Vehicle control device, vehicle control method, and program

Abstract

To provide a vehicle control device, a vehicle control method, and a program that can make a more appropriate distracted driving determination according to a surrounding situation of a vehicle.SOLUTION: A vehicle control device comprises: a recognition section that recognizes a surrounding situation of a vehicle; a driving state detection section that detects a driving state of an occupant of the vehicle; and a determination section that determines distracted driving of the occupant on the basis of a detection result of the driving state detection section. The determination section determines that the occupant is in distracted driving when steering operation of the occupant is not detected by the driving state detection section for a predetermined period of time or more, and the predetermined period of time is set on the basis of contact margin time between an obstacle near the vehicle and the vehicle, and speed of the vehicle.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle control device, a vehicle control method, and a program. [Background technology]

[0002] In recent years, efforts to provide access to sustainable transportation systems that take into consideration vulnerable traffic participants have become more active. To achieve this, efforts are being made to further improve traffic safety and convenience through research and development of preventive safety technologies. In this regard, a technology has been disclosed that detects distracted driving based on data on changes in the driver's line of sight and steering angle due to the driver's steering operation (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-243031 Summary of the Invention [Problem to be solved by the invention]

[0004] However, preventive safety technology does not take into account driving conditions such as the vehicle's speed and the positional relationship with the vehicle ahead when determining whether the vehicle is driving carelessly. As a result, there has been an issue with the conventional technology in that it has not been possible to properly determine whether the vehicle is driving carelessly, and in that case, it may not be possible to control the vehicle appropriately according to the circumstances around the vehicle.

[0005] In order to solve the above-mentioned problems, one of the objects of the present application is to provide a vehicle control device, a vehicle control method, and a program that can make a more appropriate determination of distracted driving in accordance with the vehicle's surrounding conditions, thereby contributing to the development of a sustainable transportation system. [Means for solving the problem]

[0006] The vehicle control device, vehicle control method, and program according to the present invention employ the following configuration. (1): A vehicle control device according to one embodiment of the present invention includes a recognition unit that recognizes the surrounding conditions of the vehicle, a driving state detection unit that detects the driving state of an occupant of the vehicle, and a judgment unit that judges whether the occupant is driving carelessly based on the detection result of the driving state detection unit, wherein the judgment unit judges that the occupant is driving carelessly when the driving state detection unit does not detect any steering operation of the occupant for a predetermined period of time or longer, and the predetermined period of time is set based on the contact margin time between the vehicle and an obstacle around the vehicle and the speed of the vehicle.

[0007] (2) In the above aspect (1), the predetermined time is set to be longer as the contact margin time is longer.

[0008] (3) In the above aspect (2), when the contact margin time is equal to or greater than a predetermined value, the predetermined time is such that the amount of adjustment of the time corresponding to the contact margin time is suppressed.

[0009] (4) In the above aspect (1), the predetermined time is set to be longer as the speed of the vehicle decreases.

[0010] (5): In the above aspect (4), when the speed of the vehicle is less than a predetermined speed, the amount of adjustment of the predetermined time corresponding to the speed of the vehicle is suppressed.

[0011] (6): In the above aspect (1), the predetermined time is set by multiplying a reference time, which is set based on the contact margin time and which indicates that the vehicle can travel without contacting the obstacle without any driving operation by the occupant, by a coefficient set based on the speed of the vehicle.

[0012] (7): In the above aspect (1), when the judgment unit determines that the occupant is driving aimlessly, the vehicle control unit further includes a control unit that controls one or both of the steering and acceleration / deceleration of the vehicle based on the contact margin time to warn the occupant.

[0013] (8) Another aspect of the present invention is a vehicle control method in which a computer recognizes the surrounding conditions of a vehicle, detects the driving state of an occupant of the vehicle, and, based on the detection results, determines that the occupant is driving aimlessly if no steering operation by the occupant is detected for a predetermined period of time or longer, the predetermined period of time being set based on the contact margin time between the vehicle and an obstacle around the vehicle and the speed of the vehicle.

[0014] (9): Another aspect of the present invention is a program that causes a computer to recognize the surrounding conditions of a vehicle, detect the driving state of an occupant of the vehicle, and, based on the detected results, determine that the occupant is driving aimlessly if no steering operation by the occupant is detected for a predetermined period of time or longer, the predetermined period of time being set based on the time to contact between the vehicle and an obstacle around the vehicle and the speed of the vehicle. [Effects of the Invention]

[0015] According to the above aspects (1) to (9), it is possible to make a more appropriate determination of absentminded driving depending on the surrounding conditions of the vehicle. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a configuration diagram of a vehicle on which a vehicle control device according to an embodiment is mounted; [Figure 2] FIG. 2 is a diagram for explaining the details of vehicle control according to the embodiment. [Figure 3] FIG. 10 is a diagram for explaining the details of attention-attraction control. [Figure 4] FIG. 10 is a diagram for explaining the content of contact warning control. [Figure 5]FIG. 10 is a diagram for explaining the content of automatic steering avoidance control. [Figure 6] FIG. 10 is a diagram for explaining steering control after a driver steering trigger. [Figure 7] 10 is a diagram for explaining the speed conditions of the host vehicle M under which control is started for each operation phase. FIG. [Figure 8] FIG. 10 is a diagram for explaining the determination of absentminded driving. [Figure 9] FIG. 10 is a diagram for explaining the relationship between time to contact TTC and continuation determination reference time. [Figure 10] 10 is a diagram for explaining the relationship between the speed VM of the host vehicle M and a vehicle speed coefficient. FIG. [Figure 11] 3 is a flowchart showing an example of processing executed by the driving assistance device 100 in the embodiment. [Figure 12] 10 is a flowchart illustrating an example of a nonchalant determination process. DETAILED DESCRIPTION OF THE INVENTION

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a vehicle control device, a vehicle control method, and a program according to the present invention will be described with reference to the accompanying drawings.

[0018] [Overall configuration] 1 is a configuration diagram of a vehicle equipped with a vehicle control device according to an embodiment. The vehicle equipped with the vehicle control device (hereinafter referred to as the subject vehicle M) is, for example, a two-wheeled, three-wheeled, or four-wheeled vehicle, and its drive source is an internal combustion engine such as a diesel engine or a gasoline engine, an electric motor, or a combination thereof. The electric motor operates using power generated by a generator connected to the internal combustion engine, or discharged power from a secondary battery or a fuel cell.

[0019] The host vehicle M is equipped with, for example, a camera 10, a radar device 12, a LIDAR (Light Detection and Ranging) 14, an object recognition device 16, a communication device 20, an HMI (Human Machine Interface) 30, vehicle sensors 40, a navigation device 50, an MPU (Map Positioning Unit) 60, a driver monitor camera 70, driving operators 80, a driving assistance device 100, a driving force output device 200, a braking device 210, and a steering device 220. These devices and equipment are connected to each other via multiple communication lines such as a CAN (Controller Area Network) communication line, serial communication lines, a wireless communication network, etc. Note that the configuration shown in FIG. 1 is merely an example, and some of the configuration may be omitted, or other configurations may be added. The driving assistance device 100 is an example of a "vehicle control device."

[0020] The camera 10 is, for example, a digital camera that uses a solid-state imaging element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). The camera 10 is attached to any location on the host vehicle M. For example, when capturing an image of the area ahead of the host vehicle M, the camera 10 is attached to the top of the front windshield or the back of the rearview mirror. The camera 10, for example, periodically and repeatedly captures images of the area around the host vehicle M. The camera 10 may be a stereo camera.

[0021] The radar device 12 emits radio waves such as millimeter waves around the vehicle M and detects radio waves reflected by an object (reflected waves) to detect at least the position (distance and direction) of the object. The radar device 12 is attached to any location on the vehicle M. The radar device 12 may detect the position and speed of an object using an FM-CW (Frequency Modulated Continuous Wave) method.

[0022] The LIDAR 14 irradiates the surroundings of the vehicle M with light (or electromagnetic waves with wavelengths similar to light) and measures the scattered light. The LIDAR 14 detects the distance to the target based on the time between light emission and light reception. The irradiated light is, for example, pulsed laser light. The LIDAR 14 is attached to any location on the vehicle M.

[0023] The object recognition device 16 performs sensor fusion processing on the detection results from some or all of the camera 10, the radar device 12, and the LIDAR 14 to recognize the position, type, speed, etc. of the object. The object recognition device 16 outputs the recognition results to the driving assistance device 100. The object recognition device 16 may output the detection results from the camera 10, the radar device 12, and the LIDAR 14 directly to the driving assistance device 100. The object recognition device 16 may be omitted from the host vehicle M. Some or all of the camera 10, the radar device 12, the LIDAR 14, and the object recognition device 16 are examples of "external environment detection devices."

