WO2025069335A1 - Leaning vehicle fcw device and leaning vehicle fcw method - Google Patents

Abstract

Provided is a leaning vehicle forward-collision-warning (FCW) device that is used in a leaning vehicle in which a vehicle body tilts toward a turning inner side when making a turn, said leaning vehicle FCW device comprising: a warning unit that issues a warning to a driver; and one or more control units that execute host vehicle course prediction for predicting the course of a host vehicle and host vehicle peripheral object position detection for detecting the position of an object around the host vehicle, that calculate a possibility of collision between the host vehicle and the object using a result of the hot vehicle course prediction and a result of the host vehicle peripheral object position detection, and that execute warning control for controlling whether a warning is issued by the warning unit on the basis of the possibility of collision. The leaning vehicle FCW device further comprises: a monocular camera that is fixed to the host vehicle and that captures an image of the periphery of the host vehicle; and a turning state detection unit that detects a physical quantity relating to a yaw rate of the host vehicle. The control unit executes the host vehicle peripheral object position detection on the basis of the captured image captured by the monocular camera, and executes the host vehicle course prediction in consideration of the yaw rate of the host vehicle obtained from the detection result of the turning state detection unit, and uses the obtained results to execute the warning control as described in the following situations. Situation 1: When the host vehicle is turning on a road without white lines, if a first preceding vehicle is turning ahead of the host vehicle with the same turning radius as the host vehicle and at a vehicle speed smaller than the vehicle speed of the host vehicle, the control unit executes the warning control so that a warning is issued by the warning unit when the possibility of collision between the host vehicle and the first preceding vehicle becomes equal to or greater than a predetermined collision possibility. Situation 2: When the host vehicle is turning on a road without white lines, if a second preceding vehicle is advancing straight ahead of the host vehicle at a vehicle speed smaller than the vehicle speed of the host vehicle, and the center position in the vehicle width direction of a front wheel of the host vehicle is in a meandering state in which the front wheel is meandering centered on a straight line parallel to the advancing direction of the second preceding vehicle within a range that falls within the vehicle width of the host vehicle, and the center position in the vehicle width direction of the front wheel of the host vehicle is positioned within the vehicle width of the second preceding vehicle when viewed from the advancing direction of the second preceding vehicle, the control unit executes the warning control so that a warning is issued by the warning unit when the possibility of collision between the host vehicle and the second preceding vehicle becomes equal to or greater than a predetermined collision possibility.

Description

FCW device for lean vehicle and FCW method for lean vehicle

This disclosure relates to a forward collision warning (FCW) device for a lean vehicle and a forward collision warning method for a lean vehicle that issues a FCW to a driver of the lean vehicle.

　Conventionally, FCW devices are known that issue a warning to a driver of a lean vehicle based on the possibility of a collision with a surrounding object. A lean vehicle turns by tilting the body. An example of a lean vehicle is a motorcycle. For example, Patent Document 1 discloses a device that issues a warning based on the positional relationship between a lean vehicle and a preceding vehicle traveling in front of the lean vehicle when multiple lean vehicles are traveling together. Patent Document 2 discloses a system that captures an image of the front using a camera attached to the lean vehicle, detects surrounding vehicles using the captured image, and issues a warning.

International Publication No. 2021/060357 Special Publication No. 2021-526681

Lean vehicles tend to be lighter and more compact than non-lean vehicles, which do not tilt the body left or right when turning. For this reason, lean vehicles are characterized by being more prone to wobbling when subjected to disturbances such as unevenness in the road surface while traveling straight, compared to non-lean vehicles. The technology disclosed in Patent Documents 1 and 2 does not take into consideration FCW control in situations where wobbling occurs due to disturbances such as unevenness in the road surface while the lean vehicle is traveling straight.

The purpose of this disclosure is to provide an FCW device for lean vehicles and an FCW method for lean vehicles that perform FCW control different from that proposed in the past.

The inventors of the present application have considered activating an FCW device while a lean vehicle is turning. The FCW device detects objects around the host vehicle and then selects from the detected objects those objects that are likely to collide with the host vehicle. The numerical value indicating the degree of risk of the host vehicle colliding with the object changes depending on whether or not the object is on the path of the host vehicle. The inventors of the present application have conceived the idea that by predicting the path of the host vehicle taking into account the turning state of the vehicle, it is possible to execute warning control targeting objects on the turning path of the host vehicle.

Furthermore, the inventors of the present application have noticed that in lean vehicles, compared to four-wheeled vehicles, the body is more likely to sway when traveling straight due to disturbances such as unevenness in the road surface. When the body sways when traveling straight due to disturbances, if the swaying is recognized as a turn and a course prediction is performed based on that, there is a possibility that a predicted course different from the actual course will be obtained. Therefore, the inventors of the present application have investigated an FCW device for lean vehicles that can execute FCW control that takes into account the swaying state that occurs due to disturbances when traveling straight and the turning state.

While the situations in which alarm control using FCW devices can be performed are expanding, the bodies of lean vehicles are smaller than those of four-wheeled vehicles, limiting the space available for mounting the devices, so there is a need to reduce the processing load and increase the design freedom of hardware resources.

In this way, when the FCW device is operated while the lean vehicle is turning, it is necessary to suppress an increase in the processing load while taking into consideration the wobbling state that occurs due to disturbances when the lean vehicle is traveling straight and the turning state.

In order to address both of the conflicting issues discussed above, the FCW device for lean vehicles disclosed herein employs the following configuration.

An FCW device for a lean vehicle according to one embodiment of the present disclosure includes an alarm unit that issues an alarm to a driver, and one or more control units that execute a host vehicle path prediction that predicts a path of the host vehicle and a host vehicle peripheral object position detection that detects the positions of objects around the host vehicle, calculate a possibility of a collision between the host vehicle and an object using the results of the host vehicle path prediction and the results of the host vehicle peripheral object position detection, and execute an alarm control that controls whether or not an alarm is issued by the alarm unit based on the possibility of collision. The FCW device for a lean vehicle is used in a lean vehicle whose body tilts to the inside of a turn when turning, and further includes a monocular camera that is fixed to the host vehicle and captures an image of the periphery of the host vehicle, and a turning state detection unit that detects a physical quantity related to the yaw rate of the host vehicle, and the control unit executes the position detection of the host vehicle peripheral object based on an image captured by the monocular camera, and executes the host vehicle path prediction that takes into account the yaw rate of the host vehicle obtained from the detection result of the turning state detection unit, and executes the alarm control using the obtained result as described in each of the following situations.
Situation 1: When the host vehicle is turning on a road without white lines and a first preceding vehicle is turning in front of the host vehicle at a speed slower than the host vehicle's speed and with the same turning radius as the host vehicle, the control unit executes warning control so that the warning unit issues a warning when the possibility of a collision between the host vehicle and the first preceding vehicle reaches or exceeds a predetermined collision possibility.
Situation 2: When the host vehicle is traveling straight on a road without white lines, and a second leading vehicle is traveling straight ahead of the host vehicle at a speed slower than the host vehicle's speed, and the center position of the vehicle width direction of the front wheels of the host vehicle is in a zigzag state, zigzagging within a range that falls within the vehicle width of the host vehicle, centered on a straight line parallel to the direction of travel of the second leading vehicle, and the center position of the vehicle width direction of the front wheels of the host vehicle is located within the vehicle width of the second leading vehicle when viewed from the direction of travel of the second leading vehicle, the control unit executes warning control so that the warning unit issues a warning when the possibility of a collision between the host vehicle and the second leading vehicle reaches or exceeds a predetermined collision possibility.

