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Open AccessArticle

Design and Optimization of an Active Leveling System Actuator for Lunar Lander Application

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Actuators 2022, 11(9), 263; https://doi.org/10.3390/act11090263 - 13 Sep 2022

Cited by 1 | Viewed by 1098

Abstract

This work proposes a systematic methodology for designing an active leveling system (ALS) actuator for lunar landing application. The ALS actuator is integrated into an inverted tripod leg layout, exploiting a honeycomb crushable damper as a shock absorber. The proposed ALS actuator is [...] Read more.

This work proposes a systematic methodology for designing an active leveling system (ALS) actuator for lunar landing application. The ALS actuator is integrated into an inverted tripod leg layout, exploiting a honeycomb crushable damper as a shock absorber. The proposed ALS actuator is fitted within the leg’s primary strut and features a custom permanent-magnet synchronous machine rigidly coupled with a lead screw. The actuator aims to both provide proper leg deployment functioning and compensate for the different shock absorber deformations during landing. The leg dynamic behavior is simulated through a parameterized multi-body model to investigate different landing scenarios. First, a parametric sensitivity approach is used to optimize the transmission system and the electric machine characteristics. Then, the electric motor model is numerically validated and optimized through electromagnetic finite element analysis. To validate the proposed ALS design methodology, a virtual test bench is used to assess the ALS performances under different load scenarios. It is found that the proposed methodology is able to yield a compact, well-sized actuator which is numerically validated with the EL3 platform as a case study. Full article

(This article belongs to the Special Issue Aerospace Mechanisms and Actuation)

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Open AccessArticle

A Hybrid Control Strategy for a PMSM-Based Aircraft Cargo Door Actuator

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Actuators 2022, 11(9), 256; https://doi.org/10.3390/act11090256 - 08 Sep 2022

Viewed by 1061

Abstract

There are some disadvantages of a traditional AC-induced motor or hydraulic cylinder-based aircraft cargo door actuator (CDA), such as strong stopping shock, big slippage, high power, or current demand. To solve these problems, a permanent magnet synchronous motor (PMSM)-based linear CDA has been [...] Read more.

There are some disadvantages of a traditional AC-induced motor or hydraulic cylinder-based aircraft cargo door actuator (CDA), such as strong stopping shock, big slippage, high power, or current demand. To solve these problems, a permanent magnet synchronous motor (PMSM)-based linear CDA has been developed, and a hybrid control method combining speed plan and control, power current restriction has been proposed. In other words, low-speed-loop servo control is used in opening and closing positions, and power restricted control is adopted otherwise. A multidisciplinary model is constructed with Simulink. The simulation results show that vibration and slippage are reduced dramatically for the cargo door mechanism, and power is restricted during the whole procedure, which also results in good adaptability performance over a wide range of loads and temperatures. Experiments with different load levels on a test rig and in a temperature chamber at −50 °C are implemented to verify the effectiveness of the strategy. Full article

(This article belongs to the Special Issue Aerospace Mechanisms and Actuation)

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Open AccessArticle

Preliminary Assessment of an FBG-Based Landing Gear Weight on Wheel System

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Actuators 2022, 11(7), 191; https://doi.org/10.3390/act11070191 - 14 Jul 2022

Viewed by 1035

Abstract

Weight-on-Wheels (WoW) systems are aimed at indicating if the aircraft weight is loading onto the landing gear and its wheels, even partially. These systems are an integral part of the actuation system for safety-critical applications and shall provide reliable information on the actual [...] Read more.

Weight-on-Wheels (WoW) systems are aimed at indicating if the aircraft weight is loading onto the landing gear and its wheels, even partially. These systems are an integral part of the actuation system for safety-critical applications and shall provide reliable information on the actual operational status of the LG. That information reveals if the vehicle is in flight or on the ground. In this way, several kinds of accidents may be prevented, relating for instance, to the incorrect deployment of the landing gear, or even manoeuvres to a certain extent, therefore protecting the aircraft from dangerous damage. There are different architectures that have been proposed in the bibliography, some of them based on strain gauges deployed on the structure, or on proximity sensors installed on the wheels. Being this device and considered critical for safety, it is convenient to couple it with complementary measurements, recorded and processed by different sources. In general, it can be stated that such an intelligent sensor network may be seen as a fundamental support for proper landing gear deployment. The presented paper reports the results of a preliminary investigation performed by the authors to evaluate the possibility of deploying fibre optics on the landing gear structure as part of a WoW system to retrieve the required information. This choice would have a remarkable effect in terms of significant cabling reduction (a single array of sensing elements could be deployed over a single line), and cost abatement from both a manufacturing and operational point of view. There are many other benefits also when referring to an optical instead of a standard electrical sensor system. Due to its small size and ease of integration into different families of materials, it could be considered a system for monitoring the operating status of most actuators on board modern aircraft. Full article

