Contact System Method for the Precise Interaction Between Cobots and Mobile Robots in Smart Manufacturing

The advent of smart manufacturing (SM) has led to the creation of collaborative environments with cyber-physical systems (CPS) that generate added value. However, the performance of combined industrial operations between mobile CPS such as autonomous mobile robots (AMRs) and collaborative robots (cobots) is hampered by the high uncertainty between their relative spatial locations and the existence of heterogeneous communication protocols that create a barrier to their integration into production processes. For this reason, a novel contact system method (CSM) is proposed to determine the position of the AMR without the need for any additional hardware making use of an architecture that facilitates efficient communication between AMRs and cobots. For this purpose, a mathematical model has been defined to characterize the position of a spatial object with six degrees of freedom in order to calculate the deviation between the AMR and the cobot base. The proposed method has also been evaluated by quantifying the position and orientation error before and after applying the CSM. The effectiveness of the CSM method has been assessed in a real application case based on the feasibility of performing an assembly operation between a bearing and different shafts. The results show a significant improvement of 96.2% in positional accuracy and 85.4% in orientation compared to AMR accuracy. In addition, a 92.5% success rate was achieved in the assembly operation analyzed between a bearing and a shaft of the same diameter. Furthermore, the proposed architecture has enabled the coordination between the cobot and the AMR by automating the processes. Therefore, this work contributes to the field of SM by proposing a practical solution to the challenges of generating added value through the creation of collaborative environments with CPS.