Nof S.Y. Springer Handbook of Automation

Подождите немного. Документ загружается.

Space and Exploration Automation 69.2 Challenges of Space Automation 1245

mechanics and planetary atmospheric aerodynamics are

reasonably well understood and well behaved in space.

For surface rovers, the interactions between their mo-

bility systems and planet surfaces are complex and

sometimes further complicated by reduced-gravity ef-

fects. The result is nondeterministic behavior as the

system interacts with the world and increased uncer-

tainty in how the autonomous mobility system will

respond to operational commands. As such, mobility

and navigation problems for rovers are characterized

by high levels of difﬁculty and increased measurement

uncertainty. Common mobility and navigation sensors

often inadequately handle the tremendous variability

of surface features and properties of natural terrain.

Advanced sensing and perception techniques are of-

ten required for detection or measurement of signiﬁcant

wheel–terrain interactions such as slippage and sink-

age, and assessment or measurement of certain terrain

properties prior to engagement by the rover.

Robotic Manipulation

Mechanical manipulators or arms with multiple de-

grees of freedom are useful on a variety of robots

operating in space, on-orbit, and on planet surfaces.

They include ﬁxed-base manipulators on space shuttles,

space stations, landers, and rovers as well as manipu-

lation appendages on free-ﬂying robots. Robotic tasks

for this variety of systems may require ﬁne positioning

and dexterous manipulation of equipment or the en-

vironment. In order to accomplish manipulation tasks,

robots typically execute closed-loop feedback control

of arms/mechanisms, with the essential feedback pro-

vided by appropriate sensors. Further considerations

for achieving reliable manipulation include avoiding

collisions of the manipulator with the robot itself,

avoiding unintended contact with the environment, and

controlling forces during intended contactwith theenvi-

ronment. Oftentimes, it is also necessary to compensate

for errors associated with degradations and/or changes

in the manipulator hardware due to environmental fac-

tors such as spacecraft launch/landing vibrations and

material thermal expansion, which can affect the abil-

ity to accurately position a manipulator at a target of

interest. Sensing solutions that provide adequate cover-

age and resolution for both gross and ﬁne manipulation

are essential for missions requiring object handling and

transport, servicing/repair, assembly/disassembly, sam-

ple acquisition, and in situ acquisition of scientiﬁc

measurements. Additional information on robotic ma-

nipulation, and automation mobility and navigation can

be found in Chap.16.

Wheel Slip and Sinkage

Wheeled mobility systems are subject to undesirable

wheel–terrain interactions that cause wheels to slip on

rocks and soil. Frequent loss of traction due to wheel

slip during traverses from one place to another will

detract signiﬁcantly from the ability to maintain good

rover position estimates. Computer-vision-based mo-

tion and pose estimation, or visual odometry, is one

viable sensing solution. Current methods require sub-

stantial computation but may be feasible for future,

relatively fast-moving rovers if realized in hardware or

ﬁrmware with cameras that have dedicated embedded

processors.

It is highly desirable to have a capability to

sense wheel slippage so that corrective control actions

may be taken. Barring the capability to directly mea-

sure wheel slip, measurement of over-the-ground rover

speed would allow calculation of percentage slip using

an analytical relationship between slip, over-the-ground

speed, and wheel linear speed (as derived from encoder

readings or tachometers, for example). The problem

here is that true over-the-ground speed is also difﬁcult

to measure. If a rover attempts to drive forward while

all wheels are slipping, interpretation of wheel encoder

readings alone will indicate forward progress, but in

all probability the rover position will not have changed

signiﬁcantly. Some Doppler and millimeter-wave radar

solutions exist for measuring true vehicle speed, but

for rover use they must be low-power and low-mass

devices.

In soft soils, loss of traction due to excessive wheel

slippage can also lead to wheel sinkage and ultimately

vehicle entrapment. It is possible for wheels to sink to

soil depths sufﬁcient to prohibit rover progress over ter-

rain, thus trapping the vehicle at one location. This is

also possible on soils with insufﬁcient bearing strength

to support the rover (incidentally, a property to which

a look-ahead visual perception system may be insensi-

tive). Like wheel slip, it is desirable to have a capability

to sense excessive wheel sinkage so that corrective

controls may be executed before immobility results.

