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HUMANOID ROBOTICS PAST, PRESENT STATE, FUTURE
Dharmasastha N, Rajeshwar V,
[email protected] IFET College of Engineering, Gangarampalyam, Gangarampalyam, Villupuram.
Abstract: Humans are the most advance advanced d creatu creatures res of the nature nature.. I believe that humanoid robots will be the most most advance advanced d creatu creatures res of humans humans.. Among the man-made creatures such as automobile, automobile, hand-phones hand-phones and multimedi multimediaa devices, robots of future will hopefully be the most ideal assistants to human beings. beings. Robots can live up to this expectation expectation because future future intelligent intelligent and autonomous autonomous robots could free humans humans from, from, or ease ease them them up of, repeatedly repeatedly undertaking undertaking physically physically and ment mental ally ly chal challe leng ngin ing g rout routin ines es.. For instance, instance, Robot Doctor Doctor could provide medical advices, pre-diagnost pre-diagnostic, ic, and even assist in surgical operation; Robot Nurse could assist assist patients patients in hospital hospital or at home home;; Robo Robott Sold Soldie ierr coul could d participate participate in military military intervention, intervention, and even fight terrorism; Robot Tutor could help our students to have a better better learning learning experience; experience; Robot Guard could could make make our soci societ ety y much much safer safer;; Robot Maid could keep our house clean and secure, and even help look after eld elderly peo people at home ome; Robot Rescuer could be deployed deployed to places where human lives are in danger. The list of potential applications with intelligent and autonomous robots is growing. Keywords: Humanoid robot, ZMP, semi- inverse method,active exoskeleton, activ activee suit suit,, forc forcee-pos posit itio ion n contr control, ol, artificial artificial intelligent,dy intelligent,dynamic namic control, control, decentralized control. INTRODUCTION
Rapid development of humanoid robots
brings about new shifts of the boundaries of Robotics Robotics as a scient scientifi ificc and tech techno nolo logi gical cal disc discip ipli line ne.. New New technol nologie gies of compon ponents, se sensors, microc microcomput omputers ers,, as well well as new materials, materials, have recently removed the obstacles to real-time integrated control of some some very very comple complex x dynami dynamicc systems systems such such as humano humanoid id robots, robots, which already today possess about fifty degrees of freedom and are updated in microsecond microsecondss of controller controller signals. In view of the above statements, the work for the first time raises The essential question on the justifiability of increasing the number of degrees of freedom of humanoid robots, having in mind that for the overall skeletal activity man has at its disposal roughly about 650 muscles of human body body which which could could be approxim approximatel ately y expressed by more than three hundreds equivalent equivalent degrees of freedom, freedom, i.e. the same number of biological actuators. In relation to this, the work raises also some new fundamental fundamental questions concerning the necessary anthropomorphism of humanoid robots, how to define the the degr degree ee of anthr anthropo opomo morp rphi hism sm,, and and finally, finally, how to achieve achieve the highest degree of anthropomorph anthropomorphism ism with a lowest number of degrees of freedom. On the example of a humanoid robot, concrete measures are proposed how to achieve achieve the desir desired ed Degree Degree of anthropomorphism of humanoids.
