Vehicle travel control device and method

Abstract

The invention relates to a travel control apparatus and method for a vehicle. The travel control apparatus includes: a sensor that detects a steering operation; a target information acquisition device that acquires information about a target around the vehicle; an automatic braking device for automatically braking the vehicle; and a driving assistance ECU that controls the automatic brake device. The driving support ECU determines that there is a possibility that the vehicle is deviated to the outside of the road on the basis of the target information acquired by the target information acquisition device, and determines that a steering operation is performed in the direction in which the vehicle is deviated to the outside of the road on the basis of the steering operation detected by the sensor. An automatic braking device is operated to automatically brake a vehicle.

Description

Technical Field

[0001] The present invention relates to a vehicle travel control device and method used in a vehicle such as an automobile, and more particularly to a vehicle travel control device and method for suppressing a situation in which the vehicle deviates from a road. Background Art

[0002] As one of the driving control devices for vehicles such as automobiles, there is a known lane departure prevention device that prevents the vehicle from leaving the lane by automatically braking the vehicle or issuing an alarm when there is a possibility that the vehicle will leave the lane, and does not automatically brake or issue an alarm when the driver performs a steering operation.

[0003] For example, Japanese Patent Application Laid-Open No. 2009-116693 describes a technique for changing the conditions for canceling an alarm according to the driver's level of alertness when the driver performs a steering operation in a situation where there is a possibility that the vehicle may deviate from the lane.

[0004] According to this lane departure prevention device, even if there is a possibility that the vehicle may depart from the lane, it is possible to prevent automatic braking or warning from being performed unnecessarily when the driver performs a steering operation to actively intend to depart from the lane. Summary of the invention

[0005] Even if the driver performs a steering operation under a situation where there is a possibility that the vehicle will leave the lane, the driver does not necessarily actively want to leave the lane. Preferably, when the driver does not actively want to leave the lane, the automatic braking and the warning are not cancelled even if the driver performs a steering operation.

[0006] In particular, when there is a possibility that the vehicle may deviate from the road, by determining whether the direction of the steering operation performed by the driver is based on the direction of the steering operation to deviate the vehicle from the road, it is possible to determine whether the driver actively intends to leave the lane.

[0007] The present invention provides a vehicle driving control device and method, which are improved to reduce the possibility of vehicle deviation from the road even if the driver performs steering operation under the condition that there is a possibility that the vehicle may deviate from the road, when the steering operation is not a steering operation that actively intends to make the vehicle deviate from the lane.

[0008] According to the present invention, a vehicle driving control device (100) is provided, comprising: a steering operation detection device (driving operation sensor 60) for detecting the driver's steering operation; a target object information acquisition device (15) for acquiring information about target objects around the vehicle (102); an automatic braking device (36) for automatically braking the vehicle; and a control unit (driving assistance ECU 10) for controlling the automatic braking device.

[0009] The control unit (driving assistance ECU 10) is configured to operate the automatic braking device to perform automatic braking of the vehicle (S140, S170) when it is determined that there is a possibility of the vehicle departing from the road based on the information of the target object obtained by the target object information acquisition device (S20) and when it is determined that a steering operation has been performed in the direction of the vehicle departing from the road based on the steering operation detected by the steering operation detection device (S30).

[0010] In addition, according to the present invention, there is provided a vehicle driving control method, comprising: obtaining information of target objects around the vehicle (102), determining the possibility of the vehicle escaping from the road based on the obtained information of the target objects (S20); and when it is determined that there is a possibility of separation (S110), operating an automatic braking device to perform automatic braking steps (S140, S170) to automatically brake the vehicle.

[0011] The vehicle driving control method also detects the driver's steering operation, and even if it is determined that there is a possibility of separation (S20), when it is determined that a steering operation has been performed in a direction other than the direction in which the vehicle is separated from the road (S30), automatic braking is not performed (S60). When it is determined that there is a possibility of separation (S20) and when it is determined that a steering operation has been performed in a direction in which the vehicle is separated from the road (S30), automatic braking is performed (S70, S140, S170).

[0012] According to the vehicle driving control device and method, information about the target object around the vehicle is obtained, and the possibility of the vehicle going off the road is determined based on the obtained information about the target object. Furthermore, when it is determined that there is a possibility of the vehicle going off the road and it is determined that a steering operation in the direction of the vehicle going off the road is performed, automatic braking is performed.

