MRI/RUI – Acquisition of a Portable Large Scale Visualization System
for Nondestructive Evaluation
3.
Project Description
(a)
Results from Prior NSF Support
Grant in Progress: CMS-0079593, NSF-MRI, Development of a Configurable Thermal
Imaging System for Nondestructive Evaluation of Materials, $91,935, October 1 , 2000 –
September 30, 2002. (PI: John C. Chen Co-PI: Shreekanth A. Mandayam). The objective
of this project is to develop a thermal imaging system to detect mechanical damage in gas
pipelines. This system will augment existing magnetic imaging systems that are
currently employed for detecting corrosion damage in pipelines.
Status: The CCD imaging system has been developed, test specimens have been
fabricated and we are currently in the process of gathering data. Results from this
research activity will be presented at the annual Review of Progress in Quantitative
Nondestructive Evaluation, scheduled to be held in Bellingham, WA, in July 2002.
Grant in Progress: DUE-0088437, NSF CCLI, Hands on the Human Body, $162,326,
March 1, 2001 – February 29, 2004 (PI: Stephanie Farrell, Co PIs: Anthony J. Marchese,
Jennifer A. Kadlowec, John L. Schmalzel, Shreekanth A. Mandayam, Senior Personnel:
Paris Von Lockette, Edward C. Chaloupka). The goal of this project is to engage students
in the scientific discovery process via exploration of the engineering systems within the
human body using hands-on reverse engineering methods.
Status: Instructional modules have been developed for the Freshman Engineering Clinic
II course and will be implemented during the course of the Spring 2002 semester. Results
from this activity will be disseminated at the annual ASEE Conference and Exposition to
be held in Montreal, Canada in June 2002.
Grant in Progress: DUE-0088183, NSF-CCLI, Communications, Signal Processing and
VLSI: Education Under a Common Framework, $74,939, March 1, 2001 – February 28,
2003 (PI: Ravi P. Ramachandran, Co-PIs: John L. Schmalzel, Linda M. Head, Shreekanth
A. Mandayam, Steven H. Chin). The goals of this project are to configure novel methods
of combining the laboratory content of the following three Junior-II courses – Electrical
Communications Systems, Digital Signal Processing and VLSI Design.
Status: Laboratory manuals have been developed and are being implemented in the
Spring 2002 offering of these courses. Results from this activity will be disseminated at
the annual ASEE Conference and Exposition to be held in Montreal, Canada in June
2002.
(b)
Research Activities
Motivation and background
Nondestructive evaluation (NDE) continues remain a significant engineering enterprise
that is essential for assuring the integrity of a variety of large-, medium- and small-scale
infrastructure in the United States today. The increase in the number of aging aircraft in
our civilian fleet, deteriorating bridges and roadways (especially on the East coast) that
are essential for maintaining our transportation needs, have contributed to a concerted
effort by funding agencies, academia and industry to devise more reliable techniques for
in-line nondestructive inspection. In the wake of recent terrorist attacks, concerns have
been expressed regarding the security and safety of nuclear power plants and oil and
natural gas pipelines – key contributors towards maintaining the nation’s energy supply.
The NDE research and development community has continually exploited the ongoing
advances in telecommunications, micro- and nano-electronics, instrumentation,
computational methods, software development, etc. to better serve the needs of their
constituents. This proposal seeks support for developing methods to augment this
technology growth in NDE with a field that has seen a rapid evolution in recent years –
virtual reality.
Virtual Reality (VR) (Bryson 1993, Ellis 1994) is a synergistic combination of
cutting-edge computation, visualization and display technologies that simulates an
“immersive” environment, in which a user can interact with a dynamic, computer
generated environment. VR systems allow the user to intuitively create, perceive,
experience and explore a virtual environment that appears sufficiently “real.” The
relationship between the participant and the virtual environment can be defined using a
conceptual VR model, based on a concrete understanding of human perceptual systems
(Gibson 1986).
Although VR systems can take a variety of forms, a typical implementation consists of
the following three elements – (a) immersion, (b) navigation, and (c) interaction, as
shown in Figure 1 (Krueger 1992). Immersion represents the degree of audio-visual and
sensory stimulation that is offered to the participant – it is a function of the level of user
interaction, type of display, the dimension, proximity and intimacy of the viewing
environment, image frame rate, model complexity, sound and sensory (touch) effects.