[0024] The communication device 20 communicates with other vehicles in the vicinity of the vehicle M, for example, using a cellular network, a Wi-Fi network, Bluetooth (registered trademark), DSRC (Dedicated Short Range Communication), etc., or communicates with various server devices via a wireless base station.

[0025] The HMI 30 presents various information to the occupants of the vehicle M and accepts input operations by the occupants. The HMI 30 includes, for example, a display unit 32 and a speaker 34. The display unit 32 is, for example, an LCD (Liquid Crystal Display) or an organic EL (Electro Luminescence) display device. The display unit 32 displays various images (including videos) in the embodiment. The display unit 32 may be configured integrally with the input unit as a touch panel. The speaker 34 outputs a predetermined sound (for example, an alarm). Furthermore, the HMI 30 may include, in addition to (or instead of) the display unit 32 and the speaker 34, a microphone, a buzzer, a vibration generator (vibrator), a touch panel, a switch, a key, or the like.

[0026] The vehicle sensor 40 includes a vehicle speed sensor that detects the speed of the host vehicle M, an acceleration sensor that detects acceleration, a yaw rate sensor that detects the yaw rate (for example, the rotational angular velocity around a vertical axis passing through the center of gravity of the host vehicle M), and a direction sensor that detects the orientation of the host vehicle M. The vehicle sensor 40 may also be provided with a position sensor that detects the position of the host vehicle M. The position sensor is, for example, a sensor that acquires position information (longitude and latitude information) from a GPS (Global Positioning System) device. The position sensor may also be a sensor that acquires position information using a GNSS (Global Navigation Satellite System) receiver 51 of the navigation device 50.

[0027] The navigation device 50 includes, for example, a GNSS receiver 51, a navigation HMI 52, and a route determination unit 53. The navigation device 50 stores first map information 54 in a storage device such as a hard disk drive (HDD) or flash memory. The GNSS receiver 51 identifies the position of the vehicle M based on signals received from GNSS satellites. The position of the vehicle M may be identified or supplemented by an inertial navigation system (INS) that uses the output of the vehicle sensors 40. The navigation HMI 52 includes a display device, a speaker, a touch panel, keys, etc. The navigation HMI 52 may share some or all of the components with the HMI 30 described above. The route determination unit 53 determines, for example, a route (hereinafter, a route on a map) from the position of the vehicle M identified by the GNSS receiver 51 (or any input position) to a destination input by the occupant using the navigation HMI 52, with reference to the first map information 54. The first map information 54 is information that represents road shapes using, for example, links indicating roads and nodes connected by the links. The first map information 54 may also include information such as road curvature and POI (Point of Interest) information. The route on the map is output to the MPU 60. The navigation device 50 may provide route guidance using the navigation HMI 52 based on the route on the map. The navigation device 50 may be realized, for example, by the functions of a terminal device such as a smartphone or tablet device carried by the occupant. The navigation device 50 may transmit the current position and destination to a navigation server via the communication device 20 and obtain a route equivalent to the route on the map from the navigation server.

[0028] The MPU 60 includes, for example, a recommended lane determination unit 61 and stores second map information 62 in a storage device such as an HDD or flash memory. The recommended lane determination unit 61 divides the route on the map provided by the navigation device 50 into a plurality of blocks (for example, every 100 m in the vehicle travel direction) and determines a recommended lane for each block by referring to the second map information 62. The recommended lane determination unit 61 determines the number of lanes from the left in which to travel. Furthermore, when a branch point is present on the route on the map, the recommended lane determination unit 61 determines the recommended lane so that the host vehicle M can travel on a reasonable route to the branch point. The second map information 62 is map information with higher accuracy than the first map information 54. The second map information 62 includes, for example, information on the center of lanes, lane boundary information such as road dividing lines that divide lanes, etc. The second map information 62 may include road information, traffic regulation information, address information (address and postal code), facility information, telephone number information, etc. The second map information 62 may be updated as needed by the communication device 20 communicating with other devices. The first map information 54 and the second map information 62 may be stored in a storage unit within the driving assistance device 100.

[0029] The driver monitor camera 70 is a digital camera that uses a solid-state imaging device such as a CCD or CMOS. The driver monitor camera 70 is attached to any location on the vehicle M in a position and orientation that allows it to capture an image of the head and upper body (including the position of the hands) of an occupant (hereinafter referred to as the driver) seated in the driver's seat of the vehicle M from the front (in an orientation that captures the face). For example, the driver monitor camera 70 is attached to the top of a display device provided in the center of the instrument panel of the vehicle M. Therefore, the image captured by the driver monitor camera 70 includes the driver and the steering wheel 82, and it is also possible to determine from the image whether the driver is gripping the steering wheel 82. The driver monitor camera 70 outputs an image of the interior of the vehicle M, including the driver, captured from its installed position to the driving assistance device 100.

[0030] The driving operators 80 include, for example, a steering wheel 82, an accelerator pedal 84, a brake pedal 86, a turn signal switch, a shift lever, and other operators. The driving operators 80 are fitted with sensors that detect the amount of operation or the presence or absence of operation, and the detection results are output to the driving assistance device 100 or some or all of the driving force output device 200, the braking device 210, and the steering device 220.

[0031] For example, the steering wheel 82 is provided with a steering wheel sensor (SW sensor) 82A. The SW sensor 82A detects whether the driver is gripping the steering wheel 82 by using a contact sensor, a pressure sensor, or the like. The SW sensor 82A also detects the amount of operation of the steering wheel 82 (steer torque (input steering torque), steering amount) input (operated) by the driver. The SW sensor 82A may also detect the rate of change in operation (torque change rate). The steering wheel 82 does not necessarily have to be annular, and may be in the form of an irregularly shaped steering wheel, a joystick, a button, or the like. In this case, the SW sensor 82A detects the amount of operation according to the respective form.

[0032] An accelerator pedal sensor (AP sensor) 84A is attached to the accelerator pedal 84. The AP sensor 84A detects the amount of operation (opening) of the accelerator pedal 84, which changes in response to the driver's operation of the accelerator pedal 84. A brake pedal sensor (BP sensor) 86A is provided to the brake pedal 86. The BP sensor 86A detects the amount of operation (opening) of the brake pedal 86, which changes in response to the driver's operation of the brake pedal 86.

[0033] The driving force output device 200 outputs a driving force (torque) to the driving wheels for driving the host vehicle M. The driving force output device 200 includes, for example, a combination of an internal combustion engine, an electric motor, a transmission, etc., and an ECU (Electronic Control Unit) that controls these. The ECU controls the above components in accordance with information input from the driving assistance device 100 or information input from the driving operator 80.

[0034] Braking device 210 includes, for example, a brake caliper, a cylinder that transmits hydraulic pressure to the brake caliper, an electric motor that generates hydraulic pressure in the cylinder, and an ECU. The ECU controls the electric motor according to information input from driving assistance device 100 or information input from driving operator 80, so that a brake torque corresponding to the braking operation is output to each wheel. Braking device 210 may include a backup mechanism that transmits hydraulic pressure generated by operation of a brake pedal included in driving operator 80 to the cylinder via a master cylinder. Note that braking device 210 is not limited to the configuration described above, and may also be an electronically controlled hydraulic brake device that controls an actuator according to information input from driving assistance device 100 to transmit hydraulic pressure from a master cylinder to the cylinder.

[0035] The steering device 220 includes, for example, a steering ECU and an electric motor. The electric motor applies force to a rack and pinion mechanism to change the direction of the steered wheels. The steering ECU drives the electric motor to change the direction of the steered wheels in accordance with information input from the driving assistance device 100 or information input from the driving operator 80.

[0036] [Driving assistance devices] The driving assistance device 100 includes, for example, a recognition unit 110, a contact possibility determination unit 120, a driving state detection unit 130, a distracted driving determination unit 140, a vehicle control unit 150, an HMI control unit 160, and a storage unit 170. The recognition unit 110, the contact possibility determination unit 120, the driving state detection unit 130, the distracted driving determination unit 140, the vehicle control unit 150, and the HMI control unit 160 are realized by, for example, a hardware processor such as a CPU (Central Processing Unit) executing a program (software). Furthermore, some or all of these components may be realized by hardware (including circuitry) such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a GPU (Graphics Processing Unit), or may be realized by a combination of software and hardware. The program may be stored in advance in a storage device (a storage device having a non-transitory storage medium) such as an HDD or flash memory of the driving assistance device 100, or may be stored in a removable storage medium such as a DVD or CD-ROM, and installed in the HDD or flash memory of the driving assistance device 100 by inserting the storage medium (non-transitory storage medium) into a drive device. The absentminded driving determination unit 140 is an example of a "determination unit." The HMI control unit 160 is an example of a "notification control unit."

