twinning procedure within industry 4.0

As the global production patterns change gradually into multiple varieties and small batch mode in industry 4.0, automatic production becomes not flexible enough to handle the requirement, therefore the advantages of collaborative robots are becoming increasingly apparent. The safety issues of the collaborative working environment have then also emerged into our sight. This thesis takes collaborative robot as the object of study to discuss a way of improve industrial safety with digital twin application. The purpose of the digital twin application is to achieve the prediction of the working state of the human collaborative robot. The concept of digital twin and the characteristics of human robot collaborative environment is studied, and is compared with other method to specify the target of this thesis. The detailed methodology of building and applying digital twin is designed. The methodology contains the modeling, the calculation of kinematic and dynamic states, the method of guarantee real time characteristic, and the logic design of the control. The software CATIA and Matlab is used as computer aid for the 3D modeling, numerical modeling and calculation. The real time capability is realized by simplification of the data processing process. The logic of control is designed to let the digital twin application smart enough to deal with different situations. Then a case study of Doosan Cobots is conducted to verify the methodology. Each step of building the digital twin of the human robot collaborative environment is described in detail and the performance of detecting and predicting safety issues is simulated and analyzed to draw the final conclusion.