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Technical Paper

Simulation Environment for Modeling and Testing of Autonomous Assembly in Space for Multiple Robotic Arms

2022-03-08
2022-01-0012
Multi-arm robotic assembly in space is an increasingly popular research topic as robotic arms can be used to decrease repair costs. We propose a simulation framework to model different scenarios of multi-arm robotic assembly in space with an ever-changing harsh environment. Simulation is a valuable, viable, and low-cost option for testing the developed algorithms without the need to re-create the orbital conditions in an elaborate and expensive laboratory environment. The proposed simulation framework uses the open-source tools: ROS Kinetic and Gazebo 7. We propose a system where robotic arms coordinate and collaborate to drive a screw into a plate autonomously. A move-able robot with a 3D sensing camera maps the environment and, using image recognition and localization, notifies the arms of obstacles and the locations of the screw and plate models. The arms calculate a collision-free path to the model, grasp the object, and return to a shared location.
Technical Paper

Visualization Techniques for Simulation-Based Dependent Failure Analysis

2022-03-08
2022-01-0032
Failure analysis of engineering systems typically emphasises identification and mitigation under an independent failure assumption with dependent failures treated as the exception rather than the rule. Some frameworks for addressing dependent failures through analysis appear in standards including NUREG 0492, ISO 26262, MIL 1629 A, and ARP4761 amongst others. The purpose of identifying these dependencies is to allow system analysts to determine and quantify the factors that influence dependent fault probabilities. Once defined, failure relationships can be incorporated into a Discrete Event Simulation (DES) of the system, providing a mathematically rigorous estimate of system utility (e.g., availability, reliability). Nonetheless, the output of a simulation must not only provide an expected value of performance but also allow the analyst to identify the downstream impact of probabilistic dependencies between system elements.
Technical Paper

Integration of Big Data and Deep Learning for Weapon Combat Effectiveness

2022-03-08
2022-01-0030
This research paper deals with the importance of Weapon Combat Effectiveness (WCE) analytics and the difficulty in measuring this value in tandem with the added complexity of combat environments. This lack of acknowledgment has resulted in utilizing a limited number of scenarios and limiting other factors such as weapon system configurations. Our group has suggested that collecting big data through a federated Live-Virtual-Constructive (LVC) simulation architecture can provide a good assessment. Specifically, the goal is to intersect the areas of weapon combat effectiveness (WCE), defense modeling and simulation (DM&S), and defense with big data (DBD). This intersection will lead to new WCE analytics. However, our hypothesis goes beyond that: It is essential to use the advantages of deep learning to analyze noise, extrapolation, the vast depth of data, and the nonlinearities of data to enhance the analysis of VC simulations.
Technical Paper

Computer Aided Engineering-based Evaluation of a Purpose-built Tooling Concept for the Electroplating of Functional Coatings on Aerospace Components

2022-03-08
2022-01-0045
Industrial hard chrome plating is a rather complex, lengthy and labour-intensive process: typically, the low cathodic current efficiency of Cr plating baths results in limited deposition rates, taking an hour to deposit a thickness of 25 mm on any size of the part. In the majority of cases, the hard Cr plating process requires the use of tooling structures, making the process strongly operator-dependent and therefore, highly prone to errors. According to the Fokker Landing Gear BV team, operator-independence as well as process simplification are expected to be achieved by developing a purpose-built tooling concept. An intelligent support of employees in their increasingly complex work is also sought and thus far addressed by implementation of modern smart technologies. One of them is computer modeling and simulation, which enables to mirror the physical world in a virtual model.
Technical Paper

Accuracy Analysis for a Flow Line Process using a Mobile Holding Fixture for Machining CRFP Components

2022-03-08
2022-01-0041
The aerospace sector is challenged to produce airplanes more efficiently and resiliently in the future. This leads to an increasing demand for improving productivity and flexibility as well as providing solutions for sustainable developments. A bottleneck in production is the machining of large-scale components. Apart from the machining tasks, non-productive tasks like fixture adjustment, component handling, referencing and localization are performed within the machining station and can constitute up to 50% of the overall workload. In the UniFix project, Fraunhofer IFAM is participating in the development of a mobile fixture system for large-scale aircraft components, like vertical tail plane and landing flap components of the single aisle aircrafts.
Technical Paper

Towards an intelligent digital cabin twin to support an aircraft’s retrofit and base maintenance

