scholarly journals A Theoretical Method for Designing Thin Wobble Motor Using an Electromagnetic Force and an Electropermanent Magnet for Application in Portable Electric Equipment

2021 ◽  
Vol 11 (2) ◽  
pp. 881
Author(s):  
Sang Yong Park ◽  
Buchun Song ◽  
Yoon Su Baek
Keyword(s):  
Control Method ◽  
Theoretical Method ◽  
Basic Structure ◽  
Parameter Analysis ◽  
Attractive Force ◽  
Prototype Model ◽  
Force Model ◽  
Rotating Shaft ◽  
Simple Method ◽  
Electric Equipment

The thin wobble motors that are required to hold rating shafts employ an electropermanent magnet. This turns the holding force on and off by applying a momentary electrical pulse. To design the magnet devices without the need for finite element analyses, a theoretical force model is necessary for predicting the attractive force. In this paper, first, a force model is derived by estimating the permeance around the air gap. A magnetic circuit is constructed, employing a relatively simple method to build the model in clouding leakage flux. Thus, the basic structure and driving principle are also presented. Next, an analytical force model is constructed on the basis of distribution parameter analysis between the stator and the rotating shaft. The design of the electromagnet core and the control method are presented. Finally, a prototype model of the motor that is 30 mm in diameter and 7 mm in thick is fabricated. The two models are verified by comparing the results of FEM with the results of the experiments. They can properly predict the attractive force, so the thin wobble motor with holding force can be applied in portable electric equipment.

Design and Evaluation of Electromagnetic Wobble Motor

2012 ◽  
Vol 24 (3) ◽  
pp. 480-486 ◽  
Author(s):  
Masaki Miyake ◽  
◽  
Koichi Suzumori ◽  
Kazuo Uzuka ◽  
Keyword(s):  
Control Method ◽  
Basic Structure ◽  
The Other ◽  
Motor Drive ◽  
Reduction Mechanism ◽  
Two Phase ◽  
Basic Model ◽  
Electric Equipment ◽  
And Control

The purpose of this work is to develop a thin, electromagnetic wobble motor with a large amount of torque, a motor thinner than conventional ones and able to be applied to portable electric equipment. We have developed a basic model of the motor 30 mm in diameter and 5 mm in thickness. In this paper, the basic structure and control method are first presented. Next, the design of the electromagnets and the three types of gear pairs, which have different pressure angles for the reduction mechanism, are presented. Finally, the motor drive experiments are performed using two types of drive: one is a two-phase drive, and the other is a four-phase drive. Three types of gear pairs are also shown. The motor works successfully, and its great potential to be mounted in thin, portable equipments is confirmed.

scholarly journals S-N Curve Characterisation for Composite Materials and Prediction of Remaining Fatigue Life Using Damage Function

2021 ◽  
Vol 5 (3) ◽  
pp. 76
Author(s):  
Ho Sung Kim ◽  
Saijie Huang
Keyword(s):  
Fatigue Life ◽  
Composite Materials ◽  
Loading Rate ◽  
Theoretical Method ◽  
Damage Function ◽  
Simple Method ◽  
Arbitrary Choice ◽  
Number Of Cycles ◽  
First Time ◽  
Remaining Fatigue Life

S-N curve characterisation and prediction of remaining fatigue life are studied using polyethylene terephthalate glycol-modified (PETG). A new simple method for finding a data point at the lowest number of cycles for the Kim and Zhang S-N curve model is proposed to avoid the arbitrary choice of loading rate for tensile testing. It was demonstrated that the arbitrary choice of loading rate may likely lead to an erroneous characterisation for the prediction of the remaining fatigue life. The previously proposed theoretical method for predicting the remaining fatigue life of composite materials involving the damage function was verified at a stress ratio of 0.4 for the first time. Both high to low and low to high loadings were conducted for predicting the remaining fatigue lives and a good agreement between predictions and experimental results was found. Fatigue damage consisting of cracks and whitening is described.