[0037] For example, the driving force output device 200, the braking device 210, and the steering device 220 are configured internally so that instructions from the driving support device 100 to the driving force output device 200, the braking device 210, and the steering device 220 are executed with priority over detection results from the driving operator 80. Regarding braking, if the braking force based on the operation amount of the brake pedal 86 is greater than the instruction from the driving support device 100, the latter may be executed with priority. Furthermore, communication priority in an in-vehicle local area network (LAN) may be used as a mechanism for executing instructions from the driving support device 100 with priority. Regarding steering, the steering force based on the instruction from the driving support device 100 may be added together with the steering force based on the operation amount of the steering wheel 82 by the driver.

[0038] The storage unit 170 may be realized by the various storage devices described above, or a solid state drive (SSD), an electrically erasable programmable read only memory (EEPROM), a read only memory (ROM), or a random access memory (RAM). The storage unit 170 stores, for example, programs, information used by components within the driving assistance device 100, and various other information. The storage unit 170 may also store the map information described above (first map information 54, second map information 62).

[0039] The recognition unit 110 recognizes the surrounding conditions of the vehicle M based on information input from an external environment detection device. For example, the recognition unit 110 recognizes the position (relative position, inter-vehicle distance), speed (relative speed), acceleration, and other states of objects present in the vicinity (e.g., within a predetermined distance from the vehicle M). Examples of objects include other vehicles, bicycles, pedestrians, etc. The position of an object is recognized as a position on an absolute coordinate system with a representative point of the vehicle M (e.g., the center of gravity or the center of the drive shaft) as the origin, and is used for control. The position of an object may be represented by a representative point such as the center of gravity or a corner of the object, or may be represented by an area. The "state" of an object may include the acceleration or jerk of the object, or the "behavior state" (e.g., whether or not the vehicle is changing lanes or is about to change lanes). The recognition unit 110 also recognizes the relative position and relative speed of the object.

[0040] The recognition unit 110 also recognizes, for example, the lane in which the host vehicle M is traveling (driving lane). For example, the recognition unit 110 recognizes the driving lane by comparing the pattern of road dividing lines (e.g., an arrangement of solid and dashed lines) obtained from the second map information 62 with the pattern of road dividing lines around the host vehicle M recognized from an image captured by the camera 10. The recognition unit 110 may recognize the driving lane by recognizing road boundaries (road boundaries) including not only road dividing lines but also road dividing lines, shoulders, curbs, medians, guardrails, etc. This recognition may take into account the position of the host vehicle M obtained from the navigation device 50 and processing results by the INS. The recognition unit 110 recognizes obstacles, stop lines, red lights, toll booths, and other road phenomena from the object recognition results. Obstacles are objects that the host vehicle M needs to avoid contacting, and include, for example, other vehicles.

[0041] When recognizing the driving lane, the recognition unit 110 recognizes the position and attitude of the host vehicle M with respect to the driving lane. For example, the recognition unit 110 may recognize the deviation of the reference point of the host vehicle M from the center of the lane and the angle it forms with a line connecting the centers of the lanes in the traveling direction of the host vehicle M as the relative position and attitude of the host vehicle M with respect to the driving lane. Alternatively, the recognition unit 110 may recognize the position of the reference point of the host vehicle M with respect to either side edge of the driving lane (a road dividing line or a road boundary) as the relative position of the host vehicle M with respect to the driving lane.

[0042] The contact possibility determination unit 120 determines whether or not there is a possibility of contact between the host vehicle M and an obstacle (e.g., another vehicle) based on the surrounding conditions (external environment information) recognized by the recognition unit 110. For example, the contact possibility determination unit 120 determines whether or not there is a possibility of contact between the host vehicle M and another vehicle based on a contact margin value with respect to another vehicle (leading vehicle) present ahead of the host vehicle M based on the surrounding conditions. The contact margin value is, for example, a value set based on a time to collision (TTC), but may also be a value set based on a time headway (THW). The time to collision (TTC) is derived, for example, by dividing the relative distance between the host vehicle M and another vehicle by the relative speed. Furthermore, the time headway (THW) is derived, for example, by dividing the relative distance (inter-vehicle distance) by the speed of the host vehicle M. The time to contact TTC may be derived using, for example, a trained model or a predetermined function that outputs the time to contact TTC when the positions and speeds of the host vehicle M and the other vehicle are input, or may be derived using a correspondence table that associates the relative speed and relative position with the time to contact TTC. The above derivation method also applies to the time to headway THW. For example, the shorter the time to contact TTC (or the time to headway THW), the smaller the contact margin value (in other words, the longer the contact margin time, the larger the contact margin value). For example, the contact possibility determination unit 120 determines that there is a possibility of contact between the host vehicle M and the other vehicle when the contact margin value is less than a threshold, and determines that there is no possibility of contact when the contact margin value is equal to or greater than the threshold.

[0043] The driving state detection unit 130 detects the driving state of the occupant (driver) of the host vehicle M. The driving state is, for example, the grip of the steering wheel 82 or the steering operation (steer torque, steering amount). In addition to (or instead of) the above, the driving state may be at least one of the accelerator operation or operation amount (opening) of the accelerator pedal 84 and the brake operation or operation amount (opening) of the brake pedal 86. The driving state is acquired based on the detection results of, for example, the SW sensor 82A, the AP sensor 84A, and the BP sensor 86A. The driving state detection unit 130 may also detect a state in which the driver is not performing a driving operation (for example, at least one of the steering operation, the accelerator operation, and the brake operation) based on the detection results of each sensor.

[0044] Furthermore, the driving state detection unit 130 may detect that the driver's state is not suitable for driving based on the analysis result of the image captured by the driver monitor camera 70. For example, the driving state detection unit 130 detects that the driver's state is not suitable for driving based on the analysis result of the image when the driver is not monitoring the surroundings (particularly the front) of the vehicle M due to looking away or when it is predicted that the driver's concentration is decreasing based on a predetermined facial expression (a face that looks sleepy, a face that looks pained) or the like.

[0045] The absentminded driving determination unit 140 determines whether the driver is driving absentmindedly based on the detection result of the driving state detection unit 130. The absentminded driving is, for example, a state in which the driver's driving operation of the vehicle M becomes slow (or does not operate at all) due to a decrease in the driver's attention or the like. For example, based on the detection result of the SW sensor 82A, the driving state detection unit 130 determines that the driver is driving absentmindedly when the state in which the steering operation of the steering wheel 82 by the driver is less than a threshold value (a determination threshold value TH1 described later) continues for a predetermined time (first predetermined time) or more, and determines that the driver is not driving absentmindedly when this state does not continue for the predetermined time or more.

[0046] Furthermore, instead of (or in addition to) the driver's steering operation, the absentminded driving determination unit 140 may detect that the driver is driving absentmindedly when a state in which the amount of change in the opening of the accelerator pedal 84 and the brake pedal 86 is less than a threshold continues for a predetermined time (second predetermined time) or more based on the detection results of the AP sensor 84A and the BP sensor 86A. Furthermore, instead of (or in addition to) the above determination, the absentminded driving determination unit 140 may determine that the driver is driving absentmindedly when a state in which the driving state detection unit 130 has detected that the driver's state is not suitable for driving continues for a predetermined time (third predetermined time) or more, and may determine that the driver is not driving absentmindedly when this state does not continue for the predetermined time or more. Note that the first predetermined time, the second predetermined time, and the third predetermined time may be the same or different times.

[0047] Furthermore, the absentminded driving determination unit 140 includes, for example, a time setting unit 142. The time setting unit 142 sets the above-mentioned predetermined times (first predetermined time, second predetermined time, third predetermined time) according to the surrounding circumstances of the host vehicle M, etc. For example, the time setting unit 142 sets the predetermined time based on the time to contact TTC between the host vehicle M and an obstacle (e.g., a preceding vehicle) in the vicinity of the host vehicle M, and the speed of the host vehicle M. Specifically, the time setting unit 142 sets the predetermined time to be shorter as the speed of the host vehicle M increases, or sets the predetermined time to be shorter as the time to contact TTC decreases. This makes it possible to more appropriately determine whether the host vehicle M is absentminded, based on the situation of the host vehicle M and the surrounding circumstances, which are based on the speed of the host vehicle M and the positional relationship between the host vehicle M and the obstacle.

