DRIVE DEVICE OF A HUMAN-POWERED VEHICLE

Abstract

To provide a propulsion device for a human-powered vehicle that appropriately controls an electric motor with respect to the reverse rotation of a crank, a propulsion device for a human-powered vehicle includes an electric motor and a controller. The electric motor is configured to rotate in a first direction and assist the propulsion of a human-powered vehicle when the crank is rotating forward, and to receive a driving force from the crank and rotate in a second direction when the crank is rotating backward. The second direction of rotation is opposite to the first.The controller controls the electric motor to generate a torque in the second direction of rotation in at least one of a state in which the crank rotates backwards, and in a state in which a human driving force is applied to the crank so that the crank rotates backwards.

Description

[0001] This application claims priority over Japanese patent application No. JP 2018-125344, which was filed on June 29, 2018.

[0002] The present disclosure relates to a propulsion device of a human-powered vehicle.

[0003] The Japanese patent publication JP H10-250673A discloses a propulsion device for a human-powered vehicle, comprising a crank and an electric motor. Human power is supplied to the crank. The electric motor assists the propulsion of the human-powered vehicle in proportion to the human power supplied.

[0004] Drive devices are known from the prior art, such as in connection with a bicycle hub arrangement and a bicycle control system from DE 10 2017 007 192 A1, a control device for a vehicle from DE 20 2012 100 098 U1 and a brake mechanism for bicycles with electric auxiliary drive that can be operated by pedaling backwards from EP 2 664 533 A1.

[0005] DE 10 2017 007 192 A1 discloses a gear mechanism housed in the hub shell, which functions as a coaster brake actuator and gear shifter. The gear mechanism is designed so that the rotational movement of the hub driver is transmitted to the hub shell and the coaster brake shoe, depending on the direction of rotation of the hub driver. The hub driver rotates in the reverse direction when the rider pedals backward to stop the bicycle. A control device prevents the motor from generating torque when the hub driver rotates in the reverse direction.

[0006] DE 20 2012 100 098 U1 discloses a motor control system that determines the rotation and instantaneous rotational speed of the inner shaft based on an optical sensor. If the inner shaft is moved backwards by more than a predetermined angle and a minimum speed or acceleration is exceeded, the motor control system switches the motor to generator mode for energy recovery purposes and simultaneously activates a reverse brake.

[0007] EP 2 664 533 A1 discloses a reverse braking mechanism and magnetic sensors. The magnetic sensors detect the direction of rotation of the crankshaft, thereby controlling the motor's assistance. When the crankshaft rotates backward, the motor's output is interrupted. In the drive system of a human-powered vehicle disclosed in Japanese patent JP H10-250 673 A, the reverse rotation of the crank affects the electric motor, and vice versa. However, these effects are not taken into account in this design.

[0008] The object of the present disclosure is to provide a drive device for a human-powered vehicle that appropriately controls an electric motor with respect to the reverse rotation of a crank. This object is achieved by a drive device for a human-powered vehicle having the features of main claim 1. The object is further achieved by a drive device for a human-powered vehicle having the features of dependent claim 13.

[0009] A propulsion device for a human-powered vehicle according to a first aspect of the present disclosure comprises an electric motor and a controller. The electric motor is configured to rotate in a first direction and assist the propulsion of a human-powered vehicle when a crank is rotating forward, and to receive a driving force from the crank and rotate in a second direction when the crank is rotating backward. The second direction of rotation is opposite to the first. The controller is configured to control the electric motor to generate a torque in the second direction of rotation in at least one of the states in which the crank is rotating backward and in a state in which a human driving force is applied to the crank, causing it to rotate backward.

[0010] With the drive mechanism of a human-powered vehicle, as described in the first aspect, the electric motor, when the user turns the crank backwards, generates torque in the direction in which the electric motor is rotated by the human power transmitted through the crank. This limits the energy output of the electric motor. Additionally, when the user turns the crank backwards, the crank rotates smoothly.

[0011] According to a second aspect of the present disclosure, the drive device of a human-powered vehicle according to the first aspect further comprises an output section which is arranged to rotate integrally with the crank.

[0012] In the case of a human-powered vehicle, as described in the second aspect, the reverse rotation of the crank turns the output section backward. For example, a coaster brake is activated by turning the crank backward.

[0013] According to a third aspect of the present disclosure, the drive device of a human-powered vehicle according to the first or second aspect further comprises a first detector which is configured to detect the torque applied, caused or exerted on the crank.

[0014] According to the third aspect, the drive device of a human-powered vehicle captures a torque applied to the crank in a suitable manner.

[0015] According to a fourth aspect of the present disclosure, the drive device of a human-powered vehicle according to the second aspect further comprises a first detector configured to detect a torque applied to or induced in the crank. The first detector is provided on a transmission path for human power between a crankshaft and the output section. The drive device of a human-powered vehicle according to the fourth aspect detects a torque applied to the crank in a suitable manner.

[0016] According to a fifth aspect of the present disclosure, the drive device of a human-powered vehicle is arranged according to the third or fourth aspect such that, in a case where the torque detected by the first detector has a negative value, the controller controls the electric motor so that the value of the torque detected by the first detector approaches zero.

[0017] Using the drive mechanism of a human-powered vehicle according to the fifth aspect, the user turns the crank slightly backwards.

[0018] According to a sixth aspect of the present disclosure, the drive device of a human-powered vehicle is arranged according to one of the first to fifth aspects such that the controller controls a rotational speed of the electric motor.

[0019] According to the sixth aspect, the electric motor is controlled by the speed control in the drive device of a human-powered vehicle.

[0020] According to a seventh aspect of the present disclosure, the drive device of a human-powered vehicle is arranged according to one of the first to sixth aspects such that the controller controls the torque of the electric motor.

[0021] According to the seventh aspect, the electric motor is controlled by torque control in the drive device of a human-powered vehicle.

[0022] According to an eighth aspect of the present disclosure, the drive device of a human-powered vehicle according to the first aspect further includes an output section which is arranged to rotate independently of the crank.

[0023] According to the eighth aspect, the rotation of the crank is not transferred to the output section of a human-powered vehicle's drive device.

[0024] According to a ninth aspect of the present disclosure, the drive device of a human-powered vehicle is arranged according to one of the first to eighth aspects such that the controller controls the electric motor in such a way that, in a state in which the crank is turning backwards, the torque of the electric motor in the second direction of rotation is within a predetermined range.

[0025] According to the ninth aspect, the drive device of a human-powered vehicle limits the torque of the electric motor in the second direction of rotation to the predetermined range.

[0026] According to a tenth aspect of the present disclosure, the drive device of a human-powered vehicle is arranged according to the ninth aspect such that the predetermined range is a range in which the crank is not turned backwards exclusively by the driving force of the electric motor.

[0027] The propulsion device of a human-powered vehicle according to the tenth aspect limits a situation in which the crank is turned backwards exclusively by the driving force of the electric motor.

[0028] According to an eleventh aspect of the present disclosure, the drive device of a human-powered vehicle is arranged according to one of the first to eighth aspects such that the controller controls the electric motor in a reverse direction according to the acceleration of the crank.

[0029] According to the eleventh aspect, the drive device of a human-powered vehicle controls the electric motor appropriately in a case where the user turns the crank backwards.

[0030] According to a twelfth aspect of the present disclosure, the drive device of a human-powered vehicle is arranged according to the eleventh aspect such that the controller controls the electric motor according to the acceleration of the crank immediately after the start of the reverse rotation of the crank.

