Situation Adaptation: Information Acquisition, Human Behavior and its Determining Abilities

The goal of the dissertation was to acquire knowledge (1) about the way of how information in the environment is processed by an observer, (2) about the interaction between the processed information and the behavior of the observer, (3) about the role of the familiarity of the environment and (4) about the abilities determining the information acquisition and human behavior in environments, which novelty decreases. For this purpose, a theoretical basis was provided discussing a continuum of information acquisition starting from direct perception and ending with higher cognitive processes such as decision making and problem solving and a continuum of human behavior from exploratory, creative expressive behavior to direct activities, which no longer require information processing. Cognitive processes have been discussed underlying these continui, on which basis abilities of the human being and characteristics of the situation have been determined which were expected to influence the adaptation process, which is reflected by moving from the one end of the continuum requiring a high level of information processing to the other end. A study was conducted at the Evangelische Stiftung Volmarstein to test major assumptions underlying these theoretical assumptions. For this purpose, 16 physically disabled wheelchair users repeatedly executed unknown (gardening) tasks in for them unfamiliar environments. While executing these gardening tasks, their gaze behavior and their operations, actions, and activities were recorded. To test the influence of the individual differences on the adaptation process, the intelligence and the motor abilities of the participants were assessed on the basis of carefully selected tests. The hypotheses testing the cognitive processes proposed for situation adaptation for information acquisition and human behavior and testing the impact of the individual differences on the situation adaptation process have been analysed with general linear model analyses, polynomial tests and stability analyses. The results have first confirmed the theoretically discussed cognitive processes underlying the continui of information acquisition and human behavior: Initially, when being confronted with a new situation, a cognitive or internal representation of the environment is built, which enables mentally simulating different sets of actions to achieve the goal in question. For this purpose, proximal variables are perceived and exploratory behavior is executed by the human being. After having built this internal representation and after having tested different ways of achieving a goal, the information in the environment is specified, which points to an action to achieve the goal in a given situation. The gaze durations on this anchor are prolonged. On the behavioral side of the adaptation process, it is characterized by a clustering of operations to actions. When the situation is familiar, behavior and eye movements are aligned: Anticipatory behavior decreases, operation-independent gazes occur to update the internal representation, and operation-relevant gazes are executed to get feedback on the progress of the currently undertaken operation. The impact of the individual differences on the adaptation process has also been supported: The predictive validity of intelligence on the adaptation process has been demonstrated especially regarding the duration of the eye movements and the human behavior (i.e., average duration of operations); however, an influence on the actual course (e.g., the total number of gazes executed or the number of the task-related gazes) has not been revealed, except regarding the number of strategic changes performed. This number of strategic changes in human behavior is further influenced by the psychomotor abilities, which also determine the individual differences regarding the number and the duration of the operation-independent gazes. For all three effects, a theoretical, indirect effect has been proposed: It is for the participants with lower psychomotor abilities more important to determine the best solution of achieving the goal in comparison with the participants with greater ability levels. Further, the participants with greater psychomotor abilities have less time for executing (long) operation-independent gazes to update the internal representation, as they are expected to take place when the currently undertaken operation does no longer require the attention of the actor. On the basis of these results, conclusions regarding an assistance system for electrically powered wheelchairs have been drawn, which should – either on the basis of its user’s gaze behavior or on the past behavior – estimate the future intention of its user. These conclusions highlight the importance to consider individual differences in human-technology interaction and as such demonstrate that a close cooperation between the involved disciplines of engineering and psychology is necessary

The Role of Task and Situational Characteristics on the Dependability of Human-Technology Interaction

