JP2019032711A - Determination device, method for determination, and program - Google Patents

Abstract

To appropriately predict a route of a vehicle when the vehicle is travelling at an intersection and determine the risk of the travelling.SOLUTION: The determination device determines the risk of travelling before a moving object actually turns right or left at an intersection. More specifically, the determination device predicts a travelling route when the moving body is travelling at an intersection, on the basis of rate information on the moving rate of the object and intersection information including the shape of the intersection. The determination device detects another moving object around the intersection, and sets a determination position on the travelling route based on another moving body described above. The determination device determines the risk of travelling at the determination position based on the rate information and the travelling route.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a technique for determining a risk at the time of turning right or left at an intersection.

  A technique for stabilizing the running of a vehicle on a curve is known. For example, Patent Document 1 calculates the lateral acceleration generated in the vehicle while traveling on the curve based on the curve shape based on the map information and the current vehicle speed, and the vehicle stably passes the curve based on the lateral acceleration. It describes that it can be determined before and after entering the curve, and the setting of the vehicle stabilization control device is switched according to the determination result.

JP 2010-105453 A

  Compared to the curve, the degree of freedom of the track on which the vehicle travels when passing through the intersection is high, and the vehicle can travel on various tracks. When turning left or right at an intersection, the travel risk changes depending on the vehicle's track, so it is difficult to determine the travel risk before traveling at the intersection.

  The above-mentioned thing is mentioned as an example as a subject of this invention. An object of the present invention is to appropriately predict a trajectory when a vehicle travels an intersection and determine a travel risk.

  The invention described in the claims is a determination device for determining a travel risk before the mobile object actually travels left or right at the intersection, and includes intersection information including speed information related to the moving speed of the mobile object and the shape of the intersection. Based on the traveling path, the predicting section for predicting the traveling path when the traveling body travels the intersection, the detecting section for detecting other traveling bodies around the intersection, and the other traveling body, And a determination unit that determines the travel risk at the determination position based on the speed information and the travel trajectory.

  The invention described in another claim is a determination method that is executed by a determination device that determines a travel risk before the mobile object actually travels left or right at an intersection, and includes speed information related to a travel speed of the mobile object, Based on intersection information including the shape of the intersection, a prediction step for predicting a traveling path when the moving body travels the intersection, a detection step for detecting other moving bodies around the intersection, and the other movement A setting step of setting a determination position on the travel track based on a body; and a determination step of determining the travel risk at the determination position based on the speed information and the travel track.

  The invention described in another claim is a program that includes a computer and that is executed by a determination device that determines a travel risk before the mobile body actually turns right or left at an intersection, and relates to a moving speed of the mobile body Based on speed information, intersection information including the shape of the intersection, a prediction unit that predicts a traveling trajectory when the moving body travels the intersection, a detection unit that detects other moving objects around the intersection, the other The computer is caused to function as a setting unit that sets a determination position on the travel track based on a moving body, and a determination unit that determines the travel risk at the determination position based on the speed information and the travel track. And

It is a block diagram which shows the structure of the navigation apparatus which concerns on an Example. It is a flowchart of the warning process which concerns on an Example. It is a flowchart of an orbit prediction process. An example of setting the start point and end point of the predicted trajectory is shown. It is a flowchart of a travel risk determination process. It is a flowchart of a travel risk determination process. An example of setting the determination position is shown. It is a figure explaining the synthetic acceleration in a judgment position. The example of the end point of the prediction trajectory which concerns on a modification is shown. The example of the setting of the determination position which concerns on a modification is shown.

  In a preferred embodiment of the present invention, the determination device that determines the travel risk before the mobile object actually travels left or right at the intersection includes speed information related to the moving speed of the mobile object, and intersection information including the shape of the intersection. Based on the travel path based on the prediction unit for predicting the travel trajectory when the mobile body travels the intersection, the detection unit for detecting another mobile body around the intersection, and the other mobile body A setting unit that sets a determination position; and a determination unit that determines the travel risk at the determination position based on the speed information and the travel trajectory.

  Said determination apparatus determines a driving | running | working risk, before a mobile body actually carries out the right-left turn traveling at the intersection. The determination device predicts a travel path when the mobile body travels the intersection based on the speed information related to the moving speed of the mobile body and the intersection information including the shape of the intersection. In addition, the determination device detects another moving body around the intersection and sets a determination position on the traveling track based on the other moving body. Then, the determination device determines the travel risk at the determination position based on the speed information and the travel track. Thereby, the driving | running | working risk in the position where another moving body exists can be determined exactly.

  In one aspect of the determination apparatus, when the other moving body is not detected by the detection unit, the setting unit does not set the determination position, and the determination unit does not determine the travel risk. In this aspect, when no other moving body is detected, the setting of the determination position and the determination of the running risk are omitted to reduce the processing load.

  In the other one aspect | mode of said determination apparatus, said other moving body contains moving bodies other than the moving body on an oncoming lane and a pedestrian crossing. In this aspect, the traveling risk can be determined for a moving body other than the moving body on the oncoming lane or the pedestrian crossing.

