JP2024063443A - Vehicle control method and vehicle control device - Google Patents

Abstract

[Problem] When the vehicle state of the vehicle deviates from the target driving trajectory, the target high speed is prevented from exceeding the actual driving trajectory of the vehicle. [Solution] In the vehicle control method, a speed profile is set as a target speed according to the position along the target driving trajectory (S2), the vehicle's current position and current attitude angle are detected (S3), and driving control is performed so that the vehicle's driving speed becomes a speed according to the speed profile based on the vehicle's position and the speed profile (S4). Furthermore, a predicted trajectory is predicted as the driving trajectory from the vehicle's current position to a first predetermined distance ahead based on the vehicle's position, attitude angle, and speed profile (S5), and deceleration control is performed to decelerate the vehicle when the maximum value of the distance in the lane width direction between the predicted trajectory and the target driving trajectory is equal to or greater than a predetermined threshold distance (S6 to S8). [Selected Figure] Fig. 7

Description

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

Patent document 1 describes a following driving control that appropriately applies a yaw moment to the vehicle through steering control and wheel braking/driving force distribution control, causing the vehicle to follow a target course.

JP 2018-167733 A

However, if the target driving speed is set according to the target driving trajectory, if the actual vehicle state deviates from the vehicle state assumed in the calculation of the target driving trajectory, the target driving speed may exceed the actual driving trajectory of the vehicle.
The present invention has an object to prevent a target traveling speed from exceeding an actual traveling trajectory of the host vehicle when a deviation occurs in the vehicle state of the host vehicle with respect to the target traveling trajectory.

According to one aspect of the present invention, a vehicle control method is provided that calculates a target driving trajectory of the host vehicle in a lane ahead of the host vehicle, sets a speed profile that is a target speed according to a position along the target driving trajectory, detects the host vehicle's current position and current attitude angle, and performs driving control so that the host vehicle's driving speed becomes a speed according to the speed profile based on the host vehicle's current position and the speed profile. In the vehicle control method, a predicted trajectory that is the driving trajectory from the host vehicle's current position to a first predetermined distance ahead is predicted based on the host vehicle's current position, attitude angle, and speed profile, and performs deceleration control to decelerate the host vehicle when the maximum value of the distance in the lane width direction between the predicted trajectory and the target driving trajectory is equal to or greater than a predetermined threshold distance.

According to the present invention, when the vehicle state of the vehicle deviates from the target driving trajectory, it is possible to prevent the target high speed from exceeding the actual driving trajectory of the vehicle.

1 is a schematic configuration diagram of an example of a vehicle control device according to an embodiment; FIG. 2 is a block diagram showing an example of a functional configuration of a controller according to the first to third embodiments. FIG. 2 is a schematic diagram of a road ahead of the host vehicle. FIG. 2 is a block diagram illustrating an example of a functional configuration of a driving planner. 10 is a block diagram illustrating an example of a functional configuration of a deviation amount prediction unit. FIG. FIG. 2 is a block diagram illustrating an example of a functional configuration of a speed planning unit. 4 is a flowchart of an example of a vehicle control method according to the first embodiment. 5A and 5B are schematic diagrams showing an example of setting a target position. 13 is a flowchart illustrating an example of a process of a speed plan correction unit according to the third embodiment. 13 is a flowchart illustrating an example of a speed profile correction determination process. 13 is a flowchart illustrating an example of a speed profile correction amount calculation process. 13 is a flowchart of an example of a correction amount calculation process. FIG. 13 is a block diagram illustrating an example of a functional configuration of a controller according to a fourth embodiment.

Below, an embodiment of the present invention will be described with reference to the drawings. Note that each drawing is a schematic view and may differ from the actual product. Furthermore, the embodiment of the present invention shown below is an example of an apparatus and method for embodying the technical concept of the present invention, and the technical concept of the present invention does not limit the structure, arrangement, etc. of the components to those described below. The technical concept of the present invention can be modified in various ways within the technical scope defined by the claims.

First Embodiment
(composition)
1 is a schematic diagram of an example of a vehicle control device according to an embodiment. The vehicle control device 10 is mounted on a host vehicle 1 and controls the running of the host vehicle 1.
The vehicle control device 10 includes an object sensor 11, a vehicle sensor 12, a positioning device 13, a map database 14, a controller 17, a driving force source controller 18a, a brake controller 18b, a steering controller 18c, a driving force source 19a, a brake actuator 19b, and a steering actuator 19c. In the drawings, the map database is referred to as a "map DB."

The object sensor 11 detects various information (ambient environment information) about the surrounding environment around the host vehicle 1. The object sensor 11 includes a plurality of different types of object detection sensors that detect objects around the host 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), which are mounted on the host vehicle 1.
The vehicle sensor 12 is mounted on the host vehicle 1 and detects various information (vehicle information) obtained from the host vehicle 1. The vehicle sensor 12 includes, for example, a vehicle speed sensor that detects the vehicle speed of the host vehicle 1, a wheel speed sensor that detects the rotational speed of the tires of the host vehicle 1, a three-axis acceleration sensor that detects the acceleration and deceleration in three axial directions of the host vehicle 1, a steering angle sensor that detects the steering angle of the steering wheel, a turning angle sensor that detects the turning angle of the steered wheels (turnable wheels), a gyro sensor that detects the angular velocity of the host vehicle 1, a yaw rate sensor that detects the yaw rate, an accelerator sensor that detects the accelerator opening degree of the host vehicle, and a brake sensor that detects the amount of brake operation.

The positioning device 13 includes a Global Navigation System (GNSS) receiver and receives radio waves from multiple navigation satellites to measure the current position and attitude angle of the vehicle 1. In the following description, the current position of the vehicle 1 may be referred to as the "self-position". The GNSS receiver may be, for example, a Global Positioning System (GPS) receiver. The positioning device 13 may be, for example, an inertial navigation system.
The map database 14 stores road map data. For example, the map database 14 may store high-precision map data (hereinafter simply referred to as "high-precision map") suitable as map information for automated driving. The map database 14 may also store map data for navigation (hereinafter simply referred to as "navigation map").

