JP2022110603A - Vehicle travel control method and travel control device - Google Patents

Abstract

To provide a vehicle travel control method and a travel control device capable of recognizing a lane marker after changing lanes when changing lanes through autonomous travel control.SOLUTION: A vehicle travel control method which executes autonomous lane change control from a lane L1 on which a vehicle is currently traveling to a target lane L2: detects a travel state of an own vehicle V1; estimates a shape of a road on which the own vehicle is currently traveling on the basis of lateral lane marker information to be detected at a side of the own vehicle; generates a target trajectory when executing the autonomous lane change control on the basis of a start instruction through the autonomous lane change control; and generates a control command value for the autonomous lane change control on the basis of the detected travel state of the own vehicle, the estimated shape of the road and the generated target trajectory.SELECTED DRAWING: Figure 6

Description

The present invention relates to a vehicle cruise control method and a vehicle cruise control device.

As a conventional road information recognition method, the lane marker of the lane in which the vehicle is traveling is detected, the lane marker and lane width of the lane adjacent to this lane are detected, and the lane before and after the lane change is detected. There is known a method of estimating a lane marker paired with a nearby lane marker of a lane after a lane change, using a lane marker common to both lanes and a lane width of the lane after the lane change (see Patent Document 1).

JP 2017-134664 A

However, with the above-described conventional road information recognition method, when estimating a lane marker for a lane after a lane change, there is a problem that if a nearby lane marker cannot be detected, a paired distant lane marker cannot be estimated.

The problem to be solved by the present invention is to provide a vehicle cruise control method and a cruise control device that can recognize a lane marker after a lane change when changing lanes by autonomous cruise control.

The present invention estimates the shape of the road on which the vehicle is currently traveling based on the side lane marker information detected on the side of the own vehicle, and generates the estimated road shape and the detected running state of the own vehicle. The above problem is solved by generating a control command value for autonomous lane change control based on the calculated target trajectory.

ADVANTAGE OF THE INVENTION According to this invention, the lane marker after lane change is recognizable at the time of the lane change by autonomous driving control.

1 is a block diagram showing an embodiment of a vehicle running control device according to the present invention; FIG. 2 is a front view showing part of the input device of FIG. 1; FIG. FIG. 2 is a plan view showing an example of lane change control of the cruise control device of FIG. 1; FIG. 2 is a plan view showing an example of mounting a front camera, a side camera, and a rear camera included in the sensor of FIG. 1; Each of (A) and (B) is a plan view showing an example of lane change control using a front camera. 2 is a block diagram showing an example of a lane change control unit included in the control device of FIG. 1; FIG. FIG. 7 is a diagram showing an example of processing executed by the lane change target trajectory generation unit of FIG. 6; (A) and (B) are plan views showing an example of lane change control using a front camera and a side camera. It is a figure which shows the example of a process performed by the road curvature estimation part of FIG. 7 is a diagram showing an example of processing executed by a first follow-up command value generator and a second follow-up command value generator of FIG. 6; FIG. FIG. 7 is a flow chart showing an example of control processing executed by the lane change control unit of FIG. 6; FIG.

<<Configuration of Travel Control Device>>
BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a vehicle running control device 1 according to this embodiment. The cruise control device 1 of the present embodiment is also an embodiment for carrying out the vehicle cruise control method according to the present invention.

As shown in FIG. 1, the cruise control device 1 of this embodiment includes a sensor 11, a vehicle position detection device 12, a map database 13, an in-vehicle device 14, a navigation device 15, a presentation device 16, an input device 17, and a drive control device. 18 and a controller 19 . These devices are connected, for example, by a CAN (Controller Area Network) or other in-vehicle LAN, and can mutually transmit and receive information.

A sensor 11 detects the running state of the host vehicle. For example, the sensors 11 may include a front camera that captures the front of the vehicle, side cameras that capture the left and right sides of the vehicle, rear cameras that capture the rear of the vehicle, and obstacles in front of the vehicle. forward radar that detects obstacles behind the vehicle, side radar that detects obstacles on the left and right sides of the vehicle, vehicle speed sensor that detects the vehicle speed, and the driver turning the steering wheel Examples include a touch sensor (capacitance sensor) that detects whether or not the device is held, and an in-vehicle camera that captures an image of the driver. As the sensor 11, one of the plurality of sensors described above may be used, or two or more types of sensors may be used in combination. The detection result of the sensor 11 is output to the control device 19 at predetermined time intervals.

The own vehicle position detection device 12 includes a GPS unit, a gyro sensor, a vehicle speed sensor, and the like. The own vehicle position detection device 12 detects radio waves transmitted from a plurality of satellite communications by the GPS unit, and periodically acquires the position information of the target vehicle (own vehicle). Also, the vehicle position detection device 12 detects the current position of the target vehicle based on the acquired position information of the target vehicle, the angle change information acquired from the gyro sensor, and the vehicle speed acquired from the vehicle speed sensor. The position information of the target vehicle detected by the own vehicle position detection device 12 is output to the control device 19 at predetermined time intervals.

The map database 13 is a memory that stores three-dimensional high-precision map information including position information of various facilities and specific points, and is accessible from the control device 19 . The three-dimensional high-precision map information is three-dimensional map information based on road shapes detected when a data acquisition vehicle is used to travel on actual roads. The three-dimensional high-precision map information, together with the map information, includes detailed and high-precision information such as curved roads and their curve sizes (e.g., curvature or radius of curvature), road junctions, junctions, toll booths, and locations where the number of lanes decreases. is map information associated as three-dimensional information. However, the map information stored in the map database of the present invention is not limited to 3D high-precision map information, and may be other map information.

