The Research And Design On Trajectory Planning And Control Method Of SCARA Robot

SCARA robot is a kind of selective compliance assembly robot arm,which has great flexibility in the plane and strong rigidity in the vertical direction,so SCARA robot is widely used in industrial automation.With the development of the robot in the country put in the national level and the rapid development of the manufacturing industry,higher requirements for control speed,control precision and stability are put forward.In this paper,SCARA robot is taken as the research object.The robot kinematics and dynamics analysis,robot trajectory planning in joint space are carried out.The controller for two degrees of freedom(DOF)SCARA robot based on back-stepping control and port controlled Hamiltonian with dissipative(PCHD)control are designed.And the hybrid control is designed according to the simulation results of the two control methods.Firstly,the link model of SCARA robot is established,and the forward and inverse kinematics of SCARA robot are deduced.The correctness of kinematics coordinate system is verified by using the robot toolbox in MATLAB.And the singularity of robot is analyzed by using the simplified Jacobian matrix.Secondly,the model of 4-DOF SCARA robot is established in ADAMS,and the constraint,friction and motion are added to the model.The correctness of the model simplification is verified by comparing the torque of joints before and after simplification.The dynamics equation of 2-DOF SCARA robot is deduced by using the Lagrange method,and the co-simulation is established by using ADAMS / Control module in order to achieve the exchange of data between the ADAMS and MATLAB.Then trajectory planning of SCARA robot is carried out in joint space in order to make joints run smoothly.With the principle of high efficiency and practicality,the trajectory planning in joint space for single-node and multi-node is carried out with the use of cubic polynomial interpolation,quintic polynomial interpolation and cubic spline interpolation.Finally,the 2-DOF SCARA robot is taken as the research object,and the controller based on back-stepping method and the controller based on PCHD are designed.The stability analysis of controllers are carried out and the co-simulation systems are built and carried out in MATLAB.According to the simulation result of the two single-control methods,hybrid control strategy is designed,so that the two single-control methods can ful y play its role in the corresponding time.The effectiveness and correctness of the hybrid control are verified by simulation experiments,the hybrid control system has good dynamic and steady-state performance,and has strong robustness,which meets design requirements.