Vacuum suction cups are used as transforming handles in stamping lines, which are essential in developing automation and mechanization. However, the vacuum suction cup will crack due to fatigue or long-term operation or installation angle, which directly affects production productivity and safety. The better design will help increase the cups' service life. If the location of stress concentration can be predicted, this can prevent the occurrence of cracks in advance and effectively increase the service life. However, the traditional strain measurement technology cannot meet the requirements of tracking large-field stains and precise point tracking simultaneously in the same area, especially for stacking or narrow parts of the suction cups. The application must allow multiple measurements of hidden component strain information in different fields of view, which would add cost. In this study, a unique multi-camera three-dimensional digital image correlation (3D-DIC) system was designed

Guo, Bicheng, Zheng, Xiaowan, Fang, Siyuan, Yang, Lianxiang

Medical Lasers: When the Laser Application Requires Utmost Safety

TBMG-4695111/01/2022

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SAE-PP-0668309/01/2022

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venkat, Aditya, SintzADMIn, Jeneane

Digital Manufacturing Execution System for Special Processes

2022-26-116805/26/2022

Processes like Chrome Conversion Coating, Painting, Temper ETCH are categorized as Special Process in Aerospace. They have many variables in the process which need to be monitored, recorded and inter relationship studied using ML & AI. Study of Process Parameters using IIoT, their impact on Quality and the impact on life cycle (Industry 4.0) due to the process parameters maintained at that time of manufacture needs specialized, customized software for each and every process. The said software needs to have checks and alerts for maintenance of Process parameters. It should, on a daily basis do a few lab measurements to cross check whether the automated measuring accuracy is correct or not. Regular empirical calculations for the concentration of baths should be done and an 'alarm' needs to be raised if any mismatch with actual measurement is found. This way regular checking of measuring instruments should be carried out. This also ensures that the issue is found out before it translates

Damodaran, Ramamurthy

Innovative vehicle battery pack design approach through multiphysics cells simulation

2022-01-030303/29/2022

This paper presents the design procedure of a vehicle battery pack, in terms of electrical and mechanical requirements with an innovative methodology to model Li-ion cells’ thermo-electro-mechanical behaviour. This modelling approach can predict, through FEM analysis, if short circuit happen with consequent generation of fire in case of vehicle crash. This last aspect has several issues related to the multiphysics characteristics of the phenomena due to the fact that battery cells are made up by really thin components and, as consequence, not significant works of an entire deformable battery pack simulation have been found in literature. For this reason, the design approach studied overcomes the classical methodology in which cells’ mechanical behaviour is considered unknown to understand if cell failure appears avoiding over-engineered battery pack structure. At the beginning, a benchmarking activity on existing FEM modelling methodologies of single cells has been conducted

Messana, Alessandro, Pioli, Federico, Savi, Matteo, Ferraris, Alessandro, Airale, Andrea, Carello, Massimiliana

Co-Simulation of BLDC Motor Control and Clutch actuation system with Ball Ramp Mechanism

2021-01-123609/21/2021

Electro-mechanical actuators are widely used in different forms in the automotive industry these days and are very effective in translating rotary motion of the motor to a linear motion with precision as per the requirement. With onset of electric drivelines and other complex driveline configurations, we see an increase in actuator applications. In this study, we developed high fidelity analytical model for a ball ramp clutch actuation system as per the proposed mechanical design and the software controls. The controls architecture is built in SIMULINK environment to drive the plant model of the BLDC motor. Whereas, the entire mechanical system which includes the gear train, ball ramp mechanism, clutch pack stiffness, etc. is modelled in ADAMS tool. The Ball Ramp consists of metal balls positioned in between opposing paired arc-shaped ramp grooves and guided by a cage to keep them equally separated in the same plane. While ADAMS model deals with high-fidelity contact dynamics using non

Rajendran, Raveen K., Roy, Nantu, Mehta, Yogesh

Development of a Non-Parametric Robot Calibration Method to Improve Drilling Accuracy

