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NPS-SRL / SPART

Open-source modeling and control toolkit for mobile-base robotic multibody systems
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Is there a way to extract the gravity vector? #3

Closed Clyde92 closed 2 years ago

Clyde92 commented 2 years ago

I'm trying to extract the gravity vector for a control method I'm implementing that utilizes the combine Coriolis and gravity vector.

I tried constructing it using a recursive method that sums -J_i*F_i where J is returned from the Jacob function and F is the wrench acting on each link's centre of mass in the CCS, however this seemed to give me a very noisy and incorrect solution.

Would you please advise if there is a more appropriate method of doing this with the SPART toolkit?

Clyde92 commented 2 years ago

I think I may have resolved this using the natural orthogonal component matrix available through the NOC funciton.

Where the gravity matrix, is just g = N'*w and w is the 6(n+1) list of wrenches acting on each link in the chain.