Driving assistance devices

Abstract

To provide an operation support device capable of executing travel support control including steering support control with improved accuracy, smoothness and safety.SOLUTION: A vehicle control device comprises: surrounding situation recognition units 20 and 21; steering holding state recognition sections 34 and 35; and a travel control unit 22 which executes travel support control for a vehicle. The steering holding state recognition section includes a steering torque sensor 35 and a handle touch sensor 34. When determining that an operator is in a state of being unable to maintain normal vehicle travel, the travel control unit performs: first steering holding state determination processing to resume travel support control if output from the handle touch sensor or the steering torque sensor is detected; and second steering holding state determination processing if output from the handle touch sensor or the steering torque sensor is not detected, to resume the travel support control if output from the steering torque sensor is detected and an output value of the steering torque sensor exceeds a predetermined threshold.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a driving assistance device that performs various steering assistance controls, including emergency departure suppression control, which assists steering operations to avoid dangers encountered while a vehicle such as an automobile is traveling, and driver abnormality response control, which is executed while the vehicle is traveling. [Background technology]

[0002] In recent years, development of automatic driving control technology for vehicles such as automobiles that allows the vehicle to travel automatically without the need for driver operation has been progressing. In addition, various driving assistance devices that utilize this type of automatic driving control technology to perform various controls to assist the driver in driving operations have been proposed in recent years, and are gradually being put into practical use.

[0003] Conventional driving assistance devices perform various types of steering assistance control to assist in steering operations to avoid danger, for example, when a vehicle is predicted to be in danger while traveling, such as when it is about to collide with another vehicle, such as an oncoming vehicle or a following vehicle.

[0004] An example of steering assist control performed by a conventional driving assistance device is proposed in, for example, JP 2020-32802 A, in which when a vehicle equipped with a driving assistance device is traveling on a road, a predetermined position (e.g., the center position of the lane) of the driving lane in which the vehicle is traveling is set as a target driving position, and when controlling the vehicle to travel along the set target driving position, steering assistance is provided by an assist steering torque generated using, for example, an electric motor.

[0005] Another example of steering assistance control using a conventional driving assistance device is Lane Departure Prevention (LDP) control, which, when a vehicle equipped with a driving assistance device is about to deviate from the lane it is traveling in to an adjacent lane, provides steering assistance in a direction to prevent the vehicle from deviating from the lane it is traveling in, thereby preventing the vehicle from deviating from the lane it is traveling in. This control has been proposed, for example, in Patent Publication No. 2019-156327.

[0006] Furthermore, in recent years, various proposals have been made for Emergency Lane Keeping (ELK) control, which, when a vehicle equipped with a driving assistance device is in a situation where it is likely to deviate from the lane it is traveling in to an adjacent lane, and if another vehicle, such as an oncoming vehicle or a following vehicle, traveling in the adjacent lane is detected, issues a warning display (visual warning, audible warning, etc.) to that effect, and at the same time, executes driving control with steering assistance substantially similar to the above-mentioned lane departure prevention control, thereby avoiding a collision with the other vehicle (such as an oncoming vehicle or a following vehicle).

[0007] Conventional driving assistance devices are configured so that the driver can individually select on / off for each of the various steering assistance controls (lane keeping assistance control, lane departure prevention control, emergency departure prevention control, etc.) described above, thereby choosing whether or not to enable the control.

[0008] In general, conventional driving assistance devices are provided with a function (so-called steering state determination function) that detects whether a driver is gripping a steering wheel (hereinafter simply referred to as steering) while the vehicle is traveling.

[0009] Conventional driving assistance devices use this steering state determination function to monitor the driver's grip on the steering wheel (hereinafter referred to as the "steering state") while the vehicle is traveling, and if the driver's steering state is not detected for a predetermined time (e.g., 15 seconds) (or while the vehicle is traveling a predetermined distance), the device issues a predetermined warning display (visual warning display, auditory warning display, etc.), and if the driver's hands are subsequently taken off the steering wheel for a predetermined time (e.g., 50 seconds) (or while the vehicle is traveling a predetermined distance), the device cancels the steering assistance control that is currently being implemented. This is due to specifications that comply with, for example, international standards related to automated driving and guidelines established by national competent authorities.

[0010] In conventional driving assistance devices, when the steering assistance control currently being executed is canceled in the above-mentioned situation, it is determined that some abnormality has occurred that makes it difficult for the driver to operate the vehicle (specifically, for example, a malfunction of the vehicle itself, or a decrease in consciousness due to the driver suddenly becoming ill or falling asleep at the wheel, etc.), and various proposals have been made, such as in Patent Publication No. 2019-26210, to execute so-called driver abnormality response control. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Japanese Patent Publication No. 2020-32802 [Patent Document 2] Japanese Patent Application Publication No. 2019-156327 [Patent Document 3] Japanese Patent Application Publication No. 2019-26210 Summary of the Invention [Problem to be solved by the invention]

[0012] As described above, in conventional driving assistance devices, the driver can selectively turn on and off each function of a plurality of types of steering assistance control (lane keeping assistance control, lane departure prevention control, emergency departure prevention control, etc.). Therefore, depending on the combination of selected functions, there is a problem that, for example, a warning display or the like may continue to be displayed unnecessarily, which may be annoying to the driver.

[0013] Specifically, for example, consider a case in which a vehicle is driven with the lane departure prevention control turned off (prohibited) and the emergency departure prevention control turned on (standby for operation) in a conventional driving assistance device. In this case, a situation may arise in which the vehicle is about to deviate from the lane in which it is traveling into an adjacent lane, and at the same time, another vehicle, such as an oncoming vehicle or a following vehicle, traveling in the adjacent lane is detected.

[0014] In such a situation, the driving assistance device of the vehicle detects another vehicle (such as an oncoming vehicle or a following vehicle) and executes emergency departure prevention control, which is in an operation standby state (ON state). At this time, a warning display (such as a visual warning or an audible warning) is first issued, and then steering assistance control, which is substantially the same as lane departure prevention control, is executed. Normally, there is a provision that requires that the warning display must be continued while emergency departure prevention control is being executed until the control is completed.

[0015] Therefore, when emergency departure prevention control is initiated under the above-described circumstances, the vehicle that triggered the initiation of control may move away from the vicinity of the host vehicle by passing or overtaking, etc., and there may be no other vehicles present around the host vehicle. Even in such a case, the warning display will continue until the initiated emergency departure prevention control is completed.

[0016] In other words, after the emergency departure prevention control is initiated, even if there are no other vehicles, such as oncoming vehicles or following vehicles, around the host vehicle and there are no other vehicles that may pose a danger to the host vehicle, the warning display continues to be displayed. In such a situation, not only is the warning display annoying to the driver, but the driver may not understand the meaning of the warning, which may cause the driver to feel uncomfortable.

[0017] On the other hand, some conventional driving assistance devices are configured to determine the steering state by detecting the steering torque applied to the steering device. In such a configuration, for example, when a vehicle running steering assist control is traveling under conditions where minimal steering operation is required, such as on a long, flat, straight road, the generated steering torque value may fall below the threshold for determining the steering state. In such a case, the driving assistance device may erroneously determine that the vehicle is not in the steering state even though the driver is holding the steering wheel and in the steering state. As a result, there is a problem in that the steering assist control being executed is canceled.

[0018] In this way, in conventional driving assistance devices, if a cancellation operation of steering assistance control occurs due to an incorrect determination of the steering state, this is contrary to the driver's intention, and the driver will be forced to start the steering assistance control again, which will be an inconvenience to the driver.

[0019] Therefore, for example, a configuration has been considered in which, in addition to a conventional steering torque sensor, a different sensor, such as a steering wheel touch sensor that detects the state of grip by touching the steering wheel, is added as a means for determining the state of steering. By adopting such a configuration, it is possible to reliably determine the state of steering by the driver, and further improvements in convenience can be expected.

[0020] However, if a steering wheel touch sensor is provided in addition to a steering torque sensor as a means for determining the steering state, a new problem arises in that the steering wheel touch sensor is likely to cause an erroneous determination, for example, when a survival determination is made when driver abnormality response control is executed.

[0021] The present invention has been made in consideration of the above-mentioned points, and its object is to provide a driving assistance device mounted on a vehicle such as an automobile that can always perform more natural and smooth steering assistance control without causing the driver any inconvenience or discomfort, even when multiple types of steering assistance control are combined.

[0022] At the same time, the present invention aims to provide a driving assistance device that can suppress erroneous judgments in determining the steering state while steering assistance control is being executed while the vehicle is traveling and in determining whether the vehicle is still in a stable state while driver abnormality response control is being executed, thereby making more accurate and reliable judgments and performing more reliable, smoother, and safer driving assistance control, including steering assistance control and driver abnormality response control. [Means for solving the problem]

[0023] In order to achieve the above object, a driving assistance device according to one aspect of the present invention is a driving assistance device including a surrounding situation recognition device that recognizes the surrounding situation of a host vehicle, a steering state recognition unit that recognizes a steering state of the host vehicle, and a driving control device that performs driving assistance control of the host vehicle based on the recognition results by the surrounding situation recognition device and the steering state recognition unit, wherein the steering state recognition unit includes a steering torque sensor provided on a steering shaft and a steering wheel touch sensor provided on a steering wheel, and when the driver of the host vehicle does not interfere with the steering device for a predetermined time period or while the host vehicle has traveled a predetermined distance and this is not detected by the steering state recognition unit, the driving control device determines that the driver of the host vehicle is in a state where he or she is unable to maintain normal driving, and If it is determined that the output of the steering wheel touch sensor or the steering torque sensor is not detected in the first held steering state determination process, a second held steering state determination process is performed in the held steering state recognition unit to detect only the output of the steering torque sensor after a predetermined time has elapsed or after the vehicle has traveled a predetermined distance, and if the output of the steering torque sensor is detected and the output value of the steering torque sensor exceeds a predetermined threshold, the driving assistance control is restored. [Effects of the Invention]

[0024] According to the present invention, a driving assistance device can be provided that is mounted on a vehicle such as an automobile, and that can always perform more natural and smooth steering assistance control without causing the driver any inconvenience or discomfort, even by combining multiple types of steering assistance control.

[0025] At the same time, it is possible to provide a driving assistance device that can suppress erroneous judgments in determining the steering state while steering assistance control is being executed while the vehicle is traveling and in determining whether the vehicle is alive while driver abnormality response control is being executed, thereby making more accurate and reliable judgments and performing more reliable, smoother, and safer steering assistance control and driving assistance control including driver abnormality response control. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a block diagram showing a schematic configuration of a driving assistance device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a diagram for explaining the operation of normal lane departure suppression control performed in the driving assistance device of the present embodiment; [Figure 3] FIG. 2 is a diagram illustrating an example of the operation of the emergency departure suppression control performed in the driving assistance device of the present embodiment (response to an oncoming vehicle in the first emergency departure suppression control); [Figure 4] FIG. 10 is a diagram illustrating another example of the operation of the emergency departure suppression control performed in the driving assistance device of the present embodiment (first emergency departure suppression control for a following vehicle); [Figure 5] FIG. 10 is a diagram illustrating another example of the operation of the emergency departure prevention control performed in the driving assistance device of the present embodiment (response to an oncoming vehicle in the second emergency departure prevention control); [Figure 6] 1 is a flowchart showing lane departure control and emergency departure suppression control performed in the driving assistance device of this embodiment; [Figure 7] 7 is a flowchart of a subroutine of the first emergency deviation suppression control (processing of step S13) of FIG. [Figure 8] 7 is a flowchart of a subroutine of the second emergency deviation suppression control (processing of step S16) of FIG. [Figure 9] FIG. 2 is a diagram for explaining the outline of the operation of the driver abnormality response control performed in the driving assistance device of the present embodiment; [Figure 10] 1 is a flowchart illustrating a start timing of driver abnormality response control in the driving assistance device of this embodiment; [Figure 11]11 is a flowchart showing details of the driver abnormality response control (processing of step S49) in FIG. 10. DETAILED DESCRIPTION OF THE INVENTION

[0027] The present invention will be described below with reference to the illustrated embodiments. The drawings used in the following description are schematic, and the dimensional relationships and scales of the components may be different for each component in order to show each component at a size that allows it to be recognized on the drawing. Therefore, the present invention is not limited to the illustrated embodiments in terms of the number of components shown in the drawings, the shapes of the components, the size ratios of the components, the relative positional relationships of the components, and so on.

