Patent Description:
As a conventional technique relating to a straddle-type vehicle, a technique of assisting with a driver's operation is available.

For example, a driver assistance system is disclosed in PTL <NUM>. Based on information detected by a sensor that detects an obstacle present in a travel direction or substantially in the travel direction, the driver assistance system warns a motorcycle driver that the motorcycle inappropriately approaches the obstacle. PTL <NUM> provides a leaning vehicle including an active driving assist device which is configured to actively assist a driver.

By the way, as the technique of assisting with the driver's operation, it is considered to adopt adaptive cruise control, which makes a vehicle travel according to a distance from the vehicle to a preceding vehicle, motion of the vehicle, and the driver's instruction, for the straddle-type vehicle such as the motorcycle. In the adaptive cruise control, the vehicle is accelerated or decelerated without relying on an acceleration or deceleration operation by the driver when a braking force or drive power is automatically exerted thereon. Meanwhile, differing from a four-wheeled vehicle, for example, the straddle-type vehicle corners when the driver leans the straddle-type vehicle in a rolling direction. Here, a posture of the straddle-type vehicle in the rolling direction during cornering is influenced by the braking force or the drive power exerted on the vehicle. Thus, in the case where the braking force or the drive power that is automatically exerted on the straddle-type vehicle during the adaptive cruise control is not appropriately controlled, appropriate cornering possibly becomes difficult.

The present invention has been made in view of the above-described problem, and therefore obtains a controller and a control method capable of achieving appropriate cornering during adaptive cruise control of a straddle-type vehicle.

A controller according to the present invention, as defined by independent claim <NUM>, is a controller that controls travel of a straddle-type vehicle, and includes a control section capable of executing adaptive cruise control in which the straddle-type vehicle is made to travel according to a distance from the straddle-type vehicle to a preceding vehicle, motion of the straddle-type vehicle, and a driver's instruction. During the adaptive cruise control, the control section controls braking force distribution, which is distribution of braking forces generated on a front wheel and a rear wheel of the straddle-type vehicle (<NUM>), on the basis of a lateral acceleration of the straddle-type vehicle according to a lean angle of the straddle-type vehicle; the control section (<NUM>), in the case where the lean angle of the straddle-type vehicle (<NUM>) is smaller than a first reference angle, determines that the straddle-type vehicle (<NUM>) is passing an entry of a curved road, and executes a first braking mode in which the braking force distribution is controlled such that the lateral acceleration becomes such acceleration that increases the lean angle of the straddle-type vehicle (<NUM>); and the control section (<NUM>), in the case where the lean angle of the straddle-type vehicle (<NUM>) is equal to or larger than the first reference angle, determines that the straddle-type vehicle (<NUM>) is traveling on the curved road, and executes a second braking mode in which the braking force distribution is controlled such that the lateral acceleration is maintained.

A control method according to the present invention, as defined by independent claim <NUM>, is a control method for controlling travel of a straddle-type vehicle. In the control method, during adaptive cruise control in which the straddle-type vehicle is made to travel according to a distance from the straddle-type vehicle to a preceding vehicle, motion of the straddle-type vehicle, and a driver's instruction, braking force distribution, which is distribution of braking forces generated on a front wheel and a rear wheel of the straddle-type vehicle (<NUM>), is controlled by a controller on the basis of lateral acceleration of the straddle-type vehicle according to a lean angle of the straddle-type vehicle, wherein: the controller (<NUM>), in the case where the lean angle of the straddle-type vehicle (<NUM>) is smaller than a first reference angle, determines that the straddle-type vehicle.

(<NUM>) is passing an entry of a curved road, and executes a first braking mode in which the braking force distribution is controlled such that the lateral acceleration becomes such acceleration that increases the lean angle of the straddle-type vehicle (<NUM>); and the controller (<NUM>), in the case where the lean angle of the straddle-type vehicle (<NUM>) is equal to or larger than the first reference angle, determines that the straddle-type vehicle (<NUM>) is traveling on the curved road, and executes a second braking mode in which the braking force distribution is controlled such that the lateral acceleration is maintained.

In the controller and the control method according to the present invention, during the adaptive cruise control in which the straddle-type vehicle is made to travel according to the distance from the straddle-type vehicle to the preceding vehicle, the motion of the straddle-type vehicle, and the driver's instruction, at least one of the braking force distribution, which is the distribution of the braking forces generated on the wheels of the straddle-type vehicle to the front and rear wheels, and the drive power distribution, which is the distribution of the drive power transmitted to the wheels of the straddle-type vehicle to the front and rear wheels, is controlled on the basis of the lateral acceleration of the straddle-type vehicle. In this way, during cornering, it is possible to suppress the straddle-type vehicle from exhibiting behavior in a rolling direction that is unintended by the driver and is caused when the braking force or the drive power is automatically exerted on the straddle-type vehicle. Therefore, the straddle-type vehicle can appropriately corner during the adaptive cruise control of the straddle-type vehicle.

A description will hereinafter be made on a controller according to the present invention with reference to the drawings. Hereinafter, a description will be made on the controller used for a two-wheeled motorcycle. However, the controller according to the present invention may be used for a straddle-type vehicle other than the two-wheeled motorcycle (for example, a three-wheeled motorcycle, an all-terrain vehicle, a bicycle, or the like). The straddle-type vehicle means a vehicle that a driver straddles. In addition, a description will hereinafter be made on a case where a motor is mounted as a drive source capable of outputting drive power for driving motorcycle wheels. However, as the drive source of the motorcycle, a drive source other than the motor (for example, an engine) may be mounted, or multiple drive sources may be mounted.

A configuration, operation, and the like, which will be described below, merely constitute one example. The controller and the control method according to the present invention are not limited to a case with such a configuration, such operation, and the like.

The same or similar description will appropriately be simplified or will not be made below. In the drawings, the same or similar members or portions will not be denoted by a reference sign or will be denoted by the same reference sign. In addition, a detailed structure will appropriately be illustrated in a simplified manner or will not be illustrated.

A description will be made on a configuration of a motorcycle <NUM> on which a controller <NUM> according to an embodiment of the present invention is mounted with reference to <FIG>.

<FIG> is a schematic view of the configuration of the motorcycle <NUM> on which the controller <NUM> is mounted. <FIG> is a schematic diagram of a configuration of a brake system <NUM>. <FIG> is a view for illustrating a lean angle. <FIG> is a block diagram of an exemplary functional configuration of the controller <NUM>.

As illustrated in <FIG>, the motorcycle <NUM> includes: a trunk <NUM>; a handlebar <NUM> that is held by the trunk <NUM> in a freely turnable manner; a front wheel <NUM> that is held by the trunk <NUM> in the freely turnable manner with the handlebar <NUM>; a rear wheel <NUM> that is held by the trunk <NUM> in a freely rotatable manner; motors <NUM>, <NUM>; and the brake system <NUM>. In this embodiment, the controller (ECU) <NUM> is provided in a hydraulic pressure control unit <NUM> of the brake system <NUM>, which will be described later. As illustrated in <FIG> and <FIG>, the motorcycle <NUM> further includes: an inter-vehicular distance sensor <NUM>, an input device <NUM>, a front-wheel rotational frequency sensor <NUM>, a rear-wheel rotational frequency sensor <NUM>, an inertial measurement unit (IMU) <NUM>, a lateral acceleration sensor <NUM>, a master-cylinder pressure sensor <NUM>, and a wheel-cylinder pressure sensor <NUM>.

