Adaptive robust control of a Chinese medicine sugar precipitation process

A model dedicated to Chinese medicine sugar precipitation is designed, without consideration of crystal size distribution. Adaptive robust control algorithm is provided for the uncertain nonlinear system based on Lyapunov´s stability theory. The mechanism is based on “model decomposition”: adaptive controller is adopted to eliminate the parameter uncertainty; robust controller is adopted to attenuate the unknown dynamics and disturbance; feedback controller is developed to dominate the nominal plant. Three controllers compose the integrated controller for the uncertain nonlinear system. The stability is demonstrated and the output of system tracks the set point well. The algorithm is implemented to the sugar precipitation control of Chinese medicine solution. Simulation result assists the validity of the proposed algorithm.