US Patent 9114850 Motor drive control device

A motor drive control device of an electric power-assisted vehicle that has a gear shifter and a motor, and in which a first ratio of the number of drive rotations in the motor to the number of drive rotations of a pedal changes based on changes in a gear ratio in the gear shifter, includes: a gear ratio obtaining part that obtains the gear ratio of the gear shifter; and a calculating part that calculates an assist torque, which is a target value for a drive torque of the motor, from the pedal input torque based on the gear ratio obtained by the gear ratio obtaining part.