JP2024051219A - Control device for human-powered vehicles - Google Patents

Abstract

[Problem] To provide a control device that allows a rider to easily control a human-powered vehicle. [Solution] A control device for a human-powered vehicle, comprising a control unit configured to control a motor that applies an assist force to the human-powered vehicle in response to a human-powered driving force input to a crank arm of the human-powered vehicle, and when driving the motor in response to the human-powered driving force, the control unit controls the motor so that the assist force is minimized within a range of the rotational phase of the crank arm within ±30 degrees from a first reference rotational phase at which the human-powered driving force is maximized during one rotation of the crank arm. [Selected Figure] Figure 1

Description

This disclosure relates to technology for control devices for human-powered vehicles.

For example, Patent Document 1 discloses a control device that controls a motor for providing an assist force to a human-powered vehicle in accordance with the human-powered driving force. The control device controls the motor so that, during one rotation of the crank arm, the assist force is maximized when the rotation phase of the crank arm is the rotation phase in which the human-powered driving force is greatest, and so that the assist force is minimized when the rotation phase in which the human-powered driving force is the smallest.

Japanese Patent Application Laid-Open No. 7-323880

In conventional motor control, the assist force pulsates in accordance with the pulsation of the human-powered driving force, which tends to increase the pulsation of the propulsion force of the human-powered vehicle, including the human-powered driving force and the assist force. Depending on the driving environment of the human-powered vehicle, this can make it difficult for the rider to control the human-powered vehicle.

One of the objectives of the present disclosure is to provide a control device that makes it easier for a rider to control a human-powered vehicle.

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 configured to control a motor that provides an assist force to the human-powered vehicle in accordance with a human-powered driving force input to a crank arm of the human-powered vehicle, and when driving the motor in accordance with the human-powered driving force, the control unit controls the motor so that the assist force is minimized within a range of the rotational phase of the crank arm within ±30 degrees from a first reference rotational phase at which the human-powered driving force is greatest during one rotation of the crank arm.
According to the control device of the first aspect, the assist force can be reduced in the range in which the human-powered driving force input during one rotation of the crank arm becomes large, thereby suppressing the pulsation of the propulsion force of the human-powered vehicle, which includes the human-powered driving force and the assist force, making it easier for the rider to control the human-powered vehicle.

In the control device of a second aspect according to the first aspect, when the control unit drives the motor in response to a manual driving force, the control unit controls the motor so that the assist force is minimized when the rotational phase of the crank arm is a first reference rotational phase.
According to the control device of the second aspect, when the manual driving force input during one rotation of the crank arm becomes large, the assist force becomes minimum, thereby effectively suppressing pulsation of the propulsion force of the human-powered vehicle, which includes the manual driving force and the assist force.

In the control device of a third aspect according to the first or second aspect, when the control unit drives the motor in response to manual driving force, the control unit controls the motor so that the assist force is maximized within a range of the rotational phase of the crank within ±30 degrees from a second reference rotational phase at which the manual driving force is smallest during one rotation of the crank arm.
According to the control device of the third aspect, the assist force becomes maximum when the manual driving force input during one rotation of the crank arm becomes small, thereby further suppressing pulsation of the propulsion force of the human-powered vehicle, which includes the manual driving force and the assist force.

In the control device of a fourth aspect according to the third aspect, when the control unit drives the motor in response to manual driving force, the control unit controls the motor so that the assist force is maximized when the rotational phase of the crank arm is the second reference rotational phase.
According to the control device of the fourth aspect, the assist force becomes maximum when the manual driving force input during one rotation of the crank arm becomes small, so that the pulsation of the propulsion force of the human-powered vehicle, which includes the manual driving force and the assist force, can be more effectively suppressed.

In the control device of a fifth aspect according to any one of the first to fourth aspects, the control unit controls the motor so that, when driving the motor in accordance with a manual driving force, the assist force is decreased when the manual driving force increases, and the assist force is increased when the manual driving force decreases.
According to the control device of the fifth aspect, pulsation of the propulsive force of the human-powered vehicle, which includes the human-powered driving force and the assist force, can be further suppressed.

In the control device of a sixth aspect according to any one of the first to fifth aspects, the control unit is configured to control the motor in a first control state and a second control state, and in the first control state, when the motor is driven in response to manual driving force, the control unit controls the motor so that the assist force is minimized within a range of the rotational phase of the crank arm within ±30 degrees from a first reference rotational phase at which the manual driving force is greatest during one rotation of the crank arm, and in the second control state, when the motor is driven in response to manual driving force, the control unit controls the motor so that the assist force is maximized within a range of the rotational phase of the crank arm within ±30 degrees from the first reference rotational phase during one rotation of the crank arm.
According to the control device of the sixth aspect, the motor is controlled in the first control state and the second control state, thereby improving convenience.

In the control device of the seventh aspect according to the sixth aspect, when the control unit drives the motor in accordance with the manual driving force in the first control state, the control unit controls the motor so that the assist force is maximized within a range of the rotational phase of the crank within ±30 degrees from the second reference rotational phase at which the manual driving force is smallest during one rotation of the crank arm.
According to the control device of the seventh aspect, in the first control state, when the manual driving force input during one rotation of the crank arm becomes small, the assist force becomes maximum, thereby further suppressing the pulsation of the propulsion force of the human-powered vehicle, which includes the manual driving force and the assist force.

In the control device of the eighth aspect according to the sixth or seventh aspect, the control unit is configured to switch the control state between the second control state and the first control state depending on at least one of the driving environment of the human-powered vehicle, the driving state of the human-powered vehicle, and the operation of an operating device of the human-powered vehicle.
According to the control device of the eighth aspect, the control state of the motor can be switched from one of the first control state and the second control state to the other of the first control state and the second control state depending on at least one of the driving environment of the human-powered vehicle, the driving state of the human-powered vehicle, and the operation of the operating device of the human-powered vehicle, thereby improving convenience.

In the control device of a ninth aspect according to the eighth aspect, the driving environment includes at least one of a gradient of a road of the human-powered vehicle, a friction resistance of a road surface of the road, and a location of the road.
According to the control device of the ninth aspect, the control state of the motor is automatically switched between the second control state and the first control state depending on at least one of the gradient of the road on which the human-powered vehicle is traveling, the frictional resistance of the road surface of the road, and the location of the road, thereby improving convenience.

In the control device according to the eighth or ninth aspect of the tenth aspect, the driving conditions include a rotation speed of a wheel of the human-powered vehicle.
According to the control device of the tenth aspect, the control state of the motor is automatically switched between the second control state and the first control state depending on the rotational speed of the wheels of the human-powered vehicle, thereby improving convenience.

In the control device of an eleventh aspect according to any one of the eighth to tenth aspects, the control unit switches from the second control state to the first control state when a first condition is satisfied in the second control state.
According to the control device of the eleventh aspect, when the first condition is satisfied, the control state of the motor is switched from the second control state to the first control state, thereby improving convenience.

In the control device of a twelfth aspect according to the eleventh aspect, the first condition is satisfied when the gradient is equal to or greater than a predetermined value.
According to the control device of the twelfth aspect, when the gradient is equal to or greater than a predetermined value, the control state of the motor is switched from the second control state to the first control state, making it easier for the rider to stably control the human-powered vehicle on slopes.

In the control device of a thirteenth aspect according to the eleventh or twelfth aspect, the first condition is satisfied when the frictional resistance is equal to or less than a predetermined value.
According to the control device of the thirteenth aspect, when the frictional resistance is equal to or lower than a predetermined value, the control state of the motor is switched from the second control state to the first control state, making it easier for the rider to stably control the human-powered vehicle even when the frictional resistance decreases.

In the control device of a fourteenth aspect according to any one of the eleventh to thirteenth aspects, the first condition is satisfied when the location is a predetermined location.
According to the control device of the fourteenth aspect, the control state of the motor is switched from the second control state to the first control state depending on the location. For example, in a location where slippage is likely to occur, the control state of the motor is switched from the second control state to the first control state, which makes it easier for the rider to stably control the human-powered vehicle.

In the control device of a fifteenth aspect according to the tenth aspect, when a first condition is satisfied in the second control state, the control unit switches the second control state to the first control state.
According to the control device of the fifteenth aspect, when the first condition is satisfied, the control state of the motor is switched from the second control state to the first control state, thereby improving convenience.

