JP2017132422A - Vehicle control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce discomfort given to an occupant during a lane change control.SOLUTION: A vehicle control system 100 is a vehicle control system for executing a lane change control causing an own vehicle to change the lane from a traveling lane to an adjacent lane, the system including: a section setting unit 15 for setting lane change sections composed of a first section provided in a traveling lane, a second section provided in an adjacent lane, and a third section interposed between the first section and the second section; and a lane change control unit 18 for executing a lane change control by steering the vehicle such that in the first section the vehicle is steered in the adjacent lane direction, in the second section the vehicle is steered in the traveling lane direction, and in the third section the vehicle is steered to travel straight in the longitudinal direction of the vehicle.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicle control system.

  A system that performs lane change control that automatically changes the lane in which the host vehicle travels is known. For example, in Patent Document 1, when changing the lane of the host vehicle, the first section that steers in the direction of the change destination lane adjacent to the lane on which the host vehicle travels, and the direction opposite to the direction of the change destination lane It is described that a second section for steering is provided and control is performed so that the time required for the second section is longer than the time required for the first section.

JP 2003-306161 A

  By the way, in a situation where it is required to enter the destination lane in a short time such as when the destination lane is congested, the time required to enter the destination lane by the technique described in Patent Document 1 If the control is performed so that the vehicle speed becomes short, the maximum value of the speed in the lateral direction becomes large, which may give the passenger an uncomfortable feeling.

  Therefore, an object of the present invention is to reduce the uncomfortable feeling given to the occupant during the lane change control.

  In order to solve the above-described problem, the present invention provides a vehicle control system that executes a lane change control for changing a vehicle from a traveling lane to an adjacent lane, the first section provided in the traveling lane, in the adjacent lane A second setting section, a section setting unit for setting a lane change section including a third section between the first section and the second section, steering the vehicle in the direction of the adjacent lane in the first section, A lane change control unit that performs lane change control by steering the vehicle in the direction of the travel lane in the section and steering the vehicle so that the vehicle travels straight in the front-rear direction of the vehicle in the third section.

  ADVANTAGE OF THE INVENTION According to this invention, the discomfort given to a passenger | crew can be reduced in the lane change control.

It is a block diagram which shows the vehicle control system which concerns on this embodiment. It is a block diagram which shows the example of a function structure of a steering angle target production | generation part. It is a figure which shows the example of a setting of a 1st area, a 2nd area, and a 3rd area. It is a block diagram which shows the example of a function structure of a steering angle target production | generation part. It is a figure which shows the production | generation of the steering angle target by a path | pass following control part. It is a figure which shows the example of the area setting in the case of accelerating during a lane change, and lane change control. It is a figure which shows the example of the area setting in the case of decelerating during a lane change, and lane change control. It is a figure which shows the example of the area setting in the case of accelerating during a lane change, and lane change control. It is a flowchart which shows the lane change control process in a vehicle control system. It is a figure which shows the example of the setting of a 1st area and a 2nd area. It is a figure which shows the example of a steering pattern. It is a figure which shows the example of the production | generation of the path by a path production | generation part. It is a figure which shows the change of the 1st area and 2nd area and steering angle which are set along the driving | running | working position of a vehicle. It is a figure which shows the example of the change of a 1st area and 2nd area set along the driving | running | working position of a vehicle, a steering angle, and a steering speed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a block diagram showing a vehicle control system of the present embodiment. A vehicle control system 100 shown in FIG. 1 is a system that is mounted on a vehicle and controls the traveling of the vehicle. The vehicle control system 100 is configured to be able to execute automatic driving of the vehicle. Automatic driving is vehicle control in which a vehicle travels to a destination without being operated by a driver. A well-known configuration can be adopted as a configuration for executing the automatic operation. The vehicle control system 100 can switch between automatic driving and manual driving in which the driver drives the vehicle. The vehicle control system 100 according to the present embodiment executes lane change control that changes the host vehicle from a traveling lane to an adjacent lane. The lane change control of the vehicle control system 100 is executed as part of automatic driving or as driving assistance for a driver during manual driving.

  As shown in FIG. 1, the vehicle control system 100 includes an ECU [Electronic Control Unit] 10.

  Connected to the ECU 10 are a GPS receiver 1, an external sensor 2, an internal sensor 3, a map database 4, a driving operation detector 5, and an actuator 6.

  The GPS receiver 1 measures the position of the vehicle (for example, the latitude and longitude of the vehicle) by receiving signals from three or more GPS satellites. The GPS receiver 1 transmits the measured vehicle position information to the ECU 10.

