Sensorless Torque Control for a Robot with Harmonic Drive Reducers

Abstract

The paper presents the implementation of a sensorless torque control algorithm using a friction model developed for the Harmonic Drive (HD) reducers based on experiments. The friction model is developed to account for the temperature variation inside the gear, speed, type of bearing, amount and type of lubricant, etc. The objective is to develop the friction model, which can be obtained based on catalog data, without the need of identification. The model validity and the successful implementation of the sensorless torque control method have been confirmed through simulations and real-time experiments on a 5 d.o.f. chopsticks robot.