JP2017074823A - Lane change support apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lane change support apparatus capable of determining the permissibility of a lane change minimizing discomfort for a driver.SOLUTION: A lane change support apparatus 100 includes an external sensor 2, an another-vehicle determination part 14, and a lane change permissibility determination part 16. In a case where another vehicle 55 travelling in an adjacent lane is a preceding vehicle 51, and if an inter-vehicular distance to the preceding vehicle 51 is equal to or more than a first distance threshold, with collision prediction time, the time to collide with the preceding vehicle 51, equal to or more than a first temporal threshold, the lane change permissibility determination part 16 determines that a lane change is permissible. In a case where another vehicle 55 traveling in the adjacent lane is a following vehicle 52, and if an inter-vehicular distance to the following vehicle 52 is equal to or more than a second distance threshold that is larger than the first distance threshold, with collision prediction time, the time to collide with the following vehicle 52, equal to or more than a second temporal threshold that is larger than the first temporal threshold, the lane change permissibility determination part 16 determines that a lane change is permissible.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a lane change support device.

  Conventionally, the technique described in Patent Document 1 is known as a lane change support device that changes a lane of a host vehicle from a host lane to an adjacent lane. In the lane change assist device described in Patent Literature 1, when there is a possibility that the own vehicle may come into contact with another vehicle when there is another vehicle (obstacle) in the adjacent lane, it is determined that the lane change is impossible. Thus, the position in the lane width direction of the host vehicle is maintained in the host lane.

JP 2009-078736 A

  For example, when another vehicle traveling in the adjacent lane is a succeeding vehicle, the driver tends to have difficulty in understanding a sense of distance or speed with respect to the other vehicle. On the other hand, for example, when the other vehicle traveling in the adjacent lane is a preceding vehicle, the driver tends to easily grasp the sense of distance and speed with respect to the other vehicle. However, in the lane change assist device, the lane change possibility determination (determination of lane change possibility) is performed regardless of whether the other vehicle traveling in the adjacent lane is the preceding vehicle or the succeeding vehicle. For this reason, there is a possibility that the lane change possibility determination which is uncomfortable for the driver is performed.

  It is an object of the present invention to provide a lane change support device that can determine whether or not a lane can be changed with little discomfort for the driver.

  A lane change support device according to the present invention is a lane change support device that changes a host vehicle from a host lane to an adjacent lane, and is detected by a peripheral information detection unit that detects peripheral information of the host vehicle, and a peripheral information detection unit. Another vehicle determination unit that determines whether the other vehicle traveling in the adjacent lane is a preceding vehicle traveling in front of the own vehicle or a subsequent vehicle traveling behind the own vehicle based on the surrounding information A lane change enable / disable determining unit that performs a lane change enable / disable determining unit that determines whether or not the lane of the host vehicle can be changed based on the surrounding information detected by the information detecting unit and the determination result of the other vehicle determining unit. Is the inter-vehicle distance between the host vehicle and the other vehicle at the time of completion of the lane change or the inter-vehicle distance from the start of the lane change to the completion of the lane change, and the predicted collision time between the own vehicle and the other vehicle at the start of the lane change, or Lane change When the predicted collision time from the start time to the completion time is calculated, and the other vehicle is a preceding vehicle, the inter-vehicle distance is equal to or greater than the first distance threshold and the predicted collision time is equal to or greater than the first time threshold. When it is determined that the lane change is possible and the other vehicle is a succeeding vehicle, the inter-vehicle distance is equal to or greater than the second distance threshold value that is greater than the first distance threshold value, and the collision prediction time is greater than the first time threshold value. When the second time threshold is exceeded, it is determined that the lane change is possible.

  In this lane change support device, when another vehicle is a preceding vehicle, it is determined that the lane change is possible when the inter-vehicle distance is equal to or greater than the first distance threshold and the predicted collision time is equal to or greater than the first time threshold. To do. When the other vehicle is a succeeding vehicle, the lane when the inter-vehicle distance is equal to or greater than the second distance threshold greater than the first distance threshold and the predicted collision time is equal to or greater than the second time threshold greater than the first time threshold. It is determined that the change is possible. Thereby, for example, the threshold value of the determination in the lane change possibility determination can be switched according to a sense of distance or a sense of speed with the other vehicle that differs depending on whether the other vehicle is a preceding vehicle or a succeeding vehicle. As a result, it is possible to determine whether or not to change the lane with less discomfort for the driver.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the lane change assistance apparatus which can perform lane change possibility determination with little uncomfortable feeling for a driver | operator.

