The NRC's precise and rapid dieless forming method of aluminum sheet metal for vehicle components
Two industrial robots at the National Research Council of Canada (NRC) work in harmony to form complex vehicle parts. In a recent project led by the NRC’s METALTec industrial group, NRC experts used their unique capabilities in digital manufacturing and cooperating robots to show that this type of synchronized collaboration is also key to innovation.
When snowmobile manufacturer Bombardier Recreational Products (BRP) wanted to speed up the production of custom aluminum parts, they turned to researchers at the National Research Council of Canada (NRC) to find an effective and faster way to shape aluminum prototypes at a lower cost. BRP and one of its part manufacturers, Verbom, which are both METALTec members, had been using traditional methods to produce vehicle parts for a long time, but they were looking for an engineering solution to improve their manufacturing processes and overall products. Keen to help the 2 companies achieve this goal, experts from the NRC were able to accomplish this using their extensive knowledge in aluminum forming and incremental sheet forming (ISF), a technique that uses computer-aided design (CAD) to form sheets into a final shape through a series of small incremental deformations.
"We were looking at lightening the weight of snowmobiles by making better use of aluminum sheets," says Gilbert Lefrançois, a mechanical project engineer at BRP. "We also support snowmobile competitions and races, which need special parts and constant improvements." He expects that, in the future, the technique can be rolled out to other products such as boats, motorcycles and personal watercraft. "The turnaround and cost savings that the ISF transformation offers is very important because we need new parts almost every day," he adds.
The NRC team's proposal to meet BRP's requirements and in a cost-effective way won the company's respect—and business. Lefrançois explains that, while researching possibilities for this task, he found other options, but they required investing millions of dollars in large, dedicated machines. "The NRC's proposal was very clever because it leveraged BRP's existing industrial robots," he says.
First prototype from the NRC's dual-robot system
Both the NRC's Automotive and Surface Transportation Centre (NRC AST) and Aerospace Research Centre (NRC AERO) brought a remarkable blend of expertise to the table: some of the NRC's researchers have expertise in numerical simulations and others are experts in robotics and mechatronics. In addition, the project was supported technically and financially by industrial members from the METALTec industrial R&D group, which provided ongoing direction on the needs of the industry. "The synergy between our teams was critical for the success of this project," says Vincent Raymond, a research officer at the Automotive and Surface Transportation Research Centre.
"We had to learn a lot from the process side of sheet forming and had to communicate adequately our roboticist point of view to our collaborator, which was beneficial for everyone at the end of the day," says Gabriel Côté, a robotics research officer at the Aerospace Manufacturing Technology Centre (AMTC).
For the first phase of this project, they successfully developed and implemented a robotic cell to use ISF for dieless forming of advanced sheet metal components. "At the NRC, we have an edge in how to control these robots and make them more precise under high-process loads," explains Bruno Monsarrat, who leads the robotics team at NRC AERO. "Since 2016, researchers from the Aerospace Manufacturing Technologies Centre's (AMTC) robotics team have formulated patents, invention reports and software copyrights to improve the accuracy of robots under process loads. The goal for precision in this first phase of the project was to be within +/- 1 mm during the process of incrementally forming complex parts with cooperating robots, a significant result considering the level of force applied on the robots during this process."
Jean Savoie, Senior Research Officer at NRC AST, points out that, despite the team's talent and resources, there were a lot of research and development technology challenges prior to being able to successfully demonstrate this ISF cell concept with 2 synchronized robots in the AMTC facility. The NRC team found the path to success very challenging. However, they ultimately overcame the numerous obstacles by leveraging NRC intellectual property and identifying possible areas for further research.
In the end, team members demonstrated that their innovations in rapid prototyping would eventually allow BRP to meet its customer requirements and significantly speed up the process. "The traditional die-based process to create moulds can take up to 6 months," says Savoie. "Going from CAD to a part cut that down to a week or two."
After successfully completing the prototyping phase, the researchers are gearing up for further development. "The challenge remains that the level of expertise needed to be able to use this technology in industry is still too high," says Raymond. "Before we can deliver the technology, we have to make it more user-friendly." The next phase will examine technology transfer and the steps needed to facilitate this process, namely achieving a higher technology readiness level, a measure of the maturity level of a technology, in order to allow a successful deployment in an operational environment.
"The challenges brought by industry allow us to push the boundaries of traditional manufacturing processes and develop technologies that can not only be used to solve a single problem but also be adapted to various applications and industries. Collaboration with other government agencies, industry and academia is key to developing relevant and sustainable R&D innovations that will have an impact for many years," concludes Monsarrat.