Saddle-ridden vehicle driving support system and saddle-ridden vehicle

Abstract

The present invention appropriately gives a driver notifications that correspond to the level of danger posed by other vehicles that approach from behind. A saddle-ridden vehicle driving support system (S) comprises a detection unit (11) that detects a travel path (R1) that a vehicle (V) travels, a determination unit (15) that determines the movement states of moving objects relative to the vehicle (V), an estimation unit (12) that estimates the position of the vehicle (V) on the travel path (R1), a setting unit (16) that sets a virtual line inside a demarcation line that demarcates the travel path (R1), and a notification means (18) that, when the estimated position of the vehicle (V) has crossed the virtual line that has been set, notifies the driver of the vehicle (V) in a recognizable manner that the virtual line has been crossed.

Description

Driving assistance system for saddle-ride type vehicle and saddle-ride type vehicle

[0001] The present invention relates to a driving assistance system for a saddle-ride type vehicle and a saddle-ride type vehicle.

[0002] A known technology relating to a driving assistance system for a saddle-ride type vehicle is disclosed in Patent Document 1. The saddle-ride type vehicle disclosed in Patent Document 1 is equipped with a device capable of detecting a vehicle approaching from behind while the vehicle is traveling.

[0003] Patent No. 6764896

[0004] As described above, the straddle-type vehicle of Patent Document 1 is capable of detecting another vehicle approaching from behind, but has the problem of suspending detection of a vehicle approaching from behind when the roll angle of the vehicle is greater than a predetermined threshold. Generally, straddle-type vehicles have more freedom in their driving position within a roadway than four-wheeled vehicles. Therefore, when driving in a situation where there is free space between the vehicle and the adjacent roadway, there is no need to immediately issue a warning. However, in Patent Document 1, a warning is always issued to the driver when a vehicle approaching from behind is detected, which can be annoying to the driver, and there has been a demand for an improvement in this regard.

[0005] The present invention aims to solve the above-mentioned problems and provide a driving assistance system for a saddle-type vehicle and a saddle-type vehicle that can provide an appropriate warning to the driver based on the level of danger of a moving object, such as another vehicle, approaching from behind.

[0006] In order to solve the above problem, the driving assistance system for a saddle-type vehicle of the present invention comprises a detection unit that detects the roadway on which the vehicle is traveling, a determination unit that determines the movement state of a moving object relative to the vehicle, an estimation unit that estimates the position of the vehicle on the roadway, a setting unit that sets a virtual line inside the dividing line that separates the roadway, and a notification means that, when the estimated position of the vehicle crosses the set virtual line, notifies the driver of the vehicle of this information in a recognizable manner.

[0007] A straddle-type vehicle according to the present invention includes the driving assistance system for a straddle-type vehicle described above.

[0008] According to the driving assistance system for a saddle-type vehicle and the saddle-type vehicle of the present invention, it is possible to provide the driver with an alert based on the level of danger of a moving object, such as another vehicle, approaching from behind, thereby realizing appropriate alerts to the driver.

[0009] FIG. 1 is a conceptual diagram of the configuration of a driving assistance system for a saddle-riding type vehicle and a saddle-riding type vehicle according to an embodiment of the present invention. FIG. 1 is a schematic diagram showing an example of a road detected by a saddle-riding type vehicle (host vehicle). FIG. 2 is a schematic diagram showing an example of a trajectory line of the host vehicle and a virtual line set on the road. FIG. 3 is a schematic diagram showing an area set based on TTC. FIG. 4 is a schematic diagram showing an example of a traveling state of the host vehicle. FIG. 5 is a schematic diagram showing an example of a traveling state of the host vehicle. FIG. 6 is a schematic diagram showing an example of a posture when changing the traveling direction. FIG. 7 is a table showing the relationship between areas TTCS1 to 3 and white line thresholds. FIG. 8 is a table showing the relationship between warning intensity and warnings 1 to 3. FIG. 9 is a flowchart for explaining control of warning processing.

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following embodiments, a driving assistance system for a saddle-riding type vehicle and a saddle-riding type vehicle will be described using a motorcycle as an example, but the vehicle type is not limited to this. For example, the present invention can also be applied to vehicles such as three-wheeled motor vehicles and all-terrain vehicles (ATVs).

