JP2002213269A - Automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the increase of uneasiness of a driver when brake control is actuated. SOLUTION: When traction control or the brake control of an antilock brake system or brake assist is actuated, a brake control actuation determination flag FB is set at a value of one (Step S104), and thereafter until a preset releasing condition is satisfied for each brake control (Step S108), the implementation of an automatic stop/start process (Step S112) for the engine is prohibited. Thereby, the uneasiness of the driver in actuation of the brake control can be prevented from being increased by the automatic stop of the engine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile, and more particularly, to a slip control means for performing a slip control of a wheel, a brake assist control means for performing a brake assist control, and an operation of an internal combustion engine when a predetermined stop condition is satisfied. The present invention relates to an automobile having automatic stop control for automatically stopping the internal combustion engine and automatic start control for starting the internal combustion engine when a predetermined start condition is satisfied.

[0002]

2. Description of the Related Art Conventionally, an automobile of this type automatically activates an internal combustion engine when predetermined stop conditions such as a stopped state of a vehicle, a non-travel position of a shift lever, and a brake boost negative pressure equal to or higher than a predetermined negative pressure are satisfied. Various types have been proposed that automatically stop the internal combustion engine when predetermined starting conditions, such as stopping and releasing the parking brake, operating the shift lever to the traveling position, reducing the brake boost negative pressure, and starting the vehicle, are satisfied. ing. In addition, for stable running of the vehicle, traction control for suppressing the slip of the drive wheels that may occur when the output is applied to the drive wheels, an anti-lock brake system for suppressing the slip of the wheels during sudden braking, Many vehicles have been proposed which perform various brake-related controls such as brake assist for assisting a brake boost negative pressure when the operator suddenly brakes. Many automobiles that perform the above-described automatic stop and automatic start of the internal combustion engine also perform such various brake-related controls.

[0003]

Each of the brake-related controls basically controls the driving force of the wheels, and is equivalent to controlling the torque of the drive shaft. For this reason, if the internal combustion engine is stopped while performing various controls related to the brake, the torque output to the drive shaft fluctuates,
This is not preferable for controlling the driving force of the driving shaft. Further, since the brake-related controls are performed for unexpected behavior of the vehicle of the driver, the driver often has anxiety. Therefore, when the internal combustion engine is automatically stopped when the brake-related controls are operating or immediately after the operations of the respective controls are canceled, the feeling of anxiety felt by the driver is often increased.

An object of the present invention is to automatically stop an internal combustion engine under more appropriate conditions. Another object of the present invention is to eliminate anxiety of a driver.

[0005] The applicant has proposed, as one of the techniques for solving a part of the above-mentioned problems, a technique for prohibiting the automatic stop of the internal combustion engine when various brake-related controls are operating. (Japanese Patent Application No. 9-279586).

[0006]

Means for Solving the Problems and Actions and Effects Thereof The vehicle of the present invention employs the following means in order to achieve at least a part of the above objects.

The vehicle of the present invention has a slip control means for performing wheel slip control and / or a brake assist control means for performing brake assist control, and an automatic stop for automatically stopping the operation of the internal combustion engine when a predetermined stop condition is satisfied. An automatic stop / start control means for performing control and automatic start control for starting the internal combustion engine when a predetermined start condition is satisfied, wherein the slip control and / or the brake assist control are operated. The gist of the present invention is to include an automatic stop control prohibiting unit that prohibits the automatic stop control by the automatic stop and start control unit until a predetermined release condition is satisfied, regardless of whether the predetermined stop condition is satisfied.

In the vehicle of the present invention, when the slip control or the brake assist control is activated, the automatic stop control of the internal combustion engine is prohibited until the predetermined release condition is satisfied, regardless of whether the predetermined stop condition is satisfied. An increase in the driver's anxiety can be suppressed. That is, it is possible to automatically stop the internal combustion engine under more appropriate conditions.

In the vehicle of the present invention, when the traction control as the slip control is activated, the automatic stop control prohibiting means sets the automatic stop as a predetermined release condition when the vehicle is running at a predetermined vehicle speed or more for a predetermined time. It may be a means for prohibiting control.