[0048] The vehicle control unit 150 controls either or both of the steering and acceleration / deceleration of the host vehicle M based on the surrounding conditions recognized by the recognition unit 110. Furthermore, the vehicle control unit 150 may control either or both of the steering and acceleration / deceleration of the host vehicle M based on the processing results of at least one of the contact possibility determination unit 120, the driving state detection unit 130, and the absentminded driving determination unit 140. The vehicle control unit 150 includes, for example, a braking control unit 152 and a steering control unit 154.

[0049] The braking control unit 152 performs braking control of the host vehicle M in accordance with a driving operation by the driver of the host vehicle M (hereinafter referred to as a driver operation) or regardless of the driver operation, based on the recognition result of the recognition unit 110. For example, when it is determined that an obstacle exists ahead of the host vehicle M, the braking control unit 152 performs at least deceleration control of the host vehicle M based on a target deceleration of the host vehicle M. Furthermore, the braking control unit 152 sets a deceleration state based on a contact margin value between the host vehicle M and the obstacle, and executes deceleration control based on the set deceleration state. The braking control unit 152 includes, for example, gradual deceleration control and contact avoidance braking control.

[0050] The braking control unit 152 performs gradual deceleration control of the host vehicle M when the recognition unit 110 determines that an obstacle (e.g., another vehicle) is present ahead of the host vehicle M. The gradual deceleration control is a control (attention calling control) that uses the vehicle behavior of deceleration to make the driver aware of the approach of an obstacle and to call the driver's attention, and is different from contact avoidance control that avoids contact with the obstacle (however, it may result in avoiding contact with the obstacle). In addition, the gradual deceleration control is executed, for example, when the absentminded driving determination unit 140 determines that the driver is driving absentmindedly and the contact margin value satisfies the activation condition for the gradual deceleration control.

[0051] Furthermore, the braking control unit 152 may cancel the gradual deceleration control when the driving state detection unit 130 detects that the driver has operated the accelerator (operated the accelerator pedal 84) at a predetermined value (for example, a predetermined amount) or more during the gradual deceleration control. In this way, by determining the driver's intention based on the accelerator operation, it is possible to execute a more appropriate override control (switching to manual driving by the driver) for the gradual deceleration control. The predetermined value (predetermined amount) may be changed based on the operation speed of the driver's accelerator operation. For example, when the operation speed is equal to or greater than the predetermined speed, the braking control unit 152 sets the predetermined value smaller than when the operation speed is less than the predetermined speed (conversely, when the operation speed is less than the predetermined speed, the braking control unit 152 sets the predetermined value larger than when the operation speed is equal to or greater than the predetermined speed). Furthermore, the braking control unit 152 may change the predetermined value according to the target deceleration, for example, and set the predetermined value larger as the target deceleration increases. This allows for more appropriate override determination to be achieved according to the driver's driving situation and the surrounding conditions of the host vehicle M.

[0052] Furthermore, the braking control unit 152 performs emergency braking control as contact avoidance braking control to avoid contact between the host vehicle M and an obstacle. The contact avoidance braking control is braking control (deceleration control) to avoid contact when it is determined that the host vehicle M may come into contact with an obstacle based on the surrounding conditions recognized by the recognition unit 110. The contact avoidance braking control includes, for example, a Collision Mitigation Brake System (CMBS) control that assists in contact avoidance or damage mitigation. The contact avoidance braking control may be performed, for example, after gradual deceleration control, or may be performed when the contact margin value satisfies the operating condition for the contact avoidance braking control.

[0053] The steering control unit 154 controls the steering of the host vehicle M. The steering control unit 154 includes, for example, centering steering control and contact avoidance steering control. The centering steering control is steering control (centering steering control) that moves the host vehicle M toward the center of the driving lane when the recognition unit 110 determines that an obstacle exists ahead of the host vehicle M. This steering control is not intended to avoid contact with the obstacle, but is intended to make the driver aware of the obstacle ahead and to call his or her attention by vehicle behavior that moves laterally toward the center (however, it may result in avoiding contact with the obstacle). This steering control can make the driver aware of the obstacle ahead early, contributing to the driver's driving to avoid contact. Note that the centering steering control may be executed when the absentminded driving determination unit 140 determines that the driver is driving absentmindedly, and may also be executed when the contact margin value satisfies the steering control activation condition. The above-described gradual deceleration control and centering steering control may be executed separately, or may be executed simultaneously at the same timing (for example, during the attention-attraction control stage).

[0054] Furthermore, the steering control unit 154 performs, as contact avoidance steering control, steering control of the host vehicle M to avoid contact between the host vehicle M and an obstacle. The contact avoidance steering control moves the host vehicle M to a space where it will not come into contact with the obstacle within the same lane without relying on the driver's steering operation, when avoidance is possible within the host vehicle M's driving lane. The contact avoidance steering control may also perform steering control of the host vehicle M so that the behavior of the host vehicle M after the avoidance operation is stable after the driver's steering operation causes the host vehicle M to cross a dividing line that separates the driving lane and perform an avoidance operation against the obstacle. The contact avoidance steering control may be performed, for example, after the centering steering control, or may be performed when the contact margin value satisfies the operating condition for the contact avoidance steering control.

[0055] The vehicle control unit 150 may execute control other than the above-described vehicle control. For example, the vehicle control unit 150 may perform steering control to keep the host vehicle M within the driving lane as LKAS (Lane Keeping Assistance System) control (lane maintenance control). In this case, the vehicle control unit 150 assists the driver in steering the host vehicle M by controlling the steering device 220 so that the host vehicle M does not deviate from the driving lane, for example.

[0056] The HMI control unit 160 notifies the occupants (including the driver) of predetermined information via the HMI 30. The predetermined information includes, for example, information related to the traveling of the vehicle M, such as information related to the state of the vehicle M and information related to driving control. The information related to the state of the vehicle M includes, for example, the speed of the vehicle M, engine speed, shift position, etc. The information related to driving control includes, for example, the type of driving control being executed (e.g., gradual deceleration, centering steering control, contact avoidance braking control, contact avoidance steering control), the reason for operating the driving control, the status of the driving control, etc. The information related to driving control may also include information related to a warning to the driver or a contact warning alarm. The predetermined information may also include information related to the current location and destination of the vehicle M, the remaining amount of fuel, etc., and may also include information unrelated to the traveling control of the vehicle M, such as television programs, content (e.g., movies) stored on a storage medium such as a DVD, etc.

[0057] For example, the HMI control unit 160 may generate an image including the above-described predetermined information and display the generated image on the display unit 32 of the HMI 30, or may generate sound indicating the predetermined information and output the generated sound from the speaker 34 of the HMI 30. The timing at which the sound is output may be, for example, when driving control is started or stopped, when the image to be displayed is switched, or when the host vehicle M has entered a predetermined state. Furthermore, the HMI control unit 160 may output the information received by the HMI 30 to the vehicle control unit 150, etc.

[0058] [Vehicle control unit] Next, the details of vehicle control by the vehicle control unit 150 of the embodiment will be specifically described. Fig. 2 is a diagram for explaining the details of vehicle control of the embodiment. The example of Fig. 2 shows the details of vehicle control when it is determined that there is a possibility of contact based on the contact margin time TTC, which is an example of a contact margin value. In the example of Fig. 2, it is assumed that time T1 is the earliest, followed by times T2, T3, T4, and T5 in that order.

[0059] First, it is assumed that at time T1, the contact possibility determination unit 120 determines that there is a possibility of contact between the host vehicle M and an obstacle. Note that the absentminded driving determination unit 140 may have been continuously determining whether the driver is driving absentmindedly from a point in time prior to time T1. Details of the absentminded driving determination will be described later. If it is determined that there is a possibility of contact, the vehicle control unit 150 performs attention calling control ((1) in the figure) to call the driver's attention to the surroundings (particularly the direction of travel) based on the contact margin time TTC and the determination result of the absentminded driving determination unit 140.

[0060] FIG. 3 is a diagram for explaining the details of attention-calling control. The example of FIG. 3 shows lanes L1 and L2 that can be traveled in the same direction (X-axis direction in the figure). Lane L1 is defined by road dividing lines LN1 and LN2, and lane L2 is defined by road dividing lines LN2 and LN3. In the example of FIG. 3, the host vehicle M is traveling on lane L1 at a speed VM, and another vehicle (leading vehicle) m1 is located ahead of the host vehicle M and traveling on lane L1 at a speed Vm1. The other vehicle m1 is an example of an "obstacle."

