Design of Noise Filters for Integrating Time Delay Processes

Abstract

Abstract In this research, a second order noise filter is designed for reducing the noise effect on PID controlled Integrating plus time delay (IPTD), Integrating plus first order plus time delay (IFOPTD), Double integrating plus time delay (DIPTD) processes. The second order noise filter time constant is designed based on an iterative approach, which is a function of loop gain crossover frequency ( {\omega _{gc}}) and a design parameter \,\left( {{\beta }} \right). Based on the data obtained from an integrating process and the controller, the controller parameters are calculated using Optimal H2 -IMC based technique. The design parameter ( {{\beta }}) is selected as a compromise among robustness, performance and reduction of measurement noise. Simulation studies are carried out on different IPTD, IFOPTD and DIPTD processes to illustrate the amount of reduction of noise effect on process output and controller output. The effect is also calculated based on Integral Absolute Error (IAE), Integral Square Error (ISE) and Total Variance (TV) criteria by considering perfect and perturbations in the process parameters.