Browse Topic: Cartography

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Research on Automatic Joint Calibration Method of Multi 3D-LIDARs and Inertial Measurement Unit2021-01-00704/6/2021
In the field of automatic driving, the combination of 3D LIDAR and inertial measurement unit (IMU) is a common sensor configuration scheme in laser point-cloud localization, high-precision map making and point-cloud target detection. So it is critical to calibrate LIDAR and IMU accurately. At present, due to the large volume and high cost of 3D LIDAR with high-line-number(Such as 64 lines or 128 lines), the configuration scheme of using multiple low-line-number 3D LIDARs appears in the automatic driving vehicle sensing system. However, the common calibration methods are not suitable for multi 3D LIDARs and IMU parameters calibration on autonomous vehicle, which have the disadvantages of cumbersome implementation and low accuracy. In this paper, a joint calibration test platform composed of dual LIDARs and IMU is assembled, and a method of precise automatic calibration based on GPS/RTK data is proposed. Firstly, the initial parameters of the main 3D LIDAR and IMU are obtained by hand-eye calibration method, and then the motion distortion of the point cloud are removed by using the pose information. After global and local optimization of nearest neighbor error, the conversion parameters from the main LIDAR to IMU are obtained. Then, the remaining LIDARs are calibrated with the main LIDAR by combining coarse registration and fine registration, and finally realize the automatic calibration of external parameters of the entire system. The experimental results show that the proposed method has high calibration accuracy for the system composed of multiple 3D LIDARs and IMU, and the calibration effect is stable.
Zhang, Jinghua, He, Rui, Wu, Jian, Li, Shuai, Chen, Xuesong, Du, Zhiqiang, Chen, Guosheng, Chen, Zhicheng
Mobile Rugged Displays for Situational AwarenessTBMG-3528010/1/2019
With the constant emergence of new display technologies in the consumer sector, it is important for program managers and engineers in the military markets to be aware of how several of these advances can be incorporated into new military programs to achieve maximum benefit. Additionally, as older programs present themselves for technological refreshes, it is imperative to understand the difference in display specifications from previous decades and how updated technology provides avenues for their evolution and continued progress.
Bringing Human-Like Reasoning to Driverless Car NavigationTBMG-347727/1/2019
With the aim of bringing more human-like reasoning to autonomous vehicles, MIT researchers have created a system that uses only simple maps and visual data to enable driverless cars to navigate routes in new, complex environments.
Global Temperature Mapping and Crystallization Analysis of Supercooled Water Droplet Freezing Using Luminescent Imaging Technique2019-01-20096/10/2019
A prominent environmental phenomenon that greatly affects many industries including automotive, aeronautics, energy transmission, etc. is icing. One mechanism by which this occurs and plagues our machines and infrastructures that are exposed to the atmosphere is the icing of supercooled water droplets on a surface - either by impact against a surface or spontaneous nucleation and crystallization of a droplet at rest. The process by which nucleation propagates during the liquid-to-solid phase change and the thermodynamic implications in regards to latent heat generation and transfer are not fully understood on the single droplet scale. An attempt to better resolve these unknowns in both spatial and temporal domains has been made here. Previous efforts have implemented a unique temperature sensing technique utilizing luminescent dyes. A thermally sensitive luminescent paint coated onto the surface of interest allows direct mapping of the heat transfer from the supercooled liquid droplet undergoing freezing to the surface. This technique also provides insight into the nucleation propagation speed along the droplet-substrate interface. This, in conjunction with a high-speed color camera and an intense ultraviolet light source are used to accurately resolve the thermal energy within the freezing droplet in both space and time. Synchronization of the thermal data of the droplet with the measurements of transverse heat transfer through the impact surface allow an estimation of heat generation and loss to the environment - key factors in current modelling and simulation efforts used by researchers and industry to predict ice accretion and to better mitigate it.
Patterson, Wesley Chad, Sakaue, Hirotaka
Driveline NVH Integration of An NA Truck Program2019-01-15596/5/2019
In the current automotive industry, it is common that the driveline subsystem and components are normally from different automotive suppliers for OEMs. In order to ensure proper system integration and successful development of driveline system NVH performances, collaboration efforts between OEMs and suppliers are very demanding and important. In this paper, a process is presented to achieve successfulness in developing and optimizing vehicle integration through effective teamwork between a driveline supplier and a major OEM. The development process includes multiple critical steps. They include target development and roll down, targets being specific and measurable, comprehension of interactions of driveline and vehicle dynamics, accurate definition of sensitivity, proper deployment of modal mapping strategy, which requires open data sharing; and system dynamics and optimization. More specially, the supplier can work with OEM to seek the most cost-effective solutions, through tuning the driveline system dynamics to provide "quiet" frequency zone against vehicle sensitivity, to avoid normally needed costly suspension changes. Two case studies of a pick-up vehicle driveline program integration are used in this paper to illustrate the effectiveness of the development process. The paper also presents the approach used to effectively and efficiently minimize risks for all of the complexities in the program where the complexity is tremendous.
Peng, Ying, Shi, Zhenghong, Folts, Christopher, Kopp, Gregory, Sun, Zhaohui, Sandstrom, Alexander
Going DIGITAL & ELECTRIC @ bauma 201919TOFHP04_054/1/2019
Digitalization and electrification are dominant themes in the equipment and technology being revealed at this year's largest trade show for construction and mining. Digitalization, efficiency and sustainability are three megatrends that off-highway OEMs and suppliers will be touting this month at the triennial bauma trade fair in Munich, when they reveal their technology-laden machines and the intelligent systems that help make them smarter, cleaner and safer. Particular focal areas for many of these companies include electric mobility, telematics and networked construction sites, and increasingly autonomous operation. Some construction machines are already equipped with a range of sensors and communication interfaces that provide comprehensive data on aspects like job performance, location and fuel consumption. While entire fleets can be managed by telematics, many companies struggle with how to implement digital technologies and services.
Gehm, Ryan
Quantum Radio Aids Communications and MappingTBMG-341644/1/2019
GPS signals do not penetrate very deeply or at all in water, soil, or building walls, and therefore can’t be used by submarines or in underground activities such as surveying mines. GPS also may not work well indoors or even outdoors among city skyscrapers. For soldiers, radio signals may be blocked in environments cluttered by rubble or many interfering electromagnetic devices during military or disaster recovery missions.
Structural Integrity of In-Wheel Motors2018-01-18299/10/2018
In-wheel motors offer an optimized solution for novel drivetrain architectures of future electric vehicles that could penetrate into the mainstream automotive industry, moving the wheel actuation where it’s required, directly inside the wheels. Obtainable literature mainly deals with optimization of electromagnetically active parts, however, mechanical design of electromagnetically passive parts that indirectly influence motor performance also requires detailed analysis and extensive validation. To meet the optimal performance requirements (also durable) of an in-wheel traction motor, their mechanical design requires topology optimization of housing elements, thermal mapping, geometrical and dimensional tolerance checks and selection of proper hub bearings, in order to assure consistent electromagnetic behavior stability The following paper uniquely describes the review of loads acting on an in-wheel motor, the workflow of a typical mechanical design process, testing, and validation processes for achieving the required durability of an in-wheel assembly.
