Download or read book Dynamic Analysis and Experiment Verificationof a Traveling Wave Ultrasonic Motor written by and published by . This book was released on 2005 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Piezoelectric Actuators written by Hu Huang and published by BoD – Books on Demand. This book was released on 2021-12-08 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: Taking advantage of high resolution, rapid response, and compact structure, piezoelectric actuators are widely employed for achieving precision positioning in both scientific research and industrial application. With the development of science and technology, the requirements for precision positioning are increasing. Accordingly, great efforts have been made to improve the performances of piezoelectric actuators, and significant progress has been achieved. This book discusses some recent achievements and developments of piezoelectric actuators, in terms of piezoelectric material, driving principle, structural design, modeling, and control, as well as applications.
Download or read book The Dynamics of Combined Axial torsional Standing wave Ultrasonic Motors written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Piezoelectric ultrasonic motors have the potential to enable important applications such as endovasular surgical micro-robots due to their high torque and power density at the 0.1-1 mm diameter range. A type of ultrasonic motor that is suitable for miniaturization is the combined axial-torsional standing-wave (CATS) ultrasonic motor that generates the CATS stator motion via pretwisted beam vibration converters. The operation of the motor involves (1) the generation of an ellipse-like stator tip trajectory when the pretwisted-beam stator is excited to vibrate in a CATS motion by a piezoelectric transducer, and (2) the transfer of frictional torque when the rotor is pressed against the stator tip. To gain a better understanding of the CATS ultrasonic motor, centimeter-scale prototypes were fabricated and tested to determine the characteristics of the motor design. Theoretical models of the pretwisted beam stator and the torque transfer mechanism were also investigated to help us predict the effects of various design parameters. The axial and torsional resonance frequencies of the pretwisted-beam stator needs to be matched for an effcient generation of the CATS stator motion. To help designers select the right analysis method for the design process, we investigated the validity of common pretwisted beam theories that assume the warping function of a pretwisted beam is locally identical to that of a prismatic beam. Through a scaling analysis of the equations governing the warping function of pretwisted beams -- derived using semi-inverse method and Hamilton's principle -- we obtained a set of criteria for checking the validity of the assumption. These criteria allow us to determine at what geometries the use of prismatic warping function will result in poor predictions of the axial resonance frequency and that alternative modelling methods are needed. Existing models of CATS motors ignore the vertical displacement of the rotor, predicting periodic behaviours that are co.
Download or read book The Dynamics of Combined Axial torsional Standing wave Ultrasonic Motors written by Daniel Kuang-Chen Liu and published by . This book was released on 2009 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: Piezoelectric ultrasonic motors have the potential to enable important applications such as endovasular surgical micro-robots due to their high torque and power density at the 0.1-1 mm diameter range. A type of ultrasonic motor that is suitable for miniaturization is the combined axial-torsional standing-wave (CATS) ultrasonic motor that generates the CATS stator motionvia pretwisted beam vibration converters.The operation of the motor involves (1) the generation of an ellipse-like stator tip trajectory when the pretwisted-beam stator is excited to vibrate in a CATS motion by a piezoelectric transducer, and (2) the transfer of frictional torque when the rotor is pressed against the stator tip. To gain a better understanding of the CATS ultrasonic motor, centimeter-scale prototypes were fabricated and tested to determine the characteristics of the motor design. Theoretical models of the pretwisted beam stator and the torque transfer mechanism were also investigated to help us predict the effects of various design parameters.The axial and torsional resonance frequencies of the pretwisted-beam stator needs to be matched for an effcient generation of the CATS stator motion. To help designers select the right analysis method for the design process, we investigated the validity of common pretwisted beam theories that assume the warping function of a pretwisted beam is locally identical to that of a prismatic beam. Through a scaling analysis of the equations governing the warping function of pretwisted beams -- derived using semi-inverse method and Hamilton's principle -- we obtained a set of criteria for checking the validity of the assumption. These criteria allow us to determine at what geometries the use of prismatic warping function will result in poor predictions of the axial resonance frequency and that alternative modelling methods are needed.Existing models of CATS motors ignore the vertical displacement of the rotor, predicting periodic behaviours that are contrary to the apparently random oscillations observed in the motor's steady-state operation. Our incorporation of the rotor's vertical motion results in a bouncing-disk model that explains various behaviours of the motor prototype, including the oscillations in the transient speed-time curve, and the effect of preload on stall torque and steady-state speed. The nonlinear dynamical system formed by the bouncing disk model shows that different stator trajectories and interface properties can give rise to complex phenomena such as period doubling bifurcation, chaos, and extremely long period "chattering orbits". Knowledge of the location and basins of attraction for these orbits gives us detailed understanding of the motor's behaviour that will help designers improve the performance of CATS ultrasonic motor.
