Piezoelectric Motor Research Articles

An inverse kinematic analysis modeling on a 6-PSS compliant parallel platform for optoelectronic packaging

Multiple degree of freedom motion platform is always one of the important components in optoelectronic packaging systems, its characteristics have a vital impact on the performances of optoelectronic packaging. This paper presents a 6-Prismatic-Spherical-Spherical compliant parallel platform for optoelectronic packaging. This platform is a kind of parallel layout structure, which uses the piezoelectric motors as active joints and the large-stroke flexure hinges are employed as passive joints. An inverse kinematic modeling based on elastokinematic analysis is analyzed and deduced. The elastokinematic analysis considers the elastic deformation of the large-stroke flexure hinges in movement process, and improves the positioning accuracy of the compliant parallel platform in applications. The finite element analysis model and the prototype of the compliant parallel platform are developed, and the validity of the proposed method is finally verified. This paper provides a theoretical reference and experimental data for the inverse kinematic analysis of six degrees of freedom motion compliant parallel platforms with large-stroke flexure hinges.

Beam Scanning of Silicon Lens Antennas Using Integrated Piezomotors at Submillimeter Wavelengths

This paper presents a lens antenna that scans the beam using an integrated piezomotor at submillimeter-wave frequencies. The lens antenna is based on the concept presented by Llombart et al. in 2011, a leaky-wave waveguide feed in order to achieve wide angle scanning and seamless integration with the receiver. The lens is translated from the origin of the waveguide producing the scanning of the beam over a 50° field of view (FoV) (or about 6.25 beamwidths) with a maximum scanning loss of 1 dB. The lens movement is achieved with a piezoelectric motor that is integrated within the antenna and receiver block. A prototype was built and measured at 550 GHz achieving scanning beam angles close to 20° with only 0.6 dB of loss. The scanning of the 50° FoV, which corresponds to a lens displacement of approximately 2 mm, takes about 0.9 s achieving a scanning rate of 0.75 Hz of the FoV. The accuracy in continuous mode of the piezoactuator has been measured to be less than 28 μm in the worse of cases for displacements of 2 mm, which corresponds to a beam steering of 0.76°, much smaller than the antenna half-power beamwidth of 8°.

Development of Δ-type Self-propelled Robot Using Standing Wave Type Piezoelectric Ultrasonic Motor

Development of Δ-type Self-propelled Robot Using Standing Wave Type Piezoelectric Ultrasonic Motor

Linear Piezoelectric Motor for Topography Detector of Diamond Wire

In topography detection procedures for diamond wire, precision motion control is one of the key preconditions; the motion control unit of detection needs both micron resolutions and centimeter strokes. In this paper, a linear motor with four sets of multilayer piezoelectric actuators was developed to achieve an actuator with high resolution and a large stroke. The stroke depended on the guideways of the system, which mar enlarged the stroke of a single multilayer piezoelectric actuator. The mechanism of differential actuation was analyzed by dividing an operation cycle into several states. A symmetrically arranged four-foot design was proposed, and a corresponding excitation method was devised. A prototype was fabricated to conduct a proof-of-concept operation test. Experimental results validated the feasibility of the prototype with a 10 mm stroke. The speed of the prototype increased when the amplitudes of driving voltage signals increased from 30 V to 100 V. Within the frequency range of 1 Hz to 120 Hz, the speed increased initially then decreased with driving frequency, the maximum of which was at 100 Hz. With an excitation voltage signal of 100 V and 100 Hz, the speed reached a maximum of 740 μm/s. With an excitation voltage signal of 30 V and 120 Hz, the resolution of the prototype reached 0.26 μm. The prototype satisfies precision motion control of topography detection for diamond wire. This work also provides an option for automatic systems that require high resolutions and large strokes.

