Lane change assist device

Abstract

A control unit 100 comprises: a detection unit 130, which detects the situation in the vicinity of a vehicle; a lane change determination unit 150, which, if the detection unit 130 has detected another vehicle traveling in an adjacent lane, determines whether a lane change is possible based on the relative speeds of the vehicle and the other vehicle and on the distance between the vehicle and the other vehicle; and a driving control unit 170, which is capable of executing the lane change based on the determination result of the lane change determination unit 150. Based on a preset target speed, the driving control unit 170 is also capable of performing speed control to regulate the vehicle's speed.When the vehicle speed control is performed, the lane change determination unit 150 determines, based on the relative speeds, whether a lane change is possible or not, when the vehicle's speed is set to the target speed.

Description

TECHNICAL FIELD

[0001] The present invention relates to a lane change assistance device. TECHNICAL BACKGROUND

[0002] In recent years, active efforts have been made to achieve access to a sustainable transportation system with vulnerable road users in mind. As one of these efforts, research and development have been conducted on driver assistance technologies and automated driving technologies for vehicles such as automobiles to further improve traffic safety and convenience. As an example of the driver assistance technologies, Patent Literature 1 listed below discloses a lane change assist device that causes a host vehicle to perform a lane change from a host lane to an adjacent lane. CITATION LISTPATENT LITERATURE

[0003] Patent Literature 1: JP2017-074 823 A SUMMARY OF THE INVENTION TECHNICAL PROBLEM

[0004] In an existing lane change assistance device, whether a lane change is possible is determined based on the relative speed of a host vehicle with respect to another vehicle according to the current traveling speed of the host vehicle. For example, if the host vehicle is traveling slowly due to the influence of a preceding vehicle or the like, it may be difficult to perform the lane change.

[0005] The present invention provides a lane change assist device capable of increasing an opportunity to perform a lane change. PROBLEM SOLVING

[0006] One aspect of the present invention is a lane change assist device capable of performing a lane change of a host vehicle from a host lane on which the host vehicle is traveling to a lane adjacent to the host lane, the lane change assist device comprising: a detection unit configured to detect an environmental situation of the host vehicle; a lane change determination unit configured to determine, when another vehicle traveling in the adjacent lane is detected by the detection unit, whether the lane change is possible based on a relative speed between the host vehicle and the other vehicle and an inter-vehicle distance between the host vehicle and the other vehicle;and a driving control unit configured to execute the lane change based on a determination result of the lane change determining unit, wherein the driving control unit is configured to further execute a traveling speed control for controlling a traveling speed of the host vehicle based on a preset target speed, and the lane change determining unit is configured to, when the target speed is the traveling speed of the host vehicle while the traveling speed control is being executed, determine whether the lane change is possible based on the relative speed. ADVANTAGEOUS EFFECTS OF THE INVENTION

[0007] According to the present invention, it is possible to provide a lane change assist device capable of increasing an opportunity to perform a lane change. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram showing an overall configuration of a vehicle system 1 to which a control device 100 according to an embodiment is mounted; Fig. 2 is a diagram showing an example of a configuration of a first control unit 120 and a second control unit 160; Fig. 3 is a diagram showing an example of a steering wheel 82 and a turn signal lever 81; Fig. 4 is a diagram showing a specific example of operation of the turn signal lever 81; Fig. 5 is a diagram showing an example of a lane change operation of a host vehicle M by the controller 100 during the execution of ACC; Fig. 6 is a diagram showing an example of a minimum inter-vehicle distance at which a lane change can be performed for each relative speed; Fig. 7 is a diagram showing an example of a minimum inter-vehicle distance d1 at which the lane change is executable when a relative speed between the host vehicle M and a following vehicle M2 is ΔV1, and a minimum inter-vehicle distance d2 at which the lane change is executable when the relative speed between the host vehicle M and the following vehicle M2 is ΔV2; Fig. 8 is a flowchart (part 1) showing an example of a lane change assistance process executed by the control unit 100; Fig. 9 is a flowchart (part 2) showing an example of the lane change assistance process executed by the control unit 100; Fig. 10 is a flowchart (part 1) showing an example of the lane change possibility determination process executed by the control unit 100; Fig. 11 is a flowchart (part 2) showing an example of the lane change possibility determination process executed by the control unit 100; and Fig. 12 is a flowchart showing an example of a lane change stop determination process executed by the controller 100. DESCRIPTION OF VERSIONS

[0008] An embodiment of a lane change assist device according to the present invention will be described below with reference to the drawings. Hereinafter, the same or similar elements are denoted by the same or similar reference numerals, and their descriptions may be omitted or simplified as necessary. <Gesamtkonfiguration des Fahrzeugsystems 1>

[0009] Fig. 1 is a block diagram showing an overall configuration of a vehicle system 1 to which a control unit 100 is mounted, which is an embodiment of a lane change assist device according to the present invention. A vehicle to which the vehicle system 1 is mounted (hereinafter referred to as a "host vehicle M") is a vehicle such as a two-wheeled vehicle, a three-wheeled vehicle, or a four-wheeled vehicle, and its drive source is an internal combustion engine such as a diesel engine or a gasoline engine, an electric motor, or a combination thereof. The electric motor operates using electric power generated by an electric generator connected to the engine, or electric power output from a secondary battery or a fuel cell.

[0010] The vehicle system 1 includes, for example, a camera 10, a radar device 12, a light detection and scanning device (LIDAR) 14, an object recognition device 16, a communication device 20, a human-machine interface (HMI) 30, a vehicle sensor 40, a driver monitor camera 50, a navigation device 60, a map positioning unit (MPU) 70, a driving control element 80, a turn signal 83, the control device 100, a driving force device 200, a braking device 210, and a steering device 220. These devices and devices are connected to each other via, for example, a multiplexed communication line such as a controller area network (CAN) communication line, a serial communication line, or a wireless communication network.

[0011] The camera 10 is, for example, a digital camera that uses a solid-state imaging device such as a charge-coupled device (CCD) or a complementary metal oxide semiconductor (CMOS). The camera 10 is mounted on any portion of the host vehicle M to which the vehicle system 1 is mounted.

[0012] The radar device 12 emits radio waves such as millimeter waves to the surroundings of the host vehicle M and detects radio waves reflected from an object (reflected waves) to detect at least a position (distance and orientation) of the object. The radar device 12 is mounted on any portion of the host vehicle M.

[0013] The LIDAR 14 emits light (or an electromagnetic wave with a wavelength close to that of light) toward the surroundings of the host vehicle M and measures scattered light. The LIDAR 14 detects a distance to a target based on the time elapsed from the light transmission to the light reception. The emitted light is, for example, pulsed laser light. The LIDAR 14 is mounted on any portion of the host vehicle M.

[0014] The object detection device 16 performs a sensor fusion process on some or all of the detection results from the camera 10, the radar 12, and the LIDAR 14 to detect a position, type, speed, and the like of an object. The object detection device 16 outputs a detection result to the control device 100. The object detection device 16 can output the detection results from the camera 10, the radar 12, and the LIDAR 14 to the control device 100 without modification.

[0015] The communication device 20 uses, for example, a cellular network, a Wi-Fi (registered trademark) network, Bluetooth (registered trademark), or dedicated short-range communication (DSRC) to communicate with other vehicles located in the vicinity of the host vehicle M or to communicate with various server devices via a radio base station.

[0016] The HMI 30 presents various information to an occupant of the host vehicle M and receives an input operation performed by the occupant. The HMI 30 includes various display devices, a speaker, a buzzer, a touch panel, a switch, a button, and the like.

[0017] The vehicle sensor 40 includes a vehicle speed sensor that detects a traveling speed (so-called “vehicle speed”; hereinafter simply referred to as “speed”) of the host vehicle M, an acceleration sensor that detects acceleration, a yaw rate sensor that detects an angular velocity around a vertical axis, an azimuth sensor that detects an orientation of the host vehicle M, and the like.

[0018] The driver monitor camera 50 is, for example, a digital camera using a solid-state imaging device such as a CCD or a CMOS. The driver monitor camera 50 is mounted on any portion of the host vehicle M in a position and orientation in which an image of the head of an occupant (hereinafter also referred to as a "driver") sitting in a driver's seat of the host vehicle M can be captured from the front (ie, in an orientation in which an image of a face is captured).

