139
Similarly, the equations of the external boundaries of
the CRSW of the second and third subchains are found to be
as follows:
FE2C = X2 + (-Y/2 + 13Z/2 + h + L)2 (a2 + b2)2 = 0
(4.43)
FE3Cx = X2 + (-Y/2 /3Z/2 + h + L)2 (a3 + b3)2 = 0
(4.44)
Numerical example. The given parameters are as
follows:
al = a2 = a3 = 3", b1 = b2 = b3 = 3", h = 2", L = 1"
and X = 4"
In Fig. 4.6, a cross section of the workspace of the
manipulator is plotted on the plane X = 4. It is noticed
that the complete rotatability workspace is larger than the
cross section of the workspace as shown in Fig. 4.4.
However, the cross section of the workspace of the
manipulator is still very limited.
The equations for the NRSSs determined by the
corresponding subchains can be derived in a similar way and
are therefore not described here.
The foregoing discussion applies to the case where the
given plane is perpendicular to one of the axes of the
global coordinate system. In a general case, where the
plane is inclined to the axes of the system, the gradient of