JP2017154564A - Power-assisted bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power-assisted bicycle capable of applying proper auxiliary driving force according to a travel environment.SOLUTION: A power-assisted bicycle 10 comprises: pedals 18 to which human tread force is applied; a crank 16 which is coupled to the pedals 18, and to which a torque corresponding to the tread force is applied; a torque detection unit 43 for detecting a torque; a rotation number detection unit 44 for detecting a rotation number of the crank; an electric motor 20 for generating auxiliary driving force; and a control device 31 for controlling the auxiliary driving force of the electric motor 20. The control device 31 shifts a mode of the auxiliary driving force of the electric motor 20 to a high assist mode from a normal assist mode, on and after a timing when, an increasing rate of the torque becomes a prescribed threshold or more, and a reduction rate of the rotation number becomes a prescribed threshold or more.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an improvement in an electrically assisted bicycle having a human power drive system that transmits a pedaling force applied to a pedal and an electric power drive system that transmits auxiliary power by an electric unit.

  In recent years, auxiliary power of an electric power drive system that transmits power from an electric unit such as an electric motor is applied to a human power drive system generated by a driver stepping on a pedal to assist driving, thereby allowing the driver to pedal. Electric assist bicycles that reduce the force of stepping on are known.

  In an electrically assisted bicycle, pedal input torque is smoothed, and motor control is performed based on the smoothed torque. By smoothing the pedal input torque, a predetermined output torque is output even at a pedal position where the pedal effort is reduced, so that a good assist feeling can be obtained.

  The electrically assisted bicycle described in Patent Document 1 detects an input torque input from a pedal, calculates a smoothed torque value obtained by smoothing a change in the input torque, and calculates a smoothed torque value and a preset assist ratio. A controller that calculates an assist torque value based on the control torque and drives the motor in accordance with the assist torque value, and the controller includes a depressing detection unit that detects depressing of the pedal while the pedal is running; And a correction means for correcting at least one of a smoothing rate, an assist ratio, and a smoothing torque value for calculating a smoothing torque value by detecting pedal depression during traveling.

  With such a configuration, for example, when the vehicle is going uphill from a flat ground or when the traveling speed is temporarily increased, the assist torque against the pedal depressing when the pedal is depressed to increase the pedal depressing force during traveling. The value can be temporarily increased. Therefore, it is possible to obtain appropriate auxiliary power in accordance with the occupant's intention, and to improve the running feeling.

Japanese Patent Laying-Open No. 2015-182600

  According to the invention described in Patent Document 1, the assist torque value increases in response to the pedal being depressed again regardless of the driving environment. However, an aspect in which the assist torque value always increases in response to the re-depression of the pedal may not be desirable in a traveling environment such as a flat ground.

  The present invention has been made under such a background, and an object thereof is to provide an electric assist bicycle capable of applying an appropriate auxiliary driving force in accordance with a traveling environment.

  The present invention is an electrically assisted bicycle, a pedal to which a human pedaling force is applied, a crank connected to the pedal and to which a torque corresponding to the pedaling force is applied, and a torque detection unit for detecting the torque, A rotational speed detection unit that detects the rotational speed of the crank, an electric motor that generates an auxiliary driving force, and a control device that controls the auxiliary driving force of the electric motor. The mode of the auxiliary driving force of the electric motor is changed from the normal assist mode to the high assist mode after the timing when the increase rate becomes equal to or higher than a predetermined threshold and the decrease rate of the rotation speed becomes equal to or higher than the predetermined threshold.

  As an embodiment of the present invention, for example, the control device increases the value of the auxiliary driving force after the timing.

  As an embodiment of the present invention, for example, after the timing, the control device increases an assist ratio that is a ratio of the auxiliary driving force to the torque corresponding to the pedal effort.

  As an embodiment of the present invention, for example, the control device increases the peak value of the auxiliary driving force taken every predetermined fluctuation period after the timing.

