JP7543359B2 - Driving assistance system for saddle-type vehicles - Google Patents

Description

The present invention relates to a driving assistance system for a saddle-type vehicle. More specifically, the present invention relates to a driving assistance system for a saddle-type vehicle that is equipped with a vehicle speed detection means and an inertia detection means.

In recent years, many motorcycles have been proposed that are equipped with inertial measurement units to grasp the posture of the vehicle body while it is moving (see, for example, Patent Document 1). An inertial measurement unit is composed of a combination of acceleration sensors and gyros that detect the acceleration along each of the three axes that govern the movement of the vehicle body and the angular acceleration around each axis. In such motorcycles, by feeding back information obtained by the inertial measurement unit to a control device that controls the engine and vehicle behavior, it becomes possible to perform traction control and suspension control according to the posture of the vehicle body.

JP 2015-189300 A

As shown in Figure 6, a rider of a motorcycle V1 may inadvertently overtake a leading vehicle V2 without activating a turn signal. In this case, however, the driver of a following vehicle V3 traveling behind the motorcycle V1 may be slow to recognize that the motorcycle V1 is suddenly changing direction, which may result in an accident.

The present invention aims to provide a driving assistance system for saddle-type vehicles that can improve traffic safety by preventing accidents between a saddle-type vehicle that is changing direction of travel and surrounding traffic participants.

(1) A driving assistance system for a saddle-type vehicle according to the present invention (e.g., driving assistance system 1 described below) includes a direction indicator (e.g., direction indicators 6L and 6R described below) provided on the body of the saddle-type vehicle, a vehicle speed detection means (e.g., vehicle speed sensor 2 described below) that detects the vehicle speed of the vehicle body, an inertia detection means (e.g., inertial measurement device 3 described below) that detects axial acceleration along each of three axes defined for the vehicle body and axial angular velocity around each axis, and a vehicle speed detection value by the vehicle speed detection means, an axial acceleration detection value by the inertia detection means, and an axial angular velocity detection value by the inertia detection means. The vehicle is characterized by having a direction-changing behavior detection means (e.g., a direction-changing behavior detection unit 81 described below) that detects the direction-changing behavior of the vehicle body based on the detected angle and the detected shaft angular velocity, and a notification means (e.g., a direction indicator control unit 82, direction indicators 6L and 6R, inter-vehicle communication control unit 83, and in-vehicle communication device 5 described below) that notifies surrounding traffic participants around the vehicle body of the direction of travel of the vehicle body when the direction-changing behavior is detected while the direction indicator is not operating.

(2) In this case, it is preferable that the traveling direction change behavior detection means includes a steering angle estimation unit (e.g., steering angle estimation unit 812 described below) that calculates a steering angle estimate value of the vehicle body based on the vehicle speed detection value, the axial acceleration detection value, and the axial angular velocity detection value, and a behavior detection unit (e.g., behavior detection unit 814 described below) that detects the traveling direction change behavior based on the steering angle estimate value.

(3) In this case, the traveling direction change behavior detection means preferably further includes a rider applied torque estimation unit (e.g., a rider applied torque estimation unit 813 described below) that calculates a rider applied torque estimate generated by the movement of the center of gravity of the rider straddling the vehicle body based on the vehicle speed detection value, the axial acceleration detection value, and the axial angular velocity detection value, and the behavior detection unit preferably detects the traveling direction change behavior based on the steering angle estimation value and the rider applied torque estimation value.

(4) In this case, it is preferable that the notification means notifies the surrounding traffic participants of the traveling direction by activating the direction indicator.

(5) In this case, it is preferable that the notification means notifies the surrounding traffic participants of the traveling direction by transmitting information about the traveling direction to an in-vehicle communication device traveling together with the surrounding traffic participants.

(6) In this case, it is preferable that the driving assistance system further includes a notification means (e.g., a notification control unit 84 and an HMI 7 described below) that notifies the rider when the absolute value of the rider-applied torque estimate exceeds a predetermined limit value.

