JP7408245B2 - Driving support method and driving support device - Google Patents

Description

The present invention relates to a driving support method and a driving support device.

Patent Document 1 below discloses that on a road including a driving lane in which the own vehicle is traveling and an adjacent lane adjacent to the driving lane, when the position of a stopped vehicle stopped in front of the own vehicle in the driving lane is recognized, A vehicle travel control device is described that stops the own vehicle at a target stop position corresponding to the position of the stopped vehicle.

Japanese Patent Application Publication No. 2016-112911

In automatic steering control, if the gain of steering angle feedback control is increased in order to avoid a stationary object in front of the host vehicle with a large steering angle, tracking performance becomes good, but vehicle behavior becomes unstable. On the other hand, if followability is sacrificed in order to stabilize vehicle behavior, the vehicle may not be able to travel along the target travel trajectory and may end up taking shortcuts or detours.
An object of the present invention is to improve path followability without reducing vehicle behavior stability when avoiding a stationary object in front of a host vehicle at a large steering angle using automatic steering control.

A driving support method according to an aspect of the present invention includes a process of determining whether or not the own vehicle has stopped in front of a stationary object in front of the own vehicle, and a process in which it is determined that the own vehicle has stopped in front of the stationary object. When the own vehicle is stopped, the steering amount is determined in a direction to avoid the stationary object according to a first profile that determines the amount of steering of the own vehicle with respect to the elapsed time during which the steering wheel of the own vehicle is turned. The steering wheel is steered until the steering amount reaches the first target steering amount, and after the steering amount reaches the first target steering amount, the own vehicle is started forward and the steering amount is calculated relative to the travel distance. The controller is caused to execute a process of controlling the host vehicle to overtake a stationary object by driving the host vehicle while steering the steering wheels according to the determined second profile.

According to the present invention, when a stationary object in front of the own vehicle is avoided by automatic steering control at a large turning angle, route followability can be improved without reducing vehicle behavior stability.

1 is a schematic configuration diagram of a driving support device according to an embodiment. FIG. 2 is an explanatory diagram of an example of a situation in which the driving support method of the embodiment is implemented. FIG. 3 is an explanatory diagram of an example of a time-curvature profile. FIG. 3 is an explanatory diagram of an example of a distance-curvature profile. FIG. 2 is an explanatory diagram of an example of a travel trajectory in which lanes are changed according to a distance-curvature profile. FIG. 1 is a block diagram showing an example of a functional configuration of a driving support device according to an embodiment. FIG. 2 is an explanatory diagram of an example of conditions for implementing the driving support method according to the embodiment. FIG. 3 is an explanatory diagram of an example of a time-curvature profile of turning to the right. FIG. 3 is an explanatory diagram of an example of a time-curvature profile of left steering. FIG. 3 is an explanatory diagram of an example of setting a time-curvature profile according to a lane change section distance. FIG. 3 is an explanatory diagram of an example of a distance-curvature profile. FIG. 3 is an explanatory diagram of a setting example of an example of a distance-curvature profile according to lane width. FIG. 3 is an explanatory diagram of an example of a method of calculating a switching point distance. FIG. 2 is an explanatory diagram of an example of a method for setting a target curvature according to road curvature. FIG. 3 is an explanatory diagram of an example of setting the attitude angle of the own vehicle at a switching point. FIG. 7 is an explanatory diagram of a setting example of an example of a distance-curvature profile according to a lane change section distance. It is a flow chart of an example of the driving support method of an embodiment.

Embodiments of the present invention will be described below with reference to the drawings. Note that each drawing is schematic and may differ from the actual drawing. In addition, the embodiments of the present invention shown below illustrate devices and methods for embodying the technical idea of the present invention. is not limited to the following: The technical idea of the present invention can be modified in various ways within the technical scope defined by the claims.

(composition)
Please refer to FIG. The own vehicle 1 includes a driving support device 10 that provides driving support for the own vehicle 1. Driving support by the driving support device 10 includes automatic driving control that automatically drives the own vehicle 1 without the driver's involvement based on the driving environment around the own vehicle 1, and driving of the own vehicle 1 by the driver. It may include driving support control to support the driver.
The driving support control may include running control that automatically controls at least one of a steering device, a drive device, and a braking device of the host vehicle.

The driving support device 10 includes an object sensor 11, a vehicle sensor 12, a positioning device 13, a map database 14, a navigation device 15, a communication device 16, a controller 17, and an actuator 18. In the drawings, the map database is expressed as "map DB".
The object sensor 11 is one of a plurality of different types that detect objects around the own vehicle 1, such as a laser radar, a millimeter wave radar, a camera, and a LIDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging) mounted on the own vehicle 1. Equipped with an object detection sensor.

The vehicle sensor 12 is mounted on the own vehicle 1 and detects various information (vehicle signals) obtained from the own vehicle 1. The vehicle sensors 12 include, for example, a vehicle speed sensor that detects the traveling speed (vehicle speed) of the own vehicle 1, a wheel sensor that detects the rotation speed and amount of rotation of each tire included in the own vehicle 1, and a wheel sensor that detects the rotation speed and amount of rotation of each tire of the own vehicle 1, and a A 3-axis acceleration sensor (G sensor) that detects acceleration (including deceleration), a steering angle sensor that detects steering angle (including turning angle), a gyro sensor that detects the angular velocity generated in the vehicle 1, and a yaw rate. The system includes a yaw rate sensor, an accelerator sensor that detects the accelerator opening of the own vehicle, and a brake sensor that detects the amount of brake operation by the driver.

