Structural Analysis of Spatial Mechanisms

The paper briefly presents how structural analysis is performed on spatial mechanisms, presenting a practical application in the mechatronics of parallel robots, especially in Steward platforms. Structural analysis always helps to better understand the phenomena and especially the way the mechanisms are made. At spatial mechanisms the problems are a little more complex than those raised by plane mechanisms. For this reason, the present paper tries to fill a gap in the field, especially as very few specialists in the theory of mechanisms of robots and machines still work today such structures on the basis of the theoretical knowledge, the modalities and working methods being approached being the most often based on approximate calculations, empirical formulas, or simply on experimental findings, woven with computerized theoretical modeling, but lacking in the essence of the underlying theory that is no longer so well-known. The structure and geometry of the mechanisms represent basically the basic elements that need to be studied primarily when we want to analyze such a mechanism already built and especially when we want to synthesize a new one.