Deceleration support device of vehicle

Abstract

To provide a deceleration support device of a vehicle in which: in a case that a preceding vehicle exists ahead of a position where an own vehicle travels on a lane for right turn or left turn arranged through widening a road or on an added lane in front of the own vehicle, a deceleration support is started in the presence of the preceding vehicle before the own vehicle recognizes the added lane in front of the own vehicle as an adjacent lane.SOLUTION: A deceleration support device 50 of a vehicle comprises: preceding vehicle determination means which determines whether a preceding vehicle vf exists in a prescribed range AL in front of the own vehicle out of an own vehicle lane OL where the own vehicle vo travels; and deceleration control means which decelerates the own vehicle in the presence of the preceding vehicle while satisfying a prescribed condition.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a driving support device for vehicles such as automobiles, and more particularly to a device that executes deceleration support when a preceding vehicle exists in an additional lane in a scene where a road is widened.

Background Art

[0002] As one of vehicle driving supports, a system has been proposed that executes deceleration operations and control of the inter-vehicle distance in various manners in a situation where a preceding vehicle is traveling in an adjacent lane adjacent to the own lane in which the own vehicle is traveling. For example, in Patent Document 1, it has been proposed to perform control to ensure the inter-vehicle distance between the preceding vehicle and the own vehicle when the lateral position of the preceding vehicle traveling in the adjacent lane reaches a reference lateral position. Further, in Patent Document 2, when the turn signal of the own vehicle is blinking and the amount of intrusion of the own vehicle into the adjacent lane exceeds a threshold value, it is determined that the own vehicle changes lanes, and another vehicle traveling in the adjacent lane is set as the preceding vehicle, and driving support control (engine control and brake control) is performed to maintain the inter-vehicle distance.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Incidentally, when deceleration assistance is executed in a situation where a preceding vehicle exists in an adjacent lane adjacent to the lane in which the own vehicle is traveling, such assistance is generally started under the establishment of a predetermined condition that is appropriately set when the own lane and the adjacent lane are detected and the presence of the preceding vehicle is confirmed in the detected adjacent lane. In such a configuration, when the road is widened ahead of the position of the own vehicle during travel and a right-turn or left-turn lane is provided, or when the number of lanes is increased, the right-turn or left-turn lane or the added lane (hereinafter generally referred to as the "ahead added lane") will not be detected as an adjacent lane until the own vehicle reaches near it and enters the recognition range of the adjacent lane of the own vehicle. Therefore, even if a preceding vehicle in the ahead added lane is detected, until the own vehicle reaches near the added lane and detects the added lane as an adjacent lane, it is not recognized that there is a preceding vehicle in the adjacent lane, and accordingly, the start of deceleration assistance will be delayed compared to the case where an adjacent lane exists (deceleration assistance can be executed after the own vehicle starts to drive parallel to the ahead added lane or after changing lanes and getting behind the preceding vehicle). Therefore, when there is a preceding vehicle in the ahead added lane, if deceleration assistance in the presence of the preceding vehicle is started even before the ahead added lane is recognized as an adjacent lane by the own vehicle, the assistance can be executed promptly and its effect can be made more effective.

[0005] In view of the above circumstances, the main problem of the present invention is to start deceleration assistance in the presence of a preceding vehicle in the own vehicle before the ahead added lane provided by widening the road ahead of the position of the own vehicle during travel is recognized as an adjacent lane.

Means for Solving the Problem

[0006] According to the present invention, the above problem is solved by a deceleration assistance device for a vehicle, a preceding vehicle determination means for determining whether a preceding vehicle exists within a predetermined range in front of the own vehicle outside the own lane during travel of the own vehicle, a deceleration control means for decelerating the own vehicle under the establishment of a predetermined condition when the preceding vehicle exists, and is achieved by a device including the above.

