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The piezoelectric actuator is applied in a micro forging system which was designed specially by maximizing its structural rigidity to study size effects in micro forming. To generate accurate movement in micrometer/nanometer scale, a dynamical model of the piezoelectric actuator is in need. High accuracy of micro/nanometer scale manufacturing is required in the miniaturization of various applications such as high precision optical systems, and high accuracy positioning. The models for the Piezoelectric Inertia Friction Actuators (PIFAs) were used for the optimization of PIFA performance. In this paper, the critical challenges are first identified in control of PIFAs. Second, a general architecture of PIFAs is proposed to facilitate the analysis and classification of the literature regarding modeling and control of PIFAs. This general architecture covers all types of PIFAs and thus serves as a general conceptual model of PIFAs.

The bond graph approach which considers the effect of multi-degree-of-freedom loading structures on the dynamics of the actuators is proposed in this paper. We try to fuse the new model with the bond graph control techniques, where the unknown parameters in the model are not needed to be identified. The control algorithm guarantees the stability of system. The challenges associated with the control problem are also discussed.

The decoupled structure PIFA models have the advantages of being more accurate and flexible as compared to the decoupled ones. Among the existing hysteresis sub-models, for a tractable among of computation efforts, a contradiction between the capability of representing all hysteresis phenomena and maintaining model accuracy remains to be solved.

The bond graph control is among the most promising ones as applied to PIFA positioning since when designed based on the decoupled structure PIFA models, it can completely reject the hysteresis and creep effects in theory. The bond graph control laws are usually simple and of a proportional type. The dynamic model is used mostly for the purpose of compensation, especially compensating for the hysteresis of the Piezoelectric Actuators material. Such a bond graph control is not quite robust and does not adequately address the highly uncertain dynamics of PIFAs.