Control device for human-powered vehicles

Abstract

To provide a control device for a human-powered vehicle which controls a motor for providing propulsion power to a human-powered vehicle in a manner that a gear is easily changed in a transmission and a rider is less likely to feel a lack of assist force when the transmission changes a change gear ratio.SOLUTION: A control device for a human-powered vehicle includes a control unit which controls a motor for providing propulsion power to a human-powered vehicle. The human-powered vehicle includes a motor and a transmission of human drive power. The control unit is configured to cause the motor to assist propulsion of the human-powered vehicle in a state that the human-powered vehicle is propelled by human drive power. The control unit controls the motor when a change gear ratio of the transmission is changed so that an assist level by the motor is lowered according to the human drive power input to the human-powered vehicle and an assist level in a state, in which the human drive power is first human drive power, is larger than an assist level in a state, in which the human drive power is second human drive power smaller than the first human drive power.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a control device for a human-powered vehicle. [Background technology]

[0002] For example, the control device for a human-powered vehicle disclosed in Patent Document 1 reduces the output of the driving assistance motor in accordance with the human-powered driving force when the gear ratio of the transmission is changed while the propulsion of the human-powered vehicle is assisted by the driving assistance motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-151745 A Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the load acting on the transmission is reduced, making it easier to change gears through the transmission, but there are cases in which the rider feels that the assist force is insufficient.

[0005] One of the objectives of the present disclosure is to provide a control device for a human-powered vehicle that controls a motor that provides propulsive force to the human-powered vehicle so that, when the transmission changes the gear ratio, the transmission is easy to shift and the rider is less likely to feel a lack of assist force. [Means for solving the problem]

[0006] A control device according to a first aspect of the present disclosure is a control device for a human-powered vehicle, and includes a control unit that controls a motor that provides propulsive force to the human-powered vehicle, the human-powered vehicle including the motor and a human-powered force transmission, the control unit being configured to cause the motor to assist the propulsion of the human-powered vehicle when the human-powered vehicle is propelled by the human-powered force, and when the gear ratio of the transmission is changed, the control unit controls the motor to reduce the assist level according to the human-powered driving force input to the human-powered vehicle, and to control the motor so that the assist level when the human-powered driving force is a first human-powered driving force is greater than the assist level when the human-powered driving force is a second human-powered driving force smaller than the first human-powered driving force. According to the control device of the first aspect, when the gear ratio of the transmission is changed, the assist level by the motor is reduced according to the human driving force, making it easier for the transmission to shift gears. According to the control device of the first aspect, when the gear ratio of the transmission is changed, a sudden change in the assist force is suppressed, making it difficult for the rider to feel a lack of assist force.

[0007] In the control device of a second aspect according to the first aspect of the present disclosure, the assist level includes a ratio of an assist force by the motor to the manual driving force. According to the control device of the second aspect, the assist level can be changed by changing the ratio of the assist force by the motor to the manual driving force.

[0008] In the control device of a third aspect according to the first or second aspect of the present disclosure, the assist level includes a suppression level of output fluctuation of the motor when the output of the motor decreases. According to the control device of the third aspect, the assist level can be changed by changing the suppression level of the motor output fluctuation when the motor output decreases.

[0009] In the control device of a fourth aspect according to any one of the first to third aspects of the present disclosure, the control unit increases the assist level when a predetermined period of time has elapsed since the assist level was reduced. According to the control device of the fourth aspect, the assist level is increased after a predetermined period of time has elapsed since the assist level was reduced, thereby eliminating the need for the rider to perform operations to increase the assist level, thereby improving convenience.

[0010] In the control device of a fifth aspect according to any one of the first to fourth aspects of the present disclosure, the control unit increases the assist level when the change of the gear ratio is completed. According to the control device of the fifth aspect, the assist level is increased when the change in the gear ratio is completed, so there is no need for the rider to perform any operation to increase the assist level, thereby improving convenience.

[0011] In the control device of the sixth aspect according to the fourth aspect of the present disclosure, the predetermined period includes a period until the rotation amount of the wheels of the human-powered vehicle reaches a predetermined rotation amount, and the predetermined rotation amount is greater than or equal to 30 degrees and less than 460 degrees. According to the control device of the sixth aspect, when a period has elapsed until the rotation amount of the wheels of the human-powered vehicle reaches a rotation amount of more than 30 degrees and less than 460 degrees, the assist level is increased, so there is no need for the rider to perform any operation to increase the assist level, thereby improving convenience.

[0012] In the control device of a seventh aspect according to any one of the first to sixth aspects of the present disclosure, when the control unit reduces the assist level, the control unit reduces the assist level in accordance with the gear ratio. According to the control device of the seventh aspect, the control unit can control the motor at an assist level according to the gear ratio.

[0013] In the control device of an eighth aspect in accordance with the seventh aspect of the present disclosure, the control unit reduces the assist level when the manual driving force is a third manual driving force and the gear ratio is less than the first gear ratio so that the assist level is greater than the assist level when the manual driving force is the third manual driving force and the gear ratio is equal to or greater than the first gear ratio. According to the control device of the eighth aspect, the change in assist level is further suppressed when the gear ratio is relatively small than when the gear ratio is relatively large, making it less likely that the rider will feel a lack of assist force, particularly when the human-powered vehicle is traveling at low speed.

[0014] In the control device of a ninth aspect according to any one of the first to eighth aspects of the present disclosure, when the control unit reduces the assist level, the control unit reduces the assist level in accordance with the inclination angle of the road on which the human-powered vehicle is traveling. According to the control device of the ninth aspect, the control unit can control the motor at an assist level according to the inclination angle of the road.

[0015] In the control device of the tenth aspect according to the ninth aspect of the present disclosure, the control unit reduces the assist level when the manual driving force is a fourth manual driving force and the tilt angle is a first tilt angle or more so that the assist level is greater than the assist level when the manual driving force is a fourth manual driving force and the tilt angle is less than the first tilt angle. According to the control device of the tenth aspect, the change in the assist level is further suppressed when the inclination angle is relatively large than when the inclination angle is relatively small, making it less likely that the rider will feel a lack of assist force when the human-powered vehicle is traveling up a slope.

[0016] In the control device of an eleventh aspect according to any one of the first to tenth aspects of the present disclosure, when the control unit reduces the assist level, the control unit reduces the assist level in accordance with a pitch angle of the human-powered vehicle. According to the control device of the eleventh aspect, the control unit can control the motor at an assist level according to the pitch angle of the human-powered vehicle.

[0017] In the control device of the twelfth aspect in accordance with the eleventh aspect of the present disclosure, the control unit reduces the assist level when the manual driving force is a fourth manual driving force and the pitch angle is a first pitch angle or more so that the assist level is greater than the assist level when the manual driving force is a fourth manual driving force and the pitch angle is less than the first pitch angle. According to the control device of the twelfth aspect, the change in the assist level is further suppressed when the pitch angle is relatively large than when the pitch angle is relatively small, making it less likely that the rider will feel a lack of assist force when the human-powered vehicle is traveling up a slope.

[0018] In the control device of a thirteenth aspect according to any one of the first to twelfth aspects of the present disclosure, the control unit maintains the assist level when the gear ratio of the transmission is changed and when the manual driving force is smaller than a predetermined manual driving force. According to the control device of the thirteenth aspect, when the manual driving force is relatively small, the manual driving force acting on the transmission and the assist force by the motor acting on the transmission are relatively small, and the transmission can easily shift gears without lowering the assist level, thereby reducing the processing load on the control unit.

[0019] In the control device of a fourteenth aspect according to any one of the first to thirteenth aspects of the present disclosure, when the control unit reduces the assist level, the control unit reduces the assist level gradually. According to the control device of the fourteenth aspect, when the assist level is reduced, the assist level is reduced gradually, which makes it less likely that the rider will feel uncomfortable.

[0020] In the control device of a fifteenth aspect according to any one of the first to fourteenth aspects of the present disclosure, the human-powered vehicle has a crank to which the human-powered driving force is input, and the control unit initiates a process of reducing the assist level when the gear ratio of the transmission is changed and the angle of the crank is within a predetermined range. According to the control device of the fifteenth aspect, when the gear ratio of the transmission is changed, a process of lowering the assist level is initiated in accordance with a preferred crank angle, making it even easier for the transmission to change gears.

[0021] In the control device of a 16th aspect according to any one of the first to fifteenth aspects of the present disclosure, the transmission has a derailleur and a plurality of sprockets having a rotational axis and arranged in a direction in which the rotational axis extends, and the control unit reduces the assist level at least for the period while the plurality of sprockets rotate a predetermined angle when the gear ratio of the transmission is changed. According to the control device of the sixteenth aspect, when the gear ratio of the transmission is changed, the assist level is reduced at least while the plurality of sprockets rotate through a predetermined angle, making it even easier for the transmission to change gears.

[0022] In the control device of aspect 17 according to any one of aspects 1 to 16 of the present disclosure, when the control unit reduces the assist level provided by the motor, the control unit starts a process of reducing the assist level provided by the motor depending on the state of the shifting operation of the transmission. According to the control device of the seventeenth aspect, the process of reducing the motor assist level is initiated depending on the state of the gear shifting operation of the transmission, so that the control unit can reduce the motor assist level at a timing suitable for the gear shifting operation of the transmission.

