Advanced Control of Dual Redundant Electro-Hydrostatic Actuator

状态监测和容错越来越重要，并且正在成为下一代计算机化系统的基本要素。下一代产品，如未来的电动汽车和飞机，将更加依赖这些概念的安全性和可靠性。该建议提出了三个新的相关贡献是：一个新的鲁棒最优滤波器作为一个不可分割的元素，基于模型的状态监测;使用这种过滤器的一种新形式的容错控制;和这些方法的应用到一个新的电液致动系统。 新滤波器将基于申请人开发的平滑可变结构滤波器（SVSF）理论。SVSF是一种鲁棒滤波器，可用于状态和参数估计。与其他策略（如卡尔曼滤波器）相比，它具有独特的适用于状态监测的功能;它可以更好地适应系统中的不确定性，无论是在性能还是稳定性方面。SVSF使用一阶滑模条件来实现鲁棒稳定性，并且其原始形式不是最优的。在此建议下，二阶SVSF的基础上的二阶滑模条件将制定与获得的过滤器，这是强大的和最佳的目标。这将构成过滤领域的实质性理论贡献。 一般来说，现实世界的系统根据许多不同的操作制度（或模式）来运行。可以跟踪动态系统中的模式变化的策略是交互式多模型（IMM）概念。作为其实现的一部分，IMM需要过滤策略。在这项研究中，二阶SVSF将与IMM相结合，以跟踪变化，因此故障条件作为增强的状态监测策略的一部分。闭环控制策略，然后将开发一个前馈补偿项，更新根据系统的操作模式所确定的IMM，作为一种新的形式的容错控制。 这些条件监测和控制策略将被应用和验证，通过使用一个新的驱动系统称为双冗余电液致动器（EHA）。该执行器能够通过使用定制设计的组件进行机械重新配置，以实现容错和故障预防。该系统的原型本身就是对流体动力工业的一个新贡献。

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.