JP2008020950A - Cruise assist control device and cruise assist control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cruise assist control device and cruise assist control method suppressing temporary interruption of cruise assist control halfway even when an obstacle is detected and then the same obstacle is not detected. <P>SOLUTION: The cruise assist control device 1-1 comprises a front millimeter wave sensor 3 and obstacle detection section 21 for detecting the position of the obstacle existing in the traveling direction of one's own vehicle, a travel support control section 26 for assisting the running of the own vehicle, a collision risk calculation section 22 for calculating the collision risk of the own vehicle with the detected obstacle, namely TTC (time to collision), and a cruise assist control determining section 23 for determining necessity of the travel support control based on the calculated TTC. The travel support control determining section 23 keeps a control-required state for a predetermined holding period T even if it is determined to require control based on the calculated TTC and then determined not to require control based on the calculated TTC. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a travel support control device and a travel support control method, and more particularly, travel that performs travel support control that supports travel of the host vehicle based on a collision risk between the detected obstacle and the host vehicle. The present invention relates to a support control device and a driving support control method.

  2. Description of the Related Art Conventionally, a travel support control device that supports the travel of the host vehicle according to the travel state of the host vehicle and the situation of the traveling direction of the host vehicle has been proposed. As a conventional driving support control device, for example, as shown in Patent Document 1, the possibility of a collision between an obstacle and the host vehicle is determined from the distance between the traveling direction of the host vehicle and the detected obstacle, Some alarms about possible obstacles.

  Such a driving support control device includes an obstacle detection device that detects an obstacle present in the traveling direction of the host vehicle. This obstacle detection device includes an object detection device that detects an object that exists in front of the host vehicle, and an obstacle determination device. This object detection device detects the position of an object in front of the host vehicle, that is, the relative position between the object and the host vehicle, for example, using a millimeter wave radar. The obstacle determination device determines an object present in the traveling direction of the host vehicle as an obstacle among the objects present in front of the host vehicle detected by the object detection device. Thereby, the obstacle detection device can detect an obstacle present in the traveling direction of the host vehicle.

JP-A-10-29464

  By the way, in the above-described conventional obstacle detection device, it is difficult to continuously detect the obstacle present in the traveling direction of the own vehicle once detected every control cycle of the driving support control device. In other words, in the above-described conventional driving support control device, there is a possibility that the obstacle once detected is not detected in a certain control cycle, that is, the obstacle may be lost depending on the control cycle.

  Moreover, in the said conventional driving assistance control apparatus, when the own vehicle is drive | working the curve road, the advancing direction of the own vehicle turns into a direction along the curve road. The traveling direction of the host vehicle when the host vehicle is traveling on a curved road is based on the estimated R calculated from the rotation speed of the host vehicle detected by the yaw rate sensor. Therefore, the obstacle determination device determines, as an obstacle, an object that exists in the traveling direction of the host vehicle based on the estimated R among the objects detected by the object detection device.

  Here, the driver may perform slight steering steering to correct the traveling direction of the host vehicle when the host vehicle is traveling on a straight path. Since the rotation speed of the host vehicle also changes due to this slight steering by the driver, the estimated R changes due to this slight steering. That is, even when the host vehicle is traveling on a straight road, there is a possibility that an object that has been detected as an obstacle may not be detected as an obstacle due to a change in the rotation speed of the host vehicle.

  Thus, after determining that there is a possibility of a collision, the conventional driving support control device determines that there is actually a possibility of a collision between an obstacle and the host vehicle, but there is no possibility of a collision. There is a risk of determining that there is a possibility of a collision again. Therefore, in the conventional driving support control device, there is a possibility that the alarm is interrupted and the alarm for the same obstacle is repeated again. That is, in the conventional driving support control device, there is a possibility that the driving support control for the same obstacle is temporarily interrupted.

  The present invention has been made in view of the above, and after detecting an obstacle, even if the same obstacle cannot be detected, the driving support control that can suppress the driving support control from being interrupted once in the middle An object is to provide a device and a driving support control method.

  In order to solve the above-described problems and achieve the object, according to the present invention, obstacle detection means for detecting the position of an obstacle existing in the traveling direction of the host vehicle, and driving support for supporting the driving of the host vehicle. Driving support control means for controlling, collision risk calculating means for calculating a collision risk between the detected obstacle and the host vehicle, and control of the driving support control based on the calculated collision risk A driving support control determining unit that determines whether control is unnecessary, and the driving support control determining unit determines that the control is necessary based on the calculated collision risk, and then calculates the calculation. Even if it is determined that the control is unnecessary based on the determined collision risk level, the control required state is maintained for a predetermined holding period.

  In the present invention, the travel support control device is characterized in that the travel support control is alarm control that warns a driver of the host vehicle.

  In the present invention, the travel support control is characterized in that the travel support control is an intervention braking control that applies an intervention braking force to the host vehicle.

  According to the present invention, in the driving support control device, the collision risk is an inter-vehicle time between the detected obstacle and the host vehicle.

  According to the present invention, in the driving support control method for performing driving support control for supporting driving of the host vehicle, a procedure for detecting the position of an obstacle existing in the traveling direction of the host vehicle, and the detected obstacle A procedure for calculating the risk of collision between the vehicle and the host vehicle, a procedure for determining whether or not the driving support control is required based on the calculated risk of collision, and a procedure based on the calculated risk of collision And determining that control is not necessary based on the calculated collision risk level, and holding the control required state for a predetermined holding period.

  According to these inventions, the driving support control means detects the obstacle by the obstacle detection means, for example, the collision risk calculated by the collision risk calculation means, for example, between the detected obstacle and the host vehicle. After determining that control is necessary based on the inter-vehicle time, even if it is determined that control is not required based on the collision risk calculated by the collision risk calculation means, the same obstacle is not detected by the obstacle detection means. Then, the control required state is held for a predetermined holding period. In other words, after the obstacle detecting means detects the obstacle, the driving support control means detects that the same obstacle is not detected by the obstacle detecting means even if the obstacle is not detected by the obstacle detecting means. From this time on, the vehicle continues to perform driving support control, for example, alarm control and intervention braking control for a predetermined holding period. Therefore, even if the same obstacle cannot be detected after the obstacle is detected, it is possible to prevent the driving support control from being interrupted once. Thereby, a driver's discomfort can be suppressed.

  In the driving support control apparatus according to the present invention, the predetermined holding period varies depending on the type of the driving support control.

  In the present invention, the driving support control device further includes a holding period calculating unit that calculates the predetermined holding period, and the holding period calculating unit sets the predetermined holding period according to the calculated collision risk. It is characterized by calculating.

  In the driving support control apparatus according to the present invention, the holding period calculation means calculates the predetermined holding period shorter as the calculated collision risk is higher.

  According to these inventions, the predetermined holding period varies depending on the calculated collision risk and the type of driving support control. For example, the predetermined holding period is calculated to be shorter as the collision risk calculated by the holding period calculating unit is higher. In addition, the driving support control that is started when the calculated collision risk is high makes the predetermined holding period longer than the driving support control that is started when the calculated collision risk is low. In other words, by changing the predetermined holding period according to the calculated collision risk and the type of the driving support control, the obstacle detected by the obstacle detection unit is no longer an obstacle, for example, the detected obstacle is When the vehicle no longer exists in the traveling direction of the host vehicle, the period until the travel support control that has been held is stopped can be shortened according to the calculated collision risk and the type of travel support control. Therefore, the stop timing of the driving support control can be brought close to the timing at which the obstacle detected by the obstacle detection means is no longer an obstacle.

  Also, in the present invention, in the driving support control device, the driving support control means reduces a braking force applied to the host vehicle within the predetermined holding period, compared to the intervention braking force.

  According to the present invention, in the driving support control device, the driving support control means reduces the braking force within the period from the intervention braking force as the predetermined holding period elapses.

  According to these inventions, when the driving support control is the intervention braking control, the driving support control means applies the braking force applied to the host vehicle within the predetermined holding period to a braking force smaller than the intervention braking force instead of the intervention braking force. It is made smaller than the intervention braking force as the power or the predetermined holding period elapses. Therefore, the driving support control means can bring the traveling state of the host vehicle closer to the state where the intervention braking control is not performed within the predetermined holding period. Thus, even if the intervention braking control is stopped after the predetermined holding period, the running state of the host vehicle can be brought close to the state in which the intervention braking control is not performed in advance within the predetermined holding period. Compared to the case where this intervention braking force suddenly stops being applied to the own vehicle from the state where the vehicle is applied to the own vehicle, the operation state of the own vehicle can be quickly returned to the state where the intervention braking control is no longer performed. As a result, the driver's uncomfortable feeling can be suppressed.

  The driving support control device and the driving support control method according to the present invention continue to perform the driving support control for a predetermined holding period after the same obstacle is no longer detected by the obstacle detecting means. Even if an obstacle cannot be detected, it is possible to prevent the driving support control from being temporarily interrupted.

  Hereinafter, the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by the following Example. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same. Further, in the following embodiment, a case will be described in which the driving support control device performs contact reduction between the host vehicle and an obstacle, impact reduction at the time of collision, that is, pre-crash safety (PCS) control as driving support control. This driving support control device can perform automatic driving control, that is, adaptive cruise control (ACC) control, which automatically controls driving of the host vehicle according to the road shape in the traveling direction of the host vehicle and the presence or absence of a preceding vehicle. May be. Further, in the following embodiment, a case will be described in which the driving support control device performs alarm braking control and intervention braking control as driving support control, which is one of alarm controls for alarming the driver of the host vehicle. Alarm control and driving support control are not limited to this. For example, the alarm control may be ON / OFF control of an alarm lamp, alarm sound generation control, seat belt winding control, and the like. In addition, the driving support control includes assist braking control that gives the vehicle an assist braking force that assists the braking force applied to the host vehicle by the driver, airbag operation control, seat belt hoisting control, and suspension shock absorber damping. It may be a quantity control.

  FIG. 1 is a diagram illustrating a configuration example of a driving support control device according to the invention. As shown in the figure, a driving support control device 1-1 according to the first embodiment is mounted on a host vehicle (not shown), and includes a control device 2, a forward millimeter wave radar 3, a brake device 4, The yaw rate sensor 5, the G sensor 6, the vehicle speed sensor 7, and the brake sensor 8 are configured.

  The control device 2 controls the entire vehicle travel support device. The control device 2 includes at least an obstacle detection unit 21, a collision risk calculation unit 22, a driving support control determination unit 23, a holding counter 24, a control counter 25, a driving support control unit 26, and a holding counter setting. Part 27.

