Lean vehicles

Abstract

The present invention provides a lean-type vehicle that can further suppress the influence of the brake system's operation on the rider's riding posture while holding the handlebars in a lean position. [Solution] A lean vehicle comprises a body, rear wheels, front forks, front wheels, handlebars, a power source, an automatic transmission, a front brake system, a rear brake system, a brake drive system, and a preceding vehicle following control system. After initiating deceleration control of the lean vehicle, the preceding vehicle following control system causes the automatic transmission to downshift to reduce the amount of handlebar sinking caused by the operation of the front brake system. The automatic transmission is a device that changes the rotational speed ratio of the rear wheels. If the rotational speed of the output shaft of the power source does not change, the rotational speed of the rear wheels decreases due to the downshift operation of the automatic transmission. Also, the torque of the power source as seen from the rear wheels increases. Therefore, the braking force of the rear wheels due to the resistance of the power source increases due to the downshift operation.

Description

Technical Field

[0001] The present invention relates to a lean vehicle.

Background Art

[0002] For example, Patent Document 1 shows a lean vehicle equipped with a braking device. In this braking device, when it is determined that there may be an obstacle ahead, the automatic brake control unit pressurizes the rear brake to brake the rear wheels and simultaneously pressurizes the front brake to a predetermined pressure. When the anti-lock operation is performed to avoid locking of the rear wheels, the automatic brake control unit pressurizes the front brake at a predetermined pressure to brake the front wheels.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to further suppress the influence of the operation of the braking device on the riding posture of a rider holding a handlebar in a lean state in the following control of a preceding vehicle by a lean vehicle.

Means for Solving the Problems

[0005] The inventors of the present invention studied the influence of the operation of the braking device on the riding posture of a rider in the following control of a preceding vehicle by a lean vehicle.

[0006] A rider of a lean vehicle sits astride the seat of the lean vehicle and maintains the riding posture by holding the handlebar. Therefore, the position of the handlebar affects the riding posture of the rider. Further, the handlebar is held by the rider and functions as a steering input member to which a steering force is input from the rider. In a lean vehicle, the handlebars are fixed to a front fork that is rotatably supported on the vehicle body. The front wheel is supported by the front fork. The front fork is mounted with a caster angle to the vertical direction when the vehicle body is upright. In other words, the axis of rotation of the front wheel is positioned in front of the support position of the front fork relative to the vehicle body in the longitudinal direction. The front fork is also equipped with a shock absorber that expands and contracts in the axial direction of rotation of the front fork, i.e., in the extension direction of the front fork. Because the front fork is mounted on the vehicle body with a caster angle, an autonomous steering force is generated in response to the turning of the lean vehicle, which tilts to the left when turning left and to the right when turning right, while unintentional fluctuations are suppressed. In a leaned vehicle, when the front brake is applied, the shock absorber of the front fork, which has a caster angle, compresses in accordance with the resistance of the front wheel against the ground. As the shock absorber compresses in the direction of extension of the front fork, the handlebars, which are fixed to the front fork, move relative to the front wheel as the shock absorber compresses. As a result, the handlebars sink downward. This sinking of the handlebars, which are held by the rider's hands, changes the rider's riding posture when holding the handlebars, for example in a leaned state, and also changes the position from which the rider applies steering force to the handlebars.

[0007] The inventors further investigated the sinking of the handlebars. As a result, they found that the resistance of the drive source to the rear wheels, which are the drive wheels of a lean vehicle, can be effectively utilized, known as engine braking. The action of engine braking is braking of the rear wheels using the mechanical resistance of the drive source (see reference: https: / / www.goo-net.com / magazine / carmaintenance / parts / 213384 / ). Engine braking is often used to supplement brakes that use friction force. The inventors considered that in a lean vehicle equipped with an automatic transmission, after deceleration control is started, the automatic transmission should perform a downshift operation to reduce the amount of handlebar sinking caused by the operation of the front brake device. The downshift operation of the automatic transmission increases the braking force on the rear wheels due to the resistance of the power source. The braking force of the rear wheel increases due to the resistance of the power source, which in turn reduces the braking force of the front wheel. As a result of the increased braking force of the rear wheel and the decreased braking force of the front wheel, the amount of handlebar sinking is suppressed. Therefore, the effect on the rider's riding posture when holding the handlebars in a leaned position is suppressed. This invention was completed based on the above findings.

[0008] To achieve the above objectives, according to one aspect of the present invention, a lean vehicle comprises the following configuration.

[0009] (1) A lean vehicle that tilts to the left during a left turn and to the right during a right turn, The lean vehicle is, The car body and, The rear wheels, which are drive wheels supported by the aforementioned vehicle body, A front fork is rotatably supported on the vehicle body so as to have a caster angle with respect to the vertical direction of the vehicle body, and is equipped with a shock absorber that extends and retracts in the axial direction of rotation, The front wheel is supported by the aforementioned front fork, A handlebar fixed to the front fork and held by the rider of the lean vehicle, A power source having an output shaft, which outputs power to drive the lean vehicle as rotation of the output shaft, An automatic transmission that changes the speed ratio between the rotation output from the output shaft and the rotation of the rear wheel by shifting up or down, A front brake device for braking the aforementioned front wheel, A rear brake device for braking the aforementioned rear wheel, A brake drive device that operates the front brake device and the rear brake device, A preceding vehicle following control device controls the power source, the brake drive device, and the automatic transmission device to control the acceleration or deceleration of the lean vehicle so that the lean vehicle follows the vehicle in front of it, Equipped with, After the preceding vehicle following control device starts deceleration control of the leaning vehicle, it causes the automatic transmission to perform a downshift operation to reduce the amount of handlebar sinking caused by the operation of the front brake device.

[0010] The lean vehicle described in (1) comprises a body, a rear wheel, a front fork, a front wheel, handlebars, a power source, an automatic transmission, a front brake system, a rear brake system, a brake drive system, and a preceding vehicle following control system. The rear wheel is a drive wheel and is supported by the body. The front fork is rotatably supported by the body. The front fork is supported by the body so as to have a caster angle with respect to the vertical direction of the body. The vertical direction is perpendicular to the ground when the body is upright. A shock absorber is provided on the front fork. The shock absorber extends and retracts in the axial direction of rotation of the front fork. The handlebars are fixed to the front fork and held by the rider's hands. The power source has an output shaft. The power source outputs power to drive the lean vehicle. The power source outputs power as rotation of the output shaft. The automatic transmission uses power to perform upshifting or downshifting operations. The automatic transmission changes the speed ratio between the rotation output from the output shaft and the rotation of the rear wheels through upshifting or downshifting. The front brake system is for braking the front wheels. The rear brake system is for braking the rear wheels. The brake drive system operates the front brake system and the rear brake system. The adaptive cruise control system controls the power source, brake drive system, and automatic transmission. As a result, the adaptive cruise control system controls the driving speed of the lean vehicle so that the lean vehicle follows the vehicle in front. The adaptive cruise control system initiates deceleration control of the leaning vehicle and then causes the automatic transmission to downshift to reduce the amount of handlebar sink caused by the operation of the front brakes. The automatic transmission is a device that changes the rotational speed ratio of the rear wheels. The downshift operation of the automatic transmission increases the rotational speed of the power source. As the rotational speed of the power source increases, the lost torque of the power source increases, and the resistance on the output shaft of the power source becomes stronger. In addition, the reduction ratio increases due to the downshift operation, which increases the braking force due to the resistance of the power source on the rear wheels. This braking force on the rear wheels is, for example, engine braking. The deceleration of a leaning vehicle corresponds to the sum of the braking forces of the front and rear wheels. Therefore, by increasing the braking force of the rear wheels through a downshift operation, the braking force of the front wheels can be reduced. In this way, the adaptive cruise control system causes the automatic transmission to perform a downshift operation to reduce the amount of handlebar sinking caused by the operation of the front brakes. Since the amount of handlebar sinking is suppressed, the impact on the rider's riding posture when holding the handlebars in a leaned state is reduced.

