The research objective of this GOALI award is to develop and evaluate methods to support natural human interaction with digital CAD models with a focus on simulating manual assembly tasks in an immersive virtual environment. A hybrid method is developed which combines voxel-based collision detection and haptic rendering with enforcement of geometric constraints. An intelligent algorithm to manage the tradeoffs between the voxel-based collision detection and the enforcement of geometric constraints is a key component of this research. Evaluation will include both controlled experiments with students and a protocol analysis of the impact of the system on John Deere employees. The affordance of physical assembly provided by the virtual environment and the potential impact this capability has on the work actions of John Deere engineers will be examined. The participation of the Deere employees is a key component of this research as the system's application to a real-world manufacturing context could not be assessed without the active participation and close collaboration of our industrial collaborators.
If successful, the results of this research will have significant impact on engineering design and manufacturing. It will open many doors for the use of virtual reality as a product prototyping tool. In the design process, for example, design for assembly relies on designing to accommodate an operator?s ability to use tools, position components, attach parts, and reorient assemblies. All of these actions rely on humans interacting naturally with product geometry. Faster, easier prototyping through natural interaction with CAD models is a key component for achieving better product designs at reduced cost. Design for maintenance and training will also be positively impacted by this research. The results of the research will be disseminated broadly through journal papers, conference presentations, and demonstrations at technical meetings. Outreach in the form of hands-on demonstrations and workshop activities are planned for K-12 students through collaborations with the Program for Women in Science and Engineering and the Society of Women Engineers student section. Women and underrepresented groups will be recruited as part of the research team through partnerships with an existing ISU NSF Alliance for Graduate Education and the Professoriate program and an ISU NSF Research for Undergraduates Site program.
The research objective of this GOALI award is to develop and evaluate methods to support natural human interaction with digital CAD models with a focus on simulating manual assembly tasks in an immersive virtual environment. The motivation is to develop tools that will allow engineers to mimic assembly of products while the products are still in CAD form in order to identify potential issues in assembly processes that could be alleviated through changes to the product design. Issues that arise on the shop floor are very expensive to address if they involve changes to the product shape, function, tooling, etc. Therefore, identifying and fixing these issues before the product is manufactured holds the potential for significant cost savings. The underlying research fundamentals involve simulation of natural human interaction with products in an immersive computing environment. Intellectual merit A large number of bench assembly operations are performed with two hands; therefore, the virtual assembly environment must also support bimanual assembly. Engineers in industry who are interested in exploring the potential use of virtual reality for assembly methods prototyping are uncertain about what device configuration is sufficient to obtain reliable feedback from participants in decision making tasks. One of our studies compared the use of two haptic devices to the use of a non-haptic glove on one hand with a haptic device at the other hand. This last configuration would be less costly for industry and provide the user with a larger workspace since the gloved hand can reach quite a bit farther than the small desktop haptic devices. We learned from this study the glove/haptic device configuration does hold promise for providing at least the same performance in virtual assembly as a dual haptic device configuration. Another interesting result was that half of the participants in the study chose the non-haptic glove and haptic device as their preferred interaction configuration. These are encouraging results that will lead to further research on the use of a glove/haptic device hardware configuration for virtual assembly. Another one of our studies examined the effectiveness of virtual training compared to training with physical objects. Again, we are interested in the benefits of immersive computing technology to reduce costs to product designers/manufacturers. The results of that study indicated that although the participants in the virtual training took longer to complete the training, their performance on the real assembly task two weeks after training was improved, while the participants that were trained using the real physical objects demonstrated decreased performance after two weeks. This could indicate that users trained in the virtual environment retain the knowledge gained from training better than those trained with traditional methods. This result is consistent with a body of research in psychology that indicates increased training retention when training tasks require a lot of attention and concentration by the users. Our collaborators at John Deere hosted our visit to one of their manufacturing plants. We were able to observe a product review session that included engineers and shop employees discussing an upcoming product configuration change that would have an impact on the production process. It was very helpful to hear the discussion between the two groups of people. Afterwards were had a better understanding of how our research could be used to facilitate such a review session. We were also able to go out in the factory and observe shop employees assembling products. The complexity of the process, including workstation layout, tooling, material handling, scheduling, etc. was a rich environment for study. These meetings helped us understand the specific needs of industry so that we could prioritize our research to focus on the most pressing issues facing the assembly process planners. Broader impacts Throughout the grant period, several graduate and undergraduate students were involved in the research and outreach events. The research team demonstrated this research to several groups of 6-12th grade students, teachers, and parents from around Iowa and many industry visitors. We used the results of this research in our annual hands-on demonstration as part of the Iowa State University’s "Taking the Road Less Traveled" Career Conference for young girls across the state of Iowa. Undergraduates, supported by an NSF Research Experience for Undergraduates grant supplement, developed materials that explain how virtual reality can be used in every engineering discipline. A presentation and handout were prepared that introduce students to the various types of engineering careers, while at the same time highlighting the use of computing technology in engineering. Groups of students, parents and teachers came to the laboratory and were able to experience an immersive virtual environment during the Road Less Traveled Career Conference that was held annually in April and October. Summary This research provides insight into the use of immersive computing technologies, specifically those that include force feedback, in design decision making with respect to assembly methods planning.
