Flatness-based feedforward control design and two-degrees-of-freedom tracking control for semilinear plug flow reactors

Flatness-based feedforward control design for semilinear plug flow reactors is considered in combination with an easily tunable PI controller to achieve the tracking of desired output trajectories. The approach is based on a subdivision of the relevant time-space region along the characteristic curves of the underlying partial differential equations and a parameterization of the solution in terms of summable formal power series. An approximation for the solution is retrieved by applying an adequate summation method to the power series. Simulations illustrate the applicability of the approach to achieve finite time transitions between operating points along prescribed transient paths and its robustness with respect to uncertainties in the parameters of the reactor.