Each of the motors <NUM>, <NUM> corresponds to an example of the drive source for the motorcycle <NUM>, and can output the drive power for driving the wheel. More specifically, the motors <NUM>, <NUM> are respectively provided on the front wheel <NUM> and the rear wheel <NUM>. An output shaft of the motor <NUM> is connected to the front wheel <NUM>, and the drive power output from the motor <NUM> is transmitted to the front wheel <NUM>. Meanwhile, an output shaft of the motor <NUM> is connected to the rear wheel <NUM>, and the drive power output from the motor <NUM> is transmitted to the rear wheel <NUM>. In detail, each of the motors <NUM>, <NUM> is connected to a battery (not illustrated) via an inverter, and generation of the drive power by each of the motors <NUM>, <NUM> is controlled by controlling operation of the inverter. Such operation of each of the motors <NUM>, <NUM> is controlled by the controller <NUM>. As a result, the drive power transmitted from the motor <NUM> to the front wheel <NUM> and the drive power transmitted from the motor <NUM> to the rear wheel <NUM> are controlled.

As illustrated in <FIG> and <FIG>, the brake system <NUM> includes: a first brake operation section <NUM>; a front-wheel brake mechanism <NUM> that brakes the front wheel <NUM> in an interlocking manner with at least the first brake operation section <NUM>; a second brake operation section <NUM>; and a rear-wheel brake mechanism <NUM> that brakes the rear wheel <NUM> in an interlocking manner with at least the second brake operation section <NUM>. The brake system <NUM> also includes the hydraulic pressure control unit <NUM>, and a part of the front-wheel brake mechanism <NUM> and a part of the rear-wheel brake mechanism <NUM> are included in the hydraulic pressure control unit <NUM>. The hydraulic pressure control unit <NUM> is a unit that has a function of controlling a braking force to be generated on the front wheel <NUM> by the front-wheel brake mechanism <NUM> and a braking force to be generated on the rear wheel <NUM> by the rear-wheel brake mechanism <NUM>.

The first brake operation section <NUM> is provided on the handlebar <NUM> and is operated by the driver's hand. The first brake operation section <NUM> is a brake lever, for example. The second brake operation section <NUM> is provided in a lower portion of the trunk <NUM> and is operated by the driver's foot. The second brake operation section <NUM> is a brake pedal, for example.

Each of the front-wheel brake mechanism <NUM> and the rear-wheel brake mechanism <NUM> includes: a master cylinder <NUM> in which a piston (not illustrated) is installed; a reservoir <NUM> that is attached to the master cylinder <NUM>; a brake caliper <NUM> that is held by the trunk <NUM> and has a brake pad (not illustrated) ; a wheel cylinder <NUM> that is provided in the brake caliper <NUM>; a primary channel <NUM> through which a brake fluid in the master cylinder <NUM> flows into the wheel cylinder <NUM>; a secondary channel <NUM> through which the brake fluid in the wheel cylinder <NUM> is released; and a supply channel <NUM> through which the brake fluid in the master cylinder <NUM> is supplied to the secondary channel <NUM>.

An inlet valve (EV) <NUM> is provided in the primary channel <NUM>. The secondary channel <NUM> bypasses a portion of the primary channel <NUM> between the wheel cylinder <NUM> side and the master cylinder <NUM> side from the inlet valve <NUM>. The secondary channel <NUM> is sequentially provided with an outlet valve (AV) <NUM>, an accumulator <NUM>, and a pump <NUM> from an upstream side. Between an end of the primary channel <NUM> on the master cylinder <NUM> side and a portion of the primary channel <NUM> to which a downstream end of the secondary channel <NUM> is connected, a first valve (USV) <NUM> is provided. The supply channel <NUM> communicates between the master cylinder <NUM> and a portion of the secondary channel <NUM> on a suction side of the pump <NUM>. A second valve (HSV) <NUM> is provided in the supply channel <NUM>.

The inlet valve <NUM> is an electromagnetic valve that is opened in an unenergized state and closed in an energized state, for example. The outlet valve <NUM> is an electromagnetic valve that is closed in an unenergized state and opened in an energized state, for example. The first valve <NUM> is an electromagnetic valve that is opened in an unenergized state and is closed in an energized state, for example. The second valve <NUM> is an electromagnetic valve that is closed in an unenergized state and is opened in an energized state, for example.

The hydraulic pressure control unit <NUM> includes: components such as the inlet valves <NUM>, the outlet valves <NUM>, the accumulators <NUM>, the pumps <NUM>, the first valves <NUM>, and the second valves <NUM> used to control a brake hydraulic pressure; a base body <NUM> in which those components are provided and channels constituting the primary channels <NUM>, the secondary channels <NUM>, and the supply channels <NUM> are formed; and the controller <NUM>.

The base body <NUM> may be formed of one member or may be formed of multiple members. In the case where the base body <NUM> is formed of the multiple members, the components may separately be provided in the different members.

The controller <NUM> controls operation of each of the components in the hydraulic pressure control unit <NUM>. As a result, the braking force to be generated on the front wheel <NUM> by the front-wheel brake mechanism <NUM> and the braking force to be generated on the rear wheel <NUM> by the rear-wheel brake mechanism <NUM> are controlled.

For example, in a normal time (that is, when none of adaptive cruise control and anti-lock brake control, which will be described later, is executed), the controller <NUM> opens the inlet valves <NUM>, closes the outlet valves <NUM>, opens the first valves <NUM>, and closes the second valves <NUM>. When the first brake operation section <NUM> is operated in such a state, in the front-wheel brake mechanism <NUM>, the piston (not illustrated) in the master cylinder <NUM> is pressed to increase a hydraulic pressure of the brake fluid in the wheel cylinder <NUM>, the brake pad (not illustrated) of the brake caliper <NUM> is then pressed against a rotor 3a of the front wheel <NUM>, and the braking force is thereby generated on the front wheel <NUM>. Meanwhile, when the second brake operation section <NUM> is operated, in the rear-wheel brake mechanism <NUM>, the piston (not illustrated) in the master cylinder <NUM> is pressed to increase the hydraulic pressure of the brake fluid in the wheel cylinder <NUM>, the brake pad (not illustrated) of the brake caliper <NUM> is then pressed against a rotor 4a of the rear wheel <NUM>, and the braking force is thereby generated on the rear wheel <NUM>.

The inter-vehicular distance sensor <NUM> detects a distance from the motorcycle <NUM> to a preceding vehicle. The inter-vehicular distance sensor <NUM> may detect another physical quantity that can substantially be converted to the distance from the motorcycle <NUM> to the preceding vehicle. Here, the preceding vehicle means a vehicle ahead of the motorcycle <NUM> and may include, in addition to the nearest vehicle from the motorcycle <NUM> on the same lane as a travel lane of the motorcycle <NUM>, a vehicle ahead of several vehicles in front of the motorcycle <NUM>, a vehicle traveling on an adjacent lane to the travel lane of the motorcycle <NUM>, and the like. For example, in the case where the multiple vehicles exist ahead of the motorcycle <NUM>, based on a track, which is estimated as a travel track of the motorcycle <NUM>, and behavior of each of the multiple vehicles, the inter-vehicular distance sensor <NUM> selects the preceding vehicle as a detection target of the distance from the motorcycle <NUM>. In this case, the adaptive cruise control, which will be described later, is executed by using a detection result of the distance from the motorcycle <NUM> to the thus-selected preceding vehicle.

