Vehicle control device

Abstract

To provide a vehicle control device capable of reducing possibility that override control is mistakenly executed when a vehicle is predicted to collide with an obstacle.SOLUTION: An ECU executes automatic brake control while prohibiting override control in a case where a driver is determined to be in an abnormal state at a time when a collision prediction condition is met. The ECU also executes the override control while prohibiting the automatic brake control in a case where: the driver is determined not to be in the abnormal state at the time when the collision prediction condition is met; (1) an operation determination condition with an operator state parameter set to a first condition is met if the time is not in a transition period; and (2) the operation element state parameter satisfies "a second condition which is satisfied when possibility that the driver intentionally operates the operator is higher than when the first condition is met" if the time is in the transition period.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vehicle control device that executes automatic brake control (collision avoidance brake control or collision damage mitigation brake control) for avoiding a collision of a vehicle with an obstacle or for mitigating damage caused by a collision with an obstacle. [Background technology]

[0002] Conventionally, there is known a vehicle control device that detects an obstacle ahead of the vehicle and executes automatic brake control when it is predicted that the vehicle will collide with the obstacle. When it is predicted that the vehicle will collide with an obstacle and driving operations such as accelerator operation and / or steering operation by the driver are detected, one of such vehicle control devices (hereinafter referred to as a "conventional device") judges whether or not the driving operations are erroneous. If it is determined that the driving operations are not erroneous, the conventional device does not execute automatic brake and prioritizes the driving operations by the driver. In other words, the conventional device allows override control. In contrast, if it is determined that the driving operations are erroneous, the conventional device prohibits override control and executes automatic brake control (see, for example, Patent Document 1).

[0003] Furthermore, a device has been developed that determines whether or not a driver is in a state in which he or she is unable to drive a vehicle (hereinafter referred to as an "abnormal state"), and controls the vehicle when such a determination is made (see, for example, Patent Document 2). When a driver is in an abnormal state, the driver loses the ability to drive a vehicle, for example, when the driver is in a state of drowsiness while driving or in a state of mental and physical dysfunction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-121534 A [Patent Document 2] JP 2017-190048 A Summary of the Invention

[0005] However, when it is predicted that the vehicle will collide with an obstacle, if it is determined that the driver is in an abnormal state, even if a driving operation by the driver is detected, the driving operation may be determined to be an erroneous operation. Therefore, in such a case, it is preferable to prohibit the override control.

[0006] However, when it is determined that the driver has returned to a normal state after it has been determined that the driver is in an abnormal state, there is a high possibility that the driver's driving operation is an erroneous operation for a certain period of time from that point (hereinafter referred to as the "transient period"). This is because the determination that the driver has returned to a normal state is not necessarily correct. For this reason, there is a risk that the override control will be erroneously executed during the transition period.

[0007] The present invention has been made to solve the above problems. That is, one of the objects of the present invention is to provide a vehicle control device that can reduce the possibility of erroneously executing override control when it is predicted that the vehicle will collide with an obstacle during a period from when it was determined that the driver was in an abnormal state to when it is determined that the driver is no longer in an abnormal state.

[0008] One aspect of the vehicle control device of the present invention is to an obstacle sensor (17a, 17b) for acquiring information about an obstacle present in the traveling direction of the vehicle; A driver state sensor (11, 12, 13, 14, 15, 70) for acquiring a driver state parameter representing a state of a driver of the vehicle; a driving operator state sensor (11, 14, 15) for acquiring an operator state parameter representing a state of a driving operator (e.g., an accelerator pedal, a steering wheel, etc.) of the vehicle operated by the driver; It is determined whether or not a collision prediction condition that is established when it is predicted that the vehicle will collide with the obstacle based on information from the obstacle sensor is established (step 210, step 320); It is determined whether the driver is in an abnormal state in which the driver is unable to drive the vehicle based on the driver state parameters (steps 220, 520, 550, and 580). When it is determined that the collision prediction condition is satisfied (step 210: Yes, step 320: Yes), When it is determined that the driver is in the abnormal state (step 220: No, step 410, step 420, step 330: Yes), regardless of whether the driver is operating the driving operation control, an automatic brake control is executed to apply a braking force to the vehicle by a braking device provided in the vehicle without requiring the driver to operate the brake (step 270, step 340). When it is determined that the driver is not in the abnormal state (step 220: Yes, step 410, step 430, step 330: No), if the operator state parameter satisfies the operation determination condition (step 250: Yes, step 350: Yes), an override control is executed that prioritizes the driving of the vehicle based on the operation of the driving operator without executing the automatic brake control (step 260, step 360). A control unit (20) configured as described above; Equipped with.

[0009] Furthermore, the control unit (20) When it is determined that the collision prediction condition is satisfied, it is determined that the driver is not in the abnormal state (step 220: Yes, step 330: No), If the transition period starts when it is determined that the driver is not in the abnormal state in the state where it was determined that the driver is in the abnormal state, and ends when a predetermined time has elapsed from the start time (i.e., the transition period is within a predetermined time from when it is determined that the driver is not in the abnormal state in the state where it was determined that the driver is in the abnormal state) (step 230: Yes, step 440: No), a first condition that is satisfied by the operator state parameter when the driving operator is being operated is adopted as the operation determination condition (step 240, step 450); If it is within the transition period (step 230: No, step 440: Yes), a second condition that is satisfied by the operator state parameter when the likelihood that the driving operator is being operated based on the driver's will is higher than when the first condition is satisfied is adopted as the operation determination condition (step 280, step 460). It is structured as follows.