  As an embodiment of the present invention, for example, the control device transitions the auxiliary driving force mode of the electric motor from the normal assist mode to the high assist mode after a predetermined detection period has elapsed after the timing.

  As an embodiment of the present invention, for example, the control device determines whether the torque increase rate is equal to or greater than a predetermined threshold value and that the rotational speed decrease rate is equal to or greater than a predetermined threshold value due to erroneous detection. Determine.

  As an embodiment of the present invention, for example, the control device changes the auxiliary driving force mode of the electric motor from the normal assist mode to the elapsed assist mode in a predetermined detection period after the timing, and the elapse of the detection period. Later, the mode of the auxiliary driving force of the electric motor is changed from the elapsed assist mode to the high assist mode.

  According to the present invention, an appropriate auxiliary driving force is electrically driven according to a difference in a traveling environment in which a bicycle travels, in particular, a change to an environment that requires a higher auxiliary driving force such as an uphill or a muddy road. It can be added to an assist bicycle and can be a driver-friendly electric assist bicycle.

1 is a side view of an electrically assisted bicycle according to an embodiment of the present invention. It is a block diagram which shows the structural example of the electric unit and control circuit system | strain of the electrically assisted bicycle which concern on one Embodiment of this invention. It is a top view which shows the specific example of a switch unit. It is a conceptual diagram showing the driving | running | working environment of an electrically assisted bicycle, and control operation of a control apparatus. It is a flowchart which shows an example of the control action performed by a control apparatus.

FIG. 1 is a side view of an electrically assisted bicycle according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a configuration of an electrically driven unit and a control circuit system of the electrically assisted bicycle.
Referring to FIG. 1, a power-assisted bicycle 10 operates a front wheel 13 via a frame 11, a front fork 12 provided at a front portion of the frame 11, a front wheel 13 attached to the front fork 12, and the front fork 12. Handlebar 14, saddle 15 attached to frame 11, crank 16 and gear unit 17 provided on frame 11, pedal 18 attached to crank 16, rear wheel 19 attached to the rear part of frame 11, etc. It has a basic configuration as a bicycle.

  The electric assist bicycle 10 includes an electric motor 20 disposed on the hub of the front wheel 13. Moreover, it has the battery unit 21 attached to the saddle support part 11a of the flame | frame 11 so that attachment or detachment was possible. Further, a switch unit 30 as a display operation control unit is attached to the handle bar 14. The electric motor 20, the battery unit 21, and the switch unit 30 are electrically connected by connection cords 22, 23 and the like.

The electric unit and the control circuit system will be described with reference to FIG.
The electric motor 20 provided in the hub of the front wheel 13 rotates the front wheel 13 with electric power supplied from the battery unit 21 to generate a driving force. On the downhill or the like, when the rotational speed of the front wheel 13 becomes faster than the rotational speed of the electric motor 20, the electric motor 20 charges the battery unit 21 by regenerative braking.

  The electric assist bicycle 10 includes a control device 31 connected to the electric motor 20 and the battery unit 21. The control device 31 includes an electronic circuit such as a one-chip microcomputer, for example, and executes a control operation described later. Further, the control device 31 includes a memory, and stores a data table (described later) necessary for the control operation in advance. A switch unit 30 is connected to the control device 31. The switch unit 30 is provided with a power switch 32, a mode switch 33, a light lighting switch 34, a battery remaining amount display unit 35, and a mode display unit 36. Yes. The control device 31 is provided in the vicinity of the gear unit 17, but may be located anywhere, in the switch unit 30, in the battery unit 21, or in the vicinity thereof.

