Mechatronic system desing of a cake decoration robotic module using a SCARA manipulator

This article deals with the mechatronic system design of a robotic cake decoration system, following the V-methodology for the design of mechatronic systems. This methodology was selected because it allows for a holistic approach for the design of mechatronic systems, by feeding back information in all the steps of the design process. The component level step of the design process was carried out using a CAD software to get dimensions and to specify the distribution of the system components. With these dimensions and the material selected, a structural analysis was performed using COMSOL Multiphysics ®. This analysis enabled the determination of the critical points of the components, which leaded to the corresponding adjustments. The mathematical modeling for each part of the system indicated that only the manipulator modeling was needed to improve the performance of the controllers. The model of the manipulator was derived by means of a method for Open-Chain manipulators, which takes into account the viscous friction and the inertia tensors obtained from the CAD model. The control strategy selected was a LQG controller, since classical controller, such as a PID controller, cannot be tuned properly for the nonlinear model. After implementing the controller with the nonlinear model, and acquiring data about the manual cake decoration process, it was demonstrated that the newly developed robotic system reduces the cake decoration process time by 24.5% while increasing the accuracy of the pattern drawing process on the cakes.