JP4441881B2 - ENGINE STOP CONTROL DEVICE, ENGINE START CONTROL DEVICE, AND METHOD THEREOF - Google Patents

Description

  The present invention relates to an engine stop / start control technique for effectively performing idling stop (engine stop when a vehicle is stopped) for suppressing fuel consumption and exhaust gas of an automobile.

Recently, the development of electric vehicles, etc. is progressing as an environmental measure, but in gasoline vehicles as well, the engine is stopped when the vehicle stops (idling stop) in order to reduce fuel consumption and exhaust gas. It has been studied and evaluated to suppress exhaust gas caused by idling.
Each local government has established ordinances regarding the implementation of idling stops, and a device that automatically stops idling when stopped by a city bus or the like has been put into practical use. The bus is said to be sufficiently effective because the stop time for passengers to get on and off is very large compared to the total travel time, but recently it is also a signal for ordinary cars such as passenger cars. It is recommended that the idling stop be performed while the waiting is stopped.

However, when this method is applied to a general passenger car or the like, a general passenger car or the like does not have a long stop time like a bus, so the fuel consumption when restarting the stopped engine must be considered. .
The relationship between the fuel consumption and the engine stop time is generally expressed in FIG. In the figure, t1 represents a steady idling period, t2 represents an idling stop period, and t3 represents a restart period. S1 represents the fuel saved in the idling stop period, and S2 represents the fuel used for restart. If the engine stop time is short, the fuel consumption S2 due to restart becomes larger than the fuel consumption S1 due to idling, and the meaning of engine stop is lost. Therefore, when applied to a passenger car or the like, it is necessary to predict the stop time of the vehicle as accurately as possible.

Recently, it has been found that the idling stop time of about 5 seconds is a limit time for effectively performing the idling stop (see Non-Patent Document 1). Yes.
Therefore, in Patent Document 2, when the vehicle stops while waiting for a signal, a stop time until the vehicle starts running again is calculated. If the stop time is within a threshold value, the engine is not automatically stopped. A technique for keeping the engine running is shown.
"Consideration of effective stop time of idling stop waiting for traffic light" (Japan Society of Automotive Engineers of Science Lecture Preprints No.4-03, May 21, 2003) JP-A-9-128677 JP 2002-303173 A

  In Patent Document 2, the time until the start of the green signal is adopted as the stop time, but the actual stop time of the vehicle is not determined by this, and it is between the start of the green signal and the start of movement of the traffic flow. It is necessary to consider the time delay. In heavy traffic, there are many situations that move when there is a red light and stop when there is a green light. Therefore, in the conventional technique, an effective idling stop may not be realized.

It is an object of the present invention to provide an engine stop control device and a method thereof capable of accurately predicting a stop time of a vehicle by grasping a behavior of a traffic flow and effectively executing or releasing an idling stop. Objective.

When the vehicle stops at a green light, the engine stop control device of the present invention has a travel monitoring means for determining that the vehicle has stopped, an elapsed time since the start of the green signal at the downstream intersection, and a green signal at the downstream intersection. from but started, the prediction unit from the vehicle based on the start delay time and the distance L Ru is calculated as the time progresses the starting wave to the stop line of the downstream intersection, predicts the stopping time of the vehicle, Determination means for determining whether or not the engine can be stopped by comparing the stop time predicted by the prediction means with a threshold value.

  Thus, by considering not only the green light start time of the nearest intersection but also the start delay time as a function of the distance from the vehicle to the stop line of the intersection, the behavior of the traffic flow can be grasped and the vehicle stop time Therefore, the idling stop can be executed logically and effectively, so that the maximum exhaust gas reduction effect can be exhibited without causing a delay in traffic flow.

The engine stop may be performed automatically without driver operation, or may be performed by driver operation by providing timing information to the driver.
The start delay time can be considered to be proportional to the distance L from the vehicle to the downstream intersection.
In particular, the function is represented by L / v, where v is the velocity of the starting wave after the start of the green signal.

