Amplitude Control for Linear Resonance Actuator Using Sensorless Load Estimation Method

Abstract

Linear resonance actuators (LRAs) have high efficiency and are small in size, and they are expected to be applied to industrial applications. The amplitude of an LRA changes with an external load therefore, the compensation for load is essential. We have proposed an amplitude control method by using a back-EMF. However, it has two problems: the low responsiveness in the transient state and the amplitude variation in the steady state. To address these problems, we proposed our method with a sensorless load estimation method based on energy conservation law. This study clarifies that the method can improve the responsiveness and amplitude variation.