Abstract: Systems and methods for measuring displacement parameters of rotating shafts and couplings are disclosed. In some aspects, a measurement system includes a shaft extended in a longitudinal direction and a target wheel configured to rotate with the shaft. The target wheel includes sensor targets circumferentially distributed around the target wheel. Some of the targets are slanted in the longitudinal direction and some of the targets are parallel to the longitudinal direction. The measurement system includes a sensor array including at least three sensors mounted radially around the shaft and configured to detect the sensor targets as the target wheel rotates with the shaft. The measurement system includes a controller configured to receive sensor signals from the sensors and determine, based on the sensor signals, at least an axial displacement measurement of the shaft in the longitudinal direction and a radial displacement measurement of the shaft.

Abstract: Rotary motion sensing systems are well-suited for integration in a bearing system of a rotary aircraft to provide information about the operational state of the rotor blades of the aircraft. In some embodiments, sensors are positioned on lateral sides of an elastomeric bearing system and output signals which may be processed to calculate one or more rotor blade operational states. The operational states include, for example, flap angle, lead-lag angle, and pitch angle. In other embodiments, sensors may be distributed along at least a portion of the length of a rotor blade to detect deflection of the rotor blade or its impact with another object. The operational state of the rotor blades may be transmitted to the pilot and/or the flight control computer of the aircraft in order for corrective action to be taken and/or may be stored within a control box for later review.

Abstract: Systems, devices, and methods for a hub-based active vibration control (AVC) design includes at least one pair of co-rotating motorized imbalanced rotors that create a controllable rotating force vector that can be controlled to cancel hub loads on a rotating hub. This control is achievable using a configuration in which each rotor has an axis of rotation that is offset from the hub axis of rotation. In this way, in a loss of operation failure mode, the system is designed such that centrifugal forces will cause the masses to spin to an orientation of low static imbalance.