JP2024150061A - Angular velocity control of electric-assisted bicycles - Google Patents

Abstract

To provide a power-assisted bicycle capable of enhancing the attraction of the power-assisted bicycle serving as a tool for a hobby or sport, by giving values other than assisting drive power.SOLUTION: A power-assisted bicycle includes a regenerative control section (yaw angular velocity) which, when the roll angle of the power-assisted bicycle is A or more, controls regenerative torque (traction of a rear tire) of a motor on the basis of the roll angle and yaw angular velocity of the power-assisted bicycle.SELECTED DRAWING: Figure 1

Description

This invention provides technology for controlling the angular yaw velocity of electrically assisted bicycles that use fixed gears and electrically assisted bicycles that have a motor built into the rear hub.

Patent Document 1 discloses a technology for detecting a downward gradient and performing regenerative control, Patent Document 2 discloses a technology for controlling a motor using acceleration and angular velocity acquired by a six-axis sensor, and Patent Document 3 discloses a technology for controlling transmission torque with a clutch installed in the rear hub.

JP2013-209077Publication JP2019-116241Publication JP2021-136814Publication

Fixed gear bikes, which use a fixed gear on the rear hub and have a direct connection between the rotation of the rear tire and the crank, have a technique called "skid" where the weight is removed from the rear tire and the rider's legs are used to hold down the crank from turning counterclockwise, allowing the rear tire to slide. Also, mountain bikes, which run on rough unpaved roads, have a technique called "cutties", where the rear tire can slide without using the rear brake by applying weight to the rear tire via the crank (pedal).

By controlling the regenerative torque of the motor according to the roll angle and yaw angular velocity of the electric assist bicycle, the braking force of the rear tire is electronically controlled, providing more value to the electric assist bicycle than simply assisting with the driving force.

In order to achieve the above object, the electrically assisted bicycle (fixed gear) of the present invention comprises a fixed gear on a rear hub, a motor mechanically connected to the crank and the rear tire, a rotation direction detection unit that detects whether the crank is rotating clockwise or counterclockwise, a torque detection unit that detects the torque applied to the crank by the rider, an assist control unit that determines the torque to be assisted by the motor from the torque detected by the torque detection unit, an angular velocity detection unit that detects the yaw angular velocity and roll angular velocity of the electrically assisted bicycle (fixed gear), a roll angle calculation unit that calculates the roll angle of the electrically assisted bicycle (fixed gear) from the roll angular velocity detected by the angular velocity detection unit, and an assist control unit that calculates the roll angle of the electrically assisted bicycle (fixed gear) based on the torque detected by the torque detection unit. The regenerative control unit (torque) determines the regenerative torque of the motor, and when the rotation direction detection unit detects that the crank is rotating clockwise, the assist control unit determines the torque to be assisted by the motor based on the torque detected by the torque detection unit, and when the rotation direction of the crank detected by the rotation direction detection unit is counterclockwise and the roll angle calculated by the roll angle calculation unit is A or less, the regenerative torque of the motor is determined based on the regenerative control unit (torque), and when the angular velocity detection unit detects a yaw angular velocity of B or more while the motor is being controlled based on the regenerative control unit (torque), the regenerative torque of the motor is weakened so that the yaw angular velocity becomes B or less.

The electrically assisted bicycle (fixed gear) is equipped with a regeneration control unit (angular yaw velocity) that determines the regeneration torque of the motor based on the angular velocity of yaw detected by the angular velocity detection unit and the roll angle calculated by the roll angle calculation unit, and when the rotation direction of the crank detected by the rotation direction detection unit is counterclockwise and the roll angle calculated by the roll angle calculation unit is A or greater, the regeneration torque of the motor is determined based on the regeneration control unit (angular yaw velocity).

The electrically assisted bicycle (fixed gear) is equipped with a vehicle speed detection unit that detects the vehicle speed of the electrically assisted bicycle (fixed gear) and a clutch that controls the transmission torque in the rear hub, and when the vehicle speed detected by the vehicle speed detection unit is equal to or lower than C, the clutch is released.

The electrically assisted bicycle (fixed gear) releases the clutch when the vehicle speed detected by the vehicle speed detection unit is equal to or higher than C and the torque detected by the torque detection unit is equal to or lower than a threshold value D.

When the vehicle speed detected by the vehicle speed detection unit is C or higher, the torque detected by the torque detection unit is D or higher, and the rotation direction detection unit detects that the crank is rotating counterclockwise, the electrically assisted bicycle (fixed gear) controls the clutch to reduce the transmitted torque so that the crank comes to a standstill.

