Question: (a) The dynamic performance of the system was deemed too oscillatory with the initial tuning calculated via Ziegler-Nichols correlations. How would you change the tuning constants, which constants, and by how much to achieve reasonably good performance with little oscillation?

(b) Given the results in Example which showed that the Ziegler Nichols tuning correlations do not seem to yield robust control performance for low fraction dead time, how would you modify the ZieglerNichols correlations for θ/(θ + τ ) <>

Example: The two following different first-order-with-dead-time processes are to be controlled by PI controllers. Calculate the tuning constants for each and compare the results.