JP2023058186A - Power-assisted bicycle and drive system thereof, and power-assisted bicycle control method - Google Patents

Abstract

To allow for control at an assist ratio higher than that in a control mode that can be selected by an up-button or a down-button.SOLUTION: A mode selection unit 32 selects a first control mode in accordance with a mode selection operation from a plurality of first control modes that can be selected by a mode selection operation to a user interface device. A motor control unit 31 includes the plurality of first control modes and a control cancel mode, as control modes of an electric motor. Upper limit ratios being upper limits of the assist ratio realized by driving of the electric motor are defined for the plurality of first control modes and the control cancel mode. The upper limit assist ratio of an intensive mode is defined to decrease in accordance with an increase of a vehicle speed in a vehicle speed range higher than a first vehicle speed V1. The upper limit assist ratio is defined for the control cancel mode to be higher than that for the intensive mode in the vehicle speed range higher than the first vehicle speed V1 in comparison at the same vehicle speed.SELECTED DRAWING: Figure 4

Description

TECHNICAL FIELD The present invention relates to a power-assisted bicycle, its drive system, and a control method for a power-assisted bicycle.

An electrically assisted bicycle uses a map that associates vehicle speeds with assist ratios. The assist ratio is the ratio between the torque generated by the stepping action of the pedal (hereinafter referred to as pedal torque) and the torque generated by the electric motor (hereinafter referred to as motor torque). In the control of the electric assist bicycle exemplified in Patent Document 1, the assist ratio is constant up to 15 km, and the assist ratio gradually decreases according to the vehicle speed from 15 km to 24 km (that is, the motor torque decreases as the vehicle speed increases). do).

Japanese Patent Application Laid-Open No. 2001-080569

Patent document 1 discloses a plurality of modes such as mode A and mode B. Switching between these two modes can be realized by a switch operation (one button operation). In any mode, the assist ratio gradually decreases from 15 km to 24 km according to the vehicle speed. Also, in any mode, when the vehicle speed reaches 24 km, the assist ratio becomes 0, and the electric motor stops assisting. Such restrictions on electric motor assistance are not necessarily user-friendly.

A drive system for a power-assisted bicycle proposed in the present disclosure includes a user interface device having at least one input unit for receiving a mode selection operation by a driver, and a plurality of first control modes selectable by the mode selection operation. , a mode selection unit that selects a first control mode according to the mode selection operation, and a motor control unit that controls the electric motor in the selected first control mode based on the vehicle speed detected by the sensor. are doing. The motor control section includes the plurality of first control modes and a second control mode as control modes of the electric motor, and each of the plurality of first control modes and the second control mode includes: , an upper limit assist ratio, which is the upper limit of the assist ratio realized by driving the electric motor, is defined. One of the plurality of first control modes defines the highest upper limit assist ratio among the plurality of first control modes, and the one upper limit assist ratio of the plurality of first control modes is , to decrease as the vehicle speed increases in a vehicle speed range higher than the first vehicle speed. The second control mode defines an upper limit assist ratio that is higher than the one of the plurality of first control modes when compared at the same vehicle speed in a vehicle speed range higher than the first vehicle speed. According to this drive system, a higher assist ratio can be realized by using the second control mode than the plurality of first control modes that can be selected by the mode selection operation.

(1) In the first example of the drive system, the mode selector permits the selection of the second control mode on condition that the driver is successfully authenticated. According to this drive system, use of the second control mode can be permitted only for drivers who have been successfully authenticated.

(2) In the second example of the drive system, the mode selector allows selection of the second control mode when the user's pedaling ability satisfies a predetermined condition. According to this drive system, use of the second control mode can be permitted only for a driver who has pedaling ability that satisfies a predetermined condition.

(3) In the third example of the drive system, the mode selector allows selection of the second control mode when the driving environment satisfies a predetermined condition. According to this drive system, the use of the second control mode can be permitted only in a driving environment that satisfies a predetermined condition.

(4) In the drive system of (1) to (3), in the one of the plurality of first control modes, first assist ratio defining information that associates a vehicle speed and an assist ratio is used, and the second control is performed. In the mode, the second assist ratio defining information that associates the vehicle speed and the assist ratio may be used. The first assist ratio defining information defines the first assist ratio as the upper limit assist ratio for a vehicle speed range lower than the first vehicle speed, and the upper limit that decreases as the vehicle speed increases for a vehicle speed range higher than the first vehicle speed. An assist ratio may be defined. The second assist ratio defining information defines an upper limit assist ratio that is higher than the upper limit assist ratio defined by the first assist ratio defining information when compared at the same vehicle speed for a range of vehicle speeds higher than the first vehicle speed. You can

(5) In the drive system of (1) to (3), the upper limit assist ratio defined in the one of the plurality of first control modes is the first assist ratio in a vehicle speed range lower than the first vehicle speed. and the upper limit assist ratio defined in the second control mode may be the first assist ratio in at least part of a vehicle speed range higher than the first vehicle speed.

(6) In the drive system of (1) to (3), the upper limit assist ratio defined for the second control mode is higher than the second vehicle speed, which is higher than the first vehicle speed. may decrease accordingly.

(7) In the drive system of (1), the user interface device may have a plurality of input units, including the at least one input unit, for accepting driver's operations. The mode selection unit may determine that authentication is successful when a predetermined authentication operation is performed on the plurality of input units, and allow selection of the second control mode. According to this, the authentication operation can be performed without using a dedicated device or parts.

(8) The drive system of (7) may further include an authentication operation setting unit that sets the predetermined authentication operation based on the driver's operation on the plurality of input units. According to this, the user can change the authentication operation as necessary.

(9) In the drive system of (7), the at least one input section includes a button for the driver to switch between the plurality of first control modes. According to this, it is possible to suppress an increase in the number of parts of the user interface device.

(10) In the drive system of (1), the mode selection unit selects the second control mode when a predetermined selection stop operation is performed on the plurality of input units while the second control mode is selected. 2 control mode selection may be stopped. According to this, the driver can easily return to any one of the plurality of first control modes.

(11) The drive system of (1) may further have a connector for connecting an authentication device or an authentication component. The mode selection unit may determine that the authentication is successful when the authentication device or the authentication component is connected to the connection unit, and allow selection of the second control mode. Here, the authentication device may be, for example, a mobile terminal owned by the owner of the bicycle, and the authentication component may be, for example, a mechanical key or an electronic key.

(12) In the drive system of (2), the mode selection unit selects the force acting on the pedal, the number of rotations of the pedal, the left-right balance, and the response speed to the load as the pedaling ability of the user. may be used to determine whether to permit selection of the second control mode.

(13) In the drive system of (2), the upper limit assist ratio defined for the second control mode decreases as the vehicle speed increases in a vehicle speed range higher than the second vehicle speed higher than the first vehicle speed. However, the second vehicle speed may change according to the pedaling ability of the driver. According to this, it is possible to provide a more comfortable running for a driver who has a high pedaling ability.

(14) In the drive system of (3), the running environment is at least one of road inclination, road surface condition, load acting on the bicycle, brightness around the bicycle, weather, and congestion. can be

(15) The power-assisted bicycle proposed in the present disclosure has the drive system of (1), (2), or (3).

A control method for a power-assisted bicycle proposed in the present disclosure is a control method for a power-assisted bicycle having a user interface device having at least one input unit for receiving a mode selection operation by a driver. This control method includes a mode selection step of selecting a first control mode according to the mode selection operation from among a plurality of first control modes selectable by the mode selection operation, each having a different assist ratio; and a motor control step of controlling the electric motor in the selected first control mode based on the detected vehicle speed. The motor control step includes the plurality of first control modes and a second control mode as control modes of the electric motor. An upper limit assist ratio, which is the upper limit of the assist ratio realized by driving the electric motor, is defined for each of the plurality of first control modes and the second control mode. One of the plurality of first control modes defines the highest upper limit assist ratio among the plurality of first control modes, and the one upper limit assist ratio of the plurality of first control modes is , to decrease as the vehicle speed increases in a vehicle speed range higher than the first vehicle speed. The second control mode defines an upper limit assist ratio that is higher than the one of the plurality of first control modes when compared at the same vehicle speed in a vehicle speed range higher than the first vehicle speed. According to this control method, a higher assist ratio can be realized by using the second control mode than the plurality of first control modes that can be selected by the mode selection operation.

(16) In the first example of the control method, the mode selection step determines whether or not selection of the second control mode is permitted on condition that the driver's authentication is successful. According to this control method, use of the second control mode can be permitted only for drivers who have been successfully authenticated.

(17) In the second example of the control method, the mode selection step allows selection of the second control mode when the user's pedaling ability satisfies a predetermined condition. According to this control method, use of the second control mode can be permitted only for a driver who has a pedaling ability that satisfies a predetermined condition.

(18) In the third example of the control method, the mode selection step allows selection of the second control mode when the driving environment satisfies a predetermined condition. According to this control method, the use of the second control mode can be permitted only in a driving environment that satisfies a predetermined condition.

