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Performance Analysis of Drive‐Line Steering Methods in Excavator‐Mounted Sheet‐Piling Systems
Author(s) -
Keskinen Erno,
Launis Sirpa,
Cotsaftis Michel,
Raunisto Yrjö
Publication year - 2001
Publication title -
computer‐aided civil and infrastructure engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.773
H-Index - 82
eISSN - 1467-8667
pISSN - 1093-9687
DOI - 10.1111/0885-9507.00228
Subject(s) - excavator , control theory (sociology) , actuator , kinematics , workspace , hydraulic machinery , hydraulic cylinder , trajectory , engineering , synchronizing , control engineering , computer science , simulation , robot , mechanical engineering , topology (electrical circuits) , physics , control (management) , electrical engineering , classical mechanics , astronomy , artificial intelligence
Sheet‐piling processes pose the problem of guiding the pile to follow a fixed trajectory in order to drive it correctly into the ground. Since the complete system consists of the supporting excavator boom with hydraulic actuators, the gripper, and the vibratory unit, the large number of system variables implies the use of servo control to allow a human operator to handle the operation. An exact inverse kinematic transformation from Cartesian workspace to boom joint space variables allows the pile penetration to be guided, keeping the valve input of the main boom actuator as the free parameter, while the remaining actuators are governed automatically by the control computer. The penetration record of the pile differs based on whether a constant valve input is used in semiautomatic steering mode or, alternatively, the desired penetration speed is governing the valve input in a feedback loop in full‐automatic steering mode. A numerical model representing an actual industrial system has been developed. Variable results from computer simulations have led the manufacturer to realize the steering system. It has been verified in real piling tests that the steering system may be tuned to be stable and fast enough for practical working conditions. In particular, the performance of trajectory control in terms of tracking error is much better than in the conventional manual steering method, as expected.