High Precision Hydraulic Excavator Control for Heavy-Duty Grading

2026-05-10

AI Summary

This study addresses the challenge of achieving high-precision autonomous control across different hydraulic architectures—specifically load-sensing and negative-flow systems—in heavy-duty grading operations. The authors propose a hierarchical autonomous controller comprising a hydraulics-aware low-level control loop and a high-level path-tracking coordination algorithm, unified through a cross-architecture calibration technique. This approach enables consistent, high-accuracy grading performance on both mainstream hydraulic systems while effectively leveraging maximum system pressure to prevent premature actuator stalling. Experimental validation on two heterogeneous excavators demonstrates a root-mean-square error (RMSE) of 1.8 cm in grading accuracy, representing a 2.6-fold improvement over commercial solutions (4.7 cm RMSE), along with significantly enhanced operational efficiency.

Abstract

High-precision heavy-duty grading is a common step in earthworks, traditionally carried out manually by skilled operators. Removing a significant amount of material while achieving a high-precision surface requires substantial machine-specific experience. Different hydraulic architectures react differently to operator inputs and soil interaction forces, which makes generalizable controllers challenging. In this paper, we present an autonomous controller that achieves high-precision grading at expert-operator speed on Load Sensing and Negative Flow Control machines alike. We split our controller into two parts: (1) a hydraulic-aware low-level loop that is hydraulic architecture-specific and (2) a path-tracking layer that coordinates joint motions and responses. Through a calibration process, our technique is applicable to load-sensing and negative-flow-control machinery. To showcase its versatility, we benchmark our approach on two excavators with different hydraulics and compare it against a commercial state-of-the-art solution. Our technique (RMSE 1.8~cm) outperforms the commercial solution (RMSE 4.7~cm) in precision by a factor of 2.6 and improves machine usage by leveraging the maximum function pressure, as opposed to commercial solutions that stall prematurely.

Problem

• high-precision grading
• hydraulic excavator
• autonomous control
• hydraulic architecture
• earthworks

Innovation

• autonomous excavation
• hydraulic-aware control
• high-precision grading
• load-sensing hydraulics
• negative flow control