Repeatability test of seat and steering wheel adjustment in a coach seating buck

Objective: The purpose of this study is testing repeatability of seat adjustment in a coach seating buck. Background: Lots of research has been conducted using vehicle seating buck for ergonomic design of vehicle cockpit. When conducting seat and steering wheel adjustment experiment using seating buck, it is important issue whether subjects were able to adjust seat and steering wheel repeatedly or not. However, few researches have focused on repeatability test of seat and steering wheel adjustment in a coach seating buck unlike with sedans although there are differences between sedan cockpit and coach cockpit. Method: 10 coach drivers adjusted forward-backward location of seat, seat height, seatback angle, steering wheel height and steering wheel depth three times to a comfortable position in a coach seating buck, and then data were measured. There was sufficient time interval between every adjustment. Results: Repeatability value and intraclass correlation (ICC) were calculated for all measures to test repeatability. Forward-backward location of seat, seatback angle, steering wheel height and depth showed high ICC and low repeatability value. On the other hand, seat height showed low ICC and high repeatability value. Conclusion: As a result of this study, forward-backward location of seat, seatback angle, steering wheel height and depth showed high repeatability, and seat height showed low repeatability. This means that drivers were insensitive to change of seat height. Application: The result of this study can be used for further studies about coach cockpit design.