Study On The Analysis Of The LNG Loading Arm Mechanism And Control Of Ship Shore

Shore LNG marine loading arm is the key equipment for loading and unloading dock in Yangtze River LNG,LNG transport process,follow the ship loading arm is always in a state of movement,the stability of its control mechanism of LNG safe transport has an important influence.Based on the seven bar LNG loading arm of a company based on the shore ship,through the research of configuration on its mechanism and kinematics,forward position tracking control scheme of arm or LNG mechanical model,improve the stability and safety in the process of using the system.The following research work is carried out in this paper:Firstly,the configuration of the seven arm LNG arm mechanism is studied.The general design method of loading arm configuration in-depth analysis,on the basis of the mechanism of connecting rod,rod with,contracted link adjacency matrix is studied,finally obtains the general type,seven pole LNG loading arm mechanism development mechanism,has important significance for the mechanism innovation.Secondly,the kinematics of the arm is analyzed.For the seven bar LNG handling execution end position and velocity,boom angle and hydraulic cylinder stroke to establish the mathematical model,the velocity Jacobian matrix,based on the singularity of movement and satisfy the non singular conditions are analyzed,and meet the movable condition in the initial unloading arm length parameters,finally the work space the loading arm and analysis.Then,According to the movement requirements of LNG loading and unloading arm,the control strategy of LNG loading arm is put forward.Firstly,the hydraulic system of LNG loading arm model,three position four way Y reversing valve and electro-hydraulic proportional control valve are introduced in the model,the hydraulic control system with active control arm posture and passive power follow floating function.Then,the dynamic model of the loading and unloading arm and the PD position control model are established to lay the foundation for the movement of the arm and the joint simulation.Finally,the virtual prototype of LNG handling arm is established,and the control scheme is verified in ADAMS simulation of the actual movement of the end of the reverse kinematics simulation,obtained the movement of the input,and the stress of each joint.The model of LNG ADAMS control system is established in MATLAB,and the tracking performance of the control system is obtained by the joint simulation analysis of thevirtual prototype model.Through the research work of this paper,the mechanism analysis and control system model of the LNG loading and unloading arm is completed,which is of guiding significance for the improvement of the existing system and the improvement of the control model of LNG.