A Chain-Type Magnetic Wheeled Robot for In-Situ Inspection of Integrated Pipeline-Valve-Vessel Systems

Integrated pipeline-valve-vessel systems are essential in industrial processes but require periodic disassembly for inspection under extreme conditions. Robotic inspection offers an economical and efficient alternative to manual disassembly. However, existing robots are limited to inspecting pipelines or vessels separately. Continuous traversal through small-to-medium diameter pipelines (80–150 mm), valves, and into vessels remains challenging due to irregular and confined chambered structure. To overcome this limitation, we propose a chain-type magnetic wheeled robot featuring two key innovations: 1) the integration of a serial gear chain (SGC) with magnetic adhesion mechanism ensures the robot’s adaptability to irregular surfaces, reducing force-control dependency during complex valve navigation. Leveraging this characteristic, a distributed dual-end drive configuration within the SGC addresses power insufficiency caused by the robot’s suspension in the hollow regions and 2) the traditional force-angle stability margin is modified to serve as a criterion for tipover instability. Based on this, a predictive instability control framework is developed, integrating offline-computed posture thresholds with real-time attitude monitoring to enhance motion stability. Experimental results demonstrate that the robot achieves robust, stable traversal, and nondismantling inspection across pipelines, valves, and vessels without disassembly. This work provides valuable insights for industries, such as nuclear power and chemical engineering.