[0010] The operation determination condition is, for example, a condition that is met when the magnitude |X| of the control state parameter X is equal to or greater than a “magnitude threshold value Xth.” In this example, the first condition is an operation determination condition when the magnitude threshold value Xth is set to a first threshold value, and the second condition is an operation determination condition when the magnitude threshold value Xth is set to a “second threshold value greater than the first threshold value.” The operation determination condition is, for example, a condition that is met when the magnitude of the amount of change per unit time of the control state parameter X, |dX|, is equal to or greater than a "change rate threshold dXth." In this example, the first condition is an operation determination condition when the change rate threshold dXth is set to a first change rate threshold, and the second condition is an operation determination condition when the change rate threshold dXth is set to a "second change rate threshold greater than the first change rate threshold."

[0011] In other words, the second condition can be said to be a condition that is met when the driving operator is operated to a greater extent and / or faster than when the first condition is met.

[0012] This vehicle control device, if it is determined that the driver is in an abnormal state at the time when the collision prediction condition is satisfied, prohibits override control and executes automatic brake control. Therefore, when the driver is in an abnormal state, automatic brake control can be reliably executed regardless of whether the driving operator is being operated.

[0013] Furthermore, when the vehicle control device determines that the driver is not in an abnormal state at the time when the collision prediction condition is established, (1) If the time point is not a transition period, when the operator state parameter satisfies the operation determination condition set in the first condition, the automatic brake control is prohibited and override control is executed; (2) If that point is a transitional period, when the operator state parameter satisfies the operation determination condition set to "the second condition that is met when there is a high probability that the driving operator has been operated by the driver's will compared to when the first condition was met," automatic brake control is prohibited and override control is executed.

[0014] Therefore, the possibility that override control will be erroneously executed in the period immediately after it is determined that the driver has recovered from the abnormal state can be reduced.

[0015] In the above description, in order to facilitate understanding of the present invention, the names and / or symbols used in the embodiments described below are enclosed in parentheses with respect to the configuration of the invention corresponding to the embodiments. However, each component of the present invention is not limited to the embodiments defined by the names and / or symbols. [Brief description of the drawings]

[0016] [Figure 1] 1 is a schematic configuration diagram of a vehicle control device (embodiment device) according to an embodiment of the present invention. [Diagram 2] 4 is a conceptual flowchart for explaining the operation of the embodiment of the present invention. [Diagram 3] 2 is a flowchart showing a routine executed by a CPU of a vehicle control ECU shown in FIG. 1. [Figure 4] 2 is a flowchart showing a routine executed by a CPU of a vehicle control ECU shown in FIG. 1. [Diagram 5] 2 is a flowchart showing a routine executed by a CPU of a vehicle control ECU shown in FIG. 1. [Figure 6] 2 is a flowchart showing a routine executed by a CPU of a vehicle control ECU shown in FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] <Configuration> A vehicle control device according to an embodiment of the present invention (hereinafter referred to as "this embodiment device") is applied to a vehicle (hereinafter sometimes referred to as "host vehicle" in order to distinguish it from other vehicles).

[0018] As shown in FIG. 1, the embodiment of the device 10 includes a vehicle control (driving assistance) ECU 20, a power train ECU 30, a brake ECU 40, a steering ECU 50, and a meter ECU 60.

[0019] These ECUs are electronic control units that include a microcomputer as a main component, and are connected to each other via a controller area network (CAN) so that they can transmit and receive information. In this specification, the microcomputer includes a CPU, a ROM, a RAM, a non-volatile memory, and an interface I / F. The CPU realizes 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 may be integrated into one ECU.

[0020] The vehicle control ECU 20 is connected to the sensors (including switches) listed below and receives detection signals or output signals from these sensors. Each sensor may be connected to an ECU other than the vehicle control ECU 20. In this case, the vehicle control ECU 20 receives the detection signal or output signal of the sensor from the ECU to which the sensor is connected via the CAN.

[0021] The accelerator pedal operation amount sensor 11 detects the operation amount (accelerator opening) of an accelerator pedal 11a of the vehicle, which is a driving operator, and outputs a signal indicative of the accelerator pedal operation amount AP. The brake pedal operation amount sensor 12 detects the operation amount of a brake pedal 12a of the vehicle, and outputs a signal indicative of the brake pedal operation amount BP.

[0022] The touch sensor 13 outputs a high-level signal when the driver is touching a steering wheel SW, which is a driving operator, and outputs a low-level signal when the driver is not touching the steering wheel SW. The steering angle sensor 14 detects the steering angle of the steering wheel SW and outputs a signal indicative of the steering angle θ. The steering torque sensor 15 detects the steering torque applied to the steering shaft US of the vehicle by the operation of the steering wheel SW, and outputs a signal indicative of the steering torque Tra. The vehicle speed sensor 16 detects the traveling speed (vehicle speed) of the vehicle, and outputs a signal indicative of the vehicle speed SPD.