While the impact of "human error" on failures of complex human-technology systems has widely been demonstrated and accepted, the relevance of situational and task-related characteristics on human performance has not yet been considered sufficiently. For this purpose and on the example of electrically powered wheel chair control this paper analyzes the effects of situational characteristics ( e.g., turns to the left/right in the backward/forward driving mode) on the impact of fine motor abilities on human performance. A study with 23 participants is described in the paper, during which relevant data such as the subjects' precision and aiming capacity, the number of collisions caused while driving as an indicator for human performance, and the situational characteristics were measured. The data analyses demonstrate an influence of especially the number of turns driven to the right in the backward mode on the impact of the precision ability on the number of safety-critical collisions. The results highlight the necessity not only to develop a wheelchair system which is adaptable to the user’s fine motor abilities, but also to the situational characteristics in order to increase the dependability of the human-technology system at hand

Dependable System Design for Assistance Systems for Electrically Powered Wheelchairs

In this paper a system design approach is proposed, which is based on a user needs assessment and a flexible and adaptable architecture for dependable system integration. The feasibility of the approach is shown on the example of an assistance system for electrically powered wheelchairs. The system requirements correspond to the cognitive and motor abilities of the wheelchair users. For the wheelchair system built up based on a commercial powered wheelchair several behaviors have been realized such as collision avoidance, local navigation and path planning well known from robotic systems, which are enhanced by human-interfacing components. Furthermore, the system design will be high lighted which is based on robotic systems engineering. Due to the fundamental properties of the system architecture the resulting assistance system is inherently dependable, flexible, and adaptable. Corresponding to the current situation and the users’ abilities the system changes the level of assistance during real-time operation. The resulting system behavior is evaluated using system performance and usability tests

The Impact of Individual Differences in Fine Motor Abilities on Wheelchair Control Behavior and Especially on Safety-Critical Collisions with Objects in the Surroundings

In order to significantly reduce the number of safety-critical collisions of wheelchair users with objects spread in their environment, a study has been conducted which relates wheelchair user's fine motor abilities with the collisions while driving through a standardized course in a realistic office environment. The conducted inferential statistics demonstrate that especially the participants' aiming capacity can sign significantly predict the collisions occurring while driving through the course. A graphical and qualitative analysis of these effects demonstrates in addition that specific maneuvering tasks influence this relationship and that especially driving next to an object without colliding requires a high level of aiming capacity. The results demonstrate the need to develop a wheelchair system which adapts its assistive functionality to the aiming capacity and the difficulty of the maneuvering task in order to provide as much help as necessary without risking the degradation of the wheelchair user's skills

Predictive validity of wheelchair driving behavior for fine motor abilities: Definition of input variables for an adaptive wheelchair system

Abstract-This paper introduces an approach for dynamically adapting the level of automation of a wheelchair system on the basis of the current level of the user's motor abilities. For this purpose, a study is described, during which participants drove through a course consisting of 14 sub-sections. The predictive validity of the participants' wheelchair driving behavior on their precision, tremor, wrist-finger velocity, arm-hand velocity and aiming capability was analyzed. The results demonstrate impressively (1) that some course sections can better be used in order to derive variables allowing a reasoning on the users' motor ability level than other sections and (2) that especially the precision ability can be predicted e.g. on the basis of the distances driven in the forward mode. Implications on how an adaptive assistance system for powered wheelchair could be implemented are discussed as is the impact of such a system on the wheelchair market. (Abstract

How to Communicate with Pedestrians: Exploration of the Interplay of Dynamic HMI and External HMI for Different Sized Automated Vehicles

This study deals with the interplay of an external HMI to transmit explicit communication signals via 360° LED light-band and a dynamic HMI to transmit implicit communication signals via vehicle dynamics. Previous results on the interplay of dHMI and eHMI indicated that pedestrians tended to rely on the explicit communication via eHMI to indicate their willingness to cross. Nevertheless, this was investigated in a traffic scenario in which the automated vehicles approached from the left-hand side and the traffic rule “right before left” might have affected pedestrian's willingness. To rule this out, pre-recorded video sequences were shown in which the automated vehicles approached from the right-hand side. This study is work-in-progress and the data-collection is still ongoing. Results and further implications for future studies will be discussed

Modeling Driving Behavior at Roundabouts: Impact of Roundabout Layout and Surrounding Traffic on Driving Behavior