[0031] According to the twelfth aspect, the drive device of a human-powered vehicle controls the electric motor in a suitable manner, particularly in a case where the user pedals and turns the crank backwards.

[0032] According to a thirteenth aspect of the present disclosure, the drive device of a human-powered vehicle is arranged according to the twelfth aspect such that the controller controls the electric motor in such a way that the torque in the second direction of rotation decreases in accordance with at least one of the rotational magnitude of the crank in the reverse direction of rotation and a time elapsed since the beginning of the reverse direction of rotation.

[0033] According to the thirteenth aspect, the drive device of a human-powered vehicle controls the electric motor appropriately in a case where the user turns the crank backwards.

[0034] According to a fourteenth aspect of the present disclosure, the drive device of a human-powered vehicle is arranged according to one of the first to thirteenth aspects such that, in a case where the crank stops turning backwards, the controller controls the electric motor so that no torque is generated in the second direction of rotation.

[0035] With the drive device of a human-powered vehicle according to the fourteenth aspect, in a state in which the reverse rotation of the crank is stopped, the exertion of a force on the crank by the motor to rotate the crank in the reverse direction is limited.

[0036] A propulsion device for a human-powered vehicle according to a fifteenth aspect of the present disclosure comprises an electric motor and a controller. The electric motor is configured to rotate in a first direction and assist the propulsion of a human-powered vehicle in a case where a crank rotates forward, and to rotate the crank backward by rotating it in a second direction opposite to the first. The controller rotates the electric motor in the second direction to rotate a crank arm backward into a predetermined rotational position or to rotate the crank arm backward by a predetermined angle.The predetermined rotation position and angle are modifiable according to at least one angle of the human-powered vehicle, information relating to a past stop position of the crank arm, and a setting performed by a user.

[0037] Using the drive mechanism of a human-powered vehicle according to the fifteenth aspect, the electric motor turns the crank backwards to move the crank arm into a suitable position.

[0038] According to a sixteenth aspect of the present disclosure, the propulsion device of a human-powered vehicle is arranged according to the fifteenth aspect such that the angle of the human-powered vehicle includes a gradient angle of the human-powered vehicle.

[0039] According to the sixteenth aspect, the drive device of a human-powered vehicle moves the crank arm into a suitable position according to the incline angle of the human-powered vehicle.

[0040] According to a seventeenth aspect of the present disclosure, the drive device of a human-powered vehicle is arranged according to the fifteenth or sixteenth aspect such that in at least one of a case in which the crank rotates backwards and in a case in which an actuating section is actuated, the controller rotates the electric motor in the second direction of rotation.

[0041] With the drive device of a human-powered vehicle according to the seventeenth aspect, in a case where the user intends to turn the crank arm backwards, the crank arm is turned backwards.

[0042] According to an eighteenth aspect of the present disclosure, the propulsion device of a human-powered vehicle further comprises, according to aspects fifteen to seventeen, a second detector configured to detect the angle of the human-powered vehicle.

[0043] The angle of the human-powered vehicle is appropriately measured using the propulsion device of a human-powered vehicle according to the eighteenth aspect.

[0044] According to a nineteenth aspect of the present disclosure, the drive device of a human-powered vehicle, as described in aspects one through eighteen, further comprises a third detector configured to detect the rotational position of a crank arm. The drive device of a human-powered vehicle, as described in the nineteenth aspect, detects the rotational position of the crank arm in a suitable manner.

[0045] With the drive device of a human-powered vehicle according to the present disclosure, the electric motor is controlled in a suitable manner with respect to the reverse rotation of the crank. Fig. Figure 1 is a side view of a human-powered vehicle, which includes a first embodiment of a propulsion device of a human-powered vehicle. Fig. Figure 2 is a block diagram showing the electrical configuration of the human-powered vehicle. Fig. Figure 3 is a block diagram showing a power transmission path of the human-powered vehicle. Fig. Figure 4 is a flowchart showing an example of control performed on an electric motor by a controller. Fig. Figure 5 is a flowchart showing an example of control performed on the electric motor by the controller. Fig. Figure 6 is a flowchart showing an example of control performed on the electric motor by the controller. Fig. Figure 7 is a block diagram showing the electrical configuration of a human-powered vehicle, which includes a second embodiment of a propulsion device of a human-powered vehicle. Fig. Figure 8 is a flowchart showing an example of control performed on the electric motor by the controller. Fig. Figure 9 is a block diagram showing a power transmission path of a human-powered vehicle, which includes a third embodiment of a propulsion device of a human-powered vehicle. Fig. Figure 10 is a block diagram showing the electrical configuration of the human-powered vehicle. Fig. Figure 11 is a flowchart showing an example of control performed on the electric motor by the controller. Fig. Figure 12 is a flowchart showing an example of control performed on the electric motor by the controller. Fig. Figure 13 is a flowchart showing an example of control performed on the electric motor by the controller. Fig. Figure 14 is a flowchart showing an example of control performed on the electric motor by the controller. First embodiment

[0046] A first embodiment of a drive device for a human-powered vehicle 30 is now described with reference to the Fig. 1 to 6 are described. In the following description, the drive device 30 of a human-powered vehicle is simply referred to as the drive device 30. The drive device 30 is provided on a human-powered vehicle 10. The human-powered vehicle 10 is a vehicle that is propelled by at least human power. The number of wheels in the human-powered vehicle 10 is not limited. The human-powered vehicle 10 includes, for example, a unicycle and a vehicle with three or more wheels. The human-powered vehicle 10 includes, for example, various types of bicycles, such as a mountain bike, a racing bike, a city bike, a cargo bike, a recumbent bike, and an electrically assisted bicycle (e-bike).In the embodiments described below, the human-powered vehicle 10 refers to a bicycle.

[0047] As in Fig. As shown in Figure 1, the human-powered vehicle 10 includes a crank 12 and a drive wheel 14. The human-powered vehicle 10 also includes a frame 16. Human power is supplied to, or rather, input into, the crank 12. The crank 12 includes the crankshaft 12A, which is configured to rotate relative to the frame 16, and crank arms 12B, which are provided at axially opposite ends of the crankshaft 12A. A pedal 18 is coupled to each of the crank arms 12B. The drive wheel 14 is driven according to the rotation of the crank 12. The drive wheel 14 is supported by the frame 16. The crank 12 and the drive wheel 14 are coupled by a drive mechanism 20. The drive mechanism 20 includes a first rotating body 22, which is coupled to the crankshaft 12A. The first rotating body 22 contains a sprocket, a pulley or a bevel gear.The drive mechanism 20 further comprises a coupling element 24 and a second rotating body 26. The coupling element 24 transmits a rotational force from the first rotating body 22 to the second rotating body 26. The coupling element 24 comprises, for example, a chain, a belt, or a shaft.

[0048] The second rotating body 26 is coupled to the drive wheel 14. The second rotating body 26 includes a sprocket, a pulley, or a bevel gear. Preferably, a one-way coupling 28 is provided between the second rotating body 26 and the drive wheel 14. The one-way coupling 28 is configured to allow forward rotation of the drive wheel 14 when the second rotating body 26 is rotating forward, and to prevent reverse rotation of the drive wheel 14 when the second rotating body 26 is rotating backward.

[0049] The human-powered vehicle 10 comprises a front wheel and a rear wheel. The front wheel is coupled to the frame 16 via a front fork 16A. A handlebar 10H is connected to the front fork 16A via a stem 16B. In the embodiments described below, the drive wheel 14 refers to the rear wheel. However, the front wheel can also be the drive wheel 14.