Further, in the automobile according to the present invention, the automatic stop control prohibiting means changes the shift position to the non-traveling position, travels at a predetermined vehicle speed, when the antilock brake system as the slip control is operated. The means for inhibiting the automatic stop control may be at least one of the release of the brake pedal as the predetermined release condition.

Further, in the automobile according to the present invention, the automatic stop control prohibiting means includes, when the brake assist control is operated, a change of a shift position to a non-traveling position, a traveling at a predetermined vehicle speed, and a release of a brake pedal. May be a means for prohibiting the automatic stop control using at least one of the predetermined release conditions.

Further, the vehicle according to the present invention has an automatic stop control for automatically stopping the operation of the internal combustion engine when a predetermined stop condition is satisfied, and an automatic start for starting the internal combustion engine when a predetermined start condition is satisfied. Control, when the locked state of the wheel is detected, or when traveling on a low μ road with a low friction coefficient, the automatic stop control is prohibited until a predetermined release condition is satisfied. I do.

As described above, the automatic stop control of the internal combustion engine is prohibited on the low μ road when the locked state of the wheel is detected or the predetermined release condition is satisfied regardless of whether the predetermined stop condition is satisfied. . Therefore, it is possible to suppress an increase in the driver's anxiety. That is, it is possible to automatically stop the internal combustion engine under more appropriate conditions.

It is preferable that a vehicle speed detecting means for detecting a running speed of the vehicle is provided, and the release condition is that a predetermined time has elapsed since the vehicle speed became zero.

[0015] It is preferable that the predetermined time is variable according to a moving state of the vehicle. Further, it is preferable that the predetermined time is set according to the state of the wheel lock or the state of the road surface μ.

[0016]

Next, embodiments of the present invention will be described with reference to examples. FIG. 1 is a configuration diagram mainly showing a vehicle control electronic control unit (hereinafter, referred to as a vehicle control ECU) 30 schematically showing a configuration of an automobile 20 according to one embodiment of the present invention. The vehicle 20 of the embodiment is, as shown in FIG.
An engine control unit (hereinafter, referred to as an engine control unit) based on the traveling state of the vehicle such as the position SP of the shift lever 42 and the vehicle speed V.
An engine 46 whose operation is controlled by an engine ECU 44, a transmission 48 that changes the rotational power from the engine 46 and outputs it to a drive shaft (not shown),
The belt 5 is connected to the output shaft of the engine 46 via the clutch 50.
2, a generator motor 54 for generating electric power using a part of the power of the engine 46 and motoring the engine 46, a 36V high-voltage battery 58 for exchanging electric power with the generator motor 54 via an inverter 56,
The engine is powered by the 12 V low voltage battery 62 connected to the high voltage battery 58 via the C-DC converter 60 and the power from the low voltage battery 62 supplied via the relay 64 which is turned on based on the ignition switch IG and the starter switch ST. A starter motor 66 for cranking 46, a steering angle θ of a steering 68 and a wheel speed V
w, AB based on the brake negative pressure BP of the brake booster 70, the hydraulic pressure MCP of the brake master cylinder 72, etc.
An electronic control unit for chassis (hereinafter referred to as chassis ECU) 76 that drives each brake control such as traction control, antilock brake system, and brake assist by driving the S / TRC actuator 74
And a meter display section 78 arranged on an instrument panel in front of the driver's seat.

The vehicle control ECU 30 is configured as a microprocessor centered on a CPU 32. The ROM 34 stores a processing program, the RAM 36 temporarily stores data, a communication port (not shown),
An input / output port (not shown). The vehicle control ECU 30 communicates data related to the operation of the engine 46 such as the engine speed, and control signals related to start and stop of the engine 46 such as an engine stop request and permission for automatic stop and start of the engine with the engine ECU 44 via a communication port. are doing. Further, the vehicle control ECU 30 transmits control signals such as data relating to the brake control such as the steering angle θ and the hydraulic pressure MCP of the brake master cylinder 72 and control signals such as an operation signal of the brake control to the chassis ECU 76 via a communication port.
Communicating with The input ports of the vehicle control ECU 30 include charge / discharge current i from an ignition switch IG and a current sensor 59 attached to a high-voltage battery 58, a brake negative pressure BP of a brake booster 70, and a vehicle speed V from a meter display section 78. The starter switch ST and the meter display section 78 are input from the output port.
Lighting signals for a lamp group such as a warning lamp fitted into the lamp are output.