FIG. 3 shows an example of a plan view of the switch unit 30.
When the power switch 32 is turned on, an auxiliary driving force can be generated by the electric motor 20. The mode changeover switch 33 is a switch operated by the driver, and is used to set one of the “auto mode”, “power mode”, and “eco charge mode”. In the “auto mode”, when the bicycle runs on its own, such as when going down a hill from normal driving, the electric motor 20 generates a generated current using regenerative braking to charge the battery unit 21. Can do. In the eco-charge mode, the vehicle is traveling in a driving environment with a relatively low load for the driver, such as driving on flat ground with a lower driving force than normal, driving down a gentle downhill, or having a tailwind. If so, regenerative braking is performed and the battery unit 21 is charged. In the power mode, an auxiliary driving force with an increased assist ratio than in the auto mode is generated.

  Referring to FIG. 2, control device 31 further includes a brake detection unit 41, a speed detection unit (traveling speed detection unit) 42, a torque detection unit (torque detection unit) 43, and a rotation speed detection unit (rotation speed detection unit). ) 44 is connected. The brake detection unit 41 includes a sensor provided in a brake system such as a brake lever or a brake pad, for example, and detects whether or not the brake is applied. The speed detector 42 is for detecting the traveling speed of the electrically assisted bicycle 10 by detecting the rotational speed of the front wheel 13 or the rear wheel 19, for example. The torque detector 43 is provided, for example, in the crank 16 and the gear unit 17 and detects torque applied from the pedal 18 to the gear in the gear unit 17 via the crank 16, that is, torque corresponding to the pedaling force by the driver. To do. The rotation speed detector 44, for example, provided in the crank 16, detects the number of rotations of the crank in a predetermined time (unit time), that is, the crank rotation speed.

The specific configurations of the brake detection unit 41, the speed detection unit 42, the torque detection unit 43, and the rotation speed detection unit 44 may have various configurations, and are already known mechanisms. Is omitted.
Referring to FIG. 1, a transmission (not shown) is provided in hub 24 located at the center of rear wheel 19. In the transmission, the gear position is switched by a shift lever (not shown) provided on the handlebar 14. Further, the control device 31 detects an interval at which the pedal 18 is turned by one rotation based on the output of the torque detection unit 43, and is electrically driven while the pedal 18 is turned by one rotation based on the output of the speed detection unit 42. By calculating the rotation speed of the motor 20, the shift stage of the transmission can be automatically determined.

  It is also possible to adopt a configuration in which the control device 31 can detect a gear position by taking in a signal from the speed change lever.

  Next, the effect | action of embodiment of this invention is demonstrated using FIG. FIG. 4 is a conceptual diagram showing the traveling environment of the electrically assisted bicycle 10 and the control operation of the control device 31. In the present invention, when the driver travels requiring higher assistance of the electric motor 20, such as traveling on an uphill or a muddy road, the control device 31 uses the auxiliary driving force of the electric motor 20. The mode is changed. By such an action, the electrically assisted bicycle 10 can apply an appropriate auxiliary driving force according to the traveling environment.

  As shown in the upper part of FIG. 4, the electrically assisted bicycle 10 starts to climb uphill from the flat at the position X. In traveling on flat ground, the mode of the auxiliary driving force of the electric motor 20 is the normal assist mode, and normal assist is applied to the electric assist bicycle 10. The driver's pedaling force (input torque) applied to the pedal 18 and the crank 16 varies according to the rotational position of the crank 16 as shown by a solid line A in FIG. The The auxiliary driving force of the electric motor 20 also varies as indicated by the dotted line B by the control of the control device 31 based on the output of the torque detector 43.

  A broken line C indicates an average value (maximum torque average value) obtained by averaging the peak value (maximum value) taken by the pedaling force of the changing solid line A for each predetermined fluctuation period in a predetermined period. It is calculated by the control device 31 based on the input torque detected every moment. An alternate long and short dash line D indicates an average value (average value of the crank rotational speed) obtained by averaging the rotational speed of the crank 16 over a predetermined period, and the control is based on the crank rotational speed detected by the rotational speed detection unit 44 every moment. Calculated by device 31.

