The boom-type roadheader plays a crucial role in coal mining. However, conducting the real-time monitoring of the mechanical performance and comprehensive adaptive cutting in the dynamic cutting process are challenging. To address these issues, a digital twin system that integrates the elements of “shape, performance, and control” for roadheaders is presented in this paper. The system comprises three components: physical space, service space, and twin space. The service space forms the core of the entire system. Within this space, twin models and control models are created using numerical simulation, artificial intelligence and multi-source data fusion technology. These models serve the purpose of predicting the roadheader’s mechanical performance and controlling the swing speed of the cutting arm. The physical space is built using technologies such as robot kinematics, electrical systems, hydraulic transmission, and other relevant techniques. This approach facilitates the transmission of multi-sensor data to twin models. The control model then manages the roadheader’s function based on the output signals from the control model. The twin space is constructed utilizing physical rendering engines, databases, and 3D modelling tools. This space visualizes and stores the movement, performance, and control parameters of the roadheader. The results demonstrate that the average absolute error between the measured data from the test’s three position strain gauges and the predicted data from the twin system is 10.38 MPa. Furthermore, the twin system achieves an average update interval of 0.34 s, allowing real-time stress monitoring of the structural components of the roadheader and preventing damage caused by overload. The proposed control model enables adaptive adjustment of the swing speed of the cutting arm in approximately 0.3 s. This improvement significantly enhances the adaptive cutting capabilities of roadheaders when dealing with complex coal and rock formations.
The hydraulic column is a core component in the coal mine support system, however, the real-time monitoring of the hydraulic column during the service process of the hydraulic support faces challenges. To address these issues, a high-precision stress mapping method of hydraulic column is proposed. The hydraulic column loss function was constructed to guide the data-driven model training, and the cylinder stress mechanism model was established by using the elastic–plastic theory of thick-walled cylinder. The weight coefficients of the data-driven model and the mechanism model were determined by the measurement data, and the high-precision stress mapping results were obtained by combining the data-driven model data and mechanism model data. A monitoring platform was built for the unit hydraulic support column, and the unit hydraulic support column was used as the test object to carry out pressure tests of 600 kN, 800 kN, 1000 kN and 1200 kN. The test data of the four groups showed that the error between the stress mapping results and the measured value of the strain gauges was 3.086%, 1.783%, 1.182% and 1.548%, respectively. The mapping period is 0.32 s, which proves that the method can provide real-time and high-precision feedback on the stress state of the hydraulic column, realize real-time monitoring of the stress state of the hydraulic column, solve the problem that stress cannot be measured by attaching strain gauges in the complex underground environment, predict the fault and safety problems of the hydraulic column due to overload, and provide data reserve for the adaptive regulation of the hydraulic support.
Rock burst is one of the most typical dynamic disasters in the process of coal mining. Energy-absorbing components are key to anti-impact equipment. Exploring the mutual feedback relationship between energy-absorbing components and columns for the prevention and control of roadway rock burst is of great significance. In this study, an arc-shaped energy-absorbing component was designed, and its energy-absorbing characteristics were analyzed. The finite element analysis results of the arc-shaped energy-absorbing component were verified via the crushing test machine. The energy-absorption effect of pre-folded, diameter-expanded, eversion, and arc energy-absorbing columns under impact is compared horizontally. The results show that the supporting force is stable during the crushing deformation of the arc-shaped energy-absorbing component, and the average supporting force measured in the test is 1145.35 kN. Compared with the other three energy-absorbing columns, the arc-shaped energy-absorbing column has a lower emulsion pressure peak and the maximum pressure fluctuation amplitude during the impact process; it also has a better deceleration effect on the quality mass. During the impact process, the influence of the arc-shaped energy-absorbing component on the liquid impact in the column is summarized into three stages, namely approximate elasticity, flexible yield energy-absorbing, and approximate rigidity, which can achieve the peak clipping effect on the liquid impact and improve the impact resistance of the column.
Wide-body dump trucks in open-pit mines frequently operate under high loads and severe road conditions, demanding superior dynamic performance from their suspension systems. Existing studies tend to focus only on the influence of individual parameters on the dynamic characteristics of hydro-pneumatic suspensions, lacking systematic analysis of parameter coupling effects and optimal parameter combinations. Taking the two-stage pressure hydro-pneumatic suspension of a wide-body dump truck as the research object, this paper theoretically analyzes its working characteristics and establishes an AMESim model under multiple excitation conditions to reveal how parameter interactions affect the dynamic performance of the suspension. With peak liquid pressure, maximum liquid pressure fluctuation, and maximum vehicle body vertical acceleration as optimization objectives, a multi-objective optimization algorithm is employed to determine the optimal suspension parameters. The results indicate that the interactive responses of damping orifice diameter and check valve diameter with respect to peak pressure and body vertical acceleration exhibit strong nonlinearity. Compared with the original parameter scheme, the optimized design reduces peak liquid pressure, maximum pressure fluctuation, and peak body vertical acceleration by 8.76%, 29.1%, and 11.7%, respectively, significantly improving vehicle ride comfort and mitigating pressure oscillations in the hydro-pneumatic suspension. The research results can provide theoretical support and engineering reference for intelligent operation and maintenance of mine heavy equipment, optimization design of suspension systems and efficient and reliable operation.