Non-standard Parts Research Articles

Automating pouring process in precision casting

Standing at the intersection of industry 4.0, most traditional manufacturers, especially those produce non-standard parts, are still facing the challenges from multiple aspects on the implementation of automations, that indicates a significant and necessary step towards their upgrading. The potential performance improvement that could be brought by the automation may be continuingly squeezed as the increasement of complexity when dealing with the various targets. This article is extended by a general concept of implementing automation on the metal pouring process of precision casting, aims to explore an efficient and robust automation solution with the integration of human-robots collaboration and the adoption of computer science techniques. The implementation emphasizes the reduction of unnecessary complexities from each working step, the applied algorithms, such as Object Bounding, Greedy Strategy and Last-In-First-Out, have been correspondingly tailored based on the characteristics of its engaged working steps and illustrated by the flowcharts. Both the adaptability and practicability of the automation are expected to be enhanced with the principles of constructing easy-interactive frames, allowing a certain degree of human intervention, and proactively utilizing the matured algorithms.

A Knowledge-graph based Method for Datum Reference Frame Reasoning

In mechanical engineering, the datum is essential in the tolerance specification, which impacts assembly and functional requirements. The standard mechanical parts, such as shaft and gear, already have a formalized datum reference frame (DRF) design process. However, non-standard parts still mainly rely on manual design. To this end, a knowledge-graph-based DRF reasoning method for non-standard parts is proposed. In this paper, an OWL 2-based knowledge model is constructed according to industrial practice. It combines empirical knowledge, knowledge graphs, and ontology reasoning methods to perform DRF generation automatically and precisely. The finite element method is introduced into this work to evaluate reasoned DRF. The effectiveness and feasibility of the method are demonstrated via a case study.

A small sample nonstandard gear surface defect detection method

To address the issues of low detection precision, slow detection speed, and imbalanced defect samples in the surface defect detection of nonstandard parts, we propose a method based on the defect detection model YOLOv8-2d and the balancing generative adversarial network (BAGAN). First, we use an attention mechanism without parameters to help the detection model focus on the defect area in the middle-level features based on the feature scale and distribution characteristics of surface defects on nonstandard parts. Second, we introduce deformable convolution and propose a path aggregation feature pyramid network (PADSFPN) with depth-separable convolution, effectively integrating multiscale feature information. Then, we use a Mish network with WIoU as the network head and extract the position and category information of the defect separately, learn through different network branches, and merge the information. Finally, we use BAGAN to expand the small sample defect dataset on the surface of nonstandard parts to achieve dataset balance. The proposed improvements are evaluated through comparative experiments in published twenty test groups, and the effectiveness of the proposed method is demonstrated. Compared with the original model, our method achieves a defect detection precision of 99.83%, a 7.7% improvement; an inference speed of 455 FPS, a 374% increase; and a mAP50 of 97.3%, a gain of 5.03%. Our proposed method maintains high precision while reducing the model's computational complexity and parameter volume, improving its efficiency and robustness in surface defect detection on nonstandard parts.

Разработка конструкции индуктора для закалки детали сложной формы

Due to active process of import substitution, domestic industry starts producing the parts previously purchased abroad. These parts are necessary for stable and reliable operation of various technical objects and systems. Thus, the development of a technological installation for hardening a metal profile is topical. The task is complicated by the fact that the profile has very thin irregularly shaped walls, which should be hardened only from the inside, while the outer wall of the profile should be heated minimally to maintain strength. The studies have been carried out on simulation models of electromagnetic and thermal fields, which make it possible to reproduce the process of induction heating of the research object. Since the part has the same shape along the entire length, the simulation of the process of its induction heating is performed in two-dimensional space. The authors have developed a simulation model of the process of induction heating of a part of a non-standard shape, which includes calculations of thermal and electromagnetic fields. The design of the inductor is proposed, supplemented with ferrite inserts, which makes it possible to achieve the temperature regime necessary for the hardening process. The developed simulation model makes it possible to evaluate the distribution of the thermal and electromagnetic fields of the part, thereby predicting getting the temperatures required for its hardening when using various designs of inductors. The results of numerical experiments are consistent with the physical concepts of induction heating and prove the possibility to use induction hardening for thin-walled parts of complex shape instead of laser hardening used for this type of parts. The proposed model can be used in engineering practice to design inductors of non-standard parts.