[0013] In a situation where there is a possibility that the vehicle will go off the road, even if the driver performs a steering operation, if the direction of the steering operation is a direction that causes the vehicle to go off the road, it can be considered that the steering operation is not a steering operation performed by the driver to actively control the driving direction of the vehicle. According to the vehicle driving control device and method described above, automatic braking is performed in this case, so compared with a conventional driving control device that does not perform automatic braking regardless of the steering direction when the steering operation is performed, the possibility of the vehicle going off the road can be reduced.

[0014] Furthermore, the "reduction in the possibility of the vehicle running off the road" is achieved by "automatically braking the vehicle", and the automatic steering operation that opposes the steering operation performed by the driver, that is, the automatic steering of the steering wheel, is not performed. Therefore, even if a situation occurs in which the direction of the vehicle running off the road and / or the direction of the steering operation is not properly determined, the automatic steering operation is not performed inappropriately, and the driving direction of the vehicle is not inappropriately controlled.

[0015] [Technical solution of the invention]

[0016] In one technical solution of the present invention, the control unit (driving assistance ECU 10) is configured to perform automatic braking (S70, S140, S170) when it is determined that the possibility of departure is greater than a first departure reference value (S120) and when it is determined that the associated value of the steering operation is greater than a first steering reference value (S10).

[0017] According to the above technical solution, when it is determined that the possibility of separation is greater than the first separation reference value and the associated value of the steering operation is greater than the first steering reference value, automatic braking is performed. Therefore, even if it is determined that the possibility of separation is greater than the first separation reference value, when it is determined that the associated value of the steering operation is less than the first steering reference value, automatic braking is not performed, thereby avoiding the situation where automatic braking is performed unnecessarily.

[0018] The steering operation-related value is an index value for determining whether the driver has performed a steering operation, and may be a steering torque, a steering angle, or the like.

[0019] In another technical solution of the present invention, the vehicle driving control device (100) further includes a driving state information acquisition device (monitoring camera 16) for acquiring information on the driver's driving state, and the control unit (driving assistance ECU 10) is configured to determine whether the driver's driving state is a careless driving state (S2) based on the driving state information acquired by the driving state information acquisition device, and when it is determined that the driver's driving state is not a careless driving state, automatic braking is performed (S70, S140, S170) when it is determined that the possibility of separation is greater than a first separation reference value (S120) and when it is determined that the associated value of the steering operation is greater than a first steering reference value (S4, S10); when it is determined that the driver's driving state is a careless driving state, automatic braking is performed when it is determined that the possibility of separation is greater than a first separation reference value (S120) and when it is determined that the associated value of the steering operation is greater than a second steering reference value that is smaller than the first steering reference value (S6, S10).

[0020] Generally, when the driver's driving state is a distracted driving state, the associated value of the steering operation becomes smaller than when the driver is awake. Therefore, it is preferred that the reference value for determining whether the driver has performed the steering operation based on the associated value of the steering operation is smaller when the driver's driving state is a distracted driving state than when the driver is awake.

[0021] According to the above technical solution, when it is determined that the driving state of the driver is not the careless driving state, automatic braking is performed when it is determined that the possibility of departure is greater than the first departure reference value and the associated value of the steering operation is greater than the first steering reference value. On the other hand, when it is determined that the driving state of the driver is the careless driving state, automatic braking is performed when it is determined that the possibility of departure is greater than the first departure reference value and the associated value of the steering operation is greater than the second steering reference value which is smaller than the first steering reference value.

[0022] Therefore, compared with a case where the steering reference value is constant regardless of whether the driver's driving state is a careless driving state, it is possible to appropriately determine whether the driver has performed a steering operation based on the steering operation correlation value even when the driver's driving state is a careless driving state.

[0023] Moreover, in another technical solution of the present invention, the control unit (driving assistance ECU 10) is configured to, when performing automatic braking, perform automatic braking with a first deceleration when it is determined that the possibility of separation is less than a second separation reference value that is larger than the first separation reference value (S120, S130), and perform automatic braking with a second deceleration that is higher than the first deceleration when it is determined that the possibility of separation is greater than the second separation reference value (S120, S130), (S170).

[0024] Generally, in order to reduce the possibility of the vehicle running off the road by automatic braking, it is preferred that the higher the possibility of the vehicle running off the road, the higher the deceleration of the vehicle by automatic braking.