[0007] In the above configuration, the recognition of the own lane during the running of the own vehicle and the recognition of the preceding vehicle existing within a predetermined range in front of the own vehicle outside the own lane can be executed using any peripheral recognition means such as an in-vehicle camera or a millimeter-wave radar. The "predetermined range in front of the own vehicle" is a range in which it is considered better to decelerate the own vehicle when the preceding vehicle exists within that range, and specifically, it may be set by any method based on the relative position or further relative speed with the preceding vehicle. The detection of the relative position and relative speed with the preceding vehicle can also be executed using any peripheral recognition means as described above.

[0008] Also, in the "deceleration control means", the "predetermined conditions" that should be established to execute the deceleration of the own vehicle when the preceding vehicle exists are, if necessary, conditions under which it is determined that the driver of the own vehicle intends to follow behind the detected preceding vehicle by changing the lane of the own vehicle, and may be appropriately set in any manner. Specifically, for example, in one aspect, when the direction indicator is operated in the direction of the preceding vehicle and the depression of the accelerator pedal is released and it is determined that the driver does not intend to accelerate or intends to decelerate, it may be determined that the above predetermined conditions are satisfied. Alternatively, in another aspect, in addition to the operation of the direction indicator in the direction of the preceding vehicle and the release of the depression of the accelerator pedal, it may be further added as a condition that there is sufficient margin for the own vehicle to enter behind the preceding vehicle (this condition is added because usually, the own vehicle does not execute a lane change when the own vehicle is approaching the preceding vehicle so much that there is no margin for the own vehicle to enter behind the preceding vehicle). Whether there is sufficient margin for the own vehicle to enter behind the preceding vehicle may be determined by whether the relative distance in the traveling direction between the preceding vehicle and the own vehicle, or the collision prediction time (TTC - Time To Collision) calculated from the relative distance and relative speed, is equal to or greater than a predetermined value appropriately set.

[0009] In the deceleration control implemented in the above-described device of the present invention, since the control start is relatively early, the magnitude of the deceleration to be executed may be relatively small, and it may be set to a level that does not give the driver a sense of discomfort and gives a sense of security. The specific magnitude of the deceleration may be set by adaptation.

[0010] The deceleration control by the above-described device of the present invention may be released when the host vehicle changes lanes after the start. After the lane change, driving support may be executed when there is a preceding vehicle on the host lane. Further, the deceleration control by the above-described device of the present invention may also be released when it is determined that there is not enough margin for the host vehicle to enter behind the preceding vehicle after the start. After the release, driving support in any mode may be executed.

Advantages of the Invention

[0011] Thus, according to the above-described present invention, when there is a preceding vehicle at a position corresponding to an additional lane ahead, if a condition is satisfied that the driver of the host vehicle intends to change the lane of the host vehicle and attach the host vehicle behind the detected preceding vehicle, the deceleration of the host vehicle is executed even if the adjacent lane is not detected. Therefore, it is expected that the deceleration support is executed more promptly and its effect becomes more effective. Further, according to the configuration of the present invention, the start of the deceleration support can be made before the lane change is started, and the start of the deceleration support at an early timing can be achieved, which is advantageous in that the effect of avoiding the execution of a sudden brake can also be obtained. The configuration of the present invention may be used in autonomous driving.

[0012] Other objects and advantages of the present invention will become apparent from the following description of the preferred embodiments of the present invention.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Description of Reference Numerals

[0014] 10…Vehicle, 12FL, FR, RL, RR…Wheels, 14…Accelerator pedal, 16…Direction indicator (winker), 40…Brake device, 42…Wheel cylinder, 44…Brake pedal, 45…Master cylinder, 46…Hydraulic circuit, 50…Electronic control device, 70…In-vehicle camera, 72…In-vehicle radar device

Best Mode for Carrying Out the Invention

[0015] Configuration of the vehicle Referring to FIG. 1(A), in a vehicle 10 such as an automobile in which a preferred embodiment of the deceleration assist device of the present embodiment is incorporated, in a normal mode, the left and right front wheels 12FL, 12FR, the left and right rear wheels 12RL, 12RR, a drive system device (not shown) that generates driving force for each wheel in response to the driver depressing the accelerator pedal 14, a steering device (not shown) for controlling the steering angle of the front wheels (or further the rear wheels), and a braking system device 40 that generates braking force for each wheel are mounted. The drive system device is configured such that, in a normal mode, driving torque or rotational force is transmitted from an engine and / or an electric motor (not shown; a hybrid drive device having both an engine and an electric motor may be used) to the front wheels 12FL, 12FR or the rear wheels 12RL, 12RR via a transmission and a differential gear device (not shown). As the steering device, a normal steering device that transmits the rotation of a steering wheel (not shown) operated by the driver to a tie rod and steers the front wheels 12FL, 10FR may be employed. Further, a direction indicator 16 may be provided in the vicinity of the steering wheel in a normal mode.

