A new active fault tolerant control scheme based on active fault diagnosis is proposed to address the component/actuator faults for systems with state and input constraints. Firstly, the active fault diagnosis is composed of diagnostic observers, constant auxiliary signals, and separation hyperplanes, all of which are designed offline. In online applications, only a single diagnostic observer is activated to achieve fault detection and isolation. Compared with the traditional multi-observer parallel diagnosis methods, such a design is beneficial to improve the diagnostic efficiency. Secondly, the active fault tolerant control is composed of outer fault tolerant control, inner fault tolerant control and a linear-programming-based interpolation control algorithm. The inner fault tolerant control is determined offline and satisfies the prescribed optimal control performance requirement. The outer fault tolerant control is used to enlarge the feasible region, and it needs to be determined online together with the interpolation optimization. In online applications, the updated state estimates trigger the adjustment of the interpolation algorithm, which in turn enables control reconfiguration by implicitly optimizing the dynamic convex combination of outer fault tolerant control and inner fault tolerant control. This control scheme contributes to further reducing the computational effort of traditional constrained predictive fault tolerant control methods. In addition, each pair of inner fault tolerant control and diagnostic observer is designed integratedly to suppress the robust interaction influences between estimation error and control error. The soft constraint method is further integrated to handle some cases that lead to constraint violations. The effectiveness of these designs is finally validated by a case study of a wastewater treatment plant model.

中文翻译：

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基于主动故障诊断和插值优化的约束主动容错控制

针对具有状态和输入约束的系统，提出了一种新的基于主动故障诊断的主动容错控制方案来解决组件/执行器故障。首先，主动故障诊断由诊断观测器、恒定辅助信号和分离超平面组成，所有这些都是离线设计的。在在线应用中，仅激活单个诊断观察器即可实现故障检测和隔离。与传统的多观察者并行诊断方法相比，这种设计有利于提高诊断效率。其次，主动容错控制由外容错控制、内容错控制和基于线性规划的插补控制算法组成。内部容错控制是离线确定的，满足规定的最优控制性能要求。外部容错控制用于扩大可行域，需要与插值优化一起在线确定。在在线应用中，更新的状态估计会触发插值算法的调整，进而通过隐式优化外部容错控制和内部容错控制的动态凸组合来实现控制重构。这种控制方案有助于进一步减少传统约束预测容错控制方法的计算工作量。此外，每对内部容错控制和诊断观测器都被集成设计，以抑制估计误差和控制误差之间的鲁棒交互影响。进一步集成软约束方法来处理一些导致违反约束的情况。这些设计的有效性最终通过污水处理厂模型的案例研究得到验证。