Travel control device and method for vehicle

Abstract

The present invention relates to an apparatus and a method for controlling the travel of a vehicle, which are configured so as to control the travel of a vehicle when a navigation device detects a first intersection and a second intersection which are located on a travel road on which the vehicle travels within a range of a reference distance from the vehicle and which are separated from each other. When it is estimated that the vehicle will pass through the first intersection along the travel road and that the time required for the vehicle to reach the first intersection is less than a first reference value, it is determined that the deceleration permission condition is satisfied, and when it is determined that the deceleration permission condition is satisfied, the deceleration permission condition is not satisfied. When it is determined that the time required for the vehicle to arrive at the second intersection is less than the second reference value, deceleration control for decelerating the vehicle is started.

Description

Technical Field

[0001] The present invention relates to a driving control device for a vehicle such as an automobile, and more particularly to a driving control device and method for a vehicle that performs deceleration control for automatically decelerating the vehicle. Background Art

[0002] As one of driving control devices for vehicles such as automobiles, there is known a driving control device that assists a driver's driving by executing deceleration control to automatically decelerate the vehicle when the vehicle arrives at an intersection.

[0003] For example, Japanese Patent No. 6881323 describes a driving control device that increases the degree of collision avoidance driving assistance when it is predicted that the vehicle will turn right or left at an intersection and it is inferred that the driver of the following vehicle believes that the vehicle will not turn right or left at the intersection.

[0004] According to this driving control device, when the host vehicle is predicted to turn right or left at an intersection, the degree of collision avoidance driving assistance can be changed according to whether the driver of the following vehicle believes that the host vehicle will not turn right or left at the intersection.

[0005] Conventional driving control devices, such as the one described in Japanese Patent No. 6881323, do not consider deceleration control for vehicles traveling on a road with two separate intersections. If a vehicle traveling on a road with two intersections has not yet passed the first intersection, deceleration control cannot be used for the second intersection. Consequently, depending on the distance between the two intersections, deceleration at the second intersection may be delayed. Summary of the Invention

[0006] The present invention provides a driving control device and method that are improved in a manner that reduces the risk of deceleration delay due to deceleration control at the second intersection compared to the past when a vehicle is traveling on a road having two intersections separated from each other.

[0007] According to the present invention, a vehicle driving control device (100) is provided, wherein the vehicle includes: a deceleration device (brake control device 36) for decelerating the vehicle (102); an intersection detection device (navigation device 80) for detecting an intersection in front of the vehicle; and a control unit (driving assistance ECU 10) configured to execute deceleration control (S40, S90) for automatically decelerating the vehicle by the deceleration device when the vehicle is about to reach the intersection detected by the intersection detection device.

[0008] The control unit (driving assistance ECU 10) is configured to: when an intersection detection device (navigation device 80) detects a first intersection and a second intersection (IN1, IN2) (S10, S20) located on a driving road (110) on which the vehicle is traveling and separated from each other within a reference distance from the vehicle (102), and the first intersection (IN1) is closer to the vehicle than the second intersection (IN2), determine that a deceleration permission condition is met (S60) when it is inferred that the vehicle passes through the first intersection along the driving road (S30) and the time (T1) required for the vehicle to reach the first intersection is less than a first reference value (T1c), and further, when it is determined that the deceleration permission condition is met, when it is determined that the time (T2) required for the vehicle to reach the second intersection is less than a second reference value (T2c), start deceleration control (S90) when it is determined that the deceleration permission condition is met.

[0009] In addition, according to the present invention, a vehicle driving control method is provided, which includes the steps of detecting an intersection in front of a vehicle (102) (S10, S20), and executing a deceleration control step (S40, S90) of automatically decelerating the vehicle by a deceleration device when the vehicle is about to reach the detected intersection.

[0010] The driving control method further includes: a step (S60) of determining that a deceleration permission condition is satisfied when it is inferred that the vehicle passes through the first intersection (S30) along the driving road and the time (T1) required for the vehicle to reach the first intersection is less than a first reference value (T1c) when a first intersection and a second intersection (IN1, IN2) (S10, S20) are detected to be located on the driving road (110) on which the vehicle is traveling and are separated from each other within a reference distance from the vehicle (102), and the first intersection (IN1) is closer to the vehicle than the second intersection (IN2); and a step (S90) of starting deceleration control when it is determined that the time (T2) required for the vehicle to reach the second intersection is less than a second reference value (T2c) when it is determined that the deceleration permission condition is satisfied.