The above-menti above-mentioned oned obstacles obstacles being taken down, along with the humanoid humanoid robot bots playing main ainly the role of communicators and entertainers, there have appeared humanoids of quite different different aspirations aspirations in the domain of manipulation- locomotion activities of humans humans (case (case of sport sports-ma s-man n on a trampoline, man on the mobile dynamic platform, platform, running, balanced balanced motion motion on the foot - a karate kick, playing tennis, soccer or volleyball, gymnastics on the floor or by using some gymnastic gymnastic apparatus, apparatus, skiing skiing - balanced balanced – motion motion with sliding, etc.). The work is also promoting some new ideas concerning the already visible trends of expanding activities of humanoid robotics to cover the above new tasks. tasks. The novelty novelty is relate related d to generali generalize ze approach approach to the modeling of humanoid motion. Instead of a usual inductive approach that starts from the analysis of different real motion situ situat atio ions ns and and trie triess to make make a generalization, the work proposes a new deductive approach. My opinion is that there are still limited results on human-like motion, while the field of human- like communication has produced several viable alternatives. On the other hand, human-like intelligence is the main obstacle to be overcome because of its com complex plexit ity y and and mult ultidim dimensi ension onal alit ity y; it is also responsible responsible for coordination coordination of the entire entire person personal al robot robot behavior. behavior. And finally, finally, bearing in mind the current progress in the constantly co nstantly developing field of humanoid robotics, whose end products products will certainly certainly acqu acquir iree with with time time more more and and more more huma humann-li like ke char charac acte teri rist stic ics, s, we can can ask an ungrateful question: Can we imagine that it may not be long before biologist biologistss construct construct a ‘perfect ‘perfect personal personal robot’ robot’ a real real human human cloned cloned and genetically engineered with all attributes of a perfect servant (a worker, a soldier) despite of all the ethical, legal and sociological problems that may arise? In my opinion, it will be possible possible to get closer to human characteristics only if such progress is made in technological
innovations (artificial muscles, adaptive materials, self- learning) that will allow the performances performances of artificia artificiall systems systems bec becom omee simi simila larr to thos thosee of man. man. intelligence is the main obstacle to be overcome because of its complexity and and mult multid idim imens ensio iona nalit lity; y; it it is also also responsibl responsiblee for coordination coordination of the entire personal robot behavior. And finally, bearing in mind the current progress in the constantly developing field of humanoid robotics, whose end products will will certai certainly nly acquir acquiree with with time time more more and more human-like human-like characteri characteristics stics,, we can ask an ungrateful question: Can we imagine that it may not be long long before before biologists biologists construct construct a ‘perfect ‘perfect personal robot’ a real human cloned and genetically engineered with all attributes of a perfect servant (a worker, a soldier) despite of all the ethical, ethical, legal and sociological problems that may arise? In my opinion, it will be possible possible to get closer to human characteristics only if such progress progress is made in technological technological innovations (artificial muscles, adaptive materials, self- learning) that will allow the perform performance ancess of artifi artificia ciall syste systems ms become similar to those of o f man
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BEGINNINGS OF THE ROBOTICS
The word robot appeared first in 1920, in the play ‘Rossum's ‘Rossum's Universal Robots’, written by the Czech writer Karel Capek. The play depicts perfect workers –robots, workers –robots, endow endowed ed with with emot emotio ions ns enab enabli ling ng to increase increase their productivit productivity. y. Concepts Concepts akin to today's robot can be found as long ago as 450 B.C. when the Greek mathem hematician Taren rentum postula ulated a mechanical bird he called ‘The Pigeon’ which was pro-pilled by steam. Al-Jazari (1136-1206) The first known functioning robot was created in 1738 by Jacques de Vaucanson. Vaucanson. In 1893, George Moor created a steam man. He was powered by a 0.5 hp gas fired boiler and reached a speed of 9 mph (14 kph). Westinghouse made a humanoid humanoid robot known as Electro. It was exhibited at the 1939 and 1940 World’s Fairs, whereas the first first electronic autonomous robots were created by Grey Walter at Bristol University, University, England, England, in 1948. If we would like to relate the beginnings of robotics to the appearance of industrial robots we should point out that George Devol Devol patent patented ed in the United United State Statess a first first robotic robotic device in 1954, whereas whereas Joseph Engelberger, also an American, constructed first industrial robot in 1961. Therefore, the year 1961 was essential for the beginning of industrial robotics. Since 1970 we have witnessed witnessed an intens intensive ive developm development ent of indust industri rial al robotics. robotics. Robots have replaced replaced men primaril primarily y in those jobs that were dangerous dangerous to humans and harmful harmful to their health, and also introduced higher regularity and accuracy in machining of parts, assembly of blocks and systems, as well yielded increased productivity. For example, example, in the last 15-20 years car manufacturing has been automated and fully robotized, starting from the initial stage of forging, through engine manufa manufactu cture, re, to assemb assembly ly of parts parts into into the final product – car, including including its painting. painting. carving and deboning, microrobot robotss for for insp inspec ecti tion on of inte intest stin inal al tract, tract, and even carving and deboning, deboning,
micro-robot micro-robotss for inspection inspection of intestinal intestinal tract. A Turk Turkis ish h constructed
inve invent ntor or
desi design gned ed
and and
automatic machines such as water cloc clocks ks,, kitc kitche hen n appl applian iance cess and and musi musica call automats powered by water. One of the first first recorded designs of a humanoid humanoid robot was made by Leonardo da Vinci in around 1495. Da Vinci's Vinci's notebooks, rediscovere rediscovered d in the 1950s, contain detailed drawings of a mechanical knight able to sit up, wave its arms and move its head and jaw. These are, for example, example, robots for antiterroristic actions, for deactivating explos explosive ive devices devices,, locati locating ng and destroying mines, mending damages in the electric power network without switching switching off, picking picking fruits, fruits, concrete concrete works, digging underground chanals and their main mainte tenan nance ce,, clea cleani ning ng tall tall buildings, replacement of damaged parts of tanks and pipelines, sheep shea sheari ring ng,, robot robotss-but butch cher erss for for meat meat carving and deboning, micro-robots for inspection inspection of intestinal intestinal tract, tract, and even for examination of the quality of blood vessels, etc. There have been more frequent.
