Kinematics of General Spatial Mechanical Systems. M. Kemal Ozgoren
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(3.189)
Note that the HTM defined above has three major partitions. Its invariant trivial partition is its last row, which is
By using the preceding definitions, Eq. (3.187) can be written in the following compact and linear form, which is known as the homogeneous transformation equation.
If there are several different reference frames such as
(3.192)
As for the overall homogeneous transformation equation, it can be written as
Upon successive substitutions, the preceding equations lead to the following equation for the combined HTM.
As noticed above, the expression of the overall HTM given by Eq. (3.194) involves only matrix multiplications and thus it is much more compact and easier to compute as compared with the accumulation of the consecutive expressions given by Eqs. (3.184) and (3.185) for the rotation matrix and the bias term of the overall affine transformation expressed by Eq. 3.180.
3.9.5 Mathematical Properties of the Homogeneous Transformation Matrices
1 (a) Determinant of an HTM
Referring to Eq. (3.190), it can be shown that
(3.195)
1 (b) Inverse of an HTM
Equation (3.191) can be written in the following two ways: first by interchanging
Equations (3.196) and (3.197) imply that the inverse of
(3.198)
1 (c) Decomposition of an HTM
The overall displacement of
(3.199)
(3.200)
According to the above descriptions,
1 (i) First translation and then rotation:(3.201)
2 (ii) First rotation and then translation:(3.202)
The factorizations described above suggest the following definitions of pure rotational and translational displacements and the associated homogeneous transformation matrices.
1 (d) HTM of a Pure Rotation
A pure rotational displacement of