Abstract
Recently, linear resonant actuators (LRAs) have been used in a wide range of applications since they have many advantages: high efficiency, simple structure, easy control, and so on. On the other hand, they have a problem in that the amplitude decreases significantly in response to an external load. To overcome this problem, the effectiveness of PID control using back electromotive force (EMF) in maintaining a constant amplitude against an external load is investigated.
This paper proposes a numerical method involving the use of the 3-D finite element method to analyze the dynamic characteristics of LRA when it is operated under PID control in PWM feedback control by using the back EMF detected from a coil. The effectiveness of this method is shown through measurements obtained by using a prototype.