[0011] According to the aforementioned driving control device and method, when it is estimated that the vehicle is passing through a first intersection along the driving road and the time required for the vehicle to reach the first intersection is estimated to be less than a first reference value, it is determined that the deceleration permission condition is satisfied. Therefore, it is possible to determine whether the deceleration permission condition is satisfied before the vehicle reaches the first intersection.

[0012] Furthermore, if the deceleration permission condition is determined to be satisfied, deceleration control is initiated when it is determined that the estimated time required for the vehicle to reach the second intersection is less than a second reference value. Thus, compared to conventional driving control devices that cannot decelerate at the second intersection using deceleration control unless the vehicle has passed the first intersection, the possibility of a delay in deceleration at the second intersection using deceleration control can be reduced.

[0013] In one embodiment of the present invention, the control unit (driving assistance ECU 10) is configured to start deceleration control (S90) when it is determined that the deceleration permission condition is met and it is inferred that the vehicle (102) will not pass through the second intersection (IN2) along the driving road (110) (S70), and it is determined that the time (T2) required for the vehicle to reach the second intersection is less than a second reference value (T2c) (S80).

[0014] In another embodiment of the present invention, the control unit (driving assistance ECU 10) is configured to infer that the vehicle will pass through the first intersection along the driving road (S30) when it is determined that the driver has no intention of changing the vehicle's route in such a manner as to deviate from the driving road (110) at the first intersection (IN1).

[0015] In another embodiment of the present invention, the control unit (driving assistance ECU 10 ) is configured to obtain information on the vehicle speed (Vp) and calculate the first reference value ( T1c ) as a value obtained by dividing the vehicle speed by a preset constant (Gb) ( S50 ).

[0016] In this application, an "intersection" is a point where two or more roads intersect, specifically a crossroads, a T-junction, a Y-junction (branching point, confluence), or a point where three or more roads intersect. A "travel road" is a road where the vehicle is traveling.

[0017] In the above description, to facilitate understanding of the present invention, the names and / or reference numerals used in the embodiments described below are enclosed in parentheses for components of the invention corresponding to the embodiments described below. However, the components of the present invention are not limited to the components of the embodiments corresponding to the names and / or reference numerals enclosed in parentheses. Other objects, other features, and accompanying advantages of the present invention will be readily understood from the description of the embodiments of the present invention described with reference to the following drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention are described below with reference to the accompanying drawings, in which like reference numerals represent like elements, wherein:

[0019] Figure 1It is a schematic configuration diagram showing an embodiment of a vehicle travel control device according to the present invention.

[0020] Figure 2 This is a flowchart corresponding to the travel control program in the embodiment.

[0021] Figure 3 This diagram shows a case where the roads intersecting the travel road at the first intersection and the second intersection are a non-main road and a main road, respectively, and the vehicle does not turn left or right at the first intersection.

[0022] Figure 4 This diagram shows a situation where the roads intersecting the travel road at the first intersection and the second intersection are a non-main road and a main road, respectively, and the vehicle turns left or right at the first intersection.

[0023] Figure 5 This diagram shows a case where the roads intersecting the travel road at the first intersection and the second intersection are a main road and a non-main road, respectively, and the vehicle does not turn left or right at the first intersection.

[0024] Figure 6 This diagram shows a case where the roads intersecting the travel road at the first intersection and the second intersection are non-main roads, and the vehicle does not turn left or right at the first intersection and the second intersection. DETAILED DESCRIPTION

[0025] Hereinafter, a travel control device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0026] like Figure 1 As shown, a driving control device 100 according to an embodiment of the present invention is applied to a vehicle 102 and includes a driving assistance ECU 10. Vehicle 102 is capable of autonomous driving and includes a drive ECU 20, a brake ECU 30, an EPS / ECU 40, and an instrument ECU 50. An ECU is an electronic control unit (ECU) having a microcomputer as its main component.

