A Novel Three-Degree-of-Freedom Linear Resonant Actuator and Its Control Method

In this study, a novel actuator with a symmetrical structure is presented. The directional linear resonant motion with a three-degree-of-freedom is achieved by symmetrically arranging the four-phase coils and magnets in space. In order to control the various linear motions of the proposed actuator, a transformation matrix that transforms the stationary reference frame by four-phase axes into the orthogonal reference frame in space is introduced. It also describes how to estimate and control the stroke of the proposed actuator in the orthogonal reference frame. The parameter characteristics of the actuator are analyzed through finite element analysis (FEA). Finally, the effectiveness of the estimation and control methods is verified by using dynamic simulation.