Lean vehicle

Abstract

A vehicle body frame (5) of a leaning vehicle (1) inclines in a direction among the vehicle left and right directions which is the same as the turning direction at least when turning at a vehicle velocity (V) in a high-velocity region (AV2), and inclines in a direction among the vehicle left and right directions which is opposite to the turning direction when turning at a vehicle velocity in an ultra-low velocity region (AV1) lower than the high-velocity region (AV2). A control device (9) of the leaning vehicle (1) controls at least one of steering torque and driving torque applied by a torque application device (10), on the basis of at least information detected by a lean angle-related information detection device (6), a steering angle-related information detection device (7), and a wheel velocity-related information detection device (8), such that when a lean angle (φ) toward a direction among the vehicle left and right directions which is opposite to the turning direction is less than a positive first value during turning of the leaning vehicle at a vehicle velocity (V) in the ultra-low velocity region (AV1), the lean angle (φ) is increased in the direction among the vehicle left and right directions which is opposite to the turning direction while the leaning vehicle turns in the vehicle velocity (V) in the ultra-low velocity region (AV1).

Description

[Technical Field]

[0001] The present invention relates to a lean vehicle, such as a motorcycle. [Background technology]

[0002] Lean-mounted vehicles, such as motorcycles, have the characteristic that when turning, the body tilts in the same direction as the turning direction. However, when turning at extremely low speeds, the body of the lean-mounted vehicle tilts in the opposite direction to the turning direction. By adjusting the amount of body tilt during turning to an appropriate amount according to the vehicle speed and steering angle, the lean-mounted vehicle can turn smoothly. Furthermore, the body tilt of a lean-mounted vehicle is more likely to change than that of an automobile. Therefore, technologies have been proposed to control lean-mounted vehicles so that they can turn smoothly.

[0003] For example, a motorcycle control device described in Patent Document 1 controls the attitude of the motorcycle by controlling a drive torque generating means so that a drive torque set based on the detected steering angle, vehicle speed, and roll angle is applied to the wheels. Specifically, a target yaw rate is first calculated from the steering angle, vehicle speed, and a target yaw rate calculation map. Next, a target roll angle is calculated from the target yaw rate, and a target roll rate is calculated from the target roll angle and the detected roll angle. Then, a drive torque is set based on the target roll rate. The target roll angle is calculated based on an equation that represents the balance between a first roll moment due to gravity acting on the vehicle body and a second roll moment calculated from the target yaw rate and vehicle speed. Through this calculation, the target roll angle is calculated as atan(V·ω / g). Here, V represents vehicle speed L, ω represents the target yaw rate, and g represents gravitational acceleration. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5418512 Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, the target yaw rate is set to a smaller value as the steering angle decreases if the vehicle speed is the same, and the target roll angle is set to a smaller value as the target yaw rate decreases if the vehicle speed is the same. Therefore, the technology in Patent Document 1 cannot control the posture of a lean vehicle so that the vehicle body tilts in the left-right direction opposite to the turning direction when turning.

[0006] Lean vehicles are required to be able to turn more smoothly at extremely low speeds.

[0007] An object of the present invention is to provide a lean vehicle that can turn more smoothly when turning at an extremely low speed. [Means for solving the problem]

[0008] A lean vehicle according to one embodiment of the present invention has the following configuration. a vehicle body frame that supports the plurality of wheels rotatably about an axle and the at least one front wheel rotatably about a steering axis, and that tilts in the same direction as the turning direction in the left-right direction of the vehicle when turning at least at a vehicle speed in a high-speed range; a lean angle-related information detection device that detects information related to a lean angle, which is the tilt angle of the body frame in the left-right direction of the vehicle with respect to the up-down direction of the vehicle; and a steering angle-related information detection device that detects information related to a steering angle, which is the rotation angle of any one of the front wheels about the steering axis. a torque applying device including at least one of a driving torque applying device configured to apply positive and negative driving torque about the axle to at least one of the at least one front wheel and the at least one rear wheel, and a steering torque applying device configured to apply steering torque about the steering axis to the at least one front wheel, and a control device configured to control at least one of the driving torque and the steering torque applied by the torque applying device. The vehicle body frame tilts in the left-right direction of the vehicle opposite to the turning direction when turning at a vehicle speed in an extremely low speed range lower than the high speed range. When the lean vehicle is turning at the vehicle speed in the extremely low speed region and the lean angle in the direction opposite to the turning direction in the left-right direction of the vehicle is smaller than a first value, which is a positive value, the control device executes a first extremely low speed control that controls at least one of the driving torque and the steering torque based at least on information detected by the lean angle related information detection device, the steering angle related information detection device, and the wheel speed related information detection device so that the lean angle in the direction opposite to the turning direction in the left-right direction of the vehicle increases while the lean vehicle is turning at the vehicle speed in the extremely low speed region.

[0009] According to this configuration, the body frame of the lean vehicle tilts in the same direction as the turning direction in the left-right direction of the vehicle when turning at least at a vehicle speed in the high-speed range, and tilts in the opposite direction to the turning direction in the left-right direction of the vehicle when turning at a vehicle speed in the extremely low-speed range that is lower than the high-speed range. The value of the lean angle that can suppress changes in the posture of the lean vehicle when turning at a vehicle speed in the extremely low-speed range varies depending on, for example, the dimensions, steering angle, and vehicle speed of the lean vehicle. The control device for the lean vehicle executes first extremely low-speed control that controls at least one of the drive torque and the steering torque based at least on information detected by the lean angle-related information detection device, the steering angle-related information detection device, and the wheel speed-related information detection device so as to increase the lean angle in the direction opposite to the turning direction when the lean vehicle is turning at a vehicle speed in the extremely low-speed range. Therefore, when the first value is equal to or smaller than the lean angle value that can suppress changes in the posture of the lean vehicle, the first very low speed control is executed, thereby enabling the lean vehicle to turn smoothly. Therefore, the lean vehicle can turn more smoothly when turning at very low speed.

[0010] A lean vehicle according to an embodiment of the present invention may have the following configuration. During the first extremely low speed control, when the lean angle in the direction opposite to the turning direction in the left-right direction of the vehicle is smaller than the first value at a first point in time while the lean vehicle is turning at the vehicle speed in the extremely low speed region, the control device controls at least one of the driving torque and the steering torque based at least on information detected by the lean angle-related information detection device, the steering angle-related information detection device, and the wheel speed-related information detection device so that the lean angle in the direction opposite to the turning direction in the left-right direction of the vehicle increases while the lean vehicle is turning at the vehicle speed in the extremely low speed region, and the first value differs depending on at least the steering angle and the vehicle speed at the first point in time.

[0011] According to this configuration, a lean vehicle can turn more smoothly at extremely low speeds compared to when the first value is constant regardless of the steering angle and the vehicle speed.

