执行器退化下反馈控制系统的寿命预测和延寿方法

在长期运行过程中,控制系统受到复杂工作环境的影响,执行器会发生不同程度损伤并导致其性能退化,进而致使反馈控制系统性能随之下降,甚至无法正常工作.因此针对执行器退化引起的系统性能恶化问题,建立了磨损和冲击共同作用的执行器复合退化模型,并采用基于失效时间的概率分布方法预测系统剩余寿命.然后,将执行器状态纳入控制器设计中,通过在线调整控制约束和修正设定值寻求系统性能与执行器健康指标之间的折衷平衡,以延缓执行器退化实现延长控制系统生命周期的目的.最后通过仿真案例验证了文中方法的有效性.

Research on life prediction and life extension method of feedback control system under actuator degradation

During long-term operation, the control system may be affected by complex working environment, the actuator may be damaged to varying degrees and its performance will be degraded, which will cause the performance of the feedback control system to drop or even not work properly. Therefore, in view of the deterioration of system performance caused by actuator degradation, this paper establishes a degradation model for the actuator that works under combinative action of wear and shock. The working condition of the actuator is incorporated in the controller design, and the method based on the probability distribution of failure time is employed to predict remaining life of the system. By adjusting control constraints and modifying set points on line, a trade-off between system performance and actuator health index is found to delay actuator degradation and extend the life cycle of the control system. Finally, the effectiveness of the proposed method is verified by simulated examples.