The controller 17 is an electronic control unit (ECU) that controls the host vehicle 1 .
For example, the vehicle control by the controller 17 may be autonomous driving control that causes the vehicle 1 to autonomously drive to a set destination based on surrounding environment information from the object sensor 11, vehicle information from the vehicle sensor 12, the current position measured by the positioning device 13, and road map data.
Furthermore, for example, the vehicle control by the vehicle control device 10 may be driving assistance control that assists the driver in driving the vehicle 1 by controlling the acceleration, deceleration, and steering of the vehicle 1 based on surrounding environment information, vehicle information, road map data, etc.

For example, driving assistance control may include lane keeping control, which controls the steering of the vehicle 1 so that the vehicle 1 does not deviate from the driving lane, preceding vehicle following control, which controls the acceleration and deceleration of the vehicle 1 so that the vehicle 1 follows the preceding vehicle, constant speed driving control, and following distance control.
The controller 17 includes a processor 17a and peripheral components such as a storage device 17b. The processor 17a may be, for example, a CPU or an MPU. The storage device 17b may include a semiconductor storage device, a magnetic storage device, an optical storage device, or the like.

The storage device 17b may include memories such as a register, a cache memory, a ROM used as a main storage device, and a RAM, etc. The functions of the controller 17 described below are realized, for example, by the processor 17a executing a computer program stored in the storage device 17b.
The controller 17 may be formed of dedicated hardware for executing each information processing 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 PLD such as an FPGA.

The driving force source controller 18a is an ECU that controls the driving force source 19a so that the driving force source 19a operates in accordance with a driving torque command value output from the controller 17. The driving force source 19a may include, for example, one or both of a driving motor and an internal combustion engine (engine).
The brake controller 18 b is an ECU that controls a brake actuator (hydraulic actuator) 19 b that actuates a braking device (brake device) for the front and rear wheels so as to operate in accordance with a brake fluid pressure command value output from the controller 17 .
The steering controller 18 c is an ECU that controls a steering actuator 19 c that steers the steered wheels so as to operate in accordance with a steering torque command value output from the controller 17 .

2 is a block diagram showing an example of the functional configuration of the controller 17 according to the first embodiment. The controller 17 includes a lane boundary generating unit 30, a driving plan unit 31, a speed control unit 32, a trajectory tracking control unit 33, a deviation amount predicting unit 34, a speed plan correcting unit 36, a braking/driving force calculating unit 37, and a steering torque calculating unit 38.
The lane boundary generation unit 30 generates a lane, which is the area ahead in which the vehicle 1 can travel along the lane, based on information about the lane markings (white lines) of the lane in which the vehicle 1 is traveling detected by the object sensor 11 and the high-precision map in the map database 14.

Fig. 3 is a schematic diagram of a road ahead of the vehicle 1. The positive direction of the X-axis is defined as the traveling direction of the vehicle 1, and the positive direction of the Y-axis is defined as the direction perpendicular to the X-axis and to the left of the vehicle 1. The same is true for Fig. 8(a) and Fig. 8(b).
The lane boundary generating unit 30 generates a boundary BR on the right side of the lane (hereinafter sometimes referred to as the "right lane boundary BR") and a boundary BL on the left side of the lane (hereinafter sometimes referred to as the "left lane boundary BL"). The right lane boundary BR and the left lane boundary BL may be collectively referred to as the "lane boundaries BR and BL".

For example, the lane boundary generating unit 30 may generate a sequence of points P _R0 , P _R1 , P _R2 ... P _R8 forming a boundary line as the right lane boundary BR, and generate a sequence of points P _L0 , P _L1 , P _L2 ... P _L8 forming a boundary line as the left lane boundary BL. In the following description, the individual points P _R0 , P _R1 , P _R2 ... P _R8 , P _L0 , P _L1 , P _L2 ... P _L8 included in these sequence of points may be referred to as "boundary points." Note that the number of the sequence of points of these lane boundaries BR and BL is not limited to nine, and may be eight or less, or ten or more.

2. The driving plan unit 31 calculates a target driving trajectory, which is a target future driving trajectory, based on the vehicle's own position measured by the positioning device 13 and the lane boundaries BR and BL generated by the lane boundary generation unit 30. In addition, based on the calculated target driving trajectory and the deceleration request flag F and the correction speed Vp output from the speed plan correction unit 36, a speed profile, which is a target speed according to the position along the target driving trajectory, is set.
4 is a block diagram of an example of a functional configuration of the driving planner 31. The driving planner 31 includes a trajectory planner 40 and a speed planner 41.

The trajectory planning unit 40 calculates the target driving trajectory Tt based on the vehicle's own position and the lane boundaries BR and BL. For example, the trajectory planning unit 40 may calculate a trajectory that passes between the lane boundaries BR and BL as the target driving trajectory Tt.
Refer to Fig. 3. For example, the trajectory planning unit 40 may generate a sequence of points _Pt1 , _Pt2 ... _Pt8 forming a trajectory as the target running trajectory Tt. For example, the midpoint between the boundary points P _R1 and P _L1 , the midpoint between the boundary points P _R2 and P _L2 , ... the midpoint between the boundary points P _R8 and P _L8 may be calculated as points _Pt1 , _Pt2 ... _Pt8 on the target running trajectory Tt, respectively. Note that the number of the sequence of points of the target running trajectory Tt is not limited to eight, and may be seven or less, or nine or more.
4, the speed planning unit 41 sets a speed profile based on the target travel trajectory Tt, a deceleration request flag F and a correction speed Vp, which will be described later. The speed planning unit 41 will be described in detail later.

Refer to Fig. 2. The speed control unit 32 calculates driving/braking force commands for controlling the traveling speed of the host vehicle 1 to a speed according to the speed profile set by the traveling plan unit 31 and the host vehicle's own position, and outputs the commands to a driving/braking force calculation unit 37.
The trajectory tracking control unit 33 generates a turning command for traveling along the target traveling trajectory Tt calculated by the traveling plan unit 31. The turning command may be, for example, a target lateral force command to be generated in the host vehicle 1, a target steering torque command for steering the steered wheels, or a target steering angle command for the steered wheels.

