Dual redundant electrohydraulic actuation system

在过去20年里，北美运输业痛苦地认识到，可靠性是其市场领域的关键成功标准。丰田在汽车行业的增长和麦克唐纳·道格拉斯在航空航天领域的消亡证明了可靠性在赢得/失去市场份额方面的重要性。在过去的两年里，丰田已经成为世界上最大的汽车制造商，因为它建立了自己生产可靠、价格有竞争力的汽车的声誉；另一方面，麦克唐纳·道格拉斯在20世纪90年代中期被波音航空航天公司收购，其商业航空产品线实际上由于一些飞机的可靠性问题而解散。其他制造商也逐渐意识到并体验到在他们的商业运营中需要产品可靠性；福特就是一个明显的例子。可靠的系统可以被视为故障较少且按照预期规范运行的系统。归根结底，系统的可靠性是通过设计实现的；然而，影响整体可靠性感知的另一个同样强大的因素是预测和防止非计划维护故障的能力，以确保运行可靠性；这对涉及大规模生产或运输的行业尤其重要。此外，防止故障将对安全性、运营成本、客户满意度以及最终的市场份额产生非常有利的影响。预测和健康监测系统(PHMS)是用于检测、预测和跟踪故障状况的高级工具。这项建议涉及开发一种扩展形式的PHMS，它将能够在故障发生之前诊断故障条件和预测故障条件。该系统将基于申请人提出的被称为平滑变结构滤波器(SVSF)的新理论。它将在一个由申请人广泛研究的驱动系统上进行测试，该系统被称为电液致动器(EHA)，这是航空航天部门非常感兴趣的。

In the past two decades, it has become painfully clear to the North American transportation industries that reliability is a key success criterion in their market sector. The growth of Toyota in the automotive sector and the demise of McDonald Douglas in the aerospace are testimonies to the importance of reliability in gaining/losing market share. In the past two years, Toyota has become the largest car manufacturer in the world by establishing itself a reputation for producing reliable cars that are competitively priced; McDonald Douglas on the other hand was taken over by Boeing Aerospace in the mid 1990s and its commercial-airline product-line virtually disbanded due to reliability problems with some of their aircraft. Other manufacturers have also come to appreciate and experience the need for product reliability on their business operations; Ford is a notable example. A reliable system can be viewed as one that has fewer breakdowns and operates according to an expected specification. Ultimately, reliability in a system is achieved by design; nonetheless, an equally strong factor that influences the overall perception of reliability is the capability of predicting and preventing failures by unscheduled maintenance to ensure operational reliability; this being particularly important to industries involved in mass production or transportation. Furthermore, preventing failures will have a very favorable impact on safety, operating costs, customer satisfaction, and ultimately market share. Prognostics and Health Monitoring Systems (PHMS) are advanced tools that are used for the detection, prognosis, and tracking of faults conditions. This proposal pertains to the development of an extended form of PHMS that will be capable of the diagnosis of fault conditions and the prediction failure conditions before their occurrence. This system will be based on a new theory proposed by the applicant referred to as the Smooth Variable Structure Filter (SVSF). It is to be tested on an actuation system that has been extensively researched by the applicant referred to as the ElectroHydraulic Actuator (EHA) that is of considerable interest to the aerospace sector.