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HUMANOID ROBOTICS
The beginning of the development of humanoid robotics coincided with the beginning beginning of the development of active exoskeletons, first in the world, in 1969 in the Mihajlo Mihajlo Pupin Institute Institute under the the guidan ce of Prof. Vukobr Vukobratovi atovic. c. It sho uld be noted that legged locomotion systems were developed first. Also, the first theory of these systems has been developed in the same institute, in the frame frame of active active exoskeletons. exoskeletons. Hence, it can be said that active exoskeletons were the pre prede dece cess ssor orss of cont contem empo pora rary ry high high- performance performance humanoid humanoid robots. robots. Recently, Recently, there has been ev ident revived interest interest in active exoskeletons, first of all of military dedica dedicatio tion. n. The presen present-d t-day ay active active exoskeletons are developed as the systems for enhancing human natural skeletal system.
First Version of the Powered Leg at Mihailo Pupin Institute (1971)
attempts in which robots performed delicate surgical operations, either on the spot or at a distance.
Active exoskeleto n with electromechanical drives, electronically programmed, built and tested in 1974. Served mainly to evaluate and develop electromechanical drives for active orthotic devices, as the ‘Active suit’ or active arm orthosis. This is the first example known in the world of active exoskeleton that used electric motors as actuators. As such, it can be considered as the predecessor of contemporary humanoid robots driven by electric motors.
ZERO-MOMENT POINT CONCEPT AND SEMI-INVERSE METHOD
In parallel with the states feedback includ luding lo loads feedback at powered joi joint ntss of legg legged ed loco locomo moti tion on robot robotss and and particularly of bipe biped d mech mechan anis isms ms,, it is essential for dynamic stability of the overall system to control ground reaction forces arising at the contacts of the feet and the ground. For instance, with the biped robot in the single support phase, shown below in the figu figure re,, it is is poss possib ible le to to repl replac acee all all elementary vertical forces by their resultant. Let the point O represent the point at which the sum of moments is equal zero, so R that this this point where only force force is acting is called Zero-Moment Zero-Moment Point (ZMP). (ZMP). The equations of dynamic equilibrium of the biped mechanism can be derived for ZMP, so that the introducti introduction on of the ZMP Z MP notion n otion made made it possi possible ble solve olve this his ver very speci pecifi ficc problem of applied mechanics. Namely, for any other point except for ZMP, equations equations of dynamic equilibrium equilibrium would contain unknown dynamic reaction forces, making making thus the problem of dynamics dynamics modeling in the class of legged, particularly of biped biped locomo locomotio tion n robots, robots, unsolv unsolvabl able. e. However, if we integrate the equations written for the ZMP, then it becomes possible to calculate the reaction forces, as they depend on all internal coordinates,
velocities, velocities, and accelerati accelerations ons of the overall overall mechanism. A next decisive step in modeling and control control of legged, particularly particularly biped locomotion robots was the introduction of the
semi-
inverse method.
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WHAT IS THE ESSENCE ESSENCE OF THE SEMI-INVERSE METHOD?
