TY - JOUR A1 - Pascher, Max A1 - Kronhardt, Kirill A1 - Franzen, Til A1 - Gruenefeld, Uwe A1 - Schneegass, Stefan A1 - Gerken, Jens T1 - My Caregiver the Cobot: Comparing Visualization Techniques to Effectively Communicate Cobot Perception to People with Physical Impairments JF - Sensors N2 - Nowadays, robots are found in a growing number of areas where they collaborate closely with humans. Enabled by lightweight materials and safety sensors, these cobots are gaining increasing popularity in domestic care, where they support people with physical impairments in their everyday lives. However, when cobots perform actions autonomously, it remains challenging for human collaborators to understand and predict their behavior, which is crucial for achieving trust and user acceptance. One significant aspect of predicting cobot behavior is understanding their perception and comprehending how they “see” the world. To tackle this challenge, we compared three different visualization techniques for Spatial Augmented Reality. All of these communicate cobot perception by visually indicating which objects in the cobot’s surrounding have been identified by their sensors. We compared the well-established visualizations Wedge and Halo against our proposed visualization Line in a remote user experiment with participants suffering from physical impairments. In a second remote experiment, we validated these findings with a broader non-specific user base. Our findings show that Line, a lower complexity visualization, results in significantly faster reaction times compared to Halo, and lower task load compared to both Wedge and Halo. Overall, users prefer Line as a more straightforward visualization. In Spatial Augmented Reality, with its known disadvantage of limited projection area size, established off-screen visualizations are not effective in communicating cobot perception and Line presents an easy-to-understand alternative. KW - cobot KW - human-robot collaboration KW - projection KW - virtual reality KW - visualization techniques Y1 - 2022 U6 - https://doi.org/10.3390/s22030755 SN - 1424-8220 VL - 22.2022 IS - 3 SP - Artikelnr. 755 PB - MDPI CY - Basel ER - TY - JOUR A1 - Kronhardt, Kirill A1 - Rübner, Stephan A1 - Pascher, Max A1 - Goldau, Felix Ferdinand A1 - Frese, Udo A1 - Gerken, Jens T1 - Adapt or Perish? Exploring the Effectiveness of Adaptive DoF Control Interaction Methods for Assistive Robot Arms JF - Technologies N2 - Robot arms are one of many assistive technologies used by people with motor impairments. Assistive robot arms can allow people to perform activities of daily living (ADL) involving grasping and manipulating objects in their environment without the assistance of caregivers. Suitable input devices (e.g., joysticks) mostly have two Degrees of Freedom (DoF), while most assistive robot arms have six or more. This results in time-consuming and cognitively demanding mode switches to change the mapping of DoFs to control the robot. One option to decrease the difficulty of controlling a high-DoF assistive robot arm using a low-DoF input device is to assign different combinations of movement-DoFs to the device’s input DoFs depending on the current situation (adaptive control). To explore this method of control, we designed two adaptive control methods for a realistic virtual 3D environment. We evaluated our methods against a commonly used non-adaptive control method that requires the user to switch controls manually. This was conducted in a simulated remote study that used Virtual Reality and involved 39 non-disabled participants. Our results show that the number of mode switches necessary to complete a simple pick-and-place task decreases significantl when using an adaptive control type. In contrast, the task completion time and workload stay the same. A thematic analysis of qualitative feedback of our participants suggests that a longer period of training could further improve the performance of adaptive control methods. KW - assistive robotics KW - human robot interaction KW - shared user control KW - Augmented reality KW - visual cues KW - Erweiterte Realität Y1 - 2022 U6 - https://doi.org/10.3390/technologies10010030 VL - 10.2022 IS - 1 PB - MDPI CY - Basel ER -