Dear Proff. Skogestad
I am a MSc. student majoring in control engineering. I'm doing my thesis on Control Structure Design; But I have some problem with scaling. I have reviewed your distillation column case study. As it seems you have scaled output variables, using maximum expected change in error signal which can be obtain simply by simulation. But it is not obvious that how you scale the input variables.
I have some ideas about scaling. I decided to obtain a systematic method to find the scaling factors. I have used Singular Value Decomposition as a meature to know how much is the maximum effect of the inputs on the outputs? Also I obtain a RSE (Rational Scaling Error) factor to determine the truth of the scaling. I used "RGA norm sum" and "condition number" to obtain the RSE. I test your distillation column scaling with this RSE meature. It has a very good scaling. Let me know your idea about what I have done. Would you please help me to know your ideas about my theories? And would you please write me how you scaled the input variables of your distallation column? Let me to appreciate you because of your kindness.
Sincerely yours
A. R. Shaghaghian
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Received on Mon Jul 31 06:25:30 2000
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