Simplified Sensorless Torque Estimation Method for Harmonic Drive Based Electro-Mechanical Actuator

Torque measurements can significantly enhance control and monitoring loops for many mechatronic aerospace applications. A typical challenge is to justify incorporating a torque sensor in terms of cost, system complexity, reliability. Recently, sensorless estimation methods have been developed robotic joints that include harmonic drive transmissions (HDTs). The principle based on their relatively low torsional stiffness, which allows estimating the transmitted by measuring angles (via existing joint encoders) compliance model. However, these are nonlinear models difficult identify tune. In this study, simplified method introduced structural damping friction HDTs. be correlated HDT using linear dynamic model rate measurements. Experimental results validated proposed method, setup with an external has previously utilized testing several methods.