Haptic, Auditory, or Visual?: Towards Optimal Error Feedback at Manual Assembly Workplaces

We are observing a trend that more and more manual assembly workplaces are equipped with sensor technology to assist workers during complex work tasks. These assistive systems mostly use visual feedback for providing assembly instructions or hinting at errors. However, a red light indicating an error might not always be the best solution for communicating that an error was made, or might be overlooked in stressful situations. Therefore, we extended an assitsive system to compare haptic, auditory, and visual error feedback at the manual assembly workplace. Through two user studies, we first determine suitable variants for each error feedback modality and second compare the error feedback modalities against each other. The results show that haptic feedback is appropriate for retaining the worker's privacy, and auditory feedback is perceived as most distracting. The subjective feedback reveals interesting insights for future research in communicating errors as a combination of haptic and visual feedback might lead to noticing an error faster.