[0019] The navigation device 60 includes, for example, a global navigation satellite system (GNSS) receiver 61, a navigation HMI 62, and a route determination unit 63. The navigation device 60 stores first map information 64 in a storage device such as a hard disk drive (HDD) or a flash memory.

[0020] The GNSS receiver 61 specifies a position of the host vehicle M based on a signal received from a GNSS satellite. The position of the host vehicle M can be specified or supplemented by an inertial navigation system (INS) using an output of the vehicle sensor 40.

[0021] The navigation HMI 62 includes a display, a speaker, a touch panel, a button, and the like. The navigation HMI 62 can be partially or completely shared with the HMI 30 described above.

[0022] For example, with respect to the first map information 64, the route determination unit 63 determines a route (hereinafter also referred to as a "map route") from the position of the host vehicle M specified by the GNSS receiver (or any position input) to a destination input by the occupant using the navigation HMI 62. The first map information 64 is, for example, information in which a road shape is indicated by a link indicating a road and nodes connected by the link. The first map information 64 may include a curvature of a road, information on a point of interest (POI), and the like. The map route is output to the MPU 70.

[0023] The navigation device 60 can execute route guidance using the navigation HMI 62 based on the map route. The navigation device 60 can send a current position and destination to a navigation server via the communication device 20 and acquire a route equivalent to the map route from the navigation server.

[0024] The MPU 70 includes, for example, a recommended lane determination unit 71 and stores second map information 72 in a storage device such as an HDD or a flash memory. The recommended lane determination unit 71 divides the map route provided by the navigation device 60 into multiple blocks (for example, divides the map route in the vehicle's travel direction by 100 [m]) and determines a recommended lane for each block with reference to the second map information 72. For example, the recommended lane determination unit 71 determines which lane from the left the vehicle should enter. When there is a branch point on the map route, the recommended lane determination unit 71 determines a recommended lane so that the host vehicle M can travel along a reasonable route to reach a branching destination.

[0025] The second map information 72 is map information with higher accuracy than the first map information 64. The second map information 72 contains, for example, information about the center of a lane or information about a lane boundary. The second map information 72 may contain road information, traffic regulation information, address information, building information, telephone number information, and the like. The second map information 72 may be updated as needed by the communication device 20 communicating with another device.

[0026] The driving operation member 80 includes, for example, an accelerator pedal, a brake pedal, a shift lever, and other operating members, in addition to a turn signal lever 81 and a steering wheel 82. A sensor that detects an operation amount or the presence or absence of an operation is attached to the driving operation member 80, and a detection result thereof is output to some or all of the controller 100, the driving drive force output device 200, the braking device 210, and the steering device 220.

[0027] The turn signal lever 81 is an operating element for turning the turn signal 83 on or off and also functions as an operating element for receiving a lane change request. As described in detail later, the control unit 100 detects the lane change request from the driver based on a predetermined operation of the turn signal lever 81 performed by the driver.

[0028] The turn signal 83 is a direction indicator provided on each of the left side (e.g., left front and left rear) and right side (e.g., right front and right rear) of the host vehicle M and mounted at a position visible from the outside of the host vehicle M. The control unit 100 turns the turn signal 83 on (including blinking) or off according to an operation of the turn signal lever 81.

[0029] The steering wheel 82 is an operating element for receiving a steering operation. The steering wheel 82 is not necessarily ring-shaped and may be in the form of a deformed steering wheel, a joystick, a knob, or the like. A steering grip sensor 84 is attached to the steering wheel 82. The steering grip sensor 84 is implemented by a static capacitance sensor or the like and outputs a signal to the control unit 100 that can detect whether the driver is gripping the steering wheel 82.

[0030] The control device 100 is a computer that integrally controls the entire host vehicle M and includes, for example, a first control unit 120 and a second control unit 160. Each of the first control unit 120 and the second control unit 160 is implemented, for example, by a hardware processor such as a central processing unit (CPU) that executes a program (software). Some or all of these components may be implemented by hardware (including a circuit) such as a large-scale integration (LSI), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), and a graphics processing unit (GPU), or may be implemented through cooperation of software and hardware. The program may be pre-stored in a storage device such as an HDD or a flash memory of the control device 100. <Konfiguration der ersten Steuereinheit 120 und der zweiten Steuereinheit 160>

[0031] Fig. 2 is a diagram showing an example of a configuration of the first control unit 120 and the second control unit 160. The first control unit 120 includes, for example, a recognition unit 130 and an action plan generation unit 140. The first control unit 120 implements, for example, a function based on artificial intelligence (AI) and a function based on a predefined model in parallel.

[0032] For example, a function of "intersection point detection" can be implemented by parallelly performing intersection point detection using deep learning or the like and detection based on a predefined condition (permit signal pattern matching, road marking, or the like), and performing in-depth evaluation by scoring the two detections. Accordingly, the reliability of automated driving is ensured.

[0033] The detection unit 130 detects an environmental situation of the host vehicle M based on information input via the object detection device 16 from the camera 10, the radar device 12, and the LIDAR 14. Specifically, the detection unit 130 detects a position of an object in the surroundings of the host vehicle M, as well as a driving state including the object's speed, acceleration, and the like. For example, the position of the object is detected as a position on absolute coordinates with a representative point (the center of gravity, drive shaft center, or the like) of the host vehicle M as the origin, and used for control. The position of the object may be represented by a representative point such as a center of gravity or a corner of the object, or may be represented by a region.A "state" of the object may be an acceleration or jerk of the object, or an "action state" (e.g., whether the object is changing lanes or whether the object is about to change lanes). The object detected by the detection unit 130 includes another vehicle (hereinafter also referred to as a "leading vehicle") M1 traveling in front of the host vehicle M, and another vehicle (hereinafter also referred to as a "following vehicle") M2 traveling behind the host vehicle M.

[0034] For example, the recognition unit 130 recognizes a driving environment in which the host vehicle M is traveling. For example, the recognition unit 130 recognizes a driving lane of the host vehicle M by comparing a pattern of road dividing lines (for example, a series of solid lines and broken lines) obtained from the second map information 72 with a pattern of road dividing lines in the surroundings of the host vehicle M, which is recognized from an image captured by the camera 10. The recognition unit 130 can recognize the driving lane by recognizing not only the road dividing lines but also a course boundary (road boundary) including a road dividing line, a road shoulder, a curb, a median, a guardrail, and the like. In the recognition, the position of the host vehicle M detected by the navigation device 60 or a process result of the INS may be added.The detection unit 130 can detect a temporary stop line, an obstacle, a red signal, a toll barrier and other road events.

[0035] When the lane is detected, the detection unit 130 detects a position and posture of the host vehicle M with respect to the lane. For example, the detection unit 130 may detect a deviation of a reference point of the host vehicle M from a lane center and an angle of a traveling direction of the host vehicle M with respect to a line connecting the lane center as the relative position and posture of the host vehicle M with respect to the lane. Alternatively, the detection unit 130 may detect a position of the reference point of the host vehicle M with respect to any side end portion (a road dividing line or road boundary) of the lane as the relative position of the host vehicle M with respect to the lane.

[0036] The action plan generation unit 140 generates a target trajectory in which the host vehicle M essentially travels in a recommended lane determined by the recommended lane determination unit 71 and will continue to travel automatically in the future (regardless of any driver operation) so as to correspond to the environmental situation of the host vehicle M. The target trajectory includes, for example, a speed element. For example, the target trajectory is represented by arranging points (trajectory points) to be reached by the host vehicle M in sequence. The trajectory point is a point to be reached by the host vehicle M for every predetermined travel distance (for example, about a few meters) in a road distance, and a target speed and a target acceleration are separately generated for every predetermined sampling time (for example, a few fractions of a second) as part of the target trajectory.The trajectory point may be a position to be reached by the host vehicle M at a sampling time within each predetermined sampling time. In this case, information about the target speed and the target acceleration is expressed by an interval of the trajectory points.

[0037] The action plan generation unit 140 can set an automated driving event when generating the target trajectory. The automated driving event includes a constant-speed driving event, a slow-speed following driving event, a lane change event, a turn-off event, a junction event, an overtaking event, and the like. The action plan generation unit 140 generates the target trajectory according to an activated event.

[0038] As an example, the action plan generation unit 140 includes a lane change determination unit 150 that determines whether a lane change is possible based on a driving environment of the host vehicle M detected by the detection unit 130. For example, if another vehicle is detected traveling in a lane adjacent to the lane of the host vehicle M, the lane change determination unit 150 determines whether the lane change is possible based on a relative speed and an inter-vehicle distance between the host vehicle M and the other vehicle.

