System of Second Order ODE rewriting

Hi everyone,

I am trying to solve the following system of 2 second order coupled non linear differential equation (position and attitude of a drone):

dy1^2/dt2 = (1/M)*wRB*F*u + f (wRb depend on y1 3x1 position vector)

dy2^2/dt2 = -inv(J)*cross(dy2/dt,J*dy2/dt) + inv(J)*H*u (y2 the attitude vector, roll,pitch and yaw)

wRb is a 3x3 matrix changing each time step, F a 3x6 constant matrix, u a 6x1 vector and f a 3x1 vector.

J is a 3x3 matrix, H a 3x6 constant matrix.

I have some trouble to rewrite it correctly, here it is what I have on my file (initial condition are all at 0)

 function dX = dyn(t,x,parameters...)
 X1(:)=x
 dX1(:)=X2(:)
 dX2(1:3)=(1/M)*wRB*u + f
 dX2(4:6)=-inv(J)*cross(X2(4:6),J*X2(4:6)) + inv(J)*H*u

I just would like to know if the transformation of the 2 second order equation in first order equation is right or not ?

Thanks in advance