Assessment and Evaluation of Human States
Cluster 3 focuses on an assessment and evaluation of human states. The interconnected nature of cyber-physical production systems (CPPS) makes it possible to measure human physiological and psychological data and link them to events in the technical system. In order to operate a CPPS efficiently and safely, operators need to develop a deeper understanding of the system’s state and functioning in order to make context-appropriate decisions. The information about the operator’s workload can be gained from direct observation of human physiological and attentional processes (e.g. autonomic nervous system activity, eye movement patterns).
The following three research make complementary contributions to acquisition of information about the human operator as well as human-machine cooperation in CPPS.
This research focuses on the development of a scientific method that combines the (1) the physical configuration and reconfiguration of modular plants, (2) the ergonomic requirements and (3) the prospective, evidence-based, practical applicability. The methodological approach is designed in an interdisciplinary context in such a way that the methodological procedure can be conceptualized and tested in practice while following the epistemological logic.
Methods for unobtrusive, non-contact measurement of biosignals with camera-based photoplethysmography are developed, which allow the derivation of vital signs (e.g. heart rate, respiration rate) for the assessment of the human states. A key challenge is the robust extraction of the signals, since work environments are typically non-stationary and motion artifacts distort the measurement. Research in this area includes, for example, methods to optimize the combination of color channels (color videos are typically composed of the three channels red, green and blue) and methods to evaluate the quality and trustworthiness of extracted vital signs. In addition, an extensive study was conducted to investigate the use of camera-based photoplethyssmography during mental stress.
Analyzing the time course of eye movements during free exploration of real-world scenes often indicates that people progress through two distinct phases of visual processing: an ambient, or exploratory, phase that emphasizes input from peripheral vision and rapid acquisition of low-frequency information, followed by a focal phase that emphasizes central vision, salient objects, and high-frequency information. Does this qualitative attentional shift occur during performance of characteristic tasks in a CPPS? If so, when? This topic is of relevance to better understand the nature of the ambient and focal processing mechanisms. Identifying such pattern at various levels of task completion provides an indicator for individual task processing strategies. By using different task scenarios that reflect the flexible nature of CPPS and investigating the eye movement parameters associated with the performance of characteristic tasks, this research provides important insights into operators’ attention and cognitive processing underlying the work processes in these complex systems.
The high diversity of the different approaches towards state assessment and evaluation leads to an in-depth analysis and understanding of what impact different cooperation paths exert on humans. The different perspectives can provide valuable inputs for designing system adaptations and means of developing operator competencies.