PID Temperature Control for a PET Extruder Heating Block

With the aim of minimizing the PET waste generated at our university, a group of students and professors from the Mechatronics Engineering program proposed the development of a machine capable of converting this waste into filament for the university's 3D printers. This would allow other students and professors to carry out their projects with improved quality while reusing materials that are discarded daily both inside and outside the university. Therefore, the following is proposed:

Control systems are a set of interconnected components that work together and have the ability to regulate or adjust themselves automatically. This self-regulating capability allows them to maintain a process or variable within a desired range without the need for human supervision. In control systems, a PID (Proportional, Integral, and Derivative) is a control method commonly used in process automation and variable control. It is named as such because it combines proportional, integral, and derivative control.

The process variable in this case is the temperature, which is generated by a heating block in the 3D printer. This variable will gradually increase (raising the temperature) until the system gradually eliminates the existing error between the reference temperature and the actual temperature, that is, the error should be close to zero.

After completing the theoretical section of the system, physical tests were conducted using an Arduino Nano to demonstrate the thermal functioning using the gains of the PID:

In the above image, the connections on the breadboard can be seen. We can highlight the power circuit (the plant of the system), which consists of two transistors: a MOSFET and a BJT, along with an optocoupler. The MOSFET directly switches the heating block, gradually heating it to reach a set temperature.

The LabView application was developed to verify the operation of the control system, and it reacts as intended.

For everyday operation, the Arduino PID library will be used.

The control system utilizes a PCB to withstand the intended use. For this purpose, a final design of a printed circuit board was created. This board includes a regulated voltage source based on the LM2596, a serial interface for communication with a computer, and the power circuit.

With the support of PCBWay, we will be able to carry out this project. The Mechatronics program at our university will directly benefit from this support, enhancing education and expanding knowledge in efficient design and development for high-quality printed circuit boards. Our entire team of students and professors is excited to collaborate and work with PCBWay to bring this project to fruition.