Autonomous Airborne Multi-Rotor UAS Delivery System

Within current combat environments, there is a demand for rapid and extremely precise re-supply missions. Typical combat airdrops require long periods of planning and can produce a large signature in an operating environment which relies on stealth for various mission sets. Team Hermes, made up of four members from the West Point graduating class of 2019, offers a new re-supply method to answer this demand. The design will allow for the delivery of a quadcopter carrying 1.5 pounds of cargo within a 5-meter radius of an impact point on the ground

Spin Stabilization of an Air Ambulance Litter

This paper proposes a new approach to stabilize the spin of a suspended litter during air ambulance rescue hoist operations. Complex forces generated by the helicopter’s downwash may cause a patient suspended in a rescue litter to spin violently. In severe cases, the spin destabilizes the suspended load, risks injury to the patient, and jeopardizes the safety of the aircrew. The presented design employs an anti-torque device to arrest the spin that is safer and faster than a tagline and is without the tactical constraints of the tagline. The device follows tailored control laws to accelerate a flywheel attached to the litter, thereby generating sufficient angular momentum to counteract the spin and stabilize the suspended litter. An inertial measurement unit (IMU) measures the position, angular velocity, and angular acceleration of the litter and delivers this information to a microcontroller. The research and prototype design were developed under the support of the U.S. Army 160th Special Operations Aviation Regiment (SOAR)

Very rapid long-distance sea crossing by a migratory bird

Landbirds undertaking within-continent migrations have the possibility to stop en route, but most long-distance migrants must also undertake large non-stop sea crossings, the length of which can vary greatly. For shorebirds migrating from Iceland to West Africa, the shortest route would involve one of the longest continuous sea crossings while alternative, mostly overland, routes are available. Using geolocators to track the migration of Icelandic whimbrels (Numenius phaeopus), we show that they can complete a round-trip of 11,000 km making two non-stop sea crossings and flying at speeds of up to 24 m s-1; the fastest recorded for shorebirds flying over the ocean. Although wind support could reduce flight energetic costs, whimbrels faced headwinds up to twice their ground speed, indicating that unfavourable and potentially fatal weather conditions are not uncommon. Such apparently high risk migrations might be more common than previously thought, with potential fitness gains outweighing the costs

Dataset supporting the paper: Truth table invariant cylindrical algebraic decomposition

The files in this data set support the following paper: ########################################################################################## Truth table invariant cylindrical algebraic decomposition. Russel Bradford, James H. Davenport, Matthew England, Scott McCallum and David Wilson. http://opus.bath.ac.uk/38146/ ########################################################################################## Please find included the following: ############################## 1a) A Maple worksheet: Section1to7-Maple.mw 1b) A pdf printout of the worksheet: Section1to7-Maple.pdf 1c) A Maple Library file: ProjectionCAD.mpl These files concern the Maple results for the worked examples throughout Sections 1-7 of the paper. To run the Maple worksheet you will need a copy of the commercial computer algebra software Maple. This is currently available from: http://www.maplesoft.com/products/maple/ The examples were run in Maple 16 (released Spring 2012). It is likely that the same results would be obtained in Maple 17, 18, 2015 and future versions, but this cannot be guaranteed. An additional code package, developed at the University of Bath, is required. To use it we need to read the Maple Library file within Maple as follows: >>> read("ProjectionCAD.mpl"): >>> with(ProjectionCAD): More details on this Maple package are available in the technical report at http://opus.bath.ac.uk/43911/ and in the following publication: M. England, D. Wilson, R. Bradford and J.H. Davenport. Using the Regular Chains Library to build cylindrical algebraic decompositions by projecting and lifting. Proc ICMS 2014 (LNCS 8593). DOI: 10.1007/978-3-662-44199-2_69 If you do not have a copy of Maple you can still read the pdf printout of the worksheet. ############################## 2) A zipped directory WorkedExamples-Qepcad.zip This directory also concerns the worked examples from Sections 1-7 of the paper, this time when studied with Qepcad-B. Qepcad-B is a free piece of software for Linux which can be obtained from: http://www.usna.edu/CS/qepcadweb/B/QEPCAD.html All the files in the zipped directory end in either "-in.txt" or "-out.txt". The former give input for Qepcad and the latter record output. Hence readers without access to Qepcad (e.g. on a Windows system) can still observe the output in the latter files. To verify the output readers should use the following bash command to run a Qepcad input file "Ex-in.txt" and record the output in "Ex-out.txt". >>> qepcad +N500000000 +L200000 Ex-out.txt Windows users without Linux access can still read the existing output files in the folder. ############################## 3a) The text file: Section82-ExampleSet.txt 3b) A Maple worksheet: Section82-ExampleSet.mw 3b) A pdf printout of the worksheet: Section82-ExampleSet.pdf The textfile defines the example set which is the subject of the experiments in Section 8.2, whose results were summarised in Table 2. Within the file the 29 examples are defined in the following syntax: (a) First a line starting with "#" giving the full example name followed in brackets by the shortened name used in Table 2. (b) Then a second line in which the example is defined as a list of two sublists: i) The first sublist defines the polynomials used. They are sorted into further lists, one for each formulae in the example. Each of these has two entries: --- The first is either a polynomial defining an equational constraint (EC); a list of polynomials defining multiple ECs; or an empty list (signalling no ECs). --- The second is a list of any non ECs. ii) The second sublist is the variable ordering from highest (eliminate first in projection) to lowest. Note that Maple algorithms use this order by Qepcad the reverse. This is the syntax used by the TTICAD algorithm that is the subject of the paper. The text file doubles as a Maple function definition. When read into Maple the command GenerateInput is defined which can provide the input in formats suitable for the three Maple algorithms tested. An example is given in the Maple worksheet / pdf. We note that the timings reported in the paper were from running Maple in command line mode. See also the notes for files (1) above. The same example set was tested in Qepcad. Here explicit ECs for a parent formula were entered in dynamically as products of the individual sub-formulae ECs, in cases where an explicit EC exists. See also Qepcad notes for file (2) above. Finally, the example set was also tested in Mathematica. Mathematica's CAD command does not return cell counts - these were obtained upon request to a Mathematica developer. Hence they are not recreatable using the information here (something outside the control of the present authors). ############################## 4a) A Maple worksheet: Section83-Maple.mw 4b) A pdf printout of the worksheet: Section83-Maple.pdf This shows how the numbers in Table 3 from Maple were obtained. See also notes for files (1) above. ############################## 5a) A zipped directory Section83-Qepcad.zipped This shows how the numbers in Table 3 from Qepcad were obtained. See also notes for file (2) above.Cell counts and timings of various CAD algorithms

