Abstract: An active vibration control system (AVCS) and method for reducing motion and/or vibration of a seat frame within an aircraft includes vibration sensors, a controller, and force generators. In some embodiments, the vibration sensors and/or the force generators are attached to the seat frames. In other embodiments, the vibration sensors and/or the force generators are attached to aircraft structures, proximate to the seat frame. By monitoring the motion and/or vibration of the seat frame, the controller calculates a cancelling force to be generated by the force generators to reduce the vibration experienced by the seat frame and its occupant. Such seat frame vibration control can be implemented as a separate AVCS in an aircraft, or can be integrated in an existing AVCS that is also configured to provide vibration control in other parts thereof.

Abstract: Systems and methods for measuring a clearance between a rotating machine component and a sensor unit are disclosed. In some aspects, a system includes a sensor unit oriented to detect the rotating machine component as the rotating machine component rotates past the sensor unit, the sensor unit including at least a first sensing element and a second sensing element spaced apart from the first sensing element. The system includes a sensor processing unit in electrical communication with the sensor unit. The sensor processing unit is configured for receiving a first waveform from the first sensing element; receiving a second waveform from the second sensing element; and determining, based on a comparison between the first waveform and the second waveform, a distance between the blade tip and the sensor unit.

Abstract: A shaft assembly for a torque measurement system having a shaft that rotates is provided. The shaft assembly includes a cylinder fitted on to a shaft having flexible area, where the targets are formed after the cylinder is secured to the shaft and/or a cylinder mounting surface.

Abstract: A combined brake and motor providing tactile feedback control to a human-machine interface steering input device as part of a steer-by-wire system is provided. The brake is a tactile feedback device (TFD) brake and the motor is an electric motor coupled to the brake. The brake provides end stop control and resistive torque to the steer-by-wire system. The motor provides motion control to the steer-by-wire system, where motion control includes a return-to-center, a command following, an on-center control, an active force-feel, and/or a warning mode (e.g., similar to an aircraft stick shaker or a lane departure). The steer-by-wire system is an active system.

Abstract: A sensing system and method for detecting wear of an abradable layer on a stationary engine casing is provided. The system is capable of measuring the abradable thickness of the abradable layer by embedding abradable sensor in the abradable layer and measuring the changing electrical properties as the abradable sensor wears.

Abstract: The present disclosure provides an improved circular force generator having a housing configured to reduce vibrational forces transmitted to an aircraft structure. Additionally, the disclosed configuration provide the necessary safety redundancies required by the aviation industry. The circular force generator includes mounting point around the exterior of the CFG housing and a central mounting point thereby providing redundant mounting points.

Abstract: A method is disclosed to smooth the ride of a seat occupant by controlling the damping force of a fluid damper positioned between the seat and base. The method selects between different subprocesses to minimize the ride discomfort and to minimize peak seat accelerations and endstop jerks. The controller uses the input from the different subprocesses to create the best ride for the immediate operational conditions.

Abstract: An engine mount device includes a housing, a carrier within a cavity in the housing, and a flexure flexibly connecting the carrier to the housing, with a pin disposed in a hole in the carrier to support an engine. A method of providing isolation in the engine mount device includes transmitting a force from the pin into the carrier; mechanically isolating the carrier from the housing via the flexure; and providing, via the flexure, a higher stiffness in one or more radial directions of the hole compared to a stiffness provided in an axial direction of the hole.

Abstract: A vehicle vibration control system (VCS) includes a vehicle having at least an engine, a transmission, a frame, a steering column with a steering wheel attached, a passenger cabin, and a controller area network (CAN) bus. The vibration and noise in the cabin and in or around steering column are bothersome to passengers in the passenger cabin. Linear force generators (LFGs) are used to control the noise and vibration in or around the steering column and/or steering wheel. Circular force generators (CFGs) are used to control noise and vibration in the passenger cabin. Sensors are used to measure the noise and vibration.

Abstract: A system for controlling shaft displacement within a support structure, the system having a rotatable shaft, at least one bearing supporting the shaft, the at least one bearing having an inner race rotatable along with the shaft and an outer race circumferentially surrounding the inner race, an electromagnet assembly positioned about the shaft along a longitudinal axis thereof, and a controller that detects a radial motion of the shaft and determines a corrective force to reduce the radial motion of, or a parameter related to, the shaft, the controller commanding the electromagnet assembly to generate the corrective force to act on the shaft, the electromagnet assembly having a plurality of phases spaced circumferentially about the shaft, the controller commanding different phases of the electromagnet assembly to generate the corrective force so that a vector of the corrective force rotates about the longitudinal axis of the shaft.

