基于观测器的航天器执行机构故障诊断与容错控制技术研究

发布时间：2018-09-12 11:09

【摘要】：随着航天技术的发展,在轨运行航天器的任务变得愈发复杂,航天器发生故障的概率随之增大,在故障诊断技术的研究中,大多是利用系统的状态残差进行诊断,这种诊断方法的正确性基于设定的阈值,此值的设定较为复杂,影响了故障诊断的准确性,基于此,本文应用故障重构的思想进行故障诊断技术研究,并利用重构的故障进行容错控制设计。本文首先对姿态控制系统的建模问题进行了研究,明确了闭环姿态控制系统的设计方法以及敏感器和执行器的工作原理,建立了反作用飞轮的动力学模型,并基于此模型,讨论研究了比例微分控制器和滑模控制器的设计方法,为故障诊断和容错技术的研究奠定了基础。其次研究了基于观测器的故障重构方法,在精确观测系统状态的前提下,利用观测器的输出部分实现故障重构,采用两种方法,一种是基于滑模观测器,采用自适应律补偿系统参数的干扰,利用滑模部分实现故障的重构,此方法在故障诊断时存在一定的时间延迟现象;另一种是基于未知输入观测器,采用未知输入和故障解耦技术,实现两者的解耦设计,并对两者进行重构设计,此方法在设计过程中降低了观测器的维数,在工程上易于实现。对于这两种方法,论文基于Lyapunov理论分别给出了稳定性证明。从仿真结果来看,观测器实现了状态的精确观测,对于飞轮突发性故障和间歇性故障,两种观测器都实现了故障的重构,且精度较高。最后,本文研究了基于伪逆法的容错控制方法,同时给出了稳定性证明,对于飞轮发生的间歇性故障,即飞轮的输出力矩有一个偏差,在故障精确重构的前提下,利用附加的控制律实现故障信息的补偿,实现故障调节,仿真结果表明,由于控制律的调节作用,虽然姿态角仍有偏差,但偏差已经很小,这说明该方法对于间歇性故障有很好的容错效果。
[Abstract]:With the development of spaceflight technology, the mission of orbiting spacecraft becomes more and more complex, and the probability of spacecraft failure increases. In the research of fault diagnosis technology, the state residuals of the system are mostly used to diagnose. The correctness of this method is based on the threshold value, which is more complex and affects the accuracy of fault diagnosis. Based on this, this paper applies the idea of fault reconstruction to study the fault diagnosis technology. The fault tolerant control is designed by using the reconfigurable fault. In this paper, the modeling of attitude control system is studied, the design method of closed loop attitude control system and the working principle of sensor and actuator are defined, and the dynamic model of reaction flywheel is established based on this model. The design methods of proportional differential controller and sliding mode controller are discussed, which lays a foundation for the research of fault diagnosis and fault-tolerant technology. Secondly, the fault reconstruction method based on observer is studied. On the premise of observing the state of the system accurately, the output part of the observer is used to realize the fault reconstruction. Two methods are adopted, one is based on sliding mode observer, the other is based on sliding mode observer. The adaptive law is used to compensate the disturbance of system parameters, and the sliding mode part is used to reconstruct the fault. This method has a certain time delay phenomenon in fault diagnosis, the other is based on unknown input observer. The decoupling design of unknown input and fault decoupling is realized, and the reconfiguration design of both is carried out. This method reduces the order of the observer in the design process and is easy to be realized in engineering. For these two methods, the paper gives the proof of stability based on Lyapunov theory. From the simulation results, the observer realizes the accurate observation of the state, for the flywheel sudden fault and intermittent fault, the two observers achieve fault reconstruction, and the accuracy is high. Finally, the fault-tolerant control method based on pseudo-inverse method is studied, and the stability proof is given. For the intermittent fault of flywheel, that is, the output torque of flywheel, there is a deviation under the premise of accurate fault reconstruction. The additional control law is used to compensate the fault information and realize the fault regulation. The simulation results show that the attitude angle is still deviated, but the deviation is very small, because of the adjusting effect of the control law. This shows that the method has a good fault tolerance effect for intermittent faults.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：V467

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