In the control device of the sixteenth aspect according to the fifteenth aspect, the wheels include front wheels and rear wheels, and the first condition is satisfied when the difference between the rotational speed of the front wheels and the rotational speed of the rear wheels is greater than or equal to a predetermined value.
According to the control device of the sixteenth aspect, when the difference between the rotational speed of the front wheel and the rotational speed of the rear wheel is equal to or greater than a predetermined value, the control state of the motor is switched from the second control state to the first control state, making it easier for the rider to stably control the human-powered vehicle.

In the control device of a seventeenth aspect according to the eighth aspect, when a first condition is satisfied in the second control state, the control unit switches the second control state to the first control state.
According to the control device of the seventeenth aspect, when the first condition is satisfied, the control state of the motor is switched from the second control state to the first control state, thereby improving convenience.

In the control device of an eighteenth aspect according to the seventeenth aspect, the first condition is satisfied when the operating device is operated.
According to the control device of the eighteenth aspect, the control state of the motor can be switched from the second control state to the first control state by the user operating the operating device, thereby improving convenience.

In the control device of a nineteenth aspect according to any one of the sixth to eighteenth aspects, the control unit is configured to control the motor in the second control state if the second condition is satisfied in the first control state.
According to the control device of the nineteenth aspect, when the second condition is satisfied, the control state of the motor is switched from the second control state to the first control state, thereby improving convenience.

In the control device of the twentieth aspect according to the nineteenth aspect, the second condition is satisfied when a predetermined period of time has elapsed since the first condition was satisfied.
According to the control device of the twentieth aspect, frequent changes in the control state of the motor can be suppressed.

The control device disclosed herein makes it easier for the rider to control the human-powered vehicle.

1 is a side view showing a human-powered vehicle equipped with a control device according to a first embodiment. FIG. 2 is a block diagram showing an example of an electrical configuration of a human-powered vehicle equipped with a control device. FIG. 4 is a diagram showing an example of a manual driving force when a crank arm rotates once. FIG. 13 is a diagram showing an example of a manual driving force, an assisting force, and a resultant force of the manual driving force and the assisting force when the crank arm makes one rotation in the first and fourth embodiments. FIG. 11 is a diagram showing an example of a manual driving force, an assisting force, and a resultant force of the manual driving force and the assisting force when the crank arm makes one rotation in the second embodiment. FIG. 13 is a block diagram showing an example of an electrical configuration of a human-powered vehicle equipped with a control device according to a fourth embodiment. FIG. 13 is a diagram showing an example of a manual driving force, an assisting force, and a resultant force of the manual driving force and the assisting force when the crank arm makes one rotation in the fourth embodiment. 13 is a flowchart showing a control flow in the fourth embodiment. 13 is a flowchart showing a control flow in the fifth embodiment. 13 is a flowchart showing a control flow in the sixth embodiment. 23 is a flowchart showing a control flow in the seventh embodiment. 23 is a flowchart showing a control flow in the eighth embodiment.

First Embodiment
A human-powered vehicle 10 including a control device 21 for a human-powered vehicle according to a first embodiment will be described. Figures 1 to 4 will be used to describe the human-powered vehicle 10 according to the first embodiment.

The human-powered vehicle 10 has at least one wheel 16 and is a vehicle that can be driven by at least a human-powered driving force F1. 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 16 that the human-powered vehicle 10 has is not limited. The human-powered vehicle 10 includes, for example, a one-wheeled vehicle and a vehicle that has two or more wheels 16. The human-powered vehicle 10 is not limited to vehicles that can be driven only by a human-powered driving force F1. The human-powered vehicle 10 includes an E-bike that uses not only the human-powered driving force F1 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 is described as a bicycle.

The human-powered vehicle 10 includes a crank 11, a frame 12, a seat 13, handlebars 14, a front fork 15, wheels 16, a drive mechanism 17, a transmission 18, a battery 19, a drive unit 20, and a control device 21. The crank 11 shown in FIG. 1 includes a crank shaft 11a that is rotatable relative to the frame 12, and a pair of crank arms 11b provided at both ends of the crank shaft 11a in the axial direction. A first pedal 11c is connected to one of the pair of crank arms 11b, and a second pedal 11d is connected to the other of the pair of crank arms 11b. The pair of crank arms 11b have rotational phases that differ from each other by 180 degrees.

A seat 13 is attached to the frame 12 via a seat post 13a. The frame 12 rotatably supports a handlebar 14 and a front fork 15. The handlebar 14 is configured so that it can be grasped by a user. When the handlebar 14 rotates relative to the frame 12, the front fork 15 rotates, and the traveling direction of the human-powered vehicle 10 changes.

The wheels 16 include a front wheel 16a and a rear wheel 16b. The front wheel 16a is rotatably attached to the front fork 15. The rear wheel 16b is rotatably attached to the frame 12. The drive mechanism 17 connects the crank 11 and the rear wheel 16b. The drive mechanism 17 includes a first rotating body 17a, a second rotating body 17b, and a first drive force transmission unit 17c.

In this embodiment, the first rotating body 17a includes one front sprocket. The first rotating body 17a may include multiple front sprockets. The first rotating body 17a is connected to the crankshaft 11a via the second driving force transmission part 20b of the drive unit 20. The second driving force transmission part 20b is configured to rotate integrally with the crankshaft 11a. The first rotating body 17a rotates in conjunction with the rotation of the second driving force transmission part 20b. When the crankshaft 11a rotates in the first rotational direction and the human-powered driving force F1 is transmitted to the rear wheel 16b, the human-powered vehicle 10 moves forward. The second driving force transmission unit 20b may include a one-way clutch that allows the crankshaft 11a and the first rotor 17a to rotate together when the crankshaft 11a rotates in a first rotational direction, and allows the crankshaft 11a and the first rotor 17a to rotate relative to each other when the crankshaft 11a rotates in a second rotational direction opposite to the first rotational direction.

In this embodiment, the second rotating body 17b includes multiple rear sprockets. The second rotating body 17b may include one front sprocket. The second rotating body 17b is connected to the rear wheel 16b. The first driving force transmission unit 17c transmits the rotational force of the first rotating body 17a to the second rotating body 17b. The first driving force transmission unit 17c includes, for example, a chain. The first rotating body 17a and the second rotating body 17b may include pulleys, and the first driving force transmission unit 17c may include a belt. The first rotating body 17a and the second rotating body 17b may include bevel gears, and the first driving force transmission unit 17c may include a shaft.

The transmission 18 changes the gear ratio of the human-powered vehicle 10. The gear ratio indicates the ratio of the rotation speed of the rear wheel 16b to the rotation speed of the crankshaft 11a. The transmission 18 includes at least one of an external transmission and an internal transmission. In this embodiment, the transmission 18 includes an external transmission. When the transmission 18 includes an external transmission, the gear ratio is calculated, for example, by dividing the number of teeth of the front sprocket with which the first driving force transmission unit 17c engages by the number of teeth of the rear sprocket with which the first driving force transmission unit 17c engages. The external transmission includes at least one of a front derailleur and a rear derailleur 18a. In this embodiment, the external transmission includes the rear derailleur 18a. The rear derailleur 18a is configured to switch the first driving force transmission unit 17c between multiple rear sprockets when the gear shift operation device is operated by the user.

The battery 19 supplies power to the electronic devices. The electronic devices include components mounted on the human-powered vehicle 10. The electronic devices include a control device 21, a drive unit 20, a driving force sensor 22, and a rotation phase sensor 23. The battery 19 includes, for example, at least one of a non-rechargeable battery and a rechargeable battery. The rechargeable battery is configured to be rechargeable by power from an external power source. The battery 19 is provided in the frame 12. For example, at least a portion of the battery 19 is disposed within the down tube of the frame 12.

The drive unit 20 shown in Fig. 1 and Fig. 2 is configured to apply an assist force F2 to the human-powered vehicle 10 in response to a human-powered driving force F1 input to a pair of crank arms 11b. The drive unit 20 includes a motor 20a and a second driving force transmission unit 20b.

The motor 20a is configured to be driven by electric power from the battery 19. The motor 20a is configured to transmit driving force to the power transmission path of the manual driving force F1 from each pedal 11c, 11d to the rear wheel 16b, or to the front wheel 16a. In this embodiment, the motor 20a is configured to transmit driving force to the power transmission path of the manual driving force F1 by being connected to the second driving force transmission unit 20b shown in FIG. 1. The motor 20a may be connected to the second driving force transmission unit 20b via a reducer.

The second driving force transmission section 20b receives the manual driving force F1 and the assist force F2 of the motor 20a. The manual driving force F1 and the assist force F2 are transmitted to the rear wheel 16b via the drive mechanism 17, causing the manual-powered vehicle 10 to move. In this specification, the resultant force of the manual driving force F1 and the assist force F2 is referred to as the total driving force F3.

