1395 60.Biologically Inspired Robots Jean-Arcady Meyer,Agnes Guillot After having stressed the difference between 60.3.5Ta5te..1402 bio-inspired and biomimetic robots,this chapter 60.3.6 Internal Sensors................... 1402 successively describes bio-inspired morphologies, 60.4 Bio-inspired Actuators...................... 1402 sensors,and actuators.Then,control architecture 60.4.1L0c0m0ti0n.… 1402 that,beyond mere reflexes,implement cognitive 60.4.2 Grasping 1407 abilities like memory or planning,or adaptive pro- 60.4.3 Drilling… 1408 cesses like learning,evolution and development 60.5 Bio-inspired Control Architectures........1408 are described.Finally,the chapter also reports 60.5.1 Behavior-Based Robotics.........1408 related works on energetic autonomy,collective 60.5.2 Learning Robots. .1409 robotics,and biohybrid robots. 60.5.3 Evolving Robots..... 1410 60.5.4 Developing Robots.......... 1411 60.6 Energetic Autonomy 1412 60.1 General Background .1395 60.7 Collective Robotics 1413 60.2 Bio-inspired Morphologies 1396 60.3 Bio-inspired Sensors......................1.398 60.8 Biohybrid Robots........1415 60.3.1Visi0n..1398 60.9 Discussion..... .1417 60.3.2 Auditic0n.… 1399 品 60.3.3T0uch.1400 60.10C0 nclusi0n.1418 n 60.3.4 Smell......... 1402 References ...... ..1418 8 60.1 General Background Human inventors and engineers have always found in electronics,and computer science than from biology. Nature's products an inexhaustible source of inspiration.On the one hand,this approach undoubtedly solidified About 2400 years ago,for instance,Archytas of Taren-the technical foundations of the discipline and led to tum allegedly built a kind of flying machine,a wooden the production of highly successful products,especially pigeon balanced by a weight suspended from a pul-in the field of industrial robotics.On the other hand,it ley,and set in motion by compressed air escaping from served to better appreciate the gap that still separates a valve.Likewise,circa 105 AD,the Chinese eunuch a robot from an animal,at least when qualities of au- Ts'ai Lun is credited with inventing paper,after watch-tonomy and adaptation are sought.As such qualities ing a wasp create its nest.More recently,Antoni Gaudi's are required in a continually growing application field design of the still-unfinished Sagrada Familia cathe--from planetary exploration to domestic uses-a spec- dral in Barcelona displays countless borrowings from tacular reversal of interest towards living creatures can mineral and vegetal exuberance. be noticed in current-day robotics,up to the point that it Although a similar tendency underlied all attempts has been said that natural inspiration is the new wave of at building automata or protorobots up to the middle of robotics [60.2]. the last century [60.1],in the last decades roboticists Undoubtedly,this new wave would not have been borrowed much more from mathematics,mechanics. possible without the synergies generated by recent
1395 Biologically In 60. Biologically Inspired Robots Jean-Arcady Meyer, Agnès Guillot After having stressed the difference between bio-inspired and biomimetic robots, this chapter successively describes bio-inspired morphologies, sensors, and actuators. Then, control architecture that, beyond mere reflexes, implement cognitive abilities like memory or planning, or adaptive processes like learning, evolution and development are described. Finally, the chapter also reports related works on energetic autonomy, collective robotics, and biohybrid robots. 60.1 General Background ............................ 1395 60.2 Bio-inspired Morphologies ................... 1396 60.3 Bio-inspired Sensors............................ 1398 60.3.1 Vision ....................................... 1398 60.3.2 Audition ................................... 1399 60.3.3 Touch ....................................... 1400 60.3.4 Smell ........................................ 1402 60.3.5 Taste ........................................ 1402 60.3.6 Internal Sensors ......................... 1402 60.4 Bio-inspired Actuators ......................... 1402 60.4.1 Locomotion ............................... 1402 60.4.2 Grasping ................................... 1407 60.4.3 Drilling ..................................... 1408 60.5 Bio-inspired Control Architectures ........ 1408 60.5.1 Behavior-Based Robotics ............ 1408 60.5.2 Learning Robots ......................... 1409 60.5.3 Evolving Robots ......................... 1410 60.5.4 Developing Robots ..................... 1411 60.6 Energetic Autonomy ............................ 1412 60.7 Collective Robotics ............................... 1413 60.8 Biohybrid Robots ................................. 1415 60.9 Discussion........................................... 1417 60.10 Conclusion .......................................... 1418 References .................................................. 1418 60.1 General Background Human inventors and engineers have always found in Nature’s products an inexhaustible source of inspiration. About 2400 years ago, for instance, Archytas of Tarentum allegedly built a kind of flying machine, a wooden pigeon balanced by a weight suspended from a pulley, and set in motion by compressed air escaping from a valve. Likewise, circa 105 AD, the Chinese eunuch Ts’ai Lun is credited with inventing paper, after watching a wasp create its nest. More recently, Antoni Gaudi’s design of the still-unfinished Sagrada Familia cathedral in Barcelona displays countless borrowings from mineral and vegetal exuberance. Although a similar tendency underlied all attempts at building automata or protorobots up to the middle of the last century [60.1], in the last decades roboticists borrowed much more from mathematics, mechanics, electronics, and computer science than from biology. On the one hand, this approach undoubtedly solidified the technical foundations of the discipline and led to the production of highly successful products, especially in the field of industrial robotics. On the other hand, it served to better appreciate the gap that still separates a robot from an animal, at least when qualities of autonomy and adaptation are sought. As such qualities are required in a continually growing application field – from planetary exploration to domestic uses – a spectacular reversal of interest towards living creatures can be noticed in current-day robotics, up to the point that it has been said that natural inspiration is the new wave of robotics [60.2]. Undoubtedly, this new wave would not have been possible without the synergies generated by recent Part G 60
1396 Part G Human-Centered and Life-Like Robotics advances in biology-where so-called integrative ap- ties of a continuum in which.on the one side,engineers proaches now produce a huge amount of data and models seek to reproduce some natural result,but not necessar- directly exploitable by roboticists-and in technology ily the underlying means,while,on the other side,they -with the massive availability of low-cost and power- seek to reproduce both the result and the means.Thus, efficient computing systems,and with the development bio-inspired robotics tends to adapt to traditional engi- of new materials exhibiting new properties.This will be neering approaches some principles that are abstracted demonstrated in this chapter,which first reviews recent from the observation of some living creature,whereas research efforts in bio-inspired morphologies,sensors, biomimetic robotics tends to replace classical engineer- and actuators.Then,control architectures that,beyond ing solutions by as detailed mechanisms or processes mere reflexes,implement cognitive abilities-like mem-that it is possible to reproduce from the observation ory or planning-or adaptive processes-like learning,of this creature.In practice,any specific application evolution and development-will be described.Finally,usually lies somewhere between these two extremities. the chapter will also report related works on energetic Be that as it may,because biomimetic realizations are autonomy,collective robotics,and biohybrid robots. always bio-inspired,whereas the reverse is not neces- It should be noted that this chapter will describe sarily true,qualifying expressions like bio-inspired or both bio-inspired and biomimetic realizations.In fact, biologically inspired will be preferentially used in this these two terms characterize,respectively,the extremi- chapter. 