JP6308032B2 - System and method for generating driving maneuvers - Google Patents

Description

  The present disclosure relates generally to systems and methods for generating vehicle driving maneuvers.

  In recent years, the behavior of automobiles has become increasingly autonomous. The vehicle may be equipped with driving assistance that automates part of the driving experience. Examples of driving assistance include parking assistance, active brake assistance, adaptive cruise control, and lane keeping / change assistance. Such driving assistance utilizes vehicle architecture components such as sensors, cameras, and GPS to continuously monitor the vehicle and vehicle environment. Information on the vehicle and the vehicle environment is used to generate various driving operations or travel routes of the vehicle. When commanded by the driver, the driving assistance controls the vehicle to perform and execute the driving operation autonomously or semi-autonomously. As a result, the driving burden on the driver is reduced and / or the safety of the driver is improved.

  U.S. Pat. No. 6,170,736 discloses a lane change adaptive cruise control device that generates a desired route for lane center maintenance or lane change driving operations. Therefore, when instructed by the driver, the target vehicle autonomously executes the lane center maintenance or lane change driving operation according to the generated desired route.

  In order to generate a desired route for a lane center maintaining / changing operation, it is assumed that the device of US Pat. Therefore, when other vehicles are also driving in the vicinity of the target vehicle (that is, traffic conditions), such a device cannot safely perform the lane center maintaining / changing operation. Furthermore, the device of Patent Document 1 only generates a control route that the target vehicle follows. In other words, the target vehicle only steers along the steering path at a constant speed while performing the lane center maintaining / changing operation. The device of Patent Literature 1 does not adjust the longitudinal speed by accelerating / decelerating the target vehicle. Therefore, such a device cannot perform driving operations that require acceleration / deceleration in the front-rear direction in addition to steering input, such as overtaking, merging, and passing an intersection.

  Therefore, there is a need for a driving operation generation system that can be implemented in any type of driving situation including traffic conditions. Furthermore, there is a need for a driving maneuver generation system that can perform complex driving maneuvers that require acceleration, deceleration, and / or maneuvering input.

  One object of the present disclosure is to provide a system and method for generating driving operations that account for traffic conditions.

  In one aspect of the present disclosure, the system generates a driving operation for the vehicle. The system includes a driving operation generation unit that generates a plurality of driving operations, a risk level calculation unit that calculates a risk level based on a vehicle environment, and at least a risk level calculated by the risk level calculation unit. Based on a cost calculation unit that calculates the cost of each driving operation, a driving operation evaluation unit that selects a selected driving operation from a plurality of driving operations based on the cost calculated by the cost calculating unit, and a selected driving operation A movement command generation unit that generates a vehicle control command.

  In another aspect of the present disclosure, a method for generating a driving operation of a vehicle includes storing a predetermined driving operation pattern, recognizing a vehicle environment and a vehicle state, and initializing the predetermined driving operation pattern. Generating a plurality of driving operations based on at least one of a predetermined driving operation pattern, a vehicle environment, or a vehicle state. The method calculates a risk based on the environment of the vehicle, calculates a cost of each of a plurality of driving operations based on the risk, and selects a selected driving operation from a plurality of driving operations on a list In other words, based on the cost of each of the plurality of driving operations, rearranging the plurality of driving operations on the list in the ranking order, and executing the selected driving operation to generate the vehicle control command.

  In yet another aspect of the present disclosure, the method includes evaluating a vehicle environment while performing a selected driving operation, calculating a current risk level while performing the selected driving operation, Generating an emergency operation, comparing the current risk level with a risk threshold value, canceling the selected driving operation when the current risk level is higher than the risk threshold value, and from among multiple emergency operations Including selecting a selected emergency operation and performing a selected emergency operation.

  In another aspect of the present disclosure, a method for generating a driving operation of a vehicle includes storing a predetermined driving operation pattern, recognizing a vehicle environment and a vehicle state, and initializing the predetermined driving operation pattern. Generating a plurality of driving operations based on at least one of a predetermined driving operation pattern, a vehicle environment, a vehicle state, or a user request. The method calculates a risk based on the environment of the vehicle, calculates a cost of each of a plurality of driving operations based on the risk, and selects a selected driving operation from a plurality of driving operations on a list Based on the step and the cost of each of the plurality of driving operations, rearranging the plurality of driving operations on the list in order of ranking, and executing the selected driving operation to generate a vehicle control command.

  By inventing the above-described configuration, the system and method for generating a driving operation generates a plurality of driving operations based on a predetermined driving operation pattern, a surrounding environment of the vehicle, a vehicle state, or a user request. The plurality of driving operations are evaluated according to criteria such as risk and cost in order to select the selected driving operation. Then, the selected driving operation is executed autonomously or semi-autonomously. Further, when it is determined that an emergency occurs while executing the selected driving operation, the emergency operation is selected and executed instead of the currently selected driving operation.

  Further scope of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

The objects, features, and advantages of the present disclosure will become more apparent from the following detailed description made with reference to the accompanying drawings.
It is a block diagram of the driving operation generation system by this indication. 2 is a flowchart of a system according to the present invention. 2B is a continuation of the flowchart of the system of FIG. 2A. It is a figure of a predetermined driving operation pattern. It is a figure of the predetermined driving | operation operation pattern divided | segmented into the segment. It is a figure of adjusted driving operation. It is a flowchart of the process which produces | generates several alternative driving | operation operation. FIG. 5 shows a plurality of alternative lateral trajectories generated for a given segment. FIG. 6 shows a plurality of alternative anteroposterior trajectories generated for a given segment. FIG. 5 shows a plurality of alternative combined trajectories generated for a given segment. FIG. 5 shows a plurality of alternative combined trajectories generated for a given segment. It is a figure which shows the produced | generated several alternative driving | operation operation. It is a figure of adjusted driving operation. It is a graph which shows a road outside risk degree curve with respect to the adjusted driving | operation operation of FIG. 7A. 7B is a graph showing an object risk curve for the adjusted driving operation of FIG. 7A. It is a graph which shows the road shape risk degree curve with respect to the adjusted driving operation of FIG. 7A. It is a graph which shows the total risk curve with respect to the adjusted driving | operation operation of FIG. 7A. FIG. 6 is an exemplary driving operation for a curved road. FIG. 8B is a graph showing an on-road risk curve for the exemplary driving operation of FIG. 8A. 8B is a graph illustrating an object risk curve for the exemplary driving operation of FIG. 8A. 8B is a graph showing a road shape risk curve for the exemplary driving operation of FIG. 8A. FIG. 8B is a graph showing an overall risk curve for the exemplary driving operation of FIG. 8A. It is a figure of a horizontal direction track cost function component. FIG. 7B is a diagram of identified key factors and key cost factors in each segment of the adjusted driving operation of FIG. 7A. FIG. 7B is a diagram for comparison purposes of the adjusted driving operation of FIG. 7A. 7B is a graph showing an initial cost factor for the lateral jerk of the adjusted driving operation of FIG. 7A. It is a graph which shows the initial cost coefficient with respect to the operation time in the front-back direction of the adjusted driving operation of FIG. 7A. It is a graph which shows the initial cost coefficient with respect to the front-back direction jerk of the adjusted driving | operation operation of FIG. 7A. FIG. 3 is a diagram of a given overtaking operation. 12B is a graph illustrating a risk curve for a given overtaking operation of FIG. 12A. 12B is a graph showing an initial cost coefficient with respect to the operation time in the front-rear direction of the given overtaking operation in FIG. 12A. FIG. 12B is a graph showing an adjusted cost factor for the longitudinal operating time for a given overtaking operation of FIG. 12A. It is a flowchart of the collision check process of selection driving | operation operation. It is a figure of the operation operation after initial adjustment. It is a figure of the lowest total cost driving | operation operation | movement produced | generated from the driving | operation operation | movement adjusted by initial stage. It is a graph which shows the front-back direction speed with respect to the initial adjusted driving operation and the lowest total cost driving operation. It is a graph which shows the longitudinal acceleration with respect to the adjusted driving operation and the lowest total cost driving operation. It is a graph which shows the lateral direction acceleration with respect to the initial adjusted driving operation and the lowest total cost driving operation. It is a figure of emergency operation. It is a figure of emergency operation.

  The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts or features.

  With respect to the present disclosure, referring first to FIG. 1, a driving maneuver generation system 1 resident in a target vehicle is shown. The system 1 includes a digital map 11, a camera 12, and a sensor 14 for detecting the environment around the target vehicle, such as road markings, other vehicles, stationary objects, traffic signs, and the like. Sensor 14 may include a radar, lidar, stereo, sonar, and / or infrared sensor. Furthermore, the camera 12 and the sensor 14 may be mounted at various positions around the front, side, and / or rear of the target vehicle. It should be understood by those skilled in the art that the system 1 is not limited to a particular number, position, and / or type of cameras 12 or sensors 14.

  The system 1 also includes a human-machine interface 18 (HMI) for communication and interaction with the driver. The driver may input and / or select the type of driving operation generated by the system 1 and performed by the vehicle using the HMI 18. When the driving operation for execution is generated, the system 1 may request an instruction from the driver through the HMI 18. The driver may also instruct the system 1 to perform or cancel the driving operation through the HMI 18.

  The system 1 receives vehicle state information 16 provided via a local area network (LAN) based on a communication protocol such as a controller area network (CAN). The vehicle state information 16 may include various information related to traveling and / or operation of the target vehicle, such as wheel speed, longitudinal / lateral acceleration, steering angle, yaw, engine rotation speed, and brake operation. The vehicle status information 16 may be determined and provided by the vehicle architecture of the target vehicle and various subsystems. The vehicle state information 16 may also include vehicle position, orientation, and inertia information, such as global positioning system (GPS) position information and inertial measurement unit (IMU) information provided by the navigation device. It should be understood by those skilled in the art that the vehicle state information 16 is not limited to the example of the vehicle state information described above. The vehicle status information 16 may include other types of vehicle information provided by various subsystems residing on the target vehicle that are communicated via the LAN.

  The system 1 includes a controller 10 that receives information provided by a digital map 11, a camera 12, a sensor 14, vehicle state information 16, and an HMI 18. The controller 10 includes a CPU and memories such as a ROM, a RAM, and an EEPROM. The controller 10 also includes a vehicle / environment data processing unit 20, a driving operation generation unit 22, a risk level calculation unit 24, a cost calculation unit 26, a driving operation evaluation unit 28, and an exercise command generation unit 30. The controller 10 processes the information received from the digital map 11, the camera 12, the sensor 14, the vehicle state information 16, and the HMI 18 to generate a driving operation. The controller 10 outputs a control signal to the steering controller 32 and the accelerator / brake controller 34 to execute a driving operation.

