Talk:Stewart platform

Removed broken link

I have removed the following link, which seems to be broken: STEWART PLATFORM — Preceding unsigned comment added by 213.183.84.169 (talk • contribs) 18:17, May 22, 2005‎

LME Hexapod link down

LME Hexapod link is down, has been down the last 6 months. I dont think it's coming back up. Sad to see it go. Here is a mirror I made of the site: http://fenn.dyndns.org/pub/www.i-way.co.uk/~storrs/lme/LMEHexapodMachine.html The archive.org copy is missing all of the .zip files. Please make mirrors of my mirror! A tarball of the website is available here: http://fenn.dyndns.org/pub/www.i-way.co.uk.tgz — Preceding unsigned comment added by 75.19.183.219 (talk • contribs) 02:00, December 11, 2006‎

Inverse Kinematics needs work

In the 'Dynamics' section, it talks about how the inverse kinematics problem has a 'unique and simple solution', but fails to either disclose this solution nor provide a link to that solution. I'm not knowledgeable in this area, but I'm quite curious about said solution. — Preceding unsigned comment added by 142.167.187.6 (talk • contribs) 20:32, December 18, 2007‎

Given a platform with 6 nodes, the location of those nodes can be changed from an arbitrary neutral position by translation and rotation. Once the spatial coordinates of the nodes in the desired position are known, you need only calculate the distance between the platform node and base node to find the required leg length. Once all legs are adjusted to the calculated length, the platform will be at the desired orientation. You can also calculate Forward kinematics iteratively by using an approximate position (often the last known). Involves the Jacobian matrix.

In return, I have a question about other ways to make a 6 DOF machine. If you look at some of the machines at http://prsco.com/ (the company I work for) they show some machines that generate the motion by altering the location of the base nodes, while the leg lengths are constant. Do these count as “Stewart Platforms”, or does “Stewart Platform” specifically move by changing leg length? — Preceding unsigned comment added by 64.140.222.126 (talk • contribs) 11:38, November 17, 2008

Incorrect chronology

Isn't the chronology of the introduction dodgy? Who published in 56 and who in 65? — Preceding unsigned comment added by 64.246.146.251 (talk • contribs) 05:34, July 16, 2008

How annoying! I just lost due to a server error a long discussion about Stewart Platform kinematics, in an attempt to partially answer the first question on this talk page. -- foxkid (talk) 00:54, 4 August 2008 (UTC)

Axial shaft bearings, or actuator shaft rotation?

I am trying to analyze the construction of the platform. It looks like slightly more than just actuators, common 2-axis universal joints, and the platforms are needed.

When the upper platform is rotated on the yaw / Z-axis in relation to the lower platform, apparently there also needs to be axial rotation bearings at either the top or bottom plate where the universal joint connects to the plate, to allow the actuator arms to twist as the plate rotates.

Though if hydraulic or pneumatic actuators are used, possibly the piston itself could rotate slightly inside the cylinder without need for axial bearings. Are the seals on hydraulic/pneumatic cylinders able to tolerate shaft rotation?

Can electromechanical actuators tolerate rotation of their shaft/body components?

-- DMahalko (talk) 06:45, 18 February 2015 (UTC)

Patent searching for Stewart Platform / 6DOF platform

Patent	Publication	Country	Description
2179605	Aug 27, 1985	GB	Motion simulator
2306429	Dec 29, 1942	USA	Device for instructing students in flying
2549916	Jul 25, 1985	FR	An active joint has compliance (Dispositif d'articulation actif a compliance)
2687491	Feb 14, 1992	FR	Vehicle simulator with a wide visual field and low moving masses (Simulateur de vehicule a grand champ visuel et faibles masses en mouvement)
2695783	Nov 30, 1954	USA	Simulated aircraft
2802635	Aug 13, 1957	USA	Flex jack
3083473	Apr 2, 1963	USA	Space flight environmental simulator
3159968	Dec 8, 1964	USA	Mounting structure for thrust devices
3288421	Mar 25, 1969	USA	Movable and rotatable top
3295224	Jan 3, 1967	USA	Motion simulator
3451146	Jun 24, 1969	USA	Mechanical motion system
3577659	May 4, 1971	USA	Motion simulator actuator joint
3597857	Aug 10, 1971	USA	Ground based flight simulating apparatus
3645011	Feb 29, 1972	USA	Motion system with three reciprocating actuators for flight simulation
3752429	Aug 14, 1973	USA	Three axis simulator
3952979	Apr 27, 1976	USA	Isolator
4066256	Jan 3, 1978	USA	Amusement ride
4164080	Aug 14, 1979	USA	Basic simulator unit
4343610	Aug 10, 1982	USA	Motion systems providing three or four degrees of freedom
4507086	Mar 26, 1985	USA	Turret shaker mechanism
4559014	Dec 17, 1985	USA	Motion limiting systems
4753596	Jun 28, 1988	USA	Motion simulator
4872363	Oct 10, 1989	USA	Electric positioning apparatus
5028180	Sep 1, 1989	USA	Six-axis machine tool
5179525	Jan 12, 1993	USA	Method and apparatus for controlling geometrically simple parallel mechanisms with distinctive connections
5366375	Nov 22, 1994	USA	Motion simulator
5401128	Mar 28, 1995	USA	In a machine for cutting a material
5403238	Apr 4, 1995	USA	Ride vehicle control system
5433608	Jul 18, 1995	USA	Vehicle simulator and method for controlling a vehicle simulator
5473990	Dec 12, 1995	USA	Ride vehicle control system
5511979	Apr 30, 1996	USA	Motion system including actuator assembly
5722897	Mar 3, 1998	USA	Sensory simulator and editor and a method of using the same
5740699	Apr 21, 1998	USA	Wrist joint which is longitudinally extendible
5931739	Aug 3, 1999	USA	Fail-safe ride simulator
6039653	Mar 21, 2000	USA	Apparatus, system and method for experiencing motion
6077078	Jun 20, 2000	USA	Motion simulator device with at least three degrees of freedom
6094180	Jul 25, 2000	USA	Gimbal-mounted virtual reality display system
6634885	Oct 21, 2003	USA	Flight simulators
7033177	Apr 25, 2006	USA	Motion simulator
7967688	Jun 28, 2011	USA	Motion simulator
8151660	Apr 10, 2012	USA	Three axes rotational motion-positioning apparatus
8403673	Mar 26, 2013	USA	Motion platform system
20150081100 A1	Mar 19, 2015	USA	Method for calibrating kinematics

-- DMahalko (talk) 10:58, 10 March 2015 (UTC)