Browse Topic: Digital twin

Items (36)

Scientists Fuse Simulations and Machine Learning to Accelerate Novel Additively Manufactured Materials

TBMG-5212712/01/2024

Researchers at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, have demonstrated a novel approach for applying machine learning to predict microstructures produced by a widely used additive manufacturing technique. Their approach promises to dramatically reduce the time and cost of developing materials with tailored physical properties and will soon be implemented on a NASA-funded effort focused on creation of a digital twin.

Generation of tire digital twin for virtual MBD simulation of vehicles for durability, NVH and handling evaluation

2024-26-030101/16/2024

With the recent development in virtual modelling and vehicle simulation technology, many OEM's worldwide are using digital road profiles in virtual environment for vehicle durability load prediction and virtual design evaluation. For precise simulation results, it is important to have the tire digital twin which is the realistic representation of tire in the virtual environment. The study comprises of discussion about different types of tire models such as empirical, solid model, rigid ring model and flexural ring models such as Pacejka, MF Swift, CD tire, F tire etc. and also the complexity involved in development of these tire models. Generation of virtual tire model requires highly sophisticated test rigs as well as vehicle level testing with Wheel Force transducers and other vehicle dynamics sensors. The large number of data points generated with testing are converted in standard TYDEX format to be further processed in various software tool for virtual model generation. Thus, a

Bakal, Nikhil

Electric Vehicle Battery SOH and RUL prediction using Digital Twin Hybrid ML Model considering effect of Driving Behaviour

2024-26-012201/16/2024

The adoption of Electric Vehicles (EVs) is primarily limited by their dependence on batteries, which have lesser power density as compared to conventional fossil fuels as well as its ageing deterioration issues over time. Therefore, there is an urgent need to understand the modifications in battery performance characteristics with respect to changes in temperature, charging behaviour and usage pattern, low and high charge states, current variations etc. To resolve such issues, this work proposes the development of a battery digital twin model to accurately reflect battery dynamics during run time. A digital twin is a virtual model replicating a physical system's characteristics. The digital twin is developed using a physics and machine learning model trained with bench-level and vehicle level actual test data. It uses an equivalent circuit model (ECM) to predict the battery's internal resistance and polarization effect due to ionic diffusion process in the cell. ECM model generates

Dongaonkar, Saharsh, Sarkar, Prasanta, Patil, Gaurav, KONDHARE, MANISH, nath, Subhrajyoti

An AI-based digital twin of the Electric Vehicle

2024-26-009301/16/2024

For commercial vehicles, reliability is key since the vehicle is typically linked to the daily earnings of the owner. To ensure continuous vehicle operation, early issue diagnostics and proactive maintenance are important. However, an electric vehicle is a complex and dynamic system consisting of numerous components interacting with each other and with external environments such as road conditions, traffic, weather, and driving behavior. Thus, vehicle operation and performance are highly contextual and for identifying an abnormal operation (diagnostics) the solution must take into account the conditions under which it is driven. To address this, we have built an AI-based digital twin of electric vehicles. The model is an AI-based generative transformer network that generates near-ideal vehicle behavior. The present focus has been on motor, controller and battery. The model is trained using 200 vehicles first 1500 km driven data. To ensure the digital twin model learns near-ideal

Jain, Siddhant, Kumar, Vedant, Soni, Nimish, Saran, Amitabh

Machine learning based fault detection of powertrains in electric vehicles using a digital twin

2023-01-121406/26/2023

Vehicles are subject to effects that lead to a more or less rapid degradation of functions. On the one hand, aging effects lead to a gradual reduction in functional capability. On the other hand, unexpected defects in components or modules can lead to functional losses. Therefore faults in the powertrain or vehicle dynamics can cause hazards for the driver as well as uninvolved road participants. They must therefore be detected and intercepted as early as possible in order to maintain vehicle function even in critical situations until a safe operating mode can be established without any risk. This contribution presents an approach that can improve both the product development process and the operation of electrified vehicles by dynamically detecting abnormal situations in the powertrain and vehicle dynamics to infer the fault in the system. For this purpose, the vehicle is connected via 5G to an intelligent digital twin located in the Edge backend. The core component is the fault