[0028] A driving assistance device according to one embodiment of the present invention is a device that is mounted on a vehicle such as an automobile and performs driving control to assist the driver of the vehicle in driving operations.

[0029] The driving assistance device of this embodiment acquires information about the situation ahead of and around the vehicle (for example, information about the situation around the vehicle, including other vehicles traveling ahead and around the vehicle (leading vehicle, following vehicle, oncoming vehicle, vehicle traveling alongside, etc.), bicycles, pedestrians, obstacles, etc.; hereinafter simply referred to as surrounding situation information, etc.) using a sensor device (sensing device) such as an on-board camera unit or a radar device. In addition to the acquired surrounding situation information data, the driving assistance device recognizes road conditions, etc., related to leading vehicles, following vehicles, and various obstacles, based on road map information, etc. acquired from an external device, such as a high-precision road map database, via communication. The driving assistance device of this embodiment then appropriately uses these various pieces of information (surrounding situation information, etc., map information, etc., recognition information, etc.) as information when executing cruise control to assist the driver in driving operations.

[0030] First, the schematic configuration of a driving assistance device according to one embodiment of the present invention will be described below with reference to the block diagram of FIG.

[0031] The configuration of the driving assistance device 1 of this embodiment is basically substantially the same as the configuration of a conventional driving assistance device. Therefore, when describing the configuration of the driving assistance device 1 of this embodiment, only the main configuration of the device will be briefly described. As the detailed configuration of the driving assistance device 1 of this embodiment is substantially the same as that of a conventional driving assistance device, a detailed description of the configuration other than that directly related to the present invention will be omitted. Furthermore, in FIG. 1, only the main configuration of the driving assistance device 1 of this embodiment is illustrated, and configurations not directly related to the present invention are omitted.

[0032] As shown in FIG. 1, the driving assistance device 1 of this embodiment includes, as main components, a locator unit 11, a periphery monitoring unit 20, a camera unit 21, a driving control unit 22 which is a driving control device, an engine control unit 23, a power steering control unit 24, a brake control unit 25, etc.

[0033] Here, the locator unit 11, the periphery monitoring unit 20, and the camera unit 21 are constituent units that function as sensor units (environment recognition devices) for recognizing the driving environment inside and outside the vehicle. These units (11, 20, 21) do not depend on each other and exist as completely independent constituent units.

[0034] Each control unit, namely, the driving control unit 22, the engine control unit 23, the power steering control unit 24, and the brake control unit 25, together with the locator unit 11, the surroundings monitoring unit 20, and the camera unit 21, are connected to each other via an in-vehicle communication line 10 such as a CAN (Controller Area Network), and share data as appropriate and as needed.

[0035] Locator unit 11 is an information acquisition device that estimates the position of the vehicle (vehicle position) on a road map and acquires road map information, etc., mainly for the area ahead of the estimated vehicle position.

[0036] Locator unit 11 includes a map locator calculation unit 12, an acceleration sensor 13, a wheel speed sensor 14, a gyro sensor 15, a GNSS receiver 16, a road information receiver 17, a high-precision road map database (DB; Data Base; abbreviated as road map DB in FIG. 1) 18 as a map information storage unit, and a route information input unit 19.

[0037] Of these, the acceleration sensor 13, the wheel speed sensor 14, and the gyro sensor 15 are various sensors required to estimate the position of the host vehicle (host vehicle position). For example, the acceleration sensor 13 is a sensor that detects the longitudinal acceleration of the host vehicle. The wheel speed sensor 14 is a sensor that detects the rotational speed of each of the front, rear, left, and right wheels. The gyro sensor 15 is a sensor that detects the angular velocity or angular acceleration of the host vehicle. These sensors (13, 14, 15) are a group of autonomous driving sensors that function as a driving state acquisition unit, and are connected to the input side of the map locator calculation unit 12.

[0038] The autonomous driving sensor group (sensors 13, 14, 15) is a sensor group provided to enable autonomous driving when, for example, the receiving sensitivity from GNSS satellites (not shown) decreases and the positioning signal cannot be effectively received, such as when driving through a tunnel. The autonomous driving sensor group may include, in addition to the above-mentioned sensors (13, 14, 15), a vehicle speed sensor, a yaw rate sensor, etc.

[0039] The GNSS receiver 16 functions as a vehicle position acquisition unit and is a receiving device that receives various information from, for example, a GNSS (Global Navigation Satellite System). That is, the GNSS receiver 16 receives positioning signals transmitted from a plurality of positioning satellites. The GNSS receiver 16 outputs the acquired positioning signals to the map locator calculation unit 12 of the locator unit 11. The map locator calculation unit 12 estimates the vehicle position (latitude, longitude) based on the positioning signals received by the GNSS receiver 16 from the plurality of positioning satellites. For this reason, the GNSS receiver 16 is connected to the input side of the map locator calculation unit 12.

[0040] Furthermore, the map locator calculation unit 12 is connected to a road information receiver 17, a high-precision road map database 18 as a storage means, a route information input unit 19, and the like.

[0041] Road information receiver 17 is a receiving device that receives and acquires various information, such as information necessary for autonomous driving and map information, stored in a predetermined base station (not shown) or a cloud server (not shown) connected via the Internet. Road information receiver 17 outputs the acquired various information to map locator calculation section 12 of locator unit 11. Note that road information receiver 17 may further have a function of transmitting various information about the vehicle to the base station or cloud server (not shown), and may take the form of a road information transmitting and receiving device.

[0042] Map locator calculation unit 12 performs map matching of the vehicle's position on a map based on map information received by road information receiver 17, and constructs a target driving route connecting the input destination and the vehicle's position. Furthermore, map locator calculation unit 12 sets a target driving route for executing autonomous driving up to several kilometers ahead of the vehicle on the constructed target driving route. Here, items set as the target driving route include the lane in which the vehicle will travel (for example, which lane to travel in if there are three lanes), lane changes to overtake a preceding vehicle, and the timing to start the lane change.

[0043] The high precision road map database 18 is mainly composed of large-capacity storage media such as HDDs (Hard Disk Drives) and SSDs (Solid State Drives). Well-known high precision road map information (local dynamic maps) is stored in this high precision road map database 18. Here, the high precision road map information has the same layer structure as a global dynamic map stored in, for example, a cloud server (not shown), and forms a hierarchical structure in which additional map information necessary to support automated driving is superimposed on the lowest static information layer that serves as the base.

[0044] The additional map information includes static location information such as road type (general road, expressway, etc.), road shape, left and right dividing lines (lane boundaries), exits to expressways and bypass roads, etc., and entrance / exit lengths (start and end positions) of branching lanes and merging lanes that lead to junctions, service areas, parking areas, etc., as well as dynamic location information such as traffic congestion information and traffic restrictions due to accidents or construction work.

[0045] As will be described later, when a target driving route is set by the map locator calculation unit 12, this additional map information is continuously acquired from the global dynamic map and sequentially updated as surrounding information required for the vehicle to autonomously drive along the set target driving route.

[0046] High-precision road map information also contains lane data required for autonomous driving, such as lane width data, lane center position coordinate data, lane heading angle data, speed limit information, etc. This lane data and other information is stored at intervals of several meters for each lane on the road map.

[0047] Route information input unit 19 is a terminal device operated by a person on board the vehicle, such as a driver or a passenger. Route information input unit 19 can collect and input a series of information required to set a target driving route in map locator calculation unit 12, such as setting a destination and intermediate points (such as a service area on a highway).

[0048] Specifically, route information input unit 19 is an input unit of a car navigation system (for example, a touch panel of a monitor, etc.), a mobile terminal such as a smartphone, a personal computer, etc. Route information input unit 19 is connected to map locator calculation unit 12 via a wired or wireless connection. As a result, when a driver or passenger operates route information input unit 19 to input information about a destination or a stopover point (facility name, address, telephone number, etc.), the input information is read into map locator calculation unit 12. Map locator calculation unit 12 sets the position coordinates (latitude, longitude) of the destination or stopover point input from route information input unit 19.

[0049] The map locator calculation unit 12 includes a vehicle position estimation unit 12a, a map information acquisition unit 12b, and the like.

[0050] The vehicle position estimation unit 12a is a unit that estimates the position of the vehicle. The vehicle position estimation unit 12a acquires the position coordinates (latitude, longitude) of the vehicle based on the positioning signal received by the GNSS receiver 16. Then, the vehicle position estimation unit 12a performs map matching of the acquired position coordinates on route map information to estimate the vehicle position (current position) on the road map.

[0051] Furthermore, in an environment where valid positioning signals from positioning satellites cannot be received due to reduced sensitivity of the GNSS receiver 16, such as when driving inside a tunnel, the vehicle position estimation unit 12a switches to autonomous navigation, which estimates the vehicle position based on vehicle speed data obtained based on the wheel speeds detected by the wheel speed sensors 14, angular velocity data detected by the gyro sensor 15, longitudinal acceleration data detected by the acceleration sensor 13, etc., and estimates the vehicle position (latitude, longitude) on a road map.

[0052] The map information acquisition unit 12b constructs information on a target driving route from the current location to the destination (target driving route information connecting the vehicle's position on the high-precision road map information with the destination (or the destination via the via point if one is set)) based on the position information (latitude, longitude) of the vehicle's position estimated by the vehicle position estimation unit 12a and the position information (latitude, longitude) of the destination and the via point input by the driver or the like via the route information input unit 19, in accordance with preset route conditions (recommended route, fastest route, etc.). At this time, the vehicle position estimation unit 12a identifies the driving lane in which the vehicle is traveling, acquires road shapes such as driving lanes and merging lanes stored in the road map data, and sequentially stores this information. The map information acquisition unit 12b also transmits the target driving route information to the vehicle position estimation unit 12a.

[0053] In this way, the map locator calculation unit 12 matches the vehicle position estimated by the vehicle position estimation unit 12a with a road map to identify the current location of the vehicle, acquires road map information including information about the surrounding conditions, and sets a target driving route for the vehicle by the map information acquisition unit 12b.

[0054] The camera unit 21 is a surrounding situation information acquisition device that recognizes the situation mainly in the traveling direction (forward) of the vehicle and acquires the information, and forms part of a surrounding situation recognition device.

[0055] Specifically, the camera unit 21 recognizes, for example, other vehicles traveling in front of or to the side of the vehicle (such as a preceding vehicle or a vehicle traveling alongside), as well as three-dimensional objects including moving objects (hereinafter simply referred to as moving objects, etc.) such as bicycles and motorcycles traveling alongside, traffic light indications (lighting color, flashing state, arrow direction, etc.), road signs, stop lines, lane boundary lines, and other road markings, as well as various road surrounding conditions.

[0056] The camera unit 21 is fixed to the upper center of the front interior of the vehicle and includes an on-board camera (stereo camera) consisting of a main camera 21a and a sub-camera 21b arranged symmetrically across the center of the vehicle width, an image processing unit (IPU) 21c, a driving environment recognition unit 21d, etc. The camera unit 21 captures reference image data with the main camera 21a and captures comparison image data with the sub-camera 21b. The two image data acquired by these two cameras 21a and 21b are subjected to predetermined image processing by the IPU 21c.

[0057] The driving environment recognition unit 21d reads the reference image data and the comparison image data that have been image-processed by the IPU 21c, recognizes the same object in both images based on the parallax between the two images, and calculates the distance data (information on the distance from the vehicle to the object) using the principle of triangulation, and recognizes it as information on the forward situation.

[0058] Furthermore, the camera unit 21 recognizes, for example, dividing lines (lane boundary lines) that divide the left and right sides of the lane in which the vehicle is traveling as forward situation information.

[0059] Here, the forward situation information includes various information such as the road shape of the road on which the vehicle is traveling (such as merging lanes and driving lanes) (lane boundary lines that separate the vehicle into left and right lanes and indicate the lanes, the road curvature [1 / m] at the center between the lanes, and the width between the left and right lanes (lane width)), entrances and exits to expressways and bypass roads, lane widths between merging lanes and diverging lanes that connect to junctions, intersections, crosswalks, traffic lights, road signs, and roadside obstacles (such as utility poles, telephone poles, parked vehicles), as well as image information showing the behavior of other vehicles traveling in front of and around the vehicle. This forward situation information is output to the cruise control unit 22.

[0060] Furthermore, the driving environment recognition unit 21d performs predetermined pattern matching on the distance image information to recognize guardrails, curbs, and three-dimensional objects along the road. Here, the recognition of three-dimensional objects by the driving environment recognition unit 21d recognizes, for example, the type of three-dimensional object, the distance to the three-dimensional object, the speed of the three-dimensional object, and the relative speed between the three-dimensional object and the vehicle.

