Driving assistance device, and driving assistance method

Abstract

To provide a driving assistance device and a driving assistance method for appropriately calling an attention about existence of an oncoming vehicle when there is no crossing with the oncoming vehicle for a comparatively long time.SOLUTION: A driving assistance device 17 raises an alarm to a driver of an own vehicle. The driving assistance device 17 comprises: an oncoming vehicle detection unit 31 which detects an oncoming vehicle traveling by facing the own vehicle under travel; and an alarm control unit 32 which outputs the alarm in predetermined timing when the oncoming vehicle to cross the own vehicle from now on is detected by the oncoming vehicle detection unit in a state in which the own vehicle does not cross the oncoming vehicle for first predetermined time or longer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a driving assistance device and a driving assistance method. [Background technology]

[0002] There is a vehicle navigation device that estimates and calculates the point where an oncoming vehicle detected by an oncoming vehicle detection function and the vehicle itself will pass each other, and displays the calculated passing point together with the oncoming vehicle (Patent Document 1).

[0003] This technology allows drivers to be aware of passing points and ensures safety. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-83508 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, if a driver does not pass an oncoming vehicle for a relatively long time while driving, he or she may lose concentration or develop an illusion of speed. As a result, for example, if the driver crosses the center line and an oncoming vehicle approaches at that time, it may lead to an accident.

[0006] The present invention has been made in consideration of such problems, and its purpose is to provide a driving assistance device and a driving assistance method that appropriately warn the driver when the next oncoming vehicle is to be passed when the vehicle has not passed an oncoming vehicle for a relatively long time. [Means for solving the problem]

[0007] A driving assistance device according to one aspect of the present invention is a driving assistance device that issues a warning to the driver of a vehicle, and includes an oncoming vehicle detection unit that detects an oncoming vehicle traveling in the opposite direction to the vehicle while the vehicle is traveling, and an alarm control unit that outputs an alarm at a predetermined timing when the oncoming vehicle detection unit detects an oncoming vehicle that is about to pass the vehicle when the vehicle has not passed the oncoming vehicle for a predetermined first time period or longer.

[0008] A driving assistance method according to one aspect of the present invention is a driving assistance method for issuing a warning to a vehicle driver, and includes an oncoming vehicle detection step for detecting an oncoming vehicle traveling in the opposite direction to the vehicle while the vehicle is traveling, and an alarm control step for outputting an alarm at a predetermined timing when the oncoming vehicle detection step detects an oncoming vehicle that is about to pass the vehicle when the vehicle has not passed the oncoming vehicle for a predetermined first time period or longer. [Effects of the Invention]

[0009] According to the present invention, when a vehicle has not passed an oncoming vehicle for a relatively long time, the driver can be appropriately warned when the vehicle next passes an oncoming vehicle. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram showing an example of the configuration of a driving assistance system 1. As shown in FIG. [Figure 2] FIG. 2 is a flowchart showing the warning process. [Figure 3] FIG. 3 is a diagram for explaining the warning process. [Figure 4] FIG. 4 is a flowchart showing another example of the warning process. DETAILED DESCRIPTION OF THE INVENTION

[0011] [One embodiment] 1 is a block diagram showing an example of the configuration of a driving assistance system 1 according to an embodiment of the present invention. The driving assistance system 1 can be installed in an in-vehicle device such as a drive recorder or car navigation system, or can be installed separately in a vehicle as a dedicated device.

[0012] If a vehicle does not pass an oncoming vehicle for a relatively long time while traveling, the driver's concentration may be distracted or an illusion of speed may occur. Therefore, if an oncoming vehicle is detected after a predetermined time or more has passed an oncoming vehicle, the driving assistance system 1 outputs an alarm and executes a process (hereinafter referred to as alarm process) to alert the driver.

[0013] (Configuration of driving assistance system 1) The driving assistance system 1 includes a video camera 11 , a display unit 12 , an audio output unit 13 , a position information acquisition unit 14 , an input operation unit 15 , a storage unit 16 , and a driving assistance device 17 .

[0014] The video camera 11 captures an image of the area in front of the vehicle, including the oncoming traffic lane.

[0015] The display unit 12 is, for example, a liquid crystal display or an organic EL (Electroluminescence) display device. The display unit 12 displays, for example, warning information for display supplied from the alarm control unit 32.

[0016] The audio output unit 13 is, for example, a speaker, and outputs the audio warning information supplied from the alarm control unit 32 as audio.