[0011] According to one aspect of the present invention, a lean vehicle can employ the following configuration. (2) A lean vehicle of (1), After the preceding vehicle following control device starts deceleration control of the leaning vehicle, if the front brake device is operating, it causes the automatic transmission to perform a downshift operation to reduce the amount of handlebar sinking caused by the operation of the front brake device.

[0012] According to (2), after deceleration control is initiated, the automatic transmission shifts down if the front brake is engaged. Therefore, when the front brake is engaged, the braking force of the rear wheel increases due to the downshift, thereby reducing the braking force of the front wheel. When the front brake is engaged, the braking force of the rear wheel increases and the braking force of the front wheel decreases, which suppresses the amount of handlebar sinking, thus reducing the impact on the rider's riding posture.

[0013] According to one aspect of the present invention, a lean vehicle can employ the following configuration. (3) A lean vehicle of (2), The preceding vehicle following control device causes the automatic transmission to perform a downshift operation based on the amount of operation of the front brake device, in order to reduce the amount of sinking of the handlebars caused by the operation of the front brake device.

[0014] According to (3), the operation amount of the front brake device decreases along with the downshift operation based on the operation amount of the front brake device. Therefore, the braking force of the rear wheels increases and the braking force of the front wheels decreases, resulting in the suppression of the amount of depression of the handlebar. As a result, the influence on the rider's riding posture is suppressed. The operation amount of the front brake device is, for example, the pressure of the brake caliper when the front brake device has a brake caliper. The operation amount of the front brake device is not particularly limited, and may be, for example, the pressure of the working fluid supplied by the brake drive device to the front brake device. The pressure of the brake caliper or the pressure of the working fluid can be detected by, for example, a pressure sensor.

[0015] According to one aspect of the present invention, a lean vehicle can adopt the following configuration. (4) The lean vehicle according to (2) or (3), The preceding vehicle following control device acquires a target acceleration, controls the acceleration or deceleration of the lean vehicle based on the target acceleration, and causes the automatic transmission to perform a downshift operation so as to reduce the amount of depression of the handlebar caused by the operation of the front brake device based on the target acceleration.

[0016] (4) According to (4), the operation amount of the front brake device decreases along with the downshift operation based on the target acceleration. Therefore, the braking force of the rear wheels increases and the braking force of the front wheels decreases, resulting in the suppression of the amount of depression of the handlebar. As a result, the influence on the rider's riding posture is suppressed. Note that acceleration is a concept including a positive value indicating acceleration toward the front of the lean vehicle and a negative value indicating deceleration. However, the method of displaying the value is not limited to this.

[0017] According to one aspect of the present invention, a lean vehicle can adopt the following configuration. (5) The lean vehicle according to any one of (2) to (4), The preceding vehicle following control device detects the actual acceleration of the leaning vehicle, controls the acceleration or deceleration of the leaning vehicle based on the actual acceleration, and causes the automatic transmission to perform a downshift operation so as to reduce the amount of depression of the handlebar caused by the operation of the front brake device based on the actual acceleration.

[0018] (5) According to this, with the downshift operation based on the actual acceleration of the leaning vehicle, the operation amount of the front brake device decreases. Therefore, as a result of the rear wheel braking force increasing and the front wheel braking force decreasing, the amount of depression of the handlebar is suppressed. As a result, the influence on the rider's riding posture is suppressed.

[0019] According to one aspect of the present invention, the leaning vehicle can adopt the following configuration. (6) A leaning vehicle according to any one of (2) to (5), The preceding vehicle following control device acquires a front brake control value for operating the front brake device in the brake drive device, controls the acceleration or deceleration of the leaning vehicle based on the front brake control value, and based on the front brake control value, causes the automatic transmission to perform a downshift operation so as to reduce the amount of depression of the handlebar caused by the operation of the front brake device.

[0020] (6) According to this, since the downshift operation is performed based on the front brake control value, the downshift operation is performed so as to reduce the amount of depression of the handlebar without detecting the actual operation state of the front brake. Therefore, the amount of depression of the handlebar can be suppressed with a small number of parts.

[0021] According to one aspect of the present invention, the leaning vehicle can adopt the following configuration. (7) A leaning vehicle according to (1), The preceding vehicle following control device acquires a target acceleration as a control target for acceleration or deceleration of the lean vehicle, and when the target acceleration is within the planned operating range for the operation of the front brake device, it causes the automatic transmission to perform a downshift operation to reduce the amount of handlebar sinking caused by the operation of the front brake device.

[0022] According to (7), a downshift is performed when the front brake is not engaged and the target acceleration is within the planned range for the front brake to engage. By performing a downshift before the front brake actually engages, the reduction in the amount of handlebar dip when the front brake engages is further suppressed. As a result, the impact on the rider's riding posture is reduced.

[0023] According to one aspect of the present invention, a lean vehicle can employ the following configuration. (8) A lean vehicle of (7), After the preceding vehicle following control device starts deceleration control of the leaning vehicle, if the rear brake device is operating, it forces the automatic transmission to perform a downshift operation to reduce the amount of handlebar sinking caused by the operation of the front brake device.

[0024] When decelerating using the aforementioned adaptive cruise control system, the rear brake often operates before the front brake. According to (8), since the downshift operation is performed when the rear brake is operating, there is a high probability that the downshift operation will occur before the front brake. Therefore, the braking force of the front wheel when the front brake is applied is further reduced. As a result, the amount of handlebar sinking is suppressed. As a result, the impact on the rider's riding posture is suppressed.

[0025] According to one aspect of the present invention, a lean vehicle can employ the following configuration. (9) A lean vehicle of (8), After the preceding vehicle following control device starts deceleration control of the lean vehicle, it causes the automatic transmission to perform a downshift operation based on the amount of operation of the rear brake device to reduce the amount of handlebar sinking caused by the operation of the front brake device.

[0026] According to (9), the amount of movement of the front brake decreases as a downshift operation occurs based on the amount of movement of the rear brake. Consequently, the braking force of the rear wheel increases and the braking force of the front wheel decreases, resulting in a suppression of the amount of handlebar sinking. As a result, the impact on the rider's riding posture is reduced. The amount of movement of the rear brake system is, for example, the pressure of the brake caliper if the rear brake system has a brake caliper. Alternatively, the amount of movement of the rear brake system is, for example, the pressure of the hydraulic fluid supplied to the rear brake system by the brake drive unit. The pressure of the brake caliper or the hydraulic fluid can be detected, for example, by a pressure sensor.

[0027] According to one aspect of the present invention, a lean vehicle can employ the following configuration. (10) A lean vehicle of (8) or (9), The brake drive system further includes a brake lamp that illuminates when the front brake system or the rear brake system is operated, When the brake lights illuminate, the preceding vehicle following control device causes the automatic transmission to perform a downshift operation to reduce the amount of handlebar depression caused by the operation of the front brake device.

[0028] According to (10), in adaptive cruise control, the brake lights illuminate when the front brakes or rear brakes are activated. By performing a downshift operation in response to the illumination of the brake lights, the amount of handlebar depression is suppressed with fewer parts than would be required for pressure detection. As a result, the impact on the rider's riding posture is suppressed with fewer parts.

[0029] According to one aspect of the present invention, a lean vehicle can employ the following configuration. (11) A lean vehicle of any one of (8) to (9), The preceding vehicle following control device acquires a rear brake control value for the brake drive unit to operate the rear brake unit, controls the acceleration or deceleration of the lean vehicle based on the rear brake control value, and causes the automatic transmission to perform a downshift operation based on the rear brake control value to reduce the amount of handlebar sinking caused by the operation of the front brake unit.

[0030] According to (11), since the downshift operation is performed based on the rear brake control value, the amount of operation of the front brake device decreases due to the downshift operation without detecting the actual operating state of the rear brake. Consequently, the braking force of the rear wheel increases and the braking force of the front wheel decreases, resulting in a suppression of the amount of handlebar sinking. As a result, the impact on the rider's riding posture is suppressed. The rear brake control value is, for example, the target value of the rear brake caliper pressure calculated by the adaptive cruise control system, or a flag indicating that pressure is being applied to the rear brake system.