[0011] A driving assistance system for a saddle-ride type vehicle (hereinafter referred to as the "driving assistance system") S is a system that can provide a warning to the driver according to the level of danger of a vehicle approaching from behind. Hereinafter, a vehicle equipped with the driving assistance system S will be referred to as the host vehicle V, and a vehicle approaching from behind the host vehicle will be referred to as another vehicle A.

[0012] As shown in Fig. 1, the driving assistance system S includes an on-vehicle control unit 10 and a camera 20 that captures images of the area behind the vehicle V. The on-vehicle control unit 10 is disposed at an appropriate location (not shown) on the vehicle V. The camera 20 is attached to the rear end of the vehicle V. The attachment position of the camera 20 is not limited to the rear end of the vehicle V, and may be anywhere that can capture images of the area behind the vehicle V, such as the frame, handlebars, cowl, or fender.

[0013] The on-board control unit 10 is a device that issues a notification to the driver based on an image of the rear of the vehicle V captured by the camera 20. The on-board control unit 10 is configured to include, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), an input / output circuit, etc. The on-board control unit 10 executes control by performing various arithmetic processing based on input from the camera 20, input from a roll sensor 21 and a yaw rate sensor 22 (described later), programs and data stored in the ROM, etc.

[0014] The camera 20 functions as an imaging unit and captures an image of a roadway R (see FIG. 2 ) behind the vehicle V. The camera 20 is activated and begins capturing images when the driver turns on the ignition. As shown in FIG. 2 , the camera 20 captures images of the roadway R behind the vehicle V, for example, on a two-lane road, with depth, of the left and right regions including the roadway R1 (driving lane) on which the vehicle V is traveling and the adjacent roadway R2 (passing lane). The camera 20 outputs image data of the captured roadway R to the on-board control unit 10.

[0015] The camera 20 may be a monocular camera or a stereo camera. Instead of the camera 20, information about the road R may be acquired using LiDAR, radar (millimeter-wave radar, infrared radar, laser radar, etc.). When a stereo camera is used, the road R and other vehicles A can be captured in three dimensions, improving the detection accuracy.

[0016] As shown in FIG. 1 , the vehicle control unit 10 includes a detection unit 11, an estimation unit 12, a traveling direction estimation unit 13, a distance specification unit 14, a determination unit 15, a setting unit 16, a virtual line arrival determination unit 17, and a notification means 18.

[0017] The detection unit 11 acquires image data captured by the camera 20 and detects road surface conditions behind the vehicle V from the acquired image data. Specifically, as shown in FIG. 2 , when the road R1 on which the vehicle V is traveling is a paved road, the detection unit 11 identifies the dividing lines (in this embodiment, a white line L1 and an outer roadway line L2) that divide the road R1, and sets a white line reference line L11 and an outer roadway reference line L12 in the image data of the road R. In the following description, the dividing line that divides the road R1 from the adjacent road R2 is referred to as the white line L1. However, the white line L1 is not limited to a white line, and is used as a conceptual name that includes, for example, a yellow or other colored solid or broken line. The outer roadway line L2 is a section line (including a shoulder strip) that divides the roadway (road R1) from the sidewalk or the like outside it, and is, for example, a white solid line. The white line boundary reference line L11 is a reference line that runs along the inside of the white line L1. The outer roadway reference line L12 is a reference line that runs along the inside of the outer roadway line L2. In addition, in an area further outside the outer roadway line L2, a boundary line L13 is set that runs along buildings, structures, etc. adjacent to the road. The boundary line L13 can be detected as the outer roadway line when the travel path R1 is an unpaved road.

[0018] The detection unit 11 acquires from the camera 20 a plurality of image data that change as the host vehicle V moves, and repeatedly executes a process of setting the white lines L1, the outer roadway lines L2, and the boundary line L13 each time image data is acquired. Various known methods can be used to detect the white lines L1, the outer roadway lines L2, and the boundary line L13, such as a process of sequentially scanning the image data and leaving edges by changing the rising and falling edges of brightness. The detection unit 11 can also use a similar method to detect the center line SL, which serves as the boundary line between the host vehicle V and the road R3 on the opposite lane, from the image data.

