Abstract
In this research, the linkage mechanism of hydraulic excavator which contains the closed loops is modeled based on the Newton-Euler formulation, and the motion equation is derived. Moreover, we apply a soil model for simulation, based on the two dimensional distinct element method (DEM), in order to reproduce reaction force from grounds. These models are integrated and able to analyze detailed interaction between machine and ground. The hydraulics force is analyzed, when an excavator performs digging operations according to the preprogramed digging trajectory. We conduct inverse-dynamics analysis to estimate the influence of digging resistance force on generative cylinder forces. The simulation results show that cylinder generative forces, varying depending on digging reaction force, significantly influence the cylinder force during digging operations.
