JP2009274594A - Lane change support device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that in a conventional lane change support device, white lane information is used only for calculating the relative information between its own vehicle and a peripheral vehicle, and whether or not the lane change support of its own vehicle is allowed is not determined from road information, so that the lane change to a restricted adjacent lane is supported, and acceleration control is performed on a road with a large curvature which may become dangerous when the vehicle speed is increased. <P>SOLUTION: A lane change support device is provided with: a first control mode for permitting a function for supporting lane change; a second control mode for prohibiting the function for supporting lane change; a road information acquisition part for acquiring road information when its own vehicle is traveling; a relative information acquisition part for acquiring the relative information between its own vehicle and the peripheral vehicle; a selection part for selecting a control mode based on the road information acquired by the road acquisition part; and a control part for controlling its own vehicle based on the relative information acquired by the relative information acquisition part and the control mode selected by the selection part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle lane change assisting device.

  Lane driving is a driving operation that places a heavy burden on the driver. Here, the relative distance and relative speed between the vehicle and the surrounding vehicle are detected by the surrounding vehicle detection sensor, the lane in which the surrounding vehicle is traveling is determined based on the white line information on the road, and the lane to be changed There is a technique of performing acceleration / deceleration control on the own vehicle based on the relative distance and relative speed of surrounding vehicles traveling in a lane, and performing steering control after performing acceleration / deceleration control to a position where the lane can be changed (see Patent Document 1).

JP 2005-324727 A

  According to Patent Document 1, the white line information is used only for calculating relative information of the own vehicle and the surrounding vehicles, and it is determined from the road information whether or not it is a place where the lane change support of the own vehicle can be supported. Not. Therefore, there is a problem that the lane change to the adjacent lane where the lane change is prohibited by law is supported, or that acceleration is controlled on a road with a dangerous curve curvature if the speed is further increased.

  Therefore, an object of the present invention is to provide an apparatus that appropriately supports lane change in consideration of not only relative information between the own vehicle and surrounding vehicles but also road information.

  In order to solve the above problems, one of the desirable embodiments of the present invention is as follows.

  The lane change support device includes a first control mode for permitting a function for supporting lane change, a second control mode for prohibiting a function for supporting lane change, and road information for acquiring road information on which the host vehicle is traveling. An acquisition unit, a relative information acquisition unit that acquires relative information between the host vehicle and surrounding vehicles, a selection unit that selects a control mode based on road information acquired by the road information acquisition unit, and an ambient information acquisition unit A control unit is provided that controls the host vehicle based on the relative information and the control mode selected by the selection unit.

  ADVANTAGE OF THE INVENTION According to this invention, the apparatus which supports not only the relative information of the own vehicle and surrounding vehicles but road information can be provided appropriately, and a lane change support can be provided.

(First embodiment)
Hereinafter, a first embodiment will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating a travel support device including a lane change support device. The FL wheel means the left front wheel, the FR wheel means the right front wheel, the RL wheel means the left rear wheel, and the RR wheel means the right rear wheel.

  The driving support device 101 is based on various sensors that recognize the outside world (front camera 2, side millimeter wave radar 3, 4, rear millimeter wave radar 5, wheel speed sensor 22, laser radar 23), and information acquired by the sensors. Various actuators (steering control mechanism 10, brake control mechanism 13, engine control mechanism 20) for driving support, lane change support device 1 for calculating command values to various actuators, and command values from the lane change support device 1 The steering control device 8 that controls the steering control mechanism 10 based on the command value, the brake control device 15 that controls the brake control mechanism 13 based on the command value and adjusts the brake force distribution of each wheel, and the engine control mechanism 20 based on the command value And an engine control device 19 that controls and adjusts the torque output of the engine. The lane change support device 1, the steering control device 8, the brake control device 15, and the engine control device 19 are connected via an in-vehicle network such as a CAN (Controller Area Network).

  The front camera 2 acquires road information such as the position and type of the front lane marker, the legal speed limit, and the like. The laser radar 23, the side millimeter wave radar 3, 4, and the rear millimeter wave radar 5 detect relative information between the own vehicle and the surrounding vehicles. The configuration of the sensor is not limited to this, and may be a combination with an ultrasonic sensor, a stereo camera, an infrared camera, or the like. These sensor signals are input to the lane change assist device 1.

  Here, in the first, second and fifth embodiments, the road information includes the position and type of the lane marker, the number of lanes in the traveling direction of the own vehicle, the presence or absence of a neighboring lane, the presence or absence of an intersection, the presence or absence of a pedestrian crossing, It is described as indicating at least one of the presence / absence of construction, the presence / absence of traffic congestion, the presence / absence of alleys, the presence / absence of oncoming vehicles, the presence / absence of stopped vehicles, and the road surface condition. In this paper, the relative information is described as indicating the relative distance and relative speed between the host vehicle and the surrounding vehicle, but may include other relative information between the host vehicle and the surrounding vehicle.

  The lane change support input device 11 inputs information indicating the driver's intention to the lane change support device 1. As the lane change support input device 11, for example, a direction indicator is used, and it is determined whether or not to perform lane change support based on the ON / OFF information. However, the lane change assist input device 11 is not limited to the direction indicator, and a dedicated input device may be used.