The positioning device 13 includes a global positioning system (GNSS) receiver, and measures the current position of the own vehicle 1 by receiving radio waves from a plurality of navigation satellites. The GNSS receiver may be, for example, a Global Positioning System (GPS) receiver. The positioning device 13 may be, for example, an inertial navigation device.

The map database 14 may store high-precision map data (hereinafter simply referred to as "high-precision map") suitable as a map for automatic driving. The high-precision map is map data with higher precision than navigation map data (hereinafter simply referred to as "navigation map"), and includes information on a lane-by-lane basis that is more detailed than information on a road-by-road basis.

For example, a high-precision map contains lane-by-lane information: lane node information that indicates the reference point on the lane reference line (for example, the center line within the lane), and lane link information that indicates the mode of the lane section between lane nodes. including.
The information on the lane node includes the identification number of the lane node, the position coordinates, the number of connected lane links, and the identification number of the connected lane link. The lane link information includes the identification number of the lane link, the width of the lane, the type of lane boundary line, the shape of the lane, the shape of the lane marking line, and the shape of the lane reference line.

Since the high-precision map includes node and link information for each lane, it is possible to specify the lane in which the host vehicle 1 is traveling on the travel route. The high-precision map has coordinates that can express the position in the direction of extension and width of the lane. A high-precision map has coordinates (for example, longitude, latitude, and altitude) that can represent a position in a three-dimensional space, and lanes and the above-mentioned features may be described as shapes in a three-dimensional space.

The navigation device 15 recognizes the current position of the host vehicle 1 using the positioning device 13 and the like. Further, the destination of the own vehicle 1 is set according to the operation of the occupant, and a planned travel route for each road from the current position to the destination is calculated based on the map information in the map database 14.
The navigation device 15 outputs information on the calculated planned travel route to the controller 17. Further, the navigation device 15 provides route guidance to the occupant according to the calculated planned travel route.
The communication device 16 performs wireless communication with a communication device external to the vehicle 1 . The communication method used by the communication device 16 may be, for example, wireless communication using a public mobile telephone network, vehicle-to-vehicle communication, road-to-vehicle communication, or satellite communication.

The controller 17 is an electronic control unit (ECU) that performs driving support control of the own vehicle 1. The controller 17 includes a processor 21 and peripheral components such as a storage device 22. The processor 21 may be, for example, a CPU (Central Processing Unit) or an MPU (Micro-Processing Unit).
The storage device 22 may include a semiconductor storage device, a magnetic storage device, an optical storage device, or the like. The storage device 22 may include memories such as a register, a cache memory, a ROM (Read Only Memory) used as a main storage device, and a RAM (Random Access Memory).

The functions of the driving support device 10 described below are such that, for example, the processor 21 executes a computer program stored in the storage device 22, the object sensor 11, the vehicle sensor 12, the positioning device 13, the map database 14, the navigation device 15, and the like. This is realized by cooperating with the communication device 16.

Note that the controller 17 may be formed of dedicated hardware for executing each information process described below.
For example, the controller 17 may include a functional logic circuit set in a general-purpose semiconductor integrated circuit. For example, the controller 17 may include a programmable logic device (PLD) such as a field-programmable gate array (FPGA).

The actuator 18 operates the steering mechanism, accelerator opening, and braking device of the own vehicle in response to a control signal from the controller 17 to generate the vehicle behavior of the own vehicle. The actuator 18 includes a steering actuator, an accelerator opening actuator, and a brake control actuator. The steering actuator controls the steering direction and amount of steering of the steering wheels of the own vehicle. The steering actuator may be, for example, a steering assist motor that provides steering assist force in an electric power steering system, or may be a steering assist motor that provides steering assist force in an electric power steering system, or a steering actuator that rotates the steered wheels in a steering-by-wire system in which the steering wheel and the steered wheels are mechanically separated. It may be a steering motor for steering.
The accelerator opening actuator controls the accelerator opening of the host vehicle. The brake control actuator controls the braking operation of the brake device of the own vehicle 1.

Next, an example of driving support control by the driving support device 10 of the embodiment will be described with reference to FIGS. 2A, 2B, 2C, and 2D.
FIG. 2A shows an example of a situation in which the driving support method according to this embodiment is implemented. The driving support method according to the present embodiment is executed when the host vehicle 1 stops in front of the stationary object 100 in front of the host vehicle 1.
For example, assume that the own vehicle 1 stops in front of a parked vehicle 100 in front of the own vehicle 1 while executing automatic driving control.

In this case, in the section of length DL between the host vehicle 1 and the parked vehicle 100, the driver must avoid the parked vehicle 100 by changing lanes from the driving lane 102 of the host vehicle 1 to the adjacent lane 103, as shown by a broken line 101. For example, the own vehicle 1 cannot continue traveling. Hereinafter, the section of length DL between host vehicle 1 and parked vehicle 100 will be referred to as a "lane change section", and the length DL will be referred to as "lane change section distance".

When the lane change section distance DL is short, it is necessary for the own vehicle 1 to avoid the parked vehicle 100 with a large turning curvature (that is, with a large turning angle). In this case, if the gain of the feedback control of the turning curvature (or turning angle) is increased to increase the turning curvature, the followability becomes good, but the vehicle behavior becomes unstable. On the other hand, if followability is sacrificed in order to stabilize vehicle behavior, the vehicle may not be able to travel along the target travel trajectory and may end up taking shortcuts or detours.

Further, when avoiding the parked vehicle 100 by forward gaze point control that performs steering control according to the amount of deviation between the forward gaze point and the target traveling trajectory, tracking performance can be improved by shortening the forward gaze point distance. However, in this case as well, vehicle behavior becomes unstable. On the other hand, if the forward gaze point distance is increased in order to stabilize vehicle behavior, the vehicle may not be able to travel along the target travel trajectory and may end up taking shortcuts or detours.

