With the rapid development of the industrial internet platforms, the virtualisation and ecologicalisation of manufacturing services pose new challenges to the manufacturing service capabilities, especially in terms of the improvement of publishing and transaction functions. Firstly, the demand of manufacturing service capability publishing in the market and the hierarchical structure of the industrial internet platform are analysed in this paper. Then, after defining the functional requirements, the system flow chart and the entity relationship diagram are designed. Lastly, the entire system is designed to illustrate how to publish and trade manufacturing service capabilities on the industrial internet platform.
In order to optimise the configuration of manufacturing services in the virtual and real space and improve the efficiency of the collaboration of manufacturing service resources, we investigate the digital twin systems that provide various services under different service computing modes, analyse their basic network structure from the perspective of complex networks, and reveal internal interaction methods and feedback control process to optimise virtual and real resource allocation and improve physical system stability. On this basis, the characteristics of the manufacturing service network in the digital twin system are further analysed and explained, and the mechanism of manufacturing service collaboration in the virtual-real interaction fusion mode is described.
This work aims at the problem that the temperature rise, gluing or wear of the thread sliding friction pair under fast and heavy load make it difficult to estimate the service life of the equipment. Based on the numerical simulation method and the heat balance theory of the screw friction pair, the bearing characteristics of a self-designed shipborne multi-section free-telescopic screw elevator are studied. The results show that the stress of the thread tooth is mainly concentrated in the root area of the thread tooth, and the load of the thread is mainly concentrated in the first three threads of the meshing thread. When the friction coefficient is more than 0.3, the friction temperature rise will lead to gluing failure. Therefore, a good lubrication environment can effectively reduce the friction coefficient of the thread and reduce the screw contact surface gluing failure caused by the friction torque work heating.
The quality defect is one of the important indicators of hot-rolled coil quality. In order to realise real-time prediction of quality defect and timely control, a data and model-driven predictive diagnosis framework towards hot-rolled coil defect is proposed. Firstly, build a digital twin model from four aspects: geometry, physics, behaviour and rule. On this basis, combined with expert knowledge, deep learning and historical data, a predictive diagnostic model for hot-rolled coil defect was constructed. Then, the data-driven defect diagnosis method is used to realise the prediction of defects, and the model-driven result verification method is used to verify the prediction results. Finally, the accuracy of the result is verified by consistency judgement to improve the defect predictive diagnostic model, thereby improving the accuracy of prediction.
The condition monitoring and fault diagnosis of pump stations are essential to ensure the normal operation of pump stations. This work monitors the vibration, swing, pressure pulsation, noise, speed of the pump unit in the steady and transient operation process and diagnoses the equipment state to judge the safety and health of the unit. The fault feature extraction method suitable for the environment of strong impact and strong noise is studied. The frequency band segmentation, accuracy chart to determine the resonance frequency band and the maximum correlation kurtosis deconvolution method are used to enhance the fault feature. Finally, the data measured are sampled and selected, and the kurtosis of the system software is measured the skewness and other indicators are compared with the indicators of handheld analysis and measurement data. The total accuracy rate of data collected by the system software reaches 98.22%.
The problems to be solved in material distribution can be summarised into two aspects: providing the quantity of materials needed for production and reducing logistics cost. By studying the expression form of the distribution quantity in the distribution process, this paper transformed the distribution demand into the logistics quantity, made an in-depth analysis of the distribution process, represented the change in logistics quantity of different materials with equivalent logistics quantities, and established the mathematical model and system dynamics model of the relationship between logistics quantity and distribution cost. Upon combining the experiment analysis of computer simulation, we finally designed a reasonable materials distribution scheme, which reduces the distribution cost and improves the efficiency of materials transportation.
Same-day delivery refers to the intra-city express of small goods, gifts and documents from sender to receivers. Same-day delivery currently adopts 'taxi' mode to complete the delivery as soon as possible with the sacrifice of lot scale economic benefits. Consequently, it is interesting that whether 'bus' mode featured with lot scale could dominate both in economic and delivery efficiency. To answer this question, simulation is employed to conduct a case study and compare the performance of 'taxi' mode and 'bus' mode. Further, two simulation scenario experiments are presented to find dominate conditions. Finally, we find that with limited distribution resources, 'taxi' mode can exploit advantages in the scenario of concentrated orders in space and low order volume, while 'bus' mode is more suitable for the scenario of wider delivery range and high order volume.
