Patent ID: 6510019
Filing Date: 2003-01-21
Classification: G11B

Abstract:
A method for controlling a position of a device comprising:providing a device, the device having a motion defined by a position, a velocity, and an acceleration; providing a control signal, the position of the device being responsive to the control signal; and varying the control signal, as the device approaches a desired location, according to a nonlinear function of the position, the velocity, and the acceleration wherein the velocity and the acceleration converge on zero as the device approaches the desired position, and wherein varying the control signal further comprises: determining a convergence constant that defines the manner in which the acceleration converges to zero, varying the control signal in proportion to the convergence constant, determining a tracking error, the tracking error calculated by multiplying the convergence constant by the velocity squared and dividing by the position, and subtracting therefrom the acceleration, and varying the control signal according to the tracking error.