Download or read book Control of Travelling Wave Ultrasonic Motors written by Sheung-Wai Chung and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Control of Travelling-wave Ultrasonic Motors" by Sheung-wai, Chung, 鍾尚威, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled Control of Travelling-wave Ultrasonic Motors submitted by CHUNG, Sheung Wai for the degree of Doctor of Philosophy at the University of Hong Kong in April 2006 A traveling-wave ultrasonic motor (TUSM) converts electricity into mechanical motion using piezoelectric effect. Generally two AC sinusoidal voltages with finite phase difference are employed to produce a continuous, time-varying bending of the stator. Such bending forms a traveling-wave along the surface of the stator. Since the rotor is hard pressed to the stator by a pressure disc, it is driven into rotation. The TUSM features a high holding torque. It offers a high torque at low speed characteristics. Its response is fast and it is much more than the traditional DC servomotor. Since it utilizes piezoelectric effect, there is no electromagnetic interference. Although the TUSM is very suitable for many mechatronic applications, its speed exhibits nonlinear response to controllable inputs. Such peculiarity presents a significant challenge for servo control using the TUSM. Different approaches of modeling have been adopted. These include equivalent circuit analysis, analytic approaches and finite element analysis. Unfortunately, they are either too complex or computationally intensive for controller design and simulation. In consequence, various empirical controllers have been employed. The first objective of this project is to develop a practical model of TUSM for control purposes. It relates the controllable inputs to the output torque of the TUSM. The second objective is to utilize this model to develop various modes of torque control, thus demonstrating its effectiveness. Both passive compliance and active speed controls are developed. Passive compliance control includes both the self-locking torque control and the reacting torque control. Neurofuzzy control and a practical model-based control have been explored for active speed control. Hence, all the control strategies which are essential for a robot manipulator are available, allowing TUSM to be deployed to it. A digital signal processing (DSP) based control system has been developed for experimental purpose. It consists of a DSP microcontroller, a power electronic drive, a TUSM and an optical encoder. The microcontroller provides two trains of PWM signals with variable frequency and duty ratio to the drive. The frequency expands the controllable speed span and the duty ratio offers a partial linear relationship to the motor torque. Through resonance, the drive converts a dc voltage into two sinusoidal voltages with finite phase difference. They are required to drive the TUSM. The optical encoder provides speed feedback to the microcontroller. This DSP-based system can therefore readily be deployed for standalone embedded mechatronic system. Experiments have demonstrated the effectiveness of self-locking torque and reacting torque control. Superior performance in tracking and disturbance rejection is also observed in both neurofuzzy and practical model-based controls. An abstract of exactly 419 words Signed ________________ Chung Sheung Wai DOI: 10.5353/th_b3689003 Subjects: Ultrasonic motors Servomechanisms
Download or read book Traveling Wave Ultrasonic Motors Based on the Piezoelectric Shear Effect written by Martin Schönecker and published by . This book was released on 2009 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Efficiency of Ultrasonic Motor Using Traveling Wave written by M. Kurosawa and published by . This book was released on 1988 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Evaluation of the Traveling Wave Ultrasonic Motor for Force Feedback Applications written by Nishant Venkatesan and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Traveling Wave Ultrasonic Motor written by and published by . This book was released on 2004 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling of the Stator of Piezoelectric Traveling Wave Rotary Ultrasonic Motors written by Valentin Bolborici and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is concerned with the modeling of the stator of a piezoelectric traveling wave rotary ultrasonic motor. Existing models for piezoelectric traveling wave rotary ultrasonic motors are either too complicated to be used in motor control or do not reflect the real behavior of the motor and are of limited use in developing a controller for the motor. Finite Element methods have been used in the past to examine the properties of piezoelectric structures however, the Finite Volume Method has always been ruled out without justification. The main goal of this thesis is to provide a Finite Volume modeling approach for the stator of the piezoelectric traveling wave rotary ultrasonic motor taking into account the basic theoretical principles from piezoelectricity and structural mechanics. This model can in future be extended to develop a complete model of the motor in addition to other piezoelectric structures. The Finite Volume Method is shown to have the following specific advantages over the Finite Element Method especially for structures with simple geometries: 1. the Finite Volume Method respects the PDEs conservation law structure due to the fact that the fluxes are conserved between cells/domains/subregions, 2. the Finite Volume Method involves only surface integrals thus making it easier to implement a rotor-stator contact model as the contact mechanism occurs at the boundary of the stator, and 3. the Finite Volume Method yields a system of ODEs that more intuitively map onto circuit simulation software. The Finite Volume Method is initially used to model a simple piezoelectric plate. A corresponding circuit of the piezoelectric plate model, based on the Finite Volume Method, is generated. Two additional but more complex models are considered: one for a unimorph plate and one for the stator of an ultrasonic motor. The modeling results obtained with the Finite Volume Method are validated by comparing them with the results obtained with Finite Element simulations performed with COMSOL. Two test platforms designed to test and validate the Finite Volume and COMSOL results for the simple piezoelectric plates and piezoelectric traveling wave rotary ultrasonic motors are also presented in this thesis.
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 1042 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Systematic Design of a Disc typed Traveling Wave Ultrasonic Motor written by Lim Chee Kian and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technology for Large Space Systems written by and published by . This book was released on 1986 with total page 674 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1987 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 892 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Abstracts of Science and Technology in Japan written by and published by . This book was released on 1989 with total page 798 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government wide Index to Federal Research Development Reports written by and published by . This book was released on 1966-06 with total page 726 pages. Available in PDF, EPUB and Kindle. Book excerpt:
