A Method to Estimate Operator's Mental Workload in Multiple Information Presentation Environment of Agricultural Vehicles

The development of mechanized agriculture has brought many new features to agricultural vehicles today. Considering more human limitations, such as situational awareness and the potential for mental overload, operator's mental workload seems to be a critical issue. This study presents a quantitative method for determining the mental workload imposed on agricultural vehicle operators and to express their mental workload by means of a model that was objective and could stand up to the test of validity. The proposed model consisted of three task elements and six weighted moderating factors. And a modified task workload analysis measurement was used to validate the model by analyzing video recordings of eighteen subjects working in three combine harvester vehicles over an eight-hour shift. The comparison results implied the model's validity. Subjective workload was mildly correlated with the three task elements in the model. It is shown to provide an objective method for assessment and prediction of operator's mental workload in the multiple information presentation environment of farming machines.