JP7108481B2 - Drowsy driving prevention driving control method and vehicle driving control device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle travel control device for preventing drowsy driving in an automobile, and more particularly to a device designed to simplify the configuration and improve versatility.

It is well known that automobiles, in which the operation of the internal combustion engine is electronically controlled, take various accident and safety measures from the viewpoint of preventing automobile accidents and ensuring safe vehicle travel. It is as it is.
Drowsy driving can be cited as one of the major causes of automobile accidents, and various measures have been proposed and put into practical use from the viewpoint of preventing the occurrence of automobile accidents due to drowsy driving.

For example, when the possibility of the driver falling asleep or the driver's dozing off is detected, a device etc. has been proposed and put into practical use that attempts to prevent accidents by tightening the seat belt to wake up the driver (for example, patent documents 1st prize).

JP-A-60-15240

However, in the above-described conventional device, although it is possible to ensure the awakening of the driver by tightening the seat belt, the seat belt is automatically tightened when the possibility of falling asleep or when dozing is detected. The configuration requires a driving device for this purpose. Therefore, in order to apply this drowsy driving prevention device to an existing vehicle, not only is it necessary to add a new driving device for tightening the seat belt, but there are various problems such as securing the installation space. Therefore, it is practically difficult, and there is a problem that the device lacks versatility and the degree of freedom in installation and use is low.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a highly versatile vehicle travel control apparatus which has a simple configuration, can reliably prevent doze off driving, can be retrofitted to existing vehicles, and has high versatility. .

In order to achieve the object of the present invention, a drowsy driving prevention cruise control method according to the present invention includes:
A driving control method for preventing drowsy driving, wherein when the possibility of drowsy driving or drowsy driving is detected, the torque of the engine is varied to generate vibrations of the vehicle to awaken the driver,
Increase/decrease of the fuel injection amount in inter-cylinder control for increasing/decreasing the fuel injection amount so that the average value of the fuel amount injected to each cylinder in the idling state becomes substantially the same when the vehicle is stopped in the idling state. By changing the amount to an amount that causes variations in the average value of the fuel amount injected to each cylinder and executing the inter-cylinder control, fluctuations in the torque of the engine are generated . .
Further, in order to achieve the object of the present invention, the vehicle travel control device according to the present invention includes:
A vehicle travel control device having an electronic control unit configured to be capable of executing vehicle operation control and configured to be capable of controlling travel of the vehicle,
The electronic control unit is
When the possibility of drowsy driving or the detection signal of drowsy driving is input, the engine torque is varied to generate vibrations of the vehicle, thereby awakening the driver. When the vehicle is stopped in an idling state, inter-cylinder control can be executed to increase or decrease the fuel injection amount so that the average value of the fuel amount injected to each cylinder in the idling state becomes substantially the same,
By executing the inter-cylinder control by changing the increase/decrease amount of the fuel injection amount in the inter-cylinder control to an amount that causes the variation in the average value of the fuel amount injected to each cylinder, the torque of the engine fluctuates. is configured to generate

ADVANTAGE OF THE INVENTION According to the present invention, it is possible to reliably prevent drowsy driving with a simple configuration without requiring additional parts or devices for awakening the driver, and furthermore, it can be retrofitted to existing vehicles. Therefore, it is possible to provide a highly versatile vehicle travel control device.

1 is a configuration diagram showing a configuration example of a vehicle travel control device according to an embodiment of the present invention; FIG. 4 is a subroutine flow chart showing the procedure of a doze-driving prevention cruise control process executed by the vehicle cruise control device according to the embodiment of the present invention; FIG. 3A is a characteristic diagram showing an example of characteristics of change in engine speed with accelerator operation, and FIG. 3A is a characteristic diagram showing an example of characteristics of change in engine speed with accelerator operation without driving system vibration control. FIG. 3B is a characteristic diagram showing an example of the change characteristic of the engine speed accompanying the accelerator operation when the conventional drive system vibration control is executed. FIG. 4A is a characteristic diagram showing an example of engine speed fluctuation characteristics in an idling state, and FIG. 4A is a characteristic diagram showing an example of engine speed fluctuation characteristics in an idling state without inter-cylinder control FIG. 4B is a characteristic diagram showing an example of fluctuation characteristics of the engine speed in the idling state when the conventional inter-cylinder control is executed.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. FIG.
The members, arrangement, etc., described below do not limit the present invention, and can be modified in various ways within the spirit and scope of the present invention.
First, the configuration of the vehicle travel control system according to the embodiment of the present invention will be described with reference to FIG.
A vehicle travel control system according to the embodiment of the present invention is configured with an electronic control unit 100 mounted on a vehicle 300 as a main component.
This electronic control unit 100 is configured to be able to execute operation control of an engine 200 as an internal combustion engine, and itself is basically installed in a conventional automobile capable of electronic control. is identical to