The control device 21 is a control device 21 for a human-powered vehicle, and includes a control unit 21b configured to control the motor 20a, which applies an assist force F2 to the human-powered vehicle 10, in response to the human-powered driving force F1 input to the crank arm 11b of the human-powered vehicle 10. FIG. 2 shows an example of the control device 21. The control device 21 shown in FIG. 2 includes a memory unit 21a and a control unit 21b.

The storage unit 21a stores the control program and information used in the control process. The storage unit 21a includes, for example, at least one of a non-volatile memory, a volatile memory, and a hard disk.

The control unit 21b is configured to execute control related to the drive unit 20. The control unit 21b includes an arithmetic processing unit that executes a predetermined control program. The arithmetic processing unit includes, for example, a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). The control unit 21b may include one or more microcomputers. The control unit 21b further includes an inverter circuit connected to the motor 20a. The control unit 21b is configured to communicate with the driving force sensor 22 and the rotation phase sensor 23 via an electric cable or a wireless communication device. The control unit 21b may be included in the drive unit 20.

The driving force sensor 22 is configured to detect information related to the manual driving force F1 input to the pair of crank arms 11b. The driving force sensor 22 is provided, for example, in a transmission path of the driving force from each pedal 11c, 11d to the first rotating body 17a. The driving force sensor 22 includes, for example, a strain sensor. The driving force sensor 22 may include a magnetostrictive sensor, an optical sensor, and a pressure sensor. The driving force sensor 22 outputs a signal corresponding to the manual driving force F1 applied to the pair of crank arms 11b to the control unit 21b. The control unit 21b is configured to detect the manual driving force F1 based on the signal output from the driving force sensor 22. The driving force sensor 22 may be provided in the drive unit 20.

The rotation phase sensor 23 is configured to detect information related to the rotation phase of the crank arm 11b. The rotation phase sensor 23 is provided, for example, on the frame 12. The rotation phase sensor 23 is configured, for example, to include a magnetic sensor that outputs a signal corresponding to the strength of a magnetic field. The magnetic sensor includes an annular magnet whose magnetic field strength changes in the circumferential direction. The rotation phase sensor 23 outputs a signal corresponding to the rotation phase of the crank arm 11b to the control unit 21b. The control unit 21b is configured to detect the rotation phase of the crank arm 11b based on the signal output from the rotation phase sensor 23. The rotation phase sensor 23 may be provided in the drive unit 20.

The manual driving force F1 changes according to the rotation phase of the crank arm 11b. FIG. 3 shows an example of the relationship between the manual driving force F1 and the rotation phase of the crank arm 11b. The rotation phase of the crank arm 11b represents the rotation phase when the crank arm 11b is rotated in the first rotation direction. In the graph of FIG. 3, the vertical axis represents torque and the horizontal axis represents the rotation phase. 0 degrees, 180 degrees, and 360 degrees shown in FIG. 3 indicate that the pair of crank arms 11b are at top dead center and bottom dead center. In FIG. 3, the manual driving force F1 is minimum when the rotation phase of the crank arm 11b is at top dead center and bottom dead center. In FIG. 3, the manual driving force F1 is maximum when the rotation phase of the crank arm 11b advances 90 degrees from the top dead center and bottom dead center.

In this embodiment, the control unit 21b controls the motor 20a so that the rotation phase of the crank arm 11b at which the assist force F2 is at its maximum is different from the rotation phase of the crank arm 11b at which the manual driving force F1 is at its maximum. Figure 4 shows an example of the control of the motor 20a by the control unit 21b. In Figure 4, F1 is shown by a solid line, F2 is shown by a dashed line, and F3 is shown by a virtual line.

The assist force F2 shown in FIG. 4 is an example of the assist force F2 applied to the human-powered vehicle 10 by controlling the motor 20a according to the human-powered driving force F1 shown in FIG. 3. The total driving force F3 shown in FIG. 4 is the resultant force of the human-powered driving force F1 and the assist force F2 applied to the human-powered vehicle 10 by controlling the motor 20a according to the human-powered driving force F1 shown in FIG. 3.

As shown in FIG. 4, when the control unit 21b drives the motor 20a in response to the manual driving force F1, the control unit 21b controls the motor 20a so that the assist force F2 is minimized when the rotation phase of the crank arm 11b is within a range of ±30 degrees from the first reference rotation phase at which the manual driving force F1 is maximized during one rotation of the crank arm 11b. In this embodiment, when the control unit 21b drives the motor 20a in response to the manual driving force F1, the control unit 21b controls the motor 20a so that the assist force F2 is minimized when the rotation phase of the crank arm 11b is the first reference rotation phase. The first reference rotation phase includes 90 degrees and 270 degrees as shown in FIG. 4.

When the control unit 21b drives the motor 20a according to the manual driving force F1, the control unit 21b controls the motor 20a so that the assist force F2 is maximized when the rotation phase of the crank 11 is within a range of ±30 degrees from the second reference rotation phase where the manual driving force F1 is smallest during one rotation of the crank arm 11b. In this embodiment, when the control unit 21b drives the motor 20a according to the manual driving force F1, the control unit 21b controls the motor 20a so that the assist force F2 is maximized when the rotation phase of the crank arm 11b is the second reference rotation phase. The second reference rotation phase includes 0 degrees, 180 degrees, and 360 degrees as shown in FIG. 4.

The control unit 21b can calculate the assist force F2 shown in FIG. 4 based on, for example, a signal from the driving force sensor 22 shown in FIG. 2. For example, the control unit 21b can calculate the assist force F2 by substituting the manual driving force F1 detected based on the signal from the driving force sensor 22 into a formula in which the assist force F2 decreases as the manual driving force F1 increases.

The method of calculating the assist force F2 by the control unit 21b is not particularly limited. The control unit 21b may calculate the assist force F2 based on, for example, a signal from the driving force sensor 22 and a signal from the rotation phase sensor 23. For example, the control unit 21b detects the manual driving force F1 based on the signal from the driving force sensor 22, and detects the rotation phase of the crank arm 11b based on the signal from the rotation phase sensor 23. The control unit 21b can calculate the basic assist force based on the detected manual driving force F1 and a predetermined assist ratio, and correct the basic assist force based on the detected rotation phase of the crank arm 11b to calculate the assist force F2.

Unlike this embodiment, when the assist force F2 is at its maximum in the first reference rotation phase where the manual driving force F1 shown in FIG. 4 is at its maximum, the total driving force F3 is at its maximum in the first reference rotation phase during one rotation of the crank arm 11b. The maximum value of the total driving force F3 is the resultant force of the maximum value of the manual driving force F1 and the maximum value of the assist force F2.

In this embodiment, the control unit 21b controls the motor 20a, so that the assist force F2 is minimized in the first reference rotation phase, and the maximum value of the total driving force F3 during one rotation of the crank arm 11b is unlikely to become large. Since the maximum value of the total driving force F3 is unlikely to become large, the difference between the maximum value and the minimum value of the total driving force F3 during one rotation of the crank arm 11b is small. Since the difference between the maximum value and the minimum value of the total driving force F3 is small, the control unit 21b can suppress the pulsation of the total driving force F3 associated with the pulsation of the human-powered driving force F1, making it easier for the rider to control the human-powered vehicle 10. In particular, when the human-powered driving force F1 and the assist force F2 are transmitted to the same wheel 16 as in this embodiment, the control unit 21b can suppress the pulsation of the total driving force F3 to suppress slippage of the driving wheel. The driving wheel refers to the wheel 16 to which the power from the crank 11 is transmitted by the drive mechanism 17. In this embodiment, the driving wheel includes the rear wheel 16b.

For example, when the human-powered vehicle 10 is traveling off-road on a steep slope, the control unit 21b suppresses slippage of the drive wheels, which prevents the human-powered vehicle 10 from stopping and slowing down, and makes it difficult for the user to put their feet on the ground. By suppressing slippage of the drive wheels by the control unit 21b, the human-powered vehicle 10 can travel efficiently on the road surface.

The control unit 21b may control the motor 20a so that the assist force F2 becomes zero (0) in the first reference rotation phase. By making the assist force F2 zero (0) in the first reference rotation phase, the control unit 21b can further suppress the maximum value of the total driving force F3 during one rotation of the crank arm 11b, thereby effectively suppressing the pulsation of the total driving force F3 associated with the pulsation of the manual driving force F1.