[0025] According to the above technical solution, when it is determined that the possibility of separation is less than the second separation reference value that is greater than the first separation reference value, automatic braking is performed at the first deceleration, and when it is determined that the possibility of separation is greater than the second separation reference value, automatic braking is performed at the second deceleration that is greater than the first deceleration. Thus, compared with a case where the deceleration of the vehicle under automatic braking is constant regardless of the level of the possibility of separation, the deceleration of the vehicle under automatic braking can be appropriately controlled.

[0026] In addition, in the present application, "off-road" means "on the non-driving area side relative to the boundary between the driving area where the vehicle can drive and the non-driving area where the vehicle cannot drive". "Departure from the road" means "the vehicle's pre-set reference position moves from the driving area to the non-driving area". The lane where the vehicle is driving, the roadside strip where the vehicle can drive, the avoidance lane, etc. can be regarded as the driving area. In contrast, the area outside the road, the roadside strip where the vehicle cannot drive, etc. can be regarded as the non-driving area.

[0027] In the above description, in order to facilitate the understanding of the present invention, the names and / or figure marks used in the embodiments are added in parentheses to the configurations of the invention corresponding to the embodiments described later. However, the constituent elements of the present invention are not limited to the constituent elements of the embodiments corresponding to the names and / or figure marks added in parentheses. Other purposes, other features and incidental advantages of the present invention should be easily understood by referring to the following drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, wherein like reference numerals represent like elements, and wherein:

[0029] Figure 1 It is a schematic configuration diagram showing an embodiment of a vehicle travel control device according to the present invention.

[0030] Figure 2 This is a flowchart corresponding to the lane departure and steering determination control routine in the first embodiment.

[0031] Figure 3 This is a flowchart corresponding to the automatic braking control routine for lane departure prevention in the first embodiment.

[0032] Figure 4 This is a flowchart corresponding to a main part of the lane departure and steering determination control routine in the second embodiment.

[0033] Figure 5 Detailed description is a flowchart showing a routine for determining whether the driver is in a careless driving state.

[0034] Fig. 6A This is a diagram showing a situation where there is a possibility that the vehicle will deviate from the road, which is a drivable area, to an undrivable area.

[0035] Figure 6B This is a diagram showing a situation where there is a possibility that the vehicle will deviate from the road, which is a drivable area, to an undrivable area. DETAILED DESCRIPTION

[0036] Hereinafter, a vehicle travel control device and a vehicle travel control method according to embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0037] like Figure 1 As shown, the driving control device 100 according to the embodiment of the present invention is applied to a vehicle 102, and includes a driving assistance ECU 10. The vehicle 102 is a vehicle capable of automatic driving, and is provided with a drive ECU 20, a brake ECU 30, an electric power steering ECU 40, and an instrument ECU 50. ECU refers to an electronic control unit (Electronic Control Unit) having a microcomputer as a main part. In addition, in the following description, the electric power steering is referred to as EPS.

[0038] The microcomputer of each ECU includes a CPU, ROM, RAM, a readable and writable non-volatile memory (N / M), and an interface (I / F). The CPU implements various functions by executing instructions (programs, routines) stored in the ROM. Moreover, these ECUs are connected to each other via CAN (Controller Area Network) 104 in a manner that can exchange data (can communicate). Therefore, the detection values ​​of sensors (including switches) connected to a specific ECU are also sent to other ECUs.

[0039] The driving assistance ECU 10 is a central control device that performs driving assistance driving control such as lane departure prevention control and vehicle-to-vehicle distance control. In the embodiment, the driving assistance ECU 10 cooperates with other ECUs to perform lane departure prevention control as described in detail below. The driving control of the embodiment is performed as part of the lane departure prevention control.

[0040] The driving support ECU 10 is connected to a camera sensor 12, a radar sensor 14, a monitoring camera 16, and a switch 18. The camera sensor 12 and the radar sensor 14 include a plurality of camera devices and a plurality of radar devices, respectively. The camera sensor 12 and the radar sensor 14 function as a target object information acquisition device 15 that acquires target object information around the vehicle 102.

[0041] Although not shown in the figure, each camera device of the camera sensor 12 includes a camera unit for photographing the surroundings of the vehicle 102 and a recognition unit for analyzing the image data photographed by the camera unit to recognize targets such as white lines on the road and other vehicles. The recognition unit provides information related to the recognized target to the driving assistance ECU 10 at predetermined intervals.