  The obstacle detection unit 21 constitutes a part of the obstacle detection means. Among the objects detected by the forward millimeter wave radar 3, the obstacle detection unit 21 exists in the traveling direction of the own vehicle, that is, the own vehicle is traveling. An object existing on the same lane as the lane (a preceding vehicle traveling on the same lane or a falling object on the same lane) is detected as an obstacle.

  The collision risk calculation unit 22 is a collision risk calculation unit, and calculates the collision risk between the obstacle detected by the obstacle detection unit 21 and the host vehicle. In the first embodiment, the collision risk calculation unit 22 uses, as the collision risk, an inter-vehicle time between the obstacle detected by the obstacle detection unit 21 and the host vehicle (hereinafter simply referred to as “TTC”). Use. Here, the degree of collision risk increases as the TTC (Time to collision) becomes shorter, and decreases as the TTC becomes longer. The collision risk calculation unit 22 calculates TTC as infinite when the obstacle detection unit 21 does not detect an obstacle. That is, when the obstacle detection unit 21 does not detect the position data of the obstacle, the collision risk is the lowest. The case where the detected obstacle collides with the host vehicle is a case where TTC is zero.

  The driving support control determination unit 23 is a driving support control determination unit, and determines whether the driving support control by the driving support control unit 26 is necessary or unnecessary based on the collision risk calculated by the collision risk calculation unit 22. To do. That is, the driving support control determination unit 23 determines whether the driving support control is required or not required based on the calculated TTC. The driving support control determination unit 23 includes a request determination unit 23a and a control determination unit 23b.

  The request determination unit 23a is a part of the driving support control determination unit, and determines whether or not there is a request for driving support control by the driving support control unit 26 based on the collision risk calculated by the collision risk calculation unit 22. Is. That is, the request determination unit 23a determines whether or not there is a request for driving support control based on the calculated TTC. When the calculated TTC is equal to or less than a predetermined value (alarm braking control: TTC1, intervention braking control: TTC2), the request determination unit 23a determines that there is a request for driving support control, and the calculated TTC has a predetermined value. If exceeded, it is determined that there is no request for driving support control. The request determination unit 23a turns the request flag ON when determining that there is a request for driving support control, and turns the request flag OFF when determining that there is no request for driving support control.

  The control determination unit 23b is a part of the driving support control determination unit, and determines whether the driving support control by the driving support control unit 26 is necessary or not required based on the request determination unit 23a. To do. The control determining unit 23b basically determines that the driving support control is required when the request determining unit 23a determines that there is a request for driving support control, and the request determining unit 23a determines that there is no request for driving support control. Alternatively, when the control counter described later becomes equal to or greater than the predetermined control counter number (alarm braking control: Nc1, intervention braking control: Nc2), it is determined that the driving support control is unnecessary. The control determining unit 23b turns the control flag ON when determining that the driving support control is necessary, and turns the control flag OFF when determining that the driving support control is unnecessary.

  The holding counter 24 measures a period after the driving support control determination unit 23 determines that the driving support control is unnecessary. That is, the holding counter 24 measures a period after the control determination unit 23b determines that the driving support control is unnecessary. In this holding counter 24, a holding counter number Nm based on a predetermined holding period T is set by a holding counter setting unit 27 to be described later, and the set holding counter number Nm is subtracted.

  The control counter 25 measures a period after the travel support control unit 26 performs the travel support control.

  The travel support control unit 26 is a travel support control unit, and performs travel support control that supports the travel of the host vehicle. The driving support control unit 26 performs alarm braking control that applies an alarm braking force to the host vehicle and alarm braking control that applies an intervention braking force to the host vehicle, which is an alarm control that warns the driver of the host vehicle. . The driving support control unit 26 outputs to the brake device 4 a brake control signal that can cause the brake device 4 to generate an alarm braking force F1 and an intervention braking force F2. The intervention braking force F2 is a braking force that can decelerate the host vehicle most, for example, a maximum braking force. The warning braking force F1 is a braking force that allows the driver of the host vehicle to recognize that the host vehicle has decelerated, and is a smaller braking force than the intervention braking force.

  The holding counter setting unit 27 sets the holding counter number Nm of the holding counter 24. In this embodiment, the holding counter setting unit 27 sets the predetermined counter number Nm2 to the driving support control unit when the driving support control unit 26 performs alarm braking control on the predetermined counter number Nm1 stored in a storage unit (not shown) in advance. When the intervention braking control is performed by the control No. 26, the holding counter 24 is set as the holding counter number Nm. Here, the predetermined counter number Nm1 is calculated based on a predetermined holding period T1 in which the warning braking control is maintained when the driving support control unit 26 performs the alarm braking control. Further, the predetermined counter number Nm2 is calculated based on a predetermined holding period T2 for maintaining the intervention braking control when the driving support control unit 26 performs the intervention braking control. The predetermined counter number Nm2 is set shorter than the predetermined counter number Nm1. That is, the predetermined holding period T2 in the intervention braking control is set shorter than the predetermined holding period T1 in the alarm braking control, and the predetermined holding period T differs depending on the type of the driving support control.

  Various data are input to the control device 2. For example, the position data of the object detected by the front millimeter wave radar 3, the rotation speed of the host vehicle detected by the yaw rate sensor 5, the acceleration of the host vehicle detected by the G sensor 6, the vehicle speed of the host vehicle detected by the vehicle speed sensor 7, the brake A braking intention or the like by a driver (not shown) driving the host vehicle detected by the sensor 8 is input. On the other hand, the control device 2 outputs a brake control signal for operating the brake 43 of the brake device 4 in the first embodiment, based on the various input data described above and a map stored in a storage unit (not shown). .

  Here, the control device 2 includes an input / output port (I / O) (not shown), a processing unit, and a storage unit. An input / output port (not shown) is connected to the various sensors and the various devices, and inputs data output from the various sensors to the control device 2, and outputs control signals from the control device 2 to the various devices. It is. A processing unit (not shown) includes a RAM (Random Access Memory) and a CPU (Central Processing Unit). This processing unit is realized by loading a program based on the driving support control method of the driving support control device 1-1 according to the present invention into, for example, a RAM and executing the program. In addition, a storage unit (not shown) is configured by a ROM (Read Only Memory), a RAM, or a combination thereof. In the first embodiment, the driving support control method of the driving support control device 1-1 according to the present invention is realized by the control device 2. However, the present invention is not limited to this and is formed separately from the control device 2. It may be realized by a control device.

  The forward millimeter wave radar 3 is a part of the obstacle detection means and is an object detection means. The front millimeter wave radar 3 is attached to, for example, the center of the front portion of the host vehicle. The forward millimeter wave radar 3 detects an object existing in front of the host vehicle. The object detected by the front millimeter wave radar 3, that is, the position data of the object is output to the control device 2. The forward millimeter wave radar 3 is a narrow-angle wide-angle switching type millimeter-wave radar in which a short-distance downgraded monopulse system is added to a long-distance narrow-angle DBF system, for example. Here, the forward millimeter wave radar 3 is a radar that detects the position of an object using millimeter waves. The front millimeter wave radar 3 emits a millimeter wave, and in this embodiment, emits a millimeter wave that is emitted from a front surface of the host vehicle in a predetermined range including the traveling direction and reflected by an object existing in front of the host vehicle. It is. Then, the front millimeter wave radar 3 calculates the distance from the front millimeter wave radar to the object, that is, the distance from the own vehicle to the object ahead by measuring the time from emission to reception. Further, the forward millimeter wave radar 3 can calculate the relative velocity with respect to the object by using the Doppler effect. Further, the front millimeter wave radar 3 detects the direction of the millimeter wave that is received with the strongest reflection among the received millimeter waves, and calculates the angle between the front of the host vehicle and the direction of the object from that direction. Accordingly, when the position of the object is detected by the forward millimeter wave radar 3, the distance to the object, the relative speed, and the angle are input to the control device 2 as the position data of the detected object. When the millimeter wave reflected by the object can be received by the front millimeter wave radar 3, the position of the object is detected. Therefore, each time the millimeter wave reflected by the object is received, the position of one object is detected. Will be obtained. In addition, the front millimeter wave radar 3 in this embodiment is configured to emit, receive, and calculate the distance to the object, the relative speed, and the angle, but is not limited thereto. For example, the forward millimeter wave radar 3 only emits and receives millimeter waves, and outputs a detection value based on the received millimeter waves to the control device 2. In the control device 2, the distance to the object, relative speed, angle May be calculated.

  The brake device 4 applies braking force to the host vehicle to decelerate the host vehicle or to maintain the stop state of the host vehicle. The brake device 4 includes a brake control device 41, a brake actuator 42, a brake 43, and a brake pedal 44 including a master cylinder (not shown). The brake control device 41 controls the operation of the braking system, for example, controls the operation of the brake actuator 42 connected to the brake control device 41. In addition, the brake control device 41 operates the brake actuator 42 based on the depression amount of the brake pedal 44 by the driver detected by the brake sensor 8 and the traveling state of the host vehicle. The brake control device 41 can also operate the brake actuator 42 by a brake control signal output from the control device 2. The brake actuator 42 controls the supply of oil to the brake 43 that is hydraulically operated. The brake 43 applies a braking force to the host vehicle based on the hydraulic pressure controlled by the brake actuator 42. The brake 43 is arranged to be paired with each wheel of the host vehicle (not shown). The brake 43 is a hydraulic brake that is operated by a hydraulic pressure such as a disc brake or a drum brake. The brake pedal 44 directly controls the operation of the brake actuator 42 via the master cylinder, and applies the braking force of the host vehicle based on the driver's intention to decelerate.

  When the driver depresses the brake pedal 44, the brake device 4 directly operates the brake actuator 42 via the master cylinder, applies hydraulic pressure to the brake 43, applies a braking force to the host vehicle by the driver, Decelerate the host vehicle. Further, when the driver depresses the brake pedal 44, the brake control device 41 operates the brake actuator 42 based on the depression amount of the brake pedal 44 by the driver, applies hydraulic pressure to the brake 43, and operates the brake device 4. A braking force greater than the braking force applied to the host vehicle by the driver is applied to assist the driver in decelerating the host vehicle. Furthermore, even if the driver does not depress the brake pedal 44, the brake control device 41 activates the brake actuator 42 according to the brake control signal from the control device 2, and applies hydraulic pressure to the brake 43. A braking force can be applied to the vehicle to decelerate the host vehicle.

