Aerospace Mechanisms and Actuation

A special issue of Actuators (ISSN 2076-0825). This special issue belongs to the section "Aircraft Actuators".

Deadline for manuscript submissions: 31 March 2024 | Viewed by 23881

Special Issue Editor

Special Issue Information

Dear Colleagues,

Modern commercial transport aircraft relies on complex aerodynamic mechanisms and sophisticated flight control systems to achieve and maintain optimal flight performance at different flight regimes. Typically deployed hydraulically or with servos, aircraft high-lift devices, for instance, consist of moveable mechanical assemblies which are highly optimized to increase the amount of lift produced by the wing during take-off and landing. The design of such complex systems typically starts from the kinematic synthesis of the mechanisms and the preliminary design of the actuation architecture in a multidisciplinary and multiobjective context involving aerodynamic, system, and structural design.

This Special Issue on “Aerospace Mechanisms and Actuation” aims to provide a premier international platform for a wide range of professions, including researchers, academicians, and industry experts to discuss the latest advances in aerospace mechanisms, spanning from rigid-body linkages to flexible compliant members, and major achievements in the related research on both discrete and distributed actuation architectures. Focus will also be given to the evolution of actuation in aerospace by including full electrical drives for safety-critical commercial and military aircraft, helicopters, and space applications.

Dr. Ignazio Dimino
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

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Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • High-lift devices and other aerospace applications
  • Rigid-body mechanisms
  • Compliant mechanisms 
  • Centralized and distributed actuation architectures 
  • Conventional (mechanically signaled and hydraulically supplied)
  • EMA and full electrical actuation
  • Design methodologies and optimization 
  • Multibody simulations 
  • Non-linear mechanics 
  • Manufacturing, integration, and maintenance 
  • Safety and reliability

Published Papers (11 papers)

