Marin Galic_Wind Turbine Blade Inspection by Robots

Wind Turbine Blade Inspection

By Robots

Robotics - 311.022

Marin Galic

• Matrikelnummer: -

• Studienkennzahl: ERASMUS

• Fakultet elektrotehnike i računarstva,

Sveučilište u Zagrebu (Faculty of Electrical

Engineering and Computing, University of

Zagreb)

• Technische Universität Wien, Österreich

(Vienna University of Technology, Austria)

• e-mail: -

Marin Galic was born on 27. October 1990 in Vir (Bosnia

and Herzegovina). First he went to elementary school in Vir, a

small village in the west Herzegovina. With age of 15 he

decided to visit high school “Gimnazija Fra Grge Martica” in

Posušje. In next four years he was active in few high schools

project such as charities and Grga magazine section. After he

finished his high school in 2009, he went to Zagreb (Croatia)

to study electrical engineering on Faculty of Electrical

Engineering and Computing, University of Zagreb.

Curriculum Vitae

After three years of studying, he became a Bachelor of

Science in Electrical Engineering and Information Technology.

From the beginning of his study he was interesting in

Renewable Energy Sources, especially in Wind Energy.

During this time he worked on Seminars

“Vjetroelektrane” (eng. “Windmills”) with professor Krešimir

Trontl and “Iskorištavanje energije vjetra – Urban Wind” with

professor Slavko Krajcar.

He wrote his bachelor thesis “Stanje razvoja tehnologije

vjetrenih elektrana” (eng. “State of the Art of Windmills

Technologies”), also with his mentor, professor Slavko

Krajcar.

In 2012 he continued with his study on master program

concentrating his self on Windmills and other Renewable

Energy Sources. In the autumn 2013 he went to Teschnische

Universität Wien (Austria) to make new experiences and

knowledges.

During his stay in Vienna, he worked on a project (Master

Seminar) “Plan razvoja energetskog sektora u Republici

Hrvatskoj” with a team of other students from Zagreb, trying

to give new ideas of energy production and electrical

supplying in Croatia.

After the winter semester of academic year 2013/2014

spended in Vienna, he want to come back to Zagreb and do the

Master thesis which should be his finall work on the Faculty of

Electrical Engineering and Computing.

• His favourite hobbies are learning new languages, hanging out

with friends, watching movies, playing football and basketball,

bike driving, playing video games, fishing, etc.

Introduction

The goal of this presentation is to present

a ussage of robots in wind power plant such as

Wind Turbine Blade Inspection By Robots.

Characteristics of wind turbines

• If someone mention us a windmill (wind turbine), we will

probably think about the wind power plant with high tower and

long, mostly three, blades spinning over the rotor, just like its

shown in Picture 1.

• If we look inside the nacelle, we will notice couple of major

parts that are responsible for electricity production (Picture 2).

Characteristics of wind turbines

Picture 1. Wind turbine

Picture 2. Wind turbine from inside [http://inhabitat.com/ge-next-gen-offshore-wind-turbine-is-25-more-efficient/]

• Wind turbines require high investment costs, and one of the

most expensive parts of windmills are blades.

• Blades are specially designed to increase the efficiency of

wind turbines to make them competitive with fossil fuels.

• To increase the power of wind turbine, blades must grow in

length, but they also have to be as light as possible.

• Lighter weight means better performance, longer life, lower

manufacturing costs, and shortened manufacturing cycles, all

factors that enhance competitiveness in energy markets [5].

Picture 3. Typical structure of wind turbine blade

• It is important to inspect and maintaine windturbine blades to

keep them away from damaging, but also to keep safe other

parts of windmills that depense on blades (blades make stress

on mechanical and gear components).

• To avoide all costs that can be cause damaging of windturbine

blades it is necessary to take care about them.

• Blades are getting much larger, thus possibilities of damaging

them is also higher because of the higher tip speeds.

Picture 4. rotor diameters of wind turbines

[http://www.ucsusa.org/clean_energy/our-energy-choices/renewable-energy/how-wind-energy-works.html]

RIWEA (Robot for the Inspection of Wind Turbine Rotor

Blades) project

• The goal of the RIWEA project is to develop new technologies for

wind turbine blades inspections.

• Engineers want to be able to make thermography, ultrasonics and

high resolution pictures inspections.