60.2 Bio-inspired Morphologies Although not comparable to that of real creatures,the di- pressions,eye,head,and body movements,and gestures versity of bio-inspired morphologies that may be found with its arms and hands.Touch sensors with sensitivity in the realm of robotics is nevertheless quite impres- to variable pressures are mounted under its clothing and sive.Currently,a huge number of robots populates the silicone skin,while floor sensors and omnidirectional Part terrestrial,as well as aquatic and aerial,environments vision sensors serve to recognize where people are in a and look like animals as diverse as dogs,kangaroos, order to make eye contact while addressing them during sharks,dragonflies,or jellyfishes,not to mention humans conversation.Moreover,it can respond to the content Fig.60.1). and prosody of a human partner by varying what it says In nature,the morphology of an animal fits its ecol- and the pitch of its voice (Fig.60.2c).See Chap.58 for ogy and behavior.In robotics applications,bio-inspired more references on human-friendly robots. morphologies are seldom imposed by functional consid- Another active research area in which functional erations.Rather,as close a resemblance as possible to considerations play a major role is that of shape-shifting a given animal is usually sought per se,as in animatron- robots that can dynamically reconfigure their morphol- ics applications for entertainment industry.However, ogy according to internal or external circumstances. several other applications are motivated by the func- Biological inspiration stems from organisms that can tional objective of facilitating human-robot interactions,regrow lost appendages,like the tail in lizards,or from thus allowing,for instance,children or elderly people transitions in developmental stages,like morphogenetic to adopt artificial pets and enjoy their company.Such changes in batrachians.For instance,the base topology interactions are facilitated in the case of so-called an- of the Conro self-reconfigurable robot developed in the thropopathic or human-friendly robots,such as Kismet Polymorphic Robotics Laboratory at USC-ISI is simply at MIT [60.3]or WE-4RII at Waseda University [60.4], connected as in a snake,but the system can reconfigure which are able to perceive and respond to human emo- itself in order to grow a set of legs or other specialized ap- tions,and do themselves express apparent emotions pendages(Fig.60.3)thanks to a dedicated hormone-like influencing their actions and behavior(Fig.60.2a,b). adaptive communication protocol [60.6,7]. Likewise,the Uando robot of Osaka Univer- Chapter 39 is devoted to distributed and cellular sity [60.5]is controlled by air actuators providing 43 robots and provides other examples of such reconfig- degrees of freedom.The android can make facial ex- urable robots
1396 Part G Human-Centered and Life-Like Robotics advances in biology – where so-called integrative approaches now produce a huge amount of data and models directly exploitable by roboticists – and in technology – with the massive availability of low-cost and powerefficient computing systems, and with the development of new materials exhibiting new properties. This will be demonstrated in this chapter, which first reviews recent research efforts in bio-inspired morphologies, sensors, and actuators. Then, control architectures that, beyond mere reflexes, implement cognitive abilities – like memory or planning – or adaptive processes – like learning, evolution and development – will be described. Finally, the chapter will also report related works on energetic autonomy, collective robotics, and biohybrid robots. It should be noted that this chapter will describe both bio-inspired and biomimetic realizations. In fact, these two terms characterize, respectively, the extremities of a continuum in which, on the one side, engineers seek to reproduce some natural result, but not necessarily the underlying means, while, on the other side, they seek to reproduce both the result and the means. Thus, bio-inspired robotics tends to adapt to traditional engineering approaches some principles that are abstracted from the observation of some living creature, whereas biomimetic robotics tends to replace classical engineering solutions by as detailed mechanisms or processes that it is possible to reproduce from the observation of this creature. In practice, any specific application usually lies somewhere between these two extremities. Be that as it may, because biomimetic realizations are always bio-inspired, whereas the reverse is not necessarily true, qualifying expressions like bio-inspired or biologically inspired will be preferentially used in this chapter. 60.2 Bio-inspired Morphologies Although not comparable to that of real creatures, the diversity of bio-inspired morphologies that may be found in the realm of robotics is nevertheless quite impressive. Currently, a huge number of robots populates the terrestrial, as well as aquatic and aerial, environments and look like animals as diverse as dogs, kangaroos, sharks, dragonflies, or jellyfishes, not to mention humans (Fig. 60.1). In nature, the morphology of an animal fits its ecology and behavior. In robotics applications, bio-inspired morphologies are seldom imposed by functional considerations. Rather, as close a resemblance as possible to a given animal is usually sought per se, as in animatronics applications for entertainment industry. However, several other applications are motivated by the functional objective of facilitating human–robot interactions, thus allowing, for instance, children or elderly people to adopt artificial pets and enjoy their company. Such interactions are facilitated in the case of so-called anthropopathic or human-friendly robots, such as Kismet at MIT [60.3] or WE-4RII at Waseda University [60.4], which are able to perceive and respond to human emotions, and do themselves express apparent emotions influencing their actions and behavior (Fig. 60.2a,b). Likewise, the Uando robot of Osaka University [60.5] is controlled by air actuators providing 43 degrees of freedom. The android can make facial expressions, eye, head, and body movements, and gestures with its arms and hands. Touch sensors with sensitivity to variable pressures are mounted under its clothing and silicone skin, while floor sensors and omnidirectional vision sensors serve to recognize where people are in order to make eye contact while addressing them during conversation. Moreover, it can respond to the content and prosody of a human partner by varying what it says and the pitch of its voice (Fig. 60.2c). See Chap. 58 for more references on human-friendly robots. Another active research area in which functional considerations play a major role is that of shape-shifting robots that can dynamically reconfigure their morphology according to internal or external circumstances. Biological inspiration stems from organisms that can regrow lost appendages, like the tail in lizards, or from transitions in developmental stages, like morphogenetic changes in batrachians. For instance, the base topology of the Conro self-reconfigurable robot developed in the Polymorphic Robotics Laboratory at USC-ISI is simply connected as in a snake, but the system can reconfigure itself in order to grow a set of legs or other specialized appendages (Fig. 60.3) thanks to a dedicated hormone-like adaptive communication protocol [60.6, 7]. Chapter 39 is devoted to distributed and cellular robots and provides other examples of such reconfigurable robots. Part G 60.2
Biologically Inspired Robots 60.2 Bio-inspired Morphologies 1397 6 Part G 60.2 Fig.60.1 A collection of zoomorphic robots b c) Fig.60.2a-c Three humanoid robots.(a)Kismet CRodney Brooks,Computer Science and Artificial Intelligence Lab, MIT(b)WE-4RII CAtsuo Takanishi Lab,Waseda University.(c)Uando CHiroshi Ishiguro,ATR Intelligent Robotics and Communication Lab.Osaka University