  The external sensor 2 is a detection device that detects the surrounding environment of the vehicle. The external sensor 2 includes a camera, a radar [Radar], or a rider [LIDAR: Laser Imaging Detection and Ranging]. For example, the camera is provided on the back side of the windshield of the vehicle and images the front of the vehicle. The camera may be provided on the back and side surfaces of the vehicle. The camera transmits imaging information around the vehicle to the ECU 10. The camera may be a monocular camera or a stereo camera. The stereo camera has two imaging units arranged so as to reproduce binocular parallax.

  The radar detects obstacles outside the vehicle using radio waves (for example, millimeter waves). The radar detects an obstacle by transmitting a radio wave around the vehicle and receiving the radio wave reflected by the obstacle. The radar transmits the detected obstacle information to the ECU 10. The rider detects an obstacle using light instead of radio waves. The rider transmits the detected obstacle information to the ECU 10.

  The internal sensor 3 is a detection device that detects the traveling state of the vehicle. The internal sensor 3 includes a vehicle speed sensor, an acceleration sensor, and a yaw rate sensor. The vehicle speed sensor is a detector that detects the speed of the vehicle. As the vehicle speed sensor, for example, a wheel speed sensor that is provided on a vehicle wheel or a drive shaft that rotates integrally with the wheel and detects the rotation speed of the wheel is used. The vehicle speed sensor transmits the detected vehicle speed information (wheel speed information) to the ECU 10.

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

  The map database 4 is a database provided with map information. The map database is formed in, for example, an HDD [Hard Disk Drive] mounted on the vehicle. The map information includes, for example, road position information, road shape information (for example, curves, straight line types, curve curvatures, etc.), and intersection and branch point position information.

  The driving operation detection unit 5 is a device that detects an operation on the vehicle by the driver of the vehicle. When the vehicle has a lane change control start button, the driving operation detection unit 5 detects an on operation and an off operation of the lane change control start button. Note that the operation for instructing the start of the lane change control need not be detected by the button, and may be detected by the start lever.

  The driving operation detection unit 5 includes a direction indicator detection unit. The direction indicator detector is provided for the direction indicator operation lever of the vehicle and detects the operation of the direction indicator operation lever by the driver. The direction indicator detector transmits the detected operation of the direction indicator operation lever to the ECU 10. In the present embodiment, the operation of the direction indicator operation lever may be triggered by the occurrence of a lane change trigger.

  The actuator 6 is a device that executes vehicle travel control. The actuator 6 includes at least a throttle actuator, a brake actuator, and a steering actuator. The throttle actuator controls the amount of air supplied to the engine (throttle opening) in accordance with a control signal from the ECU 10 to control the driving force of the vehicle. When the vehicle is a hybrid vehicle, in addition to the amount of air supplied to the engine, a control signal from the ECU 10 is input to a motor as a power source to control the driving force. When the vehicle is an electric vehicle, a control signal from the ECU 10 is input to a motor as a power source to control the driving force. The motor as the power source in these cases constitutes the actuator 6.

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

  The ECU 10 is an electronic control unit having a CPU [Central Processing Unit], a ROM [Read Only Memory], a RAM [Random Access Memory], a CAN [Controller Area Network] communication circuit, and the like. In the ECU 10, for example, various functions are realized by loading a program stored in the ROM into the RAM via the CAN communication circuit and executing the program loaded in the RAM by the CPU. The ECU 10 may be composed of a plurality of electronic control units. The ECU 10 has a function of executing automatic driving of the vehicle. The ECU 10 generates a travel plan for the vehicle in advance by a known method in order to execute automatic driving. The travel plan is data in which a position on the map of the vehicle is associated with a control target value (vehicle speed target, steering angle target) of the vehicle. The ECU 10 performs automatic driving of the vehicle according to the travel plan.

  Next, a functional configuration of the ECU 10 will be described. The ECU 10 includes a vehicle position recognition unit 11, a surrounding environment recognition unit 12, a traveling state recognition unit 13, a lane change trigger unit 14, a section setting unit 15, a steering angle target generation unit 16, a vehicle speed target generation unit 17, and a lane change control unit 18. Configure.

  The vehicle position recognition unit 11 recognizes the position of the vehicle on the map based on the position information of the GPS reception unit 1 and the map information of the map database 4. The position on the map of the vehicle is used by the vehicle control system 100 to determine the start of lane change control during automatic driving. The vehicle position recognition unit 11 uses the position information of a fixed obstacle such as a utility pole included in the map information of the map database 4 and the detection result of the external sensor 2 to detect the position of the vehicle by SLAM [Simultaneous Localization and Mapping] technology. May be recognized.

