Vehicle control devices

Abstract

The vehicle control device (driving assistance ECU 10) determines whether an abnormality determination state has occurred, which can determine that the driver of the vehicle is in an abnormal state that makes it impossible to drive the vehicle. If an abnormality determination is made, the vehicle control device decelerates the vehicle at the normal deceleration rate DGnor. However, if it is predicted that the control limit of lane keeping control will be exceeded before the vehicle stops if the vehicle is decelerated at the normal deceleration rate DGnor from the time the abnormality determination is made, the vehicle control device decelerates the vehicle at a maximum deceleration rate DGmax that is greater than the normal deceleration rate DGnor.

Description

Technical Field

[0001] The present invention relates to a vehicle control device for decelerating and stopping a vehicle when a driver is in a state where the vehicle cannot be driven. Background Art

[0002] Conventionally, devices have been proposed that determine whether the driver is in an abnormal state, i.e., a state in which the driver has lost the ability to drive the vehicle, such as a drowsy driver or a state in which physical or mental functions have ceased, and control the vehicle upon such a determination. For example, one such device (hereinafter referred to as a "conventional device") executes lane keeping control, deceleration control, and warning control when it determines that the driver is in an abnormal state during lane keeping control (see, for example, Patent Document 1).

[0003] Lane keeping control automatically changes the vehicle's steering angle to keep it in its lane. Deceleration control slows the vehicle down and stops it. Warning control uses sound and / or light to alert the vehicle's interior and exterior.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-144808 (e.g., paragraphs 0083 to 0086) Summary of the Invention

[0007] Lane keeping control automatically stops (cancels) when, for example, the driving lane is curved and the vehicle's lateral acceleration exceeds a predetermined control limit. Conventional systems, even if the driver is determined to be in an abnormal state, will not only stop lane keeping control, but also deceleration control and warning control when lane keeping control is stopped. This means that conventional systems may not be able to effectively implement a determination that the driver is in an abnormal state, even if the determination is made.

[0008] The present invention is made to solve the above-mentioned problems. Specifically, one of the objects of the present invention is to provide a vehicle control device that, after determining that the driver has entered an abnormal state, can utilize this determination even in situations where lane keeping control has reached its control limit and stopped.

[0009] One embodiment of the vehicle control device of the present invention comprises:

[0010] A demarcation line information acquisition device (17b) includes a camera (camera) for photographing the front of the vehicle to acquire image data, and acquires demarcation line information based on the image data, the demarcation line information including information about a demarcation line demarcating a lane in which the vehicle is traveling, i.e., a driving lane, and information indicating a positional relationship between the demarcation line and the vehicle in a lane width direction;

[0011] A vehicle speed changing actuator (31, 41) capable of changing the speed of the vehicle, i.e., the vehicle speed;

[0012] A steering angle actuator (51, 52) capable of changing the steering angle of the vehicle;

[0013] A driving state sensor (11, 12, 14, 15, 16, 19a, 19b) capable of obtaining a driving state parameter representing the driving state of the vehicle;

[0014] A driver state sensor (11, 12, 13, 14, 15, 80) acquires a driver state parameter indicating a state of a driver of the vehicle;

[0015] Position acquisition means (20, 21) for acquiring a current time point position parameter representing the current time point position of the vehicle;

[0016] A lane information acquisition device (20, 22) acquires lane information including parameters indicating the shape of the driving lane based on the position of the vehicle; and

[0017] A control unit (10, 50) executes lane keeping control for controlling the steering angle actuator based on the demarcation line information so that the vehicle travels along the driving lane (step 1130), and stops the execution of the lane keeping control when it is determined that a control limit condition predetermined for the lane keeping control is met during the execution of the lane keeping control based on at least the driving state parameter (step 1120: yes, step 1160).

[0018] Furthermore, the control unit is configured as follows:

[0019] determining whether an abnormality determination state has occurred based on the driver state parameter, which can be determined as the driver being in an abnormal state where he cannot drive the vehicle (step 665),

[0020] When it is determined that the abnormal determination state has occurred, it is estimated based on the driving state parameter, the current time point position parameter, and the lane information whether a specific situation has occurred in which the control limit condition is satisfied before the vehicle stops when the vehicle is decelerated at the first deceleration (steps 850 and 1220).

[0021] When it is estimated that the specific situation has occurred, the vehicle speed change actuator is controlled so that the vehicle decelerates at a second deceleration having an absolute value greater than the absolute value of the first deceleration (steps 850 and 860, step 920, step 1220, and step 1240).

[0022] When it is estimated that the specific situation has not occurred, the vehicle speed change actuator is controlled so that the vehicle decelerates at the first deceleration rate (steps 850 and 830, step 920, step 1220, and step 1230).

[0023] According to this embodiment, when a determination is made that the abnormality-determined state has occurred, it is estimated (determined) whether a specific condition has occurred in which, assuming the vehicle is decelerated at the first deceleration rate, a control limit condition for lane keeping control is satisfied before the vehicle stops. If it is determined that the specific condition has not occurred, the vehicle is decelerated at the first deceleration rate. This prevents excessive deceleration, and allows the vehicle to travel in the driving lane and stop smoothly using lane keeping control.

[0024] In contrast, when a specific condition is estimated to have occurred, the vehicle is decelerated at a second deceleration rate having an absolute value greater than the first deceleration rate. This increases the likelihood of stopping the vehicle before lane keeping control is terminated. Furthermore, even if lane keeping control is terminated, the vehicle's speed can be significantly reduced before that point, improving safety.

[0025] In one embodiment of the device of the present invention,

[0026] the control unit,

[0027] Based on the driver state parameter, it is determined whether a temporary abnormal state has occurred, in which the driver may have fallen into the abnormal state but cannot be determined to have fallen into the abnormal determination state (step 645).

[0028] When a determination is made that the temporary abnormal state has occurred, from the time point when the determination is made that the temporary abnormal state has occurred, the vehicle speed change actuator is controlled so that the vehicle decelerates at a third deceleration having an absolute value less than the absolute value of the first deceleration (step 710, step 720, step 920).

[0029] According to this aspect, when it is suspected that the driver has fallen into the abnormal state, the vehicle can be gradually decelerated.

[0030] In one embodiment of the device of the present invention,

[0031] The control unit is configured as follows:

[0032] During the execution of the lane keeping control, a determination is performed as to whether the abnormality determination state has occurred and whether the temporary abnormality state has occurred (step 610 ).

[0033] Typically, during lane keeping control, the driver is required to, for example, hold the steering wheel (the state of not holding the steering wheel does not continue for more than a predetermined time). Therefore, according to this solution, it is possible to accurately determine whether an abnormality determination state has occurred and whether the temporary abnormal state has occurred.

[0034] In one embodiment of the device of the present invention,

[0035] The control unit is configured as follows:

[0036] Even when it is presumed that the specific condition does not occur, when it is determined that the vehicle will enter an uphill road with an inclination angle greater than a predetermined angle in the driving lane before stopping when the vehicle is assumed to be decelerated at the first deceleration (step 1610: yes), and when it is determined that the vehicle can stop before entering the uphill road when the vehicle is assumed to be decelerated at the second deceleration (step 1620: yes), the vehicle speed change actuator is controlled so that the vehicle decelerates at the second deceleration (step 1240).

[0037] According to this aspect, the possibility of stopping a vehicle whose driver is in an abnormal state before a steep uphill slope can be increased, thereby reducing the possibility of requiring emergency braking of a following vehicle.

[0038] In the above description, in order to help understand the present invention, the names and / or reference numerals (figure marks) used in the embodiments are added in parentheses to the configurations of the invention corresponding to the embodiments described later. However, the various constituent elements of the present invention are not limited to the embodiments specified by the names and / or reference numerals. Other objects, other features and incidental advantages of the present invention can be easily understood from the description of the embodiments of the present invention described with reference to the following drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic configuration diagram of a vehicle control device (first device) according to a first embodiment of the present invention.

[0040] Figure 2 It is a diagram for explaining the operation of the first device.

[0041] Figure 3 It is a diagram for explaining the operation of the first device.

[0042] Figure 4It is a diagram for explaining the operation of the first device.

[0043] Figure 5 It is a diagram for explaining the operation of the first device.

[0044] Figure 6 This is a flowchart showing a routine executed by the CPU of the first device.