2022-03-08
2022-01-0046
Aircraft are high value-adding and long-living assets, while aircraft cabins are expensive consumer products tailored to each customer. Vastly changing requirements and needs force aircraft holders regularly to instruct modifications to remain attractive on the market. Adaptations, modifications, and development of innovations are handled by multiple organizations, not by a central organization like the aircraft’s manufacturer or owner. Although the Continuing Airworthiness Management Organization manages all aircraft instance-specific documents as required by aviation regulations, their format and types of management differ. Besides, not all information that arises during a parts design phase is included. That means, overall, the consistent model-based maintenance of data within all phases of PLM up to disposal is not guaranteed.
Technical Paper

Air Data Calibration Flight Test Campaign Optimization Using CFD

2022-03-08
2022-01-0025
Derivative aircraft sharing nose geometry and air data sensors installations are expected to present similar air data calibration residual errors as they may share the Static Source Error Correction (SSEC). Although such results are somehow expected, the certification process requires evidences from flight tests and analyses. During the certification of a derivative model of a regional jet, Computational Fluid Dynamics (CFD) analyses have been conducted in order to evaluate the suitability of such tool for this problem. Both the basic and derivative models are assumed to share: (i) nose geometry; (ii) air data sensors positions and installation and (iii) Static Source Error Correction (SSEC). CFD simulations have been performed for different configurations and flight conditions. Results showed similarity of air data calibration residuals between basic and derivative models for several configurations, demonstrating the suitability of a CFD tool for certification purposes.
Technical Paper

Automatic segmentation of aircraft dents in point clouds

2022-03-08
2022-01-0022
Dents on the aircraft skin are frequent and may easily go undetected during airworthiness checks, as their inspection process is tedious and extremely subject to human factors and environmental conditions. Nowadays, 3D scanning technologies are being proposed for more reliable, human-independent measurements, yet the process of inspection and reporting remains laborious and time consuming because data acquisition and validation are still carried out by the engineer. For full automation of dent inspection, the acquired point cloud data must be analysed via a reliable segmentation algorithm, releasing humans from the search and evaluation of damage. This paper reports on two developments towards automated dent detention. The first is a method to generate a synthetic dataset of dented surfaces to train a fully convolutional neural network. Training machine learning algorithms need a substantial volume of dent data, which is not readily available.
Technical Paper

CFD Numerical Simulation Aero-engine Air-Oil Separator

2022-03-08
2022-01-0027
Aero-engine oil systems drive and de-aerate air-oil in a two-phase flow in order to provide an applicable oil lubrication in aero-engine component and system. The oil lubrication systems combine three important functions of the Main Oil Pump (MOP) for lubrication and scavenging: the de-aeration and de-oiling of the air-oil mixture generated in the bearing and gearbox sumps, and pumping the oil towards the tank. These are critical functions for the aero-engine. An aero-engine lubrication system and an integrated pump and separation of gas-liquid mixture has been developed and characterized experimentally to increase Collins Aerospace Engine and Control Systems research and development productivity, as well as engine reliability and system performance. Collins Aerospace pump and separator system is specially designed to handle air-oil mixtures generated in aero-engine lubrication systems.
Technical Paper

Feasibility study of using liquid hydrogen tanks as energy carriers and cooling agents for a small aircraft

2022-03-08
2022-01-0009
Restrictions on emissions have been put to guide society into a more sustainable development in recent years. The impasse between regulations and the expectation of a growing demand for aviation exposes the need for decarbonization of the sector. In this way, investigations on innovative technologies arise, and the utilization of hydrogen associated with fuel cells stands out as they can operate with no emissions during flight. This study evaluates the feasibility of using liquid hydrogen (LH2) tanks as both energy sources and cooling agents for a small aircraft with electric propulsion. First, a propulsion system energized by a hybrid setup with Proton-Exchange Membrane Fuel Cells (PEMFC) and batteries is proposed for a small aircraft that currently operates with an Intern Combustion Engine (ICE). Then, this new module is integrated into the aircraft and its performance is simulated using SUAVE tool, allowing the evaluation of this aircraft version.
Technical Paper

Numerical Investigation of the NASA High-Lift Airfoil with a Conformal Vortex Generator at Transonic Speed

