While the increasing requirements for HMI between SAE Level 1 and 2 were (relatively) gradual, Level 3 will be a huge step for vehicle manufacturers. Humans are adaptable, and can generally work around poor controls and instructions. But, when a Level 3 vehicle is fully in control, it is no longer the driver that needs to adapt to the limitations of the vehicle. The vehicle needs to adapt to the limitations of its driver. Any driver. If the vehicle decides it needs to hand over control to the driver, it must be capable of conveying that quickly and clearly. The driver may not be paying attention, so an audio-warning? But that would not work for deaf drivers. Perhaps change the display color instead? Difficult for the 5 percent of the population who are color-blind ...and many of them don't know they are color-blind. Clearly, this won't be easy.
Achieving an effective HMI at Level 3 will be considerably more difficult than in the current Level 1 & 2 vehicles, so it's worrying that so many mistakes are still being made right now. For example...
Systems that do not indicate which lane marking is being tracked (left or right side).
Requiring drivers to change their LDW system settings through an infotainment menu, resulting in a high 'eyes-off-road' time.
No audio-prioritization for ADAS warnings, so music will continue to play while audio-warnings are being given to the driver.
No dedicated HMI space for ADAS warnings in the instrument cluster.
No automatic cancellation of systems, such as ACC, when the driver unbuckles their seatbelt, or even when the driver's door is opened.
experience in benchmarking ADAS HMI implementations for SAE Levels 0, 1 and 2
has highlighted a number of recurring issues, including a lack of consistency in HMI strategy, system status not always being visible, incorrect prioritization or confusing presentation of information. Many
of these issues are due to ADAS being designed in a piecemeal
manner - often without an overall approach and strategy - especially in terms of
interactions with other vehicle systems (such as navigation). This
approach is no longer feasible, especially when delivering higher levels of
In order to
remedy this situation, SBD recommends the following approach for
SAE Level 0-2
It's easy to think that the driver taking back control of the vehicle is the end of the take-over, but it continues long after that. The driver needs to take in their immediate surroundings, the situation at hand, and then react accordingly. Depending on their level of attention when they took control, it is estimated that it could take up tp 40 seconds for a driver to be fully, safely back in control (i.e. transition time). Unfortunately, a driver monitoring system alone cannot measure all of the variables affecting the driver's take-over performance.
“OEMs can no-longer ignore the outliers” says Dr. Alain Dunoyer,
Head of Autonomous at SBD Automotive. “Where traditionally, HMI
could be designed for 80% of users, as we move to SAE Level 3 and HMI becomes safety-critical, the systems will
need to be able to work for all users. This requires cohesive strategies, large amounts of research, and both internal and external benchmarking. But, the OEMs that get it right will have a significant head-start in the future of the autonomous automotive industry."