The trajectory tracking control unit 33 generates turning commands at a plurality of times within a predetermined time range from the current time to the future. For example, the trajectory tracking control unit 33 may generate turning commands at each time from the current time to the future by optimizing calculation of model predictive control so that the difference between the traveling trajectory of the host vehicle 1 and the target traveling trajectory Tt is minimized.
In the following description, it is assumed that the turning command is a target lateral force command _Fyi , where the subscript i=0, 1, 2, 3, ... indicates each time, _Fy0 is the target lateral force command at the current time, and _Fy1 , _Fy2 , _Fy3 , ... are target lateral force commands at each future time.
The trajectory tracking control unit 33 outputs a turning command Fy ₀ at the current time to the steering torque calculation unit 38 , and outputs turning commands Fy ₀ , Fy ₁ , Fy ₂ , Fy ₃ . . . for each time from the current time to the future to the deviation amount prediction unit 34 .

The deviation prediction unit 34 predicts a predicted trajectory, which is the driving trajectory from the current position of the vehicle 1 to a predetermined distance ahead, and predicts the deviation (deviation) in the lane width direction between the predicted trajectory and the target driving trajectory Tt.
5 is a block diagram showing an example of the functional configuration of the deviation amount prediction unit 34. The deviation amount prediction unit 34 includes a predicted trajectory generation unit 50 and a deviation amount calculation unit 51.
The predicted trajectory generating unit 50 generates a predicted trajectory based on the current vehicle speed of the vehicle 1 detected by the vehicle speed sensor of the vehicle sensor 12, the current self-position and attitude angle of the vehicle 1 measured by the positioning device 13, the turning command _Fyi , and the speed profile.

See Fig. 3. For example, the predicted trajectory generating unit 50 may generate a sequence of points _P1 , _P2 ... _P8 forming a trajectory as a predicted trajectory Tp. In the following description, each point included in the sequence of points _P1 , _P2 ... _P8 may be referred to as a "predicted point." Note that the number of points in the predicted trajectory Tp is not limited to eight, and may be seven or less, or nine or more.

For example, the predicted trajectory generating unit 50 may set the vehicle speed V _i at each time from the present to the future based on the vehicle speed at the current time detected by the vehicle speed sensor of the vehicle sensor 12 and the speed profile, and calculate the yaw rate dθ _i /dt at each time by dθ _i /dt = Fy _i /mV _i , where m is the mass of the host vehicle 1.

Then, the attitude angle _θi at each future time is calculated by integrating the yaw rate _dθi /dt with the current attitude angle θ measured by the positioning device 13 as an initial value, and the amount of change _dYi /dt = _Vi × _θi of the Y coordinate of the vehicle 1 at each future time is calculated.Then, the amount of change _dYi /dt is integrated with the Y coordinate of the current self-position as an initial value, to calculate the Y coordinate _Yi of the vehicle 1 at each future time.The X coordinate _Xi of the vehicle 1 at each future time is also calculated in a similar manner.

5. The deviation amount calculation unit 51 predicts a deviation amount ΔY in the lane width direction between the predicted trajectory Tp and the target driving trajectory Tt. For example, the deviation amount calculation unit 51 may calculate the maximum value of the distance in the lane width direction between the predicted trajectory Tp and the target driving trajectory Tt as the deviation amount ΔY. For example, if the deviation amounts in the lane width direction between each of the predicted points P ₁ , P ₂ ... P ₈ and the target driving trajectory Tt are d ₁ , d ₂ ... d ₈ respectively, the maximum value max (d ₁ , d ₂ ... d ₈ ) may be calculated as the deviation amount ΔY.

2. The deviation prediction unit 34 outputs the calculated deviation ΔY to the speed plan correction unit 36. The speed plan correction unit 36 determines whether the absolute value of the deviation |ΔY| is equal to or greater than a predetermined threshold distance _ΔYth . For example, the threshold distance _ΔYth may be the distance from the target travel trajectory Tt to the lane boundaries BL and BR.
When the absolute value |ΔY| is equal to or greater than the threshold distance _ΔYth , the speed plan correction unit 36 sets the value of the deceleration request flag F to "1." When the absolute value |ΔY| is not equal to or greater than the threshold distance _ΔYth , the speed plan correction unit 36 sets the value of the deceleration request flag F to "0."

Furthermore, when the absolute value of the deviation amount |ΔY| is equal to or greater than the threshold distance _ΔYth , the speed plan correction unit 36 sets a speed lower than that of the speed profile as the corrected speed Vp. For example, the speed plan correction unit 36 may increase the reduction amount of the corrected speed Vp compared to the speed profile as the absolute value |ΔY| increases. The speed plan correction unit 36 outputs the deceleration request flag F and the corrected speed Vp to the travel plan unit 31.

6 is a block diagram of an example of the functional configuration of the speed planning unit 41 of the travel planning unit 31. The speed planning unit 41 calculates a target curvature ρ _i , which is a curvature at each point P _ti (i=1, 2, ...) on the target travel trajectory Tt, and sets a lateral acceleration ay _i that is permissible for the vehicle 1 at each point P _ti . The speed planning unit 41 may set, for example, a permissible maximum value of the turning acceleration as the lateral acceleration ay _i . In the following description, the lateral acceleration ay _i is expressed as a "set lateral acceleration ay _i ". The speed planning unit 41 calculates a target speed for traveling on a trajectory of the target curvature ρ _i according to the set lateral acceleration ay _i at each point P _ti as a speed profile.

The speed planning unit 41 includes a curvature calculation unit 60, a target speed calculation unit 61, and a selection unit 62. The curvature calculation unit 60 calculates a target curvature ρ _i . The target speed calculation unit 61 calculates a target speed V _i for traveling a trajectory of a target curvature ρ _i at a set lateral acceleration ay _i at each point P _ti . For example, the target speed calculation unit 61 may calculate the target speed V _i by the following equation (1).
V _i = ay _i / ρ _i ... (1)
When calculating the target speed _Vi , the target speed calculation unit 61 determines whether the value of the deceleration request flag F is "1" (that is, whether the absolute value of the deviation amount |ΔY| is equal to or greater than the threshold distance _ΔYth ).