Dettinger, Falk, Jazdi, Nasser, Weyrich, Michael, Brandl, Lukas, Reuss, Hans-Christian, Pecha, Urs, Parspour, Nejila, Li, Shiqing, Frey, Michael, Gauterin, Frank, Nägele, Ann-Therese, Lüntzel, Vitus Alexander, Sax, Eric

The DANA EV NVH Laboratory

2025-01-000705/05/2023

A cutting-edge EV powertrain NVH laboratory has been established at DANA Incorporation’s world headquarters in Maumee, enhancing their capabilities in EV powertrain NVH development. This state-of-the-art and industry lead laboratory is designed to meet various NVH requirements for EV powertrain development and sign-off processes. This laboratory supports the use of a live motor for input and is equipped with an input module that allows for detailed examination of NVH characteristics of new powertrain configurations before prototype motors are available, significantly reducing development time for new drivetrain systems. Key features of the laboratory include a hemi-anechoic chamber, two AC asynchronous load motors, an acoustically isolated high-speed input motor, and two battery emulators that cover both low and high voltage requirements. The NVH laboratory enables engineers to assess system performance and correlate it with digital twin models. DANA engineers can develop and optimize

Cheng, Ming-Te, Zugo, Chris

Condition Monitoring of High-Speed Rotating Machinery using Digital Twins & Machine Learning Techniques

2025-01-012805/05/2023

In the era of Industry 4.0, maintenance of factory equipment is changing with new maintenance system using predictive or prescriptive methods. These methods leverage condition monitoring through digital twins, AI, & machine learning techniques to obtain early signs of faults, type of faults, locations of fault etc. Bearings and Gears are one of the most common components and cracking/misalignment/rubbing/bowing are the most common failure modes in high-speed rotating machinery. In the present work, an end-to-end automated Machine Learning based condition monitoring algorithm is developed for predicting and classifying internal gear and bearing faults using external vibration sensors. A digital twin model of the entire rotating system consisting of the gears, bearings, shafts, and housing was developed as a co-simulation between MSC ADAMS and MATLAB. The gears and bearing dynamic models were developed in MATLAB and shaft and housing models were developed in MSC ADAMS flexible body. The

Rastogi, Sarthak, SINGHAL, SRIJAN, Ahirrao, Sachin, Milind, T. R.

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SAE-PP-0778011/01/2022

test 11/01/2022 10:40 am

Mutagaana, Festo

Cloud based Architecture to implement Digital Twins

2022-26-114705/26/2022

Increased operating cost of aircraft for maintenance and repair is an area that has garnered a lot of attention. Efforts to reduce the cost has not always met with success despite aircraft being built with increased reliability including more durable engines and innovations in approach to maintenance. Most airlines focus on cutting cost of maintenance, repair and overhaul while ensuring operational availability of assets. Means to optimize cost must always be within mandatory bounds of safety of operations. Existing approaches for fleet management and sustainment are largely based on statistical distributions of material properties, physical testing and heuristic design philosophies which are often unable to address extreme requirements. Some of the major challenges include employment of conventional maintenance practices, slower turnaround time, suboptimal supply chain management, poor utilization of resources, below par manufacturing processes, outdated manual processes and inferior

Padmanabhan, Suresh, Sunkara, Bhanu Prakash

Using Digital Twin for faster & accurate performance prediction of Industrial Assets.