Therefore, in the driving support method of the present embodiment, the amount of turning of the own vehicle 1 is controlled based on a profile of a target turning amount (for example, a turning curvature or a turning angle) designed in advance.
Specifically, first, when the own vehicle 1 is stopped in front of the parked vehicle 100, the turning amount is calculated as the amount of turning with respect to the elapsed time during which the steering wheels of the own vehicle are turned, as shown in FIG. 2B. In accordance with the time-curvature profile that determines the curvature ρc, the steering wheels are steered in a direction to avoid the parked vehicle 100 until the turning curvature ρc (steering amount) reaches the first target curvature ρmax (first target turning amount). . For example, the steering wheel may be steered to the right on a road where driving on the left is mandatory, and the steering wheel may be steered to the left on a road where driving is mandatory on the right.

In the following description, the turning curvature when turning to the right is assumed to be a positive value, and the turning curvature when turning to the left is assumed to be a negative value. The magnitude of the first target curvature ρmax (that is, the absolute value |ρmax|) may be, for example, the magnitude of the turning curvature at full steering.
The turning curvature ρ can be calculated using the following (Equation 1) based on the host vehicle speed Vh and the steering angle δ.
ρ=1/{L(1+A・Vh ² )}×δ/N (Formula 1)
Here, L: wheel base of the host vehicle, A: stability factor (positive constant) determined according to the vehicle, and N: steering gear ratio.
Next, after the turning curvature ρc reaches the first target curvature ρmax, the own vehicle 1 is started forward, and the own vehicle follows a distance-curvature profile that determines the change in the turning curvature ρc with respect to the travel distance, as shown in FIG. 2C. Turn the steering wheel while running the vehicle. The shape of the distance-curvature profile will be described later.

As a result, the host vehicle 1 travels along the travel trajectory 101 shown in FIG. 2D and changes lanes from the lane 102 to the adjacent lane 103 so as to overtake (avoid) the parked vehicle 100.
In this way, in the driving support method of this embodiment, the amount of steering of the own vehicle 1 is controlled based on a profile designed in advance. In other words, the steering amount is controlled by feedforward control.
Therefore, even when the own vehicle 1 is driven with a large turning curvature, the stability of vehicle behavior does not deteriorate. Thereby, route followability can be improved without reducing vehicle behavior stability.
Note that the time-curvature profile and the distance-curvature profile are examples of a "first profile" and a "second profile" described in the claims, respectively.

Next, with reference to FIG. 3, the functions of the driving support device 10 will be explained in detail. In addition to the map database 14 and actuator 18 described above, the driving support device 10 includes an avoidance support determination section 30, a travel distance determination section 31, a forward gaze point control section 32, a time-curvature profile generation section 33, and a distance determination section 30. - It includes a curvature profile generation section 34, a control selection section 35, a steering angle control section 36, a vehicle speed setting section 37, and a vehicle speed control section 38.

The avoidance support determination unit 30 determines whether or not to execute avoidance support control to avoid the stationary object using the driving support method of the present embodiment when the host vehicle 1 stops in front of a stationary object in front of the host vehicle 1. judge.
See FIG. 4. The avoidance support determining unit 30 determines whether the own vehicle 1 has stopped based on the detection result of the vehicle sensor 12.
When it is determined that the host vehicle 1 has stopped, the avoidance support determination unit 30 determines whether the host vehicle 1 has stopped in front of the parked vehicle 100, which is a stationary object in front of the host vehicle 1, based on the detection result of the object sensor 11. Determine whether or not.

For example, it is determined whether the inter-vehicle distance between the own vehicle 1 and the parked vehicle 100, that is, the length of the lane change section (lane change section distance DL), is within a predetermined threshold range (more than or equal to the threshold Dt2 and less than the threshold Dt1). judge.
When the lane change section distance DL is greater than or equal to the threshold value Dt2 and less than the threshold value Dt1, the avoidance support determination unit 30 determines to execute the avoidance support control. When the lane change section distance DL is less than the threshold value Dt2 or greater than the threshold value Dt1, the avoidance support determination unit 30 determines not to perform the avoidance support control.

The threshold value Dt1 may be appropriately set according to an inter-vehicle distance at which the vehicle behavior does not become unstable due to an increase in turning curvature even if steering control is performed to avoid the parked vehicle 100 by, for example, forward gaze point control.
When the lane change section distance DL is equal to or greater than the threshold value Dt1, for example, the driving support device 10 controls the amount of steering to avoid the parked vehicle 100 by controlling the forward gaze point.

On the other hand, the threshold value Dt2 may be appropriately set, for example, depending on the inter-vehicle distance at which it is no longer possible to avoid the parked vehicle 100 even if the own vehicle 1 is fully steered while stopped in front of the parked vehicle 100.
When the lane change section distance DL is less than the threshold value Dt2, for example, the driving support device 10 stops the automatic driving control of the host vehicle 1 and notifies the driver to continue driving the host vehicle 1 manually.

The mileage determination unit 31 determines the mileage of the own vehicle 1 based on the detection result of the vehicle sensor 12.
The forward gaze point control unit 32 controls the amount of steering of the own vehicle 1 through forward gaze point control. Specifically, the forward gaze point control unit 32 outputs the target turning amount of the vehicle 1 according to the amount of deviation between the forward gaze point set in front of the vehicle 1 and the target travel trajectory.