  When the electric assist bicycle 10 starts climbing uphill at the position X, the driver generally depresses the pedal 18 strongly, so that the pedaling force applied to the pedal 18 increases, and as a result, the pedal 18 is connected to the pedal 18. The torque (input torque) applied to the crank 16 also increases (solid line A). Then, the maximum torque average value indicated by the broken line C also starts to increase as indicated by the arrow α.

  On the other hand, when the electrically assisted bicycle 10 begins to climb uphill, the number of revolutions of the crank 16 generally decreases despite the driver depressing the pedal 18 strongly. Therefore, after passing through the position X, the input torque starts to increase (arrow α), but the crank rotational speed starts to decrease, and the average crank rotational speed indicated by the alternate long and short dash line D is also indicated by the arrow β. Begin to decrease.

That is, the control device 31 detects two changes, ie, an increase in torque and a decrease in crank rotation speed. Then, in this embodiment, with an increase rate of the torque to the timing t ₁ and later shown in FIG. 4 reaches or exceeds a predetermined threshold, the reduction rate of the crank rotation speed exceeds a predetermined threshold. That is, not only the torque starts to increase, but also the rate of increase (torque differentiation) exceeds a predetermined threshold. Further, not only the crank rotation speed starts to decrease, but also the reduction rate (differentiation of the crank rotation speed) becomes a predetermined threshold value or more. It is possible to suppress false detection based on factors such as noise by judging the change of the driving environment based on the rate of change such as the rate of increase or decrease, not just the amount of change such as increase or decrease. Become.

  The control device 31 calculates the maximum torque average value from the torque and calculates the crank rotation speed average value from the crank rotation speed. Therefore, the control device 31 can calculate the increase rate of the maximum torque average value and the decrease rate of the crank rotation speed average value. Therefore, in the present embodiment, the control device 31 performs control by regarding the increase rate of the maximum torque average value and the decrease rate of the crank rotation speed average value as the torque increase rate and the rotation speed decrease rate, respectively.

In this timing t _1, the control unit 31, the mode of the auxiliary driving force of the electric motor 20 to transition from the normal assist mode to the elapsed assist mode in flat, the auxiliary driving force of the electric motor 20 is increased as indicated by the dotted line B start. In this example, as shown by the solid line A, the driver approaches the uphill and increases the pedaling force (input torque). Therefore, the control device 31 that detects this increase assists the electric motor 20 as shown by the dotted line B. A control command is issued to start increasing the driving force.
This transition is performed in the detection period shown in FIG. 4, which means a period during which a change in the driving environment is detected, and an elapsed period from the normal assist mode on flat ground to the high assist mode described below. Also means. Therefore, the mode in this detection period is called a progress assist mode.

  In the elapsed assist mode, the control device 31 does not necessarily increase the auxiliary driving force of the electric motor 20 as indicated by the dotted line B in FIG. 4, and the auxiliary driving force is normally assisted until the next high assist mode. The value in the mode may be maintained. Therefore, in the control of the control device 31 in the elapsed assist mode, 1) the auxiliary driving force of the electric motor 20 is not changed from the normal assist mode, and 2) the auxiliary driving force of the electric motor 20 starts to increase from the normal assist mode. There can be either control.

Time length of the detection period is a period from the timing t ₁ to timing t _2, its length is arbitrary. The timing t ₂ later, i.e., after a detection period, the control unit 31 shifts the mode of the auxiliary driving force of the electric motor 20 from the elapsed assist mode to the high assist mode. At the timing t _2, the assist to climb uphill in the original meaning begin to activate. Time length of high assist mode is a period from the timing t ₂ to time t _3, the period is referred to as the boost period. In the case of 1), after entering the boost period (after timing t ₂ ), the control device 31 increases the auxiliary driving force of the electric motor 20.