It is preferable that the travel monitoring means determine the stop of the vehicle on condition that the stop of the vehicle continues for a predetermined time. This is to exclude the stop when the vehicle waiting for the signal repeats the go-stop.
The determination means should not determine whether or not the engine can be stopped when the distance L to the stop line at the downstream intersection is longer than a predetermined distance. The “predetermined distance” refers to a distance from a point far from the downstream intersection so that it is unlikely that the signal is waiting for a signal, to the downstream intersection.

The “threshold value” can be set to an appropriate value depending on whether the air conditioner is used, operation time (distance), season, weather, time zone (time), or temperature. This is because the limit time (threshold) for effectively performing idling stop varies depending on whether the air conditioner is used, operation time (distance), season, weather, time zone (time), or temperature. .
In addition, the engine stop control device of the present invention may be configured by a device mounted on a vehicle, or may be configured by a road device.

  When mounted on a vehicle, the engine stop control device provides information on the green signal start time, the distance from the communication point to the stop line at the downstream intersection, and the speed of the starting wave after the start of the green signal from the on-road device installed on the roadside. Based on the means for receiving by road-to-vehicle communication, the means for measuring the travel distance of the vehicle, the distance from the received communication point to the stop line of the downstream intersection, and the measured travel distance, the downstream intersection from the vehicle Means for calculating the distance L to the stop line.

  When configured with a road device, the vehicle receives position information of the vehicle from the in-vehicle device, transmits information on the result of the idling stop from the road device to the in-vehicle device by road-to-vehicle communication, and is equipped with the idling stop function. The engine is stopped or information on engine stop is transmitted to the driver. At this time, the vehicle restart timing or the predicted value of the stop time may be notified to the vehicle. The vehicle automatically stops the engine based on the result, or provides the result to the driver and leaves the engine to the driver.

  In the case where the road device is configured, the road device collects information such as the time, position, and speed of the vehicle by communication with the vehicle, and from this information and the green signal start time of the corresponding intersection, The speed of the starting wave can be calculated. Accordingly, the predicted value of the stop time and the realization result are recorded, and based on this difference, the speed of the starting wave after the start of the green signal is corrected, or the correction coefficient for the speed of the starting wave is calculated. As a result, an accurate starting wave velocity can be obtained and used thereafter.

In addition, the engine stop control device of the present invention is obtained by multiplying the value obtained by adding the threshold value to the elapsed time from the start of the green signal at the downstream intersection to the downstream intersection from the vehicle. The limit distance to the stop line may be calculated, and the possibility of engine stop may be determined by comparing the distance L from the vehicle to the stop line at the downstream intersection with this limit distance. According to this apparatus, it is possible to perform control based on substantially the same conditions as in the above-described invention in which the predicted stop time is compared with the threshold value.

According to the engine stop control device the same invention as the present invention described on the following, engine stop control method are also included in the present invention.

  As described above, according to the present invention, the maximum exhaust gas reduction effect that does not cause a delay in traffic flow can be exhibited.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a graph showing the temporal variation of the queue length due to signal waiting. The horizontal axis represents time, and the vertical axis represents distance from the intersection.
When it becomes red, a signal queue is generated, and the queue length becomes longer with time. A wave that lengthens the queue length is called a “stop wave”. Next, when it switches to a green light, it starts to start from the vehicle ahead. This is called “starting wave”. Normally, the speed of the starting wave is higher than the speed of the stop wave, so that when the signal becomes green, the queue length decreases with time.

The running behavior when one vehicle enters the red light queue and stops, then becomes a blue light and starts to move with the starting wave is indicated by the symbol “a” in FIG. Further, the behavior of the vehicle that can pass the signal as it is without encountering the queue is indicated by a symbol “b”.
Here, a method of predicting the stop time due to waiting for a signal will be described.
FIG. 2 is an enlarged graph of FIG. At the current time t, the vehicle is stopped at a distance L from the stop line because it waits for a signal. The vehicle is stopped at that position during the red light, but cannot start immediately even when the green light starts, and will continue to stop until all the vehicles ahead start.