2021-01-000303/02/2021

The drilling of large quantities of repetitive holes during the manufacture of large aerospace components is often considered a key limiting factor with regards to production efficiency. Whilst the desire within aerospace is to use relatively cheap six axis robot arms with drilling end effector units, their poor accuracy remains an obstacle. Robot calibration presents a way of improving robot accuracy such that aerospace drilling tolerances can be met, without permanently committing metrology equipment to an automation cell during production. Extensive research has been conducted into robot calibration by correcting the kinematic model, known as parametric calibration. This method is highly complex, and calibrates the robot across the entire working volume. This is often not required in industrial drilling applications, as drilling routines are often contained within a smaller volume of the robot reach. In this paper, a non-parametric method of robot calibration is proposed. This

Scraggs, Chris, Smith, Thomas, Sawyer, Daniela, Davis, Matthew

Solenoid Valve Health Monitor

TBMG-3700506/01/2020

The Solenoid Valve Health Monitor System (SVHMS) was developed to remotely monitor the health of solenoid valves, lowering operational costs and increasing reliability by predicting valve failures before they occur. The system measures and analyzes steady state and transient components of the magnetic field and indirectly, the electric current in a solenoid valve during normal operation. It enables continuous monitoring of the integrity and operational status of solenoid valves without the need for interrupting their operation to conduct frequent inspections.

Optimization of Shifting Schedule of Vehicle Coasting Mode Based on Dynamic Mass Identification

2020-01-132104/14/2020

As an important vehicle state parameter, automotive mass has important reference value to the safety performance and comfort of automobiles. Current researches mostly focus on optimizing the established longitudinal dynamics model or improving the algorithm to reduce the recognition error. However, it often neglects that the longitudinal vibration caused by different driving speeds is very different, so the recognition rate is low under various complicated working conditions. In this paper, the speed decoupling model is firstly established to study the interference caused by the longitudinal vibration of the vehicle during the dynamic quality recognition. At the same time, the horizontal speed is decomposed from the combined speed. Then, several real vehicle tests are carried out at different gear speeds. The obtained gear speeds are decoupled and the results are brought into the longitudinal dynamics model. And the quality parameters are estimated by means of recursive least squares

Zhang, Boyang, Guo, Donghua

The Three Rs of Analog Position Sensor-Based Mechanical Measurements

TBMG-3568112/01/2019

Those of us old enough to remember the “good old days” recall that grade school focused on learning the 3 R's: reading, ‘riting, and ‘rithametic. In the world of sensors, there are also 3 R's: Repeatability, Resolution, and Response. As important as these sensor parameters are, there is often confusion in the mind of users about exactly what they mean and in what ways they tend to interact with each other. This article will attempt to explain the 3 R's for position sensors and dispel any confusion that might exist.

Reducing Vehicle Interior NVH by Means of Locally Resonant Metamaterial Patches on Rear Shock Towers

2019-01-150206/05/2019

Stringent regulations for CO2 emissions and noise pollution reduction demand lighter and improved Noise, Vibration Harshness (NVH) solutions in automotive industries. Designing light, compact and, at the same time, improved NVH solutions is often a challenge, as low noise and vibration levels often require heavy and bulky additions, especially to be effective in the low frequency regime. Recently, locally resonant metamaterials have emerged among the novel NVH solutions because of their performant NVH properties combined with lightweight and compact design. Due to the characteristic of stop band behavior, frequency ranges where free wave propagation is inhibited, metamaterials can beat the mass law, be it at least in some tunable frequency ranges. Previously the authors demonstrated how metamaterials can reduce the vibrations in a simplified shock tower upon shaker excitation. In this work, the authors apply the metamaterial concept on the real rear shock towers of a vehicle. In order

Sangiuliano, Luca, Claeys, Claus, Deckers, Elke, De Smet, Jasper, Pluymers, Bert, Desmet, Wim

Application of Simplified Load Path Models for BIW Development

2019-01-061404/02/2019

Simplified load path models (SLMs) of the body in white (BIW) are an important tool in the body structure design process providing a highly flexible, idealized concept model to explore the design space through load path evaluation, material selection, and section optimization with rapid turnaround. In partnership with Altair Engineering, the C123 process was used to create and optimize SLMs for BIW models at FCA US LLC. These models help structures engineers to develop efficient load paths, sections, and joints for improved NVH as ultra-high-strength steels enable thinner gauges throughout the body structure. A few key differences in the SLM modeling method are contrasted to previous simplified BIW modeling methods. One such example is the parameterization of cross sections through response surface models rather than using contemporary finite element descriptions of arbitrary cross sections. Another difference is the modeling of structural joints as 1-D spring elements rather than high