• Robots are enclosing to a rotor blades what enables the detail inspect

of the blade.

• The systems developed in the project may also be utilized for other

fields of application.

• RIWEA robot can inspect bonded spar joints, leading edges,

and trailing edges by using non-destructive inspection system.

• RIWEA robot can be utilized in blade cleaning because the

robot can be fastened to the surface of the blade, regardless of

the figure, and can move the blades using wire [6].

Inspection of the windmill blades

• Technical inspection of windmill blades is not just a dangerous

job for blades but it also takes a lot of time.

• The first method of this kind of control insisted stoping the

rotation of blades and taking pictures of them from about 100

meters away.

• This process of blade inspection takes about four hours

• Engineers came to an idea to use robots (“climbing

maschines”) to make this process much more easier

Key elements of development [2]

1. Inspection system that inspects rotor blades from outside

2. Nondestructive inspection system such as active infrared

thermography and ultrasound for deeper structures such as the

bonded joints of the spar and leading and trailing edges

3. Visual surface inspection with high resolution cameras

4. Automated carrier systems that position and guide inspection

sensor systems along the rotor blade surfaces

5. Optimized power supply and safety systems for use at rotor

blades

6. Complete rotor blade condition log with precise mapping of

detected damage, specifying its particular position and extent

in a coordinate system matching the blade contour

Key elements of development [2]

International Climbing Maschines

• International Climbing Maschines is a company that produces

small robots designed to climb on different surfaces.

• These devices are portable and operated safely from the

ground so humans are not exposed to dangers

• These small maschines are capable to climb on different

surfaces such as tanks, ships, building structures, wind turbine

towers, dams, etc.

• The idea is that these robots climb on the wind turbine near

blades and make high-resolution pictures of them.

• They are using powerful magnets to cling tenaciously to the

metal surfaces as it spins around.

• These pictures are being sent to engineers who are reviewing

them searching for a possible damages.

Picture 5. Climbing robot

• The procedure of taking pictures of wind turbine blades takes

only few minutes.

• ICM rated these robots to pull up nearly 225 pounds, what is

enough to carry all necessary equipment.

• These robots are designed to work in different weather

conditions such as rain and high winds.

• They are capable to climb about 300 feet vertically.

• Additional possibility of these robots is usage of microwave

scanning to peer inside of the blade and search for the

damages before they come outside and cause problems.

Short video about climbing robot of International Climbing Maschines company

• To scan a blade from inside, engineers took high frequency to

increase the range and they were working on increasing it’s

speed too.

• HR-MP20 robot from Helical Robotics can carry up to 20

pounds of sensors, cameras, and other inspection gear, using

five powerful neodymium magnets to stick like a limpet to

steel towers and turbine blades that are at least seven feet in

diameter.

• The robot is controlled wirelessly from the ground, and with a

top speed of over 43 feet per minute, it can get to the end of

even the longest turbine blades in just a few minutes. What's

really impressive is that even out at the blade tip, the magnets

are powerful enough to keep the 42-pound robot from being

launched skyward [3].

• As the producers say, the price of this robot is about 20 000 $.

General Electric climbing robots

• General Electric (GE) is also one of the companies that

designe climbing robots that can be used for wind turbine

blades inspection.

• They are controled remotely and have a wireless camera.

General Electric climbing robots

Picture 6. Climbing robot of General Electric company

• The robots utilize a vacuum pump that removes the air

between the machine and the turbine, creating a vacuum seal

that keeps it solidly attached as it climbs [8].

• Short video below shows the GE robot climbing on vertically

surface as also it’s control system.

Short video about climbing robot of General Electric company

Technical datas of GE climbing robot [4]

Maintenance robot for wind power blade cleaning

• Robots haven’t find their use

only in blades inspections,

but also in cleaning of wind

turbine blades.

• To keep efficiency of the

wind turbines at the level, it

is important to clean blades.

Picture 7. Impurities on wind turbine

• “Dirt”on wind power blades includes flying plankton,

mosquitoes, oil, ice, dust, marine salt etc.

• Picture xx shows a bug on the blade (Magallon26 wind power

farm, May 2005.).

• This single bug caused partial loss of theoretical power

production (Picture xy.)