[0061] Each of the cameras 21a and 21b may have a function of acquiring sound information simultaneously with image information. In this case, the sound information acquired simultaneously with the image information is included in the forward situation information as sound information related to the situation ahead of the vehicle.

[0062] The periphery monitoring unit 20 is a peripheral situation information acquisition device that recognizes the situation around the vehicle and acquires the information, and forms part of a peripheral situation recognition device. This periphery monitoring unit 20 is configured with a peripheral situation recognition sensor 20a, a peripheral environment recognition unit 20b, etc.

[0063] The surrounding situation recognition sensor 20a is a group of autonomous sensors as surrounding situation detection means, which includes sensing devices such as an ultrasonic sensor, a millimeter wave radar, a LIDAR (Light Detection and Ranging), a camera, and a combination of these.

[0064] Specifically, for example, a plurality of millimeter-wave radars serving as surrounding situation recognition sensors 20a are disposed at the four corners of the vehicle (for example, left front side, right front side, left rear side, right rear side, etc.). Of these, the left and right front-side millimeter-wave radars are provided, for example, on the left and right sides of the front bumper, and are used to monitor some areas around the vehicle that are difficult to recognize using images acquired by the two cameras 21a, 21b of camera unit 21 (areas diagonally forward and to the left and right of the vehicle).

[0065] In addition, the left and right rear side millimeter wave radars are provided, for example, on the left and right sides of the rear bumper, and are used to monitor some areas around the vehicle (areas from the sides to the rear of the vehicle) that cannot be monitored by the left and right front side millimeter wave radars.

[0066] The surrounding environment recognition unit 20b acquires surrounding situation information, which is information about moving objects around the vehicle (e.g., vehicles traveling alongside, following vehicles traveling in the vehicle's lane or an adjacent lane, oncoming vehicles, etc.), based on the output signal from the surrounding situation recognition sensor 20a.

[0067] The periphery monitoring unit 20 and the camera unit 21 constitute a peripheral situation information acquisition device and a peripheral situation recognition device in the driving assistance device 1 of this embodiment. Here, the driving environment recognition unit 21d of the camera unit 21 and the peripheral environment recognition unit 20b of the periphery monitoring unit 20 are connected to the input side of the cruise control unit 22 via the in-vehicle communication line 10. Furthermore, the cruise control unit 22 and the map locator calculation unit 12 are connected to each other so as to enable bidirectional communication via the in-vehicle communication line 10. Furthermore, a mode selector switch 33, a steering wheel touch sensor 34, a steering torque sensor 35, a brake sensor 36, an accelerator sensor 37, and the like are connected to the input side of the cruise control unit 22 as a plurality of various switches or a plurality of sensor groups that detect information about the internal situation of the vehicle.

[0068] The mode selector switch 33 refers to a group of switches that the driver switches on and off to select various driving modes and multiple control functions related to driving assistance control. By operating the mode selector switch 33, the driver can selectively switch on and off various driving modes, such as the manual driving mode, the first driving assistance mode, the second driving assistance mode, and the evacuation mode.

[0069] Here, the manual driving mode is a driving mode that requires the driver to maintain steering, for example, a driving mode in which the vehicle is driven according to the driver's driving operations (steering, accelerator, brake, etc.).

[0070] The first driving assistance mode is a semi-automated driving mode that requires the driver to maintain steering, and that reflects the driver's driving operation while assisting the driver's operation in accordance with the circumstances of the vehicle's surrounding environment recognized by various sensors, etc. In other words, the first driving assistance mode is a semi-automated driving mode that controls, for example, the engine control unit 23, power steering control unit 24, brake control unit 25, etc., and mainly performs a combination of various controls such as preceding vehicle following control, lane keeping assist control, lane departure suppression control, and emergency departure suppression control, thereby causing the vehicle to travel along a set target driving route.

[0071] The second driving assistance mode is an autonomous driving mode in which the vehicle automatically travels along a target driving route by combining mainly preceding vehicle following control, lane keeping assist control, lane departure prevention control, etc. through control by, for example, the engine control unit 23, power steering control unit 24, brake control unit 25, etc., without requiring the driver to maintain steering, operate the accelerator, or operate the brakes.

[0072] The evacuation mode is an emergency driving mode for automatically and safely stopping the vehicle when, for example, the vehicle is unable to continue driving while driving in the first or second driving assistance mode and the driving operation cannot be handed over to the driver (i.e., when transition to the manual driving mode or the first driving assistance mode cannot be made). The control executed in this evacuation mode is control called "driver abnormality response control" which will be described later.

[0073] Furthermore, the mode changeover switch 33 is also an operating member that allows the driver to selectively switch on and off each function, such as lane keeping assist control, lane departure suppression control, and emergency departure suppression control, among the various types of steering assist control.

[0074] The steering wheel touch sensor 34 is a sensor for detecting a state in which the driver is gripping a steering wheel (not shown) of a steering device, i.e., a holding state. The steering wheel touch sensor 34 is provided on the steering wheel of the vehicle (hereinafter simply referred to as the steering wheel). The steering wheel touch sensor 34 outputs an ON signal when the steering wheel is being gripped (when the steering wheel is in a holding state).

[0075] The steering torque sensor 35 is a sensor that detects steering torque as a driving operation amount by the driver, and is provided on a steering shaft (not shown) of a steering device of the vehicle.

[0076] The steering wheel touch sensor 34 and the steering torque sensor 35 are sensors for recognizing the state of the steering wheel maintained by the driver of the vehicle, and are a maintained steering state recognition unit. The output signals of these two sensors (34, 35) are output to the cruise control unit 22 (a maintained steering state determination unit 22b; described later).

[0077] The brake sensor 36 is a sensor that detects the amount of depression of the brake pedal as a driving operation amount by the driver.The accelerator sensor 37 is a sensor that detects the amount of depression of the accelerator pedal as a driving operation amount by the driver.

[0078] Meanwhile, an alarm device 38 such as a monitor panel or a speaker is connected to the output side of the driving control unit 22. The alarm device 38 is a device that issues an alarm to the driver (for example, a visual alarm display on a display device such as a monitor panel, or an auditory alarm display using a sound device such as a speaker or a horn) according to the situation recognized by the driving control unit 22 based on the forward situation information, surrounding situation information, etc. acquired by the driving environment recognition unit 21 d, the surrounding environment recognition unit 20 b, etc.

[0079] In addition, the notification device 38 may, in some cases, provide various displays to the driver that suggest the operation the driver should perform (specifically, suggestive notifications such as "Please press the brake pedal," "Please release the accelerator," "Please make steering corrections," etc.) that the driver may perceive audibly or visually.

[0080] The driving control unit 22 is configured to include a surrounding situation determination unit 22a, a steering state determination unit 22b, a driving lane setting unit 22c, a steering assistance control unit 22d, and the like.

[0081] The surrounding situation determination unit 22a determines the surrounding situation of the vehicle based on the recognition results of the surrounding situation recognition device (surroundings monitoring unit 20, camera unit 21).

[0082] The steering state determination unit 22b determines the steering state of the driver of the vehicle based on the recognition result by the steering state recognition unit (steering wheel touch sensor 34, steering torque sensor 35).

[0083] The driving lane setting unit 22c sets the driving lane in which the vehicle will travel based on the surrounding situation recognition device, i.e., the forward situation information recognized by the driving environment recognition unit 21d of the camera unit 21, and the surrounding situation information of the vehicle recognized by the surrounding environment recognition unit 20b of the surrounding monitoring unit 20.

[0084] Here, the driving lane setting unit 22c receives, for example, lane recognition information contained in the forward situation information from the camera unit 21, calculates the road curvature at the center of the left and right dividing lines (lane boundary lines) of the lane in which the vehicle is driving, and detects the lateral position deviation of the vehicle in the vehicle width direction based on the center of these left and right dividing lines.

[0085] Various methods are known for determining the road curvature and lane width at the center between lane lines. For example, the driving environment recognition unit 21d recognizes left and right lane lines by binarizing the road curvature based on brightness differences based on forward driving environment image information, determines the curvature of the left and right lane lines for each predetermined section using a curve approximation formula based on the least squares method, and calculates the vehicle width from the difference in curvature between the two lane lines. The driving environment recognition unit 21d then determines the road curvature at the lane center based on the curvature of the left and right lane lines and the lane width, and further calculates the lateral position deviation of the vehicle relative to the lane center—more precisely, the distance from the lane center to the center of the vehicle in the vehicle width direction.

[0086] The steering assist control unit 22d performs various steering assist controls to assist the driver in steering operations to avoid dangers that the vehicle may encounter while traveling, in addition to steering operations to keep the vehicle stable within the travel lane.

[0087] The steering assist control unit 22d includes a target traveling position setting unit 22e, an avoidance determination unit 22f, a lane departure determination unit 22g, and the like.

[0088] The target driving position setting unit 22e sets a target driving position (for example, the center position of the lane) of the vehicle within the driving lane set by the driving lane setting unit 22c.

[0089] The avoidance determination unit 22f determines whether or not the vehicle needs to take evasive action to avoid a specified target when the surrounding situation recognition device recognizes that a specified target exists ahead on the extension of the target traveling position set by the target traveling position setting unit.

[0090] The lane departure determination unit 22g determines a lane departure situation, such as whether the host vehicle is likely to deviate from the driving lane set by the driving lane setting unit 22c into an adjacent lane, while traveling in the driving lane. Furthermore, when the avoidance determination unit 22f determines that evasive action is necessary for a target ahead that has been recognized, the lane departure determination unit 22g determines a lane departure situation, such as whether the host vehicle will deviate from the driving lane if the host vehicle takes evasive action, based on the lateral positional relationship between the host vehicle and the target.

[0091] The driving control unit 22 performs various predetermined situation judgments using the surrounding situation judgment unit 22a and the steering state judgment unit 22b, etc., based on output information from the driving environment recognition unit 21d of the camera unit 21 and the surrounding environment recognition unit 20b of the surrounding monitoring unit 20, i.e., the surrounding situation recognition device, as well as various information obtained through the map locator calculation unit 12, and vehicle internal situation information obtained from the mode changeover switch 33 and various sensors (34, 35, 36, 37), etc., and controls the driving of the vehicle through the engine control unit 23, power steering control unit 24, brake control unit 25, etc., based on the judgment results.

[0092] If an automatic driving section in which automatic driving control is permitted is set within the target driving route set by the map locator calculation section 12, the driving control unit 22 sets a driving route for performing automatic driving control in the automatic driving section. In the automatic driving section, the driving control unit 22 also has a function of appropriately controlling the engine control unit 23, power steering control unit 24, brake control unit 25, etc. to automatically drive the vehicle in the second driving assistance mode along the target driving route set from the vehicle position estimated based on various information.

[0093] At that time, the driving control unit 22 makes the host vehicle follow the preceding vehicle when a preceding vehicle is detected, for example, by preceding vehicle following control, lane keeping assist control, etc. based on the forward situation information recognized by the driving environment recognition unit 21d, and makes the host vehicle travel at a set vehicle speed within the speed limit when a preceding vehicle is not detected. Also, it executes steering assist control selected appropriately, such as lane keeping assist control, lane departure suppression control, emergency departure suppression control, etc., and further performs driving control such as driver abnormality response control in some cases.

[0094] In addition, the driver abnormality response control is a technology for safely and automatically stopping the vehicle when, for example, in the driving assistance device 1 of this embodiment, while automatic driving control is being performed, the device is unable to hand over driving operations to the driver.

[0095] As described above, the cruise control unit 22 is connected to each of the control units, such as the engine control unit 23, the power steering control unit 24, and the brake control unit 25, via the in-vehicle communication line 10. In this way, the cruise control unit 22 controls each of the control units (23, 24, 25), etc.

[0096] A throttle actuator 27 is connected to the output side of the engine control unit 23. This throttle actuator 27 opens and closes a throttle valve of an electronically controlled throttle provided in a throttle body of the engine, and generates a desired engine output by opening and closing the throttle valve in response to a drive signal from the engine control unit 23 to adjust the intake air flow rate.

[0097] An electric power steering motor 28 is connected to the output side of the power steering control unit 24. This electric power steering motor 28 applies steering torque to the steering mechanism by the rotational force of the electric motor. In driving modes other than the manual mode (first and second driving assistance modes, evacuation mode, etc.), various steering assistance controls that assist steering operation (i.e., steering) are executed by controlling the operation of the electric power steering motor 28 using a drive signal from the power steering control unit 24. In addition, a steering torque sensor 35 indicates a steering torque value by detecting changes in the drive amount of the electric power steering motor 28 or the drive amount of the steering mechanism, etc.