In the above configuration, the control unit may execute the warning control as described in the following situations.
Situation 3: When the host vehicle is traveling straight on a road without white lines, a third leading vehicle is traveling straight ahead of the host vehicle at the same speed as the host vehicle, and the host vehicle is in a serpentine state in which the center position of the vehicle width of the front wheels of the host vehicle is centered on a straight line parallel to the direction of travel of the third leading vehicle and falls within the vehicle width of the host vehicle, and the center position of the vehicle width of the front wheels of the host vehicle is located within the vehicle width of the third leading vehicle when viewed from the direction of travel of the third leading vehicle, and a fourth leading vehicle is turning at a speed slower than the speed of the host vehicle, following a turning path predicted from the yaw rate generated by the host vehicle traveling straight in the serpentine state, the control unit executes warning control so that an warning is not issued by the warning unit.

In the above configuration, the FCW device for lean vehicles may further include a vehicle speed detection unit that detects the vehicle speed of the host vehicle. The control unit may determine whether the host vehicle is turning based on the yaw rate obtained from the detection result of the turning state detection unit, and if it is determined that the host vehicle is turning, may execute the host vehicle path prediction based on the yaw rate obtained from the detection result of the turning state detection unit and the vehicle speed detected by the vehicle speed detection unit, and if the host vehicle is in the swerving state, may execute the host vehicle path prediction by assuming that the host vehicle is traveling straight regardless of the value of the yaw rate.

In the above configuration, when the yaw rate is defined as positive when the host vehicle turns to the right relative to the traveling direction and as negative when the host vehicle turns to the left relative to the traveling direction, if the duration for which the sign of the yaw rate obtained from the detection result of the turning state detection unit continues to show the same sign is shorter than a predetermined threshold time, the control unit may determine that the host vehicle is traveling straight regardless of the value of the yaw rate and perform the host vehicle trajectory prediction.

An FCW method for a lean vehicle according to one embodiment of the present disclosure includes an alarm unit that issues an alarm to a driver, and one or more control units that execute host vehicle path prediction that predicts a path of the host vehicle and host vehicle peripheral object position detection that detects the positions of objects around the host vehicle, calculate a collision possibility between the host vehicle and an object using the host vehicle path prediction result and the host vehicle peripheral object position detection result, and execute alarm control that controls whether or not an alarm is issued by the alarm unit based on the collision possibility. The FCW method includes the steps of: capturing an image of the surroundings of the host vehicle with a monocular camera fixed to the host vehicle; acquiring an image from the monocular camera and detecting the positions of objects around the host vehicle; acquiring a yaw rate of the host vehicle from a detection result of a turning state detection unit that detects a physical quantity related to the yaw rate of the host vehicle; predicting the host vehicle's course taking into account the yaw rate obtained from the detection result of the turning state detection unit; and executing the warning control as described in each of the following situations using the result of the host vehicle's course prediction and the result of the position detection of objects around the host vehicle.
Situation 1: When the host vehicle is turning on a road without white lines and a first preceding vehicle is turning in front of the host vehicle at a speed slower than the host vehicle's speed and with the same turning radius as the host vehicle, the control unit executes the warning control so that the warning unit issues a warning when the possibility of a collision between the host vehicle and the first preceding vehicle reaches or exceeds a predetermined collision possibility.
Situation 2: When the host vehicle is traveling straight on a road without white lines, a second leading vehicle is traveling straight ahead of the host vehicle at a speed slower than the host vehicle's speed, and the center position of the vehicle width direction of the front wheels of the host vehicle is in a zigzag state, zigzagging within a range that falls within the vehicle width of the host vehicle, centered on a straight line parallel to the direction of travel of the second leading vehicle, and the center position of the vehicle width direction of the front wheels of the host vehicle is located within the vehicle width of the second leading vehicle when viewed from the direction of travel of the second leading vehicle, the control unit executes the warning control so that the warning unit issues a warning when the possibility of a collision between the host vehicle and the second leading vehicle reaches a predetermined collision possibility or greater.

In the above-mentioned configuration, the method may further include the step of executing the warning control as described in the following situations.
Situation 3: When the host vehicle is traveling straight on a road without white lines, a third leading vehicle is traveling straight ahead of the host vehicle at the same speed as the host vehicle, and the host vehicle is in a serpentine state in which the center position of the vehicle width of the front wheels of the host vehicle is centered on a straight line parallel to the direction of travel of the third leading vehicle and falls within the vehicle width of the host vehicle, and the center position of the vehicle width of the front wheels of the host vehicle is located within the vehicle width of the third leading vehicle when viewed from the direction of travel of the third leading vehicle, and a fourth leading vehicle is turning at a speed slower than the speed of the host vehicle, following a turning path predicted from the yaw rate generated by the host vehicle traveling straight in the serpentine state, the control unit executes the warning control so that the warning unit does not issue a warning.

In the above configuration, it is determined whether the host vehicle is turning based on the yaw rate obtained from the detection result of the turning state detection unit, and if it is determined that the host vehicle is turning, the host vehicle path prediction is performed based on the yaw rate obtained from the detection result of the turning state detection unit and the vehicle speed detected by a vehicle speed detection unit that detects the vehicle speed of the host vehicle, and if the host vehicle is in the meandering state, the host vehicle path prediction may be performed assuming that the host vehicle is traveling straight regardless of the value of the yaw rate.

In the above configuration, if the yaw rate is defined as positive when the vehicle turns to the right relative to the traveling direction, and as negative when the vehicle turns to the left relative to the traveling direction, if the duration during which the sign of the yaw rate obtained from the detection result of the turning state detection unit continues to show the same sign is shorter than a predetermined threshold time, the vehicle path prediction may be performed assuming that the vehicle is traveling straight regardless of the value of the yaw rate.