[0027] Each ECU's microcomputer includes a CPU, ROM, RAM, read / write nonvolatile memory (N / M), and interfaces (I / F). The CPU implements various functions by executing instructions (programs, routines) stored in the ROM. Furthermore, these ECUs are interconnected to enable data exchange (communication) via CAN (Controller Area Network) 104. Therefore, detection values ​​from sensors (including switches) connected to a specific ECU are also transmitted to other ECUs.

[0028] The driving assistance ECU 10 is a central control device that performs driving assistance controls, including driving control with automatic deceleration, following distance control, and lane keeping control. In the embodiment, as described in detail below, the driving assistance ECU 10 cooperates with other ECUs to execute driving control for the vehicle 102. In the embodiment, the driving assistance ECU 10 executes driving control, including deceleration control that automatically reduces the vehicle speed when the vehicle reaches an intersection ahead.

[0029] The driving support ECU 10 is connected to a camera sensor 12, a radar sensor 14, and a setting operator 16. 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 landmark information acquisition device 18 that acquires landmark information around the vehicle 102.

[0030] Although not shown, the camera devices of the camera sensor 12 include a camera unit that captures images of the surroundings of the vehicle 102 and a recognition unit that analyzes image data captured by the camera unit to identify objects such as white road lines and other vehicles. The recognition unit provides information about the recognized objects to the driving support ECU 10 at predetermined intervals.

[0031] Each radar device in the radar sensor 14 uses radio waves in the millimeter wave band to detect the distance between the vehicle and a solid object, the relative speed between the vehicle and the solid object, and the relative position (or direction) of the solid object relative to the vehicle. The radar sensor 14 then supplies this information to the driving assistance ECU 10 at predetermined intervals. Alternatively, a laser radar (LiDAR) may be used in place of or in addition to the radar sensor 14.

[0032] The setting operator 16 is provided as in Figure 1 The position of the operator 16 can be set by the driver, as in the case of a steering wheel not shown in FIG. Figure 1 Although not shown in the figure, the setting operator 16 includes a driving assist switch. As will be described in detail later, when the driving assist switch is turned on, the driving assist ECU 10 performs travel control.

[0033] The drive ECU 20 is connected to a drive device 22 that applies driving force to drive wheels 24 to accelerate the vehicle 102. The drive ECU 20 normally controls the drive device 22 so that the driving force generated by the drive device 22 varies in response to a driver's driving operation. Upon receiving a command signal from the driving assistance ECU 10, the drive device 22 is controlled based on the command signal. Thus, the drive ECU 20 and the drive device 22 operate in conjunction with each other to function as a drive control device 26.

[0034] The brake ECU 30 is connected to a brake device 32 that applies braking force to wheels 34 to decelerate the vehicle 102. Normally, the brake ECU 30 controls the brake device 32 so that the braking force generated by the brake device 32 varies in response to a driver's braking operation. Upon receiving a command signal from the driving assistance ECU 10, the brake ECU 30 controls the brake device 32 based on the command signal, thereby performing automatic braking.

[0035] Therefore, the brake ECU 30 and the brake device 32 cooperate with each other to function as a brake control device 36. The brake control device 36 cooperates with the drive control device 26 to function as a deceleration device for decelerating the vehicle 102. When a braking force is applied to the wheels by driving control, etc., Figure 1 The brake lights (not shown) are illuminated.

[0036] 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 and vehicle speed in a manner known in the art to control the steering assist torque, thereby reducing the driver's steering burden. Furthermore, by controlling the EPS device 42, the EPS / ECU 40 can steer the steering wheel 44 as needed.

[0037] Connected to the instrument ECU 50 is a touch-panel display 52 that displays information such as the status of control performed by the driving support ECU 10. The display 52 may be, for example, an instrument cluster, a multi-information display that displays various types of information, or the display of the navigation system 80 described later. As will be described later, the display 52 displays the status of driving control upon receiving a signal from the driving support ECU 10.

[0038] The driving operation sensor 60 and the vehicle state sensor 70 are also connected to the CAN 104. Information detected by the driving operation sensor 60 and the vehicle state sensor 70 (referred to as sensor information) is transmitted to the CAN 104. The sensor information transmitted to the CAN 104 can be appropriately utilized by each ECU. Alternatively, the sensor information may be information from a sensor connected to a specific ECU, and transmitted from that specific ECU to the CAN 104.