[0098] A brake actuator 29 is connected to the output side of the brake control unit 25. This brake actuator 29 adjusts the brake hydraulic pressure supplied to the brake wheel cylinders provided on each wheel, and when the brake actuator 29 is driven by a drive signal from the brake control unit 25, the brake wheel cylinders generate braking force on each wheel, forcibly decelerating the vehicle.

[0099] The map locator calculation unit 12, the surrounding environment recognition unit 20b, the driving environment recognition unit 21d, the driving control unit 22, the engine control unit 23, the power steering control unit 24, the brake control unit 25, etc. are configured by, for example, a well-known microcomputer including a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), a non-volatile storage unit, etc., and its peripheral devices, etc. The ROM stores in advance programs to be executed by the CPU, fixed data such as data tables, etc. The above is a schematic configuration of the driving assistance device 1 of this embodiment.

[0100] The operation of the driving assistance device according to one embodiment of the present invention configured as described above will be described below. In describing this embodiment, a road system based on left-hand traffic, in which the vehicle's traffic zone is on the left side, is used as an example. Therefore, application to a road system based on right-hand traffic can be easily achieved by simply switching the left and right sides.

[0101] First, the basic operations of the lane departure suppression control and the emergency departure suppression control among the steering assist controls executed by the driving assist device 1 of this embodiment will be described below.

[0102] FIG. 2 is a diagram illustrating an outline of normal lane departure prevention control performed in the driving assistance device 1 of this embodiment. The lane departure prevention control performed in the driving assistance device 1 of this embodiment is basically substantially the same as conventionally known lane departure prevention control. The following explanation is a simplified explanation of the basic operation when lane departure prevention control is executed alone. Therefore, the explanation of FIG. 2 only explains the operation of lane departure prevention control, and does not take into account the on / off states of other controls, or the intervention and influence of these other controls.

[0103] The example shown in Figure 2 assumes that the vehicle 100 is traveling in the left lane RL on a road R with alternating traffic and one lane in each direction. Here, the road R consists of a lane RL on the left side as seen from the driver of the vehicle 100 and a lane RR adjacent to the right side of the left lane RL. The left lane RL is the area between the left shoulder marking L1 and the center marking L2. The right lane RR is the area between the center marking L2 and the right shoulder marking L3.

[0104] In this case, the host vehicle 100 is traveling in the left lane RL as its own lane (host lane). The driving assistance device 1 mounted on the host vehicle 100 is set to an ON state in which the lane departure prevention control among the steering assistance controls is activated. Note that other controls are not taken into consideration in FIG. 2.

[0105] In this situation, the driving assistance device 1 of the vehicle 100 recognizes the dividing lines (L1, L2) on both sides of the vehicle's lane (by the surrounding situation recognition device (20, 21)), sets the lane RL in the area between the recognized dividing lines (L1, L2) as the driving lane in which the vehicle 100 should travel (by the driving lane setting unit 22c), and sets, for example, the center position of the lane as the target driving position of the vehicle 100 within the set driving lane RL (by the target driving position setting unit 22e).

[0106] Here, consider a case where the vehicle 100 is about to deviate from the driving lane RL into the adjacent lane RR (the oncoming lane in the example of FIG. 2). In this case, the vehicle 100 is located at the position indicated by the symbol A in FIG. 2 and is in the attitude shown in FIG.

[0107] Specific situations in which the host vehicle may deviate from the driving lane into an adjacent lane include, for example, when the vehicle moves to the left or right instead of going straight due to a lateral gradient on the road on which the vehicle is traveling. Other examples include a malfunction of the host vehicle, when the driver is distracted while driving, when the driver falls asleep due to fatigue, or when the driver becomes depressed due to sudden illness. In addition, for example, when the host vehicle is traveling on a set target driving route, the presence of a predetermined target on the target driving route is recognized, and the driver performs a sudden steering operation as an evasive action to cause the host vehicle to avoid the target, and the host vehicle may deviate from the driving lane.

[0108] 2, the host vehicle 100 is in a situation where a line along the front-to-rear direction of the host vehicle 100 and along the vector (arrow symbol S1) of the traveling direction of the host vehicle 100 at this time (position A) is inclined at a predetermined angle with respect to the dividing lines L1 and L2 on both sides of the traveling lane RL of the host vehicle 100. Therefore, if the host vehicle 100 continues to travel along the vector of the traveling direction of the arrow symbol S1, the host vehicle 100 is expected to cross over the dividing line L2 and then deviate into the adjacent lane RR (oncoming lane) (determined by the lane departure determination unit 22g).

[0109] Therefore, in the driving assistance device 1 of the host vehicle 100, when the lane departure determination unit 22g determines that the host vehicle 100 is about to deviate from the driving lane, steering assistance control is executed to suppress lane departure. The steering assistance control executed here is a control to rotate the steering wheel in a right-left rotation direction. In FIG. 2, the state in which the steering wheel is being rotated in the left rotation direction (arrow L direction) is indicated by reference numeral 101L, and the state in which the steering wheel is being rotated in the right rotation direction (arrow R direction) is indicated by reference numeral 101R. Also, in FIG. 2, the state in which the steering wheel is in the neutral position is indicated by reference numeral 101C.

[0110] The lane departure suppression control first performs steering operation assistance control (steering assistance control) so that the vehicle 100 traces a turning trajectory until the angle (referred to as lane yaw angle) between a line along the longitudinal direction of the vehicle 100 (for example, a line along the arrow symbol S1) and the dividing line L2 becomes zero (i.e., until the line along the longitudinal direction of the vehicle 100 (line along the arrow symbol S1) and the dividing line L2 become parallel). The steering assistance control at this time is performed in the region indicated by symbol AB in FIG. 2.

[0111] Then, when the vehicle 100 reaches the position indicated by the symbol B in FIG. 2, the line along the longitudinal direction of the vehicle 100 (the line along the arrow symbol S2 at this point (position B)) becomes parallel to the lane marking L2. The vector of the traveling direction of the vehicle 100 at this time is indicated by the arrow symbol S2 in FIG. 2. Here, the steering control performed from position A to position B is referred to as the "first stage control processing."

[0112] When the vehicle 100 is at the position indicated by the symbol B, the vehicle 100 is traveling along the lane marking L2 without crossing the lane marking L2. In this state, a part of the vehicle 100 (a part near the right side) may be traveling into the adjacent lane (oncoming lane) RR.

[0113] Therefore, the driving assistance device 1 guides the host vehicle 100 into the area of ​​the driving lane RL and executes steering assistance control and driving assistance control so that the right side of the host vehicle 100 travels along the inner edge (lane edge) of the dividing line L2. The steering assistance control at this time is performed in the area indicated by the symbol BD in Fig. 2. The vector of the traveling direction of the host vehicle 100 traveling in this area is indicated by the arrow symbol S3 in Fig. 2.

[0114] When the vehicle 100 reaches the position indicated by symbol D in FIG. 2, the line along the longitudinal direction of the vehicle 100 (the line along arrow symbol S4 at this point (position D)) and the lane marking L2 become parallel again. The vector of the traveling direction of the vehicle 100 at this time is indicated by arrow symbol S4 in FIG. 2. Once the line along the longitudinal direction of the vehicle 100 (S4) and the lane marking L2 become parallel at position D in FIG. 2, the vehicle will then continue to travel along the lane marking L2 while maintaining this state for a predetermined period of time. Here, the steering control performed from position B to position D will be referred to as the "second stage control processing."

[0115] The traveling state of the host vehicle 100 during the predetermined time period after passing the position indicated by the symbol D is a state in which the host vehicle 100 is traveling along the inner edge (lane edge) of the lane marking L2 in the area within the traveling lane RL. In other words, the host vehicle 100 moves to the lane edge of the traveling lane and travels while maintaining that lane edge position. At this point, the host vehicle 100 has avoided the risk of collision with an oncoming vehicle.

[0116] However, when the vehicle 100 passes position D in Fig. 2 and continues traveling along the lane marking L2, there is a high possibility that the vehicle 100 will deviate from the lane again. Therefore, the driving assistance device 1 further performs the following driving control.

[0117] That is, the driving assistance device 1 executes steering assistance control and driving assistance control to guide the host vehicle 100 to the center position of the driving lane RL and drive while maintaining the lane center position. The steering assistance control at this time is performed in the area indicated by symbol F from a predetermined position after a predetermined time has elapsed from symbol D in Fig. 2. The vector of the traveling direction of the host vehicle 100 while driving in this area is indicated by arrow symbol S5 in Fig. 2.

[0118] When the vehicle 100 reaches the position indicated by the symbol F in FIG. 2, the line along the longitudinal direction of the vehicle 100 (the line along the arrow symbol S6 at this point (position F)) and the lane marking L2 become parallel again. The vector of the traveling direction of the vehicle 100 at this time is indicated by the arrow symbol S6 in FIG. 2. Here, the steering control performed from position D to position F is referred to as the "third stage control processing."

[0119] In this way, when the host vehicle 100 reaches a state where it is traveling while maintaining a central position in the driving lane RL, the lane departure suppression control by the driving assistance device 1 is completed.

[0120] In the above explanation using Figure 2, we have assumed a case where the vehicle deviates into the oncoming lane while traveling in the left lane on a road with alternating traffic and one lane in each direction, but the situation in which lane departure prevention control is performed is not limited to this situation.

[0121] For example, on a road with two lanes in each direction (four lanes in each direction), when the vehicle is traveling in the left lane of the two lanes in each direction as the driving lane, the control can be applied in exactly the same way even when the vehicle is about to deviate into the adjacent lane on the right (the passing lane). Furthermore, there are many other similar examples, such as a case where departure into the left lane is suppressed while traveling in the right lane of a road with two lanes in each direction, or a case where departure suppression control is performed to the right lane or the left lane while traveling in the center lane of a road with three lanes in each direction. The same applies to the emergency departure suppression control and driver abnormality response control described below, and are not limited to the examples described.

[0122] Next, Fig. 3 is a diagram illustrating an example of the operation of emergency departure suppression control performed in the driving assistance device 1 of this embodiment (response to an oncoming vehicle in the first emergency departure suppression control). The emergency departure suppression control itself performed in the driving assistance device 1 of this embodiment is basically substantially the same as conventionally known lane departure suppression control. However, the difference is that the emergency departure suppression control is triggered to start when another vehicle, such as an oncoming vehicle or a following vehicle, is detected when the vehicle is about to depart from the lane. Note that the control parameters are set separately for the lane departure control and the emergency departure control, so the control amount differs for each control.

[0123] 2, the example shown in Fig. 3 assumes that the vehicle 100 is traveling in the area of ​​the left lane RL on a one-lane, alternating road R. Therefore, the same reference numerals as in Fig. 2 are used for each symbol (the vehicle 100, the road R, the lanes RL and RR, the dividing lines L1, L2, and L3, etc.).

[0124] In this case, the host vehicle 100 is traveling in the left lane RL as its own lane (host lane). Also, it is shown that an oncoming vehicle 110 is present in the right lane RR, traveling in the opposite direction to the host vehicle 100. It is assumed that the driving assistance device 1 mounted on the host vehicle 100 is set to an ON state in which both the lane departure prevention control and the emergency departure prevention control of the steering assistance control are activated.

[0125] Also, here, the control when lane departure prevention control or emergency departure prevention control is on is referred to as first emergency departure prevention control. The example in Fig. 3 is an example of oncoming vehicle detection in first emergency departure prevention control. Also, in order to explain the action of first emergency departure prevention control (control when lane departure prevention control or emergency departure prevention control is on), the explanation of Fig. 3 does not take into account the on / off states of other controls, or the intervention and influence of those other controls.

[0126] In this situation, the driving assistance device 1 of the vehicle 100 recognizes the dividing lines (L1, L2) on both sides of the vehicle's lane, sets the lane RL between the recognized dividing lines (L1, L2) as the driving lane in which the vehicle 100 should travel, and sets, for example, the center position of the lane as the target driving position of the vehicle 100 within the set driving lane RL (similar to the situation in Figure 2).

[0127] Here, similar to the situation in Fig. 2, consider a case where the host vehicle 100 is about to deviate from the driving lane RL into the adjacent lane RR (the oncoming lane in the example of Fig. 3). The situation of the host vehicle 100 at this time is that the host vehicle 100 is located at the position indicated by the symbol A in Fig. 3 and is in the attitude shown in Fig. 3.