The FCW device for lean vehicles and the FCW method for lean vehicles disclosed herein can provide an FCW device for lean vehicles and an FCW method for lean vehicles that perform FCW control different from that proposed in the past.

[Lean vehicle]
The lean vehicle according to the present disclosure is a vehicle in which the vehicle body tilts to the right when turning right and tilts to the left when turning left. The left and right directions are directions seen from the driver driving the lean vehicle. In the present disclosure, the right hand side is described as the right, the left hand side is described as the left, the front is described as the front, and the rear is described as the rear, as seen from the driver of the lean vehicle. The "own vehicle" described in the present disclosure refers to a lean vehicle. The lean vehicle includes a motorcycle. The own vehicle described in the present disclosure refers to a lean vehicle. The inclination of the lean vehicle refers to the body of the lean vehicle being inclined to the left or right with respect to the vertical direction. The inclination of the lean vehicle can be represented by the inclination angle between the body of the lean vehicle and the vertical direction. When the lean vehicle is traveling straight, the inclination angle is 0 degrees, and when the lean vehicle is turning, the inclination angle is greater than 0 degrees. The lean vehicle includes at least one front wheel and at least one rear wheel. For example, a lean vehicle may have two front wheels and one or two rear wheels, or one front wheel and one or two rear wheels. The lean vehicle may have steered front wheels or steered rear wheels. The lean vehicle runs by driving the drive wheels with a drive source. The drive source may be an internal combustion engine, an electric motor, or a hybrid drive source including an engine and an electric motor.

[FCW device for lean vehicles]
The FCW device for a lean vehicle described in the present disclosure includes an alarm unit, one or more control units, a monocular camera, and a turning state detection unit. The FCW device may further include a vehicle speed detection unit. The FCW device is mounted on a lean vehicle and used.

[white line]
The white lines described in this disclosure refer to lines drawn on the road to indicate the vehicle's driving lane, and are not intended to be limited in color. For example, the lines may be drawn in other colors, such as yellow. Such lines on the road may be called outer road lines, shoulder strips, diagonal boundary lines, dividing lines, etc. The FCW device can perform FCW control without detecting white lines. In this disclosure, when it is described that the host vehicle is traveling on a road without white lines, this indicates that the FCW control can be performed even on roads without white lines, and is not intended to limit the roads on which lean vehicles travel to roads without white lines.

[situation]
In this disclosure, situations numbered and described, such as "Situation 1," indicate examples of situations in which the operation of the FCW device can be confirmed. One feature of the FCW device is that it executes processes such as detecting the position of objects around the vehicle and predicting the vehicle's path, and can change whether or not to issue an alarm depending on the situation. Each situation numbered and described indicates that the alarm control executed by the FCW device can be confirmed by reproducing this situation, and is not intended to limit the operation of the FCW device to the described situation.

[Meandering state]
The meandering state described in this disclosure includes a state in which the center position of the front wheels of a lean vehicle in the vehicle width direction meanders within the vehicle width of the lean vehicle, centered on a straight line parallel to the traveling direction of the preceding vehicle traveling straight ahead of the lean vehicle. In other words, if a strip-shaped area of the same width as the vehicle width of the lean vehicle is set on the road, the meandering state includes the driving state of the lean vehicle that runs while changing the direction and position of the front wheels within the range that fits within this area.
The meandering state is merely an example of a driving state to show one of the characteristics of the FCW control executed when a lean vehicle stumbles, and is not intended to limit the driving state considered to be a meandering state. For convenience of explanation, it is called a meandering state, but it is not intended to limit the driving state to a driving state in which the direction of the front wheels is changed continuously from left to right. The direction or position of the front wheels may be changed only once in the meandering state.
For example, a meandering state is also included when a lean vehicle is moving straight and then changes the direction of the front wheels once to the right or left, then returns to its original position to the right or left from the original straight path and continues moving straight at that position. A meandering state is also included when a lean vehicle changes the direction of the front wheels once to the right or left, then changes the direction of the front wheels again to the left or right, then returns to its original straight path and continues moving straight. If a lean vehicle has multiple front wheels, it is sufficient to determine whether or not the vehicle is in a meandering state for any one of the front wheels.

[Alarm section]
The alarm unit described in the present disclosure is an alarm device that issues an alarm to at least the driver of the lean vehicle. The alarm unit issues an alarm targeting at least one of the senses of hearing, vision, and touch. An alarm targeting the sense of hearing may be issued by emitting a voice or an alarm sound from a speaker. An alarm targeting the sense of sight may be issued by displaying information on a display device or illuminating a light-emitting device. An alarm device such as a speaker, a display device, or a light-emitting device may be installed, for example, on a handle or in the vicinity thereof. If the driver wears a helmet, the alarm device may be mounted on the helmet. A device such as a speedometer or a navigation device provided in the lean vehicle may be used as an alarm device. An alarm targeting the sense of touch may be issued by vibrating at least one of a handle, a helmet, and a seat.

[Control unit]
The control unit described in the present disclosure controls each unit constituting the FCW device. The control unit controls each unit, thereby realizing the functions and operations of the FCW device described in the present disclosure. The control unit is a control device that executes the FCW control. The FCW control includes vehicle path prediction, position detection of objects around the vehicle, and alarm control. The FCW device may include multiple control units, and multiple processes may be executed in parallel by separate control units. For example, the FCW device may be configured such that a process related to vehicle path prediction and a process related to position detection of objects around the vehicle are executed in parallel at the same time. The control unit calculates a numerical value indicating the possibility of collision between the vehicle and the object based on the prediction result of the path of the vehicle and the result of position detection of objects around the vehicle. For example, the time to collision (TTC) may be used as a numerical value indicating the possibility of collision. In addition, the numerical value indicating the possibility of collision may be, for example, the distance between the lean vehicle and the object, the relative moving speed, or the like. The control unit determines whether or not an alarm is necessary and the timing of issuing an alarm based on the possibility of collision, and executes alarm control to issue an alarm from the alarm device based on the determination result. The control unit can continuously execute warning control while the lean vehicle is traveling, regardless of whether the lean vehicle is traveling straight or turning. A program corresponding to the control unit is prepared in advance in a non-volatile storage device, and the function and operation of the control unit are realized by executing this program by predetermined hardware. The control unit may be realized by an ECU (Electronic Control Unit) for vehicle control, or the FCW device may have a dedicated control unit.