[0039] The driving operation sensor 60 includes a driving operation amount sensor that detects the amount of accelerator pedal operation, a braking operation amount sensor that detects master cylinder pressure or brake pedal force, and a brake switch that detects whether the brake pedal is being operated. Furthermore, the driving operation sensor 60 includes a steering angle sensor that detects the steering angle, a steering torque sensor that detects the steering torque, and a turn signal switch that indicates whether a turn signal lever has been operated and the direction of the operation.

[0040] The vehicle state sensor 70 includes a vehicle speed sensor for detecting the vehicle speed V of the vehicle 102 , a longitudinal acceleration sensor for detecting the vehicle's longitudinal acceleration, a lateral acceleration sensor for detecting the vehicle's lateral acceleration, and a yaw rate sensor for detecting the vehicle's yaw rate.

[0041] Furthermore, the navigation device 80 is also connected to the CAN 104. The navigation device 80 includes a GPS receiver for detecting the location of the vehicle 102, a storage device for storing map information and road information, and a communication device for externally acquiring the latest map and road information. In particular, the road information includes information about intersections and whether a road is a major road. The navigation device 80 functions as an intersection detection device that detects intersections ahead of the vehicle.

[0042] In the embodiment, the ROM of the driving assistance ECU 10 stores Figure 2 The driving control program corresponding to the flowchart shown in FIG. Figure 2 The flowchart shown executes the travel control to perform the travel control method according to the embodiment.

[0043] <Driving Control( Figure 2 )>

[0044] Next, refer to Figure 2 The flowchart shown in FIG. 1 illustrates the driving control in the embodiment. When the driving assist switch is turned on, the CPU of the driving assist ECU 10 repeatedly executes the following at predetermined intervals: Figure 2 The flowchart shown relates to driving control. When the driver performs a brake operation during driving control, driving control is terminated so that deceleration related to the brake operation takes priority over deceleration related to driving control, and vehicle deceleration depends on the driver's brake operation.

[0045] First, in step S10, the CPU determines whether the navigation device 80, functioning as an intersection detection device, has detected a first (first) intersection located ahead of the vehicle 102 on the road on which the vehicle is traveling, within a range of a first reference distance L1r (a positive constant) from the vehicle 102. If a negative determination is made, this control is temporarily terminated. If a positive determination is made, this control proceeds to step S20.

[0046] In step S20, the CPU determines whether the navigation device 80 has detected a second (second) intersection located ahead of the vehicle 102 on the travel path and separated from the first intersection forward within a range of a second reference distance L2r (a positive constant greater than the first distance L1r) from the vehicle 102. If a negative determination is made, the control proceeds to step S40. If an affirmative determination is made, the control proceeds to step S30.

[0047] In step S30, the CPU determines whether it is estimated that the vehicle 102 will pass through the first intersection along the travel road. If the determination is affirmative, the control proceeds to step S50, and if the determination is negative, the control proceeds to step S40.

[0048] In step S30, when (1) the turn signal switch is in the right turn position or the left turn position, or (2) the vehicle is in the right turn lane or the left turn lane, that is, when it is inferred that the driver has the intention to change the vehicle's route by leaving the driving road, a negative judgment is made. Among them, the above (2) can be judged based on the object information obtained by the object information acquisition device 18. In addition, when (3) the traffic light on the driving road side of the first intersection is red or yellow, a negative judgment is also made. In contrast, when any of the above conditions (1) to (3) is not met, a positive judgment can be made, especially when any of the above conditions (1) to (3) is not met and the road intersecting the driving road at the first intersection is not a main road, a positive judgment can be made.

[0049] In step S40, the CPU obtains information about the distance L1 from the current location of the vehicle 102 to the first intersection based on information from the navigation device 80 or information obtained by the landmark information acquisition device 18. The CPU then sets a target deceleration pattern based on the current speed Vp of the vehicle 102, the target speed V1t when the vehicle 102 reaches the first intersection, and the distance L1, as is known in the art. The CPU then controls the brake control device 36 according to the target deceleration pattern, thereby executing deceleration control to decelerate the vehicle at the first intersection. Consequently, the deceleration control controls the speed V of the vehicle 102 so that the speed at the time of arrival at the first intersection is the target speed V1t. The target speed V1t can be a preset constant, but can also be variably set based on the type of the first intersection, the status of the traffic light, and other factors, and can be zero when the traffic light is red or yellow.

