Towards intuitive interfaces

Abstract: Operators like fighter pilots, combat vehicle drivers and fire and rescue command operators handle considerable amount of information during mission critical activities. The increasing complexity of the information landscape calls for alternative information presentation. This thesis presents the rather novel interfaces 3D audio and tactile displays, and the combination of these. In several experiments the displays are evaluated on the basis that they could improve information presentation for specific real world scenarios. The experimental environments range from laboratory to real platform in which intelligibility, reaction/response time, and localisation error are measured. A number of key findings are presented such as further evidence for using non-individualised Head Related Transfer Function (HRTF) to acquire low localisation errors for virtual sound sources. It is also shown that 3D audio presented with a Commercials Off The Shelf (COTS) component could be used to support operators in real world settings, and that a tactile display can counteract front-back confusion occurrences as induced by 3D audio. In addition, results demonstrate that a tactile display can be used to present information to fighter pilots during threat interception, at high G-loads, and improve responses to threats. In a series of experiments concerning threat presentation to the driver of a combat vehicle it was found that combining displays for different sensory modalities can improve tactical manoeuvring performance without adding mental workload. It was also shown that the displays entailed different support for the driver depending on phases of manoeuvring towards threats. The main conclusion drawn from this research is that these display technologies carry much promise for improving the information presentation in complex operator environments. It is mainly the omnidirectional character of the tactile and 3D audio presentations that contributes significantly to the making of intuitive interfaces, which can lead to enhanced perception and performance without adding workload. One application of these relatively new display technologies is to support visual displays in situations in which the operator already is engaged in activities occupying the visual sense.