JP6669640B2 - Trajectory evaluation device, trajectory evaluation method, and trajectory evaluation program - Google Patents

Description

  The present invention relates to a trajectory evaluation device, a trajectory evaluation method, and a trajectory evaluation program.

  Conventionally, the surrounding environment of the own vehicle is recognized, the current risk is set for each object in the recognized surrounding environment, and the current risk is determined according to at least one of a relative speed and a relative acceleration between each object and the own vehicle. In addition to adding the corrected risk levels for each subject, predicting the temporal change in the position of each subject and predicting the temporal change in the added risk levels based on the predicted temporal change in the risk levels. Then, for each position of the own vehicle at each time, the minimum point of the risk is calculated from the current risk in the width direction of the own vehicle at the position, and the turning control amount of the own vehicle is calculated based on at least each minimum point. In addition, there is disclosed an invention of a vehicle driving assistance device that generates an avoidance route of a host vehicle based on a turning control amount and determines a final avoidance route (see Patent Document 1).

Japanese Patent No. 4970156

  In the above-described conventional technology, the minimum point of the risk is calculated exclusively from the risk in the width direction of the own vehicle for each position of the own vehicle at each time, and the turning control amount of the own vehicle is calculated based on the minimum point. I have. For this reason, the calculation accuracy of the risk may not be sufficient.

  The present invention has been made in view of such circumstances, and has as its object to provide a trajectory evaluation device, a trajectory evaluation method, and a trajectory evaluation program that can more appropriately evaluate a trajectory. .

The invention according to claim 1 includes a generation unit (123A, 125A) for generating a future trajectory on which the vehicle travels, a prediction unit (123B, 125B) for predicting a future position of an object around the vehicle, and the generation unit. A plurality of points (coordinates) on the trajectory generated by the unit, each of the plurality of points having different passing timings of the vehicle, between the future position of the object predicted by the prediction unit, An evaluation is performed based on a relative positional relationship in a first direction along the longitudinal direction and a relative positional relationship in a second direction along the width direction of the road, and the trajectory is determined based on the evaluation result for each point. An evaluation unit (123C, 125C) for evaluating, wherein the evaluation unit further proceeds along a route to a preset destination for each of the plurality of points on the track. Evaluated on the basis of conditions related to the divergence of the recommended lanes is determined for each block obtained by dividing the path, the relative positional relationship with respect to at least said first direction, with respect to the object existing in front relative to the vehicle A trajectory evaluation device that performs an evaluation using a threshold value that varies based on the speed of the vehicle, and performs an evaluation using a threshold value that varies based on the speed of the object with respect to the object existing behind the vehicle. It is.

  According to a second aspect of the present invention, in the first aspect of the present invention, the evaluation unit is further configured to determine each of the plurality of points based on a degree of change of the plurality of points on the trajectory in the second direction. The evaluation is performed.

  According to a third aspect of the present invention, in the first aspect of the present invention, the evaluation unit performs an evaluation on each of the plurality of points on the track based on a turning degree of the vehicle.

The invention according to a fourth aspect is the invention according to any one of the first to third aspects, further comprising a determination unit configured to determine a type of the object, wherein the evaluation unit is configured to determine the type of the object. The evaluation criteria are made different based on the type of the object.

According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the generating unit generates the plurality of trajectories, and the evaluation unit generates the plurality of trajectories generated by the generating unit. Is evaluated for each of the orbits, and a trajectory having a good evaluation result is selected.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the generation section repeatedly generates the trajectory until a trajectory having a good evaluation result obtained by the evaluation section is selected.

The invention according to claim 7 , wherein the computer generates a future trajectory on which the vehicle travels, predicts a future position of an object around the vehicle, and calculates a plurality of points on the trajectory, and For each of the plurality of points having different timings, a relative positional relationship between the predicted future position of the object in the first direction along the longitudinal direction of the road and a second positional relationship in the width direction of the road. A trajectory evaluation method for evaluating based on a relative positional relationship with respect to a direction and evaluating the trajectory based on the evaluation result for each point, wherein a plurality of points on the trajectory are evaluated when the trajectory is evaluated. for each further evaluated on the basis of conditions related to the divergence of the recommended lanes is determined for each block obtained by dividing the path to travel along the route to a preset destination, small At least with respect to the relative positional relationship with respect to the first direction, the object existing in front of the vehicle is evaluated using a threshold value that changes based on the speed of the vehicle, and the object is positioned rearward with respect to the vehicle. A trajectory evaluation method for evaluating an existing object using a threshold value that varies based on the speed of the object .