  The vehicle / environment data processing unit 20 processes information received from the digital map 11, the camera 12, and the sensor 14 to continuously recognize and monitor the environment around the target vehicle. The vehicle / environment data processing unit 20 specifies the aspect of the road on which the target vehicle is traveling, such as the shape, contour, outer shape, inclination, and curvature. Similarly, the vehicle / environment data processing unit 20 may specify conditions for safe and legitimate driving on the road by specifying aspects such as lane data, road markings, traffic signs, and the like. In addition, the vehicle / environment data processing unit 20 also includes objects, including position, size, mobility, and behavior of stationary / moving objects relative to the target vehicle, such as other vehicles, pedestrians, obstacles on and along the road. The environment surrounding the vehicle may be identified and monitored.

  The driving operation generation unit 22 generates a plurality of alternative driving operations, from which the selected driving operation is executed by the target vehicle. The selected driving maneuver may be a driving maneuver that provides maximum passenger comfort (ie low jerk, high smoothness / comfort etc.) and / or maximum safety margin (ie low slip and swing). .

  The plurality of alternative driving operations may be based on a predetermined plurality of driving operation patterns (that is, a comprehensive template of driving operations) that models movement of the vehicle when the driving operation is performed. The predetermined plurality of driving operation patterns model driving operations for any type of driving situation (eg, overtaking vehicle, changing lanes, lane merging, crossing intersections, turning left / right, keeping distance between lanes / maintaining lanes, etc.) May be used. The driving operation generation unit 22 corrects a predetermined driving operation pattern in accordance with vehicle state information, traffic conditions, road and environment modes, and generates an adjusted driving operation. A driving maneuver is a combination of a series of small continuous segments. The driving operation generation unit 22 also randomly changes the start and end conditions of a predetermined driving operation segment in order to generate a plurality of alternative driving operations. The driving operation generation unit 22 also determines whether any of the plurality of alternative driving operations exceeds a vehicle dynamic threshold parameter (for example, maximum lateral / front-rear speed, acceleration, maximum curvature, etc.). May be. Driving operations that exceed the vehicle dynamic threshold parameters may be removed or excluded from consideration as selective driving operations.

  Although described later in detail, the risk level calculation unit 24 calculates the total risk level given to the target vehicle by the surrounding environment when the driving operation is performed. The total risk is used to evaluate a plurality of alternative driving operations generated by the driving operation generation unit 22 in order to select a selected driving operation (that is, a driving operation to be executed). When the driving operation is performed, the risk level calculation unit 24 calculates the total risk level based on various risks and risks given to the target vehicle by the environment surrounding the road and the target vehicle. The risk and risk level may be detected by the digital map 11, the camera 12, and the sensor 14, and may be specified by the vehicle / environment data processing unit 20. The risk level calculation unit 24 determines the total risk according to the risk and risk level. Calculate the degree. Furthermore, the risk level calculation unit 24 may compare the total risk level with a predetermined risk level threshold. If the calculated overall risk exceeds a predetermined risk threshold, the driving operation is considered unsafe and the execution of the driving operation is aborted or an alternative driving operation (ie, a driving operation with a lower overall risk) ) Is executed.

  As will be described in detail later, the cost calculation unit 26 calculates the total cost for executing each of the plurality of alternative driving operations generated by the driving operation generation unit 22. Depending on the total cost of performing the driving maneuver, the system 1 may operate such as passenger comfort (ie jerk, smoothness / comfort etc.) or safety margin (ie slip or swing) when performing the maneuver. It becomes possible to quantify the mode of operation. Furthermore, as will be described later, when calculating the total cost of each of the plurality of alternative driving operations, the driving operation that reduces the total cost of performing the driving operation is preferentially biased by having a lower total cost. (I.e., the possibility of being selected as an execution driving operation may be higher).

  The driving operation evaluation unit 28 sorts and ranks a plurality of alternative driving operations on a list or table (not shown). The plurality of alternative driving operations may be ranked on a list or table in an order based on the total cost of each driving operation. For example, a driving operation with a lower total cost may be ranked above a driving operation with a higher total cost. As a result, the selected driving operation is selected from the list by the driving operation evaluation unit 28. The selected driving operation may be a driving operation on a list having the lowest total cost.

  The movement command generation unit 30 outputs a vehicle control command signal to the steering controller 32 and the accelerator / brake controller 34 so that the target vehicle executes the selected driving operation.

  Further, as will be described in detail later, the driving operation evaluation unit 28 may evaluate and adjust the selected driving operation while executing the selected driving operation (for example, the lowest total cost driving operation). For example, if the vehicle / environment data processing unit 20 detects an object or obstacle that was not initially considered during the generation process of the plurality of alternative driving operations, or the moving object parameter (ie, the surrounding vehicle or object If the overall risk changes due to an inaccurate estimation of position / velocity / acceleration), the driving operation evaluation unit 28 cancels the selected driving operation that is currently being executed and executes an alternative or emergency driving operation instead. Good.

(Predetermined driving operation pattern)
In the following description, reference is made to the flowcharts of FIGS. 2A and 2B. In step S1 of FIG. 2A, the vehicle / environment data processing unit 20 processes the information received by the digital map 11, the camera 12, and the sensor 14 to form a road shape, contour, contour, slope, lane data, The mode of the road on which the target vehicle is traveling, such as a lane or a traffic sign, is specified. Similarly, object size, speed, behavior, lateral / front-rear acceleration, position (determined using any local or global coordinate system of the main vehicle, such as GPS), direction indicators, etc. Various information related to surrounding objects near the target vehicle may be determined. Further, in step S1, the vehicle / environment data processing unit 20 processes the vehicle state information 16 to determine the traveling state of the target vehicle. The vehicle state information may include wheel speed, longitudinal / lateral acceleration, steering angle, yaw, roll, pitch, engine rotation speed, brake operation, GPS information, and the like.

  In step S2, the driving operation generation unit 22 initializes a predetermined driving operation pattern (that is, a comprehensive template for driving operation) in order to generate a driving operation. The predetermined driving operation pattern models the movement of the vehicle when the driving operation is performed. For example, FIG. 3 shows an overtaking when the target vehicle A in the traveling lane 60 overtakes the preceding vehicle B also in the traveling lane 60 by entering the oncoming lane 62 according to the overtaking route 40 of the predetermined driving operation pattern 100. An example of a predetermined driving operation pattern 100 for operation is shown.

  In general, most types of driving operations (eg, overtaking vehicles, changing lanes, lane merging, crossing intersections, turning left / right, keeping distance between lanes / holding lanes, etc.) can be modeled as a plurality of predetermined driving operation patterns. Furthermore, the predetermined driving operation pattern may be corrected and updated for any type of driving situation. Input parameters (for example, speed, acceleration, steering angle, etc.) of a predetermined driving operation pattern are determined according to driving conditions based on aspects such as speed / acceleration of the target vehicle, distance to an object, lane width, and traffic conditions. It may be modified. Further, the predetermined driving operation pattern for a given driving operation may vary according to the road shape or surrounding objects. In other words, the predetermined driving operation pattern for the overtaking driving operation on the straight road may be different from the overtaking driving operation on the curved road. As will be described later, the predetermined driving operation pattern executes a driving operation such as a risk caused by traveling in an oncoming lane, another vehicle on the road, a road risk level (for example, a curved road or a blind spot), and the like. Does not take into account the risk / risk of

  A plurality of predetermined driving operation patterns for various driving situations may be determined in advance and stored in the memory of the controller 10. Thereby, an appropriate predetermined driving operation pattern may be selected based on the type of driving operation to be performed. It should be understood by those skilled in the art that the present invention is not limited to the above-described driving operations. An arbitrary driving operation may be defined as a predetermined driving operation pattern and stored in the controller 10.

  The predetermined driving operation pattern is further divided into a plurality of smaller continuous segments, whereby the driving operation is simplified into a series of smaller continuous movements each successively executed by the target vehicle. For example, as shown in FIG. 4A, the predetermined driving operation pattern 100 is divided into six segments 110 to 160. Each segment defines a single movement performed by the target vehicle A. In segment 110, the subject vehicle A is implemented by manipulating the lateral distance from the rear of the preceding vehicle B, which is sufficient to reduce the camera 12 and sensor 14 disturbance caused by the preceding vehicle B. Define the driving operation of the center line lateral distance alignment. In other words, when the target vehicle moves a lateral distance, the sensor detection range can be improved. In the segment 120, the target vehicle A defines a longitudinal acceleration adjustment driving operation performed by accelerating / decelerating to a speed suitable for overtaking. In the segment 130, the target vehicle A is operated by manipulating the target vehicle A to have a sufficient lateral distance when entering the oncoming lane 62 from behind the preceding vehicle B in order to safely overtake the preceding vehicle B. Define lane change driving operations. In segment 140, the target vehicle A is implemented by maintaining the speed in the oncoming lane until it overtakes the preceding vehicle B and staying on the oncoming lane 62 to create a safe distance between the target vehicle A and the preceding vehicle B. Define the overtaking operation. In segment 150, the target vehicle A defines a left lane change driving operation performed by returning to the travel lane 60. In segment 160, the target vehicle A performs a longitudinal speed adjustment driving operation performed by reducing the longitudinal speed in order for the target vehicle A to return to a safer speed suitable for normal driving on the road. Define. In this way, the predetermined driving operation pattern 100 is formed by combining the segments 110 to 160.

(Initial length and end time)
In FIG. 4A, each segment of the predetermined driving operation pattern 100 has an initial length d _si and an initial end time t _si . An initial length d _si and an initial end time t _si are calculated to determine the start time, end time, and length of each segment. For example, in the following, a method for calculating the initial length d _si and the initial end time t _si is presented. The initial length d _si and the initial end time t _si are the initial speed (v ₁ ) of the target vehicle A, the initial speed (v ₂ ) of the preceding vehicle B, and the distance (d ₁₎ between the target vehicle A and the preceding vehicle B. ), Travel distance after overtaking (d ₂ ), safety distance before lane change (s _f ), and safety distance after lane change (s _b ), etc., based on the input parameters of target vehicle A and preceding vehicle B Is done. Furthermore, the initial length d _si and the initial end time t _si are calculated using the factors k _i and α _i . The factors k _i and α _i are determined by experiment / simulation and are used as weighting factors to adjust driving maneuvers depending on, for example, the desired degree of smoothness / comfort or safety margin. The factors k _i and α _i will be described in more detail later.

