JP2001050076A - Automatic control system for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control an engine more appropriately such as automatic stopping by considering driving environments in addition to controllability of driver and state of vehicle. SOLUTION: Conditions required for stopping an engine are met (S610) when all of the following factors for stopping based on driving environments are fulfilled; when atmospheric pressure is higher than a predetermined value (S520=NO); it is judged that a vehicle does not have to stop temporarily based on image data showing surrounding environments thereof (S550=NO); road congestion level is lower than a predetermined level (S560=NO); road gradient is smaller than a predetermined value (S580=NO); and the current place meets predetermined geographical conditions that allow the engine stop (S600=YES). Then control for stopping the engine is performed. If at least any of those factors is not fulfilled, conditions required for stopping the engine are not satisfied (S530), and thus the engine is not stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic engine control device that can automatically stop an engine when a vehicle stops.

[0002]

2. Description of the Related Art Conventionally, when an automobile stops at an intersection or the like while driving in an urban area, the engine is automatically stopped under a predetermined stop condition, and then the engine is restarted under a predetermined start condition. Automatic stop and start devices are known which save or improve exhaust emissions.

[0003] In such a device, the engine is automatically stopped and automatically started based on a signal reflecting the operation state of a driver such as an accelerator, a brake, a clutch, and a turn signal. Further, the engine is automatically stopped and automatically started based on a signal reflecting a vehicle state such as a degree of charge of a battery and a temperature of engine cooling water.

[0004]

However, in the above-described prior art, since only the operation state of the driver or the vehicle state is considered, the following state cannot be dealt with. For example, if the engine is stopped while traveling at a high altitude, it may be difficult to restart the engine because of a low atmospheric pressure. Therefore, it is preferable not to stop the engine in such a situation. Also, if the engine is stopped while the vehicle is traveling on a road with a steep slope, the vehicle may drop when the engine is restarted. It is preferable not to let them.

[0005] In general, the automatic stop and automatic start of the engine are performed in a situation where the engine is stopped only during a red light at an intersection, for example, but in this case, several seconds to several tens of seconds. Such a period is assumed. However, when the vehicle is stopped at a place where the stop is required, it is almost always necessary to resume the traveling immediately. Therefore, if the engine is stopped in such a situation, the driver's intention will not be met.

Furthermore, in an environment where noise is to be suppressed as much as possible, such as in a residential area, it may be better not to stop the vehicle automatically to avoid noise associated with restart. Also,
Conversely, in an environment such as a mountainous area where it is desired to minimize the adverse effects on the surroundings due to exhaust emissions, it may be better to automatically stop as much as possible.

Accordingly, the present invention provides a control device capable of more appropriately performing control such as automatic stop of an engine by taking into account the driving environment as a viewpoint other than the operation state of the driver or the vehicle state. Aim.

[0008]

Means for Solving the Problems and Effects of the Invention In order to achieve the above object, an invention according to claim 1 is an automatic engine control device for automatically stopping an engine when a predetermined stop condition is satisfied. There is a road condition where the car is running,
The vehicle further includes a traveling environment detection unit that detects a traveling environment including at least one of a surrounding weather condition and a surrounding geographical environment. Then, it is determined whether or not the predetermined stop condition is satisfied, taking into account the traveling environment detected by the traveling environment detecting means.

The technical idea is characterized in that a predetermined stopping condition is determined in consideration of a "driving environment". In order to more clearly understand the meaning, some specific examples of the driving environment are given. It will be described.

(1) For example, in the case of the automatic control device for an engine described in claim 2, an atmospheric pressure is detected as a traveling environment, and when the detected atmospheric pressure is lower than a predetermined value, a predetermined value is detected. It is determined that the stop condition is not satisfied.

This is because when the atmospheric pressure is lower than a predetermined value,
Since it may be difficult to restart after stopping, it is determined that the "stop condition" is not satisfied even if other conditions are satisfied. That is, in the related art, the engine is automatically stopped when a stop condition based on the operation state of the driver or the vehicle state is satisfied. However, if the engine is automatically stopped in a situation where the atmospheric pressure is low, it may be difficult to restart the engine. . Therefore, in such a situation, the stop condition is not satisfied.

Further, for example, when an altitude is detected as a traveling environment as described in claim 3, and the detected altitude is equal to or higher than a predetermined value, it is determined that the predetermined stop condition is not satisfied. Good. If the altitude is equal to or higher than the predetermined value, it is highly possible that the atmospheric pressure becomes equal to or lower than the predetermined value. Therefore, even if other conditions are satisfied, it is determined that the “stop condition” is not satisfied. That is, in the case of claim 2, the atmospheric pressure is directly detected, but in the case of claim 3, the level of the atmospheric pressure is indirectly determined.

In detecting the altitude in this way, it is conceivable that the altitude is detected from the three-dimensional position of the vehicle calculated based on the signal received from the GPS satellite. . When a vehicle equipped with a so-called car navigation device is equipped with an automatic control device of the present engine, the function of the car navigation device may be used, and there is no need to separately provide a GPS receiver.

(2) In the case of the automatic engine control device according to the fifth aspect, the scenery around the own vehicle is detected as image data as a driving environment, and based on the detected image data, the scene of the own vehicle is detected. If there is a situation that requires a relatively short pause within a predetermined distance on the traveling path, it is determined that the predetermined stop condition is not satisfied.

[0015] This is because in a situation where it is highly probable that the vehicle will proceed after a relatively short pause, it is often the case that stopping the engine automatically does not meet the driver's intention. For this reason, the stop condition is not satisfied. The situation in which the engine of the present invention is to automatically stop the engine may be, for example,
This is based on the assumption that the vehicle will be stopped for a relatively long period of time, such as waiting for a train at a railroad crossing, getting on / off of passengers, loading / unloading luggage, etc. In this case, the engine is not automatically stopped when the vehicle is stopped for a short time so as to meet the driver's intention (improvement of drivability).