[0017] The position information acquisition unit 14 acquires the position information of the vehicle based on, for example, a signal received from a GPS (Global Positioning System) satellite, which is an example of a satellite positioning system GNSS (Global Navigation Satellite System). The position information includes the current time in addition to the longitude and latitude indicating the position of the vehicle at the time of detection by the GPS receiving unit.

[0018] The input operation unit 15 is, for example, a touch panel formed integrally with the display unit 12, and accepts input operations of various information from the driver, etc. The user interface may use known technology such as a touch panel, buttons, or acquisition via communication.

[0019] The storage unit 16 is an information recording device configured with a magnetic recording medium (e.g., a flexible disk, a magnetic tape, a hard disk drive), a magneto-optical recording medium (e.g., a magneto-optical disk), a semiconductor memory (e.g., an EPROM (Electrically Erasable Programmable Read-Only Memory), a flash ROM, a RAM), etc. The storage unit 16 stores an OS and various programs for controlling the overall operation of the driving assistance device 17, map information 21, etc.

[0020] The map information 21 includes, for example, road location information, road shape information (e.g., curves, types of straight sections, curvature of curves, etc.), road width information, road height information, intersection location information, merging point (merging section) location information, branching point location information, and building location information.

[0021] The driving support device 17 is connected to the video camera 11 to the storage unit 16 by wire or wirelessly, and is capable of transmitting and receiving various types of information. The driving support device 17 includes an arithmetic circuit such as a CPU (Central Processing Unit) and a storage circuit such as a RAM (Random Access Memory). The driving support device 17 reads and executes an information processing program stored in the storage unit 16, thereby functioning as an oncoming vehicle detection unit 31 and an alarm control unit 32, as shown in FIG. 1, and executing alarm processing.

[0022] The oncoming vehicle detection unit 31 detects oncoming vehicles from images captured by the video camera 11. Specifically, the oncoming vehicle detection unit 31 uses a well-known pattern matching method to identify the type of three-dimensional object and detect the oncoming vehicle. Depending on the installation position and performance of the video camera 11, the oncoming vehicle detection unit 31 detects the presence of an oncoming vehicle when the oncoming vehicle approaches, for example, several hundred meters ahead. Note that the oncoming vehicle detection unit 31 may also detect the oncoming vehicle through two-way communication with the oncoming vehicle.

[0023] When the oncoming vehicle detection unit 31 detects an oncoming vehicle, it estimates the position and time when the oncoming vehicle and the vehicle will pass each other. Specifically, the oncoming vehicle detection unit 31 tracks each frame of the video captured by the video camera 11, and calculates the speed and direction of travel of the detected oncoming vehicle based on the changes in the detected size and the changes in the detected position. The oncoming vehicle detection unit 31 then estimates the position and time when the oncoming vehicle and the vehicle will pass each other based on the calculated speed and direction of travel of the oncoming vehicle and the speed and direction of the vehicle. The oncoming vehicle detection unit 31 acquires vehicle information through an in-vehicle network such as a Controller Area Network (CAN) of the vehicle. Since the vehicle information includes vehicle speed information, the oncoming vehicle detection unit 31 calculates the traveling speed of the vehicle based on that information. The oncoming vehicle detection unit 31 appropriately acquires position information of the vehicle from the position information acquisition unit 14 and calculates the traveling direction of the vehicle.

[0024] The processes of detecting an oncoming vehicle and estimating the passing position and time in the oncoming vehicle detection unit 31 are collectively referred to as oncoming vehicle detection process when there is no need to distinguish between them individually.

[0025] When the oncoming vehicle detection unit 31 detects an oncoming vehicle that will soon pass the host vehicle in a state in which the host vehicle has not passed an oncoming vehicle for a predetermined time (hereinafter referred to as a first time) or more, the warning control unit 32 outputs a warning at a predetermined time (hereinafter referred to as a second time) before the time that the oncoming vehicle detection unit 31 estimates that the host vehicle will pass the oncoming vehicle.

[0026] When the driving assistance system 1 is provided as one component in a drive recorder or car navigation system, the components from the video camera 11 to the storage unit 16 also function as components of the drive recorder or car navigation system.

[0027] (Alarm processing) 2 is a flowchart showing the warning process of the driving assistance device 17. The warning process can be started by a user performing a predetermined operation on the input operation unit 15, or can be started automatically when the engine starts.

