Kinematic Analysis Of A Heavy Load Casting Robot

At present,China's foundry industry technology level and production efficiency are low,the environmental pollution is serious and the working environment is bad,there is a lot of noise,oil pollution and dust in the working site.With the development of automation and robotics,industrial robots have been widely used in transportation,welding and stacking.Casting robots can improve the production efficiency,precision and quality of casting,can withstand harsh working conditions,and they can save labor force and realize the automation of casting production.The kinematics analysis is an important part in the development of the casting robot,which provides a theoretical basis for the robot dynamics analysis and the development of control system.This article took the preliminary design of the structural model of the heavy load casting robot with hybrid structure as the research object.Firstly,the structure and working principle of the robot were briefly analyzed and the degree of freedom of the parallel mechanism of the robot was analyzed based on the spiral theory.After that,a suitable coordinate system was established for each part of the robot mechanism model.According to the coordinate transformation theory,the relationship between the pose of the ladle end effector and the pose of each driving element were deduced,and the inverse solution model of robot was established.According to the inverse solution model of pose,the first order movement influence coefficient and second order movement influence coefficient of casting robots were solved.Then according to the kinematic influence coefficient,the relationship of velocity and acceleration between pouring ladle and driving elements were calculated,the speed model and acceleration model of robot were established.Finally,the robot structure model in the Solidworks software was imported into the motion simulation software ADAMS,and the corresponding constraints and drivers were added to establish the virtual prototype of the casting robot.The kinematics simulation of casting robot was competed in ADAMS,then extract the pose,velocity and acceleration of pouring ladle as known conditions to calculate the pose,velocity and acceleration of driving elements.The simulation data was compared with the theoretical data,the difference diagram of the two data was drawn,and the reason of the error was analyzed,so as to verify the correctness of the kinematic analysis of the casting robot.