1 is a side view showing an example of a vehicle proposed in the present disclosure; FIG. 1 is a block diagram showing the configuration of a power-assisted bicycle according to a first example; FIG. 1 is a diagram illustrating an example of a user interface device; FIG. 3 is a block diagram showing functions of a control device; FIG. FIG. 5 is a diagram showing an example of upper limit assist ratios defined by assist ratio defining information referred to in strong mode, medium mode, and weak mode (a plurality of first control modes); It is a figure which shows the example of the upper limit assistance ratio prescribed|regulated by the assistance ratio regulation information referred by restriction release mode (2nd control mode). FIG. 9 is a diagram showing another example of the upper limit assist ratio defined by assist ratio defining information referred to in the limit release mode; FIG. 11 is a diagram showing still another example of the upper limit assist ratio defined by assist ratio defining information referred to in the limit release mode; FIG. 11 is a diagram showing still another example of the upper limit assist ratio defined by assist ratio defining information referred to in the limit release mode; FIG. 5 is a flow chart showing an example of processing executed by a mode selection unit; FIG. 11 is a diagram showing still another example of the upper limit assist ratio defined by assist ratio defining information referred to in the limit release mode; This figure shows the upper limit assist ratio defined by three pieces of assist ratio defining information that can be referred to in the limit release mode. FIG. 9 is a flow chart showing an example of processing for using the assist ratio defining information illustrated in FIG. 8; FIG. 4 is a block diagram showing the configuration of a power-assisted bicycle according to a second example; 11 is a block diagram showing functions of a control device in the power-assisted bicycle shown in FIG. 10; FIG. FIG. 4 is a diagram showing a map for calculating pedaling ability from cadence and pedaling force; FIG. 10 is a diagram showing an example of an upper limit assist ratio defined by assist ratio defining information referred to in the control device according to the second example; FIG. 11 is a block diagram showing the configuration of a power-assisted bicycle according to a third example; 15 is a block diagram showing functions of a control device in the power-assisted bicycle shown in FIG. 14; FIG.

An embodiment of the present invention will be described below. FIG. 1 is a side view of a power-assisted bicycle 100 that is an example of an embodiment of the invention. FIG. 2 is a block diagram showing the configuration of the electrically assisted bicycle 100. As shown in FIG. In FIG. 2, thick solid lines represent power transmission, and thin solid lines represent electrical signals and electric currents. Below, the power-assisted bicycle 100 is simply referred to as a bicycle.

The bicycle 100 has a drive system for assisting the pedaling action of the rider. The drive system includes electric components such as an electric motor 14 (to be described later), a control device 30 , a motor drive device 13 , and a UI device 50 .

[overall structure]
As shown in FIG. 1, bicycle 100 has crankshaft 7 . Pedals 6 are attached to the right and left ends of the crankshaft 7 via crank arms. The crankshaft 7 is positioned below the lower end of the seat tube 1b. A saddle 2 is attached to the upper end of the seat tube 1b. A handle stem 8, a handle 9 connected to the upper portion of the handle stem 8, a front fork 8a connected to the lower portion of the handle stem 8, and a lower end of the front fork 8a are supported at the front portion of the bicycle 100. A front wheel 3 is provided. A handle stem 8 is supported by a head pipe 1 a provided at the front end of the frame 1 . The shape of the frame 1 is not limited to the example shown in FIG. 1, and may be changed as appropriate.

As shown in FIG. 1, bicycle 100 has drive unit 20 . The drive unit 20 includes an electric motor 14 (see FIG. 2) that outputs an assist force (assist torque) for assisting the driving of the rear wheels 4 (stepping action of the pedal 6) by the driver, and a speed reducer 21 (see FIG. 2). have. The electric motor 14 is driven by power supplied from a battery 15 (see FIG. 1). The battery 15 is attached, for example, to the rear side of the seat tube 1b. The drive unit 20 is arranged behind the crankshaft 7 . The positions of the electric motor 14 and the battery 15 are not limited to the example of the bicycle 100, and may be changed as appropriate.

As shown in FIG. 2 , the force applied to the crankshaft 7 through the pedal 6 is transmitted to the resultant force transmission mechanism 22 . Further, power (assist force) output from the electric motor 14 is transmitted to the resultant force transmission mechanism 22 through the reduction gear 21 . The resultant force transmission mechanism 22 includes a shaft, a rotating member (a gear, a sprocket, etc.) provided on the shaft, a power transmission member (eg, a chain 5, a shaft, a belt, etc.), and the like. Both the force applied to the crankshaft 7 and the power output from the electric motor 14 are input to the resultant force transmission mechanism 22 . The power synthesized by the resultant force transmission mechanism 22 is transmitted to the rear wheels 4 . The power synthesized by the resultant force transmission mechanism 22 may be input to the rear wheels 4 via a transmission mechanism capable of changing the gear ratio by operation of the driver.

As shown in FIG. 2, the drive system of the bicycle 100 has a pedaling force sensor 41 for detecting the pedaling force applied to the pedals 6 by the rider. The pedaling force sensor 41 is a torque sensor that outputs a signal corresponding to torque generated in the crankshaft 7 . The pedaling force sensor 41 is, for example, a magnetostrictive sensor provided on the crankshaft 7, but may be another type of sensor. Hereinafter, the torque of the crankshaft 7 will be referred to as "pedal force".

As shown in FIG. 2, the drive system of the bicycle 100 has a vehicle speed sensor 42 that outputs a signal corresponding to vehicle speed. The vehicle speed sensor 42 is provided, for example, in the front wheels 3 and outputs a signal according to the rotation of the front wheels 3 . The vehicle speed sensor 42 may be provided on the rear wheel 4 .

[Control device]
As shown in FIG. 2 , the drive system of bicycle 100 has a control device 30 that controls electric motor 14 . The control device 30 includes a storage device 30a that holds programs and maps for controlling the electric motor 14 . The storage device 30a has a Random Access Memory (RAM), a ROM (Read Only Memory), and the like. The controller 30 has one or more microprocessors that execute the program.

The control device 30 controls the electric motor 14 based on the pedaling force detected by the pedaling force sensor 41 and the vehicle speed detected by the vehicle speed sensor 42 . The storage device 30a stores in advance a map that defines the assist ratio according to the vehicle speed, conditions for changing the control mode of the electric motor 14, and the like.

The assist ratio is defined as the torque applied to the rear wheels 4 by the driver's stepping on the pedals 6 (referred to herein as pedal torque) and the torque transmitted from the electric motor 14 to the rear wheels 4 (referred to herein as motor torque). ). When the pedal torque is Tp and the motor torque is Tm, the assist ratio is expressed as "Tm/Tp". The assist ratio is, for example, a value greater than 0 and 2 or less.

The control device 30 has a plurality of control modes with mutually different assist ratios as control modes for the electric motor 14 . The controller 30 may have, for example, a strong mode, a medium mode, and a weak mode. The upper assist ratio specified for the strong mode is higher than the upper assist ratio specified for the other two control modes. Also, the upper limit assist ratio specified for the medium mode is higher than the upper limit assist ratio specified for the weak mode. These three control modes can be selected by an arbitrary driver's mode selection operation on the UI device 50 (specifically, turning on the up button 52a and the down button 52b). The number of control modes selectable by an arbitrary driver is not limited to three, and may be two or more than three.

As will be described later, the control device 30 has a limit release mode in addition to the three control modes described above. The limit release mode is a control mode that achieves a higher assist ratio than the above-described three control modes in a predetermined vehicle speed range. Restriction release mode is permitted only when the driver satisfies predetermined conditions.

The storage device 30a stores information (assist ratio defining information) that defines the assist ratio according to the vehicle speed for each control mode. As the assist ratio defining information, for example, one or a plurality of maps that associate vehicle speeds and assist ratios are used. The control mode and assist ratio defining information of control device 30 will also be described in detail later.

[UI device]
As shown in FIG. 2, the bicycle 100 has a user interface device (UI device) 50. As shown in FIG. The UI device 50 has, for example, an input button and an indicator. FIG. 3 is a diagram showing an example of the UI device 50. As shown in FIG. As shown in FIG. 3, the UI device 50 may include an up button 52a, a down button 52b, a display selection button 52c, a light control button 52d, and a power button 52e as examples of input buttons. The input buttons 52a to 52e input signals (on/off signals) to the control device 30 in accordance with their operations.

The up button 52a and the down button 52b are input buttons for receiving a mode selection operation by the driver. The up button 52a is a button for instructing a shift to a mode with a high assist ratio. Specifically, the up button 52a is a button for instructing a shift from the weak mode to the medium mode and from the medium mode to the strong mode. The down button 52b is a button for instructing transition to a mode with a low assist ratio. Specifically, the down button 52b is a button for instructing a shift from the strong mode to the medium mode and from the medium mode to the weak mode.

The input button that accepts the mode selection operation is not limited to the example shown in FIG. For example, the UI device 50 may have a plurality of input buttons respectively corresponding to a plurality of control modes (strong mode, medium mode, weak mode) selectable by any driver.

Bicycle 100 has a headlight (not shown). The light control button 52d is a button for turning on and off the headlamp. The power button 52e is a button for turning on/off the power supply to the control device 30 and the motor driving device 13 .

Further, the UI device 50 may have mode indicators 53a to 53c, a limit release indicator 53d, a numeric indicator 53e, and a remaining battery indicator 53f as indicators. Mode indicators 53a to 53c are indicators for indicating the currently selected control mode. The three mode indicators 53a-53c respectively correspond to the three control modes described above, namely strong mode, medium mode, and weak mode.

As described above, the control device 30 has the restriction release mode as the control mode for the electric motor 14 . The restriction release indicator 53d is an indicator that indicates that the restriction release mode is selected. The restriction release indicator 53d may, for example, light up or blink when the restriction release mode is selected.

