JP7809601B2 - Control device for human-powered vehicles - Google Patents

Description

The present invention relates to control device technology for human-powered vehicles.

For example, Patent Document 1 discloses a control device that controls the assist force in accordance with the manual driving force and the rotational state of the crank.

Patent No. 5575968

If the gear ratio of the front sprocket and rear sprocket is set to a relatively low ratio so that the user can start the human-powered vehicle with a light force, there is a risk that the cadence will not be within an appropriate range when the cruising speed of the human-powered vehicle is set to a relatively high speed range within the speed range that can be assisted by the motor. If the cruising speed of the human-powered vehicle is set to a relatively high speed range within the speed range that can be assisted by the motor, and the gear ratio is set to be within an appropriate range, the gear ratio will be relatively high. If the gear ratio is high, the user will need to apply a lot of force to each pedal when starting the human-powered vehicle.

The purpose of this disclosure is to provide a control device that can contribute to the comfortable driving of human-powered vehicles.

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 a plurality of control states related to adjustment of the assist force according to the driving state of the human-powered vehicle by human-powered driving force, wherein each of two or more of the plurality of control states includes a normal state and an increased assist force state in which the assist force is increased compared to the normal state, and the assist force is different in each of the normal states in the two or more control states, and wherein the control unit is configured to control the motor in the increased assist force state in each of the two or more control states and when the human-powered vehicle starts to move , wherein the plurality of control states includes a maximum assist state in which the assist force is at its maximum among the plurality of control states, and the maximum assist state is configured to exclude the increased assist force state in which the assist force is increasing .
According to the control device of the first aspect, even if the gear ratios of the front sprocket and rear sprocket are set so that the cadence falls within an appropriate range when the cruising speed of the human-powered vehicle is set to a relatively high speed range within the speed range in which assistance can be provided by the motor, the control device can increase the assist force more than in a normal state when the human-powered vehicle starts to move, thereby reducing the burden on the user and contributing to a comfortable ride of the human-powered vehicle. Furthermore, according to the control device of the first aspect, the control device can control the motor so as not to increase the assist force in a maximum assist state, which is the highest of the multiple control states. In the maximum assist state, it is considered that the user can start the human-powered vehicle with a light force, so the control device suppresses an excessive increase in the assist force and contributes to a comfortable ride of the human-powered vehicle.

In the control device of the second aspect according to the first aspect, the one assist force increasing state of the two or more control states includes another one of the two or more control states being a normal state or a maximum assist state.
According to the control device of the second aspect, the control device can increase the assist force when the human-powered vehicle starts to move by utilizing another normal state or maximum assist state among the two or more control states.

A control device according to a third 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 a plurality of control states related to adjustment of the assist force according to the driving state of the human-powered vehicle by human-powered force, wherein each of two or more of the plurality of control states includes a normal state and an increased assist force state in which the assist force is increased compared to the normal state, and the assist force differs in each of the normal states in the two or more control states, and the control unit is configured to be able to set one of the plurality of control states in accordance with a user's selection, and is configured to automatically select the increased assist force state from the increased assist force state and the normal state to control the motor in each of the two or more control states when the human-powered vehicle starts to move.
According to the control device of the third aspect, even if the gear ratios of the front sprocket and rear sprocket are set so that the cadence falls within an appropriate range when the cruising speed of a human-powered vehicle is set to a relatively high speed range within the speed range that can be assisted by the motor, the control device can increase the assist force more than normal when the human-powered vehicle starts to move, thereby reducing the burden on the user and contributing to a comfortable ride for the human-powered vehicle.

In a control device of a fourth aspect according to any one of the first to third aspects, the control unit is configured to control the motor according to the manual driving force, and in each of two or more control states, the maximum assist ratio of the assist force to the manual driving force in the increased assist force state is greater than the maximum assist ratio in the normal state.
According to the control device of the fourth aspect, when the human-powered vehicle starts to travel, the control device controls the motor in an increased assist force state in which the maximum assist ratio is greater than in the normal state, thereby reducing the burden on the user compared to the normal state. Thus, the control device can further contribute to a comfortable travel of the human-powered vehicle.

In a control device of a fifth aspect according to any one of the first to fourth aspects, the control unit is configured to control the motor according to the manual driving force, and in each of two or more control states, the rate of change of the assist force when the manual force decreases in the assist force increasing state is smaller than the rate of change of the assist force when the manual force decreases in the normal state.
According to the control device of the fifth aspect, when the human-powered vehicle starts to travel, the control device controls the motor in an assist force increasing state in which the rate of change in the assist force when human power decreases is smaller than in the normal state, thereby reducing the burden on the user compared to the normal state. Therefore, the control device can further contribute to a comfortable travel of the human-powered vehicle.

In a control device of a sixth aspect according to any one of the first to fifth aspects, in each of two or more control states, the upper limit value of the motor output torque in the assist force increasing state is greater than the upper limit value in the normal state.
According to the control device of the sixth aspect, when the human-powered vehicle starts to travel, the motor is controlled in an increased assist force state in which the upper limit of the motor output torque is higher than in the normal state, thereby reducing the burden on the user compared to the normal state. Thus, the control device can further contribute to a comfortable travel of the human-powered vehicle.

The control device of a seventh aspect according to any one of the first to sixth aspects is configured to control the motor in the normal state when a predetermined release condition is satisfied in the assist force increasing state.
According to the control device of the seventh aspect, when the release condition is satisfied, the control device can change the control state for controlling the motor from the increased assist force state to the normal state, thereby improving convenience.

A control device according to an eighth 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 a plurality of control states related to adjustment of the assist force according to the driving state of the human-powered vehicle by human-powered force, the plurality of control states including a first control state, a second control state in which the assist force is increased compared to the first control state, and a third control state in which the assist force is increased compared to the second control state, the control unit being configured to control the motor in either the second control state or the third control state when the first control state is selected and the human-powered vehicle starts to move, and being configured to control the motor in the third control state when the second control state is selected and the human-powered vehicle starts to move.
According to the control device of the eighth aspect, even if the gear ratios of the front sprocket and rear sprocket are set so that the cadence falls within an appropriate range when the cruising speed of the human-powered vehicle is set to a relatively high speed range within the speed range that can be assisted by the motor, the control device can reduce the burden on the user when the human-powered vehicle starts to move, regardless of whether the first control state or the second control state is selected, thereby contributing to a comfortable ride for the human-powered vehicle.

In the control device of the ninth aspect according to the eighth aspect, the control unit is configured to control the motor according to the manual driving force, and the maximum assist ratio of the assist force to the manual driving force in the third control state is greater than the maximum assist ratio in the first control state and the maximum assist ratio in the second control state.
According to the control device of the ninth aspect, regardless of whether the first control state or the second control state is selected, when the human-powered vehicle starts to move, the control device controls the motor in the third control state in which the maximum assist ratio is greater than that of the first control state and the second control state, thereby reducing the burden on the user and further contributing to a comfortable ride for the human-powered vehicle.

In the control device of the tenth aspect according to the eighth or ninth aspect, the braking control unit is configured to control the motor according to the manual driving force, and the rate of change of the assist force when the manual force decreases in the third control state is smaller than the rate of change of the assist force when the manual force decreases in the first control state and the rate of change of the assist force when the manual force decreases in the second control state.
According to the control device of the tenth aspect, when the human-powered vehicle starts to travel, the control device controls the motor in a third control state in which the rate of change of the assist force when human power decreases is smaller than in the first control state and the second control state, thereby reducing the burden on the user. Therefore, the control device can further contribute to a comfortable travel of the human-powered vehicle.

In the control device of the eleventh aspect according to any one of the eighth to tenth aspects, the upper limit value of the motor output torque in the third control state is greater than the upper limit value in the first control state and the upper limit value in the second control state.
According to the control device of the eleventh aspect, when the human-powered vehicle starts to travel, the control device controls the motor in a third control state in which the upper limit value of the motor's output torque is greater than in the first control state and the second control state, thereby reducing the burden on the user when the human-powered vehicle starts to travel. Thus, the control device can further contribute to a more comfortable travel of the human-powered vehicle.

In the control device of aspect 12 according to any one of aspects 8 to 11, the control unit is configured to control the motor in the first control state when a predetermined release condition is satisfied if the motor is controlled in either the second control state or the third control state when the first control state is selected and the human-powered vehicle starts to travel, and to control the motor in the second control state when a predetermined release condition is satisfied if the motor is controlled in the third control state when the second control state is selected and the human-powered vehicle starts to travel.
According to the control device of the twelfth aspect, when the release condition is satisfied, the control device can change the control state for controlling the motor to the first control state or the second control state, thereby improving convenience.

