ARC Collaborative Research Seminar Series
Winter 2012

ARC members can download the presentation files on our password-access online portal iARC.
Non-ARC members please email arcweb-info@umich.edu with your requests.

If you wish to attend the seminar remotely, please contact William Lim (williamlim@umich.edu) for teleconference details.


January 27th, Friday (9:00 - 11:00am)
University of Michigan, UM North Campus, EECS Room 1005

Internet-Distributed Hardware-in-the-Loop Simulation:
A Sliding Mode Control Approach to Improving Fidelity and an Overview of Efforts to Expand into Multi-Site ID-HIL    by Tulga Ersal, Akshar Tandon, Brent Gillespie, Mark Brudnak, Marcella Haghgooie, Jeffrey L. Stein (The University of Michigan, U.S. Army TARDEC, Applied Dynamics)

      Internet-distributed hardware-in-the-loop simulation (ID-HILS) refers to a networked simulation of geographically-dispersed hardware and software components of a system and presents unique opportunities for concurrent systems engineering. In this talk, we will summarize our ongoing efforts on two fronts to realize the full potential of ID-HILS. First, we will discuss a sliding mode control approach to improving fidelity in ID-HILS that is otherwise compromised due to the geographically-distributed simulation (e.g., the Internet’s delay, jitter, and loss; sampling effects; etc.). Second, we will present an overview of our efforts to expand our work, both theoretically and experimentally, into ID-HILS with more than two sites. We will outline our plans for an ID-HILS of an M-ATV with a hybrid electric powertrain as a 2012 ARC Conference Case Study.

Evaluation and Performance Modeling of User Interfaces for UGVs
by Steve Vozar, Dawn Tilbury (The University of Michigan)

      Reliable operation of teleoperated mobile manipulators is often compromised by a lack of operator situational awareness. In particular, when the robot is out of the line-of-sight, operators often get disoriented and lose perspective when relying on the first-person video feed. This project uses Augmented Reality (AR) and Virtual Reality (VR) visualizations to provide supplemental information about spatial relationships within the robot task space not otherwise available to the user. In this talk, we will present the results from our preliminary user study which showed promising results for improving situational awareness, and discuss our plans for the next phase of tests. In addition to AR and VR, we are considering incorporating innovative manual control interfaces such as a master-slave arm.

ARC Business meeting and Case Study discussion

February 10th, Friday (9:00 - 11:00am)
University of Michigan, UM North Campus, EECS Room 1005

Multilevel Vehicle Design: Fuel Economy, Mobility, and Safety Considerations
Steven Hoffenson, The University of Michigan

      Vehicle occupant safety is a top priority for ground vehicle designers, and in recent years the greatest threat to soldiers has been from underbody vehicle blast events. Other major, and sometimes concurrent, threats include those to fuel convoy vehicles and vehicle rollover events. Ground vehicle designers make choices that affect one or more of these personnel threats, including the weight and structural design of the vehicle underbody as well as the design of seating systems that cushion the occupants from the rapid accelerations caused by blast loading. This study uses mathematical and computational tools to evaluate the three aforementioned threats and combine them into a single-objective design optimization formulation that minimizes personnel casualties. The formulation is highlighted and described in detail, and preliminary results are presented.

Measurement and Modeling of Seated Soldier Posture and Body Shape
Matthew P. Reed and Sheila M. Ebert-Hamilton, The University of Michigan

      The design of military vehicles is hampered by the lack of accurate models to represent soldiers’ body size, shape, and posture, and particularly the effects of body armor and body-borne equipment. A study currently underway will develop new design guidance for vehicle and seat design while providing the research basis to upgrade commercial human models to accurately represent soldiers. Soldiers at three Army bases are being measured using a high-resolution 3D laser scanner and coordinate measurement equipment in a wide range of seated and standing positions wearing four levels of clothing and equipment. We will present preliminary results from the ongoing data collection and discuss analysis methods and applications.


February 24th, Friday (9:00 - 11:00am)
U.S. Army TARDEC, Warren, MI. NAC East Conference Room
This is a U.S. government facility. U.S. citizenship is required for entry. Foreign attendees must obtain security clearance at least one week before the event. Please contact andrea.m.simon.civ_at_mail.mil for requests.
For ALL driving on base (citizen or foreign visitor), they will need to stop at the visitor's center and provide registration and proof of insurance for their vehicle.
Remote attendance details to be announced

Bayesian-based validation of models with multivariate functional output
Hao Pan, Michael Kokkolaras, Gregory Hulbert, The University of Michigan

      There exists a plethora of validation approaches and methods, but not all of them are applicable to all types of models. Models of dynamic systems generate functional output, i.e., time histories. Often, the transient behavior of the systems is of interest, and so the entire time history predictions must be of adequate accuracy instead of just some of their features. Moreover, many dynamic system models have multivariate output. This talk will discuss appropriate validation methods for models with multivariate functional output. While we focus on methods that quantify model confidence by computing risk-based Bayes factors using hypothesis testing, we will also consider other approaches and discuss advantages, assumptions and limitations. We illustrate our investigations by means of a widely used validation benchmark problem that was formulated for a validation workshop organized by Sandia labs. We will also give a brief report on our involvement in the activities of a tri-force community of interest on model sharing and VV&A (validation, verification and accreditation) for power/energy applications.

