Machine System Research Articles

Retracted: Analysis and Design of Cooperative Control Solutions for Electrical Systems of Laser CNC Machines

Retracted: Analysis and Design of Cooperative Control Solutions for Electrical Systems of Laser CNC Machines

The Development of a Stereo Vision System to Study the Nutation Movement of Climbing Plants.

Climbing plants, such as common beans (Phaseolus vulgaris L.), exhibit complex motion patterns that have long captivated researchers. In this study, we introduce a stereo vision machine system for the in-depth analysis of the movement of climbing plants, using image processing and computer vision. Our approach involves two synchronized cameras, one lateral to the plant and the other overhead, enabling the simultaneous 2D position tracking of the plant tip. These data are then leveraged to reconstruct the 3D position of the tip. Furthermore, we investigate the impact of external factors, particularly the presence of support structures, on plant movement dynamics. The proposed method is able to extract the position of the tip in 86-98% of cases, achieving an average reprojection error below 4 px, which means an approximate error in the 3D localization of about 0.5 cm. Our method makes it possible to analyze how the plant nutation responds to its environment, offering insights into the interplay between climbing plants and their surroundings.

A novel semi-supervised prototype network with two-stream wavelet scattering convolutional encoder for TBM main bearing few-shot fault diagnosis

Accurately sensing the main bearing state and diagnosing fault types is crucial to ensure the safe operation of the main drive system of tunnel boring machines. Currently, the research on large-scale bearing fault diagnosis in industrial scenarios is severely limited by the quality and quantity of monitoring data. Conventional external vibration monitoring devices are difficult to adapt to complex and harsh working conditions of excavation equipment, and constantly changing low-speed and heavy-load operating conditions make similar labeled samples very scarce. To tackle this concern, we propose a semi-supervised prototype network with the two-stream wavelet scattering convolutional encoder (TWSCE-SSPN) based on roller state signals. By fusing radial and axial features of rollers using the two-stream structure and employing wavelet scattering transform and attention mechanism in the convolutional feature encoder, the model exhibits excellent feature mapping capabilities. Following the semi-supervised meta-learning paradigm, the proposed model uses the prototype generated by unlabeled sample features to modify the initial prototype generated by labeled sample features to augment the accuracy of classification in few-shot learning. The integrated sensing roller main bearing testbed was set up and fault datasets were established to verify the few-shot classification and anti-noise ability of the algorithm. Experimental results show that TWSCE-SSPN achieved 98.17 % accuracy at 1 shot, which is at least 18.17 % higher than existing methods. Furthermore, even under a signal-to-noise ratio of 0 dB, the few-shot recognition accuracy can remain 91.83 %. This verifies the superiority of the model in diagnosing main bearing faults under few-shot and strong noise conditions.

The use of modern technologies and the machine system Reciproc (VDW) during the revision of the root canals of a tooth with apical periodontitis: a case report

Endodontic retreatment in most cases is indicated with the development of apical periodontitis in teeth with previously treated root canals. This treatment is complicated by the fact that the root canals can be lined with any material: guttapercha pins, paste, cement, anchor and fiberglass pins, resorcinol-formalin paste, fragments of tools can be located in the channels at any level and root canal transportation can occur. The choice of endodontic treatment or tooth extraction is always before dentists. The availability of modern machine files, ultrasound attachments, filling materials and X–ray examinations in the assortment of doctors makes it much easier for dentists and therapists to conduct endodontic treatment and improves its quality. This article presents a clinical case of repeated endodontic treatment of a 2.6 tooth with apical periodontitis and a clinical picture of chronic sinusitis. The article shows the main stages of treatment, the results of X-ray examinations, microbiological examination of the root canal biofilm before and after mechanical treatment with the Reciproc endosystem and long-term results, which will help practicing dentists during root canal revision.

A stiffness matching-based deformation errors control strategy for dual-robot collaborative machining of thin-walled parts

Thin-walled parts are widely used in aerospace industry. To reduce the deformation errors of such thin-walled parts in machining and also to achieve simultaneous machining of both sides, a novel dual-robot machining system is developed in this paper. In this system, the local rigidity of the thin-walled parts can be enhanced via mutual support between two robots on both sides of the parts, thus reducing the deformation error caused by the low rigidity of the parts effectively. Further, a new concept of dual-robot stiffness matching is introduced, and the deformation of thin-walled parts caused by stiffness mismatching between two robots is analyzed and given a close-form solution. On basis of this solution, a dual-robot posture optimization model, which can satisfy the stiffness matching constraint and improve the normal stiffness of two robots, is developed and then is solved efficiently using the proposed easy-execution sequential algorithm based on the directed node graph and Dijkstra searching, thus the deformation errors of thin-walled parts in machining can be ulteriorly controlled effectively. Finally, the computer simulation and experiments are performed and the results demonstrate that the developed dual-robot machining system and the stiffness matching-based deformation control strategy can effectively reduce the deformation of thin-walled parts in machining.

