舵机特征模型及其故障检测方法

Characteristic model-based approach for actuator fault diagnosis

舵机故障诊断对于提高飞行安全十分重要,传统方法面临着载荷时变不确定及自身存在速率饱和非线性等难题,往往会给诊断结果带来影响,导致虚警。为解决该问题,提出了一种舵机特征模型及其故障检测方法。首先根据舵机通频带和饱和速率2个外特性建立诊断用特征模型,然后采用状态观测器计算舵机转速和位置的响应参考值,最后根据转速和位置实际值与参考值的残差是否超过预设阈值来判断舵机的电机和驱动器是否发生故障。该方法可以有效避免因舵机载荷不确定及自身速率饱和所引起的虚警,同时,由于特征模型仅与通频带及饱和速率有关,故该方法具有简单、实用性强等显著优点。

Actuator fault diagnosis is very important to improve flight safety.Nevertheless,some nonlinear problems in classical approaches such as load time variability uncertainty and rate saturation etc.will affect the diagnosis,resulting in false alarm.This paper presents a characteristic model-based fault detection method for actuator to solve the problems.Firstly,a characteristic model used in diagnosis is established according to the bandwidth and the rate saturation of the actuator.Then,the reference responses of the velocity and displacement are calculated with state estimators.Lastly,judging by whether the residuals between the practical velocity or displacement and the references exceed the given thresholds or not,failures in motors or drives can be easily detected.This approach can avoid the false alarm caused by load uncertainty or rate saturation effectively,and the characteristic model,only related to the actuator bandwidth and rate saturation,is provided with the significant advantages of simplicity and practicability.