Patent Description:
As a conventional technique related to a motorcycle, a technique of improving driver safety has been available.

For example, a driver assistance system is disclosed in PTL <NUM>. Based on information detected by a sensor device that detects an obstacle present in a travel direction or substantially in the travel direction, the driver assistance system warns a driver of the motorcycle that the motorcycle inappropriately approaches the obstacle.

PTL <NUM> discloses a control device and a control method by performing an automatic emergency deceleration operation while preventing rollover of a motorcycle, wherein a control mode for causing a motorcycle to perform an automatic emergency deceleration operation is initiated in response to trigger information generated in accordance with the environment around the motorcycle.

PTL <NUM> discloses a longitudinal force control apparatus.

By the way, in order to further improve the driver safety, it is considered to use a technique of avoiding a collision with the forward obstacle by causing the motorcycle to take automatic emergency deceleration action that is action to stop the motorcycle at a position before the forward obstacle without depending on a driver's operation. The motorcycle tends to have unstable posture when compared to a four-wheeled vehicle, for example. This leads to such a problem that the motorcycle possibly falls over due to deceleration of the motorcycle generated by the automatic emergency deceleration action.

The invention has been made with the above-described problem as the background and therefore obtains a controller and a control method capable of improving safety by automatic emergency deceleration action while suppressing a motorcycle from falling over. The invention also obtains a brake system that includes such a controller.

The present invention provides a controller that is configured to control behavior of a motorcycle, according to claim <NUM>.

The present invention provides a control method that controls behavior of a motorcycle, according to claim <NUM>.

The present invention provides a brake system according to claim <NUM>.

In the controller, the control method, and the brake system according to the invention, the control mode that causes the motorcycle to take the automatic emergency deceleration action is initiated in response to the trigger information generated in accordance with the peripheral environment of the motorcycle. In the control mode, the automatic emergency deceleration that is the deceleration of the motorcycle generated by the automatic emergency deceleration action is controlled in accordance with the change rate of the state amount that is related to the posture of the motorcycle during the turning travel. In this way, the automatic emergency deceleration can appropriately be controlled in accordance with the posture of the motorcycle. Therefore, safety can be improved by the automatic emergency deceleration action while the motorcycle is suppressed from falling over.

A description will hereinafter be made on a controller, a control method, and a brake system according to the invention by using the drawings. Note that a description will hereinafter be made on a case where a motorcycle is a two-wheeled motor vehicle; however, the motorcycle may be another motorcycle such as a three-wheeled motor vehicle. A description will also be made on a case where each of a front-wheel brake mechanism and a rear-wheel brake mechanism is provided in one unit; however, at least one of the front-wheel brake mechanism and the rear-wheel brake mechanism may be provided in multiple units.

In addition, each of a configuration, action, and the like, which will be described below, is merely one example. The controller, the control method, and the brake system according to the invention are not limited to a case with such a configuration, such action, and the like.

Furthermore, the same or similar description will appropriately be simplified or will not be made. 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 depicted in a simplified manner or will not be depicted.

A description will be made on a configuration of a brake system <NUM> according to an embodiment of the invention. <FIG> is a schematic view of one example of an outline configuration of a motorcycle <NUM> on which the brake system <NUM> according to the embodiment of the invention is mounted. <FIG> is a schematic view of one example of an outline configuration of the brake system <NUM> according to the embodiment of the invention. <FIG> is a block diagram of one example of a functional configuration of a controller <NUM> according to the embodiment of the invention. <FIG> is a view that explains a lean angle.

As depicted in <FIG> and <FIG>, the brake system <NUM> is mounted on the motorcycle <NUM>. 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>; and a rear wheel <NUM> that is held by the trunk <NUM> in a freely rotatable manner.

For example, 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 the interlocking manner with at least the second brake operation section <NUM>.

