Advanced Control of Dual Redundant Electro-Hydrostatic Actuator

状态监测和容错越来越重要，正在成为下一代计算机系统的基本要素。下一代产品，如未来的电动汽车和飞机，将更多地依赖于这些概念的安全性和可靠性。本文提出了三个新的相关贡献：一种新的鲁棒最优滤波器作为基于模型的状态监测的组成部分；将这种滤波器应用于一种新的容错控制形式；并将这些方法应用于一种新型电-静液作动系统。****新的滤波器将基于申请人开发的平滑变结构滤波器（SVSF）理论。SVSF是一种鲁棒滤波器，可用于状态估计和参数估计。与卡尔曼滤波等其他策略相比，它具有独特适用于状态监测的功能；它可以更好地适应被监测系统在性能和稳定性方面的不确定性。SVSF采用一阶滑模条件实现鲁棒稳定性，其原始形式不是最优的。在此建议下，基于二阶滑模条件的二阶SVSF将以获得既鲁棒又最优的滤波器为目标。这将对滤波领域作出实质性的理论贡献。****一般来说，现实世界的系统根据许多不同的操作机制（或模式）运行。一种能够跟踪动态系统模式变化的策略是交互多模型（IMM）概念。作为其实现的一部分，IMM需要一个过滤策略。在本研究中，二阶SVSF将与IMM相结合，以跟踪变化，从而作为增强状态监测策略的一部分。然后，将开发一种闭环控制策略，该策略将根据IMM识别的系统运行模式更新前馈补偿项，作为一种新的容错控制形式。***这些状态监测和控制策略将通过使用一种称为双冗余电-静液执行器（EHA）的新型驱动系统进行应用和验证。该执行器具有通过使用定制设计的组件来机械地重新配置自身的容错和故障预防能力。该系统的原型本身就是对流体动力工业的一项新贡献

Condition monitoring and fault tolerance are increasingly important and are becoming essential elements of next generation computerized systems. Next generation of products, such as future electric cars and aircraft, will more heavily rely on these concepts for their safety and reliability. This proposal makes three new related contributions that are: a new robust optimal filter as an integral element of model-based condition monitoring; use of this filter in a new form of fault tolerant control; and the application of these methods to a novel Electro-Hydrostatic Actuation System.****The new filter will be based on the Smooth Variable Structure Filter (SVSF) theory developed by the applicant. The SVSF is a robust filter that can be used for state and parameter estimation. It has features that are uniquely suitable for condition monitoring compared to other strategies such as the Kalman Filter; it can better accommodate uncertainties in the system that is being monitored both in terms of its performance and its stability. The SVSF uses the 1st order sliding mode condition to achieve robust stability and in its original form is not optimal. Under this proposal, a 2nd order SVSF based on the 2nd order sliding mode condition will be formulated with the objective of obtaining a filter that is both robust and optimal. This will constitute a substantive theoretical contribution to the field of filtering. ****In general, real-world systems behave according to a number of different operating regimes (or modes). A strategy that can track mode changes in dynamic systems is the Interacting Multiple Model (IMM) concept. As part of its implementation, the IMM requires a filtering strategy. In this research, the 2nd order SVSF will be combined with IMM to track changes and hence fault conditions as part of an enhanced condition monitoring strategy. A closed loop control strategy will then be developed with a feedforward compensation term that is updated according to the system's mode of operation as identified by the IMM, as a new form of fault tolerant control.***These condition monitoring and control strategies will be applied and validated by using a new actuation system referred to as the Dual Redundant Electro-Hydrostatic Actuator (EHA). This actuator has the ability to mechanically reconfigure itself for fault tolerance and failure prevention by using custom designed components. The prototype of this system is in itself a novel contribution to the fluid power industry.**