A new strategy for hunting alarm and stability evaluation for railway vehicles based on nonlinear dynamics analysis

2019 ◽  
Vol 234 (1) ◽  
pp. 54-64
Author(s):  
Yuanchen Zeng ◽  
Weihua Zhang ◽  
Dongli Song
Keyword(s):  
Nonlinear Dynamics ◽  
High Speed ◽  
Health Management ◽  
Rapid Development ◽  
Railway Vehicles ◽  
Stability Performance ◽  
New Strategy ◽  
Time Domains ◽  
The Stability ◽  
Selection Of

Due to the rapid development of high-speed railways, there is an extensive need for the condition monitoring of the stability of vehicles. Considering the weakness of the current alarm standards, a new index is introduced for describing the periodicity of the state variable series in the nonlinear dynamics system, and a new guideline – based on the proportion distribution of the index – is proposed for detecting the hunting and for evaluating the stability performance in both the space and time domains. Then, the selection of algorithm parameters is conducted and the generalization ability is validated; a number of simulations and tests are applied to further verify its effectiveness. The advantages of this new method, such as an accurate alarm for hunting motions, evaluation of vehicle dynamics, robustness and feasibility of the real time application, are highlighted. This method can further contribute to the prognostic and health management of railway vehicles through early warning and condition assessment.

Dynamic Performance of High-Speed Electric Multiple Unit within Multi-Body System Simulation

2019 ◽  
Vol 12 (4) ◽  
pp. 339-349
Author(s):  
Junguo Wang ◽  
Daoping Gong ◽  
Rui Sun ◽  
Yongxiang Zhao
Keyword(s):  
High Speed ◽  
Rapid Development ◽  
Dynamic Performance ◽  
Body System ◽  
High Speed Railway ◽  
Evaluation Indexes ◽  
Actual Operation ◽  
Multiple Unit ◽  
The Stability ◽  
Multi Body

Background: With the rapid development of the high-speed railway, the dynamic performance such as running stability and safety of the high-speed train is increasingly important. This paper focuses on the dynamic performance of high-speed Electric Multiple Unit (EMU), especially the dynamic characteristics of the bogie frame and car body. Various patents have been discussed in this article. Objective: To develop the Multi-Body System (MBS) model of EMU, verify whether the dynamic performance meets the actual operation requirements, and provide some useful information for dynamics and structural design of the proposed EMU. Methods: According to the technical characteristics of a typical EMU, a MBS model is established via SIMPACK, and the measured data of China high-speed railway is taken as the excitation of track random irregularity. To test the dynamic performance of the EMU, including the stability and safety, some evaluation indexes such as wheel-axle lateral forces, wheel-axle lateral vertical forces, derailment coefficients and wheel unloading rates are also calculated and analyzed in detail. Results: The MBS model of EMU has better dynamic performance especially curving performance, and some evaluation indexes of the stability and safety have also reached China’s high-speed railway standards. Conclusion: The effectiveness of the proposed MBS model is verified, and the dynamic performance of the MBS model can meet the design requirements of high-speed EMU.

Avoiding Instability on the Milling of Parts with Thin Features

2006 ◽  
Vol 526 ◽  
pp. 37-42 ◽  
Author(s):  
Francisco Javier Campa ◽  
Luis Norberto López de Lacalle ◽  
S. Herranz ◽  
Aitzol Lamikiz ◽  
A. Rivero
Keyword(s):  
Dynamic Model ◽  
High Speed ◽  
Spindle Speed ◽  
Depth Of Cut ◽  
Test Device ◽  
High Speed Milling ◽  
Thin Walls ◽  
Chatter Vibrations ◽  
The Stability ◽  
Selection Of

In this paper, a 3D dynamic model for the prediction of the stability lobes of high speed milling is presented, considering the combined flexibility of both tool and workpiece. The main aim is to avoid chatter vibrations on the finish milling of aeronautical parts, which include thin walls and thin floors. In this way the use of complex fixtures is eliminated. Hence, an accurate selection of both axial depth of cut and spindle speed can be accomplished. The model has been validated by means of a test device that simulates the behaviour of a thin floor.

scholarly journals An Improved Prediction Model of IGBT Junction Temperature Based on Backpropagation Neural Network and Kalman Filter

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yu Dou
Keyword(s):  
Neural Network ◽  
Kalman Filter ◽  
Prediction Model ◽  
Bp Neural Network ◽  
High Speed ◽  
Rapid Development ◽  
Junction Temperature ◽  
Insulated Gate Bipolar Transistor ◽  
Network Estimation ◽  
The Stability

With the rapid development of emerging technologies such as electric vehicles and high-speed railways, the insulated gate bipolar transistor (IGBT) is becoming increasingly important as the core of the power electronic devices. Therefore, it is imperative to maintain the stability and reliability of IGBT under different circumstances. By predicting the junction temperature of IGBT, the operating condition and aging degree can be roughly evaluated. However, the current predicting approaches such as optical, physical, and electrical methods have various shortcomings. Hence, the backpropagation (BP) neural network can be applied to avoid the difficulties encountered by conventional approaches. In this article, an advanced prediction model is proposed to obtain accurate IGBT junction temperature. This method can be divided into three phases, BP neural network estimation, interpolation, and Kalman filter prediction. First, the validities of the BP neural network and Kalman filter are verified, respectively. Then, the performances of them are compared, and the superiority of the Kalman filter is proved. In the future, the application of neural networks or deep learning in power electronics will create more possibilities.

scholarly journals Independently Rotating Wheels with Induction Motors for High-Speed Trains