[0042] Each radar device of the radar sensor 14 is equipped with a radar transceiver and a signal processing unit (not shown). The radar transceiver radiates radio waves in the millimeter wave band (hereinafter referred to as "millimeter waves") and receives millimeter waves (i.e., reflected waves) reflected by three-dimensional objects (e.g., other vehicles, bicycles, etc.) within the radiation range. The signal processing unit provides the driving assistance ECU 10 with information indicating the distance between the vehicle and the three-dimensional object, the relative speed between the vehicle and the three-dimensional object, and the relative position (direction) of the three-dimensional object relative to the vehicle at predetermined intervals based on the phase difference between the transmitted millimeter wave and the received reflected wave, the attenuation level of the reflected wave, and the time from transmitting the millimeter wave to receiving the reflected wave. In addition, LiDAR (Light Detection And Ranging) may be used instead of the radar sensor 14 or in addition to the radar sensor 14.

[0043] The monitoring camera 16 is provided on the instrument panel or the steering column, and includes a camera unit for photographing the driver's face, and an image processing unit for processing the image data of the driver's face photographed by the camera unit. The image processing unit provides information of the image data of the driver's face to the driving assistance ECU 10 at predetermined intervals. Thus, the monitoring camera 16 functions as a driver monitoring camera.

[0044] The CPU of the driving assistance ECU 10 determines the driver's unconsciousness based on the driver's eye closing rate per minute, eye opening condition, blinking frequency, or eye movement based on the information of the driver's facial image data. Unconsciousness is the degree to which the driver is distracted and unsuitable for driving due to lack of sleep, etc. There is no particular limitation on the method for determining unconsciousness, and any known method in the technical field can be used. In addition, when determining the unconsciousness, at least one of the driver's grip pressure on the steering wheel, the pressure on the armrest, the heart rate, the electromyographic information, and the electroencephalogram can be considered.

[0045] The switch 18 is set as Figure 1 The driving assistance ECU 10 is operated by the driver at a position that can be operated by the driver, such as a steering wheel (not shown). As described in detail below, the driving assistance ECU 10 executes the lane departure suppression control when the switch 18 is turned on.

[0046] The drive ECU 20 is connected to a drive device 22 that accelerates the vehicle 102 by applying a driving force to a drive wheel 24. The drive ECU 20 normally controls the drive device 22 so that the driving force generated by the drive device 22 changes according to the driver's driving operation, and when receiving a command signal from the driving assistance ECU 10, controls the drive device 22 based on the command signal.

[0047] The brake ECU 30 is connected to a brake device 32 for decelerating the vehicle 102 by applying a braking force to the wheels 34. The brake ECU 30 normally controls the brake device 32 so that the braking force generated by the brake device 32 changes according to the driver's brake operation. When receiving a command signal from the driving assistance ECU 10, the brake device 32 is controlled based on the command signal to perform automatic braking.

[0048] Thus, the brake ECU 30 and the brake device 32 cooperate with each other and function as an automatic brake device 36. In addition, when a braking force is applied to the wheels by lane departure suppression control or the like, the brake ECU 30 and the brake device 32 are connected to the vehicle. Figure 1 The brake indicator light (not shown) comes on.

[0049] The EPS·ECU 40 is connected to an EPS device 42. The EPS·ECU 40 controls the EPS device 42 based on the steering torque Ts and the vehicle speed V detected by the driving operation sensor 60 and the vehicle state sensor 70 described later, by a method known in the art, thereby controlling the steering assist torque and reducing the steering burden of the driver. In addition, the EPS·ECU 40 can steer the steering wheel 44 as needed by controlling the EPS device 42. Thus, the EPS·ECU 40 and the EPS device 42 function as an automatic steering device that automatically steers the steering wheel as needed.

[0050] The meter ECU 50 is connected to a touch panel display 52 that displays the status of control performed by the driving assistance ECU 10, and an alarm device 54 that issues an alarm. The display 52 may be, for example, a multi-information display that displays meters and various information, or a display of a navigation device. The display 52 may display the status of the lane departure suppression control when receiving a signal from the driving assistance ECU 10.

[0051] The warning device 54 operates when it is determined that there is a possibility that the vehicle 102 will deviate from the road, and issues an alarm as one of the lane departure suppression controls, that is, an alarm that means that there is a possibility that the vehicle 102 will deviate from the road. The warning device 54 may be any one of an alarm device that issues a visual alarm such as an alarm lamp, an alarm device that issues an auditory alarm such as an alarm buzzer, and an alarm device that issues a physical alarm such as seat vibration, or any combination thereof.

