Research On Dynamics Modeling Method Of Distributed Multibody System Based On Dual Number

With the continuous development of space technology,space missions become increasingly complex.In the face of complex space missions,sometimes it is impossible to rely on astronauts alone,so we need to use auxiliary tools.As the main auxiliary tool in space mission,space manipulator has been widely used in space station assembly construction,daily maintenance,on orbit service and so on.Therefore,it is of great significance to carry out dynamic modeling of space manipulator system both in theoretical research and in engineering practice.Therefore,this paper takes the multibody system space manipulator as the research object,based on the modeling method of multi-body system,combined with the mathematical tools of dual number,carries on the kinematics and dynamics modeling,and proposes a path planning algorithm of space manipulator task obstacle avoidance.The work of this paper mainly includes the following aspects:(1)This article first introduces the current development of space manipulator around the world.Aiming at the dynamic modeling of space manipulator,the research status is described,and the methods of path planning for space manipulator are explained.(2)The paper introduces the theory of dual number,and gives the expression of space rigid body motion transformation using dual number.Based on the dual number theory,the kinematics of space manipulator is modeled.The model is compared with the kinematic model based on rotation matrix to verify the correctness of the model.(3)Based on the concepts of dual mass and dual momentum,the dynamic model of space single rigid body is established.Considering that the manipulator is a multi rigid body system including some single rigid bodies and moving joints,the dual velocity screw expression between each joint is derived by using the pair even number.The expression of joint acceleration vector is obtained by derivative operation.Finally,the dynamic model of space manipulator based on pair dual number is established by Newton Euler method,which is a common modeling method of multi-body system.(4)Considering the complexity of space manipulator workspace,an improved path planning algorithm for obstacle avoidance based on random tree search algorithm is proposed,which is based on the random tree search algorithm,which guides the random tree to expand towards the task target direction,and speeds up the search efficiency of the random tree;designs a collision detection algorithm between the manipulator and the obstacle;designs a base The forward and inverse kinematics of manipulator based on geometric relation is solved.Calculation results prove contrasted with the traditional method,algorithm improves the search efficiency of the path.At the end of the paper,the deficiencies of this paper and the next research work are presented.