Unlike this embodiment, when the assist force F2 is at its minimum in the second reference rotation phase where the manual driving force F1 is at its minimum, the total driving force F3 is at its minimum in the second reference rotation phase during one rotation of the crank arm 11b. The minimum value of the total driving force F3 is the resultant force of the minimum value of the manual driving force F1 and the minimum value of the assist force F2.

In this embodiment, since the assist force F2 is maximum at the second reference rotation phase, the minimum value of the total driving force F3 during one rotation of the crank arm 11b is unlikely to become small. Because the minimum value of the total driving force F3 is unlikely to become small and the maximum value of the total driving force F3 is unlikely to become large, the control unit 21b can effectively suppress the pulsation of the total driving force F3 that accompanies the pulsation of the manual driving force F1. The control unit 21b can effectively suppress the pulsation of the total driving force F3.

Second Embodiment
The control device 21 of the second embodiment will be described. Fig. 3 and Fig. 5 are used to describe the control device 21 of the second embodiment. The same reference numerals as those in the first embodiment are used for the configurations common to the first embodiment, and the duplicated description will be omitted.

In this embodiment, the control unit 21b controls the motor 20a so that the assist force F2 is minimized when the rotation phase of the crank arm 11b is in a rotation phase different from the first reference rotation phase in which the manual driving force F1 is at its maximum. The control unit 21b controls the motor 20a so that the assist force F2 is maximized when the rotation phase of the crank arm 11b is in a rotation phase different from the second reference rotation phase in which the manual driving force F1 is at its minimum.

Figure 5 shows an example of the control of the motor 20a by the control unit 21b. In Figure 5, F1 is shown by a solid line, F2 is shown by a dashed line, and F3 is shown by a virtual line. The assist force F2 shown in Figure 5 shows an example of the assist force F2 applied to the human-powered vehicle 10 by the control of the motor 20a according to the human-powered driving force F1 shown in Figure 3. The total driving force F3 shown in Figure 5 shows the resultant force of the human-powered driving force F1 and the assist force F2 applied to the human-powered vehicle 10 by the control of the motor 20a according to the human-powered driving force F1 shown in Figure 3. The first reference rotation phase includes 90 degrees and 270 degrees shown in Figure 5. The second reference rotation phase includes 0 degrees, 180 degrees, and 360 degrees shown in Figure 5.

As shown in FIG. 5, the control unit 21b controls the motor 20a so that the assist force F2 is minimized when the rotational phase of the crank arm 11b is shifted by -30 degrees from the first reference rotational phase. By controlling the motor 20a, the control unit 21b can minimize the assist force F2 at a rotational phase relatively close to the first reference rotational phase where the manual driving force F1 is at its maximum, so that the maximum value of the total driving force F3 during one rotation of the crank arm 11b is unlikely to become large. Since the maximum value of the total driving force F3 is unlikely to become large, it becomes easier for the rider to control the human-powered vehicle 10. When the manual driving force F1 and the assist force F2 are transmitted to the same wheel 16, the control unit 21b can suppress slippage of the driving wheel.

The control unit 21b controls the motor 20a so that the assist force F2 is maximized when the rotational phase of the crank arm 11b is shifted by -30 degrees from the second reference rotational phase. By controlling the motor 20a, the control unit 21b can maximize the assist force F2 at a rotational phase that is relatively close to the second reference rotational phase where the human-powered driving force F1 is at its minimum, so that the minimum value of the total driving force F3 during one rotation of the crank arm 11b is unlikely to become small. Since the minimum value of the total driving force F3 is unlikely to become small and the maximum value of the total driving force F3 is unlikely to become large, it becomes easier for the rider to control the human-powered vehicle 10.

Third Embodiment
The control device 21 of the third embodiment will be described. Fig. 3 and Fig. 4 are used for describing the control device 21 of the third embodiment. The same reference numerals as those in the first and second embodiments are used for the configurations common to the first and second embodiments, and duplicated descriptions will be omitted.

In this embodiment, the control unit 21b is configured to detect a decrease and an increase in the manual driving force F1. The control unit 21b detects a decrease and an increase in the manual driving force F1, for example, based on a signal from the driving force sensor 22. For example, the control unit 21b repeatedly detects the manual driving force F1 at a predetermined cycle. The control unit 21b detects a decrease and an increase in the manual driving force F1 based on the magnitude relationship between the previously detected manual driving force F1 and the currently detected manual driving force F1.

For example, the control unit 21b detects a decrease in the manual driving force F1 when the currently detected manual driving force F1 is smaller than the previously detected manual driving force F1. The control unit 21b may detect a decrease in the manual driving force F1 when the currently detected manual driving force F1 is smaller than the previously detected manual driving force F1 multiple times in succession.

For example, the control unit 21b detects an increase in the manual driving force F1 when the currently detected manual driving force F1 is greater than the previously detected manual driving force F1. The control unit 21b may detect an increase in the manual driving force F1 when the currently detected manual driving force F1 is greater than the previously detected manual driving force F1 multiple times in succession.

The control unit 21b is configured to control the motor 20a according to the results of detecting the decrease and increase of the human-powered driving force F1. FIG. 4 shows an example of the control of the motor 20a by the control unit 21b. The assist force F2 shown in FIG. 4 shows an example of the assist force F2 applied to the human-powered vehicle 10 by controlling the motor 20a according to the human-powered driving force F1 shown in FIG. 3. The total driving force F3 shown in FIG. 4 shows the resultant force of the human-powered driving force F1 and the assist force F2 applied to the human-powered vehicle 10 by controlling the motor 20a according to the human-powered driving force F1 shown in FIG. 3. The first reference rotation phase includes 90 degrees and 270 degrees shown in FIG. 4. The second reference rotation phase includes 0 degrees, 180 degrees, and 360 degrees shown in FIG. 4.

In this embodiment, when the control unit 21b drives the motor 20a according to the manual driving force F1, the control unit 21b controls the motor 20a to decrease the assist force F2 when the manual driving force F1 increases, and to increase the assist force F2 when the manual driving force F1 decreases. In FIG. 4, the control unit 21b detects an increase in the manual driving force F1 when the rotation phase of the crank arm 11b is in the range of 0 degrees to 90 degrees. The control unit 21b controls the motor 20a to decrease the assist force F2 in the range of 0 degrees to 90 degrees.

In FIG. 4, the control unit 21b detects a decrease in the manual driving force F1 when the rotation phase of the crank arm 11b is in the range of 90 degrees to 180 degrees. The control unit 21b controls the motor 20a so that the assist force F2 increases in the range of 90 degrees to 180 degrees.

In FIG. 4, the control unit 21b detects an increase in the manual driving force F1 when the rotation phase of the crank arm 11b is in the range of 180 degrees to 270 degrees. The control unit 21b controls the motor 20a so that the assist force F2 decreases in the range of 180 degrees to 270 degrees.

In FIG. 4, the control unit 21b detects an increase in the manual driving force F1 when the rotation phase of the crank arm 11b is in the range of 270 degrees to 360 degrees. The control unit 21b controls the motor 20a so that the assist force F2 decreases in the range of 270 degrees to 360 degrees.

By controlling the motor 20a shown in FIG. 4, the control unit 21b can suppress pulsation of the total driving force F3 associated with pulsation of the human-powered driving force F1 because the total driving force F3 is unlikely to increase when the human-powered driving force F1 increases, and the total driving force F3 is unlikely to decrease when the human-powered driving force F1 decreases. Being able to suppress pulsation of the total driving force F3 makes it easier for the rider to control the human-powered vehicle 10. When the human-powered driving force F1 and the assist force F2 are transmitted to the same wheel 16, the control unit 21b can effectively suppress the occurrence of slippage of the drive wheel.

Fourth Embodiment
A control device 21 according to a fourth embodiment will be described. The control device 21 according to the fourth embodiment will be described with reference to Figs. 3 to 8. The same reference numerals as those in the first to third embodiments are used for configurations common to the first to third embodiments, and duplicated descriptions will be omitted.

As shown in FIG. 6, in this embodiment, the control unit 21b is configured to communicate with the driving force sensor 22, the rotation phase sensor 23, the driving environment detection unit 24, the driving state detection unit 25, and the operation device 26 via an electric cable or a wireless communication device. The driving environment detection unit 24 is configured to detect information related to the driving environment of the human-powered vehicle 10. The driving environment includes at least one of the gradient of the driving path of the human-powered vehicle 10, the friction resistance of the road surface of the driving path, and the location of the driving path. In this embodiment, the driving environment includes each of the gradient of the driving path of the human-powered vehicle 10, the friction resistance of the road surface of the driving path, and the location of the driving path.

