WO2021065745A1 - Steering assistance device for straddle type vehicle - Google Patents

Abstract

In the steering assistance device for a straddle type vehicle according to the present invention, when an external detection means detects an obstacle (other vehicle (T)) in front of an own vehicle M, a control means carries out automatic brake control which actuates a brake without an operation by a driver, while controlling a braking force of the automatic brake control according to a preset control parameter (relative time distance). During hard brake control in the case of the control parameter being greater than a preset threshold (t3), behavior stabilizing control by means of assist steering control is strengthened compared to during the control in the case of the control parameter being no greater than the threshold (t3).

Description

Steering assist device for saddle-riding vehicles

The present invention relates to a steering assist device for a saddle-riding vehicle.
The present application claims priority based on Japanese Patent Application No. 2019-179928 filed on September 30, 2019, the contents of which are incorporated herein by reference.

According to Patent Document 1, in a control device that assists parking of a passenger vehicle, the direction of steering operation by the driver is the same as the avoidance direction for avoiding contact with an obstacle, and the direction opposite to the avoidance direction. It is disclosed that the direction or magnitude of the steering torque generated by the steering actuator differs depending on the case. As a result, the steering torque generated by the steering actuator assists the avoidance of contact with obstacles, and the steering operation can be performed according to the driver's intention without being disturbed by the steering torque generated by the actuator.

Japanese Patent Application Laid-Open No. 2008-55985

By the way, in the above-mentioned prior art, there is no disclosure about an appropriate assist steer when the driving support system of a saddle-riding vehicle is activated. For example, there is a demand for appropriate control during system operation such as collision mitigation braking, lane departure warning, and blind spot information.

According to the aspect of the present invention, in a steering assist device for a saddle-riding vehicle in which a vehicle body is rolled to generate a steering angle on the steering wheels, appropriate assist steering control is performed when the driving support system is activated.

(1) The steering assist device for a saddle-riding vehicle according to the present invention is the steering assist device for a saddle-riding vehicle in which the vehicle body is swung in the roll direction to generate a steering angle on the steering wheels. A steering actuator that applies an assist torque to a suspension device that supports the vehicle, a control means that drives and controls the steering actuator, and an external detection means that detects a situation around the vehicle are provided, and the control means is the external detection means. When an obstacle is detected in front of the vehicle, automatic brake control is performed to operate the brake regardless of the driver's operation, and the braking strength of the automatic brake control is adjusted according to predetermined control parameters. At the time of strong brake control when the control parameter exceeds a predetermined threshold value, the behavior stabilization control by the assist steering control is strengthened as compared with the control time when the control parameter does not exceed the threshold value.

(2) In the aspect of (1) above, the control means may set a plurality of stages of brake strength and a plurality of threshold values corresponding to each brake strength in the automatic brake control, and the control parameter is the first. When one threshold is exceeded, a relatively weak first brake control is performed, and when the control parameter exceeds the second threshold, a relatively strong second brake control is performed, and behavior stabilization control by the assist steer control is performed. You may strengthen it.

(3) In the aspect of (2) above, the control means does not strengthen the behavior stabilization control during the first brake control, or controls the behavior stabilization within a range of output weaker than that during the strong brake control. You may strengthen it.

According to the aspect (1) above, while the driving support system detects an obstacle in front of the vehicle, automatic braking control is performed when the approach of the obstacle is detected based on the obstacle detection information. When the driver unintentionally operates the steering wheel due to the automatic brake control, the behavior of the vehicle becomes large and the stability is affected. Therefore, during strong brake control when the control parameter that determines the brake strength of automatic brake control exceeds the threshold value, assist is performed compared to control when the control parameter does not exceed the threshold value (when weak brake control or no brake control). The behavior stabilization control is strengthened by strengthening the torque. In this way, it is possible to carry out appropriate assist steering control according to the braking strength of the automatic brake control, and it is possible to enhance the effect of the driving support system.
According to the aspect (2) above, in the configuration in which the brake strength and the threshold value of a plurality of stages are set for the automatic brake control, the assist torque is strengthened at the time of the strong brake control at the stage where the control parameter exceeds the second threshold value. Strengthen behavior stabilization control. As a result, it is possible to carry out assist steering control with less discomfort to the driver.
According to the aspect (3) above, in a configuration in which a plurality of stages of brake strength and threshold value are set for automatic brake control, the control parameter is the first threshold value during weak brake control at a stage where the control parameter exceeds the first threshold value. The behavior stabilization control is not strengthened or the behavior stabilization control is strengthened with a weaker output than when the strong brake control is performed, as compared with the control at the stage where the above is not exceeded (when there is no brake control, etc.). As a result, it is possible to gradually strengthen the behavior stabilization control up to the strong brake control, and it is possible to carry out the assist steer control with less discomfort to the driver.

It is a left side view of the motorcycle in embodiment of this invention. It is a block diagram of the control device of the motorcycle. It is a block diagram of the steering assist device of the motorcycle. It is a block diagram of the wobbling suppression assist torque calculation block of the steering assist device. It is a V arrow view of FIG. It is a table which shows the warning example by function of the above-mentioned motorcycle driving support system, and the trigger plan when shifting to high stabilization control. It is explanatory drawing of the warning threshold value of the collision mitigation brake of the said driving support system. It is explanatory drawing of the warning threshold of the lane departure warning of the said driving support system. It is explanatory drawing of the warning threshold value of the blind spot information of the said driving support system. It is a graph which shows the relationship between the assist strength of the steering assist device, and a vehicle speed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The orientations of the front, rear, left, right, etc. in the following description shall be the same as the orientations in the vehicle described below unless otherwise specified. An arrow FR indicating the front of the vehicle, an arrow LH indicating the left side of the vehicle, an arrow UP indicating the upper part of the vehicle, and a line CL indicating the center of the left and right sides of the vehicle body are shown at appropriate positions in the drawings used in the following description.