The related researches about energy saving and emission reduction (ESER) of iron and steel products are mostly focused on power or raw material, such as carbon footprint assessment (CFS) and rarely involves water. According to the view of water environment protection, the main index for water footprint assessment (WFA) is proposed in this paper. The concept and methodology of the production water footprint is advanced into life cycle WFA. A life cycle assessment and economic input-output method (LCA and EIO) are introduced to analyse the WFA process, which is mainly depending on grey water footprint, blue water footprint. Finally, a WFA case of iron and steel products is studied and several ESER methods are suggested.
Total cost of quality plays a remarkable role in all companies so they use this information of quality cost to achieve some aims: first of all to improve the quality, to control the quality cost and last but not least to have effects on profit. In the context of management, rough set theory is one of the new ways which is used to analyse the quality costs and determine the crucial indicators of quality. Rough theory is used to collect information about the cost of quality of 11 reputable companies which are active in bourse Iran and belong to the ceramic industry over a period of five years and finally, three high-performance rules have been formed so that managers can use these rules in the industry to analyse the current situation and anticipate the future.
The main characteristics of its components and their interaction are represented in products architecture. A modular architecture can enhance the whole design cycle of a product. The idea of module identification is to minimise interactions between modules and maximise component interconnection within each module. Clustering DSM is a popular analysis technique for modularity. To assess the clustering efficiency, a new index of Cce is tendered to deal with a numerical DSM, as well as a binary DSM. A case study of a motorcycle engine of 17 parts is analysed using the proposed assessment to get a better clustering result, which validates the feasibility of the evaluation approach.
SSVEP signal is mainly collected by a wet electrode. Wet electrode collection steps are tedious, and dry electrode collection is simple and easy to apply, so the study of dry electrode is the focus of SSVEP research. Although the dry electrode is easy to collect, the ITR is low and the signal intensity of the EEG signal of the subjects is highly differentiated. At present, the cross trial classification of SSVEP is the focus and difficulty of research. In order to be able to meet the situation without calibration and can still have higher adaptability, in this paper, deep convolutional neural network is improved for the classification of dry electrode SSVEP. The classification of ten types of SSVEP dry electrode signals can reach the classification accuracy of 91.11%, and the ITR of 1S can reach 54.87, which has a very broad application scenario.
This paper tackles the difficult task of identifying risk and opportunities quantify them and propose mitigation plans that minimise the impact of the risk in manufacturing projects. For this reason, a discrete events simulation model representative of a manufacturing plant and manufacturing strategy has been developed. This simulation model will be able to identify and assess the risks of the project with regard to risk effect in the schedule or in the manufacturing cost and, on the other hand, simulation model will be used in combination with an optimiser based on genetic algorithms (GAs), allowing the design of new manufacturing strategies or new plant layouts. Finally, the experimental results were obtained customising the simulation model for a real project of manufacturing wind turbine foundations, in particular to the piles that hold the lattice structure (jacket) to the bottom of the sea.
The use of thermoplastic elastomers has increased strongly in recent decades in order to improve the manufacturing of numerous components within the machinery construction and automotive industry. The high manufacturing costs for this type of materials require a careful design phase in order to the final product can be according with the required specifications. One of the most important challenges that engineers face when designing with this type of materials is the simulation of mechanical behaviour using numerical methods. This task is not always easy since these materials often have a strongly nonlinear behaviour. In this work, a thermoplastic elastomer material has been analysed and an automotive component has been studied by means of five numerical simulations with five different constitutive models of material. This study shows that a careful selection of the constitutive model must be made to obtain reliable results since although several constitutive models fit well with the experimental data of the uniaxial and planar extension tests, when used in real components, there are significant differences in the obtained results.
