JP7579683B2 - Driving support method and driving support device - Google Patents

Description

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

A method for setting a turning path within an intersection when a vehicle turns right or left at the intersection has been known for some time (see Patent Document 1). The invention described in Patent Document 1 combines map data with road data acquired by LiDAR at least once in the past to generate accurate road and lane information (high-precision map), and sets a turning path within the intersection based on the high-precision map.

JP 2016-75905 A

However, in order for the invention disclosed in Patent Document 1 to set a turning path within an intersection when the vehicle turns right or left at the intersection, the driver must have driven through the intersection at least once in the past and generated a high-precision map including lane information in advance. Therefore, with the conventional technology, there was a problem in that a turning path could not be set when turning right or left at an intersection where high-precision map data has not been generated, such as a newly constructed intersection.

The present invention was made in consideration of the above problems, and its purpose is to provide a driving support method and a driving support device that can set a turning path within an intersection when a vehicle turns right or left at an intersection without using a high-precision map.

A driving support method according to one aspect of the present invention extracts an intersection where a lane on which a vehicle travels intersects with another lane, and where a driving route for turning from the vehicle travelling lane to the other lane is set. A first extension line that passes through the position of the other vehicle moving on the other lane from the opposite direction to the direction of turning of the vehicle to the turning direction at the extracted intersection and extends in the moving direction of the other vehicle or in the opposite direction, and a first straight driving direction line that passes through the position of the vehicle and extends in the straight driving direction of the vehicle. An outermost boundary line that is an arc-shaped curve with a radius equal to the minimum turning radius of the vehicle and is tangent to the first extension line and the first straight driving direction line, and an innermost boundary line that is an arc-shaped curve with a radius larger than the minimum turning radius are set. A turning route is set in a route setting area that is an area surrounded by the first extension line, the first straight driving direction line, the outermost boundary line, and the innermost boundary line, and each control unit that controls the steering, accelerator, and brake of the vehicle is controlled so that the vehicle travels on the turning route.

According to the present invention, when a vehicle turns right or left at an intersection, a driving route can be set without using a high-precision map.

FIG. 1 is a block diagram showing the configuration of a driving assistance device according to the first embodiment. FIG. 2 is a diagram illustrating a process in which the driving assistance device according to the first embodiment sets a route setting area. FIG. 3 is a flowchart showing a process of controlling the vehicle in accordance with a turning route set by the driving assistance device according to the first embodiment. FIG. 4 is a block diagram showing the configuration of a driving assistance device according to the second embodiment. FIG. 5 is a diagram illustrating a process in which the driving support device according to the second embodiment estimates the center position of an intersection. FIG. 6 is a diagram illustrating a process in which the driving assistance device according to the second embodiment corrects the outermost boundary line. FIG. 7 is a flowchart showing a process for controlling a vehicle in accordance with a turning route set by a driving assistance device according to the second embodiment. FIG. 8 is a block diagram showing the configuration of a driving assistance device according to the third embodiment. FIG. 9 is a diagram illustrating a process in which the driving support device according to the third embodiment estimates the center position of an intersection. FIG. 10 is a diagram illustrating a process in which the driving support device according to the third embodiment estimates the center position of an intersection. FIG. 11 is a diagram illustrating a process of setting a detection range for another vehicle by a driving assistance device according to the third embodiment. FIG. 12 is a flowchart showing a process for controlling a vehicle in accordance with a turning route set by a driving assistance device according to the third embodiment.

The embodiment will be described with reference to the drawings. In the description of the drawings, the same parts are given the same reference numerals and the description will be omitted.

First Embodiment
[Configuration of the driving support device]
The overall configuration of a driving support device according to this embodiment will be described with reference to Fig. 1. The driving support device is a device that sets a turning path for the host vehicle at an intersection and supports the host vehicle in traveling along the set turning path.

The driving support device 100 is composed of a controller. The driving support device 100 detects other vehicles ahead of the vehicle using a camera 200 and a radar 300 mounted on the vehicle, and sets a turning route at an intersection where the vehicle turns right or left based on the position and moving direction of the other vehicles. In FIG. 1, the camera 200 and the radar 300 are illustrated as devices for acquiring external information, but LiDAR may also be used. The driving support device 100 sets a driving route from the current position of the vehicle to the destination using map data that is not a high-precision map. The map data may be stored in the storage unit 400, or may be appropriately received via Internet communication from an external server including a cloud server.

The controller is a general-purpose microcomputer equipped with a CPU (Central Processing Unit), memory, and input/output units. A computer program for functioning as the driving assistance device 100 is installed in the microcomputer. By executing the computer program, the microcomputer functions as multiple information processing circuits equipped in the driving assistance device 100. Note that in this embodiment, an example is shown in which multiple information processing circuits equipped in the driving assistance device 100 are realized by software, but it is of course possible to configure the information processing circuits by providing dedicated hardware for executing each of the information processes described below. Furthermore, the multiple information processing circuits may be configured by individual hardware.

The driving support device 100 includes multiple information processing circuits, including a driving route setting unit 110, an intersection extraction unit 120, a vehicle position detection unit 130, a moving object measurement unit 140, a turning route setting unit 150, and a driving support unit 160.

The driving route setting unit 110 reads the map data stored in the memory unit 400 and sets a driving route from the current position of the vehicle to the input destination. The driving route setting unit 110 may search for multiple driving routes to the destination. The driving routes include a driving route with a short driving distance, a driving route that avoids traffic jams and takes a short driving time to the destination, and a driving route that mainly travels on main roads, and the like. Based on the input user's preferences, the driving route setting unit 110 sets the optimal driving route from the multiple driving routes searched. The driving route setting unit 110 can search for a driving route by using a car navigation function. Note that the map data stored in the memory unit 400 is map data that includes information on a road basis, and does not need to include information on a lane basis (lane information) like a high-precision map. In other words, the map data stored in the memory unit 400 may be a map that includes information for setting a road-based route from the current position to the destination, like a map for car navigation, and is also referred to as simple map data below.