Sinkage measurements are also valuable for reducing

position estimation errors. A means to measure wheel

sinkage permits overall reductions in the effects of prop-

agating nonsystematic error during rover traverses on

varied terrain.

Terrain Properties

Capabilities for noncontact sensing of terrain properties

such as hardness or bearing strength are needed for de-

tecting nongeometric mobility hazards. Passive stereo

Part G 69.2

1246 Part G Infrastructure and Service Automation

vision or other ranging systems available on existing

rovers cannot detect pits ﬁlled with loose drift ma-

terial that may have insufﬁcient load-bearing strength

to support a rover. Such hazards are known to exist

on the Martian surface and need to be detected be-

fore a rover engages them, potentially meeting with

catastrophe. Downward-looking impulse radar can be

employed as a proximity sensor for this problem. Sim-

ilar millimeter-wave and microwave ranging sensors

are also useful for general obstacle detection and colli-

sion avoidance in environments subject to dust, blowing

sand, and other all-weather conditions. However, the

mass of available units may be prohibitive for some

planetary rover applications, and like the speed mea-

surement radars mentioned above, candidate radars for

terrain property sensing must be low-power and low-

mass devices.

It is also possible to infer nongeometric terrain

properties from sensor data. Some viable approaches

consider terrain appearance in camera images using im-

age texture differences for soil and rocks and other

approaches employ proprioceptive sensing (e.g., of vi-

brations) to resolve differences in feel of the terrain type

beneath rover wheels. The latter approach applies once

the terrain in question has been engaged and is there-

fore more useful for intelligent, reactive traction control

than for nongeometric mobility hazard avoidance. The

look-ahead, image texture-basedmethods, in addition to

their utility for appearance-based hazard detection, are

also useful for intelligent predictive traction control on

varied, but traversable, terrain surfaces.

69.2.2 On-Orbit and In-Space Robotics

Space robots have been used in low-Earth orbitfor tasks

of automatedservicing, inspection,and assembly. Satel-

lites require servicing for various reasons, each calling

for various forms of service action to be taken. Failure

of defective hardware may call for repair or replace-

ment of components or modules. Anticipated depletion

of fuel orpropellant maycall for refuelingin spaceif the

satellite’s mission is intended to continue. When a satel-

lite’s lifetime or mission expires it may be necessary to

remove it from orbit. On-orbit robotic servicing applies

to repair/replacement and refueling activities.

One of the automation challenges is the physi-

cal capture of free-ﬂoating satellites for retrieval and

subsequent servicing. Other challenges are related to

the general area of intelligent sensing and associated

data processing to ensure safe operations. Servicing

activities are representative of maintenance tasks that

Fig. 69.4 Illustration of robotic maintenance in space

are slated for on-orbit and in-space robots (Fig.69.4).

Other relevant tasks fall into the categories of assembly

of space structures and their post-assembly inspection

(Fig.69.5), as well as assistance to astronauts perform-

ing extravehicular activity (EVA).

In assembly operations, space robots would be used

to transport structural elements and mate elements that

are part of a larger space structure. Such tasks call for

rendezvous and docking, dexterous manipulation, and

ﬁne motion control for execution of detailed assem-

bly sequences. In-space assembly may be supported by

automated planning on space robot computers and on

off-board computers, or via human teleoperation. Some

space structures will have dedicated robotic systems as

part of their fully assembled design. An example is the

International Space Station, which (when fully assem-

bled) will have robotic systems including three main

manipulators, two small dexterous arms, and a mobile

base/transporter system.

Robots that perform important inspection tasks are

also needed on-orbit to examine space station and

Fig. 69.5 Illustration of robotic inspection in space

Part G 69.2

Space and Exploration Automation 69.2 Challenges of Space Automation 1247

spacecraft external hardware and outer surfaces for

damage or other problems. This may be done us-

ing robotic vision supported by mobility algorithms

designed to ensure required coverage of critical sur-

faces. Both free-ﬂying and legged space robots that

walk on space structure exteriors can be employed.