The remaining battery level indicator 53f displays an icon image corresponding to the remaining amount of the battery 15. FIG. The numerical indicator 53e is an indicator for displaying numerical information such as the current vehicle speed and remaining battery capacity. The display selection button 52c is a button for selecting information (for example, vehicle speed and remaining battery capacity) displayed on the numerical indicator 53e.

The indicators 53a to 53d and 53f may be composed of LEDs (Light Emitting Diodes). The numeric indicator 53e may be composed of a liquid crystal display device, an organic EL display device, or the like. Buttons 52a-52e may comprise switches mounted on a circuit board. Alternatively, as the UI device 50, a display device attached with a touch sensor that detects the position of the driver's finger may be used.

[Control details]
FIG. 4 is a block diagram showing the functions of the control device 30. As shown in FIG. The control device 30 has a motor control section 31 , a mode selection section 32 and a mode guidance section 33 . These are realized by executing a program stored in the storage device 30a by the microprocessor that constitutes the control device 30. FIG.

[Motor control part]
As described above, the control device 30 has a plurality of control modes (strong mode, medium mode, weak mode) that can be selected by an arbitrary driver as control modes for the electric motor 14 . The number of control modes may be less than three or more than three. A plurality of pieces of assist ratio defining information may be stored in the storage device 30a corresponding to a plurality of control modes.

Each assist ratio defining information defines an assist ratio corresponding to the vehicle speed. Each piece of assist ratio defining information may define the assist ratio corresponding to not only the vehicle speed but also the pedaling force. For example, the assist ratio may be defined to decrease according to vehicle speed in a vehicle speed range higher than a certain vehicle speed. Further, when the pedaling force is small, the assist ratio may be defined to decrease as the pedaling force decreases.

A map may be used as the assist ratio defining information. For example, the assist ratio defining information may be a map that defines the assist ratio in correspondence with vehicle speed and pedaling force. In this case, the map that defines the assist ratio may be composed of a plurality of maps. For example, each assist ratio defining information is configured by a first map that associates the basic assist ratio with the pedaling force, and a second map that associates the coefficient by which the basic assist ratio obtained from the first map is multiplied with the vehicle speed. good too. In this case, the assist ratio can be expressed by the following formula.
Assist ratio=basic assist ratio×coefficient Alternatively, the assist ratio may be associated only with the vehicle speed. In this case, the vehicle speed and the assist ratio may be directly associated on the map. Also, the assist ratio does not necessarily have to be defined by the map. For example, the storage device 30a may store an arithmetic expression that defines the assist ratio according to the vehicle speed.

The motor control unit 31 refers to the assist ratio regulation information corresponding to the selected control mode and calculates the assist ratio according to the vehicle speed detected by the vehicle speed sensor 42 . Further, in a bicycle in which the assist ratio is specified according to the vehicle speed and the pedaling force, the motor control unit 31 refers to the assist ratio specifying information corresponding to the selected control mode, and detects the pedaling force detected by the pedaling force sensor 41. and the vehicle speed detected by the vehicle speed sensor 42, the assist ratio is calculated. Then, the motor control unit 31 calculates an assist force according to the pedal force detected based on the output of the pedal force sensor 41 and the assist ratio, and outputs a command value according to the assist force to the motor drive device 13 . The motor drive device 13 receives power from the battery 15 and supplies the electric motor 14 with a current corresponding to the command value.

[Assist ratio specified by assist ratio specifying information]
FIG. 5 is a diagram for explaining an example of the assist ratio defined by the assist ratio defining information. In this figure, the horizontal axis is the vehicle speed, and the vertical axis is the assist ratio. This figure shows an example of the upper limit of the assist ratio (upper limit assist ratio) realized by the control device 30 at each vehicle speed. In this diagram, lines E1 (E11 and E12), E2, and E3 respectively show examples of the relationship between vehicle speed and upper limit assist ratio in three control modes (strong mode, medium mode, and weak mode).

The motor control unit 31 calculates the upper limit assist ratio illustrated in FIG. 5 or an assist ratio smaller than the upper limit assist ratio, and outputs a current command value according to the calculated assist ratio to the motor drive device 13 . For example, when the pedaling force is greater than the threshold, the motor control unit 31 outputs a current command value corresponding to the upper limit assist ratio illustrated in FIG. 5 to the motor drive device 13 . On the other hand, when the pedaling force is smaller than the threshold, the motor control section 31 may output to the motor drive device 13 a current command value corresponding to an assist ratio smaller than the upper limit assist ratio illustrated in FIG. In this case, the calculated assist ratio may decrease as the pedal effort decreases.

As indicated by the solid line E11, the strong mode assist ratio defining information defines a constant upper limit assist ratio R1 in the vehicle speed range from 0 to vehicle speed V1. Further, as indicated by the solid line E12 in FIG. 5, the assist ratio defining information for the strong mode decreases as the vehicle speed increases in a vehicle speed range higher than the vehicle speed V1. stipulates. As indicated by the solid lines E2 and E3, the assist ratio stipulating information for the middle mode and the weak mode stipulates constant upper limit assist ratios R2 and R3 in the vehicle speed range from 0 to vehicle speed V1, and in the vehicle speed range higher than the vehicle speed V1. , decreases as the vehicle speed increases, and is set to 0 at vehicle speed V2.

As shown in this figure, when comparing the upper limit assist ratios of the three modes at the same vehicle speed, strong mode>medium mode>weak mode. The high mode upper limit assist ratio R1 defined for a vehicle speed range lower than the vehicle speed V1 can be selected by a mode selection operation on the UI device 50 (specifically, an ON operation of the up button 52a and an ON operation of the down button 52b). It is the largest among the upper limit assist ratios set for a plurality of control modes. In addition, even in a vehicle speed range higher than vehicle speed V1, the upper limit assist ratio of the strong mode (solid oblique line E12) is the largest among the upper limit assist ratios of the three control modes when compared at the same vehicle speed.

The assist ratio defining information described in FIG. 5 is merely an example, and may be changed as appropriate. For example, the vehicle speed at which the middle mode and/or the low mode upper limit assist ratio starts to decrease may be different from the vehicle speed V1 at which the high mode upper limit assist ratio starts to decrease. For example, the vehicle speed at which the lowering of the upper limit assist ratio in the middle mode and/or the weak mode starts may be higher than the vehicle speed V1. Even in this case, the upper limit assist ratio of the medium mode and/or the weak mode does not exceed the upper limit assist ratio of the strong mode (the oblique solid line E12).

Bicycle 100 defines a map for each of a plurality of control modes. However, multiple control modes may use a common map. For example, the value obtained from the map may be used as the assist ratio in the strong mode, while the value obtained by correcting the value obtained from the map may be used as the assist ratio in the medium mode and the weak mode. . For correction, for example, the value obtained from the map may be multiplied by a correction coefficient K (K<1). In this case, the vehicle speed and the assist ratio are associated with each other by the correction coefficient K and the arithmetic expression.

[Mode selection part]
The mode selection unit 32 selects one of the three control modes based on the driver's mode selection operation on the UI device 50 . In the example shown in FIG. 3, the UI device 50 has an up button 52a and a down button 52b. For example, the mode selection unit 32 selects the medium mode when the down button 52b is pressed while the strong mode is selected, and selects the weak mode when the down button 52b is pressed while the medium mode is selected. do. Further, the mode selection unit 32 selects the medium mode when the up button 52a is pressed while the weak mode is selected, and selects the strong mode when the up button 52a is pressed while the medium mode is selected. do.

[Limit release mode]
The control device 30 has a restriction release mode as its control mode. The storage device 30a may store assist ratio defining information corresponding to the restriction release mode. FIG. 6A is a diagram showing an example of the upper limit assist ratio defined by the assist ratio defining information in the limit cancellation mode. In FIG. 6A, the solid line E4 is the line representing the upper limit assist ratio in the restriction cancellation mode, and the dashed lines E1, E2, and E3 are the lines representing the upper limit assist ratios of the strong mode, medium mode, and weak mode, respectively.

In the limit cancellation mode shown in FIG. 6A, a higher upper limit assist ratio than the upper limit assist ratio of the strong mode (solid line E12, see FIG. 5) is defined for the vehicle speed range higher than the vehicle speed V1 when compared at the same vehicle speed. More specifically, in a range of vehicle speeds higher than vehicle speed V3, which is higher than vehicle speed V1, the upper limit assist ratio is defined to decrease as the vehicle speed increases (solid line E42). As in the strong mode, the upper limit assist ratio is 0 at vehicle speed V2. In the vehicle speed range lower than the vehicle speed V3, the same upper limit assist ratio as the upper limit assist ratio R1 of the strong mode is specified (solid line E41).

6B to 6D are diagrams for explaining other examples of assist ratio defining information referred to in the restriction release mode. These figures show the upper limit of the assist ratio that can be obtained at each vehicle speed (that is, the upper limit assist ratio) in the limit cancellation mode.

As shown in FIG. 6B, a constant upper limit assist ratio may be defined up to the upper limit of the vehicle speed (vehicle speed V2) at which assist by the electric motor 14 is performed, regardless of the vehicle speed. More specifically, the high mode upper limit assist ratio R1 may be defined in the vehicle speed range from 0 to V2.