LeVett, Marshall, Truskin, James, Zagorski, Nicolas, Nelson, Eric

Neural Network Based Throttle Actuator Model for Controller

2019-26-024701/09/2019

HiL is a closed loop validation setup widely used in the validation of real-time control systems. In the existing HiL setup, the ECUs to be tested are real while the remaining vehicle is modelled as plant model using Simulink. But some actuators like throttle valve, waste-gate valve, injectors, etc. are not modelled as plant model. Since these actuators exhibit hard nonlinearity, it is difficult to design accurate models of these actuators. So these actuators are connected to the HiL as real hardware components. But the major drawbacks of using real hardware components are: they need more space and they are costly. Hence, in this work, a real-time throttle actuator model for the controller is proposed. A throttle actuator contains a DC motor and a spring loaded flap. To create an accurate ODE based model of the throttle actuator, parameter identification of each component of the throttle actuator needs to be done separately by dismantling the actuator. This approach needs more effort

Khasnabish, Neilay, Suggu, Dhanunjaya, Koppad, Ashwini

Measurement Data and Reference Values for Compounds Potentially Found in Aircraft Engine Bleed Air

AIR7521 (Current)10/09/2018

This document summarizes published measurement data and reference values for marker chemical compounds listed in ARP4418 (see 2.1.1) potentially found in aircraft engine bleed air.

E-31B Bleed Air Committee

Validation of Crush Energy Calculation Methods for Use in Accident Reconstructions by Finite Element Analysis

09-06-02-000910/04/2018

The crush energy is a key parameter to determine the delta-V in accident reconstructions. Since an accurate car crush profile can be obtained from 3D scanners, this research aims at validating the methods currently used in calculating crush energy from a crush profile. For this validation, a finite element (FE) car model was analyzed using various types of impact conditions to investigate the theory of energy-based accident reconstruction. Two methods exist to calculate the crush energy: the work based on the barrier force and the work based on force calculated by the vehicle acceleration times the vehicle mass. We show that the crush energy calculated from the barrier force was substantially larger than the internal energy calculated from the FE model. Whereas the crush energy calculated from the vehicle acceleration was comparable to the internal energy of the FE model. In full frontal impact simulations, the energy of approach factor (EAF) has a linear relation with the residual

Numata, Shusuke, Mizuno, Koji, Ito, Daisuke, Okumura, Dai

Numerical study on suspension parameters optimization for bus traveling on poor road condition

2018-36-006209/03/2018

This paper uses a multi-objective approach in order to optimize the suspension parameters of a bus traveling on poorly maintained runways. The objective functions chosen are the minimization of loads acting on the track and the RMS accelerations on the seat of three strategically positioned passengers on the bus. The numerical model of the bus has 13 degrees of freedom, including lateral dynamics, and the optimization is performed at a traveling speed of 40 km/h in a Double Lane Change (DLC) maneuver. The track is generated according to ISO 8606: 1995, described as class E. The model provides correlations between the sidetracks, and the dynamic interaction between the pavement and the tire is considered using the well-known model of Pacejka. Finally, the equations are solved in the time domain by the nonlinear Newmark method. The numerical model is coupled to a multi-objective optimization algorithm based on the Quantum Particle Swarm Optimization (MOQPSO) and to the well-known Non

Gomes, Herbert Martins, Grotti, Ewerton, Backes, Artur Dieguez, Freitas Awruch, Marcos Daniel de

Influence of the Wheatstone bridge configuration and the magnitude of the calibration weight in the uncertainty of the load measurement using a low-cost instrumentation

