scholarly journals Efficiency Model for Traveling Wave-Type Ultrasonic Motors Based on Contact Variables and Preload

Actuators ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 158
Author(s):  
Haoyu Sun ◽  
Hao Yin ◽  
Jiang Liu ◽  
Xilong Zhang
Keyword(s):  
Present Model ◽  
Ultrasonic Motor ◽  
Operating Conditions ◽  
Contact Interface ◽  
The Real ◽  
Ultrasonic Motors ◽  
Proposed Model ◽  
On Line ◽  
The Relationship ◽  
Feedback Voltage

The contact interface variables are difficult to measure for an ultrasonic motor. When the ultrasonic motor works under different preloads, the error between the traditional efficiency model and the real output is quite large. In order to solve these two problems, we propose a novel efficiency model. It takes measured preload and the feedback voltage data as the input, which may offer better accuracy and on-line ability. Firstly, the effect of the preload on the drive characteristics is investigated, and the relationship between preload and the change in motor energy input is analyzed. Secondly, a contact model based on measured preload and feedback voltage is built, providing a more accurate description of the contact variables. Finally, an efficiency model was developed with a new composite stator structure. A preload test rig for a 60 mm ultrasonic motor is built and real operating conditions are measured. The results show that the correlation coefficient of the present model is 0.991, larger than 0.925 of the conventional model. The proposed model is more consistent with the real working conditions for the motor.

Effect of the Rotor/Stator Interface Condition Including Contact Type, Geometry, and Material on the Performance of Ultrasonic Motor

1994 ◽  
Vol 116 (4) ◽  
pp. 726-732 ◽  
Author(s):  
Takashi Maeno ◽  
David B. Bogy
Keyword(s):  
Motor Performance ◽  
Three Dimensional ◽  
Dynamic Contact ◽  
Ultrasonic Motor ◽  
Interface Condition ◽  
Contact Interface ◽  
Element Analysis ◽  
Contact Type ◽  
Ultrasonic Motors ◽  
Rotor Model

The purpose of this paper is to show the dynamic contact characteristics and the motor performance of several types of ultrasonic motors. First, we compare the performance of “intermittent” and “traveling” contact type ultrasonic motors by using the locally deforming rotor model. We show that the motor performances are the same when the shape of the stator’s amplitude, and the rotor’s interpenetration are the same. Then, we show that the performance of these two types of motors are different according to the effects of inertia and actual three dimensional displacement by using the FE (finite element) analysis. Finally, the effects of the teeth and a surface layer at the contact interface on the performance of the ultrasonic motor, including T-N (torque-speed) characteristics and friction loss, are analyzed.

Modelling, Analysis and Flight Testing of a Military Turbofan Engine Under Windmilling Conditions

2019 ◽  
Author(s):  
Budharaju Balaji ◽  
N. Om Prakash Raj ◽  
Mahesh P. Padwale ◽  
G. P. Ravishankar
Keyword(s):  
Present Model ◽  
Operating Conditions ◽  
Time Dependent ◽  
Flight Testing ◽  
Flight Tests ◽  
Turbofan Engine ◽  
Safety Critical ◽  
Proposed Model ◽  
Modelling Analysis ◽  
Flight Envelope

Abstract Flight testing of a military low bypass turbofan engine involves multitudes of tests to ensure the Engine - Aircraft compatibility across the flight envelope. One of the safety critical tests is to conduct In-Flight restart of the engine. Detailed planning and careful execution is mandated for a single engine aircraft. Accurate modelling of sub-idle performance characteristics of the engine during windmilling conditions enables better prediction of engine behavior during in-Flight shutdown and restart. Typically, Engine manufacturer provides a Performance Cycle Deck (PCD) to predict and assess the performance of the engine across the flight envelope for all throttle positions. However, the PCD does not include sub-idle behavior. The present work focusses on developing a torque based engine behavior model which enables prediction of time dependent fan and compressor characteristics during sub-idle operations. The proposed model is divided into two parts. The first part deals with deceleration characteristics during engine shut-off and spool down, and the second part deals with the acceleration characteristics during spooling up and engine restart. In-flight spool-down (a quick relight without windmilling) restart data obtained through flight tests was used to validate the present model. The model is intended to be used for future flight tests which include windmill restarts under various operating conditions. The model is expected to accurately predict the correlation between aircraft speed and engine windmilling rotor speeds for arriving at a windmill restart envelope for the aircraft.

scholarly journals Methodological safety management issues of socio-economic entities

2021 ◽  
Vol 291 ◽  
pp. 03013
Author(s):  
Evgeniy Bikmetov ◽  
Liliya Amirkhanova ◽  
Natalya Galimullina ◽  
Zarina Sizonenko ◽  
Oksana Ignatyeva
Keyword(s):  
Safety Management ◽  
Economic Effect ◽  
Operating Conditions ◽  
Economic Damage ◽  
Internal Factors ◽  
Economic Relations ◽  
Economic Entity ◽  
Proposed Model ◽  
The Relationship ◽  
Management Issues

