To obtain the closed-form solutions of forward kinematics ofa general 6-6 Stewart mechanism
the Groebner-Sylevester hybrid approach is presented. The reduced Groebner basis under degree lexicographic ordering for the closed-form equations is evaluated withcomputer algebra. Selecting 18 Groebner basis from 65 ones
an 18×18 Sylvester matrix can be constructed
which is relatively small in size. A 40th degree univariate equation is achieved from the determinate of the matrix. The proposed algorithm operates simply and rapidly to lead to the same univariate equation via various resultants. It is verified by a numerical example that the obtained roots satisfy the original equations.
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