JP6828779B2 - Vehicle control device - Google Patents

Description

The present invention relates to a vehicle control device using an engine as a drive source.

Conventionally, coasting has been performed to improve fuel efficiency by stopping the supply of driving force from the internal combustion engine to the drive wheels during deceleration and coasting.

As related to coasting, there is a vehicle control device described in Patent Document 1. The vehicle control device described in Patent Document 1 detects the slope of the road on which the vehicle travels, and determines whether or not to perform coasting according to the slope.

Japanese Patent No. 5304350

The vehicle control device described in Patent Document 1 is limited to the case where the amount of operation of the accelerator pedal by the driver is zero, and further determines whether or not to perform coasting using the slope of the road surface. If the conditions for coasting are limited in this way, the period during which coasting is possible is shortened, and the effect of improving fuel efficiency is limited.

The present invention has been made to solve the above problems, and a main object thereof is to provide a vehicle control device capable of improving fuel efficiency while traveling according to a driver's accelerator operation. is there.

The first invention is applied to a vehicle including an engine as a traveling drive source and a driving wheel connected to the engine so as to be able to supply a driving force, and the engine is applied to the vehicle when a predetermined implementation condition is satisfied while the vehicle is traveling. A vehicle control device that performs coasting to stop the supply of driving force to the drive wheels, and acquires an opening degree acquisition unit that acquires an accelerator opening degree indicating the amount of accelerator operation by the driver of the vehicle, and a vehicle speed. A driving control unit that obtains a threshold value for comparing the vehicle speed acquisition unit and the accelerator opening degree based on the acquired vehicle speed and performs coasting when the accelerator opening degree is smaller than the threshold value is provided. It is characterized by.

When traveling on a flat road, there is a correlation between the accelerator opening and the vehicle speed. Therefore, if the driver needs to maintain the vehicle speed, the accelerator opening according to the vehicle speed is maintained, and if the driver needs acceleration, the accelerator pedal is stepped on to increase the accelerator opening. If the road is uphill and the driver needs to maintain or accelerate the vehicle speed, the driver depresses the accelerator pedal more and more, so that the accelerator opening with respect to the vehicle speed increases. Further, if the road is a downward slope, the torque required to maintain the vehicle speed is reduced, so that the accelerator opening with respect to the vehicle speed is reduced. When the driver determines that acceleration is not necessary, the amount of depression of the accelerator pedal is reduced or the operation of the accelerator pedal is stopped. That is, in any of the driving situations, the driver increases the accelerator opening if he / she feels that the vehicle speed is slow, and decreases the accelerator opening if he / she feels that the vehicle speed is fast. Therefore, the driver determines that the vehicle speed is sufficient by setting a threshold value based on the relationship between the vehicle speed and the accelerator opening and performing coasting when the accelerator opening is smaller than the threshold value. Coasting can be done in some cases. Therefore, it is possible to improve fuel efficiency while following the driver's intention to operate.

In the second invention, in addition to the first invention, the travel control unit is characterized in that coasting is performed when the accelerator opening degree is decreasing.

When the driver depresses the accelerator pedal and the accelerator opening increases, it can be said that the driver indicates an intention to increase the vehicle speed. In the above configuration, since coasting is stopped on condition that the accelerator opening degree is increased, control can be performed according to the driver's intention.

A third aspect of the invention, in addition to the first or second invention, is characterized in that the threshold value is set based on a function indicating the correlation between the vehicle speed and the accelerator opening degree.

In general, the correlation between vehicle speed and accelerator opening can be expressed as a function. In this configuration, the threshold value for determining whether or not to perform coasting is also set based on the function indicating the correlation between the vehicle speed and the accelerator opening, so that the determination as to whether or not to perform coasting is accurate. It can be carried out.

In the fourth invention, in addition to any of the first to third inventions, a first threshold value and a second threshold value smaller than the first threshold value are provided as threshold values, and the accelerator opening degree is the first threshold value. If it is smaller than the second threshold value and above the second threshold value, coasting is performed with the engine speed as the idling speed, and if the accelerator opening is below the second threshold value, the supply of fuel to the engine is stopped and coasting is performed. It is characterized by doing.

