DEVELOPMENT OF AN AUTONOMOUS NAVIGATION SYSTEM FOR THE SHUTTLE CAR IN UNDERGROUND ROOM & PILLAR COAL MINES

In recent years, autonomous solutions in the multi-disciplinary field of the mining engineering have been an extremely popular applied research topic. The growing demand for mineral supplies combined with the steady decline in the available surface reserves has driven the mining industry to mine deeper underground deposits. These deposits are difficult to access, and the environment may be hazardous to mine personnel (e.g., increased heat, difficult ventilation conditions, etc.). Moreover, current mining methods expose the miners to numerous occupational hazards such as working in the proximity of heavy mining equipment, possible roof falls, as well as noise and dust. As a result, the mining industry, in its efforts to modernize and advance its methods and techniques, is one of the many industries that has turned to autonomous systems. Vehicle automation in such complex working environments can play a critical role in improving worker safety and mine productivity. One of the most time-consuming tasks of the mining cycle is the transportation of the extracted ore from the face to the main haulage facility or to surface processing facilities. Although conveyor belts have long been the autonomous transportation means of choice, there are still many cases where a discrete transportation system is needed to transport materials from the face to the main haulage system. The current dissertation presents the development of a navigation system for an autonomous shuttle car (ASC) in underground room and pillar coal mines. By introducing autonomous shuttle cars, the operator can be relocated from the dusty, noisy, and potentially dangerous environment of the underground mine to the safer location of a control room. This dissertation focuses on the development and testing of an autonomous navigation system for an underground room and pillar coal mine. A simplified relative localization system which determines the location of the vehicle relatively to salient features derived from on-board 2D LiDAR scans was developed for a semi-autonomous laboratory-scale shuttle car prototype. This simplified relative localization system is heavily dependent on and at the same time leverages the room and pillar geometry. Instead of keeping track of a global position of the vehicle relatively to a fixed coordinates frame, the proposed custom localization technique requires information regarding only the immediate surroundings. The followed approach enables the prototype to navigate around the pillars in real-time using a deterministic Finite-State Machine which models the behavior of the vehicle in the room and pillar mine with only a few states. Also, a user centered GUI has been developed that allows for a human user to control and monitor the autonomous vehicle by implementing the proposed navigation system. Experimental tests have been conducted in a mock mine in order to evaluate the performance of the developed system. A number of different scenarios simulating common missions that a shuttle car needs to undertake in a room and pillar mine. The results show a minimum success ratio of 70%

Requirements elicitation interviews and applications for an underground remote-piloted aerial system

Abstract: Being underground is dangerous, it really is. People shouldn’t go there if they don’t need to, especially in an age where driverless cars by Google and shopping delivery by Amazon are on the brink of implementation in unstructured public environments; but held up, not by technology, but by wrangling about legislation covering liability determination, and fears of hacking drive-by-wire systems. Underground mining is a secure (from an IT perspective), structured, and predictable environment with limited and controlled human access – an ideal place for automated or remotely piloted systems. This paper outlines the semi-structured interview process that was executed to determine the requirements for an underground remotely piloted aerial system (URPAS). The potential applications are explored; including search and rescue, the business-orientated activity of regularly scanning rockpasses to predict and prevent blockages, and scanning a blocked rockpass to determine the blockage location and structure. An even more ’out-of-the-box’ application, using the vehicle to deliver explosives to the underside of a blockage, was included in the brainstorming discussions. Interviews with ten mining and unmanned aerial systems experts were conducted with a questionnaire as the primary data collection tool. The questionnaires were analysed to determine the representatively of the sample set, and therefore the validity of the gathered data, based upon expertise ratings in each of the relevant areas of knowledge: mining, surveying and mapping, and remote-piloted aerial systems. The goal was to identify the key performance requirements of a U-RPAS, and determine the feasibility of such a system being developed. A specialized company providing a scanning service emerged the preferred implementation method, and the rationale for this choice is presented. As context, the sub-system prototypes used in the brainstorming section of the interviews are presented, as are the implementation scenarios discussed in the interviews. It is thus shown that this method of requirements elicitation is suitable for this type of technology implementation project