For the 2), the control unit 31 at the timing t ₁ and later, the auxiliary driving force of the normal assist mode, the predetermined amount (first increment) only, be increased to the auxiliary driving force of the elapsed assist mode it can. Further, the control unit 31 at the timing t ₂ later, the auxiliary driving force of the elapsed assist mode, a predetermined amount (the second increment) only, can be increased to assist the driving force of high assist mode.

Also, in the case of 2) above, the controller 31 at the timing t ₁ and later, an assist ratio of the normal assist mode, the predetermined amount (first increment) only be increased to assist the ratio of elapsed assist mode it can. Further, the control unit 31 at the timing t ₂ later, an assist ratio of the elapsed assist mode, a predetermined amount (the second increment) only, can be increased to assist the ratio of high assist mode. Here, “assist ratio” means the ratio of the auxiliary driving force of the electric motor 20 to the torque corresponding to the pedaling force.

Also, in the case of 2) above, the controller 31 at the timing t ₁ and later, the peak value of the auxiliary driving force to take every predetermined fluctuation period of the normal assist mode, the predetermined amount (first increment) by, The peak value of the progress assist mode can be increased. Further, the control unit 31 at the timing t ₂ later, the peak value of the auxiliary driving force to take every predetermined fluctuation period of the normal course assist mode, a predetermined amount (the second increment) only, the peak of high assist mode Can be increased to a value.

  When the assist torque value increases in response to the pedal depressing as in the prior art described in Patent Document 1, it is considered that the auxiliary driving force always increases in response to the pedal depressing. . According to such control, even when the driver steps on the pedal again in a traveling environment such as a flat ground, the auxiliary driving force increases. However, such control may cause the driver to feel an unnatural driving feeling or cause danger in some cases. In other words, it can be said that there is a possibility of erroneously detecting changes in the driving environment.

  In the present invention, the control device 31 adopts a configuration in which a change in the travel environment is detected based on the change rate of the torque and the crank rotation speed, so that erroneous detection of the change in the travel environment can be suppressed. A suitable auxiliary driving force can be applied to the electrically assisted bicycle 10.

  FIG. 5 is a flowchart illustrating an example of a control operation performed by the control device 31. After the driver rides on the electrically assisted bicycle 10 and turns on the power switch 32, the driver steps on the pedal 18. Then, the torque applied to the gear unit 17 via the crank 16 is detected by the torque detection unit 43 provided in the gear unit 17 and applied to the control device 31. That is, the input torque is detected (step S1). Further, the rotational speed detection unit 44 detects the rotational speed of the crank 16 and provides it to the control device 31 (step S2). At this stage, the mode of the auxiliary driving force of the electric motor 20 is the normal assist mode.

  Then, the control device 31 determines whether or not the increase rate (change rate) of the torque (input torque) detected by the torque detection unit 43 is equal to or higher than a predetermined threshold, and is detected by the rotation speed detection unit 44. It is determined whether or not the reduction rate (change rate) of the rotation speed of the crank 16 has reached a predetermined threshold value (step S3). In this embodiment, as shown in FIG. 4, the determination is made using the maximum torque average value and the crank rotation speed average value. If the rate of change of these values (the increase rate of the maximum average torque value and the decrease rate of the average crank speed) is not equal to or greater than the predetermined threshold value, the process returns to step S1, and the control device 31 The detection of the rotational speed is continued (step S3; No).

  When the rate of increase in torque and the rate of decrease in the number of rotations of the crank 16 exceed a predetermined threshold (step S3; Yes), the control device 31 changes the auxiliary drive force mode of the electric motor 20 from the normal assist mode to the elapsed assist. The mode is changed (step S4). Here, the control device 31 determines whether or not the transition to the elapsed assist mode is due to so-called erroneous detection (step S5). The detection of steps S1 and S2 (the increase rate of the torque has exceeded a predetermined threshold and the decrease rate of the rotational speed has exceeded the predetermined threshold) may be erroneously determined due to noise detection or the like. Because there is. As a specific method of erroneous detection, there is a method in which a noise pattern that is likely to be determined as Yes in step S3 is stored as a template, and is determined as erroneous detection when a change pattern of torque or crank rotational speed matches the template. is there. However, the determination method of erroneous detection is not particularly limited.