The in-vehicle device 14 is various devices mounted in the vehicle, and is operated by the driver's operation. Such in-vehicle devices include steering wheels, accelerator pedals, brake pedals, direction indicators, wipers, lights, horns, and other specific switches. The in-vehicle device 14 outputs the operation information to the control device 19 when operated by the driver.

The navigation device 15 acquires the current position information of the own vehicle from the own vehicle position detection device 12, and superimposes the position of the own vehicle on the map information for guidance and displays it on a display or the like. The navigation device 15 also has a navigation function of calculating a route to the destination when the driver inputs the destination and guiding the driver along the set route. With this navigation function, the navigation device 15 displays the route to the destination on the map on the display, and notifies the driver of the recommended driving behavior on the route by voice or the like.

The presentation device 16 includes various displays such as a display included in the navigation device 15, a display incorporated in the rearview mirror, a display incorporated in the meter section, and a head-up display projected onto the windshield. Also, the presentation device 16 includes devices other than the display, such as a speaker of an audio device, a seat device in which a vibrating body is embedded, and the like. The presentation device 16 informs the driver of various presentation information under the control of the control device 19 .

The input device 17 is, for example, a device such as a button switch that allows manual input by the driver, a touch panel that is arranged on a display screen, or a microphone that allows driver's voice input. In this embodiment, the driver can input setting information for the presentation information presented by the presentation device 16 by operating the input device 17 . FIG. 2 is a front view showing part of the input device 17 of the present embodiment, and shows an example of button switches arranged on the spokes of a steering wheel or the like.

The illustrated input device 17 is a button switch used when setting ON/OFF of the autonomous travel control function (autonomous speed control function and autonomous steering control function) provided in the control device 19 . Details of the autonomous cruise control function including the autonomous speed control function and the autonomous steering control function will be described later. The input device 17 of this embodiment includes a main switch 171 , a resume/accelerate switch 172 , a set/coast switch 173 , a cancel switch 174 , a distance control switch 175 , and a lane change support switch 176 .

The main switch 171 is a switch for turning ON/OFF the power of the system that realizes the autonomous speed control function and the autonomous steering control function of the control device 19 . The resume/accelerate switch 172 turns off the autonomous speed control function once, and then resumes the autonomous speed control function at the set speed before turning it off, or the preceding vehicle (another vehicle traveling in the same lane as the host vehicle. The same applies in this specification), and then the vehicle is stopped and then restarted by the control device 19, or for an acceleration operation to increase the set speed. The set/coast switch 173 is a switch for performing a set operation to start the autonomous speed control function at the running speed and a coast operation to lower the set speed. The cancel switch 174 is a switch for turning off the autonomous speed control function. The inter-vehicle distance adjustment switch 175 is a switch for setting the inter-vehicle distance to the preceding vehicle, and is a switch for selecting one from a plurality of settings such as short distance, medium distance, and long distance. The lane change support switch 176 is a switch for accepting the start of lane change when the controller 19 confirms the start of the lane change with the driver. By pressing the lane change support switch 176 longer than a predetermined time after approving the start of lane change, the approval of the lane change proposal by the control device 19 can be cancelled.

In addition to the button switch group shown in FIG. 2 , a direction indicator lever of a direction indicator or other switches of the vehicle-mounted device 14 can be used as the input device 17 . For example, when the control device 19 proposes whether or not to change lanes by autonomous control, the driver turns on the switch of the direction indicator to input approval or permission of the lane change. can also Further, when the control device 19 suggests whether or not to change lanes by autonomous control, when the driver operates the direction indicator lever, the direction indicator lever is operated instead of the proposed lane change. It is also possible to adopt a configuration in which a lane change is performed by The setting information input by the input device 17 is output to the control device 19 .

The drive control device 18 controls running of the host vehicle in various ways. For example, when the self-vehicle runs at a set speed by the autonomous speed control function, the drive control device 18 accelerates, decelerates, and maintains the running speed so that the self-vehicle reaches the set speed. Operation of the drive mechanism (in the case of a gasoline engine vehicle, the operation of the internal combustion engine; in the case of an electric vehicle, the operation of the drive motor; in the case of a hybrid vehicle, the torque distribution between the internal combustion engine and the drive motor). and control the braking action. In addition, the drive control device 18 realizes acceleration/deceleration and running speed so that the distance between the vehicle and the preceding vehicle is constant when the vehicle follows the preceding vehicle by the autonomous speed control function. control the operation of the drive mechanism and brake operation for

Further, the drive control device 18 performs steering control of the own vehicle by controlling the operation of the steering actuator in addition to the above-described operation control of the drive mechanism and the brake by the autonomous steering control function. For example, when the drive control device 18 executes lane keeping control by the autonomous steering control function, the drive control device 18 detects the lane marker of the own lane (the lane in which the own vehicle travels; hereinafter the same applies in this specification), and the own vehicle The traveling position of the own vehicle in the width direction is controlled so that the own vehicle travels at a predetermined position within the own lane. Further, the drive control device 18 controls the traveling position of the own vehicle in the width direction so that the own vehicle changes lanes when lane change support is executed by a lane change support function, which will be described later. Furthermore, the drive control device 18 performs running control to turn right or left at an intersection or the like when executing right/left turn support by the autonomous steering control function. The drive control device 18 controls the running of the own vehicle according to instructions from the control device 19, which will be described later. Other known methods can also be used as the travel control method by the drive control device 18 .

