Ore Trucks Research Articles

Trajectory tracking control of the pushing ore truck manipulator based on adaptive sliding mode control with interference observer

An improved sliding mode controller was designed to solve the problem of low tracking accuracy caused by various disturbances and errors existing in the hydraulic-driven manipulator for pushing ore truck. The state space equation of the hydraulic system of the pushing ore truck manipulator was modeled and derived, and a sliding mode function was designed. For interference signals, use interference observers for observation. For the unobserved parts, adaptive laws are used for compensation to reduce system chattering, and system’s stability is verified using Lyapunov functions. The simulation results show that, compared with the traditional Sliding mode control and adaptive sliding mode control, the adaptive sliding mode control strategy based on interference observer proposed in this paper can effectively weaken the system chattering, reduce the uncertainty caused by external interference and modeling error, and improve the trajectory tracking accuracy of the pushing ore truck manipulator.

Autonomous robotic rock breaking using a real‐time 3D visual perception system

AbstractCrushing of blasted ore is an essential phase in extraction of valuable minerals in mining industry. It is typically performed in multiple stages with each stage producing finer fragmentation. Performance and throughput of the first stage of crushing is highly dependent on the size distribution of the blasted ore. In the crushing plant, a metal grate prevents oversized boulders from getting into the crusher jaws, and a human‐controlled hydraulic manipulator equipped with a rock hammer is required to break oversized boulders and ensure continuous material flow. This secondary breaking task is event‐based in the sense that ore trucks deliver boulders at irregular intervals, thus requiring constant human supervision to ensure continuous material flow and prevent blockages. To automatize such breaking tasks, an intelligent robotic control system along with a visual perception system (VPS) is essential. In this manuscript, we propose an autonomous breaker system that includes a VPS capable of detecting multiple irregularly shaped rocks, a robotic control system featuring a decision‐making mechanism for determining the breaking order when dealing with multiple rocks, and a comprehensive manipulator control system. We present a proof of concept for an autonomous robotic boulder breaking system, which consists of a stereo‐camera‐based VPS and an industrial rock‐breaking manipulator robotized with our retrofitted system design. The experiments in this study were conducted in a real‐world setup, and the results were evaluated based on the success rates of breaking. The experiments yielded an average success rate of 34% and a break pace of 3.3 attempts per minute.

Real-time fleet management decision support system with security constraints

Intelligent transportation, and in particular, fleet management, has been a forefront concern for a plethora of industries. This statement is especially true for the production of commodities, where transportation represents a central element for operational continuity. Additionally, in many industries, and in particular those with hazardous environments, fleet control must satisfy a wide range of security restrictions to ensure that risks are kept at bay and accidents are minimum. Furthermore, in these environments, any decision support tool must cope with noisy and incomplete data and give recommendations every few minutes. In this work, a fast and efficient decision support tool is presented to help fleet managers oversee and control ore trucks, in a mining setting. The main objective of this system is to help managers avoid interactions between ore trucks and personnel buses, one of the most critical security constraints in our case study, keeping a minimum security distance between the two at all times. Furthermore, additional algorithms are developed and implemented, so that this approach can work with real-life noisy GPS data. Through the use of historical data, the performance of this decision support system is studied, validating that it works under the real-life conditions presented by the company. The experimental results show that the proposed approach improved truck and road utilization significantly while allowing the fleet manager to control the security distance required by their procedures.

Новые технические решения по проветриванию глубоких карьеров

The paper discusses the issues of ventilating in deep quarries caused by the intensification of blasting operations at great depths, the increased distance of ore truck transportation to the daylight area, constant change in the geometrical parameters of the quarry, its microrelief and direction of mining, and increased isolation of the mined space from the environment. We provide a brief analysis of the current tools for forced airflow in deep quarries, which showed that the use of forced ventilation is often challenging since it leads to high energy consumption, high level of noise exceeding the permissible parameters, and high speeds of forced air flows may blow the dust off the quarry surfaces.The article presents methods and tools developed at the Siberian Federal University for intensifying the natural airflow in deep quarries by changing the air density at the entrance and exit points of the pit, as well as heating the shady areas using mirrors and solar energy, which do not interfere with mining and blasting operations.

MINIMAL CURVATURE-CONSTRAINED PATHS IN THE PLANE WITH A CONSTRAINT ON ARCS WITH OPPOSITE ORIENTATIONS

The declines that provide vehicle access in an underground mine are typically designed as paths formed by concatenating line segments and circular arcs. In order to reduce wear on the ore trucks and the road surfaces and to enhance driver safety, such paths may be subject to a further constraint: each pair of consecutive arcs with opposite orientations must be separated by a straight line segment of at least a certain specified length. In order to reduce the construction and operational costs of the mine, it is desirable to minimize the lengths of such paths between any given pair of directed points. Some necessary and sufficient conditions are obtained for paths of this form to be locally or globally minimal with respect to length. In particular, it is shown that there is always a globally minimal path that contains at most four circular arcs.