2018-36-019309/03/2018

The strain gauge (SG) is widely used for measurement of strains, or even of loads, in mechanical or structural components, mostly due to their low-cost, easy application and good accuracy. However, the literature is lacking in relation to studies concerning the determination of measurement uncertainty. This work presents a discussion of the influence of the SGs configuration in the Wheatstone bridge and the magnitude of the calibration weight applied to the measurement of load in a bending load (whose design is similar that used in load cells). Were compared ¼, ½ and full bridge configurations to linear SGs with 350Ω resistance. Low-cost instrumentation was used with the HX711 converter module and the Arduino microcontroller board. The measuring system was calibrated with two different weights: one of approximately 10% of the maximum value of the system operating range and another one of approximately 85%. Some conclusions can be highlighted, such as the influence of the amount of the

Lima, Pedro Henrique B. P. de, Silva, Gabriel César da, Guizelini, Igor Rafael, Vale, João Luiz do

Correcting the Antenna Temperature of an Earth-Observing Microwave Instrument for Extraterrestrial Contamination

TBMG-2972307/01/2018

Microwave antennas deployed for spaceborne radiometers are diffraction-limited, with typical beam efficiency of about 90%, and provide relatively poor selectivity against radiation from celestial bodies (Moon, Sun, galaxy) when they are at the side or back of the instrument. Traditionally, this contamination has been removed by preparing multiple data files that represent the relative position of the spacecraft and the celestial sources throughout the mission lifetime.

Efficient Vibro-Acoustic Optimisation of a Thermoplastic Composite Oil Pan

2018-01-148006/13/2018

Thermoplastic fibre reinforced composites offer a wide range of adjusting the material behaviour by varying material selection, layup and fibre orientation. By default, damping and stiffness of composites are contradictory material properties related to the fibre orientation. Thus, finite element analysis (FEA) based composite design requires special modelling efforts implying anisotropic damping of the composite as well as fluid-structure-inter-action for the oil filling. In contrast, multi-dimensional optimisations for various layups require computationally fast numerical solutions. In this study, a complex but efficient vibro-acoustic modelling approach of a composite oil pan is presented. The FEA model includes a strain energy based modal damping approach for the layerwise accumulation of the anisotropic composite damping as well as a structural representation of the additional mass of the oil filling avoiding fluid modelling. Moreover, the radiated sound power of the component is

Klaerner, Matthias, Wuehrl, Mario, Kroll, Lothar, Marburg, Steffen

In-Plane Flexible Ring Tire Model Parameter Identification: Optimization Algorithms

10-02-01-000505/03/2018

Parameter identification is an important part of tire model development. The prediction performance of a tire model highly depends on the identified parameter values of the tire model. Different optimization algorithms may yield different tire parameters with different computational accuracy. It is essential to find out which optimization algorithm is most likely to generate a set of parameters with the best prediction performance. In this study, four different MATLAB® optimization algorithms, including fminsearchcon, patternsearch, genetic algorithm (GA), and particleswarm, are used to identify the parameters of a newly proposed in-plane flexible ring tire model. The reference data used for parameter identification are obtained through a ADAMS FTire® virtual cleat test. After parameters are identified based on above four algorithms, their performances are compared in terms of effectiveness, efficiency, reliability, and robustness. Once the best optimization algorithm for the proposed

Li, Bin, Yang, Xiaobo, Yang, James

Optimizing Occupant Restraint Systems for Tactical Vehicles in Frontal Crashes

2018-01-062104/03/2018

The objective of this study was to optimize the occupant restraint systems for a light tactical vehicle in frontal crashes. A combination of sled testing and computational modeling were performed to find the optimal seatbelt and airbag designs for protecting occupants represented by three size of ATDs and two military gear configurations. This study started with 20 sled frontal crash tests to setup the baseline performance of existing seatbelts, which have been presented previously; followed by parametric computational simulations to find the best combinations of seatbelt and airbag designs for different sizes of ATDs and military gear configurations involving both driver and passengers. Then 12 sled tests were conducted with the simulation-recommended restraint designs. The test results were further used to validate the models. Another series of computational simulations and 4 sled tests were performed to fine-tune the optimal restraint design solutions. The sled tests with the

Hu, Jingwen, Ritchie Orton, Nichole, Chen, Cong, Reed, Matthew, Rupp, Jonathan, Gruber, Rebekah, Clark, David, Scherer, Risa