As the "conditions requiring a relatively short pause", various situations can be assumed for various reasons, and representative ones will be described in order.

First, there is a situation caused by the existence of a point where a stop is required from the viewpoint of the Road Traffic Law. For example, when a paint on the road indicating a stop on the road or a road sign (a sign standing on the roadside, a hanging sign, etc.) is detected, the driver must stop at that point, Pause. However, if the safety is confirmed, the driver wants to restart the vehicle immediately, so stopping the engine in such a situation does not meet the driver's intention. Therefore, the engine is not stopped in a situation caused by a road sign or the like that requires a temporary stop.

A railroad crossing is also a point where a temporary stop is required from the viewpoint of the Road Traffic Law. However, in this case, the situation differs depending on whether the vehicle is temporarily stopped for safety confirmation or stopped waiting for the train to pass. In other words, when a situation in which the circuit breaker is lowered is detected from the image data, it is necessary to stop the engine for a relatively long time as described above. In this case, the engine may be stopped. . However, when the circuit breaker has not been dismounted, the vehicle normally pauses for a few seconds before the railroad crossing and then immediately proceeds again. Conversely, if the engine is stopped in such a situation, the time required for one vehicle to cross the railroad crossing becomes longer,
It can cause traffic jams. Therefore, the engine is not stopped when the vehicle is temporarily stopped due to crossing a railroad crossing that is not waiting for a train.

Further, as described above, from the viewpoint of the Road Traffic Law, not only the point where the temporary stop is always required, but also the stop is required depending on the situation, or such a stop is required. There are also places where good behavior is desired. For example, there may be a situation where a pedestrian or the like is crossing the front of the road on which the own vehicle is traveling, or a case where a road is yielded to a vehicle waiting for a right turn in the opposite lane. These are favorable from the viewpoint of ensuring safety through obligations under the Road Traffic Law and the spirit of mutual consent. However, in this case,
When the pedestrian or the right-turning vehicle disappears, the vehicle restarts immediately, so the engine is not stopped.

Although the above description has been made with reference to the specific situations (1) to (4), various other situations may be envisaged for other reasons.

(3) In the case of the automatic engine control device according to the present invention, a scene around the own vehicle is detected as image data as a driving environment, and based on the detected image data, the scene of the own vehicle is detected. The degree of congestion on the traveling route is determined, and if the degree of congestion is equal to or higher than a predetermined level, it is determined that the predetermined stop condition is not satisfied.

In the case of traffic congestion, the vehicle is frequently stopped and started intermittently. Therefore, if the engine is stopped every time the vehicle is stopped in such a situation, the operation of restarting the vehicle may be performed by the driver. It is troublesome for. Further, even when the driver wants to make the vehicle proceed, the vehicle cannot proceed without first starting the engine, so that a time lag occurs as compared with the case where the engine is not stopped. This may cause an increase in traffic congestion. Therefore, in the case of traffic congestion, it is considered that not stopping the engine is more in line with the driver's intention. It should be noted that depending on the degree of traffic congestion, there are naturally situations where the vehicle cannot be easily advanced. However, in such a case, the driver can operate the ignition key to stop the engine by his / her own will. In other words, when automatically stopping the engine by this automatic control device, in the case of traffic congestion,
The engine was controlled more appropriately.

The "congestion" in the above description means a case where the congestion degree is equal to or higher than a predetermined level. As a method of determining the congestion degree, the method described in claim 7 can be considered. That is, the determination is made based on at least one of the number of vehicles ahead of the traveling road of the own vehicle calculated based on the image data, the ratio of the road surface hidden ahead of the traveling road of the own vehicle, and the inter-vehicle distance to the preceding vehicle. It is. If the number of vehicles in front of the traveling path of the own vehicle is large, it is considered that the degree of congestion is high. Further, if the proportion of the road surface hidden in front of the traveling road of the own vehicle is large, it is considered that this indirectly indicates that the number of vehicles in front of the traveling road of the own vehicle is large. Furthermore, if the inter-vehicle distance from the preceding vehicle is short, it is considered that this also indirectly indicates that the number of vehicles in front of the traveling path of the own vehicle is large. That is, it is considered that the inter-vehicle distance when the degree of congestion is high and the so-called "no-no-ro operation" is extremely shorter than the inter-vehicle distance normally assumed when traveling near the legal speed. Therefore, it is possible to indirectly grasp the degree of congestion based on the inter-vehicle distance from the preceding vehicle.

In addition to the above, a determination method based on lane marks (compartment lines) drawn in white or yellow on a road, for example, can be considered. The more vehicles there are in front of the vehicle, the more difficult they are to recognize the lane mark because they are blocked by those vehicles. Therefore, the degree of congestion may be determined based on the degree of detection of the lane mark.

(4) In the case of the automatic engine control device according to the present invention, a road surface inclination angle is detected as a traveling environment, and if the detected road surface inclination angle is a predetermined value or more, It is determined that the predetermined stop condition is not satisfied.

This is because if the road surface on which the vehicle is traveling has a large road surface inclination angle, the vehicle may go down at the time of restarting, whether it is going up or down. The "stop condition" is determined not to be satisfied.

As means for detecting the inclination angle, for example, the following three methods can be considered.

Method using a tilt sensor: This uses a tilt sensor for directly detecting a road surface tilt angle. As a detection method of the tilt sensor, for example, a method using a pendulum having a pendulum that always faces in a vertical direction may be used.

