WO2012126559A3 - Système de nettoyage permettant de nettoyer des installations de miroir cylindro-parabolique et procédé de nettoyage utilisant ledit système - Google Patents

Système de nettoyage permettant de nettoyer des installations de miroir cylindro-parabolique et procédé de nettoyage utilisant ledit système Download PDF

Info

Publication number
WO2012126559A3
WO2012126559A3 PCT/EP2012/000745 EP2012000745W WO2012126559A3 WO 2012126559 A3 WO2012126559 A3 WO 2012126559A3 EP 2012000745 W EP2012000745 W EP 2012000745W WO 2012126559 A3 WO2012126559 A3 WO 2012126559A3
Authority
WO
WIPO (PCT)
Prior art keywords
cleaning
navigation
parabolic trough
trough collector
vehicles
Prior art date
Application number
PCT/EP2012/000745
Other languages
English (en)
Other versions
WO2012126559A2 (fr
Inventor
Carlos Javier VICENTE PEÑA
Francesc MASSABE MUÑOZ
José Ramón VILLA NAVARRO
Soledad GARRIDO ORTIZ
Original Assignee
Sener, Ingeniería Y Sistemas, S.A.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sener, Ingeniería Y Sistemas, S.A. filed Critical Sener, Ingeniería Y Sistemas, S.A.
Priority to US13/995,746 priority Critical patent/US20130284207A1/en
Priority to MA35814A priority patent/MA34602B1/fr
Priority to AU2012231081A priority patent/AU2012231081A1/en
Publication of WO2012126559A2 publication Critical patent/WO2012126559A2/fr
Publication of WO2012126559A3 publication Critical patent/WO2012126559A3/fr
Priority to IL225728A priority patent/IL225728A0/en

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
    • F24S40/00—Safety or protection arrangements of solar heat collectors; Preventing malfunction of solar heat collectors
    • F24S40/20—Cleaning; Removing snow
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B08—CLEANING
    • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
    • B08B1/00—Cleaning by methods involving the use of tools
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B08—CLEANING
    • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
    • B08B1/00—Cleaning by methods involving the use of tools
    • B08B1/10—Cleaning by methods involving the use of tools characterised by the type of cleaning tool
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B08—CLEANING
    • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
    • B08B1/00—Cleaning by methods involving the use of tools
    • B08B1/30—Cleaning by methods involving the use of tools by movement of cleaning members over a surface
    • B08B1/32—Cleaning by methods involving the use of tools by movement of cleaning members over a surface using rotary cleaning members
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B08—CLEANING
    • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
    • B08B3/00—Cleaning by methods involving the use or presence of liquid or steam
    • B08B3/02—Cleaning by the force of jets or sprays
    • B08B3/022—Cleaning travelling work
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B08—CLEANING
    • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
    • B08B3/00—Cleaning by methods involving the use or presence of liquid or steam
    • B08B3/02—Cleaning by the force of jets or sprays
    • B08B3/024—Cleaning by means of spray elements moving over the surface to be cleaned
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
    • B25J11/00—Manipulators not otherwise provided for
    • B25J11/008—Manipulators for service tasks
    • B25J11/0085—Cleaning
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
    • B25J5/00—Manipulators mounted on wheels or on carriages
    • B25J5/007—Manipulators mounted on wheels or on carriages mounted on wheels
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
    • B25J9/00—Programme-controlled manipulators
    • B25J9/0084—Programme-controlled manipulators comprising a plurality of manipulators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
    • F24S23/00—Arrangements for concentrating solar-rays for solar heat collectors
    • F24S23/70—Arrangements for concentrating solar-rays for solar heat collectors with reflectors
    • F24S23/74—Arrangements for concentrating solar-rays for solar heat collectors with reflectors with trough-shaped or cylindro-parabolic reflective surfaces
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
    • F24S50/00—Arrangements for controlling solar heat collectors
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D1/00—Control of position, course, altitude or attitude of land, water, air or space vehicles, e.g. using automatic pilots
    • G05D1/02—Control of position or course in two dimensions
    • G05D1/021—Control of position or course in two dimensions specially adapted to land vehicles
    • G05D1/0231—Control of position or course in two dimensions specially adapted to land vehicles using optical position detecting means
    • G05D1/0238—Control of position or course in two dimensions specially adapted to land vehicles using optical position detecting means using obstacle or wall sensors
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D1/00—Control of position, course, altitude or attitude of land, water, air or space vehicles, e.g. using automatic pilots
    • G05D1/02—Control of position or course in two dimensions
    • G05D1/021—Control of position or course in two dimensions specially adapted to land vehicles
    • G05D1/0268—Control of position or course in two dimensions specially adapted to land vehicles using internal positioning means
    • G05D1/027—Control of position or course in two dimensions specially adapted to land vehicles using internal positioning means comprising intertial navigation means, e.g. azimuth detector
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D1/00—Control of position, course, altitude or attitude of land, water, air or space vehicles, e.g. using automatic pilots
    • G05D1/02—Control of position or course in two dimensions
    • G05D1/021—Control of position or course in two dimensions specially adapted to land vehicles
    • G05D1/0276—Control of position or course in two dimensions specially adapted to land vehicles using signals provided by a source external to the vehicle
    • G05D1/0278—Control of position or course in two dimensions specially adapted to land vehicles using signals provided by a source external to the vehicle using satellite positioning signals, e.g. GPS
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B10/00—Integration of renewable energy sources in buildings
    • Y02B10/20—Solar thermal
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/40—Solar thermal energy, e.g. solar towers