[0023] In the control device of aspect 18 according to any one of aspects 1 to 17 of the present disclosure, the control unit reduces the assist level in accordance with the human-powered driving force input to the human-powered vehicle only in one of cases where the gear ratio increases and where the gear ratio decreases. According to the control device of the eighteenth aspect, the processing load on the control unit can be reduced.

[0024] In the control device of a 19th aspect according to any one of the first to eighteenth aspects of the present disclosure, the control unit is configured to control the transmission, and when changing the gear ratio of the transmission, causes the transmission to start a gear shift operation in response to a decrease in the manual driving force. According to the control device of the nineteenth aspect, when changing the gear ratio of the transmission, the transmission is caused to start a gear shifting operation in response to a decrease in the manual driving force, so that the transmission can easily shift gears. Effect of the Invention

[0025] The control device for a human-powered vehicle disclosed herein can control the motor that provides propulsive force to the human-powered vehicle so that, when changing the gear ratio of the transmission, the transmission can shift easily and the rider is less likely to feel a lack of assist force. [Brief description of the drawings]

[0026] [Figure 1] 1 is a side view of a human-powered vehicle including a control device for a human-powered vehicle according to an embodiment; [Diagram 2] 1 is a block diagram showing an electrical configuration of a human-powered vehicle including a control device for a human-powered vehicle according to an embodiment; [Diagram 3] 3 is a flowchart of a process executed by the control unit in FIG. 2 to control the transmission. [Figure 4] 3 is a flowchart of a process executed by the control unit in FIG. 2 to control a motor. [Diagram 5] 5 is a part of a flowchart of a first modified example of a process for controlling a motor, which is executed by the control unit of FIG. 2; [Figure 6] 10 is a part of a flowchart of a second modified example of the process executed by the control unit in FIG. 2 to control the motor. [Figure 7] 10 is a part of a flowchart of a third modified example of the process for controlling a motor, which is executed by the control unit in FIG. 2 . [Figure 8]11 is a part of a flowchart of a fourth modified example of the process for controlling a motor, which is executed by the control unit in FIG. 2; [Figure 9] 11 is a part of a flowchart of a fourth modified example of the process for controlling a motor, which is executed by the control unit in FIG. 2; [Figure 10] 13 is a flowchart of a process for controlling a motor, which is executed by a control unit of a fifth modified example. [Figure 11] 13 is a flowchart of a process for controlling a motor, which is executed by a control unit of a sixth modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] <Embodiment> A control device 60 for a human-powered vehicle according to an embodiment will be described with reference to Figs. 1 to 4. The human-powered vehicle 10 is a vehicle that has at least one wheel and can be driven by at least a human-powered driving force H. The human-powered vehicle 10 includes various types of bicycles, such as mountain bikes, road bikes, city bikes, cargo bikes, hand bikes, and recumbents. The number of wheels that the human-powered vehicle 10 has is not limited. The human-powered vehicle 10 also includes, for example, one-wheeled vehicles and vehicles with three or more wheels. The human-powered vehicle 10 is not limited to vehicles that can be driven only by the human-powered driving force H. The human-powered vehicle 10 includes an e-bike that uses not only the human-powered driving force H but also the driving force of an electric motor for propulsion. The e-bike includes an electrically assisted bicycle whose propulsion is assisted by an electric motor. In the following embodiment, the human-powered vehicle 10 will be described as an electrically assisted bicycle, and an example of an electrically assisted bicycle will be described as a mountain bike.

[0028] The human-powered vehicle 10 has a crank 12 to which a human-powered driving force H is input. The human-powered vehicle 10 further includes at least one wheel 14 and a vehicle body 16. The at least one wheel 14 includes a rear wheel 14A and a front wheel 14B. The vehicle body 16 includes a frame 18. The crank 12 includes an input rotating shaft 12A that is rotatable with respect to the frame 18, a first crank arm 12B, and a second crank arm 12C. The first crank arm 12B is provided at a first end in the axial direction of the input rotating shaft 12A. The second crank arm 12C is provided at a second end in the axial direction of the input rotating shaft 12A. In this embodiment, the input rotating shaft 12A is a crank shaft. A pedal 20A is connected to the first crank arm 12B. A pedal 20B is connected to the second crank arm 12C. The rear wheel 14A is driven by the rotation of the crank 12. The rear wheel 14A is supported by a frame 18. The crank 12 and the rear wheel 14A are connected by a drive mechanism 22.

[0029] The drive mechanism 22 includes a first rotor 24 connected to the input rotary shaft 12A. The input rotary shaft 12A and the first rotor 24 may be connected to rotate together, or may be connected via a first one-way clutch. The first one-way clutch is configured to rotate the first rotor 24 forward when the crank 12 rotates forward, and to allow relative rotation between the crank 12 and the first rotor 24 when the crank 12 rotates backward. The first rotor 24 includes a front sprocket. The first rotor 24 may include a pulley or a bevel gear. The drive mechanism 22 further includes a second rotor 26 and a connecting member 28. The connecting member 28 transmits the rotational force of the first rotor 24 to the second rotor 26. The connecting member 28 includes, for example, a chain, a belt, or a shaft.

[0030] The second rotating body 26 is connected to the rear wheel 14A. The second rotating body 26 includes a rear sprocket. The second rotating body 26 may include a pulley or a bevel gear. A second one-way clutch is preferably provided between the second rotating body 26 and the rear wheel 14A. The second one-way clutch is configured to rotate the rear wheel 14A forward when the second rotating body 26 rotates forward, and to allow relative rotation between the second rotating body 26 and the rear wheel 14A when the second rotating body 26 rotates backward.

[0031] A front wheel 14B is attached to the frame 18 via a front fork 30. A handlebar 34 is connected to the front fork 30 via a stem 32. In this embodiment, the rear wheel 14A is connected to the crank 12 by the drive mechanism 22, but at least one of the rear wheel 14A and the front wheel 14B may be connected to the crank 12 by the drive mechanism 22.

[0032] The human-powered vehicle 10 further includes a battery 36. The battery 36 includes one or more battery elements. The battery elements include a rechargeable battery. The battery 36 is configured to supply power to the control device 60. The battery 36 is preferably communicatively connected to a control unit 62 of the control device 60 via an electric cable or a wireless communication device. The battery 36 can communicate with the control unit 62 by, for example, power line communication (PLC), a controller area network (CAN), or a universal asynchronous receiver / transmitter (UART).

[0033] The human-powered vehicle 10 includes a motor 40 and a transmission 42 for transmitting human-powered driving force H. The transmission 42 is provided in a transmission path of the human-powered driving force H, and has a gear ratio R. device 42 has an input section to which a manual driving force H is input, and an output section to which the manual driving force H is output. The gear ratio R is the ratio of the rotation speed V1 of the input section of the gear shift device 42 to the rotation speed V2 of the input section of the gear shift device 42. ofThe gear ratio R is expressed by the ratio of the rotation speed V2 of the output section to the rotation speed V3 of the input section. The gear ratio R is expressed by Equation 1. When the rotation speed of the input section is constant, the larger the gear ratio R, the higher the rotation speed of the output section, and therefore the higher the rotation speed of the wheels 14. Formula 1… Gear ratio R = Rotational speed V2 / Rotational speed V1

[0034] Preferably, the shifting device 42 includes a derailleur 42A and a plurality of sprockets 42B having a rotation axis and arranged in a direction in which the rotation axis extends. When the derailleur 42A is a rear derailleur, the second rotating body 26 includes a plurality of sprockets 42B. When the derailleur 42A is a front derailleur, the first rotating body 24 includes a plurality of sprockets 42B. When the shifting device 42 includes the derailleur 42A, an output portion of the shifting device 42 corresponds to the second rotating body 26. When the shifting device 42 includes the derailleur 42A, an input portion of the shifting device 42 corresponds to the first rotating body 24. Preferably, the shifting device 42 includes an electric actuator. The electric actuator is provided in the derailleur 42A and operates the derailleur 42A. The shifting device 42 may include an internal gear shifter. The internal gear shifter is provided, for example, in the hub of the rear wheel 14A.

[0035] The motor 40 is configured to provide a propulsive force to the human-powered vehicle 10. The motor 40 includes one or more electric motors. The electric motor is, for example, a brushless motor. The motor 40 is configured to transmit a rotational force to the transmission 42 in a power transmission path of the human-powered driving force H from the pedals 20A, 20B to the rear wheel 14A. In this embodiment, the motor 40 is provided on the frame 18 of the human-powered vehicle 10, and is configured to transmit the rotational force to the first rotor 24.

[0036] The motor 40 is provided in a housing 44A. The housing 44A is provided in the frame 18. The housing 44A is, for example, detachably attached to the frame 18. The motor 40 and the housing 44A in which the motor 40 is provided constitute a drive unit 44. In this embodiment, a third one-way clutch is preferably provided in the power transmission path between the motor 40 and the input rotating shaft 12A, which suppresses transmission of the rotational force of the crank 12 to the motor 40 when the input rotating shaft 12A is rotated in the direction in which the human-powered vehicle 10 moves forward.

[0037] The human-powered vehicle 10 includes a control device 60. The control device 60 is preferably provided in the housing 44A of the drive unit 44. The control device 60 may be provided in the frame 18. The control device 60 includes a control unit 62. The control unit 62 includes a calculation processing unit that executes a predetermined control program. The calculation processing unit included in the control unit 62 includes, for example, a central processing unit (CPU) or a micro processing unit (MPU). The calculation processing units included in the control unit 62 may be provided in a plurality of locations that are separated from each other. The control unit 62 may include one or a plurality of microcomputers. Preferably, the control device 60 further includes a storage unit 64. The storage unit 64 stores the control program and information used in the control process. The storage unit 64 includes, for example, a non-volatile memory and a volatile memory. The non-volatile memory includes, for example, at least one of a read-only memory (ROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), and a flash memory. The volatile memory includes, for example, a random access memory (RAM).