Multi-function intelligent robotic in metals detection applications

Recent technologies for robotics have been offered an effective and efficient solution to safeguard workers from risks in their work environments. These risks involve radioactive, toxic, explosive and mines. In this paper, design and implement computer robot based on metal detection as well as avoiding obstacles automatically. The proposed wireless controlled robotic vehicle can be used in metal detection applications such as landmine detection, obstacles avoidance, selecting best routing without imposing human's harms and workforce aspects. The robotic wheel can sense the obstacles that positioning at ahead of its path, and also avoids the obstacles forward, left and right of its routes. The robot is controlled by using Bluetooth wireless communication to interface between the controller and the implemented robot. Furthermore, sensor IR (FC-03) for the metal detector and used ultrasonic sensor (HC-SR04) for objects or obstacles sensing. The presented controlled robotic designed for desert and dry soil that can replace the human role in avoiding obstacles and metal detection capabilities. The produced robot was useful due to it can detect metals and avoiding obstacles consecutively besides it was effective to select the best route based on the intelligent technique that adopted, the predefined metals by using an intelligent decision maker for route finder in a flat surface environment

CONCEPTS FOR DEVELOPMENT OF SHUTTLE CAR AUTONOMOUS DOCKING WITH CONTINUOUS MINER USING 3-D DEPTH CAMERA

In recent years, a great deal of work has been conducted in automating mining equipment with the goals of increasing worker health and safety and increasing mine productivity. Automating vehicles such as load-haul-dumps been successful even in underground environments where the use of global positioning systems are unavailable. This thesis addresses automating the operation of a shuttle car, specifically focusing on positioning the shuttle car under the continuous miner coal-discharge conveyor during cutting and loading operations. This task requires recognition of the target and precise control of the tramming operation because a specific orientation and distance from the coal discharge conveyor is needed to avoid coal spillage. The proposed approach uses a stereo depth camera mounted on a small-scale mockup of a shuttle car. Machine learning algorithms are applied to the camera output to identify the continuous miner coal-discharge conveyor and segment the scene into various regions such as roof, ribs, and personnel. This information is used to plan the shuttle car path to the continuous miner coal-discharge conveyor. These methods are currently applied on 1/6th scale continuous miner and shuttle car in an appropriately scaled mock mine

Characteristics of ultrasonic ranging sensors in an underground environment

"Ultrasonic ranging sensors are inexpensive, have no moving parts, have no lenses to clean, are normally small and unobtrusive, and can measure distances through moderate amounts of dust, smoke, and humidity, so they are well suited to underground mines. In the work reported here, conducted by the U.S. Bureau of Mines, researchers tested ultrasonic ranging sensors for their abiity to define rib line features for computer-aided navigation of underground mine mobile equipment.The investigation began with laboratory tests of field of view, angle of incidence, intersensor variation, and ranging accuracy of the individual rangers in a ring array produced by Denning Robotics of Wilmington, MA. The results showed that the sensors have good accuracy and low variability. Additional experiments at AMAX's Henderson Mine showed the sensors could accurately and reliably measure the distance to mine features, including convex and concave corners and rib intersections. The results showed that when used properly, the ranger data are accurate enough for reliable mine vehicle navigation. When used incorrectly, ultrasonic rangers do not provide the anticipated data. Therefore, this report explains the principles of ultrasonic range measurement, describes the ranger's strenghts and weaknesses, and explains proper ranger use and data analysis." - NIOSHTIC-2NIOSHTIC no. 1000318