When the value of the deceleration request flag F is "1", the target speed calculation unit 61 performs deceleration control to decelerate the host vehicle 1. For example, the target speed calculation unit 61 may decelerate the host vehicle 1 by lowering the target speed _Vi . As a result, the speed profile of the host vehicle 1 is corrected so that the host vehicle 1 decelerates.
Also, for example, the target speed calculation unit 61 may decrease the value of the set lateral acceleration ay _i . As a result, the target speed V _i of the speed profile itself becomes lower, and deceleration control is performed to decelerate the host vehicle 1.
Furthermore, the selection unit 62 selects the lower of the target speed V _i and the corrected speed V p at each point P _ti and outputs it as a speed profile. Therefore, when the corrected speed V p is lower than the target speed V _i , the speed lower than the target speed V _i is output as the speed profile, and deceleration control is performed to decelerate the host vehicle 1.

2, the braking/driving force calculation unit 37 generates a driving torque command value for causing the host vehicle 1 to generate a driving force in accordance with the braking/driving force command output by the speed control unit 32, and outputs the generated driving torque command value to the driving force source controller 18a. Also, the braking/driving force calculation unit 37 generates a braking fluid pressure command value for causing the brake device of the host vehicle 1 to generate a braking force in accordance with the braking/driving force command, and outputs the generated braking fluid pressure command value to the brake controller 18b.
The steering torque calculation unit 38 generates a steering torque command value for turning the steered wheels in accordance with the turning command output by the trajectory tracking control unit 33, and outputs the steering torque command value to the steering controller 18c.

FIG. 7 is a flowchart of an example of the vehicle control method according to the first embodiment.
In step S1, the driving plan unit 31 calculates a target driving trajectory Tt. In step S2, the driving plan unit 31 sets a speed profile. In step S3, the positioning device 13 calculates a current host position and attitude angle. In step S4, the speed control unit 32 controls the host vehicle's driving speed based on the host position and the speed profile so that the host vehicle's driving speed becomes a speed according to the speed profile.

In step S5, the deviation amount calculation unit 51 predicts a predicted trajectory Tp. In step S6, the deviation amount calculation unit 51 calculates a deviation amount ΔY in the lane width direction between the predicted trajectory Tp and the target driving trajectory Tt.
In step S7, the speed plan correction unit 36 judges whether the absolute value |ΔY| of the deviation is equal to or greater than a predetermined threshold distance _ΔYth . If the absolute value |ΔY| is equal to or greater than the threshold distance _ΔYth (step S7: Y), the process proceeds to step S8. If the absolute value |ΔY| is not equal to or greater than the threshold distance _ΔYth (step S7: N), the process ends.
In step S8, the speed planning unit 41 of the travel planning unit 31 performs deceleration control to decelerate the host vehicle. For example, the target speed calculation unit 61 may decelerate the host vehicle 1 by lowering the target speed Vi. As a result, the speed profile of the host vehicle 1 is corrected so that the host vehicle 1 decelerates. Also, for example, the target speed calculation unit 61 may decrease the value of the set lateral acceleration ayi. As a result, the target speed Vi of the speed profile itself becomes lower, and deceleration control is performed to decelerate the host vehicle 1. The process then ends.

Second Embodiment
In addition to the functions of the vehicle control device 10 of the first embodiment, the vehicle control device 10 of the second embodiment performs deceleration control of the host vehicle 1 at a greater deceleration as the deviation amount ΔY in the lane width direction between the predicted trajectory Tp and the target driving trajectory Tt increases when the absolute value |ΔY| of the deviation amount in the lane width direction between the predicted trajectory Tp and the target driving trajectory Tt is equal to or greater than a predetermined threshold distance ΔYth. The functional configuration of the controller 17 in the second embodiment is similar to that of the controller 17 of the first embodiment shown in FIG. 2, and the same or similar components are denoted by the same reference numerals.

Refer to FIG. 2. The speed plan correction unit 36 may set the correction speed Vp to be lower as the absolute value of the deviation amount |ΔY| is larger. The lower the correction speed Vp, the lower the speed profile is set, and therefore the deceleration required to decelerate from the current driving speed to the speed profile becomes larger.

For example, the speed plan correction unit 36 may set the turning curvature at which the host vehicle 1 can pass through a point closer to the target driving trajectory than the predicted trajectory Tp as the target turning curvature ρp, and set the speed at which the host vehicle 1 can turn at the target turning curvature ρp as the correction speed Vp. This causes the host vehicle 1 to decelerate to the correction speed Vp at which the host vehicle 1 can turn at the target turning curvature ρp. The speed plan correction unit 36 may set a larger value for the target turning curvature ρp as the absolute value of the deviation amount |ΔY| increases.

8A. When the absolute value of the deviation amount |ΔY| is equal to or greater than a predetermined threshold distance _ΔYth , the speed plan correction unit 36 sets a target position Pt by offsetting, for example, a predicted point _P8 on the predicted trajectory Tp toward the target driving trajectory Tt in the lane width direction by an offset amount Ofs. In the example of FIG. 8A, the target position Pt is set on the target driving trajectory Tt.
The speed plan correction unit 36 calculates a target turning curvature ρp for turning the host vehicle 1 so as to travel through the target position Pt.

