The Design And Study Of 6 Degree Of Freedom Manipulator Structure Based On The Dual Motor Anti-backlash

Many kinds of processing equipment such as industrial robots and lathe using gear or worm gear as their transmission system to transfer speed and torque,in the process of tooth mesh there must be gaps between tooth space to form oil film between the tooth profile,so the transmission gap is inevitable,but the existence of transmission clearance increases the impact load,there will make bad impact on the CNC engraving,cutting and other need accurate positioning precision motion,at the same time,at the instant of the transmission system doing positive and negative motion the transmission clearance affect the accuracy of system,causing graphics distortion and poor control precision.Anyhow,transmission clearance is an important factor on restricting the transmission precision and machining accuracy of machine tool,eliminate transmission clearance has important theoretical value and practical significance.The control method of Dual motor drive torque compensation has been proved to be reliable to eliminate the backlash.This thesis apply the principle of dual motor driven backlash to a 6 degree of freedom manipulator design and designed a new type of manipulator.The main content of the thesis are as follows:(1)Make a briefly introduction to the basic principle of dual motor backlash and the method of dual motor backlash.(2)Reference the domestic and overseas design index of manipulator,designed the structure of base,shoulder,elbow,wrist of the manipulator respectively.Among them,both base and shoulder joint has one degree of freedom,elbow and wrist joints using the differential transmission way to realize two degrees of freedom.Base and shoulder joint part was driven by two servo motors respectively at the same time,the elbow and wrist joints part was driven by four electric servos motor respectively.Every joint uses worm gear and worm as their drive mechanism.(3)Simplify the mechanical model,in accordance with the designed size structure and load conditions of the model to estimate the joint torque,then determine the output power of each joint,select the required model servo motor of each joint and the driver to match with motor in the finally;Using the Matlab software to make a modeling of the method of three kinds of connections between manipulator terminal and drilling actuator,analysed the influence of the different installing method on the operability of the manipulator,select suitable way to install drilling actuator on the manipulator designed by this thesis.(4)Using standard method of D-H modeling derived the position equation of 6 degree of freedom manipulator drived by dual motor.(5)Using Ansys Workbench software for finite element analysis for the joints of the manipulator respectively,when the structure of manipulator worked under load,the stress state and variable will not affect the overall accuracy of manipulator.