[0012] A lean vehicle according to an embodiment of the present invention may have the following configuration. When the lean vehicle is turning at the vehicle speed in the extremely low speed region and the lean angle in the direction opposite to the turning direction in the left-right direction of the vehicle is greater than a second value, which is a positive value, the control device executes a second extremely low speed control that controls at least one of the driving torque and the steering torque based at least on information detected by the lean angle related information detection device, the steering angle related information detection device, and the wheel speed related information detection device so that the lean angle in the direction opposite to the turning direction in the left-right direction of the vehicle decreases while the lean vehicle is turning at the vehicle speed in the extremely low speed region.

[0013] According to this configuration, when the lean angle in the direction opposite to the turning direction is greater than the second value during turning of the lean vehicle at a vehicle speed in the very low speed range, the control device executes second very low speed control, which controls at least one of the drive torque and the steering torque based at least on the information detected by the lean angle-related information detection device, the steering angle-related information detection device, and the wheel speed-related information detection device, so as to reduce the lean angle in the direction opposite to the turning direction. Therefore, when the second value is equal to or greater than the lean angle value that can suppress changes in the posture of the lean vehicle, the second very low speed control is executed, thereby enabling the lean vehicle to turn more smoothly when turning at very low speeds.

[0014] A lean vehicle according to an embodiment of the present invention may have the following configuration. In the second extremely low speed control, when the lean angle in the direction opposite to the turning direction in the left-right direction of the vehicle is greater than the second value at a second point in time while the lean vehicle is turning at the vehicle speed in the extremely low speed region, the control device controls at least one of the driving torque and the steering torque based at least on information detected by the lean angle-related information detection device, the steering angle-related information detection device, and the wheel speed-related information detection device so that the lean angle in the direction opposite to the turning direction in the left-right direction of the vehicle decreases while the lean vehicle is turning at the vehicle speed in the extremely low speed region, and the second value differs depending on at least the steering angle and the vehicle speed at the second point in time.

[0015] According to this configuration, a lean vehicle can turn more smoothly at extremely low speeds compared to when the second value is constant regardless of the steering angle and the vehicle speed.

[0016] A lean vehicle according to an embodiment of the present invention may have the following configuration. The torque applying device includes at least the driving torque applying device of the driving torque applying device and the steering torque applying device. In the first extremely low speed control, when the lean angle in the direction opposite to the turning direction in the left-right direction of the vehicle is smaller than the first value, which is a positive value, while the lean vehicle is turning at the vehicle speed in the extremely low speed region, the control device controls at least the driving torque of the driving torque and the steering torque based at least on information detected by the lean angle related information detection device, the steering angle related information detection device, and the wheel speed related information detection device so that the lean angle in the direction opposite to the turning direction in the left-right direction of the vehicle increases while the lean vehicle is turning at the vehicle speed in the extremely low speed region.

[0017] According to this configuration, the torque applying device includes at least one of a driving torque applying device and a steering torque applying device, and the control device controls at least the driving torque of the driving torque and the steering torque during the first very low speed control. For example, motorcycles, tricycles, and electric bicycles have driving torque applying devices that apply driving torque to at least one of the front and rear wheels. Therefore, when the lean vehicle is a motorcycle, tricycle, or electric bicycle, the existing driving torque applying device can be used to more smoothly turn the lean vehicle at very low speeds.

[0018] A lean vehicle according to an embodiment of the present invention may have the following configuration. The control device executes the first extremely low speed control in at least one of a state in which the lean vehicle is traveling autonomously without being driven by a rider, and a state in which the lean vehicle is traveling while being driven by a rider.

[0019] With this configuration, when the lean vehicle is traveling autonomously without being driven by a rider at a vehicle speed in the extremely low speed range, or when the lean vehicle is traveling driven by a rider at a vehicle speed in the extremely low speed range, the first extremely low speed control can be used to make the lean vehicle turn smoothly. Furthermore, when the lean vehicle is traveling autonomously without being driven by a rider, the relationship between the lean angle, steering angle, and vehicle speed does not change due to the rider's driving, so the lean vehicle can turn more smoothly at extremely low speeds.

[0020] The control device for a lean vehicle of the present invention is configured to execute a first extremely low speed control. The control device for a lean vehicle of the present invention may be configured to execute a second extremely low speed control. For the purposes of the following description, the term "extremely low speed control" will be used to collectively refer to at least one of the first extremely low speed control and the second extremely low speed control executed by the control device.

[0021] The vehicle up-down direction in the present invention and the embodiments is the direction perpendicular to the riding surface. More specifically, it is the direction perpendicular to the contact point of the wheels. The riding surface is the road surface on which the lean vehicle rides. The vehicle fore-aft direction in the present invention and the embodiments is the direction fixed to the body frame and is the direction of travel of the lean vehicle when the lean vehicle is traveling straight. The vehicle left-right direction in the present invention and the embodiments is the direction perpendicular to the vehicle fore-aft direction and the vehicle up-down direction. When a rider rides on a lean vehicle, the vehicle left-right direction is the left-right direction from the rider's perspective.

[0022] In the present invention and embodiments, the plurality of wheels including at least one front wheel and at least one rear wheel may include one front wheel and one rear wheel, one front wheel and multiple rear wheels, or multiple front wheels and one rear wheel. In the present invention and embodiments, the lean vehicle may be a two-wheeled vehicle or a three-wheeled vehicle. The lean vehicle may be a motorcycle or a motor tricycle. Motorcycles also include scooters and mopeds. The lean vehicle may be a two-wheeled or three-wheeled bicycle.

[0023] A lean vehicle according to the present invention and the embodiments may have a positive caster angle. In other words, the steering axis may be tilted backward. The caster angle is the angle between the steering axis and the vertical direction of the vehicle, and is considered positive when the steering axis is tilted backward. A lean vehicle according to the present invention and the embodiments may have a positive trail. Trail is the distance between the ground contact point of the front wheels and the intersection of the steering axis and the road surface. In other words, trail is the distance in the front-to-rear direction of the vehicle between the axle of the front wheels and the intersection of the steering axis and the road surface. A state in which the trail is positive is a state in which the ground contact point of the front wheels is located further forward of the intersection of the steering axis and the road surface. A lean vehicle according to the present invention and the embodiments may have a negative trail. A lean vehicle according to the present invention and the embodiments may be configured so that the trail is unchangeable. A lean vehicle according to the present invention and the embodiments may be configured so that the trail is changeable. The trail may be varied within a range of positive values, or the trail may be varied from positive values ​​to negative values.

[0024] The lean vehicle of the present invention and the embodiments may be configured so that the rear wheels are not steerable. The lean vehicle of the present invention and the embodiments may not have a mechanism that can change the lean angle without changing the steering angle of the front wheels. The lean vehicle of the present invention and the embodiments may not have a mechanism that can change the center of gravity position of the body frame without changing the steering angle of the front wheels.

[0025] The lean vehicle of the present invention and the embodiments may or may not have a rider on board when the control device executes the ultra-low speed control. The lean vehicle of the present invention and the embodiments may be in a state of autonomous driving without being driven by a rider, or may be in a state of driving and being driven by a rider when the control device executes the ultra-low speed control. If the ultra-low speed control is executed when the lean vehicle is driven and traveling by a rider, the ultra-low speed control assists the rider in driving. The lean vehicle of the present invention and the embodiments may or may not have a handle unit operated by the rider to maintain or change the steering angle. The lean vehicle of the present invention and the embodiments may or may not have at least one operator (e.g., an accelerator operator, a brake operator, bicycle pedals, etc.) operated by the rider to maintain or change the vehicle speed. The lean vehicle of the present invention and the embodiments may be configured to be switchable between a mode in which the ultra-low speed control is not performed and a mode in which the ultra-low speed control is performed.