The invention according to claim 8 causes a computer to generate a future trajectory on which the vehicle travels, predict a future position of an object around the vehicle, and determine a plurality of points on the trajectory, For each of the plurality of points having different timings, a relative positional relationship between the predicted future position of the object in the first direction along the longitudinal direction of the road and a second positional relationship in the width direction of the road. A trajectory evaluation program that causes an evaluation to be performed based on a relative positional relationship with respect to a direction and evaluates the trajectory based on the evaluation result for each point. For each of the points, further, based on a condition regarding a deviation from a recommended lane determined for each block obtained by dividing the route in order to proceed along a route to a preset destination. Evaluation was performed, the relative positional relationship with respect to at least said first direction, with respect to the object existing in front relative to the vehicle to perform the evaluation using a threshold that varies based on the speed of the vehicle, said vehicle Is a trajectory evaluation program for causing the object existing behind to be evaluated using a threshold value that fluctuates based on the speed of the object .

According to the invention described in claims 1 to 3 and 7 to 11 , the trajectory can be more appropriately evaluated.

According to the fourth and fifth aspects of the present invention, the trajectory can be more appropriately evaluated based on the speed at which the vehicle and the object approach each other.

According to the sixth aspect of the present invention, it is possible to travel with a sufficient margin particularly for an object that requires attention to approach.

1 is a configuration diagram of a vehicle system 1 using a track evaluation device according to a first embodiment. FIG. 5 is a diagram illustrating a state in which a relative position and a posture of a vehicle M with respect to a traveling lane L1 are recognized by a vehicle position recognition unit 122; It is a figure showing signs that a target track is generated based on a recommended lane. FIG. 9 is a diagram for describing an example of a target trajectory generation method. FIG. 9 is a diagram for describing an example of a target trajectory generation method. It is a figure for explaining interval _Sie and _Wie . It is a figure for explaining penalty function P ₂ (S _i , W _i ). FIG. 11 is a diagram for explaining another example of the target trajectory generation method. 9 is a flowchart illustrating an example of a flow of a process executed by an action plan generation unit 123. 13 is a flowchart illustrating another example of the flow of the process executed by the action plan generation unit 123. It is a lineblock diagram of the vehicle system 2 using the track evaluation device concerning a 2nd embodiment.

  Hereinafter, an embodiment of a trajectory evaluation device, a trajectory evaluation method, and a trajectory evaluation program of the present invention will be described with reference to the drawings.

<First embodiment>
[overall structure]
In the first embodiment, a description will be given assuming that the track evaluation device is applied to an automatic driving vehicle. FIG. 1 is a configuration diagram of a vehicle system 1 using the track evaluation device according to the first embodiment. The vehicle on which the vehicle system 1 is mounted is, for example, a vehicle such as a two-wheeled vehicle, a three-wheeled vehicle, or a four-wheeled vehicle, and its driving source is an internal combustion engine such as a diesel engine or a gasoline engine, an electric motor, or a combination thereof. The electric motor operates using electric power generated by a generator connected to the internal combustion engine or electric power discharged from a secondary battery or a fuel cell.

  The vehicle system 1 includes, for example, a camera 10, a radar device 12, a finder 14, an object recognition device 16, a communication device 20, a HMI (Human Machine Interface) 30, a navigation device 50, and an MPU (Micro-Processing). Unit) 60, a vehicle sensor 70, a driving operator 80, an automatic driving control unit 100, a traveling driving force output device 200, a brake device 210, and a steering device 220. These devices and devices are connected to each other by a multiplex communication line such as a CAN (Controller Area Network) communication line, a serial communication line, a wireless communication network, or the like. Note that the configuration illustrated in FIG. 1 is merely an example, and a part of the configuration may be omitted, or another configuration may be added.

  The camera 10 is a digital camera using a solid-state image sensor such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS). One or a plurality of cameras 10 are attached to an arbitrary portion of a vehicle (hereinafter, referred to as own vehicle M) on which the vehicle system 1 is mounted. When imaging the front, the camera 10 is attached to an upper part of a front windshield, a rear surface of a rearview mirror, or the like. The camera 10 periodically and repeatedly takes images of the periphery of the host vehicle M, for example. The camera 10 may be a stereo camera.

  The radar device 12 radiates radio waves such as millimeter waves around the vehicle M, and detects radio waves (reflected waves) reflected by the object to detect at least the position (distance and direction) of the object. One or a plurality of radar devices 12 are attached to an arbitrary portion of the vehicle M. The radar device 12 may detect the position and the speed of the object by an FM-CW (Frequency Modulated Continuous Wave) method.

  The finder 14 is LIDAR (Light Detection and Ranging or Laser Imaging Detection and Ranging) that measures scattered light with respect to irradiation light and detects the distance to the target. One or a plurality of the viewfinders 14 are attached to arbitrary positions of the host vehicle M.

  The object recognizing device 16 performs sensor fusion processing on the detection results of some or all of the camera 10, the radar device 12, and the finder 14 to recognize the position, type, speed, and the like of the object. The object recognition device 16 outputs a recognition result to the automatic driving control unit 100.

  The communication device 20 communicates with other vehicles existing around the own vehicle M using, for example, a cellular network, a Wi-Fi network, Bluetooth (registered trademark), a Dedicated Short Range Communication (DSRC), or the like, or wirelessly communicates. It communicates with various server devices via the base station.