  The yaw rate sensor 5 detects the rotation speed of the host vehicle. The rotation speed detected by the yaw rate sensor 5 is output to the control device 2. The rotation speed of the host vehicle is used, for example, when the obstacle detection unit 21 detects an object present in the traveling direction of the host vehicle as an obstacle among the objects detected by the forward millimeter wave radar 3.

  The G sensor 6 detects the acceleration of the host vehicle. The acceleration detected by the G sensor 6 is output to the control device 2. The acceleration of the host vehicle is used when the driving support control unit 26 performs the driving support control, for example.

  The vehicle speed sensor 7 detects the vehicle speed of the host vehicle. The vehicle speed detected by the vehicle speed sensor 7 is output to the control device 2. The vehicle speed of the host vehicle is used when TTC is calculated by the collision risk calculation unit 22, for example.

  The brake sensor 8 detects the amount of depression when the brake pedal 44 is depressed by the driver. The brake sensor 8 also detects whether or not the driver has a braking intention. The depression amount of the brake pedal 44 detected by the brake sensor 8 is output to the control device 2.

  Next, a driving support control method using the driving support control device 1-1 according to the first embodiment will be described. FIG. 2 is an operation flowchart of the alarm braking control of the driving support control apparatus according to the first embodiment. FIG. 3 is a diagram illustrating a relationship among a request flag, a holding counter, a control flag, a control counter, a braking force, and TTC. FIG. 4 is an operation flowchart of the intervention braking control of the driving support control apparatus according to the first embodiment. FIG. 5 is a diagram illustrating a relationship among a request flag, a holding counter, a control flag, a control counter, a braking force, and TTC.

  First, an alarm braking control method among the driving support control methods by the driving support control device 1-1 according to the first embodiment will be described. The driving support control by the driving support control device 1-1 is performed every control cycle of the driving support control device 1-1. As shown in FIG. 2, first, the obstacle detection unit 21 of the control device 2 detects an obstacle (step ST101). Here, when the front millimeter wave radar 3 detects an object in front of the own vehicle, the obstacle detection unit 21 detects the object detected by the yaw rate sensor 5 and output to the control device 2 among the objects. When there is an object that exists in the traveling direction of the host vehicle based on the estimated R calculated based on the rotation speed, an obstacle that exists in the traveling direction of the host vehicle is detected.

  Next, the collision risk calculation unit 22 of the control device 2 calculates TTC (step ST102). Here, the collision risk degree calculation unit 22 is based at least on the obstacle position data detected by the obstacle detection unit 21 and the vehicle speed of the host vehicle detected by the vehicle speed sensor 7 and output to the control device 2. To calculate TTC.

  Next, the request determination unit 23a of the driving support control determination unit 23 of the control device 2 determines whether or not the calculated TTC is equal to or less than a predetermined value TTC1 (step ST103). Here, the request determination unit 23a determines whether or not the calculated TTC has reached TTC1, which is a timing at which the braking support control unit 26 performs alarm braking control.

  Next, when it is determined that the calculated TTC is equal to or less than the predetermined value TTC1, the request determination unit 23a turns on the request flag (step ST104). Here, when the calculated TTC reaches the predetermined value TTC1, the request determination unit 23a switches the request flag from OFF to ON (see A1 in FIG. 3).

  Next, the control determination unit 23b of the driving support control determination unit 23 turns on the control flag when the request determination unit 23a turns on the request flag (step ST105). Here, when the request flag is turned ON, the control determination unit 23b switches the control flag from OFF to ON (see C1 in FIG. 3). That is, the driving support control determination unit 23 determines that the control of alarm braking control by the driving support control unit 26 is necessary.

  Next, when the control flag is turned ON, the holding counter setting unit 27 of the control device 2 sets the holding counter number Nm in the holding counter 24 (step ST106). Here, the holding counter setting unit 27 sets the predetermined counter number Nm1 when the alarm braking control is performed by the driving support control unit 26 stored in advance in a storage unit (not shown) as the holding counter number Nm in the holding counter 24 ( (See B1 in FIG. 3).

  Next, the control counter 25 of the control device 2 performs counting (step ST107). Here, when the control determination unit 23b determines that the control flag is ON, the control counter 25 starts counting (see D1 in FIG. 3).

  Next, the driving support control unit 26 of the control device 2 determines whether or not the control counter number Nc of the control counter 25 is equal to or greater than the predetermined control counter number Nc1 (step ST108). Here, the predetermined control counter number Nc1 is a control counter number Nc based on a predetermined control period from when the control flag is turned on until the driving support control unit 26 starts alarm braking control and stops. Therefore, the driving support control unit 26 determines whether the control flag is turned on and a predetermined control period for performing the alarm braking control has elapsed.

  Next, when it is determined that the control counter number Nc of the control counter 25 is less than the predetermined control counter number Nc1, the driving support control unit 26 starts alarm braking control (step ST109). Here, when it is determined that the control counter number Nc of the control counter 25 is less than the predetermined control counter number Nc1, the driving support control unit 26 generates a brake control signal that causes the brake device 4 to generate the alarm braking force F1. 4 is output. The brake control device 41 of the brake device 4 operates the brake actuator 42 in response to the brake control signal, and supplies hydraulic pressure at which the brake 43 can apply an alarm braking force to the host vehicle. Thereby, the warning braking force F1 is generated by the brake device 4, and the warning braking force F1 is applied to the host vehicle (see E1 in FIG. 3). If the control flag remains ON, the driving support control unit 26 continues to perform the alarm braking control until it is determined that the control counter number Nc of the control counter 25 is equal to or greater than the predetermined control counter number Nc1, that is, continue. That is, the driving support control unit 26 continues to apply the alarm braking force F1 to the host vehicle by the brake device 4 until it is determined that the control counter number Nc of the control counter 25 is equal to or greater than the predetermined control counter number Nc1.

  On the other hand, when it is determined that the control counter number Nc of the control counter 25 is equal to or greater than the predetermined control counter number Nc1, the driving support control unit 26 stops the alarm braking control (step ST110). Here, when it is determined that the predetermined control period for performing the alarm braking control has elapsed after the control counter 25 continues to count while the control flag remains ON, the driving support control unit 26 performs the alarm braking control. Is stopped (see D2 in FIG. 3). Accordingly, the generation of the alarm braking force F1 by the brake device 4 is stopped, and the alarm braking force F1 is not applied to the host vehicle (see E2 in FIG. 3). Note that when the alarm braking control is stopped in step ST110, the driving support control device 1-1 ends one control cycle, and then shifts to the control cycle. In addition, when the alarm braking control is stopped in step ST110, the control counter number Nc of the control counter 25 is not cleared when the next control cycle is started. Therefore, in step ST108, the control counter number Nc of the control counter 25 is It is determined again that the number of control counters is greater than or equal to Nc1. Therefore, when the same obstacle existing in the traveling direction of the host vehicle is continuously detected in step ST101, and it is determined in step ST103 that TTC calculated based on the same obstacle is TTC1 or less, the driving support control unit 26 again. Therefore, the alarm braking control is not performed. That is, when the same obstacle can be detected in each control cycle, the driving support control unit 26 does not perform the alarm braking control for the obstacle twice.

  Here, during the warning braking control by the driving support control unit 26 or after the warning braking control is stopped, the forward millimeter wave radar 3 cannot detect an object existing ahead of the host vehicle, or the traveling direction of the host vehicle is There is a case where an object that has been detected as an obstacle in the previous control cycle is not detected as an obstacle. In this case, the obstacle detection unit 21 does not detect an obstacle present in the traveling direction of the host vehicle in step ST101, and the collision risk calculation unit 22 calculates TTC as infinite in step ST102.

  Accordingly, it is determined that the TTC calculated in step ST103 exceeds the predetermined value TTC1, and the request determination unit 23a turns off the request flag (step ST111). Here, the request determination unit 23a switches the request flag from ON to OFF when no obstacle present in the traveling direction of the host vehicle is detected (see A2 in FIG. 3).

  Next, as shown in FIG. 2, the holding counter 24 determines whether or not the control flag is ON (step ST112). Here, during the alarm braking control by the driving support control unit 26 or after the alarm braking control is stopped, the control determination unit 23b switches the control flag from OFF to ON in step ST105, so the control flag is ON. It is judged. On the other hand, when the alarm braking control by the driving support control unit 26 is not started, it is determined that the control flag is OFF. Note that, when it is determined in step ST112 that the control flag is OFF, the driving support control device 1-1 ends one control cycle and then shifts to the control cycle.

  Next, when it is determined that the control flag is ON, the holding counter 24 subtracts the holding counter (step ST113). Here, the holding counter 24 starts subtraction of the holding counter number Nm (= Nm1) set by the holding counter setting unit 27 (see B2 in FIG. 3).

  Next, the holding counter 24 determines whether or not the subtracted holding counter number Nm exceeds 0 (step ST114). Here, the holding counter 24 determines whether or not the subtracted holding counter number Nm has become zero. That is, the holding counter 24 determines whether or not a predetermined holding period T1 when the driving support control unit 26 performs the alarm braking control has elapsed.

  Next, when it is determined that the subtracted holding counter number Nm exceeds 0, the control counter 25 performs counting (step ST107). Here, when it is determined that the holding counter number Nm subtracted by the holding counter 24 exceeds 0, the control counter 25 continues counting (see D3 in FIG. 3).

  Next, the driving support control unit 26 determines whether or not the control counter number Nc of the control counter 25 is equal to or greater than a predetermined control counter number Nc1 (step ST108). Here, when the alarm braking control by the driving support control unit 26 is being performed, it is determined that the control counter number Nc of the control counter 25 is less than the predetermined control counter number Nc1. In addition, when the alarm braking control by the driving support control unit 26 is stopped, it is determined that the control counter number Nc of the control counter 25 is equal to or greater than the predetermined control counter number Nc1.

  Next, when it is determined that the control counter number Nc of the control counter 25 is less than the predetermined control counter number Nc1, the driving support control unit 26 continues the alarm braking control (step ST109). Here, when the braking support control unit 26 is in the alarm braking control, even if the obstacle cannot be detected, the alarm braking control is continued if the subtracted holding counter number Nm exceeds 0. To do. That is, the driving support control unit 26 keeps the alarm braking control continued if the predetermined holding period T1 has not elapsed while the alarm braking control is being performed.

  In addition, when it is determined that the control counter number Nc of the control counter 25 is equal to or less than the predetermined control counter number Nc1, the driving support control unit 26 stops the alarm braking control (step ST110). Here, the driving support control unit 26 stops the alarm braking control if the number Nm of subtracted holding counters exceeds 0 even if the obstacle cannot be detected when the alarm braking control is stopped. Leave. That is, as shown in FIG. 3, when the warning braking control is stopped, the driving support control unit 26 stops the alarm braking control if the predetermined holding period T1 has not elapsed.