The electrically assisted bicycle (fixed gear) engages the clutch when the vehicle speed detected by the vehicle speed detection unit is C or higher, the torque detected by the torque detection unit is D or higher, and the rotation direction detection unit detects that the crank is rotating clockwise.

The electrically assisted bicycle (fixed gear) is equipped with a rear brake lever sensor that detects the force applied by the rider to the rear brake lever, and when the rotation direction detection unit detects that the crank is rotating counterclockwise, the roll angle calculated by the roll angle calculation unit is A or less, and the value detected by the rear brake lever sensor is E or less, the clutch is released.

The electrically assisted bicycle (fixed gear) is equipped with a regenerative control unit (rear brake) that determines the regenerative torque of the motor based on the value detected by the rear brake lever sensor, and when the rotation direction detection unit detects that the crank is rotating counterclockwise, and the roll angle calculated by the roll angle calculation unit is A or less, and the value detected by the rear brake lever sensor is E or greater, the clutch is engaged and the regenerative torque of the motor is controlled based on the regenerative control unit (rear brake), and when the angular velocity detection unit detects a yaw angular velocity of B or greater while the motor is being controlled based on the regenerative control unit (rear brake), the regenerative torque of the motor is weakened so that the yaw angular velocity becomes B or less.

When the rotation direction detection unit detects that the crank is rotating counterclockwise and the roll angle calculated by the roll angle calculation unit is equal to or greater than A, the electrically assisted bicycle (fixed gear) engages the clutch and determines the regenerative torque of the motor according to the regenerative control unit (yaw angular velocity).

The electrically assisted bicycle (hub motor) is equipped with a free hub on the rear hub, a motor inside the rear hub, an angular velocity detection unit that detects the angular velocity of roll and yaw of the electrically assisted bicycle (hub motor), a roll angle calculation unit that calculates the roll angle of the electrically assisted bicycle (hub motor) from the angular velocity of roll detected by the angular velocity detection unit, a rear brake lever sensor that detects the force applied to the rear brake lever by the rider, and a regeneration control unit (rear brake) that determines the regeneration torque of the motor based on the value detected by the rear brake lever sensor. If the roll angle calculated by the roll angle calculation unit is A or less, the regeneration torque of the motor is determined based on the regeneration control unit (rear brake), and if the angular velocity detection unit detects a yaw angular velocity of B or greater while the motor is being controlled based on the regeneration control unit (rear brake), the regeneration torque of the motor is weakened so that the yaw angular velocity becomes B or less.

The electrically assisted bicycle (hub motor) is equipped with a regeneration control unit (angular yaw velocity) that determines the regeneration torque of the motor based on the roll angle calculated by the roll angle calculation unit and the angular velocity of yaw detected by the angular velocity detection unit, and when the roll angle calculated by the roll angle calculation unit is A or greater, the regeneration torque of the motor is determined based on the regeneration control unit (angular yaw velocity).

The angular velocity control of an electrically assisted bicycle according to the present invention makes it possible to optimally control the turning speed of electrically assisted bicycles that use fixed gears and electrically assisted bicycles that have a motor built into the rear hub.

1 is a diagram illustrating the schematic configuration of an electrically assisted bicycle employing a fixed gear according to an embodiment of the present invention. FIG. 4 is a diagram for explaining an example of a regenerative control unit (torque) according to an embodiment of the present invention. FIG. 4 is a diagram illustrating an example of a regenerative control unit (angular velocity of yaw) according to an embodiment of the present invention. FIG. 4 is a diagram illustrating an example of a regenerative control unit (rear brake) according to an embodiment of the present invention. 1 is a diagram illustrating an example of control of an electrically assisted bicycle employing a fixed gear according to an embodiment of the present invention. 1 is a diagram illustrating an example of control of an electrically assisted bicycle employing a fixed gear according to an embodiment of the present invention. 1 is a diagram illustrating an example of control of an electrically assisted bicycle employing a fixed gear according to an embodiment of the present invention. 1 is a diagram illustrating the schematic configuration of an electrically assisted bicycle having a motor built into the rear hub according to an embodiment of the present invention. FIG. 13 is a diagram for explaining an example of control of an electrically assisted bicycle having a motor built into the rear hub according to an embodiment of the present invention.

Below, an embodiment of the angular velocity control of an electrically assisted bicycle using a fixed gear according to the present invention will be explained with reference to the drawings.

Figure 1 is a diagram explaining the general configuration of an electrically assisted bicycle that uses a fixed gear.

