Structural Analysis And Optimization Of DELTA Parallel Manipulator With Two DOD

Parallel robot has attracted wide attention by scholars for its certain advantages in operation accuracy,space structure occupation ratio,carrying capacity and dynamic response performance.This paper discusses the structure of a DELTA parallel robot with two degrees of freedom.For its kinematics and dynamics,a multi-objective optimization genetic algorithm is adopted to obtain the basic structural parameters meeting the design requirements.The main studies are as follows:(1)The kinematic position model of the parallel robot is derived.The velocity Jacobian matrix is obtained by the positive inverse solution model,and the mechanism model is verified by MATLAB programming.The inverse dynamic mathematical model of a parallel robot is constructed according to the principle of virtual power.In a given example,ADAMS virtual simulation is used to verify the correctness of the dynamic model.(2)The evaluation index of the parallel mechanism kinematics and dynamic comprehensive performance is constructed respectively,and the optimization objective function is constructed according to the performance index.Introduce the mechanism space volume ratio and transmission angle,and the NSGA-Il algorithm is used to optimize the dynamics and then the basic structural parameters of the parallel mechanism are obtained.The servo motor temporarily selected during the structural size optimization is checked to make the motor and the parallel mechanism conform to the principle of rotational inertia matching.The selected motor can meet the speed,torque and power requirements of the parallel mechanism in the typical grasping operation,so as to ensure the effectiveness of the optimization results.The optimization results are verified using local performance indicators.(3)In order to ensure the good static dynamic characteristics,create the three-dimensional model of parallel robot based on the multi-objective optimization structure basic parameters,import the model in the finite element analysis software,solve the mechanism deformation,stress cloud map and low order natural frequency,and verify that the parallel robot structure meets the stiffness and stability requirements.Further,we prove the correctness of the multi-objective optimization method adopted in this paper.