Design of Vehicle’s Controlling System Used a 4WS Control Method Based on BP Neural Network

2011 ◽  
Vol 201-203 ◽  
pp. 276-280
Author(s):  
Ya Peng Liu ◽  
Yan Tang ◽  
Jia Bin Bi
Keyword(s):  
Neural Network ◽  
Bp Neural Network ◽  
Control Method ◽  
Theoretical Method ◽  
Learning Ability ◽  
Controlling System ◽  
Nonlinear Dynamic Characteristics ◽  
Tokyo Institute ◽  
Institute Of Technology ◽  
Technology Institute

In this paper, a 4WS control method based on BP neural network was introduced. It used the BP neural network to simulate the map of vehicle and the nonlinear dynamic characteristics of the tire to avoid large errors that relying on mathematical simulation model of the problem. The 4WS measured data of Tokyo institute of Technology institute of Japan was used and used BP neural network method to identify the nonlinear characteristics of vehicle and tires. System controller’s design is not based on any theoretical method, but on the BP neural network’s self-learning ability. Experimental results show that this method has good controlling characteristics, and it can improve the vehicle’s active safety and manipulating stability effectively.

scholarly journals Walks on graphs as symmetric or asymmetric tools to encrypt data

2002 ◽  
Vol 20 (1) ◽  
pp. 34 ◽  
Author(s):  
V. A. Ustimenko ◽  
Y. M. Khmelevsky
Keyword(s):  
Real Life ◽  
Theoretical Method ◽  
General Idea ◽  
Simple Groups ◽  
Prototype Model ◽  
Encryption Scheme ◽  
Symmetric Encryption ◽  
Encrypt Data ◽  
Rank 2 ◽  
Groups Of Lie Type

New results on graph theoretical method of encryption will be presented. The general idea is to treat vertices of a graph as messages, and walks of a certain length as ecnryption tools. We will construct one-time pad algorithms with a certain resistance to attacks when the adversary knows plaintext and ciphertext. Special linguistic graphs of high girth whose vertices (messages) and walks (encoding tools) could be both naturally identified with vectors over the finite field, and with the so-called parallelotopic graphs, which turn out to be efficient tools for symmetric encryption. We will formulate criteria when parallelotopic graph (or the more general graph of tactical configuration) is a graph of absolutely optimal encryption scheme, producing asymptotic one-time pad algorithm. We will show how to convert one-time pads, which are related to geometries of rank 2 of simple groups of Lie type, to a real-life encryption scheme involving potentially infinite text and flexible passwords. We will discuss families of linguistic and parallelotopic graphs of increasing girth as the source for the generation of asymmetric cryptographic functions and related open key algorithms. We will construct new families of such graphs via group theoretical and geometrical technique. The software for symmetric and asymmetric ecnryption (prototype model of the package) is ready for demonstration.

Dynamic Modeling and Response Analysis of a Planar Rigid-Body Mechanism With Clearance

2019 ◽  
Vol 14 (5) ◽  
Author(s):  
Chen Xiulong ◽  
Jiang Shuai ◽  
Deng Yu ◽  
Wang Qing
Keyword(s):  
Rigid Body ◽  
Dynamic Model ◽  
Dynamic Modeling ◽  
Contact Force ◽  
Kinematic Model ◽  
Dynamic Responses ◽  
Response Analysis ◽  
Prototype Model ◽  
Force Model ◽  
Normal Contact

In order to understand dynamic responses of planar rigid-body mechanism with clearance, the dynamic model of the mechanism with revolute clearance is proposed and the dynamic analysis is realized. First, the kinematic model of the revolute clearance is built; the amount of penetration depth and relative velocity between the elements of the revolute clearance joint is obtained. Second, Lankarani-Nikravesh (L-N) and the novel nonlinear contact force model are both used to describe the normal contact force of the revolute clearance, and the tangential contact force of the revolute clearance is built by modified Coulomb friction model. Third, the dynamic model of a two degrees-of-freedom (2DOFs) nine bars rigid-body mechanism with a revolute clearance is built by the Lagrange equation. The fourth-order Runge–Kutta method has been utilized to solve the dynamic model. And the effects of different driving speeds of cranks, different clearance values, and different friction coefficients on dynamic response are analyzed. Finally, in order to prove the validity of numerical calculation result, the virtual prototype model of 2DOFs nine bars mechanism with clearance is modeled and its dynamic responses are analyzed by adams software. This research could supply theoretical basis for dynamic modeling, dynamic behaviors analysis, and clearance compensation control of planar rigid-body mechanism with clearance.

scholarly journals Multitarget Search of Swarm Robots in Unknown Complex Environments

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
You Zhou ◽  
Anhua Chen ◽  
Hongqiang Zhang ◽  
Xin Zhang ◽  
Shaowu Zhou
Keyword(s):  
Closed Loop ◽  
Control Method ◽  
Force Model ◽  
Complex Environments ◽  
Target Response ◽  
Complex Environment ◽  
Multiple Targets ◽  
Virtual Force ◽  
Swarm Robots ◽  
Division Model

When searching for multiple targets in an unknown complex environment, swarm robots should firstly form a number of subswarms autonomously through a task division model and then each subswarm searches for a target in parallel. Based on the probability response principle and multitarget division strategy, a closed-loop regulation strategy is proposed, which includes target type of member, target response intensity evaluation, and distance to the corresponding individuals. Besides, it is necessary to make robots avoid other robots and convex obstacles with various shapes in the unknown complex environment. By decomposing the multitarget search behavior of swarm robots, a simplified virtual-force model (SVF-Model) is developed for individual robots, and a control method is designed for swarm robots searching for multiple targets (SRSMT-SVF). The simulation results indicate that the proposed method keeps the robot with a good performance of collision avoidance, effectively reducing the collision conflicts among the robots, environment, and individuals.