The electrically assisted bicycle 100 employs a fixed gear and includes an electrically assisted bicycle (fixed gear) 1, a fixed gear 2, a motor 3, a rotation direction detection unit 4, a torque detection unit 5, an assist control unit 6, an angular velocity detection unit 7, a roll angle calculation unit 8, a regeneration control unit (torque) 9, a regeneration control unit (angular yaw velocity) 10, a vehicle speed detection unit 11, a clutch 12, a rear brake lever sensor 13, and a regeneration control unit (rear brake) 14.

In electrically assisted bicycles that use a fixed gear in the rear hub and where the crank and rear tire are always directly connected, the situations in which the motor performs regenerative control and generates a braking force on the rear tire can be classified as follows: when the vehicle is upright on the ground, the crank rotates counterclockwise and the rider applies force to the crank, and when the vehicle is not upright on the ground, the crank rotates counterclockwise and the rider applies force to the crank.

Since two-wheeled vehicles turn by self-steering (the handlebars turn according to the inclination of the vehicle), it is not desirable for the vehicle to turn at a speed greater than a certain level (yaw angular velocity greater than B) while the vehicle is upright (roll angle A or less).

For this reason, the electrically assisted bicycle (fixed gear) 1 comprises a fixed gear 2 attached to the rear hub, a motor 3 mechanically connected to the crank and rear tire, a rotation direction detection unit 4 that detects whether the rotation direction of the crank is clockwise or counterclockwise, a torque detection unit 5 that detects the torque applied to the crank by the rider, an assist control unit 6 that determines the torque to be assisted by the motor 3 from the torque detected by the torque detection unit 5, an angular velocity detection unit 7 that detects the yaw angular velocity and roll angular velocity of the electrically assisted bicycle (fixed gear) 1, a roll angle calculation unit 8 that calculates the roll angle of the electrically assisted bicycle (fixed gear) 1 from the roll angular velocity detected by the angular velocity detection unit 7, and a roll angle calculation unit 9 that calculates the roll angle of the electrically assisted bicycle (fixed gear) 1 based on the torque detected by the torque detection unit 5. It is equipped with a regenerative control unit (torque) 9 that determines the regenerative torque of the motor 3, and when the rotation direction detection unit 4 detects that the crank is rotating clockwise, the assist control unit 6 determines the torque to be assisted by the motor 3 based on the torque detected by the torque detection unit 5, and when the rotation direction of the crank detected by the rotation direction detection unit 4 is counterclockwise and the roll angle calculated by the roll angle calculation unit 8 is A or less, the regenerative torque of the motor 3 is determined based on the regenerative control unit (torque) 9, and when the angular velocity detection unit 7 detects a yaw angular velocity of B or more while controlling the motor 3 based on the regenerative control unit (torque) 9, the regenerative torque of the motor 3 is weakened so that the yaw angular velocity becomes B or less.

When the vehicle is tilted (roll angle is A or more), it is preferable to control the vehicle's yaw angular velocity according to the roll angle, so the electrically assisted bicycle (fixed gear) 1 is equipped with a regeneration control unit (yaw angular velocity) 10 that determines the regenerative torque of the motor based on the yaw angular velocity detected by the angular velocity detection unit 7 and the roll angle calculated by the roll angle calculation unit 8, and when the rotation direction of the crank detected by the rotation direction detection unit 4 is counterclockwise and the roll angle calculated by the roll angle calculation unit 8 is A or more, the regenerative torque of the motor 3 is determined based on the regeneration control unit (yaw angular velocity) 10.

If an electrically assisted bicycle (fixed gear) 1 is used in a bicycle race, and the torque detected by the torque detection unit 5 and the torque assisted by the motor 3 are electronically acquired and published on an electronic bulletin board in the venue or via a web service, it will become difficult to fix the race.

It is difficult to ride at extremely low speeds (when the vehicle speed is C or less) if the crank and rear tire are directly connected, so the electrically assisted bicycle (fixed gear) 1 is equipped with a vehicle speed detection unit 11 that detects the vehicle speed of the electrically assisted bicycle (fixed gear) 1, and a clutch 12 that controls the transmission torque inside the rear hub, and when the vehicle speed detected by the vehicle speed detection unit 11 is C or less, the clutch 12 is released.

Even if the vehicle speed is above a certain level (vehicle speed is C or higher), if the rear tire is not on the ground or the rider's feet are off the pedals (torque applied to the crank is D or lower), it is easier to ride if the crank and rear tire are not connected, so the electrically assisted bicycle (fixed gear) 1 releases the clutch 12 when the vehicle speed detected by the vehicle speed detection unit 11 is C or higher and the torque detected by the torque detection unit 5 is D or lower.