[Monocular camera]
The monocular camera described in the present disclosure is an imaging device that captures images of the periphery of a lean vehicle. The FCW device can execute FCW control using one monocular camera that is smaller than a stereo camera. The monocular camera is fixed to the lean vehicle and used. The monocular camera can capture images of the road ahead of the lean vehicle. The monocular camera captures images of a preceding vehicle traveling ahead of the lean vehicle while the lean vehicle is traveling straight or turning, a vehicle stopped or parked in front of the lean vehicle, and other obstacles. The preceding vehicles captured by the monocular camera include vehicles traveling on a predicted path obtained by vehicle path prediction and vehicles traveling at a position deviating from the predicted path. The monocular camera captures moving images or continuous still images, so that objects around the lean vehicle are continuously captured.

[Turning state detection unit]
The turning state detection unit described in the present disclosure is a detection device that detects a physical quantity related to the yaw rate of a lean vehicle. The yaw rate and yaw angle of the lean vehicle can be identified from the physical quantity detected by the turning state detection unit. For example, the turning state detection unit may detect either the yaw rate or the yaw angle, and calculate the other based on the detection result. For example, an IMU (Inertial Measurement Unit) may be used as the turning state detection unit. Other devices such as a GPS (Global Positioning System) or a gyro sensor may be used as the turning state detection unit.

[Vehicle speed detection section]
The vehicle speed detection unit described in the present disclosure is a detection device that detects the running speed of a lean vehicle. For example, a device that detects the vehicle speed based on the rotation speed of the front or rear wheels and the outer diameter of the tires obtained by using a rotation sensor is used as the vehicle speed detection unit. Other devices, such as a device that detects the vehicle speed from position information by GPS, may be used as the vehicle speed detection unit.

[Vehicle Path Prediction]
The vehicle path prediction described in the present disclosure is a process of predicting the path of the vehicle. The vehicle path prediction also includes predicting the path on the image captured by the monocular camera. Note that the prediction of the path on the captured image may be performed by mapping the path of the vehicle predicted in the three-dimensional coordinates of the real world to the corresponding planar coordinates on the captured image. The planar coordinates on the captured image are, for example, an orthogonal coordinate system with the center of the captured image as the origin. When the lean vehicle is traveling straight, the FCW device can predict the path of the lean vehicle on the image captured by the monocular camera based on the mounting position and mounting angle, imaging direction, imaging range, etc. of the monocular camera on the lean vehicle. When the lean vehicle is turning, the FCW device can predict a curved path as the path of the turning lean vehicle based on the detection result by the turning state detection unit. When the lean vehicle is turning, the FCW device can predict the path of the turning lean vehicle by curvature-correcting the predicted path on the captured image, which is obtained by assuming that the lean vehicle is traveling straight, based on the detection result by the turning state detection unit. The FCW device can predict the path of the turning lean vehicle in approximately real time after acquiring the captured image by the monocular camera while the lean vehicle is traveling.

[Detection of the Position of Objects Surrounding the Vehicle]
The position detection of an object around the vehicle described in the present disclosure is a process of detecting objects around the vehicle and identifying the position of each object. The position detection of an object around the vehicle is performed using an image captured by a monocular camera. Here, the position of an object may be a position on the image captured by the monocular camera. By performing image analysis to detect objects on the image captured by the monocular camera, the objects shown in the captured image and the positions of each object are detected. Such image analysis may be called object detection, object recognition, or the like. Objects detected from the captured image include a preceding vehicle traveling ahead of the lean vehicle while the lean vehicle is traveling straight and while the lean vehicle is turning, a vehicle stopped or parked ahead, and other obstacles. The preceding vehicle detected from the captured image includes a vehicle traveling on a predicted path obtained by the vehicle path prediction and a vehicle traveling at a position deviated from the predicted path. When the detected vehicle is described as a "preceding vehicle," it refers to a vehicle traveling ahead of the lean vehicle in the same direction as the lean vehicle. The FCW device can detect the positions of objects around the vehicle in approximately real time after capturing an image using a monocular camera while the vehicle is traveling lean.

[Possibility of collision]
The collision probability described in the present disclosure is a numerical value indicating the possibility of a collision between the lean vehicle and a surrounding object. For example, the relative movement speed of the object with respect to the lean vehicle, the distance between the lean vehicle and the object, the time until the lean vehicle collides with the object, etc. can be used as the collision probability. The collision probability is calculated based on the predicted path of the host vehicle obtained by executing the host vehicle path prediction, the position of each object obtained by executing the position detection of the object around the host vehicle, and the relative movement of each detected object and the lean vehicle. For example, the distance from the object detected on the captured image to the lean vehicle is specified by detecting the position of the object around the host vehicle. The direction and movement speed of the detected object relative to the lean vehicle are specified by comparing multiple captured images captured in succession. The time until the collision is specified based on the distance from the object to the lean vehicle and the relative movement speed. Based on the result of comparing the value indicating the collision probability with a threshold value prepared in advance according to the type of collision probability, an alarm control is performed to determine whether or not an alarm is required by the alarm unit and the timing of issuing the alarm. For example, when the time to collision (TTC) is used as the collision probability, a predetermined time is set as a threshold, and alarm control is performed to issue an alarm when the time to collision reaches the threshold time.

[Hardware configuration]
The FCW device according to the present disclosure is characterized in that it executes FCW control that has not been seen in the past. The hardware configuration of the FCW device according to the present disclosure and a lean vehicle equipped with the FCW device can be implemented by a person skilled in the art using the hardware configurations of devices and lean vehicles known in prior art documents, other publicly known documents, and conventional technology. For this reason, detailed descriptions of the hardware configurations of the FCW device and the lean vehicle are omitted.

[others]
In this disclosure, a process described as being performed "based on A" or "taking A into consideration" indicates that the process is performed using A, but the information used is not limited to A, and information other than A may be used.
In the present disclosure, when options are described as "at least one," this means that all possible combinations of multiple options are included.
When used in this disclosure, the words "including,""comprising,""having," and their derivatives are intended to indicate that other content may be included in addition to the listed content.
In the present disclosure, the words "may" and "may" are used to indicate that the examples are non-exclusive and are not limited to the examples set forth.
In the present disclosure, unless the number of components is clearly specified, the number of the components may be one or more.
Unless otherwise defined, terms described in this disclosure have the general meaning as understood by a person skilled in the art of FCW control.
The FCW device according to the present disclosure is not limited to the configurations described in the following embodiments or the configurations shown in the drawings. The FCW device according to the present disclosure can also be implemented by combining a plurality of the embodiments described below. The FCW device according to the present disclosure can also be implemented in forms other than the embodiments described below, and can also be implemented by modifying the embodiments described below.