If the driver is depressing the accelerator pedal, there is a possibility of acceleration by depressing the accelerator. In this configuration, when the accelerator opening is smaller than the first threshold value and is equal to or higher than the second threshold value, the engine speed is set to the idling speed, so that the driver accelerates with good responsiveness when the accelerator pedal is stepped on. be able to. In addition, if the driver does not depress the accelerator pedal, it is unlikely that the driver will immediately re-accelerate. In this configuration, when the accelerator opening degree is smaller than the second threshold value, the supply of fuel to the engine is stopped to perform coasting, so that fuel efficiency can be further improved.

In the fifth invention, in addition to any one of the first to fourth inventions, a rotation speed acquisition unit for acquiring the rotation speed of the output shaft of the engine is further provided, and the traveling control unit increases the vehicle speed and the amount of increase. At least one of the speed and the amount of increase in the number of revolutions is larger than the predetermined value, and at least one of the speed and the amount of decrease in the accelerator opening is smaller than the predetermined value. In some cases, it is characterized by carrying out coasting.

If the speed or amount of increase in engine speed is equal to or greater than a predetermined value and the speed or amount of increase in vehicle speed is greater than or equal to a predetermined value, the driver reduces the amount of depression of the accelerator pedal to reduce the accelerator opening. Even so, if the reduction speed or reduction amount is not more than a predetermined value, the acceleration state of the vehicle can be maintained. In this configuration, since coasting is performed when the above conditions are satisfied, coasting can be performed even when the vehicle is suddenly accelerated, and fuel efficiency can be improved.

The sixth invention is applied to a vehicle including an engine as a traveling drive source and drive wheels connected to the engine so as to be able to supply driving force, and from the engine to the drive wheels according to the establishment of predetermined implementation conditions. A vehicle control device that performs coasting to stop the supply of driving force, and includes an opening degree acquisition unit that acquires the accelerator opening degree, which indicates the amount of accelerator operation by the vehicle driver, and a vehicle speed acquisition unit that acquires the vehicle speed. , At least one of the rotation speed acquisition unit that acquires the rotation speed of the output shaft of the engine and the increase speed and the increase amount of the vehicle speed is larger than a predetermined value, and at least one of the increase speed and the increase amount of the rotation speed is a predetermined value. It is characterized by including a traveling control unit that performs coasting when at least one of the reduction speed and the reduction amount of the accelerator opening is smaller than a predetermined value in a state larger than the above.

The sixth invention has the same effect as the fifth invention.

In the seventh invention, in addition to any one of the first to sixth inventions, the engine and the drive wheels are connected via a clutch, and the traveling control unit is used to perform the coasting of the clutch. It is characterized by controlling the connection state.

With this configuration, when there is a high possibility that the driver will re-accelerate, it is possible to maintain the clutch engaged state and improve the responsiveness when the driver gives an instruction to re-accelerate. .. Further, when the road surface is on a downward slope, the clutch can be engaged to suppress unintended acceleration by the driver.

It is a schematic block diagram of a vehicle control system including a vehicle control device. It is a figure which shows the relationship between a vehicle speed and an accelerator opening degree. It is a flowchart which shows the process which the vehicle control device executes in 1st Embodiment. It is a time chart when the vehicle is suddenly accelerated. It is a flowchart which shows the process which the vehicle control device executes in 2nd Embodiment.

Hereinafter, each embodiment will be described with reference to the drawings. In each of the following embodiments, parts that are the same or equal to each other are designated by the same reference numerals in the drawings, and the description thereof will be incorporated for the parts having the same reference numerals.

<First Embodiment>
Hereinafter, an embodiment embodying the present invention will be described with reference to the drawings. In the present embodiment, in a vehicle provided with an engine as a running drive source, normal running in which the clutch is in a power transmission state and running in a coasting state (coasting running) in which the clutch is in a power cut state are selectively selected. It is supposed to be implemented.

In FIG. 1, the engine 10 is a multi-cylinder internal combustion engine driven by combustion of fuel such as gasoline or light oil, and is provided with a fuel injection valve, an ignition device, and the like as is well known. The engine 10 is provided with a starter motor 11. The rotating shaft of the starter motor 11 is drive-connected to the output shaft 12 of the engine 10. When the engine 10 is started, the rotation of the starter motor 11 gives the engine 10 an initial rotation (cranking rotation).