Frajnkovic, Matic, Omerovic, Senad, Rozic, Uros, Kern, Jurij, Connes, Raphael, Rener, Kristof, Biček, Matej
Using Multiple Photographs and USGS LiDAR to Improve Photogrammetric Accuracy2018-01-05164/3/2018
The accident reconstruction community relies on photogrammetry for taking measurements from photographs. Camera matching, a close-range photogrammetry method, is a particularly useful tool for locating accident scene evidence after time has passed and the evidence is no longer physically visible. In this method, objects within the accident scene that have remained unchanged are used as a reference for locating evidence that is no longer physically available at the scene such as tire marks, gouge marks, and vehicle points of rest. Roadway lines, edges of pavement, sidewalks, signs, posts, buildings, and other structures are recognizable scene features that if unchanged between the time of accident and time of analysis are beneficial to the photogrammetric process. In instances where these scene features are limited or do not exist, achieving accurate photogrammetric solutions can be challenging. Off-road incidents, snow-covered roadways, rural areas, and unpaved roadways are examples where available scene features may be limited. Other factors like the number of photographs, the specific vantage of the photographs, and occlusion of recognizable features within these photographs can also limit the number of common features available for use in camera matching. In these instances, camera matching solutions can be improved by extending the 3D environment to include objects visible in the distance such as mountains, valleys, and other notable landmarks that are typically outside of the scope of 3D scene mapping. This article demonstrates a method for obtaining and using this elevation data in combination with 3D scene mapping for camera matching photogrammetry. Photogrammetric solutions with limited scene features are compared to photogrammetric solutions based on the same limited scene features with the addition of digital elevation models. Solution accuracies from both scenarios are then individually evaluated to demonstrate improvements through the use of elevation models. In this study, the incorporation of digital elevation modeling at a site with limited scene features demonstrates a 74% improvement for evidence located through camera matching photogrammetry. For further evaluation, the camera match solutions were compared in combined solutions, where information obtained from one camera match was used to inform the next. This was done for both the scenario with digital elevation models and the scenario without. The results demonstrate how the number of available photos can influence the overall accuracy of photogrammetry solutions.
Terpstra, Toby, Dickinson, Jordan, Hashemian, Alireza
Aerospace & Defense Technology: October 201717AERP1010/1/2017
Using Thermal Simulation to Model the Effects of Wind on the Mars Curiosity Rover Quality and Validation of Digital Designs for Aerospace and Defense Scaling LiDAR Optical Payloads from Drones to Miniature UAVs Using Sintered Fiber Metal Composites for Aircraft Acoustic Attenuation GaN Breaks Barriers RF Power Amplifiers Go Wide and High Test System Ensures Flawless Performance of Military RF Devices The Impact of Video Compression on Remote Cardiac Pulse Measurement Using Imaging Photoplethysmography Remote physiological measurement technique leverages digital cameras to recover the blood volume pulse from the human body. Sensitivity Simulation of Compressed Sensing Based Electronic Warfare Receiver Using Orthogonal Matching Pursuit Algorithm Calculate the sensitivity of a CS based EW receiver using two modulation schemes. Initial Validation of Ballistic Shock Accelerometers A Test Operations Procedure (TOP) describing methods and instrumentation used in the initial validation of accelerometers to be used in both Ballistic Shock testing and crew/vehicle survivability Live Fire Test and Evaluation (LFT&E). Custom Data Logger for Real-Time Remote Field Data Collections Compact, energy efficient instruments have the same functionality as a personal computer. Subjective Mapping of Dust-Emission Sources by Using MODIS Imagery Accurate dust-source characterizations are critical for effectively modeling dust storms and their associated hazards. Topology Control in Aerial Multi-Beam Directional Networks Comparing the performance of a centralized algorithm that retains robust connectivity and reduced throughput to a distributed algorithm that offers higher throughput but fewer network nodes.
Network Geolocation TechnologyTBMG-272888/1/2017
A network geolocation technology (NGT) can be used to determine the physical location of a networked Internet user, as well as accurately determine if an Internet user is in fact in the metropolitan service area that the user claims as his/her location. NGT is based on the laws of physics, and operates independent of an IP address lookup or any other pre-existing user network address profiles.
Numerical Simulation and Experimental Validation of an Engine Oil Sump for Improved Noise Characteristics2017-01-18016/5/2017
Powertrain is the major source of noise and vibration in commercial vehicles and has significant contribution on both interior and exterior noise levels. It is vital to reduce the radiated noise from powertrain to meet customer expectations of vehicle comfort and to abide by the legislative noise requirements. Sound intensity mapping technique can identify the critical components of noise radiation from the powertrain. Sound intensity mapping has revealed that oil sump as one of the major contributors for radiated noise from powertrain. Accounting the effect of dynamic coupling of oil on the sump is crucial in predicting its noise radiation performance. Through numerical methods, some amount of work done in predicting the dynamic characteristics of structures filled with fluid. This paper discusses on the capability of numerical approach in predicting the oil sump modal characteristics with fluid-structure interaction and consequent verification with experimental modal test results. Through this study a new oil sump with improved noise characteristics is developed.
Sadasivam, Sivasankaran, Palsule, Aditya, Loganathan, Ekambaram, Inavolu, Nagasuresh, Medisetti, Jaganmohan Rao
An Efficient Input Mobility Mapping Computational Method2017-01-18066/5/2017
The input mobility is a crucial structural parameter regarding vibro-acoustic design of industrial objects. Whatever the frequency range, the vibrational power input into a structure -and consequently the average structural-acoustic response- is governed by the input mobility. When packaging structure-borne noise sources, the knowledge of the input mobility at the source connection points is mandatory for noise control. The input mobility is classically computed at the required points as a specific Frequency Response Function (FRF). During an industrial design process, the choice of connection points requires an a priori knowledge of the input mobility at every possible location of the studied structure-borne source, i.e. a mapping of the input mobility. The classical FRF computation at every Degree Of Freedom (DOF) of the considered structure would lead to consider millions of load cases which is beyond current computational limits. This paper presents how to efficiently compute the full map of band-averaged input mobility over a Finite Elements mesh. The proposed method is based upon a modal decomposition of the structural response and analytical frequency integration; consequently, it only requires the modal basis as it is currently computed. The frequency band average allows optimizing the storage size. Since the input mobility is a real quantity, associated to each DOF of a structure, modal display tools can be used without modification. Thus, a meaningful map is provided, allowing efficient structural dynamics analysis over a broad frequency range.