FIG. 1 is a diagram for explaining an overview of a lean vehicle FCW device according to a first embodiment of the present disclosure. FIG. 2 is a diagram for explaining an overview of a lean vehicle FCW device according to a second embodiment of the present disclosure. FIG. 3 is a diagram for explaining an overview of a lean vehicle FCW device according to a third embodiment of the present disclosure. FIG. 4 is a diagram for explaining an example of a process for determining whether a lean vehicle has started to turn or has started to wobble while traveling straight.

[First embodiment]
A lean vehicle FCW device according to a first embodiment of the present disclosure will be described with reference to Fig. 1. As shown in Fig. 1, a lean vehicle FCW device 2 is provided on a lean vehicle 1 that turns by tilting the vehicle body to the inside of the turn. The tilt angle θ shown in Fig. 1 indicates the tilt angle of the lean vehicle 1 with respect to the vertical direction. When the lean vehicle 1 is traveling straight, the tilt angle θ is 0 degrees, and when turning, the tilt angle θ is greater than 0 degrees.

The FCW device 2 includes an alarm unit 21, one or more control units 22, a monocular camera 23, and a turning state detection unit 24.

The warning unit 21 issues a warning to the driver of the lean vehicle 1. The control unit 22 predicts the course of the lean vehicle 1, i.e., the vehicle itself, and detects the positions of objects around the vehicle. The control unit 22 calculates the possibility of a collision using the results of the prediction of the vehicle's course and the results of the detection of the positions of objects around the vehicle. The control unit 22 executes warning control, which controls whether or not the warning unit 21 issues a warning and the timing of issuing the warning, based on the possibility of a collision.

As shown within the dashed line frame in Figure 1, the FCW device 2 performs FCW control, including vehicle path prediction, position detection of objects around the vehicle, and warning control.

A monocular camera 23 fixed to the body of the lean vehicle 1 captures images of the vehicle periphery including the area in front of the lean vehicle 1. The control unit 22 acquires the captured image captured by the monocular camera 23 (A). The turning state detection unit 24 detects a physical quantity related to the yaw rate of the body of the lean vehicle 1. The control unit 22 acquires the yaw rate based on the physical quantity detected by the turning state detection unit 24 (B).

The control unit 22 detects the positions of objects around the vehicle based on the captured image (C). The control unit 22 predicts the vehicle's path taking into account the yaw rate (D). Using the results obtained by detecting the positions of objects around the vehicle and the results obtained by predicting the vehicle's path, the control unit 22 performs warning control so that the warning unit 21 issues a warning in situations 1 and 2 shown in FIG. 1 (E).

Situations 1 and 2 shown in FIG. 1 show the positional relationship seen from above between the lean vehicle 1 while traveling and the preceding vehicles 101, 102 detected by detecting the positions of objects around the vehicle. The dashed and dotted lines shown in Situations 1 and 2 are the predicted path of the lean vehicle 1 obtained by executing vehicle path prediction. The dashed and dotted lines are the path of the lean vehicle 1 obtained by executing vehicle path prediction. The dashed lines are the paths that both ends of the lean vehicle 1 in the vehicle width direction will take when the lean vehicle 1 travels along the obtained path. If there is an object within the band indicated by the two dashed lines, there is a possibility that the lean vehicle 1 will collide with this object while continuing to travel. For this reason, warning control is executed using the band indicated by the dashed lines as the predicted path.

In situation 1, while the lean vehicle 1 is turning on a road without white lines, the first leading vehicle 101 is turning with the same turning radius as the lean vehicle 1 and at a vehicle speed V2 that is slower than the vehicle speed V1 of the lean vehicle 1 (V2<V1). The first leading vehicle 101 is turning in front of the lean vehicle 1. The first leading vehicle 101 is turning on the predicted path of the lean vehicle 1.

In situation 1, the control unit 22 executes warning control so that the warning unit 21 issues a warning when the possibility of collision between the lean vehicle 1 and the first leading vehicle 101 becomes equal to or greater than a predetermined collision possibility. For example, the control unit 22 controls the warning unit 21 to issue a warning when the distance between the lean vehicle 1 and the first leading vehicle 101 becomes a predetermined distance. For example, the control unit 22 controls the warning unit 21 to issue a warning when the relative speed between the lean vehicle 1 and the first leading vehicle 101 becomes a predetermined speed. For example, the control unit 22 controls the warning unit 21 to issue a warning when the collision margin time becomes a predetermined time.

In situation 2, the lean vehicle 1 is traveling straight on a road without white lines at the same vehicle speed V1 as in situation 1, while the second leading vehicle 102 is traveling straight ahead of the vehicle at a vehicle speed V2 slower than the vehicle's own speed (V2<V1). Although the lean vehicle 1 is traveling straight, the vehicle is in a meandering state in which the center position of the vehicle width of the front wheels meanders within a range that falls within the vehicle width W of the lean vehicle 1, centered on a straight line parallel to the traveling direction of the second leading vehicle 102 traveling straight. Furthermore, the lean vehicle 1 is traveling such that the center position of the vehicle width of the front wheels of the own vehicle is located within the vehicle width of the second leading vehicle 102 when viewed from the traveling direction of the second leading vehicle 102.

In situation 2, the control unit 22 executes warning control so that the warning unit 21 issues a warning when the probability of a collision between the lean vehicle 1 and the second leading vehicle 102 reaches or exceeds a predetermined probability of collision. As in situation 1, the warning control is performed based on either the distance between the lean vehicle 1 and the first leading vehicle 101, the relative speed between the lean vehicle 1 and the first leading vehicle 101, or the time to collision.

When the lean vehicle 1 moves straight while meandering, as in situation 2, the yaw rate of the lean vehicle 1 may be greater than when moving straight. If vehicle path prediction is performed based on the yaw rate obtained at this time, a predicted path 200 that is curved similar to when turning in situation 1 is obtained, as shown in the diagram of situation 2, for example. If warning control is performed based on this predicted path 200, the second leading vehicle 102 is deemed not to be on the predicted path, and there is a risk that the second leading vehicle will be excluded from the warning target. The control unit 22 avoids this by distinguishing between a turning lean vehicle 1 and a lean vehicle 1 moving straight while meandering.

The control unit 22 determines whether the lean vehicle 1 has started to turn or has become swaying while traveling straight. If it is determined that the lean vehicle 1 has become swaying while traveling straight and has become swaying, the control unit 22 can execute warning control without using the predicted path 200 at the time of the turning determination. The method of determining the swaying state will be described later.

