Search

Mining ship is an essential Marine equipment in the exploitation of Marine resources. In order to reduce the heave motion, it is necessary to compensate the mining ship for heave compensation. A composite active and passive integrated heave compensation system based on composite hydraulic cylinder is proposed. In order to improve the control accuracy, an active compensation control strategy based on Mamdani fuzzy PID is proposed to reduce the compensation error under heave interference. Firstly, the heave compensation principle was introduced, and the calculation process of ship"s heave amplitude under different sea conditions was deduced based on Mohr"s empirical formula, then the promotion heavy compensation mathematic model and transfer function of the system were established, finally the proposed fuzzy control algorithm was used to control the system under the regular ocean wave and irregular wave and compare with the traditional PID control effect. The results show that under the two kinds of ocean wave, the error of the fuzzy control algorithm is less than the error of the traditional PID control algorithm, It can be seen that fuzzy control algorithm has obvious advantages. [ABSTRACT FROM AUTHOR]

The unexpected heave motion of vessels generated by waves has always threatened the safe operation of mining vessels. The heave compensation system is a critical equipment for offshore cranes to ensure the safety and stability of the deep-sea mining vessel operation. Unfortunately, the nominal load of the mining vessel transporting minerals has become increasingly large, which has led to the dynamic performance of the heave compensation decline and a significant increase in energy consumption. To solve these problems, a semiactive heave compensation system and fuzzy logic-based controller are proposed in this paper. First, an active-passive hybrid heave compensation system is designed to reduce energy consumption greatly. The virtual prototype models of the proposed heave compensation system in a 500-ton deep-sea mining vessel are also built. Then, an adaptive tuning PID controller is developed based on the Transfer function of the heave compensation system and Mamdani-type fuzzy logic. Virtual prototype simulation results of AMESim-Simulink joint simulation illustrate that the accuracy of compensation for the four or six sea states reaches more than 90% with the proposed method and the power of the active compensation system is about 21% of the total power. Finally, the experimental results are included to demonstrate the effectiveness of the proposed semiactive heave compensation system. [ABSTRACT FROM AUTHOR]

With the depletion of land resources, demands for marine resources mining is increasing, the mining vessels which is known as one of the most important offshore equipment are widely concerned. The motions of wave surges in the marine environment will affect the operation of mining vessels, especially for the heave motion which will cause serious disturbances to the mining vessels during operation, and even the damage of the hull structure and related mining facilities. Hence, it is very necessary to compensate for the heave motion of the mining vessel, and a hydraulic cylinder-based active-passive integrated composite heave compensation system is designed in this paper. Firstly, the structural composition and working principle of the heave compensation system are introduced, and its mathematical model is also established. Secondly, the frequency domain and time domain analysis are carried out using AQWA software to obtain the heave displacement response of the ship under regular and irregular waves of six sea states as the desired compensation displacement. Finally, the controller of the active-passive heave compensation system is designed, and a fuzzy logic control strategy based on Mamdani type is proposed, and the control performance is analyzed. The results show that the accuracy of the fuzzy logic control algorithm is better than the traditional PID control algorithm, and the laws and methods of PID adjustment are obtained, which proves that the fuzzy logic control algorithm has obvious advantages for engineering applications. [ABSTRACT FROM AUTHOR]