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The exact analysis of the piezoelectric motor has been impossible to the present time, although many researchers have proposed various kinds of analysis method for the piezoelectric motor using numerical method or analytic method. Also, the arranged design method has not been suggested for the Ultra-Sonic Motor (USM) taking the characteristic into account. In order to address these problems, we propose the analysis and design method for the USM using analytic method combined with numerical method. This method was named as the Cutting Method (CM) in this paper. The 8.5[mm] diameter Rotary Ultra-Sonic Motor (RUSM) is developed using the CM to verify the suggested method and for the demand of small actuators in industry. Finally, the proposed analysis and design method was validated by comparing its outcomes with the experimental data. For the vibrator of the proposed 8.5[mm] diameter RUSM, four kinds of comb-tooth structures were prototyped in this research. Hence, the relation between the speed of the motor and the number of teeth is revealed for the first time. This is noteworthy because the tooth design method has not been proposed and because this result also verified the proposed CM.

In this paper, we report on our study of a Nano Positioning Actuator (NPA), which uses an impact/inchworm mechanism. Many kinds of similar precise positioning actuators, which use the same working mechanism, are being and have been proposed by many researchers for several decades. But, the characteristic analysis and design method of the NPA has not been proposed yet. Also, the characteristic analysis and design methods of similar machines were approximate and ineffective. Hence, we present in this paper an analysis methodology for the NPA using the 3D FEM combined with an analytic method, shedding light on the complex working mechanism, and taking all effective components into consideration for an exact and effective characteristic analysis of the NPA and similar machines. In this study, the mechanical system and the driving circuit of an NPA were prototyped. Finally, the effectiveness of an NPA, the reasonableness of a clarified complex working mechanism, and the adequacy of the proposed analysis method were validated by experimental data.

Until now, Ultrasonic Motor (USM) have been designed by using some simple analytic equations or the trial and error method. Therefore, existent design methods of the USM have the problems such as the inaccuracy and the inefficiency. For the solution of these problems, we propose the optimal design methodology of a USM by using the Evolution Strategy (ES) and the Finite Element Method (FEM). The L1B4 USM is designed optimally by using proposed optimal design methodology.

The ultrasonic motor (USM) has many merits for use in a robot arm application. Therefore, the disk-type traveling wave B14 rotary ultrasonic motor (RUSM) is proposed in this paper for that application. Up to the present time, the analysis and design of the USM have been almost always performed using rough analytic methods or using commercial analysis tools. As a result, it was impossible to achieve an exact analysis and design of the USM. In order to address this problem, this paper proposes the analysis and design methodology of the B14 RUSM using a numerical method (3-D FEM) combined with an analytic method taking the contact mechanism into consideration in a linear operation. This methodology is applicable to many other kinds of USMs that use similar mechanisms. In addition, the mechanical system and the driving circuit of the B14 RUSM are designed and prototyped. Finally, the proposed analysis and design methodology is validated by comparing its outcomes with the experimental data. Also, the appropriateness of the suggested RUSM for the application of a robot arm was verified

Analysis of heat problem and temperature field of a piezoelectric transformer, operated at steady-state conditions, is described. The resonance frequency of the transformer is calculated from impedance and electrical gain analysis using a finite-element method. Mechanical displacement and electric potential of the transformer at the calculated resonance frequency are used to calculate the loss distribution of the transformer. Temperature distribution using discretized heat transfer equation is calculated from the obtained losses of the transformer. Properties of the piezoelectric material, dependent on the temperature field, are measured to recalculate the losses, temperature distribution, and new resonance characteristics of the transformer. Iterative method is adopted to recalculate the losses and resonance frequency due to the changes of the material constants from temperature increase. Computed temperature distributions and new resonance characteristics of the transformer at steady-state temperature are verified by comparison with experimental results.

Up to the present time, the analysis and design of ultrasonic motors (USMs) have been performed using rough analytic methods or commercial analysis tools without considering the complex contact mechanisms. As a result, it was impossible to achieve an exact analysis and design of a USM. In order to address the problem, we proposed the analysis and design methodology of an L1B4 USM using a three-dimensional finite element method combined with an analytic method that considers complex contact mechanisms in linear operation. This methodology is applicable to many other kinds of USMs which use resonance modes and contact mechanisms. Also, we designed and prototyped the mechanical system and driving circuit of the LlB4 USM, and finally validated the proposed analysis and design methodology by comparing their outcomes with experimental data.

In this paper, a fast inversion scheme for piezoelectric constants of piezoelectric transformer is proposed. The effects of material coefficients on piezoelectric transformers are investigated by using three-dimensional finite element method (FEM) which is confirmed experimentally. A design sensitivity method adopted as an inversion scheme and Asymptotic Waveform Evaluation (AWE) is used for fast frequency sweep.

In this paper, the three-dimensional finite element method and construction of an equivalent-circuit for the linear ultrasonic motor, is presented. The validity of the three-dimensional finite element routine in this paper is experimentally confirmed by analyzing the impedance of a piezoelectric transducer. Using this confirmed finite element routine, the impedance and vibration mode of a linear ultrasonic motor are calculated. Elliptical motion of the contact point between vibrator and rail of a linear ultrasonic motor is shown for determination of the contact point. Using the finite element method and analytic equations, characteristics of linear ultrasonic motor, such as thrust force, speed, losses, power and efficiency, are calculated. And the results are confirmed by experiment. Finally, equivalent circuit parameters of the linear ultrasonic motor are obtained by three-dimensional finite element method and analytic equations.

In this paper, an inversion scheme for piezoelectric constants of piezoelectric transformers is proposed. The impedance of piezoelectric transducers is calculated using a three-dimensional finite element method. The validity of this is confirmed experimentally. The effects of material coefficients on piezoelectric transformers are investigated numerically. Six material coefficient variables for piezoelectric transformers were selected, and a design sensitivity method was adopted as an inversion scheme. The validity of the proposed method was confirmed by step-up ratio calculations. The proposed method is applied to the analysis of a sample piezoelectric transformer, and its resonance characteristics are obtained by numerically combined equivalent circuit method.

A characteristic analysis of an ultrasonic motor (USM) at the design stage has thus far been impossible. Therefore, a characteristic analysis method is suggested on the basis of a proposed model describing the complex nonlinear contact condition between the rotor and stator. The proposed contact model and analysis method can guide theoretical research on the minimization of the main disadvantages of the USM, which mainly result from the contact mechanism. The validity and usefulness of the suggested analysis method is verified by experimental data from a prototyped USM.

In this paper, we report on our study of a nanopositioning actuator (NPA), which uses an impact/inchworm mechanism. Various kinds of similar precise positioning actuators, which use the same working mechanism, have been proposed by many researchers for several decades. However, characteristic analysis and design methods for the NPA have not been proposed yet. Moreover, the characteristic analysis and design methods for similar actuators were approximate and inefficient. Hence, this paper presents an analysis method for the NPA, which is based on a combination of numerical and analytic methods, shedding light on the complex working mechanism and taking significant factors in the analysis into consideration for an exact and efficient characteristic analysis of the NPA and similar machines. In the present study, the mechanical and electrical systems of the NPA were prototyped. Finally, the effectiveness of the NPA, the feasibility of the clarified complex working mechanism, and the adequacy of the proposed analysis method were verified by experiments.