A novel hybrid self-sensing method for force estimation in a piezo-stepper actuator

Abstract

This paper presents a novel application of a hybrid observer based self-sensing in a piezo stepperactuator. Most existing observer based methods for force estimation are based on the assumption of smooth external loading conditions and do not take into accountthe interactions due to contact. While stepping athigh frequencies, a proper interaction between the driving rod and piezolegs of the piezo-stepper is not achieved causing unwanted disturbances. In this paper, a hybrid method incorporating selfsensing contact detection and observer based self-sensing is used to estimate the force acting on the piezolegs. The designed hybrid observer is able to identify contact and estimate forces with a good accuracy for the given driving signal.