| With the development of oceaneering industry in our country, lifting operations are used in increasing frequency on vessels or ocean platforms, the operations are more and more difficult with the operating envelope ranging from offshore to deep sea, so far as to ultra deep-water. The movement of vessels(or ocean platforms) and waves can have great influence on the lifting operations, even cause failures. Consequently, it is necessary to study heave compensation technology to enhance safety and stability of the operations.The thesis studies active heave compensation control system in vertical direction on the background of lifeboat lifting operations at sea, it proposes a kind of active heave compensation control system based on judgment of wave trend, this system adds occasion judgment and process control function when lifeboat getting into or out of water comparing with traditional active heave compensation control system, it can make further improvement in safety and stability of the operations. Its main ideas are as follows:acoustic wave guide, MRU(Motion Reference Unit, hereinafter referred to as MRU), tension sensor and speed sensor are applied to form sensor network which measures the motion of wave, vessel and lifeboat, the information collected by sensor network is transferred to the controller, through analyzing and judging the information the controller controls hydraulic actuating mechanism to lift or lower the lifeboat to fulfill the goal of heave compensation.The algorithm of data analysis and process of acoustic wave guide is studied, the technology of motion measurement and analysis of vessels in vertical direction is studied, principles of active heave compensation in vertical direction are analyzed.The frame of active heave compensation control system in vertical direction is designed and divided into three parts:sensor network, controller and hydraulic actuating mechanism, the schematic diagram of hydraulic actuating mechanism is designed, and the model of control system is built and simulated analyzed.The active heave compensation control system in vertical direction is designed based on PLC, hardware configuration is finished and control procedure is wrote. |
