Virtual environment to evaluate multimodal feedback strategies for augmented navigation of the visually impaired

This paper proposes a novel experimental environment to evaluate multimodal feedback strategies for augmented navigation of the visually impaired. The environment consists of virtual obstacles and walls, an optical tracking system and a simple device with audio and vibrotactile feedback that interacts with the virtual environment, and presents many advantages in terms of safety, flexibility, control over experimental parameters and cost. The subject can freely move in an empty room, while the position of head and arm are tracked in real time. A virtual environment (walls, obstacles) is randomly generated, and audio and vibrotactile feedback are given according to the distance from the subjects arm to the virtual walls/objects. We investigate the applicability of our environment using a simple, commercially available feedback device. Experiments with unimpaired subjects show that it is possible to use the setup to "blindly" navigate in an unpredictable virtual environment. This validates the environment as a test platform to investigate navigation and exploration strategies of the visually impaired, and to evaluate novel technologies for augmented navigation.