Alignment of distributed oscillation systems in piezo motors

The pressing problem in the space domain is the development of large-sized reflectors for spacecrafts. The specified criteria for reflector structure are precise reflector surface shape and structure mass. Precise reflector surface shape during long-term performance is provided by the alignment of piezoelectric motors used in the reflector structure. These motors exhibit both limited mass-dimensional coefficient and can produce high force. Piezo-motor is distributed mechanical – acoustic oscillation system. In the piezo-motor mechanical – acoustic oscillation is generated by PZT-stack being transferred to the oscillator then to the load action element.The objective of the work is the study the alignment of distributed oscillation systems in piezo-motors. The novelty of the work is using the alignment of oscillator impedance and load impedance to determine the performance resonance frequency of distributed oscillation system in piezo-motor. This method simplifies the possibility of analyzing distributed in piezo-motor oscillation system characteristics. The method was tested under different in piezo-motor load modes.

Basics of the electropiezoelasticity theory of piezoelectric motors with linear and rotary motion

The paper presents the basics of the theory of electropiezoelasticity and adaptation of this theory to description of the simplest electromechanical converters − piezoelectric type electric motors. Because piezoelectricity and elasticity are coupled by complex piezoelasticity constitutive compounds, the formulation of a general mathematical model for these motors is not possible. Therefore, equations for structurally simple piezoelectric motors with linear and rotational motion have been formulated in the paper. Motors with linear movement are characterized by a flat or tube form. Rotary motors, on the other hand, have a cylindrical or disc-shaped form. The electric field, in the adopted forms of piezoelectric motors generating a piezoelectric effect, is a single-field perpendicular to the direction of motion. The determined equations could be simplified by reduction of some constitutive parameters, but it requires a detailed analysis of material compounds and consideration in the interactions of forces and torques in these motors, also strong piezoelectric stresses, which determine a specific kinetics. Keywords: piezoelectric motors with translational and rotary motion, equations of electric-piezoelasticity.

Note: Low sliding friction piezoelectric motor using motion of hula hoop.

A piezoelectric motor that imitates the motion of a hula hoop was developed. It has the advantage of low sliding wear as static friction force is used to drive the rotor. The rotation speed of the rotor can be regulated by changing the exciting frequency of piezoelectric transducers. The stator is composed of four piezoelectric plates attached to a steel rod. Two orthogonal bending modes were excited by driving two pairs of piezoelectric plates, and circular motion was formed on the rod. The reversed motion of the rotor can be obtained by adjusting the phase of two bending modes. The prototype stator working at 39.1 Hz produced a rotation speed of 1142 rpm and a torque of 0.23 mN m.

Working Mechanism of Nonresonance Friction in Driving Linear Piezoelectric Motors with Rigid Shaking Beam

A kind of nonresonance shaking beam motors is proposed with the advantages of simple structure, easy processing, and low cost due to its wide application prospects in precision positioning technology and precision instruments. The normal vibration model between the stator and slider is divided into contact and noncontact types to investigate the nonresonance friction drive principle for this motor. The microscopic kinematics model for stator protruding section and the interface friction model for motor systems during both operating stages are established. Accordingly, the trajectory of the stator protruding section consists of two different elliptical motions, which differ from those of resonance-type motors. The output characteristic of the nonresonance shaking beam motor is proposed under steady working conditions with reference to the research method of standing-wave-type ultrasonic motors. Numerical analysis is used to simulate the normal vibration and mechanical output characteristics of the motor. Experimental and theoretical data fitting validates the numerical analysis results and allows the future optimization of nonresonance-type motors.

Cowpea-structured PVDF/ZnO nanofibers based flexible self-powered piezoelectric bending motion sensor towards remote control of gestures

Interactive human-machine interface (iHMI) is a bridge connecting human beings and robots, which has an important requirement for perceiving the change of pressure and bending angle. Here, we designed a flexible self-powered piezoelectric sensor (PES) based on the cowpea-structured PVDF/ZnO nanofibers (CPZNs) for remote control of gestures in human-machine interactive system. Due to the synergistic piezoelectric effect of hybrid PVDF/ZnO and the flexibility of polymer, this PES exhibited excellent bending sensitivity of 4.4 mV deg−1 ranging widely from 44° to 122°, fast response time of 76 ms, and good mechanical stability. Besides, the PES could operate under both bending and pressing mode, show ultrahigh pressing sensitivity of 0.33 V kPa−1, with response time of 16 ms. When integrated in iHMI, the PES could be conformably covered on different curve surfaces, demonstrated accurate bending angle recording and fast recognition for realizing intelligent human-machine interaction. On this basis, the application of remote control of robotic hand was successfully realized in form of acting the same gesture as human hand synchronously. This CPZNs-based self-powered PES is distinct and unique in its structure and fundamental mechanism, and exhibits a prospective potential application in iHMI.