Maintenance robot for wind power blade cleaning

Picture 8. Loss of power production caused by bug

Maintenance robot for wind power blade cleaning

“Old” ways of cleaning

• Before new way of cleaning was discovered, people were

cleaning wind turbine blades by them slef as it’s shown in

pictures below. They were using water jet, ropes or ramps.

Picture 9a. “Old” ways of cleaning

wind turbine blades

“Old” ways of cleaning

Picture 9b. “Old” ways of cleaning wind turbine blades

Blade cleaning robot

• Blade cleaning robot is composed of side brush frame, leading

edge brush frame, camera, water tank, water jet, wire rope

holder, roller shock absorber, and brush (Picture 10.).

• The robot shown on a picture 10 has three brushes and two

cameras.

• It also has a tank with water (up to 350 l) and four water jets in

one brush module.

Blade cleaning robot

Picture 10. Blade cleaning robot

• Robot goes up by dropping 4 ropes from nacelle down the power

generator.

• It sprays water overral using water jet and brushes cleans the surface

of the blades.

• After cleaning, robot checks the surface of blades to see is there any

dirt left.

• This robot can move up to 0,1 m/s.

• The whole procedure takes 64 minutes per blade.

• This way of cleaning takes also 3 hours less than manual cleaning.

Picture 11. Blade cleaning robot on the mission

Part concept design

• Roller Shock Absorber offsets the vibration caused by

vertically movements of robot.

• Brush-Water Jet Module - three brush-water jet module, two

brushes and four water jet nozzle at every brush-water jet

module. Pressure of the water jet is up to 145 bar.

• Frame Moving of Brush - robot can cover the whole surface

of the blade because the robot moves vertically and brush-

water jet module moves horizontally.

Part concept design

• Camera – three cameras that show the condition of the blade

surface.

• Rope Holder – ensures the vertically movement of the robot.

Robot and whole equipment weight almost 1.5t.

Controller

• This type of robot require 19 motors:

• 6 brush rotating motors

• 3 vertical movement motors

• 3 water-jet turning

• Angle regulating motor and

• 4 hoist motion motors.

Controller

Picture 12. Control diagram

Controller

• Except the motors, this type of robot uses also 11 sensors.

• Most important sensors are razor sensor that measures the

distance between brush and the blade surface and distance

measuring sensor that measures the distance between brush-

water jet module and pillar frame.

• Control of the integration motor is done by 1 PLC controller

and uses 3 microcontrollers.

• PLC controller synchronizes 3 microcontrollers, and control

hoist of the nacelle to control vertical movement

Conclusion

• To keep wind turbine blades away of damaging, it is important

to inspect them and take care of them.

• To make this inspecting procedure simple, engineers are using

robots.

• Robots are climbing on the wind turbine a take pictures of

blades.

• These pictures are being send to engineers who analyses them

and look for possible damages.

Conclusion

• Robots can also inspect blades from inside using high-

frequency microwave radiation.

• Except blade inspection, robots can also been used to clean

blades so losess in electricity production could be avoided.

• Robots are presenting simple, cheap and safe way of

inspection, cleaning and maintaining wind turbines.

Literature

• [1] http://composite.about.com/od/applications/a/Evolution-

Of-Wind-Turbine-Blades.htm

• [2] http://www.iff.fraunhofer.de/en/business-units/robotic-

systems/riwea.html

• [3] http://www.dvice.com/2013-4-25/inspection-robot-

shimmies-out-spinning-wind-turbine-blades

• [4] http://www.gizmag.com/helical-robotics-wind-turbine-

inspection-robots/26921/

Literature

• [5] http://www.windpowerengineering.com/design/mechanica

l/blades/building-a-better-turbine-blade/

• [6] http://www.iaarc.org/publications/fulltext

/Maintenance_robot_for_wind_power_blade_cleaning.pdf

• [7] http://www.visatec.net/EN/01_Produkte/ROV/P

roduktblaetter/VT-610-ICMCL.php

• [8] http://www.theverge.com/2012/6/13/3083141/ge-wind-

turbine-robot

Literature

• [10] http://www.iff.fraunhofer.de/en/business-units/robotic-

systems/riwea.html

• [11] http://thinkgreendegrees.com/wind-turbine-blade-

inspection-by-robots-interviews-video-demo

• [12] http://www.intechopen.com/books/advances-in-wind-

power/wind-turbine-generator-technologies