Understanding these different levels is clouded by driver expectations of this scale, and drivers might wonder if there are increments along the way. After all, some carmakers describe Level x.5 or Level x-plus functions—but the SAE J3016 specifications do not provide for these incremental increases. A vehicle’s ADAS system provides a defined level of assistance, or it does not. SAE has trademarked its levels, which might help rein in abuse of the terms.
But even if so, consumers could still misunderstand the assistance provided by the various levels just because the numerical system is inherently hierarchical even though the levels themselves might not be, depending on the execution. For example, a local taxi that features Level 4 automation is not lower in capability than some eventual Level 5 fully autonomous car. The taxi might be a top-notch execution of Level 4 capabilities. Is a self-driving car with Level 5 technology that is poorly executed and prone to mistakes better?
“This has the implication that the higher the level, then the better, or more advanced the automated system is,” said Mahmood Hikmet, PhD, head of research and development at New Zealand automated shuttle company Ohmio in a YouTube video series on autonomous technology.
“But that’s not true. The only thing SAE J3016 levels tell you about a system is about the responsibilities of the human or the automated system while executing the driving task,” he continued. “That’s it. Nothing about the operational design domain, capabilities of the system, or how advanced the systems are. Just what the human and the automated system are respectively responsible for doing during operation.”
SAE categorizes Levels 0-2 as driver-support features. Levels 3-5 are automated driving features.
As driver-support features, Levels 0-2 mean that the driver is always responsible for piloting the car, even in those circumstances when the system might operate the steering, brakes, and accelerator. The driver must constantly monitor these features and steer, brake, and accelerate as needed for safe operation of the vehicle.
For Levels 3-5, the person sitting in the driver’s seat is not driving the car—the automated system is, if it is engaged. But this can be tricky. Phillip Koopman, an electrical engineering professor at Carnegie Mellon University, points out on his autonomous vehicle blog that a vehicle’s Level 3 system may not notify the driver when human intervention is needed, as we’ve already seen from videos of people wrenching steering control from Tesla’s ostensibly Level-2 Full Self Driving beta system when it attempts to steer the car into danger.
This is why, Koopman adds, that the driver in vehicles with Level 3 systems activated cannot perform non-driving activities, such as napping or watching a video. “J3016 does not say that Level 3 means ‘eyes off road’ anywhere,” he emphasizes.
Source : https://www.popsci.com/technology/autonomous-vehicles-explained/