Gagliardini, Laurent
Video Analysis of Motorcycle and Rider Dynamics During High-Side Falls2017-01-14133/28/2017
This paper investigates the dynamics of four motorcycle crashes that occurred on or near a curve (Edwards Corner) on a section of the Mulholland Highway called “The Snake.” This section of highway is located in the Santa Monica Mountains of California. All four accidents were captured on video and they each involved a high-side fall of the motorcycle and rider. This article reports a technical description and analysis of these videos in which the motion of the motorcycles and riders is quantified. To aid in the analysis, the authors mapped Edwards Corner using both a Sokkia total station and a Faro laser scanner. This mapping data enabled analysis of the videos to determine the initial speed of the motorcycles, to identify where in the curve particular rider actions occurred, to quantify the motion of the motorcycles and riders, and to characterize the roadway radius and superelevation throughout the curve. For each crash video, this paper reports quantitative data from the crash along with a qualitative description of the rider’s actions.
Rose, Nathan A., Carter, Neal, Pentecost, David, Hashemian, Alireza
Study of Active Steering Algorithm Logic in EPS Systems by Detecting Vehicle Driving Conditions2017-01-14813/28/2017
Conventional EPS (Electric Power Steering) systems are operated by one type of steering tuning map set by steering test drivers before being released to customers. That is, the steering efforts can't change in many different driving conditions such as road conditions (low mu, high mu and unpaved roads) or some specific driving conditions (sudden stopping, entering into EPS failure modes and full accelerating). Those conditions can't give drivers consistent steering efforts. This paper approached the new concept technology detecting those conditions by using vehicle and EPS sensors such as tire wheel speeds, vehicle speed, steering angle, steering torque, steering speed and so on. After detecting those conditions and judging what the best steering efforts for safe vehicle driving are, EPS systems automatically can be changed with the steering friction level and selection of steering optimized mapping on several conditions.
Lee, Kyung-bok, Lee, Sanghyuk, Kim, Namyoung, Kim, Bong Soo, Chi, Tae soo, Kim, Do young
Electric Drive Transient Behavior Modeling: Comparison of Steady State Map Based Offline Simulation and Hardware-in-the-Loop Testing2017-01-16053/28/2017
Electric drives, whether in battery electric vehicles (BEVs) or various other applications, are an important part of modern transportation. Traditionally, physics-based models based on steady-state mapping of electric drives have been used to evaluate their behavior under transient conditions. Hardware-in-the-Loop (HIL) testing seeks to provide a more accurate representation of a component’s behavior under transient load conditions that are more representative of real world conditions it will operate under, without requiring a full vehicle installation. Oak Ridge National Laboratory (ORNL) developed such a HIL test platform capable of subjecting electric drives to both conventional steady-state test procedures as well as transient experiments such as vehicle drive cycles. This facility was used to compare the behavior of an electric drive installed in a BEV with the two methods: offline simulation built from the experimental steady state efficiency map, and HIL experimentation of the same electric drive simulating the same BEV. The aim of this study is to evaluate the accuracy of steady state map based simulation against experimental HIL results in the case of an electric drive. This paper first outlines HIL test procedures as well as the key aspects of utilizing steady-state maps to develop a model of the drive. Then both quantitative and qualitative differences in the experimental results obtained from the two processes are presented. Differences in specific transient behaviors between the two methods are discussed. Although both methods agree well in most transient situations, direct comparison of the offline simulation against the HIL results demonstrates that transient behaviors are not captured entirely by simulation alone.
Chambon, Paul, Deter, Dean, Smith, David, Bauman, Grant
Aircraft Configured for Flight in an Atmosphere Having Low DensityTBMG-264993/1/2017
NASA Langley Research Center researchers have developed an airplane capable of being stowed in a confined volume and deployed in a high-altitude environment for extended-duration flight operations in a low-density atmosphere. Engineers, scientists, and end users can take advantage of this innovation that provides previously unattainable high-altitude flight operations. The airplane is delivered to a specified altitude folded in a container or rocket. Once released, the plane unfolds and executes a pull-up maneuver to stabilize altitude. In addition, the current suite of onboard scientific instrumentation includes magnetometers, a mass spectrometer, and variable-use cameras. NASA is seeking market insights on commercialization of the new airplane design, and welcomes interest from potential producers, users, and licensees.
Detection and Characterization of Recurring Slope LineaeTBMG-2605012/1/2016
Recurring Slope Lineae (RSL) are low-albedo features that appear and disappear seasonally on Martian slopes. They provide distinct surface markers that are thought to result from the activity of subsurface water. Reliable characterizations of RSL activity are needed to test this hypothesis. RSL are of high scientific interest, and could inform future mission planning priorities beyond sample return.
Method for Analytical Calculation of Harmonic Content of Auto-Transformer Rectifier Units2016-01-20599/20/2016
Auto transformer rectifier units (ATRUs) are commonly used in aircraft applications such as electric actuation for harmonic mitigation due to their high reliability and relative low cost. However, those components and the magnetic filter components associated to it are the major contributors to the overall size and weight of the system. Optimization of the magnetic components is essential in order to minimize weight and size, which are major market drivers in aerospace industry today. This requires knowledge of the harmonic content of the current. This can be obtained by simulation, but the process is slow. In order to enable fast and efficient design space exploration of optimal solutions, an algebraic calculation process is proposed in this paper for multi-pulse ATRUs (e.g. 12-pulse and 18-pulse rectifiers), starting from existing solution proposed for 6 pulse rectifier in the literature. The method consists of mapping AC and DC sides of a balanced 6N-Pulse system into the sum of equivalent 6-Pulse systems. This problem can then be solved with available methods, and then the AC and DC currents are transformed back into the 6N-Pulse problem. The method is fast and accurate, and allows calculating both magnitudes and phase angles of AC and DC currents, thus enabling reconstruction of the current waveform.
Loewenherz, Rolf, Valdivia-Guerrero, Virgilio, Diaz Lopez, Daniel, Parkin, Joshua
Methods of Real-Time Image Enhancement of Flash LIDAR Data and Navigating a Vehicle Using Flash LIDAR DataTBMG-251408/1/2016
NASA’s Langley Research Center has developed 3D imaging technologies (Flash LIDAR) for real-time terrain mapping and synthetic vision-based navigation. To take advantage of the information inherent in a sequence of 3D images acquired at video rates, NASA Langley has also developed an embedded image-processing algorithm that can simultaneously correct, enhance, and derive relative motion by processing this image sequence into a high-resolution 3D synthetic image. Traditional scanning LIDAR techniques generate an image frame by raster scanning an image one laser pulse per pixel at a time, whereas Flash LIDAR acquires an image much like an ordinary camera, generating an image using a single laser pulse. The benefits of the Flash LIDAR technique and the corresponding image-to-image processing enable autonomous vision-based guidance and control for robotic systems. The current algorithm offers up to eight times image resolution enhancement, as well as a 6-degree-of-freedom state vector of motion in the image frame.
