一种诊断电动执行器恒增益故障的新方法

A New Method for Diagnosing Constant Gain Failures of Electric Actuator

针对电动执行器的恒增益故障难以诊断的情况,通过分析其主要组成部分变送器的工作原理,得出结论:变送器中电位器阻值的变化是导致执行器恒增益故障的主要原因。为确定电位器阻值设计了以伺服放大器专用调试实验箱为平台的试验电路,并由试验数据得到了电动执行器数学模型的拟和函数,为判断故障提供了依据。在此基础上,设计了实时测量并显示变位器阻值的电路,该电路可以测量2000■以内的电阻阻值,并且实现简单、实时性能好,为迅速诊断和排除电动执行器的恒增益故障节省了时间。

Due to the difficulty in the diagnosis of constant gain failure of electric actuator, by means of analyzing the working principle of transducer that is the principal component of actuator, it is discovered that the resistance value variation of varistor is the main reason causing constant gain failure of electric actuator. To determine the resistance value of varistor a testing circuit in which a special testing box for the debugging of servo-amplifier is taken as the testing platform, and the fitting function of the mathematical model for electric actuator is obtained from testing data, thus the foundation for the judgment of constant gain failure is acquired. On this basis, to measure the resistance values of the varistor in real-time way and display the measured values, a testing circuit, whose measurable resistance value is up to 2000 ohm, is designed. This testing circuit is easy to implement and possesses good real-time performance. By use of the presented circuit, the time for trouble shooting of constant gain failure of electric actuator can be saved.