[0050] As in Fig. As shown in Figure 2, the human-powered vehicle 10 includes the drive device 30 and a battery 32. An example of the drive device 30 is a drive unit that assists the propulsion of the human-powered vehicle 10. The drive device 30 is, for example, installed on the frame 16 of the human-powered vehicle 10. As shown in Figure 2, the human-powered vehicle 10 is equipped with a drive unit that assists the propulsion of the human-powered vehicle 10. Fig. 2 and Fig. As shown in Figure 3, the drive device 30 comprises an electric motor 34 and a controller 36. The electric motor 34 is configured to rotate in a first direction when the crank is turning forward and to assist the propulsion of the human-powered vehicle 10. The electric motor 34 is configured to receive a driving force from the crank 12 when the crank 12 is turning backward and to rotate in a second direction opposite to the first. The controller 36 is configured to control the electric motor 34 such that a torque in the second direction of rotation is generated in at least one of the conditions in which the crank 12 is turning backward and in a condition in which a human driving force is being applied to the crank 12, causing the crank 12 to rotate backward.

[0051] The electric motor 34 is designed to transmit rotation to a power transmission path for human propulsion, extending from the pedals 18 to the second rotating body 26. One example of the electric motor 34 incorporates a brushless motor. The electric motor 34 is mounted on the frame 16 of the human-powered vehicle 10. In the present embodiment, the electric motor 34 is coupled to the power transmission path between the crankshaft 12A and the first rotating body 22. A one-way clutch 35 is provided on the power transmission path between the electric motor 34 and the crankshaft 12A and is configured such that, in a forward-rotating case, the rotational force of the crankshaft 12A does not rotate the electric motor 34. The one-way clutch 35 comprises a ratchet clutch, a roller clutch, or a clamping clutch.

[0052] The drive device 30 includes an output section 38 that rotates integrally with the crank 12. The driving force of the electric motor 34 is transmitted to the output section 38. The output section 38 is arranged, for example, such that its axis of rotation is aligned with the axis of rotation of the crankshaft 12A, and such that the output section 38 surrounds at least one section of the crankshaft 12A around its axis of rotation. Preferably, the drive device 30 further includes a speed reduction unit 37, which reduces the rotational speed of the electric motor 34 and outputs the rotation. The speed reduction unit 37 is coupled to the electric motor 34 and the output section 38. Preferably, a one-way coupling 35 is connected between the speed reduction unit 37 and the output section 38.The one-way coupling 35 can also be integrated into a section of the speed reduction unit 37 or arranged between the speed reduction unit 37 and the electric motor 34. At least one of the one-way coupling 35 and the speed reduction unit 37 can be omitted.

[0053] As in Fig. As shown in Figure 3, in a case where the crank 12 rotates forward, the rotational force is transmitted to the drive wheel 14 via the drive mechanism 20. In a case where the rotational force of the crank 12 is transmitted to the drive wheel 14 in the forward direction of rotation and the electric motor 34 assists the propulsion of the human-powered vehicle 10, the driving force of the electric motor 34 is added to the human driving force at output section 38.

[0054] In the case where the crank 12 rotates in reverse, the torque is not transmitted to the drive wheel 14 via the one-way clutch 28, which is provided between the second rotating body 26 and the drive wheel 14. In the case where the crank 12 rotates in reverse, the torque is transmitted to the electric motor 34 via the output section 38, the one-way clutch 35 and the speed reduction unit 37.

[0055] The drive device 30 further comprises a drive circuit 40. The drive circuit 40 includes an inverter circuit. Preferably, the electric motor 34 and the drive circuit 40 are mounted on the same housing. The drive circuit 40 controls the power supplied to the electric motor 34 by the battery 32. The drive circuit 40 is connected to the controller 36, enabling wired or wireless communication. The drive circuit 40 is configured to communicate with the controller 36, for example, via serial communication. The drive circuit 40 drives the electric motor 34 according to a control signal from the controller 36. The drive circuit 40 can be integrated into the controller 36. The output section 38, the one-way coupling 35, and the speed reduction unit 37 are mounted on the housing where the electric motor 34 and the drive circuit 40 are located.

[0056] The battery 32 contains, for example, a lithium-ion battery. The battery 32 contains one or more battery cells. The battery cells contain a rechargeable battery. The battery 32 supplies energy to other electrical components provided on the human-powered vehicle 10 and electrically connected to the battery 32 by wires. Examples of such electrical components are the electric motor 34 and the controller 36. The battery 32 is connected to the controller 36 so that wired or wireless communication takes place. The battery 32 is configured to communicate with the controller 36, for example, via power line communication (PLC). The battery 32 can be mounted externally on the frame 16 or at least partially housed within the frame 16.

[0057] The drive device 30 further comprises a first detector 42, which is configured to detect a torque applied to the crank 12. The first detector 42 is located on the transmission path for the human driving force between the crankshaft 12A of the crank 12 and the output section 38.

[0058] The first detector 42 contains a strain sensor or a magnetostriction sensor. The strain sensor includes a strain gauge. In a case where the first detector 42 contains a strain sensor, the strain sensor is, for example, located on the outer circumferential section of a rotating body included in the power transmission path. In one example, the strain sensor is located on the crankshaft 12A. In a case where the first detector 42 contains a magnetostriction sensor, the magnetostriction sensor is, for example, located around a rotating body included in the power transmission path. The first detector 42 can contain a wireless or wired communicator. The communicator of the first detector 42 is configured to communicate with the controller 36. The first detector 42 transmits a signal to the controller 36 corresponding to the torque applied to the crankshaft 12A.In the present embodiment, when a human driving force is applied to the crank 12, causing the crank 12 to rotate forward, the first detector 42 outputs a voltage higher than a reference value, or data with a value greater than the reference value, as the signal corresponding to the torque applied to the crank 12. When a voltage higher than the reference value, or data with a value greater than the reference value, is received by the first detector 42, the controller 36 determines that the torque detected by the first detector 42 has a positive value.In a case where a human driving force is applied to the crank 12, causing it to rotate backwards, the first detector 42 outputs a voltage lower than the reference value, or data with a value smaller than the reference value, as the signal corresponding to the torque applied to the crank 12. When the voltage below the reference value or the data with a value smaller than the reference value is received, the controller 36 determines that the torque detected by the first detector 42 has a negative value.

[0059] The controller 36 contains an arithmetic processing device that executes predetermined control programs. The arithmetic processing device includes, for example, a central processing unit (CPU) or a microprocessing unit (MPU). The controller 36 can contain one or more microcomputers. The controller 36 can contain multiple arithmetic processing devices located at separate locations. The drive device 30 also includes a memory 44. The memory 44 is electrically connected to the controller 36. The memory 44 contains information that is used in different control programs and different control processes. The memory 44 includes, for example, non-volatile memory and volatile memory. The controller 36 and the memory 44 are, for example, provided on the housing on which the electric motor 34 is provided.

[0060] In a case where the crank 12 rotates forward, the controller 36 controls the electric motor 34 in a first control state. In a case where the crank 12 rotates backward, and in a case where a human driving force is exerted on the crank 12 so that the crank 12 rotates backward, the controller 36 controls the electric motor 34 in a second control state.

