scholarly journals Efficient Planning and Solving Algorithm of S -Shape Acceleration and Deceleration

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Zhijie Li ◽  
Ligang Cai ◽  
Zhifeng Liu
Keyword(s):  
Solution Process ◽  
Numerical Solution Method ◽  
Solution Equation ◽  
Speed Advantage ◽  
Acceleration And Deceleration ◽  
Efficient Planning ◽  
Curve Profile ◽  
Low Efficiency ◽  
Solution Efficiency ◽  
Poor Stability

S -shape acceleration and deceleration are the most widely used flexible acceleration and deceleration method in the current CNC system, but its velocity solution equation contains irrational terms, which create a more complicated solution process. When analyzing the solution process of the S -shape acceleration and deceleration directly, using a traditional numerical solution method, the phenomenon of “solving the interval jump” arises, which is the main reason for low efficiency and poor stability of the solution. According to the S -curve profile and solution, the concept of separating the curve profile recognition from the velocity solution was proposed, and a method of quickly identifying the interval of the solution location was introduced. Through the method mentioned above, the complete acceleration and deceleration curve parameters can be obtained through a one-time plan and a one-time solution, and the solution efficiency and stability are guaranteed; solving the Newton problem depends too much on the initial value of Newton velocity, which not only retains the speed advantage of the Newton method but also uses the downhill factor to ensure its convergence. Through the simulation comparison and analysis, the efficiency, stability, and universality of the method are verified.

A Generic Method to Generate AS-Curve Profile in Commercial Motion Controller

2017 ◽  
Author(s):  
Youdun Bai ◽  
Xin Chen ◽  
Zhijun Yang
Keyword(s):  
Motion Controller ◽  
Residual Vibration ◽  
Practical Applications ◽  
Analytic Polynomial ◽  
Acceleration And Deceleration ◽  
Special Knowledge ◽  
Curve Profile ◽  
S Curve ◽  
Motion Profile ◽  
Better Than

It is well believed that S-curve motion profiles are able to reduce residual vibration, and are widely applied in the motion control fields. Recently, a new asymmetric S-curve (AS-curve) motion profile, which is able to effectively adjust the acceleration and deceleration periods, is proposed to enhance the performance of S-curve motion profile, and proved to be better than the traditional symmetric S-curve in many cases. However, most commercial motion controllers do not support the AS-curve motion profiles inherently. Special knowledge or expensive advanced controlling systems, such as dSPACE system, are required to generate the AS-curve motion command, which limits the applications of the AS-curve motion profile in many practical applications. In this paper, a generic method based on the Position-Velocity-Time (PVT) mode move supported by most commercial motion controllers is proposed to generate exact AS-curve motion command in real machines. The analytic polynomial functions of AS-curve motion profile are also derived to simplify the further application, and the effectiveness of the proposed method is verified by numerical simulation.

Synthesis of red/black phosphorus-based composite nanosheets with Z-scheme heterostructure for high-performance cancer phototherapy

Nanoscale ◽  
2021 ◽  
Author(s):  
Yong Kang ◽  
Zhengjun Li ◽  
Fengying Lu ◽  
Zhiguo Su ◽  
Xiaoyuan Ji ◽  
...  
Keyword(s):  
High Performance ◽  
Research Field ◽  
Black Phosphorus ◽  
Two Dimensional ◽  
The Poor ◽  
Low Efficiency ◽  
Poor Stability

Two dimensional black phosphorus nanosheets (BP NS) have attracted plenty of attentions in the research field of cancer photonic therapy. However, the poor stability and relatively low efficiency in reactive...

scholarly journals Aggregation-induced emission polymers for high performance PLEDs with low efficiency roll-off

2020 ◽  
Vol 4 (4) ◽  
pp. 1206-1211 ◽  
Author(s):  
Jiabao Gu ◽  
Zeng Xu ◽  
Dongge Ma ◽  
Anjun Qin ◽  
Ben Zhong Tang
Keyword(s):  
High Performance ◽  
Solution Process ◽  
Aggregation Induced Emission ◽  
Low Efficiency

AIE polymers pTPE-DPA-Cz and pTPE-DPA-Flu are synthesized and used as emitting layers in doped and non-doped polymeric LEDs through a solution process, and show maximum EQE of 3.26% in the doped PLEDs and CE of 3.69 cd A−1 for the non-doped PLEDs and low efficiency roll-off.