Numerical Study of Internal Combustion Engine using OpenFOAM®2016-01-13464/5/2016
We developed the numerical simulation tool by using OpenFOAM® and in-house simulation codes for Gasoline Direct Injection (GDI) engine in order to carry out the precise investigation of the throughout process from the internal nozzle flow to the fuel/air mixture in engines. For the piston/valve motions, a mapping approach is employed and implemented in this study. In the meantime, the spray atomization including the liquid-columnbreakup region and the secondary-breakup region are simulated by combining the different numerical approaches applied to each region. By connecting the result of liquid-column-breakup simulation to the secondary-breakup simulation, the regions which have different physical phenomena with different length scales are seamlessly jointed; i.e., the velocity and position of droplets predicted by the liquid-column-breakup simulation is used in the secondary breakup simulation so that the initial velocity and position of droplets are transferred. The simulation technique above is verified as the follows. Firstly, the air-flow simulation for engines is compared to the experiments. The simulation results agree will with the experiment in terms of the velocity profile and the turbulence velocity profile. Secondary, the spray shape and the penetration are quantitatively compared to the experiments. It is observed that the simulation results agree well with the experiment. Finally, the spray simulation is implemented in engines with piston/valve motions. The fuel/air mixture during the aspiration process can be predicted.
Hosaka, Tomoyuki, Sugii, Taisuke, Ishii, Eiji, Oryoji, Kazuhiro, Sukegawa, Yoshihiro
Simulation of Atmospheric Turbulence for Wind-Tunnel Tests on Full-Scale Light-Duty Vehicles2016-01-15834/5/2016
During the past year, a novel turbulence generation system has been commissioned in the National Research Council (NRC) 9 m Wind Tunnel. This system, called the Road Turbulence System was developed to simulate with high fidelity the turbulence experienced by a heavy duty vehicle on the road at a geometrical scale of 30%. The turbulence characteristics that it can simulate were defined based on an extensive field measurement campaign on Canadian roads for various conditions (heavy and light traffic, topography, exposure) at heights above ground relevant not only for heavy duty vehicles but also for light duty vehicles. In an effort to improve continually the simulation of the road conditions for aerodynamic evaluations of ground vehicles, a study was carried out at NRC to define the applicability of the Road Turbulence System to aerodynamic testing of full-scale light duty vehicles. Using the on-road measurements as a guide, it was concluded that the RTS appears to provide a more representative simulation of on-road conditions for wind-tunnel testing, compared with other passive methods such as with rope nets, spires, large turbulence grids or also with active turbulent generation techniques. Although some differences from the target turbulence conditions were found, all spectra measured behind the RTS were found to be within the range of turbulence energy measured during the on-road campaign. As such, the RTS was subsequently used for measurements of two full-scale light-duty vehicles (a large car and a standard sport-utility vehicle) during a test campaign examining the influence of active drag-reduction technologies. Comparison of these data to the equivalent smooth-flow measurements showed different influences of turbulence on the drag behaviour for each of the two vehicles.
McAuliffe, Brian R., Wall, Alanna, Larose, Guy
Determining Position and Speed through Pixel Tracking and 2D Coordinate Transformation in a 3D Environment2016-01-14784/5/2016
This paper presents a methodology for determining the position and speed of objects such as vehicles, pedestrians, or cyclists that are visible in video footage captured with only one camera. Objects are tracked in the video footage based on the change in pixels that represent the object moving. Commercially available programs such as PFTracktm and Adobe After Effectstm contain automated pixel tracking features that record the position of the pixel, over time, two dimensionally using the video’s resolution as a Cartesian coordinate system. The coordinate data of the pixel over time can then be transformed to three dimensional data by ray tracing the pixel coordinates onto three dimensional geometry of the same scene that is visible in the video footage background. This paper explains the automated process of first tracking pixels in the video footage, and then remapping the 2D coordinates onto three dimensional geometry using previously published projection mapping and photogrammetry techniques. The results of this process are then compared to VBOX recordings of the objects seen in the video to evaluate the accuracy of the method. Some beneficial aspects of this process include the time reduced in tracking the object, since it is automated, and also that the shape and size of the object being tracked does not need to be known since it is a pixel being tracked, rather than the geometry of the object itself.
Neale, William T., Hessel, David, Koch, Daniel
Fabrication of an Integrated Photonic Waveguide Joint in Micromachined SiliconTBMG-242554/1/2016
High-aspect-ratio silicon structures are necessary components in many MEMS (microelectromechanical systems). Aspect ratio is defined as the ratio of the height of the structure to its lateral width. The structures are typically fabricated through bulk micromachining steps such as deep reactive ion etching. In some cases, multiple levels of high-aspect-ratio structures are required. For instance, one may want to etch completely through a silicon wafer to thermally isolate a bolometer or provide waveguide coupling to an antenna defined on an insulating membrane, and at the same time have integrated high-topology structures required for microwave coupling or filtering. Definition of the structures typically uses photolithographic technology. But for high-aspect-ratio structures, spin cast resist becomes difficult to incorporate due to the non-uniform thickness of the resist around tall structures. One can cast very thick layers of photoresist, but this limits the minimum feature size, and additionally, very thick layers of photoresist are difficult to work with due to solvent release and moisture that can cause the resist to crack or swell. For electromagnetic reasons, the structures would preferably be made from conductive material such as metal or degeneratively doped silicon. The objective of this work was to incorporate multiple levels of conductive high-aspectratio structures with standard micromachining processes.
A 16-Beam, Non-Scanning, Swath-Mapping Laser Altimeter InstrumentTBMG-2327911/1/2015
The purpose of this work was to develop and demonstrate technologies for a next-generation, efficient, swath-mapping space laser altimeter. The Lidar Surface Topography (LIST) mission concept allows simultaneous measurements of 5-meter-spatial-resolution topography and vegetation vertical structure with decimeter vertical precision in an elevationimaging swath several kilometers wide from a 400-km-altitude Earth orbit. To advance and demonstrate needed technologies for the LIST mission, the Airborne LIST Simulator (ALISTS) pathfinder instrument was developed. ALISTS is a micropulse, single photon-sensitive waveform recording system based on a new and highly efficient laser measurement approach utilizing emerging laser transmitter and detector technologies.
NASA Vision Workbench (VWB) v3TBMG-223937/1/2015
VWB is a modular, extensible computer vision framework that supports tasks including automated science and engineering analysis, large satellite image processing, and 2D/3D environment reconstruction. The framework provides a rapid C++ development environment as well as a flexible, multi-platform system to deploy computer vision applications. The module interface allows new capabilities to be rapidly integrated, and a dataflow architecture allows image processing pipelines to be quickly developed and reconfigured.
Effective Placement of Noise Control Acoustic Material in a Vehicle for a Typical Front of Dash Application by Identifying Critical Location Area through Effective Sound Intensity Mapping Method2015-01-22516/15/2015
NVH in automobile has been very demanding over the years and is considered to be one of the key focus areas for customer satisfaction identified by the automobile companies. A lot of work has been done towards optimizing noise treatment materials and its effective placement to suit performance, weight and cost. This paper outlines a unique method to optimize the coverage of the NCT around the FOD area by conducting an effective sound intensity mapping around the FOD area at the cabin side with the help of a two microphone based sound intensity probe.