The control device 19 includes a ROM (Read Only Memory) that stores a program for controlling the running of the vehicle, a CPU (Central Processing Unit) that executes the program stored in the ROM, and an accessible storage device. Equipped with functioning RAM (Random Access Memory). In addition, as the operation circuit, instead of or together with the CPU (Central Processing Unit), MPU (Micro Processing Unit), DSP (Digital Signal Processor), ASIC (Application Specific Integrated Circuit), FPGA (Field Programmable Gate Array), etc. can be used.

<<Function realized by the control device 19>>
The control device 19 has a running information acquisition function for acquiring information about the running state of the own vehicle, a running scene determination function for determining the running scene of the own vehicle, and a running scene determining function for determining the running scene of the own vehicle. and an autonomous cruise control function that autonomously controls the running speed and/or steering of the vehicle. Each function of the control device 19 will be described below.

The travel information acquisition function of the control device 19 is a function for the control device 19 to acquire travel information regarding the travel state of the own vehicle. For example, the control device 19 acquires image information of the exterior of the vehicle captured by the front camera, rear camera, and side camera of the sensor 11 as travel information. In addition, the control device 19 acquires detection results from the front radar, the rear radar, and the side radar as travel information. Furthermore, the control device 19 also receives vehicle speed information of the own vehicle detected by the vehicle speed sensor of the sensor 11, attitude angle and yaw rate of the own vehicle detected by the gyro sensor, and image information of the driver's face captured by the in-vehicle camera. Acquired as driving information.

Further, the control device 19 acquires current position information of the vehicle from the vehicle position detection device 12 as travel information. Further, the control device 19 acquires the set destination and the route to the destination from the navigation device 15 as travel information. Further, the control device 19 acquires location information such as curved roads and their curve sizes (e.g., curvature or radius of curvature), junctions, junctions, toll gates, and locations where the number of lanes decreases from the map database 13 as travel information. do. In addition, the control device 19 acquires operation information of the in-vehicle device 14 by the driver from the in-vehicle device 14 as driving information. The above is the travel information acquisition function realized by the control device 19 .

The driving scene determination function of the control device 19 refers to a table stored in the ROM of the control device 19 to determine the driving scene in which the host vehicle is running. A table stored in the ROM of the control device 19 stores, for example, driving scenes suitable for changing lanes and overtaking and determination conditions for each driving scene. The control device 19 refers to the table stored in the ROM and determines whether or not the driving scene of the own vehicle is suitable for, for example, changing lanes or overtaking.

For example, the judgment conditions for the "catch-up scene" include "preceding vehicle exists in front", "preceding vehicle speed < own vehicle's set speed", "predetermined time to reach the preceding vehicle", and Suppose that four conditions are set, that is, "the lane change direction is not a lane change prohibition condition." In this case, the control device 19, for example, the detection result by the front camera and the front radar included in the sensor 11, the vehicle speed detected by the vehicle speed sensor, the position information of the vehicle by the vehicle position detection device 12, and the like. Based on this, it is determined whether or not the host vehicle satisfies the above conditions. When the above conditions are satisfied, the control device 19 determines that the subject vehicle is in a "catch-up scene with the preceding vehicle". The driving scene determination function realized by the control device 19 has been described above.

The autonomous driving control function of the control device 19 is a function for the control device 19 to autonomously control the driving of the own vehicle without depending on the driver's operation. The autonomous travel control function of the control device 19 includes an autonomous speed control function that autonomously controls the travel speed of the vehicle, and an autonomous steering control function that autonomously controls the steering of the vehicle. It should be noted that autonomous control without relying on the operation of the driver also includes performing some operations by the driver. Also, the autonomous speed control function and the autonomous steering control function may be functions independent of each other or may be functions related to each other. The autonomous speed control function and the autonomous steering control function of this embodiment will be described below.

When a vehicle ahead is detected, the autonomous speed control function sets the vehicle speed set by the driver as the upper limit and controls the distance between the vehicles according to the vehicle speed while following the vehicle ahead. If the vehicle is not detected, it will run at a constant speed set by the driver. The former is also called inter-vehicle control, and the latter is called constant speed control. The autonomous speed control function detects the speed limit of the road on which the vehicle is traveling from the road signs by the sensor 11, or acquires the speed limit from map information in the map database 13, and automatically adjusts the speed limit to the set vehicle speed. may include the ability to

To activate the autonomous speed control function, the driver first operates the resume/accelerate switch 172 or the set/coast switch 173 of the input device 17 shown in FIG. 2 to input a desired running speed. For example, if the set coast switch 173 is pressed while the vehicle is traveling at 70 km/h, the current traveling speed is set as is. The set speed can be increased by pressing the switch 172 multiple times. The "+" mark attached to the resume/accelerate switch 172 indicates that it is a switch for increasing the set value. Conversely, if the speed desired by the driver is 60 km/h, the set coast switch 173 should be pressed a plurality of times to lower the set speed. The "-" mark attached to the set/coast switch 173 indicates that it is a switch that decreases the set value. Further, the driver's desired inter-vehicle distance can be selected by operating the inter-vehicle distance adjustment switch 175 of the input device 17 shown in FIG.

Constant-speed control, in which the vehicle travels at a constant speed set by the driver, is executed when the forward radar of the sensor 11 or the like detects that there is no preceding vehicle ahead of the own lane. In constant speed control, the drive control device 18 controls the operation of drive mechanisms such as the engine and brakes while feeding back vehicle speed data from a vehicle speed sensor so as to maintain a set running speed.

