  Telerobotics has shown promise in helping workers safely manipulate building
components on construction sites; however, its primary reliance on visual
feedback limits efficiency in situations with stiff contact or poor visibility.
Reliable and economical haptic feedback could fill this perception gap and
facilitate construction activities. Thus, we designed an audio-based haptic
feedback system that measures the vibrations experienced by the robot tools and
enables the operator to feel them in real time. Accurate haptic transmission
was achieved by optimizing the positions of the system's off-the-shelf
accelerometers and voice-coil actuators. A user study was conducted to evaluate
how this naturalistic type of vibration feedback affects the operator's
performance in telerobotic assembly. Thirty participants used a bimanual
teleoperation system to build a structure under three randomly ordered haptic
feedback conditions: no vibrations, one-axis vibrations, and three-axis
vibrations. The results show that users took advantage of both kinds of haptic
feedback after gaining some experience with the task, causing significantly
lower vibrations and forces in the second trial. Subjective responses indicate
that haptic feedback reduced the perceived task difficulty, task duration, and
fatigue. These results demonstrate that providing this type of vibrotactile
feedback on teleoperated construction robots would enhance user performance and
experience.