A method using a brake stroke sensor or a brake pressure sensor: On a flat road, in a three-dimensional orthogonal coordinate system fixed to the vehicle, gravity acting in the vertical direction acts only in the vertical direction of the vehicle, and in the longitudinal direction of the vehicle. Does not work.
On the other hand, on a sloped road, gravity has a component that acts in the longitudinal direction of the vehicle along the slope. The magnitude of the inclination direction component increases as the inclination angle increases. When the vehicle stops on a sloped road, the driver applies a foot brake to prevent the vehicle from traveling along the slope due to the longitudinal component of the force due to gravity. The greater the angle of inclination, the greater the driver generates a greater braking force with a greater amount of depression. Therefore, the inclination angle can be indirectly detected by using the brake stroke sensor or the brake pressure sensor that detects the driver's brake depression amount when the vehicle stops.

Method using acceleration sensor: On a flat road, in a rectangular coordinate system fixed to the vehicle, the gravitational acceleration g pointing in the vertical direction is downward of the vehicle. Therefore, if the detection axis of the acceleration sensor is oriented in the vertical direction, the acceleration sensor detects the gravitational acceleration g itself on a flat road, and when the vehicle stops on a sloped road, g is determined according to the inclination angle θ.
× cos θ will be detected. Since −π ≦ θ ≦ π, even when the inclination angle θ increases in either the positive or negative direction, g × c increases as the absolute value of θ increases.
The absolute value of osθ decreases. Therefore, the acceleration in the up-down direction of the vehicle when the vehicle stops is detected by the acceleration sensor, and it can be detected that the smaller the detected value is, the larger the absolute value of the inclination angle is.

It should be noted that any means other than the above three methods may be used as long as the inclination angle of the road surface can be detected.

(5) In the case of the automatic engine control device according to the ninth aspect, the driving environment detecting means has a current position detecting means and a map information storing means, and the driving environment detecting means detects the current position. Whether the position of the own vehicle is in a predetermined geographical environment where the engine stop is inappropriate is detected based on the map information stored in the map information storage means. Then, when the own vehicle position exists in a predetermined geographical environment, it is determined that the predetermined stop condition is not satisfied.

In the above-mentioned claim, it is preferable that, based on image data around the own vehicle, if there is a situation in which a relatively short pause is required within a predetermined distance on the traveling path of the own vehicle, It is determined that the predetermined stop condition is not satisfied. "
In this case, "in a predetermined geographical environment where the engine stop is inappropriate" is estimated from the current position of the own vehicle.

As the "in a predetermined geographical environment where the engine stop is inappropriate", various environments are assumed from the viewpoint of safety or the viewpoint of preventing the driver from feeling uncomfortable.

First, as an environment determined from the viewpoint of safety, an intersection, a railroad crossing, a slope, and the like can be considered. A railroad crossing, a slope, and the like can be detected by another detection method as described above, but are detected from the current location information here. This is mainly due to the fact that when the engine is automatically stopped in such a situation, the restart is not successful, and the risk is large.

When the danger of a rear-end vehicle colliding with the own vehicle is taken into consideration, the environment determined from the viewpoint of safety includes an environment in the middle of a curved road or near the top of a sloping road that turns from an uphill to a downhill. Are also mentioned.

On the other hand, the environment determined from the viewpoint of preventing the driver from feeling uncomfortable is assumed to be in a parking lot, near an intersection, and the like. For example, in a parking lot, in order to park in a predetermined parking space, the driver often switches back and forth. If the engine is stopped every time the vehicle stops for a short time, the driver feels very uncomfortable. Remember, the time it takes to actually complete the parking will be longer. In the vicinity of the intersection, as described in claim 5, the situation where a pedestrian or the like is crossing the front of the road on which the own vehicle runs, or the case where the vehicle yields to a right-turning vehicle in the oncoming lane, etc. For this reason, even if such a situation is not actually detected, the engine is not stopped in a geographical environment in which such a possibility is high.

(6) In the case of the automatic engine control apparatus according to the tenth aspect, the traveling environment detecting means has a current position detecting means and a map information storing means, and the driving environment detecting means detects the current position. It is detected based on the map information stored in the map information storage means whether or not the vehicle position is within a predetermined geographical environment in which the influence on the surroundings by at least one of noise and exhaust is to be considered. Then, when the vehicle location is within a predetermined geographical environment, it is determined whether or not a predetermined stop condition is satisfied in consideration of the geographical environment.

For example, when the predetermined geographical environment places importance on the influence of noise on the surroundings, it is determined that the predetermined stop condition is not satisfied. I do. This takes into consideration that in an environment such as a residential area where noise is to be minimized as much as possible, it is better not to stop automatically in order to avoid noise due to restart.

On the contrary, when the predetermined geographical environment is such that the influence on the surroundings by the exhaust gas should be relatively emphasized, conditions other than the geographical environment may be used. May be determined to satisfy the predetermined stop condition. This is because in an environment such as a mountain area where it is desired to minimize the adverse effects on the surroundings due to exhaust emission, it is considered that it is better to automatically stop as much as possible. In addition, when taking into account such a predetermined geographical environment, the viewpoint of responding to, for example, administrative or social demands, rather than the viewpoint of "according to the driver's intention" is considered. It is. Therefore, it is not always preferable to stop the vehicle automatically because it is a residential area, but it is also conceivable that there are areas where it is desired to minimize the influence of the surroundings due to exhaust emission even in a residential area.

The above is a description of a specific example of the "running environment" and how to determine whether or not a predetermined stop condition is satisfied by taking that into account. Therefore, the automatic control device for the engine of the present invention may execute only the control for automatically stopping the engine. That is, the restart after the stop may completely depend on the manual operation by the driver.

