Abstract: Devices and methods are disclosed for determining position and controlling navigation by sensing movement through the Earth's magnetic field. Change in position is determined by integrating velocity which has been normalized for spatial and temporal field variation. Position is registered with respect to starting point and/or subsequently detected environmental feature. Signals are provided to actuator for guidance, navigation and control.

Abstract: Devices and methods are disclosed for determining position and controlling navigation by sensing movement through the Earth's magnetic field. Change in position is determined by integrating velocity which has been normalized for spatial and temporal field variation. Position is registered with respect to starting point and/or subsequently detected environmental feature. Signals are provided to actuator for guidance, navigation and control.

Abstract: A system for sound cancellation includes a source microphone for detecting sound and a speaker for broadcasting a canceling sound with respect to a cancellation location. A computational module is in communication with the source microphone and the speaker. The computational module is configured to receive a signal from the source microphone, identify a cancellation signal using a predetermined adaptive filtering function responsive to acoustics of the cancellation location, and transmit a cancellation signal to the speaker.

Abstract: Methods for generating a directional sound environment include providing a headgear unit having a plurality of microphones thereon. A sound signal is detected from the plurality of microphones. A transfer function is applied to the sound signal to provide a transformed sound signal, and the transformed sound signal provides an approximation of free field hearing sound at a subject's ear inside the headgear unit.

Abstract: A system for sound cancellation includes a source microphone for detecting sound and a speaker for broadcasting a canceling sound with respect to a cancellation location. A computational module is in communication with the source microphone and the speaker. The computational module is configured to receive a signal from the source microphone, identify a cancellation signal using a predetermined adaptive filtering function responsive to acoustics of the cancellation location, and transmit a cancellation signal to the speaker.

Abstract: A method and device for processing quasi-periodic signals from machines that provides improved diagnostic results. A dynamic, non-uniform signal termed the speed clock controls processing of the signals. This processing prevents the leakage artifacts and poor frequency resolution that can mask signal components and limit the diagnostic value of existing technology. Valuable phase information, which is destroyed by existing sampling methods controlled directly by encoder signals, is retained. The invention also enables removal of large masking signal components without otherwise altering the signal. By preventing artifacts, retaining phase information, and removing undesirable signal components, the present invention is a dramatic improvement over existing technology for processing signals to determine the health and performance of operating machines.

Abstract: A method and device for processing encoder signals from turbomachines to produce frequency modulation signals representing fully isolated rotor vibrational resonances. Multi-sensor and multi-sideband group processing provides enhanced results. The method provides dramatically improved frequency resolution. Amplitude modulation and random noise effects are removed by a variety of artifact-free techniques. Signals then are completely separated into components for rotational vibration and translational vibration. Fully isolating rotational vibration unmasks previously undetectable signal components of diagnostic value. In cases of high background vibration, Wiener filtering removes the effects of exogenous vibration. By these various techniques, the present invention provides significantly enhanced diagnostic information regarding condition and performance in turbomachines.

Abstract: The present invention provides a method and system for analyzing signals from rotating machines containing rotating components that slip and, thereby, to detect faults in those components. The signals are processed by a series of steps to generate coherently averaged spectra and derived features that indicate defects in, or certain other features of, machine components that slip or rotate asynchronously.

Abstract: A gear defect analyzing system records the interaction of each tooth of a gear system until the interaction begins to repeat and then processes the information in such a way as to identify defective gear tooth. Signals from a gear box are detected by an accelerometer and a shaft encoder and fed to an interface circuit and then to an analog signal preprocessing circuit. The preprocessing circuit conditions the signal so that it can be analyzed by a microcomputer. The system has the capability of identifying the class of incoming signals, determining the optimal time domain average, eliminating unwanted spectral components and interference, computing specific measurements relating to gear wear and then performing analysis of time history within a given system operating state to determine which gears and gear teeth are defective. By recording each tooth-to-tooth interaction over a period of time, and then processing the recorded matrix of data, it is possible to locate individual tooth defects.

Abstract: The present invention provides a method and detection system for determining whether a person or other animate body is present in a vehicle by analyzing the power of the output signal from a geophone placed in contact with the vehicle structure. First an electrical signal is obtained which is a function of the vibrations emanating from the structure, and this signal is sampled on a contiguous basis over a plurality of time periods of equal duration. From these samples, a determination is then made as to whether a dense accumulation of power exists in the vicinity of the lowest power point of the sampled time periods and whether this lowest power point is above a predetermined minimum level. The system for accomplishing this method may include a seismic transducer used as a sensing device and a micro-computer for processing the output signals from the seismic transducer. The micro-computer will, on a continguous basis, sample about 22/3 seconds of data at a time.