Gp. Reddy et M. Chidambaram, NONLINEAR CONTROL OF BIOREACTORS WITH INPUT MULTIPLICITIES IN DILUTION RATE, Bioprocess engineering, 12(3), 1995, pp. 151-155
Control problems of continuous bioreactors having two input multiplici
ties in dilution rate on the productivity are analyzed. The nonlinear
system is represented by a unity gain linear subsystem cascaded with a
nonlinear gain subsystem. A conventional PI controller designed for t
he linear subsystem followed by the solution of the nonlinear gain equ
ation gives a nonlinear controller. The performance of the nonlinear c
ontroller is compared with that of the conventional PI controller and
also of the nonlinear controller [1] designed based on the output equa
tion. The present nonlinear PI controller gives a superior performance
. A single set of controller settings can be used for both the operati
ng points. Whereas the linear PI controller and the nonlinear controll
er proposed by Henson and Seborg [1] destabilize the system.