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1. (WO1991017536) METHOD AND APPARATUS FOR CONTROLLING GEOMETRICALLY SIMPLE PARALLEL MECHANISMS WITH DISTINCT CONNECTIONS
Latest bibliographic data on file with the International Bureau

Pub. No.: WO/1991/017536 International Application No.: PCT/US1991/002983
Publication Date: 14.11.1991 International Filing Date: 01.05.1991
Chapter 2 Demand Filed: 22.11.1991
IPC:
B23Q 1/54 (2006.01) ,B25J 9/16 (2006.01) ,B25J 17/02 (2006.01) ,G09B 9/14 (2006.01)
B PERFORMING OPERATIONS; TRANSPORTING
23
MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
Q
DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL, CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
1
Members which are comprised in the general build-up of a form of machine, particularly relatively large fixed members
25
Movable or adjustable work or tool supports
44
using particular mechanisms
50
with rotating pairs only
54
two rotating pairs only
B PERFORMING OPERATIONS; TRANSPORTING
25
HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; HANDLES FOR HAND IMPLEMENTS; WORKSHOP EQUIPMENT; MANIPULATORS
J
MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
9
Programme-controlled manipulators
16
Programme controls
B PERFORMING OPERATIONS; TRANSPORTING
25
HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; HANDLES FOR HAND IMPLEMENTS; WORKSHOP EQUIPMENT; MANIPULATORS
J
MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
17
Joints
02
Wrist joints
G PHYSICS
09
EDUCATING; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
B
EDUCATIONAL OR DEMONSTRATION APPLIANCES; APPLIANCES FOR TEACHING, OR COMMUNICATING WITH, THE BLIND, DEAF OR MUTE; MODELS; PLANETARIA; GLOBES; MAPS; DIAGRAMS
9
Simulators for teaching or training purposes
02
for teaching control of vehicles or other craft
08
for teaching control of aircraft, e.g. Link trainer
12
Motion systems for aircraft simulators
14
controlled by fluid actuated piston or cylinder ram
Applicants:
UNIVERSITY OF FLORIDA [US/US]; 223 Grinter Hall Division of Sponsored Research Gainesville, FL 32611, US
Inventors:
GRIFFIS, Michael, W.; US
DUFFY, Joseph; US
Agent:
LAND, John ; Spensley Horn Jubas & Lubitz 1880 Century Park East Fifth Floor Los Angeles, CA 90067, US
KONRAD, William, K. ; Spensley Horn Jubas & Lubitz 1880 Century Park East Fifth Floor Los Angeles, CA 90067, US
Priority Data:
517,37101.05.1990US
Title (EN) METHOD AND APPARATUS FOR CONTROLLING GEOMETRICALLY SIMPLE PARALLEL MECHANISMS WITH DISTINCT CONNECTIONS
(FR) PROCEDE ET APPAREIL PERMETTANT DE COMMANDER DES MECANISMES PARALLELES GEOMETRIQUEMENT SIMPLES COMPRENANT DES CONNEXIONS DISTINCTES
Abstract:
(EN) A system, method and apparatus for controlling, via a closed-form forward displacement computation, the position and orientation of a movable platform of a parallel mechanism. A movable platform is supported above a base platform by a plurality of parallel support legs such as linear actuators. The dimensions of the base platform and the movable platform, as well as the lengths of the support legs, are provided to a control system. The control system is operative to compute at least one closed-form forward displacement solution (51) of the geometry of polyhedron (an octahedron for the disclosed embodiments) formed by the movable platform, the base platform, and the support legs. The control system determines a final position and orientation of the movable platform by eliminating imaginary roots of the closed-form solutions and roots which would result in discontinuous paths of travel for the movable platform. A novel special 6-6 parallel mechanism (Fig. 12) is also disclosed. The control system is suitable for controlling known 3-3 or 6-3 Stewart platforms in a novel manner, as well as controlling the novel special 6-6 parallel mechanism. The special 6-6 parallel mechanism is distinguished from a general 6-6 by the fact that it is geometrically reducible to an octahedron, and therefore it has a simple geometry, even though its legs possess distinct connections. Also disclosed is a method for reducing the novel special 6-6 parallel mechanism to a Stewart platform equivalent, which is then controlled by the disclosed closed-form forward displacement control system.
(FR) Système, procédé et appareil servant à commander, via un calcul de déplacement vers l'avant à commande en boucle fermée, la position et l'orientation de la plate-forme mobile d'un mécanisme parallèle. Ladite plate-forme mobile est supportée au-dessus d'une plate-forme de base par une pluralité de bras parallèles de support tels que des vérins à déplacement linéaire. Les dimensions de la plate-forme de base et de la plate-forme mobile, ainsi que les longueurs des bras de support, sont fournies à un système de commande qui calcule au moins une solution (51) de déplacement vers l'avant à commande en boucle fermée, de la géométrie du polyèdre (un octaèdre pour les modes d'exécution décrits) formé par la plate-forme mobile, la plate-forme de base, et les bras de support. Le système de commande détermine la position et l'orientation finales de la plate-forme mobile en éliminant les racines imaginaires des solutions en boucle fermée et les racines qui produiraient des trajectoires discontinues pour la plate-forme mobile. Un nouveau mécanisme (Fig. 12) spécial parallèle 6-6 est également décrit. Le système de commande permet de commander, d'une nouvelle manière, des plate-formes Stewart connues 3-3 ou 6-3, il permet également de commander le nouveau mécanisme parallèle 6-6 particulier. Ce mécanisme parallèle 6-6 particulier se distingue d'un mécanisme 6-6 courant par le fait qu'il peut se réduire géométriquement à un octaèdre, et qu'il possède alors une géométrie simple, même si ses bras comprennent des connexions distinctes. L'invention concerne également un procédé de réduction du nouveau mécanisme parallèle 6-6 particulier en une plate-forme Stewart équivalente, qui est alors commandée par le système de commande de déplacement vers l'avant à commande en boucle fermée, décrit ci-dessus.
Designated States: CA, JP, KR
European Patent Office (AT, BE, CH, DE, DK, ES, FR, GB, GR, IT, LU, NL, SE)
Publication Language: English (EN)
Filing Language: English (EN)
Also published as:
EP0528959JPH05506948CA2080822KR1019930700929