Hybrid modeling based on structural separation and parameter separation

作者：Cao Liulin^*; Liu Hua; Wang Jing; Wu Haiyan

来源：Journal of Harbin Engineering University, 2012, 33(9): 1194-1198.

DOI：10.3969/j.issn.1006-7043.201009034

• Arrhenius-function
• Continuous-flow stirred tank reactors
• Hybrid model
• Hybrid modeling
• Identification approach
• Least square methods
• Linear functions
• Petrochemical industry
• Prior knowledge
• Prototype system
• Training time

For the purpose of modeling complex systems, a new hybrid modeling method based on structural separation and parameter separation was presented in consideration of the continuous-flow stirred tank reactor (CSTR) which is widely used in the petrochemical industry. The concept behind this method is making full use of the system';s prior knowledge, and maintaining the known structure and parameter of the system to the utmost so that the hybrid model can approximate the prototype system from the inside to the outside. After the structure of the nonlinear system was decomposed, the modeling was divided into two steps. First, the Arrhenius function in a reaction rate equation was converted into a linear function through a logarithm transform, and then the unknown parameters could be fitted by the least square method, which is convenient and effective. Here only the unknown parameters in the linear part were identified; in this way not only the training time can be shortened, but also the reliability and generalization of the models can be guaranteed by enhancing the model';s grey-box-property. The new methods were compared with the conventional all-parameters identification approach in this paper; the results show the effectiveness and feasibility of the presented methods.

• 出版日期2012
• 单位北京化工大学