Design and implementation of a mobile parallel robot for assembling and machining the fusion reactor vacuum vessel

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Changyang Li ◽

Huapeng Wu ◽

Harri Eskelinen ◽

Haibiao Ji

Keyword(s):

Computer Aided Design ◽

Fusion Reactor ◽

Mechanical Design ◽

Industrial Robot ◽

Parallel Robot ◽

Tig Welding ◽

Inert Gas ◽

Vacuum Vessel ◽

Content Type ◽

Simulation And Optimization

Purpose 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. Design/methodology/approach 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. Findings 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. Originality/value 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.

Download Full-text

A Study on the Angular Distortion Control for the Multi-Pass Butt Weldment of STS 316LN

Materials Science Forum ◽

10.4028/www.scientific.net/msf.580-582.431 ◽

2008 ◽

Vol 580-582 ◽

pp. 431-434 ◽

Cited By ~ 2

Author(s):

Ha Geun Kim ◽

Sang Beom Shin ◽

Dae Soon Kim

Keyword(s):

Fusion Reactor ◽

Control Method ◽

Prediction Equation ◽

Angular Distortion ◽

Vacuum Vessel ◽

Predictive Equation ◽

Bending Rigidity ◽

Distortion Control ◽

Welded Structure ◽

Welding Sequence

The purpose of this study is to establish the proper control method of angular distortion of multi-pass STS 316LN weldment in the vacuum and cryostat vessel of the fusion reactor. To achieve it, the predictive equation of angular distortion in the multi-pass STS 316LN weldment with reference to welding heat input and effective bending rigidity of weldment was established using FEA and experiment. The bending restraint degree of each weldment in the the vacuum vessels of the fusion reactor was evaluated using FEA. Based on the prediction equation of distortion, both proper welding deposit sequence of double sided butt weldment of STS 316LN for cryostat vessel and proper welding sequence for the vacuum vessel were established and verified by the measured distortion of actual welded structure.

Download Full-text

Integrity Assessment of Weld Joints for Vacuum Vessel of Fusion Reactor

Proceedings of the 1992 Annual Meeting of JSME/MMD ◽

10.1299/jsmezairiki.2000.0_613 ◽

2000 ◽

Vol 2000 (0) ◽

pp. 613-614

Author(s):

Takashi SHIMAKAWA ◽

Sabrou USAMI ◽

Koichi KOIZUMI ◽

Kenzo MIYA ◽

Hideo KOBAYASHI

Keyword(s):

Fusion Reactor ◽

Vacuum Vessel ◽

Integrity Assessment ◽

Weld Joints

Download Full-text

Large-Scale Rig for the Characterization of DCC at Sub-Atmospheric Pressure

Volume 2: Nuclear Policy; Nuclear Safety, Security, and Cyber Security; Operating Plant Experience; Probabilistic Risk Assessments; SMR and Advanced Reactors ◽

10.1115/icone2020-16662 ◽

2020 ◽

Author(s):

R. Lo Frano ◽

A. Pesetti ◽

D. Aquaro ◽

M. Olcese

Keyword(s):

Atmospheric Pressure ◽

Large Scale ◽

Fusion Reactor ◽

Scale Up ◽

Small Scale ◽

Vacuum Vessel ◽

Steam Condensation ◽

Main Components ◽

Under Construction ◽

Experimental Rig

Abstract The Direct Contact Condensation (DCC) is the main phenomenon characterizing the steam condensation. It plays an important role for the operation of Vacuum Vessel Pressure Suppression System (VVPSS) tanks, particularly for managing the Ingress of Coolant Event (determining fusion reactor overpressurization). It is safety relevant (key) system of the fusion reactor because by condensing the steam generated during such accident event allows to damp the overpressure. This paper deals with experimental and theoretical analyses of the DCC at sub-atmospheric pressure. The similitude analysis was elaborated to scale up the experimental results obtained in the reduced scale facility: similitude laws are used for the design of large experimental rig. Correlations are defined starting from the water temperature and pressure variation already obtained in the small-scale rig. Furthermore, the experimental rig and its main components accordingly designed (and under construction at the University of Pisa) allow to study at large scale the steam condensation. The testing conditions are presented and discussed.

Download Full-text

Thick SS316 materials TIG welding development activities towards advanced fusion reactor vacuum vessel applications

Journal of Physics Conference Series ◽

10.1088/1742-6596/390/1/012063 ◽

2012 ◽

Vol 390 ◽

pp. 012063 ◽

Cited By ~ 2

Author(s):

B Ramesh Kumar ◽

R Gangradey

Keyword(s):

Fusion Reactor ◽

Tig Welding ◽

Vacuum Vessel

Download Full-text

Identifiable Parameter Analysis for the Kinematic Calibration of a Hybrid Robot

Volume 6: 35th Mechanisms and Robotics Conference, Parts A and B ◽

10.1115/detc2011-47573 ◽

2011 ◽

Cited By ~ 1

Author(s):

Yongbo Wang ◽

Huapeng Wu ◽

Heikki Handroos

Keyword(s):

Degrees Of Freedom ◽

Differential Evolution Algorithm ◽

Parallel Robot ◽

Error Model ◽

Parameter Analysis ◽

Vacuum Vessel ◽

Unknown Parameters ◽

Mean Values ◽

Global Optimizer ◽

Kinematic Error Model

In this paper, a statistical method for the determination of the identifiable parameters of a hybrid serial-parallel robot IWR (Intersector Welding Robot) is presented. This method is based on the Markov Chain Monte Carlo (MCMC) algorithm to analyze the posterior distribution and correlation of the error parameters. Differential Evolution algorithm is employed to search a global optimizer as initial values for the random sampling of MCMC. The robot under study has ten degrees of freedom (DOF) and will be used to carry out welding, machining, and remote handing for the assembly of vacuum vessel of the international thermonuclear experimental reactor (ITER). In this paper, a kinematic error model which involves assembling and manufacturing error parameters is developed for the proposed robot. Based on this error model, the mean values of the unknown parameters are statistically analyzed and estimated using the proposed method. Computer simulations reveal that all the reduced independent kinematic parameters can be identified with the complete pose measurements. Results also demonstrate that the identification method is robust and effective with the given measurement noise.

Download Full-text