Accordingly, as shown in FIG. 2, the stop time (T) includes the time (Δt) from the current time t to the green signal start time tg, and the distance (L) from the vehicle to the stop line at the intersection. From the starting wave velocity (v) after the start of the green light, it can be seen that the following equation is obtained.
T = Δt + L / v (1)
The second term on the right side of this equation is the distance (L) to the stop line at the intersection divided by the speed (v) of the starting wave, and represents the starting delay time due to the starting wave.

In addition, there is a case where the distance (L) to the stop line at the intersection is long and the signal is waiting for the green light.
FIG. 3 is a graph showing such a case. In this graph, the current time t is later in time than the green light start time tg. Therefore,
Green light start time tg <current time t
The time (Δt) from the current time t to the green signal start time tg is negative. Even in this case, the equation (1) is established, and the stop time of the vehicle is expressed by the equation (1). The absolute value of the time (Δt) from the current time t to the green signal start time tg is equal to the elapsed time from the start of the green signal.

In Patent Document 2, a vehicle that waits for a signal at an intersection even after the start of a green signal is not taken into consideration. In such a case, the engine stop control cannot be performed. In the present invention, the stop time is also included in such a case. Is one of the advantages.
The engine stop control device of the present embodiment determines whether or not to perform idling stop based on the stop time (T) calculated as described above. The apparatus configuration for that purpose will be described in detail below.

First, an embodiment in the case where the stop time is determined by the in-vehicle device will be described.
FIG. 4 is a block diagram illustrating the in-vehicle device 2 that communicates with the road device 1. FIG. 5 is a road map showing the road from the vehicle to the intersection.
The in-vehicle device 2 includes a communication device 21 that communicates with the road device 1, an idling stop control device 22, a man-machine device 23 (such as a speaker), a distance sensor 24, and a clock (timer) 25.

On the road to the intersection, as shown in FIG. 5, the road device 1 is installed on the road side sufficiently before the intersection, and the in-vehicle device 2 includes the road device 1, an optical beacon, a radio beacon, DSRC, Alternatively, road-to-vehicle communication is performed using a communication method such as a wireless LAN.
The road device 1 measures various quantities for collecting traffic conditions such as traffic volume (number of vehicles passing per unit time), vehicle speed, occupation rate (occupation time), and the like. For this purpose, various measuring devices such as an ultrasonic sensor, an infrared sensor, and a television camera are provided.

Moreover, the road apparatus 1 may control a signal controller and a signal lamp. In addition, the roadside device 1 can communicate with the vehicle-mounted device 2 by a communication means such as an optical beacon, a radio wave beacon, DSRC, and a wireless LAN. It is equipped with facilities to provide vehicle occupants.
The in-vehicle device 2 sends the green signal start time (or the remaining time until the start of the green signal or the elapsed time since the start of the green signal) from the road device 1, the stop line position of the intersection (or the intersection at the communication point) Information on the speed of the starting wave after the start of the green light.

  Here, the “green signal” is not only a green signal indicating that the vehicle may go straight, but also a green signal in the form of a so-called right arrow (→) or left arrow (←) indicating that the vehicle may turn right or left. Shall be included. Further, the speed of the starting wave may be set for each of straight ahead, right turn, and left turn. Therefore, for example, at the intersection having a time difference signal indicated by the right arrow (→), the speed of the start wave applied to the vehicle waiting for the signal in the right turn exclusive lane is the speed of the start wave set for the right turn.

In addition, when the navigation apparatus is mounted on the vehicle, the information on the intersection line registered in the map information possessed by the vehicle and the vehicle may be obtained even if the information on the stop line position of the intersection is not obtained through communication with the road device 1. Alternatively, the position may be calculated from the position detection device 26.
On the basis of these pieces of information, the in-vehicle device 2 uses the clock or timer provided in the vehicle, the remaining time from the current time t to the start of the green signal (when Δt is positive), or the elapsed time after the start of the green signal (Δt Is negative).