The inter-vehicle distance control, in which the vehicle follows the preceding vehicle while performing the inter-vehicle distance control, is executed when the forward radar of the sensor 11 or the like detects that there is a preceding vehicle ahead of the own lane. In the inter-vehicle distance control, the driving mechanism such as the engine and the brakes is operated by the drive control device 18 while feeding back the inter-vehicle distance data detected by the front radar so as to maintain the set inter-vehicle distance with the set running speed as the upper limit. controls the behavior of Note that when the preceding vehicle stops while traveling under inter-vehicle distance control, the host vehicle also stops following the preceding vehicle. Further, when the preceding vehicle starts moving within, for example, 30 seconds after the own vehicle stops, the own vehicle also starts and starts the follow-up running by the vehicle-to-vehicle distance control again. If the own vehicle has been stopped for more than 30 seconds, it will not automatically start even if the preceding vehicle starts moving. , the follow-up running is started again by the vehicle-to-vehicle distance control.

On the other hand, the autonomous steering control function is a function for executing steering control of the own vehicle by controlling the operation of the steering actuator. The autonomous steering control function of the present embodiment includes (1) a lane keeping function (lane width direction maintaining function) that controls the steering so that the driver runs in the center of the lane, for example, and assists the driver in operating the steering wheel; ) When the driver operates the turn signal lever, the steering is controlled, and the lane change assist function assists the steering operation required to change lanes. (4) If the driver has set a destination in the navigation device, etc., the vehicle will run according to the route. When the vehicle arrives at the lane change point required to change lanes, a display is displayed to confirm the driver's intention to change lanes. . When the autonomous steering control is executed, the autonomous speed control is also executed at the same time, but the speed control may be executed by the driver's accelerator/brake operation.

Here, the lane change support function among the autonomous steering control functions will be described. In addition to lane change assistance, autonomous speed control is also executed at the same time. FIG. 3 is a plan view showing an example of lane change control (lane change support function) executed by the control device 19 of the present embodiment. As shown in FIG. 3, when the driver operates the turn signal lever of the vehicle V1, the control device 19 turns on the direction indicator, and when a preset lane change start condition is satisfied, the lane change operation LCP (Lane Change Process) is satisfied. refers to a series of processing for autonomous lane change.) is started. The control device 19 determines whether or not a lane change start condition is satisfied based on various types of travel information acquired by the sensor 11 . Conditions for starting a lane change are not particularly limited, but (1) the vehicle is in lane keep mode, (2) the driver is holding the steering wheel, and (3) the vehicle is traveling at a speed of 60 km/h or more. , (4) there is a lane in the lane change direction, (5) there is a lane changeable space in the destination lane, (6) the lane marker type is lane changeable, (7) the road For example, all the conditions (1) to (8) are satisfied, such as the radius of curvature being 250 m or more, and (8) the driver operating the direction indicator lever within 1 second. When the control device 19 determines that the lane change start condition is satisfied by the lane change support function without an instruction from the driver, the control device 19 notifies the driver through the presentation device 16, thereby proposing a lane change to the driver. You may

When the lane change start condition is satisfied, the control device 19 starts the lane change operation LCP. As shown in FIG. 3, the lane change operation LCP of the present embodiment includes lateral movement of the vehicle V1 toward the adjacent lane L2 within the vehicle lane L1, and crossing of the lane marker from the vehicle V1 from the vehicle lane L1. Lane Change Manipulation (LCM) for moving to the adjacent lane L2. While the lane change operation LCP is being performed, the control device 19 presents information indicating that the lane is being changed by autonomous control to the driver via the presentation device 16 to urge the driver to pay attention to the surroundings. When the lane change maneuver LCM is completed, the control device 19 turns off the direction indicator and starts executing the lane keeping function in the adjacent lane L2. Note that the lane change operation LCP refers to the period from turning on the direction indicator by operating the turn signal lever to turning off the turn signal, and the lane change operation LCM is performed when the own vehicle V1 starts stepping on the boundary line between the own lane L1 and the adjacent lane L2. It refers to the period from the start to the end of the step.

Now, when executing a lane change using the lane change support function of the autonomous steering control function, after the control device 19 recognizes the position of the own lane, the position of the adjacent lane to which the lane is to be changed, and the curvature of the road, , it is necessary to confirm whether or not there is a space for the own vehicle in this adjacent lane. In this case, if 3D high-precision map information is stored in the map database 13, positional information of own lane and adjacent lanes and road curvature information are included, but 3D high-precision map information is not included. For roads without such sensors, it is necessary to image the actual road using the front camera, side camera, and rear camera of the sensor 11, and to recognize the positions of the own lane and adjacent lanes and the curvature of the road.

FIG. 4 is a plan view showing a mounting example of the front camera 111, the side camera 112, and the rear camera 113 included in the sensor 11 of FIG. In the mounting example shown in the figure, the front camera 111 is provided in the center of the front grille or front bumper of the vehicle V, and images the front scanning area FA of the vehicle V. As shown in FIG. The side cameras 112 are provided in the door mirrors of the vehicle V and capture images of the left and right side scanning areas SA of the vehicle V, respectively. The rear camera 113 is provided in the center of the trunk lid, the back door, or the rear bumper, and images the rear scanning area BA of the vehicle V. As shown in FIG. Although not particularly limited, the forward scanning area FA imaged by the front camera 111, the forward scanning area SA imaged by the side camera 112, and the backward scanning area BA imaged by the rearward camera 113 are fan-shaped with a radius of about 10 m. It is

FIG. 5 shows an example of autonomous lane change control using the front camera 111, the side camera 112, and the rear camera 113 mounted in this manner. FIG. 5A is a plan view showing a scene in which the host vehicle V1 changes lanes to the adjacent lane L2 and overtakes or overtakes the preceding vehicle V2 while the host vehicle V1 and the preceding vehicle V2 are traveling in the own lane L1. . In this case, the positions of the lane markers LM1 and LM2 of the own lane L1 and the positions of the lane markers LM2 and LM3 of the adjacent lane L2 to which the lane is to be changed can be detected by the forward camera 111 even if the attitude (yaw angle) of the own vehicle V1 changes due to the lane change. , the control device 19 can recognize the position of the own lane L1 and the position of the adjacent lane L2 to which the lane is to be changed. In addition, after recognizing the position of the own lane L1 and the position of the adjacent lane L2, the forward camera 111 can also confirm whether or not there is a space for the own vehicle V1 in the adjacent lane L2.

