Die vorliegende Arbeit widmet sich dem Einsatz von Lenkradvibrationen zur Informationsübermittlung an der Schnittstelle zwischen Fahrzeug und Fahrer unter Berücksichtigung physiologischer und psychologischer Aspekte. Als besondere Eigenschaft wird die Möglichkeit zur Erzeugung örtlich aufgelöster Vibrationen erkannt. Damit ist es möglich, über einseitige Lenkradvibrationen Richtungsinformationen an Fahrer zu kommunizieren. In drei Hauptstudien werden mit insgesamt 150 Probanden verschiedene Aspekte der Fahrerreaktion auf einseitige Lenkradvibrationen untersucht. Zunächst wird in einem grundlegenden Laborexperiment die intuitive Reaktion auf einseitige Lenkradvibrationen ermittelt. Im Anschluss wird die subjektive Präferenz der einseitigen Lenkradvibration in der Anwendung als Spurverlassenswarnsignal nachgewiesen. Zuletzt wird der Versuch unternommen, die einseitige Lenkradvibration zur Initiierung einer Ausweichreaktion in einer drohenden Frontalkollisionssituation einzusetzen.
In this work applications of steering wheel vibrations are discussed. Tactile excitations that are perceived with mechanosensors in the skin of the human palm are explicitly focussed to differentiate from the state of the art. Because of the compatibility of the location of stimulus and response, haptic signals at the steering wheel are advantageously utilized to influence lateral vehicle guidance. The thesis summarizes findings of the psychophysical perception of tactile steering wheel vibrations and supplements these findings with new insights on the effect of variations in specific stimulus parameters on the perceived intensity and interpretation of messages transfered by vibrations at the steering wheel. A peculiar feature of vibro-tactile stimulation is the possibility to produce spatially distributed vibrations, which allows for communication of information on direction to the driver. Based on a review of the literature, a subjective preference of lane departure warning signals relying on vibro-tactile excitation and comprising information on directionality is hypothesized. This thesis therefore focusses on single-sided steering wheel vibrations. A single-sided vibro-tactile stimulation is assumed to be semantically associated with the rumble phenomenon induced in case of lane deparuture, thus facilitating the interpretation of the warning signal and leading to an enhancement of driver reactions when utilized as a lane departure warning signal. Three main studies examining a total of 150 subjects were conducted to reveal specific aspects of driver reactions towards single-sided steering wheel vibrations. First of all, a fundamental laboratory study examined intuitive reactions on single-sided steering wheel vibrations, legitimizing the stimulus-response mapping necessary to utilize this kind of signal as a lane departure warning signal. The second study confirmed the subjective predominance of the single-sided vibration as a lane departure warning signal when comparing this signal to alternative haptic warning signals at the steering wheel that were previously optimized for this application. In a final step, the third study examined the possible application of the single-sided steering wheel vibration to initiate an evasive steering reaction in case of an imminent forward collision situation Based on the results of the experimental studies conducted in this work, the utilization of the single-sided steering wheel vibration as a lane departure warning signal is strongly recommended. The signal both transfers the reason for the warning and recommends an action in a discrete and unintrusive manner. Any further application of the single-sided vibration, particularly the advice on a steering reaction in a collision situation, which was originally favored, can not be supported based on the present work.