Electricity aided bicycle and auxiliary power controlling method thereof

An electricity aided bicycle, comprising:

• a driving circuit, receiving a command voltage and driving an auxiliary motor of the electricity aided bicycle based on the command voltage;
• a rotating speed detector, generating a detection signal having a plurality of pulses based on a rotation status of a driving gear of the electricity aided bicycle;
• and
• a command voltage generator, coupled to the rotating speed detector and the driving circuit, receiving the detection signal, and configured to:
• calculate a plurality of times between two adjacent pulses in the pulses of the detection signal;
• perform a numerical value derivation operation based on the times to generate an estimated velocity value;
• set an electricity aid strategy table to calculate the command voltage based on the estimated velocity value and the electricity aid strategy table,
• wherein the electricity aid strategy table records a relation between an electricity aid ratio and the estimated velocity value,
• wherein the times comprise a first time, a second time, and a third time, the command voltage generator calculates a plurality of reciprocals of the first time, the second time, and the third time, and performs the numerical value derivation operation based on the third time and the reciprocals,
• wherein the estimated velocity value is equal to
• 1
• T
• K
• +
• 1
• 2
• 
• [
• 1
• T
• K
• -
• 1
• T
• K
• -
• 1
• ]
• +
• T
• K
• 8
• [
• 1
• T
• K
• -
• 1
• T
• K
• -
• 1
• T
• K
• -
• 1
• T
• K
• -
• 1
• -
• 1
• T
• K
• -
• 2
• T
• K
• -
• 1
• ]
• ,
• wherein TK is the third time, TK−1 is the second time, and TK−2 is the first time.