Patent ID: 7628398

Claim:
A method of performing sheet registration in process, lateral, and skew directions, the method comprising: identifying output values for a sheet within a reference frame; determining a difference between each identified output value and a corresponding desired output value; determining controller input values for the sheet based on at least the differences; determining state feedback values based on information received from at least one sensor, wherein the state feedback values comprise coordinates of a point on the sheet, an angle of the sheet, and angular velocities of a plurality of drive rolls; and for each of the plurality of drive rolls: determining a desired acceleration value for the drive roll based on the controller input values and the state feedback values, determining a desired angular velocity value for the drive roll based on the desired acceleration value, and determining a motor voltage for a motor for the drive roll that causes an observed angular velocity value for the drive roll to track the desired angular velocity value for the drive roll, wherein the desired acceleration values for the plurality of drive rolls are determined such that second derivatives with respect to time of the identified output values are equal to the controller input values, wherein, using the same reference frame, the above-listed identifying and determining steps are performed a plurality of times such that the identified output values track the desired output values, wherein the sheet is registered by the plurality of drive rolls based on the motor voltages for the motors.