Clone of LAJPE energy Wilberforce
박재성
k=31.8 N/m, 
m=0.493 kg
I=0.000102 kg m^2  
D=0.0066 N m /rad^2
ε = 0.0244 N/rad
b=0.0042 N s/m,  
β =0.00000087 N m s /rad^2
z0=0.0245 m
α0=0rad