However, as in the case of an automatic start / stop device for an engine, the start may be naturally performed by automatic control. In this case, the engine is configured to automatically start the vehicle engine by energizing the starter when a predetermined starting condition is satisfied after the automatic stop of the engine. May be realized as an automatic control device.

It should be noted that, when the engine is automatically stopped and then automatically started, it is questioned whether the running environment considered at the time of stopping should be considered at the time of starting. However, we do not consider this to be a problem. The reason for the automatic stop is that it is determined that the vehicle can be stopped even in consideration of the above-described conditions such as the atmospheric pressure, and the vehicle is not moved during the stop. It is considered that there is no problem even if the engine is started at a time.

[0044]

Embodiments of the present invention will be described below with reference to the drawings. It is needless to say that the embodiments of the present invention are not limited to the following examples, and can take various forms as long as they belong to the technical scope of the present invention.

FIG. 1 is a block diagram showing the electrical configuration of the automatic engine control device 1 of the present embodiment. The automatic control device 1 is an electronic control unit (hereinafter, simply referred to as an ECU) 1 for executing engine idle stop control.
It is configured around 0. Although not shown, the ECU 10 controls a CPU for controlling various devices, a ROM in which various numerical values and programs are written in advance, a RAM in which numerical values and flags in the operation process are written in a predetermined area, and converts an analog input signal into a digital signal. A / D converter, an input / output interface (I / O) from which various digital signals are input and various digital signals are output, a timer, and a bus line to which each of these devices is connected. The processing shown in the flowchart described below is
It is executed based on a control program previously written in the ROM.

As shown in FIG. 1, the ECU 10 detects a crank angle sensor 21 for detecting a crank angle and a pressure of an intake pipe connected to each cylinder of the engine and provided for taking in air. Intake pipe pressure sensor 22
A vehicle speed sensor 23 for detecting a traveling speed of the vehicle, an accelerator opening sensor 24 for detecting an amount of depression of an accelerator pedal, a brake stroke sensor 25 for detecting an amount of depression of a brake pedal, An atmospheric pressure sensor 26 for detecting atmospheric pressure, a CCD camera 27 for capturing a scene in front of the vehicle as an image,
An inclination angle sensor 28 for detecting the inclination angle of the road surface and a navigation unit 29 for executing a navigation function are connected.
Is input to

The ECU 10 performs arithmetic processing according to a predetermined control program based on information from each of the sensors and the like, and outputs a starter drive signal for the starter 31 and a igniter 32 via a drive circuit (not shown). It outputs an ignition cut and ignition signal and a fuel cut and fuel injection signal for the fuel injection valve 33.

In the configuration shown in FIG. 1, the landscape image in front of the vehicle captured by the CCD camera 27 is output to the ECU 10. Therefore, the ECU 10 has a function of processing this image. Become. However, image processing generally has a large processing load. For example, the function of processing a landscape image ahead of the vehicle captured by the CCD camera 27 may be provided outside the ECU 10. That is, an image processing unit is provided between the CCD camera 27 and the ECU 10 and the result of processing by the image processing unit is provided by the ECU 10.
May be input. The information obtained by processing the landscape image in front of the vehicle captured by the CCD camera 27 is the degree of congestion on the traveling path of the vehicle.

The degree of congestion is, for example, at least one of the number of vehicles in front of the traveling road of the own vehicle calculated based on the image data, the proportion of the road surface hidden in front of the traveling road of the own vehicle, and the inter-vehicle distance to the preceding vehicle. It is conceivable to make a determination based on one. If the number of vehicles in front of the traveling path of the own vehicle is large, it is considered that the degree of congestion is high. Further, if the proportion of the road surface hidden in front of the traveling road of the own vehicle is large, it is considered that this indirectly indicates that the number of vehicles in front of the traveling road of the own vehicle is large. Moreover,
If the inter-vehicle distance to the preceding vehicle is short, it is considered that this also indirectly indicates that the number of vehicles in front of the traveling path of the own vehicle is large. That is, it is considered that the inter-vehicle distance when the degree of congestion is high and the so-called "no-no-ro operation" is extremely shorter than the inter-vehicle distance normally assumed when traveling near the legal speed. Therefore, it is possible to indirectly grasp the degree of congestion based on the inter-vehicle distance from the preceding vehicle.

The navigation unit 29 includes a GPS (Gl
A GPS receiver 29a, a map information storage unit 29b, and the like are provided for receiving a transmission radio wave from an artificial satellite for an obal positioning system via a GPS antenna and detecting the position, direction, speed, and the like of the vehicle. In practice,
The navigation unit 29 includes a gyroscope, a vehicle speed sensor, or a geomagnetic sensor for performing position detection, in addition to the GPS receiver 29a, an operation switch group for inputting a user's instruction, and various guidance. Although a speaker and a display device for notifying the above are also provided, they are omitted because they are not the main components related to the automatic start and stop of the engine.

The vehicle position detected by the GPS receiver 29a is three-dimensional data including latitude (X), longitude (Y), and altitude (Z), and the navigation unit 29 uses the three-dimensional data based on the altitude. The altitude is calculated and output to the ECU 10. In addition, based on the detected vehicle position and map information, the ECU 10 outputs to the ECU 10 geographical environment information indicating in which geographical environment the vehicle is currently located. The geographical environment information includes information indicating that it is better to stop the engine automatically as much as possible, and information indicating that it is better to stop the engine automatically as much as possible. . These will be described later.

