Quiet retraction system

A quiet retraction method for regulating constant velocity while parking an arm within a disk drive is described. The method comprises the steps of: driving a motor for the arm using a first drive current for a first period; floating the motor; sampling a back electromotive force (bemf) for a first sampled voltage, while floating the motor; driving the motor with a second drive current during a second period in response to sampling the bemf; determining whether the second drive current exceeds a current limit; estimating the bemf using the first sampled voltage when the second drive current exceeds the current limit; driving the motor with a third current during a third period in response to estimating the bemf; wherein driving the motor with the first, second, and third currents quietly parks the arm, while regulating the constant velocity.