[0031] According to one aspect of the present invention, a lean vehicle can employ the following configuration. (12) A lean vehicle of any one of (8) to (11), The preceding vehicle following control device obtains a following acceleration for following the preceding vehicle based on its relationship with the preceding vehicle, obtains a target acceleration by removing the abrupt change component from the following acceleration, controls the acceleration or deceleration of the lean vehicle based on the target acceleration, and causes the automatic transmission to perform a downshift operation based on the following acceleration to reduce the amount of handlebar sinking caused by the operation of the front brake device.

[0032] According to (12), the acceleration or deceleration of the lean vehicle is controlled based on the target acceleration obtained by removing the abrupt change component from the tracking acceleration. As a result, abrupt behavior is suppressed, and by using the tracking acceleration before the abrupt change component is removed for downshift operations that reduce the amount of handlebar sink, the amount of handlebar sink can be suppressed earlier in response to the operation of the front brake device. As a result, the impact on the rider's riding posture is suppressed earlier.

[0033] A lean vehicle is a vehicle configured to turn in a lean position, leaning toward the center of the curve. A lean vehicle is a type of saddle-type vehicle configured for the rider to ride in a straddling position. A lean vehicle has a power source. Lean vehicles include scooter-type, moped-type, off-road-type, and on-road-type motorcycles. A lean vehicle may have at least one front wheel and at least one rear wheel. A lean vehicle is not limited to motorcycles and may be a three-wheeled vehicle with either a front or rear wheel consisting of a pair of left and right wheels, or a four-wheeled vehicle with both a front and rear wheel consisting of a pair of left and right wheels.

[0034] The power source is, for example, an internal combustion engine. However, the power source is not particularly limited, and may also be, for example, an electric motor.

[0035] An automatic transmission is, for example, a stepped transmission that switches the gear ratio by selecting from multiple combinations of gears. An automatic transmission changes the gear combination by driving, for example, an electric actuator or a hydraulic actuator. However, the automatic transmission is not particularly limited and may be, for example, a continuously variable transmission (CVT).

[0036] A preceding vehicle following control device is a device that controls the driving speed of a lean vehicle so that the lean vehicle follows the vehicle in front of it, and is referred to as, for example, an adaptive cruise control device. A part of the preceding vehicle following control device may be provided separately from other parts. For example, at least a part of the preceding vehicle following control device that determines whether it is following a preceding vehicle, the part that controls the power source, the part that controls the brake drive device, and the part that controls the automatic transmission may be provided separately from the rest of the device. For example, the unit that determines whether it is following a preceding vehicle and the unit that controls the automatic transmission may be located in different places on the lean vehicle and function as a preceding vehicle following control device by communicating with each other. Alternatively, the part that determines whether it is following a preceding vehicle and the part that controls the automatic transmission may be integrated into a single unit.

[0037] The preceding vehicle following control device is, for example, a different device from the power source control device. However, the preceding vehicle following control device is not particularly limited and may, for example, be integrated with the power source control device. The preceding vehicle following control device may also be a different device from, for example, the brake drive control unit or the automatic transmission control unit. However, the preceding vehicle following control device may be integrated with the brake drive control unit or the automatic transmission control unit.

[0038] The timing of the downshift operation controlled by the adaptive cruise control system does not need to be simultaneous with the start of the front brake system's operation; for example, it may occur before the front brake system's operation. This is because the increase in rear wheel braking force associated with the downshift operation has little effect on the handlebar sinking. Alternatively, the downshift operation may occur immediately after the start of the front brake system's operation, before the effect of the handlebar sinking fully manifests.

[0039] The technical terms used herein are intended to define only specific embodiments and are not intended to limit the invention. The term "and / or" as used herein includes any or all combination of one or more related enumerated components. Where used herein, the use of the terms "including," "comprising," or "having" and their variations identifies the presence of described features, processes, operations, elements, components and / or equivalents thereof, but may include one or more of the steps, operations, elements, components and / or groups thereof. Where used herein, the terms "attached," "connected," "joined" and / or equivalents are used broadly and include both direct and indirect attachment, connection and joining. Furthermore, "connected" and "joined" are not limited to physical or mechanical connection or joining, but may include direct or indirect electrical connection or joining. Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as generally understood by those skilled in the art to whom the invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant technology and this disclosure, and not as ideal or overly formal unless expressly defined herein. It is understood that numerous technologies and processes are disclosed in this description of the invention. Each of these has its own individual benefit, and each may be used in conjunction with one or more, or possibly all, of the other disclosed technologies. Therefore, for clarity, this description refrains from unnecessarily repeating all possible combinations of individual steps. Nevertheless, the specification and claims should be read with the understanding that all such combinations are within the scope of the invention and claims. This specification describes a new lean vehicle. For illustrative purposes, numerous specific details are given in the following description to provide a complete understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be carried out without these specific details. This disclosure should be considered illustrative of the invention and is not intended to limit the invention to the specific embodiments shown by the following drawings or description. [Effects of the Invention]

[0040] According to the present invention, in the control of a leaning vehicle following a preceding vehicle, the influence of the operation of the braking device on the rider's riding posture can be further suppressed. [Brief explanation of the drawing]

[0041] [Figure 1] This is a block diagram illustrating the schematic configuration of a lean vehicle according to an embodiment of the present invention. [Figure 2] Figure 1 is a flowchart illustrating the operation of the adaptive cruise control system in a leaned vehicle. [Figure 3] This graph schematically shows the operating conditions of each device in the first embodiment. [Figure 4] This is a time chart showing an example of operation in the embodiment. [Figure 5] This graph shows the characteristics of the gear ratios in a modified example of the fourth embodiment. [Figure 6] This graph schematically shows the operating conditions of each device in the sixth embodiment. [Figure 7] This is a time chart showing an example of operation in the sixth embodiment. [Figure 8] This graph schematically shows the operating conditions of each device in the 10th embodiment. [Figure 9] This is a time chart showing an example of operation in the 10th embodiment. [Modes for carrying out the invention]

[0042] [First Embodiment] Figure 1 is a block diagram illustrating the schematic configuration of a lean vehicle according to an embodiment of the present invention.

[0043] The lean vehicle 1 shown in Figure 1 is a vehicle that turns in a lean posture, leaning toward the center of the curve. That is, the lean vehicle 1 tilts to the left when turning left and tilts to the right when turning right. The lean vehicle 1 comprises a body 11, rear wheels 12, front forks 13, front wheels 14, handlebars 15, power source 16, automatic transmission 17, front brake device 18, rear brake device 19, brake drive device 21, and preceding vehicle following control device 22. In Figure 1, arrow F indicates the forward direction of lean vehicle 1. The forward direction is the direction in which lean vehicle 1 travels. Arrow B indicates the backward direction. Arrows F and B represent the longitudinal direction FB of lean vehicle 1. Arrow U indicates the upward direction. Arrow D indicates the downward direction. Arrows U and D represent the vertical direction UD of lean vehicle 1. The upward direction U, downward direction D, and vertical direction UD are parallel to the vertical direction when lean vehicle 1 is in an upright position.

[0044] The rear wheel 12 is supported by the vehicle body 11. The rear wheel 12 is a drive wheel. The front fork 13 is rotatably supported by the vehicle body 11. The front fork 13 is supported by the vehicle body 11 such that it has a caster angle CA with respect to the vertical direction UD of the vehicle body 11. More specifically, the direction of the axis of rotation 13a of the front fork 13 has a caster angle CA with respect to the vertical direction UD. The vertical direction UD is the direction perpendicular to the ground when the vehicle body 11 is upright. The front wheel 14 is supported at the lower end of the front fork 13. The front wheel 14 is rotatably supported by the front fork 13.

[0045] The handlebars 15 are fixed to the upper end of the front forks 13. The handlebars 15 are held by the hands H of the rider R who is riding the lean vehicle 1. Steering force is input to the handlebars 15 via the hands H of the rider R. The front forks 13 are provided with a shock absorber 23. The shock absorber 23 is located between the handlebars 15 and the front wheel 14. More specifically, the shock absorber 23 is located on the front forks 13 between the mounting position of the handlebars 15 and the mounting position of the front wheel 14. The shock absorber 23 expands and contracts in the direction of the axis of rotation 13a of the front forks 13, i.e., in the axial direction, by elastic deformation.

