Patent Description:
Conventionally, straddled vehicles that include, as a suspension, such as a front fork, a rear suspension, or the like, an electronically controlled suspension capable of adjusting a damping force and a spring reaction force by electronic control have been known. Also, straddled vehicles that include a radar device that detects front of a vehicle have been known. For example, <CIT> describes a straddled vehicle including an electronically controlled suspension and a radar device.

<CIT> describes control in which, when a brake is automatically actuated in order to avoid a collision with an obstacle in front of a vehicle, a spring reaction force of a front fork, a damping force of the front fork in a contraction direction, and a damping force of a rear suspension in an expansion direction are increased and a spring reaction force of the rear suspension is reduced. According to the control, before the brake is actuated, an operation of the front fork in the contraction direction becomes stiff and an operation of the rear suspension in the expansion direction becomes stiff. Therefore, when the brake is actuated, a vehicle body can be suppressed from becoming a front-down posture and pitching of the motorcycle is reduced.

Straddled vehicles that can execute cruise control have been known. For example, straddled vehicles that perform control in which following a preceding vehicle is caused while keeping a predetermined inter-vehicle distance from the preceding vehicle on a highway or the like have been known. Also, straddled vehicles that perform control in which traveling at a set constant speed is caused have been known. When executing the above-described controls, a straddled vehicle accelerates or decelerates as appropriate. At this time, pitching occurs and riding comfort is reduced in some cases.

In view of the foregoing, the present invention has been devised and it is therefore an object of the present invention to increase riding comfort of a straddled vehicle during cruise control. <CIT> discloses a straddled vehicle according to the preamble of claim <NUM>.

A straddled vehicle according to the invention includes a vehicle body frame, a front wheel supported by the vehicle body frame, a rear wheel supported by the vehicle body frame, a front wheel brake that brakes the front wheel, a rear wheel brake that brakes the rear wheel, a drive source that is supported by the vehicle body frame and drives the rear wheel, an electronically controlled front suspension connected to the vehicle body frame and the front wheel, an electronically controlled rear suspension connected to the vehicle body frame and the rear wheel and a control device connected to the front wheel brake, the rear wheel brake, the drive source, the front suspension, and the rear suspension. The control device includes a traveling controller and a suspension controller. The traveling controller is configured to execute cruise control by controlling at least one of the front wheel brake, the rear wheel brake, and the drive source. The suspension controller is configured to, when the traveling controller accelerates or decelerates the straddled vehicle during the cruise control, control at least one of a damping force of the front suspension, a spring reaction force of the front suspension, a damping force of the rear suspension, and a spring reaction force of the rear suspension.

The straddled vehicle may further include a preceding vehicle detection device that is supported by the vehicle body frame and detects an inter-vehicle distance from a preceding vehicle. The control device may be connected to the preceding vehicle detection device. The traveling controller may be configured to execute cruise control in which the straddled vehicle is caused to follow the preceding vehicle while keeping a set inter-vehicle distance from the preceding vehicle by controlling at least one of the front wheel brake, the rear wheel brake, and the drive source, based on a detection value of the preceding vehicle detection device.

According to the straddled vehicle, during cruise control, at least one of the damping force of the front suspension, the spring reaction force of the front suspension, the damping force of the rear suspension, and the spring reaction force of the rear suspension is controlled in accordance with acceleration or deceleration of the straddled vehicle. Therefore, pitching during the cruise control can be suppressed. Accordingly, riding comfort can be increased.

According to the invention, the suspension controller is configured to, when the traveling controller accelerates the straddled vehicle during the cruise control, increase a damping force of the front suspension in an expansion direction and/or a damping force of the rear suspension in a contraction direction.

Thus, when the straddled vehicle accelerates during cruise control, an expansion operation of the front suspension and/or a contraction operation of the rear suspension becomes stiff. Therefore, a vehicle body can be suppressed from becoming a front-up posture at acceleration during the cruise control. Accordingly, riding comfort can be increased.

The suspension controller may be configured to, when the traveling controller accelerates the straddled vehicle during the cruise control, cause the damping force of the front suspension in the expansion direction and/or the damping force of the rear suspension in the contraction direction to increase as an acceleration of the straddled vehicle increases.

Thus, as degree of acceleration increases, a force that suppresses the vehicle body from becoming the front-up posture increases. Accordingly, the vehicle body can be preferably suppressed from becoming the front-up posture at acceleration during cruise control and riding comfort can be increased.

The traveling controller may be configured to calculate a target acceleration of the straddled vehicle, based on the inter-vehicle distance detected by the preceding vehicle detection device and, when the acceleration of the straddled vehicle is lower than the target acceleration, increase an output of the drive source. The suspension controller may be configured to increase the damping force of the front suspension in the expansion direction and/or the damping force of the rear suspension in the contraction direction in accordance with the target acceleration before the output of the drive source is increased.

Thus, when the straddled vehicle accelerates, the damping force of the front suspension in the expansion direction and/or the damping force of the rear suspension in the contraction direction increases prior to increase of the output of the drive source. Therefore, when the straddled vehicle accelerates, the vehicle body can be more effectively suppressed from becoming the front-up posture.

The control device may include a storage that stores a map defining a relationship between the target acceleration and the damping force of the front suspension in the expansion direction and/or the damping force of the rear suspension in the contraction direction. The suspension controller may be configured to increase the damping force of the front suspension in the expansion direction and/or the damping force of the rear suspension in the contraction direction, based on the map.