The conditions of dynamic equilibrium with respect to the coordinate frame attached to the Zero Moment Point Point give three relati relations ons betwee between n the genera generaliz lized ed coord coordin inat ates es and and their derivatives. derivatives. As the whole syst system em has has n degr degrees ees of freedom (n>3), Thus, when applied to the problem of investigating the dynamics of biped systems, the motion of the links is partly known, while the unknown moments are are equal zero. Vani Vanish shin ing g of the the give given n moment moment results results from the equilibrium equilibrium condit condition ionss about about the suppor supportin ting g point point (ZMP) (ZMP) and about about the joints joints of passiv passivee links.
Walk Master: Trajectory of ZMP and projected Center of gravity.
Using ZMP concept, the researchers in the Kato Kato Labora Laborator tory y elabor elaborated ated threethreedimensional graphics of a walking walking robot in 1984. This system enabled the analysis of ZMP in the course of biped robot's Walking and the composition of a walking pattern
combined with the robot’s actuators' characterist characteristics.. ics.. Trajectories Trajectories of the (n-3) coordinates can be prescribed so as to ensure the dynamic equilibrium of the overall system (the trunk motion including the arms if the biped robot is in question). If there be some supplementary supplementary ZMPs (like passive passive joints of the biped arms), then for every additional additional ZMP another another three equilibrium equilibrium conditions are available.
On three- dimensional graphics. The ZMP conc concep eptt and and semi semi-i -inv nver erse se meth method od was was elaborated elaborated in the furthe furtherr resear research. ch. Ichiro Ichiro
Kato and his associates were the first who realized dynamic walking compensation with the body. A walking bipedal robot must be able to set its own gait so as to be capable of adapting to rough terrain, or avoiding obstacles. So these researchers developed the WL-12 with a body that stabilized its own gait. The WL12 was capable of performing 30-cm steps in 2.6 s, using a newly proposed algorithm that that auto automa mati tica call lly y comp compos osed ed the the time time trajec trajector tory y of the body body while while arbi arbitr trar arily ily giving the trajectory of the lower limbs and ZMP. Based on the same ZMP method, the authors from Honda R & D Co. Ltd. Wako Research Center have presented [14-15] the HONDA HONDA Humanoid Humanoid Robot Robot – the most successful successful result in biped locomotion locomotion to date. Among many research activities in the domain of humanoid robots (modeling and control) I would like to emphasize the importance of a big and very promising project on Virtual Virtual Humanoid Humanoid Robot Platform. Platform. The ZMP method has recently recently attracted tremendous interest of researchers and has found very attractive applications in
humanoid, biped and multi-legged robots. It was demonstrated demonstrated that the ZMP method provides a quite useful dynamic criterion for the char charac acte teri riza zattion and and moni monito torring ing of the the huma human/ n/hu huma mano noid id robot locomotion. locomotion. The concept of ZMP is also very useful for for the analysis and control of the human gait in rehabilitation robotics.