PSYCHOSOCIAL AND HEALTH IMPACTS OF URANIUM MINING AND MILLING ON NAVAJO LANDS

The uranium industry in the American Southwest has had profoundly negative impacts on American Indian communities. Navajo workers experienced significant health problems, including lung cancer and nonmalignant respiratory diseases, and psychosocial problems, such as depression and anxiety. There were four uranium processing mills and approximately 1,200 uranium mines on the Navajo Nation's over 27,000 square miles. In this paper, a chronology is presented of how uranium mining and milling impacted the lives of Navajo workers and their families. Local community leaders organized meetings across the reservation to inform workers and their families about the relationship between worker exposures and possible health problems. A reservation-wide effort resulted in activists working with political leaders and attorneys to write radiation compensation legislation, which was passed in 1990 as the Radiation Exposure Compensation Act (RECA) and included underground uranium miners, atomic downwinders, and nuclear test-site workers. Later efforts resulted in the inclusion of surface miners, ore truck haulers, and millworkers in the RECA Amendments of 2000. On the Navajo Nation, the Office of Navajo Uranium Workers was created to assist workers and their families to apply for RECA funds. Present issues concerning the Navajo and other uranium-impacted groups include those who worked in mining and milling after 1971 and are excluded from RECA. Perceptions about uranium health impacts have contributed recently to the Navajo people rejecting a resumption of uranium mining and milling on Navajo lands.

Spatial patterns of cadmium and lead deposition on and adjacent to National Park Service lands in the vicinity of Red Dog Mine, Alaska

Heavy metal escapement associated with ore trucks is known to occur along the DeLong Mountain Regional Transportation System (DMTS) haul road corridor in Cape Krusenstern National Monument, northwest Alaska. Heavy metal concentrations in Hylocomium splendens moss ( n = 226) were used in geostatistical models to predict the extent and pattern of atmospheric deposition of Cd and Pb on Monument lands. A stratified grid-based sample design was used with more intensive sampling near mine-related activity areas. Spatial predictions were used to produce maps of concentration patterns, and to estimate the total area in 10 moss concentration categories. Heavy metal levels in moss were highest immediately adjacent to the DMTS haul road (Cd > 24 mg/kg dw; Pb > 900 mg/kg dw). Spatial regression analyses indicated that heavy metal deposition decreased with the log of distance from the DMTS haul road and the DMTS port site. Analysis of subsurface soil suggested that observed patterns of heavy metal deposition reflected in moss were not attributable to subsurface lithology at the sample points. Further, moss Pb concentrations throughout the northern half of the study area were high relative to concentrations previously reported from other Arctic Alaska sites. Collectively, these findings indicate the presence of mine-related heavy metal deposition throughout the northern portion of Cape Krusenstern National Monument. Geospatial analyses suggest that the Pb depositional area extends 25 km north of the haul road to the Kisimilot/Iyikrok hills, and possibly beyond. More study is needed to determine whether higher moss heavy metal concentrations in the northernmost portion of the study area reflect deposition from mining-related activities, weathering from mineralized Pb/Zn outcrops in the broader region, or a combination of the two. South of the DMTS haul road, airborne deposition appears to be constrained by the Tahinichok Mountains. Heavy metal levels continue to diminish south of the mountains, reaching a minimum in the southernmost portion of the study area near the Igichuk Hills (45 km from the haul road). The influence of the mine site was not studied.

Earth observation technology applied to mining-related environmental issues

The environmental awareness of the global mining industry has increased in recent years, from many standpoints.The use a remote-sensing (or 'earth observation') approach in the investigation of historical mining sites to address such issues as acid mine drainage and subsidence has relied so far on aerial photography. Until recently, satellite imagery has lacked the spatial resolution to compete at the scale of an individual mine or mining district. However, a new generation of satellite and airborne technology offers new opportunities on the basis of data collected both in the optical part of the electromagnetic spectrum (visible, near-infrared and shortwave-infrared) and in the microwave wavelength region. Satellite imagery now offers spatial detail at 1-m ground resolution and, thus, mapping scales down to 1 : 5000. Individual ore trucks are resolvable. Additionally, airborne hyperspectral instruments have a sufficiently high spectral resolution to offer remote operational mapping of secondary surface mineralogy, as surrogates to the mapping of acid drainage-related distributions of polluting heavy metals and indicators of stress in the local vegetation. Radar interferometry from satellites has been shown to detect subsidence in old coal-mining areas in terms of centimetres per month—a quantitative objective approach that complements traditional ground surveying. This development is parallelled by that of aircraft-based precision topographic mapping with laser scanning systems (LIDAR). Such technology can also be applied in estimation of the volume of material removed from open-pits or in detection of morphological change in the surfaces of tailings impoundments. Pre-dawn thermal scanning from aircraft can detect and monitor subsurface fires, identify concealed mine-shafts and map the extent of near-surface workings.The increasing trend to cheaper instrumentation and, therefore, lower costs per square kilometre should encourage a thorough evaluation and validation of these latest-generation tools.

