Robust PID2 - Ms Tuning rules for Unstable systems with two RHP poles

Numerous proportional integral derivative (PID) controllers are available to control the time delayed unstable processes with two right half plane poles (RHP). But the methods developed formerly are quite complex. To increase the ease of use and applicability, novel maximum sensitivity-based control tuning rules are framed based on the H
₂
optimal control and IMC theory. The analytical expressions are derived for varying ratios of time constant in the range 0.3-0.9 with the normalized dead time of 0.1. The desired level of robustness is selected between 3 and 6, to have a reasonable compromise between robustness and performance. Simulation studies have been performed on varied examples to solve the trade-off issues and to compare the performance for servo tracking and load variable rejection. The robust characteristics of the proposed controller particularly while uncertainties are present elucidate the efficacy of the work proposed.