<Whole vehicle>
As shown in FIG. 1, this embodiment is applied to a motorcycle (saddle-riding vehicle) 1 provided with a large cowling. The front wheel 2 of the motorcycle 1 is supported by the front wheel suspension device 3. The front wheel suspension device 3 is supported by the front end portion of the vehicle body frame 5. A front block 6 for supporting the front wheel suspension device 3 is provided at the front end portion of the vehicle body frame 5. A bar handle 4 for steering the front wheels is attached to the upper part of the front block 6. The bar handle 4 includes a pair of left and right grips gripped by the rider (driver) J.

Behind the front block 6, a pair of left and right mainframes 7 extend diagonally downward and rearward. The rear ends of the left and right main frames 7 are connected to the upper ends of a pair of left and right pivot frames 8, respectively. A power unit U including, for example, a horizontally opposed six-cylinder engine is mounted below the left and right main frames 7 and in front of the left and right pivot frames 8.

The front end portion of the swing arm 11 is supported by the left and right pivot frames 8. The rear wheel 12 of the motorcycle 1 is supported at the rear end of the swing arm 11. A rear cushion (not shown) is interposed between the front portion of the swing arm 11 and the front / rear intermediate portion of the vehicle body frame 5.

The front end of the rear frame 9 is connected to the rear of the left and right pivot frames 8. A seat 14 for seating an occupant is arranged above the rear frame 9. A fuel tank 15 is arranged below the seat 14. A rear trunk 16 is arranged behind the seat 14. Left and right saddle bags 17 are arranged on both left and right sides below the rear trunk 16.

The motorcycle 1 includes a front wheel brake 2B for braking the front wheel 2 and a rear wheel brake 12B for braking the rear wheel 12. The front and rear brakes 2B and 12B are hydraulic disc brakes, respectively. The motorcycle 1 includes a brake actuator 42 (see FIG. 5) that supplies and discharges hydraulic pressure to the front and rear brakes 2B and 12B. The motorcycle 1 constitutes a bi-wire type brake system in which the front and rear brakes 2B and 12B and brake operators such as a brake lever and a brake pedal operated by the rider J are electrically linked.

<Front wheel suspension device>
The front wheel suspension device 3 includes a handle support portion 6a, a handle post 4a, a head pipe 3a, a front fork member 3b, a steering member 3c, a link member 4b, a swing arm 3d, a cushion unit 3e, and the like. It has. The handle support portion 6a is provided at the upper end portion of the front block 6. The handle post 4a is rotatably supported by the handle support portion 6a. The head pipe 3a is provided separately from the vehicle body frame 5. The front fork member 3b is rotatably supported by the head pipe 3a. The steering member 3c is integrally rotatably attached to the upper end portion of the front fork member 3b. The link member 4b connects the steering member 3c and the handle post 4a. The swing arm 3d swingably connects the head pipe 3a to the front block 6. The cushion unit 3e is interposed between the front fork member 3b and the front block 6.

The front fork member 3b supports the front wheel 2 at the lower ends of the left and right forks. A steering shaft is integrally provided at the upper end of the front fork member 3b, and the steering shaft is inserted and supported by the head pipe 3a. The upper end of the steering shaft projects above the head pipe 3a, and the steering member 3c is attached to the upper end.

Hereinafter, the rotation center axis of the handle post 4a with respect to the handle support portion 6a will be referred to as a handle rotation axis C2. The rotation center axis of the front fork member 3b with respect to the head pipe 3a is referred to as a steering axis C3. The steering axis C3 is offset (separated) forward from the steering wheel rotation axis C2. The steering axis C3 and the steering wheel rotation axis C2 are substantially parallel to each other in the 1G state of the vehicle.

FIG. 5 is an arrow view taken from the direction of the arrow V along the steering axis C3 and the steering wheel rotation axis C2 in FIG. In FIG. 5, the link member 4b forms a parallel link together with the steering member 3c and the handle post 4a. As a result, the steering angle of the bar handle 4 and the steering angle of the front wheels 2 become the same as each other.

With reference to FIG. 1, the front end portion of the swing arm 3d is supported by the head pipe 3a so as to be swingable up and down. The rear end portion of the swing arm 3d is supported by the front block 6 so as to be swingable up and down. The swing arm 3d includes a pair of upper and lower arm members. The swing arm 3d enables the head pipe 3a to move up and down along a specified trajectory. For example, the lower end of the cushion unit 3e is connected to the lower arm member.

The front wheel suspension device swings the swing arm 3d upward to move the front fork member 3b and the head pipe 3a upward. At this time, the lower arm member moves the lower end portion of the cushion unit 3e upward to compress the cushion unit 3e.
The front wheel suspension device swings the swing arm 3d downward to move the front fork member 3b and the head pipe 3a downward. At this time, the lower arm member moves the lower end portion of the cushion unit 3e downward to extend the cushion unit 3e.

<Control device>
FIG. 2 is a configuration diagram of the control device 23 of the motorcycle 1 according to the present embodiment.
The motorcycle 1 includes a control device 23 that controls the operation of the various devices 22 based on the detection information acquired from the various sensors 21. The control device 23 is configured as, for example, an integral or a plurality of electronic control units (ECUs: Electronic Control Units). The control device 23 may be realized at least in part by the cooperation of software and hardware. The control device 23 includes a fuel injection control unit, an ignition control unit, and a throttle control unit that control the operation of the engine 10. The motorcycle 1 constitutes a bi-wire engine control system in which an engine auxiliary device such as a throttle device 48 and an accelerator operator such as an accelerator grip operated by a rider J are electrically linked.