That is, the electronic control unit 100 according to the embodiment of the present invention executes various controls necessary for vehicle travel control, such as rotation control of the engine 200 and fuel injection control of a fuel injection valve (not shown), as in the conventional art. It is assumed that it is configured to be possible.
Furthermore, in the electronic control unit 100 according to the embodiment of the present invention, existing controls that enable torque control of the engine 200, such as inter-cylinder control, drive system vibration control, and idle governor control, are appropriately selected and executed. Assuming it is possible. The specific contents of inter-cylinder control, drive system vibration control, and idle governor control will be described later.

The electronic control unit 100 includes, for example, a microcomputer having a well-known configuration, storage elements such as RAM and ROM (not shown), and an input/output interface circuit (not shown). is configured as a main component.

The electronic control unit 100 receives various signals necessary for vehicle operation control detected by sensors (not shown), such as atmospheric pressure, engine speed, accelerator opening, engine cooling water temperature, and the like. It is used for injection control and the like.
Further, the electronic control unit 100 according to the embodiment of the present invention is externally input with a detection signal indicating the possibility of the driver falling asleep or a driver falling asleep detection signal. The possibility of the driver falling asleep or the method of detecting the driver falling asleep will be described later.

FIG. 2 shows a subroutine flowchart showing the procedure of the drowsy driving prevention running control process according to the embodiment of the present invention, which is executed by the electronic control unit 100. The details of the subroutine will be described below with reference to FIG. explain.
When the processing by the electronic control unit 100 is started, it is first determined whether or not a doze detection signal has been input (see step S100 in FIG. 2).
Here, the drowsy detection signal includes both a detection signal when the possibility of drowsy driving is detected and a detection signal when drowsy driving is detected, and these detection signals are input from an external device. It is a thing.

Here, the possibility of drowsy driving or the detection of drowsy driving will be described.
It is well known that various technologies and devices have already been proposed and put into practical use to detect the possibility of a driver falling asleep or dozing (hereinafter referred to as "drowsiness detection technology" for convenience of explanation). As is known.
On the other hand, the dozing detection technique or device to be used does not directly affect the execution of the drowsy driving prevention cruise control process in the embodiment of the present invention. It is not limited to devices.

As a specific dozing detection measure, for example, there is a technique of detecting the pupil using infrared rays and determining whether or not there is a possibility of dozing off from the degree of opening of the pupil. There is also a technology that detects the driver's heartbeat and detects the possibility of falling asleep or the fact that he is falling asleep based on changes in the heartbeat. Furthermore, a technique of detecting changes in the driver's eyes and eyelids using a camera and detecting dozing off based on the detection results is relatively well known.

Thus, if it is determined in step S100 that the doze detection signal has been input (in the case of YES), the process proceeds to step S110, which will be described below.
On the other hand, when it is determined that the doze detection signal has not been input (in the case of NO), there is no need to execute the subsequent series of processing, so the processing is temporarily terminated and the process returns to the main routine (not shown). becomes. In the main routine (not shown), this series of processes is started again after executing other processes.

In step S110, it is determined whether or not vehicle 300 is running.
In step S110, when it is determined that vehicle 300 is running (in the case of YES), the process proceeds to step S120.
On the other hand, if it is determined that the vehicle 300 is not running (NO), that is, if the vehicle is stopped and idling, the process proceeds to step S130.

In step S120, a notification process is executed together with execution of the special vehicle vibration mode.
As will be described later, the special vehicle vibration mode uses the existing driveline vibration control to generate vibrations in the vehicle 300, thereby awakening the driver.
The existing drive system vibration control, which is the premise of the embodiment of the present invention, smoothes the fluctuations in the engine speed that occur when the accelerator (not shown) is depressed and released to improve comfort. It is.

For example, FIG. 3(A) shows a characteristic line showing an example of the fluctuation characteristics of the engine speed when the accelerator is operated without the above drive system vibration control. drive system vibration control will be described.
In the figure, the section indicated by the two-dot chain line arrow is the section in which the engine speed increases in response to the depression of the accelerator, and the section indicated by the dotted arrow is the section in which the accelerator is released. This is a section in which the engine speed is low. Note that the horizontal axis represents the measurement time.

When the engine speed increases or when the engine speed decreases, the engine speed does not rise or fall linearly, but repeats rising and falling in a relatively short period. While, that is, it is normal to rise or fall as a whole while accompanied by fluctuations.
Such fluctuations in the engine speed are uncomfortable for the driver and passengers, and are preferably eliminated from the viewpoint of improving the comfort and marketability of the vehicle 300 .