Abstract: A system has a fin with an upstream end, a downstream end, a wall interface (412), a carrier interface (414) offset from the wall interface (412) in a radially inward direction, and an impact surface (418). The impact surface extends between an upstream end of the wall interface and an upstream end of the carrier interface. The impact surface (418) has a substantially flat portion configured to cause flow stagnation. The fin (306) has a side surface (416) extending between the impact surface (418), the wall interface (412), and the carrier interface. The impact surface (418) is joined to the side surface (416) by an edge profile (420) configured to cause turbulence or separation of the fluid flow from the fin.

Abstract: Systems, devices, and methods for active vibration control using circular force generators. In one aspect, a vehicle includes a vehicle frame, a cabin, an engine, and a number of vibration control devices mounted on the vehicle frame. Each vibration device includes a circular force generator comprising at least one mass and at least one motor configured to rotate the mass. The vibration control devices are configured to perform active vibration control to reduce noise and/or vibration within the cabin resulting from the engine deactivating a subset of cylinders in operation.

Abstract: Compliant mounting systems, devices, and methods for mounting a vehicle engine to a vehicle structure or base include a top mount, a lower mount, a center trunnion mount, and an aft mount which are configured to react forces transmitted by the engine to the vehicle structure. Metallic and elastomeric elements can provide vibrational and force isolation characteristics. Stops (e.g., snubbing elements) allow for a specific range of motion before internal mount structures contact each other to act as a conventional hard mount. Fluid elements and compressible gas-filled spaces/bladders may be incorporated to provide fluid damping behaviors to complement the metallic and elastomeric elements.

Abstract: A lateral isolator (200) has a tubular body with an upstream end and a downstream end. The lateral isolator (200) also includes an inner member (210) having a pivot ring (220) disposed within the tubular body. A first elastomeric package (236) is disposed between the tubular body and the inner member (210) longitudinally between the pivot ring (220) and the upstream end. A second elastomeric package (236) is disposed between the tubular body and the inner member (210) longitudinally between the pivot ring (220) and the downstream end.

Abstract: Systems and method for active vibration control on an aircraft. An active vibration control system (AVCS) is configured for an aircraft having an aircraft structure and a gun. The AVCS includes at least one control sensor on the aircraft, at least one force generator on the aircraft, and at least one controller in electronic communication with the sensor and the force generator. The controller is configured for determining, using the at least one control sensor, force generating commands for controlling vibrations acting on the aircraft structure, sending the force generating commands to the at least one force generator, causing the at least one force generator to produce a vibration canceling force, determining that the gun is firing, and in response to determining that the gun is firing, determining different force generating commands and sending the different force generating commands to the at least one force generator.

Abstract: Systems and methods for measuring torque on a drive train component of a rotating drive system are disclosed. In some aspects, a system includes a target assembly, a sensor assembly, and a sensor processing unit. The sensor assembly is located proximate to the target assembly, and the sensor assembly includes sensors mounted radially around the shaft and configured to detect sensor targets as the target assembly rotates with the drive train component. The sensor processing unit is configured for receiving sensor signals from the sensor assembly and outputting a torque signal based on the sensor signals. The sensor processing unit is configured for receiving target calibration data for the target assembly and sensor calibration data for the sensor assembly. The sensor processing unit is configured for verifying that the target calibration data corresponds to the target assembly and that the sensor calibration data corresponds to the sensor assembly.

Abstract: Circular force generator devices (100), systems, and methods for damping vibrations which include two complementary rotor assemblies (110, 120) that are rotatable together about a common shaft (102) but that have an adjustable rotational position (P1, P2) with respect to one another such that a significant reduction in rotor inertia and bearing drag relative to conventional CFG configurations is provided. The present architecture creates virtually zero rotating moment.

Abstract: Compliant mounting systems, devices, and methods for mounting a vehicle engine to a vehicle structure or base include a top mount, a lower mount, a center trunnion mount, and an aft mount which are configured to react forces transmitted by the engine to the vehicle structure. Metallic and elastomeric elements can provide vibrational and force isolation characteristics. Stops (e.g., snubbing elements) allow for a specific range of motion before internal mount structures contact each other to act as a conventional hard mount. Fluid elements and compressible gas-filled spaces/bladders may be incorporated to provide fluid damping behaviors to complement the metallic and elastomeric elements.

Abstract: A magnetorheological fluid is provided having a reduced coefficient of friction and favorable settling characteristics. The fluid contains magnetically responsive particles, a carrier fluid, and an amine oleate salt.

Abstract: Dual action magnetic brakes and related methods are provided. In one aspect, such a brake includes a housing, a rotatable shaft extending through the housing, and a braking assembly in the housing. The braking assembly includes a coil and a braking member. The coil can generate a magnetic field when energized with electrical current. The braking member, and one or more flexible members attached thereto, can move in response to the presence or absence of the magnetic field to facilitate rotation or non-rotation of the shaft.