The in-vehicle device 2 calculates the distance (L) from the current position to the stop line at the intersection.
When the in-vehicle device 2 can measure the position, the distance (L) from the current position to the stop line of the intersection can be calculated by obtaining the distance from the measured position to the stop line of the intersection.
In addition, when the in-vehicle device 2 cannot measure the position, and the road-to-vehicle communication method is a method that can not always communicate and can communicate only at a specific communication point such as a beacon or DSRC, By receiving the distance from the road device 1 to the stop line of the intersection at the specific communication point, and subtracting the travel distance from the specific communication point measured by the distance sensor 24 in the vehicle to the current position from the distance, the intersection from the current position The distance (L) to the stop line can be calculated.

  The speed (v) of the starting wave after the start of the green light is the vehicle environment / traffic characteristics at that time, for example, the mixing ratio of large vehicles, the difference in driver class, the weather such as the presence of rain, the morning / day / evening / night The vehicle-mounted device 2 should be obtained as real-time information by communication from the roadside device 1 because it may change slightly due to the time zone, road characteristics (road structure, presence or absence of curves, slopes, etc.), clogging due to traffic jams, etc. However, the accuracy set to some extent may be used, and an average constant value set by the in-vehicle device 2 may be used.

  The idling stop control device 22 of the in-vehicle device 2 determines the time (Δt) from the current time t to the green signal start time tg acquired as described above, the distance (L) to the stop line at the intersection, and the start of the green signal. The stop time (T) of the vehicle is calculated from the information on the starting wave velocity (v) using the above equation (1). Then, engine stop / start control is performed using the stop time (T).

Hereinafter, the engine stop / start control procedure will be described in detail using a flowchart.
FIG. 6 is a flowchart showing engine stop / start control.
The vehicle-mounted device 2 communicates with the road device 1 during traveling (step S1), and obtains and records information on the green signal start time, the distance to the stop line at the downstream intersection, and the speed of the starting wave (step S2).
Based on these pieces of information, the distance from the current vehicle position to the stop line is calculated (step S3).

If it is within a predetermined distance (for example, 200 m) to the stop line at the downstream intersection (step S4), the next process is started.
If the distance to the stop line at the intersection exceeds the predetermined distance Lu, there is a considerable distance from the stop line at the intersection, and the calculation accuracy of the stop time (T) is reduced. Therefore, the stop time (T) should not be calculated. ing. This is because there is a possibility that the start and stop of the vehicle may be repeated at a long period until it reaches the intersection, so that the prediction accuracy of the stop time may be lowered.

It is determined whether or not the vehicle has passed the stop line at the downstream intersection, and if not, whether the vehicle is stopped is monitored (step S5). If it passes the stop line of the downstream intersection, it is not necessary to calculate the stop time (T) in relation to the intersection, so various information obtained from the road device 1 until now is reset (step S7) and started. Return to.
Even when the vehicle is stopped, the vehicle may stop instantaneously due to slow running due to traffic jams. In consideration of this, in order to perform reliable stop determination, for example, it is monitored whether or not it has been continuously stopped for a predetermined time (for example, 2 seconds) (step S8).

When the vehicle is continuously stopped for a predetermined time or longer, the stop time T at the intersection of the vehicle is predicted according to the equation (1) (step S9).
Next, it is determined whether or not the predicted stop time T is a threshold value (for example, 10 seconds) or more (step S10).
If the predicted stop time (T) is equal to or greater than the threshold value, automatic idling stop is executed (step S11). If the predicted stop time (T) is not equal to or greater than the threshold value, idling stop is not performed.

Since this threshold value is considered to depend on the type of exhaust gas and the engine type, it should be a specific value for each vehicle. However, the current vehicle environmental conditions such as the use of an air conditioner, for example, whether or not an air conditioner is used, It may be changed depending on the driving time (distance), season, weather, time zone (time), temperature, road alignment, and the like.
For example, when using an air conditioner, a large burden is imposed on restart, so the threshold value is increased. Also, if the operating time (distance) up to that time is long, the lubrication of the engine is improved, so the restart is not burdened, so the threshold value is shortened. As for the weather, when it is raining, the start delay is larger than when the weather is fine, so the threshold is shortened. In the time zone immediately after twilight, the visibility is poor and the threshold is set longer from a psychological point of view. When the temperature is high, the engine start efficiency is good and the engine start efficiency is short. When the humidity is high, the engine start efficiency is poor and the time is long. Consider the possibility of vehicles that cannot be restarted in weather where the road surface freezes, and make it extremely long. Of the road alignment, the downhill is easy to start, so the uphill is long.

