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There is a close relationship between stem and leaf biological characteristics of mature broccoli plants and defoliation technology. Morphological parameters such as the spread degree and diameter of cauliflower stem and leaf and the connection performance of cauliflower stem and leaf were studied. These experiments are helpful to the research of defoliation devices and methods for large-scale manual transportation lines. In this paper, according to the damage forms that may be suffered in the separation process of mature broccoli stems and leaves, “sunny” broccoli varieties were selected. Firstly, the mechanical properties of mature broccoli stems were obtained through different loading methods such as stretching, compression, shearing and bending. Secondly, the stress relaxation characteristics of broccoli were analyzed by static compression of broccoli flower balls. Finally, the separation method of broccoli stems and leaves was simulated by ANSYS. The simulation results showed that shear fracture was more suitable for stem and leaf separation of broccoli than tensile fracture. Then, aiming at the separation of stems and leaves of broccoli, an artificial broccoli assembly line was proposed to ensure the efficiency of leaf removal through man–machine cooperation. The dynamic characteristics of the belt of broccoli leaf removal line were studied to ensure the efficient and stable operation of the conveyor system of broccoli artificial leaf removal line.

Roller conveyor line (RCL) plays an important role in smart manufacturing workshop and modern logistics industry. RCL transfers the specified type of workpiece box to specified exports according to the personalized demands. It greatly improves the sorting speed and delivery speed of workpiece. However, the construction of RCL is very time-consuming and difficult because of the unintuitive design and complex control. In order to reduce the difficulty of constructing RCL and eliminate the gap between design and control, a research about cyber-physical system (CPS) for design and control driven by digital twin (DT) is conducted. In this research, three key enabling technologies of constructing five-dimensional DT for RCL are illustrated in detail as follows: (1) multi-scale modeling method of RCL; (2) extensible distributed communication framework; (3) fast mapping method of distributed controllers. Finally, this paper provides a case study of using the CPS driven by DT to design and control RCL. Experimental results show that the CPS in this paper can achieve the rapid design and distributed control of RCL.

Due to increasing demands for ensuring the safety and reliability of a system, fault detection (FD) has received considerable attention in modern industries to monitor their machines. Bulk materials are transported worldwide using belt conveyors as an essential transport system. The majority of conveyor components are monitored continuously to ensure their reliability, but idlers remain a challenge to monitor due to the large number of idlers (rollers) distributed throughout the working environment. These idlers are prone to external noises or disturbances that cause a failure in the underlying system operations. The research community has begun using machine learning (ML) to detect idler’s defects to assist industries in responding to failures on time. Vibration and acoustic measurements are commonly employed to monitor the condition of idlers. However, there has been no comprehensive review of FD for belt conveyor idlers. This paper presents a recent review of acoustic and vibration signal-based fault detection for belt conveyor idlers using ML models. It also discusses major steps in the approaches, such as data collection, signal processing, feature extraction and selection, and ML model construction. Additionally, the paper provides an overview of the main components of belt conveyor systems, sources of defects in idlers, and a brief introduction to ML models. Finally, it highlights critical open challenges and provides future research directions.