The driving environment detection unit 24 includes electronic devices that detect information related to the gradient of the road. The driving environment detection unit 24 includes, for example, at least one of an attitude sensor that detects the pitch angle of the human-powered vehicle 10 and an acceleration sensor that detects the acceleration of the human-powered vehicle 10 in the traveling direction. The attitude sensor outputs a signal corresponding to the pitch angle of the human-powered vehicle 10 to the control unit 21b. The acceleration sensor outputs a signal corresponding to the acceleration of the human-powered vehicle 10 in the traveling direction to the control unit 21b. The control unit 21b is configured to detect the gradient of the road based on at least one of the signal corresponding to the pitch angle of the human-powered vehicle 10 and the signal corresponding to the acceleration of the human-powered vehicle 10 in the traveling direction. The attitude sensor includes at least one of a gyro sensor and an acceleration sensor that detects at least the acceleration in the direction of gravity.

The driving environment detection unit 24 includes a device that detects information related to the friction resistance of the road surface of the driving path. The driving environment detection unit 24 includes, for example, a camera. The camera is configured to capture an image of the road on which the human-powered vehicle 10 is traveling. The camera outputs a signal corresponding to the image capture result to the control unit 21b. The control unit 21b detects the friction resistance of the road surface of the driving path based on the signal corresponding to the image capture result. The driving environment detection unit 24 may detect information related to the friction resistance of the road surface using a device other than the camera. The driving environment detection unit 24 may detect information related to the friction resistance of the road surface using, for example, at least one of a hygrometer that detects the dryness of the road surface and a vibration sensor that detects unevenness of the road surface.

The driving environment detection unit 24 includes equipment that detects information about the location of the driving road. The driving environment detection unit 24 includes, for example, a GPS (global positioning system) receiver and a memory unit 21a that stores map data of the location where the human-powered vehicle 10 is traveling. The GPS receiver outputs a signal corresponding to the position information detected by GPS communication to the control unit 21b. The control unit 21b is configured to detect the location where the human-powered vehicle 10 is traveling based on the signal corresponding to the position information and the map data stored in the memory unit 21a.

The running condition detection unit 25 is configured to detect information related to the running condition of the human-powered vehicle 10. The running condition includes the rotation speed of the wheels 16 of the human-powered vehicle 10. The running condition detection unit 25 includes, for example, a front wheel rotation sensor configured to detect the rotation speed of the front wheels 16a, and a rear wheel rotation sensor configured to detect the rotation speed of the rear wheels 16b.

The front wheel rotation sensor is, for example, a magnetic sensor that detects the magnetism of a magnet provided on the front wheel 16a. The front wheel rotation sensor outputs a signal corresponding to the detection result of the rotation speed of the front wheel 16a to the control unit 21b. The rear wheel rotation sensor is, for example, a magnetic sensor that detects the magnetism of a magnet provided on the rear wheel 16b. The rear wheel rotation sensor outputs a signal corresponding to the rotation speed of the rear wheel 16b to the control unit 21b. The control unit 21b is configured to detect the rotation speed of the front wheel 16a and the rotation speed of the rear wheel 16b based on the signal corresponding to the rotation speed of the front wheel 16a and the signal corresponding to the rotation speed of the rear wheel 16b. The front wheel rotation sensor and the rear wheel rotation sensor may be, for example, a magnetic sensor or an optical sensor that detects a rotating member in which a plurality of holes are formed and arranged at a distance from each other in the circumferential direction of the wheel 16.

The operating device 26 is configured to be operated by the user with the hand or finger. The operating device 26 is provided, for example, on the handlebar 14. The operating device 26 includes at least one of a lever and a button. The lever includes at least one of a lever that swings relative to a predetermined member and a lever that rotates around a predetermined rotation axis. The button includes at least one of a push button and a touch panel. The operating device 26 is configured to output a signal corresponding to the operation to the control unit 21b. The control unit 21b is configured to detect the operation of the operating device 26 based on the signal corresponding to the operation.

The control unit 21b is configured to control the motor 20a in the first control state and the second control state. In the first control state, the control unit 21b controls the motor 20a so that the assist force F2 is minimized at a rotation phase that is relatively close to the first reference rotation phase at which the manual driving force F1 is maximized.

When the control unit 21b drives the motor 20a in response to the manual driving force F1 in the first control state, the control unit 21b controls the motor 20a so that the assist force F2 is minimized within a range of the rotation phase of the crank arm 11b of ±30 degrees from a first reference rotation phase where the manual driving force F1 is maximized during one rotation of the crank arm 11b. When the control unit 21b drives the motor 20a in response to the manual driving force F1 in the first control state, the control unit 21b controls the motor 20a so that the assist force F2 is maximized within a range of the rotation phase of the crank 11 of ±30 degrees from a second reference rotation phase where the manual driving force F1 is minimized during one rotation of the crank arm 11b.

In the first control state, the control unit 21b controls the motor 20a, for example, in the same manner as in the first and second embodiments. An example of the control of the motor 20a in the first and second embodiments is shown in FIG. 4 and FIG. 5.

The second control state is different from the first control state. In the second control state, the control unit 21b controls the motor 20a so that the assist force F2 is maximized at a rotation phase that is relatively close to the first reference rotation phase at which the manual driving force F1 is maximized. In this embodiment, in the second control state, when the control unit 21b drives the motor 20a according to the manual driving force F1, the control unit 21b controls the motor 20a so that the assist force F2 is maximized within a range of the rotation phase of the crank arm 11b within ±30 degrees from the first reference rotation phase during one rotation of the crank arm 11b.

Figure 7 shows an example of the control of the motor 20a in the second control state. In Figure 7, F1 is shown by a solid line, F2 is shown by a dashed line, and F3 is shown by a virtual line. The assist force F2 shown in Figure 7 shows an example of the assist force F2 applied to the human-powered vehicle 10 by the control of the motor 20a according to the human-powered driving force F1 shown in Figure 3. The total driving force F3 shown in Figure 7 shows the resultant force of the human-powered driving force F1 and the assist force F2 applied to the human-powered vehicle 10 by the control of the motor 20a according to the human-powered driving force F1 shown in Figure 3. The first reference rotation phase includes 90 degrees and 270 degrees as shown in Figure 7. The second reference rotation phase includes 0 degrees, 180 degrees, and 360 degrees as shown in Figure 7.

As shown in FIG. 7, in the second control state, when the rotation phase of the crank arm 11b is the first reference rotation phase in which the manual driving force F1 is maximum, the control unit 21b controls the motor 20a so that the assist force F2 is maximum. In the second control state, when the rotation phase of the crank arm 11b is the second reference rotation phase in which the manual driving force F1 is minimum, the control unit 21b controls the motor 20a so that the assist force F2 is minimum.

The control unit 21b is configured to change the control state in response to a predetermined parameter. In this embodiment, the control unit 21b is configured to switch the control state between the second control state and the first control state in response to at least one of the driving environment of the human-powered vehicle 10, the driving state of the human-powered vehicle 10, and the operation of the operating device 26 of the human-powered vehicle 10.

An example of a process for changing the control state will be described. FIG. 8 is used to explain the example of the process for changing the control state. The control unit 21b starts a first control flow according to the flowchart shown in FIG. 8 when a predetermined condition is satisfied. The first control flow shows an example of a process for switching the control state of the motor 20a from the second control state to the first control state.

The control unit 21b starts the first control flow, for example, when the control state of the motor 20a is switched from the first control state to the second control state. When the first control flow ends, the control unit 21b repeatedly executes the first control flow at predetermined time intervals until a predetermined condition is satisfied. In this embodiment, the control unit 21b repeatedly executes the first control flow until the control state of the motor 20a is switched from the second control state to the first control state.

When the control unit 21b starts the first control flow, it transitions to step S1, and if the first condition is satisfied in the second control state, it transitions to step S2. If the first condition is not satisfied in the second control state, the control unit 21b ends the first control flow. The first condition is defined, for example, based on at least one of the driving environment of the human-powered vehicle 10, the driving state of the human-powered vehicle 10, and the operation of the operating device 26.