[0028] In step S11, the alarm control unit 32 starts a clock (not shown) to begin measuring time.

[0029] In step S12, the oncoming vehicle detection unit 31 determines whether or not an oncoming vehicle has passed. It is assumed that the oncoming vehicle detection unit 31 has started the oncoming vehicle detection process at or before the timing of step S11. If it is determined in step S12 that an oncoming vehicle has passed, the warning control unit 32 resets the clock in step S13, returns to step S11, and resumes measuring time.

[0030] If it is determined in step S12 that an oncoming vehicle has not passed, then in step S14 the warning control unit 32 determines whether a first time period (e.g., 30 minutes) has elapsed since the start of time measurement. If it is determined in step S14 that 30 minutes have not yet elapsed, the process returns to step S12.

[0031] If it is determined in step S14 that 30 minutes have passed, in step S15 the warning control unit 32 waits until an oncoming vehicle is detected by the oncoming vehicle detection unit 31, and if an oncoming vehicle is detected, the process proceeds to step S16. In step S16, the warning control unit 32 outputs a warning at a timing that is a second time before (for example, 3 seconds before) the time that the host vehicle will pass the oncoming vehicle, which is estimated by the oncoming vehicle detection unit 31.

[0032] Thereafter, the process returns to step S13, and the same process is repeated.

[0033] The warning process can be terminated when the user performs a predetermined operation on the input operation unit 15, or when the power supply to the vehicle accessories is turned off.

[0034] By executing the above-described warning process, for example, as shown in FIG. 3A, when the vehicle X is traveling on a road and does not pass an oncoming vehicle for 30 minutes or more (step S14), if the presence of an oncoming vehicle Y is detected (step S15) as shown in FIG. 3B, a warning is output three seconds before the vehicle passes the oncoming vehicle Y as shown in FIG. 3C (step S16).

[0035] [Other embodiments] (Definition of oncoming vehicle) As shown in FIG. 3C, oncoming vehicles can be vehicles traveling from the opposite lane to the lane in which vehicle X is traveling, as well as vehicles that are expected to pass each other when turning at an intersection or corner.

[0036] (curve) In the above-described embodiment, the driving support device 17 outputs a warning to alert the driver when there is no passing by an oncoming vehicle for a relatively long time.

[0037] However, even if there is no oncoming vehicle for a relatively long time, if the vehicle is traveling on a curved road, the driver's concentration is less likely to be distracted or the driver is less likely to experience an illusion of speed. If an alarm is output to the driver even when traveling on a curved road, the driver may find it annoying and it may interfere with driving.

[0038] Therefore, the warning control unit 32 can output a warning when there is no passing of an oncoming vehicle for a relatively long time and when the vehicle is traveling on a so-called straight road with a low curvature. The curvature of a curve refers to the degree of curvature of the curve and is a value obtained by dividing 1 by the radius of curvature. A road with a curvature of a curve equal to or less than a predetermined value is a road with a gentle curve and is a relatively straight road.

[0039] This will be described in detail with reference to Fig. 4. Fig. 4 is a flowchart showing another example of the warning process of the driving support device 17.

[0040] Steps S21 to S25 are the same as steps S11 to S15 in FIG. 2, and therefore their explanation will be omitted.

[0041] In step S26, the warning control unit 32 determines whether the curvature of the road curve at the position where the host vehicle will pass the oncoming vehicle is equal to or less than a predetermined value, i.e., whether the host vehicle is traveling on a straight road. Specifically, the warning control unit 32 obtains the curvature of the road curve at the position calculated by the oncoming vehicle detection unit 31 from the map information 21 in the memory unit 16, and determines whether the curvature is equal to or less than a predetermined value. The warning control unit 32 may obtain the curvature of the road curve on which the host vehicle is traveling based on an image of the road included in an image captured by the video camera 11.

[0042] If it is determined in step S26 that the curvature of the road curve at the position where the vehicle passes the oncoming vehicle is not equal to or less than the predetermined value, the process skips step S27, returns to step S23, and the time measurement is reset.

[0043] If it is determined in step S26 that the curvature of the road curve at the position where the vehicle will pass the oncoming vehicle is equal to or less than a predetermined value, i.e., the vehicle is traveling on a straight road, then in step S27 the warning control unit 32 outputs a warning 3 seconds before the vehicle passes the oncoming vehicle.