Experimentation and Application of Differential Inductive System for Machine and Human Body Parametric Measurement

In this article, the prototype circuit is constructed and tested to confirm the results obtained through simulation of a differential inductive circuitry. However, some number of errors found are reported in section 7. Analysis is done between the experimentally found results and those obtained from simulation. Test is done on all sections and certain test parameters are set to determine the actual performance of the system. The test parameters are the frequency response of the differential inductive circuit, the oscillatory effect of the movement of the core in and out of the coil, the inductance change, the force/pressure providing motion, wind pressure, the speed of the inward movement of the core and that of the outward movement, the number of turns used, the length of coils, the area of the coil topology, the diameter of the coil and that of the core, the mass of the convulsion bar, the mass of the target, the ambient temperature of the surrounding, density of the magnetic material used, the applied voltage to the timer, the resonant frequency reached, the amount of current voltage and frequency generated, the percentage of the duty cycle found on the resulting signal, the frequency hysteresis found, the range of oscillation bar, the height of coil arrangement, the seesaw concept, the output waveform of the signal, amongst others. The summary of the major contribution of this work includes a novel design of a differential inductive position sensory system along with its model in the form of the sensed parameter equations as a function of the displacement along the length of the coil. The analytical model for linearization compensation and improved transducer response is another component the author of this work claims it as contribution

Research on novel matching topology and characteristics of rotary ultrasonic machining system with inductive contactless power transmitter

Research on novel matching topology and characteristics of rotary ultrasonic machining system with inductive contactless power transmitter

Chatter prediction for parallel mirror milling of thin-walled parts by dual-robot collaborative machining system

Thin-walled parts with double-sided features are widely used in the aerospace industry, but the machining of such parts still faces great challenges due to their weak rigid structure and the positioning errors caused by turning/re-clamping of the workpiece. For this purpose, a novel machining approach for parallel mirror robotic milling of thin-walled parts is proposed. Different from conventional single-sided milling, it can simultaneously machine both sides of the workpiece while avoiding the above problems and improving machining efficiency. However, the introduction of multiple cutting excitations makes the vibration behavior of the workpiece more complicated, thus making it difficult for the dynamic modeling of the dual-robot machining system. This paper aims to uncover the dynamic mechanism of chatter phenomenon in parallel mirror robotic milling process in consideration of the interaction of tool-workpiece-tool system. A dual-robot collaborative machining system is first developed for the milling of thin-walled workpiece, and the method of synchronous motion planning for dual robots is described. The slave robot synchronously follows the master robot and the two milling cutters mounted on tool flange of the robot are kept in mirror position. Over a tooth passing period, the engagement state of the cutters and the workpiece is analyzed considering the effect of rotation phase lag (RPL) between the twin cutters. After that, the vibration state and the corresponding instantaneous displacement of the workpiece can be expressed explicitly, then the dynamic resultant cutting force acting on the workpiece is calculated according to the mechanistic force model. Comprehensively considering the dynamic interaction of the tool-workpiece-tool system, multi-mode and position-dependent modal characteristics of thin-walled part, a time-varying delay differential equation is constructed and solved to explore the dynamical behavior of parallel mirror milling process. The predicted stability lobe diagram is validated by a series of parallel mirror milling tests on thin-walled PMMA plates. Comparisons of numerical and experimental results show that the dynamic model successfully predicts the chatter stability for the parallel mirror milling of thin-walled parts.

Continuous curvature wayline generation using quadratic optimisation for agricultural machine guidance

Navigation systems are widely used in precision agriculture to improve efficiencies and yields. These systems guide agricultural machines to follow waylines calculated based on specific traffic patterns, including straight and curved waylines. While generating straight waylines is relatively straightforward, generating curved waylines presents challenges due to the variation in their shape and curvature during propagation, which can lead to skips and overlaps between adjacent waylines.In this paper, we present a novel method to curved wayline generation by formulating the problem as a non-linear optimisation problem, as opposed to using geometry operations like existing methods. With the designed objective function and constraints, the problem is reduced to a quadratic optimisation problem that can be efficiently solved, and the generated waylines satisfy the curvature constraint, while minimising skips and overlaps. The functionality and applicability of the method were demonstrated with a simulation experiment, the comparison tests with geometric methods, and a field test. Our algorithm achieved coverage over 97%, with overlap and skip rates lower than 0.8% and 2.3%, respectively. The results indicate that our algorithm can generate smooth, continuous curvature waylines with high coverage and low skip/overlap. Furthermore, our algorithm can also generate straight waylines when the input reference line is a straight AB line. This algorithm can be used as a wayline planning component of navigation system for agricultural machines and robots. The code and boundary data utilised in the "Results and Discussion" section are accessible online at https://github.com/prefect-of-gryffindor/curve-wayline-generation.