[0039] Then, the action plan generation unit 140 sets a lane change event or generates a target trajectory according to the lane change event based on the lane change determination unit 150 determining that the lane change is possible. Thus, a driving control unit 170, described later, is configured to be able to execute the lane change based on the determination result of the lane change determination unit 150. The specific content of the determination by the control device 100 as to whether the lane change is possible, which is implemented by the lane change determination unit 150 or the like, will be described later, and therefore, it will be omitted from the description here.

[0040] The second control unit 160 controls the host vehicle M so that it traverses the target trajectory generated by the action plan generation unit 140 at a scheduled time. The second control unit 160 includes, for example, a detection unit 162, a speed control unit 164, and a steering control unit 166.

[0041] The acquisition unit 162 acquires information about the target trajectory (trajectory points) generated by the action plan generation unit 140 and stores the information in a memory (not shown). The speed control unit 164 controls the driving force output device 200 (see Fig. 1) or the braking device 210 (see Fig. 1) based on the speed element, accompanied by the desired trajectory stored in memory. The steering control unit 166 controls the steering device 220 (see Fig. 1) according to the degree of curvature of the target trajectory stored in memory. The process of the speed control unit 164 and the steering control unit 166 is implemented, for example, by a combination of feedforward control and feedback control.

[0042] The second control unit 160 further includes, for example, a notification control unit 167. The notification control unit 167 controls the HMI 30, the navigation HMI 62, and the like to output various messages (presentation of various information) to the occupant (e.g., the driver) of the host vehicle M. For example, when the control device 100 stops the lane change, the notification control unit 167 outputs a message indicating that the lane change is stopped (for example, see step S40 in Fig. 12). The message indicating that the lane change is stopped is output, for example, by displaying a message "the lane change is stopped" on the display device of the HMI 30, the navigation HMI 62, or the like. <Fahrsteuereinheit 170>

[0043] In the control device 100, for example, a combination of the action plan generation unit 140 (including the lane change determination unit 150) of the first control unit 120, and the detection unit 162, the speed control unit 164, and the steering control unit 166 of the second control unit 160 constitutes the driving control unit 170.

[0044] When a driver's lane change request is detected based on the driver's operation of the driving control member 80 (for example, the turn signal lever 81), the driving control unit 170 executes control regarding the lane change of the host vehicle M based on a detection result of a driving state, a driving environment, or the like of the host vehicle M detected by the detection unit 130. For example, when the driver's lane change request is detected, the driving control unit 170 determines whether the lane change is possible, taking into account the driving states or the like of the host vehicle M and other vehicles around the host vehicle M, and starts the lane change if it is determined that the lane change is possible.The lane change executed by the control unit 100 in accordance with an instruction (lane change request) from the driver in this manner is hereinafter referred to as “intentional automatic lane change.”

[0045] The traveling control unit 170 is configured to be capable of executing traveling speed control for controlling the traveling speed of the host vehicle M based on a target speed set in advance by the driver, a manufacturer of the host vehicle M, or the like. Here, the traveling speed control is such a control that the traveling speed of the host vehicle M is set to the target speed when there is no preceding vehicle M1 in a traveling lane of the host vehicle M (host lane L1 described later), and the traveling speed of the host vehicle M is set according to a traveling speed of the preceding vehicle M1 when there is the preceding vehicle M1 in the traveling lane of the host vehicle M.For example, when the preceding vehicle M1 is located in the traveling lane of the host vehicle M during execution of the traveling speed control, the traveling control unit 170 causes the host vehicle M to travel such that the traveling speed of the host vehicle M is the target speed, under a condition that an appropriate inter-vehicle distance between the host vehicle M and the preceding vehicle M1 can be ensured. When the preceding vehicle M1 traveling at a speed lower than the target speed is located in the traveling lane of the host vehicle M during execution of the traveling speed control, the host vehicle M can travel at substantially the same speed as the preceding vehicle M1 (that is, at a speed lower than the target speed) after the inter-vehicle distance to the preceding vehicle M1 reaches a predetermined distance.

[0046] This vehicle speed control is generally referred to as "adaptive cruise control (ACC)." In the present embodiment, the vehicle speed control is hereinafter also referred to as "ACC." By executing the ACC (i.e., vehicle speed control) by the travel control unit 170, the controller 100 can appropriately control the vehicle speed of the host vehicle M taking into account the presence or absence of the preceding vehicle M1 in the travel lane of the host vehicle M (the host lane L1 described later) and its travel speed, and can reduce fatigue of the driver of the host vehicle M or the like while ensuring the safety of the host vehicle M.

[0047] Again in relation to Fig. 1, the driving force output device 200 outputs driving force (torque) to the drive wheels for driving the vehicle. The driving force output device 200 includes, for example, a combination of an internal combustion engine, an electric motor, a transmission, and the like, and an electronic control unit (ECU) configured to control the same. The ECU controls the above configuration according to information received from the second control unit 160 or information received from the driving control element 80.

[0048] The braking device 210 includes, for example, a brake caliper, a cylinder that transmits hydraulic pressure to the caliper, an electric motor that generates hydraulic pressure in the cylinder, and a brake ECU. The brake ECU controls the electric motor according to the information received from the second control unit 160 or the information received from the driving control element 80 and outputs a braking torque to each wheel according to a braking operation.

[0049] The steering device 220 includes, for example, a steering ECU and an electric motor. The electric motor changes the orientation of a steering wheel, for example, by applying a force to a rack and pinion mechanism. The steering ECU drives the electric motor according to the braking action information received from the second control unit 160 or the driving control element 80 to change the orientation of the steering wheel. <Lenkrad 82 und Blinkerhebel 81>

[0050] Fig. 3 is a diagram showing an example of the steering wheel 82 and the turn signal lever 81. As in Fig. 3, the turn signal lever 81 is, for example, an operating member provided at a position and in a shape that allows the driver to blindly operate it with a grasping hand (for example, a finger of the right hand) while the driver grasps the steering wheel 82. <Bedienung des Blinkerhebels 81>

[0051] Fig. 4 is a diagram showing a specific operation example of the turn signal lever 81. As shown in Fig. As shown in Figure 4, the turn signal lever 81 is pivotable about a pivot axis 81a. A neutral position PN, light pressure positions P1L and P1R, and deep pressure positions P2L and P2R are positions in which the turn signal lever 81 can be displaced by pivoting.

[0052] The neutral position PN is a position in which the turn signal lever 81 is not operated, and when the turn signal lever 81 is in the neutral position PN, the turn signal 83 is turned off.

[0053] The light pressure position P1L is a halfway position pivoted counterclockwise by a predetermined amount from the neutral position PN. The deep pressure position P2L is an end position pivoted further counterclockwise by a predetermined amount from the light pressure position P1L. The light pressure position P1R is a halfway position pivoted clockwise by a predetermined amount from the neutral position PN. The deep pressure position P2R is an end position pivoted further clockwise by a predetermined amount from the light pressure position P1R. The light pressure positions P1L and P1R are examples of a first position of the turn signal lever 81. The deep pressure positions P2L and P2R are examples of a second position of the turn signal lever 81.

[0054] When the turn signal lever 81 is pushed by the driver to the light push position P1L or P1R, a click feeling is given to the driver. From this state, when an operating force on the turn signal lever 81 is released, the turn signal lever 81 mechanically returns to the neutral position PN by a return mechanism (not shown) such as a spring. When the turn signal lever 81 is pushed by the driver to the deep push position P2L or P2R, the turn signal lever 81 is held at the deep push position P2L or P2R by a mechanical lock mechanism (not shown) even when the operating force is released.

[0055] The turn signal lever 81 is provided with a switch (not shown). The travel control unit 170 can determine whether the turn signal lever 81 is at the neutral position PN, the light pressure position P1L or P1R, or the deep pressure position P2L or P2R based on a detection result by the switch.

[0056] When the steering wheel 82 is turned back in a state where the turn signal lever 81 is held at the deep push position P2L or P2R, and the turn signal lever 81 returns to the neutral position, or when the driver returns the turn signal lever 81 in a neutral position direction, the lock by the locking mechanism is released, and the turn signal lever 81 returns to the neutral position PN. That is, when the turn signal lever 81 is operated to the deep push position P2L or P2R, the turn signal lever 81 operates in the same manner as a turn signal device generally known in the related art.

