A study on the HMI assessment of a joy stick driving system using driver workload measurements

Recently, vehicle driving devices to support infotainment services are being designed for driver’s convenience. Especially, the automobile industry is developing vehicles that use a joy stick instead of a steering wheel from the concept car. The greatest strength of using a joy stick is that the driver feels less workload and fatigue than when using a steering wheel. However, this field still needs more research and experiments for more accurate results. Therefore, this study evaluated the workload when driving with different devices through a subjective questionnaire and measurement of physiological signals. The reason for using not only a survey but also physiological signals is to support the results of the subjective questionnaire, which are not enough to yield accurate results. There are two different kinds of methods to carry out this research: SWAT (subjective workload assessment technique) for the survey and Biopac equipment for the measurement of physiological signals. A thermal infrared camera is used for capturing the driver workload by measuring the facial skin temperature. Furthermore, a previously established driving simulator, GPS (global positioning system), and the virtual Kyeong-Bu highway are used for the experiment. As a result of the experiment with 13 subjects following both methods (the surveys and the measurement of physiological data), it is confirmed that using a drive stick device causes less workload and fatigue to the drivers than using a steering wheel. In addition, the statistical significance of the results is verified through the SPSS (statistical package for the social sciences) statistical analysis program.