Complementing Automotive Haptic Shared Control with Visual Feedback for Obstacle Avoidance

Abstract

The technological advancements in the automotive industry have enabled the automation of numerous routine driving tasks. As a result, the art of driving has become a control task with a strong supervisory character, including the common human factor issues. Haptic Shared Control has been shown to be useful in keeping the driver in-the-loop by providing continuous haptic guidance on the steering wheel. Nonetheless, it has been reported that haptic support often induces control conflicts caused by the limited amount of information that can be conveyed through haptic forces. As a consequence, it is often burdensome to develop a correct mental model of the underlying controller and to establish accurate situation awareness. This study presents the results of the conceptual development of a novel visual feedback system inspired by the principle of Ecological Interface Design. By displaying the future trajectory with respect to both the physical limitations of the vehicle and the intentional constraints imposed by the road, the driver is able to establish a better understanding of the space of possibilities in a certain driving scenario. The new visual feedback is combined with current haptic feedback solutions, with the goal of guiding the driver through force-feedback, while visualizing the space of possibilities as defined by the work domain constraints. A human-in-the-loop experiment was conducted to evaluate the effects of the novel feedback system on driver behavior and acceptance during an obstacle avoidance task. In analogy with previous findings, the results showed that haptic guidance was beneficial during obstacle avoidance in terms of response time, control activity and effort, where the addition of EID-inspired visual feedback revealed an improved task execution, together with a significant reduction of control activity and conflicts.