T. McGeer. Passive dynamic walking. Int. J. Robotics Research, 9(2):62--82, 1990.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....and variation in the ground slope. As an illustration we show stable walking gaits on varying slopes that do not exist without the total energy shaping control. 1 Introduction The notion of obtaining passive gaits, i.e. powered only by gravity, from mechanical models was pioneered by McGeer [11] and subsequently studied by several researchers, Collins [4] Garcia [5] Goswami [6] 7] Stable passive gaits were found for both planar and nonplanar bipeds on shallow downhill slopes. These passive limit tend to have narrow basins of attraction and exhibit extreme sensitivity to slope angle. ....

McGeer, T., "Passive Dynamic Walking," International Journal of Robotics Research, 9, pp. 62--82, 1990.

....was used also by Marhefka and Orin [10] Dunn and Howe [4, 5] analyzed the smooth motion, with constant body height, of a bipedal robot. During the leg impacts, the angular momentum of the entire machine about the impacting leg is conserved. The same conservation principle was used by McGeer [11, 12, 13] in 1.1.3 SCOUT LEGGED ROBOTS his analysis of a bipedal locomotion, by Smith and Berkemeier [19] in their research on quadrupedal walking, and by Sano and Furusho [18] in designing walking gaits for the BLR G2 biped. So far, the research on dynamically stable robots proved the important effect of ....

....During the impact the only external force comes from gravity, but the impact time is very short, that is DeltaT approaches zero, and therefore the angular momentum of the system with respect to the impacting toe is conserved, DeltaH O ) system = 0: 2. 6) This result was used also by McGeer [11, 13, 12] in his analysis of the rimless wheel and gravity powered wheel, and by Dunn and Howe [4, 5] in their analysis of bipedal walking. r v I m, C O . w Figure 2.5. Angular momentum of a body w.r.t a point The angular momentum of of a body about any point O (Figure 2.5) is given by 14 HO = ....

T. McGeer. Passive dynamic walking. Int. J. Robotics Research, 9(2):62--82, 1990.

....the motion of an unactuated joint. This principle was demonstrated in early work on balancing an inverted pendulum [8] and more recently in the control of running and walking [15] control of flexible beams, and control of linkages with unactuated joints [4, 21] In McGeer s walking machines [12], all joints are unactuated. Placing and assembly. When we throw an object on a table, the table has to catch it. Unfortunately, the table has no sensors, motors, or computers. It is up to us to choose the ohject s trajectory so that the intrinsic mechanics o the task do the right thing. In some ....

T. McGeer. 1990. Passive dynamic walking. Int J Robotics Research, 9(2):62-82.

....walls or pipes and other environments dicult to access for wheeled robots. Speci c examples in the literature include hyper redundant robots [13,16] the snakeboard [33,41] the G snakes and roller racer models in [26,27] sh robots [23,25] eel robots [21,37] and passive and hopping robots [18,36,43]. All this set of emerging robotic applications have special characteristics that pose new challenges in motion planning. Among them, we highlight: Underactuation. This could be owned to a design choice: nowadays low weight and fewer actuators must perform the task of former more expensive ....

McGeer T (1990) Passive dynamic walking. Int J Robotics Res 9(2):62-82.

....have developed so far. The chaotic behaviour around stable periodic solutions in simple non linear systems is probably one of the most popular topics in modern Control Theory. The main instance of such a behaviour is, of course, McGeer s passive walkers which partially utilise similar principles [6]. But unlike the McGeer s walkers we always assume the presence of oscillatory actuation in the system. Another more important issue which makes our robots differ from passive walkers is that we always start from the stable robot s position in the rest and remain stable until the system reach ....

McGeer, T.. Passive Dynamic Walking. The International Journal of Robotics Research, 9:2, 62-82, 1990.

....If such a field exists, orientation can be done without In robotics, minimalism has become increasingly influential. Raibert [41] showed that walking and running machines could be built without static stability. Erdmann and Mason [26] showed how to do dextrous manipulation without sensing. McGeer [37] built a biped, kneed walker without sensors, computers, or actuators. Canny and Goldberg [17] argue that minimalism has a long tradition in industrial manufacturing, and developed geometric algorithms for orienting parts using simple grippers and accurate, low cost light beams. Brooks [16] has ....

