| Title |
The Design of the Fuzzy Logic Controller for Controlling the Speed in theZero-Crossing Speed Region of a Hydraulic System |
| Authors |
Woong-Tae Son ; Seuk-Young Hwang |
| Keywords |
Hydraulic elevator ; Inverter ; PID controller ; Fuzzy controller ; Hybrid fuzzy controller |
| Abstract |
Due to the friction characteristic of pump, cylinder, and between passenger car and the rail, there exist dead zone in the hydraulic system actuated with inverter, which can not be controlled by a PID controller. In this paper, the friction characteristic of a cylinder is considered first, which may cause the uncontrolled speed in the zero-crossing speed region. And then, the zooming fuzzy logic controller is designed to overcome the drawback by the existing PID speed controller. Finally, The proposed hybrid fuzzy controller is applied to the PID controller in the normal speed region, and to the fuzzy controller in the zero-crossing speed region. The reason is that the problem of the uncontrolled speed in the zero-crossing speed region caused by the friction characteristic of the cylinder in hydraulic elevator can be solved, and the effectiveness of the controlling system not only in the zero-crossing speed region but also the overall controlling region including steady-state can be simulated and performed. |