Thus, in increasing the damping force of the front suspension in the expansion direction and/or the damping force of the rear suspension in the contraction direction in accordance with the target acceleration, a load of and a time required for a calculation of the control device can be reduced. When the straddled vehicle accelerates, the damping force of the front suspension in the expansion direction and/or the damping force of the rear suspension in the contraction direction can be controlled in a short time.

According to the invention, the straddled vehicle further includes an accelerator operator that is supported by the vehicle body frame and is operated by a rider. The control device includes a suspension control prohibitor that prohibits control of the suspension controller when the accelerator operator is operated.

Thus, when the rider operates the accelerator operator, control of the suspension controller is prohibited. Control of the suspension controller can be disabled by an intension of the rider.

The suspension controller may be configured to, when the traveling controller accelerates the straddled vehicle during the cruise control, reduce the spring reaction force of the front suspension and/or increase the spring reaction force of the rear suspension.

Thus, when the straddled vehicle accelerates during cruise control, the expansion operation of the front suspension and/or the contraction operation of the rear suspension becomes stiff. Therefore, the vehicle body can be suppressed from becoming the front-up posture at acceleration during the cruise control. Accordingly, riding comfort can be increased.

The suspension controller may be configured to, when the traveling controller decelerates the straddled vehicle during the cruise control, increase the damping force of the front suspension in the contraction direction and/or the damping force of the rear suspension in the expansion direction.

Thus, when the straddled vehicle decelerates during cruise control, a contraction operation of the front suspension and/or an expansion operation of the rear suspension becomes stiff. Therefore, the vehicle body is suppressed from becoming the front-down posture at deceleration during cruise control. Accordingly, riding comfort can be increased.

The suspension controller may be configured to, when the traveling controller decelerates the straddled vehicle during the cruise control, cause the damping force of the front suspension in the contraction direction and/or the damping force of the rear suspension in the expansion direction to increase as a deceleration of the straddled vehicle increases.

Thus, as degree of deceleration increases, a force that suppresses the vehicle body from becoming the front-down posture increases. Accordingly, the vehicle body can be preferably suppressed from becoming the front-down posture at deceleration during cruise control and riding comfort can be increased.

The traveling controller may be configured to calculate a target deceleration of the straddled vehicle, based on the inter-vehicle distance detected by the preceding vehicle detection device and, when a deceleration of the straddled vehicle is lower than the target deceleration, execute a deceleration operation including at least one of increasing the braking force of the front wheel brake and/or the rear wheel brake and reducing the output of the drive source. The suspension controller may be configured to increase the damping force of the front suspension in the contraction direction and/or the damping force of the rear suspension in the expansion direction in accordance with the target deceleration before the deceleration operation is started.

Thus, prior to actuation of the front wheel brake and/or the rear wheel brake and/or reduction of the output of the drive source, the damping force of the front suspension in the contraction direction and/or the damping force of the rear suspension in the expansion direction are increased. Therefore, when the straddled vehicle decelerates, the vehicle body can be more effectively suppressed from becoming the front-down posture.

The control device may include a storage that stores a map defining a relationship between the target deceleration and the damping force of the front suspension in the contraction direction and/or the damping force of the rear suspension in the expansion direction. The suspension controller may be configured to increase the damping force of the front suspension in the contraction direction and/or the damping force of the rear suspension in the expansion direction, based on the map.

Thus, in increasing the damping force of the front suspension in the contraction direction and/or the damping force of the rear suspension in the expansion direction in accordance with the target deceleration, a load of and a time required for a calculation of the control device can be reduced. When the straddled vehicle decelerates, the damping force of the front suspension in the contraction direction and/or the damping force of the rear suspension in the expansion direction can be controlled in a short time.

The suspension controller may be configured to, when the traveling controller decelerates the straddled vehicle during the cruise control, increase the spring reaction force of the front suspension and/or reduce the spring reaction force of the rear suspension.

According to the present invention, riding comfort of a straddled vehicle during cruise control can be increased.

With reference to the attached drawings, one embodiment of a straddled vehicle will be described below. As illustrated in <FIG>, a straddled vehicle according to this embodiment is a motorcycle <NUM>.

As illustrated in <FIG>, the motorcycle <NUM> includes a vehicle body frame <NUM>, a seat <NUM> supported by the vehicle body frame <NUM>, an internal combustion engine (which will be hereinafter referred to as an engine) <NUM> supported by the vehicle body frame <NUM>, a front wheel <NUM> and a rear wheel <NUM> supported by the vehicle body frame <NUM>, an electronically controlled front fork <NUM> connected to the vehicle body frame <NUM> and the front wheel <NUM>, an electronically controlled rear suspension <NUM> connected to the vehicle body frame <NUM> and the rear wheel <NUM>, and a radar <NUM>. As illustrated in <FIG>, the motorcycle <NUM> includes an accelerator grip 16A that is an example of an accelerator operator, a vehicle speed sensor <NUM> that detects a speed of the motorcycle <NUM>, an acceleration sensor <NUM> that detects an acceleration of the motorcycle <NUM>, a front wheel brake 8B that brakes the front wheel <NUM>, a rear wheel brake 9B that brakes the rear wheel <NUM>, and a control device <NUM>. The control device <NUM> is communicably connected to the accelerator grip 16A, the radar <NUM>, the vehicle speed sensor <NUM>, the acceleration sensor <NUM>, the engine <NUM>, the front wheel brake 8B, the rear wheel brake 9B, the front fork <NUM>, and the rear suspension <NUM>.