  In a preferred example, the detection unit detects the other moving body based on at least one of the traffic information around the intersection acquired from the outside and the detection result by the obstacle detection device mounted on the moving body. To detect.

  In another preferred embodiment of the present invention, the determination method executed by the determination device that determines the travel risk before the mobile object actually travels left or right at the intersection includes speed information relating to the travel speed of the mobile object, Based on intersection information including the shape of an intersection, a predicting step of predicting a traveling trajectory when the moving body travels the intersection, a detecting step of detecting other moving bodies around the intersection, and the other moving bodies And a determination step for determining the travel risk at the determination position based on the speed information and the travel trajectory. Also by this method, it is possible to accurately determine the running risk at a position where another moving body exists.

  In another preferred embodiment of the present invention, the program executed by the determination device that includes the computer and determines the travel risk before the mobile body actually turns right or left at the intersection is a speed related to the travel speed of the mobile body. Based on information, intersection information including the shape of the intersection, a prediction unit that predicts a traveling trajectory when the moving body travels the intersection, a detection unit that detects other moving objects around the intersection, and the other movement The computer is caused to function as a setting unit that sets a determination position on the traveling track based on a body, and a determination unit that determines the traveling risk at the determination position based on the speed information and the traveling track. By executing this program on a computer, the above-described determination apparatus can be realized. This program can be stored and handled in a storage medium.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
[Navigation device]
FIG. 1 shows a configuration of a navigation device 1 according to an embodiment of the present invention. As shown in FIG. 1, the navigation device 1 includes a self-supporting positioning device 10, a GPS receiver 18, a system controller 20, a disk drive 31, an obstacle detection unit 32, a data storage unit 36, a communication interface 37, a communication device 38, A display unit 40, an audio output unit 50, and an input device 60 are provided.

  The system controller 20, the disk drive 31, the obstacle detection unit 32, the data storage unit 36, the communication interface 37, the display unit 40, the audio output unit 50, and the input device 60 are connected to each other via the bus line 30. .

  The autonomous positioning device 10 includes an acceleration sensor 11, an angular velocity sensor 12, and a distance sensor 13. The acceleration sensor 11 is made of, for example, a piezoelectric element, detects vehicle acceleration, and outputs acceleration data. The angular velocity sensor 12 is composed of, for example, a vibrating gyroscope, detects the angular velocity of the vehicle when the vehicle changes direction, and outputs angular velocity data and relative azimuth data. The distance sensor 13 measures a vehicle speed pulse composed of a pulse signal generated with the rotation of the vehicle wheel.

  The GPS receiver 18 receives radio waves 19 carrying downlink data including positioning data from a plurality of GPS satellites. The positioning data is used to detect the absolute position of the vehicle (hereinafter also referred to as “current position”) from latitude and longitude information.

  The system controller 20 includes an interface 21, a CPU (Central Processing Unit) 22, a ROM (Read Only Memory) 23, and a RAM (Random Access Memory) 24, and controls the entire navigation apparatus 1.

  The interface 21 performs interface operations with the acceleration sensor 11, the angular velocity sensor 12, the distance sensor 13, and the GPS receiver 18. From these, vehicle speed pulses, acceleration data, relative azimuth data, angular velocity data, GPS positioning data, absolute azimuth data, and the like are input to the system controller 20.

  The CPU 22 controls the entire system controller 20. The ROM 23 includes a nonvolatile memory (not shown) in which a control program for controlling the system controller 20 is stored. The RAM 24 stores various data such as route data preset by the user via the input device 60 so as to be readable, and provides a working area to the CPU 22.

  The disk drive 31 reads music and video data from a CD, DVD, etc. (not shown) and outputs them to the display unit 40 and the audio output unit 50.

  The obstacle detection unit 32 includes, for example, a camera, Lidar (Light Detection and Ranging), and detects obstacles existing around the vehicle, particularly in front of the vehicle. Obstacles include moving objects such as vehicles and pedestrians in addition to features such as buildings.

  The data storage unit 36 is composed of, for example, an HDD and stores various data used for navigation processing such as map data. The communication device 38 performs wireless communication with the server 7 via the network. In addition, the communication device 38 receives surrounding traffic information related to traffic conditions around the vehicle using road-to-vehicle communication or vehicle-to-vehicle communication.

  The display unit 40 displays various display data on a display device such as a display under the control of the system controller 20. The display unit 40 displays the map data read from the data storage unit 36 by the system controller 20 on the display screen. The display unit 40 includes a graphic controller 41 that controls the entire display unit 40 based on control data sent from the CPU 22 via the bus line 30 and a memory such as a VRAM (Video RAM), and can display image information that can be displayed immediately. A buffer memory 42 that temporarily stores, a display control unit 43 that controls display of a display 44 such as a liquid crystal based on image data output from the graphic controller 41, and a display 44 are provided. The display 44 functions as an image display unit, and includes, for example, a liquid crystal display device having a diagonal size of about 5 to 10 inches and is mounted near the front panel in the vehicle.

