Abstract:

In order to achieve torque measurements of harmonic drive in space robots, the build-in torque sensor for harmonic drive is researched in this paper, and the measurements of the flexspline′s strain are used to calculate the output torque. The transient dynamics of harmonic drive is analyzed by using the finite element method, and then the analysis result of the flexspline′s dynamic strain is used for the design and optimization of the torque sensor. Simulation results show the root mean square error of torque measurements is 1.6%, and the steady-state measuring accuracy is 2% and 0.5% before and after low-pass filtering respectively, which can meet the requirements for torque measurements.

Key words: Harmonic drive, Torque measurement technique, Dynamic strain, Finite element method