[0061] In the present embodiment, in the first control state, the controller 36 controls the electric motor 34 according to the human driving force supplied to the crank 12. In the first control state, the controller 36 controls the electric motor 34 such that the ratio of the support force of the electric motor 34 to the human driving force supplied to the crank 12 is set to a predetermined ratio. The predetermined ratio can be a fixed value, a value that changes according to the human driving force, a value that changes according to the vehicle speed, or a value that changes according to the rotational speed of the crank 12. The human driving force includes a torque or power (watts) of the human driving force.The predetermined ratio is, for example, a ratio of the torque of the electric motor 34's assist force to the torque of the human propulsion force applied to the human-powered vehicle 10. The predetermined ratio is, for example, a power ratio (watts) of the electric motor 34's assist force to the power (watts) of the human propulsion force applied to the crank 12. The power of the human propulsion force is obtained by multiplying the torque of the human propulsion force applied to the crank 12 by the crank's rotational speed.In a case where a driving force of the electric motor 34 is entered or supplied to the human driving force transmission path via a speed reduction unit, a driving force output by the speed reduction unit is used as the support force of the electric motor 34.

[0062] In the present embodiment, in the second control state, the controller 36 controls the electric motor 34 to generate a torque in the second direction of rotation. Fig. Figure 4 shows an example of a control procedure executed by the controller 36 on the electric motor 34 to generate torque in the second direction of rotation. In a first example, when the controller 36 is powered by the battery 32, the controller 36 starts the process and proceeds with step S11 in the Fig. The flowchart shown in section 4 continues. Until the power supply stops, even if that is in Fig. When the flowchart shown in section 4 ends, the controller 36 proceeds to step S11 and repeats the process in a predetermined cycle.

[0063] As in Fig. As shown in Figure 4, in step S11, the controller 36 determines whether the crank 12 rotates backwards or not. The controller 36 determines the direction of rotation of the crank 12 according to the direction of rotation of the electric motor 34. The electric motor 34 contains at least one magnetic pole detector and one rotary position detector, which detects the rotational position of a rotor of the electric motor 34. The controller 36 determines the direction of rotation of the electric motor 34 according to the detection result of the magnetic pole detector or the rotary position detector. The magnetic pole detector contains a sensor that detects the magnetic pole of a magnet of the rotor of the electric motor 34. The magnetic pole detector contains, for example, a Hall effect sensor. The rotary position detector can be configured to contain, for example, a rotation indicator and an optical sensor.

[0064] In a case where the controller 36 determines in step S11 that the crank 12 is not rotating backwards, the controller 36 proceeds to step S12. In step S12, the controller 36 determines whether a human driving force is being applied to the crank 12, causing it to rotate backwards. In a case where the torque detected by the first detector 42 has a negative value, the controller 36 determines that a human driving force is being applied to the crank 12, causing it to rotate backwards.

[0065] In a case where the controller 36 determines in step S12 that no human driving force is being applied to the crank 12 to turn it backwards, the controller 36 temporarily terminates the process. In this case, the controller 36 is configured to control the electric motor 34, for example, in the first control state.

[0066] In a case where, in step S11, the controller 36 determines that the crank 12 rotates backwards, or in step S12 determines that a human driving force is applied to the crank 12 so that the crank 12 rotates backwards, the controller 36 proceeds to step S13. In step S13, the controller 36 controls the electric motor 34 to generate a torque in the second direction of rotation and proceeds to step S14.

[0067] In step S14, the controller 36 determines whether the reverse rotation of the crank 12 has stopped or not. In one example, the controller 36 performs the determination of step S14 according to the rotation state of the electric motor 34. If the rotation of the electric motor 34 has stopped, the controller 36 determines that the reverse rotation of the crank 12 has stopped.

[0068] In step S14, if the controller 36 determines that the reverse rotation of the crank 12 has not stopped, the controller 36 proceeds to step S13. In step S14, if the controller 36 determines that the reverse rotation of the crank 12 has stopped, the controller 36 proceeds to step S15. In step S15, the controller 36 determines whether a human driving force is being applied to the crank 12, causing it to rotate backward. Similarly, in step S12, if the torque detected by the first detector 42 has a negative value, the controller 36 determines that a human driving force is being applied to the crank 12, causing it to rotate backward.

[0069] In a case where, in step S15, the controller 36 determines that a human driving force is being applied to the crank 12, causing the crank 12 to rotate backwards, the controller 36 proceeds to step S13. In a case where, in step S15, the controller 36 determines that no human driving force is being applied to the crank 12, causing it to rotate backwards, the controller 36 proceeds to step S16. In step S16, the controller 36 controls the electric motor 34 to prevent it from generating torque in the second direction of rotation and temporarily terminates the process. In step S16, the controller 36 may deactivate the electric motor 34. In at least one of steps S12 and S15 in the Fig. In the process shown in Figure 4, if the torque detected by the first detector 42 has a negative value and the value is less than or equal to a predetermined value, the controller 36 can determine that a human driving force is being applied to the crank 12, causing the crank 12 to rotate backwards. Step S15 can be derived from the in Fig. The process shown in section 4 can be omitted. One of steps S11 and S12 can be taken from the one shown in section 4. Fig. The process shown in step 4 can be omitted.

[0070] Fig. Figure 5 is an example of a flowchart showing a detailed procedure for the operation of step S13. In a case where the torque detected by the first detector 42 has a negative value, the controller 36 controls the electric motor 34 so that the value of the torque detected by the first detector 42 approaches zero.

[0071] In a case where the controller 36 determines in step S12 that a human driving force is being applied to the crank 12, causing the crank 12 to rotate backwards, the torque detected by the first detector 42 has a negative value. After the controller 36 receives a torque applied to the crank 12 in step S21, the controller 36 proceeds to step S22. The controller 36 receives the torque detected by the first detector 42 as the torque applied to the crank 12.

[0072] In step S22, the controller 36 controls the electric motor 34 such that the torque value detected by the first detector 42 approaches zero (0). In a first example of step S22, the controller 36 controls the torque of the electric motor 34. The controller 36 controls the torque of the electric motor 34 in the second direction of rotation according to the relationship between the torque of the electric motor 34 in the second direction of rotation and the difference between the value of the torque detected by the first detector 42 and zero. In one example, the controller 36 controls the electric motor 34 such that as the difference between the value of the torque detected by the first detector 42 and zero increases, the torque of the electric motor 34 in the second direction of rotation also increases.The relationship between the torque of the electric motor 34 in the second direction of rotation and the difference between the torque value detected by the first detector 42 and zero can be stored in memory 44, for example, as a graph or a relational expression. Instead of steps S21 and S22, the controller 36 can be configured to rotate the electric motor 34 in the second direction of rotation with a predetermined torque. In a second example of step S22, the controller 36 controls the rotational speed of the electric motor 34. The controller 36 controls the rotational speed of the electric motor 34 so that the torque value detected by the first detector 42 approaches zero. In one example, the controller 36 controls the rotational speed of the electric motor 34 according to the difference between the torque value detected by the first detector 42 and zero.After the controller 36 drives the electric motor 34, the controller 36 again receives a torque signal, which is detected by the first detector 42. The controller 36 increases the rotational speed of the electric motor 34 so that the value of the torque received again approaches zero. Whenever a torque signal is received from the first detector 42, the controller 36 can control the rotational speed of the electric motor 34 so that, for example, the rotational speed of the electric motor 34 increases at a fixed rate or by a fixed value. Instead of steps S21 and S22, the controller 36 can be configured to rotate the electric motor 34 in the second direction of rotation at a predetermined rotational speed.