A transmission 14 is connected to the output shaft 12 of the engine 10 via a clutch 13. The clutch 13 is, for example, a friction type clutch, and is a disk (flywheel or the like) on the engine 10 side connected to the output shaft 12 of the engine 10 and a circle on the transmission 14 side connected to the input shaft 15 of the transmission 14. It is equipped with a set of clutch mechanisms having a plate (clutch disc, etc.). When both disks come into contact with each other in the clutch 13, a power transmission state is set in which power is transmitted between the engine 10 and the transmission 14, and when both disks are separated from each other, the engine 10 and the transmission are separated from each other. The power transmission to and from 14 is cut off, resulting in a power cutoff state. The clutch 13 of the present embodiment is configured as an automatic clutch that switches between a connected state and a disconnected state by an actuator such as a motor. The clutch 13 may be provided inside the transmission 14.

The transmission 14 is an automatic transmission having a plurality of transmission stages. The transmission 14 shifts the power of the engine 10 input from the input shaft 15 according to the vehicle speed, the engine speed, and the gear ratio according to the shift position, and outputs the power to the output shaft 16. The shift position is selected by the driver operating a shift lever (not shown) as a shift operation member provided in the driver's seat. In this system, a forward range (D range), a backward range (R range), and a neutral range (N range) are provided as shift positions. The transmission 14 is provided with an automatic shift mechanism including actuators such as a motor and a hydraulic device, and the shift stage is automatically switched in the D range, which is a traveling range. Drive wheels 19 are connected to the output shaft 16 of the transmission 14 via a differential gear 17 and a drive shaft 18.

This system includes an ECU 20 as a control device that controls the entire system, a clutch control device 21 that controls the clutch 13, and a transmission control device 22 that controls the transmission 14. The ECU 20, the clutch control device 21, and the transmission control device 22 are all well-known electronic control devices including a microcomputer and the like, and are engines based on the detection results of various sensors provided in this system. 10. Controls the clutch 13, the transmission 14, and the like. The ECU 20, the clutch control device 21, and the transmission control device 22 are connected to each other so as to be able to communicate with each other, so that control signals, data signals, and the like can be shared with each other. In the present embodiment, the "vehicle control device" is configured by the ECU 20, but the present invention is not limited to this, and the vehicle control device may be configured by the ECU 20, the clutch control device 21, and the transmission control device 22.

The ECU 20 is electrically connected to the battery 23 and operates by the electric power supplied from the battery 23. The battery 23 is connected to the starter motor 11 via a relay 24. The relay 24 is connected by the drive signal from the ECU 20, and power is supplied from the battery 23 to the starter motor 11.

The sensors include an accelerator sensor 32 that detects the amount of depression operation of the accelerator pedal 31 as an accelerator operation member, a brake sensor 34 that detects the amount of depression operation of the brake pedal 33, and a wheel speed sensor that detects the rotation speed of the drive wheels 19. 35. A rotation speed sensor 36 or the like for detecting the engine rotation speed, which is the rotation speed of the output shaft 12 of the engine 10 per hour, is provided. The detection signals from these sensors are sequentially input to the ECU 20. The ECU 20 acquires the depression operation amount of the accelerator pedal 31 detected by the accelerator sensor 32 as the accelerator opening degree. The rotation speed of the drive wheels 19 detected by the wheel speed sensor 35 is acquired by the ECU 20 as the vehicle speed. At this time, the ECU 20 functions as an opening degree acquisition unit in acquiring the accelerator opening degree, functions as a rotation speed acquisition unit in acquiring the engine rotation speed, and functions as a vehicle speed acquisition unit in acquiring the vehicle speed. .. Although the system is provided with sensors other than these sensors, the illustration is omitted.

The ECU 20 performs various engine controls such as fuel injection amount control by the fuel injection valve and ignition control by the ignition device based on the detection result of each sensor, transmission information from the transmission control device 22, and the like. The clutch control device 21 performs switching control between the connected state and the disengaged state of the clutch 13 based on the transmission information from the ECU 20. The transmission control device 22 performs transmission control of the transmission stage of the transmission 14 based on the transmission information from the ECU 20.

In the vehicle of the present embodiment, when a predetermined implementation condition is satisfied while the vehicle is being driven by the driving force from the engine 10, the clutch 13 can be disengaged to shift to coasting. By implementing such coasting, we are trying to improve fuel efficiency. At this time, the ECU 20 functions as a travel control unit. Further, in the present embodiment, as coasting, "first coasting" in which fuel is supplied to the engine 10, the rotation speed is set to the idling speed, and the clutch 13 is disengaged, and fuel supply to the engine 10 is performed. A "second coasting" that stops and disengages the clutch 13 is performed, and each of these coastings is selectively performed.