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Remote Sensing (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Robotics (AREA)
  • Sustainable Energy (AREA)
  • Combustion & Propulsion (AREA)
  • Chemical & Material Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Thermal Sciences (AREA)
  • Sustainable Development (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Automation & Control Theory (AREA)
  • Electromagnetism (AREA)
  • Cleaning By Liquid Or Steam (AREA)
  • Control Of Position, Course, Altitude, Or Attitude Of Moving Bodies (AREA)

Abstract

La présente invention a trait à un système de nettoyage permettant de nettoyer des installations de miroir cylindro-parabolique, lequel système est constitué de véhicules de nettoyage (5) dotés d'un moyen de déplacement (7), d'un moyen de nettoyage et d'un moyen de commande. Les véhicules de nettoyage (5) sont autonomes et indépendants les uns des autres et sont dotés d'un moyen de navigation (11, 12) qui guide et dirige le véhicule de nettoyage (5) lors de son déplacement le long de l'installation. Le moyen de navigation est constitué d'un système de navigation relatif doté d'une unité d'inertie et de capteurs de distance (12) qui mesurent la distance du véhicule de nettoyage (5) jusqu'au miroir cylindro-parabolique (1), et d'un système de navigation absolu doté d'un sous-système de positionnement GPS. Un système de commande intègre et commande le moyen de nettoyage, le moyen de commande, le moyen de déplacement (7) et le moyen de navigation (11, 12) des véhicules de nettoyage (5).
PCT/EP2012/000745 2011-03-18 2012-02-14 Système de nettoyage permettant de nettoyer des installations de miroir cylindro-parabolique et procédé de nettoyage utilisant ledit système WO2012126559A2 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
US13/995,746 US20130284207A1 (en) 2011-03-18 2012-02-14 Cleaning system for cleaning parabolic trough collector plants and cleaning method using said system
MA35814A MA34602B1 (fr) 2011-03-18 2012-02-14 Système de nettoyage permettant de nettoyer des installations de miroir cylindro-parabolique et procédé de nettoyage utilisant ledit système
AU2012231081A AU2012231081A1 (en) 2011-03-18 2012-02-14 Cleaning system for cleaning parabolic trough collector plants and cleaning method using said system
IL225728A IL225728A0 (en) 2011-03-18 2013-04-11 A cleaning system for parabolic trough collectors for plants and a method for cleaning according to the same system

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ES201130389A ES2398159B1 (es) 2011-03-18 2011-03-18 Sistema de limpieza de plantas de colectores cilindro-parabólicos y método de limpieza que emplea dicho sistema.
ESP201130389 2011-03-18

Publications (2)

Publication Number Publication Date
WO2012126559A2 WO2012126559A2 (fr) 2012-09-27
WO2012126559A3 true WO2012126559A3 (fr) 2012-12-06

Family

ID=45787155

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2012/000745 WO2012126559A2 (fr) 2011-03-18 2012-02-14 Système de nettoyage permettant de nettoyer des installations de miroir cylindro-parabolique et procédé de nettoyage utilisant ledit système

Country Status (7)

Country Link
US (1) US20130284207A1 (fr)
AU (1) AU2012231081A1 (fr)
CL (1) CL2013001171A1 (fr)
ES (1) ES2398159B1 (fr)
IL (1) IL225728A0 (fr)
MA (1) MA34602B1 (fr)
WO (1) WO2012126559A2 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104942815A (zh) * 2015-07-08 2015-09-30 安庆联泰电子科技有限公司 一种全自动挂式空调外壳清洗机器人