As illustrated in <FIG>, the vehicle body frame <NUM> includes a head pipe <NUM>, a main frame <NUM> extending rearward from the head pipe <NUM>, and a seat frame <NUM> extending rearward from the main frame <NUM>. The seat <NUM> is supported by the seat frame <NUM>.

A steering shaft <NUM> is rotatably inserted in the head pipe <NUM>. A handlebar <NUM> is mounted on an upper end portion of the steering shaft <NUM>. Although not illustrated in <FIG>, the accelerator grip 16A is rotatably mounted to a right end portion of the handlebar <NUM>. An upper bracket <NUM> is fixed to the upper end portion of the steering shaft <NUM>. An under bracket <NUM> is fixed to a lower end portion of the steering shaft <NUM>.

The engine <NUM> is supported by the vehicle body frame <NUM>. The engine <NUM> is an example of a drive source that drives the rear wheel <NUM>. However, the drive source for traveling is not limited to the engine <NUM>. The drive device may include an electric motor. The drive source may include both of an internal combustion engine and an electric motor.

The front wheel <NUM> is supported by the head pipe <NUM> of the vehicle body frame <NUM> via the front fork <NUM>. The rear wheel <NUM> is supported by the main frame <NUM> of the vehicle body frame <NUM> via a rear arm <NUM>. A front end portion of the rear arm <NUM> is rotatably connected to the main frame <NUM> via an unillustrated pivot shaft. A rear end portion of the rear arm <NUM> is connected to the rear wheel <NUM>. The rear wheel <NUM> is connected to the engine <NUM> via a power transmission member (not illustrated), such as a chain of the like. The rear wheel <NUM> is a drive wheel and receives a driving force of the engine <NUM> to rotate.

The front fork <NUM> is an example of an electronic controlled suspension. Note that the electronic controlled suspension is a suspension in which at least a damping force characteristic is adjusted by electronic control. Herein, the front fork <NUM> is configured such that both a damping force characteristic and a spring characteristic are adjustable by electronic control. As illustrated in <FIG>, the front fork <NUM> is fixed to the upper bracket <NUM> and the under bracket <NUM>. The front fork <NUM> includes a left tube <NUM> and a right tube 20R.

Each of the left tube <NUM> and the right tube 20R includes an outer tube <NUM> and an inner tube <NUM>. The outer tube <NUM> is mounted to the upper bracket <NUM> and the under bracket <NUM>. A lower end portion of the inner tube <NUM> is joined to an axle 8A of the front wheel <NUM> via an axle bracket <NUM>. The inner tube <NUM> is slidably inserted inside the outer tube <NUM>. The inner tube <NUM> slides against the outer tube <NUM>, so that the front fork <NUM> expands and contracts. In this embodiment, when the inner tube <NUM> moves downward with respect to the outer tube <NUM>, the front fork <NUM> expands. When the inner tube <NUM> moves upward with respect to the outer tube <NUM>, the front fork <NUM> contracts. Downward and upward correspond to an expansion direction and a contraction direction of the front fork <NUM>, respectively.

Although not illustrated, a fork spring is arranged inside each of the right tube 20R and the left tube <NUM>. The fork spring is an example of a spring of the front fork <NUM>.

The right tube 20R includes an oil-type shock absorber <NUM> that is electronically controlled. The shock absorber <NUM> includes the inner tube <NUM>, a rod <NUM>, a piston <NUM>, and a control valve assembly <NUM>. The rod <NUM> is undisplaceably fixed to the outer tube <NUM>. The piston <NUM> is connected to a lower end portion of the rod <NUM>. The piston <NUM> is arranged inside the inner tube <NUM>. An inner space of the inner tube <NUM> is partitioned into an oil chamber <NUM> and an oil chamber <NUM> by the piston <NUM>.

The control valve assembly <NUM> is connected to the oil chamber <NUM> and the oil chamber <NUM>. The control valve assembly <NUM> includes oil paths <NUM> to <NUM>, check valves <NUM> and <NUM>, and electronically controlled piston valves <NUM> and <NUM>. The check valve <NUM> is arranged between the oil path <NUM> and the oil path <NUM>. The check valve <NUM> allows a flow of oil from the oil path <NUM> to the oil path <NUM> and prohibits a flow of oil from the oil path <NUM> to the oil path <NUM>. The check valve <NUM> is arranged between the oil path <NUM> and the oil path <NUM>. The check valve <NUM> allows a flow of oil from the oil path <NUM> to the oil path <NUM> and prohibits a flow of oil from the oil path <NUM> to the oil path <NUM>. The piston valve <NUM> connects the oil path <NUM> and the oil path <NUM>. The piston valve <NUM> allows a flow of oil from the oil path <NUM> to the oil path <NUM> and prohibits a flow of oil from the oil path <NUM> to the oil path <NUM>. The piston valve <NUM> connects the oil path <NUM> and the oil path <NUM>. The piston valve <NUM> allows a flow of oil from the oil path <NUM> to the oil path <NUM> and prohibits a flow of oil from the oil path <NUM> to the oil path <NUM>. Each of the piston valves <NUM> and <NUM> is constituted of, for example, a solenoid valve.