Techniques
VR
Immersion
Wireframe
Surface modeling
Texture mapping
Navigation
Translation
Rotation
Scaling
Interaction
Mouse
Head Mounted Displays
Data Gloves
Figure 1: Elements of VR.
Navigation refers to the ability of the user to explore the cyberspace; typical
techniques that are employed include object translation, rotation and scaling. Interaction
allows the user to manipulate the virtual environment and thus enhance the virtual
experience.
Recent advances in computer technology have had a significant impact on the quality
and cost of VR technology. Commercially available systems range from room-sized
synthetic environments (CAVEs) to desktop manifestations, offering limited, but
sufficient levels of immersion. There are two situations in which the application of VR
techniques can play significant roles in improving the NDE process:
(a) Defect characterization of NDE signals
(b) Virtual prototyping of NDE systems
A description each of these applications are provided below. In each case, specific
examples of research projects in the Rowan NDE laboratory are provided.
Defect characterization of NDE signals
Defect characterization mechanisms prevalent in the industry range from calibration
based approaches to simple parametric methods to sophisticated techniques using
artificial neural networks. A complete signal characterization system provides the
following capabilities:
(a) signal classification – this isolates defect signatures from signals obtained due to
benign changes in geometry.
(b) signal location – this is used to provide a precise location of the flaw with respect to
specimen geometry
(c) flaw profiling – this provides a 3-dimensional geometrical description of the flaw that
can be used by subsequent visualization stages.
A key requirement in modern NDE environments is the desire to reduce inspection
turnaround time – this places enormous demands on the data analyst. Reviewing and
digesting large amounts of data before deciding appropriate remediation measures
generates stressful conditions that can prove ultimately detrimental to the inspection
procedure. Data presentation plays a vital role in managing large volumes of both raw
and processed NDE data. With modest effort, current VR tools can be effectively
exploited to provide:
(a) Simultaneous display of NDE signals from multiple modalities and reconstructed
flaw profiles in the infrastructure
(b) Navigation though the infrastructure
(c) System response to user requests.
Objects displayed in the VR environment are classified as either static or dynamic.
Static objects are those whose shapes remain unaltered and they correspond to the
infrastructure in a defect-free state. These objects are generated using existing CAD
drawings of the structural part. The NDE signals and the predicted defect profiles are
dynamic objects, since their shapes reflect changing data conditions. The navigation
system allows the user to steer through a virtual world that is populated by various static
and dynamic objects. The environment also allows the generation of a printable log that
provides a concise list of the location and size of defects along with an indication of
severity.
The display environment could consist of a conventional monitor, a 3-D screen
projection (requiring special glasses) or a head mounted unit. Tactile responses can use
conventional mouse driven point-and-click signaling or employ sophisticated haptic
sensors. The virtual environment integrates the knowledge of existing CAD drawings of
the structural part with information generated by the data fusion and signal
characterization system. Successful adaptation of existing VR technology will provide
the data analyst with a powerful tool for assimilating information without overload.
Figure 2 shows a block diagram of an NDE system for natural gas pipeline inspection,
augmented with VR tools (Mandayam 1995, Mandayam 1996). One of the current
research projects in the NDE laboratory at Rowan requires developing techniques for inline inspection of natural gas pipelines using magnetic and thermal techniques. The
objective of this project is to develop a thermal imaging system to detect mechanical
damage in gas pipelines. This system will augment existing magnetic imaging systems
that are currently employed for detecting corrosion damage in pipelines. Current
technology involves the use of an in-line inspection vehicle called a “pig” that is
propelled inside of a pipe under the pressure of natural gas. The thermal sensors will be
in the form of a configurable array of infrared CCD cameras, which will permit the
complete imaging of the pipeline as the pig travels its length. The goal is to arrive at a
minimal modification of the current inspection tool design, making the system attractive
to pipeline-inspection vendors. The addition of a thermal-imaging sensor to the existing
magnetic sensor offers the opportunity for fusing the two data sets in order to improve the
accuracy and sensitivity of the inspection tool.
