Focus on the Workforce: Online Simulation Tools for Advanced WFD
Lessons learned in higher education can guide industrial training
Michigan Technological University (MTU)
Central Connecticut State University (CCSU)
Ohio Northern University (ONU)
At educational institutions, online CNC training has proven to be an advantage for students and educators alike. Software that simulates common production machines, such as Haas VF Series milling centers, and simulation of CNC lathes with emulation of Fanuc controllers, provides an opportunity for offline training. This approach is an alternative to requiring production downtime for training or establishing large machine tool laboratories dedicated to training.
There are several providers of advanced manufacturing CNC training materials, including Tooling University (TU), LLC, (Cleveland, OH) online at www.toolingu.com; Immersive Engineering Inc. (Bloomfield, MI) online at www.immersive.biz; and Mori Seiki USA Inc. (Rolling Meadows, IL) online at www.msuondemand.com. These entities all provide virtual CNC interactive emulators of machine controllers, and 3-D models of machine equipment such as lathes and milling centers. Each of these training systems is intended to be a supplement, not a substitute, for actual hands-on learning, either on the job or in a controlled laboratory setting. The online training provides a safe environment where students can familiarize themselves with systems and terminology prior to beginning hands-on training and becoming proficient at machine setup, programming, and implementing machine tool operations. The Immersive Engineering Inc. CNC virtual machining software uses 3-D CAD simulation for its machine tool emulator, which allows the user to virtually see the machine tool movement in response to the control panel inputs.
In addition to the opportunities to learn machining and CNC fundamentals online, there are several widely popular virtual CAD/CAM software packages available that simulate the CNC toolpaths generated from the 3-D CAD model geometry. These CAD/CAM packages include Siemens PLM Software NX CAM, Dassault Systemes V6, and Gibbs and Associates' GibbsCAM. These systems and others like them have the ability to generate toolpaths, simulate the toolpath in 3-D, and postprocess the toolpath to standard machine code as a substitute for manual programming, which saves manufacturers enormous amounts of time and money. Technical programs at colleges and universities around the country are turning to these methods as an alternative to traditional textbook approaches to teaching advanced manufacturing methods.
Combining the two skills of CNC programming and CAD/CAM is the objective of several workforce development efforts now underway. For example, some of these strategies have been implemented in Flint, MI, once the home to more than 80,000 General Motors production workers. In April 2009, a 14.2% unemployment rate was reported for Flint by the Bureau of Labor Statistics (Labor Force Data, 2009). At Flint's Mott Community College (MCC), the Workforce Development Department has been the recipient of several grants, including those from the US Department of Labor, Career Alliance, and the Michigan Department of Energy, Labor, and Economic Growth. Also, MCC's Regional Technology Initiative Department has received grants from the US Department of Defense, US Department of Education, and the National Science Foundation. Due to the high population of displaced automotive production workers, many of these grants at MCC involve retraining workers for advanced manufacturing jobs, and setting the eventual goal of completing a technical associate's degree program.
Another example of initiatives in workforce development training in the area of CNC technology is the effort of the Workforce Development Group Inc. of the State of Indiana to retrain unemployed recreational vehicle builders. The goal of this effort is to meet the needs of orthopedic device manufacturers by providing CNCrelated degree training at Northern Indiana's IVY Tech Community College (Valparaiso, IN) with continued education available at Vincennes University (Vincennes, IN) and Purdue University (Lafayette, IN).
Preserving the nation's position in the aerospace industry in times of global competition and economic challenges is a primary focus of the National Aerospace Leadership Initiative (NALI), a consortium of three regional centers in Connecticut, Ohio, and Pennsylvania. In 2004, the US Air Force began funding NALI as a means of bolstering the aerospace industry on which it relies. The leadership for this consortium is provided by the Connecticut Center for Advanced Technology (CCAT) and the National Center for Aerospace Leadership (NCAL), both of which have largely focused on innovations and enterprise in the aerospace industry as well as workforce development. CCSU has been working with CCAT/NCAL to support these efforts, specifically in the areas of digital manufacturing technologies, reverse-engineering, and virtual training tools.
A study of on-line learning was published in the proceedings of the 2006 American Society for Engineering Education (ASEE) Annual Conference and Exposition, which investigates the perceptions of teachers and students involved in problem-based simulation (PBS) activities used in design-engineering curricula. This study demonstrates that PBS activities have enhanced the curricula at MCC by introducing simulation as a design tool to better evaluate design solutions, thus providing a tool for students to better understand design concepts. It's also evident that teachers and students learned to value and trust the use of simulation software as a beneficial teaching and learning tool to evaluate and validate their own design solutions.
In the study, one group learned with PBS activities, while a comparison group received the standard instructional content. Approximately 85% of the students who participated in the first group responded that simulation is a beneficial tool because it allows them to visualize difficult concepts. Approximately 23% of the students also responded that the benefit of the simulation activities is the ability to visualize the mechanisms in 3-D.