  Here, there is a case where an obstacle that has been detected once is detected again during the alarm braking control by the driving support control unit 26 or after the alarm braking control is stopped. In this case, in step ST101, the obstacle detection unit 21 detects again an obstacle existing in the traveling direction of the host vehicle, and in step ST103, it is determined that TTC calculated based on the same obstacle is TTC1 or less, and step ST104. In step ST106, the request flag is switched from OFF to ON again (see A3 in FIG. 3). In step ST106, the holding counter setting unit 27 subtracts the predetermined holding counter number Nm1 as the holding counter number Nm. (See B3 in FIG. 3).

  On the other hand, if the obstacle is not detected during the alarm braking control by the driving support control unit 26 or after the alarm braking control is stopped, and the obstacle no longer exists in the traveling direction of the own vehicle, the predetermined holding is performed. The period T1 elapses. In this case, the obstacle detection unit 21 does not detect an obstacle present in the traveling direction of the host vehicle in step ST101, and it is determined that the TTC calculated as infinity in step ST103 exceeds the predetermined value TTC1, and step ST111. In step ST114, the request flag is switched from ON to OFF (see A4 in FIG. 3), and it is determined that the holding counter number Nm subtracted in step ST114 exceeds 0 (see B4 in FIG. 3). When -1 repeats the control cycle, it is determined that the predetermined holding period T1 has elapsed and the subtracted holding counter number Nm is 0 (B5 in FIG. 3), and the control determining unit 23b sets the control flag to OFF. (Step ST115). Here, the control determination unit 23b switches the control flag from ON to OFF when the predetermined holding period T1 elapses (see C4 in FIG. 3). That is, the driving support control determination unit 23 determines that the alarm braking control by the driving support control unit 26 is unnecessary.

  Next, the driving support control unit 26 stops the alarm braking control (step ST116). Here, the driving assistance control unit 26 stops the alarm braking control when the control flag is switched from ON to OFF by the control determination unit 23b.

  Next, the control counter 25 clears the counter (step ST117). Here, when the control flag is switched from ON to OFF by the control determination unit 23b, the control counter 25 sets the control count number Nc to 0 (see D5 in FIG. 3). Note that when the control count number Nc of the control counter 25 is set to 0 in step ST117, the driving support control device 1-1 ends one control cycle and then shifts to the control cycle.

  In the conventional driving support control device, when no obstacle is detected during the alarm braking control or after the alarm braking control is stopped, the request determination unit 23a switches the request flag from ON to OFF in step ST111, and the control flag is set. It was switched from ON to OFF (C2 in FIG. 3). As a result, in the conventional driving support control device, the control counter 25 has cleared the counter (D3 in FIG. 3), so that it is no longer detected after the alarm braking control by the driving support control unit 26 is stopped, for example. If an obstacle is detected again, the request flag is switched from OFF to ON again in step ST104 (A3 in FIG. 3), and the control flag is switched from OFF to ON again in step ST105 (C3 in FIG. 3). The control counter 25 in which the control count number Nc is cleared in ST117 performs counting again in step ST107 (D4 in FIG. 3), and the alarm braking control is started again in step ST109 (E2 in FIG. 3).

  However, in the case where warning braking control is performed in the driving support control device 1-1 according to the first embodiment, the driving support control unit 26 detects the obstacle by the obstacle detection unit 21, and the collision risk calculation unit 22 Based on the calculated collision risk TTC (TTC is equal to or less than a predetermined value TTC1), after the control determination unit 23b of the driving support control determination unit 23 determines that control is necessary, the obstacle detection unit 21 detects the same obstacle. By not being detected, based on the TTC that is the collision risk calculated by the collision risk calculation unit 22 (TTC (infinity) exceeds a predetermined value TTC1), the control determination unit 23b of the travel support control determination unit 23 controls the TTC. Even if it is determined to be unnecessary, the state requiring control is held for a predetermined holding period T1. That is, after the obstacle detection unit 21 detects the obstacle, the driving support control unit 26 detects the same obstacle by the obstacle detection unit 21 even if the obstacle detection unit 21 does not detect the same obstacle. The alarm braking control, which is the alarm control, continues to be performed for a predetermined holding period T1 from the time when it is no longer performed. Therefore, even if the same obstacle cannot be detected after the obstacle is detected, it is possible to prevent the alarm braking control from being temporarily interrupted or being performed again. Thereby, a driver's discomfort can be suppressed.

  Next, an intervention braking control method among the driving support control methods by the driving support control device 1-1 according to the first embodiment will be described. The driving support control by the driving support control device 1-1 is performed every control cycle of the driving support control device 1-1. Further, the intervention braking control method by the driving support control device 1-1 according to the first embodiment has the same basic operation as the warning braking control method, and therefore will be described in a simplified manner.

  As shown in FIG. 4, first, the obstacle detection unit 21 of the control device 2 detects an obstacle (step ST201).

  Next, the collision risk calculation unit 22 of the control device 2 calculates TTC (step ST202).

  Next, the request determination unit 23a of the driving support control determination unit 23 of the control device 2 determines whether or not the calculated TTC is equal to or less than a predetermined value TTC2 (step ST203). Here, the request determination unit 23a determines whether or not the calculated TTC has reached TTC2, which is a timing at which intervention braking control is performed by the driving support control unit 26.

  Next, when it is determined that the calculated TTC is equal to or less than the predetermined value TTC2, the request determination unit 23a turns on the request flag (step ST204). Here, when the calculated TTC reaches the predetermined value TTC2, the request determination unit 23a switches the request flag from OFF to ON (see A5 in FIG. 5).

  Next, the control determination unit 23b of the driving support control determination unit 23 sets the control flag to ON when the request determination unit 23a sets the request flag to ON (step ST205). Here, when the request flag is turned ON, the control determination unit 23b switches the control flag from OFF to ON (see C5 in FIG. 5). That is, the driving support control determination unit 23 determines that the intervention braking control by the driving support control unit 26 is necessary.

  Next, when the control flag is turned ON, the holding counter setting unit 27 of the control device 2 sets the holding counter number Nm in the holding counter 24 (step ST206). Here, the holding counter setting unit 27 sets the predetermined counter number Nm2 when the intervention braking control is performed by the driving support control unit 26 stored in advance in a storage unit (not shown) as the holding counter number Nm in the holding counter 24 ( (See B6 in FIG. 5).

  Next, the control counter 25 of the control device 2 performs counting (step ST207). Here, the control counter 25 starts counting when the control determination unit 23b determines that the control flag is ON (see D6 in FIG. 5).

  Next, the driving support control unit 26 of the control device 2 determines whether or not the control counter number Nc of the control counter 25 is equal to or greater than a predetermined control counter number Nc2 (step ST208). Here, the predetermined control counter number Nc2 is a control counter number Nc based on a predetermined control period from when the control flag is turned on until the driving support control unit 26 starts and stops the intervention braking control.

  Next, when it is determined that the control counter number Nc of the control counter 25 is less than the predetermined control counter number Nc2, the driving support control unit 26 starts interventional braking control (step ST209). Here, when it is determined that the control counter number Nc of the control counter 25 is less than the predetermined control counter number Nc2, the driving support control unit 26 generates the intervention braking force F2 by the brake device 4 and controls the host vehicle to perform the intervention control. Power F2 is applied (see E4 in FIG. 5). If the control flag remains ON, the driving support control unit 26 continues to perform the intervention braking control until it is determined that the control counter number Nc of the control counter 25 is equal to or greater than the predetermined control counter number Nc2. continue.

  On the other hand, when it is determined that the control counter number Nc of the control counter 25 is equal to or greater than the predetermined control counter number Nc2, the driving support control unit 26 stops the intervention braking control (step ST210).

  Here, during the intervention braking control by the driving support control unit 26, an object that has been detected as an obstacle in the previous control cycle may not be detected as an obstacle. In this case, it is determined that the TTC calculated in step ST203 exceeds the predetermined value TTC2, and the request determination unit 23a turns off the request flag (step ST211). Here, the request determination unit 23a switches the request flag from ON to OFF when an obstacle existing in the traveling direction of the host vehicle is not detected (see A6 in FIG. 5).

  Next, the holding counter 24 determines whether or not the control flag is ON (step ST212). Here, during the intervention braking control by the driving support control unit 26, since the control determination unit 23b switches the control flag from OFF to ON in step ST205, it is determined that the control flag is ON.

  Next, when it is determined that the control flag is ON, the holding counter 24 subtracts the holding counter (step ST213). Here, the holding counter 24 starts subtraction of the holding counter number Nm (= Nm2) set by the holding counter setting unit 27 (see B7 in FIG. 5).

  Next, the holding counter 24 determines whether or not the subtracted holding counter number Nm exceeds 0 (step ST214). Here, the holding counter 24 determines whether or not a predetermined holding period T2 when the driving support control unit 26 performs the intervention braking control has elapsed.

  Next, when it is determined that the subtracted holding counter number Nm exceeds 0, the control counter 25 performs counting (step ST207). Here, when it is determined that the holding counter number Nm subtracted by the holding counter 24 exceeds 0, the control counter 25 continues counting (see D7 in FIG. 5).

  Next, the driving support control unit 26 determines whether or not the control counter number Nc of the control counter 25 is equal to or greater than a predetermined control counter number Nc2 (step ST208).

  Next, when it is determined that the control counter number Nc of the control counter 25 is less than the predetermined control counter number Nc2, the driving support control unit 26 continues the intervention braking control (step ST209). Here, when the intervention braking control is being performed, the driving support control unit 26 continues the intervention braking control if the predetermined holding period T2 has not elapsed.

  If it is determined that the control counter number Nc of the control counter 25 is equal to or greater than the predetermined control counter number Nc2, the driving support control unit 26 stops the intervention braking control (step ST210).

  Here, during the intervention braking control by the driving support control unit 26, when an obstacle that is no longer detected is detected again, it is determined in step ST203 that the TTC calculated based on the same obstacle is TTC2 or less, In step ST204, the request flag is switched from OFF to ON again (see A7 in FIG. 5). In step ST206, the holding counter setting unit 27 is decremented by setting the predetermined holding counter number Nm2 as the holding counter number Nm. Set (see B8 in FIG. 5).