The article examines the methodological safety management basics of economic entities on the example of enterprises and organizations exposed to risks in the modern complex operating conditions. Uncertainty, stochasticity of socio-economic relations give rise to challenges that pose a threat to economic entities. Risks are understood as losses from alternative investments and costs of overcoming the consequences of crisis situations. The expediency of using the proposed methodology due to the occurrence of losses from the expectation damages and the unpredictability of the influence of external and internal factors causing economic damage. The authors propose to use a model that characterizes the relationship between the losses of a socio-economic entity and the number of measures that need to be implemented to eliminate the damage. The article describes an algorithm that allows to assess the capabilities of an enterprise and achieve the stated purpose. This problem statement makes it possible to evaluate all the options for overcoming the crisis and choose the optimal one, which will improve the object performance efficiency. According to the authors, minimizing the threats, understanding the best measures to overcome the crisis and the calculation of total costs are the main factors in achieving the economic effect of the proposed model.

A novel approach for preload measurement and analysis of fixed position preload spindle

2018 ◽  
Vol 233 (10) ◽  
pp. 3619-3632
Author(s):  
Jiandong Li ◽  
Yongsheng Zhu ◽  
Ke Yan ◽  
Xiaoyun Yan ◽  
Jun Hong
Keyword(s):  
Coupling Effect ◽  
Operating Conditions ◽  
Effect Of Temperature ◽  
The Finite Element Method ◽  
Fixed Position ◽  
Novel Approach ◽  
On Line ◽  
Bearing Stiffness ◽  
Variation Mechanism ◽  
The Relationship

Spindle preload has a decisive influence on the performance of precision machine tool spindle and is usually defined as a constant parameter in most theoretical studies. In fact, the spindle preload changes with the operating conditions, such as temperature and speed of spindle. An in-depth understanding of preload variation mechanism becomes important for preload optimization and adjustment. Although some scholars have theoretically studied the relationship between operating conditions and preload, the results lack experimental verification since there is no effective way to measure the preload on-line. In this paper, a special pressure transducer for the preload continuous measurement of fixed position preload spindle was proposed, and the coupling effect of temperature and speed on the preload was experimentally tested and theoretically simulated based on the finite-element-method-based thermo-mechanical model considering the nonlinearity of bearing stiffness. The results show that the spindle speed contributes to the increase of the spindle preload, while the temperature causes a decrease of the preload. The preload variation is the trade-off effect of temperature and speed on it. The deformation of the spacer caused by temperature and speed is the most important factor leading to the change of the spindle preload.

scholarly journals On-Line Interpretation and Real-Time Diagnosis of Rocket’s Single Equipment

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Erbao Xu ◽  
Yan Li ◽  
Lining Peng ◽  
Yuxi Li ◽  
Mingshun Yang
Keyword(s):  
Real Time ◽  
Launch Vehicle ◽  
The Real ◽  
Abnormal State ◽  
Proposed Model ◽  
Single Vehicle ◽  
On Line ◽  
Edge Layer ◽  
Time Diagnosis ◽  
Sheer Number

The work state of a launch vehicle is generally interpreted automatically on software. However, the sheer number of target parameters makes it difficult to realize real-time interpretation, and abnormal interpretation result does not necessarily mean that the vehicle is in abnormal state. This paper introduces the edge computing to achieve on-line interpretation and real-time diagnosis of a single launch vehicle. Firstly, the parameters to be interpreted were subjected to thresholding, leaving only those with high interpretation value. Next, the interpretation server layer of the real-time diagnosis model was built based on the attribute and value reduction algorithm of variable precision rough set (VPRS). Moreover, the higher-grade criteria were written in criterion modeling language (CML) and used to interpret the various higher-grade interpretation data pushed by the edge layer in real time. On this basis, the outputs of the edge layer and interpretation server layer were integrated to achieve the real-time diagnosis of single vehicle faults. Finally, the proposed model was proved feasible through the application in a launch vehicle.

The Influence of Cognitive and Affective Reactions to Feedback on Subsequent Goals

2010 ◽  
Vol 15 (2) ◽  
pp. 121-131 ◽  
Author(s):  
Remus Ilies ◽  
Timothy A. Judge ◽  
David T. Wagner
Keyword(s):  
Performance Feedback ◽  
Business School ◽  
Structural Equation ◽  
Emotional Reactions ◽  
Equation Model ◽  
Proposed Model ◽  
And Performance ◽  
Dispositional Measure ◽  
The Relationship ◽  
Reactions To Feedback

This paper focuses on explaining how individuals set goals on multiple performance episodes, in the context of performance feedback comparing their performance on each episode with their respective goal. The proposed model was tested through a longitudinal study of 493 university students’ actual goals and performance on business school exams. Results of a structural equation model supported the proposed conceptual model in which self-efficacy and emotional reactions to feedback mediate the relationship between feedback and subsequent goals. In addition, as expected, participants’ standing on a dispositional measure of behavioral inhibition influenced the strength of their emotional reactions to negative feedback.