Biologically Inspired Robots 60.2 Bio-inspired Morphologies 1397 Fig. 60.1 A collection of zoomorphic robots a) b) c) Fig. 60.2a–c Three humanoid robots. (a) Kismet c Rodney Brooks, Computer Science and Artificial Intelligence Lab, MIT (b) WE-4RII c Atsuo Takanishi Lab, Waseda University. (c) Uando c Hiroshi Ishiguro, ATR Intelligent Robotics and Communication Lab, Osaka University Part G 60.2
1398 Part G Human-Centered and Life-Like Robotics Fig.60.3 A sequence reconfiguring a CONRO robot from a snake to a T-shaped creature with two legs.CWei-Min Shen, Polymorphic Robotics Laboratory,Univ.Southern California 60.3 Bio-inspired Sensors 60.3.1 Vision was exploited to implement optoelectronic devices al- lowing a terrestrial robot to wander in its environments Bio-inspired visual sensors in robotics range from very while avoiding obstacles [60.8],or tethered aerial robots simple photosensitive devices,which mostly serve to im- to track a contrasting target [60.9]or to automatically plement phototaxis,to complex binocular devices used perform terrain-following,take-off,or landing [60.10] for more cognitive tasks like object recognition. (Fig.60.4). Phototaxis is seldom the focus of dedicated research. The desert ant Cataglyphis,while probably merg- It is rather usually implemented merely to force a robot ing optic-flow and odometry monitoring to evaluate its to move and exhibit other capacities such as obstacle travel distances,is able to use its compound eyes to avoidance or inter-robot communication. perceive the polarization pattern of the sky and infer Part G160.3 Several visual systems calling upon optic-flow moni- its orientation.This affords it with accurate navigation toring are particularly useful in the context of navigation capacities that make it possible to explore its desert tasks and are implemented in a variety of robots.This is habitat for hundreds of meters while foraging,and re- the case with the work done in Marseilles'Biorobotics turn back to its nest on an almost straight line,despite Laboratory that serves to understand how the organiza- the absence of conspicuous landmarks and despite the tion of the compound eye of the housefly,and how the impossibility of laying pheromones on the ground that neural processing of visual information obtained during would not almost immediately evaporate.Inspired by flight,endow this insect with various reflexes mandatory the insect's navigation system,mechanisms for path for its survival.The biological knowledge thus acquired integration and visual piloting have been successfully 5 cm b) Fig.60.4a-c Optoelectronic devices inspired by the housefly's compound eye.(a)Device for obstacle avoidance.(b)De- vice for target tracking.(c)Device for terrain following,take-off,and landing.OCNRS Phototheque,Nicolas Franceschini, UMR6152-Mouvement et Perception-Marseille
1398 Part G Human-Centered and Life-Like Robotics Fig. 60.3 A sequence reconfiguring a CONRO robot from a snake to a T-shaped creature with two legs. c Wei-Min Shen, Polymorphic Robotics Laboratory, Univ. Southern California 60.3 Bio-inspired Sensors 60.3.1 Vision Bio-inspired visual sensors in robotics range from very simple photosensitive devices, which mostly serve to implement phototaxis, to complex binocular devices used for more cognitive tasks like object recognition. Phototaxis is seldom the focus of dedicated research. It is rather usually implemented merely to force a robot to move and exhibit other capacities such as obstacle avoidance or inter-robot communication. Several visual systems calling upon optic-flow monitoring are particularly useful in the context of navigation tasks and are implemented in a variety of robots. This is the case with the work done in Marseilles’ Biorobotics Laboratory that serves to understand how the organization of the compound eye of the housefly, and how the neural processing of visual information obtained during flight, endow this insect with various reflexes mandatory for its survival. The biological knowledge thus acquired a) b) c) 5 cm Fig. 60.4a–c Optoelectronic devices inspired by the housefly’s compound eye. (a) Device for obstacle avoidance. (b) Device for target tracking. (c) Device for terrain following, take-off, and landing.c CNRS Photothèque, Nicolas Franceschini, UMR6152 - Mouvement et Perception - Marseille was exploited to implement optoelectronic devices allowing a terrestrial robot to wander in its environments while avoiding obstacles [60.8], or tethered aerial robots to track a contrasting target [60.9] or to automatically perform terrain-following, take-off, or landing [60.10] (Fig. 60.4). The desert ant Cataglyphis, while probably merging optic-flow and odometry monitoring to evaluate its travel distances, is able to use its compound eyes to perceive the polarization pattern of the sky and infer its orientation. This affords it with accurate navigation capacities that make it possible to explore its desert habitat for hundreds of meters while foraging, and return back to its nest on an almost straight line, despite the absence of conspicuous landmarks and despite the impossibility of laying pheromones on the ground that would not almost immediately evaporate. Inspired by the insect’s navigation system, mechanisms for path integration and visual piloting have been successfully Part G 60.3
Biologically Inspired Robots 60.3 Bio-inspired Sensors 1399 employed on mobile robot navigation in the Sahara desert [60.11]. a Among the robotic realizations that are targeted at humanoid vision,some aim at integrating informa- tion provided by foveal and peripheral cameras.Ude et al.[60.12],in particular,describe a system that uses shape and color to detect and pursue objects through pe- ripheral vision and then recognizes the object through a more detailed analysis of higher-resolution foveal im- ages.The classification is inferred from a video stream rather than from a single image and,when a desired ob- ject is recognized,the robot reaches for it and ignores other objects(Fig.60.5).Common alternatives to the use of two cameras per eye consist of using space-variant vi- sion and,in particular,log-polar images.As an example, Metta [60.13]describes an attentional system that should be extended with modules for object recognition,trajec- Fig.60.5 (a)Four cameras implement foveal and peripheral vision tory tracking,and naive physics understanding during in the head of the humanoid robot DB.Foveal cameras are above the natural interaction of a robot with the environment. peripheral cameras.OJST.ATR Robot developed by SARCOS Other examples of robotic applications of percep- (b)The HRP2 humanoid robot Kawada Industries Inc./National tual processes underlying human vision are provided Institute of Advanced Industrial Science and Technology (AIST) in Chap.63 on perceptual robotics. Vision-based simultaneous localization and map- taxis behavior or more complex capacities such as object ping (SLAM)systems have also been implemented recognition. on humanoid robots,with the aim of increasing the At the University of Edinburgh,numerous research autonomy of these machines.In particular,Davison efforts are devoted to understanding the sensory-motor et al.[60.14]used the HRP2 robot (Fig.60.5)to pathways and mechanisms that underlie positive or demonstrate real-time SLAM capacities during agile negative phonotaxis behavior in crickets through the im- Part G combinations of walking and turning motions,using plementation of various models on diverse robots such the robot's internal inertial sensors to monitor a type as the Khepera shown on Fig.60.6.In particular,an ana- of three-dimensional odometry that reduced the local logue very-large-scale integrated(VLSI)circuit models w rate of increase in uncertainty within the SLAM map.the auditory mechanism that enables a female cricket to The authors speculate that the availability of traditional meet a conspecific male or to evade a bat(by the calling odometry on all of the robot's degrees of freedom will song or the echolocation calls they produce,respec- allow more long-term motion constraints to be im- tively).The results suggest that the mechanism outputs posed and exploited by the SLAM algorithm,based a directional signal to sounds ahead at calling song fre- on knowledge of possible robot configurations.Addi- quency and to sound behind at echolocation frequencies, tional references to SLAM techniques are to be found and that this combination of responses simplifies later in Chap.37. neural processing in the cricket [60.16].This process- As another step towards autonomy in humanoid ing is the subject of complementary modeling efforts robots,mapping and planning capacities may be com-in which spiking neuron controllers are also tested on bined.Michel et al.