T. McGeer. Passive dynamic walking. Int. Journal of Robotics Research, 1990.

....dependent on initial conditions, ground conditions, etc. Wehave not attempted to perform an analysis on why the stupid walking algorithm converges to a limit cycle for the appropriate initial conditions. We only speculate that mechanisms similar to those present in McGeer s passive dynamic walker [17] are in force. In order to perform more robust walking, a speed control mechanism is necessary. This could be accomplished either through foot placement during single support or through modulating the virtual feed forward horizontal (x) force during double support. Future work will focus on using ....

Tad McGeer. Passive dynamic walking. International Journal of Robotics Research, 9(2):62--82, 1990.

....fail to take advantage of the benevolent dynamics inherent in the controlled system and risks being a control overkill. In order to gain a better understanding of the dynamics of biped locomotion we find it instructive to first explore the behavior of a simple walker model. Physical models[26][4] and theoretical and simulation results[9] 11] have demonstrated the fact that even passive biped robots with simple kinematics can successfully walk down an inclined slope in a steady gait. The motive power of such robots comes from the conversion of the robot s gravitational potential energy ....

....each involving a single degree offreedom (dof) in one of the joints. Compass gait is the first determinant of gait and it is the simplest kinematics that may exhibit a bipedal walking gait. Despite its simplicity, on a descending slope a passive compass gait robot may exhibit dynamic gait, [26] which means that its center of mass is not constrained to stay atop its foot support point. This feature is normally associated with the anthropomorphic gait and attributed to a superior control performance. The robot model, discussed in greater detail in Section 2.1, consists of two kneeless ....

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T. McGeer. Passive dynamic walking. Int. J. of Rob. Res., 9(2):62-82, 1990.

....on minimalist part feeding, and gives optimal upper In robotics, minimalism has become increasingly influential. Raibert [38] showed that walking and running machines could be built without static stability. Erdmann and Mason [24] showed how to do dextrous manipulation without sensing. McGeer [35] built a biped, kneed walker without sensors, computers, or actuators. Canny and Goldberg [16] argue that minimalism has bounds on parts positioning and orienting. Suppose we take the perspective of an architect seeking to simplify a parts feeder. MEMS arrays for programmable vector fields ....

T. McGeer. Passive dynamic walking. Int. Journal of Robotics Research, 1990.

....built such that they completely rely on their natural dynamics and the gravitational force in order to be able to operate. McGeer explored passive walking and showed that a system that has no sensors, actuators, or any sort of a brain can walk downhill, if appropriate hardware geometry is used ( [12]) Jessica Hodgins [8] has too applied passive strategies in her running biped simulations. One of the advantages to 11 these passive walkers is that it is easy to build them and also they do not require actuators, sensors, or computers in order to make them move, but these robots have limited ....

....naturally as possible without being held by an external object. Figure 2 9 shows a drawing model of the robot s leg with all the degrees of freedom. 22 Figure 2 9: Model of a leg of M2 showing all the degrees of freedoms. 23 Chapter 3 Robot s Natural Dynamics Many researchers such as McGeer [12], Goswami et al. [5] and Garcia et al. [3] have exploited natural dynamicsto make their walking machines walk passively meaning that their machines rely completely on their natural dynamics and gravitational force in order to traverse along. Powerful design of a robot can simplify the control ....

T. McGeer. Passive Dynamic Walking. International Journal of Robotics Research, 9(2):62-82, 1990.

....of the swarm. To examine this relationship, we program agents with sets of rules (a rule base) that control their actions; we then observe the resulting swarm behavior. Swarm algorithms have been applied to many varied situations: character recognition ( 21] hypothetical nanorobot control ([9]) tra#c simulation, anthropological studies ( 5] unexploded ordnance removal ( 12] predator prey population models, and many other applications. In this paper, we are interested in controlling the swarm behavior and applying swarm algorithms as a generalized problem solving strategy. 1.4 ....

....sake of creating longer ones. Our current experiments involve using a sliding scale for disbanding, the longer a super entity has existed, the more agents it must contain in order to avoid disbanding. We expect that this approach will yield fewer, longer entities. 5. 3 Tumor killing experiment In [9], Lewis and Bekey explored the control strategies of a virtual swarm of nanorobots to attack a simulated tumor. They described a uniform control strategy based on randomness, di#erentiation, recruitment, reinforcement, and knowledge propagation. The swarm of nanorobots are injected near the area ....