  The audio output unit 50 is a D / A converter 51 that performs D / A (Digital to Analog) conversion of audio digital data sent from the disk drive 31 or the RAM 24 via the bus line 30 under the control of the system controller 20. , An amplifier (AMP) 52 that amplifies the audio analog signal output from the D / A converter 51, and a speaker 53 that converts the amplified audio analog signal into sound and outputs the sound into the vehicle.

  The input device 60 includes keys, switches, buttons, a remote controller, a voice input device, and the like for inputting various commands and data. The input device 60 is disposed around the front panel and the display 44 of the main body of the in-vehicle electronic system mounted in the vehicle. When the display 44 is a touch panel system, the touch panel provided on the display screen of the display 44 also functions as the input device 60.

  In the above configuration, the system controller 20 is an example of a prediction unit, a detection unit, a setting unit, and a determination unit of the present invention.

[Warning]
Next, warning processing according to the present embodiment will be described. The warning process is a process in which when a vehicle travels an intersection, a driving risk at a specific position in or around the intersection is determined in advance, and a warning is issued as necessary.

  FIG. 2 is a flowchart of the warning process. This process is realized by the system controller 20 (hereinafter, also simply referred to as “controller 20”) of the navigation apparatus 1 shown in FIG. 1 executing a program prepared in advance.

  First, the controller 20 predicts a right / left turn of the vehicle at the intersection (step S11). That is, the controller 20 predicts whether or not the vehicle on which the navigation device 1 is mounted turns right or left at the nearest intersection. There are several possible methods for predicting a left or right turn. In the first method, when the travel route to the destination is set, the controller 20 predicts whether to turn right or left at the nearest intersection based on the set travel route.

  In the second method, the controller 20 predicts a right / left turn based on the presence / absence of an instruction to the winker (direction indicator) of the vehicle and the current position of the vehicle. Specifically, when the driver gives a direction instruction to the right or left while the vehicle is traveling on a one-lane road, the controller 20 predicts that the vehicle turns right or left in the direction in which the direction instruction is issued. To do. In the third method, the controller 20 predicts a left / right turn based on the map information and the current position of the vehicle. Specifically, when the vehicle is traveling on a right turn lane or a left turn lane on a certain road, the controller 20 predicts that the vehicle turns right or left. In addition, said 1st-3rd method can be used in arbitrary combinations.

  When it is not predicted that a right / left turn will be performed (step S12: No), the controller 20 repeats step S11. On the other hand, when it is predicted that a right / left turn will be performed (step S12: Yes), the controller 20 performs a trajectory prediction process (step S13).

  The trajectory prediction process is a process of predicting a trajectory when the vehicle travels left and right at an intersection, and specifically, a process of calculating a relaxation curve indicating the trajectory of the vehicle. FIG. 3 shows a flowchart of the trajectory prediction process. First, the controller 20 determines whether or not the vehicle has reached a predetermined distance from the nearest intersection (step S21).

  When the vehicle reaches a predetermined distance from the intersection (step S21: Yes), the controller 20 acquires the traveling speed of the vehicle (step S22). In this case, basically, the controller 20 acquires the current traveling speed of the vehicle, and uses the acquired speed on the assumption that the traveling speed is within the intersection. That is, it is assumed that the vehicle travels and passes through the intersection while maintaining its traveling speed.

  However, the controller 20 may acquire the change rate of the traveling speed of the vehicle up to that time, and may predict the traveling speed in the intersection in consideration of the acquired change rate. Specifically, the controller 20 accumulates travel speed data before entering the intersection, and calculates the change rate of the travel speed. Then, the traveling speed in the intersection is predicted by adding the rate of change to the traveling speed acquired in step S22. Usually, since a vehicle decelerates as it approaches an intersection, a change in travel speed is a deceleration. Therefore, when considering the change rate of the traveling speed, the controller 20 usually predicts a traveling speed within the intersection that is lower than the traveling speed acquired in step S22.

  When the traveling speed in the intersection is predicted, the controller 20 next sets the start point and the end point of the predicted track (step S23). The predicted trajectory is a trajectory predicted to be drawn when the vehicle makes a right or left turn inside an intersection. Specifically, the controller 20 sets the start point and end point of the predicted trajectory based on the current position of the vehicle, map information (intersection shape), and travel speed.

  Specifically, the controller 20 first determines the initial start point of the predicted trajectory based on the current position of the vehicle and road information (road direction, number of lanes, road width (width), etc.) of the road on which the vehicle is traveling. Set the position. For example, the controller 20 sets the point where the vehicle enters the intersection on the running road as the initial position of the start point of the predicted trajectory. The range of the intersection can be defined based on the center position (coordinates) of the intersection and the width of the road that intersects the running road, so determine the point where the currently running road intersects the intersection range. This can be the starting point.

