Dual redundant electrohydraulic actuation system

在过去的二十年里，北美运输行业已经痛苦地认识到，可靠性是其市场领域成功的关键标准。丰田在汽车领域的成长和麦克唐纳道格拉斯在航空航天领域的消亡都证明了可靠性在获得/失去市场份额中的重要性。在过去的两年里，丰田凭借生产可靠、价格有竞争力的汽车而赢得了声誉，成为世界上最大的汽车制造商；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公司收购，由于一些飞机的可靠性问题，其商业航线产品线实际上已经解散。其他制造商也开始认识到并体验到产品可靠性在其业务运营中的必要性；福特就是一个显著的例子。一个可靠的系统可以被看作是一个有较少的故障，并根据预期的规格操作。最终，系统的可靠性是通过设计实现的；尽管如此，影响可靠性整体感知的一个同样强大的因素是通过计划外维护来预测和防止故障的能力，以确保运行可靠性；这对涉及大规模生产或运输的行业尤为重要。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先进工具。该建议涉及开发一种扩展形式的PHMS，该PHMS将能够诊断故障条件并在故障发生之前预测故障条件。该系统将基于申请人提出的称为平滑变结构滤波器（SVSF）的新理论。它将在一个驱动系统上进行测试，该驱动系统已被申请人广泛研究，称为电液执行器（EHA），这是航空航天部门相当感兴趣的。

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.