Joshua Kates, Essential History: Jacques Derrida and the Development of Deconstruction (Evanston, Illinois: Northwestern University Press, 2005), 352pp, $29.95 (USD), ISBN 10: 0810123274, ISBN-13: 978-0810123274

Derrida Today ◽  
2008 ◽  
Vol 1 (1) ◽  
pp. 131-133
Author(s):  
Gary Banham
Keyword(s):  
Jacques Derrida ◽  
The Real ◽  
Northwestern University ◽  
Relationship Of ◽  
The Relationship

This book promises a ‘radical reappraisal’ (Kates 2005, xv) of Derrida, concentrating particularly on the relationship of Derrida to philosophy, one of the most vexed questions in the reception of his work. The aim of the book is to provide the grounds for this reappraisal through a reinterpretation in particular of two of the major works Derrida published in 1967: Speech and Phenomena and Of Grammatology. However the study of the development of Derrida's work is the real achievement of the book as Kates discusses major works dating from the 1954 study of genesis in Husserl's phenomenology through to the essays on Levinas and Foucault in the early 1960's as part of his story of how Derrida arrived at the writing of the two major works from 1967.

A Modified Dugoff Tire Model for Combined-slip Forces

2010 ◽  
Vol 38 (3) ◽  
pp. 228-244 ◽  
Author(s):  
Nenggen Ding ◽  
Saied Taheri
Keyword(s):  
Vehicle Dynamics ◽  
Tire Model ◽  
Magic Formula ◽  
Model Based ◽  
Proposed Model ◽  
Road Friction ◽  
On Line ◽  
Double Lane Change ◽  
Tire Forces ◽  
Tire Models

Abstract Easy-to-use tire models for vehicle dynamics have been persistently studied for such applications as control design and model-based on-line estimation. This paper proposes a modified combined-slip tire model based on Dugoff tire. The proposed model takes emphasis on less time consumption for calculation and uses a minimum set of parameters to express tire forces. Modification of Dugoff tire model is made on two aspects: one is taking different tire/road friction coefficients for different magnitudes of slip and the other is employing the concept of friction ellipse. The proposed model is evaluated by comparison with the LuGre tire model. Although there are some discrepancies between the two models, the proposed combined-slip model is generally acceptable due to its simplicity and easiness to use. Extracting parameters from the coefficients of a Magic Formula tire model based on measured tire data, the proposed model is further evaluated by conducting a double lane change maneuver, and simulation results show that the trajectory using the proposed tire model is closer to that using the Magic Formula tire model than Dugoff tire model.

Application of an Element-free Galerkin Method to Water Wave Propagation Problems

2014 ◽  
Vol 60 (1-4) ◽  
pp. 87-105 ◽  
Author(s):  
Ryszard Staroszczyk
Keyword(s):  
Wave Propagation ◽  
Galerkin Method ◽  
Present Model ◽  
Free Surface Elevation ◽  
Element Free Galerkin Method ◽  
Plane Flow ◽  
Element Free Galerkin ◽  
Proposed Model ◽  
Sloping Bed ◽  
Element Free

Abstract The paper is concerned with the problem of gravitational wave propagation in water of variable depth. The problem is solved numerically by applying an element-free Galerkin method. First, the proposed model is validated by comparing its predictions with experimental data for the plane flow in water of uniform depth. Then, as illustrations, results of numerical simulations performed for plane gravity waves propagating through a region with a sloping bed are presented. These results show the evolution of the free-surface elevation, displaying progressive steepening of the wave over the sloping bed, followed by its attenuation in a region of uniform depth. In addition, some of the results of the present model are compared with those obtained earlier by using the conventional finite element method.

A pilot web former designed to study retention-formation relationships

2010 ◽  
Vol 25 (2) ◽  
pp. 185-194
Author(s):  
Anna Svedberg ◽  
Tom Lindström
Keyword(s):  
Pilot Scale ◽  
Operating Conditions ◽  
Montmorillonite Clay ◽  
Speed Ratio ◽  
Good Reproducibility ◽  
Total Solids ◽  
Retention Aids ◽  
Solids Content ◽  
Relationship Of ◽  
The Relationship

Abstract A pilot-scale fourdrinier former has been developed for the purpose of investigating the relationship between retention and paper formation (features, retention aids, dosage points, etc.). The main objective of this publication was to present the R-F (Retention and formation)-machine and demonstrate some of its fields of applications. For a fine paper stock (90% hardwood and 10% softwood) with addition of 25% filler (based on total solids content), the relationship between retention and formation was investigated for a microparticulate retention aid (cationic polyacrylamide together with anionic montmorillonite clay). The retention-formation relationship of the retention aid system was investigated after choosing standardized machine operating conditions (e.g. the jet-to-wire speed ratio). As expected, the formation was impaired when the retention was increased. Since good reproducibility was attained, the R-F (Retention and formation)-machine was found to be a useful tool for studying the relationship between retention and paper formation.

Sign in / Sign up

Export Citation Format

Share Document