  The HMI 30 presents various information to the occupant of the host vehicle M and accepts an input operation by the occupant. The HMI 30 includes various display devices, speakers, buzzers, touch panels, switches, keys, and the like.

  The navigation device 50 includes, for example, a Global Navigation Satellite System (GNSS) receiver 51, a navigation HMI 52, and a route determination unit 53, and stores first map information 54 in a storage device such as an HDD (Hard Disk Drive) or a flash memory. Holding. The GNSS receiver specifies the position of the vehicle M based on a signal received from the GNSS satellite. The position of the host vehicle M may be specified or supplemented by an INS (Inertial Navigation System) using the output of the vehicle sensor 70. The navigation HMI 52 includes a display device, a speaker, a touch panel, keys, and the like. The navigation HMI 52 may be partially or entirely shared with the above-described HMI 30. The route determination unit 53 determines, for example, the route from the position of the vehicle M specified by the GNSS receiver 51 (or an arbitrary position input) to the destination input by the occupant using the navigation HMI 52, One is determined with reference to the map information 54. The first map information 54 is, for example, information in which a road shape is represented by a link indicating a road and a node connected by the link. The first map information 54 may include road curvature, POI (Point Of Interest) information, and the like. The route determined by the route determining unit 53 is output to the MPU 60. Further, the navigation device 50 may perform route guidance using the navigation HMI 52 based on the route determined by the route determination unit 53. The navigation device 50 may be realized by a function of a terminal device such as a smartphone or a tablet terminal owned by the user, for example. Further, the navigation device 50 may transmit the current position and the destination to the navigation server via the communication device 20 and acquire the route returned from the navigation server.

  The MPU 60 functions as, for example, a recommended lane determining unit 61, and stores the second map information 62 in a storage device such as an HDD or a flash memory. The recommended lane determining unit 61 divides the route provided from the navigation device 50 into a plurality of blocks (for example, divides the route in units of 100 [m] in the vehicle traveling direction), and refers to the second map information 62 for each block. Determine the recommended lane. The recommended lane determining unit 61 determines which lane to travel from the left. The recommended lane determining unit 61 determines the recommended lane so that the own vehicle M can travel on a reasonable route for proceeding to the branch destination when the route includes a branch point or a merging point.

  The second map information 62 is more accurate map information than the first map information 54. The second map information 62 includes, for example, information on the center of the lane or information on the boundary of the lane. Also, the second map information 62 may include road information, traffic regulation information, address information (address / postal code), facility information, telephone number information, and the like. Road information includes information indicating the type of road, such as expressways, toll roads, national roads, and prefectural roads, the number of lanes, the width of each lane, the slope of the road, and the location of the road (longitude, latitude, height, etc.). (Including three-dimensional coordinates), the curvature of the lane curve, the positions of the merging and branching points of the lane, and information such as signs provided on the road. The second map information 62 may be updated as needed by accessing another device using the communication device 20.

  The vehicle sensor 70 includes a vehicle speed sensor that detects the speed of the host vehicle M, an acceleration sensor that detects acceleration, a yaw rate sensor that detects an angular velocity around a vertical axis, an azimuth sensor that detects the direction of the host vehicle M, and the like.

  The driving operator 80 includes, for example, an accelerator pedal, a brake pedal, a shift lever, a steering wheel, and other operators. A sensor that detects the operation amount or the presence or absence of the operation is attached to the driving operator 80, and the detection result is transmitted to the automatic driving control unit 100 or the traveling driving force output device 200, the brake device 210, and the steering device. It is output to one or both of 220.

  The automatic operation control unit 100 includes, for example, a first control unit 120 and a second control unit 140. The first control unit 120 and the second control unit 140 are each realized by a processor such as a CPU (Central Processing Unit) executing a program (software). Further, some or all of the functional units of the first control unit 120 and the second control unit 140 described below include a large scale integration (LSI), an application specific integrated circuit (ASIC), and a field-programmable gate array (FPGA). ), Or may be realized by cooperation between software and hardware.

  The first control unit 120 includes, for example, an outside world recognition unit 121, a vehicle position recognition unit 122, and an action plan generation unit 130. The external world recognition unit 121 includes an object type determination unit 121A. The action plan generation unit 123 includes a trajectory generation unit 123A, a future position prediction unit 123B, and an evaluation unit 123C. A combination of the object type determination unit 121A, the trajectory generation unit 123A, the future position prediction unit 123B, and the evaluation unit 123C is an example of a trajectory evaluation device.

  The external world recognition unit 121 determines the position of an object in the vicinity of the own vehicle M and the state of the object such as the speed and acceleration based on information input from the camera 10, the radar device 12, and the finder 14 via the object recognition device 16. Recognize. The position of the object may be represented by a representative point such as the center of gravity or a corner of the object, or may be represented by a represented area. The “state” of the object may include acceleration and jerk of both objects, or “action state” (for example, whether or not the vehicle is changing lanes or trying to change lanes).