[0023] The radar sensor 17a is configured to obtain information (hereinafter referred to as "radar target information") about a three-dimensional object (target) existing on the road ahead of the vehicle, using radio waves in the millimeter wave band.

[0024] The camera sensor device 17b includes a "camera and an image processing unit" (both not shown). The camera captures the scenery ahead of the vehicle to obtain image data. The image processing unit obtains information about a three-dimensional object existing on the road ahead of the vehicle (hereinafter referred to as "camera target information") based on the image data captured by the camera.

[0025] The vehicle control ECU 20 calculates integrated target information by integrating the radar target information and the camera target information. The integrated target information includes the distance Dfx(n) from the vehicle, the relative speed Vfx(n), and the direction H(n) of a three-dimensional object (target (n)) existing on the road ahead of the vehicle. Thus, the radar sensor 17a and the camera sensor device 17b constitute an "obstacle sensor that obtains information on obstacles existing around the vehicle."

[0026] The yaw rate sensor 18 detects the yaw rate of the vehicle and outputs an actual yaw rate YRa.

[0027] The accelerator pedal operation amount sensor 11, the steering angle sensor 14, the steering torque sensor 15, etc. also function as driving operator state sensors that acquire operator state parameters that indicate the state of the driving operators of the vehicle. The accelerator pedal operation amount sensor 11, the brake pedal operation amount sensor 12, the touch sensor 13, the steering angle sensor 14, the steering torque sensor 15, etc. also serve as driver state sensors that acquire driver state parameters that indicate the state of the driver of the vehicle. The vehicle speed sensor 16, the yaw rate sensor 18, etc. also serve as driving condition sensors that acquire driving condition parameters that indicate the driving condition of the vehicle.

[0028] 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. When the powertrain ECU 30 has not received an output suppression command from the vehicle control ECU 20, the powertrain ECU 30 controls the powertrain actuator 31 to change the driving force so that the driving force transmitted to the driving wheels of the vehicle increases as the accelerator pedal operation amount AP increases.

[0029] 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 provided on each wheel of the vehicle to change the braking force (friction braking force) applied to the vehicle. The brake actuator 41 and the friction brake device 42, together with the brake ECU 40, constitute a braking device capable of applying a braking force to the vehicle.

[0030] The steering ECU 50 is a control device for a well-known electric power steering system, and is connected to a motor drive circuit 51. The motor drive circuit 51 is connected to a steering motor 52. The steering motor 52 is incorporated in a "steering mechanism including a steering wheel US, a steering shaft connected to the steering wheel, a steering gear mechanism, and the like." The steering motor 52 generates torque using electric power supplied from the motor drive circuit 51, and this torque can change the steering angle of the left and right steered wheels (i.e., the steering angle of the vehicle). The motor drive circuit 51 and the steering motor 52, etc., constitute a steering angle actuator that can change the steering angle of the vehicle.

[0031] The meter ECU 60 is connected to a buzzer (cabin alarm sound generating device) 61, a warning display device 62 incorporated in the meter display, and the like, and is capable of controlling these devices.

[0032] Furthermore, the vehicle control ECU 20 is connected to a confirmation button 70. The confirmation button 70 is disposed in a position where it can be operated by the driver, and is configured to output a low level signal when not operated and to output a high level signal when pressed. The confirmation button 70 output signal is one of the driver state parameters.

[0033] (Overview of operation) The present embodiment device judges whether or not a collision prediction condition that is satisfied when it is predicted that the vehicle will collide with an obstacle is satisfied based on information from the obstacle sensor (integrated target information obtained based on radar target information and camera target information). That is, the present embodiment device judges whether or not a "collision possibility index value (time to collision TTC, described later) indicating the possibility that the vehicle will collide with an obstacle" calculated based on the integrated target information satisfies a predetermined collision prediction condition (TTC≦TTCth).

[0034] Furthermore, as described later, the present embodiment of the device determines whether or not the driver of the vehicle is in a "state in which the driver is unable to drive the vehicle (i.e., an abnormal state)" based on the driver state parameters.

[0035] As shown in the conceptual flowchart of FIG. 2, when it is determined that the collision prediction condition is met (step 210: Yes), the present implementation device executes either override control (step 260) or automatic brake control (step 270) depending on each of the following states.

[0036] The automatic brake control is a control that automatically applies a braking force to the vehicle by a braking device so as to avoid the vehicle colliding with an obstacle or to reduce damage caused by the collision, without requiring the driver to apply the brakes. The automatic brake control may be called a collision avoidance brake control or a collision damage mitigation brake control. The automatic brake control itself is well known, so a description thereof will be omitted. Note that, during the execution of the automatic brake control, even if the accelerator pedal operation amount AP changes, the present embodiment device controls the powertrain actuator 31 so that the driving force transmitted to the driving wheels of the vehicle is equal to or less than the creep force.

[0037] The override control is a control that prohibits (does not execute) the automatic brake control and changes the vehicle's running state based on the operation of the driver's driving operators (e.g., the accelerator pedal 11a and the steering wheel switch, etc.). In other words, the override control can be said to be a control that leaves the driving of the vehicle to the driver.

