High-strength steel: an independent ally

The technology required for autonomous driving usually depends on some common elements. For example, there are usually radars, cameras, LiDAR, and various other sensors. We have heard about advanced algorithms, adaptive learning and artificial intelligence, all of which are necessary for this promising new driving era.

Proponents say autonomous cars bring better infrastructure, reduced emissions, and the end of traffic fatalities. Massive events like the North American International Auto Show reflect just how far this technology, and its promises, have progressed.

It doesn’t seem like the future anymore because it’s already here.

Education & Utilization

Structural Integrity

Expect The Unexpected

Stable Paths & Bold Visions

Cost & Energy Consumption

Wings & Wheels

Education & Utilization

Without one of the longest-standing industries within the automotive landscape, this bold autonomous world would come to a screeching halt. Sure, we can easily associate a number of software applications with autonomous driving, but what about a raw material like steel? When we hear “driverless car,” steel probably does not come to mind, although maybe it should?

“For some reason, people understand that automobiles are new technology but they don’t understand that steel is a new technology too,” said Jody N. Hall, Ph.D., Vice President, Automotive Market, Steel Market Development Institute.

The Steel Market Development Institute represents steel companies and works closely with the automotive industry to provide the proper grades based on the application. The organization is also focused on educating the greater automotive industry on the uses and benefits of the material. ArcelorMittal, a multinational steel manufacturing corporation headquartered in Boulevard d’Avranches, Luxembourg, shares a similar vision. Blake Zuidema, Director of Automotive Product Applications, spends a great deal of time with the automakers.

“My team works with the OEM body structure design community to try and understand what kinds of material properties are required in order to achieve all of their design objectives,” he said.

Steel is widely utilized in the automotive industry, encompassing a significant portion of any given vehicle’s chassis, body, and overall structure. Full-size trucks from General Motors, RAM, and Ford, for example, employ a high-strength steel frame to accommodate heavy payloads. Other vehicles, from minivans to crossovers, use steel for occupant safety and enjoyable driving dynamics.

SMDI’s display at the 2017 North American International Auto Show at the Cobo Center in Detroit, Michigan. Pictured here is the new Chrysler Pacifica. The individual colors correspond to different materials, including their grades and properties, used to manufacture the vehicle. Photo: SMDI.

Structural Integrity

Part of the steel industry’s focus with autonomous driving is providing the designers of the technology a durable material that can be shaped around their components. The idea is that if the sensors associated with automated driving are protected, they are more effective.

“If we are able to give them a better performing material, then they can have a more efficient design,” Dr. Hall said. “You need some kind of structure to hold all of those sensors in place and a steel intensive one can better protect them.”

It’s not just protecting the sensors, however. Even in the era of driverless cars, occupant protection is still paramount. Indeed, one of the promises of autonomous driving is an accident free world, but perhaps those glasses are a little to rose colored?

“I would love to believe that when we move to autonomous vehicles that we will eliminate traffic accidents but the simple fact is that is not going to be 100 percent true,” Zuidema said. “I think we are going to dramatically reduce the number of traffic accidents but no technology is perfect.”

Zuidema points to both the commercial airline and shipping industries and how they run on automated and connected systems. Despite this, planes still crash and ships still sink.

“Sensors can fail or be occluded by the elements; driving conditions can deteriorate to the point where the sensors may tell the wheels to do something, but if there is no traction, the vehicle is basically a ballistic object,” Zuidema explained. “There is no reason to believe autonomous vehicles, despite the technology, are going to be free of accidents.”

SMDI, ArcelorMittal, and other advocates for steel believe autonomous cars will need passive safety features as much, if not more so, than active ones. Further to that, the future autonomous car needs to be programmed not only to understand the world around it – streets, road signs, traffic etc. – but to understand itself.

Expect The Unexpected

Let’s say an autonomous car encounters a runaway baby carriage and is, in this scenario, left with only two choices since stopping in time is not possible. One, it hits the baby carriage, or swerves to miss it, but will collide with some other object – wall, telephone pole, dump truck etc. – in other words, there is no promising end to this situation. If the car understands it has a very strong safety cage constructed from a very durable material, and highly engineered passive safety systems, that will impact its decision.

On the other hand, if the vehicle understands itself as having a safety cage of less integrity, and passive safety systems that are, from an engineering perspective, neglected, because we have put too much faith in the accident free promise of autonomy, then its decision could be very different. It may, in fact, hit the baby carriage.

“I realize this may be a stretch but these are the kinds of things you have to think about when it comes to autonomous vehicles,” Zuidema said. “When I think autonomous, I am still thinking the safety cage of the car is going to be equally important, if not more important.”

The three-point safety belt as it appeared in the Volvo PV 544 in 1959. According to the National Highway Traffic Safety Administration, seat belts saved nearly 13,000 lives in 2014. Photo: Volvo Car Corporation.