Although not shown, the engine ECU 44
The chassis ECU 76, like the vehicle control ECU 30, is also configured as a microprocessor centered on a CPU.

Next, the operation of the automobile 20 of the embodiment configured as described above, particularly, the operation in the automatic stop / start control of the engine 46 will be described. FIG. 2 shows an automobile 2 according to the embodiment.
5 is a flowchart illustrating an example of an automatic stop / start control routine executed by a vehicle control ECU 30 of FIG. This routine is repeatedly executed every predetermined time (for example, every 8 msec).

When the automatic stop / start control routine is executed, the CPU 32 of the vehicle control ECU 30 first executes a process of inputting various data and control signals that can be input through the respective communication ports and the input ports (step). S10
0). Then, based on a control signal input by communication from the chassis ECU 76, it is determined whether or not each brake control such as traction control, anti-lock brake system, and brake assist is operating (step S102). When any of the brake controls is operating, the value 1 is set to the brake control operation determination flag FB (step S104), and the routine ends without executing the automatic stop / start processing of the engine 46.

When none of the brake controls is operating, the value of the brake control operation determination flag FB is checked (step S106).
When B is equal to 0, an automatic stop / start process of the engine 46 is executed (step S112), and this routine ends. As the automatic stop / start process of the engine 46, for example, when the shift lever 42 is in the P, N range or D range and the brake pressure is large while the vehicle is stopped, the brake boost negative pressure B
When a predetermined stop condition such as when P is sufficient is established, the connection by the clutch 50 is released to stop the operation of the engine 46, the release of the brake is started, or the shift lever 42 is operated to the travel range. When a predetermined starting condition such as a decrease in the brake boost negative pressure BP is satisfied, the clutch 50 is connected and the generator motor 5 is connected.
4 to start the engine 46. Note that the predetermined stop conditions and the predetermined start conditions illustrated here are merely examples, and it is needless to say that various conditions can be set.

When any of the brake controls is operated, a value 1 is set to a brake control operation determination flag FB. In this case, in step S106, the brake control operation determination flag FB is determined to be 1 and it is determined whether or not the release condition is satisfied (step S108). If the release condition is not satisfied, the engine 46 is automatically stopped. This routine ends without executing the start processing. The release condition is a condition for releasing the prohibition of the automatic stop processing of the engine 46. For example, when the traction control is activated, a predetermined time at a predetermined vehicle speed can be cited as the release condition. When the system or the brake assist is operated, running conditions at or above a predetermined vehicle speed, when the shift lever 42 is operated in the P or N range, when the brake pedal is released, and the like can be cited as release conditions. Note that the release conditions when the traction control is activated and the anti-lock brake system and the brake assist are activated are only examples, and various conditions can be set. As described above, even after one of the brake controls is activated, the automatic stop / start process of the engine 46 is not performed until the release condition is satisfied. Further increase due to the automatic stop of the engine 46 can be prevented.

If it is determined in step S108 that the release condition is satisfied, the brake control operation determination flag FB is reset to a value of 0 (step S110), and an automatic stop / start process of the engine 46 is executed (step S110). Step S11
2) This routine ends.

According to the vehicle 20 of the embodiment described above, a predetermined value can be obtained even during or after any one of the traction control, the antilock brake system, and the brake assist is activated. Since the execution of the automatic stop / start processing of the engine 46 is prohibited until the release condition is satisfied, the anxiety felt by the driver due to the operation of the brake control is prevented from being further increased by automatically stopping the engine 46. be able to. That is, the automatic stop / start processing of the engine 46 can be performed more appropriately.