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
B. Liang ◽  
S. D. Iwnicki
Keyword(s):  
Induction Motor ◽  
High Speed ◽  
Dynamic Control ◽  
Feedback Mechanism ◽  
Wheel Wear ◽  
Field Orientation ◽  
Railway Vehicles ◽  
Stability Performance ◽  
Field Orientation Control ◽  
High Speed Trains

Railway vehicles with conventional wheelsets often experience problems of lateral instabilities or severe wear when running at high speed. The use of an independently rotating wheelset (IRW) can potentially eliminate the cause of wheelset hunting and reduce wheel wear as the mechanical feedback mechanism causing the problem is decoupled. This paper presents an investigation into the design of a novel induction motor configuration and controller for IRW in order to provide the stability required to satisfy the performance requirements for railway vehicles. A computer model of the mechanical and electrical parts of the system was developed. Simulation and experiments of the wheelsets with active driving motor control have demonstrated that a wheelset with independently driven wheels has a good stability performance over a traditional wheelset. Controllers with indirect field orientation control for dynamic control of an induction motor have shown to be suitable for this application in both its response and its controllability.

scholarly journals Antibody-like proteins that capture and neutralize SARS-CoV-2

2020 ◽  
Vol 6 (42) ◽  
pp. eabd3916 ◽  
Author(s):  
T. Kondo ◽  
Y. Iwatani ◽  
K. Matsuoka ◽  
T. Fujino ◽  
S. Umemoto ◽  
...  
Keyword(s):  
High Speed ◽  
In Vitro Selection ◽  
Nasal Swab ◽  
Inhibitory Concentration ◽  
Rapid Development ◽  
Spike Protein ◽  
Emerging Pathogens ◽  
High Affinity ◽  
Selection Of

To combat severe acute respiratory syndrome–related coronavirus 2 (SARS-CoV-2) and any unknown emerging pathogens in the future, the development of a rapid and effective method to generate high-affinity antibodies or antibody-like proteins is of critical importance. We here report high-speed in vitro selection of multiple high-affinity antibody-like proteins against various targets including the SARS-CoV-2 spike protein. The sequences of monobodies against the SARS-CoV-2 spike protein were successfully procured within only 4 days. Furthermore, the obtained monobody efficiently captured SARS-CoV-2 particles from the nasal swab samples of patients and exhibited a high neutralizing activity against SARS-CoV-2 infection (half-maximal inhibitory concentration, 0.5 nanomolar). High-speed in vitro selection of antibody-like proteins is a promising method for rapid development of a detection method for, and of a neutralizing protein against, a virus responsible for an ongoing, and possibly a future, pandemic.

scholarly journals Independently Rotating Wheels With Induction Motors for High Speed Trains

Volume 2 ◽  
2004 ◽  
Author(s):  
B. Liang ◽  
S. D. Iwnicki ◽  
F. J. Swift
Keyword(s):  
Motor Control ◽  
High Speed ◽  
Induction Motors ◽  
Dynamic Control ◽  
Field Orientation ◽  
Stability Performance ◽  
Performance Requirements ◽  
Field Orientation Control ◽  
High Speed Trains ◽  
The Stability

Railway vehicles with conventional sets often cause problems of hunting and severe wear. The use of an independently rotating wheel set (IRW) would eliminate the cause of wheel set hunting and wear since an IRW can decouple the wheels. This paper presents an investigation into the design of a suitable motor configuration and controller for IRW in order to provide the stability required to satisfy the performance requirements. A computer model of the mechanical and electrical parts of the system was developed. Simulation and experiments of the wheelsets with active driving motor control have demonstrated that a wheelset with independently driven wheels has a good stability performance over a traditional wheelset. Controllers with indirect field orientation control for dynamic control of a motor have shown to be suitable for this application in both its response and its controllability.

Update on High-Speed Milling Dynamics

1990 ◽  
Vol 112 (2) ◽  
pp. 142-149 ◽  
Author(s):  
S. Smith ◽  
J. Tlusty
Keyword(s):  
High Speed ◽  
Metal Removal ◽  
Removal Rate ◽  
Spindle Speed ◽  
Stability Lobe ◽  
Milling Operations ◽  
Force Signal ◽  
The Stability ◽  
Milling Dynamics ◽  
Selection Of

As spindle speeds and power have increased, the possibility of using the stability lobe phenomena to substantially increase the metal removal rate has become more attractive, and selection of optimum spindle speeds has become an important consideration. It is shown that, for many milling operations, it is desirable to set the tooth frequency equal to the natural frequency. At this spindle speed, the development of resonant forced vibration is actually inhibited by regeneration of waviness. An algorithm is presented for automatically selecting the optimum spindle speed based on the cutting force signal.

A new High Speed and Accurate FPGA-based Maximum Power Point Tracking Method for Photovoltaic Systems

2017 ◽  
Vol 8 (3) ◽  
pp. 1335
Author(s):  
Adnane Hassani ◽  
Mountassar Maamoun ◽  
Rezki Tadrist ◽  
Ali Nesba
Keyword(s):  
High Speed ◽  
Maximum Power ◽  
Photovoltaic Systems ◽  
Point Tracking ◽  
Stability Performance ◽  
Power Point Tracking ◽  
Perturb And Observe ◽  
Power Point ◽  
The Stability ◽  
Xilinx Fpga

We introduce in this paper a new FPGA-based Maximum Power Tracker for photovoltaic systems. The developed approach targets to modify the perturb and observe in view of reaching rapid tracking and achieving excellent accuracy, while keeping the stability performance and the reduced complexity. To perform this improvement, an automatic and smart two steps switcher is integrated, in addition inputs FIR filters are incorporated<strong>. </strong>Therefore, a high sampling frequency is attained, and consequently the tracking speed is improved. MATLAB simulations and the Xilinx FPGA implementation results show that the improved approach reaches a performance very close to the recently published MPPT methods, with lesser complexity.

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