Driving assistance system for a straddle-type vehicle

Abstract

Provided is a driving assistance system for a straddle-type vehicle capable of improving traffic safety by preventing accidents between a straddle-type vehicle changing a traveling direction and a surrounding traffic participant. The driving assistance system 1 for a straddle-type vehicle includes: direction indicators 6L, 6R provided on a vehicle body; a vehicle speed sensor 2 that detects a vehicle speed; an inertial measurement device 3 that detects an axial acceleration along each axis of three axes defined with respect to the vehicle body and an axial angular velocity around each axis; a traveling direction change behavior detection section 81 that detects a traveling direction change behavior of the vehicle body based on a vehicle speed detection value of the vehicle speed sensor 2, each axial acceleration detection value, and each axial angular velocity detection value of the inertial measurement device 3; and a direction indicator control section 82 that, when the traveling direction change behavior is detected in a state in which the direction indicators 6L, 6R are not operating, notifies the surrounding traffic participant of the traveling direction of the vehicle body by causing the direction indicators 6L, 6R to operate.

Description

Technical Field

[0001] This invention relates to a driving assistance system for a straddle-type vehicle. More specifically, it relates to a driving assistance system for a straddle-type vehicle that includes a vehicle speed detection method and an inertial detection method. Background Technology

[0002] In recent years, various motorcycles equipped with inertial measurement units (IMUs) have been proposed to monitor the posture of a moving motorcycle (see, for example, Patent Document 1). An IMU is constructed by combining an accelerometer or gyroscope, which detects the acceleration along each of the three axes controlling the motorcycle's motion and the angular acceleration about each axis. In such motorcycles, information obtained from the IMU can be fed back to a control device that controls the engine or motorcycle's behavior, allowing for traction control or suspension control based on the motorcycle's posture.

[0003] [Previous Technical Documents]

[0004] (Patent Documents)

[0005] Patent Document 1: Japanese Patent Application Publication No. 2015-189300 Summary of the Invention

[0006] [The problem the invention aims to solve]

[0007] However, as Figure 6 As shown, the rider of motorcycle V1 may sometimes unintentionally overtake vehicle V2 without activating the turn indicator. However, at this time, the driver of vehicle V3 behind motorcycle V1 will have a delayed recognition of motorcycle V1's sudden change of direction, thus causing an accident.

[0008] The purpose of this invention is to provide a driving assistance system for a straddle-type vehicle that can improve traffic safety by preventing accidents between the straddle-type vehicle changing direction and surrounding road users.

[0009] [Technical means to solve the problem]

[0010] (1) The driving assistance system for a straddle-type vehicle of the present invention (e.g., driving assistance system 1 below) is characterized in that it includes: a direction indicator (e.g., direction indicator 6L, 6R below) disposed on the body of the straddle-type vehicle; a vehicle speed detection means (e.g., vehicle speed sensor 2 below) for detecting the vehicle speed of the aforementioned vehicle body; an inertial detection means (e.g., inertial measurement device 3 below) for detecting the axial acceleration and axial angular velocity about each of the three axes defined for the aforementioned vehicle body; and a driving direction change behavior detection means (e.g., driving direction change behavior detection device 3 below). The vehicle direction change detection unit 81 detects the vehicle's direction change behavior based on the vehicle speed detection value, the axle acceleration detection value, and the axle angular velocity detection value of the aforementioned vehicle speed detection means; and the notification means (e.g., the direction indicator control unit 82, the direction indicators 6L, 6R, the vehicle-to-vehicle communication control unit 83, and the vehicle communication device 5) notify surrounding traffic participants located around the vehicle of the vehicle's direction of travel when the aforementioned direction change behavior is detected while the aforementioned direction indicator is not in operation.

[0011] (2) At this time, it is preferable that the aforementioned means of detecting the change of travel direction includes: a steering angle estimation unit (for example, the steering angle estimation unit 812 below), which calculates the steering angle estimation value of the vehicle body based on the aforementioned vehicle speed detection value, the aforementioned axle acceleration detection value and the aforementioned axle angular velocity detection value; and a behavior detection unit (for example, the behavior detection unit 814 below), which detects the aforementioned change of travel direction based on the aforementioned steering angle estimation value.

