Page - 149 - in Proceedings - OAGM & ARW Joint Workshop 2016 on "Computer Vision and Robotics“

unprecise for teaching positions that way. Overall, the teaching of expansion stage 1 was rated as low with respect to usability, user experience, and acceptance, which can be explained by the fact that the actual teaching was only a fraction of the whole process, which was experienced as too complicated due to the touch panel. Trial 3 revealed that in the actual collaboration with the robot its working pace was perceived as not flexible enough, which bears the risk to re-establish a rigid production line logic. More details on the studies can be found in [14]. User Trial 1 Use case A User Trial 2 Use case B User Trial 3 Use case A Environment Factory Laboratory Factory (assembly line) Task Teaching of screw positions Teaching of polishing positions Cooperative screwing Duration 1 day 2 days 3 weeks No. of Participants 5 5 5 Research Methods Oberservation, Questionnaires Oberservation, Questionnaires Interviews Table 1. Overview of the three user trials. 6. Inferred usability improvements 6.1 Technical project outlook: Expansion stage 2 Usability studies yielded requirements regarding robot hand guidance. Gear friction yields stacking and imprecise movement. Locking of certain degrees of freedom (e.g. rotation or translation,…) is asked for by users as well as semiautomatic tool alignment and expected to improve both programming time and process quality. A state of the art force torque sensor was integrated as well as buttons to call perpendicular realignment (Figure 4) or locking of rotational or translational degrees of freedom. 6.2 Technical project outlook: Expansion stage 3 Collaboration can be improved by adding visual feedback on the robot and the work piece during the teaching (to reduce the burden of switching attention between the robot and touch panel). [15] [16] introduce the notion Spatial Augmented Reality (SAR) and describe it as enhancement or aggregation of several Augmented Reality (AR) technologies. One formulation [17] might be a depth camera projector based system to project (correctly distorted) information on three dimensional objects instead of flat screens (Figure 3) and may be used for projection of buttons. (Applied) robotics does not make use of SAR methods extensively. [18] introduces a projection- based safeguard system for robotic workspaces especially for collaboratively used workspace. [19] gives an overview on Tangible User Interfaces (TUI) which denote interfaces that can be manipulated physically, and which have an equivalent in the digital world and represent a mean for interactive control. The project proposes a combination of TUI and SAR methods. Hand guided positioning of the robot might be uncomfortable or time consuming due to inappropriate input modalities (friction afflicted robot drives, unintuitive touch screens,…). 149