  Further, the object type determination unit 121A of the external world recognition unit 121 determines the type of the object (large vehicle, ordinary vehicle, truck, two-wheeled vehicle, pedestrian, guardrail, telephone pole, parked vehicle, etc.). The object type determination unit 121A determines the type of the object based on, for example, the size and shape of the object captured by the camera 10, the reception intensity of the radar device 12, and other information.

  The host vehicle position recognition unit 122 recognizes, for example, the lane in which the host vehicle M is traveling (travel lane), and the relative position and attitude of the host vehicle M with respect to the travel lane. The own-vehicle position recognizing unit 122 includes, for example, a pattern (for example, an array of solid lines and dashed lines) of road division lines obtained from the second map information 62 and the vicinity of the own vehicle M recognized from an image captured by the camera 10. The traveling lane is recognized by comparing with the lane marking pattern. In this recognition, the position of the host vehicle M acquired from the navigation device 50 and the processing result by the INS may be added.

  Then, the host vehicle position recognition unit 122 recognizes, for example, the position and posture of the host vehicle M with respect to the traveling lane. FIG. 2 is a diagram illustrating a state in which the host vehicle position recognition unit 122 recognizes the relative position and posture of the host vehicle M with respect to the traveling lane L1. The own-vehicle position recognizing unit 122 performs, for example, a deviation OS from a reference lane (for example, the center of gravity) of the own vehicle M from the traveling lane center CL and a line connecting the traveling lane center CL in the traveling direction of the own vehicle M. The angle θ is recognized as the relative position and attitude of the host vehicle M with respect to the traveling lane L1. Instead of this, the own vehicle position recognizing unit 122 recognizes the position of the reference point of the own vehicle M with respect to any one side end of the own lane L1 as a relative position of the own vehicle M with respect to the traveling lane. Is also good. The relative position of the host vehicle M recognized by the host vehicle position recognition unit 122 is provided to the recommended lane determination unit 61 and the action plan generation unit 123.

  The action plan generation unit 123 determines events to be sequentially executed in the automatic driving so that the vehicle travels in the recommended lane determined by the recommended lane determination unit 61 and can cope with the situation around the own vehicle M. The event includes, for example, a constant speed traveling event traveling in the same traveling lane at a constant speed, a following traveling event following a preceding vehicle, an overtaking event overtaking a preceding vehicle, an avoidance event avoiding an obstacle, a lane change event, There are a merge event, a branch event, an emergency stop event, and a handover event for ending automatic operation and switching to manual operation. In addition, during the execution of these events, an action for avoidance may be planned based on the surrounding situation of the own vehicle M (existence of surrounding vehicles and pedestrians, lane narrowing due to road construction, etc.).

  The action plan generation unit 123 generates a target trajectory on which the vehicle M travels in the future by the functions of the trajectory generation unit 123A, the future position prediction unit 123B, and the evaluation unit 123C. Details of each functional unit will be described later. The target trajectory includes, for example, a speed element. For example, the target trajectory is generated as a set of target points (orbit points) to set a plurality of future reference times for each predetermined sampling time (for example, about 0 comma [sec]) and to reach those reference times. You. Therefore, when the interval between the orbit points is wide, it indicates that the vehicle travels at high speed in the section between the orbit points.

  FIG. 3 is a diagram showing how a target trajectory is generated based on a recommended lane. As shown in the figure, the recommended lane is set to be convenient for traveling along the route to the destination. When approaching a predetermined distance before the recommended lane change point (which may be determined according to the type of event), the action plan generation unit 123 activates a lane change event, a branch event, a merge event, and the like. When it becomes necessary to avoid an obstacle during execution of each event, an avoidance trajectory is generated as shown in the figure.

  The second control unit 140 includes a traveling control unit 141. The traveling control unit 141 controls the traveling driving force output device 200, the braking device 210, and the steering device 220 such that the own vehicle M passes through the target trajectory generated by the action plan generating unit 123 at a scheduled time. I do.

  The traveling driving force output device 200 outputs traveling driving force (torque) for driving the vehicle to driving wheels. The traveling driving force output device 200 includes, for example, a combination of an internal combustion engine, an electric motor, a transmission, and the like, and an ECU that controls these. The ECU controls the above configuration according to information input from the travel control unit 141 or information input from the driving operator 80.

  The brake device 210 includes, for example, a brake caliper, a cylinder that transmits hydraulic pressure to the brake caliper, an electric motor that generates hydraulic pressure to the cylinder, and a brake ECU. The brake ECU controls the electric motor in accordance with the information input from the travel control unit 141 or the information input from the driving operator 80 so that the braking torque corresponding to the braking operation is output to each wheel. The brake device 210 may include, as a backup, a mechanism that transmits a hydraulic pressure generated by operating a brake pedal included in the driving operator 80 to the cylinder via a master cylinder. The brake device 210 is not limited to the configuration described above, and may be an electronically controlled hydraulic brake device that controls an actuator in accordance with information input from the travel control unit 141 and transmits the hydraulic pressure of the master cylinder to the cylinder. Good.