When the first condition is defined based on the driving environment of the human-powered vehicle 10, the first condition is satisfied, for example, when the driving environment of the human-powered vehicle 10 is one in which the drive wheels are likely to slip. For example, the first condition is satisfied when the human-powered vehicle 10 travels on a gradient equal to or greater than a predetermined gradient, when the human-powered vehicle 10 travels on a road surface with a predetermined frictional resistance or less, or when the human-powered vehicle 10 travels in a predetermined location where slippage is likely to occur. When the first condition is defined based on the driving environment of the human-powered vehicle 10, the control unit 21b detects that the first condition is satisfied based on a signal from the driving environment detection unit 24.

When the first condition is defined based on the running state of the human-powered vehicle 10, the first condition is satisfied, for example, when the drive wheels are slipping. For example, the first condition is satisfied when the difference between the rotation speed of the front wheels 16a and the rotation speed of the rear wheels 16b is equal to or greater than a predetermined threshold. When the first condition is defined based on the running state of the human-powered vehicle 10, the control unit 21b detects that the first condition is satisfied based on a signal from the running state detection unit 25.

When the first condition is defined based on the operation of the operating device 26, the first condition is satisfied regardless of slippage of the drive wheels. For example, even if the human-powered vehicle 10 is traveling on a steep slope, the first condition is satisfied when a predetermined operation is performed on the operating device 26. When the first condition is defined based on the operation of the operating device 26, the control unit 21b detects that the first condition is satisfied based on a signal from the operating device 26.

When the first condition is satisfied in the second control state, the control unit 21b proceeds to step S2 and controls the motor 20a in the first control state. After performing the process of step S2, the control unit 21b ends the first control flow.

By executing the first control flow, the control unit 21b can switch the control state of the motor 20a from the second control state to the first control state when the drive wheels are prone to slip and when the drive wheels are slipping. For example, when the human-powered vehicle 10 is traveling on a steep off-road slope, the control unit 21b can automatically switch the control state of the motor 20a from the second control state to the first control state. By controlling the motor 20a in the first control state, the control unit 21b can prevent the drive wheels from slipping and causing the human-powered vehicle 10 to decelerate.

When controlling the motor 20a in the first control state, the control unit 21b is configured to switch the control state of the motor 20a from the first control state to the second control state if a predetermined condition is satisfied. The control unit 21b switches from the first control state to the second control state, for example, if the first condition is not satisfied in the first control state. For example, the control unit 21b switches the control state of the motor 20a from the first control state to the second control state when the human-powered vehicle 10 travels on flat ground and downhill in the first control state. Convenience can be improved by changing the control state by the control unit 21b.

Fifth Embodiment
A control device 21 according to a fifth embodiment will be described. Fig. 9 is used to describe the control device 21 according to the fifth embodiment. The same reference numerals as those in the first to fourth embodiments are used for configurations common to the first to fourth embodiments, and duplicated descriptions will be omitted.

When the first condition is satisfied in the second control state, the control unit 21b switches the second control state to the first control state. In this embodiment, the first condition includes a condition related to the driving environment of the human-powered vehicle 10. An example of a process for changing the control state is described. FIG. 9 is used to explain the example of the process for changing the control state. The control unit 21b starts the second control flow according to the flowchart shown in FIG. 9 when a predetermined condition is satisfied. When the second control flow ends, the control unit 21b repeatedly executes the second control flow at predetermined time intervals until the predetermined condition is satisfied. The conditions for starting the second control flow and the conditions for repeatedly executing the second control flow are the same as those in the fourth embodiment.

When the control unit 21b starts the first control flow, it transitions to step S11, and if the conditions related to the driving environment of the human-powered vehicle 10 are satisfied in the second control state, it transitions to step S12. If the conditions related to the driving environment of the human-powered vehicle 10 are not satisfied in the second control state, the control unit 21b ends the first control flow. The driving environment includes at least one of the gradient of the road on which the human-powered vehicle 10 is traveling, the frictional resistance of the road surface of the road, and the location of the road.

When the driving environment includes a gradient of the road on which the human-powered vehicle 10 is traveling, the first condition is satisfied when the gradient is equal to or greater than a predetermined value. For example, the control unit 21b detects the gradient of the road based on a signal from the attitude sensor and a signal from the acceleration sensor, and proceeds to step S12 when the detected gradient is equal to or greater than a predetermined value. In this embodiment, the predetermined value is set to 25%. The predetermined value may be set to a value other than 25%. The control unit 21b ends the second control flow when the calculated gradient is less than the predetermined value.

When the driving environment includes friction resistance of the road surface of the road, the first condition is satisfied when the friction resistance is equal to or less than a predetermined value. For example, the control unit 21b detects the friction resistance of the road surface based on a signal from the camera, and proceeds to step S12 when the detected result of the friction resistance is equal to or less than a predetermined value. The control unit 21b ends the second control flow when the detected result of the friction resistance is greater than the predetermined value.

When the driving environment includes the location of the driving road, the first condition is satisfied when the location is a predetermined location. For example, the control unit 21b detects the location where the human-powered vehicle 10 is driving based on a signal from the GPS receiver and map data stored in the memory unit 21a. When the location detection result is a predetermined location, the control unit 21b proceeds to step S12. When the location detection result is different from the predetermined location, the control unit 21b ends the second control flow.

When the control unit 21b proceeds to step S12, it controls the motor 20a in the first control state. After performing the process of step S12, the control unit 21b ends the second control flow.

By the control unit 21b executing the second control flow, the control state of the motor 20a is automatically switched from the second control state to the first control state, for example, when the drive wheels are prone to slip and when the drive wheels slip. For example, when the human-powered vehicle 10 travels on a steep slope, when the human-powered vehicle 10 travels on a road surface with low frictional resistance, and when the human-powered vehicle 10 travels in a predetermined location where slippage is likely to occur, the control state of the motor 20a is switched from the second control state to the first control state. By switching the control state of the motor 20a from the second control state to the first control state, slippage can be effectively suppressed.

Sixth Embodiment
A control device 21 according to a sixth embodiment will be described. Fig. 10 is used to describe the control device 21 according to the sixth embodiment. The same reference numerals as those in the first to fifth embodiments are used for configurations common to the first to fifth embodiments, and duplicated descriptions will be omitted.

When the first condition is satisfied in the second control state, the control unit 21b switches the second control state to the first control state. In this embodiment, the first condition includes a condition related to the driving state. An example of a process for changing the control state is described. FIG. 10 is used to explain the example of the process for changing the control state. The control unit 21b starts a third control flow according to the flowchart shown in FIG. 10 when a predetermined condition is satisfied. When the third control flow ends, the control unit 21b repeatedly executes the third control flow at predetermined time intervals until the predetermined condition is satisfied. The conditions for starting the third control flow and the conditions for repeatedly executing the third control flow are the same as those in the fourth embodiment.

When the control unit 21b starts the first control flow, it transitions to step S21, and if the conditions related to the running state of the human-powered vehicle 10 are satisfied in the second control state, it transitions to step S22. If the conditions related to the running state of the human-powered vehicle 10 are not satisfied in the second control state, the control unit 21b ends the third control flow. The running state includes the rotational speed of the wheels 16 of the human-powered vehicle 10.

When the traveling state includes the rotation speed of the wheels 16 of the human-powered vehicle 10, the first condition is satisfied when the difference between the rotation speed of the front wheels 16a and the rotation speed of the rear wheels 16b is equal to or greater than a predetermined value. For example, the control unit 21b detects the rotation speed of the front wheels 16a based on a signal from a front wheel rotation sensor, and detects the rotation speed of the rear wheels 16b based on a signal from a rear wheel rotation sensor. The control unit 21b proceeds to step S22 when the difference between the rotation speed of the front wheels 16a and the rotation speed of the rear wheels 16b is equal to or greater than a predetermined value. The control unit 21b ends the third control flow when the difference between the rotation speed of the front wheels 16a and the rotation speed of the rear wheels 16b is less than a predetermined value.

When the control unit 21b proceeds to step S22, it controls the motor 20a in the first control state. After performing the process of step S22, the control unit 21b ends the third control flow.

By the control unit 21b executing the third control flow, the control state of the motor 20a is automatically switched from the second control state to the first control state when the drive wheels are slipping. For example, when the drive wheels are slipping, the rotation speed of the rear wheels 16b becomes faster than the rotation speed of the front wheels 16a by a predetermined value or more, and the control state of the motor 20a is switched from the second control state to the first control state. By switching the control state of the motor 20a from the second control state to the first control state, the control unit 21b can control the motor 20a to suppress slipping when the drive wheels are slipping.