[0026] In the present invention and its embodiments, "supporting multiple wheels rotatably around their axles" means supporting multiple wheels rotatably around their respective axles. In the present invention and its embodiments, when there are multiple front wheels, "supporting at least one front wheel rotatably around its steering axis" means supporting multiple front wheels rotatably around their respective steering axes. In the present invention and its embodiments, a wheel (front wheel or rear wheel) includes a tire and a wheel body that holds the tire. In the present invention and its embodiments, the portion of the outer edge of the front wheel that contacts the running surface in a cross section perpendicular to the circumferential direction of the front wheel may be arc-shaped.

[0027] In the present invention and embodiments, the information related to the lean angle detected by the lean angle-related information detection device may include at least one of the lean angle, the lean angular velocity which is the time rate of change of the lean angle, and the lean angular acceleration which is the time rate of change of the lean angular velocity. The lean angle may be a so-called roll angle. The lean angle-related information detection device may be, for example, an IMU (Inertial Measurement Unit).

[0028] In the present invention and embodiments, the information related to the steering angle detected by the steering angle-related information detection device may include at least one of the steering angle, steering angular velocity, which is the time rate of change of the steering angle, and steering angular acceleration, which is the time rate of change of the steering angular velocity. In the present invention, the steering angle is the rotation angle of any one front wheel about the steering axis. When a lean vehicle is traveling straight, the steering angle is zero. Note that the term "any one front wheel" does not intend to limit the number of front wheels to multiple. A lean vehicle may have only one front wheel. When the lean vehicle has multiple front wheels, the lean vehicle may be configured so that the rotation angles of the multiple front wheels about the steering axis are always the same. When the lean vehicle has multiple front wheels, the lean vehicle may be configured so that the rotation angles of the multiple front wheels about the steering axis can be slightly different. In this case, the rotation angle of any one front wheel about the steering axis is related to the rotation angles of the remaining front wheels about the steering axis. The lean vehicle may have two front wheels, and the rotation angle of the steering unit may be an angle between the rotation angles of the two front wheels about the steering axis. In this case, the information related to the steering angle of any one of the front wheels detected by the steering angle-related information detection device may be at least one of the rotation angle of the steering unit, the rotation angular velocity of the steering unit, and the rotation angular acceleration of the steering unit. The steering angle-related information detection device may also be a sensor that supports the front wheels rotatably about their axles and detects the rotation angle of a steering shaft that is supported on the vehicle body frame rotatably about the steering axis. The steering angle-related information detection device may include a sensor that detects the rotation angle of a shaft of an electric motor provided in the steering torque application device.

[0029] In the present invention and embodiments, the information related to wheel speed detected by the wheel speed-related information detection device may include at least one of the rotational speed of the front wheels about their axles, the rotational acceleration of the front wheels about their axles, the amount of rotation (number of rotations or rotation angle) of the front wheels about their axles, the rotational speed of the rear wheels about their axles, the rotational acceleration of the rear wheels about their axles, the amount of rotation of the rear wheels about their axles, the vehicle speed (vehicle longitudinal speed), and the acceleration in the vehicle longitudinal direction. In the present invention, the wheel speed refers to the rotational angle of any one of the wheels about its axle. The rotational speed of one wheel about its axle is related to the rotational speed of the remaining wheels about their axles. The rotational speed around the axles is the number of rotations or rotation angle per unit time. The wheel speed-related information detection device may be a sensor provided on the wheel. The wheel speed-related information detection device may be a device that detects information related to the wheel speed of a lean vehicle using a GNSS (Global Navigation Satellite System). The control device may calculate the vehicle speed from the rotational speed of the front wheels about their axles and the steering angle.The control device may calculate the vehicle speed from the rotational speed of the rear wheels about their axles.

[0030] In the present invention and its embodiments, the steering torque imparting device generates a steering torque and imparts the generated steering torque to at least one front wheel. In the present invention and its embodiments, being configured to impart a steering torque about a steering axis to a front wheel means being configured to impart a steering torque to a member that supports the front wheel rotatably about an axle. For example, the steering torque imparting device may be configured to support the front wheel rotatably about an axle and to impart a steering torque to a steering shaft that is supported on the vehicle frame rotatably about the steering axis. When a lean vehicle has multiple front wheels, the values ​​of the steering torque imparted to the multiple front wheels may be the same or different. In the present invention, the term "steering torque" refers to the steering torque imparted to one front wheel or collectively refers to multiple steering torques imparted to multiple front wheels. The steering torque imparting device includes, for example, an electric motor or a hydraulic actuator as an actuator that generates the steering torque. If the lean vehicle has multiple front wheels, the number of actuators that the steering torque imparting device has may be one or the same as the number of front wheels.If the lean vehicle has an electric power steering device, an assist motor (electric motor) that assists the steering force input by the rider in the electric power steering device may function as the actuator of the steering torque imparting device of the present invention.Furthermore, the lean vehicle may have a steer-by-wire system that includes the steering torque imparting device.

[0031] In the present invention and embodiments, the driving torque applying device generates driving torque and applies the generated driving torque to at least one of at least one front wheel and at least one rear wheel. The driving torque applying device may be configured to apply driving torque only to at least one front wheel, to apply driving torque only to at least one rear wheel, or to apply driving torque to both at least one front wheel and at least one rear wheel. When the driving torque applying device is configured to apply driving torque to both at least one front wheel and at least one rear wheel, the driving torque does not necessarily have to be applied to at least one front wheel and at least one rear wheel simultaneously. When driving torque is applied to multiple wheels simultaneously, the value of the driving torque applied to any one wheel may be the same as or different from the value of the driving torque applied to the remaining wheels. In the present invention, the term "driving torque" refers to driving torque applied to one wheel or a collective term for multiple driving torques applied to multiple wheels, respectively.

[0032] In the present invention and the embodiments, being configured to apply positive and negative drive torque means being configured to be able to apply positive drive torque and negative drive torque to one wheel at different times. Positive drive torque is torque that rotates the wheel in a positive direction so that a lean vehicle moves forward. If negative drive torque is applied when the wheel is rotating in a positive direction, the rotation of the wheel in the positive direction slows down. In the present invention and the embodiments, the drive torque applying device may or may not be configured to generate torque that rotates the wheel in a negative direction as negative drive torque.

