Development of a Laboratory-scale sheet stamping machine based on a PLC-Based Control System

A significant gap often exists between the theoretical knowledge of industrial automation taught in universities and the practical skills required in the field. To address this challenge, this thesis presents the complete development of a Programmable Logic Controller (PLC) based control system designed to demonstrate a scalable industrial process within a laboratory environment. The project's core is a lab-scale sheet stamping machine, realized through the integration of a Siemens S7-1200 PLC, a KTP700 Human-Machine Interface (HMI), a DC geared motor, a solenoid actuator and an industrial incremental rotary encoder with a resolution of 600 Pulses Per Revolution (PPR) coupled with a measurement wheel, having a circumference of 250 mm. This measurement setting provides a linear resolution of approximately 0.42mm/pulse that was determined to be sufficient for the project’s performance goals of ±10 mm positional accuracy and ± 5mm of repeatability. The system automates the process of feeding a paper sheet and stamping it at user-defined intervals. The operator uses the HMI that serves as a monitoring and control panel for this automated system. Its intuitive touch interface design allows the user to monitor real-time process data, fault alarms and to set process parameters defined by the desired length of interval that must be passed between each consecutive stamp and the desired number of total stamps that must be made before the automated cycle ends. The PLC utilizes these set points to execute its control logic, while tracking the sheet’s linear travel by processing the encoder's pulse count. This thesis documents the complete engineering workflow, from defining the system requirements and selecting components, to the mechanical design in SolidWorks, configuration of the UltiMaker Cura Software for converting the designed model into a 3D-printer compatible G-Codes, which were optimized for quality and time consumption and the resulting mechanical 3D printed fabrication, electrical connections, PLC and HMI software development in TIA Portal, and final system testing and performance calibration. The control program, implemented in Ladder Logic, features position tracking using the PLC's high-speed counter, synchronized motor and actuator control, and the implementation of fault detection algorithms for feed roller and stamp actuator, based on the encoder data and the current feedback of the solenoid stamp actuator respectively. The resulting platform functions as a successful proof-of-concept for an industrial automated stamping system and serves as a valuable and flexible educational tool. It provides students with a hands-on opportunity to engage with industrial hardware and immediately observe the impact of their changes. A set of guided lab assignments could be developed for students that could include different tasks, such as implementing a new fault detection routine, designing a more intuitive HMI display with alarm history, optimizing the control logic for higher throughput, effectively bridging the gap between academic theory and practical engineering applications.