The driving route setting unit 110 determines the driving lane of the vehicle on the driving route excluding the set intersection. For example, if the driving route of the vehicle includes an intersection where the vehicle turns right, and the driving route to the intersection where the vehicle turns right has two or more lanes on each side, the driving route is set so that the vehicle will travel in the rightmost lane before the distance from the intersection to the vehicle becomes less than a specified distance. If the driving route connecting to the intersection where the vehicle turns right has two or more right-turn lanes, the driving route is set to one of the right-turn lanes. The same applies to intersections where the vehicle turns left, and the driving route is set so that the vehicle will travel in the leftmost lane before the distance from the intersection to the vehicle becomes less than a specified distance. Alternatively, if the driving route connecting to the intersection where the vehicle turns left has two or more left-turn lanes, the driving route is set to one of the left-turn lanes.

The intersection extraction unit 120 extracts intersections on the driving route at which the host vehicle will turn right or left, and obtains the positions of the intersections at which the host vehicle will turn right or left. Specifically, the intersection extraction unit 120 extracts information about intersections registered in the map data, and identifies the positions of the intersections at which the host vehicle will turn right or left.

The vehicle position detection unit 130 detects the position of the vehicle. Specifically, the vehicle position detection unit 130 detects the position of the vehicle using a GPS function. The vehicle position detection unit 130 can more accurately identify the position of the vehicle by correcting GPS errors using a map matching function. The vehicle position detection unit 130 calculates the distance from the identified vehicle position to the next intersection where the vehicle will turn right or left from the driving route. This allows the vehicle position detection unit 130 to determine whether the vehicle is approaching an intersection where the vehicle will turn right or left. As a specific method for determining whether the vehicle is approaching an intersection where the vehicle will turn right or left, the vehicle can determine this based on the driving time until the vehicle enters the intersection. For example, if the driving time to the intersection is less than 15 seconds, the vehicle is determined to be approaching the intersection. The determination of whether the vehicle is approaching an intersection where the vehicle will turn right or left may be determined based on the distance from the vehicle to the intersection.

The moving object measurement unit 140 acquires information ahead of the host vehicle from the camera 200 and radar 300, and by analyzing the acquired information, detects other vehicles ahead of the host vehicle and measures the position and movement direction of the other vehicles. The moving object measurement unit 140 includes an object detection unit 141, an object position measurement unit 142, an object movement direction measurement unit 143, and a host vehicle behavior measurement unit 144. Note that, in this embodiment, a method of detecting other vehicles using the camera 200 and radar 300 is described, but the method of detecting other vehicles is not limited to this. For example, other vehicles may be detected using a stereo camera or a LiDAR.

The object detection unit 141 detects other vehicles from the captured image of the area in front of the vehicle captured by the camera 200. Specifically, the object detection unit 141 detects other vehicles included in the captured image by using an image recognition function. The image recognition function is a function that extracts the features of each object included in the captured image and identifies the object from the extracted features of each object. The object detection unit 141 determines whether each object included in the captured image has the features of a vehicle, and determines whether each object is another vehicle.

The object position measurement unit 142 measures the relative position of other vehicles with respect to the host vehicle in real space at each time. Specifically, the object position measurement unit 142 acquires the three-dimensional relative position of each object measured by the radar 300 with respect to the host vehicle, and extracts the three-dimensional relative position of other vehicles detected by the object detection unit 141 from the acquired three-dimensional relative positions of each object. This allows the object position measurement unit 142 to measure the three-dimensional relative position of other vehicles with respect to the host vehicle in real space.

As described above, the sensor fusion of the camera 200 and the radar 300 makes it possible to detect other vehicles and measure their relative positions in real space with respect to the host vehicle. In this embodiment, the radar 300 is used to measure the three-dimensional relative position of other vehicles, but the method of measuring the three-dimensional relative position of other vehicles is not limited to this. For example, by using a stereo camera as the camera 200, it is possible to measure the three-dimensional relative position of other vehicles with respect to the host vehicle without using the radar 300.

The object movement direction measurement unit 143 detects the movement direction of the other vehicle based on the relative position in real space of the other vehicle with respect to the host vehicle at each time measured by the object position measurement unit 142 and the amount of movement of the host vehicle measured by the host vehicle behavior measurement unit 144.

The host vehicle behavior measurement unit 144 identifies the host vehicle's position in real space at each time and measures the host vehicle's movement amount from the change in the host vehicle's position in real space. Specifically, the host vehicle behavior measurement unit 144 identifies the host vehicle's position in real space at each time by acquiring the coordinates of the host vehicle using a GPS function. Note that the host vehicle behavior measurement unit 144 may calculate the host vehicle's position using the host vehicle's speed pulse and the host vehicle's yaw rate sensor in addition to the host vehicle's coordinates acquired using the GPS function. The host vehicle behavior measurement unit 144 can measure the movement direction and movement amount of the host vehicle from the change in the acquired host vehicle's position in real space at each time.

The following is a detailed explanation of the process in which the object movement direction measurement unit 143 detects the movement direction of another vehicle from the relative position in real space of the other vehicle relative to the host vehicle at each time and the amount of movement of the host vehicle.