When controlling the turning amount of the own vehicle 1 by forward gaze point control, the avoidance support determination section 30 determines the target steering amount (target turning curvature) output from the forward gaze point control section 32 to the control selection section 35. ρt) and outputs a selection instruction signal instructing to select and output it to the steering angle control unit 36.
On the other hand, when executing the avoidance support control, the avoidance support determination unit 30 selects the target steering amount (target turning curvature ρt) output from the time-curvature profile generation unit 33 to the control selection unit 35. A selection instruction signal is output that instructs the output to the steering angle control section 36.
The control selection unit 35 selects the target steering amount from the forward gaze point control unit 32 and the target steering amount from the time-curvature profile generation unit 33 based on the selection instruction signal from the avoidance support determination unit 30. and output it.
The steering angle control unit 36 controls the steering angle of the steered wheels by driving the steering actuator so as to achieve the target steering amount output from the control selection unit 35.

The time-curvature profile generation unit 33 generates the above-described time-curvature profile when the avoidance support determination unit 30 determines to execute avoidance support control. The time-curvature profile generation unit 33 outputs a target turning curvature ρt according to the elapsed time from the start time of the avoidance support control according to the time-curvature profile.

FIG. 5A shows an example of a time-curvature profile for a right turn. A solid line 40 is a profile (hereinafter referred to as a "stationary steering profile") for stationary steering in a direction to avoid the parked vehicle 100 when the own vehicle 1 is stopped.
The fixed profile 40 may include, for example, a first section S1 from time 0 to time t1, and a second section S2 from time t1 to time t2 following the first section S1.

The first section S1 is a section in which the turning curvature ρc increases (that is, the absolute value |ρc| increases), for example, at a constant rate of change (in other words, at a constant steering speed) up to the first target curvature ρmax.
The second section S2 is a section in which the turning curvature ρc maintains the first target curvature ρmax (that is, a section in which the turning curvature ρc is fixed).
Note that the rate of change of the turning curvature ρc in the first section S1 can be changed as appropriate, and is set so as not to exceed the upper limit of the steering speed (for example, the upper limit of the steering speed by the steering actuator).

Note that the time-curvature profile generation unit 33 converts the turning curvature ρc of the own vehicle 1 before the start of stationary turning, for example, the turning curvature ρc at the time when the own vehicle 1 is stopped in front of the parked vehicle 100 by forward gaze point control, to the forward turning curvature ρc. It may also be acquired from the gaze point control unit 32.
The time-curvature profile generation unit 33 transforms the stationary steering profile 40 so that the turning curvature ρc at the start time of the first section S1 becomes the turning curvature ρc of the own vehicle 1 before the stationary steering starts.

A dashed-dotted line 41 is a profile (hereinafter referred to as a "cancellation profile") for canceling the stationary steering based on the stationary steering profile 40 and returning the turning curvature ρc to the curvature before starting stationary steering.
Cancellation profile 41 may also include two sections. In the first preceding section, starting from the cancellation start time t3, the turning curvature ρc decreases at a constant rate of change (that is, the absolute value |ρc| decreases) up to the curvature before the start of stationary cutting. The cancellation start time t3 can be changed as appropriate.

The subsequent second section starts from time t4 when the turning curvature ρc reaches the curvature before the start of stationary steering. In the second section, the turning curvature ρc maintains the curvature before the start of stationary turning.
FIG. 5B shows an example of a time-curvature profile for left steering. A solid line 42 is a fixed profile.
Similar to the stationary steering profile 40 for right steering, the stationary steering profile 42 includes, for example, a first section S1 from time 0 to time t1, and a second section from time t1 to time t2 following the first section S1. S2 may be included.

In the first section S1, for example, the turning curvature ρc decreases (that is, the absolute value |ρc| increases) at a constant rate of change up to the first target curvature ρmin, which is a negative value. In the second section S2, the turning curvature ρc maintains the first target curvature ρmin.
The rate of change of the turning curvature ρc in the first section S1 can be changed as appropriate, and is set so as not to exceed the upper limit of the steering speed (for example, the upper limit of the steering speed by the steering actuator).

As in the case of the time-curvature profile for turning to the right, the time-curvature profile generation unit 33 determines that the turning curvature ρc at the time when the first section S1 starts is the turning curvature ρc of the host vehicle 1 before the start of steering. The fixed cut profile 42 is modified so that
A dashed line 43 is a cancellation profile. Cancellation profile 43 may also include two sections.
In the first preceding section, starting from the cancellation start time t3, the turning curvature ρc increases at a constant rate of change up to the curvature before the start of stationary cutting (that is, the absolute value |ρc| decreases). The cancellation start time t3 can be changed as appropriate.
The subsequent second section starts from time t4 when the turning curvature ρc reaches the curvature before the start of stationary steering. In the second section, the turning curvature ρc maintains the curvature before the start of stationary turning.

See FIG. 5C. The time-curvature profile generation unit 33 may change the first target curvature ρmax as appropriate. For example, the time-curvature profile generation unit 33 may set the first target curvature ρmax according to the lane change section distance DL.
Specifically, the time-curvature profile generation unit 33 may set the first target curvature ρmax such that the shorter the lane change section distance DL, the greater the absolute value of the first target curvature ρmax. The same applies to the first target curvature ρmin.

See FIG. 3. While the time-curvature profile generation section 33 outputs the target turning curvature ρt according to the time-curvature profile in the first section S1 and the second section S2, the avoidance support determination section 30 instructs the control selection section 35 to - Output a selection instruction signal instructing to select the target turning curvature ρt output from the curvature profile generation section 33 and output it to the turning angle control section 36.
The steering angle control unit 36 drives the steering actuator to steer the steered wheels so that the turning curvature ρc of the own vehicle 1 becomes the target turning curvature ρt output from the time-curvature profile generation unit 33. Control the corners.