It is a block diagram which shows the structure outline | summary of the lane change assistance apparatus which concerns on embodiment of this invention. It is a figure for demonstrating the distance between the own vehicle and the following vehicle. It is a figure for demonstrating the collision prediction time of the own vehicle and a succeeding vehicle. It is a figure for demonstrating the relationship between the own vehicle and a preceding vehicle. It is a figure for demonstrating the relationship between the own vehicle and a succeeding vehicle. It is a flowchart which shows the process of other vehicle determination, and the process of lane change possibility determination.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same or equivalent elements will be denoted by the same reference numerals, and redundant description will be omitted.

  FIG. 1 is a block diagram showing a schematic configuration of a lane change support device 100 according to an embodiment of the present invention. In FIG. 1, a lane change support device 100 is a device that is mounted on a host vehicle such as an automobile and that controls traveling of the host vehicle. The lane change support device 100 performs lane change support for changing the lane of the host vehicle from the own lane to the adjacent lane (lane change), for example, during automatic driving in which the host vehicle automatically runs based on a travel plan.

Automatic driving means that the vehicle is driven mainly by the device. The automatic driving may be a fully automatic driving in which an occupant of the own vehicle is not involved in driving, or may be driving by driving support control in which the driving is performed by the apparatus main body while receiving support from the occupant of the own vehicle.
The own lane is a lane in which the own vehicle is currently traveling. The adjacent lane is a lane extending adjacent to the own lane. The adjacent lane is the destination lane in which the traveling direction is the same as the own lane and the lane change of the own vehicle.

  The lane change assist device 100 includes an ECU [Electronic Control Unit] 10. The ECU 10 is an electronic control unit that controls traveling of the host vehicle, and is configured mainly by a computer including a CPU [Central Processing Unit], a ROM [Read Only Memory], and a RAM [Random Access Memory]. Details of the ECU 10 will be described later. An external sensor (peripheral information detection unit) 2, a GPS [Global Positioning System] reception unit 3, an internal sensor 4, a map database 5, a winker operation detection unit 6, a navigation system 7, and an actuator 8 are connected to the ECU 10. Yes.

  The external sensor 2 is a detection device that detects surrounding information of the host vehicle. The peripheral information is, for example, information within a range of a predetermined distance set in advance from the own vehicle with the own vehicle as the center. The peripheral information includes, for example, information related to other vehicles around the host vehicle. The information regarding the other vehicle includes, for example, the presence / absence of another vehicle traveling in the adjacent lane, the position of the other vehicle with respect to the own vehicle, and the distance between the own vehicle and the other vehicle. Other vehicles include a preceding vehicle and a following vehicle. The predetermined distance can be set to 150 m, for example. The predetermined distance may be a fixed value or a variable value.

  The preceding vehicle is another vehicle that travels ahead of the host vehicle in the adjacent lane. For example, the preceding vehicle is the other vehicle closest to the host vehicle among the other vehicles traveling in front of the host vehicle in the adjacent lane. No other vehicle is interposed between the host vehicle and the preceding vehicle. The following vehicle is another vehicle that travels behind the host vehicle in the adjacent lane. For example, the following vehicle is the other vehicle closest to the host vehicle among the other vehicles traveling behind the host vehicle in the adjacent lane. No other vehicle is interposed between the host vehicle and the following vehicle.

  The external sensor 2 includes at least one of a camera, a radar [Radar], and a rider [LIDAR: Laser Imaging Detection and Ranging]. The camera is an imaging device that images the periphery of the host vehicle. For example, the camera is provided on the back side of the windshield of the host vehicle. The camera transmits imaging information related to the periphery of the host vehicle to the ECU 10. The camera may be a monocular camera or a stereo camera.

  The radar detects obstacles outside the host vehicle using radio waves (for example, millimeter waves). The radar detects an obstacle by transmitting a radio wave around the vehicle and receiving the radio wave reflected by the obstacle. The radar transmits the detected obstacle information to the ECU 10. The rider uses light to detect an obstacle outside the host vehicle. The rider emits light around the vehicle and receives the light reflected by the obstacle, thereby measuring the distance to the reflection point and detecting the obstacle. The rider transmits the detected obstacle information to the ECU 10. The cameras, riders, and radars as the external sensor 2 do not necessarily have to be provided in duplicate.

  The GPS receiver 3 measures the position of the host vehicle (for example, the latitude and longitude of the host vehicle) by receiving signals from three or more GPS satellites. The GPS receiving unit 3 transmits the measured position information of the own vehicle to the ECU 10. Instead of the GPS receiver 3, other means that can specify the latitude and longitude of the host vehicle may be used.

