scholarly journals A Disc-Type High Speed Rotary Ultrasonic Motor with Internal Contact Teeth

2021 ◽  
Vol 11 (5) ◽  
pp. 2386
Author(s):  
Jianmin Qiu ◽  
Ying Yang ◽  
Xin Hong ◽  
Piotr Vasiljev ◽  
Dalius Mazeika ◽  
...  
Keyword(s):  
High Speed ◽  
Longitudinal Vibration ◽  
Optimization Method ◽  
Ultrasonic Motor ◽  
Operating Voltage ◽  
Driving Voltage ◽  
Internal Contact ◽  
Transmission Structure ◽  
Minimum Operating ◽  
High Output

This paper presents a disc-type ultrasonic piezoelectric motor, which is designed for micro flying vehicles. It provides a high output rotation speed under low operating voltage, compared with common piezoelectric devices, by employing a “contact teeth” wave transmission structure. The ultrasonic motor (USM) consists of a trimorph disc stator, with triple internal contact teeth, a shaft and two hemispheric hard-wearing rotors. The operating principle of the USM is based on the superposition of the in-plane B03 vibration mode of the trimorph disc, and the first longitudinal vibration of the contact teeth. An optimization method of the stator structure parameters was proposed and validated by numerical modeling. The diameter and thickness of the stator are 20 mm and 1 mm, respectively. A prototype with the weight of 2 g was made for this experimental test. The optimal frequency of the excitation signal and the preload force are 98.5 kHz and 0.5 N, respectively. The minimum operating voltage was tested under 7.5 V and reached the speed of 225 rpm, and the maximum unloaded rotational speed of the USM reached 5172 rpm when 30 V driving voltage was applied. The maximum lifting force generated by this USM was measured as 46.1 mN, which is 2.35 times bigger than its weight.

A type of dual-rotor hybrid ultrasonic motor based on vibration of four side panels

2016 ◽  
Vol 28 (14) ◽  
pp. 1916-1924 ◽  
Author(s):  
Lin Yang ◽  
Xingxing Zhu ◽  
Sisi Di
Keyword(s):  
Torsional Vibration ◽  
Vibration Mode ◽  
Longitudinal Vibration ◽  
Piezoelectric Ceramics ◽  
Ultrasonic Motor ◽  
Outer Diameter ◽  
Operating Voltage ◽  
Vibration Modes ◽  
Bending Vibration ◽  
Longitudinal Vibration Mode

Based on vibration of four side panels, a type of dual-rotor hybrid ultrasonic motor without using the torsional piezoelectric ceramics polarized along the circumferential direction is presented. The first longitudinal and the first bending vibration modes of the four side panels are used to indirectly excite the first longitudinal and the second torsional vibration modes of the stator cylinder. There are rectangle piezoelectric ceramics bonded on both sides of the four side panels, which are uniformly distributed along the circumference of the stator cylinder. One pair of panels on the opposite side is used to indirectly excite the first longitudinal vibration mode of the stator cylinder, and the other pair is used to indirectly excite the second torsional vibration mode. The simulation results, using finite element method software Workbench, reveal the operating principles, and the optimal structure is proposed. The appearance size of the prototype is 27.2 mm × 27.2 mm × 70 mm, while the outer diameter of the stator cylinder is 20 mm. The working frequency of the prototype measured in experiment is 44.7 KHz, which is consistent with the numerical results. According to the major mechanical measurement at 450 Vp−p operating voltage and 3.46 N preload, the stalling torque of the prototype is 8 mN·m and the no-load speed is 140 r/min. The experimental results indicate that the motor can operate in the first longitudinal and the second torsional coupled vibration modes transformed from the first longitudinal and the first bending vibration modes of four side panels.