In the control device of a thirteenth aspect according to the seventh or twelfth aspect, the predetermined release condition includes a condition relating to a reduction in acceleration of the human-powered vehicle.
According to the control device of the thirteenth aspect, the control state of the motor is changed in accordance with conditions related to a decrease in acceleration of the human-powered vehicle, so the control device can further contribute to a comfortable driving experience for the human-powered vehicle.

In the control device of a fourteenth aspect according to any one of the seventh, twelfth and thirteenth aspects, the predetermined release condition includes a condition relating to a reduction in human power.
According to the control device of the fourteenth aspect, the control state of the motor is changed in accordance with conditions relating to a reduction in human power, so the control device can further contribute to a comfortable driving experience for the human-powered vehicle.

In the control device of aspect 15 according to any one of aspects 7, 12, 13, and 14, the control unit is configured to, when the speed of the human-powered vehicle is equal to or less than a predetermined speed, cause the motor to apply an assist force in accordance with the driving state of the human-powered vehicle by the human-powered driving force, and the predetermined release condition includes a condition related to the predetermined speed.
According to the control device of the fifteenth aspect, the control state of the motor is changed in accordance with predetermined speed-related conditions, so the control device can further contribute to a comfortable driving experience for the human-powered vehicle.

In the control device of the sixteenth aspect according to the fifteenth aspect, the predetermined release condition is satisfied when the speed of the human-powered vehicle reaches a predetermined speed, or when the speed of the human-powered vehicle reaches a value that is lower than the predetermined speed and is within a predetermined range in which the assist force is adjusted to decrease as the speed approaches the predetermined speed.
According to the control device of the sixteenth aspect, the control state of the motor is changed at the timing when the assist force is reduced, so the control device can further contribute to a comfortable driving experience for the human-powered vehicle.

In a seventeenth aspect of the control device according to any one of the seventeenth, twelfth, thirteenth, fourteenth, fifteenth, and sixteenth aspects, the predetermined release condition is satisfied when a predetermined time has elapsed since the human-powered vehicle started to travel.
According to the control device of the seventeenth aspect, the control device can appropriately control the motor in accordance with the time that has elapsed since the human-powered vehicle started to travel.

In the control device of aspect 18 according to any one of aspects 1 to 17, the human-powered vehicle includes a single-speed drivetrain.
According to the control device of the eighteenth aspect, the configuration of the human-powered vehicle can be simplified.

The control device disclosed herein can contribute to the comfortable driving of human-powered vehicles.

1 is a side view showing a drive train including a control device according to a first embodiment; FIG. 2 is a block diagram showing an example of a drive unit. 5A and 5B are diagrams showing the relationship between the manual driving force and the assist force in a plurality of control states. FIG. 4 is a diagram showing the relationship between the human-powered driving force and the assist force when the human-powered vehicle starts to travel. 4 is a flowchart showing a control flow in the first embodiment. FIG. 11 is a diagram showing the relationship between the manual driving force and the assist force in the second embodiment. FIG. 11 is a diagram showing the relationship between the rotation speed of the crankshaft and the assist force in the third embodiment. FIG. 11 is a diagram showing the relationship between the rotation speed of the crankshaft and the assist force in the fourth embodiment. FIG. 13 is a diagram showing the relationship between manual driving force and motor output torque in the fifth embodiment. 13 is a flowchart showing a control flow in the sixth embodiment. 13 is a flowchart showing a control flow in the seventh embodiment. FIG. 4 is a diagram showing the relationship between the vehicle speed of a human-powered vehicle and the assist force. 13 is a flowchart showing a control flow in the eighth embodiment. 13 is a flowchart showing a control flow in the ninth embodiment.

(First embodiment)
A drivetrain 1 including a control device 54 according to a first embodiment will be described. The drivetrain 1 will be described using FIGS. 1 to 5. In the following description, a predetermined direction in a human-powered vehicle will be described as the front-to-rear direction. The drivetrain 1 shown in FIG. 1 is provided in a human-powered vehicle.

A human-powered vehicle is a vehicle that has at least one wheel and can be propelled at least by human power. Human-powered vehicles include various types of bicycles, such as mountain bikes, road bikes, city bikes, cargo bikes, hand bikes, and recumbents. There is no limit to the number of wheels a human-powered vehicle has. Human-powered vehicles include, for example, unicycles and vehicles with two or more wheels. Human-powered vehicles are not limited to vehicles that can be propelled solely by human power. Human-powered vehicles include E-bikes that use not only human power but also the driving force of a motor 53 for propulsion. E-bikes include electrically assisted bicycles whose propulsion is assisted by a motor 53.

In this embodiment, the human-powered vehicle includes a bicycle with a total of two wheels: one front wheel and one rear wheel. In this specification, human-powered driving force may be referred to as human torque. In this specification, human-powered driving force may be referred to as human power rate.

The human-powered vehicle includes a single-speed drivetrain 1. The single-speed drivetrain 1 does not include a gear change mechanism. The human-powered vehicle may also include a multi-speed drivetrain instead of a single-speed drivetrain. The multi-speed drivetrain includes a gear change mechanism. The gear change mechanism includes, for example, at least one of a front derailleur, a rear derailleur, and an internal gear change mechanism.

The drivetrain 1 is configured to transmit human-powered driving force to one rear wheel or one front wheel. As shown in FIG. 1, the drivetrain 1 includes a front sprocket 10, a rear sprocket 20, a drive chain 30, and a drive unit 50.

The front sprocket 10 has a central axis of rotation. The front sprocket 10 is connected to the crankshaft 51 of the human-powered vehicle via the driving force transmission unit 52 of the drive unit 50. The driving force transmission unit 52 is configured to rotate relative to the frame of the human-powered vehicle around the central axis of rotation of the front sprocket. When the crankshaft 51 rotates, the driving force transmission unit 52 and the front sprocket 10 rotate integrally with each other. The crankshaft 51 and the driving force transmission unit 52 may be connected via a one-way clutch configured to rotate the driving force transmission unit 52 integrally when the crankshaft 51 rotates forward and to allow relative rotation between the crankshaft 51 and the driving force transmission unit 52 when the crankshaft 51 rotates backward. In this embodiment, the crankshaft 51 and the driving force transmission unit 52 are arranged coaxially, but they do not have to be arranged coaxially.

The rear sprocket 20 has a rear sprocket central axis of rotation. The rear sprocket 20 is configured to rotate relative to the frame of the human-powered vehicle around the rear sprocket central axis of rotation. The rear sprocket 20 is connected to the front sprocket 10 via a drive chain 30 so that the rear sprocket 20 rotates integrally with the rotation of the front sprocket 10.

The gear ratio of the front sprocket 10 and rear sprocket 20 is set to match the cruising speed at which the human-powered vehicle will travel when traveling on a flat, paved road, for example. The cruising speed is assumed to be a relatively high speed range within the range of speeds at which assistance is possible. When the gear ratio is set to match the cruising speed, the rider can rotate the crankshaft 51 at the optimal cadence at cruising speed, allowing the rider to travel the human-powered vehicle comfortably.

One rear wheel includes a hub shell 40. The hub shell 40 is configured to rotate relative to the frame of the human-powered vehicle around the central axis of rotation of the hub axle 61. The hub shell 40 is connected to the rear sprocket 20. Power is transmitted from the rear sprocket 20 to the hub shell 40. The hub shell 40 and rear sprocket 20 are connected via a one-way clutch. Driving force is transmitted from the rear sprocket 20 to the hub shell 40, providing propulsion to the human-powered vehicle.

The drive unit 50 is configured to assist in the propulsion of the human-powered vehicle. The drive unit 50 is provided near the crankshaft 51 of the human-powered vehicle. The drive unit 50 may be provided on the rear hub or the front hub of the human-powered vehicle. The drive unit 50 may also be provided on both the rear hub and the front hub of the human-powered vehicle. When the drive unit 50 is configured as a hub motor, the drive force transmission unit 52 is not included in the drive unit 50. As shown in Figures 1 and 2, the drive unit 50 includes the drive force transmission unit 52, a motor 53, and a control device 54. The motor 53 includes an electric motor.