Driving behavior prediction at roundabouts is an important challenge to improve driving safety by supporting drivers with intelligent assistance systems. To predict the driving behavior effciently steering wheel status was proven to have robust predictability based on a Support Vector Machine algorithm. Previous research has not considered potential effects of roundabout layout and surrounding traffic on driving behavior, but that consideration can certainly improve the prediction results. Therefore, this study investigated how roundabout layout and surrounding traffic impact driving behavior of an ego car. A simulator study was conducted to collect driving behavior data with different roundabout layout settings and different surrounding cyclist position settings. The local minima/maxima of the steering angle was found to have a logarithmic relationship with the roundabout geometric feature. The impact of the surrounding traffic on the ego driver behavior was also found: When there were surrounding cyclists, the recognition rate of ego driver behavior patterns reached 100% later than when there was no surrounding traffic. In conclusion, driving behavior at roundabouts is effected by both roundabout layout and surrounding traffic, and the relationship can be expressed in a quantitative way

Toward a Holistic Communication Approach to an Automated Vehicle's Communication With Pedestrians: Combining Vehicle Kinematics With External Human-Machine Interfaces for Differently Sized Automated Vehicles

Future automated vehicles (AVs) of different sizes will share the same space with other road users, e. g., pedestrians. For a safe interaction, successful communication needs to be ensured, in particular, with vulnerable road users, such as pedestrians. Two possible communication means exist for AVs: vehicle kinematics for implicit communication and external human-machine interfaces (eHMIs) for explicit communication. However, the exact interplay is not sufficiently studied yet for pedestrians' interactions with AVs. Additionally, very few other studies focused on the interplay of vehicle kinematics and eHMI for pedestrians' interaction with differently sized AVs, although the precise coordination is decisive to support the communication with pedestrians. Therefore, this study focused on how the interplay of vehicle kinematics and eHMI affects pedestrians' willingness to cross, trust and perceived safety for the interaction with two differently sized AVs (smaller AV vs. larger AV). In this experimental online study (N = 149), the participants interacted with the AVs in a shared space. Both AVs were equipped with a 360° LED light-band eHMI attached to the outer vehicle body. Three eHMI statuses (no eHMI, static eHMI, and dynamic eHMI) were displayed. The vehicle kinematics were varied at two levels (non-yielding vs. yielding). Moreover, “non-matching” conditions were included for both AVs in which the dynamic eHMI falsely communicated a yielding intent although the vehicle did not yield. Overall, results showed that pedestrians' willingness to cross was significantly higher for the smaller AV compared to the larger AV. Regarding the interplay of vehicle kinematics and eHMI, results indicated that a dynamic eHMI increased pedestrians' perceived safety when the vehicle yielded. When the vehicle did not yield, pedestrians' perceived safety still increased for the dynamic eHMI compared to the static eHMI and no eHMI. The findings of this study demonstrated possible negative effects of eHMIs when they did not match the vehicle kinematics. Further implications for a holistic communication strategy for differently sized AVs will be discussed

Why drivers are frustrated: results from a diary study and focus groups.

Designing emotion-aware systems has become a manageable aim through recent developments in computer vision and machine learning. In the context of driver behaviour, especially negative emotions like frustration have shifted into the focus of major car manufacturers. Recognition and mitigation of the same could lead to safer roads in manual and more comfort in automated driving. While frustration recognition and also general mitigation methods have been previously researched, the knowledge of reasons for frustration is necessary to offer targeted solutions for frustration mitigation. However, up to the present day, systematic investigations about reasons for frustration behind the wheel are lacking. Therefore, in this work a combination of diary study and user focus groups was employed to shed light on reasons why humans become frustrated during driving. In addition, participants of the focus groups were asked for their usual coping methods with frustrating situations. It was revealed that the main reasons for frustration in driving are related to traffic, in-car reasons, self-inflicted causes, and weather. Coping strategies that drivers use in everyday life include cursing, distraction by media and thinking about something else, amongst others. This knowledge will help to design a frustration-aware system that monitors the driver’s environment according to the spectrum of frustration causes found in the research presented here