In the automobile 20 of the embodiment, when any one of the traction control, the antilock brake system, and the brake assist is operated, the automatic stop / start processing of the engine 46 is performed until a predetermined release condition is satisfied. However, if the vehicle does not execute any of the traction control, anti-lock brake system, and brake assist brake control, the following shall apply to those excluding the brake control that does not execute. Good.

FIG. 3 shows another embodiment of the automatic stop / start control. In this example, the automatic stop control is changed by detecting the locked state of the wheels.

First, an anti-lock brake system (A
BS) is operating (step 200).
If the determination in step 200 is NO, this control is unnecessary and the process does not proceed, and the determination in step 200 is repeated. If the determination in S200 is YES, it is determined whether the brake pressure is large (step 202). In this judgment,
If NO, the delay of the automatic stop control is unnecessary, and the process returns to step 200.

If the determination in step 202 is YES,
ABS is operating and brake pressure is high. Therefore, it is determined that the wheel lock has occurred, and the vehicle may not be stopped even if the vehicle speed detected from the rotation of the drive shaft of the vehicle is 0. In such a situation, when the engine is stopped, the driver has a great sense of discomfort. Therefore, a delay process of the stop determination time is performed (step 20).
4). That is, control for automatically stopping the engine based on the vehicle speed 0 is prohibited for a predetermined time. As a result, the time from the vehicle speed 0 to the time when the automatic engine stop control is performed can be set longer than usual, and the time during which the automatic engine stop is performed can be extended earlier.

As described above, the wheel lock is detected by satisfying the condition that the ABS is operated and the brake pressure is large, and the time during which the engine is automatically stopped in that case is extended. Therefore, it is possible to prevent the engine from being automatically stopped while the vehicle is actually moving.

It is another object of the present invention to automatically stop the engine after the vehicle has been stopped reliably, and it is also preferable to change the time during which the engine is automatically stopped according to the wheel lock state. For example, the state of the wheel lock may be estimated in accordance with the operation state of the ABS, and the time until the automatic engine stop control is performed may be controlled in accordance with the state of the vehicle lock. That is, it is preferable that the greater the degree of wheel lock (the greater the slip), the longer the time until the start of control.

The above-described wheel lock is likely to occur on a low μ road having a low coefficient of road surface friction. Therefore,
As shown in FIG. 4, it is determined whether or not the vehicle is on a low μ road (S30).
0) If the road is a low μ road, the time until the start of the automatic engine stop control is extended (S302). This low μ road may be detected from road data of the navigation system, or may be detected from weather conditions such as rain and snow. Further, information on the low μ road may be obtained through communication with the outside.

As described above, on the low μ road, the engine automatic stop control is performed after a lapse of a predetermined time after the vehicle speed becomes zero due to the stop of the drive shaft. Therefore, it is possible to prevent the engine from stopping even when the wheel lock occurs on the low μ road and the vehicle is not actually stopped.

It is also preferable to include a vehicle collision detecting means, and when the vehicle collision detecting means detects a vehicle collision, it is preferable to prohibit the automatic start control of the internal combustion engine by the automatic stop / start control means.

For example, in the automobile 20 shown in FIG. 1, an airbag sensor for detecting a large deceleration of the vehicle generated at the time of a collision, and a gas generator is operated according to a detection signal from the airbag sensor to activate the airbag. An inflation airbag system is provided.

When an airbag activation signal is output from the airbag sensor, the automatic engine start process is prohibited. That is, by the above-described engine automatic stop / start processing, the engine is started under predetermined conditions while the engine is stopped. Therefore, it is determined whether or not the engine is being stopped automatically. If a vehicle collision is detected during the automatic stop of the engine, the automatic start of the engine is prohibited. Thus, it is possible to prohibit the engine from being started in the event of a collision.

The collision may be detected not by a signal from the airbag sensor but by another sensor.
Generally, a collision can be detected by detecting a large acceleration. In other engine automatic start control such as control for automatic engine start during engine stall, it is preferable to prohibit automatic engine start control in the event of a collision.