[0019] The detection unit 11 outputs information such as image data, white lines L1, outer roadway lines L2, and boundary lines L13 to the estimation unit 12 and the determination unit 15. Hereinafter, as shown in FIG. 3 , an example will be described in which another vehicle A approaches the host vehicle V on the road R2, which may be a more dangerous situation, when the host vehicle V changes lanes from the road R1 to the road R2.

[0020] The estimation unit 12 estimates the position of the host vehicle V on the travel path R1. Specifically, the estimation unit 12 acquires information from the detection unit 11, and as shown in FIG. 2, identifies the position of the host vehicle V (see FIGS. 1 and 3, the same applies below) in the image data from the position of the camera relative to the image data. Then, the estimation unit 12 sets a trajectory line TR. The trajectory line TR is given as a set of positions of the host vehicle V on the image data at each of multiple consecutive times in the past. The front end portion TR1 of the trajectory line TR (the bottom end of the image in FIG. 2) is the latest position of the host vehicle V. Note that the position of the host vehicle V may be estimated using a known position detection means such as a GPS in combination.

[0021] The estimation unit 12 also determines the distance W2 of the vehicle V from the white line L1 on the roadway R1. Specifically, the distance determination unit 14 calculates the left-right width W1 of the roadway R1 based on the white line reference line L11 and the roadway outer reference line L12 acquired from the detection unit 11, and calculates the position of the front end portion TR1 of the trajectory line TR on the roadway R1, thereby determining the distance W2 from the white line reference line L11, for example.

[0022] For example, when the value of distance W2 is smaller than the value of distance W1 / 2, using the center of the road R1 in the left-right direction as a reference, the smaller the value, the more the host vehicle V is traveling on the side closer to the white line L1 (to the right in the direction of travel), as shown in Figure 3. Conversely, when the value of distance W2 is larger than the value of distance W1 / 2, the larger the value, the more the host vehicle V is traveling on the side farther from the white line L1 (to the left in the direction of travel). The estimation unit 12 outputs the estimated position information of the host vehicle V to the traveling direction estimation unit 13, the virtual line arrival determination unit 17, and the notification means 18.

[0023] The traveling direction estimation unit 13 estimates the direction in which the host vehicle V will travel on the traveling path R1. The traveling direction estimation unit 13 estimates the direction in which the host vehicle V will travel based on the trajectory line TR acquired from the estimation unit 12. For example, as shown in FIG. 3 , if the extension direction of the trajectory line TR from a certain point in time to a point in time after a predetermined time has elapsed (a vector pointing from the front end portion TR1 of the trajectory line TR at the certain point in time to the front end portion TR1 of the trajectory line TR at the predetermined time elapsed) is a direction toward the white line L1, it is estimated that the host vehicle V is traveling in a direction approaching the white line L1, that is, there is a high possibility that the host vehicle V will change lanes from the traveling path R1 to the traveling path R2. Conversely, if the extension direction of the trajectory line TR from a certain point in time to a point in time after a predetermined time has elapsed is a direction away from the white line L1, it is estimated that there is a low possibility that the host vehicle V will change lanes from the traveling path R1 to the traveling path R2.

[0024] On the other hand, if the direction of extension of the trajectory line TR is neither toward nor away from the white line L1 but is a substantially straight line (a direction extending along the white line L1, including a curve), as shown in Figure 5, it is estimated that the vehicle is continuing to travel inside the white line L1, i.e., that there is a low possibility of changing lanes from roadway R1 to roadway R2. The vehicle V1 shown in Figure 5 is traveling straight inside the white line L1 without crossing the white line L1 on the side closer to the white line L1. The vehicle V2 is traveling straight within roadway R1 on the side closer to the outer lane line L2. In this case, a free space FS for avoiding danger is secured between the vehicle V2 and the white line L1 on the right side of the vehicle V2's direction of travel.

[0025] The traveling direction estimation unit 13 corrects the estimated traveling direction of the host vehicle V using the measurement values ​​of the roll sensor 21 and yaw rate sensor 22 provided on the host vehicle V. Generally, motorcycles are configured to change their traveling direction by tilting the body, and reliable estimation of the traveling direction is possible by using the measurement values ​​of the roll angle, which affects the stability and ease of turning of the body, and the yaw angle, which provides important information related to the orientation and direction change of the body, to correct the traveling direction.