In this embodiment, the motor 53 is configured to transmit driving force to a power transmission path for human-powered driving force from each pedal of the human-powered vehicle to one rear wheel. In this embodiment, the motor 53 is configured to transmit driving force to a power transmission path from the crankshaft of the human-powered vehicle to the front sprocket 10. The motor 53 may also be configured to transmit driving force to the drive chain 30 without passing through the front sprocket 10. The output torque of the motor 53 is transmitted to the power transmission path, thereby providing an assist force to the human-powered vehicle. In addition to the motor 53, the drive unit 50 may include a reducer disposed between the rotating shaft of the motor 53 and the power transmission path. The output torque of the motor 53 and the human-powered driving force are transmitted to the front sprocket 10 via the driving force transmission unit 52.

The control device 54 is a control device 54 for a human-powered vehicle and includes a control unit 54b configured to control the motor 53, which provides an assist force to the human-powered vehicle, in multiple control states related to adjusting the assist force, depending on the driving state of the human-powered vehicle by human-powered driving force. The control unit 54b is configured to drive the motor 53 depending on at least one of the human-powered driving force and the rotation speed of the crankshaft 51. In this embodiment, the control unit 54b is configured to control the motor 53 depending on the human-powered driving force.

The multiple control states include a first control state 1M, a second control state 2M in which the assist force is greater than in first control state 1M, and a third control state 3M in which the assist force is greater than in second control state 2M. For each control state, the magnitude of the assist force of the motor 53 relative to the magnitude of the manual driving force is specified, as shown in FIG. 3, for example. In this specification, the ratio of the assist force of the motor 53 to the manual driving force is referred to as the assist ratio. In this specification, the maximum value of the assist ratio is referred to as the maximum assist ratio.

Figure 2 shows an example of the control device 54. The control device 54 shown in Figure 2 includes a memory unit 53b and a control unit 54b. The memory unit 53b stores control programs and information used in the control process. The memory unit 53b includes, for example, at least one of non-volatile memory, volatile memory, and a hard disk.

The control unit 54b is configured to execute control related to the drive unit 50. The control unit 54b 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 54b may include one or more microcomputers. The control unit 54b further includes an inverter circuit connected to the motor 53.

The control unit 54b is configured to communicate with the vehicle speed sensor 62, driving force sensor 63, crank rotation sensor 64, acceleration sensor 65, and operation status sensor 66 via an electric cable or a wireless communication device. The vehicle speed sensor 62 is configured to detect information related to the vehicle speed of the human-powered vehicle. For example, the vehicle speed sensor 62 detects the rotational speed of at least one wheel of the human-powered vehicle. The vehicle speed sensor 62 is configured, for example, to be attached to the frame or front fork of the human-powered vehicle and to include a magnetic sensor that detects the magnetism of a magnet provided on at least one wheel. The vehicle speed sensor 62 outputs a signal corresponding to the rotational speed of at least one wheel to the control unit 54b. The control unit 54b is configured to detect the vehicle speed of the human-powered vehicle based on the signal output from the vehicle speed sensor 62.

The driving force sensor 63 is configured to detect information related to the human-powered driving force input to each pedal of the human-powered vehicle. The driving force sensor 63 is provided, for example, in the driving force transmission path from each pedal to the front sprocket 10. The driving force sensor 63 includes, for example, a strain sensor. The driving force sensor 63 may also include a magnetostrictive sensor, an optical sensor, and a pressure sensor. The driving force sensor 63 outputs a signal corresponding to the human-powered driving force applied to each pedal to the control unit 54b. The control unit 54b is configured to detect the human-powered driving force based on the signal output from the driving force sensor 63.

The crank rotation sensor 64 is configured to detect information related to the rotational speed of the crankshaft 51 of the human-powered vehicle. The rotational speed of the crankshaft 51 includes, for example, the rotational speed of the crankshaft 51 relative to the frame of the human-powered vehicle. The crank rotation sensor 64 includes, for example, a magnetic sensor that outputs a signal according to the strength of a magnetic field. The crank rotation sensor 64 is provided, for example, on the crankshaft 51 or on the power transmission path from the crankshaft 51 to the front sprocket 10. The crank rotation sensor 64 outputs a signal according to the rotational speed of the crankshaft 51 to the control unit 54b. The control unit 54b is configured to detect the rotational speed of the crankshaft 51 based on the signal output from the crank rotation sensor 64.

The acceleration sensor 65 is configured to detect information related to the acceleration of the human-powered vehicle. The acceleration sensor 65 outputs a signal corresponding to the forward acceleration of the human-powered vehicle to the control unit 54b. The control unit 54b is configured to detect the acceleration of the human-powered vehicle based on the signal output from the acceleration sensor 65. The acceleration sensor 65 may include a vehicle speed sensor 62. If the acceleration sensor 65 includes the vehicle speed sensor 62, the control unit 54b may detect the acceleration of the human-powered vehicle by differentiating the vehicle speed of the human-powered vehicle.

The operation status sensor 66 is configured to detect information related to the operation status of the operation unit that operates the drive unit 50. The operation unit includes at least one of a button, a touch panel, and a lever. In this embodiment, the operation unit is used when the user selects one of multiple control states related to adjusting the assist force, for example. The operation status sensor 66 outputs a signal corresponding to the operation status of the operation unit to the control unit 54b. The control unit 54b is configured to detect the operation status of the operation unit based on the signal output from the operation status sensor 66.

The control unit 54b is configured to communicate with the motor 53 via an electric cable or a wireless communication device. The control unit 54b is configured to control the motor 53 by outputting a signal to the motor 53. When the motor 53 is driven under the control of the control unit 54b, an assist force is applied to the human-powered vehicle. In this embodiment, the control unit 54b is configured to apply an assist force from the motor 53 in accordance with the driving state of the human-powered vehicle due to the human-powered driving force when the vehicle speed of the human-powered vehicle is below a predetermined speed. The predetermined vehicle speed is stipulated, for example, based on a specific law.

The memory unit 53b stores information related to multiple control states 1M, 2M, and 3M related to the adjustment of the assist force. The multiple control states 1M, 2M, and 3M, as shown in the example in Figure 3, define the magnitude of the assist force relative to the magnitude of the human-powered driving force input to the human-powered vehicle. The control unit 54b adjusts the assist force based on one of the multiple control states 1M, 2M, and 3M selected by the user.

When adjusting the assist force, if the manual driving force increases or decreases, the control unit 54b increases or decreases the assist force so that it follows one of the multiple graphs shown in FIG. 3 that corresponds to one control state selected by the user. Information regarding the user's selection of one control state is stored in the memory unit 53b. The control unit 54b is configured to update the information regarding the user's selection of one control state based on a signal from the operation state sensor 66.

An example of multiple control states 1M, 2M, and 3M will be described using Figure 3. The assist force shown in Figure 3 is determined, for example, by at least one of the output torque of motor 53 and the power of motor 53. The power of motor 53 is determined by the product of the output torque of motor 53 and the rotational speed of motor 53. The assist force may also be determined, for example, by at least one of the output torque of the reducer and the power of the reducer.

Of the multiple control states, two or more control states each include a normal state and an increased assist force state in which the assist force is greater than in the normal state. In this embodiment, of the three control states 1M, 2M, and 3M, two control states 1M and 2M each include a normal state and an increased assist force state. The first control state 1M includes a normal state 11M and an increased assist force state 12M. The second control state 2M includes a normal state 21M and an increased assist force state 22M.

The multiple control states include a maximum assist state in which the assist force is the greatest among the multiple control states. In this embodiment, the three control states 1M, 2M, and 3M include a third control state 3M in which the assist force is the greatest among the three control states 1M, 2M, and 3M. In this specification, the third control state 3M may be referred to as a maximum assist state. The maximum assist state does not include an increased assist force state in which the assist force increases. In this embodiment, the third control state 3M includes a normal state, but, unlike the two control states 1M and 2M, does not include an increased assist force state in which the assist force increases. In this specification, the third control state 3M may be referred to as a normal state 31M.

The control unit 54b is configured to control the motor 53 in the normal state in each of the multiple control states 1M, 2M, and 3M, and in any case other than when the human-powered vehicle starts moving. The control unit 54b adjusts the assist force based on the normal state of one control state selected from the multiple control states 1M, 2M, and 3M, in any case other than when the human-powered vehicle starts moving.

The control unit 54b is configured to control the motor 53 in the increased assist force state in each of two or more control states, and when the human-powered vehicle starts traveling. When the human-powered vehicle starts traveling and one of the two control states 1M and 2M is selected, the control unit 54b adjusts the assist force based on the increased assist force state of the selected control state. When the human-powered vehicle starts traveling and control state 3M is selected, the control unit 54b adjusts the assist force based on the normal state of control state 3M.