[0016] The braking system device 40 is an electronically controlled hydraulic braking device in which the braking pressure in the wheel cylinders 42i (i = FL, FR, RL, RR; the same applies hereinafter) equipped on each wheel, that is, the braking force on each wheel, is adjusted by a hydraulic circuit 46 communicating with a master cylinder 45 that is actuated in response to the depression of a brake pedal 44 by the driver. In the hydraulic circuit 46, various valves (master cylinder cut-off valve, hydraulic pressure holding valve, pressure reducing valve) that selectively communicate the wheel cylinders of each wheel with the master cylinder, an oil pump, or an oil reservoir (not shown) are provided in a normal mode. In normal operation, in response to the depression of the brake pedal 44, the pressure of the master cylinder 45 is supplied to the respective wheel cylinders 42i. In particular, in the present embodiment, as will be described in detail later, when the presence of a preceding vehicle is recognized at a position outside the own lane and the driver is determined to be trying to follow behind the preceding vehicle, as one of the driving supports, deceleration is automatically executed. In that case, the hydraulic circuit 46 may apply a braking pressure to the wheel cylinders 42i of each wheel based on a command from the electronic control device 60 so that braking force can be generated. Note that the braking system device 40 may be of a type that applies braking force to each wheel pneumatically or electromagnetically or any other type that is arbitrary for those skilled in the art. Also, the braking force by the deceleration support in the present embodiment may be applied by the regeneration of an electric motor when the drive system device has an electric motor.

[0017] Furthermore, in the vehicle 10 of the present embodiment, an in-vehicle camera 70, a radar device 72, etc. for detecting the situation around the vehicle are provided, and the vehicle is configured to be able to detect the vehicles existing around the vehicle 10 (own vehicle) and the own lane.

[0018] The operation control of each part of the vehicle and the operation control of the deceleration assistance device according to the present embodiment are executed by the electronic control unit 50. The electronic control unit 50 may be a normal type of computer device, and the configuration and operation of each part of the deceleration assistance device of the present embodiment described later may be realized by the operation of the electronic control unit (computer) 50 according to a program. Information from an in-vehicle camera 70, a radar device 72, etc., the depression amount θa of the accelerator pedal, the state θw of the turn indicator, the wheel speeds Vwi (i = FL, FR, RL, RR), etc., are input to the electronic control unit 50 as detection values from various sensors referred to as parameters for the deceleration assistance control of the present embodiment executed in the manner described later. As deceleration assistance, control commands representing control amounts in deceleration control are output to the corresponding devices. Note that various parameters necessary for various controls to be executed in the vehicle of the present embodiment, for example, various detection signals such as the wheel cylinder pressure Pbi, the yaw rate and / or lateral acceleration from a gyro sensor (not shown), the steering angle, the depression amount θb of the brake pedal, the detection values of the front and rear G sensors (not shown), etc., may be input, and various control commands may be output to the corresponding devices.

