An optofluidic control system for tactical missiles and guided munitions

Benson, Dewey; Aerospace, AlliedSignal; Ryan, Bill C.; Drzewiecki, Ted

doi:10.2514/6.1997-3834

Cited by 2 publications

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“…Although there is no great certainty of the exact management regimes used by the Aboriginal people, it is known that patch burning, hunting and digging were relatively common human-induced disturbances in lowland grassy woodlands (e.g. Clark and McLoughlin 1986;Benson and Redpath 1997;Kirkpatrick 1999). Today, the most widespread management regime involves grazing by domestic stock and some native vertebrates, and infrequent fire (Gilfedder and Kirkpatrick 1995).…”

Section: Introductionmentioning

confidence: 99%

Vegetation change in an urban grassy woodland 1974 - 2000

Kirkpatrick¹

2004

Aust. J. Bot.

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Few temporal studies document vegetation change in Australian temperate grassy woodlands. Floristic and structural data were collected from 68 randomly located sites in the Queens Domain, an urban grassy woodland remnant, in 1974, 1984, 1994 and 2000 and a search made for rare species. Species of conservation significance were concentrated at highly disturbed sites, whereas vegetation types of conservation significance decreased in area as a result of increases in the numbers of Allocasuarina verticillata, which caused a change in many unmown areas from Eucalyptus viminalis grassy woodland to E. viminalis–A. verticillata woodland/forest or A. verticillata open/closed forest. Structural changes were associated with changes in species composition and an increase in native-species richness. Increases in tree cover occurred where fires were most frequent, possibly as a result of the lack of mammalian herbivores. The frequencies of herbs and annual grasses were strongly affected by precipitation in the month of sampling. Half of the species that showed a consistent rise or fall through time were woody plants, approximately twice the number expected. In the dataset as a whole, species-richness variables were largely explained by varying combinations of variables related to moisture availability, altitude and the incidence of mowing. The strongest influences on species composition were the same, although slope and time since the last fire also contributed to multiple regression and generalised linear models. Compositional stability was positively related to native-species richness, whereas high levels of exotic-species richness occurred at both low and high levels of native-species richness. The maintenance of native-plant biodiversity on the Domain requires such counterintuitive measures as the maintenance of exotic trees and the control of native trees, demonstrating the contingencies of conservation management in fragmented vegetation that consists of a mixture of native and exotic species.

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Section: Introductionmentioning

confidence: 99%

Vegetation change in an urban grassy woodland 1974 - 2000

Kirkpatrick¹

2004

Aust. J. Bot.

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“…Long used as an infrared means of gas detection and the subject of Thomas Edison's photophone the tones developed by an absorbing surface in response to pulsed optical energy can be detected and processed by acousto-fluidic circuits. The fact that optical fibers can be used to transmit light can form the basis for on-chip opto-fluidic processing as was demonstrated by the control of guided projectiles flying with an optical fiber tether and an all-fluidic pneumatic control system getting its multi-axis guidance information via multiplexed multi-wavelength laser signals up a single fiber (Benson et al 1997). Tippetts (1996) describes a fiber-optic-to-pneumatic valve controller using the photo-acoustic effect.…”

Section: Future Possibilitiesmentioning

confidence: 99%

Fluidic technology: adding control, computation, and sensing capability to microfluidics

Drzewiecki¹,

Macia

2003

SPIE Proceedings

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This paper presents an overview of fluidic technology -a technology that provides an additional dimension to conventional microfluidic technology by adding sensing, computation (both analog and digital) and control. The US Army Diamond Ordnance Fuze Labs officially recognized fluidics as a comprehensive technology comparable to electronics with its announcement in 1959. Because fluidic elements have very few or no moving parts the technology provides significant operational advantages in harsh environments (EMI, radiation, high temperature and vibration). It also offers advantages when dealing with fluid variables (flow, pressure, density, viscosity, etc.) by eliminating the need for interfaces. With the elimination of the inertia and friction associated with moving parts there are even greater advantages as a result of the higher speed of operation. Where mechanical and micromechanical devices may be limited to only hundreds of hertz true microfluidic systems can operate at tens of thousands of hertz. We discuss the fundamental principles of jet deflection amplification and vortex modulation and present circuit building blocks such as the laminar proportional amplifier, vortex valve, oscillators, and positive-feedback digital components. However, most importantly, we present and discuss three specific applications illustrating the power of fluidics in microfluidics and MEMS. These are: a gas-analyzer-on-a-chip, capable of simultaneous analysis of multiple gas mixtures with clinical accuracies; an intermittent oxygen delivery system that provides supplemental oxygen to ambulatory patients through a nasal cannula; and, an array of vortex microvalves capable of controlling propellants for micropropulsion systems or for the temporal and spatial modulation of fuel for the optimal control of gas turbine combustors. A sampling of other fluidic in microfluidic application are mentioned to include pressure and acoustic amplification (a kosher public address system is referenced), active noise cancellation for aircraft engines and passenger compartments, opticalpneumatic transduction in optical fiber missile controls and natural gas processing, angular rate sensing, and microcytometry for cellular processing.Fluidics may be the enabling technology for many as yet undeveloped applications, particularly when recent advances micro-fabrication are taken advantage of.

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An optofluidic control system for tactical missiles and guided munitions

Cited by 2 publications

References 0 publications

Vegetation change in an urban grassy woodland 1974 - 2000

Vegetation change in an urban grassy woodland 1974 - 2000

Fluidic technology: adding control, computation, and sensing capability to microfluidics

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