Stable Paths & Bold Visions

One of the most prominent examples of safety in the automotive industry is Volvo. Nils Bohlin, a Volvo engineer, is credited with the world’s first 3-point safety belt in 1959. The seat belt is arguably the greatest, most iconic passive safety device of all time, saving countless lives over the last near 60 years. This legacy is carried on through the automaker’s new Scalable Product Architecture (SPA), which utilizes hot formed steel and serves as framework for future Volvos.

“The use of hot-formed, Boron high-strength steel is a tradition for Volvo and provides several benefits in terms of safety and production,” said Jim Nichols, Technology and Product Communications Manager, Volvo Car USA LLC. “SPA allows us to add additional strength and rigidity to our cars while reducing weight and improving crash performance.”

Volvo’s vision is that by 2020 no one should be killed or seriously injured in a new Volvo. That’s a full five years before the general consensus on when autonomous cars are expected to be released.

“SPA gets us closer to this vision via additional high-strength steel and an electrical architecture that can support new safety technologies,” Nichols explained. “With the SPA platform, we were able to build both an electrical and network infrastructure that allows for the placement of additional sensors, which support autonomous driving technology.”

Dr. Hall believes such infrastructures are most effective when steel is in the picture.

“We want to deliver the structure of a vehicle that engineers can utilize to give good ride quality, durability, and safety performance,” she said. “However, today, we need to give the sensors for autonomous technology a pathway, and so we design the shape of the steel accordingly.”

Volvo’s belief in autonomous driving is well publicized and they have, in recent times, championed it with much vigor. And while SPA will, with its electrical and network infrastructure, support the technology necessary for autonomous driving, the basis is still on durability and safety.

“Thirty percent of the XC90 architecture, for example, is made from Boron steel, which is among the strongest materials available today,” Nichols said. “This material mix allows us to deflect and absorb crash forces, keeping drivers and passengers safer.”

A Volvo XC60 endures a frontal crash test at 35 mph. Photo: Volvo Car Corporation.

Cost & Energy Consumption

In addition to safety is cost, another concern consumers will inevitably have when faced with an autonomous car. One school of thought suggests going with an aluminum or carbon fiber intensive body to cut weight and therefore, reduce the number of batteries. Since battery and electric powertrains are often associated with autonomous vehicles, steel proponents are implementing strategies accordingly.

“In the past, batteries were very expensive and if you could reduce the number of batteries you needed for a given range of performance, you could reduce the cost of the car,” Zuidema said. “What we see now is the cost of batteries coming down – the marginal costs are such that it is cheaper to make the vehicle a little bit heavier out of steel, and even though you will need slightly more battery storage, the cost of the batteries is nowhere near the cost of converting to aluminum or carbon fiber.”

Steel advocates also point to the environmental benefits during manufacturing, especially as autonomous cars have the potential to reduce emissions themselves. Manufacturing an automobile from steel requires less electricity and CO2, thereby generating a smaller carbon footprint.

“Steel by its very nature requires far less energy during the production phase than other materials like aluminum,” Zuidema explained. “It takes a lot more energy to take aluminum oxide and convert it into pure aluminum metal than it does to take iron oxide and turn it into pure iron.”

General Motors is now testing autonomous technology in Michigan. The Chevy Bolt EVs for the tests feature advanced autonomous systems, along with other hardware designed for occupant safety, like ten standard airbags. The new Chevy Bolt EV utilizes high-strength steel extensively throughout its body structure for additional safety. Photo: General Motors.

Wings & Wheels

While some automakers predict as early as 2021, it’s hard to say just what the autonomous market will become once the vehicles arrive. My emotions on autonomous driving are mixed, although that was not always the case. When I first learned about it, and when we first began covering it here for Automoblog, I was all for it. Today, I am not so sure, but I want to believe in the autonomous car and I will give it a chance. I want to believe the forthcoming autonomous automotive system will give us all the benefits it promises and more.

Imagine a world free of accidents with better infrastructure and reduced emissions.

It’s nothing short of awesome.

However, I am not willing to give up my seat belt for the autonomous automotive system. I am not willing to give up the usage of high-strength steels either that keep us safe during a collision. I will give autonomy a chance but I won’t give it my entire blind faith. Neither should you.

Even though airplanes are the safest form of travel, I still buckle up when I board, and am mindful the nearest exit might be behind me. I even stay awake for the safety presentation. Like we often do with wings in the sky, we take for granted the basics that keep us safe. We should not replicate this with our wheels on the ground, autonomous or otherwise. Our faith in the autonomous system is best predicated upon the understanding of why the modern sensor needs the proven material, and why, for the sake of all the promises of autonomy, they must work in tandem.

Carl Anthony is the executive editor of Automoblog and lives in Detroit, Michigan.