When astronauts must leave the safer conﬁnes of space

stations or spacecraft to perform EVA, space robots

will support their activities by performing tasks such

as retrieval and hand-off of tools for astronaut use,

monitoring of EVA operations, serving as additional

eyes or illumination sources to facilitate EVA in ar-

eas that are hard to access, or working cooperatively

as direct EVA participants. Research is underway to

address necessary challenges and technology develop-

ments applicable to a range of system entities from

Earth-based operations infrastructures to autonomous

robotic operations.

69.2.3 Subsurface Robotics

The solar system exploration agenda for the world’s

space agencies includes plans to access and sample the

subsurface environments of terrestrial planets, moons,

and small bodies such as comets and asteroids. This will

be yet another class of tasks for space robots. Near-term

focus is on the Moon, Mars, and Jupiter’s moon Europa,

Fig. 69.6 Mars Express spacecraft (courtesy of ESA)

the surface of which is ice-covered and the subsurface

of which is presumed to be an ocean of water possibly

harboring life. The subsurface of Mars is of interest be-

cause it is believed to be the only place on the planet

in which liquid water potentially exists and because

its sedimentary rock layers are believed to contain in-

formation about the geologic, hydrologic, and climatic

evolution of the planet as well as any signs of extinct

life (Fig.69.6). Subsurface water in its various forms on

Mars is alsoconsidered a critical resource for sustaining

robotic outposts and future human explorers. Water-ice

and structure of the lunar subsurface are of interest for

similar reasons. Along the same vein, the potential for

an ocean and life on Europa make its scientiﬁc interest

quite clear.

Today there is signiﬁcant focus on ways and means

to drill and bore into the surfaces of these bodies

using automation and robotics, and there are many

challenges to overcome. Most challenges being ad-

dressed presently relate to understanding the physics

and mechanical system requirements for drilling into

consolidated and unconsolidated materials comprised

of soil, rock, and/or ice to both shallow and deep

depths. Based on the ﬁndings of various such stud-

ies, associated requirements for intelligent control and

autonomy for robotic subsurface explorers are being

pondered as well by planetary scientists and engineers

alike (including aerospace, robotics, and Earth mining

engineers).

Robotics challenges presented by drilling mechan-

ics largely relate to control issues. After years of

experience drilling into the Earth, the best techniques

are still more of an art form than an engineering pro-

cedure. Humans are typically intimately involved in

determining and implementing the recovery procedures

when problems occur that inhibit drilling progress.

The art form mastered by human drill operators

translates, for space robotics, into a sensor-feedback-

intensive, knowledge-based, and reactive control task

that will need to be fully autonomous since similar

levels of human supervision will not be possible on

remote surface missions. Robust capabilities of auto-

mated monitoring and diagnosis with safe and reliable

autorecovery algorithms are necessary. At the very

least, human-equivalent performance by robotic sub-

surface devices may be needed for most tasks. As

with subsurface drilling on the Moon or Mars, loco-

motion through ice followed by subsea navigation will

require high levels of robotic autonomy moving be-

yond intelligent control and onto adaptive and learning

systems.

Part G 69.2

1248 Part G Infrastructure and Service Automation

69.2.4 Automation

Robotics typically refers to electromechanical systems

that embody some level of programmable intelligence

and that interact with or within physical environments.

Robots often operate in environments that are largely

unknown a priori and may be unstructured, thereby

requiring sensing and perception to compute or infer

intelligent actions. Automation often refers to auto-

mated devices or techniques that somehow improve

the performance or utility of a system or process.

Automated systems often operate in structured envi-

ronments, and their operation may or may not be

physical.

Automation for space systems is often applied to

reduce costs or enable new mission capabilities. To

date, some of the most advanced examples center on

the use of robotics as the form of automation, as

nonrobotic human spaceﬂight missions have relied to

a large extent on the capabilities of humans to achieve

mission success. Automation has also been used for

more common actions such as spacecraft antenna and

solar panel deployment enabled by automatic mecha-

nisms and devices. In the present and future, the use

of nonrobotic automation is on the rise and comes in

a variety of forms. Applications range from more per-

vasive software-based automation of data processing

functions to incorporation of robotic capabilities into

space suits intended to augment and amplify human ca-

pabilities in space. On some space missions, collection

of scientiﬁc data as well as its processing and analysis is

also handled by automation of science instrument sys-

tems. Some of the means of automating such functions

include computer vision, pattern recognition and classi-

ﬁcation techniques, and automated reasoning methods

of artiﬁcial intelligence.