For example, the x-coordinate and y-coordinate of the target position Pt in a coordinate system having the current position of the vehicle 1 as the coordinate origin are defined as xp and yp, respectively, the positive direction of the X-axis is defined as the traveling direction of the vehicle 1, and the positive direction of the Y-axis is defined as the direction perpendicular to the X-axis and to the left of the vehicle 1. In this case, the speed plan correction unit 36 may calculate the target turning curvature ρp by the following equation (2).
ρp=2×yp/( ^xp2 + ^yp2 ) ... (2)

The speed plan correction unit 36 may calculate the corrected speed Vp using the following equation (3), assuming that the maximum lateral force m×ρ× ^Vp2 that can be generated when turning a trajectory with target turning curvature ρp at the corrected speed Vp is equal to the maximum lateral force m×ρ× ^V2 that will be generated when traveling on the predicted trajectory Tp.
Vp = V × (ρp / ρ) ^1/2 ... (3)
In the above formula (2), the turning curvature ρ and the vehicle speed V may be those at any point on the predicted trajectory Tp. For example, the turning curvature and the vehicle speed at a point Pc where the predicted trajectory Tp intersects with a lane boundary (the left lane boundary BL in the example of FIG. 8A) may be used.

In the example of Fig. 8B, the target position Pt is set to a position between the predicted trajectory Tp and the target driving trajectory Tt according to the magnitude of the absolute value of the deviation |ΔY|. That is, the offset amount Ofs for offsetting the predicted point _P8 on the predicted trajectory Tp toward the target driving trajectory Tt in the lane width direction may be variable according to the magnitude of the absolute value of the deviation |ΔY|.
For example, the larger the absolute value of the deviation amount |ΔY|, the larger the offset amount Ofs may be to offset the predicted point _P8 toward the target traveling trajectory Tt to set the target position Pt. As a result, the larger the absolute value of the deviation amount |ΔY|, the larger the turning curvature becomes, and the lower the correction speed Vp becomes. As a result, the deceleration for decelerating from the current traveling speed to the speed profile becomes larger.

Third Embodiment
In addition to the functions of the vehicle control device 10 of the first and second embodiments, the vehicle control device 10 of the third embodiment determines whether or not a target driving trajectory Tt from the current position of the vehicle 1 to a predetermined distance ahead is a turning trajectory, and performs deceleration control to decelerate the vehicle 1 when the absolute value |ΔY| of the deviation amount in the lane width direction between the predicted trajectory Tp and the target driving trajectory Tt is equal to or greater than a predetermined threshold distance _ΔYth and the target driving trajectory Tt is a turning trajectory. The functional configuration of the controller 17 in the second embodiment is similar to that of the controller 17 of the first embodiment shown in FIG. 2, and the same or similar components are indicated by the same reference numerals.

With reference to Fig. 2, the speed plan correction unit 36 judges whether or not the target travel trajectory Tt from the current position of the vehicle 1 to a predetermined distance ahead is a turning trajectory.
For example, the sign of the turning curvature when turning to the left is defined as positive, and the sign of the turning curvature when turning to the right is defined as negative. The speed plan correction unit 36 may compare the turning curvature ρ _i of each point on the target traveling trajectory Tt with a predetermined turning determination threshold ρ _crcl .

The speed plan correction unit 36 may determine that the target travel trajectory Tt from the current position to a predetermined distance ahead is a right-turning trajectory when the turning curvature ρ _i is less than -ρ _crcl , and may determine that the target travel trajectory is a left-turning trajectory when the turning curvature ρ _i is greater than ρ _crcl . Also, when the turning curvature ρ _i is equal to or greater than -ρ _crcl and equal to or less than ρ _crcl , the speed plan correction unit 36 may determine that the target travel trajectory Tt from the current position to a predetermined distance ahead is not a turning trajectory.
The speed plan correction unit 36 may set a correction speed Vp lower than the speed profile when the absolute value of the deviation |ΔY| is equal to or greater than a predetermined threshold distance _ΔYth and the target traveling trajectory Tt is a turning trajectory.

Further, for example, when the target traveling trajectory Tt is a turning trajectory, the speed plan correction unit 36 may determine whether or not the predicted trajectory Tp is located outside the target traveling trajectory Tt in the turning direction.
For example, when the target traveling trajectory Tt is a turning trajectory that turns right, the speed plan correction unit 36 determines whether the predicted trajectory Tp is located to the left of the target traveling trajectory Tt. For example, when the deviation amount ΔY is equal to or greater than the threshold distance ΔY _th , the speed plan correction unit 36 determines that the predicted trajectory Tp is located to the left of the target traveling trajectory Tt in the turning direction.

On the other hand, when the target driving trajectory Tt is a turning trajectory that turns left, the speed plan correction unit 36 determines whether the predicted trajectory Tp is located to the right of the target driving trajectory Tt. For example, when the deviation amount ΔY is equal to or smaller than the threshold distance (−ΔY _th ), the speed plan correction unit 36 determines that the predicted trajectory Tp is located to the right of the target driving trajectory Tt in the turning direction.
The speed plan correction unit 36 may set a correction speed Vp lower than that of the speed profile when the absolute value of the deviation amount |ΔY| is equal to or greater than _a predetermined threshold distance ΔYth, the target traveling trajectory Tt is a turning trajectory, and the predicted trajectory Tp is located outside the target traveling trajectory Tt in the turning direction. For example, the speed plan correction unit 36 may set a correction speed Vp similar to that of the second embodiment.

On the other hand, when it is not determined that the predicted trajectory Tp is located outside the target traveling trajectory Tt in the turning direction, the speed plan correction unit 36 does not correct the target speed V _i calculated by the target speed calculation unit 61 of the speed plan unit 41 using the above formula (1). Therefore, the target speed V _i is set as it is as the speed profile.
For example, the speed plan correction unit 36 may set the corrected speed Vp to a value equal to or _greater than the target speed _Vi so that the selection unit 62 of the speed plan unit 41 selects the target speed Vi.

FIG. 9 is a flowchart of an example of a process of the speed plan correction unit 36 in the third embodiment.
In step S10, the speed plan correction unit 36 executes a speed profile correction determination process. The details of the speed profile correction determination process will be described later with reference to FIG.
In step S11, the speed plan correction unit 36 executes a speed profile correction amount calculation process. The details of the speed profile correction amount calculation process will be described later with reference to FIG.

