This paper investigates the human controllers’ sensitivity to added first-order lag-lead and lead-lag dy- namics in the controlled system dynamics using a cybernetic approach and a dedicated human-in-the-loop experiment. The extent to which human controllers will adapt their control dynamics to these added dynamics is objectively determined and explicitly compared to Maximum Unnoticeable Added Dynamics (MUAD) en- velopes from literature. Human control adaptation to added lag-lead and lead-lag dynamics is predicted for a wide range of lead and lag time-constants using offline human control model simulations, while a smaller subset of eight added dynamics settings, supplemented with a baseline condition, is tested in the experiment. Both the simulation predictions and experiment data show that human controllers will significantly adapt their control gains and lead time-constants to added lag-lead or lead-lag dynamics. Overall stronger adaptation is observed with added lag (i.e., high added dynamics lag time constants), which requires human controllers to generate more compensating lead equalization and results in degraded task performance. Collected sub- jective rating data also confirmed that added lag-lead dynamics were more noticeable for human controllers than added lead-lag. While overall these findings correspond well with literature, our experiment data shows that even for some conditions with added dynamics that remained within the MUAD boundaries statistically significant changes in human control gain and lead time-constants, compared to the baseline condition, occur. @en

Manual control tasks can be found everywhere in our daily activities, and the human ability to adapt in controlling many different vehicles such as cars and airplanes make it possible for us to travel farther, faster and higher. The human adaptation ability to changes in the controlled element dynamics is indispensable for tasks requiring high performance and safety, and none of the state-of-the-art automatic control systems can compete. For example, in the racing industry, professional racing drivers are needed to adapt to different car configurations and consistently push the car to its performance limit in the driving simulator and on the track, which is important for designing and tuning the cars. In aviation, pilots are our “last line of defense” for flight safety, especially in emergency situations in which automatic flight systems fail.@en