17 research outputs found

    Aided targeting system simulation evaluation

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    Simulation research was conducted at the Crew Station Research and Development Facility on the effectiveness and ease of use of three targeting systems. A manual system required the aviator to scan a target array area with a simulated second generation forward looking infrared (FLIR) sensor, locate and categorize targets, and construct a target hand-off list. The interface between the aviator and the system was like that of an advanced scout helicopter (manual mode). Two aided systems detected and categorized targets automatically. One system used only the FLIR sensor and the second used FLIR fused with Longbow radar. The interface for both was like that of an advanced scout helicopter aided mode. Exposure time while performing the task was reduced substantially with the aided systems, with no loss of target hand-off list accuracy. The fused sensor system showed lower time to construct the target hand-off list and a slightly lower false alarm rate than the other systems. A number of issues regarding system sensitivity and criterion, and operator interface design are discussed

    Measures for simulator evaluation of a helicopter obstacle avoidance system

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    The U.S. Army Aeroflightdynamics Directorate (AFDD) has developed a high-fidelity, full-mission simulation facility for the demonstration and evaluation of advanced helicopter mission equipment. The Crew Station Research and Development Facility (CSRDF) provides the capability to conduct one- or two-crew full-mission simulations in a state-of-the-art helicopter simulator. The CSRDF provides a realistic, full field-of-regard visual environment with simulation of state-of-the-art weapons, sensors, and flight control systems. We are using the CSRDF to evaluate the ability of an obstacle avoidance system (OASYS) to support low altitude flight in cluttered terrain using night vision goggles (NVG). The OASYS uses a laser radar to locate obstacles to safe flight in the aircraft's flight path. A major concern is the detection of wires, which can be difficult to see with NVG, but other obstacles--such as trees, poles or the ground--are also a concern. The OASYS symbology is presented to the pilot on a head-up display mounted on the NVG (NVG-HUD). The NVG-HUD presents head-stabilized symbology to the pilot while allowing him to view the image intensified, out-the-window scene through the HUD. Since interference with viewing through the display is a major concern, OASYS symbology must be designed to present usable obstacle clearance information with a minimum of clutter

    Genetic Algorithm Guidance of a Constraint Programming Solver for the Multiple Traveling Salesman Problem

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    This project developed a metaheuristic approach to the Multiple Traveling Salesman Problem that pairs a custom genetic algorithm with a conventional combinatorial optimization solver. This combined approach was used to build an optimal route for two popular radio show hosts to visit each of the 37 Atlanta area Jersey Mike\u27s Subs in one day. This supported a fundraising eort to send children with chronic and terminal illnesses to Disney World through an organization called Bert\u27s Big Adventure. Atlanta-area Jersey Mike\u27s locations donated 100% of proceeds earned on this Day of Giving to Bert\u27s Big Adventure. With the suggested route developed through our approach, the radio hosts successfully visited all 37 Jersey Mike\u27s in one day, a task Bert\u27s Big Adventure staff members had not been able to complete in previous years

    Objective Situation Awareness Measurement Based on Performance Self-Evaluation

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    The research was conducted in support of the NASA Safe All-Weather Flight Operations for Rotorcraft (SAFOR) program. The purpose of the work was to investigate the utility of two measurement tools developed by the British Defense Evaluation Research Agency. These tools were a subjective workload assessment scale, the DRA Workload Scale and a situation awareness measurement tool. The situation awareness tool uses a comparison of the crew's self-evaluation of performance against actual performance in order to determine what information the crew attended to during the performance. These two measurement tools were evaluated in the context of a test of innovative approach to alerting the crew by way of a helmet mounted display. The situation assessment data are reported here. The performance self-evaluation metric of situation awareness was found to be highly effective. It was used to evaluate situation awareness on a tank reconnaissance task, a tactical navigation task, and a stylized task used to evaluated handling qualities. Using the self-evaluation metric, it was possible to evaluate situation awareness, without exact knowledge the relevant information in some cases and to identify information to which the crew attended or failed to attend in others

    An Obstacle Alerting System for Agricultural Application

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    Wire strikes are a significant cause of helicopter accidents. The aircraft most at risk are aerial applicators. The present study examines the effectiveness of a wire alert delivered by way of the lightbar, a GPS-based guidance system for aerial application. The alert lead-time needed to avoid an invisible wire is compared with that to avoid a visible wire. A flight simulator was configured to simulate an agricultural application helicopter. Two pilots flew simulated spray runs in fields with visible wires, invisible wires, and no wires. The wire alert was effective in reducing wire strikes. A lead-time of 3.5 sec was required for the alert to be effective. The lead- time required was the same whether the pilot could see the wire or not

    Fibonacci number of the tadpole graph

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    <p>In 1982, Prodinger and Tichy defined the Fibonacci number of a graph G to be the聽number of independent sets of the graph G. They did so since the Fibonacci number聽of the path graph Pn is the Fibonacci number F(n+2) and the Fibonacci number of the cycle graph Cn is the Lucas number Ln.聽The tadpole graph Tn,k is the graph created by concatenating Cn and Pk with an edge聽from any vertex of Cn to a pendant of Pk for integers n=3 and k=0. This paper establishes formulae and identities for the Fibonacci number of the tadpole graph via algebraic and combinatorial methods.</p

    Evaluation of Helmet Mounted Display Alerting Symbology

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    Proposed helicopter helmet mounted displays will be used to alert the pilot to a variety of conditions, from threats to equipment problems. The present research was performed under the NASA Safe All-weather Flight Operations Research (SAFOR) program supported by a joint Army/NASA research agreement. The purpose of the research was to examine ways to optimize the alerting effectiveness of helmet display symbology. The research used two approaches to increasing the effectiveness of alerts. One was to increase the ability of the alert to attract attention by using the entire display surface. The other was to include information about the required response in the alert itself. The investigation was conducted using the NASA Ames Research Center's six-degree-of-freedom vertical motion simulator (VMS) with a rotorcraft cockpit. Helmet display symbology was based on the AH-64's pilot night vision system (PNVS), cruise mode symbology. A standardized mission was developed, that consisted of 11 legs. The mission included four tasks, which allowed variation in the frequency of alerts. The general trend in the data points to a small benefit from both the full-screen alert and the partial information alert

    Which Chessboards have a Closed Knight鈥檚 Tour within the Rectangular Prism?

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    A closed knight鈥檚 tour of a chessboard uses legal moves of the knight to visit every square exactly once and return to its starting position. In 1991 Schwenk completely classified the m 脳 n rectangular chessboards that admit a closed knight鈥檚 tour. In honor of the upcoming twentieth anniversary of the publication of Schwenk鈥檚 paper, this article extends his result by classifying the i 脳 j 脳 k rectangular prisms that admit a closed knight鈥檚 tour
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