The first brake operation section <NUM> is provided on the handlebar <NUM> and operated by a 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 operated by a 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 depicted) 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 depicted) ; 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> is delivered to 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. A first valve (USV) <NUM> is provided in a portion of the primary channel <NUM> between an end thereof on the master cylinder <NUM> side and a portion thereof to which a downstream end of the secondary channel <NUM> is connected. The supply channel <NUM> communicates between the master cylinder <NUM> and a suction side of the pump <NUM> in the secondary channel <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 is closed in an energized state, for example. The outlet valve <NUM> is an electromagnetic valve that is closed in the unenergized state and is opened in the energized state, for example. The first valve <NUM> is an electromagnetic valve that is opened in the unenergized state and is closed in the energized state, for example. The second valve <NUM> is an electromagnetic valve that is closed in the unenergized state and is opened in the energized state, for example.

A hydraulic pressure control unit <NUM> is configured by including: members 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>; a base body <NUM> that is provided with those members and is formed with channels constituting the primary channels <NUM>, the secondary channels <NUM>, and the supply channels <NUM> therein; and the controller (ECU) <NUM>. In the brake system <NUM>, the hydraulic pressure control unit <NUM> is a unit that has a function of controlling a hydraulic pressure of the brake fluid in each of the wheel cylinders <NUM>, that is, a braking force to be applied to the front wheel <NUM> by the front-wheel brake mechanism <NUM> and a braking force to be applied to the rear wheel <NUM> by the rear-wheel brake mechanism <NUM>.

The members may collectively be provided in the single base body <NUM> or may separately be provided in the multiple base bodies <NUM>. In addition, the controller <NUM> may be provided as one unit or may be divided into multiple units. Furthermore, the controller <NUM> may be attached to the base body <NUM> or may be attached to a member other than the base body <NUM>. Moreover, the controller <NUM> may partially or entirely be constructed of a microcomputer, a microprocessor unit, or the like, may be constructed of a member in which firmware and the like can be updated, or may be a program module or the like that is executed by a command from a CPU or the like, for example.

In a normal state, that is, in a state where automatic emergency deceleration action, which will be described below, is not taken, 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 depicted) of the master cylinder <NUM> is pressed to increase the hydraulic pressure of the brake fluid in the wheel cylinder <NUM>, the brake pad (not depicted) of the brake caliper <NUM> is then pressed against a rotor 3a of the front wheel <NUM>, and the braking force is thereby applied to the front wheel <NUM>. Meanwhile, when the second brake operation section <NUM> is operated, in the rear-wheel brake mechanism <NUM>, the piston (not depicted) of the master cylinder <NUM> is pressed to increase the hydraulic pressure of the brake fluid in the wheel cylinder <NUM>, the brake pad (not depicted) of the brake caliper <NUM> is then pressed against a rotor 4a of the rear wheel <NUM>, and the braking force is thereby applied to the rear wheel <NUM>.

As depicted in <FIG> and <FIG>, the brake system <NUM> includes master-cylinder pressure sensors <NUM>, wheel-cylinder pressure sensors <NUM>, a front-wheel rotational frequency sensor <NUM>, a rear-wheel rotational frequency sensor <NUM>, a lean angle sensor <NUM>, a peripheral environment sensor <NUM>, and a steering angle sensor <NUM>, for example. Each of the sensors is communicable with the controller <NUM>.

The master-cylinder pressure sensor <NUM> detects a 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 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 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 front-wheel rotational frequency sensor <NUM> and the rear-wheel rotational frequency sensor <NUM> are respectively provided on the front wheel <NUM> and the rear wheel <NUM>.

The lean angle sensor <NUM> detects a lean angle of the motorcycle <NUM> and an angular velocity of the lean angle thereof and outputs a detection result. 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 depicted in <FIG>. Note that a tilt of the motorcycle <NUM> in the rolling direction with respect to the upper vertical direction occurs during turning travel. More specifically, an inertial measurement unit (IMU) that includes a three-axis gyroscope sensor and a three-directional acceleration sensor is used as the lean angle sensor <NUM>. The lean angle sensor <NUM> may detect another physical quantity that can substantially be converted to the lean angle of the motorcycle <NUM> and the angular velocity of the lean angle thereof. The lean angle sensor <NUM> is provided in the trunk <NUM>.