Graphene-based optical waveguide tactile sensor for dynamic response

Optical tactile sensors based on a directional coupler have been widely investigated because of their many advantages. However, one important requirement limits their wide application: the refractive index of the upper superstrate must be equal to or larger than that of the optical waveguide core. To overcome this disadvantage, an optical waveguide tactile sensor using graphene is proposed and its operational feasibility was validated experimentally. The pressure-dependent lateral deformation of the low-index prism-like microstructure on an elastomer superstrate has a key role in optically measuring the mechanical pressure. By mechanically varying the lateral deformation area, the waveguide core-graphene-polydimethylsiloxane (PDMS) interface area was adjusted and the amount of light absorption by graphene became tunable, even when the refractive index of the superstrate was lower than that of the waveguide core. The dynamic response of the sensor was accurately matched to the repeated pressing and release time of the pressure, and exhibited a real-time response to multi-stepped mechanical pressing and releasing using a piezoelectric motor. The proposed graphene-based optical tactile sensor is foundational to the use of a wide range of materials for overcoming the shortcoming of a directional coupler-based optical tactile sensor.

Microstructure and physical properties of the multicomponent PZT-type ceramics doped by calcium, sodium, bismuth and cadmium

In this work, the multicomponent Pb(Zr0.58Ti0.42)O3 ceramics doped by calcium (Ca), sodium (Na), bismuth (Bi) and cadmium (Cd) was designed and obtained by the hot uniaxial pressing method. Comprehensive electrophysical properties including crystalline structure, microstructure, dielectric, electromechanical and piezoelectric of the ceramics were made. The Pb0.92Ca0.02Na0.01Bi0.05(Zr0.58Ti0.42)0.98Cd0.02O3 ceramics obtained by the hot uniaxial pressing method has a microstructure of a regularly crystallized grain. The multicomponent material shows high values of dielectric and piezoelectric properties with high ferroelectric hardness. A wide and rectangular hysteresis loop of the PZT-type ceramics shows high ferroelectric hardness of obtained ceramics. Studies have also shown that multicomponent PZT-type ceramics exhibits a strong S–E behavior. The S–E electromechanical loops have characteristic “butterfly wings” shape with high values of mechanical strain. These properties of the obtained material allow its application in the modern microelectronics and micromechatronics, for example, in constructing electromechanical and electroacoustic transducers, piezotransformators, piezoelectric motors, etc.

“Tribological solicitations” of piezoelectric inertia motors by means of in situ tribotesting and 3rd body flow framework

In piezoelectric inertia motors, friction is not a synonymous of energy loss but is the source of motion. Their performances are thus prone to wear and friction coefficient variation. To address these issues, this paper first aims at improving the understanding of tribological solicitations by means of a dedicated in situ tribotesting while exploiting the 3rd body flow framework. Beyond the introduction of transparent glass pins to see inside the contact in operation, the key of this work is to consider both the mechanism effect and the friction couple. As a result, a solution has been proposed to multiply the motor lifetime by more than ten while keeping stable speed performances, and, above all, without multiplying tests with numerous friction materials.