  Next, the operation of the brake will be described. The pedal force of the brake pedal 12 of the driver is boosted by a brake booster (not shown), and a hydraulic pressure corresponding to the force is generated by a master cylinder (not shown). The generated hydraulic pressure is supplied to the wheel cylinder 16 via the brake control mechanism 13. The wheel cylinders 16FL, 16FR, 16RL, and 16RR are composed of pistons, pads, and the like. The pistons are driven by the hydraulic fluid supplied from the master cylinder, and the pads connected to the pistons are pressed against the disk rotor. The disc rotor rotates with the wheels. Therefore, the brake torque acting on the disc rotor becomes a braking force acting between the wheel and the road surface. As described above, a braking force is generated in each wheel in accordance with the driver's brake pedal operation.

  The brake control device 15 includes a sensor signal from the combine sensor 14 (detector for longitudinal acceleration, lateral acceleration, yaw rate), sensor signals from wheel speed sensors 22FL, 22FR, 22RL, 22RR installed on each wheel, and lane change. A brake force command from the support device 1 and a sensor signal from the steering wheel angle detection device 21 via the steering control device 8 are input. The command of the brake control device 15 is output to a brake control mechanism 13 having a pump (not shown) and a control valve, and can generate an arbitrary braking force on each wheel independently of the driver's brake pedal operation. it can. Further, the brake control device 15 estimates vehicle spin, drift-out, and wheel lock based on the above information, and generates a braking force of the corresponding wheel so as to suppress them, thereby improving the driving stability of the driver. Is responsible. In addition, the lane change assist device 1 can generate an arbitrary braking force on the vehicle by transmitting a brake command to the brake control device 15. However, the present invention is not limited to the brake control device, and other actuators such as a brake-by-wire may be used.

  Next, the operation of the steering will be described. The steering torque detection device 7 and the steering wheel angle detection device 21 detect the steering torque and the steering wheel angle input by the driver via the steering wheel 6, respectively. Based on these information, the steering control device 8 controls the motor 9 to obtain the assist torque. generate. The steering control mechanism 10 is moved by the resultant force of the steering torque of the driver and the assist torque by the motor 9, and the front wheels are cut. On the other hand, the reaction force from the road surface is transmitted to the steering control mechanism 10 according to the turning angle of the front wheel, and is transmitted to the driver as the road surface reaction force.

  The steering control device 8 can generate torque by the motor 9 and control the steering control mechanism 10 independently of the driver's steering operation. Therefore, the lane change assist device 1 can control the front wheels to an arbitrary turning angle by transmitting a steering force command to the steering control device 8. However, the present invention is not limited to the steering control device, and other actuators such as steer-by-wire may be used.

  Next, the accelerator will be described. The depression amount of the accelerator pedal 17 of the driver is detected by the stroke sensor 18 and input to the engine control device 19. The engine control device 19 controls the engine by adjusting the throttle opening, the fuel injection amount, and the like in accordance with the accelerator pedal depression amount. Thus, the vehicle can be accelerated according to the driver's accelerator pedal operation. Further, the engine control device 19 can control the throttle opening independently of the driver's accelerator operation. Accordingly, the lane change assist device 1 can generate an arbitrary acceleration in the vehicle by transmitting an acceleration command to the engine control device 19.

  The brake control device 15, the steering control device 8, and the engine control device 19 include a CPU, a ROM, a RAM, an input / output device, and the like.

  With the travel support device 101 described above, the lane change support device 1 can support the lane change by appropriately performing the deceleration control by the brake, the acceleration control by the engine, and the steering control by the steering according to the surrounding situation.

  FIG. 2 is a block diagram of a processing unit of the lane change support device 1.

  The map information database (hereinafter referred to as map information DB) 31 stores node information, link information, and the like, and the node information includes road information.

  The own vehicle position detection unit 30 detects the position of the own vehicle using an artificial satellite such as a GPS (Global Positioning System), and also moves the vehicle by combining information acquired by a direction sensor such as a vehicle speed and a gyro. The own vehicle position may be calculated by integrating the vector, and the own vehicle position may be calculated based on a combination with the signal of the own vehicle position detected by the GPS. In the present embodiment, the vehicle position detection unit 30 and the map information DB 31 are provided inside the lane change support device 1. However, the vehicle position detection unit 30 and the map information DB 31 are provided inside the navigation system and the like, and acquire the vehicle position and road information from the navigation system. May be.

  The road information acquisition unit 32 accesses the map information DB 31 based on the vehicle position calculated by the vehicle position detection unit 30 and acquires road information. Moreover, the road information acquisition part 32 detects road information from the image obtained from the front camera 2, and acquires traffic jam information from VICS (not shown). The information obtained here is output to the control mode selection unit 33. In addition, it is desirable that the road information acquisition unit 32 acquires the information of the road that travels in the meantime taking into account the time taken from the start to the end of the lane change support. However, the road information acquisition method and road information are not limited to the above.

  The control mode selection unit 33 selects a control mode based on the information obtained from the road information acquisition unit 32 and outputs the control mode to the lane change control unit 37 and the control mode notification unit 35.

