Patent ID: 7411366

Claim:
An electric power-assist system for a manually operated vehicle having a rotatable manual controlling device, said electric power-assist system comprising: a speed sensor for detecting the rotational speed of the manual controlling device; a speed decision block for comparing the rotational speed of the manual controlling device with a reference speed to detect whether the rotational speed of the manual controlling device is accelerating or decelerating; an up/down counter for increasing a count when the rotational speed of the manual controlling device is accelerating and decreasing a count when the rotational speed of the manual controlling device is decelerating; an electric motor for power assisting the driving force of a wheel of the vehicle; a power driver for supplying power to the electric motor and for producing a current power level signal representing the current power level supplied to the electric motor; and a comparator for comparing the counted result of the up/down counter with the current power level signal, whereby the amount of assisting power delivered by the electric motor increases or decreases, as the speed of the manual controlling device increases or decreases, respectively.