Using Figure 3, normal states 11M, 21M, and 31M of multiple control states 1M, 2M, and 3M are explained. The assist force differs in each normal state of two or more control states. In this embodiment, the assist force differs from one another in the normal states 11M, 21M, and 31M of the three control states 1M, 2M, and 3M.

As shown in FIG. 3, in normal states 11M, 21M, and 31M, the control unit 54b causes the motor 53 to start applying an assist force at the same timing. In this embodiment, in normal states 11M, 21M, and 31M, when the manual driving force starts to be input and reaches a predetermined assist start threshold 10T, the control unit 54b causes the motor 53 to start applying an assist force. The predetermined assist start threshold 10T is, for example, 5 Nm.

In normal state 11M, control unit 54b increases the assist force of motor 53 so that the assist ratio increases as the manual driving force increases from the assist start threshold 10T until the manual driving force reaches first threshold 11T. The assist ratio in normal state 11M is maximum when the manual driving force is at first threshold 11T. In normal state 11M, control unit 54b causes motor 53 to maintain an assist force of first maximum assist force 11P when the manual driving force is equal to or greater than first threshold 11T.

In normal state 21M, control unit 54b increases the assist force of motor 53 so that the assist ratio increases as the manual driving force increases from the assist start threshold 10T until the manual driving force reaches a second threshold 21T that is smaller than the first threshold 11T. The assist ratio in normal state 21M is maximum when the manual driving force is equal to or greater than the second threshold 21T. In normal state 21M, when the manual driving force is equal to or greater than the second threshold 21T, control unit 54b causes motor 53 to maintain an assist force of a second maximum assist force 21P that is larger than the first maximum assist force 11P.

In normal state 21M, the rate of change in the assist ratio is greater than in normal state 11M until the assist force reaches its maximum value. The maximum assist ratio in normal state 21M is greater than the maximum assist ratio in normal state 11M. When the manual driving force is equal to or greater than the assist start threshold 10T, the assist force relative to the manual driving force is greater in normal state 21M than in normal state 11M. When compared to normal state 11M, normal state 21M is configured so that the assist force is greater than that in normal state 11M.

In normal state 31M, control unit 54b increases the assist force of motor 53 so that the assist ratio increases as the manual driving force increases from the assist start threshold 10T until the manual driving force reaches a third threshold 3T, which is smaller than the second threshold 21T. The assist ratio in normal state 31M is maximum when the manual driving force is equal to or greater than the third threshold 3T. In normal state 31M, when the manual driving force is equal to or greater than the third threshold 3T, control unit 54b causes motor 53 to maintain an assist force of a third maximum assist force 3P, which is the same magnitude as the second maximum assist force 21P.

In normal state 31M, the rate of change in the assist ratio until the assist force reaches its maximum value is greater than in normal state 21M. The maximum assist ratio of the assist force to the manual driving force in third control state 3M is greater than the maximum assist ratio in first control state 1M and the maximum assist ratio in second control state 2M. In this embodiment, the maximum assist ratio in normal state 31M of third control state 3M is greater than the maximum assist ratio in normal state 11M of first control state 1M and the maximum assist ratio in normal state 21M of second control state 2M. When the manual driving force is equal to or greater than the assist start threshold 10T and less than the second threshold 21T, the assist force relative to the manual driving force is greater in normal state 31M than in normal state 21M. Compared to normal state 21M, normal state 31M is configured so that the assist force is greater than that in normal state 21M.

The assist force increased states 12M, 22M of the multiple control states 1M, 2M are explained using Figure 4. One of the two or more control states includes either the normal state or the maximum assist state of another of the two or more control states. When the first control state 1M is selected and the human-powered vehicle starts traveling, the control unit 54b is configured to control the motor 53 in either the second control state 2M or the third control state 3M. When the second control state 2M is selected and the human-powered vehicle starts traveling, the control unit 54b is configured to control the motor 53 in the third control state 3M.

In this embodiment, the assist force increased state 12M of one of the two control states 1M and 2M, control state 1M, includes the normal state 21M of the other control state 2M. When first control state 1M is selected and the human-powered vehicle starts traveling, control unit 54b is configured to control motor 53 in second control state 2M. The assist force increased state 12M of first control state 1M is configured so that the graph showing the relationship of the assist force to the human-powered driving force shown in FIG. 3 matches the normal state 21M of second control state 2M. When control state 1M is selected when the human-powered vehicle starts traveling, control unit 54b adjusts the assist force based on the normal state 21 of control state 2M as the assist force increased state 12M of control state 1M.

Figure 4 shows an example different from the example shown in Figure 3. The assist force increasing state 12M of control state 1M includes the normal state 31M of another control state 3M. When first control state 1M is selected and the human-powered vehicle starts traveling, the control unit 54b is configured to control the motor 53 in the third control state 3M. The assist force increasing state 12M of the first control state 1M is configured so that the graph showing the relationship between the assist force and the human-powered driving force shown in Figure 4 matches the normal state 31M of the third control state 3M. When control state 1M is selected when the human-powered vehicle starts traveling, the control unit 54b adjusts the assist force based on the normal state 31 of the control state 3M as the assist force increasing state 12M of the control state 1M. The user can select which of the examples shown in Figure 3 or Figure 4 is to be adopted, for example, using the operation unit.

As shown in FIG. 3, in this embodiment, the assist force increased state 22M of one of the two control states 1M and 2M, control state 2M, includes the normal state 31M of the other control state 3M. The assist force increased state 22M of second control state 2M is configured so that the graph showing the relationship of assist force to human-powered driving force shown in FIG. 3 matches the normal state 31M of third control state 3M. When control state 2M is selected when the human-powered vehicle starts traveling, the control unit 54b adjusts the assist force based on the third control state 3M, which has the greatest assist force among the multiple control states 1M, 2M, and 3M, as the assist force increased state 22M of control state 2M.

In each of two or more control states, the maximum assist ratio of the assist force to the manual driving force in the assist force increasing state is greater than the maximum assist ratio in the normal state. In this embodiment, in control state 1M, the graph shown in FIG. 3 for assist force increasing state 12M matches the normal state 21M of second control state 2M, so the maximum assist ratio in assist force increasing state 12M is greater than the maximum assist ratio in normal state 11M. In this embodiment, in control state 2M, the graph shown in FIG. 3 for assist force increasing state 22M matches the normal state 31M of third control state 3M, so the maximum assist ratio in assist force increasing state 22M is greater than the maximum assist ratio in normal state 21M.

The control unit 54b is configured to control the motor 53 in the normal state 11M or 21M when a predetermined release condition is satisfied in the assist force increased state 12M or 22M. For example, when the first control state 1M is selected and the human-powered vehicle starts traveling, the control unit 54b controls the motor 53 in either the second control state 2M or the third control state 3M, and when a predetermined release condition is satisfied, the control unit 54b is configured to control the motor 53 in the first control state 1M. When the second control state 2M is selected and the human-powered vehicle starts traveling, the control unit 54b controls the motor 53 in the third control state 3M, and when a predetermined release condition is satisfied, the control unit 54b is configured to control the motor 53 in the second control state 2M.

An example of control performed by the control unit 54b will now be described. Figures 3 to 5 will be used to explain this example of control performed by the control unit 54b. The control unit 54b starts a first control flow according to the flowchart shown in Figure 5 when predetermined conditions are met. In this embodiment, the control unit 54b starts the first control flow when power starts to be supplied to the drive unit 50 from a predetermined power source. When the first control flow ends, the control unit 54b repeatedly executes the first control flow at predetermined time intervals until the predetermined conditions are met. In this embodiment, the control unit 54b repeatedly executes the first control flow until power is no longer supplied to the drive unit 50.

In step S1, the control unit 54b detects that the human-powered vehicle has started to move. The control unit 54b detects that the human-powered vehicle has started to move, for example, based on the vehicle speed and human-powered driving force of the human-powered vehicle.

An example of the processing of step S1 will now be described. The control unit 54b acquires the vehicle speed of the human-powered vehicle based on a signal from the vehicle speed sensor 62. The control unit 54b acquires the human-powered driving force based on a signal from the driving force sensor 63. The control unit 54b detects that the human-powered vehicle has started to move when the vehicle speed of the human-powered vehicle is less than a predetermined speed and the human-powered driving force is greater than the predetermined driving force. The control unit 54b may also detect that the human-powered vehicle has started to move based on information other than the vehicle speed and human-powered driving force of the human-powered vehicle. If the human-powered vehicle has started to move, the control unit 54b proceeds to step S2. If the human-powered vehicle has not started to move, the control unit 54b ends the first control flow.