[0012] (3) In this case, it is preferable that the aforementioned means of detecting changes in travel direction further includes a rider applied torque estimation unit (for example, the rider applied torque estimation unit 813 described below), which calculates the rider applied torque estimation value caused by the shift of the rider's center of gravity while straddling the aforementioned vehicle body based on the aforementioned vehicle speed detection value, the aforementioned axle acceleration detection value, and the aforementioned axle angular velocity detection value; the aforementioned behavior detection unit detects the aforementioned changes in travel direction based on the aforementioned steering angle estimation value and the aforementioned rider applied torque estimation value.

[0013] (4) In this case, it is preferable that the aforementioned notification means notify the aforementioned direction of travel to the aforementioned surrounding traffic participants by activating the aforementioned direction indicator.

[0014] (5) In this case, it is preferable that the aforementioned notification means notify the aforementioned traffic participants of the aforementioned direction of travel by sending information related to the aforementioned direction of travel to the vehicle communication device that is moving with the aforementioned surrounding traffic participants.

[0015] (6) In this case, it is preferable that the aforementioned driving assistance system further includes a reporting means (e.g., the reporting control unit 84 and HMI7 described below), which reports to the aforementioned rider when the absolute value of the estimated torque applied by the aforementioned rider exceeds a certain limit value.

[0016] (The effect of the invention)

[0017] (1) In the driving assistance system for a straddle-type vehicle of the present invention, the means for detecting changes in the direction of travel of the straddle-type vehicle detects changes in the direction of travel of the vehicle body based on vehicle speed detection value, axle acceleration detection value, and axle angular velocity detection value. When a change in the direction of travel is detected while the direction indicator is not activated, the notification means notifies surrounding traffic participants of the direction of travel of the vehicle body. Thus, even if the rider changes the direction of travel of the vehicle body without activating the direction indicator, surrounding traffic participants can quickly identify the presence of the straddle-type vehicle that has changed its direction of travel. Therefore, accidents between the straddle-type vehicle that has changed its direction of travel and surrounding traffic participants can be prevented, thereby improving traffic safety.

[0018] (2) The means for detecting changes in travel direction includes: a steering angle estimation unit that calculates a steering angle estimation value of the vehicle body based on the vehicle speed detection value, the axle acceleration detection value, and the axle angular velocity detection value; and a behavior detection unit that detects changes in travel direction based on the steering angle estimation value. Therefore, according to the present invention, changes in the travel direction of the vehicle body can be detected quickly, thus enabling surrounding traffic participants to more quickly identify the presence of a straddle-type vehicle changing its travel direction, thereby improving traffic safety.

[0019] (3) The method for detecting changes in travel direction further includes a rider-applied torque estimation unit, which calculates an estimated value of the rider-applied torque caused by the shift of the rider's center of gravity while straddling the vehicle, based on vehicle speed detection values, axle acceleration detection values, and axle angular velocity detection values. Therefore, according to the present invention, the behavior detection unit detects changes in travel direction based on steering angle estimation values ​​and rider-applied torque estimation values, thereby enabling faster and more accurate detection of changes in travel direction, and thus improving traffic safety.

[0020] (4) In this invention, when a change in driving direction is detected while the direction indicator is not in operation, the notification means notifies surrounding road users of the vehicle's driving direction by activating the direction indicator. Therefore, according to this invention, the vehicle's driving direction can be notified to surrounding road users using a simple configuration, thereby improving traffic safety.

[0021] (5) In this invention, when a change in travel direction is detected while the direction indicator is not in operation, a notification means notifies surrounding traffic participants of the vehicle's travel direction by sending information related to the travel direction to an onboard communication device that is moving with surrounding traffic participants. Thus, according to this invention, surrounding traffic participants can quickly identify the presence of a straddle-type vehicle appearing from an unseen location, thereby improving traffic safety.