  The vehicle position recognition unit 11 recognizes the lateral position of the vehicle by a well-known image processing method based on a captured image (white line image) in front of the vehicle captured by an in-vehicle camera. The in-vehicle camera has a mounting position in the vehicle, and a range in which the camera captures an image is determined from the mounting position. Further, the positional relationship (positional relationship in plan view) between the camera mounting position and the center position of the vehicle is determined. For this reason, the vehicle position recognizing unit 11 can obtain the center position of the vehicle (lateral position of the vehicle) in the lane width direction from the positions of the two white lines on the left and right on the captured image of the camera. Instead of the camera, the white line may be recognized by a radar or a rider.

  Further, the vehicle position recognizing unit 11 can recognize whether or not the traveling lane is a joint path with a decrease in lane such as an interchange entrance when the lane change control is executed. For example, the vehicle position recognizing unit 11 can recognize whether or not the traveling lane is a joint channel based on an analysis of a captured image in front of the vehicle captured by an in-vehicle camera. In addition, the vehicle position recognition unit 11 can recognize the position of the vehicle on the map based on the position information of the GPS reception unit 1 and the map information of the map database 4 and can recognize whether the traveling lane is a junction. .

  The surrounding environment recognition unit 12 recognizes the surrounding environment of the vehicle based on the detection result of the external sensor 2. The surrounding environment includes the position of the obstacle with respect to the vehicle, the relative speed of the obstacle with respect to the vehicle, the moving direction of the obstacle with respect to the vehicle, and the like. The surrounding environment recognition unit 12 recognizes the surrounding environment of the vehicle by a known method based on the captured image of the camera, the obstacle information of the radar, or the obstacle information of the rider.

  The traveling state recognition unit 13 recognizes the traveling state of the vehicle based on the detection result from the internal sensor 3. The traveling state of the vehicle includes vehicle speed, vehicle acceleration, vehicle steering angle, and the like. The traveling state recognition unit 13 sends information related to the traveling state of the vehicle to the section setting unit 15, the steering angle target generation unit 16, the vehicle speed target generation unit 17, and the lane change control unit 18.

  The lane change trigger unit 14 generates a trigger that triggers the start of lane change according to a driver's instruction or automatic driving. The lane change trigger unit 14 sends a trigger to the section setting unit 15, the steering angle target generation unit 16, the vehicle speed target generation unit 17, and the lane change control unit 18.

  The lane change trigger unit 14 generates a trigger when, for example, the driving operation detection unit 5 receives a switch input for changing the lane by the driver. The lane change trigger unit 14 also triggers based on the recognition results by the vehicle position recognition unit 11, the surrounding environment recognition unit 12, and the travel state recognition unit 13 to determine that the vehicle travel position has reached a predetermined section. Or a trigger may be generated by detecting the absence of a vehicle in the vicinity.

  The section setting unit 15 sets a plurality of sections for executing predetermined lane change control in each. In the present embodiment, the section setting unit 15 is configured to change the lane including the first section provided in the traveling lane, the second section provided in the adjacent lane, and the third section between the first section and the second section. Set the interval. As will be described later, the first section is a section in which the vehicle is steered in the direction of the adjacent lane in the lane change control. The second section is a section in which the vehicle is steered in the direction of the traveling lane. The third section is a section in which the vehicle is steered so as to go straight in the front-rear direction of the vehicle (different from the direction in which the lane extends). The setting of each section will be described later with reference to FIG.

  The steering angle target generator 16 outputs a steering angle target based on the set lane change section. FIG. 2 is a block diagram illustrating an example of a functional configuration of the steering angle target generation unit 16A (16). As shown in FIG. 2, the steering angle target generator 16A includes a timer 16A-1 and a steering pattern generator 16A-2. The steering angle target generator 16 </ b> A generates a steering angle target based on the lane change section and lane change trigger set by the section setting unit 15.

  The timer 16A-1 sends an elapsed time after the lane change trigger is generated by the lane change trigger unit 14 to the steering pattern generation unit 16A-2. Note that the travel distance calculated by multiplying the elapsed time by the vehicle speed or the travel position in the lane traveling direction may be sent to the steering pattern generation unit 16A-2.

  The steering pattern generation unit 16A-2 refers to the steering pattern that defines the correspondence between the elapsed time (or travel distance or travel position) and the steering angle, and the elapsed time (or travel distance or travel position) from the timer 16A-1. ) To output a steering angle target. A plurality of steering patterns are stored in advance as a look-up table, for example.

  Next, an example of setting of the first section, the second section, and the third section and an example of generating a steering angle target by the section setting unit 15 of the present embodiment will be described with reference to FIG. As shown in FIG. 3, the section setting unit 15 is provided between the first section p11 provided in the travel lane, the second section p12 provided in the adjacent lane, and between the first section p11 and the second section p12. The third section p13 to be set is set.