Varghese, Alex, Palled, Satish
Active Control of Structure-Borne Road Noise Based on the Separation of Front and Rear Structural Road Noise Related Dynamics2015-01-22226/15/2015
Axle forces from tire-road interaction can excite different structural resonances of the vehicle hence a high number of sensors is required for observing and separating all the vibrations dynamics that are coherent with the cabin noise. Feed-forward road noise control strategies adopted so far rely mainly on capturing these dynamics and thus the number of sensors constitutes one major limitation of this approach. Therefore there is a necessity for reducing the number of sensors without degrading the performance of an ANC system. In the past coherence function analysis has been found to be a useful tool for optimizing the sensor location. In this case coherence function mapping was performed between an array of vibration sensors and the headrest microphones in order to identify the locations on the structure that are highly correlated with road noise bands in the compartment. A vehicle with an advanced suspension system was used for applying the method and defining some locations as reference signals for feed-forward active road noise control. Three different real-time control experiments were performed with structure-borne road noise simulated by applying broad band random forces to tires through shaker transducers. A single reference feed-forward adaptive controller evaluated the signals from each sensor location with simulated road noise excitation applied to: front wheels only, rear wheels only and whole vehicle. This way it is demonstrated that the control can be focused at specific road noise bands with a low number of sensors.
Zafeiropoulos, Nikos, Ballatore, Marco, Moorhouse, Andy, Mackay, Andy
Unsteady Thermal Simulations of Wing Ice Protection Systems Integrated in Metallic or Composite Structures2015-01-20936/15/2015
Advanced sizing of the thermal wing ice protection system (WIPS) requires an improved and a robust manner to simulate the system operation in unsteady phases and particularly in de-icing operations. A two dimensional numerical tool has been developed to enable the simulation of unsteady anti-icing and de-icing operations. For example, the WIPS may be activated with delay after entering into the icing conditions. In this case, ice starts to accrete on the leading edge before the WIPS heats up the skin. Another example is the ground activation of the WIPS for several seconds to check its functionality: low external cooling may cause high thermal constraints that must be estimated with accuracy to avoid adverse effects on the structure. Thermal de-icing WIPS integrated in composite structures intrinsically have unsteady behaviors; the tool enables the computation of the skin temperature evolution with the time. This provides an insightful indication on the de-icing performance of the WIPS and allows adjusting the design of the WIPS to optimize the system energy consumption. Calibrations through IWT were conducted to ensure the accuracy of the global thermal prediction. Regarding structural sizing, the modelling provides temperature distribution mapping of the structure. This is advantageous for assessing the impact of thermal ageing of metallic structures or for validating the used materials of composite structures. Therefore the weight can be optimized.
Henno, Maxime
Ice Shape Mapping by Means of 4D-Scans2015-01-21516/15/2015
When studying ice accretion processes experimentally it is desirable to document the generated ice shapes as accurately as possible. The obtained set of data can then be used for aerodynamic studies, the improvement of icing test facilities, the development of design criteria, the validation of ice accretion simulation tools as well as other applications. In the past, various ice shape documentation methods have been established including photography, cross-sectional tracing, molding and casting as well as 3D-scanning. This work introduces a new ice shape documentation technique based on active 3D-scanning in combination with fluorescent dyes and an optimized set of optical filters. The new approach allows recording the time-resolved three dimensional growth of an arbitrary ice shape. Based on this concept a so-called 4D-scanning system is developed, which allows a detailed evaluation of icing experiments and hence a better understanding of the ice accretion process itself. The scanning system has been successfully implemented and tested in two icing wind tunnels of completely different size, namely FH JOANNEUM's small scaled icing wind tunnel and Rail Tec Arsenal's large icing wind tunnel.
Puffing, Reinhard F.A., Hassler, Wolfgang, Tramposch, Andreas, Peciar, Marian
Neo-Geography Toolkit (NGT) v2TBMG-221766/1/2015
The Neo-Geography Toolkit (NGT) is a collection of open-source software tools for the automated processing of geospatial data, including images and maps. It can process raw raster data from remote sensing instruments and transform it into useful cartographic products such as visible image base maps, topographic models, etc. It can also perform data processing on extremely large geospatial data sets (up to several tens of terabytes) via parallel processing pipelines. Finally, it can transform raw metadata, vector data, and geo-tagged datasets into standard Neo-Geography data formats such as KML.
A Discussion on Vehicle AC System TXV Optimization2015-01-03644/14/2015
This paper presents the way to optimize vehicle AC system TXV to meet the various AC system requirements. It discusses vehicle AC system TXV sizing and selection process. In today's automotive industry, sizing and selecting the TXV is more complicated than before as various new components are introduced such as external control compressor, internal control compressors and internal heat exchanger etc. These components complicated the system interaction among the components. Thus it requires mapping TXV characteristic to meet the system demand. Sizing TXV capacity, it must start with the vehicle heat load requirement. The type of TXV (i.e. cross charge or parallel charge head) is determined by the system configuration such as compressor, evaporator, and condenser type and with or without internal heat exchanger, etc. To optimize TXV in the system involves in evaluating TXV characteristic and cooling capacity in the various AC operating conditions. The criteria for the evaluation can determine how the selected TXV behaviors in the real world. The paper also discusses how the TXV manufacture 4-Q diagram can be utilized in optimizing TXV in the system. The case study shows how the presented TXV sizing and selection process works. The recommended TXV evaluation criteria are also discussed in the paper.
Zheng, Yinhua
Recent Developments in X-ray Diagnostics for Cavitation2015-01-09184/14/2015
Cavitation plays an important role in fuel injection systems. It alters the nozzle's internal flow structure and discharge coefficient, and also contributes to injector wear. Quantitatively measuring and mapping the cavitation vapor distribution in a fuel injector is difficult, as cavitation occurs on very short time and length scales. Optical measurements of transparent model nozzles can indicate the morphology of large-scale cavitation, but are generally limited by the substantial amount of scattering that occurs between vapor and liquid phases. These limitations can be overcome with x-ray diagnostics, as x-rays refract, scatter and absorb much more weakly from phase interfaces. Here, we present an overview of some recent developments in quantitative x-ray diagnostics for cavitating flows. Measurements were conducted at the Advanced Photon Source at Argonne National Laboratory, using a submerged plastic test nozzle. X-ray radiography provides quantitative line-of-sight density measurements of cavitation void fraction by measuring relative changes in absorption, with a relatively constant uncertainty of 2% of a typical peak value. Single point measurements are built up into a vapor fraction distribution by raster-scanning the nozzle through the fixed beam. X-ray fluorescence, a novel alternative diagnostic, can provide a similar quantitative point measurement, but measures the emission of fluorescent x-rays from an excited tracer in the fuel rather than the directly transmitted beam. An uncertainty of 1.1% of the projected void fraction is achieved, giving a more precise measurement near the nozzle wall. X-ray phase contrast imaging provides a temporally and spatially resolved view of the flow due to absorption and diffraction, revealing small-scale dynamic behaviors that are difficult to observe in point-based measurements.
