飞机热交换器故障诊断研究

On Fault Diagnosis of the Heat Exchangers of an Aircraft Environment Control System

针对飞机环境控制系统中的关键部件——热交换器作为研究的对象,对环境控制系统的热交换器模型和不确定性进行了分析,建立了含有待定参数和不确定性的数学模型。对模型中的待定参数采用最小二乘法进行了估计;在此基础上,对不确定模型采用鲁棒估计的方法进行系统的故障诊断,结果表明该方法是可行的。

Among the various fault modes of an aircraft environment control system, the fault modes of the heat exchangers are the most complicated. We present a method for fault diagnosis of aircraft heat exchangers by robust estimation method. We first established the mathematical model of an aircraft heat exchanger with its uncertainties considered. Then we use the least square method to identify the model parameters. Due to the uncertanities of the model and the inaccuracy of parameter identification, we use robust estimation method for detection of the residue in fault diagnosis in order to avoid false-alarm or failto-alarm. Simulations and field tests are performed to verify our method. Results show that robust estimation method is more effective than conventional methods for detection of faults when there are uncertainties in the system model.