The embodiments of the present invention have been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various embodiments may be made without departing from the gist of the present invention. Of course, it can be carried out.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an outline of a configuration of an automobile 20 according to an embodiment of the present invention, centering on a vehicle control electronic control unit 30. FIG.

FIG. 2 is a vehicle control ECU 30 of the automobile 20 according to the embodiment;
5 is a flowchart showing an example of an automatic stop / start control routine executed by the CPU.

FIG. 3 is a flowchart illustrating a control routine according to another embodiment.

FIG. 4 is a flowchart showing a control routine in still another configuration example.

[Explanation of symbols]

20 automobile, 30 vehicle control ECU, 32 CP
U, 34 ROM, 36 RAM, 42 shift lever,
44 engine ECU, 46 engine, 48 transmission, 50 clutch, 52 belt, 54 generator motor, 56 inverter, 58 high-voltage battery, 5
9 Current sensor, 60 DC-DC converter, 62
Low voltage battery, 64 relays, 66 starter motor,
68 steering, 70 brake booster, 72 brake master cylinder, 74 ABS / TRC actuator, 76 chassis ECU, 78 meter display section.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G092 AC03 CA01 EA16 FA30 GA01 GA10 GB01 GB02 GB08 HE01Z HF12Z HF18Z HF21Z HF25Z HF28Z 3G093 BA21 BA22 CB02 CB05 DA01 DB05 DB11 DB15 EA01 FA03 FB04

Claims (9)

[Claims] 1. A slip control means for performing a slip control of a wheel and / or a brake assist control means for performing a brake assist control, an automatic stop control for automatically stopping an operation of an internal combustion engine when a predetermined stop condition is satisfied, and a predetermined An automatic stop / start control means for performing an automatic start control for starting the internal combustion engine when a start condition is satisfied, wherein the predetermined stop is performed when the slip control and / or the brake assist control is activated. An automobile having an automatic stop control prohibiting unit that prohibits the automatic stop control by the automatic stop and start control unit until a predetermined release condition is satisfied, regardless of whether the condition is satisfied. 2. The automatic stop control prohibiting means for prohibiting the automatic stop control when the traction control as the slip control is actuated and the running at a predetermined speed or higher for a predetermined time is the predetermined release condition. The vehicle according to claim 1, wherein 3. The automatic stop control prohibiting means, when the antilock brake system as the slip control is activated, changes a shift position to a non-travel position, travels at a predetermined vehicle speed, and releases a brake pedal. 3. The vehicle according to claim 1, wherein at least one of the conditions is the predetermined canceling condition and the automatic stop control is prohibited. 4. The automatic stop control prohibiting means, when the brake assist control is activated, performs at least one of changing a shift position to a non-traveling position, traveling at a predetermined vehicle speed, and releasing a brake pedal. The vehicle according to any one of claims 1 to 3, wherein the predetermined stop condition is a means for prohibiting the automatic stop control. 5. An automobile that performs automatic stop control for automatically stopping operation of an internal combustion engine when a predetermined stop condition is satisfied, and automatic start control for starting the internal combustion engine when a predetermined start condition is satisfied. A vehicle that prohibits the automatic stop control until a predetermined release condition is satisfied when a wheel lock state is detected. 6. An automobile which performs automatic stop control for automatically stopping operation of an internal combustion engine when a predetermined stop condition is satisfied, and automatic start control for starting the internal combustion engine when a predetermined start condition is satisfied. A vehicle that prohibits the automatic stop control when traveling on a low μ road with a low coefficient of friction until a predetermined release condition is satisfied. 7. The vehicle according to claim 6, further comprising vehicle speed detection means for detecting a vehicle speed based on a rotation of a drive shaft of the vehicle, wherein the release of a predetermined time after the vehicle speed becomes zero is canceled. The car to be the condition. 8. The vehicle according to claim 7, wherein the predetermined time is variable according to a moving state of the vehicle. 9. The vehicle according to claim 8, wherein the predetermined time is set according to a wheel lock state or a road surface μ state.