Reasearch On 3-PRS+RRP Stability Access Bridge

Ships sailing on the sea will be in the wind,wave,chung Marine environment disturbance such as multi-dimensional motion,the movement to personnel or the safety of the cargo transport,wind power tower or the rig failure to timely make emergency repair various poses a serious threat.Shipboard stable platform can compensate the motion of ship,to keep charged objects under the inertial system is relatively stable.In sea stability is developed on the basis of stabilized platform technique approach of institutions,able to isolate the ship motion,and can be passed to the ship or offshore platform security personnel or goods,to our country economic construction and national defense security plays an important role.In view of the existing offshore personnel or to compensate for cargo transfer technology is difficult to achieve large travel,being a small deck area,large stiffness,strong carrying capacity,this paper has carried out six degrees of freedom of composite group and steady approach of institutional research.The main research contents are as follows:Firstly,analysis of ship motion parameters,typical made the design of institutions.Aimed at the problems existing in the existing maritime personnel or cargo transport technology,demand based on the engineering practice,this paper proposes a position of the intelligent control device of balancing with six degrees of freedom hybrid institutions,large travel with large stiffness,compensation,compact structure,strong carrying capacity,take up the deck area is small,and automatically compensate the wave disturbance,etc.The position of solution and the parallel part position solution are analyzed.Through the agency of constraint condition to search out the agency parallel part of work space.Secondly,based on the actual application requirements,3-PRS parallel multi-dimensional motion platform to compensate ships,series of RRP to compensate with mobile,to ensure the bridge arm end point relative to the earth’s dynamic static,kinematic model is set up,get the position inverse solution,the driving speed,acceleration,and the numerical example is analyzed.Stable approach of compound Jacobi matrix was deduced,based on the principle of virtual work and mixed Jacobi matrix compound institutions established 3-PRS + RRP stiffness model,and on the basis of the explicit direction stiffness model.Thirdly,based on the screw theory,the paper introduces the spinor representation of single rigid body Newton-euler dynamic modeling method,based on the kinetics of the parallel mechanism based on the spinor Hessian matrix and the general dynamic model of parallel mechanism spinor said.Combination of d ’alembert’s principle,the establishment of a 3-PRS + RRP six degrees of freedom and stable approach of dynamic model,and the corresponding numerical example is given for validation.For driving force of the stabilized platform three branch joints motion vary widely,selection and control of the hydraulic cylinder adds additional difficulties,bridge arm pitching and telescopic movement and make the focus of the whole bridge arm produce very big change,using the method of weight position is adjustable.Finally,determine the steady approach of system composition,3-PRS + RRP stable approach of institutions for structural design,stability analysis and design approach of the hydraulic servo drive system,determine the stable approach span of control and drive mode,completed the design of the hydraulic system,analyzes the stable approach of four kinds of working condition,and the main hydraulic components design and type selection.