[0052] The driving operation sensor 60 and the vehicle state sensor 70 are also connected to the CAN 104. The information detected by the driving operation sensor 60 and the vehicle state sensor 70 (referred to as sensor information) is sent to the CAN 104. The sensor information sent to the CAN 104 can be used appropriately in each ECU. In addition, the sensor information may be information of a sensor connected to a specific ECU, and may be sent from the specific ECU to the CAN 104.

[0053] The driving operation sensor 60 includes a driving operation amount sensor for detecting the operation amount of the accelerator pedal, a braking operation amount sensor for detecting the master cylinder pressure or the pedal force on the brake pedal, and a brake switch for detecting the operation of the brake pedal. In addition, the driving operation sensor 60 includes a steering angle sensor for detecting the steering angle θ, a steering torque sensor for detecting the steering torque Ts, and a turn signal switch for indicating the operation of the turn signal lever and the direction of the operation.

[0054] The vehicle state sensor 70 includes a vehicle speed sensor for detecting a vehicle speed V of the vehicle 102 , a longitudinal acceleration sensor for detecting acceleration in the longitudinal direction of the vehicle, a lateral acceleration sensor for detecting lateral acceleration of the vehicle, and a yaw rate sensor for detecting a yaw rate of the vehicle.

[0055] [First embodiment]

[0056] In the first embodiment, the ROM of the driving assistance ECU 10 stores Figure 2 In the first embodiment, the ROM of the driving assistance ECU 10 stores the lane departure and steering determination control program corresponding to the flowchart shown in FIG. Figure 3 The automatic braking control procedure for lane departure prevention corresponds to the flowchart shown in FIG. Figure 2 and Figure 3 The flowcharts shown respectively are executed to execute lane departure and steering determination control, and lane departure prevention automatic braking control.

[0057] <Lane departure and steering judgment control( Figure 2 )>

[0058] Next, refer to Figure 2 The flowchart shown in FIG. 1 is used to explain the lane departure and steering determination control in the first embodiment. When the switch 18 is turned on, Figure 2 The lane departure and steering determination control in the flowchart shown is repeatedly executed at predetermined time intervals by the CPU of the driving support ECU 10. In addition, the flag F is reset to 0 when the lane departure and steering determination control is started.

[0059] First, in step S10, the CPU determines whether the absolute value of the steering torque Ts is greater than or equal to the reference value Tsc, that is, whether the driver has performed a steering operation. When a negative determination is made, the control proceeds to step S60, and when an affirmative determination is made, the control proceeds to step S20. In addition, the reference value Tsc may be a positive constant or a positive value that is variably set according to the vehicle speed V so that it becomes smaller as the vehicle speed V increases.

[0060] In step S20, the CPU determines whether there is a possibility of lane departure, that is, whether the vehicle 102 is about to leave the road, based on the target object information around the vehicle 102 obtained by the target object information acquisition device 15, for example, by a method known in the art. When a negative determination is made, the control proceeds to step S60, and when an affirmative determination is made, the control proceeds to step S30.

[0061] In step S30, the CPU determines whether the direction of the driver's steering operation is the direction of the vehicle 102 going off the road determined in step S20, based on the steering angle θ detected by the steering angle sensor and its change, for example. If a negative determination is made, the control proceeds to step S60, and if an affirmative determination is made, the control proceeds to step S40.

[0062] In step S40, the CPU determines whether the driver has operated the turn signal lever in the direction corresponding to the steering direction determined in step S30 based on the presence or absence of the turn signal lever operation indicated by the turn signal switch and the direction of the operation. When an affirmative determination is made, the control proceeds to step S60, and when a negative determination is made, the control proceeds to step S50.

[0063] In step S50, the CPU determines whether the area ahead of the direction in which the vehicle 102 deviates from the road determined in step S20 is a non-driving area, that is, an area in which the vehicle cannot travel, based on the target object information around the vehicle 102 obtained by the target object information acquisition device 15, for example. When a negative determination is made, in step S60, the flag F is reset to 0, and when a positive determination is made, the flag F is set to 1. In addition, "the flag F is 1" indicates that "there is a possibility that the vehicle 102 deviates from the road, and control to suppress the deviating is required."

[0064] <Automatic Braking Control with Lane Departure Prevention( Figure 3 )>

[0065] Next, refer to Figure 3 The flowchart shown in FIG. 1 illustrates the braking force control for lane departure prevention in the first embodiment. When the switch 18 is turned on, Figure 3The braking force control in the flowchart shown is repeatedly executed by the CPU of the driving assistance ECU 10 at predetermined time intervals.