In Situ Strength Measurements of Weak Rocks

There is a lack of strength data on weak rocks where cores for conventional testing can only be obtained with difficulty. In recent investigations, strengths are obtained over a 300-ft (91-m) vertical section for calcareous fanglomerates, typical of the Southwestern United States, by plate testing and correlation with seismic velocity measurements. A 240-ton (213-metric ton) ore truck is used to provide the large reaction load necessary to induce failure. Values for the compressive strength are computed from Boussinesq stresses, Mohr circle analysis, and by correlation with P-wave velocity, and range from 451 psi (3.1 MPa) at a depth of 100 ft (61 m) to 863 psi (5.6 MPa) at a depth of 300 ft (122 m). Interpretation of the results of the plate tests provides an interesting example of the different engineering approaches sometimes needed in rock and soil mechanics. Both the plate tests and seismic correlations give similar results and, when used with care, represent simple and reliable methods for strength estimation.

Silver in soils, stream sediments, waters and vegetation near a silver mine and treatment plant at Maratoto, New Zealand

An investigation was made of the silver content of soils, stream sediments, waters and vegetation near a silver mine and treatment plant at Maratoto, New Zealand. Silver in soils showed elevated levels near the treatment plant (due to aerial fall-out), and also in natural vegetation growing over the ore deposits. Pasture soils showed silver contamination derived partly from deposition from ore trucks and partly from flooding by mineralized stream sediments. Silver in pasture species reflected the same pattern. Silver levels in leaves and trunks of Beilschmiedia tawa (A. Cunn.) Benth. et Hook f. ex Kirk showed distinctly different mechanisms of uptake from aerial fall-out and natural uptake by root systems. The silver content of stream waters and stream sediments, though anomalous near the deposits and treatment plant, showed a progressive decrease with increasing distance from the source.

Roadside lead contamination in the Missouri lead belt.

The lead content of soils and vegetation along highways used for truck transport of lead concentrate (essentially lead sulfide) from mines and mills to smelters, was compared with that of control routes with comparable amounts of traffic but no ore transport. Greatly elevated levels of lead were present in soils and vegetation along rights-of-way of ore truck routes. Contamination was limited for the most part to 100 yards or less. This dispersal of lead into the environment could be prevented largely by use of tight covers on the ore vats of the trucks. This is a case of needless contamination of our environment with a toxic substance that can have serious health implications for man and other animal life.

Toxic Heavy Metals in Vegetables and Forage Grasses in Missouri’s Lead Belt

Abstract Missouri supplies approximately 75% of the U.S. production of lead. Lead poisoning of horses in the vicinity of one smelter alarmed local residents about the possible hazards of consuming their fruits and vegetables. County Extension Directors selected cooperators in 7 counties in the lead mining and smelting area and 3 “control” counties in N.C. Missouri to grow lettuce, radishes, and greenbeans for toxic metal analysis. Seed and cultural instructions were furnished all cooperators. All samples were washed in distilled water. Atomic absorption analyses detected the following maximum levels of Pb in μg/g dry weight: lettuce leaf 1324, radish root 518, and greenbean pods 136. Cd levels in μg/g dry weight were as follows: lettuce leaf 34.5, radish root 13.7, and greenbean pods 8.5. Vegetables from control counties contained markedly lower levels of Pb and Cd. Only one smelter is located in the new mining area and considerable Pb ore (essentially powdered PbS) is transported by rail or truck to smelters in older mining areas of S.E. Missouri. Forage grasses (Festuca arundinacea and Tridens flavus) were collected along ore truck and control routes. Maximum levels of Pb (4350 μg/g dry weight, unwashed) and Cd (4.32 μg/g) were detected in samples along highway rights-of-way of ore truck routes. Considerably lower levels were detected along control routes.

Off-highway vehicles

Industrial, agricultural, and military vehicles are classified as "off-highway vehicles"; the class includes tractors, ore trucks, scrapers, and military tanks. These vehicles have prime movers in the 100-to-1000- and-higher horsepower range, generally have top speeds up to 35 mi/h, and operate from low speed at the traction limit to maximum speed over a wide constant-horsepower range. To date, diesel enghtes with gear-shift and torque-converter transmissions have been used. Now, however, the gas turbine has become attractive because of its low weight and bulk per horsepower, particularly for those vehicles whose performance can be raised with higher power. An electric drive system is well suited to a gas turbine prime mover as a means for utilizing the high turbine speed, for handling the large horsepower, and for distributing power to many wheels. On some special heavy vehicles, dc drive systems, patterned after diesel-electric locomotives, are used. Several ac systems using solid-state converters and induction wheel motors have been built experimentally for military vehicles. When all factors are considered, it appears that the combination of the gas turbine and an ac electric drive will become the heavy off-highway vehicle drive system of the future.