Safety

1-DIN aftermarket equipment for in-vehicle use has special challenges from the human machine interface (HMI) perspective. Development and sales of these systems is usually driven by cost. The face plate is limited in space. Displays are limited in size. The user group is very inhomogeneous. Competition between producers is hard, at stores aftermarket devices are presented parallel, so users choice will be influenced by the price and “at first sight”- attractivity. After all, the HMI design has to match safety criteria. The use of the systems on the road should be non-distractive, safe, fast, and easy. On the other side, additional functions beside traditional audio subsystems, like telephone, WAP applications, or navigation become more and more part of 1-DIN aftermarket devices. Latest systems are scalable, meaning, the user may add subsystems, following his own needs. In a study with 35 subjects, representing traditional user groups in age and gender, different versions of faceplates were rated. Results show smaller differences in human factors oriented items (readability, color coding, display size) but clear differences on the emotional side (“I like it”, “I would love to own it”, …). An expert-analysis of existing systems lead to the following suggestions: reduction of number of buttons, upsizing the display, allowing direct access to main functions, creating a flat menu tree, or using status information to keep the user up with information on were certain functions are etc. The graphic design of the system should meet the taste and the expectations of the targeted users. On basis of the study and the analysis solutions were developed.

Harman/Becker Automotive Systems GmbH, Filderstadt

Presented at the ITS America Annual Conference and Exposition, April 26 - 28, 2004 San Antonio, Texas