[0046] The power source 16 is mounted on the vehicle body 11. The power source 16 outputs power to drive the lean vehicle 1. The power source 16 is, for example, an internal combustion engine. The power source 16 is equipped with a power source control device 26. The power source control device 26 controls the operation of the power source 16. The power source control device 26 is, for example, an engine control unit, and controls the output of the power source 16 by, for example, controlling the opening degree of the throttle valve and the amount of fuel supplied to the internal combustion engine, which is the power source 16. The power source 16 has an output shaft 16a. The power source 16 outputs power as rotation of the output shaft 16a. The output shaft 16a is, for example, a crankshaft. The automatic transmission 17 changes the speed ratio between the rotation output from the output shaft 16a and the rotation of the rear wheels 12.

[0047] The automatic transmission 17 is equipped with a shift actuator 27. The shift actuator 27 is, for example, an electric actuator or a hydraulic actuator. The automatic transmission 17 changes the speed ratio by performing an upshift or downshift operation using the power of the shift actuator 27. A clutch (not shown) is also provided between the power source 16 and the automatic transmission 17.

[0048] The front brake system 18 is a device that brakes the front wheels 14. The rear brake system 19 is a device that brakes the rear wheels 12. The brake drive system 21 operates the front brake system 18 and the rear brake system 19. The brake drive system 21 can operate the front brake system 18 and the rear brake system 19 independently of each other. The brake drive system 21 is equipped with an actuator and valve (not shown) that control the pressure of the hydraulic fluid. The brake drive system 21 operates the front brake system 18 and the rear brake system 19 by applying pressure to each of them via the hydraulic fluid. The brake drive system 21 is also equipped with a sensor (not shown) that detects the pressure of the hydraulic fluid.

[0049] The preceding vehicle following control device 22 controls the power source 16, the brake drive unit 21, and the automatic transmission unit 17. More specifically, the preceding vehicle following control device 22 controls the operation of the power source 16 via the power source control device 26 and the operation of the automatic transmission unit 17 via the transmission actuator 27. The preceding vehicle following control device 22 controls the power source 16, the brake drive unit 21, and the automatic transmission unit 17 so that the lean vehicle 1 travels at a target acceleration and speed, based on the distance to the preceding vehicle detected by, for example, a radar distance sensor (not shown). In this way, the preceding vehicle following control device 22 controls the travel speed of the lean vehicle 1 so that the lean vehicle 1 follows the preceding vehicle. However, the means for acquiring the status of the preceding vehicle is not limited to detection by a radar distance sensor, but may also be, for example, image recognition using images captured by a camera, or analysis using communication with a device installed in the preceding vehicle. More specifically, the preceding vehicle following control device 22 consists of a computer equipped with a memory (not shown) for storing programs and data, and a central processing unit that reads and executes programs from the memory.

[0050] When the preceding vehicle following control device 22 decelerates the leaning vehicle 1 that is in motion, it controls at least one of the power source 16, the front brake device 18, the rear brake device 19, and the automatic transmission 17. When the front brake system 18 operates while the leaned vehicle 1 is in motion, for example, and brakes the front wheel 14, a braking force in the longitudinal direction FB acts between the front wheel 14 and the ground. The front fork 13, which is provided between the front wheel 14 and the vehicle body 11, is mounted with a caster angle CA with respect to the vertical direction UD. As a result, the shock absorber 23 of the front fork 13 compresses in response to the braking force in the longitudinal direction FB. The handlebar 15, which is fixed to the upper end of the front fork 13, moves relative to the front wheel 14 in the fork direction G shown in the figure, as the shock absorber 23 compresses. As a result, the height of the handlebar 15 relative to the front wheel 14 decreases. In other words, the handlebar 15 sinks downward D in the vertical direction UD. As the handlebar 15, which is held by the rider R with their hands H, sinks, the riding posture of the rider R holding the handlebar 15 in the leaned state changes, and the position from which the rider R applies steering force to the handlebar 15 changes.

[0051] After the preceding vehicle following control device 22 starts deceleration control of the leaning vehicle 1, it causes the automatic transmission 17 to perform a downshift operation to reduce the amount of sinking of the handlebars 15 caused by the operation of the front brake device 18. The amount of deceleration of the lean vehicle 1 depends on the sum of the braking force of the front wheels 14 and the braking force of the rear wheels 12. Here, the braking force of the front wheels 14 is the braking force of the front brake device 18. The braking force of the rear wheels 12 is the sum of the braking force of the rear brake device 19 and the rotational resistance torque of the output shaft 16a of the power source 16. The rotational resistance torque of the output shaft 16a of the power source 16 is the engine brake. The automatic transmission 17 is a device that changes the speed ratio of the rotation of the rear wheels 12. Depending on the gear ratio in the automatic transmission 17, the rotational resistance torque transmitted to the rear wheels 12 differs. The downshift operation of the automatic transmission 17 increases the rotational resistance torque of the output shaft 16a transmitted to the rear wheels 12. As the braking force of the rear wheels 12 increases due to the downshifting operation, the braking force of the front wheels 14 can be reduced while maintaining the deceleration of the lean vehicle 1. In this way, the preceding vehicle following control device 22 causes the automatic transmission 17 to perform a downshift operation to reduce the amount of sinking of the handlebars 15 caused by the operation of the front brake device 18. As a result of suppressing the amount of sinking of the handlebars 15, the effect on the riding posture of the rider R who holds the handlebars 15 in a leaned position is reduced.

[0052] The lean vehicle 1 is also equipped with a speed sensor 24 and a brake light 25. The speed sensor 24 detects the travel speed of the lean vehicle 1. The brake light 25 is illuminated when at least one of the front brake device 18 and the rear brake device 19 is operating.

[0053] Figure 2 is a flowchart illustrating the operation of the adaptive cruise control system in the lean vehicle shown in Figure 1.

[0054] The preceding vehicle following control device 22 performs preceding vehicle following control by executing a preceding vehicle following control program stored in a memory (not shown).

[0055] In the preceding vehicle following control, the preceding vehicle following control device 22 performs preceding vehicle status detection (S10). More specifically, the preceding vehicle following control device 22 acquires inter-vehicle information indicating the relationship between the preceding vehicle and the leaning vehicle 1. The inter-vehicle information includes, for example, the distance between the preceding vehicle and the leaning vehicle 1, and the speed of the preceding vehicle. The speed of the preceding vehicle is either the relative speed to the leaning vehicle 1, or the driving speed of the preceding vehicle itself. For example, the preceding vehicle following control device 22 acquires the speed of the preceding vehicle based on the distance to the preceding vehicle detected by a radar device (not shown), and the change in distance over time. Based on the inter-vehicle information, the preceding vehicle following control device 22 acquires the target acceleration of the leaning vehicle 1 as a control target for acceleration or deceleration of the leaning vehicle 1.

[0056] The preceding vehicle following control device 22 performs acceleration control (S12, S13) if the target acceleration indicates an acceleration request (Yes in S11). Here, the target acceleration indicating an acceleration request means, for example, that the acquired target acceleration indicates acceleration in the direction of travel of the lean vehicle 1. The target acceleration indicating an acceleration request means, for example, that the acquired target acceleration is a positive value. In acceleration control, the preceding vehicle following control device 22 increases the opening of the throttle valve of the engine, which is the power source 16 (S12). The preceding vehicle following control device 22 also increases the amount of fuel supplied. The lean vehicle 1 accelerates due to the acceleration control. The preceding vehicle following control device 22 also causes the automatic transmission 17 to shift up according to the degree of the target acceleration (S13).