  The steering angle target generator 16, the vehicle speed target generator 17, and the lane change controller 18 steer the vehicle C in the direction of the adjacent lane in the first section p11 (left steering in FIG. 3), as shown in the path P11. In the second section p12, the vehicle C is steered in the direction of the traveling lane (right steering in FIG. 3), and the lane change control is performed so that the vehicle C is steered so as to go straight in the front-rear direction of the vehicle C in the third section p13. To do.

  In FIG. 3, the horizontal axis is the travel position, and the direction of the adjacent lane (the direction toward the adjacent lane in the lane width direction) is the positive direction of the vertical axis. FIG. 3 shows the steering angle D11 and the lateral speed VS11 according to the traveling position in the traveling direction of the traveling lane (the extending direction of the traveling lane). The steering angle D11 is a steering angle target that is a target of the steering control of the vehicle C in FIG. Further, FIG. 3 shows the path P12, the steering angle D12, and the lateral speed VS12 when the third section is not set (that is, when predetermined lane change control is executed in each of the first section p01 and the second section p02). Shown for comparison.

  For example, the steering pattern generation unit 16A-2 outputs a steering angle target as indicated by the steering angle D11 in each of the first section, the third section, and the second section. That is, the lane change control is performed based on the steering angle D11, so that the vehicle C travels along the path P11. On the other hand, when the third section is not set, the vehicle C travels along the path P12 by performing lane change control based on the steering angle D12.

  As shown in the path P11, the third section p13 in which the vehicle C goes straight in the state where the lateral speed V11 is the maximum is provided, and the first section for increasing the lateral speed VS11 is shortened compared to the case where the third section is not set. By shortening the time until the lateral speed V11 becomes maximum, the vehicle C can enter the adjacent lane in a short time. Moreover, the maximum value of the lateral speed in the lane change control can be reduced by increasing the traveling time in the state where the lateral speed V11 is the maximum. As a result, it is possible to reduce the sense of discomfort of the occupant and give a sense of security.

  Next, an example of the second configuration of the steering angle target generator 16 will be described with reference to FIG. FIG. 4 is a block diagram illustrating an example of a functional configuration of the steering angle target generation unit 16B (16). As shown in FIG. 4, the steering angle target generation unit 16B includes a lane change distance calculation unit 16B-1, a path generation unit 16B-2, and a path following control unit 16B-3, and the lane set by the section setting unit 15 A steering angle target is generated based on the change section, the vehicle speed, and the lane change trigger.

  The lane change distance calculation unit 16B-1 calculates a lane change distance that is a distance necessary for the lane change by multiplying each lane change section set by the section setting unit 15 by the vehicle speed. The lane change distance calculation unit 16B-1 sends the calculated lane change distance to the path generation unit 16B-2.

  The path generation unit 16B-2 generates a path for the vehicle C to travel in each lane change section according to the lane change distance when the lane change trigger occurs. In other words, the path is a target trajectory traveled by the vehicle C whose lane is changed from the travel lane to the adjacent lane by the lane change control. The path generation unit 16B-2 sends the generated path information to the path tracking control unit 16B-3.

  Here, FIG. 3 will be referred to again as an example of the path generated by the path generation unit 16B-2. That is, the path P11 illustrated in FIG. 3 is an example of a path generated by the path generation unit 16B-2. As shown in the path P11, the path generated for the lane change control is the lane change section required for the vehicle C to change the lane (the sum of the lengths of the first section p11, the second section p12, and the third section p13). This is given as a smooth curve that moves only by the lateral movement distance necessary for changing the lane when the vehicle travels only.

The path following control unit 16B-3 generates a steering angle target based on the path generated by the path generation unit 16B-2, and outputs the generated steering angle target. FIG. 5 is a diagram illustrating generation of the steering angle target θ by the path following control unit 16B-3. The path follow-up control unit 16B-3 generates the steering angle target θ based on the positional relationship between the vehicle C and the path P. Specifically, the path following control unit 16B-3 generates the steering angle target θ by the following equation (1) based on the offset amount δ of the vehicle C with respect to the path P and the attitude angle β of the vehicle C with respect to the path P. To do.
θ = K1 · δ + K2 · β (1)
K1 and K2 are gains multiplied by δ and β, respectively, in order to make the vehicle C follow the path P. That is, the gain is a coefficient value that gives weight to each of σ and β, and may be a predetermined value set in advance. The gain may be a value that is changed according to the vehicle speed.

