Design and implementation of distributed middleware for CRAFT remote handling system

The software system of remote handling control system (RHCS) for the comprehensive research facility for fusion technology (CRAFT) consists of multiple subsystems and various device controllers running on different hosts or servers. A high-performance CRAFT remote handling (RH) middleware (CRMW) is designed to address the high real-time requirements for task response and data transmission in this distributed scenario, as well as the scalability of the RHCS. CRMW adopts a low-coupling, high-cohesion, and component-based architectural design, comprising a component-based software development framework and a real-time communication port. The robot framework allows encapsulating devices or functional modules in the RHCS as reusable components, while the communication port provides low-latency and stable communication quality. It supports various communication modes such as publish/subscribe, server/client, and multiple transmission protocols, while also offering distributed components like remote procedure call (RPC). Corresponding experimental results demonstrate that CRMW can deliver low-latency and stable task response and data transmission, fully meeting the requirements for task execution and system management in the RHCS.