Workspace Analysis And Parameter Optimization Of Delta Parallel Robot

As a kind of parallel robot,Delta robot inherits the advantages and disadvantages of parallel mechanism.Because of its good rigidity,strong bearing capacity,high motion and positioning accuracy,it is widely used in minimally invasive surgery in medical field,sorting and packing in industrial and food fields.In terms of disadvantages,due to the small workspace and complex structure of the Delta parallel robot,it is limited in some working scenarios that require simple structure and large workspace.At present,there are two main problems in the mechanism of Delta parallel robot.One is due to the closed-loop motion branched chain of the parallel mechanism itself,which leads to the limitation of its working space.The other is due to the complexity of the structure of the parallel mechanism itself,which leads to the fact that most domestic enterprises adopt empirical design for the mechanism body of Delta parallel robot,and lack systematic theoretical design reference.In this paper,starting from the shortcomings of the small workspace of the parallel mechanism,the influence of the mechanism parameters of the Delta parallel robot on the volume of its workspace is studied.Taking the trajectory workspace volume of the Delta parallel robot as the objective function,the optimization design of the mechanism parameters is carried out,and then from the kinematics level of the mechanism,it provides a theoretical reference for the mechanism design of the Delta parallel robot.The specific work is as follows :Firstly,this paper takes the Delta parallel robot of R-D4-800 A sold by a company in Shenzhen as the research object,analyzes the mechanism composition principle of this type of Delta parallel robot,and obtains the position forward solution mathematical model and position inverse solution mathematical model of its kinematics through analytical method.Secondly,based on the mathematical model of forward kinematics and inverse kinematics,the workspace of the mechanism is analyzed.Aiming at the shortcomings of the method of solving the workspace in the numerical method,a new method of solving the workspace is proposed,which is based on the mathematical model of inverse kinematics and supplemented by the mathematical model of forward kinematics.The reachable workspace of the Delta parallel robot is generated by this method while keeping the basic parameters of the Delta parallel robot of R-D4-800 A unchanged.The relationship between the dexterous workspace and the trajectory workspace and the reachable workspace is analyzed.Through the analysis of the singular configuration of the Delta parallel robot,the singular position in the workspace is removed,and the analysis and solution of the trajectory workspace of the Delta parallel robot is completed.Finally,based on the mechanism of the parallel mechanism,the range of the parameters of each mechanism is determined.Taking the trajectory workspace volume of the Delta parallel robot of R-D4-800 A as the objective function,the influence of single mechanism parameters and composite mechanism parameters on the trajectory workspace volume is studied by using the control variable method.The genetic algorithm is used to optimize the parameters of the Delta parallel robot of R-D4-800 A within the range of given mechanism parameters,and the workspaces of the two mechanisms before and after parameter optimization are compared and analyzed.It provides a theoretical reference for the mechanism design of Delta parallel robot at the kinematic level.