Abstract: One embodiment is an apparatus including an inner reference tube associated with a load-bearing rotating shaft and having a first set of teeth associated therewith and disposed around a periphery thereof; an outer reference tube associated with an input gear and disposed about the inner reference, the outer reference tube and having a second set of teeth associated therewith and disposed around a periphery thereof wherein teeth comprising the second set of teeth are interleaved with teeth comprising the first set of teeth to comprise an interleaved set of teeth and wherein the inner reference tube and the outer reference tube rotate about a same longitudinal axis and at a same speed as the rotating shaft; and a sensor system comprising a first variable resistance sensor (“VRS”) configured to detect a presence of successive teeth of the interleaved set of teeth and generate an output signal indicative thereof.

Abstract: A method and system to measure a parameter associated with a component, device, or system with a specified accuracy, including: providing one or more sensors operably disposed to detect the parameter; obtaining a coarse measurement of the parameter within a first range using the one or more sensors, wherein the first range includes minimum and maximum values for the parameter; obtaining a fine measurement of the parameter within a second range using the one or more sensors, wherein the second range is smaller than the first range and has a specified ratio to the first range that provides the specified accuracy; determining a current value of the parameter by combining the coarse and fine measurements; and providing the current value of the parameter to a communications interface, a storage device, a display, a control panel, a processor, a programmable logic controller, or an external device.

Abstract: Systems and methods include providing an aircraft with a direct drive dual-concentric valve (D3V) having a body, an outer secondary spool coaxially located within a bore of the body and linearly displaceable relative to the body, an inner primary spool coaxially located within a bore of the secondary spool and linearly displaceable relative to the secondary spool and the body, and multiple motor assemblies coupled to the primary spool that provide selective displacement of the primary spool or the secondary spool. Each motor assembly includes a clutching mechanism that selectively couples a motor of the motor assembly to and from the primary spool.

Abstract: A system and method for preventing a maximum asymmetric condition between pylon tilt angles due to a degraded pylon in a fly-by-wire tiltrotor aircraft during transitions between airplane mode and helicopter mode includes a conversion system for imparting movement on a right and left pylon. A flight control computer is operatively connected to a set of transducers for measuring pylon angles. The flight control computer is further connected to a set of actuators which are attached to each pylon. The flight control computer receives flight dynamics input from the set of transducers and/or the pilot and sends pylon command to the set of actuators. The conversion system measures the difference between the pylon angles during the transition and provides a pylon command adjustment if the difference exceeds a preset threshold.