US 12,030,176 B2 · Parallel kinematic manipulator system and control method therefor

Abstract

A parallel kinematic manipulator system having three degrees of freedom and a method of controlling and visualizing work objects using force feedback and oscillation algorithms is provided. Three co-planar linear actuators operate symmetrically and parallel to an effector arm and are pivotally connected by three magnetic disc swivel joints to a base plate. The disc swivel joints each include a convex upper and lower swivel member having two dimensional gear patterns structured into their contacting and non-sliding surfaces. A pulsed illumination source consists of an annular LED array and is synchronized to the oscillation frequencies of the system to provide visual filtering capabilities. A control unit includes a method for keeping a work object balanced by force feedback and without the need for angle sensors at the end-effector, as well as methods for rotation of work objects and control of the pulsed illumination source. Sound trap ridges are included as part of the housing to reduce system noise.

Claims20

Dependent claims

A parallel kinematic manipulator system, comprising:

at least three coplanar actuators operating substantially parallel to an effector axis and an effector extending along the effector axis;
wherein the effector having pivot connections respectively with the at least three actuators, each pivot connection having at least two degrees of freedom, whereby the effector is free to translate to any point in a three dimensional defined workspace and,
wherein at least one of the pivot connections includes a disc swivel joint, the disc swivel joint having an upper and lower swivel member sharing a common contact point and at least one of the swivel members having a convex surface facing the other swivel member, whereby the disc swivel joint is allowed to operate analogous to a universal joint serially coupled with two non-parallel prismatic links.

A control method for a robotic system including an effector movable in three dimensions such that physical contact at a single contact point with a work object is possible, wherein the single contact point being defined relative to the work object, a control unit, a work object, and at least one sensor producing signals necessary to estimate coordinates of the single contact point in three dimensional space, the control method comprising:

positioning a work object such that a single contact point is made with an effector;
positioning the work object such that its center of gravity (CG) point lies substantially on a vertical gyroscopic line above the single contact point;
inducing an oscillatory motion of the work object, such that the single contact point oscillates in a plane substantially parallel to ground;
processing the signals from the at least one sensor such that estimation of the work object state including a work object general azimuthal angle of tilt can be made for a sufficiently large chosen time window;
detecting if a work object general polar angle is consistently increasing in the work object general azimuthal angle of tilt direction for a sufficiently large chosen time window;
altering the induced oscillatory motion such that the work object general polar angle is decreasing for a sufficiently large time window, whereby the work object tendency to fall due to gravity forces is counteracted.

3 more elements

Dependencies are inferred from the claim text.

Parallel kinematic manipulator system and control method therefor

Life of this patent

Parallel kinematic manipulator system and control method therefor

Life of this patent

Abstract

Claims20