Design and development of a NextGen firefighting helmet that can provide both thermal and ballistic protection
Evaluating the effect of fatigue on virtual reality forklift driving
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.
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.
Estimation of the spatial and temporal co-registration errors between real and virtual objects in a physically interactive virtual reality (VR) system
Virtual reality (VR) systems with multisensory (auditory, visual, and haptic) feedback have proven to be a viable replacement for live training scenarios in training and functional motor learning, such as in simulating military training scenarios and novel scenarios that cannot be replicated in the real world (e.g., accidents) for industrial safety training. Moreover, VR training has been shown to be equally (if not more) effective as conventional physical therapy for functional motor rehabilitation. Although visual and auditory feedback in VR systems is common for training and motor rehabilitation, simulating haptic interactions within virtual environments (VEs) is challenging. Many devices developed for providing haptic feedback inside virtual
environments are limited by several factors, such as size and weight limitations, high cost-benefit ratio and complexity, lack of diverse applicability, and low fidelity (or realism). Recent studies have utilized physical props to simulate haptic feedback in physically interactive VR systems to mitigate the limitations of haptic devices. It is important to note that, in order to develop a high-fidelity VR system using physical props for motor recovery and motor learning, the position and orientation tracking (i.e., surface registration) of the physical props should be of sufficient accuracy (low offsets between real and virtual objects’ position and orientation in the tracking space) and the latency between the physical movement of the props and the corresponding update in the VE display (i.e., temporal registration) should be low. The purpose of this study is to develop a physically interactive VR system using physical props and to evaluate the effectiveness of the developed system in terms of the surface and temporal registration of real and virtual objects.
Human-centered healthcare exoskeleton design