On the Design and Implementation of a Blockchain-Based Data Management System for ETO Manufacturing

Engineer-to-order (ETO) is a currently popular production model that can meet customers’ individual needs, for which the orders are primarily non-standard parts or small batches. This production model has caused many management challenges, including the difficulty of tracing the production process data of products and the inability to monitor order status in real-time. In this paper, by analyzing the steps of ETO manufacturing and the business process between departments in the manufacturing industry, a blockchain-based process data management system (BPDMS) is proposed. The immutable nature of the blockchain data ensures the data’s validity and consistency in each production step. Furthermore, by embedding the sequential aggregate signature in the system, the sequence verification of discrete process steps can be completed in time. Finally, an electrical equipment assembly production platform is used to discuss the specific implementation on top of the Hyperledger Fabric, a permissioned blockchain. The experiment results show that the proposed system effectively manages the process data of ETO-type production, and the real-time querying of the production status of the orders.

Freehand-Sketched Part Recognition Using VGG-CapsNet

<p indent=0mm>To solve the problem that the existing CAD system is difficult to match the corresponding parts accurately through the freehand sketch in the conceptual design, a recognition model (VGG-CapsNet) for freehand sketch of part is proposed, which combining the pre-trained network (VGG) and capsule network (CapsNet). Five designers are recruited to sketch parts, and build 23 kinds of freehand sketch of parts including standard parts and non-standard parts. The between-group experiment and within-group experiment are designed, and then the recognition models of VGG-CapsNet are constructed respectively. The recognition results of the VGG-CapsNet models are compared with the rVGG-13 models and the rCNN-13 models. The experimental results show that the mean accuracy of VGG-CapsNet model is higher than the other two models, which provides technical support for the retrieval and reuse of part design knowledge.

Design and Application of Spiral Wound Gasket Sealing for Big Opening Flange for High Temperature and Pressure Vessel

Metallic spiral-wound gasket sealing are generally applicable for the service conditions, which are subject to the periodic temperature and pressure changes, shocks or vibrations. The nominal size of the largest spiral wound gasket of flanges is according to the provisions of HG/T 20631; those more than this specification are in the scope of non-standard parts, which require customization and manufacturing. This paper aims for introducing the successful experience of the first application of customized for non-standard spiral-wound gasket sealing of the large opening flange used for pressure vessel which bears high temperature and high pressure. The paper demonstrated the basic principle and critical points for the design and application of customized non-standard spiral-wound gasket sealing for the large opening flange and provided the valuable reference of actual application experience for the design and manufacturing of similar components. This paper presents the experiences summary in the study field and provides valuable reference of actual application experience for the design and manufacturing of similar components.

Design of High Precision Image Measurement System for Small Workpiece

At present, there are many problems in the measurement of small machined parts (size ⩽ 70mm, such as micro circuit board, small non-standard parts, etc.), such as the difficulty and low efficiency of detection, the large data of sizes to be detected, and mainly rely on manual work. A high-precision image measurement system based on machine vision is designed in this paper, and the systematic error and random error of the machine vision measurement system are improved from hardware and software. Experiments show that size measurement of small workpiece with high efficiency and high accuracy can be realized by the system successfully. The measurement accuracy reaches micron level, which fully meets the testing requirements of production line, and has great value of industrialization promotion.

Experimental study on parameters of Fabbster and Picaso 3D personal printers with XZ-Head Y-Bed and XY-Head Z-Bed kinematics

The use of additive technologies greatly simplifies the production of parts of complex shapes. Improving the quality and increasing the speed of printing are urgent tasks for studying the possibilities of applying 3D printing technologies. The experimental study of the kinematic characteristics of 3D printers, considered in the current article, enables to identify problem areas in the designs of existing models of devices for innovative production of non-standard configuration parts, which must be taken into account when designing new.