Duke, Daniel, Swantek, Andrew, Kastengren, Alan, Fezzaa, Kamel, Powell, Christopher
Electronic Warfare TechnologyTBMG-218814/1/2015
Military electronic warfare (EW) systems including navigation, radar guidance, terrain mapping and others, require lightweight compact components, with radio frequency (RF) output power levels to several kilowatts typically needed to meet system requirements. As GaN transistor technology advances in frequency and power output, solid state power amplifiers (SSPAs) have begun replacing traveling wave tubes (TWTs) at frequencies up to 6 GHz. The utilization of this technology results in a lower cost and greater efficiency over the life of a product.
Instant Mileage Assistance (IMA) in a Geared Two Wheeler2014-32-002811/11/2014
The Instant Mileage Assistance (IMA), as the name indicates, is a system to guide the vehicle users to realize maximum fuel economy (mileage). This system is targeted to provide users with instantaneous mileage indication depending on the current driving pattern, correct gear operating zone (in case of a geared vehicle) through gear up/down shift assist indication and the accurate distance the vehicle can travel before the fuel tank is empty, thereby assisting the user in harnessing maximum fuel economy the vehicle can deliver and also safely reach the next refilling station. The instantaneous mileage is calculated by mapping the distance travelled by the vehicle and the respective amount of fuel consumed, during a particular period of time, and is displayed using an instrument cluster. When the fuel level in the tank reaches a known threshold, the distance to empty is in turn calculated from the instantaneous mileage value hence providing a more accurate and realistic indication to the user. The gear shift up/down prompt is a unique feature which suggests the user to shift gears in order to operate the engine in best fuel economy delivery zone.
Manikandan, T, Ameer, S Sarmadh, Sivakumar, A, Kumar, Davinder, Venkatesan, R, Kumar, VenkataKalyana
Evaluation of Camshaft Control Strategies for a GDI Engine using a Multidisciplinary Optimisation Framework2014-01-258110/13/2014
This paper presents a calibration optimization study for a Gasoline Direct Injection engine based on a multidisciplinary design optimization (MDO) framework. The paper presents the experimental framework used for the GDI engine mapping, followed by an analysis of the calibration optimization problem. The merits of the MDO approach to calibration optimization are discussed in comparison with a conventional two-stage approach based on local trade-off optimization analysis, focused on a representative emissions drive cycle (NEDC) and limited part load engine operation. The benefits from using the MDO optimisation framework are further illustrated with a study of relative effectiveness of different camshaft timing control strategies (twin independent Versus fixed timing, exhaust only, inlet only and fixed overlap / dual equal) for the reference GDI engine based on the part load test data. The main conclusion is that the MDO structure offers an effective framework for the GDI steady state calibration optimization analysis.
Kianifar, Mohammed Reza, Campean, Felician, Richardson, David
Military Technologies for Improving Efficiency & Safety in Off-Road Commercial Vehicles2014-01-23989/30/2014
Off-road commercial vehicles many times have to work at remote areas in poor working conditions like reduced visibility due to fog, snow, inadequate ambient lighting, dust etc. They may not have any access to emergency facilities in such places. Challenging geographical terrains and adverse weather conditions makes the situation worse. The combination of both can further degrade working conditions. The operator may need to either work or guide his vehicle through tight places or in hilly areas having such conditions. That imposes many challenges to operator in terms of efficiency & safety of both operator & vehicle. In an effort to increase productivity and efficiency operator may miss to look at safety aspects consequently, leading to accidents that can incur heavy losses due to damages to vehicle further delaying the work. It can even lead to a life threatening emergency in some cases. On the other hand, decrease in efficiency results in increased cost of operation due to unnecessary wastage of fuel & delays in getting the work done. Defense sector, due to their nature of work & high risk; have been investing a lot to invent technologies that can enable soldiers to work in adverse conditions reducing the potential hazards to their soldiers & war machines. Due to this, defense sector already has upper hand in developing such technologies for their forces to help them work in adverse conditions without compromising performance & efficiency and can save lives. These highly advanced technologies are helping modern militaries in applications such as performing covert operations, reconnaissance without getting detected, covert target illumination & detection etc. thereby reducing casualties and losses to war machines. Some of these technologies can find their applications in commercial off-road vehicles used in agriculture, construction, forestry & mining with same intent. Once closely guarded these technologies are now commercially available. As these technologies are made to order and are not being mass produced; at present, their cost is relatively higher to the technologies being used in off-road vehicles. But, once they are introduced in vehicles, with advent of mass production the cost will go down. Radar is one such example of technology which was once used in combat applications and was very costly, but now being widely used in vehicles for various applications. The intent of this paper is to identify some of these technologies and their potential applications in off-road commercial vehicles.
Pawar, Sanket
Friction Coefficient Mapping during Brake Interventions2014-01-24969/28/2014
This paper comprises obtaining friction coefficient (μ) measure by extracting surface and texture information using sensors during brake interventions. A primary estimate of friction coefficient has been obtained using wheel and vehicle signals. The estimates have been compared and combined to obtain a more accurate measure of friction coefficient. Finally, a suitable interpolation technique is used to obtain a μ-grid around the vehicle. The grid is graphically realized with the aid of visualization techniques using vehicle traces. This type of surface characterization usually enables brake distance optimization and effective countermeasures pertaining to a standard ESP system.
Venkata Padmanabhan, Adarsh, Ravichandran, Hariram, Pappala, Lokendra Pavan Kumar, Shenoy, Shreyas
Structures Perspective for Strength and Fatigue Prognosis in CompositesF-0070-2014-96365/20/2014
Recent advances in understanding deformation and failure mechanisms of polymer-matrix composites used in rotor structures enable accurate and efficient measurement of material stiffness, strength, and fatigue characteristics based on testing small unidirectional laminate specimens. Successful failure predictions increased our confidence in the development of virtual test methods replacing some of the standard tests of multi-directional laminated composite materials with three-dimensional models accurately predicting deformation, damage topography, strength, and cycles to failure. However, the remaining key questions are related to the ability of transitioning the material scale virtual test information to larger composite structures. This work presents results of the feasibility assessment targeting the scaling of knowledge and methods acquired at the material scale, to larger structural elements.
Nikishkov, Yuri, Seon, Guillaume, Makeev, Andrew
Study on Optimization for LNT+SCR System of Diesel Vehicle to Comply with the LEV3 Regulations2014-01-15294/1/2014
This paper describes how to meet LEVII ULEV70 emission standards and minimize fuel consumption with the combined NOx after-treatment (LNT+SCR) system for diesel vehicles. Through analysis of LNT's functionality and characteristics in a LNT+SCR combined after-treatment system, allowed a new control strategy to be established, different from the existing LNT-only system. In the 200°C or higher condition where SCR can provide the most stable NOx conversion efficiency, rich regeneration of LNT was optimized to minimize LNT deterioration and fuel consumption. Optimized mapping between rapid heat up strategy and raw NOx reduction maximized LNT's NOx conversion efficiency during the intervals when it is not possible for SCR to purify NOx This study used bench aged catalysts which were equivalent to 150K full useful life. During the Highway (HFET) driving cycle when the SCR conversion rate is generally high, fuel economy was improved by minimization DeNOx in LNT and improvement of the engine combustion efficiency. In conclusion, this study provided a solution to optimize a combined after-treatment system, leading to test results that met EPA 150K Emissions regulations. This study also found that an LNT+SCR after-treatment system which can meet sea level EPA FTP-75 emissions regulations is able to also meet high-altitude and highway emissions regulations.