[0022] (6) Reporting means that when the absolute value of the torque estimate applied by the rider exceeds a certain limit, that is, when the rider needs to change the direction of travel of the vehicle due to extreme center of gravity shift, the rider is informed, thereby preventing rollover and improving traffic safety. Attached Figure Description

[0023] Figure 1 This is a diagram illustrating the configuration of a driving assistance system according to an embodiment of the present invention.

[0024] Figure 2 This is a functional block diagram showing the structure of the direction-of-travel change detection unit.

[0025] Figure 3 This is a picture of a motorcycle viewed from the side, stationary in a straight-line posture.

[0026] Figure 4 This is a schematic diagram illustrating a two-mass model.

[0027] Figure 5 This is a diagram showing the configuration of the control circuit for the rider's external force observation device.

[0028] Figure 6 It is a diagram that schematically shows the movement path of a motorcycle and the vehicles behind it when overtaking. Detailed Implementation

[0029] Hereinafter, a driving assistance system according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0030] Figure 1 This diagram illustrates the configuration of the driving assistance system 1 according to this embodiment. The driving assistance system 1 is mounted on a motorcycle (not shown) which is a straddle-type vehicle. The motorcycle's drive source can be an internal combustion engine, a rotary electric motor, or a combination thereof. Furthermore, the power source for the rotary electric motor can be a secondary battery, a capacitor, or a fuel cell. The following description focuses on the application of the driving assistance system 1 to a motorcycle, but the invention is not limited thereto. Besides motorcycles, the invention can also be applied to straddle-type vehicles such as tricycles, quadricycles, and bicycles with prime movers.

[0031] The driving assistance system 1 assists the rider in safely driving the motorcycle. The following describes the direction of travel notification function, one of the various driving assistance functions implemented by the driving assistance system 1, which notifies surrounding road users of the vehicle's direction of travel.

[0032] The driving assistance system 1 includes a vehicle speed sensor 2, an inertial measurement unit 3, a direction indicator switch 4L, 4R, an in-vehicle communication device 5, a direction indicator 6L, 6R, a human-machine interface (HMI7) 7 (hereinafter referred to as "HMI7"), and a driving assistance control device 8.

[0033] Vehicle speed sensor 2 detects the speed of movement along the vehicle's direction of travel (hereinafter referred to as "vehicle speed") and sends a signal corresponding to the detected vehicle speed value to driver assistance control device 8. In this vehicle speed sensor 2, for example, a rotary encoder is used that outputs a signal corresponding to the rotational speed of the rear wheel (not shown).

[0034] The inertial measurement unit 3 includes: multiple accelerometers for detecting axial acceleration along each of the three axes (x-axis, y-axis, and z-axis) in an orthogonal coordinate system (hereinafter referred to as the local coordinate system) defined with the vehicle body as a reference; multiple angular velocity sensors for detecting axial angular velocity about each axis; and a housing for housing these accelerometers and angular velocity sensors.

[0035] The inertial measurement unit 3 is installed at any position on the vehicle body. Hereinafter, the case where the axis extending along the straight direction of the vehicle body (i.e., the longitudinal direction of the vehicle body) is the x-axis in the local coordinate system, the axis extending along the 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 is described, is not limited to this. Furthermore, hereafter, the acceleration of the vehicle body along the x-axis, y-axis, and z-axis in the local coordinate system will be referred to as x-axis acceleration, y-axis acceleration, and z-axis acceleration, and the angular velocities of the vehicle body around the x-axis, y-axis, and z-axis will be referred to as 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 sends signals corresponding to these detected values ​​to the driver assistance control device 8.

[0036] The left turn indicator switch 4L and the right turn indicator switch 4R are rider-operable controls used to inform surrounding road users (hereinafter referred to as "surrounding road users") of the vehicle's direction of travel. They are located, for example, at the base of the left handlebar held by the rider's left hand. If the rider turns on the left turn indicator switch 4L, the turn indicator drive circuit (not shown) activates the left turn indicator 6L, which is located on the left side of the vehicle when viewed from the rider's perspective (i.e., flashes). Similarly, if the rider turns on the right turn indicator switch 4R, the turn indicator drive circuit activates the right turn indicator 6R, which is located on the right side of the vehicle when viewed from the rider's perspective (i.e., flashes).