In performing this coasting, in the present embodiment, it is determined whether or not the implementation conditions are satisfied by using the accelerator opening degree detected by the accelerator sensor 32 and the vehicle speed detected by the vehicle speed sensor. The relationship between the accelerator opening and the vehicle speed will be described with reference to FIG.

When the vehicle travels on a flat road, the gear ratio of the transmission 14 is constant, and if the vehicle is not accelerating or decelerating, the accelerator opening with respect to a certain vehicle speed is a constant value. Therefore, the correlation between the accelerator opening degree and the vehicle speed can be approximated by the linear function F1 shown by the broken line in FIG. In FIG. 2, the gear ratio of the transmission 14 can be switched in 6 steps, and the tendency of the gear ratio changes at the point of 50 km / h, which is the vehicle speed for switching from the 3rd gear to the 4th gear. Therefore, the linear function F1 shown by the broken line changes the coefficient at the point where the vehicle speed is 50 km / h.

Therefore, if the detected accelerator opening is smaller than the accelerator opening obtained by the function at a certain vehicle speed, it can be said that the driver is not trying to accelerate the vehicle. Further, when the road surface on which the vehicle travels is an uphill slope and the driver tries to maintain the vehicle speed, the driver depresses the accelerator pedal 31. That is, if the driver determines that acceleration is necessary or is trying to maintain the vehicle speed, the acquired accelerator opening will be larger than the one corresponding to the vehicle speed, otherwise the accelerator opening will be larger. Is smaller than the one corresponding to the vehicle speed. When the road surface on which the vehicle travels is a downward slope, the acquired accelerator opening will be smaller than that corresponding to the vehicle speed unless the driver needs acceleration.

Therefore, in the present embodiment, the threshold value for the accelerator opening is obtained as a value smaller than the value indicating the relationship between the accelerator opening and the vehicle speed on a flat road. More specifically, the threshold value is calculated by combining a plurality of linear functions set according to the gear ratio. The linear function F2 indicating this threshold value is shown by a solid line in FIG. 2, and a value smaller than the actual correlation between the vehicle speed and the accelerator opening is calculated as the threshold value. Then, coasting is performed when the accelerator opening degree based on the driver's accelerator operation is equal to or less than the threshold value. That is, coasting is performed when it can be estimated that the driver has no intention of accelerating.

At this time, even while the driver is returning the depression of the accelerator pedal 31, if the accelerator opening is not zero, it can be said that the driver may restart the depression of the accelerator pedal 31. Therefore, when the accelerator opening degree is not zero, the fuel supply to the internal combustion engine is continued, and the first coasting, which is the coasting in the idle state, is performed. On the other hand, when the accelerator opening degree is zero, the supply of fuel to the internal combustion engine is stopped and the second coasting is performed. It takes time from the time when the driver finishes depressing the accelerator pedal 31 until the accelerator opening becomes zero. Therefore, instead of the condition that the accelerator opening degree is zero, the condition may be that the accelerator pedal 31 is not depressed.

Subsequently, a series of processes executed by the ECU 20 according to the present embodiment will be described with reference to the flowchart of FIG. The process according to the flowchart of FIG. 3 is repeatedly executed in a predetermined control cycle.

First, it is determined whether or not the vehicle speed is equal to or higher than the threshold value (S101). This threshold value is set in advance as a value for determining whether or not the vehicle speed allows coasting, and is set to several tens of km / h. If the vehicle speed is not equal to or higher than the threshold value (S101: NO), it means that the driver is trying to stop the vehicle, is driving slowly, etc., and it is not necessary to maintain the vehicle speed. To finish. If the vehicle speed is equal to or higher than the threshold value (S101: YES), it is determined whether or not the accelerator opening degree is increasing (S102).

In the process of S102, for example, the accelerator opening in the previous control cycle is compared with the accelerator opening acquired in the current control cycle, and if the accelerator opening acquired in the current control cycle is larger, the accelerator opening increases. Judge that it is. If the accelerator opening is increased, it can be said that the driver indicates the intention to accelerate the vehicle. Therefore, if it is determined that the accelerator opening degree is increasing (S102: YES), it is determined whether or not the coasting is in progress (S103). If the coasting is in progress (S103: YES), the coasting is stopped (S104), and the series of processes is terminated. If coasting is not in progress (S103: NO), the series of processes is terminated as it is.