Other activities and required infrastructure for

future space missions call for automation of the man-

ufacturing and construction variety. This is the case for

outposts on other planetary surfaces or in space where

humans would live and work for extended periods. As-

tronauts living and working in space on space stations

are typically surrounded by automated systems that run

life-support systems and perform functions formerly

performed by themselves or their human mission con-

trollers based on Earth. Example tasks for space station

automation solutions include initiation and monitor-

ing of experiments as well as detection and diagnosis

of system failures. On planetary surfaces, the cost-

effective approach to sustenance of astronauts includes

living off the land by using in situ resources; for ex-

ample, automated systems and production plants would

collect and process soil to extract water. Outpost au-

tomation would manufacture materials needed for life

support systems and would produce electricity and fu-

els to power equipment and facilities. Implementation

of automated systems along these lines has been con-

templated and extensively studied for many years [69.5]

and will be essential for long-duration human presence

in space.

69.3 Past and Present Space Robots and Applications

Over the past 30years, the exploration activities of

international space agencies have given automation

technology a proving ground for demonstrating its util-

ity and practicality in space. In the 1970s the former

USSR landed rovers on the Moon and teleoperated

them from Earth (Fig.69.7). Since the early 1980s nu-

merous NASA space shuttle ﬂights have consistently

involved teleoperation of the Canadarm. Space struc-

ture and scientiﬁc hardware deployments, assembly,

servicing, and repair have been some of the primary

uses of space automation on such missions in low-

Earth orbit. Such on-orbit uses of automation and

robotics have involved performance of tasks by as-

tronauts and robots teleoperated by astronauts, with

the most complex work performed by suited astro-

nauts during EVA, that is, on spacewalks outside of

the Space Shuttle Orbiter. Other robotic systems have

been used in this general class of application scenar-

ios for tasks associated with automation of science

experiments performed in space-based laboratories. In

the early 1990s, Germany’s ROTEX technology experi-

ment demonstrated the use of a mechanical manipulator

remotely controlled from Earth while on the NASA

Space Shuttle Orbiter as well as remotely controlled

by astronauts on the Space Shuttle Orbiter. Japan’s Ex-

perimental Test Satellite VII demonstrated automation

and robotic servicing technologies on-orbit in the late

1990s. NASA’s free-ﬂying Autonomous Extravehicular

Robotic Camera demonstrated a means to provide addi-

tional viewpoints or eyes for astronauts during EVAs.

Additional systems have been proposed and devel-

oped for space automation but never ﬂown for various

Part G 69.3

Space and Exploration Automation 69.3 Past and Present Space Robots and Applications 1249

Fig. 69.7 Russian lunar rover, Lunokhod 2

Fig. 69.8 Concept of the Mars Reconnaissance Orbiter

(courtesy of NASA/JPL)

reasons such as budget-related cancelations (e.g., the

Orbital Maneuvering Vehicle, the Flight Telerobotic

Servicer, and Ranger).

With the exception of the Moon missions of the

1970s the aforementioned automation and robotics ac-

tivities have been performed in low-Earth orbit. Space

automation has been applied in geostationary orbit

around the Earth as well. The many communications,

scientiﬁc, and military satellites in various Earth or-

bits today are great examples of space automation that

have directly affected quality of life on Earth. Robotic

tasks that can be automated in geostationary orbit in-

clude satellite servicing and deployment/assembly of

large space structures. However, since astronauts have,

to date, been constrained by technology to operations

Fig. 69.9a,b Mars exploration rovers Spirit (a) and Op-

portunity

(b) on Mars (special-effects images created using

photorealistic rover models and image mosaics acquired

during their missions)

in low-Earth orbit, robotic systems are more critical for

automated activities in geostationary orbit.