As the inter-vehicular distance sensor <NUM>, for example, a camera that captures an image in front of the motorcycle <NUM> and a radar that can detect a distance from the motorcycle <NUM> to a target in front are used. In such a case, for example, the preceding vehicle is recognized by using the image captured by the camera. Then, by using the recognition result of the preceding vehicle and a detection result by the radar, the distance from the motorcycle <NUM> to the preceding vehicle can be detected. The inter-vehicular distance sensor <NUM> is provided in a front portion of the trunk <NUM>, for example. Note that the configuration of the inter-vehicular distance sensor <NUM> is not limited to the above example, and a stereo camera may be used as the inter-vehicular distance sensor <NUM>, for example.

The input device <NUM> accepts a travel mode selection operation by the driver, and outputs information indicative of the travel mode selected by the driver. As will be described later, in the motorcycle <NUM>, the controller <NUM> can execute the adaptive cruise control. The adaptive cruise control is control in which the motorcycle <NUM> is made to travel according to the distance from the motorcycle <NUM> to the preceding vehicle, motion of the motorcycle <NUM>, and the driver's instruction. By using the input device <NUM>, the driver can select, as one of the travel modes, a travel mode in which the adaptive cruise control is executed. For example, as the input device <NUM>, a lever, a button, a touch screen, or the like is used. The input device <NUM> is provided on the handlebar <NUM>, for example.

The front-wheel rotational frequency sensor <NUM> detects a rotational frequency of the front wheel <NUM> and outputs a detection result. The front-wheel rotational frequency sensor <NUM> may detect another physical quantity that can substantially be converted to the rotational frequency of the front wheel <NUM>. The front-wheel rotational frequency sensor <NUM> is provided on the front wheel <NUM>.

The rear-wheel rotational frequency sensor <NUM> detects a rotational frequency of the rear wheel <NUM> and outputs a detection result. The rear-wheel rotational frequency sensor <NUM> may detect another physical quantity that can substantially be converted to the rotational frequency of the rear wheel <NUM>. The rear-wheel rotational frequency sensor <NUM> is provided on the rear wheel <NUM>.

The inertial measurement unit <NUM> includes a three-axis gyroscope sensor and a three-directional acceleration sensor, and detects a posture of the motorcycle <NUM>. For example, the inertial measurement unit <NUM> detects the lean angle of the motorcycle <NUM>, and outputs a detection result. The inertial measurement unit <NUM> may detect another physical quantity that can substantially be converted to the lean angle of the motorcycle <NUM>. For example, the lean angle corresponds to a tilt angle θ of the motorcycle <NUM> in a rolling direction with respect to an upper vertical direction illustrated in <FIG>. The inertial measurement unit <NUM> is provided in the trunk <NUM>, for example. In the motorcycle <NUM>, instead of the inertial measurement unit <NUM>, a sensor that only has a function of detecting the lean angle may be used.

The lateral acceleration sensor <NUM> detects lateral acceleration of the motorcycle <NUM>, and outputs a detection result. The lateral acceleration sensor <NUM> may detect another physical quantity that can substantially be converted to the lateral acceleration of the motorcycle <NUM>. The lateral acceleration is a component of acceleration, which is generated on the motorcycle <NUM>, in a lateral direction (that is, a vehicle width direction) of the motorcycle <NUM>. The lateral acceleration sensor <NUM> is provided in the trunk <NUM>, for example.

The master-cylinder pressure sensor <NUM> detects the hydraulic pressure of the brake fluid in the master cylinder <NUM>, and outputs a detection result. The master-cylinder pressure sensor <NUM> may detect another physical quantity that can substantially be converted to the hydraulic pressure of the brake fluid in the master cylinder <NUM>. The master-cylinder pressure sensor <NUM> is provided in each of the front-wheel brake mechanism <NUM> and the rear-wheel brake mechanism <NUM>.

The wheel-cylinder pressure sensor <NUM> detects the hydraulic pressure of the brake fluid in the wheel cylinder <NUM>, and outputs a detection result. The wheel-cylinder pressure sensor <NUM> may detect another physical quantity that can substantially be converted to the hydraulic pressure of the brake fluid in the wheel cylinder <NUM>. The wheel-cylinder pressure sensor <NUM> is provided in each of the front-wheel brake mechanism <NUM> and the rear-wheel brake mechanism <NUM>.

The controller <NUM> controls travel of the motorcycle <NUM>.

For example, the controller <NUM> is partially or entirely constructed of a microcomputer, a microprocessor unit, or the like. Alternatively, the controller <NUM> may partially or entirely be constructed of a member in which firmware or the like can be updated, or may partially or entirely be a program module or the like that is executed by a command from a CPU or the like, for example. The controller <NUM> may be provided as one unit or may be divided into multiple units, for example.

As illustrated in <FIG>, the controller <NUM> includes an acquisition section <NUM> and a control section <NUM>, for example.

The acquisition section <NUM> acquires information that is output from each of the devices mounted on the motorcycle <NUM>, and outputs the acquired information to the control section <NUM>. For example, the acquisition section <NUM> acquires the information output from the inter-vehicular distance sensor <NUM>, the input device <NUM>, the front-wheel rotational frequency sensor <NUM>, the rear-wheel rotational frequency sensor <NUM>, the inertial measurement unit <NUM>, the lateral acceleration sensor <NUM>, the master-cylinder pressure sensor <NUM>, and the wheel-cylinder pressure sensor <NUM>.

The control section <NUM> controls operation of each of the devices mounted on the motorcycle <NUM>, so as to control the drive power and the braking force exerted on the motorcycle <NUM>.

Here, by controlling the operation of each of the devices mounted on the motorcycle <NUM>, the control section <NUM> can execute the adaptive cruise control in which the motorcycle <NUM> is made to travel according to the distance from the motorcycle <NUM> to the preceding vehicle, the motion of the motorcycle <NUM>, and the driver's instruction. More specifically, in the case where the driver selects the travel mode in which the adaptive cruise control is executed, the control section <NUM> executes the adaptive cruise control. Note that, in the case where the driver performs an accelerator operation or a brake operation during the adaptive cruise control, the control section <NUM> cancels the adaptive cruise control.

In the adaptive cruise control, the distance from the motorcycle <NUM> to the preceding vehicle is controlled to approximate a reference distance. As the distance from the motorcycle <NUM> to the preceding vehicle, the reference distance is set to a value with which the driver's safety can be secured. In the case where no preceding vehicle is recognized, a speed of the motorcycle <NUM> is controlled at a set speed, which is set in advance. In addition, in the adaptive cruise control, each of the acceleration and the deceleration of the motorcycle <NUM> is controlled to be equal to or lower than an upper limit value of such extent that does not worsen the driver's comfort.