[0050] For example, when the intersection is a T-junction and the traveling road is a road that abuts a straight road, or when the intersection is a merging point and the traveling road is a road that merges with a main road, the target vehicle speed V1t can be a lower value than when the intersection is a crossroads.

[0051] In step S50, the CPU calculates and estimates the time T1 required for the vehicle to reach the first intersection based on the distance L1 from the current location of vehicle 102 to the first intersection and the vehicle's current speed Vp. The CPU then determines whether time T1 is less than a first reference time T1c. If a negative determination is made, control returns to step S30. If a positive determination is made, control proceeds to step S60.

[0052] The first reference value time T1c may be a positive constant set as the time that a driver with average driving skills continues to decelerate the vehicle before an intersection. However, in the embodiment, the deceleration rate when a driver with average driving skills decelerates the vehicle before an intersection is set to Gb [m / sec 2 ], the current vehicle speed is set to Vp [m / sec], and the first reference value time T1c is calculated as Vp / Gb.

[0053] In step S60 , the CPU determines that the deceleration permission condition is satisfied because it estimates that the vehicle passes the first intersection along the travel road and determines that the estimated time T1 required for the vehicle to reach the first intersection is less than the first reference value T1 c.

[0054] In step S70, the CPU determines whether it is estimated that the vehicle 102 has passed the second intersection along the travel route, similarly to step S30. If an affirmative determination is made, the present control is temporarily terminated, and if a negative determination is made, the present control proceeds to step S80.

[0055] In step S70, a negative determination is also made when (1) the turn signal switch is in the right turn position or the left turn position, or (2) the vehicle 102 is in the right turn lane or the left turn lane. In addition, a negative determination is also made when (3) the traffic light on the driving road side of the second intersection is red or yellow. In contrast, a positive determination can be made when none of the above conditions (1) to (3) are met, and in particular, a positive determination can be made when none of the above conditions (1) to (3) are met and the road intersecting the driving road at the second intersection is not a main road.

[0056] In step S80, the CPU obtains information about the distance L2 from the current location of the vehicle 102 to the second intersection based on information from the navigation device 80 or information obtained by the object marker information acquisition device 18. Furthermore, the CPU calculates the estimated time T2 required for the vehicle to reach the second intersection based on the distance L2 from the current location of the vehicle 102 to the second intersection and the vehicle's current speed Vp. The CPU then determines whether time T2 is less than a second reference time T2c. If a negative determination is made, control returns to step S70. If a positive determination is made, control proceeds to step S90.

[0057] The second reference time T2c, like the first reference time T1c, can be a positive constant set as the time a driver with average driving skills continues to decelerate the vehicle just before the intersection, and is calculated as Vp / Gb.

[0058] In step S90, the CPU obtains information about the distance L2 from the current location of the vehicle 102 to the second intersection based on information from the navigation device 80 or information obtained by the landmark information acquisition device 18. The CPU then sets a target deceleration pattern based on the current vehicle speed Vp of the vehicle 102, the target vehicle speed V2t, and the distance L2, as is known in the art, and controls the brake control device 36 according to the target deceleration pattern, thereby executing deceleration control to decelerate the vehicle at the second intersection. Target vehicle speed V2t can be a preset constant, similar to target vehicle speed V1t, but can also be variably set based on the type of the second intersection, traffic light status, and the like, and can be set to zero when the traffic light is red or yellow.

[0059] In step S100, the CPU determines whether the vehicle speed of the vehicle 102 has decreased to or below the target vehicle speed V2t. If a negative determination is made, the control returns to step S90, and if an affirmative determination is made, the control proceeds to step S110.

[0060] In step S110, the CPU terminates the deceleration control and temporarily terminates the present control by outputting a deceleration control termination command signal to the brake control device 36. Therefore, the vehicle speed V of the vehicle 102 when it arrives at the second intersection is controlled to be equal to or lower than the target vehicle speed V2t.

