More and more shopfloors see the integration of fleets of autonomous guided vehicles (AGVs) to execute transport tasks. Previously, the control of these robot fleets was predominantly done by central controllers. This severely limits the scalability of such systems and introduces a single point of failure, to just name two disadvantages. With the increasing size of typical use cases, a trend toward the decentralization of control tasks can be observed. Additionally, many factories exhibit a special structure in their environment, resulting from the modern robot hardware that is available. Precisely, the system consists of fully connected areas and their connections. So far, this information is not utilized by typical deadlock handling strategies. This thesis introduces a hierarchical environment representation that can capture the described structure of the environment efficiently. On this basis, a hybrid deadlock prevention approach is proposed that uses multiple, independent components. For this, several novel strategies are derived which can be used to solve the problem of positioning idle robots, and their consequences on the characteristics of the system are explored. The proposed hybrid approach is then compared to a reference algorithm to evaluate its performance. Simulations are conducted in order to compare the two methods concerning the most important metrics. It is shown that the developed deadlock prevention approach outperforms a reference algorithm in terms of the system throughput, which is the key metric for this use case. This result is achieved even while subjecting the used robots to lower wear and tear, as well as lower energy usage compared to the reference algorithm because fewer unnecessary detours are made.     «

More and more shopfloors see the integration of fleets of autonomous guided vehicles (AGVs) to execute transport tasks. Previously, the control of these robot fleets was predominantly done by central controllers. This severely limits the scalability of such systems and introduces a single point of failure, to just name two disadvantages. With the increasing size of typical use cases, a trend toward the decentralization of control tasks can be observed. Additionally, many factories exhibit a...     »