JP2010244308A - Device for supporting driving of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for supporting driving to promote early slowdown by notifying the driver of which point of time the driver should start the decelerating operation when the vehicle should stop at a traffic light. <P>SOLUTION: The device for supporting the driving of a vehicle is configured to calculate an arrival time to the next traffic light on the traveling direction of the vehicle, and to detect a time until a traffic light changes from green to yellow or to red. When an arrival time is equal to or more than a time until the traffic light changes, the driver of the vehicle is notified of the result. The driver who has received the notification is able to quickly start a deceleration operation by recognizing that it is difficult to pass while the traffic light is blue. Thus, it is possible to achieve a driving operation with much more satisfactory fuel consumption by clarifying a timing when the decelerating operation should be started from the notification. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an apparatus for assisting driving so as to achieve better fuel consumption until reaching a traffic light.

  Patent Document 1 below describes that in a hybrid vehicle, when the vehicle is decelerating, the stop of the vehicle is estimated, and based on the result of the estimation, whether to stop or stop the fuel supply is described. It is also described that when the stop is estimated, the gear ratio is controlled so that the engine speed is maintained so that the fuel cut can be maintained.

JP 2000-154742 A

  When there is a traffic light in front of the vehicle, if it is difficult to pass the traffic light during the blue, to slow down at the traffic light, the foot is gradually decelerated by moving away from the accelerator pedal as soon as possible. It is preferable from the viewpoint of fuel consumption.

However, it is difficult for the driver to grasp the distance to the traffic signal ahead and the timing of signal change. As a result, it is impossible to determine when to start deceleration, and as a result, turning off the accelerator pedal may be delayed, resulting in a reduction in fuel consumption. Also, in a hybrid vehicle equipped with an internal combustion engine and a motor / generator as power sources, In this case, the deceleration energy is regenerated in the battery when the vehicle decelerates. In order to improve the efficiency of regeneration, it is preferable to determine whether or not the vehicle is decelerating for stopping as soon as possible. With respect to this point, in Patent Document 1, since it is estimated whether the vehicle stops after actually starting deceleration, there is a possibility that the deceleration energy cannot be sufficiently regenerated.

  Accordingly, an object of the present invention is to provide a device for assisting driving so as to prompt the driver to promptly decelerate the vehicle by notifying the driver of when to decelerate when the traffic light should be stopped. It is to be.

  According to one aspect of the present invention, an apparatus for assisting driving of a vehicle has means for calculating an arrival time to the next traffic light in the traveling direction of the vehicle, and the traffic light changes from blue to yellow or red. And means for notifying a driver of the vehicle when the arrival time is larger than the time until the change.

  According to the present invention, the driver is notified when the arrival time of the signal is longer than the time when the signal changes from blue to yellow or red. That is, the driver is notified when it is determined that the signal cannot be passed during the blue period. Therefore, since the driver can start the deceleration operation in response to this notification, the driver can stop more safely with a signal and can start the deceleration operation at an appropriate timing for stopping with the signal. it can. As a result, better fuel efficiency driving operation can be realized. Further, since it is clear at which timing the vehicle should be decelerated, when the vehicle is a hybrid vehicle, the deceleration energy can be sufficiently regenerated during deceleration for stopping.

  According to an embodiment of the present invention, the arrival time is set so as to include a margin time, and the margin time is set to be larger as the distance from the current position of the vehicle to the traffic signal is larger.

  The longer the distance to the traffic light, the shorter the arrival time due to the subsequent increase in the vehicle speed, and the higher the possibility of passing the traffic light during the blue period. According to the present invention, the longer the distance to the traffic light is, the larger the margin time is used, so that the notification to the driver is suppressed even though the traffic light can pass through the blue. can do.

  According to an embodiment of the present invention, the apparatus includes an acceleration limiting unit that limits the acceleration of the vehicle after performing the above notification. By performing such acceleration limitation, it is possible to suppress a driving operation that attempts to pass a signal after the driver performs an accelerating operation and turns red after notification.

  According to one embodiment of the present invention, the acceleration limiting means limits the acceleration of the vehicle when the vehicle speed is equal to or higher than a predetermined value. According to the present invention, it is possible to prevent the acceleration from being restricted when the vehicle speed is low.

  Other features and advantages of the present invention will be apparent from the detailed description that follows.

