Driving support device, driving support processing method and computer program

Abstract

To provide an appropriate support corresponding to a range level of a decision of a movement destination candidate in a scene where a driver is faced with a decision of a driving action of a vehicle subjected to the support.SOLUTION: A driving support device calculates decision time allowance that is a time for a vehicle until starting a planned action based on information of the planned action of the vehicle and information of a traffic environment around the vehicle, calculates one or more movement destination candidates, which may be selected by the vehicle for achieving the planned action, and sizes of spaces of the movement destination candidates based on the information of the planned action and the information of the traffic environment, calculates a decision difficulty that is a difficulty of the decision for determining any movement destination candidates as a movement destination from among the movement destination candidates based on the decision time allowance, the number of movement destination candidates and the sizes of the spaces of the movement destination candidates, and performs a predetermined driving support on the basis of the decision difficulty.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a driving assistance device, a driving assistance processing method, and a computer program. [Background technology]

[0002] During driving, the vehicle encounters various traffic situations. In addition, the driver of the vehicle encounters situations where he or she is forced to make a decision about his or her driving behavior under each traffic situation. For example, in a traffic situation where a side road merges into a main road on a highway or a trunk road, when there are multiple selectable merge spaces (destinations), the driver may be forced to decide which merge space to move the vehicle to. In such a situation, a driver with a low level of proficiency worries about which merge space to move the vehicle to, and becomes impatient as the end point of the merge approaches. In addition, when there is a vehicle following the vehicle, the driver feels that he or she is urged to make a decision about the merge space, and becomes even more impatient, as the driver tries to avoid causing a negative impact on the following vehicle.

[0003] In addition, in a traffic situation where a driver makes a right or left turn from a road where multiple oncoming vehicles exist so as to cross an oncoming lane, the driver may be forced to decide which passing space (destination) between oncoming vehicles the vehicle should pass through. In such a situation, a driver with low proficiency may be troubled by which passing space the vehicle should pass through, and may become impatient as time passes. In addition, if there is a vehicle following the vehicle, the driver may feel urged to decide on a passing space, and may become even more impatient, if he or she wants to avoid causing a negative impact on the following vehicle.

[0004] In response to this, Patent Document 1 proposes a driving assistance device that enables a driver to preferentially determine, among other vehicles present around the vehicle, a vehicle that the driver should pay the most attention to.Specifically, Patent Document 1 discloses a driving assistance device that determines the priority order of target vehicles that are targets of driving assistance according to the margin of time until the vehicle approaches the other vehicle and the type of driving assistance for the driver of the vehicle (right turn assistance, rear-end collision prevention assistance, left turn assistance, temporary stop assistance, emergency vehicle information, etc.).

[0005] Furthermore, Patent Document 2 discloses an information presentation device that is mounted on an autonomous vehicle capable of setting candidate actions for the vehicle based on the occupant's selection of presented selection information, sets candidate actions for the autonomous vehicle, calculates a selection margin from the current time to the time when the occupant should complete their selection of the selected information, selects selection information based on the candidate actions in accordance with the selection margin, and presents the set selection information to the occupant. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2010-108344 A [Patent Document 2] International Publication No. 2017 / 056224 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in addition to the above-mentioned margin time for judgment, the difficulty of the vehicle driver to judge which destination candidate is the best to select as the destination may change depending on the number of destination candidates and the size of each destination candidate. For example, it is considered that the greater the number of destination candidates, the smaller the space size of the destination candidates, and the smaller the difference in the size of each space, the greater the difficulty of the driver to decide the destination. In the technology disclosed in Patent Documents 1 and 2, the assisted vehicle or action candidate is determined taking into consideration the margin time until the time when the vehicle's action should be decided, but the number of destination candidates and the size of the space of each destination candidate are not taken into consideration. For this reason, there is a risk that the assistance provided by the driving assistance device or the information presentation device will not be appropriate assistance according to the situation.

[0008] The present disclosure has been made in consideration of the above problems, and an object of the present disclosure is to provide a driving assistance device, a driving assistance processing method, and a computer program that are capable of providing appropriate assistance according to the range of judgment of candidate destinations in situations where a judgment must be made about the driving behavior of the vehicle to be assisted. [Means for solving the problem]

[0009] In order to solve the above problem, according to an aspect of the present disclosure, a driving assistance device that assists in driving a vehicle is provided, comprising one or more processors and one or more memories communicatively connected to the one or more processors, wherein the one or more processors execute a margin time calculation process that calculates a decision margin time, which is a time until the vehicle starts the planned action, based on information on the planned action of the vehicle and information on the traffic environment around the vehicle; a space detection process that determines one or more destination candidates that the vehicle may select to achieve the planned action and the space size of each of the destination candidates, based on the information on the planned action and the information on the traffic environment; a difficulty calculation process that calculates a judgment difficulty level, which is the difficulty of a judgment to determine one of the destination candidates as a destination, based on the decision margin time, the number of the destination candidates, and the space size of the destination candidates; and an assistance process that performs a predetermined driving assistance based on the judgment difficulty level.

[0010] In addition, in order to solve the above problem, according to another aspect of the present disclosure, there is provided a driving assistance processing method for assisting driving of a vehicle, in which a computer executes the following steps: calculates a decision margin, which is a time until the vehicle starts the planned action, based on information on the planned action of the vehicle and information on the traffic environment around the vehicle; determines one or more candidate destinations that the vehicle can select to achieve the planned action, and the space size of each of the candidate destinations, based on the information on the planned action and the information on the traffic environment; calculates a decision difficulty, which is the difficulty of a decision to determine one of the candidate destinations as a destination, based on the decision margin, the number of the candidate destinations, and the space size of the candidate destinations; and provides predetermined driving assistance based on the decision difficulty.

[0011] In addition, in order to solve the above problem, according to another aspect of the present disclosure, there is provided a computer program that causes a computer to function as a driving assistance device that performs the following operations: calculate a decision margin, which is the time until the vehicle starts the planned action, based on information on the planned action of the vehicle and information on the traffic environment around the vehicle; determine one or more candidate destinations that the vehicle can select to achieve the planned action and the space size of each of the candidate destinations, based on the information on the planned action and the information on the traffic environment; calculate a decision difficulty, which is the difficulty of a decision to determine one of the candidate destinations as a destination, based on the decision margin, the number of the candidate destinations, and the space size of the candidate destinations; and provide a predetermined driving assistance based on the decision difficulty. Effect of the Invention

[0012] As described above, according to the present disclosure, in a situation where a decision must be made regarding the driving behavior of a vehicle to be assisted, appropriate assistance can be provided according to the degree of decision regarding candidate destinations. [Brief description of the drawings]

[0013] [Figure 1] 1 is an explanatory diagram showing an overview of a driving assistance device according to a first embodiment of the present disclosure; [Diagram 2] 1 is an explanatory diagram showing an overview of a driving assistance device according to the embodiment; [Diagram 3] 2 is a schematic diagram showing a configuration example of a vehicle to which the driving assistance system of the embodiment can be applied. FIG. [Figure 4] 2 is a block diagram showing a configuration example of the driving assistance device according to the embodiment; FIG. [Diagram 5] 4 is a flowchart showing a main routine of a processing operation performed by the driving assistance device according to the embodiment; [Figure 6] 5 is a flowchart showing a decision margin time calculation process performed by the driving assistance device according to the embodiment; [Figure 7]5 is a flowchart showing a space detection process performed by the driving assistance device according to the embodiment. [Figure 8] 4 is a flowchart showing an assistance process performed by the driving assistance device according to the embodiment. [Figure 9] FIG. 4 is an explanatory diagram showing an overview of a driving assistance device according to a second embodiment of the present disclosure. [Figure 10] 2 is a block diagram showing a configuration example of the driving assistance device according to the embodiment; FIG. [Figure 11] 5 is a flowchart showing a decision margin time calculation process performed by the driving assistance device according to the embodiment; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In this specification and the drawings, components having substantially the same functional configurations are denoted by the same reference numerals, and redundant description will be omitted.

