Efficient charge recovery method for driving piezoelectric actuators with quasi-square waves

In this paper, an efficient charge recovery method for driving piezoelectric actuators with low frequency square waves in low-power applications such as mobile microrobots is investigated. Efficiency issues related to periodic mechanical work of the actuators and the relationship among the driving electronics efficiency, the piezoelectric coupling factor, and the actuator energy transmission coefficient are discussed. The proposed charge recovery method exploiting the energy transfer between an inductor and a general capacitive load is compared with existing techniques that lead to inherent inefficiencies. A charge recovery method is then applied to piezoelectric actuators, especially to bimorph ones. Unitary efficiency can be obtained theoretically for purely capacitive loads while intrinsic losses such as hysteresis necessarily lower the efficiency. In order to show the validity of the method, a prototype driving electronics consisting of an extended H-bridge is constructed and tested by experiments and simulations. Preliminary results show that 75% of charge (i.e., more than 56% of energy) can be recovered for bending actuators such as bimorphs without any component optimization at low fields.

[1]  Ronald S. Fearing,et al.  Wing transmission for a micromechanical flying insect , 2000, Proceedings 2000 ICRA. Millennium Conference. IEEE International Conference on Robotics and Automation. Symposia Proceedings (Cat. No.00CH37065).

[2]  K. Agbossou,et al.  Class D amplifier for a power piezoelectric load , 2000, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[3]  D. Ruffieux,et al.  An AlN piezoelectric microactuator array , 2000, Proceedings IEEE Thirteenth Annual International Conference on Micro Electro Mechanical Systems (Cat. No.00CH36308).

[4]  Abraham Pressman,et al.  Switching Power Supply Design , 1997 .

[5]  Michael Goldfarb,et al.  Modeling Piezoelectric Stack Actuators for Control of Mlcromanlpulatlon , 2022 .

[6]  H. Katz,et al.  Solid state magnetic and dielectric devices , 1959 .

[7]  J. G. Smits,et al.  Dynamic admittance matrix of piezoelectric cantilever bimorphs , 1994 .

[8]  William C. Athas,et al.  An energy-efficient CMOS line driver using adiabatic switching , 1994, Proceedings of 4th Great Lakes Symposium on VLSI.

[9]  Nestoras Tzartzanis,et al.  Low-power digital systems based on adiabatic-switching principles , 1994, IEEE Trans. Very Large Scale Integr. Syst..

[10]  Ronald S. Fearing,et al.  Development of PZT and PZN-PT based unimorph actuators for micromechanical flapping mechanisms , 2001, Proceedings 2001 ICRA. IEEE International Conference on Robotics and Automation (Cat. No.01CH37164).

[11]  Seth R. Sanders,et al.  Fundamental limits on energy transfer and circuit considerations for piezoelectric transformers , 1998 .

[12]  L. E. Cross,et al.  Electromechanical coupling and output efficiency of piezoelectric bending actuators , 1999, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[13]  Kenji Uchino,et al.  Piezoelectric Actuators and Ultrasonic Motors , 1996 .

[14]  Ephrahim Garcia,et al.  Efficient power amplifiers for piezoelectric applications , 1996 .