Next, the timing for releasing the idling stop will be described.
First, if there is an engine restart operation by the driver, then the idling stop is canceled and the engine is started (step S12). This is because priority is given to the judgment of the driver.
In addition, when the automatic engine restart device is mounted on the vehicle, even if the automatic engine restart device is activated (step S13), the fact that a predetermined time has elapsed since the vehicle stopped. Check and restart the engine.

If the predetermined time for the restart is set to the predicted value of the stop time, the driver feels uncomfortable and the traffic flow is delayed. For this reason, although it is automatically released by an operation of connecting a clutch in a bus or the like, it is considered necessary to start a passenger car a little earlier.
For example, when a time obtained by subtracting a predetermined time (for example, 3 seconds) from the predicted value of the stop time has elapsed, the idling stop is canceled even if the driver has not started the moving operation (step S14). When this configuration is followed, a predetermined time required for starting the engine is also added to the threshold value for stopping the engine. This is to prevent the fuel consumption from deteriorating because the calculated fuel consumption value becomes S1 <S2 by stopping the engine for a short time with respect to the predicted stop time by a predetermined time for starting the engine.

After starting the vehicle (step S16), it is preferable to compare the predicted value of the stop time with the actually stopped actual value, and calculate and record the correction coefficient of the starting wave velocity (step S17).
Hereinafter, this correction process will be described. When the constant value possessed by the in-vehicle device 2 is used as the starting wave velocity, the constant value is set in the direction in which the predicted value matches the actual value by comparing and evaluating the predicted value of the stop time with the actual value. to correct.

  For example, if the actual value of the stop time is expressed as Tr, the value of L / (Tr−Δt) is stored every time idling is stopped, and the moving average value (average value for the past predetermined number of times) or exponential smoothing is stored. A value (an average value obtained by weighting past values) may be adopted as the corrected starting wave velocity v. If a considerable number of L / (Tr−Δt) values are collected, an average value, a median value, a minimum value, or the like may be calculated at that stage, and this may be used as the starting wave velocity v. Alternatively, the obtained starting wave velocity may be divided by a constant value of the starting wave velocity v to obtain a correction coefficient, this correction coefficient may be stored, and the obtained starting wave speed may be multiplied by this correction coefficient.

  At this time, when the actual value of the stop time is considerably larger than the predicted value (the traffic jam at the downstream intersection is further clogged than the downstream intersection, the traffic volume at the downstream intersection cannot be made, and the starting wave is If the actual value of the stop time is considerably smaller than the predicted value (such as when it slows down due to traffic jams and then moves slightly after stopping), the data is excluded as an abnormal value. Also good.

In the procedure of the above flowchart, the idling stop is automatically executed. However, the idling stop execution may be left to the driver only by providing the driver with the timing information of the idling stop execution. In this case, the execution timing is provided to the driver, and the execution operation is performed by the driver.
FIG. 7 is a flowchart showing a procedure for providing timing information for executing the idling stop.

  Compared with the flowchart of FIG. 6, steps S1 to S10 are the same. After step S10, if the predicted stop time (T) is equal to or greater than the threshold value, the in-vehicle device 2 recommends to the driver that the vehicle should stop for a long time. (Step S21). Alternatively, the stop time itself may be provided as information, such as “How many seconds will be stopped from now on”.

After idling is stopped by the driver's operation (step S22), if there is an engine restart operation by the driver (step S23), the vehicle is started (step S26).
Further, if it is confirmed that a predetermined time has elapsed even if there is no engine restart operation (step S24), for example, "Please start the engine" provides information for restarting the engine ( Step S25).