Purpose. Justification of conveyor line parameters of a coal mine using initial data on the actual distribution of random freight traffic and taking into account the influence of the speed of transportation of minerals. Methodology. Conducting a comprehensive study. Searching for a theoretical model of freight traffic distribution: - description of the distribution of the actual freight traffic by means of various indicative algebraic functions; - analysis of freight traffic distribution models by various criteria. Obtaining an equation of friction of flexible bodies, taking into account the influence of the speed of movement of the flexible body: - solution of the classical problem of sliding of a flexible body on a block by the method proposed by Euler, but taking into account new concepts of friction of bodies and conservation of mechanical energy; - experimental study of the influence of the conveyor belt speed on the traction capacity of the conveyor. Findings. A theoretical model of random freight flow distribution for mine conveyor transport has been constructed in the form of an algebraic exponential function with separately defined parameters of the ascending and descending branches. A new revision of the equation of friction of flexible bodies is based on the method proposed by Euler, but with the use of new ideas about friction of bodies and conservation of mechanical energy, which became known after his conclusions, and also taking into account the centrifugal forces of a flexible body. According to the study, the traction force of a belt conveyor coincides with that predicted in accordance with the new edition of the equation of friction of flexible bodies, and the friction force of flexible bodies predicted according to the Euler equation has a deviation of 25 % or more. The effect of the conveyor belt speed on the reduction of the traction capacity of a belt conveyor is significantly weaker (up to 3 times) compared to what is assumed by the Euler equation of friction of flexible bodies. Originality. For the first time, a theoretical model of random freight flow distribution for mine conveyor transport has been constructed in the form of an exponential algebraic function, growing and falling, the branches of which are described by the normal law of distribution of a random variable with separately defined parameters. A new version of the equation of friction of flexible bodies has been substantiated, overcoming the existing discrepancies between the Euler law of friction of flexible bodies and the general laws of classical mechanics, and also takes into account the influence of centrifugal forces of a flexible body. Practical value. The initial data of random freight flow, substantiated by the application of the proposed theoretical model of its distribution, and a new version of the equation of friction of flexible bodies have a positive effect on the calculation and selection of rational parameters of the conveyor transport line, contribute to energy savings, and also increase the efficiency and reliability of the mine conveyor-transport system.

This article discusses the problem of unloading a sequence of boxes from a single conveyor line with a minimum number of moves. The problem under study is efficiently solvable with dynamic programming if the complete sequence of boxes is known in advance. In practice, however, the problem typically occurs in a real-time setting where the boxes are simultaneously placed on and picked from the conveyor line. Moreover, a large part of the sequence is often not visible. As a result, only a part of the sequence is known when deciding which boxes to move next. We develop an online algorithm that evaluates the quality of each possible move with a scenario-based stochastic method. Two versions of the algorithm are analyzed: in one version, the quality of each scenario is measured with an exact method, while a heuristic technique is applied in the second version. We evaluate the performance of the proposed algorithms using extensive computational experiments and establish a simple policy for determining which version to choose for specific problems. Numerical results show that the proposed approach consistently provides high-quality results, and compares favorably with the best known deterministic online algorithms. Indeed, the new approach typically provides results with relative gaps of 1–5% to the optimum, which is about 20–80% lower than those obtained with the best deterministic approach.

Purpose. Increasing the efficiency of the conveyor transport system of the mine due to the application of rational parameters, which are calculated objectively on the basis of the reliable output data of random freight flow in the conveyor transport line, taking into account the velocity of minerals transportation, including a perfect theoretical model application of the freight flow distribution. Methodology. Complex research: - statistical studies on the actual distribution of random freight flow in the highly productive stages of the PSU Mine “n.a Heroiv Kosmosu” PJSC “DTEK Pavlohradvuhillia”; - description of histograms of the distribution of random freight flow by various indicative algebraic functions, normal and gamma distribution of a random variable and a specially constructed function with separately defined parameters of its branches; - analysis of research results regarding the correctness of the theoretical model of the distribution of random freight flow according to various criteria of genuineness, a center of grouping, amplitude, velocity of rise and fall, and deviation. Findings. A perfect theoretical model was built in the form of an indicative algebraic function, whose branches are described by the normal distribution law of a random variable with separately determined parameters. It describes well the distribution of random freight flow in the conveyor transport line of the mine and ensures the determination of its parameters by the methods of probability theory. Originality. A theoretical model of the distribution of random freight flow in the conveyor transport line of the mine has been obtained for the first time, which describes well various cases of its distribution, including symmetric and asymmetric ones, and provides the determination of the freight flow parameters by the methods of probability theory. Practical value. The actual value of the coefficient of nonuniformity of the freight flow in the conveyor transport line of the mine, which was determined by a perfect theoretical model, exceeds, by almost a quarter, the value inherent in the model accepted in practice, the normal law of the distribution of a random variable. The coefficient of nonuniformity of the freight flow in the highly productive longwalls of only the specified mine reaches a value of 2.012, which already exceeds the normative value limit for conveyor transport lines along horizontal and inclined preparatory workings of mining areas (2.0). Reliable initial data on the variation of the random freight flow in the conveyor transport line of the mine, which is substantiated by a perfect theoretical model of its distribution, have a positive effect on the calculation of its parameters and contribute to increasing the efficiency and reliability of the functioning of the conveyor transport system.

