Practically every recent auto show has organized a concurrent autonomy/mobility conference where panelists drone on about sensor fusion, V2X communications, 5G networking, etc. These same auto shows feature concepts boldly predicting the future of Level 5 driverless transportation—employing some combination of front seats that swivel to face backward, windows that go opaque for privacy, and/or giant video screens that obscure the windows.
“Not so fast!” say human factors engineers. Build cars like that, and they’ll need to come equipped with barf bags.
A 2015 University of Michigan Transportation Research Institute report suggests that if passengers stop looking out the windows, 6 to 12 percent of adults will likely suffer moderate to severe motion sickness, also known as kinetosis. The report identified three likely triggers: conflicting signals between the motion we see and what we perceive with our inner ear, the inability to predict motion, and lack of control over our body’s motion.
Drivers seldom get carsick—they’re looking ahead, anticipating the need to turn or brake, and making the inputs that cause such motions. Because the driver is focused on driving, social norms suggest that passengers keep the driver company and pay attention to where the car is going, thus lowering the chances of kinetosis. But for passengers looking at books or screens while their peripheral vision sees stationary door panels and seat backs, these motions can be nauseating.
Now take the self-driving paradigm. If there is no driver and all the seats face the center, everybody is free to do what they like, such as fiddling with their screens. As a result, everyone in the vehicle will be more susceptible to motion sickness.
Kinetosis has long plagued engineers performing chassis development work on simulators, where perfectly synchronizing the video feed and the motion simulation can be problematic. Even a 20- to 40-millisecond mismatch can make susceptible folks revisit lunch. Motion sickness in such environments is known as Simulator Adaptation Syndrome (SAS). Ansible Motion Ltd. designs and develops simulators in Hethel, England. While working to stamp out SAS, it discovered that its high-precision six-axis simulators (used by three F1 teams) could also be programmed to study kinetosis in its newest driver-in-the-loop simulators. These realistic machines are designed for use not only by engineers and racing drivers but also by civilian subjects testing things such as driver interfaces.
Ansible’s technical liaison manager, Phil Morse, stresses that his company’s devices are simply tools that automakers will use to develop motion sickness countermeasures for autonomous vehicles. But he can already foresee some possibilities. “There could be some sort of auditory or visual cue provided to the occupants to warn them that the vehicle is about to turn or stop,” he says.
The Michigan study also suggested that visual stimuli projected around the edge of video screens could warn of vehicle motions, or the image could be synchronized to head movements like camera-image stabilization. Overall ride quality will always be somewhat dependent on the smoothness of the roads, but Morse also imagines that “like noise-canceling headphones, it’s conceivable that some degree of disturbance-canceling technology could become part of the occupant experience in cars of the future.” Perhaps using seat mounts that incorporate Ansible’s motion controllers?
Two more potential technological cures for riding the autonomous porcelain bus have shown promise. Wearing a Google Glass-like visor equipped with accelerometers can provide a peripheral horizon line to view when the actual horizon isn’t visible, and a NASA solution involves wearing LCD shutter glasses that black out four or eight times per second for 10 milliseconds at a time. There are also the tried-and-true treatments, such as Dramamine, ginger, sleeping, or closing one’s eyes. But imagine having to do that every time you got into a self-driving car. No thanks.
Recommendations for autonomous car design made by the authors of the Michigan study were simple: “Maximize the visual field with large windows, mount transparent video and work displays that require passengers to face forward, eliminate swivel seats, restrict head motion, and install fully reclining seats.”
Sorry, designers. Future autonomous interiors might end up looking pretty familiar to what’s already on the road.