Research On Configuration Optimization And Trajectory Planning Of Modular Manipulator

With the development of science and technology,modular robotic arms have been widely used in various fields of industrial production,which not only reduces production costs,but also improves production efficiency.Configuration optimization design is the basis for the application of modular robotic arms,so it is of great significance to study configuration optimization methods.In this paper,the operability,the need to overcome gravity and the volume of the working space at the task point are used as configuration optimization indicators,and NSGA-II is used to study the configuration optimization of the modular robotic arm.Based on the configuration optimization of the welding manipulator,trajectory planning is performed for a given welding task.The trajectory planning simulation experiment verifies the adaptability of the welding manipulator to a given task,and proves the feasibility of the modular robot arm configuration optimization method.First,classify the module library and introduce the structural parameters and performance characteristics of each module in the module library.Analyze the assembly method of each module,and use the D-H parameter and the link assembly matrix as the mathematical expression of the configuration of the robot arm.The mathematical expression corresponds to the configuration of the robot arm.Formulate coding rules and perform binary coding on the mathematical expression of the robotic arm.Next,an improved D-H parameter method is used to establish the robot arm link coordinate system,and the robot arm kinematics model is automatically established according to the D-H parameters.At the task point,find the numerical inverse solution of the manipulator and the Jacobian matrix.According to the Newton-Eulerian equation,the Newton-Eulerian iterative method is used to establish the dynamic model of the manipulator.It laid the foundation for the optimal design of the mechanical arm configuration.Then,select the maneuverability,the need to overcome gravity and the working space at the task point as the performance evaluation indexes of the robot arm configuration,accessibility,joint angle range and degrees of freedom as the constraint conditions of the configuration design,using multi-objective genetic algorithm NSGAII is used to optimize the configuration of the robotic arm.For the space welding task,the mechanical arm configuration is optimized,two robot arms with different degrees of freedom are obtained,the working space analysis is performed on the two optimized robot arms,and the five degrees of freedom robot arm is selected as the welding robot arm.Finally,a five-degree-of-freedom welding manipulator kinematics model is established,and the analytical inverse solution of the manipulator is obtained,combined with fifth-degree polynomial interpolation in joint space and Cartesian space parabolic fitting linear interpolation to perform trajectory planning on the welding manipulator.Matlab was used to verify the trajectory planning results through simulation experiments.The trajectory planning results verified the rationality of the configuration of the welding manipulator and proved the feasibility of the configuration optimization method.