Shanshuang Shi, Huapeng Wu, Yuntao Song and Heikki Handroos
The purpose of this paper is to introduce a development and error modeling of a serial redundant manipulator system applied in nuclear fusion environment. Detailed mechanical…
Abstract
Purpose
The purpose of this paper is to introduce a development and error modeling of a serial redundant manipulator system applied in nuclear fusion environment. Detailed mechanical design of vacuum-compatible arms and actuators are presented, and manipulator flexibility is studied through experiments and model identification algorithm to evaluate the deformation.
Design/methodology/approach
First, the manipulator is designed to be several modular segments to obtain enough and flexible workspace inside the fusion device with narrow and complex geometries. Joint actuators with “rotation-linear-rotation” chains are developed to provide both huge reduction ratios and vacuum sealing. The redundant manipulator system has 11 degree of freedoms in total with a storage cask system to dock with the device vacuum vessel. In addition, to improve the position accuracy, an error prediction model is built based on the experimental study and back-propagation neural network (BPNN) algorithm.
Findings
Currently, the implementation of the manipulator system has been successfully carried out in both atmosphere and vacuum condition. Excellent performance indicates that the mechanical design is suitable. The validation of BPNN model shows an acceptable prediction accuracy (94∼98 per cent) compared with the real measurement.
Originality/value
This is a special robot system which is practically used in a nuclear fusion device in China. It will allow remote inspection and maintenance of plasma facing components in the vacuum vessel of fusion device without breaking the ultra-high vacuum condition during physical experiments. Its design, mechanism and error prediction strategy have great reference values to the similar robots in vacuum and temperature applications.
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Shanshuang Shi, Huapeng Wu, Yuntao Song and Heikki Handroos
This paper aims to present a study on composite coating films for solid lubrication applied on the surface of bearings and gears, which are exposed to the vacuum vessel of a…
Abstract
Purpose
This paper aims to present a study on composite coating films for solid lubrication applied on the surface of bearings and gears, which are exposed to the vacuum vessel of a tokamak fusion experimental device running under ultra-high vacuum conditions. Experimental advanced superconducting tokamak is a tokamak fusion experimental device running under ultra-high vacuum conditions. To avoid polluting the inner vessel environment, solid lubrication has been applied on the surface of bearings and gears, which are exposed to the vacuum.
Design/methodology/approach
Anti-friction MoS2 coatings integrated with Titanium and Carbon have been developed using the multi-target magnetron sputtering deposition technique. This paper presents the comparative testing of tribological properties for three kinds of MoS2-based coating layers.
Findings
Based on the test results, MoS2-Ti-C coating films are supposed to be the final selection because of the better performance of friction coefficient and lubrication longevity.
Originality/value
Finally, the detailed information has been characterized for the hybrid coatings, which can provide some references for applications of solid lubrications under similar conditions of high vacuum and temperature.
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Tao Zhang, Yuntao Song, Huapeng Wu and Qi Wang
Every geometric model corresponding to a unique feature whose errors of parameters uncorrelated, so the linearization technique can be successfully applied. The solution of a…
Abstract
Purpose
Every geometric model corresponding to a unique feature whose errors of parameters uncorrelated, so the linearization technique can be successfully applied. The solution of a linear least square problem can be applied straightforwardly. This method has advantages especially in calibrate the redundant robot because it’s relatively small. The parameters of kinematics are unique and determined by this algorithm.
Design/methodology/approach
In this paper, a geometric identification method has been studied to estimate the parameters in the Denavit–Hartenberg (DH) model of the robot. Through studying the robot’s geometric features, specific trajectories are designed for calibrating the DH parameters. On the basis of these geometric features, several fitting methods have been deduced so that the important geometric parameters of robots, such as the actual rotation centers and rotate axes, can be found.
Findings
By measuring the corresponding motion trajectory at the end-effector, the trajectory feature can be identified by using curve fitting methods, and the trajectory feature will reflect back to the actual value of the DH parameters.
Originality/value
This method is especially suitable for rigid serial-link robots especially for redundant robots because of its specific calibration trajectory and geometric features. Besides, this method uses geometric features to calibrate the robot which is relatively small especially for the redundant robot comparing to the numerical algorithm.