High Speed Information Network Planning using Stochastic Optimization Method

2013 ◽  
Author(s):  
Ki-Sang Song ◽  
Arun K. Somani
Keyword(s):  
Stochastic Optimization ◽  
Network Design ◽  
Multimedia Information ◽  
High Speed ◽  
Minimum Cost ◽  
Optimization Method ◽  
Multimedia Communication ◽  
Network Design Problem ◽  
Information Network ◽  
Traffic Characteristics

From the 1994 CAIS Conference: The Information Industry in Transition McGill University, Montreal, Quebec. May 25 - 27, 1994.Broadband integrated services digital network (B-ISDN) based on the asynchronous transmission mode (ATM) is becoming reality to provide high speed, multi bit rate multimedia communications. Multimedia communication network has to support voice, video and data traffics that have different traffic characteristics, delay sensitive or loss sensitive features have to be accounted for designing high speed multimedia information networks. In this paper, we formulate the network design problem by considering the multimedia communication requirements. A high speed multimedia information network design alogrithm is developed using a stochastic optimization method to find good solutions which meet the Quality of Service (QoS) requirement of each traffic class with minimum cost.

Parameter study and optimization design of a hat oblique tunnel portal

2021 ◽  
pp. 095440972110140
Author(s):  
Zijian Guo ◽  
Tanghong Liu ◽  
Wenhui Li ◽  
Yutao Xia
Keyword(s):  
High Speed ◽  
Optimization Design ◽  
Pareto Front ◽  
Optimization Problem ◽  
Optimization Method ◽  
Design Parameters ◽  
Parameter Study ◽  
Buffer Structure ◽  
Tunnel Entrance ◽  
The Ideal

The present work focuses on the aerodynamic problems resulting from a high-speed train (HST) passing through a tunnel. Numerical simulations were employed to obtain the numerical results, and they were verified by a moving-model test. Two responses, [Formula: see text] (coefficient of the peak-to-peak pressure of a single fluctuation) and[Formula: see text] (pressure value of micro-pressure wave), were studied with regard to the three building parameters of the portal-hat buffer structure of the tunnel entrance and exit. The MOPSO (multi-objective particle swarm optimization) method was employed to solve the optimization problem in order to find the minimum [Formula: see text] and[Formula: see text]. Results showed that the effects of the three design parameters on [Formula: see text] were not monotonous, and the influences of[Formula: see text] (the oblique angle of the portal) and [Formula: see text] (the height of the hat structure) were more significant than that of[Formula: see text] (the angle between the vertical line of the portal and the hat). Monotonically decreasing responses were found in [Formula: see text] for [Formula: see text] and[Formula: see text]. The Pareto front of [Formula: see text] and[Formula: see text]was obtained. The ideal single-objective optimums for each response located at the ends of the Pareto front had values of 1.0560 for [Formula: see text] and 101.8 Pa for[Formula: see text].

scholarly journals The Design of a Charge Pump Circuit and System with Input Impedance Modulation for a Flexible-Type Thermoelectric Generator with High-Output Impedance

Electronics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1212
Author(s):  
Kazuma Koketsu ◽  
Toru Tanzawa
Keyword(s):  
Input Impedance ◽  
Thermoelectric Generator ◽  
Charge Pump ◽  
Operating Voltage ◽  
Output Impedance ◽  
Two Phase ◽  
Pump System ◽  
High Output Impedance ◽  
A Charge ◽  
High Output

This paper describes a charge pump system for a flexible thermoelectric generator (TEG). Even though the TEG has high-output impedance, the system controls the input voltage to keep it higher than the minimum operating voltage by modulating the input impedance of the charge pump using two-phase operation with low- and high-input impedance modes. The average input impedance can be matched with the output impedance of the TEG. How the system can be designed is also described in detail. A design demonstration was performed for the TEG with 400 Ω. The fabricated system was also measured with a flexible-type TEG based on carbon nanotubes. Even with an output impedance of 1.4 kΩ, the system converted thermal energy into electric power of 30 μW at 2.5 V to the following sensor ICs.

scholarly journals Investigation of Low-Sidelobe Beampattern Controlling Methods for Acoustic Transmitting Array of Underwater Vehicles