Quantum refinement with multiple conformations: application to the P-cluster in nitrogenase.

X-ray crystallography is the main source of atomistic information on the structure of proteins. Normal crystal structures are obtained as a compromise between the X-ray scattering data and a set of empirical restraints that ensure chemically reasonable bond lengths and angles. However, such restraints are not always available or accurate for nonstandard parts of the structure, for example substrates, inhibitors and metal sites. The method of quantum refinement, in which these empirical restraints are replaced by quantum-mechanical (QM) calculations, has previously been suggested for small but interesting parts of the protein. Here, this approach is extended to allow for multiple conformations in the QM region by performing separate QM calculations for each conformation. This approach is shown to work properly and leads to improved structures in terms ofelectron-density maps and real-space difference density Z-scores. It is also shown that the quality of the structures can be gauged using QM strain energies. The approach, called ComQumX-2QM, is applied to the P-cluster in two different crystal structures of the enzyme nitrogenase, i.e. an Fe8S7Cys6 cluster, used for electron transfer. One structure is at a very high resolution (1.0 Å) and shows a mixture of two different oxidation states, the fully reduced PN state (Fe82+, 20%) and the doubly oxidized P2+ state (80%). In the original crystal structure the coordinates differed for only two iron ions, but here it is shown that the two states also show differences in other atoms of up to 0.7 Å. The second structure is at a more modest resolution, 2.1 Å, and was originally suggested to show only the one-electron oxidized state, P1+. Here, it is shown that it is rather a 50/50% mixture of the P1+ and P2+ states and that many of the Fe-Fe and Fe-S distances in the original structure were quite inaccurate (by up to 0.8 Å). This shows that the new ComQumX-2QM approach can be used to sort out what is actually seen in crystal structures with dual conformations and to give locally improved coordinates.

Design and Manufacturing of a Non-Standard Chain Parts for a Chain Conveyor for a Harvest Shallot: A Case Study

This paper presents a complete case study for designing and manufacturing chain parts for chain conveyor use for a harvest shallot for a real. The process of harvesting shallot in Vietnam is being done manually. Mechanization, automation of the harvest process has been demanded by farmers. In the harvest shallot equipment, the chain conveyor system is used to handling the desired orbit to the packing position. Shallots are uneven in size, distributed in a certain size range. Chain conveyor systems with the chain was non-standardized were choiced. Therefore, a complete design is required to meet requirement. The design procedures are: (1) calculation of the expected loads that exert on the chain during operation, (2) selection of materials, (3) designing the different parts of the chain taking into account safety, assembly process and economic considerations. The final design was justified and validated. The chain of chain conveyor system is working properly and safety under real conditions.

The Roughness of the Contact Surfaces of Plastic Cylindrical Gears with a Circular Tooth during Additive Shaping

The article discusses the problems of using FDM technologies in the formation of plastic gears with circular teeth. It is shown that additive technologies are becoming increasingly important in the manufacture of non-standard parts. The role of such an important parameter as the roughness of the side surface of the teeth, which has a significant impact on the durability of gearing, is emphasized. The method for calculating the configuration of liquefied material layer on a solid flat surface is proposed. This method is based on a model of the interaction of the internal three-dimensional state of liquid material layer, a two-dimensional material film, and a material line closing it. The state and shape of the liquid layer on a flat surface was analyzed under the assumption of the validity of the Yungi equation, connecting the wetting angle with the values of surface tensions. The dependences, allowing calculating the amount of irregularities of the lateral surface of the circular teeth of plastic cylindrical gears, are given.

Yoga Posture Recognition and Quantitative Evaluation with Wearable Sensors Based on Two-Stage Classifier and Prior Bayesian Network.