[0057] Hereinafter, an operation of holding the turn signal lever 81 at the light pressure position P1L or the light pressure position P1R is referred to as a "half-lock operation." The half-lock operation is an example of the predetermined operation according to the present invention. For example, the control device 100 determines that a lane change request exists when the half-lock operation of the turn signal lever 81 continues for a predetermined time or longer. Here, the predetermined time is the time required to confirm the driver's intention to execute the lane change, and is, for example, 1.0 [sec]. In this way, by receiving the lane change request based on an operation (e.g., half-lock operation) from the turn signal lever 81, it is possible to receive the lane change request without providing an operation button or the like for receiving the lane change request separately from the turn signal lever 81. <Fahrspurwechselbetrieb des Host-Fahrzeugs M>

[0058] If there is a lane change request from the driver during the execution of the ACC, the control device 100 (for example, the driving control unit 170) may execute the lane change while maintaining the ACC. Fig. 5 shows an example of a lane change operation of the host vehicle M by the control unit 100 during the execution of the ACC.

[0059] One in Fig. The road 110 shown in Figure 5 has a right lane 111 and a left lane 112 in which a direction from a bottom to a top in Fig. 5 is a direction of travel. A dividing line C as a road dividing line lies at a boundary between the right lane 111 and the left lane 112.

[0060] In the Fig. In the example shown in Figure 5, the host vehicle M travels in the right lane 111 of the road 110 under the ACC. Hereinafter, the lane of the host vehicle M is also referred to as the "host lane L1." The preceding vehicle M1, which is traveling slower than the target speed of the host vehicle M, is located in the right lane 111, which is the host lane L1. The following vehicle M2, which is traveling, is located in the left lane 112 adjacent to the right lane 111, which is the host lane L1. Hereinafter, the lane adjacent to the host lane L1 is also referred to as the "adjacent lane L2."

[0061] If, in the case of Fig. In the example shown in Figure 5, when the host vehicle M maintains the right lane 111, the host vehicle M must continue to travel at a lower speed than the target speed due to the influence of the preceding vehicle M1, and therefore the driver frequently desires to perform the lane change. In the example described here, it is also assumed that the driver desires to perform the lane change and issues a lane change request (for example, the above half-lock operation) to the control unit 100.

[0062] In this way, if there is a lane change request from the driver while the ACC is being executed and the host vehicle M is traveling at a speed lower than the target speed, the control unit 100 first starts turning on the turn signal 83 and accelerates the host vehicle M in the right lane 111 (host lane L1). That is, when the lane change is being executed during the execution of the ACC (i.e., vehicle speed control), the control unit 100 (for example, the traveling control unit 170) accelerates the host vehicle M based on the target speed before the movement to the adjacent lane L2 is completed by the lane change. Accordingly, it is possible to execute the lane change while ensuring the safety of the host vehicle M by preventing an inter-vehicle distance to the following vehicle M2 traveling in the adjacent lane L2 from being shortened.

[0063] Then, after a time t1 from the start of acceleration, the control unit 100 executes the lane change by further accelerating the host vehicle M and moving the host vehicle M laterally toward the left lane 112 (adjacent lane L2). Specifically, when the lane change is performed during the execution of the ACC (i.e., vehicle speed control), the control unit 100 (e.g., the vehicle control unit 170) accelerates the host vehicle M to the target speed before completing the movement to the adjacent lane L2 by the lane change.

[0064] As an example, in the present embodiment, the time t1 from the start of acceleration to the start of lateral movement on the host lane L1 is set to 3 [sec]. A time t2 from the start of lateral movement to the completion of lateral movement (ie, completion of lane change) is set to 7 [sec]. That is, the control unit 100 executes the lane change in 10 [sec] from the time the turn signal 83 is turned on according to the lane change request.

[0065] If a lane change request is received from the driver while the ACC is running and the host vehicle M is traveling at a speed lower than the target speed, the control unit 100 executes the lane change while accelerating the host vehicle M at a constant acceleration, and causes the host vehicle M to reach the target speed when the lane change is completed. For example, if the lane change is executed in 10 [sec] as described above, the acceleration of the host vehicle M at the time of the lane change is (target speed - speed immediately before the start of the lane change) / 10 [km / s]. 2 ].

[0066] In this case, if the lane change is executed while the ACC is running and the host vehicle M is traveling at a speed lower than the target speed, the host vehicle M will accelerate to the target speed before the movement to the adjacent lane L2 is completed by the lane change. Accordingly, it is possible to execute the lane change while ensuring the safety of the host vehicle M by preventing the inter-vehicle distance to the following vehicle M2 traveling in the adjacent lane L2 from being shortened.If the host vehicle M is accelerated according to the execution of the lane change in this way by making the acceleration constant, the occurrence of an acceleration fluctuation expected by the driver when changing lanes is prevented, and it becomes possible to execute the lane change while avoiding the driver from feeling burdened or uncomfortable. <fahrspurwechsel-bestimmungsprozess>

[0067] If, as in Fig. 5, the following vehicle M2 is traveling on the adjacent lane L2 when the lane change request is there, the lane change determination unit 150 determines whether lane change is possible based on a relative speed between the host vehicle M and the following vehicle M2 and the inter-vehicle distance between the host vehicle M and the following vehicle M2.

[0068] In particular, in the present embodiment, as in Fig. 6, a minimum inter-vehicle distance at which the lane change is executable is set in advance for each relative speed. The lane change determining unit 150 first calculates the relative speed between the host vehicle M and the following vehicle M2 by subtracting a speed of the host vehicle M from a speed of the following vehicle M2, and compares a minimum inter-vehicle distance corresponding to the calculated relative speed with the inter-vehicle distance between the host vehicle M and the following vehicle M2. As a result, the lane change determining unit 150 determines that the lane change is possible when the inter-vehicle distance between the host vehicle M and the following vehicle M2 is equal to or greater than the minimum inter-vehicle distance corresponding to the relative speed between the host vehicle M and the following vehicle M2.On the other hand, when the inter-vehicle distance between the host vehicle M and the following vehicle M2 is smaller than the minimum inter-vehicle distance corresponding to the relative speed between the host vehicle M and the following vehicle M2, the lane change determining unit 150 determines that the lane change is impossible.

[0069] For example, in the present embodiment, if the relative speed between the host vehicle M and the following vehicle M2 is ΔV1, then the minimum inter-vehicle distance at which the lane change is executable is d1. Therefore, if the following vehicle M2 is traveling in the adjacent lane L2, when there is a lane change request and the relative speed between the host vehicle M and the following vehicle M2 is ΔV1, the lane change determination unit 150 determines that the lane change is possible when the inter-vehicle distance between the host vehicle M and the following vehicle M2 is d1 or more.

[0070] Therefore, if in the present embodiment, as in (a) in Fig. 7, the relative speed between the host vehicle M and the following vehicle M2 is ΔV1 and the inter-vehicle distance between the host vehicle M and the following vehicle M2 is d1 or more, the control device 100 (for example, the travel control unit 170) executes the lane change to the adjacent lane L2 according to the lane change request.

[0071] As another example, in the present embodiment, when the relative speed between the host vehicle M and the following vehicle M2 is ΔV2 (where ΔV2 < ΔV1), the minimum inter-vehicle distance at which the lane change is executable is d2 (where d2 < d1). Therefore, if the following vehicle M2 is traveling in the adjacent lane L2, when there is a lane change request and the relative speed between the host vehicle M and the following vehicle M2 is ΔV2, the lane change determination unit 150 determines that the lane change is possible when the inter-vehicle distance between the host vehicle M and the following vehicle M2 is d2 or more.

[0072] Therefore, in the present embodiment, as in (b) in Fig. 7, if the relative speed between the host vehicle M and the following vehicle M2 is ΔV2 and the inter-vehicle distance between the host vehicle M and the following vehicle M2 is d2 or more, the control device 100 (for example, the travel control unit 170) executes the lane change to the adjacent lane L2 according to the lane change request.

[0073] In this way, in the present embodiment, when the relative speed between the host vehicle M and the following vehicle M2 is smaller, the inter-vehicle distance condition for determining whether the lane change is possible is more relaxed. Thus, when the relative speed between the host vehicle M and the following vehicle M2 is small, and the inter-vehicle distance between the host vehicle M and the following vehicle M2 is less likely to be reduced at the time of the lane change (that is, when there is a small possibility that the host vehicle M will be harassed by the following vehicle M2), it is possible to facilitate the execution of the lane change according to the driver's lane change request.