[60.15],for instance,demonstrate robots,thus allowing the exploration of the function- that a real-time vision-based sensing system and an ality of the identified neurons in the insect,including adaptive footstep planner allow a Honda ASIMO robot the possible roles of multiple sensory fibers,mutually to autonomously traverse dynamic environments con- inhibitory connections,and brain neurons with pattern- taining unpredictably moving obstacles. filtering properties.Such robotic implementations also make the investigation of multimodal influences on the 60.3.2 Audition behavior possible,via the inclusion of an optomotor sta- bilization response and the demonstration that this may Like vision,the sense of hearing in animals has been improve auditory tracking,particularly under conditions implemented on several robots to exhibit mere phono- of random disturbance [60.17]
Biologically Inspired Robots 60.3 Bio-inspired Sensors 1399 employed on mobile robot navigation in the Sahara desert [60.11]. Among the robotic realizations that are targeted at humanoid vision, some aim at integrating information provided by foveal and peripheral cameras. Ude et al. [60.12], in particular, describe a system that uses shape and color to detect and pursue objects through peripheral vision and then recognizes the object through a more detailed analysis of higher-resolution foveal images. The classification is inferred from a video stream rather than from a single image and, when a desired object is recognized, the robot reaches for it and ignores other objects (Fig. 60.5). Common alternatives to the use of two cameras per eye consist of using space-variant vision and, in particular, log-polar images. As an example, Metta [60.13] describes an attentional system that should be extended with modules for object recognition, trajectory tracking, and naive physics understanding during the natural interaction of a robot with the environment. Other examples of robotic applications of perceptual processes underlying human vision are provided in Chap. 63 on perceptual robotics. Vision-based simultaneous localization and mapping (SLAM) systems have also been implemented on humanoid robots, with the aim of increasing the autonomy of these machines. In particular, Davison et al. [60.14] used the HRP2 robot (Fig. 60.5) to demonstrate real-time SLAM capacities during agile combinations of walking and turning motions, using the robot’s internal inertial sensors to monitor a type of three-dimensional odometry that reduced the local rate of increase in uncertainty within the SLAM map. The authors speculate that the availability of traditional odometry on all of the robot’s degrees of freedom will allow more long-term motion constraints to be imposed and exploited by the SLAM algorithm, based on knowledge of possible robot configurations. Additional references to SLAM techniques are to be found in Chap. 37. As another step towards autonomy in humanoid robots, mapping and planning capacities may be combined. Michel et al. [60.15], for instance, demonstrate that a real-time vision-based sensing system and an adaptive footstep planner allow a Honda ASIMO robot to autonomously traverse dynamic environments containing unpredictably moving obstacles. 60.3.2 Audition Like vision, the sense of hearing in animals has been implemented on several robots to exhibit mere phonoa) b) Fig. 60.5 (a) Four cameras implement foveal and peripheral vision in the head of the humanoid robot DB. Foveal cameras are above peripheral cameras. c JST, ATR Robot developed by SARCOS. (b) The HRP2 humanoid robot c Kawada Industries Inc./ National Institute of Advanced Industrial Science and Technology (AIST) taxis behavior or more complex capacities such as object recognition. At the University of Edinburgh, numerous research efforts are devoted to understanding the sensory–motor pathways and mechanisms that underlie positive or negative phonotaxis behavior in crickets through the implementation of various models on diverse robots such as the Khepera shown on Fig. 60.6. In particular, an analogue very-large-scale integrated (VLSI) circuit models the auditory mechanism that enables a female cricket to meet a conspecific male or to evade a bat (by the calling song or the echolocation calls they produce, respectively). The results suggest that the mechanism outputs a directional signal to sounds ahead at calling song frequency and to sound behind at echolocation frequencies, and that this combination of responses simplifies later neural processing in the cricket [60.16]. This processing is the subject of complementary modeling efforts in which spiking neuron controllers are also tested on robots, thus allowing the exploration of the functionality of the identified neurons in the insect, including the possible roles of multiple sensory fibers, mutually inhibitory connections, and brain neurons with pattern- filtering properties. Such robotic implementations also make the investigation of multimodal influences on the behavior possible, via the inclusion of an optomotor stabilization response and the demonstration that this may improve auditory tracking, particularly under conditions of random disturbance [60.17]. Part G 60.3
1400 Part G Human-Centered and Life-Like Robotics Fig.60.6(a)A Khepera robot equipped with a cricket-like auditory system.CBarbara Webb,Institute for Perception,Action and Behaviour, University of Edinburgh.(b)The CIRCE robotic bat head cHerbert Peremans,Active Perception Lab, Universiteit Antwerpen Concerning more cognitive capacities,within the visual integration.thus making localization,separation. framework of the European Community (EC)project and recognition of three simultaneous speech sources chiroptera-inspired robotic cephaloid (CIRCE),a bat possible. head (Fig.60.6)is used to investigate how the world is not just perceived,but actively explored,by bats. In particular,the work aims at identifying how vari- ous shapes,sizes,and movements influence the signals that the animal receives from its environment [60.18].It is hoped that the principles gleaned from such work will prove useful in developing better antennas,particularly for wireless devices that are in motion and need to pick Part GI up complex signals from different directions. Likewise.the Yale Sonar Robot.which is modeled after bat and dolphin echolocation behavior,is said to be so sensitive that it can tell whether a tossed coin w has come up heads or tails.Called Rodolph-short for robotic dolphin-the robot is equipped with electrostatic transducers that can act either as transmitters or receivers to serve as the robot's mouth and ears.The design is b) inspired by bats,whose ears react by rotating in the direction of an echo source,and by dolphins,which appear to move around in order to place an object at a standard distance,thus reducing the complexity of object recognition [60.19].Additional references to bio- inspired sonars are to be found in Chap.21,dedicated to sonar sensing. Nakadai et al.[60.20]describe a system that allows a humanoid robot to listen to a specific sound in under noisy environments(the human capability known as the cocktail-party effect)and to listen to several sources of speeches simultaneously,thus allowing it to cope with situations where someone or something playing sounds Fig.60.7 (a)A simple antenna mounted on a Sprawlette interrupts conversation (known as barge-in in spoken robot Mark R.Cutkosky,Center for Design Research, dialog systems).This system calls upon active motions Stanford University.(b)A more advanced tactile device directed at the sound source to improve localization by CNoah J.Cowan,Department of Mechanical Engineering, exploiting an auditory fovea.It also capitalizes on audio- Johns Hopkins University
