154,058 research outputs found

    A comparison of two commercial and the terminal configured vehicle area navigation systems

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    A comparison was made of some of the more important features of two commercially available area navigation systems and the Terminal Configured Vehicle (TCV) area navigation system. Topics discussed included system design criteria, system elements, calculation of the navigation solution, and presentation of guidance information

    Navigation System Design with Application to the Ares I Crew Launch Vehicle and Space Launch Systems

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    For a launch vehicle, the Navigation System is responsible for determining the vehicle state and providing state and state derived information for Guidance and Controls. The accuracy required of the Navigation System by the vehicle is dependent upon the vehicle, vehicle mission, and other consideration, such as impact foot print. NASAs Ares I launch vehicle and SLS are examples of launch vehicles with are/where to employ inertial navigation systems. For an inertial navigation system, the navigation system accuracy is defined by the inertial instrument errors to a degree determined by the method of estimating the initial navigation state. Utilization of GPS aiding greatly reduces the accuracy required in inertial hardware to meet the same accuracy at orbit insertion. For a launch vehicle with lunar bound payload, the navigation accuracy can have large implications on propellant required to correct for state errors during trans-lunar injection

    Automatic Occupancy Sensing And Navigation Through Hov Lanes

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    A system and method for in-car navigation systems that could recommend using high occupancy vehicle (HOV) or carpool lanes when there is a passenger in the vehicle is disclosed. Accordingly, the vehicle control system may share the vehicle occupancy information with the navigation system that may recommend using the HOV lane when the vehicle occupancy is more than one. The system may include one or more sensors that detect the number of occupants in the vehicle and provide inputs to the vehicle control system architecture. The vehicle control system shares occupancy status with the in-car navigation system. The in-car navigation system may choose between a HOV lane and regular passing lane for better traffic flow and may recommend using the HOV lane when the vehicle occupancy is more than one. The advantages of the system include more efficient commuting without lane violation. The system may also be used in automated driving cars

    Autonomous navigation system

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    An inertial navigation system utilizing a servo-controlled two degree of freedom pendulum to obtain specific force components in the locally level coordinate system is described. The pendulum includes a leveling gyroscope and an azimuth gyroscope supported on a two gimbal system. The specific force components in the locally level coordinate system are converted to components in the geographical coordinate system by means of a single Euler transformation. The standard navigation equations are solved to determine longitudinal and lateral velocities. Finally, vehicle position is determined by a further integration

    Applicability of relative GPS to automated rendezvous between the space shuttle and space station

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    The purpose of this study is to determine the adequacy of the Global Positioning System (GPS) in providing relative navigation for automated rendezvous and proximity operations. The study was performed using the Proximity Operations Simulator (POS), Lockheed's high-fidelity, 6 degree of freedom simulation of the space shuttle and space station. This simulation includes identical models of GPS receivers for each vehicle. The navigation software in each vehicle includes identical Kalman filters. Each filter computes the absolute state of its vehicle, and the relative state vector is obtained by simply subtracting absolute states

    Applicability of relative GPS to automated rendezvous between the space shuttle and Space Station

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    The purpose of this study is to determine the adequacy of the Global Positioning System (GPS) in providing relative navigation for automated rendezvous and proximity operations. The study was performed using the Proximity Operations Simulator (POS), Lockheed's high-fidelity, six-degree-of-freedom simulation of the Space Shuttle and Space Station. This simulation includes identical models of GPS receivers for each vehicle. The navigation software in each vehicle includes identical Kalman filters. Each vehicle estimates its own state, and the relative state is obtained by simply subtracting absolute states

    Autonomous integrated GPS/INS navigation experiment for OMV. Phase 1: Feasibility study

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    The phase 1 research focused on the experiment definition. A tightly integrated Global Positioning System/Inertial Navigation System (GPS/INS) navigation filter design was analyzed and was shown, via detailed computer simulation, to provide precise position, velocity, and attitude (alignment) data to support navigation and attitude control requirements of future NASA missions. The application of the integrated filter was also shown to provide the opportunity to calibrate inertial instrument errors which is particularly useful in reducing INS error growth during times of GPS outages. While the Orbital Maneuvering Vehicle (OMV) provides a good target platform for demonstration and for possible flight implementation to provide improved capability, a successful proof-of-concept ground demonstration can be obtained using any simulated mission scenario data, such as Space Transfer Vehicle, Shuttle-C, Space Station

    Contextually Aware Navigation System

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    A contextually aware navigation system equipped in a vehicle can be used to identify that the vehicle is deviating from a predetermined route during navigation guidance. The system determines if the deviation is intentional or unintentional based on a combination of various situational factors. Thereafter, if the system determines that the deviation is intentional, the system can suspend the navigation guidance. On the other hand, if the system determines that the deviation is unintentional the system can continue with the navigation guidance
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