JP7614074B2 - Saddle type vehicle - Google Patents

Description

The present invention relates to a saddle-type vehicle.

Steering assist devices that control the attitude of a vehicle are known. For example, Patent Document 1 describes a steering assist device for a saddle-type vehicle that can increase the effect of stabilizing the vehicle even in situations where the tires are prone to slipping.

JP 2021-54328 A

However, Patent Document 1 does not disclose any technology for mitigating the impact of a frontal collision of a saddle-type vehicle with an obstacle ahead by controlling the steering wheels with a steering assist device.
The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide a saddle-ride type vehicle that can reduce the risk of a collision.

One aspect of the present invention is a saddle-type vehicle that generates a steering angle at a steering wheel, and includes a steering actuator that applies torque in the steering direction to a suspension device that supports the steering wheel, an actuator control unit that controls the steering actuator, and a collision determination unit that determines whether the front of the vehicle has collided with an obstacle, and the actuator control unit controls the steering actuator to apply a fixing torque to the suspension device so that the steering wheel is fixed in a position facing forward of the vehicle when the collision determination unit determines that the front of the vehicle has collided with the obstacle.

According to one aspect of the present invention, occupants of a saddle-type vehicle can be more appropriately protected in the event of a frontal collision.

FIG. 1 is a side view of a saddle-type vehicle. FIG. 2 is a block diagram showing a configuration of a control system. 4 is a flowchart of steering control in the saddle type vehicle according to the present embodiment. FIG. 4 is an explanatory diagram showing a state in which the steering wheel is fixed during a collision.

Below, an embodiment of the present invention will be described with reference to the drawings. In the description, directions such as front, back, left, right, up and down are the same as directions relative to the vehicle unless otherwise specified. In addition, the symbol FR in each figure indicates the front of the vehicle, the symbol UP indicates the upper side of the vehicle, and the symbol LH indicates the left side of the vehicle.

[Embodiment]
FIG. 1 is a side view of a saddle-ride type vehicle 10 according to an embodiment of the present invention.
The saddle-type vehicle 10 is a vehicle that includes a vehicle frame 11, a power unit 12 supported by the vehicle frame 11, a front fork 14 that supports a front wheel 13 so as to be freely steerable, a swing arm 16 that supports a rear wheel 15, and a seat 17 for a passenger.
The saddle-ride type vehicle 10 is a vehicle in which a passenger sits astride a seat 17. The seat 17 is provided above the rear portion of a vehicle frame 11.

The vehicle frame 11 includes a head pipe 18 provided at the front end of the vehicle frame 11, a front frame 19 located rearward of the head pipe 18, and a rear frame 20 located rearward of the front frame 19. The front end of the front frame 19 is connected to the head pipe 18.
The seat 17 is supported by a rear frame 20 .

The front fork 14 is supported by the head pipe 18 so that it can be steered left and right. The front wheel 13 is supported by an axle 13a provided at the lower end of the front fork 14. A steering handle 21 that is held by the rider is attached to the upper end of the front fork 14.

The swing arm 16 is supported by a pivot shaft 22 that is supported by the vehicle frame 11. The pivot shaft 22 is a shaft that extends horizontally in the vehicle width direction. The pivot shaft 22 is inserted into the front end of the swing arm 16. The swing arm 16 swings up and down about the pivot shaft 22.
The rear wheel 15 is supported by an axle 15 a provided at the rear end of a swing arm 16 .

The power unit 12 is disposed between the front wheels 13 and the rear wheels 15 and is supported by the vehicle frame 11 .
The power unit 12 is an internal combustion engine. The power unit 12 includes a crankcase 23 and a cylinder portion 24 that houses a reciprocating piston. An exhaust device 25 is connected to an exhaust port of the cylinder portion 24.
The output of the power unit 12 is transmitted to the rear wheel 15 by a driving force transmission member that connects the power unit 12 and the rear wheel 15 .

The saddle-type vehicle 10 also includes a front fender 26 that covers the front wheel 13 from above, a rear fender 27 that covers the rear wheel 15 from above, a step 28 on which a rider places his or her feet, and a fuel tank 29 that stores fuel used by the power unit 12.
The front fender 26 is attached to the front fork 14. The rear fender 27 and the step 28 are provided below the seat 17. The fuel tank 29 is supported by the vehicle frame 11.