[0038] The control device 60 preferably further includes a drive circuit 66 for the motor 40. The drive circuit 66 and the control unit 62 are preferably provided in the housing 44A of the drive unit 44. The drive circuit 66 and the control unit 62 may be provided on the same circuit board, for example. The drive circuit 66 includes an inverter circuit. The drive circuit 66 controls the power supplied from the battery 36 to the motor 40. The drive circuit 66 is connected to the control unit 62 via a conductive wire, an electric cable, a wireless communication device, or the like. The drive circuit 66 drives the motor 40 in response to a control signal from the control unit 62.

[0039] Preferably, the human-powered vehicle 10 further includes at least one of a vehicle speed sensor 46, a crank rotation sensor 48, and a human-powered driving force detection unit 50. The vehicle speed sensor 46 is configured to detect information related to the vehicle speed V of the human-powered vehicle 10. The vehicle speed sensor 46 is connected to the control unit 62 via a wireless communication device or an electric cable. In this embodiment, the vehicle speed sensor 46 is configured to detect information related to the rotation speed W of at least one wheel 14 of the human-powered vehicle 10. The vehicle speed sensor 46 outputs a signal corresponding to the rotation speed W of the wheel 14. The control unit 62 can calculate the vehicle speed V of the human-powered vehicle 10 based on the signal corresponding to the rotation speed W of the wheel 14 and information related to the circumference of the wheel 14. The memory unit 64 stores information related to the circumference of the wheel 14.

[0040] The vehicle speed sensor 46 includes, for example, a magnetic reed constituting a reed switch, or a magnetic sensor such as a Hall element. The vehicle speed sensor 46 may be attached to a chain stay of the frame 18 of the human-powered vehicle 10 and configured to detect a magnet attached to the rear wheel 14A, or may be provided on the front fork 30 and configured to detect a magnet attached to the front wheel 14B. In this embodiment, the vehicle speed sensor 46 is configured such that the reed switch detects the magnet once when the wheel 14 rotates once. The vehicle speed sensor 46 may have any configuration as long as it can obtain information regarding the vehicle speed V of the human-powered vehicle 10. The vehicle speed sensor 46 is not limited to a configuration that detects a magnet provided on the wheel 14, but may be configured to detect, for example, a slit provided on a disc brake, may be configured to include an optical sensor, or may be configured to include a GPS (Global Positioning System) receiver. When the vehicle speed sensor 46 includes a GPS receiver, the control unit 62 can calculate the vehicle speed V according to the time and the travel distance.

[0041] The crank rotation sensor 48 is configured to detect information related to the rotation speed C of the input rotating shaft 12A. The crank rotation sensor 48 is connected to the control unit 62 via a wireless communication device or an electric cable. The crank rotation sensor 48 is provided, for example, on the frame 18 or the drive unit 44 of the human-powered vehicle 10. The crank rotation sensor 48 may be provided on the housing 44A of the drive unit 44. The crank rotation sensor 48 includes a magnetic sensor that outputs a signal according to the strength of a magnetic field. An annular magnet whose magnetic field strength changes in the circumferential direction is provided on the input rotating shaft 12A, a member that rotates in conjunction with the input rotating shaft 12A, or a power transmission path between the input rotating shaft 12A and the first rotating body 24. The member that rotates in conjunction with the input rotating shaft 12A may include the output shaft of the motor 40.

[0042] The crank rotation sensor 48 outputs a signal corresponding to the rotation speed C of the input rotating shaft 12A. For example, if a first one-way clutch is not provided between the input rotating shaft 12A and the first rotating body 24, the magnet may be provided in the first rotating body 24. The crank rotation sensor 48 may have any configuration as long as it can acquire information related to the rotation speed C of the input rotating shaft 12A, and may include an optical sensor, an acceleration sensor, a gyro sensor, a torque sensor, or the like instead of a magnetic sensor.

[0043] The human-powered driving force detection unit 50 is configured to detect information related to the human-powered driving force H. The human-powered driving force detection unit 50 is connected to the control unit 62 via a wireless communication device or an electric cable. The human-powered driving force detection unit 50 is provided, for example, on the frame 18, the drive unit 44, the crank 12, or the pedals 20A, 20B of the human-powered vehicle 10. The human-powered driving force detection unit 50 may be provided on the housing 44A of the drive unit 44. The human-powered driving force detection unit 50 includes, for example, a torque sensor. The torque sensor is configured to output a signal corresponding to the torque applied to the crank 12 by the human-powered driving force H. For example, when a first one-way clutch is provided in the power transmission path, the torque sensor is preferably provided upstream of the first one-way clutch in the power transmission path. The torque sensor includes a strain sensor, a magnetostrictive sensor, a pressure sensor, or the like. The strain sensor includes a strain gauge.

[0044] The torque sensor is provided in the power transmission path or near a member included in the power transmission path. The member included in the power transmission path is, for example, the input rotating shaft 12A, a member that transmits the human-powered driving force H between the input rotating shaft 12A and the first rotating body 24, the crank arms 12B, 12C, or the pedals 20A, 20B. The human-powered driving force detection unit 50 may have any configuration as long as it can obtain information about the human-powered driving force H, and may include, for example, a sensor that detects the pressure applied to the pedals 20A, 20B, or a sensor that detects the tension of the chain.

[0045] Preferably, the control unit 62 is configured to control the transmission 42. The control device 60 and the electric actuator of the transmission 42 are connected via a conductive wire, an electric cable, a wireless communication device, or the like. The electric actuator of the transmission 42 is supplied with power from the battery 36. When changing the gear ratio R of the transmission 42, the control unit 62 causes the transmission 42 to start a gear shifting operation in response to a decrease in the human driving force H.

[0046] The control unit 62 may determine a decrease in the manual driving force H in accordance with the output of the manual driving force detection unit 50, for example. When the control unit 62 determines a decrease in the manual driving force H in accordance with the output of the manual driving force detection unit 50, the control unit 62 acquires a detection value of the manual driving force H at a predetermined cycle, for example, and compares the detection value detected last time with the detection value detected this time. If the detection value detected this time is smaller than the detection value detected last time, the control unit 62 determines that the manual driving force H has decreased. If the detection value detected this time is smaller than the detection value detected last time multiple times in succession, the control unit 62 may determine that the manual driving force H has decreased. The predetermined cycle is preferably shorter than the period in which the crank 12 rotates 5 degrees, for example.

[0047] The control unit 62 may determine the decrease in the manual driving force H according to, for example, the output of the crank rotation sensor 48. When the control unit 62 determines the decrease in the manual driving force H according to the output of the crank rotation sensor 48, the control unit 62 determines that the manual driving force H has decreased, for example, when the rotation angle of the input rotating shaft 12A falls within a range including an angle corresponding to an angle at which the manual driving force H is most likely to decrease. When the control unit 62 determines the decrease in the manual driving force H according to the output of the crank rotation sensor 48, the control unit 62 determines that the manual driving force H has decreased, for example, when the rotation angle of the input rotating shaft 12A falls within a predetermined range including the top dead center or bottom dead center of the crank arms 12B, 12C.

[0048] Preferably, the human-powered vehicle 10 further includes a gear shift operating device 56. The gear shift operating device 56 is configured to be operable by the user's hand. The gear shift operating device 56 is provided on the handlebar 34, for example. The gear shift operating device 56 is connected to the control unit 62 via a wireless communication device or an electric cable. The gear shift operating device 56 includes a first operating unit for increasing the gear ratio R of the transmission 42, and a second operating unit for decreasing the gear ratio R of the transmission 42. When the first operating unit is operated, a gear shift request for increasing the gear ratio R is generated in the control unit 62, and the gear shift request is transmitted from the first operating unit to the control unit 62. When the second operating unit is operated, a gear shift request for decreasing the gear ratio R is generated in the control unit 62, and the gear shift request is transmitted from the second operating unit to the control unit 62. Each of the first operating unit and the second operating unit includes an operating member and a detection unit that detects the operation of the operating member. The detection unit includes an electric switch or a sensor. The type of sensor included in the detection unit is not limited, and may be a magnetic sensor or an optical sensor.

[0049] The process by which the control unit 62 switches the control state of the transmission 42 will be described with reference to Fig. 3. For example, when power is supplied to the control unit 62, the control unit 62 starts the process and proceeds to step S11 of the flowchart shown in Fig. 3. When the flowchart of Fig. 3 ends, the control unit 62 repeats the process from step S11 after a predetermined period, for example, until the supply of power is stopped.

[0050] In step S11, the control unit 62 determines whether or not a gear shift request has been generated. A gear shift request is generated by operating the gear shift operating device. The control unit 62 may generate a gear shift request by itself in response to at least one of the driving state and driving environment of the human-powered vehicle 10. The driving state of the human-powered vehicle 10 includes at least one of the vehicle speed V, the rotation speed C of the input rotating shaft 12A, the human-powered driving force H, and the pitch angle of the human-powered vehicle 10. The driving environment of the human-powered vehicle 10 includes the gradient of the road on which the human-powered vehicle 10 is traveling. The control unit 62 compares a predetermined threshold value with a parameter related to at least one of the driving state and driving environment of the human-powered vehicle 10, and generates a gear shift request in at least one of the cases where the parameter is greater than the predetermined threshold value and where the parameter is smaller than the predetermined threshold value. If a gear shift request has not been generated, the control unit 62 ends the process. If a gear shift request has been generated, the control unit 62 proceeds to step S12.