2017 ◽  
Vol 24 (s2) ◽  
pp. 103-110
Author(s):  
Zhengyao He ◽  
Qiang Shi ◽  
Shaoxuan Wu
Keyword(s):  
Boundary Element ◽  
Element Model ◽  
Optimization Method ◽  
Underwater Vehicles ◽  
Unmanned Vehicles ◽  
Driving Voltage ◽  
Sound Waves ◽  
Low Sidelobe ◽  
Acoustic Transducer ◽  
Weighting Vector

Abstract In underwater unmanned vehicles, complex acoustic transducer arrays are always used to transmitting sound waves to detect and position underwater targets. Two methods of obtaining low-sidelobe transmitting beampatterns for acoustic transmitting arrays of underwater vehicles are investigated. The first method is the boundary element model optimization method which used the boundary element theory together with the optimization method to calculate the driving voltage weighting vector of the array. The second method is the measured receiving array manifold vector optimization method which used the measured receiving array manifold vectors and optimization method to calculate the weighting vector. Both methods can take into account the baffle effect and mutual interactions among elements of complex acoustic arrays. Computer simulation together with experiments are carried out for typical complex arrays. The results agree well and show that the two methods are both able to obtain a lower sidelobe transmitting beampattern than the conventional beamforming method, and the source level for each transmitting beam is maximized in constraint of the maximum driving voltage of array elements being constant. The effect of the second method performs even better than that of the first method, which is more suitable for practical application. The methods are very useful for the improvement of detecting and positioning capability of underwater unmanned vehicles.

An Optimization Design Platform for Fir-Tree Root and Groove for Steam Turbine

2018 ◽  
Author(s):  
Deqi Yu ◽  
Xiaojun Zhang ◽  
Jiandao Yang ◽  
Kai Cheng ◽  
Weilin Shu ◽  
...  
Keyword(s):  
Stress Concentration ◽  
Steam Turbine ◽  
Gas Turbines ◽  
High Speed ◽  
Optimization Design ◽  
Turbine Blades ◽  
Local Stress ◽  
Optimization Method ◽  
Steam Turbines ◽  
Geometry Configuration

Fir-tree root and groove profiles are widely used in gas turbine and steam turbine. Normally, the fir-tree root and groove are characterized with straight line, arc or even elliptic fillet and splines, then the parameters of these features were defined as design variables to perform root profile optimization. In ultra-long blades of CCPP and nuclear steam turbines and high-speed blades of industrial steam turbine blades, both the root and groove strength are the key challenges during the design process. Especially, in industrial steam turbines, the geometry of blade is very small but the operation velocity is very high and the blade suffers stress concentration severely. In this paper, two methods for geometry configuration and relevant optimization programs are described. The first one is feature-based using straight lines and arcs to configure the fir-tree root and groove geometry and genetic algorithm for optimization. This method is quite fit for wholly new root and groove design. And the second local optimization method is based on B-splines to configure the geometry where the local stress concentration occurs and the relevant optimization algorithm is used for optimization. Also, several cases are studied as comparison by using the optimization design platform. It can be used not only in steam turbines but also in gas turbines.

Optimization of High Speed Milling Cutter Based on Critical Cutting Speed

2008 ◽  
Vol 392-394 ◽  
pp. 793-797
Author(s):  
Bin Jiang ◽  
Min Li Zheng ◽  
Fang Xu
Keyword(s):  
High Speed ◽  
Influencing Factor ◽  
Cutting Speed ◽  
Optimization Method ◽  
Face Milling ◽  
Cutting Performance ◽  
Feed Speed ◽  
Milling Cutter ◽  
High Speed Milling ◽  
Cutting Heat

Based on analyses of cutting heat and temperature in high speed milling, to construct a model of critical cutting speed for high speed milling cutter, find out influencing factor of critical cutting speed, and put forward optimization method of high speed milling cutter based on critical cutting speed. The results indicate that chip conducts a majority of cutting heat along with increase of cutting speed, feed speed and the rake of cutter. Cutting heat which workpiece conducts gradually diminishes when heat source accelerates. When cutting performance of cutter satisfies requirements of high speed milling, the proportion of cutting heat which workpiece conducts approaches its maximum as cutting speed comes to critical cutting speed. To optimize high speed face milling cutter for machining aluminum alloy according to critical cutting speed, the cutter takes on better cutting performance when cutting speed is 2040m/min~2350m/min.