  Next, the controller 20 sets the initial position of the end point of the predicted trajectory based on the road information (the road direction, the number of lanes, the road width, etc.) of the road that has left the intersection. For example, the controller 20 sets the point at which the vehicle exits the intersection on the road ahead of which the vehicle turns right or left as the initial position of the end point of the predicted trajectory. As mentioned above, the range of the intersection can be defined based on the center position (coordinates) of the intersection and the width of the road that intersects with the road that is running, so the road to the right and left turns into the range of the intersection. A point of intersection can be determined and this can be the end point.

  FIG. 4A shows a setting example of the start point and the end point of the predicted trajectory when the vehicle is traveling at the standard speed. As shown by the own vehicle position mark 101, the vehicle enters the intersection from the lower side in the figure, and turns right at the intersection. A point 103 where the vehicle enters the intersection is set as the initial position of the start point, and a point 104 where the vehicle after the right turn leaves the intersection is set as the initial position of the end point.

  The start point and the end point of the predicted trajectory are set to positions corresponding to the case where the vehicle travels the intersection at a standard speed. In the above example, the start point and end point of the predicted trajectory are set on the outer periphery of the range of the intersection, but instead, may be set at positions separated from the intersection by a predetermined distance. Specifically, the start point and the end point of the predicted trajectory may be set at points that are a predetermined distance away from the intersection node in the map information. Further, the start point and end point position of the predicted trajectory may be stored in advance in the map information.

  When the initial positions of the start point and the end point of the predicted trajectory are thus set, the controller 20 next sets the initial position of the start point and the end point along the direction of each road according to the traveling speed of the vehicle predicted in step S22. To correct. Specifically, the controller 20 moves the start point to the near side of the intersection and the end point to the far side of the intersection as the traveling speed increases. This is because, as the traveling speed increases, the small turning of the vehicle becomes ineffective and the vehicle cannot pass through the intersection unless it is a large turning track. In this case, as a driving operation of the driver, it is necessary to start turning the steering wheel from the near side and finish returning the steering wheel at a further distance. FIG. 4B shows an example in which the start point and end point of the predicted trajectory are corrected when the vehicle speed exceeds the standard speed. In this example, since the traveling speed of the vehicle predicted in step S22 is faster than the standard speed, the start point 103 is moved to the near side as shown by the arrow 107, and the end point 104 is far from the intersection as shown by the arrow 108. Has been moved to the side.

  Thus, the start point and the end point of the predicted trajectory are appropriately corrected according to the traveling speed of the vehicle. Note that the initial position and the correction amount of the start point and end point of the predicted trajectory are based on the experimental results obtained by examining the actual behavior of the vehicle, and the actual start position and return end position of the steering wheel by the driver. It is good to set appropriately so that it may approach.

  Note that instead of or in addition to the correction based on the traveling speed as described above, the start point and the end point of the predicted trajectory may be corrected based on the actual driving tendency of the driver. Specifically, based on the driver's past travel history data, the driver's tendency to turn left and right, specifically, the position where the steering wheel started to be turned and the position where the steering wheel has been returned (how many meters at the intersection) The start point and the end point of the predicted trajectory may be corrected based on the result. As a result, it is possible to obtain a predicted trajectory suitable for a driver having various driving tendencies, such as a driver who starts turning a steering wheel early when turning right or left at an intersection, or a driver who slowly starts turning a steering wheel.

  Next, the controller 20 calculates a clothoid curve passing through the start point and the end point set in step S23 (step S24). The clothoid curve is an example of a relaxation curve, and indicates a trajectory that the vehicle travels when the steering wheel is rotated at a constant angular velocity. Normally, when the driver performs a smooth steering operation on a curve, the track of the vehicle includes a clothoid curve. That is, here, the controller 20 predicts the trajectory of the vehicle when the driver performs a natural driving operation.

  Specifically, the clothoid curve here includes a trajectory drawn by the vehicle when the driver turns the steering wheel and a trajectory drawn by the vehicle when the driver returns the steering wheel. For example, if the angle of the intersection is 90 degrees, it is typically a clothoid curve when the steering wheel is turned at a constant speed until the direction of the vehicle rotates 45 degrees, and thereafter the steering wheel is returned at a constant speed. It becomes a clothoid curve when going. Further, assuming that the traveling speed of the vehicle is constant, the clothoid curve when the steering wheel is turned and the clothoid curve when the steering wheel is returned have a line-symmetric shape. That is, by assuming that the traveling speed of the vehicle in the intersection is constant, a clothoid curve passing through the start point and end point of the set predicted trajectory can be uniquely calculated.

  In addition, at the intersection where the right / left turn angle is an acute angle, the turning angle of the handle is constant between the clothoid curve when turning the handle at a constant speed and the clothoid curve when turning the handle at a constant speed. You may insert the circular arc used as a track | orbit when it maintains at an angle. In this case, the length of the arc to be inserted may be appropriately set according to the shape of the intersection.

