Dragline excavation simulation, real-time terrain recognition and object detection

The contribution of coal to global energy is expected to remain above 30% through 2030. Draglines are the preferred excavation equipment in most surface coal mines. Recently, studies toward dragline excavation efficiency have focused on two specific areas. The first area is dragline bucket studies, where the goal is to develop new designs which perform better than conventional buckets. Drawbacks in the current approach include operator inconsistencies and the inability to physically test every proposed design. Previous simulation models used Distinct Element Methods (DEM) but they over-predict excavation forces by 300% to 500%. In this study, a DEM-based simulation model has been developed to predict bucket payloads within a 16.55% error. The excavation model includes a novel method for calibrating formation parameters. The method combines DEM-based tri-axial material testing with the XGBoost machine learning algorithm to achieve prediction accuracies of between 80.6% and 95.54%. The second area is dragline vision studies towards efficient dragline operation. Current dragline vision models use image segmentation methods that are neither scalable nor multi-purpose. In this study, a scalable and multi-purpose vision model has been developed for draglines using Convolutional Neural Networks. This vision system achieves an 87.32% detection rate, 80.9% precision and 91.3% recall performance across multiple operation tasks. The main novelty of this research includes the bucket payload prediction accuracy, formation parameter calibration and the vision system accuracy, precision and recall performance toward improving dragline operating efficiencies --Abstract, page iii

Multi-Agent Systems

A multi-agent system (MAS) is a system composed of multiple interacting intelligent agents. Multi-agent systems can be used to solve problems which are difficult or impossible for an individual agent or monolithic system to solve. Agent systems are open and extensible systems that allow for the deployment of autonomous and proactive software components. Multi-agent systems have been brought up and used in several application domains

Utility of construction automation and robotics in South Africa

The construction industry demands active construction organisation, efficient construction processes and innovative construction techniques to effectively compete under increasing market competition and technological advancements in the twenty first century. The problems associated with construction, such as poor quality and slow productivity, labour shortages, occupational health and safety, and inferior working conditions, have opened the possibility of more revolutionary solutions within the industry. One such solution espoused as having tremendous potential to improve construction productivity whilst alleviating the problems associated with construction is Construction Automation and Robotics. Automation and robotics technologies encompass a wide range of innovative technologies using technologically advanced machinery to improve the speed and efficiency of a given process. The aim of this study is to analyse the extent of utility of construction automation and robotics in the South African construction industry. The research adopted the quantitative methodology and online survey to collect data. A detailed quantitative (statistical) data analysis was performed, using web-based software “QuestionPro,” including data analysis for investigating possible relationships between variables. Through this study it has been established that one of the prospective solutions to the problems associated with construction is in the implementation and utility of innovative technologies in construction such as automation and robotics. Moreover, the research found that automation and robotics in South Africa is at an interesting point whereby organisations are taking strides in accepting and implementing the technologies. It is envisaged that the utility of construction automation and robotics would improve the industry in terms of productivity, health and safety and quality

The Role of Silk in the Behaviour and Sociality of Spiders

This article describes the links between the production of silk by spiders and their behaviour. Silk allows the spider to change its physical environment, which in turn leads to behavioural changes and impacts in the new environment. The feedback between silk and the animal producer can explain the architecture of spider webs and their adaptation to the environment, by referring only to stereotypic stimulus-response reactions without necessarily resorting to a “representation” by the animal of the structure it builds. Silk can act as a means of protection against environmental stress, a snare for prey, a means of locomotion, and also as support for chemical signals or to act as a vector of vibratory signals. These last two functions have undoubtedly played a key role in spider socialization and explains the phenomena of group cohesion, collective decision making, and the coordination of activities, without resorting to mental “representations” for the overall situation. The bulk of this review describes silk as the chief agent directing the construction of traps, communication, social cohesion, and cooperation amongst its producers

Advances in raw material industries for sustainable development goals

"""Advances in Raw Material Industries for Sustainable Development Goals"" presents the results of joint scientific research conducted in the context of the Russian-German Raw Materials Forum. Today Russia and Germany are exploring various forms of cooperation in the field of mining, geology, mineralogy, mechanical engineering and energy. Russia and Germany are equally interested in expanding cooperation and modernizing the economy in terms of sustainable development. The main theme of this article collection is connected with existing business ventures and ideas from both Russia and Germany. In this book the authors regard complex processes in mining industry from various points of view, including: - modern technologies in prospecting, exploration and development of mineral resources - progressive methods of natural and industrial mineral raw materials processing - energy technologies and digital technologies for sustainable development - cutting-edge technologies and innovations in the oil and gas industry. Working with young researchers, supporting their individual professional development and creating conditions for their mobility and scientific cooperation are essential parts of Russian-German Raw Materials Forum founded in Dresden 13 years ago. This collection represents both willingness of young researchers to be involved in large-scale international projects like Russian-German Raw Material Forum and the results of their long and thorough work in the promising areas of cooperation between Russia and Germany.