[0074] On the other hand, in the above configuration, if the relative speed between the host vehicle M and the following vehicle M2 is high, it may be difficult to execute the lane change even if the driver issues a lane change request. For example, as described above, if the preceding vehicle M1 is traveling at a lower speed in front of the host vehicle M executing the ACC, the host vehicle M may also travel at a low speed under the influence of the preceding vehicle M1. In this case, the relative speed between the host vehicle M and the following vehicle M2 becomes high, and it may be difficult to execute the lane change even if the driver issues a lane change request.From the point of view of the marketability of the host vehicle M, as long as the safety of the host vehicle M is ensured, it is desirable to carry out the lane change requested by the driver as far as possible.

[0075] Therefore, while the vehicle speed control (i.e., the ACC) is being executed, the lane change determination unit 150 determines whether the lane change is possible based on a relative speed with another vehicle (for example, the following vehicle M2 traveling in the adjacent lane L2, which is a lane change target) in a case where the vehicle speed of the host vehicle M is the target speed. Accordingly, by considering the acceleration based on the target speed that is possible due to the lane change, it is appropriately determined whether the lane change is possible, and it becomes possible to increase an opportunity to execute the lane change while ensuring the safety of the host vehicle M.

[0076] For example, assume that a lane change request occurs when the ACC is executed with the target speed set to 100 km / h, and the host vehicle M is traveling at 85 km / h. At this time, assume that the following vehicle M2 traveling at 115 km / h is located in the adjacent lane L2, which is the lane change target. In this situation, if a current speed of the host vehicle M (i.e., 85 km / h) is used to calculate the relative speed between the host vehicle M and the following vehicle M2, the relative speed between the host vehicle M and the following vehicle M2 is 30 km / h.

[0077] On the other hand, when the target speed (i.e., 100 [km / h]) is used to calculate the relative speed between the host vehicle M and the following vehicle M2, the relative speed between the host vehicle M and the following vehicle M2 is 15 [km / h]. Therefore, by using the target speed in calculating the relative speed between the host vehicle M and the following vehicle M2, the calculated relative speed can be made smaller than when the current speed of the host vehicle M is used, and it becomes possible to easily perform the lane change even when the inter-vehicle distance between the host vehicle M and the following vehicle M2 is short.

[0078] In this way, if a lane change request is received from the driver while the ACC is being executed and the host vehicle M is traveling at a speed lower than the target speed, the lane change determination unit 150 calculates a relative speed to another vehicle based on the target speed in the ACC and determines whether the lane change is possible. Accordingly, even if the host vehicle M is traveling at a low speed in the host lane L1 under the influence of the preceding vehicle M1 or the like, the control device 100 can appropriately determine whether the lane change is possible by taking into account the acceleration based on the target speed that can be performed after the lane change, and it becomes possible to increase an opportunity to execute the lane change while ensuring the safety of the host vehicle M.Therefore, the marketability of the host vehicle M can be improved. <Vom Steuergerät 100 ausgeführter Prozess>

[0079] The following is a specific example of a process executed by the control unit 100 with respect to the Fig. 8 to 12. For example, when an ignition power supply of the host vehicle M is switched on, the control unit 100 executes the Fig. 8 and Fig. 9 repeatedly executes the lane change assistance process in a predetermined cycle.

[0080] As in Fig. As shown in Figure 8, the controller 100 first determines whether a lane change flag indicating a lane change to be executed by the controller 100 is ON (step S1). If it is determined that the lane change flag is ON (step S1: Yes), the controller 100 proceeds to a process of step S10 described later. On the other hand, if it is determined that the lane change flag is OFF (step S1: No), the controller 100 determines whether there is a lane change request from the driver (step S2).

[0081] If it is determined that there is no lane change request (step S2: No), the controller 100 ends the current lane change assistance process as it is. On the other hand, if it is determined that there is a lane change request (step S2: Yes), the controller 100 proceeds to a lane change possibility determination process (step S3) to determine whether the lane change is possible.

[0082] As in Fig. As shown in Figure 10, in the lane change possibility determination process (step S3), the controller 100 first determines whether the following vehicle M2 is located in the adjacent lane L2, which is the lane change target (step S18). If it is determined that the following vehicle M2 is located in the adjacent lane L2, which is the lane change target (step S18: Yes), the controller 100 determines whether the ACC is currently being executed (step S19).

[0083] If it is determined that the ACC is currently being executed (step S19: Yes), the controller 100 determines whether a current speed of the host vehicle M is less than the target speed (step S20). If it is determined that the current speed of the host vehicle M is less than the target speed (step S20: Yes), the controller 100 determines whether a speed difference between the current speed of the host vehicle M and the target speed is less than a predetermined threshold (step S21). The threshold is set for the controller 100 in advance, for example, by a manufacturer of the host vehicle M.

[0084] If it is determined that the speed difference between the current speed of the host vehicle M and the target speed is smaller than the threshold (step S21: Yes), the controller 100 determines whether the preceding vehicle M1 that prohibits acceleration based on the target speed of the host vehicle M is not located in the host lane L1 or the adjacent lane L2 (step S22). Examples of the preceding vehicle M1 that prohibits acceleration based on the target speed of the host vehicle M include the inter-vehicle distance between the preceding vehicle M1 and the host vehicle M being equal to or smaller than a predetermined value.The preceding vehicle M1 that prohibits the acceleration based on the target speed of the host vehicle M may be the preceding vehicle M1 or the like whose inter-vehicle distance to the host vehicle M is equal to or less than the predetermined value and whose relative speed, when the target speed is a traveling speed of the host vehicle M, is equal to or less than a predetermined value (for example, a negative value).

[0085] If it is determined that the preceding vehicle M1 preventing the acceleration of the host vehicle M is not located in either the host lane L1 or the adjacent lane L2 (step S22: Yes), the controller 100 calculates a relative speed between the host vehicle M and the following vehicle M2 based on the target speed (step S24). That is, in this case, the controller 100 calculates the relative speed to the following vehicle M2 when the target speed is the traveling speed of the host vehicle M.

[0086] On the other hand, when it is determined in a process of step S19 that the ACC is not currently being executed (step S19: No), when it is determined in the process of step S20 that the current speed of the host vehicle M is equal to or greater than the target speed (step S20: No), when it is determined in the process of step S21 that the speed difference between the current speed of the host vehicle M and the target speed is equal to or greater than the threshold value (step S21: No), or when it is determined in the process of step S22 that the preceding vehicle M1 that prevents the acceleration of the host vehicle M is located in the host lane L1 or the adjacent lane L2 100 (step S22: No), the controller calculates a relative speed between the host vehicle M and the following vehicle M2 based on the current speed of the host vehicle M (step S23).

[0087] Then, the controller 100 calculates an inter-vehicle distance between the host vehicle M and the following vehicle M2 (step S25) and determines whether the inter-vehicle distance is equal to or greater than a minimum inter-vehicle distance according to the relative speed calculated in step S23 or step S24 (step S26).

[0088] If it is determined that the inter-vehicle distance between the host vehicle M and the following vehicle M2 is equal to or greater than the minimum inter-vehicle distance (step S26: Yes), the controller 100 determines that the lane change is possible (step S27) and ends the lane change possibility determination process. On the other hand, if it is determined that the inter-vehicle distance between the host vehicle M and the following vehicle M2 is less than the minimum inter-vehicle distance (step S26: No), the controller 100 determines that the lane change is impossible (step S28) and ends the lane change possibility determination process.

[0089] As described above, when the following vehicle M2 is located on the adjacent lane L2, which is the lane change target (step S18: Yes), and when the preceding vehicle M1, which prohibits acceleration based on the target speed of the host vehicle M, is located on the adjacent lane L2 (step S22: No), the control device 100 (for example, the lane change determination unit 150) determines whether the lane change is possible based on the relative speed with the following vehicle M2 according to the current speed of the host vehicle M (step S26 to step S28).Accordingly, when the preceding vehicle M1, which prohibits the acceleration based on the target speed of the host vehicle M, is located in the adjacent lane L2, it is possible to ensure the safety of the host vehicle M by prohibiting the execution of the lane change accompanied by the acceleration based on the target speed.