1400 Part G Human-Centered and Life-Like Robotics a) b) Fig. 60.6 (a) A Khepera robot equipped with a cricket-like auditory system. c Barbara Webb, Institute for Perception, Action and Behaviour, University of Edinburgh. (b) The CIRCE robotic bat head c Herbert Peremans, Active Perception Lab, Universiteit Antwerpen Concerning more cognitive capacities, within the framework of the European Community (EC) project chiroptera-inspired robotic cephaloid (CIRCE), a bat head (Fig. 60.6) is used to investigate how the world is not just perceived, but actively explored, by bats. In particular, the work aims at identifying how various shapes, sizes, and movements influence the signals that the animal receives from its environment [60.18]. It is hoped that the principles gleaned from such work will prove useful in developing better antennas, particularly for wireless devices that are in motion and need to pick up complex signals from different directions. Likewise, the Yale Sonar Robot, which is modeled after bat and dolphin echolocation behavior, is said to be so sensitive that it can tell whether a tossed coin has come up heads or tails. Called Rodolph – short for robotic dolphin – the robot is equipped with electrostatic transducers that can act either as transmitters or receivers to serve as the robot’s mouth and ears. The design is inspired by bats, whose ears react by rotating in the direction of an echo source, and by dolphins, which appear to move around in order to place an object at a standard distance, thus reducing the complexity of object recognition [60.19]. Additional references to bioinspired sonars are to be found in Chap. 21, dedicated to sonar sensing. Nakadai et al. [60.20] describe a system that allows a humanoid robot to listen to a specific sound in under noisy environments (the human capability known as the cocktail-party effect) and to listen to several sources of speeches simultaneously, thus allowing it to cope with situations where someone or something playing sounds interrupts conversation (known as barge-in in spoken dialog systems). This system calls upon active motions directed at the sound source to improve localization by exploiting an auditory fovea. It also capitalizes on audiovisual integration, thus making localization, separation, and recognition of three simultaneous speech sources possible. a) b) Fig. 60.7 (a) A simple antenna mounted on a Sprawlette robot c Mark R. Cutkosky, Center for Design Research, Stanford University. (b) A more advanced tactile device c Noah J. Cowan,Department of Mechanical Engineering, Johns Hopkins University Part G 60.3
Biologically Inspired Robots 60.3 Bio-inspired Sensors 1401 60.3.3 Touch sensory receptors,a rat's whisker consists of a sin- gle,flexible,tapered hair and has tactile sensors located It is often asserted that,of all the five senses,touch only at its base.The way in which two arrays of such is the most difficult to replicate in mechanical form. sensors afford capacities of obstacle avoidance,tex- Be that as it may,a passive,highly compliant tactile ture discrimination,and object recognition has inspired sensor has been designed for the hexapedal running several robotic realizations,notably that described by robot Sprawlette at Stanford,drawing inspiration from Russel and Wijaya [60.22]in which the whiskers are how the cockroach Periplaneta americana uses antenna passive and rely upon the motion of the robot in or- feedback to control its orientation during a rapid wall-der to scan the surface profile of touched objects.The following behavior.Results on the stabilization of the robot is able to recognize a few objects formed from robot suggest that the cockroach uses,at least in part,plane,cylindrical,and spherical surfaces.By using its the rate of convergence to the wall-or tactile flow-to simple manipulator,it can pick up and retrieve small control its body orientation [60.21].To make it possible objects. to detect the point of greatest strain,or to differentiate Conversely,Pearson et al.[60.23]describe a touch between different shapes the sensor is bent into,more system based on computational models of whisker- advanced versions of the antenna are currently under related neural circuitry in the rat brain,in which development(Fig.60.7). the whiskers will be actively scanning the surround- While a cockroach's antenna consists of multiple ings.This work will contribute to the EC ICEA rigid segments and is covered along its length with (integrating cognition,emotion,and autonomy http://www2.his.se/icea/)project whose primary aim is to develop a cognitive systems architecture based on the anatomy and physiology of the mammalian brain. In the field of humanoid robotics,investigations on touch sensors are being conducted at the University of Tokyo,where a robotic hand calling upon organic transistors as pressure sensors(Fig.60.8a)has been pro- duced.The same technology served to make a flexible artificial skin that can sense both pressure and tempera- Part ture(Fig.60.8b),thus more closely imitating the human sense of touch [60.24]. Another step in this direction has been made at the w University of Nebraska [60.25],where a thin-film tac- tile sensor,which is as sensitive as the human finger in some ways,has been designed.When pressed against b) a textured object,the film creates a topographical map of the surface,by sending out both an electrical signal Fig.60.8a,b Artificial skin devices at Tokyo University.Fig.60.9 (a)The optical image of a coin(b)The corre- (a)Pressure detection.(b)Pressure and temperature detec- sponding pressure image from the tactile sensor Ravi tion Takao Someya,Quantum-Phase Electronics Center, Saraf,Department of Chemical Engineering,University of The University of Tokyo Nebraska
Biologically Inspired Robots 60.3 Bio-inspired Sensors 1401 60.3.3 Touch It is often asserted that, of all the five senses, touch is the most difficult to replicate in mechanical form. Be that as it may, a passive, highly compliant tactile sensor has been designed for the hexapedal running robot Sprawlette at Stanford, drawing inspiration from how the cockroach Periplaneta americana uses antenna feedback to control its orientation during a rapid wallfollowing behavior. Results on the stabilization of the robot suggest that the cockroach uses, at least in part, the rate of convergence to the wall – or tactile flow – to control its body orientation [60.21]. To make it possible to detect the point of greatest strain, or to differentiate between different shapes the sensor is bent into, more advanced versions of the antenna are currently under development (Fig. 60.7). While a cockroach’s antenna consists of multiple rigid segments and is covered along its length with a) b) Fig. 60.8a,b Artificial skin devices at Tokyo University. (a) Pressure detection. (b) Pressure and temperature detection c Takao Someya, Quantum-Phase Electronics Center, The University of Tokyo sensory receptors, a rat’s whisker consists of a single, flexible, tapered hair and has tactile sensors located only at its base. The way in which two arrays of such sensors afford capacities of obstacle avoidance, texture discrimination, and object recognition has inspired several robotic realizations, notably that described by Russel and Wijaya [60.22] in which the whiskers are passive and rely upon the motion of the robot in order to scan the surface profile of touched objects. The robot is able to recognize a few objects formed from plane, cylindrical, and spherical surfaces. By using its simple manipulator, it can pick up and retrieve small objects. Conversely, Pearson et al. [60.23] describe a touch system based on computational models of whiskerrelated neural circuitry in