Currently, with the satisfaction of people’s material life, sports, like yoga and tai chi, have become essential activities in people’s daily life. For most yoga amateurs, they could only learn yoga by self-study, like mechanically imitating from yoga video. They could not know whether they performed standardly without feedback and guidance. In this paper, we proposed a full-body posture modeling and quantitative evaluation method to recognize and evaluate yoga postures to provide guidance to the learner. Back propagation artificial neural network (BP-ANN) was adopted as the first classifier to divide yoga postures into different categories, and fuzzy C-means (FCM) was utilized as the second classifier to classify the postures in a category. The posture data on each body part was regarded as a multidimensional Gaussian variable to build a Bayesian network. The conditional probability of the Gaussian variable corresponding to each body part relative to the Gaussian variable corresponding to the connected body part was used as criterion to quantitatively evaluate the standard degree of body parts. The angular differences between nonstandard parts and the standard model could be calculated to provide guidance with an easily-accepted language, such as “lift up your left arm”, “straighten your right forearm”. To evaluate our method, a wearable device with 11 inertial measurement units (IMUs) fixed onto the body was designed to measure yoga posture data with quaternion format, and the posture database with a total of 211,643 data frames and 1831 posture instances was collected from 11 subjects. Both the posture recognition test and evaluation test were conducted. In the recognition test, 30% data was randomly picked from the database to train BP-ANN and FCM classifiers, and the recognition accuracy of the remaining 70% data was 95.39%, which is highly competitive with previous posture recognition approaches. In the evaluation test, 30% data were picked randomly from subject three, subject four, and subject six, to train the Bayesian network. The probabilities of nonstandard parts were almost all smaller than 0.3, while the probabilities of standard parts were almost all greater than 0.5, and thus the nonstandard parts of body posture could be effectively separated and picked for guidance. We also tested separately the trainers’ yoga posture performance in the condition of without and with guidance provided by our proposed method. The results showed that with guidance, the joint angle errors significantly decreased.

Structural Analysis and Application of Non-Standard Components Based on Genetic Algorithm

Aiming at the problems of low efficiency, heavy quality, and high cost of traditional components, it is necessary to study a design and analysis method of non-standard components. Taking the non-standard parts-turret loading and -unloading device as the carrier, the key parts of the non-standard parts are extracted for structural design and the multi-objective mathematical model and modal theory model are established. The optimization analysis of the key parts is carried out by genetic algorithm. Finally, the optimization results are compared and simulated by ANSYS Workbench. The results show that: in this case, the genetic algorithm optimized data with other data, the overall quality difference is 4.1%. The first six order modal values in the optimized results are in the range of 68 Hz to 130 Hz, which provides a basis for similar research in the future.

A computational framework for predicting onset and crack propagation in composite structures via eXtended Finite Element Method (XFEM)

Abstract The eXtended Finite Element Method (XFEM) has been reliably used for analyzing crack growth in 3D structural elements over last years. In fact, many researchers have worked in this field, but it is scarce to find scientific contributions about 3D XFEM models applied to the failure of non-standard composite parts, such as tapered structures and thick laminated composites. Thus, a new computational framework is developed, which is based on a new enhanced golden section search algorithm and 3D Puck’s action plane principle in order to define the crack initiation direction. This in-formation is integrated into a XFEM and used to enrich elements, which have failed during analysis. Compared to the traditional algorithm, the new methodology has convergence one order higher than the traditional one; and it is 20 times more efficient computationally. Therefore, if more precision is needed, then higher gains are achieved combined to lower computational cost by using the proposed framework. Moreover, thick laminated composites with layers mainly oriented to 90o were simulated under tension and compression via the computational framework, displaying results as reported in the literature. Also, compact tension tests with 0°, 90° and 45° specimens were evaluated, and numerical results were qualitatively coherent with experimental data.

Design and Manufacturing of a Non-Standard Chain Parts for a Scraper Chain Conveyor: A Case Study

This paper presents a complete case study for designing and manufacturing chain parts for scraper chain conveyor (SCC) for a real client (chicken’s dietary supplements company). The chain of the SCC is dilapidated due to joints and pins deterioration. The Productivity was reduced as a result of operating at low capacity load and repeated maintenance. The condition of chain was too worse and not able to be repaired. Furthermore, the chain was non-standardized. Therefore, a complete design is required to replace the damage parts of the chain. The design procedures are: (1) calculation of the expected loads that exert on the chain during operation, (2) selection of materials, (3) designing the different parts of the chain taking into account safety, assembly process and economic considerations. The final design was justified and validated. The SCC is working properly and safety under various load capacities.