[0051] In step S12, the control unit 62 determines whether or not a gear shift is possible. For example, when a gear shift request to increase the gear ratio R occurs and the current gear ratio R is smaller than the maximum gear ratio R of the transmission 42, the control unit 62 determines that a gear shift is possible. For example, when a gear shift request to increase the gear ratio R occurs and the current gear ratio R is the maximum gear ratio R of the transmission 42, the control unit 62 determines that a gear shift is not possible. For example, when a gear shift request to decrease the gear ratio R occurs and the current gear ratio R is larger than the minimum gear ratio R of the transmission 42, the control unit 62 determines that a gear shift is possible. For example, when a gear shift request to decrease the gear ratio R occurs and the current gear ratio R is the minimum gear ratio R of the transmission 42, the control unit 62 determines that a gear shift is not possible. If a gear shift request to decrease the gear ratio R occurs and the current gear ratio R is the minimum gear ratio R of the transmission 42, the control unit 62 determines that a gear shift is not possible. If a gear shift is not possible, the control unit 62 ends the process. If a gear shift is possible, the control unit 62 proceeds to step S13.

[0052] In step S13, the control unit 62 determines whether the manual driving force H has decreased. If the manual driving force H has not decreased, the control unit 62 executes the determination process of step S13 again. If the manual driving force H has decreased, the control unit 62 proceeds to step S14.

[0053] In step S14, the control unit 62 starts the gear shifting operation of the transmission 42, and then ends the process. The control unit 62 drives the electric actuator of the transmission 42 to start the gear shifting operation of the transmission 42.

[0054] The control unit 62 is configured to control the motor 40 that provides a propulsive force to the human-powered vehicle 10. Preferably, the control unit 62 controls the motor 40 in response to at least one of the vehicle speed V, the rotation speed C of the input rotating shaft 12A, and the human-powered driving force H. Preferably, the control unit 62 is configured to control the motor 40 in response to the human-powered driving force H input to the human-powered vehicle 10. The human-powered driving force H may be represented by torque or may be represented by power.

[0055] The control unit 62 is configured to control the motor 40 so that the assist level by the motor 40 becomes a predetermined assist level A. For example, the assist level A includes a ratio of the assist force by the motor 40 to the manual driving force H. For example, the assist level A includes a suppression level L of the output fluctuation of the motor 40 when the output of the motor 40 decreases. For example, the assist level A may include only one of the ratio of the assist force by the motor 40 to the manual driving force H and the suppression level L of the output fluctuation of the motor 40 when the output of the motor 40 decreases, or may include both. The assist level A may include an upper limit value MX of the output of the motor 40 in addition to at least one of the ratio of the assist force by the motor 40 to the manual driving force H and the suppression level L of the output fluctuation of the motor 40 when the output of the motor 40 decreases.

[0056] The ratio of the assist force by the motor 40 to the human-powered driving force H may be referred to as the assist ratio. The control unit 62 is configured to control the motor 40 so that the assist force by the motor 40 is a predetermined ratio to the human-powered driving force H, for example. The human-powered driving force H corresponds to the propulsive force of the human-powered vehicle 10 generated by the user rotating the crank 12. The assist force corresponds to the propulsive force of the human-powered vehicle 10 generated by the rotation of the motor 40. The predetermined ratio is not constant, and may change, for example, according to the human-powered driving force H, the rotation speed C of the input rotating shaft 12A, the vehicle speed V, or any two or all of the human-powered driving force H, the rotation speed C of the input rotating shaft 12A, and the vehicle speed V.

[0057] When the manual driving force H and the assisting force are expressed in terms of torque, the manual driving force H is written as manual torque HT, and the assisting force is written as assisting torque MT. When the manual driving force H and the assisting force are expressed in terms of power, the manual driving force H is written as manual power HW, and the assisting force is written as assisting power MW. The ratio of the assisting force by the motor 40 to the manual driving force H may be the torque ratio of the assisting torque MT to the manual torque HT of the human-powered vehicle 10, or may be the ratio of the assisting power MW by the motor 40 to the human power HW.

[0058] In the drive unit 44 of this embodiment, the crank 12 is connected to the first rotating body 24 without a transmission, and the output of the motor 40 is input to the first rotating body 24. In this embodiment, the manual driving force H corresponds to the driving force input to the first rotating body 24 by the user rotating the crank 12. In this embodiment, the assist force corresponds to the driving force input to the first rotating body 24 by the rotation of the motor 40. When the output of the motor 40 is input to the first rotating body 24 via a reducer, the assist force corresponds to the output of the reducer.

[0059] The control unit 62 is configured to control the motor 40 so that the assist force is equal to or less than the upper limit value MX. When the output of the motor 40 is input to the first rotating body 24 and the assist force is expressed by torque, the control unit 62 is configured to control the motor 40 so that the assist torque MT is equal to or less than the upper limit value MTX. Preferably, the upper limit value MTX is a value in the range of 20 Nm to 200 Nm. When the output of the motor 40 is input to the first rotating body 24 and the assist force is expressed by power, the control unit 62 is configured to control the motor 40 so that the assist power MW is equal to or less than the upper limit value MWX.

[0060] Preferably, the control unit 62 is configured to be able to change the suppression level L of the output fluctuation of the motor 40. As the suppression level L of the output fluctuation of the motor 40 increases, the amount of change per unit time of the output of the motor 40 relative to the amount of change per unit time of the control parameter of the motor 40 decreases. As the suppression level L of the output fluctuation of the motor 40 decreases, the amount of change per unit time of the output of the motor 40 relative to the amount of change per unit time of the control parameter of the motor 40 increases. In this embodiment, the control parameter of the motor 40 corresponds to the manual driving force H. The control parameter of the motor 40 may correspond to the rotation speed C of the input rotating shaft 12A. Preferably, the suppression level L of the output fluctuation of the motor 40 corresponds to the suppression level L when the manual driving force H or the rotation speed C of the input rotating shaft 12A decreases. The suppression level L of the output fluctuation of the motor 40 is inversely proportional to the response speed of the motor 40. The response speed of the motor 40 is represented by the amount of change per unit time of the output of the motor 40 relative to the amount of change per unit time of the control parameter of the motor 40. When the suppression level L of the output fluctuation of the motor 40 increases, the response speed of the motor 40 decreases.

[0061] The control unit 62 changes the suppression level L, for example, by a filter circuit. The filter circuit includes, for example, a low-pass filter having a time constant. The control unit 62 changes the suppression level L by changing the time constant of the filter. The control unit 62 may change the suppression level L by changing a gain for calculating the output of the motor 40 from the manual driving force H. The filter circuit is configured, for example, by executing predetermined software in a calculation processing device.

[0062] The control unit 62 is configured to cause the motor 40 to assist the propulsion of the human-powered vehicle 10 in a state in which the human-powered vehicle 10 is propelled by a human-powered driving force H. When the gear ratio R of the transmission 42 is changed, the control unit 62 controls the motor 40 to lower the assist level A by the motor 40 in accordance with the human-powered driving force H input to the human-powered vehicle 10, and to make the assist level A when the human-powered driving force H is a first human-powered driving force H1 greater than the assist level A when the human-powered driving force H is a second human-powered driving force H2 smaller than the first human-powered driving force H1. The first human-powered driving force H1 and the second human-powered driving force H2 may be expressed by torque or by power.

[0063] For example, when the gear ratio R of the transmission 42 is changed and the manual driving force is a first manual driving force H1, the control unit 62 sets the assist level A to a first assist level A1. The state where the manual driving force H is the first manual driving force H1 corresponds to the state where the manual driving force H is equal to or greater than a predetermined first driving force HY. For example, when the gear ratio R of the transmission 42 is changed and the manual driving force H is a second manual driving force H2, the control unit 62 sets the assist level A to a second assist level A2. The state where the manual driving force H is the second manual driving force H2 corresponds to the state where the manual driving force H is less than the predetermined first driving force HY. The first assist level A1 is greater than the second assist level A2.

[0064] Preferably, when the gear ratio R of the transmission 42 is changed and the input driving force H is smaller than a predetermined input driving force HX, the control unit 62 maintains the assist level A. The predetermined input driving force HX is smaller than a predetermined first driving force HY.

[0065] For example, when the assist level A is represented by the ratio of the assist force by the motor 40 to the input driving force H and the input driving force H is represented by torque, the control unit 62 decreases the assist level A as shown in Table 1. The reduction rate of the assist level A is the ratio of the assist level A after reduction to the assist level A before reduction. In Table 1, X1 and X2 are numerical values and X1 < X2. X1 is, for example, 30, and X2 is, for example, 60.

[0066]

Table 1

[0067] Preferably, when the gear ratio R of the transmission 42 is changed and the angle of the crank 12 is within a predetermined range, the control unit 62 starts the process of decreasing the assist level A. The predetermined range includes, for example, an angle at which the positions of the crank arms 12B and 12C are 90 degrees away from the positions corresponding to the top dead center or the bottom dead center at the angle of the crank 12. The predetermined range includes, for example, a range from 10 degrees to 45 degrees centered on an angle at which the positions of the crank arms 12B and 12C are 90 degrees away from the positions corresponding to the top dead center or the bottom dead center at the angle of the crank 12. As the predetermined range, for example, a range in which the rider hardly feels the decrease in the assist level A is set.