When oil flows through the piston valve <NUM>, the oil receives a flow resistance. Degree of the flow resistance caused by the piston valve <NUM> is controlled by the control device <NUM> (specifically, a control unit 60B that will be described later). When the control device <NUM> increases the flow resistance of the piston valve <NUM>, the oil receives more resistance as the oil flows from the oil path <NUM> to the oil path <NUM>. Thus, the oil is difficult to flow from the oil chamber <NUM> to the oil chamber <NUM> through the control valve assembly <NUM>, so that a damping force of the front fork <NUM> in the expansion direction is increased. Conversely, when the control device <NUM> reduces the flow resistance of the piston valve <NUM>, the damping force of the front fork <NUM> in the expansion direction is reduced.

When the oil flows through the piston valve <NUM>, the oil receives a flow resistance. Degree of the flow resistance caused by the piston valve <NUM> is controlled by the control device <NUM>. When the control device <NUM> increases the flow resistance of the piston valve <NUM>, the oil receives more resistance as the oil flows from the oil path <NUM> to the oil path <NUM>. Thus, the oil is difficult to flow from the oil chamber <NUM> to the oil chamber <NUM> through the control valve assembly <NUM>, so that a damping force of the front fork <NUM> in the contraction direction is increased. Conversely, when the control device <NUM> reduces the flow resistance of the piston valve <NUM>, the damping force of the front fork <NUM> in the contraction direction is reduced.

As illustrated in <FIG>, an upper end portion <NUM> of the rear suspension <NUM> is fixed to the main frame <NUM> via a bracket. A lower end portion <NUM> of the rear suspension <NUM> is connected to a joining member <NUM> fixed to the rear arm <NUM>. The rear suspension <NUM> is indirectly connected to the vehicle body frame <NUM> and the rear wheel <NUM>.

The rear suspension <NUM> is another example of the electronically controlled suspension. Herein, the rear suspension <NUM> is configured such that a damping force characteristic and a spring characteristic can be adjusted by electronic control. The rear suspension <NUM> includes an unillustrated spring. Moreover, as illustrated in <FIG>, the rear suspension <NUM> includes an oil-type shock absorber 40B that is electronically controlled. The shock absorber 40B includes a cylinder <NUM>, a piston <NUM> slidably arranged inside the cylinder <NUM>, and a rod <NUM> extending from the piston <NUM>. An internal space of the cylinder <NUM> is partitioned into an oil chamber <NUM> and an oil chamber <NUM> by the piston <NUM>. When the piston <NUM> moves downward, the rear suspension <NUM> expands. When the piston <NUM> moves upward, the rear suspension <NUM> contracts. Downward and upward correspond to an expansion direction and a contraction direction of the rear suspension <NUM>, respectively.

The rear suspension <NUM> includes a control valve assembly <NUM> that is similar to the control valve assembly <NUM> of the front fork <NUM>. Each member that is similar to a corresponding member of the control valve assembly <NUM> of the front fork <NUM> will be denoted below by the same reference character as that of the corresponding member of the control valve assembly <NUM> and description thereof will be omitted. In the rear suspension <NUM>, the oil path <NUM> of the control valve assembly <NUM> is connected to the oil chamber <NUM>. The oil path <NUM> of the control valve assembly <NUM> is connected to the oil chamber <NUM>.

When the control device <NUM> (specifically, the control unit 60B that will be described later) increases the flow resistance of the piston valve <NUM>, the oil is difficult to flow from the oil chamber <NUM> to the oil chamber <NUM> through the control valve assembly <NUM>, so that a damping force of the rear suspension <NUM> in the contraction direction is increased. Conversely, when the control device <NUM> reduces the flow resistance of the piston valve <NUM>, the damping force of the rear suspension <NUM> in the contraction direction is reduced.

When the control device <NUM> increases the flow resistance of the piston valve <NUM>, the oil is difficult to flow from the oil chamber <NUM> to the oil chamber <NUM> through the control valve assembly <NUM>, so that a damping force of the rear suspension <NUM> in the expansion direction is increased. Conversely, when the control device <NUM> reduces the flow resistance of the piston valve <NUM>, the damping force of the rear suspension <NUM> in the expansion direction is reduced.

The radar <NUM> (see <FIG>) is an example of a preceding vehicle detection device that detects an inter-vehicle distance from a preceding vehicle (that is, another vehicle that travels in front of the motorcycle <NUM>). The radar <NUM> transmits electromagnetic waves, such as millimeter waves or the like, toward front of the vehicle and receives their reflected waves. The radar <NUM> is supported by the vehicle body frame <NUM> and is installed in a front portion of the motorcycle <NUM>. Note that, as the preceding vehicle detection device, a device that detects an inter-vehicle distance from a preceding vehicle is sufficient, and the preceding vehicle detection device is not limited to the radar <NUM>. The preceding vehicle detection device may be constituted of a laser, a camera, or the like.

The control device <NUM> is constituted of one or two or more microcomputers. In this embodiment, as illustrated in <FIG>, the control device <NUM> includes a plurality of control units. Specifically, the control device <NUM> includes a control unit 60A that controls the engine <NUM>, a control unit 60B that controls the front fork <NUM> and the rear suspension <NUM>, and a control unit 60C that controls the front wheel brake 8B and the rear wheel brake 9B. The control unit 60A includes an interface <NUM>, a CPU <NUM>, a ROM <NUM>, a RAM <NUM>, or the like. Although not illustrated, each of the control units 60B and 60C also includes an interface <NUM>, a CPU <NUM>, a ROM <NUM>, a RAM <NUM>, or the like. The control units 60A, 60B, and 60C are formed as separate bodies and are arranged in places apart from each other. The control units 60A, 60B, and 60C are communicably connected to each other. However, there is no limitation on a configuration of the control device <NUM>. The control device <NUM> may be constituted of a single control unit.