[0033] In the present invention and the embodiments, the driving torque imparting device may include multiple devices that each impart a torque to one wheel. In this case, a composite torque of multiple torques simultaneously imparted to one wheel corresponds to the driving torque of the present invention. Also, in this case, the driving torque imparting device may be configured to simultaneously impart positive torque and negative torque to one wheel. In the present invention and the embodiments, the driving torque imparting device may include at least one of an engine and an electric motor. The driving torque imparting device may include a brake device. The brake device may be, for example, a hydraulic brake device. A lean vehicle may not have a brake device included in the driving torque imparting device, or may have a brake device that is not included in the driving torque imparting device. If the control device does not control the brake device based on information detected by the lean angle related information detection device, the steering angle related information detection device, and the wheel speed related information detection device during execution of the extremely low speed control, the brake device is not included in the driving torque imparting device.

[0034] In the present invention and embodiments, the torque applying device may include both a driving torque applying device and a steering torque applying device, may include only a driving torque applying device, or may include only a steering torque applying device. An example of a case in which the torque applying device includes only a steering torque applying device is when the lean vehicle of the present invention is applied to a two-wheeled or three-wheeled bicycle.

[0035] In the present invention, when the torque applying device includes both a driving torque applying device and a steering torque applying device, the control device is configured to control both the driving torque and the steering torque. When the torque applying device includes both a driving torque applying device and a steering torque applying device, the control device can select, in the first very low speed control, a state in which both the driving torque and the steering torque are controlled simultaneously based on at least the information detected by the three detection devices (the lean angle related information detecting device, the steering angle related information detecting device, and the wheel speed related information detecting device), a state in which only the driving torque is controlled based on at least the information detected by the three detection devices, or a state in which only the steering torque is controlled based on at least the information detected by the three detection devices. When the control device of the present invention is configured to perform the second extremely low speed control and the torque application device includes both a driving torque application device and a steering torque application device, the control device can select, in the second extremely low speed control, a state in which both the driving torque and the steering torque are controlled simultaneously based at least on information detected by the three detection devices, a state in which only the driving torque is controlled based at least on information detected by the three detection devices, or a state in which only the steering torque is controlled based at least on information detected by the three detection devices. The control device may determine the type of torque to be controlled based on information detected by the three detection devices in the first extremely low speed control, based on information input to the control device. This also applies to the second extremely low speed control. The information input to the control device may be information input to the control device by a user's operation, information indicating the behavior of a lean vehicle, or both. The user's operation may be an operation by the rider to drive the lean vehicle, or an operation performed by the user (including the rider) while the lean vehicle is stopped. When both the drive torque and the steering torque are controlled based on the information detected by the three detectors during the period from the start to the end of the first very low speed control, the timing at which the drive torque controlled based on the information detected by the three detectors is applied and the timing at which the steering torque controlled based on the information detected by the three detectors are applied may be the same or different. This also applies to the second very low speed control.When the only torque controlled based on at least the information detected by the three detectors during the first very low speed control is the steering torque, the control device may control the drive torque during execution of the first very low speed control without using the information detected by the three detectors. More specifically, for example, the control device may control the drive torque in response to the rider's operation of the accelerator or brake operator. This also applies to the second very low speed control.

[0036] In the present invention and embodiments, the term "the body frame tilting in the same direction as the turning direction in the left-right direction of the vehicle when turning" means that the body frame tilts to the right of the vehicle when turning to the right, and tilts to the left of the vehicle when turning to the left. The term "the body frame tilting in the opposite direction to the turning direction in the left-right direction of the vehicle when turning means that the body frame tilts to the left of the vehicle when turning to the right, and tilts to the right of the vehicle when turning to the left. In this specification, the turning direction refers to the right or left of the vehicle. In the present invention and embodiments, the term "a lean vehicle turning" means that the lean vehicle is turning while moving forward. Regardless of the vehicle speed, when a lean vehicle is turning, the steering angle in the same direction as the turning direction in the left-right direction of the vehicle is greater than zero.

[0037] In the present invention and the embodiments, when the lean angle in the left-right direction of the vehicle opposite to the turning direction is smaller than a first value, which is a positive value, it means that the lean angle in the left-right direction of the vehicle opposite to the turning direction is a positive value smaller than the first value, zero, or a negative value.

[0038] In the present invention and embodiments, the extremely low speed region includes a vehicle speed range where, when a lean vehicle turns in a balanced state, the body frame tilts in the lateral direction opposite to the turning direction. The high speed region includes a vehicle speed range where, when a lean vehicle turns in a balanced state, the body frame tilts in the lateral direction of the vehicle in the same direction as the turning direction. The extremely low speed region does not need to be continuous with the high speed region. In this specification, the balanced state of a lean vehicle refers to a state where a combination of lean angle, steering angle, and vehicle speed values ​​is such that the lean angle is maintained unchanged when the steering angle and vehicle speed are maintained while driving. Here, the balanced extremely low speed region is defined as the vehicle speed range where, when a lean vehicle turns in a balanced state, the body frame tilts in the lateral direction opposite to the turning direction. Figure 3 shows the combinations of lean angle, steering angle, and vehicle speed in a balanced state of a certain lean vehicle on a three-dimensional curved surface with the lean angle, steering angle, and vehicle speed as the three axes. The region EAV in FIG. 3 indicates the balanced extremely low speed region. The combination of lean angle, steering angle, and vehicle speed in a lean vehicle's balanced state varies depending on the lean vehicle's weight, lean vehicle center of gravity position, wheelbase, caster angle, tire crown radius, and other lean vehicle dimensions, as well as the presence, weight, and center of gravity position of people and objects carried on the lean vehicle. In the present invention and its embodiments, the extremely low speed region is a vehicle speed region in which, when the lean vehicle turns, the body frame tilts in the opposite direction to the turning direction in the vehicle's lateral direction, regardless of the lean angle and steering angle. The upper limit of the extremely low speed region is slightly lower than the upper limit of the balanced extremely low speed region. The upper limit of the extremely low speed region and the upper limit of the balanced extremely low speed region vary depending on the lean vehicle's weight, lean vehicle center of gravity position, wheelbase, caster angle, tire crown radius, and other lean vehicle dimensions, as well as the presence, weight, and center of gravity position of people and objects carried on the lean vehicle. The upper limit of the extremely low speed region and the upper limit of the balanced extremely low speed region are, for example, about 3 to 5 km / h. The upper limit of the extremely low speed region and the lower limit of the balanced extremely low speed region are zero. The lower limit of the balanced extremely low speed region is a negative value when the lean vehicle can travel in the vehicle rearward direction, and is zero when the lean vehicle cannot travel in the vehicle rearward direction.In the present invention and the embodiments, the first very low speed control may be performed over the entire very low speed region, or may be performed over only a part of the very low speed region.