The predetermined time for the restart is determined based on the same standard as S14 in FIG. That is, when the vehicle starts to start, the driver feels uncomfortable and the traffic flow is delayed. Therefore, the predetermined time (for example, 3 seconds) is subtracted from the predicted value of the stop time.
After the vehicle starts, it is preferable to compare the predicted value of the stop time with the actually measured value actually stopped, and calculate and record a correction coefficient for the start wave velocity v (step S27). This correction processing has been described in S17 of FIG.

Next, an embodiment in which the stop time is determined by the road device 1 will be described.
The case where it judges is demonstrated.
FIG. 8 is a block diagram showing the in-vehicle device 2 that communicates with the road device 1. FIG. 9 is a road map showing the road from the vehicle to the intersection.
The in-vehicle device 2 includes a communication device 21 that communicates with the road device 1, a position detection device 26 such as a navigation device, an idling stop control device 22, and a man-machine device 23.

On the road leading to the intersection, a road device 1 is installed on the road side near the intersection, and the in-vehicle device 2 performs road-vehicle communication with the road device 1 using a communication method such as a wireless LAN.
As described above (FIG. 4), the road device 1 has a function of measuring various amounts for collecting traffic conditions such as traffic volume, vehicle speed, occupation rate (occupation time), a signal control function, and the like. At the same time, information on the green signal start time at the intersection, the stop line position at the intersection, and the speed of the starting wave after the start of the green signal is stored.

The road device 1 receives vehicle position information from the in-vehicle device 2, and based on the position information of the in-vehicle device 2, the time (Δt) from the current time t of the vehicle stopped waiting for a signal to the green signal start time tg ), The distance to the stop line at the intersection (L), and the speed (v) of the starting wave after the start of the green light, the stop time (T) of the vehicle is calculated using the equation (1).
The road device 1 calculates the engine stop / start timing of the vehicle based on the information of the stop time (T) of the vehicle, and transmits the timing to the in-vehicle device 2 of the vehicle by road-to-vehicle communication.

Hereinafter, the engine stop / start control procedure will be described in detail using a flowchart.
FIG. 10 is a flowchart showing engine stop / start control of the in-vehicle device 2, and FIG. 11 is a flowchart showing engine stop / start control of the road device 1.
The in-vehicle device 2 monitors the stop of the vehicle (step T1). Even if the vehicle stops, it may stop instantaneously due to slow running due to traffic jams, so that it is stopped continuously for a predetermined time (for example, 2 seconds) or more in order to make a reliable stop determination, for example. It is determined whether or not (step T2).

If it stops continuously, it will be judged that the vehicle has stopped and the identification code of the said vehicle-mounted apparatus 2 and vehicle position information will be transmitted to the roadside apparatus 1 (step T3).
If the vehicle position information is transmitted from the in-vehicle device 2 (FIG. 11; step U1), the road device 1 calculates the distance from the current vehicle position to the stop line (step U2).
If it is within a predetermined distance (for example, 200 m) to the stop line at the downstream intersection (step U3), the green light start time, the distance to the stop line at the downstream intersection, the speed of the starting wave are calculated, and based on these information, A predicted value of the vehicle stop time is calculated (step U4). If the distance to the stop line at the intersection exceeds the predetermined distance, the stop time (T) is not calculated as in the above-described embodiment.

Next, it is determined whether or not the predicted stop time T is greater than or equal to a threshold value (for example, 10 seconds) (step U5).
If the predicted stop time (T) is greater than or equal to the threshold value, information recommending idling stop, information on engine restart timing, and information on the predicted stop time are sent to the in-vehicle device 2 (step U6). ).

If the predicted stop time (T) is less than the threshold value, information that does not stop idling is sent to the in-vehicle device 2 (step U7).
Next, if the vehicle-mounted apparatus 2 receives the information which recommends idling stop (FIG. 10; step T5), it will perform idling stop (step T6).
Next, if there is an engine restart operation by the driver, then the idling stop is canceled and the engine is started (steps T7 and T10). This is because priority is given to the judgment of the driver.