[0073] Fig. Figure 6 is an example of a flowchart showing a detailed procedure for the operation of step S13. For example, in a state where the crank is turning backwards, the controller 36 controls the electric motor 34 so that the torque of the electric motor 34 in the second direction of rotation is within a predetermined range.

[0074] In step S31, the controller 36 controls the electric motor 34 such that the torque of the electric motor 34 in the second direction of rotation is within the predetermined range, and the controller 36 then proceeds to step S14. Preferably, the predetermined range is a range in which the crank 12 is not rotated backward by the driving force of the electric motor 34. In step S31, the controller 36 can control either the torque or the rotational speed of the electric motor 34.

[0075] In the present embodiment, in a case where the user turns the crank 12 backwards, the drive device 30 prevents unwanted regenerative energy generation by the electric motor 34 and charging of the battery 32 by the electric motor 34. Second embodiment

[0076] A second embodiment of a drive device 30 is now described with reference to the Fig. 7 and Fig. 8 described. The drive device 30 of the second embodiment differs mainly from the drive device 30 of the first embodiment in that it also includes a third detector 46 and in the process of controlling the electric motor 34, so that the electric motor 34 generates a torque in the second direction of rotation. In the following description, the components that are identical to the corresponding components of the first embodiment are designated with the same reference numerals. Such components are not described in detail.

[0077] As in Fig. As shown in Figure 7, the drive device 30 further includes the third detector 46, which detects the rotational position of the crank arms 12B of the crank 12. In one example, the third detector 46 detects an angle of rotation of the crank arms 12B. The third detector 46 is mounted on the frame 16 or on the housing on which the electric motor 34 is provided. The third detector 46 includes a magnetic sensor that outputs a signal corresponding to the strength of a magnetic field. In one example, a ring-shaped magnet is provided on the crankshaft 12A or on the power transmission path between the crankshaft 12A and the first rotating body 22, the magnetic field of which changes in the circumferential direction. The use of a magnetic sensor that outputs a signal corresponding to the strength of a magnetic field enables the detection of both the rotational speed of the crank 12 and the angle of rotation of the crank arms 12B with the single sensor and simplifies the design and assembly.The third detector 46 detects the rotational speed of the crank 12 in addition to the rotational angle of the crank arms 12B. The third detector 46 is connected to the controller 36, enabling wired or wireless communication. The third detector 46 transmits a signal corresponding to the rotational angle of the crank arms 12B to the controller 36.

[0078] The controller 36 controls the electric motor 34 according to the acceleration of the crank 12 in a reverse direction of rotation. Preferably, the controller 36 controls the electric motor 34 according to the acceleration of the crank immediately after the crank begins to rotate backward. In this case, for example, if the user turns the crank 12 in the reverse direction, the controller 36 is configured to control the electric motor 34 to generate torque in the reverse direction. In a reverse direction, the acceleration of the crank 12 decreases as the rotational speed of the crank 12 increases, either because the crank 12 begins to rotate backward or because the time elapsed since the crank 12 began to rotate backward increases.Preferably, the controller 36 controls the electric motor 34 such that the torque in the second direction of rotation decreases by at least one factor equal to the rotational speed of the crank 12 in the reverse direction and the time elapsed since the reverse rotation of the crank 12 began. In the event that the crank 12 stops rotating in the reverse direction, the controller 36 controls the electric motor 34 to prevent the generation of any torque in the second direction of rotation.

[0079] Fig. Figure 8 shows an example of a control operation performed by the controller 36 on the electric motor 34 to generate torque in the second direction of rotation. In a case where the controller 36 is powered by the battery 32, the controller 36 starts the operation and proceeds to step S41 in the Fig. The flowchart shown in section 8 continues. Until the power supply stops, even if that is in Fig. When the flowchart shown in section 8 ends, the controller 36 continues with step S41 and executes the process repeatedly in a predetermined cycle.

[0080] In step S41, the controller 36 determines whether the crank 12 begins to rotate backwards or not. The controller 36 determines whether the crank 12 begins to rotate backwards or not based on the rotational position of the crank arms 12B, which is detected by the third detector 46. In a first example of determining step S41, the controller 36 determines a change in the rotational angle of the crank 12 detected by the third detector 46, and in a case where the rotational position of the crank arms 12B changes in the reverse direction of rotation, the controller 36 determines that the crank 12 begins to rotate backwards.In a second example of step S41, the controller 36 detects the rotation state of the electric motor 34 with the magnetic pole detector or the rotation position detector of the electric motor 34, and in a case where the electric motor 34 begins to rotate in the second direction of rotation, the controller 36 determines that the crank 12 begins to rotate backwards.

[0081] If, in step S41, controller 36 determines that crank 12 will not begin to rotate backwards, controller 36 temporarily terminates the process. If, in step S41, controller 36 determines that crank 12 will begin to rotate backwards, controller 36 proceeds to step S42.

[0082] After the controller 36 receives the acceleration of the crank 12 in the reverse direction of rotation in step S42, the controller 36 proceeds to step S43. The controller 36 receives the acceleration of the crank 12 in the reverse direction of rotation based on the rotational position of the crank 12 detected by the third detector 46. In one example, the controller 36 obtains the acceleration of the crank 12 in the reverse direction of rotation by differentiating a rotational velocity calculated based on the rotational position of the crank arms 12B detected by the third detector 46. After the controller 36 has controlled the electric motor 34 according to the acceleration of the crank 12 in the reverse direction of rotation in step S43, the controller 36 proceeds to step S44.

[0083] In an example from step S43, the controller 36 controls the torque of the electric motor 34 according to the acceleration of the crank 12 in the reverse direction of rotation. In another example, as the acceleration of the crank 12 in the reverse direction increases, the controller 36 controls the electric motor 34 to increase its torque. The memory 44 can store the relationship between the acceleration of the crank 12 in the reverse direction and the torque of the electric motor 34, for example, as a graph or as a relational expression. In step S44, the controller 36 controls the electric motor 34 so that the torque in the second direction of rotation decreases by at least one factor of the rotational speed of the crank 12 in the reverse direction and the time elapsed since the start of the reverse rotation of the crank. The controller 36 then proceeds to step S45.

[0084] In a first example from step S44, the controller 36 receives the rotational value of the crank 12 in the reverse direction. This rotational value is, for example, the value of the crank 12 in the reverse direction from the point at which it is determined in step S41 that the crank 12 begins to rotate in reverse. The controller 36 calculates this rotational value based on the crank 12's position in step S41 and its position in step S44. The controller 36 then controls the torque of the electric motor 34 according to the relationship between the rotational value of the crank 12 in the reverse direction and the torque of the electric motor 34 in the second direction of rotation.In one example, the controller 36 controls the electric motor 34 such that the torque of the electric motor 34 decreases in the second direction of rotation when the rotational speed of the crank 12 increases in the reverse direction. The memory 44 can store the relationship between the rotational speed of the crank 12 in the reverse direction and the torque of the electric motor 34 in the second direction of rotation, for example, as a graph or a relational expression.

