Comparative assessment of human machine interfaces for ROV guidance with different levels of secondary visual workload

Due to relatively slow dynamics of ROVs, pilot are given extra time to perform other tasks, such as inspections and arm operation. However, during multiple task handling, relevant information is typically dispersed on a number of screens overloading the pilot´s visual channel. There is very little research examining the unique human-factors problems associated with unmanned underwater vehicles. Use of audio display has been suggested as a means to reduce visual workload, to enhance situation awareness, and mitigate the visual and cognitive demands of contemporary ROV operations. Our research investigates the effects of secondary visual tasks on operators workload and performance using standard visual navigation interface, augmented reality visual interface and audio interface. All experiments were performed on the state-of-the-art, real-time ROV simulator developed by Mobile & Marine Robotics Research Centre, University of Limerick and augmented reality system developed by Laboratory for Underwater Systems and Technologies, University of Zagreb. As expected, the results show that in no-load conditions visual guidance is better than the guidance-by-sound. By contrast, the effects of secondary visual load affect operators´ performance. The use of augmented reality paradigm and especially hearing, in the form of the auditory display, emerges as an important advantage. Improvement depends on a level of experience in using auditory guidance system. Practice has a major effect on performance, raising the conclusion that there is a more room for improvement in using auditory interface.