基于键合图模型的SHA/EMA余度系统的故障诊断

针对液压伺服作动器（SHA）和机电作动器（EMA）组合的余度系统中故障模式复杂的问题，采用基于键合图模型的故障诊断方法，可以诊断出系统中多种参数故障。首先建立SHA/EMA余度系统的行为模型，然后根据因果关系倒置法转换成诊断键合图模型，进而推导出计算残差的解析冗余关系式（ARR），并创建故障特征矩阵（FSM）作为故障隔离的依据。联立行为模型和诊断模型对可隔离故障进行诊断，并通过ARR估计故障参数以诊断不可隔离故障。选取典型故障进行仿真验证，结果表明可隔离故障和不可隔离故障均被成功隔离，验证了所提方法对SHA/EMA余度系统的故障诊断是有效可行的。 

Fault diagnosis for SHA/EMA redundant system based on bond graph model

For the complex fault modes in the redundant system composed of servo-controlled hydraulic actuator (SHA) and electromechanical actuator (EMA), the fault diagnosis method based on bond graph model can be used to diagnose many parameter faults in the system. Firstly, the behavioral model of SHA/EMA redundant system was established, from which the diagnostic bond graph model was transformed according to the causality inversion method, and then the analytical redundancy relation (ARR) was derived to calculate system residuals, and the fault signature matrix (FSM) was created as a basis for fault isolation. Several typical faults were selected for simulation verification. Behavioral model and diagnostic model were coupled to diagnose isolated faults, and fault parameters were estimated through ARR to diagnose inseparable faults. The results show that both isolated and inseparable faults are successfully isolated, and this method is verified to be effective and feasible for fault diagnosis of SHA/EMA redundant system.