Sagardia Mikel, Hulin Thomas
IEEE Trans Haptics. 2018 Jan-Mar;11(1):107-118. doi: 10.1109/TOH.2017.2741488. Epub 2017 Aug 18.
What are the technological bottlenecks in virtual assembly simulations with haptic feedback? To tackle this question, we present an evaluation study in which real feedback modalities are gradually replaced by synthetic ones. In particular, the effects of the following factors on the user performance and perception during virtual assemblies are analyzed: () a visual feedback system consisting of an nVisor head-mounted display, () our haptic device HUG suited for unscaled upper-body movements, and () our novel six-DoF constraint-based haptic rendering algorithm. Besides that, the influence of ( ) real collision sounds is also examined to a lesser extent. The experimental assembly scenario consisted of three variations of peg-in-hole tasks which were performed by a total of participants in a within-design study. The mentioned three synthetic factors ( )-( ) gradually replaced in five degrees or steps the real feedback sources, ending up in completely virtual assembly simulations. For each of the degrees, three objective variables (completion time, collision forces, and muscular effort) and five subjective ratings (related to the perception of realism and the workload) were recorded and statistically analyzed. In order to explain subjective perception also with objective measures, reaction times of a secondary audio task performed in parallel with the assembly exercises were recorded, too. While previous works have mainly focused on differences of completion time between real and virtual manipulations, our results show how all of the mentioned twelve performance and perception indicators are influenced by each of the four varied feedback factors, building a multi-modality relationship function that maps our or similar systems and expected user responses. In general, the haptic feedback modality turned out to have the largest impact on the dependent variables, particularly the HUG interface, whereas audio cues seemed to be less significant. We quantify these previous and further qualitative statements within the domain defined by the used systems. Moreover, the relationship of our insights with related other work is discussed, and their projections are outlined.
具有触觉反馈的虚拟装配模拟中的技术瓶颈有哪些？为了解决这个问题，我们开展了一项评估研究，其中真实反馈模式逐渐被合成反馈模式所取代。具体而言，分析了以下因素在虚拟装配过程中对用户性能和感知的影响：（1）由nVisor头戴式显示器组成的视觉反馈系统；（2）适合无比例上身运动的触觉设备HUG；（3）我们基于六自由度约束的新型触觉渲染算法。除此之外，还在较小程度上考察了真实碰撞声音的影响。实验装配场景由三种不同的插销入孔任务变体组成，在一项设计内研究中，共有多名参与者完成了这些任务。上述三个合成因素（1）至（3）以五个程度或阶段逐渐取代真实反馈源，最终形成完全虚拟的装配模拟。对于每个程度，记录并统计分析了三个客观变量（完成时间、碰撞力和肌肉用力）和五个主观评分（与真实感和工作量感知相关）。为了也用客观指标解释主观感知，还记录了与装配练习并行执行的次要音频任务的反应时间。虽然先前的研究主要关注真实操作和虚拟操作之间完成时间的差异，但我们的结果表明，上述所有十二个性能和感知指标如何受到四个不同反馈因素中每一个的影响，构建了一个多模态关系函数，该函数映射了我们的系统或类似系统以及预期的用户响应。总体而言，触觉反馈模式对因变量的影响最大，特别是HUG接口，而音频提示似乎不太重要。我们在所用系统定义的领域内量化了这些先前的以及进一步的定性陈述。此外，还讨论了我们的见解与其他相关工作的关系，并概述了它们的预测。