  The steering device 220 includes, for example, a steering ECU and an electric motor. The electric motor changes the direction of the steered wheels by applying a force to a rack and pinion mechanism, for example. The steering ECU drives the electric motor to change the direction of the steered wheels according to the information input from the traveling control unit 141 or the information input from the driving operator 80.

[Orbit determination based on orbit evaluation]
Hereinafter, an example of a target trajectory generation method by the action plan generation unit 123 will be described. The method described below is executed when some of the various events described above are activated.

  FIG. 4 is a diagram for describing an example of a target trajectory generation method. The trajectory generation unit 123A of the action plan generation unit 123 first sets the road surface area in the target lane in the target section in the direction (traveling direction) S along the longitudinal direction of the road and in the direction (lateral direction) along the width direction of the road. ) Assuming a coordinate system with W as an axis, a grid is obtained by virtually dividing the road surface area in two directions with a constant width. The grid division width may be set to be equal in the traveling direction and the horizontal direction, or may be set to be different. The target lane includes, for example, the lane Lp in which the host vehicle M is traveling, and the recommended lane Lr determined by the MPU 60 as described above. There is no particular limitation on the target lane, and it may be set arbitrarily. Although FIG. 4 illustrates a straight road for the sake of simplicity, the same processing can be performed on a curve through some kind of conversion processing.

  The trajectory generation unit 123A sets a trajectory specified by selecting a coordinate in the horizontal direction for each grid in the traveling direction with respect to a grid virtually set as shown in the drawing, as a target trajectory candidate. In the figure, the hatched portion corresponds to one target trajectory candidate. In the drawing, the coordinates in the horizontal direction are expressed in units of one grid, but the coordinates included in the target trajectory candidates may have coordinates below the decimal point in the horizontal direction. The target trajectory candidate passes through a representative point of the host vehicle M (such as the center of gravity as described above). The trajectory generation unit 123A generates, for example, all combinations that can be generated under predetermined constraints as target trajectory candidates.

Hereinafter, it is assumed that the number of grids (the number of coordinates) regarding the traveling direction S in the target section is N, and one target trajectory candidate includes N coordinates. Each coordinate is represented by (S _i , W _i ) (i = 1, 2,..., N). When grids are selected every predetermined number r, one target trajectory candidate includes N / r grids.

For example, the trajectory generation unit 123A determines one coordinate ahead (S _{i + 1} , W _{i + 1} ) based on a certain coordinate (S _i , W _i ) by selecting one discretized inclination (input). I do. FIG. 5 is a diagram for describing an example of a target trajectory generation method. As shown in the drawing, the trajectory generation unit 123A sets an upper limit for the inclination with respect to the traveling direction S for a certain coordinate (S _i , W _i ), and increments a finite number of angles by a predetermined angle within the range up to the upper limit. Is set, and the coordinates at the destination extended at that angle are determined as options for the next coordinates (S _{i + 1} , W _{i + 1} ) (the above is an example of the “predetermined constraint”). In the figure, five angles θ, 2θ, 0, −θ, and −2θ are illustrated as the finite number of angles. In this way, all the combinations of a series of coordinates obtained from the coordinates (S ₁ , W ₁ ) as the starting point correspond to the target trajectory candidates. The trajectory generation unit 123A of the action plan generation unit 123 may select grids at predetermined intervals in the traveling direction S.

  The future position prediction unit 123B predicts a future position of the object recognized by the external world recognition unit 121. The future position prediction unit 123B predicts the future position of the object, for example, assuming that the object moves at a constant speed. Instead, the future position predicting unit 123B may predict the future position of the object assuming that the object performs the uniform acceleration movement and the constant jerk movement. Further, the future position prediction unit 123B predicts the future position of the object, for example, at a future timing each time the vehicle M moves by one grid in the traveling direction S in the target trajectory candidate. The time required for the own vehicle M to move by one grid in the traveling direction S in the target trajectory candidate depends on the future speed change of the own vehicle M. The future position prediction unit 123B, for example, The future timing is determined as an arbitrary motion that can be predicted, such as a constant speed motion, a constant acceleration motion, a constant jerk motion, or a motion based on a predicted motion model calculated from a probability statistical model.

  The evaluation unit 123C evaluates the target trajectory candidate generated by the trajectory generation unit 123A for each coordinate based on the relative positional relationship with the object and the like, and based on (for example, by adding) the target based on the evaluation result for each coordinate. Evaluate orbit candidates.

  Expression (1) is an expression showing an example of an evaluation method for each coordinate. The smaller the evaluation value Ji represented in this manner, the better the evaluation in the grid.