If the accelerator opening degree has not increased (S102: NO), it is determined whether or not the rate of increase in engine speed is equal to or greater than a predetermined value (S105). That is, it is determined whether or not the vehicle is accelerating. In making the determination of S105, the vehicle can maintain the acceleration state even if the engine speed decreases once after it is determined that the increase speed of the engine speed is equal to or higher than a predetermined value. Therefore, if it is determined that the increase speed of the engine speed is equal to or higher than a predetermined value, the determination result is held for a predetermined control cycle.

If the rate of increase in engine speed is equal to or greater than a predetermined value (S105: YES), the vehicle is accelerating, and the accelerator opening is reduced in order to determine whether the driver is requesting further acceleration. It is determined whether or not the speed is equal to or higher than a predetermined value (S106). If the decreasing speed of the accelerator opening is equal to or greater than a predetermined value (S106: YES), it can be inferred that the driver has finished depressing the accelerator pedal 31 and is about to stop accelerating. Therefore, the first coasting is started (S107), and a series of processes is completed. On the other hand, when the decreasing speed of the accelerator opening is not equal to or higher than a predetermined value (S106: NO), there is a high possibility that the driver is trying to continue accelerating, so the series of processes is terminated as it is.

When the increase speed of the engine speed is not more than the predetermined value (S105: NO), that is, when the acceleration of the vehicle is small, or when the vehicle is running at a constant speed or decelerating, the accelerator operation by the driver is performed. The threshold value of the accelerator opening degree is calculated based on the acquired vehicle speed in order to determine whether or not indicates the intention of deceleration (S108). At this time, the threshold value based on FIG. 2 described above is obtained. Subsequently, the calculated threshold value is compared with the accelerator opening degree, and it is determined whether or not the accelerator opening degree is equal to or less than the threshold value (S109).

If the accelerator opening is not below the threshold value (S109: NO), the driver keeps the accelerator opening in order to drive the vehicle at a constant speed, or the driver is stepping on the accelerator on an uphill road. Etc. are assumed. In these cases, the vehicle should not be decelerated, so the series of processes is terminated as it is without coasting. If the accelerator opening degree is equal to or less than the threshold value (S109: YES), the driver determines whether or not the accelerator is ON (S110). In the determination of S110, as described in detail in the description of FIG. 2, it is determined whether or not the accelerator opening degree is zero, but it is determined by whether or not the operation amount of the accelerator pedal 31 is zero. May be good. If the accelerator is ON (S110: YES), the first coasting is performed (S111). On the other hand, if the accelerator is not ON (S110: NO), the second coasting is performed (S112).

When performing the second coasting, it is further determined whether or not the brake pedal 33 is depressed by the driver (S113). If the brake pedal 33 is depressed (S113: YES), it is determined whether or not the operation amount is equal to or greater than the threshold value (S114). If the amount of operation of the brake pedal 33 is equal to or greater than the threshold value (S114: YES), the driver needs a larger braking force and therefore stops coasting in order to apply the engine brake. On the other hand, when the brake pedal 33 is not depressed (S113: NO), or when the operation amount is smaller than the threshold value even if the brake is depressed (S113: YES, S114: NO), the driver The second coasting is performed because it does not require a large deceleration force.

If the accelerator opening is equal to or less than the threshold value before the previous control cycle (S109: YES) and the accelerator opening degree acquired in the current control cycle exceeds the threshold value in the state where coasting is started, S102 and S103 Will be judged positively and the coasting will be stopped. Further, if the processing of S107 or S111 is performed while the first coasting is being performed, the first coasting will be continued.

With the above configuration, the vehicle control device according to the present embodiment has the following effects.