The peripheral environment sensor <NUM> detects peripheral environment of the motorcycle <NUM>. For example, as the peripheral environment, the peripheral environment sensor <NUM> detects a distance from the motorcycle <NUM> to a forward obstacle (for example, a preceding vehicle). The peripheral environment sensor <NUM> may detect another physical quantity that can substantially be converted to the distance from the motorcycle <NUM> to the forward obstacle. More specifically, a camera that captures an image in front of the motorcycle <NUM> or a distance measurement sensor that can detect the distance from the motorcycle <NUM> to the forward obstacle is used as the peripheral environment sensor <NUM>. The peripheral environment sensor <NUM> is provided in a front portion of the trunk <NUM>.

In addition, the peripheral environment sensor <NUM> generates trigger information in accordance with the peripheral environment and outputs the trigger information. The trigger information is used to determine initiation of a control mode, which will be described below. For example, the peripheral environment sensor <NUM> computes a vehicle body speed of the motorcycle <NUM> on the basis of the rotational frequencies of the front wheel <NUM> and the rear wheel <NUM>, and predicts duration before arrival that is duration before the motorcycle <NUM> reaches the forward obstacle on the basis of the distance from the motorcycle <NUM> to the forward obstacle and the vehicle body speed. The peripheral environment sensor <NUM> generates the trigger information when the duration before the arrival is shorter than reference duration. The reference duration is set in accordance with estimated duration before the motorcycle <NUM> is stopped in the case where the motorcycle <NUM> takes the automatic emergency deceleration action.

Furthermore, the peripheral environment sensor <NUM> computes reference target deceleration in conjunction with generation of the trigger information and outputs a computation result. The reference target deceleration is a reference value of a target value of automatic emergency deceleration that is deceleration of the motorcycle <NUM> generated by the automatic emergency deceleration action. The reference target deceleration is deceleration that allows the motorcycle <NUM> to be stopped before the forward obstacle by the automatic emergency deceleration action, and is computed on the basis of the distance from the motorcycle <NUM> to the forward obstacle and the vehicle body speed, for example.

The steering angle sensor <NUM> detects a steering angle of the motorcycle <NUM> and an angular velocity of the steering angle thereof and outputs a detection result. The steering angle sensor <NUM> may detect another physical quantity that can substantially be converted to the steering angle of the motorcycle <NUM> and the angular velocity of the steering angle thereof. The steering angle sensor <NUM> is provided on the handlebar <NUM>.

The controller <NUM> controls behavior of the motorcycle <NUM>. The controller <NUM> includes an acquisition section <NUM> and an execution section <NUM>, for example. The acquisition section <NUM> acquires information output from each of the sensors and outputs the acquired information to the execution section <NUM>. The execution section <NUM> includes a control section <NUM>, a trigger determination section <NUM>, a change rate determination section <NUM>, and a lean angle determination section <NUM>, for example. Each of the determination sections executes determination processing by using the information that is output from each of the sensors. In accordance with a determination result by the trigger determination section <NUM>, the execution section <NUM> initiates the control mode that causes the motorcycle <NUM> to take the automatic emergency deceleration action. In the control mode, the control section <NUM> outputs a command that governs action of each of the inlet valves <NUM>, the outlet valves <NUM>, the pumps <NUM>, the first valves <NUM>, the second valves <NUM>, and the like in accordance with the determination result by each of the determination sections, so as to control the automatic emergency deceleration that is the deceleration of the motorcycle <NUM> generated by the automatic emergency deceleration action.