Rationale construction of individual elements of technological complex

In this paper, we propose the substantiation procedure of a technological complex design on the example of a seeding complex. As a result of performed research, design of the seeding complex for grain crops has been improved using non-standard devices and typical parts that provide: reduction in the time of seeding and energy consumption, possibility of using the seeding complex as a cultivator and a disk harrow. Analysis of computational research results allowed us to specify the following parameters: disc angle of 15 degrees, while the specific traction resistance of the seeding complex does not exceed 3.44 kN/m on the stubble background, and 3.19 kN/m on the fallow background. Field studies of the developed complex has shown that at the given seeding depth (with the variation ± 1cm) the accuracy is 83.5 ... 84.2 %. Optimum quantity of plants of grain crops per unit area is provided under the following conditions: bucket volume 7,2 dm3, distance between buckets 0.21 m; speed of the bucket elevator is 0.12 m/s. The proposed design of the seeding complex is recommended to be used for combining several operations: soil preparation, sowing of cereals and soil packing.

Functional Identities on Matrix Algebras

Complete solutions of functional identities \({\sum }_{k\in K}F_{k}\left (\overline {x}_{m}^{k}\right )x_{k} = {\sum }_{l\in L}x_{l}G_{l}\left (\overline {x}_{m}^{l}\right )\) on the matrix algebra Mn (\(\mathbb {F}\)) are given. The nonstandard parts of these solutions turn out to follow from the Cayley-Hamilton identity.

Integrated Production-Distribution Scheduling Problem with Multiple Independent Manufacturers

We consider the nonstandard parts supply chain with a public service platform for machinery integration in China. The platform assigns orders placed by a machinery enterprise to multiple independent manufacturers who produce nonstandard parts and makes production schedule and batch delivery schedule for each manufacturer in a coordinate manner. Each manufacturer has only one plant with parallel machines and is located at a location far away from other manufacturers. Orders are first processed at the plants and then directly shipped from the plants to the enterprise in order to be finished before a given deadline. We study the above integrated production-distribution scheduling problem with multiple manufacturers to maximize a weight sum of the profit of each manufacturer under the constraints that all orders are finished before the deadline and the profit of each manufacturer is not negative. According to the optimal condition analysis, we formulate the problem as a mixed integer programming model and use CPLEX to solve it.

Vliv kvality sadby na parametry konzumních částí vybraných druhů košťálové zeleniny

The aim of this work was to evaluate the influence of seedling preparation technology (seedling flats with cell size of 20 ml, 40 ml and seedlings pulled from patches) and of seedling age at the time of planting (development stages of 3–4 true leaves and 5–6 true leaves) to the qualitative characteristics of seedling of selected cabbage species: white cabbage (Brassica oleraceaL. convar.capitata(L.) Alef. var.albaDC.) –Aros, Avak,Midor; cauliflower (Brassica oleraceaL. convar.botrytis(L.) Alef. var.botrytisL.) –Beta, Delta, Roberand savoy cabbage (Brassica oleraceaL. convar.capitata(L.) Alef. var.sabaudaL.) –Vega, Versus. The diameter and weight of rosaces, resp. heads, was evaluated in the harvested production. After splitting the harvested crop into several groups, the percentage of non-standard portion of the yield was determined. The use of older seedlings (5–6 true leaves) for the white and savoy cabbage planting had a positive influence to both average yield and the harvest earliness. On the other hand, for the cauliflower conclusively better average crop of rosaces and earlier harvests were achieved with younger seedling transplanting (3–4 true leaves). Seedling flats proved to be the most suitable way of seedling preplantation; no differences were found between the characteristics of products cultivated from the seedling flats with 20 ml and 40 ml cell volumes. In average, smaller amount of non-standard harvest plant parts was, gained with the transplanting from larger seedling flats (40 ml cell volume).