Haptics of in-car radio buttons and its relationship with engineering parameters

The interaction with in-car interfaces is becoming complex and multidimensional due to the addition of more and more technologies and functionalities, which can have a negative impact on driving safety. The hand exploratory behavior of in-car interfaces has been studied aiming to minimize the mental overload of the driver when looking for radio functions. Also, the subjective and emotional values associated with the interface have been considered. However, the identification and translation of these needs into design specifications is problematic. The objective of this paper is to contribute to a better understanding of these issues by studying the relationships between users' preferences and engineering parameters of in-car radio buttons and, on the other hand, the identification of the more important engineering parameters for a better definition of the in-car interface requirements. The research was done based on an empirical study and the analysis combined exploratory statistics of preference ratings and qualitative content analysis, with partial least squares regressions and artificial neural networks to link the preferences with the buttons' engineering parameters. Relevance to industry: This paper proposes a set of haptic engineering parameters for in-car interface buttons in order to help the manufacturers and their clients to better define interface requirements related to subjective needs of the user, and so, with a positive impact on product development costs and delays. The developed methodology can be also used in other products. (C) 2017 Elsevier B.V. All rights reserved.