[0068] Preferably, when lowering the assist level A provided by the motor 40, the control unit 62 initiates a process of lowering the assist level A provided by the motor 40 in accordance with the state of the gear shifting operation of the transmission 42. For example, the control unit 62 lowers the assist level A when the gear shifting operation of the transmission 42 is started. When the transmission 42 is a transmission 42 equipped with an electric actuator, the control unit 62 may start lowering the assist level A after a gear shift request is generated and before the gear shifting operation of the transmission 42 is started.

[0069] Preferably, when lowering the assist level A, the control unit 62 gradually lowers the assist level A. When lowering the assist level A to the first assist level A1, the control unit 62 may lower the assist level A stepwise every time a predetermined time elapses to the first assist level A1. When lowering the assist level A to the first assist level A1, the control unit 62 may continuously lower the assist level A to the first assist level A1. When lowering the assist level A to the second assist level A2, the control unit 62 may lower the assist level A stepwise every time a predetermined time elapses to the second assist level A2. When lowering the assist level A to the second assist level A2, the control unit 62 may continuously lower the assist level A to the second assist level A2 every time a predetermined time elapses.

[0070] Preferably, the control unit 62 increases the assist level A when a predetermined period of time TX has elapsed since the assist level A was reduced. Preferably, the predetermined period of time TX includes a period until the rotation amount of the wheels 14 of the human-powered vehicle 10 reaches a predetermined rotation amount. The predetermined rotation amount is equal to or greater than 30 degrees and less than 460 degrees. Preferably, the predetermined rotation amount is set according to a period from the start to the completion of the shifting operation of the transmission 42. Preferably, the control unit 62 changes the assist level A so as to return to the assist level A before the assist level A was reduced when a predetermined period of time TX has elapsed since the assist level A was reduced. The assist level A before the assist level A was reduced is, for example, the assist level A immediately before the assist level A was reduced.

[0071] Preferably, the control unit 62 increases the assist level A when the change of the gear ratio R is completed. Preferably, the transmission 42 has a gear shift state detection unit that detects information related to the current gear shift stage. The gear shift state detection unit includes, for example, a sensor that outputs a signal in response to the operation of an electric actuator. The control unit 62 may determine whether or not the change of the gear ratio R is completed in response to the rotation speed C of the input rotating shaft 12A and the rotation speed W of the wheels 14. When the manual driving force H is equal to or greater than a predetermined threshold, the control unit 62 calculates the gear ratio R from the rotation speed C of the input rotating shaft 12A and the rotation speed W of the wheels 14. Preferably, when the change of the gear ratio R is completed, the control unit 62 changes the assist level A so that the assist level A returns to the assist level A before the assist level A was reduced.

[0072] With reference to Fig. 4, a process of switching the control state in which the control unit 62 controls the motor 40 will be described. For example, when power is supplied to the control unit 62, the control unit 62 starts the process and proceeds to step S21 of the flowchart shown in Fig. 4. When the flowchart in Fig. 4 ends, the control unit 62 repeats the process from step S21 after a predetermined period, for example, until the supply of power is stopped.

[0073] In step S21, the control unit 62 determines whether or not the gear ratio R of the transmission 42 is to be changed. If the gear ratio R of the transmission 42 is not to be changed, the control unit 62 ends the process. If the gear ratio R of the transmission 42 is to be changed, the control unit 62 proceeds to step S23. In this embodiment, when a gear shift request occurs, the control unit 62 determines that the gear ratio R of the transmission 42 is to be changed.

[0074] In step S23, the control unit 62 determines whether the manual driving force H is equal to or greater than a predetermined manual driving force HX. If the manual driving force H is equal to or greater than the predetermined manual driving force HX, the control unit 62 proceeds to step S24. If the manual driving force H is not equal to or greater than the predetermined manual driving force HX in step S23, the control unit 62 ends the process.

[0075] In step S24, the control unit 62 determines whether the manual driving force H is equal to or greater than a predetermined first driving force HY. If the manual driving force H is equal to or greater than the predetermined first driving force HY, the control unit 62 proceeds to step S25. In step S25, the control unit 62 changes the assist level A to the first assist level A1, and proceeds to step S27.

[0076] If the manual driving force H is not equal to or greater than the predetermined first driving force HY in step S24, the control unit 62 proceeds to step S26. In step S26, the control unit 62 changes the assist level A to the second assist level A2, and proceeds to step S27.

[0077] In step S27, the control unit 62 determines whether or not a predetermined period of time TX has elapsed. If the predetermined period of time TX has elapsed, the control unit 62 proceeds to step S29. If the predetermined period of time TX has not elapsed, the control unit 62 proceeds to step S28. In step S28, the control unit 62 determines whether or not the change in the gear ratio R has been completed. If the change in the gear ratio R has not been completed, the control unit 62 proceeds to step S27. If the change in the gear ratio R has been completed, the control unit 62 proceeds to step S29. In step S29, the control unit 62 increases the assist level A and ends the process.

[0078] The control unit 62 may reduce the assist level A in accordance with at least one of the driving state of the human-powered vehicle 10 and the driving environment of the human-powered vehicle 10 in addition to the human-powered driving force H.

[0079] When lowering the assist level A, the control unit 62 may lower the assist level A according to the gear ratio R. Preferably, the control unit 62 lowers the assist level A so that the assist level A when the manual driving force H is the third manual driving force H3 and the gear ratio R is less than the first gear ratio R1 is greater than the assist level A when the manual driving force H is the third manual driving force H3 and the gear ratio R is equal to or greater than the first gear ratio R1. The third manual driving force H3 may be the same as or different from the predetermined first driving force HY. Preferably, the third manual driving force H3 is greater than the predetermined manual driving force HX.

[0080] For example, when the third manual driving force H3 is the first manual driving force H1, the control unit 62 reduces the assist level A to a first assist level A1 that differs depending on the gear ratio R. For example, the first assist level A1 includes a first assist level A11 when the gear ratio R is less than the first gear ratio R1, and a first assist level A12 when the gear ratio R is equal to or greater than the first gear ratio R1. The first assist level A11 is greater than the first assist level A12.

[0081] For example, when the control unit 62 reduces the assist level A to the first assist level A1 and when the gear ratio R is less than the first gear ratio R1, the control unit 62 reduces the assist level A to the first assist level A11. When the control unit 62 reduces the assist level A to the first assist level A1 and when the gear ratio R is equal to or greater than the first gear ratio R1, the control unit 62 reduces the assist level A to the first assist level A12.

[0082] For example, when the third manual driving force H3 is the second manual driving force H2, the control unit 62 reduces the assist level A to a second assist level A2 that differs depending on the gear ratio R. For example, the second assist level A2 includes a second assist level A21 when the gear ratio R is less than the first gear ratio R1, and a second assist level A22 when the gear ratio R is equal to or greater than the first gear ratio R1. The second assist level A21 is greater than the second assist level A22.

[0083] For example, when the control unit 62 reduces the assist level A to the second assist level A2 and when the gear ratio R is less than the first gear ratio R1, the control unit 62 reduces the assist level A to the second assist level A21. When the control unit 62 reduces the assist level A to the second assist level A2 and when the gear ratio R is equal to or greater than the first gear ratio R1, the control unit 62 reduces the assist level A to the second assist level A22.

[0084] 4 and 5, a process of a first modified example in which the control unit 62 switches the control state for controlling the motor 40 will be described. For example, when power is supplied to the control unit 62, the control unit 62 starts the process and proceeds to step S21 of the flowchart shown in Fig. 4. When the flowchart of Fig. 4 ends, the control unit 62 repeats the process from step S21 after a predetermined period, for example, until the supply of power is stopped.

[0085] In the first modified example, the control unit 62 executes the same process as in FIG. 4, except that the control unit 62 executes the process of FIG. 5 instead of the processes of steps S24, S25, and S26 in FIG. 4. Therefore, the explanation of the steps that are the same as in FIG. 4 will be omitted.

[0086] If the determination in step S23 is YES, the control unit 62 proceeds to step S51 in Fig. 5. In step S51, the control unit 62 determines whether the manual driving force H is equal to or greater than a predetermined first driving force HY. If the manual driving force H is equal to or greater than the predetermined first driving force HY, the control unit 62 proceeds to step S52.

[0087] In step S52, the control unit 62 determines whether the gear ratio R is less than the first gear ratio R1. If the gear ratio R is less than the first gear ratio R1, the control unit 62 proceeds to step S53. In step S53, the control unit 62 changes the assist level A to the first assist level A11, and proceeds to step S27.

[0088] If the gear ratio R is not less than the first gear ratio R1 in step S52, the control unit 62 proceeds to step S54. In step S54, the control unit 62 changes the assist level A to the first assist level A12, and proceeds to step S27.

[0089] If the manual driving force H is not equal to or greater than a predetermined first driving force HY in step S51, the control unit 62 proceeds to step S55. In step S55, the control unit 62 determines whether the gear ratio R is less than the first gear ratio R1. If the gear ratio R is less than the first gear ratio R1, the control unit 62 proceeds to step S56. In step S56, the control unit 62 changes the assist level A to the second assist level A21, and proceeds to step S27.