Moving further out into space beyond Earth,

robotics continues to play a critical role in expand-

ing our knowledge of the solar system. Space agencies

have employed numerous interplanetary robotic space-

craft, planetary probes, surface landers, and rovers that

have collected a substantial amount of data leading to

our current understanding of the solar system [69.6].

Destinations visited include nearly all of the planets as

well as asteroids and comets. The use of robotic tech-

nology in space has reached a level where, presently,

multiple robotic spacecraft are operating at any given

time throughout the solar system. At Mars alone, mul-

tiple robotic spacecraft including satellites, landers,

Part G 69.3

1250 Part G Infrastructure and Service Automation

and rovers are in operation today, performing scien-

tiﬁc missions aimed at understanding the past or present

habitability of that planet. The most recent orbiting

spacecraft that are still in operation at Mars were de-

livered by the USA and Europe and include Mars

Odyssey, Mars Reconnaissance Orbiter (Fig. 69.8), and

Mars Express (Fig.69.6). The most recent rovers that

are still in operation are NASA’s twin Mars explo-

ration rovers, Spirit and Opportunity (Fig.69.9), which

have been operating at different locations on the Mar-

tian surface since 2004. They have both collected data

leading scientists to conclude that liquid water once

ﬂowed on the surface of Mars at their respective landing

sites.

69.4 Future Directions and Capability Needs

Relatively few places on Earth’s moon have been ex-

plored by the rovers of the 1970s and by astronauts

during the series of NASA Apollo missions. As such,

relatively little is known about our Moon. Today, the

world’s space agencies and commercial sectors areturn-

ing a renewed focus on the Moon for further scientiﬁc

exploration, lunar resource-related commercial indus-

try, space tourism, and as a proving ground for enabling

future human exploration of Mars. Automation and

robotics are pervasive as tools to be used by human ex-

plorers to perform a variety of tasks involving rovers

and automated equipment for:

•

Surface exploration and transportation/deployment

of instruments and systems

•

Acquisition of scientiﬁc samples

•

Industrial mining for resources

•

Moonbase construction and assembly of facilities

•

Overall maintenance and repair of lunar infrastruc-

ture.

On the lunar surface, networked teams of robots will

work cooperatively to prepare sites for human habitats

at permanent lunar settlements. Robots will work with

automated machines and instruments as an integrated

system that constructs, services, monitors, and repairs

lunar outpost facilities. Such tasks may be shared with

astronauts or lunar settlers. Robotic systems will also

help to automate prospecting, mining, and processing

of lunar raw materials to help sustain human presence

by minimizing dependence on Earth support. Automa-

tion and robotic technologies to be developed toward

this end will be used in similar ways to facilitate even-

tual human exploration and settlement of locations on

Mars.

In space, free-ﬂying space robots will advance be-

yond the current state of the art to perform routine

servicing of space assets such as Earth satellites and

space stations (Fig.69.10). Free-ﬂying robots will work

cooperatively with astronauts to construct large scien-

tiﬁc and engineering space structures. Advances in the

following areas will be needed:

•

Mobility on space structures

•

Rendezvous and docking with spacecraft and struc-

tures

Fig. 69.10 MetOp-A satellite undergoing ﬁnal testing at

EADS Astrium’s facilities in Toulouse. MetOp-A was

launched on 19 October 2006 from the Baikonur Cosmod-

rome in Kazakhstan, on a Soyuz ST rocket with a Fregat

upper stage (courtesy of ESA)

Part G 69.4

Space and Exploration Automation 69.6 Further Reading 1251

•

Dexterousand force-controlledobject grasping,ma-

nipulation, and transport

•

Human–robot task planning and sequencing.

Planetary surface robotic systems will advance to the

next level of autonomous capability enabled by new

and improved sensing solutions. Advances are required

to reduce the computational complexity of computer

vision algorithms or to increase the computational

speed of radiation-hardened processors that they run

on. In addition to devices for sensing or detecting

wheel slip, wheel sinkage, and terrain properties for

planetary surface mobility, reliable devices and soft-

ware are needed that improve existing capabilities

for:

•

Sensing large-scale terrain discontinuities such as

cliffs, craters, and escarpments

•

Optical ranging in both full sun and deep shadow

•

Distributed sensing in multiple-rover applications.