The initial length d _si and the initial end time t _si of each segment of the predetermined driving operation pattern 100 are calculated by inputting the input parameters and the factors k _i and α _i into the following equations (1) to (12). Is done.
( _Equation 1) d _s1 = k ₁ · d ₁
( _Expression 2) t _s1 = d _s1 / [α ₁ (v ₁ −v ₂ )]
( _Expression 3) d _s2 = k ₂ · d ₁
(Number _{4) t s2 = t s1 +} d s2 / [α 2 (v 1 -v 2)]
( _Equation 5) d _s3 = k ₃ · s _f
(Number _{6) t s3 = t s2 +} s f / [α 3 (v 1 -v 2)]
( _Expression 7) d _s4 = k ₄ · s _b
(Number _{8) t s4 = t s3 +} s b / [α 4 (v 1 -v 2)]
( _Equation 9) d _s5 = k ₅ · d ₂
(Number _{10) t s5 = t s4 +} d s5 / [α 5 (v 1 -v 2)]
( _Expression 11) d _s6 = k ₆ · d ₂
(Number _{12) t s6 = t s5 +} d s6 / [α 6 (v 1 -v 2)]

In step S2 of FIG. 2A, the driving operation generating unit 22 calculates an initial segment length _d s1 _{to d s6} and initial end time _t s1 _{~t s6,} initial starting in each segment of the predetermined driving operation pattern / Determine the end time and length. The predetermined driving operation pattern takes into account the risk / risk of performing the driving operation, such as the risk of driving in the oncoming lane, other vehicles on the road, and the road risk (eg, curved road or blind spot). Not put in. For example, referring to the predetermined driving operation pattern 100 of FIG. 4A, since the predetermined driving operation pattern 100 does not take into account the presence of the oncoming vehicle, in the scenario where the vehicle approaches the oncoming lane 62, the initial segment length The length d _s1 to d _s6 and the initial end time t _{s1 to} t _s6 may be too long to safely execute the predetermined driving operation pattern 100. Therefore, to safely implement the driving operation for the actual traffic conditions, the initial segment length _d s1 _{to d s6} and initial end time _t s1 _{~t s6} of each segment adjusting (i.e., shortening) and be I must.

(Generation of adjusted driving operations)
In step S3 of FIG. 2A, the driving operation generating unit 22 adjusts the initial length of the segments of the predetermined driving operation pattern _d s1 _{to d s6} and initial end time _t s1 _{~t s6,} generating a conditioned driving operation . For illustration, FIG. 4B shows an adjusted driving operation 200 for overtaking the preceding vehicle B when the oncoming vehicle C is approaching and the preceding vehicle D is in front of the preceding vehicle B. The adjusted driving operation 200 is based on a predetermined driving operation pattern 100. Although the predetermined driving operation pattern does not consider the presence of actual real-time traffic, the predetermined driving operation pattern provides a basis for calculating the driving operation when there is traffic on the road. In other words, the predetermined driving operation pattern is modified to generate an adjusted driving pattern that takes into account the presence of actual real-time traffic.

In FIG. 4B, the target vehicle A needs the adjusted overtaking path 42 in order to consider the oncoming vehicle C and the preceding vehicle D. Compared to the overtaking path 40 of the predetermined driving operation pattern 100 in FIG. 4A, which does not consider actual real-time traffic and obstacles on the road, the overtaking path 40 has a number of initial segment lengths d _s1 to d _s6 . Because it is too long and some of the initial end times t _{s1 to} t _s6 are too long to cause a collision with the oncoming vehicle C and / or the preceding vehicle D. It is inappropriate. Therefore, consider real-time traffic, requiring adjustment or shortening of the initial segment length _d s1 _{to d s6} and initial end time _t s1 _{~t s6.}

Using the relative speeds and distances of all detected objects provided by the vehicle information 16 of the target vehicle A, the adjusted segment lengths d ′ _s1 to d ′ _s6 and the adjusted end time of the segments 210 to 260 are used. t ′ _{s1 to} t ′ _s6 are adjusted to initially shorten the segment with respect to traffic conditions (ie, preceding vehicles B, D and oncoming vehicle C), as shown in FIG. 4B. For example, the adjusted segment length d ′ _s1 and the adjusted end time t ′ _s1 of the segment 210 are reduced to provide more distance and time for the remaining segments 220-260. The adjusted segment length d ′ _s2 and the adjusted end time t ′ _s2 of the segment 220 are increased to provide faster speed and acceleration when overtaking the preceding vehicle B. The adjusted segment length d ′ _s3 and the adjusted end time t ′ _s3 of the segment 230 are reduced so that the risk of a collision with the oncoming vehicle C is minimized. Since the target vehicle A travels on the oncoming lane 62 while the oncoming vehicle C is approaching, the adjusted end time t ′ _s4 of the segment 240 is reduced. Since the target vehicle A returns to the travel lane 60 with the oncoming vehicle C approaching, the adjusted segment length d ′ _s5 and the adjusted end time t ′ _s5 of the segment 250 are reduced. The adjusted segment length d ′ _s6 and adjusted end time t ′ _s6 of the segment 260 are reduced to minimize the risk of colliding with the preceding vehicle D.

(Generate multiple alternative driving operations based on adjusted driving operations)
In step S4 of FIG. 2A, the driving operation generation unit 22 generates a plurality of alternative driving operations based on the adjusted driving operation. Referring to the example of FIG. 4B, the adjusted segment length d _'s1 ~d' _s6 and the adjusted end time t _'s1 ~t' _s6 of the adjusted driving operation 200, for generating a plurality of alternate driving operation Play a fundamental role. As described above, the driving operation generation unit 22 generates a plurality of alternative driving operations, and the selected driving operation is selected from the generated alternative driving operations and is executed by the target vehicle. The selected driving operation may be a driving operation that provides the smoothest and safest driving operation.

  As described above, the driving operation is divided into a series of continuous segments. Therefore, the alternative driving operation of the target vehicle A can be generated by calculating a plurality of alternative tracks for each segment. Similarly, alternative driving maneuvers may be generated by combining multiple alternative trajectories for each segment.

Alternate trajectories for each segment may be calculated by using fourth and fifth order polynomials. A transverse trajectory may be generated using a fifth order polynomial to generate a single alternative driving operation for a given segment. Similarly, a fourth order polynomial may be used to generate a longitudinal trajectory for a given segment. The lateral trajectory and the longitudinal trajectory may then be combined to generate a vehicle trajectory for a given segment. Based on the adjusted driving conditioned segment length d of operation 200 _'s1 ~d' _s6 and the adjusted end time t _'s1 ~t' _s6, the start point and end point of each segment to randomly generated, Multiple alternative trajectories for a given segment may be generated. Next, a plurality of alternative driving maneuvers may be created by combining a plurality of alternative tracks for each segment with a plurality of alternative tracks for other segments.

More specifically, the lateral trajectory of a given segment may be generated using a fifth order polynomial of equation (13) below.
(Expression 13) y (t) = a ₅ t ⁵ + a ₄ t ⁴ + a ₃ t ³ + a ₂ t ² + a ₁ t ¹ + a ₀

The coefficients a ₀ -a ₅ are determined by specifying dynamic constraints (ie boundary conditions) on the lateral values of position, velocity, and acceleration at the start and end points. The input parameters include the start point and end point of each segment. The start point includes a lateral position y (t ₀ ) at the start point, a lateral speed v _y (t ₀ ) at the start point, and a lateral acceleration a _y (t ₀ ) at the start point. The end point is the lateral position y (t ₀ + Δt) at the end point, the lateral speed v _y (t ₀ + Δt) at the end point, the lateral acceleration a _y (t ₀ + Δt) at the end point, and the lateral operation time. Δt is included.

Similarly, the anteroposterior trajectory of a given segment may be generated using a fourth order polynomial of equation (14) below.
(Expression 14) x (t) = b ₄ t ⁴ + b ₃ t ³ + b ₂ t ² + b ₁ t ¹ + a ₀

Coefficients b ₀ ~b ₄ is determined by specifying the dynamic constraint on the longitudinal direction of the velocity and acceleration at the start point and end point (i.e., boundary conditions). Again, the input parameters include the start and end points of each segment. The starting point input to the mathematical formulas (13) and (14) may be determined by the vehicle state information 16, and the longitudinal speed v _x (t ₀ ) at the starting point and the longitudinal acceleration a _x (at the starting point). t ₀ ) may be included. The end point includes a longitudinal speed v _x (t ₀ + Δt) at the end point, a longitudinal acceleration a _x (t ₀ + Δt) at the end point, and a longitudinal operation time Δt. Further, the end point may be determined by input parameters such as the maximum speed limit of the road (ie, determined by map data or visual road sign recognition) and the maximum allowable acceleration of the system or vehicle. By creating the start and end points in Equations (13) and (14), the front and rear and trajectories are generated, and then the front and rear and trajectories are combined to create a driving operation for a given segment. May be.

(Generate multiple longitudinal and lateral trajectories)
FIG. 5 is a flowchart of a plurality of alternative driving operation generation processes. In step S41 of FIG. 5, the driving operation generation unit 22 generates a plurality of end conditions for each segment in order to generate a plurality of alternative trajectories for each segment. Start point and end point of each segment, based on the adjusted segment length _{d 's1} ~d' _s6 and the adjusted end time _{t 's1 ~t' s6} of the adjusted driving operation 200, it is randomly generated Also good. In other words, to generate multiple alternative trajectories for a given segment, the starting point may be changed by random generation and entered into equations (13) and (14). For example, at the start time, the longitudinal speed v _x (t ₀ ) at the start point, the lateral speed v _y (t ₀ ) at the start point, the longitudinal acceleration a _x (t ₀ ) at the start point, and the start point The lateral acceleration a _y (t ₀ ) is known and received from the CAN of the target vehicle A. The adjusted end times t ′ _{s1 to} t ′ _s6 are known from the calculation of the adjusted driving operation 200, and may be used to change the front-rear operation time Δt by a predetermined amount. More specifically, each of the adjusted end times t ′ _{s1 to} t ′ _s6 may be shortened or extended by a predetermined amount to generate a plurality of alternative trajectories for a given segment. Further, the plurality of alternative trajectories may be generated with a change in the amount (ie, the magnitude) of the lateral and longitudinal acceleration. The lateral and longitudinal accelerations may have values that are within maximum and minimum acceptable lateral and longitudinal acceleration thresholds. Maximum and minimum allowable lateral and longitudinal acceleration thresholds may be predetermined and stored in the memory of the controller 10. The amount of start points and end points that are randomly generated, and the amount of alternative trajectories that are generated may be determined according to the processing capability of the controller 10.

