A closed-loop model of a multi-station and multi-product manufacturing system using bond graphs and hybrid controllers

Production plans and production schedules are fundamentally dynamic and may be disturbed by several events. In the manufacturing research domain, however, dynamic models for scheduling and production control usually receive less attention as static models. In this paper, a bond graph model for depicting a multi-product production system with job shop configuration is proposed. A case study based on a real production system is presented to illustrate the modeling process. The state model derived from the pictorial representation (i.e., derived from the bond graphs) is simulated, in order to observe the dynamic response of the system. Also, a hybrid proportional controller (HPC) and a hybrid adaptive proportional controller (HAPC) are proposed. In this sense, this research extends the findings of a previous work reported in the literature, in which constant and proportional controllers were tested. The results demonstrated that the HAPC and the HPC outperforms the mentioned controllers, and that the bond graphs are a viable methodology to represent and study the dynamics of manufacturing systems. This approach is innovative since no other closed-loop model based on bond graphs for multiple products has been previously reported in the literature, nor its combination with a hybrid adaptive controller.