On the integrated design and development of a high speed cartesian robot

Nowadays, high speed cartesian robots are widely used as system integration of machine tools, commonly preferred to other robot architecture because of their high accuracy, reduced overall dimensions, and especially cost effectiveness and versatility. The increasing cycle speed and structural complexity of last generation machining processes imposes the design engineers to strongly improve the manipulators performances, and new requirements must absolutely be satisfied, for example the need to adopt proper safety systems and to implement different standard components to harmonically integrate with the existing machine tools. Since cartesian architecture robots are basically well developed industrial products, often already optimized during past design experiences, it becomes quite hard to find new solution and to further optimize the existing ones to realize superior performances and cost reduction. Then it becomes necessary to adopt a proper approach, on one hand able to follow the design engineers team intent during the fast evolving conceptual design stage and to help them to recognize, in a fast and effective way, the best solution to develop, on the other hand to optimize the design variant adopted. All the future users needs and design requirements must then absolutely be formalized, organized and correctly connected, in order to easily identify the task to perform, with the related priority, and their effects on all the different functionalities. In order to realize an effective robot configuration all the possible solution must be checked, as well as the choice of the motion apparatus type or the spatial placement of all the different components. Finally, once the decision of the detailed architecture took place, an intensive optimization activity becomes necessary. It is clear that a real performance improvement can be achieved only in the first design stage, where can be found design solution that can avoid future problems and simplify the structure. To really test the effectiveness of the choice adopted, a complete virtual prototype, strictly connected with the 3D CAD model, has been developed and all the possible solution verified, and compared, trough the numerical simulations, aimed to evaluate the robot different design variant final dynamical performance. The interaction between the CAD model and the virtual prototype imposed the use of third party spreadsheet, able to modify the main parameters and to easily process the simulation data results. In this paper the methodology and the solutions adopted for the design of a novel model of High Speed Cartesian Robot will be described.