(1) In the driving assistance system for a saddle-type vehicle according to the present invention, the direction-changing behavior detection means detects the direction-changing behavior of the body of the saddle-type vehicle based on the vehicle speed detection value, the axial acceleration detection value, and the axial angular velocity detection value, and the notification means notifies surrounding traffic participants of the direction of travel of the body when the direction-changing behavior is detected with the turn indicator not activated. This allows surrounding traffic participants to quickly recognize the presence of the saddle-type vehicle changing its direction of travel, even if the rider changes the direction of travel of the body without activating the turn indicator, thereby preventing accidents between the saddle-type vehicle changing its direction of travel and surrounding traffic participants, and ultimately improving traffic safety.

(2) The traveling direction change behavior detection means includes a steering angle estimation unit that calculates an estimated steering angle of the vehicle body based on the vehicle speed detection value, the axial acceleration detection value, and the axial angular velocity detection value, and a behavior detection unit that detects the traveling direction change behavior based on the steering angle estimation value. Therefore, according to the present invention, the traveling direction change behavior of the vehicle body can be detected quickly, so that surrounding traffic participants can more quickly recognize the presence of a saddle-type vehicle that is changing its traveling direction, thereby improving traffic safety.

(3) The direction-changing behavior detection means further includes a rider-applied torque estimation unit that calculates an estimated rider-applied torque caused by the movement of the center of gravity of the rider straddling the vehicle body based on the vehicle speed detection value, the axial acceleration detection value, and the axial angular velocity detection value. Thus, according to the present invention, the behavior detection unit detects the direction-changing behavior based on the steering angle estimation value and the rider-applied torque estimation value, thereby enabling the detection of the direction-changing behavior to be more quickly and accurately, thereby improving traffic safety.

(4) In the present invention, when a direction-changing behavior is detected with the turn indicator not in operation, the notification means notifies surrounding traffic participants of the direction of travel of the vehicle by activating the turn indicator. Thus, according to the present invention, it is possible to notify surrounding traffic participants of the direction of travel of the vehicle with a simple configuration, thereby improving traffic safety.

(5) In the present invention, when a direction-changing behavior is detected with the direction indicator not in operation, the notification means notifies the surrounding traffic participants of the direction of travel of the vehicle by transmitting information about the direction of travel to an in-vehicle communication device traveling with the surrounding traffic participants. Thus, according to the present invention, the surrounding traffic participants can quickly recognize the presence of a saddle-type vehicle that appears from a position that cannot be seen with the naked eye, thereby improving traffic safety.

(6) When the absolute value of the rider applied torque estimate exceeds a predetermined limit value, i.e., when the rider is attempting to change the direction of travel of the vehicle body by excessively shifting the center of gravity, the notification means can notify the rider, thereby preventing a fall and thereby improving traffic safety.

1 is a diagram showing a configuration of a driving assistance system according to an embodiment of the present invention; FIG. 2 is a functional block diagram showing a configuration of a traveling direction changing behavior detection unit. FIG. 2 is a side view of the motorcycle at rest in a straight-ahead position. FIG. 2 is a diagram illustrating a two-mass model. FIG. 2 is a diagram showing the configuration of a control circuit of a lidar applied external force observer. FIG. 2 is a diagram showing a schematic diagram of the movement paths of a motorcycle and a following vehicle when overtaking;

The following describes a driving assistance system according to one embodiment of the present invention with reference to the drawings.

Figure 1 is a diagram showing the configuration of a driving assistance system 1 according to this embodiment. This driving assistance system 1 is mounted on a motorcycle (not shown) as a saddle-type vehicle. The drive source of this motorcycle may be an internal combustion engine, a rotating electric machine, or a combination of these. The power source of the rotating electric machine may be a secondary battery, a capacitor, or a fuel cell. The following describes the application of the driving assistance system 1 to a motorcycle, but the present invention is not limited to this. In addition to motorcycles, the present invention can be applied to saddle-type vehicles such as saddle-type three-wheeled vehicles, saddle-type four-wheeled vehicles, and motorized bicycles.