[0038] (State 1) When the driver is judged to be in an abnormal state If condition 1 occurs (step 220: No), the present implementation device prohibits override control and executes automatic brake control (step 270), regardless of whether the driver is operating the driving operator (i.e., regardless of the value of the operator state parameter).

[0039] (State 2) When it is determined that the driver is not in an abnormal state When state 2 occurs (step 220: Yes), if the control state parameters satisfy a predetermined operation determination condition (step 250: Yes), the present implementation device executes override control without executing automatic brake control (step 260). On the other hand, if the control state parameters do not satisfy the operation determination condition (step 250: No), the present implementation device prohibits override control and executes automatic brake control (step 270).

[0040] The operation determination condition is a condition that is satisfied by the operator state parameter when the driving operator is operated in a predetermined manner. For example, when the driving operator is a steering wheel SW, the operation determination condition is satisfied when the magnitude |θ| of the steering angle θ is equal to or greater than a threshold steering angle θth and the magnitude |dθ| of the change rate of the steering angle is equal to or greater than a threshold steering angle change rate dθth. Note that the operation determination condition is not limited to the above conditions. Generally speaking, the operation determination condition is satisfied when the magnitude |X| of the operator state parameter X is equal to or greater than a "magnitude threshold Xth" and / or when the magnitude |dX| of the change amount per unit time of the operator state parameter X is equal to or greater than a "change rate threshold dXth".

[0041] This operation determination condition is set to a different condition (i.e., either a first condition or a second condition described later) depending on whether the time when it is determined that the collision prediction condition is satisfied is within a "transition period". More specifically, the value of the "magnitude threshold value Xth" and / or the "change speed threshold value dXth" is changed depending on whether the time when it is determined that the collision prediction condition is satisfied is within a "transition period".

[0042] Here, the transition period is a period starting from the time when the device determines that the driver is not in an abnormal state after determining that the driver was in an abnormal state (the return determination time) and ending from the time when a predetermined time has elapsed from the start time (i.e., a period within a predetermined time from the return determination time). In other words, when it is determined that the driver is in an abnormal state and then it is determined that the driver is not in an abnormal state, the period from that time to the time when a predetermined time has elapsed is the transition period. Note that if the driver has never been determined to be in an abnormal state since the start of the current drive of the vehicle, there is no time when it is determined that the driver is no longer in an abnormal state, and therefore the time when it is determined that the collision prediction condition is satisfied is not determined to be within the "transition period".

[0043] (State 2-A) When the collision prediction condition is not met within the transition period In this case, the present implementation device adopts a first condition (i.e., a driver normal condition) that is satisfied by the operator state parameter when the driving operator is being operated as the operation determination condition (step 240). For example, when the driving operator is the steering wheel SW, the first condition is a condition that is met when the magnitude |θ| of the steering angle θ is equal to or greater than the "normal threshold steering angle θNormal set as the threshold steering angle θth" and the magnitude |dθ| of the rate of change of the steering angle is equal to or greater than the "normal threshold steering angle change rate dθNormal set as the threshold steering angle change rate dθth".

[0044] (State 2-B) When the collision prediction condition is met within the transition period In this case, the present implementation apparatus adopts, as the operation determination condition, a second condition (i.e., a condition for a transient period after the driver returns to normal) that is satisfied by the operator state parameter when it is more certain (more likely) that the driving operator is being operated based on the driver's will than when the first condition is satisfied (step 280). For example, when the driving operator is the steering wheel SW, the second condition is a condition that is satisfied when the magnitude |θ| of the steering angle θ is equal to or greater than a "transient threshold steering angle θLarge larger than a normal threshold steering angle θNormal" set as the threshold steering angle θth, and the magnitude |dθ| of the rate of change of the steering angle is equal to or greater than a "transient threshold steering angle change rate dθLarge larger than a normal threshold steering angle change rate dθNormal" set as the threshold steering angle change rate dθth.

[0045] According to the present embodiment, even if it is determined that the driver is not in an abnormal state, if the collision prediction condition is satisfied within the transition period, the second condition is adopted as the operation determination condition instead of the first condition. Therefore, when it is highly likely that the driving operator is being operated based on the driver's will, the override control is executed, and when it is doubtful whether the driving operator is being operated based on the driver's will, the override control is prohibited and the automatic brake control is executed.

[0046] (Specific operation) Next, the operation of the CPU of the ECU 20 according to the present embodiment will be described. The CPU executes each of the routines shown in the flowcharts of Fig. 3 to Fig. 6 every time a predetermined time elapses.

[0047] 1. Execution of automatic brake control or override control At an appropriate time, the CPU starts the process from step 300 in FIG. 3, proceeds to step 310, and determines whether or not an obstacle is present in the traveling direction of the vehicle (in this case, ahead of the vehicle).

[0048] More specifically, the CPU first obtains a predicted vehicle travel path Ehv, which is a future path of the vehicle that is predicted to pass through (the center position of the leading end of the vehicle in the vehicle width direction) in a predetermined estimation period, assuming that the vehicle maintains the current "steering angle θ (or yaw rate Yr) and vehicle speed SPD."

