Raytheon

About: Raytheon is a company organization based out in Waltham, Massachusetts, United States. It is known for research contribution in the topics: Signal & Antenna (radio). The organization has 15290 authors who have published 18973 publications receiving 300052 citations.

Staying alive: a docking station for autonomous robot recharging

Abstract: Autonomous mobile robots are constrained in their long-term functionality due to a limited on-board power supply. Typically, rechargeable batteries are utilized that may only provide a few hours of peak usage before recharging is necessary. Recharging requires a robot to be taken offline, and attached to a battery charger via human intervention. This is unacceptable in environments where long-term autonomous capabilities are necessary. We present a method to provide long-term autonomy by implementing autonomous recharging. A recharging station design is presented, consisting of a stationary docking station and a docking mechanism mounted to a Pioneer 2DX robot. The docking station and robot docking mechanism are designed to work together, providing a mechanical and electrical connection between the charging system and the robot. Algorithms are implemented to monitor the battery voltage and control the docking procedure, as well as account for any errors that may occur. Initial experiments that demonstrate the validity of the approach and design are presented.

Noise compensation for autoregressive spectral estimates

Abstract: The autoregressive spectral estimator possesses excellent resolution properties for time series which satisfy the "all-pole" assumption. When noise is added to the time series under analysis, the resolution of the spectral estimator decreases rapidly as the signal-to-noise ratio decreases. The usual approach to this problem is to model the resulting time series by the more appropriate autoregressive-moving average process and to use standard time series analysis techniques to identify the autoregressive parameters. This standard technique, however, does not result in a positive-definite autocorrelation matrix. As a result, it is shown that the resulting spectral estimator may exhibit a large increase in variance. An alternative approach, termed the noise compensation technique, is proposed. It attempts to correct the estimated reflection coefficients for the effect of white noise, assuming the noise variance is known or can be estimated. Simulation results indicate that a significant decrease in the degrading effects of noise may be realized using the noise compensation technique.

MMW electronically scanned antenna

Abstract: A millimeter wave (MMW) antenna array includes a continuous transverse stub (CTS) radiating aperture comprising a set of spaced continuous transverse stubs, each having a longitudinal extent. A series feed system is coupled to an excitation source for exciting the stubs with MMW electromagnetic energy having a linear phase progression along the longitudinal extent of the stubs to produce an array beam which can be scanned over a beam scan range by changing the excitation frequency.

Method and apparatus for manufacturing composite structures

Abstract: Composite structures having a single continuous skin may be formed using automated fiber placement methods. These composite structures include frameless aircraft fuselage components offering an increased interior cabin width over conventional fuselage components. The composite structures may be constructed of multiple layers of fibers and other materials placed on a fiber placement tool that includes a mandrel body surrounded by a bladder or an integral bladder/caul sheet having expansion spaces created within the caul sheet section. Uncured composite structures may be created by placing fibers around the fiber placement tool in a plurality of discontinuous segments that are capable of moving or sliding in relation to each other so that the uncured composite structure is expandable from within. Fluid openings may be provided in the outer surface of the mandrel body for the application of vacuum and/or fluid pressure to secure the bladder to the mandrel body and to assist in the removal of the bladder from the mandrel body, respectively. Uncured composite structures may be sealed between the bladder and is clam shell molds. The uncured structures may be expanded against the inner surface of the molds by creating a vacuum between the bladder and molds.