Moog Inc.

About: Moog Inc. is a company organization based out in East Aurora, New York, United States. It is known for research contribution in the topics: Signal & Actuator. The organization has 391 authors who have published 411 publications receiving 4932 citations.

Variable stiffness composite panels : Effects of stiffness variation on the in-plane and buckling response

Abstract: Descriptions of fiber orientation variation for flat rectangular composite laminates that possess variable stiffness properties are introduced. The simplest definition employs a unidirectional variation based on a linear function for the fiber orientation angle of the individual layers. Analyses of variable stiffness panels for in-plane and buckling responses are developed and demonstrated for two distinct cases of stiffness variations. The first case assumes a stiffness variation in the direction of the loading, and numerical results indicate small improvements in buckling load for some panel configurations due to favorable distribution of the transverse stresses over the panel planform. The second case varies the stiffness perpendicular to the loading, and provides a much higher degree of improvement due to the re-distribution of the applied loads. It is also demonstrated that the variable stiffness concept provides a flexibility to the designer for trade-offs between overall panel stiffness and buckling load, in that there exist many configurations with equal buckling loads yet different global stiffness values, or vice versa.

A model-based approach to prognostics and health management for flight control actuators

Abstract: Impact technologies have developed a robust modeling paradigm for actuator fault detection and failure prediction. This model-based approach to prognostics and health management (PHM) applies physical modeling and advanced parametric identification techniques, along with fault detection and failure prediction algorithms, in order to predict the time-to-failure for each of the critical, competitive failure modes within the system. Advanced probabilistic fusion strategies are also leveraged to combine both collaborative and competitive sources of evidence, thus producing more reliable health state information. These algorithms operate only on flight control command/response data. This approach for condition-based maintenance provides reliable early detection of developing faults. As an advantage over 'black-box' health-monitoring schemes, faults and failure modes are traced back to physically meaningful system parameters, providing the maintainer with invaluable diagnostic and prognostic information. The developed model-based reasoner was validated and demonstrated on an electromechanical actuator (EMA) provided by Moog, Inc.

Modeling, Detection, and Disambiguation of Sensor Faults for Aerospace Applications

Abstract: Sensor faults continue to be a major hurdle for systems health management to reach its full potential. At the same time, few recorded instances of sensor faults exist. It is equally difficult to seed particular sensor faults. Therefore, research is underway to better understand the different fault modes seen in sensors and to model the faults. The fault models can then be used in simulated sensor fault scenarios to ensure that algorithms can distinguish between sensor faults and system faults. The paper illustrates the work with data collected from an electromechanical actuator in an aerospace setting, equipped with temperature, vibration, current, and position sensors. The most common sensor faults, such as bias, drift, scaling, and dropout were simulated and injected into the experimental data, with the goal of making these simulations as realistic as feasible. A neural network-based classifier was then created and tested on both experimental data and the more challenging randomized data sequences. Additional studies were also conducted to determine sensitivity of detection and disambiguation efficacy with respect to severity of fault conditions.

Removable adapter for phacoemulsification handpiece having irrigation and aspiration fluid paths

Abstract: Current phacoemulsification handpieces require rigorous cleaning after each procedure because the aspiration and irrigation pathways for fluids are integral to the handpiece. According to the present invention, a removable horn extension and nosecone may be used with a phacoemulsification handpiece to allow for disposable fluid pathways exterior to the handpiece. This will reduce the cleaning time and effort, reduce cross-contamination, and increase the lifespan of the handpiece. Furthermore, the current invention allows different horn extensions to be used to excite different motions at the tip of the handpiece, depending on the preference of the surgeon.

Method and apparatus for actively adjusting and controlling a resonant mass-spring system

Abstract: An actively-controlled resonant-type force generator (20) is adapted to be attached to a structure (21), and includes a mass (23) mounted for movement relative to the structure and a plurality of springs (22, 24) operatively arranged between the mass and the structure. A servoactuator (26) is arranged to controllably excite the mass-spring system. The actual force (F a ) transmitted from the mass to the structure is compared with a commanded force (F c ) to produce a force error signal (F e ). The actuator is caused to produce a velocity as a function of the error signal. The gain of the closed force loop is selected so that the resonance of the mass-spring system has an effective damping ratio (ζ) greater than about 0.5, and preferably about 0.7. Thus, the mass-spring system will not be substantially resonantly excited by vibrations of the structure near its resonant frequency (ω n ).