The tilt angle sensor 28 has a pendulum, and directly detects the road surface tilt angle by using the fact that the pendulum always faces the vertical direction. It has an element that detects the relative displacement between the pendulum and the pendulum.In a flat place, the pendulum is located at the center of the detecting element, but when placed on an inclined place, the relative position between the pendulum and the detecting element is changed. It changes with respect to a flat state. The tilt angle sensor optically and magnetically detects the change in the relative position.

Next, the process for the automatic stop and automatic start of the engine, which is executed by the ECU 10 of the automatic engine control device 1 configured as described above, will be described with reference to the flowcharts of FIGS.

At step 10 in FIG. 2 (hereinafter, step is abbreviated as S), the brake stroke is detected based on the output signal of the brake stroke sensor 25. At S20, the output signal from the vehicle speed sensor 23 is detected. The vehicle speed is detected based on the vehicle speed. Then, in S30, it is determined whether or not the vehicle speed is 0. If the vehicle speed is 0 (S30: YES),
The process proceeds to S40 for the next check, and if the vehicle speed is not 0 (S30: NO), the process returns to S10. That is,
Since the condition for automatic stop of the engine is not satisfied just because the vehicle speed is not 0, the engine is continuously operated.

On the other hand, in S40, it is determined whether or not the brake stroke is larger than 15%. If the brake stroke is larger than 15% (S30: YE
S), the process proceeds to S50 for the next check, while if the brake stroke is 15% or less (S30: N
O), and return to S10. That is, the brake stroke is 1
The condition of automatic stop of the engine is not satisfied only by the fact that it is 5% or less, so that the engine is continuously operated.

On the other hand, in S50, a stop condition is determined based on the traveling environment. Although the details of the stop condition determination will be described later, a result indicating whether the stop condition is satisfied or not satisfied is obtained by this determination. Therefore, in S60, it is determined whether or not the stop condition is satisfied. If the stop condition is not satisfied (S60: NO), the process returns to S10. That is, even if the stop condition based on the vehicle speed and the brake stroke is satisfied (S30: YES, S40: YES),
If the stop condition based on the traveling environment determined in S50 is not satisfied (S60: NO), the engine automatically continues to run because the condition for automatically stopping the engine is not finally satisfied.

On the other hand, if the stop condition based on the traveling environment is satisfied (S60: YES), the flow shifts to S70 to stop the injection control. That is, the engine is automatically stopped by the fuel cut signal or the ignition cut signal. When the engine is stopped in this way, it is determined whether or not the brake stroke is less than 5% (S80). And the brake stroke is 5%
In the above case (S80: NO), the process returns to S70 to continue the engine stop state.

On the other hand, if the brake stroke is less than 5% (S80: YES), it is presumed that the driver's operation is to restart the vehicle.
The process proceeds to 90 to perform a process for restarting the engine. That is, in S90, a starter drive signal is output to perform cranking (S90), and in S100, a fuel injection signal and an ignition signal are output to perform fuel injection and ignition control.

Then, the engine speed is detected (S11).
0), it is determined whether or not the engine speed has exceeded 600 rpm (S120). Engine speed is 600r
pm (S120: NO) until S90-S1
If the engine speed exceeds 600 rpm (S120: YES), the process proceeds to S130 to stop cranking. As a result, the engine is driven and the vehicle is ready to restart.

Next, the details of the determination of the stop condition based on the traveling environment in S50 will be described with reference to FIG.

In the first step of FIG. 3, the atmospheric pressure is detected based on the output signal from the atmospheric pressure sensor 26 (S5).
10). Then, it is determined whether or not the detected atmospheric pressure is equal to or lower than a predetermined value (S520). If the atmospheric pressure is equal to or lower than the predetermined value (S520: YES), the process immediately proceeds to S530, and the stop condition is not satisfied. This processing routine is terminated and
Return to 60.

This is because when the atmospheric pressure is lower than a predetermined value,
In some cases, it is difficult to restart after stopping, so that the "stop condition" is not satisfied even if other conditions are satisfied. That is, in the related art, the engine is automatically stopped when a stop condition based on the operation state of the driver or the vehicle state is satisfied. However, if the engine is automatically stopped in a situation where the atmospheric pressure is low, it may be difficult to restart the engine. . Therefore, in such a situation, the stop condition is not satisfied.

On the other hand, if the atmospheric pressure is larger than the predetermined value (S520: NO), the condition relating to the atmospheric pressure is satisfied, and the flow shifts to S540 for the next condition determination. S5
At 40, the surrounding environment of the vehicle is detected as image data based on the front image of the vehicle captured by the CCD camera 27. Then, based on the image data, it is determined whether or not the situation requires the vehicle to be temporarily stopped. If such a situation is present (S550: YES), the process immediately proceeds to S530 and the stop condition is not satisfied. Then, the processing routine ends, and the process returns to S60 of FIG.

This is because in a situation where it is highly probable that the vehicle will proceed after a relatively short pause, it is often the case that stopping the engine automatically does not meet the driver's intention. For this reason, the stop condition is not satisfied. The intention to automatically stop the engine is, for example, waiting for a signal, waiting for a train
Contrary to this, it is assumed that the vehicle will be stopped for a relatively long period of time, such as when passengers get on and off or load or unload luggage. In this state, the engine is not automatically stopped in order to meet the driver's intention (improvement of drivability).

Various situations are conceivable as the "situation requiring a relatively short pause" for various reasons. For example, paint on the road to indicate a temporary stop on the road, road signs (e.g., standing on the roadside, hanging signs, etc.)
Is detected, the driver has to stop at that point, so the driver temporarily stops the vehicle. However, if the safety is confirmed, the driver wants to restart the vehicle immediately, so stopping the engine in such a situation does not meet the driver's intention. Therefore, the engine is not stopped in a situation caused by a road sign or the like that requires a temporary stop. They are,
It can be said that this situation is caused by the existence of a point where a stop is required from the viewpoint of the Road Traffic Law.