[0049] Next, the CPU determines a line obtained by moving the predicted vehicle travel path Ehv to the left in the vehicle width direction by a distance d as a left front end movement path SL, and determines a line obtained by moving the predicted vehicle travel path Ehv to the right in the vehicle width direction by a distance d as a right front end movement path SR. In this manner, a belt-shaped host vehicle passing area SP determined by the left front end movement path SL and the right front end movement path SR is estimated. Then, the CPU determines whether or not an obstacle is present in the host vehicle passing area SP based on information from the obstacle sensor (integrated target information). If no obstacle is present in the host vehicle passing area SP, the CPU determines "No" in step 310, proceeds directly to step 395, and ends this routine for the time being.

[0050] If an obstacle is present within the vehicle passing area SP, the CPU judges "Yes" in step 310 and proceeds to step 320 to judge whether a collision prediction condition that is satisfied when it is predicted that the vehicle will collide with the obstacle based on the integrated target information is satisfied. More specifically, the CPU calculates the collision margin time TTC by dividing the distance Dfx(n) between the obstacle and the vehicle by the relative speed Vfx(n) of the obstacle. Then, the CPU judges whether the collision margin time TTC is equal to or less than the threshold collision time TTCth, thereby judging whether the collision prediction condition is satisfied. The collision margin time TTC is a collision possibility index value that indicates the possibility that the vehicle will collide with the obstacle. The collision possibility index value may be a value that monotonically decreases or increases as the possibility of the vehicle colliding with the obstacle increases, and may be, for example, the reciprocal of the collision margin time TTC.

[0051] If the collision prediction condition is not satisfied, the CPU makes a "No" determination in step 320, proceeds directly to step 395, and ends this routine for the time being.

[0052] On the other hand, if the collision prediction condition is met, the CPU determines "Yes" in step 320 and proceeds to step 330. In step 330, the CPU determines whether the value of the override prohibition flag (hereinafter referred to as the "OR prohibition flag") XORpr is "1".

[0053] The value of the OR prohibition flag XORpr is set to "0" by an initialization routine (not shown) executed by the CPU when the vehicle's ignition key switch (not shown) is changed from the OFF position to the ON position. Furthermore, the value of the OR prohibition flag XORpr is set to "1" or "0" by a routine shown in Fig. 4 (to be described later). As will be described later, when the value of the OR prohibition flag XORpr is "1", override control is prohibited.

[0054] If the value of the OR prohibition flag XORpr is "1", the CPU judges "Yes" in step 330 and proceeds to step 340. The CPU prohibits override control in step 340 and executes automatic brake control. At this time, the CPU sends an output suppression command to the powertrain ECU 30. As a result, even if the accelerator pedal operation amount AP changes, the powertrain ECU 30 maintains the driving force transmitted to the driving wheels of the vehicle at or below the creep force. After that, the CPU proceeds to step 395 and temporarily ends this routine. That is, in this case, the automatic brake control is executed regardless of the value of the operator state parameter (even if the driving operator is operated).

[0055] On the other hand, if the value of the OR prohibition flag XORpr is "0" when the CPU proceeds to step 330, the CPU determines "No" in step 330 and proceeds to step 350. In step 350, the CPU determines whether or not the operation determination condition described below is satisfied. The operation determination condition is also called an override control permission condition.

[0056] The operation determination condition is a condition that satisfies at least one of the following conditions 1 and 2. That is, when at least one of the conditions 1 and 2 is satisfied, the CPU determines that the operation determination condition is satisfied.

[0057] Condition 1: Accelerator pedal operation amount AP≧threshold accelerator pedal operation amount APth and Accelerator pedal change speed dAP≧threshold pedal change speed dAPth Condition 2: Steering angle magnitude |θ|≧threshold steering angle θth and The magnitude of the change rate of the steering angle |dθ| ≧ threshold steering angle change rate dθth The accelerator pedal change rate dAP is the amount of increase in the accelerator pedal operation amount AP per unit time. The magnitude of the change rate of the steering angle |dθ| is the magnitude of the change amount of the steering angle per unit time. The threshold values ​​(APth, dAPth, θth, dθth) used in Condition 1 and Condition 2 are changed (set) by the routine shown in FIG. 4, which will be described later (see step 450 and step 460).

[0058] If the operation determination condition is satisfied, the CPU determines "Yes" in step 350 and proceeds to step 360. The CPU executes override control without executing automatic brake control in step 360. That is, the CPU controls the vehicle's running state by prioritizing the operation of the driving operator by the driver. At this time, the CPU does not send an output suppression command to the powertrain ECU 30. As a result, the powertrain ECU 30 changes the driving force transmitted to the driving wheels of the vehicle according to the accelerator pedal operation amount AP. After that, the CPU proceeds to step 395 and temporarily ends this routine.

[0059] On the other hand, if the operation determination condition is not satisfied, the CPU determines "No" in step 350 and proceeds to step 340. Therefore, in this case, the CPU prohibits the override control and executes the automatic brake control. After that, the CPU proceeds to step 395 and ends this routine.

[0060] 2. Setting the override prohibition flag and threshold (operation judgment condition) At an appropriate timing, the CPU starts the process from step 400 in Fig. 4 and proceeds to step 410 to determine whether or not it is determined that the driver is in an abnormal state (i.e., whether or not the value of an abnormality determination flag Xijo, which will be described later, is "1"). The determination of whether or not the driver is in an abnormal state is performed separately by the routines shown in Figs. 5 and 6, which will be described later.