the rat brain, in which the whiskers will be actively scanning the surroundings. This work will contribute to the EC ICEA (integrating cognition, emotion, and autonomy – http://www2.his.se/icea/) project whose primary aim is to develop a cognitive systems architecture based on the anatomy and physiology of the mammalian brain. In the field of humanoid robotics, investigations on touch sensors are being conducted at the University of Tokyo, where a robotic hand calling upon organic transistors as pressure sensors (Fig. 60.8a) has been produced. The same technology served to make a flexible artificial skin that can sense both pressure and temperature (Fig. 60.8b), thus more closely imitating the human sense of touch [60.24]. Another step in this direction has been made at the University of Nebraska [60.25], where a thin-film tactile sensor, which is as sensitive as the human finger in some ways, has been designed. When pressed against a textured object, the film creates a topographical map of the surface, by sending out both an electrical signal a) b) Fig. 60.9 (a) The optical image of a coin (b) The corresponding pressure image from the tactile sensor c Ravi Saraf, Department of Chemical Engineering, University of Nebraska Part G 60.3
1402 Part G Human-Centered and Life-Like Robotics and a visual signal that can be read with a small cam-chest of the humanoid WE-4RIIrobot of Waseda Univer- era.The spatial resolution of these maps is as good as sity(Fig.60.2)is equipped with two mechanical lungs, that achieved by human touch,as demonstrated by the each consisting of a cylinder and a piston,thanks to image obtained when placing a coin on this mechanical which the robot breathes air.Being also equipped with fingertip (Fig.60.9). four semiconductor gas sensors,it recognizes the smells Although such sensors deal with texture in a way that of alcohol,ammonia,and cigarette smoke [60.28]. is not at all like a fingertip,it has a high enough resolution to feel single cells,and therefore could help surgeons 60.3.5 Taste find the perimeter of a tumor during surgical procedures. Cancer cells,in particular breast cancer cells,have levels A first robot with a sense of taste has recently of pressure that are different from normal cells,and been developed by NEC System Technologies,Ltd. should feel harder to the sensor. Using infrared spectroscopic technology,this robot is capable of examining the taste of food and giving its 60.3.4 Smell name as well as its ingredients.Furthermore,it can give advice on the food and health issues based on the The way the nematod Caenorhabditis elegans uses information gathered.The latest developments afford chemotaxis-probably the most widespread form of the robot with the capacity to distinguish good wine goal-seeking behavior-to find bacterial food sources from bad wine,and Camembert from Gouda (http:// by following their odors has been investigated at the www.necst.co.jp/english/news/20061801/index.htm). University of Oregon.This worm has a small nervous system (302 neurons),whose neurons and connectivity 60.3.6 Internal Sensors pattern have been completely characterized,so the neu- ral circuit controlling chemotaxis is well known and, Whereas the previous external sensors all provide infor- when implemented in a robot,proves to be able to cope mation about an animal's or a robot's external world, with environmental variability and noise in sensory in- internal sensors provide information about a creature's puts [60.26].The long-term objective of such work is internal state.Although such so-called idiothetic sen- Part to design a cheap,artificial eel that could locate explo- sors are widespread in robotic applications,measuring sive mines at sea.Among the research efforts that tackle variables such as temperature,pressure,voltage,acceler- the related and highly challenging issue of reproducing ations,etc.,they are seldom biologically inspired,but in the odor-plume-tracking behavior in marine animals,re- the implementation of a variety of visual-motor routines sults obtained on the RoboLobster are put in perspective (smooth-pursuit tracking,saccades,binocular vergence, in[60.27]. and vestibular-ocular and optokinetic reflexes),like Other bio-inspired systems for odor recognition are those that are at work in the humanoid Cog robot under development in several places.For instance,the mentioned later. 60.4 Bio-inspired Actuators 60.4.1 Locomotion crawling,swimming,and walking-in a single robot.Be- ing inspired by central pattern generators(CPG)found Crawling in vertebrate spinal cords,this work demonstrates how Because they are able to move in environments inacces- a primitive neural circuit for swimming,like the one sible to humans,such as pipes or collapsed buildings, found in the lamprey,can be extended by phylogenet- numerous snake-like robots have been developed for ically more recent limb oscillatory centers to explain exploration and inspection tasks,as well as for partici- the ability of salamanders to switch between swimming pation in search-and-rescue missions.The Salamandra and walking.It also suggests a mechanism that explains Robotica(Fig.60.10)developed at the Ecole Polytech- how gait transition between swimming and walking can nique Federale de Lausanne (EPFL)in Switzerland be obtained by simply varying the level of stimulation extends these approaches because it is the first robot that of the brainstem,and provides a potential explanation combines the three modes of locomotion-serpentine of how salamanders control their speed and direction
1402 Part G Human-Centered and Life-Like Robotics and a visual signal that can be read with a small camera. The spatial resolution of these maps is as good as that achieved by human touch, as demonstrated by the image obtained when placing a coin on this mechanical fingertip (Fig. 60.9). Although such sensors deal with texture in a way that is not at all like a fingertip, it has a high enough resolution to feel single cells, and therefore could help surgeons find the perimeter of a tumor during surgical procedures. Cancer cells, in particular breast cancer cells, have levels of pressure that are different from normal cells, and should feel harder to the sensor. 60.3.4 Smell The way the nematod Caenorhabditis elegans uses chemotaxis – probably the most widespread form of goal-seeking behavior – to find bacterial food sources by following their odors has been investigated at the University of Oregon. This worm has a small nervous system (302 neurons), whose neurons and connectivity pattern have been completely characterized, so the neural circuit controlling chemotaxis is well known and, when implemented in a robot, proves to be able to cope with environmental variability and noise in sensory inputs [60.26]. The long-term objective of such work is to design a cheap, artificial eel that could locate explosive mines at sea. Among the research efforts that tackle the related and highly challenging issue of reproducing the odor-plume-tracking behavior in marine animals, results obtained on the RoboLobster are put in perspective in [60.27]. Other bio-inspired systems for odor recognition are under development in several places. For instance, the chest of the humanoid WE-4RII robot of Waseda University (Fig. 60.2) is equipped with two mechanical lungs, each consisting of a cylinder and a piston, thanks to which the robot breathes air. Being also equipped with four semiconductor gas sensors, it recognizes the smells of alcohol, ammonia, and cigarette smoke [60.28]. 60.3.5 Taste A first robot with a sense of taste has recently been developed by NEC System Technologies, Ltd. Using infrared spectroscopic technology, this robot is capable of examining the taste of food and giving its name as well as its ingredients. Furthermore, it can give advice on the food and health issues based on the information gathered. The latest developments afford the robot with the capacity to distinguish good wine from bad wine, and Camembert from Gouda (http:// www.necst.co.jp/english/news/20061801/index.htm). 