HRA - Intrinsically fault tolerant actuation through high redundancy

The aim of this paper is to summarise on-going research into a new method of providing fault tolerant actuators for high-integrity and/or safety-critical applications. The High Redundancy Actuator (HRA) project aims to exploit a large number of very small actuation elements to make up a single large actuator. This is in contrast to current technology where a relatively low level of functional redundancy is used. The HRA elements are configured and controlled in such a way that faults in individual elements are inherently accommodated without resulting in a failure of the complete actuation system. The HRA project research challenges are outlined and progress to-date is discussed.