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2776216B1 (fr) * 2011-11-11 2022-08-31 iRobot Corporation Appareil robot et méthode de commande pour reprendre le fonctionnement après une pause.
CN102950122A (zh) * 2012-11-12 2013-03-06 华南理工大学 一种用于光伏电池阵列的移动干式除尘装置
CN103071634B (zh) * 2012-12-31 2016-01-20 浙江中控太阳能技术有限公司 一种定日镜无水清洁装置
US10012618B2 (en) 2015-02-18 2018-07-03 Saudi Arabian Oil Company Deployment mechanism for passive normalization of a probe relative to a surface
US10305419B1 (en) * 2015-06-22 2019-05-28 Nextracker Inc. Washing system for solar panels
CN104959331B (zh) * 2015-07-08 2018-08-31 宿迁市泰普制冷设备有限公司 一种全自动挂式空调外壳清洗机器人用清理装置
US10190803B2 (en) 2015-09-24 2019-01-29 Dynamis Solutions, Llc System and method for cleaning surfaces
ES2632222B1 (es) * 2015-10-08 2018-06-21 Tecnove Security S.L. Vehículo para limpieza de heliostatos, placas solares fotovoltaicas o placas solares térmicas
CN106824855B (zh) * 2017-03-10 2019-07-12 浙江中控太阳能技术有限公司 一种跨越式定日镜镜面清洗车
ES2682967B1 (es) * 2017-03-22 2019-07-11 Ecilimp Termosolar S L Dispositivo para limpieza de panel concentrador solar equipado para ahorro de agua
US20190187721A1 (en) * 2017-12-15 2019-06-20 Ankobot (Shanghai) Smart Technologies Co., Ltd. Control method and system, and mobile robot using the same
CN108971045A (zh) * 2018-10-24 2018-12-11 中国工程物理研究院激光聚变研究中心 用于光学元件在线表面洁净处理的装置
US20230042233A1 (en) * 2020-01-16 2023-02-09 Airtouch Solar Ltd. Robotic trolly for moving a cleaning robot and a system that includes a cleaning robot and the robotic trolly

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050267631A1 (en) * 2004-05-14 2005-12-01 Ju-Sang Lee Mobile robot and system and method of compensating for path diversions
US20090281661A1 (en) * 2008-04-24 2009-11-12 Evolution Robotics Application of localization, positioning & navigation systems for robotic enabled mobile products
EP2153914A1 (fr) * 2008-08-08 2010-02-17 Ingenieria y Marketing, S.A. Procédé pour le nettoyage de miroirs à section parabolique d'une centrale thermosolaire et appareil pour la réalisation dudit procédé
CN101694327A (zh) * 2009-10-22 2010-04-14 北京中航空港通用设备有限公司 槽式太阳能热发电集热器清洗车
US20100206294A1 (en) * 2009-02-13 2010-08-19 Jason Blair Heliostat field cleaning system
WO2010142837A1 (fr) * 2009-06-12 2010-12-16 Abengoa Solar New Tecnologies, S.A. Véhicule et procédé de nettoyage pour collecteurs solaires de type cylindro-parabolique
EP2295158A1 (fr) * 2009-09-09 2011-03-16 MULAG FAHRZEUGWERK Heinz Wössner GmbH & CO. KG Appareil de nettoyage pour centrales thermosolaires

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3354004A (en) 1964-11-17 1967-11-21 Ibm Method for enhancing efficiency of recovery of semi-conductor material in perturbable disproportionation systems
US3481346A (en) 1966-05-31 1969-12-02 Automatic Car Wash Distributor Car washing device
ITFI940032A1 (it) 1994-02-17 1995-08-17 Carlo Pennatini Attrezzatura per la pulizia di superfici elevate dal suolo quali super fici verticali, volte, anche a profilo complesso, ad esempio pareti di
ES1034481Y (es) 1996-06-21 1997-06-01 Sautu Jose Antonio Villanueva Maquina perfeccionada aplicable a la limpieza de tuneles, paredes y similares.
EP1380482B1 (fr) 2002-07-09 2005-10-26 WashTec Holding GmbH Portique de lavage pour véhicules
DE102004036094B4 (de) 2004-07-24 2007-11-22 Deutsches Zentrum für Luft- und Raumfahrt e.V. Waschapparat für einen Parabolrinnenkollektor
JP4477685B1 (ja) * 2008-12-26 2010-06-09 三井造船株式会社 清掃ロボットシステム及びその制御方法
ES1069495U (es) 2009-01-09 2009-04-01 Solar Bright, S.L. Vehiculo autonomo para la limpieza de placas solares.
WO2010106195A1 (fr) 2009-03-16 2010-09-23 Voith Turbo, S.A. Équipement pour le nettoyage des collecteurs cylindrico-paraboliques dans des usines à énergie solaire thermoélectrique
US8448652B2 (en) * 2010-03-26 2013-05-28 Sunpower Corporation Solar system cleaning apparatus

