Research On Robot's Trajectory Planning And Simulation Based On Virtual Prototype Technology

Robot is one of the human great inventions.The naissance of robot and the foundation of robotics are unsuspicious momentous achievements of human science and technology in 20th century.The application of the robot affects human life and society advancement enormously.It is predicted that,with the incessant development of robotics,robot would be more and more important to humanity.At present,most of the robots are utilized to produce in field of industry.The kinematics and dynamics are questions for discussion in the robot techniques and in the study of the robot.So far,they have been far-flung studied.The study of them has great means in the design of robot's machine and in it's control system.The foundation of the robot's kinetic and dynamical modeling is important in it's analysis of kinamatics and dynamatics.It great matters to robot control,dynamic characteristic and the optimization of the dynamitics. In the dissertation,the author has set up the coordinate of the KUKA240-2 robot machine's links,and then taken homogeneous transformation of coordinate frame theory and matrix theory as the foundation to study the positive kinematics of the robot and found its kinematic model by Denavit-Hartenberg method.Furthermore,the author has searched its negative kinematics,and gived one method about how to choose one appropriate result in allusion to the negative kinematics,which brings eight results.Then,general problem in robot trajectory planning are analyzed.In joint space,cubic trajectories,high-order polynomial trajectories and linear trajectories which is ioined by the parabola is detailed account separately at different situations.In Cartesian space,linear trajectories and arc trajectories are discussed deeply.Then the advantages and disadvantages of trajectories in joint space and Cartesian space are compared.The paper studied the Algorithm of B-splines.On this basis,fourth-order quasis-uniform B-splines is adopted to construct trajectory.The study of robot trajectory planning makes the base of the research on robot's kinematics and dynamics.The paper utilizes ADAMS virtual prototype technology to carry out the kinetic simulation of the robot system.Firstly,it build 3D solid assembly model of the KUKA240-2 robot in CATIA.Certain parts are simplified and united to facilite later simulation,so that virtual model has the same structural,kinematic and dynamic characteristics with the real prototype.Then,the assembly model is imported into ADAMS in *.stl format.Define the key parameters of mass,intertia and CM(center of mass) to certain parts.Define constraints,and relevant motion functions.The papergived one drive function based on the B spline which comes from the trajectory planning to the motion of every joint in the robot model,and start the simulation. To be compared,the paper gived the STEPfunction to the motion to see the difference.The main intention of the simulation is to study the diversification of main kinematic indexes,such as the angle displacement,the angle velocity and the angle acceleration of joint,the displacement,the velocity and the acceleration of the last part and so on.The simulation can not only reflects distinctly the robot link's movement state,which can provide simulation gist for real robot application,but also measure expediently the robot's parameters by right of powerful measure and analysis function of ADAMS,which is very useful to study robot's kinematic and dynamic characteristics,so much as improve on configuration and capabilitity.In the study of dynamics model and the simulation,the industrial robot's dynamics is a complicated system.The robot is composed of many components and many joints.The model has many inputs and out puts.The model has severe coupling and nonlinear problems.The Newton-Euler equation is adopted among some adoptable methods.Based on the homogenous coordinate and homogenous coordinate transformation of the mateices theory and the Newton-Euler equation,the dynamics model is established.Base on the Newton-Euler equation,the recursive answer to dynamic problem and inverse problem are established.SimMechanics is one module of MATLAB/Simulink.It can simulate the translation and rotationed motion of 3D model,afford a series of tools to solve the mechanism motion problem with statics constrainted and coordinate system changed,and give the animation view by its virtual reality tool box.The paper builded the dynamical model by SimMechanics,based on the Newton-Euler equation.Then the paper start the dynamical simulation to get driving torques to the robot's joints,under the cases of no stree on the endmost link. The study to robot's dynamics is benefical to robot control ,and it is important foundation for the next study on robot's dynamic behaviour comprised of the precision,the duplication capacity,the stability and the space definition.The paper also uses ADAMS/Control module and MATLAB/Simulink module to make initial study on the method of dymaically control simulation.Mainly with the aid of virtual prototype technology,the paper build the kinetic and dynamical model,and do the simulation both of kinamtic and dynamtic on the foundation of the trajectory planning,and it has been of great reference value to more in-depth study on the robot simulation and dymically control.