The object movement direction measurement unit 143 detects the movement direction of the other vehicle by correcting the three-dimensional relative position of the other vehicle in real space with respect to the subject vehicle measured by the object position measurement unit 142 to a position in real space (absolute position) based on the amount of movement of the subject vehicle, and tracking the three-dimensional absolute position of the other vehicle. More specifically, it is assumed that the three-dimensional relative position of the other vehicle measured at time T1 is (X1, Y1, Z1), and the three-dimensional relative position of the other vehicle measured at time T2 is (X2, Y2, Z2). Then, if the distance traveled by the host vehicle between time T1 and time T2 is (Xc, Yc, Zc), the position of the other vehicle in real space corrected by the distance traveled by the host vehicle can be calculated as (X2-(X1-Xc), Y2-(Y1-Yc), Z2-(Z1-Zc). This allows the object movement direction measurement unit 143 to detect the movement direction of the other vehicle. Here, X, Y, and Z are coordinates with the position of the camera 200 as the reference position (origin), X indicates the left-right direction and is positive to the right of the reference position, Y indicates the up-down direction and is positive above the reference position, and Z is the front-rear direction and is positive forward of the reference position. Note that the above-mentioned method of calculating the movement direction of the other vehicle can detect the movement vector of the other vehicle in addition to the movement direction of the other vehicle.

The turning path setting unit 150 sets a turning path for the host vehicle at an intersection. Specifically, when the host vehicle position detection unit 130 determines that the host vehicle is approaching an intersection where the host vehicle will turn right or left, the turning path setting unit 150 sets a route setting area that is an area at the intersection where the host vehicle can travel, and sets a turning path for the host vehicle in the set route setting area.

2, the process of the turning path setting unit 150 setting the path setting area 8 will be specifically described. The path setting area 8 is an area (hatched portion) surrounded by the first extension line 3, the first straight direction line 4, the outermost boundary line 6, and the innermost boundary line. When the vehicle is approaching an intersection where the vehicle is to turn right or left, the turning path setting unit 150 first calculates the first extension line 3 and the first straight direction line 4. Next, the turning path setting unit 150 sets the outermost boundary line 6 and the innermost boundary line 7 that are tangent to the first extension line 3 and the first straight direction line 4. The turning path setting unit 150 sets the area (hatched portion) surrounded by the first extension line 3, the first straight direction line 4, the outermost boundary line 6, and the innermost boundary line 7 as the path setting area 8.

First, the process of calculating the first extension line 3 and the first straight direction line 4 by the turning path setting unit 150 will be described. The first extension line 3 is an extension line that passes through the position of the other vehicle 2A moving in the other lane at the intersection from the opposite direction of the turning direction of the host vehicle 1 toward the turning direction, and extends in the moving direction of the other vehicle 2A or in the opposite direction, and the first straight direction line 4 is an extension line that extends in the straight direction of the host vehicle 1. In Fig. 2, the turning direction of the host vehicle 1 is the lower right direction, and the other vehicle 2A moves from the upper left direction, which is the opposite direction of the turning direction of the host vehicle, toward the lower right direction, which is the turning direction of the host vehicle.

When the vehicle position detection unit 130 determines that the vehicle 1 is approaching an intersection where the vehicle 1 turns right or left, the turning path setting unit 150 obtains the turning direction of the vehicle from the travel path setting unit 110 and obtains the moving direction of the other vehicle 2A from the object moving direction measurement unit 143. When multiple other vehicles (not shown) are detected, the turning path setting unit 150 extracts the moving direction of the other vehicle 2A moving from the opposite direction to the turning direction of the vehicle 1 toward the turning direction from among the moving directions of the multiple other vehicles obtained. The turning path setting unit 150 calculates a first extension line 3 that passes through the position of the other vehicle 2A and extends to the lower right, which is the moving direction of the other vehicle 2A. The turning path setting unit 150 obtains the moving direction of the vehicle 1 from the vehicle position detection unit 130 and calculates a first straight direction line 4 that extends in the straight direction of the vehicle 1.

Next, the process of setting the outermost boundary line 6 and the innermost boundary line 7 by the turning path setting unit 150 will be described. The outermost boundary line 6 is an arc-shaped curve with a radius equal to the minimum turning radius Rmin of the vehicle tangent to the first extension line 3 and the first straight line 4, and the innermost boundary line 7 is an arc-shaped curve with a radius Rmax larger than the minimum turning radius of the vehicle tangent to the first extension line 3 and the first straight line 4.

The turning path setting unit 150 generates an arc-shaped curve with a radius equal to the vehicle's minimum turning radius Rmin, and sets the outermost boundary line 6 where the generated curve is tangent to the first extension line 3 and the first straight line 4. The turning path setting unit 150 sets the innermost boundary line 7, which is an arc-shaped curve with a radius Rmax greater than the vehicle's minimum turning radius Rmin and tangent to the vehicle, the first extension line 3, and the first straight line 4.

The turning path setting unit 150 sets, as the innermost boundary line 7, a curve whose curvature change rate is equal to or less than a predetermined value, and whose direction when connecting to the first extension line 3 coincides with the direction of the first extension line 3. Specifically, the turning path setting unit 150 sets a curve whose curvature change rate is equal to or less than a predetermined value when an arc having a radius Rmax larger than the minimum turning radius Rmin of the vehicle connects to the vehicle 1 and the first extension line 3. The predetermined value is a curvature that allows the occupants of the vehicle to tolerate the lateral acceleration generated in the vehicle when the vehicle runs on the set curve. The turning path setting unit 150 sets the curvature so that the direction of the curve when connecting to the first extension line 3 coincides with the direction of the first extension line 3. The difference between the turning radius Rmin and the radius Rmax can be set arbitrarily in advance, and may be constant or variable depending on the road shape.

As described above, the turning path setting unit 150 sets a route setting area 8, which is an area surrounded by the first extension line 3, the first straight line 4, the outermost boundary line 6, and the innermost boundary line 7, and can set a turning path for the vehicle in the set route setting area 8. If the turning path setting unit 150 determines that an object detected by the object detection unit 141 is on the turning path, it searches for a turning path that avoids the object within the route setting area 8 and sets a turning path that avoids the object. Alternatively, it sets a turning path that stops the vehicle before the object's location.