Correlations between physical and structural properties of spider silk - Correlaties tussen fysische en structurele eigenschappen van spinnenzijde

Spinnen produceren tot zeven verschillende draden met opmerkelijke mechanische eigenschappen. Als gevolg hiervan is er de laatste jaren veel interesse ontstaan in het ontwerp van deze materialen voor de ontwikkeling van nieuwe proteïne-gebaseerde polymeren. Daarvoor is het vereist om de relaties tussen structuur en eigenschappen te verstaan. De bedoeling van dit doctoraatsonderzoek is om daartoe bij te dragen door het bestuderen van deze relaties voor twee types spinnenzijdes (eizak- en “dragline” spinnenzijde) in vergelijking met zijdes afkomstig van twee rupsen Bombyx mori (of gewone zijde) en Antheraea pernyi (Tussah of wilde zijde). Tijdens dit onderzoek werd vastgesteld dat eizakspinnenzijde een totaal ander mechanisch gedrag vertoont dan de overige zijdes, o.m. de dragline spinnenzijde. Gezien de literatuur zeer beperkt is over dit type spinnenzijde, werd gekozen om de focus dan ook op dit type zijde te leggen. Naast het rek-sterkte gedrag werd ook het visco-elastisch gedrag, meer bepaald het elastisch en kruipgedrag, bestudeerd. De secundaire structuur werd geanalyseerd aan de hand van Fourier-transformatie infraroodspectroscopie (FT-IR) en vastestof nucleaire magnetische resonantie (NMR) spectroscopie. Verder werd ook het thermisch gedrag bestudeerd aan de hand van thermogravimetrie (TGA) en thermische mechanische analyse (TMA). Uit het bekomen structuuronderzoek werd voor eizakspinnenzijde een structureel model afgeleid dat zijn fysische eigenschappen kan verklaren. De structuur van eizakspinnenzijde wordt gedomineerd door een uitgestrekte amorfe faze met verbonden “-turn” structuren. De kristallijne faze is beperkt en bestaat uit korte “-sheet” structuren. Beide fazen zijn verder gegroepeerd tot een niet-fibrillaire kern-mantel structuur

A stochastic method for representation, modelling and fusion of excavated material in mining

The ability to safely and economically extract raw materials such as iron ore from a greater number of remote, isolated and possibly dangerous locations will become more pressing over the coming decades as easily accessible deposits become depleted. An autonomous mining system has the potential to make the mining process more efficient, predictable and safe under these changing conditions. One of the key parts of the mining process is the estimation and tracking of bulk material through the mining production chain. Current state-of-the-art tracking and estimation systems use a deterministic representation for bulk material. This is problematic for wide-scale automation of mine processes as there is no measurement of the uncertainty in the estimates provided. A probabilistic representation is critical for autonomous systems to correctly interpret and fuse the available data in order to make the most informed decision given the available information without human intervention. This thesis investigates whether bulk material properties can be represented probabilistically through a mining production chain to provide statistically consistent estimates of the material at each stage of the production chain. Experiments and methods within this thesis focus on the load-haul-dump cycle. The development of a representation of bulk material using lumped masses is presented. A method for tracking and estimation of these lumped masses within the mining production chain using an 'Augmented State Kalman Filter' (ASKF) is developed. The method ensures that the fusion of new information at different stages will provide statistically consistent estimates of the lumped mass. There is a particular focus on the feasibility and practicality of implementing a solution on a production mine site given the current sensing technology available and how it can be adapted for use within the developed estimation system (with particular focus on remote sensing and volume estimation)

Magnetic Hybrid-Materials

Externally tunable properties allow for new applications of suspensions of micro- and nanoparticles in sensors and actuators in technical and medical applications. By means of easy to generate and control magnetic fields, fluids inside of matrices are studied. This monnograph delivers the latest insigths into multi-scale modelling, manufacturing and application of those magnetic hybrid materials