Wolfgang Krautter

An Evaluation of Input Controls for In-Car Interactions

The way drivers operate in-car systems is rapidly changing as traditional physical controls, such as buttons and dials, are being replaced by touchscreens and touch-sensing surfaces. This has the potential to increase driver distraction and error as controls may be harder to find and use. This paper presents an in-car, on the road driving study which examined three key types of input controls to investigate their effects: a physical dial, pressure-based input on a touch surface and touch input on a touchscreen. The physical dial and pressure-based input were also evaluated with and without haptic feedback. The study was conducted with users performing a list-based targeting task using the different controls while driving on public roads. Eye-gaze was recorded to measure distraction from the primary task of driving. The results showed that target accuracy was high across all input methods (greater than 94%). Pressure-based targeting was the slowest while directly tapping on the targets was the faster selection method. Pressure-based input also caused the largest number of glances towards to the touchscreen but the duration of each glance was shorter than directly touching the screen. Our study will enable designers to make more appropriate design choices for future in-car interactions.

Traffic simulation with ARTIST

The article describes a flexible traffic simulation environment ARTIST (Advanced Research Tool for Indoor Simulation of Traffic). The modeling and simulation styles are not hard-wired in the system, but can be expressed by the user. Thus, ARTIST can be used for a variety of simulation tasks, from the simulation of driver assistance systems to the lay-out of control strategies of traffic management systems. The architecture of the software will be described, together with some real-world applications.

HMI Strategy – Warnings and Interventions

One of the most important aims of driver assistance systems is the prevention of accidents. Onboard-sensors, algorithms, and other technologies allow developing strategies to achieve this, for example by warning drivers in critical situations. Depending on the remaining time, different driver reactions may have to be elicited. In some situations it may be sufficient to slow down well in advance or to change lanes. However, in other situations only an emergency braking or a fast evasive manoeuvre can prevent a collision. Since in most situations drivers are still in control of the car, the question arises of how to best support them in these kinds of situations. This encompasses two basic HMI aspects: (1) How can the required reactions be elicited in drivers, before the system has to intervene automatically due to the increased criticality and reduced time left? In such a very critical situation, (2) how can drivers be explained how and why the assistance system has taken over and intervened? Within the scope of the UR:BAN project, HMI concepts were developed and evaluated with regard to these aspects of intervention and warning strategies. The chapter gives an overview about the conducted studies and resulting HMI concepts.

An evaluation of the influence of haptic feedback on gaze behavior during in-car interaction with touch screens

A major motivation for the introduction of haptic feedback in in-vehicle touch screens is the reduction of the eyes-off-road time. This paper presents a study which compares different feedback conditions for touch screen interaction: (1) visual feedback, (2) combined visual-haptic feedback, and (3) haptic feedback only. Subjects had to select target buttons on a touch screen during simulated driving. Our results show that haptic feedback significantly reduces the eyes-off-road time and the subjectively perceived workload. When visual content is available, gazes on the touch screen are more frequent than necessary. And even in the absence of visual content, complete eyes-free interaction was only occasionally spotted, and subjects still looked at the screen initially. We assume that this is due to the necessity of an initial reference position.

Traffic Simulation for the Development of Traffic Management Systems

This paper describes the industrial application of traffic simulation at Robert Bosch GmbH. The role of traffic simulation in the design process of traffic management systems and the way of working of Bosch R&D are presented. The main features of Bosch’s simulation environment ARTIST (Advanced Research Tool for Indoor Simulation of Traffic) are described. Sample applications in the area of freeway management systems and urban traffic light control demonstrate how traffic simulation is currently used in the product development process. ARTIST’s flexibility allows the usage of domain specific traffic models that are best suited to the specific task.