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In large equipment and highly complex confined workspaces, the maintenance is usually carried out by snake-arm robots with equal cross-sections. However, the equal cross-sectional design results in the snake arm suffering from stress concentration and restricted working space. The purpose of this paper is to design a variable cross-section elephant trunk robot (ETR) that can address these shortcomings through bionic principles.

This paper proposes a cable-driven ETR to explore the advantages and inspiration of variable cross-section features for hyper-redundant robot design. For the kinematic characteristics, the influence of the variable cross-section design on the maximum joint angle of the ETR is analysed using the control variables method and the structural parameters are selected. Based on the biological inspiration of the whole elephant trunk following the movement of the trunk tip, a trajectory-tracking algorithm is designed to solve the inverse kinematics of the ETR.

Simulation and test results show the unique advantages of the proposed variable cross-section ETR in kinematics and forces, which can reduce stress concentrations and increase the flexibility of movement.

This paper presents a design method for a variable cross-section ETR for confined working spaces, analyses the kinematic characteristics and develops a targeted trajectory control algorithm.

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.

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.

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.

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.

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.

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.

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.

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.

This paper aims to present a detailed mechanical design of a seven-degrees-of-freedom mobile parallel robot for the tungsten inert gas (TIG) welding and machining processes in fusion reactor. Detailed mechanical design of the robot is presented and both the kinematic and dynamic behaviors are studied.

First, the model of the mobile parallel robot was created in computer-aided design (CAD) software, then the simulation and optimization of the robot were completed to meet the design requirements. Then the robot was manufactured and assembled. Finally, the machining and tungsten inert gas (TIG) welding tests were performed for validation.

Currently, the implementation of the robot system has been successfully carried out in the laboratory. The excellent performance has indicated that the robot’s mechanical and software designs are suitable for the given tasks. The quality and accuracy of welding and machining has reached the requirements.

This mobile parallel industrial robot is particularly used in fusion reactor. Furthermore, the structure of the mobile parallel robot can be optimized for different applications.

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.

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.

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.

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.

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.

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.

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.

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.

The purpose of this paper is to build up a parallel robot for assembling, machining and repairing of the vacuum vessel of the international thermonuclear experimental reactor (ITER).

The process of assembling and machining of the vacuum vessel need a special robot. By studying the structure of the vacuum vessel, a novel parallel robot is built, which has ten degrees of freedom driven by water hydraulic cylinders and electrical servo motors. Kinematic models for the redundant degree robot have been defined. A prototype has been built. Experiments for machine cutting and laser welding were carried out.

The parallel robot is capable of holding all necessary machining tools and welding end‐effectors in all positions accurately and stably inside the vacuum vessel sector. The kinematic models appeared to be complex because of the redundant structure of the robot, and an optimization algorithm ensuring the maximum stiffness during the robot motion helps to find the solution in the trajectory planning. The entire design and testing process of the robot appeared to be a very complex task due to the high specialization of the manufacturing technology needed in the ITER reactor, while the results demonstrate the applicability of the proposed solutions quite well.

Offers not only a device but also a methodology for the assembling and repairing of ITER by means of a parallel robot.

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.

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.

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.

This paper presents an effective way to ensure safety and efficiency for remote handling maintenances of China Fusion Engineering Test Reactor.

An increasing number of Chinese enterprises are involved in cross-border mergers and acquisitions (M&As). However, few Chinese enterprises have achieved successful integration, which plays a critical role in enhancing performance. The important field of cultural integration is currently facing major challenges. To identify the reasons for these challenges, studies have analyzed why cultural integration succeeds or fails and have suggested that cultural differences between acquiring and acquired enterprises are the primary obstacles to cultural integration. However, it is unclear how success can be achieved. The paper aims to focus on cultural integration from the perspective of acculturation to describe the penetration of cultural elements in M&As.

In adopting acculturation as our theoretical lens, the authors use the case study method to answer the following research question: “how can the cultural integration of Chinese enterprises be successfully achieved?” Two typical cases are examined: Lenovo’s cultural integration with IBM’s personal computer (PC) division and Haier’s cultural integration with Sanyo home appliance. First, using the exploratory case study method, the Lenovo–IBM PC division case is analyzed. The characteristics and relationships between cultural environments, employee adoption methods and acculturation patterns are summarized to reveal a cultural integration path. Second, the Haier–Sanyo home appliance case is analyzed using the confirmative case study method to test the findings of the Lenovo–IBM PC division case.

The results indicate that it is critical to achieve a dynamic fit between cultural environments, employee adoption methods and acculturation patterns during each stage of cultural integration (exploration, experimentation, reinforcement and fixing). The three constructs of these stages reflect the following evolutionary paths: “isolate-introduce-learning-chance taking”, “detecting-icebreaking-interacting-remodeling” and “specialized sections-senior managers-managers-employees”.

These findings contribute to the development of cultural integration and acculturation theories and serve as a reference for Chinese enterprises wishing to implement cultural integration strategies.