Directions of Career Transport Development

Since the beginning of the civilization emergence, people began to use the minerals extraction on the surface of the Earth and the rock mass transportation. One of the main tasks of the mining industry is the transportation of an increasing rock mass amount from the quarry, which has caused the need to increase the power and carrying capacity of mining dump trucks. Today, we can assume that the revolutionary period of increasing the carrying capacity in the creation of heavy-duty dump trucks is over. Further improvement of the designs of frame dump trucks is impractical. To create super-powerful dump trucks capable of efficiently transporting rock mass from deep horizons, fundamentally different designs of machines and power plants are needed. The most important requirement for promising machines is to minimize the negative impact on the environment. In its development, mining vehicles have come a long way: a hand wheelbarrow - a horse cart - a truck - a diesel mining dump truck - a diesel-electric mining dump truck - an electric mining dump truck - an unmanned electric mining dump truck. According to the law of the transition from quantity to quality, it can be assumed that the period of increasing the carrying capacity of mining dump trucks has ended (quantitative changes), and a new period of qualitative changes begins (the development of new types of mining transport, an increase in the specific capacity of a power plant, the use of other energy carriers, etc.). An important area is the use of artificial intelligence: robotic dump trucks, self-diagnostic systems, etc. The main requirement for promising machines is to reduce the cost of transporting rock mass and a minimum negative impact on the environment.

Fluxgate Sensors for Onboard Weighing Systems of Heavy-Duty Dump Trucks

The article reviews the results of the authors’ research on the possibility of using the magnetic field strength generated by DC traction motors as a useful signal carrying information about weight of cargo transported by a mining dump truck.The objective of the research was to find a way to determine weight of cargo carried by a mining dump truck. In contrast to the existing onboard weighing systems, it becomes possible to create a compact autonomous device that does not require integration of sensors into the body structure and electrical circuits of the truck.Problems of increasing the efficiency of measuring devices based on fluxgate converters are considered with the view of using them as onboard systems for estimating cargo weight. The sensitivity of the fluxgate sensor can be increased by increasing both the amplitude and the effective value of the voltage applied to its excitation winding. The proposed original circuit for feeding the fluxgate sensor’s excitation winding from a modulated signal generator made on logical elements allows increasing the voltage supplied to the fluxgate sensor’s excitation winding without increasing the supply voltage, and by increasing voltage surges at the fronts of rectangular modulated high-frequency pulses, as well as due to resonant phenomena. The use of such a generator excludes the influence of the fluxgate sensor’s excitation winding on the generator frequency, since the frequency of modulating signals becomes the operating frequency of the fluxgate sensor, and it remains unchanged. The increased sensitivity makes it possible to install the sensor in any convenient place in the dump truck cab, and not in the immediate vicinity of traction motors.Evaluation of cargo weight is carried out during movement of the dump truck along the control section of the road. The readings are taken from an ammeter (milliammeter), the scale of which is pre-calibrated in mass units. Measurements of mass should be carried out under the same modes of dump truck movement and with the same location of the fluxgate sensor as when calibrating the scale of the measuring device. The control section of the route on which the measurements are carried out must be the same or similar to the one on which the measuring device was calibrated.The proposed device is distinguished by ease of use, is characterised by low energy consumption, is compact, does not contain expensive elements and does not require careful maintenance.

Research of control algorithm of traction drive of a mining dump truck using simulation models of motion

The paper describes control algorithms for a combined power plant made according to a sequential scheme for a 6x6 mining dump truck. The general approaches used in the development of control systems for similar power plants and transmissions are described. The methods of testing and simulation mathematical models used to analyze the operation of control systems for combined power plants are presented. As an example of control systems, the architecture of the developed system used for a mining dump truck is given. The developed control system and simulation model make it possible to analyze the behavior of the traction motor, energy storage device, transmission elements, and operational properties.

ESTIMATION OF THE MASS OF CARGO DUMP TRUCK

The article discusses an on-board weighing system for the load of a mining dump truck, which simplifies measurements and, unlike existing systems, does not require the integration of sensors into the structure and electrical circuits of the truck and represents a compact, autonomous device that can be located at any convenient place in the cab. In order to create such a device, it is proposed to use the magnitude of the magnetic field strength generated by DC traction motors as a signal carrying information about the mass of the transported cargo. To measure the magnetic field strength, a flux gate is used, which converts the magnitude of the magnetic field strength into the magnitude of the current. An original circuit for powering the fluxgate excitation winding using a modulated signal generator based on logic elements is proposed. The used power supply scheme allows to exclude the influence of the fluxgate excitation winding on the generator frequency, as well as to increase the fluxgate sensitivity, which makes it possible to install the sensor in any convenient place in the dump truck cabin, and not in the immediate vicinity of the traction motors.

Methodology for assessing safe distances in case of explosions of dump truck tyres in open pit

A fire of a mining dump truck increases the risk of tyre explosion. Mining equipment is extinguished by auxiliary mine rescue crew and mine rescuers who approach it at an unsafe distance. A tyre explosion creates a number of additional hazards that can lead to serious injury or loss of life. Studies indicate that such injuries primarily include barotrauma, eye and general bodily injuries caused by the impact of destroyed wheel elements. A methodology for calculating safe distances is required to ensure the safety of rescue work in open pit mines and quarries. The proposed methodology for estimating safe distances, which was developed based on conditions of a pressure vessel explosion, will reduce the risk of injuries to mine rescuers and members of auxiliary mine rescue crews. The use of existing protective equipment or development of new ones is justified by the presented analysis of injuries such as temporary loss of hearing, eardrum ruptures, brain contusions, loss of consciousness, internal injuries, dislocations, broken limbs and other types of injuries that are caused by tyre explosions.

Multi-objectives Optimization Design of A-type Frame in an Electric Mining Dump Truck Considering Multi-Source Uncertainties Based on the Interval Method

In order to improve fuzzy fatigue reliability and make weight reduction of A-type frame in an electric mining dump truck considering multi-source uncertainties from design, manufacturing and use stage, a multi-objectives optimization method based on the interval theory was proposed in this paper. The thickness of four steel plates in welded A-type frame was regarded as certain design variables, while the elastic modulus and density of material was considered as uncertain variables as well as the load at front traction joint. The relationship between optimization objectives and variables was constructed by the response surface method, and was transformed by the interval method. Then, the optimization problem was solved by the non-dominated sorting genetic algorithm, which was found that the fuzzy fatigue reliability reached up to 98.45 % at the expense of some weight.