  On the other hand, if no obstacle is detected during the intervention braking control by the driving support control unit 26 and the obstacle no longer exists in the traveling direction of the host vehicle, the predetermined holding period T2 elapses. In ST211, the request flag is switched from ON to OFF (see A8 in FIG. 5), and it is determined that the holding counter number Nm subtracted in step ST214 exceeds 0 (see B9 in FIG. 5). When 1-1 repeats the control cycle, it is determined that the predetermined holding period T2 has elapsed and the subtracted holding counter number Nm is 0 (B10 in FIG. 5), and the control determining unit 23b turns off the control flag. (Step ST215). Here, the control determination unit 23b switches the control flag from ON to OFF when the predetermined holding period T2 elapses (see C8 in FIG. 5). That is, the driving support control determination unit 23 determines that the intervention braking control by the driving support control unit 26 is unnecessary.

  Next, the driving assistance control unit 26 stops the intervention braking control (step ST216).

  Next, the control counter 25 clears the counter (step ST217). Here, when the control flag is switched from ON to OFF by the control determination unit 23b, the control counter 25 sets the control count number Nc to 0 (see D9 in FIG. 5).

  In the conventional driving support control device, when no obstacle is detected during the intervention braking control, in step ST211, the request determination unit 23a switches the request flag from ON to OFF, and the control flag is switched from ON to OFF (FIG. 5 C6), the intervention braking control by the driving support control unit 26 was stopped (E5 in FIG. 5). As a result, in the conventional driving support control device, the control counter 25 has cleared the counter (D7 in FIG. 5). For example, during the intervention braking control by the driving support control unit 26, an obstacle that is no longer detected is detected. If it is detected again, the request flag is switched from OFF to ON again in step ST204 (A7 in FIG. 5), the control flag is switched from OFF to ON again in step ST205 (C7 in FIG. 5), and control is performed in step ST217. The control counter 25 having cleared the count number Nc performs counting again in step ST207 (D8 in FIG. 5), and intervention braking control is started again in step ST209 (E6 in FIG. 5).

  However, in the case where the intervention braking control is performed in the driving support control device 1-1 according to the first embodiment, the driving support control unit 26 detects the obstacle by the obstacle detecting unit 21, and the collision risk calculating unit 22 Based on the calculated collision risk TTC (TTC is equal to or less than a predetermined value TTC2), after the control determination unit 23b of the driving support control determination unit 23 determines that control is necessary, the obstacle detection unit 21 detects the same obstacle. By not being detected, based on the TTC that is the collision risk calculated by the collision risk calculation unit 22 (TTC (infinity) exceeds a predetermined value TTC2), the control determination unit 23b of the travel support control determination unit 23 controls the TTC. Even if it is determined that it is unnecessary, the control-required state is held for the predetermined holding period T2. That is, after the obstacle detection unit 21 detects the obstacle, the driving support control unit 26 detects the same obstacle by the obstacle detection unit 21 even if the obstacle detection unit 21 does not detect the same obstacle. Intervention braking control continues to be performed for a predetermined holding period T2 from when it is no longer performed. Therefore, even if the same obstacle cannot be detected after the obstacle is detected, it is possible to prevent the intervention braking control from being temporarily interrupted or being performed again. Thereby, a driver's discomfort can be suppressed.

  In the driving support control device 1-1 according to the first embodiment, the predetermined holding period T differs depending on the type of driving support control performed by the driving support control unit 26, that is, depending on the alarm braking control and the intervention braking control. Here, when the obstacle detected by the obstacle detection unit 21 is no longer an obstacle, for example, when the detected obstacle no longer exists in the traveling direction of the host vehicle, the held driving support control is stopped. The predetermined holding period T2 in the case where the intervention braking control is performed is shorter than the predetermined holding period T1 in the case where the alarm braking control is performed for the predetermined holding period T that is a period until the operation is performed. Accordingly, the timing at which the obstacle detected by the obstacle detector 21 is no longer an obstacle when the intervention braking control is performed rather than the warning braking control when the driving assistance control unit 26 stops the driving assistance control. Can be approached. As a result, when the intervention braking control is performed, the obstacle detection unit 21 does not detect the obstacle more than when the alarm braking control is performed, and the obstacle is actually detected in the traveling direction of the host vehicle. Can stop quickly when no longer exists.

  Next, the driving support control device 1-2 according to the second embodiment will be described. The difference between the driving support control device 1-2 according to the second embodiment and the driving support control device 1-1 according to the first embodiment is that the braking force within the period applied to the host vehicle during the predetermined holding period T2 in the intervention braking control. Is less than the intervention braking force. In the second embodiment, it is reduced as the predetermined holding period T2 elapses. As shown in FIG. 1, the driving support control device 1-2 according to the second embodiment has the same basic configuration as the driving support control device 1-1 according to the first embodiment, and thus the description thereof is omitted. . The driving support control device 1-2 according to the second embodiment is the same as the driving support control device 1-1 according to the first embodiment in the basic operation, and will be described in a simplified manner. Here, the alarm braking control method by the driving support control device 1-2 according to the second embodiment is the same as that of the driving support control device 1-1 of the first embodiment, the description thereof is omitted, and only the intervention braking control method is described. explain.

  FIG. 6 is an operation flowchart of the intervention braking control of the driving support control apparatus according to the second embodiment. FIG. 7 is a diagram illustrating a relationship among a request flag, a holding counter, a control flag, a control counter, a braking force, and TTC.

  As shown in FIG. 6, first, the obstacle detection unit 21 of the control device 2 detects an obstacle (step ST301). Next, the collision risk calculation unit 22 calculates TTC (step ST302). Next, the request determination unit 23a of the driving support control determination unit 23 determines whether or not the calculated TTC is equal to or less than a predetermined value TTC2 (step ST303). Next, when it is determined that the calculated TTC is equal to or less than the predetermined value TTC2, the request determination unit 23a turns on the request flag (step ST304). Here, when the calculated TTC reaches the predetermined value TTC2, the request determination unit 23a switches the request flag from OFF to ON (see A9 in FIG. 7).

  Next, the control determination unit 23b of the driving support control determination unit 23 sets the control flag to ON when the request determination unit 23a sets the request flag to ON (step ST305). Here, when the request flag is turned ON, the control determination unit 23b switches the control flag from OFF to ON (see C9 in FIG. 7). That is, the driving support control determination unit 23 determines that the intervention braking control by the driving support control unit 26 is necessary.

  Next, when the control flag is turned ON, the holding counter setting unit 27 sets the holding counter number Nm in the holding counter 24 (step ST306). Here, the holding counter setting unit 27 sets the predetermined counter number Nm2 when the intervention braking control is performed by the driving support control unit 26 stored in advance in a storage unit (not shown) as the holding counter number Nm in the holding counter 24 ( (See B11 in FIG. 7).

  Next, the control counter 25 performs counting (step ST307). Here, the control counter 25 starts counting when the control determination unit 23b determines that the control flag is ON (see D10 in FIG. 7).

  Next, the driving support control unit 26 of the control device 2 determines whether or not the control counter number Nc of the control counter 25 is equal to or greater than a predetermined control counter number Nc2 (step ST308). Next, when it is determined that the control counter number Nc of the control counter 25 is less than the predetermined control counter number Nc2, the driving support control unit 26 starts the intervention braking control (step ST309). Here, when it is determined that the control counter number Nc of the control counter 25 is less than the predetermined control counter number Nc2, the driving support control unit 26 generates the intervention braking force F2 by the brake device 4 and controls the host vehicle to perform the intervention control. Power F2 is applied (see E8 in FIG. 7).

  On the other hand, when it is determined that the control counter number Nc of the control counter 25 is equal to or greater than the predetermined control counter number Nc2, the driving support control unit 26 stops the intervention braking control (step ST310).

  Here, during the intervention braking control by the driving support control unit 26, if an object that has been detected as an obstacle in the previous control cycle is no longer detected as an obstacle, the TTC calculated in step ST303 exceeds a predetermined value TTC2. The request determination unit 23a turns off the request flag (step ST311). Here, the request determination part 23a switches a request flag from ON to OFF, if the obstruction which exists in the advancing direction of the own vehicle is not detected (refer A10 of FIG. 7).

  Next, the holding counter 24 determines whether or not the control flag is ON (step ST312). Next, since it is determined that the control flag is ON, the holding counter 24 subtracts the holding counter (step ST313). Here, the holding counter 24 starts subtraction of the holding counter number Nm (= Nm2) set by the holding counter setting unit 27 (see B12 in FIG. 7).

  Next, the holding counter 24 determines whether or not the subtracted holding counter number Nm exceeds 0 (step ST314). Here, the holding counter 24 determines whether or not a predetermined holding period T2 when the driving support control unit 26 performs the intervention braking control has elapsed.

  Next, when it is determined that the subtracted holding counter number Nm exceeds 0, the control counter 25 performs counting (step ST318). Here, when it is determined that the holding counter number Nm subtracted by the holding counter 24 exceeds 0, the control counter 25 continues counting (see D11 in FIG. 7).

  Next, the driving support control unit 26 determines whether or not the control counter number Nc of the control counter 25 is equal to or greater than a predetermined control counter number Nc2 (step ST319).

  Next, when it is determined that the control counter number Nc of the control counter 25 is less than the predetermined control counter number Nc2, the driving support control unit 26 continues the intervention braking control (step ST320). Here, when the intervention braking control is being performed, the driving support control unit 26 continues the intervention braking control if the predetermined holding period T2 has not elapsed.

  Here, the driving support control unit 26 continues the intervention braking control as described above, but the in-period braking force generated by the brake device 4 within the predetermined holding period T2 is not the normal intervention braking force F2. The intervention braking force F2 is decreased. Therefore, the braking force applied to the host vehicle is smaller than the intervention braking force F2. In addition, when it is determined that the holding counter number Nm subtracted in step ST314 exceeds 0 for each control cycle, the driving support control device 1-2 further reduces the braking force within this period from the intervention braking force F2. (Refer to the range of E9 to E10 in FIG. 7). That is, the braking force applied to the host vehicle is made smaller than the intervention braking force as the predetermined holding period T2 elapses. As a result, the driving support control unit 26 can bring the traveling state of the host vehicle closer to the state where the intervention braking control is not performed within the predetermined holding period T2.

  If it is determined that the control counter number Nc of the control counter 25 is equal to or greater than the predetermined control counter number Nc2, the driving support control unit 26 stops the intervention braking control (step ST310).

  Here, during the intervention braking control by the driving support control unit 26, when an obstacle that is no longer detected is detected again, it is determined in step ST303 that the TTC calculated based on the same obstacle is TTC2 or less, In step ST304, the request flag is switched from OFF to ON again (see A11 in FIG. 7). In step ST306, the holding counter setting unit 27 is subtracted from the holding counter 24, and the predetermined holding counter number Nm2 is set again as the holding counter number Nm. Set (see B13 in FIG. 7).

