Development and Analysis of a Multibody Dynamics Suspension Air Spring Model as a Function of Sprung Mass, Un-Sprung Mass, and Design Height

Air spring systems are challenging to mathematically model due to the complexity of their nonlinear dynamic characteristics. Numerous air spring mechanical and thermodynamic models have been proposed, but this study focused on the development and analysis of a new thermodynamic air spring model under a polytropic thermodynamic process that could accurately represent the force output in a multibody dynamics (MBD) virtual suspension subsystem. This model considered function inputs of sprung mass, un-sprung mass, and design height to efficiently generate updated air spring properties for new vehicle configurations, specifically for a self-propelled sprayer application. After this model was validated against physical ground-truth sensor data, it was utilized in a sensitivity study to experimentally test an alternative air spring component and to understand the resulting performance effect on an operator comfort key performance indicator.