Hybrid control models for flexible manufacturing systems
L. Mic, Raluca Fat, Maria Magdalena Santa, Tiberiu Stefan Letia · 2018
Flexible Manufacturing Systems (FMSs) need Hybrid Control Systems (HCSs) to solve the specified requirements. An HCS is composed of a discrete event system (DES) and a continuous Discrete Time System (DTS) that interact each other to fulfil some shared goals. The control of hybrid systems is difficult due to the complex requirements concerning asynchronous reactions to discrete events and continuous adjustment of some outputs. The main goals of the current research are to conceive models that describe the structure and the behaviour of an FMS (which by its nature is a hybrid system) and the synthesis of HCS that determines the desired behaviour with specified performances. The proposed models endow the Enhanced Time Petri Nets (ETPN) with Fuzzy Logic (FL) inference rules obtaining the Fuzzy Logic Enhanced Time Petri Net (FLETPN) models. These can be used to describe the control and controlled components of an FMS. Components that include FLETPN models are used to partition the HCS with the aim to divide the complex problem into smaller sub-problems that can be solved step by step using genetic algorithms.