Torque modeling and characteristic analysis of electromagnetic piezoelectric hybrid-driven 3-degree-of-freedom motor

The electromagnetic piezoelectric hybrid-driven 3-degree-of-freedom motor is a new multi-degree-of-freedom motor. To further analyze the torque characteristics of the electromagnetic piezoelectric hybrid-drive 3-degree-of-freedom motor. First, the principle and basic structure of the hybrid-drive motor are introduced, and the displacement and pressure distribution of the stator–rotor contact surface are obtained by analytical method. Based on this, the torque model of the piezoelectric stator-drive motor is obtained. Then, the air-gap magnetic field model of the permanent magnet rotor is obtained by analytical method, and the electromagnetic stator-torque model is obtained. Finally, the torque model of the electromagnetic piezoelectric hybrid-drive 3-degree-of-freedom motor is established by vector synthesis. The effects of piezoelectric stator mounting position angle, stator–rotor contact materials, and preload on motor torque are analyzed by simulation. The advantages of electromagnetic piezoelectric hybrid drive are analyzed, and the rationality of the model is preliminarily verified. It lays the foundation for further optimization design and performance improvement of electromagnetic piezoelectric hybrid-drive 3-degree-of-freedom motor.

Chosen Analysis Results of the Prototype Multicell Piezoelectric Motor

This paper presents the design, modeling, and tests of the prototype multicell piezoelectric motor (MPM). A new concept of the electromechanical structure of the considered prototype is based on three rotating-mode actuators. The electromechanical structure of each actuator has been considered as an independent one—referred to as a “single cell” (single actuator). Combined three resonant actuators generate three traveling waves that as a result improve the stability and performance of the MPM. The results of research carried out using analytical, simulation, and experimental methods cover the torque versus speed characteristics of the prototype MPM.

Light-activated piezoelectric linear motor by using a serial bimorph made of an optopiezoelectric composite

In this paper, we report a new method to activate and control a piezoelectric linear motor using a switching light source through two transparent electrodes and a photoconductive coating. This coating is composed of titanium oxide phthalocyanine (TiOPc), electron transport materials, hole transport materials, and polyvinyl butyral binder. It is used to replace one of the surface electrodes of a piezoelectric serial bimorph to provide an optical interface and to construct an optopiezoelectric composite. The weight percentage of TiOPc nanoparticles, solvent compositions, and film thickness are studied to identify the optimal coating to match the electrical impedance of the piezoelectric serial bimorph in both on and off states. Experimental results show that the photoconductive coating has a good on–off ratio and low electrical impedance under conditions of high concentration of TiOPc, small film thickness, high light intensity, and low frequency. To design this motor based on a one-frequency-two-mode driving method, an analytical solution is derived and an optopiezoelectric linear motor (OP-LM) is developed. Our analytical analysis, finite element simulation, and experimental results demonstrate that traveling waves can be generated by driving this motor at a frequency between the first and the second bending modes with a 90° phase difference between two designed actuating areas. The optimal condition is to match the driving frequency and light switching frequency. The moving direction and velocity of objects in different weight can be optically controlled by illuminating different areas of an optopiezoelectric motor with two 10 W power LEDs and masks. Discussions on the developed theory, simulation, and experimental studies of the OP-LM are provided in this paper.

Design and Research on a Biped Clamp and Pull Piezoelectric Linear Motor Based on Inchworm Principle

The piezoelectric linear motor based on piezoelectric ceramic stack has a potential in high-tech field’s application such as optical waveguide packaging. Mechanical properties of piezoelectric linear motors in the existing researches still need to be improved. So have designed double foot clamping type piezoelectric linear motor based on the principle of inchworm, and analyzed the working principle. The performance analysis of the driving mechanism shows that the relationship between the amplitude of driving mechanism and voltage values is positively proportional, and the influence of frequency on its amplitude is not big. The performance of the clamping mechanism was studied through experiments. First, verified the feasibility of the principle, tested the amplitude and found that the amplitude increases with the increase of the voltage, but due to the influence of clamping mechanism modal, amplitude tends to be zero as frequency increase to a certain extent. Second, amplitudes of the driving foot in two clamping mechanism were compared to ensure the consistency of amplitude of each driving foot, and the magnification of driving mechanism displacement was obtained by clamping mechanism in the practical work. Analyzed the rail vibration caused by driving foot and the prototype speed characteristics and load characteristic, and obtained speed characteristic curve are, in which, the speed of the motor increases with increasing voltage, but will not be able to continue to increase when the voltage reached to 60V, and the related curve between frequency and speed is similar to the frequency characteristic curve of the clamping mechanism, which is mainly due to the impact from the clamping mechanism modal. Obtained the maximum output of the motor power is 1.8 N through the load characteristic experiment.

