Robust Model-Free Path Tracking Algorithm for Hydraulic Center-Articulated Scooptrams

Abstract

This paper proposes a model-free steering control method to address the path tracking challenges of Hydraulic Center-articulated Scooptrams (HCS) in narrow underground mining environments. Due to the nonlinear and time-delay characteristics of the hydraulic steering system, the HCS exhibits response lag when executing control commands. The lag time demonstrates dynamic uncertainty influenced by operating conditions, hydraulic pressure, and load variations. To address this challenge, an adaptive steering control strategy is designed. This strategy leverages the geometric relationship between the HCS and the reference path to dynamically adjust the look-ahead distance, thereby compensating for the uncertainty caused by the hydraulic system lag. Additionally, the error is mapped to the actual control input in real-time through a feedback error controller, effectively correcting control errors caused by lag without relying on a complex hydraulic system model. The proposed method was experimentally validated in a full-scale simulated mining tunnel, demonstrating considerable robustness and precise path tracking performance under uneven terrain, heavy loads, significant initial error, and bidirectional movement. This method provides a viable solution for the autonomous navigation of the HCS.