  When the erroneous detection is determined (step S5; Yes), the control device 31 immediately returns to the normal assist mode (step S10). When the determination of erroneous detection is not made (step S5;; No), the control device 31 determines whether or not a predetermined time (the detection period in FIG. 4) has elapsed after the transition to the elapsed assist mode (step S6). .

  The elapsed assist mode continues until the predetermined time elapses (step S6; No), but after the predetermined time elapses (step S6; Yes), the control device 31 changes the mode of the auxiliary driving force of the electric motor 20 to The transition assist mode is changed to the high assist mode (step S7). Here, similarly to step S5, the control device 31 again determines whether or not the transition to the high assist mode is due to erroneous detection (step S8), and when the erroneous detection is determined (step S8; Yes). ), The control device 31 immediately returns to the normal assist mode (step S10). When the determination of erroneous detection is not made (step S8;; No), the control device 31 determines whether or not a predetermined time (boost period in FIG. 4) has elapsed after the transition to the high assist mode (step S9). .

  The high assist mode continues until the predetermined time elapses (step S9; No), but after the predetermined time elapses (step S9; Yes), the control device 31 changes the mode of the auxiliary driving force of the electric motor 20 to A transition is made from the high assist mode to the normal assist mode (step S10). This completes a series of controls.

After the end of the boost period (timing t ₃ ), in the example of FIG. 4, the auxiliary driving force is lowered to the same value as the detection period (auxiliary driving force in the elapsed assist mode), and then shifts to the normal assist mode. Yes. However, the mode change mode of the electric motor 20 after the boost period ends is not particularly limited. The control device 31 may directly change the auxiliary driving force mode of the electric motor 20 from the high assist mode to the normal assist mode.

  Further, even within the period of the elapsed assist mode in step S4 and the high assist mode in step S5, the pedaling force (input torque) by the driver is reduced to a predetermined threshold or more due to a sudden change in the driving situation, and the crank There may be a case where an event in which the rate of decrease in the rotational speed is equal to or greater than a predetermined threshold is detected. This event is an event opposite to the progress assist mode in FIG. 4, and a rate of change opposite to that in step S3 can be detected. When such an event is detected over a certain amount (for example, a certain time), the control device 31 may immediately return to the normal assist mode. For example, in step S5 and step S8, the control device 31 can determine whether or not the rate of change opposite to that in step S3 is equal to or greater than a predetermined threshold, in addition to the normal erroneous detection determination.

The time length of the detection period is a period from timing t ₁ to timing t ₂ , but the length is not particularly limited. As shown in FIG. 4, the time length of the detection period may be the period from the timing t ₁ to timing t _4. If the period from the timing t ₁ to timing t _4, upon detecting an input torque of approximately one period in the fluctuation period, since the mode of the auxiliary driving force of the electric motor 20 is changed to the high assist mode, erroneous detection Can be further suppressed. Further, the time length of the boost period is a period from timing t ₂ (or t ₄ ) to timing t ₃ , and generally a legally defined value (for example, legal upper limit value) is used. There is no limitation.

  In the embodiment shown in FIGS. 4 and 5, the control device 31 calculates the maximum torque average value and the crank rotation speed average value, and compares the rate of change of these values with a predetermined threshold value. However, the control device 31 does not necessarily calculate the maximum torque average value and the crank rotation speed average value. For example, the control can be performed using the torque increase rate (change rate) and the crank rotation rate decrease rate (change rate) obtained at a predetermined timing as they are.