[0026] 8 , when viewed from behind, the host vehicle V is rotating to the right about a vertical axis E1 while traveling with an inclination axis E2 that is tilted to the right with respect to the vertical axis E1, that is, when the host vehicle V is traveling with its nose facing right and its body tilted to the right, the traveling direction of the host vehicle V is corrected by a known method based on the measured roll angle and yaw angle. For the correction, it is not necessary to use both the roll sensor 21 and the yaw rate sensor 22; either one of them may be used to estimate the traveling direction of the host vehicle V. The traveling direction estimation unit 13 outputs information on the estimated traveling direction to the determination unit 15, the virtual line arrival determination unit 17, and the notification means 18.

[0027] The determination unit 15 determines the movement state of another vehicle A (moving object) relative to the host vehicle V. The movement state of the other vehicle A refers to a state including where the other vehicle A is moving in the left-right direction of the travel path R1, its speed (including relative speed), its traveling direction (future position), its distance (including relative distance from the host vehicle V), and other information such as the acceleration and deceleration of the other vehicle A. The determination unit 15 determines whether or not there is another vehicle A approaching the host vehicle V from behind, as shown in FIG. 3 , based on image data acquired from the detection unit 11. In this case, the determination unit 15 can determine whether or not there is another vehicle A on both the travel path R1 of the host vehicle V and the adjacent travel path R2.

[0028] When the determination unit 15 determines that another vehicle A is present, it calculates the relative distance between the host vehicle V and the other vehicle A and the relative speed between the host vehicle V and the other vehicle A. Then, the determination unit 15 uses the calculated relative distance (inter-vehicle distance) and relative speed to calculate a TTC (Time To Collision), which is a value related to the relative position between the host vehicle V and the other vehicle A. The TTC represents the predicted time to collision if the host vehicle V and the other vehicle A maintain their current relative speed, and can be obtained, for example, by dividing the inter-vehicle distance by the relative speed between the host vehicle V and the other vehicle A.

[0029] The speed of the host vehicle V is determined by a known method based on a wheel speed sensor 23 (see FIG. 1) attached to, for example, the front wheels of the host vehicle V. The speed of the other vehicle A is determined by a known method based on the acquired multiple image data.

[0030] The determination unit 15 sets a plurality of regions TTCSCn (Cn is 1 to 3) for the calculated TTC on the roadway R2 of the other vehicle A as shown in FIG. 4 . In FIG. 4 , TTC0 is the collision time based on the rear end of the host vehicle V. TTC+t is the warning start time for a collision warning set between the host vehicle V and the other vehicle A based on the collision time, and is set based on a predetermined inter-vehicle distance set between the host vehicle V and the other vehicle A. TTC-t is the predicted time based on the collision time at which the other vehicle A approaching from behind will be alongside the host vehicle V, and is set based on the relative speed between the host vehicle V and the other vehicle A. In FIG. 4 , the two-dot chain line indicated by the symbol LL is a loss reference line at which it becomes difficult for the camera 20 to capture an image of the other vehicle A. In other words, the system is configured to predict in advance the position of the other vehicle A entering beyond the loss reference line LL.

[0031] These regions TTCSCn (Cn is 1 to 3) are used when setting the intensity of the warning issued by the notification means 18, which will be described later. In this embodiment, the region on the roadway R2 defined by the loss reference line LL and the warning start time TTC+t is divided into two regions, TTCSC3 and TTCSC2, starting from the rear. The region defined by the loss reference line LL and the predicted time TTC-t is designated as TTCSC1. The region TTCSC3, which is the farthest from the host vehicle V, indicates that the collision with the host vehicle V will occur within a range of 5 to 3 seconds, while the region TTCSC2 indicates that the collision will occur within a range of 3 to 1 second. The region TTCSC1 indicates that the collision will occur within 1 second. The determination unit 15 outputs the set information to the notification means 18.

[0032] 2 and 4, the setting unit 16 sets white line thresholds (virtual lines) D1 and D2 inside the white line L1 on the road R1, which serve as criteria for determining whether or not to issue a warning to the vehicle V. Specifically, when the determination unit 15 detects another vehicle A approaching from behind, the setting unit 16 sets one of the white line thresholds D1 and D2 as a line on the image data in accordance with conditions described below.

