METODO PER AZIONAMENTO REMOTO DI MECCANISMI E INTERFACCIA APTICA ESOSCHELETRICA BASATA SU TALE METODO

摘要

A method for actuating a mechanism adapted to impose a prefixed relative movement between said first rigid link (3) and said second rigid link (5). The mechanism comprises revolute joints and may be a parallelogram mechanism (10a, 10b), a pantograph remote centre of rotation mechanism (RCRM, 11 ), or a multiple-degrees-of-freedom mechanism (10c) thereof. The method allows reducing the torque requirements of the actuators and increasing the stiffness of the transmission, for a given required actuating torque/force, with no need of particularly cumbersome components proximate to moving parts. The method provides coaxially arranging at one or more selected revolute joint/s (37a-d, 47c-d) a number of idle pulleys (32a-d, 47a-f) which is greater than the number of degrees of freedom of the mechanism, the first of the selected revolute joint/s (37a, 47a) having preferably its rotation axis fixed with respect to the rigid link (3); the methods provides furthermore arranging an inextensible cable (33, 43) between a traction point (34, 44), e.g. a gripping point of an actuator, and a terminal point (36, 46) on the mechanism or on the second rigid link (5). By pulling the inextensible cable (33, 43) at the traction point (34, 44), a multiplied torque is produced which is the sum of singular torques produced by the inextensible cable (33, 43) at each idle pulley (32a-d, 47a-f), the multiplied torque causing a relative movement between the links (3, 5). The method provides arranging a further inextensible cable which forms contact arcs preferably symmetrically to said contact arcs about the same pulleys of the other cable, for bilaterally actuating the mechanism, i.e. causing opposite relative movements between the first and the second links (3, 5), which allows implementing such opposite limb movement as abduction/adduction of the phalanx of a finger. A hand exoskeleton that uses the method is preferably obtained by serially arranging two pantograph RCRM to implement proximal and medial phalanx and a crossed parallelogram mech. for implementing distal phalanx joints of at least a finger. In a mechanism like the one used for the cable used to actuate a more distal mechanism must cross more proximal mechanisms, which may occur in active, collaborating mode, or in a neutral mode.