C1 is a positive constant. W _ref is a lateral position to be targeted, for example, a position corresponding to the center line of the recommended lane Lr. In each grid, as the horizontal position deviates from Wref, (W _i -W _ref ) ² increases, so the value of J _i increases.

C2 is a positive constant. The term multiplied by C2 indicates the amount of variation in the horizontal direction between grids on adjacent target trajectory candidates in the traveling direction. Therefore, in response to a sharp turn to the vehicle M occurs, the value of J _i increases. This term may be a term that becomes larger as the angular velocity or the steering angle (turning degree) generated by running the target trajectory candidate becomes larger.

P ₁ (S _i , W _i ) is a penalty function related to departure from the target lane. P ₁ (S _i , W _i ) is represented, for example, by equation (2). In the equation, | W _i -Wb | indicates the amount of deviation from any side end of the target lane. Note that instead of | W _i −Wb |, a positive constant that is sufficiently large (by adding this, the possibility of selecting the target trajectory candidate becomes extremely low) may be used as an element of the equation.

P ₂ (S _i , W _i ) is a penalty function related to approaching an object. When a plurality of objects exist around the own vehicle M, P ₂ (S _i , W _i ) may be set for each of the objects. P ₂ (S _i , W _i ) is represented, for example, by equation (3). _Sie is an interval in the traveling direction between the own vehicle M and the object, _Wie is an interval in the lateral direction between the own vehicle M and the object, and _Smin and _Wmin are threshold _values . C3 is a positive constant that is sufficiently large (addition thereof makes it very unlikely that the target trajectory candidate is selected). Note that, instead of C3, a value that increases as the distance from the object increases may be used as an element of the equation.

FIG. 6 is a diagram for explaining the intervals _Sie and _Wie . In the illustrated example, it is assumed that the object is another vehicle m. As illustrated in the upper diagram of FIG. 6, when the object exists in front of the host vehicle M, the interval S _ie is, for example, an interval from the representative point R of the host vehicle M to the rear end portion mr of the other vehicle m. is there. Further, as shown in the lower diagram of FIG. 6, when the object exists behind the host vehicle, the interval S _ie is, for example, the interval from the representative point R of the host vehicle M to the front end mf of the other vehicle m. . The interval _Wie is, for example, an interval in the horizontal direction between the representative point of the vehicle M and the representative point of the object. When the object is another vehicle m, the representative point of the object is, for example, a point passing through the center line in the vehicle width direction. Note that such a definition is merely an example, and any definition may be made as long as similar properties are maintained.

FIG. 7 is a diagram for describing the penalty function P ₂ (S _i , W _i ). As illustrated in FIG. 7A, when _Sie ≧ _Smin and _Wie ≧ _Wmin are satisfied, it is estimated that the other vehicle m is traveling on a lane different from the own vehicle M, for example. Since the distance is sufficiently maintained, the penalty function P ₂ (S _i , W _i ) becomes zero.

As shown in FIG. 7B, when _Sie ≧ _Smin and _Wie < _Wmin are satisfied, it is estimated that the other vehicle m is traveling in the same lane as the own vehicle M, Since the distance is sufficiently maintained, the penalty function P ₂ (S _i , W _i ) becomes zero.

As shown in FIG. 7C, when _Sie < _Smin and _Wie ≧ _Wmin are satisfied, the inter-vehicle distance is not sufficient, but the other vehicle m is traveling in a lane different from the own vehicle M. Therefore, even if the host vehicle M accelerates as it is, it is possible to safely pass. Therefore, the penalty function P ₂ (S _i , W _i ) becomes zero.

Then, as shown in FIG. 7D, when _Sie < _Smin and _Wie < _Wmin are satisfied, it is estimated that the other vehicle m is traveling in the same lane as the own vehicle M, and Since the inter-vehicle distance is not sufficiently maintained, the penalty function P ₂ (S _i , W _i ) has a large value C3.

Here, the threshold value W _min is, for example, a constant value, but the threshold value S _min may be a variable value according to the speed as shown in Expression (4). In the formula, v _x is the speed of the own vehicle M when the own vehicle M is behind the other vehicle m, and is the speed of the other vehicle m when the own vehicle M is ahead of the other vehicle m. It is. Further, the value th may be a fixed value or may be set to a different value depending on the event being executed. For example, it may be set smaller in the case of a lane change event and larger in the case of a follow-up traveling event. Also, the threshold value W _min may be a variable value according to the lateral speed of the host vehicle M, similarly to the threshold value S _min .

S _min = v _x × th (4)

Further, the threshold value S _min and / or W _min in the penalty function P ₂ (S _i , W _i ) may be corrected based on the type of the object determined by the object type determination unit 121A. For example, for objects that should particularly avoid approaching (pedestrians, motorcycles, heavy vehicles, etc.), the threshold value S _min and / or W _min may be multiplied by one or more correction factors. As a result, it is possible to travel with an allowance particularly for an object to be avoided.