  The internal sensor 4 is a detection device that detects the traveling state of the host vehicle. The internal sensor 4 includes at least one of a vehicle speed sensor, an acceleration sensor, and a yaw rate sensor. The vehicle speed sensor is a detector that detects the speed of the host vehicle. As the vehicle speed sensor, for example, a wheel speed sensor that is provided for a vehicle wheel or a member such as a drive shaft that rotates integrally with the wheel or rotates synchronously and detects the rotation speed of the wheel is used. The vehicle speed sensor transmits the detected vehicle speed information to the ECU 10.

  The acceleration sensor is a detector that detects the acceleration of the host vehicle. The acceleration sensor includes, for example, a longitudinal acceleration sensor that detects acceleration in the longitudinal direction of the host vehicle and a lateral acceleration sensor that detects lateral acceleration of the host vehicle. For example, the acceleration sensor transmits vehicle acceleration information to the ECU 10. The yaw rate sensor is a detector that detects the yaw rate (rotational angular velocity) around the vertical axis of the center of gravity of the host vehicle. As the yaw rate sensor, for example, a gyro sensor can be used. The yaw rate sensor transmits the detected yaw rate information of the host vehicle to the ECU 10.

  The map database 5 is a database provided with map information. The map database is formed in, for example, an HDD [Hard disk drive] mounted on the host vehicle. The map information includes, for example, road position information, road shape information (eg, curve, straight line type, curve curvature, etc.), and road lane number information. Furthermore, it is preferable to include the output signal of the external sensor 2 in the map information in order to use the positional information of shielding structures such as buildings and walls, and SLAM (Simultaneous Localization and Mapping) technology. The map database 5 may be stored in a computer of a facility such as an information processing center that can communicate with the host vehicle.

  The turn signal operation detection unit 6 is provided with respect to a turn signal lever of the host vehicle, for example. The winker operation detection unit 6 detects an operation of the winker lever by the driver (hereinafter simply referred to as “winker operation”). The turn signal operation detection unit 6 detects whether the turn signal operation is a right turn signal operation or a left turn signal operation. The turn signal operation detection unit 6 transmits turn signal operation information related to the detected turn signal operation to the ECU 10.

  The navigation system 7 is a device that provides guidance to the driver of the host vehicle up to a destination set by the driver of the host vehicle. The navigation system 7 recognizes the own lane and the adjacent lane based on the position information of the own vehicle measured by the GPS receiver 3 and the map information in the map database 5 and calculates the route on which the own vehicle travels. The route may specify a suitable lane including a lane change of the own vehicle from the own lane to the adjacent lane in a plurality of lane sections. For example, the navigation system 7 calculates a target route from the position of the host vehicle to the destination, and notifies the driver of the target route by displaying the display and outputting sound from a speaker. For example, the navigation system 7 transmits information on the target route of the host vehicle to the ECU 10. The navigation system 7 may be stored in a computer of a facility such as an information processing center that can communicate with the host vehicle.

  The actuator 8 is a device that executes automatic driving control including traveling control of the host vehicle. The actuator 8 includes at least an engine actuator, a brake actuator, and a steering actuator. The engine actuator controls the amount of air supplied to the engine (throttle opening) in accordance with a control signal from the ECU 10 to control the driving force of the host vehicle. When the host vehicle is a hybrid vehicle or an electric vehicle, a control signal from the ECU 10 is input to a motor as a power source to control the driving force.

  The brake actuator controls the brake system according to a control signal from the ECU 10 and controls the braking force applied to the wheels of the host vehicle. As the brake system, for example, a hydraulic brake system can be used. The steering actuator controls driving of an assist motor that controls steering torque in the electric power steering system in accordance with a control signal from the ECU 10. Thereby, the steering actuator controls the steering torque of the host vehicle.

  The ECU 10 includes an external situation recognition unit 11, a vehicle position recognition unit 12, a travel plan generation unit 13, another vehicle determination unit 14, a lane change intention determination unit 15, a lane change availability determination unit (lane change availability determination unit) 16, and a travel A control unit 17 is provided.

  The external situation recognition unit 11 recognizes the external situation of the host vehicle based on the detection results of the external sensor 2 (for example, camera imaging information, radar obstacle information, rider obstacle information, etc.). The external situation includes other vehicle conditions around the host vehicle (for example, the position and speed of other surrounding vehicles), the shape of the road (for example, curvature of the driving lane), and the situation of obstacles around the vehicle (for example, fixed obstacles) Information for distinguishing an obstacle from a moving obstacle, the position of the obstacle, the moving direction of the moving obstacle, the speed, etc.). The external situation includes the situation of other vehicles in the adjacent lane (for example, the position and speed of other vehicles).