As described above, the motorcycle <NUM> includes the vehicle speed sensor <NUM> that detects the speed of the motorcycle <NUM> and the acceleration sensor <NUM> that detects the acceleration of the motorcycle <NUM>. The acceleration sensor <NUM> is constituted of, for example, an inertia measurement unit (IMU).

<FIG> is a functional block diagram of the control device <NUM>. The CPU <NUM> of the control device <NUM> (see <FIG>) executes computer programs stored in the ROM <NUM> or the like to function as a traveling controller <NUM> that executes cruise control, a suspension controller <NUM> that controls the front fork <NUM> and the rear suspension <NUM>, and a suspension control prohibitor 63B that prohibits control of the suspension controller <NUM>. Note that cruise control is control that causes traveling without an operation of the accelerator grip 16A by a rider. Cruise control includes control that causes the motorcycle <NUM> to follow a preceding vehicle while keeping a set inter-vehicle distance from the preceding vehicle. The ROM <NUM> or the RAM <NUM> of the control device <NUM> functions as a storage <NUM> that stores a map that will be described later. Note that the control device <NUM> may include, as the storage <NUM>, some other memory than the ROM <NUM> and the RAM <NUM>.

There is no particular limitation on a type of cruise control. Cruise control may be control in which the motorcycle <NUM> is caused to travel at a certain speed that has been set by the rider. Cruise control may be control in which the motorcycle <NUM> is caused to follow a preceding vehicle regardless of a speed of the preceding vehicle, and may be control in which the motorcycle <NUM> is caused to follow the preceding vehicle based on the speed of the preceding vehicle. In this embodiment, the traveling controller <NUM> can execute control (which will be hereinafter referred to as an adaptive cruise control) in which, when there is no preceding vehicle or when a speed of a preceding vehicle is higher than a preset speed (which will be hereinafter referred to as a set speed), the motorcycle <NUM> is caused to travel at the set speed and, when the speed of the preceding vehicle is lower than the set speed, the motorcycle <NUM> is caused to travel behind the preceding vehicle while keeping a preset inter-vehicle distance (which will be hereinafter referred to as a set distance) from the preceding vehicle. Note that the set distance may be a predetermined distance or may be a predetermined distance range. The set distance may vary in accordance with the speed of the motorcycle <NUM>. For example, when the speed of the motorcycle <NUM> is relatively high, the set distance may be a relatively long distance, and when the speed of the motorcycle <NUM> is relatively low, the set distance may be a relatively short distance.

Although not illustrated, each of the front wheel brake 8B and the rear wheel brake 9B includes a hydraulic brake caliper. The traveling controller <NUM> controls a hydraulic pressure of the brake caliper to control on and off and a braking force of each of the front wheel brake 8B and the rear wheel brake 9B. During the adaptive cruise control, the traveling controller <NUM> controls the engine <NUM>, the front wheel brake 8B, and the rear wheel brake 9B, based on at least the inter-vehicle distance detected by the radar <NUM>. In this embodiment, the traveling controller <NUM> increases or reduces an output of the engine <NUM> or actuates the front wheel brake 8B and/or the rear wheel brake 9B, based on the inter-vehicle distance detected by the radar <NUM>, the speed of the motorcycle <NUM> detected by the vehicle speed sensor <NUM>, and the acceleration of the motorcycle <NUM> detected by the acceleration sensor <NUM>. Note that an acceleration can be a positive value and a negative value. In the following, a negative acceleration will be also referred to as a deceleration.

During the adaptive cruise control, when the speed of the motorcycle <NUM> is equal to or lower than the set speed and the inter-vehicle distance is larger than the set distance, the traveling controller <NUM> increases the output of the engine <NUM>. Thus, the motorcycle <NUM> accelerates and the inter-vehicle distance reduces. Conversely, during the adaptive cruise control, when the inter-vehicle distance is reduced to be smaller than the set distance, the traveling controller <NUM> reduces the output of the engine <NUM>, and furthermore, actuates the front wheel brake 8B and/or the rear wheel brake 9B, as necessary. Thus, the motorcycle <NUM> decelerates and the inter-vehicle distance is increased. In a manner described above, the motorcycle <NUM> follows the preceding vehicle while keeping the inter-vehicle distance at the set distance.

The suspension controller <NUM> controls the damping force of the front fork <NUM>, a spring reaction force of the front fork <NUM>, the damping force of the rear suspension <NUM>, and a spring reaction force of the rear suspension <NUM>. When the damping force of the front fork <NUM> in the contraction direction is increased, a contraction operation of the front fork <NUM> becomes stiff and a posture of the vehicle body is less likely to change to a front-down posture. When the damping force of the rear suspension <NUM> in the expansion direction is increased, an expansion operation of the rear suspension <NUM> becomes stiff and the posture of the vehicle body is less likely to change to the front-down posture.

The spring reaction force of the front fork <NUM> is a reaction force to a force of the front fork <NUM> in the contraction direction. The spring reaction force of the rear suspension <NUM> is a reaction force to a force of the rear suspension <NUM> in the contraction direction. When the spring reaction force of the front fork <NUM> is increased, the front fork <NUM> is less likely to contract and the posture of the vehicle body is less likely to change to the front-down posture. When the spring reaction force of the rear suspension <NUM> is reduced, the rear suspension <NUM> is less likely to expand and the posture of the vehicle body is less likely to change to the front-down posture.