  If there is a lane narrowing due to a cone or the like placed on the road ahead of the host vehicle M, the cone may be regarded as an object, or the target lane may be considered to be narrow.

When the evaluation value for each coordinate is obtained by Expression (1), the evaluation unit 123C obtains the evaluation value J for the target trajectory candidate based on Expression (5). In the expression, W _N −W _ref is a deviation between the horizontal position of the grid at the end point of the target trajectory candidate and the horizontal position W _ref to be targeted.

  Finally, the evaluation unit 123C selects, for example, a target trajectory candidate having the smallest evaluation value J (highest evaluation) and determines the target trajectory as the target trajectory. Thereby, the trajectory can be more appropriately evaluated.

The method described above is an example in which the horizontal position W _ref to be targeted is determined to be one. The invention is not limited thereto, and a plurality of lateral positions W _ref to be targeted may be set in an overtaking event or an obstacle avoidance event. FIG. 8 is a diagram for explaining another example of the target trajectory generation method. As shown in the figure, when there is another vehicle m traveling at a low speed in front of the own vehicle M and can travel in any of the left and right lanes, the action plan generation unit 123 sets the lateral position W to be the target. _ref is set for each of the left and right lanes (W _ref (1), W _ref (2) in the figure), and an evaluation value J is calculated for each of the lanes, and the smaller (higher evaluation) evaluation value J is obtained. A target trajectory traveling in the lane may be selected. By such processing, the lane can be changed to a side on which a more appropriate trajectory can be generated.

  Hereinafter, the flow of the process of the action plan generation unit 123 will be described using a flowchart. FIG. 9 is a flowchart illustrating an example of the flow of a process performed by the action plan generation unit 123.

  First, the trajectory generator 123A generates a plurality of target trajectory candidates (step S100). Next, the future position prediction unit 123B predicts a future position of an object around the own vehicle M (step S102).

  Next, the evaluation unit 123C selects one candidate for the target trajectory (Step S104), and performs evaluation for each coordinate (Step S106). Then, the evaluation for each coordinate is integrated to evaluate the target trajectory candidate (step S108).

  Next, in step S104, the evaluation unit 123C determines whether all the target trajectory candidates generated in step S100 have been selected (step S110). If it is determined that all the target trajectory candidates have not been selected, the process returns to step S104. On the other hand, when it is determined that all the target trajectory candidates have been selected, the evaluation unit 123C selects the target trajectory candidate having the smallest evaluation value as the target trajectory (Step S112).

  In the flowchart of FIG. 9, among the plurality of target trajectory candidates, the one having the smallest evaluation value is selected. Alternatively, a process as described below may be performed. FIG. 10 is a flowchart illustrating another example of the flow of the process executed by the action plan generation unit 123.

  First, the future position prediction unit 123B predicts a future position of an object around the own vehicle M (step S200).

  Next, the trajectory generating unit 123A generates a target trajectory candidate (Step S202). Next, the evaluation unit 123C performs evaluation for each coordinate (Step S204), and evaluates a candidate for the target trajectory by integrating the evaluation for each coordinate (Step S206).

  Next, the evaluation unit 123C determines whether or not the evaluation value of the target trajectory is equal to or less than the reference value (Step S208). If the evaluation value of the target trajectory exceeds the reference value, the process returns to step S202, and the trajectory generation unit 123A generates another target trajectory candidate. On the other hand, when the evaluation value of the target trajectory is equal to or smaller than the reference value, a candidate for the target trajectory is determined as the target trajectory (step S210).

  According to the vehicle system 1 (trajectory evaluation device) of the first embodiment described above, for each grid on the trajectory generated by the trajectory generation unit 123A, the future position of the object predicted by the future position prediction unit 123B and The evaluation is performed based on the relative positional relationship in the first direction (S) along the longitudinal direction of the road and the relative positional relationship in the second direction (W) along the width direction of the road, By evaluating the trajectory based on the evaluation result for each coordinate, the trajectory can be more appropriately evaluated.

<Second embodiment>
In the second embodiment, a description will be given assuming that the trajectory evaluation device is applied to a driving support device that performs driving support such as changing lanes. FIG. 11 is a configuration diagram of a vehicle system 2 using the track evaluation device according to the second embodiment. 11, components having the same functions as those in FIG. 1 are denoted by the same reference numerals. Therefore, the description thereof will not be repeated.

  The vehicle system 2 automatically changes lanes based on an operation performed on an ALC (Auto Lane Change) switch 40. For example, the ALC switch 40 is also used as a direction indicator. The driving support unit 100A includes a lane change control unit 125 instead of the action plan generation unit 123 in the first embodiment. When the ALC switch 40 is operated, the lane change control unit 125 performs a predetermined condition (for example, the speed of the own vehicle M is within a specified range, and the distance to a nearby vehicle is maintained at a reference value or more). When the condition is satisfied, the lane is automatically changed.