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050267631A1 (en) * 2004-05-14 2005-12-01 Ju-Sang Lee Mobile robot and system and method of compensating for path diversions
US20090281661A1 (en) * 2008-04-24 2009-11-12 Evolution Robotics Application of localization, positioning & navigation systems for robotic enabled mobile products
EP2153914A1 (fr) * 2008-08-08 2010-02-17 Ingenieria y Marketing, S.A. Procédé pour le nettoyage de miroirs à section parabolique d'une centrale thermosolaire et appareil pour la réalisation dudit procédé
US20100206294A1 (en) * 2009-02-13 2010-08-19 Jason Blair Heliostat field cleaning system
WO2010142837A1 (fr) * 2009-06-12 2010-12-16 Abengoa Solar New Tecnologies, S.A. Véhicule et procédé de nettoyage pour collecteurs solaires de type cylindro-parabolique
EP2295158A1 (fr) * 2009-09-09 2011-03-16 MULAG FAHRZEUGWERK Heinz Wössner GmbH & CO. KG Appareil de nettoyage pour centrales thermosolaires
CN101694327A (zh) * 2009-10-22 2010-04-14 北京中航空港通用设备有限公司 槽式太阳能热发电集热器清洗车

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
DATABASE WPI Week 201029, Derwent World Patents Index; AN 2010-E62051, XP002685118 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104942815A (zh) * 2015-07-08 2015-09-30 安庆联泰电子科技有限公司 一种全自动挂式空调外壳清洗机器人

Also Published As

Publication number Publication date
IL225728A0 (en) 2013-06-27
AU2012231081A1 (en) 2013-05-02
WO2012126559A2 (fr) 2012-09-27
US20130284207A1 (en) 2013-10-31
ES2398159B1 (es) 2014-01-17
MA34602B1 (fr) 2013-10-02
CL2013001171A1 (es) 2013-09-06
ES2398159A1 (es) 2013-03-14

Similar Documents

Publication Publication Date Title
WO2012126559A3 (fr) Système de nettoyage permettant de nettoyer des installations de miroir cylindro-parabolique et procédé de nettoyage utilisant ledit système
WO2013003504A3 (fr) Système de priorité en rapport avec des feux de signalisation, basé sur des temps d'arrivée estimés
WO2013169309A3 (fr) Système autonome et procédé d'évitement de débris orbitaux pour satellite
ATE554990T1 (de) Verfahren für die steuerung eines fahrerassistenzsystems und fahrerassistenzsystem
BR102012010505A8 (pt) Método para alinhamento de um trator e um implemento
FR2994279B1 (fr) Procede de controle de l'integrite de stations de radio-navigation dans un systeme d'augmentation par satellite
WO2015073103A3 (fr) Recherches de véhicule sans pilote
MX2016011013A (es) Compensacion de movimiento para sensores de vehiculo a bordo.
EP2555072A3 (fr) Procédé et système pour diriger un aéronef de manière autonome vers un aire d'atterrissage de secours en utilisant des capteurs à bord
CA2862565A1 (fr) Appareil destine a ajuster l'orientation d'une eolienne
EP2821876A3 (fr) Procédé de planification d'itinéraire, unité de planification d'itinéraire et dispositif mobile autonome
WO2012115920A3 (fr) Suivi d'objet et manœuvres de direction destinées à des véhicules de manutention de matériaux
WO2008129236A3 (fr) Système de guidage de véhicule
WO2012143238A3 (fr) Commande de la dynamique de mouvement d'un véhicule comprenant les systèmes gnss et ins
EP2784617A3 (fr) Système de coordination de véhicules de travail
WO2010048611A8 (fr) Commande et systèmes pour véhicules à conduite autonome
WO2012047980A3 (fr) Diagnostic et réparation pour véhicules autonomes
FR3017096B1 (fr) Procede de commande d'une manoeuvre de deplacement automatique d'un vehicule automobile
WO2013188598A3 (fr) Fusion de données de capteurs et de cartes au moyen d'une optimisation basée sur une contrainte
FR2993376B1 (fr) Procede de controle de trajectoire d'un vehicule autonome a roues directrices
EP2372304A3 (fr) Système de reconnaissance de position de véhicule
EP2421742A4 (fr) Dispositif de commande de direction de véhicule autonome, véhicule autonome présentant celui-ci et procédé de commande de direction de véhicule autonome
IL194893A0 (en) Method and system for autonomous tracking of a mobile target by an unmanned aerial vehicle
WO2009035603A3 (fr) Système de contrôle automatique de lame doté d'un système de navigation globale par satellite intégré et détecteurs d'inertie
WO2012088034A3 (fr) Système de distributeur de carburant et procédé utilisant un détecteur de présence de véhicule

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 225728

Country of ref document: IL

WWE Wipo information: entry into national phase

Ref document number: 2013001171

Country of ref document: CL

ENP Entry into the national phase

Ref document number: 2012231081

Country of ref document: AU

Date of ref document: 20120214

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 13995746

Country of ref document: US

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 12706774

Country of ref document: EP

Kind code of ref document: A2