In this way, the FCW device 2 predicts the path of the turning lean vehicle 1 and controls the alarm unit 21 to issue an alarm when the possibility of a collision with an object on the predicted path becomes a predetermined collision possibility. If the lean vehicle 1 traveling straight starts to meander, the FCW device 2 can determine that the lean vehicle 1 traveling straight is in a meandering state and execute alarm control in the same way as when traveling straight. Situation 1 and situation 2 are examples to illustrate this, and the alarm control by the FCW device 2 is not limited to situation 1 and situation 2. For example, even when the first leading vehicle 101 in situation 1 is stopped on the road, alarm control is executed in the same way as in situation 1 described above. For example, even when the second leading vehicle 102 in situation 2 is stopped on the road, alarm control is executed in the same way as in situation 2 described above. The FCW device 2 can execute alarm control in various other situations as well, based on the path of the lean vehicle 1 predicted by executing the host vehicle path prediction, the position of the object detected by the position detection of the object around the host vehicle, and the relative movement between the lean vehicle 1 and the object.

[Second embodiment]
A lean vehicle FCW device 2 according to a second embodiment of the present disclosure will be described with reference to Fig. 2. Below, the contents that overlap with the description of the first embodiment will be omitted, and only the contents necessary for describing the FCW device 2 of the second embodiment will be described.

The FCW device 2 according to the second embodiment has the same configuration as the FCW device 2 according to the first embodiment. The control unit 22 executes host vehicle trajectory prediction and host vehicle peripheral object position detection as described in the first embodiment. Using the results obtained by executing host vehicle peripheral object position detection and the results obtained by executing host vehicle trajectory prediction, the control unit 22 executes warning control so that the warning unit 21 does not issue a warning in situation 3 shown in FIG. 2(a).

In situation 3, lean vehicle 1 is traveling straight ahead at vehicle speed V1 on a road without white lines, while third leading vehicle 103 is traveling straight ahead of lean vehicle 1 at the same vehicle speed V1 as lean vehicle 1. Although lean vehicle 1 is traveling straight, it is in a meandering state where the center position of the vehicle width of its front wheels meanders within a range that falls within the vehicle width of lean vehicle 1, centered on a straight line parallel to the traveling direction of third leading vehicle 103, which is traveling straight. Furthermore, lean vehicle 1 is traveling in such a way that the center position of the vehicle width of its own vehicle's front wheels is located within the vehicle width of third leading vehicle 103 when viewed from the traveling direction of third leading vehicle 103.

In situation 3, in addition to the third leading vehicle 103, a fourth leading vehicle 104 is also traveling at a vehicle speed V2 that is slower than the vehicle speed V1 of the lean vehicle 1 (V2<V1). The fourth leading vehicle 104 is turning ahead of the predicted path 200. The predicted path 200 shows the path obtained when the FCW device 2 performs a host vehicle path prediction for turning at the same yaw rate as the yaw rate obtained for the lean vehicle 1 that is swerving. In reality, when the lean vehicle 1 is in a swerving state, a host vehicle path prediction based on yaw rate is not performed.

When the lean vehicle 1 is in a meandering state, the control unit 22 assumes that the lean vehicle 1 is traveling straight and performs vehicle path prediction. Therefore, the predicted path of the lean vehicle 1 is a strip-shaped area that extends in the same direction as the traveling direction of the third leading vehicle 103 that is traveling straight.

In situation 3, the control unit 22 executes warning control so that the warning unit 21 does not issue a warning. The fourth leading vehicle 104, traveling at a vehicle speed V2 slower than the vehicle speed V1 of the lean vehicle 1, moves relatively toward the lean vehicle 1, but the fourth leading vehicle 104 is located outside the predicted path of the lean vehicle 1, which is considered to be traveling straight. As a result, the possibility of a collision between the lean vehicle 1 and the fourth leading vehicle 104 is below a predetermined collision possibility that requires a warning, and the control unit 22 controls the warning unit 21 so as not to issue a warning for the fourth leading vehicle 104.

The third leading vehicle 103 is on the predicted path of the lean vehicle 1, which is deemed to be traveling straight, but is traveling at the same vehicle speed V1 as the lean vehicle 1. The distance between the lean vehicle 1 and the third leading vehicle 103 is maintained, and the third leading vehicle 103 is not moving relative to the lean vehicle 1. As a result, the probability of a collision between the lean vehicle 1 and the third leading vehicle 103 is also below a predetermined probability of collision that requires an alarm, and the control unit 22 controls the alarm unit 21 not to issue an alarm targeted at the third leading vehicle 103.

FIG. 2(b) shows a situation where the fifth leading vehicle 105 is traveling straight at a vehicle speed V2 on the predicted path of the lean vehicle 1 which is traveling straight at a vehicle speed V1. If the vehicle speed V2 of the fifth leading vehicle 105 is slower than the vehicle speed of the lean vehicle 1 (V2<V1), the control unit 22 executes warning control so that the warning unit 21 issues a warning when the possibility of a collision between the lean vehicle 1 and the fifth leading vehicle 105 reaches or exceeds a predetermined collision possibility. If the vehicle speed V2 of the fifth leading vehicle 105 is the same as the vehicle speed of the lean vehicle 1 (V2=V1), the distance between the lean vehicle 1 and the fifth leading vehicle 105 is maintained, so the control unit 22 executes warning control so that the warning unit 21 does not issue a warning.

In situation 2 shown in FIG. 1 and situation 3 shown in FIG. 2(a), the control unit 22 determines that the lean vehicle 1 is not turning, and therefore executes warning control in the same manner as when the lean vehicle 1 is traveling straight without meandering, as shown in FIG. 2(b).

[Third embodiment]
A lean vehicle FCW device 2 according to a third embodiment of the present disclosure will be described with reference to Fig. 3. Below, the contents that overlap with the descriptions of the first and second embodiments will be omitted, and only the contents necessary for describing the FCW device 2 of the third embodiment will be described.

As shown in FIG. 3(a), the FCW device 2 according to the third embodiment includes, in addition to the configuration shown in FIG. 1, a vehicle speed detection unit 25 that detects the vehicle speed of the lean vehicle 1.

The control unit 22 determines whether the lean vehicle 1 is moving straight or turning from the yaw rate obtained using the turning state detection unit 24. The control unit 22 determines whether the lean vehicle 1 is moving straight or turning from the yaw rate obtained using the turning state detection unit 24. The control unit 22 may determine that the lean vehicle 1 is turning when the magnitude of the yaw rate is equal to or greater than a predetermined threshold. If the yaw rate is defined as positive when the lean vehicle 1 turns to the right relative to the traveling direction and as negative when the lean vehicle 1 turns to the left relative to the traveling direction, the control unit 22 may determine that the lean vehicle 1 is turning when the duration of the sign of the yaw rate is equal to or greater than a predetermined threshold. If it is determined that the lean vehicle 1 is moving straight, the control unit 22 predicts a course ahead in the traveling direction of the lean vehicle 1.