When the vehicle speed is above a certain level (vehicle speed is C or higher), and the rider applies torque to the crank after the crank has rotated counterclockwise, the regenerative torque (braking force of the rear tire) of motor 3 is determined based on regenerative control unit (torque) 9 and regenerative control unit (yaw angular velocity) 10. If the regenerative torque of motor 3 is not large enough at this time, the crank will move counterclockwise.

Whether the regenerative torque of the motor 3 can be made sufficiently large depends on the grip of the rear tire, but the grip of the rear tire is determined by several factors such as the rider's weight and riding posture, the slope of the road surface and the dynamic friction resistance coefficient, the tire brand and air pressure, etc., so if the regenerative torque of the motor 3 cannot be made sufficiently large and the crank rotates counterclockwise, the torque transmitted by the clutch 12 must be reduced. Therefore, when the vehicle speed detected by the vehicle speed detection unit 11 is C or higher, the torque detected by the torque detection unit 5 is D or higher, and the rotation direction detection unit 4 detects that the crank is rotating counterclockwise, the electric assisted bicycle (fixed gear) 1 controls the clutch 12 to reduce the transmitted torque so that the crank stops.

When the vehicle speed is above a certain level (vehicle speed is C or higher), the rider's feet are on the pedals and the rear tire is on the ground (torque applied to the crank is D or higher), and the crank is rotating clockwise, there is no need to control the transmitted torque with the clutch 12. Therefore, the electrically assisted bicycle (fixed gear) 1 engages the clutch 12 when the vehicle speed detected by the vehicle speed detection unit 11 is C or higher, the torque detected by the torque detection unit 5 is D or higher, and the rotation direction detection unit 4 detects that the crank is rotating clockwise.

If the clutch control during regeneration is controlled by the force with which the rider pulls the rear brake lever, rather than the torque applied to the crank, this method of operation is closer to that of a conventional bicycle. Therefore, the electrically assisted bicycle (fixed gear) 1 is equipped with a rear brake lever sensor 13 that detects the force applied to the rear brake lever by the rider, and releases the clutch 12 when the rotation direction detection unit 4 detects that the crank is rotating counterclockwise, the roll angle calculated by the roll angle calculation unit 8 is equal to or less than A, and the value detected by the rear brake lever sensor 13 is equal to or less than E.

Even when the regenerative control of the electrically assisted bicycle 1 is controlled by the force of pulling the rear brake lever, it is undesirable for the vehicle to turn at a certain speed or more (the angular velocity of the yaw is B or more) when the vehicle is upright (roll angle is A or less), so the electrically assisted bicycle (fixed gear) 1 is equipped with a regenerative control unit (rear brake) 14 that determines the regenerative torque of the motor 3 based on the value detected by the rear brake lever sensor 13, and when the rotation direction detection unit 4 detects that the crank is rotating counterclockwise, and the roll angle of the vehicle calculated by the roll angle calculation unit 8 is A or less, and the value detected by the rear brake lever sensor 13 is E or more, the clutch 12 is engaged and the regenerative torque of the motor 3 is controlled based on the regenerative control unit (rear brake) 14, and when the angular velocity detection unit 7 detects a yaw angular velocity of B or more while the motor 3 is being controlled based on the regenerative control unit (rear brake) 14, the regenerative torque of the motor 3 is weakened so that the angular velocity of the yaw is B or less.

Even when the regenerative control of the motor 3 is controlled by the force applied to pull the rear brake lever, it is preferable to control the angular velocity of the vehicle's yaw according to the roll angle when the vehicle is tilted (roll angle is A or more). Therefore, when the rotation direction detection unit 4 detects that the crank is rotating counterclockwise and the roll angle of the vehicle calculated by the roll angle calculation unit 8 is A or more, the electric assisted bicycle (fixed gear) 1 engages the clutch 12 and determines the regenerative torque of the motor 3 according to the regenerative control unit (angular velocity of yaw) 14.

Controlling the turning speed of a two-wheeled vehicle with the steering angle of the handlebars is limited to extremely low speeds. If the regenerative torque of the motor were determined by the steering angle of the handlebars, it would encourage the rider to try to turn the vehicle by steering the handlebars, but turning the handlebars too much while traveling above a certain speed could cause the front tires to slip and the vehicle to fall over, so it is not envisaged to use the steering angle of the handlebars to control the regeneration of the motor 3.

Figure 2 is a diagram illustrating an example of a regenerative control unit (torque) according to an embodiment of the present invention.