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T. McGeer (1990) Passive Dynamic Walking , In The International Journal of Robotics Research , volume 9(2), pages 62--82.

....to the nervous system. The biomechanics including muscles, tendons, and the complex anatomy of muscle insertions play a major role in producing smooth, efficient and robust movement seen in biological system. Researchers have demonstrated and analyzed passive walker dynamics (Collins et al. 2001; McGeer 1990) and exploited the natural dynamics of walkers to simplify control (Pratt and Pratt 1999) The interplay between the neural and physical dynamics has been explored in real robots (Kimura et al. 1999) and was also pointed out in animals by Russian physiologist Bernstein. We consider What is the ....

McGeer, T. (1990). "Passive dynamic walking." International Journal of Robotics Research, 9(2), 62-82.

.... in Embodied AI have increasingly stressed the importance of the robot body [2] and morphological parameters, such as mechanical structure and sensor and actuator placements, which greatly influence the performance of a robot [15] More significantly, work in passive dynamic walking by McGeer[14] , Collins et al. 3] and Goswami et al. 8] have shown that morphology is all important in determining the performance of passive biped walking mechanisms. However, this effect of morphology has not been systematically studied or harnessed to tune performance in the domain of active biped robot ....

T. McGeer. Passive dynamic walking. Int. J. Robotics Research, 9(2):62--82, 1990.

....number of degrees of freedom as the human (in the legs) and is capable of executing sidesteps on sloped surfaces. Figure 2.1: MIT Leg laboratory 3D Biped. 2.3 Passive dynamic walking Another class of bipedal machines are passive walkers. The first passive walkers built was probably by McGeer [9]. It could walk down a small slope without forces external to that of gravity. The mechanical structure consisted of a heavy hip, two ankles and two curved feet. The curved feet are to ensure the foot clears the ground during mid swing. After the success of the first walker he subsequently built a ....

T. McGeer. Passive dynamic walking. International Journal of Robotics Research, 9(2):62--82, 1990.

....the ground, eliminating the unwanted behaviour of the robot to turn at higher velocities. This addition allowed the robot to travel up to 50 percent faster than previous efforts had achieved. A different analytical approach examined how mechanical design contributes to robot performance. McGeer [12] showed that a correctly designed biped walker with no actuation and no control could walk down gentle slopes. His research showed that passive dynamic walking is possible 1 . The slope allowed the robot to regain through gravity energy lost though friction and impulse collisions. Garcia et al. ....

....robot was not known in advance, this estimation was used to select the Futaba S9402 servos 3 that were used as the joint actuators. An estimate of the mass distribution was obtained from measuring material samples and weighing of component parts. 3.2. 3 Proportions and mass distribution McGeer [12] demonstrated that proportions can be more important than control by showing that dynamic walking can be achieved without actuation or control. In particular, mechanical parameters such as length and mass distributions may have a greater effect on the human gait than previously imagined. ....

T. McGeer, "Passive dynamic walking," International Journal of Robotics Research, vol. 9, pp. 62--82, 1990.

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T. McGeer. Passive dynamic walking. Int. J. Robotics Research, 9(2):62--82, 1990.

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T. McGeer. Passive dynamic walking. Int. J. Robotics Research, 9(2):62--82, 1990.

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T. McGeer, "Passive dynamic walking," International Journal of Robotics Research, vol. 9, no. 2, pp. 68--82, 1990.

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T. McGeer. Passive dynamic walking. Int. J. Robotics Research, 9(2):62--82, 1990.

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T. McGeer. Passive dynamic walking. International Journal of Robotics Research, 9(2):62--82, 1990.

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T. McGeer. Passive dynamic walking. Int. J. Robotics Research, 9(2), 1990.

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McGeer. T.,, "Passive dynamic walking", Int. J. of Robotics Research, 9(2), 1990.

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McGeer, T. (1990) "Passive Dynamic Walking", International Journal of Robotics Research, Vol. 9, pp. 62--82.

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McGeer T. Passive dynamic walking. Intern J.Robot Res. 1990b; 9: 68-82.

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McGeer, T. Passive dynamic walking. International Journal of Robotics Research, Vol. 9, No., 2, 1990, pp. 62-82.

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