Simplifying the Structural Design of the Advanced Pedestrian Legform Impactor for Use in Standardized Testing

2018-01-104904/03/2018

The advanced Pedestrian Legform Impactor (aPLI) incorporates a number of enhancements for improved lower limb injury prediction capability with respect to its predecessor, the FlexPLI. The aPLI also incorporates a simplified upper body part (SUBP), connected to the lower limb via a mechanical hip joint, that expands the impactor’s applicability to evaluate pedestrian’s lower limb injury risk also in high-bumper cars.As the aPLI has been developed to be used in standardized testing, further considerations on the impactor’s manufacturability, robustness, durability, usability, and repeatability need to be accounted for.. The aim of this study is to define and verify, by means of numerical analysis, a battery of design modifications that may simplify the manufacturing and use of physical aPLIs, without reducing the impactors’ biofidelity. Eight candidate parameters were investigated in a two-step numerical analysis. One of the parameters was related to the SUBP structure, six to the

Isshiki, Takahiro, Antona-Makoshi, Jacobo, Konosu, Atsuhiro, Takahashi, Yukou

3D Vision Made Easy

TBMG-2812101/01/2018

Whether it is the industrial smart robot in the age of the Industrial Internet of Things (IIoT), using three-dimensional data to orient itself in its working space, the reverse vending machine counting empty bottles in a case, or the surface inspection system alerting personnel to the smallest material defect, three-dimensional information acquired by modern 3D sensors from the environment will be central to many industrial applications of the future.

Real Time Pose Control of an Industrial Robotic System for Machining of Large Scale Components in Aerospace Industry Using Laser Tracker System

2017-01-216509/19/2017

The high demand of efficient large scale machining operations by concurrently decreasing operating time and costs has led to an increasing usage of industrial robots in contrast to large scaled machining centers. The main disadvantage of industrial robots used for machining processes is their poor absolute accuracy, caused by the serial construction, resilience of gearings and sensitivity for temperature changes. Additionally high process forces that occur during machining of CFRP structures in aerospace industry lead to significant path errors due to low structural stiffness of the robot kinematic. These errors cannot be detected by means of motor encoders. That is why calibration processes and internal control laws have no effect on errors caused by elastic deformation. In this research paper an approach for increasing the absolute accuracy of an industrial milling robot with help of a Laser Tracker system during machining tasks will be presented. To measure the position and

Wollnack, Jörg, Moeller, Christian, Schmidt, Hans Christian, Koch, Philip, Boehlmann, Christian, Kothe, Simon, Hintze, Wolfgang

A Design Space Exploration Framework for Automotive Sound Packages in the Mid-Frequency Range

2017-01-175106/05/2017

The continuous pursuit for lighter, more affordable and more silent cars, has pushed OEMs into optimizing the design of car components. The different panels surrounding the car interior cavity such as firewall, door or floor panels are of key importance to the NV performance. The design of the sound packages for high-frequency airborne input is well established. However, the design for the mid-frequency range is more difficult, because of the complex inputs involved, the lack of representative performance metrics and its high computational cost. In order to make early decisions for package design, performance maps based on the different design parameters are desired for mid-frequencies. This paper presents a framework to retrieve the response surface, from a numerical design space of finite-element frequency sweeps. This response surface describes the performance of a sound package against the different design variables. In order to build it, a surrogate model is used based on a

Schaefer, Nicolas, Bergen, Bart, Keppens, Tomas, Desmet, Wim

Representation and Analysis of System Behavior Using Monotonic Signals

TBMG-2687805/01/2017

NASA has developed a new method for analyzing complex system behavior that also may be viewed as a type of data visualization and decision support tool. Large complex control systems may have thousands or even millions of sensors, each providing some type of signal that ultimately integrates into a larger organization. For each signal, behavior is represented by a sequence of pairs, with each pair containing a change value (monotonic) and a time interval length over which each of these changes occurs. Signal amplitudes and first derivatives serve as markers for these time intervals. This approach permits a finer scale characterization of the signal(s). The novelty of this approach is in using human visual interpretation in combination with computer signal analysis to monitor the behavior of complex systems in an enhanced manner.