FIG. 10 is a flowchart of an example of the speed profile correction determination process.
In step S20, the speed plan correction unit 36 determines whether the absolute value |ΔY| in the lane width direction between the predicted trajectory Tp and the target driving trajectory Tt is equal to or greater than a predetermined threshold distance _ΔYth . If the absolute value |ΔY| is equal to or greater than the threshold distance _ΔYth (step S20: Y), the process proceeds to step S21. If the absolute value |ΔY| is not equal to or greater than the threshold distance _ΔYth (step S20: N), the process proceeds to step S22.
In step S21, the speed plan correction unit 36 sets the value of the deceleration request flag F to "1." Then, the speed profile correction determination process ends.
In step S22, the speed plan correction unit 36 sets the value of the deceleration request flag F to "0." Thereafter, the speed profile correction determination process ends.

FIG. 11 is a flowchart of an example of the speed profile correction amount calculation process.
In step S30, the speed plan correction unit 36 judges whether the turning curvature ρ _i of each point on the target traveling trajectory Tt is less than the turning judgment threshold (-ρ _crcl ). If the turning curvature ρ _i is less than the turning judgment threshold (-ρ _crcl ) (step S30: Y), it is judged that the target traveling trajectory Tt is a turning trajectory that turns right, and the process proceeds to step S31. If the turning curvature ρ _i is not less than the turning judgment threshold (-ρ _crcl ) (step S30: N), the process proceeds to step S34.

In step S31, the speed plan correction unit 36 judges whether the deviation amount ΔY is equal to or greater than the threshold distance _ΔYth . If the deviation amount ΔY is equal to or greater than the threshold distance _ΔYth (step S31: Y), it is judged that the predicted trajectory Tp is located to the left of the target traveling trajectory Tt in the turning direction, and the process proceeds to step S32. If the deviation amount ΔY is not equal to or greater _than the threshold distance ΔYth (step S31: N), the process proceeds to step S33.
In step S32, the speed plan correction unit 36 executes a correction amount calculation process. The details of the correction amount calculation process will be described later with reference to Fig. 12. After that, the speed profile correction amount calculation process ends.

In step S34, the speed plan correction unit 36 judges whether the turning curvature ρ _i of the target driving trajectory Tt is greater than the turning judgment threshold ρ _crcl . If the turning curvature ρ _i of the target driving trajectory Tt is greater than the turning judgment threshold ρ _crcl (step S34: Y), it is judged that the target driving trajectory Tt is a turning trajectory that turns left, and the process proceeds to step S35. If the turning curvature ρ _i of the target driving trajectory Tt is not greater than the turning judgment threshold ρ _crcl (step S34: N), it is judged that the target driving trajectory Tt is not a turning trajectory, and the process proceeds to step S37.

In step S35, the speed plan correction unit 36 judges whether the deviation amount ΔY is equal to or less than the threshold distance (-ΔY _th ). If the deviation amount ΔY is equal to or less than the threshold distance (-ΔY _th ) (step S35: Y), it is judged that the predicted trajectory Tp is located to the right of the target traveling trajectory Tt in the turning direction, and the process proceeds to step S36. If the deviation amount ΔY is not equal to or less than the threshold distance (-ΔY _th ) (step S35: N), the process proceeds to step S37.
In step S36, the speed plan correction unit 36 executes a correction amount calculation process, after which the speed profile correction amount calculation process ends.
In steps S33 and S37, the speed plan correction unit 36 ends the process without correcting the target speed _Vi calculated by the target speed calculation unit 61 of the speed plan unit 41. In this case, the target speed Vi is set as it is as the speed profile.

FIG. 12 is a flowchart of an example of the correction amount calculation process.
In step S40, the speed plan correction unit 36 sets the target position Pt as described with reference to FIG. 8(a) or FIG. 8(b).
In step S41, the speed plan correction unit 36 calculates a target turning curvature ρp for turning the host vehicle 1 so as to travel through the target position Pt.
In step S42, the speed plan correction unit 36 calculates a speed at which the vehicle can turn with the target turning curvature ρp as a correction speed Vp. Then, the correction amount calculation process ends.

Fourth Embodiment
The vehicle control device 10 of the fourth embodiment, in addition to the functions of the vehicle control device 10 of the first to third embodiments, performs steering control to turn the steered wheels of the vehicle 1 or braking/driving force distribution control to apply a yaw moment to the vehicle 1 in accordance with the deviation amount ΔY in the lane width direction between the predicted trajectory Tp and the target driving trajectory Tt, thereby correcting the driving trajectory of the vehicle 1 by applying a lateral force in the opposite direction to the direction in which the predicted trajectory Tp deviates from the target driving trajectory Tt.

Fig. 13 is a block diagram of an example of the functional configuration of the controller 17 of the fourth embodiment. The functional configuration of the controller 17 of the second embodiment has the components of the functional configuration of the controller 17 of the first embodiment shown in Fig. 2, and the same or similar components are denoted by the same reference numerals.
The controller 17 of the fourth embodiment further includes a deviation avoidance control unit 35. The deviation amount prediction unit 34 outputs the calculated deviation amount ΔY to the deviation avoidance control unit 35 and the speed plan correction unit 36.

The departure avoidance control unit 35 calculates a turning command correction amount according to the deviation amount ΔY to apply a lateral force in the opposite direction to the deviation direction of the deviation amount ΔY by steering control that turns the steered wheels. The departure avoidance control unit 35 also calculates a braking/driving force command correction amount according to the deviation amount ΔY to apply a lateral force in the opposite direction to the deviation direction of the deviation amount ΔY by braking/driving force distribution control that applies a yaw moment to the host vehicle 1.

For example, the departure avoidance control unit 35 may calculate a turning command correction amount or a braking/driving force command correction amount when the absolute value of the deviation amount |ΔY| is equal to or greater than a predetermined threshold distance ΔYth. Also, for example, the departure avoidance control unit 35 may calculate a turning command correction amount or a braking/driving force command correction amount that applies a lateral force toward the inside of the turning direction when the absolute value of the deviation amount |ΔY| is equal to or greater than a predetermined threshold distance ΔYth and the predicted trajectory Tp is positioned outside the target driving trajectory Tt in the turning direction.