(Combination of multiple tracks to generate alternative driving maneuvers)
In step S42 of FIG. 5, the driving operation generation unit 22 sets the randomly generated start point and end point (that is, according to step S41) to the fourth-order and fifth-order polynomials (that is, the equations (13) and (14)). ) To generate a plurality of lateral and longitudinal trajectories for each segment to generate a plurality of alternative trajectories. 6A shows multiple alternative lateral trajectories for a given segment using Equation (13), and FIG. 6B shows multiple alternative anteroposterior trajectories for a given segment using Equation (14). Show. In step S43 of FIG. 5, the driving operation generation unit 22 combines a plurality of alternative lateral trajectories with a plurality of alternative back-and-forth trajectories to generate a plurality of alternatives for a given segment as shown in FIGS. 6C and 6D. Generate a trajectory. FIG. 6C shows a plurality of alternative trajectories for a given segment having an end point anteroposterior velocity of 40-60 km / hour. FIG. 6D shows a plurality of alternative trajectories for a given segment having an end point longitudinal velocity greater than 80 km / hour. In step S44 of FIG. 5, the plurality of alternative combination tracks of each segment may then be combined with the plurality of alternative combination tracks of other segments to generate a plurality of alternative driving maneuvers. For the sake of explanation, FIG. 6E shows alternative driving operations 1 to 4 of the target vehicle A, which are generated by combining a plurality of alternative combination tracks of each segment.

(Degree of risk)
Among the generated alternative driving operations, the system 1 may select and execute a driving operation that provides the highest level of safety and smoothness / comfort. The risk given to the target vehicle by the surrounding environment and the cost of performing the driving maneuver to determine which of the generated alternative driving maneuvers provides the highest level of safety and smoothness / comfort Based on the above, the plurality of generated alternative driving operations are evaluated.

  In step S5 of FIG. 2A, the risk level calculation unit 24 calculates the total risk level given to the target vehicle by the surrounding environment. In order to determine the overall risk level, the risk level calculation unit 24 analyzes the surrounding environment with respect to various types of risk levels such as a road risk level, an object risk level, and a road shape risk level. The off-road risk level is a risk level given to the target vehicle when the target vehicle travels outside the travel lane (that is, travels other than oncoming lanes, road shoulders, and roadways). The object risk level is a risk level given to the target vehicle by an object on or near the roadway such as another vehicle traveling on the road or a stationary object located along the roadway. The road shape risk is a risk given to the vehicle by the shape of the road (for example, a curved road or a meandering road). It should be apparent to those skilled in the art that the risks described above are merely examples of the many types of risks that are posed to the subject vehicle. The system 1 may be modified to include other types of hazards such as weather, vehicle conditions, road stickiness, and the like.

7A shows a state in which the target vehicle A is about to pass the preceding vehicle B in a state where the preceding vehicle D also travels in the traveling lane 60 and the oncoming vehicle C is approaching in the oncoming lane 62. The adjusted driving operation 200 shown is shown. 7B-7E show risk curves of various risk types for segments 210-260 of adjusted driving operation 200. FIG. FIG. 7B shows an off-road risk curve R _h (t) for the target vehicle A. As the target vehicle A approaches the center line and the oncoming lane 62, the off-road risk curve R _h (t) slightly increases in the segments 210 and 220. In the segment 230, the off-road risk curve R _h (t) increases as the target vehicle A enters the oncoming lane 62. In segment 240, the target vehicle A is traveling on the opposite lane 62, and the off-road risk curve R _h (t) reaches the maximum value for the adjusted driving operation 200. As the target vehicle A returns to the driving lane 60 in the segment 250, the off-road risk curve R _h (t) decreases to a lower value. In the segment 260, the target vehicle A maintains its position in the traveling lane 60, so the off-road risk curve R _h (t) remains at a lower value.

For comparison, FIG. 8A shows an off-road risk curve R _h (t) for a driving operation 300 on a curved road. Similar to the adjusted driving operation 200 shown in FIG. 4B, in the driving operation 300, the target vehicle A is in a state where the preceding vehicle D is traveling in the traveling lane 60 and the oncoming vehicle C is approaching in the facing lane 62. Pass the preceding vehicle B. FIG. 8B shows an on-road risk curve R _h (t) for the driving operation 300. Similar to the off-road risk curve R _h (t) of FIG. 7B, the off-road risk curve R _h (t) increases at the segment 330 as the target vehicle A enters the oncoming lane 62 and at the segment 340. The maximum value is maintained because the target vehicle A is traveling in the oncoming lane 62, and decreases to a lower value as the target vehicle A returns to the travel lane 60 in the segment 350.

7C and 8C show the object risk curves as a result of preceding vehicles B, D and oncoming vehicle C. FIG. The object risk curve for the preceding vehicle B is shown as R _B (t). The object risk curve for the oncoming vehicle C is shown as R _C (t). The object risk curve for the preceding vehicle D is shown as R _D (t). The object risk curves R _B (t), R _C (t), and R _D (t) are respectively the target vehicle A, the preceding vehicle B, and the oncoming vehicle C at the estimated times t _B , t _C , and t _D until the collision. , And the risk level based on the collision probability with each preceding vehicle D. Estimated times t _B , t _C and t _D until the collision are obtained by calculating the relative speeds V _B , V _C and V _D of the preceding vehicle B, the oncoming vehicle C and the preceding vehicle _D and the initial distances d _B , d _C and d _D. May be calculated using. The relative speeds V _B , V _C , V _D and the initial distances d _B , d _C , d _D may be detected by the vehicle sensor 14. The relative velocities V _B , V _C , and V _D may be calculated using equations (15) to (17), and the estimated times t _B , t _C , and t _D until the collision are equations given below: It may be calculated using (18) to (20).
(Expression 15) V _B = v _A −v _B
(Equation 16) V _C = v _C + v _A
(Equation 17) V _D = v _A −v _D
(Equation 18) t _B = d _B / V _B
(Equation 19) t _C = d _C / V _C
(Equation 20) t _D = d _D / V _D

The object risk curves R _B (t), R _C (t), and R _D (t) are calculated using a Gaussian distribution as shown in the following formulas (21) to (23).

In Equations 21, 22, and 23, σ _B , σ _C , and σ _D are noise parameters that are empirically estimated based on sensor noise, time to collision, object visibility, road shape, weather, and the like. is there.

FIG. 7D shows a road shape risk curve R _s (t) for the target vehicle A. The traveling lane 60 and the oncoming lane 62 have a linear shape along the adjusted driving operation 200. Therefore, the road shape risk curve R _s (t) is constant in the segments 210 to 260. For comparison, as shown in FIG. 8D, the road shape risk curve R _s (t) of the curved road may increase with the curvature of the road.

The road shape risk curve R _s (t) may be generated using the following mathematical formula (24).
( ^Equation 24) R _s (t) = e ^{c (t) .λ.t}

  In Expression 24, c (t) is a parameter based on the curvature (1 / m) of the road, and λ is a parameter calculated empirically according to the weather, road, target vehicle conditions, and the like. .

FIGS. 7E and 8E show the total risk R (t) for the adjusted driving operation 200 and the driving operation 300, respectively. The road outside risk curve R _h (t), the object risk curve R _B (t), R _C (t), R _D (t), and the road shape risk curve R _S are shown in Equation (25). Thus, the overall risk R (t) is determined.

In Equation 25, α, β, γ, μ, η are determined empirically based on the importance of the type of risk in different driving scenarios, and z _h , z _B , z _C , z _D , z _S are This is a value for normalizing different risk levels.

  In step S6 of FIG. 2A, the risk level calculation unit 24 compares the total risk level R (t) with the maximum allowable risk level threshold. The maximum allowable risk threshold is shown in FIGS. 7E and 8E. As shown in FIG. 7E, if the overall risk R (t) is below the maximum allowable risk threshold (S6: YES), the driving operation may be a potential selected driving operation (ie, selected and executed). Driving operation). However, if any point of the overall risk R (t) as shown in segments 340 and 350 of FIG. 8E exceeds the maximum allowable risk threshold (S6: NO), it is determined that the driving operation is not safe. The driving operation evaluation unit 28 cancels the selected driving operation, and selects the inter-vehicle distance keeping / lane keeping driving operation in step S8. When the inter-vehicle distance / lane keeping driving operation is selected and executed, the target vehicle maintains a predetermined speed and / or safety distance behind the preceding vehicle in order to minimize the risk to the target vehicle. Also good. The inter-vehicle distance keeping / lane keeping driving operation may be a predetermined default driving operation that is automatically selected when the driving operation is determined to be unsafe and / or canceled.

(Evaluation of alternative operation by cost function)
As described above, the cost calculation unit 26 selects a selected driving operation having the lowest total cost from the generated plurality of alternative driving operations. Therefore, the driving operation having the lowest total cost is the driving operation having the highest safety probability and the highest level of smoothness and comfort among all the generated alternative driving operations. It should be understood by those skilled in the art that the total cost calculation is not limited to criteria such as safety, smoothness, comfort, and operating time.

The total cost of performing the driving operation is a weighted sum of the costs of each segment as shown in the following formula (26).

In Equation 26, as shown in Equations (27) and (28) below, the weight β _i is a function of the overall risk in a given segment i (i = 1,... N), and C _i is The total cost for a given segment i.

The total cost (C _i ) for a given segment i is a weighted sum of the lateral and longitudinal motion costs for a given segment i, as shown in equation (28). The total cost (C _i ) for a given segment i is weighted by α _i determined by experiment / simulation.

The lateral motion cost C _i ^lateral for a given segment i is the lateral jerk, lateral motion time, lateral distance error, heading error (ie, target vehicle trajectory curvature and centerline) Difference between curvature), the degree of smoothness, and the weighted sum of vehicle motion parameters (ie, cost function components in the claims) such as the amount of slip and tail swing. By minimizing the ^lateral cost C _i ^lateral , driving safety, smoothness and comfort are maximized. A function for calculating the ^lateral motion cost C _i ^lateral is expressed by Equation (29), and the vehicle motion parameters are defined by Equations (30) to (35) below.

The above-described cost function component of the ^lateral movement cost C _i ^lateral will be described below with reference to FIG. Referring to Equation 30, lateral jerk is defined as the integral of jerk square, which is used to express the comfort of lateral movement. The lower the lateral jerk, the more comfortable the lateral movement. Referring to Equation 31, the lateral motion time is defined as the motion time limit Δt _i = t _i −t _i−1 , which has a significant impact on safety and comfort. Referring to Equation 32, the lateral distance error is defined as the lateral movement error at the end of the motion. FIG. 9 shows the lateral target distance l _d calculated from the center line information. Referring to Equation 33, the heading direction error is defined as the deviation between the road curvature at the end of the motion and the track curvature of the target vehicle. FIG. 9 shows the road curvature k _d and the vehicle track curvature k (t _i ) at the end of the operation. Referring to Equation 34, smoothness is defined as the integral over the square of the derivative of the arc length of the curvature along the track of the target vehicle. The lower the smoothness value, the smoother the movement by the target vehicle. Referring to Equation 35, regarding slip and tail swing, slip occurs when | k (t) |> k _max (where k (t) is the trajectory curvature of the target vehicle at time t and k _max is Is the maximum curvature). The maximum curvature may be determined based on the design parameters and the current state of the target vehicle. Furthermore, the maximum curvature may be experimentally measured in different states of the target vehicle. Lower and / or zero values of the slip and tail swing components are preferred, and when | k (t) |> k _max there is a loss in the cost function to reduce slip and tail swing.