The regenerative control unit (torque) 9 of the electrically assisted bicycle (fixed gear) 1 determines the relationship between the torque detected by the torque detection unit 5 and the regenerative torque of the motor 3. Since the grip of the rear tire differs depending on the rider's weight and riding posture, the slope of the road surface and the dynamic friction resistance coefficient, the tire brand and air pressure, etc., as described above, when the angular velocity detection unit 7 detects a yaw angular velocity of B or greater while the motor 3 is being controlled based on the regenerative control unit (torque) 9, control is performed to weaken the regenerative torque of the motor 3 so that the yaw angular velocity becomes B or less.

Figure 3 is a diagram illustrating an example of a regenerative control unit (yaw angular velocity) according to an embodiment of the present invention.

The regenerative control unit (yaw angular velocity) 10 of the electrically assisted bicycle (fixed gear) 1 determines the yaw angular velocity according to the roll angle calculated by the roll angle calculation unit 8, and controls the regenerative torque of the motor (braking force of the rear tire) so that the yaw angular velocity detected by the angular velocity detection unit 7 becomes the value determined by the regenerative control unit (yaw angular velocity) 10.

By increasing the allowable yaw angular velocity for the roll angle calculated by the roll angle calculation unit 8, the turning ability will be improved, and by decreasing the allowable yaw angular velocity for the roll angle, the stability will be improved. Conventionally, the turning ability of a vehicle was determined by the dimensions of the frame and parts, but this makes it possible to electronically control the turning ability of the vehicle.

Figure 4 is a diagram illustrating an example of a regenerative control unit (rear brake) according to an embodiment of the present invention.

The regenerative control unit (rear brake) 14 of the electrically assisted bicycle 1 determines the relationship between the force detected by the rear brake lever sensor 13 and the regenerative torque of the motor 3. Since the grip of the rear tire varies depending on the rider's weight and riding posture, the slope of the road and the coefficient of dynamic friction resistance, the tire brand and air pressure, etc., if the angular velocity detection unit 7 detects a yaw angular velocity of B or greater while the motor 3 is being controlled based on the regenerative control unit (rear brake) 14 as described above, control is performed to weaken the regenerative torque of the motor 3 so that the yaw angular velocity becomes B or less.

Figures 5, 6, and 7 are diagrams illustrating an example of control of an electrically assisted bicycle that employs a fixed gear according to an embodiment of the present invention.

Steps S1 to S7 describe motor control based on the torque applied to the crank of a fixed-gear electrically assisted bicycle, steps S8 to S14 describe clutch control of a fixed-gear electrically assisted bicycle equipped with a clutch in the rear hub that controls the transmitted torque, and steps S15 to S23 describe an example of clutch and motor control of a fixed-gear electrically assisted bicycle equipped with a clutch in the rear hub that controls the transmitted torque and a rear brake lever sensor that detects the force applied to the rear brake lever.

In step S1, if the rotation direction detector 4 detects that the crank is rotating clockwise, the process proceeds to step S2, and if the rotation direction detector 4 detects that the crank is rotating counterclockwise, the process proceeds to step S3.

In step S2, the assist control unit 6 determines the torque to be assisted by the motor 3 based on the torque applied to the crank by the rider detected by the torque detection unit 5.

In step S3, if the roll angle of the electrically assisted bicycle (fixed gear) 1 calculated by the roll angle calculation unit 8 is equal to or less than A, the process proceeds to step S4, and if the roll angle calculated by the roll angle calculation unit is equal to or greater than A, the process proceeds to step S7.

In step S4, the regenerative control unit (torque) 9 determines the regenerative torque of the motor 3 based on the torque applied to the crank by the rider detected by the torque detection unit 5.

In step S5, if the angular velocity of the yaw of the electrically assisted bicycle (fixed gear) 1 detected by the angular velocity detection unit 7 is equal to or greater than B, the process proceeds to step S6. If the angular velocity of the yaw of the electrically assisted bicycle (fixed gear) 1 detected by the angular velocity detection unit 7 is equal to or less than B, the process proceeds to step S4.

In step S6, the regenerative torque of the motor 3 is weakened so that the yaw angular velocity of the electrically assisted bicycle (fixed gear) 1 detected by the angular velocity detection unit 7 becomes equal to or less than B.

In step S7, the regeneration control unit (yaw angular velocity) 10 determines the regeneration torque of the motor 3 based on the yaw angular velocity of the electrically assisted bicycle (fixed gear) 1 detected by the angular velocity detection unit 7 and the roll angle of the electrically assisted bicycle 1 (fixed gear) calculated by the roll angle calculation unit 8.

In step S8, if the vehicle speed of the electrically assisted bicycle (fixed gear) 1 detected by the vehicle speed detection unit 11 is equal to or lower than C, the process proceeds to step S9, and if the vehicle speed of the electrically assisted bicycle (fixed gear) 1 detected by the vehicle speed detection unit 11 is equal to or higher than C, the process proceeds to step S10.