In-Situ Load System for Calibrating and Validating Aerodynamic Properties of Scaled Aircraft in Ground-Based Aerospace Testing Applications

TBMG-2684405/01/2017

The in-situ load system (ILS) provides the ground-testing community with a comprehensive tool that permits system-level calibration and validation of force measurement systems in a test-like environment. It was developed to improve testing accuracy, repeatability, time in tunnel, and many aspects of the calibration process. The key innovations are that ILS enables a system calibration (rather than independent subsystem and component calibrations) by using the one-force-vector calibration approach and a statistically defensible estimate total force measurement uncertainty. ILS may be applied in any wind tunnel facility, private or government.

Design of Automotive Structures Using Multi-Model Optimization

2017-01-134203/28/2017

The use of structural optimization in the design of automotive structures is increasingly common. However, it is often challenging to apply these methods simultaneously for different requirements or model configurations. Multi-model optimization (MMO) aims to simplify the iterative design process associated with optimizing multiple parts or configurations with common design variables especially when conflicting requirements exist. In this paper, the use of MMO is demonstrated to evaluate the feasibility of an automotive door concept using an alternative material.

Zagorski, Nicolas, Nelson, Eric, Caliskan, Ari, Li, Allen

Predicting Forming Limit Curve Using a New Ductile Failure Criterion

2017-01-031203/28/2017

Based on findings from micromechanical studies, a Ductile Failure Criterion (DFC) was proposed. The proposed DFC treats localized necking as failure and critical damage as a function of strain path and initial sheet thickness. Under linear strain path assumption, a method to predict Forming Limit Curve (FLC) is derived from this DFC. With the help of predetermined effect functions, the method only needs a calibration at uniaxial tension. The approach was validated by predicting FLCs for sixteen different aluminum and steel sheet metal materials. Comparison shows that the prediction matches quite well with experimental observations in most cases.

Sheng, ZiQiang, Mallick, Pankaj

Modeling of Rivets Using a Cohesive Approach for Crash Simulation of Vehicles in RADIOSS

2017-01-147203/28/2017

Rivets, especially self-piercing rivets (SPR), are a primary joining technology used in aluminum bodied vehicles. SPR are mechanical joining elements used to connect sheets to create a body in white (BiW) structure. To ensure the structural performance of a vehicle in crash load cases it is necessary to describe physical occurring failure modes under overloading conditions in simulations. One failure mode which needs to be predicted precisely by a crash simulation is joint separation. Within crash simulations a detailed analysis of a SPR joint would require a very high computational effort. The conflict between a detailed SPR joint and a macroscopic vehicle model needs to be solved by developing an approach that can handle an accurate macroscopic prediction of SPR behavior with a defined strength level with less computational effort. One approach is using a cohesive material model for a SPR connection. The paper describes cohesive element characteristics and calibration effort

Pasligh, Niels, Schilling, Robert, Bulla, Marian

Generation of Replacement Vehicle Speed Cycles Based on Extensive Customer Data by Means of Markov Models and Threshold Accepting

2017-26-025601/10/2017

The reduction of fuel consumption as well as the rising demands of customers regarding a vehicle’s driving dynamic and the legislator’s continually rising demands are a current issue in vehicle development. Hybrid vehicles offer a possibility to rise to this challenge. Realistic driving cycles are of utmost importance for the calibration of a hybrid vehicle’s operational strategy. Deriving replacement speed cycles from extensive customer data sets seems to be an approach for solving these problems. The contribution at hand describes the derivation of replacement cycles by using stochastic models, probabilistic (weighted) drawings and a combinatorial optimisation. The novelty value is that the characteristic influences of all drivers are being considered in the generation due to the stochastic modelling. The newly developed algorithm extracts frequently reoccurring patterns from the stochastic model and then assembles several generated velocity progressions to one replacement cycle

Liessner, Roman, Dietermann, Ansgar, Bäker, Bernard, Lüpkes, Klaus

Method for Ground-to-Satellite Laser Calibration System

TBMG-2618001/01/2017

NASA’s Langley Research Center has developed the Ground-to-Space Laser Calibration (GSLC) system concept for calibrating Earth observing sensors measuring reflected radiance. GSLC is capable of calibrating sensitivity to polarization, degradation of optics, and response to stray light of spaceborne reflected solar sensors. The concept is based on using an accurate ground-based laser system pointing at and tracking the instrument on orbit during nighttime and clear atmosphere conditions. The GSLC system will be applicable to instrument calibration in both low Earth and geostationary Earth orbits.

