Design of an active vibration dummy of sitting man

Abstract

Objective. The determination of vibration transmission through vehicle seats today is still performed with small groups of test subjects. This method suffers from several severe disadvantages, in particular poor repeatability and objectivity due to varying test conditions and limited group sizes. Replacing test persons with a vibration dummy helps to solve this problem. Design. The active vibration dummy simulates the dynamic behaviour of sitting man expressed in terms of the driving point impedance for arbitrary body masses and excitation signals. Methods. The dummy is realized as a mechatronic system basing on a single degree of freedom setup. A real-time control loop of mass accelerations (and thus acting forces) fits the active dummy to the desired driving point impedance data set. Model and controller parameters are determined by a parameter-identification technique giving meaningful results for arbitrary impedance data sets. Results. The prototype shows excellent agreement with the target data under laboratory conditions. Body mass and excitation level can be varied over the full range of car seat test requirements. Relevance The determination of vibration transmission through vehicle seats should be possible without human experiments. An active vibration dummy with adjustable vibration behaviour expressed by the vertical driving point impedance covering the entire scope of car seat tests (masses/excitation intensities) is presented. With the dummy, improved seat test procedures could be established, leading to design improvements and therefore to prevention of whole-body vibration injuries. © 2001 Elsevier Science Ltd. All rights reserved.