[0033] The white line thresholds D1 and D2 are set based on the displacement of the front end portion TR1 of the locus line TR in the width direction of the road R1 per unit time (displacement in the lane width direction). The white line threshold D1 is set when the displacement of the front end portion TR1 of the locus line TR in the lane width direction per unit time is small, for example, when the host vehicle V gradually approaches the white line L1 as shown in Fig. 6. On the other hand, the white line threshold D2 is set when the displacement of the front end portion TR1 of the locus line TR in the lane width direction per unit time is large, for example, when the host vehicle V suddenly approaches the white line L1 as shown in Fig. 7.

[0034] As shown in FIG. 2 , the white line thresholds D1 and D2 have distances W4 and W3, respectively, relative to the white line L1 (white line reference line L11). The distance W3 of the white line threshold D2 is greater than the distance W4 of the white line threshold D1. As a result, the white line threshold D2 is set farther away from the white line L1. That is, when the displacement of the front end portion TR1 of the trajectory line TR in the lane width direction per unit time is large, the setting unit 16 determines that the risk of the host vehicle V changing lanes is higher than when the displacement is small, and sets the distance W3 to speed up the notification to the driver, as described below. Here, the white line threshold D2 is set farther away from the white line L1 as the speed at which the host vehicle V (trajectory line TR) approaches the white line L1 increases. Furthermore, the white line threshold D2 is set farther away from the white line L1 as the relative speed between the host vehicle V and the other vehicle A increases. The setting unit 16 outputs information on the set white line thresholds D1 and D2 to the virtual line arrival determining unit 17 and the informing means 18.

[0035] The virtual line reach determination unit 17 determines whether the trajectory line TR of the host vehicle V has reached the white line threshold D1 (D2). Specifically, as shown in FIG. 3 , the virtual line reach determination unit 17 determines that the host vehicle V has reached the white line threshold D1 (D2) when the trajectory line TR of the host vehicle V crosses the white line threshold D1 (D2) (when the relationship of white line threshold D1 (D2) > trajectory line TR is established). When the virtual line reach determination unit 17 determines that the host vehicle V has reached the white line threshold D1 (D2), it outputs the determination result to the notification means 18.

[0036] The notification means 18 notifies the driver of the host vehicle V in a recognizable manner that another vehicle A is approaching from behind the host vehicle V. Specifically, when the notification means 18 acquires a determination result from the virtual line arrival determination unit 17, that is, when there is a risk of contact with the other vehicle A due to the host vehicle V changing lanes, the notification means 18 notifies the driver by vibrating the engine E (see FIG. 1 ) of the host vehicle V.

[0037] When vibrating the engine E, the notification means 18 controls the fuel supply device (not shown) to cut off combustion at a predetermined period among a plurality of combustion cycles (controls the intake air amount), thereby causing the engine E to vibrate.

[0038] The notification unit 18 has a function of being able to switch the intensity of the notification (intensity of the warning). Specifically, as shown in Fig. 9, the notification unit 18 identifies "Warning 1 to 3" corresponding to the intensity of the notification based on the relationship between the areas TTCS1 to TTCS3 set by the determination unit 15 and the white line threshold values ​​D1 and D2 set by the setting unit 16.

[0039] As shown in FIG. 10 , the intensity of the warning has three levels: "weak," "medium," and "strong." Warning 1 is the weakest of the three levels, Warning 2 is the intermediate level, "medium," and Warning 3 is the strongest, "strong." The intensity of the warning can be changed by increasing the vibration or by changing the vibration period. For example, when changing the rhythm of the vibration, Warning 1 controls to cut fuel in seven fuel cycles out of nine combustion cycles. Also, Warning 2 controls to cut fuel in three fuel cycles out of five combustion cycles. Also, Warning 3 controls to cut fuel in three fuel cycles out of seven fuel cycles. Vibrations with a predetermined period can be generated by controlling to cut fuel in such a manner.

[0040] 4 and 9, for the white line threshold D1, the areas TTCSC3 and TTCSC2 are Warning 1, and the area TTCSC1 is Warning 2. On the other hand, for the white line threshold D2, the area TTCSC3 is Warning 2, and the areas TTCSC2 and TTCSC1 are Warning 3. In other words, the strength of the warning is set to increase as the relative distance between the host vehicle V and the other vehicle A decreases and the other vehicle A is lined up to the side of the host vehicle V.