69.5 Summary and Conclusion

An overview of space and exploration automation and

various associated challenges was presented with rele-

vanceto robotics applications foron-orbit, in-space, and

planetary domains. Representative space robots and ap-

plications were noted followed by indications of future

directions for space automation and technological ca-

pabilities that will be needed to successfully perform

future space missions.

During the past several decades space automation

has been relied upon, either solely or in concert with

resident human capability, to explore and reveal scien-

tiﬁc knowledge of space and the planets. The levels of

automation or degrees of autonomy have varied from

mission to mission and will necessarily increase in the

future as more ambitious space missions are pursued.

Autonomous mobility and manipulation are fun-

damental functions for space robotic tasks. Viable

solutions that support these functions within formidable

constraints of space computing hardware drive the

technological capabilities of space robots, and ulti-

mately, mission success. Application domains include

planetary surfaces, outposts/settlements, on-orbit/in-

space operations, and subsurface environments. The

challenges are associated with robotic tasks includ-

ing exploration, servicing, infrastructure building and

construction, inspection, and assembly in space and

planetary environments. A sense of the existing levels

of automation and the robotic intelligence or au-

tonomy employed to meet the various challenges is

provided.

In general, automation and robotics for space and

planetary missions require a variety of mobility and

manipulation capabilities supported by viable and ad-

equate means for sensing/perception and sophisticated

software algorithms that represent an appropriate level

of intelligence for the mission. Solutions must com-

ply with hard constraints on mass, power, mechanical

complexity, electrical characteristics, and computing.

In time, the greatest needs and remaining limitations

will be addressed and overcome by innovations and ad-

vances in sensing, perception, and autonomous control

engineering. To be sure, space robot intelligence and

autonomy will play a critical role in meeting the chal-

lenges to come.

69.6 Further Reading

•

A.M. Howard, E.W. Tunstel (Eds.): Intelligence for

Space Robotics (TSI, San Antonio 2006)

•

T. Huntsberger, A. Stroupe, B. Kennedy: System

of systems for space construction, Proc. IEEE

Int. Conf. Syst. Man Cybern., Waikoloa (2005)

pp.3173–3178

•

A. Stroupe, T. Huntsberger, B. Kennedy, H. Ag-

hazarian, E. Baumgartner, A. Ganino, M. Garrett,

A. Okon, M. Robinson, J. Townsend: Heteroge-

neous robotic systems for assembly and servicing,

Proc. 8th Int. Symp. Artif. Intell. Robot. Autom.

Space, Munich (2005)

•

P.S. Schenker (guest Ed.): Special issue on robots in

space, Autonom. Robots 14(2/3), 99–263 (2003)

•

B. Sommer: On-orbit servicing of satellites (OOS)

as a major application ﬁeld – the TECSAS mission,

Proc. 54th Int. Astronaut. Congr. Int. Astronaut.

Fed. (IAF), Bremen (2003)

Part G 69.6

1252 Part G Infrastructure and Service Automation

•

A. Popov: Mission planning on the International

Space Station program: concepts and systems, Proc.

IEEE Aerosp. Conf., Big Sky (2003)

•

N.J. Currie, B. Peacock: International Space Sta-

tion robotic systems operations – a human factors

perspective, 46th Annu. Meet. Hum. Factors Ergon.

Soc., Baltimore (2002)

•

E. Dupuis, R. Gillett, R. L’Archevêque, J. Rich-

mond: Ground control of International Space Sta-

tion robots, J. Mach. Intell. Robot. Control 3(3),

91–98 (2001)

•

P.J. Staritz, S. Skaff, C. Urmson, W. Whittaker:

Skyworker: a robot for assembly, inspection and

maintenance of large scale orbital facilities, Proc.