  The control mode is divided into the function to support lane change for the right lane and the function to support lane change for the left lane, and the control state that combines the permission and prohibition of each function. Say. Note that the function for supporting lane change is to determine whether or not the lane can be changed, and when it is determined that the lane cannot be changed, the lane can be changed by performing acceleration control or deceleration control to a position where the lane can be changed. If it is determined that the lane is changed, the steering control is performed to change the lane. In the control mode in which the lane change support for the right lane is permitted and the lane change support for the left lane is prohibited, the lane change support device 1 supports only the lane change for the right lane, and conversely the left lane. Do not support lane changes when changing lanes.

  The control mode selection unit 33 holds a control mode selection table. FIG. 3 is a diagram illustrating a control mode selection table according to the first embodiment.

  The control mode selection unit 33 refers to the table and selects a control mode. However, the present invention is not limited to using the table. For example, even if there is one lane on one side, it may be determined that lane change is permitted when there is no oncoming vehicle. As another example, when there is a danger of collision if the host vehicle travels as it is, a control mode may be provided in which lane change support is prohibited and automatic braking is applied to prevent a collision. In addition, since a traffic rule changes with countries, it is desirable to construct | assemble the control mode selection part suitable for the country.

  The control mode switching input unit 34 is composed of an input device such as a dial, and switches the control mode based on the input of the driver. However, the input device is not limited to a dial.

  Based on the control mode input from the control mode selection unit 33, the control mode notification unit 35 notifies the driver of which state the control mode is in. FIG. 4 is a diagram illustrating a display screen for the control mode notification unit 35 to notify the driver.

  Based on the control mode, the control mode notification unit 35 displays an arrow in a direction that can support the lane change, and does not display an arrow in a direction that cannot be supported, thereby notifying the driver of the function that the lane change support device 1 can support. In FIG. 4, only lane change support for the right lane is permitted, and support such as lane change for the left lane is prohibited. Also, as in the embodiments described later, for example, when allowing front / rear acceleration / deceleration control and prohibiting steering control, arrows directed to the front / rear direction of the host vehicle are displayed and directed to the left / right direction. The arrow is not displayed. In addition, it may be configured such that, without displaying an arrow, when lane change support is permitted, characters such as “lane change support is possible” are simply displayed, and when it is not permitted, nothing is displayed. Furthermore, another transmission method such as voice may be used. By providing such a control mode notification unit, the driver can know whether or not he / she can assist the lane change before changing the lane.

  The surrounding vehicle information acquisition unit 36 first estimates the vehicle speed based on the information detected by the wheel speed sensor 22. For example, the highest value among the four wheel speed sensors may be set as the vehicle speed, the average value of the wheel speed sensors may be used, or other methods may be used. Next, the surrounding vehicle information acquisition unit 36, based on the estimated own vehicle speed and information on the front laser radar 23, the side millimeter wave radars 3 and 4, the rear millimeter wave radar 5, and the like, The relative information is calculated, and the relative information of the surrounding vehicle obtained here is output to the lane change control unit 37.

  A mode in which the surrounding vehicle information acquisition unit 36 outputs relative information between the own vehicle and the surrounding vehicle to the control mode selection unit 33 will be described in the fourth embodiment.

  The lane change control unit 37 is based on the relative information between the control mode and the surrounding vehicle, the target acceleration to the engine control device 19, the target deceleration to the brake control device 15, and the target steering angle to the steering control device 8. Is output via the in-vehicle network. However, the target values from the lane change control unit 37 to the engine control device 19, the brake control device 15, and the steering control device 8 are not limited to the above.

  Each of the above processing units is generally software, and the CPU reads various programs from a storage device (CD-ROM, DVD-ROM, hard disk, etc.) into a main storage device (RAM, etc.) and executes various programs. Process. Data such as these programs and map information may be stored in advance in a storage device, may be input from another storage medium, or downloaded from another device in an information center or the like via a network. May be. Each of the above processing units may be realized by dedicated hardware or may be realized by a combination of software and hardware.

  FIG. 5 is a flowchart of lane change support.

  First, the surrounding vehicle information acquisition unit 36 calculates relative information with respect to the surrounding vehicle (S501). Next, the road information acquisition unit 32 acquires road information (S502). Next, the control mode selection unit 33 selects a control mode (S503). Next, the control mode notification unit 35 notifies the driver of the control mode (S504). Finally, the lane change control unit 37 performs lane change support according to the control mode (S505). In addition, the timing which alert | reports control mode is not limited to FIG. 5, For example, the time when a driver turned ON the lane change assistance input device 11 may be sufficient.

  FIG. 6 is a flowchart of the lane change control unit 37.

  First, the lane change control unit 37 determines whether or not there is an input for starting lane change support (for example, input of a direction indicator) to the lane change support input device 11 by the driver (S611). If not, the process ends. Next, the lane change control unit 37 determines whether or not the lane change support in the direction in which the driver wants to change the lane in the control mode (for example, the direction in which the direction indicator is blinking) is permitted (S612). ). If permitted, the process proceeds to S613, and if not permitted, the process is terminated. S611 and S612 are steps for determining whether or not the lane change support condition is satisfied. By including such a step, it is possible to prohibit the support of the lane change according to the control mode.

