基于键合图的空气制动机建模方法研究

Research on Modelling Method of Air Brake Based on Bond Graph

为了更好地揭示空气制动机各子系统之间的耦合关系,真实地描述其瞬时离散特性,以120型空气制动机为例,在键合图理论的基础上引入MA(Model Approximation)法建立120型空气制动机的数学模型。分析各子系统的工作原理,运用可控结点和虚拟元件仿真模拟子系统的离散特性,建立具有统一因果关系的键合图模型;通过分析各子系统之间的相互作用关系,根据功率流传递路径,建立120型空气制动机的键合图模型。以120阀机后起"非常"现象为案例进行仿真分析。结果表明:仿真结果和试验结果吻合,证明建立的模型能够真实反映120型空气制动机的工作特性,为空气制动机的性能评估和优化设计提供了一个新的途径。

A model 120 air brake was taken as an example to build the mathematic model based on bond graph and model approximation in order to reveal the coupling relationship between each subsystem and analyze the instantaneous discrete characteristics of the air brake.Firstly,the bond graph model of subsystem was built with uniform causality by the introduction of the controllable node and virtual element to simulate the discrete characteristics of subsystems after the analysis of the working principle of the model 120 air brake.According to their interaction relationship and the power flow transmission between subsystems,the bond graph model of the model 120 air brake was established.A simulation was conducted on an undesirable emergency braking.The results show that the good agreement of simulation results with test data verifies the applicability and accuracy of bond graph model of 120 air brake,which provides a new method for the performance evaluation and optimization design of air brake.