Research And Design Of Three-degree-of-freedom Delta Robot Control System

The parallel robot has the characteristics of fast speed,high precision and strong rigidity.It is widely used in the field of industrial automation,especially in light industry,food,medicine,logistics,packaging and other industries.High-speed parallel robots can replace the manual work of single and repetitive tasks,such as sorting,inserting and packaging.At the same time,it can overcome the disadvantages such as pollution,inefficiency and high cost caused by manual operation.In view of the rapid growth of the application of high-speed parallel robots,the three-degree-of-freedom delta parallel robot is used for the theoretical research and simulation verification.This paper mainly focuses on:(1)The kinematics model of the Delta robot is simplified and established.The mechanism constraint relation is analyzed and the positive and negative solution of the motion position of the robot is obtained.Based on this,the terminal velocity acceleration and Jacobian matrix of Delta robot are deduced.According to the theory of robot dynamics,the mass inertia matrix of each mechanism is calculated by kinetic energy theorem,and the dynamic model of the Delta robot is obtained by using the principle of virtual work.(2)Based on the actual operation demand of Delta robot,two improved motion planning methods are proposed.One is to improve the modified trapezoidal acceleration method to realize the rectangular path planning.Compared with the unimproved modified trapezoidal acceleration method,the end of the Delta robot has no mutation at beginning and the end of the movement.The end impact of the robot is reduced.The other is in the path of the PH curve,which is a higher order of 4-5-6-7 polynomials,and the trajectory is smoother and shorter.For example,a 100mm×400mm×100mm of the "door" type space to calculate the running period of two kinds of motion planning.At the same time,we use SolidWorks software to create the Delta robot model and import ADAMS virtual prototype to simulate.By comparing the two trajectory planning parameters curves,it is concluded that the PH curve planning is a better method for the motion planning.(3)A method of calculating torque control based on dynamic model is designed.Using Simulink in MATLAB to build the simulation platform,and associated with ADAMS simulation to verify the rationality of the controller with optimal benign.According to the simulation results,the objective optimization function is proposed tooptimize the control parameters.