Applying Lean Six Sigma: Personnel Reliability Program

The Personnel Reliability Program (PRP) monitors over 400 employees who handle controlled chemical or biological agents for the U.S. Army Combat Capabilities Development Command Chemical Biological Center (CCDC-CBC). The program requires an annual recertification consisting of a medical evaluation, safety training requirements, both in-person and online, and security clearance updates. The annual recertification process begins when a program administrator notifies a PRP enrolled employee to complete their recertification. The process is complete when administrators document the employee’s completion of all recertification requirements. Initial surveys revealed over 20% of employees were dissatisfied with the annual recertification process and over 30% of employees were dissatisfied with the instructions provided to complete the recertification requirements. A Lean Six Sigma study was performed to improve the recertification process and increase employee satisfaction. A secondary goal for the study was to decrease the average cost, per employee, of completing the annual recertification process

Initial Testing and Constitutive Modeling of Cellular Rubber Subjected to Large Strains and High Strain Rates

In order to allow for the numerical modeling of impacts for the design of live fire facilities commonly used by military and law enforcement personnel against next generation and environmentally friendly ammunition currently in development, constitutive models for novel target materials must be developed. Many existing facilities are constructed from AR500 steel, coupled with a layer of cellular rubber to reduce impact velocities and contain projectile fragments. High strain rate models, such as the commonly used Johnson-Cook constitutive model, are widely available to characterize AR500 steel, but calibrated models do not currently exist to characterize the cellular rubber. This project seeks to address this shortfall and provide a suitable material model for designers of these facilities in order to ensure the safety of users and the public. Appropriate constitutive models that account for the large strain, high strain rates, and temperature effects experienced during ballistic events and the porosity of the material were researched and a plan developed for future materials testing. Three suitable models were selected for further analysis — A Non-Linear Elastic Model described by Johnson in his work with polyurethane coupled with a Mie-Gruneisen equation of state to account for the porosity of the material, an Osborn-Hull model developed for use with crushable solids, and the Holmquist-Johnson-Cook Model commonly used for cementitious materials

Autonomous Teammates for Squad Tactics

The United States Department of Defense seeks to integrate small unmanned aircraft systems (UAS) into infantry squads and develop tactics, techniques, and procedures using unmanned systems. Through an iterative design process consisting of live-fly tactical exercises, this research investigates the teaming of humans with unmanned aerial systems. Exercises involve force on force engagements to encourage the development of tactics and procedures for the future operating environment. Three successful mission tactics for leveraging UAS in missions are defined. In addition to autonomy, teams leverage convolutional and artificial deep neural networks running real time on aerial video feeds to identify and classify combatants and friendly forces