Method and apparatus for using fast fourier transform feedback to compensate for non-linear motion

• US 6,725,101 B2
• Filed: 12/13/2000
• Issued: 04/20/2004
• Est. Priority Date: 12/13/2000
• Status: Expired due to Fees

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Williams, Lloyd A., de Jong, Joannes N. M., Costanza, Daniel W., Williams, Vincent M., Sanchez, Rene E.
• Primary Examiner(s): Starks, Jr., Wilbert L.
• Assistant Examiner(s): Liu, Joshua C
• Application Number:
  US09/736,520
• Publication Number:
  US 20020072812A1
• Time in Patent Office: 1,224 Days
• Field of Search: 700/45, 700/261, 318/610, 318/616, 399/46, 328/127, 360/73, 381/71
• US Class Current: 700/45
• CPC Class Codes: G05B 13/0265 the criterion being a learning criterion
• CPC Class Codes: G05B 21/02 electric

Abstract

A non-linear control (NLC) system for controlling performance of a device. The NLC system comprises a controller system and a first feedback compensator connected to the controller. The first feedback compensator compensates for linear error performance of the device; the second feedback compensator compensates for non-linear error performance of the device.

Claims

1. A hybrid learning feedback controller (HLC) system for controlling operation of a xerographic imaging device, the xerographic device having an input port and an output port, the HLC feedback controller system comprising:

a feed forward controller system operative to receive an actuating signal and in response to the actuating signal output a manipulated variable, the feed forward controller system comprising;

a feed forward controller;

a first input summing node connected to the feed forward controller, the first input. summing node operative for summing a reference input and a first feedback signal;

a second input summing node connected to the feed forward controller, the second input summing node operative for summing the manipulated variable and a second feedback signal;

a first proportionality device serially connected to the second input summing node and the input port of the xerographic imaging device;

a first feedback compensator connected to the controller; and

a second feedback compensator connectable to the controller, the second feedback compensator having a learning controller system for correcting non-linear motion of the device;

wherein the second feedback compensator comprises;

a sampling device; and

a signal generator connected to the sampling device, the signal generator operative to produce the second feedback signal,

wherein sampling device comprises;

fast Fourier transform (FFT) device;

a magnitude detector connected to the FFT device; and

a phase comparator connected to the magnitude detector.

2. A HLC system as in claim 1 wherein the first feedback compensator comprises:

a second proportionality device connected to the output port of the xerographic imaging device;

a first feedback element connected to the second proportionality device, the first feedback element operative to produce an intermediate feedback signal; and

a third proportionality device connected to the first feedback element, the third proportionality device operative to produce the first feedback signal.