  Next, it is determined whether or not the lane can be changed immediately from the relative position and relative speed between the host vehicle and the other vehicle (S613). If it is determined that the lane can be changed, the process proceeds to S619, where it is determined that the lane cannot be changed. If so, the process proceeds to S614.

  In S619, the lane change control unit 37 detects the distance between the own vehicle position and the target position to change the lane from the front camera, generates a target steering angle so that the own vehicle position matches the target position, and performs steering. The target steering angle is transmitted to the control device 8. The steering control device 8 steering-controls the actual steering angle acquired from the rotary encoder (not shown) toward the target steering angle.

  FIG. 7 is a flowchart (S614 in FIG. 6) for determining a target space for lane change. The target space is a space between vehicles existing in the adjacent lane where the own vehicle is about to enter when the lane change assisting apparatus 1 changes the lane.

  First, the lane change control unit 37 sets a reference vehicle serving as a reference when determining the target space (S711). The reference vehicle is the vehicle in the adjacent lane with the smallest relative distance when the lane is changed (after a certain time). However, the method for determining the reference vehicle is not limited to this, and the vehicle having the shortest current relative distance or the vehicle having the shortest predicted collision time may be used. Next, it is determined whether or not the own vehicle is in front of the reference vehicle when the lane is changed (S712). If it is determined that the vehicle is in front of the reference vehicle, the target space is set in front of the reference vehicle (S713). When it is determined that the vehicle is not in front of (behind) the reference vehicle, the target space is set behind the reference vehicle (S714). It progresses to S615 after S713 and S714. As described above, the target space for changing the lane can be determined according to the relative position and relative speed between the host vehicle and the other vehicle. However, the method of determining the target space for changing lanes is not limited to the above.

Next, details of the calculation method of the target speed in S615 will be described. The lane change control unit 37 operates when the relative distance between the host vehicle and the vehicle ahead of the target space in the adjacent lane is equal to or less than a first predetermined value, and the generated force changes according to the relative distance. Install the model in front of your vehicle. In addition, a virtual spring / damper model in which the relative distance between the vehicle and the vehicle behind the target space in the adjacent lane is below a second predetermined value and the force generated according to the relative distance changes is Provided. It should be noted that the first and second predetermined values are set to a distance at which the driver of the own vehicle does not feel fear when the lane change support is provided, and a distance at which the driver of the vehicle behind the target space does not feel fear. Is desirable. Then, based on the resultant force of the spring / damper model provided at the front of the host vehicle and the force generated by the spring / damper model provided at the rear side of the host vehicle as shown in equations (1) to (4), A target speed V ^ref is calculated.

は仮想バネ・ダンパモデルの自然長（ｉ＝１，２）、

はバネ・ダンパモデルの変化量の最大値、Ｋ_iとＤ_iはそれぞれ、車両ｉに対する仮想バネ・ダンパモデルのバネ定数，ダンパ定数である。尚、ｉ＝１は目標スペースの前方車、ｉ＝２は目標スペースの後方車を表す。車線変更制御部３７が上記目標速度に向けて車両速度を制御することで、自車と周囲車両の間に十分な車間距離が確保され、自車は目標スペースへ向けて車線変更できる状態になる。 However, the relative information of the host vehicle and the other vehicle is expressed in a coordinate system in which the center of gravity of the host vehicle is the origin and the X axis is the front of the vehicle. The relative information between the center of gravity of the own vehicle and the surrounding vehicles is X _i and V _i (i = 1, 2). M is mass, s is Laplace operator, F _i (i = 1, 2) is force, L ₀ is the total length of the host vehicle, and L _i is the total length of the surrounding vehicle i.

Is the natural length of the virtual spring / damper model (i = 1, 2),

Is the maximum change amount of the spring / damper model, and K _i and D _i are the spring constant and damper constant of the virtual spring / damper model for the vehicle i, respectively. Note that i = 1 represents a vehicle ahead of the target space, and i = 2 represents a vehicle behind the target space. The lane change control unit 37 controls the vehicle speed toward the target speed, so that a sufficient inter-vehicle distance is ensured between the own vehicle and the surrounding vehicles, and the own vehicle can be changed to the target space. .

  Next, the lane change control unit 37 determines whether or not the target speed is larger than the own vehicle speed (S616). If larger, the process proceeds to S617, and if smaller, the process proceeds to S618. In S617, the lane change control unit 37 outputs a target acceleration to the engine control device based on the target speed and the own vehicle speed, and performs acceleration control. On the other hand, in S618, the lane change control unit 37 outputs a target deceleration to the brake control device based on the target speed and the estimated host vehicle speed, and performs deceleration control. However, the lane change control unit 37 is not limited to the above.

  FIG. 8 is a diagram illustrating an application example of the first embodiment.

  In FIG. 8A, first, the road information acquisition unit 32 recognizes that there is no lane on the right side of the vehicle as road information and that the lane marker on the left side is a white dotted line. And the control mode selection part 33 prohibits the lane change assistance toward the right lane based on the said road information, and selects the control mode which permits the lane change toward the left lane (No. 2 of FIG. 3). The control mode notification unit 35 notifies the driver that only the lane change toward the left lane can be supported based on the control mode. The lane change control unit 37 supports the lane change only when there is an input from the direction indicator toward the left lane of the driver based on the control mode.