[0128] 3, the host vehicle 100 is in a situation where a line along the front-to-rear direction of the host vehicle 100 and along the vector (arrow symbol S1) of the traveling direction of the host vehicle 100 at this time (position A) is inclined at a predetermined angle with respect to the dividing lines L1 and L2 on both sides of the traveling lane RL of the host vehicle 100. Therefore, if the host vehicle 100 continues to travel along the arrow symbol S1 of the vector of the traveling direction, the host vehicle 100 is expected to cross over the dividing line L2 and then deviate into the adjacent lane RR (oncoming lane) (determined by the lane departure determination unit 22g).

[0129] Furthermore, at this time, an oncoming vehicle 110 is present in the oncoming lane RR on the forward extension of the line (line along arrow symbol S1) along the fore-and-aft direction of the vehicle 100, and is traveling in the direction along arrow symbol S10 in Figure 3, and the driving assistance device 1 of the vehicle 100 has detected the oncoming vehicle 110 using, for example, a camera unit 21, etc.

[0130] 3, the driving assistance device 1 of the host vehicle 100 has both the lane departure prevention control and the emergency departure prevention control turned on, so it detects that the host vehicle 100 is about to depart from the driving lane RL and starts the lane departure prevention control. At the same time, it detects an oncoming vehicle 110 and starts the emergency departure prevention control.

[0131] In such a case, first, an oncoming vehicle 110 is detected, emergency departure suppression control is initiated, and a warning display 200 (see FIG. 3) is displayed to alert other vehicles, such as oncoming vehicles, to be on guard. This warning display 200 is, for example, a visual display on a display panel or the like, or an audible display using a speaker or the like.

[0132] Thereafter, when the vehicle 100 and the oncoming vehicle 110 pass each other and the oncoming vehicle 110 moves away from the surroundings of the vehicle 100 and no longer exists, and when there is no oncoming vehicle following the oncoming vehicle 110 (when no following oncoming vehicle is detected), the emergency departure suppression control currently being executed is switched to lane departure suppression control.

[0133] At the same time, the warning display 200 based on the emergency departure prevention control is switched to a predetermined status display 201 indicating that lane departure prevention control is being executed, and the status display 201 continues to be displayed. The subsequent operations are exactly the same as those described above with reference to FIG. 2.

[0134] In this way, the timing for switching from emergency departure suppression control accompanied by warning display 200 to LPD control accompanied by status display 201 is, for example, the point at which, after emergency departure suppression control has been initiated, the oncoming vehicle 110 detected as the trigger for starting the emergency departure suppression control and any following oncoming vehicles, etc., no longer exist.

[0135] It is possible that after the host vehicle 100 passes the oncoming vehicle 110 detected as a trigger for the emergency departure prevention control, another oncoming vehicle (for example, a following oncoming vehicle following the oncoming vehicle that was detected) may be present. In this case, the driving assistance device 1 will further perform an oncoming vehicle detection determination and continue or resume the warning. However, once the host vehicle 100 is traveling at position B, the host vehicle 100 is traveling along the lane marking L2 without crossing the lane marking L2. In this state, as described above, a portion of the host vehicle 100 may extend into the area of ​​the adjacent oncoming lane RR. However, at this point, the host vehicle 100 is still performing the normal lane departure prevention control that has been switched from the emergency departure prevention control, and the host vehicle 100 is therefore controlled to travel away from the oncoming lane. Therefore, it can be said that the risk of a collision with an oncoming vehicle has been almost completely avoided at this point. Even if the vehicle 100 cancels the warning display 200 when the first oncoming vehicle 110 that was detected no longer exists, the driver will not feel uncomfortable.

[0136] The example in Figure 3 above is based on the assumption that an oncoming vehicle is detected in the oncoming lane when the vehicle is traveling in the left lane on a road with alternating traffic and one lane in each direction, but the situation is not limited to this.

[0137] For example, FIG. 4 is a diagram illustrating another example of the operation of the emergency departure suppression control performed in the driving assistance device of this embodiment (first emergency departure suppression control for a following vehicle).

[0138] Figure 4 illustrates a situation where a vehicle is traveling in the left lane of a two-lane road (four lanes in both directions) and is about to deviate into the adjacent lane on the right (passing lane). Note that Figure 4 only shows two lanes in each direction of the four-lane road.

[0139] In another example shown in FIG. 4, it is also assumed that both the lane departure suppression control and the emergency departure suppression control are in the on state (first emergency departure suppression control).

[0140] As shown in Figure 4, on a road with two lanes on each side (four lanes in both directions), when the vehicle is traveling in the left lane RL1 of the two lanes on each side as the driving lane, the vehicle is about to deviate into the adjacent lane on the right (passing lane) RL2, and there is a following vehicle 111 approaching the vehicle 100 from behind along the arrow S11 of the vector in the direction of travel, with the vehicle 100 using the adjacent right lane RL2 as the driving lane, the same method can be applied.

[0141] Next, FIG. 5 is a diagram illustrating another example of the operation of the emergency departure suppression control performed in the driving assistance device of this embodiment (second emergency departure suppression control in response to an oncoming vehicle).

[0142] 5, similar to the example in Fig. 3, it is assumed that the vehicle 100 is traveling in the area in the left lane RL on a one-lane, alternating road R. Therefore, the same reference numerals as those in Fig. 2 and Fig. 3 are used.

[0143] In this case, the host vehicle 100 is traveling in the left lane RL as its own lane (host lane), and an oncoming vehicle 110 is present in the right lane RR, which is the same as the situation in Fig. 3. In this example, the driving assistance device 1 mounted on the host vehicle 100 is set to an OFF state for the lane departure prevention control among the steering assistance controls, and is set to an ON state in which only the emergency departure prevention control is activated.

[0144] Here, the control when lane departure prevention control is off and emergency departure prevention control is on is referred to as second emergency departure prevention control. The example in Fig. 5 is an example of oncoming vehicle detection in second emergency departure prevention control. In addition, the explanation of Fig. 5 does not take into account the on / off states of other controls, or the intervention and influence of those other controls, in order to explain the operation of second emergency departure prevention control (control when lane departure prevention control is off and emergency departure prevention control is on).

[0145] In this situation, the driving assistance device 1 of the host vehicle 100 recognizes the lane markings (L1, L2) on both sides of the host vehicle's lane, sets the lane RL between the recognized lane markings (L1, L2) as the lane in which the host vehicle 100 should travel, and sets, for example, the lane center position as the target travel position of the host vehicle 100 within the set lane RL (similar to the explanation of FIGS. 2 and 3). Now, as in the case of FIGS. 2 and 3, consider a case in which the host vehicle 100 is about to deviate from the travel lane RL into an adjacent lane RR (an oncoming lane in the example of FIG. 5). The situation of the host vehicle 100 at this time is assumed to be that the host vehicle 100 is located at the position indicated by symbol A in FIG. 5 and is in the attitude shown in FIG. 5.

[0146] 5, the host vehicle 100 is in a situation where a line along the front-to-rear direction of the host vehicle 100 and along the vector (arrow symbol S1) of the traveling direction of the host vehicle 100 at this time (position A) is inclined at a predetermined angle with respect to the dividing lines L1 and L2 on both sides of the traveling lane RL of the host vehicle 100. Therefore, if the host vehicle 100 continues to travel along the arrow symbol S1 of the traveling direction vector, the host vehicle 100 is expected to cross over the dividing line L2 and then deviate into the adjacent lane RR (oncoming lane) (determined by the lane departure determination unit 22g).

[0147] However, in this case, the driving assistance device 1 has the lane departure prevention control turned off, so that the lane departure prevention control is not started even if the lane departure determination is made as described above. In this case, the driver operates the steering wheel by his / her own will to prevent the vehicle from leaving the lane.

[0148] Meanwhile, at this time, an oncoming vehicle 110 is present in the oncoming lane RR on the forward extension of a line (a line along arrow S1) along the longitudinal direction of the host vehicle 100, and is traveling in the direction along arrow S10 in Fig. 5. The driving assistance device 1 of the host vehicle 100 detects the oncoming vehicle 110 using, for example, the camera unit 21. Then, the detection of the oncoming vehicle 110 triggers the driving assistance device 1 to start emergency departure suppression control.

[0149] When an oncoming vehicle 110 is detected and emergency departure prevention control is initiated in this manner, a warning display 200 (see FIG. 5) is first displayed to alert other vehicles, such as oncoming vehicles, to be on their guard. This warning display 200 is, for example, a visual display on a display panel or the like, or an audible display using a speaker or the like. This warning display 200 continues to be displayed until emergency departure prevention control is completed.

[0150] Here, the emergency departure suppression control is triggered by the detection of an oncoming vehicle 110, and predetermined steering assist control is performed along with the warning display 200. As a result, the host vehicle 100 travels from position A in FIG. 5 to positions B and C and then to position D. At position D in FIG. 5, the host vehicle 100 travels in a state where the line extending along the longitudinal direction (the line extending along the arrow S4) and the lane marking L2 are parallel, and the host vehicle 100 is traveling while maintaining a lane edge position within the travel lane. Thereafter, the host vehicle continues traveling along the lane marking L2 while maintaining this state for a predetermined period of time. During this time, if the oncoming vehicle 110 that triggered the start of the emergency departure prevention control passes by the host vehicle 100 and moves away from the surroundings of the host vehicle 100, and if there is no oncoming vehicle following the oncoming vehicle 110 (if no following oncoming vehicle is detected), the emergency departure prevention control being executed ends when the host vehicle 100 becomes parallel to the dividing line L2 and travels within the travel lane while maintaining the lane edge position. At this time, the warning display 200 based on the emergency departure prevention control also ends.

[0151] Next, the operation of the emergency departure suppression control performed in the driving assistance device of this embodiment will be described below with reference to FIGS.

[0152] Fig. 6 is a flowchart showing details of lane departure suppression control and emergency departure suppression control performed in the driving assistance device of this embodiment. Fig. 7 is a flowchart of a subroutine of the first emergency departure suppression control (processing of step S13) in Fig. 6. Fig. 8 is a flowchart of a subroutine of the second emergency departure suppression control (processing of step S16) in Fig. 6.

[0153] First, in step S11 of Fig. 6, the cruise control unit 22 checks whether the lane departure prevention control is set to ON. If it is confirmed that the lane departure prevention control is set to ON, the process proceeds to the next step S12. If it is confirmed that the lane departure prevention control is set to OFF, the process proceeds to step S15.

[0154] In step S12, the cruise control unit 22 checks whether the emergency departure prevention control is set to ON. If it is confirmed that the emergency departure prevention control is set to ON, the process proceeds to the next step S13. If it is confirmed that the emergency departure prevention control is set to OFF, the process proceeds to step S14.

[0155] In step S13, since it has been confirmed that both the lane departure prevention control and the emergency departure prevention control are in the ON state, the cruise control unit 22 executes the first emergency departure prevention control. After completing this control process, the process then returns to the original main sequence (not shown).

[0156] In step S14, since it has been confirmed that the lane departure prevention control is on and the emergency departure prevention control is off, the cruise control unit 22 executes normal lane departure prevention control (see FIG. 2). After completing this control process, the process then returns to the original main sequence (not shown).

[0157] In step S15, the cruise control unit 22 checks whether the emergency departure suppression control is set to the ON state. If it is confirmed that the emergency departure suppression control is set to the ON state, the process proceeds to the next step S16. If it is confirmed that the emergency departure suppression control is set to the OFF state, both the lane departure suppression control and the emergency departure suppression control are in the OFF state. Therefore, in this case, the process returns to the original main sequence (not shown).

[0158] In step S16, since it has been confirmed that the lane departure prevention control is OFF and the emergency departure prevention control is ON, the cruise control unit 22 executes the second emergency departure prevention control. After completing this control process, the process then returns to the original main sequence (not shown).

[0159] Next, the processing of step S13 in FIG. 6, ie, the first emergency deviation suppression control, will be described below using a subroutine in FIG.

[0160] First, in step S21 of Fig. 7, the cruise control unit 22 (lane departure determination unit 22g) determines whether or not the host vehicle 100 is likely to deviate from the lane in which it is traveling. If it is determined that the host vehicle 100 is likely to deviate from the lane, the process proceeds to the next step S22. Note that this determination process is repeated until it is determined that the host vehicle 100 is likely to deviate from the lane.

