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Abstract:
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Abstract : Humanoid robots (HRs) research and development have been increasing in the world due to motion versatility of such robots and also due to the high degree of spatial and environmental adaptability provided by th mimicking of the human body. Furthermore, in a future not so far away, HRs may become protable products when inserted into the human social and dynamic environment. By resembling the human kinematics, these robotic systems are composed of one mobile and rigid base link, from which four independent and serial kinematic chains mimicking the human limbs depart. Although HRs are capable of performing a great set of human-like motions, this mimicry generates complex robotic systems. Nevertheless, due to the many ways through which HRs are able to interact with the environment and with themselves, and also given a multi-limb kinematic chain detached from any inertial reference frame, these robots can be dened by dierent mechanisms. In this way, each dierent mechanism describes a single HR accordingly to dierent kinematic and static scenarios, dening mobile robots with structure-varying kinematic chains. Multiple contacts with the environment, arbitrary formation of passive couplings, a mobile and multi-limb kinematic structure may also become issues concerning the modeling of HRs. Such issues may increase the complexity of both the kinematic and the static models, depending on how the modeling of HRs are approached. Thus, this study proposes a such new kinetostatic modeling technique for HRs that these not so good features earlier addressed, e.g., the structure-varying kinematic chains, multiple contacts with the environment, arbitrary formation of passive couplings, and a mobile and multi-limb kinematic structures cease to be issues. The kinetostatic model rises from the combination between both the kinematic and the static models. This insight is based on the marionette doll, so that both the kinematic and the static models become characterized, individually, by single parallel kinematic chains whose structures do not vary. This marionette doll proposal is based on the straightforward relation between the strings of the doll's mechanism and the Assur's virtual chains, combined with screw theory and Davies' method. |