Comparative Study of Natural Frequencies of Cubic Fixation Devices for Vibration Testing on Electrodynamic Shakers

2016-36-025010/25/2016

This paper presents a comparative study of different cubic fixation devices used for vibration tests on electrodynamic shakers. The resonance frequencies are obtained experimentally and they are used to calibrate the finite element simulation model. After that, a new design is proposed in order to increase the frequency of its first vibration mode and improve its useful frequency test range.

dos Santos, Marcelo Leandro, Ferreira, André Morais

A Study of Parameter Identification Techniques for Complex Aircraft Systems Models

2016-01-204509/20/2016

Model based design is a standard practice within the aerospace industry. However, the accuracies of these models are only as good as the parameters used to define them and as a result a great deal of effort is spent on model tuning and parameter identification. This process can be very challenging and with the growing complexity and size of these models, manual tuning is often ineffective. Many methods for automated parameter tuning exist. However, for aircraft systems this often leads to large parameter search problems since frequency based identification and direct gradient search schemes are generally not suitable. Furthermore, the cost of experimentation often limits one to sparse data sets which adds an additional layer of difficulty. As a result, these search problems can be highly sensitive to the definition of the model fitness function, the choice of algorithm, and the criteria for convergence. In this paper, the challenge of setting up an effective parameter identification

Deppen, Timothy, Raczkowski, Brian, Kim, Byoung, Walters, Eric, Bodie, Mark, Patnaik, Soumya

Uncertainty Quantification of System Model Parameters with Component Level and Sub-System Level Tests

2016-01-028704/05/2016

An essential step in predicting the output of a complicated system is the calibration of model parameters, but this step cannot be conducted directly if the data at the system-level are not available. In such a situation, a reasonable route is to quantify the system model parameters using tests at lower levels of complexity which share the same model parameters with the system, and propagate the results through the computational model at the system level. For such a multi-level problem, this paper proposes a methodology to quantify the uncertainty in the system-level model parameters by integrating model calibration, model validation and sensitivity analysis at different levels. The proposed approach considers the validity of the models used for parameter estimation at lower levels, as well as the relevance at the lower level to the prediction at the system level. The model validity is evaluated using a model reliability metric, which is extended to handle the uncertainty in model

Li, Chenzhao, Mahadevan, Sankaran

Failure Mode Effects and Fatigue Data Analyses of Welded Vehicle Exhaust Components and Its Applications in Product Validation

2016-01-037404/05/2016

Vehicle exhaust components and systems under fatigue loading often show multiple failure modes, which should be treated, at least theoretically, with rigorous advanced bi-modal and multi-modal statistical theories and approaches. These advanced methods are usually applied to mission-critical engineering applications such as nuclear and aerospace, in which large amounts of test data are often available. In the automotive industry, however, the sample size adopted in the product validation is usually small, thus the bi-modal and multi-modal phenomena cannot be distinguished with certainty. The purpose of this paper is two-fold: (1) a large amount of historical fatigue data of several types of welded exhaust components belonging to several diverse programs are collected and statistically analyzed; the similarities and differences in the data patterns, the standard deviation of the cycles to failure in particular, of the different groups of the data are examined, and (2) with the

Wei, Zhigang, Zhu, George, Gao, Litang, Luo, Limin

Vehicle Longitudinal Control Algorithm Based on Iterative Learning Control

2016-01-165304/05/2016

Vehicle Longitudinal Control (VLC) algorithm is the basis function of automotive Cruise Control system. The main task of VLC is to achieve a longitudinal acceleration tracking controller, performance requirements of which include fast response and high tracking accuracy. At present, many control methods are used to implement vehicle longitudinal control. However, the existing methods are need to be improved because these methods need a high accurate vehicle dynamic model or a number of experiments to calibrate the parameters of controller, which are time consuming and costly. To overcome the difficulties of controller parameters calibration and accurate vehicle dynamic modeling, a vehicle longitudinal control algorithm based on iterative learning control (ILC) is proposed in this paper. The algorithm works based on the information of input and output of the system, so the method does not require a vehicle dynamics model. Due to ILC’s self-learning ability, the controller parameters

