I am having a hard time linearizing the equation below of a non-linear time invariant MIMO system
$$m \cdot y_1''+F_m = Fu11−m \cdot g$$ (y1''=second derivative)
$$m \cdot y_2''− F_m = F_{u22} − m \cdot g$$ (y2''=second derivative)
where Fm= 65673.828125.(It is an equation. I have used the given values to solve it)
$$F_{u11} = \frac{u_1}{a(y_1+b)^4}$$ $$F_{u22}= \frac{u_2}{a(-y_2+b)^4}$$
The other model parameters are to be selected as: N=4, m=120 (g) , a=1.65, b=6.2, c=2.69, and d=4.2.
u1,u2 are the control inputs (related to coil currents),
a,b are constants,
𝑦1,𝑦2 are the positions of magnet 1 and magnet 2 respectively.
I have tried multiple times and got different answers each time.