[0015] In the embodiment described below, the term "specific driving scene" refers to a driving scene defined in advance as a traffic situation in which the driver of the vehicle is forced to take a planned action involving a driving behavior decision. Also, the term "traffic participants" refers to other vehicles and pedestrians around the vehicle to be assisted in the specific driving scene.

[0016] Furthermore, the "destination candidate" and "destination" are target positions to which the vehicle to be assisted is moved, and are not limited to absolute positions specified on the road, but indicate positions in front of or behind a specified other vehicle, or a position between two specified other vehicles. Furthermore, moving the vehicle to be assisted is not limited to completing the movement to the "destination candidate" or "destination", but also includes passing through the "destination candidate" or "destination".

[0017] <<1. First embodiment>> <1-1. Overview> First, an outline of a driving support device according to a first embodiment will be described. In the first embodiment, an example of a driving support device that can be applied to a specific driving scene in which a vehicle to be supported merges into or changes lanes into a lane in which multiple other vehicles are traveling as a scheduled action of the vehicle will be described.

[0018] 1 shows a merging scene in which an assisted vehicle 1 merges from a travel lane 73 in which it is traveling onto a main lane 71. Seven other vehicles 101a-101g are present on the main lane 71. In addition, a following vehicle 103 traveling on the same travel lane 73 is present behind the vehicle 1. In the merging scene, if there is a clearly wide space (vehicle distance) between the other vehicles 101a-101g traveling on the main lane 71 at the merging destination at the right time, the driver of the vehicle 1 can merge onto the main lane 71 without hesitation.

[0019] On the other hand, in a merging scene, if there are multiple spaces that are movable but not large enough, the driver of vehicle 1 may be unsure of when and to which space to move to. In such a situation, as vehicle 1 gradually approaches merging end point 75, the driver becomes impatient. Moreover, the more the driver thinks about not causing a negative impact on the following vehicle 103, the more he feels the urgency of deciding where to move, and the more impatient he becomes.

[0020] FIG. 2 shows a driving scene in which the driving lane 83 in which the vehicle 1 to be assisted is traveling becomes a right-turn-only lane, and the vehicle 1 merges (changes lanes) into an adjacent lane 81 in which the vehicle 1 can go straight. Five other vehicles 101a to 101e exist in the adjacent lane 81. In addition, in front of and behind the vehicle 1, there are forward vehicles 105a to 105b and a following vehicle 103, respectively, traveling in the same driving lane 83. The boundary between the driving lane 83 and the adjacent lane 81 allows lane changes up to an intersection, but prohibits lane changes near the intersection. In a driving scene in which the vehicle 1 merges from the driving lane 83 to the adjacent lane 81, if there is a clearly wide space (inter-vehicle distance) between the other vehicles 101a to 101e traveling in the adjacent lane 81 at the right time, the driver of the vehicle 1 can change lanes to the adjacent lane 81 without hesitation.

[0021] On the other hand, in a merging scene, if there are multiple spaces that are movable but not large enough, the driver of the vehicle 1 may be unsure of when and to which space to move to. In such a situation, when the vehicle 1 gradually approaches the lane change prohibited area 85, the driver becomes impatient. Moreover, the more the driver thinks about not causing a negative impact on the following vehicle 103, the more he feels the urgency of deciding where to move, and the more impatient he becomes.

[0022] In a merging scene as shown in Figures 1 and 2, when there are multiple destination candidates MS, the size of the space of each destination candidate MS is small, and the difference in the size of each space is small, the difficulty of determining the destination increases. In addition, the shorter the decision margin time, the higher the difficulty of the decision. As a result, the driver may try to forcibly merge into the main lane 71 or the adjacent lane 81 after running out of margin, which may endanger not only the driver's own vehicle but also surrounding traffic participants.

[0023] In consideration of such a situation, the driving assistance device according to the present embodiment determines whether to assist the driver in driving, or the content of the driving assistance, depending on the difficulty of judgment when executing the driving action of merging or changing lanes. This allows the driving assistance device to provide appropriate assistance when the driver acts in a hurry in a situation where it becomes difficult for the driver to safely merge through his / her own driving operation. Note that the "difficulty of judgment (judgment difficulty)" does not indicate the difficulty of moving the vehicle, but the difficulty of judgment to determine the destination.

[0024] <1-2. Overall configuration of a vehicle equipped with a driving assistance device> First, an example of the overall configuration of a vehicle equipped with a driving assistance device according to this embodiment will be described.

[0025] FIG. 3 is an explanatory diagram showing an example of the configuration of a vehicle 1 equipped with a driving support device 50. As shown in FIG. The vehicle 1 is configured as a two-wheel drive four-wheel vehicle in which driving torque output from a driving force source 9 that generates driving torque is transmitted to a left front wheel and a right front wheel. The vehicle 1 may be a four-wheel drive vehicle that transmits driving torque to front wheels and rear wheels. The driving force source 9 may be an internal combustion engine such as a gasoline engine or a diesel engine, or may be a driving motor. The vehicle 1 may also be a hybrid electric vehicle in which the driving force source 9 is an internal combustion engine and a driving motor.

[0026] The vehicle 1 may be an electric vehicle equipped with two drive motors, for example a front-wheel drive motor and a rear-wheel drive motor, or an electric vehicle equipped with drive motors corresponding to the respective wheels. If the vehicle 1 is an electric vehicle or a hybrid electric vehicle, the vehicle 1 is equipped with a secondary battery that stores the power supplied to the drive motors, and a generator such as a motor or fuel cell that generates power to charge the battery.

[0027] The vehicle 1 is equipped with a driving force source 9, an electric steering device 15, and brake devices 17LF, 17RF, 17LR, 17RR (hereinafter collectively referred to as "brake devices 17" unless a distinction is required) as devices used to control the operation of the vehicle 1. The driving force source 9 outputs a driving torque that is transmitted to the front wheel drive shaft 5F via a transmission and a differential mechanism 7 (not shown). The operation of the driving force source 9 and the transmission is controlled by a vehicle control device 41 equipped with one or more electronic control devices (ECU: Electronic Control Unit).

[0028] The front-wheel drive shaft 5F is provided with an electric steering device 15. The electric steering device 15 includes an electric motor and a gear mechanism (not shown), and adjusts the steering angle of the front wheels by being controlled by a vehicle control device 41. During manual driving, the vehicle control device 41 controls the electric steering device 15 based on the steering angle of the steering wheel 13 by the driver. During automatic driving, the vehicle control device 41 controls the electric steering device 15 based on the steering angle or steering angular speed that is set.

[0029] Brake devices 17LF, 17RF, 17LR, and 17RR apply braking force to each wheel. Brake devices 17 are configured as hydraulic brake devices, for example. Vehicle control device 41 adjusts the hydraulic pressure supplied to each brake device 17 by controlling the driving of hydraulic unit 16. When vehicle 1 is an electric vehicle or a hybrid electric vehicle, brake devices 17 are used in combination with regenerative braking by a drive motor.

[0030] The vehicle control device 41 includes one or more electronic control devices that control the driving of the driving force source 9, the electric steering device 15, and the hydraulic unit 16. In the case where the vehicle 1 is equipped with a transmission that changes the speed of the output output from the driving force source 9 and transmits it to the wheels 3, the vehicle control device 41 has a function of controlling the driving of the transmission.

[0031] The vehicle 1 also includes front photographing cameras 31LF, 31RF, a rear photographing camera 31R, a vehicle state sensor 33, a position detection sensor 35, an inter-vehicle communication device 37, and a notification device 43.

