How can i adjust the parameters of an orbit in simmechanics ?

Hello, I would like to model the orbit of a body around the earth with the 6 parameters (a,e,i,Ω,ω,M) in simmechanics.

I can choose the parameters i,Ω and ω with Rigid Transform blocks but i don't know how to adjust the semi major axis a and the eccentricity e because in simmechanics, the simulation begins automatically at the aphelion of the orbit. So the only parameters I can choose are the radius of the orbit and the velocity at the aphelion.

Do you know how I can start the simulation at another point of the orbit and how can I choose a and e ? Thank you for your answers !

Answer 1

[Steve Miller]

The velocity of the body can be specified within the 6-DOF Joint block. You need to carefully ensure that the positions of your bodies and initial speeds are consistent with the orbit you want the object to follow.

Be sure to use the Gravitational Force block, added in R2014a.

This documentation page might help you explore the options for specifying the force.

https://www.mathworks.com/help/sm/ug/gravity.html

--Steve