Demo video: https://drive.google.com/file/d/1TOUk4YbP6ds5OvcX2bLZXdLo2ps8LIA8/view
The e-commerce and online retail trends are fueling the rapid growth of urban-centric, space-efficient warehousing, distribution, and fulfillment industries, which may drive increasing demand for forklifts. Furthermore, fatigue-induced injuries are widespread among forklift operators due to the monotonous nature of forklift operation, long shift hours, and time-of-day. One of the grand challenges for the material handling industry is to tackle the fatigue-induced impairment in the work performance of forklift operators, which depends on both the neural and muscular activities of the operators. To tackle forklift-related accidents and injuries, the Occupational Safety and Health Administration (OSHA) requires every operator to undergo training to improve safety and efficiency. Virtual reality (VR) technology plays a pivotal role in training forklift operators and has been adopted by many industries along with traditional training courses. Since drivers can fully immerse themselves to practice forklift driving and maneuvering in the VR environment, VR technology can also be used to simulate a fatigued driving scenario so that drivers can easily review and rectify their driving techniques, and more importantly, "virtual accidents". As a result, they become more situation-aware in handling adverse conditions. To our knowledge, no previous study has explored the utilization of VR technology to avoid driver fatigue-related casualties.
Therefore, in this study, we aimed to evaluate the effect of fatigue on virtual forklift driving and whether the VR-based performance feedback improves participant's situation awareness (i.e., decreasing the number of errors and task completion time). We also aimed to obtain a correlation between neural and activities of virtual forklift drivers under fatigued and non-fatigued conditions to better understand the causal relationship between fatigue and neuromuscular functions. We developed a virtual reality forklift driving simulator system using a DOFReality Motion Simulator Platform P3 (DOFReality Inc., Pustomyty, Ukraine) and the HTC Vive Pro Eye virtual reality system (HTC Corporation, New Taipei, Taiwan and Valve Corporation, Bellevue, Washington, USA). Participants performed three sets of virtual forklift driving: non-fatigued, fatigued, and fatigued-with-feedback conditions. To warrant accumulated physical and cognitive fatigue prior to the second and third sets of forklift driving tasks, the participants performed multiple manual material handling tasks and a 2-back cognitive task. We ensured the presence of fatigue by analyzing NASA-TLX (e.g., cognitive and physical demands), surface electromyography (sEMG) (physical fatigue), electroencephalogram (EEG) (psychophysical fatigue), and eye-tracking data using a wavelet-based signal processing algorithm. We hypothesized that forklift driving under fatigued conditions significantly affects driving performance and performance feedback significantly reduces possible fatigue-induced driving errors.