A coordinates method for the forward displacement analysis of in-parallel mechanisms

We present a new method called Coordinates Method for describing the position and orientation of the top platform of In-Parallel Mechanism (IPM). Because there is no trigonometric function in the description, this method is useful in solving the very difficult Forward Displacement Analysis (FDA) of general IPM. The fundamental equations for IPM are established as 18 polynomials with 18 unknown variables under degree 2. Then it was reduced to 10 polynomials with 10 unknown variables under degree2. This method were verified gy numerical example with Mathematica, and it takes only 0. 3 second. The result is a shortcut to get the closed form FDA of general IPM, which is a very difficult problem in the world for ten years.