2022-26-114605/26/2022

Digital Twin is an emerging trend on Industrial use cases. Digital Twin is a Replica of a physical asset in Real time. The traditional way of developing Digital twin is, by using complex transfer functions. However, this requires tremendous amount of expertise with good understanding of the domain & the physics. The accuracy of the Twin model is directly dependent on the transfer functions, which many times result in a disconnect with the physical world. Physics based simulations can result in a better accuracy. However, the time taken by the software to make Real time virtual simulations is a bigger Industrial challenge due to high computational speed. So, we need to strike the right balance between speed & accuracy. There are some software who are attempting to provide solutions to this challenge. One of the techniques is to use Reduced Order Modelling (ROM) to speed up the computation of virtually simulating complex Industrial assets, without too much of approximation. The intent of

Narasimhan, Vijay Sarathy

Blockchain based Aircraft Maintenance Records

2022-26-114005/26/2022

Currently, Aircraft records and many other archives are in paper format. Paper records like maintenance records included in logbook are cumbersome, inefficient, and insecure compared to the capabilities of modern technology. Blockchain technology is the next step in creating process efficiencies, security, and integrity of maintenance data over the lifetime of an aircraft/engine. Changing paper records to digital records using blockchain is the foundation for a better future towards digital twin and analytics. Blockchain based maintenance can connect a world of data between various groups for extended periods of time by creating a secure digital thread. As regulatory requirements grow and cyber threats loom, blockchain technology can assist in the integrity and security of the captured data. The objective of this paper is to describe the advantages of migrating to digital applications using blockchain and how it can secure the future of the industry.

Jayarajan, Keerthi

Application of a Digital Twin Virtual Engineering Tool for Ground Vehicle Maintenance Forecasting

2022-01-043403/29/2022

The integration of sensors, actuators and real time control in transportation systems enables intelligent system operation to minimize energy consumption and maximize occupant safety and vehicle reliability. The operating cycle of military ground vehicles can be on- and off-road in adverse environments which places a demand on continuous subsystem functionality to fulfill missions. On–board diagnostic systems can alert the operator of degraded operation once established fault thresholds are passed. An opportunity exists to estimate vehicle maintenance needs using model-based predicted trends and compiled information from fleet operating databases. A digital twin, created to virtually describe the dynamic behavior of a physical system using computer mathematical models, can estimate the system behavior based on current and future operating scenarios while accounting for past operating effects. In this manner, the collection of real time data of the physical vehicle can be constantly

Eddy, Conner, WAGNER, Adam, Wagner, JOHN, Castanier, Matthew

Digitalization of a climate and altitude simulation test bench for handheld power tools to automate its thermal management system

2022-01-072703/29/2022

Mechanical systems accomplish their tasks better when enhanced with cyber technologies. With the rapidly escalating desire for high efficiency, optimization and flexibility, these physical systems ought to be integrated with cyber technologies that enhance exhaustive manipulation of resources and unsurpassed productivity. The gateway for such a synergetic integration can be referred to as digitization. Details regarding the digitization of a High-altitude Simulation chamber are discussed thoroughly in this paper. The simulation chamber was originally designed and developed as a test bench to study the characteristics of alternative fuels used in the engines of handheld tools in different altitudes and thermal conditions. It encompasses all the possible realistic temperature variations with altitude raising to 3500m above sea level. Since the testbed’s effectiveness is highly dependent on achieving a combination of desired temperature and altitude values to maintain them for a defined

Nenninger, Philipp, Hadamek, Christof, Renner, Marius, Derbie, Arsema, Kettner, Maurice, Aslan, Ferhat

Executable Digital Twin – Prevent the early failure of a truck anchorage using Smart Virtual Sensors

2022-01-093203/29/2022

Executable Digital Twins (xDT) are starting a revolution in the industry, where high fidelity simulation models extend their usage from the design and validation phases to in-operation and service phase. Two critical technology blocks in this revolution are Model Order Reduction and Smart Virtual Sensing. The former allows the high-fidelity models to be represented in compact forms and the latter allows to extend the limits of physical sensors and provide full field data combining simulation models and test data in a real-time estimator framework. The smart virtual sensing technology leverages a state-of-the-art Kalman filtering approach to combine the simulation and physical testing. This allows to virtually measure locations that are not accessible with physical sensors due to e.g. physical constrains or high temperatures. In case of large sensors setups, the instrumentation time, and hence the cost, can be greatly reduced by using a combination of physical and smart virtual sensors

