System and method for synchronous control of rotary presses

A synchronous control system for rotary presses comprising a master control section for controlling the entire system, drive means provided on a plurality of printing units and a folding unit that cuts and folds a printed paper web into printed images for independently driving the printing and folding units, and control sections for controlling the drive means for each unit;

• at least one printing unit having a plurality of web paths running from the printing unit in question to the folding unit, and printing being carried out by passing the paper web through any of the web paths:
• the improvement comprising the printing unit control section having a plurality of web paths comprising
• a drive reference receiving section for receiving a drive reference from the master control section,
• a phase correction value output section for generating a phase correction value proportional to the residual length obtained by dividing the length of a selected web path from the printing unit in question to the folding unit with the outer periphery length of the printing cylinder of the printing unit in question,
• a drive reference speed signal output section for generating a signal relating to a drive reference speed based on the drive reference received by the drive reference receiving section,
• a corrected drive reference phase signal output section for generating a signal relating to a corrected drive reference phase obtained by correcting with the phase correction value the drive reference phase based on the drive reference received by the drive reference receiving section,
• a feedback signal receiving section for receiving a feedback signal on the operating state of the printing unit in question,
• a feedback speed signal output section for generating a signal relating to a feedback speed based on the feedback signal received by the feedback signal receiving section,
• a feedback phase signal output section for generating a signal relating to a feedback phase based on the feedback signal received by the feedback signal receiving section,
• a phase difference detecting section for detecting a phase difference between a corrected drive reference phase and the feedback phase from the corrected drive reference phase signal and the feedback phase signal,
• a phase difference signal output section for generating a signal relating to a phase difference detected by the phase difference detecting section, and
• a signal correcting section for correcting a phase difference signal relating to a phase difference between the corrected drive reference phase and the feedback phase and the drive reference speed signal based on the feedback speed signal, and generating a corrected control signal;
• the drive means of the printing unit in question being controlled by the corrected control signal generated by the signal correcting section via a motor driver.