  The vehicle position recognition unit 12 recognizes the position of the own vehicle on the map (hereinafter referred to as “vehicle position”) based on the position information of the own vehicle received by the GPS receiving unit 3 and the map information of the map database 5. . Note that the vehicle position recognition unit 12 may acquire and recognize the vehicle position used in the navigation system 7 from the navigation system 7. When the vehicle position of the host vehicle can be measured by a sensor installed outside a road or the like, the vehicle position recognition unit 12 may acquire the vehicle position by communication from this sensor.

  The travel plan generation unit 13, for example, the target route calculated by the navigation system 7, the vehicle position recognized by the vehicle position recognition unit 12, and the external situation (vehicle position) recognized by the external situation recognition unit 11. , Including the direction), the course of the host vehicle is generated. The course is a trajectory that the host vehicle travels on the target route. The course includes a trajectory that allows the own vehicle to change lanes from the own lane to the adjacent lane.

  The travel plan generation unit 13 generates a route so that the host vehicle travels appropriately on the target route in accordance with standards such as safety, legal compliance, and travel efficiency. At this time, needless to say, the travel plan generation unit 13 generates the course of the host vehicle so as to avoid contact with the obstacle based on the situation of the obstacles around the host vehicle.

  The travel plan generation unit 13 generates a travel plan according to the generated route. That is, the travel plan generation unit 13 generates a travel plan along a preset target route based at least on the external situation that is the surrounding information of the host vehicle and the map information in the map database 5. The travel plan generation unit 13 generates a travel plan for changing the own vehicle traveling in the own lane to the adjacent lane.

  The travel plan generation unit 13 preferably generates a travel plan that includes two elements, a target position p in a coordinate system in which the course of the host vehicle is fixed to the host vehicle, and a speed v at each target point. That is, it outputs as having a plurality of coordination coordinates (p, v). Here, each target position p has at least x-coordinate and y-coordinate positions in a coordinate system fixed to the host vehicle or information equivalent thereto. The travel plan is not particularly limited as long as it describes the behavior of the host vehicle. The travel plan may use, for example, the target time t instead of the speed v, or may be the one added with the target time t and the direction of the host vehicle at that time.

  In general, for the travel plan, future data that is a few seconds ahead of the current time is generally sufficient, but depending on the situation such as turning right at the intersection or passing the vehicle, data of several tens of seconds is required. The number of coordination coordinates is preferably variable, and the distance between the coordination coordinates is also variable. Furthermore, a curve connecting the coordination coordinates may be approximated by a spline function or the like, and the parameters of the curve may be set as a travel plan. Any known method can be used for generating the travel plan as long as it can describe the behavior of the host vehicle.

  The travel plan may be data indicating changes in the vehicle speed, acceleration / deceleration, steering torque, and the like of the host vehicle when the host vehicle travels along a route along the target route. The travel plan may include a speed pattern, an acceleration / deceleration pattern, and a steering pattern of the host vehicle.

  Incidentally, the speed pattern is data including a target vehicle speed set in association with time for each target control position with respect to a target control position set at a predetermined interval (for example, 1 m) on the course. The acceleration / deceleration pattern is data including target acceleration / deceleration set in association with time for each target control position with respect to the target control position set at a predetermined interval (for example, 1 m) on the course. The steering pattern is, for example, data including target steering torque set in association with time for each target control position with respect to the target control position set at a predetermined interval (for example, 1 m) on the course.

  Based on the external situation recognized by the external situation recognition unit 11, the other vehicle determination unit 14 determines whether the other vehicle is a preceding vehicle or a subsequent vehicle when there is another vehicle in the adjacent lane ( Other vehicle judgment). For example, when the external situation recognition unit 11 recognizes another vehicle ahead of the host vehicle in the adjacent lane, the other vehicle determination unit 14 determines that the other vehicle is a preceding vehicle. For example, when the external situation recognition unit 11 recognizes another vehicle behind the host vehicle in the adjacent lane, the other vehicle determination unit 14 determines that the other vehicle is a subsequent vehicle.

  The lane change intention determination unit 15 determines the presence / absence of the driver's intention to change the lane based on the detection result of the winker operation detection unit 6. For example, the lane change intention determination unit 15 determines that the driver has an intention to change the lane when the turn signal operation detection unit 6 detects a turn signal operation for operating the turn signal on the adjacent lane during automatic driving.