  In FIG. 8B, first, the road information acquisition unit 32 has no lane on the left side of its own vehicle as road information, the right lane marker is a double line of yellow and white dotted lines, and the own vehicle side is a white dotted line. Recognize that. And the control mode selection part 33 prohibits the lane change assistance toward the left lane based on the said road information, and selects the control mode which permits the lane change toward the right lane (No. 3 of FIG. 3). The control mode notification unit 35 notifies the driver that only the lane change toward the right lane can be supported based on the control mode. The lane change control unit 37 supports the lane change only when there is a direction indicator input directed to the right lane of the driver based on the control mode.

  In FIG.8 (c), the road information acquisition part 32 recognizes that it is one lane on one side as road information first. And the control mode selection part 33 selects the control mode which prohibits the lane change assistance toward the left and right lanes based on the said road information (No. 4 of FIG. 3). The control mode notification unit 35 notifies the driver that lane change support cannot be performed based on the control mode. The lane change control unit 37 prohibits lane change support based on the control mode.

  From the above, it is possible to appropriately limit the lane change support for the right lane and the lane change support for the left lane according to the road conditions. As a result, the function of changing lanes can be restricted so as not to violate the law. Furthermore, even if the lane change is permitted by law, if the lane change is dangerous due to the surrounding situation, the lane change support can be prohibited, so that the safety can be improved.

(Second Embodiment)
In the second embodiment, the lane change support is divided into a function for acceleration / deceleration control before and after and a function for steering control, and a control mode is defined by combining permission and prohibition of each function. FIG. 9 is a diagram illustrating a control mode selection table according to the second embodiment.

  The flowchart of the lane change control unit 37 is basically the same as that of the first embodiment. However, the determination of S612 in FIG. 6 is not necessary. Further, the lane change control unit 37 does not execute the acceleration control of S617 and the deceleration control of S618 when acceleration / deceleration control is prohibited based on the control mode, and the steering of S619 when steering control is prohibited. Do not implement control.

  FIG. 10 is a diagram illustrating an application example of the second embodiment.

  In FIG. 10A, first, the road information acquisition unit 32 recognizes that the road information is not a road that hinders acceleration / deceleration control and steering control. Next, the control mode selection unit 33 selects a control mode that permits acceleration / deceleration control and steering control based on the road information (No. 1 in FIG. 9). The control mode notification unit 35 notifies the driver that acceleration / deceleration control and deceleration control can be performed based on the control mode. The lane change control unit 37 supports the lane change according to the driver's direction indicator input based on the control mode.

  In FIG. 10B, first, the road information acquisition unit 32 recognizes that there is an alley in the lane to be changed as the road information. Next, the control mode selection unit 33 selects a control mode that permits acceleration / deceleration control and prohibits steering control based on the road information. The control mode notification unit 35 notifies the driver that only acceleration / deceleration control can be supported based on the control mode. The lane change control unit 37 supports lane change only for acceleration / deceleration control based on the control mode.

  In FIG. 10C, first, the road information acquisition unit 32 recognizes that the road information is one lane on one side. Next, the control mode selection unit 33 selects a control mode for prohibiting acceleration / deceleration control and steering control based on the road information. Based on the control mode, the control mode notification unit 35 informs the driver that acceleration control and steering control cannot be performed. The lane change control unit 37 prohibits acceleration / deceleration control and steering control based on the control mode.

  As described above, acceleration / deceleration control and steering control can be appropriately limited according to the road condition. As a result, the function of changing lanes can be restricted so as not to violate the law. Furthermore, when it is dangerous to change lanes due to the surrounding situation, lane change support can be prohibited, so safety can be improved.

(Third embodiment)
In the third embodiment, the control mode selection unit 33 predicts the risk of the lane and the lane to be changed from the control line used in the lane departure prevention control, and selects the control mode based on the prediction.

  FIG. 11 is a diagram illustrating the operation of the lane departure prevention control device. The lane departure prevention control device is a device for preventing departure from the lane.

  In FIG. 11 (a), the lane departure prevention control device provides a threshold value 38 for departure avoidance control slightly inside the lane in which the host vehicle travels, and the host vehicle is likely to deviate from the threshold value 38 for departure avoidance control. If one of the brakes occurs, the brake on one side is controlled or the steering is controlled to return the vehicle to the own lane.

  In FIG. 11B, when the direction indicator is input, it is determined that the driver has an intention to cross the lane, and the threshold for deviation avoidance control in the direction in which the direction indicator is input is eliminated. As described above, the lane departure prevention control device does not control when there is a driver's intention, and performs brake control or steering control to prevent lane departure when the lane departure is not intended by the driver. Can be prevented.

  In addition to the above control, in FIG. 11C, the lane departure prevention control device corrects the threshold value for departure avoidance control for an object (in the figure, a stopped vehicle) that has a risk of colliding with the own vehicle. By doing so, the lane departure prevention control device can perform brake control or steering control when the host vehicle and the obstacle approach each other, and can prevent a collision between the host vehicle and the obstacle. The road information acquisition unit 32 acquires the deviation avoidance control threshold value as road information and outputs it to the control mode selection unit 33.