-When driving on a flat road, there is a correlation between the accelerator opening and the vehicle speed. Therefore, if the driver needs to maintain the vehicle speed, the accelerator opening according to the vehicle speed is maintained, and if the driver needs acceleration, the accelerator pedal 31 is stepped on to increase the accelerator opening. .. If the road is an uphill slope and the driver needs to maintain or accelerate the vehicle speed, the driver depresses the accelerator pedal 31 more, so that the accelerator opening with respect to the vehicle speed increases. Further, if the road is a downward slope, the torque required to maintain the vehicle speed is reduced, so that the accelerator opening with respect to the vehicle speed is reduced. When the driver determines that acceleration is not necessary, the amount of depression of the accelerator pedal 31 is reduced or the operation of the accelerator pedal 31 is stopped. That is, in any of the driving situations, the driver increases the accelerator opening if he / she feels that the vehicle speed is slow, and decreases the accelerator opening if he / she feels that the vehicle speed is fast. Therefore, by setting a threshold value based on the relationship between the vehicle speed obtained by driving on flat ground and the accelerator opening, and performing coasting when the accelerator opening is smaller than the threshold value, the driver has sufficient vehicle speed. Coasting can be performed when it is determined that the value is. Therefore, it is possible to improve fuel efficiency while following the driver's intention to operate.

-When driving on a flat road, the correlation between vehicle speed and accelerator opening can be expressed by a linear expression. In the present embodiment, since the threshold value for determining whether or not to perform coasting is also set based on the linear equation showing the correlation between the vehicle speed and the accelerator opening, it is determined whether or not to perform coasting. It can be done with high accuracy.

-If the driver is stepping on the accelerator pedal 31, there is a possibility of acceleration by stepping on the accelerator. In the present embodiment, if the accelerator opening degree is equal to or less than the threshold value and the driver depresses the accelerator pedal 31, the first coasting that does not stop the supply of fuel to the engine 10 is performed. As a result, when the driver depresses the accelerator pedal 31 more, the vehicle can be accelerated with good responsiveness.

-If the driver does not depress the accelerator pedal 31, it is unlikely that the driver will immediately try to re-accelerate. In the present embodiment, when the driver does not step on the accelerator pedal 31 and the accelerator opening degree is zero, the second coasting for stopping the supply of fuel to the engine 10 is performed. By performing this second coasting, fuel efficiency can be further improved.

-When the driver steps on the brake pedal 33, it can be said that the driver is trying to decelerate the vehicle. In the present embodiment, the coasting is stopped on condition that the driver depresses the brake pedal 33, so that the engine brake can be applied when the driver intends to decelerate.

<Second Embodiment>
In the present embodiment, a part of the processing is added to the determination processing of whether or not to perform the coasting in the first embodiment.

FIG. 4 shows the vehicle speed, the number of revolutions of the engine 10, and the accelerator opening when the driver depresses the accelerator greatly to accelerate the vehicle suddenly. If the driver starts depressing the accelerator pedal 31 at time t1, the number of revolutions and the vehicle speed will increase accordingly. If the driver reduces the amount of depression of the accelerator pedal 31 at time t2, the number of revolutions also decreases accordingly. At this time, the transmission control device 22 controls the shift of the transmission 14. On the other hand, if the acceleration of the vehicle is sufficient at the time t2, the acceleration can be continued by the inertial force obtained at the time of acceleration. Then, if the driver increases the amount of depression of the accelerator pedal 31 at time t3, the acceleration increases. The same applies from time t4 to time t5.

At this time, if the driver performs coasting between time t2 and time t3 and between time t4 and time t5, which reduces the amount of depression of the accelerator pedal 31, fuel consumption is suppressed while suppressing adverse effects on vehicle acceleration. Can be expected to improve. Therefore, in the present embodiment, the course is performed when the vehicle speed increase speed is equal to or higher than a predetermined value, the rotation speed increase speed is equal to or higher than the predetermined value, and the accelerator opening reduction speed is lower than the predetermined value. Shall be tinged. The coasting in this case is the first coasting that maintains the engine speed at the idle speed.

FIG. 5 is a flowchart showing a series of processes executed by the ECU 20 according to the present embodiment. The process according to the flowchart of FIG. 5 is repeatedly executed in a predetermined control cycle.

Since the processes of S101 to S115 are the same as those of the first embodiment, the description thereof will be omitted. When it is determined that the speed of increase in the number of revolutions is equal to or higher than a predetermined value (S105: YES) and the speed of decrease in the accelerator opening is smaller than the predetermined value (S106: NO), the driver is trying to accelerate the vehicle. , There is a possibility that the accelerated state can be maintained even if the coasting is performed as shown in FIG. Therefore, in order to determine whether or not the acceleration state of the vehicle can be maintained even if coasting is performed, it is determined whether or not the increasing speed of the vehicle speed is equal to or higher than a predetermined value (S116). If the increasing speed of the vehicle speed is equal to or higher than a predetermined value, the acceleration state can be maintained even if the coasting is performed, so that the first coasting is performed (S117). On the other hand, if the increasing speed of the vehicle speed is not equal to or higher than the predetermined value, the series of processes is terminated as it is.