In step S9, the clutch 12 is released.

In step S10, if the torque applied to the crank detected by the torque detection unit 5 is equal to or less than D, the process proceeds to step S11, and if the torque applied to the crank detected by the torque detection unit 5 is equal to or greater than D, the process proceeds to step S12.

In step S11, the clutch 12 is released.

In step S12, if the rotation direction of the crank detected by the rotation direction detection unit 4 is counterclockwise, the process proceeds to step S13, and if the rotation direction of the crank detected by the rotation direction detection unit 4 is clockwise, the process proceeds to step S14.

In step S13, the clutch 12 is controlled to reduce the transmitted torque so that the crank is stationary, and in step S14, the clutch 12 is engaged.

In step S15, if the rotation direction of the crank detected by the rotation direction detection unit 4 is clockwise, the process proceeds to step S16, and if the rotation direction of the crank detected by the rotation direction detection unit 4 is counterclockwise, the process proceeds to step S17.

In step S16, the clutch 12 is engaged, and the assist control unit 6 determines the torque to be assisted by the motor 3 based on the torque applied to the crank detected by the torque detection unit 5.

In step S17, if the roll angle of the electrically assisted bicycle (fixed gear) 1 calculated by the roll angle calculation unit 8 is A or less, the process proceeds to step S18, and if the roll angle of the electrically assisted bicycle (fixed gear) 1 calculated by the roll angle calculation unit 8 is A or more, the process proceeds to step S23.

In step S18, if the pulling force of the rear brake lever detected by the rear brake lever sensor 13 is equal to or less than E, the process proceeds to step S19, and if the pulling force of the rear brake lever detected by the rear brake lever sensor 13 is equal to or greater than E, the process proceeds to step S20.

In step S19, the clutch 12 is released.

In step S20, the clutch 12 is engaged, and the regenerative control unit (rear brake) 14 determines the regenerative torque of the motor 3 based on the force applied to the rear brake lever detected by the rear brake lever sensor 13.

In step S21, if the angular velocity of the yaw of the electrically assisted bicycle (fixed gear) 1 detected by the angular velocity detection unit 7 is equal to or greater than B, the process proceeds to step S22, and if the angular velocity of the yaw of the electrically assisted bicycle (fixed gear) 1 detected by the angular velocity detection unit 7 is equal to or less than B, the process proceeds to step S20.

In step S22, the regenerative torque of the motor 3 is weakened so that the yaw angular velocity of the electrically assisted bicycle (fixed gear) 1 becomes equal to or less than B.

In step S23, the clutch 12 is engaged, and the regeneration control unit (yaw angular velocity) 10 determines the regeneration torque of the motor 3 based on the yaw angular velocity of the electrically assisted bicycle (fixed gear) 1 detected by the angular velocity detection unit 7 and the roll angle of the electrically assisted bicycle (fixed gear) 1 calculated by the roll angle calculation unit 8.

Figure 8 is a diagram explaining the general configuration of an electrically assisted bicycle with a motor built into the rear hub.

The electrically assisted bicycle 200, which has a motor built into the rear hub, includes an electrically assisted bicycle (hub motor) 1, a free hub 2, a motor 3, an angular velocity detection unit 4, a roll angle calculation unit 5, a rear brake lever sensor 6, a regeneration control unit (rear brake) 7, and a regeneration control unit (yaw angular velocity) 8.

The appeal of vehicles that run on rough, unpaved roads is the ability to precisely control tire traction, so a motor is built into the rear hub and the regenerative torque (braking force of the rear tire when decelerating and turning) of the motor built into the rear hub is controlled according to the rider's operation of the rear brake lever and the roll angle of the vehicle.

For this reason, the electrically assisted bicycle (hub motor) 1 is equipped with a free hub 2 on the rear hub, a motor 3 inside the rear hub, an angular velocity detection unit 4 that detects the angular velocity of roll and yaw of the electrically assisted bicycle (hub motor) 1, a roll angle calculation unit 5 that calculates the roll angle of the electrically assisted bicycle (hub motor) 1 from the angular velocity of roll detected by the angular velocity detection unit 4, a rear brake lever sensor 6 that detects the force applied to the rear brake lever by the rider, and a regeneration control unit (rear brake) 7 that determines the regenerative torque of the motor 3 based on the value detected by the rear brake lever sensor 6. If the roll angle calculated by the roll angle calculation unit 5 is A or less, the regenerative torque of the motor 3 is determined based on the regeneration control unit (rear brake) 7, and if the angular velocity detection unit 4 detects a yaw angular velocity of B or greater while controlling the motor 3 based on the regeneration control unit (rear brake) 7, the regenerative torque of the motor 3 is weakened so that the yaw angular velocity becomes B or less.