[0057] The preceding vehicle following control device 22 performs deceleration control (S16-S24) if the target acceleration indicates a deceleration request (Yes in S14). Here, the target acceleration indicating a deceleration request means that the acquired target acceleration indicates deceleration in the direction of travel of the lean vehicle 1. For example, the acquired target acceleration indicates a deceleration request when it is a negative value. In deceleration control, the preceding vehicle following control device 22 reduces the opening of the throttle valve (S16). The lean vehicle 1 decelerates due to the deceleration control. Furthermore, the preceding vehicle following control device 22 causes the automatic transmission 17 to perform a downshift operation when the downshift condition is met during deceleration control (Yes in S18). Thus, the preceding vehicle following control device 22 causes the automatic transmission 17 to perform a downshift operation after deceleration control has started (S19). Furthermore, the preceding vehicle following control device 22 outputs a rear brake command (S22) when the rear brake condition is met (Yes in S21). As a result, the preceding vehicle following control device 22 causes the brake drive unit 21 to operate the rear brake unit 19. Furthermore, the preceding vehicle following control device 22 outputs a front brake command (S24) when the front brake condition is met (Yes in S23). As a result, the preceding vehicle following control device 22 causes the brake drive unit 21 to operate the front brake unit 18. Next, we will describe an embodiment in which detailed operating conditions are applied to each device in the lean vehicle 1 of the embodiment.

[0058] [First Embodiment] Figure 3 is a graph that schematically shows the operating conditions of each device in the first embodiment. In the graph in Figure 3, the horizontal axis represents the driving speed of the lean vehicle 1 in this embodiment. The vertical axis represents the shift control index value. The shift control index value is one of the indicators of the conditions under which a downshift is performed.

[0059] The preceding vehicle following control device 22 performs a downshift operation based on the driving speed and the shift control index value. In this embodiment, the target acceleration acquired by the preceding vehicle following control device 22 based on the distance to the preceding vehicle is used as the shift control index value. Therefore, in the graph of Figure 3, acceleration is shown as the shift control index value on the vertical axis. The acceleration in this embodiment is the acceleration acquired by the preceding vehicle following control device 22 based on the distance to the preceding vehicle. Note that acceleration is a parameter that also includes deceleration. For example, positive acceleration means acceleration, and negative acceleration means deceleration. To make the state of deceleration easier to understand, when the value of acceleration is negative, as shown in Figure 3, acceleration is also referred to as deceleration. However, deceleration is the opposite concept of acceleration, and in this specification, the smaller the value of acceleration (less than zero), that is, the more negative the value and the larger the absolute value, the smaller the acceleration or the greater the deceleration. The preceding vehicle following control device 22 also operates the front brake device 18 and the rear brake device 19 in accordance with the acceleration. Therefore, the graph in Figure 3 summarizes the operating conditions of the automatic transmission 17, the front brake device 18, and the rear brake device 19, which operate based on the acceleration as a shift control index value, in a way that makes their relationships easy to understand.

[0060] In Figure 3, D2 to D6 represent the gear shift reference lines from the 2nd gear line D2 to the 6th gear line D6, respectively. When the driving speed and shift control index value are in the region between the 2nd gear line D2 and the 3rd gear line D3 in Figure 2, the automatic transmission 17 selects the 2nd gear. When the driving speed and shift control index value are in the region between the 3rd gear line D3 and the 4th gear line D4, the automatic transmission 17 selects the 3rd gear. When they are in the region between the 4th gear line D4 and the 5th gear line D5, the automatic transmission 17 selects the 4th gear. When they are in the region between the 5th gear line D5 and the 6th gear line D6, the automatic transmission 17 selects the 5th gear. When the driving speed and shift control index value are in the region to the upper right of the 6th gear line D6, the automatic transmission 17 selects the 6th gear.

[0061] The 3rd gear line D3 to the 6th gear line D6 are set such that, under constant speed conditions, even if acceleration decreases from zero (or deceleration increases from zero), acceleration remains unchanged until it reaches the gear shift range Td. When acceleration reaches the gear shift range Td, the first downshift is performed, and further downshifts occur as acceleration decreases further. The gear shift range Td has a range. Here, the gear shift range Td is described as the lower limit of the range over which downshifts are more reliably performed. Furthermore, the effect of acceleration (deceleration) on the 2nd gear line D2 is small. In other words, in this embodiment, even if the speed is constant and the acceleration decreases, a downshift from 2nd gear to 1st gear will not occur.

[0062] The graph in Figure 3 also shows the reference acceleration Tr, which is the condition for the rear brake system 19 to operate, and the reference acceleration Tf, which is the condition for the front brake system 18 to operate. In the graph in Figure 3, the shift range Td of the automatic transmission 17 is located below the reference acceleration Tf of the front brake system 18. In other words, the shift range Td of the automatic transmission 17 is smaller than the reference acceleration Tf of the front brake system 18. The shift range Td is a negative value, and in absolute value it is larger than the reference acceleration Tf. Furthermore, the reference acceleration Tf of the front brake system 18 is smaller than the reference acceleration Tr of the rear brake system 19. Therefore, as the lean vehicle 1 moves from acceleration to deceleration and decreases below zero, the target acceleration falls below the reference acceleration Tr of the rear brake system 19, then below the reference acceleration Tf of the front brake system 18, and then below the gear range Td of the automatic transmission 17.

[0063] In this embodiment, the acceleration falling below the gear shift range Td applies to the downshift condition (S18) in the flowchart of Figure 2. Furthermore, the acceleration falling below the reference acceleration Tr of the rear brake device 19 applies to the rear brake sufficiency condition (S21). Additionally, the acceleration falling below the reference acceleration Tf of the front brake device 18 applies to the front brake sufficiency condition (S23).

[0064] Figure 4 is a time chart showing an example of the operation in the embodiment. Figure 4 shows an example of the operation when the conditions shown in Figure 2 are applied.

[0065] Referring to Figures 1 to 3, we will explain an example of the operation when the target acceleration changes to P2, given that the driving speed of lean vehicle 1 and the target acceleration as a shift control index value are the values ​​shown in P1 and lean vehicle 1 is accelerating.

[0066] At time t0, the target acceleration is P1. At this time, the throttle is open. Also, the 5th gear is selected in the automatic transmission 17. At time t1, the decrease in target acceleration begins. The target acceleration becomes less than zero and decreases to P2. That is, the target acceleration indicates deceleration. The target acceleration gradually decreases from time t1 to t10. This is because it follows the actual change in distance to the preceding vehicle. Also, to suppress abrupt deceleration caused by abrupt changes in target acceleration, the steep change component of the target acceleration is filtered out. At time t1, when the target acceleration begins to decrease, deceleration control (S16-S24) is executed. First, the throttle valve opening and fuel supply amount decrease. The throttle valve opens to its minimum position. As a result, lean vehicle 1, which was in an accelerating state, enters a decelerating state.

[0067] When the target acceleration decreases further (deceleration increases further) and falls below Tr (Figure 3) (Yes in S21 in Figure 2), the preceding vehicle following control device 22 activates the rear brake device 19 (S22 in Figure 2). When the target acceleration decreases further (deceleration increases further) and falls below Tf (Figure 3) at time t2 (Yes in S23 in Figure 2), the preceding vehicle following control device 22 activates the front brake device 18 (S24 in Figure 2). If the target acceleration decreases further (deceleration increases further) and falls below the gear range Td (Figure 3) at time t3 (Yes in S18 in Figure 2), the preceding vehicle following control device 22 causes the automatic transmission 17 to perform a downshift operation (S19 in Figure 2). As a result, the gear position of the automatic transmission 17 changes from 5th gear to 4th gear at time t3.

[0068] Thus, in the lean vehicle 1 of this embodiment, as the target acceleration decreases from P1 to P2, the throttle valve opening decreases, then the rear brake device 19 operates, then the front brake device 18 operates, and the automatic transmission 17 performs a downshift operation. In this embodiment, the automatic transmission 17 performs a downshift operation when the front brake device 18 is operating. After the preceding vehicle following control device 22 starts deceleration control of the lean vehicle 1 at time t1, it causes the automatic transmission 17 to perform a downshift operation to reduce the amount of sinking of the handlebars 15 caused by the operation of the front brake device 18.