[0090] When the following vehicle M2 is located in the adjacent lane L2, which is the lane change target, and the preceding vehicle M1, which prohibits acceleration based on the target speed of the host vehicle M, is located in the adjacent lane L2 while the ACC is being executed, the control device 100 (for example, the lane change determination unit 150) can uniformly determine that the lane change is impossible. In this way, when the preceding vehicle M1, which prohibits acceleration based on the target speed of the host vehicle M, is located in the adjacent lane L2, it is possible to ensure the safety of the host vehicle M by prohibiting the execution of the lane change accompanied by acceleration based on the target speed.

[0091] Even if, while the ACC is being executed, the following vehicle M2 is located on the adjacent lane L2, which is the lane change target, and the preceding vehicle M1, which prohibits acceleration based on the target speed of the host vehicle M, is located on the host lane L1 (step S22: No), the control device 100 (for example, the lane change determination unit 150) determines whether the lane change is possible based on the relative speed to the following vehicle M2 according to the current speed of the host vehicle M (step S26 to step S28).Accordingly, when the preceding vehicle M1, which prohibits the acceleration based on the target speed of the host vehicle M, is located in the host lane L1, it is possible to ensure the safety of the host vehicle M by prohibiting the execution of the lane change accompanied by the acceleration based on the target speed.

[0092] When the following vehicle M2 is located in the adjacent lane L2, which is the lane change target, and the preceding vehicle M1, which prohibits acceleration based on the target speed of the host vehicle M, is located in the host lane L1 while the ACC is being executed, the control device 100 (for example, the lane change determination unit 150) can uniformly determine that the lane change is impossible. In this way, when the preceding vehicle M1, which prohibits acceleration based on the target speed of the host vehicle M, is located in the host lane L1, the safety of the host vehicle M can be ensured by prohibiting the execution of the lane change accompanied by acceleration based on the target speed.

[0093] When the ACC is executed (step S19: Yes), when the current speed of the host vehicle M is lower than the target speed (step S20: Yes), and when the speed difference between the current speed of the host vehicle M and the target speed is equal to or greater than the predetermined threshold (step S21: No), the control device 100 (for example, the lane change determination unit 150) determines whether the lane change is possible based on the relative speed to the following vehicle M2 according to the current speed of the host vehicle M (steps S26 to S28). Accordingly, a lane change in which rapid acceleration might occur can be prevented.That is, in a case where the speed difference between the current speed of the host vehicle M and the target speed is equal to or greater than the threshold, if the lane change is performed along with acceleration based on the target speed, the acceleration during the lane change is excessive, and rapid acceleration may occur during the lane change. If rapid acceleration occurs during the lane change, the driver of the host vehicle M may feel uncomfortable or the noise and vibration (NV) characteristics of the host vehicle M may deteriorate.

[0094] Therefore, as described above, when the speed difference between the current speed of the host vehicle M and the target speed is equal to or greater than the threshold value, the controller 100 determines whether the lane change is possible based on the relative speed with the following vehicle M2 according to the current speed of the host vehicle M, thereby allowing the execution of the lane change only when the lane change is executable without performing the acceleration based on the target speed. Accordingly, it is possible to prevent the execution of the lane change, which might cause rapid acceleration, to avoid the driver feeling uncomfortable or the NV characteristics of the host vehicle M deteriorating, and to improve the marketability of the host vehicle M.

[0095] When ACC is executed when the current speed of the host vehicle M is lower than the target speed and when the speed difference between the current speed of the host vehicle M and the target speed is equal to or greater than the predetermined threshold, the control device 100 (for example, the lane change determination unit 150) can uniformly determine that the lane change is impossible. Also in this way, it is possible to prevent the execution of the lane change that might cause rapid acceleration, to avoid the driver feeling uncomfortable or the NV characteristics of the host vehicle M deteriorating, and to improve the marketability of the host vehicle M.

[0096] If it is determined in the process of step S18 that the following vehicle M2 is not on the adjacent lane L2 which is the lane change destination (step S18: No), as shown in Fig. 11, the controller 100 determines whether the preceding vehicle M1 is located in the adjacent lane L2, which is the lane change destination (step S29).

[0097] If it is determined that the preceding vehicle M1 is not in the adjacent lane L2, which is the lane change target (step S29: No), the controller 100 proceeds to the process of step S33. On the other hand, if it is determined that the preceding vehicle M1 is in the adjacent lane L2, which is the lane change target (step S29: Yes), the controller 100 calculates a relative speed between the host vehicle M and the preceding vehicle M1 (step S30). For calculating the relative speed between the host vehicle M and the preceding vehicle M1, for example, the current speed of the host vehicle M is used. When the ACC is executed, the target speed can be used to calculate the relative speed between the host vehicle M and the preceding vehicle M1.

[0098] Then, the controller 100 calculates an inter-vehicle distance between the host vehicle M and the preceding vehicle M1 (step S31) and determines whether the inter-vehicle distance is equal to or greater than a minimum inter-vehicle distance according to the relative speed calculated in the process of step S30 (step S32).

[0099] If it is determined that the inter-vehicle distance between the host vehicle M and the preceding vehicle M1 is equal to or greater than the minimum inter-vehicle distance (step S32: Yes), the controller 100 determines that the lane change is possible (step S33) and ends the lane change possibility determination process. On the other hand, if it is determined that the inter-vehicle distance between the host vehicle M and the preceding vehicle M1 is less than the minimum inter-vehicle distance (step S32: No), the controller 100 determines that the lane change is impossible (step S34) and ends the lane change possibility determination process.

[0100] After the Fig. 10 and Fig. 11 is executed, the control unit 100 determines whether a determination result of the lane change possibility determination process is that the lane change is possible (step S4), as shown in Fig. 8. When the determination result of the lane change possibility determination process is that the lane change is impossible (step S4: No), the controller 100 ends the current lane change assistance process as it is.

[0101] On the other hand, if the determination result of the lane change possibility determination process is that the lane change is possible (step S4: Yes), the control unit 100 turns on the lane change flag (step S5) and starts turning on the turn signal 83 (step S6).

[0102] Then, the controller 100 determines whether the ACC is currently being executed (step S7). If it is determined that the ACC is not currently being executed (step S7: No), the controller 100 proceeds to the process of step S10, which will be described later. If it is determined that the ACC is currently being executed (step S7: Yes), the controller 100 determines whether the current speed of the host vehicle M is lower than the target speed (step S8).

[0103] If it is determined that the current speed of the host vehicle M is not less than the target speed (step S8: No), the controller 100 proceeds to the process of step S10, which will be described later. If it is determined that the current speed of the host vehicle M is less than the target speed (step S8: Yes), the controller 100 starts acceleration based on the target speed (step S9).

[0104] Then, the controller 100 determines whether there is a traversing start time (step S10). If it is determined that there is no traversing start time (step S10: No), the controller 100 proceeds to the process of step S12 described later as it is. On the other hand, if it is determined that there is a traversing start time (step S10: Yes), the traversing start time is started (step S11) and proceeds to the process of step S12.

[0105] Then determine how in Fig. 9, the control unit 100 determines whether the host vehicle M has not reached the dividing line C of the boundary between the host lane L1 and the adjacent lane L2, which is the lane change target (step S12). If the host vehicle M has reached the dividing line C (step S12: No), the control unit 100 proceeds to the later-described process of step S15 as it is. On the other hand, if the host vehicle M has not yet reached the dividing line C (step S12: Yes), the control unit 100 executes the process shown in Fig. 12, executes the lane change stop determination process (step S13).

[0106] As in Fig. As shown in FIG. 12, in the lane change stop determination process (step S13), the controller 100 first determines whether another vehicle (for example, the following vehicle M2) is located in the adjacent lane L2 that is the lane change target (step S35). If it is determined that the other vehicle is not located in the adjacent lane L2 that is the lane change target (step S35: No), the controller 100 ends the lane change stop determination process as it is.

[0107] On the other hand, if it is determined that the other vehicle is located in the adjacent lane L2, which is the lane change target (step S35: Yes), the controller 100 calculates a relative speed between the host vehicle M and the other vehicle located in the adjacent lane L2 (step S36). For calculating the relative speed between the host vehicle M and the other vehicle, for example, the current speed of the host vehicle M is used.

[0108] Then, the controller 100 calculates an inter-vehicle distance between the host vehicle M and the other vehicle located on the adjacent lane L2 (step S37), and determines whether the inter-vehicle distance is equal to or smaller than a threshold value, which is a lane change stop condition (step S38).