The basic formula of the clothoid curve is given as follows.
R × L = A ² (1)
Here, “L” indicates a curve length from the start point (clothoid start point) to an arbitrary position P in the intersection, “R” indicates a radius of curvature at the arbitrary position P, and “A” indicates a clothoid parameter (constant). If a clothoid curve is uniquely determined, the corresponding clothoid parameter A is uniquely determined. In step S23, the controller 20 draws a clothoid curve passing through the start point and end point of the predicted trajectory, and obtains the clothoid parameter A. Specifically, a clothoid curve passing through the start point and end point of the predicted trajectory is drawn while changing the clothoid parameter A, and the clothoid parameter A of the obtained clothoid curve is output. In this way, the predicted trajectory 102 illustrated in FIGS. 4A and 4B is obtained. When the clothoid curve is calculated, the process returns to the main routine of FIG.

  Next, the controller 20 performs a travel risk determination process (step S14). 5 and 6 are flowcharts of the travel risk determination process. In FIG. 5, the controller 20 first determines whether or not there is an oncoming lane in the intersection based on road information near the intersection (step S31). When there is no oncoming lane (step S31: No), the process proceeds to step S38 described later.

  On the other hand, when there is an oncoming lane (step S31: Yes), the controller 20 detects a determination position P1 that is a position where the predicted track intersects the oncoming lane (step S32). FIG. 7A shows an example of the determination position P1. In the example of FIG. 7A, the controller 20 detects a determination position P1 where the predicted track 102 intersects the oncoming lane 110.

Next, the controller 20 calculates the lateral acceleration Ga1 generated in the vehicle at the determination position P1 when the current traveling speed is maintained (step S33). The lateral acceleration Ga1 generated in the vehicle at the determination position P1 on the predicted trajectory 102 is obtained by the following equation.
Ga1 = (current speed) ² × A ² / L (2)
Here, “A” is the clothoid parameter obtained in step S24 of the trajectory prediction process, and “L” is the travel distance from the start point on the predicted trajectory 102 to the determination position P1. FIG. 8 shows the acceleration at the determination position P1. As shown in FIG. 8, the lateral acceleration Ga1 is a vector in a direction perpendicular to the traveling direction of the vehicle at the determination position P1.

  Further, the controller 20 calculates a negative acceleration Gb1 generated in the vehicle when the vehicle suddenly stops at the determination position P1 (step S34). Specifically, the controller 20 stops the vehicle at the determination position P1 based on the traveling speed of the vehicle, the distance from the start point on the predicted track 102 to the determination position P1, the braking characteristics of the vehicle, and the like (that is, the speed is reduced). The negative acceleration Gb1 necessary for decelerating to 0) is obtained. The negative acceleration may be obtained by preparing a table or the like previously calculated according to the traveling speed of the vehicle, the distance to the determination position P1, the weight of the vehicle, and the like. . As shown in FIG. 8, the negative acceleration Gb1 is a vector directed in the direction opposite to the traveling direction of the vehicle at the determination position P1.

  Then, the controller 20 calculates a combined acceleration Gc1 of the lateral acceleration Ga1 and the negative acceleration Gb1 (step S35). Specifically, as shown in FIG. 8, the resultant acceleration Gc1 is calculated by obtaining a resultant vector of the lateral acceleration Ga1 and the negative acceleration Gb1 at the determination position P1. Here, the combined acceleration Gc1 is calculated as an index for comprehensive evaluation of the risk due to the lateral acceleration Ga1 and the risk due to the negative acceleration Gb1. By using the lateral acceleration Ga1, it is possible to determine the risk from the viewpoint of whether the vehicle can travel stably in the intersection. Further, by using the negative acceleration Gb1, it is possible to determine a risk from the viewpoint of whether the vehicle can be safely stopped when an oncoming vehicle comes within an intersection.

  Next, the controller 20 determines whether or not the calculated combined acceleration Gc1 is larger than a predetermined reference value (step S36). If the combined acceleration Gc1 is less than the reference value (step S36: No), the process proceeds to step S38. On the other hand, when the combined acceleration Gc1 is larger than the reference value (step S36: Yes), the controller 20 determines that there is a running risk (step S37). Then, the process returns to the main routine of FIG. This reference value is determined in advance based on information obtained from an experiment using a vehicle, a situation of an accident that actually occurred, or the like. Note that the reference value may be changed according to the road surface condition, the road gradient, the vehicle type of the host vehicle (small car / large car), and the like.

  If it is determined in step S31 that there is no oncoming lane, and if it is determined in step S36 that the resultant acceleration Gc1 is less than the reference value, the process proceeds to step S38 shown in FIG. In step S38, the controller 20 determines whether or not the predicted trajectory passes a pedestrian crossing near the intersection based on road information near the intersection. When the vehicle does not pass the pedestrian crossing (step S38: No), the controller 20 determines that there is no travel risk (step S44), and the process returns to the main routine of FIG.