[0032] The front photographing cameras 31LF, 31RF and the rear photographing camera 31R are one aspect of a surrounding environment sensor for acquiring information on the surrounding environment of the vehicle 1. The front photographing cameras 31LF, 31RF capture images of the front of the vehicle 1 and generate image data. The rear photographing camera 31R captures images of the rear of the vehicle 1 and generates image data. The front photographing cameras 31LF, 31RF and the rear photographing camera 31R are equipped with imaging elements such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS), and transmit the generated image data to the driving assistance device 50. In the vehicle 1 shown in FIG. 3, the front photographing cameras 31LF, 31RF are configured as stereo cameras including a pair of left and right cameras, but the front photographing cameras may be monocular cameras.

[0033] The surrounding environment sensor may include, for example, a camera provided on a side mirror for capturing images of the left rear or right rear, in addition to the front photographing cameras 31LF, 31RF and the rear photographing camera 31R. The surrounding environment sensor may include one or more sensors selected from the group consisting of a LiDAR (Light Detection And Ranging) sensor, a radar sensor such as a millimeter wave radar, and an ultrasonic sensor.

[0034] The vehicle state sensor 33 is composed of at least one sensor that detects the operation state and behavior of the vehicle 1. The vehicle state sensor 33 includes at least one of a steering angle sensor, an accelerator position sensor, a brake stroke sensor, a brake pressure sensor, and an engine speed sensor, for example. The vehicle state sensor 33 also includes at least one of a vehicle speed sensor, an acceleration sensor, and an angular velocity sensor, for example. The vehicle state sensor 33 further includes a switch that detects the on / off state of a turn signal. The vehicle state sensor 33 transmits a sensor signal indicating the detected information to the driving assistance device 50.

[0035] The position detection sensor 35 receives satellite signals from positioning satellites of a Global Navigation Satellite System (GNSS) such as a Global Positioning System (GPS). The position detection sensor 35 transmits position information of the vehicle 1 contained in the received satellite signals to the driving assistance device 50. Note that the position detection sensor 35 may be an antenna that receives satellite signals from other satellite systems that identify the position of the vehicle 1, in addition to a GPS sensor.

[0036] The vehicle-to-vehicle communication device 37 is an interface for communicating with other vehicles that are present within a predetermined range from the vehicle 1. The vehicle-to-vehicle communication device 37 communicates with other vehicles that are also equipped with vehicle-to-vehicle communication devices, and acquires information on the surrounding environment detected by the other vehicles and information on the operation state and behavior of the other vehicles.

[0037] The notification device 43 is driven by the driving assistance device 50, and notifies the driver of the vehicle 1 of various information by means of image display, audio output, etc. The notification device 43 includes, for example, a display device provided in an instrument panel and a speaker provided in the vehicle 1. The display device may be a display device of a navigation system. The notification device 43 may also be a HUD (head-up display) that displays information on the front window.

[0038] (1-2. Composition) Next, a configuration example of the driving support device 50 will be described. The driving assistance device 50 functions as a device that assists in driving a vehicle by executing a computer program by a processor such as one or more CPUs (Central Processing Units). The computer program is a computer program for causing the processor to execute operations to be performed by the driving assistance device 50, which will be described later. The computer program executed by the processor may be recorded on a recording medium that functions as a storage unit (memory) 55 provided in the driving assistance device 50, or may be recorded on a recording medium built into the driving assistance device 50 or any recording medium that can be externally attached to the driving assistance device 50.

[0039] Examples of recording media for recording computer programs include magnetic media such as hard disks, floppy disks, and magnetic tapes; optical recording media such as CD-ROMs (Compact Disk Read Only Memory), DVDs (Digital Versatile Disks), and Blu-ray (registered trademark); magneto-optical media such as floptical disks; memory elements such as RAMs and ROMs; and flash memories such as USB (Universal Serial Bus) memories and SSDs, as well as other media capable of storing programs.

[0040] FIG. 3 is an explanatory diagram showing the configuration of the driving support device 50 in the form of functional blocks. The driving support device 50 is connected to an ambient environment sensor 31, a vehicle state sensor 33, a position detection sensor 35, and an inter-vehicle communication device 37 via a dedicated line or communication means such as a controller area network (CAN) or a local inter net (LIN). In addition, a vehicle control device 41 and a notification device 43 are communicatively connected to the driving support device 50.

[0041] The driving assistance device 50 is not limited to an electronic control device mounted on the vehicle 1, and may be a terminal device such as a smartphone or a wearable device.

[0042] The driving assistance device 50 includes a processing unit 51 and a memory unit 53 . The processing unit 51 is configured to include one or more processors such as CPUs. A part or all of the processing unit 51 may be configured with updatable firmware or the like, or may be a program module or the like executed by instructions from the CPU or the like.

[0043] The storage unit 53 is composed of one or more memories such as RAM or ROM, and is communicatively connected to the processing unit 51. However, the number and type of the storage units 53 are not particularly limited. The storage unit 53 stores information such as computer programs executed by the processing unit 51, various parameters used in arithmetic processing, detection data, and arithmetic results. Map data is also stored in the storage unit 53. A part of the storage unit 53 is used as a work area for the processing unit 51.

[0044] The processing unit 51 includes an acquisition unit 61, a surrounding environment detection unit 62, a driving scene determination unit 63, a margin time calculation unit 64, a space detection unit 65, a difficulty level calculation unit 66, and an assistance processing unit 67. The functions of these units are realized by the execution of a computer program by a processor. Note that some of the acquisition unit 61, the surrounding environment detection unit 62, the driving scene determination unit 63, the margin time calculation unit 64, the space detection unit 65, the difficulty level calculation unit 66, and the assistance processing unit 67 may be configured by hardware such as an analog circuit.

[0045] (Acquisition Department) The acquisition unit 61 acquires the sensor signals or detection result information output from the surrounding environment sensor 31, the vehicle state sensor 33, and the position detection sensor 35 at each predetermined processing cycle.

[0046] (Ambient environment detection section) The surrounding environment detection unit 62 detects the traffic environment around the vehicle 1 based on the sensor signal or the information of the detection result output from the surrounding environment sensor 31. For example, the surrounding environment detection unit 62 extracts feature points from the image data generated by the front photographing cameras 31LF, 31RF and the rear photographing camera 31R, and recognizes the object by matching the pattern of the feature points with reference data prepared in advance. The surrounding environment detection unit 62 recognizes various objects such as moving objects such as people, bicycles, motorcycles, and four-wheeled automobiles, as well as man-made or natural stationary objects, and lines drawn on the road such as white lines and pedestrian crossings. The surrounding environment detection unit 62 also calculates the position and speed of the recognized object, as well as the distance to the object. The surrounding environment sensor 31 may execute a process of recognizing these moving objects and stationary objects. In this case, the driving assistance device 50 acquires information including these recognition results from the surrounding environment sensor 31.

[0047] Furthermore, the surrounding environment detection unit 62 detects information about the road on which the vehicle 1 is traveling, based on the map data and the position information of the vehicle 1. Furthermore, the surrounding environment detection unit 62 acquires information about the surroundings of the vehicle 1, based on information acquired from other vehicles via the vehicle-to-vehicle communication device 37. The surrounding environment detection unit 62 maps the various pieces of detected or acquired information, and generates mapping data of the traffic environment around the vehicle 1.

[0048] (Driving scene determination section) The driving scene determination unit 63 determines whether the vehicle 1 passes through a specific driving scene set in advance based on information on the traffic environment around the vehicle 1. Specifically, the driving scene determination unit 63 compares the road structure in the traffic environment around the vehicle 1 detected by the surrounding environment detection unit 62 and the traffic situation indicating the positional relationship of traffic participants around the vehicle 1 with the situation set as the specific driving scene, and determines that the vehicle 1 passes through the specific driving scene when the road structure and traffic situation correspond to the specific driving scene. The road structure is information about the road, such as the number of lanes (lanes) of the road, merging situation, intersection situation, curvature radius, road width or lane width, road type (general road, intercity expressway, urban expressway, residential road or shopping street, etc.), and type of road or lane boundary line.