In the flowchart of the present embodiment, the processes of S108 to S115, which are the processes when the increase speed of the rotation speed is smaller than the predetermined value, are also described, but these processes are indispensable in the process of the present embodiment. Not a configuration.

With the above configuration, the vehicle control device according to the present embodiment has the following effects.

-If the increase speed of the engine 10 speed is equal to or higher than the predetermined value and the increase speed of the vehicle speed is equal to or higher than the predetermined value, even if the driver reduces the amount of depression of the accelerator pedal 31 to reduce the accelerator opening. If the reduction speed is equal to or less than a predetermined value, the acceleration state of the vehicle can be maintained. In the present embodiment, since the first coasting is performed when the above conditions are satisfied, the coasting can be performed even when the vehicle is suddenly accelerated, and the fuel efficiency can be improved.

<Modification example>
-In the first embodiment, the threshold value of the accelerator opening with respect to the vehicle speed is set by a combination of two linear functions, but it may be set by one linear function, or a combination of three or more linear functions. It may be provided by.

-The threshold value of the accelerator opening with respect to the vehicle speed in the first embodiment may be changed according to the shift stage of the transmission 14. That is, in the example shown in FIG. 2, since the gear ratio is changed in 6 steps, 6 linear functions having different coefficients may be combined and the threshold value may be calculated based on the linear function. Further, when the transmission 14 is a continuously variable transmission or the like, the threshold value may be set based on an approximate straight line or an approximate curve showing the relationship between the vehicle speed and the accelerator opening degree.

In the embodiment, the clutch 13 is provided between the output shaft 12 of the engine 10 and the transmission 14, and the clutch 13 is in the disengaged state during coasting. In this regard, a clutch 13 may be provided between the transmission 14 and the drive wheels 19, and the clutch 13 may be disengaged during coasting. In this case, since the drive wheels 19 are not connected to the transmission 14 during coasting, the traveling resistance can be further reduced.

-In the embodiment, the coasting is terminated when the brake operation amount is equal to or more than the threshold value, but the coasting is terminated when the increase amount of the brake operation amount per hour is equal to or more than the threshold value. May be good. Further, the coasting may be terminated on condition that at least one of the operation amount of the brake and the increase amount of the operation amount per hour is equal to or more than the threshold value.

-During coasting, if the brake operation is performed within a predetermined time after the accelerator opening becomes smaller than the predetermined value, the coasting may be stopped. In this case, it means that the driver stopped depressing the accelerator pedal 31 and immediately started the operation of the brake pedal 33. Therefore, by stopping the coasting, the engine brake can be applied and the deceleration can be performed according to the driver's intention.

-In the embodiment, the first coasting is performed when the accelerator opening is equal to or less than the threshold value and is larger than zero, and the second coasting is performed when the accelerator opening is zero. In this regard, a first threshold value and a second threshold value smaller than the first threshold value are provided as threshold values for the accelerator opening, and when the accelerator opening is equal to or less than the first threshold value and larger than the second threshold value, the first coasting is performed. If the accelerator opening is equal to or less than the second threshold value, the second coasting may be performed. When the threshold value is set as in the embodiment, the threshold value in the embodiment can be referred to as a first threshold value, and a value of zero can be referred to as a second threshold value.

In the second embodiment, the rate of increase of the vehicle speed, and the rate of increase of the rotational speed of the engine 10 has a condition for coasting that is above a predetermined value. In this regard, it may be determined whether or not coasting is performed by using the amount of increase in vehicle speed or the amount of increase in the number of revolutions of the engine 10 between before the predetermined control cycle and the control cycle for determining. Similarly, the determination may be made based on whether or not the amount of decrease in the accelerator opening degree is equal to or less than a predetermined value.

