Analysis and Prediction of Transmission Error of Harmonic Reducer for Space Robot

During operation of the space robot joint, there are periodic changes in the load and speed of the harmonic reducer. Because the flexspline is a flexible mechanism, the transmission error of the harmonic reducer is related not only to manufacturing but also to load. The key to improve the precision of harmonic reducer is to reveal the relationship between transmission accuracy and load. In this paper, considering the influence of internal friction and external load, the prediction model is established for transmission error of harmonic reducer. The model has been optimized considering the load fluctuations and sudden changes during operation. The influence of load and speed is discussed on the transmission error. The influence of load on transmission error is more serious. The model can predict the transmission error of the harmonic reducer under variable speed and load. The results show that the transmission error in the operating state is much larger than the transmission error in the stable operation. The accuracy of stable transmission error, operational transmission error, and dynamic lost motion is more than 90%. The research will provide an effective reference for the high-precision operation of space robot.