Improving Usefulness of Automated Driving by Lowering Primary Task Interference through HMI Design

Frederik Naujoks,Katharina Wiedemann,Yannick Forster,Alexandra Neukum

doi:10.1155/2017/6105087

Abstract

During conditionally automated driving (CAD), driving time can be used for non-driving-related tasks (NDRTs). To increase safety and comfort of an automated ride, upcoming automated manoeuvres such as lane changes or speed adaptations may be communicated to the driver. However, as the driver’s primary task consists of performing NDRTs, they might prefer to be informed in a nondistracting way. In this paper, the potential of using speech output to improve human-automation interaction is explored. A sample of 17 participants completed different situations which involved communication between the automation and the driver in a motion-based driving simulator. The Human-Machine Interface (HMI) of the automated driving system consisted of a visual-auditory HMI with either generic auditory feedback (i.e., standard information tones) or additional speech output. The drivers were asked to perform a common NDRT during the drive. Compared to generic auditory output, communicating upcoming automated manoeuvres additionally by speech led to a decrease in self-reported visual workload and decreased monitoring of the visual HMI. However, interruptions of the NDRT were not affected by additional speech output. Participants clearly favoured the HMI with additional speech-based output, demonstrating the potential of speech to enhance usefulness and acceptance of automated vehicles.

Highlights

The current study investigated whether speech output could improve human-machine cooperation in the area of conditionally automated driving (CAD)
We investigated whether additional speech output would facilitate humanautomation cooperation by effectively informing the driver about upcoming automated driving manoeuvres and would, cause less interference with the execution of a non-driving-related tasks (NDRTs)
It became apparent that drivers spent more time looking at the Human-Machine Interface (HMI) in the “generic” condition compared with the “speech + generic” condition when the HMI without additional speech output was experienced in the first drive

Summary

Introduction

Getting the driver back into the loop as fast as possible has been the focus of a large body of research (see [24], for an overview), as this function of the in-vehicle HMI can be viewed as a key element for the safety of automated vehicles This focus has moved away from imminent takeover requests to exploring the potential of providing drivers with on-trip information related to the vehicle automation. Conditionally automated vehicles may be capable of managing certain noncritical driving situations without any driver intervention, such as overtaking or adaptation of the host vehicle’s speed In such situations, it may be necessary to communicate the actions initiated by the automation by suitable HMI elements in an unambiguous way to avoid distrust and unnecessary manual interventions [29]. Walch et al [34] even suggest to involve the driver into the decision making process whether an automated manoeuvre should be carried out or not

Methods

Results

Conclusion