THE DYNAMICS OF A WHEEL LOADER IN MOTION CONSIDERING RANDOM ROAD SURFACE IRREGULARITIES

Abstract

Wheel loaders are among the most widely used and popular construction machinery today. During operation, road surface irregularities significantly influence the vibrations of the wheel loader. This article investigates the dynamic model of a wheel loader in motion, considering the random roughness profile of the road surface. The inverse Fourier transform (IFT) method, based on the power spectral density (PSD) of the road surface, is employed to simulate road surface roughness. The developed dynamic model accounts for the elasticity and damping properties of the tires, the suspension system, and the hydraulic lift cylinder of the boom mechanism. Based on the dynamic model, the Lagrange equations of the second kind are applied to derive the system's differential equations of motion. The study results indicate that when the loader operates on a Class C road at a speed of 4.7 m/s, the base acceleration is less than 0.5 m/s², meeting the ISO 2631-1 standards for vibration exposure to operators. The findings of this research provide a basis for assessing the stability of wheel loaders and serve as a foundation for designing and improving suspension systems for these machines.