The driving assistance system 1 assists the rider in driving a motorcycle safely. Among the various driving assistance functions realized by the driving assistance system 1, the following describes a driving direction notification function that notifies surrounding traffic participants around the vehicle of the direction of travel of the vehicle body.

The driving assistance system 1 includes a vehicle speed sensor 2, an inertial measurement unit 3, turn signal switches 4L, 4R, an in-vehicle communication unit 5, turn signals 6L, 6R, a human machine interface 7 (hereinafter abbreviated as "HMI7"), and a driving assistance control unit 8.

The vehicle speed sensor 2 detects the travel speed of the vehicle body in the traveling direction (hereinafter referred to as "vehicle speed") and transmits a signal corresponding to the vehicle speed detection value to the driving assistance control device 8. For this vehicle speed sensor 2, for example, a rotary encoder that outputs a signal corresponding to the rotation speed of the rear wheels (not shown) is used.

The inertial measurement unit 3 includes multiple acceleration sensors that detect axial acceleration along each of the three axes (x-axis, y-axis, and z-axis) in an xyz Cartesian coordinate system (hereinafter, local coordinate system) defined with respect to the vehicle body, multiple angular velocity sensors that detect axial angular velocity around each axis, and a housing that houses these acceleration sensors and angular velocity sensors.

The inertial measurement unit 3 is attached to an arbitrary position of the vehicle body. In the following, the axis extending along the straight direction of the vehicle body (i.e., the front-rear direction of the vehicle body) is the x-axis in the local coordinate system, the axis extending along the vehicle width direction of the vehicle body is the y-axis in the local coordinate system, and the axis extending along the vertical direction of the vehicle body is the z-axis, but the present invention is not limited to this. In addition, in the following, the acceleration of the vehicle body along the x-axis, y-axis, and z-axis in the local coordinate system are referred to as the x-axis acceleration, y-axis acceleration, and z-axis acceleration, and the angular velocity of the vehicle body around the x-axis, y-axis, and z-axis are referred to as the x-axis angular velocity, y-axis angular velocity, and z-axis angular velocity. The inertial measurement unit 3 detects the x-axis acceleration, y-axis acceleration, z-axis acceleration, x-axis angular velocity, y-axis angular velocity, and z-axis angular velocity by using multiple acceleration sensors and multiple angular velocity sensors, and transmits signals corresponding to these detection values to the driving assistance control device 8.

The left turn indicator switch 4L and the right turn indicator switch 4R are controls that the rider can operate to inform surrounding traffic participants (hereinafter also referred to as "surrounding traffic participants"), such as oncoming vehicles and following vehicles, of the vehicle's traveling direction, and are provided, for example, at the base of the left handlebar grip that the rider holds with his left hand. When the rider turns on the left turn indicator switch 4L, the turn indicator drive circuit (not shown) activates (i.e., blinks) the left turn indicator 6L located on the left side of the vehicle as seen by the rider. When the rider turns on the right turn indicator switch 4R, the turn indicator drive circuit activates (i.e., blinks) the right turn indicator 6R located on the right side of the vehicle as seen by the rider.

The HMI7 is made up of multiple interfaces that present various information to the rider through voice, images, etc., and accept input operations by the rider.

The in-vehicle communication device 5 transmits various information to the in-vehicle communication devices of the surrounding traffic participants by wirelessly communicating with the in-vehicle communication devices of the surrounding traffic participants.

The driving assistance control device 8 is a computer that is responsible for controlling the driving assistance functions. The driving assistance control device 8 includes a direction change behavior detection unit 81, a turn indicator control unit 82, a vehicle-to-vehicle communication control unit 83, and a notification control unit 84 as modules that realize the driving direction notification function, which is one of the multiple driving assistance functions.