[0044] (Other examples of road conditions) Even if the road is not curved to the left or right, when driving on a steep slope, i.e., downhill or uphill, the driver drives carefully, so their concentration is less likely to be distracted and they are less likely to have an illusion of speed.

[0045] Therefore, in steps S26 and S27 of the warning processing in Figure 4, the warning control unit 32 may be configured to output a warning only when the curve curvature is less than a predetermined value and the slope is less than a predetermined magnitude on the road at the position where the vehicle passes an oncoming vehicle.

[0046] [Variations] (Another example of oncoming vehicle detection) In the above-described embodiment, oncoming vehicles are detected from images captured by the video camera 11, but a radar that senses the area including the oncoming lane ahead of the vehicle may be provided in addition to or instead of the video camera 11.

[0047] (First time determination method) In the above-described embodiment, the first period of time is set to 30 minutes, but the length of the first period of time can be changed depending on the external environment of the vehicle while it is traveling.

[0048] For example, at night, the driver may be prone to drowsiness and lose concentration, so it may be desirable to output a warning earlier than during the day. Therefore, when the warning control unit 32 determines that the current time is nighttime based on the current time acquired by the position information acquisition unit 14, the warning control unit 32 may shorten the length of the first period of time.

[0049] Furthermore, even after a meal, the driver may lose concentration due to drowsiness, so it may be desirable to output the warning earlier. Therefore, the driver may set that the driver has just eaten via the input operation unit 15, and when the warning control unit 32 determines that the driver has just eaten based on that setting, it may adjust the length of the first period to be shorter. The warning control unit 32 may also determine whether the driver has just eaten based on the current time.

[0050] Furthermore, even when the cabin temperature is high, drowsiness may cause a loss of concentration, so it may be desirable to output the warning earlier. Therefore, the warning control unit 32 may shorten the length of the first period when it determines that the cabin temperature is high based on the measurement result of a cabin thermometer installed in the vehicle.

[0051] (Another example of oncoming vehicle warning processing) In the above-described embodiment, the warning control unit 32 outputs a warning via at least one of the display unit 12 and the audio output unit 13. However, the driver may continue to drive unstably, for example, crossing the center line, even after the warning is issued. In this case, the warning control unit 32 may use a known driver monitoring system or the like to apply the brakes or operate the steering wheel to avoid danger.

[0052] In the above-described embodiment, the warning control unit 32 outputs a warning when the vehicle is traveling on a straight road with few oncoming vehicles, but the warning may be output only when the vehicle is traveling at the front of a line of vehicles, because the risk of a head-on collision is low when there is a vehicle traveling in front of the vehicle.

[0053] [Supplementary explanation of the embodiment] The above-described embodiments each show a preferred specific example of the present invention. The numerical values, components, arrangement positions and connection order of components, processing order in flowcharts, etc. shown in the following embodiments are merely examples and are not intended to limit the present invention. Furthermore, each figure is not necessarily a strict illustration.

[0054] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments.

[0055] The above-described series of processes can be executed by hardware or software. When the series of processes is executed by software, the program constituting the software is installed from a program recording medium into a computer incorporated in dedicated hardware, or into, for example, a general-purpose personal computer that can execute various functions by installing various programs.

[0056] The program executed by the computer may be a program that processes in chronological order according to the order described in this specification, or may be a program that processes in parallel or at the required timing, such as when called.

[0057] [Note] The contents of the above-described embodiments can be understood, for example, as follows.

[0058] (1) The driving assistance device 17 described above is A driving assistance device 17 that warns the driver of the vehicle, an oncoming vehicle detection unit 31 that detects oncoming vehicles traveling in the opposite direction to the vehicle; an alarm control unit that outputs an alarm at a predetermined timing when an oncoming vehicle that is about to pass the vehicle is detected by an oncoming vehicle detection unit 31 in a state where the vehicle has not passed an oncoming vehicle for a predetermined first time period or more; Equipped with.

[0059] If a vehicle does not pass an oncoming vehicle for a relatively long time while it is traveling, it may distract the driver or cause an illusion of speed, which may lead to the driver crossing the center line, for example. Therefore, if an oncoming vehicle that is about to pass the vehicle is detected when the vehicle has not passed an oncoming vehicle for the first time period or longer, an alarm is output at a predetermined timing, so that the driver can be warned appropriately.

[0060] There is also a lane keeping assist system (LKAS (registered trademark)) that recognizes the center line and assists driving, but it may not work effectively on farm roads without center lines or when the center line of the road has disappeared. However, by issuing an alarm in this way, it is possible to prevent accidents such as collisions with oncoming vehicles.

