Cycle-to-cycle control of plastic sheet heating on the AAA thermoforming machine

• Main Author: Yang, Shuonan, 1984-
• Format: Others
• Language: en
• Published: McGill University 2008
• Subjects: Intelligent control systems.; Iterative methods (Mathematics); Thermoforming.
• Online Access: http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=111945

The objectives of this project are (1) to reduce the excursions between real heater temperatures and the desired values, and (2) to realize cyclic production of plastic sheets on the AAA thermoforming machine. === At first, present relevant knowledge and modeling of the AAA machine are covered. A programmable pre-processing module is inserted before the heaters to prevent the input commands from delaying in heater response. The results prove that the excursions can be theoretically reduced to zero. === Based on the Terminal Iterative Learning Control (TILC) algorithm, a hybrid dual-mode cascade-loop system is designed: the inner loop monitors the real-time temperatures for PID control in Mode 0, while the outer loop reads temperatures and commands once per cycle to decide the necessity of switching mode. A more realistic version with flexible cycle length and instant response to operator's commands is also designed to simulate the real operating circumstance.