The block diagram of the driving assistance device according to one Example of this invention. The figure for demonstrating the signal apparatus and signal transmission apparatus according to one Example of this invention. The flowchart of the driving assistance process according to one Example of this invention. The figure which shows the table for calculating | requiring the allowance time (alpha) according to one Example of this invention.

  Next, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of a driving assistance apparatus 10 equipped with a vehicle navigation function mounted on a vehicle according to an embodiment of the present invention. The apparatus 10 includes a current position detection unit 11, a map information storage unit 12, a processing unit 13, an input device 14, a display device 15, and a speaker 16.

  The current position detection unit 11 is used to improve positioning accuracy by correcting a GPS signal error using, for example, an appropriate base station or a GPS signal for measuring the position of the vehicle using an artificial satellite. A positioning signal receiving unit 21 that receives a positioning signal such as a D (differential) GPS signal, and a vehicle orientation in a horizontal plane and a tilt angle with respect to a vertical direction (for example, a tilt angle with respect to a vertical direction of a vehicle longitudinal axis and a vehicle gravity center And a gyro sensor 22 for detecting the amount of change in the tilt angle (for example, the yaw rate) and a vehicle speed sensor 23 for detecting the vehicle speed (vehicle speed). The current position detection unit 11 calculates the current position of the vehicle by the received positioning signal or by an autonomous navigation calculation process based on detection signals such as the vehicle speed and the yaw rate. The current position of the vehicle detected in this way is passed to the processing unit 13.

  The map information storage unit 12 can be realized in any storage device (storage medium, hard disk drive, etc.) and stores map information. The map information includes data necessary for drawing a map image on the display screen of the display device 15. For example, map information includes topographic map data, polygon data corresponding to various facilities, city blocks, lakes, etc., character data such as facility names and place names associated with each polygon, and data of various symbols. It has. Further, the map information includes road data indicating information related to road connection states. The road data includes, for example, nodes (coordinate points that become nodes such as intersections), links (minimum units of travel paths) that are lines connecting the nodes, and distances of the links. Further, the road data includes position information where the traffic lights are arranged.

  The processing unit 13 can be realized by an electronic control unit (ECU) that is a computer including a central processing unit (CPU) and a memory. The input device 14 is a device that can input data by the occupant, and the data input through the input device 14 is passed to the processing unit 13. A part of the result processed by the processing unit 13 is displayed on the display device 15 so that the occupant can view it, and / or is output as sound or sound through the speaker 16.

  In this embodiment, the display screen of the display device 15 is composed of a touch panel that functions as the input device 14, and an occupant can input a destination via the touch panel. The processing unit 13 realizes a navigation function that searches for the optimum route from the current position to the destination based on the map information and displays it on the display screen.

  The device 10 also includes a communication unit 17 that communicates with the outside. The communication unit 17 receives the signal information transmitted from the signal transmission device 31 and passes the received information to the processing unit 13.

  Here, as shown in FIG. 2, the signal transmission device 31 is provided in each traffic signal 100 installed on the road (the location provided in the traffic signal may be arbitrary, and is not limited to the form shown in the figure). Information, i.e., signal information, is constantly transmitted. The signal information includes information such as the current lighting color of the signal, the lighting time of each lighting color, and the waiting time until the next color is changed.

  Preferably, in order to identify each traffic signal, each traffic signal is assigned a unique ID (identifier), and signal information is transmitted together with the ID. On the other hand, in the map information, data representing the ID is stored in association with each traffic light. Therefore, the processing unit 13 identifies the ID of the traffic signal 100 immediately before in the traveling direction from the current position of the vehicle V based on the map information, and the ID is attached to the signal information received by the communication unit 17. Only signal information can be selected and processed. By doing in this way, even if there is a traffic signal with another ID near the current position of the vehicle, the traffic signal ID does not match the traffic signal ID existing in front of the vehicle. It is possible to prevent erroneous signal information processing.

  Based on the signal information of the traffic light 100 in front of the vehicle acquired in this way, the waiting time until the color changes from blue to yellow or red can be acquired.

  In this embodiment, as described above, the signal information is acquired from the signal transmitter 31 provided in each traffic light. However, the signal information may be acquired by any other appropriate means. For example, the vehicle may include a communication unit that performs wireless communication with a predetermined server that controls switching of lighting of each traffic signal, and signal information of each traffic signal may be acquired from the server via the communication unit. Good. For example, by transmitting the current position of the vehicle or the ID of the nearest traffic signal ahead of the vehicle to the server, the server can return the signal information of the traffic signal to the vehicle.

