Kenshi Matsuo

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

Open-Loop Control of a Stepping Motor through IP Network

In this work, IP (internet protocol) network- based control system of a stepping motor is constructed and the control performance is examined. The network has transmission time delays, jitters and packet loss. These give disadvantages to the control system. Therefore, it is important to examine the performance degradations when a motor is driven under the system through IP networks. The position control experiments are done in open-loop using a stepping motor, which is one of the most popular one and an appropriate one for a position control. Then the control ability is examined against various network conditions.

A gain scheduling speed control of a small DC motor through IP network

When IP network-based control systems of small DC motors are controlled, varying time delays and packet losses through the network cause the performance degradation. A simple scheme for overcoming it is that, using jitter buffer, varying delays is treated as constant delays in the systems. That is, control designs are done as the systems with dead times. Here the issues are how much buffering time jitter buffer needs. In this paper, a scheme applying gain scheduling and jitter buffer is proposed. For confirming the effectiveness, speed control experiments of a small DC motor through IP networks are conducted, and it is shown that the scheme is effective.

A study of network emulation for IP network-based control system of a small motor

In networked control system (NCS) though IP networks, there are the issues such that time delays, its jitter and packet losses cause control performance degradation. Hence, many control schemes against the issues have been developed. For evaluating the effectiveness of the scheme, control experiments generally need to be done under actual IP networks. However, in actual networks, it is difficult to experiment under various conditions. Hence, the evaluation should be done under networks emulated by emulators because they can make the various realistic conditions. Therefore, it is important to confirm the validity of emulator in the case of using in NCS. In this paper, we discuss the validity of a popular network emulator built-in Linux, called netem, in terms of NCS. As a result, it has been found by experiment that netem in a recent Linux kernel can work well as emulator in NCS.