Abstract Each mixing valve is characterized by its kvs-value and the valve characteristics. In mounted condition, the valve characteristics are deformed and the degree of the deformation is determined by the valve authority. Considering already installed mixing valves, neither the valve authority nor the course of the undeformed valve characteristics are exactly known. The lack of information poses a challenge when physically modelling the relationship between the inlet temperatures, the control signal and the outlet temperature. Based on Bezier curves, a universal non-linear grey-box model to describe the thermal valve behaviour is proposed. It is compared with a state space as well as a Hammerstein model and shows the advantages over black-box approaches. The trained model is very robust, able to predict measurement data very accurately and can be used in control design. The parameter estimation is performed using the Open Source platform JModelica.org.

中文翻译：

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使用贝塞尔曲线对三通混合阀进行热建模，用于参数估计应用

摘要 每个混合阀都有其kvs值和阀门特性。在安装状态下，气门特性发生变形，变形程度由气门机构决定。考虑到已经安装的混合阀，无论是阀权还是未变形阀门特性的过程都不是很清楚。在对入口温度、控制信号和出口温度之间的关系进行物理建模时，信息的缺乏带来了挑战。基于贝塞尔曲线，提出了一种描述热阀行为的通用非线性灰盒模型。将其与状态空间以及 Hammerstein 模型进行比较，并显示出优于黑盒方法的优势。训练好的模型非常健壮，能够非常准确地预测测量数据，并可用于控制设计。参数估计是使用开源平台 JModelica.org 进行的。