[0045] Figure 7 This is a flowchart showing a routine executed by the CPU of the first device.

[0046] Figure 8 This is a flowchart showing a routine executed by the CPU of the first device.

[0047] Figure 9 This is a flowchart showing a routine executed by the CPU of the first device.

[0048] Figure 10 This is a flowchart showing a routine executed by the CPU of the first device.

[0049] Figure 11 This is a flowchart showing a routine executed by the CPU of the first device.

[0050] Figure 12 This is a flowchart showing a routine executed by the CPU of the vehicle control device (second device) according to the second embodiment of the present invention.

[0051] Figure 13 It is a diagram for explaining the operation of the vehicle control device (third device) according to the third embodiment of the present invention.

[0052] Figure 14 It is a diagram for explaining the operation of the third device.

[0053] Figure 15 It is a diagram for explaining the operation of the third device.

[0054] Figure 16 This is a flowchart showing a routine executed by the CPU of the third device.

[0055] Figure 17 This is a flowchart showing a routine executed by the CPU of the third device.

[0056] Label Description

[0057] 10…Driving assistance (vehicle control) ECU, 13…Touch sensor, 14…Steering angle sensor, 15…Steering torque sensor, 16…Vehicle speed sensor, 17a…Radar sensor, 17b…Camera device, 19b…Lateral acceleration sensor, 20…Navigation ECU, 21…GPS receiver, 22…Map database, 31…Powertrain actuator, 41…Brake actuator, 51…Motor driver, 52…Steering motor DETAILED DESCRIPTION

[0058] Hereinafter, a vehicle control device according to each embodiment of the present invention will be described with reference to the drawings.

[0059] <First embodiment>

[0060] A vehicle control device according to a first embodiment of the present invention (hereinafter sometimes referred to as "first device") is applied to a vehicle (hereinafter sometimes referred to as "own vehicle" to distinguish it from other vehicles). Figure 1 As shown, the first device includes a driving support (vehicle control) ECU 10 , a navigation ECU 20 , a power system ECU 30 , a brake ECU 40 , a steering ECU 50 , a meter ECU 60 , and a body ECU 70 .

[0061] These ECUs are electronic control units (ECUs) with microcomputers as their main components, and are connected to each other via CAN (Controller Area Network) in a manner that allows them to send and receive information. In this manual, a microcomputer includes a CPU, ROM, RAM, non-volatile memory, and an interface I / F. The CPU implements various functions by executing instructions (programs, routines) stored in the ROM. In other words, the CPU is a programmed processor. Some or all of these ECUs and the ECUs described later can also be integrated into a single ECU.

[0062] The driving assistance ECU 10 is connected to the following sensors (including switches) and receives detection signals or output signals from these sensors. Alternatively, each sensor may be connected to an ECU other than the driving assistance ECU 10. In this case, the driving assistance ECU 10 receives the sensor's detection signals or output signals from the ECU connected to the sensor via the CAN bus.

[0063] The accelerator pedal operation amount sensor 11 detects the operation amount (accelerator opening) of an accelerator pedal 11 a of the vehicle and outputs a signal indicating the accelerator pedal operation amount AP.

[0064] The brake pedal operation amount sensor 12 detects the operation amount of a brake pedal 12 a of the vehicle and outputs a signal indicating the brake pedal operation amount BP.

[0065] The touch sensor 13 outputs a high-level signal when the driver touches the steering wheel SW, and outputs a low-level signal when the driver does not touch the steering wheel SW.

[0066] The steering angle sensor 14 detects the steering angle of the vehicle and outputs a signal indicating the steering angle θ.

[0067] The steering torque sensor 15 detects a steering torque applied to a steering shaft US of the vehicle by an operation of the steering wheel SW, and outputs a signal indicating the steering torque Tra.

[0068] The vehicle speed sensor 16 detects the running speed of the vehicle (vehicle speed) and outputs a signal indicating the vehicle speed SPD.

[0069] The radar sensor 17a uses millimeter-wave radio waves to acquire information about the road ahead of the vehicle and three-dimensional objects (target objects) on the road (hereinafter referred to as "radar target object information"). Radar target object information includes the longitudinal distance Dfx(n) to the vehicle, the relative speed Vfx(n), and the direction H(n) of each detected target object (n).

[0070] The camera device 17b includes a “stereo camera and an image processing unit (ECU)”, neither of which is shown in the figure.

[0071] The stereo camera captures scenes in the left and right areas in front of the vehicle within a predetermined horizontal viewing angle centered on the longitudinal axis of the vehicle to obtain a pair of left and right image data.

[0072] The image processing unit identifies lane markings such as left and right white lines on the road (hereinafter referred to as "white lines") based on a pair of left and right image data captured by the stereo camera. Based on information regarding the identified white lines, the image processing unit obtains the radius of curvature (or the reciprocal of the radius of curvature, i.e., the curvature) of the lane in which the vehicle is currently traveling (hereinafter referred to as the "travel lane"), as well as parameters indicating the positional relationship between the white lines and the vehicle in the lane width direction.

[0073] Specifically, the camera device 17b includes a camera that captures the area in front of the vehicle and acquires image data. This camera device 17b constitutes a demarcation line information acquisition device that acquires demarcation line information based on this image data. This demarcation line information includes information about the demarcation lines (white lines) that demarcate the lane in which the vehicle is traveling, i.e., the driving lane, and information indicating the positional relationship between the demarcation lines and the vehicle's lane width. Furthermore, as long as the camera device 17b can acquire demarcation line information, it may include a monocular camera in place of a stereo camera. Furthermore, the camera device 17b acquires information regarding three-dimensional objects on the road in front of the vehicle (hereinafter referred to as "camera object information").

[0074] The operating switch 18 is a switch operated by the driver. By operating the operating switch 18, the driver can select whether to execute the lane keeping control (LTA: Lane Following Assist) described below. Furthermore, the driver can also select whether to execute the following vehicle distance control (ACC: Adaptive Cruise Control) by operating the operating switch 18.

[0075] Furthermore, the following vehicle distance control is a control that causes the vehicle to follow the preceding vehicle while maintaining the vehicle distance between the preceding vehicle (following target vehicle) and the preceding vehicle traveling directly in front of the vehicle at a predetermined distance based on the object information obtained by the radar sensor 17a and the camera device 17b. Furthermore, the following vehicle distance control is a control that causes the vehicle to travel in a manner such that the vehicle's actual speed is consistent with a predetermined target speed when there is no following target vehicle. The following vehicle distance control itself is well known, so a detailed description thereof will be omitted (for example, refer to Japanese Patent Application Publication No. 2014-148293, Japanese Patent Application Publication No. 2006-315491, Japanese Patent Specification No. 4172434, and Japanese Patent Specification No. 4929777).

[0076] A yaw rate sensor 19 a detects the yaw rate of the vehicle and outputs an actual yaw rate YRa.

[0077] The lateral acceleration sensor 19b detects the lateral acceleration of the vehicle and outputs an actual lateral acceleration Gy.

[0078] In addition, the accelerator pedal operation amount sensor 11, the brake pedal operation amount sensor 12, the steering angle sensor 14, the steering torque sensor 15, the vehicle speed sensor 16, the yaw rate sensor 19a and the lateral acceleration sensor 19b are driving state sensors that can obtain driving state parameters representing the driving state of the vehicle.

[0079] Furthermore, the accelerator pedal operation amount sensor 11, the brake pedal operation amount sensor 12, the contact sensor 13, the steering angle sensor 14, and the steering torque sensor 15 are driver state sensors that obtain driver state parameters indicating the state of the vehicle driver. Furthermore, the steering angle sensor may not be included as a driver state sensor, and other sensors other than those listed above may be included as driver state sensors.

[0080] The navigation ECU 20 is connected to a GPS receiver 21 that receives GPS signals for detecting the vehicle's position, a map database 22 that stores map information, and a touch-panel display 23. The navigation ECU 20 obtains the vehicle's current position (current position) Pnow based on the GPS signals, performs various calculations based on the vehicle's position Pnow and the map information stored in the map database 22, and provides route guidance using the display 23. The vehicle's position is represented by latitude and longitude. The navigation ECU 20 and the GPS receiver 21 constitute a position acquisition device that acquires current position parameters representing the vehicle's current position (Pnow).

[0081] The map information stored in the map database 22 includes lane information (road information). The lane information includes parameters indicating the shape of the lane (road) for each section (eg, lane curvature radius or curvature, and bank angle).