[0085] In a second example from step S44, the controller 36 receives the time elapsed since the crank 12 began rotating backwards. This time is, for example, the time that has passed since it was determined in step S41 that the crank 12 began rotating backwards. The controller 36 contains, for example, a timer. In a case where the controller 36 determines in step S41 that the crank 12 has begun rotating backwards, the controller 36 starts counting with the timer. In step S44, the controller 36 receives the count from the timer. The controller 36 controls the torque of the electric motor 34 according to the relationship between the time elapsed since the crank 12 began rotating backwards and the torque of the electric motor 34 in the second direction of rotation.In one example, the controller 36 controls the electric motor 34 such that the torque of the electric motor 34 in the second direction of rotation decreases as the time elapsed since the start of the reverse rotation of the crank 12 increases. The memory 44 can store the relationship between the time elapsed since the start of the reverse rotation of the crank 12 and the torque of the electric motor 34 in the second direction of rotation, for example, as a graph or a relational expression.

[0086] In step S45, the controller 36 determines whether the reverse rotation of the crank 12 has stopped or not. The determination of step S45 is the same as the determination of step S14 in Fig. 4.

[0087] If, in step S45, the controller 36 determines that the reverse rotation of the crank 12 has not stopped, the controller 36 proceeds to step S44. In this case, the controller 36 receives either the rotational speed of the crank 12 in the reverse direction or the time elapsed since the reverse rotation of the crank 12 began. In step S44, the controller 36 controls the torque of the electric motor 34 according to this newly obtained rotational speed of the crank 12 in the reverse direction or the newly obtained time elapsed since the reverse rotation of the crank 12 began. If, in step S45, the controller 36 determines that the reverse rotation of the crank 12 has stopped, the controller 36 proceeds to step S46. In step S46, the controller 36 controls the electric motor 34 to prevent it from generating torque in the reverse direction and temporarily terminates the process.In step S46, the controller 36 can deactivate the electric motor 34. Third embodiment

[0088] A third embodiment of the drive device 30 is now described with reference to the Fig. Sections 9 to 14 describe the drive device 30 of the third embodiment. It differs from the drive device 30 of the first embodiment primarily in that it still includes a one-way coupling 48 and a second detector 50, and in the control mechanism implemented on the electric motor 34 in the second direction of rotation. In the following description, components identical to the corresponding components of the first embodiment are designated with the same reference numerals. Such components are not described in detail.

[0089] The drive device 30 includes an output section 38 which is configured to rotate independently of the crank 12. In one example, as shown in Fig. As shown in Figure 9, the one-way clutch 48 is provided on the power transmission path between the crankshaft 12A and the output section 38. The one-way clutch 48 is configured to allow forward rotation of the first rotating body 22 when the crank 12 is rotating forward, and to prevent reverse rotation of the first rotating body 22 when the crank 12 is rotating backward. The one-way clutch 48 includes a ratchet clutch, a roller clutch, or a clamping clutch. As shown in Fig. As shown in Figure 10, the drive device 30 includes the second detector 50, which detects an angle of the human-powered vehicle 10. The angle of the human-powered vehicle 10 includes a gradient angle of the human-powered vehicle 10.

[0090] The second detector 50 detects at least one of the angle of inclination of the human-powered vehicle 10, the angle of tilt of the human-powered vehicle 10 relative to the road surface on which it travels, and the gradient of the road surface on which it travels. The second detector 50 is connected to the controller 36, enabling wired or wireless communication. The second detector 50 includes an inclination sensor. The inclination sensor is designed to be attached to the human-powered vehicle 10.

[0091] Thus, the angle of the human-powered vehicle 10 is easily detected. The tilt sensor is, for example, attached to the frame 16 or the drive unit 30. The tilt sensor includes, for example, at least one accelerometer and one gyroscope. The tilt sensor can detect the angle of the human-powered vehicle 10 based on position information of the human-powered vehicle 10 and map information. In this case, the tilt sensor includes a GPS (Global Positioning System) receiver and is configured to connect to the internet.The tilt sensor receives at least one of the following data from GPS and the internet: map data of the location where the human-powered vehicle 10 is traveling, the gradient of the road surface on which the human-powered vehicle 10 is traveling, and the condition of the road surface on which the human-powered vehicle 10 is traveling. In a case where the angle of the human-powered vehicle 10 is determined based on the position information of the human-powered vehicle 10 and the map information, the memory 44 can store the map data, so that the tilt sensor does not need to be connected to the internet.

[0092] The drive device 30 comprises the electric motor 34 and the controller 36. The electric motor 34 is configured to rotate in the first direction to assist the propulsion of the human-powered vehicle 10 when the crank 12 is rotating forward, and to rotate in the second direction, opposite to the first, to rotate the crank 12 backward. The controller 36 rotates the electric motor 34 in the second direction so that the crank arms 12B of the crank 12 are rotated backward to a predetermined rotational position, or so that the crank arms 12B are rotated backward to a predetermined angle.The predetermined rotation position and angle can be modified according to at least one piece of information related to the angle of the human-powered vehicle 10, to a previous stop position of the crank arms 12B, and the user's setting. For example, the predetermined rotation position is a position of the crank arms 12B that allows the user to easily begin pedaling. In one example, the predetermined rotation position is where the crank arms 12B are rotated 90° from top and bottom dead center. The predetermined rotation angle is, for example, in a range of 20° to 90°.

[0093] The human-powered vehicle 10 includes an actuating section 52. The actuating section 52 is, for example, provided on the handlebar 10H. The actuating section 52 is configured, for example, to actuate the start of rotation of the electric motor 34 in the second direction of rotation. The actuating section 52 is connected to the controller 36, enabling wired or wireless communication. The actuating section 52 includes, for example, a push button.

[0094] In at least one case where the crank 12 is turned backwards, and in one case where the actuating section 52 is actuated, the controller 36 rotates the electric motor 34 in the second direction of rotation.

[0095] Fig. Figure 11 shows an example of a control procedure performed by the controller 36 to rotate the crank arms 12B into the predetermined rotational position.

[0096] In step S51, the controller 36 determines whether or not the actuating section 52 is actuated. If, in step S51, the controller 36 determines that the actuating section 52 is not actuated, the controller 36 proceeds to step S52. In step S52, the controller 36 determines whether or not the crank 12 is turned backward. The determination in step S52 is the same as the determination in step S11. Fig. 4.

[0097] In a case where the controller 36 determines in step S52 that the crank 12 is not turned backwards, the controller 36 temporarily terminates the process.

[0098] In a case where the controller 36 determines in step S51 that the actuating section 52 is actuated, or in step S52 determines that the crank 12 is rotated backwards, the controller 36 proceeds to step S53. In step S53, the controller 36 controls the electric motor 34 so that the crank arms 12B are rotated backwards into the predetermined rotational position and temporarily terminates the operation. In one example, the controller 36 rotates the electric motor 34 in the second direction of rotation to rotate the crank arms 12B backwards. The controller 36 rotates the electric motor 34 in the second direction of rotation until the second detector 50 detects that the crank arms 12B have reached the predetermined rotational position. In a case where the controller 36 determines that the crank arms 12B have reached the predetermined rotational position with the second detector 50, the controller 36 stops the rotation of the electric motor 34 in the second direction of rotation. One of the steps S51 and S52 can be found in the one in . Fig. The process shown in Figure 11 can be omitted. In a case where step S51 is omitted, actuation section 52 can also be omitted.

[0099] Fig. Figure 12 shows an example of a control procedure executed by the controller 36 to rotate the crank arms 12B backwards by the predetermined angle. Each time the user turns the crank 12 in the reverse direction, the controller 36 controls the electric motor 34 so that the crank arms 12B are rotated backwards by the predetermined angle and stopped.

[0100] The in Fig. Step 12, S61, is the same as the one shown in Fig. Step S51, shown in 11. The one in Fig. Step 12, S62, is the same as the one shown in Fig. 11 shown step S62.