  On the other hand, if no obstacle is detected during the intervention braking control by the driving support control unit 26 and the obstacle no longer exists in the traveling direction of the host vehicle, the predetermined holding period T2 elapses. In ST311, the request flag is switched from ON to OFF (see A12 in FIG. 7), and it is determined that the holding counter number Nm subtracted in step ST314 exceeds 0 (see B14 in FIG. 7). When 1-2 repeats the control cycle, it is determined that the predetermined holding period T2 has elapsed and the subtracted holding counter number Nm is 0 (B15 in FIG. 7), and the control determining unit 23b turns off the control flag. (Step ST315). Here, the control determination unit 23b switches the control flag from ON to OFF when the predetermined holding period T2 elapses (see C10 in FIG. 7). That is, the driving support control determination unit 23 determines that the intervention braking control by the driving support control unit 26 is unnecessary.

  Next, the driving assistance control unit 26 stops the intervention braking control (step ST316). Next, the control counter 25 clears the counter (step ST317). Here, when the control flag is switched from ON to OFF by the control determination unit 23b, the control counter 25 sets the control count number Nc to 0 (see D12 in FIG. 7).

  As described above, in the case where the intervention braking control is performed in the driving support control device 1-2 according to the second embodiment, after the obstacle is detected, similarly to the driving support control device 1-1 according to the first embodiment. Even if the same obstacle cannot be detected, it is possible to prevent the intervention braking control from being interrupted once or being performed again. Thereby, a driver's discomfort can be suppressed. The predetermined holding period T differs depending on the type of the driving support control performed by the driving support control unit 26, that is, between the alarm braking control and the intervention braking control. When the intervention braking control is performed, the alarm braking control is performed. When the obstacle is not detected by the obstacle detection unit 21 and no obstacle exists in the traveling direction of the host vehicle, the vehicle can be stopped earlier than when the obstacle is being performed.

  Further, in the case where intervention braking control is performed in the traveling support control device 1-2 according to the second embodiment, the traveling support control unit 26 performs the intervention braking control on the traveling state of the host vehicle within the predetermined holding period T2. Since the approaching state is approached, even if the intervention braking control is stopped after the predetermined holding period T2 has elapsed (see B16 in FIG. 7), the running state of the host vehicle is controlled in advance within the predetermined holding period T2. It can be brought close to the state where it is no longer broken (see E10 in FIG. 7). Accordingly, after a predetermined holding period T2 has elapsed since the intervention braking force F2 is applied to the host vehicle, the intervention braking force F2 is suddenly not applied to the host vehicle (see E11 in FIG. 7). The traveling state of the host vehicle can be returned to a state where the intervention braking control is no longer performed (X1 in FIG. 7). Thereby, a driver's discomfort can be suppressed.

  Next, a driving support control apparatus 1-3 according to the third embodiment will be described. The difference between the driving support control device 1-3 according to the third embodiment and the driving support control device 1-1 according to the first embodiment is calculated in the third embodiment according to the calculated collision risk. The higher the collision risk is, that is, the shorter the TTC is, the shorter the predetermined holding period T is. As shown in FIG. 1, the driving support control device 1-3 according to the third embodiment has the same basic configuration as the driving support control device 1-1 according to the first embodiment, and thus the description thereof is omitted. . Here, the holding counter setting unit 27 calculates the predetermined holding period T according to the calculated collision risk. In the third embodiment, the holding counter setting unit 27 calculates a predetermined holding period T according to the calculated TTC, and sets the holding counter number Nm in the holding counter 24 based on the calculated predetermined holding period T. It is. The driving support control device 1-3 according to the third embodiment is similar to the driving support control device 1-1 according to the first embodiment in the basic operation, and therefore will be described in a simplified manner. Here, the warning braking control method by the driving support control device 1-3 according to the third embodiment is the same as that of the driving support control device 1-1 of the first embodiment, the description thereof is omitted, and only the intervention braking control method is described. explain.

  FIG. 8 is an operation flowchart of the intervention braking control of the driving support control apparatus according to the third embodiment. FIG. 9 is a diagram showing the relationship between TTC and the predetermined holding period T. As shown in FIG. FIG. 10 is a diagram showing the relationship between the predetermined holding period T and the holding counter number Nm. FIG. 11 is a diagram illustrating a relationship among a request flag, a holding counter, a control flag, a control counter, a braking force, and TTC.

  As shown in FIG. 8, first, the obstacle detection unit 21 of the control device 2 detects an obstacle (step ST401). Next, the collision risk calculation unit 22 calculates TTC (step ST402). Next, the request determination unit 23a of the driving support control determination unit 23 determines whether or not the calculated TTC is equal to or less than a predetermined value TTC2 (step ST403). Next, when it is determined that the calculated TTC is equal to or less than the predetermined value TTC2, the request determination unit 23a turns on the request flag (step ST404). Here, when the calculated TTC reaches the predetermined value TTC2, the request determination unit 23a switches the request flag from OFF to ON (see A13 in FIG. 11).

  Next, when the request determination unit 23a turns on the request flag, the control determination unit 23b of the driving support control determination unit 23 turns on the control flag (step ST405). Here, when the request flag is turned ON, the control determination unit 23b switches the control flag from OFF to ON (see C11 in FIG. 11). That is, the driving support control determination unit 23 determines that the intervention braking control by the driving support control unit 26 is necessary.

  Next, when the control flag is turned ON, the holding counter setting unit 27 calculates a predetermined holding period T based on the calculated TTC (step ST417). Here, the holding counter setting unit 27 calculates a predetermined holding period T based on the collision risk, that is, TTC, in order to set the holding counter number Nm in the holding counter 24. As shown in FIG. 9, the predetermined holding period T calculated based on this TTC is set to be shorter as the collision risk becomes higher, that is, as the TTC becomes shorter. That is, the holding counter setting unit 27 calculates the predetermined holding period T as the TTC approaches 0.

  Next, the holding counter setting unit 27 sets the holding counter number Nm in the holding counter 24 based on the calculated predetermined holding period T (step ST418). Here, the holding counter setting unit 27 calculates the holding counter number Nm based on the collision risk, that is, the predetermined holding period T calculated based on the TTC, and the holding counter 24 stores the calculated holding counter number Nm. Set. As shown in FIG. 10, the holding counter number Nm calculated based on the predetermined holding period T is set to increase as the predetermined holding period T becomes longer. Accordingly, the holding counter setting unit 27 first sets the holding counter number Nm3 calculated based on the predetermined holding period T3 calculated based on TTC2 in step ST417 as the holding counter number Nm in the holding counter 24 (FIG. 11 B16).

  Next, the control counter 25 performs counting (step ST406). Here, the control counter 25 starts counting when the control determination unit 23b determines that the control flag is ON (see D14 in FIG. 11).

  Next, the driving support control unit 26 determines whether or not the control counter number Nc of the control counter 25 is equal to or greater than a predetermined control counter number Nc2 (step ST407). Next, when it is determined that the control counter number Nc of the control counter 25 is less than the predetermined control counter number Nc2, the driving support control unit 26 starts intervention braking control (step ST408). Here, when it is determined that the control counter number Nc of the control counter 25 is less than the predetermined control counter number Nc2, the driving support control unit 26 generates the intervention braking force F2 by the brake device 4 and controls the host vehicle to perform the intervention control. Power F2 is applied (see E13 in FIG. 11).

  Here, if the control flag remains in the ON state, the driving support control unit 26 determines that the control counter number Nc of the control counter 25 is equal to or greater than the predetermined control counter number Nc2 until the driving support control device 1-2. Continues to perform the intervention braking control every control cycle, that is, continues (step ST408). Therefore, during the intervention braking control by the driving support control unit 26, the TTC is calculated for each control cycle in step ST402, and the predetermined holding period T is calculated based on the TTC calculated for each control cycle in step ST417. In ST418, the holding counter number Nm is set in the holding counter 24 based on the predetermined holding period T calculated for each control cycle.

  On the other hand, when it is determined that the control counter number Nc of the control counter 25 is equal to or greater than the predetermined control counter number Nc2, the driving support control unit 26 stops the intervention braking control (step ST409).

  Here, during the intervention braking control by the driving support control unit 26, if an object that has been detected as an obstacle in the previous control cycle is not detected as an obstacle a plurality of times, each time the obstacle is no longer detected, a step is performed. It is determined that the TTC calculated in ST403 exceeds the predetermined value TTC2, and the request determination unit 23a turns off the request flag (step ST410). Here, if an obstacle that exists in the traveling direction of the host vehicle is not detected, the request determination unit 23a switches the request flag from ON to OFF every time the obstacle is not detected (see A14 and A16 in FIG. 11). ).

  Next, the holding counter 24 determines whether or not the control flag is ON (step ST411).

  Next, since it is determined that the control flag is ON, the holding counter 24 subtracts the holding counter (step ST412). Here, the holding counter number 24 set in the holding counter 24 is, as described above, the holding counter numbers Nm4 and Nm5 calculated based on the predetermined holding periods T4 and T5 calculated in the previous control cycle. It has become. Accordingly, the holding counter 24 starts subtraction of the holding counter number Nm (= Nm4, Nm5) set by the holding counter setting unit 27 every time no obstacle is detected (see B17 and B19 in FIG. 11).

  Next, the holding counter 24 determines whether or not the subtracted holding counter number Nm exceeds 0 (step ST413). Here, the holding counter 24 determines whether or not the predetermined holding periods T4 and T5 when the driving support control unit 26 performs the intervention braking control have elapsed.

  Next, when it is determined that the subtracted holding counter number Nm exceeds 0, the control counter 25 performs counting (step ST406). Here, if it is determined that the holding counter number Nm subtracted by the holding counter 24 exceeds 0, the control counter 25 continues counting (see D15 and D16 in FIG. 11).

  Next, the driving support control unit 26 determines whether or not the control counter number Nc of the control counter 25 is equal to or greater than a predetermined control counter number Nc2 (step ST407).

  Next, when it is determined that the control counter number Nc of the control counter 25 is less than the predetermined control counter number Nc2, the driving support control unit 26 continues the intervention braking control (step ST408). Here, when the intervention support control is being performed, the driving support control unit 26 determines that the predetermined holding periods T4 and T5 have not elapsed each time an obstacle is no longer detected (see B21 and B22 in FIG. 11). Keep braking control continued.

  If it is determined that the control counter number Nc of the control counter 25 is equal to or less than the predetermined control counter number Nc2, the driving support control unit 26 stops the intervention braking control (step ST409).