The traveling direction change behavior detection unit 81 detects the traveling direction change behavior of the vehicle body based on the vehicle speed detection value, the x-axis, y-axis, and z-axis acceleration detection values (hereinafter, these are also collectively referred to as "each axis acceleration detection value"), and the x-axis, y-axis, and z-axis angular velocity detection values (hereinafter, these are also collectively referred to as "each axis angular velocity detection value"). Here, the traveling direction change behavior refers to the behavior of the vehicle body that occurs when the traveling direction of the vehicle body changes, for example, when changing lanes, turning left, turning right, and overtaking. More specifically, the traveling direction change behavior refers to the behavior of the vehicle body when the traveling direction of the vehicle body in a plan view changes from a state parallel to the straight traveling direction to a state inclined with respect to the straight traveling direction. Hereinafter, the traveling direction change behavior when the traveling direction of the vehicle body changes to the left hand side of the rider with respect to the straight traveling direction is also referred to as the left movement behavior, and the traveling direction change behavior when the traveling direction of the vehicle body changes to the right hand side of the rider with respect to the straight traveling direction is also referred to as the right movement behavior.

Figure 2 is a functional block diagram showing the configuration of the traveling direction change behavior detection unit 81. The traveling direction change behavior detection unit 81 includes a vehicle body state parameter calculation unit 811, a steering angle estimation unit 812, a rider applied torque estimation unit 813, and a behavior detection unit 814, and detects the traveling direction change behavior of the vehicle body by using these.

The vehicle body state parameter calculation unit 811 calculates the values of a plurality of vehicle body state parameters that characterize the current attitude and state of the vehicle body relative to the road surface based on the vehicle speed detection value, the acceleration detection value of each axis, and the angular velocity detection value of each axis. More specifically, the vehicle body state parameter calculation unit 811 defines an orthogonal coordinate system defined based on the road surface as a global coordinate system, and calculates the values of a plurality of vehicle body state parameters defined under this global coordinate system. Here, the X-axis of the global coordinate system is an axis in the same direction as the axis obtained by projecting the x-axis of the local coordinate system onto the road surface, the Y-axis of the global coordinate system is an axis in the same direction as the axis obtained by projecting the y-axis of the local coordinate system onto the road surface, and the Z-axis of the global coordinate system is an axis extending along the vertical direction perpendicular to the road surface. Therefore, when the vehicle body is stationary in a straight-ahead posture, the x-axis, y-axis, and z-axis directions of the local coordinate system respectively coincide with the x-axis, Y-axis, and Z-axis directions of the global coordinate system.

The vehicle body state parameter calculation unit 811 calculates values such as roll angle (tilt angle of the vehicle body about the X-axis as viewed in the global coordinate system), pitch angle (tilt angle of the vehicle body about the Y-axis as viewed in the global coordinate system), yaw angle (rotation angle of the vehicle body about the Z-axis as viewed in the global coordinate system), roll angular velocity (time rate of change of roll angle), pitch angular velocity (time rate of change of pitch angle), yaw angular velocity (time rate of change of yaw angle), and lateral acceleration (acceleration in the Y-axis direction of the vehicle body as viewed in the global coordinate system) as multiple vehicle body state parameters based on the vehicle speed detection value, the acceleration detection value of each axis, and the angular velocity detection value of each axis. The vehicle body state parameter calculation unit 811 calculates values of multiple vehicle body state parameters based on a known method described, for example, in JP 2015-189300 A by the applicant of the present application.

The steering angle estimation unit 812 calculates a steering angle estimate value corresponding to an estimate for the front wheel steering angle of the vehicle body based on the values of the multiple vehicle body state parameters calculated by the vehicle body state parameter calculation unit 811.

FIG. 3 is a side view of a motorcycle stationary in a straight-ahead posture. In FIG. 3, "δf" indicates the front wheel steering angle, and "φ" indicates the roll angle. Also, "θcf" indicates the caster angle, and "L" indicates the wheelbase. In this case, if the vehicle speed is "Vox" and the yaw angular velocity is "ωz", the front wheel steering angle δf can be expressed by the following formula (1) through geometric calculation. Therefore, the steering angle estimation unit 812 calculates the steering angle estimation value based on the following formula (1). At this time, on the right side of the following formula (1), the vehicle speed detection value is used for "Vox", the value of the yaw angular velocity calculated by the vehicle body state parameter calculation unit 811 is used for "ωz", the value of the roll angle calculated by the vehicle body state parameter calculation unit 811 is used for "φ", and predetermined values are used for "L" and "θcf". In the following description, the steering angle estimated value calculated by steering angle estimator 812 based on the following equation (1) is denoted as "δf_hat".