The production possibilities of electric bicycles range from simple assemblies to in-plant production of main components such as the engine or frame. In Mexico, small companies were the first to produce e-bikes; however, this sector faces the lack of theoretical tools for the design and implementation of their manufacturing systems. The purpose of this study was to develop a simulation model of an e-bike manufacturing system that maximises the system productivity. The model was developed using the DES methodology proposed by Jerry Banks and was implemented in Anylogic™ software. The design and analysis of experiments was performed using Minitab® software. The simulation time was defined according to the user, so the working time was 160 hours per month, producing a daily unit. The results indicated that the maximum system productivity was 300 units per year. The best times achieved were: 2.35 units per hour, for the material flow, for welding 1 h, for the turning process 0.58 h and finally for the electrical assembly 0.66 h.
Quebec hydraulic power plants are mainly operated with large Francis turbines due to their ability to comply with a wide range of rates of flow and falls' heights. The variation of hydraulic conditions from one site to another forced engineers to create each time a new design for the runners and consequently lead to different thicknesses, sizes and shapes for the blades. The unit production costs are inevitably high since the punch and die matrices are completely redesigned for the production of a specific batch of blades. In this paper, the authors focus on a reconfigurable setup of punch and die matrices for forming blades from very thick plates offering a flexible alternative to the conventional setup. First, in order to validate the numerical model, a finite element simulation of the pressing process with a continuous conventional punch and die pair is performed. Second, the methodology for setting up a reconfigurable punch and die pair, based on a dense distribution of spherical headed poles, is presented. The model is then inserted in the previous finite element procedure. Numerical results agree well with data collected on blades pressed for the rehabilitation of a hydropower plant in Quebec.
This paper assesses the impact of the arrangement of pillars and building height in residential building structures and its effect on the environmental impacts of the structural solution. Impacts are analysed in the elements of the structure: foundations, pillars (or columns), and slabs. The manufacturing process of materials and the process of implementation of the proposed structure are measured by using both embodied energy and carbon footprint. The results are obtained per executed square meter. The analysis provides the optimal arrangement for the pillars and the height of the building; the increase in separation of the pillars causes greater impacts, and the design of tall buildings also drives to an important increase of resource consumption. The blocks in which the structures were split have different weights. The most representative are the slabs, around 80% compared to 7% of the pillars and 13% of the foundations. The decisions made in the layout of pillars in the design phase have a different impact on the items of the structure, and their analysis and assessment are developed in this work.
This article aims to respond to growing concerns about sustainable urbanisation, which in recent years have generated a need for prospective assessment in the field of transport and land-use planning, by predicting future land-use development. We introduce a land use model (part LU of a land use transport interaction model) which aims to simulate households and economic activities location choice within an urban system. We use the agent-based approach to simulate location choices to account for land use changes and to estimate residential and economic activities location. This is a dynamic bottom-up approach with the households and the firms as their basic components. The MUST-B model considers the agents' location choices according to the utility theory and the equilibrium between real estate supply and demand. The model is used to simulate urban land-use development in the urban area of Bordeaux, France.
An alarm device consisting of data collection module, control module and radio frequency module for locating people submerged beneath water is investigated. By combining the magnetic field distribution information and acceleration sensor, the alarm device is able to simulate submerged person movement path in the data collection module. STC89C51 is selected as the main control chip in the control module for alarm switching, information encoding and control of radio frequency mode. A third-generation wireless transceiver chip nRF2401 is adopted in the radio frequency module, allowing data transmission in the international ISM frequency range. The implementation based on the geomagnetic sensor that is simple in design, boasts full functions and has excellent drowning detection sensitivity. Additional wireless emission coordinate capability will improve efficiency and shipwreck rescue and maritime navigation in the future.
The high efficiency is demanded in aerospace field. In the design of the control system, adopting single processor can hardly meet the demand of efficiency required. However processor array's hardware size and off-chip bus delay cannot be ignored. In order to solve the above mentioned problems, this paper is intended to study multi-task collaborative parallel design based on multi-core SOC (system on chip). Firstly, multi-core architecture based on SOC is achieved, which includes constructing two MicroBlaze cores, two ARM (advanced RISC machines) cores and designing inter-core communication, as well as designing external data collection and hardware acceleration unit based on FPGA (field programmable gate array). Secondly, collaborative parallel design in missile control system is studied. Finally, a verification platform is developed. By comparing with single core processor, it is proved that the approaches proposed have advantages over enhancing the efficiency.
