Toyota probes self-driving safety issues

DETROIT — For decades, automakers have studied what happens to people inside cars when the vehicles crash with an alert driver behind the wheel.

But engineers are only beginning to understand how bodies might be flung around inside autonomous vehicles when the "driver" is checking email, watching TV or even sleeping.

The question matters because occupants of self-driving cars might need a host of new safety technologies to protect them.

Drivers and riders might not brace for impact or even be facing forward at all, if futuristic visions for self-driving lounge spaces come to fruition.

Toyota Motor Corp. just completed its biggest in-depth study of the matter, chronicling the body movements of people in simulated near crashes of autonomous vehicles.

Its conclusion: A lot more research is needed.

"We want to be able to offer improved technologies, based on what new postures might be present in a vehicle equipped with automated crash avoidance technologies," said Jason Hallman, the principal safety and crashworthiness engineer who led the one-year study.

"All we have is this hypothesis that maybe the posture would be different. We can't make any new technology or new design without knowing conclusively what we should be designing to," Hallman said. "But we don't know what that posture might be."

Toyota ran the study on 87 volunteers at the University of Michigan's Mcity autonomous driving testing ground in Ann Arbor from 2016 through 2017. It will release full findings in October at a conference of the Association for the Advancement of Automotive Medicine.

Volunteers spanned a wide range of body sizes and ages, from 18 to 65. They were driven around Mcity by a human standing in for a self-driving system under the guise of a comfort study. The unsuspecting subjects were told to sit in the passenger seat and then put through a regimen of extreme evasive safety maneuvers, such as sudden lane changes and severe braking. Toyota researchers measured how their bodies moved.

Results surprised Hallman's team. Researchers couldn't find a pattern in the way people's bodies reacted under the drastic driving conditions. Some braced themselves. Others just let the safety belt catch them. Some swayed this way; others leaned that way.

"We found a large variation," Hallman said. "Before this, everyone had assumed we had kind of figured it out, that we actually knew, or we could predict where you'd be in the seat."

Toyota's study was inconclusive, other than realizing the need for more study. Said Hallman: "So, what this has left us with is: Let's go back to the drawing board. Let's think a little more about this."

Future research could pinpoint what changes might be needed in seat belts, airbags or seat construction to keep people safe in autonomous vehicles, Toyota says.

Toyota's research is one of several programs underway at the Japanese carmaker's Collaborative Safety Research Center. Toyota established the U.S. auto safety research center in 2011 in response to the unintended acceleration crisis that led to the recall of millions of its cars. But over the years, it has expanded in size and scope.

Toyota says it will start planning a follow-up study on crash posture this year. The carmaker will listen to input from suppliers and customers in devising the next round.

"The suppliers of seats have ideas about zero-gravity seats that can twist in different angles and have footrests so that you're in a La-Z-Boy in your car," Hallman said.

Customers, meanwhile, say they want to use electronic devices, hold conversations or work while riding in an autonomous vehicle.

Another area ripe for research is motion sickness, Hallman said. That's an acute problem for people focused on email, videos or paperwork inside a moving vehicle.

"When you're focused on something that's not moving — inside of something that is, it seems to increase the risk of motion sickness," Hallman said. "That wild card causes me to pause in speculating about what might require additional consideration for crash protection."