Resonant-type piezoelectric inertial linear motor based on the optimization of a dual stage tuning fork transducer.

A dual stage tuning fork transducer (DSTFT) is designed as a stator for a resonant-type inertial linear motor. The first- and second-layer resonant frequencies of DSTFT are automatically adjusted with a ratio of 1:2 by using an ANSYS optimization design algorithm, and a resonant-type sawtooth-shaped mechanical waveform is generated by composing the two resonant vibrations of DSTFT. An inertial linear motor prototype is fabricated and tested. Experimental results confirmed the effectiveness of the designed transducer. The no-load maximum speed is 21.5 mm/s with a driving voltage of 67.2 Vp-p at a base frequency of 2831 Hz. The linear speed is 10.5 mm/s, and the drag load is 0.02 N at a preload force of 1 N and a driving voltage of 114 Vp-p for the base frequency. The movement direction could be reversed by changing the driving voltage phase.

Improved wavelet cerebellar model articulation controller for precision positioning of piezo-driven stage

This paper proposes an improved wavelet cerebellar model articulation control system (IWCMACS) to control precision positioning of the linear piezoelectric motor (LPM). The proposed system combines the improved wavelet cerebellar articulation model controller (IWCMAC) with the estimated bound compensator controller to obtain high-precision positioning for applications requring accuracy within micrometer or nanometer range. In this research, the momentum and propotional factors are added into learning algorithm to escape from local minima points and speed up convergence of the system. The Lyapunov-Like Lema theory is used to estimate error bound to guarantee the stable of the system. The experimental results for the piezo-priven stage conclude the effectiveness and applicability of the proposed control system for model-free nonlinear.

A novel contact model of piezoelectric traveling wave rotary ultrasonic motors with the finite volume method

The operating principle of the piezoelectric traveling wave rotary ultrasonic motor is based on two energy conversion processes: the generation of the stator traveling wave and the rectification of the stator movement through the stator-rotor contact mechanism. This paper presents a methodology to model in detail the stator-rotor contact interface of these motors. A contact algorithm that couples a model of the stator which is discretized with the finite volume method and an analytical model of the rotor is presented. The outputs of the proposed model are the normal and tangential force distribution produced at the stator-rotor contact interface, contact length, height and shape of the stator traveling wave and rotor speed. The torque-speed characteristic of the USR60 is calculated with the proposed model, and the results of the model are compared versus the real torque-speed of the motor. A good agreement between the proposed model results and the torque-speed characteristic of the USR60 was observed.

Design and performance evaluation of an exponentially weighted moving average–based adaptive control for piezo-driven motion platform

In this article, building a controlled system with velocity feedback in the inner loop for a platform driven by piezoelectric motors is investigated. Such a motion control system is subject to disturbance such as friction, preload, and temperature rise in operation. Especially, temperature rise is an essential problem of using piezoelectric motor, but very few research works address this topic in depth. Exponentially weighted moving average method has been widely used in process control to deal with systematic change and drift disturbance. It is attempted to map the exponentially weighted moving average method and the predictor corrector control with two exponentially weighted moving average formulas into a run-to-run model reference adaptive system for velocity control. Using a predictive friction model, a dead-zone compensator is built that can reduce the friction effect and provide an approximately linear relation of the input voltage and the output velocity for the subsequent exponentially weighted moving average or predictor corrector control control design. Comparison of the exponentially weighted moving average, predictor corrector control, and proportional–integral–derivative controllers is carried out in experiment with different speed patterns on a single-axis and a bi-axial platform. The results indicate that the proposed run-to-run-model reference adaptive system predictor corrector control is superior to the other methods.