[0082] Therefore, the navigation ECU 20 and the map database 22 constitute a lane information acquisition device capable of acquiring lane information including parameters indicating the shape of the driving lane and the inclination angle of the driving lane. Furthermore, the navigation ECU 20 may be configured to acquire lane information including parameters indicating the shape of the driving lane and the inclination angle of the driving lane from outside the vehicle (e.g., an information center) using a communication device (not shown).

[0083] The powertrain ECU 30 is connected to a powertrain actuator 31. The powertrain actuator 31 is an actuator for controlling a powertrain (internal combustion engine and / or electric motor) 32 to change the driving force transmitted to the driving wheels of the vehicle.

[0084] The brake ECU 40 is connected to a brake actuator 41. The brake actuator 41 is an actuator for controlling a friction brake device 42 to change a braking force (friction braking force) applied to the vehicle.

[0085] Note that the powertrain actuator 31 and the brake actuator 41 are sometimes referred to as vehicle speed changing actuators capable of changing the speed of the vehicle (vehicle speed).

[0086] The steering ECU 50 is a control device for a well-known electric power steering system and is connected to a motor driver 51. The motor driver 51 is connected to a steering motor 52. The steering motor 52 is incorporated into a vehicle's (not shown) "steering mechanism including a steering wheel, a steering shaft connected to the steering wheel, and a steering gear mechanism." The steering motor 52 generates torque using the power supplied by the motor driver 51, and uses this torque to change the steering angle of the left and right steering wheels (i.e., the vehicle's steering angle). Furthermore, the motor driver 51 and the steering motor 52 together constitute a steering angle actuator capable of changing the vehicle's steering angle.

[0087] The meter ECU 60 is connected to hazard lights 61 , parking lights 62 , a buzzer (in-cabin alarm sound generating device) 63 , a meter display 64 , and the like, and can control them.

[0088] The body ECU 70 is connected to a horn (external alarm sound generating device) 71 .

[0089] Furthermore, the driving support ECU 10 is connected to a confirmation button 80. The confirmation button 80 is provided at a position operable by the driver, and outputs a low-level signal when not operated, and outputs a high-level signal when pressed.

[0090] (Work Summary)

[0091] The first device is designed based on the premise that the driving lane is composed of a combination of a straight road and a curved road with a constant curvature radius.

[0092] During execution of lane keeping control, the first device determines whether the driver is likely to be in an "unsuitable (ie, abnormal) state in which the driver cannot drive the vehicle" based on the "driver state parameter acquired by the driver state sensor."

[0093] When the first device determines that the driver may be in an abnormal state (i.e., when a temporary abnormality determination is made), the vehicle is slowly decelerated and stopped at the minimum deceleration DGmin, regardless of whether the control limit of the lane keeping control is subsequently reached and the lane keeping control is stopped (canceled).

[0094] For example, in Figure 2In the example shown, a temporary abnormality determination is made when the vehicle reaches point P21. After point P21, the vehicle decelerates at the minimum deceleration rate DGmin. Consequently, after the vehicle enters curved road C2 from point P22, it also decelerates at the minimum deceleration rate DGmin, stopping at point P23 in this example. In this case, even if the lane keeping control limit is reached and lane keeping control is stopped (cancelled) while the vehicle is traveling between points P22 and P23, the vehicle continues to decelerate at the minimum deceleration rate DGmin until it stops.

[0095] During execution of lane keeping control, the first device makes a temporary abnormality determination and then determines whether it can be determined that the driver is in an abnormal state based on the driver state parameter.

[0096] When the first device determines that it is possible to determine that the driver is in an abnormal state (i.e., when an abnormality determination is made), it predicts (determines) whether the control limit of the lane keeping control will be reached before the vehicle stops when the vehicle is decelerated at a "normal deceleration DGnor that is greater than the minimum deceleration DGmin".

[0097] When predicting (determining) that the control limit of the lane keeping control will not be reached, the first device decelerates the vehicle at the normal deceleration DGnor and stops it.

[0098] For example, in Figure 3 In the example shown, a temporary abnormality determination is made when the vehicle reaches point P31. After point P31, the vehicle decelerates at the minimum deceleration rate DGmin. Subsequently, a final abnormality determination is made when the vehicle reaches point P32. In this example, the first device predicts that the lane keeping control limit will not be reached even after the vehicle enters the curved road C3. Therefore, the first device decelerates the vehicle at the normal deceleration rate DGnor after point P32. Furthermore, in this example, when the vehicle reaches point P34 after passing the curved road C3 while executing lane keeping control, the vehicle stops.

[0099] In contrast, when the first device makes an abnormality determination judgment, if it is predicted that the control limit of lane keeping control will be reached before the vehicle stops when the vehicle is decelerated at the normal deceleration DGnor, the vehicle is decelerated and stopped at a "maximum deceleration DGmax greater than the normal deceleration DGnor".

[0100] For example, in Figure 4In the example shown, a provisional abnormality determination is made when the vehicle reaches point P41. After point P41, the vehicle decelerates at the minimum deceleration rate DGmin. Subsequently, a final abnormality determination is made when the vehicle reaches point P42. In this example, the first device predicts that the lane keeping control limit will be reached after the vehicle enters the curved road C4. Therefore, the first device decelerates the vehicle at the maximum deceleration rate DGmax after point P42. As a result, in this example, the vehicle stops at point P43, before entering the curved road C4.

[0101] For example, in Figure 5 In the example shown, a temporary abnormality determination is made when the vehicle reaches point P51, and the vehicle decelerates at the minimum deceleration DGmin after point P51. Subsequently, a final abnormality determination is made when the vehicle reaches point P52. In this example, the first device predicts that the control limit of lane keeping control will be reached after the vehicle enters curved road C5. Therefore, the first device decelerates the vehicle at the maximum deceleration DGmax after point P52. Furthermore, in this example, the vehicle stops at point P54 after entering curved road C5. In this case, even if the control limit of lane keeping control is reached and lane keeping control is stopped (canceled) while the vehicle is traveling between points P53 and P54, the vehicle decelerates at the maximum deceleration DGmax.

[0102] (Specific work)

[0103] Next, the operation of the CPU of the ECU 10 involved in the first device will be described. The CPU executes Figures 6 to 11 The routine shown in the flowchart.

[0104] Driver's abnormality judgment

[0105] When the predetermined timing comes, the CPU Figure 6 The process starts from step 600 and proceeds to step 605 to determine whether the value of the abnormality determination flag XHijo is "0".

[0106] The value of the abnormality determination flag XHijo is set to "0" in an initialization routine (not shown) executed by the CPU when the ignition key switch (not shown) is turned from the OFF position to the ON position. Furthermore, as will be described later, the value of the abnormality determination flag XHijo is set to "1" when it is determined that the driver of the own vehicle has "entered a state in which the driver cannot drive the own vehicle (i.e., an abnormal state)."

[0107] If the value of the abnormality determination flag XHijo is not "0" (is "1"), the CPU makes a "No" determination in step 605, directly proceeds to step 695, and temporarily ends this routine.

[0108] On the other hand, when the value of the flag XHijo is “0”, the CPU makes a “Yes” determination in step 605 and proceeds to step 610 to determine whether the lane keeping control is currently being executed.

[0109] If the lane keeping control is not being executed, the CPU makes a “No” determination in step 610 , sequentially performs the processes of “step 615 and step 620 ” described below, proceeds to step 695 , and temporarily ends this routine.

[0110] Step 615: The CPU sets the value of an abnormality determination timer Tijo, which will be described later, to "0".

[0111] Step 620: The CPU sets the value of the temporary abnormality determination flag XKijo and the value of the abnormality determination flag XHijo to "0".

[0112] The value of the temporary abnormality determination flag XKijo is set to "0" in the above-mentioned initialization routine, and is set to "1" when it is determined that the driver "may be in an abnormal state" (ie, when a temporary abnormality determination is made) as described later.

[0113] In contrast, if lane keeping control is being executed, the CPU determines "yes" in step 610 and proceeds to step 625 to determine whether the current time point is a no-drive state. The no-drive state refers to a state in which any of the parameters, consisting of one or more combinations of "accelerator pedal operation amount AP, brake pedal operation amount BP, steering torque Tra, and the low-level signal output from the contact sensor 13," remain unchanged by the driver from "a time point a predetermined time before the current time point" to "the current time point."

