Patent ID: 7606624

Claim:
A method for calculating a derivative term in a closed-loop controller that receives position error information at each servo processing interval, the method comprising computer-implemented steps of: performing a self-commissioning process to compute a motor model that relates a motor control signal applied by a first controller to a motor to a motion of the motor, where the self-commissioning process is automatically performed in response to receipt of a first user input and the motor model is computed without requiring second user input, and the self-commissioning process includes: determining a number of position error readings to be supplied to the closed-loop controller for use in computing a derivative term; and supplying the determined number of position error reading to the closed-loop controller; computing a derivative term in the closed-loop controller, where the computer-implemented steps of calculating the derivative term includes computer-implemented code for the computer-implemented steps stored on a computer-readable medium for: recording three or more position error readings at different servo processing intervals; computing a derivative estimate by: summing two or more of the position error readings; and subtracting an equal number of different position error readings than used in the summing step; and then computing the derivative term based on the derivative estimate; and generating a motor control signal based in part on the computed derivative term.