Salvador Esque

Development of Water Hydraulic Remote Handling System for Divertor Maintenance of ITER

In hostile industrial environments where human access could be a health risk, a reliable and flexible teleoperation system is an eminent need. ITER is such an example where a dexterous teleoperation system is required for remote handling tasks in a nuclear environment. The compactness of space, high load capacity and reliability makes hydraulic manipulator an obvious choice. However, possible oil leakage from traditional hydraulic systems and the characteristics of water (fire and environmentally safe, chemically neutral, not activated, not affected by radiation) makes the use of water hydraulics the only choice. This paper describes the development of teleoperation system for ITER consisting of a water hydraulic manipulator as a slave, a commercial haptic device as a master, a human machine interface to assist the operator and a graphical system providing a virtual 3D view of the environment.

Techniques for Studying a Mobile Hydraulic Crane in Virtual Reality

Abstract Mobile hydraulic applications are exposed to changing environmental conditions and working processes. Furthermore, the fact that those systems consist of mechanical, fluid power and electronic control parts, make the design phase of the product to become complex. In a product development process, system configurations, components selections and parameter optimization must be accomplished in an evaluation-iteration method until fulfilling the performance specification. Replacing real physical prototypes by mathematical models and virtual prototyping in the design process is a major benefit in terms of reducing costs and time in the design phase. This paper introduces a modular method that generates dynamic models for a mobile hydraulic crane and a 3D graphical interface for visualizing of the simulation results in real-time. From the visual feedback provided by the interface, the user interacts with the course of the simulation by driving the crane model with joystick controllers. Such a tool is ideal to be utilised in virtual prototyping, since user can virtually drive and test the prototype and evaluate the system behaviour in real-time. The simulator also allows the user to instantly modify parameters and components of the model. A two degree of freedom hydraulically-driven crane is studied as an example.

ITER Divertor Maintenance: Development of a Control System for the Remote Handling of the Divertor Cassette Mover

Remote handling devices are being used to carry out the maintenance tasks in the divertor area of the ITER. One of the main challenging operations is the installation and transportation of Divertor Cassettes in and out from the vessel. This paper deals with the development of the control system for such remotely operated devices, with special emphasis on the tools, mock-ups and virtual prototypes employed to develop the high level control software and the water-hydraulics position servos controllers. Preliminary studies showing the effect of irradiation in hydraulic cylinder seals are also presented.

Numerical Integration of Pressure Build-Up Volumes Using an L-Stable Rosenbrock Method

Simulation of fluid power systems has become a tool widely used for testing, designing and virtual prototyping. The choice of a numerical integration method for solving stiff systems of ordinary differential equations is a key factor for achieving proper stability and computational efficiency during simulation. Whereas widely used A-stable methods require small integration step sizes in order to avoid numerical oscillations when solving numerically stiff problems, the L-stable Rosenbrock method presented in this paper can take large steps. The method is implemented with an estimator of the local truncation error and a predictor of the step size. Simulations results show the good performance of the integrator in terms of both stability and efficiency.Copyright