On the other hand, as shown in FIG. 5B, when the attitude (yaw angle) of the own vehicle V1 increases due to the lane change, the positions of the lane markers LM1 and LM2 of the own lane L1 and the lane marker LM2 of the adjacent lane L2 of the lane change destination are changed. , LM3 are no longer included in the forward scanning area FA by the front camera 111, the control device 19 cannot recognize the position of the own lane L1 and the position of the adjacent lane L2 to which the lane is to be changed. Therefore, the autonomous lane change control is interrupted or stopped, and the driver has to shift to manual operation. Such a situation often occurs when the inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 is short.

Therefore, in the vehicle running control device 1 according to the present embodiment, the forward scanning area FA by the front camera 111 does not include the lane markers LM1 and LM2 of the own lane L1 and the lane markers LM2 and LM3 of the adjacent lane L2 to which the lane is to be changed. When the autonomous lane change control cannot be continued, the side camera 112 is used to recognize the lane markers LM1 and LM2 of the own lane L1 and the lane markers LM2 and LM3 of the adjacent lane L2 to be changed. An embodiment of lane change control using the front camera 111 and the side camera 112 will be described below. FIG. 6 is a block diagram showing an example of a lane change control unit 190 included in the control device 19, and FIGS. It is a top view which shows an example.

As shown in FIG. 6, the lane change control unit 190 of the present embodiment includes a lane change target trajectory generator 191, a forward lane marker estimator 192, a first follow command value generator 193, and a road curvature estimator 194. , a second follow command value generation unit 195 and a command value switching unit 196, which are equipped with a front camera 111 as a front lane marker detection unit and a side camera 112 as a side lane marker detection unit (and/or A rear camera 113) and a signal or information from a sensor 11 as a vehicle state detection unit are read, and a final command value is output to the drive control device 18. Each part constituting the lane change control unit 190 is expressed for convenience, and is actually realized by a program stored in the ROM.

The lane change target trajectory generator 191 is triggered by a lane change start signal to generate a lane change target trajectory. When an autonomous lane change is performed by the driving scene determination function described above or when a lane change instruction is given by the driver, a lane change start signal is input to the lane change target trajectory generator 191 . FIG. 7 is a diagram showing an example of generation processing executed by the lane change target locus generation unit 191. The upper diagram shows a scene in which the vehicle V changes lanes from the start position of lane L1 to the end position of lane L2. The plan view shown and the lower figure are graphs showing the target lateral position Y _ref and the target posture angle θ _ref in the scene shown in the upper figure. The posture angle θ is the yaw angle of the vehicle V with respect to the traveling direction.

The lane change target trajectory generation unit 191 stores in advance a reference distance from a start position to an end position and a reference lateral position at this distance. Generate a change target trajectory. For example, from the start position set according to the running speed to the end position, as shown in the distance-target lateral position Y _ref graph below, a transition curve that smoothly connects the start position and the end position, For example, it generates trigonometric functions, polynomial functions, clothoid curves, Bezier curves, and so on. Further, the target attitude angle θ _ref from the start position to the end position is obtained by comparing the target lateral position Y _ref in the distance-target lateral position Y _ref graph as shown in the distance-target attitude angle θ _ref graph below. can be obtained by differentiating with The lane change target trajectory generator 191 outputs the generated target lateral position Y _ref and target attitude angle θ _ref from the lane change start position to the end position to the first follow command value generator 193 .

The front lane marker estimation unit 192 captures the captured image of the front scanning area FA captured by the front camera 111, which is the front lane marker detection unit, and the side camera 112 (and/or the rear camera 113), which is the side lane marker detection unit. A front lane marker is extracted from the captured image of the lateral scanning area SA, and the lane marker of the lane in which the host vehicle is currently traveling and the lane marker of the adjacent lane to which the vehicle is to change lanes are recognized. FIG. 8A is a plan view showing an example of lane change control using the front camera 111 and the side camera 112. FIG. The host vehicle V1 can capture the lane markers LM1 and LM2 of the lane L1 in which it is currently traveling and the lane markers LM2 and LM3 of the adjacent lane L2 in the front scanning area FA of the front camera 111 and the side scanning area SA of the side camera 112. Therefore, the front lane marker estimation unit 192 recognizes the lane markers LM1, LM2, and L3, and calculates the road curvature ρ from the front lane marker information (i.e., the lateral position Y and the attitude angle θ) of the recognized front lane markers LM1, LM2, and L3. Then, the lane marker information Y, θ and road curvature ρ are output to the first follow-up command value generator 193 .

The side camera 112 (and/or the rear camera 113), which is a side lane marker detection unit, detects the lane marker of the lane in which the vehicle is currently traveling and the adjacent lane to which the vehicle is to change from the captured image of the side scanning area SA. lane markers. In FIG. 8A, the host vehicle V1 can capture the lane markers LM1 and LM2 of the lane L1 in which it is currently traveling and the lane markers LM2 and LM3 of the adjacent lane L2 in the side scanning area SA of the side camera 112. . The resulting side lane marker information (that is, the lateral position Y and the attitude angle θ) of the side lane markers LM1, LM2, and LM3 is output to the second follow command value generating section 195 and the road curvature estimating section 194. However, the side lane marker information is only the lane markers LM1, LM2, and LM3 detected in the side scanning area SA of the vehicle V1, and detected in the area ahead of the adjacent lane L2 where the vehicle V1 will change lanes from now on. Since it is not a lane marker, the curvature of the road cannot be detected directly from the captured image.

