Cabled differential for cable controlled joint
AssigneeThe Board of Trustees of the Leland Stanford Junior University
InventorsJ Kenneth. Salisbury, JR., Alex Nathan Kahn
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Abstract
Cable-actuated differential enabling N degrees of freedom provided by a plurality of pulleys and at least N+1 tensioning cables. The cable-actuated differential increases a dynamic force range by minimizing co-activation of the tensioning cables at any operating point. A cable-actuated differential having three cables provides motor based control of a 2 DOF joint that can be applied to robots or teleoperation. A cable-actuated mechanical differential having opposing bevel gears and a middle bevel gear meshed with the opposing gear allows an output connector to controllably and independently rotate about the x axis or y axis via three operational modes without backlash.
Claims21
1) A cable-actuated differential having N degrees of freedom, comprising:
- a) a plurality of actuation elements;
- b) a plurality of pulleys, each pulley having one or more tensioning cables independently attached along the perimeter of the respective pulley, wherein the number of tensioning cables is at least N+1, wherein N is equal to at least 1;
- and
- c) mounting structure that allows rotation of the pulleys, wherein the tensioning cables are co-activated by the actuation elements by simultaneously applying minimum tension without causing slack.
12) A system having two N+1 cable-actuated differentials interconnected to each other by cables connected to a first pulley and a second pulley of each differential, the two cable-actuated differentials each rotate in a coordinated manner about their respective x-axes.
15) A method for operating a cable-actuated differential over N degrees of freedom having at least N+1 cables under tension, wherein the cable-actuated differential comprises a plurality of pulleys, each having one or more of the cables attached, wherein tension is independently activated on each cable without slack such that co-activation between the cables is minimized, wherein co-activation of the tensioning cables is minimized by minimizing the amount of tension applied simultaneously to the cables without causing slack.
Dependencies are inferred from the claim text.