Mobile Robot With Robotic Arm: Development and Validation of a Digital Twin

Mobile robots coupled with robotic arms are a powerful instrument for factory automation, and they have become more and more popular in last years. Their digital twins allow to simulate the behavior in an industrial environment, increasing the capability to monitor their performance to detect failures or deviation from expected behavior. This work considers a system composed by a MiR250 mobile robot and by a UR5 anthropomorphic robot and describes the digital twin of the composed system. The digital twin is the coupling of the model of the UR5 robotic arm and that of the mobile robot. The model of the mobile robot considers a dynamic model of each wheel, to investigate the behavior of driving and caster wheels, and the model of the motors, to evaluate the expected motor torque. The digital twin of the UR5 robotic arm was tuned according to an identification methodology previously developed. An experimental campaign was carried using an Optitrack motion capture system. The results show that the model can provide reliable data to check and forecast the behavior of the system. The paper describes the complete model of the system, discusses its identification process, and shows some results obtained in the experimental campaign.