Journal of Advanced Marine Engineering and Technology

The Korean Society of Marine Engineering (한국마린엔지니어링학회)
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Robust control of a heave compensation system for offshore cranes considering the time-delay

시간 지연을 고려한 해상 크레인의 상하 동요 보상 시스템의 강인 제어

  • Seong, Hyung-Seok (Department of Convergence Study on the Ocean Science and Technology, Korea Maritime and Ocean University) ;
  • Choi, Hyeong-Sik (Department of Mechanical and Energy Systems Engineering, Korea Maritime and Ocean University)
  • Received : 2016.10.24
  • Accepted : 2017.01.19
  • Published : 2017.01.31
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Abstract

This paper introduces a heave compensation system for offshore crane when it subjected to unexpected disturbances such as ocean waves, tidal currents or winds and their external force. The dynamic model consists of a crane which is considered to behave in the same manner as a rigid body, a hydraulic driven winch, an elastic rope and a payload. To keep the payload from moving upwards and downwards, PD(Proportional-Derivative) control was applied by using linearization. In order to achieve a better performance, the sliding mode control and the nonlinear generalized predictive control algorithm was applied according to the time-delay. As a result, the oscillating amplitude of the payload was reduced by the control algorithm. Considering the time-delay involved in the system to be one second, nonlinear generalized predictive controller with a robust controller was a suitable control algorithm for this heave compensation system because it made the position of te payload reach the desired position with the minimum error. This paper presented a control algorithm using the robust control and its simulation results.

이 논문에서는 해상에서의 환경 하중과 외력을 고려한 해상 크레인의 상하 동요 보상 시스템에 대해 연구한 내용을 소개한다. 이를 위해 강체라 가정된 해상 크레인과 유압 구동식 윈치, 탄성력을 갖는 로프, 그리고 로프 끝단의 중량물로 구성된 동역학 모델을 먼저 살펴본다. 중량물의 상하 동요 움직임을 보상하기 위해, 선형화를 통한 PD 제어를 적용했다. 또한, 비선형 시스템에 맞춘 슬라이딩 모드 제어기 및 시간 지연을 고려한 비선형 일반 예측 제어 알고리즘을 사용한 제어를 적용했으며, 그 결과 진동폭이 줄어듬을 확인할 수 있다. 결과적으로, 1초의 시간 지연을 고려하여 설계한 강인 제어기를 활용하게 되면, 상하동요 보상시스템에서 오차를 가장 많이 줄여서 본 시스템에 적합한 제어 알고리즘으로써 활용할 수 있음을 볼 수 있다.

Keywords

References

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