As shown in FIG. 3(b), when the control unit 22 determines that the lean vehicle 1 is turning, it performs a vehicle trajectory prediction that takes into account the turning of the lean vehicle 1, based on the yaw rate obtained using the turning state detection unit 24 and the vehicle speed detected by the vehicle speed detection unit 25 (S1).

When the lean vehicle 1 turns, a curved predicted path is obtained ahead of the turning direction of the lean vehicle 1, as shown in situation 1 of Figure 1. When the lean vehicle 1 travels straight, a straight predicted path is obtained ahead of the traveling direction of the lean vehicle 1, as shown in Figure 2 (b).

When the lean vehicle 1 is in a meandering state, the control unit 22 performs a host vehicle path prediction that takes the meandering state into consideration (S2). Specifically, the control unit 22 performs a host vehicle path prediction when it is determined that the lean vehicle 1 is traveling straight. That is, the control unit 22 performs a host vehicle path prediction regardless of the value of the yaw rate obtained using the turning state detection unit 24. For example, even if a yaw rate having a value similar to that at the start of turning is obtained, the control unit 22 regards the value of the yaw rate as 0 (zero) and performs a host vehicle path prediction. As a result, when the lean vehicle 1 traveling straight is in a meandering state, the same predicted path as when the lean vehicle 1 is traveling straight is obtained.

The control unit 22 executes position detection of objects around the host vehicle based on the captured image obtained by the monocular camera 23 (S3). When the lean vehicle 1 is in a meandering state, the control unit 22 executes warning control based on the predicted path obtained by the host vehicle path prediction (S2) taking into account the meandering state and the position of the object detected by the position detection of the object around the host vehicle (S3) (S4). On the other hand, when the lean vehicle 1 is not in a meandering state and is not traveling straight, the control unit 22 executes warning control based on the predicted path obtained by the host vehicle path prediction (S1) taking into account turning and the position of the object detected by the position detection of the object around the host vehicle (S3) (S4).

[Method of determining meandering state]
An example of a process in which the FCW device 2 for a lean vehicle according to the first to third embodiments determines whether the lean vehicle 1 has started to turn or has started to wobble while traveling straight will be described with reference to FIG.

Figure 4(a) is a diagram showing the change over time in the value of the yaw rate obtained from the detection results of the turning state detection unit 24. Figure 4(a) shows the change in yaw rate when the yaw rate is defined as positive when the lean vehicle 1 turns to the right relative to the traveling direction, and as negative when the yaw rate is defined as negative when the lean vehicle 1 turns to the left relative to the traveling direction.

FIG. 4(b) shows the code duration, which is the duration during which the yaw rate shown in FIG. 4(a) continues to show the same code. The threshold value Th shown in FIG. 4(b) is a threshold value for determining whether the lean vehicle 1 is traveling straight or turning. If the code duration is smaller than the threshold value Th, the control unit 22 determines that the lean vehicle 1 is traveling straight.

Figure 4 (c) shows the straight-line flag that indicates whether the lean vehicle 1 is traveling straight or not. When the lean vehicle 1 is traveling straight, the value of the straight-line flag is "1." When the lean vehicle 1 is turning, the value of the straight-line flag is "0."

If the code duration shown in FIG. 4(b) does not exceed the threshold value Th, the control unit 22 determines that the lean vehicle 1 is traveling straight and sets the straight-line flag to "1" as shown in FIG. 4(c). If the code duration exceeds the threshold value Th, the control unit 22 determines that the lean vehicle 1 is turning and sets the straight-line flag to "0."

If the duration of the yaw rate sign is less than a predetermined threshold value Th, the control unit 22 assumes that the lean vehicle 1 is moving straight ahead and performs vehicle path prediction without considering the yaw rate. For example, as described above, regardless of the value of the yaw rate detected from the lean vehicle 1, the vehicle path prediction is performed with the yaw rate value set to 0 (zero).

In the example shown in FIG. 4, the sign of the yaw rate is positive from time 0 to t1, negative from time t1 to t2, and positive again from time t2 onwards. When the lean vehicle 1 is in a swerving state, the sign of the yaw rate changes in this manner within a short period of time. The threshold value Th is set to a value greater than the sign duration when the vehicle is in this swerving state. When the lean vehicle 1 is in a swerving state, the sign duration does not exceed the threshold value, and the lean vehicle 1 is therefore considered to be traveling straight.

When the lean vehicle 1 starts turning, the code duration becomes longer than when it is in a snaking state. In the example shown in FIG. 4, the code duration reaches the threshold value Th at time t3. When the code duration exceeds the threshold value Th, i.e., a predetermined time, the lean vehicle 1 is considered to be turning.

In this way, even if the lean vehicle 1 starts to sway and meander while traveling straight and the yaw rate shows a large value that cannot be obtained while traveling straight, the control unit 22 can determine whether the lean vehicle 1 has started to turn or is swaying and meandering while traveling straight, based on whether the time during which the yaw rate continues to show the same sign exceeds the threshold value Th.

1 Lean vehicle 2 FCW device 21 Alarm unit 22 Control unit 23 Monocular camera 24 Turning state detection unit 25 Vehicle speed detection unit

Claims (8)