Further, in the example shown in FIG. 6C, the upper limit assist ratio R1 for the high mode is defined for a vehicle speed range lower than the vehicle speed V1. An upper limit assist ratio (solid line E42) is defined that decreases as the vehicle speed increases in a vehicle speed range higher than the vehicle speed V1. That is, the lowering of the upper limit assist ratio starts from the vehicle speed V1, as in the strong mode assist ratio defining information. This upper limit assist ratio (solid line E42) is higher than the upper limit assist ratio (broken line E12) of the strong mode defined in the same vehicle speed range. An upper limit assist ratio R4 larger than 0 is also defined for the upper limit of the vehicle speed (vehicle speed V2) at which the electric motor 14 assists, and 0 is defined as the upper limit assist ratio for a range of vehicle speeds higher than the vehicle speed V2. there is Unlike the example shown in FIG. 6C, an upper limit assist ratio greater than 0 may also be defined for a vehicle speed range higher than the vehicle speed V2.

Further, in the example shown in FIG. 6D, the upper limit assist ratio R1 for the strong mode is defined for a vehicle speed range lower than the vehicle speed V1. An upper limit assist ratio (solid line E42) is defined that decreases as the vehicle speed increases in a vehicle speed range higher than the vehicle speed V1. That is, the lowering of the upper limit assist ratio starts from the vehicle speed V1, as in the strong mode assist ratio defining information. Also, in a range of vehicle speeds higher than vehicle speed V4, an upper limit assist ratio (solid line E43) is defined that greatly decreases as the vehicle speed increases. The slope of the solid line E43 is greater than the slope of the solid line E42. That is, the rate of decrease in the upper limit assist ratio specified in the vehicle speed range higher than vehicle speed V4 is greater than the rate of decrease in the upper limit assist ratio specified in the vehicle speed range from vehicle speeds V1 to V4.

Note that the storage device 30a may not store the map for the restriction release mode. In this case, the motor control unit 31 may use a map of control modes that are allowed for any driver to achieve the assist ratio described with reference to FIGS. 6A to 6D. Also, no map need be used to achieve the assist ratios described with reference to FIG. 6B. The motor control section 31 may use the fixed value R1 as the assist ratio.

[Authentication part]
As shown in FIG. 4, the mode selection unit 32 has an authentication unit 32b (see FIG. 4) that performs authentication processing for the driver. The authentication unit 32b determines whether or not the driver has been successfully authenticated. The mode selection unit 32 permits the selection of the restriction release mode when the authentication is successful. When the limit release mode is selected, the motor control unit 31 refers to the assist ratio regulation information of the limit release mode (solid line E4 in FIGS. 6A to 6D), and determines the assist ratio corresponding to the current vehicle speed (and pedal force). Calculate

Processing by the authentication unit 32b is performed, for example, as follows. Bicycle 100 has UI device 50 . The UI device 50 has a plurality of input buttons (input units) 52a to 52e. The authentication unit 32b determines that the authentication is successful (that is, determines that the driver is appropriate) when a predetermined authentication operation is performed on the plurality of input buttons 52a to 52e, and allows selection of the restriction release mode. do. That is, when the driver inputs a predetermined password using the input buttons 52a to 52e, the authenticating section 32b determines that the authentication has succeeded.

The authentication operation includes, for example, pressing a plurality of input buttons in a predetermined order. That is, when a plurality of predetermined input buttons 52a to 52e are turned on (pressed) in a predetermined order, the authentication unit 32b determines that the authentication has succeeded. The authentication operation may include simultaneous pressing of a plurality of input buttons and/or long pressing of any input button (for example, pressing for several seconds or longer).

In the example shown in FIG. 3, the UI device 50 has five input buttons 52a-52e. The authentication unit 32b may use only some of the input buttons 52a to 52e that the UI device 50 has. For example, the authentication unit 32b may use only the up button 52a and the down button 52b in the authentication process.

According to such processing of the authentication unit 32b, use of the restriction cancellation mode that achieves an assist ratio exceeding that of the strong mode can be permitted only for the driver who knows the authentication operation. For example, only a driver who is used to driving the bicycle 100 (for example, the owner of the bicycle 100) is allowed to ride in the restriction release mode, and a driver who rents the bicycle 100 is allowed to ride in the restriction release mode. can be regulated.

Further, in the example described here, the input button used for the authentication operation and the input button for the driver to input instructions to the control device 30 are also used. For example, input buttons (specifically, the up button 52a and the down button 52b) for instructing a change of a plurality of control modes (strong mode, medium mode, and weak mode) are used for the authentication operation. This makes it possible to avoid an increase in the number of parts for accepting the authentication operation.

[Change authentication operation]
As shown in FIG. 4, the mode selection section 32 may have an authentication operation setting section 32c. The authentication operation setting unit 32c accepts password setting by the driver. That is, the authentication operation setting unit 32c receives operation inputs from the driver (user) with respect to the plurality of input buttons 52a to 52e, sets authentication operations that the authentication unit 32b determines as appropriate based on the operation inputs, and sets the authentication operations. The operation is recorded in the storage device 30a. The authentication unit 32b determines that the authentication is successful when the authentication operation recorded in the storage device 30a is performed on the input buttons 52a to 52e.

Note that the mode selection unit 32 may not have the authentication operation setting unit 32c. In this case, the authentication unit 32b may determine, for example, whether or not the driver has performed an authentication operation set when the control device 30 was manufactured.

[Stop Restriction Release Mode]
The mode selector 32 may stop selecting the limit release mode when a predetermined selection stop operation is performed on the input buttons 52a to 52e while the limit release mode is selected. Then, the mode selection unit 32 may select any of the control modes (strong mode, medium mode, and weak mode) that are allowed for any driver.

The selection deactivation operation may be simpler than the authentication operation. For example, the number of times the input button is pressed in the selection stop operation may be less than the number of times the input button is pressed in the authentication operation. As described above, examples of the authentication operation include pressing a plurality of input buttons in a predetermined order, pressing a plurality of input buttons at the same time, pressing and holding any of the input buttons (for example, pressing for several seconds or longer). operation), etc. On the other hand, the selection stop operation may be an operation on any one input button.

The UI device 50 has a power button 52e. When the control device 30 is turned off by operating the power button 52e while the restriction release mode is selected, the mode selection unit 32 may stop selecting the restriction release mode. For example, when the restriction release mode is selected, information (flag) indicating that fact may be recorded in the storage device 30a. When the control device 30 is turned off, the mode selector 32 may erase this information from the storage device 30a.

[Authentication using authentication components or authentication devices]
The processing of the authentication unit 32b is not limited to the example using the UI device 50 described above. The bicycle 100 may have a connection section to which an authentication component or authentication device is connected. The authentication unit 32b may determine that authentication has succeeded when such an authentication component or authentication device is connected to the connection unit, and allow selection of the restriction release mode. The authentication component is, for example, a mechanical key or an electronic key, and the authentication device is, for example, a mobile terminal (eg, smart phone) owned by the driver (user).

If the authentication component is a mechanical key, the bicycle 100 may have a key cylinder 43 (connection) as shown in FIG. The key cylinder 43 has a switch for detecting a key operation (for example, key rotation) and inputting a signal indicating it to the control device 30 . When this signal is input from the key cylinder 43, the authentication unit 32b may determine that the authentication has succeeded, and allow selection of the restriction release mode.

If the authentication device is a mobile terminal, the bicycle 100 may have a communication module 44 (connection section) instead of the key cylinder 43 as shown in FIG. A communication module 44 is a communication module for two-way communication between the mobile terminal and the control device 30 . The communication module 44 enables communication between the mobile terminal and the control device 30 according to standards such as Wi-Fi (registered trademark) and Bluetooth (registered trademark). The authentication unit 32b may request authentication information from the mobile terminal. If the authentication information received from the mobile terminal matches the authentication information recorded in the storage device 30a, the authentication unit 32b determines that the authentication has succeeded, and allows selection of the restriction release mode. good too.

When such authentication components and authentication device are used by the authentication unit 32b, the mode selection unit 32 selects the restriction release mode when these authentication components and authentication device are removed (when the connection is cut). You can stop choosing For example, when the key is removed from the key cylinder 43, the mode selector 32 may stop selecting the restriction release mode. When the mobile terminal is used as an authentication device, the mode selector 32 may request the mobile terminal to respond at predetermined time intervals. Then, when there is no response from the mobile terminal, the mode selection unit 32 may determine that the connection between the control device 30 and the mobile terminal has been broken, and stop selecting the restriction release mode. Then, when the selection of the restriction release mode is stopped, the mode selection unit 32 may select any one of the control modes (strong mode, medium mode, and weak mode) allowed for any driver.

[Start Restriction Release Mode]
When the authentication by the authentication unit 32b is successful, the mode selection unit 32 selects the limit release mode, and the motor control unit 31 starts the limit release mode that realizes the upper limit assist ratio illustrated in FIGS. 6A to 6D. you can

Alternatively, the mode selection unit 32 may select the restriction release mode when authentication by the authentication unit 32b is successful and a predetermined condition is satisfied. For example, the mode selection unit 32 may select the restriction release mode when authentication by the authentication unit 32b is successful and a predetermined operation is performed on the UI device 50 . For example, the mode selection unit 32 may select the restriction release mode when authentication by the authentication unit 32b is successful and the up button 52a is operated once or multiple times. Then, the motor control section 31 may start controlling the electric motor 14 based on the assist ratio defining information (FIGS. 6A to 6D) in the restriction cancellation mode. According to this, the electric motor 14 is controlled in the limit release mode in a situation where the driver clearly indicates the need for assistance in the limit release mode.