More specifically, during the adaptive cruise control, the control section <NUM> calculates a target value of the acceleration (hereinafter referred to as target acceleration) or a target value of the deceleration (hereinafter referred to as target deceleration) on the basis of a comparison result between the distance from the motorcycle <NUM> to the preceding vehicle and the reference distance and on the basis of a relative speed between the motorcycle <NUM> and the preceding vehicle. Then, based on a calculation result, the control section <NUM> controls the drive power and the braking force exerted on the motorcycle <NUM>.

For example, in the case where the distance from the motorcycle <NUM> to the preceding vehicle is longer than the reference distance, the control section <NUM> calculates the target acceleration that corresponds to a difference between the distance from the motorcycle <NUM> to the preceding vehicle and the reference distance. On the other hand, in the case where the distance from the motorcycle <NUM> to the preceding vehicle is shorter than the reference distance, the control section <NUM> calculates the target deceleration that corresponds to the difference between the distance from the motorcycle <NUM> to the preceding vehicle and the reference distance.

The control section <NUM> includes a drive control section 62a and a brake control section 62b, for example.

The drive control section 62a controls the drive power that is transmitted to each of the wheels during the adaptive cruise control. More specifically, during the adaptive cruise control, the drive control section 62a outputs a command to motor control unit (not illustrated), which outputs a signal to control operation of each of the motors <NUM>, <NUM>, so as to control the operation of the motors <NUM>, <NUM>. As a result, during the adaptive cruise control, the drive power, which is transmitted to each of the front wheel <NUM> and the rear wheel <NUM>, is controlled.

In the normal time, the motor control unit controls the operation of the motors, <NUM>, <NUM> such that the drive power is transmitted to each of the wheels in response to the driver's accelerator operation.

Meanwhile, during the adaptive cruise control, the drive control section 62a controls the operation of the motors <NUM>, <NUM> such that the drive power is transmitted to each of the wheels without relying on the driver's accelerator operation. More specifically, during the adaptive cruise control, the drive control section 62a controls the operation of the motors <NUM>, <NUM> such that the acceleration of the motorcycle <NUM> becomes the target acceleration, which is calculated on the basis of the distance from the motorcycle <NUM> to the preceding vehicle and the relative speed between the motorcycle <NUM> and the preceding vehicle. In this way, the drive control section 62a controls the drive power transmitted to each of the wheels.

Here, during the adaptive cruise control, the drive control section 62a separately controls the operation of each of the motors <NUM>, <NUM>. In this way, the drive control section 62a can separately control the drive power that is output from each of the motor <NUM> and the motor <NUM>, and thus can control drive power distribution that is distribution of the drive power transmitted to the wheels to the front and rear wheels (that is, distribution of the drive power transmitted to the front wheel <NUM> and the drive power transmitted to the rear wheel <NUM>). More specifically, the drive control section 62a controls the drive power distribution between the front and rear wheels such that a total of target drive power values transmitted to the wheels becomes equal to requested drive power (that is, the drive power that is requested at the time of driving the vehicle during the adaptive cruise control) corresponding to the target acceleration. The requested drive power is specifically the required drive power to bring the acceleration of the motorcycle <NUM> to the target acceleration, which is calculated on the basis of the distance from the motorcycle <NUM> to the preceding vehicle and the relative speed between the motorcycle <NUM> and the preceding vehicle.

The brake control section 62b controls the operation of each of the components of the hydraulic pressure control unit <NUM> in the brake system <NUM>, so as to control the braking force generated on each of the wheels of the motorcycle <NUM>.

In the normal time, as described above, the brake control section 62b controls the operation of each of the components of the hydraulic pressure control unit <NUM> such that the braking force is generated on each of the wheels in response to the driver's brake operation.

Meanwhile, during the adaptive cruise control, the brake control section 62b controls the operation of each of the components such that the braking force is generated on each of the wheels without relying on the driver's brake operation. More specifically, during the adaptive cruise control, the brake control section 62b controls the operation of each of the components of the hydraulic pressure control unit <NUM> such that the deceleration of the motorcycle <NUM> becomes the target deceleration, which is calculated on the basis of the distance from the motorcycle <NUM> to the preceding vehicle and the relative speed between the motorcycle <NUM> and the preceding vehicle. In this way, the brake control section 62b controls the braking force generated on each of the wheels.

For example, during the adaptive cruise control, the brake control section 62b brings the motorcycle <NUM> into a state where the inlet valves <NUM> are opened, the outlet valves <NUM> are closed, the first valves <NUM> are closed, and the second valves <NUM> are opened, and drives the pumps <NUM> in such a state, so as to increase the hydraulic pressure of the brake fluid in each of the wheel cylinders <NUM> and generate the braking force on each of the wheels. In addition, the brake control section 62b regulates the hydraulic pressure of the brake fluid in each of the wheel cylinders <NUM> by controlling an opening amount of the first valve <NUM>, for example. In this way, the brake control section 62b can control the braking force generated on each of the wheels.

Here, during the adaptive cruise control, the brake control section 62b separately controls operation of the front-wheel brake mechanism <NUM> and the rear-wheel brake mechanism <NUM>, so as to separately control the hydraulic pressure of the brake fluid in each of the wheel cylinders <NUM> of the front-wheel brake mechanism <NUM> and the rear-wheel brake mechanism <NUM>. In this way, the brake control section 62b can control braking force distribution that is distribution of the braking force generated on the wheels to the front and rear wheels (that is, distribution of the braking force generated on the front wheel <NUM> and the braking force generated on the rear wheel <NUM>). More specifically, the brake control section 62b controls the braking force distribution between the front and rear wheels such that a total of target braking force values generated on the wheels becomes equal to a requested braking force (that is, the braking force that is requested at the time of braking during the adaptive cruise control) corresponding to the target deceleration. The requested braking force is specifically the required braking force to bring the deceleration of the motorcycle <NUM> to the target deceleration, which is calculated on the basis of the distance from the motorcycle <NUM> to the preceding vehicle and the relative speed between the motorcycle <NUM> and the preceding vehicle.

Note that, in the case where at least one of the wheels is locked or possibly locked, the brake control section 62b may execute the anti-lock brake control. The anti-lock brake control is control for regulating the braking force of the wheel, which is locked or possibly locked, to such a magnitude that locking of the wheel can be avoided.

For example, during the anti-lock brake control, the brake control section 62b brings the motorcycle <NUM> into a state where the inlet valves <NUM> are closed, the outlet valves <NUM> are opened, the first valves <NUM> are opened, and the second valves <NUM> are closed, and drives the pumps <NUM> in such a state, so as to reduce the hydraulic pressure of the brake fluid in each of the wheel cylinders <NUM> and reduce the braking force generated on each of the wheels. In addition, the brake control section 62b closes both of the inlet valves <NUM> and the outlet valves <NUM> from the above state, for example. In this way, the brake control section 62b can keep the hydraulic pressure of the brake fluid in each of the wheel cylinders <NUM> and thus can keep the braking force generated on the each of wheels. Furthermore, the brake control section 62b opens the inlet valves <NUM> and closes the outlet valves <NUM> from the above state, for example. In this way, the brake control section 62b can increase the hydraulic pressure of the brake fluid in each of the wheel cylinders <NUM> and thus can increase the braking force generated on each of the wheels.

