided on each wheel is smaller than the predetermined deviation amount. It is to detect that the road surface is slippery when it is large.
Other means such as determining that the road surface is slippery when the wiper is turned on may be adopted.

On the other hand, the ECU 5 has a road surface condition detecting means 1
Switching means 13 for switching and reading the output value of the dual system accelerator sensor 11 according to the slipperiness of the road surface detected by 2.
Is programmed. When the road surface state detecting means 12 detects that the road surface is not slippery, the switching means 13 selects the output value generation pattern of the solid line A in the dual system accelerator sensor 11 and A / D converts the output value. Then, the accelerator opening is obtained, and the accelerator opening obtained from the solid line A is output to the injection amount calculation means 3. Further, when it is detected that the road surface is slippery, the output value generation pattern of the solid line B in the dual system accelerator sensor 11 is selected, and the output value is A / D converted to obtain the accelerator opening degree. The calculated accelerator opening is output to the injection amount calculation means 3.

Further, the switching means 13 is programmed with a function of returning from a state where the accelerator opening is obtained from the output value generation pattern of the solid line B to a state where the accelerator opening is obtained from the output value generation pattern of the solid line A. It should be noted that a driver's switch operation may be used together for this function.
This return function is a state where the vehicle speed reaches a predetermined speed (for example, 10 km / h) or more after starting the vehicle, and after detecting that the road surface is not slippery, the accelerator is temporarily set to a predetermined value or more for a predetermined time or less. When it is returned, it is switched so as to obtain the accelerator opening degree from the output value generation pattern of the solid line A.

[Effects of the Second Embodiment] The fuel injection system according to the second embodiment has a dual accelerator sensor 1 on a slippery road surface.
Of the output value generation patterns of 1, an output value generation pattern that generates a small output value with respect to the accelerator operation amount is selected. As a result, even if the accelerator is operated quickly, the engine will not suddenly change the torque, so that it is possible to improve the startability on slippery road surfaces and suppress the occurrence of slip.

[Third Embodiment] In the second embodiment, when it is detected that the road surface is slippery, the output value generation pattern of the dual system accelerator sensor 11 is switched to suppress the changing speed of the accelerator opening. An example was given. On the other hand, in the third embodiment, the accelerator sensor 1 shown in the first embodiment is used.
In addition to using (one output pattern), the smoothing rate is calculated according to the slipperiness of the road surface, and the accelerator opening read by the accelerator sensor 1 is changed based on the smoothing rate.

As a concrete example, as shown in FIG. 9, the accelerator opening correction means 2 of the present embodiment, when detecting that the road surface is not slippery, has a smoothing rate of 0% (or a small amount). The accelerator opening is obtained as the smoothing rate), and when it is detected that the road surface is slippery, the accelerator opening is obtained with the smoothing rate being a predetermined percentage. The moderation rate when detecting that the road surface is slippery may be set by learning the habit of the operating speed of the accelerator of the vehicle occupant. Even if it is provided in this way, the same effect as that of the second embodiment can be obtained.

[Modification] The first and second embodiments described above
The embodiments may be used in combination, or the first embodiment and the third embodiment may be used in combination. When the first embodiment and the second embodiment are combined, during the mode in which the road surface is slippery and the speed change of the accelerator opening is suppressed, the speed change of the accelerator opening is not further smoothed. The smoothing operation is provided so as to stop.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of a fuel injection device (first embodiment).

FIG. 2 is a characteristic diagram of an accelerator sensor (first embodiment).

FIG. 3 is a graph for explaining a change in the accelerator opening degree due to the smoothing (first embodiment).

FIG. 4 is a graph showing a change in accelerator opening for explaining a learning determination / measurement function (first embodiment).

FIG. 5 is a graph for explaining that statistics of change rate of accelerator opening is taken for each region (first example).

FIG. 6 is a flowchart for explaining an example of calculating an accelerator opening (first embodiment).

FIG. 7 is a schematic block diagram of a fuel injection device (second embodiment).

FIG. 8 is a characteristic diagram of a dual accelerator sensor (second embodiment).

FIG. 9 is a schematic block diagram of a fuel injection device (third embodiment).

[Explanation of symbols]

1 Accelerator sensor 2 Accelerator opening correction means 5 ECU (control unit) 6 learning functions 11 Double system accelerator sensor 12 Road surface condition detection means 13 Switching means

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3G065 AA04 CA31 DA05 DA06 DA15                       EA13 FA06 FA07 GA10 GA11                       GA31 GA41 GA46 HA06 HA21                       HA22 JA04 JA09 JA11 KA02                       KA15 KA16                 3G084 BA05 BA13 CA03 CA04 DA08                       DA11 DA17 EB06 EB17 EC04                       FA01 FA06 FA10 FA20 FA34                 3G301 HA06 JB01 JB08 KB10 LA03                       LB01 LC03 NA08 NB03 NB13                       NE17 NE19 PA11Z PE01Z                       PE03Z PF01Z PF03Z PF08Z

Claims (4)

[Claims] 1. A fuel injection device comprising: a driving state detecting means for detecting a driving state of a vehicle; and a control device for calculating a fuel injection amount based on the driving state of the vehicle detected by the driving state detecting means. There, the driving state detection means includes an accelerator sensor that reads an accelerator opening operated by a vehicle occupant, the control device is an accelerator that changes the accelerator opening read by the accelerator sensor based on a moderation rate. The accelerator opening correction means and the smoothing rate changing means for changing the smoothing rate based on the changing speed of the accelerator opening read by the accelerator sensor are provided, and the accelerator opening determined by the accelerator opening correcting means is provided. A fuel injection device, characterized in that the fuel injection amount is calculated based on the degree. 2. The fuel injection device according to claim 1, wherein the accelerator opening correction means learns and stores a change speed of the accelerator opening read from the accelerator sensor, and the moderation rate is based on the learned change speed. A fuel injection device having a learning function for changing the fuel injection rate. 3. A fuel injection device comprising: a driving state detecting means for detecting a driving state of a vehicle; and a control device for calculating a fuel injection amount based on the driving state of the vehicle detected by the driving state detecting means. There, the driving state detecting means comprises an accelerator sensor for reading an accelerator opening operated by a vehicle occupant, and a road surface state detecting means for detecting slipperiness of a road surface on which the vehicle travels, and the control device includes the road surface. The accelerator opening correction means is provided for obtaining the smoothing rate according to the slipperiness of the road surface detected by the state detecting means, and changing the accelerator opening degree read by the accelerator sensor based on the smoothing rate. A fuel injection device, characterized in that an injection amount of fuel is calculated based on the accelerator opening obtained by the opening correction means. 4. A fuel injection device comprising: a driving state detecting means for detecting a driving state of a vehicle; and a control device for calculating a fuel injection amount based on the driving state of the vehicle detected by the driving state detecting means. The driving state detecting means includes an accelerator sensor that reads an accelerator opening degree operated by a vehicle occupant, and a road surface state detecting means that detects slipperiness of a road surface on which the vehicle is traveling, and the accelerator sensor is the accelerator. It is a dual system accelerator sensor that generates different patterns of output values depending on the opening degree, and the control device is the dual system accelerator sensor according to the slipperiness of the road surface detected by the road surface state detecting means. Of the fuel injection amount is calculated based on the output value of the dual system accelerator sensor switched by the switching means. A fuel injection device characterized by the above.