| Marine crane,as one of the important lifting and transportation equipment in marine engineering,has been widely used in the fields of sea transportation,cargo lifting and navigation mark distribution.Because of the special working environment of marine crane,the influence on the lifting and rolling motion of the crane system is serious under the interference of many factors of the wave,so it is difficult to ensure the positioning accuracy of the hoisting operation,reduce the operation efficiency and is not conducive to the safe and stable operation of the marine crane.Therefore,it is of great significance to design the heave compensation system and the anti rolling compensation system for the heave and swing of marine crane.In the aspect of heave compensation,based on the principle of velocity compensation,the kinematics analysis of the lifting system is carried out,and the relationship between the compensation speed and the speed of the lifting motion is obtained.Combined with the characteristics of the lifting compensation device,the pump controlled hydraulic motor is adopted for the high power servo system;The secondary adjustment technology is used in the compensation mechanism;In terms of energy saving,the secondary element and accumulator are used to recover the energy in the load reduction compensation stage;In the aspect of lifting mechanism,differential planetary reducer is used to synthesize the main lifting motion and the compensation motion of the load,and finally determine the overall scheme of the semi-active winch lifting compensation system.According to the compensation index of the system,the hydraulic schematic diagram of the lifting compensation system is established,and the calculation of the system parameters of the hoisting mechanism,drum,differential reducer and the main circuit in the hydraulic system is completed.The model of the lifting compensation system is simulated by AMESim software.The tracking of the compensation speed of the lifting system to the ship’s lifting speed under the rising and falling conditions is obtained.The accuracy of the speed compensation is high,and the effectiveness of the working principle of the semi-active winch lifting compensation system is verified.In the aspect of lifting load anti rolling,combined with the characteristics of traditional anti rolling device,the mechanical anti rolling mechanism of hanging plate is put forward,and the spatial force of the traction cable of hanging plate is analyzed,and the corresponding relationship between the swing angle of hanging plate and the tension of traction cable is obtained.Based on the principle of constant tension control,the dynamic model of the cable is established,the differential equation is transformed into an algebraic equation,and the transfer function of tension control is derived.According to the operation principle of the anti rolling device,the constant tension control schematic diagram of the hydraulic system is designed,the reversing and speed control characteristics of the system are analyzed,and the tension control of the traction cable is completed.Determine the working condition requirements of the anti rolling system,calculate the maximum tension load of the system under the corresponding swing angle,and complete the selection calculation of the hydraulic motor,hydraulic pump and pressure relay.The simulation environment of constant tension system is simplified.The tension control model and constant tension hydraulic simulation model are established by using AMESim and Simulink software.The key parameters of sub components of the model are set according to the theoretical calculation results.Finally,the simulation results show that the constant tension system has good dynamic performance,high control precision and fast response speed under the condition of given variable load signal,and the external output of parameters such as pressure,flow,torque and speed of the hydraulic system can be kept constant,which meets the requirements of constant tension control theory. |
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