Abstract: A bicycle includes a vehicle-body frame, a front wheel that is a steered wheel, a rear wheel, a crankshaft, a pedal, a transmission to transmit rotation of the pedal to the rear wheel, a motor to apply at least a torque to cause rearward rotation of at least one of the front wheel or the rear wheel, a roll detector to detect at least one of a roll angle or a roll angular velocity of the vehicle-body frame, and a steering detector to detect a direction of steering. When a vehicle speed is zero and a steering angle of the front wheel is not zero, the motor applies, to the at least one of the front wheel or the rear wheel, a torque to maintain the roll angle of the vehicle-body frame based on the detected direction of steering and the at least one of the roll angle or the roll angular velocity.

Abstract: An electrical apparatus includes a housing including an opening, an electronic component in the housing, electrical wires connected to the electronic component and extending out of the housing through the opening, a plug extending in a first direction and inserted in the opening with the electrical wires passing through the opening, and a waterproofing material in the opening. The plug includes a first outer peripheral surface matching an inner wall surface of the opening, and a second outer peripheral surface opposite and spaced apart from the inner wall surface of the opening. The electrical wires are between the second outer peripheral surface and the inner wall surface of the opening.

Abstract: A notification system for an electric power assisted vehicle includes two or more notifiers to notify a user that a remaining charge of a battery that supplies power to an electric motor is low, and a controller configured or programmed to control operations of the two or more notifiers. The two or more notifiers include two or more of a display panel to display the remaining battery charge, a lamp to emit light, and a sound component to produce sound. The controller is configured or programmed to compare the remaining battery charge with a predetermined value, and when the remaining battery charge is lower than or equal to the predetermined value, to notify the user that the remaining battery charge is low by a combination of the operations of the two or more notifiers.

Abstract: An electric assist system usable for an electric assist bicycle includes an electric motor that generates assist power assisting human power of a rider of the electric assist bicycle, a rotation sensor that outputs a signal in accordance with a rotation of a rotatable component that rotates to operate the electric assist bicycle, an acceleration sensor that outputs a signal in accordance with an acceleration of the electric assist bicycle in a traveling direction thereof, and a controller that calculates a speed of the electric assist bicycle based on an output signal of the rotation sensor and an output signal of the acceleration sensor.

Abstract: An electric assist system for an electric assist vehicle includes a crankshaft rotatable by human power of a rider applied to a pedal, an electric motor that generates an assist power that assists the human power of the rider, a controller that controls a magnitude of the assist power to be generated by the electric motor, and an acceleration sensor that outputs a signal in accordance with an acceleration in a traveling direction of the electric assist vehicle. The controller changes the magnitude of the assist power to be generated by the electric motor in accordance with a change in the acceleration that is associated with an operation of the rider rotating the pedal.

Abstract: An electric power assist system generates an appropriate level of assist power while an electric assist vehicle is running on a slope and includes an electric motor that generates an assist power to assist human power of a rider of the electric assist vehicle, a controller that controls a magnitude of the assist power to be generated by the electric motor, and an acceleration sensor that outputs an acceleration signal representing an acceleration in a travel direction of the electric assist vehicle. The controller acquires speed information representing a running speed of the electric assist vehicle based on an external signal, detects an inclination angle of a road surface based on the speed information and the acceleration signal, and causes the electric motor to generate an assist power of a magnitude in accordance with the inclination angle.

Abstract: An electric assist system usable for an electric assist bicycle includes an electric motor that generates assist power assisting human power of a rider of the electric assist bicycle, a rotation sensor that outputs a signal in accordance with a rotation of a rotatable component that rotates to operate the electric assist bicycle, an acceleration sensor that outputs a signal in accordance with an acceleration of the electric assist bicycle in a traveling direction thereof, and a controller that calculates a speed of the electric assist bicycle based on an output signal of the rotation sensor and an output signal of the acceleration sensor.

Abstract: An electric power assist system generates an appropriate level of assist power while an electric assist vehicle is running on a slope and includes an electric motor that generates an assist power to assist human power of a rider of the electric assist vehicle, a controller that controls a magnitude of the assist power to be generated by the electric motor, and an acceleration sensor that outputs an acceleration signal representing an acceleration in a travel direction of the electric assist vehicle. The controller acquires speed information representing a running speed of the electric assist vehicle based on an external signal, detects an inclination angle of a road surface based on the speed information and the acceleration signal, and causes the electric motor to generate an assist power of a magnitude in accordance with the inclination angle.

Abstract: An electric assist system for an electric assist vehicle includes a crankshaft rotatable by human power of a rider applied to a pedal, an electric motor that generates an assist power that assists the human power of the rider, a controller that controls a magnitude of the assist power to be generated by the electric motor, and an acceleration sensor that outputs a signal in accordance with an acceleration in a traveling direction of the electric assist vehicle. The controller changes the magnitude of the assist power to be generated by the electric motor in accordance with a change in the acceleration that is associated with an operation of the rider rotating the pedal.

Abstract: An electric assistance system used in an electrically assisted vehicle provided with a pedal includes a crankshaft rotatable by human power of a rider applied to the pedal, a torque sensor that outputs a torque signal in accordance with a magnitude of a torque generated at the crankshaft, an electric motor that generates an assist power that assists the human power of the rider, an acceleration sensor that outputs an acceleration signal in accordance with a current acceleration in a travel direction of the electric assist vehicle, and a controller that receives the torque signal and the acceleration signal and determines a magnitude of the assist power to be generated by the electric motor. The controller calculates a target acceleration from the torque signal based on a rule prepared in advance, and determines the magnitude of the assist power to be generated by the electric motor such that a deviation between the target acceleration and the current acceleration is decreased.