A ground speed sensor 36 is provided on the front face F of the saddle type vehicle 10 as a detection unit for detecting the ground speed of the vehicle. A millimeter wave radar may be used as the ground speed sensor 36. The ground speed sensor 36 is provided near the headlight at the front of the vehicle, and detects the ground speed of the saddle type vehicle 10 by emitting millimeter wave radio waves M diagonally forward of the vehicle and receiving the reflected waves.
The method for detecting the ground speed may be, for example, a method using microwaves or laser light.

The saddle-ride type vehicle 10 includes a detection unit 32 that detects vehicle behavior information. The vehicle behavior information includes the roll angle, yaw angle, and pitch angle, as well as acceleration and angular velocity, of the saddle-ride type vehicle 10. The detection unit 32 includes an acceleration detection unit 41 that detects acceleration components in the front-rear direction and acceleration components in the left-right direction of the vehicle, and a roll angle detection unit 43 that detects a roll angle.
The detection unit 32 is, for example, an inertial measurement unit (IMU) that detects translational motion and rotational motion in a plurality of directions that are perpendicular to each other.

A control device 34 is provided below the seat 17, which performs processing including measuring ground speed. The control device 34 is, for example, an ECU (Electronic Control Unit). The control device 34 is equipped with a CPU (Central Processing Unit), RAM (Random Access Memory), and ROM (Read Only Memory), and performs various controls. The CPU is a central processing unit, and realizes various functions by executing various programs. The RAM is used as a working area and storage area for the CPU, and the ROM stores the operating system and programs executed by the CPU.

Figure 2 is a block diagram showing the configuration of the control system 1 in the saddle-ride type vehicle 10 according to this embodiment. The control device 34 has a data transmission/reception unit 42 including an interface circuit for transferring data between the CPU and other devices, and a storage unit 44 for storing data. The storage device provided in the storage unit 44 may be, for example, an SSD (Solid State Device).

The collision determination unit 40 determines whether or not the vehicle 10 has collided at the front F. The CPU realizes the function of the collision determination unit 40 by executing a program stored in the storage unit 44. The collision determination unit 40 determines that the vehicle 10 has collided at the front F when the detection unit 32 detects a physical amount that is displaced when the vehicle 10 collides at the front F. Details of the determination process will be described later.
In addition, the CPU, by executing a program stored in the memory unit 44, realizes the function of an actuator control unit 46 that controls the steering actuator 30 that applies torque in the steering direction to the suspension device 31 that supports the front wheels 13, which are the steered wheels.

The control device 34 is connected via a data transmission/reception unit 42 to a ground speed sensor 36, which is a ground speed detection unit that detects the ground speed of the vehicle 10, the steering actuator 30, a detection unit 32 that detects behavior information of the vehicle 10, and a steering torque detection unit 38 that detects the magnitude of the steering torque input by the occupant U to the suspension device 31 through the steering wheel 21.

Figure 3 is a flowchart showing the steering control of the control system 1 in the saddle-ride type vehicle 10 according to this embodiment.

The saddle-ride type vehicle 10 generates a steering angle in the front wheels 13, which are steered wheels, by swinging the vehicle 10 in the roll direction. The vehicle 10 is equipped with a steering actuator 30 that applies torque in the steering direction to a suspension device 31 that supports the front wheels 13, an actuator control unit 46 that controls the steering actuator 30, and a collision determination unit 40 that determines whether a collision has occurred at the front face F of the vehicle. If the collision determination unit 40 determines that a collision has occurred at the front face F of the vehicle, the actuator control unit 46 controls the steering actuator 30 to apply a fixing torque so that the front wheels 13 are fixed toward the front FR of the vehicle.

First, the control system 1 detects the ground speed using the ground speed sensor 36. The control system 1 detects vehicle behavior information using the IMU (detection unit) 32 (step SA1). The ground speed information and the vehicle behavior information detected by the IMU 32 are received by the control device 34 via the data transmission/reception unit 42. The collision determination unit 40 of the control device 34 compares the detected ground speed with a first threshold value that has been set in advance and stored in the memory unit 44, and determines whether the value of the ground speed is greater than the first threshold value (step SA2). For example, the first threshold value is 40 km/h. When the saddle-type vehicle 10 collides with a collision target from the front F in an upright state, if the control device 34 performs control to fix the front wheel 13 in the forward FR direction of the vehicle at the time of collision, a gap is more likely to be created between the occupant and the collision target, thereby reducing the collision. However, at low speeds, such as 5 km/h, the impact caused by a collision is relatively small, so it is preferable for the control system 1 not to interfere with the driver's steering operation.

