Nice writeup by BimmerFile on the iDrive, a single-button input device for the non-driving functions of the BMW. I’ve excerpted my favorite portions below — specifically their connection of iDrive design to the proximity-compatibility principle and the principles of importance and frequency of use.
BimmerFile was recently invited to Munich and into the very secret BMW labs that birthed the original HMI interface known as iDrive. There we sat down with Dr. Bernarhd Neidermaier, Head of Human Interface at BMW to talk about iDrive, the concept, and testing behind the ideas we see in modern BMWs.
As Dr. Neidermaier explained, it all starts with the study of driver distraction. In fact, it’s an idea that BMW has been studying closely since the mid 1990′s. In recent year,s BMW has moved to using eye tracking technology to better quantify what it really means to take your eyes off the road in order to interact with technology. With a special rig that consists of tiny camera attached to glasses (focusing on the eye) and another focusing on what the driver looks at, the eye-tracking process allows BMW to calculate the exact time it takes to perform any function within the car.
Finally BMW has found that controls should be located downwards (towards the center console) so the driver can operate them without having to lift their shoulder from the seat. According to BMW engineers, if your shoulder lifts and you have your seat properly adjusted the HMI design isn’t optimal. As you can see in the photo below all modern BMW’s (in this case an F10 5 Series) have been following both of these philosophies that were initially established with the E65 7 Series in 2001.
Furthermore, those functions that are needed for driving must be situated directly in front of the driver. It sounds obvious but there have been many examples over the years of driving related displays pushed towards the center. In the case of the MINI, the center speedometer. Although BMW made sure to give the driver a digital speed read-out in the tachometer directly in front of them. Without it, BMW’s smallest car would fail their own usability testing.
Based on the research a driver’s information goes from center to the sides in order of importance. That means the tertiary stuff like oil temp etc. should be well out of the way of the speed and engine RPMs.
There is also a publication of this process available through the ACM Library.
Niedermaier, B., Durach, S., Eckstein, L., & Keinath, A.(2009). The new BMW iDrive – Applied processes and methods to assure high usability. ICDHM ’09 Proceedings of the 2nd International Conference on Digital Human Modeling: Held as Part of HCI International 2009.
Photo credit _benj_ at Flickr (I could not find any creative commons pictures of the 2011 iDrive, so this is older. Pictures are available in the linked article, however.)
Also, check out the DESIGNING*for humans blog section on Control & Display Design.