Abstract: A non-contact flood and moisture detector for detecting water on remote surface includes a source of IR radiation directed towards the remote surface and projecting a field of illumination on the remote surface, and a receiver of IR radiation directed towards the remote surface, and collecting the IR radiation from a field of view on the remote surface, with the field of illumination and the field of view at least partially overlapping. A portion of the IR radiation is backscattered and received by the receiver and a portion of the IR radiation is specularly reflected and not received by the receiver. An electronic circuit synchronized with the source and the receiver compares the IR radiation measured by the receiver to a dry baseline condition level where a decrease in the backscattered IR radiation measured by the receiver indicates the presence of water.

Abstract: The present invention is a de-icing system that uses electro-magnetic actuators mounted within the airfoil of an aircraft to effect de-icing. Advantageously, the actuators have low-energy requirements. Each actuator includes conductive strips fabricated on a flexible dielectric sheet. The conductive strips are wound into coils with the actuators shaped into a flattened elongated tube. The axis of the winding coils is coincident with the longitudinal axis of the elongated tube. Low adhesive coatings may be used to enhance the efficiency of the electro-magnetic coils in expulsing the ice accretion.

Abstract: The present invention is an improved ice sensor which is particularly effective in measuring and quantifying non-uniform, heterogeneous ice typically found on aircraft leading edges and top wing surfaces. In one embodiment, the ice sensor comprises a plurality of surface mounted capacitive sensors, each having a different electrode spacing. These sensors measure ice thickness by measuring the changes in capacitance of the flush electrode elements due to the presence of ice or water. Electronic guarding techniques are employed to minimize baseline and parasitic capacitances so as to decrease the noise level and thus increase the signal to noise ratio. Importantly, the use of guard electrodes for selective capacitive sensors also enables distributed capacitive measurements to be made over large or complex areas, independent of temperature or location, due to the capability of manipulating the electric field lines associated with the capacitive sensors.

Abstract: The present invention is de-icing system that uses electromagnetic actuators mounted within the airfoil of an aircraft to effect de-icing. Advantageously, the actuators have low voltage and current requirements. Each actuator includes conductive strips fabricated on a flexible dielectric sheet. The conductive strips are wound into coils with the actuator shaped into a flattened elongated tube. The axis of the winding coils is coincident with the longitudinal axis of the elongated tube.

Abstract: A new deicing technology is described which utilizes the actuating properties of shape memory alloys (SMAs) to debond ice accretion formed on a surface. A thin sheet of SMA material is mounted to the icing prone surface to perform the force and displacement combination that can debond the ice. The SMA sheet is activated to expand or contract causing shearing and peeling of the ice. An SMA actuator portion located aft of the icing area can be used to pull the sheet over a ribbed underlay and grooved bands which generates a strain field that severs the ice's adhesive bond. Two-way shape memory action and natural ice latent heat powering are used in different modes of operation to reduce the power requirements and the structural complexity of the deicing system.

Abstract: The present invention is an improved ice sensor which is particularly effective in measuring and quantifying non-uniform, heterogeneous ice typically found on aircraft leading edges and top wing surfaces. In one embodiment, the ice sensor comprises a plurality of surface mounted capacitive sensors, each having a different electrode spacing. These sensors measure ice thickness by measuring the changes in capacitance of the flush electrode elements due to the presence of ice or water. Electronic guarding techniques are employed to minimize baseline and parasitic capacitances so as to decrease the noise level and thus increase the signal to noise ratio. Importantly, the use of guard electrodes for selective capacitive sensors also enables distributed capacitive measurements to be made over large or complex areas, independent of temperature or location, due to the capability of manipulating the electric field lines associated with the capacitive sensors.

Abstract: The de-icing system of the present invention comprises a piezoelectric sensor means and a processor means. A piezoelectric film is the preferred sensor means and a microprocessor is the preferred processor means. In a preferred embodiment, a strip of piezoelectric film placed at a point of model kinetic energy such as the boundary layer transition point or the vortex generator of the aircraft. Such placement of the strip provides adequate airflow to excite the piezoelectric film without using a power source, thus providing a passive system. The sensor allows measurement of distributedSTATEMENT REGARDING FEDERALLY SPONSORED RESEARCHThis invention was made with Government support under Contract No. DAAH01-87-C-0860 awarded by the Defense Advanced Research Agency (DoD), Defense Small Business Innovation Research Program. The Government has certain rights in this invention.

Abstract: A system is disclosed for monitoring a structure and detecting disturbances and faults associated with such structure. The system includes an actuation device for mechanically exciting the structure, a sensing device for transducing vibrations experienced by the structure, and digital signal processing means for processing signals output by the sensing device. The response of the structure due to the mechanical excitation is analyzed and a baseline or normal response is determined. Vibrations of the structure are then analyzed and compared to the normal response of the structure and the nature of disturbances identified. Another aspect of the invention relates to a system for monitoring cracks, strains and the like and includes a continuity/strain sensor having a piezoelectric layer, and first and second low resistance layers. By suitably monitoring sensors in accordance with the invention, the magnitude as well as the location of a force can be determined.

Abstract: The change in capacitance of a sensor is linearly proportional to ice thickness provided that the ice thickness is significantly less than the distance between the conductive electrodes. By employing sensors with different electrodes, the sensitivity to ice may be traded off against the ability to measure greater ice thickness. A sensor with small spacing between electrodes will exhibit a large change in capacitance when covered by a thin layer of ice, however, the capacitance change will be linear only for very thin layers of ice. A sensor with greater spacing between electrodes is less sensitive to ice accretion but has a correspondingly greater ice thickness measurement range. Accordingly, sensor (55) is relatively sensitive and is employed to determine whether or not ice or water is present.

Abstract: A method and apparatus are disclosed for detecting the nature of fluid flow. Specifically, an omnidirectional aerodynamic sensor is disclosed comprising an omnidirectional aerodynamic drag force inducing probe, a force transducer and a signal processor. The force transducer is illustratively an array of strain gauges which detect forces in each of three orthogonal directions. Such forces are initially detected by the probe and then transmitted to the transducer. The transducer outputs electrical signals which the signal processor processes in order to determine, for example, aircraft angle-of-attack and angle-of-sideslip as well as wind speed and direction. The invention is especially useful in the field of aviation.