Design of a Robust Globally Stabilizing PD-Process Control System

We discuss the global asymptotic stabilization of a continuous stirred chemical tank reactor, using linear time invariant PD-control with full state feedback. The control input is the feed temperature or the cooling temperature. The emphasis is placed on the robustness of the design, i.e. the controller globally stabilizes the system's set point without requiring the exact knowledge of the process parameters. The control parameters are tuned by means of a classical root locus analysis of the linearized closed loop dynamics and by simulations of the closed loop transients and phase portraits. The stabilization technique relies on the direct method of Liapunov.