Iterative Learning Control for Motion Error Reduction

An apparatus for reducing registration errors in a media handling device, the apparatus comprising:

• an intermediate transfer belt for conveying marking material corresponding to an image, the intermediate transfer belt interacting with sheets of substrate media as the sheets are individually conveyed across the intermediate transfer belt, wherein the passing interaction of each of the sheets with the intermediate transfer belt corresponds to one of a series of iterations between the intermediate transfer belt and the sheets;
• a sheet transfer belt for conveying the sheets into engagement with the intermediate transfer belt;
• and
• a controller operatively coupled to at least one of the intermediate transfer belt and the sheet transfer belt, wherein the controller receives input signals, at least a portion of the input signals representing at least one measured disturbance, each disturbance being defined by a pattern of intermediate transfer belt movement away from and substantially returning to a reference state of motion, a repetition of the pattern being coincident with at least one of the iterations, wherein based on the measured disturbance, the reference state and an indication associated with when the pattern will repeat, a modified signal is generated for adjusting the intermediate transfer belt motion in coordination with the indication.

An apparatus for reducing registration errors in a media handling system, the apparatus comprising:

• a first image-bearing member and a second image-bearing member, the first and second image-bearing members conveying marking material corresponding to at least a portion of an image, wherein each of the image-bearing members interact with sheets of substrate media as the sheets individually pass across the respective image-bearing members, wherein one sheet pass across one of the image-bearing members corresponds to one of a series of iterations between the image-bearing members and the sheets;
• at least one sheet transfer member conveying the sheets into direct engagement with the first image-bearing member and subsequently the second image-bearing member;
• a controller operatively coupled to the first and second image-bearing members and the at least one sheet transfer member, wherein the controller receives input signals, at least a portion of the input signals representing at least one measured disturbance, each disturbance being defined by a pattern of movement of at least one of the first and second image-bearing members away from and substantially returning to a reference state of motion, a repetition of the pattern being coincident with at least one of the iterations, wherein based on the measured disturbance, the reference state and an indication associated with when the pattern will repeat, a modified signal is generated for adjustment of the at least one of the image-bearing members motion in coordination with the indication.

A method of reducing registration errors in a media handling system, the method comprising:

• receiving input signals from a sensor arranged to measure disturbances to an image-bearing member, wherein the image-bearing member interacts with sheets of substrate media as the sheets individually pass across the image-bearing member, each sheet pass corresponding to one of a series of iterations between the image-bearing member and the sheets, wherein at least a portion of the input signals represent at least one measured disturbance, each disturbance being defined by a pattern of image-bearing member movement away from and substantially returning to a reference state of motion, a repetition of the pattern corresponding to one of the iterations;
• comparing the measured disturbance and the reference state;
• and
• generating a modified signal for adjusting the image-bearing member motion in coordination with an indication associated with when the pattern will repeat, the measured disturbance and the reference state.

A method of reducing registration errors in a modular media handling system, the method comprising:

• receiving input signals from a first sensor arranged to measure disturbances to a first image-bearing member, wherein the first image-bearing member interacts with sheets of substrate media as the sheets individually pass across the first image-bearing member, each sheet pass corresponding to one of a series of iterations between the first image-bearing member and the sheets, wherein at least a portion of the input signals represent at least one measured disturbance, each disturbance being defined by a pattern of first image-bearing member movement away from and substantially returning to a reference state of motion, a repetition of the pattern corresponding to one of the iterations;
• comparing the measured disturbance and the reference state;
• and
• generating a modified signal for adjusting the motion of a second image-bearing member in coordination with an indication of when the pattern will occur with respect to the second image-bearing member, the modified signal determined by the comparison of the measured disturbance and the reference state.