Computer-Based Control for Chemical Systems Using LabVIEW® in Conjunction with MATLAB®

Abstract

Current trend and characteristics in chemical industries has become more complex, hybrid and intensified in nature thus requiring faster and more powerful control systems to perform adequate control action for optimal performances (Charpentier, 2005). The time would not be more suitable to accommodate this advancement in the chemical industries with the existence of more powerful computer technologies either hardware or software. This development of more advanced and powerful computer architecture provides a better alternative to address the problems of performing optimally for the state-of-the-art chemical industries. Thus, computer-based control systems become the inevitable platform for fast, precision and close control of chemical processes. The advanced, powerful and user-friendly programming environment enables the process control engineers to easily design appropriate controller with minimal time and at lower cost, eventually implementing the designed controller directly on the actual systems via these tools. MATLAB® and LabVIEW® are amongst the most powerful and useful software that can be extremely helpful in this regard. MATLAB® is a very powerful mathematical tool, which enables us to use its powerful controller design toolboxes and also perform simulation in SIMULINK® environment with ease. Nonetheless, interfacing the control equipments such as measurement devices and control valves via MATLAB® is not an easy task. In contrast, LabVIEW® is among the best available software for communicating with the hardware in PC based systems. Utilising LabVIEW® facilitates easy data acquisition from the hardware and sending the corresponding signal to the final control element. The idea of incorporating the two software for the computer-based control system would enable us to have an easy data acquisition (getting signal from all measurement devices and processing the signal to the desirable form) using LabVIEW® and then the signal is transferred to MATLAB® which conventionally acts as the controller to perform control calculation. Finally, the output signal from the controller is transferred back to LabVIEW® software to be applied to the final control element to perform adequate corrective action. In order to connect these two software, there are number of toolboxes in LabVIEW® which can help the user to easily connect them based on the needed environments. For example, using SIMULINK Interface Toolkit (SIT), LabVIEW® can easily communicate with SIMULINK environment in a continuous mode. The proposed combination of these two powerful software not only can help researchers to design and implement their designed controller in various forms in a very short time but