2022-03-08
2022-01-0034
Numerical investigation of airflow at a transonic speed over the wing of the NASA high-lift Common Research Model (CRM) with and without a conformal vortex generator (CVG), placed on the airfoil suction side has been performed. The objective of the investigation was to assess the impact of CVG on the wing’s lift to drag (L/D) ratio and tip vortices. The wing has aspect and taper ratios of respectively 9, and 0.275, and a leading-edge sweep angle of 37.24 degrees. The root and tip chords were respectively 11.81m and 2.73 m with an approximate mean chord of 6.62 m. The CVG was distorted V-shaped with a base distance of approximately 4.8 cm, depth of 8.8 cm, and a tip-to root angle of approximately 30.2⁰. The CVG is on both sides of the tape pointing in opposite directions. The tape is 2 mm thick, 83 cm wide, spanning the entire length of the wing surface. The leading edge of the CVG tape starts at 60% of the chord from the leading edge of the airfoil.
Technical Paper

Modeling Compressor Pressure Ratio vs. Mass Flow Rate Map Including Choke line and Surge line Using Scaling Theorem and Physics-based Methods

2022-03-08
2022-01-0029
The production of a compressor map for turbocharged engine was important for turbocharger and engine design. After the production of the compressor map, the engine performance can be simulated and analyzed, and the powertrain design can be more reliable. Below showed was a procedure to obtain the compressor map (pressure ratio vs. mass flow rate) from scaling of the available compressor family with similar shape and design based on scaling theorem. In this paper, a compressor scaling model was established through a series of compressors. The non-dimensional compressor head coefficient vs. mass flow coefficient was modelled. According to the scaling law, such scaling model was universal for the similar family compressors with similar shape and design. As a result, the compressor pressure ratio and mass flow rate can be deducted from those non-dimensional parameters. After the compressor scaling model was established, a process to select the compressor for engine application was showed.
Technical Paper

Prediction of Residual Stresses in Direct Metal Laser Sintering of Ti-6Al-4V Alloy by Numerical simulation

2022-03-08
2022-01-0047
This paper presents the efforts made in numerical simulation of residual stresses that are induced in Direct Metal Laser Sintering (DMLS) of Ti-6Al-4V alloy structures. The DMLS process is one of the Additive manufacturing processes that is widely used in the manufacturing of metal bodies used in automotive, aerospace and medical applications. However, the major challenge faced in this process is residual stresses that are caused by large thermal gradients. The DMLS manufactured Ti-6Al-4V has lower ductility when compared to hot work ad martensite structure formed due to the rapid solidification. Residual stresses imposed in them are a key contributor to these characteristics, Despite the fact that post-processing techniques such as hot working can alleviate some of the stresses, Some residual stress effects, like as warping and thermal stress-related cracking, are unaffected by post-processing.
Technical Paper

Development of Exfoliated Graphite using Innovative Chemical Technique for Aerospace Applications

2022-03-08
2022-01-0051
Several conventional methods on preparation of exfoliated graphite are in practice. However, their major limitations are poor quality of exfoliated graphite, lower yield, more expensive with higher processing time. To address these issues, a unique method for development of exfoliation of graphite using tri-solvents namely Water, Ethanol and Acetic acid is attempted in the present work. Ethanol acts as a supporting group for the long term stable dispersions of ex-graphite nanosheets. Glacial acetic acid, which readily dissolves in water, penetrates through the layers of graphite sheets and breaks the -C=C bond force between layers with the help of stirring and sonication resulting in exfoliation of graphite layers. Exfoliated graphite nanosheets were produced by using optimized mixtures of water, acetic acid and ethanol. XRD, SEM and FTIR studies have been carried out on the developed exfoliated graphite.
Technical Paper

Predictive Energy Management for Dual Motor-Driven Electric Vehicles

2022-02-14
2022-01-7006
Developing pure electric powertrains have become an important way to reduce reliance on crude oil in recent years. This paper concerns energy management of dual motor-driven electric vehicles. In order to obtain a predictive energy management strategy with good performance in computation and energy efficiency, we propose a hybrid algorithm that combines model predictive control (MPC) and convex programming to minimize electrical energy use in real time control. First, few changes are occurred in original component models in order to convert the original optimal control problem into convex programming problem. Then convex optimization algorithm is used in the prediction horizon to optimize torque allocation between two electric motors with different size. To verify the effectiveness of the hybrid algorithm, a real city driving cycle is simulated. Furthermore, different predictive horizons are performed to illustrate the robustness and time efficiency of the proposed method.
Technical Paper

