Stewart Platform

A Stewart platform is a type of parallel robot that incorporates six prismatic actuators, commonly hydraulic jacks. These actuators are mounted in pairs to the mechanism's base, crossing over to three mounting points on a top plate. Devices placed on the top plate can be moved in the six degrees of freedom in which it is possible for a freely-suspended body to move. These are the three linear movements x, y, z (lateral, longitudinal and vertical), and the three rotations pitch, roll, & yaw. The term "six-axis" platform is also used.

Synergistic. Because the motions are produced by a combination of movements of several of the jacks, such a device is sometimes called a synergistic motion platform, due to the synergy (mutual interaction) between the way that the jacks are programmed.

Design - Gough and Stewart. This specialised six-jack layout was first used by V E (Eric) Gough of the UK and was operational in 1954, the design later being publicised in a 1965 paper by D Stewart to the UK Institution of Mechanical Engineers. Although the short title "Stewart Platform" is now used for this jack layout, it would be fairer to Eric Gough to call it a "Gough/Stewart platform". See the more detailed references at the end of this article.

Hexapod. Because the device has six jacks, it is often also known as a hexapod (six legs). The trademarked name "hexapod" (by Geodetic Technology) was originally for Stewart platforms used in machine tools. However, the term is now used for 6-jack platforms outside of the machine tool area, since it simply means "six legs".