[0161] In step S22, the cruise control unit 22 (surrounding situation determination unit 22a) checks for the presence of other vehicles, such as an oncoming vehicle or a following vehicle, traveling around the host vehicle 100. If an oncoming vehicle or a following vehicle is detected, the process proceeds to the next step S23. If no oncoming vehicle or a following vehicle is detected, the process proceeds to step S24.

[0162] Then, in step S24, the cruise control unit 22 executes normal lane departure suppression control (see FIG. 2). After the control process is completed, the process returns to the original main sequence (not shown).

[0163] In step S23, the cruise control unit 22 starts emergency departure suppression control.

[0164] Next, in step S25, the cruise control unit 22 displays a predetermined warning display 200 and simultaneously executes predetermined steering control in accordance with emergency departure suppression control. In this processing step, the host vehicle 100 is moved from position A to position B in Fig. 3 so that the line along the fore-and-aft direction of the host vehicle is parallel to the lane marking L2, and further, a control process is performed to maintain this state while the host vehicle 100 travels for a predetermined period of time.

[0165] Next, in step S26, the cruise control unit 22 again checks for the presence of other vehicles, such as oncoming vehicles or following vehicles, traveling around the host vehicle 100. If an oncoming vehicle or following vehicle is detected, the process returns to step S25 described above. If no oncoming vehicle or following vehicle is detected, the process proceeds to the next step, S27.

[0166] In step S27, the cruise control unit 22 ends the emergency departure suppression control.

[0167] Subsequently, in step S28, the cruise control unit 22 switches the control from emergency departure prevention control to lane departure prevention control, and simultaneously switches the display from the warning display 200 to the status display 201.

[0168] Next, in step S29, the cruise control unit 22 executes steering control in accordance with the lane departure prevention control from the point in time when the emergency departure prevention control described above ends. The steering control executed here is a control that takes over the predetermined steering control in accordance with the emergency departure prevention control that was started in the processing of step S25 described above, and similar steering control is executed continuously.

[0169] Then, in step S30, the cruise control unit 22 checks whether the host vehicle 100 is now traveling while maintaining a center position in the traveling lane. If it is not confirmed that the host vehicle 100 is traveling while maintaining a center position in the traveling lane, the process returns to step S29. If it is confirmed that the host vehicle 100 is traveling while maintaining a center position in the traveling lane, the process ends the series of controls and returns to the original main sequence (not shown).

[0170] Next, the processing of step S16 in FIG. 6, ie, the second emergency departure suppression control, will be described below using a subroutine in FIG.

[0171] First, in step S31 of Fig. 8, the cruise control unit 22 (lane departure determination unit 22g) determines whether or not the host vehicle 100 is likely to deviate from the lane in which it is traveling. This processing step is the same as step S21 of Fig. 7. If it is determined that the host vehicle 100 is likely to deviate from the lane, the process proceeds to the next step S32. Note that this determination process is repeated until it is determined that the host vehicle 100 is likely to deviate from the lane.

[0172] In step S32, the cruise control unit 22 (surrounding condition determination unit 22a) checks for the presence of other vehicles, such as an oncoming vehicle or a following vehicle, traveling around the host vehicle 100. This processing step is the same as step S22 in FIG. 7. If another vehicle, such as an oncoming vehicle or a following vehicle, is detected, the process proceeds to the next step, S33. If another vehicle, such as an oncoming vehicle or a following vehicle, is not detected, the process returns to the original main sequence (not shown).

[0173] In step S33, the cruise control unit 22 starts emergency departure suppression control.

[0174] Next, in step S34, the cruise control unit 22 displays a predetermined warning display 200 and simultaneously executes steering control according to emergency departure suppression control. In this processing step, the host vehicle 100 is moved from position A to position D in Fig. 5 so that the line along the fore-and-aft direction of the host vehicle and the lane marking L2 are parallel, and further, a control process is performed to maintain this state while the host vehicle 100 travels for a predetermined time.

[0175] In step S35, the cruise control unit 22 again checks for the presence of other vehicles, such as oncoming vehicles or following vehicles, traveling around the host vehicle 100. If an oncoming vehicle or following vehicle is detected, the process proceeds to step S38. If an oncoming vehicle or following vehicle is not detected, the process proceeds to the next step, S36.

[0176] In step S36, the cruise control unit 22 checks whether the host vehicle 100 has transitioned to a state of traveling along the edge of the traveling lane. If the host vehicle 100 is confirmed to be traveling along the edge of the traveling lane, the process proceeds to the next step S37. If the host vehicle 100 is not confirmed to be traveling along the edge of the traveling lane, the process returns to the process of step S34.

[0177] Next, in step S37, the cruise control unit 22 ends the emergency departure prevention control. At this point, the warning display 200 based on the emergency departure prevention control also ends. After that, the process returns to the original processing sequence (RETURN).

[0178] On the other hand, if the presence of another vehicle, such as an oncoming vehicle or a following vehicle, traveling around the host vehicle 100 is confirmed again in the processing of step S35 and the process proceeds to the processing of step S38, the cruise control unit 22 checks in this step S38 whether the host vehicle 100 has transitioned to a state of traveling along the lane edge of the traveling lane. If the state of traveling along the lane edge is confirmed here, the process proceeds to the next step S39. If traveling along the lane edge is not confirmed, the process returns to the processing of the above-mentioned step S34.

[0179] Next, in step S39, the cruise control unit 22 performs cruise control to keep the host vehicle 100 in the center position of the travel lane and continue traveling.

[0180] Then, in step S40, the cruise control unit 22 checks whether the host vehicle 100 is now traveling while maintaining a center position in the traveling lane. If it is not confirmed that the host vehicle 100 is traveling while maintaining a center position in the traveling lane, the process returns to step S39. If it is confirmed that the host vehicle 100 is traveling while maintaining a center position in the traveling lane, the process ends the series of controls and returns to the original main sequence (not shown).

[0181] As described above, according to the driving assistance device 1 of the above embodiment, when the results of the determination by the surrounding situation determination unit 22a and the steering state determination unit 22b indicate that the host vehicle 100 is in a state where normal driving cannot be maintained (for example, when the host vehicle 100 is about to deviate from the lane in which it is traveling), the driving control unit 22 executes lane departure suppression control, which is driving control for emergency response, if a predetermined setting is made (if the function is in an on-state). In this case, if another vehicle, such as an oncoming vehicle or a following vehicle, is present in an adjacent lane to the host vehicle 100, the driving control unit 22 executes emergency departure suppression control.

[0182] When both lane departure prevention control and emergency departure prevention control are selected to be in operation, the steering assist control unit 22d switches from emergency departure prevention control to lane departure prevention control when the vehicle 100 is brought into a driving state in which it follows the dividing line of the set driving lane without crossing the dividing line, and executes first emergency departure prevention control, which performs driving control to return the driving position of the vehicle from a position where it does not cross the dividing line of the set driving lane to the target driving position.

[0183] In addition, when the steering assist control unit 22d selects the lane departure prevention control to be in an inactive state and the emergency departure prevention control to be in an active state, it causes the vehicle 100 to travel along the dividing line of the set driving lane without crossing the dividing line, and then, when the vehicle 100 travels along the lane edge within the set driving lane, it switches from the emergency departure prevention control to the lane departure prevention control and executes second emergency departure prevention control, which performs driving control to return the vehicle's travel position from a position along the lane edge within the set driving lane to the target travel position.

[0184] The timing at which the steering assist control unit 22d switches from emergency departure prevention control (emergency departure prevention control) to lane departure prevention control (LPD control) is the timing at which the vector of the vehicle 100's direction of travel and the lane markings of the driving lane become approximately parallel.

[0185] With this configuration, the driving assistance device 1 of this embodiment provides emergency departure suppression control when another vehicle, such as an oncoming vehicle or a following vehicle, is recognized in an adjacent lane to the vehicle.The emergency departure suppression control is a first emergency departure suppression control when both the lane departure suppression control and the emergency departure suppression control are turned on, and a second emergency departure suppression control when the LDK control is turned off and the emergency departure suppression control is turned on.Each control is performed in substantially the same way as the normal lane departure suppression control, but the warning display that continues to be displayed during the normal emergency departure suppression control is canceled at a predetermined timing.

[0186] Therefore, when steering assist control is performed by combining lane departure prevention control and emergency departure prevention control, by appropriately changing the timing of switching the control processing to be executed according to the on / off setting of each control, more natural and smooth steering assist control can always be performed without causing the driver any inconvenience or discomfort.

[0187] The driving assistance device 1 of this embodiment has a steering state determination function that detects a state in which the driver is gripping the steering wheel while the vehicle is traveling (hereinafter referred to as a steering state), and determines the steering state of the driver. This steering state determination function is realized by a steering state recognition unit (steering wheel touch sensor 34, steering torque sensor 35), a steering state determination unit 22b of the driving control unit 22, etc.

[0188] The steering state recognition unit (steering wheel touch sensor 34, steering torque sensor 35) constantly monitors the driver's grip on the steering wheel (steering state) while the vehicle is running, and the steering state determination unit 22b determines the steering state based on the output signal from the steering state recognition unit (34, 35).

[0189] For example, if the situation where the steering state is not detected continues for a predetermined time (e.g., 15 seconds) (or while driving a predetermined distance), a predetermined warning display (visual warning display, auditory warning display, etc.) is generated, and if the state where the hands are taken off the steering wheel continues for a predetermined time (e.g., 50 seconds) (or while driving a predetermined distance), control is performed to cancel the steering assist control that is currently being executed.

[0190] At this time, the driving assistance device 1 determines that some abnormality has occurred that makes it difficult for the driver to perform driving operations (specifically, for example, a malfunction of the vehicle, or a decrease in consciousness due to the driver's sudden illness or drowsiness at the wheel, etc.), and executes so-called driver abnormality response control.

[0191] Here, the basic operation of the driver abnormality response control will be briefly explained below with reference to Fig. 9. Fig. 9 is a diagram for explaining the outline of the operation of the driver abnormality response control performed in the driving assistance device of this embodiment. The basic operation of the driver abnormality response control itself performed in the driving assistance device 1 of this embodiment is substantially the same as that of conventionally known control. The driver abnormality response control performed in the driving assistance device 1 of this embodiment has an innovative control for determining the steering state compared to conventional control (described in detail later).

[0192] The example shown in Figure 9 assumes that vehicle 100 is traveling on a main road R, such as a highway, which has two lanes on each side and a central divider, and that vehicle 100 is traveling in the area within the right lane RL2 (passing lane) of the two lanes on each side.

[0193] Here, road R has a left lane RL1, a right lane RL1, and a left shoulder strip N as seen from the driver of vehicle 100. The left lane RL1 is the area sandwiched between the left shoulder marking L1 and the center marking L2. The right lane RL2 is the area sandwiched between the center marking L2 and the right shoulder marking L3. The left shoulder strip N is the area sandwiched between the left shoulder marking L1 and a guardrail or sidewall W (hereinafter simply referred to as sidewall W). It is assumed that a center median strip C1 is provided outside the right shoulder marking L3 (to the right as seen from the driver of vehicle 100), separated by, for example, a guardrail (not shown).

[0194] In this case, as described above, the host vehicle 100 is traveling in the right lane RL2 as its own lane. The driving assistance device 1 mounted on the host vehicle 100 is assumed to be running while executing various steering assistance controls (lane keeping assistance control, lane departure prevention control, emergency departure prevention control, etc.).

[0195] In this situation, the driving assistance device 1 of the vehicle 100 determines that the state where the steering state is not detected by the steering state determination function continues for a predetermined time, and that the predetermined time has passed without detecting the steering state even if a predetermined warning display (visual warning display, audible warning display, etc.) is generated. In such a case, the driving assistance device 1 determines that an abnormality or the like has occurred in the driver (abnormality detection).

[0196] In this case, first, the driving support device 1 issues a predetermined notification to the driver prior to starting the driver abnormality response control.

[0197] Here, the notification to the driver may be by a visual warning display, an audible warning display, etc. For example, the visual warning display may be, for example, lighting up a lamp of a predetermined operation switch in an instrument panel visible from the driver's seat, or a warning display urging the driver to maintain steering or a warning display that a driver abnormality response control will be started, using a display panel, etc. Furthermore, the audible warning display may be, for example, a warning urging the driver to maintain steering or a warning display that a driver abnormality response control will be started, using a voice announcement, etc.

[0198] After the notification is issued, if the driver does not respond in any way to the notification (for example, by performing a steering operation or by canceling the start of driver abnormality response control), the driving assistance device 1 will cancel the steering assistance control that is currently being executed and at the same time start executing driver abnormality response control.