Digital twin technology is considered as a key technology to realize cyber-physical systems (CPS). However, due to the complexity of building a digital equivalent in virtual space to its physical counterpart, very little progress has been achieved in digital twin application, especially in the complex product assembly shop-floor. In this paper, we propose a framework of digital twin-based smart production management and control approach for complex product assembly shop-floors. Four core techniques embodied in the framework are illustrated in detail as follows: (1) real-time acquisition, organization, and management of the physical assembly shop-floor data, (2) construction of the assembly shop-floor digital twin, (3) digital twin and big data-driven prediction of the assembly shop-floor, and (4) digital twin-based assembly shop-floor production management and control service. To elaborate how to apply the proposed approach to reality, we present detailed implementation process of the proposed digital twin-based smart production management and control approach in a satellite assembly shop-floor scenario. Meanwhile, the future work to completely fulfill digital twin-based smart production management and control concept for complex product assembly shop-floors are discussed.

The paper presents a methodology for determining the volume of a batch of conveyed material located before a transverse partition of a certain height and the distance over which the batch of material extends on the working surface of the conveyor belt along its longitudinal axis. Knowing the geometric dimensions of the transported batch of material makes it possible to appropriately set the spacing of the belt cleats and thereby to optimally determine the conveying performance of the inclined belt conveyor. When the angle of inclination of a conveyor with a straight idler frame is equal to the angle of surcharge of the conveyed material, then no layer of material is carried on the surface of the belt. If the conveyor belt is guided along a trough idler frame, only the lower cross-section of the filling of material is used. An increase in the cross-section of the belt load of a conveyor inclined at an angle, which exceeds the angle of repose of the conveyed material, can be achieved by installing regularly spaced belt cleats around the circumference of the working surface of the endless loop of the conveyor belt. The volume of the batch of material retained by the belt cleat depends on the height and width of the cleat and whether or not the conveyor belt is provided with corrugated side edges. The paper presents theoretically determined relationships that can be used to determine the size of the transverse and longitudinal area and the volume of the batch of material spread on the surface of the conveyor belt in front of the cleat. The experiments performed provide the distances of the material distribution on the surface of the conveyor belt depending on the height of the cleat and the angle of inclination of the conveyor belt.

This study analyses how the orientation of the measurement head in a magnetic diagnostic system affects the parameters of magnetic signals recorded during steel-cord conveyor belt inspection. The experiments were conducted on a laboratory test stand using a reference belt with artificial defects at two belt speeds and several sensitivity thresholds. Three types of head rotation were analyzed: longitudinal (OX), transverse (OY), and planar (OZ). For each configuration, a set of geometric signal parameters was calculated, including length, width, orientation, eccentricity, and solidity. The results showed that rotation about the OX axis caused the greatest geometric distortions (increased orientation_deg and eccentricity). Rotation about the OY axis produced amplitude asymmetry and changes in solidity (circularity), while rotation about the OZ axis resulted in twisting and displacement of the signal centroid. The total area (area_mm2) remained stable, confirming the geometric nature of the observed changes. Even small head deviations (5-10°) may introduce significant interpretation errors. Therefore, the application of geometric calibration and orientation compensation algorithms is recommended to improve the online diagnostic accuracy of the measurement system.

Aiming at solving the problem of high energy consumption in the rated belt speed operation of a belt conveyor system when the material flow rate is reduced, the power consumption of the frequency converter, motor, and belt conveyor is analyzed, a power consumption model of the belt conveyor system is established, the relationship between the power consumption of the belt conveyor system and belt speed is obtained, and a energy-saving control strategy of the belt conveyor with variable belt speed based on the material flow rate is put forward. The energy consumption of the belt conveyor is analyzed for a practical case. Results show that the power consumption model is accurate and the control strategy effectively reduces energy consumption. The model has high application value in coal, ports, power, mine, metallurgy, chemical, and other industries.