Presented at the 2007 National Association of Industrial Technology (NAIT) conference and later published in a technical paper in 2008, a study done at Michigan Technological University involved the Immersive Engineering Inc. Virtual Training Environment (VTE) for CNC software, which makes the machine operating situation as close to reality as possible by emulating the actual equipment, controls, and manufacturing processes in a virtual environment. A group of students were exposed to the software before operating the actual CNC machine equipment, and then compared to a control group taught using the traditional textbook approach.
The quantitative post-test results from the study show a significant difference in the scores of the groups of students in the CAM course. The results from the small sample of students in this study cannot be generalized, but in this particular situation, the students given exposure to the VTE-CNC software performed better on the Milling Setup Module questions than did the group receiving only the lecture and lab components. Ratings of course-effectiveness by the students taught using the software were higher than those of the comparison group, which indicates a positive influence on student perceptions after using the emulation software. Also, reactions of the students indicate that they know simulation and/or emulation software is not a tool to replace the actual hands-on machine operation, but that it can reinforce the learning process.
During a course taught in the 2009 spring semester, a survey was given to students to determine the effectiveness of the online CNC emulation software. On this survey, 15 questions related to course objectives and the instructional technology used were asked. The response to the question: "Do you think it was advantageous to have the Immersive emulation software for the Haas control panel available online as an instructional tool for this course?" was that 78% believed it was an advantage. Students in this course primarily used the Immersive virtual CNC, but were also exposed to the Tooling University software through examples from the instructor's station. Based on this exposure, 50% of the students responded "Yes" to the question, "From your limited exposure to the Tooling University software, in your opinion, should the tutorials be an addition to course requirements?"
It is important to understand that, in this class, the online component had to be completed outside of class time. The post tests, which are part of the Immersive course material, were used as a small percentage of the student's grade as an incentive to complete the modules. When asked, "If the emulation software was a nongraded activity, would you use it to prepare for lab sessions?" 50% of the students responded that they probably would not.
The CCAT/NCAL group has provided CCSU with access to Immersive as part of an effort to evaluate and improve the system. In the 2008 spring semester, a study presented at the NAIT conference was conducted, in which Immersive was used to introduce students to basic CNC concepts in an introductory manufacturing course. This course introduces CNC concepts, including limited CAD/CAM-based programming, and includes a short laboratory exercise in the final weeks of instruction. All students completed the learning modules and performed a hands-on assessment using the actual machine tool modeled in Immersive. The laboratory assessment involved a list of tasks that included basic identification of important controls, and performance of simple functions. The assessment indicated that nearly all students were unable to complete all tasks unaided, and there were a few tasks that tended to be more difficult than others due to lack of preparation. Module post-test averages, which were generally high, indicate no apparent correlation between the students' online and laboratory testing results. A follow-up survey instrument was then administered to determine the student's capabilities before and after using Immersive and get their personal perceptions of this tool. The survey found that 83% of the students had little or no prior CNC experience, 78% found the Immersive exercises to be comfortable or challenging and the rest indicated that it was easy.
The Department of Technological Studies at ONU includes a major in manufacturing technology. Graduates of this program are able to work as manufacturing engineers or industrial technologists. The ONU curriculum includes a variety of classroom, online, and independent learning techniques in several of its classes, including manufacturing processes, robotics, CAD, and simulation.
The metallic-materials-and-processes class covers machining and welding, including lectures, hands-on labs, and out-of-class independent studies using TU online training materials. The TU materials have been excellent and cover a range of topics. They enable the students to study when convenient for them, and when they are in the best "disposition" for learning. Online tests are provided for each TU class, and are automatically evaluated for verification of student comprehension.
Initial issues with the TU component include the discovery that students only skim the material, and that they procrastinate their studies of the modules, "cramming" at the last minute for scheduled testing. This has been resolved by releasing the modules in batches of topics for three weeks, and giving the students periodic in-class tests with a sampling of the questions from the modules.
ONU also provides a series of classes utilizing advanced industrial computer simulation software, primarily based on the Catia CAD platform. Junior and senior-level students learn various applications through tutorials and simulation exercises, and then create independent projects to demonstrate and develop basic competencies. Student teams are then formed to complete projects at local manufacturing operations where they observe processes, create simulations, and present the results at the company facility. Much of the training for these classes includes online tutorials and practice exercises with the students working at a self-paced rate. Again there was an issue with students procrastinating and not adequately completing the individual tutorials. New procedures require students to submit periodic exercises.
Using the Online Manufacturing Tools, educators have learned the following lessons:
- Independent study self-paced tutorials can significantly enhance the learning experience,
- Periodic evaluation of hand-in assignments is necessary to ensure and document student progress,
- Opportunities for the students to be innovative and creative generate enthusiasm and engagement, and
- Hands-on applications of the topics that complement the tutorials are valuable to ingrain the lessons learned.
In education, grades and testing are the incentive for students to learn. For the displaced worker, motivation is the knowledge and certification gained through the virtual CNC training that may lead to successful continued employment in an advanced manufacturing career.
This article was first published in the March 2010 edition of Manufacturing Engineering magazine.