Multivariable Decoupling Compensator for a Tank Level Control

As multivariable systems are usually quite complex some possible simplifications of nonlinear model of three coupled tanks are presented in the paper. Well known decoupling method is combined with classical design and finally improved with so called conditioned technique which can always be realised if decoupling is possible. The simplification is so dual. This approach enables the use of design methods for univariable systems but can also be very helpful when switching between automatic and manual control is needed, especially when combined with anti-windup method known as conditioned technique. We believe that in process industry there are many cases where this solution can be successfully used. Some other possibilities still under development are also indicated