  Based on the external situation recognized by the external situation recognition unit 11 and the travel plan generated by the travel plan generation unit 13, the lane change permission determination unit 16 determines whether the other vehicle exists in the adjacent lane. An inter-vehicle distance from the vehicle (hereinafter also simply referred to as “inter-vehicle distance”) is calculated. As shown in FIG. 2, the inter-vehicle distance here is an interval between the host vehicle 50 and the other vehicle 55 in the extending direction of the host lane L1. The lane change permission determination unit 16 calculates and predicts the inter-vehicle distance when the lane change is completed. When the lane change is completed, the lane change ends normally. When the lane change is completed, it is a future time point when the automatic driving related to the lane change is returned to the normal automatic driving.

  Based on the external situation recognized by the external situation recognition unit 11 and the travel plan generated by the travel plan generation unit 13, the lane change permission determination unit 16 determines whether the other vehicle exists in the adjacent lane. A relative speed with the vehicle (hereinafter also simply referred to as “relative speed”) is calculated. The relative speed here is the difference between the speed of the host vehicle 50 in the direction in which the host lane L1 extends and the speed of the other vehicle 55 in the direction.

  Based on the external situation recognized by the external situation recognition unit 11 and the travel plan generated by the travel plan generation unit 13, the lane change permission determination unit 16 determines whether the other vehicle exists in the adjacent lane. A collision prediction time with a vehicle (TTC [Time To Collision], hereinafter, also simply referred to as “collision prediction time”) is calculated. The collision prediction time is a time obtained by dividing the calculated inter-vehicle distance by the relative speed. As shown in FIG. 3, the collision prediction time here is a collision prediction time between the host vehicle 50 and the other vehicle 55 in the extending direction of the host lane L1. The lane change permission determination unit 16 calculates a predicted collision time at the start of the lane change. The lane change start time is the time when the lane change starts. The start of the lane change is the current time (current time).

  The lane change permission determination unit 16 determines whether the lane change of the host vehicle 50 is possible based on the calculated inter-vehicle distance and collision prediction time and the determination result of the other vehicle determination unit 14 (lane change permission determination). The lane change permission determination unit 16 may determine that the lane change of the host vehicle 50 is impossible when the host lane L1 on which the host vehicle 50 travels is a single lane.

  The lane change permission determination unit 16 determines whether the first condition related to the inter-vehicle distance and the second condition related to the predicted collision time are satisfied using different threshold values when the other vehicle 55 is the preceding vehicle 51 and the following vehicle 52. Whether or not lane change is possible is determined. That is, when the other vehicle determination unit 14 determines that the other vehicle 55 is the preceding vehicle 51, the lane change permission determination unit 16 has an inter-vehicle distance that is greater than or equal to the first distance threshold and a predicted collision time of the first time. When it is equal to or greater than the threshold value, it is determined that a lane change is possible. When the other vehicle determination unit 14 determines that the other vehicle 55 is the succeeding vehicle 52, the lane change permission determination unit 16 has an inter-vehicle distance that is greater than or equal to a second distance threshold value that is greater than the first distance threshold value, and a collision prediction. When the time is equal to or greater than a second time threshold value that is greater than the first time threshold value, it is determined that a lane change is possible.

  The first distance threshold value, the first time threshold value, the second distance threshold value, and the second time threshold value are threshold values for the lane change permission determination unit 16 to determine whether the lane change of the host vehicle 50 is possible. The first distance threshold is a threshold related to the inter-vehicle distance when the other vehicle 55 is the preceding vehicle 51. The first time threshold value is a threshold value related to the collision prediction time when the other vehicle 55 is the preceding vehicle 51. The second distance threshold is a threshold related to the inter-vehicle distance when the other vehicle 55 is the succeeding vehicle 52. The second time threshold value is a threshold value related to the collision prediction time when the other vehicle 55 is the subsequent vehicle 52. As an example, the first distance threshold is set to 5 m. As an example, the first time threshold is set to 3 seconds. The second distance threshold is larger than the first distance threshold, and is set to 10 m as an example. The second time threshold value is larger than the first time threshold value, and is set to 6 seconds as an example. The values of the first distance threshold, the first time threshold, the second distance threshold, and the second time threshold are not limited to the example described above. The first distance threshold, the first time threshold, the second distance threshold, and the second time threshold may be fixed values or fluctuating values. The first distance threshold, the first time threshold, the second distance threshold, and the second time threshold may be values determined by, for example, experiments or may be values determined by simulation.

  The travel control unit 17 automatically controls the travel of the host vehicle 50 based on the travel plan generated by the travel plan generation unit 13. The travel control unit 17 automatically controls the travel of the host vehicle 50 according to the determination result of the lane change permission determination unit 16, and executes the lane change of the host vehicle 50 from the host lane L1 to the adjacent lane L2.

