Research On Real-time Stability-margin-oriented Fault Tolerant Control

This paper focus on the stability-margin-oriented data-driven active fault-tolerant control method.As an evaluation index of closed-loop system,stability margin can quantitatively measure the "degree" of stability of the closed-loop system.Therefore,stability margin can be used to measure the robustness of the system.Motivated by these facts,this study focus on the improvement of the control performance of the closed-loop system by improving the stability margin when the robustness deteriorates due to unknown faults in the system.In order to optimize the stability margin of the system without breaking the original closed-loop,the Plug-and-Play Process Monitoring and Control Architecture is constructed by Youla parameterization method and its dual form.On the premise of maintaining the original control device,this architecture can improve the control performance by adding additional control signals into the original control system.Through the online optimization algorithm of Youla parameter matrix given in this paper,the work of this paper achieves the effect of active fault-tolerant control of the system.Furthermore,if the original control effect needs to be restored,it can be realized by simply "unplug" the additional input module,a low-cost fault-tolerant control solution is thus provided to ensure the stability and security of the system.In order to avoid the process of system identification and modeling during optimization,data-driven method is adopted for stability margin estimation and optimization.Firstly,the stability kernel/image description of the data-driven system is obtained by subspace method.Based on this,the stability margin of the standard closed-loop system and fault tolerant control architecture is estimated offline and online.After obtaining the stability margin,the Youla parameter matrix is optimized online by using Gauss-Newton method and data-driven technology,which improves the stability margin of the system and achieves the effect of active fault-tolerant control.