Hydraulically Actuated Hexapod Robots: Design, Implementation and Control

285 Pages·2014·15.12 MB·English

by  Kenzo Nonami

Intelligent Systems, Control and Automation:
Science and Engineering
Kenzo Nonami
Ranjit Kumar Barai
Addie Irawan
Mohd Razali Daud
Hydraulically
Actuated Hexapod
Robots
Design, Implementation and Control
Intelligent Systems, Control and Automation:
Science and Engineering
For furthervolumes:
http://www.springer.com/series/6259

Kenzo Nonami (cid:129) Ranjit Kumar Barai
Addie Irawan (cid:129) Mohd Razali Daud
Hydraulically Actuated
Hexapod Robots
Design, Implementation and Control
KenzoNonami RanjitKumarBarai
DepartmentofMechanicalEngineering DepartmentofElectricalEngineering
DivisionofArtificialSystemsScience JadavpurUniversity
GraduateSchoolofEngineering Kolkata,India
ChibaUniversity
Chiba,Japan
AddieIrawan MohdRazaliDaud
FacultyofElectricalandElectronics FacultyofElectricalandElectronics
Engineering Engineering
RoboticsandUnmannedSystems RoboticsandUnmannedSystems
(RUS)group (RUS)group
UniversitiMalaysiaPahang UniversitiMalaysiaPahang
Pahang,Malaysia Pahang,Malaysia
ISSN2213-8986 ISSN2213-8994(electronic)
ISBN978-4-431-54348-0 ISBN978-4-431-54349-7(eBook)
DOI10.1007/978-4-431-54349-7
SpringerTokyoHeidelbergNewYorkDordrechtLondon
LibraryofCongressControlNumber:2013949168
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Preface
Roboticstechnologycoversverywidearea.Fullyautonomousrobotsinparticular
are associated with three functions, namely, manipulation, locomotion, and com-
munication.Locomotionrobotsmaybeclassifiedbytheenvironmentinwhichthey
travel: (1) Land or home robots are most commonly wheeled, unmanned ground
vehicles (UGVs) but also include legged robots with two or more legs, like
humanoidsorresemblinganimalsorinsects.(2)Aerialrobotsareusuallyreferred
to as unmanned aerial vehicles (UAVs). (3) Underwater robots are usually called
autonomousunderwatervehicles(AUVs).WheeledandtrackedUGVs,UAVs,and
AUVs are already in use for real applications. The exceptions are legged robots.
Unfortunately, legged robotsbased on the use ofanimal-like andhuman-like legs
are still in the research phase even though many research outcomes have been
achieved.Themainreasonfortheirremainingintheresearchstagemaybethatthe
locomotion speed and the energy efficiency of legged robots are still very low
comparedwiththoseofwheeled robots.However,wheeledvehiclesareunableto
moveonrough,off-roadorunmodifiednaturalterrain andneed pavedsurfacesin
ordertooperatesmoothly.
According to the United States Army, approximately half of the Earth’s land
surface is inaccessible to either wheeled or tracked vehicles. Legged animals and
humansarecapableofleggedlocomotionandasaresulttheycanaccessanypartof
theEarth’slandsurfacewithoutgreatdifficulty.Theseleggedcreaturescanwalkon
rough or irregular terrain by establishing foot contact with the ground at selected
pointsaccordingtotheterrainconditionsandbyvaryingtheirlegconfigurationsin
order to adapt themselves to irregularities in terrain. Thus, legs are inherently
adequate systems for locomotion on rough and irregular terrain. This fact was a
motivationforthedevelopmentofartificialleggedlocomotionsystems.
Amongthevarioustypesofleggedrobots,hexapodwalkingrobotsofferagood
static stability margin and locomotion speed, and at the same time they are fault-
tolerant. Therefore, hexapod walking robots have emerged as a popular robotic
system for various critical and hazardous field applications. The origin of our
research motivation was to build a human-like de-mining robot using hexapod
robots. We need a fast, safe, and robust technique for de-mining operations, and
v
vi Preface
walkingrobotscanbeconsideredaneffectiveandefficientmeansforthatpurpose.
Hydraulically actuated hexapod walking robots can be used for the detection and
removaloflandmineswhileprovidingsafetyandsecurityfortheoperatingperson-
nel. Hydraulically actuated hexapod robots are mechanically robust, have a high
level of static stability margin, and are suitable for operation in rough terrain.
Therefore, their deployment for de-mining tasks is advantageous from the point
of view of their safe locomotion capability in a mine field and their capability to
carrylargepayloadsofthetoolsrequiredforde-miningmissions.Nonamigroupat
theRoboticsandControlSystemLaboratory(NonamiLaboratory),ChibaUniver-
sity,Japan,hasdevelopedandsuccessfullytestedthehydraulicallyactuatedhexa-
pod robots COMET-III and COMET-IV for achieving robot-assisted de-mining.
Thisbookdescribestheessentialdesign,implementation,andcontrolofhydrauli-
callyactuatedhexapodrobots.
Chapter1coversvarioustheoreticalandpracticalaspectsofleggedlocomotion
and also introduces many popular and successfully implemented legged robots
around the world. Chapter 2 presents a condensed perspective of the historical
evolutionofwalkingrobots.Chapter3describesthegroup’sattempttofundamen-
tallyreviewthebasicspecificationsofarobot,suchasthemechanism,gait,drive
system, and control system, and to approach the optimization-based design of
COMET-IV—thehexapoddangerous-operationsrobot.Chapter4dealswithkine-
matics and path planning of COMET-IV. In particular, the developed kinematics
anddynamicsareexploitedtobeusedforend-effecterforceonfootdetectionand
overall COMET-IV stability for force-attitude control purposes. In COMET-IV
research,thetotalforceonthefootiscalculatedforcenter-of-mass(CoM)identifi-
cationasaninputforrobotattitudeduringwalkingsessions.Chapter5startswitha
generaldescriptionofposition-control-basedlocomotioncontrolofwalkingrobots.
Then the various nonlinearities of the hydraulic actuation system are briefly
described.Finally,twosliding-mode-basedlocomotioncontroltechniquesandthe
robust adaptive fuzzy-control-based locomotion control technique of COMET-III
intheposition-control-basedframeworkarepresentedwithreal-timeexperimental
results.InChap.6,itisshownthat,withthecapabilityofactivesuspension(legs),
thestrongroleoflegged/walkingrobotdesignmakesitpossibletopassthroughany
uneven terrain as long as the obstacles are lower than the robot’s maximum or
minimumoverallbodyheight,ifcomparetothewheeltyperobot.Therefore,force
orimpedancecontrolisneededtomakeadynamicresponseoneachleginorderto
identify the different level of the terrain or any sudden changes in the terrain.
Moreover, this control is crucial in hidden areas that could not be identified by a
vision system via pre-scanning and localization. Chapter 7 proposes several
algorithms such as impedance control implementation for the hexapod robot
COMET-IV. Also, in the case of heavy-weight and large-scale-structured robots,
inclinometers from attitude angles must be designed to control the long-term
attitudes of the body without any vibration caused by changes in support of
the legs. This shaking is considered a natural scenario since the robot is using a
hydraulicsystemandanautomotiveengine.Chapter8dealswithcasesofextreme
environments, where it is difficult to achieve full autonomy. Therefore, a
Preface vii
teleoperation-based system has been designed on the COMET-IV for extreme
environments. The teleoperation assistant system is designed to understand the
ambient environment and the movement conditions of the robot. These include
leggedrobotchangesthataffecttheheightofthebodyandtherobot’sattitude.In
thischapter,weappliedanomni-directionalvisionsensorand3Drobotanimation.
The online 3D virtual reality technique is proposed for achieving synchronous
control between virtual 3D animation and the physical COMET-IV in a real
environment. Chapter 9 proposes several methods for crossing an obstacle and
descendingandascendingacliffbasedonLRF3Dpointclouddata.Experimental
results show that the proposed methods are useful for performing assigned tasks.
Chapter10describeschallengesandnewfrontiers.
Hydraulically actuated hexapod robots form a very useful class of walking
robots in the context of service robotics, field robotics, search and rescue, and
high-risk operations. They can also be utilized as a test bed for designing and
validatingvariousgaitsandwalkingbehaviors.Manypotentialapplicationsmaybe
possible with the advent of various technologies associated with the design and
manufacturingofsuchrobots.
I would like to express my sincere gratitude to Dr. Y. Ooroku, Mr. H. Sugai,
Mr. M. Oku, Mr. H. Yang, Mr. G. Piao, Mr. K. Adachi, Mr. Y. Harada,
Mr. K. Futagami, Mr. G. Lin, Mr. D. H. Tran, Mr. Y. Akutsu, Mr. R. Li,
Mr. S. Imamura, Mr. A. Haneda, Mr. R. Namiki, Mr. Y. Tsuchida,
Mr. Y. Tondok, and Mr. K. Zhao, who contributed so much to the work on
COMET-IV.Thisbookwouldnothavebeenpossiblewithouttheirdevotedefforts.
I am also very grateful to many of my laboratory students who contributed to
COMET-I, COMET-II, and COMET-III projects. Finally, we would like to thank
Ms.Y.SuminoandMs.T.SatoatSpringerfortheirsupportandencouragementin
undertakingthispublication.
Chiba,Japan KenzoNonami
Kolkata,India RanjitKumarBarai
Pahang,Malaysia AddieIrawan
Pahang,Malaysia MohdRazaliDaud