[0049] In this embodiment, the driving scene determination unit 63 determines whether the vehicle 1 passes through a driving scene in which merging or lane changing is performed as a scheduled action of the vehicle 1 and in which the driver's decision timing is limited. The "specific driving scene" may be defined in advance at the system design stage, or may be arbitrarily defined by the user of the vehicle.

[0050] (Margin time calculation section) The margin time calculation unit 64 calculates a decision margin time, which is the time until the vehicle 1 starts the scheduled action, based on information on the scheduled action of the vehicle 1 and information on the traffic environment around the vehicle 1. In this embodiment, the scheduled action of the vehicle 1 is merging or lane changing, and the margin time calculation unit 64 calculates a decision margin time until the vehicle 1 starts the operation of merging or changing lanes. The margin time calculation unit 64 calculates a first margin time until the vehicle 1 reaches a limit position where it should start the scheduled action, and a second margin time at which the vehicle 1 is forced to make a decision due to the approach of a following vehicle.

[0051] In the example of the merging scene shown in FIG. 1, the merging end point 75 corresponds to the limit position where the planned action should be started. The margin time calculation unit 64 calculates the first margin time based on the vehicle speed of the vehicle 1 and the distance from the vehicle 1 to the merging end point 75. The margin time calculation unit 64 may calculate the first margin time by further considering the estimated deceleration of the vehicle 1. Furthermore, the margin time calculation unit 64 calculates the second margin time based on the relative speed between the vehicle 1 and the following vehicle 103 and the inter-vehicle distance between the vehicle 1 and the following vehicle 103. The margin time calculation unit 64 may calculate the second margin time by further considering the estimated deceleration of the vehicle 1 and the following vehicle 103.

[0052] In the example of the merging scene shown in FIG. 2, the lane change prohibited area 85 corresponds to the limit position where the scheduled action should be started. The margin time calculation unit 64 calculates the first margin time based on the vehicle speed of the vehicle 1 and the distance from the vehicle 1 to the lane change prohibited area 85. The margin time calculation unit 64 may calculate the first margin time by further considering the estimated deceleration of the vehicle 1. Furthermore, the margin time calculation unit 64 calculates the second margin time based on the relative speed between the vehicle 1 and the following vehicle 103 and the inter-vehicle distance between the vehicle 1 and the following vehicle 103. The margin time calculation unit 64 may calculate the second margin time by further considering the estimated deceleration of the vehicle 1 and the following vehicle 103.

[0053] (Space detection section) The space detection unit 65 determines one or more candidate destinations that the vehicle 1 may select to achieve the scheduled action, and the size of the space of each of the candidate destinations, based on information on the scheduled action of the vehicle 1 and information on the traffic environment around the vehicle 1. In this embodiment, the scheduled action of the vehicle 1 is merging or changing lanes, and the space detection unit 65 calculates the candidate destinations for the vehicle 1 to merge or change lanes, and the size of the space of each of the candidate destinations (the distance between other vehicles).

[0054] The space detection unit 65 searches for destination candidates within a range from a position at a predetermined first distance forward in the traveling direction of the vehicle 1 to a position at a predetermined second distance backward in the traveling direction of the vehicle 1. The first distance and the second distance are values ​​set to limit the range in which the vehicle 1 can move, and may be fixed values ​​or values ​​that change according to the speed of the vehicle 1. However, when the distance from the vehicle 1 to the limit position where the scheduled action should be started becomes smaller than the first distance, the space detection unit 65 searches for destination candidates within a range from the limit position to a position at the second distance.

[0055] 1 and 2, the space detection unit 65 calculates the inter-vehicle distance between the other vehicles 101a-101g traveling on the main lane 71 at the merging destination or the adjacent lane 81 at the lane change destination, and sets a space where the inter-vehicle distance is equal to or greater than a preset threshold as a candidate destination MS. The inter-vehicle distance threshold may be a fixed value, or may be a value that changes depending on the speed or relative speed of the vehicle 1 and the other vehicles 101a-101g.

[0056] Furthermore, the space detection unit 65 calculates the time required for the vehicle 1 to complete movement to each of the set destination candidate MS. The space detection unit 65 calculates the time required for the vehicle 1 to complete movement to each of the destination candidate MS based on the distance from the vehicle 1 to the space of the destination candidate MS and the change in the distance over time.

[0057] (Difficulty Calculation Section) The difficulty calculation unit 66 calculates the judgment difficulty, which is the difficulty of making a judgment to determine one of the destination candidates as a destination, based on the judgment margin time, the number of destination candidates, and the size of the space of the destination candidate. The difficulty calculation unit 66 calculates the judgment difficulty so that the judgment difficulty becomes higher as the judgment margin time is shorter, the number of destination candidates is greater, or the size of the space of the destination candidate is smaller and the difference in size between the spaces is smaller. In this embodiment, the difficulty calculation unit 66 calculates the judgment difficulty using a predetermined formula.

[0058] (Support Processing Unit) The support processor 67 performs a predetermined driving support based on the judgment difficulty. In this embodiment, the support processor 67 sets the content of the driving support to be performed according to the case where the judgment difficulty is equal to or higher than a predetermined first standard, the case where the judgment difficulty is lower than the predetermined first standard and equal to or higher than a predetermined second standard, the case where the judgment difficulty is lower than the predetermined second standard and equal to or higher than a predetermined third standard, and the case where the judgment difficulty is lower than the predetermined third standard.

[0059] Specifically, when the degree of difficulty of judgment is equal to or greater than a predetermined first standard, the support processing unit 67 executes a process of determining, as a destination, any one of the destination candidates for which the time required to complete movement to the destination candidate is equal to or less than a predetermined standard, and automatically moving the vehicle 1. In addition, when the degree of difficulty of judgment is less than the predetermined first standard and equal to or greater than a predetermined second standard, the support processing unit 67 executes a process of notifying the driver of the vehicle 1 of any one of the destination candidates for which the time required to complete movement to the destination candidate is equal to or less than a predetermined standard.

[0060] In addition, when the judgment difficulty is less than a predetermined second standard and equal to or greater than a predetermined third standard, the assistance processing unit 67 sets the content to be notified depending on the factors that have a large influence on the judgment difficulty among the judgment margin time, the number of candidate destinations, and the space size of the candidate destinations, and executes a process of notifying the driver of the vehicle 1 of the set content.

[0061] (1-3. Processing Operation) Next, the processing operation of the driving support device 50 will be specifically described.

[0062] 4 to 7 are flowcharts showing the processing operation by the driving support device 50. FIG.

[0063] When the in-vehicle system including the driving assistance device 50 is started (step S11), the surrounding environment detection unit 62 of the processing unit 51 detects the traffic environment around the vehicle 1 (step S13). Specifically, the surrounding environment detection unit 62 detects the traffic environment around the vehicle 1 based on the sensor signal or detection result information transmitted from the surrounding environment sensor 31, the position information of the vehicle 1 transmitted from the position detection sensor 35 and information on the road structure specified by the map data, and information on other vehicles and the surrounding environments of other vehicles acquired from other vehicles via the vehicle-to-vehicle communication device 37.

[0064] Next, the driving scene determination unit 63 of the processing unit 51 determines whether the vehicle 1 passes through a specific driving scene (step S15). Specifically, the driving scene determination unit 63 compares the road structure in the traffic environment around the vehicle 1 detected by the surrounding environment detection unit 62 and the traffic situation indicating the positional relationship of traffic participants around the vehicle 1 with the situation set as the specific driving scene, and determines that the vehicle 1 passes through the specific driving scene when the road structure and the traffic situation correspond to the specific driving scene.