[0066] First, in step S110, the CPU determines whether flag F is 1, that is, whether there is a possibility that the vehicle 102 will deviate from the road and control to suppress the deviating is necessary. If a negative determination is made, this control is temporarily terminated, and if an affirmative determination is made, this control proceeds to step S120.

[0067] In step S120, the CPU calculates the time Te until the vehicle deviates from the road, for example, based on the target object information around the vehicle 102 obtained by the target object information acquisition device 15, by a method known in the technical field. Furthermore, the CPU determines whether the time Te is less than the first reference time Tec1 (positive constant), that is, whether the possibility of the vehicle deviating from the road is greater than the first reference value. When a negative determination is made, the control is temporarily terminated, and when a positive determination is made, the control proceeds to step S130. In addition, the time Te can be calculated, for example, based on the lateral speed of the vehicle 102 as the time until the vehicle's pre-set reference position reaches the boundary between the road and the off-road area.

[0068] In step S130, the CPU determines whether the time Te is less than the second reference time Tec2 (a positive constant smaller than Tec1), that is, whether the possibility of the vehicle escaping from the road is greater than the second reference value. When a positive determination is made, the control proceeds to step S150. When a negative determination is made, that is, when it is determined that the possibility of the vehicle escaping from the road is greater than the first reference value and less than the second reference value, the control proceeds to step S140.

[0069] In step S140, the CPU outputs a command signal to the brake ECU 30, thereby executing slow braking control by automatic braking by the automatic brake device 36 in such a manner that the deceleration Gb of the vehicle 102 becomes the first deceleration Gb1 (a positive constant with the deceleration direction as positive). In addition, the CPU outputs a command signal to the meter ECU 50, thereby generating an intermittent alarm through the buzzer device.

[0070] In step S150, the CPU determines whether the driver has performed a brake operation based on the detection result of the brake operation amount sensor or the condition of the brake switch. If a positive determination is made, this control is temporarily terminated, and if a negative determination is made, this control proceeds to step S160.

[0071] In step S160, the CPU determines whether the driver has performed a steering operation in the direction opposite to the direction in which the vehicle 102 deviates from the road, based on the steering angle θ detected by the steering angle sensor and its change, for example. When a positive determination is made, this control is temporarily terminated, and when a negative determination is made, this control proceeds to step S170. In addition, when the driver has not performed a steering operation, a negative determination is made.

[0072] In step S170, the CPU outputs a command signal to the brake ECU 30, thereby executing a strong braking control by automatic braking by the automatic brake device 36 so that the deceleration Gb of the vehicle 102 becomes the second deceleration Gb2 (a positive constant greater than Gb1). In addition, the CPU outputs a command signal to the meter ECU 50, thereby generating a continuous sound alarm through the buzzer device.

[0073] [Second embodiment]

[0074] In the second embodiment, the ROM of the driving assistance ECU 10 stores Figure 4 The flowchart of the main part shows the lane departure and steering determination control program. In addition, the lane departure prevention automatic braking control program in the second embodiment is the same as the lane departure prevention automatic braking control program in the first embodiment. The driving control method involved in the second embodiment is carried out according to Figure 4 and Figure 3 The flowcharts shown respectively are executed to execute lane departure and steering determination control, and lane departure prevention automatic braking control.

[0075] <Lane departure and steering judgment control( Figure 4 )>

[0076] like Figure 4 As shown, before step S10, steps S2 and S4, or steps S2 and S6 are executed, and steps S10 to S70 are executed in the same manner as in the first embodiment.

[0077] In step S2, the CPU determines whether the driver is in a careless driving state. When a negative determination is made, in step S4, the reference value Tsc used for the determination of step S10 is set to the standard reference value Tscn. On the other hand, when a positive determination is made, in step S6, the reference value Tsc is set to a reference value Tscs for careless driving that is smaller than the standard reference value Tscn. When step S4 or S6 is completed, the control proceeds to step S10. In addition, the reference values ​​Tscn and Tscs may be positive constants or positive values ​​that are variably set according to the vehicle speed V so that they become smaller as the vehicle speed V increases.

[0078] <Judgment of Casual Driving State>

[0079] The determination of whether the driver is in a careless driving state can be performed based on information of image data of the driver's face captured by the monitoring camera 16 by any method known in the art. Figure 5 The routine corresponding to the flowchart shown in the figure is performed.