Returning to FIG. 1, the driving support unit 160 controls the host vehicle to travel along the turning path set in the route setting area 8. Furthermore, if the turning path setting unit 150 is unable to set a turning path that avoids an object within the range of the route setting area, the driving support unit 160 controls the host vehicle to stop. Specifically, the driving support unit 160 controls each control unit that controls the steering, accelerator, and brake, such as an electric power steering unit, an engine control unit, and an ABS unit, to control the host vehicle.

[Driving support method]
Next, a method in which the driving support device shown in Fig. 1 sets a turning route in an intersection without using a high-precision map and controls the host vehicle to travel along the set turning route will be described with reference to Fig. 3. The operation of the driving support device shown in the flowchart of Fig. 3 is started when the destination of the host vehicle is set and the driving support function of the host vehicle is enabled, and ends when the host vehicle arrives at the destination or the driving support function of the host vehicle is disabled.

In step S10, the driving route setting unit 110 acquires the input destination, reads out the road-by-road simple map data stored in the memory unit 400, and sets a road-by-road driving route from the vehicle's current position to the input destination.

Proceeding to step S20, the vehicle position detection unit 130 detects the position of the vehicle and acquires the position of the intersection where the vehicle will turn right or left on the driving route acquired from the intersection extraction unit 120. The vehicle position detection unit 130 calculates the distance from the identified vehicle position to the next intersection where the vehicle will turn right or left from the driving route, and determines whether the vehicle is approaching an intersection where the vehicle will turn right or left. If it is determined that the vehicle is not approaching an intersection where the vehicle will turn right or left (NO in step S20), the process remains in step S20 and continues. If it is determined that the vehicle is approaching an intersection where the vehicle will turn right or left (YES in step S20), the process proceeds to step S30.

In step S30, the object detection unit 141 detects other vehicles from the captured image of the area ahead of the vehicle captured by the camera 200.

The process proceeds to step S40, where the object position measurement unit 142 acquires the relative position of each object measured by the radar 300 with respect to the host vehicle, and measures the relative positions in real space of other vehicles with respect to the host vehicle at each time.

Proceeding to step S50, the object movement direction measurement unit 143 detects the movement direction of the other vehicle based on the relative position in real space of the other vehicle with respect to the host vehicle at each time measured by the object position measurement unit 142 and the movement amount of the host vehicle measured by the host vehicle behavior measurement unit 144.

Proceeding to step S60, the turning path setting unit 150 acquires the turning direction of the host vehicle from the driving path setting unit 110, and acquires the moving direction of the other vehicle from the object moving direction measuring unit 143. The turning path setting unit 150 determines whether or not another vehicle has been detected moving in the opposite direction to the turning direction of the host vehicle in another lane from the acquired moving direction of the other vehicle.

If no vehicle is detected moving in the other lane from the opposite direction to the turning direction of the host vehicle toward the turning direction (NO in step S60), the process returns to step S30 and continues to detect other vehicles around the host vehicle. If a vehicle is detected moving in the other lane from the opposite direction to the turning direction of the host vehicle toward the turning direction (YES in step S60), the process proceeds to step S70.

In step S70, the turning path setting unit 150 calculates a first extension line that passes through the position of another vehicle moving in the other lane from the opposite direction of the turning direction of the host vehicle toward the turning direction, and extends in the moving direction of the other vehicle.

Proceeding to step S80, the turning path planning unit 150 acquires the moving direction of the host vehicle from the host vehicle position detection unit 130, and calculates a first straight driving direction line extending in the straight driving direction of the host vehicle.

Proceeding to step S90, the turning path setting unit 150 generates an arc-shaped curve with a radius equal to the vehicle's minimum turning radius Rmin, and sets the outermost boundary line where the generated curve is tangent to the first extension line and the first straight line.

Proceeding to step S100, the turning path setting unit 150 sets the innermost boundary line, which is an arc-shaped curve having a radius Rmax greater than the minimum turning radius Rmin of the vehicle, which is tangent to the vehicle, the first extension line, and the first straight line.

Proceeding to step S110, the turning path setting unit 150 sets a route setting area, which is an area surrounded by the first extension line, the first straight line, the outermost boundary line, and the innermost boundary line, and sets a turning path for the vehicle in the set route setting area. If the turning path setting unit 150 determines that an object is on the turning path, it searches for a turning path that avoids the object within the route setting area, and sets a turning path that avoids the object. Alternatively, it sets a turning path that stops the vehicle before the object's location.

Proceeding to step S120, the driving support unit 160 controls each control unit that controls the steering, accelerator, and brake, such as the electric power steering unit, engine control unit, and ABS unit, and controls the host vehicle to travel along a turning path. Furthermore, if the turning path setting unit 150 is unable to set a turning path that avoids the object within the route setting area, the driving support unit 160 controls the host vehicle to stop.

By executing the process described above, the driving assistance device can set a turning route within an intersection without using a high-precision map, and control the vehicle to travel along the set turning route.

As described above, the first embodiment provides the following effects:

The driving assistance device 100 calculates a first extension line and a first straight direction line, and sets an outermost boundary line which is an arc-shaped curve having a radius equal to the minimum turning radius of the vehicle and an innermost boundary line which is an arc-shaped curve having a radius larger than the minimum turning radius, which connect the first extension line and the first straight direction line. This allows the driving assistance device 100 to set a route setting area which is an area in which the vehicle can travel and is surrounded by the first extension line, the first straight direction line, the outermost boundary line, and the innermost boundary line, and to set a turning path for the vehicle to turn in the route setting area.

The driving support device 100 sets, as the innermost boundary line, a curve whose rate of change of curvature is equal to or less than a predetermined value and whose direction when connecting to the first extension line coincides with the direction of the first extension line. This allows the driving support device 100 to set the turning path of the host vehicle as a curve with a gradual change in curvature, allowing the host vehicle to turn smoothly.

