Toyota brings a generative design seat frame to the next level with AI

The art of balancing the design, safety, and comfort of automobiles involves a lot of complexity—especially when it comes to adding more space to a finite area. Toyota is responding to the market demand to free up more room in the cabin by creating thinner and lighter seats.

“While the current seat frame is designed to meet the strength requirement with trusted manufacturability, it is difficult to make it thinner,” says Shinsuke Omori, project manager in the Interior Design Department, Vision Design Division at Toyota Motor Corporation. “Designers do not usually work on the seat frame itself, but rather add materials to it, and that’s the restriction.”

But Omori’s design team can explore the ideal shapes and features for seats without caring about the current shape of showroom car frames. “This time, we wanted to design a new frame that can impact and also connect to commercial cars in the near future, even though it’s still an advanced development,” Omori says. “If the designers think it is not feasible, this project is just for advanced development. So we needed to make it feasible to some extent.”

Many requirements must be met for seats in fast-moving vehicles; at the top of the list is securing occupants’ safety and comfort. Weight reduction and sustainability also make this task more complex. “What we are focusing on right now is the balance between comfort, sustainability, weight reduction, and design,” Omori says.

Generative design, a technology based on artificial intelligence (AI) that is available in Autodesk Fusion 360, makes a good fit for this balancing act. “When I realized that generative design was being used in race car suspensions, I thought it was interesting,” Omori says. “The fact that it could come up with shapes that human designers would never have thought of, yet the requirements are met, so the cars are light and strong. I thought we could make it ancient yet modern—cherry-picking by balancing structure designers would not have drawn with a solid background that meets all the requirements we need.”

Designing the new seat frame began with developing a concept to secure more space in the cabin. The usual rectangular-shaped seat frame has a flat structure, but the designers tested the idea of optimizing the frame by bringing the core structure to the center. For passengers in the rear seats, a thick, wall-like seat in front of them makes the space feel smaller, so the team tried to make the excluded area larger to secure a wider space in front of their legs.

Automobile seat safety is essential, and the seat frame must have high strength and rigidity. In the event of a collision, occupants move with great force, seatbelts are pulled, and strong forces apply to certain areas from different directions. In some cases, people in the back seat may hit the front seat.

After inputting these requirements, the generative design’s output “is often completely unexpected at first,” Omori says. “But we took it further and made slight modifications as we went along. There were cases where the proportions and balance didn’t look beautiful at first in the output, so we intentionally tried to shift the design to a certain direction by making slight adjustments to excluded areas.

“There is always a trade-off between what a designer wants to do and what generative design creates,” he continues. “For instance, manipulating ratio or balance will lead to issues in dynamics or increases in weight.” It took three to four months to complete the design, and Omori worked closely with Satoshi Yanagisawa of Triple Bottom Line to complete the calculations.

“It’s fun to see the various patterns of shapes designers don’t think of,” Omori says. “It never ceases to fascinate me. It is surprising and interesting to see how small differences can result in completely different shapes, and I think this is one of the advantages of generative design.” But to make lightweight products, you also need knowledge of the related areas and materials. With all of these inputs, it’s possible to reduce a specific part’s weight. The team is now working collaboratively with in-house engineers to develop a new design using generative design.

Omori says the team is designing the seat frame with the possibility in mind of installing it in a production vehicle. Creating this seat frame requires 3D printing, which increases the cost. As current seat frames are made efficiently with established manufacturing methods, they need further study of ways to produce the frame with press manufacturing while also incorporating generative-design concepts. “As we have gained a lot of knowledge from this project, I think there are possibilities to make it happen,” he says.

According to Omori, the value proposition of press manufacturing for mass production may be changing for future cars. “Today’s seats are made with the idea of the greatest common denominator to accommodate various body sizes, and it’s difficult to make something optimal and comfortable for all people,” he says.

With this type of new design, it might be possible to keep the spine of the seat the same for various seat sizes and then make the rest to fit the user’s physique using a 3D printer, for example. The current seats are made of completely different materials, such as metal frames, urethane, and leather, but Omori says it could be possible to challenge mono-materials with generative design.

This kind of design would be easier to realize if it is first used for a limited purpose, he says: “For example, if we limit it to low-speed mobility, we can lower the requirements. If there is a special environment where speed is automatically controlled, I think we could start with that as a first step and gradually expand to ordinary vehicles.”

Toyota is actively experimenting with AI-based tools, including generative design, for its design pipeline. “We are very free to do that here,” Omori says. “Within the same department, we do design and planning for things that have nothing to do with cars. It’s important to be stimulated by other departments and such. These tools will change our focus in the future, and the basic concept will become more important. The tools will become more and more powerful, but we need to sharpen our focus on what kind of form we want to create—and what is the intention, meaning, and function behind that form—in order to differentiate ourselves.

“It’s important to create simple, beautiful, and straightforward products that are easy to use and have the functions customers want,” he continues. “To this end, I think it is crucial to first decide what you want to do and clarify the direction and concept you want to take as Toyota Design, rather than being used by the tool. As long as the tool fits that concept, I will use everything available to create the best possible product.”