A railroad crossing is also a point where a temporary stop is required from the viewpoint of the Road Traffic Law. However, in this case, the situation differs depending on whether the vehicle is temporarily stopped for safety confirmation or stopped waiting for the train to pass. In other words, when a situation in which the circuit breaker is lowered is detected from the image data, it is necessary to stop the engine for a relatively long time as described above. In this case, the engine may be stopped. . However, when the circuit breaker has not been dismounted, the vehicle normally pauses for a few seconds before the railroad crossing and then immediately proceeds again. Conversely, if the engine is stopped in such a situation, the time required for one vehicle to cross the railroad crossing becomes longer, which may cause traffic congestion. Therefore, the engine is not stopped when the vehicle is temporarily stopped due to crossing a railroad crossing that is not waiting for a train.

In addition, as described above, not only the point where the temporary stop is always required from the viewpoint of the road traffic law, but also the stop is required depending on the situation, or such a behavior may occur. There are also points that are desired. For example, there may be a situation where a pedestrian or the like is crossing the front of the road on which the own vehicle is traveling, or a case where a road is yielded to a vehicle waiting for a right turn in the opposite lane. These are favorable from the viewpoint of ensuring safety through obligations under the Road Traffic Law and the spirit of mutual consent. However, even in this case, if the pedestrian or the right-turning vehicle no longer exists, the vehicle will re-start immediately,
The engine was not stopped. Of course, for other reasons, "a situation where a relatively short pause is required" can be assumed in various ways.

On the other hand, if the situation does not require a temporary stop (S550: NO), the flow shifts to S560 for the next condition determination. In S560, it is determined whether or not the congestion degree is equal to or higher than a predetermined level based on the front image of the vehicle obtained in S540. If the congestion degree is equal to or higher than the predetermined level (S560: YES), the process immediately proceeds to S530,
It is determined that the stop condition is not satisfied, the processing routine ends, and the process returns to S60 of FIG.

This is because, in the case of traffic congestion, the vehicle is frequently stopped and started intermittently. Therefore, if the engine is stopped every time the vehicle is stopped in such a situation, the operation of restarting the vehicle may be performed by the driver. It is troublesome for. Further, even when the driver wants to make the vehicle proceed, the vehicle cannot proceed without first starting the engine, so that a time lag occurs as compared with the case where the engine is not stopped. This may cause an increase in traffic congestion. Therefore, in the case of traffic congestion, it is considered that not stopping the engine is more in line with the driver's intention. It should be noted that depending on the degree of traffic congestion, there are naturally situations where the vehicle cannot be easily advanced. However, in such a case, the driver can operate the ignition key to stop the engine by his / her own will. In other words, when the automatic control device 1 automatically stops the engine, the engine is not stopped in the case of traffic congestion, so that more appropriate control is performed.

When determining whether or not the congestion degree is equal to or higher than a predetermined level based on the image data, for example, the number of vehicles in front of the traveling road of the own vehicle and the road surface in front of the traveling road of the own vehicle are hidden. The determination can be made based on at least one of the ratio and the inter-vehicle distance to the preceding vehicle. If the number of vehicles in front of the traveling path of the own vehicle is large, it is considered that the degree of congestion is high. Further, if the proportion of the road surface hidden in front of the traveling road of the own vehicle is large, it is considered that this indirectly indicates that the number of vehicles in front of the traveling road of the own vehicle is large. Furthermore, if the inter-vehicle distance from the preceding vehicle is short, it is considered that this also indirectly indicates that the number of vehicles in front of the traveling path of the own vehicle is large.
That is, it is considered that the inter-vehicle distance when the degree of congestion is high and the so-called "no-no-ro operation" is extremely shorter than the inter-vehicle distance normally assumed when traveling near the legal speed. Therefore, it is possible to indirectly grasp the degree of congestion based on the inter-vehicle distance from the preceding vehicle.

It is to be noted that, besides this, for example, a determination method based on lane marks (compartment lines) drawn in white or yellow on a road can be considered. The more vehicles there are in front of the vehicle, the more difficult they are to recognize the lane mark because they are blocked by those vehicles. Therefore, the degree of congestion may be determined based on the degree of detection of the lane mark.

On the other hand, if the congestion degree is less than the predetermined level (S560: NO), the flow shifts to S570 to determine the next condition. In S570, the road surface inclination angle is detected based on the output signal from the inclination angle sensor 28, and in subsequent S580, it is determined whether or not the inclination angle is equal to or more than a predetermined value. If the inclination angle is equal to or larger than the predetermined value (S580: YES), the process immediately proceeds to S.
The flow shifts to 530, where the stop condition is not satisfied, the present processing routine ends, and the flow returns to S60 in FIG.

This is because if the road surface on which the vehicle is traveling has a large road surface inclination angle, the vehicle may go down at restart even if it is going up or down. The stop condition is not satisfied, and the engine is not stopped.

On the other hand, when the inclination angle is smaller than the predetermined value (S5)
80: NO), and proceeds to S590 for the next condition determination. In S590, the current location is detected based on the output signal from the navigation unit 29, and in S600, it is determined whether the current location is in a predetermined geographical environment where the engine can be stopped. In making this determination, the navigation unit 29
Refer to the geographical environment information output from. If the engine is stopped in a predetermined geographical environment (S
600: YES), since all the conditions so far are satisfied, the flow shifts to S610 to satisfy the stop condition, ends this processing routine, and returns to S60 in FIG. In this case, since a positive determination is made in S60, S
The routine proceeds to 70, where control for stopping the engine is performed.