[0019] Configuration of the device Referring to FIG. 1(B), generally speaking, the deceleration assistance device according to this embodiment includes a surrounding recognition unit that recognizes a preceding vehicle existing outside the own lane in which the host vehicle (vehicle 10) is traveling, a deceleration assistance execution determination unit that determines whether deceleration assistance needs to be executed, and a deceleration control unit that controls the deceleration. The surrounding recognition unit recognizes the lane (own lane) in which the host vehicle is traveling and the adjacent lane (when it exists) in an arbitrary manner from information such as an image representing the situation around the vehicle, such as an in-vehicle camera 70 and a radar device 72, and is configured to recognize other vehicles (surrounding vehicles) existing around the host vehicle. For the surrounding vehicles existing ahead in the traveling direction of the vehicle, when the vehicle is on the own lane or is outside the own lane but at a position adjacent to the own lane, the relative distance, relative speed, etc. from the surrounding vehicle are detected, and further the TTC (= relative distance / relative speed) is calculated. When the TTC is less than a predetermined value set as appropriate or when the relative distance is less than a predetermined value set as appropriate, the surrounding vehicle is recognized as a preceding vehicle. Here, the "predetermined value set as appropriate" is a value at which it is considered that the host vehicle should decelerate when the TTC or the relative distance is less than the predetermined value, and it may be set by adaptation. The deceleration assistance execution determination unit refers to the information from the surrounding recognition unit (particularly, the information that there is a preceding vehicle at a position outside the own lane but adjacent to the own lane and its TTC, etc.), the state of the direction indicator 16, and the state of the accelerator pedal 14, and is configured to determine whether to execute deceleration assistance in the manner described below. Then, in response to the deceleration assistance execution determination unit determining to execute deceleration assistance, the deceleration control unit is configured to transmit a control command for generating a braking force to the braking device in a normal manner.

[0020] Operation of the device (1) Overview As described in the "Summary of the Invention" section, as schematically depicted in FIG. 2, when the road during the travel of the host vehicle vo is widened in front of the host vehicle vo and an additional lane (front additional lane) AL is added, at the current position of the host vehicle vo, there is no adjacent lane adjacent to the host lane OL, and the front additional lane AL is not recognized as an adjacent lane. In the conventional system, even if there is a preceding vehicle vf in the front additional lane AL, deceleration assistance for maintaining the inter-vehicle distance from the preceding vehicle vf was not executed. However, when there is a preceding vehicle vf in the front additional lane AL, if deceleration assistance for the host vehicle vo can be executed earlier, before the host vehicle vo reaches a position where it recognizes the front additional lane AL as an adjacent lane or before the host vehicle vo changes lanes and follows behind the preceding vehicle vf, it becomes possible to ensure a good inter-vehicle distance with the preceding vehicle vf with a margin, making the effect of deceleration assistance more effective, and reducing the need to execute sudden deceleration, thereby avoiding sudden braking. Thus, in the present embodiment, when it is recognized that there is a preceding vehicle at the position of the front additional lane AL that is not recognized as an adjacent lane, and it is detected that the driver intends to change the lane of the host vehicle and follow behind the preceding vehicle, deceleration assistance that automatically applies braking force to the host vehicle is executed.

[0021] FIG. 3 shows a time chart of the state of the host vehicle when deceleration assistance according to the present embodiment is implemented when the host vehicle changes lanes and follows behind the preceding vehicle in the case where there is a preceding vehicle in the front additional lane. As can be understood with reference to this figure, in the case of the present embodiment, in a situation where there is a preceding vehicle in the front additional lane, when the direction indicator is operated in the direction of the preceding vehicle before the host vehicle changes lanes, in response to this, as indicated by reference sign a, deceleration starts (in the conventional case, as indicated by reference sign b, deceleration starts after the lane change is completed, so the assistance is delayed accordingly).

[0022] In the deceleration assistance of the above-described present embodiment, as already mentioned, among the surrounding vehicles, a vehicle that has deviated from the own lane but is located adjacent to the own lane and has a TTC lower than a predetermined value (Tha), or a vehicle with a relative distance ΔL lower than a predetermined value (Thal) is recognized as a leading vehicle vf in the forward additional lane AL (see FIG. 2). In this regard, if there is no room for the host vehicle to follow behind the leading vehicle in the positional relationship between the leading vehicle and the host vehicle, that is, as shown in FIG. 4, when the host vehicle changes lanes (y) and cannot secure a sufficient inter-vehicle distance (X) when following behind the leading vehicle, the host vehicle usually does not execute a lane change to follow behind the leading vehicle. (In that situation, even if the driver indicates an intention to change lanes, it is considered that the driver is not trying to make the host vehicle follow behind the leading vehicle but rather trying to enter in front of the leading vehicle.) Therefore, in the present embodiment, as a condition for executing deceleration assistance, it may be added that there is room for the host vehicle to follow behind the leading vehicle. Specifically, when an intention to change lanes is detected while the leading vehicle satisfies TTC>Thb or ΔL>Thebl, deceleration assistance may be executed. That is, when a surrounding vehicle in the forward additional lane AL satisfies Tha>TTC>Thb or Thal>ΔL>Thebl, deceleration assistance according to the present embodiment can be executed.

