基于表达式树的Modelica单位检查和推导

针对多领域物理系统统一建模中，提高复杂模型的质量与可靠性的迫切需求，阐述了Modelica语言对单位的支持方式以及单位之间换算和运算的规则，并基于对表达式树的遍历操作，给出了单位检查与推导机制的实现方案。通过分析该方案的时间复杂度，针对其影响效率的主要因素进行了优化。最终将该方案在多领域统一建模仿真平台MWorks上得以实践，以Modelica标准库中的模型为实例，证明了方案的可行性。

Unit check and derivation in Modelica based on expression tree

For the requirements to improve the quality and reliability of the complex models in multi-domain physical system modeling, the rules of conversion between the Modelica units are expounded clearly. Based on the expression tree traversal, the implementation scheme that aim at the mechanism for checking and deducing units is given. By analysing the time complexity of the scheme, the main factors affecting the efficiency are optimized. And this scheme is implemented on MWorks, which is a multi-domain physical system modeling platform. It is proved that the scheme is effective by an example from the Modelica standard library.