  When automatically changing lanes, the trajectory generation unit 125A, future position prediction unit 125B, and evaluation unit 125C determine a target trajectory. These functions are the same as the functions of the trajectory generation unit 123A, future position prediction unit 123B, and evaluation unit 123C in the first embodiment.

  According to the vehicle system 2 (track evaluation device) of the second embodiment described above, the track can be more appropriately evaluated as in the first embodiment.

  As described above, the embodiments for carrying out the present invention have been described using the embodiments. However, the present invention is not limited to these embodiments at all, and various modifications and substitutions may be made without departing from the gist of the present invention. Can be added.

Reference Signs List 100 Automatic driving control unit 100A Driving support unit 120 First control unit 121 External world recognition unit 121A Object type determination unit 122 Own vehicle position recognition unit 123 Action plan generation unit 123A Trajectory generation unit 123B Future position prediction unit 123C Evaluation unit 125 Lane change control Unit 125A trajectory generation unit 125B future position prediction unit 125C evaluation unit 140 second control unit 141 travel control unit

Claims (8)

A generation unit that generates a future trajectory on which the vehicle travels;
A prediction unit that predicts a future position of an object around the vehicle,
A plurality of points on the trajectory generated by the generation unit, for each of the plurality of points at different passing timing of the vehicle, the length of the road between the future position of the object predicted by the prediction unit An evaluation is performed based on a relative positional relationship in a first direction along a direction and a relative positional relationship in a second direction along a width direction of the road, and the trajectory is evaluated based on an evaluation result for each point. Evaluation department
With
The evaluation unit,
For each of the plurality of points on the track, further, based on a condition relating to a deviation from a recommended lane determined for each block obtained by dividing the route in order to proceed along a route to a preset destination. Perform an evaluation,
At least with respect to the relative positional relationship in the first direction, the object existing in front of the vehicle is evaluated using a threshold value that changes based on the speed of the vehicle, and the object is present behind the vehicle. For the object to perform an evaluation using a threshold that varies based on the speed of the object,
Orbit evaluation device. The evaluation unit, for each of the plurality of points, further performs an evaluation based on the degree of change in the second direction of the plurality of points on the track.
The trajectory evaluation device according to claim 1. The evaluation unit, for each of the plurality of points on the track, further performs an evaluation based on the turning degree of the vehicle,
The trajectory evaluation device according to claim 1. A determination unit configured to determine a type of the object,
The evaluation unit, based on the type of the object determined by the determination unit, different evaluation criteria,
The trajectory evaluation device according to claim 1 . The generation unit generates a plurality of the trajectories,
The evaluation unit evaluates each of the plurality of trajectories generated by the generation unit, and selects a trajectory having a favorable evaluation result.
The trajectory evaluation device according to claim 1 . The generation unit repeatedly generates the trajectory until a trajectory having a favorable evaluation result obtained by the evaluation unit is selected.
The trajectory evaluation device according to claim 5 . Computer
Generate a future trajectory on which the vehicle will travel,
Predicting the future position of objects around the vehicle,
A plurality of points on the track, each of which has a different passing timing of the vehicle, related to a first direction along the longitudinal direction of the road between the predicted future position of the object and each of the plurality of points. The evaluation is performed based on the relative positional relationship and the relative positional relationship in the second direction along the width direction of the road,
Evaluating the trajectory based on the evaluation result for each point;
An orbit evaluation method,
When evaluating the trajectory,
For each of the plurality of points on the track, further, based on a condition relating to a deviation from a recommended lane determined for each block obtained by dividing the route in order to proceed along a route to a preset destination. Perform an evaluation,
At least with respect to the relative positional relationship in the first direction, the object existing in front of the vehicle is evaluated using a threshold value that changes based on the speed of the vehicle, and the object is present behind the vehicle. For the object to perform an evaluation using a threshold that varies based on the speed of the object,
Orbit evaluation method. On the computer,
Generate a future trajectory on which the vehicle will travel,
Predict the future position of objects around the vehicle,
A plurality of points on the track, each of which has a different passing timing of the vehicle, related to a first direction along the longitudinal direction of the road between the predicted future position of the object and each of the plurality of points. The evaluation is performed based on the relative positional relationship and the relative positional relationship in the second direction along the width direction of the road,
Causing the trajectory to be evaluated based on the evaluation result for each point;
Orbit evaluation program,
When evaluating the trajectory,
For each of the plurality of points on the track, further, based on a condition relating to a deviation from a recommended lane determined for each block obtained by dividing the route in order to proceed along a route to a preset destination. Let them evaluate
At least for the relative positional relationship with respect to the first direction, the object existing in front of the vehicle is evaluated using a threshold value that fluctuates based on the speed of the vehicle, and the object is positioned rearward with respect to the vehicle. With respect to the object that is present, the evaluation is performed using a threshold that varies based on the speed of the object,
Orbit evaluation program.

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