Dynamic Analysis of Car Ingress/Egress Movement: an Experimental Protocol and Preliminary Results

This paper focuses on full body dynamical analysis of car ingress/egress motion. It aims at proposing an experimental protocol adapted for analysing joint loads using inverse dynamics. Two preliminary studies were first performed in order to 1/define the main driver/car interactions so as to allow measuring the contact forces at all possible contact zones and 2/identify the design parameters that mainly influence the discomfort. In order to verify the feasibility of the protocol, a laboratory study was carried out, during which two subjects tested two car configurations. The experimental equipment was composed of a variable car mock-up, an optoelectronic motion tracking system, two 6D-force plates installed on the ground next to the doorframe and on the car floor, a 6D-Force sensor between the steering wheel and the steering column, and two pressure maps on the seat. Motions were reconstructed from measured surface markers trajectories using inverse kinematics. Joint loads were calculated by an inverse dynamic approach using a recursive Newton-Euler procedure. The validation of the computing method and the relevance of a dynamic approach are also discussed.