Abstract: A pressure control valve having a common plenum formed by two flow control valves that each utilize electrically controlled piezoelectric actuators to generate a number of possible operating states and thus control an output pressure from the common plenum formed by the two flow control valves. The flow control valves each have at least one pressure fitting and nozzle, and a nozzle orifice sealing mechanism coupled to the piezoelectric actuator. The piezoelectric actuator may be a piezo-ceramic actuator fixed along one side to a chamber of the flow control valve and having a free side opposite the fixed side. Upon receiving a voltage of a desired magnitude and polarity, the free side of the piezo-ceramic actuator and the nozzle orifice sealing mechanism moves to control a fluid flow into the common plenum. By controllably dithering the piezoelectric actuators, the output pressure from the common plenum may be accurately regulated.

Abstract: A tandem suspension for connecting a vehicle chassis to front and rear steerable axles is provided. The tandem suspension includes, on each side of the vehicle, a front leaf spring linking the chassis and the front axle, a rear leaf spring linking the chassis and the rear axle, an equalizer assembly mounted to the chassis for equalizing the front and rear axles, a front air spring disposed between the chassis and the front axle, a rear air spring disposed between the chassis and the rear axle, and a pneumatic control system pneumatically linked to the front and rear air springs for supplying pressurised gas thereto and operable to unload one of the front and rear air springs. A method of installing a tandem suspension in a vehicle having a first steerable axle and a front leaf spring is also provided.

Abstract: A range measurement device is disclosed. The device comprises a flash laser radar configured to produce a first laser pulse at a first time. The device receives, at a second time, reflections of the first laser pulse from at least one object within a 360 degree field of view. The device further comprises a timing electronics module, an image sensor in communication with the timing electronics module, a mirror element coupled between the image sensor and the laser radar, and a lens. The mirror element includes a first reflector configured to disperse the reflections of the first laser pulse within at least a portion of the 360 degree field of view and a second reflector configured to collect returning reflections of the first laser pulse from the at least one object into the image sensor. The lens is configured to focus the returning reflections onto the image sensor.

Abstract: Systems and methods for acquiring global navigation satellite system (GNSS) signals. An incoming signal is multiplied with a time shifted spreading code replica and converted to zero (or very low) nominal frequency. The converted signal is filtered and downsampled by a large scale. A signal power metric and frequency offset are then determined. This is performed over multiple slices. Fast acquisition is achieved by parallel concatenation of numerous slices.

Abstract: Systems and methods for MEMS device fabrication. A layer of photoresist is formed on a substrate. A first region of the substrate is exposed to a radiation source through a photomask. The first region of exposed photoresist is developed with a developer solution in order to etch the exposed regions to a first depth. A second region is exposed to radiation through a second photomask. The second photomask defines areas in which a bump feature is intended on the substrate. The second region is developed with the developer solution, preparing the first and second exposed regions for a layer of metal. A layer of metal is deposited on the substrate, such that the metal attaches to both the substrate and any remaining photoresist on the substrate. The remaining photoresist and its attached metal is dissolved away leaving an interconnect pattern and at least one bump feature.

Abstract: The present invention provides a distributed antenna communications system and methods of implementing a distributed antenna communications system. In accordance with an embodiment of the invention, a distributed antenna system comprises: a base station configured for communication with a telecommunications network; a multi-port repeater hub connected to the base station to receive a communications signal from the base station and to distribute the communications signal to a plurality of ports of the multi-port repeater hub, the multi-port repeater hub comprising a scanner for scanning a plurality of frequency channels to identify one or more channels of the communications signal received from the base station; and a plurality of antenna units, each coupled to one of the ports of the multi-port repeater hub.

Abstract: Systems and methods for improving output resolution of an optical drive circuit in an optical sensor. The optical sensor circuit includes an optics circuit that generates analog measurement data, a detector circuit that detects the analog measurement data and converts the analog measurement data to a digital measurement data, and a signal processing circuit that demodulates the digital measurement data and generates a segmented digital signal based on the demodulated digital measurement data. The optical sensor circuit further includes an optics drive circuit that generates an analog drive signal based on the segmented digital signal. The analog drive signal is then used to drive the optical circuit.

Abstract: A reconfigurable mounting bracket is disclosed. The bracket includes a first face plate configured to attach to an enclosure, a first flange that extends perpendicularly from a first end of the first face plate, and a second flange that extends perpendicularly from a second end of the first face plate, the second flange extending in an opposing direction from the first flange. The reconfigurable mounting bracket accommodates a plurality of attachment options.

Abstract: A system and method for enhancing the performance of wideband digital RF transport systems is disclosed, which enables the transport of different bandwidth segments on a plurality of wideband channels by selecting an optimal clock sample rate for each bandwidth segment to be transported. Thus, the bandwidth segments are proportionally allocated so that an optimum amount of bandwidth can be transported at the serial bit rate.