Jeon, Jongik, Seo, Hyongman, Lee, Kangwon, Kwon, Soonhyung, Bae, Kisong
Statistical Analysis of Impacts of Surface Topography on Brake Squeal in Disc-Pad System2014-01-00274/1/2014
A disc-pad system is established to study impacts of surface topography on brake squeal from the perspective of statistical analysis. Firstly, surface topographies of brake disc and pad are precisely measured on the scale of micron and are statistically analyzed with a three-dimensional evaluation system. Secondly, the finite element model of brake disc and pad without surface topographies is created and verified through component free modal tests. Thereby the valid brake squeal model for complex modal analysis is built with ABAQUS. An effective method is developed to apply interface topographies to the smooth contact model, which consequently establishes sixty brake squeal models with topographies. Thirdly, impacts of surface topography on brake squeal are studied through comparison and statistical analysis of prediction results with and without topographies. The analysis manifest that topography amplitudes and evaluation index deviations of brake pad far exceed those of the disc, indicating the surface of brake pad is relatively much rougher. Moreover, squeal prediction results confirm that surface topographies can both cause contact pressure variation and affect the randomness of brake squeal characteristics, namely, numbers and values of squeal frequencies. Additionally, contact interface topographies can cause system modal coupling states to change, which further affects squeal tendency and uncertainty. Meanwhile, statistical characteristics and variations of surface topographies demonstrate close correlation with those of brake squeals. Hence the consideration of surface topographies can effectively improve squeal prediction precision, and stochastic characteristics of brake squeal during tests can be well justified by the time-varying surface topography.
Huang, Meng
LES of Flow Processes in an SI Engine Using Two Approaches: OpenFoam and PsiPhi2014-01-11214/1/2014
In this study two different simulation approaches to large eddy simulation of spark-ignition engines are compared. Additionally, some of the simulation results are compared to experimentally obtained in-cylinder velocity measurements. The first approach applies unstructured grids with an automated meshing procedure, using OpenFoam and Lib-ICE with a mapping approach. The second approach applies the efficient in-house code PsiPhi on equidistant, Cartesian grids, representing walls by immersed boundaries, where the moving piston and valves are described as topologically connected groups of Lagrangian particles. In the experiments, two-dimensional two-component particle image velocimetry is applied in the central tumble plane of the cylinder of an optically accessible engine. Good agreement between numerical results and experiment are obtained by both approaches.
Nguyen, Thuong, Janas, Peter, Lucchini, Tommaso, D'Errico, Gianluca, Kaiser, Sebastian, Kempf, Andreas
Integration of an E85 Reforming System into a Vehicle-Ready Package and Project Results2014-01-11914/1/2014
Ethanol can be converted into a 1:1:1 mixture of H2, CO, and CH4 at 300°C using a copper-nickel catalyst, a process known as “low-temperature ethanol reforming.” The hydrogen content of this mixture enables an engine to operate lean or with high levels of EGR, improving fuel economy and emissions. An onboard ethanol reformer- a catalyst module providing heat exchange with exhaust-was recently reported and shown to exhibit stable high conversion of ethanol driven by exhaust heat. This paper describes the successful integration and operation of a Ford 3.5L 3 TiVCT flex-fuel engine with a compact reformer and auxiliary hardware, fueled by E85. The system constitutes an integrated power system suitable for vehicle integration. The engine was operated on a mixture of E85 and reformate using a stoichiometric air-fuel ratio with internal EGR at a 12:1 compression ratio. At the worldwide mapping point, 1500 rpm/2.6 bar BMEP, use of 25% reformate in the fuel enabled stable engine operation with extreme valve overlap (50° EVO /40° IVC) and delivered efficiency improvement of about 10% over E85 alone. At idle (600 rpm/ 0.7 bar BMEP) using 40% reformate in E85 with 30° EVO provided a 12.3% efficiency improvement. A lightweight “shoebox” reformer design provided stable operation while producing only minor exhaust backpressure. The system also included an exhaust diverter valve to control reformer temperature and a buffer tank with automated drain to provide a reserve of dry reformate for cold start and engine transients.
Fowler, John, Morgenstern, David, Sall, Erik, Veinbergs, Martin E.
Combustion and Emissions Performance Analysis of Conventional and Future Fuels using Advanced CAE2013-01-267310/14/2013
In recent years, there has been rapid progress in characterizing the detailed chemical kinetics associated with the oxidation of liquid hydrocarbons and their blends. However adding these fuel models to the industrial engineer's toolkit has proven a major challenge due to issues associated with high CPU cost and the poor suitability of many of the most promising and well known fuel models to IC engine applications. This paper demonstrates the state-of-the-art in the analysis and modelling of current and future transportation fuels or fuel blends for internal combustion engine applications. First-of-all, a benchmarking of eleven representative fuel models (39 to 1034 species in size) is carried out at engine/engine-like operating conditions by adopting the standard Research Octane and Cetane Number test data for comparison. Next, methods to construct a fuel model for a commercial fuel are outlined using a simple, yet robust surrogate mapping technique. Finally, this method is used together with an extensively validated IC engine simulator (based on PDF-based methods - characterizing all key engine sub-processes fuel injection, turbulence, heat transfer etc.), to analyze the performance of multiple fuels and fuel blends (six commercial gasoline and diesel fuels and two standard bio-diesel/diesel blends) in two CIDI engines.
Smallbone, Andrew, Bhave, Amit, Morgan, Neal, Mühlbauer, Wolfgang, Lorenz, Sebastian, Brueggemann, Dieter
Experimental Investigations of the Topography Dynamics in Brake Pads2013-01-20279/30/2013
For more than a decade, investigations of the surface topography and chemical behavior of the boundary layer have been performed. This is of great importance for the understanding of friction, as it provides valuable insights into the dynamic processes that influence the brake pad's performance. The adaption of the boundary layer to a new load condition is of particular interest because it allows for the identification and description of mechanisms that influence macroscopically-observable effects, and quantities such as the coefficient of friction. It is possible to determine time constants that describe this process of adaption. The investigations discussed in this paper combine tribometer tests and optical investigations at the same time. Therefore, the measured coefficient of friction can be related to the observed surface topography of the brake pad. Using a scaled laboratory-tribometer eliminates the influence of the complete brake system and allows for a highly flexible design of test procedures. This is necessary for an insightful study of the adaptation processes of the boundary layer. The generated information can be used for a macroscopic description of the friction process using dynamic friction laws with a suitable parameterization.