The drive system vibration control controls the amount of fuel injection to suppress or reduce the fluctuations in the engine speed, thereby smoothing the increase or decrease in the engine speed. When such drive system vibration control is executed, the change in the engine speed as shown in FIG. It eliminates the discomfort of the driver and passengers, as described above, and ensures comfortable driving.

As described above, the optimum control constants for drive system vibration control are usually set based on test results, simulation results, etc., in order to smooth fluctuations in the engine speed.
In the special vehicle vibration mode according to the embodiment of the present invention, the above-mentioned control constants in the drive system vibration control are intentionally changed to settings that cause fluctuations in the engine speed as shown in FIG. In other words, the level of smoothing of the fluctuations in the engine speed is changed to a rough setting, and the vehicle 300 is vibrated to awaken the driver.

The control constants are preferably determined based on test results, simulation results, etc., in consideration of the specific specifications of the vehicle 300, the appropriate magnitude of vibrations that promote awakening of the driver, and the like.

As described above, the special vehicle vibration mode is executed and the notification process is performed.
That is, the notification process is intended to make the driver aware that the vibration of the vehicle generated by the special vehicle vibration mode is not due to the abnormal operation of the engine 200, but that it is possible that he/she is dozing off while driving. It is an action to let the driver know that it is a thing.

Specifically, for example, there is a method of turning on a display lamp on a dashboard (not shown) of the vehicle 300 . In this case, it is preferable to use an existing indicator lamp and, for example, light it in a specific lighting pattern so that the driver can recognize that it is a notification operation.
In recent years, some instrument panels are equipped with a liquid crystal display element that enables the display of characters, figures, etc., and software processing on the liquid crystal display element allows the possibility of drowsy driving or the possibility of drowsy driving. It is preferable to employ a method such as flashing a specific character or graphic to indicate that.

In addition, the execution time of special vehicle vibration mode and information is arbitrary.
That is, it may be terminated after a predetermined period of time has elapsed, or it may be continued until a so-called reset operation using a specific switch on the instrument panel (not shown) or the like is performed.
After the special vehicle vibration mode and the notification are executed, the process returns to the main routine (not shown).

On the other hand, in step S130, a special idling mode and notification processing are executed.
The special idling mode process is intended to awaken the driver by generating vibrations of the vehicle 300 in the idling state as described below.
In the embodiment of the present invention, it is assumed that the electronic control unit 100 is capable of executing existing inter-cylinder control in order to execute the special idling mode.

Here, the existing inter-cylinder control process will be described.
The inter-cylinder control process is executed in the idling state, and due to variations (non-uniformity) in injection characteristics of each fuel injection valve (not shown) and differences in injection characteristics caused by aging, This is done in order to reduce or suppress fluctuations in the engine speed caused by fluctuations in the amount of fuel injected (not shown).

For example, FIG. 4A shows a characteristic line showing an example of engine speed variation characteristics in an idling state when there is no inter-cylinder control process. Inter-cylinder control will be described.
In the case of the characteristic example shown in the figure, the fluctuation width of the engine speed is approximately 20 rpm. Note that the horizontal axis in FIG. 4 represents the measurement time.
Although there are individual differences, such fluctuations in engine speed are never comfortable for drivers and passengers, and often cause discomfort.

Therefore, the existing inter-cylinder control process increases or decreases the fuel injection amount so that the average value of the fuel amount injected to each cylinder is approximately the same, thereby reducing the above-mentioned fluctuations in the engine speed. It is suppressed.
When such inter-cylinder control is executed, the amount of fluctuation in engine speed during idling is suppressed to approximately 3 rpm, for example, as shown in FIG. Holding is almost non-existent.

In the special idling mode process according to the embodiment of the present invention, the increase/decrease amount of the fuel injection amount of each fuel injection valve in the inter-cylinder control described above is intentionally set to an amount that causes variation in the average value of the fuel amount injected to each cylinder. , and as shown in FIG. 4A, unlike the normal inter-cylinder control process (see FIG. 4B), the engine speed is varied to awaken the driver. It is a plan.
The increase/decrease amount of the fuel injection amount is preferably determined based on test results, simulation results, etc., taking into consideration the specific specifications of the vehicle 300, the amount of fluctuation in the engine speed that is appropriate for prompting the awakening of the driver, and the like. .

The special idling mode process is executed as described above, and the notification process is also performed.
Since the notification process is basically the same as that described in step S120, detailed description thereof will be omitted here.

