Assembly Modeling Method Of Chain Manipulator Based On Absolute Nodal Coordinate Formula

With people's continuous and rapid exploration of natural science and people's continuous pursuit of higher material living standards,people pay more and more attention to the dynamic characteristics of machinery,vehicles,robots,satellites,rockets and so on.Then more and more multi-body system problems are proposed,and with the continuous improvement of computer,computing software and numerical calculation methods,it provides the possibility for the modeling and calculation analysis of such problems.In order to solve these problems,many methods have been proposed,including relative coordinate method,absolute coordinate method.Among them,the absolute nodal coordinate formula was first proposed by Shabana.A.A.in 1996.In this paper,this method is used to deal with multi-body system.However,different from the previous absolute node coordinate method in dealing with multi-body system,when establishing the dynamic equation,the assembly method is used to splice the members.For different connection methods between members,the assembly method is used The methods used are also different.In this paper,the problem of chain manipulator arms composed of N flexible links and N rigid hinges is studied.The rigid hinge is simplified as a lumped mass,and the absolute nodal coordinate formula is used to establish the dynamic model of the chain manipulator through the assembly method.The dynamic equation of the system is derived,and the assembly method is verified by the numerical simulation example.At the same time,non group method is used to compare with group method.Because constraints have been introduced into the set method before the dynamic equation is obtained,the dynamic equation obtained by the set method is more simplified,and the dynamic equation obtained by the non set method needs to consider the constraint relationship,so the amount of calculation is larger.Therefore,in theory,the set method can obtain the same results as the non set method on the premise of shorter operation time.Through the comparison of the two results,the accuracy of this idea is verified.