Research On Control Strategy And Kinematic Performance Of Rigid-Flexible Hybrid Wave Compensation Mechanism

In today’s increasingly fierce international competition,marine resources have become a new point of struggle for all countries.Whether it is the exploration and utilization of marine resources or the enhancement of the military strength of coastal defense,it is necessary to vigorously develop advanced marine equipment support.Marine hoisting equipment is the medium to realize cargo transfer,which affects the efficiency of cargo loading and unloading.In order to eliminate the relative motion of the ship in the multi-dimensional direction due to waves,a new type of wave compensation mechanism in the multi-dimensional direction is urgently needed.Based on the structural characteristics of the parallel structure of the rope,a rigid branch chain is introduced to form a rigid-flexible hybrid parallel structure.The freedom of the organization is verified based on the spiral theory,and the feasibility of the organization is demonstrated.On this basis,the kinematics model of the mechanism is established,and the inverse position solution,forward position solution,velocity and acceleration formulas of the mechanism are derived.The derived kinematic model is verified by virtual prototype technology and numerical simulation technology.Through mechanical analysis,the static model of the mechanism is established,and the force Jacobian matrix is obtained,which lays the foundation for analyzing the dynamics and mechanical properties of the mechanism;based on Newton-Euler method,the dynamic model of the mechanism is established,and the numerical value is obtained through MATLAB Comparing the calculation with the ADAMS virtual prototype simulation,the correctness of the dynamic model is verified.The PD modified feedforward control strategy is designed and the consistent stability verification is carried out.Comparing the control strategy with the traditional PD control strategy,the PD modified feedforward control strategy has higher accuracy and effectiveness.Based on the force-closed vector method,the working space of the mechanism is derived,and the rule of the working space changing with the structural parameters of the mechanism is analyzed.Taking the condition number of the kinematics Jacobian matrix as the evaluation index of the mechanism’s dexterity,the change rule of the mechanism’s dexterity at different positions is analyzed;on this basis,the influence of the change of the structure parameters of the mechanism on the dexterity of the mechanism is analyzed.The overall stiffness of the mechanism is analyzed,and the distribution rule of the overall stiffness of the mechanism is analyzed.Compared with the parallel structure of pure rope,the rigidity of the rigid-flexible hybrid parallel structure is significantly improved.Finally,based on the results of theoretical analysis,the prototype structure of the mechanism is designed and processed and assembled.Under the existing conditions,experiments were conducted on the performance of the mechanism to verify the compensation performance of the mechanism,and provide experimental basis for further mechanism improvement.