Returning to FIG. 2, the rider applied torque estimation unit 813 calculates a rider applied torque estimate value that corresponds to an estimate value of the rider applied torque generated by the movement of the center of gravity of the rider straddling the vehicle body, based on the steering angle estimate value calculated by the steering angle estimation unit 812 and the values of the multiple vehicle body state parameters calculated by the vehicle body state parameter calculation unit 811.

When calculating the rider applied torque estimate, the rider applied torque estimation unit 813 uses a two-mass point model that represents the behavior of the vehicle body and the rider straddling the vehicle body using two mass points. Details of this two-mass point model are described in, for example, JP 2014-91386 A by the applicant of the present application, so only a brief explanation will be given here.

Figure 4 is a diagram showing a two-mass model. As shown in Figure 4, the two-mass model is composed of an inverted pendulum mass point 91, which is a mass point that moves horizontally in the Y-axis direction above the road surface S on which the vehicle body is in contact, in response to the roll angle φ of the vehicle body and the front wheel steering angle δf, and a road surface mass point 92, which is a mass point that moves horizontally in the Y-axis direction above the road surface S in response to the front wheel steering angle δf, independent of the roll angle φ of the vehicle body.

Figure 5 is a diagram showing the configuration of a control circuit for a rider-applied external force observer constructed based on a two-mass point model to estimate the rider-applied torque. The rider-applied torque estimator 813 calculates the rider-applied torque estimate by using a rider-applied external force observer as shown in Figure 5. Note that detailed procedures for calculating estimates of various physical quantities based on the two-mass point model are described in, for example, Japanese Patent Application Publication No. 2016-179710 and Japanese Patent Application Publication No. 2017-7550 by the applicant of the present application, and therefore will only be briefly described here.

In the control circuit shown in FIG. 5, "m1" indicates the mass of the inverted pendulum mass point 91, "h'" corresponds to the height of the inverted pendulum mass point 91 from the road surface S, "K" corresponds to the observer gain, and "1/s" indicates an integral operation. Also, in the control circuit shown in FIG. 5, "φdot" corresponds to the roll angular velocity of the inverted pendulum mass point 91, "τg" corresponds to the moment generated by gravity acting on the inverted pendulum mass point 91, "τs" corresponds to the moment generated in response to the steering of the front wheel, and "τr" corresponds to the rider applied torque generated by the movement of the rider's center of gravity. That is, in the rider applied external force observer shown in FIG. 5, the difference between the roll angular velocity φ_dot_hat predicted from the steering input to the front wheel and the vehicle body overturning force due to gravity and the actual roll angular velocity φ_dot is assumed to be due to the weight shift of the rider, and the rider applied torque estimate value is calculated.

The rider applied torque estimator 813 calculates the rider applied torque estimate by using the rider applied external force observer as described above. At this time, the roll angular velocity value calculated by the vehicle body state parameter calculator 811 is used as the input "φdot" to the rider applied external force observer, and the inputs "τg" and "τs" to the rider applied external force observer are estimated values calculated by performing a predetermined calculation. Here, the estimated values of "τg" and "τs" are values obtained by inputting the values of the multiple vehicle body state parameters calculated by the vehicle body state parameter calculator 811 and the steering angle estimate value calculated by the steering angle estimator 812 into an arithmetic expression not shown. In the following, the rider applied torque estimate calculated by the rider applied torque estimator 813 using the rider applied external force observer shown in FIG. 5 is denoted as "τr_hat".

