Study on mental workload assessment of tank vehicle operators

In order to monitor and evaluate the mental load of the operators in the operation of tank vehicle more effectively, and ensure the safe and efficient operation of tank man-machine-environment system. Using the tank vehicle operation simulation experiment platform, the tank firing experiment task was simulated according to three links of perception, judgment and decision-making, and motion execution. The changing trend of the tank vehicle operator’s mental load was analyzed from two aspects of subjective performance and EEG signal characteristics. After the completion of the simulated tank shooting experiment task, the subjects’ thinking clarity, sleepiness, fatigue comprehensive assessment, emotional state and motivation level were all significantly improved (P < 0.01); with the increase of task difficulty, the scores of NASA-TLX load scale in different task loads were improved, and after weight comparison, the total score and mental demand both had very significant difference between low load and medium load, and between low load and high load (P < 0.01), and had significant difference between medium load and high load (P < 0.05). There was no significant difference in performance level between high, medium and low task loads (P > 0.05). There was significant difference in time demand, effort and frustration between low and high load (P < 0.05), and no significant difference between low and medium load, medium and high load (P > 0.05). The number of firing times per unit time with different task difficulty was significantly different between low and medium load, low and high load (P < 0.01), but no significant difference between medium and high load (P > 0.05). For EEG power spectrum characteristics, α, β, α/θ, β/θ, (α + β)/θ index were all sensitive to mental load level, but only α and β were significantly. Subjective questionnaires and performance data can objectively reflect the level of mental load in different difficulty tasks. For different time periods of tasks, the times of pressing shoot keys can reflect the changing trend of mental load in the process of tasks. Among EEG indicators, α and β can effectively evaluate the level of mental workload.