Vehicle motion parameters as defined by equations (30) - (35), as shown in equation (36), is weighted by the initial cost factor _{K i.}

The sum of all initial cost coefficients k _i ^j , k _i ^t , k _i ^d , k _i ^c , k _i ^s , k _i ^f may be equal to one. When calculating the total cost of driving, different vehicle motion parameters are normalized using the coefficients k _i ^j , k _i ^t , k _i ^d , k _i ^c , k _i ^s and k _i ^f as described below. Specific vehicle motion parameters (ie, lateral jerk, lateral motion time, lateral distance error, heading error, degree of smoothness, and amount of slip and tail swing), etc. It is possible to weight more heavily. Initial cost coefficients k _i ^j , k _i ^t , k _i ^d , k _i ^c , k _i ^s , and k _i ^f for a predetermined driving operation pattern are determined in advance. However, as will be described later, when the total cost of a plurality of alternative driving operations is evaluated and the selected driving operation is selected, the initial cost coefficients k _i ^j , k _i ^t , k _i ^d , k _i ^c , k _i ^s and k _i ^f may be adjusted.

The ^longitudinal motion cost C _i ^longitudinal for a given segment i is a weighted sum of vehicle motion parameters, such as ^longitudinal jerk, longitudinal motion time, and final speed error (ie, cost function component in the claims). . By minimizing the ^longitudinal motion cost C _i ^longitudinal , driving safety, smoothness, and comfort are maximized. A function for calculating the ^longitudinal motion cost C _i ^longitudinal is expressed by Equation (37), and the vehicle motion parameters are defined by Equations (38) to (40) below.

The above-described cost function component of the ^longitudinal motion cost C _i ^longitudinal will be described below. Referring to Equation 38, the forward / backward jerk is defined as the integral of the square of the jerk, which is used to express the comfort of forward / backward movement. The lower the forward / backward jerk, the more comfortable the forward / backward movement. Referring to Equation 39, the forward / backward motion time is defined as the motion time limit Δt _i = t _i −t _i−1 , which has a significant impact on safety and comfort. Referring to Equation 40, the final speed error is defined as the error between the final speed x ′ (t _i ) and the desired speed x ′ _target at the end of the motion.

Vehicle motion parameters as defined by equations (38) - (40), as indicated by equation (41), is weighted by the initial cost factor _{W i.}

The sum of all initial cost factors w _i ^j , w _i ^t , and w _i ^d may be equal to one. When calculating the total cost of the driving operation, as described below, using coefficient ^w _{i ^j,} w _{i ^t,} the w _i ^d, different vehicle motion parameters are normalized, also particular dynamic vehicle motion parameters (I.e., the forward / backward jerk, the forward / backward motion time, and the final speed error) can be weighted more heavily than others. Initial cost coefficients w _i ^j , w _i ^t , and w _i ^d for a predetermined driving operation pattern are determined in advance. However, as will be described later, when evaluating the total cost of a plurality of alternative driving operations and selecting a selected driving operation, the cost coefficients w _i ^j , w _i ^t and w _i ^d may be adjusted.

(Adjustment of initial cost factor)
When evaluating the total cost of each of the plurality of alternative driving operations and selecting the selected driving operation (that is, the lowest cost driving operation), the cost calculation unit 26 gives priority to the specific driving operation and is selected as the selected driving operation. The initial cost coefficients k _i ^j , k _i ^t , k _i ^d , k _i ^c , k _i ^s , k _i ^f , w _i ^j , w _i ^t , and w _i ^d are adjusted so that May be. For example, driving operations that provide shorter operating times, higher safety margins (ie, lower risk), and / or higher levels of smoothness / comfort are likely to have the lowest total cost, The initial cost coefficients k _i ^j , k _i ^t , k _i ^d , k _i ^c , k _i ^s , k _i ^f , w _i ^j , w _i ^t , and w _i ^d are adjusted so as to be selected as the selected operation. May be. That is, such driving maneuvers are related to certain vehicle motion parameters (ie, lateral jerk, lateral movement time, lateral distance error, heading error, degree of smoothness in terms of safety and / or smoothness / comfort. Initial cost coefficients k _i ^j , k _i ^t , so that it is possible to weight the amount of slip and tail swing, longitudinal jerk, longitudinal motion time, and final speed error) more heavily than others. ^{_{k i d, k i c,}} k i s, k i f, w i j, w i t, by adjusting the _w ^{i d,} may be given priority. This provides a higher safety margin and / or a higher level of smoothness / comfort (eg, having a lower value of the smoothness cost function component in the lateral / front-rear cost function). There is an effect that it can be selected. In other words, when evaluating the total cost of multiple alternative driving operations, the total cost of the driving operation that provides a higher safety margin or / and a higher level of smoothness / comfort among the multiple alternative driving operations. In order to emphasize a particular cost function component (eg, by penalizing the deviation), a particular initial cost factor may be preferentially heavily weighted. As a result, when the lowest cost driving operation is selected as the selected driving operation, such driving operation is selected as the selecting operation by having a lower total cost than other driving operations among the plurality of alternative driving operations. Is more likely.

For example, a driving operation that provides a higher safety margin takes precedence over a driving operation that provides a lower safety margin. A driving operation that provides a higher safety margin has a lower degree of risk than a driving operation that provides a lower safety margin. Therefore, if the risk to the target vehicle is reduced by providing higher lateral acceleration and higher longitudinal acceleration / velocity, the initial lateral jerk cost coefficient k _i ^j and initial longitudinal jerk cost coefficient w _i ^j is reduced to provide a wider range of magnitudes that change (ie, increase or decrease) lateral acceleration and longitudinal speed / acceleration (ie, close to the lateral / longitudinal acceleration limit of an automobile). The At the same time, the initial lateral operation time coefficient k _i ^t and the initial front / rear operation time count w _i ^t are increased, and the operation time is shortened. In general, operating time and jerk are strongly related. The larger the jerk, the shorter the operating time, and the smaller the jerk, the longer the operating time. Thus, when calculating the cost of each of the plurality of alternative driving operations, the initial cost factor for the lateral jerk is such that the driving operation that provides higher lateral acceleration and higher longitudinal velocity still has a lower total cost. It may be adjusted to be smaller and lighter in weight (ie, compared to other initial cost factors). Therefore, there is a high possibility that a driving operation having a larger lateral acceleration and / or longitudinal acceleration is selected as the selected driving operation.

  Referring to FIG. 7B for explanation, when a higher lateral acceleration is allowed in the segment 230, the target vehicle A performs a right lane change driving operation with a higher lateral acceleration, and more quickly the oncoming lane 62 You may enter. As a result, the amount of time spent on the oncoming lane 62 is reduced, and as a result, the off-road risk is reduced. When a higher longitudinal speed / acceleration is allowed in the segment 240, the target vehicle A may perform the overtaking driving operation at a higher longitudinal speed and overtake the preceding vehicle B in less time. As a result, the amount of time spent on the oncoming lane 62 is reduced, and as a result, the off-road risk is reduced. When higher lateral acceleration is permitted in the segment 250, the target vehicle A may perform the left lane change driving operation with higher lateral acceleration and return to the traveling lane 60 more quickly. As a result, the amount of time spent on the oncoming lane 62 is reduced, and as a result, the off-road risk is reduced.

  As described above, by providing higher lateral acceleration and higher longitudinal velocity / acceleration, the risk to the target vehicle is reduced, resulting in a higher safety margin when performing the driving operation. Therefore, the initial cost factor for lateral jerk costs and operating time costs is preferentially such that such driving maneuvers have a lower total cost than driving maneuvers that do not provide higher lateral acceleration and higher longitudinal speed. It may be weighted or biased. As a result, there is a high possibility that such a driving operation is selected as the selected driving operation (that is, the lowest cost driving operation).

(Determining which initial cost coefficient is preferentially weighted)
The critical and non-critical factors are used to identify which initial cost factor should be adjusted higher when adjusting the initial cost factor of the vehicle motion parameter, as determined in step S7 of FIG. The Critical and non-critical factors are respectively associated with vehicle motion parameters (ie, cost function components) and initial cost coefficients for vehicle motion parameters. Critical factors are the most critical vehicle motion parameters of driving operations within a given segment that have a greater impact on safety, smoothness, comfort, etc. than non-critical factors. That is, important factors may have a proportionally greater quantitative impact on the total cost of operation compared to non-critical factors. For example, when a driving operation having a higher safety margin is desired as the selected driving operation, the most important factor of the driving operation related to the safety of the driving operation is an important factor. Therefore, in the case of an overtaking operation, important factors such as the overtaking speed and the amount of time spent in the oncoming lane may be important factors that have a proportionally large influence on the total cost of the driving operation.

  Critical factors and non-critical factors may be predetermined according to predefined aspects of the driving operation. Important factors and non-critical factors may be stored in the memory of the controller 10.

For the sake of explanation, in FIG. 7A, when the target vehicle A performs the overtaking operation in the segment 240, the amount of time spent in the oncoming lane 62 is a higher safety margin and / or a higher level in the overtaking operation of the segment 240. May be predetermined as an important factor for providing smoothness / comfort. If there is some increase or decrease in the amount of time spent in the oncoming lane 62, the risk and / or smoothness for the subject vehicle over any other vehicle motion parameter (eg, heading error, lateral error, etc.) / The amount of time spent in the oncoming lane 62 is an important factor because it has a significant impact on comfort. In other words, adjusting the amount of time spent in the oncoming lane 62 may increase / decrease the risk of driving the segment 240 by a greater amount than by adjusting any other vehicle motion parameter. Thus, in the case of a segment 240 overrun operation, the amount of time spent in the oncoming lane 62 can be reduced to further reduce the risk in the segment 240 than adjustments to any other dynamic vehicle motion parameters. . Therefore, the initial cost coefficient associated with an important factor for the overtaking operation of the segment 240 (that is, the amount of time spent in the oncoming lane 62) is w ₄ ^t . Then, the important cost coefficient w ₄ ^t may be adjusted higher so that a plurality of alternative operations including an overtaking operation that reduces the amount of time spent in the oncoming lane 62 is more heavily weighted. As a result, such alternative operations have a lower total cost and are more likely to be selected as the lowest cost operation.