[0199] In the above explanation, it is stated that the notification is "notified to the driver," but the target of the notification is not limited to the driver, and may include, for example, passengers in the vehicle 100, or "notification to drivers of other vehicles outside the vehicle" of the vehicle 100.

[0200] The "notification to passengers" may be by a visual warning display, an audible warning display, or the like, similar to the "notification to the driver" described above.

[0201] In addition, "notifying drivers of other vehicles outside the vehicle" may be, for example, flashing hazard lights, flashing blinkers when changing lanes, etc. Also, various behaviors that notify the outside of the behavior of the vehicle 100 without the driver's operation, such as turning on brake lights when braking control is being performed, are realized.

[0202] In this way, the driver abnormality response control in the driving assistance device 1 is a function that is activated by detecting an abnormality in the driver, etc. In this case, the driver abnormality is determined based on whether the steering has not been maintained for a predetermined time or more, or whether the vehicle has traveled a predetermined distance or more, etc.

[0203] In Fig. 9, it is assumed that an abnormality in the driver or the like is detected when the host vehicle 100 is at the position indicated by the symbol A. Here, when the driver abnormality response control is executed, the driving assistance device 1 first controls the host vehicle 100 to retreat from the position indicated by the symbol A in Fig. 9 to an area such as the left shoulder of the road, and then to stop the vehicle at a predetermined position, for example, the position indicated by the symbol F in Fig. 9. In more detail, (1) When the vehicle 100 is at position A in FIG. 9, an abnormality in the driver or the like is detected. (2) The vehicle 100 is allowed to travel in the current lane in this state. (a) The hazard lights are flashed to alert the outside. (b) With a predetermined speed (for example, 50 km / h) as the upper limit, speed adjustment (deceleration control by engine control and braking control) is performed, and steering control required according to the road shape is performed as appropriate to maintain driving within the same lane. The deceleration control at this time is deceleration control that does not suppress acceleration, that is, braking control in a state where input by the accelerator is allowed. Thereafter, (3) The host vehicle is caused to change lanes as needed to move to the shoulder. For example, as shown in FIG. 9, when the host vehicle is traveling in a two-lane roadway with a center lane, the host vehicle is caused to change lanes to the left lane RL1 by predetermined steering control. This moves the host vehicle 100 from position B in FIG. 9 to position C, then to position D. When the host vehicle changes lanes, the hazard lights are turned off and the left turn signal is turned on. (4) When the host vehicle 100 moves to position D in Figure 9 and is able to travel within the left lane RL1, the left turn signal is turned off and the hazard lights are turned on again to maintain travel within the left lane RL1. (5) The vehicle is decelerated to a predetermined speed (for example, 10 km / h) by performing the braking control required to pull the vehicle over to the shoulder. This deceleration control is a deceleration control that suppresses acceleration, i.e., braking control in a state where accelerator input is not permitted. (6) Steering control is performed to move the vehicle toward the shoulder. This steering control is the same as that for changing lanes. That is, the hazard lights are turned off, the left turn signal is turned on, and predetermined steering control is performed from the left lane RL1 toward the area of ​​shoulder strip N. This moves the vehicle 100 from position D in FIG. 9 to position E and into the area of ​​shoulder strip N. (7) When the host vehicle 100 is sure to be traveling within the shoulder strip N, the left blinker is turned off and the hazard lights are turned on again. Then, while the host vehicle 100 is traveling within the shoulder strip N, braking control is performed to further decelerate the host vehicle 100 and bring the host vehicle 100 to a stop at a position (position F in FIG. 9 ) where a predetermined distance is maintained between the host vehicle 100 and the side wall W or the like. The deceleration control at this time is also deceleration control that suppresses acceleration. (8) After the vehicle 100 stops at position F, the hazard lights will be flashed and external alerts such as the horn will be sounded until the driver abnormality response control is released according to a predetermined procedure.

[0204] Next, the operation of the driver abnormality response control performed in the driving support device of this embodiment will be described below with reference to FIGS. Fig. 10 is a flowchart illustrating the start timing of the driver abnormality response control in the driving support device of this embodiment. Fig. 11 is a flowchart illustrating the driver abnormality response control (processing of step S47) of Fig. 10.

[0205] In the driving assistance device 1 of this embodiment mounted on the vehicle 100, when the driving control unit 22 is activated and normal driving control including the set steering assistance control is started, first, in step S40 of Figure 10, the driving control unit 22 starts counting using the ``non-steering time counter'' among the internal counters not shown.

[0206] Here, the non-maintained steering time refers to the time during which the driver keeps his / her hands off the steering wheel (time during which the steering wheel is not in a maintained state). The non-maintained steering time counter (not shown) counts up the duration during which the maintained steering state determination unit 22b determines that the steering wheel is in a non-maintained state based on the output signal from the maintained steering state recognition unit (34, 35).

[0207] In other words, the non-maintained steering time counter measures the time during which no output signal is generated from the maintained steering state recognition unit (34, 35). The driving assistance device 1 of this embodiment continuously counts the non-maintained steering time while the cruise control unit 22 is activated and the host vehicle 100 is traveling.

[0208] Here, the non-maintained steering state refers to a state in which the driver of the vehicle 100 does not interfere with the steering device (including, for example, touching or gripping the steering wheel) for a predetermined time period (or while the vehicle travels a predetermined distance), and this is not detected by the maintained steering state recognition unit (steering wheel touch sensor 34 or steering torque sensor 35). Then, as will be described later, when such a non-maintained steering state continues for a predetermined time period, the maintained steering state determination unit 22b determines that the vehicle is in a non-maintained steering state, and outputs a determination result that the driver of the vehicle 100 is in a state in which he or she cannot maintain normal driving.

[0209] When the host vehicle 100 is traveling in this state, in step S41 of Fig. 10, the cruise control unit 22 checks whether or not it has detected an output signal (ON signal) from the steering wheel touch sensor 34 of the steering wheel holding state recognition unit. If an ON signal is detected from the steering wheel touch sensor 34, it is determined that the vehicle is in a steering wheel holding state, and the process proceeds to step S50. If an ON signal is not detected from the steering wheel touch sensor 34, it is determined that the vehicle is in a steering wheel non-holding state, and the process proceeds to the next step, S42.

[0210] In step S42, the cruise control unit 22 checks whether the steering torque value detected by the steering torque sensor 35 of the steering state recognition unit is equal to or greater than a predetermined threshold. If it is confirmed that the steering torque value of the steering torque sensor 35 is equal to or greater than the predetermined threshold, it is determined that the vehicle is in a steering state, and the process proceeds to step S50. If it is confirmed that the steering torque value of the steering torque sensor 35 is less than the predetermined threshold, it is determined that the vehicle is in a non-steering state, and the process proceeds to the next step, S43.

[0211] When it is confirmed that the steering is in a fixed state in the processing of steps S41 and S42 described above and the processing proceeds to step S50, in this step S50 the driving control unit 22 resets the non-fixed steering time of the non-fixed steering time counter and returns to the processing of step S41 described above.

[0212] Next, in step S43, the cruise control unit 22 counts up the non-maintained steering time of the non-maintained steering time counter.

[0213] Next, in step S44, the cruise control unit 22 checks whether the non-maintained steering time counted in the non-maintained steering time counter has exceeded a predetermined threshold (for example, 15 seconds). If it is confirmed that the non-maintained steering time has exceeded the predetermined threshold, the process proceeds to the next step S45. If the non-maintained steering time has not exceeded the predetermined threshold, the process returns to step S41.

[0214] In step S45, the cruise control unit 22 drives the alarm device 38 to display a predetermined warning. The warning displayed here is, for example, a visual or audible warning that notifies the driver that the steering is not being held.

[0215] Next, in step S46, the cruise control unit 22 again checks the output signal (ON signal) from the steering wheel touch sensor 34, similar to the processing in step S41 described above. If an ON signal from the steering wheel touch sensor 34 is confirmed, it is determined that the fixed steering state has been restored, and the process proceeds to step S51. If an ON signal from the steering wheel touch sensor 34 is not confirmed, it is determined that the non-fixed steering state continues, and the process proceeds to the next step, S47.

[0216] In step S47, the cruise control unit 22 again checks whether the steering torque value measured by the steering torque sensor 35 is equal to or greater than the predetermined threshold, as in the process of step S42 described above. If it is confirmed that the steering torque value measured by the steering torque sensor 35 is equal to or greater than the predetermined threshold, it is determined that the held steering state has been restored, and the process proceeds to step S51. If it is confirmed that the steering torque value measured by the steering torque sensor 35 is less than the predetermined threshold, it is determined that the non-held steering state continues, and the process proceeds to the next step, step S48.

[0217] When it is determined in the processes of steps S46 and S47 that the fixed steering state has been restored and the process proceeds to step S51, in step S51 the cruise control unit 22 cancels the ongoing warning display.

[0218] Subsequently, in step S52, the cruise control unit 22 resets the non-maintained steering time of the non-maintained steering time counter, and returns to the processing of step S41 described above.

[0219] Next, in step S48, the cruise control unit 22 checks whether a predetermined time (for example, 50 seconds) has elapsed since the warning display started in the processing of step S45 described above, while the non-maintained steering state is maintained and the warning display continues. If it is confirmed that the predetermined time has elapsed, the steering assist control being executed is canceled, and then the process proceeds to the next step S49. If the predetermined time has not elapsed, the process returns to the processing of step S45.

[0220] In step S49, the cruise control unit 22 executes driver abnormality response control (see FIG. 11 for details).

[0221] Note that the processing in steps S44 to S48 in Fig. 10 is described in a simplified manner. The processing in this period may be, for example, the following processing. That is, (1) When the steering time exceeds a predetermined threshold (e.g., 15 seconds), a visual warning is displayed. (2) If the driver remains in this state (the steering is not held and the visual warning display continues) without any cancellation operation (for example, holding the steering wheel or stepping on the accelerator) and a predetermined time (for example, 15 seconds) has elapsed, an auditory warning display (alarm sound) will be initiated in addition to the ongoing visual warning display. (3) If this state (the state in which the steering is not held and the visual and audible warning displays continue) is not confirmed and a predetermined time (e.g., 30 seconds) has elapsed, an even stronger emergency signal warning will be issued for a predetermined time (e.g., 5 seconds) or more. (4) Even in this state, if the driver does not perform a cancellation operation or the like, the steering assist control that is being executed is cancelled.

[0222] The above-described processing sequence is merely an example of the confirmation processing that is performed when the driver abnormality response control is started.

[0223] The process of step S48 in FIG. 10 that is started as described above, that is, the detailed sequence of the driver abnormality response control executed by the driving support device 1, will be described below with reference to a subroutine in FIG.

[0224] First, in step S61 of Fig. 11, the cruise control unit 22 performs control to maintain the host vehicle 100 traveling within the lane in which it is traveling, and also issues a warning to the outside. Specifically, for example, first, the hazard lights are flashed. At the same time, speed adjustment (deceleration control by engine control and braking control) is performed so that the host vehicle 100 reaches a predetermined upper speed limit (for example, 50 km / h). The deceleration control at this time is deceleration control that does not suppress acceleration, i.e., braking control in a state where accelerator input is permitted. In this way, the host vehicle 100 maintains traveling within the same lane.

[0225] Next, in step S62, the cruise control unit 22 performs a first steering state determination process. This first steering state determination process is performed by detecting the output of either the steering wheel touch sensor 34 or the steering torque sensor 35. Here, if it is determined that the first steering state determination is ON by detecting either an output signal (ON signal) from the steering wheel touch sensor 34 or confirming that the steering torque value from the steering torque sensor 35 is equal to or greater than a predetermined threshold, the execution of the driver abnormality response control is canceled and the process returns to the original process (RETURN). On the other hand, if it is determined that the output signal (ON signal) from the steering wheel touch sensor 34 is not detected and the steering torque value from the steering torque sensor 35 is less than the predetermined threshold, the process proceeds to the next step S63.

[0226] In step S63, the cruise control unit 22 checks whether a lane change is necessary to move the currently traveling vehicle to the shoulder. For example, if the vehicle is currently traveling in the right lane (passing lane) of a two-lane road, the vehicle must first change lanes to the left lane of the two-lane road in order to safely move the vehicle to the shoulder. In this case, the determination of whether a lane change is necessary is made by recognizing the driving environment, such as the condition of the road on which the vehicle is traveling (e.g., the number of lanes on the road) and the position of the lane on which the vehicle is traveling (e.g., which lane out of multiple lanes on one side).

