# UX in AR-Supported Industrial Human-Robot Collaborative Tasks: A Systematic Review
## 3 Review Results
### What Are the State of the Art UX Approaches in AR-Supported Collaborative Solutions? The current trends in the design of collaborative tasks supported by AR technologies do not systematically show a great attention to UX topics. [PERSON] et al. [8] proposed an interactive user interface to assist O4.0 in performing robot-assisted tasks comparing two separate implementations of the same system: a projection-mirror setup, and a wearable device (i.e., Microsoft Hololens). No prior UX assessment was proposed; as part of the subjective evaluation, a final questionnaire including 13 questions divided into six categories (respectively: safety, information processing, ergonomics, autonomy, competence, and relatedness) was submitted to roughly understand mental and physical stress. Comments from users were collected to deepen the subjective impression, without using any structured method to collect the perceived workload, as used for instance in different contexts. A more structured approach is presented by [PERSON] et al. [34]: the paper emphasizes the need of a seamless integration between the human operator and his robotic counterpart by monitoring both working entities through sensors and wearable devices. This led to the re-design of the workplace from the human point of view to promote both the robot's operability and operator's mobility, without any barrier to separate them; a multi-stage iterative process has been followed, starting from technical and functional specifications as well as safety requirements. A digital simulation is included for supporting cell setup and risk assessment. [PERSON] et al. [18] placed attention on AR devices' usability as enabling tools. The authors reported how usability, workload, and likability can be investigated thanks to the standardized questionnaire (e.g., NASA-TLX [52], System Usability Scale (SUS) [53], AttrakDiff [54]). The same intention is expressed by [PERSON] et al. [35], who introduced a novel AR handheld device inspired by the abovementioned multimodality perceptive interface, incorporating hand gesture mapping, haptic buttons, and laser pointers. The system can suggest available options to the operator and wait for a response instead of traditional inputs by keyboard or mouse; a usability investigation is eventually foreseen to improve the interface effectiveness with the help of user's feedbacks. [PERSON] et al. [36] evaluated the idea of spatial augmented reality (SAR) through a UX study. The outlined approach works towards avoiding continuous switching of attention during demanding tasks, thanks to a correct distribution of information along the operations and a shared workplace, to be usable also for non-expert users. Process simplification was also addressed by [PERSON] et al. [37] to reduce the installation time of hybrid robot-human production lines, and by [PERSON] et al. [38] that defined a  
Figure 3: Papers by subject’s area. new process of skill transfer between human workers and robots. Similarly, [PERSON] et al. [49] presented a holistic UX framework (called \"Kinetic AR\") for visual programming of robotic motions using AR: the goal was to guarantee a low entry barrier to intricate spatial hardware programming. The UX approach was achieved through interviews to robotic system integrators, manufacturers, and end-users with different expertise, to finally identify the goals and requirements to be accomplished. Communications and interactions were also investigated by [PERSON] et al. [39], using 3D immersive simulation to support the design and validation of natural HRI in generic usage contexts, comparing an AR interface and a non-AR one. Among others, subjective observations were gathered through the SASSI methodology [55] to evaluate speech interaction in both interfaces. Information on completion times, overall satisfaction, ease of use, perceived time requested, and support information were collected, and their statistical relevance was given by running an independent sample \(t\)-test.