The design and development of a novel strapdown DTG incorporating a gas bearing and fabricated flexure hinge

The incorporation of self-acting gas lubricated spin bearings into Dynamically Tuned Strapdown sensors has not previously been possible because of the mutually conflicting requirements of these otherwise proven technologies. This paper describes how the many technical problems have been overcome by Smiths Industries in the Series 2000 DTG, and discusses the technology required to realize the design. In addition to its gas bearing, the Series 2000 DTG design incorporates many other unique features, including a fully fabricated flexure hinge, a high performance spin motor and a symmetrical modular construction. Thermal and magnetic design have received particular attention and the techniques employed are also outlined. The advantages of a gas bearing DTG in terms of performance, storage life, MTBF and ready time are discussed and typical performance data for the Series 2000 DTG presented. In-run drifts around 0.1 deg/h and capture rates exceeding 400 deg/s have been achieved. Projected applications include airborne, missile, underwater and surface systems, where the inherent features of a gas bearing can be used to considerable advantage.