Contents
1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Walking“Machines”orWalking“Robots”?. .. . . . .. . . .. . . .. 4
1.3 “BiologicallyInspired”DesignsandDevelopment
ofWalkingRobots. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.4 ClassificationofWalkingRobots. .. . . . . . . . . .. . . . . . . . . . .. 6
1.5 HexapodWalkingRobots:APopularWalkingMachine
forFieldRoboticsApplications. . . . . . . . . . . . . . . . . . . . . . . . . 8
1.6 WalkingRobotTerminology. . . . . . . . . . . . . . . . . . . . . . . . . . . 15
1.7 ChallengesofNavigationandLocomotionControl
ofHexapodWalkingRobotfortheField
RoboticsApplications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2 HistoricalandModernPerspectiveofWalkingRobots. . . . . . . . . . 19
2.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.2 HistoricalPerspectiveofWalkingRobots. . . . . . . . . . . . . . . . . 21
2.2.1 EmergenceofArtificialLeggedLocomotion
fromAncientCivilizations:Imagination,Ideas,
andImplementations. . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.2.2 EvolutionofModernWalkingRobots. . . . . . . . . . . . . . . 27
2.3 ModernandFuturePerspectiveofWalking
RobotResearch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
3 DesignandOptimizationofHydraulicallyActuated
HexapodRobotCOMET-IV. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3.1 SystemConstruction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
3.1.1 ConceptualDesign. .. . . . . .. . . . .. . . . .. . . . .. . . . .. 42
3.1.2 OverallMechanicalSystemDesign. . . . . . . . . . . . . . . . 46
ix