Wireless communication empowers online scheduling of partially-observable transportation multi-robot systems in a smart factory
Organizations: National Engineering Research Center of Mobile Network Technologies, Beijing University of Posts and Telecommunications, Beijing 100876, China · Department of Electrical Engineering, University of South Florida, Tampa, FL 33620 USA · School of Information and Communication Engineering, Beijing University of Posts and Telecommunications, Beijing 100876, China
Abstract
Achieving agile and reconfigurable production flows in smart factories depends on online multi-robot task assignment (MRTA), which requires online collision-free and congestion-free route scheduling of transportation multi-robot systems (T-MRS), e.g., collaborative automatic guided vehicles (AGVs). Due to the real-time operational requirements and dynamic interactions between T-MRS and production MRS, online scheduling under partial observability in dynamic factory environments remains a significant and under-explored challenge. This paper proposes a novel communication-enabled online scheduling framework that explicitly couples wireless machine-to-machine (M2M) networking with route scheduling, enabling AGVs to exchange intention information, e.g., planned routes, to overcome partial observations and assist complex computation of online scheduling. Specifically, we determine intelligent AGVs' intention and sensor data as new M2M traffic and tailor the retransmission-free multi-link transmission networking to meet real-time operation demands. This scheduling-oriented networking is then integrated with a simulated annealing-based MRTA scheme and a congestion-aware A*-based route scheduling method. The integrated communication and scheduling scheme allows AGVs to dynamically adjust collision-free and congestion-free routes with reduced computational overhead. Numerical experiments shows the impacts from wireless communication on the performance of T-MRS and suggest that the proposed integrated scheme significantly enhances scheduling efficiency compared to other baselines, even under high AGV load conditions and limited channel resources. Moreover, the results reveal that the scheduling-oriented wireless M2M communication design fundamentally differs from human-to-human communications, implying new technological opportunities in a wireless networked smart factory.
Figures & tables
| Notation | Definition | Notation | Definition |
|---|---|---|---|
| The set of AGVs | , | Task routes, and navigation routes of AGV | |
| , , | The number of available channels, selected channels, and communication interval | B | Decision matrix of MRTA |
| , , , | Local partial observation, additional observation, enhanced fusion observation, and global state | Makespan based on local observations | |
| , , , , , | Task nodes for pick-up and delivery, quantity of production at task nodes, task’s due time, task’s priority | the number of new tasks at time | |
| Reach time of AGV at task node | Route decision matrix | ||
| waiting time of AGV at task node | preparation time at task node |