Evy Haraldseid & Monika Johansen (1999): 
"Testing av regler for tuning av PID-regulatorer" (In Norwegian)
Student report R99-28 (4th year), Dept. of Chemical Engineering, NTNU, Trondheim
Nov. 1999

There is no electronic version of this report.

Summary:
Evaluate the Skogestad PID tuning rules and possible modifications.


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Figure B3-5:  Evaluation of using modified itegral time x*theta (rather than 8*theta):

Integrating process with delay: g = e(-theta s) / s
Results:
		Kc	tauI	IAE(ys)	IAE(d)	GM	PM	Ms	Mt	thetamax
Skogestad(SIMC)	0.5	8	3.90	8.02	2.96	46.80	1.70	1.30	1.58
Modified SIMC	0.5	4	4.05	4.47	2.74	34.04	1.96	1.74	1.27
Modified SIMC	0.5	3	4.75	4.51	2.56	26.86	2.32	2.17	0.81
ZN		0.71	3.33	3.91	2.81	1.87	24.86	2.82	2.34	0.57

Conclusion: Lower integral time tauI gives better performance for disturbancesd (IAEd)
but the robustness is worse.