[0114] If the current time point is not the driving no-operation state, the CPU determines "No" in step 625, performs the above-mentioned "processing of step 615 and step 620" in sequence, proceeds to step 695 and temporarily ends this routine.

[0115] If the current time point is the driving no-operation state, the CPU determines "yes" in step 625 and proceeds to step 630. In step 630, the CPU increases the value of the abnormality determination timer Tijo by "1". Therefore, the value of the abnormality determination timer Tijo indicates the duration of the driving no-operation state.

[0116] Next, the CPU proceeds to step 635 to determine whether the value of the abnormality determination timer Tijo is greater than the warning start threshold time Tkeikoku. If the value of the abnormality determination timer Tijo is less than the warning start threshold time Tkeikoku, the CPU makes a "no" determination in step 635, proceeds directly to step 695, and temporarily terminates this routine.

[0117] In contrast, if the value of the abnormality determination timer Tijo is greater than or equal to the warning start threshold time Tkeikoku, the CPU makes a "YES" determination in step 635 and proceeds to step 640. In step 640, the CPU transmits an instruction signal to the meter ECU 60, causing the buzzer 63 to generate a warning sound, causing the meter display 64 to flash a "warning light" and display a "warning message urging operation of one of the accelerator pedal 11a, brake pedal 12a, and steering wheel SW."

[0118] Next, the CPU proceeds to step 645 to determine whether the value of the abnormality determination timer Tijo is greater than the temporary abnormality determination threshold time TKijoth. The temporary abnormality determination threshold time TKijoth is set to a value longer than the warning start threshold time Tkeikoku. If the value of the abnormality determination timer Tijo is less than the temporary abnormality determination threshold time TKijoth, the CPU determines "No" in step 645 and proceeds directly to step 695, temporarily terminating this routine.

[0119] In contrast, if the value of the abnormality determination timer Tijo is greater than the temporary abnormality determination threshold time TKijoth, the CPU makes a "Yes" determination in step 645 and proceeds to step 650. In step 650, the CPU sets the value of the temporary abnormality determination flag XKijo to "1." Specifically, if the driving inactivity state continues for a time period equal to or greater than the temporary abnormality determination threshold time TKijoth, the CPU determines that the driver may be in a state where he or she is unable to drive the vehicle (i.e., an abnormal state).

[0120] Next, the CPU proceeds to step 655 to determine whether the value of the abnormality determination timer Tijo is greater than the abnormality determination threshold time THijoth. The abnormality determination threshold time THijoth is set to a time longer than the temporary abnormality determination threshold time TKijoth. If the value of the abnormality determination timer Tijo is less than the abnormality determination threshold time THijoth, the CPU determines "No" in step 655 and proceeds directly to step 695, temporarily terminating this routine.

[0121] In contrast, when the value of the abnormality determination timer Tijo is greater than the abnormality determination threshold time THijoth, the CPU determines "yes" in step 655 and proceeds to step 660. In step 660, the CPU sets the value of the temporary abnormality determination flag XKijo to "0" and sets the value of the abnormality determination flag XHijo to "1". The CPU then proceeds to step 695 and temporarily ends this routine. That is, when the duration of the driving no-operation state continues for a time equivalent to the abnormality determination threshold time THijoth or longer, the CPU determines that the driver has fallen into a state (i.e., an abnormal state) in which he cannot drive his own vehicle.

[0122] In this way, when the driving inactivity state lasts for a time equal to or longer than the warning start threshold time Tkeikoku, a warning is issued to the driver to urge them to take driving action. Subsequently, when the driving inactivity state lasts for a time equal to or longer than the temporary abnormality determination threshold time TKijoth, it is determined that the driver may have entered an abnormal state, and the value of the temporary abnormality determination flag XKijo is set to "1." In other words, a temporary abnormality determination is made. Furthermore, when the driving inactivity state lasts for a time equal to or longer than the abnormality determination finalization threshold time THijoth, it is determined that the driver has entered an abnormal state, and the value of the abnormality determination finalization flag XHijo is set to "1." In other words, a final abnormality determination is made.

[0123] Target deceleration setting processing during temporary abnormality judgment

[0124] When the predetermined timing comes, the CPU Figure 7 The process begins at step 700 and proceeds to step 710, where it is determined whether a temporary abnormality determination has been made at the current time point (i.e., whether the value of the temporary abnormality determination flag XKijo is "1"). If a temporary abnormality determination has not been made at the current time point (i.e., if the value of the temporary abnormality determination flag XKijo is "0"), the CPU makes a "No" determination in step 710, directly proceeds to step 795, and temporarily terminates this routine.

[0125] In contrast, if a temporary abnormality determination is made at the current time point (i.e., the value of the temporary abnormality determination flag XKijo is "1"), the CPU determines "yes" in step 710 and proceeds to step 720. In step 720, the CPU sets the value of the target deceleration DGtgt to a constant minimum deceleration DGmin. Furthermore, in this specification, deceleration is represented by a positive value, indicating the amount of reduction in vehicle speed per unit time. Therefore, the greater the deceleration, the faster the vehicle speed decreases. The CPU then proceeds to step 795, temporarily terminating this routine.

[0126] In this manner, when a temporary abnormality determination is made at the current time point, the value of the target deceleration DGtgt is set to the minimum deceleration DGmin. In addition, the minimum deceleration DGmin may be referred to as the "third deceleration" for convenience.

[0127] Target deceleration setting processing when abnormality determination is made

[0128] When the predetermined timing comes, the CPU Figure 8 The process starts at step 800 and proceeds to step 810 to determine whether the current time point is a time point immediately after the abnormality determination is made. In other words, the CPU determines whether the current time point is a time point immediately after the abnormality determination flag XHijo changes from '0' to '1'.

[0129] If the current time point is not a time point immediately after the time point at which the abnormality determination is made, the CPU makes a “No” determination in step 810 , directly proceeds to step 895 , and temporarily ends this routine.

[0130] In contrast, if the current time point is immediately after the time point at which the abnormality determination was made, the CPU determines "yes" in step 810 and proceeds to step 820. In step 820, the CPU determines whether the lane in which the vehicle is currently traveling (i.e., the driving lane) is a straight road based on the curvature radius R obtained by the camera device 17b. More specifically, the CPU determines that the driving lane is a straight road if the curvature radius R is greater than the curved road determination threshold Rctth.

[0131] In the case where the driving lane is not a straight road (that is, in the case of a curved road), since lane keeping control is being executed at the current time point, it is considered that the situation of "the control limit of lane keeping control is reached and the lane keeping control is stopped (canceled)" will not occur later. Therefore, in this case, the CPU determines "no" in step 820 and proceeds to step 830. In step 830, the CPU sets the value of the target deceleration DGtgt to "a constant normal deceleration DGnor greater than the minimum deceleration DGmin (a normal deceleration DGnor with an absolute value greater than the absolute value of the minimum deceleration DGmin)". After that, the CPU proceeds to step 895 and temporarily ends this routine. In addition, the normal deceleration DGnor is sometimes referred to as "the first deceleration" for convenience. Although the absolute value of the normal deceleration DGnor can also be equal to the absolute value of the minimum deceleration DGmin, it is preferably larger than the absolute value of the minimum deceleration DGmin.

[0132] On the other hand, if the driving lane is a straight road at the time the CPU proceeds to step 820, the CPU determines "yes" in step 820 and proceeds to step 840. In step 840, the CPU determines whether the vehicle will enter a curved road before stopping, if the vehicle decelerates at the normal deceleration rate DGnor from the current vehicle speed. Specifically, based on the current vehicle speed SPD, the normal deceleration rate DGnor, and the information (lane information) obtained from the map database 22 via the navigation ECU 20, the CPU determines whether there is a "portion where the curvature radius R is less than the curve determination threshold Rctth" in the driving lane that the vehicle is expected to pass before stopping.

[0133] If the vehicle is decelerating at the normal deceleration rate DGnor and the vehicle will not enter the curve before stopping, the CPU makes a "No" determination in step 840, executes the process of step 830, and then proceeds to step 895 to temporarily terminate this routine. Therefore, in this case, the value of the target deceleration rate DGtgt is set to the normal deceleration rate DGnor.