In the embodiment shown in FIGS. 4 and 5, the control device 31 changes the mode of the auxiliary driving force of the electric motor 20 in the order of normal assist mode → elapsed assist mode → high assist mode → normal assist mode. ing. However, the mode transition of the present invention is not limited to such a form. For example, the control device 31 may change the auxiliary driving force mode of the electric motor 20 from the normal assist mode directly to the high assist mode. That is, in FIG. 4, after the elapse of timing t ₁ , the control device 31 can also change the auxiliary driving force mode of the electric motor 20 from the normal assist mode directly to the high assist mode. In this case, the auxiliary driving force mode of the electric motor 20 includes only the normal assist mode and the high assist mode.

  As described with reference to FIG. 1, the electrically assisted bicycle 10 of the present invention is configured to apply the auxiliary driving force to the front wheels 13, but is not limited thereto, and may be configured to apply the auxiliary driving force to the rear wheels 19. . Further, although the rear wheel 19 is provided with a transmission, a bicycle without a transmission may be used. When the transmission is eliminated, the shift stage is not taken into consideration, and it is only necessary to determine whether the driving environment load is large, medium, or small.

  In the embodiment of FIG. 4, the example of climbing uphill has been described for changes in the travel environment. However, the scene in which the present invention is provided is not limited to when entering an uphill, and the driver needs more auxiliary driving force than a conventional road, such as when entering a muddy road or gravel road. It is widely applicable to the scene.

The present invention is not limited to the embodiment described above, and various modifications can be made within the scope of the claims.
The present invention is applicable to an electrically assisted bicycle that applies an auxiliary driving force in accordance with a traveling environment load such as an uphill or a muddy road.

10 Electric Assist Bicycle 13 Front Wheel 16 Crank 18 Pedal 20 Electric Motor (Power Drive System)
21 battery unit 31 control device (running environment load detection means, assist ratio setting means, control unit)
42 Speed detection unit (travel speed detection unit)
43 Torque detection unit (torque detection unit)
44 Rotational speed detection unit (Rotational speed detection unit)

Claims (7)

An electrically assisted bicycle,
A pedal to which human treading force is applied,
A crank connected to the pedal and to which a torque corresponding to the pedal effort is applied;
A torque detection unit for detecting the torque;
A rotational speed detection unit for detecting the rotational speed of the crank;
An electric motor for generating auxiliary driving force;
A control device for controlling the auxiliary driving force of the electric motor,
The control device sets the mode of the auxiliary driving force of the electric motor to a normal assist mode after the timing when the increase rate of the torque becomes equal to or higher than a predetermined threshold and the decrease rate of the rotation speed becomes equal to or higher than a predetermined threshold. Electric assist bicycle that shifts from high to low assist mode. The electrically assisted bicycle according to claim 1,
The control device increases the value of the auxiliary driving force after the timing. The electrically assisted bicycle according to claim 1,
The said control apparatus is an electrically assisted bicycle which increases the assist ratio which is the ratio of the said auxiliary drive force with respect to the torque corresponding to the said pedal effort after the said timing. The electrically assisted bicycle according to claim 1,
The said control apparatus is an electrically assisted bicycle which increases the peak value of the said auxiliary drive force taken for every predetermined fluctuation period after the said timing. The electrically assisted bicycle according to claim 1,
The said control apparatus is an electric assist bicycle which changes the mode of the auxiliary drive force of the said electric motor from the said normal assist mode to the said high assist mode after the predetermined detection period passes after the said timing. The electrically assisted bicycle according to claim 1,
The control device determines whether the increase rate of the torque is equal to or greater than a predetermined threshold value and that the decrease rate of the rotation speed is equal to or greater than a predetermined threshold value due to erroneous detection. Electric assist bicycle. The electrically assisted bicycle according to claim 1,
The controller shifts the auxiliary driving force mode of the electric motor from the normal assist mode to the elapsed assist mode in a predetermined detection period after the timing, and after the detection period elapses, the auxiliary driving of the electric motor An electrically assisted bicycle that changes a power mode from the elapsed assist mode to the high assist mode.

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