Precise positioning in a robotized laser-cutting machine allowed by a three-V-shaped-groove kinematic coupling: a feasibility study

Devices known as kinematic couplings offer accurate, repeatable, and stiff connections between two parts. They are characterized by point contacts and enable great repeatability with errors less than 1 micron, in contrast to conventional coupling systems like alignment pins or those based on elastic deformation. In this study, a robotized laser-cutting machine is equipped with a three-groove kinematic coupling design to increase the precision of workpiece placement. Given the application’s requirements, a preliminary design of the coupling is defined. An analytical approach is provided for calculating stresses and deflections at the locations where balls and grooves make contact, and it is then utilized to calculate positioning errors caused by the mechanical structure’s elastic deformation under various loading conditions. The outcomes of the simulations are finally discussed and highlight the efficacy of the solution tested.