A Multidimensional Method for Pilot Workload Assessment and Diagnosis

INTRODUCTION: Pilot workload assessment plays an important role on flight safety evaluation, interface design, and airworthiness certification. The design of an effective and reliable workload assessment method is a difficult problem in the human factors field.METHOD: This study proposed to assess pilot workload from four dimensions: cognitive activity, control activity, stress, and flight performance. A set of physiological, behavioral, and flight parameters were recorded and combined hierarchically to achieve overall workload assessment. A simulated flight experiment consisting of three flight phases (standard instrument departure, autopilot cruise, and nonprecision approach) was conducted to test the effectiveness of the proposed workload assessment method.RESULT: Experimental results determined the changes of each objective measure. The overall workload index could significantly distinguish the difference in workload caused by changing task difficulty and the result was consistent with the NASA-TLX. The four workload dimensions provided detailed differences about workload: during nonprecision approach there were more control activities and stress than in other flight phases; during autopilot cruise there were the least control activities and the highest flight performance. The correlation between workload dimensions provided extra diagnostic information: the cognitive and control activities in the approach phase were more stressful than in the takeoff phase; the correlation between control activity and performance was higher in the approach phase than in the takeoff phase.CONCLUSION: This study proposed an effective pilot workload assessment method which could also provide detailed and diagnostic information. It could be used as an auxiliary tool for the development and evaluation of pilot-cockpit interaction.Wang Z, Lu Y, Fu S.