Moment of inertia tensor in simple_robot

[yf291115925]

'create_simple_robot.m':

Ix = 1/12 * L(1).m*(3*link_radius.^2+link_length.^2);
Iy = Ix;
Iz = L(1).m*link_radius.^2/2;

We can get the second moments from https://en.wikipedia.org/wiki/List_of_moments_of_inertia. But we should pay attention to the axes !
According to <Robotics, Vision and Control> p193, "six second moments which represent the inertia of the link about the COM but with respect to axes aligned with the link frame {j},".
Z-axis of the link frame {j} is not aligned with frame {COM} of a normal cylinder.
So the corret second moments should be:

Ix = L(1).m*link_radius.^2/2;
Iy = 1/12 * L(1).m*(3*link_radius.^2+link_length.^2);
Iz = Iy;