Departure avoidance control section 35 outputs a turning command correction amount to steering torque calculation section 38 , and outputs a braking/driving force command correction amount to braking/driving force calculation section 37 .
The driving/braking force calculation unit 37 corrects the driving/braking force command output by the speed control unit 32 with the driving/braking force command correction amount, generates a driving torque command value and a brake fluid pressure command value according to the corrected driving/braking force command, and outputs them to the driving force source controller 18a and the brake controller 18b, respectively.
The steering torque calculation unit 38 corrects the turning command output by the trajectory tracking control unit 33 with the turning command correction amount, generates a steering torque command value for turning the steered wheels in accordance with the corrected turning command, and outputs it to the steering controller 18c.

(Modification)
In the above first to fourth embodiments, when the absolute value |ΔY| of the deviation amount in the lane width direction between the predicted trajectory Tp and the target driving trajectory Tt is equal to or greater than a predetermined threshold distance _ΔYth , a deceleration control is performed to decelerate the host vehicle 1. Alternatively or additionally, in each of the above first to fourth embodiments, a separation distance in the lane width direction between the predicted trajectory Tp and the lane boundaries BR and BL may be calculated, and deceleration control may be performed to decelerate the host vehicle 1 when the separation distance is equal to or less than a predetermined threshold.

For example, the Y coordinates of predicted points _P1 , _P2 ... on the predicted trajectory Tp are respectively _Y1 , _Y2 ..., the Y coordinates of boundary points _PR0 , _PR1 , _PR2 ... on the right lane boundary BR are respectively _YR0 , _YR1 , _YR2 ..., and the Y coordinates of boundary points _PL0 , _PL1 , _PL2 ... on the left lane boundary BL are respectively _YL0 , _YL1 , _YL2 ....
When any of the distances ( _YLi - _Yi ) in the lane width direction between the predicted trajectory Tp and the left lane boundary BL is equal to or less than a predetermined threshold value Δy, the speed plan correction unit 36 sets the value of the deceleration request flag F to "1" and sets a speed lower than the speed profile as the corrected speed Vp (i=1, 2, ...). When any of the distances ( _Yi - _YRi ) in the lane width direction between the predicted trajectory Tp and the right lane boundary BR is equal to or less than a predetermined threshold value Δy (i=1, 2, ...), the speed plan correction unit 36 sets the value of the deceleration request flag F to "1" and sets a corrected speed Vp lower than the speed profile.

(Effects of the embodiment)
(1) According to an embodiment, a vehicle control method is provided that calculates a target driving trajectory of the host vehicle 1 in a lane ahead of the host vehicle 1, sets a speed profile which is a target speed according to a position along the target driving trajectory, detects a self-position which is a current position of the host vehicle 1 and a current attitude angle, and performs driving control so that the driving speed of the host vehicle 1 becomes a speed according to the speed profile based on the self-position and the speed profile. In the vehicle control method, a predicted trajectory which is a driving trajectory from the current position of the host vehicle 1 to a predetermined distance ahead is predicted based on the self-position, attitude angle, and speed profile, and performs deceleration control to decelerate the host vehicle 1 when the maximum value of the distance in the lane width direction between the predicted trajectory and the target driving trajectory is equal to or greater than a predetermined threshold distance.

As a result, even if a deviation occurs in the current vehicle state (e.g., position or attitude angle) of the vehicle 1 assumed in the target driving trajectory or speed profile, and the vehicle is unable to travel along the target driving trajectory in the future, the speed profile can be decelerated according to the position between the predicted trajectory and the road boundary, and the deviation of the predicted trajectory from the target trajectory. As a result, the target driving speed can be prevented from exceeding the driving trajectory that the vehicle is actually scheduled to travel.

(2) In addition to the above deceleration control, the driving trajectory of the vehicle 1 may be corrected by applying a lateral force in the opposite direction to the direction in which the predicted trajectory deviates from the target driving trajectory through steering control to turn the steered wheels of the vehicle 1 or braking/driving force distribution control to apply a yaw moment to the vehicle 1.
This makes it possible to suppress deviation from the target driving trajectory through steering control and braking/driving force distribution control.
(3) The predetermined threshold distance may be equal to the distance from the target driving trajectory to a lane boundary.
This makes it possible to prevent the vehicle from approaching the lane boundary too closely.

(4) In the vehicle control method of the embodiment, it is determined whether the target driving trajectory from the current position of the vehicle 1 to a predetermined distance ahead is a turning trajectory, and if the maximum value of the distance in the lane width direction between the predicted trajectory and the target driving trajectory is equal to or greater than a predetermined threshold distance and the target driving trajectory is a turning trajectory, the above-mentioned deceleration control may be performed.
This makes it possible to execute deceleration control when turning, which is when the vehicle is likely to approach a lane boundary.

(5) In the vehicle control method of the embodiment, it is determined whether the predicted trajectory is located outside the target driving trajectory in the turning direction, and the above-mentioned deceleration control may be performed only if the maximum value of the distance in the lane width direction between the predicted trajectory and the target driving trajectory is greater than or equal to a predetermined threshold distance, the target driving trajectory is a turning trajectory, and the predicted trajectory is located outside the target driving trajectory in the turning direction.
This makes it possible to execute deceleration control in a situation where the predicted trajectory is located outside the target driving trajectory in the turning direction and the vehicle is likely to approach the lane boundary.

(6) When the maximum value of the distance in the lane width direction between the predicted trajectory and the target driving trajectory is large, the deceleration control may be performed at a larger deceleration than when the maximum value is small.
This enables deceleration at an appropriate deceleration rate according to the amount of deviation between the predicted trajectory and the target driving trajectory.
(7) In the vehicle control method according to the embodiment, a target turning curvature may be set, and in the deceleration control, the host vehicle 1 may be decelerated to a speed at which the host vehicle 1 can turn at the target turning curvature.
This allows the vehicle to turn stably according to the turning curvature.