UAV-BASED GEOTECHNICAL MODELING AND MAPPING OF AN INACCESSIBLE UNDERGROUND SITE

Digital photogrammetry is becoming a more common method used for mapping geological and structural rock mass features in underground mining. The issue of capturing geological and structural data in inaccessible, unsupported areas of mines remains even when utilizing terrestrial photogrammetric methods; thus, geotechnical models of mines are left with incomplete datasets. Large unsupported underground voids, like stopes, have the potential to cause major failures, but by filling in the geotechnical data gaps in inaccessible areas, potential failures can be predicted through kinematic analysis of the area’s mapped discontinuities. Implementation of Unmanned Aerial Vehicles (UAVs) in underground mines and recent advances in obstacle detection systems have allowed for greater experimentation with photogrammetry conducted from a UAV platform in mines. For this study, a UAV-based underground photogrammetry system was developed to manually capture imagery in an inaccessible stope at Barrick Gold Corporation’s Golden Sunlight Mine (GSM) in Whitehall, Montana, to see whether or not the approach is a viable remote sensing technique for gathering georeferenced geotechnical data. Development of the system involved selecting an appropriate UAV platform, identifying a lighting system capable of providing adequate illumination, acquiring a sensor system that consistently avoids obstacles, and choosing the appropriate UAV camera (and its respective settings) for underground UAV-based imaging. In order to georeference the data collected in the inaccessible stope, paintballs were shot into the stope to create ground control points that were then surveyed in laser range detection. These paintball marks had to be in visual line-of-sight and visible in the imagery captured via UAV camera in order to georeferenced them. Using the imagery collected in the stope at GSM, models were constructed and structural features were mapped on those models. Bentley ContextCapture software was able to successfully construct a stope model from the video frame imagery collected via UAV in the stope, while ADAM Technology was not. Split-Engineering’s Split-FX and ADAM Technology were used separately to map the discontinuity planes present within the model. A comparison of underground discontinuity mapping was performed using the UAV-based photogrammetry captured in the stope and hand mapping data collected around the entrance to the stope. It was found that northeasterly striking discontinuity planes were identified using the digital mapping, but not in hand mapping. Using UAV-based photogrammetry for geotechnical data collection creates a quick and thorough mapping process with time-stamped imagery that can potentially create a safer mine. The lessons learned during this study may help guide future efforts using UAVs to capture geologic data and to help monitor stability in areas that are inaccessible

Hardware design for in-mine positioning system

This thesis describes the hardware design of a positioning system which locates a vehicle relative to a digital map of an underground mine. The mines of interest are potash mines of Saskatchewan, and they are at a depth of approximately 1000 meters and they cover an area larger than 10 kilometers by 10 kilometers. An important application of an in-mine positioning system is tracking a ground penetrating radar system. Ground penetrating radar is used to determine the current condition of the mine ceiling and to evaluate its risk of delamination. A ground penetrating radar system is driven along a mine tunnel and measurements are logged. It is necessary to record position information along with the radar signal and this can be done with the aid of a positioning system. The design and evaluation of the hardware system that supports a positioning system, which can locate a vehicle inside a mine tunnel with reasonable accuracy and cost is described in this thesis. The hardware system includes a dead reckoning system (DRS), which is built using MEMS (Micro Electro Mechanical System) accelerometer and gyroscope sensors and ultrasonic distance sensors, along with a data acquisition system

Anti-collision systems in tunneling to improve effectiveness and safety in a system-quality approach: A review of the state of the art

Tunnelling and underground construction operations are often characterized by critical safety issues mainly due to poor visibility and blind spots around large vehicles and equipment. This can lead to collisions between vehicles or between vehicles and pedestrians or structural elements, causing accidents and fatalities. To improve the OS&H conditions, it is important to investigate the possible introduction of innovative techniques and technologies to reduce the occurrences and consequences of shared spaces (spaces used by both vehicles and pedestrians). For this reason, research was conducted to investigate the possible use of different technologies of anti-collision systems in tunnelling operations. First, to achieve this goal, an extensive review of the literature was carried out in accordance with the PRISMA statement to select the current techniques and technologies used by general anti-collision systems in civil and mining construction sites. Then, the operating principles, the relative advantages and disadvantages, combinations, and costs were examined for each of these. Eight types of systems and many examples of applications of anti-collision systems in underground environments were identified as a result of the analysis of the literature. Generally, it was noted that the anti-collision techniques available have found limited application in the excavation sites of underground civil works up to the present day, though the improvement in terms of safety and efficiency would be considerable