The Multi-Body Dynamic Systems Cloud Computing and Simulation Based on Modelica

2012 ◽  
Vol 459 ◽  
pp. 454-457
Author(s):  
Yao Hui Li ◽  
Yong Qiang Dong ◽  
Yi Zhong Wu ◽  
Shu Ting Wang
Keyword(s):  
Cloud Computing ◽  
System Modeling ◽  
Solution Process ◽  
Basic Solution ◽  
Simulation And Optimization ◽  
Model Library ◽  
Simulation Based ◽  
Body Dynamics ◽  
Low Efficiency ◽  
Multi Body

It difficult to achieve consistency and sharing storage of model library and data resources, realize modeling and functional classification and improve low efficiency based on multi-body simulation and optimization. Cloud computing concept and method are introduced in order to solve these problems. In addition, a multi-body dynamics system modeling and simulation platform for the cloud computing is established and the basic solution process of the platform is explained, which can realize security sharing, optimization and reuse of model resources of system, computing resources and data resources. Finally, feasibility analysis is to be made.

Innovative electrotechnological systems to provide the temperature modes of technological pipelines

2019 ◽  
Vol 2 (1) ◽  
pp. 29-39 ◽  
Author(s):  
S. G. Konesev ◽  
P. A. Khlyupin
Keyword(s):  
Induction Heating ◽  
Thermal Exposure ◽  
Heating System ◽  
The Arctic ◽  
Process Conditions ◽  
Heating Systems ◽  
Fluid Properties ◽  
Low Efficiency ◽  
Extreme North ◽  
Induction Heating System

Introduction: the systems of thermal effects on thermo-dependent, viscous and highly viscous liquids under conditions of the Arctic and the Extreme North are considered. Low efficiency and danger of heating systems based on burned hydrocarbons, heated liquids and steam are shown. Electrothermal heating systems used to maintain thermo-dependent fluids in a fluid state are considered. The evaluation of the effectiveness of the application of the most common electrothermal system — heating cables (tapes). The most effective electrothermal system based on induction technologies has been determined. Materials and methods: considered methods of thermal exposure to maintain the fluid properties of thermo-dependent fluids at low extreme temperatures. Results: presents an induction heating system and options for its implementation in the Extreme North and the Arctic. Conclusions: induction heating system to minimize loss of product quality, improve the system performance under changing process conditions, eliminate fire product, to reduce the influence of the human factor.

Opportunities for accelerating labor productivity growth: The role of small and medium enterprises

2020 ◽  
pp. 98-114
Author(s):  
Evguenia V. Bessonova ◽  
Alexander G. Morozov ◽  
Natalia A. Turdyeva ◽  
Anna N. Tsvetkova
Keyword(s):  
Labor Productivity ◽  
Productivity Growth ◽  
Small And Medium Enterprises ◽  
Growth Potential ◽  
Business Climate ◽  
Labor Productivity Growth ◽  
Positive Effects ◽  
Low Efficiency ◽  
Medium Enterprises ◽  
Medium Firms

The paper considers necessary conditions for acceleration of labor productivity growth in Russia. Based on micro data, as well as aggregate data, the paper quantifies the contribution of small and medium firms to labor productivity growth. It shows that mere increase of the number of small and medium enterprises is not as important for positive effects of these programs, as qualitative improvements: development of favorable environment for growth, which is largely determined by business climate. Accelerating productivity growth involves redistribution of labor and capital from inefficient to efficient enterprises. In particular, it is necessary to create conditions, which allow a firm to grow after it enters the market instead of stagnating as a small firm with low efficiency. At the same time, it is necessary for ineffective firms, which exhausted their growth potential, to have an opportunity to exit the market easily leaving resources including labor to fast-growing companies.

ANALYSIS OF COMPETING VARIANTS OF AIR CONDITIONING SYSTEMS WITHOUT AIR EXTRACTION FROM ENGINES AT THE STAGE OF PASSENGER AIRCRAFT ONBOARD SYSTEMS CONCEPTUAL DESIGN

2019 ◽  
Vol 6 (3) ◽  
pp. 80-85
Author(s):  
Denis Igorevich Smagin ◽  
Konstantin Igorevich Starostin ◽  
Roman Sergeevich Savelyev ◽  
Anatoly Anatolyevich Satin ◽  
Anastasiya Romanovna Neveshkina ◽  
...  
Keyword(s):  
Conceptual Design ◽  
Air Conditioning ◽  
Research University ◽  
Cooling System ◽  
Fuel Efficiency ◽  
Air Cooling ◽  
Moscow Aviation Institute ◽  
Air Conditioning System ◽  
Low Efficiency ◽  
Air Conditioning Systems