If the ground speed is equal to or less than the set first threshold value (step SA1: NO), the processing of the control system 1 returns to step SA1.
In other words, the actuator control section 46 performs control based on the ground speed so as not to apply a fixing torque that fixes the steering angle of the steered wheels 13 .

If the value of the ground speed is greater than the first threshold (step SA2: YES), the collision determination unit 40 compares the roll angle detected by the roll angle detection unit 43 of the IMU 32 with a second threshold value previously set and stored in the memory unit 44 to determine whether the roll angle is smaller than the second threshold value (step SA3). For example, the second threshold value is 10 degrees. Here, the roll angle is the attitude angle of the vehicle, and is an angle of rotation around a straight line that is parallel to the front-rear direction of the saddle-ride type vehicle 10 and passes through the center of gravity of the vehicle as the central axis. If the detected roll angle is smaller than the second threshold value (step SA3: YES), the collision determination unit 40 determines that the saddle-ride type vehicle 10 is upright and traveling forward. Specifically, if the roll angle is large, for example, if the roll angle is 45 degrees and a collision occurs while turning, it is difficult to predict how the vehicle will behave if the control system 1 controls the front wheels 13 by the actuator control unit 46 to fix them at an angle at which the steering wheel is not turned, i.e., in the center position, at the time of the collision. For this reason, it is preferable that the control device 34 not perform control to lock the front wheels 13 in the event of a collision.

If the roll angle is equal to or greater than the set second threshold value (step SA3: NO), the process of the control system 1 returns to step SA1.
In other words, the actuator control unit 46 performs control based on the roll angle so as not to apply a fixing torque that fixes the steering angle of the steered wheels 13 .

If the detected roll angle is smaller than the second threshold (step SA3: YES), the collision determination unit 40 compares the magnitude of the steering torque detected by the steering torque detection unit 38 with a third threshold value that has been set in advance and stored in the memory unit 44 to determine whether the steering torque is smaller than the third threshold value (step SA4). For example, the third threshold value is 10 Nm. If the steering torque by the occupant U is large, for example, if the steering torque is 10 Nm or more, it is considered that the occupant U intentionally turned the wheel. Therefore, in that case, it is preferable that the control device 34 does not interfere with the steering operation.

If the steering torque is equal to or greater than the third threshold (step SA4: NO), the control system 1 returns to step SA1.

In other words, the actuator control unit 46 performs control so as not to apply a fixing torque that fixes the steering angle of the steered wheels 13, based on the magnitude of the steering torque applied to the suspension device 31 by the occupant U of the vehicle 10.

If the magnitude of the steering torque is smaller than the third threshold (step SA4: YES), the control device 34 acquires the vehicle's longitudinal acceleration from the vehicle behavior information detected by the IMU 32. The collision determination unit 40 compares the acquired longitudinal acceleration with a fourth threshold that is preset and stored in the memory unit 44 to determine whether the longitudinal acceleration is smaller than the fourth threshold. For example, the fourth threshold is -1.5G. Specifically, when the longitudinal acceleration when the vehicle speed is accelerating is expressed as a positive value and the longitudinal acceleration when the vehicle speed is decelerating is expressed as a negative value, a longitudinal acceleration smaller than -1.5G is considered to indicate that a collision has occurred at the front face F of the vehicle. Therefore, this determination makes it possible to determine whether a collision has occurred at the front face F of the saddle-ride type vehicle 10.

In other words, the collision determination unit 40 determines whether the front face F of the vehicle 10 has collided with an obstacle based on the acceleration of the vehicle 10 in the forward/rearward and left/right directions while the vehicle 10 is traveling.

If the forward/rearward acceleration is -1.5 G or greater (step SA5: NO), the control system 1 returns to step SA1.

When the longitudinal acceleration is compared with a fourth threshold value that is preset and stored in the memory unit 44, and the longitudinal acceleration is smaller than the fourth threshold value (step SA5: YES), the control unit 34 acquires the lateral acceleration of the vehicle from the vehicle behavior information detected by the detection unit 32. Here, for the lateral acceleration of the vehicle, if the leftward direction as viewed from the front of the saddle type vehicle 10 is expressed as positive and the rightward direction as viewed from the front is expressed as negative, the collision determination unit 40 compares the absolute value of the lateral acceleration with a fifth threshold value that is preset and stored in the memory unit 44, and determines whether the absolute value of the lateral acceleration is smaller than the fifth threshold value (step SA6). For example, the fifth threshold value is 0.5 G.

