Physical interactions within virtual environments are often limited to visual information within a restricted workspace. A new system exploiting a cable-driven parallel robot to combine visual and haptic information related to environmental physical constraints (e.g. shelving, object weight) was developed. The aim of this study was to evaluate the impact on user movement patterns of adding haptic feedback in a virtual environment with this robot. Twelve healthy participants executed a manual handling task under three conditions: 1) in a virtual environment with haptic feedback; 2) in a virtual environment without haptic feedback; 3) in a real physical environment. Temporal parameters (movement time, peak velocity, movement smoothness, time to maximum flexion, time to peak wrist velocity) and spatial parameters of movement (maximum trunk flexion, range of motion of the trunk, length of the trajectory, index of curvature and maximum clearance from the shelf) were analysed during the reaching, lowering and lifting phases. Our results suggest that adding haptic feedback improves spatial parameters of movement to better respect the environmental constraints. However, the visual information presented in the virtual environment through the head mounted display appears to have an impact on temporal parameters of movement leading to greater movement time. Taken together, our results suggest that a cable-driven robot can be a promising device to provide a more ecological context during complex tasks in virtual reality.

中文翻译：

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使用电缆驱动机器人向虚拟环境添加触觉反馈可改善手动搬运任务期间的上肢时空参数


虚拟环境中的物理交互通常仅限于有限工作空间内的视觉信息。开发了一种新系统，利用电缆驱动的并联机器人来结合与环境物理约束（例如货架、物体重量）相关的视觉和触觉信息。本研究的目的是评估在该机器人的虚拟环境中添加触觉反馈对用户运动模式的影响。十二名健康参与者在三种条件下执行手动处理任务：1）在具有触觉反馈的虚拟环境中； 2）在没有触觉反馈的虚拟环境中； 3）在真实的物理环境中。运动的时间参数（运动时间、峰值速度、运动平滑度、最大屈曲时间、腕关节峰值速度时间）和运动空间参数（躯干最大屈曲、躯干运动范围、轨迹长​​度、曲率指数和最大曲率指数）。与货架的间隙）在到达、降低和提升阶段进行了分析。我们的结果表明，添加触觉反馈可以改善运动的空间参数，从而更好地尊重环境限制。然而，通过头戴式显示器在虚拟环境中呈现的视觉信息似乎对运动的时间参数有影响，导致更长的运动时间。总而言之，我们的结果表明，电缆驱动的机器人可能是一种有前景的设备，可以在虚拟现实中的复杂任务中提供更加生态的环境。