Constant Tension Control of Hybrid Active-Passive Heave Compensator Based on Adaptive Integral Sliding Mode Method

Heave compensation systems are of great importance to the safety and efficiency of marine operations subject to irregular-wave excitation. While many efforts have been made to improve the displacement compensation control, only a few of researchers pay their attention on tension compensation control. This paper presents an adaptive robust integral sliding mode control (ARISMC) based on the back-stepping method to realize constant tension control of hybrid active-passive heave compensator (HAHC) applied to heavy deep-sea towing systems. The proposed ARISMC is intended to overcome the effects of parametric uncertainties, uncertain nonlinearities, and external disturbances in the electro-hydraulic system of HAHC. The stability of the whole system is proved using common Lyapunov method. To verify the effectiveness of the proposed controller, we carried out a number of simulations and experiments using the measured heave motion data under different sea conditions. The results demonstrate that the ARISMC controller presented in this paper has better advantages than the traditional PI controller in the accuracy and robustness of tension compensation.