As described above, in the controller <NUM>, the control section <NUM> can execute the adaptive cruise control. Here, during the adaptive cruise control, the control section <NUM> controls at least one of the braking force distribution and the drive power distribution between the front and rear wheels on the basis of the lateral acceleration of the motorcycle <NUM>. As a result, the motorcycle <NUM> can appropriately corner during the adaptive cruise control of the motorcycle <NUM>. A detailed description will be made below on processing relating to such braking force distribution control based on the lateral acceleration and processing relating to such drive power distribution control based on the lateral acceleration during the adaptive cruise control executed by the controller <NUM>.

Note that, as the lateral acceleration of the motorcycle <NUM> that is referred in the braking force distribution control and the drive power distribution control, the control section <NUM> may use the detection result of the lateral acceleration sensor <NUM> or may use a value that is calculated by using another type of information acquired by the controller <NUM>. For example, the control section <NUM> may calculate a vehicle speed on the basis of the front-wheel rotational frequency sensor <NUM> and the rear-wheel rotational frequency sensor <NUM>, and then may calculate the lateral acceleration on the basis of the vehicle speed and a turning radius. For example, the turning radius can be acquired by using a signal received from the Global Positioning System (GPS) satellite.

In the motorcycle <NUM> described above, the braking force generated on each of the wheels can separately be controlled between the front and rear wheels, and the drive power transmitted to each of the wheels can also separately be controlled between the front and rear wheels. However, in the straddle-type vehicle using the controller according to the present invention, at least one of the braking force and the drive power only needs to be separately controllable between the front and rear wheels. Thus, the straddle-type vehicle using the controller according to the present invention may be a straddle-type vehicle on which the engine is mounted as the drive source and in which the drive power is transmitted only to the rear wheel <NUM> from the engine, for example.

The description has been made above on the example in which the drive control section 62a controls the operation of the motors <NUM>, <NUM> via the motor control unit. However, the drive control section 62a may output a signal for controlling the operation of the motors <NUM>, <NUM>, so as to directly control the operation of the motors <NUM>, <NUM>. In such a case, similar to the operation of the motors <NUM>, <NUM> during the adaptive cruise control, the operation of the motors <NUM>, <NUM> in the normal time is also controlled by the drive control section 62a.

A description will be made on operation of the controller <NUM> according to the embodiment of the present invention with reference to <FIG>.

<FIG> is a flowchart of an exemplary processing flow relating to the braking force distribution control that is based on the lateral acceleration and executed by the controller <NUM>. More specifically, the control flow illustrated in <FIG> is repeatedly executed during the adaptive cruise control. In addition, step S510 and step S590 in <FIG> respectively correspond to initiation and termination of the control flow illustrated in <FIG>. <FIG> is a view for illustrating directions of the braking forces generated on the front wheel <NUM> and the rear wheel <NUM> during cornering.

When the control flow illustrated in <FIG> is initiated, in step S511, the control section <NUM> determines whether the lean angle of the motorcycle <NUM> is smaller than a first reference angle. If it is determined that the lean angle of the motorcycle <NUM> is smaller than the first reference angle (step S511/YES), the processing proceeds to step S513. On the other hand, if it is determined that the lean angle of the motorcycle <NUM> is equal to or larger than the first reference angle (step S511/NO), the processing proceeds to step S515.

During cornering, when passing an entry of a curved road (that is, when the motorcycle <NUM> passes the entry of the curved road), the driver leans the motorcycle <NUM> while the motorcycle <NUM> is decelerating. In this way, the lean angle is increased. Then, after the motorcycle <NUM> finishes passing the entry of the curved road, the driver maintains the lean angle while the motorcycle <NUM> is traveling on the curved road (more specifically, in a period from time at which the motorcycle <NUM> passes the entry of the curved road to time at which the motorcycle <NUM> enters an exit thereof). In such a state, the motorcycle <NUM> is automatically accelerated or decelerated. Here, the entry of the curved road means a connected portion between the curved road and a straight road that is located behind the curved road and is connected thereto. In addition, when the motorcycle <NUM> is passing the entry of the curved road, the adaptive cruise control is executed, and the acceleration or the deceleration of the motorcycle <NUM> is controlled. As a result, the motorcycle <NUM> is decelerated.

More specifically, the first reference angle described above is set to an angle with which it is possible to appropriately determine whether a current time point is the time at which the motorcycle <NUM> is passing the entry of the curved road or the time at which the motorcycle <NUM> finishes passing the entry of the curved road under a situation where the motorcycle <NUM> is decelerated during cornering. For example, the first reference angle is set to a smaller angle than an average angle that is estimated as the lean angle of the motorcycle <NUM> leaned by the driver when the motorcycle <NUM> passes the entry of the curved road. Thus, if it is determined YES in step S511 under the situation where the motorcycle <NUM> is decelerated during cornering, it is possible to determine that the current time point is the time at which the motorcycle <NUM> is passing the entry of the curved road. On the other hand, if it is determined NO in step S511, it is possible to determine that the current time point is the time at which the motorcycle <NUM> is traveling on the curved road.

If it is determined YES in step S511, in step S513, the brake control section 62b switches a control mode of the braking force distribution to a first braking mode.

In the first braking mode, the brake control section 62b controls the braking force distribution such that the lateral acceleration becomes such acceleration that increases the lean angle of the motorcycle <NUM>.

Here, the description will be made on the directions of the braking forces generated on the front wheel <NUM> and the rear wheel <NUM> during cornering with reference to <FIG> illustrates a state where the braking force is generated on each of the wheels under a situation where the motorcycle <NUM> turns in a left direction with respect to an advancing direction D1.

As illustrated in <FIG>, during cornering, a direction of a braking force FB_f generated on the front wheel <NUM> differs from a direction of a braking force FB_r generated on the rear wheel <NUM>. For example, in the case where the motorcycle <NUM> turns in the left direction with respect to the advancing direction D1, as illustrated in <FIG>, the braking force FB_f generated on the front wheel <NUM> has: a component FB_fx in a reverse direction from the advancing direction D1; and a component FB_fy that is orthogonal to the component FB_fx and is in a right direction with respect to the advancing direction D1. Meanwhile, the braking force FB_r generated on the rear wheel <NUM> has: a component FB_rx in the reverse direction from the advancing direction D1; and a component FB_ry that is orthogonal to the component FB_rx and is in the left direction with respect to the advancing direction D1.

For example, in the case where the motorcycle <NUM> turns in the left direction with respect to the advancing direction D1, the motorcycle <NUM> is leaned in the left direction with respect to the advancing direction D1. Since the braking force FB_f generated on the front wheel <NUM> has the component FB_fy in the right direction with respect to the advancing direction D1, the braking force FB_f acts in a direction to reduce the lean angle of the motorcycle <NUM> (in other words, a direction to stand the motorcycle <NUM> up). Meanwhile, since the braking force FB_r generated on the rear wheel <NUM> has the component FB_ry in the left direction with respect to the advancing direction D1, the braking force FB_r acts in a direction to increase the lean angle of the motorcycle <NUM> (in other words, a direction to lean the motorcycle <NUM>).