In step S2, if the control state selected by the user from among the multiple control states 1M, 2M, and 3M is the first control state 1M or the second control state 2M, the control unit 54b proceeds to step S3. If the control state selected by the user is the third control state 3M, the control unit 54b terminates the first control flow.

In step S3, the control unit 54b controls the motor 53 in the assist force increased state 12M or 22M. For example, if the control state selected by the user is the first control state 1M, the control unit 54b controls the motor 53 in the assist force increased state 12M. For example, if the control state selected by the user is the second control state 2M, the control unit 54b controls the motor 53 in the assist force increased state 22M.

For example, as shown in FIG. 4, if the graphs of the assist force increasing states 12M and 22M match the graph of the third control state 3M, the control unit 54b controls the motor 53 in the third control state 3M regardless of whether the first control state 1M or the second control state 2M is selected. By controlling the control unit 54b in step S3, the third control state 3M can be used to increase the assist force more than in the normal states 11M and 21M. As shown in FIG. 5, the control unit 54b performs the processing of step S4 and then proceeds to step S4.

In step S4, if a predetermined cancellation condition is satisfied, the control unit 54b proceeds to step S5. If the predetermined cancellation condition is not satisfied, the control unit 54b repeatedly executes step S4 until the predetermined cancellation condition is satisfied. The predetermined cancellation condition is satisfied, for example, when the user performs a predetermined operation on the operation unit.

In step S5, the control unit 54b controls the motor 53 in normal states 11M and 21M. For example, if the control state selected by the user is the first control state 1M, the control unit 54b controls the motor 53 in normal state 11M shown in FIG. 3. If the control state selected by the user is the second control state 2M, the control unit 54b controls the motor 53 in normal state 21M. After performing the processing of step S5, the control unit 54b ends the first control flow.

When the human-powered vehicle starts traveling in the first control state 1M, the control unit 54b executes the first control flow to switch the control state for controlling the motor 53 from the normal state 11M to the assist force increased state 12M. By switching from the normal state 11M to the assist force increased state 12M, the assist force can be increased more than when the motor 53 is controlled in the normal state 11M. When the human-powered vehicle starts traveling in the second control state 2M, as in the first control state 1M, the control state is switched from the normal state 21M to the assist force increased state 22M, so the assist force can be increased more than when the motor 53 is controlled in the normal state 21M.

By increasing the assist force when the human-powered vehicle starts to move, the user can pedal with a relatively light force, even when the gear ratio of the front sprocket 10 and rear sprocket 20 is relatively high, thereby reducing the burden on the user. By reducing the burden on the user and suppressing an increase in cadence, the control device 54 can contribute to a comfortable ride for the human-powered vehicle. When the gear ratio is relatively high, an increase in cadence can be suppressed when the human-powered vehicle is driven at a relatively high speed within the speed range that can be assisted by the motor 53.

In the third control state 3M, it is believed that the user can start driving the human-powered vehicle with a light force, and so although it includes the normal state 31M, unlike the other two control states 1M and 2M, it does not include an increased assist force state. Because the third control state 3M does not include an increased assist force state, even when the first control flow is executed, the assist force does not increase more than in the normal state 31M. By having the control unit 54b execute the first control flow in the third control state 3M, which does not increase the assist force more than in the normal state 31M, excessive increases in the assist force can be suppressed, and the control device 54 can contribute to a comfortable driving experience for the human-powered vehicle.

In this embodiment, the user can select one of three control states 1M, 2M, and 3M, but the number of control states the user can select is not limited to three. The number of control states the user can select may be two, four, or more.

In the first control flow, when the third control state 3M is selected, the control unit 54b may control the motor 53 so that the assist force is greater than that in the normal state 31M, as in the first control state 1M and the second control state 2M. By the control unit 54b controlling the motor 53 so that the assist force in the third control state 3M is greater than that in the normal state 31M, the user can pedal relatively easily when starting to drive the human-powered vehicle.

Second Embodiment
A control device 54 according to a second embodiment will be described. Fig. 6 will be used to describe the control device 54 according to the second embodiment. Components common to the first embodiment will be assigned the same reference numerals as those in the first embodiment, and redundant description will be omitted.

As shown in FIG. 6 , in this embodiment, the relationship between the manual driving force and the assist force in the assist force increasing state 12M of the first control state 1M does not match the normal state 21M of the second control state 2M or the normal state 31M of the third control state 3M. In the assist force increasing state 12M, the assist ratio increases as the manual driving force increases from the assist start threshold 10T until the manual driving force reaches the first increase threshold 12T. The assist force is maintained at the first maximum assist force 11P when the manual driving force is equal to or greater than the first increase threshold 12T. The assist ratio in the assist force increasing state 12M is maximum when the manual driving force is equal to or greater than the first increase threshold 12T.

The first increase threshold 12T is smaller than the first threshold 11T that defines the maximum assist ratio in the normal state 11M of the first control state 1M, and is greater than the second threshold 21T that defines the maximum assist ratio in the normal state 21M of the second control state 2M.

The maximum assist ratio in the increased assist force state 12M is greater than the maximum assist ratio in the normal state 11M. The maximum assist ratio in the increased assist force state 12M is less than the maximum assist ratio in the normal state 21M. Because the maximum assist ratio in the increased assist force state 12M is greater than the maximum assist ratio in the normal state 11M and less than the maximum assist ratio in the normal state 21M, excessive increases in assist force can be suppressed, and the control device 54 can contribute to comfortable driving of the human-powered vehicle.

The assist force increasing state 22M of the second control state 2M does not match the relationship between the manual driving force and the assist force in the normal state 31M of the third control state 3M. In the assist force increasing state 22M, the assist ratio increases as the manual driving force increases from the assist start threshold 10T until the manual driving force reaches the second increase threshold 22T. The assist force is maintained at the second maximum assist force 21P when the manual driving force is equal to or greater than the second increase threshold 22T. The assist ratio in the assist force increasing state 22M is maximum when the manual driving force is equal to the second increase threshold 22T. The second increase threshold 22T is smaller than the second threshold 21T and larger than the third threshold 3T that defines the maximum assist ratio in the normal state 31M of the third control state 3M.

The maximum assist ratio in the assist force increasing state 22M is greater than the maximum assist ratio in the normal state 21M. The maximum assist ratio in the assist force increasing state 22M is less than the maximum assist ratio in the normal state 31M. Because the maximum assist ratio in the assist force increasing state 22M is greater than the maximum assist ratio in the normal state 21M and less than the maximum assist ratio in the normal state 31M, excessive increases in assist force can be suppressed, and the control device 54 can contribute to comfortable driving of the human-powered vehicle.

(Third embodiment)
A control device 54 according to a third embodiment will be described. The control device 54 according to the third embodiment will be described with reference to Figures 3, 5, and 7. The same reference numerals as those in the first and second embodiments are used for the components common to the first and second embodiments, and redundant description will be omitted.

As shown in FIG. 3, in this embodiment, the relationship between the manual driving force and the assist force in the increased assist force state 12M in the first control state 1M is the same as that in the normal state 21M in the second control state 2M. The relationship between the manual driving force and the assist force in the increased assist force state 22M in the second control state 2M is the same as that in the normal state 31M in the third control state 3M.

As shown in FIG. 3, normal states 11M, 21M, and 31M have different relationships between the manual driving force and the assist force. Normal states 11M, 21M, and 31M have different rates of change in the assist force. In this embodiment, the rate of change in the assist force indicates the ratio of the rate of change in the output of motor 53 to the rate of change in the manual torque. The greater the rate of change in the assist force, the greater the rate of change in the assist force relative to a change in the manual torque. Unlike this embodiment, the greater the rate of change in the assist force, the less the rate of change in the assist force relative to a change in the manual power. The manual power is defined by the product of the manual torque and the rotational speed of the crank.

The graph of manual torque 1H shown in Figure 7 shows an example of how manual torque changes depending on the rotation angle of the crankshaft. In Figure 7, manual torque 1H increases from 0°, which indicates the top dead center of one pedal, until the rotation angle of the crankshaft reaches 90°. In Figure 7, manual torque 1H decreases from 90° to 180° as the rotation angle of the crankshaft reaches 180°.

The graphs of the multiple control states 1M, 2M, and 3M shown in Figure 7 show an example of changes in the assist force when the manual torque 1H changes as shown in Figure 7 in the multiple control states 1M, 2M, and 3M. In each of the multiple control states 1M, 2M, and 3M, the rate of change in the assist force when the manual torque 1H decreases is smaller than the rate of change in the assist force when the manual torque 1H increases, so the assist force is less likely to decrease even when the manual torque 1H decreases. Because the assist force is less likely to decrease even when the manual torque 1H decreases, the user can easily pedal each pedal.