Scurria, Leoluca, Risaliti PhD, Enrico, Buss, Dayane, Kubo, Pablo, Tamarozzi, Tommaso, Cornelis, Bram

The ICON Digital Wind-Tunnel Validation

2022-01-108803/29/2022

The discipline of aerodynamics engineering is a cornerstone in the rapid transition of the automotive industry to emission-free technologies. The endless pursuit of maximum energy efficiency, comfort, and safety requires designers to achieve unprecedented aerodynamic characteristics for the cars of tomorrow, which would be impossible to attain using traditional development processes. In recent years, computational testing has reached a maturity level close to that of physical wind-tunnel testing with all of its’ sophistications. Complementing the data from physical testing, well-calibrated computational simulations provide opportunities to interrogate and analyze salient flow phenomena in even greater depth, and explore the design space with more flexibility. Enabling designers to easily and efficiently exploit the increasing power and range of computational simulation to achieve the emission-free objectives of the automotive industry represents a significant challenge. This talk will

Hrncir PhD, Zbynek

Development of Argonne VIL workflow for CAVs to demonstrate the energy-efficient automated driving controls in real vehicles

2022-01-050003/29/2022

Argonne National Laboratory (ANL) has developed automated driving control strategies that aim at maximizing energy-efficiency. Up to 22% energy savings were demonstrated [1] in a large-scale study performed in RoadRunner, a tool for the energy-centric modeling of connected and automated vehicles (CAVs). This paper describes how these controls were implemented and tested in real vehicles on dynamometer setting, ANL vehicle in the loop (VIL) workflow, to demonstrate both the efficacy of the controls themselves, but also to validate the RoadRunner models. The main concept of the ANL VIL workflow is to build a digital twin and connect to a real vehicle on dynamometer as if it can drive on the real road. The ANL VIL workflow mainly consists of three steps, integration, preparation, and experimentation. A digital twin of the vehicle and the testing environment was built by the help of RoadRunner for the integration. The digital twin includes virtual road such as intersection, traffic signals

JEONG, Jongryeol, Kim, Namdoo, Di Russo, Miriam, Grave, Julien, Han, Jihun, Stutenberg, Kevin, Karbowski, Dominik

Innovation on a Larger Scale: Robotic Fiber Placement and 3D Printing

TBMG-3850602/01/2021

Washington, DC

Technology Leaders: Industry Renaissance Transforms Invention, Learning, Production, and Trade

TBMG-3819612/01/2020

A profound societal transformation is underway on a scale not seen since the great European Renaissance. Then, Gutenberg’s printing press made books — and the knowledge they contained — available to all. Today, the new book is the experience. Digital technology, which enables virtual experiences, is enabling an Industry Renaissance that is shaking all sectors of society with new ways, both real and virtual, of inventing, learning, producing, and trading.

How Digitalization Reduces Program Risk in Platform Development

TBMG-3745908/01/2020

Electronic and electrical (E/E) design demands of the 21st century will no doubt present a tremendous challenge throughout the aerospace and defense industry. Profitability in all phases of platform development will be challenged. Along with staying profitable, there is a need to innovate. But with innovation comes risk. How do you limit risk to stay profitable?

Digital Twins: How The Digital Replica Concept Is Used By Robotic Systems

TBMG-3709606/01/2020

AV&R's robotic systems are designed to automate surface finishing (profiling, polishing, blending, deburring) on critical parts of aircraft engines, such as blades. These systems operate using dedicated software called BrainWave which orchestrates the interactions between all of the robotic system’s components. For several years, AV&R has been developing BrainWave software to facilitate the use of the robotic system by its operators. One of the features developed is visualization of the system following the concept of digital twins.

DIGITAL TWINS

20AERP06_0406/01/2020

How The Digital Replica Concept Is Used By Robotic Systems AV&R's robotic systems are designed to automate surface finishing (profiling, polishing, blending, deburring) on critical parts of aircraft engines, such as blades. These systems operate using dedicated software called BrainWave which orchestrates the interactions between all of the robotic system's components. For several years, AV&R has been developing Brain-Wave software to facilitate the use of the robotic system by its operators. One of the features developed is visualization of the system following the concept of digital twins. What is the concept of digital twins? How does this innovative concept apply in the case of robotic systems for complex industries such as aeronautics? What are its concrete uses? And how do digital twins improve the use and performance of robotic systems?

