New approach for modeling and testing of harmonic drive in robotic systems

Harmonic drives are becoming a key component in advanced robotic systems. The complicated dynamic behavior of the harmonic drive is due to the nonlinear torsional stiffness and hysteresis. Traditional modeling methods capture the behavior patterns of the harmonic drive by treating it as a black box in the experiments. This paper provides a new dynamic modeling method which takes into consideration component interactions inside the harmonic drive. In addition an innovative method for testing the performance of the drive is devised. Based on this new method, we have developed a testing station and performed experiments on a real harmonic drive which is used in the Hubo+ humanoid robot. The testing results have verified the new modeling and testing method.