The various sensors 21 include a throttle sensor 31, a wheel speed sensor 32, a brake pressure sensor 33, a vehicle body acceleration sensor 34, a steering angle sensor 35, a steering torque sensor 36 and a vehicle speed sensor 37, and an external detection means 38. ..
The various sensors 21 detect various operation inputs of the rider J, various states of the motorcycle 1 and the occupants, and the situation around the own vehicle. The various sensors 21 output various detection information to the control device 23.

The throttle sensor 31 detects the amount of operation (acceleration request) of the accelerator operator such as the throttle grip.
The brake pressure sensor 33 detects the operating force (deceleration request) of the brake operator.
The vehicle body acceleration sensor 34 is a 5-axis or 6-axis IMU (Inertial Measurement Unit). The vehicle body acceleration sensor 34 detects the angular velocities and accelerations of the three axes (roll axis, pitch axis, yaw axis) in the vehicle body, and further detects the angle from the results. Hereinafter, the vehicle body acceleration sensor 34 may be referred to as a vehicle body angular velocity sensor 34.
The steering angle sensor 35 is, for example, a potentiometer provided on a steering shaft (steering shaft or steering wheel rotation shaft). The steering angle sensor 35 detects the rotation angle (steering angle) of the steering shaft with respect to the vehicle body.

The steering torque sensor 36 is, for example, a magnetostrictive torque sensor provided on the steering shaft (or the rotation shaft of the handle post 4a) of the fork member 3b. The steering torque sensor 36 detects the torsional torque (steering input) input from the bar handle 4. The steering torque sensor 36 is an example of a load sensor that detects a steering force input to the bar handle 4 (steering operator).

In the front wheel suspension device 3 of the embodiment, the rotation shaft of the handle post 4a that supports the bar handle 4 and the steering shaft that enables the front wheel 2 to be steered are separate from each other, but the present invention is not limited to this. For example, the steering wheel rotation shaft and the steering shaft (front wheel rotation shaft) may be the same as each other, as in a general front wheel suspension device. The front wheel suspension device may be supported by the head pipe at the front end of the vehicle body frame 5.

The external detection means 38 includes, for example, a camera, a radar device, a finder, and an object recognition device.
The camera is, for example, a digital camera using a solid-state image sensor such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). The camera is attached to any part of the motorcycle 1. When photographing the front, the camera is attached to a vehicle body part (including a steering side and a non-steering side), various exterior parts, and the like. The camera periodically and repeatedly images the periphery of the motorcycle 1 (for example, front, back, left, and right). The image captured by the camera is subjected to appropriate image processing to become desired image data, which is used for various controls. The information from the camera is used for recognizing the position, type, speed, etc. of the object in the detection direction, and based on this recognition, the driving assist control, the automatic driving control, and the like of the motorcycle 1 are performed. For example, the camera may be a camera that captures not only visible light but also invisible light such as infrared light.

The radar device radiates radio waves such as millimeter waves around the motorcycle 1 and detects radio waves (reflected waves) reflected by the object to at least detect the position (distance and orientation) of the object. The radar device is attached to any part of the motorcycle 1. The radar device detects the position and speed of the front, rear, left, and right objects of the motorcycle 1.

The finder is LIDAR (Light Detection and Ringing). The finder irradiates the periphery of the motorcycle 1 with light and measures the scattered light. The finder detects the distance to the target based on the time from light emission to light reception. The emitted light is, for example, a pulsed laser beam. The finder can be attached to any part of the motorcycle 1.

The object recognition device performs sensor fusion processing on the detection results of a part or all of the camera, radar device, and finder, and recognizes the position, type, speed, etc. of the object. The object recognition device outputs the recognition result to the control device 23. The object recognition device may output the detection results of the camera, the radar device, and the finder to the control device 23 as they are. The object recognition device may be omitted.

An automatic driving system is adopted for the motorcycle 1.
Here, there are the following degrees in the automatic driving of the vehicle. The degree of automatic driving can be determined by, for example, a scale such as whether it is less than a predetermined standard or more than a predetermined standard. The degree of automatic driving is less than the specified standard, for example, when manual driving is being executed, or only driving support devices such as ACC (Adaptive Cruise Control System) and LKAS (Lane Keeping Assistance System) are operating. The case. An operation mode in which the degree of automatic operation is less than a predetermined reference is an example of the "first operation mode".

The degree of automatic driving exceeds a predetermined standard, for example, when a driving support device such as ALC (Auto Lane Changing) or LSP (Low Speed Car Passing), which has a higher degree of control than ACC or LKAS, is operating. Alternatively, it is a case where automatic driving that automatically changes lanes, merges, and branches is being executed. An operation mode in which the degree of automatic operation is equal to or higher than a predetermined reference is an example of a "second operation mode".
The above "predetermined standard" can be set arbitrarily. It is assumed that the first operation mode is manual operation and the second operation mode is automatic operation. This embodiment is applied to the driving assist control (driving support system) corresponding to the first driving mode, but may be applied to the automatic driving control.

With reference to FIG. 2, various devices 22 include an engine control means 45, a brake actuator 42, and a steering actuator 43.
The engine control means 45 includes a fuel injection device 46, an ignition device 47, a throttle device 48, and the like. That is, the engine control means 45 includes an engine auxiliary machine for driving the engine 10.