Unsettled Technology Opportunities for Vehicle Health Management and the Role for Health-Ready Components

EPR202000303/17/2020

{"italic":"health-ready\n components","content":["Game-changing opportunities abound for the application of vehicle health\n management (VHM) across multiple transportation-related sectors, but key\n unresolved issues continue to impede progress. VHM technology is based upon the\n broader field of advanced analytics. Much of traditional analytics efforts to\n date have been largely descriptive in nature and offer somewhat limited value\n for large-scale enterprises. Analytics technology becomes increasingly valuable\n when it offers predictive results or, even better, prescriptive results, which\n can be used to identify specific courses of action. It is this focus on action\n which takes analytics to a higher level of impact, and which imbues it with the\n potential to materially impact the success of the enterprise. Artificial\n intelligence (AI), specifically machine learning technology, shows future\n promise in the VHM space, but it is not currently adequate by itself for\n high

Holland, Steve

Build it and they Will Come

20AVEP03_0803/01/2020

Moving beyond vehicles, Toyota plans to manufacture a whole city. There's hardly a region on Earth that Toyota doesn't reach. At the 2020 CES conference, the company announced a visionary project of similar scope, saying it intends to build a “prototype town of the future” to prove out new technologies of all kind, not just transportation-related. Toyota's Woven City is envisioned as “home to full-time residents and researchers who will be able to test and develop technologies such as autonomy, robotics, personal mobility, smart homes and artificial intelligence in a real-world environment.” Toyota CEO Akio Toyoda appeared genuinely energized in announcing Woven City, saying “having the opportunity to build an entire city from the ground up - even on a very small scale like this - is in many respects the opportunity of a lifetime.” He said the 175-acre site of a decommissioned Toyota manufacturing plant will be the foundation for Woven City, with groundbreaking beginning in 2021.

Visnic, Bill

Self-Expressive & Self-Healing Closures Hardwares for Autonomous & Shared Mobility

2019-28-252511/21/2019

Shared Mobility is changing mobility trends of Automotive Industry and its one of the Disruptions. The current vehicle customer usage and life of components are designed majorly for personal vehicle and with factors that comprehend usage of shared vehicles. The usage pattern for customer differ between personal vehicle, shared vehicle & Taxi. In the era of Autonomous and Shared mobility systems, the customer usage and expectation of vehicle condition on each & every ride of vehicle will be a vehicle in good condition on each ride. The vehicle needs systems that will guide or fix the issues on its own, to improve customer satisfaction. We also need a transformation in customer behavior pattern to use shared mobility vehicle as their personal vehicle to improve the life of vehicle hardwares & reduce warranty cost. We will be focusing on Vehicle Closure hardware & mechanisms as that will be the first and major interaction point for customers in vehicle. This gives us an opportunity to

Subramanian, Vijayasarathy, Kumar, Biju, Sivakrishna, Masani, Marappan, Anandakumar

Design and Implementation of Digital Twin for Predicting Failures in Automobiles Using Machine Learning Algorithms

2019-28-015910/11/2019

The drastic technological advancements in the field of autonomous vehicles and connected cars lead to substantial progression in the commercial values of automobile industries. However, these advancements force the Original Equipment Manufacturers (OEMs) to shift from feedback-based reactive business analysis to operational-data based predictive analysis thereby enhancing both the customer satisfaction as well as business opportunities. The operational data is nothing but the parameters obtained from several parts of an automobile during its operation such as, temperature in radiator, viscosity of the engine oil and force applied over the brake disk. These operational data are gathered using several sensors implanted in different parts of an automobile and are continuously transmitted to backend computers to develop Digital Twin, which is a virtual model of the physical automobile. Later, gathered operational data are analyzed using data mining algorithms to predict the failures of an