Seventh Embodiment
A control device 21 according to the seventh embodiment will be described. Fig. 11 is used to describe the control device 21 according to the seventh embodiment. The same reference numerals as those in the first to sixth embodiments are used for configurations common to the first to sixth embodiments, and duplicated descriptions will be omitted.

When the first condition is satisfied in the second control state, the control unit 21b switches the second control state to the first control state. In this embodiment, the first condition includes a condition related to the operation of the operating device 26. The first condition is satisfied when the operating device 26 is operated.

An example of a process for changing the control state is described. FIG. 11 is used to describe the example of the process for changing the control state. The control unit 21b starts the fourth control flow according to the flowchart shown in FIG. 11 when a predetermined condition is satisfied. When the fourth control flow ends, the control unit 21b repeatedly executes the fourth control flow at predetermined time intervals until the predetermined condition is satisfied. The conditions for starting the fourth control flow and the conditions for repeatedly executing the fourth control flow are the same as those in the fourth embodiment.

When the control unit 21b starts the fourth control flow, the process proceeds to step S31, and when a condition related to the operation of the operation device 26 is satisfied in the second control state, the process proceeds to step S32. For example, when the control unit 21b detects that the user has performed a predetermined operation on the operation device 26 based on a signal from the operation device 26, the process proceeds to step S22. When a condition related to the operation of the operation device 26 is not satisfied in the second control state, the control unit 21b ends the fourth control flow. For example, when the control unit 21b does not detect that the user has performed a predetermined operation on the operation device 26, the process proceeds to step S32.

When the control unit 21b proceeds to step S32, it controls the motor 20a in the first control state. After performing the process of step S32, the control unit 21b ends the third control flow.

When the control unit 21b executes the fourth control flow, the control unit 21b can switch the control state of the motor 20a from the second control state to the first control state by the user operating the operating device 26, thereby improving convenience.

Eighth embodiment
The control device 21 of the eighth embodiment will be described. Fig. 12 is used to describe the control device 21 of the eighth embodiment. The same reference numerals as those in the first to seventh embodiments are used for configurations common to the first to seventh embodiments, and duplicated descriptions will be omitted.

In this embodiment, the control unit 21b is configured to control the motor 20a in the second control state when the second condition is satisfied in the first control state. An example of a process for changing the control state is described. FIG. 12 is used to explain the example of the process for changing the control state. The control unit 21b starts a fifth control flow according to the flowchart shown in FIG. 12 when a predetermined condition is satisfied. The fifth control flow shows an example of a process for switching the control state of the motor 20a from the first control state to the second control state.

The control unit 21b starts the fifth control flow, for example, when the control state of the motor 20a is switched from the second control state to the first control state. When the fifth control flow ends, the control unit 21b repeatedly executes the fifth control flow at predetermined time intervals until a predetermined condition is satisfied. In this embodiment, the control unit 21b repeatedly executes the fifth control flow until the control state of the motor 20a is switched from the first control state to the second control state.

When the control unit 21b starts the fifth control flow, the process proceeds to step S41, and if the second condition is satisfied in the first control state, the process proceeds to step S42. If the second condition is not satisfied in the first control state, the control unit 21b ends the fifth control flow. In this embodiment, the second condition is satisfied when a predetermined period of time has elapsed since the first condition was satisfied. The first condition includes, for example, a condition for switching the control state of the motor 20a from the first control state to the second control state. In this embodiment, the first condition is defined based on at least one of the driving environment of the human-powered vehicle 10, the driving state of the human-powered vehicle 10, and the operation of the operating device 26.

For example, if the first condition is defined based on the driving environment of the human-powered vehicle 10, the second condition is satisfied when a predetermined period of time has elapsed since the gradient of the road on which the human-powered vehicle 10 is traveling becomes equal to or greater than a predetermined value. If the first condition includes the driving environment of the human-powered vehicle 10, the second condition may be satisfied when a predetermined period of time has elapsed since the frictional resistance of the road surface of the road becomes equal to or less than a predetermined value. If the first condition includes the driving environment of the human-powered vehicle 10, the second condition may be satisfied when a predetermined period of time has elapsed since the location of the road becomes a predetermined location.

For example, if the first condition is defined based on the traveling state of the human-powered vehicle 10, the second condition is satisfied when a predetermined period of time has elapsed since the difference between the rotational speed of the front wheels 16a and the rotational speed of the rear wheels 16b becomes equal to or greater than a predetermined value.

For example, if the first condition is defined based on the operation of the operating device 26, the second condition is satisfied when a predetermined period of time has elapsed since a predetermined operation was performed on the operating device 26.

When the first condition is satisfied in the second control state, the control unit 21b proceeds to step S42 and controls the motor 20a in the second control state. After performing the process of step S42, the control unit 21b ends the fifth control flow.

By executing the fifth control flow, the control unit 21b can automatically switch from the second control state to the first control state, thereby improving convenience. In this embodiment, the control unit 21b does not switch the control state of the motor 20a from the first control state to the second control state unless a predetermined period has elapsed since the first condition is satisfied, thereby suppressing frequent changes in the control state of the motor 20a.

The second condition may be any condition different from the first condition. For example, the second condition may be satisfied before a predetermined period of time has elapsed since the first condition was satisfied. If the second condition is satisfied before a predetermined period of time has elapsed since the first condition was satisfied, the threshold value used in the second condition may be different from the threshold value used in the first condition. For example, if the first condition is satisfied when the gradient of the road is 25% or more, the second condition may be satisfied when the gradient of the road is 20%. By making the threshold value in the first condition and the threshold value in the second condition different from each other, the control unit 21b can suppress frequent changes in the control state of the motor 20a.

(Modification)
The description of each embodiment is merely an example of a form that the present invention can take, and is not intended to limit the present invention. For example, the present invention can take a form that combines at least two of the modified embodiments described below that are not mutually contradictory.

For example, the configuration of the control device 21 in each embodiment is an example, and the control device 21 may include various devices not shown in each embodiment, or may be configured not to include some of the various devices shown in each embodiment.

The various threshold values used in the control exemplified in each embodiment are not limited and may be set arbitrarily. The various threshold values may be changed arbitrarily by operating a predetermined operating device, etc.

The configurations illustrated in each embodiment may be combined with each other to the extent that they are not mutually inconsistent. The process contents and the process order of the flowcharts illustrated in each embodiment are merely examples, and the process contents and the process order can be changed as appropriate within the scope of the present invention.
For example, the control unit 21b may be configured to execute at least two of the four flowcharts shown in Figures 8 to 11. For example, the control unit 21b may be configured to execute the flowcharts shown in Figures 8 and 11 of the four flowcharts shown in Figures 8 to 11. For example, the control unit 21b may be configured to execute all of the flowcharts shown in Figures 8 to 11 of the four flowcharts shown in Figures 8 to 11.

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.

1...Human-powered vehicle, 11b...Crank arm, 19a...Motor, 16...Wheels, 16a...Front wheels, 16b...Rear wheels, 20...Control device, 20b...Control unit, 26...Operation device, F1...Human-powered driving force, F2...Assist force

In the control device of a third aspect according to the first or second aspect, when the control unit drives the motor in response to manual driving force, the control unit controls the motor so that the assist force is maximized within a range of the rotational phase of the crank arm within ±30 degrees from a second reference rotational phase at which the manual driving force is smallest during one rotation of the crank arm.
According to the control device of the third aspect, the assist force becomes maximum when the manual driving force input during one rotation of the crank arm becomes small, thereby further suppressing pulsation of the propulsion force of the human-powered vehicle, which includes the manual driving force and the assist force.

In the control device of the seventh aspect according to the sixth aspect, when the control unit drives the motor in accordance with the manual driving force in the first control state, the control unit controls the motor so that the assist force is maximized within a range of the rotational phase of the crank arm within ±30 degrees from the second reference rotational phase at which the manual driving force is smallest during one rotation of the crank arm.
According to the control device of the seventh aspect, in the first control state, when the manual driving force input during one rotation of the crank arm becomes small, the assist force becomes maximum, thereby further suppressing the pulsation of the propulsion force of the human-powered vehicle, which includes the manual driving force and the assist force.

When the control unit 21b drives the motor 20a in response to the manual driving force F1, the control unit 21b controls the motor 20a so that the assist force F2 is maximized within a range of the rotation phase of the crank arm 11b of ±30 degrees from the second reference rotation phase at which the manual driving force F1 is smallest during one rotation of the crank arm 11b. In this embodiment, when the control unit 21b drives the motor 20a in response to the manual driving force F1, the control unit 21b controls the motor 20a so that the assist force F2 is maximized when the rotation phase of the crank arm 11b is the second reference rotation phase. The second reference rotation phase includes 0 degrees, 180 degrees, and 360 degrees as shown in FIG. 4.