[0134] In contrast, if the vehicle is expected to enter a curve before stopping after decelerating at the normal deceleration rate DGnor, the CPU determines "yes" in step 840 and proceeds to step 850. In step 850, the CPU determines whether the control limit condition for lane keeping control is met on the curve that the vehicle is predicted to enter after decelerating at the normal deceleration rate DGnor from the current vehicle speed. In other words, the CPU determines whether the vehicle can complete the curve without having lane keeping control canceled (stopped) (including situations where the vehicle stops while traveling on the curve). The control limit condition for lane keeping control is met, for example, at least when "the vehicle's lateral acceleration is greater than or equal to the control limit lateral acceleration Gyth."

[0135] More specifically, the CPU calculates and predicts the vehicle speed at the time of entering the curve that the vehicle is predicted to enter if the vehicle is decelerated at the normal deceleration rate DGnor from the current vehicle speed (hereinafter referred to as the "curved road entry speed"). Then, in step 850, the CPU estimates the vehicle's lateral acceleration based on the curved road entry speed and the radius of curvature of the curved road, and determines whether the estimated lateral acceleration is less than the control limit lateral acceleration.

[0136] If the control limit conditions for lane keeping control on the predicted curved road do not hold (i.e., if the estimated lateral acceleration is less than the control limit lateral acceleration), the CPU makes a "yes" determination in step 850 and proceeds to step 830. In step 830, the CPU sets the target deceleration DGtgt to the normal deceleration DGnor. The CPU then proceeds to step 895 and temporarily terminates this routine.

[0137] In contrast, when the control limit condition of the lane keeping control on the curved road that is predicted to be entered is met (that is, when the estimated lateral acceleration is above the control limit lateral acceleration and the curved road cannot be completed), the CPU determines "No" in step 850 and proceeds to step 860. In step 860, the CPU sets the value of the target deceleration DGtgt to "a constant maximum deceleration DGmax that is larger than the normal deceleration DGnor (a maximum deceleration DGmax having an absolute value larger than the absolute value of the normal deceleration DGnor)". After that, the CPU proceeds to step 895 and temporarily ends this routine. In addition, the maximum deceleration DGmax is the maximum value of the deceleration of the own vehicle allowed by the system, and is sometimes referred to as the "second deceleration" for convenience.

[0138] ·Deceleration control when abnormality is determined

[0139] When the predetermined timing comes, the CPU Figure 9 The process begins at step 900 and proceeds to step 910, where it is determined whether either the value of the temporary abnormality determination flag XKijo or the value of the abnormality determination flag XHijo is "1." If both the value of the temporary abnormality determination flag XKijo and the value of the abnormality determination flag XHijo are "0," the CPU determines "No" in step 910, directly proceeds to step 995, and temporarily ends this routine.

[0140] On the other hand, when either the value of the temporary abnormality determination flag XKijo or the value of the abnormality final determination flag XHijo is “1”, the CPU makes a “Yes” determination in step 910 and proceeds to step 920 .

[0141] In step 920, the CPU decelerates the vehicle so that its actual deceleration (the absolute value of the decrease in vehicle speed SPD per unit time) matches the target deceleration DGtgt. The CPU then proceeds to step 930 to generate an alarm both inside and outside the vehicle. More specifically, the CPU instructs the instrument ECU 60 to flash the hazard lights 61, illuminate the parking lights 62, generate an internal alarm from the buzzer 63, and display a warning on the instrument display 64. Furthermore, the CPU instructs the body ECU 70 to generate an external alarm from the speaker 71. The CPU then proceeds to step 995, temporarily terminating this routine.

[0142] Lane keeping control start permission judgment

[0143] When the predetermined timing comes, the CPU Figure 10 The process begins at step 1000 and proceeds to step 1010, where it is determined whether the value of the lane keeping control permission flag XLTA is "0." The value of the lane keeping control permission flag XLTA is set to "0" in the aforementioned initialization routine. If the value of the lane keeping control permission flag XLTA is not "0" (is "1"), the CPU determines "No" in step 1010, proceeds to step 1095, and temporarily terminates this routine.

[0144] On the other hand, when the value of the lane keeping control permission flag XLTA is "0", the CPU makes a "Yes" determination at step 1010 and proceeds to step 1020. At step 1020, the CPU determines whether the lane keeping control start permission condition is satisfied.

[0145] The lane keeping control start permission condition is satisfied when all of the following conditions are satisfied.

[0146] (Condition A1) Immediately after the lane keeping control is selected by operating the operating switch 18.

[0147] (Condition A2) During execution of the following inter-vehicle distance control.

[0148] (Condition A3) The magnitude of the actual lateral acceleration Gy is smaller than the control limit lateral acceleration Gyth.

[0149] (Condition A4) The left and right lane markings (white lines) of the road are recognized by the camera device 17b.

[0150] If the lane keeping control start permission condition is not satisfied, the CPU makes a “No” determination at step 1020 , directly proceeds to step 1095 , and temporarily ends this routine.

[0151] In contrast, if the lane keeping control start permission condition is met, the CPU determines "yes" in step 1020 and proceeds to step 1030. In step 1030, the CPU sets the lane keeping control permission flag XLTA to "1", directly proceeds to step 1095, and temporarily ends this routine.

[0152] Execution and termination determination of lane keeping control

[0153] When the predetermined timing comes, the CPU Figure 11 The process begins at step 1100 and proceeds to step 1110, where it determines whether the lane keeping control permission flag XLTA is "1." If the lane keeping control permission flag XLTA is not "1," the CPU returns a "No" determination at step 1110, proceeding directly to step 1195 and terminating this routine. In this case, lane keeping control is not executed.

[0154] In contrast, if the lane keeping control permission flag XLTA is "1," the CPU determines "yes" in step 1110 and proceeds to step 1120 to determine whether the control limit condition for lane keeping control has actually been met. In this case, the CPU determines whether the actual lateral acceleration Gy is greater than the control limit lateral acceleration Gyth.

[0155] If the control limit condition for lane keeping control is not met, the CPU determines "No" in step 1120 and proceeds to step 1130 to execute lane keeping control. Lane keeping control is a well-known control method that applies steering torque to the steering mechanism to assist the driver's steering operation so that the vehicle's lane width direction position is maintained near a target travel line within the "travel lane (the lane in which the vehicle is currently traveling)" (for example, see Japanese Patent Application Publication Nos. 2008-195402, 2009-190464, 2010-6279, and Japanese Patent No. 4349210). Therefore, the following is a brief explanation.

[0156] Based on the image data transmitted from the camera device 17b, the CPU identifies (acquires) the left and right white lines LL and LR defining the travel lane and determines the center position of these white lines as the target travel line Ld. Furthermore, the CPU calculates the radius of curvature (curve radius) R of the target travel line Ld and the position and orientation of the vehicle in the travel lane.

[0157] The CPU then calculates the distance Dc in the lane width direction between the front center position of the vehicle and the target driving line Ld (hereinafter referred to as the "center distance Dc"), and the deviation angle θy between the direction of the target driving line Ld and the direction of the vehicle (hereinafter referred to as the "yaw angle θy").

[0158] The CPU then calculates the target yaw rate YRtgt by applying the center distance Dc, yaw angle θy, and curvature ν (=1 / radius of curvature R) to the following equation (1). In equation (1), K1, K2, and K3 are control gains. The target yaw rate YRtgt is set so that the vehicle can travel along the target travel line Ld.

[0159] YRtgt=K1×Dc+K2×θy+K3×ν…(1)

[0160] Based on the target yaw rate YRtgt and the actual yaw rate YRa, the CPU calculates the target steering torque Trtgt for achieving the target yaw rate YRtgt. More specifically, the ECU 10 pre-stores the relationship between the target yaw rate YRtgt, the actual yaw rate YRa, the vehicle speed, and the target steering torque Trtgt in the form of a lookup table. The CPU calculates the target steering torque Trtgt by applying the target yaw rate YRtgt, the actual yaw rate YRa, and the vehicle speed SPD obtained above to this table. The driving assistance ECU 10 then controls the steering motor 52 using the steering ECU 50 so that the actual steering torque Tra matches the target steering torque Trtgt. This is an overview of lane keeping control.

[0161] Next, the CPU proceeds to step 1140 to determine whether a lane keeping control termination condition is satisfied. The lane keeping control termination condition is satisfied, for example, when the lane keeping control termination is selected by operating the operating switch 18 .