[0037] The HMI7 consists of multiple interfaces that use sound or images to provide riders with various information or respond to input operations performed by the rider.

[0038] The vehicle communication device 5 transmits various information to the vehicle communication devices of surrounding traffic participants by wirelessly communicating with other vehicle communication devices that move together with them.

[0039] The driver assistance control unit 8 is a computer responsible for controlling driver assistance functions. The driver assistance control unit 8 includes a direction change behavior detection unit 81, a direction indicator control unit 82, a vehicle-to-vehicle communication control unit 83, and a reporting control unit 84, serving as a module for implementing the direction notification function among multiple driver assistance functions.

[0040] The vehicle direction change detection unit 81 detects the vehicle's direction change behavior based on vehicle speed detection values, x-axis, y-axis, and z-axis acceleration detection values ​​(hereinafter, they are collectively referred to as "axis acceleration detection values"), and x-axis, y-axis, and z-axis angular velocity detection values ​​(hereinafter, they are collectively referred to as "axis angular velocity detection values"). Here, direction change behavior refers to the vehicle's behavior when its direction of travel changes, such as when changing lanes, turning left, turning right, or overtaking. More specifically, direction change behavior refers to the vehicle's behavior when, viewed from above, its direction of travel changes from being parallel to the straight-ahead direction to being tilted relative to the straight-ahead direction. Hereinafter, the direction change behavior when the vehicle's direction of travel changes relative to the straight-ahead direction toward the rider's left side is referred to as left-side movement behavior, and the direction change behavior when the vehicle's direction of travel changes relative to the straight-ahead direction toward the rider's right side is referred to as right-side movement behavior.

[0041] Figure 2This is a functional block diagram showing the configuration of the direction change behavior detection unit 81. The 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 uses them to detect the vehicle body's direction change behavior.

[0042] The vehicle state parameter calculation unit 811 calculates the values ​​of multiple vehicle state parameters characterizing the current posture or state of the vehicle body relative to the driving 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 state parameter calculation unit 811 defines an orthogonal coordinate system based on the driving surface as a global coordinate system, and calculates the values ​​of multiple vehicle state parameters defined under this global coordinate system. Here, the X-axis of the global coordinate system is the axis in the same direction as the axis obtained by projecting the x-axis of the local coordinate system onto the driving surface, the Y-axis of the global coordinate system is the axis in the same direction as the axis obtained by projecting the y-axis of the local coordinate system onto the driving surface, and the Z-axis of the global coordinate system is the axis extending in a perpendicular direction orthogonal to the driving surface. Therefore, when the vehicle body is stationary in a straight-line posture, the x-axis, y-axis, and z-axis directions of the local coordinate system are aligned with the x-axis, y-axis, and z-axis directions of the global coordinate system, respectively.

[0043] The vehicle body state parameter calculation unit 811 calculates the values ​​of roll angle (the tilt angle of the vehicle body about the X-axis observed in the global coordinate system), pitch angle (the tilt angle of the vehicle body about the Y-axis observed in the global coordinate system), yaw angle (the rotation angle of the vehicle body about the Z-axis observed in the global coordinate system), roll rate (the time rate of change of the roll angle), pitch rate (the time rate of change of the pitch angle), yaw rate (the time rate of change of the yaw angle), and lateral acceleration (the acceleration of the vehicle body in the Y-axis direction observed in the global coordinate system) as multiple vehicle body state parameters based on the vehicle speed detection value, the acceleration detection value of each axle, and the angular velocity detection value of each axle. The vehicle body state parameter calculation unit 811 calculates the values ​​of multiple vehicle body state parameters based on known methods, such as those described in Japanese Patent Application Publication No. 2015-189300 filed by the applicant in this case.

[0044] The steering angle estimation unit 812 calculates a steering angle estimation value that is equivalent to the estimated value of the front wheel steering angle of the vehicle body based on the values ​​of multiple vehicle body state parameters calculated by the vehicle body state parameter calculation unit 811.