Balakrishnan, Ponnuraman, Ramesh Babu, Kalivaradhan, Naiju, Chooriyaparambil Damodaran, Madiajagan, Muthaiyan

Demonstration of Transformable Manufacturing Systems through the Evolvable Assembly Systems Project

2019-01-136303/19/2019

Evolvable Assembly Systems is a five year UK research council funded project into flexible and reconfigurable manufacturing systems. The principal goal of the research programme has been to define and validate the vision and support architecture, theoretical models, methods and algorithms for Evolvable Assembly Systems as a new platform for open, adaptable, context-aware and cost effective production. The project is now coming to a close; the concepts developed during the project have been implemented on a variety of demonstrators across a number of manufacturing domains including automotive and aerospace assembly. This paper will show the progression of demonstrators and applications as they increase in complexity, specifically focussing on the Future Automated Aerospace Assembly Phase 1 technology demonstrator (FA3D). The FA3D Phase 1 demonstrated automated assembly of aerospace products using precision robotic processes in conjunction with low-cost reconfigurable fixturing supported

Sanderson, David, Turner, Alison, Shires, Emma, Chaplin, Jack, Ratchev, Svetan

Challenges of Digital Twin in High Value Manufacturing

2018-01-192810/30/2018

Digital Twin (DT) is a dynamic digital representation of a real-world asset, process or system. Industry 4.0 has recognised DT as the game changer for manufacturing industries in their digital transformation journey. DT will play a significant role in improving consistency, seamless process development and the possibility of reuse in subsequent stages across the complete lifecycle of the product. As the concept of DT is novel, there are several challenges that exist related to its phase of development and implementation, especially in high value manufacturing sector. The paper presents a thematic analysis of current academic literature and industrial knowledge. Based on this, eleven key challenges of DT were identified and further discussed. This work is intended to provide an understanding of the current state of knowledge around DT and formulate the future research directions.

Singh, Sumit, Shehab, Essam, Higgins, Nigel, Fowler, Kevin, Tomiyama, Tetsuo, Fowler, Chris

OEMs progress to ‘functional engineering’ as digital tools evolve

18AUTP10_1010/01/2018

Now that the use of digital models and simulation make it straightforward to create a digital “twin” of any system in the vehicle, the industry is looking to move beyond geometric models. Automakers are gradually deploying functional models that augment existing models by providing parameters like behavioral and business information. Modeling and simulation have transformed the design, validation and testing worlds, letting design teams try out more options and complete projects more quickly. Many strategic planners now are looking to move forward with functional design tools. “Everything is in 3D, everything is modeled, but that's not enough,” said Bob Trecapelli, Director, Global Digital Innovation and CAE at Ford. “We've got to go to functional engineering-that's the next generation.”

Costlow, Terry

Connecting the Digital Twin: From Idea Through Production, to Customers and Back

TBMG-2904506/01/2018

Computing Remaining Fatigue Life Under Incrementally Updated Loading Histories

2018-01-062304/03/2018

After manufacture, every military vehicle experiences a unique history of dynamic loads, depending on loads carried, missions completed, etc. Damage accumulates in vehicle structures and components accordingly, leading eventually to failures that can be difficult to anticipate, and to unpredictable consequences for mission objectives. The advent of simulation-based fatigue life prediction tools opens a path to Digital Twin based solutions for tracking damage, and for gaining control over vehicle reliability. An incremental damage updating feature has now been implemented in the Endurica CL fatigue solver with the aim of supporting such applications for elastomer components. The incremental updating feature is demonstrated via the example of a simple transmission mount component. The damage state of the mount is computed as it progresses towards failure under a series of typical loading histories. The incremental updating feature enables both more realism in anticipating maintenance

Mars, William V., Suter, Jesse D., Bauman, Mark

New System Explores the Future of Automated Visual Inspection

TBMG-2868404/01/2018

The concept for a new automated visual inspection system that uses robotics to manipulate metallic components is being tested at the University of Sheffield’s Advanced Manufacturing Research Centre (AMRC).