The magnitude relationship between the rate of change of the assist force when the manual driving force decreases and the rate of change of the assist force when the manual driving force increases is determined, for example, according to the magnitude relationship of a predetermined change parameter. In this embodiment, the change parameter includes the time constant of a first-order low-pass filter. The change parameter may include a parameter different from the time constant of the first-order low-pass filter.

When the change parameter includes the time constant of a first-order low-pass filter, the control unit 54b corrects the manual torque by processing the signal output from the driving force sensor 63 using a first-order low-pass filter. The control unit 54b calculates the assist force in multiple control states 1M, 2M, and 3M based on the corrected manual torque. In each of the multiple control states 1M, 2M, and 3M, when the manual torque 1H decreases, the control unit 54b corrects the assist force using a time constant that is larger than when the manual torque 1H increases, thereby making it difficult for the assist force to decrease even when the manual torque 1H decreases.

Figure 7 explains the magnitude relationship of the change in assist force in the multiple control states 1M, 2M, and 3M. As shown in Figure 7, the rate of change in assist force when human power decreases in the third control state 3M is smaller than the rate of change in assist force when human power decreases in the first control state 1M and the rate of change in assist force when human power decreases in the second control state 2M. Because the rate of change in assist force in the normal state 31M of the third control state 3M is smaller than the normal state 11M of the first control state 1M and the normal state 21M of the second control state 2M, even if the human-power torque 1H decreases in the normal state 31M of the third control state 3M, a relatively high assist force is imparted to the human-powered vehicle.

In each of two or more control states 1M, 2M, the rate of change in the assist force when the human power decreases in the assist force increasing state 12M, 22M is smaller than the rate of change in the assist force when the human power decreases in the normal state 11M, 21M. In this embodiment, the rate of change in the assist force when the human power decreases in the assist force increasing state 12M of the first control state 1M matches the normal state 21M of the second control state 2M. In the first control state 1M, the rate of change in the assist force when the human power decreases in the assist force increasing state 12M is smaller than the rate of change in the assist force when the human power decreases in the normal state 11M. The rate of change in the assist force when the assist force increases in the assist force increasing state 22M of the second control state 2M matches the normal state 31M of the third control state 3M. In the second control state 2M, the rate of change in the assist force when the human power decreases in the assist force increasing state 22M is smaller than the rate of change in the assist force when the human power decreases in the normal state 21M.

For example, if the relationship of the assist force to the manual driving force shown in Figure 4 and the rate of change of the assist force are the same in the assist force increasing states 12M, 22M and the normal state 31M of the third control state 3M, the graph of the assist force increasing states 12M, 22M in Figure 7 will be the same as the graph of the normal state 31M of the third control state 3M.

The rate of change in assist force when human power decreases in normal state 31M of third control state 3M is smaller than in normal state 11M of first control state 1M and normal state 21M of second control state 2M. Therefore, even if human power decreases when the human-powered vehicle starts to move in first control state 1M or second control state 2M, a relatively high assist force can be applied to the human-powered vehicle. By being able to apply a relatively high assist force, the user can pedal with less force than when the motor 53 is controlled in normal states 11M and 21M, thereby reducing the burden on the user.

When the human-powered vehicle starts traveling in the normal state 31M of the third control state 3M, the control unit 54b may temporarily update the rate of change in the assist force when human power decreases to a smaller value. By updating the rate of change in the assist force, a relatively high assist force can be applied to the human-powered vehicle in the third control state 3M, thereby reducing the burden on the user.

(Fourth embodiment)
A control device 54 according to a fourth embodiment will be described. The control device 54 according to the fourth embodiment will be described with reference to Figs. 3, 5, and 8. The same reference numerals as those in the first to third embodiments are used for the components common to the first to third embodiments, and redundant description will be omitted.

In this embodiment, the relationship between the manual driving force and the assist force in the normal state 11M and the increased assist force state 12M in the first control state 1M is the same as that in the normal state 31M in the third control state 3M, as shown in FIG. 3. The relationship between the manual driving force and the assist force in the normal state 21M and the increased assist force state 22M in the second control state 2M is the same as that in the normal state 31M in the third control state 3M. Because the relationships between the manual driving force and the assist force are the same, the maximum assist ratios in the normal states 11M, 21M, and 31M and the maximum assist ratios in the increased assist force states 12M and 22M are equal to each other.

In this embodiment, the two or more control states 1M, 2M have different rates of change in the assist force when human power decreases in the normal states 11M, 21M and the increased assist force states 12M, 22M. The normal states 11M, 21M, 31M of the multiple control states 1M, 2M, 3M have different rates of change in the assist force when human power decreases. Figure 8 shows an example of the rate of change in the assist force in the multiple control states 1M, 2M, 3M of this embodiment.

As shown in Figure 8, the rate of change in assist force when human power decreases in normal state 21M of second control state 2M is smaller than the rate of change in assist force when human power decreases in normal state 11M of first control state 1M. Because the rate of change in assist force in normal state 21M of second control state 2M is smaller than in normal state 11M of first control state 1M, even if human power decreases in normal state 21M, a higher assist force is applied to the human-powered vehicle than in normal state 11M.

The rate of change in assist force when human power decreases in normal state 31M of third control state 3M is smaller than the rate of change in assist force when human power decreases in normal state 11M of first control state 1M and normal state 21M of second control state 2M. Because the rate of change in assist force in normal state 31M of third control state 3M is smaller than in normal state 11M of first control state 1M and normal state 21M of second control state 2M, even if human power decreases in normal state 31M, a higher assist force is applied to the human-powered vehicle than in normal state 11M and normal state 21M.

In the assist force increasing state 12M of the first control state 1M, the rate of change in the assist force when human power decreases is the same as in the normal state 21M. In the assist force increasing state 22M of the second control state 2M, the rate of change in the assist force when human power decreases is the same as in the normal state 31M. When the human-powered vehicle starts to travel in the first control state 1M or the second control state 2M, control by the control unit 54b allows a higher assist force to be applied to the human-powered vehicle than in the normal state 11M, even if human power decreases when the human-powered vehicle starts to travel.

In this embodiment, the multiple control states 1M, 2M, and 3M have the same relationship between the manual driving force and the assist force as shown in Figure 3. Even when the relationship between the manual driving force and the assist force is the same, the assist forces in normal states 11M, 21M, and 31M can be configured to be different from one another by setting the rate of change of the assist force to different values in normal states 11M, 21M, and 31M.

Fifth Embodiment
A control device 54 according to a fifth embodiment will be described. The control device 54 according to the fifth embodiment will be described with reference to Figs. 3, 5, and 9. The same reference numerals as those in the first to fourth embodiments will be used to designate components common to the first to fourth embodiments, and redundant description will be omitted.

In this embodiment, the relationship between the manual driving force and the output torque in the assist force increasing state 12M in the first control state 1M is the same as that in the normal state 21M in the second control state 2M. The relationship between the manual driving force and the output torque in the assist force increasing state 22M in the second control state 2M is the same as that in the normal state 31M in the third control state 3M. The relationships between the manual driving force and the output torque in the first control state 1M, second control state 2M, and third control state 3M are different from one another.

The relationship between manual driving force and output torque in multiple control states 1M, 2M, and 3M is explained using Figure 9. In Figure 9, the upper limit value of motor output in normal state 11M of first control state 1M is shown as first upper limit value 11V. The upper limit value of motor output in normal state 21M of second control state 2M is shown as second upper limit value 21V. The upper limit value of motor output in normal state 31M of third control state 3M is shown as third upper limit value 3V. As shown in Figure 9, because second upper limit value 21V is greater than first upper limit value 11V, when motor 53 is controlled in normal state 21M of second control state 2M, the assist force can be increased compared to normal state 11M of first control state 1M.

In each of the two or more control states 1M, 2M, the upper limit value of the output torque of the motor 53 in the assist force increasing state 12M, 22M is greater than the upper limit value of the output torque of the motor 53 in the normal state 11M, 21M. In this embodiment, the upper limit value of the motor output in the assist force increasing state 12M of the first control state 1M is equal to the second upper limit value 21V. The upper limit value of the motor output in the assist force increasing state 12M is greater than the first upper limit value 11V of the motor 53 in the normal state 11M. The upper limit value of the motor output in the assist force increasing state 22M of the second control state 2M is equal to the third upper limit value 3V. The upper limit value of the motor output in the assist force increasing state 22M is greater than the second upper limit value 21V of the motor 53 in the normal state 21M.