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Tao Zhang, Yuntao Song, Huapeng Wu, Heikki Handroos, Yong Cheng and Xuanchen Zhang
Remote handling (RH) manipulators have been widely studied for maintenance tasks in fusion reactors. Those tasks always require heavy load, high accuracy and large work space for…
Abstract
Purpose
Remote handling (RH) manipulators have been widely studied for maintenance tasks in fusion reactors. Those tasks always require heavy load, high accuracy and large work space for manipulators. Traditionally, the maintenance of fusion devices always depends on manual RH. With the development of calculating ability, the intelligent automatic maintenance makes it possible for a fusion device instead of the previous manual operation. As the flexibility of arm and the deformation of manipulator will cause problems, which are mainly inaccuracy and lower efficiency. This paper aims to study an effective way to promote the arm behavior to solve these problems.
Design/methodology/approach
By making use of the experimental advanced superconducting tokamak articulated maintenance arm as a platform, a series of experiments is designed to measure errors of kinematics and to collect the database of the flexible arm. Through studying the data and the arm structure, recurrent neural network (RNN) method was adopted to estimate the deformation of flexible arm and eventually compensate deformation in robot control to achieve higher accuracy.
Findings
By means of delicate RNN modeling, errors of kinematics have been reduced to a smaller order than the RH mode. This intelligent maintenance method will also reduce complexity of operations in maintenance.
Originality/value
This paper presents the use of an artificial intelligent algorithm to solve a nonlinear deformation problem of the flexible arm. The results demonstrate that it is efficient in dealing with this problem in fusion application. The RNN’s successful application has also shown that intelligent algorithms can be widely applied in fusion maintenance.
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Manfen Han, Huapeng Wu, Yuntao Song, Yong Cheng and Heikki Handroos
The purpose of this paper is to investigate an intelligent control for water hydraulic position servo system which is intent to be used in remote control robot for fusion reactor…
Abstract
Purpose
The purpose of this paper is to investigate an intelligent control for water hydraulic position servo system which is intent to be used in remote control robot for fusion reactor. The dynamic model of water hydraulic servo control system is built and proportional–integral–derivative (PID) controller is used.
Design/methodology/approach
PID control is the most common control algorithm used in industry and has been a conventional tool used to operate closed-loop control system; however, it is very difficult to achieve high accuracy and fast response by using the traditional way to tune its perimeters. To improve the control performance, optimization algorithm can be applied to search the best parameters of PID. This paper presents a search algorithm using particle swarm with H2 control standards objective function to optimize PID parameters.
Findings
By comparing simulation and mock-up experiments’ results from different control methods, the particle swarm optimization algorithm presents better performance and is more effective for tuning PID parameters.
Originality/value
This paper presents an effective way to ensure safety and efficiency for remote handling maintenances of China Fusion Engineering Test Reactor.
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This paper aims to examine the intensifying efforts by China and the West to harness the clean, limitless energy of nuclear fusion. However, it argues that this “holy grail” of a…
Abstract
Purpose
This paper aims to examine the intensifying efforts by China and the West to harness the clean, limitless energy of nuclear fusion. However, it argues that this “holy grail” of a fusion future is only achievable through an optimal combination of mission-oriented public–private cooperation and genuine intergovernmental cooperation.
Design/methodology/approach
This study deploys a case-study approach, augmented by relevant literature, to analyse the advances in fusion technology.
Findings
Despite purported recent advances in fusion technology, these advances remain largely “proof of concept” experiments rather than commercially viable technologies that enable us to truly harness the infinite power of these “artificial suns”. To achieve the moonshot goal of delivering practicable “net energy gain” from fusion power, this study advocates shedding hubristic political “one-upmanship” amongst rival governments. Further, it urges focussing the ingenuity, along with the financial and scientific resources of all stakeholders (both public and private) across the globe to bring about this “fusion dawn”. Moreover, efforts to deliver fusion power face significant competition from other clean energy sources (wind, solar power and nuclear fission reactors) that are not only technically far less challenging but also economically more viable with their declining cost structures.
Originality/value
This study is possibly one of the few social science papers that examines the prospect of clean, limitless fusion power along with the challenges it faces and its societal implications.
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Heng-Yang Lu, Yi Zhang and Yuntao Du
Topic model has been widely applied to discover important information from a vast amount of unstructured data. Traditional long-text topic models such as Latent Dirichlet…
Abstract
Purpose
Topic model has been widely applied to discover important information from a vast amount of unstructured data. Traditional long-text topic models such as Latent Dirichlet Allocation may suffer from the sparsity problem when dealing with short texts, which mostly come from the Web. These models also exist the readability problem when displaying the discovered topics. The purpose of this paper is to propose a novel model called the Sense Unit based Phrase Topic Model (SenU-PTM) for both the sparsity and readability problems.
