Trajectory Generation for a Hydraulic Mini Excavator using Nonlinear Model Predictive Control

摘要

Autonomous excavators have great potential to improve safety and to increase productivity. A common task for an excavator is to grade. Considering an autonomous grading system, a basic requirement is to perform straight line movements of the tool-center-point in the cartesian space. In this paper, a nonlinear model predictive controller is used to generate straight line trajectories of the tool-center-point considering actuator constraints. The performance is verified using a validated physical simulation model. The results show that the tool-center-point follows straight lines between the desired points without violating the constraints. Furthermore, the resulting trajectories are near time-optimal.