Therefore, the road curvature estimation unit 194 temporally accumulates the side lane marker information of the lane markers LM1, LM2, and LM3 detected in the side scanning area SA of the vehicle V1 by the side camera 112, and the accumulated side lane marker information is stored. The curvature ρ of the road is calculated from the lateral position Y and attitude angle θ of the lane marker information, and the vehicle speed and yaw rate of the own vehicle V1 detected by the sensor 11, which is the vehicle state detection unit, and is used by the first follow command value generation unit. 193. FIG. 9 is a diagram showing an example of estimation processing in the road curvature estimation unit 194. The lane marker information (lateral position Y and attitude angle θ, indicated by white circles in FIG. 9) located behind the vehicle V is accumulated. It corresponds to direction lane marker information.

The road curvature estimator 194 accumulates side lane marker information, which is the past detection result, by dead reckoning based on odometry based on the vehicle speed and yaw rate of the vehicle V. . Then, (1) using the accumulated latest lateral position Y information, regression analysis such as the method of least squares is used to perform function approximation to a polynomial function or the like, and the curvature of the road is estimated from this. Alternatively or in addition to this, (2) using the most recent attitude angle θ information accumulated, an average value of attitude angle variation with respect to distance may be obtained, and the curvature of the road may be estimated from this. Further alternatively or additionally, (3) estimating the curvature of the traveling locus T of the vehicle V shown in FIG. The curvature of the road may be estimated from this. Note that the method (3) of estimating the curvature of the road from the curvature of the traveled locus of the vehicle V is the above (1) where the function recent error due to the regression analysis is larger than a predetermined threshold, or the above (2) relative It may be adopted only when the variance of the average value of the angle change amount is larger than a predetermined threshold.

The first follow-up command value generator 193 generates the target lateral position Y _ref and the target attitude angle θ _ref generated by the lane change target trajectory generator 191 and the lateral position Y _sens and Y sens estimated by the forward lane marker estimator 192 . From the attitude angle θ _sens and the road curvature ρ _road , the first control command value for lane change to be actually output to the drive control device 18 is calculated. FIG. 10 is a diagram showing an example of generation processing executed by the first follow-up command value generator 193 and the second follow-up command value generator 195. A plan view showing a scene in which the lane is changed to the end position of L2. The lower figure is a circuit diagram showing an example of a control circuit that compensates for the lateral position Y, attitude angle θ, and road curvature ρ in the above scene.

In the control circuit diagram shown in the lower _drawing of _FIG . and a lateral position control command value that brings the difference ΔY close to zero is output by feedback control. Attitude angle compensator 198 calculates a difference Δθ between the target attitude angle θ _ref generated by lane change target trajectory generator 191 and the attitude angle θ _sens estimated by front lane marker estimator 192, and calculates the difference Δθ is output by feedback control of the control command value of the attitude angle that brings close to zero. A road curvature compensator 199 adds the road curvature ρ _road estimated by the forward lane marker estimator 192 to the control command value. As a result, the first follow-up command value generator 193 applies the road curvature estimated by the forward lane marker estimator 192 to the target lateral position Y _ref and target posture angle θ _ref generated by the lane change target trajectory generator 191 . A first control command value that follows the target trajectory with ρ _road added is output to the drive control device 18 .

Note that the road curvature ρ _road estimated by the front lane marker estimation unit 192 is sequentially updated over time when the front lane marker information can be detected by the front camera 111. When the state becomes undetectable, the last estimated road curvature ρ _road can be held and used to generate the first control command value of the first follow command value generation unit 193 until detection becomes possible. more preferred.

On the other hand, the second follow-up command value generator 195 generates the target lateral position Y _ref and the target attitude angle θ _ref generated by the lane change target trajectory generator 191 and the side camera 112 which is a side lane marker detector. (and/or the rear camera 113), and the road curvature _{ρ road} estimated by the road curvature estimator ₁₉₄ are actually output to the drive control device 18. A second control command value for lane change is calculated. That is, using the control circuit diagram shown in the lower diagram of FIG. A difference ΔY between _ref and the lateral position Y _sens detected by the side camera 112 is calculated, and a lateral position control command value that brings the difference ΔY closer to zero is output by feedback control. Attitude angle compensator 198 calculates a difference Δθ between target attitude angle θ _ref generated by lane change target trajectory generator 191 and attitude angle θ _sens detected by side camera 112, and calculates this difference Δθ. The control command value for the attitude angle that approaches zero is output by feedback control. The road curvature compensator 199 adds the road curvature ρ _road estimated by the road curvature estimator 194 to the control command value. As a result, the second follow-up command value generator 195 adds the road curvature estimated by the road curvature estimator 194 to the target lateral position Y _ref and target attitude angle θ _ref generated by the lane change target trajectory generator 191 . A second control command value that follows the target trajectory with ρ _road added is output to the drive control device 18 .

The command value switching unit 196 selectively switches between the first control command value generated by the first follow-up command value generation unit 193 and the second control command value generated by the second follow-up command value generation unit 195, Either one is output to the drive control device 18 . The control command value to be output to the drive control device 18 may be either the first control command value or the second control command value. When the camera 111 can recognize the lateral position, attitude angle, and road curvature of the front lane marker, the first control command value of the first follow command value generator 193 is output to the drive control device 18 . On the other hand, when the front lane marker information cannot be detected, that is, when the front camera 111 cannot recognize the lateral position, attitude angle, and road curvature of the front lane marker, the second control command of the second follow command value generation unit 195 Output the value to the drive controller 18 .