[0162] If the lane keeping control termination condition is not met, the CPU determines "No" in step 1140 and proceeds directly to step 1195 to temporarily terminate this routine. In contrast, if the lane keeping control termination condition is met, the CPU determines "Yes" in step 1140 and proceeds to step 1150. Then, in step 1150, the CPU sets the value of the lane keeping control permission flag XLTA to "0." Thereafter, the CPU proceeds to step 1195 to temporarily terminate this routine.

[0163] On the other hand, when the CPU proceeds to step 1120, if the control limit condition for lane keeping control is met, the CPU makes a "yes" determination in step 1120 and proceeds to step 1160. In step 1160, the CPU temporarily suspends (i.e., interrupts or cancels) lane keeping control. Thereafter, the CPU proceeds to step 1140.

[0164] As described above, when a temporary abnormality determination is made, the first device slowly decelerates the vehicle at the minimum deceleration DGmin. When a confirmed abnormality determination is made in this state, the first device decelerates the vehicle at a "normal deceleration DGnor that is greater than the minimum deceleration DGmin." However, if it is predicted that the control limit of lane keeping control will be exceeded before the vehicle stops if the vehicle is decelerated at the normal deceleration DGnor from the time the abnormality determination is made, the first device decelerates the vehicle at a "maximum deceleration DGmax that is greater than the normal deceleration DGnor." Regardless of whether the control limit of lane keeping control is reached and lane keeping control is actually temporarily stopped (canceled), vehicle deceleration control is performed according to one of the minimum deceleration DGmin, normal deceleration DGnor, and maximum deceleration DGmax.

[0165] This avoids the situation where, while the driver has determined an abnormality, the vehicle enters a curve from a straight road, the lane keeping control limit is reached, lane keeping control is canceled, and the vehicle deceleration control based on the abnormality determination is stopped as a result of the cancellation of lane keeping control. Furthermore, when the lane keeping control limit is predicted to be reached, the vehicle is decelerated at the maximum deceleration rate DGmax, increasing the likelihood of stopping the vehicle before entering the curve. Furthermore, even if the vehicle enters a curve and the lane keeping control limit is reached, the vehicle speed can be reduced sufficiently before that point.

[0166] <Modification of the First Embodiment>

[0167] The CPU of the driving assistance ECU 10 according to this modification is Figure 8 In step 850 , when at least one of the following conditions C1 and D1 is satisfied, it is determined that “the control limit condition of the lane keeping control is satisfied on the curved road that the vehicle is predicted to enter”.

[0168] (Condition C1) The lateral acceleration of the vehicle predicted on the curved road that the vehicle is predicted to enter is equal to or greater than the control limit lateral acceleration Gyth.

[0169] (Condition D1) The curvature radius of the curved road that the vehicle is predicted to enter is less than or equal to the control limit radius threshold Rltth. The control limit radius threshold Rltth is set to a value indicating that the curved road is a sharp turn to the extent that the white line near the vehicle is not included in the image data obtained by the camera of the camera device 17b (that is, the white line near the vehicle is outside the camera's imaging range).

[0170] Furthermore, the CPU of the driving assistance ECU 10 according to this modification example is Figure 11 In step 1120 , when at least one of the following conditions C2 and D2 is satisfied, it is determined that the control limit condition of the lane keeping control is actually satisfied.

[0171] (Condition C2) The actual lateral acceleration Gy is equal to or greater than the control limit lateral acceleration Gyth.

[0172] (Condition D2) The camera device 17b does not recognize at least one of “the left white line LL and the right white line LR” near the vehicle.

[0173] <Second embodiment>

[0174] The vehicle control device according to the second embodiment of the present invention (hereinafter sometimes referred to as the "second device") is designed based on the premise that the curvature of a curved road changes in the interval from the starting time point to the ending point of the curved road. The second device is executed only when the CPU of the driving assistance ECU 10 executes Figure 12 Instead of the routine shown in the flowchart Figure 8 The routine shown is different from the first device in this respect. The following description will focus on this difference.

[0175] When the predetermined timing comes, the CPU Figure 12 The process starts at step 1200 and proceeds to step 1210, where it is determined whether the current time point is immediately after the abnormality determination is made. In other words, the CPU determines whether the current time point is immediately after the abnormality determination flag XHijo changes from '0' to '1'.

[0176] If the current time point is not a time point immediately after the time point at which the abnormality determination is made, the CPU makes a “No” determination in step 1210 , directly proceeds to step 1295 , and temporarily ends this routine.

[0177] In contrast, if the current time point is immediately after the time point at which the abnormality determination was made, the CPU determines "yes" in step 1210 and proceeds to step 1220. In step 1220, the CPU determines whether the control limit condition for lane keeping control is satisfied before the vehicle stops, given that the vehicle has decelerated at a constant normal deceleration rate DGnor from the current speed point. In other words, the CPU determines whether lane keeping control is likely to be canceled (stopped) before the vehicle stops. The control limit condition for lane keeping control is satisfied, for example, when "the vehicle's lateral acceleration is at least the control limit lateral acceleration Gyth."

[0178] More specifically, the CPU calculates the "vehicle speed SPD(t) and the vehicle's position P(t)" after time t based on the vehicle speed SPDnow and the position Pnow at the current time, assuming that the vehicle has started decelerating at the normal deceleration DGnor from the vehicle speed at the current time point. Next, the CPU reads the curvature radius R(t) at the position P(t) from the map database 22 via the navigation ECU 20. Then, the CPU estimates the lateral acceleration Gy(t) of the vehicle after time t based on the vehicle speed SPD(t) and the curvature radius R(t), and determines whether the estimated lateral acceleration Gy(t) is greater than the control limit lateral acceleration Gyth. The CPU repeats the above determination while gradually increasing the time t from "0" by a small time Δt until the time t becomes "the time required for the vehicle to stop after decelerating at the normal deceleration DGnor."

[0179] If it is estimated that the lateral acceleration Gy(t) will not exceed the control limit lateral acceleration Gyth before the vehicle stops when decelerating at the normal deceleration DGnor (i.e., if it is estimated that lane keeping control will not reach its control limit), the CPU makes a "No" determination in step 1220 and proceeds to step 1230, where it sets the target deceleration DGtgt to the normal deceleration DGnor. The CPU then proceeds to step 1295 and temporarily terminates this routine.

[0180] In contrast, if it is estimated that the lateral acceleration Gy(t) will exceed the control limit lateral acceleration Gyth before the vehicle stops when decelerating at the normal deceleration DGnor (i.e., if it is estimated that lane keeping control will reach its control limit), the CPU makes a "yes" determination in step 1220 and proceeds to step 1240. In step 1240, the CPU sets the value of the target deceleration DGtgt to the maximum deceleration DGmax. The CPU then proceeds to step 1295 and temporarily terminates this routine.

[0181] As described above, when a temporary abnormality determination is made, the second device slowly decelerates the vehicle at the minimum deceleration DGmin. When a final abnormality determination is made in this state, the second device decelerates the vehicle at the normal deceleration DGnor. However, if it is predicted that the lane keeping control limit will be exceeded before the vehicle stops if the vehicle is decelerated at the normal deceleration DGnor from the time the final abnormality determination is made, the second device decelerates the vehicle at the maximum deceleration DGmax. Regardless of whether the lane keeping control limit is reached and the lane keeping control is actually temporarily stopped (canceled), the vehicle deceleration control is performed according to either the minimum deceleration DGmin, the normal deceleration DGnor, or the maximum deceleration DGmax. Furthermore, even if the curvature of the curved road changes between the start and end points of the curved road (for example, even if the section immediately after the entrance and the section immediately before the exit of the curved road are clothoid sections), the second device can accurately estimate whether the lane keeping control limit will be exceeded from the time the final abnormality determination is made until the vehicle stops.

[0182] <Modification of Second Embodiment>

[0183] The CPU of the driving assistance ECU 10 according to this modification is Figure 12 In step 1220 , when at least one of the following conditions C3 and D3 is satisfied, it is determined that the control limit condition of the lane keeping control is satisfied before the vehicle stops.

[0184] (Condition C3) When the vehicle is decelerated at a constant normal deceleration DGnor from the current vehicle speed, the predicted vehicle lateral acceleration will become equal to or greater than the control limit lateral acceleration Gyth before the vehicle stops.

