Variable Structure Control of Polysaccharide Precipitation in Chinese Medicine Solution Based on Recurrent CMAC

Variable structure control with recurrent cerebellar model articulatory controller (CMAC) is proposed and applied to a polysaccharide precipitation process of Chinese medicine solution. A kinetics model dedicated to the stage precipitation is designed. The control system concludes nominal model and lumped perturbance term which is composed of modeling error, parameter uncertainties, disturbances, and unmodeled dynamics. Variable structure control is adopted to approximate the tracking errors of the uncertain system. Because the threshold value of lumped perturbance is difficult to measure in practical applications, the recurrent CMAC is used as an observer to approximate it in real time. The performance of the proposed control strategy, which is applied to polysaccharide precipitation control in ophiopogon japonicas solution, is tested via simulation in cases of set point tracking. The results indicate that research conclusion provides the basis for effective control of complex system.