Development of a water hydraulics remote handling system for ITER maintenance Greg Dubus gregory.dubus@cea.fr IARP/EURON RISE 08 Benicàssim, 8 th January 2008 1
Agenda Overview of the CEA-List Interactive Robotics Unit Four units Application domains R&D Activities Computer Aided Force Feedback Teleoperation R&D program : water hydraulic robot for Fusion The ITER maintenance Need for a WH manipulator The Maestro system System description Design, control and performances of the manipulator Graphical supervision and assistance for enhanced teleoperation tasks Feasibility demonstration inside the Divertor Test Platform (DTP) Adaptation to the ITER hazardous conditions Redesign of the vane actuator Developments of a water hydraulics pressure servovalve Further developments 2
Overview of the CEA-List Interactive Robotics Unit Four units CEA: French Nuclear Agency Nuclear energy R&D Fundamental Research Science of Materials Science of the Living Defense Program Technology Research for industry Interactive Robotics Unit 3
Overview of the CEA-List Interactive Robotics Unit Application domains - Nuclear applications (maintenance, post accident intervention, dismantling ) Fuel Power Plant Recycling R&D Fuel Reprocessing Plant - Handicap, health ITER COGEMA-LA HAGUE - Security 4
Overview of the CEA-List Interactive Robotics Unit R&D Activities Robotics control Autonomous localization and navigation Manipulation, telemanipulation and cobotics Mechatronics Innovative robotics technology - Architecture - Actuator - Robustness to hostile environment Robotics modeling and design 5
Overview of the CEA-List Interactive Robotics Unit Computer Aided Force Feedback Teleoperation Classic Master-Slave Manipulator Computer based telemanipulation POSITION EFFORT CONTROL Master Arm BILATERAL MASTER SLAVE CONTROL TAO2000 POSITION EFFORT CONTROL Slave Arm 6
R&D program : water hydraulic robot for Fusion The ITER maintenance The ITER vessel will be a restricted working environment : Hostile to humans Tritium & Beryllium Gamma(30,000 Sv/hr, natural radioactivity in France: 2.5 msv/yr) Neutrons Temperature (20-50 C, 300 C for the In-Vessel Viewing System (IVVS)) Residual Magnetic Field (6T for the IVVS) Vacuum Hostile to Remote Handling (RH) equipment Inaccessible due to the scale Inaccessibility due to the required cleanliness level 7
R&D program : water hydraulic robot for Fusion The ITER maintenance The ITER vessel will be a restricted working environment : Hostile to humans Tritium & Beryllium Gamma(30,000 Sv/hr, natural radioactivity in France: 2.5 msv/yr) Neutrons Temperature (20-50 C, 300 C for the In-Vessel Viewing System (IVVS)) Residual Magnetic Field (6T for the IVVS) Vacuum Hostile to Remote Handling (RH) equipment Inaccessible due to the scale Inaccessibility due to the required cleanliness level 8
R&D program : water hydraulic robot for Fusion Need for a WH manipulator High radiation level Constrained environment High payload needed No pollution 9
R&D program : water hydraulic robot for Fusion Need for a WH manipulator High radiation level Constrained environment High payload needed No pollution telemanipulator 10
R&D program : water hydraulic robot for Fusion Need for a WH manipulator High radiation level Constrained environment High payload needed No pollution hydraulic telemanipulator 11
R&D program : water hydraulic robot for Fusion Need for a WH manipulator High radiation level Constrained environment High payload needed No pollution Water hydraulic telemanipulator 12
The Maestro system System description 13
The Maestro system Design, control and performances of the manipulator (1/2) 120kg / 2.4m long Titanium arm 6 DOF Actuators technology based on rotary hydraulic joints Payload capacity up to 100kg Easy to decontaminate Pressure servovalves Resolvers Tool changer In-robot 220 V power supply (no tool umbilical) rad-tolerant: designed for 100kGy (10kGy for version with embedded controller) Controlled thanks to TAO2000 14
The Maestro system Design, control and performances of the manipulator (2/2) Flow-control servovalve Pressure-control servovalve To a current input this servovalve supplies a very accurate pressure difference output instead of a flow rate in the case of flow-control servovalves. Main advantages: improvement of the performances better stability of the force control loop better rad tolerance (no active electronics) 15
