In general, paper moving through a copy machine is an open loop process. Motors driving the paper are preprogrammed and the machine has no way to dynamically steer the paper during use. Thus, machine “jams” can occur any time a sheet fails to reach a certain point on time or shifts too far to one side. In this project, we are working to control the speed of the paper and correct for lateral and skew errors.

Two independently steered nips have been designed to drive each sheet through one section of the paper path. The independently steered nips allow us to correct both lateral and skew errors but also introduce another problem – paper buckle. If the paper is not rigid enough, the nips can drive a sheet into itself causing the paper buckle to between the nips. Paper, however, has little elastic stretch and streaks can occur due to slipping at the nips. Identifying buckle conditions and ensure that the paper will not stretch (or streak) is vitally important to this design.

This project involves the design and fabrication of a paper handling system with three degrees of freedom. Nonlinear and hybrid controller designs are implemented real-time using dSpace and MATLAB. This project is supported by the National Science Foundation through GOALI project 9632828 labeled “Mechatronic Design and Control of Media Handeling Mechanisms for Printer Engines” in cooperation with research partner Xerox Company.

Project Members:
Rene Sanchez
Benjamin Fine
Edgar Ergueta