**5. Conclusions**

A visual inspection system for catenary components is proposed in this chapter. An image resolution of up to 0.5 mm/pixel is achieved, which covers almost all the components to be checked. An intelligent analysis framework is also proposed, which is used to perform automatic image detection for component defects.

In the past, the component status of catenary is inspected periodically; workers have to go on the railway lines and perform the inspection by human eyes. The infrastructure maintenance will be arranged based on the inspection results. The in-time catenary maintenance is no easy as a result of the poor inspection efficiency. Thanks to the inspection technologies and system proposed in this chapter, the inspection efficiency for component status of catenary is greatly improved, and it is of great use for the catenary maintenance. The status of catenary is well managed based on the automatic visual inspection, and the manner of catenary maintenance is improved from periodically maintenance to condition-based maintenance.
