Mathematical Model of Cabin With Suspension System to Analyze its Oscillatory Stability During Vehicle Movement

This research focuses on the development of a methodology for the analysis of nonlinear oscillations of a vehicle cab with a suspension system. When designing vehicles with cab suspension systems, it is important to align their operation with other vehicle modules and systems that collectively ensure the required comfort and dynamic parameters and prevent resonant oscillations in the cab. A vehicle cab is a dynamic system with 6 degrees of freedom, therefore its oscillations are spatially complex and feature energy direction switching. Thus, the problems of suspended cab dynamics should be solved in a non-linear spatial setting that can account for oscillation energy redistribution between various spatial direc-tions. The purpose of this work is to develop a mathematical model for the spatial oscillations of a suspended cab relative to the vehicle undercarriage that can help analyze the non-linear oscillations that occur in the cab to study their stability during vehicle movement. This study helped identify the adverse frequency ratios for the disturbing impact on the can suspension system that can reduce cab comfort and result in the instability of its oscillations. The authors developed methods to reduce the amplitudes of suspended cab sway when its spatial oscillations are unstable. The developed methods and mathematical model help identify and prevent resonant spatial phenomena in the cab at all stages of designing vehicle cab suspension systems. The authors proposed specific solutions to design cab suspension systems to improve cab comfort and reduce cab sway, including the usage of air bellows that can form progressive non-linear load characteristics and controllable hydraulic dampers that can increase the damping coefficient in the cab suspension system during cab sway.