The driving support device 100 detects the direction of movement of the other vehicle based on the relative position of the other vehicle in real space with respect to the host vehicle at each time and the amount of movement of the host vehicle. This makes it possible to correct the relative position of the other vehicle in real space with respect to the host vehicle to a position in real space (absolute position) based on the amount of movement of the host vehicle, and to detect the direction of movement of the other vehicle by tracking the position of the other vehicle in real space.

When an object is detected on the set turning route, the driving assistance device 100 searches for a turning route that avoids the object within the route setting area. This makes it possible to set a turning route that avoids the object. Furthermore, if it is not possible to set a turning route that avoids the object, a turning route that stops the vehicle before the object's location is set. This makes it possible to avoid a collision with the object.

Second Embodiment
[Configuration of the driving support device]
The configuration of the driving support device according to the second embodiment will be described with reference to Fig. 4. The differences from the first embodiment are that an intersection center estimation unit 170 is further provided, and the processing of the turning path setting unit 150. Therefore, only the intersection center estimation unit 170 and the turning path setting unit 150 will be described, and descriptions of other common configurations will be omitted.

The intersection center estimation unit 170 detects the center position of the intersection where the host vehicle turns right or left. Here, with reference to FIG. 5, the process by which the intersection center estimation unit 170 detects the center position 5 of the intersection will be specifically described. In FIG. 5, the turning direction of the host vehicle 1 is to the right.

First, the intersection center estimation unit 170 calculates the first extension line 3, the second extension line 9, and the second straight line. Next, the intersection center estimation unit 170 detects the intersection of the center line 10 of the first extension line 3 and the second extension line 9 and the second straight line 11 as the center position 5 of the intersection.

The specific processing steps performed by the intersection center estimation unit 170 to calculate the first extension line 3, the second extension line 9, and the second straight line are described below.

The intersection center estimation unit 170 obtains the turning direction of the vehicle 1 from the driving route setting unit 110, and obtains the moving direction of the other vehicles (2A, 2B) from the object moving direction measurement unit 143. The intersection center estimation unit 170 extracts the moving direction of the other vehicle 2A, which moves in the other lane from the opposite direction to the turning direction of the vehicle 1 toward the turning direction, from the obtained moving directions of the other vehicles (2A, 2B), and calculates a first extension line 3 that passes through the position of the other vehicle 2A and extends in the moving direction of the other vehicle 2A.

The intersection center estimation unit 170 extracts the movement direction of the other vehicle 2B moving in the other lane from the direction in which the host vehicle 1 turns toward the opposite direction from the acquired movement directions of the other vehicles 2 (2A, 2B), and calculates a second extension line 9 that passes through the position of the other vehicle 2B and extends in the movement direction of the other vehicle 2B. The intersection center estimation unit 170 acquires the movement direction of the host vehicle 1 from the host vehicle position detection unit 130, and calculates a second straight direction line 11 that extends in the straight direction from the side surface of the host vehicle 1 on the oncoming lane side.

As described above, the intersection center estimation unit 170 calculates the first extension line 3, the second extension line 9, and the second straight line. The intersection center estimation unit 170 then calculates the center line 10 between the first extension line 3 and the second extension line 9, and can detect the intersection of the center line 10 and the second straight line 11 as the center position 5 of the intersection.

Returning to FIG. 4, the turning path setting unit 150 obtains the center position of the intersection detected by the intersection center estimation unit 170, and if the outermost boundary line is located outside the center position of the intersection in the turning radius direction, sets the outermost boundary line closer to the innermost boundary line than the center position of the intersection.

Now, referring to FIG. 6, the process in which the turning path setting unit 150 sets the outermost boundary line 6 closer to the innermost boundary line than the center position 5 of the intersection will be described. The outermost boundary line 6 shown in FIG. 6 is set outside the center position 5 of the intersection in the turning radius direction.

The turning path setting unit 150 determines that the set outermost boundary line 6 is outside the center position 5 of the intersection in the turning radius direction, and changes the outermost boundary line 6 to the outermost boundary line 6A. Specifically, the turning path setting unit 150 generates a straight line 6B that passes through the center position 5 of the intersection and intersects with the first extension line 3 and the first straight direction line 4, and sets the outermost boundary line 6A by changing the outermost boundary line 6 that is set outside the straight line 6B in the turning radius direction to the straight line 6B. The slope of the straight line 6B is calculated using the following formula (1).

This allows the turning path setting unit 150 to set the outermost boundary line 6 closer to the innermost boundary line than the center position of the intersection. Note that the method of setting the outermost boundary line 6 closer to the innermost boundary line than the center position 5 of the intersection is not limited to the above-mentioned method, and for example, the outermost boundary line 6 may be offset until it touches the center position 5 of the intersection.

[Driving support method]
Next, a driving support method according to the second embodiment will be described with reference to Fig. 7. The difference from the first embodiment is that the driving support method further includes steps S101 and S102. Therefore, only the processes in steps S101 and S102 will be described, and descriptions of other common processes will be omitted.

In step S101, the turning path setting unit 150 acquires the center position of the intersection detected by the intersection center estimation unit 170, and determines whether the outermost boundary line is located outside the center position of the intersection in the turning radius direction.

If it is determined that the outermost boundary line is not outside the center position of the intersection in the turning radius direction (NO in step S101), proceed to step S110. If it is determined that the outermost boundary line is outside the center position of the intersection in the turning radius direction (YES in step S101), proceed to step S102.

In step S102, the turning path setting unit 150 sets the outermost boundary line closer to the innermost boundary line than the center position of the intersection.

As explained above, the second embodiment provides the following advantages in addition to those of the first embodiment.