When the damping force of the front fork <NUM> in the expansion direction is increased, the expansion operation of the front fork <NUM> becomes stiff and the posture of the vehicle body is less likely to change to a front-up posture. When the damping force of the rear suspension <NUM> in the contract direction is increased, the contraction operation of the rear suspension <NUM> becomes stiff and the posture of the vehicle body is less likely to change to the front-up posture.

When the spring reaction force of the front fork <NUM> is reduced, the front fork <NUM> is less likely to expand and the posture of the vehicle body is less likely to change to the front-up posture. When the spring reaction of the rear suspension <NUM> is increased, the rear suspension <NUM> is less likely to contract and the posture of the vehicle body is less likely to change to the front-up posture.

The suspension control prohibitor 63B is configured to, when the rider operates the accelerator grip 16A, prohibit control of the suspension controller <NUM>. The suspension control prohibitor 63B receives a signal from the accelerator grip 16A and determines whether the accelerator grip 16A is being operated. When the suspension control prohibitor 63B detects that the accelerator grip 16A is being operated, the suspension control prohibitor 63B transmits a signal to the suspension controller <NUM> to disable control of the suspension controller <NUM>.

Next, with reference to a flowchart of <FIG>, an example of adaptive cruise control performed by the motorcycle <NUM> will be described.

First, in Step S1, vehicle information and an inter-vehicle distance are acquired. The inter-vehicle distance is detected by the radar <NUM>. The vehicle information is driving information of the motorcycle <NUM> as an own vehicle and driving information of a preceding vehicle (that is, another vehicle traveling in front of the motorcycle <NUM>). In Step S1, the traveling controller <NUM> of the control device <NUM> acquires a speed and an acceleration of the motorcycle <NUM> and a speed and an acceleration of the preceding vehicle. Note that the speed and the acceleration of the preceding vehicle can be calculated based on the driving information of the motorcycle <NUM> and a detection value of the radar <NUM>.

In Step S2, a target acceleration necessary for keeping the inter-vehicle distance from the preceding vehicle at a set distance as the motorcycle <NUM> travels at a speed equal to or lower than the set speed is calculated by the traveling controller <NUM>. Note that, in the following, a negative target acceleration will be also referred to as a target deceleration.

Subsequently, the process proceeds to Step S3 and whether the motorcycle <NUM> needs to accelerate is determined. Specifically, the traveling controller <NUM> determines whether the target acceleration is higher than zero. For example, when the inter-vehicle distance is larger than the set distance, the motorcycle <NUM> needs to accelerate in order to reduce the inter-vehicle distance. In that case, the target acceleration is higher than zero.

When a determination result of Step S3 is YES, the process proceeds to Step S4 and the suspension controller <NUM> executes at least one of increasing the damping force of the front fork <NUM> in the expansion direction, reducing the spring reaction force of the front fork <NUM>, increasing the damping force of the rear suspension <NUM> in the contraction direction, and increasing the spring reaction force of the rear suspension <NUM>. In this case, the suspension controller <NUM> increases the damping force of the front fork <NUM> in the expansion direction and the damping force of the rear suspension <NUM> in the contraction direction. Thus, an expansion operation of the front fork <NUM> and a contraction operation of the rear suspension <NUM> become stiff and the vehicle body is less likely to change to the front-up posture at acceleration.

In this embodiment, the suspension controller <NUM> increases the damping force of the front fork <NUM> in the expansion direction and the damping force of the rear suspension <NUM> in the contraction direction in accordance with the target acceleration of the motorcycle <NUM>. The suspension controller <NUM> causes the damping force of the front fork <NUM> in the expansion direction and the damping force of the rear suspension <NUM> in the contraction direction to increase as the acceleration of the motorcycle <NUM> increases. The storage <NUM> of the control device <NUM> stores a map defining a relationship between the target acceleration and each of the damping force of the front fork <NUM> in the expansion direction and the damping force of the rear suspension <NUM> in the contraction direction. The map is set such that, as the target acceleration increases, the damping force of the front fork <NUM> in the expansion direction and the damping force of the rear suspension <NUM> in the contraction direction increase. The suspension controller <NUM> controls the damping forces of the front fork <NUM> and the rear suspension <NUM>, based on the map.

Thereafter, the process proceeds to Step S5 and the traveling controller <NUM> increases the output of the engine <NUM>. As a result, the motorcycle <NUM> accelerates. At this time, the expansion operation of the front fork <NUM> and the contraction operation of the rear suspension <NUM> have become stiff due to processing of Step S4, and therefore, the vehicle body is suppressed from becoming the front-up posture. Accordingly, occurrence of pitching due to acceleration can be suppressed.

When the determination result of Step S3 is NO, the process proceeds to Step S6 and whether the motorcycle <NUM> needs to decelerate is determined. Specifically, the traveling controller <NUM> determines whether the target acceleration is lower than zero. For example, when the inter-vehicle distance is smaller than the set distance, the motorcycle <NUM> needs to decelerate in order to increase the inter-vehicle distance. In that case, the target acceleration is lower than zero.

When a determination result of Step S6 is YES, the process proceeds to Step S7 and the suspension controller <NUM> executes at least one of increasing the damping force of the front fork <NUM> in the contraction direction, increasing the spring reaction force of the front fork <NUM>, increasing the damping force of the rear suspension <NUM> in the expansion direction, and reducing the spring reaction force of the rear suspension <NUM>. In this case, the suspension controller <NUM> increases the damping force of the front fork <NUM> in the contraction direction and the damping force of the rear suspension <NUM> in the expansion direction. Thus, the contraction operation of the front fork <NUM> and the expansion operation of the rear suspension <NUM> become stiff and the vehicle body is less likely to change to the front-down posture at deceleration.

