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Similarly, environmental requirements drive interest in aircraft structures in three basic directions. UA primarily intended for tactical use in the close vicinity of ground forces dedicated to force-protection missions will have modest requirements for systems redundancy. For UA intending to be certified to fly in civil airspace, the recognition of redundancy requirements is a factor for the development of systems and integration for the entire aircraft. This tends to drive up the scale of the aircraft and the structures needed to host capabilities and multiple systems needed to support larger scale performance for endurance, altitude and extended reliability. The need for a capability to operate and survive in high-threat areas adds the need for signature control, which becomes a consideration for structures planning.
. Wing. Keeping targets of intelligence interest under constant and persistence surveillance is increasingly valued by operational commanders. This, in turn, drives interest in wing designs that can bring the greatest possible measure of endurance to collection platforms. Technologies being investigated to increase wing performance include airfoil-shape change for multipoint optimization, and active aero elastic wing deformation control for aerodynamic efficiency and to manage structural loads. Research needs to be expanded in the area of Small Reynolds Number to improve the stability of small UA. This is especially true for the mini- and micro-UA classes using high aspect ratio wings. These platforms suffer lateral stability problems in even lightly turbulent air, which induces sensor exploitation problems and exacerbates the task of the aircraft/sensor operator. Research and development work with membrane wing structures appears to offer a passive mechanism to reduce
APPENDIX D – TECHNOLOGIES
Page D-6
the effect of small Reynolds Numbers on lateral stability. More work needs to be accomplished to expand this work to high aspect ratio wings.
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Apertures. The demand for increasingly sophisticated sensor and communications systems on airborne platforms continues to grow in the face of stringent space, weight and power (SWaP) constraints. This tension results in the desire to reduce the number of sensors and required antenna systems by combining functions and sharing components. Reducing costs and SWaP demands on platforms is key to controlling the size and costs of the sensors themselves. The importance of setting rigorous requirements to specify apertures is a factor in sizing the collection platform itself. A robust systems engineering regimen is required that recognizes the “function” required of the UA, and builds a “system,” rather than building a UA then trying to “shoe-horn” in a capability (e.g., if you want an ISR UA, start the design process as an ISR system, not a UA system). Consolidating capabilities on a single platform is envisioned in the multi-sensor command and control constellation (MC2C) program. The MC2C concept is, in effect, another means of aperture management. However, the constellation will include associated high- and low-altitude unmanned aircraft where collection systems can be integrated providing far more capability than any single platform. This also affords the opportunity to “net” multiple apertures from widely separated platforms into a single system bringing the attributes of ground-based multi-static systems into the airborne environment.
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无人机系统路线图 Unmanned Aircraft Systems Roadmap(137)
