Two Dimensional (2D) Feedback Control Scheme Based on Deep Reinforcement Learning Algorithm for Nonlinear Non-repetitive Batch Processes

The repetitive/periodic/batch process is widely used in modern industrial production. However, in the context of complex batch processes with nonlinear and non-repetitive nature, designing an effective control scheme is still a critical problem in theoretical research and practical application. In terms of the excellent performance of deep reinforcement learning (DRL) in dealing with the decision-making problems for complex dynamical systems and interacting without any requirement of prior knowledge of the processes, in this paper, we propose a model-free controller design scheme by using soft actor-critic (SAC), an advanced off-policy DRL algorithm. By properly designing the state information, the neural network structure of the policy, and the reward function, the SAC agent is trained as a nonlinear two-dimensional (2D) state feedback control to achieve high tracking performance and strong robustness for the nonlinear non-repetitive batch processes. Our simulation results demonstrate the proposed control method's effectiveness and applicability, and its significant performance is superior to the conventional iterative learning control (ILC) schemes.