More specifically, in the control mode, the control section <NUM> controls the automatic emergency deceleration in accordance with a change rate of a state amount that is related to the posture of the motorcycle <NUM> during the turning travel. Alternatively, in the control mode, the control section <NUM> may control the automatic emergency deceleration in accordance with the lean angle of the motorcycle <NUM>. Note that the control of the automatic emergency deceleration includes control to permit or prohibit the automatic emergency deceleration action in addition to the control of the automatic emergency deceleration of the motorcycle <NUM> that is generated during the automatic emergency deceleration action.

The controller <NUM> includes a storage element, and the information such as the reference values that is used in each of the processing executed by the controller <NUM> may be stored in the storage element in advance.

A description will be made on action of the brake system <NUM> according to the embodiment of the invention. <FIG> is a flowchart of one example of processing that is executed by the controller <NUM> according to the embodiment of the invention. A control flow depicted in <FIG> is repeated during activation of the brake system <NUM> (in other words, during an operation of the motorcycle <NUM>). Step S110 and step S190 in <FIG> respectively correspond to initiation and termination of the control flow. Note that, in step S110, the control flow is initiated in a state where the control mode is not initiated.

In step S111, the acquisition section <NUM> acquires the trigger information. Note that the case where the peripheral environment sensor <NUM> generates the trigger information has been described above; however, the controller <NUM> may generate the trigger information. For example, the detection result of the distance from the motorcycle <NUM> to the forward obstacle may be output from the peripheral environment sensor <NUM> to the controller <NUM>, and the controller <NUM> may generate the trigger information on the basis of the distance from the motorcycle <NUM> to the forward obstacle and the vehicle body speed of the motorcycle <NUM>. In this way, the acquisition section <NUM> can acquire the trigger information.

Next, in step S113, the trigger determination section <NUM> determines whether the trigger information has been acquired. If it is determined that the trigger information has been acquired (step S113/Yes), the processing proceeds to step S115. On the other hand, if it is determined that the trigger information has not been acquired (step S113/No), the processing returns to step S111.

In step S115, the execution section <NUM> initiates the control mode that causes the motorcycle <NUM> to take the automatic emergency deceleration action.

Next, in step S117, the acquisition section <NUM> acquires the change rate of the state amount that is related to the posture of the motorcycle <NUM> during the turning travel. The state amount that is related to the posture of the motorcycle <NUM> during the turning travel includes the lean angle, the angular velocity of the lean angle, the steering angle, or the angular velocity of the steering angle, for example.

Next, in step S119, the change rate determination section <NUM> determines whether the change rate of the state amount that is related to the posture of the motorcycle <NUM> during the turning travel exceeds a change rate reference value. If it is determined that the change rate exceeds the change rate reference value (step S119/Yes), the processing proceeds to step S127. On the other hand, if it is determined that the change rate does not exceed the change rate reference value (step S119/No), the processing proceeds to step S121. The change rate reference value is set to such a value that a determination on whether the driver has his/her intention to avoid the forward obstacle can be made.

In step S121, the acquisition section <NUM> acquires the lean angle of the motorcycle <NUM>.

Next, in step S123, the lean angle determination section <NUM> determines whether the lean angle of the motorcycle <NUM> exceeds a lean angle reference value. If it is determined that the lean angle exceeds the lean angle reference value (step S123/Yes), the processing proceeds to step S127. On the other hand, if it is determined that the lean angle does not exceed the lean angle reference value (step S123/No), the processing proceeds to step S125. The lean angle reference value is such a value that a determination on whether a possibility of falling of the motorcycle <NUM>, which is resulted from the generation of the deceleration of the motorcycle <NUM>, is excessively high can be made, and is set in accordance with a friction coefficient of a travel road surface, a design specification of the motorcycle <NUM>, and the like, for example.

