Modeling of active heave compensation system of deep-sea mining based on dynamic vibration absorber and its H∞ robust control
The heave compensation system is vital for the deep-sea mining system undergoes excessive vibrations due to irregular wave loads for both normal operating and extreme conditions. To ensure its safety and operation efficiency, a novel active heave compensation system of deep-sea mining based on dynamic vibration absorber was proposed in this paper. The three-degree-of-freedom dynamic models of active heave compensation system based on dynamic vibration absorber in irregular wave are established. A H∞ Robust controller is designed for active heave compensation system by applying robust loop shaping control. The performance of H∞ robust controller and its robustness stability of the system are simulated and analyzed in frequency domain. The results show that the performance of the system in wave energy concentrated frequency domain of China's deep-sea mining field was improved by the concentrated weighting of acceleration output. And it also shows that the designed H∞ controller is perfect in system robustness stability against some parameter fluctuations of the system model. Therefore the designed active heave compensation system is practical to isolate the lift pipe and its support platform from the significant vibration of the ship motion induced by the irregular wave.
Modeling and simulation of active-controlled heave compensation system of deep-sea mining based on dynamic vibration absorber
The heave compensation system is of great importance to the safety and operation efficiency of the deep-sea mining system subject to irregular-wave excitation. A novel active-controlled heave compensation system based on dynamic vibration absorber for the deep-sea mining system was proposed in this paper. The three-degree-of-freedom dynamic models of active heave compensation system based on dynamic vibration absorber in sinusoidal wave are established. An optimal controller was designed for the proposed system by using Linear-quadratic optimization technique. The performance of the active heave compensation system based on dynamic vibration absorber was computed and analyzed. It is indicated that the heave compensator based on dynamic vibrator absorber with the optimal controller can have the best performance of heave compensation and it is practical to isolate the lift pipe and its support platform from the significant vibration of the ship motion induced by the sinusoidal wave.
Design And Simulation Study On a Virtual Prototype of an Active Heave Compensation System For Deep-ocean Mining
Characteristics of heave compensation systems used on a marine drilling platform or drill-ship are analyzed. An active heave compensation system with two lift cylinders is proposed by COMRA (China Ocean Mineral Resources & Association), which will be used in 1000-m depth ocean poly-metallic nodule pilot mining system. A corresponding virtual prototype of this system is developed. The parametric analyses and operation process simulation have been carried out on this virtual prototype system. The results show this proposed virtual system is feasible. Furthermore, a fuzzy logic control is applied to the design of this system. The control performance is investigated based on the simulation of this virtual prototype. The results show that the designed virtual prototype of heave compensation can reach the design target in virtual simulation.