  FIG. 12 is a diagram illustrating a control mode selection table according to the third embodiment.

  The control mode selection unit 33 estimates whether or not there is a risk of collision when the host vehicle changes lanes from the threshold value 38 for departure avoidance control. The control mode selection unit 33 permits lane change support when it is determined that there is no risk of collision, and prohibits lane change support when it is determined that there is a risk of collision. The determination of whether or not there is a risk of collision can be made based on, for example, whether or not there is a threshold for departure avoidance control on the trajectory that passes when changing lanes.

(Fourth embodiment)
In the fourth embodiment, the control mode selection unit 33 determines the control mode based on the road information of the speed limit obtained from the legal speed and the curve curvature.

  The following three points are different from the first embodiment. The first point is that the road information acquisition unit 32 detects at least one of the legal maximum speed, the curve curvature, and the “restricted speed calculated from the curve curvature” as road information. The legal maximum speed is acquired by the road information acquisition unit 32 accessing the map information DB 31 based on the vehicle position. However, not limited to the above, in an area where the speed limit changes according to time, the legal maximum speed may be calculated by accessing the map information DB 31 based on the vehicle position and the current time. Further, the legal maximum speed may be detected by recognizing the sign from the camera image. On the other hand, the “restricted speed calculated from the curve curvature” is calculated from the curve curvature obtained from the map information DB 31 as a speed at which the vehicle can safely travel on the curve. The second point is that the lane change support device 1 has a control mode that permits all lane change assistance and a control mode that prohibits all lane change assistance. The third point is that the control mode selection unit 33 determines whether the lane can be changed below the maximum speed based on the legal maximum speed or the relative information between the speed limit and the surrounding vehicle, and determines the control mode. is there.

  The flowchart of the lane change support is basically the same as that of the first embodiment. However, the determination in S612 of FIG. 6 is replaced with “Is lane change support permitted in the control mode?”. Further, the flowchart for determining the target space in FIG. 7 is replaced with FIG.

  FIG. 13 is a flowchart of the control mode selection unit 33. The legal maximum speed or the speed limit is input to the control mode selection unit 33 from the road information acquisition unit 32 as road information. Although the legal maximum speed is shown in FIG. 13, it can also be applied to a curve by substituting “the speed limit calculated from the curve curvature”. Steps S711 to S713 and S714 in FIG. 13 are the same as the steps in FIG.

  After S713, the control mode selection unit 33 determines whether the lane can be changed to the target space at the legal maximum speed or less when the lane change is supported (S1301). Although the above criteria are not particularly limited, whether or not the target speed obtained by equation (1) is less than or equal to the legal maximum speed when it is assumed that the surrounding vehicle moves at a constant speed for a certain period of time (for example, about 2 seconds for lane change). Judge. When the target speed is equal to or lower than the legal maximum speed, the control mode selection unit 33 selects a control mode that permits lane change support (S1302), and ends the process. If the target speed is not less than the legal maximum speed, the control mode selection unit 33 determines that the lane cannot be changed to the target space below the legal maximum speed, and sets the target space behind the reference vehicle (S714). Next, the control mode selection unit 33 determines whether or not the target space set in S714 can change the lane at the legal maximum speed or less (S1303). If the lane change can be supported, the process proceeds to S1302 and ends the process. If the lane cannot be changed, a control mode for prohibiting lane change support is selected (S1304), and the process is terminated. Note that the determination criterion of S1302 is preferably the same determination as that of S1301. As described above, the control mode selection unit 33 permits the control mode for prohibiting the lane change support when the lane change cannot be performed at the legal maximum speed or less, and permits the lane change support when the lane change can be performed at the legal maximum speed or less. You can select the mode.

  FIG. 14 is a diagram illustrating an application example of the fourth embodiment.

  In FIG. 14A, a control mode for permitting lane change support is selected based on the legal maximum speed. First, the road information acquisition unit 32 recognizes that the legal maximum speed is 60 [km / h] from the camera image as road information. Next, the surrounding vehicle information acquisition unit 36 recognizes that the speeds of the other vehicles 1 and 2 are 50 [km / h] and the own vehicle speed is 40 [km / h]. The control mode selection unit 33 determines from the legal maximum speed and the surrounding vehicle information that the legal maximum speed is not exceeded to change the lane, and selects a control mode that permits lane change support. The control mode notification unit 35 notifies the driver that lane change support can be performed based on the control mode. The lane change control unit 37 supports the lane change according to the control mode and the input direction of the direction indicator.

  In FIG. 14B, a control mode for prohibiting lane change support is selected based on the legal maximum speed. First, the road information acquisition unit 32 recognizes that the legal maximum speed is 40 [km / h] as road information. Next, the surrounding vehicle information acquisition unit 36 recognizes that the speed of the vehicles 1 and 2 in the lane whose lane is to be changed is 50 [km / h] and the own vehicle speed is 40 [km / h]. The control mode selection unit 33 determines that the legal maximum speed is exceeded to change the lane based on the legal maximum speed and the surrounding vehicle information, and selects a control mode for prohibiting the lane change support. The control mode notification unit 35 notifies the driver that lane change support cannot be performed based on the control mode. The lane change control unit 37 does not support lane change based on the control mode.