Abstract: The present invention comprises systems for and methods of providing dedicated capacity in a wireless cellular network. In an embodiment, a system for providing dedicated capacity in a cellular network comprises: a first base station positioned at a first location and being communicatively coupled to a telephone network, the first base station having an outdoor cellular antenna for forming a local coverage area, a second base station positioned at the first location and being communicatively coupled to the telephone network; and an indoor cellular antenna for forming a coverage area at a second location. The second location is geographically remote from the first location and the indoor cellular antenna is communicatively coupled to the second base station such that mobile communications equipment located within the coverage area at the second location are communicatively coupled to the telephone network via the indoor cellular antenna and the second base station.

Abstract: Systems and methods for compensating for nonlinear phase shift accumulation in an optical ring resonator. An example method includes sending a first beam in a clockwise direction around the optical ring resonator and sending a second beam in a counterclockwise direction around the optical ring resonator. Then, nonlinear phase shift accumulation of the first and second beams is compensated for within the optical ring resonator. Compensating includes creating a negative Kerr effect phase shift for each beam based on an estimate of accumulated positive Kerr effect.

Abstract: A relative navigation system including a first unit responsive to the motion of a first position, a second unit responsive to the motion of a second position and a processing unit that generates a relative navigation solution as a function of first unit information and second unit information. The generated relative navigation solution is indicative of at least one of: a relative position vector of the second position relative to the first position, a relative velocity of the second position relative to the first position, and a relative attitude of the first unit at the first position relative to the second unit at the second position.

Abstract: An air data system and method for a ducted fan air-vehicle is described. The air data system includes a plurality of air pressure sensors placed around a lip of an air duct of the ducted fan air-vehicle. The air data system calculates the speed and direction of airflow surrounding the ducted fan air-vehicle based on pressure data measured across the lip of the air duct. Additionally, the air data system may estimate forces generated by airflow surrounding the air-vehicle.

Abstract: A system to prevent unauthorized access to a protected device includes a test access port operable to mate with a test access connector, a security key port operable to mate with a security key and a security device in electrical communication with the test access port and the security key port. The protected device is in electrical communication with the test access port when the security device is enabled based on the security key. The test equipment is authorized for access to the protected device when the security device is enabled.

Abstract: A gimballed valve for a flow control valve operates as a sealing member for an adjustable nozzle and is coupled to a piezoelectric actuator having stacked piezoelectric members that are toroidally shaped. The gimballed valve includes at least two support rings and a center closure member. In one embodiment only an outermost support is in contact with at least one member of the piezoelectric actuator. The support rings may be concentrically arranged and coupled together with flexure members. The center closure member operates to seal against an orifice in the adjustable nozzle and may deflect upon contact with the adjustable nozzle to account for misalignment issues that may arise during machining and/or assembly of the flow control valve.

Abstract: An apparatus including a conductive sleeve including an outer-conductive surface and an inner passageway that extends from a first end at least partially to a second end. The passageway is adapted to receive and shield a device that provides at least one of a radio frequency path and an electrical current path. In one embodiment, movable flanges at an end of the sleeve are used for coupling the outer-conductive surface of the sleeve to a ground connection. In one embodiment, the sleeve may further be used to interconnect a pair of RF structures with ground connections at each end of the sleeve and with signal connections to the device at each end.

Abstract: A power supply having a flyback topology includes a flyback transformer and a current sense circuit that outputs a current signal indicative of a current output by the power supply. The current sense circuit includes a current sense transformer coupled to the flyback transformer.

Abstract: A method and system are provided for autonomous vehicle navigation. In the method and system, one or more Global Positioning System (GPS) sensors, one or more inertial sensors, and one or more image sensors are provided on an autonomous vehicle. During operation of the autonomous vehicle, one or more GPS measurements, one or more inertial measurements, and one or more image measurements are obtained from the respective GPS sensors, inertial sensors, and image sensors. Each of the GPS measurements, inertial measurements, and image measurements are integrated together to estimate a position of the autonomous vehicle over time.

Abstract: A method and system for adapting fault tolerant computing. The method includes the steps of measuring an environmental condition representative of an environment. An on-board processing system's sensitivity to the measured environmental condition is measured. It is determined whether to reconfigure a fault tolerance of the on-board processing system based in part on the measured environmental condition. The fault tolerance of the on-board processing system may be reconfigured based in part on the measured environmental condition.

Abstract: A method of determining an operational state of a navigation system of a platform is provided. The method comprises testing at least a portion of hardware in the navigation system. Additionally, a measurement of at least one navigation variable from an inertial sensor is combined with a measurement of another navigation variable. A plurality of residuals for the measurement of at least one navigation variable and the measurement of another navigation variable are determined with a blending filter. An error for the measurement of at least one navigation variable is estimated based on the plurality of residuals. The method also predicts an error for the measurement of at least one navigation variable while the navigation system is in route.