By controlling the control unit 54b, the maximum value of the assist force applied to the human-powered vehicle can be increased when the human-powered vehicle starts traveling in the first control state 1M or the second control state 2M. Increasing the maximum value of the assist force makes it easier for the user to pedal, so the control unit 54 can contribute to a comfortable ride for the human-powered vehicle.

The upper limit value of the output torque of the motor 53 in the third control state 3M is greater than the upper limit value in the first control state 1M and the upper limit value in the second control state 2M. In this embodiment, the third upper limit value 3V in the normal state 31M of the third control state 3M is greater than the first upper limit value 11V in the normal state 11M of the first control state 1M and the second upper limit value 21V in the normal state 21M of the second control state 2M. Because the third upper limit value 3V in the normal state 31M of the third control state 3M is greater than the upper limit values of the output torque in the other normal states, the assist force can be effectively increased in the normal state 31M of the third control state 3M when the human-powered vehicle starts traveling.

Unlike FIG. 9, when the second upper limit value 21V and the third upper limit value 3V are equal, the control unit 54b may update the third upper limit value 3V to a value greater than the second upper limit value 21V when the human-powered vehicle starts traveling in the second control state 2M.

Sixth Embodiment
A control device 54 according to a sixth embodiment will be described. The control device 54 according to the sixth embodiment will be described with reference to Fig. 5 and Fig. 10. The same reference numerals as those in the first to fifth embodiments will be used to designate components common to the first to fifth embodiments, and redundant description will be omitted.

The control unit 54b executes the second control flow shown in FIG. 10. Compared to the first control flow shown in FIG. 5, the second control flow shown in FIG. 10 differs from the first control flow shown in FIG. 5 in that the processing of step S14 differs from the processing of step S4 in the first control flow shown in FIG. 5 in terms of the predetermined cancellation conditions. In the processing of step S14, the predetermined cancellation conditions include a condition related to a reduction in the acceleration of the human-powered vehicle.

The processing of step S14 in the second control flow shown in Figure 10 will now be described. In step S14, the control unit 54b detects the acceleration of the human-powered vehicle based on a signal from the acceleration sensor 65. For example, when the acceleration of the human-powered vehicle is less than a predetermined threshold, the control unit 54b detects that the condition for a decrease in acceleration is met. If the condition for a decrease in acceleration is met, the control unit 54b proceeds to step S5. If the condition for a decrease in acceleration is not met, the control unit 54b repeatedly executes the processing of step S14 until the condition for a decrease in acceleration is met.

By having the control unit 54b execute the second control flow shown in FIG. 10, for example, the acceleration decreases as the vehicle speed of the human-powered vehicle increases, and after the user has made it easier to pedal, the assist force can be reduced below the assist force increasing state 12M or the assist force increasing state 22M. By executing the second control flow, excessive increases in the assist force can be suppressed, and the control unit 54 can contribute to a comfortable ride for the human-powered vehicle.

Seventh Embodiment
A control device 54 according to the seventh embodiment will be described. The control device 54 according to the seventh embodiment will be described with reference to Fig. 5 and Fig. 11. The same reference numerals as those in the first to sixth embodiments will be used to designate components common to the first to sixth embodiments, and redundant description will be omitted.

The control unit 54b executes the third control flow shown in FIG. 11. Compared to the first control flow shown in FIG. 5, the third control flow shown in FIG. 11 differs from the first control flow shown in FIG. 5 in the processing of step S24 in that the processing of step S4 in the first control flow is different from the processing of step S24 in that the predetermined cancellation conditions in the processing of step S4 are different. In the processing of step S24, the predetermined cancellation conditions include a condition related to a reduction in manual power. The conditions related to a reduction in manual power include at least one of a condition related to a reduction in manual torque and a condition related to a reduction in manual power rate. In this embodiment, the conditions related to a reduction in manual power include a condition related to a reduction in manual torque.

The processing of step S24 of the third control flow shown in Figure 11 will be described. In step S24, the control unit 54b detects the manual torque based on a signal from the driving force sensor 63. For example, if the manual torque is less than a predetermined threshold, the control unit 54b detects that the condition for a reduction in manual power is met. If the condition for a reduction in manual power is met, the control unit 54b proceeds to step S5. If the condition for a reduction in manual power is not met, the control unit 54b repeatedly executes the processing of step S14 until the condition for a reduction in manual power is met.

By having the control unit 54b execute the third control flow shown in FIG. 11, for example, after the vehicle speed of the human-powered vehicle increases and it becomes easier for the user to pedal, the assist force can be reduced below that of the assist force increasing state 12M or the assist force increasing state 22M. By executing the third control flow, excessive increases in the assist force can be suppressed, and the control unit 54 can contribute to a comfortable ride for the human-powered vehicle.

Eighth Embodiment
A control device 54 according to an eighth embodiment will be described. The control device 54 according to the eighth embodiment will be described using Fig. 5, Fig. 12, and Fig. 13. The same reference numerals as those in the first to seventh embodiments will be used to designate components common to the first to seventh embodiments, and redundant description will be omitted.

As shown in FIG. 12, in this embodiment, the control unit 54b is configured to apply an assist force by the motor 53 when the vehicle speed of the human-powered vehicle is equal to or less than a first speed 11S, which is specified by specific laws, for example. The assist force shown in FIG. 12 is calculated by multiplying the assist force shown in FIG. 3 by a coefficient determined according to the vehicle speed. When the vehicle speed of the human-powered vehicle is greater than the first speed 11S, the control unit 54b controls the motor 53 so that the assist force becomes 0. The control unit 54b controls the motor 53 so that the assist force decreases as the vehicle speed of the human-powered vehicle approaches the first speed 11S from a second speed 21S, which is smaller than the first speed 11S.

The control unit 54b executes the fourth control flow shown in FIG. 13. Compared to the first control flow shown in FIG. 5, the fourth control flow shown in FIG. 13 differs from the first control flow shown in FIG. 5 in the processing of step S34, which differs from the processing of step S4 in the first control flow shown in FIG. 5. The processing of step S34 differs from the processing of step S4 in the predetermined cancellation conditions. In the processing of step S34, the predetermined cancellation conditions include a predetermined condition related to the vehicle speed.

The processing of step S34 in the fourth control flow shown in Figure 13 will now be described. In step S34, the control unit 54b detects the vehicle speed of the human-powered vehicle based on a signal from the vehicle speed sensor 62. The control unit 54b detects that a predetermined release condition is met based on the vehicle speed of the human-powered vehicle.

In this embodiment, the predetermined release condition is satisfied when the vehicle speed of the human-powered vehicle reaches a predetermined speed, or when the vehicle speed of the human-powered vehicle is lower than the predetermined speed and reaches a value within a predetermined range that is adjusted so that the assist force decreases as the vehicle speed approaches the predetermined speed. In this embodiment, the release condition is satisfied when the vehicle speed of the human-powered vehicle reaches a first speed 11S, but it may also be satisfied when the vehicle speed of the human-powered vehicle reaches a value within the range from second speed 21S to first speed 11S. In step S34 shown in FIG. 13, if the vehicle speed of the human-powered vehicle is greater than first speed 11S, the control unit 54b proceeds to step S5. If the vehicle speed of the human-powered vehicle is equal to or less than first speed 11S, the control unit 54b repeatedly executes the processing of step S34 until the vehicle speed of the human-powered vehicle becomes greater than first speed 11S.

By having the control unit 54b execute the fourth control flow shown in FIG. 13, for example, after the vehicle speed of the human-powered vehicle increases and it becomes easier for the user to pedal, the assist force can be reduced below that of the assist force increasing state 12M or the assist force increasing state 22M. By executing the fourth control flow, excessive increases in the assist force can be suppressed, and the control unit 54 can contribute to a comfortable ride for the human-powered vehicle.

In step S34, the control unit 54b may proceed to step S5 if the vehicle speed of the human-powered vehicle is equal to or greater than the second speed 21S and equal to or less than the first speed 11S. By having the control unit 54b proceed to step S5 if the vehicle speed of the human-powered vehicle is equal to or greater than the second speed 21S and equal to or less than the first speed 11S, the assist force can be gradually reduced toward zero rather than suddenly being set to zero when the vehicle speed reaches the first speed 11S. Because the assist force is gradually reduced when it is reduced, the control device 54 can contribute to a comfortable ride of the human-powered vehicle without causing any discomfort to the user.