IEEE Int. Conf. Robot. Autom., Seoul (2001)

pp.4180–4185

•

D.A. Whelan, E.A. Adler, S.B. Wilson, G.M. Roes-

ler: DARPA Orbital Express program: effecting

a revolution in space-based systems, Proc. SPIE

Small Payloads in Space, Vol.4136 (2000) pp.48–

•

A. Ellery: An Introduction to Space Robotics

(Springer, Heidelberg 2000)

•

M. Oda, K. Kibe, F. Yamagata: ETS-VII – space

robot in-orbit experiment satellite, Proc. IEEE Int.

Conf. Robot. Autom., Minneapolis (1996) pp. 739–

744

•

S.B. Skaar (Ed.): Teleoperation and Robotics in

Space (AIAA, Reston 1994)

•

A.K. Bejczy, S.T. Venkataraman, D. Akin (Eds.):

Special issue on space robotics, IEEE Trans. Robot.

Autom. 9(5), 524–704 (1993)

•

A.A. Desrochers (Ed.): Intelligent Robotic Systems

for Space Exploration (Kluwer, Boston 1992)

•

T. Sheridan: Telerobotics, Automation, and Human

Supervisory Control (MIT, Cambridge 1992)

References

69.1 A.Ellery:Spacerobotics,Part1,Int.J.Adv.Robot.

Syst. 1(2), 118–121 (2004)

69.2 A.Ellery:Spacerobotics,Part2,Int.J.Adv.Robot.

Syst. 1(3), 213–216 (2004)

69.3 A. Ellery: Space robotics, Part 3, Int. J. Adv. Robot.

Syst. 1(4), 303–307 (2004)

69.4 P. Putz: Space robotics, Rep. Prog. Phys. 65,421–

463 (2002)

69.5 R.A.FreitasJr.,T.J.Healy,J.E.Long:Ad-

vanced automation for space missions, Proc.

7th Int. Joint Conf. Artif. Intell., Vancouver 1981

(William Kaufmann, New York 1981) pp. 803–

808

69.6 M. van Pelt: Space Invaders: How Robotic Space-

craft Explore the Solar System (Springer, New York

2006)

Part G 69

1253

Cleaning Auto

70. Cleaning Automation

Norbert Elkmann, Justus Hortig, Markus Fritzsche

The potential applications of automation for clean-

ing are many and diverse. All over the world,

research organizations and companies are devel-

oping automatic cleaning systems [70.1]. Products

such as automatic ﬂoor cleaning robots and ﬂoor

vacuum cleaners available for household use are

sold ten thousand times over every year at prices

below US

$300 (Fig. 70.1). While versatile, high-

performance systems exist for other applications

such as professional ﬂoor cleaning, airplane wash-

ing, ship cleaning, and facade cleaning, they are

by no means as widespread as household systems.

Automatic cleaning systems are frequently

extremely complex robot systems that operate

autonomously in unstructured environments or

outdoor areas. Cleaning automation not only

incorporates cleaning engineering but also

a variety of other technical disciplines, e.g.,

autonomous power supply, sensor systems, envi-

ronment modeling, and path planning in dynamic

environments.

70.1 Background

and Cleaning Automation Theory ...........1254

70.1.1 Floor Cleaning Robots ...................1255

70.1.2 Facade, Pool, Ventilation Duct,

and Sewer Line Cleaning Robots.....1255

70.2 Examples of Application ........................1256

70.2.1 Floor Cleaning Systems..................1256

70.2.2 Roofs and Facades........................1258

70.2.3 Ducts and Sewer Lines ..................1261

70.2.4 Swimming Pools ..........................1261

70.3 Emerging Trends ..................................1263

References ..................................................1263

Some examples of automatic cleaning systems for

ﬂoors, facades, swimming pools, ventilation ducts,

and sewer lines serve to highlight the current

potential of cleaning automation and provide

a glimpse of future developments.

Humans typically experience cleaning as monotonous

work, which by its very nature is performed in dirty en-

vironments. Moreover, cleaning can sometimes even be

hazardous to health or life endangering, depending on

the area or object and the type of cleaning involved.

Nonetheless, such areas may require regular cleaning.

Cleaning therefore ideally meets the premises for

applying robots or remote-controlled systems and is

inherently a typical service robot application. Unsur-

prisingly, developments over the last 20years have

been aimed at automating cleaning systems. The range

of systems available varies widely. Apart from ﬂoor

cleaning systems, other systems also clean facades,

swimming pools, ventilation ducts, and sewer lines.

