Analysis of Multivariable Process -A Study on Cascade Process

The work focuses on the development and real time analysis of different control techniques for level to flow control process (in cascade control action). Inner loop comprises of flow process and the outer loop comprises of level process. At first, process model for flow and level is identified by step test method. The identified process models are validated. Based on the obtained model, Ziegler Nichols, Cohen-Coon and Internal Model Control, techniques are applied. Performance comparison of different control techniques are studied and the best suitable controller for cascade process is highlighted through time domain specifications (rise time, settling time, overshoot) and error criterion analysis (integral square error and integral absolute error).