Although not particularly limited, the command value switching unit 196 switches the control command value to the low-pass It is preferable to perform a filtering process or a process of suppressing the amount of temporal change in the control command value.

<<Lane change control process>>
Next, lane change control processing according to the present embodiment will be described with reference to FIG. 11 . FIG. 11 is a flowchart showing an example of lane change control processing executed by the control device 19 of this embodiment. The travel control process described below is executed by the control device 19 at predetermined time intervals. In the following description, autonomous speed control and autonomous steering control are executed by the autonomous driving control function of the control device 19 so that the vehicle runs in the lane at the speed set by the driver. It is assumed that lane keep control is being performed to control the traveling position.

In step S1 of FIG. 11, the control device 19 determines whether or not a lane change control start signal has been input. The control device 19 repeats step S1 until a start signal for lane change control is input. On the other hand, when a signal for starting lane change control is input, the process proceeds to step S2.

When a start signal for lane change control is input, in step S2, the control device 19 determines whether or not the lane markers of the current lane and the adjacent lane to which the lane is to be changed can be detected by the front camera 111, which is the front lane marker detection unit. to judge whether For example, in the state shown in FIG. 8A, lane markers LM1, LM2, and LM3 of lanes L1 and L2 are included in forward scanning area FA by front camera 111, so it is determined that forward lane marker information can be detected. On the other hand, in the state shown in FIG. 8B where the attitude angle of the host vehicle V1 is large, the front camera 111 detects that the lane markers LM1 and LM2 of the lanes L1 and L2 are not included in the forward scanning area FA. Information is determined to be undetectable. If it is determined that the forward lane marker information can be detected, the process proceeds to step S3, and if it is determined that the forward lane marker information is undetectable, the process proceeds to step S6.

When it is determined that the forward lane marker information can be detected, in step S3, the first follow-up command value generation unit 193 generates a first control command value, and in subsequent step S4, lane change control is performed according to the first control command value. executed.

On the other hand, if it is determined that the front lane marker information cannot be detected as in the state shown in FIG. It is determined whether or not the lane markers of the middle lane and the adjacent lane to which the lane is to be changed can be detected. In the state shown in FIG. 8B, lane markers LM1 and LM2 of lanes L1 and L2 are not included in forward scanning area FA by front camera 111, but lane markers LM1 and L2 are not included in side scanning area SA by side camera 112. Since lane markers LM1, LM2, and LM3 are included, it is determined that side lane marker information can be detected. Then, in step S7, the second follow-up command value generating section 195 generates a second control command value, and in subsequent step S4, lane change control is executed according to the second control command value. Note that if it is determined in step S6 that the side lane marker information cannot be detected, the lane change control is terminated.

In step S5, it is determined whether or not the lane change has been completed. If not, the process returns to step S2, and the subsequent processes are repeated.

As described above, according to the vehicle travel control method and the travel control device 1 of the present embodiment, the current The road shape during travel, specifically the road curvature ρ, is estimated, and the estimated road shape, the target trajectory generated by the autonomous lane change control start command, and the detected running state of the own vehicle are combined. Based on this, a control command value for autonomous lane change control is generated. As a result, the lane marker after the lane change can be recognized when the lane is changed by the autonomous lane change control. As a result, autonomous lane change control can be continued even if forward lane marker information cannot be detected.

Further, according to the vehicle travel control method and travel control device 1 of the present embodiment, the shape of the road on which the vehicle is currently traveling is estimated based on the forward lane marker information detected in front of the vehicle V1, and the forward lane marker information is used as the shape of the road. and a second control command value estimated based on the side lane marker information. . This makes it possible to expand the range of lane markers that can be detected around the host vehicle V1.

Further, according to the vehicle cruise control method and the cruise control device 1 of the present embodiment, when the forward lane marker information can be detected, the autonomous lane change control is executed using the first control command value based thereon, When the forward lane marker information cannot be detected, the autonomous lane change control is executed using the second control command value based on the side lane marker information, so the autonomous lane change control is continued even when the forward lane marker information cannot be detected. can be run with

Further, according to the vehicle cruise control method and the cruise control device 1 of the present embodiment, when switching between the first control command value based on the forward lane marker information and the second control command value based on the side lane marker information, the control command Since the low-pass filter processing of the value or the processing of suppressing the amount of change in the control command value over time is performed, it is possible to suppress rapid fluctuations in the control command value at the time of switching.

Further, according to the vehicle cruise control method and the cruise control device 1 of the present embodiment, the road shape estimated based on the forward lane marker information is sequentially updated over time when the forward lane marker information can be detected. However, when the forward lane marker information changes from detectable to undetectable, the last estimated road shape is retained and used to generate the first control command value until detectable. As a result, the first control command value using the forward lane marker information with high reliability for estimating the road shape can be used as much as possible.

Further, according to the vehicle cruise control method and the cruise control device 1 of the present embodiment, the curvature of the road is estimated by regression analysis of the position information of the accumulated side lane marker information to a predetermined function. Alternatively, the curvature of the road is estimated by calculating the average value of the relative angle change amount per unit length from the accumulated relative angle information of the side lane marker information, so that the curvature of the road can be accurately estimated. can be done.