FIG. 7 is a flowchart showing an example of such processing of the mode selection unit 32. As shown in FIG. First, the driver performs the above-described authentication operation (input button operation, key connection, or authentication using a mobile terminal). authentication success flag) is stored in the storage device 30a.

After that, the mode selection unit 32 determines whether or not a predetermined operation (hereinafter referred to as a restriction release operation) has been performed (S101). Here, one example of the restriction release operation is one or more operations of the up button 52a in a state where the strong mode is selected. When the restriction release operation is performed, the mode selection unit 32 determines whether or not an authentication success flag is stored in the storage device 30a (S102). When the authentication success flag is stored in the storage device 30a in S102, the mode selection unit 32 selects the restriction release mode (S103). As a result, the motor control unit 31 starts controlling the electric motor 14 based on the assist ratio defining information in the restriction release mode. On the other hand, in S102, if the authentication success flag is not stored in the storage device 30a, the mode selection unit 32 ends the process while maintaining the current control mode (strong mode, medium mode, or weak mode).

Note that the restriction release operation does not have to be an operation on the up button 52a. The UI device 50 may be provided with a dedicated button for the restriction release operation.

The mode selection unit 32 may shift to the strong mode when, for example, the down button 52b is operated while the restriction release mode is selected. The operation of this down button 52b corresponds to the selection stop operation described above.

As still another example, when the authentication by the authentication unit 32b is successful, the restriction release operation is performed on the UI device 50, and the conditions regarding the driver's pedaling ability are satisfied, the mode selection unit 32 may select an unrestricted mode. The pedaling ability may be evaluated, for example, based on the output of the pedaling force sensor 41 or the cadence (rotational speed of the crankshaft 7).

As still another example, when the authentication by the authentication unit 32b is successful, the restriction release operation is performed on the UI device 50, and the conditions regarding the running environment of the bicycle 100 are satisfied, the mode selection unit 32 may select the unrestricted mode. The conditions regarding the running environment of the bicycle 100 are, for example, the slope of the road on which the bicycle 100 is running and the vibration of the bicycle 100 . The slope of the road and the vibration of the bicycle 100 can be detected, for example, by an acceleration sensor that outputs a signal corresponding to vertical acceleration.

[Mode guide]
When the restriction release mode is selected, the mode guidance unit 33 (see FIG. 4) displays that the restriction release mode is selected by the restriction release indicator 53d (see FIG. 3). For example, when the restriction release indicator 53d is an LED, the mode guide section 33 lights or blinks the restriction release indicator 53d.

In the example shown in FIG. 3, the UI device 50 has mode indicators 53a-53c corresponding to high mode, medium mode, and low mode, respectively. The mode guide unit 33 lights or flashes the mode indicators 53a to 53c corresponding to the currently selected control mode (high mode, medium mode, or weak mode).

[Multiple assist ratio regulation information that can be used in restriction release mode]
A plurality of pieces of assist ratio defining information used in the restriction release mode may be stored in the storage device 30a. FIG. 8 is a diagram showing an example of such assist ratio defining information. In this figure, three upper limit assist ratios indicated by solid lines E4, E5 and E6 are shown as examples of the upper limit of the assist ratio defined by the assist ratio defining information referred to in the limit release mode. Hereinafter, the control mode in which the upper limit assist ratio indicated by the solid line E4 is allowed is referred to as a "first restriction cancellation mode", and the control mode in which the upper limit assistance ratio indicated by the solid line E5 is allowed is referred to as a "second restriction cancellation mode". A control mode in which the upper limit assist ratio of E6 is permitted is referred to as a "third restriction release mode".

As shown in FIG. 8, the assist ratio defining information (solid line E4) for the first control release mode defines an upper limit assist ratio that is higher than the upper limit assist ratio for the strong mode in a vehicle speed range higher than the vehicle speed V1. This assist ratio defining information defines the upper limit assist ratio R1 for the strong mode in the vehicle speed range lower than the vehicle speed V3, and defines the upper limit assist ratio that decreases as the vehicle speed increases in the vehicle speed range higher than the vehicle speed V3. there is

The second control release mode assist ratio regulating information (solid line E5) defines the upper limit assist ratio corresponding to the upper limit assist ratio R2 of the middle mode for the vehicle speed range lower than the vehicle speed V3, and for the vehicle speed range higher than the vehicle speed V3. , defines the upper limit assist ratio that decreases as the vehicle speed increases. Further, this assist ratio defining information defines an upper limit assist ratio higher than the upper limit assist ratio of the strong mode in a vehicle speed range higher than vehicle speed V6 (V1<V6<V3).

The assist ratio regulating information (solid line E6) for the third control release mode defines the upper limit assist ratio corresponding to the upper limit assist ratio R3 of the weak mode for the vehicle speed range lower than the vehicle speed V3, and for the vehicle speed range higher than the vehicle speed V3. , defines the upper limit assist ratio that decreases as the vehicle speed increases. Further, the assist ratio defining information defines an upper limit assist ratio higher than the upper limit assist ratio of the strong mode in a vehicle speed range higher than vehicle speed V7 (V3<V7<V2).

Thus, the upper limit assist ratios (solid lines E4, E5, E6) defined by the three pieces of assist ratio defining information have a vehicle speed range in which a higher assist ratio than the high mode assist ratio is defined.

Note that the number of pieces of assist ratio defining information that can be used in the restriction release mode is not limited to three, and may be two or four or more. The upper limit assist ratios defined in the vehicle speed range lower than the vehicle speed V3 by the assist ratio defining information used in the restriction release mode do not necessarily correspond to the upper limit assist ratios R1, R2, and R3 of the strong mode, medium mode, and weak mode, respectively. It doesn't have to be.

As shown in FIG. 8, when a plurality of pieces of assist ratio defining information are defined for the restriction cancellation mode, the mode selection unit 32 selects a value based on the driver's operation input after authentication by the authentication unit 32b is successful. , the assist ratio defining information (solid lines E4, E5, E6) used in the restriction release mode may be changed. FIG. 9 is a diagram showing an example of such processing by the mode selection unit 32. As shown in FIG.

The authentication unit 32b determines whether or not the authentication has succeeded (S201). Here, if the authentication is successful, the mode selection unit 32 preliminarily selects from the above-described three restriction release modes (three assist ratio defining information defining the upper limit assist indicated by the solid lines E4, E5, and E6 in FIG. 8). Either one is selected according to a defined rule (S202).

For example, when the authentication is successful in S201, the mode selection unit 32 may select the control mode according to the control mode (strong mode, medium mode, or weak mode) immediately before the authentication succeeds. Specifically, when the strong mode is selected immediately before the authentication succeeds, the first restriction release mode (solid line E4 in FIG. 8) that defines the highest upper limit assist ratio among the three restriction release modes is selected. you can When the middle mode is selected immediately before the authentication succeeds, the second restriction release mode (solid line E5 in FIG. 8) that defines the middle upper limit assist ratio among the three restriction release modes may be selected. When the small mode is selected immediately before the authentication succeeds, the third restriction release mode (solid line E6 in FIG. 8) that defines the smallest upper limit assist ratio among the three restriction release modes may be selected. When the mode selection unit 32 selects the strong mode, the medium mode, or the weak mode, it stores information indicating that fact in the storage device 30a. Then, the mode selection unit 32 may use the information to execute the process of S201.

As another example, the mode selection unit 32 may select a predetermined mode from three restriction release modes (first to third restriction release modes) when the authentication is successful in S201. For example, the mode selection unit 32 may select successful authentication and a second restriction release mode (solid line E5 in FIG. 8) that defines a medium upper limit assist ratio among the three restriction release modes.

The mode selection unit 32 determines whether or not the up button 52a (see FIG. 3) has been operated (S203). Here, when the up button 52a is operated (pressed), the mode selection unit 32 selects a strong mode (that is, a mode closer to the first restriction release mode (solid line E4)) (S204). For example, when the up button 52a is operated while the third restriction release mode (solid line E6) is selected, the mode selector 32 selects the second restriction release mode (solid line E5). When the up button 52a is operated while the second restriction release mode (solid line E5) is selected, the mode selector 32 selects the first restriction release mode (solid line E4). If the first restriction release mode has already been selected, the process of S204 need not be performed.

On the other hand, if the up button 52a has not been operated in S203, the mode selection unit 32 determines whether or not the down button 52b (see FIG. 3) has been operated (S205). Here, when the down button 52b is operated (pressed), the mode selection unit 32 selects a weaker mode (that is, closer to the third restriction release mode (solid line E6)) (S206). For example, when the down button 52b is operated while the first restriction release mode (solid line E4) is selected, the mode selector 32 selects the second restriction release mode (solid line E5). When the down button 52b is operated while the second restriction release mode (solid line E5) is selected, the mode selection unit 32 selects the third restriction release mode (solid line E6). Note that if the third restriction release mode has already been selected, the process of S206 need not be performed.

After the processing of S204 and S206, the mode selection unit 32 determines whether or not an operation for instructing to stop the selection of the restriction release mode (that is, the selection stop operation described above) has been performed on the UI device 50. (S207). Here, when the selection stop operation is performed, the mode selection unit 32 stops the selection of the restriction release mode (S208), and selects one of the strong mode, medium mode, and weak mode according to a predetermined rule. . On the other hand, if the selection stop operation has not been performed in S207, the mode selection unit 32 returns to S203 and continues the subsequent processing. Further, when the down button 52b is not operated in S205, the mode selection unit 32 proceeds to the process of S207 without going through the process of S206. The above is an example of the processing of the mode selection unit 32 related to selection of the restriction release mode.