[0185] (Condition D3) When the vehicle is decelerated at a constant normal deceleration rate DGnor from the current vehicle speed, there is a portion where the curvature radius becomes equal to or smaller than the control limit radius threshold Rltth before the vehicle stops.

[0186] In addition, the CPU of the driving assistance ECU 10 according to this modification example is Figure 11 In step 1120 , when at least one of the above-mentioned “condition C2 and condition D2” is satisfied, it is determined that the control limit condition of the lane keeping control is actually satisfied.

[0187] <Third embodiment>

[0188] A vehicle control device according to a third embodiment of the present invention (hereinafter sometimes referred to as a "third device") differs from the second device in that it operates as follows when the driving lane includes a steep uphill slope.

[0189] When the third device makes a temporary abnormality determination, the vehicle is decelerated slowly at the minimum deceleration DGmin (see Figure 13 However, when the vehicle speed SPD is reduced to the vehicle speed SPDth immediately before stopping and the vehicle is traveling on a steep uphill road, the third device maintains the vehicle speed at that time (refer to Figure 13 Afterwards, if the lane on which the vehicle is traveling is no longer a steep uphill road, the third device slowly decelerates the vehicle at the minimum deceleration DGmin until the vehicle stops (refer to Figure 13 Location P64 to location P65).

[0190] When an abnormality determination is made, the third device decelerates the vehicle at the normal deceleration rate DGnor. However, if it is predicted that the vehicle will exceed the lane keeping control limit before the vehicle stops if the vehicle is decelerated at the normal deceleration rate DGnor from the time the abnormality determination is made, the third device, like the second device, decelerates the vehicle at a "maximum deceleration rate DGmax greater than the normal deceleration rate DGnor." Furthermore, even if it is not predicted that the vehicle will exceed the lane keeping control limit before the vehicle stops if the vehicle is decelerated at the normal deceleration rate DGnor from the time the abnormality determination is made, if it is predicted that the vehicle will enter a steep uphill slope before the vehicle stops if the vehicle is decelerated at the normal deceleration rate DGnor from the time the abnormality determination is made, the third device determines whether the vehicle can stop before entering the steep uphill slope if the vehicle is decelerated at the maximum deceleration rate DGmax. The third device decelerates the vehicle at the maximum deceleration DGmax when the vehicle can stop before entering a steep uphill road if the vehicle is decelerated at the maximum deceleration DGmax (see Figure 14 Location P72 to location P73).

[0191] On the other hand, when it is not predicted that the control limit of the lane keeping control will be exceeded before the vehicle stops if the vehicle is decelerated at the normal deceleration DGnor from the time when the abnormality determination is made, and when it is predicted that the vehicle will enter a steep uphill road even if the vehicle is decelerated at the maximum deceleration DGmax from the time when the abnormality determination is made, the third device decelerates the vehicle at the normal deceleration DGnor (refer to Figure 15Furthermore, when the vehicle speed SPD is reduced to the vehicle speed SPDth immediately before stopping and the vehicle is traveling on a steep uphill road, the third device maintains the vehicle speed at that time (refer to Figure 15 Thereafter, if the lane on which the vehicle is traveling is no longer a steep uphill road, the third device decelerates the vehicle at the normal deceleration DGnor until the vehicle stops (refer to Figure 15 Location P85 to location P86).

[0192] (Specific work)

[0193] The third device is executed only by the CPU of the driving support ECU 10 Figure 16 Instead of the routine shown in the flowchart Figure 12 The routine shown here, and the execution Figure 17 Instead of the routine shown in the flowchart Figure 9 The routine shown is different from the second device in this respect. The following description will focus on this difference.

[0194] When the predetermined timing comes, the CPU Figure 16 The process starts from step 1600 and proceeds to step 1210 to determine whether the current time point is a time point immediately after the time point at which the abnormality determination is made. Figure 12 If the current time point is not a time point immediately after the time point at which the abnormality determination is made, the CPU determines "No" in step 1210, directly proceeds to step 1695 and temporarily ends this routine.

[0195] In contrast, when the current time point is a time point immediately after the time point at which the abnormality determination is made, the CPU Figure 16 In step 1210, if it is determined to be "yes", the process proceeds to Figure 16 Step 1220. In step 1220, the CPU determines whether the control limit condition of the lane keeping control is satisfied before the vehicle stops when the vehicle is decelerated at a constant normal deceleration DGnor from the current vehicle speed. Figure 12 The same steps as step 1220.

[0196] When it is estimated that the lane keeping control will reach its control limit, the CPU Figure 16 In step 1220, if it is determined to be "yes", the process proceeds to Figure 16 In step 1240, the value of the target deceleration DGtgt is set to the maximum deceleration DGmax. Thereafter, the CPU proceeds to step 1695 and temporarily terminates this routine.

[0197] On the other hand, when it is estimated that the lane keeping control will not reach its control limit, the CPU Figure 16 A "No" determination is made in step 1220, and the process proceeds to step 1610. In step 1610, the CPU determines whether the lane in which the vehicle was traveling (i.e., the driving lane) before the vehicle stopped would have changed to an "uphill road (steep uphill road) with an inclination angle of at least a predetermined angle" if the vehicle were decelerated at a constant normal deceleration rate DGnor from the current vehicle speed. Furthermore, the CPU obtains the inclination angle of the driving lane based on information obtained from the map database 22 via the navigation ECU 20.

[0198] If the lane in which the vehicle is traveling is expected to change to an "uphill road with an inclination angle of a predetermined angle or greater (a steep uphill road)", the CPU makes a "yes" determination in step 1610 and proceeds to step 1620. In step 1620, the CPU determines whether the vehicle can stop before the lane in which the vehicle is traveling changes to a steep uphill road by decelerating the vehicle at a constant maximum deceleration rate DGmax from the current vehicle speed.

[0199] If the vehicle can stop before the lane it is traveling in changes to a steep uphill slope, the CPU determines "yes" in step 1620 and proceeds to step 1240 to set the target deceleration DGtgt to the maximum deceleration DGmax. The CPU then proceeds to step 1695 to temporarily terminate this routine.

[0200] On the other hand, if the vehicle's lane does not change to a steep uphill slope when the vehicle is decelerated at a constant normal deceleration rate DGnor from the current vehicle speed, the CPU makes a "No" determination in step 1610 and proceeds to step 1230. In step 1230, the CPU sets the value of the target deceleration rate DGtgt to the normal deceleration rate DGnor. Thereafter, the CPU proceeds to step 1695 and temporarily terminates this routine.

[0201] Furthermore, if the vehicle's lane changes to a steep uphill slope when the vehicle is decelerated at a constant normal deceleration rate DGnor from its current speed, and if the vehicle cannot stop before the lane changes to a steep uphill slope even if the vehicle is decelerated at the maximum deceleration rate DGmax from its current speed, the CPU makes a "Yes" determination in step 1610 and a "No" determination in step 1620. The CPU then proceeds to step 1230 and sets the target deceleration rate DGtgt to the normal deceleration rate DGnor. The CPU then proceeds to step 1695 and temporarily terminates this routine.

[0202] When the predetermined timing comes, the CPU Figure 17The process begins at step 1700 and proceeds to step 1710, where it is determined whether either the value of the temporary abnormality determination flag XKijo or the value of the abnormality determination flag XHijo is "1." If both the value of the temporary abnormality determination flag XKijo and the value of the abnormality determination flag XHijo are "0," the CPU makes a "No" determination in step 1710, directly proceeds to step 1795, and temporarily terminates this routine.

[0203] On the other hand, when either the value of the temporary abnormality determination flag XKijo or the value of the abnormality final determination flag XHijo is “1”, the CPU makes a “Yes” determination at step 1710 and proceeds to step 1720 .

[0204] In step 1720, the CPU determines, based on the lane information, whether the lane currently being traveled is an "uphill road with an inclination angle of at least a predetermined angle (i.e., a steep uphill road)." If the lane currently being traveled is not a steep uphill road, the CPU determines "No" in step 1720 and proceeds to step 1730.

[0205] In step 1730, the CPU decelerates the vehicle so that the actual deceleration of the vehicle is consistent with the target deceleration DGtgt. Then, the CPU proceeds to step 1740 to issue an alarm to the inside and outside of the vehicle. Figure 9 The same process as step 930 (inside and outside vehicle alarm process) is performed. After that, the CPU proceeds to step 1795 and temporarily ends this routine.

