Design requirements and reference trajectory generation for a copier paperpath

Presents an approach to introducing closed loop control in a copier paperpath in order to achieve robust, high-speed media handling. The basic idea exploits periodicity in the relative position of correctly fed sheets and their corresponding images. It is shown that the periodic behavior allows to design polynomial position reference trajectories for sheets as a function of their initial position error. Only longitudinal position errors are considered. By measuring sheet positions and using closed loop control to track the reference trajectories, position errors can be successfully removed. In addition to the reference trajectories, the paper also offers a design strategy that minimizes the required paperpath length while satisfying given bounds on sheet velocities and accelerations. Two examples, each with different initial error bounds, illustrate the design algorithm.