The driving assistance device 100 calculates the first extension line, the second extension line, and the second straight line, and detects the intersection of the center line 10 of the first extension line and the second extension line and the second straight line 11 as the center position 5 of the intersection. This allows the driving assistance device 100 to estimate the center position of the intersection.

The driving support device 100 acquires the center position of the intersection, and if the outermost boundary line is located outside the center position of the intersection in the turning radius direction, sets the outermost boundary line closer to the innermost boundary line than the center position of the intersection. This allows the driving support device 100 to modify the route setting area and set a turning route that prevents a collision with another vehicle traveling in the oncoming lane.

Third Embodiment
The configuration of the driving support device according to the third embodiment will be described with reference to Fig. 8. The differences from the second embodiment are that an object trajectory generation unit 180 is further provided, and the processing of the turning path setting unit 150 and the intersection center estimation unit 170. Therefore, only the object trajectory generation unit 180, the intersection center estimation unit 170, and the turning path setting unit 150 will be described, and the description of other common configurations will be omitted.

The object trajectory generation unit 180 acquires tracking data of the real-space positions (absolute positions) of other vehicles at each time from the object movement direction measurement unit 143, and generates the movement trajectory of other vehicles in real space by connecting the real-space positions of other vehicles at each time.

The intersection center estimation unit 170 estimates the center position of the intersection using the movement trajectories of other vehicles generated by the object trajectory generation unit 180. Here, with reference to Figures 9 and 10, a method in which the intersection center estimation unit 170 estimates the center position of the intersection using the movement trajectories of other vehicles will be specifically described.

First, referring to FIG. 9, a method in which the intersection center estimation unit 170 estimates the intersection center position 5 using the movement trajectories of the other vehicles (2C, 2D) will be specifically described. The intersection center estimation unit 170 acquires from the object trajectory generation unit 180 the movement trajectory 12 of the other vehicle 2C entering the own lane from another lane that intersects with the own lane, and the movement trajectory 13 of the other vehicle 2D entering the oncoming lane of the own lane from another lane that intersects with the own lane. The intersection center estimation unit 170 then sets the center position of the straight line that forms the shortest distance between the movement trajectory 12 and the movement trajectory 13 as the intersection center position 5.

Next, referring to FIG. 10, a method in which the intersection center estimation unit 170 estimates the intersection center position 5 using the movement trajectories of the other vehicles (2A, 2B, 2E, 2F) will be specifically described. The intersection center estimation unit 170 acquires the movement trajectories (16, 17) in the own lane direction of each of the other vehicles (2E, 2F) traveling straight in the own lane and the oncoming lane of the own lane, and the movement trajectories (14, 15) in the intersecting lane direction of each of the other vehicles (2A, 2B) traveling straight in the other lane intersecting the own lane and the oncoming lane of the other lane intersecting the own lane. The intersection center estimation unit 170 then sets the intersection of the center lines (18, 19) between the closest lanes that face each other in each lane direction as the intersection center position 5.

In addition, the intersection center estimation unit 170 can also set the intersection position 5 as the center position 5 of the intersection, which is the intersection between the center line 18 between the closest opposing lanes on the movement trajectory ( 14, 15 ) in the intersecting lane direction and the second straight direction line (not shown).

Returning to FIG. 8, the turning path setting unit 150 sets a range for detecting other vehicles. Specifically, if the vehicle is located within a predetermined distance from an intersection, the detection range is set to be from the first straight line to the exit of the intersection in the direction in which the vehicle is turning.

Now, referring to FIG. 11, the process in which the turning path setting unit 150 sets the detection range 21 will be specifically described. In FIG. 11, the turning direction of the host vehicle 1 is to the right.

First, the turning path setting unit 150 measures the distance 20 to the other vehicle 2A that is closest to the own vehicle among other vehicles moving in the other lane from the opposite direction to the turning direction of the own vehicle 1 toward the turning direction. Specifically, the turning path setting unit 150 measures the distance from the own vehicle to the movement trajectory of the other vehicle 2A. Alternatively, the turning path setting unit 150 may measure the distance from the own vehicle to the first extension line.

Next, the turning path setting unit 150 sets a detection range 21 in which the distance from the first straight line 4 in the direction in which the vehicle turns and in the direction parallel to the other lane that intersects with the vehicle's lane is the measured distance 20. The turning path setting unit 150 sets a route setting area based on the position and moving direction (not shown) of the other vehicle that is traveling at the farthest position from the vehicle within the detection range 21.

Returning to FIG. 8, when the vehicle travels along the driving route and another vehicle is detected within the set detection range that is moving outside the route setting area, the turning route setting unit 150 updates the turning route based on the position and moving direction of the other vehicle that has been detected.

When the direction in which the host vehicle turns is a direction crossing other lanes and multiple movement trajectories of other vehicles moving in the other lanes from the opposite direction to the turning direction of the host vehicle toward the turning direction are detected, the turning path setting unit 150 measures the distance between the movement trajectories of the multiple other vehicles. When the distance between the movement trajectories of the multiple other vehicles is equal to or greater than a predetermined threshold, the turning path setting unit 150 extracts the other vehicle farthest from the host vehicle and sets the innermost boundary line based on the movement trajectory of the other vehicle farthest from the host vehicle.

[Driving support method]
Next, a driving support method according to the third embodiment will be described with reference to Fig. 12. The difference from the second embodiment is that the driving support method further includes steps S51, S52, and S61. Therefore, only the processes in steps S51, S52, and S61 will be described, and descriptions of other common processes will be omitted.

In step S51, the object trajectory generation unit 180 acquires tracking data of the position of the other vehicle from the object movement direction measurement unit 143, and generates the movement trajectory of the other vehicle in real space by connecting the positions of the other vehicles in real space at each time.