[0101] In a case where, in step S61, the controller 36 determines that the actuating section 52 is actuated, or in step S62 determines that the crank 12 is rotated backward, the controller 36 proceeds to step S63. In step S63, the controller 36 controls the electric motor 34 so that the crank arms 12B are rotated backward by the predetermined angle and temporarily terminates the operation. In one example, the controller 36 rotates the electric motor 34 in the second direction of rotation to rotate the crank arms 12B backward. The controller 36 rotates the electric motor 34 in the second direction of rotation until the second detector 50 determines that the crank arms 12B have reached the predetermined angle. In a case where, based on the second detector 50, the controller 36 determines that the crank arms 12B are rotated backward by the predetermined angle, the controller 36 stops the rotation of the electric motor 34 in the second direction of rotation.One of the steps S61 and S62 can be found in the one in . Fig. The process shown in Figure 12 can be omitted. In a case where step S61 is omitted, actuation section 52 can also be omitted.

[0102] Changes to the predetermined rotational position and angle are now made with reference to the Fig. 13 and Fig. 14 described. Fig. 13 is an example of changing the predetermined rotation position. Fig. Figure 14 is an example of changing the predetermined angle. In this example, the drive device 30 is configured to change at least one of the predetermined rotational position and angle. For example, the user can actuate the actuator section 52 to select and change one of the predetermined rotational position and angle.

[0103] As in Fig. As shown in Figure 13, after the controller 36 in step S71 has received at least one piece of information about the angle of the human-powered vehicle 10, one piece of information about a past stop position of the crank arms 12B, and the setting made by the user, the controller 36 proceeds to step S72. In step S72, the controller 36 changes the predetermined rotational position according to at least one piece of information about the angle of the human-powered vehicle 10, the information about a past stop position of the crank arms 12B, and the setting made by the user, and temporarily terminates the process. As shown in Fig. As shown in Figure 14, after the controller 36 has received the angle of the human-powered vehicle 10, the information regarding a past stop position of the crank arms 12B, and the user-defined setting in step S81, the controller 36 proceeds to step S82. In step S82, the controller 36 changes the predetermined angle according to at least one of the angle of the human-powered vehicle 10, a past stop position of the crank arms 12B, and the user-defined setting, and temporarily terminates the process.

[0104] In a case where the predetermined rotational position and angle are changed according to the angle of the human-powered vehicle 10, the predetermined rotational position and angle are changed according to, for example, the incline angle of the human-powered vehicle 10. The controller 36 receives the incline angle of the human-powered vehicle 10 from the second detector 50. The controller 36 changes the predetermined rotational position according to the relationship between the incline angle of the human-powered vehicle 10 and the predetermined rotational position. The controller 36 changes the predetermined angle according to the relationship between the incline angle of the human-powered vehicle 10 and the predetermined angle.Memory 44 stores the relationship between the incline angle of the human-powered vehicle 10 and the predetermined rotational position, for example, as a graph or a relational expression. Memory 44 stores the relationship between the incline angle of the human-powered vehicle 10 and the predetermined angle, for example, as a graph or a relational expression.

[0105] In a case where the predetermined rotational position and angle are changed according to information regarding a past stop position of the crank arms 12B, information regarding the stop position of the crank arms 12B is stored in memory 44 each time the crank arms 12B stop rotating. For example, in a state where the human-powered vehicle 10 is stopped, the controller 36 stores the information regarding the stop position in memory 44 each time the crank arms 12B stop rotating. The controller 36 can change the predetermined rotational position and angle so that, for example, the crank arms 12B are set to the position that has been stopped most frequently in the past.The Controller 36 can change the predetermined rotation position and angle, so that, for example, the crank arms 12B are set to the average value of the past stop positions.

[0106] In a case where the predetermined rotational position and angle are changed according to a setting made by the user, the controller 36 receives information regarding the change in the user's setting. For example, the user operates a bicycle computer provided on the human-powered vehicle 10, a switch, or an external device connected via wired or wireless communication, thereby changing the predetermined rotational position and angle. In another example, the user transmits information regarding a change in the setting of the predetermined rotational position and angle from an external device, such as a smartphone, to the controller 36, and the controller 36 then changes the predetermined rotational position and angle. Modified examples

[0107] The description relating to the embodiments illustrates, without limitation, applicable forms of a propulsion device for a human-powered vehicle according to the present disclosure. The propulsion device for a human-powered vehicle according to the present disclosure is applicable, for example, to modified examples of the embodiments described below and to at least two of the modified examples that do not contradict each other. In the modified examples described below, those elements are designated with the same reference numerals as the corresponding elements of the embodiments. Such elements are not described in detail.

[0108] In the first embodiment, the drive device 30 can further include at least one of the second detector 50, one of the third detector 46, and one of the actuating section 52. The human-powered vehicle 10 can also include the actuating section 52. The drive device 30 can, for example, be configured to be actuated in several control modes, such that at least two of the control modes of the first embodiment, the control mode of the second embodiment, and the control mode of the third embodiment are switched and executed. In the first embodiment, in a case where the drive device 30 includes the third detector 46, the controller 36 can determine, based on the detection result of the third detector 46 in at least one of the steps S11 and S14, whether the crank 12 is turned backward or not.In the first embodiment, in a case where the drive device 30 contains the third detector 46, in step S22 of . Fig. 5. The controller 36 calculates the rotational speed of the crank 12 in the second direction of rotation from the rotational position of the crank arms 12B detected by the third detector 46 and controls the rotational speed of the electric motor 34 accordingly. In one example, the controller 36 controls the rotational speed of the electric motor 34 such that the rotational speed of the electric motor 34, reduced by a speed reduction unit and output, becomes equal to the rotational speed of the crank 12.

[0109] In the second embodiment, the third detector 46 is omitted, and the magnetic pole detector or the rotary position detector of the electric motor 34 is used, so that the controller 36 controls the electric motor 34 to reduce the torque in the second direction of rotation in accordance with at least one of the rotation amount of the crank 12 in the reverse direction of rotation and the time elapsed since the start of the reverse rotation of the crank 12.

[0110] In the third embodiment, the drive device 30 can be configured to include the output section 38, which rotates integrally with the crank 12. In one example, the one-way clutch 48 is omitted in the human-powered vehicle 10, and the crank 12 and the output section 38 are connected to rotate integrally in both the forward and reverse directions. In this case, the third detector 46 can be omitted, and the controller 36 performs the operation in Fig. The process shown in Figure 12 is carried out according to the detection result of the magnetic pole detector or the rotary position detector provided on the electric motor 34. The rotational amount of the crank 12 is proportional to the rotational amount of the rotor of the electric motor 34. Thus, the controller 36 is configured to rotate the crank 12 by the predetermined angle based on the detection result of the magnetic pole detector or the rotary position detector.

[0111] The second detector 50 can be omitted in the third embodiment and the modified examples.

[0112] In the third embodiment and the modified examples, the control to rotate the crank arms 12B backwards into the predetermined rotational position or the control to rotate the crank arms 12B backwards by the predetermined angle can be performed while the human-powered vehicle 10 is stopped. The drive device 30 further includes a vehicle speed sensor. The vehicle speed sensor detects, for example, the rotational speed of a wheel. The vehicle speed sensor is connected to the controller 36 by wired or wireless communication. In one example, before step S51 in the flowchart of Fig. 11. A determination is added as to whether the human-powered vehicle 10 is stopped or not. In another example, before step S61, the flowchart of Fig. Step 12 adds a determination as to whether the human-powered vehicle 10 is stopped or not. If, based on the vehicle speed sensor's detection result, the controller 36 determines that the human-powered vehicle 10 is stopped, the controller 36 proceeds to steps S51 and S61. If the controller 36 determines that the human-powered vehicle 10 is not stopped, the controller 36 temporarily terminates the operation.