[0090] If the speed ratio R is not less than the first speed ratio R1 in step S55, the control unit 62 proceeds to step S57. In step S57, the control unit 62 changes the assist level A to the second assist level A22, and proceeds to step S27.

[0091] When lowering the assist level A, the control unit 62 may lower the assist level A in accordance with the inclination angle S of the road on which the human-powered vehicle 10 is traveling. In this case, the human-powered vehicle 10 preferably includes a first inclination detection unit 52 that detects the inclination angle S.

[0092] The first inclination detection unit 52 is configured to detect the inclination angle S of the road on which the human-powered vehicle 10 is traveling. The inclination angle S corresponds to the inclination angle in the traveling direction of the human-powered vehicle 10. The inclination angle S corresponds to the pitch angle of the human-powered vehicle 10. The first inclination detection unit 52 includes a GPS receiver. The control unit 62 may calculate the inclination angle S according to GPS information acquired by the GPS receiver and information on the road surface gradient included in map information pre-recorded in the storage unit 64. The first inclination detection unit 52 is connected to the control unit 62 via a wireless communication device or an electric cable.

[0093] Preferably, the control unit 62 reduces the assist level A when the manual driving force H is the fourth manual driving force H4 and the tilt angle S is equal to or larger than the first tilt angle S1 so that the assist level A is greater than the assist level A when the manual driving force H is the fourth manual driving force H4 and the tilt angle S is less than the first tilt angle S1. The fourth manual driving force H4 may be the same as or different from the predetermined first driving force HY. Preferably, the predetermined manual driving force HX is smaller than the fourth manual driving force H4.

[0094] For example, when the fourth manual driving force H4 is the first manual driving force H1, the control unit 62 reduces the assist level A to the first assist level A1 according to the tilt angle S. For example, the first assist level A1 includes a first assist level A13 when the tilt angle S is equal to or greater than the first tilt angle S1, and a first assist level A14 when the tilt angle S is less than the first tilt angle S1. The first assist level A13 is greater than the first assist level A14.

[0095] For example, when the control unit 62 reduces the assist level A to the first assist level A1 and when the tilt angle S is equal to or greater than the first tilt angle S1, the control unit 62 reduces the assist level A to the first assist level A13. When the control unit 62 reduces the assist level A to the first assist level A1 and when the tilt angle S is less than the first tilt angle S1, the control unit 62 reduces the assist level A to the first assist level A14.

[0096] For example, when the fourth manual driving force H4 is the second manual driving force H2, the control unit 62 reduces the assist level A to the second assist level A2 according to the tilt angle S. For example, the second assist level A2 includes a second assist level A23 when the tilt angle S is equal to or greater than the first tilt angle S1, and a second assist level A24 when the tilt angle S is less than the first tilt angle S1. The second assist level A23 is greater than the second assist level A24.

[0097] For example, when the control unit 62 reduces the assist level A to the second assist level A2 and when the tilt angle S is equal to or greater than the first tilt angle S1, the control unit 62 reduces the assist level A to the second assist level A23. When the control unit 62 reduces the assist level A to the second assist level A2 and when the tilt angle S is less than the first tilt angle S1, the control unit 62 reduces the assist level A to the second assist level A24.

[0098] 4 and 6, a process of the second modified example in which the control unit 62 switches the control state for controlling the motor 40 will be described. For example, when power is supplied to the control unit 62, the control unit 62 starts the process and proceeds to step S21 of the flowchart shown in Fig. 4. When the flowchart in Fig. 4 ends, the control unit 62 repeats the process from step S21 after a predetermined period, for example, until the supply of power is stopped.

[0099] In the second modified example, the control unit 62 executes the same process as in FIG. 4, except that the control unit 62 executes the process of FIG. 6 instead of the processes of steps S24, S25, and S26 in FIG. 4. Therefore, the explanation of the steps that are the same as in FIG. 4 will be omitted.

[0100] If the determination in step S23 is YES, the control unit 62 proceeds to step S61 in Fig. 6. In step S61, the control unit 62 determines whether the manual driving force H is equal to or greater than a predetermined first driving force HY. If the manual driving force H is equal to or greater than the predetermined first driving force HY, the control unit 62 proceeds to step S62.

[0101] In step S62, the control unit 62 determines whether the tilt angle S is equal to or greater than the first tilt angle S1. If the tilt angle S is equal to or greater than the first tilt angle S1, the control unit 62 proceeds to step S63. In step S63, the control unit 62 changes the assist level A to the first assist level A13, and proceeds to step S27.

[0102] If the tilt angle S is not equal to or greater than the first tilt angle S1 in step S62, the control unit 62 proceeds to step S64. In step S64, the control unit 62 changes the assist level A to the first assist level A14, and proceeds to step S27.

[0103] If the manual driving force H is not equal to or greater than a predetermined first driving force HY in step S61, the control unit 62 proceeds to step S65. In step S65, the control unit 62 determines whether the tilt angle S is equal to or greater than the first tilt angle S1. If the tilt angle S is equal to or greater than the first tilt angle S1, the control unit 62 proceeds to step S66. In step S66, the control unit 62 changes the assist level A to the second assist level A23, and proceeds to step S27.

[0104] If the tilt angle S is not equal to or greater than the first tilt angle S1 in step S65, the control unit 62 proceeds to step S67. In step S67, the control unit 62 changes the assist level A to the second assist level A24, and proceeds to step S27.

[0105] When lowering the assist level A, the control unit 62 may lower the assist level A in accordance with the pitch angle D of the human-powered vehicle 10. In this case, the human-powered vehicle 10 preferably includes a second tilt detection unit 54 that detects the pitch angle D.

[0106] The second tilt detection unit 54 is configured to detect the pitch angle D. The pitch angle D can be detected by the tilt angle in the traveling direction of the human-powered vehicle 10. The second tilt detection unit 54 includes at least one of a gyro sensor and an acceleration sensor. The second tilt detection unit 54 is connected to the control unit 62 via a wireless communication device or an electric cable.

[0107] Preferably, the control unit 62 reduces the assist level A when the manual driving force H is the fourth manual driving force H4 and the pitch angle D is equal to or greater than the first pitch angle D1 so that the assist level A is greater than the assist level A when the manual driving force H is the fourth manual driving force H4 and the pitch angle D is less than the first pitch angle D1. The fourth manual driving force H4 may be the same as or different from the predetermined first driving force HY. Preferably, the predetermined manual driving force HX is smaller than the fourth manual driving force H4.

[0108] When the fourth manual driving force H4 is the first manual driving force H1, the control unit 62 reduces the assist level A to a first assist level A1 that differs depending on the pitch angle D. For example, the first assist level A1 includes a first assist level A15 when the pitch angle D is equal to or greater than the first pitch angle D1, and a first assist level A16 when the pitch angle D is less than the first pitch angle D1. The first assist level A15 is greater than the first assist level A16.

[0109] For example, when the control unit 62 reduces the assist level A to the first assist level A1 and when the pitch angle D is equal to or greater than the first pitch angle D1, the control unit 62 reduces the assist level A to the first assist level A15. When the control unit 62 reduces the assist level A to the first assist level A1 and when the pitch angle D is less than the first pitch angle D1, the control unit 62 reduces the assist level A to the first assist level A16.

[0110] When the fourth manual driving force H4 is the second manual driving force H2, the control unit 62 reduces the assist level A to a second assist level A2 that differs depending on the pitch angle D. For example, the second assist level A2 includes a second assist level A25 when the pitch angle D is equal to or greater than the first pitch angle D1, and a second assist level A26 when the pitch angle D is less than the first pitch angle D1. The second assist level A25 is greater than the second assist level A26.

[0111] For example, when the control unit 62 reduces the assist level A to the second assist level A2 and when the pitch angle D is equal to or greater than the first pitch angle D1, the control unit 62 reduces the assist level A to the second assist level A25. When the control unit 62 reduces the assist level A to the second assist level A2 and when the pitch angle D is less than the first pitch angle D1, the control unit 62 reduces the assist level A to the second assist level A26. The second assist level A25 is greater than the second assist level A26.

[0112] 4 and 7, a process of the third modified example in which the control unit 62 switches the control state for controlling the motor 40 will be described. For example, when power is supplied to the control unit 62, the control unit 62 starts the process and proceeds to step S21 of the flowchart shown in Fig. 4. When the flowchart of Fig. 4 ends, the control unit 62 repeats the process from step S21 after a predetermined period, for example, until the supply of power is stopped.

[0113] In the third modified example, the control unit 62 executes the same process as in FIG. 4, except that the control unit 62 executes the process of FIG. 7 instead of the processes of steps S24, S25, and S26 in FIG. 4. Therefore, the explanation of the steps that are the same as in FIG. 4 will be omitted.

[0114] If the determination in step S23 is YES, the control unit 62 proceeds to step S71 in Fig. 7. In step S71, the control unit 62 determines whether the manual driving force H is equal to or greater than a predetermined first driving force HY. If the manual driving force H is equal to or greater than the predetermined first driving force HY, the control unit 62 proceeds to step S72.

[0115] In step S72, the control unit 62 determines whether the pitch angle D is equal to or greater than the first pitch angle D1. If the pitch angle D is equal to or greater than the first pitch angle D1, the control unit 62 proceeds to step S73. In step S73, the control unit 62 changes the assist level A to the first assist level A15, and proceeds to step S27.