In the above-described embodiment of the present invention, as the special vehicle vibration mode control and the special idling mode control, the existing drive system vibration control and the existing inter-cylinder control are used, but they are not necessarily limited to this configuration. No need.
Drive system vibration control and inter-cylinder control are common in that they both control engine torque, and if it is an existing control that can change engine torque within a desired range in this way, special vehicle vibration mode control and special idling mode control.

For example, there is an existing control commonly referred to as idling governor control that can be used for special idling mode control.
This idling governor control smoothes fluctuations in the engine speed during idling so that the engine speed can be maintained in the vicinity of the target idling speed.

Usually, feedback control based on PID control is used in idling governor control, and the smoothing of the fluctuation amount of the engine speed is performed by appropriately selecting a suitable value for the PID constant in PID control. It's becoming
Therefore, when the idling governor control is used for the special idling mode control, the setting of the PID constant is changed so that the level of smoothing becomes rough, thereby causing an appropriate fluctuation in the engine speed and allowing the driver to It is possible to awaken the

The present invention can be retrofitted to existing vehicles, has high versatility, and can be applied to a vehicle travel control device for which reliable prevention of drowsy driving is desired with a simple configuration.

100... Electronic control unit 200... Engine

Claims (6)

A driving control method for preventing drowsy driving, wherein when the possibility of drowsy driving or drowsy driving is detected, the torque of the engine is varied to generate vibrations of the vehicle to awaken the driver,
Increase/decrease of the fuel injection amount in inter-cylinder control for increasing/decreasing the fuel injection amount so that the average value of the fuel amount injected to each cylinder in the idling state becomes substantially the same when the vehicle is stopped in the idling state. drowsy driving prevention, characterized in that fluctuations in the engine torque are generated by changing the fuel injection amount to an amount that produces variations in the average value of the fuel amounts injected into the cylinders and executing the inter-cylinder control. travel control method. A driving control method for preventing drowsy driving, wherein when the possibility of drowsy driving or drowsy driving is detected, the torque of the engine is varied to generate vibrations of the vehicle to awaken the driver,
In idling governor control for smoothing fluctuations in the engine speed and maintaining the engine speed in the vicinity of a target idling speed when the vehicle is in an idling state and stopped, the amount of fluctuation in the engine speed is smoothed. The PID constant in the PID control used for smoothing is changed to a setting that roughens the smoothing level of the fluctuation amount of the engine speed, and the idling governor control is executed to generate fluctuations in the torque of the engine. A running control method for preventing drowsy driving, characterized by: The smoothing control constant for setting the smoothing level in the drive system vibration control for smoothing fluctuations in the engine speed that occur when the accelerator is depressed or released while the vehicle is running. 1 or 2, characterized in that fluctuations in the torque of the engine are generated by changing the setting to roughen the level of the driving system vibration control and executing the drive system vibration control. Method. A vehicle travel control device having an electronic control unit configured to be capable of executing vehicle operation control and configured to be capable of controlling travel of the vehicle,
The electronic control unit is
When the possibility of drowsy driving or the detection signal of drowsy driving is inputted, the torque of the engine is varied to generate vibrations of the vehicle, thereby awakening the driver, wherein the vehicle is in an idling state and the vehicle is stopped, inter-cylinder control can be executed to increase or decrease the fuel injection amount so that the average value of the fuel amount injected into each cylinder in the idling state becomes substantially the same,
By executing the inter-cylinder control by changing the increase/decrease amount of the fuel injection amount in the inter-cylinder control to an amount that causes the variation in the average value of the fuel amount injected to each cylinder, the torque of the engine fluctuates. A vehicle travel control device characterized in that it is configured to generate A vehicle travel control device having an electronic control unit configured to be capable of executing vehicle operation control and configured to be capable of controlling travel of the vehicle,
The electronic control unit is
When the possibility of drowsy driving or the detection signal of drowsy driving is inputted, the torque of the engine is varied to generate vibrations of the vehicle, thereby awakening the driver, wherein the vehicle When the vehicle is stopped in an idling state, idling governor control can be executed to smooth the fluctuation of the engine speed and maintain the engine speed near the target idling speed,
In the idling governor control, the PID constant in the PID control used for smoothing the fluctuation amount of the engine speed is changed to a setting that roughens the smoothing level of the fluctuation amount of the engine speed, and the idling governor control is performed. A vehicle running control device characterized by being constructed so as to generate fluctuations in the torque of the engine when executed. The electronic control unit is
When the vehicle is running, it is possible to execute drive system vibration control that smoothes fluctuations in engine speed that occur when the accelerator is depressed or released,
By changing the control constant for setting the smoothing level in the drive system vibration control to a setting that roughens the smoothing level and executing the drive system vibration control, fluctuations in the torque of the engine can be generated. 6. A vehicle travel control device according to claim 4 or 5, characterized in that it is constructed as follows.

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