In step S125, the control section <NUM> permits the automatic emergency deceleration action. Once permitting the automatic emergency deceleration action, the control section <NUM> causes the generation of the automatic emergency deceleration that is the deceleration independent of the driver's operation, and causes the motorcycle <NUM> to take the automatic emergency deceleration action. For example, the control section <NUM> causes the generation of the automatic emergency deceleration through generation of the braking force that is applied to the wheel by at least one of the front-wheel brake mechanism <NUM> and the rear-wheel brake mechanism <NUM>. More specifically, the control section <NUM> drives the pump <NUM> in a state where the inlet valve <NUM> is opened, the outlet valve <NUM> is closed, the first valve <NUM> is closed, and the second valve <NUM> is opened, so as to cause the generation of the braking force that is applied to the wheel.

The control section <NUM> controls the braking force that is applied to the wheel by controlling a rotational frequency of the pump <NUM>. More specifically, the control section <NUM> decides target deceleration on the basis of the reference target deceleration that is output from the peripheral environment sensor <NUM>. For example, the control section <NUM> decides a value that is obtained by multiplying the reference target deceleration by a coefficient as the target deceleration. Then, based on the target deceleration, the control section <NUM> decides a target hydraulic pressure that is a target value of the hydraulic pressure of the brake fluid in the wheel cylinder <NUM>. Thereafter, the control section <NUM> controls the rotational frequency of the pump <NUM> such that the hydraulic pressure of the brake fluid in the wheel cylinder <NUM> matches the target hydraulic pressure. In this way, the automatic emergency deceleration is controlled to match the target deceleration.

For example, in the case where the lean angle is large, the control section <NUM> causes the motorcycle <NUM> to take the automatic emergency deceleration action in which the automatic emergency deceleration is lower than the automatic emergency deceleration in the automatic emergency deceleration action that is taken when the lean angle is small. More specifically, the control section <NUM> decides the value that is obtained by multiplying the reference target deceleration by the coefficient as the target deceleration, and the coefficient becomes smaller as the lean angle is increased. In this way, the control section <NUM> controls the automatic emergency deceleration.

Alternatively, for example, in the case where the change rate of the state amount that is related to the posture of the motorcycle <NUM> during the turning travel is high, the control section <NUM> causes the motorcycle <NUM> to take the automatic emergency deceleration action in which the automatic emergency deceleration is lower than the automatic emergency deceleration in the automatic emergency deceleration action that is taken when the change rate is low. More specifically, the control section <NUM> decides a value that is obtained by multiplying the reference target deceleration by the coefficient as the target deceleration, and the coefficient becomes smaller as the change rate of the state amount that is related to the posture of the motorcycle <NUM> during the turning travel is increased. In this way, the control section <NUM> controls the automatic emergency deceleration.

The control section <NUM> may decide the target deceleration in accordance with both of the lean angle and the change rate of the state amount that is related to the posture of the motorcycle <NUM> during the turning travel. In such a case, the control section <NUM> decides a value that is obtained by multiplying the reference target deceleration by both of the coefficient corresponding to the lean angle and the coefficient corresponding to the change rate of the state amount as the target deceleration, for example.

Note that the case where the control section <NUM> controls the automatic emergency deceleration by controlling the braking force that is applied to the wheel has been described above; however, the control section <NUM> may control the automatic emergency deceleration by controlling engine output of the motorcycle <NUM>. More specifically, the control section <NUM> may control the automatic emergency deceleration by using an operational effect of engine brake that is exerted when the engine output is lowered. Alternatively, the control section <NUM> may control the automatic emergency deceleration by controlling both of the braking force that is applied to the wheel and the engine output.

In step S127, the control section <NUM> prohibits the automatic emergency deceleration action. When the automatic emergency deceleration action is prohibited, the control section <NUM> brings the motorcycle <NUM> into the normal state where the deceleration is generated in accordance with the driver's operation. More specifically, the control section <NUM> 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 opened, and the second valves <NUM> are closed, so as to prohibit driving of the pumps <NUM>.