[0061] If it is determined that the driver is in an abnormal state (if the value of the abnormality determination flag Xijo is "1"), the CPU determines "Yes" in step 410 and proceeds to step 420. The CPU sets the value of the OR prohibition flag XORpr to "1" in step 420, proceeds directly to step 495, and ends this routine for the time being. Therefore, in this case, override control is prohibited.

[0062] On the other hand, if it is not determined that the driver is in an abnormal state (the value of the abnormality determination flag Xijo is "0"), the CPU determines "No" in step 410 and proceeds to step 430. The CPU sets the value of the OR prohibition flag XORpr to "0" in step 430 and proceeds to step 440.

[0063] In step 440, the CPU determines whether the current time is within a transition period (i.e., a period within a predetermined time from the point at which the driver is determined to be in the abnormal state and then re-determined to be not in the abnormal state). More specifically, the CPU determines whether a predetermined time has elapsed since the value of the abnormality determination flag Xijo changed from "1" to "0". Note that if the value of the abnormality determination flag Xijo has never become "1" during the current operation of the vehicle (the state in which the ignition key switch is kept in the on position after being changed from the off position to the on position), the CPU determines that the current time is not within a transition period.

[0064] If the current time is not within the transition period, the CPU determines "No" in step 440 and proceeds to step 450. In step 450, the CPU sets the operation determination condition to the first condition by setting each threshold value as described below. After that, the CPU proceeds to step 495 and ends this routine. Note that the CPU also performs the same process as step 450 in the above-mentioned initialization routine. Step 450 is a step (corresponding to step 240) for the CPU to adopt the above-mentioned first condition as the operation determination condition.

[0065] The CPU sets the threshold accelerator pedal operation amount APth to the normal threshold pedal operation amount APNormal. The CPU sets the threshold pedal change speed dAPth to a normal threshold pedal change speed dAPNormal. The CPU sets the threshold steering angle θth to the normal threshold steering angle θNormal. The CPU sets the threshold steering angle change rate dθth to a normal threshold steering angle change rate dθNormal.

[0066] On the other hand, if the current time is within the transition period, the CPU determines "Yes" in step 440 and proceeds to step 460. In step 460, the CPU sets the second condition as the operation determination condition by setting each threshold value as described below. After that, the CPU proceeds to step 495 and temporarily ends this routine. Step 460 is a step (corresponding to step 280) for the CPU to adopt the above-mentioned second condition as the operation determination condition.

[0067] The CPU sets the threshold accelerator pedal operation amount APth to "a transient threshold pedal operation amount APLarge that is greater than the normal threshold pedal operation amount APNormal." The CPU sets the threshold pedal change rate dAPth to "a transient threshold pedal change rate dAPLarge that is greater than the normal threshold pedal change rate dAPNormal." The CPU sets the threshold steering angle θth to a "transient threshold steering angle θLarge that is larger than the normal threshold steering angle θNormal." The CPU sets the threshold steering angle change rate dθth to a "transient threshold steering angle change rate dθLarge" that is greater than the normal threshold steering angle change rate dθNormal.

[0068] 3. Driver Abnormality Judgment At an appropriate timing, the CPU starts processing from step 500 in FIG. 5 and proceeds to step 510 to determine whether or not the driver is determined to be in an abnormal state (i.e., whether or not the value of the abnormality determination flag Xijo is "0").

[0069] The value of this abnormality determination flag Xijo is also set to "0" in the above-mentioned initialization routine. Furthermore, as described later, the value of the abnormality determination flag Xijo is set to "1" when it is determined that the driver of the vehicle is "in an abnormal state in which the driver is unable to drive the vehicle" (see step 590).

[0070] If the value of the abnormality determination flag Xijo is not "0" (if it is "1"), the CPU makes a "No" determination in step 510, proceeds directly to step 595, and temporarily ends this routine.

[0071] On the other hand, when the value of the flag Xijo is "0", the CPU judges "Yes" in step 510 and proceeds to step 520 to judge whether or not the current time is a no-operation state. The no-operation state is a state in which none of the parameters consisting of a combination of one or more of "accelerator pedal operation amount AP, brake pedal operation amount BP, steering torque Tra, and signal level of the touch sensor 13" by the driver changes between "a point in time a predetermined sampling time before the current time" and "the current time" (or a state in which each parameter does not change by more than the threshold value corresponding to each parameter).

[0072] If the vehicle is not currently in a non-operational driving state, the CPU determines "No" in step 520, sequentially performs the processes of "step 530 and step 540" described below, and then proceeds to step 595 to temporarily end this routine.

[0073] Step 530: The CPU sets the value of the abnormality determination timer Tijo to “0.” Note that the value of this abnormality determination timer Tijo is also set to “0” in the above-mentioned initialization routine. Step 540: The CPU sets the value of the abnormality determination flag Xijo to “0”.

[0074] In contrast, if the driving no-operation state occurs when the CPU proceeds to step 520, the CPU determines "Yes" in step 520 and proceeds to step 550. In step 550, the CPU increments 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.

