| Title |
Design of Hydraulic Feedback Structure PI Controller for Removing Servovalve Offset in Hydraulic Actuation System |
| Authors |
구정회(Jeong-Hoi Gu) ; 김인주(In-Ju Kim) ; 최장영(Jang-Young Choi) ; 이상정(Sang-Jeong Lee) |
| DOI |
https://doi.org/10.5370/KIEE.2019.68.6.761 |
| Keywords |
PI Controller ; Hydraulic Actuation System ; Servovalve ; Null Drift |
| Abstract |
Servovalves have been used to control the position of the hydraulic actuation system for missile. However, the null shift of the servovalve can be vary depending on the supply pressure, vibration, shock and temperature. This problem causes position error in the hydraulic actuation system. Therefore, we designed an algorithm to remove the servovalve offset by adding an integrator to the existing proportional controller. However, the integrator usually has drawbacks such as stability and wind-up problems. To overcome this problem, we propose the design of a hydraulic feedback structure PI controller with a hydraulic pressure detector and an integral limiter that satisfies fault tolerance. Several experiments were performed to verify the proposed method. It is shown that the proposed hydraulic feedback structure PI controller is more stable than the conventional PI controller when the hydraulic pressure is supplied. Compared with conventional proportional controller, the proposed method is very efficient to overcome position error of the hydraulic actuation system caused by the null shift of the servovalve. Moreover, the dynamic response of the proposed method is similar to the existing proportional controller. |