For further explanation, as also shown in FIG. 10 for comparison purposes, key factors for segments 210-260 of adjusted driving operation 200 of FIG. 7A are identified. In segment 210, the subject vehicle A performs a centerline lateral distance alignment driving operation with a lateral distance sufficient to reduce the occlusion effects caused by the preceding vehicle B, behind the preceding vehicle B. Move from. Therefore, the distance (d _c ) to the center line and the difference k _e (t ₁ ) between the curvature of the target vehicle A and the curvature of the center line at time t ₁ are determined in the center line lateral distance alignment driving operation of the segment 210. , Identified as an important factor for providing a higher safety margin and / or a higher level of smoothness / comfort, because the distance to the centerline (d _c ) is the lateral error (ie, Equation (32)) affects the difference k _e (t ₁ ) between the curvature of the target vehicle A and the curvature of the center line at time t _1, and is the head of the lateral motion cost function (ie, Equation (29)). This is because the directional error (that is, the equation (33)) is affected. As a result, in light of equations (29), (32), and (33), k ₁ ^d and k ₁ ^c are important for the centerline lateral distance alignment driving operation in segment 210 as shown in FIG. Cost factor. In addition, k ₁ ^d and k ₁ ^c are adjusted to have higher values to minimize the critical factors of segment 210. By adjusting k ₁ ^d and k ₁ ^c to have higher values, a centerline lateral distance alignment driving operation with less lateral error and less heading error results in more lateral error and It will have a lower total cost than a centerline lateral distance alignment driving operation with more heading error. As a result of having a lower total cost, multiple alternative driving operations are likely to be selected as selection operations, including a centerline lateral distance alignment driving operation with less lateral error and less heading error. Become. In other words, by adjusting k ₁ ^d and k ₁ ^c higher, multiple alternative driving operations with centerline lateral distance alignment driving operations with more lateral errors and more heading errors are more Will have a high total cost, and therefore less likely to be selected as a selection operation.

In the segment 220, the target vehicle A executes a longitudinal acceleration adjustment driving operation and accelerates to a speed sufficient for overtaking. Since the overtaking speed v _x (t ₂ ) and the overtaking acceleration a _x (t ₂ ) affect the final speed error (ie, Equation (40)), the overtaking speed v _x (t ₂ ) and the overtaking acceleration a _x (T ₂ ) is identified as an important factor for providing a higher safety margin and / or a higher level of smoothness / comfort in the longitudinal acceleration adjustment driving operation of segment 220. As a result, w ₂ ^d is an important cost factor for the longitudinal acceleration adjusting driving operation in the segment 220 in light of the mathematical formulas (37) and (40). Furthermore, w ₂ ^d is adjusted to have a higher value to minimize the cost of segment 220. By adjusting w ₂ ^d to have a higher value and adjusting w ₂ ^j to have a lower value, the longitudinal acceleration adjustment driving maneuver may perform an aggressive or abrupt movement. It may have a wider range of magnitudes (ie, near the vehicle's longitudinal acceleration limit) to change (ie, increase or decrease) the longitudinal acceleration as much as possible. A wider range of sizes allows a larger longitudinal acceleration to be selected to reduce the final speed error at the end time of segment 220. By adjusting w ₂ ^j to be lower, a plurality of alternative driving operations including a longitudinal acceleration adjusting driving operation that provides a wider range of magnitudes of the longitudinal acceleration is more likely to be selected as a selection operation. Adjust w ₂ ^j to a lower value to generate a wider range for changing the magnitude of the longitudinal acceleration (ie, allowing selection of the magnitude of the longitudinal acceleration close to the longitudinal acceleration limit of the vehicle) ) by, it is ensured that the selected driving operation has the desired final velocity at time t _2. At the same time, by adjusting w ₂ ^d higher, multiple alternative driving operations with a longitudinal acceleration adjustment driving operation that provides a greater final speed error will have a higher total cost, and thus a selection operation Is less likely to be selected.

In segment 230, the target vehicle A executes a right lane change driving operation, moves to the oncoming lane 62, and safely overtakes the preceding vehicle B. Only place it away. Therefore, the lateral error | d _s −y (t ₃ ) | (where d _s is the lateral safety distance for overtaking the preceding vehicle B, and y (t ₃ ) is the vehicle's Lateral position), as well as heading error k _e (t ₃ ) as important factors to provide a higher safety margin and / or a higher level of smoothness / comfort in the right lane driving operation of segment 230 The reason for this is that the lateral error | ds-y (t ₃ ) | affects the lateral error component (ie, Equation (32)), and the curvature and center of the target vehicle A at time t ₃ . This is because the difference k _e (t ₃ ) from the curvature of the line affects the head error component (ie, equation (33)) of the lateral motion cost function (ie, equation (29)). As a result, in view of the mathematical expressions (29), (32), and (33), k ₃ ^d and k ₃ ^c are important cost coefficients for the right lane change driving operation of the target vehicle A in the segment 230. In segment 230, k ₃ ^d and k ₃ ^c are adjusted to have higher values and k ₃ ^j is adjusted to have lower values. By adjusting k ₃ ^j to have a lower value, a wider range of magnitudes (ie, closer to the vehicle's lateral acceleration limit) to change (ie, increase or decrease) the lateral acceleration is achieved. Provided, lateral and heading errors in the oncoming lane 62 are reduced. At the same time, by adjusting k ₃ ^d and k ₃ ^c to have higher values, a centerline lateral distance alignment driving operation with less lateral error and less heading error results in a larger lateral direction. It will have a lower cost compared to centerline lateral distance alignment driving operations with errors and larger heading errors. As a result of having a lower total cost, multiple alternative driving operations are likely to be selected as selection operations, including a centerline lateral distance alignment driving operation with less lateral error and less heading error. Become. In other words, by adjusting k ₃ ^d and k ₃ ^c higher, multiple alternative driving operations, including centerline lateral distance alignment driving operations with larger lateral errors and larger heading errors, are more Will have a high total cost, and therefore less likely to be selected as a selection operation.

In the segment 240, the target vehicle A creates a safety distance between the target vehicle A and the preceding vehicle B by performing a passing operation that passes the preceding vehicle B and stays in the oncoming lane 62. Since traveling on the oncoming lane 62 is dangerous for the target vehicle A (ie, has a high overall risk), the operation time in the front-rear direction of the segment 240 should be minimized and the risk of the segment 240 should be reduced. It is. Therefore, the time to completion Δt ₄ = t ₄ −t ₃ is an important factor for providing a higher safety margin and / or a higher level of smoothness / comfort in the segment 240 overrun operation, This is because the time Δt ₄ = t ₄ −t ₃ until completion affects the operation time in the front-rear direction (that is, Equation (39)). As a result, in view of Equation (37) and Equation (39), w ₄ ^t is specified as an important cost factor for the overtaking operation in the segment 240. In segment 240, w ₄ ^t is adjusted to have a higher value and w ₄ ^j is adjusted to have a lower value. Adjusting w ₄ ^j to a lower value provides a wider range of magnitudes (ie, closer to the vehicle's longitudinal acceleration limit) to change (ie, increase or decrease) longitudinal acceleration, The operation time in the front-rear direction is reduced. At the same time, by adjusting w ₄ ^t to have a higher value, the overtaking operation with a shorter front-rear operating time has a lower cost compared to a driving operation with a longer front-rear operating time. Become.

In the segment 250, the target vehicle A returns to the traveling lane 60 by executing the left lane change driving operation. Thus, the time to completion Δt ₅ = t ₅ -t ₄ and the heading error k _e (t ₅ ) are higher safety margins and / or higher levels of smoothness / This is an important factor for providing comfort, because the time to completion Δt ₅ = t ₅ −t ₄ affects the lateral movement time (ie, equation (31)) and the heading error k _{This is because e} (t ₅ ) affects the heading error (ie, Equation (33)). As a result, in light of equations (29), (31), and (33), k ₅ ^t and k ₅ ^c are identified as important cost factors for the left lane change driving operation in segment 250. In segment 250, k ₅ ^t and k ₅ ^c are adjusted to have higher values and k ₅ ^j is adjusted to have lower values. By adjusting k ₅ ^j to a lower value, the lateral acceleration is changed (ie, increased or decreased) so as to reduce the lateral movement time in the oncoming lane 62 and reduce the heading error. A wider range of sizes (i.e., close to the lateral acceleration limit of the vehicle) is provided. At the same time, by adjusting k ₅ ^t and k ₅ ^c to have higher values, the left lane change driving operation with shorter operating time and less heading error will result in longer driving time and higher direction. Having a lower cost compared to a left lane change driving operation that provides a heading error will be preferentially weighted or biased.

In the segment 260, the target vehicle A reduces the front-rear direction speed by executing the front-rear direction speed adjustment operation so as to return to the normal operation speed. As such, the final speed v _x (t ₆ ) is identified as an important factor to provide a higher safety margin and / or a higher level of smoothness / comfort in the forward and backward speed regulation operation of the segment 260. This is because the final speed v _x (t ₆ ) affects the final speed error (ie, equation (40)). As a result, w ₆ ^d is an important cost factor for the overtaking operation in the segment 260 in light of the mathematical formulas (37) and (40). In segment 260, w ₆ ^d is adjusted to have a higher value and w ₆ ^j is adjusted to have a lower value. By adjusting w ₆ ^j to have a lower value, the longitudinal speed adjustment driving operation changes the longitudinal acceleration to reduce the longitudinal speed error at the end time of segment 260 (ie, To have a wider range of sizes (ie, near the vehicle's longitudinal acceleration limit), thereby reducing the risk.

To further illustrate the weighting of the cost factor, the adjusted driving operation 200 of FIG. 7A is also shown in FIG. 11A for comparison purposes, and with respect to the segments 210-260 of the adjusted driving operation 200, the lateral jerk, the longitudinal operation time, The initial cost factors for the front and back jerk are shown in FIGS. FIG. 11C shows the cost coefficient value w _i ^t for the initial longitudinal operation time for all segments i = 1, 2,... As shown in segment 240, w ₄ ^t is an important cost factor and thus has a high cost factor value in segment 240. Moreover, as shown in FIG. 11B, the segments 230 to 250 have a high value of w _i ^t in order to reduce the longitudinal operation time and the risk level. At the same time, as shown in segments 230-250 of FIGS. 11B and 11D, the initial longitudinal jerk cost coefficient w _i ^j and the initial lateral jerk cost coefficient k _i ^j have low values to reduce the risk. Provides a wider range of magnitudes (ie, near the vehicle's acceleration limits) to change (ie, increase or decrease) acceleration so that aggressive or abrupt movements can be performed within a short operating time To do. Large acceleration close to the acceleration limit of the target vehicle in order to reduce the risk of being in the danger zone or collision with other vehicles due to the low cost coefficient for lateral and longitudinal jerk in segments 230-260 An abrupt driving operation can be generated with

  In other words, under normal driving conditions where the risk is at a normal level, the system 1 may generate smooth patterns for lateral and longitudinal acceleration in order to ensure smoothness and comfort. However, in a dangerous driving condition with a high risk level, the system 1 may generate a rapid acceleration pattern to guarantee the safety of the driving operation. In this case, the comfort of driving may be sacrificed to ensure safety by having a more rapid acceleration pattern. The magnitude of acceleration that generates a sudden acceleration pattern may be determined based on parameters of the target vehicle, such as maximum lateral / front-rear speed, acceleration, vehicle dynamic control system settings, and the like.

