Integrated Control Design of Pneumatic Servo Table Considering the Dynamics of Pipelines and Servo Valve
Jun Li*, Joonmyeong Choi*, Kenji Kawashima*,
Toshinori Fujita**, and Toshiharu Kagawa*
*Tokyo Institute of Technology, 4259 R2-46, Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
**Tokyo Denki University, 2-2 Kanda-nishiki-cho, Chiyoda-ku, Tokyo 101-8457, Japan
In this paper, integrated control design for the pneumatic servo table system considering the dynamics of pipelines and servo valve is studied. The table is mainly composed by a pneumatic actuator, a highperformance pneumatic servo valve and pipelines. The pneumatic actuator utilizes a pneumatic cylinder with air bearings. The servo valve has high dynamics up to 300 Hz and is connected to the pneumatic actuator by pipelines. The system is pneumatically driven, providing the advantages of low heat generation and non-magnetic, nature suited to precise positioning. To simulate the system, we designed a linear model considering pipelines and servo valve dynamics. Comparison results showed that with a 7th order linear model, the discrepancy between experiment and simulation results was much smaller than when using a 3rd order model. The model’s complexity made it necessary to reduce the model’s order. Two poles are much further from the imaginary axis compared with other five poles in the pole loci of the 7th order model, so the model is reduced to a 5th order. A comparison of simulation and experiment results showed that the 5th order model matches the real system well.
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