5 CONTROL SCHEMES OF ROBOTS DYNAMIC APPROACH TO GENERATION OF TRAJECTORIES FOR ROBOTIC MANIPULATORS.
Dynamic approach to generating robotic trajectori ories is is the method for an optimal synthesis of manipulation robot trajectories. It was proposed first in 1982, whereby the system was considered as a complete, nonlinear dynamic model of the mech mechan anis ism m and and actu actuat ator orss. Regarding the practical importance of the energy for optimal motion synthesis ensuring simultaneou simultaneously sly a smooth, smooth, jerkless jerkless motion and minimal actuators’ strains, a particular attention was paid to the energy needed for an opti optimal mal moti motion on of nonre nonredunda dundant nt manipulators. A procedure for the dynamic synt synthe hesi siss of redu redund ndan antt mani manipu pula lato tor r trajectories was proposed for the first time in 1984. This procedure procedure was not really really dynamic for the reason that the system was presented by the kinematic model, but the optimality criterion was a dynamic one. Thismeth Thismethod od exhibi exhibited ted consid considera erable ble advantages over the ki kinematic approaches in the cases of manipulation of heavy object objectss by large, large, powerful robots, robots, and high-speed high-speed manipulation manipulation with highenergy consumption. CENT CENTRA RALI LIZE ZED D FEED FEED-F -FOR ORWA WAR RD CONTROL IN ROBOTICS
The centralized feed-forward control is one of the dynamic control laws which have been effectively used in practice. It includes the so-cal so-called led nomina nominall progra programme mmed d control control,, which compensates compensates for the dynamics dynamics of the overall mechanism along the nominal nominal trajectory. trajectory. The centralized centralized feedforward forward for the application application in biped locomotion locomotion systems systems was was proposed proposed in the early early papers papers . With With the biped biped walki walking ng machines, an accurate tracking of the precalculated nominal trajectories, achievable by the application of the centralized feedforwar forward d control, control, was a prerequ prerequisi isite te for ensuring ensuring dynamic dynamic equilibrium equilibrium during the walk. The centralized feed-forward control
to
manipulation robots was introduced by Vukobratovic Vukobratovic and Stokic.As Stokic.As compared to other dynamic control laws (e.g. the socalled inverse dynamics or computed torque method), method), the centralized centralized feed-forwa feed-forward rd has exhibited exhibited considerable considerable advantages advantages such as higher robustness, simpler control scheme, requiring no changes in the basic structure of the classical servo-s o-system schemes, etc. Th e application of centralized feed-forward in the commercial industrial robot controllers that showed full effectiveness effectiveness of the proposed approach has begun a number of years later. Optimal feed-forward control speeds up the motion of mechatronic systems near to the physical limits. In the recent applications, realreal- time time optimal optimal feed-f feed-forwa orward rd control control enhanced the international competitiveness of the leading robot manufacturers.Also, the robotin-theloop loop mathem mathemati atical cal optimiz optimizati ation on reduced reduced drasticall drastically y the time needed for robot controller tuning. ROBOT CONTROL
DYNAMIC
The first idea of applying dynamic control to robots originate originated d from the goal to track a prescribed trajectory by the anthropomorphic active active mechanisms mechanisms,, specifically specifically biped locomotion systems. Vukobratovic and Juricic suggested a dynamic control scheme consisting of a feed-forward path (based (based on the the comp comple lete te dyna dynami micc mode modell of the the system system)) and feedbac feedback k path path,, where where the role of the feed- forward forward compensation compensation is to cancel the nonlinearities of the nominal dynamics of the system. Several years later, such approach was proposed and elaborated for the joint space dynamic dynamic control of manipulation robots .
APPLICATIONS OF HUMANOID ROBOTS HUMANOID ROBOTS AS SOLDIERS •
Humanoids can be a prospectus soldiers soldiers as they have no feelings, feelings, follow follow all the orders orders without without questioning questioning and don’t get tired by looking for prospectus danger in any side continuousl continuously y for days or months, months, whereas whereas the humans get tired tired and thus their efficiency efficiency decreases.
•
Pentagon hires British scientist to help build robot soldiers that 'won't commit war crimes'
•
The US Army and Navy have both hired experts in the ethics of building machi achine ness to to pre preve vent nt the crea creattion of anamo namoral Terminatorstyle killing machine that murders indiscriminately. Last month the US Army took delivery of a new robot built by an American subsidiary subsidiar y of the British British defense company QinetiQ, which can fire everything from bean bags and pepper spray to high-explosive grenades and a 7.62mm machine gun. •
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ROBOT TEACHERS IN CLASS BY ITSELF Japan's robot teacher calls roll, • smiles and scolds, drawing laughter from students students with her eerily eerily lifelike lifelike face. But the developer says it's not about to replace human instructors. Unlike more mechanical-looking • robots such as Honda Motor Co.'s Asimo, the robot teacher, called Saya, can expre express ss six six basic basic emot emotio ions ns -surpri surprise, se, fear, fear, disgust disgust,, anger, anger, happiness, happiness, sadness -- because because its rubber skin is being pulled from the back with motors and wiring around the eyes and the mouth.
ROBOTS AS SECURITY GUARDS •
•
•
Schools in Korea could soon be guarded guarded by hi-tech robots that will patrol patrol their grounds, according to reports. Sadly for anybody hoping for a Terminator, Terminator, Robocop or even a Johnny 5, OFRO has a top speed of just 5kmph, and is equipped with a camera and microphone rather than a big gun. And rather than a giant metal person, person, it looks more like a large wireless router stuck onto a tiny tank, with a periscope bolted onto it.
