Robust μcontroller implementations for a linear pneumatic actuator interaction

Abstract

Over the years, pneumatic systems have recorded a remarkable performance in automated applications, based on their cost to efficiency ratio and ease of energy transmission. Therefore, their drawback of not being totally controllable devices in terms of position accuracy, still represents a challenge task for engineers. In this paper, a traditional three term controller (PID) is designed for the task which is implemented in the system with an intelligent and not straightforward manner. The Integral term of the controller is not operating all the time during and parallel to the pneumatic piston stroke. The I-term will be switched 'on' and 'off', considering the system performance and needs. This ensures a robust control algorithm design, a faster system response and the avoidance of chattering around the demand position of the piston set point. In addition to this, an electrical board will be designed and produced in order to host all electronics like, a microprocessor, various amplifiers and converters, and a serial port for communication between the user and the system. An interface window is also implemented for the user to be able to export information of the system and record all data acquisition results as well as provide to an engineer a useful tool for re-programming the controller and download multiple versions of control code to the system. All results of the system performance are monitored and a representative pack of them are illustrated in the main body of this paper.