Modeling And Simulation Of Active Wave Compensation Crane System Based On Modelica

Marine crane is a typical multi-disciplinary,multi-system and multi-domain integrated offshore engineering equipment for the development of marine resources.It is a complex system that integrates subsystems in the fields of control,electronics and hydraulics on the basis of mechanical systems.Most of the current research on the modeling and simulation of marine cranes is limited to a single domain,it is difficult to consider the coupling relationship between components in different domains,and it is not conducive to expansion and inheritance.Therefore,in order to accurately analyze the dynamic characteristics of the marine crane system and improve the comprehensive performance of wave compensation,it is necessary to carry out unified modeling,simulation and optimization of the marine crane system.This article aims to design and develop a universal and extensible model library of active wave compensation crane system based on Modelica language,and carry out active wave compensation crane system simulation research based on the system model.First,the composition and working principle of the active wave compensation crane system are introduced in detail,the working principle and mathematical model of the key components of the crane system are analyzed,and the crane component model is established using Modelica language based on the mathematical formula,which specifically includes the secondary motor,Constant pressure variable pump,accumulator,overflow valve,wire rope,brake and other components.Based on the component-subsystem-system model construction process,each subsystem model and active wave compensation crane system model are established.The built crane system model library has the characteristics of strong scalability and reusability,and can lay the foundation for the parameterization and component system design of the crane system,and can quickly verify the crane system design plan,greatly improving the crane system Design efficiency.Secondly,based on the system model,a certain type of active wave compensation crane system is simulated and studied.The correctness of the component model is verified by comparing the same test cases with AMESim’s hydraulic components,which provides a guarantee for the reliability of subsequent simulation analysis.Simulate the normal working conditions during wave compensation and analyze the impact of the operating status and dynamic characteristics of the crane system and the parameters of key components on the system performance.The results show that the controller with only one speed loop has low compensation accuracy and requires subsequent optimization.By means of parameter sweeping,the influence of typical component parameters on system performance and the system’s ability to adapt to extreme conditions are analyzed.Aiming at the fault conditions,the analysis of the two typical fault phenomena of motor internal leakage and external leakage and the process of fault transmission laid a certain foundation for future model-based fault diagnosis.Finally,for the problem of low accuracy of the wave compensation of the crane system under normal working conditions,by analyzing and comparing the two control schemes of speed loop and position loop + speed loop,the optimal control scheme is determined to be a combination of the two.Aiming at the problem of overshoot of the crane system at the start of the wave compensation function,the control logic at the instant of start was optimized to suppress the phenomenon of instantaneous instability of the system starting wave compensation.In view of the problem of low mass load compensation accuracy,the controller parameters of the crane system were optimized to improve the compensation performance.