基于直接冗余的轮控系统故障诊断及优化配置

Fault Diagnosis and Optimizing Configuration of Flywheels Based on Direct Redundancy

闭环控制系统中的故障检测与诊断是目前卫星控制工程上急需解决的问题之一。由于故障传播等原因的影响 ,闭环系统中某一执行机构故障会对其它正常执行机构输出造成影响 ,因此很容易产生误判。轮控系统是卫星控制系统长期轨道运行模式中的主要执行部件 ,由于不断作机械运动 ,难免发生故障 ,若不及时处理 ,会给飞行任务带来严重影响。文章介绍了一种基于直接冗余的飞轮故障检测与隔离方法 ,对于冗余配置轮控系统 ,每个飞轮的力矩控制信号是按照飞轮的配置结构对三轴所需控制力矩进行分配而得到的 ,因此当飞轮工作正常时 ,飞轮的输出 (转速变化率 )之间会存在一致性。一旦这种一致性被破坏 ,即说明某一个飞轮发生故障 ,就要对其进行隔离。这种方法不需要对每个飞轮的力矩控制信号进行积分 ,减小了计算量。仿真结果验证该方法能够实时检测渐变故障 ,且不受闭环系统故障传播的干扰。

Fault detection and diagnosis of closed loop control system is one of the problems in urgent need of solving in satellite control engineering. Fault of one actuator in closed loop system will affect the outputs of other normal actuators because of fault propagation. Flywheels are main actuators of satellite control system in long term orbitmove mode and faults are unavoidable owing to their continuous mechanical movement. The fault would have a strong impact on the satellite if it can not be detected and isolated in time. This paper presented a fault detect and isolate method based on the direct redundancy of flywheels, its basic idea is that there exists consistency of the flywheels′ outputs (change rate of rotation rate) in redundant configuration flywheels system, and inconsistency in the measured rotation rates is then ametric that can be used for detecting faults and subsequently for fault isolation. This method didn′t need to integrate the torque control command of every flywheel and reduced calculation amount. Simulation results showed that this method could detect and isolate incipient fault in real time. At last we made optimizing configuration analysis of the direct redundant flywheels from the fault detect performance point of view.