Mitsuo Aboshi

Current collection characteristics and improvement methods of high-tension overhead catenary systems

With increasing speeds on electric railways, overhead catenary systems on narrow-gauge lines have been improved by increasing messenger wire tension. However, the contact loss ratio of the pantograph is comparatively high in heavy-simple or feeder-messenger wire-type overhead catenary systems. These catenaries have higher tension of the messenger wire. In order to investigate the causes of contact loss and to work out effective improvement methods, laboratory and field tests have been carried out. From the results thereof, it is confirmed that the contact force fluctuation is influenced by the wave reflection factor at the hanger, and a hanger which has a spring mechanism is found to effectively improve it. It is expected that rubber damping hangers or friction damping hangers will reduce contact loss of the pantograph and wear of the contact wire.

Variable contact force control based on reaction force control with adjustment ratio

This paper proposes a variable interactive force control method between a motion control system and the real environment. The proposed method is based on the observer techniques both of a disturbance observer and a reaction force observer. Then, a reaction force control without force sensors is realized. The flexible design of the contact force with the environment can be achieved by the implemented adjustment ratio to the reaction force control system. Some real experimental results are shown to verify the validity of the proposed method.