Optimal control of the complete assembly/disassembly cycle for a mechatronics line prototype

Abstract

The aim of this paper is to define a control strategy for complete manufacturing cycle of an assembly/disassembly educational mechatronics line (EML), assisted by a complex autonomous system (CAS), a wheeled mobile robot (WMR) equipped with robotic manipulator (RM). By reversibility we mean that the line is able to perform automatic disassembly of the product detected as defect. Disassembly starts after the assembly process and after the assembled piece fails the quality test, in order to recover the parts. The CAS is used only during disassembly, to transport the parts from the disassembling locations to the storage locations. The disassembly workstation, designed and implemented as a prototype structure, functions as an integrated system in the automized control of the SMART Assembly Mechatronic Line (SAML), on which the research was made. For the control of the complete cycle assembly/disassembly mechatronic line, was identified a strategy that will be subordinated to the concepts of energetical optimization and high productivity. For this purpose, the EML served by CAS, having a specific typology, are modelled by specialized hybrid instruments belonging to Petri Nets class: Timed Petri Nets (TPN), Hybrid Petri Nets (SHPN). The results of the simulations highlight the coherence of the control structure and the absence of blockages in the dynamics of the simulated processes: assembly, disassembly, recovery of the components in warehouses. Using these models and the optimization results, a real-time control structure has been designed and implemented, allowing automated assembly and disassembly, assisted by a CAS.