where VGx and VGy are the velocity components in the
X and Y directions, lr is the CG shift relative to the X
axis, e is the CG shift relative to the Y axis, w is the
distance between centers of the two rear wheels, vL and
vR are the linear velocities of the left and right wheels.
In the case of the static manipulator, lr and e are
constant values.
From the Lagrange equation of the second type, the
dynamics equation of the system can be defined by