The Maestro system Graphical supervision and assistance for enhanced teleoperation tasks MAGRITTE: Graphical 3D interface for robot supervision Coupled to TAO2000 controller Imports CAD models Control tools weight compensation Specific processes modules (cutting, welding, grinding ) 16
The Maestro system Graphical supervision and assistance for enhanced teleoperation tasks 3 different features to prevent collisions: Passive collision avoidance Real-time failure and collision detection Active collision avoidance 17
The Maestro system Graphical supervision and assistance for enhanced teleoperation tasks 3 different features to prevent collisions: Passive collision avoidance Pre-collision detection based on robot position measurement Stops the current robot control mode to prevent collision Needs environment CAD model Needs near-real-time network link between robot controller and supervision WorkStation (WS) Real-time failure and collision detection Active collision avoidance 18
The Maestro system Graphical supervision and assistance for enhanced teleoperation tasks 3 different features to prevent collisions: Passive collision avoidance Real-time failure and collision detection Real-Time failure or post-collision detection based on robot dynamic model Environment CAD model free Comparison between expected torque (model) and real torque (sensors) Active collision avoidance 19
The Maestro system Graphical supervision and assistance for enhanced teleoperation tasks 3 different features to prevent collisions: Passive collision avoidance Real-time failure and collision detection Active collision avoidance Collision avoidance based on robot position measurement Keeps the current robot control mode active though preventing collision by generating virtual repulsive torque Needs environment CAD model and near-real-time network link between controller and WS 20
The Maestro system Graphical supervision and assistance for enhanced teleoperation tasks 3 different features to prevent collisions: Passive collision avoidance Real-time failure and collision detection Active collision avoidance Collision avoidance based on robot position measurement Keeps the current robot control mode active though preventing collision by generating virtual repulsive torque Needs environment CAD model and near-real-time network link between controller and WS 21
The Maestro system Feasibility demonstrations inside the Divertor Test Platform (DTP) 22
Adaptation to the ITER hazardous conditions Redesign of the vane actuator (1/2) Starting from the oil hydraulic version of the MAESTRO slave-arm, redesign for pure water applications of the elbow actuator. Adaptability study driving requirements: To use corrosion resistant materials To reduce clearances (direct impact on internal leaks due to water s low viscosity) To prevent contact between water and components with poor corrosion resistance To adapt seal materials and properties to water 23
Adaptation to the ITER hazardous conditions Redesign of the vane actuator (2/2) Reversibility tests = Good representation of force control loop quality (active compensation models) Torque (N.m) Real torque during manual movement Torque (N.m) 80 Torque felt by the operator 300 60 200 100 40 0 20-100 0-200 -300-20 24 25 26 27 28 29 30 31 32 33 34 35 Time (s) -40 24 25 26 27 28 29 30 31 32 33 34 35 Time (s) Performance achieved with water was equivalent or even better than with oil Endurance tests were carried out to qualify the joint for RH manipulation 24
Adaptation to the ITER hazardous conditions Developments of a water hydraulics pressure servovalve (1/2) Development of a pressure control servovalve dedicated to water hydraulics applications that fits the space constraints of a MAESTRO manipulator 25
Adaptation to the ITER hazardous conditions Developments of a water hydraulics pressure servovalve (2/2) 90 80 Magnitude (db) 70 60 50 Reduction of the dead volumes 40 30 50% 20 10 1 25% 10 2 10 3 12,5% About 0% Frequency (Hz) Quasi-closed apertures Phase ( ) Closed apertures 0-50 -100 Dead volume size / actuator volume -150-200 -250 Reduction of the dead volumes -300-350 -400 10 1 10 2 10 3 Frequency (Hz) 26
Adaptation to the ITER hazardous conditions Further developments Qualification of the water hydraulics joint equipped with a pressure servovalve instead of the flow control preactuator Redesign and machining of a new prototype of pressure servovalve, limiting the internal leakage Realisation of a complete water hydraulics Maestro arm 27
Bonus 28
Thank you for your attention 29
Question time 30
Index 31