(This article belongs to the Special Issue Aerospace Mechanisms and Actuation)

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Open AccessArticle

Study on the Actuation Aspects for a Morphing Aileron Using an Energy–Based Design Approach

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Alessandro De Gaspari

Actuators 2022, 11(7), 185; https://doi.org/10.3390/act11070185 - 07 Jul 2022

Viewed by 962

Abstract

Evaluating the impact of morphing devices in terms of actuation energy is a promising approach to quantify, from the earliest stages of wing design, the convenience of active camber morphing compared to the use of conventional control surfaces. A morphing wing device consists [...] Read more.

Evaluating the impact of morphing devices in terms of actuation energy is a promising approach to quantify, from the earliest stages of wing design, the convenience of active camber morphing compared to the use of conventional control surfaces. A morphing wing device consists of an adaptive structure coupled with an actuation system. The starting point for the design of the adaptive structure is a three-dimensional parametric-geometry-representation technique working on the definition of the external morphing shape. The morphing shape is defined to be feasible from the structural point of view and able to meet the aerodynamic design requirements. The new method presented here enables the computation of the actuation energy as a combination of strain energy and external aerodynamic work. The former is the energy required to deform the skin and can be computed in an analytical way, based on the same quantities used by the parameterization technique. The latter is used to compute the energy needed to counteract the external aerodynamic loads during the deformation. This method is applied to the design optimization of a morphing aileron which is installed on a 24 m span wing, starts at 65% of both the chord and the semi-span and extends for one third of the span. A parametric study shows the superiority of the morphing aileron, compared with an equivalent hinged aileron, in terms of energy saving, weight penalty reduction and ease of on-board installation. The morphing aileron is more compact and requires a lower actuation energy combined with a lower deflection, while providing the same roll moment. Full article

(This article belongs to the Special Issue Aerospace Mechanisms and Actuation)

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Open AccessArticle

Fault Diagnosis for Aircraft Hydraulic Systems via One-Dimensional Multichannel Convolution Neural Network

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Kenan Shen

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Dongbiao Zhao

Actuators 2022, 11(7), 182; https://doi.org/10.3390/act11070182 - 02 Jul 2022

Cited by 2 | Viewed by 1171

Abstract

Detecting the faults in hydraulic systems in advance is difficult owing to the complexity associated with such systems. Hence, it is necessary to investigate the different fault modes and analyze the system reliability in order to establish a method for improving the reliability [...] Read more.

Detecting the faults in hydraulic systems in advance is difficult owing to the complexity associated with such systems. Hence, it is necessary to investigate the different fault modes and analyze the system reliability in order to establish a method for improving the reliability and security of hydraulic systems. To this end, this paper proposes a novel one-dimensional multichannel convolution neural network (1DMCCNN) for diagnosing fault modes. In this work, a landing gear hydraulic system was constructed with a normal model and a fault model; five types of faults were considered. Pressure signals were extracted from this hydraulic system, and the extracted signals were subsequently input into the convolution neural network (CNN) as multichannel data. Thereafter, the data were subjected to a one-dimensional convolution filter. The differences between channels were used to enhance features. The features obtained in this manner were compared for fault diagnoses. Furthermore, this proposed method was verified via simulations; the simulation results indicated that the precision of the 1DMCCNN was considerably higher than that of conventional machine learning algorithms. Full article

(This article belongs to the Special Issue Aerospace Mechanisms and Actuation)

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Open AccessArticle

Multidisciplinary Optimization for Weight Saving in a Variable Tapered Span-Morphing Wing Using Composite Materials—Application to the UAS-S4

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Mohamed Elelwi

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Felipe Schiavoni Pinto

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Ruxandra Mihaela Botez

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Thien-My Dao

Actuators 2022, 11(5), 121; https://doi.org/10.3390/act11050121 - 27 Apr 2022

Cited by 2 | Viewed by 1837

Abstract

This paper is a follow-up to earlier work on applying multidisciplinary numerical optimization to develop a morphing variable span of a tapered wing (MVSTW) to reduce its weight by using composite materials. This study creates a numerical environment of multidisciplinary optimization by integrating [...] Read more.