Further, according to the vehicle cruise control method and the cruise control device 1 of the present embodiment, the function recent error by regression analysis is larger than the predetermined threshold value, or the variance of the average value of the relative angle change amount is larger than the predetermined threshold value. In this case, the curvature of the traveled locus of the own vehicle is estimated from the vehicle speed and yaw rate included in the detected traveling state of the own vehicle, and the estimated curvature of the traveled locus of the own vehicle is estimated as the curvature of the road. Therefore, the curvature of the road can be estimated as accurately as possible.

Further, according to the vehicle cruise control method and the cruise control device 1 of the present embodiment, the target trajectory when the autonomous lane change control is executed includes the position and attitude at which the own vehicle starts changing lanes, The target trajectory is generated so as to smoothly connect the position and attitude at which the change ends, and the target value of the lateral position and the target value of the attitude angle when executing the autonomous lane change control are generated from the generated target trajectory. It is possible to change lanes on a smooth running trajectory that is comfortable to ride.

Further, according to the vehicle cruise control method and the cruise control device 1 of the present embodiment, when executing the autonomous lane change control from the current lane to the target lane, the target value of the lateral position and the actual Lateral position compensation processing is executed to reduce the deviation from the lateral position, attitude angle compensation processing is executed to reduce the deviation between the target attitude angle value and the actual attitude angle, and the estimated road shape is added. , can change lanes with precise control.

DESCRIPTION OF SYMBOLS 1... Travel control apparatus 11... Sensor 12... Vehicle position detection apparatus 13... Map database 14... Vehicle-mounted apparatus 15... Navigation apparatus 16... Presentation apparatus 17... Input device 18... Drive control apparatus 19... Control apparatus V1... Own vehicle V2... Leading vehicle L1: Running lane L2: Adjacent lane

Claims (12)

In a cruise control method for a vehicle that executes autonomous lane change control from the current lane to the target lane,
Detects the running state of the own vehicle,
estimating the shape of the road on which the vehicle is currently traveling based on the side lane marker information detected on the side of the vehicle;
generating a target trajectory for executing the autonomous lane change control based on the autonomous lane change control start command;
A vehicle running control method for generating a control command value for the autonomous lane change control based on the detected running state of the host vehicle, the estimated road shape, and the generated target trajectory. 2. The vehicle traveling according to claim 1, wherein said side lane marker information is information relating to lane markers that define lanes of a road, and includes position information of said lane markers and relative angle information of said lane markers with respect to said vehicle. control method. estimating the shape of the road on which the vehicle is currently traveling based on forward lane marker information detected in front of the vehicle;
the autonomous lane by selectively using a first control command value depending on the road shape estimated based on the forward lane marker information and a second control command value depending on the road shape estimated based on the side lane marker information; 3. The vehicle cruise control method according to claim 1, wherein change control is executed. executing the autonomous lane change control using the first control command value when the forward lane marker information is detectable;
4. The vehicle cruise control method according to claim 3, wherein the autonomous lane change control is executed using the second control command value when the forward lane marker information cannot be detected. 5. The vehicle according to claim 3 or 4, wherein when switching between the first control command value and the second control command value, low-pass filter processing of the control command value or processing for suppressing the temporal change amount of the control command value is executed. running control method. The road shape estimated based on the forward lane marker information is
If the forward lane marker information is detectable, it is updated sequentially with the passage of time,
When the forward lane marker information changes from detectable to undetectable, the last estimated road shape is retained and used to generate the first control command value until detectable. A running control method for a vehicle according to any one of the items. The road shape is a road curvature,
The vehicle cruise control method according to any one of claims 1 to 6, wherein the road curvature is estimated by regression analysis of the position information of the accumulated side lane marker information with a predetermined function. The road shape is a road curvature,
The vehicle according to any one of claims 1 to 6, wherein the road curvature is estimated by calculating an average value of relative angle change amounts per unit length from the accumulated side lane marker information relative angle information. running control method. The road shape is a road curvature,
estimating the road curvature by regression analysis of the position information of the accumulated side lane marker information to a predetermined function;
estimating the road curvature by calculating the average value of the relative angle change amount per unit length from the accumulated relative angle information of the side lane marker information;
estimating the curvature of the running trajectory of the own vehicle from the vehicle speed and yaw rate included in the detected running state of the own vehicle;
When the function recent error obtained by the regression analysis is larger than a predetermined threshold value, or when the variance of the average value of the relative angle change amount is larger than a predetermined threshold value, the estimated curvature of the traveled trajectory of the own vehicle is calculated as the road curvature. The vehicle travel control method according to any one of claims 1 to 6, wherein it is estimated that A target trajectory when executing autonomous lane change control is generated so as to smoothly connect a position and attitude at which the own vehicle starts changing lanes and a position and attitude at which the own vehicle finishes changing lanes,
The vehicle cruise control method according to any one of claims 1 to 9, wherein a target value of the lateral position and a target value of the attitude angle when executing the autonomous lane change control are generated from the generated target trajectory. When executing the autonomous lane change control from the current lane to the target lane,
performing lateral position compensation processing to reduce the deviation between the target value of the lateral position and the actual lateral position;
executing attitude angle compensation processing for reducing the deviation between the target value of the attitude angle and the actual attitude angle;
11. The vehicle running control method according to claim 10, wherein the estimated road shape is added. In a vehicle cruise control device comprising a processor for executing autonomous lane change control from a current lane to a target lane,
The processor
Detects the running state of the own vehicle,
estimating the shape of the road on which the vehicle is currently traveling based on the side lane marker information detected on the side of the vehicle;
generating a target trajectory for executing the autonomous lane change control based on the autonomous lane change control start command;
A vehicle running control device that generates a control command value for the autonomous lane change control based on the detected running state of the own vehicle, the estimated road shape, and the generated target trajectory.

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