Categorization of Contact Events as Intended or Unintended using Pre-Contact Kinematic Features

Contact events are essential to the execution of manipulation tasks in virtual reality because they mark the different phases of an interaction, e.g. initial hand-object or tool-object contact. Generally, the nature of contact events can be distinguished in two categories: intended and unintended. Whereas intended contacts typically signalize the successful execution of a task, unintended contacts are the result of bad motor planning or execution, or are caused by accidental movements.Here we explore the use of kinematic features to distinguish intended and unintended contacts during an object placing task executed in virtual reality. A handheld object was placed over a horizontal surface with a vertical planar movement. The experimental setup enabled us to generate unintended contacts by triggering unexpected interruptions during the placing movement.Experimental results show significant differences between distributions of the kinematic features across intended and unintended contacts. These results indicate that the proposed kinematic features enable a robust distinction between intended and unintended contacts independent of substantial variations of movement properties (amplitude, duration, velocity).