Design And Implementation Of Polishing Robot Based On Six-axis Force/Torque Sensor

With the acceleration of the national industrialization process and the progress of science and technology,the field of manufacturing has been developing continuously and the degree of automation has been greatly improved.Polishing the wheel hubs artificially has the disadvantages of poor quality,low efficiency,which restricting the development of wheel manufacturing technology.The research focuses on the key technologies of polishing the wheel hubs automatically.A polishing robot is developed based on a six-axis force/torque sensor.It finishes the polishing work of wheel hubs automatically.Firstly,a research of the structure parameters of the wheel hubs is done to analyze the manufacturing method and the polishing process.A case study of wheel hub s' polishing work in Kunshan Liufeng Machinery Industry Co.,Ltd is done to parameterize the wheel hub's polishing process.According to the work requirements and design requirements,the research designs a set of 5 degrees of freedom polishing robot based on the six-axis force/torque sensor.It consists of horizontal mobile platform,polishing manipulator,six-axis force/torque sensor,lifting platform,pneumatic grippers and robot bracket and so on.Meanwhile,the forward kinematics model of the polishing robot is established.Based on the Monte Carlo method,the effective polishing workspace and the boundary are calculated.Furthermore,the modal analysis is presented on the polishing robot to obtain the natural frequencies and main modes,which provides a guide for optimization of robot's structure design.To obtain the force information during the polishing process,a six-axis force/torque sensor with overload protection is designed.Based on the principles of force measurement of one-dimensional force measuring element,the structure of the elastomer is designed.The force decoupling is realized using sliding shaft.The flange structure is applied to protect the elastomer from deformation failure.Then,the hardware and software platforms are built.It realizes the data acquisition and processing.The calibration system is built and the mechanism is designed based on lever-toggle to calibrate the sensor.Furthermore,the performance of the sensor is evaluated,including linearity,sensitivity,hysterisis error and repeatability.Its efficiency and reliability are proved by experiments.Finally,with the results of the experiments carried out on the platform,the application of the polishing robot is studied.The experimental data of polishing force and the polishing quality of the aluminum alloy wheel hubs are analyzed to prove the effectiveness of the polishing robot.