As a result, when turning to the right, the turning curvature ρc of the own vehicle 1 changes to the first target curvature ρmax while the own vehicle 1 is stopped. When turning leftward, the turning curvature ρc of the own vehicle 1 changes to the first target curvature ρmin while the own vehicle 1 is stopped.
In the following description, for the sake of simplicity, only the case where the own vehicle 1 is steered to the right while stopped will be described. When the own vehicle 1 is turned to the left in a stopped state, the same applies except that the steering direction in the following description is the opposite direction.

When the turning curvature ρc of the own vehicle 1 reaches the first target curvature ρmax, the avoidance support determination unit 30 can start the own vehicle 1 based on the surrounding environment of the own vehicle 1 detected by the object sensor 11. Determine whether or not.
For example, the avoidance support determining unit 30 determines whether there is a moving object moving on the adjacent lane 103 approaching the host vehicle 1 and an obstacle on the adjacent lane 103 in front of the host vehicle 1. . When these moving objects and obstacles do not exist, the avoidance support determination unit 30 determines that it is possible to start the host vehicle 1, and when these moving objects and obstacles do not exist, the avoidance support determination unit 30 starts the host vehicle 1. It is determined that it is not possible.

If it is determined that the own vehicle 1 can be started, the avoidance support determining section 30 outputs a start instruction signal for starting the own vehicle 1 to the distance-curvature profile generating section 34.
Upon receiving the start instruction signal, the distance-curvature profile generation section 34 generates the above-mentioned distance-curvature profile.
The distance-curvature profile generation unit 34 reads the travel distance determined by the travel distance determination unit 31, and outputs the target turning curvature ρt according to the distance-curvature profile.

FIG. 6 shows an example of a distance-curvature profile. The distance-curvature profile is, for example, a third section S3 from distance 0 to distance d1, a fourth section S4 from distance d1 to distance d2, a fifth section S5 from distance d2 to distance d3, and distance It may include a sixth section S6 from distance d3 to distance d4 and a seventh section S7 from distance d4 to distance d5.
The third section S3 is a section in which the turning curvature ρc maintains the first target curvature ρmax (that is, a section in which the turning curvature ρc is fixed).

The subsequent fourth section S4 is a section in which the turning curvature ρc decreases from the first target curvature ρmax to zero in proportion to the travel distance (that is, at a constant rate of change). In the fourth section S4, the absolute value of the turning curvature ρc decreases.
The subsequent fifth section S5 is a section in which the turning curvature ρc decreases from zero to the second target curvature ρ6 in proportion to the travel distance (that is, at a constant rate of change). The direction of the second target curvature ρ6 is opposite to the direction of the first target curvature ρmax (that is, the sign of the first target curvature ρmax and the sign of the second target curvature ρ6 are different), and in the fifth section S5, the first section S1 The turning curvature ρc changes in a direction opposite to the direction of change, and the absolute value of the turning curvature ρc increases.

The subsequent sixth section S6 is a section in which the turning curvature ρc maintains the second target curvature ρ6 (that is, a section in which the turning curvature ρc is fixed).
The subsequent seventh section S7 is a section in which the turning curvature ρc increases from the second target curvature ρ6 to zero in proportion to the traveling distance (that is, at a constant rate of change). In the seventh section S7, the absolute value of the turning curvature ρc decreases.
Note that the rate of change of the turning curvature ρc in the fourth section S4, the fifth section S5, and the seventh section S7 can be changed as appropriate. For example, the upper limit of the turning speed (for example, the turning speed by the steering actuator (upper limit) is set so as not to exceed.

While the distance-curvature profile generation section 34 outputs the target turning curvature ρt according to the distance-curvature profile in the third section S3 to the seventh section S7, the avoidance support determination section 30 tells the control selection section 35 to: A selection instruction signal instructing to select the target turning curvature ρt outputted from the distance-curvature profile generation section 34 and output it to the steering angle control section 36 is output.

The steering angle control unit 36 drives the steering actuator to steer the steered wheels so that the turning curvature ρc of the own vehicle 1 becomes the target turning curvature ρt output from the distance-curvature profile generation unit 34. Control the corners.
Further, the vehicle speed control section 38 drives the accelerator opening actuator and the brake control actuator based on the vehicle speed set by the vehicle speed setting section 37, so that the own vehicle 1 is controlled while being steered according to the distance-curvature profile. Control vehicle speed.

As a result, as shown in FIG. 2D, the host vehicle 1 travels along the travel trajectory 101 and changes lanes from the lane 102 to the adjacent lane 103 so as to overtake (avoid) the parked vehicle 100. do.
Note that the vehicle speed setting unit 37 sets the vehicle speed to be higher when a following vehicle is approaching from behind on the path after overtaking the parked vehicle 100 (for example, in the adjacent lane 103) than when the following vehicle is not approaching. may be set.

The distance-curvature profile generation unit 34 generates a distance-curvature profile so that the attitude angle of the own vehicle 1 before the lane change (that is, while stopped before starting) is equal to the attitude angle of the own vehicle 1 after the lane change. may be set. Note that the attitude angle of the host vehicle 1 is the azimuth angle of the vehicle body direction of the host vehicle 1.
See FIG. 6. In order to make the attitude angle before the lane change equal to the attitude angle after the lane change, the sum of the areas of the distance-curvature profiles in the third section S and the fourth section S4 (the diagonally hatched area) and the fifth The sum of the area of the distance-curvature profile (the matte-hatched area) in the section S5 to the seventh section S7 may be made equal.

