Modular and automatically configurable robot kinematics

In Robotics, the late "rediscovering" of the Screw Theory as an alternative way to describe the behaviour of rigid bodies in Mechanics, together with Lie Algebra transformations applied to resulting Kinematics equations has opened a new stream of applied research for complex robotic mechanisms and multi-axes machines with parallel kinematic architecture (PKM). The increased computational power commonly available nowadays allows for an implementation of very effective and fast-performing kinematic algorithms derived from the theory. Based on the latest achievements in this field, SimX R&D team has developed a revolutionary approach for modelling and simulating any robot device with complex, multi-branched kinematic structures. The method can be used for an automatic synthesis of (forward and inverse) kinematics of tree-type structures. This means that equations describing the motion can be straightforwardly derived by the geometrical description of the mechanism, without the need for designers to use lengthy and error-prone techniques based on the traditional Denavit-Hartenberg approach.

The method has been proved very fast and reliable, so much so that it is suitable for real-time control systems as well.

A more generalized formulation of the algorithm is also applicable to non-pure tree-type structures (i.e. structures with coupled links in different branches). Such a configuration is present in the parallel kinematic machine VERNE, designed and built by Fatronik. The algorithm has been tested using Visual Component simulation software and a CAD model of VERNE provided by CNRS-IRCCyN under the EU 6th Framework project NEXT ("NEXT generation production systems").