  On the other hand, when the predicted trajectory passes the pedestrian crossing (step S38: Yes), the controller 20 detects a determination position P2 that is a position where the predicted trajectory reaches the pedestrian crossing (step S39). FIG. 7B shows an example of the determination position P2. In the example of FIG. 7B, the controller 20 detects a determination position P2 where the predicted trajectory 102 intersects the pedestrian crossing 111. In this embodiment, the position where the predicted trajectory intersects the oncoming lane and the pedestrian crossing is set as the determination position as a position where the possibility of contact with another moving body is relatively high in the vicinity of the intersection, but the position is not limited to this. Alternatively, a two-way roadway that has a relatively high possibility of coming into contact with another moving body may be used as the target of the determination position.

  Next, the controller 20 calculates the lateral acceleration Ga2 generated in the vehicle at the determination position P2 when the current traveling speed is maintained (step S40). Specifically, the controller 20 obtains the lateral acceleration Ga2 generated in the vehicle at the determination position P2 on the predicted trajectory 102 by the above-described equation (2) in the same manner as the lateral acceleration Ga1.

  Further, the controller 20 calculates a negative acceleration Gb2 generated in the vehicle when the vehicle suddenly stops at the determination position P2 (step S41). Specifically, similarly to the negative acceleration Gb1 described above, the controller 20 determines the position at the determination position P2 based on the traveling speed of the vehicle, the distance from the start point on the predicted track 102 to the determination position P2, the braking characteristics of the vehicle, and the like. A negative acceleration Gb2 necessary for stopping the vehicle is obtained.

  Then, the controller 20 calculates the combined acceleration Gc2 of the lateral acceleration Ga2 and the negative acceleration Gb2 similarly to the above-described combined acceleration Gc1 (step S42). Here, the combined acceleration Gc2 is calculated as an index for comprehensive evaluation of the risk due to the lateral acceleration Ga2 and the risk due to the negative acceleration Gb2. By using the lateral acceleration Ga2, it is possible to determine the risk from the viewpoint of whether the vehicle can travel stably in the intersection. Further, by using the negative acceleration Gb2, it is possible to determine a risk from the viewpoint of whether the vehicle can be safely stopped when a pedestrian or the like is on the pedestrian crossing.

  Next, the controller 20 determines whether or not the calculated combined acceleration Gc2 is larger than a predetermined reference value (step S43). When the combined acceleration Gc2 is less than the reference value (step S43: No), the controller 20 determines that there is no travel risk (step S44). On the other hand, when the combined acceleration Gc1 is larger than the reference value (step S43: Yes), the process proceeds to step S37, and the controller 20 determines that there is a running risk. Then, the process returns to the main routine of FIG.

  When it is determined that there is a travel risk by the travel risk determination process, the controller 20 outputs a warning for notifying the driver of the danger (step S15). This warning is made by sound, light, vibration, or a combination thereof. Then, the warning process ends.

  As described above, according to the warning process of this embodiment, a trajectory when a vehicle turns right and left at an intersection at a constant speed is predicted, and a travel risk when traveling on the trajectory is determined. Further, if it is determined that there is a running risk, a warning is given. Therefore, it is possible to appropriately notify the driver of the risk when the vehicle travels the intersection.

[Modification]
Hereinafter, various modifications of the above embodiment will be described. Note that the following modifications can be applied in appropriate combination.

(Modification 1)
In the above embodiment, the case where the vehicle turns right at the intersection has been described as an example, but the present invention can also be applied to the case where the vehicle turns left at the intersection. Further, when the intersection has a complicated shape such as a three-way road or a five-way road, the present invention can be similarly applied to a case where the vehicle turns right or left obliquely forward or backward.

(Modification 2)
The above embodiment is described on the assumption that the lane on which the vehicle runs on the right turn destination road, but there are multiple lanes on the road after the right turn, and it is possible to drive any lane In such a case, the controller 20 may calculate the predicted trajectory by setting the end point of the predicted trajectory for each lane that can travel, and may perform risk determination for each predicted trajectory. In this case, the controller 20 may issue a warning when there is even one predicted trajectory determined as having a running risk. Alternatively, the risk determination may be performed on the predicted trajectory that is the smallest of the predicted trajectories of each lane, and a warning may be issued according to the determination result.

  Moreover, although there are a plurality of lanes on the road after turning left or right, based on surrounding traffic information using road-to-vehicle communication, vehicle-to-vehicle communication, etc., or obstacle detection by the obstacle detection unit 32 using a camera, Lidar, etc. If it is found that an obstacle exists on a specific lane, the lane may be excluded from the calculation target of the predicted trajectory. For example, as shown in the example of FIG. 9, there are two lanes 121 and 122 on the road to the right turn, but there is an obstacle when the lane 121 has an obstacle 120 and cannot travel. It is only necessary to set the end point for only the lane 122 not to be calculated, calculate the predicted trajectory, and determine the driving risk. Obstacles in this case include road works and the like in addition to other vehicles and moving objects such as pedestrians.

