Abstract:As the core component for robot posture control, smallsize joints have a direct influence on the robot performance. Hysteresis is a key index characterizing the transmission precision of smallsize joint. Hysteresis measurement and evaluation are the foundation for improving the performance of smallsize joint. Up to now, the hysteresis measurement of smallsize joint is performed mainly based on its main component—reducer. Little research has been done on the overall hysteresis of the smallsize joint. In order to investigate the generation mechanism of total hysteresis of smallsize joint and its basic law, an experiment study on the overall hysteresis of the smallsize joint was conducted based on the developed tester. Based on the analysis on the structural composition of smallsize joint, the composition of total hysteresis and the measurement model, 4 dynamic measurement experiments on smallsize joints A, B and C were conducted. It is found that the geometric hysteresis and elastic hysteresis are the main factors influencing the total hysteresis of the joint. The revolution speed has less influence on the total hysteresis than elastic deformation. Under the conditions of the same load and different revolution speeds, the difference of the measurement results is 005°. It is also found that under certain condition, the dynamic hysteresis and load of the joint show an approximate linear relationship. Finally, a static measurement experiment on the total hysteresis of the joint was conducted, and the result was compared with that for dynamic measurement experiment. It is found that the static measurement result is less than the dynamic measurement result, and the difference is about 01°. The experiment study on the total hysteresis measurement of smallsize joint in this paper lays a solid foundation for establishing the overall quality evaluation system facing to smallsize joints. .txt