In addition, when the automatic engine restart device is mounted on the vehicle, even if the automatic engine restart device is activated (step T8), the fact that the predetermined time has elapsed since the vehicle stopped. After confirming, the engine is restarted (steps T9 and T10).
The timing for this restart is when the time obtained by subtracting a predetermined time (for example, 3 seconds) from the predicted value of the stop time has passed, as in the above-described embodiment.

In the flowcharts of FIGS. 10 and 11 described above, the idling stop is automatically executed. However, it is assumed that the idling stop execution is left to the driver only by providing the timing information of the idling stop. Also good. This procedure is as described with reference to FIG.
In addition, when the actual value of the stop time is available in the road device 1, the correction coefficient may be obtained by constantly evaluating the predicted value of the stop time and the actually stopped actual value. That is, after removing abnormal values by the same method as described above, L / (Tr−Δt) may be evaluated and the moving average value or exponential smoothing value may be adopted as the corrected starting wave velocity v. . If a considerable number of L / (Tr−Δt) values are collected, an average value, a median value, a minimum value, or the like may be calculated at that stage, and this may be used as the starting wave velocity v. This correction process is as described in S17 of FIG.

  Note that the measured value of the stop time is not always available for all vehicles equipped with the in-vehicle device 2, so the vehicle (probe car) having the configuration of FIG. 8 is run for the purpose of measuring the stop time. The actual measured value of the stop time may be obtained from the vehicle. In this configuration, the road device 1 collects information such as the time, the position of the vehicle, and the speed of the vehicle by communication with the vehicle, and based on this information, the actual signal stop time Tr of the vehicle and the intersection The distance L to the stop line is calculated. And the speed of the starting wave after a green signal start is calculated from these numerical values and the green signal start time of an intersection. By using the probe car in this way, it is possible to reliably obtain information on the speed of the starting wave after the start of the green signal.

There are also the following embodiments. The distance from the on-road device 1 to the stop line of the intersection where the idling stop should be performed, that is, the information on the limit value of the distance L that satisfies T = Δt + L / v ≧ threshold value, the in-vehicle device of each vehicle entering the intersection Each vehicle may adopt an embodiment in which the idling stop is executed when the distance to the stop line at the intersection is equal to or greater than the limit distance.

It is a graph which shows the time fluctuation of the queue length by signal waiting. It is the graph which expanded and expressed the stop wave and the starting wave. Since the queue length is long, it is a graph showing a state in which it cannot start even with a green light. It is a block diagram which shows the vehicle-mounted apparatus 2 which communicates with the road apparatus 1. FIG. It is a road map which shows the road from a vehicle to an intersection. 4 is a flowchart showing an engine stop / start control procedure in the in-vehicle device 2; 6 is a flowchart showing another type of engine stop / start control procedure in the in-vehicle device 2; It is a block diagram which shows the vehicle-mounted apparatus 2 which communicates with the road apparatus 1. FIG. It is a road map which shows the road from a vehicle to an intersection. It is a flowchart which shows a part of engine stop / start control procedure performed with the vehicle-mounted apparatus 2, 3 is a flowchart showing a part of an engine stop / start control procedure performed by the road device 1; It is a graph which shows the relationship between fuel consumption and time.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Road device 2 Vehicle 22 Idling stop control device 21 Communication device 23 Man-machine device 24 Distance sensor 25 Clock or timer 26 Position detection device

Claims (14)