[0061] 3, the vehicle control unit 150 performs the attention-calling control when the time to contact TTC based on the relative position and relative speed between the host vehicle M and the other vehicle m1 reaches a first predetermined value (predetermined time) or more at time T2 and the driver is determined to be driving carelessly. Time T2 is, for example, the time when the time to contact TTC reaches about 3 to 4 seconds.

[0062] The attention calling control includes, for example, at least one of gradual deceleration control and centering steering control. The gradual deceleration control executed in the attention calling control is a control in a first deceleration state. The braking control unit 152 sets a target deceleration (first target deceleration) so that a load (longitudinal G) of a first upper limit deceleration (approximately 0.1 [G]) is applied to the driver in the traveling direction (longitudinal direction). In addition, in the attention calling control (first deceleration state), the braking control unit 152 may first perform the gradual deceleration control at a first deceleration rate (e.g., 0.05 [G] longitudinal G), and then perform the deceleration control at a second deceleration rate (e.g., 0.1 [G] longitudinal G) that is greater than the first deceleration rate. By controlling the deceleration rate to increase in stages in this way, it is possible to reduce the load on occupants such as the driver when the execution of the gradual deceleration control starts, and to prevent the occupants from being surprised by the gradual deceleration control.

[0063] 3, the steering control unit 154 performs centering steering control to steer the host vehicle M so that a reference point such as the center of gravity or center of the host vehicle M is positioned in the center of the driving lane (lane L1). In the example of FIG. 3, the vehicle control unit 150 generates a future target trajectory K1 of the host vehicle M corresponding to the gradual deceleration control and the centering steering control, and controls the steering and speed of the host vehicle M so that the host vehicle M travels along the target trajectory K1.

[0064] At time T2, the HMI control unit 160 may generate an image indicating the reason for activation of the driver's attention alert control (gradual deceleration control, centering steering control) and notify the driver by displaying the generated image on the display unit 32. In this case, however, audio output may not be performed. This allows the driver to be easily notified of the approaching obstacle to be alerted, and prompts the driver to take early avoidance action.

[0065] Returning to Fig. 2, when the time to contact TTC (contact margin value) becomes less than a predetermined value (predetermined time) at time T3 in a state where the driver does not call attention to those around him / her (or perform override control) even after the above-mentioned attention calling control is performed, and the driver is determined to be driving carelessly, the contact attention warning control ((2) in the figure) is performed. Time T3 is the time when the time to contact TTC becomes approximately 2 seconds, for example.

[0066] FIG. 4 is a diagram for explaining the contents of the contact warning control. FIG. 4 shows a situation in which the time to contact TTC becomes 2 seconds without the driver operating the accelerator pedal, as in the situation shown in FIG. 3. In the contact warning control stage, the gradual deceleration control unit 142A sets a target deceleration (second target deceleration), executes gradual deceleration control according to the set second target deceleration, generates a target trajectory K2, and controls the host vehicle M to travel along the generated target trajectory K2. The gradual deceleration control executed in the contact warning control is control in the second deceleration state. In the second deceleration state, the braking control unit 152 sets the target deceleration (second target deceleration) so that the driver is subjected to a load (longitudinal G) in the traveling direction (longitudinal direction) that is equal to or less than a second upper limit deceleration (approximately 0.2 G) and greater than the first upper limit deceleration. This makes it possible to more clearly notify the driver that the host vehicle M is approaching another vehicle m1. In this way, deceleration control is performed while increasing the deceleration rate as needed, which creates more time for the driver to notice the other vehicle m1, allowing the driver to drive in a way that allows them to avoid contact with the other vehicle m1 with ease.

[0067] During the contact warning control, the above-described centering steering control may be executed in addition to (or instead of) the gradual deceleration control. Furthermore, during the contact warning control, the HMI control unit 160 may execute control (warning escalation control) to highlight the image of the warning information displayed on the display unit 32 or to output a warning to the speaker 34. This allows the driver to be notified by a strong image or sound that there is a high possibility of contact while decelerating, and more clearly urges the driver to be careful and to take control to avoid contact.

[0068] Returning to FIG. 2, after the execution of the contact attention warning control, at time T4 when the vehicle control unit 150 determines that automatic avoidance is possible within the driving lane based on the surrounding conditions recognized by the recognition unit 110, the steering control unit 154 executes automatic steering avoidance control ((3) shown in FIG. 2). FIG. 5 is a diagram for explaining the content of the automatic steering avoidance control. The example of FIG. 5 illustrates, for example, a control when the driver does not operate the accelerator after the execution of the contact attention warning control. In this case, the steering control unit 154 performs steering control based on the positional relationship between the driving lane area and the other vehicle m1, and if an avoidance space exists within the driving lane, generates a target trajectory K3 for traveling through the avoidance space, and executes steering control so that the host vehicle M travels along the generated target trajectory K3. The steering control unit 154 may also perform acceleration / deceleration control in addition to the steering control. During the automatic steering avoidance control, the HMI control unit 160 may continue to execute the above-mentioned warning escalation control. As a result, when steering avoidance is possible with highly safe control, automatic steering control can be executed, thereby realizing more appropriate vehicle control.

[0069] At this timing, the vehicle control unit 150 may execute CMBS control in parallel by the contact avoidance braking control unit 152B. When the CMBS control is executed, the above-mentioned automatic steering avoidance control and the contact avoidance steering control described later do not need to be executed.

[0070] Returning to FIG. 2, at time T5 when the driver operates the steering wheel 82 (detects the driver steering trigger) to perform a steering operation in a direction to avoid the other vehicle m1, the contact avoidance steering control unit 154B performs contact avoidance steering control so as not to further deviate from the adjacent lane (lane L2) adjacent to the driving lane (lane L1) ((4) in FIG. 2). The driver steering trigger is, for example, when the amount of steering operation by the driver to avoid the other vehicle m1 becomes equal to or greater than a predetermined amount. The contact avoidance steering control may be performed after the automatic steering avoidance control or after the contact attention warning control.

[0071] FIG. 6 is a diagram for explaining steering control after a driver steering trigger. In the example of FIG. 6, if there is no space in the host vehicle lane L1 to avoid contact of the host vehicle M with another vehicle m1 and if a driver steering trigger is detected, the steering control unit 154 allows the host vehicle M to move from the lane L1 to the adjacent lane L2 and performs steering control of the host vehicle M so that the host vehicle M does not further deviate from the adjacent lane L2. For example, a target trajectory K4 for changing lanes to the lane L2 is generated, and steering assistance is performed so that the position of the host vehicle M approaches the target trajectory K4 through steering operation by the driver. Furthermore, during contact avoidance steering control, the HMI control unit 160 may continue to perform the above-described warning escalation control. This allows for more appropriate vehicle control even when emergency avoidance steering is performed by the driver's steering operation.

[0072] Furthermore, when the time to contact TTC approaches a limit value after the attention warning control shown in (1) of Fig. 2 and the driver performs a steering operation, the vehicle control unit 150 executes contact avoidance steering control (driver steering assist control) ((5) of Fig. 2) to prevent the vehicle from crossing further into the adjacent lane, similar to the control shown in (4) of Fig. 2. In this case, the HMI control unit 160 may perform notification control such as a notification or an alarm that the contact avoidance steering control is operating.

[0073] In each of the operation phases of the attention alert, contact warning, automatic steering avoidance, and contact avoidance steering shown in FIG. 2, a condition related to the speed of the host vehicle M may be added to the determination conditions for operation. FIG. 7 is a diagram for explaining the speed conditions of the host vehicle M for starting control in each operation phase. For example, in the contact avoidance steering control in the automatic steering avoidance and contact avoidance steering (steering assistance), one of the operation start conditions is that the speed VM of the host vehicle M is 40 [km / h] or more. Because this control is performed after the attention alert, if the contact margin time TTC is approximately 2 [seconds], contact can be sufficiently avoided by the driver's braking operation. Furthermore, the centering steering control in the attention alert and contact warning is controlled to be performed when the speed VM of the host vehicle M is 30 [km / h] or more. Furthermore, the gradual deceleration control in the attention alert and contact warning is controlled to be performed when the speed VM of the host vehicle M is 30 [km / h] or more if the accelerator pedal is operated (AP operation). This speed is below the steering avoidance limit speed and is within a range where there is a performance margin for CMBS control, so setting this condition enables more appropriate driving control to be achieved. Furthermore, when there is no AP operation, control is performed so that the control is executed when the speed VM of the host vehicle M is 5 km / h or higher. In other words, when the driver's AP operation is not detected, the speed is set lower than when AP operation is detected. This relaxes the start condition for the gradual deceleration control when there is no AP operation, making it possible to execute the gradual deceleration control in various situations, including a state of mindless driving in a traffic jam, and more safely avoiding contact between the host vehicle M and another vehicle m1.