In the example shown in FIG. 8, a plurality of pieces of assist ratio defining information (solid lines E4, E5, E6) are provided for the restriction release mode. Therefore, the driver (user) can select the assist ratio defining information (first to third limit release modes) that realizes the most desirable assist ratio after shifting to the limit release mode. Also, since authentication is executed before the selection of the assist ratio stipulating information, these restriction release modes are allowed only for users who are suitable for using the first to third restriction release modes. can.

Note that the storage device 30a does not necessarily store the three maps corresponding to the first to third restriction release modes. For example, the storage device 30a may store only the map of the first restriction release mode. In this case, when the second restriction release mode is selected, the motor control unit 31 calculates the assist ratio for the second restriction release mode based on the assist ratio obtained from this map and the correction coefficient. good. Similarly, when the third restriction release mode is selected, the motor control unit 31 may calculate the assist ratio for the third restriction release mode based on the assist ratio obtained from this map and the correction coefficient. .

[Second example: use of pedaling ability]
FIG. 10 is a block diagram showing a modified example of the bicycle 100 proposed in this disclosure. FIG. 11 is a block diagram showing functions of a modification of the control device 30 proposed in the present disclosure.

In the example shown in FIG. 11, the mode selection section 32 has a pedaling ability evaluation section 32d. The pedaling ability evaluation unit 32d calculates an "ability evaluation value" representing the pedaling ability of the driver. For example, when the calculated ability evaluation value is higher than the threshold, the mode selection unit 32 allows selection of the restriction release mode.

[Pedaling ability]
The pedaling ability is evaluated based on the pedaling force detected by the pedaling force sensor 41, the cadence (rotational speed of the crankshaft 7) detected by the crank rotation sensor 45 (see FIG. 10), and the like. FIG. 12 is a three-dimensional map for converting pedal force and cadence into ability evaluation values. Below, this map is called a "conversion map." In the conversion map, ability evaluation values are associated with cadence and pedaling force. The ability evaluation value defined by the conversion map in FIG. 12 increases, for example, as the cadence increases. Similarly, the ability evaluation value defined in the conversion map increases, for example, as the pedaling force increases.

Pedaling ability may be evaluated based on left-right balance in addition to pedaling force and cadence, or instead of either pedaling force or cadence. That is, the ability evaluation value described above may be calculated based on the left-right balance. The bicycle 100 includes an acceleration sensor 46 (see FIG. 10) that outputs a signal corresponding to lateral acceleration, and an angle sensor 47 (see FIG. 10) that outputs a signal corresponding to the rotation angle of the handle stem 8 (see FIG. 1). ). If the change in acceleration in the left-right direction is large, or if the rotation angle of the handle stem 8 changes frequently, it can be evaluated that the balance is not good. Therefore, the pedaling ability evaluation unit 32 d may calculate the ability evaluation value based on the output of the acceleration sensor 46 and/or the output of the angle sensor 47 .

Also, the pedaling ability is evaluated based on the response speed of the driver to the load in addition to or instead of the above-mentioned three elements (pedal force, cadence, and balance). good too. That is, the ability evaluation value may be calculated based on the driver's response speed to the load. Bicycle 100 includes an acceleration sensor that outputs a signal corresponding to acceleration in at least one of the longitudinal direction and the vertical direction, and pedal force sensor 41 described above. The pedaling ability evaluation unit 32d calculates the temporal difference between the occurrence of load (for example, the arrival of an uphill) and the change in pedaling force based on the output of the acceleration sensor and the output of the pedaling force sensor 41, for example. do. If this difference is large, it can be evaluated that the driver's reaction speed to the load is low. Therefore, the pedaling ability evaluation section 32d may calculate the ability evaluation value based on this difference.

Pedaling ability may be evaluated based on, for example, the driver's explosive power and sustained power, as well as pedaling force, cadence, balance, and reaction speed described herein. The instantaneous force can be calculated, for example, based on the instantaneous magnitude of the pedaling force, and the sustained force can be calculated based on the average value of the pedaling force over a predetermined period of time.

For example, when the calculated ability evaluation value is higher than the threshold, the mode selection unit 32 allows selection of the restriction release mode. Further, the mode selection unit 32 may allow selection of the restriction release mode, for example, when the ability evaluation value higher than the threshold continues for a predetermined time or longer. According to such a control device 30, only a driver with high pedaling ability can be allowed to travel in the restriction release mode.

[Start Restriction Release Mode]
The mode selection unit 32 selects the restriction release mode when the calculated ability evaluation value is higher than the threshold or when the ability evaluation value higher than the threshold continues for a predetermined time or longer. Then, the motor control unit 31 starts controlling the electric motor 14 using the assist ratio defining information in the limit release mode described with reference to FIGS. 6A to 6D, for example.

As another example, the mode selection unit 32 may select the restriction release mode when a performance evaluation value higher than a threshold is calculated and a predetermined operation is performed on the UI device 50 . For example, the mode selection unit 32 may select the restriction release mode when an ability evaluation value higher than the threshold is calculated and then the up button 52a is operated once or multiple times. Then, the motor control unit 31 may start controlling the electric motor 14 based on the assist ratio defining information in the restriction release mode. According to this, the control of the electric motor 14 in the limit release mode is started in a situation where the driver clearly indicates the need for assistance in the limit release mode.

[Hysteresis]
The mode selection unit 32 may determine whether or not to stop selecting the restriction release mode when the restriction release mode is selected. When the selection of the restriction release mode is stopped, the mode selection unit 32 may select one of the control modes allowed for any driver, such as the strong mode, the medium mode, and the weak mode.

The mode selection unit 32 may determine whether or not to stop selecting the restriction release mode, for example, based on the ability evaluation value. In this case, hysteresis may be provided between selection of the restriction release mode and cancellation of selection of the restriction release mode.

For example, the mode selection unit 32 may stop selecting the strong mode and select the restriction release mode when the ability evaluation value calculated while the strong mode is selected exceeds the first threshold value N5. . Further, the mode selection unit 32 stops selecting the restriction release mode when the ability evaluation value calculated while the restriction release mode is selected falls below a second threshold value N6 that is lower than the first threshold value N5. , may return to strong mode. According to this, excessively frequent switching between the restriction release mode and the other control modes (strong mode, medium mode, weak mode) can be suppressed.

[Mode for changing the vehicle speed at which the assist ratio starts to decrease]
FIG. 13 is a diagram showing an example of the upper limit assist ratio defined by the assist ratio defining information used in the limit release mode. In this figure, the upper limit assist ratios (solid lines E4, E5, E6) defined by three pieces of assist ratio defining information used in the restriction release mode are shown. The three pieces of assist ratio defining information shown in this figure respectively define upper limit assist ratios corresponding to the upper limit assist ratio R1 of the strong mode for vehicle speed ranges lower than vehicle speeds V7, V8, and V9. Further, the upper limit assist ratio indicated by the solid line E4 decreases as the vehicle speed increases in the vehicle speed range higher than the vehicle speed V7. The upper limit assist ratio indicated by the solid line E5 decreases as the vehicle speed increases in the vehicle speed range higher than the vehicle speed V8. The upper limit assist ratio indicated by the solid line E6 decreases as the vehicle speed increases in the vehicle speed range higher than the vehicle speed V9.

The mode selection unit 32 may select any one of the plurality of assist ratio defining information described above based on the calculated ability evaluation value. For example, when the ability evaluation value is within the range of the first threshold value N1 to the second threshold value N2 (N2>N1), the assist ratio defining information (solid line E4) defining the lowest assist ratio may be selected. Further, when the ability evaluation value is within the range of the second threshold value N2 to the third threshold value N3 (N3>N2), the assist ratio stipulating information (solid line E5) specifying a medium assist ratio may be selected. . Furthermore, when the ability evaluation value is within the range of the third threshold value N3 to the fourth threshold value N4 (N4>N3), the assist ratio defining information (solid line E6) defining the highest assist ratio may be selected.

According to such processing of the mode selection unit 32, in the restriction release mode, the vehicle speed V7, V8, or V9 (see FIG. 13) at which the upper limit assist ratio starts to decrease as the vehicle speed increases is the driver's (user's) pedal position. It will change according to rowing ability. As a result, for example, for a driver with a high pedaling ability, control of the electric motor 14 with a high assist ratio (for example, control based on assist ratio defining information defining an upper limit assist ratio indicated by solid line E6) is executed. It will happen.

[Third example: Use of driving environment]
FIG. 14 is a block diagram showing a modified example of the bicycle 100 proposed in the present disclosure. FIG. 15 is a block diagram showing functions of a modification of the control device 30 proposed in the present disclosure.

In the example shown in FIG. 15, the mode selection unit 32 has a driving environment determination unit 32e. The driving environment determination unit 32e determines whether or not selection of the restriction release mode is permitted based on the driving environment.

The running environment is the environment in which the bicycle 100 is running. An example of the riding environment is the slope of the road on which the bicycle 100 is traveling. The driving environment determination unit 32e may calculate the inclination of the road, for example, based on the output of the acceleration sensor 48 (see FIG. 14) that outputs a signal corresponding to acceleration in the longitudinal direction or the vertical direction. The driving environment determination unit 32e may allow selection of the restriction release mode when the slope of the road is greater than the threshold.