scholarly journals Design, fabrication and experimental studies of compliant flexure diaphragm for micro pump

2018 ◽  
Vol 7 (2.21) ◽  
pp. 66 ◽  
Author(s):  
R Roopa ◽  
P Navin Karanth ◽  
S M. Kulkarni
Keyword(s):  
Polyvinylidene Fluoride ◽  
High Performance ◽  
Experimental Studies ◽  
Single Layer ◽  
Operating Voltage ◽  
Driving Voltage ◽  
Element Analysis ◽  
Central Deflection ◽  
Large Numbers ◽  
Micro Pump

This study reports the performance of piezo actuated compliant flexure diaphragm for micropump and MEMS application. To achieve the high performance of diaphragm at the low operating voltage compliant flexure diaphragm design is introduced. Very limited work has done on the diaphragms of micropump. Large numbers of mechanical micropumps have used plane diaphragms. The central deflection of diaphragm plays an important role in defining the micropump performance. The flow rate of mechanical type micropump strongly depends on the central deflection of diaphragm. In this paper compliant flexure diaphragms are designed for micropump to achieve higher deflection at lower operating voltage. Finite element analysis of compliant flexure diaphragm with single layer PVDF (Polyvinylidene fluoride) actuator is simulated in COMSOL. Compliant flexure diaphragms with a different number of flexures are analyzed. The central deflection of compliant flexure diaphragms is measured for driving voltages of 90V to 140V in 10 steps. The deflection of the compliant flexure diaphragm mainly depends on flexure width and length, the number of flexures in the diaphragm, PVDF thickness, diaphragm thickness and driving voltage. Use of compliant flexure diaphragm for micropump will reduce the mass and driving voltage of micropump. An attempt is made to compare the results of compliant flexure diaphragms with plane diaphragms. From the experimental results it is noticed that the compliant flexure diaphragm deflection is twice that of the plane diaphragm at same driving voltage. Deflection of three flexure and four flexure compliant diaphragms is 10.5µm and 11.5µm respectively at 140V.  

scholarly journals High-Speed Hybrid-Logic Full Adder Using High-Performance 10-T XOR–XNOR Cell

2021 ◽  
pp. 263-269
Author(s):  
Tejaswini M. L ◽  
Aishwarya H ◽  
Akhila M ◽  
B. G. Manasa
Keyword(s):  
High Speed ◽  
High Performance ◽  
Full Adder ◽  
Cmos Technology ◽  
Power Performance ◽  
High Speed Design ◽  
Power Delay Product ◽  
Full Swing ◽  
Output Swing ◽  
High Output

The main aim of our work is to achieve low power, high speed design goals. The proposed hybrid adder is designed to meet the requirements of high output swing and minimum power. Performance of hybrid FA in terms of delay, power, and driving capability is largely dependent on the performance of XOR-XNOR circuit. In hybrid FAs maximum power is consumed by XOR-XNOR circuit. In this paper 10T XOR-XNOR is proposed, which provide good driving capabilities and full swing output simultaneously without using any external inverter. The performance of the proposed circuit is measured by simulating it in cadence virtuoso environment using 90-nm CMOS technology. This circuit outperforms its counterparts showing power delay product is reduced than that of available XOR-XNOR modules. Four different full adder designs are proposed utilizing 10T XOR-XNOR, sum and carry modules. The proposed FAs provide improvement in terms of PDP than that of other architectures. To evaluate the performance of proposed full adder circuit, we embedded it in a 4-bit and 8-bit cascaded full adder. Among all FAs two of the proposed FAs provide the best performance for a higher number of bits.

Sign in / Sign up

Export Citation Format

Share Document