[0069] The actual acceleration (deceleration) of the lean vehicle 1 depends on the sum of the braking force of the front wheels 14 and the braking force of the rear wheels 12. Here, the braking force of the front wheels 14 is the braking force from the front brake system 18. The braking force of the rear wheels 12 is the sum of the braking force from the rear brake system 19 and the rotational resistance torque of the output shaft 16a of the power source 16. The rotational resistance torque transmitted to the rear wheels 12 varies depending on the gear ratio in the automatic transmission 17. The downshift operation of the automatic transmission 17 from 5th gear to 4th gear at time t3 increases the rotational resistance torque of the output shaft 16a transmitted to the rear wheels 12. The braking force of the rear wheel 12 increases due to the downshifting action, which in turn reduces the braking force of the front wheel 14. In other words, while the deceleration of the lean vehicle 1 is maintained, the amount of front brake action decreases compared to the case where no downshifting action occurs (dashed line in Figure 4 for front brake action). As a result of the reduced front brake action, the amount of sinking of the handlebar 15 also decreases compared to the case where no downshifting action occurs (dashed line in Figure 4 for handlebar height). In this way, the amount of sinking of the handlebar 15 is suppressed, which in turn reduces the effect on the riding posture of the rider R who holds the handlebar 15 in a leaned position.

[0070] [Second Example] Next, we will describe the second embodiment. This embodiment differs from the first embodiment in that, instead of the target acceleration, it uses the actual acceleration of the lean vehicle 1 as the shift control index value. All other aspects of this embodiment are the same as those of the first embodiment.

[0071] The preceding vehicle following control device 22 acquires a target acceleration based on the distance to the preceding vehicle, similar to the first embodiment, and controls the power source 16 and the brake drive device 21 based on this target acceleration. The preceding vehicle following control device 22 also acquires the actual acceleration of the lean vehicle 1 using the speed detected by the speed sensor 24 provided on the lean vehicle 1, for example. The preceding vehicle following control device 22 controls the automatic transmission 17 based on the actual acceleration. In this embodiment, the satisfaction of the downshift condition (S18) in the flowchart of Figure 2 is determined using the actual acceleration. For example, when the actual acceleration decreases and falls below the gear shift range Td (Figure 3) (Yes in S18 of Figure 2), the preceding vehicle following control device 22 performs a downshift operation (S19 of Figure 2).

[0072] In this embodiment, the amount of movement of the front brake device 18 decreases as a downshift operation occurs based on the actual acceleration of the lean vehicle 1. Consequently, the braking force of the rear wheel 12 increases and the braking force of the front wheel 14 decreases, resulting in a suppression of the amount of sinking of the handlebar 15. As a result, the impact on the rider's riding posture is reduced.

[0073] [Third Embodiment] Next, we will describe the third embodiment. This embodiment differs from the first embodiment in that, instead of the target acceleration, the operating state of the front brake device 18 is used as the shift control index value. All other aspects are the same as the first embodiment.

[0074] The preceding vehicle following control device 22, for example, similar to the first embodiment, obtains a target acceleration based on the distance to the preceding vehicle and controls the power source 16 and the brake drive device 21 based on this target acceleration. In this embodiment, the preceding vehicle following control device 22 forces the automatic transmission 17 to perform a downshift operation when the front brake device 18 is operating. In this embodiment, the satisfaction of the downshift condition (S18) in the flowchart of Figure 2 is determined using the operating state of the front brake device 18. For example, if the acceleration decreases and falls below the reference acceleration Tf of the front brake device 18 (Figure 3), the preceding vehicle following control device 22 activates the front brake device 18. Then, if the front brake device 18 is activated (Yes in S18), the preceding vehicle following control device 22 performs a downshift operation (S19 in Figure 2). The preceding vehicle following control device 22 can determine the operation of the front brake device 18 when it has executed control to operate the front brake device 18. However, the preceding vehicle following control device 22 is not particularly limited, and for example, it may determine the operation of the front brake device 18 based on the detection result of a sensor provided on the front brake device 18 or the brake drive device 21.

[0075] [Fourth embodiment] Next, we will describe the fourth embodiment. This embodiment differs from the first embodiment in that, instead of the target acceleration, the operating amount of the front brake device 18 is used as the shift control index value. All other aspects are the same as the first embodiment.

[0076] The preceding vehicle following control device 22, for example, similar to the first embodiment, obtains a target acceleration based on the distance to the preceding vehicle and controls the power source 16 and the brake drive device 21 based on this target acceleration. In this embodiment, the preceding vehicle following control device 22 causes the automatic transmission 17 to perform a downshift operation based on the amount of movement of the front brake device 18. In this embodiment, the satisfaction of the downshift condition (S18) in the flowchart of Figure 2 is determined using the amount of movement of the front brake device 18. The amount of movement of the front brake system 18 is, for example, the pressure of the brake caliper provided on the front brake system 18. The detection result of a sensor that detects the pressure of the brake caliper is used as the amount of movement of the front brake system 18. However, the method of obtaining the amount of movement is not particularly limited, and for example, it may be the pressure of the hydraulic fluid supplied to the front brake system 18 by the brake drive unit 21. The detection result of a pressure sensor that detects the pressure of the hydraulic fluid is used as the amount of movement of the front brake system 18. For example, the adaptive cruise control device 22 will perform a downshift operation if the amount of movement of the front brake device 18 exceeds a first criterion. Furthermore, the adaptive cruise control device 22 will perform a further downshift operation if the amount of movement exceeds a second criterion.

[0077] Decisions based on the amount of action are not limited to those mentioned above.

[0078] Figure 5 is a graph showing the gear ratio characteristics in a modified example of the fourth embodiment. The vertical axis of the graph shows the shift control index value, which is the sum of the acceleration of the lean vehicle 1 and the amount of movement of the front brake device 18. The amount of movement is converted to a negative value, along with the acceleration, to indicate deceleration. When the shift control index value, which is the sum of acceleration and the negative value of the movement, reaches the gear range Td, the first downshift is performed. The system is configured to perform further downshifts as the shift control index value decreases further. In this modified example, the downshift is performed in accordance with both acceleration and movement.

[0079] As a result of the downshift operation based on the amount of movement of the front brake device 18, the amount of movement of the front brake device 18 decreases. Consequently, the braking force of the rear wheel 12 increases and the braking force of the front wheel 14 decreases, which suppresses the amount of sinking of the handlebar 15. As a result, the impact on the rider's riding posture is suppressed.

[0080] [Fifth Example] Next, we will describe the fifth embodiment. This embodiment differs from the fourth embodiment in that it uses a front brake control value, which is a control value of the front brake device 18, instead of the amount of operation of the front brake device 18. Other aspects are the same as the fourth embodiment. The front brake control value is, for example, a control value acquired by the preceding vehicle following control device 22 according to acceleration and speed, and is a control value that the preceding vehicle following control device 22 uses to operate the front brake device 18.

[0081] According to this embodiment, since the downshift operation is performed based on the front brake control value, the downshift operation is performed to reduce the amount of sinking of the handlebar 15 without detecting the actual operating state of the front brake. Therefore, the amount of sinking of the handlebar 15 can be suppressed with a small number of parts.

[0082] [Sixth Example] Figure 6 is a graph that schematically shows the operating conditions of each device in the sixth embodiment.

[0083] In the graph of Figure 6, the reference acceleration Tf' of the front brake device 18 is located below the shift range Td' of the automatic transmission 17. In other words, the reference acceleration Tf' of the front brake device 18 is smaller than the shift range Td' of the automatic transmission 17. The shift range Td' is a negative value, and in absolute value, it is smaller than the reference acceleration Tf'. Other aspects of this embodiment are the same as those of the first embodiment described above.

[0084] The reference acceleration Tf' of the front brake system 18 is smaller than the reference acceleration Tr' of the rear brake system 19. Also, the reference acceleration Tr' of the rear brake system 19 is larger than the shift range Td' of the automatic transmission 17. The reference acceleration Tf' is the planned operating range in which the front brake system 18 operates. Therefore, as the lean vehicle 1 moves from acceleration to deceleration, the target acceleration falls below zero and decreases, first below the reference acceleration Tr' of the rear brake device 19, then below the gear shift range Td' of the automatic transmission 17, and then below the reference acceleration Tf' of the front brake device 18.