  The adjustment of the initial cost factor in the segments 210-260 may be dependent on the selected driving operation towards a specific type of driving operation (i.e., a driving operation that provides a higher safety margin and / or a higher level of smoothness / comfort). It should be understood by those skilled in the art that this is merely an example of a cost factor adjustment to bias the selection. However, when selecting a selected driving maneuver using a cost function, the key factors and cost factors are: maximum performance, passenger comfort, driving conditions, fuel consumption efficiency, and vehicle specific applications (eg, truck, heavy duty) It may be used to bias or balance vehicle motion parameters according to other criteria, such as for use with other types of vehicles, such as cars.

(Adjustment of initial cost factor)
The amount by which the initial cost coefficient is adjusted in step S7 in FIG. 2 is based on the risk curve of the driving operation. Thus, the adjusted cost factor W _i ^t (t) for the operating time may be determined according to Equation (43) and the overall risk r _i (t).
(Expression 43) W _i ^t (t) = w _i ^t · r _i (t)

For illustration purposes, FIG. 12A shows a given overtaking operation of the above example. To calculate W ₄ ^t (t), the overall risk curve r _i (t) for a given overtaking operation is shown in FIG. 12B. In addition, the initial (ie, not updated) cost factor w _i ^t (t) of the fore-and-aft operation time for a given overtaking operation is shown in FIG. 12C. Therefore, the adjusted cost factor W _i ^t (t) for the forward and backward operation time is calculated using Equation (43) and is shown in FIG. 12D. Therefore, the updated cost coefficient W ₄ ^t (t) with respect to the longitudinal operation time is determined. Similar to Equation (43), all other cost factors (ie, k _i ^j , k _i ^t , k _i ^d , k _i ^c , k _i ^s , k _i ^f , w _i ^j , w _i ^d ) are It should be understood by those skilled in the art that, based on the overall risk r _i (t) of a given overtaking operation, it may be similarly updated (ie, K _i ^j (t) = k _i ^j · r _i (t), K _i ^t (t) = k _i ^t · r _i (t), K _i ^d (t) = k _i ^d · r _i (t), etc.).

  Also, since the sum of the longitudinal cost factor and the lateral cost factor is equal to 1, the amount by which the initial cost factor is adjusted may vary according to the type of driving operation for the driving situation (ie, traffic, environment, etc.). .

(Calculation of total cost using adjusted cost factor)
In step S9 of FIG. 2B, the cost calculation unit calculates the total cost of each of the generated plurality of alternative driving operations. The total cost of each of the generated plurality of alternative driving operations may be calculated using Equation (26). Since the weight β _i is a function of the risk in a given segment i, the adjusted weight Β _i for the overall risk r _i (t) is expressed by the following equation (44).

As shown by FIG. 12D, the adjusted cost factor of the lateral motion cost function is not fixed but time dependent. Therefore, to calculate the adjusted ^lateral motion cost AC _i ^lateral using the adjusted cost factor, the adjusted lateral motion cost function is given by equation (45), and the vehicle motion parameter is Defined by (51).

In order to calculate the adjusted ^longitudinal motion cost AC _i ^longitudinal using the adjusted cost factor, the ^longitudinal motion cost function is given by Equation (52), and the vehicle motion parameters are given by Equations (53)-(55) Defined by

(Selective operation selection)
The driving operation evaluation unit 28 selects a selected driving operation from among the plurality of generated alternative driving operations. The selected driving operation may be a driving operation having the lowest total cost among the plurality of generated alternative driving operations. The driving operation evaluation unit 28 determines which of the plurality of generated alternative driving operations has the lowest total cost. The total cost of each of the generated alternative driving operations is calculated using the adjusted cost factor. The lateral motion cost (ie, equation (45)) is calculated using the vehicle motion parameters (ie, equations (46)-(51)) using the adjusted cost factor. Similarly, the longitudinal motion cost (ie, equation (52)) is calculated using vehicle motion parameters (ie, equations (53)-(55)) using the adjusted cost factor.

The cost (C _i ) for a given segment i is calculated by weighting α _i to the sum of the lateral motion cost and the longitudinal motion cost using equation (28). The total cost of driving is calculated by weighting the total cost of all segments of driving using Equations (26) and (44). The total cost of each of the generated driving operations is calculated, and the driving operation having the lowest total cost is selected from all of the plurality of generated alternative driving operations.

  In step S10 of FIG. 2B, the driving operation evaluation unit 28 rearranges and ranks the plurality of alternative driving operations on the list or table in the order based on the total cost of each driving operation or according to the ranking. A driving operation with a lower total cost may be ranked above a driving operation with a higher total cost. In step S11, the driving operation evaluation unit 28 selects the lowest total cost driving operation from the list as the selected driving operation.

  The driving operation evaluation unit 28 also checks the selected driving operation to ensure that the driving operation does not cause a collision of another vehicle or object. Furthermore, the driving operation evaluation unit 28 also checks that no part of the selected driving operation is performed outside the road area. FIG. 13 is a flowchart of the collision check process and rearrangement of driving operations on the list. In step S111 in FIG. 13, the driving operation evaluation unit 28 determines whether the selected driving operation does not cause a collision and is within the roadway region. The driving operation evaluation unit 28 analyzes the selected driving operation with respect to the latest information regarding the surrounding environment, other objects on the road and / or the vehicle (position, acceleration, speed, size, etc.), and the lane, and selects the selected driving operation. To ensure that the target vehicle does not collide with another object / vehicle, or that the target vehicle does not deviate from the roadway area. If it is determined that the selected driving operation does not cause a collision and is performed in the roadway region (S111: YES), the motion command generating unit 30 executes the selected driving operation in step S12. However, if it is determined that the selected driving operation causes a collision between the target vehicle and another object / vehicle or the target vehicle is out of the road area (S111: NO), the selected driving operation is selected from the list in step S112. Removed. Next, the driving operation evaluation unit 28 selects at least one of the plurality of generated alternative driving operations in order to select another lowest total cost driving operation as the selected driving operation from the list of driving operations. Determine whether it contains. When the list of driving operations includes at least one of the plurality of alternative driving operations generated (S113: NO), the driving operation evaluation unit 28 selects the driving operation with the second total cost from the lowest in step S11. The driving operation is selected, and it is determined again whether or not the selected driving operation causes a collision. However, when the list of driving operations is empty and does not include at least one of the plurality of generated alternative driving operations (S113: YES), the driving operation evaluation unit 28 performs the driving operation generation unit 22 in step S114. The execution of the driving operation may be suspended. Furthermore, in step S115, the driving operation evaluation unit 28 may select the inter-vehicle distance keeping / lane keeping driving operation (that is, the predetermined default driving operation in the claims) in order to ensure the safety of the target vehicle. The motion command generator 30 may execute the inter-vehicle distance keeping / lane keeping driving operation in step S12.

(Effect of minimum total cost operation vs. initial adjusted operation)
To illustrate the effect of the selected driving operation with the lowest total cost, the initial adjusted driving operation 200 and the generated lowest total cost driving operation 400 derived from the initial adjusted driving operation 200 are shown in FIG. 14B. Initially adjusted driving operation 200 has segments 210-260, and lowest total cost driving operation 400 has segments 410-460. Again for comparison, FIG. 14C shows the longitudinal speed profile of the initial adjusted driving operation 200 (ie, the solid line) and the lowest total cost driving operation 400 (ie, the dashed line). FIG. 14D shows the longitudinal acceleration profiles of the initial adjusted driving operation 200 (ie, solid line) and the lowest total cost driving operation 400 (ie, broken line). FIG. 14E shows the lateral acceleration profiles of the initial adjusted driving operation 200 (ie, solid line) and the lowest total cost driving operation 400 (ie, broken line).

Comparing the initial adjusted driving operation 200 with the lowest total cost driving operation 400, the lowest total cost driving operation 400 has a shorter segment, a higher front-rear speed, and higher front-rear and lateral acceleration in FIGS. 14D and 14E. Have. Longitudinal and lateral acceleration, the size is increased, the maximum and minimum acceleration threshold _{^{(a x max, a x min}} ), is below the ^{_{(a y max, a y min}} ). As a result, the time to execute and complete the lowest total cost driving operation 400 is shorter than the time to execute and complete the initial adjusted driving operation 200. Therefore, the overall risk and the possibility of a collision with the oncoming vehicle C are reduced.

  More specifically, when comparing the segment of the initial adjusted driving operation 200 to the segment of the lowest total cost driving operation 400, the lowest total cost driving operation 400 is more in line with the centerline lateral distance alignment driving operation in segment 410. Providing high lateral acceleration, so that the subject vehicle A provides lateral distance with a faster driving maneuver than segment 210. As a result, the end time and segment length are reduced compared to the segment 210. In segment 420, the lowest total cost driving operation 400 provides a higher longitudinal acceleration for the longitudinal speed adjustment driving operation, whereby the target vehicle A has a higher rate of change with a higher rate of change than segment 220. Accelerate to. As a result, the end time and segment length are reduced compared to the segment 220. In segment 430, the lowest total cost driving operation 400 provides a higher lateral acceleration for the right lane change driving operation, so that the target vehicle A has a more rapid driving operation than the segment 230 in the oncoming lane 62. to go into. As a result, the amount of time that the target vehicle A travels on the oncoming lane 62 is reduced, and the end time and the segment length are also reduced compared to the segment 230. In segment 440, the lowest total cost driving operation 400 provides a higher front-rear speed / acceleration for the overtaking operation, thereby allowing the target vehicle to overtake the preceding vehicle B earlier than segment 230. As a result, the amount of time that the target vehicle A spends in the oncoming lane 62 is reduced, and the end time and the segment length are also reduced compared to the segment 240. In segment 450, the lowest total cost driving operation 400 provides a higher lateral acceleration for the left lane change driving operation, whereby the subject vehicle A travels from the oncoming lane 62 more quickly than the segment 230. The driving operation to 60 is performed. As a result, the amount of time that the target vehicle A spends in the oncoming lane 62 is reduced, and the end time and segment length are reduced compared to the segment 250. In segment 460, the lowest total cost driving operation 400 provides a higher longitudinal acceleration for the longitudinal speed regulation driving operation, so that the target vehicle A travels at a higher rate of change compared to segment 260. Decelerate to speed. As a result, the end time and segment length are reduced compared to the segment 260.