[0109] When it is determined that the inter-vehicle distance between the host vehicle M and the other vehicle located on the adjacent lane L2 is not equal to or smaller than the threshold value which is the lane change stop condition (step S38: No), the controller 100 ends the lane change stop determination process as it is.

[0110] On the other hand, when it is determined that the inter-vehicle distance between the host vehicle M and the other vehicle L2 located on the adjacent lane L2 is equal to or smaller than the threshold value, which is the lane change stop condition (step S38: Yes), the controller 100 stops the lane change and returns the host vehicle M to the center of the host lane L1 (step S39).

[0111] Then, the controller 100 notifies the driver that the lane change has stopped (step S40), turns off the lane change flag (step S41), and ends the lane change stop determination process.

[0112] In this way, the control unit 100 stops the lane change when the inter-vehicle distance between the host vehicle M and the other vehicle traveling in the adjacent lane L2 (for example, the following vehicle M2) becomes short before the host vehicle M reaches the dividing line C, that is, before the host vehicle M deviates from the host lane L1. Accordingly, the safety of the host vehicle M can be ensured.

[0113] After the Fig. 12 is executed, the control unit 100 determines whether the lane change flag is ON (step S14), as shown in Fig. 8. When it is determined that the lane change flag is OFF (step S14: No), the controller 100 ends the current lane change assistance process as it is.

[0114] On the other hand, if it is determined that the lane change flag is ON (step S14: Yes), the controller 100 determines whether the movement to the adjacent lane L2, which is the lane change target, is completed (step S15). If it is determined that the movement to the adjacent lane L2 is completed (step S15: Yes), the controller 100 turns off the turn signal 83 (step S16), turns off the lane change flag (step S17), and ends the current lane change assistance process. On the other hand, if it is determined that the movement to the adjacent lane L2 is not completed (step S15: No), the controller 100 ends the current lane change assistance process as it is.

[0115] As described above, according to the present embodiment, during execution of the vehicle speed control (ie, the ACC), it is possible to determine whether the lane change is possible based on the relative speed to the other vehicle (for example, the following vehicle M2) when the target speed is the vehicle speed of the host vehicle M. Therefore, even if the host vehicle M is traveling at a low speed due to the influence of the preceding vehicle M1 on the host lane L1 or the like, it is possible to appropriately determine whether the lane change is possible by taking into account the acceleration based on the target speed that is possible due to the lane change, and it is possible to increase the opportunity to execute the lane change while ensuring the safety of the host vehicle M.

[0116] Although an embodiment of the present invention has been described above with reference to the drawings, it goes without saying that the present invention is not limited to the above-described embodiment. It is understood that those skilled in the art can devise various modifications and changes within the scope described in the claims, and it is understood that such modifications and changes naturally fall within the technical scope of the present invention. Furthermore, the constituent elements in the above-described embodiment can be freely combined within a scope that does not deviate from the spirit of the invention.

[0117] For example, in the above-described embodiment, the example in which the predetermined operation as the lane change request is the semi-lock operation of the turn signal lever 81 was described, but the present invention is not limited to this. The predetermined operation as the lane change request is not limited to the semi-lock operation of the turn signal lever 81 and may be any operation using various operating elements. For example, an automatic lane change button may be provided on the steering wheel 82, and the predetermined operation as the lane change request may be performed by pressing this button.

[0118] The controller 100 may suggest the execution of the lane change to the driver based on the speed difference between the current speed of the host vehicle M and the target speed during the execution of the ACC. For example, if the current speed of the host vehicle M is less than the target speed during the execution of the ACC and the speed difference between the current speed of the host vehicle M and the target speed is equal to or greater than the predetermined threshold, it is assumed that the host vehicle M is traveling at a low speed due to the influence of the preceding vehicle M1 or the like.Therefore, during the execution of the ACC, if the current speed of the host vehicle M is lower than the target speed and the speed difference between the current speed of the host vehicle M and the target speed is equal to or greater than the threshold, the controller 100 can suggest the driver to execute the lane change to enable driving at the target speed. In this way, it becomes possible to prompt the driver to perform the lane change appropriately, improve driver comfort, and enhance the marketability of the host vehicle M.

[0119] In the above-described embodiment, the control unit 100 executes the lane change when there is a lane change request from the driver, but the present invention is not limited to this. For example, regardless of the presence or absence of a lane change request from the driver, the control unit 100 may appropriately determine the necessity of the lane change based on the driving conditions of other vehicles, a route to a destination, or the like, and may automatically execute the lane change when it determines that the lane change is necessary.

[0120] Specifically, for example, when the ACC is currently being executed and the preceding vehicle M1, traveling at a lower speed than the target speed of the host vehicle M, is located in the host lane L1, the controller 100 may automatically execute the lane change. As a specific example, when the current speed of the host vehicle M is lower than the target speed during the execution of the ACC, and the speed difference between the current speed of the host vehicle M and the target speed is equal to or greater than the threshold, the controller 100 may automatically execute the lane change to enable traveling at the target speed.Even if the lane change is configured to be automatically executed during the execution of the ACC, when the following vehicle M2 is located in the adjacent lane L2, the control unit 100 can determine whether the lane change is possible based on the relative speed to the following vehicle M2 when the target speed is the traveling speed of the host vehicle M. Since the control unit 100 is configured to be able to automatically execute the lane change in this way, it is possible to automatically execute an appropriate lane change, improve the driver's comfort, and improve the marketability of the host vehicle M.

[0121] When the lane change is performed automatically, the control unit 100 can notify the driver that the lane change is about to be performed. This avoids the driver feeling uncomfortable or uneasy because the lane change is performed without prior notice.

[0122] In the present specification and the like, at least the following items are described. Although the corresponding components and the like are shown in parentheses in the above-described embodiment, the present invention is not limited thereto. (1) A lane change assist device (control unit 100) capable of performing a lane change of a host vehicle (host vehicle M) from a host lane (host lane L1) on which the host vehicle is traveling to a lane adjacent to the host lane (adjacent lane L2), the lane change assist device including: a detection unit (detection unit 130) configured to detect an environmental situation of the host vehicle; a lane change determination unit (lane change determination unit 150) configured to determine, when another vehicle traveling in the adjacent lane is detected by the detection unit, whether the lane change is possible based on a relative speed between the host vehicle and the other vehicle and an inter-vehicle distance between the host vehicle and the other vehicle; and a driving control unit (driving control unit 170) configured to execute the lane change based on a determination result of the lane change determination unit, wherein the driving control unit is configured to further execute a driving speed control (ACC) for controlling a driving speed of the host vehicle based on a preset target speed, and the lane change determination unit is configured to determine, while the vehicle speed control is being executed, when the target speed is the vehicle speed of the host vehicle, whether the lane change is possible based on the relative speed.

[0123] According to (1), when the host vehicle is traveling at a low speed due to the influence of a preceding vehicle on the host lane or the like, it is possible to appropriately determine whether the lane change is possible by taking into account the acceleration based on the target speed that is possible due to the lane change, and it is possible to improve an opportunity to perform the lane change while ensuring the safety of the host vehicle. (2) The lane change assist device according to (1), wherein the other vehicle is a following vehicle following the host vehicle.

[0124] According to (2), it can be appropriately determined whether the lane change is also possible if the following vehicle is driving in the adjacent lane.

[0125] (3) The lane change assist device according to (2), wherein the traveling speed control is a control for setting the traveling speed of the host vehicle to the target speed when there is no preceding vehicle in front of the host vehicle on the host lane, and for adjusting the traveling speed of the host vehicle according to the traveling speed of the preceding vehicle when the preceding vehicle is on the host lane.

[0126] According to (3), by the traveling speed control, the traveling speed of the host vehicle can be appropriately controlled taking into account the presence or absence of the preceding vehicle on the host lane and its traveling speed, and therefore, it is possible to reduce fatigue of a driver of the host vehicle or the like while ensuring the safety of the host vehicle.

[0127] (4) The lane change assist device according to (3), wherein the traveling control unit is configured to, when the lane change is executed during the execution of the traveling speed control, accelerate the host vehicle based on the target speed before completing the movement to the adjacent lane by the lane change.

[0128] According to (4), since the host vehicle is accelerated based on the target speed before completing the movement to the adjacent lane by the lane change, an inter-vehicle distance between the host vehicle and the following vehicle traveling in the adjacent lane is prevented from being shortened, and the lane change can be performed while ensuring the safety of the host vehicle.