Note that, also in the case where the motorcycle <NUM> turns in the right direction with respect to the advancing direction D1, similar to the case where the motorcycle <NUM> turns in the left direction with respect to the advancing direction D1, the braking force generated on the front wheel <NUM> acts in the direction to reduce the lean angle of the motorcycle <NUM>, and the braking force generated on the rear wheel <NUM> acts in the direction to increase the lean angle of the motorcycle <NUM>.

More specifically, in the first braking mode, the brake control section 62b controls the braking force distribution such that a direction of a component of the lateral acceleration in the motorcycle <NUM> corresponding to lateral components of the braking forces generated on the front wheel <NUM> and the rear wheel <NUM> (that is, components in the vehicle width direction) matches a lean direction of the motorcycle <NUM> (for example, the left direction with respect to the advancing direction D1 in the example illustrated in <FIG>).

For example, in the example illustrated in <FIG>, the brake control section 62b preferentially distributes the braking force to the rear wheel <NUM> to the front wheel <NUM> (that is, a distribution ratio of the braking force distribution is set to be high for the rear wheel <NUM>). In this way, the component FB_ry of the braking force FB_r generated on the rear wheel <NUM> can be made larger than the component FB_fy of the braking force FB_f generated on the front wheel <NUM>. As a result, the direction of the component of the lateral acceleration in the motorcycle <NUM> that corresponds to the lateral components of the braking forces generated on the front wheel <NUM> and the rear wheel <NUM> can be set to the left direction with respect to the advancing direction D1. In this way, a force that leans the motorcycle <NUM> can be generated.

Here, the case where it is determined YES in step S511 under the situation where the motorcycle <NUM> is decelerated during cornering corresponds to the case where the current time point is the time at which the motorcycle <NUM> is passing the entry of the curved road as described above. Thus, more specifically, under the situation where the motorcycle <NUM> is decelerated during cornering, the first braking mode is executed when the motorcycle <NUM> is passing the entry of the curved road. As a result, the force that leans the motorcycle <NUM> can be generated when motorcycle <NUM> is passing the entry of the curved road. Thus, behavior of the motorcycle <NUM> in the rolling direction can be controlled according to the driver's intention.

Note that, from a perspective of suppressing falling of the motorcycle <NUM>, in the first braking mode, the brake control section 62b preferably controls the braking force distribution such that the component of the lateral acceleration in the motorcycle <NUM> corresponding to the lateral components of the braking forces generated on the front wheel <NUM> and the rear wheel <NUM> becomes equal to or lower than an upper limit value of such extent that can appropriately suppress the falling of the motorcycle <NUM>.

If it is determined NO in step S511, in step S515, the brake control section 62b switches the control mode of the braking force distribution to a second braking mode.

In the second braking mode, the brake control section 62b controls the braking force distribution such that the lateral acceleration is maintained.

More specifically, in the second braking mode, the brake control section 62b controls the braking force distribution such that the lateral acceleration is maintained without relying on the braking forces generated on the front wheel <NUM> and the rear wheel <NUM>.

For example, in the example illustrated in <FIG>, the brake control section 62b controls the braking force distribution such that a magnitude of the component FB_fy of the braking force FB_f generated on the front wheel <NUM> matches a magnitude of the component FB_ry of the braking force FB_r generated on the rear wheel <NUM>. As a result, the component FB_f y of the braking force FB_f generated on the front wheel <NUM> and the component FB_ry of the braking force FB_r generated on the rear wheel <NUM> can cancel each other out. Thus, the lateral acceleration of the motorcycle <NUM> can be maintained as a centrifugal force in the right direction with respect to the advancing direction D1, which is generated by turning of the motorcycle <NUM>, without relying on the braking forces generated on the front wheel <NUM> and the rear wheel <NUM>.

Here, the case where it is determined NO in step S511 under the situation where the motorcycle <NUM> is decelerated during cornering corresponds to the case where the current time point is the time at which the motorcycle <NUM> is traveling on the curved road as described above. Thus, the second braking mode is executed under the situation where the motorcycle <NUM> is decelerated during cornering, more specifically, when the motorcycle <NUM> is traveling on the curved road. As a result, the lateral acceleration of the motorcycle <NUM> can be maintained as the centrifugal force without relying on the braking forces generated on the front wheel <NUM> and the rear wheel <NUM> when the motorcycle <NUM> is traveling on the curved road. Thus, it is possible to suppress a change in the posture of the motorcycle <NUM> in the rolling direction against the driver's intention.

After step S513 or step S515, the control flow illustrated in <FIG> is terminated.

As described above, in the first braking mode and the second braking mode, the brake control section 62b controls the braking force distribution on the basis of the lateral acceleration of the motorcycle <NUM>. In addition, the brake control section 62b controls the braking force distribution, which is controlled on the basis of the lateral acceleration, according to the lean angle of the motorcycle <NUM>.

The description has been made above on the example in which the control mode of the braking force distribution is switched according to the comparison result between the lean angle of the motorcycle <NUM> and the first reference angle. However, a trigger to switch the control mode of the braking force distribution is not limited to the above example.

For example, the brake control section 62b may identify a position of the motorcycle <NUM> on the curved road and may switch the control mode of the braking force distribution according to the identified position of the motorcycle <NUM>. More specifically, in the case where it is determined that the motorcycle <NUM> is passing the entry of the curved road on the basis of the identified position of the motorcycle <NUM>, the brake control section 62b switches the control mode of the braking force distribution to the first braking mode. Meanwhile, in the case where it is determined that the motorcycle <NUM> finishes passing the entry and is traveling on the curved road on the basis of the identified position of the motorcycle <NUM>, the brake control section 62b switches the control mode of the braking force distribution to the second braking mode. Note that the position of the motorcycle <NUM> on the curved road can be identified, for example, by using the signal received from the GPS satellite, by recognizing a shape of a travel road ahead by using the image in front of the motorcycle <NUM> captured by the camera, or the like.

<FIG> is a flowchart of an exemplary processing flow relating to the drive power distribution control that is based on the lateral acceleration and executed by the controller <NUM>. More specifically, the control flow illustrated in <FIG> is repeatedly executed during the adaptive cruise control. In addition, step S610 and step S690 in <FIG> respectively correspond to initiation and termination of the control flow illustrated in <FIG>. <FIG> is a view for illustrating directions of the drive power that acts on the front wheel <NUM> and the rear wheel <NUM> during cornering.

When the control flow illustrated in <FIG> is initiated, in step S611, the control section <NUM> determines whether the lean angle of the motorcycle <NUM> is equal to or larger than a second reference angle. If it is determined that the lean angle of the motorcycle <NUM> is equal to or larger than the second reference angle (step S611/YES), the processing proceeds to step S613. On the other hand, if it is determined that the lean angle of the motorcycle <NUM> is smaller than the second reference angle (step S611/NO), the processing proceeds to step S615.

Here, during cornering, as described above, after the motorcycle <NUM> finishes passing the entry of the curved road, the driver maintains the lean angle while the motorcycle <NUM> is traveling on the curved road. In such a state, the motorcycle <NUM> is automatically accelerated or decelerated. Then, at the time of passing an exit of the curved road (that is, when the motorcycle <NUM> passes the exit of the curved road), the driver stands the motorcycle <NUM> up while accelerating the motorcycle <NUM>. In this way, the lean angle is reduced. Here, the exit of the curved road means a connected portion between the curved road and a straight road that is located ahead of the curved road and is connected thereto. In addition, when the motorcycle <NUM> is passing the exit of the curved road, the adaptive cruise control is executed, and the acceleration or the deceleration of the motorcycle <NUM> is controlled. As a result, the motorcycle <NUM> is accelerated.

