| With the rapid development of science and technology in the world,the research on the mechanical arm in the world is deepening day by day,and due to the continuous increase of labor costs,more and more industrial robots into various industries.At present,parallel manipulator and series manipulator are mainly used in production at home and abroad.However,in practical application,we find that the load capacity of the serial manipulator is small,and because of the series,the error will also accumulate.Although the parallel manipulator can make up for these shortcomings of the series mechanism,it also has many problems,such as a large footprint and limited working space.The hybrid manipulator can integrate the advantages and disadvantages of the two kinds of manipulator to achieve better work requirements.However,due to different analysis methods,there are very few researches on the hybrid manipulator at home and abroad.In this context,a new type of hybrid mechanism is proposed in this thesis.The hybrid mechanism is divided into two parts.One part is a hybrid mechanism composed of a 3-DOF(U+UPS)P+UPS with closed loop and a 3-DOF series manipulator.For this mechanism,since it is impossible to provide a complete calculation formula for the hybrid mechanism,the analysis method of this mechanism is to analyze the parallel mechanism and the series mechanism respectively,and then take the starting point of the series mechanism as the end point of the parallel mechanism,and then carry out the reverse solution.For this kind of hybrid linkage mechanism,the output values of the end of the mechanism can be given,and then the input values of the attitude Angle of the series linkage can be inversely solved,and then the input values of the bar length of the parallel linkage can be inversely solved by taking the starting point of the series linkage as the end point.The output of the mechanism can also be solved forward by giving input values.Firstly,we solve the vector chain of the parallel mechanism,establish the position equation of the parallel mechanism,derive the length of the branch chain,the driving velocity and the angular velocity of the branch chain,and derive the mapping model of the branch chain velocity and the platform velocity of the mechanism.Similarly,D-H parameter method is applied to the kinematics analysis of the serial mechanism,forward and reverse solutions of the mechanism are carried out,and the transformation matrix of Angle change and end position change is established,so as to establish the velocity mapping model.Thus,the velocity transformation matrix of the whole mechanism can be established.Secondly,the virtual work principle is used to model the dynamics of the parallel part,and the driving force of each branch chain is solved according to the mapping model between the velocity of the branch chain and the velocity of the moving platform.Lagrange method is used to analyze the series part and establish the dynamic model.The driving force of each joint is also solved by using the velocity and acceleration of each joint.Finally,using the MATLAB software and the Adams software to programming and simulation of mechanism,firstly,the MATLAB software is used to change the program,we analyze the expressions to express the form of various data by function image,then the modeling and simulation in Adams software,the working environment and a driving force to carry on the function of each joint,and using the Adams simulation function to express the form of various data by function image,then compared with MATLAB functions in the image,the correct dynamic model can be verified. |
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