[0116] If the pitch angle D is not equal to or greater than the first pitch angle D1 in step S72, the control unit 62 proceeds to step S74. In step S74, the control unit 62 changes the assist level A to the first assist level A16, and proceeds to step S27.

[0117] If the manual driving force H is not equal to or greater than a predetermined first driving force HY in step S71, the control unit 62 proceeds to step S75. In step S75, the control unit 62 determines whether the pitch angle D is equal to or greater than the first pitch angle D1. If the pitch angle D is equal to or greater than the first pitch angle D1, the control unit 62 proceeds to step S76. In step S76, the control unit 62 changes the assist level A to the second assist level A25, and proceeds to step S27.

[0118] If the pitch angle D is not equal to or greater than the first pitch angle D1 in step S75, the control unit 62 proceeds to step S77. In step S77, the control unit 62 changes the assist level A to the second assist level A26, and proceeds to step S27.

[0119] The control unit 62 may reduce the assist level A in accordance with two or more of the gear ratio R, the tilt angle S, and the pitch angle D in addition to the manual driving force H. When reducing the assist level A in accordance with two or more of the gear ratio R, the tilt angle S, and the pitch angle D in addition to the manual driving force H, the control unit 62 may, for example, calculate an assist level A corresponding to at least two of the gear ratio R, the tilt angle S, and the pitch angle D, and select the smallest assist level A from the calculated assist levels A.

[0120] When the control unit 62 reduces the assist level A in accordance with at least two of the gear ratio R, the tilt angle S, and the pitch angle D in addition to the manual driving force H, the control unit 62 may reduce the assist level A in accordance with information on the assist level A in which the manual driving force H is previously associated with at least two of the gear ratio R, the tilt angle S, and the pitch angle D. The information on the assist level A in which the manual driving force H is previously associated with at least two of the gear ratio R, the tilt angle S, and the pitch angle D is stored in advance in the storage unit 64. The information on the assist level A in which the manual driving force H is previously associated with at least two of the gear ratio R, the tilt angle S, and the pitch angle D includes, for example, a table.

[0121] 4, 8, and 9, a process of the fourth modified example in which the control unit 62 switches the control state for controlling the motor 40 will be described. For example, when power is supplied to the control unit 62, the control unit 62 starts the process and proceeds to step S21 of the flowchart shown in Fig. 4. When the flowchart of Fig. 4 ends, the control unit 62 repeats the process from step S21 after a predetermined period, for example, until the supply of power is stopped.

[0122] In the fourth modified example, the control unit 62 executes the same processing as in FIG. 4, except that instead of the processing of steps S24, S25, and S26 in FIG. 4, the control unit 62 executes the processing of FIGS. 8 and 9. Therefore, the explanation of the steps that are the same as in FIG. 4 will be omitted.

[0123] When the determination in step S23 is YES, the control unit 62 proceeds to step S81 in Fig. 8. In step S81, the control unit 62 determines whether the manual driving force H is equal to or greater than a predetermined first driving force HY. When the manual driving force H is equal to or greater than the predetermined first driving force HY, the control unit 62 proceeds to step S82.

[0124] In step S82, the control unit 62 determines whether the gear ratio R is less than the first gear ratio R1. If the gear ratio R is less than the first gear ratio R1, the control unit 62 proceeds to step S83. In step S83, the control unit 62 determines whether the tilt angle S is equal to or greater than the first tilt angle S1. If the tilt angle S is equal to or greater than the first tilt angle S1, the control unit 62 proceeds to step S84. In step S84, the control unit 62 changes the assist level A to the first assist level A17, and proceeds to step S27.

[0125] If the tilt angle S is not equal to or greater than the first tilt angle S1 in step S83, the control unit 62 proceeds to step S85. In step S85, the control unit 62 changes the assist level A to the first assist level A18, and proceeds to step S27.

[0126] If the speed ratio R is not less than the first speed ratio R1 in step S82, the control unit 62 proceeds to step S86. In step S86, the control unit 62 determines whether the tilt angle S is equal to or greater than the first tilt angle S1. If the tilt angle S is equal to or greater than the first tilt angle S1, the control unit 62 proceeds to step S87. In step S87, the control unit 62 changes the assist level A to the first assist level A19, and proceeds to step S27.

[0127] If the tilt angle S is not equal to or greater than the first tilt angle S1 in step S86, the control unit 62 proceeds to step S88. In step S88, the control unit 62 changes the assist level A to the first assist level A110, and proceeds to step S27.

[0128] When the manual driving force H is not equal to or greater than a predetermined first driving force HY in step S81, the control unit 62 proceeds to step S89.

[0129] In step S89, the control unit 62 determines whether the gear ratio R is less than the first gear ratio R1. If the gear ratio R is less than the first gear ratio R1, the control unit 62 proceeds to step S90. In step S90, the control unit 62 determines whether the tilt angle S is equal to or greater than the first tilt angle S1. If the tilt angle S is equal to or greater than the first tilt angle S1, the control unit 62 proceeds to step S91. In step S91, the control unit 62 changes the assist level A to the second assist level A27, and proceeds to step S27.

[0130] If the tilt angle S is not equal to or greater than the first tilt angle S1 in step S90, the control unit 62 proceeds to step S92. In step S92, the control unit 62 changes the assist level A to the second assist level A28, and proceeds to step S27.

[0131] If the speed ratio R is not less than the first speed ratio R1 in step S89, the control unit 62 proceeds to step S93. In step S93, the control unit 62 determines whether the tilt angle S is equal to or greater than the first tilt angle S1. If the tilt angle S is equal to or greater than the first tilt angle S1, the control unit 62 proceeds to step S94. In step S94, the control unit 62 changes the assist level A to the second assist level A29, and proceeds to step S27.

[0132] If the tilt angle S is not equal to or greater than the first tilt angle S1 in step S93, the control unit 62 proceeds to step S95. In step S95, the control unit 62 changes the assist level A to the second assist level A210, and proceeds to step S27.

[0133] 4, 8, and 9, the control unit 62 may change the process of determining whether the tilt angle S is equal to or greater than the first tilt angle S1 to a process of determining whether the pitch angle D is equal to or greater than the first pitch angle D1. In this case, the case where the tilt angle S is determined to be equal to or greater than the first tilt angle S1 should be interpreted as the case where the pitch angle D is determined to be equal to or greater than the first pitch angle D1.

[0134] <Modification> The explanations of the embodiments are examples of forms that a control device for a human-powered vehicle according to the present disclosure can take, and are not intended to limit the forms. A control device for a human-powered vehicle according to the present disclosure can take forms, for example, modified versions of the embodiments shown below, and forms that combine at least two mutually consistent modified versions. In the following modified versions, parts that are common to the embodiments are given the same reference numerals as in the embodiments, and descriptions thereof are omitted.

[0135] When the gear ratio R of the transmission 42 is changed, the control unit 62 may reduce the assist level A at least while the multiple sprockets rotate a predetermined angle. In this case, the human-powered vehicle 10 includes a rotational phase detection unit 58, shown by a dashed line in FIG. 2, that detects the rotational phase of the multiple sprockets 42B. The rotational phase detection unit 58 includes, for example, a magnetic reed constituting a reed switch, or a magnetic sensor such as a Hall element. The magnetic sensor is configured, for example, to be attached to one of the multiple sprockets 42B and the frame 18, and to detect a magnet attached to the other of the multiple sprockets 42B and the frame 18. The multiple sprockets may be the first rotating body 24 or the second rotating body 26. The multiple sprockets correspond to a derailleur that operates when the gear ratio of the transmission 42 is changed. For example, the control unit 62 executes the process of step S31 in FIG. 10 instead of the process of step S27 in FIG. 4. After executing the process of step S25 in FIG. 10, the control unit 62 proceeds to step S31. After executing the process of step S26 in FIG. 10, the control unit 62 proceeds to step S31. In step S31, the control unit 62 determines whether at least a plurality of sprockets 42B have rotated through a predetermined rotation angle. Information regarding the predetermined rotation angle is stored in the memory unit 64. If at least the plurality of sprockets 42B have rotated through the predetermined rotation angle, the control unit 62 proceeds to step S29. If at least the plurality of sprockets 42B have not rotated through the predetermined rotation angle, the control unit 62 proceeds to step S28. At least one sprocket of the plurality of sprockets 42B has a gear shift promotion region. The predetermined rotation angle is set according to the gear shift promotion region. For example, if a sprocket has two gear shift promotion regions, the predetermined angle is an angle equal to or greater than 180 degrees and equal to or less than 360 degrees. The predetermined rotation angle may be set individually for each sprocket included in the plurality of sprockets 42B.

[0136] The control unit 62 may reduce the assist level A according to the human-powered driving force H input to the human-powered vehicle 10 only when the gear ratio R increases or when the gear ratio R decreases. The control unit 62 executes the process of step S41 in FIG. 11, for example, instead of the process of step S21 in FIG. 4. When, for example, power is supplied to the control unit 62, the control unit 62 starts the process and proceeds to step S41 in the flowchart shown in FIG. 11. When the flowchart in FIG. 11 ends, the control unit 62 repeats the process from step S41 after a predetermined period, for example, until the supply of power is stopped. In step S41, the control unit 62 determines whether the gear ratio R is to be changed to one of the directions of increasing or decreasing. If the gear ratio R is not to be changed to one of the directions of increasing or decreasing, the control unit 62 ends the process. If the gear ratio R is to be changed to one of the directions of increasing or decreasing, the control unit 62 proceeds to step S23. The control unit 62 may be configured to be able to change between a state in which the assist level A is reduced in accordance with the human-powered driving force H input to the human-powered vehicle 10 when the gear ratio R is increasing, and a state in which the assist level A is reduced in accordance with the human-powered driving force H input to the human-powered vehicle 10 when the gear ratio R is decreasing. For example, when the first setting information is stored in the memory unit 64, the control unit 62 reduces the assist level A in accordance with the human-powered driving force H input to the human-powered vehicle 10 only when the gear ratio R increases. For example, when the second setting information is stored in the memory unit 64, the control unit 62 reduces the assist level A in accordance with the human-powered driving force H input to the human-powered vehicle 10 only when the gear ratio R decreases. The first setting information and the second setting information may be changed by an external device such as a personal computer, a tablet computer, or a smartphone.