60.3.6 Internal Sensors Whereas the previous external sensors all provide information about an animal’s or a robot’s external world, internal sensors provide information about a creature’s internal state. Although such so-called idiothetic sensors are widespread in robotic applications, measuring variables such as temperature, pressure, voltage, accelerations, etc., they are seldom biologically inspired, but in the implementation of a variety of visual–motor routines (smooth-pursuit tracking, saccades, binocular vergence, and vestibular-ocular and optokinetic reflexes), like those that are at work in the humanoid Cog robot mentioned later. 60.4 Bio-inspired Actuators 60.4.1 Locomotion Crawling Because they are able to move in environments inaccessible to humans, such as pipes or collapsed buildings, numerous snake-like robots have been developed for exploration and inspection tasks, as well as for participation in search-and-rescue missions. The Salamandra Robotica (Fig. 60.10) developed at the Ecole Polytechnique Fédérale de Lausanne (EPFL) in Switzerland extends these approaches because it is the first robot that combines the three modes of locomotion – serpentine crawling, swimming, and walking – in a single robot. Being inspired by central pattern generators (CPG) found in vertebrate spinal cords, this work demonstrates how a primitive neural circuit for swimming, like the one found in the lamprey, can be extended by phylogenetically more recent limb oscillatory centers to explain the ability of salamanders to switch between swimming and walking. It also suggests a mechanism that explains how gait transition between swimming and walking can be obtained by simply varying the level of stimulation of the brainstem, and provides a potential explanation of how salamanders control their speed and direction Part G 60.4
Biologically Inspired Robots 60.4 Bio-inspired Actuators 1403 of locomotion,by modulating the level and the asym- metry,respectively,of the drive applied to the spinal cord[60.29]. Other applications are sought within the framework of the EC biomimetic structures for locomotion in the human body (BIOLOCH)project.In the perspective of helping doctors diagnose disease by carrying tiny cam- eras through patients'bodies,a robot designed to crawl through the human gut by mimicking the wriggling mo- tion of an undersea worm has been developed by the project partners [60.30].Drawing inspiration from the way polychaetes,or paddle worms,use tiny paddles on their body segments to push through sand,mud or wa- Fig.60.10 (a)Salamandra Robotica,a robot that crawls,swims,and ter,they tackled the issue of supplying traditional forms walks Photograph by A.Herzog,courtesy Biologically Inspired of robotic locomotion that would not work in the pecu- Robotics Group,EPFL(b)A worm-inspired robot designed to crawl liar environment of the gut (Fig.60.10).The device is through intestines CPaolo Dario,Scuola Superiore Santa Anna,Pisa expected to lessen the chance of damaging a patient's in- ternal organs with a colonic endoscope,and to enhance the exploration capacities afforded by camera pills. Six Legs.In the performance energetics and dynamics of animal locomotion (PolyPEDAL)Laboratory at Berke- Walking ley,the observation that many animals self-stabilize Eight Legs.Joseph Ayers has developed a biomimetic to perturbations without a brain or its equivalent be- robot based on the American lobster at the Marine Sci- cause control algorithms are embedded in their physical ence Center of North Eastern University (Fig.60.11). structure is widely exploited.Shape deposition manu- Capitalizing on recent advances in microcontrollers, facturing has allowed engineers to tune the legs of the smart materials,and microelectronic devices,this eight- SPRAWL family of hand-sized hexapedal robots in- legged ambulatory robot is intended for autonomous spired by the cockroach that are very fast (up to five Part mine countermeasure operations in rivers,harbors, body lengths per second),robust (hip-height obstacles), and/or the littoral zone of the ocean floor.Its control and that self-stabilize to perturbations without any active architecture supports a library of action patterns and sensing [60.32].One such robot is shown on Fig.60.7. reflexes-reverse-engineered from movies of lobsters Capitalizing on previous work [60.33],a cricket-inspired behaving under the target conditions -that mediates robot,approximately 8 cm long,designed for both walk- tactile navigation,obstacle negotiation,and adaptation ing and jumping is under development at Case Western to surge. Reserve University,and is shown in Fig.60.11.McK- The robot will have the overlying motivation to ibben artificial muscles will actuate the legs,compressed navigate on a specified compass heading.When encoun- air will be generated by an onboard power plant,and tering an obstacle,it will attempt to ascertain whether a continuous-time recurrent neural network will be used it is a mine candidate or not through dedicated sensors for control.Additionally,front legs will enable climb- like an electronic nose,an acoustic hardness tester,or an ing over larger obstacles and will also be used to control active electric field perturbator.If the robot determines the pitch of the body before a jump and,therefore,aim that the obstacle is not a mine candidate,it will decide the jump for distance or height. whether to climb over the obstacle or to go around it Water strider insects are able to walk on water using information supplied by its antennal sensors and because,instead of using buoyancy-like macroscale bod- claw-like surfaces.If climbing appears to be unfeasi-ies,these very light and small creatures balance their ble,the robot will use a wall-following algorithm to weight using repulsive surface tension forces produced go around the obstacle until it can resume its predeter-by the hydrophobic microhairs that cover their legs.In mined heading.This basic scenario will apply to almost the NanoRobotics Laboratory of Carnegie Mellon Uni- all seafloor types because tactile queues from leg sen- versity,Water Strider,a miniature microrobot,walks on sors will be used to determine whether the bottom is water with legs made from hydrophobic TeflonR-coated cobble,sand or hard,and because attitude reflexes will wires and a body made of carbon fiber for minimal help with pitch and roll control [60.31]. weight(Fig.60.11).This tethered robot can successfully
Biologically Inspired Robots 60.4 Bio-inspired Actuators 1403 of locomotion, by modulating the level and the asymmetry, respectively, of the drive applied to the spinal cord [60.29]. Other applications are sought within the framework of the EC biomimetic structures for locomotion in the human body (BIOLOCH) project. In the perspective of helping doctors diagnose disease by carrying tiny cameras through patients’ bodies, a robot designed to crawl through the human gut by mimicking the wriggling motion of an undersea worm has been developed by the project partners [60.30]. Drawing inspiration from the way polychaetes, or paddle worms, use tiny paddles on their body segments to push through sand, mud or water, they tackled the issue of supplying traditional forms of robotic locomotion that would not work in the peculiar environment of the gut (Fig. 60.10). The device is expected to lessen the chance of damaging a patient’s internal organs with a colonic endoscope, and to enhance the exploration capacities afforded by camera pills. Walking Eight Legs. Joseph Ayers has developed a biomimetic robot based on the American lobster at the Marine Science Center of North Eastern University (Fig. 60.11). Capitalizing on recent advances in microcontrollers, smart materials, and microelectronic devices, this eightlegged ambulatory robot is intended for autonomous mine countermeasure operations in rivers, harbors, and/or the littoral zone of the ocean floor. Its control architecture supports a library of action patterns and reflexes – reverse-engineered from movies of lobsters behaving under the target conditions – that mediates tactile navigation, obstacle negotiation, and adaptation to surge. The robot will have the overlying motivation to