Interactive robot joint design, analysis and prototyping

NASA´s Johnson Space Center has developed a general geometric model of a manipulator joint that allows for the interactive design and analysis of robot prototypes. The interactive design software analyzes joint geometries for various performance issues, and has been connected to a Stereolithography Apparatus (SLA) for the rapid production of full scale mechanism models. The software, called Module Maker, uses variational geometry to connect the joint model´s 36 independent, geometric variables with over 100 dependent values that define the solids of a general 2 degree of freedom joint. A user can interactively “stretch” and edit the joint´s structure, with a 3D rendering that updates in real time, while displaying numeric values for review. Analysis routines developed to support the interactive design process include a general evaluation of the joint´s new range of motion, weight, moments of inertia, centroids, heat transfer coefficients and a calculation of the joint´s Denavit-Hartenberg (DH) parameters. The final step in the design cycle is to prototype the module elements using an SLA that make full scale, polyurethane components