Speed Control of a DC Motor System through Delay Time Variant Network

Nowadays, information and communication technologies are rapidly developed. Therefore, it is easy to make up a computer network like local area network and its cost is also low. It is guessed that it is standard tool for data communication even in motor control system. In the present work, a specific speed control system for a small DC motor including an Ethernet network is interested. However, the network always has a delay time and it seems to be varied randomly on the surface. This phenomenon gives disadvantage to the control system. Therefore, we discuss the control characteristics and the problems when the DC motor is driven under the system including the Ethernet network. Especially, the relation between the distribution of delay time and control characteristic is examined at the new point of view