The boundary point between the fourth section S4 and the fifth section S5 is the point where the turning curvature ρc becomes zero (that is, the steering angle is zero) and the steering wheel returns to the neutral position. Hereinafter, the point at the boundary between the fourth section S4 and the fifth section S5 will be referred to as a "switching point." Further, the distance d2 from when the host vehicle 1 starts to the switching point (that is, the sum of the section lengths of the third section S3 and the fourth section S4) is expressed as the "switching point distance."

The distance-curvature profile generation unit 34 may switch and dynamically change the point distance d2 according to the surrounding environment of the own vehicle 1. For example, the distance-curvature profile generation unit 34 may obtain information about the environment around the host vehicle 1 from the detection results by the object sensor 11 or map information from the map database 14.
Please refer to FIGS. 7A and 7B. The distance-curvature profile generation unit 34 may set the switching point distance d2 according to the lane width W of the lane 102 in which the own vehicle 1 runs.

For example, the solid line 50 is a distance-curvature profile when the lane width W of the lane 102 is relatively wide, and the dashed-dotted line 51 is a distance-curvature profile when the lane width W of the lane 102 is relatively narrow.
The distance-curvature profile generation unit 34 generates a distance-curvature profile such that the switching point distance d2a when the lane width W is relatively wide is longer than the switching point distance d2b when the lane width W is relatively narrow. may be generated.

For example, the distance-curvature profile generation unit 34 may calculate the switching point distance d2 using the following (Equation 2).
d2=(W×Rmin) (Formula 2)
However, Rmin is the minimum turning radius of the own vehicle 1.

For example, if an obstacle (for example, a wall or a tree) exists in front of the route after passing the parked vehicle 100 (for example, the adjacent lane 103), the distance-curvature profile generation unit 34 determines that the obstacle does not exist. The distance-curvature profile may be generated so that the switching point distance d2 is shorter than in the case where the switching point distance d2 is shortened.

Refer to FIG. A solid line 50 is a distance-curvature profile when the lane 102 in which the host vehicle 1 travels is a straight road.
When the lane 102 on which the host vehicle 1 travels is a curved road, the distance-curvature profile generation unit 34 generates the turning curvature determined by the distance-curvature profile 50 and the road curvature of the lane 102 when the lane 102 is a straight road. The sum may be output as the target turning curvature ρt. For example, the distance-curvature profile generation unit 34 may obtain road curvature information from map information in the map database 14.
A dashed-dotted line 51 indicates a distance-curvature profile when the lane 102 is a right-curving road with a curvature ρR, and a dash-double-dotted line 52 indicates a distance-curvature profile when the lane 102 is a left-curved road with a curvature ρL. .

FIG. 9 shows the attitude angle of the host vehicle 1 at the switching point where the turning curvature ρc becomes zero. Further, a satin-hatched area 60 indicates the detection angle range of the object sensor 11.
The distance-curvature profile generation unit 34 may determine the attitude angle of the host vehicle 1 at the switching point according to the detection angle range 60 so that a specific direction falls within the detection angle range 60.
For example, the attitude angle of the host vehicle 1 may be determined so that the adjacent lane 103 falls within the detection angle range 60. This allows the object sensor 11 to detect a following vehicle traveling in the adjacent lane 103 and approaching the host vehicle 1 .

See FIG. 10. The distance-curvature profile generation unit 34 may change the rate of change of the turning curvature ρc with respect to the traveling distance in the fourth section S4, the fifth section S5, and the seventh section S7 as appropriate.
For example, when the lane change section distance DL is shorter, the rate of change in the turning curvature ρc may be made larger so that the steering angle can be changed more steeply. A solid line 50 is a distance-curvature profile when the lane change section distance DL is relatively long, and a dashed-dotted line 51 is a distance-curvature profile when the lane change section distance DL is relatively short.

When changing the rate of change of the turning curvature ρc in the fourth section S4, the fifth section S5, and the seventh section S7, the distance-curvature profile generation unit 34 determines whether the lane change to the adjacent lane 103 is completed within the lane change section. , and the first target curvature ρmax in the first section S1 and the third section S3 and the second target curvature ρ6 in the sixth section S6 are set so that the amount of change in the attitude angle of the host vehicle 1 is minimized.

As a result, when the lane change section distance DL is shorter, the absolute value of the first target curvature ρmax in the first section S1 and the third section S3 and the absolute value of the second target curvature ρ6 in the sixth section S6 are larger. Become.
In the example of FIG. 10, the first target curvature ρmax2 when the lane change section distance DL is relatively short is greater than the absolute value of the first target curvature ρmax1 and the second target curvature ρ61 when the lane change section distance DL is relatively long. and the absolute value of the second target curvature ρ62 becomes larger.

(motion)
Next, with reference to FIG. 11, an example of the vehicle driving support method according to the embodiment will be described.
In step S1, the avoidance support determination unit 30 determines whether the host vehicle 1 has stopped. When it is determined that the host vehicle 1 has stopped, the avoidance support determination unit 30 determines whether the lane change section distance DL, which is the distance to the stationary object in front of the host vehicle 1, is equal to or greater than the threshold value Dt2.

If the lane change section distance DL is not equal to or greater than the threshold value Dt2 (step S1: N), the parked vehicle 100 cannot be completely avoided, so the avoidance support determination unit 30 determines not to perform the avoidance support control. The driving support device 10 stops automatic driving control of the vehicle 1 and notifies the driver to continue driving the vehicle 1 manually. The process then ends.
If the lane change section distance DL is equal to or greater than the threshold value Dt2 (step S1: Y), the process proceeds to step S2.

