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