[0074] [Distracted driving detection unit] Next, the content of the determination of absentminded driving by the absentminded driving determination unit 140 will be described. FIG. 8 is a diagram for explaining the content of the determination of absentminded driving. In the example of FIG. 8, the horizontal axis represents time [seconds], and the vertical axis represents the steering torque [Nm] of the host vehicle M, the torque change rate, the steering state flag, and the absentmindedness determination flag. In the example of FIG. 8, the steering state flag is a flag that indicates whether or not the driver is performing a steering operation, and is set to "1" when the torque change rate is equal to or greater than a determination threshold TH1, indicating that a steering operation is being performed, and is set to "0" when the torque change rate is less than the determination threshold TH1, indicating that a steering operation is not being performed. In addition, the absentmindedness determination flag is a flag that indicates whether or not the driver is performing absentminded driving, and is set to "0" when it is determined that the driver is performing absentminded driving, and is set to "1" when it is determined that the driver is not performing absentminded driving.

[0075] For example, the absentminded driving determination unit 140 determines that the driver is driving absentmindedly when the amount of driving operation remains below the determination threshold for a predetermined time or more. Specifically, as shown in FIG. 8, the absentminded driving determination unit 140 calculates a torque change rate from the driver's steering torque obtained from the SW sensor 82A and determines whether the calculated torque change rate is equal to or greater than the determination threshold TH1. The absentminded driving determination unit 140 also determines that the driver is driving absentmindedly when the torque change rate remains below the determination threshold TH1 for a predetermined time or more ΔT1. For example, if attention warning control or collision warning control is performed based on the condition of absentminded driving, frequent switching between whether the driver is driving absentmindedly and whether the driver is driving absentmindedly will result in the above controls being frequently executed. Therefore, adding the condition of continuing for a predetermined time or more ΔT1 to determine whether the driver is driving absentmindedly can prevent the driver from feeling annoyed by the control switching.

[0076] [Time setting section] Next, the setting of the predetermined time by the time setting unit 142 will be described. For example, the time setting unit 142 sets the predetermined time ΔT1 by multiplying the continuation determination reference time, which is set based on the time to contact TTC between the host vehicle M and an obstacle (e.g., another vehicle m1), by a vehicle speed coefficient, which is set based on the speed VM of the host vehicle M. The continuation determination reference time is, for example, a time (reference time) for which it can be determined that the host vehicle M can travel without contacting an obstacle in a state where there is no driving operation by the driver (a state where the operation amount is less than a threshold). FIG. 9 is a diagram for explaining the relationship between the time to contact TTC and the continuation determination reference time. In the example of FIG. 9, the horizontal axis represents the time to contact TTC [seconds], and the vertical axis represents the continuation determination reference time [seconds]. In the example of FIG. 9, the continuation determination reference time [seconds] is set to become shorter as the time to contact TTC becomes shorter.

[0077] In the example of FIG. 9 , the continuation determination reference time is set to a certain value (e.g., approximately 0.3 seconds) when the time to contact TTC is 0 (zero), and is then set to linearly increase (become longer) as the time to contact TTC increases (becomes longer). Note that the increasing trend is not limited to the above example, and may increase nonlinearly (curve-like or stepwise). Furthermore, the continuation determination reference time may be adjusted by a reduced amount corresponding to the time to contact TTC when the time to contact TTC is equal to or greater than a predetermined value. Reducing the adjustment amount may include reducing the amount of time correction due to the time to contact TTC, or not correcting the time beyond the current amount (keeping the adjustment amount constant). In the example of FIG. 9 , the continuation determination reference time is set to a constant value (e.g., approximately 1.8 seconds) after there is sufficient time (e.g., approximately 24 seconds) until contact between the host vehicle M and the other vehicle m1. In this way, by setting the continuation judgment reference time based on the time to contact TTC, the predetermined time ΔT1 is set to be short when the driver is in imminent danger, making it possible to judge whether the driver is driving aimlessly in a short time. Also, when the danger is low, it is possible to take a certain amount of time to judge whether the driver is driving aimlessly, thereby improving the accuracy of the judgment.

[0078] FIG. 10 is a diagram illustrating the relationship between the speed VM of the host vehicle M and the vehicle speed coefficient. In the example of FIG. 10, the horizontal axis represents the speed VM [km / h] of the host vehicle M, and the vertical axis represents the vehicle speed coefficient. When the speed VM of the host vehicle M is low, the speed at which traffic conditions change is also slow, and it is considered that contact between the host vehicle M and another vehicle m1 can be sufficiently avoided by CMBS control or the like. Therefore, in the example of FIG. 10, the coefficient is increased as the speed VM decreases (becomes smaller), so that the predetermined time ΔT1 becomes longer. However, in reality, there are some cases of contact due to the driver being distracted in traffic congestion, etc. Therefore, when the speed VM is less than a predetermined speed, the adjustment amount (increase amount) of the vehicle speed coefficient corresponding to the speed VM may be suppressed. Suppressing the adjustment amount may include reducing the correction amount of the vehicle speed coefficient due to the speed VM, or not correcting it more than the current value (keeping the adjustment amount constant). In the example of FIG. 10, when the speed VM is less than a predetermined speed (for example, around 30 [km / h]), the coefficient is not further increased and remains constant. This can reduce the number of collisions caused by drivers looking away in traffic jams, etc. In the example of Fig. 10, the vehicle speed coefficient is set to increase (increase) nonlinearly (on a curve) as the speed V decreases (becomes smaller) until the speed VM becomes approximately 30 km / h or less, but it may also be set to increase linearly or in a stepwise manner.

[0079] 9 and 10 may be stored in, for example, the storage unit 170. When setting the predetermined time ΔT1, the time setting unit 142 refers to the storage unit 170, acquires the continuation determination reference time and the vehicle speed coefficient based on the current time to contact TTC and the speed VM of the host vehicle M from the corresponding information shown in FIGS. 9 and 10, and variably sets the predetermined time ΔT1. This allows the absentminded driving determination unit 140 to determine whether the vehicle is absentminded at an appropriate time, and can perform more appropriate vehicle control based on the determination result and in accordance with the surrounding conditions of the vehicle.

[0080] Furthermore, the time setting unit 142 may set the predetermined time period according to the driver's driving behavior and behavior while driving. For example, before the driver becomes distracted or careless, the driver may perform a preparatory behavior to stabilize the state of the host vehicle M. The preparatory behavior is, for example, a driving operation to increase the distance between the host vehicle M and an obstacle (a vehicle ahead) or to move the host vehicle M to a direction or position (e.g., the center of the lane) that makes it less likely for the host vehicle M to deviate from the lane. Therefore, when the time setting unit 142 recognizes the above-mentioned preparatory behavior based on the recognition result of the recognition unit 110, the time setting unit 142 may set the predetermined time period ΔT1 based on the speed VM of the host vehicle M. For example, when the host vehicle M is traveling at a speed of 60 to 70 km / h and a safety zone is secured around the host vehicle M by the preparatory behavior, the predicted time for the host vehicle M to stay within the lane without changing steering is approximately 5 seconds. Therefore, the time setting unit 142 sets the predetermined time period ΔT1 to be equal to or shorter than the time (approximately 5 seconds) corresponding to the safety zone secured by the preparatory behavior. This allows the determination of absentminded driving to be made within an area that is predicted to be safe.

[0081] Furthermore, during normal driving, for example, when the driver operates an in-vehicle device such as the navigation device 50 or an audio device (not shown), there is a certain amount of allowable time for looking away. In this case, the allowable time is approximately 2 seconds. Therefore, the time setting unit 142 may set the predetermined time ΔT1 to be equal to or greater than the allowable time (approximately 2 seconds) for operating an in-vehicle device of the host vehicle M. This prevents the generally allowable operation time for an in-vehicle device from being determined as distracted driving, and makes it possible to detect a distracted driving state that has a high possibility of leading to an accident.