  With reference to FIG. 1 again, the remaining functional configuration of the ECU 10 will be described. The vehicle speed target generator 17 outputs a vehicle speed target in each lane change section. For example, the vehicle speed target generation unit 17 refers to a vehicle speed pattern that predetermines a correspondence relationship between the elapsed time (or travel distance or travel position) and vehicle speed after the lane change control trigger is generated and the control is started. To output the vehicle speed target. A plurality of vehicle speed patterns are stored in advance as a lookup table, for example. The vehicle speed target generation unit 17 outputs a vehicle speed target that the vehicle C accelerates during the lane change, for example, when the traveling lane is a combined passage with a lane decrease such as an interchange entrance.

  The lane change control unit 18 executes lane change control based on the steering angle target generated by the steering angle target generation unit 16 and the vehicle speed target generated by the vehicle speed target generation unit 17. Specifically, the lane change control unit 18 executes lane change control by causing the actuator 6 to perform throttle control, brake control, and steering control based on the steering angle target and the vehicle speed target. Note that the lane change control unit 18 may execute the lane change control based on only the steering angle target while keeping the vehicle speed constant.

  The lane change control unit 18 performs steering control of the vehicle C according to the first section, the second section, and the third section set by the section setting unit 15. The lane change control unit 18 steers the vehicle C in the direction of the adjacent lane in the first section. The lane change control unit 18 steers the vehicle C in the direction of the traveling lane in the second section. Further, the lane change control unit 18 steers the vehicle C so as to go straight in the front-rear direction of the vehicle C in the third section. That is, the lane change control unit 18 steers the vehicle C in the third section so as to maintain the direction of the vehicle C at the end point of the first section.

  Next, an example of setting of a lane change section by the section setting unit 15 and lane change control by the lane change control unit 18 will be described with reference to FIGS. When acceleration or deceleration is performed during the lane change, the section setting unit 15 changes the ratio of the first section, the second section, and the third section in the entire lane changing section based on the acceleration or the deceleration. .

  FIG. 6 is a diagram illustrating an example of section setting and lane change control when accelerating during a lane change, with respect to travel positions in the lane traveling direction in the first section p21, the second section p22, and the third section p23. A steering angle D21, a vehicle speed V21, and a lateral acceleration AS21 are shown. FIG. 6 also shows that the steering angle D22, the vehicle speed V22, the lateral acceleration AS22, and the acceleration are not accelerated during the lane change in the first zone p21, the second zone p32, and the third zone p33 when the vehicle is not accelerated during the lane change. The lateral acceleration AS23 is shown for comparison when steering is performed as in the case.

  The section setting unit 15 increases the ratio of the second section in the entire lane change section when accelerating during the lane change compared to the case where acceleration is not performed. That is, as shown in FIG. 6, the section setting unit 15 sets the second section p22 when performing acceleration longer than the second section p32 set when not performing acceleration.

  By changing the lane while accelerating, the speed in the third section becomes higher than that in the case of not accelerating. For this reason, when the length of a 2nd area does not change irrespective of the presence or absence of acceleration, the time required for the passage of a 2nd area becomes short. Then, when the lateral speed is changed from the maximum value to zero in order to complete the lane change in the second section where the passing time is shortened, the lateral acceleration accompanying the steering is accelerated as shown in the lateral acceleration AS23. It becomes larger than the case where it is not performed, and gives a sense of incongruity to the passengers. On the other hand, when accelerating during a lane change, the proportion of the second section p22 is increased compared to the case where acceleration is not performed, thereby preventing an increase in lateral acceleration as shown in the lateral acceleration AS21. it can. Thereby, a passenger's discomfort can be reduced.

  In addition, the section setting unit 15 is more likely to have the first position than the case where the vehicle lane recognition unit 11 recognizes that the travel lane is not a merge path when the travel lane is recognized as a merge path with lane reduction. Two sections may be set longer. In the combined flow path, there is a high possibility that the lane change is performed while accelerating, so that the lateral acceleration can be prevented from increasing by setting the second section longer and executing the lane change control.

  FIG. 7 is a diagram showing an example of section setting and lane change control when decelerating during lane change, with respect to the travel position in the lane traveling direction in the first section p41, the second section p42, and the third section p43. A steering angle D31 and a vehicle speed V31 are shown. FIG. 7 shows the steering angle D32 and the vehicle speed V32 for comparison in the first section p41, the second section p52, and the third section p53 when the vehicle does not decelerate during the lane change.

  The section setting unit 15 reduces the proportion of the second section in the entire lane change section when the vehicle decelerates during the lane change compared to the case where the deceleration is not performed. That is, as shown in FIG. 7, the section setting unit 15 sets the second section p42 when the deceleration is performed shorter than the second section p52 that is set when the deceleration is not performed.