an alarm unit that issues an alarm to a driver;
one or more control units that execute a host vehicle path prediction for predicting a path of the host vehicle and a host vehicle peripheral object position detection for detecting positions of objects around the host vehicle, calculate a collision possibility between the host vehicle and the object using a result of the host vehicle path prediction and a result of the host vehicle peripheral object position detection, and execute a warning control that controls whether or not the warning unit issues a warning based on the collision possibility,
A lean vehicle FCW device used in a lean vehicle in which a vehicle body tilts toward the inside of a turn during a turn,
a monocular camera fixed to the host vehicle and configured to capture an image of the surroundings of the host vehicle;
A turning state detection unit detects a physical quantity related to a yaw rate of the host vehicle,
The control unit is
This FCW device for a lean vehicle is characterized in that it detects the position of objects around the vehicle based on an image captured by the monocular camera, and predicts the vehicle's path taking into account the yaw rate of the vehicle obtained from the detection result of the turning state detection unit, and uses the obtained results to execute the warning control as described in each of the following situations.
Situation 1: When the host vehicle is turning on a road without white lines and a first preceding vehicle is turning in front of the host vehicle at a speed slower than the host vehicle's speed and with the same turning radius as the host vehicle, the control unit executes warning control so that the warning unit issues a warning when the possibility of a collision between the host vehicle and the first preceding vehicle reaches or exceeds a predetermined collision possibility.
Situation 2: When the host vehicle is traveling straight on a road without white lines, a second leading vehicle is traveling straight in front of the host vehicle at a speed slower than the host vehicle's speed, and the center position of the vehicle width direction of the front wheels of the host vehicle is in a zigzag state, zigzagging within a range that falls within the vehicle width of the host vehicle, centered on a straight line parallel to the direction of travel of the second leading vehicle, and the center position of the vehicle width direction of the front wheels of the host vehicle is located within the vehicle width of the second leading vehicle when viewed from the direction of travel of the second leading vehicle, the control unit executes warning control so that the warning unit issues a warning when the possibility of a collision between the host vehicle and the second leading vehicle reaches a predetermined collision possibility or greater. 2. The FCW device for a lean vehicle according to claim 1, wherein the control unit executes the warning control in the following situations:
Situation 3: When the host vehicle is traveling straight on a road without white lines, a third leading vehicle is traveling straight ahead of the host vehicle at the same speed as the host vehicle, the host vehicle is in a serpentine state in which the center position of the vehicle width of the front wheels of the host vehicle is centered on a straight line parallel to the direction of travel of the third leading vehicle and falls within the vehicle width of the host vehicle, the center position of the vehicle width of the front wheels of the host vehicle is located within the vehicle width of the third leading vehicle when viewed from the direction of travel of the third leading vehicle, and a fourth leading vehicle is turning at a speed slower than the speed of the host vehicle, following a turning path predicted from the yaw rate generated by the host vehicle while traveling straight in the serpentine state, the control unit executes warning control so that the warning unit does not issue a warning. A vehicle speed detection unit is further provided to detect the speed of the host vehicle.
The control unit is
determining whether or not the host vehicle is turning based on a yaw rate obtained from the detection result of the turning state detection unit, and when it is determined that the host vehicle is turning, executing the host vehicle path prediction based on the yaw rate obtained from the detection result of the turning state detection unit and the vehicle speed detected by the vehicle speed detection unit;
2. The FCW device for a lean vehicle according to claim 1, characterized in that when the vehicle is in the meandering state, the vehicle is assumed to be traveling straight regardless of the value of the yaw rate, and the vehicle path prediction is performed. The control unit is
When the yaw rate when the host vehicle turns to the right with respect to the traveling direction is defined as positive, and the yaw rate when the host vehicle turns to the left with respect to the traveling direction is defined as negative,
2. The FCW device for a lean vehicle according to claim 1, characterized in that if the duration for which the sign of the yaw rate obtained from the detection result of the turning state detection unit continues to show the same sign is shorter than a predetermined threshold time, the vehicle is deemed to be traveling straight regardless of the value of the yaw rate, and the vehicle path prediction is performed. An FCW method for a lean vehicle, which is executed by an FCW device used in a lean vehicle whose body leans toward the inside of a turn when turning, comprising: a warning unit that issues a warning to a driver; and one or more control units that execute a host vehicle path prediction that predicts a path of the host vehicle and a host vehicle peripheral object position detection that detects the positions of objects around the host vehicle, calculate a collision possibility between the host vehicle and the object using a result of the host vehicle path prediction and a result of the host vehicle peripheral object position detection, and execute warning control that controls whether or not a warning is issued by the warning unit based on the collision possibility,
capturing an image of the surroundings of the host vehicle using a monocular camera fixed to the host vehicle;
acquiring an image captured by the monocular camera and detecting the positions of objects around the host vehicle;
acquiring a yaw rate of the host vehicle from a detection result of a turning state detection unit that detects a physical quantity related to a yaw rate of the host vehicle;
A step of predicting a course of the vehicle taking into consideration a yaw rate obtained from a detection result of the turning state detection unit;
A method for FCW of a lean vehicle, comprising: a step of executing the warning control as described in each of the following situations using the result of the vehicle path prediction and the result of the position detection of the object around the vehicle.
Situation 1: When the host vehicle is turning on a road without white lines and a first preceding vehicle is turning in front of the host vehicle at a speed slower than the host vehicle's speed and with the same turning radius as the host vehicle, the control unit executes the warning control so that the warning unit issues a warning when the possibility of a collision between the host vehicle and the first preceding vehicle reaches or exceeds a predetermined collision possibility.
Situation 2: When the host vehicle is traveling straight on a road without white lines, a second leading vehicle is traveling straight in front of the host vehicle at a speed slower than the host vehicle's speed, and the center position of the vehicle width direction of the front wheels of the host vehicle is in a zigzag state, zigzagging within a range that falls within the vehicle width of the host vehicle, centered on a straight line parallel to the direction of travel of the second leading vehicle, and the center position of the vehicle width direction of the front wheels of the host vehicle is located within the vehicle width of the second leading vehicle when viewed from the direction of travel of the second leading vehicle, the control unit executes the warning control so that the warning unit issues a warning when the possibility of a collision between the host vehicle and the second leading vehicle reaches a predetermined collision possibility or greater. 6. The lean vehicle FCW method of claim 5, further comprising the step of: executing the warning control as described in the following circumstances:
Situation 3: When the host vehicle is traveling straight on a road without white lines, a third leading vehicle is traveling straight ahead of the host vehicle at the same speed as the host vehicle, the host vehicle is in a serpentine state in which the center position of the vehicle width of the front wheels of the host vehicle is centered on a straight line parallel to the direction of travel of the third leading vehicle and falls within the vehicle width of the host vehicle, the center position of the vehicle width of the front wheels of the host vehicle is located within the vehicle width of the third leading vehicle when viewed from the direction of travel of the third leading vehicle, and a fourth leading vehicle is turning at a speed slower than the speed of the host vehicle, following a turning path predicted from the yaw rate generated by the host vehicle while traveling straight in the serpentine state, the control unit executes the warning control so that the warning unit does not issue a warning. It is determined whether or not the host vehicle is turning based on a yaw rate obtained from the detection result of the turning state detection unit, and when it is determined that the host vehicle is turning, the host vehicle path prediction is executed based on the yaw rate obtained from the detection result of the turning state detection unit and a vehicle speed detected by a vehicle speed detection unit that detects the vehicle speed of the host vehicle,
The FCW method for lean vehicles as described in claim 5, characterized in that when the vehicle is in the swerving state, the vehicle path prediction is performed assuming that the vehicle is traveling straight, regardless of the value of the yaw rate. 6. The FCW method for a lean vehicle as described in claim 5, characterized in that, when the yaw rate when the vehicle turns to the right with respect to the traveling direction is defined as positive, and the yaw rate when the vehicle turns to the left with respect to the traveling direction is defined as negative, if the duration during which the sign of the yaw rate obtained from the detection result of the turning state detection unit continues to show the same sign is shorter than a predetermined threshold time, the vehicle path prediction is performed assuming that the vehicle is traveling straight, regardless of the value of the yaw rate.

Images