navigate on a specified compass heading. When encountering an obstacle, it will attempt to ascertain whether it is a mine candidate or not through dedicated sensors like an electronic nose, an acoustic hardness tester, or an active electric field perturbator. If the robot determines that the obstacle is not a mine candidate, it will decide whether to climb over the obstacle or to go around it using information supplied by its antennal sensors and claw-like surfaces. If climbing appears to be unfeasible, the robot will use a wall-following algorithm to go around the obstacle until it can resume its predetermined heading. This basic scenario will apply to almost all seafloor types because tactile queues from leg sensors will be used to determine whether the bottom is cobble, sand or hard, and because attitude reflexes will help with pitch and roll control [60.31]. a) b) Fig. 60.10 (a) Salamandra Robotica, a robot that crawls, swims, and walks c Photograph by A.Herzog, courtesy Biologically Inspired Robotics Group, EPFL (b) A worm-inspired robot designed to crawl through intestinesc Paolo Dario, Scuola Superiore Santa Anna, Pisa Six Legs. In the performance energetics and dynamics of animal locomotion (PolyPEDAL) Laboratory at Berkeley, the observation that many animals self-stabilize to perturbations without a brain or its equivalent because control algorithms are embedded in their physical structure is widely exploited. Shape deposition manufacturing has allowed engineers to tune the legs of the SPRAWL family of hand-sized hexapedal robots inspired by the cockroach that are very fast (up to five body lengths per second), robust (hip-height obstacles), and that self-stabilize to perturbations without any active sensing [60.32]. One such robot is shown on Fig. 60.7. Capitalizing on previous work [60.33], a cricket-inspired robot, approximately 8 cm long, designed for both walking and jumping is under development at Case Western Reserve University, and is shown in Fig. 60.11. McKibben artificial muscles will actuate the legs, compressed air will be generated by an onboard power plant, and a continuous-time recurrent neural network will be used for control. Additionally, front legs will enable climbing over larger obstacles and will also be used to control the pitch of the body before a jump and, therefore, aim the jump for distance or height. Water strider insects are able to walk on water because, instead of using buoyancy-like macroscale bodies, these very light and small creatures balance their weight using repulsive surface tension forces produced by the hydrophobic microhairs that cover their legs. In the NanoRobotics Laboratory of Carnegie Mellon University, Water Strider, a miniature microrobot, walks on water with legs made from hydrophobic Teflonr -coated wires and a body made of carbon fiber for minimal weight (Fig. 60.11). This tethered robot can successfully Part G 60.4
1404 Part G Human-Centered and Life-Like Robotics b Fig.60.11 (a)The lobster robot of Northeastern University Joseph Ayers,Department of Biology and Marine Science Part G160. Center,Northeastern University.(b)The cricket robot from Case Western Reserve University CRoger D.Quinn,Mechani- cal and Aerospace Engineering,Case Western Reserve University.(c)The Water Strider robot.CMetin Sitti,NanoRobotics Lab,Carnegie Mellon University.(d)BigDog from Boston Dynamics Boston Dynamics,2007.(e)RunBot from Stirling University CTao Geng,Department of Psychology University of Stirling. move forward and backward,and can also make turns.the world's first galloping robot,developed at McGill Its maximum speed in forward motion is 2.3 cm/s.In the University [60.35].Using a single actuator per leg- future,environmental monitoring applications on dams, the hip joint providing leg rotation in the sagittal plane lakes,sea,etc.would become possible using a network and each leg having two degrees of freedom (DOF) of these robots with miniature sensors and an onboard -the actuated revolute hip DOF,and the passive lin- power source and electronics [60.34]. ear compliant leg DOF-the system exhibits passively generated bounding cycles and can stabilize itself with- Four Legs.Engineers from Boston Dynamics claim to out the need of any control action.This feature makes have developed the most advanced quadruped robot on simple open-loop control of complex running behaviors Earth for the US Army.Called BigDog,it walks,runs,such as bounding and galloping possible. and climbs on rough terrain,and carries heavy loads. Being the size of a large dog or a small mule,measur-Two Legs.Developed at Stirling University,RunBot is ing I m long and 0.7 m tall,and weighing 75 kg,BigDog probably the world's fastest biped robot for its size.Be- has trotted at 5 km/h,climbed a 35 slope,and carried ing 30cm high,it can walk at a speed of 3.5 leg-lengths a 50kg load so far.BigDog is powered by a gasoline per second,which is comparable to the fastest relative engine that drives a hydraulic actuation system.Its legs speed of human walking (Fig.60.11).This robot has are articulated like an animal's,and have compliant el-some special mechanical features,e.g.,small curved ements that absorb shock and recycle energy from one feet allowing rolling action and a properly positioned step to the next (Fig.60.11).Another quadruped with center of mass,which facilitate fast walking through amazing locomotion capabilities is Scout II,presumably exploitation of its natural dynamics.It also calls upon
1404 Part G Human-Centered and Life-Like Robotics a) b) c) d) e) Fig. 60.11 (a) The lobster robot of Northeastern University c Joseph Ayers, Department of Biology and Marine Science Center, Northeastern University. (b) The cricket robot from CaseWestern Reserve University c Roger D. Quinn, Mechanical and Aerospace Engineering, Case Western Reserve University. (c)The Water Strider robot.c Metin Sitti, NanoRobotics Lab, Carnegie Mellon University. (d) BigDog from Boston Dynamics c Boston Dynamics, 2007. (e) RunBot from Stirling University c Tao Geng, Department of Psychology University of Stirling. move forward and backward, and can also make turns. Its maximum speed in forward motion is 2.3 cm/s. In the future, environmental monitoring applications on dams, lakes, sea, etc. would become possible using a network of these robots with miniature sensors and an onboard power source and electronics [60.34]. Four Legs. Engineers from Boston Dynamics claim to have developed the most advanced quadruped robot on Earth for the US Army. Called BigDog, it walks, runs, and climbs on rough terrain, and carries heavy loads. Being the size of a large dog or a small mule, measuring 1 m long and 0.7 m tall, and weighing 75 kg, BigDog has trotted at 5 km/h, climbed a 35◦ slope, and carried a 50 kg load so far. BigDog is powered by a gasoline engine that drives a hydraulic actuation system. Its legs are articulated like an animal’s, and have compliant elements that absorb shock and recycle energy from one step to the next (Fig. 60.11). Another quadruped with amazing locomotion capabilities is Scout II, presumably the world’s first galloping robot, developed at McGill University [60.35]. Using a single actuator per leg – the hip joint providing leg rotation in the sagittal plane – and each leg having two degrees of freedom (DOF) – the actuated revolute hip DOF, and the passive linear compliant leg DOF – the system exhibits passively generated bounding cycles and can stabilize itself without the need of any control action. This feature makes simple open-loop control of complex running behaviors such as bounding and galloping possible. Two Legs. Developed at Stirling University, RunBot is probably the world’s fastest biped robot for its size. Being 30 cm high, it can walk at a speed of 3.5 leg-lengths per second, which is comparable to the fastest relative speed of human walking (Fig. 60.11). This robot has some special mechanical features, e.g., small curved feet allowing rolling action and a properly positioned center of mass, which facilitate fast walking through exploitation of its natural dynamics. It also calls upon Part G 60.4