(Emergency operation)
While a certain driving operation is actually being executed, the driving operation evaluation unit 28 continuously evaluates the surroundings of the target vehicle. In step S13 in FIG. 2B, while the selected driving operation is being executed by the target vehicle, the vehicle / environment data processing unit 20 monitors the surrounding environment of the target vehicle in each segment. Based on the surrounding environment of the vehicle recognized by the vehicle / environment data processing unit 20 in step S14, the driving operation generation unit 22 performs the emergency operation or the corrected driving operation of the running operation for each segment. Is generated. In step S15, the risk level calculation unit 24 evaluates the current total risk level of each segment. The risk level calculation unit 24 compares the current total risk level of the running operation with the risk level threshold. When the driving operation during execution does not exceed the risk threshold (S15: NO), the vehicle / environment data processing unit 20 continues to monitor the next segment of the driving operation during execution. When the running operation exceeds the risk threshold, it is determined that an emergency has occurred. If an emergency has occurred (S15: YES), the driving operation evaluation unit 28 cancels the running operation in step S16, and includes the emergency operation or the corrected driving operation generated by the driving operation generation unit 22. One may be selected. The selected emergency operation or corrected driving operation is then executed by the exercise command generator 30 in step S12.

  The overall risk of driving is initially calculated as having an overall risk below the risk threshold, but may change during the performance of the driving. Changes in overall risk include unexpected changes in the position, speed, behavior, and acceleration of other vehicles or objects, new objects or obstacles that were not initially considered during the process of generating multiple alternative driving maneuvers. May be caused by detection, increased error in critical factors, or increased overall risk caused by inaccurate estimation of moving object parameters (ie, position / velocity / acceleration of surrounding vehicles or objects).

  For illustration, Table 1 is a list of emergency operations generated by the driving operation generator 22 for the segments 220-240 of the adjusted driving operation 200 of FIG. 4B. In operation, emergency operations are continuously generated while driving operations are being performed.

  Referring to Table 1, the execution driving operation of the segment 220 is a longitudinal acceleration adjustment driving operation that accelerates to a speed suitable for passing. During the execution of the longitudinal acceleration adjustment driving operation, the driving operation evaluation unit 28 determines that when the total risk of the segment 220 exceeds the risk threshold while executing the longitudinal acceleration adjustment driving operation, the longitudinal deceleration and the inter-vehicle distance It may be determined that the distance keeping / lane keeping driving operation should be executed. In other words, the longitudinal acceleration adjustment driving operation may be canceled, and the longitudinal deceleration and inter-vehicle distance maintenance / lane keeping driving operation may be selected and executed.

  In the segment 230, the driving operation evaluation unit 28 performs the target when an emergency occurs while performing the longitudinal acceleration adjustment driving operation (that is, when the total risk of the segment 230 exceeds the risk threshold). Instead of executing the right lane change driving operation so that the vehicle A moves to the oncoming lane 62, the forward / rearward deceleration and the left lane change driving operation may be generated and selected. FIG. 15A shows canceling the right lane change driving operation in an emergency (that is, approaching very close to the oncoming vehicle C), and performing the vertical deceleration and the left lane changing operation instead.

  In the segment 240, instead of executing the overtaking operation so as to overtake the preceding vehicle B while the target vehicle A is in the oncoming lane 62, the driving operation is performed in an emergency (that is, close to the oncoming vehicle C). The evaluation unit 28 may generate two emergency operations, select a selected emergency operation from the emergency operations, and execute the selected emergency operation. The first emergency operation A may be a driving operation for longitudinal deceleration and a sudden left lane change. The second emergency operation B may be a driving operation with high longitudinal acceleration and left lane change. FIG. 15B shows both driving paths for both emergency operations. The selected emergency operation may be an emergency operation with the lowest total cost of emergency operations.

(Other embodiments)
In the above-described embodiment, the system 1 generates an overtaking operation so that the target vehicle can autonomously overtake the preceding vehicle. However, a predetermined driving operation pattern for any type of driving operation may be stored in the memory of the controller 10, and these are initialized by the driving operation generating unit 22 to generate any type of driving operation. It should be understood by those skilled in the art that it may be used.

  Furthermore, in the above-described embodiment, the driving operation evaluation unit 28 selects the lowest cost driving operation as the selected driving operation. However, it should be understood by those skilled in the art that the selected driving operation may be selected according to the highest cost, cost range, or specific cost.

  Furthermore, in the above-described embodiment, the driving operation generation unit generates anteroposterior and lateral trajectories using fourth and fifth order polynomials. However, it should be understood by those skilled in the art that any other anteroposterior and lateral trajectory generation methods may be used.

  Furthermore, in the above-described embodiment, any collision check method may be used to determine whether or not a collision with a surrounding object can occur as a result of the driving operation.

  Although the present disclosure has been described in terms of preferred embodiments, those skilled in the art will recognize that the present disclosure can be practiced with modification within the spirit and scope of the appended claims. All such variations and modifications are intended to be within the scope of the appended claims. Accordingly, the examples and drawings are to be regarded as illustrative rather than limiting.

Claims (21)

A system for generating a driving operation of a vehicle,
A driving operation generation unit (22) for generating a plurality of driving operations;
A risk calculation unit (24) for calculating the risk based on the environment of the vehicle;
A cost calculation unit (26) for calculating costs of each of the plurality of driving operations based on at least the risk calculated by the risk calculation unit;
A driving operation evaluation unit (28) for selecting a selected driving operation from a plurality of driving operations based on the cost calculated by the cost calculating unit;
An exercise command generator (30) that generates a vehicle control command based on the selected driving operation,
Each of the plurality of driving operations includes a combination of consecutive unbroken segments,
The cost calculation unit calculates the cost of each segment of each of a plurality of driving operations by using a cost function,
The cost function has a plurality of cost function components,
Each cost function component is weighted by an initial cost factor,
The cost of each segment of the plurality of driving operations is the sum of the cost function components in each segment of the plurality of driving operations,
The cost calculation unit is a system that calculates the cost of each of the plurality of driving operations by summing the costs of each segment of the plurality of driving operations. The system according to claim 1 , wherein the driving operation generation unit generates a plurality of driving operations based on at least one of a predetermined driving operation pattern, a vehicle state, a vehicle environment, or a driver's request. The predetermined driving operation pattern includes lane change driving operation, overtaking driving operation, crossing driving operation, merging driving operation, inter-vehicle distance maintenance, lane keeping, adaptive cruise control, emergency steering, emergency braking, speed assistance, or cooperative driving The system of claim 2 , comprising a pattern that performs at least one of the following. Driving operation generating unit may be any system of claims 1 to 3 for generating a plurality of driving operation by using a polynomial function. Risk calculation unit, risk it is determined whether more than a predetermined risk threshold, if it exceeds a predetermined risk threshold, the driving operation evaluation unit, of claims 1 to 4 cancel the selection driving operation One of the systems. Degree of risk, off-road risk, object risk system of any of claims 1 to 5 or comprising at least one of the road shape risk. Each initial cost factor for each cost function component is associated with an important or non-critical factor,
The critical factor is based on at least one of safety, smoothness, or comfort, and in a given segment, which of the cost function components is proportional to the cost function relative to the non-critical factor Indicate if it has a large quantitative impact,
When calculating the cost of each of the plurality of driving operations, the cost calculation unit calculates the cost function of a given segment associated with the important factor compared to the initial cost coefficient of the cost function component associated with the non-critical factor. The system of claim 1 , wherein the initial cost factor value of the component is considered higher. The system according to claim 1 or 7 , wherein the cost calculation unit adjusts an initial cost coefficient of the cost function component associated with the important factor based on the degree of risk. Each initial cost coefficient of each cost function component is predetermined,
The system according to claim 1 or 7 , wherein the cost calculation unit adjusts the initial cost coefficient of the cost function component associated with the important factor by multiplying the initial cost coefficient by the risk level. The cost function component includes at least one of lateral jerk, longitudinal jerk, operation time, lateral distance error, heading error, degree of smoothness, amount of slip and tail swing, or final speed error. 1. A system according to any one of 7 to 9 . The driving operation evaluation unit rearranges the plurality of driving operations on the list in the order of ranking based on the cost of each of the plurality of driving operations.
Driving operation evaluation unit, from the list, any one of claims 1 to 10 to select the selected driving operation system. The system according to any one of claims 1 to 11 , wherein the driving operation evaluation unit selects a selected driving operation having the lowest cost from a plurality of driving operations. The system according to claim 11 , wherein the driving operation evaluation unit determines whether the selected driving operation causes a collision with an object. The system according to claim 13 , wherein when it is determined that the selected driving operation causes a collision with an object, the driving operation evaluation unit deletes the selected driving operation from the list. When the list does not include at least one of multiple driving operations,
(1) The driving operation generation unit stops generating a plurality of driving operations,
(2) The driving operation evaluation unit selects a predetermined default driving operation,
(3) The system according to claim 14 , wherein the movement command generation unit generates a vehicle control command based on a predetermined default driving operation. The system according to any one of claims 1 to 11 , wherein when the degree of danger is high, the selected driving operation is a driving operation with high acceleration in order to reduce the degree of danger and prevent a collision. The system according to any one of claims 1 to 11 , wherein when the degree of risk is low, the selected driving operation is a driving operation with a low acceleration in order to provide smooth and comfortable driving operation. The system of claim 16 , wherein the high acceleration is determined based on vehicle parameters. A method for generating a driving operation of a vehicle,
Recognize vehicle environment and vehicle condition,
Generating a plurality of driving operations based on at least one of a predetermined driving operation pattern, a vehicle environment, or a vehicle state;
Calculate the risk based on the vehicle environment ,
Calculate the cost of each driving operation based on the risk,
Select the selected driving operation from the multiple driving operations on the list,
A vehicle operation command is generated by executing a selective driving operation ,
Each of the plurality of driving operations includes a combination of consecutive unbroken segments,
By using the cost function, calculate the cost for each segment of each driving operation,
The cost function has a plurality of cost function components,
Each cost function component is weighted by an initial cost factor,
The cost of each segment of the plurality of driving operations is the sum of the cost function components in each segment of the plurality of driving operations,
A method of calculating the cost of each of a plurality of driving operations by summing the cost of each segment of the plurality of driving operations . 20. The method of claim 19 , wherein the selected driving operation has the lowest cost among the plurality of driving operations. further,
Evaluate the vehicle's environment during the selected driving operation,
Calculate the current risk level while performing the selected driving operation,
Generate multiple emergency operations,
Compare the current risk level with the risk threshold,
If the current risk is higher than the risk threshold, cancel the selected driving operation,
Select a selected emergency operation from multiple emergency operations,
21. The method of claim 19 or 20 , wherein a selected emergency operation is performed.

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