Ninth Embodiment
A control device 54 according to the ninth embodiment will be described. The control device 54 according to the ninth embodiment will be described with reference to Fig. 5 and Fig. 14. The same reference numerals as those in the first to eighth embodiments will be used to designate components common to the first to eighth embodiments, and redundant description will be omitted.

The control unit 54b executes the fifth control flow shown in FIG. 14. Compared to the first control flow shown in FIG. 5, the fifth control flow shown in FIG. 14 differs from the first control flow shown in FIG. 5 in the processing of step S44 in that the processing of step S44 differs from the processing of step S4 in that the predetermined cancellation condition is different. In the processing of step S44, the predetermined cancellation condition is satisfied when a predetermined time has elapsed since the human-powered vehicle started traveling.

The processing of step S44 in the fifth control flow shown in Figure 14 will now be described. In step S44, the control unit 54b detects the date and time when the human-powered vehicle started to travel. For example, the control unit 54b detects the date and time when the human-powered vehicle started to travel based on the date and time when a signal was output from the vehicle speed sensor 62 to the control unit 54b and the vehicle speed of the human-powered vehicle. If a predetermined first elapsed time has elapsed since the human-powered vehicle started to travel, the control unit 54b proceeds to step S5. If the first elapsed time has not elapsed since the human-powered vehicle started to travel, the control unit 54b repeatedly executes the processing of step S44 until the first elapsed time has elapsed.

By having the control unit 54b execute the fifth control flow shown in FIG. 14, for example, the assist force can be reduced below the assist force increasing state 12M or the assist force increasing state 22M after the vehicle speed of the human-powered vehicle increases over time and it becomes easier for the user to pedal. By executing the fifth control flow, excessive increases in the assist force can be suppressed, and the control unit 54 can contribute to a comfortable ride for the human-powered vehicle.

(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 is a modified example of each embodiment shown below, or a combination of at least two modified examples that are not mutually contradictory.

For example, the configuration of the drivetrain 1 in each embodiment is an example, and the drivetrain 1 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 thresholds used in the control illustrated in each embodiment are not limited and may be set arbitrarily. The various thresholds may be changed arbitrarily by operating a predetermined operating device, etc.

The configurations exemplified in each embodiment may be combined with each other to the extent that they are not mutually contradictory. For example, the configurations relating to the release conditions of the sixth to ninth embodiments may be combined with each other. When the configurations relating to the release conditions of the sixth to ninth embodiments are combined, the motor 53 may be controlled in normal states 11M and 21M if at least one of the release conditions of the sixth to ninth embodiments is satisfied. For example, when the eighth and ninth embodiments are combined, even if the vehicle speed of the human-powered vehicle is less than the first speed 11S, the control unit 54b may control the motor 53 in normal states 11M and 21M if the first elapsed time has elapsed since the human-powered vehicle started traveling.

The processing contents and processing order of the flowcharts illustrated in each embodiment are merely examples, and the processing contents and processing order can be changed as appropriate within the scope of the present invention.
The front sprocket 10 and the rear sprocket 20 may be replaced with pulleys, and the drive chain 30 may be replaced with a belt. The front sprocket 10 and the rear sprocket 20 may be replaced with bevel gears, and the drive chain 30 may be replaced with a bevel gear and a shaft.

As used herein, the phrase "at least one" means "one or more" of the desired options. As an example, when the number of options is two, the phrase "at least one" means "only one option" or "both of two options." As another example, when the number of options is three or more, the phrase "at least one" means "only one option" or "any combination of two or more options."

1...Drive train, 53...Motor, 54...Control device, 54b...Control unit, 1M, 2M, 3M...Multiple control states, 1M...First control state, 2M...Second control state, 3M...Third control state, 11M, 21M...Normal state, 11V, 21V, 3V...Upper limit of output torque, 12M, 22M...Increased assist force state

Claims (18)

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 a plurality of control states related to adjustment of the assist force in accordance with a driving state of the human-powered vehicle by a human-powered driving force,
each of the two or more control states among the plurality of control states includes a normal state and an increased assist force state in which the assist force is increased compared to that in the normal state;
the assist force is different in each of the normal states in the two or more control states,
the control unit is configured to control the motor in the assist force increasing state in each of the two or more control states and when the human-powered vehicle starts traveling ,
the plurality of control states includes a maximum assist state in which the assist force is the largest among the plurality of control states,
A control device wherein the maximum assist state does not include the increased assist force state in which the assist force increases . The control device according to claim 1 , wherein the one of the two or more control states, the increased assist force state, includes the other of the two or more control states, the normal state, or the maximum assist state . 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 a plurality of control states related to adjustment of the assist force in accordance with a driving state of the human-powered vehicle by a human-powered driving force,
each of the two or more control states among the plurality of control states includes a normal state and an increased assist force state in which the assist force is increased compared to that in the normal state;
the assist force is different in each of the normal states in the two or more control states,
The control unit is configured to be able to set one of the plurality of control states in response to a user's selection, and is configured to automatically select the increased assist state from the increased assist force state and the normal state and control the motor in each of the two or more control states when the human-powered vehicle starts traveling . the control unit is configured to control the motor in response to the manual driving force,
4. The control device according to claim 1, wherein in each of the two or more control states, a maximum assist ratio of the assist force to the manual driving force in the assist force increasing state is greater than the maximum assist ratio in the normal state. the control unit is configured to control the motor in response to the manual driving force,
4. The control device according to claim 1, wherein in each of the two or more control states, a rate of change of the assist force when the human force decreases in the assist force increasing state is smaller than a rate of change of the assist force when the human force decreases in the normal state. A control device according to any one of claims 1 to 3, wherein, in each of the two or more control states, the upper limit value of the motor output torque in the assist force increasing state is greater than the upper limit value in the normal state. The control unit
The control device according to claim 1 , configured to control the motor in the normal state when a predetermined cancellation condition is satisfied in the assist force increasing state. 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 a plurality of control states related to adjustment of the assist force in accordance with a driving state of the human-powered vehicle by a human-powered driving force,
the plurality of control states include a first control state, a second control state in which the assist force is greater than in the first control state, and a third control state in which the assist force is greater than in the second control state,
The control unit
when the first control state is selected and the human-powered vehicle starts traveling, the motor is controlled in either the second control state or the third control state;
a control device configured to control the motor in the third control state when the second control state is selected and the human-powered vehicle starts traveling. the control unit is configured to control the motor in response to the manual driving force,
9. The control device according to claim 8, wherein a maximum assist ratio of the assist force to the manual driving force in the third control state is greater than the maximum assist ratio in the first control state and the maximum assist ratio in the second control state. the control unit is configured to control the motor in response to the manual driving force,
9. The control device according to claim 8, wherein a rate of change of the assist force when the human power decreases in the third control state is smaller than a rate of change of the assist force when the human power decreases in the first control state and a rate of change of the assist force when the human power decreases in the second control state. The control device described in claim 8, wherein the upper limit value of the motor output torque in the third control state is greater than the upper limit value in the first control state and the upper limit value in the second control state. The control unit
when the first control state is selected and the human-powered vehicle starts traveling, if the motor is controlled in either the second control state or the third control state, and a predetermined release condition is satisfied, the motor is controlled in the first control state;
9. The control device according to claim 8, wherein, when the second control state is selected and the human-powered vehicle starts traveling, in a case where the motor is controlled in the third control state, the control device is configured to control the motor in the second control state when a predetermined release condition is satisfied. The control device described in claim 7 or 12, wherein the predetermined release condition includes a condition related to a decrease in acceleration of the human-powered vehicle. The control device described in claim 7 or 12, wherein the predetermined cancellation conditions include a condition related to a reduction in human power. the control unit is configured to, when a speed of the human-powered vehicle is equal to or lower than a predetermined speed, apply the assist force by the motor in accordance with a driving state of the human-powered vehicle by the human-powered driving force;
The control device according to claim 7 or 12, wherein the predetermined release condition includes a condition related to the predetermined speed. The predetermined cancellation conditions are:
When the speed of the human-powered vehicle reaches the predetermined speed, or
16. The control device according to claim 15, wherein the condition is met when the speed of the human-powered vehicle is lower than the predetermined speed and reaches a value within a predetermined range that is adjusted so that the assist force decreases as the speed approaches the predetermined speed. The control device described in claim 7 or 12, wherein the predetermined release condition is satisfied when a predetermined time has elapsed since the human-powered vehicle began traveling. The control device described in claim 1 or 8, wherein the human-powered vehicle includes a single-speed drivetrain.