Shadow Casting Influence on Solar Panel Locations and Configurations for an Electric Scooter (Scuddy)

2022-01-11
2022-01-5003
The electric vehicle was known to have caused range anxiety to some potential car buyers due to the battery limitations. One of the solutions was to install solar panels on a small vehicle that can charge the battery throughout the day. This project was to study the best position and configuration of the solar panel based on the sunlight reception on an electric scooter (Scuddy). Three locations were considered for this study: handle position, front-wheel position, and rear-wheel position. The other parameters considered in this study were the rider’s standing and sitting position, solar panel mount angle, the time during the day, and the direction heading of the electric scooter. The results showed that the solar panel at the handle gave the highest average sunlight exposure, 96% throughout the day and heading. The rider’s sitting and standing position also influenced the sunlight exposure amount, especially when the solar panel was located at the electric scooter’s rear wheel.
Technical Paper

Slope Starting Control of Off-Road Vehicle with 32-Speed Binary Logic Automatic Transmission

2022-01-03
2022-01-5001
Taking an off-road vehicle equipped with 32-speed binary logic automatic transmission (AT) as the research object, the slope starting control research is carried out. The slope starting process is divided into the overcoming resistance stage, the sliding friction stage, and the synchronization stage. The control strategies for each stage are designed respectively. Focusing on the control of the sliding friction stage, the equivalent two-speed model of the starting clutch is established, which realizes the calculation of the speed difference and the slip rate between the driving and driven ends of the starting clutch. Furthermore, the slope starting control strategy based on the proportional-integral-derivative (PID) control of the clutch slip rate is designed. Through the simulation tests of the vehicle starting at different slopes, the correctness of the slope starting control strategy has been verified by MATLAB/Simulink.
Technical Paper

Design and Development of a 10kW-Class Fuel Cell Test Platform for Sub-Freezing Environment

2021-12-31
2021-01-7002
Proton exchange membrane fuel cell has received extensive attention from different industries due to its advantages such as high efficiency, high energy density, and clean emissions. However, performance at low temperature is still one of the key factors that restricted its wide commercialization. To study the internal water state of the fuel cell at low temperature and verify different cold-start strategies, a fuel cell test platform that can simulate a low-temperature environment is needed. As the power of the stack grows, the impact of the size of a membrane and the impact of the number of single cells can’t be negligible. Meanwhile, the mutual influence between adjacent single cells at low temperatures is also worth studying. However, a test platform for high-power fuel cell stack with the ability to simulate a sub-freezing temperature is currently lacking. Thus, in this work, a 10kW-class fuel cell test platform is designed.
Technical Paper

Improving Combustion Performance of a Dedicated Range-Extender Engine with Refined Intake-Charging Characteristics and Cooled EGR

2021-12-31
2021-01-7001
Studies were carried out for improvement of combustion performance of an 1.2 L dedicated range-extender gasoline engine which uses a high compression ratio, cooled exhaust-gas-recirculation (EGR) and Atkinson cycle. The intake-charging characteristics were investigated both computationally and experimentally in order to compensate the torque reduction mainly due to the charge pushback in the Atkinson cycle. The design parameters of the intake manifold were refined to increase the intake air charges. 1D simulations were carried out to investigate the effect of the runner lengths and diameters. The results indicated that the increased length and reduced diameter could improve the volumetric efficiency in the most used engine speed range. Furthermore, computational fluid dynamics (CFD) simulations were employed to evaluate the cylinder-to-cylinder charging variations of the proposed manifold and reduced variations were obtained.
Technical Paper

Traffic Flow Velocity Prediction Based on Real Data LSTM Model

2021-12-31
2021-01-7014
In order to improve the energy efficiency of hybrid electric vehicles and to improve the effectiveness of energy management algorithms, it is very important to predict the future changes of traffic parameters based on traffic big data, so as to predict the future vehicle speed change and to reduce the friction brake. Under the framework of deep learning, this paper establishes a Long Short-Term Memory (LSTM) artificial neural network traffic flow parameter prediction model based on time series through keras library to predict the future state of traffic flow. The comparison experiment between Long Short-Term Memory (LSTM) artificial neural network model and Gate Recurrent Unit (GRU) model using US-101 data set shows that LSTM has higher accuracy in predicting traffic flow velocity.
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