[0065] For example, the driving scene determination unit 63 may determine that the vehicle 1 passes through a specific driving scene when it detects a road structure and traffic conditions corresponding to the specific driving scene, or may determine that the vehicle 1 passes through a specific driving scene when the vehicle 1 approaches the corresponding road structure and traffic conditions within a certain distance. The certain distance may be a constant value set to, for example, 30 to 50 m, or may be a value that changes depending on the speed of the vehicle 1.

[0066] In the case of the merging scene shown in Fig. 1, the driving scene determination unit 63 determines, for example, whether the vehicle 1 is traveling on a driving lane (side road) 73 toward a merging point and whether the distance to a merging end point 75 is within a predetermined threshold. The driving scene determination unit 63 also determines whether the blinker switch of the vehicle 1 is indicating left, or whether the vehicle 1 is scheduled to merge onto a main road 71 based on a planned traveling route set in a navigation system (not shown). When both of the above determinations are positive, the driving scene determination unit 63 determines that the vehicle 1 will pass through the merging scene shown in Fig. 1.

[0067] In the case of the merging scene shown in Fig. 2, the driving scene determination unit 63 determines whether the vehicle 1 is driving toward an intersection in a right-turn-only driving lane 73 of a two-lane road, and whether a lane change prohibition area is 30 m before the intersection. The driving scene determination unit 63 also determines whether the turn signal switch of the vehicle 1 is indicating left, or whether the vehicle 1 is planning to go straight through the intersection based on a planned driving route set in a navigation system (not shown). If both of the above determinations are positive, the driving scene determination unit 63 determines that the vehicle 1 will pass through the merging scene shown in Fig. 2.

[0068] When the driving scene determination unit 63 does not determine that the vehicle 1 passes through the specific driving scene (S15 / No), the process returns to step S13. On the other hand, when the driving scene determination unit 63 determines that the vehicle 1 passes through the specific driving scene (S15 / Yes), the margin time calculation unit 64 of the processing unit 51 executes a process of calculating a decision margin time (step S17).

[0069] FIG. 5 shows a flowchart of a process for calculating the decision margin time. First, the surrounding environment detection unit 62 detects the traffic environment around the vehicle 1 in the same manner as in step S13 (step S31). Next, the margin time calculation unit 64 calculates the distance L limit In the example of the merging scene shown in Fig. 1, the merging end point 75 corresponds to the limit position. In the example of the merging scene shown in Fig. 2, the no lane change area 85 corresponds to the limit position.

[0070] Next, the margin time calculation unit 64 calculates a first margin time T limit (Step S35). The margin time calculation unit 64 calculates the distance L limit and the speed of vehicle 1, V ego Using the information, the first margin time T limit Calculate. T limit =L limit / V ego …(1)

[0071] When the vehicle 1 is decelerating, the margin time calculation unit 64 calculates the first margin time T limit may be calculated.

[0072] Next, the margin time calculation unit 64 calculates the inter-vehicle distance L between the vehicle 1 and the following vehicle 103 based on the detected traffic environment information. follow and relative velocity (V follow -V ego The relative speed is calculated by calculating the speed V follow Vehicle 1's speed V ego It can be found by subtracting

[0073] Next, the margin time calculation unit 64 calculates a second margin time T urgency (Step S39). The margin time calculation unit 64 calculates the inter-vehicle distance L between the vehicle 1 and the following vehicle 103 acquired in step S37. follow and relative velocity (V follow -V ego ) is used to calculate the second margin time T urgency Calculate. T urgency =L follow / (V follow -V ego ) …(2)

[0074] In addition, when the following vehicle 103 catches up with the vehicle 1 and continues to follow the vehicle 1 at a constant distance, the second margin time T urgency is set to zero. The vehicle distance L0 at which it is determined that the following vehicle 103 has caught up with the vehicle 1 may be set to an arbitrary value in advance. In addition, when the following vehicle 103 is not detected or the speed V of the following vehicle 103 is follow is the speed of vehicle 1, V ego If the second margin time T urgencyLet be ∞.

[0075] Returning to Fig. 4, following step S17, the space detection unit 65 executes a process of detecting a space of a candidate destination (step S19). The candidate destination is defined based on the traffic environment around the vehicle 1. For example, the candidate destination is defined as a space that exists on the lane where the vehicle 1 will merge (change lanes) and exists within a range from a position at a predetermined first distance ahead of the vehicle 1 in the traveling direction to a position at a predetermined second distance behind the vehicle 1 in the traveling direction, and is accessible to the vehicle 1.

[0076] FIG. 6 shows a flowchart of a process for detecting a space as a destination candidate. First, the surrounding environment detection unit 62 detects the traffic environment around the vehicle 1 (step S41) in the same manner as in step S13. Next, the space detection unit 65 calculates the size of the space (inter-vehicle distance) between the other vehicles traveling in the lane to which the vehicle will merge (lane change destination) (step S43).

[0077] To explain this in detail with reference to FIG. 1 or FIG. 2, the space detection unit 65 detects another vehicle P P that is present on the main lane 71 or adjacent lane 81 at the merging point within a range from a position at a predetermined first distance ahead of the vehicle 1 in the traveling direction to a position at a predetermined second distance behind the vehicle 1 in the traveling direction. i (i=1 to N, N is the total number of other vehicles, with the vehicle furthest in the traveling direction of vehicle 1 being 1, and sequentially numbering 2, 3, ... behind in the traveling direction). At this time, if the first distance exceeds the distance from vehicle 1 to the limit position (merging end point 75, no lane change area 85), the range ahead in the traveling direction of vehicle 1 is limited to the range up to the limit position. Also, if the second distance exceeds the inter-vehicle distance between vehicle 1 and the following vehicle 103, the range behind vehicle 1 in the traveling direction is limited to the range up to the following vehicle 103.

[0078] In addition, the space detection unit 65 detects the positions of the other vehicles P with respect to the vehicle 1 on a two-dimensional coordinate system in which the position of the vehicle 1 is set as the origin coordinate and the traveling direction of the vehicle 1 is set as the positive coordinate. i Relative position L ego-piThe size of the space between the other vehicles 101 (vehicle distance) D is calculated using the following formula (3). pi Calculate L ego-pi There is another vehicle P i indicates the relative position of L ego-pi+1 is other vehicle P i The following vehicle P i+1 indicates the relative position of L veh is other vehicle P i Or P i+1 The assumed total length of L veh may be an arbitrary fixed value, may be the total length of the vehicle 1, or may be a value measured by the surrounding environment sensor 31. D pi =L ego-pi+1 -L ego-pi -L veh …(3)

[0079] Next, the space detection unit 65 calculates the size (inter-vehicle distance) D pi All spaces whose length is equal to or larger than a predetermined threshold are set as candidate destinations (step S45). ego to a given correction value L repletion is added to the given correction value L repletion is set to an arbitrary value. The predetermined correction value L repletion may be a value that changes depending on the speed of the vehicle 1 or the other vehicle. Therefore, the space detection unit 65 sets all spaces that satisfy the condition of the following formula (4) as candidate spaces for the destination. D pi ≧L ego +L repletion …(4)

[0080] Furthermore, the space detection unit 65 calculates the travel time T dpi (Step S47). The travel time T dpi is, for example, another vehicle P located in front of or behind the destination candidate. i Relative position L ego-pi and the speed of vehicle 1, V egoThe space detection unit 65 calculates the travel time T dpi may be calculated. T dpi =L ego-pi / V ego …(5)

[0081] The space detection unit 65 calculates the travel time T dpi is recorded, and the destination candidate detection process is terminated.