Some of them are extremely complex.

Fig. 70.1 iRobot Roomba

Part G 70

1254 Part G Infrastructure and Service Automation

Mass markets for cleaning robot applications have

already developed in some sectors. Vacuuming robots

for household use represent one of the most widely

sold robot systems worldwide. Their sheer numbers and

low purchase prices of less than US $300 account for

their great commercial success in the household sec-

tor [70.2,3]. Residential users have far lower demands

on cleaning quality and, above all, cleaning speed

than professional users. In the 1990s, several manu-

factures of cleaning machines throughout the world

developed autonomous cleaning robots for professional

ﬂoor cleaning. Nonetheless, these systems have not

yet become established on the market for a variety of

reasons. Less ﬂexibility than humans, high acquisition

costs, low availability, and complexity of operation of-

ten militate against the use of these systems.

Cleaning robots [70.1] and ﬂoor cleaning systems

(Fig.70.1) in particular share many commonalities with

other service robots, e.g., for transport or monitoring

tasks. Particular points of intersection are sensor sys-

tems for obstacle detection and environment modeling,

powersupply, path planning and execution,and human–

machine interfaces. Thus, cleaning robots constitute

a preliminary stage to complex household applications

for service robots or applications with direct human–

robot interaction.

Cleaning robots forfacades, pipes, ventilationducts,

and sewer lines are however not mass-produced items.

These systems are specially optimized for the require-

ments and geometry of the surface or object being

cleaned and are used exclusively in professional envi-

ronments rather than in the residential sector.

A robot’s features or technical innovations are less

crucial to its acceptance than its cleaning efﬁciency and

cost effectiveness. A system’s ﬂexibility and ease of

operation are other important criteria for acceptance.

70.1 Background and Cleaning Automation Theory

Cleaning robots incorporate a multitude of basic de-

velopments and theories of robotics, e.g., mobility

and navigation, communication, sensors and sensor

networks, robotics and intelligent machines, and tele-

operation, which are treated in conjunction with mobile

robots in Chaps. 9 and 11 of this Handbook.

Cleaning robots have different levels of automation,

ranging from remote-controlled systems with inexpen-

sive, individual sensors to autonomous systems with

complex, multiple sensors for environment modeling

and navigation.

All types of cleaning systems share certain technical

subsystems:

•

Motion platform for the system and cleaning unit

•

Control and operating system

•

Sensor system for environment modeling (in auto-

matic systems) and obstacle detection

•

Power supply

•

Communications system

•

Cleaning unit and, where applicable, suction and

material processing units

•

Various safety devices (collision avoidance systems

for ﬂoor cleaning systems, securing or recovery

ropes for facade, pipe, duct, sewer, and pool clean-

ing systems)

All automated cleaning systems draw on established

cleaning methods and technologies. An automated

cleaning system however cannot inspect its cleaning

quality as easily as a human can. At present, mobile

systems that clean areas with varying optical conditions

and textures cannot measure the level of dirtiness re-

liably. They can, however, check the quantity of dirt

picked up over a unit of time.

Cleaning robots from the different ﬁelds of applica-

tion differ widelyin terms ofrequirements andtechnical

challenges. Basically, two categories can be distin-

guished and the underlying requirements subsumed in

these two groups:

•

Floor cleaning robots: Such cleaning systems re-

lieve humans of monotonous work such as mopping

and vacuuming. For their use to be cost effec-

tive, these systems must function autonomously and

without an operator. Easy operability, high-quality

cleaning, and ﬂexible use are basic requirements

these systems have to meet.

•

Facade, pool, ventilation duct, and sewer lineclean-

ing robots:Such cleaning systems are utilized where

humans are unable to access an area in need of

cleaning or are only able to access it with ex-

treme difﬁculty. These systems can be engineered

to be remote controlled or fully autonomous. Usu-

ally, they are customized for a speciﬁc application

scenario. Nevertheless, easy operability and high-

quality cleaning are basic requirements. They must

Part G 70.1