More specifically, the second reference angle described above is set to an angle with which it is possible to appropriately determine whether the current time point is the time at which the motorcycle <NUM> is passing the exit of the curved road or the time before the motorcycle <NUM> enters the exit of the curved road under a situation where the motorcycle <NUM> is accelerated during cornering. For example, the second reference angle is set to a smaller angle than an average angle that is estimated as the lean angle of the motorcycle <NUM> that starts being stood up by the driver when the motorcycle <NUM> enters the exit of the curved road. Thus, if it is determined YES in step S611 under the situation where the motorcycle <NUM> is accelerated during cornering, it is possible to determine that the current time point is the time at which the motorcycle <NUM> is traveling on the curved road. On the other hand, if it is determined NO in step S611, it is possible to determine that the current time point is the time at which the motorcycle <NUM> is passing the exit of the curved road.

If it is determined YES in step S611, in step S613, the drive control section 62a switches a control mode of the drive power distribution to a first drive mode.

In the first drive mode, the drive control section 62a controls the drive power distribution such that the lateral acceleration is maintained.

Here, the description will be made on the directions of the drive power that acts on the front wheel <NUM> and the rear wheel <NUM> during cornering with reference to <FIG> illustrates a state where the drive power acts on each of the wheels under the situation where the motorcycle <NUM> turns in the left direction with respect to the advancing direction D1.

As illustrated in <FIG>, during cornering, a direction of drive power FD_f acting on the front wheel <NUM> differs from a direction of drive power FD_r acting on the rear wheel <NUM>. For example, in the case where the motorcycle <NUM> turns in the left direction with respect to the advancing direction D1, as illustrated in <FIG>, the drive power FD_f acting on the front wheel <NUM> has: a component FD_fx in the advancing direction D1; and a component FD_fy that is orthogonal to the component FD_fx and is in the left direction with respect to the advancing direction D1. Meanwhile, the drive power FD_r acting on the rear wheel <NUM> has: a component FD_rx in the advancing direction D1; and a component FD_ry that is orthogonal to the component FD_rx and is in the right direction with respect to the advancing direction D1.

For example, in the case where the motorcycle <NUM> turns in the left direction with respect to the advancing direction D1, the motorcycle <NUM> is leaned in the left direction with respect to the advancing direction D1. Since the drive power FD_f acting on the front wheel <NUM> has the component FD_fy in the left direction with respect to the advancing direction D1, the drive power FD_f acts in the direction to increase the lean angle of the motorcycle <NUM> (in other words, the direction to lean the motorcycle <NUM>). Meanwhile, since the drive power FD_r acting on the rear wheel <NUM> has the component FD_ry in the right direction with respect to the advancing direction D1, the drive power FD_r acts in the direction to reduce the lean angle of the motorcycle <NUM> (in other words, the direction to stand the motorcycle <NUM> up).

Note that, also in the case where the motorcycle <NUM> turns in the right direction with respect to the advancing direction D1, similar to the case where the motorcycle <NUM> turns in the left direction with respect to the advancing direction D1, the drive power acting on the front wheel <NUM> acts in the direction to increase the lean angle of the motorcycle <NUM>, and the drive power acting on the rear wheel <NUM> acts in the direction to reduce the lean angle of the motorcycle <NUM>.

More specifically, in the first drive mode, the drive control section 62a controls the drive power distribution such that the lateral acceleration is maintained without relying on the drive power acting on the front wheel <NUM> and the rear wheel <NUM>.

For example, in the example illustrated in <FIG>, the drive control section 62a controls the drive power distribution such that a magnitude of the component FD_fy of the drive power FD_f acting on the front wheel <NUM> matches a magnitude of the component FD_ry of the drive power FD_r acting on the rear wheel <NUM>. As a result, the component FD_fy of the drive power FD_f acting on the front wheel <NUM> and the component FD_ry of the drive power FD_r acting on the rear wheel <NUM> can cancel each other out. Thus, the lateral acceleration of the motorcycle <NUM> can be maintained as the centrifugal force in the right direction with respect to the advancing direction D1, which is generated by turning of the motorcycle <NUM>, without relying on the drive power acting on the front wheel <NUM> and the rear wheel <NUM>.

Here, the case where it is determined YES in step S611 under the situation where the motorcycle <NUM> is accelerated during cornering corresponds to the case where the current time point is the time at which the motorcycle <NUM> is traveling on the curved road as described above. Thus, the first drive mode is executed under the situation where the motorcycle <NUM> is accelerated during cornering, more specifically, when the motorcycle <NUM> is traveling on the curved road. As a result, the lateral acceleration of the motorcycle <NUM> can be maintained as the centrifugal force without relying on the drive power acting on the front wheel <NUM> and the rear wheel <NUM> when the motorcycle <NUM> is traveling on the curved road. Thus, it is possible to suppress the change in the posture of the motorcycle <NUM> in the rolling direction against the driver's intention.

If it is determined NO in step S611, in step S615, the drive control section 62a switches the control mode of the drive power distribution to a second drive mode.

In the second drive mode, the drive control section 62a controls the drive power distribution such that the lateral acceleration becomes such acceleration that reduces the lean angle of the motorcycle <NUM>.

More specifically, in the second drive mode, the drive control section 62a controls the drive power distribution such that the direction of the component of the lateral acceleration in the motorcycle <NUM> corresponding to lateral components of the drive power acting on the front wheel <NUM> and the rear wheel <NUM> (that is, components in the vehicle width direction) matches a reverse direction from the lean direction of the motorcycle <NUM> (for example, the right direction with respect to the advancing direction D1 in the example illustrated in <FIG>).

For example, in the example illustrated in <FIG>, the drive control section 62a preferentially distributes the drive power to the rear wheel <NUM> to the front wheel <NUM> (that is, a distribution ratio of the drive power distribution is set to be high for the rear wheel <NUM>). In this way, the component FD_ry of the drive power FD_r acting on the rear wheel <NUM> can be made larger than the component FD_fy of the drive power FD_f acting on the front wheel <NUM>. As a result, the direction of the component of the lateral acceleration in the motorcycle <NUM> that corresponds to the lateral components of the drive power acting on the front wheel <NUM> and the rear wheel <NUM> can be set to the right direction with respect to the advancing direction D1. In this way, a force that stands the motorcycle <NUM> up can be generated.

Here, the case where it is determined NO in step S611 under the situation where the motorcycle <NUM> is accelerated during cornering corresponds to the case where the current time point is the time at which the motorcycle <NUM> is passing the exit of the curved road as described above. Thus, the second drive mode is executed under the situation where the motorcycle <NUM> is accelerated during cornering, more specifically, when the motorcycle <NUM> is passing the exit of the curved road. As a result, the force that stands the motorcycle <NUM> up can be generated when motorcycle <NUM> is passing the exit of the curved road. Thus, the behavior of the motorcycle <NUM> in the rolling direction can be controlled according to the driver's intention.