Following step S125 or step S127, in step S129, the acquisition section <NUM> acquires the trigger information.

Next, in step S131, the trigger determination section <NUM> determines whether the trigger information has been acquired. If it is determined that the trigger information has been acquired (step S131/Yes), the processing returns to step S117. On the other hand, if it is determined that the trigger information has not been acquired (step S131/No), the processing proceeds to step S133.

As described above, if it is determined in step S131 that the trigger information has been acquired (step S131/Yes), the control mode continues, and the processing from step S117 to step S129 is repeated. In the case where the control mode continues, the control section <NUM> appropriately switches between a state where the automatic emergency deceleration action is permitted and a state where the automatic emergency deceleration action is prohibited in accordance with the determination results of the determination processing by the change rate determination section <NUM> or the lean angle determination section <NUM> (step S119 and step S123).

In the case where both of the determination results in step S119 and step S123 are No in the state where the automatic emergency deceleration action is permitted, the control section <NUM> continues the state where the automatic emergency deceleration action is permitted. In this case, for example, the control section <NUM> controls the automatic emergency deceleration of the motorcycle <NUM>, which is generated during the automatic emergency deceleration action, in accordance with the lean angle acquired during the automatic emergency deceleration action. In addition, for example, the control section <NUM> controls the automatic emergency deceleration of the motorcycle <NUM> generated during the automatic emergency deceleration action in accordance with the change rate of the state amount that is related to the posture of the motorcycle <NUM> during the turning travel and that is acquired during the automatic emergency deceleration action.

In the case where at least one of the determination results in step S119 and step S123 is Yes in the state where the automatic emergency deceleration action is permitted, the control section <NUM> cancels the state where the automatic emergency deceleration action is permitted, and prohibits the automatic emergency deceleration action. For example, in the case where the change rate of the state amount that is related to the posture of the motorcycle <NUM> during the turning travel and that is acquired during the automatic emergency deceleration action exceeds the change rate reference value, the control section <NUM> cancels the state where the automatic emergency deceleration action is permitted, and prohibits the automatic emergency deceleration action. Alternatively, for example, in the case where the lean angle that is acquired during the automatic emergency deceleration action exceeds the lean angle reference value, the control section <NUM> cancels the state where the automatic emergency deceleration action is permitted, and prohibits the automatic emergency deceleration action.

In the case where at least one of the determination results in step S119 and step S123 is Yes in the state where the automatic emergency deceleration action is prohibited, the control section <NUM> continues the state where the automatic emergency deceleration action is prohibited.

In the case where both of the determination results in step S119 and step S123 are No in the state where the automatic emergency deceleration action is prohibited, the control section <NUM> cancels the state where the automatic emergency deceleration action is prohibited, and permits the automatic emergency deceleration action. For example, in the cases where the determination result in step S119 is No and the lean angle that is acquired during the prohibition of the automatic emergency deceleration action falls below the lean angle reference value, the control section <NUM> cancels the state where the automatic emergency deceleration action is prohibited, and permits the automatic emergency deceleration action. Note that the determination processing in step S119 may be removed from the control flow depicted in <FIG>. In such a case, in the case where the lean angle that is acquired during the prohibition of the automatic emergency deceleration action falls below the lean angle reference value, the control section <NUM> cancels the state where the automatic emergency deceleration action is prohibited, and permits the automatic emergency deceleration action.

In step S133, the execution section <NUM> terminates the control mode.

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

In the brake system <NUM>, the control mode that causes the motorcycle <NUM> to take the automatic emergency deceleration action is initiated in response to the trigger information that is generated in accordance with the peripheral environment of the motorcycle <NUM>. In the control mode, the automatic emergency deceleration is controlled in accordance with the change rate of the state amount that is related to the posture of the motorcycle <NUM> during the turning travel. In this way, the automatic emergency deceleration can appropriately be controlled in accordance with the posture of the motorcycle <NUM>. Therefore, the safety can be improved by the automatic emergency deceleration action while the motorcycle <NUM> is suppressed from falling over.