[0061] In addition, by setting the first time period to a time period during which concentration may be distracted or an illusion of speed may occur when driving without passing an oncoming vehicle, it is possible to prevent unnecessary warnings from being issued.

[0062] (2) Timing of warning In the driving assistance device 17 described above, The oncoming vehicle detection unit 31 estimates the time when an oncoming vehicle will pass the host vehicle, The warning control unit 32 outputs a warning a predetermined second time before the time estimated by the oncoming vehicle detection unit 31. It is possible.

[0063] With this configuration, the driver notices that he or she will pass an oncoming vehicle a predetermined second time before the time when the oncoming vehicle passes his or her own vehicle, so that even if the driver is traveling beyond the center line, he or she can return to the center line in advance.

[0064] (3) Alerts only when driving in a straight line In the driving assistance device 17 described above, The alarm control unit 32 can output a predetermined alarm when the oncoming vehicle detection unit 31 detects an oncoming vehicle that is about to pass the vehicle when the vehicle has not passed an oncoming vehicle for a first time period or more, and the curvature of the curve of the road on which the vehicle is traveling is equal to or less than a predetermined value.

[0065] When a vehicle is traveling on a so-called straight road with a relatively low curvature, the driver may lose concentration or experience an illusion of speed. In other words, even if there are few oncoming vehicles on a road with sharp curves, the driver is less likely to lose concentration or experience an illusion of speed. Therefore, if a warning is output even when the vehicle is traveling on a road with sharp curves, the driver may find the warning annoying and experience difficulty in driving.

[0066] Therefore, by having the above-mentioned configuration, the driving assistance device 17 is configured to appropriately output an alarm about the presence of an oncoming vehicle when traveling on a road with few oncoming vehicles and a straight road with a relatively low curvature, so that the user can be more appropriately warned.

[0067] (4) The time during which no oncoming vehicles pass each other consecutively In the driving assistance device 17 described above, The warning control unit 32 adjusts the length of the first time period depending on the external environment of the vehicle while it is running. It is possible.

[0068] With this configuration, the first time period can be adjusted to a time when the driver's concentration is likely to be distracted or an illusion of speed may occur depending on the external environment, so that the driver can be warned at an appropriate frequency. For example, since the driver's concentration may be impaired due to drowsiness, the warning can be output earlier at night. [Explanation of symbols]

[0069] 1. Driving assistance systems 11. Video camera 12 Display section 13 Audio output section 14 Location information acquisition section 15 Input operation section 16 Memory section 17 Driving assistance devices 21 Map Information 31 Oncoming vehicle detection unit 32 Alarm control section

Claims

1. A driving assistance device that warns a driver of a vehicle, an oncoming vehicle detection unit that detects oncoming vehicles traveling in the opposite direction to the vehicle; an alarm control unit that outputs an alarm at a predetermined timing when the oncoming vehicle that is about to pass the host vehicle is detected by the oncoming vehicle detection unit in a state where the host vehicle has not passed the oncoming vehicle for a predetermined first time period or more; Equipped with A driving assistance device characterized by:

2. The driving assistance device according to claim 1, the oncoming vehicle detection unit estimates a time when the oncoming vehicle will pass the host vehicle; The warning control unit outputs the warning a predetermined second time before the time estimated by the oncoming vehicle detection unit. A driving assistance device characterized by:

3. The driving assistance device according to claim 1 or 2, The warning control unit outputs the warning when the oncoming vehicle detection unit detects an oncoming vehicle that will soon pass the host vehicle while the host vehicle has not passed the oncoming vehicle for the first time period or longer, and when the curvature of a curve on a road on which the host vehicle is traveling is equal to or smaller than a predetermined value. A driving assistance device characterized by:

4. The driving assistance device according to claim 1 or 2, The warning control unit adjusts the length of the first time period depending on an external environment of the vehicle while it is running. A driving assistance device characterized by:

5. A driving assistance method for warning a driver of a vehicle, comprising: an oncoming vehicle detection step of detecting an oncoming vehicle traveling in the opposite direction to the own vehicle; an alarm control step of outputting an alarm at a predetermined timing when the oncoming vehicle that is about to pass the host vehicle is detected by the oncoming vehicle detection step in a state where the host vehicle has not passed the oncoming vehicle for a predetermined first time period or more; Contains A driving assistance method comprising:

Images