In this embodiment, the suspension controller <NUM> increases the damping force of the front fork <NUM> in the contraction direction and the damping force of the rear suspension <NUM> in the expansion direction in accordance with the target acceleration of the motorcycle <NUM> (specifically, the target deceleration that is the negative target acceleration). The suspension controller <NUM> causes the damping force of the front fork <NUM> in the contraction direction and the damping force of the rear suspension <NUM> in the expansion direction to increase as the target acceleration of the motorcycle <NUM> reduces (in other words, as the target deceleration increases). The storage <NUM> of the control device <NUM> stores a map defining a relationship between the target deceleration and each of the damping force of the front fork <NUM> in the contraction direction and the damping force of the rear suspension <NUM> in the expansion direction. The map is set such that, as the target deceleration increases, the damping force of the front fork <NUM> in the contraction direction and the damping force of the rear suspension <NUM> in the expansion direction increase. The suspension controller <NUM> controls the damping forces of the front fork <NUM> and the rear suspension <NUM>, based on the map.

Thereafter, the process proceeds to Step S8 and the traveling controller <NUM> reduces the output of the engine <NUM>, and furthermore, actuates the front wheel brake 8B and/or the rear wheel brake 9B, as necessary. As a result, the motorcycle <NUM> decelerates. At this time, the contraction operation of the front fork <NUM> and the expansion operation of the rear suspension <NUM> have become stiff due to processing of Step S7, and therefore, the vehicle body is suppressed from becoming the front-down posture. Accordingly, occurrence of pitching due to deceleration can be suppressed.

Note that, during the above-described control, when the rider operates the accelerator grip 16A, the suspension control prohibitor 63B prohibits control of the suspension controller <NUM>. In this case, the damping forces of the front fork <NUM> and the rear suspension <NUM> are not changed. In this embodiment, when the rider operates the accelerator grip 16A, adaptive cruise control is temporarily canceled. Accordingly, control of the front fork <NUM> and the rear suspension <NUM> by the suspension controller <NUM> is temporarily canceled. Note that, thereafter, when the rider stops operating the accelerator grip 16A, adaptive cruise control is restarted. Accordingly, control of the front fork <NUM> and the rear suspension <NUM> by the suspension controller <NUM> is restarted.

As has been described above, according to the motorcycle <NUM> of this embodiment, during the adaptive cruise control, at least one of the damping force of the front fork <NUM>, the spring reaction force of the front fork <NUM>, the damping force of the rear suspension <NUM>, and the spring reaction force of the rear suspension <NUM> is controlled in accordance with acceleration or deceleration of the motorcycle <NUM>. In the above-described control example, the suspension controller <NUM> of the control device <NUM> increases the damping force of the front fork <NUM> in the expansion direction and the damping force of the rear suspension <NUM> in the contraction direction when the motorcycle <NUM> accelerates during the adaptive cruise control. Therefore, when the motorcycle <NUM> accelerates, the vehicle body is suppressed from becoming the front-up posture. The suspension controller <NUM> increases the damping force of the front fork <NUM> in the contraction direction and the damping force of the rear suspension <NUM> in the expansion direction when the motorcycle <NUM> decelerates during the adaptive cruise control. Therefore, when the motorcycle <NUM> decelerates, the vehicle body is suppressed from becoming the front-down posture. According to this embodiment, during adaptive cruise control, pitching due to acceleration or deceleration can be suppressed, so that riding comfort during adaptive cruise control can be increased.

According to this embodiment, the suspension controller <NUM> causes the damping force of the front fork <NUM> in the expansion direction and the damping force of the rear suspension <NUM> in the contraction direction to increase as the acceleration of the motorcycle <NUM> increases when the motorcycle <NUM> accelerates during execution of adaptive cruise control. Stiffness in the expansion operation of the front fork <NUM> and the contraction operation of the rear suspension <NUM> is adjusted in accordance with the acceleration of the motorcycle <NUM>. Accordingly, when the motorcycle <NUM> accelerates, the vehicle body can be preferably suppressed from becoming the front-up posture. The suspension controller <NUM> causes the damping force of the front fork <NUM> in the contraction direction and the damping force of the rear suspension <NUM> in the expansion direction to increase as the deceleration of the motorcycle <NUM> increases when the motorcycle <NUM> decelerates during execution of adaptive cruise control. Stiffness in the contraction operation of the front fork <NUM> and the expansion operation of the rear suspension <NUM> is adjusted in accordance with the deceleration of the motorcycle <NUM>. Accordingly, when the motorcycle <NUM> decelerates, the vehicle body can be preferably suppressed from becoming the front-down posture. According to this embodiment, riding comfort during adaptive cruise control can be further increased.

Moreover, according to this embodiment, the suspension controller <NUM> increases the damping force of the front fork <NUM> in the expansion direction and the damping force of the rear suspension <NUM> in the contraction direction prior to increase of the output of the engine <NUM> when the motorcycle <NUM> accelerates. Therefore, the vehicle body can be more effectively suppressed from becoming the front-up posture. Also, the suspension controller <NUM> increases the damping force of the front fork <NUM> in the contraction direction and the damping force of the rear suspension <NUM> in the expansion direction prior to reduction of the output of the engine <NUM> or actuation of the front wheel brake 8B and/or the rear wheel brake 9B when the motorcycle <NUM> decelerates. Therefore, the vehicle body can be more effectively suppressed from becoming the front-down posture. Accordingly, riding comfort during adaptive cruise control can be further increased.