Returning to FIG. 2, the behavior detection unit 814 detects the traveling direction change behavior of the vehicle body based on the steering angle estimate δf_hat calculated by the steering angle estimation unit 812 and the rider applied torque estimate τr_hat calculated by the rider applied torque estimation unit 813. When the vehicle body is in a straight-line state, that is, when the traveling direction of the vehicle body is approximately parallel to the straight-line direction, the steering angle estimate δf_hat and the rider applied torque estimate τr_hat are both approximately 0. In contrast, when the vehicle body exhibits a leftward movement behavior, the steering angle estimate δf_hat and the rider applied torque estimate τr_hat change to the positive side, and when the vehicle body exhibits a rightward movement behavior, the steering angle estimate δf_hat and the rider applied torque estimate τr_hat change to the negative side.

Therefore, the behavior detection unit 814 detects the leftward movement behavior of the vehicle body when the steering angle estimate δf_hat is greater than the positive steering angle threshold and the rider applied torque estimate τr_hat is greater than the positive torque threshold. The behavior detection unit 814 also detects the rightward movement behavior of the vehicle body when the steering angle estimate δf_hat is less than the negative steering angle threshold and the rider applied torque estimate τr_hat is less than the negative torque threshold.

In this embodiment, the behavior detection unit 814 detects the vehicle body's traveling direction change behavior based on both the steering angle estimate δf_hat and the rider applied torque estimate τr_hat as described above, but the present invention is not limited to this. The behavior detection unit may detect the vehicle body's traveling direction change behavior based only on the steering angle estimate δf_hat. That is, the behavior detection unit may detect the leftward movement behavior of the vehicle body when the steering angle estimate δf_hat is greater than the positive steering angle threshold, and detect the rightward movement behavior of the vehicle body when the steering angle estimate δf_hat is less than the negative steering angle threshold.

In addition, in this embodiment, the behavior detection unit 814 detects the vehicle body's traveling direction change behavior based on a comparison of the steering angle estimate δf_hat and the rider applied torque estimate τr_hat with a predetermined threshold value, but the present invention is not limited to this. The range of change in the steering angle estimate δf_hat and the rider applied torque estimate τr_hat when the vehicle body exhibits a traveling direction change behavior changes depending on the vehicle speed. Therefore, the steering angle threshold for the steering angle estimate δf_hat and the torque threshold for the rider applied torque estimate τr_hat may be changed depending on the vehicle speed.

Returning to FIG. 1, when the direction indicators 6L, 6R are not in operation and the traveling direction change behavior detection unit 81 detects a traveling direction change behavior, the turn indicator control unit 82 activates the direction indicators 6L, 6R to notify surrounding traffic participants of the traveling direction of the vehicle body. More specifically, when the left direction indicator 6L is not in operation and the traveling direction change behavior detection unit 81 detects a leftward movement behavior, the turn indicator control unit 82 activates the left direction indicator 6L to notify surrounding traffic participants that the traveling direction of the vehicle body is to the left. Also, when the right direction indicator 6R is not in operation and the traveling direction change behavior detection unit 81 detects a rightward movement behavior, the turn indicator control unit 82 activates the right direction indicator 6R to notify surrounding traffic participants that the traveling direction of the vehicle body is to the right.

When the direction change behavior detection unit 81 detects a direction change behavior while the direction indicators 6L and 6R are not in operation, the vehicle-to-vehicle communication control unit 83 uses the in-vehicle communication device 5 to transmit information regarding the vehicle's direction of travel to the in-vehicle communication device moving with the surrounding traffic participants, and notifies the surrounding traffic participants of the information regarding the vehicle's direction of travel via the in-vehicle HMI moving with the surrounding traffic participants. More specifically, when the left direction indicator 6L is not in operation and the direction change behavior detection unit 81 detects a leftward movement behavior, the vehicle-to-vehicle communication control unit 83 transmits information indicating that the vehicle's direction of travel is left from the in-vehicle communication device 5 to the in-vehicle communication device of the surrounding traffic participant. Also, when the right direction indicator 6R is not in operation and the direction change behavior detection unit 81 detects a rightward movement behavior, the vehicle-to-vehicle communication control unit 83 transmits information indicating that the vehicle's direction of travel is right from the in-vehicle communication device 5 to the in-vehicle communication device of the surrounding traffic participant.