-In the first embodiment, the clutch 13 is in the disengaged state when coasting is performed, but the clutch 13 may be maintained in the connected state during coasting. When the vehicle travels on a downhill road, if the clutch 13 is disengaged, the driver may accelerate unintentionally. Therefore, when determining whether or not to perform coasting by comparing the accelerator opening and the threshold value, it is further determined whether or not the increasing speed of the vehicle speed tends to increase, and if the vehicle speed is increasing, the clutch is clutched. 13 may be connected to suppress a further increase in vehicle speed. Further, when there is a high possibility that the driver will re-accelerate, the clutch 13 can be maintained in a connected state, and the responsiveness when the driver gives an instruction for re-acceleration can be improved.

-When the driver takes his foot off the accelerator pedal 31 and immediately depresses the brake pedal 33, the brake sensor 34 may detect the brake operation before the accelerator opening becomes zero. In such a case, it can be said that the driver wants a sudden deceleration. Therefore, the time from the operation of reducing the accelerator opening of the driver to the start of depressing the brake pedal 33 may be timed, and if the time is equal to or less than a predetermined value, the process may not shift to coasting. By doing so, the engine brake can be applied when the driver desires a sudden deceleration, and control can be performed according to the driver's intention.

10 ... engine, 13 ... clutch, 19 ... drive wheels, 20 ... ECU.

Claims (5)

It is applied to a vehicle including an engine (10) as a traveling drive source and a drive wheel (19) connected to the engine via a clutch (13) so as to be able to supply a driving force, and is applied to a predetermined implementation during vehicle traveling. A vehicle control device (20) that performs coasting in which the clutch is turned off and the supply of driving force from the engine to the driving wheels is stopped when the conditions are satisfied.
An opening degree acquisition unit that acquires an accelerator opening degree indicating the amount of accelerator operation by the driver of the vehicle, and an opening degree acquisition unit.
The vehicle speed acquisition unit that acquires the vehicle speed,
A rotation speed acquisition unit that acquires the rotation speed of the output shaft of the engine, and
A threshold value for comparison with the accelerator opening degree is obtained so that the threshold value becomes larger as the acquired vehicle speed is faster, and when the accelerator opening degree is smaller than the threshold value, the coasting is started. 1 Travel control unit and
Wherein in reducing the accelerator opening degree, when at least one of the previous SL rotational speed-increasing acceleration and increase amount is determined to be greater than the predetermined value, during a predetermined control period, holds the determination result, the The course when at least one of the increase speed and the increase amount of the vehicle speed is larger than a predetermined value and at least one of the decrease speed and the decrease amount of the accelerator opening is smaller than the predetermined value during the holding period of the determination result. A vehicle control device including a second travel control unit that starts ting . As the threshold value, a first threshold value and a second threshold value smaller than the first threshold value are provided.
If the accelerator opening is smaller than the first threshold and is equal to or greater than the second threshold, the coasting is performed with the engine speed as the idling speed, and if the accelerator opening is equal to or less than the second threshold. The vehicle control device according to claim 1 , wherein the coasting is performed by stopping the supply of fuel to the engine. The vehicle control device according to claim 1 or 2 , wherein the traveling control unit performs the coasting when the accelerator opening degree is reduced. The vehicle according to any one of claims 1 to 3 , wherein the threshold value is set on the side where the accelerator opening is smaller than the function showing the correlation between the vehicle speed and the accelerator opening. Control device. It is applied to a vehicle provided with an engine (10) as a traveling drive source and a drive wheel (19) connected to the engine via a clutch (13) so as to be able to supply a driving force, and the predetermined implementation conditions are satisfied. A vehicle control device (20) that performs coasting in which the clutch is turned off and the supply of driving force from the engine to the driving wheels is stopped accordingly.
An opening degree acquisition unit that acquires an accelerator opening degree indicating the amount of accelerator operation by the driver of the vehicle, and an opening degree acquisition unit.
The vehicle speed acquisition unit that acquires the vehicle speed,
A rotation speed acquisition unit that acquires the rotation speed of the output shaft of the engine, and
Wherein in reducing the accelerator opening degree, when at least one of the previous SL rotational speed-increasing acceleration and increase amount is determined to be greater than the predetermined value, during a predetermined control period, holds the determination result, the The course when at least one of the increase speed and the increase amount of the vehicle speed is larger than a predetermined value and at least one of the decrease speed and the decrease amount of the accelerator opening is smaller than the predetermined value during the holding period of the determination result. A vehicle control device including a traveling control unit that starts ting .