(8) The distance in the lane width direction between the predicted trajectory and the lane boundary may be calculated, and if the distance is less than a predetermined threshold, a target turning curvature may be set so that the vehicle travels at a position offset from a point on the predicted trajectory toward the target travel trajectory in the lane width direction.
This allows the vehicle to turn at an appropriate turning position according to the difference between the lane boundary and the predicted trajectory.
(9) The distance in the lane width direction between the predicted trajectory and the target driving trajectory may be calculated, and if the distance is equal to or greater than a predetermined threshold, a target turning curvature may be set so that the vehicle travels at a position offset from a point on the predicted trajectory toward the target driving trajectory in the lane width direction.
This enables turning at an appropriate turning position according to the difference between the target driving trajectory and the predicted trajectory.
(10) When the deviation in the lane width direction between the predicted trajectory and the target driving trajectory is large, the above-mentioned point on the predicted trajectory may be offset by a larger offset amount than when the deviation is small.
This enables turning at an appropriate turning position according to the amount of deviation between the target trajectory and the predicted trajectory.

1... host vehicle, 10... vehicle control device, 11... object sensor, 12... vehicle sensor, 13... positioning device, 14... map database, 15... communication device, 16... navigation device, 17... controller, 17a... processor, 17b... storage device, 18a... driving force source controller, 18b... brake controller, 18c... steering controller, 19a... driving force source, 19b... brake actuator (hydraulic actuator), 19 b...Brake actuator, 19c...Steering actuator, 30...Road boundary generation unit, 31...Travel planning unit, 32...Speed control unit, 33...Trajectory tracking control unit, 34...Deviation amount prediction unit, 35...Departure avoidance control unit, 36...Speed plan correction unit, 37...Braking/driving force calculation unit, 38...Steering torque calculation unit, 40...Trajectory planning unit, 41...Speed planning unit, 50...Predicted trajectory generation unit, 51...Deviation amount calculation unit, 60...Curvature calculation unit, 61...Target speed calculation unit, 62...Selection unit

Claims (11)

Calculating a target driving trajectory of the host vehicle in a lane ahead of the host vehicle;
A speed profile is set, which is a target speed according to a position along the target travel path;
Detecting a current position of the vehicle itself and a current attitude angle of the vehicle itself;
A vehicle control method for performing travel control based on the vehicle's own position and the speed profile so that the travel speed of the vehicle becomes a speed according to the speed profile,
predicting a predicted trajectory, which is a travel trajectory of the host vehicle from a current position of the host vehicle to a predetermined distance ahead, based on the host vehicle position, the attitude angle, and the speed profile;
performing deceleration control for decelerating the host vehicle when a maximum value of a distance in a lane width direction between the predicted trajectory and the target driving trajectory is equal to or greater than a predetermined threshold distance;
A vehicle control method comprising: The vehicle control method according to claim 1, characterized in that in addition to the deceleration control, the vehicle's traveling trajectory is corrected by applying a lateral force in a direction opposite to the direction in which the predicted trajectory deviates from the target traveling trajectory through steering control for turning the steered wheels of the vehicle or braking/driving force distribution control for applying a yaw moment to the vehicle. The vehicle control method according to claim 1, characterized in that the predetermined threshold distance is equal to the distance from the target driving trajectory to the lane boundary. determining whether the target travel trajectory from the current position of the vehicle to a predetermined distance ahead is a turning trajectory;
The vehicle control method according to claim 1, characterized in that the deceleration control is performed when the maximum value of the distance in the lane width direction between the predicted trajectory and the target driving trajectory is equal to or greater than the predetermined threshold distance and the target driving trajectory is a turning trajectory. determining whether the predicted trajectory is located outside the target traveling trajectory in a turning direction;
The vehicle control method according to claim 4, characterized in that the deceleration control is performed only when the maximum value of the distance in the lane width direction between the predicted trajectory and the target driving trajectory is equal to or greater than the predetermined threshold distance, the target driving trajectory is a turning trajectory, and the predicted trajectory is located outside the target driving trajectory in the turning direction. The vehicle control method according to claim 1, characterized in that when the maximum value of the distance in the lane width direction between the predicted trajectory and the target driving trajectory is large, the deceleration control is performed at a greater deceleration than when the maximum value is small. The vehicle control method according to claim 6, characterized in that a target turning curvature is set, and in the deceleration control, the vehicle is decelerated to a speed at which the vehicle can turn at the target turning curvature. Calculating a distance in a lane width direction between the predicted trajectory and a road boundary of the lane;
When the separation distance is equal to or less than a predetermined threshold, the target turning curvature is set so that the vehicle can travel along a position obtained by offsetting a point on the predicted trajectory toward the target travel trajectory in a lane width direction.
The vehicle control method according to claim 7 . Calculating a distance between the predicted trajectory and the target driving trajectory in a lane width direction;
When the separation distance is equal to or greater than a predetermined threshold, the target turning curvature is set so that the vehicle can travel along a position offset from a point on the predicted trajectory toward the target travel trajectory in a lane width direction.
The vehicle control method according to claim 7 . The vehicle control method according to claim 8 or 9, characterized in that, when the deviation in the lane width direction between the predicted trajectory and the target driving trajectory is large, the point on the predicted trajectory is offset by a larger offset amount than when the deviation is small. A sensor for detecting a current position of the vehicle itself and a current attitude angle of the vehicle itself;
A process for calculating a target driving trajectory of the host vehicle in a lane ahead of the host vehicle, a process for setting a speed profile which is a target speed according to a position along the target driving trajectory, and a controller for performing driving control based on the self-position and the speed profile so that the driving speed of the host vehicle becomes a speed according to the speed profile;
A vehicle control device comprising:
The vehicle control device is characterized in that the controller executes a process of predicting a predicted trajectory, which is a driving trajectory from the current position of the vehicle to a predetermined distance ahead, based on the vehicle's own position, the attitude angle, and the speed profile, and a process of performing deceleration control to decelerate the vehicle when a maximum value of a distance in a lane width direction between the predicted trajectory and the target driving trajectory is equal to or greater than a predetermined threshold distance.

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