A novel concentric multilink spherical joint with parallel robotics applications

A new spherical joint mechanism which is well suited to parallel robotics is presented. The concentric multilink spherical (CMS) joint allows two or more struts to be connected together such that they rotate about a single point. This joint can replace the traditional ball or universal (Hooke) joints in Stewart platforms, variable geometry truss manipulators, and other parallel robots. The TETRA2 robot consists of five nodes and six actuated struts. It provides a range of motion of 1m/spl times/0.5m/spl times/0.5m and has lifted a payload of 10 kg at full lateral extension. Simulation of a 48 struct walking robot illustrates the use of CMS joints to design more complex structures. The simulation also demonstrates new algorithms for parallel robot control.< >