keefmanhack
commented
3 years ago Ya, your right.
I had previously set the constant to 200 then we changed it to 1000 but forgot to add the 2 multiples. It's that ol' second derivative action sending that 2 down there.
I don't think this would be why the code didn't work though, because the back calculation used the same constant.
Keefer Gregoire
Senior Computer Engineer
724-712-1344
From: MikeEckels @.> Sent: Thursday, April 1, 2021 2:10 PM To: MikeEckels/StewartPlatformCommInterface @.> Cc: Gregoire, Keefer D @.>; Mention @.> Subject: [MikeEckels/StewartPlatformCommInterface] Bad formulas for calculating acceleration (#3)
I believe the equation for calculating acceleration is wrong on this line: https://github.com/MikeEckels/StewartPlatformCommInterface/blob/3a19355a26cef197171624d32f2d140c0f34c83e/Simvars/PlatformController.cs#L97 Currently the formula used is: [equation] https://camo.githubusercontent.com/b088e8ea16ffd6a30484f9f4acafa5eb01180633901457c724cfd2ed225a64e5/687474703a2f2f7777772e736369776561766572732e6f72672f74657832696d672e7068703f65713d612533442532383130303025323025323025354374696d65732532302532302532386c617374502532302d25323066697273745025323925323925323025323025354364697625323025323025323874253545322532392662633d57686974652666633d426c61636b26696d3d6a70672666733d31322666663d6172657626656469743d30 when it should be: [equation] https://camo.githubusercontent.com/a8fbe85fe2e21433532ba584b774dbed7b09c66cc564bf499b8682adb1525437/687474703a2f2f7777772e736369776561766572732e6f72672f74657832696d672e7068703f65713d612533442532383225323025354374696d65732532302532383130303025323025323025354374696d65732532302532302532386c617374502532302d25323066697273745025323925323925323925323025323025354364697625323025323025323874253545322532392662633d57686974652666633d426c61636b26696d3d6a70672666733d31322666663d6172657626656469743d30 according to this linkhttps://www.dummies.com/education/science/physics/how-to-calculate-acceleration/
What do you think @keefmanhackhttps://github.com/keefmanhack?
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I believe the equation for calculating acceleration is wrong on this line: https://github.com/MikeEckels/StewartPlatformCommInterface/blob/3a19355a26cef197171624d32f2d140c0f34c83e/Simvars/PlatformController.cs#L97 Currently the formula used is: a = (1000 (lastP - firstP)) / (t^2) when it should be: a = ((2 ((lastP - firstP)/1000)) / (t/1000)^2) [Units are m/s^2] according to this link
Then on this line https://github.com/MikeEckels/StewartPlatformCommInterface/blob/3a19355a26cef197171624d32f2d140c0f34c83e/Simvars/PlatformController.cs#L102 the equation should be NewPos = (((1/2)(a)((t/1000)^2)+(OldPos/1000))) * 1000 [Units are mm]
These new equations also take into account the conversions of mm to m and ms to s.
What do you think @keefmanhack?