Industry 4.0: Virtual Twin Controls Production

TBMG-2671404/01/2017

Efficient production control is a key industrial technology. The notion of building up two parallel factories instead of one may sound like nothing but doubling of effort. But what if one of the factories existed only in virtual form? This is the basic idea behind an innovative concept from the Fraunhofer Institute for Production Systems and Design Technology IPK in Berlin. The real factory is fully modeled at the digital level, creating a virtual twin that not only visualizes the production system with all its machines, but also reproduces the dynamic processes and the behavior of system components during production in real time.

Inverse Dynamic Reconstruction of Truck Cabin Ingress/Egress Motions

2009-01-228606/09/2009

This paper investigates the feasibility of calculating joint forces and moments during a whole body truck cabin ingress/egress motion. For such a task, it is difficult to evaluate a future truck instep as the influences of the architecture parameters are complex over the motion and the discomfort feeling. In order to evaluate the future product at an early stage of the design process, Digital Human Models (DHMs) are interesting tools. However, most existing DHM simulation packages can only efficiently evaluate the kinematics of postures where the dynamics of the whole motion is necessary for such a task. The enhancement of DHMs towards a dynamic analysis and modeling is therefore necessary. In this study, the motions of subjects entering and exiting an adjustable truck cabin were measured by mean of an opto-electronic motion capture system and six load sensors. The joint angles were then calculated using an inverse kinematics method. And the joint loads were calculated using a

Monnier, Gilles, Chateauroux, Elodie, Wang, Xuguang, Roybin, Christophe

Robust Human Motion Reconstruction in the Presence of Missing Markers and the Absence of Markers for Some Body Segments

2006-01-232107/04/2006

Optical motion capture systems are one of the most frequently used technologies for motion data collection. However, they are affected by the missing marker problem which is almost unavoidable for this technique. Another problem with motion capture systems is the impossibility of completely tracking the motion of some bones (e.g. vertebrae or scapula) using external markers fixed on the skin because they move under it. We propose three strategies for handling the missing marker problem and the lack of sufficient number of markers for determining the motion of some body segments. These strategies have been developed in the frame of a new reconstruction method called Optimal Tracking Method, which requires the solution of a nonlinear constrained optimization problem. The three strategies have been tested on fourteen movements collected by INRETS in the frame of the REALMAN project. The benefits, drawbacks and limitations of the three strategies are discussed.

Ausejo, Sergio, Suescun, Angel, Celigüeta, Juan, Wang, Xuguang

Validation of a Model-based Motion Reconstruction Method Developed in the REALMAN Project

2005-01-274306/14/2005

Realistic motion reconstruction is the first step for ‘human like’ motion simulation by a digital human. In a recent European research project REALMAN (IST 2000-29357), a model-based motion reconstruction method from external marker trajectories was developed. It consists of two steps. The first one is to define a digital twin of a real subject using the technique of superimposing a digital human model upon at least two photos of different view, and identifying marker positions on it. In a second step, joint angles are estimated by using a kinematic model of the human body which is described using natural coordinates: coordinates of points and components of unit vectors for defining the joint locations. The model includes a detailed description of the torso, arms and legs, with simplified hands and feet. A total of 26 joints are used, connecting 27 rigid links, among them 6 located on the spine. The joint angles are calculated by minimizing the distance between markers located on the

Wang, Xuguang, Chevalot, Nicolas, Monnier, Gilles, Ausejo, Sergio, Suescun, Ángel, Celigüeta, Juan

Reflective Type Electronic Clusters High Visibility and 3-D Image Electronic Display Cluster

87021002/01/1987

This paper deals with an electronic cluster based on a different concept from that which is viewed directly as conventional. In this cluster, the main display installed within the instrument panel (I/P) pad is designed to show a virtual image imposed over a real image of indicators which appears through a transflective mirror. Special consideration should be focused on the following salient points. 1) Superior visual and innovative factors, 2) design of transflective mirror to make it superior and 3) factors to consider in regards to the virtual image display type cluster.

Kuroyama, Toshinobu, Higo, Nobumasa

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