On the other hand, if it is not a predetermined geographical environment in which the engine can be stopped (S600: NO), the flow shifts to S530 to determine that the stop condition is not satisfied, ends this processing routine, and returns to S60 in FIG. Return.

By the way, the determination of “whether or not the engine is in a predetermined geographical environment where the engine can be stopped” is actually determined as “the predetermined geographical environment where the engine stop is inappropriate”.
It is determined whether it is other than or not. Therefore, "predetermined geographic environment where engine shutdown is inappropriate"
The following describes what environment is set. Conceptually, various environments are assumed from the viewpoint of safety or prevention of discomfort to the driver.First, as the environment determined from the viewpoint of safety, there are intersections, railroad crossings, slopes, etc. Conceivable. A railroad crossing, a slope, and the like can be detected by another detection method as described above, but are detected from the current location information here. This is mainly due to the fact that when the engine is automatically stopped in such a situation, the restart is not successful, and the risk is large.

When the risk of a rear-end vehicle colliding with the own vehicle is taken into consideration, the environment determined from the viewpoint of safety includes an environment in the middle of a curved road or near the top of a hill that turns from an uphill to a downhill. Are also mentioned.

On the other hand, the environment determined from the viewpoint of preventing the driver from feeling uncomfortable may be in a parking lot, near an intersection, or the like. For example, in a parking lot, in order to park in a predetermined parking space, the driver often switches back and forth. If the engine is stopped every time the vehicle stops for a short time, the driver feels very uncomfortable. Remember, the time it takes to actually complete the parking will be longer. In the vicinity of the intersection, as described in claim 5, the situation where a pedestrian or the like is crossing the front of the road on which the own vehicle runs, or the case where the vehicle yields to a right-turning vehicle in the oncoming lane, etc. For this reason, even if such a situation is not actually detected, the engine is not stopped in a geographical environment in which such a possibility is high.

Further, it is possible to set an environment in which the influence on the surroundings due to noise should be relatively emphasized. For example, in an environment such as a residential area where it is desired to suppress noise as much as possible, it is considered that it is better not to stop the vehicle automatically to avoid noise due to restart.
On the contrary, it is also possible to set an environment in which the influence of the exhaust air on the surroundings should be relatively emphasized. For example, in an environment such as a mountain area where it is desired to minimize the adverse effect on the surroundings due to exhaust emission, it is considered that it is better to automatically stop as much as possible. In addition,
When such a predetermined geographical environment is taken into consideration, it is based on the viewpoint of, for example, responding to administrative or social demands, rather than the point of "being in line with the driver's intention". . Therefore, it is not always preferable to stop the vehicle automatically because it is a residential area, but it is also conceivable that there are areas where it is desired to minimize the influence of the surroundings due to exhaust emission even in a residential area.

In this embodiment, the atmospheric pressure sensor 2
6. The CCD camera 27, the tilt angle sensor 28, the navigation unit 29, and the ECU 10 that performs processing for detecting various driving environments based on signals from these sensors and the like correspond to driving environment detection means. The GPS in the navigation unit 29
The receiver 29a corresponds to a current position detecting unit, and the map information storage unit 29b corresponds to a map information storage unit.

As described above, according to the automatic engine control apparatus 1 of the present embodiment, by taking into account the driving environment as a viewpoint other than the operation state of the driver or the vehicle state, it is possible to more appropriately control the automatic stop of the engine and the like. It can be performed.

For example, if the engine is automatically stopped in a situation where the atmospheric pressure is low, it may be difficult to restart the engine. In such a situation, it is possible to prevent inconvenience by not satisfying the stop condition. Also, in a situation where it is highly likely that the vehicle will start progressing after a relatively short pause, such as when stopping at a pause line, etc., the driver may stop the engine automatically. Since the intention is not met, the engine can be prevented from being stopped. Further, when the road surface inclination angle is large, the vehicle may go down at the time of restart, so that the engine can be prevented from being stopped. Moreover,
In a "predetermined geographical environment where the engine stop is inappropriate" assumed from a viewpoint of safety or a viewpoint of preventing a driver from feeling uncomfortable, the engine can be prevented from being stopped.

[Other Embodiments] (1) In the above embodiment, as shown in FIG. 2, after the engine is automatically stopped (S70), if a predetermined starting condition is satisfied (S80: YES). The engine is automatically started (S90 to S130). Therefore, the automatic stop / start control of the engine is performed, but control that only stops the engine automatically may be performed. That is, the restart after the stop may completely depend on the manual operation by the driver.

(2) In the above embodiment, the atmospheric pressure sensor 26
Is used to directly detect the atmospheric pressure.For example, when the altitude is detected and the detected altitude is equal to or more than a predetermined value, the predetermined stop condition may be determined to be not satisfied. . If the altitude is equal to or higher than the predetermined value, it is highly possible that the atmospheric pressure becomes equal to or lower than the predetermined value. Therefore, even if other conditions are satisfied, it is determined that the “stop condition” is not satisfied. That is, when the atmospheric pressure sensor 26 is used, the atmospheric pressure is directly detected. When the altitude is used, the level of the atmospheric pressure is indirectly determined. Detection of the altitude can be easily realized by obtaining altitude information from the navigation unit 29. In this case, the atmospheric pressure sensor 26 becomes unnecessary.