  The traveling control unit 17 starts or executes a lane change of the host vehicle 50 from the host lane L1 to the adjacent lane L2 when the lane change permission determination unit 16 determines that the lane change of the host vehicle 50 is possible. Continue the lane change inside. The travel control unit 17 does not start the lane change of the host vehicle 50 from the host lane L1 to the adjacent lane L2 when the lane change permission determination unit 16 determines that the lane change of the host vehicle 50 is impossible. , Cancel (cancel) the lane change being executed.

  In the lane change assist device 100 configured as described above, when the driver performs a winker operation during automatic driving by the travel control unit 17 based on the travel plan, the winker operation detection unit 6 detects the winker operation. The The lane change intention determination unit 15 determines that the driver has an intention of lane change, and the travel control unit 17 starts lane change support. In the lane change support, the other vehicle determination unit 14 determines whether the other vehicle 55 is the preceding vehicle 51 or the following vehicle 52. In accordance with the determination result of the other vehicle determination unit 14, the lane change permission determination unit 16 performs lane change permission determination.

  For example, as shown in FIG. 4, when the other vehicle 55 is the preceding vehicle 51, the distance between the host vehicle 50 and the preceding vehicle 51 when the lane change is completed is equal to or greater than the first distance threshold, and the lane change is started. When the predicted collision time between the host vehicle 50 and the preceding vehicle 51 is equal to or greater than the first time threshold, it is determined that the lane change of the host vehicle 50 from the host lane L1 to the adjacent lane L2 is possible. For example, when the distance between the vehicles at the time of the lane change is less than the first distance threshold, or when the predicted collision time at the start of the lane change is less than the first time threshold, the lane change of the host vehicle 50 is impossible. It is determined.

  On the other hand, for example, as shown in FIG. 5, when the other vehicle 55 is the following vehicle 52, the distance between the own vehicle 50 and the following vehicle 52 when the lane change is completed is equal to or greater than the second distance threshold, and the lane change When the predicted collision time between the host vehicle 50 and the following vehicle 52 at the start is equal to or greater than the second time threshold, it is determined that the lane change of the host vehicle 50 from the host lane L1 to the adjacent lane L2 is possible. For example, when the inter-vehicle distance between the own vehicle 50 and the following vehicle 52 at the time of completion of the lane change is less than the second distance threshold, or the predicted collision time between the own vehicle 50 and the following vehicle 52 at the start of the lane change is the second time. When it is less than the threshold value, it is determined that the lane change of the host vehicle 50 is impossible.

  In the lane change support, the lane change of the host vehicle is controlled by the travel control unit 17 according to the determination result of the lane change permission determination unit 16. Specifically, when the lane change permission determination unit 16 determines that the lane change is possible, the lane change of the host vehicle 50 is performed by the travel control unit 17 based on the lane change travel plan generated by the travel plan generation unit 13. Is executed. When the lane change is completed, the lane change support is terminated. On the other hand, in the lane change support, when the lane change permission determination unit 16 determines that the lane change is not possible, the lane change of the host vehicle 50 is not started or the lane change being executed is stopped.

  In the lane change support device 100, as shown in FIGS. 4 and 5, for example, when the relative positional relationship and speed relationship of the host vehicle 50 or the other vehicle 55 are the same (mutual positional relationship and speed relationship). However, when the other vehicle 55 is the preceding vehicle 51, the system cancellation timing for determining that the lane change is impossible is as follows. Compared with the system cancellation timing for determining that the lane change is impossible when the vehicle 55 is the succeeding vehicle 52, the vehicle 55 is delayed.

  Incidentally, the external situation recognition unit 11, the vehicle position recognition unit 12, the travel plan generation unit 13, the other vehicle determination unit 14, the lane change intention determination unit 15, the lane change availability determination unit 16, and the travel control unit 17 described above are included in the ECU 10. What is necessary is just to comprise by introducing the software or program which implement | achieves each function in. Further, some or all of them may be configured by individual electronic control units.

  Next, the determination process related to the other vehicle determination and the lane change permission determination in the lane change support by the lane change support device 100 will be described in detail. FIG. 6 is a flowchart showing processing of other vehicle determination and lane change availability determination. As shown in FIG. 6, first, the lane change permission determination unit 16 determines whether or not the preceding vehicle 51 exists in the adjacent lane L2 (S1). When it is determined in S1 that the preceding vehicle 51 is present in the adjacent lane L2, the lane change possibility determination unit 16 calculates the inter-vehicle distance between the host vehicle 50 and the preceding vehicle 51 and the predicted collision time (S2).