Proceeding to step S52, the turning path setting unit 150 measures the distance 20 to the vehicle closest to the vehicle itself among the vehicles moving in the other lane from the opposite direction to the turning direction of the vehicle itself 1. The turning path setting unit 150 sets a detection range in which the measured distance is the distance from the first straight line in the turning direction of the vehicle itself, which is parallel to the other lane that intersects with the vehicle itself.

In step S62, if the direction in which the host vehicle turns is a direction crossing other lanes and multiple movement trajectories of other vehicles moving in the other lanes from the opposite direction to the turning direction of the host vehicle toward the turning direction are detected, the turning path setting unit 150 measures the distance between the movement trajectories of the multiple other vehicles. If the distance between the movement trajectories of the multiple other vehicles is equal to or greater than a predetermined threshold, the turning path setting unit 150 extracts the other vehicle that is farthest from the host vehicle.

As explained above, the third embodiment provides the following advantages in addition to those of the second embodiment.

The driving support device 100 corrects the relative positions of the other vehicles in real space with respect to the vehicle at each time based on the amount of movement of the vehicle at each time, and generates a movement trajectory of the other vehicles in real space by connecting the corrected positions of the other vehicles in real space at each time. This allows the driving support device 100 to correct the relative positions of the other vehicles in real space with respect to the vehicle to positions (absolute positions) in real space based on the amount of movement of the vehicle, and to generate a movement trajectory of the other vehicles by connecting the positions of the other vehicles in real space.

The driving support device 100 estimates the center position of the intersection using the movement trajectory of the other vehicle. This makes it possible to estimate the center position of the intersection using the movement trajectory of the other vehicle in addition to the extension line of the direction in which the other vehicle is moving.

The driving assistance device 100 sets the center position of the intersection as the center position of the straight line that forms the shortest distance between the movement trajectory of another vehicle entering the own lane from another lane that intersects with the own lane and the movement trajectory of another vehicle entering the oncoming lane from another lane that intersects with the own lane. This makes it possible to set the center position of the intersection based on the movement trajectory of the other vehicle when it actually turns around the intersection.

The driving support device 100 acquires the movement trajectories in the own lane direction of each of the other vehicles traveling straight in the own lane and the oncoming lane of the own lane, and the movement trajectories in the cross lane direction of each of the other vehicles traveling straight in the other lane that intersects the own lane and the oncoming lane of the other lane that intersects the own lane. The driving support device 100 then sets the intersection of the center lines between the closest lanes that are opposed to each other in each lane direction as the center position of the intersection. This allows the driving support device 100 to set the center position of the intersection based on the movement trajectories in the own lane direction and the movement trajectories in the cross lane direction of the other vehicles when they actually travel straight through the intersection.

The driving support device 100 sets the intersection of the center line between the closest opposing lanes on the movement trajectory in the cross lane direction and the second straight direction line as the center position of the intersection. This allows the driving support device 100 to set the center position of the intersection even when only the movement trajectory in the cross lane direction is detected as the movement trajectory of the other vehicle.

By setting a detection range for detecting other vehicles, the driving assistance device 100 can exclude other vehicles that are not relevant when setting the turning path of the vehicle.

When the position of the host vehicle is within a predetermined distance from the intersection, the driving assistance device 100 sets the detection range from the first straight line to the exit of the intersection in the direction in which the host vehicle turns, as the detection range. This allows the driving assistance device 100 to set the detection range at an appropriate timing by setting the detection range when the position of the host vehicle is within a predetermined distance from the intersection. Furthermore, by setting the detection range from the first straight line to the exit of the intersection in the direction in which the host vehicle turns, the driving assistance device 100 can set the turning path of the host vehicle based on the position and moving direction of another vehicle traveling near the intersection exit, and can set the turning path taking into account the road shape after passing through the intersection.

The driving assistance device 100 can estimate the approximate size of an intersection by measuring the distance to the closest vehicle to the vehicle among other vehicles moving in other lanes in the intersection from the opposite direction to the turning direction of the vehicle. The driving assistance device 100 can set the detection range to include the intersection on the turning direction side of the vehicle by setting the detection range in which the distance from the first straight line to the other lane in the turning direction of the vehicle and intersecting the vehicle's lane is the measured distance. This makes it possible to set the turning path of the vehicle based on the position and moving direction of other vehicles traveling near the intersection exit, and to set the turning path taking into account the road shape after passing through the intersection.

The driving support device 100 updates the detection range as the vehicle moves, and when another vehicle moving outside the route setting area is newly detected in the detection range, the driving support device 100 updates the turning route based on the position and moving direction of the detected other vehicle. This allows the driving support device 100 to obtain information on other vehicles that could not be detected due to blind spots, etc., and set a turning route based on the newer position and moving direction of the other vehicle.

When the direction in which the host vehicle turns is a direction in which the host vehicle turns across other lanes and multiple movement trajectories of other vehicles moving in the opposite direction to the turning direction of the host vehicle are detected, the driving support device 100 measures the interval between the movement trajectories of the multiple other vehicles. This allows the driving support device 100 to estimate the number of other lanes into which the host vehicle will turn and enter from the interval between the movement trajectories of the other vehicles. Then, when the interval between the movement trajectories is equal to or greater than a predetermined threshold, the driving support device 100 can cause the host vehicle to enter the first lane of the entering lane by setting the innermost boundary line based on the movement trajectory of the other vehicle that is farthest from the host vehicle.

As described above, an embodiment of the present invention has been described, but the descriptions and drawings that form part of this disclosure should not be understood as limiting this invention. Various alternative embodiments, examples, and operating techniques will become apparent to those skilled in the art from this disclosure.