Another example of the running environment is the condition of the road surface on which the bicycle 100 is running. For example, the vibration of the bicycle 100 increases on gravel roads. Therefore, the riding environment determination unit 32e may allow selection of the restriction release mode when the vibration occurring in the bicycle 100 is smaller than the threshold. The vibration of bicycle 100 can be calculated based on the output of acceleration sensor 48 (see FIG. 14) that outputs a signal corresponding to vertical acceleration.

Yet another example of the riding environment is the load acting on bicycle 100 . When a large load is acting on the bicycle 100, even if a large torque is transmitted to the rear wheels 4, the change in vehicle speed (that is, acceleration) is small. Therefore, the riding environment determination unit 32e calculates the load acting on the bicycle 100, for example, based on the torque transmitted to the rear wheels 4 and changes in vehicle speed. Here, the torque transmitted to the rear wheels 4 includes torque transmitted from the pedals 6 and torque transmitted from the electric motor 14 . A torque transmitted from the pedal 6 can be detected by a pedaling force sensor 41 . The torque transmitted from the electric motor 14 to the rear wheels 4 can be calculated based on the current supplied from the motor drive device 13 to the electric motor 14 .

As shown in FIG. 14, the drive system of the bicycle 100 may have a camera 49 for photographing the surroundings of the bicycle 100. As shown in FIG. Still another example of the running environment may be the brightness around the bicycle 100, the weather, congestion, and the like. The driving environment determination unit 32e may detect the brightness of the surroundings from the image data acquired by the camera 49. FIG. Ambient brightness can be calculated based on the brightness of the image data. The driving environment determination unit 32e may detect the weather from the image data acquired by the camera 49. FIG. The driving environment determination unit 32e may detect the surrounding congestion situation from the image data acquired by the camera 49. FIG. The driving environment determination unit 32e may execute an image processing algorithm such as template matching to detect raindrops and obstacles (including surrounding people).

As described with reference to FIG. 13, the storage device 30a may store a plurality of pieces of assist ratio defining information used in the restriction release mode. Based on the driving environment detected by the driving environment determination unit 32e, the mode selection unit 32 may select a map suitable for the driving environment from a plurality of pieces of assist ratio defining information.

[summary]
As described above, the drive system of the power-assisted bicycle 100 differs from the user interface device 50 having the up button 52a and the down button 52b for receiving the mode selection operation by the rider and the assist ratio. Detected by a mode selection unit 32 that selects a first control mode according to a mode selection operation from a plurality of first control modes (strong mode, medium mode, and weak mode) that can be selected by a mode selection operation, and by a vehicle speed sensor 42 and a motor control unit 31 for controlling the electric motor 14 in the selected first control mode based on the vehicle speed. The motor control unit 31 includes, as control modes for the electric motor 14, a plurality of first control modes and a limit release mode. The upper limit assist ratio, which is the upper limit of the assist ratio realized by driving the electric motor 14, is specified by the assist ratio specifying information for the plurality of first control modes and the restriction cancellation mode. The strong mode defines the highest upper limit assist ratio among the plurality of first control modes. Further, the upper limit assist ratio of the strong mode is defined so as to decrease as the vehicle speed increases in a vehicle speed range higher than the first vehicle speed V1. In the limit release mode, a higher upper limit assist ratio than in the strong mode is defined in a vehicle speed range higher than the first vehicle speed V1 when compared at the same vehicle speed. According to this drive system, a higher assist ratio than the plurality of first control modes that can be selected by the mode selection operation can be achieved by using the restriction cancellation mode.

(1) In the first example described with reference to FIGS. 2 to 9, the mode selection unit 32 permits selection of the restriction release mode on the condition that the driver has been successfully authenticated. According to this drive system, only drivers who have been successfully authenticated can be allowed to use the restriction release mode.

(2) In the second example described with reference to FIGS. 10 to 13, the mode selection unit 32 allows selection of the restriction release mode when the user's pedaling ability satisfies a predetermined condition. According to this drive system, only a driver having a pedaling ability that satisfies a predetermined condition can be allowed to use the restriction release mode.

(3) In the third example described with reference to FIGS. 14 and 15, the mode selection unit 32 allows selection of the restriction release mode when the driving environment satisfies a predetermined condition. According to this drive system, the driver can be allowed to use the limited release mode only in a driving environment that satisfies a predetermined condition.

(4) In the strong mode, the assist ratio defining information (FIG. 5) that associates the vehicle speed and the assist ratio is used. , FIGS. 8 and 13) are utilized. The strong mode assist ratio defining information defines the first assist ratio R1 as the upper limit assist ratio for the vehicle speed range lower than the first vehicle speed V1, and the upper limit assist ratio that decreases as the vehicle speed increases for the vehicle speed range higher than the first vehicle speed V1. It defines the ratio. The assist ratio stipulating information for the limit release mode specifies an assist ratio higher than the upper limit assist ratio stipulated for the strong mode in a range of vehicle speeds higher than the first vehicle speed V1 when compared at the same vehicle speed.

(5) The upper limit assist ratio of the strong mode is the first assist ratio R1 in the vehicle speed range lower than the first vehicle speed V1. As described with reference to FIG. 6A and the like, the upper limit assist ratio defined in the limit release mode is the first assist ratio R1 in at least part of the vehicle speed range higher than the first vehicle speed V1.

(6) As described with reference to FIG. 6A and the like, the upper limit assist ratio defined for the restriction release mode increases as the vehicle speed increases in a vehicle speed range higher than the second vehicle speed V3, which is higher than the first vehicle speed V1. Assist ratio decreases.

(7) In the first example, the user interface device 50 (FIG. 3) has a plurality of input buttons 52a to 52e for receiving operations by the driver. The mode selection unit 32 determines that the authentication is successful when a predetermined authentication operation is performed on the plurality of input buttons 52a to 52e, and allows selection of the restriction release mode. According to this, the authentication operation can be performed without using a dedicated device or parts.

(8) As described with reference to FIG. 4, in the first example, the mode selection unit 32 sets a predetermined authentication operation based on the driver's operation of the plurality of input buttons 52a to 52e. It may have a setting unit 32c. According to this, the user can change the authentication operation as necessary.

(9) In the first example, the input buttons used for authentication processing include buttons for the driver to switch between a plurality of first control modes (strong mode, medium mode, weak mode). According to this, it is possible to suppress an increase in the number of parts of the user interface device.
A button may be included for the driver to switch between strong and weak modes.

(10) In the first example, the mode selection unit 32 switches to the restriction release mode when a predetermined selection stop operation is performed on the plurality of input buttons 52a to 52e while the restriction release mode is selected. Stop choosing. According to this, the driver can easily return to any one of the plurality of first control modes.

(11) In the first example, the drive system has a connection section (key cylinder 43, communication module 44) for connecting an authentication device or an authentication part. The mode selection unit 32 determines that the authentication is successful when the authentication device or the authentication component is connected to the connection unit, and allows selection of the restriction release mode. Here, the authentication device is, for example, a mobile terminal owned by the owner of the bicycle, and the authentication component is, for example, a mechanical key or an electronic key.

(12) In the second example, the mode selection unit 32 selects at least one of the force acting on the pedals 6, the number of rotations of the crankshaft 7, the left-right balance, and the response speed to the load as the pedaling ability of the user. One is used to determine whether or not to permit the selection of the release mode.

(13) In the second example, the vehicle speed (V7, V8, V9) at which the upper limit assist ratio begins to decrease changes according to the pedaling ability of the driver. According to this, a more comfortable run can be provided.

(14) In the third example, the driving environment is at least one of road inclination, road surface condition, load acting on the bicycle, ambient brightness of the bicycle, weather, and congestion.

The power-assisted bicycle and its drive system proposed in the present disclosure are not limited to the examples described above, and may be modified in various ways.

1: frame, 1a: head pipe, 1b: seat tube, 2: saddle, 3: front wheel, 4: rear wheel, 5: chain, 6: pedal, 7: crankshaft, 8: handle stem, 8a: front fork, 9: Handle, 13: Motor drive device, 14: Electric motor, 15: Battery, 20: Drive unit, 21: Reducer, 22: Resultant force transmission mechanism, 30: Control device, 30a: Storage device, 31: Motor control unit, 32: Mode selection unit 32b: Authentication unit 32c: Authentication operation setting unit 32d: Pedaling ability evaluation unit 32e: Driving environment determination unit 33: Mode guide unit 41: Pedal force sensor 42: Vehicle speed sensor 43 : key cylinder, 44: communication module, 45: crank rotation sensor, 46: acceleration sensor, 47: angle sensor, 48: acceleration sensor, 49: camera, 50: user interface device (UI device), 52a: up button, 52b : Down button 52c: Display selection button 52d: Light control button 52e: Power button 53a to 53c: Mode indicator 53d: Limit release indicator 53e: Numerical indicator 53f: Battery level indicator 100: Electric power assist bicycle.