[0045] Figure 3 This is a picture of a motorcycle viewed from the side, stationary in a straight-line posture. Here, in Figure 3 In this context, "δf" represents the front wheel steering angle. The roll angle is indicated by "θcf". Furthermore, "L" represents the caster angle, and "L" represents the axle distance. If the vehicle speed is set to "Vox" and the yaw rate is set to "ωz", the front wheel steering angle δf can be expressed geometrically by the following equation (1). Therefore, the steering angle estimation unit 812 calculates the estimated steering angle value based on the following equation (1). At this time, on the right side of the following equation (1), "Vox" uses the vehicle speed detection value, and "ωz" uses the yaw rate value calculated by the vehicle body state parameter calculation unit 811. The roll angle value calculated by the vehicle body state parameter calculation unit 811 is used, and "L" and "θcf" are predetermined values. In addition, the steering angle prediction value calculated by the steering angle prediction unit 812 based on the following formula (1) will be marked as "δf_hat".

[0046] [Mathematical Expression 1]

[0047]

[0048] Return to Figure 2 The rider applied torque estimation unit 813 calculates the rider applied torque estimation value based on the steering angle estimation value calculated by the steering angle estimation unit 812 and the values ​​of multiple vehicle body state parameters calculated by the vehicle body state parameter calculation unit 811. The rider applied torque estimation value is equivalent to the estimated value of the rider applied torque caused by the shift of the rider's center of gravity while straddling the vehicle body.

[0049] When calculating the estimated value of the torque applied by the rider, the rider-applied torque estimation unit 813 uses a two-mass model, which uses two masses to represent the behavior of the vehicle body and the rider straddling the vehicle body. Furthermore, the details of this two-mass model are described, for example, in Japanese Patent Application Publication No. 2014-91386 filed by the applicant in this case, so only a brief description is given here.

[0050] Figure 4 This is a schematic diagram illustrating a two-mass model. (For example...) Figure 4 As shown, the dual-mass model consists of an inverted pendulum mass 91 and a mass 92 on the road surface. The inverted pendulum mass 91 is located above the road surface S in contact with the vehicle body, depending on the vehicle body's roll angle. The particle 92 on the road surface moves horizontally in the Y-axis direction according to the front wheel steering angle δf, and the movement of the particle 92 on the road surface S in the Y-axis direction is independent of the roll angle of the vehicle body. The point mass.

[0051] Figure 5 This diagram illustrates the configuration of a control circuit for a rider-applied external force observer constructed based on a two-mass model to predict the torque applied by the rider. The rider-applied torque prediction unit 813 utilizes... Figure 5 The rider applies an external force observation device to calculate the estimated value of the torque applied by the rider. In addition, the detailed order of calculating the estimated values ​​of various physical quantities based on the two-mass model is described, for example, in Japanese Patent Application Publication No. 2016-179710 or Japanese Patent Application Publication No. 2017-7550 filed by the applicant in this case, so only a brief explanation is given here.

[0052] exist Figure 5 In the control circuit shown, "m1" represents the mass of the inverted pendulum mass 91, "h′" corresponds to the height of the inverted pendulum mass 91 measured from the road surface S, "K" corresponds to the observer gain, and "1 / S" represents the integration operation. Furthermore, in Figure 5 In the control circuit shown, The lateral angular velocity of the inverted pendulum mass 91 is equivalent to the angular velocity of the inverted pendulum; "τg" is equivalent to the torque generated by the gravity acting on the inverted pendulum mass 91; "τs" is equivalent to the torque generated by the steering of the front wheel; and "τr" is equivalent to the torque applied by the rider due to the shift of the rider's center of gravity. That is, in Figure 5 In the rider-applied external force observer shown, the roll rate is predicted based on the steering input to the front wheel and the rollover force due to gravity. Compared with the actual roll rate The difference arises from the rider's weight shift, from which the estimated value of the torque applied by the rider is calculated.