[0082] [Processing flow] 11 is a flowchart showing an example of processing executed by the driving assistance device 100 in the embodiment. In the example of Fig. 11, a vehicle control processing including a distracted driving determination among the processing executed by the driving assistance device 100 will be described.

[0083] In the example of FIG. 11 , the recognition unit 110 recognizes the surrounding conditions of the host vehicle M (step S100). Next, the contact possibility determination unit 120 derives a time to contact TTC between the host vehicle M and an obstacle based on the recognized surrounding conditions (step S120). Next, the driving state detection unit 130 detects the driving state of the driver of the host vehicle M (step S140). Next, the absentminded driving determination unit 140 determines whether the driver is driving absentmindedly based on the detection result of the driving state by the driving state detection unit 130 (step S160). If it is determined that the driver is driving absentmindedly, the vehicle control unit 150 determines whether the time to contact TTC satisfies the activation condition for deceleration control or steering control (step S180). If it is determined that the time to contact TTC satisfies the activation condition for deceleration control or steering control, vehicle control that satisfies the activation condition is executed (step S200). This vehicle control includes, for example, the above-mentioned attention alert control, contact attention warning control, automatic steering avoidance control, and contact avoidance steering control. This ends the processing of this flowchart. Also, if it is determined in the processing of step S160 that the vehicle is not driving aimlessly, or if it is determined in the processing of step S180 that the time to contact TTC does not satisfy the conditions for operating the deceleration control or the steering control, the processing of this flowchart ends.

[0084] Fig. 12 is a flowchart showing an example of the absentmindedness determination process. The process shown in Fig. 12 is a specific example of the process of step S160 described above. In the example of Fig. 12, the time setting unit 142 acquires a continuation determination reference time from the time to contact TTC (step S161). Next, the time setting unit 142 acquires a vehicle speed coefficient from the speed VM of the host vehicle M (step S162). Next, the time setting unit 142 multiplies the continuation determination reference time by the vehicle speed coefficient to set a predetermined time ΔT1 (step S163).

[0085] Next, the absentminded driving determination unit 140 determines whether or not the driver's steering operation has not been detected continuously for a predetermined time ΔT1 or more (step S164). If it is determined that the steering operation has not been detected continuously for the predetermined time ΔT1 or more, the absentminded driving determination unit 140 determines that the driver is driving absentmindedly (step S165). If it is determined that the steering operation has not not been detected continuously for the predetermined time or more (i.e., the driver's steering operation has been detected), it determines that the driver is not driving absentmindedly (step S166). This ends the processing of this flowchart.

[0086] As described above, according to the embodiment, the vehicle is provided with a recognition unit 110 that recognizes the surrounding conditions of the vehicle M, a driving state detection unit 130 that detects the driving state of an occupant of the vehicle M, and a mindless driving determination unit (an example of a determination unit) 140 that determines whether the occupant is driving carelessly based on the detection result of the driving state detection unit 130. The mindless driving determination unit 140 determines that the occupant is driving carelessly when the driving state detection unit 130 does not detect a steering operation of the occupant for a predetermined time or longer, and the predetermined time is set based on the contact margin time between the vehicle and an obstacle in the vicinity of the vehicle and the speed of the vehicle, thereby making it possible to make a more appropriate mindless driving determination for the driver in accordance with the surrounding conditions of the vehicle M. Therefore, it is possible to provide more appropriate vehicle control for the occupant in accordance with the surrounding conditions of the vehicle M.

[0087] Specifically, according to an embodiment, for example, if steering torque input is not detected for a predetermined time, it is determined that the vehicle is driving aimlessly, and by varying this predetermined time based on the contact time TTC with an obstacle (e.g., a preceding vehicle) and the speed VM of the vehicle M, a more appropriate determination of aimless driving can be made depending on the driving conditions and surrounding conditions of the vehicle M.

[0088] For example, the shorter the distance to an obstacle ahead, the higher the possibility of contact. Therefore, in the embodiment, by setting the margin time to be shorter as the distance to the obstacle becomes shorter, it is possible to detect distracted driving early, and vehicle control (driving assistance) can be performed so that the driver notices the obstacle ahead or avoids contact. Furthermore, since it may not be possible to detect distracted driving if the margin time to the obstacle is set too long, in the embodiment, by setting the margin time to a constant when the distance to the obstacle is equal to or greater than a predetermined value, it is possible to appropriately determine distracted driving, and it is possible to detect distracted driving due to inattentive driving, etc., while reducing excessive determinations.

[0089] For example, as the speed VM of the host vehicle M increases, a speed difference between the host vehicle M and an obstacle ahead becomes more likely, and the speed difference shortens the time it takes to approach the obstacle ahead. Therefore, in the embodiment, the reference time for determining whether or not the host vehicle M is distracted is set to be shorter as the speed of the host vehicle M increases, thereby enabling early detection of distracted driving. Therefore, vehicle control to alert the driver to an obstacle ahead can be performed early, and driving assistance can be provided to avoid contact. Furthermore, as the speed decreases, the driver tends to be more likely to be distracted, etc. Therefore, in the embodiment, the change in the predetermined time due to speed is kept constant and the predetermined time is not made longer than necessary. This makes it possible to both prevent unnecessary distracted driving determinations at low speeds and detect distracted driving due to distracted driving, etc., and achieve more appropriate vehicle control.

[0090] [Variations] In the above-described embodiment, the slow deceleration control and centering steering control in the attention warning control and the collision warning control are performed when the driver is determined to be driving absentmindedly as one of the activation conditions. However, the slow deceleration control and the centering steering control may be selectively performed depending on whether the driver is driving absentmindedly. For example, the vehicle control unit 150 may perform the slow deceleration control and the centering steering control in the attention warning control and the collision warning control when the driver is determined to be driving absentmindedly, and may perform either the slow deceleration control or the centering steering control when the driver is determined not to be driving absentmindedly. Furthermore, the vehicle control unit 150 may not perform the centering steering control (for example, when the vehicle is traveling along a lane marking) or may perform the slow deceleration control when the host vehicle M moves in a direction approaching another vehicle m1 by performing the centering steering control. Furthermore, the vehicle control unit 150 may perform the slow deceleration control when the host vehicle M is unable to recognize the lane markings of the traveling lane, since the centering steering control is not possible. In the above-described embodiment, the gradual deceleration control and the centering steering control may be performed without determining whether or not the driver is driving absentmindedly.

[0091] In addition, in the absentminded driving judgment unit 140, the judgment threshold value TH1 regarding the driver's absentminded driving may be set variably, for example, depending on the road conditions on which the vehicle M is traveling (e.g., curved road, straight road, etc.), or may be set variably depending on the vehicle model of the vehicle M (steering characteristics for each vehicle model), etc.

[0092] Furthermore, in the above-described embodiment, the obstacle is not limited to the preceding vehicle, but may be another vehicle approaching the host vehicle M. Furthermore, the obstacle may be a pedestrian, a bicycle, or other object (not necessarily a moving body). Furthermore, the numerical values ​​shown in the above-described embodiment are merely examples, and may be adjusted as appropriate depending on the road conditions (shape, number of lanes, road type), the driver's driving conditions (degree of absentmindedness), the vehicle conditions (speed, vehicle type, shape, number of passengers), etc.

[0093] The above-described embodiment can be expressed as follows. a storage medium for storing computer-readable instructions; a processor connected to the storage medium; The processor executes the computer-readable instructions to: Recognizes the vehicle's surroundings, Detecting a driving state of an occupant of the vehicle; Based on the detection result, if a steering operation by the occupant is not detected for a predetermined period of time or more, it is determined that the occupant is driving aimlessly; The predetermined time is set based on a contact margin time between the vehicle and an obstacle in the vicinity of the vehicle and the speed of the vehicle. Vehicle control device.

[0094] The above describes the form for carrying out the present invention using an embodiment, but the present invention is not limited to such an embodiment, and various modifications and substitutions can be made within the scope that does not deviate from the gist of the present invention. [Explanation of symbols]

[0095] 10...camera, 12...radar device, 14...LIDAR, 16...object recognition device, 20...communication device, 30...HMI, 40...vehicle sensor, 50...navigation device, 60...MPU, 70...driver monitor camera, 80...driving operator, 82...steering wheel, 84...accelerator pedal, 86...brake pedal, 100...driving assistance device, 110...recognition unit, 120...contact possibility determination unit, 130...driving state detection unit, 140...distracted driving determination unit, 150...vehicle control unit, 152...braking control unit, 154...steering control unit, 160...HMI control unit, 170...memory unit, 200...driving force output device, 210...brake device, 220...steering device, M...host vehicle

Claims

1. a recognition unit that recognizes the surrounding situation of the vehicle; a driving state detection unit that detects a driving state of an occupant of the vehicle; a determination unit that determines whether the occupant is driving aimlessly based on the detection result of the driving state detection unit, The determination unit determines that the occupant is driving absentmindedly when the driving state detection unit has not detected a steering operation by the occupant for a predetermined period of time or longer, the predetermined time is set based on a contact margin time between the vehicle and an obstacle around the vehicle and a speed of the vehicle; the predetermined time is set to be shorter as the contact margin time is shorter and as the speed of the vehicle is higher, When the contact margin time is equal to or greater than a predetermined value, an adjustment amount of the predetermined time corresponding to the contact margin time is suppressed. Vehicle control device.