[0023] (2) Processing procedure The deceleration assistance in the device according to this embodiment may be executed as shown in the flowchart of FIG. 5. Referring to the figure, first, surrounding vehicles are recognized (step 1), and there is a lead vehicle outside the own lane that satisfies Tha>TTC or Thal>ΔL at the position of the additional lane ahead (a lead vehicle that is outside the own lane but at a position adjacent to the own lane) (step 2). When there is no sense of approach between the lead vehicle outside the own lane and the own vehicle, that is, when the lead vehicle outside the own lane satisfies TTC>Thb or ΔL>Thebl and there is room for the own vehicle to follow behind the lead vehicle (step 3), the direction indicator of the own vehicle is operated in the direction of the lead vehicle (step 4). Further, when the depression of the accelerator pedal is released and it is confirmed that the driver has no intention of accelerating the own vehicle (step 5), regardless of whether the lane change of the own vehicle has started or not, and regardless of whether the additional lane ahead can be recognized as an adjacent lane, deceleration assistance is started (step 6). Note that in step 5, confirming that the driver has no intention of accelerating the own vehicle is because the deceleration assistance is conditional on not being contrary to the driver's intention.

[0024] In the deceleration assistance in step 6, the magnitude of the deceleration may be set lower than the deceleration for collision avoidance. The deceleration assistance according to this embodiment decelerates with a margin and starts execution relatively early, so the braking force may be applied in a manner that gives the driver no sense of discomfort and gives a sense of security.

[0025] After the start of deceleration assistance in step 6, when the host vehicle changes lanes and follows behind the preceding vehicle, the deceleration assistance of this embodiment ends. Thereafter, any assistance when there is a preceding vehicle on the host vehicle lane may be executed. Also, while the host vehicle does not change lanes, when a sense of approach occurs between the preceding vehicle outside the host vehicle lane and the host vehicle, that is, when the preceding vehicle outside the host vehicle lane satisfies Thb>TTC or Thebl>ΔL and there is no longer enough room for the host vehicle to follow behind the preceding vehicle, the deceleration assistance of this embodiment ends because it is no longer considered that the host vehicle will change lanes and follow behind the preceding vehicle. In this case, thereafter, since the driver is considered to have the intention of turning right or left (because the direction indicator is being operated), any assistance to decelerate to the extent necessary for a right or left turn may be executed.

[0026] Thus, in the configuration of this embodiment, when there is a preceding vehicle at a position corresponding to an additional lane ahead, before the additional lane ahead is recognized as an adjacent lane, deceleration assistance of the host vehicle can be executed. According to this embodiment, since deceleration assistance is executed more promptly and the start of deceleration assistance can be made at an earlier timing, it is advantageous in that the effect of avoiding the execution of hard braking can also be obtained. The configuration of this embodiment may be applied when an automatic driving control device indicates an intention to change lanes in an autonomous vehicle. (That is, this embodiment is also applicable when the driver is an automatic driving control device.)

[0027] The above description has been made in relation to embodiments of the present invention, but many modifications and changes are easily possible for those skilled in the art, and the present invention is not limited only to the embodiments illustrated above, and it will be apparent that the present invention can be applied to various devices without departing from the concept of the present invention.

Claims

【Claim 1】 A deceleration assistance device for a vehicle, a preceding vehicle determination means for determining whether a preceding vehicle exists within a predetermined range in front of the host vehicle outside the host vehicle lane during travel of the host vehicle; a deceleration control means for decelerating the host vehicle under the establishment of a predetermined condition when the preceding vehicle exists; and a device including the above.

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