[0061] <Implementation Plan>

[0062] Next, refer to Figures 3 to 6 , the operation of the implementation method is described for various situations where the first intersection and the second intersection are different in type. Figures 3 to 6 As shown, a vehicle 102 is traveling on a driving road 110, and there are a first intersection IN1 and a second intersection IN2 separated from each other on the driving road. The first intersection IN1 and the second intersection IN2 are located within a range of a first reference distance L1r (positive constant) and a second reference distance L2r from the vehicle 102, respectively. The first intersection is closer to the vehicle than the second intersection. Figures 3 to 6 In the diagram, the first intersection IN1 and the second intersection IN2 are crossroads, but may be intersections other than crossroads such as a T-junction or a Y-junction.

[0063] <C1: The roads intersecting the travel road at the first intersection and the second intersection are respectively a non-main road and a main road, and the vehicle does not turn left or right at the first intersection ( Figure 3 )>

[0064] The road 112 intersecting the travel road 110 at the first intersection IN1 is a non-main road, and the road 114 intersecting the travel road 110 at the second intersection IN2 is a main road. It is estimated that the vehicle 102 passes through the first intersection IN1 without turning left or right.

[0065] If affirmative determinations are made in steps S10 and S20 and none of the conditions (1) to (3) above are met, an affirmative determination is made in step S30. As vehicle 102 approaches first intersection IN1 as indicated by the dotted line, if it is determined that the estimated time T1 required for the vehicle to reach the first intersection is less than first reference time T1c, an affirmative determination is made in step S50. Therefore, before vehicle 102 passes first intersection IN1, the deceleration permission condition is determined to be met.

[0066] If at least one of the above conditions (1) to (3) is met while the deceleration permission conditions are met, a negative determination is made in step S70. As the vehicle 102 continues to travel and approaches the second intersection IN2 as indicated by the dashed line, if it is determined that the estimated time T2 required for the vehicle to reach the second intersection is less than the second reference time T2c, a positive determination is made in step S80. Consequently, the deceleration control of steps S90 to S110 is executed, and the vehicle speed V of the vehicle 102 upon reaching the second intersection IN2 is controlled to be less than or equal to the target vehicle speed V2t.

[0067] Among them, Figure 3 In the case where the road intersecting the second intersection IN2 is a main road, if the road intersecting the second intersection IN2 is a non-main road, a negative determination is also made in step S70 if at least one of the above conditions (1) to (3) is satisfied. Furthermore, if none of the above conditions (1) to (3) is satisfied and a positive determination is made in step S70, steps S90 to S110 are not executed, and thus deceleration control is not executed.

[0068] <C2: The roads intersecting the travel road at the first intersection and the second intersection are respectively a non-main road and a main road, and the vehicle turns left or right at the first intersection ( Figure 4 )>

[0069] As in the case of C1, the road 112 intersecting the driving road 110 at the first intersection IN1 is a non-main road, and the road 114 intersecting the driving road 110 at the second intersection IN2 is a main road. However, it is estimated that the vehicle 102 turns right or left at the first intersection IN1.

[0070] Affirmative determinations are made in steps S10 and S20, but a negative determination is made in step S30. Therefore, in step S40, deceleration control is executed to decelerate the vehicle 102 at the first intersection IN1, and the vehicle speed V is controlled so that the vehicle speed reaches the target vehicle speed V1t when the vehicle arrives at the first intersection.

[0071] <C3: The roads intersecting the travel road at the first intersection and the second intersection are respectively a main road and a non-main road, and the vehicle does not turn left or right at the first intersection ( Figure 5 )>

[0072] The road 112 intersecting the travel road 110 at the first intersection IN1 is a main road, and the road 114 intersecting the travel road 110 at the second intersection IN2 is a non-main road. It is estimated that the vehicle 102 passes through the first intersection IN1 without turning left or right.

[0073] As in the case of C1, if affirmative determinations are made in steps S10 and S20 and none of the conditions (1) to (3) are satisfied, an affirmative determination is made in step S30. Therefore, before the vehicle 102 passes the first intersection IN1, it is determined that the deceleration permission condition is satisfied.

[0074] If at least one of the above conditions (1) to (3) is met while the deceleration permission conditions are met, a negative determination is made in step S70. Therefore, by executing the deceleration control in steps S90 to S110, the vehicle speed V of the vehicle 102 when it arrives at the second intersection IN2 is controlled to be equal to or less than the target vehicle speed V2t.