The electrically assisted bicycle (hub motor) 1 is equipped with a regeneration control unit (angular yaw velocity) 8 that determines the regeneration torque of the motor 3 based on the roll angle of the electrically assisted bicycle (hub motor) 1 calculated by the roll angle calculation unit 5 and the angular velocity of the yaw of the electrically assisted bicycle (hub motor) 1 detected by the angular velocity detection unit 4, and when the roll angle calculated by the roll angle calculation unit 5 is A or greater, the regeneration torque of the motor 3 is determined based on the regeneration control unit (angular yaw velocity) 8.

The regeneration control unit (rear brake) 7 of the electrically assisted bicycle 200 with a motor built into the rear hub is the same as that shown in Figure 4, and the regeneration control unit (yaw angular velocity) 8 is the same as that shown in Figure 3.

Figure 9 is a diagram illustrating an example of control of an electrically assisted bicycle with a motor built into the rear hub according to an embodiment of the present invention.

Steps S24 to S28 explain an example of motor control for an electrically assisted bicycle with a motor built into the rear hub.

In step S24, if the roll angle of the electrically assisted bicycle (hub motor) 1 calculated by the roll angle calculation unit 5 is A or less, the process proceeds to step S25, and if the roll angle of the electrically assisted bicycle (hub motor) 1 calculated by the roll angle calculation unit 5 is A or more, the process proceeds to step S28.

In step S25, the regenerative control unit (rear brake) 7 determines the regenerative torque of the motor 3 based on the pulling force of the rear brake lever detected by the rear brake lever sensor 6.

In step S26, if the angular velocity of the yaw of the electrically assisted bicycle (hub motor) 1 detected by the angular velocity detection unit 4 is equal to or greater than B, the process proceeds to step S27, and if the angular velocity of the yaw of the electrically assisted bicycle (hub motor) 1 detected by the angular velocity detection unit 4 is equal to or less than B, the process proceeds to step S25.

In step S27, the regenerative torque of motor 3 is weakened so that the yaw angular velocity of the electrically assisted bicycle (hub motor) 1 becomes equal to or less than B.

In step S28, the regenerative control unit (angular yaw velocity) 8 determines the regenerative torque of the motor 3 based on the roll angle of the electrically assisted bicycle (hub motor) 1 calculated by the roll angle calculation unit 5 and the yaw angular velocity of the electrically assisted bicycle (hub motor) 1 detected by the angular velocity detection unit 4.

This invention can optimally control the turning speed of electrically assisted bicycles that use fixed gears and electrically assisted bicycles that have a motor built into the rear hub.

100 Electrically assisted bicycle with fixed gear 1 Electrically assisted bicycle (fixed gear)
2 Fixed gear 3 Motor 4 Rotation direction detection unit 5 Torque detection unit 6 Assist control unit 7 Angular velocity detection unit 8 Roll angle calculation unit 9 Regenerative control unit (torque)
10 Regenerative control unit (yaw angular velocity)
11 Vehicle speed detection unit 12 Clutch 13 Rear brake lever sensor 14 Regenerative control unit (rear brake)

200 Electrically assisted bicycle with a motor built into the rear hub 1 Electrically assisted bicycle (hub motor)
2 Freehub 3 Motor 4 Angular velocity detection unit 5 Roll angle calculation unit 6 Rear brake lever sensor 7 Regenerative control unit (rear brake)
8 Regenerative control unit (yaw angular velocity)

Claims (10)