As described above, in this embodiment, the notification means is composed of the turn indicator control unit 82, the turn indicators 6L and 6R, the vehicle-to-vehicle communication control unit 83, and the in-vehicle communication device 5.

When the absolute value of the rider applied torque estimate τr_hat calculated by the traveling direction change behavior detection unit 81 exceeds a predetermined limit value, that is, when the rider is attempting to change the traveling direction of the vehicle body by an extreme shift in the center of gravity, the notification control unit 84 notifies the rider of a predetermined warning message via the HMI 7. As described above, in this embodiment, the notification means is composed of the notification control unit 84 and the HMI 7.

The driving assistance system 1 according to this embodiment has the following advantages.
(1) In the driving assistance system 1, the direction-changing behavior detection unit 81 detects the direction-changing behavior of the motorcycle body based on the vehicle speed detection value, the acceleration detection value of each axis, and the angular velocity detection value of each axis, and when the direction-changing behavior is detected with the direction indicators 6L, 6R not in operation, the turn indicator control unit 82 and the vehicle-to-vehicle communication control unit 83 notify the surrounding traffic participants of the direction of travel of the vehicle body. This allows the surrounding traffic participants to quickly recognize the presence of the motorcycle changing its direction of travel even if the rider changes the direction of travel of the vehicle body without activating the turn indicators 6L, 6R, thereby preventing accidents between the motorcycle changing its direction of travel and the surrounding traffic participants, and ultimately improving traffic safety.

(2) The direction-changing behavior detection unit 81 includes a steering angle estimation unit 812 that calculates a steering angle estimate δf_hat of the vehicle body based on the vehicle speed detection value, the acceleration detection value of each axis, and the angular velocity detection value of each axis, and a behavior detection unit 814 that detects the direction-changing behavior of the vehicle body based on the steering angle estimate δf_hat. Therefore, according to the driving assistance system 1, the direction-changing behavior of the vehicle body can be detected quickly, so that surrounding traffic participants can more quickly recognize the presence of a motorcycle changing its direction of travel, thereby improving traffic safety.

(3) The direction-changing behavior detection unit 81 further includes a rider-applied torque estimation unit 813 that calculates a rider-applied torque estimate τr_hat generated by the movement of the center of gravity of the rider straddling the vehicle body based on the vehicle speed detection value, the acceleration detection value of each axis, and the angular velocity detection value of each axis. Therefore, according to the driving assistance system 1, the behavior detection unit 814 detects the direction-changing behavior based on the steering angle estimate δf_hat and the rider-applied torque estimate τr_hat, thereby making it possible to detect the direction-changing behavior more quickly and accurately, thereby improving traffic safety.

(4) When a direction change behavior is detected while the direction indicators 6L, 6R are not in operation, the turn indicator control unit 82 activates the turn indicators 6L, 6R to notify surrounding traffic participants of the direction of travel of the vehicle. Thus, according to the driving assistance system 1, it is possible to notify surrounding traffic participants of the direction of travel of the vehicle with a simple configuration, thereby improving traffic safety.

(5) When a direction-changing behavior is detected with the direction indicators 6L, 6R not in operation, the vehicle-to-vehicle communication control unit 83 notifies the surrounding traffic participants of the vehicle's direction of travel by transmitting information about the direction of travel from the in-vehicle communication device 5 to an in-vehicle communication device traveling together with the surrounding traffic participants. Therefore, according to the driving assistance system 1, the surrounding traffic participants can quickly recognize the presence of a motorcycle that appears from a position that cannot be seen with the naked eye, thereby improving traffic safety.

(6) When the absolute value of the rider applied torque estimate τr_hat exceeds a predetermined limit value, i.e., when the rider is attempting to change the direction of travel of the vehicle body by extreme center of gravity shift, the notification control unit 84 can prevent a fall by notifying the rider via the HMI 7, thereby improving traffic safety.