Wang, Dazhi, Gao, Zhenhai, Wang, Jun, Hu, Hongyu

A Model-Free Stability Control Design Scheme with Active Steering Actuator Sets

2016-01-165504/05/2016

This paper presents the application of a proposed fuzzy inference system as part of a stability control design scheme implemented with active steering actuator sets. The fuzzy inference system is used to detect the level of overseer/understeer at the high level and a speed-adaptive activation module determines whether an active front steering, active rear steering, or active 4 wheel steering is suited to improve vehicle handling stability. The resulting model-free system is capable of minimizing the amount of model calibration during the vehicle stability control development process as well as improving vehicle performance and stability over a wide range of vehicle and road conditions. A simulation study will be presented that evaluates the proposed scheme and compares the effectiveness of active front steer (AFS) and active rear steer (ARS) in enhancing the vehicle performance. Both time and frequency domain results are presented.

Hirche, Benjamin, Ayalew, Beshah

Thermal Analysis of Heavy Duty Engine Exhaust Manifold Using CFD

2016-01-064804/05/2016

The exhaust manifold bridges the gap between the engine structure and the hot-end after-treatment system, the burned in-cylinder gases are disposed through the manifold. The automotive exhaust manifolds are designed and developed for providing a smooth flow with low/least back pressure and must be able to withstand extreme heating under very high temperatures and cooling under low temperatures. The paper presents a theoretical study aiming to investigate the feasibility of three different CAE approaches and techniques used for the simulation of exhaust manifold fluid flow and the accompanying thermal distribution. The main difficulty emanates from the pulsating nature of fluid flow inside the engine exhaust manifold. To verify the outcome of each solution experimental measurements of the manifold temperatures have been performed. The predicted metal temperature is then used to carry out the thermo-structure durability analysis to evaluate the design of HD diesel engine exhaust manifold

Eroglu, Sinan, Duman, Ipek, Ergenc, Alp, Yanarocak, Rıfat

Calibration Requirements for Testing Coupling-Decoupling Networks

TBMG-2443104/01/2016

Coupling-Decoupling Networks (CDNs) are the unglamorous workhorses that get “hitched up” to an impulse generator in order to perform impulse testing on powered equipment. As such, performance and calibration requirements for CDNs have not been specified to the same level of detail as the impulse generator. This is no longer the case with the Third Edition of IEC 61000-4-5, the international standard for surge immunity testing.

Self-Stabilizing Distributed Clock Synch ronization Protocol for Arbitrary Digraphs

TBMG-23049

10/01/2015

A report describes a self-stabilizing distributed clock synchronization protocol in the absence of faults in the system. It is focused on the distributed clock synchronization of an arbitrary, non-partitioned digraph ranging from fully connected to 1-connected networks of nodes, while allowing for differences in the network elements. The protocol does not rely on assumptions about the initial state of the system, other than the presence of at least one node, and no central clock or a centrally generated signal, pulse, or message is used.

Vector Network Analyzer Calibration for Quasi-Optical Dual Ports

TBMG-2256208/01/2015

It is desirable to measure the electromagnetic properties of devices and materials in the millimeter part of the spectrum. For guided wave-based devices and materials (waveguides, coaxial devices), a vector network analyzer (VNA) is an excellent tool for this purpose since it provides full reflection and transmission characterization at high precision.

Estimation of Algae Growth Stage, Growth Rate, and Lipid Content

TBMG-2256408/01/2015

This invention provides a method using light of different wavelengths to estimate freshwater and marine algae growth stage and algae growth rates as well as lipid content in standard media. Light absorption by the algae is measured for a specified light intensity in each of two or more narrow wavelength ranges, correcting for absorption in the medium without algae. The net light absorption is compared with a reference set of absorption values for the algae at different growth stages.

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