According to this embodiment, the suspension controller <NUM> controls the damping forces of the front fork <NUM> and the rear suspension <NUM>, based on the map stored in the storage <NUM>. Therefore, in controlling the damping forces of the front fork <NUM> and the rear suspension <NUM>, a load of and a time required for a calculation of the control device <NUM> can be reduced. When the motorcycle <NUM> accelerates or decelerates, the damping forces of the front fork <NUM> and the rear suspension <NUM> can be adjusted in a short time.

According to this embodiment, when the rider operates the accelerator grip 16A, control of the suspension controller <NUM> is prohibited. Control of the suspension controller <NUM> can be disabled by an intension of the rider.

One embodiment of the straddled vehicle has been described above, but the above-described embodiment is merely an example. Various other embodiments are also possible.

The above-described control by the suspension controller <NUM> is merely an example. In Step S4 and/or Step S7 described above, the suspension controller <NUM> may be configured to perform control of the spring reaction force of the front fork <NUM> and/or the rear suspension <NUM>, instead of or together with control of the damping forces of the front fork <NUM> and the rear suspension <NUM>. The suspension controller <NUM> may be configured to, in Step S4, reduce the spring reaction force of the front fork <NUM> and/or increase the spring reaction force of the rear suspension <NUM>. The suspension controller <NUM> may be configured to, in Step S7, increase the spring reaction force of the front fork <NUM> and/or reduce the spring reaction force of the rear suspension <NUM>. The storage <NUM> may be configured to store a map defining a relationship between the target acceleration and each of the spring reaction force of the front fork <NUM> and the spring reaction force of the rear suspension <NUM>. The suspension controller <NUM> may be configured to control the spring reaction force of the front fork <NUM> and/or the rear suspension <NUM>, based on the map.

In the above-described embodiment, in Step S4 and Step S7, the suspension controller <NUM> changes both the damping force of the front fork <NUM> and the damping force of the rear suspension <NUM>, but the suspension controller <NUM> may be configured to change only one of the damping force of the front fork <NUM> and the damping force of the rear suspension <NUM>.

The front fork <NUM> is an example of an electronically controlled front suspension, but the front suspension is not limited to the front fork <NUM>. The front suspension is not limited to a front suspension including a telescopic type mechanism, but may be a front suspension including a telelever type mechanism.

The straddled vehicle is a vehicle that a rider straddles to ride. The straddled vehicle is not limited to the motorcycle <NUM>. The straddled vehicle may be, for example, a motor tricycle, an all-terrain vehicle (ATV), a snowmobile, or the like.

The terms and expressions used herein are for description only and are not to be interpreted in a limited sense. These terms and expressions should be recognized as not excluding any equivalents to the elements shown and described herein and as allowing any modification encompassed in the scope of the claims. The present invention may be embodied in many various forms. Specification and drawings should be regarded as providing preferred embodiments of the present invention. These preferred embodiments are provided with the understanding that they are not intended to limit the present invention to the preferred embodiments described in the specification and/or shown in the drawings. The present invention is not limited to the preferred embodiment described herein, but can be modified within the scope of the appended claims.

Claim 1:
A straddled vehicle (<NUM>) comprising:
a vehicle body frame (<NUM>);
a front wheel (<NUM>) supported by the vehicle body frame (<NUM>);
a rear wheel (<NUM>) supported by the vehicle body frame (<NUM>);
a front wheel brake (8B) that brakes the front wheel (<NUM>);
a rear wheel brake (9B) that brakes the rear wheel (<NUM>);
a drive source (<NUM>) that is supported by the vehicle body frame (<NUM>) and drives the rear wheel (<NUM>);
an electronically controlled front suspension (<NUM>) connected to the vehicle body frame (<NUM>) and the front wheel (<NUM>);
an electronically controlled rear suspension (<NUM>) connected to the vehicle body frame (<NUM>) and the rear wheel (<NUM>); and
a control device (<NUM>) connected to the front wheel brake (8B), the rear wheel brake (9B), the drive source (<NUM>), the front suspension (<NUM>), and the rear suspension (<NUM>),
wherein
the control device (<NUM>) includes
a traveling controller (<NUM>) that executes cruise control by controlling at least one of the front wheel brake (8B), the rear wheel brake (9B), and the drive source (<NUM>), and
a suspension controller (<NUM>) that, when the traveling controller (<NUM>) accelerates or decelerates the straddled vehicle (<NUM>) during the cruise control, control at least one of a damping force of the front suspension (<NUM>), a spring reaction force of the front suspension (<NUM>), a damping force of the rear suspension (<NUM>), and a spring reaction force of the rear suspension (<NUM>);
wherein
the suspension controller (<NUM>) is configured to, when the traveling controller (<NUM>) accelerates the straddled vehicle (<NUM>) during the cruise control, increase a damping force of the front suspension (<NUM>) in an expansion direction and/or a damping force of the rear suspension (<NUM>) in a contraction direction;
an accelerator operator (16A) that is supported by the vehicle body frame (<NUM>) and is operated by a rider,
characterized in that
the control device (<NUM>) includes a suspension control prohibitor (63B) that prohibits control of the suspension controller (<NUM>) when the accelerator operator (16A) is operated.