[0039] When a lean vehicle turns in a balanced state, the centrifugal force acting on the lean vehicle and the gravity of the entire lean vehicle are balanced. Note that, in the case where the lean vehicle is carrying at least one of a person and an object, the gravity of the entire lean vehicle here refers to the combined gravity of the lean vehicle and the person and / or object. When a lean vehicle turns in a balanced state at a high vehicle speed, the centrifugal force is large, so the lean angle of the body frame in the same direction as the turning direction in the left-right direction of the vehicle is a positive value. On the other hand, when a lean vehicle turns in a balanced state at a very low vehicle speed, the centrifugal force is small, so the lean angle in the opposite direction to the turning direction in the left-right direction of the vehicle is a positive value. For example, if a lean vehicle has a positive caster angle and a positive trail, when the steering angle to the right of the vehicle is increased from a state in which the lean vehicle is turning right in equilibrium at a very low vehicle speed, the lean angle to the left of the vehicle increases, and the steering angle remains at the increased angle. At this time, the increase in steering angle causes the center of gravity of the part that rotates relative to the body frame about the steering axis to move to the right of the vehicle. However, at the same time, when the contact point of the front wheel moves due to the increase in steering angle, the body frame receives a reaction force from the front wheel, and the center of gravity of the body frame moves to the left of the vehicle. As a result, the center of gravity of the entire lean vehicle moves to the left of the vehicle. Therefore, the lean angle to the left of the vehicle increases. Conversely, when the steering angle to the right of the vehicle is decreased from a state in which the lean vehicle is turning right in equilibrium at a very low vehicle speed, the lean angle to the left of the vehicle decreases, and the steering angle remains at the decreased angle. Furthermore, when a lean vehicle is turning right in a balanced state at a vehicle speed in the extremely low speed range and then the vehicle speed is increased within the extremely low speed range, the centrifugal force increases, causing the lean angle to the left of the vehicle to increase. In this case, the steering angle to the right of the vehicle may decrease slightly. Conversely, when a lean vehicle is turning right in a balanced state at a vehicle speed in the extremely low speed range and then the vehicle speed is decreased within the extremely low speed range, causing the centrifugal force to decrease, causing the lean angle to the left of the vehicle to decrease. In this case, the steering angle to the right of the vehicle may increase slightly.

[0040] In the present invention and embodiments, when the control device controls at least the drive torque based at least on information detected by three detection devices during the first extremely low speed control, the control device may control the drive torque so as to increase vehicle speed. In the present invention and embodiments, when the control device controls at least the steering torque based at least on information detected by three detection devices during the first extremely low speed control, the control device may control the steering torque so as to increase the steering angle in the same direction as the turning direction in the left-right direction of the vehicle. In the present invention and embodiments, when the control device controls at least the drive torque based at least on information detected by three detection devices during the second extremely low speed control, the control device may control the drive torque so as to decrease vehicle speed. In the present invention and embodiments, when the control device controls at least the steering torque based at least on information detected by three detection devices during the second extremely low speed control, the control device may control the steering torque so as to decrease the steering angle in the same direction as the turning direction in the left-right direction of the vehicle.

[0041] When the first extremely low speed control of the present invention and the embodiments is executed while a lean vehicle is being driven by a rider, during the period from when the lean angle in the direction opposite to the turning direction is smaller than a first value until the lean angle in the direction opposite to the turning direction increases, the rider may not perform any of, or may perform at least one of, an operation of an operator to change the vehicle speed, an operation of a handlebar unit to change the steering angle, or a change in the rider's posture to change the lean angle. When the second extremely low speed control of the present invention and the embodiments is executed while a lean vehicle is being driven by a rider, during the period from when the lean angle in the direction opposite to the turning direction is greater than a second value until the lean angle in the direction opposite to the turning direction decreases, the rider may not perform any of, or may perform at least one of, an operation of an operator to change the vehicle speed, an operation of a handlebar unit to change the steering angle, or a change in the rider's posture to change the lean angle.

[0042] In the present invention and the embodiments, "the first value varies depending on at least the steering angle and the vehicle speed at the first time point" means that "the first value varies depending on at least the steering angle and the vehicle speed at the first time point" in the first extremely low speed control performed in a plurality of driving scenes in which at least one of the steering angle and the vehicle speed varies. The first value may be larger the greater the steering angle in the same direction as the turning direction in the left-right direction of the vehicle at the first time point. The first value may be larger the slower the vehicle speed at the first time point. The first value may be smaller than the lean angle in the equilibrium state of the lean vehicle corresponding to the steering angle and the vehicle speed at the first time point. The first value may vary depending not only on the steering angle and the vehicle speed at the first time point but also on at least one of the acceleration in the longitudinal direction of the vehicle and the steering angular velocity at the first time point. In this case, the first value is not necessarily smaller than the lean angle in the equilibrium state of the lean vehicle corresponding to the steering angle and the vehicle speed at the first time point, but may be larger. The first time point may be a time point when the lean angle in the direction opposite to the turning direction in the left-right direction of the vehicle decreases to a value smaller than a first value. The first time point may be a time point when at least the steering angle or the vehicle speed among the lean angle, steering angle, and vehicle speed changes, causing the lean angle in the direction opposite to the turning direction in the left-right direction of the vehicle to become smaller than a first value that varies depending on at least the steering angle and the vehicle speed at the first time point.

[0043] In the present invention and the embodiments, "the second value varies depending on at least the steering angle and the vehicle speed at the second time point" means that "the second value varies depending on at least the steering angle and the vehicle speed at the second time point" in the second extremely low speed control performed in a plurality of driving scenes in which at least one of the steering angle and the vehicle speed varies. The second value may be larger the greater the steering angle in the same direction as the turning direction in the vehicle's left-right direction at the second time point. The second value may be larger the smaller the vehicle speed at the second time point. The second value may be larger than the lean angle in the equilibrium state of the lean vehicle corresponding to the steering angle and the vehicle speed at the second time point. The second value may vary depending not only on the steering angle and the vehicle speed at the second time point, but also on at least one of the acceleration in the vehicle's longitudinal direction and the steering angular velocity at the second time point. In this case, the second value is not necessarily larger than the lean angle in the equilibrium state of the lean vehicle corresponding to the steering angle and the vehicle speed at the second time point, but may be smaller than the lean angle. The second point in time may be a point in time when the lean angle in the direction opposite to the turning direction in the left-right direction of the vehicle increases to a value greater than a second value. The second point in time may be a point in time when at least the steering angle or the vehicle speed among the lean angle, steering angle, and vehicle speed changes, causing the lean angle in the direction opposite to the turning direction in the left-right direction of the vehicle to be greater than a second value that varies depending on at least the steering angle and the vehicle speed at the second point in time.