(3) In the above embodiment, the inclination angle sensor 28 is used to detect the road surface inclination angle. However, the inclination angle may be detected based on the brake stroke detected by the brake stroke sensor 25, for example. That is, when the vehicle stops on a sloped road, the driver applies a foot brake to prevent the vehicle from traveling along the slope due to the longitudinal component of the force due to gravity. The greater the angle of inclination, the greater the driver generates a greater braking force with a greater amount of depression. Therefore, the inclination angle can be indirectly detected by using the brake stroke, which is the amount of depression of the driver's brake when the vehicle stops. Note that a brake pressure sensor may be used from a similar viewpoint.

Further, the inclination angle can be detected by using an acceleration sensor. The acceleration in the vertical direction of the vehicle when the vehicle stops is detected by the acceleration sensor, and it can be detected that the smaller the detected value is below the gravity value, the larger (the absolute value of) the inclination angle is.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of an automatic control device for an engine according to an embodiment.

FIG. 2 is a flowchart illustrating a process related to automatic stop / start of an engine executed by an ECU according to the embodiment.

FIG. 3 is a flowchart illustrating a processing routine related to a stop condition determination based on a traveling environment during processing in FIG. 2;

DESCRIPTION OF SYMBOLS 1 ... Automatic control device for engine 10 ... Engine idle stop ECU 21 ... Crank angle sensor 22 ... Intake pipe pressure sensor 23 ... Vehicle speed sensor 24 ... Accelerator opening sensor 25 ... Brake stroke sensor 26 ... Atmospheric pressure sensor 27 ... CCD camera 28 ... Tilt angle sensor 29 ... Navi unit 29a ... GPS receiver 29b ... Map information storage unit 31 ... Starter 32 ... Igniter 33 ... Fuel injection valve

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Claims (13)

[Claims] An automatic control device for an engine for automatically stopping an engine when a predetermined stop condition is satisfied, comprising: a road condition in which the own vehicle is traveling; a surrounding weather condition; and a surrounding geographical environment. A driving environment detecting means for detecting a driving environment including at least one of the following; and determining whether or not the predetermined stop condition is satisfied in consideration of the driving environment detected by the driving environment detecting means. Automatic control device. 2. The automatic control device for an engine according to claim 1, wherein said traveling environment detecting means detects an atmospheric pressure as said traveling environment, and said detected atmospheric pressure is equal to or lower than a predetermined value. An automatic control device for an engine, wherein it is determined that the predetermined stop condition is not satisfied. 3. The automatic control device for an engine according to claim 1, wherein said traveling environment detecting means detects an altitude as said traveling environment, and when the detected altitude is not less than a predetermined value. An engine automatic control device for determining that the predetermined stop condition is not satisfied. 4. The automatic control device for an engine according to claim 3, wherein the driving environment detecting means detects the elevation from a three-dimensional position of the vehicle calculated based on a signal received from a GPS satellite. A featured automatic engine control device. 5. The automatic control device for an engine according to claim 1, wherein the driving environment detecting means detects, as the driving environment, a scenery around the own vehicle as image data. Based on the above, when there is a situation that requires a relatively short pause within a predetermined distance on the traveling path of the own vehicle, it is determined that the predetermined stop condition is not satisfied. Automatic control device for the engine. 6. The automatic control device for an engine according to claim 1, wherein the driving environment detecting means detects a scene around the own vehicle as the driving environment as image data. An automatic control device for an engine, wherein the degree of congestion on the traveling path of the own vehicle is determined, and when the degree of congestion is equal to or higher than a predetermined level, the predetermined stop condition is determined to be not satisfied. . 7. The automatic control device for an engine according to claim 6, wherein the congestion degree is calculated based on the image data, the number of vehicles in front of the traveling road of the own vehicle, and the hiding of the road surface in front of the traveling road of the own vehicle. An automatic control device for the engine, wherein the determination is made based on at least one of a ratio of the vehicle and an inter-vehicle distance to a preceding vehicle. 8. The automatic control device for an engine according to claim 1, wherein the traveling environment detecting means detects a road surface inclination angle as the traveling environment, and the detected road surface inclination angle is a predetermined value or more. In some cases, it is determined that the predetermined stop condition is not satisfied. 9. An automatic control system for an engine according to claim 1, wherein said driving environment detecting means has a current position detecting means and a map information storing means, and the position of the vehicle detected by said current position detecting means is used to stop the engine. Detecting whether the vehicle is in a predetermined geographical environment that is inappropriate based on the map information stored in the map information storage means, wherein the own vehicle position is within the predetermined geographical environment. If present,
An automatic control device for an engine, wherein it is determined that the predetermined stop condition is not satisfied. 10. The automatic control device for an engine according to claim 1, wherein the driving environment detecting means has a current position detecting means and a map information storing means, and the position of the vehicle detected by the current position detecting is noise or exhaust. Detecting whether or not the vehicle is in a predetermined geographical environment in which the influence on the surroundings due to at least one of the above is to be considered, based on the map information stored in the map information storage means. Is present in the predetermined geographical environment,
An automatic control device for an engine, which determines whether or not the predetermined stop condition is satisfied in consideration of the geographical environment. 11. The automatic control device for an engine according to claim 10, wherein when the predetermined geographical environment is such that the influence of the noise on the surroundings is relatively important, the predetermined stop condition is set. Is an automatic control device for an engine, which determines that the condition is not satisfied. 12. The automatic control device for an engine according to claim 10, wherein when the predetermined geographical environment is such that the influence on the surroundings due to the exhaust gas is relatively important, the predetermined geographical environment is different from the geographical environment. If the condition is satisfied, it is determined that the predetermined stop condition is satisfied. 13. An automatic control device for an engine according to claim 1, wherein after a predetermined start condition is satisfied after the automatic stop of the engine, the starter is energized to automatically start the engine of the vehicle. An automatic engine control device characterized in that the engine is automatically started.