Accelerated Testing for Vehicle Systems using Time-Dependent Reliability Principles
Zissimos P. Mourelatos (Oakland University), Amandeep Singh (TARDEC),
Igor Baseski (TARDEC & PhD Candidate, Oakland University)

      Reliability usually degrades with time increasing the product lifecycle cost. It expresses the probability that the product will perform its intended function successfully for a specified time. It is desirable to use accelerated testing to predict vehicle reliability using a few tests of short duration. Considering that certain vehicle parameters and the vehicle excitation are random, many vehicles must be tested which is impractical. To address this challenge, we are developing an accelerated testing approach based on both experiments and analysis. The method uses available tests to calibrate a simulation model which is then used to determine the failure rate of the vehicle fleet. Model V&V principles are used to calibrate the model. The failure rates are estimated using a subset simulation technique with Markov Chain Monte Carlo (MCMC). This talk will provide details including progress to-date. The methodology will be institutionalized at the TARDEC Physical simulation lab. Details will highlight our efforts to build a test rig at TARDEC and discuss future plans.

A Blast Event Simulation Process for Multi-Scale Modeling of Composite Armor for Light Weight Vehicles
John Kim, Nickolas Vlahopoulos, The University of Michigan

      Lighter weight military vehicles facilitate faster transport, higher mobility, fuel conservation, and a reduced ground footprint of supporting forces. Composite materials provide some of the most viable options for manufacturing composite armor that can increase survivability without significant weight penalty. A multi-scale simulation process using the coupled MAC/GMC and ABAQUS explicit codes for computing the response of a structure subjected to a load from an explosion has been established during earlier stages of this project. In this presentation the most recent efforts in incorporating micro-constitutive material behavior at high strain rate loading in the simulation process, and formulating an inverse mapping capability for linking desired material properties with the composition of their micro structure in MAC/GMC will be discussed.


April 5th, Thursday (9:00-11:00am)
University of Michigan, UM North Campus, EECS Room 1005

Solid Oxide Fuel Cell/Gas Turbine Combined Cycle Power System
Jing Sun, Soryeok Oh, The University of Michigan
Herb Dobbs, Joel King, U.S. Army TARDEC

      Combining solid oxide fuel cell and gas turbine (SOFC/GT) system has the obvious advantage of exploiting the complementary features of the two power plants for clean and efficient power generation. While high system efficiency of the combined system has been demonstrated for steady state operation, the tasks of transient operation and load following, complicated by the intricate and coupling dynamics, remain very challenging. Expanding our recent working on modeling and model-based control design and analysis for SOFC/GT systems, we have been investigating the extended SOFC/GT system with both energy storage and dual-mode operation of the generator/motor. We have evaluated the feasibility of dual-mode operation of the electric machine, and explored its control space to identify the associated benefits as well as its limitations. Algorithms are developed to leverage the machine for fast power tracking and temperature control in dynamic load following cases. Simulation results will be presented to illustrate the benefits of the dual mode operation of the electric machine in the SOFC/GT system and their implications to the energy storage sizing. In parallel, hardware simulation bench development work is underway to develop a platform for model validation and control implementation and evaluation. An update of the progress on the bench development will also be given.

Stroboscopic Imaging of Lithium concentration for Validation of Electro-Chemical Models in Power Applications of Li-Ion Batteries
Anna Stefanopoulou, Jason Siegel, The University of Michigan

      In this talk we'll present a stroboscopic imaging technique using neutron radiography for the quantification of the lithium concentration gradients across commercial electrode during transients. Seeing with sub-micron resolution, among other things, electrode expansion and contraction during cycling is an unprecedented achievement that enables the verification and advancement of fundamental electro-chemical assumptions in battery prognostic modeling during high charge and discharge rates.
      We'll highlight the challenges we faced in obtaining these measurements and the systematic steps in validating models of various fidelity from CFD to real-time computation.
      Strong collaborations allowed us to surpass many technical limitations, namely design of experiment and material selection with Ding Yi from TARDEC, battery fabrication with Patric Hagans and Danny King from A123, instrumentation with Dan Hussey and David Jacobson from NIST, statistics with David Gorsich from TARDEC, battery simulation software with Matt Castannier from TARDEC, model reduction and verification with Dyche Anderson from Ford, and fundamental battery transport phenomena with Charles Monroe from UMICH and Steve Harris from GM.

Automotive Thermal Management – Thermoelectric and Vapor Compression Cooling with Application to a Hybrid Vehicle Battery Pack
Joshua Finn, William Tao, and John Wagner, Clemson University

      The operation of military vehicles in extreme temperature environments requires robust thermal management systems to effectively remove heat from the passenger compartment and powertrain components. The increasing need for heat rejection may be partially attributed to a greater emphasis on vehicle electronic content and alternative energy sources. To maintain an acceptable range of temperatures, thermoelectric and vapor compression cooling strategies are under investigation. First, a concluding ARC study will be presented in which thermoelectric devices have been applied using the concept of cooling zones to offer localized temperature regulation for electronic equipment and compartment occupants. Second, a new project examining the modeling and real time control of a vapor compression system for hybrid vehicle battery pack cooling will be presented and discussed.


ARC members can download the presentation files on our password-access online portal iARC.
Non-ARC members please email arcweb-info@umich.edu with your requests.