No abstract

The recent ubiquity of high-framerate (120 fps and higher) handheld cameras creates the opportunity to study human grasping at a greater level of detail than normal speed cameras allow. We first collected 91 slow-motion interactions with objects in a convenience store setting. We then annotated the actions through the lenses of various existing manipulation taxonomies. We found manipulation, particularly the process of forming a grasp, is complicated and proceeds quickly. Our dataset shows that there are many ways that people deal with clutter in order to form a strong grasp of an object. It also reveals several errors and how people recover from them. Though annotating motions in detail is time-consuming, the annotation systems we used nevertheless leave out important aspects of understanding manipulation actions, such as how the environment is functioning as a "finger" of sorts, how different parts of the hand can be involved in different grasping tasks, and high-level intent.

No abstract

The use of both hands simultaneously when manipulating objects is fairly commonplace, but it is not known what factors encourage people to use two hands as opposed to one during simple tasks such as transport. In particular, we are interested in three possible transport strategies: unimanual transport, handing off between hands, and symmetric bimanual transport. In this study, we investigate the effect of object size, weight, and starting and ending position (configuration) as well as the need to balance the object on the use of these three strategies in a bowl-moving task. We find that configuration and balance have a strong effect on choice of strategy, and size and weight have a weaker effect. Hand-offs are most often used when the task requires moving an object from left to right and vice versa, while the unimanual strategy was frequently used when passing front to back. The bimanual strategy is only weakly affected by configuration. The need to balance an object causes subjects to favor unimanual and bimanual strategies over the hand-off. In addition, an analysis of transport duration and body rotation suggests that strategy choice may be driven by the desire to minimize body rotation.

No abstract