The brake actuator 42 supplies hydraulic pressure to the front and rear brakes 2B12B in response to an operation on the brake operator to operate them. The brake actuator 42 also serves as a control unit for ABS (Anti-lock Brake System).

The steering actuator 43 outputs steering torque to the steering mechanism from the bar handle 4 to the fork member 3b. The steering actuator 43 operates an electric motor, which is its own drive source, in response to the detection information of the steering torque sensor 36, and applies an assist torque to the steering mechanism. The steering actuator 43 includes an ST-ECU that electrically controls the operation of the electric motor.

With reference to FIG. 5, the steering actuator 43 is arranged on the left side of the steering wheel support portion 6a and attached to the vehicle body frame 5. The steering actuator 43 is arranged so that the drive shaft 43a of the electric motor is parallel to the steering wheel rotation shaft. A swing arm 43b is integrally rotatably attached to the drive shaft 43a. The swing arm 43b is connected to the actuator connecting portion 4a1 of the handle post 4a via a connecting rod 43c. As a result, the driving force (torque) of the electric motor can be transmitted to the handle post 4a, and the steering of the front wheels 2 is assisted.
<Steering assist control>

With reference to FIG. 1, the vehicle body acceleration sensor 34 is supported by the vehicle body of the motorcycle 1 (for example, the vehicle body frame 5). For example, the vehicle body acceleration sensor 34 is arranged in the vicinity of the line segment L connecting the ground contact point Gp of the rear wheel 12 and the substantially central portion of the head pipe 3a in a side view. The vehicle body acceleration sensor 34 detects the angular velocity Y in the yaw direction and the angular velocity R in the roll direction of the motorcycle 1. Hereinafter, the angular velocity Y in the yaw direction may be referred to as a yaw rate Y. The vehicle body of the embodiment includes not only the vehicle body frame 5 but also a configuration that integrally performs behaviors such as rolling, pitching, and yawing with the vehicle body frame 5.

At low speeds of the motorcycle 1, it has the characteristic that the bank (roll) of the vehicle body is generated after the steering (yaw) is generated by the operation of the bar handle 4. That is, when the motorcycle 1 has a low speed, yaw is generated in advance, so it is preferable to detect a large yaw angular velocity Y. On the other hand, at high speeds of the motorcycle 1, the motorcycle has a characteristic that the steering (yaw) is generated after the bank (roll) of the vehicle body is generated. That is, at the high speed of the motorcycle 1, the roll is generated in advance, so it is preferable to detect a large roll angular velocity R. This characteristic is referred to as a steering characteristic of the motorcycle 1.

With reference to FIG. 4, the control device 23 synthesizes the yaw angular velocity Y and the roll angular velocity R detected by the vehicle body acceleration sensor 34 to generate the combined angular velocity S. The control device 23 synthesizes the yaw angular velocity Y and the roll angular velocity R detected by the vehicle body acceleration sensor 34 by changing the weights as follows according to the detected vehicle speed V. That is, from the steering characteristics of the motorcycle 1 described above, when the vehicle speed V is low, the weight of the yaw angular velocity Y is combined to be larger than the roll angular velocity R, and when the vehicle speed V is high, the weight of the roll angular velocity R is larger than the yaw angular velocity Y. And synthesize.

For the generation of the composite angular velocity S, for example, as shown in the following equation (1), a value (Y × AD1) obtained by multiplying the yaw angular velocity Y by the first adjustment value AD1 and a second adjustment value AD2 for the roll angular velocity R are used. The composite angular velocity S may be generated by adding the multiplied value (R × AD2).
S = Y × AD1 + R × AD2 ... (1)

In this case, the first adjustment value AD1 is set to be large on the low speed side and small on the high speed side, and the second adjustment value AD2 is set to be small on the low speed side and large on the high speed side.

FIG. 3 is a configuration diagram of the steering assist device 50.
The steering assist device 50 includes a steering torque sensor 36, a vehicle speed sensor 37, a vehicle body angular velocity sensor 34, an external detection means 38, a control device 23, and a steering actuator 43.

The vehicle speed sensor 37 detects, for example, the rotation speed of the output shaft of the power unit U of the motorcycle 1, and detects the rotation speed of the rear wheels 12 and thus the vehicle speed of the motorcycle 1 from this rotation speed. The vehicle speed may be detected by obtaining wheel speed information from at least one of ABS and TCS (Traction Control System).

The control device 23 includes a power assist torque calculation block 00, a wobble suppression assist torque calculation block 300, and an applied torque calculation unit 400. Each block 00, 300 can operate independently, or can operate as a whole.

The power assist torque calculation block 00 calculates the power assist torque Tp to be applied to the bar handle 4 based on the vehicle speed V and the steering torque Ts. The vehicle speed V is calculated from the detection information of the vehicle speed sensor 37, that is, the rotation speed of the driving wheels (rear wheels 12). The steering torque Ts corresponds to the input torque to the bar handle 4 by the driver and is calculated from the detection information of the steering torque sensor 36. The power assist torque Tp is a torque for reducing the steering of the driver's bar handle 4.

The wobble suppression assist torque calculation block 300 calculates the wobble suppression assist torque Tw applied to the bar handle 4 based on the vehicle speed V, the yaw angular velocity Y, and the roll angular velocity R. The yaw angular velocity Y and the roll angular velocity R are calculated from the detection information of the vehicle body angular velocity sensor 34. The wobble suppression assist torque Tw is a torque for suppressing the wobble of the motorcycle 1. For example, the wobble suppression assist torque Tw acts in the direction of turning the bar handle 4 and the front wheel 2 to the left when the motorcycle 1 is tilted to the left. The wobble suppression assist torque Tw acts in the direction of turning the bar handle 4 and the front wheel 2 to the right when the motorcycle 1 is tilted to the right.
The applied torque calculation unit 400 calculates the applied torque Tms, which will be described later, based on the detection information of the external detection means 38 and the like.