  Here, during the intervention braking control by the driving support control unit 26, when an obstacle that is no longer detected is detected again, it is determined in step ST403 that the TTC calculated based on the same obstacle is TTC2 or less, In step ST404, the request flag is switched from OFF to ON again (see A15 and A17 in FIG. 11). In step ST417, a predetermined holding period T is calculated based on the calculated TTC, and in step ST418, the predetermined predetermined period is calculated. Based on the holding period T, the holding counter number Nm is set again in the holding counter 24 (see B18 and B20 in FIG. 11).

  On the other hand, if no obstacle is detected during the intervention braking control by the driving support control unit 26 and the obstacle no longer exists in the traveling direction of the host vehicle, the predetermined holding period T5 elapses. In ST410, the request flag is switched from ON to OFF (see A17 in FIG. 11), and it is determined that the holding counter number Nm subtracted in step ST413 exceeds 0 (see B20 in FIG. 11). When 1-3 repeats the control cycle, it is determined that the predetermined holding period T5 has elapsed and the subtracted holding counter number Nm is 0 (B22 in FIG. 11), and the control determining unit 23b turns off the control flag. (Step ST414). Here, the control determination unit 23b switches the control flag from ON to OFF when the predetermined holding period T5 elapses (see C12 in FIG. 11). That is, the driving support control determination unit 23 determines that the intervention braking control by the driving support control unit 26 is unnecessary.

  Next, the driving support control unit 26 stops the intervention braking control (see E18 in FIG. 11) (step ST415). Next, the control counter 25 clears the counter (step ST416). Here, when the control flag is switched from ON to OFF by the control determination unit 23b, the control counter 25 sets the control count number Nc to 0 (see D17 in FIG. 11).

  As described above, in the case where the intervention braking control is performed in the travel support control apparatus 1-3 according to the third embodiment, after the obstacle is detected, similarly to the travel support control apparatus 1-1 according to the first embodiment. Even if the same obstacle cannot be detected, it is possible to prevent the intervention braking control from being interrupted once or being performed again. Thereby, a driver's discomfort can be suppressed. The predetermined holding period T differs depending on the type of the driving support control performed by the driving support control unit 26, that is, between the alarm braking control and the intervention braking control. When the intervention braking control is performed, the alarm braking control is performed. When the obstacle is not detected by the obstacle detection unit 21 and no obstacle exists in the traveling direction of the host vehicle, the vehicle can be stopped earlier than when the obstacle is being performed.

  Further, in the case where the intervention braking control is performed in the driving support control device 1-3 according to the third embodiment, the predetermined holding period T is calculated according to the calculated collision risk. Here, when the obstacle detected by the obstacle detection unit 21 is no longer an obstacle, for example, when the detected obstacle no longer exists in the traveling direction of the host vehicle, the held intervention support control is stopped. The predetermined holding period T that is a period until the time of the collision is shortened as the calculated collision risk is higher, that is, as the TTC is shorter. Therefore, the timing at which the obstacle detected by the obstacle detection unit 21 is no longer an obstacle as the TTC is shortened (steps E15 and E17 in FIG. 11) of the intervention braking control by the driving support control unit 26 (FIG. 11). E14, E16). As a result, when the intervention braking control is being performed, the obstacle detection unit 21 does not detect an obstacle, and in the case where no obstacle is actually present in the traveling direction of the host vehicle, the collision risk is reduced. The higher the value, the faster the stop (in FIG. 11, X2> X3).

  Next, a driving support control device 1-4 according to a fourth embodiment will be described. The difference between the driving support control device 1-4 according to the fourth embodiment and the driving support control device 1-3 according to the third embodiment is that the braking force within the period applied to the host vehicle within the predetermined holding period T2 in the intervention braking control. Is less than the intervention braking force. In the second embodiment, it is reduced as the predetermined holding period T2 elapses. As illustrated in FIG. 1, the driving support control device 1-4 according to the fourth embodiment has the same basic configuration as the driving support control device 1-3 according to the third embodiment, and thus the description thereof is omitted. . Here, similarly to the second embodiment, the holding counter setting unit 27 calculates the predetermined holding period T according to the calculated collision risk, that is, according to the calculated TTC, and calculates the calculated predetermined holding period. Based on T, the holding counter number Nm is set in the holding counter 24. The driving support control device 1-4 according to the fourth embodiment is the same as the driving support control device 1-3 according to the third embodiment in the basic operation, and therefore will be described in a simplified manner. Here, the alarm braking control method by the driving support control device 1-4 according to the fourth embodiment is the same as that of the driving support control device 1-1 of the first embodiment, the description thereof is omitted, and only the intervention braking control method is described. explain.

  FIG. 12 is an operation flowchart of the intervention braking control of the driving support control apparatus according to the fourth embodiment. FIG. 13 is a diagram illustrating a relationship among a request flag, a holding counter, a control flag, a control counter, a braking force, and TTC.

  As shown in FIG. 12, first, the obstacle detection unit 21 of the control device 2 detects an obstacle (step ST501). Next, the collision risk calculation unit 22 calculates TTC (step ST502). Next, the request determination unit 23a of the driving support control determination unit 23 determines whether or not the calculated TTC is equal to or less than a predetermined value 2 (step ST503). Next, when it is determined that the calculated TTC is equal to or less than the predetermined value TTC2, the request determination unit 23a turns on the request flag (step ST504). Here, when the calculated TTC reaches the predetermined value TTC2, the request determination unit 23a switches the request flag from OFF to ON (see A19 in FIG. 13).

  Next, the control determination unit 23b of the driving support control determination unit 23 sets the control flag to ON when the request determination unit 23a sets the request flag to ON (step ST505). Here, when the request flag is turned ON, the control determination unit 23b switches the control flag from OFF to ON (see C15 in FIG. 13). That is, the driving support control determination unit 23 determines that the intervention braking control by the driving support control unit 26 is necessary.

  Next, when the control flag is turned ON, the holding counter setting unit 27 calculates a predetermined holding period T based on the calculated TTC (step ST521). Here, the holding counter setting unit 27 calculates a predetermined holding period T based on the collision risk, that is, TTC, in order to set the holding counter number Nm in the holding counter 24. The holding counter setting unit 27 calculates the predetermined holding period T as the TTC approaches 0 (see FIG. 9).

  Next, the holding counter setting unit 27 sets the holding counter number Nm in the holding counter 24 based on the calculated predetermined holding period T (step ST522). Here, the holding counter setting unit 27 calculates the holding counter number Nm based on the collision risk, that is, the predetermined holding period T calculated based on the TTC, and the holding counter 24 stores the calculated holding counter number Nm. Set. The holding counter setting unit 27 sets the holding counter number Nm larger as the predetermined holding period T becomes longer. First, the holding counter setting unit 27 sets the holding counter number Nm3 calculated based on the predetermined holding period T3 calculated based on TTC2 in step ST522 as the holding counter number Nm in the holding counter 24 (FIG. 13). B23).

  Next, the control counter 25 performs counting (step ST507). Here, when the control determination unit 23b determines that the control flag is ON, the control counter 25 starts counting (see D18 in FIG. 13).

  Next, the driving support control unit 26 determines whether or not the control counter number Nc of the control counter 25 is equal to or greater than a predetermined control counter number Nc2 (step ST508). Next, when it is determined that the control counter number Nc of the control counter 25 is less than the predetermined control counter number Nc2, the driving support control unit 26 starts interventional braking control (step ST509). Here, when it is determined that the control counter number Nc of the control counter 25 is less than the predetermined control counter number Nc2, the driving support control unit 26 generates the intervention braking force F2 by the brake device 4 and controls the host vehicle to perform the intervention control. Power F2 is applied (see E19 in FIG. 13).

  Here, if the control flag remains in the ON state, the driving support control unit 26 determines that the control counter number Nc of the control counter 25 is equal to or greater than the predetermined control counter number Nc2 until the driving support control device 1-4. Continues to perform intervention braking control at each control cycle, that is, continues (step ST509). Therefore, during the intervention braking control by the driving support control unit 26, the TTC is calculated for each control cycle in step ST502, and the predetermined holding period T is calculated based on the TTC calculated for each control cycle in step ST521. In ST522, the holding counter number Nm is set in the holding counter 24 based on the predetermined holding period T calculated for each control cycle.

  On the other hand, when it is determined that the control counter number Nc of the control counter 25 is equal to or greater than the predetermined control counter number Nc2, the driving support control unit 26 stops the intervention braking control (step ST510).

  Here, during the intervention braking control by the driving support control unit 26, if an object that has been detected as an obstacle in the previous control cycle is not detected as an obstacle a plurality of times, each time the obstacle is no longer detected, a step is performed. It is determined that the TTC calculated in ST503 exceeds the predetermined value TTC2, and the request determination unit 23a turns off the request flag (step ST511). Here, if an obstacle present in the traveling direction of the host vehicle is not detected, the request determination unit 23a switches the request flag from ON to OFF every time the obstacle is not detected (see A20 and A22 in FIG. 13). ).

  Next, the holding counter 24 determines whether or not the control flag is ON (step ST512).

  Next, since it is determined that the control flag is ON, the holding counter 24 subtracts the holding counter (step ST513). Here, the holding counter number Nm set in the holding counter 24 is, as described above, the holding counter numbers Nm4 and Nm5 calculated based on the predetermined holding periods T4 and T5 calculated in the previous control cycle. It has become. Accordingly, the holding counter 24 starts subtraction of the holding counter number Nm (= Nm4, Nm5) set by the holding counter setting unit 27 every time no obstacle is detected (see B24 and B26 in FIG. 13).

  Next, the holding counter 24 determines whether or not the subtracted holding counter number Nm exceeds 0 (step ST514). Here, the holding counter 24 determines whether or not the predetermined holding periods T4 and T5 when the driving support control unit 26 performs the intervention braking control have elapsed.

  Next, when it is determined that the subtracted holding counter number Nm exceeds 0, the control counter 25 performs counting (step ST518). Here, if it is determined that the holding counter number Nm subtracted by the holding counter 24 exceeds 0, the control counter 25 continues counting (see D19 and D20 in FIG. 13).

  Next, the driving support control unit 26 determines whether or not the control counter number Nc of the control counter 25 is equal to or greater than a predetermined control counter number Nc2 (step ST519).

  Next, when it is determined that the control counter number Nc of the control counter 25 is less than the predetermined control counter number Nc2, the driving support control unit 26 continues the intervention braking control (step ST520). Here, when the intervention braking control is being performed, the driving support control unit 26 continues the intervention braking control if the predetermined holding periods T4 and T5 have not elapsed (see B24 and B28 in FIG. 13).

