A novel three-phase excitation piezoelectric motor for macro-micro actuation: integration design, systematic modeling, and experimental evaluation

Macro-micro actuators require complex feedback control systems to obtain high positioning cooperativeness. However, the mechanical connections of macro-micro actuators are generally redundant in terms of their size, which is highly unfavorable for both miniaturization and integration. This paper presents an approach to address this problem based on a novel integration design for a three-phase excitation piezoelectric motor (TPM) that is capable of performing macro-micro actuation by switching its operating mode from resonant to nonresonant. The load capacity of the proposed TPM can reach 0.39 Nm with a maximum speed of 3.82 rad s(-1) (36.5 rpm). This performance is achieved by using a unique triangular flexible stator that contains three piezoelectric stack actuators acting as vibrators and is excited by a three-phase electrical signal. A time-domain electromechanical coupling dynamic model is developed to determine the dynamic behavior of the proposed motor, and the modeling results are validated successfully by experimental results obtained from a fabricated prototype. The proposed motor is expected to be helpful for integration design of piezoelectric devices that require macro-micro actuation.