[0044] Whether or not the first very low speed control has been executed can be determined, for example, by the following method. First, a first test is conducted in which a lean vehicle is turned around a circle at a constant vehicle speed. The first test is conducted multiple times with different combinations of vehicle speed and circle size. This first test identifies a vehicle speed region M in which the lean angle in the left-right direction of the vehicle opposite to the turning direction is a positive value when the lean vehicle is turned around a circle at a constant vehicle speed. Next, a second test is performed in which the lean angle in the direction opposite to the turning direction is decreased while the lean vehicle is turning at a constant vehicle speed and a constant steering angle within vehicle speed region M. For example, the lean angle in the direction opposite to the turning direction may be decreased by applying an external force to the lean vehicle. Then, immediately after the lean angle in the direction opposite to the turning direction is decreased, it is determined whether at least one of a driving torque and a steering torque is applied so as to increase the lean angle in the direction opposite to the turning direction while the lean vehicle is turning at a vehicle speed within vehicle speed region M. If at least one of a driving torque and a steering torque is not applied so as to increase the lean angle in the direction opposite to the turning direction, it can be determined that the first extremely low speed control of the present invention is not being executed. If at least one of a driving torque and a steering torque is applied so as to increase the lean angle in the direction opposite to the turning direction, the second test is performed multiple times by changing test conditions such as the steering angle, lean angle, and vehicle speed. The second test is also performed multiple times under the same test conditions. Note that even if the same test conditions are set, the behavior of the lean vehicle will not necessarily be completely the same. This also applies to the lean vehicle of the present invention. The lower the vehicle speed, the more likely the behavior of the lean vehicle will differ even if the same test conditions are set. Then, it is checked whether there are any test results that satisfy the following discrimination conditions A1 to A3. A1: In any two of the second tests, the minimum values ​​of the lean angle in the direction opposite to the turning direction when the lean angle in the direction opposite to the turning direction is decreased are different, and the steering angle, steering angular velocity, steering angular acceleration, vehicle speed, and acceleration in the longitudinal direction of the vehicle are the same when the lean angle reaches this minimum value, and at least one of the drive torque and steering torque applied to increase the lean angle in the direction opposite to the turning direction is different. However, if the lean vehicle is a lean vehicle driven by a rider, the rider does not operate any of the controls to change the vehicle speed, the handlebar unit to change the steering angle, or change the rider's posture to change the lean angle during the period from when the lean angle reaches the minimum value to when the lean angle in the direction opposite to the turning direction increases. A2: In any two of the second tests, the minimum values ​​of the lean angle in the direction opposite to the turning direction when the lean angle in the direction opposite to the turning direction is reduced are the same, and the lean angular velocity, lean angular acceleration, vehicle speed, and acceleration in the longitudinal direction of the vehicle at the time when the lean angle reaches this minimum value are the same, and the steering angle at the time when the lean angle reaches this minimum value is different, and at least one of the drive torque and steering torque applied to increase the lean angle in the direction opposite to the turning direction is different. However, if the lean vehicle is a lean vehicle driven by a rider, the same condition as discrimination condition A1 is added. A3: In any two of the second tests, the minimum values ​​of the lean angle in the direction opposite to the turning direction when the lean angle in the direction opposite to the turning direction is reduced are the same, and the lean angular velocity, lean angular acceleration, steering angle, steering angular velocity, and steering angular acceleration at the time when the lean angle reaches this minimum value are the same, and the vehicle speed at the time when the lean angle reaches this minimum value is different, and at least one of the drive torque and steering torque applied to increase the lean angle in the direction opposite to the turning direction is different. However, if the lean vehicle is a lean vehicle driven by a rider, the same condition as discrimination condition A1 is added. If there is a test result in which the driving torque satisfies the discrimination conditions A1 to A3, it can be determined that at least the driving torque is controlled based on at least the information detected by the lean angle related information detection device, the steering angle related information detection device, and the wheel speed related information detection device.If there is a test result in which the steering torque satisfies the discrimination conditions A1 to A3, it can be determined that at least the steering torque is controlled based on at least the information detected by the lean angle related information detection device, the steering angle related information detection device, and the wheel speed related information detection device.By using the above procedure, it can be determined whether the first very low speed control has been executed.

[0045] Whether the second extremely low speed control has been executed can be determined by the same determination method as the determination method for whether the first extremely low speed control has been executed. In this case, instead of the second test described above, a test is performed in which the lean angle is increased in the direction opposite to the turning direction from a state in which the lean vehicle is turning at a constant vehicle speed and a constant steering angle within vehicle speed region M.

[0046] In the present invention and the embodiments, the rotation is not limited to a rotation of 360° or more, but also includes a rotation of less than 360°.

[0047] In the present invention and the embodiments, "control based on A" does not mean that the information used for control is limited to only A. "Control based on A" includes cases where control is based on A and information other than A.

[0048] In the present invention and the embodiments, "at least one (one) of a plurality of options" includes all possible combinations of the plurality of options. "At least one (one) of the plurality of options" may be any one of the plurality of options, or may be all of the plurality of options. For example, "at least one of A, B, and C" may be only A, only B, only C, A and B, A and C, B and C, or A, B, and C.

[0049] In the claims, if the number of a certain element is not clearly specified and is expressed in the singular when translated into English, the present invention may have a plurality of this element, or the present invention may have only one of this element.

[0050] In the present invention and embodiments, the words including, comprising, having, and their derivatives are used herein to encompass additional items in addition to the listed items and equivalents thereof.

[0051] In the present invention and the embodiments, the terms "mounted, connected, coupled, and supported" are used broadly. Specifically, they include not only direct mounting, connection, coupling, and support, but also indirect mounting, connection, coupling, and support. Furthermore, connected and coupled are not limited to physical or mechanical connections / couplings. They also include direct or indirect electrical connections / couplings.

[0052] Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification and claims have the same meaning as commonly understood by those skilled in the art to which this invention belongs. Terms, such as those defined in commonly used dictionaries, should be interpreted to have a meaning consistent with the meaning in the context of the relevant technology and this disclosure, and should not be interpreted in an idealized or overly formal sense.

[0053] In the present invention and the embodiments, the term "preferable" is non-exclusive. "Preferable" means "preferably, but not limited to." In this specification, a configuration described as "preferable" at least achieves the above-mentioned effect obtained by the configuration of claim 1. In addition, in this specification, the term "may" is non-exclusive. "may" means "may, but not limited to." In this specification, a configuration described as "may" at least achieves the above-mentioned effect obtained by the configuration of claim 1.

[0054] Before describing embodiments of the present invention in detail, it is to be understood that the invention is not limited to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The present invention is capable of embodiments other than those described below. The present invention is also capable of embodiments incorporating various variations of the embodiments described below. [Effects of the Invention]

[0055] According to the lean vehicle of the present invention, the lean vehicle can be turned smoothly when turning at an extremely low speed. [Brief explanation of the drawings]

[0056] [Figure 1] 1 is a diagram illustrating the configuration of a lean vehicle according to a first embodiment of the present invention. [Figure 2] 10 is a flowchart showing a processing procedure of a control device for a lean vehicle according to a third embodiment of the present invention. [Figure 3] 1 is a graph showing the relationship between lean angle, steering angle, and vehicle speed in a balanced state of a certain lean vehicle. DETAILED DESCRIPTION OF THE INVENTION

[0057] <Direction definition> In the figure, U indicates the upper direction of the lean vehicle, D indicates the lower direction of the lean vehicle, L indicates the left direction of the lean vehicle, R indicates the right direction of the lean vehicle, F indicates the front direction of the lean vehicle, and Re indicates the rear direction of the lean vehicle.