Virtual prototyping of NDE systems
VR technology can have significant impact on the design of NDE systems. VR provides
the opportunity to perform “virtual NDE”– simulating NDE processes from conceptual
design through service. This technique is also referred as “virtual prototyping” and has
been pioneered by the automobile and aircraft manufacturing industry. Following
extensive deployment of VR tools in the design of the newer cars and airplanes, this type
of simulation has gained a strong foothold as being part of the engineering design
process.
Figure 3 shows a typical concurrent engineering design cycle in which VR technology is
not used. Concurrent engineering refers to a paradigm in which time and effort is spent
on developing a production process, even at the initial stages of the design; and all steps
Test
object
Thermal Imaging
(Passive Monitoring)
Event triggered
Magnetic Flux Leakage
(Active Monitoring)
Signal Pre-Processing
Data Fusion
Signal Characterization
CAD
Drawings
VR Module
(Visualization)
Remaining Life
Prediction
Fracture
Mechanics
Models
User
Input
Expert
System
Suggestions
for
Remediation
3-D Reconstruction
Figure 2: Application of VR for defect characterization in the NDE of gas pipelines.
in the design process are continually evaluated and updated. In such a system, after
identifying a product/system need, Concept n, out of a total of N proposed concepts, is
taken through the entire design cycle from initial design calculation to final production.
The “Go – No Go” decisions for each proposed concept occur early on in the design
cycle – issues of project cost and time dictate this approach. Incorporation of VR
technology into the concurrent engineering design cycle allows this threshold to be
placed strategically, thus providing significant savings in personnel and process costs.
The following two scenarios are possible:
(a) (Figure 4) Concept n proceeds though the complete design cycle, but all of the
other concepts include a virtual prototyping stage after which they are each
accepted or rejected. The virtual prototyping facility allows the design team to
explore each competing concept comprehensively, before making a final design
decision. This method also allows the team to easily resurrect old concepts that
were discarded earlier, if they later show promise.
(b) (Not illustrated) The VR engine can provide a visual interface to every stage of the
design process – identifying resources/modifications required and streamlining
procedures. Such a design process is called Virtual Engineering. It can be a
powerful method to explore parts of the design process that are difficult to
incorporate in an educational environment; for example, manufacturing.
An example of a current R&D project in the NDE laboratory that can be significantly
enhanced with the application of virtual prototyping is a magnetic imaging system being
developed for a local HD-TV manufacturer. The objective of this project is to design,
develop and test a system for acquiring and displaying the magnetic flux density vector in
3-D space inside a HD-TV internal magnetic shield. This project will provide the sponsor
with a PC-controlled, semi-automated test facility for a minimally invasive interrogation
of the magnetic field inside the magnetic shield. An early prototype design of the
interrogation mechanism is shown in Figure 5.
Need
Concept (1)
Concept (N)
Concept (2)
....... Concept (n) ............
Reject
Reject
Calculation &
Experimentation
Production
Concurrent
Design
Test &
Measurement
Simulation
Rapid
Prototyping
Figure 3: Conventional concurrent engineering design flow model.
Need
Concept (1)
Calculation
&
Experimentat
ionSimulation
Concept (N)
Concept (2)
Calculation
&
Experimentat
ionSimulation
Virtual
Prototyping
Virtual
Prototyping
Reject
Reject
....... Concept (n) ............
Calculation &
Experimentation
Production
Concurrent
Design
Test &
Measurement
Rapid
Prototyping
Calculation
&
Experimentat
ionSimulation
Simulation
Virtual
Prototyping
Virtual
Prototyping
Reject
Figure 4: Virtual prototyping in the concurrent design flow model.
Hall Probe
Figure 5: Interrogation mechanism for imaging magnetic flux density inside a
HD-TV internal magnetic shield.
Proposed research directions
We propose to augment our existing capabilities in developing nondestructive evaluation
systems with state-of-the-art virtual reality display technology. We will explore and
develop novel mechanisms for:
(a) Visualizing defect characterization results from NDE procedures.
(b) Design process simulations for NDE systems applications.
The research project will actively involve the following constituents – faculty and
technicians, students and industrial consultants. The overarching goal of the proposed
research project is to enable the rapid transfer of VR technology to the NDE industry.