STEP-NC enabled edge–cloud collaborative manufacturing system for compliant CNC machining

In recent years, edge–cloud collaborative manufacturing systems have been applied to achieve accurate data tracking and intelligent machining analysis in the field of CNC machining. However, due to the lack of other dimensional tags, such as workstep and speed, which are related to process data, the current systems are still at a level of processing time-tag machining data. It is of great significance to address the problem of linking actual machining data with other dimensional tags, which can achieve more accurate and intelligent data interaction between design and manufacturing. This paper proposes an edge–cloud collaborative manufacturing system based on STEP-NC, which enables the exchange of machining data tagged by workstep, improves the accuracy of data traceability, and lays the foundation for more intelligent processing analysis. Especially, a method of dynamic task delivery and data subscription according to the environment is proposed to improve the manufacturing system’s two-way data flow interaction ability. On the basis of that, a manufacturing information segmentation method based on workstep is proposed, which makes it easier to sort information from the coupled data. In addition, the system is compatible with heterogeneous CNC machine tools to achieve large-scale industrial applications. Finally, a prototype system has been installed in a workshop located in COMAC, and corresponding experiments are carried out on the CNC machine tool for COMAC parts manufacturing, which verifies the feasibility of the proposed method.

A Global Approach to Modeling Injection Molding.

A problem of modeling plastic injection forming (molding) is presented, including both the plasticizing system of the injection-forming machine and the mold. When modeling the plastic flow in the mold, the input quantities are essentially unknown, e.g., the plastic melt temperature. Thus, a comprehensive (global) model of the injection-forming process is needed for the flow in the plasticizing system and in the mold. The process output quantities from the plasticizing system will be the input quantities for the mold. When modeling the plastic flow in the injection-forming machine, a comprehensive approach should be applied to consider the solid material conveying, material plasticizing, and the material melt flow. The model of material plasticizing is a basis for building such global models. In this research, the effect of the flow (including plasticizing) in the injection-forming machine on the flow in the mold is studied by simulation (using Moldex3D 2023R3OR 64-bit software) and experimentation. These studies are carried out for the injection forming of selected material using a specialized spiral mold. Simulations performed with the use of Moldex3D software for the plasticizing system significantly improved the accuracy of the simulation of the flow in the mold. However, the best results were obtained using experimental data (plastic melt temperature) as input quantities for mold filling simulations. The novel concepts of injection-forming process modeling based on our previous experimentations are also discussed.

Saturated H∞ control of networked systems under stochastic transmission delays: The random sampling periods case

AbstractIn this paper, the saturated control problems of networked systems with random sampling periods and stochastic transmission delays are investigated. The main issue is to design an saturated controller such that the controlled close‐loop system is exponentially mean‐square stable with a desired performance. A matrix exponential which is different from some existing literature is used to reconstruct the discrete‐time stochastic system to an equivalent yet tractable augmented model without any additional conditional constraint. In virtue of reduced‐order confluent Vandermonde matrix approach and Kronecker product operation, the stability condition in terms of linear matrix inequality is derived and then the desired saturated controller is designed. It should be emphasized that the improved method can also be used for the stability analysis and controller design when the system matrix contains complex roots. Finally, two numerical examples and a three‐axis milling machine system are utilized to manifest the reliability and practicality of the designed strategy.

Comparison of concentrated winding topologies considering transient voltages in the winding system of inverter-driven low-voltage machines

Comparison of concentrated winding topologies considering transient voltages in the winding system of inverter-driven low-voltage machines

Influence of thermal-mechanical stress on the insulation system of a low voltage electrical machine

Influence of thermal-mechanical stress on the insulation system of a low voltage electrical machine

On the question of the possibility of carrying out landscape forestry works

The global trend in the ecological and social functions of forest ecosystems is indicated, and an analysis of the consequences of increasing the area of protective forests in the Russian Federation is given (Forest Code of the Russian Federation, adopted in 2006). The issue of the possibility of carrying out landscape logging work in the area of Syktyvkar (middle taiga of the Komi Republic) in order to improve the aesthetic and recreational appearance of plantings, forestry effect, as well as obtaining pulpwood for JSC “Mondi Syktyvkar” with a minimum hauling distance is considered. An analysis of the hydrographic network and group of forest types in the middle taiga of the Komi Republic is presented. Proposals for carrying out logging operations along the hydrographic network are given. The target wood species for such work has been identified. A system of machines (VSRM + KS) is proposed for organizing and implementing the technological process of wood harvesting in these natural production conditions.