[0041] Furthermore, the notification means 18 is configured not to issue a notification when the traveling direction estimation unit 13 estimates that the host vehicle V is traveling straight ahead, even when the determination result is obtained from the virtual line arrival determination unit 17. Specifically, the notification means 18 does not issue a notification to the driver when it determines that the extension direction of the trajectory line TR per unit time is approximately linear and that the host vehicle V is traveling a distance W2 that does not cause the host vehicle V to stray into the adjacent travel path R2.

[0042] Next, the warning processing will be described with reference to the flowchart in Fig. 11. First, in step ST1 in Fig. 11, the detection unit 11 reads image data of the road R captured by the camera 20 and detects the road surface conditions behind the vehicle V from the image data. In this case, the detection unit 11 sets a white line reference line L11 and an outer roadway reference line L12 in the image data from the white line L1 and outer roadway line L2 of the road R1.

[0043] Thereafter, in step ST2, the estimation unit 12 estimates the position of the host vehicle V on the travel path R1. Then, the estimation unit 12 acquires a trajectory line (host vehicle trajectory) TR of the host vehicle V based on multiple image data that change as the host vehicle V moves. The estimation unit 12 also specifies the left-right width W1 of the travel path R1 and the distance W2 of the host vehicle V from the white line L1. The traveling direction estimation unit 13 also estimates the traveling direction of the host vehicle V. Then, the traveling direction estimation unit 13 corrects the estimated traveling direction of the host vehicle V using the measured values ​​of the roll sensor 21 and the yaw rate sensor 22.

[0044] In step ST3, the determination unit 15 determines whether or not there is another vehicle A approaching the vehicle V from behind. If the determination unit 15 determines in step ST3 that there is no another vehicle A approaching the vehicle V from behind (step ST2, No), the start of the warning process is terminated. Note that the start of the warning process is repeated at a predetermined cycle.

[0045] On the other hand, if the determination unit 15 determines in step ST3 that another vehicle A is present (step ST2, Yes), the process proceeds to step ST4, where the speed of the host vehicle V is acquired, and the process proceeds to step ST5, where the determination unit 15 calculates the relative distance between the host vehicle V and the other vehicle A. The determination unit 15 also calculates the relative speed between the host vehicle V and the other vehicle A. Thereafter, in step ST6, the determination unit 15 calculates the TTC based on the calculated relative distance and relative speed. Then, the process proceeds to step ST7, where the determination unit 15 sets areas TTCS1 to TTCS3 on the driving route R2 based on the calculated TTC.

[0046] Then, in step ST8, the setting unit 16 calculates the displacement of the trajectory line TR per unit time in the width direction of the road R1, and proceeds to step ST9, where it sets one of the white line thresholds D1 and D2 on the image data.

[0047] Thereafter, in step ST10, the virtual line reach determination unit 17 determines whether or not the trajectory line TR of the vehicle V has reached the white line threshold value D1 (D2). If it is determined in step ST10 that the trajectory line TR has not reached the white line threshold value D1 (D2) (step ST10, No), the control of the notification processing is terminated.

[0048] On the other hand, if it is determined in step ST10 that the trajectory line TR has reached the white line threshold value D1 (D2) (step ST10, Yes), the process proceeds to step ST11, where it is determined whether or not the host vehicle V is traveling straight. The determination of whether or not the host vehicle V is traveling straight is made based on the estimation result by the traveling direction estimation unit 13.

[0049] If it is determined in step ST11 that the vehicle V is traveling straight ahead (step ST11, Yes), the control of the notification process is terminated. On the other hand, if it is determined in step ST11 that the vehicle V is not traveling straight ahead (step ST11, No), the process proceeds to step ST12.

[0050] In step ST12, the notification means 18 sets (switches) the intensity of the notification and controls the notification. In this case, the notification means 18 identifies "Warning 1 to 3" corresponding to the intensity of the notification based on the relationship between the regions TTCS1 to 3 and the white line thresholds D1 and D2. Then, the notification means 18 controls to cut fuel in the combustion cycle based on the identified "Warning 1 to 3," and ends the notification processing control.

