Motion Accuracy Modeling And Compensation For Floating-base Cable-typing Close-coupling Multi-robots Towing System

In marine engineering,floating crane is an indispensable heavy equipment in complex sea surface operation tasks such as sea surface lifting operation,sea surface platform installation operation and so on.Because the hull is affected by wind and waves and other factors,the floating crane will have complex dynamic response during the operation.This will not only reduce the positioning accuracy of hoisting,but also produce additional dynamic load,thus threatening the safety of offshore hoisting operations,which may cause serious work accidents.Therefore,the traditional floating crane can not meet the increasing requirements of offshore operation in terms of accuracy,efficiency,load capacity and safety performance.Combining the flexible cable parallel robot with the floating crane,a new type of floating multi-robot coordinated lifting system is proposed,which can effectively make up for the defects of the traditional marine crane.The floating multi-robot coordinated lifting system not only has high load capacity,but also can effectively eliminate the sloshing of suspended objects by real-time control of flexible cable parallel system,thus improving the accuracy,stability and safety of sea surface lifting operation.Therefore,based on the traditional fixed multi-robot coordinated lifting system,the design of floating multi-robot coordinated lifting system structure form,and its kinematics,dynamics,error model and control system and other basic problems,which is an innovation of marine engineering equipment as well as a breakthrough in high technology.Based on the floating robot,different configurations of the floating multi-robot coordinated lifting system are designed,and the spatial configuration and kinematic model of the system are described.The forward kinematics,inverse kinematics and fluid-solid coupling dynamics models of the floating robot are established by using the homogeneous matrix method.The dynamic response characteristics are analyzed by the kinetic model,and the inverse kinematics model is verified by simulation.Based on floating robot,a coordinated lifting system of floating multi-robot is designed.The spatial configuration and kinematic model of the lifting system are described.Using Newton-Euler equation and Lagrange equation,the dynamic model of lifting system is established.Then the idea of mathematical analysis is introduced,and a new model is proposed to describe the bidirectional dynamic coupling caused by load motion and floating base motion.And the kinematic compensation scheme is used to eliminate the influence of kinetic coupling on motion accuracy.The dynamic response of the system in vertical direction under different coupling conditions is analyzed and compared.The dynamic response of the system in vertical direction under different coupling conditions is analyzed and compared.The results can be used in the theoretical research and prototype development of this institution,as well as in the dynamic response research of crane system.The research object is fixed multi-robot coordinated lifting system and floating multi-robot coordinated lifting system.Based on the kinematic model of the two systems,the matrix total differential method is introduced to model the comprehensive error of the two systems.Based on the comprehensive error model,the sensitivity of error sources and the time-varying reliability of system output are analyzed.Combined with a practice,MATLAB is used to analyze and solve each model.The above research results have laid a foundation for the further theoretical research and design and control system research of study of the control system.At the same time,it also provides a new idea for the research of the parallel system of rope traction and the dynamic response of the crane lifting system.