GUO Jian,SHI Yaoyao,HU Hao,CHEN Zhen,ZHANG Junfeng,ZHAO Pan. Adaptive Robot Scheduling Using SP–MCTS for Industrial Internet of ThingsEnabled Hybrid Flow Shop. 航空制造技术, 2021, 64(5): 42-51.
With the deep integration of industrial internet of things (IIoT) and artificial intelligence (AI) technology
automated guided vehicles (AGVs) and mobile robots have been widely used in internet of things-enabled floor shop. In view of many complex factors such as real-time dynamic changes and uncertain conditions in the workshop
the SP– MCTS (Single-player Monte-Carlo tree search algorithm) method with each job group as a subtree and real-time state as the root node is proposed to implement adaptive scheduling of workshop. The problem of robot scheduling is formulated as a Markov decision process (MDP) in which state representation
action representation
reward function
and optimal policy
are described in detail. In the real-time scheduling process
the proposed search method establishes a subtree for each job group
and only the state relationship between two adjacent groups is considered in optimization
thereby the calculation difficulty is simplified. In the subtree search process
SP–MCTS is used to search with the real-time state as the root node. At the same time
the expansion method and the pruning method are used to carry out strategy exploration and information accumulation respectively. Therefore
the deeper the real-time status node in the subtree
the faster and more accurate the optimal strategy is obtained. The case study based on a real-world shop is proven and the results validate the effectiveness and superiority of the proposed approach.