Investigation of Thermal Stimuli for Lane Changes

Haptic feedback has been widely studied for in-car interactions. However, most of this research has used vibrotactile cues. This paper presents two studies that examine novel thermal feedback for navigation during simulated driving for a lane change task. In the first, we compare the distraction and time differences of audio and thermal feedback. The results show that the presentation of thermal stimuli does not increase lane deviation, but the time needed to complete a lane change increased by 1.82 seconds. In the second study, the influence of variable changes of thermal stimuli on the lane change task performance was tested. We found that the same stimulus design for warm and cold temperatures does not always elicit the same results. Furthermore, variable alterations can have different effects on specified tasks. This suggests that the design of thermal stimuli is highly dependent on what task result should be maximized

Haptic Feedback for the Transfer of Control in Autonomous Vehicles

Vehicles offering autonomous features need effective methods for transferring the control from the driver to the vehicle and back. While most research focuses on presenting information the driver might need after retaking control, our study investigates ways to improve the process of transferring control itself. We investigated multimodal feedback with and without haptics and visuals in a simulator study. Results showed that visual and haptic feedback improved driving during handover. Subjective ratings described multimodal feedback without visual as more disruptive than with the visual feedback included. Furthermore, ratings showed a preference for including visual and haptic feedback. These results lead us a step closer to a safe, clear and accepted control transfer process between driver and vehicle

Purring Wheel: Thermal and Vibrotactile Notifications on the Steering Wheel

Haptic feedback can improve safety and driving behaviour. While vibration has been widely studied, other haptic modalities have been neglected. To address this, we present two studies investigating the use of uni- and bimodal vibrotactile and thermal cues on the steering wheel. First, notifications with three levels of urgency were subjectively rated and then identified during simulated driving. Bimodal feedback showed an increased identification time over unimodal vibrotactile cues. Thermal feedback was consistently rated less urgent, showing its suitability for less time critical notifications, where vibration would be unnecessarily attention-grabbing. The second study investigated more complex thermal and bimodal haptic notifications comprised of two different types of information (Nature and Importance of incoming message). Results showed that both modalities could be identified with high recognition rates of up to 92% for both and up to 99% for a single type, opening up a novel design space for haptic in-car feedback

Investigating perceptual congruence between information and sensory parameters in auditory and vibrotactile displays

A fundamental interaction between a computer and its user(s) is the transmission of information between the two and there are many situations where it is necessary for this interaction to occur non-visually, such as using sound or vibration. To design successful interactions in these modalities, it is necessary to understand how users perceive mappings between information and acoustic or vibration parameters, so that these parameters can be designed such that they are perceived as congruent. This thesis investigates several data-sound and data-vibration mappings by using psychophysical scaling to understand how users perceive the mappings. It also investigates the impact that using these methods during design has when they are integrated into an auditory or vibrotactile display. To investigate acoustic parameters that may provide more perceptually congruent data-sound mappings, Experiments 1 and 2 explored several psychoacoustic parameters for use in a mapping. These studies found that applying amplitude modulation — or roughness — to a signal, or applying broadband noise to it resulted in performance which were similar to conducting the task visually. Experiments 3 and 4 used scaling methods to map how a user perceived a change in an information parameter, for a given change in an acoustic or vibrotactile parameter. Experiment 3 showed that increases in acoustic parameters that are generally considered undesirable in music were perceived as congruent with information parameters with negative valence such as stress or danger. Experiment 4 found that data-vibration mappings were more generalised — a given increase in a vibrotactile parameter was almost always perceived as an increase in an information parameter — regardless of the valence of the information parameter. Experiments 5 and 6 investigated the impact that using results from the scaling methods used in Experiments 3 and 4 had on users' performance when using an auditory or vibrotactile display. These experiments also explored the impact that the complexity of the context which the display was placed had on user performance. These studies found that using mappings based on scaling results did not significantly impact user's performance with a simple auditory display, but it did reduce response times in a more complex use-case

Opportunities for olfactory interaction in an automotive context

Driving is a highly visual task. Nevertheless, it is a process that involves other senses as well. When we drive, we touch the steering wheel; we listen to what is happening around us, and, even if we are not paying attention to that, we smell what is happening with the car or around it. A scent of gasoline, the burning rubber, the plastic heated up by the sunlight - these are just a few examples. Smell is a very important sense for driving, though it has not been studied much in this context [85], despite being able to provide a much more vivid experience than any other human sense [80]. This thesis aims to fill this gap by investigating opportunities for olfactory interaction in an automotive context. The thesis is mainly focused on designing a scent-delivery device suitable for in-car interaction, on the topic of delivering driving-relevant notifications using scents, and on studying the effects scents have on the driving performance and behaviour, as well as the driver’s mood and well-being. This paper-style PhD thesis consists of two parts. Part II is a collection of seven published papers written in the scope of this thesis, and Part I describes how these papers build a coherent story. Part I starts with an introduction (see Chapter 1) that covers the research questions and contributions of the thesis. It continues with a summary of the background research (see Chapter 2). This overview part then moves on to the description of the approach (see Chapter 3) that covers the process of designing the scent delivery device, the olfactory interaction space, and the studies conducted throughout this PhD. Chapter 4 then summarises the core findings of each study, which are finally discussed in Chapter 5. Part I finishes with a conclusion (see Chapter 6)