  By changing the lane while decelerating, the speed in the second section becomes lower than when not decelerating. As a result, as indicated by the steering angle D31 in the second section p42, it is possible to steer along the adjacent lane by increasing the steering angle toward the traveling lane without increasing the lateral acceleration and when the vehicle does not decelerate. The traveling distance of the second section p42 can be shortened. Therefore, the lane change can be completed in a short distance without impairing the ride comfort of the occupant.

  FIG. 8 is a diagram illustrating an example of section setting and lane change control when accelerating during a lane change, with respect to travel positions in the lane traveling direction in the first section p61, the second section p62, and the third section p63. A steering angle D41 and a vehicle speed V41 are shown. FIG. 8 also shows, for comparison, the steering angle D42 and the vehicle speed V42 in the first section p71, the second section p72, and the third section p73 when acceleration is not performed during lane change.

  The section setting unit 15 increases the distance of the third section when accelerating during lane change compared to the case where acceleration is not performed. That is, as shown in FIG. 8, the section setting unit 15 sets the third section p63 when performing acceleration longer than the third section p73 set when not performing acceleration.

  If acceleration and steering are performed simultaneously while changing lanes, both the longitudinal and lateral accelerations act on the occupant at the same time, and the direction of the resultant acceleration vector, which is a combination of these accelerations, is the occupant's body. Therefore, it is difficult for the occupant to hold his / her body, and the occupant feels uncomfortable. On the other hand, when accelerating during the lane change, the first section p61 in which acceleration and steering are performed simultaneously by lengthening the third section p63 as compared to the third section p73 when acceleration is not performed. The second section p62 can be shortened. As a result, it is possible to reduce the discomfort of the occupant and improve the riding comfort.

  In addition, the section setting unit 15 is more likely to have the first position than the case where the vehicle lane recognition unit 11 recognizes that the travel lane is not a merge path when the travel lane is recognized as a merge path with lane reduction. You may set 3 sections long. In the combined flow path, there is a high possibility of changing the lane while accelerating. Therefore, the section where acceleration and steering are performed simultaneously can be shortened by setting the third section longer and executing the lane change control. . As a result, the ride comfort of the occupant can be improved.

  Next, a control process in the vehicle control system 100 will be described with reference to FIG. FIG. 9 is a flowchart illustrating a lane change control process in which the lane change from the travel lane to the adjacent lane is performed by the vehicle control system 100. The flowchart shown in FIG. 9 shows processing that is performed when a lane change trigger occurs.

  First, in step S1, the section setting unit 15 is a lane composed of a first section provided in the travel lane, a second section provided in the adjacent lane, and a third section between the first section and the second section. Set the change section. At this time, the steering angle target generator 16 may calculate a steering angle target in each section in advance. Similarly, the vehicle speed target generator 17 may calculate a vehicle speed target in each section in advance.

  In step S2, the steering angle target generation unit 16, the vehicle speed target generation unit 17, and the lane change control unit 18 execute lane change control for steering the vehicle C in the direction of the adjacent lane in the first section. The lane change control unit 18 executes lane change control in the first section based on the steering angle target output from the steering angle target generation unit 16 and the vehicle speed target output from the vehicle speed target generation unit 17.

  In step S <b> 3, the steering angle target generator 16, the vehicle speed target generator 17, and the lane change controller 18 execute lane change control that causes the vehicle C to travel straight forward and backward in the third section. The lane change control unit 18 executes lane change control in the third section based on the steering angle target and the vehicle speed target. The lane change control unit 18 executes lane change control for steering the vehicle C in the third section so as to maintain the direction of the vehicle C at the end point of the first section.

  In step S4, the steering angle target generation unit 16, the vehicle speed target generation unit 17, and the lane change control unit 18 execute lane change control for steering the vehicle C in the direction of the traveling lane in the second section. The lane change control unit 18 executes lane change control in the second section based on the steering angle target and the vehicle speed target.

  As described above, according to the vehicle control system 100 of the present embodiment, the first section provided in the traveling lane, the second section provided in the adjacent lane, and the first section between the first section and the second section. A lane change section consisting of three sections is set, the vehicle C is steered in the direction of the adjacent lane in the first section, the vehicle C is steered in the direction of the traveling lane in the second section, and the vehicle is moved in the front-rear direction in the third section. The lane change control is executed by steering the vehicle C so as to go straight. As a result, compared with the case where the third section is not set, the first section for increasing the lateral speed when changing the lane is shortened and the time until the lateral speed is maximized is shortened. Can enter the adjacent lane. In addition, since the time during which the lateral speed is maximum is increased, the maximum value of the lateral speed of the vehicle C in the lane change control can be reduced. As a result, it is possible to reduce the sense of discomfort of the occupant and give a sense of security.