[0082] Returning to FIG. 4, after step S19, the difficulty level calculation unit 66 calculates the decision margin time T dic (First margin time T limit and the second margin time T urgency whichever is smaller), the number of destination candidates N dpi , and the size of the destination space candidate D pi Based on the above, a judgment difficulty Diff is calculated, which is the difficulty of a judgment for determining one of the destination candidates as a destination (step S21). In this embodiment, the difficulty calculation unit 66 calculates the judgment difficulty Diff by the following formula (6).

[0083]

number

[0084] The decision margin time T in the above formula (6) dic is the first margin time T limit and the second margin time T urgency The judgment difficulty Diff is calculated as a value in the range of 0 to 1, and the larger the judgment difficulty Diff, the more difficult it is for the driver to make a judgment. The judgment difficulty Diff is calculated based on the judgment margin time T dic The shorter the number of destination candidates N dpi The more the number of candidates, or the smaller the size of the destination space, and the difference in size between the spaces, ΔD pi (=D pi -D pi-1The smaller the T in the above formula (6), the larger the value. α , N β , D γ , ΔD δ is a constant that is preset to an arbitrary value.

[0085] The method of calculating the judgment difficulty Diff is not limited to the above example. For example, as shown in the following formula (7), limit and the second margin time T urgency The judgment difficulty Diff may be calculated so as to reflect both of the above.

[0086]

number

[0087] The two T in the above formula (7) α may be the same value or may be different values.

[0088] Or, the decision margin time T dic , the number of destination candidates N dpi , and the size of the destination space candidate D pi A threshold value may be set for each of the above, and the difficulty level calculation unit 66 may use the following formula (8) to output two values ​​(0 or 1) depending on whether each threshold is exceeded or fallen short, and represent the difficulty level as the average of the two values ​​output.

[0089]

number

[0090] The judgment difficulty Diff is calculated as a value in the range of 0 to 1, and the larger the judgment difficulty Diff, the more difficult the situation is for the driver to make a judgment. α , N β , D γ , ΔD δ indicates a preset threshold value. dic Instead, the first margin time T limit and the second margin time Turgency The judgment difficulty Diff may be calculated so as to reflect both of the above.

[0091] Next, the support processing unit 67 performs a predetermined driving support based on the determination difficulty Diff calculated by the difficulty calculation unit 66 (step S23). The determination difficulty Diff calculated by any of the above formulas (6) to (8) is calculated as a value within a range of 0 to 1, and the support processing unit 67 performs the predetermined driving support based on, for example, the following criteria.

[0092] (A) Diff<0.25 (corresponding to the third criterion): The assistance processing unit 67 does not execute driving assistance.

[0093] (B) 0.25 (corresponding to the third criterion)≦Diff<0.75 (corresponding to the first criterion): The support processor 67 notifies the driver of the vehicle 1 of any of the destination candidates whose travel time is equal to or less than a predetermined criterion. The destination candidate to be notified may be the destination candidate with the shortest travel time, but may also be the destination candidate with the second or third shortest travel time, taking other conditions into consideration. If the notification device 43 includes a HUD, the support processor 67 superimposes and displays the position of the merging end point 75 or the lane change prohibited area 85 on the front window.

[0094] (C) 0.75 (corresponding to the first criterion)≦Diff: The support processing unit 67 determines one of the destination candidates whose travel time is equal to or shorter than the predetermined criterion as the destination, and automatically moves the vehicle 1 to that destination. For example, the support processing unit 67 transmits information on the determined destination to the vehicle control device 41. As a result, the vehicle control device 41 automatically controls the acceleration / deceleration and steering angle of the vehicle 1, moves the vehicle 1 to the predetermined destination, and completes the merging or lane change.

[0095] When calculating the decision difficulty Diff by the above formula (8), the support processing unit 67 may further classify the content of the driving support to be executed. dic (T limit / T urgency ), the number of destination candidates N dpi, and the size of the destination space candidate D pi The notification content may be set according to the element that has a large influence on the judgment difficulty Diff among the above, and the set content may be notified to the driver of the vehicle 1.

[0096] (A) Diff<0.25 (corresponding to the third criterion): The assistance processing unit 67 does not execute driving assistance.

[0097] (B-1) 0.25 (corresponding to the third criterion)≦Diff<0.50 (corresponding to the second criterion): the assistance processing unit 67 executes one or more of the following driving assistance operations.

[0098] (i)F limit If YES, the support processing unit 67 causes the notification device 43 to display the distance (m) to the merging end point 75 or the lane change prohibited area 85. If the notification device 43 includes a HUD, the support processing unit 67 causes the position and distance (m) to the merging end point 75 or the lane change prohibited area 85 to be superimposed on the front window.

[0099] (ii)F urgency If , the support processing unit 67 calculates the distance L between the vehicle 1 and the following vehicle 103. follow is displayed on the notification device 43.

[0100] (iii)F Ndpi If =1, the support processing unit 67 causes the notification device 43 to display an overhead view centered on the vehicle 1, and highlights one or more destination candidates by coloring, shading, framing, or other methods.

[0101] (iv)F dpi If =1, the support processing unit 67 causes the notification device 43 to display an aerial view centered on the vehicle 1, highlighting one or more potential destinations by coloring, shading, framing, or other methods, and also displays the size of each potential destination numerically.

[0102] (B-2) 0.50 (corresponding to the second criterion)≦Diff<0.75 (corresponding to the first criterion): The support processor 67 notifies the driver of the vehicle 1 of any of the destination candidates whose travel time is equal to or shorter than a predetermined criterion. If the notification device 43 includes a HUD, the support processor 67 displays the position of the merging end point 75 or the lane change prohibited area 85 superimposed on the front window.

[0103] (C) 0.75 (corresponding to the first criterion)≦Diff: The support processing unit 67 determines one of the destination candidates whose travel time is equal to or shorter than the predetermined criterion as the destination, and automatically moves the vehicle 1 to that destination. For example, the support processing unit 67 transmits information on the determined destination to the vehicle control device 41. As a result, the vehicle control device 41 automatically controls the acceleration / deceleration and steering angle of the vehicle 1, moves the vehicle 1 to the predetermined destination, and completes the merging or lane change.

[0104] The above first criterion = 0.75, second criterion = 0.50, and third criterion = 0.25 are merely examples, and each may be set to an arbitrary value.

[0105] After the assistance process is executed, the processing unit 51 determines whether the in-vehicle system has stopped (step S25), and if it is determined that the in-vehicle system has not stopped (S25 / No), the processing unit 51 returns to step S13. On the other hand, if it is determined that the in-vehicle system has stopped (S25 / Yes), the processing unit 51 stops the processing operation.

[0106] <1-4.Effects> As described above, the driving assistance device 50 according to the first embodiment of the present disclosure calculates the decision margin time, which is the time until the vehicle 1 starts to take action to merge or change lanes, and obtains one or more candidate destinations that the vehicle 1 can select when merging or changing lanes, and the size of the space of each candidate destination. In addition, the driving assistance device 50 calculates a decision difficulty level based on the decision margin time, the number of candidate destinations, and the size of the space of the candidate destinations, and performs a predetermined driving assistance based on the decision difficulty level.

[0107] As a result, the provision of information or automatic control of the vehicle 1 is executed in stages according to the difficulty of the driver's judgment of the destination candidate, and appropriate driving assistance is executed. In other words, while assisting the driver in merging or changing lanes through his / her own driving operation, in a situation where the driver himself / herself is in a difficult position to handle and the driver may act in a panic, the merging or lane change can be safely completed through automatic control. Therefore, it is possible to suppress an increase in the frequency of forced intervention of automatic control by the driving assistance device 50, and to increase the safety of the vehicle 1 while increasing the driver's reliability of the driving assistance device 50.

[0108] In addition, the driving support device 50 according to the present embodiment increases the difficulty of judgment as the time to decision is shorter, the number of destination candidates is greater, or the size of the destination candidate spaces is smaller and the difference in size between the spaces is smaller. This allows appropriate driving support to be performed based on the difficulty level that takes into account the complexity of the driver's decision on the destination.