100 Driving support device 120 Intersection extraction unit 150 Turning path setting unit

Claims (13)

A driving assistance method for assisting a vehicle in traveling along a driving route, comprising:
extracting an intersection at which a lane on which the host vehicle is traveling intersects with another lane, the intersection being set so that the traveling route makes a turn from the host vehicle lane to the other lane;
calculating a first extension line passing through a position of another vehicle moving in the other lane at the intersection from a direction opposite to a direction in which the host vehicle turns toward the turning direction of the other vehicle or in the opposite direction to the moving direction of the other vehicle, and a first straight-ahead direction line passing through the position of the host vehicle and extending in the straight-ahead direction of the host vehicle;
an outermost boundary line which is an arc-shaped curve having a radius equal to a minimum turning radius of the host vehicle and which is tangent to the first extension line and the first straight-line direction line, and an innermost boundary line which is an arc-shaped curve having a radius larger than the minimum turning radius;
a route setting area that is an area surrounded by the first extension line, the first straight direction line, the outermost boundary line, and the innermost boundary line, and a turning route of the host vehicle at the intersection is set;
A driving support method comprising controlling each control unit for controlling a steering wheel, an accelerator, and a brake, which are provided in the host vehicle, so that the host vehicle travels along the turning path. calculating a second extension line that passes through a position of another vehicle moving in the other lane at the intersection from a direction in which the host vehicle turns toward a direction opposite to the turning direction of the other vehicle and that extends in the moving direction of the other vehicle or in the opposite direction to the turning direction, and a second straight direction line that extends in the straight direction from a side surface of the host vehicle on an oncoming lane side;
an intersection point between a center line of the first extension line and the second extension line and the second straight direction line is detected as a center position of the intersection;
The driving support method according to claim 1 , wherein the outermost boundary line is set closer to the innermost boundary line than to a center position of the intersection. The driving assistance method according to claim 1, characterized in that as the innermost boundary line, a curve is set in which a rate of change of curvature is equal to or less than a predetermined value, and the curve whose direction when connected to the first extension line coincides with a direction of the first extension line is set. measuring a relative position in real space of the other vehicle with respect to the host vehicle at each time and a movement amount of the host vehicle;
The method for assisting a vehicle according to claim 1 , wherein a moving direction of the other vehicle is detected from a relative position of the other vehicle in real space at each time and an amount of movement of the host vehicle. correcting a relative position of the other vehicle with respect to the host vehicle in real space at each time based on an amount of movement of the host vehicle at each time;
The driving support method according to claim 4, wherein the corrected positions of the other vehicle in real space at each time are connected together to generate a movement trajectory of the other vehicle in real space. setting a center position of the intersection as a center position of a straight line that forms a shortest distance between a movement trajectory of the other vehicle entering the own lane from the other lane that intersects with the own lane and a movement trajectory of the other vehicle entering an oncoming lane from the other lane that intersects with the own lane,
The driving support method according to claim 1 , wherein the outermost boundary line is set closer to the innermost boundary line than to a center position of the intersection. set, as a center position of the intersection, an intersection point between center lines of the nearest lanes opposed to each other in each lane direction, a movement trajectory in the own lane direction of each of the other vehicles traveling straight in the own lane and the oncoming lane of the own lane, and a movement trajectory in the intersecting lane direction of each of the other vehicles traveling straight in the other lane intersecting with the own lane and the oncoming lane of the other lane intersecting with the own lane,
The driving support method according to claim 1 , wherein the outermost boundary line is set closer to the innermost boundary line than to a center position of the intersection. 2. The driving assistance method according to claim 1, wherein when the position of the host vehicle is within a predetermined distance from the intersection, a detection range for detecting the other vehicle is set to be from the first straight line to an exit of the intersection in the direction in which the host vehicle is turning. measuring a first distance to the other vehicle that is closest to the host vehicle among the other vehicles that are moving in the other lane at the intersection from a direction opposite to a direction in which the host vehicle turns toward the turning direction;
The detection range is set so that the first distance is a distance from the first straight line in a direction in which the host vehicle turns and which is parallel to the other lane that intersects with the host lane;
The driving support method according to claim 8 , wherein the route setting area is set based on a position and a moving direction of the other vehicle that is traveling at a position farthest from the host vehicle within the detection range. Detecting an object on the turning path;
searching for a turning path that avoids the object within the range of the route setting area;
The driving support method according to claim 1 , further comprising the step of controlling the host vehicle to stop when a turning path that avoids the object cannot be set. The driving assistance method according to claim 8, characterized in that, when another vehicle moving outside the route setting area is newly detected in the detection range as the vehicle travels along the driving route, the turning route is updated based on the position and moving direction of the detected other vehicle. When the turning direction of the host vehicle is a direction in which the host vehicle turns across the other lane, and a plurality of movement trajectories of the other vehicle moving on the other lane from a direction opposite to the turning direction of the host vehicle toward the turning direction are detected, measuring an interval between the movement trajectories of the plurality of the other vehicles;
The driving support method according to claim 5 , wherein, when the distance is equal to or greater than a predetermined threshold, the innermost boundary line is set based on a movement trajectory of the other vehicle that is farthest from the host vehicle. A driving assistance device that assists a vehicle in traveling along a driving route,
an intersection extraction unit that extracts an intersection at which a lane on which the host vehicle is traveling intersects with another lane, and in which the travel route is set to turn from the host lane to the other lane;
a turning path setting unit that calculates a first extension line that passes through the position of another vehicle moving in the other lane at the intersection from a direction opposite to the direction of turning of the host vehicle toward the turning direction of the host vehicle and a first straight direction line that passes through the position of the host vehicle and extends in the straight direction of the host vehicle, sets an outermost boundary line that is an arc-shaped curve with a radius equal to the minimum turning radius of the host vehicle and is tangent to the first extension line and the first straight direction line, and an innermost boundary line that is an arc-shaped curve with a radius larger than the minimum turning radius, and sets a turning path of the host vehicle at the intersection in a route setting area that is an area surrounded by the first extension line, the first straight direction line, the outermost boundary line, and the innermost boundary line.

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