[0075] Next, the CPU proceeds to step 560 and determines whether the value of the abnormality determination timer Tijo is equal to or 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 determines "No" in step 560 and proceeds directly to step 595 to temporarily end this routine.

[0076] On the other hand, if the value of the abnormality determination timer Tijo is equal to or greater than the warning start threshold time Tkeikoku, the CPU determines "Yes" in step 560 and proceeds to step 570. In step 570, the CPU transmits an instruction signal to the meter ECU 60, thereby causing the buzzer 61 to emit a warning sound, and causes the warning display device 62 to flash the "warning lamp" and display a warning message encouraging the driver to operate any one of the "accelerator pedal 11a, the brake pedal 12a, and the steering wheel switch."

[0077] Next, the CPU proceeds to step 580 and determines whether the value of the abnormality determination timer Tijo is equal to or greater than the abnormality determination threshold time Tijoth. The abnormality determination threshold time Tijoth is set to a time longer than the warning start threshold time Tkeikoku. If the value of the abnormality determination timer Tijo is less than the abnormality determination threshold time Tijoth, the CPU determines "No" in step 580 and proceeds directly to step 595 to temporarily end this routine.

[0078] On the other hand, if the value of the abnormality determination timer Tijo is equal to or greater than the abnormality determination threshold time Tijoth, the CPU determines "Yes" in step 580 and proceeds to step 590. In step 590, the CPU sets the value of the abnormality determination flag Xijo to "1". Then, the CPU proceeds to step 595 and temporarily ends this routine. That is, when the duration of the no-operation state continues for a time period equivalent to or greater than the abnormality determination threshold time Tijoth, the CPU determines that the driver is in an abnormal state in which he or she is unable to drive the vehicle.

[0079] 4. Driver normal return judgment 6, the CPU starts the process from step 600 and proceeds to step 610 to determine whether the value of the abnormality determination flag Xijo is "1." If the value of the abnormality determination flag Xijo is "0," the CPU determines "No" in step 610, proceeds to step 695, and ends this routine.

[0080] On the other hand, if the value of the abnormality determination flag Xijo is "1" (i.e., if it is determined that the driver is currently in an abnormal state), the CPU determines "Yes" in step 610 and proceeds to step 620. In step 620, the CPU determines whether or not the return condition is met. In this example, the return condition is a condition that is met when "the driver is not in a no-operation state." Note that the return condition may be another condition that is met when it is considered that the driver is no longer in an abnormal state, and may be a condition that is met when the driver operates the confirmation button 70, for example.

[0081] If the return condition is not satisfied, the CPU judges "No" in step 620, proceeds to step 695, and ends this routine.

[0082] On the other hand, if the return condition is satisfied, it can be determined that the driver's condition has changed from an abnormal state to a non-abnormal state. Therefore, if the return condition is satisfied, the CPU determines "Yes" in step 620, sequentially performs the processes of "steps 630 to 650" described below, and proceeds to step 695 to temporarily end this routine.

[0083] Step 630: The CPU sets the value of the abnormality determination timer Tijo to “0”. Step 640: The CPU sets the value of the abnormality determination flag Xijo to “0”. Step 650: The CPU stops the warning sound generated in step 570, and turns off the warning lamp and warning message.

[0084] As described above, when it is determined that the driver is in an abnormal state at the time when the collision prediction condition is satisfied, the present embodiment of the device prohibits override control and executes automatic brake control.

[0085] Furthermore, when the present embodiment device determines that the driver is not in an abnormal state at the time when the collision prediction condition is satisfied, (1) If the time point is not a transition period, when the operator state parameter satisfies the operation determination condition set in the first condition, the automatic brake control is prohibited and override control is executed; (2) If the time point is a transitional period, and the operator state parameter satisfies the operation determination condition set to "a second condition that is satisfied when there is a higher possibility that the driving operator has been operated by the driver's will compared to when the first condition is satisfied," the automatic brake control is prohibited and override control is executed, thereby reducing the possibility that the override control is executed erroneously.

[0086] The present invention is not limited to the above-described embodiment and modifications, and various modifications as described below can be adopted within the scope of the present invention.

[0087] <First Modification> The operation determination condition for which the success or failure is determined in step 350 may be a condition that satisfies any one of the following conditions 3 to 8. Furthermore, the operation determination condition for which the success or failure is determined in step 350 may be a condition that satisfies any two or more of the following conditions 3 to 8 simultaneously.

[0088] Condition 3: Accelerator pedal operation amount AP≧threshold accelerator pedal operation amount APth Condition 4: Accelerator pedal change speed dAP≧threshold pedal change speed dAPth Condition 5: Steering angle magnitude |θ| ≧ threshold steering angle θth Condition 6: The magnitude of the speed of change of the steering angle |dθ| ≧ Threshold speed of change of the steering angle dθth Condition 7: Magnitude of steering torque Tra |Tra| ≧ Threshold steering torque Trath Condition 8: The magnitude of the change rate of the steering torque Tra |dTra| ≧ threshold steering torque change rate dTrath

[0089] When condition 7 is used as a condition for satisfying the operation determination condition, the CPU sets the threshold steering torque Trath to the normal threshold steering torque TraNormal in step 450, and sets the threshold steering torque Trath to the "transient threshold steering torque TraLarge that is larger than the normal threshold steering torque TraNormal" in step 460.