[0109] Furthermore, when the judgment difficulty is equal to or greater than a predetermined first standard (0.75), the driving support device 50 according to this embodiment executes a process of determining, as a destination, any of the destination candidates whose time it takes to complete movement to the destination candidate is equal to or less than a predetermined standard, and automatically moving the vehicle 1. As a result, while giving priority to the driving operation by the driver himself, in a situation where the driver himself has determined the destination and is no longer able to operate the driving of the vehicle 1, the vehicle 1 is automatically controlled, and the safety of the vehicle 1 can be improved.

[0110] Furthermore, when the judgment difficulty level is less than a predetermined first standard (0.75) and equal to or greater than a predetermined second standard (0.50), the driving support device 50 according to this embodiment executes a process of notifying the driver of the vehicle 1 of any of the destination candidates for which the time required to complete movement to the destination candidate is equal to or less than a predetermined standard. This allows the driver to recognize the destination candidate at which merging or lane changing can be completed in the shortest time, and to start driving operation promptly.

[0111] Furthermore, when the judgment difficulty is less than a predetermined second standard (0.50) and equal to or greater than a predetermined third standard (0.25), the driving support device 50 according to this embodiment executes a process of setting the content to be notified according to the element that has a large influence on the judgment difficulty among the judgment margin time, the number of destination candidates, and the space size of the destination candidates, and notifying the driver of the vehicle 1 of the set content. As a result, appropriate information according to the element that increases the difficulty of the driver's judgment of the destination is presented to the driver, and it is possible to appropriately support the merging or lane changing by the driver's own driving operation.

[0112] Moreover, the driving support device 50 according to this embodiment searches for destination candidates within a range from a position at a predetermined first distance forward in the traveling direction of the vehicle 1 to a position at a predetermined second distance backward in the traveling direction of the vehicle 1. This eliminates the range that cannot be used as a destination of the vehicle 1 from the search targets, thereby reducing the time and load of the calculation process.

[0113] <<2. Second embodiment>> Next, a second embodiment of the present disclosure will be described.

[0114] In the second embodiment, an example of a driving assistance device that can be applied to a specific driving scene in which a vehicle to be assisted traveling in the left lane of a one-lane road turns right at an intersection across an oncoming lane where multiple oncoming vehicles are traveling, as a planned behavior of the vehicle, is described.

[0115] 8 shows a right turn scene in which the assisted vehicle 1 turns right at an intersection from the left lane 91 of a one-lane road, straddling an oncoming lane 93 in which multiple oncoming vehicles 111a-111e are traveling. Five oncoming vehicles 111a-111e exist in the oncoming lane 93. In addition, three following vehicles 113a-113c are traveling in the left lane 91 behind the vehicle 1. In the right turn scene, if there is a clearly wide space (inter-vehicle distance) between the oncoming vehicles 111a-111e traveling in the oncoming lane 93 at the right time, the driver of the vehicle 1 can pass between the oncoming vehicles 111a-111e without hesitation and make a right turn straddling the oncoming lane 93.

[0116] On the other hand, in a right turn scene, if there are multiple spaces that are passable but not large enough, the driver of the vehicle 1 may be unsure of when and through which space to turn right. In such a situation, as the time approaches when the traffic light at the intersection turns red, the driver becomes impatient. Also, the greater the number of following vehicles 103a-10c, the more the driver feels pressured to decide where to pass (where to move), and the more impatient he becomes.

[0117] In a right turn scene as shown in Fig. 8, when there are multiple destination candidates MS, the size of the space of each of the destination candidates MS is small, and the difference in the size of each space is small, the difficulty of judging the passing position increases. In addition, the shorter the decision margin time, the higher the difficulty of the judgment. As a result, the driver may try to make a right turn forcibly after running out of margin, which may endanger not only the driver's own vehicle but also surrounding traffic participants.

[0118] In consideration of such a situation, the driving assistance device according to the present embodiment determines whether to assist the driver in driving or the content of the driving assistance depending on the difficulty of the judgment when performing the driving action of turning right. This allows the driving assistance device to provide appropriate assistance when the driver acts in a hurry in a situation where it becomes difficult to make a safe right turn by driving operation by himself.

[0119] The basic configuration of the driving support device according to this embodiment and the vehicle 1 equipped with the driving support device may be similar to that of the driving support device 50 and the vehicle 1 according to the first embodiment. Hereinafter, the configuration of the driving support device according to this embodiment that differs from the first embodiment will be described.

[0120] 9 is an explanatory diagram showing the configuration of a driving support device 50A according to this embodiment in functional blocks. The driving support device 50A according to this embodiment is communicatively connected to a road-to-vehicle communication device 39. The road-to-vehicle communication device 39 is an interface for communicating with a device or system that manages a traffic light 97, and the driving support device 50A is configured to be able to acquire information on the lighting color of the traffic light 97 and the timing at which the lighting color changes via the road-to-vehicle communication device 39.

[0121] The margin time calculation unit 64 of the driving assistance device 50A calculates, as a decision margin time until the vehicle 1 starts turning right, a first margin time from when the light color of the traffic light 97 turns yellow until it turns red, and a second margin time until a decision is forced due to the presence of a following vehicle 113 that blocks the vehicle's progress. The margin time calculation unit 64 sets the time until the light color of the traffic light 97, which is acquired via the road-to-vehicle communication device 39, turns red as the first margin time. The margin time calculation unit 64 also calculates the second margin time by replacing it with the number of stopped following vehicles 113.

[0122] The processing operation of the driving support device 50A according to this embodiment will be specifically described below with reference to the flowchart shown in Fig. 4. In the following description, the processing of each step is executed in the same manner as in the first embodiment unless otherwise specified.

[0123] When the in-vehicle system including the driving assistance device 50 is started (step S11), the surrounding environment detection unit 62 of the processing unit 51 detects the traffic environment around the vehicle 1 (step S13). Next, the driving scene determination unit 63 of the processing unit 51 determines whether the vehicle 1 passes through a specific driving scene (step S15).

[0124] In the case of the right turn scene shown in Fig. 8, for example, when the vehicle 1 is traveling on a one-lane road and turns right at an intersection, the traveling scene determination unit 63 determines whether the oncoming vehicle 111 traveling straight in the oncoming lane 93 is traveling smoothly and whether the road width is such that the following vehicle will be blocked if the host vehicle waits to turn right. The traveling scene determination unit 63 also determines whether the blinker switch of the vehicle 1 is indicating right and the illumination color of the traffic light 97 has changed from green to yellow. If all of the above determinations are positive, the traveling scene determination unit 63 determines that the vehicle 1 will pass through the right turn scene shown in Fig. 8.

[0125] When the driving scene determination unit 63 does not determine that the vehicle 1 passes through the specific driving scene (S15 / No), the process returns to step S13. On the other hand, when the driving scene determination unit 63 determines that the vehicle 1 passes through the specific driving scene (S15 / Yes), the margin time calculation unit 64 of the processing unit 51 calculates the judgment margin time (first margin time T limit and the second margin time T urgency ) is calculated (step S17).

[0126] FIG. 9 shows a flowchart of a process for calculating the decision margin time. First, the surrounding environment detection unit 62 detects the traffic environment around the vehicle 1 in the same manner as in step S13 (step S31). Next, the margin time calculation unit 64 acquires information on the time until the light color of the traffic light 97 changes to red via the road-to-vehicle communication device 39 (step S34). The margin time calculation unit 64 calculates the acquired time as a first margin time T limit Let us assume that.

