Improvement of Transient Response Charateristics of a Position Control Hydraulic Servosystem Using Observer (I)

관측기를 이용한 위치제어 유압 서어보 시스템의 과도응답 특성 개선 (I)

The state variables estimated in an observer were useed in feedback control of a hydraulic servosystem to increase the system stability and to enhance the system performance. The nonlinear hydraulic servosystem with the inherent nonlinearities due to the square root function of flow equation, the Coulomb friction and so on, was modelled as a fourth order linear hydraulic servosystem. Also, a second order linear system was derived for the observer-controller design. For these models, a fourth order linear observer and a second order linear observer were constructed respectively to evaluate the performance of the observer-based hydraulic servosystem. The results obtained from series of simulation showed that the system which had shown oscillatory phenomenon under proportional control became stable with the same maximum acceleration and velocity that it had started under proportional control.

본 연구에서는 제어대상으로 설정된 유압서어보 시스템은 비선형 시스템이므 로, 실제로 측정한 상태변수와 관측기에서 추정한 상태변수를 비교하여 이들이 서로 일치하는 것을 보임으로써 관측기에서 추정한 다른 상태변수들에 대한 신뢰도를 높일 수 있다. 따라서 본논문에서는 전차수 관측기를 사용한 경우에 대하여 고찰한다.