[0137] The transmission 42 may be a manual transmission 42. In this case, the process of the flowchart in FIG. 3 is omitted. In step S21 in FIG. 4, step S21 in FIG. 10, and step S41 in FIG. 11, the control unit 62 determines whether or not the gear ratio R is to be changed in response to the output of a sensor that detects the movement of the derailleur 42A, the movement of the Bowden cable, or the operating state of the gear shift operating device. Control unit 62 determines that the gear ratio will be changed when, for example, there is a change in the output of a sensor that detects the movement of the derailleur 42A, the movement of the Bowden cable, or the operating state of the gear shifting device.

[0138] The control unit 62 may change the assist level A when the gear ratio R of the transmission 42 is changed according to the running resistance of the human-powered vehicle 10, instead of or in addition to at least one of the tilt angle S and the pitch angle D. For example, the control unit 62 lowers the assist level A so that the assist level A when the human-powered driving force H is the fifth human-powered driving force H5 and the running resistance is equal to or greater than the first running resistance is greater than the assist level A when the human-powered driving force H is the fifth human-powered driving force H5 and the running resistance is less than the first running resistance. The fifth human-powered driving force H5 may be the same as or different from the predetermined first driving force HY. Preferably, the fifth human-powered driving force H5 is greater than the predetermined human-powered driving force HX.

[0139] The control unit 62 may change the assist level A when the gear ratio R of the transmission 42 is changed according to the acceleration of the human-powered vehicle 10, instead of or in addition to at least one of the tilt angle S and the pitch angle D. For example, the control unit 62 lowers the assist level A when the human-powered driving force H is the sixth human-powered driving force H6 and the acceleration is equal to or greater than the first acceleration, so that the assist level A is greater than the assist level A when the human-powered driving force H is the sixth human-powered driving force H6 and the acceleration is less than the first acceleration. The sixth human-powered driving force H6 may be the same as or different from the predetermined first driving force HY. Preferably, the sixth human-powered driving force H6 is greater than the predetermined human-powered driving force HX.

[0140] ·When the manual driving force H is equal to or greater than a first driving force HY determined in advance, as the manual driving force H increases, the control unit 62 may control the motor 40 so that the reduction rate of the assist level A when the gear ratio R of the transmission 42 is changed decreases. When the manual driving force H is less than the first driving force HY determined in advance, as the manual driving force H decreases, the control unit 62 may control the motor 40 so that the reduction rate of the assist level A when the gear ratio R of the transmission 42 is changed increases. Tables 2 and 3 show other examples of the relationship between the manual driving force H and the assist level A. Table 2 shows the reduction rate of the assist level A when the assist level A is represented by the ratio of the assist force by the motor 40 to the manual driving force H and the manual driving force H is represented by torque. The seventh manual driving force H7 is greater than the first manual driving force H1. When the manual driving force H is equal to or greater than an eighth manual driving force H8 greater than the first manual driving force H1, the control unit 62 may prevent the assist level A from decreasing. The eighth manual driving force H8 is, for example, greater than the seventh manual driving force H7. In Table 2, X11, X12, and X13 are numerical values, and X11 < X12 < X13. X11 is, for example, 10, X12 is, for example, 30, and X13 is, for example, 60.

[0141]

Table 2

[0142] Table 3 shows an example of the time constant when the assist level A is represented by the suppression level L of the output fluctuation of the motor. In Table 3, T1, T2, and T3 are numerical values, and T1 > T2 > T3.

[0143]

Table 3

[0144] The control unit 62 may omit step S23 in Figures 4, 10, and 11. In this case, if the determination in step S21 is YES, the control unit 62 proceeds to step S24.

[0145] The control unit 62 may omit step S27 in Figures 4 and 11. In this case, the control unit 62 may proceed to step S28 after executing the process of step S25.

[0146] The control unit 62 may omit step S28 in Figures 4, 10, and 11. In this case, if the determination in step S27 in Figure 4 or Figure 11 is NO, the control unit 62 executes the process of step S27 again, and if the determination in step S31 in Figure 10 is NO, the control unit 62 executes the process of step S31 again.

[0147] The predetermined period TX may be a period from when the assist level A is reduced until a predetermined time has elapsed.

[0148] The term "at least one" as used herein means "one or more" of the desired options. As an example, the term "at least one" as used herein means "only one option" or "both of two options" if the number of options is two. As another example, the term "at least one" as used herein means "only one option" or "any combination of two or more options" if the number of options is three or more. [Explanation of symbols]

[0149] 10... human-powered vehicle, 12... crank, 14... wheel, 40... motor, 42... transmission, 42A... derailleur, 42B... sprocket, 60... control device, 62... control section.

Claims

1. A control device for a human-powered vehicle, a control unit that controls a motor that provides a propulsive force to the human-powered vehicle; The human-powered vehicle includes the motor and a human-powered transmission. The control unit is a motor is configured to assist the propulsion of the human-powered vehicle when the human-powered vehicle is propelled by the human-powered driving force; when the gear ratio of the transmission is changed, an assist level by the motor is reduced in accordance with the human-powered driving force input to the human-powered vehicle, and the motor is controlled so that the assist level when the human-powered driving force is a first human-powered driving force is greater than the assist level when the human-powered driving force is a second human-powered driving force that is smaller than the first human-powered driving force; A control device, wherein the assist level includes a ratio of the assist force by the motor to the manual driving force.

2. The control device according to claim 1 , wherein the assist level includes, in addition to the ratio, a suppression level of the output fluctuation of the motor when the output of the motor decreases.

3. The control device according to claim 1 , wherein the control unit increases the assist level when a predetermined period of time has elapsed since the assist level was reduced.

4. The control device according to claim 1 , wherein the control unit increases the assist level when the change in the gear ratio is completed.

5. the predetermined period includes a period until the rotation amount of the wheels of the human-powered vehicle reaches a predetermined rotation amount, The control device according to claim 3 , wherein the predetermined amount of rotation is equal to or greater than 30 degrees and less than 460 degrees.

6. The control device according to claim 1 , wherein, when the control unit is to reduce the assist level, the control unit reduces the assist level in accordance with the gear ratio.

7. 7. The control device according to claim 6, wherein the control unit reduces the assist level when the manual driving force is a third manual driving force and the gear ratio is less than the first gear ratio so that the assist level is greater than the assist level when the manual driving force is the third manual driving force and the gear ratio is equal to or greater than the first gear ratio.

8. The control device according to claim 1 , wherein, when the control unit reduces the assist level, the control unit reduces the assist level in accordance with an inclination angle of a road on which the human-powered vehicle is traveling.

9. 9. The control device according to claim 8, wherein the control unit reduces the assist level when the manual driving force is a fourth manual driving force and the tilt angle is a first tilt angle or more so that the assist level is greater than the assist level when the manual driving force is the fourth manual driving force and the tilt angle is less than the first tilt angle.

10. The control device according to claim 1 , wherein, when the control unit reduces the assist level, the control unit reduces the assist level in accordance with a pitch angle of the human-powered vehicle.

11. 11. The control device according to claim 10, wherein the control unit reduces the assist level when the manual driving force is a fourth manual driving force and the pitch angle is a first pitch angle or more so that the assist level is greater than the assist level when the manual driving force is the fourth manual driving force and the pitch angle is less than the first pitch angle.

12. The control device according to claim 1 , wherein the control unit maintains the assist level when the gear ratio of the transmission is changed and when the manual driving force is smaller than a predetermined manual driving force.

13. The control device according to claim 1 , wherein the control unit, when decreasing the assist level, gradually decreases the assist level.

14. the human-powered vehicle has a crank to which the human-powered driving force is input, The control device according to claim 1 , wherein the control unit starts a process of reducing the assist level when the gear ratio of the transmission is changed and the crank angle is within a predetermined range.

15. The transmission includes a derailleur and a plurality of sprockets having a rotation axis and aligned in a direction along which the rotation axis extends. The control device according to claim 1 , wherein the control unit reduces the assist level when the gear ratio of the transmission is changed, at least while the plurality of sprockets rotate a predetermined angle.

16. The control device according to claim 1 , wherein when the control unit is to reduce the assist level by the motor, the control unit starts a process of reducing the assist level by the motor depending on a state of a shifting operation of the transmission.

17. 17. The control device according to claim 1, wherein the control unit reduces the assist level in accordance with the human-powered driving force input to the human-powered vehicle only in one of a case where the gear ratio increases and a case where the gear ratio decreases.

18. 18. The control device according to claim 1, wherein the control unit is configured to control the transmission and, when changing the gear ratio of the transmission, causes the transmission to start a gear shift operation in response to a decrease in the human-powered driving force.

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