One of the ways to achieve safety and comfort is to improve on-board air conditioning systems.The use of air cooling machine determines the air pressure high level at the point of selection from the aircraft engine compressor. Because of the aircraft operation in different modes and especially in the modes of small gas engines, deliberately high stages of selection have to be used for ensuring proper operation of the refrigeration machine in the modes of the aircraft small gas engines. Into force of this, most modes of aircraft operation have to throttle the pressure of the selected stage of selection, which, together with the low efficiency of the air cycle cooling system, makes the currently used air conditioning systems energy inefficient.A key feature of the architecture without air extraction from the main engines compressors is the use of electric drive compressors as a source of compressed air.A comparative analysis of competing variants of on-board air conditioning system without air extraction from engines for longrange aircraft projects was performed at the Moscow Aviation Institute (National Research University).The article deals with the main approaches to the decision-making process on the appearance of a promising aircraft on-board air conditioning system at the stage of its conceptual design and formulated the basic requirements for the structure of a complex criterion at different life cycle stages.The level of technical and technological risk, together with a larger installation weight, will require significant costs for development, testing, debugging and subsequent implementation, but at the same time on-board air conditioning system scheme without air extraction from the engines will achieve a significant increase in fuel efficiency at the level of the entire aircraft.

Experimental and Numerical Analysis of a Motorcycle Air Intake System Aerodynamics and Performance

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
M. A. Abd Halim ◽  
N. A. R. Nik Mohd ◽  
M. N. Mohd Nasir ◽  
M. N. Dahalan
Keyword(s):  
Combustion Process ◽  
Three Dimensional ◽  
Engine Performance ◽  
Internal Flow ◽  
Rapid Expansion ◽  
Navier Stokes ◽  
Turbulent Fluctuation ◽  
Ansys Fluent ◽  
Induction System ◽  
Acceleration And Deceleration

Induction system or also known as the breathing system is a sub-component of the internal combustion system that supplies clean air for the combustion process. A good design of the induction system would be able to supply the air with adequate pressure, temperature and density for the combustion process to optimizing the engine performance. The induction system has an internal flow problem with a geometry that has rapid expansion or diverging and converging sections that may lead to sudden acceleration and deceleration of flow, flow separation and cause excessive turbulent fluctuation in the system. The aerodynamic performance of these induction systems influences the pressure drop effect and thus the engine performance. Therefore, in this work, the aerodynamics of motorcycle induction systems is to be investigated for a range of Cubic Feet per Minute (CFM). A three-dimensional simulation of the flow inside a generic 4-stroke motorcycle airbox were done using Reynolds-Averaged Navier Stokes (RANS) Computational Fluid Dynamics (CFD) solver in ANSYS Fluent version 11. The simulation results are validated by an experimental study performed using a flow bench. The study shows that the difference of the validation is 1.54% in average at the total pressure outlet. A potential improvement to the system have been observed and can be done to suit motorsports applications.

Clinical and microbiological aspects of vaginal microbiota at pregnant with threat of late miscarriages during treatment with vaginal gestagens forms

2017 ◽  
pp. 68-73
Author(s):  
I.P. Polishchuk ◽  
Keyword(s):  
Pregnant Women ◽  
Therapeutic Effect ◽  
Local Treatment ◽  
Vaginal Microbiota ◽  
Control Group ◽  
Before And After ◽  
Low Efficiency ◽  
Late Miscarriage ◽  
Microbiological Aspects ◽  
Micronized Progesterone

The objective: was to examine the effectiveness of treatment of late miscarriage threat by micronized form of progesterone for 100 mg – 3 times a day in the form of gelatin pills and vaginal tablets with lactose. Patients and methods. Under our supervision there were 70 pregnant women with normocenosis of vagina (NCV) without extragenital pathology, which were not performed systemic or local treatment with antibacterial drugs in the last 4 weeks. Among them 25 pregnant women with TLSM treated by gelatin tablets of micronized progesterone (GTP) (group 1); 25 pregnant women with TLSM, treated by vaginal micronized progesterone tablets (VPT) (2nd group) and 20 healthy women with physiological pregnancy – PV (control group). The distribution of women in the group adhered to the principles of randomization. The age of examined women ranged from 19 to 32 years, most pregnant women were aged under 30 years (89.02%). General clinical examination was carried out according to the standard scheme according to the Order MH of Ukraine № 620. Results. During the research we have determined the colpocytologcal dynamics and state of vaginal microbiota in pregnant women with threatened late miscarriage with initial vaginal normocenosis before and after treatment whit vaginal forms of progesterone. Conclusion. The received results showed low efficiency of micronized progesterone gelatin dragee at threat of the late miscarriage that at small therapeutic effect has led to the development of vaginal dysbiosis in all surveyed. In contrast, the use of micronized progesterone vaginal tablets – the maximally rapid therapeutic effect without disturbance of vaginal normocenosis. Key words: the threat of a late miscarriage, vaginal micronized forms of progesterone.

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