In step S2, the avoidance support determination unit 30 determines whether the lane change section distance DL is less than the threshold value Dt1. If the lane change section distance DL is not less than the threshold value Dt1 (step S2: N), the avoidance support determination unit 30 determines not to perform avoidance support control, and the process proceeds to step S3.
In step S3, the driving support device 10 performs steering control to avoid the parked vehicle 100 by controlling the forward gaze point. The process then ends.

If the lane change section distance DL is less than the threshold Dt1 in the determination in step S2 (step S2: Y), the process proceeds to step S4.
In step S4, the time-curvature profile generation unit 33 generates a time-curvature profile.
In step S5, the steering angle control unit 36 controls the steering angle of the steered wheels according to the target turning curvature ρt output from the time-curvature profile generation unit 33 while the host vehicle 1 is stopped. In other words, stationary steering of the avoidance support control is executed.

In step S6, the avoidance support determination unit 30 determines whether stationary steering has been completed. That is, it is determined whether the turning curvature ρc of the host vehicle 1 has reached the first target curvature ρmax. If the stationary steering is not completed (step S6: N), the process returns to step S5. When the stationary steering is completed (step S6: Y), the process proceeds to step S7.

In step S7, the avoidance support determination unit 30 determines whether or not the own vehicle 1 can be started. If the host vehicle 1 cannot be started (step S7: N), the process returns to step S7. If the host vehicle 1 can be started (step S7: Y), the process advances to step S8.
In step S8, the distance-curvature profile generation unit 34 generates a distance-curvature profile.

In step S9, the steering angle control unit 36 controls the steering angle of the steered wheels according to the target turning curvature ρt output from the distance-curvature profile generation unit 34. Further, the vehicle speed control unit 38 controls the vehicle speed of the host vehicle 1 based on the vehicle speed set by the vehicle speed setting unit 37, and causes the host vehicle 1 to travel. This causes the vehicle 1 to change lanes so as to avoid the stationary object in front of the vehicle 1. The process then ends.

(Effects of embodiment)
(1) The avoidance support determination unit 30 determines whether the host vehicle 1 has stopped in front of a stationary object in front of the host vehicle 1. When it is determined that the own vehicle 1 has stopped in front of a stationary object, the time-curvature profile generation section 33, the control selection section 35, and the steering angle control section 36 perform the following operations while the own vehicle 1 is stopped. , according to the time-steering amount (curvature) profile, the steering wheel is rotated in a direction to avoid a stationary object until the steering amount (turning curvature) reaches a predetermined first target turning amount (first target curvature ρmax). steer.

After the steering amount (turning curvature) reaches the first steering amount (first target curvature ρmax), the distance-curvature profile generation unit 34, the control selection unit 35, the steering angle control unit 36, and the vehicle speed control The unit 38 starts the own vehicle 1 forward and runs the own vehicle 1 while turning the steering wheel according to the distance-steering amount (curvature) profile, thereby causing the own vehicle 1 to overtake a stationary object. Control.
Therefore, even when avoiding a stationary object in front of the host vehicle with a large steering angle, it is possible to prevent the vehicle behavior stability from decreasing. Thereby, route followability can be improved without reducing vehicle behavior stability.

(2) The time-steering amount (curvature) profile may include a first section S1 and a second section S2 following the first section S1. In the first section S1, the steering amount (turning curvature) changes at a constant rate of change. In the second section, the turning amount (turning curvature) is a constant first target turning amount (first target curvature ρmax).
By steering the steering wheels based on such a time-steering amount (curvature) profile, it is possible to perform stationary steering at a desired steering speed.

(3) The time-curvature profile generation unit 33 generates a first target turning amount (first target curvature ρmax) may be set.
This allows for steeper steering when the distance to a stationary object is short.

(4) The distance-steering amount (curvature) profile is the third section S3, the fourth section S4 following the third section S3, the fifth section S5 following the fourth section S4, and the fifth section S5 following the fifth section S5. It may include a sixth section S6 and a seventh section S7 following the sixth section S6. In the third section S3, the steering amount (turning curvature) is a constant first target steering amount (first target curvature ρmax). In the fourth section S4, the steering amount (turning curvature) changes at a constant rate of change from the first target steering amount (first target curvature ρmax) to zero. In the fifth section S5, the steering amount (turning curvature) changes at a constant rate of change until the second target steering amount (second target curvature ρ6) is opposite to the first target steering amount (first target curvature ρmax). Change. In the sixth section S6, the steering amount (turning curvature) is a constant second target steering amount (second target curvature ρ6). In the seventh section S7, the steering amount (turning curvature) changes from the second target steering amount (second target curvature ρ6) to zero at a constant rate of change.
By steering the steering wheel while running the host vehicle 1 based on such a distance-steering amount (curvature) profile, the stationary steering is achieved up to the first target turning amount (first target curvature ρmax). You can then change lanes to avoid stationary objects in front of you.

(5) The shorter the distance between the own vehicle 1 and the stationary object at the time of stopping in front of the stationary object, the more the steering amount (turning curvature) in the fourth section S4, the fifth section S5, or the seventh section S7 The rate of change may be set to a large value.
This allows for steeper steering when the distance to a stationary object is short.

(6) The sum of the areas of the distance-steering amount (curvature) profiles in the third section S3 and the fourth section S4, and the distance-steering amount (curvature) profile in the fifth section S5, sixth section S6, and seventh section S7. ) may be equal to the total area of the profile.
This allows the attitude angle before the lane change to be equal to the attitude angle after the lane change.

(7) The switching point distance, which is the sum of the length of the third section S3 and the length of the fourth section S4, may be dynamically determined according to the lane width W.
This allows the vehicle to change lanes according to the lane width W.