[0129] (5) The lane change assist device according to (4), wherein the travel control unit is configured to, when the lane change is executed during the execution of the travel speed control, accelerate the host vehicle to the target speed before completing the movement to the adjacent lane by the lane change.

[0130] According to (5), since the host vehicle is accelerated to the target speed before completing the movement to the adjacent lane by the lane change, the inter-vehicle distance between the host vehicle and the following vehicle traveling in the adjacent lane is prevented from being shortened, and the lane change can be performed while ensuring the safety of the host vehicle.

[0131] (6) The lane change assist device according to any one of (3) to (5), wherein in a case where the vehicle speed control is being executed and further there is a preceding vehicle in the adjacent lane that prohibits acceleration based on the target speed of the host vehicle, the lane change determining unit determines not to execute the lane change.

[0132] According to (6), when the preceding vehicle is located in the adjacent lane, which prevents the acceleration of the host vehicle, it is possible to ensure the safety of the host vehicle by preventing the execution of the lane change accompanied by the acceleration based on the target speed.

[0133] (7) The lane change assist device according to any one of (3) to (6), wherein in a case where the vehicle speed control is being executed and further there is a preceding vehicle in the host lane that prohibits acceleration based on the target speed of the host vehicle, the lane change determining unit determines not to execute the lane change.

[0134] According to (7), when the preceding vehicle is located in the host lane, which prevents the acceleration of the host vehicle, it is possible to ensure the safety of the host vehicle by preventing the execution of the lane change accompanied by the acceleration based on the target speed.

[0135] (8) The lane change assist device according to any one of (3) to (7), wherein, when the vehicle speed control is being executed and a speed difference between a current vehicle speed of the host vehicle and the target vehicle speed is equal to or greater than a threshold value, the lane change determining unit determines not to execute the lane change.

[0136] If rapid acceleration occurs during lane change, the host vehicle driver may feel uncomfortable or the host vehicle's noise and vibration (NV) characteristics may deteriorate. According to (8), it is possible to prevent the execution of lane change during which rapid acceleration may occur, thus preventing the host vehicle driver from feeling uncomfortable or the host vehicle's NV characteristics from deteriorating, and improving the marketability of the host vehicle.

[0137] (9) The lane change assist device according to any one of (3) to (8), further comprising: a notification control unit (notification control unit 167) configured to, when the vehicle speed control is being executed and the preceding vehicle is in the host lane, suggest the lane change to a driver of the host vehicle based on a speed difference between a current vehicle speed of the host vehicle and the target speed.

[0138] According to (9), it is possible to prompt the driver to perform lane changing appropriately, improve the driver's comfort, and improve the marketability of the host vehicle.

[0139] (10) The lane change assist device according to any one of (1) to (9), wherein when there is a lane change request from the driver of the host vehicle, the lane change determining unit determines whether the lane change is possible.

[0140] According to (10) it is possible to avoid executing a lane change against the driver's will.

[0141] (11) The lane change assist device according to (10), wherein the lane change request is a predetermined operation of a turn signal lever (turn signal lever 81) of the host vehicle, a position to which the turn signal lever is movable, includes: a neutral position, a first position arranged in each of two directions different from the neutral position and returning to the neutral position when the driver does not apply any operating force to the turn signal lever, and a second position located in each of two directions relative to the neutral position, having an amount of movement from the neutral position greater than that of the first position, and capable of being maintained when the driver does not apply any operating force to the turn signal lever, and the predetermined operation is an operation to hold the turn signal lever in the first position.

[0142] According to (11), it is possible to receive the lane change request without providing an operation button or the like separate from the turn signal lever for receiving the lane change request.

[0143] (12) The lane change assist device according to any one of (1) to (11), wherein in a case where the lane change is being performed and the inter-vehicle distance is equal to or smaller than a threshold before the host vehicle reaches a dividing line configured to separate the host lane from the adjacent lane, the travel control unit stops the lane change.

[0144] According to (12), when the inter-vehicle distance between the host vehicle and the vehicle following in the adjacent lane becomes short before the host vehicle reaches the dividing line (ie, before the host vehicle deviates from the host lane), the lane change is stopped, and thus the safety of the host vehicle can be ensured. LIST OF REFERENCE SYMBOLS 81 Turn signal lever 100 Control unit (lane change assistance device) 130 detection unit 150 Lane change determination unit 170 drive control unit 167 Reporting control unit L1 host lane L2 adjacent lane M Host vehicle M1 vehicle ahead (other vehicle) M2 following vehicle (other vehicle) QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2017-074 823 A

[0003]

Claims

[1] A lane change assistance device capable of performing a lane change of a host vehicle from a host lane in which the host vehicle is traveling to a lane adjacent to the host lane, the lane change assistance device comprising: a detection unit configured to detect an environmental situation of the host vehicle; a lane change determination unit configured to, when another vehicle traveling in the adjacent lane is detected by the detection unit, determine whether the lane change is possible based on a relative speed between the host vehicle and the other vehicle and an inter-vehicle distance between the host vehicle and the other vehicle; and a driving control unit configured to execute the lane change based on a determination result of the lane change determination unit, wherein the travel control unit is configured to further perform a travel speed control for controlling a travel speed of the host vehicle based on a preset target speed, and the lane change determination unit is configured to, when the target speed is the traveling speed of the host vehicle while the traveling speed control is being executed, determine whether the lane change is possible based on the relative speed. [2] The lane change assist device according to claim 1, wherein the other vehicle is a following vehicle following the host vehicle. [3] The lane change assist device according to claim 2, wherein the traveling speed control is a control for setting the traveling speed of the host vehicle to the target speed when there is no preceding vehicle in front of the host vehicle on the host lane, and for adjusting the traveling speed of the host vehicle according to the traveling speed of the preceding vehicle when the preceding vehicle is on the host lane. [4] The lane change assist device according to claim 3, wherein the traveling control unit is configured to, when the lane change is executed during the execution of the traveling speed control, accelerate the host vehicle based on the target speed before completing the movement to the adjacent lane by the lane change. [5] The lane change assist device according to claim 4, wherein the traveling control unit is configured to, when the lane change is executed during the execution of the traveling speed control, accelerate the host vehicle to the target speed before completing the movement to the adjacent lane by the lane change. [6] The lane change assist device according to any one of claims 3 to 5, wherein in a case where the vehicle speed control is being executed and further there is a preceding vehicle in the adjacent lane that prohibits acceleration based on the target speed of the host vehicle, the lane change determining unit determines not to execute the lane change. [7] The lane change assist device according to any one of claims 3 to 6, wherein in a case where the vehicle speed control is being executed and further there is a preceding vehicle in the host lane that prohibits acceleration based on the target speed of the host vehicle, the lane change determining unit determines not to execute the lane change. [8] The lane change assist device according to any one of claims 3 to 7, wherein in a case where the vehicle speed control is being executed and a speed difference between a current vehicle speed of the host vehicle and the target speed is equal to or greater than a threshold value, the lane change determining unit determines not to execute the lane change. [9] The lane change assist device according to any one of claims 3 to 8, further comprising: a notification control unit configured to, when the vehicle speed control is being executed and the preceding vehicle is in the host lane, suggest the lane change to a driver of the host vehicle based on a speed difference between a current vehicle speed of the host vehicle and the target speed. [10] The lane change assist device according to any one of claims 1 to 9, wherein, when there is a lane change request from the driver of the host vehicle, the lane change determining unit determines whether the lane change is possible. [11] The lane change assist device according to claim 10, wherein the lane change request is a predetermined operation of a turn signal lever of the host vehicle, a position to which the turn signal lever can be moved includes a neutral position, a first position arranged in each of two directions different from the neutral position and returning to the neutral position when the driver does not apply any operating force to the turn signal lever, and a second position located in each of two directions relative to the neutral position, having an amount of movement from the neutral position greater than that of the first position, and capable of being maintained when the driver does not apply any operating force to the turn signal lever, and the predetermined operation is an operation to hold the turn signal lever in the first position. [12] The lane change assist device according to any one of claims 1 to 11, wherein when the lane change is being performed and the inter-vehicle distance is equal to or less than a threshold before the host vehicle reaches a dividing line configured to separate the host lane from the adjacent lane, the driving control unit stops the lane change.

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