Axial impact behaviors of stub concrete-filled square steel tubes

2019 ◽  
Vol 22 (11) ◽  
pp. 2490-2503 ◽  
Author(s):  
YT Zhang ◽  
B Shan ◽  
Y Xiao
Keyword(s):  
Finite Element ◽  
Failure Modes ◽  
Steel Tube ◽  
Experimental Results ◽  
Parameter Analysis ◽  
Steel Tubes ◽  
Simple Method ◽  
Concrete Filled Steel Tube ◽  
Drop Weight ◽  
The Impact

Existing research on the widely used concrete-filled steel tubes is mainly focused on static or cyclic loading, and the studies on effects of high strain rate are relatively rare. In this article, seven stub concrete-filled steel tubular columns with square section were tested under both static and impact loads, using a large-capacity drop-weight testing machine. The research parameters were variable height of the drop-weight and different load types. The experimental results show that the failure modes of the concrete-filled steel tube columns from the impact tests are similar with those under static load, characterized by the local buckling of the steel tube. The time history curves of impact force and steel strain were investigated. The results indicate that with increasing impact energy, the concrete-filled steel tube stub columns had a stronger impact-resistant behavior. The dynamic analysis software LS-DYNA was employed to simulate the impact behaviors of the concrete-filled steel tube specimens, and the finite element results were reasonable compared with the test results. The parameter analysis on the impact behavior of concrete-filled steel tube columns was performed using the finite element model as well. A simple method was proposed to calculate the impact strength of square concrete-filled steel tube columns and compared favorably with experimental results.

scholarly journals WAVE FORCES ON SQUARE CAISSONS

1976 ◽  
Vol 1 (15) ◽  
pp. 132 ◽  
Author(s):  
G.R. Mogridge ◽  
W.W. Jamieson
Keyword(s):  
Experimental Data ◽  
Theoretical Method ◽  
Wave Forces ◽  
Simple Method ◽  
Method Of Calculation ◽  
Wave Flume ◽  
Wide Range ◽  
Wave Heights ◽  
And Storage ◽  
Water Depths

The forces and overturning moments exerted by waves on large vertical square-section caissons have been measured in the laboratory. Each model caisson extended from the bottom of a wave flume through the water surface and was oriented either with one side perpendicular to the direction of wave propagation or turned through an angle of forty-five degrees to this position. For a given orientation, each model was tested for a range of wave heights (up to the point of breaking) for various wave periods and water depths. A digital computer was used for the acquisition, processing, plotting and storage of the experimental data. In addition to the experimental work, an approximate theoretical method is presented which allows the wave loadings on a square caisson to be estimated by means of a simple desk calculation. The experimental data shows that this simple method of calculation is reasonably accurate over a wide range of wave conditions and caisson sizes.

scholarly journals Adaptive Inverse Control Based on Kriging Algorithm and Lyapunov Theory of Crawler Electromechanical System

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Guanyu Zhang ◽  
Yitian Wang ◽  
Yiyao Fan ◽  
Chen Chen
Keyword(s):  
Electromechanical Coupling ◽  
Control Method ◽  
Coupling Model ◽  
Virtual Prototype ◽  
Lyapunov Theory ◽  
Electromechanical System ◽  
Prototype Model ◽  
Control Effect ◽  
Adaptive Inverse Control ◽  
Inverse Control

The electromechanical system of a crawler is a multi-input, multioutput strongly coupled nonlinear system. In this study, an adaptive inverse control method based on kriging algorithm and Lyapunov theory is proposed to improve control accuracy during adaptive driving. The electromechanical coupling model of the electromechanical system is established on the basis of the dynamic analysis of the crawler. In accordance with the kriging algorithm, the inverse model of the electromechanical system of the crawler is established by offline data. The adaptive travel control law of the crawler is obtained on the basis of Lyapunov theory. Combined with the kriging algorithm, the adaptive driving reverse control method is designed, and the online system is used to update and perfect the inverse system model in real time. Finally, the virtual prototype model of the crawler is established, and the control effect of the adaptive inverse control method is verified by theoretical analysis and virtual prototype simulation.

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