Note that, from the perspective of suppressing the falling of the motorcycle <NUM>, in the second drive mode, the drive control section 62a preferably controls the drive power distribution such that the component of the lateral acceleration in the motorcycle <NUM> corresponding to the lateral components of the drive power acting on the front wheel <NUM> and the rear wheel <NUM> becomes equal to or lower than the upper limit value of such extent that can appropriately suppress the falling of the motorcycle <NUM>.

After step S613 or step S615, the control flow illustrated in <FIG> is terminated.

As described above, in the first drive mode and the second drive mode, the drive control section 62a controls the drive power distribution on the basis of the lateral acceleration of the motorcycle <NUM>. In addition, the drive control section 62a controls the drive power distribution, which is controlled on the basis of the lateral acceleration, according to the lean angle of the motorcycle <NUM>.

The description has been made above on the example in which the control mode of the drive power distribution is switched according to the comparison result between the lean angle of the motorcycle <NUM> and the second reference angle. However, a trigger to switch the control mode of the drive power distribution is not limited to the above example.

For example, the drive control section 62a may identify the position of the motorcycle <NUM> on the curved road and may switch the control mode of the drive power distribution according to the identified position of the motorcycle <NUM>. More specifically, in the case where it is determined that the motorcycle <NUM> is traveling on the curved road before entering the exit on the basis of the identified position of the motorcycle <NUM>, the drive control section 62a switches the control mode of the drive power distribution to the first drive mode. Meanwhile, in the case where it is determined that the motorcycle <NUM> is passing the exit of the curved road on the basis of the identified position of the motorcycle <NUM>, the drive control section 62a switches the control mode of the drive power distribution to the second drive mode.

A description will be made on effects of the controller <NUM> according to the embodiment of the present invention.

In the controller <NUM>, during the adaptive cruise control, the control section <NUM> controls at least one of the braking force distribution, which is the distribution of the braking forces generated on the wheels of the motorcycle <NUM> to the front and rear wheels, and the drive power distribution, which is the distribution of the drive power transmitted to the wheels to the front and rear wheels, on the basis of the lateral acceleration of the motorcycle <NUM>. In this way, during cornering, it is possible to suppress the motorcycle <NUM> from exhibiting the behavior in the rolling direction that is unintended by the driver and is caused when the braking force or the drive power is automatically exerted on the motorcycle <NUM>. Therefore, the motorcycle <NUM> can appropriately corner during the adaptive cruise control of the motorcycle <NUM>.

In the controller <NUM>, the control section <NUM> preferably controls the braking force distribution or the drive power distribution, which is controlled on the basis of the lateral acceleration, according to the lean angle of the motorcycle <NUM>. In this way, the braking force distribution or the drive power distribution, which is controlled according to the lateral acceleration, can appropriately be controlled according to the position of the motorcycle <NUM> on the curved road. Thus, during cornering, it is possible to further appropriately suppress the motorcycle <NUM> from exhibiting the behavior in the rolling direction that is unintended by the driver and is caused when the braking force or the drive power is automatically exerted on the motorcycle <NUM>. Therefore, the motorcycle <NUM> can appropriately corner during the adaptive cruise control of the motorcycle <NUM>.

In the case where the lean angle of the motorcycle <NUM> is smaller than the first reference angle, the control section <NUM> of the controller <NUM> preferably executes the first braking mode in which the braking force distribution is controlled such that the lateral acceleration becomes such acceleration that increases the lean angle of the motorcycle <NUM>. In this way, the first braking mode can be executed when the motorcycle <NUM> is passing the entry of the curved road where the driver leans the motorcycle <NUM>. As a result, the force that leans the motorcycle <NUM> can be generated when motorcycle <NUM> is passing the entry of the curved road. Thus, the behavior of the motorcycle <NUM> in the rolling direction can be controlled according to the driver's intention.

In the case where the lean angle of the motorcycle <NUM> is equal to or larger than the first reference angle, the control section <NUM> of the controller <NUM> preferably executes the second braking mode in which the braking force distribution is controlled such that the lateral acceleration is maintained. In this way, the second braking mode can be executed when the motorcycle <NUM> is traveling on the curved road where the driver maintains the lean angle of the motorcycle <NUM>. As a result, the lateral acceleration of the motorcycle <NUM> can be maintained as the centrifugal force without relying on the braking forces generated on the front wheel <NUM> and the rear wheel <NUM> when the motorcycle <NUM> is traveling on the curved road. Thus, it is possible to suppress the change in the posture of the motorcycle <NUM> in the rolling direction against the driver's intention.

In the case where the lean angle of the motorcycle <NUM> is equal to or larger than the second reference angle, the control section <NUM> of the controller <NUM> preferably executes the first drive mode in which the drive power distribution is controlled such that the lateral acceleration is maintained. In this way, the first drive mode can be executed when the motorcycle <NUM> is traveling on the curved road where the driver maintains the lean angle of the motorcycle <NUM>. As a result, the lateral acceleration of the motorcycle <NUM> can be maintained as the centrifugal force without relying on the drive power acting on the front wheel <NUM> and the rear wheel <NUM> when the motorcycle <NUM> is traveling on the curved road. Thus, it is possible to suppress the change in the posture of the motorcycle <NUM> in the rolling direction against the driver's intention.

In the case where the lean angle of the motorcycle <NUM> is smaller than the second reference angle, the control section <NUM> of the controller <NUM> preferably executes the second drive mode in which the drive power distribution is controlled such that the lateral acceleration becomes such acceleration that reduces the lean angle of the motorcycle <NUM>. In this way, the second drive mode can be executed when the motorcycle <NUM> is passing the exit of the curved road where the driver stands the motorcycle <NUM> up. As a result, the force that stands the motorcycle <NUM> up can be generated when motorcycle <NUM> is passing the exit of the curved road. Thus, the behavior of the motorcycle <NUM> in the rolling direction can be controlled according to the driver's intention.

Claim 1:
A controller (<NUM>) that controls travel of a straddle-type vehicle (<NUM>), the controller comprising:
a control section (<NUM>) capable of executing adaptive cruise control in which the straddle-type vehicle (<NUM>) is made to travel according to a distance from said straddle-type vehicle (<NUM>) to a preceding vehicle, motion of said straddle-type vehicle (<NUM>), and a driver's instruction, wherein:
during the adaptive cruise control, the control section (<NUM>) controls braking force distribution, which is distribution of braking forces generated on a front wheel (<NUM>) and a rear wheel (<NUM>) of the straddle-type vehicle (<NUM>) on the basis of a lateral acceleration of the straddle-type vehicle (<NUM>) according to a lean angle of the straddle-type vehicle (<NUM>);
the control section (<NUM>), in the case where the lean angle of the straddle-type vehicle (<NUM>) is smaller than a first reference angle, determines that the straddle-type vehicle (<NUM>) is passing an entry of a curved road, and executes a first braking mode in which the braking force distribution is controlled such that the lateral acceleration becomes such acceleration that increases the lean angle of the straddle-type vehicle (<NUM>); and
the control section (<NUM>), in the case where the lean angle of the straddle-type vehicle (<NUM>) is equal to or larger than the first reference angle, determines that the straddle-type vehicle (<NUM>) is traveling on the curved road, and executes a second braking mode in which the braking force distribution is controlled such that the lateral acceleration is maintained.