Preferably, in the control mode, the brake system <NUM> prohibits the automatic emergency deceleration action in the case where the change rate of the state amount that is related to the posture of the motorcycle <NUM> during the turning travel exceeds the change rate reference value. In this way, in the case where it is predicted that the driver has his/her intention to avoid the forward obstacle, the automatic emergency deceleration action can be prohibited. Thus, the generation of the automatic emergency deceleration against the driver's intention can be suppressed. Therefore, the motorcycle <NUM> can effectively be suppressed from falling over.

Note that, in the control mode, the control section <NUM> may prohibit the automatic emergency deceleration action in the case where an operation amount that is related to the driver's operation of the motorcycle <NUM> exceeds an operation amount reference value. The driver's operation of the motorcycle <NUM> includes an accelerator pedal operation, a brake operation, and a clutch operation, for example. The operation amount reference value is set to such a value that a determination on whether the driver has operated the motorcycle <NUM> can be made. Accordingly, in the case where the operation amount exceeds the operation amount reference value, the automatic emergency deceleration action is prohibited. In this way, the generation of the automatic emergency deceleration against the driver's operation of the motorcycle <NUM> can be suppressed. Therefore, the motorcycle <NUM> can effectively be suppressed from falling over.

In addition, in the control mode, in the case where the change rate of the state amount that is related to the posture of the motorcycle <NUM> during the turning travel exceeds the change rate reference value, the control section <NUM> may reduce the operation amount reference value in comparison with the case where the change rate does not exceed the change rate reference value. In this way, in the case where it is predicted that the driver has his/her intention to avoid the forward obstacle, sensitivity to detection of the driver's operation of the motorcycle <NUM> can be improved. Therefore, the automatic emergency deceleration action can further reliably be prohibited.

Preferably, in the control mode, in the case where the change rate of the state amount that is related to the posture of the motorcycle <NUM> during the turning travel is high, the automatic emergency deceleration action is taken in the brake system <NUM>, and the automatic emergency deceleration therein is lower than the automatic emergency deceleration in the automatic emergency deceleration action that is taken when the change rate is low. Here, it is predicted that the possibility that the driver has his/her intention to avoid the forward obstacle is increased as the change rate of the state amount is increased. Accordingly, in the case where the change rate of the state amount is high, the automatic emergency deceleration action is taken, and the automatic emergency deceleration therein is lower than the automatic emergency deceleration in the automatic emergency deceleration action that is taken when the change rate is low. In this way, the automatic emergency deceleration can appropriately be controlled in accordance with the possibility that the driver has his/her intention to avoid the forward obstacle. Therefore, falling of the motorcycle <NUM>, which is resulted from the generation of the automatic emergency deceleration against the driver's intention, can be suppressed.

Preferably, in the control mode, the automatic emergency deceleration of the motorcycle <NUM> generated during the automatic emergency deceleration action is controlled in the brake system <NUM> in accordance with the change rate of the state amount that is related to the posture of the motorcycle <NUM> during the turning travel and that is acquired during the automatic emergency deceleration action. In this way, the automatic emergency deceleration of the motorcycle <NUM>, which is during the automatic emergency deceleration action, can appropriately be controlled in accordance with the change of the change rate of the state amount over time during the automatic emergency deceleration action. Therefore, falling of the motorcycle <NUM>, which is resulted from the generation of the automatic emergency deceleration against the driver's intention, can effectively be suppressed.

Preferably, the state amount that is related to the posture of the motorcycle <NUM> during the turning travel and that is used for the control of the automatic emergency deceleration includes the lean angle of the motorcycle <NUM> or the angular velocity of the lean angle thereof. In this way, the automatic emergency deceleration can be controlled by using the detection result that is output from the lean angle sensor <NUM>. Thus, another sensor (for example, the steering angle sensor <NUM>) can be removed from the configuration of the brake system <NUM>. Therefore, the brake system <NUM> can be simplified.