This paper is a follow-up to earlier work on applying multidisciplinary numerical optimization to develop a morphing variable span of a tapered wing (MVSTW) to reduce its weight by using composite materials. This study creates a numerical environment of multidisciplinary optimization by integrating material selection, structural sizing, and topological optimization following aerodynamic optimization results with the aim to assess whether morphing wing optimization is feasible. This sophisticated technology is suggested for developing MVSTWs. As a first step, a problem-specific optimization approach is described for specifying the weight-saving structure of wing components using composite materials. The optimization was performed using several approaches; for example, aerodynamic optimization was performed with CFD and XFLR5 codes, the material selection was conducted using MATLAB code, and sizing and topology optimization was carried out using Altair’s OptiStruct and SolidThinking Inspire solvers. The goal of this research is to achieve the MVSTW’s structural rigidity standards by minimizing wing components’ weight while maximizing stiffness. According to the results of this optimization, the weight of the MVSTW was reduced significantly to 5.5 kg in comparison to the original UAS-S4 wing weight of 6.5kg. The optimization and Finite Element Method results also indicate that the developedmorphing variable span of a tapered wing can complete specified flight missions perfectly and without any mechanical breakdown. Full article

(This article belongs to the Special Issue Aerospace Mechanisms and Actuation)

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Open AccessArticle

A Fault Diagnosis Approach for Electromechanical Actuators with Simulating Model under Small Experimental Data Sample Condition

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Actuators 2022, 11(3), 66; https://doi.org/10.3390/act11030066 - 22 Feb 2022

Cited by 2 | Viewed by 1525

Abstract

Electromechanical actuators (EMAs) have shown a high efficiency in flight surface control with the development of more electric aircraft. In order to identify the abnormalities and potential failures of EMA, a methodology for fault diagnosis is developed. A simulating model of EMA is [...] Read more.

Electromechanical actuators (EMAs) have shown a high efficiency in flight surface control with the development of more electric aircraft. In order to identify the abnormalities and potential failures of EMA, a methodology for fault diagnosis is developed. A simulating model of EMA is first built to perform different working states. Based on the modeling of EMA, the corresponding faults are then simulated to re-generate the fault data. Afterwards, a gated recurrent unit (GRU) and co-attention-based fault diagnosis approach is proposed to classify the working states of EMA. Experiments are conducted and a satisfying classification accuracy on simulated data is obtained. Furthermore, fault diagnosis on an actual working system is performed. The experimental results demonstrate that the proposed method has a high efficiency. Full article

(This article belongs to the Special Issue Aerospace Mechanisms and Actuation)

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Open AccessArticle

Topology Optimization of Large-Scale 3D Morphing Wing Structures

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Peter Dørffler Ladegaard Jensen

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Fengwen Wang

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Ignazio Dimino

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Ole Sigmund

Actuators 2021, 10(9), 217; https://doi.org/10.3390/act10090217 - 31 Aug 2021

Cited by 3 | Viewed by 2361

Abstract

This work proposes a systematic topology optimization approach for simultaneously designing the morphing functionality and actuation in three-dimensional wing structures. The actuation was modeled by a linear-strain-based expansion in the actuation material. A three-phase material model was employed to represent structural and actuating [...] Read more.

This work proposes a systematic topology optimization approach for simultaneously designing the morphing functionality and actuation in three-dimensional wing structures. The actuation was modeled by a linear-strain-based expansion in the actuation material. A three-phase material model was employed to represent structural and actuating materials and voids. To ensure both structural stiffness with respect to aerodynamic loading and morphing capabilities, the optimization problem was formulated to minimize structural compliance, while the morphing functionality was enforced by constraining a morphing error between the actual and target wing shape. Moreover, a feature-mapping approach was utilized to constrain and simplify the actuator geometries. A trailing edge wing section was designed to validate the proposed optimization approach. Numerical results demonstrated that three-dimensional optimized wing sections utilize a more advanced structural layout to enhance structural performance while keeping the morphing functionality better than two-dimensional wing ribs. The work presents the first step towards the systematic design of three-dimensional morphing wing sections. Full article

(This article belongs to the Special Issue Aerospace Mechanisms and Actuation)

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