Safe state - If a driver is not used to driving anymore; can he/she be trusted with the steering wheel when the car fails?
- July 9, 2015
- Marcel Romijn
With the steps taken and to be taken in driver assistance systems the driving experience is changing. Anyone that receives their driving permit today will likely be used to vehicles that support and sometimes overrule.
As even older vehicles are broadly available with ABS, Traction control and Stability systems the newer drivers do not know anymore how to drive without these assisting systems. Still when there is a failure in these systems they tend to shutoff (safe-state) and mimic the behavior of a classic car without these systems onboard. No problem for the driver with years of experience that received his/her driving permit in the time that these guardian angels did not exist yet. A very scary experience the least for a novice driver.
With adaptive cruise control systems, advanced lane keeping aids and crash avoidance technologies the driver of a vehicle today equipped with these systems will drive with the knowledge that if he/she makes a mistake the car will at least attempt to correct the mistake. With self-driving vehicles the responsibility will even be the other way around; the car is driving and the driver is monitoring at best.
When we look at commercial airplanes you can see that today's pilots only fly themselves for a few minutes of the flight time. The airplane's advanced automatic pilot is capable of flying the airplane on its own. Including take-off, landing and taxiing. Most of the time a pilot is just there to monitor the auto-pilot function. While that would seem to be the safest scenario many airline accidents have proven it has some downsides. In these accidents some minor event causes the auto-pilot function to shut-off. The pilots that suddenly are forced to actively step into a situation should be able to cope with taking over control. However as they only fly an airplane themselves rarely they have lost their feel of flying, the feel of response to their commands etc. Young pilots do not get much chance to build up these skills but older pilots are slowly losing their skill. Currently the FAA (US Federal Aviation Administration) is advising airlines and pilots to practice again more with flying manually to keep the skill levels at such levels that the pilot can takeover when the auto-pilot is switched off.
Automotive driving skill such as prevention of oversteer or understeer is rapidly declining. Stability control is there to save and support the driver. And for such scenario's that is in general a good thing. Few drivers were ever able to hone their skills often enough to prevent and recover from oversteer or understeer.
Currently however the driver assistance systems have taken over more of the driver responsibilities. This comfort enhancing also takes a responsibility off the driver’s shoulders. And when used often enough it takes away the skill of rapidly identifying and responding to a dangerous scenario. In short; can we still trust the driver to have driving skills at sufficient levels?
At BRACE Automotive we are far from neural or social scientists. We are automotive engineers. Still we must understand this issue. When for example a radar system is not functional (due to failures or even just due to weather conditions) the burden is back on the driver. If the driver can not handle this burden a switch off for the system is not an acceptable safe state. A reduced level of performance could be acceptable. This requires advanced limp-home type of back-up scenarios.
So in short: The definition of what an acceptable safe-state is is changing along with every step towards autonomous driving. The design requirements of automotive systems are therefore changing as well.