erratic_robot dynamic [closed]

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hi all,

i need to find the dynamic model of erratic robot from erratic_robot stack, because i have to modify the dynamic for my targets.

I have no idea about how to modify the dynamic, i can do that on matlab robotic toolbox. For example, in Matlab i have a function like this one:

function sys = mdlDerivatives(t,x,u, quad)

which allow me to calculate the state derivatives for the next timestep. In ROS there is something like that?