[0053] The rider-applied torque estimation unit 813 calculates the estimated value of the rider-applied torque using the rider-applied external force observer described above. At this time, the input to the rider-applied external force observer... Using the roll rate calculated by the vehicle body state parameter calculation unit 811, the inputs "τg" and "τs" of the rider-applied external force observer are estimated values ​​calculated through specific calculations. Here, the estimated values ​​of "τg" and "τs" are obtained by inputting the values ​​of multiple vehicle body state parameters calculated by the vehicle body state parameter calculation unit 811 or the estimated steering angle calculated by the steering angle estimation unit 812 into a calculation formula (not shown). Furthermore, below, the rider-applied torque estimation unit 813 will utilize... Figure 5 The estimated value of the rider-applied torque calculated by the rider-applied external force observer is denoted as "τr_hat".

[0054] Return to Figure 2The behavior detection unit 814 detects changes in the vehicle's direction of travel based on the steering angle estimation value δf_hat calculated by the steering angle estimation unit 812 and the rider-applied torque estimation value τr_hat calculated by the rider-applied torque estimation unit 813. When the vehicle is traveling straight, i.e., when the vehicle's direction of travel is approximately parallel to the straight-ahead direction, both the steering angle estimation value δf_hat and the rider-applied torque estimation value τr_hat are approximately 0. Therefore, when the vehicle exhibits leftward movement, either the steering angle estimation value δf_hat or the rider-applied torque estimation value τr_hat changes to the positive side; when the vehicle exhibits rightward movement, either the steering angle estimation value δf_hat or the rider-applied torque estimation value τr_hat changes to the negative side.

[0055] Therefore, when the estimated steering angle value δf_hat is greater than a positive steering angle threshold and the estimated torque value τr_hat applied by the rider is greater than a positive torque threshold, the behavior detection unit 814 detects left-side movement of the vehicle body. Furthermore, when the estimated steering angle value δf_hat is less than a negative steering angle threshold and the estimated torque value τr_hat applied by the rider is less than a negative torque threshold, the behavior detection unit 814 detects right-side movement of the vehicle body.

[0056] Furthermore, in this embodiment, the behavior detection unit 814 has been described as detecting changes in the vehicle's direction of travel based on both the estimated steering angle value δf_hat and the estimated torque applied by the rider τr_hat, as described above. However, the present invention is not limited to this. The behavior detection unit may also detect changes in the vehicle's direction of travel based solely on the estimated steering angle value δf_hat. That is, the behavior detection unit may detect leftward movement of the vehicle when the estimated steering angle value δf_hat is greater than a positive steering angle threshold, and detect rightward movement of the vehicle when the estimated steering angle value δf_hat is less than a negative steering angle threshold.

[0057] Furthermore, in this embodiment, the behavior detection unit 814 detects the vehicle's direction-of-travel change behavior by comparing the estimated steering angle value δf_hat or the estimated torque value τr_hat applied by the rider with a specific threshold. However, the present invention is not limited to this. The magnitude of change in the estimated steering angle value δf_hat or the estimated torque value τr_hat applied by the rider when the vehicle exhibits a direction-of-travel change behavior varies with the vehicle speed. Therefore, the steering angle threshold for the estimated steering angle value δf_hat or the torque threshold for the estimated torque value τr_hat applied by the rider may also vary with the vehicle speed.

[0058] Return to Figure 1When the direction change detection unit 81 detects a change in driving direction while the direction indicators 6L and 6R are not activated, the direction indicator control unit 82 activates the direction indicators 6L and 6R to notify surrounding traffic participants of the vehicle's driving direction. More specifically, when the direction change detection unit 81 detects leftward movement while the left direction indicator 6L is not activated, the direction indicator control unit 82 activates the left direction indicator 6L to notify surrounding traffic participants that the vehicle's driving direction is to the left. Similarly, when the direction change detection unit 81 detects rightward movement while the right direction indicator 6R is not activated, the direction indicator control unit 82 activates the right direction indicator 6R to notify surrounding traffic participants that the vehicle's driving direction is to the right.