The control device 23 includes an adder 224 and a motor drive unit 226.
As shown in the following equation (2), the adder 224 adds the power assist torque Tp and the wobble suppression assist torque Tw to generate the assist torque Tm. The adder 224 outputs the generated assist torque Tm to the motor drive unit 226.
Tm = Tp + Tw ... (2)

The motor drive unit 226 converts the assist torque Tm into a torque current and supplies it to the electric motor of the steering actuator 43. The electric motor is driven while the torque current is being supplied, and generates a driving force according to the torque current. The driving force of the electric motor is transmitted to the handle post 4a via the connecting rod 43c or the like, and assists the rotation of the bar handle 4 and the front wheels 2. That is, a driving force (auxiliary force) corresponding to the assist torque Tm is applied to the bar handle 4 and the front wheel 2.

With reference to FIG. 4, the wobble suppression assist torque calculation block 300 includes a composite angular speed generation unit 302, a multiplier 304, a first vehicle speed correction coefficient generation unit 306, a second vehicle speed correction coefficient generation unit 308, and a multiplier 310. , An adder 312, a divider 314, and a multiplier 316.
The combined angular velocity generation unit 302 synthesizes the yaw angular velocity Y and the roll angular velocity R detected by the vehicle body angular velocity sensor 34 to generate a combined angular velocity (vehicle body behavior rate) S indicating the behavior of the motorcycle 1.
The multiplier 304 multiplies the combined angular velocity S and the combined angular velocity S to generate the square of the combined angular velocity S.

The first vehicle speed correction coefficient generation unit 306 generates a first vehicle speed correction coefficient F that suppresses wobbling based on the vehicle speed V.
The second vehicle speed correction coefficient generation unit 308 generates a second vehicle speed correction coefficient G that suppresses wobbling based on the vehicle speed V.
The multiplier 310 multiplies the second vehicle speed correction coefficient G by the square of the combined angular velocity S.
The adder 312 adds the value (G × S ² ) output by the multiplier 310 and the constant α.
The divider 314 divides the first vehicle speed correction coefficient F by the value (G × S ² + α) output by the adder 312.

The multiplier 316 multiplies the value (F / (G × S ² + α)) output by the divider 314 by the combined angular velocity S. That is, the multiplier 316 outputs the wobble suppression assist torque Tw shown in the following equation (3).
Tw = F × S / (G × S ² + α)… (3)

When the motorcycle 1 is swaying (when the driver does not intend to tilt), the combined angular velocity S becomes a relatively small value. When the motorcycle 1 is tilted by the driver's weight transfer operation, the combined angular velocity S becomes a relatively large value. In these cases, the following effects can be obtained by calculating the wobble suppression assist torque Tw by the equation (3). That is, when the combined angular velocity S is large, the wobble suppression assist torque Tw can be reduced. Therefore, the wobble suppression assist torque Tw can be set so as not to interfere with the operation due to the driver's weight shift, and the drivability can be improved.

As described above, the composite angular velocity generation unit 302 synthesizes (adds) these on the low speed side by increasing the weighting of the yaw angular velocity Y and decreasing the weighting of the roll angular velocity R. On the high-speed side, the composite angular velocity generation unit 302 synthesizes (adds) these by reducing the weighting of the yaw angular velocity Y and increasing the weighting of the roll angular velocity R. Considering the steering characteristics of the motorcycle 1, it is preferable to detect a large yaw angular velocity Y at low speed and a large roll angular velocity R at high speed from the viewpoint of detecting the behavior of the motorcycle 1 with high accuracy.

Then, when the behavior of the motorcycle 1 is large, the control device 23 determines that it is due to the weight operation of the driver and reduces the assist torque Tw. When the behavior of the motorcycle 1 is small, the control device 23 determines that the vehicle body is wobbling rather than the driver's weight operation, and increases the assist torque Tw.
In this way, regardless of whether the motorcycle 1 is at low speed or at high speed, it is possible to assist the driver to suppress wobbling without discomfort.

By the way, when the above-mentioned driving assist control is performed, the motorcycle 1 has behavior that the rider does not intend. Therefore, it is desirable to enhance the effect of stabilizing the vehicle body as compared with the normal assist steering control when the driving assist control is not performed. That is, it is desirable to increase the assist torque Tm when the driving assist control is activated. In the present embodiment, when the specified functions (including warnings) of the driving support system (ARAS: Advanced rider assistance system) of the motorcycle 1 are activated, the control shifts to the control focusing on the stability of the vehicle body behavior.

In the present embodiment, the functions for applying the control emphasizing the stability of vehicle body behavior are, for example, the following three functions among the various functions of the driving support system of the motorcycle 1.
The first is Collision Mitigation Brake System (CMBS), the second is Lane Departure Warning (LDW), and the third is Blind Spot Information (BSI). is there.

First, an example of CMBS will be described.
With reference to FIGS. 6 and 7, in the CMBS of the embodiment, a three-step warning threshold TTC is set. For the warning threshold TTC of CMBS, a relative time distance (distance traveling within a specified time at the current speed) with respect to an obstacle such as another vehicle T in front of the own vehicle M is used as a control parameter. The first warning threshold value t1 is a threshold value for performing a caution display (first warning) using an indicator lamp, a liquid crystal panel, or the like. The first warning is activated when the relative time distance from the obstacle becomes less than or equal to the threshold value t1 (when the threshold value t1 is exceeded on the decreasing side or when the threshold value is less than t1). In the first warning, the brake operation (braking) by the automatic brake control is not performed.

