Reducing complexity of interaction with advanced bathroom lighting at home (Reduktion der Interaktionskomplexität bei hochentwickelten Badezimmerbeleuchtungssystemen für die Heimanwendung)

Developments in lighting technology provide a wide range of new opportunities for domestic use which have been demonstrated in several interior design projects. At the same time, available user interfaces providing full control over these systems are too cumbersome to use and are not acceptable for the majority of consumers. To reduce this complexity, we aimed at creating an intuitive user interface control for advanced multi-source lighting systems. Based on participatory design techniques, we invited end-users to help us design and evaluate the new interaction concept. In the final evaluation the user interface design was rated highly with regard to its perceived usefulness and ease of use . New designs for ad-vanced lighting systems should aim at user-friendly interfaces that make the transition from ordinary light switches to these new interfaces as simple and natural as possible. Zusammenfassung Die Entwicklungen in der Beleuchtungstechnik eröffnen zahlreiche neue Möglichkeiten für die Nutzung im Haushalt, was in vielen Innenarchitekturprojekten veranschaulicht wurde. Gleichzeitig sind aber die Benutzungsoberfläche, die zwar eine komplette Kontrolle über diese Systeme bieten, schwierig zu handhaben und für die Mehrheit der Benutzer nicht annehmbar. Zur Verringerung von Komplexität haben wir uns das Ziel gesetzt, eine intuitive Benutzungsoberfläche für moderne Multi-Source Lichtsysteme zu entwickeln. Basierend auf partizipativen Gestaltungsmethoden baten wir Benutzer, uns bei der Gestaltung zu unterstützen und das neue Interaktionskonzept zu bewerten. In der abschließenden Evaluation wurde die Gestaltung der Benutzungsoberfläche in Bezug auf die wahrgenommene Benutzbarkeit positiv eingeschätzt. Neue Gestaltungsmöglichkeiten moderner Lichtsysteme benötigen auf benutzerfreundliche Schnittstellen, die den Wechsel von herkömmlichen Lichtschaltern zu neuen Benutzungsoberflächen so leicht und natürlich wie möglich machen

Effects of resolution of lighting control systems

Advances in lighting technologies have spurred sophisticated lighting control systems (LCSs). To conserve energy and improve occupants’ wellbeing, LCSs have been integrated into sustainable buildings. However, the complexity of LCSs may lead to negative experiences and reduce the frequency of their use. One fundamental issue, which has not been systematically investigated, is the impact of control resolution (the smallest change produced by an LCS). In an ideal LCS, the resolution would be sufficiently fine for users to specify their desired lighting conditions, but the smallest change would be detectable. Thus, the design of optimal control systems requires a thorough understanding of the detectability and acceptability of differences in illuminance, luminance and colour. The control of colour is complicated by the range of interfaces that can be used to facilitate colour mixing. Four psychophysical experiments investigated the effect of LCS resolution. The first two experiments explored the effect of resolution in white light LCSs on usability and energy conservation. The results suggest that, in different applications, LCSs with resolutions between 14.8 % and 17.7 % (of illuminance) or 26.0 % and 32.5 % (of luminance) have the highest usability. The third experiment evaluated the usability of three colour channel control interfaces based on red, green, blue (RGB), hue, saturation, brightness (HSB) and opponent colour mixing systems. Although commonly used, the RGB interface was found to have the lowest usability. The fourth experiment explored the effect of hue resolution, saturation resolution and luminance resolution on the usability. Generally, middle range resolutions, which are approximately between three and five times the magnitude of the just noticeable difference (JND), for both hue and saturation were found to yield the greatest usability. The interaction between these three variables was characterised. Findings from this research provide a deeper understanding of the fundamental attribute of control resolution and can guide the development of useful and efficient lighting control systems