Ostermeyer, Georg Peter, Wilkening, Lars
An Integrated Software Environment for UAV Missions Support2013-01-21899/17/2013
This paper describes the design and development of a virtual environment conceived to support flight operations of an Unmanned Air Vehicle (UAV) used for wind mapping in the proximity of existing or planned wind farms. The virtual environment can be used in pre-flight briefings aiming to define a trajectory from a list of waypoints, to change and eventually re-plan the mission in case of intersection with no fly zones, to simulate the mission, and to preview images/videos taken from the UAV on-board cameras. During flight, the tool can be used to compute the wind speed along the trajectory by analyzing the data streaming from the UAV. The integration of Augmented Reality (AR) techniques in the flight environment provides assistance in remotely piloted landings, and allows visualizing flight and environmental information that are critical to the mission. For example, when spatial and temporal knowledge of the wind speed is required, AR can be used to overlap wind speed vectors to the external real environment. Eventually, wind vectors and UAV position and attitude can be visualized in a Virtual Reality systems based on Cave Automatic Virtual Environments (CAVE) or stereoscopic view. Tests shows that the proposed tool and methodology can effectively support wind speed detection missions since it can improve operational safety and contribute to the accomplishment of mission goals.
Ceruti, Alessandro, Valyou, Daniel, Liverani, Alfredo, Marzocca, Piergiovanni
Improving Coordination Between Aircraft Development Processes Through Process Mapping and Simulation2013-01-20919/17/2013
Aircraft development projects at Bombardier Aerospace involve a large number of tasks executed by a network of professionals from various disciplines. As the complexity of products and the development process increases, it becomes more difficult to manage the interactions among tasks and people. In fact, it may be impossible to even predict the impact of a single design decision across the development process. At Bombardier, investigation has shown that there was a lack of communication between design processes when dealing with aeroelasticity information. This resulted in duplicated design effort, reduced quality, and increased time to complete tasks when small design changes from one task induced delays in other tasks. Processes that deal with aeroelasticity work integrate system inertial, aerodynamics and structural information to make aircraft models and perform analyses. These processes have been creating similar models to perform aeroelasticity analyses. A study was started to determine the effect of using a single aeroelastic model to reduce overall design effort. Due to the complexity of the engineering design processes, they were mapped and analyzed in order to gain insight into the structure of the aircraft development process. The work involved in aeroelasticity analyses was mapped using an activity-based approach where processes were decomposed into a series of individual tasks, then the pieces of information that were exchanged between pairs of tasks were mapped to determine information flows. Processes were then analyzed using several techniques, including structural analysis, critical input analysis, simulation, and resource requirements. The aircraft development process was improved by reducing the amount of aircraft model generation effort. This was done by sharing a single aeroelasticity model between the Dynamic and Loads processes. Results indicated that this would reduce development effort by 900 hours per aircraft development program.
Hisarciklilar, Onur, Sheikh, Omer Khalid Babar, Yadav, Harshad Ajit, Thomson, Vincent
Efficiency and Emissions Mapping of RCCI in a Light-Duty Diesel Engine2013-01-02894/8/2013
In-cylinder blending of gasoline and diesel to achieve Reactivity Controlled Compression Ignition (RCCI) has been shown to reduce NOX and particulate matter (PM) emissions while maintaining or improving brake thermal efficiency as compared to conventional diesel combustion (CDC). The RCCI concept has an advantage over many advanced combustion strategies in that the fuel reactivity can be tailored to the engine speed and load allowing stable low-temperature combustion to be extended over more of the light-duty drive cycle load range. Varying the premixed gasoline fraction changes the fuel reactivity stratification in the cylinder providing further control of combustion phasing and pressure rise rate than the use of EGR alone. This added control over the combustion process has been shown to allow rapid engine operating point exploration without direct modeling guidance. This paper explores the efficiency, emissions and combustion characteristics of RCCI with gasoline and ultra-low sulfur diesel fuel over a wide speed and load range in a light-duty multi-cylinder diesel engine leading to the creation of an RCCI engine map. The RCCI map was developed under self-imposed constraints which included a maximum cylinder pressure rise rate of 10 bar/deg and a CO emission limit of 5000 ppm. The RCCI map was developed using a mix of single and split diesel injections without the use of EGR for best brake thermal efficiency with lowest possible NOX emissions. RCCI emissions and performance results are compared to CDC on the same base diesel engine.
Curran, Scott, Hanson, Reed, Wagner, Robert, Reitz, Rolf D.
Sequential DoE Framework for Steady State Model Based Calibration2013-01-09724/8/2013
The complexity of powertrain calibration has increased significantly with the development and introduction of new technologies to improve fuel economy and performance while meeting increasingly stringent emissions legislation with given time and cost constraints. This paper presents research to improve the model-based engine calibration optimization using an integrated sequential Design of Experiments (DoE) strategy for engine mapping experiments. This DoE strategy is based on a coherent framework for a model building - model validation sequence underpinned by Optimal Latin Hypercube (OLH) space filling DoEs. The paper describes the algorithm development and implementation for generating the OLH space filling DoEs based on a Permutation Genetic Algorithm (PermGA), subsequently modified to support optimal infill strategies for the model building - model validation sequence and to deal with constrained non-orthogonal variables space. The development, implementation and validation of the proposed strategy is discussed in conjunction with a case study of a GDI engine steady state mapping, focused on the development of an optimal calibration for CO₂ and particulate number (Pn) emissions. The proposed DoE framework applied to the GDI engine mapping task combines a screening space filling DoE with a flexible sequence of model building - model validation mapping DoEs, all based on optimal DoE test plan augmentation using space filling criteria. The case study results show that the sequential DoE strategy offers a flexible way of carrying out the engine mapping experiments, maximizing the information gained and ensuring that a satisfactory quality model is achieved.
Kianifar, Mohammed Reza, Campean, Loan Felician, Richardson, Dave
Automatic Test-Case Generation for Hardware-in-the-Loop Testing of Automotive Body Control Modules2013-01-01614/8/2013
This paper reports an automatic method for creating test cases for hardware-in-the-loop (HIL) testing of the body control module (BCM) for automobiles. First, test cases are generated automatically using Unified Modeling Language (UML) modeling software with an automatic test generation add-on. In this work, Rhapsody from IBM with the automatic test generator (ATG) add-on is used to generate automatic test cases. Then, these test cases are converted into Extensible Markup Language (XML) Metadata Interchange (XMI) format. From this XMI format file, test cases for HIL are generated by mapping stimuli such as digital input/output, analog input/output, and controller area network (CAN) interfaces. For this mapping procedure, the pros and cons of Extensible Stylesheet Language Transformations (XSLT) and XML Query Language (XQuery) are discussed. In addition, the advantages of generating hardware test cases using model-in-the-loop (MIL) and software-in-the-loop (SIL) test cases are addressed. Once the HIL test cases are generated, they are downloaded to the HIL test system for real-time testing. This study used a National Instruments PXI-based hardware platform and LabWindows/CVI for the HIL system. The test conversion method discussed here can be used to test cases generated by any kind of test-case generator, as long as they can be converted into XMI format. This saves a great deal of effort compared with manual test-case generation for hardware tests, and the efficiency of the development process can be improved.
Shin, Ki-Wook, Kim, Shim Soo, Lim, Dong-Jin
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