Design/methodology/approach
SenU-PTM is a novel phrase-based short-text topic model under a two-phase framework. The first phase introduces a phrase-generation algorithm by exploiting word embeddings, which aims to generate phrases with the original corpus. The second phase introduces a new concept of sense unit, which consists of a set of semantically similar tokens for modeling topics with token vectors generated in the first phase. Finally, SenU-PTM infers topics based on the above two phases.
Findings
Experimental results on two real-world and publicly available datasets show the effectiveness of SenU-PTM from the perspectives of topical quality and document characterization. It reveals that modeling topics on sense units can solve the sparsity of short texts and improve the readability of topics at the same time.
Originality/value
The originality of SenU-PTM lies in the new procedure of modeling topics on the proposed sense units with word embeddings for short-text topic discovery.
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Abstract
Purpose
How does business model design play a role in enabling manufacturing firms’ services? This study aims to investigate the impact of two distinct types of business model design, namely, efficiency-centered business model design (EBMD) and novelty-centered business model design (NBMD), and their effects in balanced and imbalanced configurations, on two types of services: product- and customer-oriented services.
Design/methodology/approach
Using matched survey data of 390 top managers and objective performance data of 195 Chinese manufacturing firms, this study uses hierarchical regression, polynomial regression and response surface analysis to test the hypotheses.
Findings
The results show that while EBMD positively affects product-oriented services, NBMD positively affects customer-oriented services. Both types of services exert a significant influence on firm performance. Furthermore, the degree of product- and customer-oriented services increases with an increasing effort level with a balance between EBMD and NBMD. Asymmetrical, imbalanced configuration effects reveal that the degree of product-oriented services is higher when the EBMD effort exceeds the NBMD effort, and the degree of customer-oriented services is higher when the NBMD effort exceeds the EBMD effort.
Originality/value
This study enriches the understanding of designing business models to facilitate service growth in manufacturing firms, ultimately benefiting firm performance. In addition, exploring balanced and imbalanced configurations of EBMD and NBMD offers new insights into business model dual design research.
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Xu Chu, Yuntao Bai and Baoying Zhu
Digital transformation (DX) is advancing in the post-pandemic era, yet regional disparities remain pronounced. This uneven distribution may be attributed to cities’ doing business…
Abstract
Purpose
Digital transformation (DX) is advancing in the post-pandemic era, yet regional disparities remain pronounced. This uneven distribution may be attributed to cities’ doing business environment. As the doing business environment comprises various components, we aim to explore how these components interact to affect local firms' DX, thereby identifying which configurations of the doing business environment contribute to firms' DX.
Design/methodology/approach
The doing business environment in our study contains seven components: public services, government, legal, innovation, market, human resources and financial services environments. We adopt a fuzzy-set qualitative comparative analysis approach to determine the necessary and sufficient conditions for firms' high-level DX. The sample consists of enterprises listed on the China Science and Technology Innovation Board.
Findings
Firstly, a single doing business environment component is unnecessary for firms to produce a high- or non-high-level DX. Secondly, four configurations of the doing business environment explain firms' high-level DX of three general types: doing business environment configurations (1) dominated by the cost hypothesis, (2) synergised by the cost and resource hypotheses and (3) dominated by the resource hypothesis. Thirdly, the configurational paths generating firms’ high- or non-high-level DX are asymmetric and only one doing business environment configuration will lead to firms' non-high-level DX.
Originality/value
This study presents a ground-breaking exploration of the mechanisms driving firms' DX in terms of the city-level doing business environment and its dual functions. Additionally, we elucidate the reasons for the uneven regional distribution of DX development.
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Tianxiang Yao and Wenrong Cheng
The purpose of this paper is to find a method that has high precision to forecast the energy consumption of China’s manufacturing industry. The authors hope the predicted data can…
Abstract
Purpose
The purpose of this paper is to find a method that has high precision to forecast the energy consumption of China’s manufacturing industry. The authors hope the predicted data can provide references to the formulation of government’s energy strategy and the sustained growth of economy in China.
Design/methodology/approach
First, the authors respectively make use of regression prediction model and grey system theory GM(1,1) model to construct single model based the data of 2001-2010, analyze the advantages and disadvantages of single prediction models. The authors use the data of 2011 and 2012 to test the model. Second, the authors propose combination forecasting model of manufacturing’s energy consumption in China by using standard variance to allocate the weight. Finally, this model is applied to forecast China’s manufacturing energy consumption during 2013-2016.
Findings
The result shows that the combination model is a better one with higher accuracy; the authors can take the model as an effective tool to predict manufacturing’s energy consumption in China. And the energy consumption of China’s manufacturing industry continued to show a steady incremental trend.
Originality/value
This method takes full advantages of the effective information reflected by the single model and improves the prediction accuracy.