  Here, as described above, the driving support control unit 26 continues the intervention braking control, but the braking force within the period generated by the brake device 4 within the predetermined holding periods T4 and T5 is the normal intervention braking force F2. Rather than the intervention braking force F2. Therefore, the braking force applied to the host vehicle is smaller than the intervention braking force F2. In addition, when it is determined that the holding counter number Nm subtracted in step ST514 exceeds 0 for each control cycle, the driving support control device 1-4 further reduces the braking force within this period from the intervention braking force F2. (See the range of E20 to E21 and the range of E23 to E24 in FIG. 13). That is, the braking force applied to the host vehicle is made smaller than the intervention braking force as the predetermined holding periods T4 and T5 elapse. As a result, the driving support control unit 26 can bring the traveling state of the host vehicle closer to the state where the intervention braking control is not performed within the predetermined holding period T.

  If it is determined that the control counter number Nc of the control counter 25 is equal to or greater than the predetermined control counter number Nc2, the driving support control unit 26 stops the intervention braking control (step ST510).

  Here, during the intervention braking control by the driving support control unit 26, when an obstacle that is no longer detected is detected again, it is determined in step ST503 that the TTC calculated based on the same obstacle is TTC2 or less, In step ST504, the request flag is switched from OFF to ON again (see A21 and A23 in FIG. 13). In step ST521, a predetermined holding period T is calculated based on the calculated TTC, and in step ST522, the predetermined predetermined period is calculated. Based on the holding period T, the holding counter number Nm is set again in the holding counter 24 (see B25 and B27 in FIG. 13).

  On the other hand, if no obstacle is detected during the intervention braking control by the driving support control unit 26 and the obstacle no longer exists in the traveling direction of the host vehicle, the predetermined holding period T5 elapses. In ST511, the request flag is switched from ON to OFF (see A24 in FIG. 13), and it is determined that the holding counter number Nm subtracted in step ST514 exceeds 0 (see B27 in FIG. 13). When 1-4 repeats the control cycle, it is determined that the predetermined holding period T5 has elapsed and the subtracted holding counter number Nm is 0 (B28 in FIG. 13), and the control determining unit 23b turns off the control flag. (Step ST515). Here, the control determination unit 23b switches the control flag from ON to OFF when the predetermined holding period T5 elapses (see C14 in FIG. 13). That is, the driving support control determination unit 23 determines that the intervention braking control by the driving support control unit 26 is unnecessary.

  Next, the driving support control unit 26 stops the intervention braking control (see E26 in FIG. 13) (step ST516). Next, the control counter 25 clears the counter (step ST517). Here, when the control flag is switched from ON to OFF by the control determination unit 23b, the control counter 25 sets the control count number Nc to 0 (see D21 in FIG. 13).

  As described above, when the intervention braking control is performed in the driving support control device 1-4 according to the fourth embodiment, after the obstacle is detected, similarly to the driving support control device 1-1 according to the first embodiment. Even if the same obstacle cannot be detected, it is possible to prevent the intervention braking control from being interrupted once or being performed again. Thereby, a driver's discomfort can be suppressed. The predetermined holding period T differs depending on the type of the driving support control performed by the driving support control unit 26, that is, between the alarm braking control and the intervention braking control. When the intervention braking control is performed, the alarm braking control is performed. When the obstacle is not detected by the obstacle detection unit 21 and no obstacle exists in the traveling direction of the host vehicle, the vehicle can be stopped earlier than when the obstacle is being performed.

  In the case where the intervention braking control is performed in the driving support control device 1-4 according to the fourth embodiment, the predetermined holding period T is calculated according to the calculated collision risk. Here, when the obstacle detected by the obstacle detection unit 21 is no longer an obstacle, for example, when the detected obstacle no longer exists in the traveling direction of the host vehicle, the held intervention support control is stopped. The predetermined holding period T that is a period until the time of the collision is shortened as the calculated collision risk is higher, that is, as the TTC is shorter. Therefore, the timing at which the obstacle detected by the obstacle detection unit 21 is no longer an obstacle as the TTC becomes shorter as the timing of stopping the intervention braking control by the driving support control unit 26 (E20, E23 in FIG. 13) (FIG. 13). E22, 25). Furthermore, since the driving support control unit 26 brings the traveling state of the host vehicle closer to a state where the intervention braking control is not performed within a predetermined holding period T (for example, T4, T5), after the predetermined holding period T has elapsed (FIG. 13). Even if the intervention braking control is stopped at B24 and B29), the traveling state of the host vehicle can be brought close to the state where the intervention braking control is not performed in advance within the predetermined holding period T (E22 in FIG. 13). , E25). As a result, when the intervention braking control is being performed, the obstacle detection unit 21 does not detect the obstacle, and in the case where no obstacle is actually present in the traveling direction of the host vehicle, the collision risk is reduced. When the vehicle becomes higher, the vehicle can stop more quickly, and when the intervention braking force F2 suddenly stops being applied to the host vehicle after a predetermined holding period T has elapsed since the intervention braking force F2 is applied to the host vehicle ( It is possible to return the traveling state of the host vehicle to a state where the intervention braking control is no longer performed (X4 and X5 in FIG. 13) earlier than (see E22 and E25 in FIG. 13). Thereby, a driver's discomfort can be suppressed.

  In the second embodiment and the fourth embodiment, the case where the in-period braking force is decreased with the passage of the predetermined holding period T from the intervention braking force has been described, but the present invention is not limited to this. For example, the in-period braking force may be a constant braking force that is less than the intervention braking force. Further, for example, the current braking force may be used as the in-period braking force. In this case, the braking force applied to the host vehicle reaches the intervention braking force when the same obstacle cannot be detected after the obstacle is detected immediately after the intervention braking control is performed by the driving support control unit 26. Even if not, during the predetermined holding period T, the current braking force smaller than the intervention braking force is applied to the host vehicle as the braking force within the period.

  As described above, the driving support control device and the driving support control method according to the present invention include a driving support control device and a driving support control method that perform driving support control based on the detected collision risk between an obstacle and the host vehicle. In particular, after the obstacle is detected, even if the same obstacle cannot be detected, it is suitable for suppressing the driving support control from being interrupted once.

It is a figure which shows the structural example of the driving assistance control apparatus concerning invention. It is an operation | movement flowchart in the alarm braking control of the driving assistance control apparatus concerning Example 1. FIG. It is a figure which shows the relationship between a request | requirement flag, a holding | maintenance counter, a control flag, a control counter, braking force, and TTC. It is an operation | movement flowchart in the intervention braking control of the driving assistance control apparatus concerning Example 1. FIG. It is a figure which shows the relationship between a request | requirement flag, a holding | maintenance counter, a control flag, a control counter, braking force, and TTC. FIG. 10 is an operation flow diagram in intervention braking control of the travel support control apparatus according to the second embodiment. It is a figure which shows the relationship between a request | requirement flag, a holding | maintenance counter, a control flag, a control counter, braking force, and TTC. FIG. 12 is an operation flow diagram in intervention braking control of the travel support control apparatus according to the third embodiment. It is a figure which shows the relationship between TTC and the predetermined holding period T. It is a figure which shows the relationship between the predetermined | prescribed holding | maintenance period T and the holding | maintenance counter number Nm. It is a figure which shows the relationship between a request | requirement flag, a holding | maintenance counter, a control flag, a control counter, braking force, and TTC. FIG. 10 is an operation flow diagram in intervention braking control of the travel support control apparatus according to the fourth embodiment. It is a figure which shows the relationship between a request | requirement flag, a holding | maintenance counter, a control flag, a control counter, braking force, and TTC.

Explanation of symbols

1-1 to 1-4 Driving support control device 2 Control device 21 Obstacle detection unit (obstacle detection means)
22 Collision risk calculation unit (collision risk calculation means)
23 Driving support control determination unit (driving support control determination means)
23a request determination unit 23b control determination unit 24 holding counter 25 control counter 26 travel support control unit (travel support control means)
27 Holding counter setting unit (predetermined holding period calculating means)
3 Forward millimeter wave radar (obstacle detection means)
4 Brake Device 41 Brake Control Device 42 Brake Actuator 43 Brake 44 Brake Pedal 5 Yaw Rate Sensor 6 G Sensor 7 Vehicle Speed Sensor 8 Brake Sensor

Claims (10)

Obstacle detection means for detecting the position of an obstacle present in the traveling direction of the host vehicle;
Traveling support control means for performing traveling support control for supporting traveling of the host vehicle;
A collision risk calculating means for calculating a collision risk between the detected obstacle and the host vehicle;
A driving support control determining means for determining whether the driving support control is required or not based on the calculated collision risk;
In a driving support control device comprising:
The driving support control determining means determines that the control is required even if it is determined that the control is not required based on the calculated collision risk after determining that the control is required based on the calculated collision risk. A driving support control device that holds a predetermined holding period.   The driving support control apparatus according to claim 1, wherein the predetermined holding period varies depending on a type of the driving support control. A holding period calculating means for calculating the predetermined holding period;
The driving support control apparatus according to claim 1, wherein the holding period calculation unit calculates the predetermined holding period according to the calculated collision risk.   The driving support control apparatus according to claim 3, wherein the holding period calculation unit calculates the predetermined holding period shorter as the calculated collision risk is higher.   The travel support control device according to any one of claims 1 to 4, wherein the travel support control is an alarm control that warns a driver of the host vehicle.   The travel support control apparatus according to any one of claims 1 to 5, wherein the travel support control is an intervention brake control that applies an intervention braking force to the host vehicle.   The travel support control device according to claim 6, wherein the travel support control means reduces a braking force applied to the host vehicle within the predetermined holding period to be less than the intervention braking force.   The driving support control device according to claim 7, wherein the driving support control means reduces the braking force within the period with respect to the intervention braking force as the predetermined holding period elapses.   The travel assistance control apparatus according to any one of claims 1 to 8, wherein the collision risk degree is an inter-vehicle time between the detected obstacle and the host vehicle. In the driving support control method for performing driving support control for supporting driving of the host vehicle,
Detecting a position of an obstacle present in the traveling direction of the host vehicle;
A procedure for calculating a collision risk between the detected obstacle and the host vehicle;
A procedure for determining whether the driving support control is necessary or not based on the calculated collision risk,
After determining that the control is required based on the calculated collision risk, and determining that the control is not required based on the calculated collision risk, a procedure for holding the state of the control required for a predetermined holding period;
A driving support control method comprising:

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