4, the control unit 21b detects a decrease in the manual driving force F1 when the rotation phase of the crank arm 11b is in the range of 270 degrees to 360 degrees. The control unit 21b controls the motor 20a so that the assist force F2 increases in the range of 270 degrees to 360 degrees.

Fourth Embodiment
A control device 21 according to a fourth embodiment will be described. The control device 21 according to the fourth embodiment will be described with reference to Figs. 3 to 8. The same reference numerals as those in the first to third embodiments are used for configurations common to the first to third embodiments, and duplicated descriptions will be omitted.

The front wheel rotation sensor is, for example, a magnetic sensor that detects the magnetism of a magnet provided on the front wheel 16a. The front wheel rotation sensor outputs a signal corresponding to the detection result of the rotation speed of the front wheel 16a to the control unit 21b. The rear wheel rotation sensor is, for example, a magnetic sensor that detects the magnetism of a magnet provided on the rear wheel 16b. The rear wheel rotation sensor outputs a signal corresponding to the rotation speed of the rear wheel 16b to the control unit 21b. The control unit 21b is configured to detect the rotation speed of the front wheel 16a and the rotation speed of the rear wheel 16b based on the signal corresponding to the rotation speed of the front wheel 16a and the signal corresponding to the rotation speed of the rear wheel 16b. The front wheel rotation sensor and the rear wheel rotation sensor may be, for example, a magnetic sensor or an optical sensor that detects a rotating member in which a plurality of holes are formed and arranged at a distance from each other in the circumferential direction of the wheel 16.

In the first control state, when the control unit 21b drives the motor 20a in response to the manual driving force F1, the control unit 21b controls the motor 20a so that the assist force F2 is minimum within a range of the rotation phase of the crank arm 11b of ±30 degrees from a first reference rotation phase at which the manual driving force F1 is maximum during one rotation of the crank arm 11b. In the first control state, when the control unit 21b drives the motor 20a in response to the manual driving force F1, the control unit 21b controls the motor 20a so that the assist force F2 is maximum within a range of the rotation phase of the crank arm 11b of ±30 degrees from a second reference rotation phase at which the manual driving force F1 is minimum during one rotation of the crank arm 11b.

When the control unit 21b starts the second control flow, the process proceeds to step S11, and if the conditions related to the driving environment of the human-powered vehicle 10 are satisfied in the second control state, the process proceeds to step S12. If the conditions related to the driving environment of the human-powered vehicle 10 are not satisfied in the second control state, the control unit 21b ends the second control flow. The driving environment includes at least one of the gradient of the road on which the human-powered vehicle 10 is traveling, the frictional resistance of the road surface of the road, and the location of the road.

When the control unit 21b starts the third control flow, the process proceeds to step S21, and if the conditions related to the running state of the human-powered vehicle 10 are satisfied in the second control state, the process proceeds to step S22. If the conditions related to the running state of the human-powered vehicle 10 are not satisfied in the second control state, the control unit 21b ends the third control flow. The running state includes the rotational speed of the wheels 16 of the human-powered vehicle 10.

When the control unit 21b starts the fourth control flow, the process proceeds to step S31, and when a condition related to the operation of the operation device 26 is satisfied in the second control state, the process proceeds to step S32. For example, the control unit 21b proceeds to step S32 when it detects that the user has performed a predetermined operation on the operation device 26 based on a signal from the operation device 26. The control unit 21b ends the fourth control flow when a condition related to the operation of the operation device 26 is not satisfied in the second control state. For example, the control unit 21b ends the fourth control flow when it does not detect that the user has performed a predetermined operation on the operation device 26.

When the process proceeds to step S32, the control unit 21b controls the motor 20a in the first control state. After performing the process of step S32, the control unit 21b ends the fourth control flow.

When the second condition is satisfied in the first control state, the control unit 21b proceeds to step S42 and controls the motor 20a in the second control state. After performing the process of step S42, the control unit 21b ends the fifth control flow.

By executing the fifth control flow, the control unit 21b can automatically switch from the first control state to the second control state, thereby improving convenience. In this embodiment, the control unit 21b does not switch the control state of the motor 20a from the first control state to the second control state unless a predetermined period has elapsed since the first condition is satisfied, thereby suppressing frequent changes in the control state of the motor 20a.

REFERENCE SIGNS LIST 10 ... human-powered vehicle, 11b... crank arm , 16 ... wheel, 16a... front wheel, 16b... rear wheel , 20a... motor , 21 ... control device, 21b ... control unit, 26... operation device, F1... human-powered driving force, F2... assist force

Claims (20)

A control device for a human-powered vehicle,
a control unit configured to control a motor that applies an assist force to the human-powered vehicle in response to a human-powered driving force input to a crank arm of the human-powered vehicle,
The control unit is
a control device that, when driving the motor in response to the manual driving force, controls the motor so that the assist force is minimized within a range of the rotational phase of the crank arm within ±30 degrees from a first reference rotational phase at which the manual driving force is maximized during one rotation of the crank arm. The control unit is
2. The control device according to claim 1, wherein, when the motor is driven in response to the manual driving force, the motor is controlled so that the assist force is minimized when the rotational phase of the crank arm is the first reference rotational phase. The control unit is
2. The control device according to claim 1, wherein when the motor is driven in response to the manual driving force, the motor is controlled so that the assist force is maximized within a range of a rotational phase of the crank within ±30 degrees from a second reference rotational phase at which the manual driving force is smallest during one rotation of the crank arm. The control unit is
4. The control device according to claim 3, wherein, when the motor is driven in response to the manual driving force, the motor is controlled so that the assist force becomes maximum when the rotational phase of the crank arm is the second reference rotational phase. The control unit is
2. The control device according to claim 1, wherein when the motor is driven in response to the manual driving force, the control device controls the motor so that the assist force is decreased when the manual driving force increases and the assist force is increased when the manual driving force decreases. The control unit is
configured to control the motor in a first control state and a second control state;
In the first control state, when the motor is driven in response to the manual driving force, the motor is controlled so that the assist force is minimized within a range of a rotational phase of the crank arm within ±30 degrees from a first reference rotational phase at which the manual driving force is maximized during one rotation of the crank arm.
2. The control device according to claim 1, wherein, in the second control state, when the motor is driven in response to the manual driving force, the motor is controlled so that the assist force is maximized within a range of the rotational phase of the crank arm within ±30 degrees from the first reference rotational phase during one rotation of the crank arm. The control unit is
7. The control device according to claim 6, wherein, when the motor is driven in response to the manual driving force in the first control state, the motor is controlled so that the assist force is maximized within a range of a rotational phase of the crank within ±30 degrees from a second reference rotational phase at which the manual driving force is smallest during one rotation of the crank arm. The control unit is
8. The control device according to claim 6 or 7, configured to switch a control state between the second control state and the first control state in response to at least one of a driving environment of the human-powered vehicle, a driving state of the human-powered vehicle, and an operation of an operating device of the human-powered vehicle. The control device according to claim 8, wherein the driving environment includes at least one of the gradient of the road on which the human-powered vehicle runs, the frictional resistance of the road surface of the road, and the location of the road. The control device according to claim 8, wherein the driving state includes the rotational speed of the wheels of the human-powered vehicle. The control device according to claim 9, wherein the control unit switches the second control state to the first control state when a first condition is satisfied in the second control state. The control device according to claim 11, wherein the first condition is satisfied when the gradient is equal to or greater than a predetermined value. The control device according to claim 11, wherein the first condition is satisfied when the frictional resistance is equal to or less than a predetermined value. The control device according to claim 11, wherein the first condition is satisfied when the location is a predetermined location. The control device according to claim 10, wherein the control unit switches the second control state to the first control state when a first condition is satisfied in the second control state. The wheels include front wheels and rear wheels,
The control device according to claim 15, wherein the first condition is satisfied when a difference between a rotation speed of the front wheels and a rotation speed of the rear wheels is equal to or greater than a predetermined value. The control device according to claim 8, wherein the control unit switches the second control state to the first control state when a first condition is satisfied in the second control state. The control device according to claim 17, wherein the first condition is satisfied when the operating device is operated. The control unit is
The controller of claim 6 , configured to control the motor in the second control state if a second condition is satisfied in the first control state. The control device according to claim 19, wherein the second condition is satisfied when a predetermined period of time has elapsed since the first condition was satisfied.

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