MEMOSIK V—An active dummy for determining three-directional transfer functions of vehicle seats and vibration exposure ratings for the seated occupant

In collaboration with some of the German automotive industry OEMs, an active vibration dummy called MEMOSIK V, was defined in response to their specific requirements for vibration comfort. The topics described in this paper shall deliver an insight into a selection of the development phases of this development project.

An active, three-dimensional vibration dummy is described with the newly developed MEMOSIK V, which simulates the human dynamic behavior by reproducing an equivalent dynamic mass. This vibration dummy qualifies for replacing the occupant as a test object and measuring instrument and allows the objective and repeatable measurement of the vibration transmission from the vehicle base to the buttocks and the back through the vehicle seat.

Based on extensive measurements of the dynamic mass of the sitting man in the fore-and-aft, the lateral and the vertical direction, the objective functions of the vibration dummy are deduced through a modal identification approach. By integrating these parameterized functions in the control system, the dynamic behavior of the dummy can be adapted to the mass percentiles F05, M50 and M95, as well as to individual people by the software managed modification of the controller setup. The variation in posture is guaranteed for the complete design range of passenger car and commercial vehicle seats. The integrated measurement system permits the objective and repeatable rating of the human exposure ISO 2631-1, 1997. Mechanical vibration and shock—evaluation of human exposure to whole-body vibration—general requirements] as well as the evaluation of seat transfer functions considering all three directions in space, both on simulator platforms and in mobile use on the road.

Relevance to the industry

Considering the rating of seating and vibration comfort, the automotive industry has to meet the challenge to establish a relationship between the subjective comfort sensation and the objective and measurable physical quantities. Hence, the demand for a measurement system that makes it possible to acquire, reproduce and comprehend the circumstances that define seating and vibration comfort is great and ascending continuously.