[0075] Among them, Figure 5 In the case where the road intersecting the second intersection IN2 is a non-main road, but the road intersecting the second intersection IN2 is a main road, if at least one of the above conditions (1) to (3) is satisfied, a negative determination is also made in step S70. Furthermore, if none of the above conditions (1) to (3) is satisfied and a positive determination is made in step S70, steps S90 to S110 are not executed, and thus deceleration control is not executed.

[0076] <C4: The road that intersects the traveling road at the first intersection and the second intersection is a non-main road, and the vehicle does not turn left or right at the first intersection and the second intersection ( Figure 6 )>

[0077] Roads 112 and 114 intersecting the travel road 110 at the first intersection IN1 and the second intersection IN2 are non-main roads. It is estimated that the vehicle 102 passes through the first intersection IN1 and the second intersection IN2 without turning left or right.

[0078] If affirmative determinations are made in steps S10 and S20 and none of the conditions (1) to (3) above are met, it is inferred that the vehicle has passed through the first and second intersections, and affirmative determinations are made in steps S30 and S70. Since steps S40 and S90 to S110 are not executed, deceleration control is not executed.

[0079] If any of the conditions (1) to (3) above are met while the vehicle 102 is approaching the first intersection, and a negative determination is made in step S30, step S40 is executed. Thus, as in the case of C2 above, deceleration control is executed to decelerate the vehicle 102 at the first intersection IN1, and the vehicle speed V is controlled so that the vehicle speed at the time of arrival at the first intersection becomes the target vehicle speed V1t.

[0080] If, after affirmative determinations in steps S30 and S50, none of the conditions (1) to (3) above are satisfied, and a negative determination is made in step S70, step S80 is executed. Furthermore, if an affirmative determination is made in step S80, deceleration control in steps S90 to S110 is executed. Thus, similar to the case of C1 above, the vehicle speed V of the vehicle 102 upon reaching the second intersection IN2 is controlled to be equal to or less than the target vehicle speed V2t.

[0081] As can be seen from the above description, according to the present invention, when it is estimated that the vehicle 102 is passing through the first intersection IN1 along the travel road 110 (S30), and the time T1 required for the vehicle to reach the first intersection is estimated to be less than the first reference value T1c (S50), it is determined that the deceleration permission condition is met (S60). Therefore, it is possible to determine whether the deceleration permission condition is met before the vehicle reaches the first intersection.

[0082] Furthermore, if it is determined that the deceleration permission condition is met and it is determined that the estimated time T2 required for the vehicle to reach the second intersection IN2 is less than the second reference value T2c (S80), deceleration control is initiated (S90). Thus, compared to conventional driving control devices that cannot decelerate at the second intersection using deceleration control unless the vehicle has passed the first intersection, the risk of a deceleration delay at the second intersection using deceleration control can be reduced.

[0083] Furthermore, according to the present invention, when it is estimated that the vehicle 102 will not pass through the second intersection IN2 along the travel road 110 (S70), and it is determined that the time T2 estimated to be required for the vehicle to reach the second intersection is less than the second reference value T2c (S80), deceleration control is initiated (S90). Therefore, compared to a case where the estimation that the vehicle will not pass through the second intersection along the travel road is not used as a condition for initiating deceleration control, the possibility of unnecessary execution of deceleration control can be reduced.

[0084] Furthermore, according to the present invention, when it is determined that the driver has no intention to change the vehicle's route so as to depart from the driving road 110 at the first intersection IN1, it is inferred that the vehicle is passing the first intersection along the driving road (S30). Therefore, by determining whether the driver has any intention to change the vehicle's route so as to depart from the driving road at the first intersection, it is possible to infer whether the vehicle is passing the first intersection along the driving road.

[0085] Furthermore, according to the present invention, first reference value T1c is calculated as the value obtained by dividing vehicle speed V by a predetermined constant (S50). Therefore, the first reference value is variably set according to vehicle speed, increasing with increasing vehicle speed. Consequently, compared to a case where the first reference value is constant regardless of vehicle speed, the timing for starting deceleration control can be more appropriately determined.