If the absolute value of the acquired lateral acceleration is smaller than the fifth threshold value (step SA6: YES), the control device 34 controls the steering actuator 30 via the actuator control section 46 to fix the front wheels 13 facing forward (step SA7).
In other words, the vehicle 10 is equipped with a steering actuator 30 that applies a torque in the steering direction to a suspension device 31 that supports the steered wheels 13, an actuator control unit 46 that controls the steering actuator 30, and a collision judgment unit 40 that determines whether or not the front face F of the vehicle 10 has collided with an obstacle, and when the collision judgment unit determines that the front face F of the vehicle 10 has collided with an obstacle, the actuator control unit 46 controls the steering actuator 30 to apply a fixing torque to the suspension device 31 so that the steered wheels 13 are fixed in a position facing the forward FR of the vehicle.

When the left-right acceleration is small during a collision, it is considered to mean that the front face F of the vehicle 10 and the object of collision collide at an angle close to perpendicular. When a collision occurs at an angle close to perpendicular, if the control device 34 controls the front wheels 13 to be fixed in the center, a gap is likely to be created between the occupant U and the object of collision, and the collision is mitigated. Conversely, when the left-right acceleration is large during a collision, it means that an external force is applied to the vehicle 10 in the lateral direction. When an external force is applied in the lateral direction, it is difficult to predict how the vehicle 10 will behave if a fixing torque is applied to the suspension device 31 to fix the front wheels 13 toward the front of the vehicle 10 during a collision. Therefore, in such a case, it is preferable that the control device 34 does not control the front wheels 13 to be fixed during a collision.

If the absolute value of the left-right acceleration is 0.5 G or greater (step SA6: NO), the control system 1 returns to step SA1.

In summary, when the ground speed condition, roll angle condition, and steering torque condition are met, the collision determination unit 40 determines that a collision has occurred at the front F of the vehicle 10 if the acceleration in the longitudinal direction of the vehicle 10 is less than a preset fourth threshold value and the absolute value of the acceleration in the lateral direction of the vehicle 10 is less than a preset fifth threshold value, and the actuator control unit 46 controls the steering actuator 30 to apply a fixed torque to the suspension device 31.

Figure 4 is an explanatory diagram showing how the control system 1 fixes the steering wheels in a saddle-ride type vehicle 10 during a collision. Figure 4 shows a case where the vehicle 10 collides with the side of vehicle A. At this time, a rearward force is applied to the vehicle 10, and if the force is large, the saddle-ride type vehicle 10 may tilt with the rear wheels lifted off the ground as shown in Figure 4. At this time, it is desirable for the distance between the occupant U and the vehicle A that is the object of collision to be large. The control system 1 of the vehicle 10 controls the steering actuator 30 attached to the suspension device 31 by the actuator control unit 46, and applies a fixing torque to the front wheels 13 to fix them so that they face the front FR of the vehicle. Therefore, the distance d between the axle 13a and the front part of the front wheels 13 is secured, and it is easy to maintain a large distance between the occupant U and the vehicle A that is the object of collision.

(Configuration supported by the above embodiment)
The above embodiment supports the following configurations.

(Configuration 1) A saddle-ride type vehicle that generates a steering angle on a steering wheel, comprising: a steering actuator that applies torque in the steering direction to a suspension device that supports the steering wheel; an actuator control unit that controls the steering actuator; and a collision judgment unit that determines whether the front of the vehicle has collided with an obstacle, wherein when the collision judgment unit determines that the front of the vehicle has collided with the obstacle, the actuator control unit controls the steering actuator to apply a fixing torque to the suspension device so that the steering wheel is fixed in a position facing forward of the vehicle.
According to this configuration, when the saddle type vehicle is hit by a frontal collision, it becomes easier to maintain a distance between the occupant and the object of the collision, which has the effect of more appropriately protecting the occupant from the collision.

(Configuration 2) The saddle-type vehicle described in Configuration 1, further comprising an acceleration detection unit that detects the acceleration of the vehicle, and a collision determination unit that determines whether or not the front of the vehicle has collided with the obstacle based on the acceleration in each of the forward/rearward and left/right directions of the vehicle while the vehicle is traveling.
It is preferable that the control of applying a fixing torque to the suspension device supporting the steering wheel by the steering actuator to fix the steering wheel facing in the vehicle forward direction be limited to when the vehicle is colliding from the front. Furthermore, in a collision in which an external force is applied in the lateral direction of the vehicle, it is not possible to predict the behavior of the vehicle when a fixing torque is applied to the suspension device, and therefore it is preferable not to apply a fixing torque to the suspension device under such conditions. With this configuration, it is possible to apply a fixing torque to the suspension device only when the vehicle collides with an obstacle from the front. This has the effect of more appropriately protecting the occupants from a collision.