[0085] In lean vehicle 1, for example, as the target acceleration decreases from P1 to P2, the throttle valve opening decreases, then the rear brake device 19 operates, then the automatic transmission 17 performs a downshift operation, and then the front brake device 18 operates. In lean vehicle 1 of this embodiment, the downshift operation occurs before the front brake device 18 operates. In this way, in the lean vehicle 1 of this embodiment, when the target acceleration is within the planned operating range for the front brake device 18, the automatic transmission 17 is instructed to perform a downshift operation to reduce the amount of sinking of the handlebars 15 caused by the operation of the front brake device 18.

[0086] Figure 7 is a time chart showing an example of the operation of the sixth embodiment.

[0087] At time t21, the decrease in target acceleration begins. The target acceleration becomes less than zero and decreases to P2. The target acceleration gradually decreases from time t21 to t24. At time t21, when the target acceleration begins to decrease, deceleration control (S16-S24 in Figure 2) is executed. First, the throttle valve is opened to its minimum position. As a result, lean vehicle 1, which was in an accelerating state, enters a decelerating state.

[0088] When the target acceleration decreases further and falls below Tr' (Figure 6) at time t22 (Yes in S21 in Figure 2), the preceding vehicle following control device 22 activates the rear brake device 19 (S22 in Figure 2). In this embodiment, the gear shift range Td' is set to the range in which the target acceleration is scheduled to operate when the front brake device 18 is activated. When the target acceleration decreases further and falls below the gear shift range Td' (Figure 6) at time t23 (Yes in S18 in Figure 2), the preceding vehicle following control device 22 performs a downshift operation (S19 in Figure 2). As a result, the gear position of the automatic transmission 17 changes from 5th gear to 4th gear at time t23. When the target acceleration decreases further (deceleration increases further) and falls below Tf' (Figure 6) at time t24 (Yes in S23 in Figure 2), the preceding vehicle following control device 22 activates the front brake device 18 (S24 in Figure 2).

[0089] Thus, in the lean vehicle 1 of this embodiment, as the target acceleration decreases from P1 to P2, the throttle valve opening decreases, then the rear brake device 19 operates, then the automatic transmission 17 performs a downshift operation, and then the front brake device 18 operates. Here, when the target acceleration is in the shift range Td', which is the planned operating range for the front brake device 18, the automatic transmission 17 performs a downshift operation. In this way, after the preceding vehicle following control device 22 starts deceleration control of the lean vehicle 1 at time t21, and before the operation of the front brake device 18, it causes the automatic transmission 17 to perform a downshift operation to reduce the amount of sinking of the handlebars 15 caused by the operation of the front brake device 18.

[0090] In this embodiment, a downshift operation is performed when the front brake device 18 is not operating and the target acceleration is within the planned operating range for the front brake device 18. By performing the downshift operation before the front brake device 18 actually operates, the reduction in the amount of handlebar 15 sinking when the front brake device 18 operates is suppressed. As a result, the impact on the rider's riding posture is reduced.

[0091] [Seventh Example] Next, we will describe the seventh embodiment. This embodiment differs from the sixth embodiment in that, instead of the target acceleration, the operating state of the rear brake device 19 is used as the shift control index value. All other aspects are the same as those of the sixth embodiment.

[0092] The preceding vehicle following control device 22, for example, similar to the sixth embodiment, obtains a target acceleration based on the distance to the preceding vehicle and controls the power source 16 and the brake drive device 21 based on this target acceleration. In this embodiment, the preceding vehicle following control device 22 forces the automatic transmission 17 to perform a downshift operation when the rear brake device 19 is operating. In this embodiment, the satisfaction of the downshift condition (S18) in the flowchart of Figure 2 is determined using the operating state of the rear brake device 19. For example, if the acceleration decreases and falls below the reference acceleration Tr' of the rear brake device 19 (Figure 6), the preceding vehicle following control device 22 activates the rear brake device 19. Then, if the rear brake device 19 is activated (Yes in S18), the preceding vehicle following control device 22 performs a downshift operation (S19 in Figure 2). Furthermore, the preceding vehicle following control device 22 can determine the operation of the front brake device 18 when it has executed a control to operate the rear brake device 19. However, the preceding vehicle following control device 22 is not particularly limited, and for example, it may determine the operation of the rear brake device 19 based on the detection result of a sensor provided on the rear brake device 19 or the brake drive device 21. When the rear brake device 19 is activated, a downshift operation is performed, which means that the downshift operation is performed before the front brake device 18 is activated.

[0093] [Eighth Example] Next, we will describe the eighth embodiment. This embodiment differs from the seventh embodiment in that, instead of the target acceleration, the illumination state of the brake lamp 25 is used as the shift control index value. All other aspects are the same as those of the seventh embodiment.

[0094] The preceding vehicle following control device 22, for example, similar to the seventh embodiment, obtains a target acceleration based on the distance to the preceding vehicle and controls the power source 16 and the brake drive device 21 based on this target acceleration. In this embodiment, the preceding vehicle following control device 22 forces the automatic transmission 17 to perform a downshift operation when the brake lamp 25 is illuminated. In this embodiment, the satisfaction of the downshift condition (S18) in the flowchart of Figure 2 is determined using the illumination state of the brake lamp 25. For example, when the acceleration decreases and falls below the reference acceleration Tr' (Figure 6) of the rear brake device 19, the preceding vehicle following control device 22 activates the rear brake device 19. Along with the activation of the rear brake device 19, the brake lights 25 illuminate. The brake lights 25 are illuminated, for example, by the control of the preceding vehicle following control device 22. If the brake lights 25 are illuminated (Yes in S18), the adaptive cruise control device 22 will perform a downshift operation (S19 in Figure 2). Furthermore, the preceding vehicle following control device 22 can determine that the brake lights 25 are illuminated when it has executed a control to illuminate the brake lights 25 itself. However, the preceding vehicle following control device 22 is not particularly limited, and for example, if a sensor provided on the brake drive device 21 detects the operation of the front brake device 18 or the rear brake device 19, the illumination may be determined based on the detection result of the sensor. When the brake light 25 is illuminated, a downshift operation is performed, which means the downshift operation is performed before the front brake device 18 is activated.

[0095] [Ninth Example] Next, we will describe the ninth embodiment. This embodiment differs from the sixth embodiment in that, instead of the target acceleration, a rear brake control value is used as the shift control index value to control the rear brake device 19. All other aspects are the same as those of the sixth embodiment.

[0096] In this embodiment, the preceding vehicle following control device 22 causes the automatic transmission 17 to perform a downshift operation based on the rear brake control value. In this embodiment, the satisfaction of the downshift condition (S18) in the flowchart of Figure 2 is determined using the rear brake control value. For example, the preceding vehicle following control device 22 will perform a downshift operation if the rear brake control value exceeds a first standard. Furthermore, the preceding vehicle following control device 22 will perform a further downshift operation if the amount of operation exceeds a second standard.

[0097] Decisions based on the amount of action are not limited to those mentioned above. A modified version of this embodiment will be explained using Figure 5. In this modified version, the vertical axis of the graph in Figure 5 represents the sum of the acceleration of the lean vehicle 1 and the amount of movement of the rear brake device 19, as the shift control index value. The amount of movement is the amount obtained by converting the acceleration, which indicates deceleration, into a negative value. When the shift control index value, which is the sum of the acceleration and the amount of movement converted into a negative value, reaches the gear shift range Td, the first downshift is performed, and the further the shift control index value decreases, the more downshifts are performed. In this modified example, the downshift is performed in accordance with both acceleration and the amount of motion.

[0098] [Tenth embodiment] Figure 8 is a graph schematically showing the operating conditions of each device in the 10th embodiment. Part (a) of Figure 8 is a chart showing the data processing and flow in the preceding vehicle following control device. Part (b) is a chart schematically showing examples of the operating conditions of each device.

