Online integration of a PLC-based application and a cloud-hosted automated planner

The proposed architecture enables seamless integration between high-level decision-making, performed by the automated planner, and low-level execution, carried out by machines and equipment. This approach fosters modularity, flexibility, and adaptability in response to the short life cycles of production demands—essential characteristics of Industry 4.0 and aligned with the emerging guidelines of Industry 5.0. The solution is applicable to a wide range of industrial scenarios, such as assembly lines, robotics, automated process control, and logistics processes in which logical decisions must be synchronized with physical actions in real time, based on initial conditions obtained from sensors and executed by actuators. The implementation of a Python-based Application Programming Interface (API) is capable of generating a solution file that specifies preconditions and describes the actions required to address a customer request, using a planner written in the Planning Domain Definition Language (PDDL) within an industrial environment controlled via the Modbus TCP protocol. Physical process automation driven by symbolic planning logic requires robust and secure integration between software and industrial hardware. To ensure this integration in multithreaded environments, the system continuously monitors, in real time, the preconditions and effects of planned actions, executing commands directly on programmable logic controllers (PLCs) connected via Modbus.