[0051] According to the driving assistance system S of the present embodiment described above, it is possible to provide the driver with a warning based on the danger level of another vehicle A approaching from behind, and to provide the driver with an appropriate warning when changing lanes. Furthermore, since the warning is only issued when the vehicle V crosses the white line thresholds D1 and D2, it is possible to prevent unnecessary warnings from being issued when the driver has no intention of changing lanes (when the vehicle does not cross the white line thresholds D1 and D2 and does not approach the white line L1).

[0052] In addition, since the vehicle is equipped with a direction of travel estimation unit 13 that estimates the direction of travel of the vehicle V, it is possible to estimate the future position of the vehicle V, and to appropriately notify the driver of the danger level of another vehicle A approaching from behind.

[0053] In addition, the judgment unit 15 can also detect other vehicles A moving from behind the vehicle V to the side of the vehicle V, so it can appropriately alert the driver of other vehicles A approaching or entering the blind spots that change depending on the position within the driving path R1 specific to motorcycles.

[0054] Furthermore, the setting unit 16 sets the white line threshold D2 to a position farther away from the white line L1 as the speed at which the position (trajectory line TR) of the host vehicle V approaches the white line L1 increases, thereby enabling an early warning that reflects the driver's strong intention to change lanes. Furthermore, the setting unit 16 sets the white line threshold D2 to a position farther away from the white line L1 as the relative speed between the host vehicle V and the other vehicle A increases, thereby enabling an early warning that reflects the driver's strong intention to change lanes.

[0055] Furthermore, since the detection unit 11 detects the roadway R1 on which the host vehicle V is traveling from the image captured by the camera 20, it is possible to realize accurate notification with a simple configuration. For example, when detecting a turn by detecting the roll angle, it is difficult to determine whether the vehicle is turning or whether the vehicle body is simply tilting due to the influence of a crosswind, making it difficult to realize accurate notification. In contrast, in this embodiment, the notification is based on the relationship between the trajectory line TR set on the image data captured by the camera 20 and the white line threshold values ​​D1 and D2, so it is possible to realize accurate notification that reflects the driver's intention to change lanes.

[0056] The estimation unit 12 can also determine the distance W2 between the position of the vehicle V and the white line L1, and the determination unit 15 sets the intensity of the notification from the notification means 18 based on the determined distance W3 and the determined movement state of the other vehicle A. As a result, if the amount of change per unit time of the trajectory line TR of the vehicle V is large, it can be determined that the driver has a strong intention to change lanes, and the notification intensity can be switched to provide an appropriate notification. On the other hand, if the amount of change per unit time of the trajectory line TR of the vehicle V is small, it can be determined that the vehicle V is traveling straight along the roadway R1 and the driver has no intention to change lanes. This includes, for example, when multiple motorcycles are traveling zigzag or meandering along the roadway R1. In such cases, unnecessary notifications can be prevented.

[0057] The determination unit 15 can calculate the TTC using the relative distance and relative speed between the host vehicle V and the other vehicle A, and the notification means 18 sets the intensity of the notification according to the TTC. This makes it possible to predict in advance the position of the other vehicle A that will cross the loss reference line LL of the host vehicle V and enter, and to provide an appropriate notification while switching the intensity of the notification.

[0058] Furthermore, since the notification means 18 vibrates the engine E, the notification can be perceived by the driver's sense of touch and semicircular canals. This allows the notification to be made without being affected by external factors such as light and sound, regardless of the time of day (intensity of sunlight, number of other vehicles A, darkness such as nighttime), weather, or the driver's condition (drowsy driving). Furthermore, since the notification is made by vibrating the engine E, it is easy to change the intensity of the notification.

[0059] Furthermore, since the saddle-type vehicle (host vehicle V) of this embodiment is equipped with the driving assistance system S, it is possible to provide the driver with a warning based on the level of danger of another vehicle A approaching from behind, thereby realizing an appropriate warning for the driver when changing lanes. Furthermore, since the warning is only issued when the host vehicle V crosses the white line thresholds D1 and D2, it is possible to prevent unnecessary warnings from being issued when the driver has no intention of changing lanes (when the host vehicle V does not cross the white line thresholds D1 and D2 and does not approach the white line L1).