  In addition, when there are a plurality of lanes that do not have obstacles, as described above, an end point is set for each lane, a predicted trajectory is calculated, and risk determination is performed for each predicted trajectory. In this case, the controller 20 may issue a warning when there is even one predicted trajectory determined as having a running risk. Alternatively, the risk determination may be performed on the predicted trajectory that is the smallest of the predicted trajectories of each lane, and a warning may be issued according to the determination result.

(Modification 3)
In the above embodiment, the combined acceleration Gc1 or Gc2 of the lateral acceleration Ga1 or Ga2 and the negative acceleration Gb1 or Gb2 is calculated in steps S35 and S42 of the driving risk determination process, and this is compared with the reference value to calculate the driving risk. Is judged. Instead, the lateral acceleration and the negative acceleration may be compared with corresponding reference values. In that case, if either one of the lateral acceleration and the negative acceleration is larger than the reference value, it may be determined that there is a running risk.

  Further, in steps S34 and S41 of the travel risk determination process, the negative acceleration until the vehicle stops (that is, the travel speed becomes 0) is calculated, but instead, it does not cause a major accident. The negative acceleration when decelerating to the speed may be calculated. In this case, the speed of the deceleration target for the oncoming vehicle and the speed of the deceleration target for the pedestrian may be set individually. For example, a negative acceleration when decelerating to a speed close to a stop for a pedestrian may be obtained, and a negative acceleration when decelerating to a slow speed may be obtained for an oncoming vehicle.

(Modification 4)
In the above embodiment, regardless of whether or not there is actually an oncoming vehicle or a pedestrian on the pedestrian crossing, the driving risk is determined at the determination position P1 based on the oncoming lane and the determination position P2 based on the pedestrian crossing. doing. Instead, based on the information on surrounding traffic using road-to-vehicle communication, vehicle-to-vehicle communication, and obstacle detection by the obstacle detection unit 32 using a camera, Lidar, etc. When the presence or absence of the body can be determined, the driving risk may be determined only when an oncoming vehicle or a pedestrian actually exists. That is, when it is determined that there is no moving body such as an oncoming vehicle or a pedestrian on the predicted trajectory obtained by the trajectory prediction process based on the surrounding traffic information and the obstacle detection process, the travel risk determination process and It is good also as not performing a warning.

  On the other hand, based on surrounding traffic information and obstacle detection, if it is detected that there is a moving body such as another vehicle or pedestrian in a place other than the oncoming lane or pedestrian crossing in or near the intersection, The controller 20 may set the position of the detected other vehicle or pedestrian or the like as the determination position, and determine the running risk at the determination position. For example, as shown in FIG. 10, when it is detected that the pedestrian 105 exists on a road ahead of the right turn of the vehicle and ahead of the pedestrian crossing, the controller 20 detects the pedestrian 105. Is set as the determination position Px. Then, similarly to the above-described travel risk determination process, the lateral risk and the negative acceleration at the determination position Px may be calculated to determine the travel risk, and a necessary warning may be given. In addition, when other vehicles or pedestrians are actually detected based on the surrounding traffic information and obstacle detection, and it is determined that there is a driving risk based on the driving risk determination, in addition to the warning output Thus, a process of automatically braking and stopping the vehicle may be performed.

(Modification 5)
In the above trajectory prediction process, a clothoid curve is used as a relaxation curve indicating the vehicle trajectory in the intersection, but the application of the present invention is not limited to this. For example, a broth relaxation curve, a sine curve, a sine half wavelength The predicted trajectory may be obtained using other known relaxation curves such as a decreasing curve and a cubic curve.

  Further, the type and characteristics (parameters) of the relaxation curve used in the track prediction process may be changed based on the tendency of the driver's travel track. Even at intersections of the same shape, the trajectory drawn during actual travel often differs depending on the driver's habit and travel tendency. For example, (a) a driver who tends to bend at a relatively large turn, (b) a driver who tends to bend at a relatively small turn, (c) a person who enters the intersection at a relatively fast speed and tends to bend while bulging out in the second half. There are drivers with various driving tendencies, such as a driver and (d) a driver who tends to enter an intersection at a relatively slow speed, change direction early and exit the intersection linearly. Therefore, by preparing in advance a relaxation curve and characteristics suitable for the various traveling trends as described above, by changing the type and characteristics of the relaxation curve used in the trajectory prediction process according to the traveling tendency of the driving vehicle, A predicted trajectory that matches the actual driving tendency of the driver can be generated.

  As an example of an actual method, the driving tendency options as shown in the above (a) to (d) are presented to the driver, and the driving tendency is selected so that it matches the driving tendency. The trajectory prediction process may be performed using at least one of a relaxation curve and a characteristic (parameter) prepared in advance. In another example, instead of letting the driver himself select a driving tendency as described above, the driving tendency when the driver makes a right or left turn at the intersection with reference to the actual driving history data of the driver. It is good also as changing the relaxation curve and characteristic to be used based on the run tendency analyzed. In this case, by accumulating and analyzing the driving history data at more intersections, the driving tendency of the driver in turning right and left is extracted, and the types and characteristics of the relaxation curves are changed based on the obtained driving tendency. It is desirable. As a result, it is possible to obtain a predicted trajectory adapted to the driving tendency of the driver not only at the intersection where the driver actually traveled in the past but also at the intersection where the driver travels for the first time.