Determination of Chatter-Free Cutting Mode in End Milling

Chatter accompanies the cutting process and is the main obstacle to achieving precision and productivity in milling operations. To reduce the amplitude of vibrations, it was proposed to use a stability lobes diagram (SLD) when assigning cutting modes. The machining system in end milling was represented by a two-mass dynamic model in which each mass has two degrees of freedom. The behavior of such a system was described by a structure with two inputs, in-depth and cutting feed, and a delay in positive feedback on these inputs. A new criterion was applied to design the SLD based on an analysis of the location of the machining system Nyquist diagram on the complex plane. The algorithm for designing a stability chart was developed into an application program, a tool for the technologist-programmer when assigning cutting modes. A method for parameter identification necessary for designing the dynamic system “tool – workpiece” was proposed. The effectiveness of the developed method was proven experimentally when the choice of spindle speed during end milling allows one to reduce the roughness parameter Ra from 3.2 µm to 0.64 µm at the same feed rate of 650 mm/min.

A Comprehensive Characterization of Hollow Conductor Additively Manufactured Coils and Thermal Management System for a 250kW SPM Machine

A Comprehensive Characterization of Hollow Conductor Additively Manufactured Coils and Thermal Management System for a 250kW SPM Machine

An improved AO algorithm optimized PID rectification model for wind speed and wind pressure regulation in video cabinet of tobacco sorting machine

Abstract Sorting and removing impurities is the use of raw materials and light impurities suspended speed differences through the wind to separate the hemp, paper, plastic, and other light materials to remove impurities. Article to tobacco sorting machine video cabinet wind pressure control system principle as a guide, combined with the structure of the sorting and impurity removal machine and the principle of wind speed balance designed to balance the wind speed and wind pressure of the tobacco sorting machine. The control model of wind speed and pressure in the video cabinet system of the tobacco sorting machine is established, and the improved AO algorithm is used for the design of the overall PID controller and optimization of the PID controller’s setting parameters. The IAO algorithm optimizes the parameters of the PID setting controller with a steady state error within 3%, and the introduction of the IAO-PID controller can make the wind speed of the sorting machine system control from 16.4m/s to 11.1m/s within 17ms. When the system detects that the negative pressure of wire feeding changes sharply to about 1.12MPa within 20ms and exceeds the differential pressure start value of 0.9MPa set by the sorter system, the tobacco wire feeding anti-clogging function is activated. The PID controller optimized by the IAO algorithm can achieve precise regulation and control of wind speed and pressure of tobacco sorting machines, improving the sorting efficiency of tobacco production.

Приготовление растворов различной концентрации

When preparing treatment solutions of fertilizers and pesticides for technological processes, one should mix liquids taking into account the precise dosing of components. However, the existing designs of dosing and mixing devices do not provide qualitative dosing. Moreover, a sharp increase of fraction quantity may result in a hydraulic impact. To eliminate these disadvantages, based on analytical research of available designs and patent search results, the authors worked out a mixer for preparing solutions of various concentrations. The device is also capable of changing the ratio of components in the process of operation. The device provides smooth change of preparation concentrations due to the design of dosing valves forming square-shaped ports with a changing configuration. The port plates move relative to each other both horizontally and vertically. The proposed device smoothly changes the concentration of the solution, thereby providing for more accurate dosing. It was experimentally found that a smoother change in the flow rate of treatment liquid according to the solution concentration is observed at a distance from the axes of symmetry of the dosing device disks to the rotation axis of the distribution ports, equal to 0.04 to 0.1 m. The deviation of the actual treatment liquid flow rate from the calculated one does not exceed 5%. The integration of the developed mixer into the systems of fertigation units, sprayers and other specialized machines will ensure better quality of the fine irrigation of plants, seeds, and soil.

Reducing the energy consumption of lifting machines

Modern lifting machines have the ability to recover braking energy and therefore have high energy efficiency. However, the control systems of such machines are of considerable complexity and require the use of storage devices if they work in closed energy supply systems. The paper presents methods for increasing the efficiency of lifting devices at an early stage of design by partial balancing in order to equalize the load during ascent and descent. The technical solutions that can improve the efficiency of modern lifts and shaft elevator systems are presented.