  The present invention has been described in detail based on the embodiments. However, the present invention is not limited to the above embodiment. The present invention can be variously modified without departing from the gist thereof.

  The section setting unit 15 sets the first to third sections based on the travel distance, but may set each section based on the time required for traveling in each section.

  Further, the steering command from the lane change control unit 18 to the steering actuator is not limited to the command based on the steering angle, and may be a command based on the steering torque or the steering speed, for example.

  Further, when the acceleration / deceleration state changes during the execution of the lane change control, the lane change section may be reset when the acceleration / deceleration state changes.

  Next, as a reference example, an example of lane change control when the third section is not set will be described. That is, the section setting unit 15 may set only the first section and the second section without providing the third section. FIG. 10 is a diagram illustrating an example of setting the first section and the second section by the section setting unit 15. Here, as shown in the path P02 of FIG. 10, each section is set so that the lengths of the first section and the second section are the same distance. The section setting unit 15 sets the first section and the second section so that the travel distance of the second section is longer than the travel distance of the first section, as shown by a path P01 in FIG. The steering angle target generation unit 16 generates a steering angle target based on the section set by the section setting unit 15, and the lane change control unit 18 executes lane change control based on the generated steering angle target. In the first section, in the traveling lane, the vehicle C is steered in the direction of the adjacent lane adjacent to the left side (left steering in FIG. 10). In the second section, the vehicle C is steered in the direction of the traveling lane in the adjacent lane (right steering in FIG. 10).

  Further, in FIG. 10, the steering angle and the lateral speed are shown with the horizontal axis as the travel position and the direction of the adjacent lane as the positive direction of the vertical axis. The steering angle D01 and the lateral speed VS01 correspond to the path P01 set so that the travel distance of the second section is longer than the travel distance of the first section. Further, the steering angle D02 and the lateral speed VS02 correspond to the path P02 set so that the travel distance in the first section and the travel distance in the second section are the same.

  As shown in FIG. 10, the lane change control is performed so that the mileage of the second section is longer than the mileage of the first section, so that the vehicle C is gently adjusted with respect to the lane centerline of the adjacent lane. Overshooting when the lane is changed is prevented. Thereby, a passenger's sense of security is obtained.

  In addition, since the lane change control is performed so that the travel distance of the second section is longer than the travel distance of the first section, the section in which the lateral speed increases is shortened. The speed will reach a peak. Thereby, a travel lane can be left | separated in a shorter time. For example, when a preceding vehicle is approaching the front of the vehicle C in the traveling lane, the approaching to the preceding vehicle is prevented by the early departure of the traveling lane, and a sense of security can be given to the occupant.

FIG. 11 is a diagram illustrating an example of a steering pattern output by the steering pattern generation unit 16A-2. The steering pattern example shown in FIG. 11 is shown as a graph with the elapsed time (or travel distance) as the horizontal axis and the steering angle with the steering in the direction of the adjacent lane as the positive direction as the vertical axis. For example, the steering pattern generation unit 16A-2 may output the steering angle target with reference to a triangular wave steering pattern in which the second section is set longer than the first section as shown in FIG. Good. Further, the steering pattern generation unit 16A-2 may output a steering angle target with reference to a sinusoidal steering pattern in which the second section is set longer than the first section as shown in FIG. .
FIG. 12 is a diagram illustrating an example of path generation by the path generation unit 16B-2 when the section setting unit 15 does not set the third section. As shown in FIG. 12, the path for changing the lane is the lateral direction of the center line of the lane in which the vehicle C travels, where the traveling direction of the vehicle C is the x axis and the adjacent lane direction (lateral direction) is the y axis. As a position of y = 0, the vehicle C is given as a smooth curve that moves in the lateral direction by the lane width W when the vehicle C travels the lane change distance L. The lane change distance L is equal to the sum of the lengths of the respective lane change sections.

In the example shown in FIG. 12A, the lateral movement distance when traveling in the vehicle traveling direction by the movement distance X is Y, the lane change distance is L, and the lane width that is the lateral movement distance necessary for the lane change is W. Then, the path may be expressed by the following formula (2).
Y = 3W · (X / L) ^ 2 (X ≦ L / 3)
Y = W- (3W / 2). (1-X / L) ^ 2 (X> L / 3) (2)
The path shown in equation (2) is an example in which 1/3 of the length of the lane change distance L is the first section and 2/3 of the length of the lane change distance L is the second section. is there.

  Further, the path may be expressed by other higher-order polynomials. Further, the path generation unit 16B-2 may generate a path with reference to a lookup table that stores in advance the relationship between the movement distance X and the lateral movement distance Y in the vehicle traveling direction.

