Signal noise filter structure selection for predictive PI controller in a wireless networked control setting

Abstract

The predictive proportional integral (PPI) controller being simple and non conservative like its Smith predictor and internal model control (IMC) counterparts, has the ability to be employed in environments characterised by uncertainties such as stochastic network delays. However, its performance degrades in the presence of measurement noise. This is due to the prediction involve in the controller which acts like the derivative term of PID controller that amplifies high frequency noise. This necessitated the need for additional filtering of the noisy signals. Therefore, this work proposes three several filter configurations for PPI controller in a wireless environment. Simulation results shows that placing the filter within the PPI controller gives smooth control signal that can yield better control performance compared to both feedback and cascade filter configurations.