Establishment of Optimized Digging Trajectory for Hydraulic Excavator

Abstract

Efficiency of digging operation of hydraulic excavator is affected by the geometry of digging trajectory. To improve the operation efficiency, appropriate trajectory design is important. In this report, we developed a simulation model to establish optimized trajectories. This model involves a soil and a front linkage model of an excavator. A Distinct Element Method (DEM) is adopted for the soil model. The DEM is able to describe soil behavior during digging operation and to estimate digging soil volume and load quantitatively. Generative force and energy consumption of hydraulic cylinders are calculated by the kinematic model which solves inverse dynamics of front linkage of hydraulic excavators. Geometric shapes of the trajectory are determined with some trajectory parameters in this study. Using these generated trajectories and the simulation model, consumed energy and digging soil volume of every trajectory is calculated. Analyzing these results, the optimal digging trajectory is established. Effectiveness of the optimized trajectory is validated by comparing with a skilled operator’s digging trajectory which is reproduced on the simulation. In addition, efficient trajectory for horizontal ground is established by using this developed simulation model.