The second warning threshold (first threshold) t2 is a stronger second warning than the first warning (for example, a warning to the rider's tactile sensation such as vibrating the body contact portion of the vehicle body, and a vehicle body such as performing weak braking. This is the threshold value when performing a warning) that causes behavior. The second warning is activated when the relative time distance from the obstacle becomes the threshold value t2 or less, which is shorter than the threshold value t1 (when the threshold value t2 is exceeded on the decreasing side or when the threshold value is below the threshold value t2). In the second warning, a relatively weak braking operation (braking) is performed by automatic braking control.

The third warning threshold (second threshold) t3 is a threshold for issuing a third warning (for example, a warning due to stronger vibration or the like and a warning due to stronger braking or the like) that is stronger than the second warning. The third warning is activated when the relative time distance from the obstacle becomes the threshold value t3 or less, which is shorter than the threshold value t2 (when the threshold value t3 is exceeded on the decreasing side or when the threshold value is below the threshold value t3). In the third warning, a relatively strong braking operation (braking) is performed by automatic braking control.

Each of the first to third warnings is set to become stronger as the relative time distance from the obstacle becomes shorter.
In the embodiment, when the relative time distance from the obstacle becomes the threshold value t3 or less (when the third warning flag is ON), the motorcycle shifts to the high stabilization control that prioritizes the improvement of the attitude control of the motorcycle 1. In the high stabilization control, the assist steer control gain is corrected to a higher stable gain. As a result, the decrease of the assist torque Tm is suppressed and maintained at a high value, and the attitude control of the motorcycle 1 is improved. When the relative time distance is between the threshold value t2 and the threshold value t3, the high stabilization control is not performed, but the high stabilization control may be performed with a weaker output than when the relative time distance is equal to or less than the threshold value t3.

Next, an example of LDW will be described.
With reference to FIGS. 6 and 8, in the LDW of the embodiment, a three-step warning threshold TTLD is set. For the LDW warning threshold TTLD, the distance from the lane marking line (center line, boundary line, outer line, etc.) L1 of the vehicle lane (traveling lane) to the own vehicle is used as a control parameter. The first warning threshold value t1 is a threshold value for performing a caution display (first warning) using an indicator lamp, a liquid crystal panel, or the like. The first warning is activated when the distance from the lane marking L1 is equal to or less than the threshold value t1 (when the threshold value t1 is exceeded on the decreasing side or when the distance is below the threshold value t1). In the first warning, the brake operation (braking) by the automatic brake control is not performed.

The second warning threshold (first threshold) t2 is a stronger second warning than the first warning (for example, a warning to the rider's tactile sensation such as vibrating the body contact portion of the vehicle body, and a vehicle body such as performing weak braking. This is the threshold value when performing a warning) that causes behavior. The second warning is activated when the distance from the lane marking L1 becomes less than or equal to the threshold value t2, which is shorter than the threshold value t1 (when the threshold value t2 is exceeded on the decreasing side or when the distance is below the threshold value t2). The threshold value t2 includes the case where the distance is 0. That is, there may be a setting in which the second warning is activated immediately before the departure from the lane. In the second warning, a relatively weak braking operation (braking) is performed by automatic braking control.

The third warning threshold (second threshold) t3 is a threshold for issuing a third warning (for example, a warning due to stronger vibration or the like and a warning due to stronger braking or the like) that is stronger than the second warning. The third warning is activated when the distance from the lane marking L1 becomes the threshold value t3 or less, which is shorter than the threshold value t2 (when the threshold value t3 is exceeded on the decreasing side or when the threshold value is below the threshold value t3). The threshold value t3 includes the case of a negative distance. That is, there may be a setting in which the third warning is activated when the lane departure amount becomes the threshold value t3 or more. In the third warning, a relatively strong braking operation (braking) is performed by automatic braking control.

Each of the first to third warnings is set so as to become stronger as the distance from the lane marking L1 becomes shorter or becomes larger on the minus side.
In the embodiment, when the distance from the lane marking L1 is equal to or less than the threshold value t3 (when the third warning flag is ON), the motorcycle shifts to high stabilization control prioritizing the improvement of the attitude control of the motorcycle 1. In the high stabilization control, the assist steer control gain is corrected to a higher stable gain. As a result, the decrease of the assist torque Tm is suppressed and maintained at a high value, and the attitude control of the motorcycle 1 is improved. When the distance from the lane marking L1 is between the threshold value t2 and the threshold value t3, the high stabilization control is not performed, but the high stabilization control is performed with a weaker output than when the threshold value is t3 or less. May be good.

Next, an example of BSI will be described.
With reference to FIGS. 6 and 9, in the BMI of the embodiment, a two-step warning threshold is set. A predetermined number of detection flags is used as a control parameter for the BMI warning threshold.
The detection flags used for the BMI warning threshold are, for example, the following two flags, the first flag and the second flag.
The first flag is a flag indicating that the presence of another vehicle T has been detected in the detection area AR on either the left or right side behind the own vehicle M. The second flag is a flag indicating that the course change prediction operation (the action in which the course change is predicted) of the own vehicle M to the side where the other vehicle T is detected is detected while the first flag is set. is there.