[0099] In this embodiment, the preceding vehicle following control device 22 obtains a following acceleration for following the preceding vehicle based on its relationship with the preceding vehicle, and also obtains a target acceleration by removing abrupt change components from the following acceleration. Based on the target acceleration, it controls the acceleration or deceleration of the lean vehicle 1. More specifically, as shown in part (a) of Figure 8, the preceding vehicle following control device 22 obtains the following acceleration by performing a following process from inter-vehicle information representing the distance to the preceding vehicle. Furthermore, the preceding vehicle following control device 22 obtains the target acceleration by removing abrupt time-change components from the following acceleration. Removing steep time-varying components is a process that obtains the target acceleration by, for example, limiting the rate of change per unit time of the underlying tracking acceleration. However, the removal of steep time-varying components is not limited to this; for example, it may also be a process that obtains the target acceleration by performing filtering, such as integration, on the tracking accelerations obtained sequentially over time. The preceding vehicle following control device 22 controls the acceleration or deceleration of the lean vehicle 1 by controlling the power source 16 and the brake drive device 21 based on the target acceleration. In contrast, the preceding vehicle following control device 22 causes the automatic transmission 17 to perform a downshift operation based on the following acceleration, not the target acceleration.

[0100] As shown in part (b) of Figure 8, the power source 16, front brake system 18, and rear brake system 19 are controlled according to the target acceleration shown on the right side of the graph. Downshifting is controlled according to the tracking acceleration shown on the left side of the graph. Both the target acceleration and tracking acceleration represent acceleration and have the same scale on the graph. However, the tracking acceleration contains a steeper component of change compared to the target acceleration. In this embodiment, the acceleration or deceleration of the lean vehicle 1 is controlled based on a target acceleration from which steep change components have been removed.

[0101] Figure 9 is a time chart showing an example of operation in the 10th embodiment. The chart in Figure 9 shows both the tracking acceleration and the target acceleration.

[0102] The tracking acceleration is obtained from the relationship with the preceding vehicle as the acceleration required to follow the preceding vehicle. The target acceleration is obtained so as to follow the value of the tracking acceleration while limiting the rate of change per unit time. In the target acceleration, the steep time-varying component is removed from the tracking acceleration. The tracking acceleration changes from P1 to P2, and the target acceleration also changes from P1 to P2. However, the change in target acceleration is gradual. After deceleration control begins at time t31, if the tracking acceleration falls below the gear range Td at time t32, the automatic transmission 17 performs a downshift operation. If the target acceleration falls below the reference acceleration Tf at time t33, the front brake device 18 operates.

[0103] In this embodiment, the acceleration or deceleration of the lean vehicle 1 is controlled based on a target acceleration from which abrupt change components have been removed. As a result, abrupt behavior caused by the operation of the front brake device 18 is suppressed after the start of deceleration control. Furthermore, by using tracking acceleration to determine the downshift operation, the amount of sinking of the handlebars 15 can be suppressed in response to the operation of the front brake device 18 at an earlier stage. As a result, the impact on the rider's posture is suppressed at an earlier stage. [Explanation of symbols]

[0104] 1: Lean vehicle 11: Vehicle body 12: Rear wheel 13: Front Fork 14: Front wheel 15: Handlebars 16:Power source 16a: Output shaft 17: Automatic transmission 18: Front Brake System 19: Rear brake system 21: Brake drive system 22: Adaptive Cruise Control System 23: Shock absorber CA: Caster angle

Claims

1. A lean vehicle that tilts to the left during a left turn and to the right during a right turn, The lean vehicle is, The car body and, The rear wheels, which are drive wheels supported by the aforementioned vehicle body, A front fork is rotatably supported on the vehicle body so as to have a caster angle with respect to the vertical direction of the vehicle body, and is equipped with a shock absorber that extends and retracts in the axial direction of rotation, The front wheel is supported by the aforementioned front fork, A handlebar fixed to the front fork and held by the rider of the lean vehicle, A power source having an output shaft, which outputs power to drive the lean vehicle as rotation of the output shaft, An automatic transmission that changes the speed ratio between the rotation output from the output shaft and the rotation of the rear wheel by shifting up or down, A front brake device for braking the aforementioned front wheel, A rear brake device for braking the aforementioned rear wheel, A brake drive device that operates the front brake device and the rear brake device, A preceding vehicle following control device controls the power source, the brake drive device, and the automatic transmission device to control the acceleration or deceleration of the lean vehicle so that the lean vehicle follows the vehicle in front of it, Equipped with, After the preceding vehicle following control device starts deceleration control of the leaning vehicle, it causes the automatic transmission to perform a downshift operation to reduce the amount of handlebar sinking caused by the operation of the front brake device.

2. A lean vehicle according to claim 1, After the preceding vehicle following control device starts deceleration control of the leaning vehicle, if the front brake device is operating, it causes the automatic transmission to perform a downshift operation to reduce the amount of handlebar sinking caused by the operation of the front brake device.

3. A lean vehicle according to claim 2, The preceding vehicle following control device causes the automatic transmission to perform a downshift operation based on the amount of operation of the front brake device, in order to reduce the amount of sinking of the handlebars caused by the operation of the front brake device.

4. A lean vehicle according to claim 2 or 3, The preceding vehicle following control device acquires a target acceleration, controls the acceleration or deceleration of the leaning vehicle based on the target acceleration, and causes the automatic transmission to perform a downshift operation based on the target acceleration to reduce the amount of handlebar sinking caused by the operation of the front brake device.

5. A lean vehicle according to any one of claims 2 to 4, The preceding vehicle following control device detects the actual acceleration of the leaning vehicle and controls the acceleration or deceleration of the leaning vehicle based on the actual acceleration, and also causes the automatic transmission to perform a downshift operation based on the actual acceleration to reduce the amount of handlebar sinking caused by the operation of the front brake device.

6. A lean vehicle according to any one of claims 2 to 5, The preceding vehicle following control device acquires a front brake control value for the brake drive unit to operate the front brake unit, controls the acceleration or deceleration of the lean vehicle based on the front brake control value, and causes the automatic transmission to perform a downshift operation based on the front brake control value to reduce the amount of handlebar sinking caused by the operation of the front brake unit.

7. A lean vehicle according to claim 1, The preceding vehicle following control device acquires a target acceleration as a control target for acceleration or deceleration of the lean vehicle, and when the target acceleration is within the planned operating range for the operation of the front brake device, it causes the automatic transmission to perform a downshift operation to reduce the amount of handlebar sinking caused by the operation of the front brake device.

8. A lean vehicle according to claim 7, After the preceding vehicle following control device starts deceleration control of the leaning vehicle, if the rear brake device is operating, it forces the automatic transmission to perform a downshift operation to reduce the amount of handlebar sinking caused by the operation of the front brake device.

9. A lean vehicle according to claim 8, After the preceding vehicle following control device starts deceleration control of the lean vehicle, it causes the automatic transmission to perform a downshift operation based on the amount of operation of the rear brake device to reduce the amount of handlebar sinking caused by the operation of the front brake device.

10. A lean vehicle according to claim 8 or 9, The brake drive system further includes a brake lamp that illuminates when the front brake system or the rear brake system is operated, When the brake lights illuminate, the preceding vehicle following control device causes the automatic transmission to perform a downshift operation to reduce the amount of handlebar depression caused by the operation of the front brake device.

11. A lean vehicle according to any one of claims 8 to 10, The preceding vehicle following control device acquires a rear brake control value for the brake drive unit to operate the rear brake unit, controls the acceleration or deceleration of the lean vehicle based on the rear brake control value, and causes the automatic transmission to perform a downshift operation based on the rear brake control value to reduce the amount of handlebar sinking caused by the operation of the front brake unit.

12. A lean vehicle according to any one of claims 8 to 11, The preceding vehicle following control device obtains a following acceleration for following the preceding vehicle based on its relationship with the preceding vehicle, obtains a target acceleration by removing the abrupt change component from the following acceleration, controls the acceleration or deceleration of the lean vehicle based on the target acceleration, and causes the automatic transmission to perform a downshift operation based on the following acceleration to reduce the amount of handlebar sinking caused by the operation of the front brake device.

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