  Subsequently, the lane change possibility determination unit 16 determines whether the inter-vehicle distance between the host vehicle 50 and the preceding vehicle 51 is equal to or greater than a first distance threshold (S3). When it is determined in S3 that the inter-vehicle distance is greater than or equal to the first distance threshold, it is determined whether or not the predicted collision time between the host vehicle 50 and the preceding vehicle 51 is greater than or equal to the first time threshold (S4). If it is determined in S4 that the predicted collision time is equal to or greater than the first time threshold, the lane change permission determination unit 16 determines that a lane change is possible (S5). Thereafter, the process proceeds to S1, and the determination process is executed again.

  On the other hand, when it is determined in S3 that the inter-vehicle distance is less than the first distance threshold, the lane change permission determination unit 16 determines that the lane change is impossible (S6). When it is determined in S4 that the predicted collision time is less than the first time threshold, the lane change permission determination unit 16 determines that the lane change is impossible (S6). Thereafter, the process proceeds to S1, and the determination process is executed again.

  On the other hand, when it is determined in S1 that the preceding vehicle 51 does not exist in the adjacent lane L2, the lane change permission determination unit 16 determines whether or not the subsequent vehicle 52 exists in the adjacent lane L2 (S7). If it is determined in S7 that the subsequent vehicle 52 is present in the adjacent lane L2, the lane change permission determination unit 16 calculates the inter-vehicle distance between the host vehicle 50 and the subsequent vehicle 52 and the predicted collision time (S8).

  Subsequently, the lane change possibility determination unit 16 determines whether or not the inter-vehicle distance between the host vehicle 50 and the following vehicle 52 is equal to or greater than a second distance threshold (S9). If it is determined in S9 that the inter-vehicle distance is greater than or equal to the second distance threshold, it is determined whether or not the predicted collision time between the host vehicle 50 and the following vehicle 52 is greater than or equal to the second time threshold (S10). When it is determined in S10 that the predicted collision time is equal to or greater than the second time threshold, the lane change permission determination unit 16 determines that a lane change is possible (S11). Thereafter, the process proceeds to S1, and the determination process is executed again.

  On the other hand, when it is determined in S9 that the inter-vehicle distance is less than the second distance threshold, the lane change permission determination unit 16 determines that the lane change is impossible (S12). When it is determined in S10 that the predicted collision time is less than the second time threshold, the lane change permission determination unit 16 determines that the lane change is impossible (S12). Thereafter, the process proceeds to S1, and the determination process is executed again.

  When it is determined in S10 that the following vehicle 52 does not exist in the adjacent lane L2, the lane change permission determination unit 16 determines that a lane change is possible (S13). Thereafter, the process proceeds to S1, and the determination process is executed again. In addition, when the automatic driving | operation of the own vehicle 50 is complete | finished, even if it is in the middle of a flowchart, the said series of processes are complete | finished.

  Here, when the other vehicle 55 traveling in the adjacent lane L <b> 2 is the subsequent vehicle 52, the driver tends to hardly grasp the sense of distance or the speed with respect to the subsequent vehicle 52. Therefore, for example, when the other vehicle 55 is the following vehicle 52 that is located sufficiently away from the host vehicle 50, even if the lane change permission determination is made that the lane change is impossible, the driver is Hard to give a sense of incongruity.

  On the other hand, for example, when the other vehicle 55 traveling in the adjacent lane L2 is the preceding vehicle 51, the driver tends to easily grasp the sense of distance and speed with respect to the preceding vehicle 51. However, in the conventional lane change assist device described above, whether or not to change the lane is determined regardless of whether the other vehicle 55 traveling in the adjacent lane L2 is the preceding vehicle 51 or the following vehicle 52. Therefore, for example, when the distance threshold and the time threshold are set based on the case where the other vehicle 55 is the subsequent vehicle 52, the lane can be obtained even when the other vehicle 55 is the preceding vehicle 51 existing sufficiently away from the own vehicle 50. There is a possibility that the lane change is canceled because the lane change permission determination is made that the change is impossible. As a result, the driver may feel uncomfortable (discomfort that lane change support is canceled too soon). That is, there is a possibility that the lane change possibility determination with a great discomfort for the driver may be performed.