Although one embodiment of the present invention has been described above, the present invention is not limited to this. The detailed configuration may be modified as appropriate within the scope of the spirit of the present invention.

1... Driving assistance system 2... Vehicle speed sensor (vehicle speed detection means)
3... Inertial measurement device (inertial detection means)
5...In-vehicle communication device (notification means)
6L, 6R...Direction indicator (notification means)
7...HMI (notification means)
8... Driving assistance control device 81... Travel direction change behavior detection unit (travel direction change behavior detection means)
811: Vehicle body state parameter calculation unit 812: Steering angle estimation unit (steering angle estimation unit)
813...rider applied torque estimating unit (rider applied torque estimating unit)
814...Behavior detection unit (behavior detection unit)
82... Turn indicator control unit (notification means)
83... Vehicle-to-vehicle communication control unit (notification means)
84...Notification control unit (notification means)

Claims (6)

A direction indicator provided on a body of the saddle-type vehicle;
a vehicle speed detection means for detecting a vehicle speed of the vehicle body;
a vehicle body having an inertia detection means for detecting an axial acceleration along each of three axes and an axial angular velocity around each of the three axes,
a direction-changing behavior detection means for detecting a direction-changing behavior of the vehicle body based on a vehicle speed detection value by the vehicle speed detection means and an axial acceleration detection value and an axial angular velocity detection value by the inertia detection means;
a notification means for notifying surrounding traffic participants around the vehicle body of the traveling direction of the vehicle body when the traveling direction change behavior is detected in a state where the direction indicator is not in operation ,
The traveling direction change behavior detection means
a steering angle estimating unit that calculates an estimated steering angle of the vehicle body based on the vehicle speed detection value, the axial acceleration detection value, and the axial angular velocity detection value;
a behavior detection unit that detects the traveling direction change behavior based on the steering angle estimated value . the traveling direction change behavior detection means further includes a rider applied torque estimator that calculates a rider applied torque estimate value generated by a movement of a center of gravity of a rider straddling the vehicle body, based on the vehicle speed detection value, the axial acceleration detection value, and the axial angular velocity detection value;
2. The driving assistance system for a saddle-type vehicle according to claim 1 , wherein the behavior detection unit detects the traveling direction change behavior based on the steering angle estimate value and the rider-applied torque estimate value. A turn signal provided on a body of the saddle-type vehicle;
a vehicle speed detection means for detecting a vehicle speed of the vehicle body;
a vehicle body having an inertia detection means for detecting an axial acceleration along each of three axes and an axial angular velocity around each of the three axes,
a direction-changing behavior detection means for detecting a direction-changing behavior of the vehicle body based on a vehicle speed detection value by the vehicle speed detection means and an axial acceleration detection value and an axial angular velocity detection value by the inertia detection means;
a notification means for notifying surrounding traffic participants around the vehicle body of the traveling direction of the vehicle body when the traveling direction change behavior is detected in a state where the direction indicator is not in operation,
the traveling direction change behavior detection means includes a rider applied torque estimator that calculates a rider applied torque estimate value generated by a movement of the center of gravity of a rider straddling the vehicle body based on the vehicle speed detection value, the axial acceleration detection value, and the axial angular velocity detection value;
a behavior detection unit that detects the traveling direction change behavior based on the rider applied torque estimate value. The driving support system for a saddle-type vehicle according to any one of claims 1 to 3, characterized in that the notification means notifies the surrounding traffic participants of the traveling direction by activating the direction indicator. The driving assistance system for a saddle-type vehicle according to any one of claims 1 to 3, characterized in that the notification means notifies the surrounding traffic participants of the traveling direction by transmitting information about the traveling direction to an in-vehicle communication device that travels together with the surrounding traffic participants. 4. The driving assistance system for a saddle-type vehicle according to claim 2, further comprising a notification unit that notifies the rider when an absolute value of the rider-applied torque estimate value exceeds a predetermined limit value.

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