(Modification 6)
In the above embodiment, the position where the predicted trajectory crosses the oncoming lane or pedestrian crossing is used as the determination position for determining the running risk. In the modified example 4, the position of another moving body detected based on the surrounding traffic information and the obstacle detection Is the determination position. In this case, the determination position may be corrected according to the driver information, specifically the driving skill level. For a driver whose driving skill level is determined to be below a certain level, safety can be improved by performing correction that moves the determination position to the near side. The driving skill level of the driver can be estimated by analyzing the past driving history data of the driver. Further, the driver himself may evaluate and set his / her driving skill level. Further, as the driver information, the driver's attributes (age, gender, driving history, etc.), the driving tendency of the driver, and the like may be used as indirectly indicating the driving skill level. Further, instead of determining the correction amount for the determination position based on the driver information, the correction amount for the determination position may be set by the driver himself. For example, a driver who is not very confident in driving technology may be able to set the correction of the determination position a predetermined distance (for example, several meters) before the normal travel risk determination position. Also, before and after entering the intersection, when an approach of an emergency vehicle is detected based on road-to-vehicle communication, vehicle-to-vehicle communication, siren sound, or the like, correction for moving the determination position to the near side may be performed. Good.

  Moreover, you may make it correct | amend the reference value used for determination of driving | running risk instead of correcting the determination position which determines driving | running risk as mentioned above. Specifically, the reference value (see steps S36 and 43) used in the travel risk determination process is corrected according to the driver information. For example, for a driver whose driving skill level is estimated to be below a certain level based on the driver information, the driving risk is determined using a reference value that is lower than a reference value that is normally used. Thereby, it is possible to easily output a warning to a driver having a low driving skill level.

(Modification 7)
In the above-described embodiment, it has been described that the navigation device 1 mounted on the vehicle performs the travel risk determination process at the time of turning right or left at the intersection, and performs a necessary warning. The system may be composed of an in-vehicle device such as the display unit 40 or the audio output unit 50 and an external device (such as a server). Specifically, the in-vehicle device transmits various types of information to the server via the network, and the server performs at least one of the trajectory prediction process and the travel risk determination process, and transmits the processing result in the server to the in-vehicle device. May be. In other words, the in-vehicle device and the external device may execute the driving risk determination process when turning right or left at the intersection in cooperation. Which of the series of processes each of the in-vehicle device and the external device executes may be set as appropriate. Further, the navigation device 1 may be provided in a vehicle or a mobile terminal.

1 Navigation device 22 CPU
32 Obstacle detection unit 101 Vehicle position mark 102 Predicted trajectory 103 Start point 104 End point P1, P2, Px determination position

Claims (7)

A determination device for determining a travel risk before a mobile object actually turns right or left at an intersection,
A prediction unit that predicts a travel path when the mobile body travels the intersection based on speed information regarding the moving speed of the mobile body, and intersection information including the shape of the intersection;
A detection unit for detecting other moving objects around the intersection;
A setting unit for setting a determination position on the travel path based on the other moving body;
A determination unit that determines the travel risk at the determination position based on the speed information and the travel track;
A determination apparatus comprising:   2. The determination according to claim 1, wherein when the other moving body is not detected by the detection unit, the setting unit does not set the determination position, and the determination unit does not determine the travel risk. apparatus.   The determination apparatus according to claim 1, wherein the other moving body includes a moving body other than a moving body on an oncoming lane and a pedestrian crossing.   The detection unit detects the other moving body based on at least one of the surrounding traffic information of the intersection acquired from the outside and the detection result by the obstacle detection device mounted on the moving body. The determination apparatus according to any one of claims 1 to 3. A determination method that is executed by a determination device that determines a travel risk before the mobile body actually makes a right or left turn at an intersection,
A prediction step of predicting a travel path when the mobile body travels the intersection based on speed information related to the moving speed of the mobile body, intersection information including the shape of the intersection;
A detection step of detecting other moving objects around the intersection;
A setting step of setting a determination position on the traveling track based on the other moving body;
A determination step of determining the travel risk at the determination position based on the speed information and the travel track;
A determination method comprising: A program comprising a computer and executed by a determination device for determining a travel risk before the mobile object actually travels left or right at an intersection,
A prediction unit that predicts a travel path when the mobile body travels the intersection based on speed information related to the moving speed of the mobile body, and intersection information including the shape of the intersection;
A detection unit for detecting other moving objects around the intersection;
A setting unit for setting a determination position on the traveling track based on the other moving body;
A determination unit that determines the travel risk at the determination position based on the speed information and the travel track;
A program for causing the computer to function as:   A storage medium storing the program according to claim 6.