Japanes Japanesee roboti robotics cs company company Tmsuk has announced announced its latest latest crea creati tion, on, the the T63 Arte Artemi miss Guard Robot. Artemis will autonomously autonomously patrol a multi-st multi-story ory building and report back wirelessly to securi security ty HQ if it finds anything anything amiss. Though not yet yet capable of apprehending any intruders, it is armed with several non-lethal offe offens nsiv ivee weap weapon onss such such as a fluore fluoresce scent nt paintb paintball all gun and the capability to spray a cloud of mist to temporarily blind the intruder. ROBOTS AS MAIDS:
Now the Japanese have caught up with the Jetsons -- with their tea serving humanoid
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robot HRP-2. HRP-2. The Voltron-lo Voltron-looking oking robot even does your dishes! Take that, The HRP2 was was part part of of a demons demonstra tratio tion n at the Univer University sity of Tokyo, Tokyo, led by Profes Professor sor Tomomasa Sato.
CONCLUSION:
Thus at the end we would like to say that human like robots are very well possible and useful in siting the limitations and risk factors with the human workers in different working atmospheres and areas. The observation and the analysis of human walking walking is an important important inspiration inspiration in the design of our control algorithms. We do not aim to copy th t he comp compllexit exity y of living struct structures ures,, but to understand and find answers to our specific ques questi tion onss by obse observ rvin ing g the anth anthro ropo pomo morp rphi hicc ch oi ce s in t h e locomotion activity. We think there is great advantage in working together with people who are involved in the problem of biped locomotion from a biological point of view. The interaction of our experiences should be helpful for both fields.
REFERENCES:
1. Vuko Vukobr brat atov oviic M., M., Hris Hristi ticc D., D., Stoj Stojil iljko jkovi vicc Z.: Z.: Deve Develo lopme pment nt of Active Anthropomorphic Exoskeletons, Medical and Biological Engineering, Vol. 12, No. 1, 1974 2. Vuko Vukobr brat atov oviic M.: Legged Locomotion Robots and Anthropomor Anthropomorphic phic Mechanisms Mechanisms (in English), research monograph, Miha Mihail ilo o Pupi Pupin n Inst Instit itut ute, e, Belg Belgra rade de,, 1975 1975,, also also publ publis ishe hed d in Japa Japane nese se,, Nikkan Shumun Shumun Ltd. Tokyo, Tokyo, 1975, in Russian "MIR", Moscow, 1976, in Chinese, Beijing, 1983 3. Hristic D., Vukobratovic M.:A M.:Act ctiive Exos Exoske kelleton etonss Future Future Rehabil Rehabilita itatio tion n Aids Aids for Severe Severely ly Handica Handicapped pped Person Persons, s, Orthopedie Orthopedie Technique, 12/1976 pp. 221-224, Stuttgart, Germany 4. Vukobratovic M., Borovac B., Surla D., Stokic D.: Scientific Fundamental Fundamentalss of Robotics, Robotics, Vol. 7, Biped Locomotion:Dynamics,Stability,Cont Locomotion:Dynamics,Stability,Cont rol and Application, Springer-Verlag 1989 5. Vuko ukobratovic vic M., Boro orovac B., Stokic Stokic D., Surdil Surdilovic ovic D.: Acti Active ve Exos Exoskel kelet eton on,, Ch. 27: 27: Human Humanoi oid d Robots, pp. 727-777, Mechanical Syst System emss Desig Design n Hand Handboo book: k: Modeling, Modeling, Measure Measure and Control, Control, CRC Press, 2001 6. Azev Azeved edo o C. and and the BIP BIP team eam “Control Architecture and Algorithms of the Anthropomorphic Biped Robot BIP2000”, CLAWAR Madrid, October 2000 7. Berme Berme N. “Contr “Control ol and Movemen Movementt of lower lower limbs”, limbs”, A. Moreck Morecki, i, “Biomechanics of Motion” Springer
Verlag, CISM,1980. CISM,1980. THANK U
