Patent ID: 8452453
Filing Date: 2013-05-28
Classification: B25J,Y10T

Abstract:
1. A robot comprising: a base section; at least three motors set on the base section; at least three take-ups mounted on the motors respectively; a support set on a surface of the base section and having an axial centerline perpendicular to the surface of the base section; a Cardan joint mounted on an upper end of the support and including a first shaft and a second shaft, the first shaft being in contact with the support; a movable plate mounted on the Cardan joint, the second shaft of the Cardan joint being in contact with the movable plate; at least three universal couplings set on a bottom portion of the movable plate; wires into which nonlinear springs coupling the take-ups and the universal couplings in one-to-one correspondence to each other are incorporated; an output shaft fixed to an upper surface of the movable plate and having an axial centerline perpendicular to the upper surface of the movable plate; a control device configured to control tension on the basis of a tension command for each of the wires and a tension signal for each of the wires, configured to generate the tension command for each of the wires on the basis of a target command for an attitude angle, a target command for rigidity, and a rotation angle signal for each of the motors, and configured to control an attitude angle and rigidity of the robot, the control device comprising: a fixed Cartesian coordinate system defined on the base section and comprising: a movable Cartesian coordinate system defined on the movable plate to be movable with the movable plate and comprising: wherein the motors are arranged so that one of the take-ups is present on a negative side of the x-axis and at least two of the take-ups are respectively present in a first quadrant and a fourth quadrant of an xoy coordinate system defined by the x-axis and the y-axis, the universal couplings being arranged so that phases in an x′o′y′ coordinate system defined by the x′-axis and the y′-axis reach the same values as respective phases of the take-ups in the xoy coordinate system, the take-ups and the universal couplings being coupled in the same phases of the fixed and movable Cartesian coordinate systems respectively in one-to-one correspondence to each other with the wires.