  In FIG.14 (c), the control mode which permits lane change assistance based on a curve curvature is selected. First, the road information acquisition unit 32 detects a curve curvature as road information. Next, it is calculated from the curve curvature that the speed limit at which the curve can be safely bent is 60 [km / h]. Next, the surrounding vehicle information acquisition unit 36 recognizes that the speeds of the other vehicles 1 and 2 are 50 [km / h] and the own vehicle speed is 40 [km / h]. The control mode selection unit 33 determines that the speed limit is not exceeded when the lane change is supported, and selects a control mode that permits the lane change support. The control mode notification unit 35 notifies the driver that lane change support can be performed based on the control mode. The lane change control unit 37 supports the lane change according to the control mode, the relative information, and the direction input by the direction indicator.

  In FIG. 14D, a control mode for prohibiting lane change support is selected based on the curve curvature. First, the road information acquisition unit 32 detects a curve curvature as road information. Then, the speed limit at which the curve can be safely bent is calculated as 40 [km / h] from the curve curvature. Next, the surrounding vehicle information acquisition unit 36 recognizes that the speeds of the other vehicles 1 and 2 are 50 [km / h] and the own vehicle speed is 40 [km / h]. The control mode selection unit 33 determines that the speed limit is exceeded when the lane change is supported, and selects a control mode for prohibiting the lane change support. The control mode notification unit 35 notifies the driver that lane change support cannot be performed based on the control mode. The lane change control unit 37 does not support lane change based on the control mode.

  As shown in FIGS. 14A to 14D, the lane change support can be appropriately prohibited according to the speed limit determined by the legal maximum speed and the curve curvature of the road. As a result, it is possible to realize a lane change support system that keeps the legal maximum speed and improves the safety on the curve.

(Fifth embodiment)
In the fifth embodiment, the control mode selection unit 33 determines a control mode based on information indicating a sensor state (hereinafter, sensor state).

  FIG. 15 is a block diagram of a processing unit of the lane change assisting device 1 according to the fifth embodiment. The difference from the block diagram of the first embodiment is that the road information acquisition unit 32 is a sensor state acquisition unit 40. The sensor state acquisition unit 40 determines whether or not each of the front camera 2, the front laser radar 23, the side millimeter wave radar 3, 4, and the rear millimeter wave radar 5 that recognizes the lane marker can not normally recognize the recognition target. The sensor state indicating is acquired. The state in which the sensor cannot normally recognize the recognition target is a state in which an abnormality detection unit (not shown) detects that the sensor has failed from the power supply voltage or sensor output of the sensor. For example, in the laser radar 23 and the millimeter wave radars 3, 4, and 5, for example, even when the relative speed is 10 [km / h], the sensor is broken when the inter-vehicle distance is constant. That is, it is determined that the sensor cannot recognize the recognition target normally. Other states in which the sensor cannot recognize the recognition target normally include estimating the rainfall with the wiper activation signal, estimating the brightness from the weather, season and time, or recognizing the brightness directly, 2 may determine that the lane marker can no longer be recognized, and may determine that the sensor cannot normally recognize the recognition target. Furthermore, when the lane marker is disappearing or is not written normally during construction and the lane marker cannot be recognized, it may be determined that the recognition target cannot be recognized normally.

  The flowchart of the lane change support is basically the same as that of the first embodiment. However, S502 in FIG. 5 is replaced with “sensor state detection”.

  FIG. 16 is a diagram illustrating a control mode selection table according to the fifth embodiment. In this embodiment, the control mode is divided into acceleration / deceleration control and steering control, and the control mode is defined by combining permission and prohibition of each function.

  When all the sensors are normal, acceleration / deceleration control and steering control are permitted. When only the front camera cannot recognize the lane marker normally, the steering control is prohibited and the acceleration / deceleration control is permitted. In cases other than the above two, acceleration / deceleration control and steering control are prohibited. The control mode selection unit 33 selects a control mode with reference to the table of FIG.

  As described above, the control mode can be appropriately changed according to the sensor state, and it is a part of the function of the lane change support even if the front camera, which conventionally prohibited the lane change support, is abnormal. Acceleration / deceleration control can be continued. Further, since the assistance for changing the lane can be prohibited when the sensor is abnormal, the safety of the lane change assistance device can be improved.

  Although the embodiments have been described above, the specific configuration is not limited to each embodiment, and design changes and the like within the scope not departing from the gist of the invention are included in the present invention.

