Robust Global Stabilisation of Stirred Tank Reactors by Saturated Output Feedback

摘要

This paper is concerned with the robust stabilisation of a wide class of unstable processes operated in continuous stirred tank reactors. For non-isothermal reactors, the regulated output is the temperature. For isothermal reactors, the regulated output is the single concentration of either an initial reactant or a final product. In both cases the proposed control law is a dynamic output feedback which can be interpreted as a straighiforward modification of a standard PI controllet in accordance with the engineering constraints, the control action is positive and saturated. With this control law, it is shown that the output variable may be regulated at a prescribed set point despite a wide kinetic uncer- tainrt. Furthermore, the controller achieves a global stabilisation of the process in its domain of physical existence. When the reactor is minimum phase, The closed loop has a single equilibrium which is glo- bally asymptotically stable. When the reactor is non- minimum phase, a global practical output regulation with state boundedness is obtained with the same controller.