[0058] First Embodiment A first embodiment of the present invention will be described below with reference to FIG. 1. FIG. 1 shows an example of a lean vehicle 1 according to the first embodiment. The lean vehicle 1 according to the first embodiment includes a plurality of wheels 2, a body frame 5, a lean angle-related information detection device 6, a steering angle-related information detection device 7, a wheel speed-related information detection device 8, a torque application device 10, and a control device 9. The plurality of wheels 2 include at least one front wheel 3 and at least one rear wheel 4. The at least one rear wheel 4 is disposed rearward of the at least one front wheel 3 in the longitudinal direction of the vehicle. Note that although the lean vehicle 1 shown in FIG. 1 is a two-wheeled vehicle, the lean vehicle 1 according to the first embodiment is not limited to two-wheeled vehicles. The body frame 5 supports the plurality of wheels 2 rotatably about an axle line X1 and supports the at least one front wheel 3 rotatably about a steering axis line X2. The lean vehicle 1 shown in FIG. 1 has a positive caster angle CA and a positive trail TL, but the lean vehicle 1 according to the first embodiment is not limited to this. The body frame 5 tilts in the same direction as the turning direction in the vehicle's left-right direction when turning at a vehicle speed in at least the high-speed region AV2. The body frame 5 tilts in the opposite direction to the turning direction in the vehicle's left-right direction when turning at a vehicle speed V in an extremely low-speed region AV1 that is lower than the high-speed region AV2. The lean angle-related information detection device 6 detects information related to the lean angle φ, which is the tilt angle of the body frame 5 in the left-right direction of the vehicle with respect to the vehicle's up-down direction. The steering angle-related information detection device 7 detects information related to the steering angle δ, which is the rotation angle of any one of the front wheels 3 about the steering axis X2. The wheel speed-related information detection device 8 detects information related to the wheel speed S, which is the rotation speed of any one of the wheels 2 about the axle X1. The torque application device 10 includes at least one of a driving torque application device 11 and a steering torque application device 12. The driving torque applying device 11 is configured to apply positive and negative driving torques about the axis X1 to at least one of the at least one front wheel 3 and the at least one rear wheel 4.1 is configured to apply drive torque to both at least one front wheel 3 and at least one rear wheel 4, but the drive torque application device 11 of the first embodiment may be configured to apply drive torque only to at least one front wheel 3, or may be configured to apply drive torque only to at least one rear wheel 4. The steering torque application device 12 is configured to apply steering torque about the steering axis X2 to at least one front wheel 3. The control device 9 is configured to control at least one of the drive torque and steering torque applied by the torque application device 10.

[0059] The control device 9 executes the first extremely low speed control when the lean angle φ in the direction opposite to the turning direction in the left-right direction of the vehicle is smaller than a first value, which is a positive value, while the lean vehicle 1 is turning at a vehicle speed V in the extremely low speed region AV1. In the first extremely low speed control, the control device 9 controls at least one of the drive torque and the steering torque based at least on information detected by the lean angle related information detection device 6, the steering angle related information detection device 7, and the wheel speed related information detection device 8 so that the lean angle φ in the direction opposite to the turning direction in the left-right direction of the vehicle increases while the lean vehicle 1 is turning at a vehicle speed V in the extremely low speed region AV1. The lean vehicle 1 of the first embodiment can turn smoothly at extremely low speeds.

[0060] The first time point is defined as the time point at which the lean angle φ in the vehicle left-right direction opposite the turning direction is smaller than a first value before the lean angle φ in the vehicle left-right direction opposite the turning direction is increased by the first very low speed control. It is preferable that the first value differs depending on at least the steering angle δ and the vehicle speed V at the first time point. This allows the lean vehicle 1 to turn more smoothly at very low speeds. The first value may be the same regardless of the steering angle δ and the vehicle speed V at the first time point.

[0061] The control device 9 of the first embodiment may control both the driving torque and the steering torque based on the information detected by the three detectors 6 to 8 during the first extremely low speed control. This allows the lean vehicle 1 to turn more smoothly when turning at an extremely low speed. Furthermore, the control device 9 of the first embodiment may control only the driving torque or only the steering torque based on the information detected by the three detectors 6 to 8 during the first extremely low speed control.

[0062] The control device 9 of the first embodiment may execute the first extremely low speed control when the lean vehicle 1 is traveling autonomously without being driven by a rider. The control device 9 of the first embodiment may execute the first extremely low speed control when the lean vehicle 1 is traveling driven by a rider.

[0063] Second Embodiment A lean vehicle 1 according to a second embodiment of the present invention will be described below. The lean vehicle 1 according to the second embodiment has all of the features of the lean vehicle 1 according to the first embodiment. The control device 9 according to the second embodiment executes second extremely low speed control when the lean angle in the direction opposite to the turning direction in the left-right direction of the vehicle is greater than a second value, which is a positive value, while the lean vehicle 1 is turning at a vehicle speed V in the extremely low speed region AV1. In the second extremely low speed control, the control device 9 controls at least one of the drive torque and the steering torque based at least on information detected by the three detection devices 6 to 8 so that the lean angle φ in the direction opposite to the turning direction in the left-right direction of the vehicle is reduced while the lean vehicle 1 is turning at a vehicle speed V in the extremely low speed region AV1.

[0064] The second time point is defined as the time point at which the lean angle φ in the vehicle's left-right direction opposite the turning direction is greater than the second value before the lean angle φ in the vehicle's left-right direction opposite the turning direction is reduced by the second very low speed control. It is preferable that the second value differs depending on at least the steering angle δ and the vehicle speed V at the second time point. This allows the lean vehicle 1 to turn more smoothly at very low speeds. Note that the second value may be the same regardless of the steering angle δ and the vehicle speed V at the second time point.

[0065] The control device 9 of the second embodiment may control both the driving torque and the steering torque in the second very low speed control based on the information detected by the three detectors 6 to 8. This allows the lean vehicle 1 to turn more smoothly when turning at very low speeds. Furthermore, the control device 9 of the second embodiment may control only the driving torque or only the steering torque in the second very low speed control based on the information detected by the three detectors 6 to 8.

[0066] The control device 9 of the second embodiment may execute the second extremely low speed control when the lean vehicle 1 is traveling autonomously without being driven by a rider. The control device 9 of the second embodiment may execute the second extremely low speed control when the lean vehicle 1 is traveling driven by a rider.

[0067] <Third embodiment> A lean vehicle 1 according to a third embodiment of the present invention will be described below with reference to FIG. 2. The lean vehicle 1 according to the third embodiment has all the features of the lean vehicles 1 according to the first and second embodiments. That is, the control device 9 according to the third embodiment is configured to be able to execute the first extremely low speed control and the second extremely low speed control. Furthermore, the first value differs depending on at least the steering angle δ and the vehicle speed V at the first point in time. Furthermore, the second value differs depending on at least the steering angle δ and the vehicle speed V at the second point in time.

