A Stewart platform is a kind of parallel manipulator using an octahedral assembly of struts. A Stewart platform has six degrees of freedom (x, y, z, pitch, roll, & yaw).
Contents |
The Stewart platform was first reported in a paper by V. E. Gough in 1956. The name of Stewart was attached to this architecture because Gough's earlier work (and a photograph of his platform) were mentioned in the reviewers' remarks to a paper by D. Stewart published in 1965; in that paper, Stewart presents another hybrid design, with three legs having two motors each.
There are six independently actuated legs, where the lengths of the legs are changed to position and orient the platform. The forward kinematics problem, a system of equations which given the leg lengths, yields the position and orientation of the platform, has up to 40 solutions. However, the inverse kinematics problem (i.e. given the position and orientation of the platform, find the required leg lengths) has a unique and very simple solution.
Stewart platforms have applications in machine tool technology, crane technology, underwater research, air-to-sea rescue, flight simulation, satellite dish positioning, telescopes and orthopedic surgery.
The Low impact docking system developed by NASA uses a Stewart platform to manipulate space vehicles during the docking process.
Geodetic Technology trademarked "hexapod" for a Stewart platform in a machine tool context. However, apparently this has not stopped other machine tool manufacturers from using the term. The open source CNC software package, the Enhanced Machine Controller (EMC) [1] is capable of driving a Stewart platform using standard G-codes such as used for milling machines, etc.
James S. Albus of the National Institute of Standards and Technology (NIST) has developed a crane, known as RoboCrane, which uses the Stewart platform technology.
Dr. Charles Taylor utilized the Stewart platform to develop the Taylor Spatial Frame [2], an external fixator used in orthopedic surgery for the correction of bone deformities and treatment of complex fractures.
Eric Gough was an automotive engineer and worked at the Dunlop Tyres factory in Birmingam, England. He developed his "Universal Tyre-Testing Machine" (also called the universal rig) in the 1950s and his platform was operational by 1954. The rig was able to mechanically test tyres under combined loads. Gough died in 1972 but his testing rig continued to be used up until the late 1980s when the factory was closed down and then demolished. His rig was saved and transported to the Science Museum (London) storage facility at Wroughton near Swindon.
   | The True Origins of Parallel Robots - The True Origins of Parallel Robots |
| | National Institute of Standards and Technology - National Institute of Standards and Technology |
| | SYMETRIE - Positioning, Measurement and Motion Hexapod System - Hexapode positionnement haute précision mouvement spécifique et micropositionnement |
| | Hexapod Six-Axis Precision Micro-Positioning Systems - PI: Hexapod Products: Precision 6-Axis Stages, Robotics, Parallel Kinematics, Nanopositioning, Micropositioning; Hexapods PI Motion Control; Tripod; electrical linear actuator hexapod |
| | Low-Inertia Parallel-Kinematic Hexapods for Submicron Alignment and Handling - Low-Inertia Parallel-Kinematics Systems for Submicron Alignment and Handling |
| | the Enhanced Machine Controller (EMC) - LinuxCNC.org - Home |
| | Hexapod as Surgical Robot - PI Precision Hexapod as Surgical Robot, Operation Robot, Hexapod in Medical Application, Hexapod for Surgery |
|
|
Wikis
Quiz
Map
Search