2. a recognition unit that recognizes the surrounding situation of the vehicle; a driving state detection unit that detects a driving state of an occupant of the vehicle; a determination unit that determines whether the occupant is driving aimlessly based on the detection result of the driving state detection unit, The determination unit determines that the occupant is driving absentmindedly when the driving state detection unit has not detected a steering operation by the occupant for a predetermined period of time or longer, the predetermined time is set based on a contact margin time between the vehicle and an obstacle around the vehicle and a speed of the vehicle; the predetermined time is set to be shorter as the contact margin time is shorter and as the speed of the vehicle is higher, When the speed of the vehicle is less than a predetermined speed, an adjustment amount of the predetermined time corresponding to the speed of the vehicle is suppressed. Vehicle control device.

3. a recognition unit that recognizes the surrounding situation of the vehicle; a driving state detection unit that detects a driving state of an occupant of the vehicle; a determination unit that determines whether the occupant is driving aimlessly based on the detection result of the driving state detection unit, The determination unit determines that the occupant is driving absentmindedly when the driving state detection unit has not detected a steering operation by the occupant for a predetermined period of time or longer, the predetermined time is set based on a contact margin time between the vehicle and an obstacle around the vehicle and a speed of the vehicle; the predetermined time is set to be shorter as the contact margin time is shorter and as the speed of the vehicle is higher, the predetermined time is set by multiplying a reference time, which is set based on the time to contact and which allows the vehicle to be determined to be able to travel without contacting the obstacle in a state in which there is no driving operation by the occupant, by a coefficient which is set based on a speed of the vehicle; the reference time is set to be smaller as the contact margin time becomes shorter, The coefficient is set to be larger as the speed of the vehicle decreases. Vehicle control device.

4. a recognition unit that recognizes the surrounding situation of the vehicle; a driving state detection unit that detects a driving state of an occupant of the vehicle; a determination unit that determines whether the occupant is driving aimlessly based on the detection result of the driving state detection unit, The determination unit determines that the occupant is driving absentmindedly when the driving state detection unit has not detected a steering operation by the occupant for a predetermined period of time or longer, the predetermined time is set based on a contact margin time between the vehicle and an obstacle around the vehicle and a speed of the vehicle; the predetermined time is set to be shorter as the contact margin time is shorter and as the speed of the vehicle is higher, The vehicle control unit further includes a vehicle control unit that, when the determination unit determines that the occupant is driving aimlessly, controls one or both of steering and acceleration / deceleration of the vehicle based on the contact margin time to warn the occupant. Vehicle control device.

5. The computer Recognizes the vehicle's surroundings, Detecting a driving state of an occupant of the vehicle; Based on the detection result, if a steering operation by the occupant is not detected for a predetermined period of time or more, it is determined that the occupant is driving aimlessly; the predetermined time is set based on a contact margin time between the vehicle and an obstacle around the vehicle and a speed of the vehicle; the predetermined time is set to be shorter as the contact margin time is shorter and as the speed of the vehicle is higher, When the contact margin time is equal to or greater than a predetermined value, an adjustment amount of the predetermined time corresponding to the contact margin time is suppressed. Vehicle control method.

6. The computer Recognizes the vehicle's surroundings, Detecting a driving state of an occupant of the vehicle; Based on the detection result, if a steering operation by the occupant is not detected for a predetermined period of time or more, it is determined that the occupant is driving aimlessly; the predetermined time is set based on a contact margin time between the vehicle and an obstacle around the vehicle and a speed of the vehicle; the predetermined time is set to be shorter as the contact margin time is shorter and as the speed of the vehicle is higher, When the speed of the vehicle is less than a predetermined speed, an adjustment amount of the predetermined time corresponding to the speed of the vehicle is suppressed. Vehicle control method.

7. The computer Recognizes the vehicle's surroundings, Detecting a driving state of an occupant of the vehicle; Based on the detection result, if a steering operation by the occupant is not detected for a predetermined period of time or more, it is determined that the occupant is driving aimlessly; the predetermined time is set based on a contact margin time between the vehicle and an obstacle around the vehicle and a speed of the vehicle; the predetermined time is set to be shorter as the contact margin time is shorter and as the speed of the vehicle is higher, the predetermined time is set by multiplying a reference time, which is set based on the time to contact and which allows the vehicle to be determined to be able to travel without contacting the obstacle in a state in which there is no driving operation by the occupant, by a coefficient which is set based on a speed of the vehicle; the reference time is set to be smaller as the contact margin time becomes shorter, The coefficient is set to be larger as the speed of the vehicle decreases. Vehicle control method.

8. The computer Recognizes the vehicle's surroundings, Detecting a driving state of an occupant of the vehicle; Based on the detection result, if a steering operation by the occupant is not detected for a predetermined period of time or more, it is determined that the occupant is driving aimlessly; the predetermined time is set based on a contact margin time between the vehicle and an obstacle around the vehicle and a speed of the vehicle; the predetermined time is set to be shorter as the contact margin time is shorter and as the speed of the vehicle is higher, When it is determined that the occupant is driving aimlessly, one or both of the steering and acceleration / deceleration of the vehicle are controlled based on the contact margin time, and a warning is issued to the occupant. Vehicle control method.

9. On the computer, Recognize the vehicle's surroundings, Detecting the driving state of an occupant of the vehicle; Based on the detection result, if a steering operation by the occupant is not detected for a predetermined period of time or more, it is determined that the occupant is driving absentmindedly; the predetermined time is set based on a contact margin time between the vehicle and an obstacle around the vehicle and a speed of the vehicle; the predetermined time is set to be shorter as the contact margin time is shorter and as the speed of the vehicle is higher, When the contact margin time is equal to or greater than a predetermined value, an adjustment amount of the predetermined time corresponding to the contact margin time is suppressed. program.

10. On the computer, Recognize the vehicle's surroundings, Detecting the driving state of an occupant of the vehicle; Based on the detection result, if a steering operation by the occupant is not detected for a predetermined period of time or more, it is determined that the occupant is driving absentmindedly; the predetermined time is set based on a contact margin time between the vehicle and an obstacle around the vehicle and a speed of the vehicle; the predetermined time is set to be shorter as the contact margin time is shorter and as the speed of the vehicle is higher, When the speed of the vehicle is less than a predetermined speed, an adjustment amount of the predetermined time corresponding to the speed of the vehicle is suppressed. program.

11. On the computer, Recognize the vehicle's surroundings, Detecting the driving state of an occupant of the vehicle; Based on the detection result, if a steering operation by the occupant is not detected for a predetermined period of time or more, it is determined that the occupant is driving absentmindedly; the predetermined time is set based on a contact margin time between the vehicle and an obstacle around the vehicle and a speed of the vehicle; the predetermined time is set to be shorter as the contact margin time is shorter and as the speed of the vehicle is higher, the predetermined time is set by multiplying a reference time, which is set based on the time to contact and which allows the vehicle to be determined to be able to travel without contacting the obstacle in a state in which there is no driving operation by the occupant, by a coefficient which is set based on a speed of the vehicle; the reference time is set to be smaller as the contact margin time becomes shorter, The coefficient is set to be larger as the speed of the vehicle decreases. program.

12. On the computer, Recognize the vehicle's surroundings, Detecting the driving state of an occupant of the vehicle; Based on the detection result, if a steering operation by the occupant is not detected for a predetermined period of time or more, it is determined that the occupant is driving absentmindedly; the predetermined time is set based on a contact margin time between the vehicle and an obstacle around the vehicle and a speed of the vehicle; the predetermined time is set to be shorter as the contact margin time is shorter and as the speed of the vehicle is higher, When it is determined that the occupant is driving aimlessly, one or both of the steering and acceleration / deceleration of the vehicle are controlled based on the contact margin time, thereby alerting the occupant. program.

Images