Three-degree-of-freedom Delta Parallel Robot Trajectory Planning And Control

In this paper,kinematics analysis,dynamics modeling and simulation,trajectory planning,and trajectory tracking control are carried out for a three-degree-of-freedom Delta parallel robot,and the co-simulation of MATLAB and ADAMS is conducted.The specific work is as follows:(1)Simplify the structure of the Delta robot by introducing a virtual rod model,establish kinematics equations and derive positive and inverse kinematics solutions,and the correctness of the forward and inverse kinematics analysis is verified by numerical examples.Besides,The Jacobian matrix of the robot is deduced on the basis of component constraints,and the velocity model,the acceleration model,and the possible singularities are analyzed.(2)The virtual mass matrix is calculated by the principle of virtual work and simplified,and the dynamic equation of the robot is obtained;Using SolidWorks to establish the robot physics model and import it into ADAMS,and dynamic simulations of theoretical and mechanical models were performed by Simulink and ADAMS,respectively.The simulation results show that the theoretical dynamics modeling is completely feasible and lays a theoretical foundation for controller co-simulation.(3)Trajectory planning of Delta robots is implemented in joint space and Cartesian space respectively.In joint space,select the fifth-order polynomial to interpolate the joints,and simulate the joint angle,angular velocity,angular acceleration and motion trajectory through the jtraj function in MATLAB;In Cartesian space,select the rounded rectangle of the YOZ plane as the motion path,and the path is segmentally interpolated and the coordinates of each interpolation point are calculated in real time.Finally,the position of the moving platform,joint angular velocity,etc.are simulated by ADAMS.(4)Due to the modeling error between the dynamic model and the actual system,the traditional calculated torque method cannot be decoupled accurately.Therefore,based on this,a computational torque controller with fuzzy neural network is proposed and the trajectory tracking control experiment is carried out.The Delta robot model is divided into the nominal model part and the uncertain part.The fuzzy parameter calculation method is used to control the parameter self-tuning of the nominal model.The uncertain part such as modeling error and external disturbance is compensated by the neural network for torque compensation.Finally,Co-simulation experiment is performed by Simulink and ADAMS.The simulation results show that compared with the traditional controller,the proposed fuzzy neural network controller has better tracking performance and anti-interference ability.