The first flag indicates that the other vehicle T is actually detected by a camera, radar, or the like in the embodiment, but the present invention is not limited to this. For example, the first flag may predict and detect the presence of the other vehicle T by the fact that the other vehicle T located behind the own vehicle M in the same lane emits either the left or right winker.
The second flag is not limited to the operation of the winker of the own vehicle M on the side where the presence of the other vehicle T is recognized in the embodiment. For example, the second flag may indicate that at least one of the seating position, the sitting posture, the operation of the reverse steering wheel, and the like of the rider of the own vehicle M is detected as the course change prediction operation.

When the first flag is set (when the presence of another vehicle T is detected in the detection area), the first warning is activated. The first warning is a caution display using, for example, an indicator lamp or a liquid crystal panel. In the first warning, the brake operation (braking) by the automatic brake control is not performed, but the relatively weak brake operation (braking) by the automatic brake control may be performed.
When the second flag is set (when the course change prediction motion is detected, when two flags are set), the second warning (for example, vibrating the body contact part of the vehicle body) is stronger than the first warning. Assist steer to warn the tactile sensation of the vehicle and to generate vehicle body behavior such as braking stronger than specified) and to suppress roll (and lane change) to the side where the presence of another vehicle T is recognized. Adjust the control gain. In the third warning, a relatively strong braking operation (braking) is performed by automatic braking control.

Specifically, the assist steering control gain is adjusted so that the reverse steering wheel operation to the side opposite to the side where the presence of the other vehicle T is recognized is heavier than the steering wheel operation to the side where the presence of the other vehicle T is recognized. .. For example, in the high stabilization control, the assist steering control gain is corrected to a higher stable gain only for the reverse steering operation to the side opposite to the side where the presence of the other vehicle T is recognized, and the presence of the other vehicle T is present. For the steering wheel operation to the permitted side, the control to reduce the assist torque Tm is maintained.

The following formula 1 is a formula for calculating the applied torque Tms for variable maneuverability when the flag of ARAS operation or operation warning is set. In the formula, a indicates the front wheel inertia correction coefficient, and the front wheel presession effect (gyro moment effect) is amplified by (a + FlagARAS × GainARAS). In the formula, Iwhere indicates the front wheel rotational inertia, ωwhel indicates the front wheel rotational angular velocity, and Ω indicates the vehicle body roll rate.

The strength of the steering assist of the embodiment will be described with reference to the graph of FIG. In the graph of FIG. 10, the vertical axis represents the assist strength with respect to the roll rate, and the horizontal axis represents the vehicle speed.
The maneuverability of a plain motorcycle 1 without control is along the horizontal axis of the graph. On the other hand, in the control that weakens the turning characteristic of the rudder (region R1 in the figure), the assist strength is increased to the minus side between the medium speed range and the high speed range. This reduces the entire assist torque Tm and contributes to light maneuverability.
In the control for strengthening the turning characteristic of the rudder (region R2 in the figure), the assist strength is increased to the plus side between the medium speed range and the high speed range. This increases the overall assist torque Tm and contributes to heavy maneuverability. At this time, maneuverability is obtained as if the gyro moment of the front wheel 2 was increased.
In addition to these controls, in the control for further increasing the assist strength to the plus side (region R3 in the figure), the applied torque Tms of Equation 3 is further added to the region R2 between the medium speed range and the high speed range. As a result, the entire assist torque Tm is further increased, which contributes to an increase in straightness (high stabilization control).

In particular, when an obstacle such as another vehicle T is detected in front of the own vehicle M and collision mitigation braking (automatic brake control) is applied, the relative time distance to the obstacle (distance traveled within the specified time at the current speed) is controlled. As a parameter, the brake strength of automatic brake control is controlled. Then, during strong braking control when the control parameter exceeds a predetermined threshold value (third threshold value t3), the entire assist torque Tm is increased to achieve high stabilization as compared with control when the control parameter does not exceed the threshold value. Contribute to control. In other words, the behavior stabilization control by assist steer control is strengthened.

In this way, at the time of ARAS operation, it is possible to shift to the control that prioritizes the improvement of the attitude control of the motorcycle 1 by using the threshold value of ARAS operation as a trigger. In particular, when the CMBS is operating, appropriate assist steer control can be performed according to the braking strength of the automatic brake control. In other words, the brake strength of the automatic brake control is set in multiple stages, and until the situation where the strong brake control is performed, the second brake control that gives priority to the driver's steering wheel operation, such as not performing the brake control or performing the weak brake control. I do. Then, in the situation where the strong brake control is performed, the effect of the BSI can be enhanced by performing the control that gives priority to the improvement of the attitude control of the motorcycle 1.

As described above, the steering assist device 50 in the above embodiment is a saddle-riding vehicle (for example, a saddle-riding vehicle) (for example, a body frame 5) that swings in the roll direction to generate a steering angle on the steering wheels (for example, the front wheels 2). It is a steering assist device 50 of a motorcycle 1). The steering assist device 50 includes a steering actuator 43 that applies an assist torque Tm in the steering direction to the front wheel suspension device 3 that supports the front wheels 2, a control device 23 that drives and controls the steering actuator 43, and an external device that detects the situation around the vehicle. The detection means 38 and the like are provided.
When performing driving support control, the control device 23 shifts to control that emphasizes stability of vehicle body behavior. The control device 23 changes the control gain based on the warning of ARAS (CMBS, LDW, BSI, etc.), the operation determination threshold information, or the information indicating that the operation is in progress. As a result, it is possible to carry out an more appropriate degree of assist steer control according to each situation during ARAS operation, and it is possible to improve the attitude control of the vehicle.

