Liu Hesheng

Prediction of supercritical carbon dioxide solubility in polymers based on hybrid artificial intelligence method integrated with the diffusion theory

Solubility is one of important research hotspots of physical chemistry properties and is widely utilized in the modification, synthesis and preparation of a lot of materials. To avoid the defects of traditional thermodynamic dissolution forecasting methods, according to the mass transfer features of a two-phase system, the dissolution process is simulated. In this paper, the diffusion theory is integrated into the improvement of particle swarm optimization (PSO) so that the particles in the algorithm evolve along with the diffusion energy. In this way, the improved PSO of dual-population diffusion is obtained and used to train the parameters of the radial basis function artificial neural network. Then, a prediction model for supercritical carbon dioxide solubility in polymers is proposed. The solution experiments of 8 polymers indicate that the predicted values with the model are consistent with the experimental results. The prediction accuracy is higher and the correlation is significant. The average relative error, mean square error and square correlation coefficient are respectively 0.0043, 0.0161, and 0.9954. The prediction model has a high comprehensive performance and provides the basis for the prediction, analysis and optimization of other physical and chemical fields.

Controller Design for Constant Air Pressure

Air supply is very important in coal mine, but it is difficult to maintain proper air pressure for reason of non-linear and large time-delay of air supplying system. A hybrid controller combined Fuzzy-PID and Smith predictive model is proposed after careful analysis, the controller can compensate large delay time and change the big delay time into small one, can adjust PID parameters online by Fuzzy logic. simulation indicates that its tracking precision and converging speed are high, ability of fitting model mismatch is strong, practical results demonstrate that it works better than segment PID, Variation of air pressure is limited into a range of ±2KPa.