[0090] When condition 8 is used as a condition for satisfying the operation determination condition, the CPU sets the threshold steering torque change rate dTrath to the normal threshold steering torque change rate dTraNormal in step 450, and sets the threshold steering torque change rate dTra to the "transient threshold steering torque change rate dTraLarge that is larger than the normal threshold steering torque change rate dTraNormal" in step 460.

[0091] <Second Modification> The CPU may determine whether the driver is in an abnormal state by adopting the so-called "driver monitor technology" disclosed in Japanese Patent Application Laid-Open No. 2013-152700 and the like. More specifically, a vehicle control device adopting the driver monitor technology photographs the driver using a driver monitor camera provided on a member inside the vehicle (e.g., a steering wheel SW and a pillar, etc.) and monitors the driver's line of sight or face direction using the photographed image. If the driver's line of sight or face direction continues to face a direction that is not faced for a long time during normal driving of the vehicle for a predetermined period of time or more, the CPU determines that the driver is in an abnormal state and sets the value of the flag Xijo to "1". In this way, the image information from the driver monitor camera functions as a driver state parameter that indicates the state of the driver of the vehicle. In this case, the return condition may be a condition that is satisfied when it is confirmed that the driver's line of sight or face direction changes frequently.

[0092] <Third Modification> The CPU may determine whether or not the driver is in an abnormal state by using the confirmation button 70. More specifically, the CPU causes the warning display device 62 to display a "warning message urging the driver to operate the confirmation button 70" in step 570 of Fig. 5.

[0093] When the confirmation button 70 is not operated for a first period of time in that state, the CPU determines that the driver is in an abnormal state and sets the value of the flag Xijo to "1." When the CPU confirms that the confirmation button 70 has been operated in step 520 of FIG. 5, the CPU proceeds to steps 530 and 540. In this way, the signal from the confirmation button 70 functions as a driver state parameter that indicates the state of the driver of the vehicle. In this case, the return condition may be a condition that is satisfied when the confirmation button 70 has been operated. [Explanation of symbols]

[0094] 10: This embodiment device, 11...accelerator pedal operation amount sensor, 11a...accelerator pedal, 12...brake pedal operation amount sensor, 12a...brake pedal, 13...touch sensor, 14...steering angle sensor, 15...steering torque sensor, 17a...radar sensor, 17b...camera sensor device, 20...vehicle control (driving assistance) ECU, 30...powertrain ECU, 31...powertrain actuator, 40...brake ECU, 41...brake actuator, 42...friction brake device, 50...steering ECU, 51...motor drive circuit, 52...steering motor, 60...meter ECU, SW...steering handle (steering wheel), Tijoth...abnormality determination threshold time, TTC...time to collision, TTCth...threshold collision time, AP...accelerator pedal operation amount, APth...threshold accelerator pedal operation amount, APNormal...normal threshold pedal operation amount, APLarge...transient threshold pedal operation amount, dAP...accelerator pedal change rate, dAPth...threshold pedal change rate, dAPNormal...normal threshold pedal change rate, dAPLarge...transient threshold pedal change rate, θ...steering angle, θth...threshold steering angle, θNormal...normal threshold steering angle, θLarge...transient threshold steering angle, dθ...speed of change of steering angle, dθth...threshold steering angle change rate, dθNormal...normal threshold steering angle change rate, dθLarge...transient threshold steering angle change rate.

Claims

[Claim 1] an obstacle sensor that acquires information about an obstacle present in the traveling direction of the vehicle; a driver state sensor for acquiring a driver state parameter indicative of a state of a driver of the vehicle; a driver operator state sensor for acquiring an operator state parameter representing a state of a driver operator of the vehicle operated by the driver; determining whether or not a collision prediction condition is satisfied when it is predicted that the vehicle will collide with the obstacle based on information from the obstacle sensor; determining whether the driver is in an abnormal state in which the driver is unable to drive the vehicle based on the driver state parameters; When it is determined that the collision prediction condition is satisfied, When it is determined that the driver is in the abnormal state, an automatic brake control is executed to apply a braking force to the vehicle by a braking device provided in the vehicle without requiring the driver to operate the brakes, regardless of whether the driver is operating the driving operation element. When it is determined that the driver is not in the abnormal state, if the operator state parameter satisfies an operation determination condition, an override control is executed to prioritize driving of the vehicle based on the operation of the driving operator without executing the automatic brake control. A control unit configured as above. Equipped with The control unit includes: When it is determined that the collision prediction condition is satisfied, it is determined that the driver is not in the abnormal state. adopting, as the operation determination condition, a first condition that is satisfied by the operator state parameter when the driving operator is being operated, unless the operation determination condition is within a transitional period starting from a point in time when it is determined that the driver is not in the abnormal state and ending from the point in time when a predetermined time has elapsed since the start point; and if the driving operation control device is within the transition period, adopting, as the operation determination condition, a second condition that is satisfied by the operation control device state parameter when the likelihood that the driving operation control device is being operated based on the driver's intention is higher than when the first condition is satisfied. It was configured as follows: Vehicle control device.

Images