Automated pantograph dynamic testing and defect detection

• A novel robotic pantograph testing system has been developed. • The systems can detect and diagnose a wide range of failure modes. • Measuring contact torques as well as force, significantly improves defect diagnosis. • Simple post processing of contact parameters can effectively diagnose failures. Pantographs are a key component for electric trains, responsible for collecting electrical current from the overhead lines. Maintaining pantographs in good working order is key to efficient current collection, whilst avoiding service disruption and managing safety risks. This work proposes a novel robotic system for testing pantographs. Previous studies have conducted initial investigations into automated pantograph testing, typically focusing on a small number of failure modes. There is also a range of pantograph (not automated) test methods defined in EN50206, which can identify faulty pantographs but not diagnose specific faults. The proposed test assesses contact torques as well as contact forces when raising and lowering a pantograph through its working range. Assessment of contact torques proved to be essential to identify some failure modes. Failures in the pantograph frame and joint, dampers, head suspension and air supply are considered. Test parameters, which are post processed from measured results are defined, and testing confirms that a combination of parameters can effectively diagnose all failure modes considered. The method gives a fast assessment of pantograph condition in an industrial train maintenance environment.