[0127] Next, the margin time calculation unit 64 calculates the number N of the following vehicles 113 based on the detected traffic environment information. fi Next, the margin time calculation unit 64 acquires information on the number N of the following vehicles 103 that are stopped (step S37). fi The second margin time T in which the driver is forced to make a decision based on urgency For example, the margin time calculation unit 64 calculates the number N of the following vehicles 103 by the following formula (9) (step S39). fiThe second margin time T urgency In the formula (9), T0 is a reference time that is arbitrarily set, and t is a coefficient that is arbitrarily set. T urgency =T0-N fi ×t …(9)

[0128] 4, following step S17, the space detection unit 65 calculates the space of the destination candidate MS and the size of the space of each of the destination candidates MS (step S19). For example, the destination candidate is defined as a space that exists on the oncoming traffic lane 93 and exists within a range from a position at a predetermined first distance ahead in the traveling direction of the vehicle 1 to the position of the intersection, into which the vehicle 1 can enter.

[0129] Next, the difficulty level calculation unit 66 calculates the decision margin time T dic (First margin time T limit and the second margin time T urgency whichever is smaller), the number of destination candidates N dpi , and the size of the destination space candidate D pi Based on this, a determination difficulty Diff, which is the difficulty of determining whether or not one of the destination candidates is a destination (passing position), is calculated (step S21).

[0130] Next, the support processing unit 67 performs a predetermined driving support based on the judgment difficulty Diff calculated by the difficulty calculation unit 66 (step S23). In this embodiment, as in the first embodiment, the support processing unit 67 performs driving support such as not performing driving support, notifying the destination (passing position), or automatically controlling the right turn of the vehicle 1, depending on the judgment difficulty Diff.

[0131] After the assistance process is executed, the processing unit 51 determines whether the in-vehicle system has stopped (step S25), and if it is determined that the in-vehicle system has not stopped (S25 / No), the processing unit 51 returns to step S13. On the other hand, if it is determined that the in-vehicle system has stopped (S25 / Yes), the processing unit 51 stops the processing operation.

[0132] As described above, the driving assistance device 50A according to the second embodiment of the present disclosure calculates the decision margin time, which is the time until the vehicle 1 starts to take action toward turning right, and obtains one or more candidate passing positions that the vehicle 1 may select when turning right, and the size of the space of each candidate passing position. In addition, the driving assistance device 50 calculates a decision difficulty level based on the decision margin time, the number of candidate passing positions, and the size of the space of the candidate passing positions, and performs a predetermined driving assistance based on the decision difficulty level.

[0133] As a result, the provision of information or automatic control of the vehicle 1 is executed in stages according to the difficulty of the driver's judgment of the candidate passing position, and appropriate driving assistance is executed. In other words, while assisting the driver in turning right by driving the vehicle himself, in a situation where the driver himself has difficulty in responding and the driver may act in a panic, the right turn can be safely completed by automatic control. Therefore, it is possible to suppress an increase in the frequency of forced intervention of automatic control by the driving assistance device 50, increase the driver's reliability of the driving assistance device 50, and increase the safety of the vehicle 1.

[0134] Although the preferred embodiment of the present disclosure has been described in detail above with reference to the attached drawings, the technology of the present disclosure is not limited to such examples. It is clear that a person having ordinary knowledge in the technical field to which the present disclosure belongs can conceive of various modified or amended examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally belong to the technical scope of the present disclosure.

[0135] For example, in the above embodiment, the on-board driving assistance device performed processing to assist in driving the vehicle based on various information, but some of the functions may be possessed by a management server that is communicatively connected to the on-board control device.

[0136] In addition, the technology disclosed herein can also be realized as a vehicle equipped with the driving assistance device described in the above embodiment, a driving assistance processing method by the driving assistance device, a computer program that causes a computer to function as the above driving assistance device, and a non-transitory tangible recording medium on which the computer program is recorded. [Explanation of symbols]

[0137] 1: Vehicle 50: Driving support device 31: Ambient environment sensor 33: Vehicle status sensor 35: Position detection sensor 37: Vehicle-to-vehicle communication device 39: Road-to-vehicle communication device 41: Vehicle control device 43:Notification device 50·50A: Driving support device 51: Processing section 53: Storage section 61: Acquisition part 62: Surrounding environment detection unit 63: Driving scene determination unit 64: Margin of time calculation section 65: Space detection unit 66: Difficulty calculation section 67: Support processing unit

Claims

1. A driving assistance device that assists driving of a vehicle, one or more processors; and one or more memories communicatively coupled to the one or more processors; the one or more processors: a margin time calculation process for calculating a decision margin time, which is a time until the vehicle starts the scheduled action, based on information on the scheduled action of the vehicle and information on a traffic environment around the vehicle; a space detection process for determining one or more candidate destinations that the vehicle may select to achieve the scheduled behavior, and a space size of each of the candidate destinations, based on the information on the scheduled behavior and the information on the traffic environment; a difficulty level calculation process for calculating a difficulty level of a decision to determine one of the destination candidates as a destination based on the decision margin time, the number of the destination candidates, and a space size of the destination candidates; and An assistance process for providing a predetermined driving assistance based on the judgment difficulty level; A driving assistance device that performs the following:

2. the one or more processors: In the difficulty level calculation process, the greater the number of the destination candidates, or the smaller the size of the spaces of the destination candidates and the smaller the difference in size between the spaces, the higher the judgment difficulty level is set. The driving assistance device according to claim 1 .

3. When the judgment difficulty is equal to or greater than a predetermined first standard, the one or more processors: In the assistance process, any one of the destination candidates for which a time required to complete movement to the destination candidate is equal to or shorter than a predetermined standard is determined as the destination, and a process of automatically moving the vehicle is executed. The driving assistance device according to claim 1 .

4. When the judgment difficulty is less than the predetermined first standard and is equal to or greater than the predetermined second standard, the one or more processors: In the assistance process, a process is executed to notify a driver of the vehicle of any of the destination candidates for which a time required to complete movement to the destination candidate is equal to or shorter than the predetermined standard. The driving assistance device according to claim 3.

5. When the judgment difficulty is less than the predetermined second standard and is equal to or greater than a predetermined third standard, the one or more processors: In the assistance process, a content to be notified is set according to an element having a large influence on the difficulty of the decision among the decision margin time, the number of the destination candidates, and the space size of the destination candidates, and a process of notifying a driver of the vehicle of the set content is executed. The driving assistance device according to claim 4.

6. If the scheduled action is a lane change, the one or more processors: In the space detection process, the destination candidate is searched for within a range from a position at a predetermined first distance forward in a traveling direction of the vehicle to a position at a predetermined second distance backward in the traveling direction of the vehicle. The driving assistance device according to claim 1 .

7. A driving assistance processing method for assisting driving of a vehicle, comprising: The computer Calculating a decision margin time, which is a time until the vehicle starts the scheduled action, based on information on the scheduled action of the vehicle and information on a traffic environment around the vehicle; determining one or more candidate destinations that the vehicle may select to achieve the scheduled behavior and a space size of each of the candidate destinations based on the information on the scheduled behavior and the information on the traffic environment; calculating a judgment difficulty level, which is a difficulty level of a judgment for determining any one of the destination candidates as a destination, based on the judgment margin time, the number of the destination candidates, and a space size of the destination candidates; Providing a predetermined driving assistance based on the judgment difficulty level; A driving assistance processing method for performing the above.

8. Computer, Calculating a decision margin time, which is a time until the vehicle starts the scheduled action, based on information on the scheduled action of the vehicle and information on a traffic environment around the vehicle; determining one or more candidate destinations that the vehicle may select to achieve the scheduled behavior and a space size of each of the candidate destinations based on the information on the scheduled behavior and the information on the traffic environment; calculating a judgment difficulty level, which is a difficulty level of a judgment for determining any one of the destination candidates as a destination, based on the judgment margin time, the number of the destination candidates, and a space size of the destination candidates; Providing a predetermined driving assistance based on the judgment difficulty level; A computer program that functions as a driving assistance device that executes the above.

Images