  Further, a probe system may be used. In the probe system, each running vehicle becomes a sensor (probe), and probe information such as a running locus and speed measured by the vehicle is collected in a predetermined server (center). The server accumulates probe information from a plurality of vehicles, and calculates the travel time and stop time at the position of each traffic light. The server can determine the signal switching timing by calculating the lighting time of the green light and the lighting time of the yellow and red signals, respectively, based on the travel time and the stop time. In this way, the server can transmit to the vehicle signal information indicating the time until the next traffic light changes to the next color for the nearest traffic light in front of the vehicle.

  As will be described in detail later, the processing unit 13 realizes a function (driving support function) that supports driving of the vehicle based on the signal information. In one embodiment, a predetermined switch is provided as the input device 14, and the driving support function is enabled in response to the switch being selected by the occupant, and in response to the selection of the switch being released. The driving support function can be disabled.

  Further, an engine control unit 33 that controls the engine of the vehicle is connected to the processing unit 13, and the engine control unit 33 is an electronic control device that is a computer including a central processing unit and a memory, like the processing unit 13. (ECU) can be realized. The engine control unit 33 operates to limit the acceleration operation of the vehicle according to the instruction from the processing unit 13. Specifically, when an instruction signal for limiting the acceleration of the vehicle is received from the processing unit 13, the engine of the vehicle is controlled to execute an operation for limiting the acceleration. This can be realized, for example, by limiting the amount of intake air to the engine or limiting the amount of fuel supply. The intake air amount may be controlled by the opening degree of the throttle valve. When a variable valve mechanism that can make the lift amount of the intake valve variable is provided, the intake air amount is controlled by the lift amount. Also good. In the case of a vehicle that also uses a motor, such as a hybrid vehicle, the acceleration operation may be limited through the control of the motor. Of course, the acceleration operation may be limited by using both engine control and motor control.

  FIG. 3 shows a process flow executed by the processing unit 13. This process is performed repeatedly at predetermined time intervals (eg, 100 milliseconds).

  In step S11, it is determined whether or not the switch for the driving support function described above has been selected by the user. If it is selected (S11 is Yes), it indicates that the driving support function has been activated, and thus the process proceeds to step S12. If the switch is not selected (S11 is No), the driving support function remains disabled, and the process is exited.

  In step S12, signal information transmitted from the signal transmitter 31 provided in the nearest traffic signal 100 in the traveling direction of the vehicle is received, and from the signal information until the traffic signal next changes from blue to yellow Get the time. In the case of a traffic light in which yellow does not exist, the time until the next change from blue to red is acquired. Here, when the signal is already red or yellow at the present time, the time is set to “0 (zero)”.

  In step S13, by referring to the map information based on the current position of the vehicle detected by the current position detecting unit 11, the distance from the current position to the position of the nearest traffic signal 100 in the traveling direction of the vehicle is acquired. To do. By dividing the acquired distance by the current vehicle speed detected via the vehicle speed sensor 23, a time (arrival time) until the vehicle reaches the position of the traffic light 100 is calculated.

  Preferably, in step S14, a margin time α is subtracted from the calculated arrival time (ie, arrival time−α). More preferably, the margin time α is determined according to the distance to the position of the traffic light. Referring to FIG. 4, there is shown an example of a table in which a margin time α with respect to the distance to the traffic light is set, and the margin time α is set to increase as the distance increases. Such a table is stored in a storage device such as a memory, the table is referred to based on the distance calculated in step S13, a corresponding margin time α is obtained, and this is subtracted from the arrival time.

  In step S15, the arrival time obtained by subtracting the margin time α is compared with the time (hereinafter referred to as change time) acquired in step S12 until the color changes from blue to yellow or red. If the arrival time from which the margin time α is subtracted is equal to or shorter than the change time (No in S15), the vehicle indicates that the signal can pass through the traffic light in a blue state, so the process exits as it is. .

  On the other hand, if the arrival time from which the margin time α is subtracted is longer than the change time (Yes in S15), it indicates that it is difficult for the vehicle to reach the position of the traffic light while it is blue. Therefore, in step S16, since the signal changes, a notification for prompting the driver to start deceleration is performed. Notification can be realized in any form. For example, it is possible to output an alarm sound through the speaker 16, notify that the signal is changed by sound, or notify the user to start deceleration. In addition, a predetermined lamp can be turned on or blinked, a signal change can be displayed on the display screen of the display device 15, or a display for prompting the start of deceleration can be performed. As described above, the process is repeatedly executed. However, in the case of notification by voice, it is preferable to set the notification to be performed only once.