Claims (18)

a user interface device having at least one input unit for receiving a mode selection operation by a driver;
a mode selection unit that selects a first control mode according to the mode selection operation from a plurality of first control modes selectable by the mode selection operation;
a motor control unit that controls the electric motor in the selected first control mode based on the vehicle speed detected by the sensor;
The motor control section includes the plurality of first control modes and a second control mode as control modes of the electric motor, and each of the plurality of first control modes and the second control mode includes: , an upper limit assist ratio that is the upper limit of the assist ratio realized by driving the electric motor is defined,
One of the plurality of first control modes defines the highest upper limit assist ratio among the plurality of first control modes, and the one upper limit assist ratio of the plurality of first control modes is , is defined to decrease as the vehicle speed increases in a vehicle speed range higher than the first vehicle speed,
The second control mode defines an upper limit assist ratio that is higher than the one of the plurality of first control modes when compared at the same vehicle speed in a vehicle speed range higher than the first vehicle speed,
The drive system for a power-assisted bicycle, wherein the mode selection unit permits the selection of the second control mode on condition that the authentication of the driver is successful. a user interface device having at least one input unit for receiving a mode selection operation by a driver;
a mode selection unit that selects a first control mode according to the mode selection operation from a plurality of first control modes selectable by the mode selection operation;
a motor control unit that controls the electric motor in the selected first control mode based on the vehicle speed detected by the sensor;
The motor control section includes the plurality of first control modes and a second control mode as control modes of the electric motor, and each of the plurality of first control modes and the second control mode includes: , an upper limit assist ratio that is the upper limit of the assist ratio realized by driving the electric motor is defined,
One of the plurality of first control modes defines the highest upper limit assist ratio among the plurality of first control modes, and the one upper limit assist ratio of the plurality of first control modes is , is defined to decrease as the vehicle speed increases in a vehicle speed range higher than the first vehicle speed,
The second control mode defines an upper limit assist ratio that is higher than the one of the plurality of first control modes when compared at the same vehicle speed in a vehicle speed range higher than the first vehicle speed,
The mode selection unit allows selection of the second control mode when a user's pedaling ability satisfies a predetermined condition. Driving system for an electrically assisted bicycle. a user interface device having at least one input unit for receiving a mode selection operation by a driver;
a mode selection unit that selects a first control mode according to the mode selection operation from a plurality of first control modes selectable by the mode selection operation;
a motor control unit that controls the electric motor in the selected first control mode based on the vehicle speed detected by the sensor;
The motor control section includes the plurality of first control modes and a second control mode as control modes of the electric motor, and each of the plurality of first control modes and the second control mode includes: , an upper limit assist ratio that is the upper limit of the assist ratio realized by driving the electric motor is defined,
One of the plurality of first control modes defines the highest upper limit assist ratio among the plurality of first control modes, and the one upper limit assist ratio of the plurality of first control modes is , is defined to decrease as the vehicle speed increases in a vehicle speed range higher than the first vehicle speed,
The second control mode defines an upper limit assist ratio that is higher than the one of the plurality of first control modes when compared at the same vehicle speed in a vehicle speed range higher than the first vehicle speed,
The drive system for a power-assisted bicycle, wherein the mode selection unit allows selection of the second control mode when a running environment satisfies a predetermined condition. In the one of the plurality of first control modes, first assist ratio defining information that associates the vehicle speed with the assist ratio is used,
In the second control mode, the second assist ratio defining information that associates the vehicle speed and the assist ratio is used,
The first assist ratio defining information defines the first assist ratio as the upper limit assist ratio for a vehicle speed range lower than the first vehicle speed, and the upper limit that decreases as the vehicle speed increases for a vehicle speed range higher than the first vehicle speed. define the assist ratio,
The second assist ratio defining information defines an upper limit assist ratio that is higher than the upper limit assist ratio defined by the first assist ratio defining information when compared at the same vehicle speed for a range of vehicle speeds higher than the first vehicle speed. The drive system for a power-assisted bicycle according to any one of claims 1 to 3. the upper limit assist ratio defined for the one of the plurality of first control modes is a first assist ratio in a vehicle speed range lower than the first vehicle speed;
The power-assisted bicycle according to any one of claims 1 to 3, wherein the upper limit assist ratio defined in the second control mode is the first assist ratio in at least part of a vehicle speed range higher than the first vehicle speed. drive system. 4. The upper limit assist ratio defined for the second control mode according to any one of claims 1 to 3, wherein the upper limit assist ratio decreases as the vehicle speed increases in a vehicle speed range higher than the second vehicle speed higher than the first vehicle speed. A drive system for an electrically assisted bicycle. The user interface device includes a plurality of input units that accept a driver's operation, including the at least one input unit,
2. The mode selection unit according to claim 1, wherein when a predetermined authentication operation is performed on the plurality of input units, the mode selection unit determines that authentication has succeeded and allows selection of the second control mode. A drive system for an electrically assisted bicycle. 8. The power-assisted bicycle drive system according to claim 7, further comprising an authentication operation setting unit that sets the predetermined authentication operation based on a driver's operation on the plurality of input units. The power-assisted bicycle drive system according to claim 7, wherein the at least one input section includes a button for a rider to switch between the plurality of first control modes. 2. The mode selection unit stops selecting the second control mode when a predetermined selection stop operation is performed on the plurality of input units while the second control mode is selected. The drive system for the electrically assisted bicycle described in . further comprising a connecting portion for connecting an authentication device or an authentication component;
2. The mode selection unit according to claim 1, wherein when the authentication device or the authentication component is connected to the connection unit, the mode selection unit determines that the authentication has succeeded and allows the selection of the second control mode. A drive system for an electrically assisted bicycle. The mode selection unit uses at least one of the force acting on the pedal, the number of rotations of the pedal, the left-right balance, and the response speed to a load as the pedaling ability of the user to select the second mode. 3. The power-assisted bicycle drive system according to claim 2, wherein the drive system for a power-assisted bicycle according to claim 2, determines whether or not to allow selection of the control mode. The upper limit assist ratio defined for the second control mode decreases as the vehicle speed increases in a vehicle speed range higher than a second vehicle speed higher than the first vehicle speed,
3. The power-assisted bicycle drive system according to claim 2, wherein the second vehicle speed changes according to the pedaling ability of the driver. 4. The electric power assist according to claim 3, wherein the driving environment is at least one of road inclination, road surface condition, load acting on the bicycle, brightness around the bicycle, weather, and congestion. Bicycle drive system. An electrically assisted bicycle equipped with the drive system according to claim 1, 2 or 3. A control method for a power-assisted bicycle having a user interface device having at least one input unit for receiving a mode selection operation by a rider, comprising:
a mode selection step of selecting a first control mode according to the mode selection operation from among a plurality of first control modes selectable by the mode selection operation and having mutually different assist ratios;
a motor control step of controlling the electric motor in the selected first control mode based on the vehicle speed detected by the sensor;
The motor control step includes the plurality of first control modes and a second control mode as control modes of the electric motor, and each of the plurality of first control modes and the second control mode includes: , an upper limit assist ratio that is the upper limit of the assist ratio realized by driving the electric motor is defined,
One of the plurality of first control modes defines the highest upper limit assist ratio among the plurality of first control modes, and the one upper limit assist ratio of the plurality of first control modes is , is defined to decrease as the vehicle speed increases in a vehicle speed range higher than the first vehicle speed,
The second control mode defines an upper limit assist ratio that is higher than the one of the plurality of first control modes when compared at the same vehicle speed in a vehicle speed range higher than the first vehicle speed,
In the mode selection step, it is determined whether or not the selection of the second control mode is allowed on condition that the authentication performed for the driver is successful. A control method for a power-assisted bicycle having a user interface device having at least one input unit for receiving a mode selection operation by a rider, comprising:
a mode selection step of selecting a first control mode according to the mode selection operation from among a plurality of first control modes selectable by the mode selection operation and having mutually different assist ratios;
a motor control step of controlling the electric motor in the selected first control mode based on the vehicle speed detected by the sensor;
The motor control step includes the plurality of first control modes and a second control mode as control modes of the electric motor, and each of the plurality of first control modes and the second control mode includes: , an upper limit assist ratio that is the upper limit of the assist ratio realized by driving the electric motor is defined,
One of the plurality of first control modes defines the highest upper limit assist ratio among the plurality of first control modes, and the one upper limit assist ratio of the plurality of first control modes is , is defined to decrease as the vehicle speed increases in a vehicle speed range higher than the first vehicle speed,
The second control mode defines an upper limit assist ratio that is higher than the one of the plurality of first control modes when compared at the same vehicle speed in a vehicle speed range higher than the first vehicle speed,
In the mode selection step, the selection of the second control mode is permitted when the user's pedaling ability satisfies a predetermined condition. A control method for a power-assisted bicycle having a user interface device having at least one input unit for receiving a mode selection operation by a rider, comprising:
a mode selection step of selecting a first control mode according to the mode selection operation from among a plurality of first control modes selectable by the mode selection operation and having mutually different assist ratios;
a motor control step of controlling the electric motor in the selected first control mode based on the vehicle speed detected by the sensor;
The motor control step includes the plurality of first control modes and a second control mode as control modes of the electric motor, and each of the plurality of first control modes and the second control mode includes: , an upper limit assist ratio that is the upper limit of the assist ratio realized by driving the electric motor is defined,
One of the plurality of first control modes defines the highest upper limit assist ratio among the plurality of first control modes, and the one upper limit assist ratio of the plurality of first control modes is , is defined to decrease as the vehicle speed increases in a vehicle speed range higher than the first vehicle speed,
The second control mode defines an upper limit assist ratio that is higher than the one of the plurality of first control modes when compared at the same vehicle speed in a vehicle speed range higher than the first vehicle speed,
In the mode selection step, when a running environment satisfies a predetermined condition, the selection of the second control mode is permitted based on a control method for a power-assisted bicycle.

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