(Configuration 3) A saddle-type vehicle as described in Configuration 1 or 2, further comprising a steering torque detection unit that detects the magnitude of steering torque input to the suspension device by an occupant of the vehicle, and the actuator control unit performs control not to apply the fixing torque that fixes the steering angle of the steered wheel based on the magnitude of the steering torque input to the suspension device by the occupant of the vehicle.
When the steering torque applied to the steering wheels by the occupant is large, there is a high possibility that the occupant is intentionally steering. With this configuration, in a situation where it is considered that the occupant is intentionally steering, the control device has the effect of not interfering with the steering operation by the occupant.

(Configuration 4) A saddle-type vehicle as described in any one of Configurations 1 to 3, further comprising a ground speed detection unit that detects a ground speed, and the actuator control unit performs control not to apply the fixing torque that fixes the steering angle of the steering wheel based on the ground speed.
When the ground speed is low, the damage to the occupants in a collision is unlikely to be serious. Fixing the steering wheel at the front of the vehicle by applying a fixed torque to the suspension system may cause the vehicle to behave in a way that exceeds the occupants' expectations. This configuration limits the condition for applying a fixed torque to the suspension system to when a collision occurs at a relatively high ground speed, thereby providing the effect of more appropriately protecting the occupants from a collision.

(Configuration 5) A saddle-type vehicle as described in any one of Configurations 1 to 4, further comprising a roll angle detection unit that detects a roll angle of the vehicle, and the actuator control unit performs control not to apply the fixing torque that fixes the steering angle of the steered wheel based on the roll angle.
A large roll angle means that the saddle-type vehicle is turning. If a fixed torque is applied to the suspension device when the vehicle is turning and a collision occurs, the vehicle may behave in an unexpected manner. With this configuration, a fixed torque is not applied to the suspension device when the roll angle of the vehicle is large, so that the vehicle can be protected from a collision more appropriately without causing the vehicle to behave in an unexpected manner.

10. Saddle-type vehicle (vehicle)
13 Front wheels (steering wheels)
30 Steering actuator 31 Suspension device 32 IMU (detection unit)
34 Control device 36 Ground speed sensor (ground speed detection unit)
38 Steering torque detector 41 Acceleration detector 43 Roll angle detector 46 Actuator controller F Front U Occupant

Claims (5)

A saddle-type vehicle that generates a steering angle on a steering wheel (13),
a steering actuator (30) that applies torque in a steering direction to a suspension device (31) that supports the steering wheel (13);
an actuator control unit (46) for controlling the steering actuator (30);
a collision determination unit (40) that determines whether or not the front (F) of the vehicle (10) has collided with an obstacle;
The actuator control unit (46) controls the steering actuator (30) to apply a fixing torque to the suspension device (31) so that the steering wheel (13) is fixed in a position facing the front (FR) of the vehicle when the collision determination unit (40) determines that the front (F) of the vehicle (10) has collided with the obstacle. An acceleration detection unit (41) for detecting an acceleration of the vehicle (10),
The saddle-type vehicle according to claim 1, further comprising a collision determination unit (40) that determines whether or not the front (F) of the vehicle (10) has collided with the obstacle based on the acceleration of the vehicle (10) in the forward/rearward direction and the left/right direction while the vehicle (10) is traveling. a steering torque detection unit (38) for detecting a magnitude of a steering torque input to the suspension device (31) by an occupant (U) of the vehicle (10),
3. The saddle-type vehicle according to claim 1, wherein the actuator control unit (46) performs control not to apply the fixing torque that fixes the steering angle of the steering wheel (13) based on the magnitude of the steering torque applied to the suspension device (31) by an occupant (U) of the vehicle (10). A ground speed detection unit (36) for detecting a ground speed is provided,
4. The saddle-type vehicle according to claim 1, wherein the actuator control unit (46) performs control not to apply the fixing torque that fixes the steering angle of the steering wheel (13) based on the ground speed . A roll angle detection unit (43) is provided to detect a roll angle of the vehicle (10),
5. The saddle-type vehicle according to claim 1, wherein the actuator control unit (46) performs control not to apply the fixing torque that fixes the steering angle of the steering wheel (13) based on the roll angle .

Images