(c)
Description of Research Instrumentation and Needs
One of the principal objectives of this research project is to rapidly deploy state-of-the-art
VR technology in the NDE industry. The immersive capabilities of the VR system must
be sufficient to warrant a significant impact on the design and visualization in NDE
systems – yet the set-up and operation effort should not be prohibitive. The system
should be portable for ease of use. In addition, software support for the system should be
adequate so that the learning curve is not excessively steep. We therefore require a lowcost, self-contained, portable VR system that can be shared across the various
constituencies – faculty, students and industry.
We request support to acquire an ImmersaDesk® R2 visualization system
manufactured by FakeSpace Systems (please see quotation attached in the supplementary
documentation). In addition to providing a 82.5” diagonal viewing surface for active
stereoscopic imaging, the system provides for fully immersive and tracked user
navigation and interaction. The PC controlled system provides software for tracking four
sensors attached to the user. Furthermore, the system is portable (the shipping carton rolls
through standard sized doors) and set-up time is quoted to be 30 minutes.
Existing facilities related to NDE at the Rowan University College of Engineering
Faculty research in nondestructive evaluation is facilitated by the ongoing development
of a nondestructive evaluation laboratory. This laboratory currently houses high precision
linear motorized tables for scanning test specimens, equipment for conducting magnetic
flux leakage, DC potential drop, eddy current, ultrasound and microwave NDE tests,
along with the associated PC-based data acquisition modules. An Ascension Technology
Flock of Birds system provides 3-D motion capture capabilities. The lab contains HP
digital storage oscilloscopes, signal generators, microwave network analyzers, UT pulserreceiver modules and a 220A dc power supply. Pentium PCs, Sun and SGI workstations
connected to the Engineering LAN allow for on-site digital signal processing. Resident
software includes Matlab for algorithm development and Microsoft Visual C++ for
software development. A materials testing laboratory is located in the same facility. This
houses a 60,000 lb universal testing machine, a metallograph unit and provides other
destructive testing capabilities. Also in the engineering building is the machine shop,
which allows for rapid fabrication of test specimens. Furthermore, the Rowan College of
Engineering has close ties with nearby Camden Community College, that contains a
computer integrated manufacturing unit. All of the above facilities provide the Rowan
engineering faculty ready access to state-of-the-art materials characterization capabilities.
(d)
Impact of Infrastructure Projects (RUI Impact Statement attached with the
Supplementary Documentation)
The educational objective of this project is to provide a unique experience for
undergraduate students at Rowan University to conduct this project in a multidisciplinary
systems engineering environment and to provide them with skills needed for and desired
by industry. We propose to achieve this objective within the setting of the Senior
Engineering Clinic.
In 1992, local industrialist Henry M. Rowan made a generous donation of $100
million to the then Glassboro State College to establish a high quality engineering school
in southern New Jersey. This gift has enabled the university to create one of the most
innovative and forward-looking engineering programs in the country. The College of
Engineering at Rowan University is composed of four departments: Chemical
Engineering; Civil Engineering; Electrical & Computer Engineering; and Mechanical
Engineering. Each department has been designed to serve 25 to 30 students per year,
resulting in 100 to 120 students per year in the College of Engineering. The size of the
college has been optimized such that it is large enough to provide specialization in
separate departments, yet is small enough to permit the creation of truly multidisciplinary
curricula in which laboratory experiences and design courses are offered simultaneously
to students in all four disciplines. The hallmark of the engineering program at Rowan
University is the interdisciplinary, project-oriented Engineering Clinic sequence.
The Engineering Clinic is a series of courses taken each semester by every
engineering student. In the Engineering Clinic, which is based on the medical school
model, students and faculty from all four engineering departments work side-by-side on
multidisciplinary laboratory experiments, design projects, applied research, and product
development. While each clinic course has a specific theme, the underlying concept of
engineering design pervades throughout. The clinic progression gives us a way to
systematically develop our students as collaborative designers. Freshman engineering
introduces design through reverse engineering; at the sophomore level, students learn
structured design and get their first, open-ended project experience. Students in the Junior
and Senior Engineering Clinics work in multidisciplinary design teams on projects of
progressive complexity.