the motor is mechanically connected to the fixed gear, crank and rear tire on the rear hub, a rotation direction detection unit which detects whether the rotation direction of the crank is clockwise or counterclockwise, a torque detection unit which detects the torque applied to the crank by the rider, an assist control unit which determines the torque to be assisted by the motor from the torque detected by the torque detection unit, an angular velocity detection unit which detects the yaw angular velocity and roll angular velocity of the electrically assisted bicycle (fixed gear), a roll angle calculation unit which calculates the roll angle of the electrically assisted bicycle (fixed gear) from the roll angular velocity detected by the angular velocity detection unit, and a regeneration control unit (torque) which determines the regenerative torque of the motor based on the torque detected by the torque detection unit,
When the rotation direction detection unit detects that the crank is rotating clockwise, the assist control unit determines a torque to be assisted by the motor based on the torque detected by the torque detection unit,
When the rotation direction of the crank detected by the rotation direction detection unit is counterclockwise and the roll angle calculated by the roll angle calculation unit is equal to or smaller than A, a regenerative torque of the motor is determined based on the regenerative control unit (torque);
An electrically assisted bicycle (fixed gear), characterized in that when the angular velocity detection unit detects a yaw angular velocity of B or greater while the motor is being controlled based on the regenerative control unit (torque), the regenerative torque of the motor is weakened so that the yaw angular velocity becomes B or less. A regeneration control unit (yaw angular velocity) that determines a regeneration torque of the motor based on the yaw angular velocity detected by the angular velocity detection unit and the roll angle calculated by the roll angle calculation unit,
2. The electrically assisted bicycle (fixed gear) according to claim 1, characterized in that, when the rotation direction of the crank detected by the rotation direction detection unit is counterclockwise and the roll angle calculated by the roll angle calculation unit is A or greater, the regenerative torque of the motor is determined based on the regenerative control unit (yaw angular velocity). The electrically assisted bicycle (fixed gear) according to claim 2, further comprising a vehicle speed detection unit which detects the vehicle speed of the electrically assisted bicycle (fixed gear), and a clutch which controls the transmission torque within the rear hub, and wherein when the vehicle speed detected by the vehicle speed detection unit is equal to or lower than C, the clutch is released. 4. The electrically assisted bicycle (fixed gear) according to claim 3, wherein the clutch is released when the vehicle speed detected by the vehicle speed detection unit is equal to or higher than C and the torque detected by the torque detection unit is equal to or lower than a threshold value D. 5. The electrically assisted bicycle (fixed gear) according to claim 4, characterized in that when the vehicle speed detected by the vehicle speed detection unit is C or higher, the torque detected by the torque detection unit is D or higher, and the rotation direction detection unit detects that the crank is rotating counterclockwise, the clutch is controlled to reduce the transmitted torque so that the crank comes to a standstill. The electrically assisted bicycle (fixed gear) according to claim 5, characterized in that the clutch is engaged when the vehicle speed detected by the vehicle speed detection unit is C or higher, the torque detected by the torque detection unit is D or higher, and the rotation direction detection unit detects that the crank is rotating clockwise. Equipped with a rear brake lever sensor that detects the force applied by the rider to the rear brake lever,
7. The electrically assisted bicycle (fixed gear) according to claim 6, wherein the clutch is released when the rotation direction detection unit detects that the crank is rotating counterclockwise, the roll angle calculated by the roll angle calculation unit is equal to or less than A, and the value detected by the rear brake lever sensor is equal to or less than E. A regenerative control unit (rear brake) that determines a regenerative torque of the motor based on a value detected by the rear brake lever sensor,
When the rotation direction detection unit detects that the crank is rotating counterclockwise, and the roll angle calculated by the roll angle calculation unit is equal to or smaller than A, and the value detected by the rear brake lever sensor is equal to or larger than E, the clutch is engaged, and the regenerative torque of the motor is controlled based on the regenerative control unit (rear brake);
8. The electrically assisted bicycle (fixed gear) according to claim 7, characterized in that, when the angular velocity detection unit detects a yaw angular velocity of B or greater while the motor is being controlled based on the regenerative control unit (rear brake), the regenerative torque of the motor is weakened so that the yaw angular velocity becomes B or less. The bicycle is equipped with a free hub on the rear hub, a motor inside the rear hub, an angular velocity detection unit that detects the angular velocity of roll and yaw of the electrically assisted bicycle (hub motor), a roll angle calculation unit that calculates the roll angle of the electrically assisted bicycle (hub motor) from the angular velocity of roll detected by the angular velocity detection unit, a rear brake lever sensor that detects the force applied to the rear brake lever by a rider, and a regeneration control unit (rear brake) that determines the regeneration torque of the motor based on the value detected by the rear brake lever sensor,
When the roll angle calculated by the roll angle calculation unit is equal to or smaller than A, a regenerative torque of the motor is determined based on a regenerative control unit (rear brake);
This electrically assisted bicycle (hub motor) is characterized in that, when the angular velocity detection unit detects a yaw angular velocity of B or more while the motor is being controlled based on the regenerative control unit (rear brake), the regenerative torque of the motor is weakened so that the yaw angular velocity becomes B or less. a regeneration control unit (angular velocity of yaw) that determines a regeneration torque of the motor based on the roll angle calculated by the roll angle calculation unit and the angular velocity of yaw detected by the angular velocity detection unit;
10. The electrically assisted bicycle (hub motor) according to claim 9, wherein when the roll angle calculated by the roll angle calculation unit is equal to or greater than A, the regenerative torque of the motor is determined based on the regenerative control unit (yaw angular velocity).

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