[0206] On the other hand, when the CPU proceeds to step 1720, if the lane currently being traveled is a steep uphill road, the CPU makes a "yes" determination in step 1720 and proceeds to step 1750. In step 1750, the CPU determines whether the vehicle speed SPD is less than or equal to the vehicle speed SPDth immediately before stopping. If the vehicle speed SPD is not less than or equal to the vehicle speed SPDth immediately before stopping, the CPU makes a "no" determination in step 1750, performs the processes of steps 1730 and 1740, proceeds to step 1795, and temporarily terminates this routine.

[0207] In contrast, if vehicle speed SPD is less than or equal to vehicle speed SPDth immediately before stopping, the CPU determines "Yes" in step 1750 and proceeds to step 1760. In step 1760, the CPU controls vehicle speed SPD so that vehicle speed SPD remains at the current value. The CPU then performs the process in step 1740, proceeds to step 1795, and temporarily terminates this routine.

[0208] As a result, the vehicle travels at the vehicle speed just before stopping SPDth. Then, when the vehicle passes a steep uphill road, the CPU determines "No" in step 1720 and proceeds to step 1730. As a result, the vehicle is decelerated so that the actual deceleration of the vehicle matches the target deceleration DGtgt.

[0209] In this manner, the third device can prevent the vehicle from stopping on a steep uphill slope when either the value of the temporary abnormality determination flag XKijo or the value of the abnormality final determination flag XHijo is "1."

[0210] As described above, the vehicle control device involved in each embodiment and modified example of the present invention can decelerate and stop the vehicle at an appropriate deceleration rate corresponding to the determination result of the driver's state (i.e., whether it is in a temporary abnormality determination state or a definite abnormality determination state) even if the control limit of the lane keeping control is reached and the lane keeping control is stopped (canceled) in the case of a temporary abnormality determination and the case of a definite abnormality determination.

[0211] The present invention is not limited to the above-described embodiment and modifications, and various modifications can be adopted within the scope of the present invention.

[0212] For example, whether the driver is in an abnormal state can be determined by confirming whether the button 80 is operated. Figure 6 In step 640 , the meter display 64 is caused to display a “warning message urging the driver to operate the confirmation button 80 ”.

[0213] Furthermore, in this state, if the confirmation button 80 is not operated within the first time, the CPU determines that the driver may be in an abnormal state (i.e., performs a temporary abnormality determination). Further, thereafter, if the confirmation button 80 is not operated within the second time, the CPU determines that the driver is in an abnormal state (i.e., performs an abnormality determination). In addition, in this case, if the confirmation button 80 is operated before the first time and before the second time, the CPU proceeds to the Figure 6 Steps 615 and 620 are performed. In this manner, the signal from the confirmation button 80 functions as a driver state parameter indicating the state of the driver of the vehicle.

[0214] As another variation, the so-called "driver monitoring technology" disclosed in Japanese Patent Application Laid-Open No. 2013-152700 can be used to determine whether the driver is in an abnormal state. More specifically, in this variation, a camera installed in a component within the vehicle cabin (e.g., a steering wheel or a pillar) is used to capture an image of the driver, and the captured image is used to monitor the direction of the driver's gaze and / or the orientation of his or her face.

[0215] Furthermore, this variation sets the value of the temporary abnormality determination flag XKijo to "1" when the driver's gaze or facial orientation continues for a temporary abnormality determination threshold time TKijoth in a direction not typically faced during normal vehicle driving. Furthermore, this variation sets the value of the temporary abnormality determination flag XKijo to "0" and the value of the final abnormality determination flag XHijo to "1" when the driver's gaze or facial orientation continues for a final abnormality determination threshold time THijoth in a direction not typically faced during normal vehicle driving. In this manner, the driver's gaze or facial orientation functions as a driver status parameter indicating the driver's state in the vehicle.

[0216] The above-mentioned embodiment and modification examples perform temporary abnormality determination and abnormality final determination during the execution of lane keeping control, but temporary abnormality determination and abnormality final determination may be performed regardless of whether lane keeping control is being executed. In this case, Figure 6 Step 610 is omitted, and the CPU proceeds to step 625 when it is determined to be "yes" in step 605. Further, in this case, the CPU Figure 10 In step 1010 , not only when all of the above conditions A1 to A4 are satisfied, but also when the following condition A5 and all of the above conditions A2 to A4 are satisfied, it is determined that the lane keeping control start permission condition is satisfied.

[0217] (Condition A5) At least one of the value of the temporary abnormality determination flag XKijo and the value of the abnormality final determination flag XHijo is "1".

[0218] Furthermore, in the above-described embodiment and variations, when the value of the temporary abnormality determination flag XKijo changes from "0" to "1," if it is determined that the vehicle would enter the prohibited vehicle entry zone if the vehicle were decelerated at the minimum deceleration DGmin, the vehicle may be decelerated at the maximum deceleration DGmax. Furthermore, the CPU may acquire position information regarding the prohibited entry zone based on information acquired using the navigation ECU 20 and a communication device (not shown).

Claims

1. A vehicle control device comprising: a demarcation line information acquisition device comprising a camera that captures image data of a front portion of a vehicle, and acquires demarcation line information based on the image data, the demarcation line information including information about demarcation lines that demarcate a lane in which the vehicle is traveling, i.e., a driving lane, and information indicating a positional relationship between the demarcation lines and the vehicle in a lane width direction; a vehicle speed changing actuator capable of changing the speed of the vehicle, i.e., the vehicle speed; a steering angle actuator capable of changing the steering angle of the vehicle; a driving state sensor capable of acquiring a driving state parameter representing a driving state of the vehicle; a driver state sensor that obtains a driver state parameter indicating a state of a driver of the vehicle; a position obtaining device for obtaining a current time point position parameter indicating the current time point position of the vehicle; a lane information acquisition device that acquires lane information including parameters indicating a shape of the driving lane based on the position of the vehicle; as well as a control unit that executes lane keeping control for controlling the steering angle actuator based on the dividing line information so that the vehicle travels along the driving lane, and stops the execution of the lane keeping control if it is determined that a control limit condition predetermined for the lane keeping control is satisfied during the execution of the lane keeping control based on at least the driving state parameter, wherein: The control unit is configured as follows: determining whether an abnormality determination state has occurred based on the driver state parameter, which can be determined as the driver being in an abnormal state where the driver cannot drive the vehicle; When it is determined that the abnormal determination state has occurred, it is estimated based on the driving state parameter, the current time point position parameter, and the lane information whether a specific situation has occurred in which the control limit condition is satisfied before the vehicle stops when the vehicle is assumed to be decelerated at the first deceleration rate. When it is estimated that the specific situation has occurred, the vehicle speed change actuator is controlled so that the vehicle is decelerated at a second deceleration having an absolute value greater than the absolute value of the first deceleration. When it is estimated that the specific situation has not occurred, the vehicle speed change actuator is controlled so that the vehicle is decelerated at the first deceleration rate.

2. The vehicle control device according to claim 1, The control unit is configured as follows: Based on the driver state parameter, it is determined whether a temporary abnormal state has occurred, in which the driver may have fallen into the abnormal state but cannot be determined to have fallen into the abnormal determination state. When it is determined that the temporary abnormal state has occurred, the vehicle speed change actuator is controlled to decelerate the vehicle at a third deceleration having an absolute value less than or equal to the absolute value of the first deceleration from the time when the temporary abnormal state has been determined to have occurred.

3. The vehicle control device according to claim 1, The control unit is configured as follows: During execution of the lane keeping control, a determination is made as to whether the abnormality determination state has occurred.

4. The vehicle control device according to claim 2, The control unit is configured as follows: During execution of the lane keeping control, a determination is made as to whether the abnormality determination state has occurred and a determination is made as to whether the temporary abnormality state has occurred.

5. The vehicle control device according to claim 1, The control unit is configured as follows: Even if it is presumed that the specific condition has not occurred, when it is determined that the vehicle will enter an uphill road having an inclination angle greater than a predetermined angle in the driving lane before stopping when the vehicle is assumed to be decelerated at the first deceleration, and when it is determined that the vehicle can stop before entering the uphill road when the vehicle is assumed to be decelerated at the second deceleration, the vehicle speed change actuator is controlled so that the vehicle decelerates at the second deceleration.

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