The four-year, 22-credit Engineering Clinic sequence offers students the opportunity
to incrementally learn the science and art of design by continuously applying the
technical skills they have obtained in traditional coursework. This just-in-time approach
to engineering design education enables students to complete ambitious design projects
as early as the sophomore year. It is within this truly innovative Clinic that we intend to
use this project as a Senior Multidisciplinary Design Project.
Incorporating design, development and testing of the VR system into the Senior
Engineering Clinic will satisfy both technical and educational objectives. From a
technical standpoint, the Engineering Clinic will provide the project with a competent,
experienced, multidisciplinary workforce of students and faculty from all four disciplines
within the College of Engineering. From an educational standpoint, the project will
provide senior undergraduate students the opportunity to take part in a complex,
multifaceted project culminating in the production of prototype hardware and software.
(e)
Project and Management Plans
As mentioned earlier, this project involves the following constituents:
(a) Faculty and technicians: The PI and co-PI’s will share in the oversight of the
proposed project. Together, the investigators will oversee a team of 5 – 8 senior
undergraduates in this Senior Clinic project. The technicians (Electronics,
Computer and Mechanical) will provide support for fabrication and system
support.
Dr. Shreekanth Mandayam (PI) is graduate from Iowa State University’s
NDE group, and has been extensively involved in the design and development of
nondestructive evaluation systems, both as part of his graduate work and as a
faculty member at Rowan University. He has established a thriving NDE
laboratory at Rowan, with sponsorship from NSF, US Army TACOM, Water
Environment Research Foundation, etc. He also possesses considerable
experience in developing virtual reality models for visualization of
nondestructive tests in gas transmission pipelines. He has worked in the Iowa
Center for Emergent Manufacturing Technology (ICEMT) which has one of the
few CAVE VR environments in the world.
Dr. John L. Schmalzel (Co-PI) has over 20 years of expertise in
instrumentation development for research and product-development applications.
He has taught capstone design courses over a 15-year period and is
knowledgeable in a variety of prototyping technologies (Schmalzel 1989-1992).
He has prior NSF-ILI project support for laboratory development, so will be able
to bring those successes to bear on this project. In particular, he has a track
record of results dissemination from similar projects.
Dr. Robi Polikar (Co-PI) is also a graduate from Iowa State University’s
NDE research group. He has considerable expertise in developing defect
characterization algorithms for NDE signals and bio-instrumentation.
(b) Students: The students will be assigned, as per the usual Clinic method, by the
discipline managers (faculty members) from each of the four engineering
departments. It is expected that students from all four disciplines will comprise
this team. The team will be set up in much the same way as an engineering team
in industry, and it will be managed through a combination of small group
meetings with individual investigators and entire team meetings for system-level
issues. Vertical integration across the graduate (Master’s level) and
undergraduate curriculum is achieved by the support of 1 graduate student.
(c) Industrial affiliates: The collaborating industrial consultant from Physical
Acoustics Corporation, Princeton, NJ, will provide input to the faculty, students
and technicians in order to facilitate technology transfer. This company has a
track record of collaboration with Rowan’s NDE group since 1998 (please see
letter of support in the supplementary documentation section).
The project is expected to be completed in two phases, roughly divided equally over
two years. During year 1, the VR system will be purchased, installed and calibrated.
The research team will familiarize themselves with the operation of the system and
begin developing procedures for integrating this added capability into existing NDE
projects in the laboratory. In the second phase of this project procedures will be
developed specifically for:
(c) Defect characterization of NDE signals – characterization results from magnetic
and acoustic NDE signals will be visualized
(d) Virtual prototyping of NDE systems – a magnetic imaging system will be
prototyped.
The project team will provide recommendations for adapting the procedures
developed for other NDE processes. During all stages active feedback from our industrial
constituent will be used for developing the research protocols.
Dissemination Activity
The main venues for the dissemination of research activity related to new contributions to
NDE will be at the annual conferences of the Review of Progress in Quantitative
Nondestructive Evaluation and the Fall and Spring Conferences of the American Society
for Nondestructive Testing. These conferences are well attended both by academia and
industry. Experiences in educational scholarship activity as a result of involving
undergraduate students in research will be disseminated at the annual conference of the
American Society for Engineering Education and the Frontiers in Engineering
conference.