[0080] In step S210, the CPU determines whether the driver's eyes are closed. If an affirmative determination is made, the control proceeds to step S250, and if a negative determination is made, the control proceeds to step S220.

[0081] In step S220, the CPU determines whether the driver is looking to the side. If a positive determination is made, the control proceeds to step S250, and if a negative determination is made, the control proceeds to step S230. In addition, the driver may be determined to be looking to the side when the time and frequency in which the direction of the driver's line of sight is not in front of the vehicle are greater than the respective corresponding reference values.

[0082] In step S230, the CPU determines whether the driver is sleepy. If a negative determination is made, in step S240, it is determined that the driver is not in a distracted driving state, and if a positive determination is made, in step S250, it is determined that the driver is in a distracted driving state. In addition, when the direction of the driver's line of sight is downward than "forward", and when the frequency of the driver's blinking and yawning is above the respective corresponding reference values, it can be determined that the driver is sleepy.

[0083] <Effects of the First and Second Embodiments>

[0084] As mentioned above, in a situation where there is a possibility that the vehicle will deviate from the road, even if the driver performs steering operation, if the direction of the steering operation is to cause the vehicle to deviate from the road, it can be considered that the steering operation is not a steering operation performed by the driver actively wanting to control the direction of the vehicle.

[0085] According to the first and second embodiments, when the direction of the steering operation is determined, and it is determined that there is a possibility that the vehicle will deviate from the road (S10), and when it is determined that the steering operation is performed in the direction in which the vehicle will deviate from the road (S30), automatic braking is performed. Thus, compared with a conventional driving control device that does not perform automatic braking regardless of the steering direction when the steering operation is performed, the possibility of the vehicle deviating from the road can be reduced.

[0086] For example, Fig. 6A , Figure 6BThe figure shows a situation where the vehicle 102 may deviate from the road 104 which is a drivable area to the drivable area 106. In particular, Fig. 6A The figure shows a situation where the driver operates the steering wheel 108 in a direction away from the un-drivable area 106. Figure 6B The diagram shows a situation in which the driver operates the steering wheel 108 in the direction of the area 106 where the vehicle cannot travel.

[0087] exist Fig. 6A In the situation shown, a positive determination is made in step S20, a negative determination is made in step S30, and the flag F is reset to 0 in step S60. Therefore, a negative determination is made in step S110, so steps S140 and S170 are not executed, and automatic braking and alarm are not issued. Therefore, it is possible to avoid unnecessary automatic braking and alarm issuance in a situation where the driver wants to avoid the vehicle running off the road by steering operation.

[0088] In contrast, Figure 6B In the situation shown, positive determination is made in steps S20 and S30, and in step S70, flag F is set to 1. Thus, positive determination is made in step S110, so steps S140 and S170 are executed to perform automatic braking and issue an alarm. Therefore, the driver's attention can be drawn and the vehicle can be decelerated, so the possibility of the vehicle 102 escaping from the non-travelable area 106 can be reduced.

[0089] In addition, the possibility of the vehicle 102 running off the road is reduced by automatic braking of the vehicle and issuing of an alarm (S140, S170), and the automatic steering operation that opposes the steering operation performed by the driver, that is, the automatic steering of the steering wheel, is not performed. Therefore, even if a situation occurs in which the direction of the vehicle running off the road and / or the direction of the steering operation is not properly determined, the automatic steering operation is not inappropriately performed, and the driving direction of the vehicle is not inappropriately controlled.

[0090] In addition, according to the first and second embodiments, when it is determined that the possibility of separation is greater than the first separation reference value (S120) and it is determined that the associated value of the steering operation is greater than the first steering reference value (S10), automatic braking is performed (S70, S140, S170). Therefore, even if it is determined that the possibility of separation is greater than the first separation reference value, when it is determined that the associated value of the steering operation is less than the first steering reference value, automatic braking is not performed, so that it is possible to avoid unnecessary automatic braking.

[0091] In addition, according to the first and second embodiments, when it is determined that the possibility of separation is less than the second separation reference value greater than the first separation reference value (S120, S130), automatic braking is performed at the first deceleration Gb1 (S140), and when it is determined that the possibility of separation is greater than the second separation reference value (S120, S130), automatic braking is performed at the second deceleration Gb2 greater than the first deceleration (S170). Thus, compared with a case where the deceleration of the vehicle under automatic braking is constant regardless of the level of the possibility of separation, the deceleration of the vehicle under automatic braking can be appropriately controlled.

