(Dr. Andrea Upmann, Ford-Werke GmbH Cologne and Dipl.-Math. Jessica Rausch, Ford Research & Innovation Center Aachen, 29. November, 2018 )
Comfort is an important factor in product buying decisions. Therefore, vehicle manufacturers aim to develop ergonomic vehicles that minimize occupants’ discomfort. The handbrake is an essential control in vehicles. This work provides the first demonstration that the perceived discomfort of the handbrake application can reliably be predicted based on postural, biomechanical and mathematical modelling.
In two studies, 117 and 40 subjects, respectively, rated the discomfort for several handbrake variants while their motion was recorded. Afterwards, the handbrake application was modeled in the Digital Human Modeling software RAMSIS and the biomechanical software AnyBody Modeling System. Calculated biomechanical parameters included joint reactions, joint muscle moment measures, muscle activities, joint angles as well as metabolic power and energy. Stepwise regression was applied to develop a prediction model for discomfort. The herewith calculated discomfort was well in line with the subjects’ ratings.
As a result, a user-friendly procedure has been proposed to quantify handbrake discomfort with DHMs, which are typically available in automotive development. This method can be applied at early stages of the automotive development to enhance the ergonomics of the vehicle interior. It allows for increasing efficiency and objectivity as well as for saving resources and budget.
Andrea and Jessica will provide an insight into the multi-step study detailed in Andrea’s dissertation. The project was enabled in cooperation between three Ford departments and the Institute of Biomechanics and Orthopedics at the German Sport University Cologne.