The figure which shows a driving assistance apparatus. The block diagram of the process part of a lane change assistance apparatus. The figure which shows the control mode selection table of 1st Embodiment. The figure which shows the display screen for a control mode alerting | reporting part to alert | report to a driver. The flowchart of lane change assistance. The flowchart of a lane change control part. The flowchart for determining the target space of a lane change. The figure which shows the application example of 1st Embodiment. The figure which shows the control mode selection table of 2nd Embodiment. The figure which shows the example of application of 2nd Embodiment. The figure which shows operation | movement of a lane departure prevention control apparatus. The figure which shows the control mode selection table of 3rd Embodiment. The flowchart of a control mode selection part. The figure which shows the example of application of 4th Embodiment. The block diagram of the process part of the lane change assistance apparatus of 5th Embodiment. The figure which shows the control mode selection table of 5th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lane change assistance apparatus 2 Camera 3, 4 Side millimeter wave radar 5 Rear millimeter wave radar 6 Handle 7 Steering torque detection apparatus 8 Steering control apparatus 9 Motor 10 Steering control mechanism 11 Lane change assistance input apparatus 12 Brake pedal 13 Brake control mechanism 14 Combine sensor 15 Brake controller 16FL-16RR Wheel cylinder 17 Accelerator pedal 18 Stroke sensor 19 Engine controller 20 Engine control mechanism 21 Handle angle detector 22FL-22RR Wheel speed sensor 23 Laser radar 30 Own vehicle position detector 31 Map information database 32 Road information acquisition unit 33 Control mode selection unit 34 Control mode switching input unit 35 Control mode notification unit 36 Surrounding vehicle information acquisition unit 37 Lane change control unit 101 Driving support device

Claims (18)

A first control mode that permits a function that supports lane change;
A second control mode prohibiting a function to support lane change;
A road information acquisition unit for acquiring road information on which the vehicle travels;
A relative information acquisition unit that acquires relative information between the host vehicle and surrounding vehicles;
A selection unit that selects the control mode based on the road information acquired by the road information acquisition unit;
A lane change assisting device comprising a control unit that controls the host vehicle based on the relative information acquired by the relative information acquisition unit and the control mode selected by the selection unit. A third control mode for prohibiting the first function and allowing the second function;
The lane change assisting device according to claim 1, further comprising a fourth control mode for permitting the first function and prohibiting the second function. The first function is a function that supports a lane change toward a right lane with respect to a lane in which the host vehicle is traveling,
The lane change support device according to claim 2, wherein the second function is a function that supports a lane change toward a left lane with respect to a lane in which the host vehicle travels. The first function is acceleration / deceleration control,
The lane change assist device according to claim 2, wherein the second function is steering control. The lane change support device according to claim 1, further comprising a fifth control mode for performing deceleration control of the host vehicle.   The road information includes the type of lane marker, the number of lanes in the traveling direction of the host vehicle, the presence or absence of a neighboring lane, the presence or absence of an intersection, the presence or absence of a pedestrian crossing, the presence or absence of construction, the presence or absence of a traffic jam, the presence or absence of an oncoming road, The lane change support device according to claim 1 or 2, wherein the lane change support device is at least one of presence / absence of a stopped vehicle and a road surface state. A lane departure prevention control device for preventing lane departure;
The lane change support device according to claim 1 or 2, wherein the road information is a threshold value for departure avoidance control generated by the lane departure prevention control device.   The lane change support device according to claim 1, wherein the road information is at least one of a legal maximum speed of a lane in which the host vehicle is traveling and a speed limit calculated from a curve curvature. The selection unit determines whether the own vehicle speed exceeds the legal maximum speed or the speed limit when assisting lane change;
If it is determined that it does not exceed, select the first control mode,
The lane change support device according to claim 8, wherein the second control mode is selected when it is determined that the number is exceeded. A first control mode that permits a function that supports lane change;
A second control mode prohibiting a function to support lane change;
A relative information acquisition unit that acquires relative information between the host vehicle and surrounding vehicles;
A sensor state acquisition unit for acquiring a sensor state indicating whether or not the sensor mounted on the host vehicle is in a state where the recognition target cannot be recognized;
A selection unit for selecting a control mode based on the sensor state acquired by the sensor state acquisition unit;
A lane change support device comprising a control unit that controls the host vehicle based on the relative information acquired by the relative information income unit and the control mode selected by the selection unit. A third control mode for prohibiting the first function and allowing the second function;
The lane change assist device according to claim 10, further comprising a fourth control mode for permitting the first function and prohibiting the second function. The first function is acceleration / deceleration control,
The lane change assisting device according to claim 11, wherein the second function is steering control.   The sensor state acquisition unit determines whether the sensor is in a state where it cannot recognize a recognition target, whether the sensor output, the power supply voltage of the sensor, weather, season, time, wiper activation state, and environmental brightness. The lane change support device according to claim 10 or 11, which is acquired based on at least one of the two.   The lane change support device according to claim 1, 2, 10, or 11, wherein the selection unit selects the control mode based on a map in which the sensor state and the control mode are associated with each other.   The lane change support device according to claim 1, 2, 10, or 11, further comprising a control mode notification unit that transmits the control mode to a driver.   The control unit determines whether or not a lane change is possible based on the relative distance and the relative speed, and when determining that the lane cannot be changed, determines a target space to change the lane based on the relative distance and the relative speed, and The target speed is calculated toward the target speed, the acceleration control or the deceleration control is performed toward the target speed, and if it is determined that the lane can be changed, the steering control is performed toward the adjacent lane. Lane change support device.   The lane change assisting device according to claim 1, 2, 10, or 11, further comprising a control mode switching input unit that switches the control mode according to a driver input.   The lane change support device according to claim 1 or 10, wherein the relative information is a relative distance and a relative speed between the host vehicle and the surrounding vehicle.

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