[0227] If it is determined that a lane change is necessary, the process proceeds to step S81. If it is determined that a lane change is not necessary, the process proceeds to the next step S64.

[0228] When it is determined in the processing of step S63 that a lane change is necessary and the processing proceeds to step S81, the cruise control unit 22 executes predetermined lane change control in step S81. This lane change control is, for example, lane change control included in normal automatic driving control, such as stopping the flashing of the hazard lamps that are currently being executed, flashing the left turn signal, and performing steering control to the left lane. This lane change control is conventionally well-known control, and detailed description thereof will be omitted.

[0229] Next, in step S82, the cruise control unit 22 checks whether the lane change has been completed and the vehicle is traveling within the changed lane area. If it is confirmed that the lane change has been completed, the process proceeds to the next step S83. If the lane change has not been completed, the process returns to step S81.

[0230] Then, when the completion of the lane change is confirmed, in step S83, the cruise control unit 22 stops the blinking of the left turn signal, blinks the hazard lamps again, and continues cruise control to keep the vehicle in the destination lane. Then, the process returns to step S62.

[0231] On the other hand, if it is determined in the processing of step S63 that a lane change is not necessary and the processing proceeds to step S64, in this step S64, the cruise control unit 22 performs braking control to slow down the vehicle to a predetermined speed (for example, 10 km / h) so that the vehicle reaches a low speed required to safely pull over to the shoulder of the road. The deceleration control at this time is deceleration control that suppresses acceleration, that is, braking control in a state where accelerator input is not permitted.

[0232] Next, in step S65, the cruise control unit 22 performs a survival determination process to check whether the survival determination result is ON. The survival determination process is a process for checking whether any operation that can be used to determine whether the driver is alive has been performed by the driver (or a passenger). Examples of operations that can be used to determine whether the driver is alive include operating an operating member such as a switch or dial related to devices provided in the vehicle, such as an air conditioner switch, a window open / close switch, a mirror drive switch, or various switches on the steering wheel, or repeatedly depressing the brake pedal or accelerator pedal. However, in the survival determination process in this embodiment, only the output detection of the steering wheel touch sensor 34 is not taken into consideration.

[0233] If it is confirmed that the result of the survival determination process is ON, the process returns to the process of step S61 (speed control that maintains the driving lane and does not suppress acceleration). If it is confirmed that the result of the survival determination process is not ON (that is, if no operation is confirmed), the process proceeds to the next step S66.

[0234] In step S66, the cruise control unit 22 performs a second steering state determination process. This second steering state determination process is performed only by detecting the output of the steering torque sensor 35 (determining whether the steering torque value is equal to or greater than a threshold value), without taking into account the output detection of the steering wheel touch sensor 34. Here, if it is confirmed that the steering torque value from the steering torque sensor 35 is equal to or greater than a predetermined threshold value and it is determined that the second steering state determination is on, the execution of the driver abnormality response control is canceled and the process returns to the original process (return). On the other hand, if it is confirmed that the steering torque value from the steering torque sensor 35 is less than the predetermined threshold value, the process proceeds to the next step S67.

[0235] In step S67, the cruise control unit 22 checks whether the deceleration control executed in the process of step S64 has resulted in deceleration to a predetermined speed (for example, 10 km / h). If it is confirmed that the vehicle has been decelerated to the predetermined speed, the process proceeds to the next step, step S68. If the vehicle has not been decelerated to the predetermined speed, the process returns to step S64.

[0236] In step S68, the cruise control unit 22 performs cruise control to move the host vehicle to the shoulder and into the roadside zone. The cruise control in this case is substantially the same as the lane change control described above. For example, the cruise control unit 22 stops flashing the hazard lights, flashes the left turn signal, and steers the host vehicle into the roadside zone.

[0237] Next, in step S69, the cruise control unit 22 checks whether the host vehicle has been pulled into the roadside zone. If it is confirmed that the host vehicle has been pulled into the roadside zone, the process proceeds to the next step S70. If it is not confirmed that the host vehicle has been pulled into the roadside zone, the process returns to step S68.

[0238] In step S70, the cruise control unit 22 stops the blinking of the left turn signal and starts blinking the hazard lamps again.

[0239] Next, in step S71, the cruise control unit 22 performs braking control to stop the vehicle while maintaining the host vehicle traveling in the shoulder area. This braking control is also deceleration control to suppress acceleration.

[0240] Next, in step S72, the cruise control unit 22 checks whether the vehicle has stopped. If it is confirmed that the vehicle has stopped, the process proceeds to the next step S73. If it is not confirmed that the vehicle has stopped, the process returns to step S71.

[0241] Then, in step S73, the cruise control unit 22 checks whether an operation to release the driver's abnormality response control has been performed. Here, the cruise control unit 22 repeatedly checks for the control release operation, and if the control release operation is confirmed, the series of processes is terminated and the process returns to the original process (return).

[0242] The control release operation performed in the processing of step S73 described above is assumed to be a predetermined operation performed by, for example, the driver or a passenger. Here, the case where the driver performs the control release operation may be, for example, a case where the driver regains consciousness after stopping the vehicle even if the driver abnormality response control is caused by the driver's decreased consciousness. As described above, in the driving assistance device 1 of this embodiment, even if the host vehicle 100 is safely stopped within the shoulder N, the driving assistance device 1 does not immediately cancel the driver abnormality response control after the vehicle stops. Instead, in step S73, the driving assistance device 1 waits for a predetermined cancellation operation to be input. When the cancellation operation is performed, the driver abnormality response control is canceled. In this case, the cancel operation may be performed by the driver or a passenger. However, even after the vehicle has stopped, the driver may still be in a state where it is difficult to operate the vehicle. Furthermore, the passenger may not be familiar with operating the vehicle. In this case, the driver abnormality response control continues even after the host vehicle has safely stopped in a road area as described above.

[0243] For example, a case may be assumed in which an outside rescuer or the like opens the door of the vehicle 100 that has stopped. In this case, even if the vehicle 100 is stopped, it is assumed that the driver inside the vehicle is still in a state where it is difficult to drive. For example, such a driver may unconsciously touch the steering wheel or depress the accelerator pedal while unconscious, which may result in unintended vehicle behavior. Therefore, in order to suppress such unexpected behavior, the driver abnormality response control may be released, for example, by a configuration in which a rescuer or the like explicitly performs a release operation, or a function may be added to stop functions related to the vehicle's driving control after the vehicle has stopped.

[0244] Furthermore, in the embodiment described above, the criterion for determining whether the steering state is maintained is whether the unmaintained steering state has continued for a predetermined period of time, but this is not limited to this example. For example, the configuration may be such that it is recognized whether the vehicle has traveled a predetermined distance in an unmaintained steering state, and that distance traveled is used as the criterion for determination.

[0245] As described above, according to the above embodiment, the driving control unit 22 executes emergency response driving control, i.e., driver abnormality response control, when the judgment result by the surrounding situation judgment unit 22a or the steering state judgment unit 22b indicates that the driver of the vehicle 100 is in a state where he or she cannot maintain normal driving.

[0246] When this driver abnormality response control is executed, if the judgment result by the steering state judgment unit 22b is that the driver of the vehicle 100 is in a state where he or she cannot maintain normal driving, the driving assistance control being executed by the vehicle 100 is stopped, and after stopping the driving assistance control, a first steering state judgment process is performed in the steering state recognition unit to detect the output of either the steering wheel touch sensor 34 or the steering torque sensor 35, and if the output of either the steering wheel touch sensor 34 or the steering torque sensor 35 is detected, the driving assistance control is restored, while if the output of neither the steering wheel touch sensor 34 nor the steering torque sensor 35 is detected, a second steering state judgment process is performed in the steering state recognition unit to detect only the output value of the steering torque sensor, and the output value of the steering torque sensor is detected, and the driving assistance control is restored only if the output value of the steering torque sensor exceeds a predetermined threshold.

[0247] In the driving assistance device 1 of this embodiment configured as described above, when driver abnormality response control is being executed, the steering state is first determined by a first steering state determination process, and if the determination result shows that the non-steering state continues while driving for a predetermined time or a predetermined distance, the steering state is then determined by a second steering state determination process in the steering state recognition unit, which does not take into account the detection of the output of the steering wheel touch sensor 34.

[0248] Therefore, the driving support device 1 of this embodiment can suppress erroneous detection of abnormality determination for the driver, and can perform more reliable and highly accurate driver abnormality response control. Therefore, the driving support device 1 of this embodiment can contribute to improving the safety of vehicle driving.

[0249] In this embodiment, as an example of control to respond to an abnormality in the driver, a case where the vehicle is finally guided to a roadside area and stopped is shown, but this example is not limiting. For example, without performing steering control such as lane changes, it is also possible to gradually decelerate while issuing external alerts such as flashing hazard lights, and then stop the vehicle in the same lane as the current lane, and then in addition to flashing hazard lights, issue external alerts such as sounding the horn.

[0250] The present invention is not limited to the above-described embodiments, and various modifications and applications can be made without departing from the spirit and scope of the invention. Furthermore, the above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining the disclosed multiple constituent elements. For example, if the problem to be solved by the invention can be solved and the effects of the invention can be obtained even if some constituent elements are deleted from all the constituent elements shown in each of the above embodiments, the configuration from which these constituent elements are deleted can be extracted as the invention. Furthermore, constituent elements from different embodiments may be appropriately combined. The present invention is not limited by specific embodiments other than as limited by the appended claims. [Explanation of symbols]

[0251] 1...Driving assistance device 10...In-vehicle communication line 11...Locator unit 12...Map locator calculation unit 12a... Vehicle position estimation unit 12b...Map information acquisition section 13...Acceleration sensor 14...Wheel speed sensor 15...Gyro sensor 16...GNSS receiver 17...Road information receiver 18...High-precision road map database 19...Route information input section 20...Periphery monitoring unit (periphery situation recognition device) 20a...Surrounding situation recognition sensor 20b…Surrounding Environment Awareness Department 21...Camera unit (surrounding situation recognition device) 21a…Main camera 21b...Sub camera 21c...Image Processing Unit (IPU) 21d…Driving environment recognition section 22...Travel control unit (travel control device) 22a... Surrounding situation determination section 22b...Steering state determination unit 22c...Travel lane setting section 22d...Steering assist control unit 22e...Target travel position setting unit 22f...Escape judgment section 22g...Lane departure detection section 23...Engine control unit 24...Power steering control unit 25...Brake control unit 27...Throttle actuator 28...Electric power steering motor 29...Brake actuator 33...Mode switch 34... Steering wheel touch sensor (steering state recognition unit) 35...Steering torque sensor (steering state recognition unit) 36...Brake sensor 37...Accelerator sensor 38...Alarm device 100...Own vehicle 110...Oncoming vehicle 111...Following vehicle 200... Emergency deviation suppression control warning display 201...Lane Departure Prevention Control Status Display

Claims

[Claim 1] a surrounding situation recognition device that recognizes the surrounding situation of the vehicle; a steering state recognition unit that recognizes a steering state of the host vehicle; a driving control device that performs driving assistance control of the host vehicle based on the recognition results by the surrounding situation recognition device and the steering state recognition unit; A driving assistance device comprising: The steering state recognition unit a steering torque sensor provided on the steering shaft and a steering wheel touch sensor provided on the steering wheel, The driving control device includes: When the driver of the host vehicle does not interfere with the steering device for a predetermined time or while the host vehicle travels a predetermined distance and the detection is not performed by the steering state recognition unit, it is determined that the driver of the host vehicle is in a state where he or she cannot maintain normal traveling, When it is determined that the driver of the host vehicle is in a state where normal driving cannot be maintained, the driving assistance control being executed by the host vehicle is stopped, and after the driving assistance control is stopped, a first steering state determination process is performed to detect an output of either the steering wheel touch sensor or the steering torque sensor of the steering state recognition unit, and when an output of either the steering wheel touch sensor or the steering torque sensor is detected, the driving assistance control is restored, In the first held steering state determination process, if the output of neither the steering wheel touch sensor nor the steering torque sensor is detected, after a predetermined time has elapsed or after the host vehicle has traveled a predetermined distance, a second held steering state determination process is performed in which only the output of the steering torque sensor of the held steering state recognition unit is detected, and if the output of the steering torque sensor is detected and the output value of the steering torque sensor exceeds a predetermined threshold, the driving assistance control is restored. A driving assistance device characterized by:

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