To allow assist control according to the pedal force to be performed in a bicycle electric power assist device without complicating the structure for detecting the pedal force and/or requiring modification of the bicycle, a bicycle electric power assist device (50) includes: an electric motor (54) connected in a torque transmitting relationship to a crank arm (26) or a crankshaft (24) driven by a pedal force from pedals (30) via the crank arm (28); a battery (102) to be mounted on a bicycle to serve as a power supply for the electric motor (54); a control unit (100) configured to control operation of the electric motor (54); a rotation angle sensor (110) configured to detect a crank rotation angle position of the crankshaft (24); and a current sensor (116) configured to detect a motor current of the electric motor (54), wherein the control unit (100) includes: a pedal force estimation/calculation unit (120) configured to estimate the pedal force of the pedals (30) from a difference between the motor current in a first crank rotation angle position and the motor current in a second crank rotation angle position which is different from the first crank rotation angle position; and a motor drive control unit (126) configured to control a drive current of the electric motor (54) according to the pedal force estimated by the pedal force estimation/calculation unit (120).
ELECTRIC ASSIST DEVICE FOR BICYCLE, AND BICYCLE
ELEKTRISCHE HILFSVORRICHTUNG FÜR FAHRRÄDER UND FAHRRAD
DISPOSITIF D'ASSISTANCE ÉLECTRIQUE POUR BICYCLETTE, ET BICYCLETTE
2023-12-20
Patent
Electronic Resource
English
European Patent Office | 2018
|European Patent Office | 2018
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