Automated Loading Operation for Mass-Production Hydraulic Excavators by Nonlinear Model Predictive Control

Abstract

This study deals with the control methods for automation of the loading operation of hydraulic excavators for mass production. In the loading operation, it is necessary to move the bucket to the target position without spilling soil from the bucket. Since the loading operation is a combined operation of the front equipment and the swing operation, it is not easy to generate the ideal trajectory. We apply Model Predictive Control (MPC) to this problem and investigate a method to realize ideal loading operation by giving only the coordinates of the loading position. When using MPC, the challenge is that a lot of worker-hours are spent on tuning the weights of the objective function. We also propose an efficient weight tuning method to solve this problem, with a view to adapting it to hydraulic excavators for mass production. We have confirmed the effectiveness of the proposed method through numerical simulations.