  In step S17, the current vehicle speed of the vehicle is acquired via the vehicle speed sensor 23, and it is determined whether or not the vehicle speed is equal to or higher than a predetermined value (set to a low value, for example, 10 kilometers per hour). If the vehicle speed is equal to or higher than the predetermined value (Yes in S17), the process proceeds to step S18 to instruct the engine control unit 33 to execute an operation for limiting acceleration. In response to this, the engine control unit 33 prevents the speed from the current vehicle speed from increasing through the control such as limiting the intake air amount or limiting the fuel supply amount, as described above. The engine is controlled so as not to accelerate. Alternatively, the acceleration limiting operation may be executed so that the vehicle speed becomes smaller than the predetermined value. In this case, if the current vehicle speed is equal to or higher than the predetermined value, the engine is controlled so that the vehicle speed becomes smaller than the predetermined value. As described above, the acceleration limiting operation may be executed using motor control instead of engine control or in addition to engine control.

  The reason for limiting the acceleration is as follows. That is, if the signal is blue after actually receiving the notification in step S16, depending on the driver, there is a possibility that the driver will try to pass through the traffic light by acceleration. However, the notification in step S16 indicates that it is difficult to pass the traffic light between blue. In such a state, forcibly passing the traffic light by acceleration is not a preferable driving operation, and there is a possibility that the fuel consumption may be reduced. Therefore, the acceleration operation is limited by controlling the engine. Thereby, even if the driver increases the depression of the accelerator pedal, the acceleration of the vehicle is suppressed by the operation of the engine control unit 33.

  On the other hand, if the vehicle speed is smaller than the predetermined value in step S17 (No in S17), the vehicle speed is sufficiently low, and it is not necessary to limit the acceleration to such a case, so the process is exited.

  In this way, when it is determined that it is difficult to pass the traffic light while the signal is blue, the driver is notified, so the driver does not pass the traffic light as it is, It can be recognized that the deceleration operation for stopping should be started. Since the timing of the start of deceleration is informed by the device, the driver can take his foot off the accelerator pedal early to start the deceleration operation, thus saving fuel consumption.

  The process is repeated at predetermined time intervals as described above. Therefore, assuming that the current signal is blue, as long as the determination in step S15 is Yes, the notification to the driver as described above (step S16) is made until the signal changes from blue to red and then turns blue again. It is executed continuously. Similarly, the acceleration limiting operation (step S18) is continuously executed until the color becomes blue again as long as the determinations in steps S15 and S17 are Yes. Therefore, when the signal is red, it is possible to prevent the driver from accelerating by giving up that it will soon turn blue.

  In addition, by setting the margin time α, it is impossible to pass the traffic light by executing the notification and the acceleration limiting operation, even though the traffic light can originally pass the traffic light during blue. Can be suppressed. In particular, when the distance to the traffic light is large, if the vehicle speed subsequently increases, the arrival time is shortened, and thus there is a possibility that the traffic light can pass through during blue. In this case, as the distance to the traffic signal increases, the amount of reduction in arrival time may increase, and the above situation is likely to occur. Therefore, the margin time α is increased as the distance to the traffic signal increases. Thereby, such a situation can be suppressed.

  As described above, specific embodiments of the present invention have been described. However, the present invention is not limited to these embodiments.

11 current position detector 13 processing unit 33 engine control unit

Claims (4)

A device for supporting driving of a vehicle,
Means for calculating an arrival time to reach the traffic signal based on the distance from the current position of the vehicle to the next traffic signal in the traveling direction of the vehicle and the speed of the vehicle;
Means for obtaining a time until the traffic light changes from blue to yellow or red;
A notification means for notifying a driver of the vehicle when the arrival time is larger than the time until the change;
An apparatus comprising: The arrival time is set to include a margin time, and the margin time is set to be larger as the distance from the current position of the vehicle to the traffic light is larger.
The apparatus of claim 1. An acceleration limiting means for limiting acceleration of the vehicle after performing the notification;
The apparatus according to claim 1 or 2. The acceleration limiting means limits the acceleration of the vehicle when the vehicle speed is equal to or higher than a predetermined value.
The apparatus of claim 3.

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