A study of locomotive driver's seat vertical suspension system with adjustable damper

Abstract

This paper shows that laboratory measurements can be used for the identification of structure and parameters of commercial seat vertical suspension system model. A commonly used single-degree-of-freedom suspension model does not suffice. The system model presented is based on Zener's structure and clearly describes the dynamic properties of a vertical seat suspension with an adjustable damper. The model introduced, augmented with seat cushion dynamic model, predicts the seat vertical vibration mitigation properties under field conditions with a reasonable accuracy. Optimisation of the adjustable damper setting is performed using a two-objective function optimisation technique. This enables us to optimise not only the exerted vertical vibration acceleration but also the seat relative vertical displacement (stroke). Optimisation was facilitated for the particular suspended seat without the requirement of further field measurements. In addition, a two-parameter optimisation was performed showing possible further improvement in both objectives at the manufacturer's discretion. This study could be representative of driver's seats equipped with vertical seat suspension system using an air-spring and an adjustable damper.

Keywords:

• driver's seat
• vertical suspension system
• adjustable damper
• vertical vibration mitigation
• suspension stroke reduction

Acknowledgements

This work has been conducted within Grant No. 2/6161/26 of the Slovak VEGA Grant agency, using information gathered during performing the 5th Framework programme RTD project with acronym VIBSEAT, funded by the European Commission (Contract No. G3RD-CT-2002-00827) and coordinated by Professor Michael J. Griffin of the Human Factors Research Unit (HFRU) of ISVR, Southampton University, UK. The support of both agencies is gratefully acknowledged, as well as efficient and fruitful collaboration with VIBSEAT project partners HFRU ISVR, Southampton University, UK, and SNCF CIM SME 1 Unit, Le Mans, France.