Abstract:

Unreasonable resource allocation or process arrangement in the workshop production process can lead to deadlock phenomenon, resulting in the inability to continue production and greatly reducing workshop production efficiency. To address the above problems, the theories of Petri net and Banker’s algorithm were integrated to classify the deadlock formation conditions into four kinds: mutual exclusion waiting, possession waiting, cyclic waiting, and inalienability. On the basis of these four conditions, deadlocks were classified into four different manifestations, namely resource allocation deadlock, process order deadlock, collaborative object deadlock, and dynamic resource deadlock. Determining the existence of deadlocks using Banker’s algorithm, and determining the specific location of deadlocks in the workshop using the time accessibility analysis method, the deadlock recovery strategies under different forms of deadlocks were established. The proposed method was integrated into the workshop digital twin system using software such as Tina and Unity 3D, thus achieving the workshop process deadlock monitoring and prediction functions. Finally, the production process of precision stamping parts in a certain workshop was verified as an example, and the results demonstrated that the proposed method could effectively achieve real-time monitoring and efficient prediction of the production process.

Key words: production workshop, Petri nets, Banker’s algorithm, deadlocks, monitoring, deadlock recovery