[0068] FIG. 2 is a flowchart showing a processing procedure for the first extremely low speed control and the second extremely low speed control by the control device 9. The flowchart in FIG. 2 starts, for example, when the lean vehicle 1 starts traveling. First, in step S1, the control device 9 determines whether the lean vehicle 1 is turning at a vehicle speed V in an extremely low speed region AV1. Whether the lean vehicle 1 is turning at a vehicle speed V in an extremely low speed region AV1 may be determined based on information detected by the steering angle-related information detection device 7 and the wheel speed-related information detection device 8, for example. If the control device 9 determines that the lean vehicle 1 is turning at a vehicle speed V in an extremely low speed region AV1 (step S1: YES), the control device 9 sets the first value and the second value based at least on the current steering angle and vehicle speed obtained using the steering angle-related information detection device 7 and the wheel speed-related information detection device 8 in step S2. Next, in step S3, the control device 9 determines whether the lean angle φ in the direction opposite to the turning direction in the vehicle left-right direction is smaller than a first value. If the lean angle φ in the direction opposite to the turning direction in the vehicle left-right direction is smaller than the first value (step S3: Yes), the control device 9 proceeds to step S4 and executes the first very low speed control. That is, in step S4, the control device 9 controls at least one of the driving torque and the steering torque based at least on the information detected by the three detection devices 6 to 8 so that the lean angle φ in the direction opposite to the turning direction in the vehicle left-right direction increases while the lean vehicle 1 turns at a vehicle speed in the very low speed region AV1. Thereafter, the control device 9 returns to step S1.

[0069] On the other hand, if the lean angle φ in the direction opposite to the turning direction in the vehicle left-right direction is not smaller than the first value (step S3: No), the control device 9 determines in step S5 whether the lean angle φ in the direction opposite to the turning direction in the vehicle left-right direction is greater than a second value. If the lean angle φ in the direction opposite to the turning direction in the vehicle left-right direction is greater than the second value (step S5: Yes), the control device 9 proceeds to step S6 and executes the second very low speed control. That is, in step S6, the control device 9 controls at least one of the driving torque and the steering torque based at least on the information detected by the three detection devices 6 to 8 so that the lean angle φ in the direction opposite to the turning direction in the vehicle left-right direction decreases while the lean vehicle 1 turns at a vehicle speed in the very low speed region AV1. Thereafter, the control device 9 returns to step S1.

[0070] The processing procedure for the first extremely low speed control and the second extremely low speed control by the control device is not limited to the procedure in the flowchart of FIG. [Explanation of symbols]

[0071] 1: lean vehicle, 2: wheel, 3: front wheel, 4: rear wheel, 5: vehicle frame, 6: lean angle related information detection device, 7: steering angle related information detection device, 8: wheel speed related information detection device, 9: control device, 10: torque application device, 11: driving torque application device, 12: steering torque application device, AV1: very low speed region, AV2: high speed region, S: wheel speed, V: vehicle speed, X1: axle line, X2: steering axis line, δ: steering angle, φ: lean angle

Claims

1. a plurality of wheels including at least one front wheel and at least one rear wheel disposed rearward of the at least one front wheel in a vehicle longitudinal direction; a body frame that supports the plurality of wheels rotatably about an axle line and the at least one front wheel rotatably about a steering axis line, and that tilts in the same direction as the turning direction in the vehicle left-right direction when turning at least at a vehicle speed in a high-speed range; a lean angle-related information detection device that detects information related to a lean angle, which is an inclination angle of the body frame in the left-right direction of the vehicle with respect to the up-down direction of the vehicle; a steering angle-related information detection device that detects information related to a steering angle, which is a rotation angle of any one of the front wheels about the steering axis; a wheel speed related information detection device that detects information related to a wheel speed, which is a rotation speed of any one of the wheels about the axle line; a torque applying device including at least one of a driving torque applying device configured to apply positive and negative driving torque about the axle to at least one of the at least one front wheel and the at least one rear wheel, and a steering torque applying device configured to apply a steering torque about the steering axis to the at least one front wheel; a control device configured to control at least one of the driving torque and the steering torque applied by the torque application device; A lean vehicle comprising: the vehicle body frame tilts in the vehicle left-right direction in a direction opposite to the turning direction when the vehicle turns at a vehicle speed in an extremely low speed range that is lower than the high speed range, The control device When the lean vehicle is turning at the vehicle speed in the extremely low speed region, the lean angle in the left-right direction of the vehicle opposite to the turning direction is smaller than a first value which is a positive value, A lean vehicle characterized in that, while the lean vehicle is turning at the vehicle speed in the extremely low speed region, a first extremely low speed control is executed to control at least one of the drive torque and the steering torque based at least on information detected by the lean angle related information detection device, the steering angle related information detection device, and the wheel speed related information detection device so that the lean angle in the direction opposite to the turning direction in the left-right direction of the vehicle increases.

2. The control device, in the first very low speed control, At a first time point while the lean vehicle is turning at the vehicle speed in the extremely low speed region, the lean angle in the left-right direction of the vehicle opposite to the turning direction is smaller than the first value. while the lean vehicle is turning at the vehicle speed in the extremely low speed region, at least one of the drive torque and the steering torque is controlled based at least on information detected by the lean angle related information detection device, the steering angle related information detection device, and the wheel speed related information detection device so that the lean angle in the vehicle left-right direction opposite to the turning direction increases; 2. The lean vehicle according to claim 1, wherein the first value varies depending on at least the steering angle and the vehicle speed at the first point in time.

3. The control device When the lean vehicle is turning at the vehicle speed in the extremely low speed region, the lean angle in the left-right direction of the vehicle opposite to the turning direction is greater than a second value which is a positive value.

3. The lean vehicle according to claim 1, wherein a second extremely low speed control is executed to control at least one of the drive torque and the steering torque based at least on information detected by the lean angle related information detection device, the steering angle related information detection device, and the wheel speed related information detection device so that the lean angle in the direction opposite to the turning direction in the left-right direction of the vehicle decreases while the lean vehicle is turning at the vehicle speed in the extremely low speed region.

4. In the second very low speed control, the control device At a second time point while the lean vehicle is turning at the vehicle speed in the extremely low speed region, the lean angle in the left-right direction of the vehicle opposite to the turning direction is greater than the second value. while the lean vehicle is turning at the vehicle speed in the extremely low speed region, at least one of the drive torque and the steering torque is controlled based at least on information detected by the lean angle related information detection device, the steering angle related information detection device, and the wheel speed related information detection device so that the lean angle in the vehicle left-right direction opposite to the turning direction is reduced; 4. The lean vehicle according to claim 3, wherein the second value varies depending on at least the steering angle and the vehicle speed at the second point in time.

5. the torque imparting device includes at least the driving torque imparting device of the driving torque imparting device and the steering torque imparting device, In the first very low speed control, the control device When the lean vehicle is turning at the vehicle speed in the extremely low speed region, the lean angle in the left-right direction of the vehicle opposite to the turning direction is smaller than the first value, which is a positive value.

3. A lean vehicle as described in claim 1 or 2, characterized in that at least the driving torque and the steering torque are controlled based at least on information detected by the lean angle related information detection device, the steering angle related information detection device, and the wheel speed related information detection device so that the lean angle in the direction opposite to the turning direction in the left-right direction of the vehicle increases while the lean vehicle is turning at the vehicle speed in the extremely low speed region.

6. 3. The lean vehicle according to claim 1, wherein the control device executes the first extremely low speed control in at least one of a state in which the lean vehicle is autonomously traveling without being driven by a rider and a state in which the lean vehicle is driven by a rider.

Images