摘要：为提高应用于运载火箭上无刷直流电机伺服机构安全性与可靠性，提出一套基于无刷直流电机控制的三余度机电伺服机构，并对其进行数学建模和仿真研究。设计三选二多数表决的控制策略，对输入和反馈信号进行表决；设置故障检测和隔离，检测电机相电流并进行逻辑判断，将故障通道隔离。研究表明，采用三冗余设计使伺服机构在一度故障时能够隔离故障通道，保证伺服机构正常工作，提高了伺服机构的可靠性。

关键词：伺服机构；三余度；建模仿真；多数表决
Abstract: To improve the application on the rocket tributary brushless motor servo security and reliability, This paper presented a set of treble-redundancy of brushless DC motor control mechanical and electrical servo mechanism, its mathematical modeling and simulation were researched. The system designed three choose two majority voting control strategy and voted on input and feedback signal. By setting the fault detection and isolation, it detected the motor phase current and logical judgment and isolated fault channel. Studies show that the system is able to isolate fault channels and by using this control strategy, the reliability of the servo mechanism is improved.

Key words: servo mechanism; treble-redundancy; modeling and simulation; majority voting