Further, as in the example illustrated in FIG. 12B, the path generation unit 16B-2 includes the lane center line CL1 (y = 0) before the lane change and the lane center line CL2 (y = W) before the lane change. On the other hand, a path may be generated by obtaining an internal dividing point corresponding to the movement distance X in the vehicle traveling direction. Points on lane center lines CL1 and CL2 corresponding to movement distance X in the vehicle traveling direction are point A (X0, Y0) and point B (X1, Y1), respectively, and the internal division ratio between point A and point B When an internal dividing point divided internally by R is a point C (X2, Y2), the internal division ratio R when x = X is expressed by the following equation (3).
R = 3 · (X / L) ^ 2 (X ≦ L / 3)
R = 1- (3/2) · (1-X / L) ^ 2 (X> L / 3) (3)
Then, the path generation unit 16B-2 generates a path by obtaining the coordinates of the point C by the following equation (4).
X2 = (1-R) X0 + R / X1
Y2 = (1-R) Y0 + R / Y1 (4)
In the formula (3), the following relationship is established.
X0 = X1 = X2 = X
Y0 = 0
Y1 = W

  Next, an example of setting the first section and the second section by the section setting unit 15 will be described with reference to FIGS. FIG. 13 is a diagram illustrating changes in the first and second sections and the steering angle set along the travel position of the vehicle. As shown in the example of FIG. 13, the section setting unit 15 sets the first section and the second section so that the absolute value of the steering angle in the second section is smaller than the absolute value of the steering angle in the first section. .

  For example, as shown in FIG. 13A, the section setting unit 15 sets the second section longer than the first section, so that the absolute value d1r of the steering angle in the second section is steered in the first section. Control that is smaller than the absolute value d1l of the angle is realized. Since the lateral acceleration generated when the lane is changed is substantially proportional to the steering angle, the lateral acceleration generated in the second section is suppressed by executing such control, so that the ride comfort of the occupant can be improved. .

  Further, as shown in FIG. 13B, the section setting unit 15 sets the second section longer than the first section, and further, the steering angle target generation unit 16, the vehicle speed target generation unit 17, and the lane change control. The unit 18 may execute the control so that the time to reach the maximum steering angle d2r in the second section is reduced and the vehicle travels for a certain period of time while being steered to the steering angle d2r. By being controlled in this way, the ride comfort of the occupant can be further improved.

  FIG. 14 is a diagram illustrating an example of changes in the first and second sections, the steering angle, and the steering speed that are set along the travel position of the vehicle. In FIG. 14, when the steering control indicated by the steering angle D3 is executed, the largest value among the absolute values of the steering speed in the first section is defined as the first section steering speed maximum value. That is, the first section steering speed maximum value is a larger value of the steering speeds sv3A and sv3B. Moreover, the largest value among the absolute values of the steering speed in the second section is defined as the second section steering speed maximum value. That is, the second section steering speed maximum value is a larger value of the steering speeds sv3C and sv3D.

  In such a case, the section setting unit 15 sets the second section longer than the first section, and further, the steering angle target generation unit 16, the vehicle speed target generation unit 17, and the lane change control unit 18 perform the second section steering. The control may be executed so that the first section steering speed maximum value becomes larger than the speed maximum value. Thus, the maximum value of the lateral acceleration generated in the first section can be reduced by increasing the steering speed in the first section and controlling the maximum steering angle faster. Thereby, a passenger | crew's sense of security can be improved.

DESCRIPTION OF SYMBOLS 1 ... GPS receiving part, 2 ... External sensor, 3 ... Internal sensor, 4 ... Map database, 5 ... Driving operation detection part, 6 ... Actuator, 11 ... Vehicle position recognition part, 12 ... Surrounding environment recognition part, 13 ... Running condition Recognizing unit, 14 ... Lane change trigger unit, 15 ... Section setting unit, 16, 16A, 16B ... Steering angle target generating unit, 16A-1 ... Timer, 16A-2 ... Steering pattern generating unit, 16B-1 ... Lane changing distance Calculation unit, 16B-2 ... path generation unit, 16B-3 ... path following control unit, 17 ... vehicle speed target generation unit, 18 ... lane change control unit, 100 ... vehicle control system.

Claims (1)

A vehicle control system that executes lane change control for changing a lane from a driving lane to an adjacent lane,
A section setting unit for setting a lane change section including a first section provided in the travel lane, a second section provided in the adjacent lane, and a third section between the first section and the second section. When,
The vehicle is steered in the direction of the adjacent lane in the first section, the vehicle is steered in the direction of the traveling lane in the second section, and the vehicle travels straight in the front-rear direction of the vehicle in the third section. A lane change control unit that executes the lane change control by steering the vehicle;
A vehicle control system comprising:

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