[0092] In particular, according to the second embodiment, when it is determined that the driving state of the driver is not the careless driving state (S2), when it is determined that the possibility of departure is greater than the first departure reference value (S120) and when it is determined that the associated value of the steering operation is greater than the first steering reference value (S4, S10), automatic braking is performed (S70, S140, S170). In contrast, when it is determined that the driving state of the driver is the careless driving state (S2), when it is determined that the possibility of departure is greater than the first departure reference value (S120) and when it is determined that the associated value of the steering operation is greater than the second steering reference value that is smaller than the first steering reference value (S6, S10), automatic braking is performed.

[0093] Therefore, compared with a case where the steering reference value is constant regardless of whether the driver's driving state is a careless driving state, even when the driver's driving state is a careless driving state, it is possible to appropriately determine whether the driver has performed a steering operation based on the steering operation correlation value.

[0094] As mentioned above, although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to the above-mentioned embodiments, and it is obvious to those skilled in the art that various other embodiments can be implemented within the scope of the present invention.

[0095] For example, in the first and second embodiments described above, when it is determined in step S130 that the time Te is less than the second reference time Tec2, the slow braking control is performed in step S140 so that the deceleration Gb of the vehicle 102 becomes the first deceleration Gb1. However, steps S130 and S140 may be omitted.

[0096] In the first and second embodiments described above, an intermittent alarm is sounded in step S140, and a continuous alarm is sounded in step S170. However, the sounding of the alarm may be omitted.

[0097] Furthermore, in the first and second embodiments described above, automatic steering for reducing the possibility of the vehicle running off the road is not performed in steps S140 and S170. However, at least in step S170, automatic steering for reducing the possibility of the vehicle running off the road may be performed in addition to automatic braking. Furthermore, when automatic steering is performed in steps S140 and S170, the control amount of automatic steering in step S170 may be set to be larger than the control amount of automatic steering in step S140.

Claims

1. A vehicle driving control device, comprising: A steering operation detection device to detect the driver's steering operation; a target object information acquisition device for acquiring information of target objects around the vehicle; an automatic braking device for automatically braking the vehicle; and a control unit for controlling the automatic braking device. The control unit is configured to perform automatic braking by activating the automatic braking device to automatically brake the vehicle when it is determined that there is a possibility of the vehicle departing from the road based on the information of the target object obtained by the target object information acquisition device, and when it is determined that a steering operation has been performed in the direction of the vehicle departing from the road based on the steering operation detected by the steering operation detection device.

2. The vehicle travel control device according to claim 1, The control unit is configured to perform the automatic braking when it is determined that the possibility of departure is equal to or greater than a first departure reference value and when it is determined that the value associated with the steering operation is equal to or greater than a first steering reference value.

3. The vehicle travel control device according to claim 2, The vehicle travel control device further includes a driving state information acquisition device for acquiring information on the driving state of the driver. The control unit is configured to determine whether the driver's driving state is a careless driving state based on the driving state information obtained by the driving state information acquisition device, and if it is determined that the driver's driving state is not a careless driving state, perform the automatic braking when it is determined that the possibility of departure is greater than the first departure reference value and the associated value of the steering operation is greater than the first steering reference value, and if it is determined that the driver's driving state is a careless driving state, perform the automatic braking when it is determined that the possibility of departure is greater than the first departure reference value and the associated value of the steering operation is greater than a second steering reference value which is smaller than the first steering reference value.

4. The vehicle travel control device according to claim 2 or 3, The control unit is configured to, when performing the automatic braking, perform the automatic braking at a first deceleration when it is determined that the possibility of separation is less than a second separation reference value that is larger than the first separation reference value, and to perform the automatic braking at a second deceleration that is higher than the first deceleration when it is determined that the possibility of separation is greater than the second separation reference value.

5. A vehicle driving control method, comprising: A step of acquiring information of a target object around the vehicle and determining a possibility of the vehicle departing from the road based on the acquired information of the target object; and when it is determined that there is a possibility of the separation, performing an automatic braking step of activating the automatic braking device to automatically brake the vehicle, In the driving control method of the vehicle, the driver's steering operation is also detected. Even if it is determined that the possibility of separation exists, the automatic braking is not performed when it is determined that the steering operation is performed in a direction other than the direction in which the vehicle separates from the road. The automatic braking is performed when it is determined that the possibility of separation exists and when it is determined that the steering operation is performed in a direction in which the vehicle separates from the road.

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