This invention discloses a hierarchical dynamic scheduling method based on the policy optimization DDQN
algorithm for solving the dynamic scheduling problem of a reentrant
hybrid pipelined workshop with
batch processing machines. First, the objective function and constraints of the scheduling problem are determined. Then, by introducing a self-attention mechanism, a hierarchical
structure based on DDQN is proposed, constructing two agents: a batching agent and a scheduling agent, to solve the batching and scheduling subproblems respectively. Furthermore, to address the multi-stage
batch processing and reentrant scheduling characteristics of the problem, a Markov
decision process considering the characteristics of these two agents is designed, including state, action, and reward. Further, an
action selection strategy based on masking combined with an ε-greedy strategy and a soft-start target network update strategy are proposed to improve efficiency and generalization ability. This invention demonstrates significant effectiveness in solving the dynamic scheduling problem of a reentrant
hybrid pipelined workshop with
batch processing machines.