[0059] When a direction change detection unit 81 detects a change in driving direction while the direction indicators 6L and 6R are not activated, the vehicle-to-vehicle communication control unit 83 uses the vehicle communication device 5 to send information related to the vehicle's driving direction to the vehicle communication devices moving with surrounding traffic participants, and also notifies surrounding traffic participants of this information via the vehicle-mounted HMIs moving with them. More specifically, when the left turn indicator 6L is not activated and the direction change detection unit 81 detects leftward movement, the vehicle-to-vehicle communication control unit 83 sends information from the vehicle communication device 5 to the vehicle communication devices of surrounding traffic participants indicating that the vehicle's driving direction is to the left. Similarly, when the right turn indicator 6R is not activated and the direction change detection unit 81 detects rightward movement, the vehicle-to-vehicle communication control unit 83 sends information from the vehicle communication device 5 to the vehicle communication devices of surrounding traffic participants indicating that the vehicle's driving direction is to the right.

[0060] As described above, in this embodiment, the notification means consists of a direction indicator control unit 82, direction indicators 6L and 6R, an inter-vehicle communication control unit 83, and an on-board communication device 5.

[0061] When the absolute value of the estimated torque τr_hat applied by the rider, calculated by the direction-change behavior detection unit 81, exceeds a specific limit, that is, when the rider is about to change the direction of travel of the vehicle due to extreme center of gravity shift, the reporting control unit 84 reports a predetermined warning message to the rider via the HMI7. As described above, in this embodiment, the reporting means consists of the reporting control unit 84 and the HMI7.

[0062] The driving assistance system 1 according to this embodiment has the following effects.

[0063] (1) In the driver assistance system 1, the direction change detection unit 81 detects the direction change behavior of the motorcycle body based on the vehicle speed detection value, the acceleration detection value of each axle, and the angular velocity detection value of each axle. When the direction change behavior is detected while the direction indicators 6L and 6R are not activated, the direction indicator control unit 82 or the vehicle-to-vehicle communication control unit 83 notifies surrounding traffic participants of the direction of travel of the motorcycle body. Therefore, even if the rider changes the direction of travel of the motorcycle body without activating the direction indicators 6L and 6R, surrounding traffic participants can quickly identify the presence of the motorcycle changing direction, thus preventing accidents between the motorcycle changing direction and surrounding traffic participants, thereby improving traffic safety.

[0064] (2) The direction-of-journey change behavior detection unit 81 includes: a steering angle estimation unit 812, which calculates a steering angle estimation value δf_hat of the vehicle body based on the vehicle speed detection value, the acceleration detection value of each axle, and the angular velocity detection value of each axle; and a behavior detection unit 814, which detects the direction-of-journey change behavior based on the steering angle estimation value δf_hat. Therefore, according to the driver assistance system 1, the direction-of-journey change behavior of the vehicle body can be detected quickly. Thus, surrounding traffic participants can more quickly identify the presence of a motorcycle changing its direction of travel, thereby improving traffic safety.

[0065] (3) The direction-of-travel change behavior detection unit 81 further includes a rider-applied torque estimation unit 813, which calculates a rider-applied torque estimation value τr_hat caused by the shift of the rider's center of gravity while straddling the vehicle body based on the vehicle speed detection value, the acceleration detection value of each axle, and the angular velocity detection value of each axle. Therefore, according to the driving assistance system 1, the behavior detection unit 814 detects direction-of-travel change behavior based on the steering angle estimation value δf_hat and the rider-applied torque estimation value τr_hat, thereby enabling faster and more accurate detection of direction-of-travel change behavior and improving traffic safety.

[0066] (4) When a change in driving direction is detected while the direction indicators 6L and 6R are not in operation, the direction indicator control unit 82 activates the direction indicators 6L and 6R to notify surrounding road users of the vehicle's driving direction. Thus, according to the driver assistance system 1, the vehicle's driving direction can be notified to surrounding road users with a simple configuration, thereby improving traffic safety.