  In this regard, in the lane change assist device 100 of the present embodiment, when the other vehicle 55 is the preceding vehicle 51, when the inter-vehicle distance is equal to or greater than the first distance threshold and the predicted collision time is equal to or greater than the first time threshold. It is determined that the lane change is possible. When the other vehicle 55 is the succeeding vehicle 52, when the inter-vehicle distance is equal to or greater than the second distance threshold greater than the first distance threshold and the predicted collision time is equal to or greater than the second time threshold greater than the first time threshold. It is determined that the lane change is possible. Thereby, for example, the threshold for determination in the lane change enable / disable determination can be switched according to a sense of distance or speed with the other vehicle 55 that differs depending on whether the other vehicle 55 is the preceding vehicle 51 or the following vehicle 52. . As a result, it is possible to determine whether or not the lane change is possible with little discomfort for the driver.

  As mentioned above, although embodiment of this invention was described, this invention is implemented in various forms, without being limited to the said embodiment.

  In the above embodiment, some of the functions of the ECU 10, that is, the external situation recognition unit 11, the vehicle position recognition unit 12, the travel plan generation unit 13, the other vehicle determination unit 14, the lane change intention determination unit 15, and the lane change availability determination. Part of the unit 16 and the traveling control unit 17 may be executed in a computer of a facility such as an information processing center that can communicate with the host vehicle 50.

  In the above embodiment, the inter-vehicle distance between the host vehicle 50 and the other vehicle 55 at the completion of the lane change is used for the lane change determination. For example, the inter-vehicle distance from the start of the lane change to the completion is determined as the lane change determination. It may be used. The inter-vehicle distance from the start to the completion of the lane change is an inter-vehicle distance calculated at each time point during the lane change execution including not only the lane change completion but also the lane change start.

  In the above-described embodiment, the collision prediction time at the start of the lane change is used for the lane change determination. However, for example, the collision prediction time from the start of the lane change to the completion may be used for the lane change determination. The collision prediction time from the start of the lane change to the completion is the collision prediction time calculated at each time point during the lane change execution including not only the lane change start but also the lane change completion.

  In the above embodiment, the inter-vehicle distance between the host vehicle 50 and the other vehicle 55 and the predicted collision time are used for determining whether or not the lane change is possible. For example, the inter-vehicle time between the host vehicle 50 and the other vehicle 55 (THW [Time Headway]). May be further used. The inter-vehicle time is a time obtained by dividing the calculated inter-vehicle distance by the speed of the other vehicle 55.

  In the above embodiment, when the driver of the host vehicle 50 intends to change the lane, the host vehicle 50 is lane-changed from the host lane L1 to the adjacent lane L2. However, for example, in front of the host vehicle 50 in the host lane L1. When a lane change is necessary due to an obstacle or the like, the host vehicle 50 may be lane changed from the own lane L1 to the adjacent lane L2 regardless of whether the driver intends to change the lane.

  As described above, when the other vehicle 55 is the succeeding vehicle 52, the sense of distance and the speed between the host vehicle 50 and the other vehicle 55 due to the difficulty of the driver to visually recognize the other vehicle 55. It is difficult for the driver to grasp the feeling. Therefore, in the above embodiment, for example, a room mirror, a door mirror, and the like may be made into an electronic mirror to widen the field of view. In this case, the driver can easily grasp the sense of distance and speed between the host vehicle 50 and the other vehicle 55.

  DESCRIPTION OF SYMBOLS 2 ... External sensor (peripheral information detection part), 14 ... Other vehicle determination part, 16 ... Lane change permission determination part (lane change permission determination part), 100 ... Lane change assistance apparatus.

Claims (1)

A lane change support device for changing the lane of a host vehicle from its own lane to an adjacent lane
A surrounding information detector for detecting surrounding information of the vehicle;
Based on the peripheral information detected by the peripheral information detection unit, whether the other vehicle traveling in the adjacent lane is a preceding vehicle traveling in front of the host vehicle or a succeeding vehicle traveling behind the host vehicle. An other vehicle determination unit for determining
A lane change enable / disable determining unit that performs a lane change enable / disable determination that determines whether or not the lane of the host vehicle can be changed based on the periphery information detected by the periphery information detection unit and the determination result of the other vehicle determination unit. ,
The lane change permission determination unit
Inter-vehicle distance between the host vehicle and the other vehicle when the lane change is completed, or the inter-vehicle distance from the start to the end of the lane change, and a collision prediction between the host vehicle and the other vehicle at the start of the lane change Calculate the collision prediction time from the start to the completion of time or lane change,
When the other vehicle is the preceding vehicle, it is determined that the lane change is possible when the inter-vehicle distance is greater than or equal to a first distance threshold and the predicted collision time is greater than or equal to a first time threshold;
When the other vehicle is the succeeding vehicle, the inter-vehicle distance is greater than or equal to a second distance threshold greater than the first distance threshold, and the predicted collision time is greater than or equal to a second time threshold greater than the first time threshold. A lane change support device that determines that the lane change is possible.

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