In the engine stop control device for predicting the stop time until the vehicle starts to travel again when the vehicle stops with a green light and waits for the signal, and performs engine stop control based on the predicted stop time,
Traveling monitoring means for determining that the vehicle has stopped;
And the elapsed time from the start of the blue signal downstream intersection, from the start of the blue signal downstream of the intersection, Ru is calculated as the time progresses the starting wave distance L from the vehicle to the stop line of the downstream intersection A predicting means for predicting a stop time of the vehicle based on the start delay time;
Determination means for determining whether or not the engine can be stopped by comparing the stop time predicted by the prediction means with a threshold value;
An engine stop control device characterized in that the engine is stopped based on a result of the determination means or information to stop the engine is transmitted to a driver.   The engine stop control device according to claim 1, wherein the start delay time is represented by a function proportional to a distance L from the vehicle to a downstream intersection. The function is expressed as the velocity v of the starting wave after the start of the green light.
L / v
The engine stop control device according to claim 2.   The engine stop control device according to claim 1, wherein the travel monitoring unit determines stop of the vehicle on condition that the stop of the vehicle continues for a predetermined time.   The engine stop control device according to claim 1, wherein the determination means does not determine whether or not the engine can be stopped when the distance L to the stop line at the downstream intersection is longer than a predetermined distance.   The engine stop control device according to claim 1, wherein the threshold value is set according to presence / absence of use of an air conditioner, operation time (distance), season, weather, time zone (time), or temperature. The engine stop control device according to claim 1 mounted on a vehicle,
Means for receiving the information on the green signal start time, the distance from the communication point to the stop line of the downstream intersection, and the speed of the starting wave after the start of the green signal from the road device installed on the road side by road-to-vehicle communication;
Means for measuring the mileage of the vehicle;
An engine stop control device including means for calculating a distance L from the vehicle to the stop line at the downstream intersection based on the received distance from the communication point to the stop line at the downstream intersection and the measured travel distance. The engine stop control device according to claim 1, comprising an on-road device.
Receive vehicle location information from in-vehicle devices,
An engine stop control device that transmits information on a result of the determination unit from a road device to an in-vehicle device through road-to-vehicle communication, and stops an engine of the vehicle or transmits information on engine stop to a driver.   Claim: The road device collects information such as vehicle time, position, speed, etc. by communication with the vehicle, and calculates the speed of the starting wave after the start of the green signal from this information and the green signal start time of the corresponding intersection. The engine stop control device according to 1.   The engine stop according to claim 1, wherein the prediction result and the realization result of the stop time are recorded, and based on this difference, the speed of the starting wave after the start of the green signal is corrected, or a correction coefficient for the speed of the starting wave is calculated. Control device. In the engine stop control method for predicting the stop time until the vehicle starts to travel again when the vehicle stops with a green light and waits for the signal, and performs engine stop control based on the predicted stop time.
Determine that the vehicle has stopped,
If the vehicle is stopped, the elapsed time from the start of the blue signal downstream intersection, from the start of the blue signal downstream of the intersection, the distance L from the vehicle to the stop line of the downstream intersection starting wave progressed go on the basis of the Ru calculated start delay time as the time, the predicted stop time,
Determining whether the engine can be stopped by comparing the predicted stop time with a threshold value;
An engine stop control method, wherein the engine is stopped based on the determination result, or information on engine stop is transmitted to a driver. Vehicle is green light, when it stops at a traffic signal, the engine stop control device performing stop control of the engine,
Traveling monitoring means for determining that the vehicle has stopped;
Calculation to calculate the limit distance from the vehicle to the stop line at the downstream intersection obtained by multiplying the value obtained by adding a certain threshold to the elapsed time from the start of the green light at the downstream intersection to the speed of the starting wave Means,
And the distance L to the stop line downstream intersection from the said vehicle, and a determination means for determining whether the engine stop by comparing the critical distance,
An engine stop control device characterized in that the engine is stopped based on a result of the determination means or information to stop the engine is transmitted to a driver. Wherein the engine is started based on the stop time that is predicted by the prediction means, or the information to be starting the engine transmitted to the driver according to claim 1 Symbol placement of the engine stop control system. Vehicle is green light, when it stops at a traffic signal, the engine stop control method for performing stop control of the engine,
Determine that the vehicle has stopped,
Calculate the limit distance from the vehicle to the stop line at the downstream intersection , which is obtained by multiplying the value of the elapsed time since the start of the green light at the downstream intersection by adding the threshold value to the starting wave speed ,
The distance L from the said vehicle to a stop line of the downstream intersection determines whether the engine stop by comparing the critical distance,
An engine stop control method, wherein the engine is stopped based on the determination result, or information on engine stop is transmitted to a driver.

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