Then, in the steering assist device 50, when the external detection means 38 detects an obstacle (another vehicle T) in front of the own vehicle M, the control device 23 operates the brake regardless of the driver's operation. In addition to performing automatic brake control, the brake strength of automatic brake control is controlled according to a predetermined control parameter (relative time distance). Then, in the case of strong brake control when the control parameter exceeds the predetermined threshold value t3, the behavior stabilization control by the assist steer control is strengthened as compared with the control in the case where the control parameter does not exceed the threshold value t3.
According to this configuration, while the driving support system detects an obstacle in front of the vehicle M, automatic braking control is performed when the approach of the obstacle is detected based on the obstacle detection information. When the driver unintentionally operates the steering wheel due to the automatic brake control, the behavior of the vehicle becomes large and the stability is affected. Therefore, when the control parameter that determines the brake strength of the automatic brake control exceeds the threshold value t3, the strong brake control is performed, as compared with the control when the control parameter does not exceed the threshold value t3 (weak brake control or no brake control). , The behavior stabilization control is strengthened by strengthening the assist torque Tm. In this way, it is possible to carry out appropriate assist steering control according to the braking strength of the automatic brake control, and it is possible to enhance the effect of the driving support system.

In the steering assist device 50, the control device 23 sets a plurality of stages of brake strength and a plurality of threshold values t2 and t3 corresponding to each brake strength in automatic brake control, and when the control parameter exceeds the first threshold value t2. , The relatively weak weak brake control is performed, and when the control parameter exceeds the second threshold value t3, the relatively strong strong brake control is performed and the behavior stabilization control by the assist steer control is strengthened.
According to this configuration, in a configuration in which a plurality of stages of brake strength and threshold value are set for automatic brake control, behavior is stabilized by increasing the assist torque Tm during strong brake control at a stage where the control parameter exceeds the second threshold value t3. Strengthen the control of conversion. As a result, it is possible to carry out assist steering control with less discomfort to the driver.

In the steering assist device 50, the control device 23 does not strengthen the behavior stabilization control during the weak brake control, or strengthens the behavior stabilization control in a range of output weaker than that during the strong brake control.
According to this configuration, in a configuration in which a plurality of stages of brake strength and threshold value are set for automatic brake control, the control parameter exceeds the first threshold value t2 during weak brake control at a stage where the control parameter exceeds the first threshold value t2. The behavior stabilization control is not strengthened as compared with the control at no stage (when there is no brake control, etc.), or the behavior stabilization control is strengthened with a weaker output than when the strong brake control is performed. As a result, it is possible to gradually strengthen the behavior stabilization control up to the strong brake control, and it is possible to carry out the assist steer control with less discomfort to the driver.

The present invention is not limited to the above embodiment. In the above-described embodiment, for example, a vehicle including the link type front wheel suspension device 3 has been illustrated, but the present invention is not limited to this. For example, the vehicle may be provided with a well-known telescopic front fork in the front wheel suspension system.
Motorcycles are not limited to vehicles in which the driver rides across the vehicle body, but also include scooter-type vehicles having a step floor and motorized bicycles. Not limited to motorcycles, it can also be applied to saddle-riding vehicles in which the front wheels and the front wheel suspension device are tilted and turned together with the vehicle body frame 5.

The saddle-riding vehicle includes all vehicles in which the driver rides across the vehicle body and rolls the vehicle body to balance the vehicle. Not only motorcycles, but also three-wheeled vehicles (including front two-wheeled and rear one-wheeled vehicles in addition to front one-wheeled and rear two-wheeled vehicles) or four-wheeled vehicles are also included. Includes scooter-type vehicles with step floors and motorbikes. Vehicles that include an electric motor in the prime mover are also included.
The configuration in the above embodiment is an example of the present invention, and various modifications can be made without departing from the gist of the present invention, such as replacing the constituent elements of the embodiment with well-known constituent elements.

1 Motorcycle (saddle-riding vehicle)
2 Front wheels (steering wheels)
3 Front wheel suspension system (suspension system)
23 Control device (control means)
38 External detection means 43 Steering actuator 50 Steering assist device Tm Assist torque t2 Second threshold value (first threshold value)
t3 Third threshold (second threshold)

Claims (3)

1. In the steering assist device (50) of the saddle-riding vehicle (1) that swings the vehicle body (5) in the roll direction to generate a steering angle on the steering wheels (2).
   A steering actuator (43) that applies assist torque (Tm) to the suspension device (3) that supports the steering wheel (2), and
   A control means (23) that drives and controls the steering actuator (43), and
   It is equipped with an external detection means (38) that detects the situation around the vehicle.
   The control means (23) performs automatic brake control that activates the brake regardless of the driver's operation when the external detection means (38) detects an obstacle in front of the own vehicle, and is predetermined. The brake strength of the automatic brake control is controlled according to the control parameter, and the control parameter does not exceed the threshold value (t3) at the time of strong brake control when the control parameter exceeds a predetermined threshold value (t3). A steering assist device for saddle-riding vehicles that strengthens behavior stabilization control by assist steering control compared to when controlling the case.
2. The control means (23) sets a plurality of stages of brake strength and a plurality of threshold values (t2, t3) corresponding to each brake strength in the automatic brake control, and the control parameter sets the first threshold value (t2). When it exceeds, relatively weak first brake control is performed, and when the control parameter exceeds the second threshold value (t3), relatively strong second brake control is performed, and behavior stabilization control by the assist steer control is performed. The steering assist device for a saddle-riding vehicle according to claim 1, which is strengthened.
3. The control means (23) according to claim 2, wherein the behavior stabilization control is not strengthened at the time of the first brake control, or the behavior stabilization control is strengthened in a range of an output weaker than that at the time of the strong brake control. Steering assist device for saddle-riding vehicles.

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