Preferably, in the control mode, the brake system <NUM> controls the automatic emergency deceleration in accordance with the lean angle of the motorcycle <NUM> during the turning travel. In this way, the automatic emergency deceleration can further appropriately be controlled in accordance with the posture of the motorcycle <NUM>. Therefore, the effect of improving the safety by the automatic emergency deceleration action can further be enhanced while the motorcycle <NUM> is suppressed from falling over.

Preferably, in the control mode, in the case where the lean angle is large, the automatic emergency deceleration action is taken in the brake system <NUM>, and the automatic emergency deceleration therein is lower than the automatic emergency deceleration in the automatic emergency deceleration action that is taken when the lean angle is small. Here, grounding areas of tires of the motorcycle <NUM> are reduced as the lean angle is increased. In addition, a friction characteristic in a grounding portion of each of the tires of the motorcycle <NUM> possibly has such a characteristic that a friction force is less likely to be generated in an advancing direction as the lean angle is increased. Accordingly, the possibility of falling of the motorcycle <NUM>, which is resulted from the generation of the deceleration of the motorcycle <NUM>, tends to be increased as the lean angle is increased. Thus, in the case where the lean angle is large, the automatic emergency deceleration action is taken, and the automatic emergency deceleration therein is lower than the automatic emergency deceleration in the automatic emergency deceleration action that is taken when the lean angle is small. In this way, the motorcycle <NUM> can effectively be suppressed from falling over.

Preferably, in the control mode, the brake system <NUM> controls the automatic emergency deceleration of the motorcycle <NUM>, which is generated during the automatic emergency deceleration action, in accordance with the lean angle acquired during the automatic emergency deceleration action. In this way, the automatic emergency deceleration of the motorcycle <NUM>, which is generated during the automatic emergency deceleration action, can appropriately be controlled in accordance with a change in the lean angle over time during the automatic emergency deceleration action. For example, the automatic emergency deceleration can be increased along with a decrease in the lean angle that is resulted from the automatic emergency deceleration action. As a result, an increase in a braking distance can be suppressed while the motorcycle <NUM> is suppressed from falling over. Therefore, the effect of increasing the safety can be enhanced by the automatic emergency deceleration action.

Preferably, in the control mode, the brake system <NUM> prohibits the automatic emergency deceleration action in the case where the lean angle exceeds the lean angle reference value. In this way, in the case where the possibility of falling of the motorcycle <NUM>, which is resulted from the generation of the deceleration of the motorcycle <NUM>, is excessively high, the automatic emergency deceleration action can be prohibited. Therefore, the motorcycle <NUM> can effectively be suppressed from falling over.

Claim 1:
A controller (<NUM>) that is configured to control behavior of a motorcycle (<NUM>), the controller comprising:
an acquisition section (<NUM>) that is configured to acquire trigger information generated in accordance with peripheral environment of the motorcycle (<NUM>); and
an execution section (<NUM>) that is configured to initiate a control mode in response to the trigger information, the control mode causing the motorcycle (<NUM>) to take automatic emergency deceleration action, wherein
the acquisition section (<NUM>) is configured to acquire a change rate of a state amount that is related to the posture of the motorcycle (<NUM>) during the turning travel, and
the execution section (<NUM>) includes a control section (<NUM>),
in the control mode, the control section (<NUM>) controls the automatic emergency deceleration that is deceleration of the motorcycle (<NUM>) generated by the automatic emergency deceleration action in accordance with the change rate,
wherein in the control mode, in the case where the change rate exceeds a change rate reference value, the automatic emergency deceleration action is prohibited, and
in the case where the control mode continues, the control section (<NUM>) switches between a state where the automatic emergency deceleration action is permitted and a state where the automatic emergency deceleration action is prohibited in accordance with the change rate.