[0113] In the third embodiment and the modified examples, the controller 36 can change the predetermined rotational position and angle based on at least one of the roll angle and yaw angle as the angle of the human-powered vehicle 10. In this case, the human-powered vehicle 10 includes, for example, a fourth detector that detects at least one of the roll angle and yaw angle. In one example, the fourth detector includes at least one accelerometer and one gyroscope. For example, in a case where the human-powered vehicle 10 is rolling, the controller 36 rotates the electric motor 34 in the second direction of rotation so that one of the crank arms 12B, which is located closer to the ground, is not located near the dead center when the human-powered vehicle 10 is rolling.Thus, in a case where the human-powered vehicle 10 is rolling, contact between the pedal 18 coupled to the crank arm 12B, which is closer to the ground, and the ground is avoided when the human-powered vehicle 10 is rolling.

[0114] In the third embodiment and the modified examples, the drive device 30 can be configured to select a control state in which the crank arms 12B are controlled to the predetermined rotational position according to the actuation of an actuating section different from the actuating section 52, and a control state in which the crank arms 12B are controlled and rotated backwards by the predetermined angle.

[0115] In the third embodiment and the modified examples, in a case where the torque detected by the first detector 42 assumes a positive value while the crank arms 12B are rotated backwards by the electric motor 34, the drive device 30 can control the electric motor 34 in order not to generate any torque in the second direction of rotation.

[0116] The phrase “at least one of,” as used in this revelation, means “one or more” of a desired choice. For example, the phrase “at least one of,” as used in this revelation, means “only a single choice” or “both of two choices” when the number of choices is two. On the other hand, the phrase “at least one of,” as used in this revelation, means “only a single choice” or “any combination of two or more choices” when the number of choices is three or more. DESCRIPTION OF REFERENCE MARKS 10 human-powered vehicles, 10H handlebars, 12 cranks 12A Crankshaft, 12B crank arm, 14 drive wheel, 16 frames, 16A front fork, 16B stem, 18 pedal, 20 Drive mechanism, 22 first body of revolution, 24 coupling element, 26 second body of revolution, 28 one-way couplings, 30 Drive device (drive device of a human-powered vehicle), 32 battery, 34 Electric motor, 35 one-way couplings, 36 controllers, 37 Speed ​​reduction unit, 38th issue section, 40 drive circuit, 42 first detector, 44 memory slots, 46 third detector, 48 one-way couplings, 50 second detector, 52 Actuation section

Claims

[1] Propulsion device (30) of a human-powered vehicle (10), comprising: an electric motor (34) configured to rotate in a first direction of rotation and assist the propulsion of a human-powered vehicle (10) when a crank (12) is rotating forward, and to receive a driving force from the crank (12) when the crank is rotating backward and to rotate in a second direction of rotation, the second direction of rotation being opposite to the first direction of rotation; and a controller (36) configured to control the electric motor (34) to generate a torque in the second direction of rotation in at least one of a state in which the crank (12) rotates backwards and in a state in which a human driving force is applied to the crank (12) so that the crank (12) rotates backwards. [2] Drive device (30) of a human-powered vehicle (10) according to claim 1, further comprising an output section (38) which is arranged to rotate integrally with the crank (12). [3] Drive device (30) of a human-powered vehicle (10) according to claim 1 or 2, further comprising a first detector (42) which is configured to detect the torque applied to the crank (12). [4] Drive device (30) of a human-powered vehicle (10) according to claim 2, further comprising a first detector (42) configured to detect a torque applied to the crank (12), wherein the first detector (42) is provided on a transmission path for human power between a crankshaft (12A) of the crank (12) and the output section (38). [5] Drive device (30) of a human-powered vehicle (10) according to claim 3 or 4, wherein in a case where the torque detected by the first detector (42) has a negative value, the controller (36) controls the electric motor (34) so ​​that the value of the torque detected by the first detector (42) approaches zero. [6] Drive device (30) of a human-powered vehicle (10) according to one of claims 1 to 5, wherein the controller (36) controls a rotational speed of the electric motor (34). [7] Drive device (30) of a human-powered vehicle (10) according to any one of claims 1 to 6, wherein the controller (36) controls the torque of the electric motor (34). [8] Drive device (30) of a human-powered vehicle (10) according to claim 1, further comprising an output section (38) which is arranged to rotate independently of the crank (12). [9] Drive device (30) of a human-powered vehicle (10) according to one of claims 1 to 8, wherein the controller (36) controls the electric motor (34) such that in a state in which the crank (12) rotates backwards, the torque of the electric motor (34) in the second direction of rotation is in a predetermined range, preferably the predetermined range is a range in which the crank (12) is not rotated backwards exclusively by the driving force of the electric motor (34). [10] Drive device (30) of a human-powered vehicle (10) according to one of claims 1 to 8, wherein the controller (36) controls the electric motor (34) according to the acceleration of the crank (12) in a reverse direction of rotation, preferably the controller (36) controls the electric motor (34) according to the acceleration of the crank (12) immediately after the start of the reverse rotation of the crank (12). [11] Drive device (30) of a human-powered vehicle (10) according to claim 10, wherein the controller (36) controls the electric motor (34) such that the torque in the second direction of rotation decreases in accordance with at least one of the rotational amount of the crank (12) in the reverse direction of rotation and a time elapsed since the start of the reverse direction of rotation. [12] Drive device (30) of a human-powered vehicle (10) according to one of claims 1 to 11, wherein in a case where the crank (12) stops rotating backwards, the controller (36) controls the electric motor (34) so ​​that no torque is generated in the second direction of rotation. [13] Drive device (30) of a human-powered vehicle (10), comprising: an electric motor (34) configured to rotate in a first direction of rotation and to assist the propulsion of a human-powered vehicle (10) in a case in which a crank (12) rotates forwards, and to rotate the crank (12) backwards by rotating it in a second direction of rotation opposite to the first direction of rotation; and a controller (36) that rotates the electric motor (34) in the second direction of rotation to rotate a crank arm (12B) of the crank (12) backwards into a predetermined rotational position or to rotate the crank arm (12B) backwards by a predetermined angle, wherein the predetermined rotational position and the predetermined angle are modifiable according to at least one angle of the human-powered vehicle (10), (one) information relating to a past stop position of the crank arm (12B), and a setting made by a user. [14] Drive device (30) of a human-powered vehicle (10) according to claim 13, wherein the angle of the human-powered vehicle (10) includes a gradient angle of the human-powered vehicle (10). [15] Drive device (30) of a human-powered vehicle (10) according to claim 13 or 14, wherein in at least one of a case in which the crank (12) rotates backwards and in a case in which an actuating section (52) is actuated, the controller (36) rotates the electric motor (34) in the second direction of rotation. [16] Drive device (30) of a human-powered vehicle (10) according to one of claims 13 to 15, which further comprises a second detector (50) configured to detect the angle of the human-powered vehicle (10). [17] Drive device (30) of a human-powered vehicle (10) according to one of claims 1 to 16, which further comprises a third detector (46) which is configured to detect a rotational position of a crank arm (12B) of the crank (12).

Images