[0067] (5) When a change in travel direction is detected while the direction indicators 6L and 6R are not operating, the vehicle-to-vehicle communication control unit 83 notifies surrounding traffic participants of the vehicle's travel direction by sending information related to the travel direction from the vehicle-mounted communication device 5 to the vehicle-mounted communication device moving with surrounding traffic participants. Thus, according to the driver assistance system 1, surrounding traffic participants can quickly recognize the presence of a motorcycle appearing from an unseen location, thereby improving traffic safety.

[0068] (6) The report control unit 84 reports a warning message to the rider via HMI7 when the absolute value of the torque estimate τr_hat applied by the rider exceeds a certain limit value, that is, when the rider changes the direction of travel of the vehicle due to extreme center of gravity shift. This can prevent tipping over and improve traffic safety.

[0069] The above description illustrates one embodiment of the present invention, but the invention is not limited thereto. Appropriate modifications to the details are possible within the scope of the invention's intent.

[0070] Figure Labels

[0071] 1. Driving assistance system

[0072] 2. Vehicle speed sensor (vehicle speed detection method)

[0073] 3. Inertial Measurement Unit (Inertial Detection Method)

[0074] 5. Vehicle-mounted communication devices (notification methods)

[0075] 6L, 6R Directional Indicators (Notification Method)

[0076] 7HMI (Reporting Methods)

[0077] 8 Driver Assistance Control Devices

[0078] 81. Department for Detecting Changes in Travel Direction (Methods for Detecting Changes in Travel Direction)

[0079] 811 Vehicle Body Condition Parameter Calculation Unit

[0080] 812 Steering Angle Prediction Unit

[0081] 813 Rider-applied torque estimation unit

[0082] 814 Behavioral Detection Department

[0083] 82. Direction indicator control unit (notification means)

[0084] 83. Vehicle Communication Control Department (Notification Method)

[0085] 84. Reporting Control Department (Reporting Methods)

Claims

1. A driver assistance system for a straddle-type vehicle, characterized in that it comprises: Direction indicator, mounted on the body of a motorcycle; Vehicle speed detection method, to detect the speed of the aforementioned vehicle body; and, Inertial detection methods are used to detect the axial acceleration and angular velocity about each of the three axes defined for the aforementioned vehicle body. Furthermore, the driving assistance system of the straddle-type vehicle includes: The method for detecting changes in travel direction detects the aforementioned vehicle vehicle's changes in travel direction based on the vehicle speed detection value from the aforementioned vehicle speed detection method, the axial acceleration detection value from the aforementioned inertial detection method, and the axial angular velocity detection value; and, The notification mechanism, when detecting a change in the aforementioned direction of travel while the aforementioned direction indicator is not in operation, notifies surrounding traffic participants located around the aforementioned vehicle of the vehicle's direction of travel. The aforementioned methods for detecting changes in travel direction include: The steering angle estimation unit calculates the estimated steering angle of the vehicle body based on the aforementioned vehicle speed detection value, the aforementioned axle acceleration detection value, and the aforementioned axle angular velocity detection value. The rider-applied torque estimation unit calculates, based on the aforementioned vehicle speed detection value, the aforementioned shaft acceleration detection value, and the aforementioned shaft angular velocity detection value, a rider-applied torque estimation value caused by the shift of the rider's center of gravity while straddling the aforementioned vehicle body; and, The behavior detection unit detects the aforementioned change in travel direction behavior based on the aforementioned estimated steering angle and the aforementioned estimated torque applied by the rider.

2. The driving assistance system for a straddle-type vehicle according to claim 1, wherein, The aforementioned notification method, by activating the aforementioned directional indicator, informs the aforementioned surrounding traffic participants of the aforementioned direction of travel.

3. The driving assistance system for a straddle-type vehicle according to claim 1, wherein, The aforementioned notification method notifies the surrounding traffic participants of the aforementioned direction of travel by sending information related to the aforementioned direction of travel to the vehicle-mounted communication device that is moving with the surrounding traffic participants.

4. The driving assistance system for a straddle-type vehicle according to claim 1, wherein, The driving assistance system of the straddle-type vehicle further includes a reporting means that reports to the rider when the absolute value of the estimated torque applied by the rider exceeds a specific limit value.

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