(8) If there is an obstacle in front of the path after passing a stationary object, the length of the third section S3 is the sum of the length of the fourth section S4, compared to the case where there is no obstacle. You can shorten the point distance by switching.
This makes it possible to dynamically change the switching point and drive with enough leeway to avoid approaching obstacles.

(9) The attitude angle of the host vehicle 1 at the starting point of the fifth section S5 may be determined according to the detection angle range of the object detection sensor mounted on the host vehicle 1.
This allows you to check that it is safe behind you before entering the adjacent lane.

(10) Target steering of the own vehicle 1 based on the sum of the turning curvature corresponding to the steering amount determined according to the distance-steering amount (curvature) profile and the road curvature of the road on which the own vehicle 1 is traveling. You may also calculate the angle.
This makes it possible to change lanes according to the road shape.

(11) If a following vehicle approaches from behind in the path after overtaking a stationary object, compared to a case where the following vehicle does not approach, the own vehicle will move according to the distance-turning amount (curvature) profile. The vehicle speed at which the vehicle runs may be set high.
This allows you to change lanes if a vehicle is approaching from behind so that the vehicle behind you does not have to wait.

DESCRIPTION OF SYMBOLS 1... Own vehicle, 10... Driving support device, 11... Object sensor, 12... Vehicle sensor, 13... Positioning device, 14... Map database, 15... Navigation device, 16... Communication device, 17... Controller, 18... Actuator, 21 ...Processor, 22...Storage device, 30...Escape support determination section, 31...Distance determination section, 32...Forward gaze point control section, 33...Time-steering amount (curvature) profile generation section, 34...Distance-steering Amount (curvature) profile generation section, 35... Control selection section, 36... Steering angle control section, 37... Vehicle speed setting section, 38... Vehicle speed control section

Claims (12)

A process of determining whether the host vehicle has stopped in front of a stationary object in front of the host vehicle;
When it is determined that the own vehicle has stopped in front of the stationary object, the rotation of the own vehicle with respect to the elapsed time during which the steering wheel of the own vehicle is turned while the own vehicle is stopped. a process of steering a steered wheel in a direction to avoid the stationary object until the steering amount reaches a first target steering amount according to a first profile that determines a steering amount;
After the amount of steering reaches the first target amount of steering, the vehicle is started forward, and the vehicle is started while steering the steering wheel according to a second profile that determines the amount of steering relative to the travel distance. A process of controlling the host vehicle to overtake the stationary object by driving the vehicle;
A driving support method characterized by causing a controller to execute the following. The first profile includes a first section and a second section following the first section,
In the first section, the steering amount changes at a constant rate of change,
In the second section, the steering amount is the constant first target steering amount,
The driving support method according to claim 1, characterized in that: According to claim 1 or 2, the first target steering amount is set to be larger as the distance between the host vehicle and the stationary object is shorter when the vehicle stops in front of the stationary object. Driving support method described. The second profile includes a third section, a fourth section following the third section, a fifth section following the fourth section, a sixth section following the fifth section, and a sixth section following the sixth section. a seventh section;
In the third section, the steering amount is the constant first target steering amount,
In the fourth section, the steering amount changes from the first target steering amount to zero at a constant rate of change,
In the fifth section, the steering amount changes at a constant rate of change up to a second target steering amount in the opposite direction to the first target steering amount,
In the sixth section, the steering amount is a constant second target steering amount,
In the seventh section, the steering amount changes at a constant rate of change from the second target steering amount to zero.
The driving support method according to any one of claims 1 to 3, characterized in that: The shorter the distance between the own vehicle and the stationary object at the time of stopping in front of the stationary object, the greater the rate of change in the steering amount in the fourth section, the fifth section, or the seventh section. 5. The driving support method according to claim 4, further comprising: setting. The total area of the second profile in the third section and the fourth section is equal to the total area of the second profile in the fifth section, the sixth section, and the seventh section. The driving support method according to claim 4 or 5. According to any one of claims 4 to 6, the switching point distance, which is the sum of the length of the third section and the length of the fourth section, is dynamically determined according to the lane width. Driving support method. When an obstacle exists in front of the path after overtaking the stationary object, the switch is the sum of the length of the third section and the length of the fourth section, compared to a case where the obstacle does not exist. The driving support method according to any one of claims 4 to 6, characterized in that the driving point distance is shortened. 9. The attitude angle of the host vehicle at the starting point of the fifth section is determined according to the detection angle range of an object detection sensor mounted on the host vehicle. Driving support method described. The target steering angle of the host vehicle is calculated based on the sum of the turning curvature corresponding to the steering amount determined according to the second profile and the road curvature of the road on which the host vehicle travels. The driving support method according to any one of claims 1 to 9. If a following vehicle is approaching from the rear of the path after overtaking the stationary object, the vehicle speed at which the host vehicle is driven according to the second profile is set higher than when the following vehicle is not approaching. The driving support method according to any one of claims 1 to 10, characterized in that: setting. A sensor that detects objects around the vehicle;
A process of determining whether the host vehicle has stopped in front of a stationary object detected in front of the host vehicle by the sensor, and when it is determined that the host vehicle has stopped in front of the stationary object, When the host vehicle is stopped, the host vehicle is steered in a direction to avoid the stationary object according to a first profile that determines the amount of steering of the host vehicle with respect to the elapsed time during which the steering wheel of the host vehicle is turned. A process of steering the steering wheel until the steering amount reaches a predetermined first target steering amount, and starting the own vehicle forward after the steering amount reaches the first target steering amount. , controlling the host vehicle to overtake the stationary object by driving the host vehicle while steering the steering wheel according to a second profile that determines the steering amount relative to the travel distance; controller and
A driving support device comprising:

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