[0086] In particular, according to the embodiment, the preset constant is the deceleration Gb when a driver with average driving skills decelerates the vehicle just before an intersection. Therefore, the first reference value can be set to the time that a driver with average driving skills continues to decelerate the vehicle just before an intersection.

[0087] While specific embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and it is apparent to those skilled in the art that various other embodiments can be implemented within the scope of the present invention.

[0088] For example, in the above embodiment, the first reference distance L1r used in step S10 and the second reference distance L2r used in step S20 are positive constants. However, the reference distances L1r and L2r may be variably set according to the vehicle speed, for example, so that they increase as the vehicle speed V increases.

[0089] In the above-described embodiment, in steps S30 and S70, if none of the conditions (1) to (3) above are met, a positive determination is made, indicating that the vehicle has passed through the first intersection and the second intersection, respectively. However, any of the conditions (1) to (3) above may be omitted. Furthermore, the determination of whether the road intersecting the travel road at the intersection is a main road may be omitted.

[0090] In the above-described embodiment, deceleration control is executed in steps S40 and S90 to decelerate the vehicle 102 according to a target deceleration pattern set based on the current vehicle speed Vp, target vehicle speeds V1t and V2t, and distances L1 and L2. However, deceleration control to decelerate the vehicle at the first or second intersection does not constitute the gist of the present invention and may be performed using any method known in the art.

[0091] Furthermore, in the above-described embodiment, a positive determination is made in step S20 if a second intersection is detected that is located ahead of the vehicle 102 on the travel path and separated forward from the first intersection within a second reference distance from the vehicle 102. That is, the distance between the first and second intersections is arbitrary. However, a negative determination may be made in step S20 if the distance between the first and second intersections is greater than a reference distance. In this case, the reference distance may be variably set according to vehicle speed, for example, such that it increases as vehicle speed V increases.

Claims

1. A driving control device for a vehicle, the vehicle comprising: a deceleration device to slow down the vehicle; an intersection detection device for detecting an intersection in front of the vehicle; and a control unit configured to execute deceleration control for automatically decelerating the vehicle by the deceleration device when the vehicle is about to arrive at the intersection detected by the intersection detection device, wherein The control unit is configured to: when the intersection detection device detects a first intersection and a second intersection separated from each other and located on the driving road in which the vehicle is traveling within a range of a reference distance from the vehicle, and the first intersection is closer to the vehicle than the second intersection, when it is inferred that the vehicle will pass through the first intersection along the driving road and it is inferred that the time required for the vehicle to reach the first intersection is less than a first reference value, determine that the deceleration permission condition is met; and further configured to: when it is determined that the deceleration permission condition is met, when it is determined that the time required for the vehicle to reach the second intersection is less than a second reference value, start the deceleration control.

2. The vehicle travel control device according to claim 1, wherein: The control unit is configured to start the deceleration control when it is determined that the deceleration permission condition is met, when it is inferred that the vehicle does not pass the second intersection along the driving road, and when it is determined that the time required for the vehicle to reach the second intersection is less than a second reference value.

3. The vehicle travel control device according to claim 1, wherein: The control unit is configured to infer that the vehicle will pass through the first intersection along the traveling road when it is determined that the driver has no intention of changing the vehicle's course so as to exit the traveling road at the first intersection.

4. The vehicle travel control device according to claim 1, wherein: The control unit is configured to obtain information on a vehicle speed and calculate the first reference value as a value obtained by dividing the vehicle speed by a preset constant.

5. A method for controlling a vehicle's travel, comprising the steps of detecting an intersection ahead of the vehicle, and executing a deceleration control step of automatically decelerating the vehicle by a deceleration device when the vehicle is about to reach the detected intersection, wherein: The driving control method also includes: a step of determining that a deceleration permission condition is met when it is inferred that the vehicle will pass through the first intersection along the driving road and the time required for the vehicle to reach the first intersection is less than a first reference value, when a first intersection and a second intersection separated from each other are detected and located on the driving road in which the vehicle is traveling within a reference distance from the vehicle, and the first intersection is closer to the vehicle than the second intersection; and a step of starting the deceleration control when it is determined that the time required for the vehicle to reach the second intersection is less than a second reference value, when the deceleration permission condition is determined to be met.

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