[0060] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be modified as appropriate without departing from the spirit of the present invention. For example, in the above embodiments, the notification means 18 controls the fuel supply system to cause vibration in the engine E, but the present invention is not limited to this. At least one of the rear suspension and the front suspension may be configured to be adjustable to cause pitching that is noticeable to the driver. Furthermore, as an additional configuration of the notification means 18, a light-emitting device that can be recognized by the driver when a notification is issued may be provided.

[0061] In the above embodiment, an example has been described in which the host vehicle V is traveling on the travel path R1 and another vehicle A is approaching from behind on the travel path R2, but the present invention is not limited to this and can be similarly applied to a case in which another vehicle A is approaching from behind on the travel path R1. Also, when the host vehicle V is traveling on the travel path R2 and another vehicle A is approaching from behind on the travel path R1, the only difference is the direction of the lane change, and the present invention can be similarly applied.

[0062] Furthermore, the determination unit 15 uses both the relative distance and relative speed between the vehicle V and the other vehicle A to calculate the TTC, but this is not limited to this, and the TTC may be calculated using at least one of them.

[0063] REFERENCE SIGNS LIST 11 Detection unit 12 Estimation unit 13 Travel direction estimation unit 15 Determination unit 16 Setting unit 17 Virtual line arrival determination unit 18 Notification means 20 Camera A Other vehicle (moving object) D1 White line threshold (virtual line) D2 White line threshold (virtual line) L1 White line (dividing line) L2 Roadway outer line (dividing line) R (R1, R2) Travel path S Driving assistance system for saddle-riding type vehicle (driving assistance system) V Host vehicle (saddle-riding type vehicle)

Claims

1. A driving assistance system for a saddle-type vehicle comprising: a detection unit that detects a roadway on which the vehicle is traveling; a determination unit that determines the movement state of a moving object relative to the vehicle; an estimation unit that estimates the position of the vehicle on the roadway; a setting unit that sets a virtual line inside a dividing line that divides the roadway; and a notification means that, when the estimated position of the vehicle crosses the set virtual line, notifies the driver of the vehicle in a recognizable manner.

2. A driving assistance system for a straddle-type vehicle according to claim 1, further comprising a traveling direction estimation unit that estimates the traveling direction of the vehicle based on the estimated position of the vehicle.

3. A driving assistance system for a straddle-type vehicle according to claim 1, characterized in that the determination unit is also capable of determining the moving object moving from behind the vehicle to the side of the vehicle.

4. A driving assistance system for a saddle-type vehicle as described in claim 1, characterized in that the setting unit sets the virtual line at a position farther away from the lane marking line as the speed at which the vehicle approaches the lane marking line increases.

5. A driving assistance system for a saddle-type vehicle as described in claim 1, characterized in that the setting unit sets the virtual line at a position farther away from the lane markings as the relative speed between the vehicle and the moving object increases.

6. A driving assistance system for a straddle-type vehicle as described in claim 1, characterized in that the detection unit detects the road on which the vehicle is traveling from images captured by a camera.

7. A driving assistance system for a saddle-type vehicle as described in claim 1, characterized in that the estimation unit is capable of identifying the distance between the estimated position of the vehicle and the lane markings of the road detected by the detection unit, the notification means is capable of switching the intensity of the notification, and the notification means sets the intensity of the notification based on the identified distance and the determined movement state of the moving object.

8. A driving assistance system for a saddle-type vehicle as described in claim 1, characterized in that the notification means is capable of switching the intensity of the notification, the determination unit is capable of calculating a value relating to the relative position between the host vehicle and the moving object using at least one of the relative distance between the host vehicle and the moving object and the relative speed between the host vehicle and the moving object, and the notification means sets the intensity of the notification according to the calculated value.

9. A driving assistance system for a straddle-type vehicle according to claim 1, wherein the notification means issues a notification by vibrating the engine of the vehicle.

10. A driving assistance system for a saddle-type vehicle as described in claim 1, characterized in that the estimation unit corrects the estimated position of the vehicle using at least one of the roll angle and yaw angle of the vehicle.

11. A saddle-ride type vehicle comprising a driving assistance system for a saddle-ride type vehicle according to any one of claims 1 to 10.