Integrated fault-tolerant control of assembly and automated guided vehicle-based transportation layers

ABSTRACT

The paper concerns the digital twin design and fault-tolerant control of a production system. The real laboratory system under consideration consists of two subsystems: an assembly part and an automated guided vehicle transportation one. The proposed approach focuses, simultaneously, on both concurrency and synchronization problems as they are inevitable in such a kind of modern systems. The research contribution deals with the development of an analytical description of both an assembly system and a multiple automated guided vehicles transportation layer along with algorithms that are able to determine an optimum sequence of starting individual operations. Subsequently, diagnostics and fault-tolerant control schemes are elaborated and applied to the two-layer system being investigated. The core advantage of the proposed approach is that it can compensate or eliminate the impact of some faults, e.g. delays occurring in the assembly unit or reduced velocities of transportation means. This makes it possible to keep the desired schedule as far as possible. The paper concludes with a series of illustrative use cases and comparisons which exhibit the performance of the novel approach in both cases, i.e. faulty and fault-free.

KEYWORDS:

• Fault-tolerant control
• assembly system
• automated guided vehicles system
• digital twin
• concurrency
• synchronization
• predictive control

Acknowledgements

The work was supported by the National Science Centre of Poland under Grant: UMO-2017/27/B/ST7/00620.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1. The system is located in the laboratory of ‘Process Automation and Visualization’ of the Institute of Control and Computation Engineering, University of Zielona Góra.

Additional information

Funding

This work was supported by the Narodowe Centrum Nauki [UMO-2017/27/B/ST7/00620].