An applicability assessment of excavation tools for small-scale mining robots

Research output: ThesisDoctoral Thesis

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Abstract

The modern mining industry faces increasing challenges related to sustainability and raw material shortage that require additional efforts in research and development. A significant trend in underground mining is the movement towards zero personnel, which demands the full mechanization and subsequent automation of the mining process up to the use of fully autonomously operating robots. Future mining robots will require adapted excavation technologies to be capable of mining raw materials with less power and lower masses. A review of excavation technologies has been conducted in order to perform preliminary evaluations of their potential applicability. Moreover, performance parameters such as the excavation rate and specific energy but also the expectable reaction forces have been estimated by using theoretical approaches on the example of a robot with a mass of 1500 kg. The thesis is further discussing the predictability of the cutting forces of small, longitudinal part-face cutter heads in soft rock conditions. This includes a review of theoretical rock cutting models for estimating the cutting force of conical pick tools, experimental tests of a small, longitudinal part-face cutter head and assessing the applicability of single-pick rock cutting models to full-scale cutting operations. Experimental cutting tests of specimens with three different rock strengths (UCS = 16, 23 and 30 MPa) have been conducted successfully and the obtained results were taken to develop a sophisticated modelling approach to predict the cutting forces. Due to the comparatively small dimensions of the conical pick tools, major deviations between the single-pick cutting force models and measurement results could be found. Consequently, a dynamic model has been developed which is capable of including the kinematics of the pick cutting depth in the cutting force prediction. By a combination of the two new approaches, the cutting operation of a longitudinal part-face cutter head can be simulated. The results are highly satisfactory and showed a mean relative deviation of 7.2 % between the measured and simulated total cutting forces. Eventually, conceptual designs of selected excavation technologies were developed that might be used in future works. These include three individual rock drilling systems, a part-face cutting tool, a high-pressure waterjet cutting tool and a hydrofracturing tool. The proposed concepts shall not be considered as full-fledged designs but shall provide a basis for future excavation systems of small-scale mining robots.
Translated title of the contributionEine Anwendbarkeitsanalyse von Abbauwerkzeugen für kleinmaßstäbige Bergbau-Roboter
Original languageEnglish
QualificationDr.mont.
Awarding Institution
  • Montanuniversität
Supervisors/Advisors
  • Sifferlinger, Nikolaus August, Supervisor (internal)
  • Rückert, Elmar, Assessor A (internal)
  • Antretter, Thomas, Co-Supervisor (internal)
  • Drebenstedt, Carsten, Assessor B (external), External person
DOIs
Publication statusPublished - 2023

Bibliographical note

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Keywords

  • Mining
  • heavy-duty engineering
  • robotics

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