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Research

18 pages, 5305 KiB  
Article
Modeling of Precise Tension with Passive Dancers for Automated Fiber Placement
Actuators 2024, 13(2), 70; https://doi.org/10.3390/act13020070 - 12 Feb 2024
Viewed by 357
Abstract
This paper modeled the tension fluctuation during automated fiber placement (AFP), which depicted the tension variations under different operating conditions. The stability and validity of the model were demonstrated using Bode plots and experiments, respectively. According to the model, the tension fluctuations of [...] Read more.
This paper modeled the tension fluctuation during automated fiber placement (AFP), which depicted the tension variations under different operating conditions. The stability and validity of the model were demonstrated using Bode plots and experiments, respectively. According to the model, the tension fluctuations of AFP at different stages were obtained. Additionally, the passive dancer parameters with the better system performance were determined using the evaluation methodology presented in this paper. Moreover, it was discovered that the damping coefficient affects the tension variation more significantly than the elasticity coefficient. Finally, the placement experiments showed that the determined passive dancer parameters improved the laying quality significantly. Full article
(This article belongs to the Special Issue Aerospace Mechanisms and Actuation)
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27 pages, 24165 KiB  
Article
Multi-Objective Optimization for Forming Quality of Laser and CMT-P Arc Hybrid Additive Manufacturing Aluminum Alloy Using Response Surface Methodology
Actuators 2024, 13(1), 23; https://doi.org/10.3390/act13010023 - 08 Jan 2024
Viewed by 828
Abstract
A thin-walled structure of high-strength aluminum alloy 2024 (AA2024) was fabricated using novel laser and cold metal transfer and pulse (CMT-P) arc hybrid additive manufacturing (LCAHAM) technology. The influence of the wire feeding speed, scanning speed, and laser power on the forming quality [...] Read more.
A thin-walled structure of high-strength aluminum alloy 2024 (AA2024) was fabricated using novel laser and cold metal transfer and pulse (CMT-P) arc hybrid additive manufacturing (LCAHAM) technology. The influence of the wire feeding speed, scanning speed, and laser power on the forming quality was systematically studied by the response surface methodology, probability statistical theory, and multi-objective optimization algorithm. The result showed that the forming accuracy was significantly more affected by the laser power than by the wire feeding speed and scanning speed. Specifically, there was an obvious correlation between the interaction of the laser power and wire feeding speed and the resulting formation accuracy of LCAHAM AA2024. Moreover, the laser power, wire feeding speed, and scanning speed all had noticeable effects on the spattering degree during the LCAHAM AA2024 process, with the influence of the laser power surpassing that of the other two factors. Importantly, these three factors demonstrated minimal mutual interaction on spattering. Furthermore, the scanning speed emerged as the most significant factor influencing porosity compared to the wire feeding speed and laser power. It was crucial to highlight that the combined effects of the wire feed speed and laser power played an obvious role in reducing porosity. Considering the forming accuracy, spattering degree, and porosity collectively, the recommended process parameters were as follows: a wire feeding speed ranging from 4.2 to 4.3 m/min, a scanning speed between 15 and 17 mm/s, and a laser power set at approximately 2000 W, where the forming accuracy was 84–85%, the spattering degree fell within 1.0–1.2%, and the porosity was 0.7–0.9%. Full article
(This article belongs to the Special Issue Aerospace Mechanisms and Actuation)
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27 pages, 6846 KiB  
Article
Nonlinear Modeling and Analysis of Wound-Rotor Synchronous Starter/Generator (WRSSG) in Generating State for More Electric Aircraft
Actuators 2023, 12(12), 439; https://doi.org/10.3390/act12120439 - 25 Nov 2023
Viewed by 981
Abstract
The nonlinear modeling and analyzing of wound-rotor synchronous starter/generators (WRSSGs) plays a vital role in the analysis and monitoring of aircraft power systems. Moreover, they are of great significance with regard to the establishment of a future aircraft smart grid. However, owing to [...] Read more.
The nonlinear modeling and analyzing of wound-rotor synchronous starter/generators (WRSSGs) plays a vital role in the analysis and monitoring of aircraft power systems. Moreover, they are of great significance with regard to the establishment of a future aircraft smart grid. However, owing to its nonlinear, high-dimensional, and strong coupling characteristics, this modeling has always remained in the frequency domain stage and the progress of more intuitive time domain modeling has been slow. This paper presents a nonlinear model of a WRSSG in a generating state. When the WRSSG is in power generation mode, most cases indicate that the aircraft is in flight mode. The establishment of the nonlinear model of the system in the power generation state is of great significance for the research of the health management and state monitoring of the aircraft power system and can improve the safety and reliability of the aircraft during flight. The model uses FE analysis and neural network to solve the nonlinear problem of the motor in the system and uses the improved variable parameter average model to solve the nonlinear problem of the rotating rectifier. According to the principle of signal transmission, a time domain model for the whole system is developed. Finally, the model is compiled by the RT-LAB real-time simulator. The nonlinear model performs well when compared with FE analysis results and tested against the MIL-STD-704F standard. The proposed nonlinear model and analysis results can be used for the condition monitoring and fault diagnosis of aircraft power systems. The hardware-in-the-loop test platform based on an accurate nonlinear model is a feasible means to study the failure of expensive equipment, and it can aid the study of irreversible failures of equipment at a low cost. Full article
(This article belongs to the Special Issue Aerospace Mechanisms and Actuation)
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17 pages, 2571 KiB  
Article
Design and Optimization of an Active Leveling System Actuator for Lunar Lander Application
Actuators 2022, 11(9), 263; https://doi.org/10.3390/act11090263 - 13 Sep 2022
Cited by 2 | Viewed by 2110
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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10 pages, 6733 KiB  
Article
A Hybrid Control Strategy for a PMSM-Based Aircraft Cargo Door Actuator
Actuators 2022, 11(9), 256; https://doi.org/10.3390/act11090256 - 08 Sep 2022
Viewed by 2072
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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13 pages, 6114 KiB  
Article
Preliminary Assessment of an FBG-Based Landing Gear Weight on Wheel System
Actuators 2022, 11(7), 191; https://doi.org/10.3390/act11070191 - 14 Jul 2022
Cited by 2 | Viewed by 2670
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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23 pages, 5729 KiB  
Article
Study on the Actuation Aspects for a Morphing Aileron Using an Energy–Based Design Approach
Actuators 2022, 11(7), 185; https://doi.org/10.3390/act11070185 - 07 Jul 2022
Cited by 2 | Viewed by 1744
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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12 pages, 2714 KiB  
Article
Fault Diagnosis for Aircraft Hydraulic Systems via One-Dimensional Multichannel Convolution Neural Network
Actuators 2022, 11(7), 182; https://doi.org/10.3390/act11070182 - 02 Jul 2022
Cited by 5 | Viewed by 2145
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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36 pages, 31734 KiB  
Article
Multidisciplinary Optimization for Weight Saving in a Variable Tapered Span-Morphing Wing Using Composite Materials—Application to the UAS-S4
Actuators 2022, 11(5), 121; https://doi.org/10.3390/act11050121 - 27 Apr 2022
Cited by 4 | Viewed by 2803
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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18 pages, 8748 KiB  
Article
A Fault Diagnosis Approach for Electromechanical Actuators with Simulating Model under Small Experimental Data Sample Condition
Actuators 2022, 11(3), 66; https://doi.org/10.3390/act11030066 - 22 Feb 2022
Cited by 5 | Viewed by 2399
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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16 pages, 7674 KiB  
Article
Topology Optimization of Large-Scale 3D Morphing Wing Structures
Actuators 2021, 10(9), 217; https://doi.org/10.3390/act10090217 - 31 Aug 2021
Cited by 16 | Viewed by 3449
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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